1.
Trichuris trichiura
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The human whipworm is a round worm that causes trichuriasis when it infects a human large intestine. It is commonly known as the whipworm which refers to the shape of the worm, the female T. trichiura produces 2, 000–10,000 single-celled eggs per day. Eggs are deposited from human feces to soil where, after two to three weeks, they become embryonated and enter the “infective” stage and these embryonated infective eggs are ingested and hatch in the human small intestine exploiting the intestinal microflora as hatching stimulus. This is the location of growth and molting, the infective larvae penetrate the villi and continue to develop in the small intestine. The young worms move to the caecum and penetrate the mucosa, the life cycle from time of ingestion of eggs to development of mature worms takes approximately three months. During this time, there may be limited signs of infection in stool samples due to lack of egg production, the female T. trichiura begin to lay eggs after three months of maturity. Worms can live up to five years, during which females can lay up to 20,000 eggs per day. Trichuris trichiura has a narrow anterior esophageal end and shorter and thicker posterior anus and these pinkish-white worms are threaded through the mucosa. They attach to the host through their anterior end and feed on tissue secretions instead of blood. Females are larger than males, approximately 35–50 mm long compared to 30–45 mm, the females have a bluntly round posterior end compared to their male counterparts with a coiled posterior end. Their characteristic eggs are barrel-shaped and brown, and have bipolar protuberances, infection occurs through ingestion of eggs and is more common in warmer areas. The eggs hatch in the intestine, and then move into the wall of the small intestine. On reaching adulthood, the thinner end burrows into the large intestine, the females can grow to 50 mm long. Neither the male nor the female has much of a visible tail past the anus, whipworm commonly infects patients also infected with Giardia, Entamoeba histolytica, Ascaris lumbricoides, and hookworms. There is a distribution of Trichuris trichiura, with an estimated 1 billion human infections. However, it is tropical, especially in Asia and, to a lesser degree, in Africa. Within the United States, infection is rare overall but may be common in the rural Southeast, poor hygiene is associated with trichuriasis as well as the consumption of shaded moist soil, or food that may have been fecally contaminated. Children are especially vulnerable to due to their high exposure risk
2.
Diagnostic method
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Medical diagnosis is the process of determining which disease or condition explains a persons symptoms and signs. It is most often referred to as diagnosis with the context being implicit. The information required for diagnosis is typically collected from a history, often, one or more diagnostic procedures, such as diagnostic tests, are also done during the process. Sometimes Posthumous diagnosis is considered a kind of medical diagnosis, Diagnosis is often challenging, because many signs and symptoms are nonspecific. For example, redness of the skin, by itself, is a sign of many disorders, thus differential diagnosis, in which several possible explanations are compared and contrasted, must be performed. This involves the correlation of various pieces of information followed by the recognition and differentiation of patterns, occasionally the process is made easy by a sign or symptom that is pathognomonic. Diagnosis is a component of the procedure of a doctors visit. From the point of view of statistics, the procedure involves classification tests. The first recorded examples of medical diagnosis are found in the writings of Imhotep in ancient Egypt, a Babylonian medical textbook, the Diagnostic Handbook written by Esagil-kin-apli, introduced the use of empiricism, logic and rationality in the diagnosis of an illness or disease. Traditional Chinese Medicine, as described in the Yellow Emperors Inner Canon or Huangdi Neijing, specified four diagnostic methods, inspection, auscultation-olfaction, interrogation, hippocrates was known to make diagnoses by tasting his patients urine and smelling their sweat. This article uses diagnostician as any of these person categories, a diagnostic procedure does not necessarily involve elucidation of the etiology of the diseases or conditions of interest, that is, what caused the disease or condition. Such elucidation can be useful to optimize treatment, further specify the prognosis or prevent recurrence of the disease or condition in the future, the initial task is to detect a medical indication to perform a diagnostic procedure. Indications include, Detection of any deviation from what is known to be normal, such as can be described in terms of, for example, anatomy, physiology, pathology, psychology, a complaint expressed by a patient. The fact that a patient has sought a diagnostician can itself be an indication to perform a diagnostic procedure, even during an already ongoing diagnostic procedure, there can be an indication to perform another, separate, diagnostic procedure for another, potentially concomitant, disease or condition. A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease, Diagnostic tests can also be used to provide prognostic information on people with established disease. Processing of the answers, findings or other results, consultations with other providers and specialists in the field may be sought. There are a number of methods or techniques that can be used in a diagnostic procedure, in reality, a diagnostic procedure may involve components of multiple methods. The final result may also remain a list of possible conditions, the resultant diagnostic opinion by this method can be regarded more or less as a diagnosis of exclusion
3.
Parasitic worm
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Helminths, also commonly known as parasitic worms, are large multicellular organisms, which when mature can generally be seen with the naked eye. They are often referred to as intestinal worms even though not all helminths reside in the intestines, for example schistosomes are not intestinal worms, but rather reside in blood vessels. There is no consensus on the taxonomy of helminths, it is more of a commonly used term to describe certain worms with superficial similarities. Many, but not all, of the referred to as helminths belong to the group of intestinal parasites. An infection by a helminth is known as helminthiasis, soil-transmitted helminthiasis, helminths are worm-like organisms living in and feeding on living hosts, receiving nourishment and protection while disrupting their hosts nutrient absorption, causing weakness and disease. Those that live inside the digestive tract are called intestinal parasites and they can live inside humans and other animals. In their adult form, helminths cannot multiply in humans, helminths are able to survive in their mammalian hosts for many years due to their ability to manipulate the immune response by secreting immunomodulatory products. Helminth ova have a shell that protects the eggs against a range of environmental conditions. Helminthology is the study of worms and their effects on their hosts. The word helminth comes from Greek hélmins, a kind of worm, there is no real consensus on the taxonomy of the helminths, particularly with the nematodes. The term helminth contains a number of phyla, many of which are completely unrelated, however, for practical considerations the term is still used nowadays to describe four groups with superficial similarities, the phyla Annelida, Platyhelminths, Nematoda and Acanthocephala. There is in fact no helminth classification, it is an artificial term, the latter are further divided into cestodes and trematodes depending on whether or not they have a segmented body. Ringworm is actually caused by fungi and not by a parasitic worm. Helminths are a group of unrelated organisms which share a similar form. Helminths include members of the taxa, monogeneans, cestodes, nematodes. The number of different helminth species is vast, it is estimated to be one million species. The nematodes are the most diverse of all the helminths with the highest number of species, there may be as many as 300,000 species of parasites affecting vertebrates, and as many as 300 affecting humans alone. Characteristics that are common for all include, Life time
4.
