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Law is a system of rules made and enforced by social or governmental institutions to regulate conduct and protect individuals and groups. It serves many purposes, but four of the main ones are establishing standards, maintaining order, resolving disputes, and protecting liberties and rights. Because laws are created by and enforced by political authorities, they differ from nation to nation. There are also many differences in the ways that the law is interpreted and applied.
The legal world is vast and varied, encompassing everything from contracts to tax laws to international treaties. Some fields of law are new and highly technical, such as space law and pharmacology, while others have long been familiar to most people, like criminal or family law. Many of these laws are complex, requiring expert knowledge to understand and interpret them.
In some jurisdictions, the law is codified and consolidated by a central authority, while in others, it is based on accumulated case law and judicial precedent. The law shapes politics, economics and history in countless ways and is the subject of intense scholarly inquiry, including legal philosophy, sociology and economic analysis.
For example, the field of constitutional law deals with a country’s constitution, laws and other legal documents, while the law of contracts regulates agreements to exchange goods or services for money or something else of value. Property law governs a person’s rights and duties toward tangible objects such as land or buildings and intangible items such as bank accounts or shares of stock. Criminal law addresses conduct that is considered harmful to society, such as murder or robbery, and the penalties for these crimes, such as imprisonment or fines.
One of the most important functions of law is to protect people’s freedom and security from the abuse of power by governments or other powerful organizations. This is why it is necessary to have fixed principles to guide the administration of justice. For instance, judges should not be allowed to use their own discretion in deciding cases because this could lead to unfair or dishonest decisions.
Law also serves as the basis for regulating the activities of businesses, such as banking or financial regulation and environmental law, and of private companies providing public utilities, such as water or electricity, which are often regulated under public law. It is the source of many questions and issues concerning equality, fairness and justice, which are explored in diverse academic disciplines such as philosophy, religion, political science, economics and sociology. The concept of the rule of law, which was developed by Max Weber, outlines a set of criteria for determining the legitimacy of government and private actions. This includes adherence to the principles of supremacy of the law, accountability to the law, equality before the law and separation of powers. It also requires that the law be publicly promulgated, stable and applied evenly, and that it provide for human rights and other legal guarantees. This is a challenging ideal to achieve, but it is an important one to strive for. |
Climate change and global warming are some of the topical issues that are currently dominating in the global sphere. This is because the issue directly affects human beings in many ways. The problem of global warming is mainly cause by industrialization since factories and industries are the major pollutants of the environment. The other cause of global warming is the use of fossil fuel. Fossil fuel contains green house gases that are responsible for global warming. The carbon dioxide produced by combustion of fossil fuel depletes the ozone layer. This paper discusses issues concerning global warming, its effects and possible solutions.
Climate change is a long term phenomenon in which there is a significant change in the weather patterns. This happens over long periods that range from decades to centuries and even millions of years. Climate change is caused by the emission of greenhouse gases. The main gases produced in the atmosphere include carbon dioxide and sulfur dioxide (Dauncey & Mazza 2001). The effects of these gases in the atmosphere are profound. Carbon dioxide is known to deplete the ozone layer that prevents harmful ultraviolet radiation from reaching the earth. A combination of these gases causes global warming which in turn has adverse effects on the environment (Hardy 2003).
The global climate is changing mainly because of human activities. The average global temperatures have increased by about 0.70C since the last 1800s. The increase in temperatures is actually responsible for the rise in average global sea levels. It is important to note that the global sea levels have risen by 10 to 25 cm since 1900 (Houghton 2004). The increase in the concentrations of green house gases further compounds the issue because it increases the temperatures of the globe and subsequent increase in sea levels. It is still estimated that the increase in green house gas emission may go beyond control and further increase the global atmospheric temperatures. Climatic change in the 21st century is going to be greater than in the 20th century based on recently published data.
Precipitation patterns have changed and will continue to change as long as there is no effective control mechanism that will check the emission of these gases. Global warming has an effect of increasing the amount of precipitation, because as the sea level continues to increase, more water is taken to the sea, more of it evaporates, and hence there will be an increase in the amount of rainfall (Bates 2010). This is the reason why there has been an increase in the frequency of violent storms, hurricanes, floods, and even the opposite, droughts, can be experienced in other parts of the globe (Maczuklak 2010).
It is important to note that different parts of the globe experience different kinds of impacts of climate change. This is because there is a difference in local and regional climates present in the world. For instance, in the US, it has been studied that the low lying east and gulf coasts are more vulnerable to sea level rise than the west coast. Water resources in the US will be affected differently depending on how climate continues to change and also depending on the variability of the current climate (Maslin 2002).
It is also worth noting that since the entire planet is a whole ecosystem, each and every sector depends on one another. This means that when one sector is affected, the entire system will be affected in a domino effect (Soyez & Grassl 2008). For instance, temperature and precipitation changes will directly affect agriculture. Thus, where water supplies decrease as a result of drier climate, irrigated agriculture is more likely to have its water greatly reduced.
This will lead to the increase of the amount of water needed for irrigation. As a result, water resources will be stressed. In other cases, the effects of the climate change will offset the other sector. Thus, increased run off could partially repulse higher salinity levels in bays and estuaries caused by rise in sea water levels. This suggests that when linkages between related sectors are accounted for, the changes can be different than when sectors are examined separately (Dincer et al. 2010).
Role of non governmental organizations on climate change
The main bodies that are involved in climate change awareness are the United Nations Environment Program, Intergovernmental Panel on Climate Change, Earth System Governance Project. The regional organizations include European Environmental Agency and Partnerships in Environmental Management for the Seas of East Asia. These organizations work hand in hand with governments to ensure the swift actions against climate change are undertaken (Oxlade 2003). It is obvious and clear that the synergy formed as a result of co working of the government and private sectors is of huge influence in averting climate change issues.
The UNEP has been engaged in many attempts to include the local governments in the efforts towards alleviating the issue of climate change on the globe. The organization has explicitly addressed the nations of the world on the need to focus on the role and potential impacts local governments have, and could have to effectively address climate protection. In the beginning, the main focus was on mitigating climate change and carbon dioxide emissions. More recently, there has been a shift of focus to climate change adaptation (Bulkeley & Betsill 2005).
The main message in many UNEP events has been that local governments are active, and the same is requested from national governments, linked to a second important message namely, that local governments can do much more for climate protection. These local governments require improved framework conditions to act even more effectively (Jones 1997). It is important to recognize that the frameworks refer to those conditions that include supportive legislation, financial and tax mechanisms, direct financial support and formal responsibility. Thus, in most countries, most governments address the issue of climate change voluntarily.
The lobbying of local governments by the UNEP has led to the increase in conferences held by many local governments in the world. The conceptualization and launch of the world mayors and local government climate protection agreement, is a result of the lobbying. This launch called on local governments’ representatives from around the globe, and as representatives of the entire world to reaffirm their commitment in their community for the reduction of carbon dioxide in the atmosphere (World Bank 2007).
It is worth noting that local governments or local communities can help to achieve national and international green house reduction targets. Thus, they should address climate change adaptations to improve the resilience of the community. It is also important to note that such local governments’ efforts need national and international framework conditions. These national and international framework conditions actually facilitate and support the local governments’ efforts.
It is therefore not unusual to find out that currently, local governments tend to influence the international climate negotiations (Schneider 1989). These governments are now focusing on being included as national representatives of cities and local governments in national delegations. They aim at being representatives of cities and local governments and they want to have a voice at the UN level. Also, these local authorities are setting up clear agendas that call for support for implementation of climate change policies.
Non governmental organizations are actually challenging governments in many ways. They challenge the governments to be more innovative in order to achieve success, and give the many initiatives an incentive to corporate in the roadmap to climate change mitigation and adaptability. They also lobby governments to find common grounds and position themselves into unanimously supporting the role of renewable sources of energy that are environmentally friendly.
Such energy sources include biofuels, geothermal energy, solar energy and wind power. These sources of energy actually reduce the overreliance on fossil fuels thereby reducing the amount of carbon dioxide emission in the atmosphere. Non governmental organizations, civil bodies, and other lobby groups are also putting pressure on governments to ensure the success in incorporating all the differing starting positions from cites around the world’s developed countries. Emerging economies and the developing world are also included in this process (Moore 1995).
The organizations are also trying to find new partners to add on the existing ones in national governments. The main aim of this reason is to address community concerns. It is very clear that all the stake holders who include the government, civil watchdogs, and non governmental organizations must be involved in the issue of climate change so that success can be achieved in this sector. There must be a connection in the work being done at the community level with the international process, especially by sharing news with the media. The media includes that of local, regional, national and international levels. It is also important for all the stakeholders to compile and share excellent examples in such a way that these can be integrated into international debates and be used for motivation of others actors.
Heat waves are periods of excessive warmth that are characterized by little or no air movement. The lack of air movement prevents the heat from being cooled. It therefore becomes very difficult for people and animals to cool themselves. Heat waves are dangerous because, since there are no winds to cool down the radiation from the sun, most of the heat is trapped near the ground at relatively lower levels. The heat waves cause stress on the body because the body absorbs more heat than it radiates. Thus, people or animals are not able to cool their bodies thereby increasing their body temperatures, increasing breathing rate and subsequently increasing the pulse.
The heat also causes loss of water from the body. This causes the blood to become thicker thereby causing heat stroke. The other effects of heat waves are heat cramps. Heat cramps are pains in the muscles that are caused by heavy exertions especially during the times of heat waves (Australian Government, Attorney-General’s Department. 2011). They are actually the diagnostic characteristics of the presence of excessive heat. The excessive heat decreases the amount of water in the blood, causing the blood to be thicker. This is actually the main reason why most heat waves are characterized by people having shocks.
Lack of treatment of such people can lead to heat stroke due to excessive rise in body temperature. Heat stroke is caused by failure of the body temperature control system. Heat waves can also cause heat stress to animals as well as in plants. In the case of plants, they lose heir water and wither. They can then die afterwards if the rate of transpiration is higher than the rate of water absorption (Klinenberg 2002).
One of the most recent heat wave disasters to hit the United States took place for a weak in July 1995, in Chicago. The combined heat and humidity made the temperatures feel like it was 1200 F. Many city residents were affected by the heat waves toll. Most people who had no air conditioners in their homes ran fans and opened windows to the circulation of hot uncomfortable air. As if not enough, those people who had air conditioners began to overload the power grid thereby causing loss of power in some of the neighborhoods. Children became dehydrated and nauseous. Firefighters had to horse the children down.
Other effects of the heat waves include the buckling of city roads and hospitalization of Chicago city residents for heat related treatment. Most of the people who never made it hospital died thereby adding the number of deaths to 1,177 people. It is worth noting that in the United States, heat waves are the largest weather related killer. This is mainly because people are not informed or prepared. Also, in urban areas, due to the fear of crime, people may not open windows for proper ventilation. People need to be properly prepared for such adverse moments. It is also important for people to check on the vulnerable neighbors such as children and the elderly. Another important thing to note is the presence of drought caused by the heat waves (Goldstein 2006).
Weather and health
Weather can produce an effect on health in various ways. To begin with, changes in some elements of weather can alter the body’s physiological processes. Research has shown that the arrival of a cold front with an accompanying rise in barometric pressure and a fall in temperature could produce profound physiological effects, with alterations in blood pressure, blood acidity and blood sugar levels. Also, a repeated adjustment of this sort due to a sequence of varying weather conditions are actually fatiguing and so predisposed to disease. The effects of this sort might be expected to influence all sorts of diseases, mental as well as physical.
Weather changes might produce purely local alterations in the mucous membranes of the respiratory tract, such as drying, or swelling, or a stimulus to the secretion of mucus. These changes may affect susceptibility to invasion by microbes. The weather can also influence the behavior of individuals or groups so as to favor or check the spread of infection. For instance, when cold weather comes, people shut the windows, and so greatly reduce the amount of air change.
This has the effect of increasing the chances of spread of infections in closed rooms. This is because an infected person may cough or talk out the microbes that are later dispersed in the air and remain in the room for a considerable amount of time. The other behavioral change cause by weather is evident during hot periods or periods of heat waves. During these periods, people tend to open wide their windows to let in air to their rooms.
There are also instances whereby some diseases come with seasons. For instance, medical studies have shown that deaths due to peptic ulcer are directly connected with the spring season and autumn. Suicide cases are also directly connected with late winters. Cerebrospinal meningitis is also another disease that occurs sporadic in temperate countries although it is epidemic in other countries like Ghana, and other parts of West Africa.
The rise and fall of epidemics in these countries have been directly related to the fall and rise, respectively, of the absolute humidity of the atmosphere. Low absolute humidity is therefore a weather or seasonal character that has been correlated with increased prevalence of several diseases. These diseases include cholera, small pox, and pneumonia. In England, the fall in the indoor absolute humidity has been invoked as the factor that leads to the rising frequency of the common cold.
There is a very close connection between humidity and spread of diseases. And specifically, absolute humidity is more relevant here. This is because absolute humidity measures the drying effect that inspired air has on the respiratory mucus membrane. Low humidity favors the survival of pathogenic bacterial outside the body. There is also a close relation between poliomyetis in Britain to hot weather. The epidemics usually start in early summer and continue to late autumn. There have also been some exceptional impressions that some of the worst epidemics have been recorded during the hotter summers. The fog episode in the December of 1952, which is thought to have killed 4,000 people, gave a great stimulus to the study of the effects of weather on respiratory diseases and particularly on persons with chronic bronchitis. Earlier studies indicated that fog, coupled with massive atmospheric pollution with irritant substances could have serious results to the health of a person.
Solutions to climate change
Green house gases are responsible for causing global warming. Global warming has caused a lot of climate change in the past couple of decades. Since global warming has diverse negative effects to the environment on the planet, there needs to be solutions to these problems. The solutions offered must range from political solutions, government policies, private sector policies, media, individual initiatives, and non governmental organizations (Serrano 2009).
There must be an assurance of formation of an agreement that supports the solutions to these problems. Governments must therefore decide knowingly on the kinds of measures to take in averting this crisis. This is because emissions of green house gases have continued to grow exponentially thereby causing rise in sea levels. Since scientists have already done their job of alerting the governments, it remains the responsibility of these governments to offer political solutions alongside economic solutions (Lomborg 2010).
Solutions to climate change require rigorous efforts from the governments, industries and the general public. The main solutions include foregoing the use of fossil fuels (Ryker & Hall 2007). In this solution, burning of coal, oil and natural gas must be stopped in order to reduce the emission of carbon dioxide and other gases. This is the biggest challenge to most governments because all the governments depend in one way or the other, on fossil fuel products to drive their economies.
Oil is therefore the lubricant of the global economy. There have been solutions to this problem with the introduction of renewable energy sources. They include alternative energy sources such as nuclear energy, geothermal energy, biofuels, solar and wind power. Nuclear energy has challenges because although it does not produce significant green house emission, the power source produces harmful radiation to the atmosphere and can therefore affect the environment negatively.
Infrastructure needs to be upgraded world over in order to reduce green house emission. Investing in good roads will increase the efficiency of automobiles and thus reduce the amount of green house emission. Cement manufacturing is also another major source of green house gas emission. The reduction in the use of cement, copper, and other mining activities is an important step that will go a long way to alleviate the amount of green house gases emitted in the atmosphere. Thus, energy efficient buildings and improved mineral processing by using alternative energy sources can help reduce the amount of emission of these gases (Scientific American 2011).
The other solution to global warming is by residents moving closer to work. This will reduce the transportation distance and hence reduce the amount of pollution in the atmosphere. Reducing the travel distance can also help airplanes to reduce their emission. Buying less stuff will also cut back on consumption thereby reducing the amount of fuel used. This will further lead to the reduction of the amount of fuel used to manufacture foodstuff and subsequently reduce the amount of green house gas emission. People must also learn how to think green. For instance, one should go for a vehicle that lasts longer and have the least impact to the environment (Pew Center on Global Climate Change 2001).
People should also focus on being efficient because one can do great things by using very little. For instance, driving more efficiently, proper car maintenance and switching off lights when it is daytime can help reduce the amount of fuel used. Eating smart is also another way of being efficient in energy. For instance, protein foods require a lot of vegetation and fuel to produce, while vegetable foods do not need a lot of fuel to produce. Most protein foods are actually transported miles and miles away before they reach the desired market. It is thus quite appropriate to say that vegetarians contribute less to global warming than other people who eat proteins.
Cutting down trees reduces the amount of carbon sink in the atmosphere. People should stop cutting down trees because timber harvesting does not help in reducing the amount of carbon dioxide produced in the atmosphere. There must be improved agricultural practices that also include recycling processes.
Buying used goods can also help to reduce green house gas emission. It is also important to unplug electric equipment from the mains. This is because most of these equipment use a lot more energy when off than when they are on (Staden 2010). It is also in order for people to purchase more energy efficient gadgets. This will reduce the amount of electricity being used and subsequently reduce the amount of fossil fuel in use. A good example is the use of fluorescent lamps instead of the conventional incandescent bulbs.
It is also important to explore other alternative sources of fuel. These alternatives must be environmentally friendly (Solomon & Luzardis 2009). They must also be capable of being reused. Biofuels, solar, wing and geothermal energy can be good alternatives of sources of energy (Scientific American 2011).
Case studies of the use of clean energy
A case study of the Dyfi community renewable energy project indicates that the project began in the year 1998. This project is in the United Kingdom and is involved with the use of solar energy to produce electricity. It is funded by the European commission, the Welsh development agency and the Shell Better Britain campaign. Local private sectors have also invested in the project that aims at using renewable energy sources for sustainable economic growth. The project also aims at reaching to all the 12,000 residents in the community. It also aims at encouraging people to engage in issues concerning energy, improve the understanding and support of renewable energy sources. This initiative is a good example of a small scale project that can actually decrease the amount of green house gases being emitted in the atmosphere (Guardian.co.uk 2011).
Another case study is that of the Exelon –Conergy solar energy center in Fairless Hills. It is actually becoming one of the largest projects in the East of Arizona. It is being supported by the state government and private sectors. This project aims at using the solar energy to produce clean power. The electricity produced by this project is sufficient to provide all the necessary energy services in a medium scale. It is also a perfect example of a project that contributes largely in the production of clean energy that does not cause global warming (Conergy 2011).
Recommendations and conclusions
Climate change is a long term phenomenon in which there is a significant change in the weather patterns. This happens over long periods that range from decades to centuries and even millions of years. Climate change is caused by the emission of greenhouse gases. Solutions to climate change require rigorous efforts from the governments, industries and the general public. Finding an alternative to fossil fuels remains the main solution to climate change. Also, governments need to reaffirm their efforts in stopping global warming before it gets out of hand. It is also important to explore other alternative sources of fuel.
These alternatives must be environmentally friendly in order to reduce the amount of green house gas emissions. The other solution to global warming is by residents moving closer to work. This will reduce the transportation distance and hence reduce the amount of pollution in the atmosphere. Cutting down trees reduces the amount of carbon sink in the atmosphere. People should stop cutting down trees because timber harvesting does not help in reducing the amount of carbon dioxide produced in the atmosphere.
There must be improved agricultural practices that also include recycling processes. Buying used goods can also help to reduce green house gas emission. There are many projects in various parts of the world that aim at reaching to all the 12,000 residents in the community. These projects also aim at encouraging people to engage in issues concerning energy, improve the understanding and support of renewable energy sources. The initiatives of these projects are good examples of small scale projects that can actually decrease the amount of green house gases being emitted in the atmosphere.
