Science & Philosophy: Anticolonialism in Southeast Asia - Categories And Features Of Anticolonialism to Ascorbic acid

Science Encyclopedia

Anticolonialism in Southeast Asia - Categories And Features Of Anticolonialism, Colonial Origins Of The Idea, Nationalism And The Idea Of Anticolonialism

Anticolonialism in Southeast Asia has been considered from a wide range of perspectives, resulting in deliberation over its character and place in the region's history. Generally, anti-colonialism refers to one type of Southeast Asian response to the encounter with Euro-American colonialism. One might then describe anticolonialism as including everything from the personalities, institutions…

1 minute read

Anticonvulsants

Anticonvulsants are drugs designed to prevent the seizures or convulsions typical of epilepsy or other convulsant disorders. Epilepsy is not a single disease—it is a set of symptoms that may have different causes in different people. There is an imbalance in the brain's electrical activity, which causes seizures. These may affect part or all of the body and may or may not cause a los…

4 minute read

Antidepressant Drugs - Description, Precautions - Recommended dosage, Side effects, Interactions

Antidepressant drugs are used to treat serious, continuing mental depression that interferes with a person's ability to function. Everyone feels sad, "blue," or discouraged occasionally, but usually those feelings do not interfere with everyday life and do not need treatment. However, when the feelings become overwhelming and last for weeks or months, professional treatment ca…

3 minute read

Antihelmintics

Antihelmintics are drugs used to kill parasitic worms (from the Greek word helmins, worm). These preparations are also called vermicides. Worm infestations are among the most common parasitic diseases of man. Often the life cycle of the worm begins when a child playing in dirt ingests the eggs of the worm. The egg hatches in the child's digestive tract and the worms begin their unending que…

1 minute read

Antihistamines - Recommended Dosage, Precautions, Side Effects, Interactions - Special conditions

Antihistamines are medicines that relieve or prevent the symptoms of hay fever and other kinds of allergy. An allergy is a condition in which the body becomes unusually sensitive to some substance, such as pollen, mold spores, dust particles, certain foods, or medicines. These substances, known as allergens, cause no unusual reactions in most people. But in people who are sensitive to them, exposu…

2 minute read

Antimatter

Antimatter is matter comprising particles that are equal in mass to the particles comprising ordinary matter—neutrons, protons, electrons, and so forth—but with opposite electrical properties. An antiproton has the same mass as the proton, but negative charge, an antielectron (positron) has the same mass as an electron, but negative charge, and an antineutron has the same mass as a n…

4 minute read

Antimetabolites

Antimetabolites are substances that interfere with the normal metabolism of an organism, thereby causing its death. They are widely used in the medical sciences because they have the ability to kill or inactivate microorganisms that cause disease. Terms such as antibacterials, antifungals, and antivirals are used to describe antimetabolites that act on bacteria, fungi, and viruses, respectively. I…

1 minute read

Antioxidants - Vitamins As Antioxidants, The Vitamins, Current Research On Antioxidants

Antioxidants are molecules that prevent or slow down the breakdown of other substances by oxygen. In biology, antioxidants are scavengers of small, reactive molecules known as free radicals and include intracellular enzymes such as superoxide dismutase (SOD), catalase and glutathione peroxidase. Antioxidants can also be extracellular originating as exogenous cofactors such as vitamins. Nutrients f…

3 minute read

Antiparticle - Dirac's Hypothesis, Other Antiparticles, Antimatter, Antiparticles And Cosmology

An antiparticle is a subatomic particle identical with more familiar subatomic particles such as electrons or protons, but with the opposite electrical charge or, in the case of uncharged particles, the opposite magnetic moment. For example, an antielectron (also known as a positron) is identical with the more familiar electron, except that the former carries a single unit of positive electrical c…

less than 1 minute read

Antipsychotic Drugs

An antipsychotic drug, sometimes called a neuroleptic, is a prescription medication used to treat psychosis. Psychosis is a major psychiatric disorder characterized by derangement or disorganization of personality and/or by the inability to tell what is real from what is not real, often with hallucinations, delusions, and thought disorders. People who are psychotic often have a difficult time comm…

4 minute read

Antisepsis - The search for antiseptics

Antisepsis is the prevention or inhibition of an infection by either killing the organism responsible for the infection, or weakening the organism so that it is unable to cause the infection or survive. This is usually achieved by application of an antiseptic or germicidal preparation. An antiseptic differs from an antibiotic. An antibiotic is specifically directed to a target bacterium or differe…