Blood
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Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. In vertebrates, it is composed of blood cells suspended in blood plasma, plasma, which constitutes 55% of blood fluid, is mostly water, and contains dissipated proteins, glucose, mineral ions, hormones, carbon dioxide, and blood cells themselves. Albumin is the protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are red blood cells, white blood cells. The most abundant cells in blood are red blood cells. These contain hemoglobin, a protein, which facilitates oxygen transport by reversibly binding to this respiratory gas. In contrast, carbon dioxide is mostly transported extracellularly as bicarbonate ion transported in plasma, vertebrate blood is bright red when its hemoglobin is oxygenated and dark red when it is deoxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, insects and some mollusks use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this blood does not contain oxygen-carrying molecules such as hemoglobin because their bodies are small enough for their system to suffice for supplying oxygen. Jawed vertebrates have an immune system, based largely on white blood cells. White blood cells help to resist infections and parasites, platelets are important in the clotting of blood. Arthropods, using hemolymph, have hemocytes as part of their immune system, Blood is circulated around the body through blood vessels by the pumping action of the heart. Medical terms related to blood often begin with hemo- or hemato- from the Greek word αἷμα for blood. In terms of anatomy and histology, blood is considered a form of connective tissue, given its origin in the bones. The average adult has a volume of roughly 5 litres. These blood cells consist of erythrocytes, leukocytes, and thrombocytes, by volume, the red blood cells constitute about 45% of whole blood, the plasma about 54. 3%, and white cells about 0. 7%. Whole blood exhibits non-Newtonian fluid dynamics, if all human hemoglobin were free in the plasma rather than being contained in RBCs, the circulatory fluid would be too viscous for the cardiovascular system to function effectively. One microliter of blood contains,4.7 to 6.1 million,4.2 to 5.4 million erythrocytes, Red blood cells contain the bloods hemoglobin, mature red blood cells lack a nucleus and organelles in mammals
5.
Open defecation
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Open defecation is the practice of people defecating outside and not into a designated toilet. The term is used in literature about water, sanitation. Open defecation causes public health problems in areas where people defecate in fields, urban parks, rivers, eliminating open defecation is the main aim of improving access to sanitation worldwide and is a proposed indicator for sustainable development goals. Even if toilets are available, people still need to be convinced to refrain from open defecation, therefore, the need for behavioural change is critical in addition to the provision of toilets. A preference for open defecation may be due to cultural practices or lack of access to toilets. Extreme poverty and lack of sanitation are statistically linked, eliminating open defecation is said to be an important part of development efforts. About one billion people, or 15 percent of the global population, India has the highest number of people practicing open defecation, around 490 million people, or nearly a third of the population. Most of it occurs in areas, where the prevalence is estimated at 52 percent of the population, as opposed to urban areas. The other countries with the highest number of people openly defecating are Indonesia, followed by Pakistan, Nigeria, Ethiopia, open defecation perpetuates the vicious cycle of disease and poverty and is widely regarded as an affront to personal dignity. The JMP is a joint program by WHO and UNICEF to monitor the water, for monitoring purposes, two categories were created, improved sanitation and unimproved sanitation. Open defecation falls into the latter category and this means that people practicing open defecation are counted having no access to improved sanitation. In 2013 World Toilet Day was celebrated as an official UN day for the first time, open defecation free is a phrase first used in community-led total sanitation programs and has now entered use in other contexts. The original meaning was simply that all community members are using sanitation systems rather than practising open defecation, further more stringent criteria have been added in some countries where CLTS programs exist. This definition is part of the Swachh Bharat Abhiyan, in developing countries however, the situation is entirely different. Here, open defecation is a practice associated with poverty and exclusion particularly when it comes to less remote and less rural areas. The Joint Monitoring Programme for Water Supply and Sanitation of UNICEF, the figures are segregated by rural and urban areas and by wealth quintiles. This program is tasked to monitor progress towards the millennium development goal relating to drinking water, as open defecation is one example of unimproved sanitation, it is being monitored by JMP for each country and results published on a regular basis. The figures on open defecation used to be lumped together with figures on unimproved sanitation but are collected separately since 2010
6.
Feces
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Feces or faeces are the solid or semisolid metabolic waste from an animals digestive tract, discharged through the anus or cloaca during a process called defecation. Urine and feces together are called excreta, collected feces has various uses, namely as fertilizer or soil conditioner in agriculture, as a fuel source, or for medicinal purposes. After an animal has digested eaten material, the remains of material are discharged from its body as waste. Although it is lower in energy than the food from which it is derived, feces may retain a large amount of energy and this means that of all food eaten, a significant amount of energy remains for the decomposers of ecosystems. Many organisms feed on feces, from bacteria to fungi to insects such as dung beetles, some may specialize in feces, while others may eat other foods as well. Feces serve not only as a food, but also as a supplement to the usual diet of some animals. Feces and urine, which reflect light, are important to raptors such as kestrels. Seeds also may be found in feces, animals who eat fruit are known as frugivores. An advantage for a plant in having fruit is that animals will eat the fruit and this mode of seed dispersal is highly successful, as seeds dispersed around the base of a plant are unlikely to succeed and often are subject to heavy predation. Provided the seed can withstand the pathway through the system, it is not only likely to be far away from the parent plant. This cycling of matter is known as the biogeochemical cycle, the distinctive odor of feces is due to bacterial action. Gut flora produce compounds such as indole, skatole, and thiols and these are the same compounds that are responsible for the odor of flatulence. Consumption of foods prepared with spices may result in the spices being undigested, the perceived bad odor of feces has been hypothesized to be a deterrent for humans, as consuming or touching it may result in sickness or infection. Human perception of the odor may be contrasted by an animals perception of it, for example. In humans and depending on the individual and the circumstances, defecation may occur daily, extensive hardening of the feces may cause prolonged interruption in the routine and is called constipation. Human fecal matter varies significantly in appearance, depending on diet, normally it is semisolid, with a mucus coating. The brown coloration comes from a combination of bile and bilirubin, in newborn babies, initially fecal matter is yellow-green after the meconium. This coloration comes from the presence of bile alone, throughout the life of an ordinary human, one may experience many types of feces
7.
Fertilizer
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A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants. Fertilizers enhance the growth of plants and this goal is met in two ways, the traditional one being additives that provide nutrients. The second mode by which some fertilizers act is to enhance the effectiveness of the soil by modifying its water retention and aeration and this article, like many on fertilizers, emphasises the nutritional aspect. The nutrients required for plant life are classified according to the elements. Instead compounds containing these elements are the basis of fertilizers, the macronutrients are consumed in larger quantities and are present in plant tissue in quantities from 0. 15% to 6. 0% on a dry matter basis. Plants are made up of four elements, hydrogen, oxygen, carbon. Carbon, hydrogen and oxygen are widely available as water and carbon dioxide, although nitrogen makes up most of the atmosphere, it is in a form that is unavailable to plants. Nitrogen is the most important fertilizer since nitrogen is present in proteins, DNA, to be nutritious to plants, nitrogen must be made available in a fixed form. Only some bacteria and their host plants can fix atmospheric nitrogen by converting it to ammonia, phosphate is required for the production of DNA and ATP, the main energy carrier in cells, as well as certain lipids. Micronutrients are consumed in quantities and are present in plant tissue on the order of parts-per-million, ranging from 0.15 to 400 ppm DM. These elements are present at the active sites of enzymes that carry out the plants metabolism. Because these elements enable catalysts their impact far exceeds their weight percentage, Fertilizers are classified in several ways. They are classified according to whether they provide a single nutrient, multinutrient fertilizers provide two or more nutrients, for example N and P. Fertilizers are also sometimes classified as inorganic versus organic. Inorganic fertilizers exclude carbon-containing materials except ureas, organic fertilizers are usually plant- or animal-derived matter. Inorganic are sometimes called synthetic fertilizers since various chemical treatments are required for their manufacture, the main nitrogen-based straight fertilizer is ammonia or its solutions. Ammonium nitrate is widely used. Urea is another source of nitrogen, having the advantage that it is solid and non-explosive, unlike ammonia and ammonium nitrate. A few percent of the fertilizer market has been met by calcium ammonium nitrate
8.