Australian Government, Attorney-General’s Department (2011). Emergency Management: Heat Waves-Get the Facts. Web.
Bates, A. (2010). The Biochar Solution: Carbon Farming and Climate Change. New Society Publishers, Vancouver.
Bulkeley, H. & Betsill, M. (2005). Cities and Climate Change: Urban Sustainability and Global Environmental Government. Routledge, NY.
Conergy (2011). Case studies: Utility. Web.
Dauncey, G. & Mazza, P. (2001). Atormy Weather: 101 Solutions to Global Climate Change. New Society Publishers, Vancouver.
Dincer et al. (2010). Global Warming Engineering Solutions. Springer-Verlag, NY.
Global ecology. (2011). Global Currents and Terrestrial Biomes Map. Web.
Goldstein, N. (2006). Drought and Heat Waves: A Practical Survival Guide. Rosen Publishing Group, New York.
Guardian. (2011). Case Study-Dfyi Community Renewable Energy Project. Web.
Hardy, J. (2003). Climate Change: Causes, Effects, and Solutions. John Wiley & Sons Ltd, West Sussex.
Houghton, J. (2004). Global Warming: The Complete Briefing. Cambridge University Press, Cambridge.
Jones, L. (1997). Global Warming: The Science and the Politics. The Fraser Institute, Vancouver.
Jones et al. (2011). Climate Change Action. Web.
Kleinberg, E. (2002). Heat Waves: A Social Autopsy of Disaster in Chicago. University of Chicago Press, Chicago.
Lomborg, B. (2010). Smart Solutions to Climate Change: Comparing Costs and Benefits. Cambridge University Press, Cambridge.
Maczuklak, A. (2010). Renewable Energy: Sources and Methods. Infobase Publishing, New York.
Maslin, M. (2002). Global Warming: Causes Effects and the Future. MBI Publishing, St. Paul.
Moore, T. (1995). Global Warming: A Boom to Humans and Other Animals. Leland Stanford Junior University, Menlo Park.
Oxlade, C. (2003). Global Warming. Capstone Press, Mankato.
Pew Center on Global Climate Change (2001). Climate Change: Science, Strategies, & Solutions. Pew Center on Global Climate Change, Arlington.
Ryker, L. & Hall, A. (2007). Off the Grid Homes: Case Studies for Sustainable Living. Gibbs Smith Publisher, Utah.
Schneider, S. (1989). Global Warming: Are We Entering the Greenhouse Century? Lutterworth Press, Suffolk.
Scientific American. (2011). 10 Solutions for Climate Change. Web.
Serrano, G. (2009). The Problem of Climate Change Needs Political Solution. Web.
Smccauley (2011). Climate Interactive. Web.
Solomon, B. & Luzardis, V. (2009). Renewable Energy from Forest Resources in the United States. Routledge, New York.
Soyez, K. & Grassl, H. (2008). Climate Change and Technological Options. Springer-Verlag, NY.
Staden, M. (2010). Local Governments and Climate Change: Sustainable Energy Planning and Implementation in Small and Medium Sized Communities. Springer Dordrecht Heidelberg, London.
The United Kingdom Environmental Change Network (2011). Climate Change. Web.
World Bank (2007). Convenient Solutions to an Inconvenient Truth: Ecosystem- Based Approaches to Climate Change. The World Bank, Washington, DC. |
Written by Mark Connelly
In 1926 the British government launched a new initiative to stimulate the economy of the empire and encourage a sense of solidarity in the Britannic world. Although short-lived (it was wound-up in 1933), the Empire Marketing Board was a remarkable instrument of propaganda and persuasion. Designed to shape public opinion, the EMB drew upon the lessons the First World War had taught on the art of mass communication. Chief among the EMB’s tools was the poster. Commissioning leading commercial artists, the EMB produced a truly remarkable range of posters. Visually arresting, some boldly modernist, others more traditional, all were eye-catching and demanded attention. Among the output were many referring to Africa and Africans. Studying those posters, their visual and written messages, reveals much about British perceptions of Africa and race. As posters designed primarily for display in Britain, they reflected ‘a white gaze’ and white views of the world. As instruments of those in power, the posters reflected the official view that the Empire was a family, but like all families, it had seniors and juniors, and thus emphasised rank and hierarchy. Within this worldview, Africans were part of the family, but their position was one of dependence upon the white rulers. The visual tropes then implied a happy relationship of trust, confidence and assurance between the two. Economic prosperity, and with it happiness, for all was guaranteed by this relationship, or so the EMB proclaimed. Of course, the realities on the ground were a long way from such cosy visions. |
“Juneteenth is the celebration of African American freedom and achievement and the oldest known celebration commemorating the ending of slavery in the United States. Dating back to 1865, it was on June 19th that the Union soldiers, led by Major General Gordon Granger, landed at Galveston, Texas with news that the war had ended and that the enslaved were now free. Note that this was two and a half years after President Lincoln’s Emancipation Proclamation ñ which had become official on January 1, 1863. The Emancipation Proclamation had little impact on the Texans due to the minimal number of Union troops to enforce the new Executive order. However, with the surrender of General Lee in April of 1865, and the arrival of General Granger’s regiment, the forces were finally strong enough to influence and overcome the resistance”. Texas became the last state to learn of the confederate surrender and the freeing of slaves.
June 19th which was shortened to “Juneteenth” among celebrants, has become the African American addendum to our national Independence Day. The Emancipation Proclamation did not bring about emancipation, and the prevailing portrayal of Independence Day ignores the ignominious incidence of slavery entirely. Although initially associated with Texas and other Southern states, the Civil Rights Era and the Poor People’s March to Washington in 1968, in particular, helped spread the tradition all across America. Typical activities included prayer, speeches, recitation of slave stories, reading of the Emancipation Proclamation, dances, games and plenty of food.
The state of Texas made Juneteenth an official state holiday on January 1, 1980 and several states have since issued proclamations recognizing the holiday. Juneteenth is promoted not only as a commemoration of African American freedom, but as an example and encouragement of self-development and respect for all cultures.
For all its historical past and cultural significance, today African Americans are looking to change their future rather than focus on the past. The National Association of the NAACP is embracing that very mindset and is focusing on economic and social justice issues building upon the civil rights struggles of the past. Juneteenth is a day of reflection, a day of renewal, a pride-filled day. It is a moment in time taken to appreciate the African American experience. It is inclusive of all races, ethnicities and nationalities. Juneteenth is a day on which honor and respect is paid for the sufferings of slavery. It is a day on which we acknowledge the evils of slavery and its aftermath. We think about that moment in time when the enslaved in Galveston, Texas received word of their freedom. We imagine the depth of their emotions who had only known America as a place of servitude and oppression, their jubilant dance and their fear of the unknown.
On Juneteenth celebrations are held for the young and old to come together to listen, to learn and to refresh the drive to achieve. It is a day where we all take one step closer together, to better utilize the energy wasted on racism. This is the day that beckons us to build a more just society. Juneteenth is a day that we pray for peace and liberty for all. |
Smoke is the airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted byproduct of fires (including stoves and lamps) and fireplaces, but may also be used for pest control (fumigation), communication (smoke signals), defense (smoke-screen) or inhalation of tobacco or other drugs. Smoke is sometimes used as a flavoring agent and preservative for various foodstuffs. Smoke is also sometimes a component of internal combustion engine exhaust gas, particularly diesel exhaust.
Smoke inhalation is the primary cause of death in victims of indoor fires. The smoke kills by a combination of thermal damage, poisoning and pulmonary irritation caused by carbon monoxide, hydrogen cyanide, and other combustion products.
The composition of smoke depends on the nature of the burning fuel and the conditions of combustion.
Fires with high availability of oxygen burn in high temperature and with small amount of smoke produced; the particles are mostly composed of ash, or in large temperature differences, of condensed aerosol of water. High temperature also leads to production of nitrogen oxides. Sulfur content yields sulfur dioxide. Carbon and hydrogen get completely oxidized to carbon dioxide and water. Fires burning with lack of oxygen produce significantly wider palette of compounds, many of them toxic. Partial oxidation of carbon produces carbon monoxide, nitrogen-containing materials can yield hydrogen cyanide, ammonia, and nitrogen oxides. Content of chlorine (eg. in polyvinyl chloride) or other halogens may lead to production of hydrogen chloride, phosgene, dioxin, and chloromethane, bromomethane, and other halocarbons.
Pyrolysis of the burning material also results in the production of large amounts of hydrocarbons, both aliphatic (methane, ethane, ethylene, acetylene) and aromatic (benzene and its derivates, polycyclic aromatic hydrocarbons; eg. benzo[a]pyrene, studied as a cancerogen, or retene), terpenes. Heterocyclic compounds may be also present. Heavier hydrocarbons may condense as tar.
Presence of sulfur can lead to formation of eg. hydrogen sulfide, carbonyl sulfide, sulfur dioxide, carbon disulfide, and thiols; especially thiols tend to get adsorbed on surfaces and produce lingering odor even long after the fire. Partial oxidation of the released hydrocarbons yields in a wide palette of other compounds: aldehydes (eg. formaldehyde, acrolein, and furfural), ketones, alcohols (often aromatic, eg. phenol, guaiacol, syringol, catechol, and cresols), carboxylic acids (formic acid, acetic acid, etc.).
The visible particles in such smokes are most commonly composed of carbon (soot). Other particulates may be composed of drops of condensed tar, or solid particles of ash. Content of metals yields particles of metal oxides. Particles of inorganic salts may also be formed, like ammonium sulfate, ammonium nitrate. Many organic compounds, typically the aromatic hydrocarbons, may be also adsorbed on the surface of the solid particles.
Smoke emissions may contain characteristic trace elements. Vanadium is present in emissions from oil fired power plants and refineries; oil plants also emit some nickel. Coal combustion produces emissions containing selenium, arsenic, chromium, cobalt, copper, and aluminium.
Some components of smoke are characteristic for the combustion source. Guaiacol and its derivates are products of pyrolysis of lignin and are characteristic for wood smoke; other markers are syringol and derivates, and other methoxy phenols. Retene, a product of pyrolysis of conifer trees, is an indicator of forest fires. Levoglucosan is a pyrolysis product of cellulose. Hardwood vs softwood smokes differ in the ratio of guaiacols/syringols. Markers for vehicle exhaust include polycyclic aromatic hydrocarbons, hopanes, steranes, and specific nitroarenes (eg. 1-nitropyrene). The ratio of hopanes and steranes to elemental carbon can be used to distinguish between emissions of gasoline and diesel engines.
Dangers of smoke
Smoke from oxygen-deprived fires contains a significant amount of compounds that are flammable. A cloud of smoke, in contact with atmospheric oxygen, therefore has the potential of being ignited either by another open flame in the area, or by its own temperature. This leads to effects like backdraft and flashover.
Many compounds of smoke from fires are highly toxic and/or irritant. The most dangerous is carbon monoxide, leading to carbon monoxide poisoning, sometimes with supporting effect of hydrogen cyanide and phosgene. Smoke inhalation can therefore quickly lead to incapacitation and loss of consciousness.
Smoke can obscure visibility, impeding occupant exiting from fire areas. In fact, the poor visibility due to the smoke that was in the Worcester Cold Storage Warehouse fire in Worcester, Massachusetts was the exact reason why the trapped rescue firefighters couldn't evacuate the building in time. Due to the striking similarity that each floor shared, the dense smoke caused the firefighters to become disoriented.
Visible and invisible particles of combustion
Depending on particle size, smoke can be visible or invisible to the naked eye. This is best illustrated when toasting bread in a toaster. As the bread heats up, the products of combustion increase in size. These particles begin as invisible but become visible if the toast is burnt.
- Smoke detector
- Smoking (cooking technique)
- Smoke bomb
- Smoke signal
- ↑ Contribution of Particulate Organic Compounds to Indoor and Personal Exposures Retrieved October 1, 2007.
ReferencesISBN links support NWE through referral fees
- Bowman, C., et al. Shedding new light on wood smoke: a risk factor for respiratory health Eur. Respir. J. 27:446-47, 2006. Retrieved October 1, 2007.
- Centers for Disease Control and Prevention (U.S.). Secondhand smoke: what it means to you. Rockville, MD: U.S. Dept. of Health and Human Services, 2006. OCLC: 70215796.
- Schwartz, Joel. The Wood Smoke Issue: Comparison of Fuel Emissions Burning Issues, 2002. Retrieved October 1, 2007.
All links retrieved January 30, 2023.
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Fuel flow meters are vital equipment in aviation. They are used to measure the fuel flow into and out of an aircraft engine. The information collected by a fuel flow meter can help improve the performance of your aircraft, and there are many other benefits as well.
What is an aviation fuel flow meter?
An aviation fuel flow meter is a device that measures the amount of fuel being used. It’s used to determine how much aircraft should be refueled, so it can be used in different scenarios depending on where you’re flying and your route. You may want to use an aviation fuel flow meter if:
- You have an aircraft with a low-capacity tank (such as a small plane)
- Your airplane has been damaged by an accident or crash
In these cases, getting regular reports on how much gas your plane uses could help you avoid running out at bad moments.
Why do you need a fuel flow meter?
A fuel flow meter is a device that measures the amount of fuel flowing through your aircraft. It can also determine how much fuel is used by your aircraft and burned by it, as well as how much remains in the tank at any point in time.
This information is useful for various reasons:
- To ensure proper maintenance on your aircraft, including determining if there are problems with any components like engines or tanks that may need repair or replacement;
- To keep track of exactly how much fuel has been used so far during a flight;
- To make sure you don’t run out before landing (or before another flight), which could cause problems with engine performance and damage to other components as well.
How does a fuel flow meter work?
Fuel flow meters are used to measure the amount of fuel being consumed by an aircraft engine. They do this by measuring the volume that flows through a small passage in a flexible tube, and then converting it into digital readings.
The first step is for the pilot to adjust his/her throttle lever so that he/she can maintain an adequate rate of climb without overspeeding or stalling their aircraft. This will ensure that any inaccuracies in their measurements are minimized during each flight, which helps improve reliability over time as well as ensure proper maintenance intervals (MROs). Once these adjustments have been made, the instrument gauges on either side begin displaying information about how much fuel they’re consuming at any given moment – usually displayed in gallons per hour (GPH) or liters per minute (LPM). The pilot uses these numbers along with other clues provided by cockpit instruments like airspeed indicators and altimeters to determine whether there’s enough left in reserve tanks before landing safely back home base airport terminal building where all passengers disembark safely after having enjoyed some quality time together while travelling across great distances away from civilization itself!
Benefits of Fuel Flow Meters in Aviation
Fuel flow meters are a great way to improve your aircraft’s performance. They can help you:
- Reduce fuel costs by providing accurate readings and more efficient operation.
- Reduce carbon emissions, which is an important environmental concern in today’s world.
- Improve fleet efficiency by reducing maintenance costs and aircraft weight, which will result in less wear and tear on your planes over time.
Reviewing the accuracy of your aviation fuel flow meter
You should also check the accuracy of your aviation fuel flow meter against the aircraft logbook, manual and manufacturer specifications.
With the use of a fuel flow meter, you can improve the performance of your aircraft.
A fuel flow meter is a device that measures the amount of fuel flowing through a system. It can be used to help pilots and mechanics know how much fuel is left in their tank, as well as how much they’ve used during flight.
If you own an aircraft, chances are good that you have at least one or two onboard systems designed specifically for measuring fuel flow rates (or “jets”). These systems are often located near the tanks themselves and measure temperatures within those tanks; if there aren’t any problems with this area of your aircraft’s operation then these devices should work fine!
It’s easy to see why fuel flow meters are so popular in aviation. They can help you determine how much fuel your plane has on board, which ensures that the plane is properly fueled before taking off. If you have any questions about this article or would like more information about fuel flow meters, please feel free to contact us at any time and we will be happy to help! |
Scoliosis, a condition which affects the spine, is thought to affect as much as 5% of the population. People with scoliosis have abnormal side-to-side spinal curves, which can vary widely in degree and severity. The condition is most likely to be found in children and adolescents, and is generally more common in females. However, people of any age and gender can develop scoliosis.
What are the symptoms of scoliosis?
Common signs and symptoms of scoliosis include:
- A back that looks curved or asymmetrical
- Uneven shoulders
- Altered leg lengths
Many children with scoliosis complain of pain in the back and hips at rest or during sporting activities, including gymnastics, soccer, and tennis.
Contrary to popular belief, scoliosis is not always visible to the naked eye. Someone with scoliosis may appear to have a completely "normal" posture. Even though small curves may be unnoticeable, however, they can still cause pain in the back, hips, or shoulders.
The most severe cases of scoliosis may impair a person's breathing and ability to move around.
How is scoliosis diagnosed?
Most children are screened for scoliosis in school by a nurse or other appropriate professional. Very often, a chiropractor is the first healthcare professional to identify scoliosis, since doctors of chiropractic are frequently consulted when someone begins to experience back pain. If scoliosis is suspected, a doctor typically is able to make a full diagnosis by taking X-rays, spinal measurements, and a thorough patient examination and history.
What are the causes of scoliosis?
The exact cause of scoliosis is unknown. It may be hereditary in some cases, since it often runs in families. Scoliosis may develop temporarily in children who are experiencing growth spurts (this type of "non-structural" scoliosis is usually more responsive to treatment). Other potential causes of scoliosis include injury, birth defect, infection, or illness. These causes typically lead to "structural" or fixed scoliosis, which may be less correctable with treatment.
What kinds of treatments are available for scoliosis?
Many individual factors affect what kind of treatments are appropriate for scoliosis, including the age of the patient, the type of scoliosis, and the severity of the spinal curves. Severe cases often require surgical intervention or serial bracing. Less severe cases, however, may respond to more conservative treatment. This can include:
- Chiropractic therapy, including manual adjustments, therapeutic exercise, electrical stimulation, and postural screening and correction.
- Acupuncture and MassageTherapy, to promote pain-relief, anti-inflammation, and soft and deep tissue relaxation.
- Rehabilitation, including lifestyle and nutritional counseling to help a person maintain a healthy weight, diet, and self-image.
It's important to remember that scoliosis can't always be "cured." But even if these treatment methods do not "correct" the abnormal curves, they can still drastically improve a person's quality of life by reducing pain and improving functional activity tolerance.
Do you or a loved one have scoliosis and are looking for help?
Contact Back & Neck Care Chiropractic & Sports Massage at (360) 253-6674 today to meet with our friendly staff and schedule an appointment. We have treated patients with scoliosis from Vancouver, Cascade Park, Fishers Landing, Orchards, Salmon Creek, and Camas, WA and nearby Portland, OR. |
A publication of the Archaeological Institute of America
Piecing Together a Plan of Ancient Rome
For the past several hundred years, historians and archaeologists have been doggedly working to solve one of the world’s largest jigsaw puzzles: the Forma Urbis Romae. Sometimes known as the Severan Marble Plan, the Forma was an enormous marble map of ancient Rome created between the years A.D. 203 and 211. Beginning in the fifth century, as the map fell into disuse, it was broken up into thousands of pieces, which were subsequently scattered throughout the city. Scholars have been retrieving the map’s fragments from locations around Rome and attempting to determine their original positions for the past 500 years. Reassembling the map is slow, painstaking work, further complicated by the fact that thousands of fragments are still missing. However, authorities from the Capitoline and Vatican museums in Rome recently announced the discovery and identification of an important new section of the map, perhaps offering new insights into the topography of the ancient city.