4 minute read

Antlions

Antlions or doodlebugs are insects best known by their larvae, which have small, fat bodies with a huge sickle-shaped pair of mandibles. Antlions belong to the family Myrmeleonidae, of the order Neuroptera, which also includes the lacewings. Members of this order are named for the delicate venation on the wings of the adult, but most people are probably more familiar with the larval stage of antli…

1 minute read

Ants - Mating, Reproduction, And Life Span, Labor Management, Defense And Offense, Communication, Ants And The Ecosystem - development Social structure and behavior

Ants are insects in the family Formicidae in the order Hymenoptera, which also includes bees and wasps. The body of ants is divided into three sections: head, thorax, and abdomen. The head bears two long, flexible antennae (for touch and chemical detection), two eyes, and a pair of powerful mandibles (jaws) for feeding and defense. Ants have three pairs of long legs that end with a claw. They are …

1 minute read

Anxiety

Anxiety is an unpleasant emotional state characterized by an often vague apprehension, uneasiness, or dread. Anxiety is often accompanied by physical sensations similar to those of fear such as perspiration, tightness of the chest, difficulty breathing or breathlessness, dry mouth, and headache. Unlike fear, in which the individual is usually aware of its cause, the cause of anxiety is often not c…

4 minute read

Apgar Score

Apgar score is the assessment of a newborn baby's physical condition based on skin color, heart rate, response to stimulation, muscle tone, and respiratory effort. Each criteria is rated from zero to two with a total score of 10 signifying the best possible physical condition. The assessment determines the need for immediate emergency treatment, helps prevent unnecessary emergency intervent…

2 minute read

Aphasia

Aphasia is a disorder caused by damage to the areas of the brain that direct the ability to speak, interpret, and understand language. Usually, aphasia is caused by a head injury, a brain tumor, a stroke, or a serious infection. In adults, one of the most common causes of aphasia is a cerebrovascular accident—a stroke. A stroke occurs when the blood and oxygen supply to the brain is blocked…

1 minute read

Approximation

In mathematics, making an approximation is the act or process of finding a number acceptably close to an exact value; that number is then called an approximation or approximate value. Approximating has always been an important process in the experimental sciences and engineering, in part because it is impossible to make perfectly accurate measurements. Approximation also arises because some number…

2 minute read

Apraxia

Apraxia is a disorder of brain function in which a person is unable to perform learned motor acts even though the physical ability exists and the desire to perform them is there. Brain damage to the parietal lobes, particularly in the dominant hemisphere, results in apraxia. Unlike paralysis, movements remain intact but The area of the brain associated with apraxia. Illustration by Hans �…

2 minute read

Aquifer

Although groundwater exists beneath most land surfaces, it is frequently limited in its availability to human users by local hydrogeologic conditions. Those portions of the water-bearing subsurface that are capable, within their hydrogeologic constraints, of yielding significant amounts of that water are called aquifers. Aquifers can store large amounts of water within pore spaces throughout the r…

2 minute read

Arachnids

Arachnids (class Arachnida) form the second largest group of terrestrial arthropods (phylum Arthropoda) with the class Insecta being the most numerous. There are over 70,000 species of arachnids, which include such familiar creatures as scorpions, spiders, harvestmen or daddy longlegs, and ticks and mites, as well as the less common whip scorpions, pseudoscorpions, and sun spiders. Arachnids are m…

4 minute read

Arapaima

The giant of freshwater fishes, the arapaima or pirarucu (Arapaima gigas) is a legend among fish. Weighing up to 440 lb (200 kg), this species, which has only been recorded in the rivers of Brazil and the Guianas, may reach a length of some 16.5 ft (5 m), although most specimens today are less than 10 ft (3 m) long. The origins of the arapaima, which belongs to the bony-tongued fishes (Osteoglossi…

2 minute read

Arc

An arc is a segment of a curve, most often a circle. In the strictest definition, an arc is a segment of a curve in a plane. Examples include segments of geometrical forms such as circles, ellipses, and parabolas, as well as irregular arcs defined by analytical functions. Arcs of circles can be classified by size. A minor arc is one whose length is shorter than one-half of the circumference of a c…