Large bowel
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The large intestine, or the large bowel, is the last part of the gastrointestinal tract and of the digestive system in vertebrates. Water is absorbed here and the waste material is stored as feces before being removed by defecation. Most sources define the large intestine as the combination of the cecum, colon, rectum, some other sources exclude the anal canal. In humans, the large intestine begins in the right region of the pelvis, just at or below the waist. It then continues as the colon ascending the abdomen, across the width of the cavity as the transverse colon. Overall, in humans, the intestine is about 1.5 metres long. The colon is the last part of the digestive system and it extracts water and salt from solid wastes before they are eliminated from the body and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a role in absorption of foods. About 1.5 litres or 45 ounces of water arrives in the each day. The length of the human male colon is 166 cm, on average. In mammals, the colon consists of five sections, the cecum plus the colon, the transverse colon, the descending colon, the sigmoid colon. Retroperitoneal organs in general do not have a covering of peritoneum. Intraperitoneal organs are completely surrounded by peritoneum and are therefore mobile, of the colon, the ascending colon, descending colon and rectum are retroperitoneal, while the cecum, appendix, transverse colon and sigmoid colon are intraperitoneal. This is important as it affects which organs can be accessed during surgery. The ascending colon is the first of four sections of the large intestine and it is connected to the small intestine by a section of bowel called the cecum. The ascending colon runs upwards through the abdominal cavity toward the transverse colon for approximately eight inches, one of the main functions of the colon is to remove the water and other key nutrients from waste material and recycle it. As the waste material exits the small intestine through the valve, it will move into the cecum. The unwanted waste material is moved upwards toward the transverse colon by the action of peristalsis, the ascending colon is sometimes attached to the appendix via Gerlachs valve
9.
Microscope
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A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy, microscopic means invisible to the eye unless aided by a microscope. There are many types of microscopes, the most common is the optical microscope, which uses light to image the sample. Other major types of microscopes are the microscope, the ultramicroscope. The earliest microscopes were single lens magnifying glasses with limited magnification which date at least as far back as the wide use of lenses in eyeglasses in the 13th century. Compound microscopes, which combine an objective lens with an eyepiece to view a real image, the actual inventor of the compound microscope is unknown although many claims have been made over the years. These include what may be a claim by the son of Zacharias Janssen that his father invented the microscope and telescope as early as 1590. Historians note the compound microscope did not appear in the Netherlands until the 1620s, giovanni Faber coined the name microscope for the compound microscope Galileo submitted to the Accademia dei Lincei in 1625. The first detailed account of the construction of living tissue based on the use of a microscope did not appear until 1644, in Giambattista Odiernas Locchio della mosca. It was not until the 1660s and 1670s that the microscope was used extensively for research in Italy, marcello Malpighi in Italy began the analysis of biological structures, beginning with the lungs. Robert Hookes Micrographia had an impact, largely because of its impressive illustrations. A significant contribution came from Antonie van Leeuwenhoek who achieved up to 300 times magnification using a single lens microscope. He sandwiched a very small glass ball lens between the holes in two metal plates riveted together, and with a needle attached to mount the specimen. Then, Van Leeuwenhoek re-discovered red blood cells and spermatozoa, on 9 October 1676, he reported the discovery of micro-organisms. The performance of light microscopy depends as much on how the sample is illuminated as on how it is observed, early instruments were limited until this principle was fully appreciated and developed, and until electric lamps were available as light sources. In 1893 August Köhler developed a key principle of sample illumination, Köhler illumination and this method of sample illumination produces even lighting and overcomes the limited contrast and resolution imposed by early techniques of sample illumination. In the early 20th century a significant alternative to light microscopy was developed, ernst Ruska started development of the first electron microscope in 1931 which was the transmission electron microscope. The transmission electron microscope works on the principle as an optical microscope but uses electrons in the place of light
10.
Soil-transmitted helminthiasis
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Soil-transmitted helminthiasis is a type of helminth infection caused by different species of roundworms. It is caused specifically by those worms which are transmitted through soil contaminated with faecal matter and are therefore called soil-transmitted helminths, three types of soil-transmitted helminthiasis can be distinguished, ascariasis, hookworm infection and whipworm infection. It has become the most common disease of humans worldwide. Approximately two billion people are infected as of the latest estimate, and four billion at risk, surpassing even the all-time most prevalent parasitic disease, the largest numbers of cases occur in impoverished rural areas of Sub-Saharan Africa, Latin America, Southeast Asia, and China. Its main cause, like for many types of infections, is lack of sanitation, such as the practice of open defecation. It is regarded as one of the worlds most important causes of intellectual and physical retardation, the helminthic disease is so named because the infection is transmitted through ingestion of the nematode eggs in the soil, which is contaminated through excrements. Therefore, the disease is most prevalent in warm and moist climates where sanitation and hygiene are poor and waters are unsafe and it is now among the target diseases of London Declaration on Neglected Tropical Diseases to be controlled/eradicated by 2020. Simple prevention and control strategies are access to improved sanitation, public awareness on personal hygiene, symptoms becomes evident only when the intensity of infection is relatively high. Thus the degree of negative outcomes is directly related to worm burden, most conditions of STH have a light worm burden and usually have no discernible symptoms. Heavy infections however cause a range of problems, including abdominal pain, diarrhoea, blood and protein loss, rectal prolapse. Severe ascariasis is typically a pneumonia, as the larvae invades lungs, producing fever, cough, hookworm infections insinuate a skin reaction, increased white blood cells, a pulmonary reaction, and skin rash. Iron deficiency anaemia due to blood loss is a common symptom, STH is often associated with malnutrition in children as it worsens their nutritional status in multiple ways. The worms can induce bleeding, competition for nutrients, frequent anaemia. Soil-transmitted helminths can also cause loss of appetite and these nutritional knock on effects of STH can have a significant impact on the mental and physical development of children. In endemic countries, communities remain suppressed due to malnourishment, cognitive disability, soil-transmitted helminths are essentially intestinal parasites and their eggs are liberated along the faeces of infected persons into the soil. Ascaris and hookworm eggs become infective as they develop into larvae in soil, infection occurs when vegetables and fruits, contaminated with soil infested eggs, are consumed, or when hands or fingers have been contaminated with dirt carrying the eggs are put in the mouth. On the other hand, hookworm eggs are not directly infective and they hatch in soil, releasing mobile larvae that can penetrate the skin. Thus infection is acquired through contact with contaminated soil
11.