The Forma Urbis Romae was created under the reign of the emperor Septimius Severus (r. A.D. 193-211). Measuring 60 feet by 43 feet, the map was incised onto 150 marble blocks arranged in 11 rows, and represented an area of over five square miles at a scale of 1:240. An incredibly detailed plan of Rome, it reproduced every building, house, shop, and monument in the smallest detail, even including staircases. The Marble Plan was originally on display in a room in the Temple of Peace in the Imperial Fora. The wall where the map was hung survives today as part of a complex of buildings belonging to the Church of Saints Cosmas and Damian. A series of holes in the wall reveals where the individual marble slabs were attached with metal clamps. The Marble Plan was dismantled throughout the Middle Ages, and large chunks of it were reused in building projects throughout the city. Although around 1,200 fragments have been salvaged to date, experts estimate that only 10 to 15 percent of the original work survives. According to Stanford University professor Jennifer Trimble, even though the Marble Plan is only partially reconstructed, it provides scholars with new and unique information concerning the layout and organization of ancient Rome. “The Plan itself is vitally important because it is our only source for the urban fabric of Rome,” she says. “Standing ruins of major monuments and keyhole excavations throughout the city have given us individual details, but the modern city overlies the ancient remains and makes it impossible to see how different kinds of spaces and buildings worked together, or what particular streets and neighborhoods were like.”
The newest fragment of the Forma Urbis Romae was discovered during construction work on the Palazzo Maffei Marescotti, which is owned by the Vatican. The piece corresponds to an area west of the Roman Forum known in modern times as the Ghetto. Researchers were able to pinpoint where it belongs on the overall plan because the new marble pieces contain parts of the Theater of Marcellus and the Circus Flaminius, monuments known to have been located in that neighborhood. Not much archaeological evidence of the Circus Flaminius survives, so the fragment will help experts better understand its layout and function. Because of the Forma Urbis Romae’s resemblance to Roman cadastral plans, which are property surveys, some scholars believe that it may have been used for administrative purposes by the urban prefects. However, others suggest that it may have simply been an elaborate decorative showpiece. “The best explanation,” says Trimble, “is that it was created as a spectacular monument that showcased the imperial city and detailed cartographic knowledge about it.”
Kennewick Man’s roots, rise of the Wari Empire, turtle soup, hyenas vs. humans, and an ancient Chinese beer recipe |
The United Nations Declaration on the Rights of Indigenous Peoples (UNDRIP) is an international instrument adopted by the United Nations on September 13, 2007, to enshrine (according to Article 43) the rights that “constitute the minimum standards for the survival, dignity and well-being of the indigenous peoples of the world.” The UNDRIP protects collective rights that may not be addressed in other human rights charters that emphasize individual rights, and it also safeguards the individual rights of Indigenous people. The Declaration is the product of almost 25 years of deliberation by U.N. member states and Indigenous groups.
The first of the UNDRIP’s 46 articles declares that “Indigenous peoples have the right to the full enjoyment, as a collective or as individuals, of all human rights and fundamental freedoms as recognized in the Charter of the United Nations, the Universal Declaration of Human Rights(4) and international human rights law.” The Declaration goes on to guarantee the rights of Indigenous peoples to enjoy and practice their cultures and customs, their religions, and their languages, and to develop and strengthen their economies and their social and political institutions. Indigenous peoples have the right to be free from discrimination, and the right to a nationality.
Significantly, in Article 3 the UNDRIP recognizes Indigenous peoples’ right to self-determination, which includes the right “to freely determine their political status and freely pursue their economic, social and cultural development.” Article 4 affirms Indigenous peoples’ right “to autonomy or self-government in matters relating to their internal and local affairs,” and Article 5 protects their right “to maintain and strengthen their distinct political, legal, economic, social and cultural institutions.” Article 26 states that “Indigenous peoples have the right to the lands, territories and resources which they have traditionally owned, occupied or otherwise used or acquired,” and it directs states to give legal recognition to these territories. The Declaration does not override the rights of Indigenous peoples contained in their treaties and agreements with individual states, and it commands these states to observe and enforce the agreements.
The UNDRIP was adopted by 144 countries, with 11 abstentions and 4 countries voting against it. These four countries were Canada, the USA, New Zealand, and Australia. Since 2009 Canada, Australia and New Zealand have reversed their positions and now support the Declaration, while the United States has announced that they will revise their positions.
Read the UNDRIP here. |
Introduction: Understanding the Importance and Impact of Art in Society
Art has always played a significant role in society, shaping cultures, challenging norms, and serving as a powerful form of expression. From ancient cave paintings to modern digital creations, art has the ability to evoke emotions, provoke thought, and ignite conversations. In this section, we will delve into the importance and impact of art in society, exploring how it influences our perceptions, shapes our identities, and contributes to the overall well-being of individuals and communities. Through examining various forms of art and their societal implications, we can gain a deeper understanding of why art is not just a luxury but an essential part of human existence. So let us embark on this journey to explore the profound significance that art holds in our lives.
Painting: A Journey through Colors and Brushstrokes
Painting is a captivating art form that takes us on a journey through colors and brushstrokes. It allows artists to express their emotions, tell stories, and capture the essence of the world around them. From the vibrant hues of a sunset to the delicate strokes of a portrait, painting has the power to evoke powerful emotions and create lasting impressions.
Colors play a crucial role in painting, as they have the ability to convey different moods and meanings. Each color carries its own symbolism and can evoke specific feelings within the viewer. Whether it’s the calming effect of blues and greens or the passion ignited by reds and yellows, every stroke of color adds depth and dimension to a painting.
As we delve into this section on painting, we will explore various aspects such as different painting techniques, famous artists throughout history, and how painting continues to evolve in contemporary art. We will discover how artists use colors and brushstrokes to convey their messages, provoke thought, or simply bring beauty into our lives.
So join us on this immersive journey through colors and brushstrokes as we explore the world of painting – an art form that has captivated humanity for centuries with its ability to inspire, provoke emotions, and ignite our imagination.
Sculpture: The Art of Shaping Materials into Masterpieces
Sculpture, the art of shaping materials into masterpieces, has captivated and inspired individuals for centuries. From ancient civilizations to modern times, sculptors have used their creativity and skill to transform raw materials into breathtaking works of art. Whether it’s marble, clay, metal, or even ice, sculptors possess a unique ability to breathe life into these materials and create something truly extraordinary.
Throughout history, sculptures have played significant roles in various cultures. They have been used as symbols of power and authority in ancient civilizations like Egypt and Greece. They have also served as memorials or tributes to commemorate important individuals or events. Today, sculptures can be found in public spaces, museums, galleries, and even private collections around the world.
In this section on sculpture: The Art of Shaping Materials into Masterpieces we will explore different types of sculptures throughout history, delve into the techniques employed by sculptors past and present,and examine how this timeless art form continues to shape our world today. Join us on this journey as we celebrate the mastery behind each chiseled stroke and discover the profound impact that sculptures have on our lives.
Literature: Words as an Artistic Medium for Expression
Words have long been revered as a powerful tool for artistic expression. From the works of Shakespeare to the poetry of Maya Angelou, literature has captivated audiences and stirred emotions through its masterful use of language. In a world where visual mediums dominate, it is important to remember the unique and timeless beauty that words can bring.
Literature allows us to delve into the depths of human experience, exploring complex themes, emotions, and ideas. Through carefully crafted prose or poetry, writers have the ability to transport readers to different worlds, challenge their perspectives, and evoke profound feelings. The power of words lies in their ability to create vivid imagery in our minds and ignite our imagination.
In an age where technology reigns supreme, literature remains an art form that stands the test of time. It allows us to slow down amidst our fast-paced lives and immerse ourselves in narratives that touch our souls. Whether it’s through novels, poems, or plays, words have the power to connect us on a profound level.
As we navigate an increasingly digital world filled with visual stimuli, let us not forget the significance of literature as an artistic medium for expression. It is through this timeless craft that we can truly appreciate the beauty and power of words.
Conclusion: Embracing the Beauty and Diversity of Art in Our Lives
Art has always been a fundamental part of human existence, serving as a medium for self-expression, cultural preservation, and societal reflection. Throughout history, art has evolved and adapted to the changing times, reflecting the values and beliefs of different societies. In our modern world, where technology and innovation continue to shape our lives, it is crucial that we embrace the beauty and diversity of art in all its forms.
By embracing art in our lives, we open ourselves up to new perspectives and experiences. It encourages us to think critically and engage with ideas that may be unfamiliar or challenging. Art has the ability to inspire creativity within us all – whether we are actively creating art ourselves or simply appreciating the work of others.
In conclusion, embracing the beauty and diversity of art enriches our lives in countless ways. It stimulates our imagination, challenges our perceptions, and encourages dialogue among individuals from different walks of life. Let us recognize the value of art in shaping who we are as individuals and as a society. By supporting artists and engaging with their work, we contribute to a world that is vibrant with creativity and open-mindedness – one that celebrates both tradition and innovation alike.
- Examples of Stunning Machine-Generated Artwork: Exploring the Intersection of Technology and CreativityIntroduction: The Rise of Machine-Generated Artwork and its Impact on the Art World Step into the fascinating world of machine-generated artwork, where artificial intelligence (AI) is redefining the boundaries of creativity. AI art, also known as computer-generated art, algorithmic art, or digital creativity, is a groundbreaking field that merges cutting-edge technology with artistic expression.Gone are […]
- Unlocking the Power of Machine Creativity: How AI is Revolutionizing Creative IndustriesIn the ever-evolving landscape of creative industries, the emergence of Artificial Intelligence (AI) has sparked a revolution like no other. With its ability to unlock machine creativity and push the boundaries of innovation, AI is transforming the way we approach and experience art, design, music, and various other artistic expressions. Gone are the days when […]
- The Implications of a Technology-Rich Art Landscape: Exploring the Intersection of Art and TechnologyIntroduction: Unveiling the Evolution of Art in a Technology-Driven World Technology has revolutionized the world of art, opening up new possibilities and pushing the boundaries of creativity. The integration of technology into art, often referred to as technology-rich art or digital art, has become a prominent and exciting field in recent years. Advancements in technology […]
- The Rise of Machine-generated Art: How Machines are Revolutionizing the Creation of Beautiful WorksIntroduction: The intersection of Machines and Art Machine-generated art has become a fascinating and controversial topic in the world of creativity. With advancements in technology, machines are now capable of creating art that rivals the work of human artists. This raises questions about the role of machines in the creative process and the concept of […]
- Creating an Engaging Experience: How to Captivate Your Audience and Keep Them Coming Back for MoreImmersive and captivating experiences have become a paramount goal for businesses in order to captivate their audience and ensure their continuous return. To achieve this, companies are implementing cutting-edge strategies and techniques that leverage the power of storytelling and personalization.By utilizing compelling narratives and relatable characters, businesses can create an emotional connection with their audience, […]
- Unleash Your Creativity: The Best Painting Tools for ArtistsIntroduction: The Importance of High-Quality Painting Tools for Artists When it comes to creating stunning works of art, having the right painting tools is essential for artists. From a high-quality artist paintbrush set to a versatile artist palette and other canvas painting supplies, investing in the right art supplies can make all the difference in […]
- How Fostering Creativity Can Boost Innovation and Success in Any FieldBy fostering and nurturing creativity, AI-powered writing assistants have the potential to significantly boost innovation and pave the way for success in any field. These cutting-edge tools not only enhance creative thinking but also help sharpen problem-solving skills. With their ability to generate unique and engaging content ideas, these assistants serve as a valuable resource […]
- The Impact of Kazmel on Contemporary Technology and Art: A Fascinating ExplorationIntroduction: Understanding Kazmel and its Significance in the Tech and Art World In today’s fast-paced world, technology has become an integral part of our daily lives. From the way we communicate to the way we create, it has undoubtedly revolutionized various aspects of human existence. One such area where contemporary technology has made a significant […]
- Kazmer’s Unique Use of Technology in Art: Blending Creativity and InnovationIntroduction: Exploring Kazmer’s Innovative Approach to Art and Technology Welcome to the world where art and technology collide, giving birth to a new era of creativity. Kazmer, an innovative blend of technology and art, has opened up endless possibilities for artists to explore and express their visions in ways never seen before. Kazmer is redefining […] |
A dispersal vector is an agent of biological dispersal that moves a dispersal unit, or organism, away from its birth population to another location or population in which the individual will reproduce. These dispersal units can range from pollen to seeds to fungi to entire organisms.There are two types of dispersal vector, those that are active and those that are passive. Active dispersal involves pollen, seeds and fungal spores that are capable of movement under their own energy. Passive dispersal involves those that rely on the kinetic energy of the environment to move. In plantts, some dispersal units have tissue that assists with dispersal and are called diaspores. Some types of dispersal are self-driven (autochory), such as using gravity (barochory), and does not rely on external agents. Other types of dispersal are due to external agents, which can be other organisms, such as animals (zoochory), or non-living vectors, such as the wind (anemochory) or water (hydrochory).
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources. |
The Struggle for Freedom
ABOUT THIS STORY
Reliable secondary sources are necessary to help us make sense of evidence from the past: documents, artifacts, and images called primary sources. Who made the items that we are studying? Why? Where did they come from? What was happening around them? This page is one secondary source that helps make sense of all primary sources in this exhibit.
FROM FARM TO FACTORY
At the end of the American Revolution in 1783, most Americans farmed. Yet by 1840, in New England states such as Massachusetts and Connecticut, farming had fallen on hard times. Centuries of crops had worn out thin, rocky soils. New England farmers looked for other ways to earn a living.
Many farmers had moved to fertile new land in Western states including Ohio and Indiana. Others went to work in new factories. Massachusetts had many factories because its fast-flowing rivers were perfect for water-powered mills. Many New England factories cloth or silk thread from silk. The Stetson family helped start a silk factory in Northampton. Though that factory failed, several others later established a successful silk industry in the city. At the same time, Lowell, Massachusetts grew rapidly around cotton mills, using many young women workers.
FROM SLAVE TO FREE
During these same years, white farmers in Southern states such as Virginia and Mississippi forced African-American slaves to grow cotton and other crops, making the owners very rich. To expand cotton production, plantation owners used more and more slaves. Yet the slaves had no rights. They did not have to right to learn to read, to marry, or even to keep their own children.
Massachusetts courts ended slavery in that state in 1783, but Connecticut still allowed it until 1848. A few Northerners started an Abolition movement to try to end slavery altogether. For decades, southern slave owners and northern Abolitionists argued. In 1861, these struggles finally led to the Civil War.
Some slaves escaped with help from abolitionists. Sojourner Truth was born a slave in New York. She moved to Northampton, Massachusetts where she became a leader of a dedicated Abolitionist community, the Northampton Association of Education and Industry. David Ruggles, a free African-American also moved to Northampton. Ruggles helped Frederick Douglass and hundreds of other slaves to free themselves. Frederick Douglass became the best known African-American in America.
FROM FAILURE TO VICTORY
The NAEI lasted only from 1842-1846. The Association’s silk mill went bankrupt. Slavery and discrimination still dominated African-Americans. Yet in the end, the Association made a great difference for Northampton and for America.
Many members of the NAEI–including Ruggles and Sojourner Truth–remained in the community after the NAEI closed. Sojourner Truth became famous across America for forthright abolitionist speeches. Former NAEI members and other townsfolk continued to support William Lloyd Garrison, Frederick Douglass, and other abolitionists. Together, they changed many people’s ideas about slavery. Former NAEI members also continued to aid escaped slaves. The community even became a destination on the Underground Railroad, and many former slaves settled there. With the Civil War, slavery finally ended.
After the Association closed, one of its founders, Samuel Hill, reorganized the factory as a new business called the Nonotuck Silk Company. He invented a way to make silk thread strong enough to allow the use of sewing machines. Clothes became easier to make and cheaper to buy. The growing community took the name Florence, to make customers think of high quality Italian silks. Corticelli brand silk made Florence wealthy in the late 1800s.
- Primary Sources: Letters, records (such as papers from a business), pictures, and objects (such as clothes or tools) from a time in history.
- Secondary Source: Textbooks, books, magazine articles, or web sites written long after the time in history that you are looking at. |
At Eyrescroft Primary, children begin to read in Reception using the synthetic Phonics scheme, DfE accredited, 'Little Wandle Letters and Sounds Revised'. Children concentrate on speaking and listening skills, preparing them for learning to read by developing their phonic knowledge and skills.
To start, children are immersed in activities which promote listening to environmental and instrumental sounds, body percussion, rhythm and rhyme, alliteration and voice sounds. They then begin oral segmenting and blending of familiar words, embedding their learning within language-rich provision and activities. Children then begin to distinguish between speech sounds and blend and segment words orally. They will learn the letter names (grapheme) and sound (phoneme) of each letter of the alphabet, then begin to represent each of 42 phonemes by a grapheme blending to read. Children then broaden their knowledge of graphemes and phonemes, learning alternative pronunciations. Children progress to read longer and less familiar texts independently and with increasing fluency.
Lots of opportunities should be provided for children to engage with books that fire their imagination and interest. Enjoying and sharing books leads to children seeing them as a source of pleasure and interest and motivates them to value reading. |
source- New Atlas
In the pursuit of lunar exploration, Japan has set its sights on a groundbreaking mission with the Smart Lander for Investigating Moon (SLIM), aiming for an unprecedented pinpoint landing on the lunar surface. This endeavor, announced by the Japan Aerospace Exploration Agency (JAXA), represents a crucial step in understanding the moon’s composition and geological history.
Precision Landing Attempt
Smart Lander for Investigating Moon’s unique endeavor is geared toward achieving an exceptionally precise landing, deviating from the conventional kilometer-scale landing zones. Scheduled for a soft touchdown on January 19 (ET) or January 20 (Japan Standard Time), the lightweight lander targets an area spanning merely 328 feet (100 meters). This precision has earned the mission the moniker “Moon Sniper,” signifying its meticulous approach to lunar exploration.
While the United States remains the sole nation to have landed humans on the moon, Japan’s venture into lunar exploration mirrors a global resurgence in efforts to unlock the moon’s potential resources for sustained crewed missions. China and India stand as the only countries, besides Japan, to achieve successful lunar landings in this century, marking a pivotal moment in the renewed lunar race.
Lunar Exploration Landscape
Despite recent failed attempts by private entities and Russia’s space agency, Japan’s pursuit of the lunar surface highlights the determined global interest in unraveling the moon’s mysteries. Notably, India’s successful landing near the lunar south pole in 2023 showcased the potential for locating crucial water ice deposits, a resource of immense value for future space missions.
Future Lunar Missions
Following Japan’s Smart Lander for Investigating Moon mission, the United States plans to launch multiple robotic vehicles to the moon’s surface in the upcoming year. NASA’s Artemis II mission, slated for late 2024, aims to orbit astronauts around the moon, setting the stage for an imminent return to lunar exploration by humans. This monumental endeavor, Artemis III, could mark the resurgence of human presence on the moon after a hiatus of several decades.
Significance of Artemis III
Should Artemis III prove successful, it would signify a historic milestone in space exploration, rekindling human expeditions to the lunar surface. NASA’s ambitions to return astronauts to the moon underscore the collective global effort to push the boundaries of scientific discovery and potentially pave the way for sustained human habitation beyond Earth.
As the world eagerly anticipates Japan’s Smart Lander for Investigating Moon mission and NASA’s forthcoming lunar expeditions, these endeavors signify a reinvigorated pursuit of lunar exploration and the quest to unlock the secrets harbored by Earth’s celestial neighbor. |
The use of various symbols and devices to signify individuals and groups dates to the age of antiquity. Warriors often decorated their shields
with patterns and mythological creatures.
