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Micronutrient Deficiency
Micronutrient deficiency is defined as the sustained insufficient supply of vitamins and minerals needed for growth and development, as well as to maintain optimal health. Since some of these compounds are considered essentials (we need to obtain them from the diet), micronutrient deficiencies are often the result of an inadequate intake. However, it can also be associated to poor intestinal absorption, presence of certain chronic illnesses and elevated requirements. Prevalence Micronutrient deficiencies are considered a public health problem worldwide. For over 30 years it has been estimated that more than two billion people of all ages are affected by this burden, while a recently published study based on individual-level biomarker data estimated that there are 372 million children aged 5 years and younger, and 1.2 billion non-pregnant women of reproductive age with one or more micronutrient deficiencies globally, affecting greatly Asia and sub-Saharan Africa. Women of reproducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pellagra
Pellagra is a disease caused by a lack of the vitamin niacin (vitamin B3). Symptoms include inflamed skin, diarrhea, dementia, and sores in the mouth. Areas of the skin exposed to friction and radiation are typically affected first. Over time affected skin may become darker, stiffen, peel, or bleed. There are two main types of pellagra, primary and secondary. Primary pellagra is due to a diet that does not contain enough niacin and tryptophan. Secondary pellagra is due to a poor ability to use the niacin within the diet. This can occur as a result of alcoholism, long-term diarrhea, carcinoid syndrome, Hartnup disease, and a number of medications such as isoniazid. Diagnosis is typically based on symptoms and may be assisted by urine testing. Treatment is with either nicotinic acid or nicotinamide supplementation. Improvements typically begin within a couple of days. General improvements in diet are also frequently recommended. Decreasing sun exposure via sunscreen and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Development Of The Nervous System In Humans
The development of the nervous system in humans, or neural development, or neurodevelopment involves the studies of embryology, developmental biology, and neuroscience. These describe the cellular and molecular mechanisms by which the complex nervous system forms in humans, develops during prenatal development, and continues to develop postnatally. Some landmarks of neural development in the embryo include: # The formation and cellular differentiation, differentiation of neurons from stem cell precursors (neurogenesis) # The cellular migration, migration of immature neurons from their birthplaces in the embryo to their final positions. # The outgrowth of axons from neurons and the axon guidance, guidance of the motile growth cone through the embryo towards postsynaptic partners. # The generation of synapses between axons and their postsynaptic partners. # The synaptic pruning that occurs in adolescence. # The lifelong synaptic plasticity, changes in synapses which are thought ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with the chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorus
Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared artificially, the two most common allotropes being white phosphorus and red phosphorus. With as its only stable isotope, phosphorus has an occurrence in Earth's crust of about 0.1%, generally as phosphate rock. A member of the pnictogen family, phosphorus readily forms a wide variety of organic compound, organic and inorganic compound, inorganic compounds, with as its main oxidation states +5, +3 and −3. The isolation of white phosphorus in 1669 by Hennig Brand marked the scientific community's first discovery since Antiquity of an element. The name phosphorus is a reference to the Phosphorus (morning star), god of the Morning star in Greek mythology, inspired by the faint glow of white phosphorus when exposed to oxygen. This property is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. It is a common element in the universe, estimated at Abundance of the chemical elements, seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element chemical bond, bond to form N2, a colourless and odourless diatomic molecule, diatomic gas. N2 forms about 78% of Atmosphere of Earth, Earth's atmosphere, making it the most abundant chemical species in air. Because of the volatility of nitrogen compounds, nitrogen is relatively rare in the solid parts of the Earth. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772 and independently by Carl Wilhelm Scheele and Henry Cavendish at about the same time. The name was suggested by French chemist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Nutrition