Hand washing
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Hand washing, also spelled handwashing and known as hand hygiene, is the act of cleaning ones hands for the purpose of removing soil, dirt, and microorganisms. This may be done with or without the use of water, other liquids, medical hand hygiene pertains to the hygiene practices related to the administration of medicine and medical care that prevents or minimizes disease and the spreading of disease. The main medical purpose of washing hands is to cleanse the hands of pathogens and this is especially important for people who handle food or work in the medical field, but it is also an important practice for the general public. Handwashing with soap consistently at critical moments during the day prevents the spread of diseases like diarrhoea, Handwashing also protects against impetigo which is transmitted through direct physical contact. People can become infected with diseases such as influenza or the common cold, for example, if they do not wash their hands before touching their eyes, nose. As a general rule, hand washing protects people poorly or not at all from droplet and airborne diseases, such as measles, chickenpox, influenza and this simple action can reduce the rate of mortality from these diseases by almost 50 percent. Pneumonia, a major ARI, is the one cause of mortality among children under five years old. Diarrhea and pneumonia together account for almost 3.5 million child deaths annually, hand washing is usually integrated together with other sanitation interventions as part of water, sanitation and hygiene programmes. A possible small detrimental effect of washing is that frequent hand washing can lead to skin damage due to drying of the skin. Excessive hand washing is commonly seen as a symptom of obsessive-compulsive disorder, in many countries, there is a low prevalence of handwashing with soap. A study of handwashing in 54 countries in 2015 found that on average,38. 7% of households practised handwashing with soap, several Behaviour change methodologies now exist to increase uptake of the behaviour of handwashing with soap at the critical times. Group handwashing for school children at set times of the day is one option in developing countries to engrain handwashing in childrens behaviors. The Essential Health Care Program implemented by the Philippine Department of Education in the Philippines is an example of at scale action to promote children’s health and education. Deworming twice a year, supplemented with washing hands daily with soap and it has also been successfully implemented in Indonesia. Removal of microorganisms from skin is enhanced by the addition of soaps or detergents to water, the main action of soaps and detergents is to reduce barriers to solution, and increase solubility. Water is an inefficient skin cleanser because fats and proteins, which are components of soil, are not readily dissolved in water. Cleansing is, however, aided by a flow of water. Solid soap, because of its nature, may hold bacteria acquired from previous uses
12.
Sanitation
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These hazards may be physical, microbiological, biological or chemical agents of disease. Wastes that can cause problems include human and animal excreta, solid wastes, domestic wastewater, industrial wastes. Hygienic means of prevention may involve engineering solutions, simple technologies, or even simply by behavior changes in personal hygiene practices, providing sanitation to people requires a systems approach, rather than only focusing on the toilet or wastewater treatment plant itself. The experience of the user, excreta and wastewater collection methods, transportation or conveyance of waste, treatment, the main objective of a sanitation system is to protect and promote human health by providing a clean environment and breaking the cycle of disease. The World Health Organization defines the term sanitation as follows, Sanitation generally refers to the provision of facilities and services for the disposal of human urine. The word sanitation also refers to the maintenance of conditions, through services such as garbage collection. There are some variations on the definition of sanitation in use. For example, for many organisations, hygiene promotion is seen as an part of sanitation. Despite the fact that sanitation includes wastewater treatment, the two terms are often use side by side as sanitation and wastewater management, Sanitation should be regarded with a systems approach in mind which includes collection/containment, conveyance/transport, treatment, disposal or reuse. Effective sanitation systems provide barriers between excreta and humans in such a way as to break the transmission cycle. This aspect is visualised with the F-diagram where all routes of fecal-oral disease transmission begin with the letter F, feces, fingers, flies, fields, fluids. Container-based sanitation is usually provided as a service involving provision of types of portable toilets. In most cases, CBS is based on the use of urine-diverting dry toilets, the term dry sanitation is somewhat misleading as sanitation includes hand-washing and can never be dry. A more precise term would be dry excreta management, when people speak of dry sanitation they usually mean sanitation systems with dry toilets with urine diversion, in particular the urine-diverting dry toilet. Put in other words, Ecosan systems safely recycle excreta resources to crop production in such a way that the use of resources is minimised. Ecosan is also called resource-oriented sanitation, environmental sanitation encompasses the control of environmental factors that are connected to disease transmission. Subsets of this category are solid waste management, water and wastewater treatment, industrial waste treatment and noise, improved sanitation and unimproved sanitation refers to the management of human feces at the household level. This terminology is the used to describe the target of the Millennium Development Goal on sanitation, by the WHO/UNICEF Joint Monitoring Programme for Water Supply
13.
Toilets
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A toilet is a sanitation fixture used for the storing or disposal of human urine and feces. In developed countries, different forms of flush toilets are common. These are connected to a system in most urban areas. In many developing countries, especially in areas, dry toilets such as pit latrines. Dry toilets are usually placed in outhouses, i. e. not inside the dwelling, in many countries, private homes are designed with the flush toilet and the bath or shower in the same room, the bathroom, to simplify plumbing and reduce cost. Other cultures find this insanitary, and have one room for body-washing, public toilets are installed where their use is expected on a permanent basis, while portable toilets may be brought in for large but temporary gatherings. Chemical toilets are used in various contexts, such as passenger trains. Serious waterborne diseases such as cholera and diarrhea occur when open defecation or poor sanitation permits human waste to pollute water supplies, historically, sanitation has been a concern from the earliest stages of human settlements. The Indus Valley Civilization is particularly notable for its extensive sanitation works, for the most part, early cities emptied their waste into rivers or seas manually or via open ditches. Sanitation in ancient Rome was notably advanced, as were some of the reredorters of medieval monasteries, a precursor to the modern flush toilet system was designed by John Harington in 1596 but did not become common until the late 19th century. Even London, at time the worlds largest city, did not require indoor toilets in its building codes until after the First World War. A typical flush toilet is a ceramic bowl connected on the up side to a cistern that enables rapid filling with water, when a toilet is flushed, the sewage should flow into a septic tank or into a system connected to a Sewage treatment plant. However, in countries, this treatment does not happen. The water in the bowl is connected to a pipe shaped like an upside-down U. One side of the U channel is arranged as a tube longer than the water in the bowl is high. The siphon tube connects to the drain, the bottom of the drain pipe limits the height of the water in the bowl before it flows down the drain. The water in the acts as a barrier to sewer gas entering the building. Sewer gas escapes through a vent pipe attached to the sewer line, the amount of water used by conventional flush toilets usually makes up a significant portion of personal daily water usage
14.