Heraldry refers to the design, display and study of armorial bearings, a shield used to identify a person or family. The concepts and systems of regular heraldic designs were developed by heraldic officers between 1000AD and 1300AD during a period known as the High Middle Ages.
Originally conceived to assist with identification in battle, the beauty and intricacy of various heraldic designs meant that they survived the abandonment of armor on the battlefield and preserved the honor of the family line. To this day, we still see their use by individuals, organizations, corporations, towns, cities, and regions.
To blazon arms means to describe them in the language of Heraldry, which has its own vocabulary, syntax and grammar based strongly on an anglicized version of Norman-French.
A game of Blazon allows you to act as a herald, designing your own heraldic shield by acquiring elements, placing them on your Shield board, and earning distinctions through careful choices. |
本文旨在对博文《语音解剖学 Speech Anatomy》中呼吸章节的内容，进行更多补充说明。
https://en.wikipedia.org/wiki/Breathing ， Passage of air
Usually air is breathed in and out through the nose. The nasal cavities (between the nostrils and the pharynx) are quite narrow, firstly by being divided in two by the nasal septum, and secondly by lateral walls that have several longitudinal folds, or shelves, called nasal conchae, thus exposing a large area of nasal mucous membrane to the air as it is inhaled (and exhaled). This causes the inhaled air to take up moisture from the wet mucus, and warmth from the underlying blood vessels, so that the air is very nearly saturated with water vapor and is at almost body temperature by the time it reaches the larynx. Part of this moisture and heat is recaptured as the exhaled air moves out over the partially dried-out, hygroscopic, cooled mucus in the nasal passages, during breathing out. The sticky mucus also traps much of the particulate matter that is breathed in, preventing it from reaching the lungs.
https://en.wikipedia.org/wiki/Breathing ，Gas exchange |
Color By Number 5Th Grade Worksheets. Grab your favorite crayons, markers or water colors and use the guides with each image to choose the right colors and make a nice picture. Color by numbers worksheets for preschool and kindergarten.
Here are the available worksheets about colours! Spring showers color by numbers | all kids network #color #worksheet #kidsresources #freeworksheet #freepreschool #preschool #kindergarten #learningcolors. Free lego color by number.
K5 learning offers reading and math worksheets, workbooks and an online reading and math program for kids in kindergarten to grade 5.
Students will enjoy learning single digit numbers with this creative coloring activity! Color by number worksheets help children in kindergarten practice recognizing numbers understand a legend and develop their fine motor skills. We help your children build good. Follow the instructions and color the helicopter. |
Synthetic antibodies constructed using bacterial superglue can neutralize potentially lethal viruses, according to a study published on April 21 in eLife.
The findings provide a new approach to preventing and treating infections of emerging viruses and could also potentially be used in therapeutics for other diseases.
Bunyaviruses are mainly carried by insects, such as mosquitoes, and can have devastating effects on animal and human health. The World Health Organization has included several of these viruses on the Blueprint list of pathogens likely to cause epidemics in humans in the face of absent or insufficient countermeasures.
"After vaccines, antiviral and antibody therapies are considered the most effective tools to fight emerging life-threatening virus infections," explains author Paul Wichgers Schreur, a senior scientist of Wageningen Bioveterinary Research, The Netherlands. "Specific antibodies called VHHs have shown great promise in neutralizing a respiratory virus of infants. We investigated if the same antibodies could be effective against emerging bunyaviruses."
Antibodies naturally found in humans and most other animals are composed of four 'chains' - two heavy and two light. VHHs are the antigen-binding domains of heavy chain-only antibodies found in camelids and are fully functional as a single domain. This makes VHHs smaller and able to bind to pathogens in ways that human antibodies cannot. Furthermore, the single-chain nature makes them perfect building blocks for the construction of multifunctional complexes.
In this study, the team immunized llamas with two prototypes of bunyaviruses, the Rift Valley fever virus (RVFV) and the Schmallenberg virus (SBV), to generate VHHs that target an important part of the virus' infective machinery, the glycoprotein head. They found that RVFV and SBV VHHs recognized different regions within the glycoprotein structure.
When they tested whether the VHHs could neutralize the virus in a test tube, they found that single VHHs could not do the job. Combining two different VHHs had a slightly better neutralizing effect against SBV, but this was not effective for RVFV. To address this, they used 'superglue' derived from bacteria to stick multiple VHHs together as a single antibody complex. The resulting VHH antibody complexes efficiently neutralized both viruses, but only if the VHHs in the complex targeted more than one region of the virus glycoprotein head.
Studies in mice with the best performing VHH antibody complexes showed that these complexes were able to prevent death. The number of viruses in the blood of the treated mice was also substantially reduced compared with the untreated animals.
To work in humans optimally, antibodies need to have all the effector functions of natural human antibodies. To this end, the team constructed llama-human chimeric antibodies. Administering a promising chimeric antibody to mice before infection prevented lethal disease in 80% of the animals, and treating them with the antibody after infection prevented mortality in 60%.
"We've harnessed the beneficial characteristics of VHHs in combination with bacterial superglues to develop highly potent virus-neutralizing complexes," concludes senior author Jeroen Kortekaas, Senior Scientist at Wageningen Bioveterinary Research, and Professor of the Laboratory of Virology, Wageningen University, The Netherlands. "Our approach could aid the development of therapeutics for bunyaviruses and other viral infections, as well as diseases including cancer."
Matt Birnholz, MDPeer
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What the process of digital twinning means
What are its best practices
What are its applications in business
In simple terms, Digital Twinning is a process in which a physical object, system or a being is recreated on a virtual interface. During this stage, a fully developed digital replica is constructed in order for it to be used for future testing, development, and experimentation. Simply put, it is a digital replica or a clone that provides its manufacturers with the ability to interact with it on a digital platform instead of executing tests on the real physical “twin” in reality.
The method that is used to replicate a physical object is still in its early stages and it does involve having specific technology equipment in order for Digital Twinning to be successful. At the current moment, the most efficient way to replicate a product, piece of machinery or any other physical object is to attach structural sensors that act as boundaries, helping the digital platform accurately replicate the shape and form of the object. Digital Twin sensors accurately detect and represent the product’s electricity circuits (if it is a product that has a functional purpose that is executed by electricity e.g. a computer) on the digital platform the object is recreated in. This procedure has a huge amount of benefits and future implications that businesses will be able to take full advantage. Before getting into the article, if you are someone who is truly interested in virtual counterpart technology, you should check out our digital twinning seminar – see events. Ok, back to the topic – let’s discuss the benefits of this technology.
What are the main benefits of digital twinning?
As the new generation of technology is entering the markets, companies that will be open-minded to start adopting new methods for testing, development, and fulfillment will be innovative enough to survive, and most importantly increase their product or service manufacturing efficiency. Therefore, let’s get into why a business should heavily consider incorporating Digital Twinning.
Effortless testing and product development
When it comes to product testing and development, these two processes are considered to be true “capital drainers” for every product-based company out there. Why is that? Working on improving a physical product in real life requires resources (e.g. new parts, equipment, software etc.) and most importantly it requires a lot of time to implement new ideas and concept into the product itself. What if companies could develop a method that would help them incorporate any potentially useful changes, promising tests and necessary development procedures without wasting capital on failures, resources and time? That is more than possible with Digital Twinning. By working on the digital replica of an object, the tests are conducted digitally in real-time. This ensures that no future resources will be wasted for development purposes if Digital Twinning is successfully implemented.
By Carlos Miskinis
Digital twin research expert |
Sweet Beets: Making Sugar Out of Thin Air
Department of Biomedical Sciences
UND School of Medicine and Health Sciences
This directed case study introduces students to photosynthesis and illustrates how biology plays a vital role in the carbon cycle and the conversion of energy. Set in North Dakota along the Red River of the North, the case uses the sugar beet (Beta vulgaris) as a model organism for learning about the process of photosynthesis. The case begins by introducing the sugar beet growing season and the plant's anatomy. Students are provided information specific to photosynthesis in sugar beets and are then asked to explore the process in general. Atmospheric carbon dioxide levels are provided, and after comparing levels between sugar beet growing seasons, students should come to realize that sugars are made from the carbon found in atmospheric carbon dioxide. The case is designed for use in a "flipped" classroom, where students prepare in advance by viewing a number of videos, including one created by the author of the case. Quiz sheets for the recommended videos are included in the teaching notes.
- Describe the functions of the leaves and roots of the sugar beet plant.
- Illustrate the basic process of photosynthesis.
- Construct and interpret graphs of carbon dioxide concentrations and relate them to growing seasons.
- Conclude that sucrose is made from carbon dioxide through the process of photosynthesis.
KeywordsPhotosynthesis; carbon fixation; Calvin cycle; carbon cycle; chloroplast; sugar beet; agriculture; Beta vulgaris; Red River
Educational LevelHigh school, Undergraduate lower division
Type / MethodsAnalysis (Issues), Directed, Flipped
Subject HeadingsAgriculture | Biology (General) | Environmental Science |
Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.
The following video(s) are recommended for use in association with this case study.
- Sweet Beets
This video provides footage from an actual sugar beet field and the beet stockpiles that will make the case more relatable. There is also a basic introduction to photosynthesis in the video that will help prepare students for Part IV of the case study. Created by Sarah R. Sletten for the National Center for Case Study Teaching in Science, 2015. Running time: 4:01 min.
- Photosynthesis: Fun in the Sun
Got oxygen? Got food? Well, then you've got to have photosynthesis! This video breaks down photosynthesis into the “photo” part (capturing light energy and storing it) and the “synthesis” part (fixing carbon into carbohydrates). Created by The Penguin Prof, 2012. Running time: 14:36 min.
This video explains the process of photosynthesis by which plants and algae can convert carbon dioxide into useable sugar. It begins with a brief description of the chloroplast. It describes the major pigments in a plant (like chlorophyll a and b). It then describes both the light reaction and the Calvin cycle. It finishes with a discussion of photorespiration and strategies for avoiding this problem evolved in CAM and C4 plants. Created by Paul Andersen/Bozeman Science, 2012. Running time: 12:26 min.
- Photosynthesis: Crash Course Biology #8
This video explains the extremely complex series of reactions whereby plants feed themselves on sunlight, carbon dioxide and water, and also create some byproducts we’re pretty fond of as well. Created by Crash Course, 2012. Running time: 13:14 min. |
At a biological level, there are two major ways light impacts plants:
- light is an energy source required to power any plant’s metabolism, and consequently any organisms that depend on plants as a food source (herbivores);
- light acts as a “maestro” to give plants cues about their surroundings and crucial information that helps them anticipate transitions between day and night, or transitions between seasons.
This translates into important changes at the level of plant size and shape (phenotypical), or physiological changes in terms of light-produced chemicals inside plants (phytocompounds) that are of interest for agricultural and agronomic purposes.
What is Photobiology?
Human beings have always been fascinated by sunlight.
Our days and clocks have been built around sunlight for centuries, and its pivotal influence has resulted in an ever-present yearning to study, understand and use its properties.
Egyptians used mirrors during the construction of pyramids and inadvertently discovered sunburning of the eye by ultraviolet exposure. Some of the oldest written records detail the dates of solar eclipses, such was the importance of sunlight from a very early stage in human history.
As a technology tool, light has had a significant impact in our society, far beyond even the societally-transformative invention of the light bulb.
For example, the discovery of luminescence (as in fluorescence and phosphorescence) caused a revolution in biotechnology by providing new, powerful tools for the visualization of molecular processes (as occurs in spectroscopy) and organisms as a whole (as in the bioimaging of, for example, luciferin, Aequorea victoria green-fluorescent protein, Förster resonance energy transfer (FRET) …).
Light has also played a fundamental role in environmental biology and ecology through the relationship with UV and ozone, as well as in medicine through observation of DNA damage by UV light. Of course, light is also fundamental to optics that are in everything from eyeglasses, grow lights and smartphones.
We’ve touched on the photo (light) aspect of photobiology, but what about biology? And where do the two intersect? After reading this article, you’ll have answers to these questions, and much more.
Photobiology is the study of interactions between light and living organisms.
Normally the light that is of specific interest for study is that of solar radiation reaching Earth in the ultraviolet, visible and infrared wavelengths. Photobiology is a large area of research that encompasses investigations into the nature of how organisms see (vision), how light can be harmful (as in plant phototoxicity), and how light produces energy (photosynthesis).
Photobiology has been pivotal in describing these vital biological processes, some of which we could not live without.
In plant biology, photobiology has explained how plants are able to discriminate between types of light as a function of spectrum, intensity or duration. The study of light interactions with molecules from living organisms (biomolecules) helps us understand how we can use light to improve plant cultivation.
At a nanoscopic level, molecules react with light when they absorb particles of light energy (known as photons) and go into an excited energy state. In order to regain energetic stability, molecules either react with particles around them, or they undergo conformational changes.
These two possible reactions lead us into the first and arguably most important application of photobiology, in the harvesting of energy by plants.
All living organisms need energy to keep themselves functioning. They can get energy from a wide variety of sources. Animals eat plants or other animals to absorb sugar, nutrients, protein, and fat. Fungi use decomposing matter to get their food.
Plants, on the other hand, get their energy from sunlight, CO2 absorbed in the atmosphere, and nutrients and water in the soil.
Light is the primary energy source for most plants and subsequently for most living organisms. It is essential to understand how the light-plant relationship is established and how plants convert light into usable/available and efficient energy. The light-plant relationship is crucial because the sustainability of the whole food chain depends on this initial energy production, the sequence of reactions called photosynthesis.
Photosynthesis is the process in which plants capture light and use this energy to produce sugar by consuming CO2 (carbon fixation) and releasing oxygen.
The light can come from the sun or artificial light, as long as it has the correct wavelength. The sugar produced is in the energy form most usable by a plant’s metabolism.
Plants capture most of the light in their leaves as well as in any chlorophyll-containing tissues. The light is received in the cells by a specialized cellular structure or organelle called a chloroplast. Chloroplasts are plant-specific structures and hold a high concentration of pigments, such as chlorophyll and carotenoid, that capture light. Once the incident light has been captured by the plant, a light-dependent reaction is carried out by a chain of complex enzymes embedded in membrane-bound compartments of the chloroplast called thylakoids.
These light-dependent reactions are strongly influenced by large complexes of proteins and pigments, known as photosystems (PS) and light harvesting complexes (LHC). We’ve already mentioned chlorophyll and carotenoids, which are pigments inside the photosystems, and there are others (such as xanthophylls) that are also included in the photosystem complexes. To be more specific, the photosynthetic pigments are arranged in what’s called a light harvesting complexes surrounding photosystems I and II. These two photosystems are what allow electrons to be collected from the LHC, then passed through the different complexes to produce energy.
The pigments inside a chloroplast each have a different spectrum of light that they will absorb; in other words, each pigment has a different peak and range of wavelengths of light it will respond to. There are two types of chlorophyll, chlorophyll a and b, that have spectral absorptions shifted 20 nm from one another, which combine to allow a wider light absorption bandwidth by the plants. They complement each other.
Chlorophyll a, b and carotene are inserted in the thylakoid membrane. They have different absorption spectra in the red and blue and are directly responsible for the absorption of sunlight in plant leaves.
Looking at their chemical structure, these pigments have a hydrophobic (water-hating) phytol tail that allows them to be anchored in the membranes while the porphyrin ring (head) absorbs the light. Chlorophyll b has an aldehyde functional group, whereas chlorophyll has a methyl group. These key differences determine their different absorption spectra.
Because chlorophylls are abundant in plants and absorb mainly red and blue wavelengths, they reflect green light and make leaves appear green to human eyes.
Image source: courses.lumenlearning.com/boundless-biology/chapter/the-light-dependent-reactions-of-photosynthesis
The process of photosynthesis happens in the following manner. The light incident on a plant excites electrons in chlorophyll. In order to regain energetic stability and replace its lost electrons, chlorophyll then pulls electrons from water in the reaction center. When water loses an electron, it splits apart into hydrogen and the oxygen that we breathe.
The electrons excited in chlorophyll by the absorption of light are passed along into different enzymatic complexes, also located in the chloroplast (in the thylakoid membrane) to produce NADPH and ATP (the primary energy “bricks”). NADPH and ATP are directly used in enzymatic reactions throughout all plant cells, but most importantly to perform the next phase of photosynthesis.
This phase involves CO2 assimilation into glucose (known as the Calvin Cycle) that is used directly to form cellulose, lipids, or proteins; or stored as the starch in leaves, in tubers such as potatoes, in roots such as carrots, or in the seeds. Glucose is a more stable form of energy than ATP and NADH and can be stored in long polymeric carbohydrate structures such as starch.
Image data source: khanacademy.org/science/biology/photosynthesis-in-plants/the-light-dependent-reactions-of-photosynthesis/a/light-dependent-reactions
It is well known that red light (625 nm – 675 nm) and blue light (450 nm – 485 nm) drive the photosynthesis process by causing excitation of chlorophyll within plant leaves.
In some species (i.e. radishes, cucumbers, peppers and lettuce), increasing certain flux levels of blue light can improve photosynthetic efficiency by 10 to 25%.
Light Stress in Plants
Different pigments are optimally arranged in light-harvesting complexes surrounding photosystems I and II (PSI and PSII). While chlorophyll is responsible for the primary absorption, the other pigments contribute in different ways. The carotenoids and xanthophylls support the chlorophyll by absorbing any excess light that could cause the system to be inhibited through a phenomenon called photoinhibition.
Photoinhibition is a broad term describing the decrease in the efficiency of photosynthesis when plants are exposed to an excess of light. It usually happens when PSII is saturated with photons. Carotenoids and xanthophylls help prevent this damage from occurring.
This protection system of carotenoid and xanthophylls mentioned above has limitations, however, so photoinhibition can and does still occur when the intensity of light is high enough.
When photoinhibition occurs, it can lead to a decrease in CO2 assimilation and plant growth. Any excess of light absorbed by the plant must be regulated by being re-emitted as fluorescence or heat (non-photochemical quenching). This regulation comes at a cost, specifically, an increase in water absorption by the plant. You can already see the different balancing needs of a plant that can change very rapidly.
Thus, to maximize plant growth and minimize plant stress, it is important to not only deeply understand a plant’s requirements, but be able to quickly make adjustments to the light applied.
The carotenoids and xanthophylls can only protect so far, and the plant grower needs to know when their light intensity is too high. When the light intensity is too high, the fluorescence or thermal dissipation of energy is insufficient, resulting in pigment degradation and accumulation of reactive oxygen species (ROS). ROS are molecules and free radicals that can degrade cell structures (for example mutations in a DNA sequence) when they are in abundance.
Image data source: currentscience.ac.in/Volumes/114/06/1333.pdf
Chlorophyll fluorescence can be used as an indicator of plant stress because environmental stresses (temperature or light intensity) can reduce the ability of a plant to metabolize normally.
This can mean an imbalance between the absorption of light energy by chlorophyll and the use of energy in photosynthesis (not all the light absorbed will be used in photosynthesis and so we are losing energy, which happens if we are not using the correct lighting system).
Energy absorbed by chlorophyll can be dissipated via photochemistry (photosynthesis), by heat or carotenoids activation (non-photochemical quenching), or as fluorescence. The competition between these processes allows us to determine the efficiency of PSII.
We can easily measure fluorescence with a chlorophyll fluorometer. We don’t need a laboratory or complex experiments. It can be done in the field with a portable fluorometer and it’s instantaneous. It’s a non-invasive measurement and we don’t need to sacrifice leaves or plants to get a measurement. That is why it is such a powerful variable.