Plant nutrition is the study of the chemical elements and compounds necessary for plant growth and reproduction, plant metabolism and their external supply. In its absence the plant is unable to complete a normal life cycle, or that the element is part of some essential plant constituent or metabolite. This is in accordance with Justus von Liebig's law of the minimum. The total essential plant nutrients include seventeen different elements: carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil (exceptions include some parasitic or carnivorous plants). Plants must obtain the following mineral nutrients from their growing medium: * The macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), magnesium (Mg), carbon (C), hydrogen (H), oxygen (O) * The micronutrients (or trace minerals): iron (Fe), boron (B), chlorine (Cl), manganese (Mn), zinc (Zn), copper (Cu), mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll. Exceptions are parasitic plants that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Most plants are multicellular organism, multicellular, except for some green algae. Historically, as in Aristotle's biology, the plant kingdom encompassed all living things that were not animals, and included algae and fungi. Definitions have narrowed since then; current definitions exclude fungi and some of the algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants (hornworts, liverworts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid collection of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three- state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micronutrient
Micronutrients are essential chemicals required by organisms in small quantities to perform various biogeochemical processes and regulate physiological functions of cells and organs. By enabling these processes, micronutrients support the health of organisms throughout life. For humans, micronutrients typically take one of three forms: vitamins, trace elements, and dietary minerals. Human micronutrient requirements are in amounts generally less than 100 milligrams per day, whereas macronutrients are required in gram quantities daily. Deficiencies in micronutrient intake commonly result in malnutrition. In ecosystems, micronutrients most commonly take the form of trace elements such as iron, strontium, and manganese. Micronutrient abundance in the environment greatly influences biogeochemical cycles at the microbial level which large ecological communities rely on to survive. For example, marine primary producers are reliant upon bioavailable dissolved iron for photosyn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiological Plant Disorders
Physiological plant disorders are caused by non-pathological conditions such as poor light, adverse weather, water-logging, Phytotoxicity, phytotoxic compounds or a lack of nutrients, and affect the functioning of the plant system. Physiological disorders are distinguished from plant diseases caused by pathogens, such as a virus or fungus. While the symptoms of physiological disorders may appear disease-like, they can usually be prevented by altering environmental conditions. However, once a plant shows symptoms of a physiological disorder, it is likely that that season's growth or yield will be reduced. Diagnosis of disorders Diagnosis of the cause of a physiological disorder (or disease) can be difficult, but there are many web-based guides that may assist with this. Examples are: ''Abiotic plant disorders: Symptoms, signs and solutions''; ''Georgia Corn Diagnostic Guide''; ''Diagnosing Plant Problems'' (Kentucky); and ''Diagnosing Plant Problems'' (Virginia). Some general tips ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroenhancement
Neuroenhancement or cognitive enhancement is the experimental use of pharmacological or non-pharmacological methods intended to improve cognitive and affective abilities in healthy people who don't have any mental illness. Agents or methods of neuroenhancement are intended to affect cognitive, social, psychological, mood, or motor benefits beyond normal functioning. Pharmacological neuroenhancement agents may include compounds thought to be nootropics, such as modafinil, caffeine, and other drugs used for treating people with neurological disorders. Non-pharmacological measures of cognitive enhancement may include behavioral methods (activities, techniques, and changes), non-invasive brain stimulation, which has been used with the intent to improve cognitive and affective functions, and brain-machine interfaces. Potential agents There are many supposed nootropics, most having only small effect sizes in healthy individuals. Neuroenhancement's most common pharmacological agent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dietary Supplement
A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources, or that are synthetic (to increase the quantity of their consumption). The classes of nutrient compounds in supplements include vitamins, Dietary mineral, minerals, Dietary fiber, fiber, fatty acids, and amino acids. Dietary supplements can also contain substances that have not been confirmed as being essential to life, and so are not ''nutrients'' per se, but are marketed as having a beneficial biological effect, such as plant pigments or polyphenols. Animals can also be a source of supplement ingredients, such as collagen from chickens or fish for example. These are also sold individually and in combination, and may be combined with nutrient ingredients. The European Commission has also established harmonize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