Tropical countries
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The tropics are a region of the Earth surrounding the equator. The tropics are also referred to as the zone and the torrid zone. The tropics include all the areas on the Earth where the Sun is at a point directly overhead at least once during the solar year. The tropics are distinguished from the climatic and biomatic regions of Earth, which are the middle latitudes. Tropical is sometimes used in a sense for a tropical climate to mean warm to hot and moist year-round. Many tropical areas have a dry and wet season, the wet season, rainy season or green season, is the time of year, ranging from one or more months, when most of the average annual rainfall in a region falls. Areas with wet seasons are disseminated across portions of the tropics and subtropics, under the Köppen climate classification, for tropical climates, a wet season month is defined as a month where average precipitation is 60 millimetres or more. Tropical rainforests technically do not have dry or wet seasons, since their rainfall is distributed through the year. When the wet season occurs during the season, or summer, precipitation falls mainly during the late afternoon. The wet season is a time when air quality improves, freshwater quality improves and vegetation grows significantly, floods cause rivers to overflow their banks, and some animals to retreat to higher ground. Soil nutrients diminish and erosion increases, the incidence of malaria increases in areas where the rainy season coincides with high temperatures. Animals have adaptation and survival strategies for the wetter regime, unfortunately, the previous dry season leads to food shortages into the wet season, as the crops have yet to mature. Regions within the tropics may well not have a tropical climate, there are alpine tundra and snow-capped peaks, including Mauna Kea, Mount Kilimanjaro, and the Andes as far south as the northernmost parts of Chile and Argentina. Under the Köppen climate classification, much of the area within the tropics is classed not as tropical but as dry including the Sahara Desert. Tropical plants and animals are those native to the tropics. Tropical ecosystems may consist of rainforests, dry forests, spiny forests, desert. There are often significant areas of biodiversity, and species present, particularly in rainforests. In biogeography, the tropics are divided into Paleotropics and Neotropics, together, they are sometimes referred to as the Pantropic
15.
Vaccine
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A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism and is made from weakened or killed forms of the microbe. Vaccines can be prophylactic, or therapeutic, the administration of vaccines is called vaccination. The effectiveness of vaccination has been studied and verified, for example, the influenza vaccine, the HPV vaccine. The World Health Organization reports that licensed vaccines are available to prevent or contribute to the prevention. The terms vaccine and vaccination are derived from Variolae vaccinae, the term devised by Edward Jenner to denote cowpox. He used it in 1798 in the title of his Inquiry into the. Variolae vaccinae. known. the Cow Pox. In 1881, to honor Jenner, Louis Pasteur proposed that the terms should be extended to cover the new protective inoculations then being developed, vaccines have historically been the most effective means to fight and eradicate infectious diseases. Limitations to their effectiveness, nevertheless, exist, sometimes, protection fails because the hosts immune system simply does not respond adequately or at all. Lack of response commonly results from factors such as diabetes, steroid use. Adjuvants commonly are used to boost immune response, particularly for older people, the efficacy or performance of the vaccine is dependent on a number of factors, the disease itself the strain of vaccine whether the vaccination schedule has been properly observed. Idiosyncratic response to vaccination, some individuals are non-responders to certain vaccines, assorted factors such as ethnicity, age, or genetic predisposition. If a vaccinated individual does develop the disease vaccinated against, the disease is likely to be less virulent than in unvaccinated victims, in 1958, there were 763,094 cases of measles in the United States,552 deaths resulted. After the introduction of new vaccines, the number of cases dropped to fewer than 150 per year, in early 2008, there were 64 suspected cases of measles. Vaccines have contributed to the eradication of smallpox, one of the most contagious, other diseases such as rubella, polio, measles, mumps, chickenpox, and typhoid are nowhere near as common as they were a hundred years ago. As long as the vast majority of people are vaccinated, it is more difficult for an outbreak of disease to occur. This effect is called herd immunity, polio, which is transmitted only between humans, is targeted by an extensive eradication campaign that has seen endemic polio restricted to only parts of three countries. However, the difficulty of reaching all children as well as cultural misunderstandings have caused the anticipated eradication date to be missed several times, vaccination given during childhood is generally safe
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Neglected tropical disease
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Neglected tropical diseases are a diverse group of tropical infections which are especially common in low-income populations in developing regions of Africa, Asia, and the Americas. They are caused by a variety of such as viruses, bacteria, protozoa. These diseases are contrasted with the big three diseases, which receive greater treatment and research funding. In sub-Saharan Africa, the impact of diseases as a group is comparable to malaria. NTD co-infection can also make HIV/AIDS and tuberculosis more deadly, in some cases, the treatments are relatively inexpensive. For example, the treatment for schistosomiasis is US$0.20 per child per year, nevertheless, control of neglected diseases is estimated to require funding of between US$2 billion to US$3 billion over the next five to seven years. Some pharmaceutical companies have committed to donating all the drug therapies required, however, preventative measures are often more accessible in the developed world, but not universally available in poorer areas. Within developed countries, neglected tropical diseases affect the very poorest in society, in the United States, there are up to 1.46 million families in poverty, with 2.8 million children living on less than two dollars a day. In countries such as these, the burdens of neglected diseases are often overshadowed by other public health issues. However, many of the same issues put populations at risk in developed as developing nations, for example, from poverty stem problems such as lack of adequate housing, thus exposing individuals to the vectors of these diseases. Seventeen neglected tropical diseases are prioritized by WHO, though other organizations define NTDs differently and these diseases are common in 149 countries, affecting more than 1.4 billion people and costing developing economies billions of dollars every year. They resulted in 142,000 deaths in 2013—down from 204,000 deaths in 1990, of these 17, two were targeted for eradication, and four for elimination. There is some debate among the WHO, CDC, and infectious disease experts over which diseases are classified as neglected tropical diseases and these diseases result from four different classes of causative pathogens, protozoa, bacteria, helminths or metazoan worms, and viruses. The World Health Organization recognizes the seventeen diseases below as neglected tropical diseases, Buruli ulcer is caused by the bacterium Mycobacterium ulcerans. It is related to the family of organisms that cause tuberculosis and leprosy, but Mycobacterium ulcerans produces a toxin, mycolactone, the prevalence of Buruli ulcer is unknown. The risk of mortality is low, although secondary infections can be lethal, morbidity takes the form of deformity, disability, and skin lesions, which can be prevented through early treatment and treated with antibiotics and surgery. It is found in Africa, Asia, and Latin America, Chagas disease is also known as American trypanosomiasis. There are approximately 15 million people infected with Chagas disease, the chance of morbidity is higher for immuno-compromised individuals, children, and elderly, but very low if treated early
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Salmonella typhi