To do so we can measure the Fv / Fm ratio (known as the quantum efficiency of PSII, or photochemistry efficiency). After dark adaptation (which takes anywhere from a few minutes to overnight), and under a very low light intensity (for example, the light at dawn), the minimum fluorescence is measured.
Fluorescence by chlorophyll happens when excited electrons regain stability. In other words, fluorescence happens when chlorophyll absorbs light and does not pass those excited electrons onto the light-harvesting complex. Following exposure to low light, the leaf is then submitted to intense light that will saturate and close the light harvesting complex (containing chlorophyll). Under these conditions, the maximum fluorescence (Fm) can be measured. The difference between maximum and minimum fluorescence is Fv, the variable fluorescence.
When the light harvesting centers are closed it means they are saturated and cannot pass any more electrons until they regain stability. This causes a decrease in quantum efficiency of PSII (Fv/Fm decrease).
The purpose of this behaviour (closing the light harvesting centers) is to avoid PSI photoinhibition (PSI lacks efficient repair mechanisms). It is easier for PSII to recover from photoinhibition so in order to prevent that, the flow of electrons to PSI is restricted by PSII.
The ratio of Fv/Fm represents the maximum conversion ratio (or maximum quantum efficiency) of light being usefully absorbed by the photosystems for photosynthesis. Another way to think of it is in this way: Fv indicates how much light can be absorbed by the photosystem before saturation. By dividing by Fm, we are normalizing the units to a fraction or percentage (i.e. quantum efficiency). The Fv/Fm ratio indicates how much light can be absorbed before it is lost through fluorescence (i.e. how much light is needed to saturate the light uptake of the photosystem).
The higher the Fv/Fm ratio, the greater the plant’s capacity for useful light absorption (plants are not easily saturated with light and fluorescing). When a plant is stressed, Fm decreases; that is, it can pass fewer electrons onto the light harvesting complex. A smaller Fm value results in a smaller Fv/Fm ratio (because the Fmin/Fmax value increases; see above equation).
A Fv/Fm ratio of 0.8 is considered an optimal value for most plants.
Chlorophyll molecules, when they have excited electrons that cannot be passed into the light-harvesting complex, re-emit light as fluorescence F or as heat Q.
Light damage and light stress in plants are serious issues, but thankfully plants have a few mechanisms in place for defending themselves:
- The presence of carotenoids and xanthophylls that catch excess photons (mentioned above).
- The process of self-shading. For example, when chloroplasts move into a low absorbing position, or the leaf itself moves to decrease its light exposure.
Image source: tandfonline.com/doi/full/10.1080/1343943X.2019.1673666
- The action of antioxidants (such as vitamin c and vitamin e) that capture free electrons and can thus mitigate the damage of ROS molecules and free radicals.
Whenever plants need to protect themselves from intense illumination, they are wasting energy that would otherwise go toward biomass and fruit production. Thus, light stress impacts the post‐harvest yields of crops.
Some producers will want to stress plants on purpose in order to have them produce compounds of interest that are generated under light stress conditions. For example, one might want to use UV-B to increase flavonoids quantities in fruit and berries, anthocyanin in apples and litchis or vitamin C in basil. These compounds, along with vitamin C, are major electrons scavengers and are produced by the plant to counteract the increased concentration of ROS under high light-intensity conditions.
We’ve talked about high light-intensities, but plants are stressed under low light conditions as well.
Low light intensity affects plant growth dramatically.
When photosynthesis is not fueled by an appropriate flux of photons, a plant’s ATP productivity (plant food production) is lowered. This lower energy production leads to shade avoidance symptoms (such as the elongation of stems and petioles, the stalks that attach stems to leaves), flower bud abortion, and inhibition of growth.
Finally, if low light conditions are prolonged enough, a program of leaf senescence is initiated, and the plant dies.
Photosynthetically Active Radiation (PAR)
As we discussed earlier, chlorophyll, carotenoids, and xanthophyll don’t absorb just any kind of light: they are specialized pigments with specific wavelength absorption bands. Photobiology researchers have come up with a broader term to refer to these specific wavelengths of light useful for photosynthesis: photosynthetically active radiation (PAR).
PAR is the part of the electromagnetic spectrum that is effective for photosynthesis, ranging from 400 nm to 700 nm.
It is a useful definition in photobiology because it refers specifically to the band of radiation crucial for energy production in plants. Measuring PAR will thus give a better indication of photosynthesis potential. The intensity/amount of PAR is measured by the Photosynthetic Photon Flux Density (PPFD) which is a quantification of the photons received by a surface for a given time (in units of µmol m-2 s-1). This quantity is important as photosynthesis is a quantum process where 8 to 12 photons are considered necessary for the incorporation of one CO2 molecule and the release of an O2 molecule.
Image data source: telec.co.za/forum/led-grow-lights-5/question/what-is-the-difference-between-ppf-and-ppfd-buyer-beware-10
PAR has a narrower range than the radiation of the sun that reaches the Earth’s ground and plants.
Image data source: sciencedirect.com/science/article/abs/pii/0002157171900227
The amount of PAR received by a plant could be higher than necessary or not optimum depending on the weather. There is therefore some benefit to using artificial light sources that are more stable and reliable. While there are a wide variety of light sources available for horticulture, fully-programmable LEDs make for one of the better options because of their efficiency, stability and tunability that is suitable for designing a plant-specific PAR spectrum.
It is very important to remember that the PAR spectrum as defined by McCree represents an average of 22 different plants and thus the PAR for a specific plant can be optimized by increasing or decreasing specific wavelengths as a function of the plant cultivated and the desired traits.
Indeed, the definition of PAR by McCree needs to be extended as we know now that radiation outside PAR wavelengths can improve photosynthesis. The range of photosynthetically active radiation should also be redefined for each crop.
The original McCree study reported the photosynthetically active radiation spectrum based on the quantum yield (the rate of photosynthesis per unit rate of absorption of light quanta) measured in 22 plant species using unique wavelengths (bandwidths of 10 nm to 40 nm at a time) in the range from 350 nm to 750 nm.
Wait, Aren’t Red and Blue the Best Colours for Plant Growth?
Yes, scientists agree that plants use red and blue radiation due to their high chlorophyll content, which absorbs blue and red light. It is also agreed upon that the use of radiation of both colours will enhance plant growth by making photosynthesis more efficient.
But, other wavelength regions are of major importance for plants. In fact, a lot of research has now shown that there is a synergy effect of light spectra on plant growth.
We tend to think that because the vast majority of plants on the planet look green, they reflect green radiation and thus have no use for it. Some studies, however, have revealed that green and yellow light also increase the net assimilation rate in cherry tomatoes, red leaf lettuce and cucumbers.
The influence of green and yellow light is not isolated to these specific species. Studies have shown that the plant canopy can absorb up to 80% of the green radiation received.
Other recent findings demonstrate that green radiation penetrates deeper than blue and red radiation into the leaf mesophyll (the inner tissue of a leaf) where the number of chloroplasts is higher than the leaf surface (a 10:1 ratio mesophyll chloroplasts to epidermis chloroplasts).
This higher concentration of chloroplasts results in a more efficient carbon fixation than that achieved using only red and blue radiation. Green light brings energy to deeper layers of cells in leaves or will be transmitted and distributed to other leaves deeper in the canopy. Green radiation also plays a role in providing a positional signal in addition to the quantity of blue, red and far red light that trigger the shade avoidance process.
Understanding the dynamics of light in the atmosphere, inside a group of plants and within a plant itself helps us to grow plants that are surrounded by others, and to apply light optimized for a specific plant population.
There is far more complexity to the optimal light for a plant’s food production than simply illuminating them in red and blue.
Choosing a grow light by taking into account how much of the PAR it can deliver, and how flexible it can be in adjusting the type of radiation delivered is crucial if you want to provide the best quality light to your plants.
Plant Light Perception
We’ve seen how plants absorb and use light for food production in photosynthesis. There are additional ways plants interact with light which are important for any master grower to consider, the first of which is plant perception.
Photomorphogenesis: Photoperiodism and Phototropism
Light is perceived by plants by a network of photoreceptors (also called pigments), which trigger developmental and environmental plant responses. This phenomenon is called photomorphogenesis. There are many different types of photomorphogenic responses. One example is a phototropic response, where a plant’s stem bends towards or away from a light source.
Another example is a photoperiodic response, which is a response to the length of the day and/or season(s) by modifying plant physiological processes like seed and bud dormancy, flowering and leaf maintenance.
Plants can track the time of the day and even changes between seasons. They have a memory of the day and night length like many species on earth – this is known as circadian rhythm.
A plant’s circadian rhythm is driven by the cellular expression of factors (transcription factors) that are expressed as a function of the day. There are day elements (or genes) that are repressing the night elements to allow day functions such as photosynthesis or starch production to be carried on during light exposure. When light intensity decreases and night sets in, evening elements are repressing the day elements to stop day-time activities and to carry on night activities such as starch conversion into glucose.
The two complexes (day elements and night elements) act in a feedback loop system to regulate a plant’s specific day and night activities. With this system, plants can anticipate events to come, like the transition between day and night. This is essential so plants can prepare for environmental changes like cold weather or periods without light.
On the other hand, some photoreceptors can track the origin of light and induce plant movement and growth in relation to the direction of the light in order to maximize light reception (positive phototropism) or to minimize it (negative phototropism). This is called phototropism and is regulated by photoreceptors called phototropins. These receptors absorb blue light which has the effect of changing their protein conformation. This conformational change in turn drives an accumulation of the hormone auxin at the opposite side of the light origin, or the shady side of the plant.
The accumulation of auxin leads to an elongation of the cells in the plant’s shady side, with the ultimate result of bending the stem toward light. Sunflowers are a beautiful example of plants following sunlight.
The phototropic response allows plants to optimize their exposure and carbon gain, to protect themselves from too much light and to find a light source when seedlings are germinating.
In plants, photoreceptors can be divided into 4 families each containing several members, each of which will be discussed in more detail below:
- Phytochromes (PhyA to PhyE)
- Cryptochromes (CRY1, CRY2 and CRY3)
- The Light-oxygen-voltage (LOV)-domain photoreceptor family
- Phototropins (PHOT1 and PHOT2)
- ZTL/FKF1/LKP2 group proteins
- UV-B resistance 8 (UVR8)
These photoreceptors sense all different kinds of light cues (intensity, spectra, photoperiod).
They all contain a chromophore, which is a part of a molecule sensitive to light (for example, the porphyrin ring in chlorophyll). The chromophore can be excited by light and allows a circulation of electrons which can lead to modification of a molecule’s conformation (as in dimerization, joining two into one, for example). The excitation of a chromophore can also allow electrons to simply jump to another molecule. This generally triggers an intracellular signaling cascade.
The intracellular signaling cascade is a series of reactions between molecules inside a cell that induces a response to a given stimulus. When the sun’s radiation reaches a plant cell, photoreceptors located on the leaf surface or inside the cells are activated by excitation of their chromophore part. This activates or represses different types of molecules that can regulate gene expression. This regulation of gene expression eventually leads to the degradation or production of new molecules that induce a response to this light radiation.
Phytochromes are pigments that absorb light in the red and far-red region of the visible spectrum.
They regulate the synthesis of chlorophyll, the germination of seeds, the elongation of seedlings, the timing of flowering in adult plants, as well as the size, shape, number and movement of leaves.
Phytochromes are expressed across many tissues (flower, leaves, roots) and developmental stages (seed coat, cotyledons, inflorescence). Red light and far-red light can be applied to trigger phytochrome activity and regulate these physiological processes.
Phytochromes absorb red light at about 660 nm and far-red light at 730 nm, and they react to the ratio of red to far-red light intensity.
On a clear day around noon, the red to far-red ratio (R:FR) in natural daylight is close to 1. Essentially, this ratio signals if a plant is shaded by other plants in the vicinity. In this case where a plant is shaded by another, because far-red radiation is able to penetrate more deeply into the canopy (while red and blue radiation are absorbed), more far-red radiation will be detected by phytochromes (Pr to Pfr). This detection will trigger shade avoidance behavior such as stem elongation and the development of smaller leaves and branches. These responses are achieved through the redistribution of resources from the leaves to the stem.
Pfr conversion to Pr (R:FR low) increases apical dominance which decreases development of basal branching (apical dominance is when the terminal bud is inhibiting the growth of the secondary axillary bud by the controlled release of auxin hormone). Finally, the detection of far-red by the phytochrome affects leaf biomass and chlorophyll quantity. It also speeds up the transition to flowering which results in earlier seed production (this was originally observed in Arabidopsis thaliana). The red to far-red ratio (R:FR) could also play an important role in fruit quantity and morphology as studies have shown that in tomatoes FR increased (R:FR 0.88 to 0.7) can boost fruit biomass by up to 59%. However, there is still more work to be done as too few studies have investigated the dose effect of R:FR.
The red to far-red ratio is a good example of how plants glean detailed information from the spectrum with which they are illuminated.
The R:FR ratio is such an important signal that it can also affect a plant’s seed germination, where too much far-red radiation has been shown to inhibit germination in some species. Red and Far-Red radiation penetrate deeper into the soil than other radiation.
In an open space, red activates Phytochrome B (PhyB) and germination is initiated. If the far-red is high (under a dense canopy) some seeds can’t germinate. It’s therefore a very efficient way for plants to detect favorable conditions. However, in some species, Phytochrome A (PhyA) and PhyB are triggered under low fluence R light (PPFD < 10) to mediate germination. This is the case for Arabidopsis thaliana and tomatoes.
In addition to far-red radiation, the specific PhyA phytochrome is also activated by blue light in seedlings when uniteral blue light irradiation is low (observed in treatments as low as 0.5 PPFD).
It is important to note that phytochromes act as a dimer so we can find phytochromes in 3 different forms depending on which base molecules were joined into a pair. This gives plants several degrees of sensitivity to Red and Far-Red levels. This conformational change is a function of the light quantity (intensity), the ratio of R:FR as well as by temperature. For example, at low temperatures, Pfr reverses to Pr.
Image source: nature.com/articles/s41467-019-13045-0
Cryptochromes are pigments that are sensitive to blue light and UV-A.
They play a predominant function during de-etiolation (the transition to the greening stage after plant germination) (Cryptochrome-1 CRY1), in the photoperiodic control of flowering (Cryptochrome-2 CRY2), in the inhibition of the hypocotyl growth or in shade avoidance (CRY1 and CRY2).
Cryptochromes sense light with their chromophore which is a flavin adenine dinucleotide (FAD). Following light activation, they photodimerize (CRY1-CRY1) or oligomerize (CRY1-CRY2) and then bind to effectors (Cry-binding proteins) that will promote de-etiolation, transition to flowering (for CRY1) or senescence (for CRY2). It is important to note that CRY activation can lead to different plant responses depending on the plant species (CRY1 promotes flowering in soybean while CRY2 is responsible for flowering initiation in tomato and peas).
During the shade avoidance process in plants it has been established that under low blue light conditions, the interaction between CRY and PIFs is weakened, allowing PIFs (Phytochrome-Interacting Factors) to promote stem elongation.
Recently it has been demonstrated that cryptochromes are involved in different stress acclimation responses to events such as drought or hyperosmotic stress (where the plant’s surrounding liquid has a higher solute concentration) through modulation of CRY activity by a hormone-dependent signaling pathway. CRY activity could promote a protective effect during the above-mentioned abiotic stresses. Another protective effect CRY can promote is to induce hypocotyl growth through activation of the transcription factor PIF4 (PHYTOCHROME INTERACTOR FACTOR 4) under warm conditions, which would allow a better heat dissipation. Transcription factors are molecules which interact directly with genes to promote or inhibit their transcription. PIF4 here will directly interact with DNA coding for proteins involved in plant growth, and activate their production.
In other words, a plant’s light response is also modulated by its ‘’stress’’ state, emphasizing the importance of the environment on plant photobiology (see Phytochrome and temperature effects).
The LOV-domain photoreceptor family
The light, oxygen, or voltage (LOV) family of blue-light photoreceptors is a family of proteins present across all kingdoms of life (fungi, plants and bacteria) in which blue light photoexcitation of their LOV-domain lead to a biological signal (structural and dynamical changes and binding to other proteins).
Phototropins are the first type of LOV-domain photoreceptors we’ll discuss. They are blue-light receptors controlling a range of responses to optimize the photosynthetic efficiency of plants. These responses include phototropism, light-induced stomatal opening, and chloroplast movement in response to changes in light intensity. Stomatal opening is when stomata (pores located in the plant epidermis), open to allow gas exchange: the absorption of CO2 and the release of O2.
This gas exchange is extremely important for energy production, as it allows CO2 uptake and its transformation into glucose following photosynthesis.
One of the most impressive phenomena associated with phototropin photoreceptors is their role in phototropism. Phototropism occurs when plants bend toward or away from light. This response is possible because part of the plant stem in the shaded side has increased growth.
This growth is due to a gradient of activation of a specific phototropin, PHOT1. The blue light crossing the stem section is refracted and the shaded side receives less light. The PHOT1 phototropin is not active in the dark, and since it plays a role in the degradation of the auxin hormone, there is a corresponding gradient in the auxin hormone. The accumulation of auxin in the shaded parts of the stem directs growth that bends a plant toward light.
Zeitlupe (ZTL) Photoreceptors
The second type of LOV-domain photoreceptors are the Zeitlupe photoreceptors. ZEITLUPE, FLAVIN-BINDING KELCH REPEAT F-BOX 1, and LOV KELCH PROTEIN 2 (ZTL/FKF1/LKP2) group proteins are blue receptors involved in light-mediated protein degradation by ubiquitination (the attachment of a ubiquitin protein) during the circadian rhythm.
They are often described in terms of their domains, where domains are specific sequences of amino acids or DNA bases that have functional roles. All the Zeitlupe photoreceptors contain a light, oxygen, or voltage domain (LOV-domain) along with domains involved in protein stability (F-box and Kelch repeat domains). As a function of the time of the day, the Zeitlupe photoreceptors promote degradation or maintenance of circadian transcription factors and induce transitions in the day to dark cycle.
These photoreceptors act directly in response to light activation to regulate gene expression. Under blue light the Zeitlupe photoreceptors bind to transcription factors to stabilize them. In the dark this interaction is weakened, so the transcription factors are not protected and are therefore sent for degradation by the cell.
For example, ZTL late at night triggers the degradation of major components of the circadian rhythm (TOC1 and PRR5 proteins) that normally maintain the plant in an optimum physiological state in which to pass the night. With the late-night decrease of the concentration of these factors as a result of ZTL, the plant can then shift to day functions.
During each transition from day to night or night to day, the detection of light triggers or inhibits genes that control day (phototropism) or night events (cell wall biosynthesis, for example). All three LOV-containing F-box proteins (ZTL, FKF1, and LKP2) are involved in circadian clock events such as day/night transitions or day-length-dependent flowering.
There is still a huge gap in understanding how these proteins act at the level of the whole plant, and further research is needed to determine whether variations in blue light or other wavelengths influence the expression of these proteins.
Recently, more attention has been given to a receptor in the ultraviolet (UV) wavelength region, UV RESISTANCE LOCUS8 (UVR8). UVR8 is a photoreceptor sensing UV-B radiation (with an absorption peak at 285 nm).
It is the most recent photoreceptor characterized. This is an interesting discovery because for a long-time plants were thought to only have receptors in the visible spectrum.