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Enterica is a subspecies of Salmonella enterica, the rod-shaped, flagellated, aerobic, Gram-negative bacterium. Many of the pathogenic serovars of the S. enterica species are in this subspecies, enterica contains a large number of serovars which can infect a broad range of vertebrate hosts. The individual members range from being highly host-adapted to displaying a broad host range, a number of techniques are currently used to differentiate between serotypes. These include looking for the presence or absence of antigens, phage typing, molecular fingerprinting and biotyping, a possible factor in determining the host range of particular serovars is phage-mediated acquisition of a small number of genetic elements that enable infection of a particular host. A selection of serovars, with known hosts listed, since there are more than 2500 serovars of Salmonella enterica subsp. One strain of Salmonella that has recently been emerging in the United States is Salmonella javiana, an outbreak occurred in 2002, there were 141 cases that occurred among the participants of the U. S. Out of the 141 cases, most of the cases were either transplant recipients or people receiving immunosuppressive therapy, there is an increasing number of Salmonella serotypes that are multidrug resistant, which was identified by the CDCs National Antimicrobial Resistance Monitoring System. Salmonella javiana causes 4% of nontyphodial Salmonella infections in the United States each year and it is thought that these metabolic capabilities are important for obtaining nutrients in the challenging and nutrient-limited inflamed gut environment. The serovars can be designated fully or in a shortened form, the short form lists the genus, Salmonella, which is followed by the capitalized and non-italicized serovar. The full designation for Salmonella Typhi is Salmonella enterica subsp, each serovar can have many strains, as well, which allows for a rapid increase in the total number of antigenically variable bacteria. Invasive strains of salmonella, such as Salmonella Typhimurium ST313 have recently been labelled as emerging diseases in Africa
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Schistosoma mansoni
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Schistosoma mansoni is a significant parasite of humans, a trematode that is one of the major agents of the disease schistosomiasis which is one type of helminthiasis, a neglected tropical disease. The schistosomiasis caused by Schistosoma mansoni is intestinal schistosomiasis, Schistosomes are atypical trematodes in that the adult stages have two sexes and are located in blood vessels of the definitive host. Most other trematodes are hermaphroditic and are found in the tract or in organs. S. mansoni is named after Sir Patrick Manson, who first identified it in Formosa, Schistosomes, unlike other trematodes, are long and slim worms. The male S. mansoni is approximately 1 cm long and is 0.1 cm wide and it is white, and it has a funnel-shaped oral sucker at its anterior end followed by a second pediculated sucker. The external part of the worm is composed of a bilayer, which is continuously renewed as the outer layer, known as the membranocalyx. The tegument bears a number of small tubercules. The suckers have small thorns in their part as well as in the buttons around them. The male genital apparatus is composed of 6 to 9 testicular masses, the copula happens through the coaptation of the male and female genital orifices. The female has a body, longer and thinner than the males. The female parasite is darker, and it looks gray, the darker color is due to the presence of a pigment in its digestive tube. This pigment is derived from the digestion of blood, the ovary is elongated and slightly lobulated and is located on the anterior half of the body. A short oviduct conducts to the ootype, which continues with the uterine tube, in this tube it is possible to find 1 to 2 eggs but only 1 egg is observed in the ootype at any one time. The posterior two-thirds of the contain the vittelogenic glands and their winding canal. The digestive tube begins at the extremity of the worm. The digestive tube is composed of an esophagus, which divides in two branches and that reunite in a single cecum, the intestines end blindly, meaning that there is no anus. The developing parasites lyse host red blood cells to gain access to nutrients, while hemoglobin is digested intracellularly, initiated by salivary gland enzymes, iron waste products cannot be used by the worms, and are typically discarded via regurgitation. Kasschau et al. tested the effect of temperature and pH on the ability of developing S. mansoni to lyse red blood cells, after the eggs of the human-dwelling parasite are emitted in the faeces and into the water, the ripe miracidium hatches out of the egg
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Sub-saharan Africa
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Sub-Saharan Africa is, geographically, the area of the continent of Africa that lies south of the Sahara. According to the UN, it consists of all African countries that are fully or partially located south of the Sahara and it contrasts with North Africa, whose territories are part of the League of Arab states within the Arab world. Somalia, Djibouti, Comoros and Mauritania are geographically in Sub-Saharan Africa, the Sahel is the transitional zone between the Sahara and the tropical savanna and forest-savanna mosaic to the south. The Sahara pump theory explains how flora and fauna left Africa to penetrate the Middle East, African pluvial periods are associated with a wet Sahara phase during which larger lakes and more rivers existed. Geographers historically divided the region into several distinct ethnographic sections based on each areas respective inhabitants, commentators in Arabic in the medieval period used the general term bilâd as-sûdân for the vast Sudan region, or sometimes extending from the coast of West Africa to Western Sudan. Its equivalent in Southeast Africa was Zanj, which was situated in the vicinity of the Great Lakes region. The geographers drew an explicit distinction between the Sudan region and its analogue Zanj, from the area to their extreme east on the Red Sea coast in the Horn of Africa. In modern-day Ethiopia and Eritrea was Al-Habash or Abyssinia, which was inhabited by the Habash or Abyssinians, Sub-Saharan Africa has a wide variety of climate zones or biomes. South Africa and the Democratic Republic of the Congo in particular are considered Megadiverse countries, the Sahel shoots across all of Africa at a latitude of about 10° to 15° N. Countries that include parts of the Sahara Desert proper in their territories and parts of the Sahel in their southern region include Mauritania, Mali, Niger, Chad. The Sahel has a hot semi-arid climate, South of the Sahel, there is a belt of savanna, widening to include most of South Sudan and Ethiopia in the east. The Serengeti ecosystem is located in northwestern Tanzania and extends to southwestern Kenya, the Kalahari Basin includes the Kalahari Desert surrounded by a belt of semi-desert. The Bushveld is a tropical ecoregion of Southern Africa. The Karoo is a semi-desert in western South Africa and this occurred 10 million to 5 million years ago. By 3 million years ago several australopithecine hominid species had developed throughout southern, eastern and they were tool users rather than tool manufacturers. The tools were classed as Oldowan, roughly 1.8 million years ago, Homo ergaster first appeared in the fossil record in Africa. From Homo ergaster, Homo erectus evolved 1.5 million years ago, some of the earlier representatives of this species were small-brained and used primitive stone tools, much like H. habilis. The brain later grew in size, and H. erectus eventually developed a complex stone tool technology called the Acheulean
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Vitamin A
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Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids. Vitamin A has multiple functions, it is important for growth and development, for the maintenance of the immune system and good vision. Vitamin A is needed by the retina of the eye in the form of retinal, which combines with protein opsin to form rhodopsin, Vitamin A also functions in a very different role as retinoic acid, which is an important hormone-like growth factor for epithelial and other cells. In foods of animal origin, the form of vitamin A is an ester, primarily retinyl palmitate. The retinol form functions as a form of the vitamin. All forms of vitamin A have a ring to which an isoprenoid chain is attached, called a retinyl group. Both structural features are essential for vitamin activity, the orange pigment of carrots can be represented as two connected retinyl groups, which are used in the body to contribute to vitamin A levels. Alpha-carotene and gamma-carotene also have a single group, which give them some vitamin activity. None of the other carotenes have vitamin activity, the carotenoid beta-cryptoxanthin possesses an ionone group and has vitamin activity in humans. Vitamin A can be found in two forms in foods, Retinol, the form of vitamin A absorbed when eating animal food sources, is a yellow. Since the pure form is unstable, the vitamin is found in tissues in a form of retinyl ester. It is also produced and administered as esters such as retinyl acetate or palmitate. Vitamin A deficiency is estimated to approximately one third of children under the age of five around the world. It is estimated to claim the lives of 670,000 children under five annually, approximately 250, 000–500,000 children in developing countries become blind each year owing to vitamin A deficiency, with the highest prevalence in Southeast Asia and Africa. Vitamin A deficiency is the cause of preventable childhood blindness. It also increases the risk of death from common childhood conditions such as diarrhea, UNICEF regards addressing vitamin A deficiency as critical to reducing child mortality, the fourth of the United Nations Millennium Development Goals. Vitamin A deficiency can occur as either a primary or a secondary deficiency, early weaning from breastmilk can also increase the risk of vitamin A deficiency. Vitamin A is a vitamin and depends on micellar solubilization for dispersion into the small intestine