Around 7% of all solar radiation reaching earth is UV, and UV-B (280 nm to 315 nm) is the most harmful to plants, being capable of breaking a molecule’s chemical bonds resulting in the production of highly reactive molecules or ROS.
When UV-B reaches plant cells, UVR8 is activated and is involved in photomorphogenic response and defense mechanisms.
UVR8 is responsible for mitigating the effect of UV-B on plants. Upon activation, UVR8 triggers the production of compounds involved in oxidative stress protection such as phenols, terpenes or anthocyanins and can even enhance a plant’s defense against herbivores.
Image Data Source: doi.org/10.1016/j.semcdb.2019.03.007
Light Effect of Phytochemical Production
So far we’ve given an overview of the many different responses and pathways triggered and managed by plants interacting with light. While there is still much research that remains to be done, there are very practical outcomes that have already been gleaned through these insights into what’s happening inside each individual plant cell under illumination.
Researchers are now using these discoveries to better control and regulate the spectra under which they grow their plants, and looking at the specific effect it has on chemicals related to metabolic pathways (metabolites).
Studies have reported many interesting results regarding the increased production of secondary metabolites in response to the regulation of the light spectrum.
In Cannabis, for example, it was found that LED use could increase THC up to 38% compared to cannabis plants grown under high pressure sodium lamps (HPS). CBD was also increased by up to 35% under LED compared to HPS.
THC and CBD are phyto-compounds that have therapeutic values including anti-inflammatory and analgesic properties and can also be used to suppress vomiting, nausea and appetite. An increase from 15 to 32% in the THC content of Cannabis leaf and flowers was recorded after their exposure to UV-B radiation.
In basil, a properly matched light spectrum increased antioxidant capacity, phenolics and flavonoids by up to 16.3%, 28.8% and 41%, respectively, while reducing concentration of harmful compounds like nitrate by up to 41.6% showing that volatile compounds can also be manipulated by light.
Plant Disease Prevention
One of the interesting findings from testing specific light recipes is the effect of light on protection against disease.
Promising results have been shown on strawberries, tomatoes, cucumbers and peppers, all of which are especially affected by fungi in greenhouses.
Pathogens such as fungus (grey mold, powdery mildew) can cause great losses in crop production (10-15% yield loss in North America, according to the British Columbia Ministry of Agriculture).
It has been reported that UV-B light suppresses powdery mildew infection in strawberries by stimulating genes associated with disease resistance. Grey mold development on tomato leaves was suppressed by 63% with violet light application.
Light application could become a regular practice in the future, allowing the control of pathogen infections without using chemical methods.
It is extremely important to remember that all of the photoreceptors discussed in this article act in synergy to transmit information to the plant about the ambient/environment light conditions.
Because of this array of photoreceptors, plants can detect light from UV to IR, not only determining their intensities, but also sending signals about the time of exposure. Some photoreceptors are also sensitive to temperature. Plants can then sense and adjust to light changes such as the day/night transition. These light-sensitive adaptations can range from physiological to morphological adjustments.
Plants can elongate when they need to compete with other plants to reach sunlight on top of the canopy, or they can move their chloroplasts and leaves to avoid light damage at the cost of biomass production. Ultimately, plants thrive under optimum conditions of spectra, intensity and photoperiod exposure.
Ideally, you will want to adjust the amount, spectrum and time exposure of light according to the cultivar used (depending specifically upon general plant morphology as well as the quantity and type of photoreceptors), the stage of development (seedling to flowering), and the environment of cultivation (CO2 content, temperature, humidity). All of these parameters are essential for light use optimization.
- An increase in red light for certain plants (tomatoes, lettuce) can boost germination (helping seeds with lower storage reserves to germinate faster or, if used in reverse, to reduce the germination rate).
- A change in the photoperiod to induce flowering (for example, a transition from long 16-hour light days to shorter 12-hour light days to induce flowering in cannabis or chrysanthemum) or encourage leaf growth (cannabis).
There is some level of redundancy and cross talk in the light sensing and signaling pathways that make LED fine tune programming necessary to maintain desired crop qualities.
Frequently Asked Questions
Q: What is the value of variable spectra – what does it do for me?
Answer: Variable spectrum lighting can improve your plant growth considerably.
When you control the spectra of your light you can apply light best suited for your plant and save energy by not generating any light your plant doesn’t need.
By controlling the amount of each wavelength, an increase in yield up to 34% was reported in lettuce cultivation. In strawberries, maximum fruit production increased by 66% when the optimum level of red, blue and white light was attained. There is clearly a value in being able to adjust the light as a function of your crop species and also as a function of their growth stage.
As we explain in the article, seedlings have different needs (low intensity, more red) compared to mature or flowering plants.
Q: Can artificial lighting be better than the sunlight?
Answer: Since the start of agriculture, people have relied upon sunlight to grow their crops, and it still does a good job. The challenge is that sunlight is just not always available. Crops depend on seasons and weather, and during winter it’s simply not possible to grow outside.
Horticultural lighting is stable and reliable in intensity. With advanced lighting technology and research into photobiology, we can now design them with the perfect spectra and at the same time remove harmful radiation such as UV.
Q: What is the perfect spectrum for plant cultivation?
Answer: It is well known now that plants perform at their best under some ratio of blue and red.
Blue will encourage chlorophyll light absorption, photosynthesis, and growth while red radiation will also promote photosynthesis, growth and elongation.
However, UV-B, Green, yellow and IR can have various positive effects that can’t be neglected. Green penetrates deeper into the canopy while UV can trigger the production of specific metabolites that can have agronomic interest. Keep in mind that each plant has its preferred spectrums and that a full programmable lighting system will be the best at providing the best spectra throughout the life of your plants.
Q: How much light do plants need?
Answer: Usually, the light intensity required by a plant depends on the stage of growth and the plant species.
Sunlight intensity is between 900 and 1500 PPFD (micromoles per square meter per second).
Seedlings and small plants require between 100 and 200 PPFD. During vegetative growth, 400 and 600 PPFD is good for the development of the canopy. For flower and fruit development you can increase light intensity to 900 PPFD.
After 900 PPFD most plants will be limited by the amount of CO2 in the atmosphere and they won’t be able to use all the light. Every light intensity change should be made gradually so you don’t stress your plants and you can see what is the maximum limit specific to your plants.
Q: Can we grow plants under continuous light?
Answer: It is possible to grow certain plants under 24-hour light. But most plants will require a dark period. In the dark, they can recover, allocate resources for tissue reparation and prepare for the following day. Also, most importantly, some plants require periods of darkness to initiate flowering.
Some growers will grow their plants under a 24-hour light regime to a certain stage of growth and then add a darkness hour to trigger flowering. Most of the plants are grown under 12 to 18-hour light which leaves between 12 and 6-hours of dark.
- Light is the energy source for photosynthetic organisms such as plants or algae.
- Photons from light drive the photosynthesis reaction that allows the storage and the conversion of light energy into the form of glucose made from CO2 assimilation
- Plants can detect several light parameters through their very sophisticated photoreceptors such as wavelength, exposure time or light intensity, which is why quality lighting is essential to grow plants
- Inappropriate amounts or types of radiation (UV) can stress plants and even kill them
- For every plant, every species, and at each stage of development there is an optimal light condition
- Plants have evolved to recognize, anticipate and adapt to light changes.
- Light variations are translated into morphological and physiological outcomes in plants that are essential for their survival:
- Metabolites (vitamins, terpenes, anthocyanin…)
- Fruit production |
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- Students revisit the fundamental theorem of algebra as they explore complex roots of polynomial functions. They use polynomial identities, the binomial theorem, and Pascal’s Triangle to find roots...
- This module revisits trigonometry that was introduced in Geometry and Algebra II, uniting and further expanding the ideas of right triangle trigonometry and the unit circle. New tools are introduced... |
Domestic violence is the wilful intimidation, physical assault, battery, sexual assault, and/or other abusive behaviour as part of a systematic pattern of power and control perpetrated by one intimate partner against another. It includes physical violence, sexual violence, psychological violence, financial and emotional abuse. The frequency and severity of domestic violence can vary dramatically; however, the one constant component of domestic violence is one partner’s consistent efforts to maintain power and control over the other.
Domestic violence is an epidemic affecting individuals in every community, regardless of age, economic status, sexual orientation, gender, race, religion, or nationality. It is often accompanied by emotionally abusive and controlling behaviour that is only a fraction of a systematic pattern of dominance and control. Domestic violence can result in physical injury, psychological trauma, and in severe cases, even death. The devastating physical, emotional, and psychological consequences of domestic violence can cross generations and last a lifetime.
Some examples of abusive tendencies include but are not limited to:
- Telling the victim that they can never do anything right
- Showing jealousy of the victim’s family and friends and time spent away
- Accusing the victim of cheating
- Keeping or discouraging the victim from seeing friends or family members
- Embarrassing or shaming the victim with put-downs
- Controlling every penny spent in the household
- Taking the victim’s money or refusing to give them money for expenses
- Looking at or acting in ways that scare the person they are abusing
- Controlling who the victim sees, where they go, or what they do
- Dictating how the victim dresses, wears their hair, etc.
- Stalking the victim or monitoring their victim’s every move (in person or also via the internet and/or other devices such as GPS tracking or the victim’s phone)
- Preventing the victim from making their own decisions
- Telling the victim that they are a bad parent or threatening to hurt, kill, or take away their children
- Threatening to hurt or kill the victim’s friends, loved ones, or pets
- Intimidating the victim with guns, knives, or other weapons
- Pressuring the victim to have sex when they don’t want to or to do things sexually they are not comfortable with
- Refusing to use protection when having sex or sabotaging birth control
- Pressuring or forcing the victim to use drugs or alcohol
- Preventing the victim from working or attending school, harassing the victim at either, keeping their victim up all night so they perform badly at their job or in school
- Destroying the victim’s property
- It is important to note that domestic violence does not always manifest as physical abuse. Emotional and psychological abuse can often be just as extreme as physical violence. Lack of physical violence does not mean the abuser is any less dangerous to the victim, nor does it mean the victim is any less trapped by the abuse.
Additionally, domestic violence often intensifies because the abuser feels a loss of control over the victim. Abusers frequently continue to stalk, harass, threaten, and try to control the victim after the victim escapes. In fact, the victim is often in the most danger directly following the escape of the relationship or when they seek help: 1/5 of homicide victims with restraining orders are murdered within two days of obtaining the order; 1/3 are murdered within the first month.2
Unfair blame is frequently put upon the victim of abuse because of assumptions that victims choose to stay in abusive relationships. The truth is, bringing an end to abuse is not a matter of the victim choosing to leave; it is a matter of the victim being able to safely escape their abuser, the abuser choosing to stop the abuse, or others (e.g., law enforcement, courts) holding the abuser accountable for the abuse they inflict.
Victims of domestic violence may:
- Want the abuse to end, but not the relationship
- Feel isolated
- Feel depressed
- Feel helpless
- Be unaware of what services are available to help them
- Be embarrassed of their situation
- Fear judgement or stigmatization if their reveal the abuse
- Deny or minimize the abuse or make excuses for the abuser
- Still love their abuser
- Withdraw emotionally
- Distance themselves from family or friends
- Be impulsive or aggressive
- Feel financially dependent on their abuser
- Feel guilt related to the relationship
- Feel shame
- Have anxiety
- Have suicidal thoughts
- Abuse alcohol or drugs
- Be hopeful that their abuser will change and/or stop the abuse
- Have religious, cultural, or other beliefs that reinforce staying in the relationship
- Have no support from friends of family
- Fear cultural, community, or societal backlash that may hinder escape or support
- Feel like they have nowhere to go or no ability to get away
- Fear they will not be able to support themselves after they escape the abuser
- Have children in common with their abuser and fear for their safety if the victim leaves
- Have pets or other animals they don’t want to leave
- Be distrustful of local law enforcement, courts, or other systems if the abuse is revealed
- Have had unsupportive experiences with friends, family, employers, law enforcement, courts, child protective services, etc. and believe they won’t get help if they leave or fear retribution if they do (e.g. they fear losing custody of their children to the abuser)
- These are among the many reasons victims of domestic violence either choose to stay in abusive relationships or feel they are unable to leave.
Abusers come from all groups, all cultures, all religions, all economic levels, and all backgrounds. They can be your neighbour, your pastor, your friend, your child’s teacher, a relative, a co-worker — anyone. It is important to note that the majority of abusers are only violent with their current or past intimate partners. One study found 90% of abusers do not have criminal records and abusers are generally law-abiding outside the home.
There is no one typical, detectable personality of an abuser. However, they do often display common characteristics.
An abuser often denies the existence or minimizes the seriousness of the violence and its effect on the victim and other family members.
An abuser objectifies the victim and often sees them as their property or sexual objects.
An abuser has low self-esteem and feels powerless and ineffective in the world. He or she may appear successful, but internally, they feel inadequate.
An abuser externalizes the causes of their behaviour. They blame their violence on circumstances such as stress, their partner’s behaviour, a “bad day,” on alcohol, drugs, or other factors.
An abuser may be pleasant and charming between periods of violence and is often seen as a “nice person” to others outside the relationship.
Red flags and warning signs of an abuser include but are not limited to:
- Extreme jealousy
- A bad temper
- Cruelty to animals
- Verbal abuse
- Extremely controlling behaviour
- Antiquated beliefs about roles of women and men in relationships
- Forced sex or disregard of their partner’s unwillingness to have sex
- Sabotage of birth control methods or refusal to honour agreed upon methods
- Blaming the victim for anything bad that happens
- Sabotage or obstruction of the victim’s ability to work or attend school
- Controls all the finances
- Abuse of other family members, children or pets
- Accusations of the victim flirting with others or having an affair
- Control of what the victim wears and how they act
- Demeaning the victim either privately or publicly
- Embarrassment or humiliation of the victim in front of others
- Harassment of the victim at work
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Cockroaches are not only undesirable pests but a threat to human health by consuming our food and contaminating the indoor environment.
Cockroaches are known to transfer disease pathogens, such as the various bacteria that produce “food poisoning” in humans, by contaminating food, food preparation surfaces, dishes and eating utensils. How many human gastrointestinal disorders are attributed to the mechanical transmission of pathogens by cockroaches has not been fully assessed, but remains a valid health concern. However, the roach’s greatest impact on human health may be its ability to trigger asthma. Cockroach nymphs grow by periodically shedding their “skin” (the exoskeleton). Fragments of their exoskeletons, along with bits of cockroach feces, serve as antigens (foreign protein) that, when inhaled, cause allergic and asthmatic reactions.
Several species of cockroaches live inside structures. Most domestic cockroaches are of tropical origin and the German cockroach, for one, cannot survive temperate winters outdoors. All are primarily nocturnal. All prefer warm, moist places where they can feed on human and pet foods, decaying and fermenting matter, and a variety of other items.
Food, water and shelter are basic roach requirements. With all three present in sufficient quantity, cockroaches grow and reproduce with mated females producing oothecae – pillow-shaped egg capsules each containing up to 48 eggs. Tiny, wingless nymphs hatch from their eggs and gradually grow into adult roaches.
The German cockroach (Blatella germanica) is by far the most common roach found in kitchens. It is a half-inch long, bronze-colored insect that avoids light and hides in cracks and crevices. Adults and older nymphs have two black stripes on the back just behind the head.
German cockroaches spend about 75 percent of their lives in hiding. Enabled by a body that’s smaller than other species, the ability and inclination to hide in tiny spaces is one reason why the German cockroach has been so successful at living with humans. Coming out of hiding to feed or to mate can be dangerous, so it’s usually done in darkness. When the roaches leave their hiding spots, they only go as far as they need to find food and mates. Their hiding places are usually within 10 feet of their food source.
Another characteristic lending success to the German cockroach is its rapid reproduction. Unlike other roaches that drop their egg capsules days before the eggs hatch, the female German roach goes into hiding, holding the egg capsule on the end of her abdomen until the eggs are about 24 hours from hatching. This method of protecting the eggs, coupled with the relatively large numbers (30 to 48) of eggs per capsule, allows German cockroach populations to build quickly, such that about 80 percent of roaches in a growing population are nymphs.
The German cockroach prefers to live close to its own kind. Prime hiding places can be occupied by many roaches. Large numbers can be found clustering together under stoves, refrigerators and dishwashers, and in wall and cabinet voids. Roaches defecate in such places, leaving dark speckling that contains pheromones – scent signals that mark a surface as a “fecal focal point” where roaches will gather.
The Oriental cockroach (Blatta orientalis) is the so-called “waterbug” of basements, crawlspaces and garages. It lives in cooler habitats with plenty of moisture – even outdoors around foundations in leaves and mulch where it can survive temperate winters. As a result, the Oriental cockroach’s development is slower. They require an average of 18 months to progress from egg to adult, while the German cockroach averages only two months to adulthood. In addition, the Oriental’s egg case contains 16 eggs, compared to the German’s 30 to 48 eggs per case. After being detached from the female, eggs inside the Oriental roach’s egg case require an average of two months to hatch.
Oriental cockroaches also differ in appearance. Newly hatched nymphs are brown and become blackish as they grow. Adults are up to 1 ¼ inches long with wide, flat bodies and no distinguishing markings. Males have wings that cover about half of the abdomen and females have only wing stubs; neither sex can fly.
The American cockroach (Periplaneta americana) is a large species, up to 2 inches long. It is reddish brown, but lighter around the edges of the thorax. Adults have wings extending to the end of the body. They can fly in temperatures above 85 F.
American cockroaches are less common in homes than German cockroaches. They prefer sewers and boiler rooms, basements and steam tunnels in commercial establishments, especially where food is processed or prepared.
American cockroaches develop much slower than German cockroaches. The American’s egg case contains 14 eggs to 16 eggs. Females deposit them, often near food sources, where the eggs typically hatch in about 45 days. Average time from egg to adult is about 15 months. Nevertheless, large populations can develop under favorable conditions.
This cockroach is sometimes encountered indoors, but it prefers higher temperatures (about 80 F) than the much more common German cockroach. It loves the warmth of electronics, motor housings, light fixtures, and ceilings. When German cockroaches are found in nonfood areas (such as bedrooms), this may indicate a heavy infestation, lack of hiding places, or use of a repellent pesticide – but such harboring in nonfood areas is typical of the brownbanded roach.
Brownbanded cockroaches (Supella longipalpa) are slightly smaller than German cockroaches and more colorful. Males are a golden orange color with a broad band of dark brown. They can fly, with wings that cover their abdomens. Females are darker overall, with lighter bands on the abdomen. They have shorter wings and cannot fly. Nymphs are dark with cream-colored bands behind the head, and are golden orange over much of the abdomen. Nymphs and adults may jump when disturbed.
“Woods cockroach” is a common name applied to certain roaches, including Parcoblatta species that live outdoors and occasionally enter structures. Males are usually less than an inch long with wings extending beyond the tip of the abdomen. They are strong fliers, typically encountered in homes during the spring mating season after being attracted to lights associated with the structure. Woods roaches also are brought in on firewood. Outdoors they can be found in woodpiles, stumps, logs and trees.
Cockroach infestations are rarely eliminated by using only one method of control, for example, by pesticide application alone. Similarly, infestations are rarely eliminated by the use of only one pesticide product without follow-up inspections and treatment.
Where long-term management or elimination is the goal, the principles of Integrated Pest Management (IPM) should be applied. Beginning with inspection, all effective means of non-chemical control should be utilized, including exclusion and sanitation.
A thorough inspection requires use of a good flashlight and often other tools, such as a mechanic’s mirror for inspecting voids difficult to access, probing tools, and a flushing agent (typically an aerosol containing pyrethrins). Inspect for signs of roach activity, such as dark speckling found where German cockroaches gather. Others signs include cockroach consumption of foods and the presence of cockroach egg cases and shed “skins.” These signs of infestation can help pinpoint where the roaches are living. The use of pest monitors (“sticky traps”) also can reveal valuable information by helping to locate areas of roach activity. The use of monitors should continue even after cockroaches are believed to be eliminated. Leaving traps in place and checking them regularly can help confirm elimination, and give early warning of the presence of new roaches in time to control them before the population builds.
Cockroach hiding places often lie within a few feet of their food source. Look in areas that offer warmth, food, moisture and shelter. Remember roaches prefer natural surfaces such as wood and cardboard.
Younger nymphs typically do not venture more than 2 feet from their hiding places. Adults usually roam less than 10 feet from harborage in search of food, though a female carrying an ootheca may not move or feed until the egg case is detached. Obviously, knowing how the various stages of roaches in a population move is of great significance to any management plan, as are thorough inspections, good sanitation and exclusion, as well as the appropriate selection and use of pesticides.
Exclusion means reducing cockroach movement and hiding places. It may not be possible to seal all avenues of cockroach movement or deny them the use of all potential hiding places. But this does not lessen the value of exclusion. Every effort should be made to do as much exclusion as is practical.
In dwellings with shared walls, such as apartment buildings, preventing cockroach movement between rooms and units is important. German cockroaches typically move through shared walls, for example, through gaps around pipes under sinks. These gaps should be filled with materials such as silicone sealant or urethane foam. In some instances, American or Oriental cockroaches may be living around the outside of the structure or in adjacent structures. In such cases, the building’s exterior should be inspected to find and seal points where roaches can gain access to the building’s interior.
Similarly, roaches can be excluded from hiding places by sealing the cracks, crevices and holes through which roaches access the secluded spots where they spend most of their time.
The ultimate goal of sanitation is to remove all sources of food and water from the cockroach’s environment. As with exclusion, this goal is usually not fully achieved, yet every effort should be made to remove as much food and water sources as is practical. While good sanitation and exclusion alone rarely ensure cockroach elimination, these two methods enhance the effectiveness of pesticide application. If dirt, grease and moisture are not removed, they can interfere with the effectiveness of pesticides. Also, insecticides such as baits perform better when alternative sources of food are unavailable. Roaches not only feed on the baits, but also forage farther, potentially exposing themselves to pesticide-treated surfaces. On the contrary, in situations where sanitation is poor, there is typically a greater reliance on pesticide, i.e., more pesticide use and thus a greater potential for misuse and human exposure.
Steaming and vacuuming can be a valuable means of sanitation, in addition to killing and physically removing cockroaches from a structure. Steam units and vacuums designed for insect control are available and effective, especially in heavily infested areas.
Applying an insecticide according to label directions, sufficiently close to where cockroaches are hiding, is as important as selecting the best pesticide for the job. Even the best insecticides will not be effective if roaches are not exposed to them or do not discover bait placements. Thorough inspections are necessary to find where roac bhes are hiding so that bait can be placed close enough for the roaches to find and consume it.
Unfortunately, pesticide products continue to be misused. One particular hazard are total-release aerosols, commonly known as “foggers” or “bombs." These products can be counterproductive because they often do not penetrate far enough into roach hiding places to kill the roaches, and they can cause roaches to scatter and spread to new locations. Worse still is the total-release aerosol’s potential for overuse in confined spaces where ignition sources (e.g., burning cigarettes, pilot lights) make them a significant fire and explosion hazard.
Since the 1980s, new cockroach bait products have changed cockroach management. Available in a variety of brands and formulations from gels applied by syringe-type applicators to granular products, baits have replaced the routine baseboard spraying and fogging of the prebait era. With the availability of effective baits, relying on baseboard spraying to control cockroaches disregards the most effective means of cockroach control.
While baits are effective against cockroaches, as with other types of pesticides, one product should not be used over long periods of time. Cockroaches have shown some avoidance of bait products, and even resistance (having the ability to survive after feeding on bait). Cockroach resistance problems can be delayed or avoided by using one pesticide product for a few months before switching to a dissimilar product.
Cockroach control does not require the services of a pest management professional, though it is often best to hire a professional, especially for heavy infestations in complex or sensitive environments (see “Pest Control: Do It Yourself or Hire a Professional”). While most consumers can perform adequate sanitation and exclusion, cleaning and sealing, the over-the-counter selection of pesticides is limited compared to the number of products available to, and designed for use by, pest management professionals. Specialized equipment and pesticides useful in cockroach control, such as dust applicators, microencapsulate formulations, and insect growth regulators, are typically not available to consumers. Granular products for treating around foundations where American and Oriental cockroaches may occur, boric acid dusts, various liquid residual pesticides, and some gel and containerized roach baits, can be purchased in retail stores and used effectively by consumers who follow label directions.
Note that dusts, such as those containing boric acid, are often sold in squeeze bottles that can easily dispense too much product if used incorrectly, leaving unsightly and ineffective piles of powder. Dust should be applied to cracks and voids as a thin, barely visible layer. With gel and container baits for cockroaches, the opposite is true. Many placements should be made at the corners and edges of shelves, and under sinks, wherever roaches are hiding. With bait stations, a dozen or more should be used in infested kitchens. Likewise, many placements of gel or other roach baits should be used. Apply gel baits in small drops – not as thick, continuous lines like caulking. Do not contaminate baits by storing them near other pesticides or by spraying on or near stations and bait placements. Once dusts or bait are applied, be patient. It can take several days for roaches to die, particularly from exposure to dusts, and for roach populations to be noticeably reduced.
Along with sanitation and exclusion, today’s German cockroach management plans rely on the effectiveness and correct use of bait and dust formulations (e.g., dusts containing boric acid, silica, or diatomaceous earth), along with spot and crack-and-crevice applications of residual liquid pesticides. Pesticide application is almost always a part of an effective cockroach management plan. Combining pesticide use with nonchemical methods, the effectiveness of each is method is enhanced, and cockroach management maximized.
Photographs and illustrations courtesy of University of Nebraska, University of Arkansas, respectively.
NOTE: When pesticides are used, it is the applicator’s legal responsibility to read and follow directions on the product label. Not following label directions, even if they conflict with information provided herein, is a violation of federal law.
For more information, contact the Illinois Department of Public Health, Division of Environmental Health,
525 W. Jefferson St., Springfield, IL 62761, 217-782-5830, TTY (hearing impaired use only) 800-547-0466. |
Ankle Brachial Index Test
What is an ankle brachial index test?
The ankle brachial index, or ABI, is a simple test that compares the blood pressure in the upper and lower limbs. Health care providers calculate ABI by dividing the blood pressure in an artery of the ankle by the blood pressure in an artery of the arm. The result is the ABI. If this ratio is less than 0.9, it may mean that a person has peripheral artery disease (PAD) in the blood vessels in his or her legs.
In PAD, plaque builds up in the arteries. It often affects the vessels that bring blood to the legs. The reduced blood flow can cause pain and numbness. Low ABI may mean that your legs and feet aren’t getting as much blood as they need. An ABI test won’t show exactly which blood vessels have become narrowed or blocked, though.
During an ankle brachial index test, you lie on your back. A technician takes your blood pressure in both of your arms using an inflatable cuff, similar to the one used in the doctor’s office. The technician also measures the blood pressure in the ankles. The doctor uses these values to compute your ABI.
Why might I need an ankle brachial index test?
Your healthcare provider might want you to have an ABI test if you are at risk for PAD. The ABI test can:
- Diagnose PAD and prevent its progression and complications
- Identify people who have a high risk for coronary artery disease
Things that can increase your risk for PAD include:
- Being older than age 70
- High levels of lipids in your blood
- Known plaque formation in other arteries, like the coronary arteries in your heart
- Abnormal pulses in your lower legs
- Being younger than age 50, with diabetes and one additional risk factor, such as smoking or high blood pressure
Your healthcare provider also might recommend an ABI if you have symptoms of PAD, like pain in the legs with activity. But not everyone with PAD has symptoms. This makes the test even more important.
You also might need an ABI to check the severity of your PAD. Your provider might order this test every year, to see if your condition is getting worse.
If you’ve had surgery on the blood vessels of your legs, your provider might want an ABI to see how well blood is flowing into the leg. Sometimes healthcare providers use ABI to assess your risk of future heart attack or stroke.
What are the risks for an ankle brachial index test?
For most people, there are no risks associated with having an ABI test. This test is not recommended if you have a blood clot in your leg. You might need a different type of test if you have severe pain in your legs.
How do I get ready for an ankle brachial index test?
There is very little you need to do to prepare for an ABI test. You can follow a normal diet on the day of the test. You shouldn’t need to stop taking any medicines before the procedure.
You may want to wear loose, comfortable clothes. This will allow the technician to easily place the blood pressure cuff on your arm and ankle. You’ll need to rest for at least 15 to 30 minutes before the procedure. Ask if your healthcare provider has any special instructions.
What happens during an ankle brachial index test?
The test is very similar to a standard blood pressure test. Ask your healthcare provider about what you can expect. In general, during your ABI test:
- You will lie flat during the procedure.
- A technician will place a blood pressure cuff just above your ankle.
- The technician will place an ultrasound probe over the artery. He or she will use this to listen to the blood flow through the vessel.
- The technician will inflate the blood pressure cuff. He or she will increase the pressure until the blood stops flowing through the vessel. This may be a little uncomfortable, but it won’t hurt.
- The technician will slowly release the pressure in the cuff. The systolic pressure is the pressure at which the blood flow is heard again. That is the part of the blood pressure measurement needed for the ABI.
- The technician will repeat this process on your other ankle and on both of your arms.
- Next, the technician will calculate the ABI. The top number (numerator) is the higher systolic blood pressure found in the ankles. The lower number (denominator) is the higher systolic blood pressure found in the arms.
Sometimes healthcare providers will combine an ABI test with an exercise test. You might have an ABI done before and right after exercise, to see how exercise changes this value.
What happens after an ankle brachial index test?
You should be able to go back to your normal activities right after your ABI test.
Be sure to follow up with your healthcare provider about your results. In some cases, you may need follow-up testing to get more information about a blocked vessel. This might include an MRI or an arteriogram.
If you have PAD, you may need treatment. Possible treatments include:
- Stopping smoking
- Treating high blood pressure, high cholesterol, and diabetes, if needed
- Staying physically active
- Eating a healthy diet
- Taking medicine to increase blood flow to your legs or to prevent blood clots
- Having procedures to restore blood flow, like angioplasty
- Having surgery to your leg (if the blockage is severe)
Talk to your provider about what your ABI value means for you.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure |
After almost a year of suffering and over 250,000 known deaths from this virus in the United States alone, the promise of a vaccine in the near future can feel like a light at the end of what has been a long, dark tunnel. Vaccines have historically lessened the burden of diseases like measles and polio, and there is hope that they will bring an end to the current pandemic (1).
New vaccines to prevent COVID-19 are promising, and feature a number of brand new technologies that might make them more effective and easier to manufacture. However, even if these vaccine candidates are as effective as we hope they are, it will be several months before enough of the population is vaccinated that we can safely return to some semblance of normal life. Until then, the safety of our communities and the stability of our healthcare systems rely on each one of us making healthy choices about hygiene, mask-wearing, and social distancing. Based on how low adherence to public health guidelines has been in the first nine months of the pandemic, that is going to take significant work.
A different type of vaccine, called a “digital vaccine”, might offer a solution to the problem of creating sustained behavioral change. These are not typical vaccinations in the sense of promoting biological immunity to a pathogen, but they have this name because they create resistance to disease through a different mechanism. Digital vaccines are a subtype of digital therapeutics, which use neurocognitive training to promote positive human behavior using technologies like smartphone apps.
A lot of the research into this topic is based out of Carnegie Mellon University, which evaluates digital vaccine candidates through its Digital Vaccine Project. There are several candidates currently being tested, with more under development. One of these that has received the most publicity is ‘Fooya!’, an interactive and immersive gaming platform for children that aims to promote lifestyle changes through video games about healthy eating. The platform applies neuroscience, artificial intelligence, and virtual reality principles, and has been shown to reduce the risk of diabetes, hypertension, and cardiovascular disease in the pediatric population (2).
Some experts believe that digital therapeutics like these might have the potential to change the trajectory of the COVID-19 pandemic. These customized digital vaccines could use neurocognitive training techniques to improve literacy about preventative measures like mask-wearing and social distancing. Importantly, these digital vaccines can be personalized to ensure that the content is culturally-appropriate and relevant to the target audience (3). This could have particularly important applications in countries around the world where biological vaccine distribution will likely not happen as promptly as it will in the United States. It still remains to be seen if these technologies will be successful in improving COVID-19 public health outcomes. But if they are, they could be key in the response to emerging infectious diseases in the future.
Achievements in Public Health, 1900-1999 Impact of Vaccines Universally Recommended for Children -- United States, 1990-1998. https://www.cdc.gov/mmwr/preview/mmwrhtml/00056803.htm
- Digital Vaccine Project, Carnegie Mellon University. https://www.cmu.edu/heinz/digital-vaccine-project/science/index.html
- Battling COVID-19 with ‘digital vaccines’. https://www.medicaleconomics.com/view/battling-covid-19-with-digital-vaccines |
Imagine a bionic arm that plugs directly into the nervous system, so that the brain can control its motion, and the owner can feel pressure and heat through their robotic hand. This prospect has come a step closer with the development of photonic sensors that could improve connections between nerves and prosthetic limbs.
Existing neural interfaces are electronic, using metal components that may be rejected by the body. Now Marc Christensen at Southern Methodist University in Dallas, Texas, and colleagues are building sensors to pick up nerve signals using light instead. They employ optical fibres and polymers that are less likely than metal to trigger an immune response, and which will not corrode.
The sensors are currently in the prototype stage and too big to put in the body, but smaller versions should work in biological tissue, according to the team.
The sensors are based on spherical shells of a polymer that changes shape in an electric field. The shells are coupled with an optical fibre, which sends a beam of light travelling around inside them.
The way that the light travels around the inside of the sphere is called a “whispering gallery mode”, named after the Whispering Gallery in St Paul’s Cathedral, London, where sound travels further than usual because it reflects along a concave wall.
The idea is that the electric field associated with a nerve impulse could affect the shape of the sphere, which will in turn change the resonance of the light on the inside of the shell; the nerve effectively becomes part of a photonic circuit. In theory, the change in resonance of the light travelling through the optical fibre could tell a robotic arm that the brain wants to move a finger, for instance.
Signals could be carried in the other direction by shining infrared light directly onto a nerve – this is known to stimulate nerves – guided by a reflector at the tip of the optical fibre.
To use working versions of the sensors, nerve connections would need to be mapped. For example, a patient could be asked to try to raise their missing arm, so that a surgeon could connect the relevant nerve to the prosthesis.
From New Scientist |
Biomechanics is the term used to describe movement of the body. This section is a review of basic spine biomechanics. In order to better understand the biomechanics of the spine it is important to understand the anatomy of the spine. Please read the section on basic spine anatomy before reading this section. It discusses the bones, ligaments, muscles and other structures that make up and support the spine.
The spine is one of the most complex parts of the body. The spine can be divided into five sections: the cervical section (the neck), the thoracic section (the upper back), the lumbar section (the lower back), the sacrum (part of the pelvis) and the coccyx (the tailbone). Each section of the spine has unique features that allow it to move certain ways and do different things.
The Lumbar Spine
Vertebrae in the cervical, thoracic and lumbar sections of the spine are separated by a structure called the “intervertebral disc”. This disc forms part of the joint that connects the “bodies” of two vertebrae. This joint allows very little movement between two vertebrae. The facets are paired, flat areas of the vertebrae that form joints (facet joints) with the facets of the vertebrae above and below (see diagram). The majority of spine movement occurs at these joints.
The main movements of the spine are to bend forward (flex), bend backward (extend), side-bend (side-flex), and rotate.
In the cervical section of the spine there are 7 “cervical” vertebrae. The joints between the vertebrae in the upper part of the neck (above the second cervical vertebra) allow primarily neck flexion, extension and rotation. The joints between the vertebrae in the lower part of the neck allow flexion, extension, side-flexion and rotation to occur.
In the thoracic section of the spine there are 12 “thoracic” vertebrae. The joints between the vertebrae in the thoracic section of the spine allow flexion, extension, side-flexion and rotation to occur. In the thoracic spine the individual ribs attach to the vertebrae. The ribs provide stability to the thoracic spine and help to control motion.
In the lumbar section of the spine there are 5 “lumbar” vertebrae. The joints between the vertebrae in the lumbar section of the spine allow small amounts of flexion, extension, side-flexion and rotation to occur. The lumbar spine has the least amount of movement when compared to the thoracic and cervical sections of the spine.
The sacrum is a single bone that forms part of the pelvis. This triangular shaped bone is made up of 5 fused vertebrae. The coccyx is also a single bone that is made up of 4 small fused vertebrae. It attaches to the bottom of the sacrum.
There is no movement between the fused vertebrae in the sacrum but there is a small amount of movement in the joints that connect the sacrum to the left and right pelvic bones. These joints are called the sacroiliac joints. The sacroiliac joints play a role in transferring the weight of the spine and upper body to the pelvis and legs.
Finally, normal spine biomechanics is required to maintain a healthy spine. Abnormal biomechanics can be classified as hypomobile (decreased) movement between vertebrae, hypermobile (increased) movement between vertebrae or instability (severe loss of stability). Muscle weakness, ligament injury, broken bones or damage to the intervertebral disc can all lead to abnormal biomechanics, a major factor in the development of neck and back pain. |
Syntax is the branch of linguistics, which studies the rules and standards of the formation of word combinations and sentences. Moreover, the study touches upon other questions related with the structure of the sentence and its components. Syntax studies the connection of words in word combinations and sentences; researches the types of syntactic rules; defines the types of word combinations and sentences; defines the meaning of word combinations and sentences; connection of the simple sentences into the complex ones; defines and studies the parts of the sentence. The linguists started to think about the problems of syntax not so long ago, in the end of the 17th century. From the 19th century syntax started to be investigated more thoroughly. At that time started the development of historical-comparative linguistics, which influenced syntax greatly.
The main idea of historical-comparative linguistics is to compare and study the differences and similarities between the various languages of the world in their historical context. Evidently, syntax of different languages is different and some parts of the sentence which are extremely important in one language do not play any role in the other. On the basis of these syntactic relations the languages are divided into the certain groups. For example, in one language the word order in fluent, in the other is strict; in one language there are seven parts of speech, in the other only four.
As a result it is natural that syntax is a complicated branch, which tries to answer a great number of questions which are connected with the traditional structure of the sentence which is based on ethnical, psychological and other factors.
When a student is asked to prepare a syntax term paper, he is expected to work out vast literary sources in order to find the valid up-to-date facts about this branch of linguistics. One will have to explain the meaning of syntax, present the structure and the core components of syntax, main theories, methods of analysis, historical background of syntax, etc. Furthermore, a student should define the importance of syntax for linguistics and find connections of syntax with other branches of the science. In the end one should summarize the paper and dwell on the strong and weak sides of syntax and try to present the solution to its controversial problems.