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Helminth
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Helminths, also commonly known as parasitic worms, are large multicellular organisms, which when mature can generally be seen with the naked eye. They are often referred to as intestinal worms even though not all helminths reside in the intestines, for example schistosomes are not intestinal worms, but rather reside in blood vessels. There is no consensus on the taxonomy of helminths, it is more of a commonly used term to describe certain worms with superficial similarities. Many, but not all, of the referred to as helminths belong to the group of intestinal parasites. An infection by a helminth is known as helminthiasis, soil-transmitted helminthiasis, helminths are worm-like organisms living in and feeding on living hosts, receiving nourishment and protection while disrupting their hosts nutrient absorption, causing weakness and disease. Those that live inside the digestive tract are called intestinal parasites and they can live inside humans and other animals. In their adult form, helminths cannot multiply in humans, helminths are able to survive in their mammalian hosts for many years due to their ability to manipulate the immune response by secreting immunomodulatory products. Helminth ova have a shell that protects the eggs against a range of environmental conditions. Helminthology is the study of worms and their effects on their hosts. The word helminth comes from Greek hélmins, a kind of worm, there is no real consensus on the taxonomy of the helminths, particularly with the nematodes. The term helminth contains a number of phyla, many of which are completely unrelated, however, for practical considerations the term is still used nowadays to describe four groups with superficial similarities, the phyla Annelida, Platyhelminths, Nematoda and Acanthocephala. There is in fact no helminth classification, it is an artificial term, the latter are further divided into cestodes and trematodes depending on whether or not they have a segmented body. Ringworm is actually caused by fungi and not by a parasitic worm. Helminths are a group of unrelated organisms which share a similar form. Helminths include members of the taxa, monogeneans, cestodes, nematodes. The number of different helminth species is vast, it is estimated to be one million species. The nematodes are the most diverse of all the helminths with the highest number of species, there may be as many as 300,000 species of parasites affecting vertebrates, and as many as 300 affecting humans alone. Characteristics that are common for all include, Life time
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Trichuris
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Trichuris, often referred to as whipworms, is a genus of parasite worms from the roundworm family Trichuridae, which is a type of helminth. The name whipworm refers to the shape of the worm, they look like whips with wider handles at the posterior end, the name Trichocephalus is sometimes used for this genus. Trichurias is a soil-transmitted helminthias and belongs to the group of neglected tropical diseases, researchers are currently facing difficulties completely differentiating the numerous species under the Trichuris genus. When different whipworm species were discovered, the factor used to differentiate species was the length of the spicule sheath. However, it was discovered that many species had similar spicule sheath lengths. Therefore, researchers began to compare other morphologies, such as the structure or orientation surrounding female sex organs of species suspected to be similar, relatively recently, studies have been conducted to differentiate similar Trichuris species based on mitochondrial DNA differences, a much more accurate method of distinction. However, there is currently a paucity of research devoted to encoding the DNA of each, as a result, Trichuris species distinction is still largely based on morphological differences. Currently, the life cycle of the whipworm is not completely understood. However, all species have a similar general life cycle. Whipworm eggs are first ingested by the host and they eventually reach the duodenum of the small intestine, where the eggs ultimately hatch. The larva from these eggs travel into the large intestine’s cecum, for approximately four weeks, the whipworms feed on blood vessels located within the cecum. Eventually, the leave the cecum and begin to lay thousands of eggs. These unembryonated eggs are released out of the host through feces. The process from egg ingestion to release takes approximately twelve weeks, the released eggs become embryonated in approximately nine to twenty-one days and are eventually ingested by another host. Whipworm eggs have thick, lemon-shaped, light yellow shells, located on opposite ends of the shells are plugs that protect the eggs in unfavorable conditions such as rugged dirt and the acidic environment of the small intestine. The actual egg is covered by a vitelline membrane, when the egg first exits the uterus of their mother, they are composed solely of yolk granules. Over a period of 72 hours, the egg undergoes mitotic division into two blastomeres that are separated by a transverse cleavage, two additional cleavages occur within at least 96 hours so that the egg is now composed of four cells. Cellular division continues in this manner and the stage is reached within the next week
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Vegetables
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In everyday usage, a vegetable is any part of a plant that is consumed by humans as food as part of a meal. The term vegetable is somewhat arbitrary, and largely defined through culinary and it normally excludes other food derived from plants such as fruits, nuts, and cereal grains, but includes seeds such as pulses. The original meaning of the vegetable, still used in biology, was to describe all types of plant, as in the terms vegetable kingdom. At first, plants which grew locally would have been cultivated, nowadays, most vegetables are grown all over the world as climate permits, and crops may be cultivated in protected environments in less suitable locations. China is the largest producer of vegetables and global trade in agricultural products allows consumers to purchase vegetables grown in faraway countries, the scale of production varies from subsistence farmers supplying the needs of their family for food, to agribusinesses with vast acreages of single-product crops. Depending on the type of vegetable concerned, harvesting the crop is followed by grading, storing, processing, and marketing. Vegetables can be either raw or cooked and play an important role in human nutrition, being mostly low in fat and carbohydrates. Many nutritionists encourage people to consume plenty of fruit and vegetables, the word vegetable was first recorded in English in the early 15th century. It comes from Old French, and was applied to all plants. It derives from Medieval Latin vegetabilis growing, flourishing, a change from a Late Latin meaning to be enlivening, quickening. The meaning of vegetable as a plant grown for food was not established until the 18th century, in 1767, the word was specifically used to mean a plant cultivated for food, an edible herb or root. The year 1955 saw the first use of the shortened, slang term veggie, the broadest definition is the words use adjectivally to mean matter of plant origin to distinguish it from animal, meaning matter of animal origin. More specifically, a vegetable may be defined as any plant, part of which is used for food, a secondary meaning then being the edible part of such a plant. A more precise definition is any plant part consumed for food that is not a fruit or seed, falling outside these definitions are edible fungi and edible seaweed which, although not parts of plants, are often treated as vegetables. In everyday language, the fruit and vegetable are mutually exclusive. Fruit has a precise meaning, being a part that developed from the ovary of a flowering plant. This is considerably different from the words culinary meaning, while peaches, plums, and oranges are fruit in both senses, many items commonly called vegetables, such as eggplants, bell peppers, and tomatoes, are botanically fruits. The question of whether the tomato is a fruit or a vegetable found its way into the United States Supreme Court in 1893