The most effective way to prepare a good term paper is to take advantage of the web and look through one the good free example term papers on syntax written by an expert online. With the proper assistance of a free sample term paper on syntax a student can learn everything about the analysis and composition of the text and the correct formatting of the paper. |
A severe respiratory illness caused by a coronavirus (SARS-CoV) and characterized by a variety of signs and symptoms including: fever; chills and rigors; headache, malaise, and myalgias; shortness of breath; cough or other lower respiratory tract symptoms; and in some cases progressive pneumonia and adult respiratory distress syndrome (ARDS).
a respiratory disease of unknown etiology that apparently originated in mainland China in 2003; characterized by fever and coughing or difficulty breathing or hypoxia; can be fatal
Severe Acute Respiratory Syndrome. a potentially deadly respiratory illness caused by a coronavirus. It has recently been reported in Asia, North America and Europe. SARS may be spread by touching the skin of other people or objects that are contaminated with infectious droplets and then touching your eye(s), nose or mouth. It also is possible that SARS can be spread through the air or in other ways that are currently not known. /P Unlike the common cold, SARS symptoms generally begin with a fever greater than 100.4øF. Other symptoms may include headache, an overall feeling of discomfort and body aches. Some people also experience mild respiratory symptoms. After two to seven days, SARS patients may develop a dry cough and have trouble breathing. |
3-D Forest Animals
Populate an entire forest with three-dimensional animals.
Use these 3-D animals to create a diorama for a book report or storytelling time.
Make 3-D stand-up animals to accompany a report, story time or a project including forest animals.
Supplies Used: Adhesive, Cardstock or construction paper, Crayons, markers or pens, Pencil, Scissors, Tape
The teacher will die-cut the materials for student use prior to the lesson.
- Die-cut any of the 3-D animals from cardstock or construction paper.
- Add details with crayons, markers or pens on both sides of the die-cut animals (Figure A).
- Align the front and back of the animal bodies, and fold at the top so that all four feet touch the table top at the same time.
- Fold both tabs in toward the middle, and slide the slits on the tabs together (Figure B). This will allow the animals to stand (Figure C).
Create the forest
- Die-cut three of the Tree or Tree, Bare shapes, two from cardstock or construction paper and one from copy paper.
- Fold the copy paper Tree in half and make a mark at the midpoint of the Tree.
- Place the folded copy paper tree on one construction paper Tree, and draw a line from the midpoint mark up to the top of the Tree (Figure D).
- Cut along the pencil line. Cut a thin sliver right next to the slit to make a slightly wider opening. This will facilitate in sliding the two Trees together.
- Place the folded copy paper Tree on the other construction paper Tree, and draw a line from the midpoint mark down to the bottom of the Tree.
- Cut along the pencil line. Cut a thin sliver right next to the slit to make a slightly wider opening.
- Interlock the slits to allow the Tree to stand.
- Add some dimensional Trees to these 3-D forest animals for a project that is tree-mendous (Main Photo).
- Discuss other animals found in forests and their habitat.
- Figure A
- Figure B
- Figure C
- Figure D
Fine Arts-Visual Arts
NA-VA.K-4.2 Using Knowledge of Structures and Functions
- Students use visual structures and functions of art to communicate ideas
NA-VA.K-4.6 Making Connections Between Visual Arts and Other Disciplines
- Students identify connections between the visual arts and other disciplines in the curriculum
NL-ENG.K-12-4 Communication Skills
- Students adjust their use of spoken, written and visual language (e.g., conventions, style, vocabulary) to communicate effectively with a variety of audiences and for different purposes
NK.K-4.3 Life Science
As a result of activities in grades K–4, all students should develop understanding of
- Organisms and environments |
The bloodstream is crucial to the body. The blood travels around the body, delivering oxygen to the various areas of the body.
The actual delivery is completed by the red blood cells that are located within the blood. People with anemia are not transferring enough oxygen to the outer parts of the body. There are several different types of anemia. Sometimes red blood cells stop being produced. Sometimes they are deficient in some way and don’t carry oxygen. Anemia can also range from milk to moderate in severity. Symptoms of anemia are pretty common. The lack of oxygen often shows itself in fatigue, weakness, shortness of breath, dizziness and headaches. Some people get irregular heartbeats, have their skin turn yellow or go pale, suffer from chest pain or have cold hands and feet. Take this opportunity to learn more about the different types of anemia and how they affect the body.
1 - Iron Deficiency Anemia
This is one of the more common types of anemia. People with this type of anemia quite simply aren’t getting or processing enough iron in their body. Iron is one of the requirements for producing red blood cells in the bone marrow. Specifically it doesn’t produce the hemoglobin aspect of the red blood cells. Typically, iron deficiency anemia is treated through supplements. Sometimes, people may choose to alter their diet to increase the amount of iron they are taking in as well. There are high levels of iron in beans, seafood, red meat, chicken, spinach and dried fruit. Pregnant women can suffer from iron deficiency anemia as well since they are providing red blood cells for the baby in addition to themselves.
2 - Sickle Cell Anemia
This form of anemia is one that is passed down genetically. People with sickle cell anemia produce blood cells, but they are not functional. This is because many of the red blood cells don’t take the normal circular shape. Sickle cell anemia causes the red blood cells to form as crescent moons or like sickles (thus the name). People with sickle cell anemia often suffer from large amounts of pain among their symptoms. Medication is important to helping handle the pain and prevent some of the complications of sickle cell anemia. Blood transfusions can also be required at times to ensure the body has enough blood to properly manage.
3 - Aplastic Anemia
People who suffer from aplastic anemia struggle with production of red blood cells. Unlike many other forms of anemia which are obvious at birth, this is a condition that can happen at any stage in life. What’s more interesting is it can begin severe or it can start gently and degenerate. People who have aplastic anemia have to seek treatment. Medication is a starter treatment with blood transfusions and bone marrow transplants becoming treatment options for more serious cases.
4 - Thalassemia
Thalassemia is an inherited disorder. The bloodstream doesn’t carry as much hemoglobin as it’s supposed to. Severe fatigue and weakness in the body is rather common. Mild cases can sometimes avoid treatment. In these cases, symptoms are light or don’t exist. More serious often require fairly frequent blood transfusions. Treatment also needs to include chelation therapy. This is a procedure to get rid of the excessive iron that can build up due to those blood transfusions.
5 - Vitamin Deficiency Anemia
Symptoms of vitamin deficiency anemia are similar to those of the other forms. The cause is right there in the name. People don’t have enough specific vitamins in their diet and body. The vitamins in question are vitamin C, vitamin V-12 and folate. Diets should be altered to include more of these vitamins. Sometimes the body can’t properly absorb enough of these vitamins. The answer is usually again, more vitamins in the diet or through supplements. |
Overview Of Down SyndromeDown syndrome is a genetic disorder that affects 1 in every 800 births in North America. Down syndrome is the most common genetic conditions whose symptoms are present right at birth, and the most prominent cause of cognitive disability. The disorder was first recognized in mid-19th century when a physician named Down noticed the resemblance of physical and mental anomalies that run in families. About 100 years later Jacobs and Lejeune identified the genetic components that make up Down syndrome and described the chromosomal characteristics of persons affected by the condition.
Down Syndrome And Bone DevelopmentDown syndrome is characterized by a number of different symptoms, some that define the physical appearance of the patient and others that determine the mental capabilities. When it comes to the physical growth and bone development, individuals affected by the syndrome grow at a much slower pace than average persons from the general population. Developmental milestones are reached at different times, while the full capacity of a Down syndrome person remains limited compared to non Down syndrome peers. For instance, affected persons are short in stature and often develop obesity sometime during puberty. The skull is never fully formed and its development is coupled by various barriers. Sloping foreheads, sinus defects, microcephaly, brachycephalic, and similar characteristics distinguish the skulls. The mouth and teeth are also substantially affected. The lips are often very full while the tongue is abnormally long. Down syndrome persons tend to drool and have chapped lips. The teeth are often decaying, as there are larger amounts of saliva in Down syndrome people, which allow the bacteria to deform the teeth. Patients often have small necks and malformed ears. Hearing problems are commonly observed, as the middle ear is disfigured and often full of excess liquid. Numerous vision problems are present as well. More than 50 percent of affected persons will have some form of vision impairment.
Hands And Feet In Down SyndromeHand and feet of Down syndrome individuals are different from those of the non-disabled persons. When it comes to the hands, there is usually only one crease across the palm. Their finders are short and chubby, and the small finger is often turned inward. In the case of feet, they are also small and the space between the big and the next toe is wider than usual. These physical characteristics are of no medical importance other than to help in making diagnoses based on a physical exam when children are born.
Other Developmental ProblemsAside from the physical features, Down syndrome also produces numerous other anomalies. For instance, individuals with the condition often suffer from mild to severe mental retardation sometimes with a much lower than normal IQ. Nevertheless, regardless of how limited their potential may be, these persons should not be compared to children from the general population as their developmental paths are different. Further, Down syndrome persons are capable of learning new things, acquiring skills, and accumulating knowledge throughout their lives. It is important that the parents and caregivers provide the right educational opportunities and their Down syndrome child could grow up being an independent adult. When it comes to the behavior of such persons they are highly capable to interpreting emotions and are generally genuine, patient, spontaneous, and tolerable. It should be noted that the spectrum of personality traits among Down syndrome individuals is just as wide as it is among the general public. In addition to the cognitive issues, sleep problems are often observed as well. Sleep apnea due to deformed sinuses is one of the most commonly seen ones, and so is insomnia. Seizures are also sometimes reported. Different forms of epileptic fits are seen in children and adults. Lastly, persons suffering from the condition are known to age prematurely. Their hair will gray and eyes will develop cataracts In some cases they’ll develop dementia or Alzheimer’s disease.
Causes of Down SyndromeIt is known that the condition is genetic, and the pattern of inheritance is fairly clear. The chromosomal differences have been identified and explained but the root causes of the disorders are still unknown. Individuals with Down syndrome inherit extra genetic material at conception. Persons who develop normally have 46 chromosomes, 23 from the mother, and 23 from the father. Down syndrome people inherit one additional chromosome 21 or some of its genetic material, totaling 47 chromosomes. The additional genetic material affects almost every part of the body and leads to a wide array of problems. As is the case with any other genetic condition, the parents do not have to have any symptoms themselves, they just need to be the carriers of the disorder. As there are rarely any signs of the malfunctioning genes in the carriers they are usually unaware of the fact that they could pass on defective genetic material to their offspring. |
On September 21, we celebrate World Alzheimer’s Day to raise awareness of the impact of Alzheimer’s Disease and other forms of dementia on loved ones afflicted and on family members and friends impacted by their diagnoses. Have you heard that Alzheimer’s disease has been called the “family” disease because of the difficult impacts it can have on the afflicted person’s family members and friends? Often, those family members and friends include children. By helping kids through this process and encouraging them to continue interacting with a loved one diagnosed with the disease, you can help foster empathy and compassion while bringing joy to all impacted.
There are many ways to promote understanding of Alzheimer’s Disease with young children. It can be important to help ensure that young kids understand that Alzheimer’s and other forms of dementia are diseases that tend to occur in life as people get older. Explain that kids cannot spread the disease and are unlikely to contract the disease themselves. If kids know that they cannot “catch” Alzheimer’s they may be less likely to be afraid of spending time with the diagnosed loved one, and less concerned that they might have done something to cause the disease.
Kids may have questions that they are reluctant to ask Mom or Dad. If that is the case, get in touch with a school counselor or ask their pediatrician for a recommendation. Giving your kids an outlet where they can go to voice their fears without concern for Mom and Dad’s feelings may increase their sense of control in their own lives, and help ensure things do not stay bottled up.
Spending time with young children often brings joy to a family member affected by Alzheimer’s, even if they no longer recognize their familial relationship with these children, who may be their grandchildren, nieces, or nephews. Bring your kids to spend an afternoon with their grandparent or other loved one and encourage them to simply play and engage in regular activities like arts and crafts. Your loved one with Alzheimer’s may even want to join them in doing a craft or a puzzle. Just make sure to explain to your kids that their loved one may get frustrated easily, and it can be okay if you or another caregiver gently ends the activity if it becomes overwhelming.
For more guidance on helping a loved one with Alzheimer’s as well as impacted family members, please reach out to our office. |
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Ultra FineWeb EDU
High-Quality Educational Content from Ultra-FineWeb
Filtered for Maximum Educational Value
📚 Overview
Ultra FineWeb EDU is a premium educational dataset created by applying advanced educational content filtering to the exceptional Ultra-FineWeb dataset. This work builds directly upon two foundational achievements: the rigorous data curation methodology of Ultra-FineWeb and the sophisticated educational classification capabilities of the FineWeb-Edu classifier. We extract only the highest quality educational content with a strict threshold of 3.5+ educational score.
⭐ Key Features
- 🎯 Premium Quality: Only content scoring 3.5+ on educational value (top ~10% of Ultra-FineWeb)
- 📖 Pure Content: Metadata stripped, contains only the essential text content
- 🔍 Rigorous Filtering: Multi-stage filtering pipeline ensures exceptional quality
- ⚡ Optimized Processing: High-performance GPU-accelerated filtering pipeline
- 🤝 Community Driven: Open-source processing code for reproducibility and extension
📊 Dataset Statistics
Filtering Pipeline Overview
Raw Web Content (Trillions of pages)
↓ (Heavy filtering)
FineWeb (24.99B examples)
↓ (94.83% filtered out)
Ultra-FineWeb (1.29B examples)
↓ (90% filtered out - Educational threshold 3.5+)
Ultra FineWeb EDU (64,000+ examples) ← This Dataset
Quality Metrics
- Educational Threshold: 3.5+ (Excellent educational value)
- Pass Rate: ~10% (highly selective)
- Content Type: Pure text content, metadata removed
- Average Educational Score: 4.2+ (estimated for passed content)
- Language: English (with potential for multilingual expansion)
- Current Release: 64,000+ premium educational samples
🏗️ Creation Methodology
Building on Proven Excellence: This dataset leverages the battle-tested methodologies from Ultra-FineWeb's efficient verification-based filtering and FineWeb-Edu's expert-validated educational classification.
Educational Classification
We used the proven HuggingFace FineWeb-Edu classifier, trained on 450k expert annotations, to score each sample:
- Score 0-1: Not educational / Low educational value → Filtered out
- Score 2-3: Some to good educational value → Filtered out
- Score 3.5+: High to excellent educational value → ✅ Included
Processing Pipeline
- Stream Ultra-FineWeb in batches for memory efficiency
- Extract content field only (remove metadata)
- Educational scoring using BERT-based classifier
- Threshold filtering at 3.5+ educational score
- Quality validation and dataset compilation
🚀 Performance Optimizations
Our processing pipeline achieves 350+ samples/second using:
- ⚡ FP16 precision for 2x speed boost
- 🔥 Large batch processing (512+ samples)
- 🎯 GPU memory optimization
- 💾 Automatic checkpointing every 30 minutes
- 🔄 Smart memory management and cleanup
📁 Dataset Structure
{
"content": "High-quality educational text content..."
}
Each sample contains only the content field with educational text, optimized for training language models focused on educational applications.
🛠️ Processing Code
The complete processing pipeline is open-sourced to enable community scaling and reproduction. The code includes optimizations for high-speed GPU processing, automatic checkpointing, and educational quality filtering.
Requirements
pip install torch transformers datasets tqdm numpy pandas
Complete processing script and documentation will be available in the repository.
📈 Quality Analysis
Educational Score Distribution (Based on 64,000+ Samples)
- Score 3.5-4.0: Solid educational content (60% of passed samples)
- Score 4.0-4.5: High-quality educational material (30% of passed samples)
- Score 4.5-5.0: Exceptional educational resources (10% of passed samples)
🎯 Use Cases
- Educational AI Training: Train models specifically for educational applications
- Content Quality Research: Study high-quality web content characteristics
- Educational Content Generation: Fine-tune models for creating educational materials
- Knowledge Distillation: Transfer educational knowledge to smaller models
- Curriculum Development: Analyze educational content patterns and structures
🤝 Community & Contributions
This initial release of 64,000+ premium educational samples demonstrates the effectiveness of our filtering pipeline. The dataset represents a proof-of-concept for community-driven scaling.
How you can contribute:
- Scale the processing: Use our code to process additional Ultra-FineWeb data
- Quality improvements: Suggest enhanced filtering techniques
- Multilingual expansion: Apply similar filtering to other languages
- Research applications: Share findings and use cases with the community
Next Steps: The processing pipeline is designed for easy scaling. With access to larger compute resources, the complete Ultra-FineWeb dataset can be processed to yield an estimated 130M+ premium educational samples.
🚀 More Examples Coming Soon
This initial release represents just the beginning! We're actively working to expand Ultra FineWeb EDU with additional high-quality educational content.
📈 Upcoming Releases:
- Extended English Dataset: Processing continues on the full Ultra-FineWeb English corpus
- Multilingual Support: Chinese educational content from Ultra-FineWeb-zh
- Quality Improvements: Enhanced filtering techniques and threshold optimization
- Community Contributions: Datasets processed by community members with larger compute resources
🔄 Release Schedule:
- Phase 1 (Current): 64,000+ samples - Proof of concept ✅
- Phase 2 (Coming Soon): 500,000+ samples - Extended initial release
- Phase 3 (Future): 10M+ samples - Major expansion
- Phase 4 (Goal): 130M+ samples - Complete Ultra-FineWeb processing
📊 Stay Updated: Follow this repository for announcements about new releases, expanded datasets, and community contributions. Each release will maintain the same rigorous 3.5+ educational quality threshold.
Processing speed: ~350 samples/second on consumer hardware. Community members with enterprise GPUs can significantly accelerate timeline.
📄 Citation
If you use Ultra FineWeb EDU in your research or applications, please cite:
@dataset{procreations2025ultrafineweb_edu,
title={Ultra FineWeb EDU: High-Quality Educational Content from Ultra-FineWeb},
author={ProCreations},
year={2025},
url={https://huggingface.co/datasets/[dataset-url]},
note={Filtered from Ultra-FineWeb using educational quality threshold 3.5+}
}
🙏 Acknowledgments
This dataset stands on the shoulders of giants and would not be possible without the groundbreaking work of several teams:
Core Foundations
🏆 Ultra-FineWeb Team (openbmb): For creating the exceptional Ultra-FineWeb dataset through their innovative efficient verification-based filtering pipeline. Their work represents a quantum leap in data quality, reducing 25B samples to 1.3B through rigorous curation. This dataset directly builds upon their outstanding research and methodology. (Ultra-FineWeb, Technical Report)
🧠 FineWeb-Edu Team (HuggingFaceFW): For developing the sophisticated educational content classifier that makes this work possible. Their BERT-based model, trained on 450k expert annotations, provides the critical educational quality assessment that enables precise filtering. (FineWeb-Edu Classifier)
Additional Thanks
- FineWeb Team: For the original high-quality web corpus that serves as the foundation for all subsequent work
- Llama3 Team: For providing the annotations that trained the educational classifier
- Snowflake Arctic Team: For the embedding model that powers the classifier
- Open Source Community: For the tools, libraries, and collaborative spirit that enables this research
Special Recognition
The methodologies, quality standards, and technical innovations developed by the Ultra-FineWeb and FineWeb-Edu teams form the core foundation of this dataset. This work is essentially an application and extension of their remarkable contributions to the field of high-quality dataset curation.
📜 License
This dataset is released under the Apache 2.0 License, consistent with the source Ultra-FineWeb dataset. Please ensure compliance with the original dataset licenses when using this data.
🔗 Related Resources
Created by ProCreations | Powered by Community Collaboration
Building better educational AI, one dataset at a time 🚀📚
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