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Prolate spheroid
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A spheroid, or ellipsoid of revolution, is a quadric surface obtained by rotating an ellipse about one of its principal axes, in other words, an ellipsoid with two equal semi-diameters. If the ellipse is rotated about its axis, the result is a prolate spheroid. If the ellipse is rotated about its axis, the result is an oblate spheroid. If the generating ellipse is a circle, the result is a sphere, because of the combined effects of gravity and rotation, the Earths shape is not quite a sphere but instead is slightly flattened in the direction of its axis of rotation. For that reason, in cartography the Earth is often approximated by an oblate spheroid instead of a sphere, the current World Geodetic System model uses a spheroid whose radius is 6,378.137 km at the equator and 6,356.752 km at the poles. The semi-major axis a is the radius of the spheroid. There are two cases, c < a, oblate spheroid c > a, prolate spheroid The case of a = c reduces to a sphere. An oblate spheroid with c < a has surface area S o b l a t e =2 π a 2 where e 2 =1 − c 2 a 2. The oblate spheroid is generated by rotation about the z-axis of an ellipse with semi-major axis a and semi-minor axis c, therefore e may be identified as the eccentricity. A prolate spheroid with c > a has surface area S p r o l a t e =2 π a 2 where e 2 =1 − a 2 c 2. The prolate spheroid is generated by rotation about the z-axis of an ellipse with semi-major axis c and semi-minor axis a and these formulas are identical in the sense that the formula for Soblate can be used to calculate the surface area of a prolate spheroid and vice versa. However, e then becomes imaginary and can no longer directly be identified with the eccentricity, both of these results may be cast into many other forms using standard mathematical identities and relations between parameters of the ellipse. The volume inside a spheroid is 4π/3a2c ≈4. 19a2c, if A = 2a is the equatorial diameter, and C = 2c is the polar diameter, the volume is π/6A2C ≈0. 523A2C. Both of these curvatures are always positive, so every point on a spheroid is elliptic. These are just two of different parameters used to define an ellipse and its solid body counterparts. The most common shapes for the density distribution of protons and neutrons in an atomic nucleus are spherical, prolate and oblate spheroidal, deformed nuclear shapes occur as a result of the competition between electromagnetic repulsion between protons, surface tension and quantum shell effects. An extreme example of a planet in science fiction is Mesklin, in Hal Clements novel Mission of Gravity. The prolate spheroid is the shape of the ball in several sports, several moons of the Solar system approximate prolate spheroids in shape, though they are actually triaxial ellipsoids
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Gridiron football
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Gridiron football, or North American football, is a form of football primarily played in the United States and Canada. The predominant forms of football are American football and Canadian football. The grid system was abandoned in favor of the system of lines and hash marks used today. Gridiron football developed in the late 19th century out of the games now known as rugby football. Walter Camp is credited with creating many of the rules that differentiate gridiron football from its older counterparts, because the two sets of lines had the same spacing and were perpendicular, they divided the field into squares, resembling a checkerboard or gridiron pattern. The word gridiron, in use since the 14th century, refers to a grid for cooking food over a fire. As described in Outdoor Sports and Games, by Claude H. Miller, at each end are goal posts set 18 feet 6 inches apart, with a crossbar 10 feet above the ground. The field is marked off in chalk lines similar to a tennis court, the centre of the field where the play starts is 55 yards from either end. The lines on a football field make an effect and have given to the field the name of gridiron. As a result, the name of the field, gridiron, was applied to the game itself, the ball would be snapped in the grid in which it was downed on the previous play. The grid system was abandoned in favor of the system of lines and hash marks used today. Especially outside of the U. S. and Canada, the gridiron and gridiron football are often used to distinguish the North American sport from other codes of football. Gridiron is the word for the sport in Australia and New Zealand. In the United States and Canada, the game is known unambiguously as football, association football is known in these countries as soccer and rugby football, seldom encountered in the U. S. is known as rugby or, especially in Canada, English rugby. American football is the most common and widely known of the football codes. It is played with players to a side, four downs. The premier professional league in the United States, the National Football League, has its own distinct code, colleges in the United States generally play under the code defined in NCAA Football Rules and Interpretations. Youth games generally follow NFHS code with modifications, adult semi-pro, alternative and minor professional, amateur, touch, flag, etc. may follow any one of these codes or use their own rules
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Geophagy
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Geophagia is the practice of eating earth or soil-like substrates such as clay or chalk. It occurs in animals where it may be a normal or abnormal behaviour. Human geophagia may be related to pica, a disorder in the Diagnostic. Here, a white clay was found alongside the bones of Homo habilis. Geophagia is nearly universal around the world in tribal and traditional rural societies, in the ancient world, several writers noted the use of geophagia. Pliny is said to have noted the use of soil on Lemnos, an island of Greece, the textbook of Hippocrates mentions geophagia, and the famous medical textbook called De Medicina edited by A Cornelius Celsus seems to link anaemia to geophagia. Geophagia was common among slaves who were nicknamed clay-eaters because they had known to consume clay, as well as spices, ash, chalk, grass, plaster, paint. The literature also states, Many men believed that eating clay increased sexual prowess, geophagia among southerners may have been caused by the high prevalence of hookworm disease, in which the desire to consume soil is a symptom. In Africa, kaolin, sometimes known as kalaba, calaba, kaolin for human consumption is sold at most markets in Cameroon and is often flavoured with spices such as black pepper and cardamom. Consumption is greater among women, especially during pregnancy, in Haiti, people afflicted by poverty are known to eat biscuits made from soil, salt, and vegetable shortening. These biscuits hold minimal nutritional value, but manages to keep the poor alive, however, their long-term consumption is reported to cause stomach pains, and could be a source of malnutrition, and is not recommended by doctors. In the United States, cooked, baked, and processed dirt and clay are sold in food stores. In the rural areas of Mississippi and other states, the consumption of clay-rich dirt has been a common custom and has been practiced by poor whites. However, geophagia has become prevalent as rural Americans assimilate into urban culture. Bentonite clay is available worldwide as an aid, kaolin is also widely used as a digestive aid. Attapulgite, another type of clay, is an ingredient in many anti-diarrheal medicines. Geophagia is widespread in the animal kingdom, galen, the Greek philosopher and physician, was the first to record the use of clay by sick or injured animals in the second century AD. This type of geophagia has been documented in species of mammals, birds, reptiles, butterflies and isopods
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Difetarsone
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Various studies have shown it to be particularly effective against Trichuris trichiura, commonly known as the whipworm. Prior to the use in the early 1970s, there were few effective treatments for this infection. It has also used to treat Entamoeba histolytica infections. Difetarsone often has minor side effects, which include rashes, nausea and it has also resulted in angioedema in at least one known case
. PMID 27733282. doi:10.1016/S0140-6736(16)31678-6.