1 minute read

Arc Lamp

Long before the incandescent electric light bulb was invented, arc lamps had given birth to the science of electric lighting. In the early 1800s, when the first large batteries were being built, researchers noticed that electric current would leap across a gap in a circuit, from one electrode to the other, creating a brilliant light. Sir Humphry Davy is credited with discovering this electric arc …

3 minute read

Archaebacteria - General Characteristics, Groups Of Archaebacteria

Life on Earth can divided into three large collections, or domains. These are the Eubacteria (or "true" bacteria), Eukaryota (the domain that humans belong to), and Archae. The members of this last domain are the archaebacteria. Most archaebacteria (also called archae) look bacteria-like when viewed under the microscope. They have features that are quite different, however, from both…

less than 1 minute read

Archaeogenetics

By applying modern genetics to population studies, archaeology, and anthropology, scientists are forming a new interpretation of prehistoric migrations. The initial peopling of Europe, Asia, and the Americas is usually explained by basic theories that appeal to reason. For example, scientists consider that groups of prehistoric peoples would periodically migrate into North America via a land bridg…

4 minute read

Archaeology - Background, Disciplines, Current Controversy - Field methods

The term archaeology refers, in part, to the study of human culture and of cultural changes that occur over time. In practice, archaeologists attempt to logically reconstruct human activities of the past by systematically recovering and examining artifacts or objects of human origin. However, archaeology is a multi-faceted scientific pursuit, and includes various specialized disciplines and subfie…

9 minute read

Archaeometallurgy

Archaeometallurgy is the study of metal artifacts, the technology that was used to smelt them, and the ways ancient societies acquired ores. In addition to understanding the history of metal technology, archaeometallurgists seek to learn more about the people who made and used metal implements and gain a broader understanding of the economic and social contexts in which the people lived. Archaeome…

1 minute read

Archeological Mapping - Spatial mapping and stratigraphic mapping

Before any excavation is begun at a site, the archeologist must prepare a survey map of the site. Site mapping may be as simple as a sketch of the site boundaries, or as complex as a topographic map complete with details about vegetation, artifacts, structures, and features on the site. By recording the presence of artifacts on the site, the site map may reveal information about the way the site w…

5 minute read

Archeological Sites - Cultural Formation, Environmental Formation, Finding An Archeological Site

Archeologists are concerned with the activities of people and nature that create evidence of a cultural past. Such evidence, which may include any remnant of human habitation, is referred to as the archeological record. The processes that produce this evidence are called formation processes. There are two types of formation processes: cultural and environmental. Cultural formation processes are th…

5 minute read

Architecture - Overview - Early Humans In Europe, Antiquity: Egypt, Greece, Rome, Middle Ages, Modern Era

Architecture is the crystallization of ideas. Architecture has been defined many ways—as shelter in the form of art, as a blossoming in stone and a flowering of geometry (Ralph Waldo Emerson), as frozen music (Johann Wolfgang von Goethe), man's triumph over gravitation and his will to power (Friedrich Nietzsche), the will of an epoch translated into space (architect Mies van der Rohe…

2 minute read

Arrow Worms

Arrow worms are small marine planktonic animals of the phylum Chaetognatha found in tropical seas. Most of The anatomy of an arrow worm. Illustration by Hans & Cassidy. Courtesy of Gale Group. the 50 species of arrow worms belong to the genus Sagitta. Arrow worms have a head with eyes and hook-like spines on their jaws that identify them as predators of smaller planktonic a…

1 minute read

Arrowgrass

The arrowgrass family (Juncaginaceae) is a family of herbaceous plants whose leaves are grass-like and shaped somewhat like an arrowhead. The arrowgrass family has four genera: Scheuchzeria with two species; Thrighlochin with 12 species; Maundia with one species; and Tetroncium with one species. All species in the arrowgrass family grow in wet or moist habitats in temperate and cold regions of the…

1 minute read

Arrowroot

Arrowroot is an edible starch obtained from the underground stems, or rhizomes, of several species of the genus Maranta, family Marantaceae. The most common species of arrowroot is Maranta arundinacea, native to the tropical areas of Florida and the West Indies, and called true, Bermuda, or West Indian arrowroot. Several relatives of true arrowroot are also known locally as arrowroot and have root…

1 minute read

Arteries

Arteries are blood vessels that transport oxygenated blood from the heart to other organs and systems throughout the body. In humans, healthy arteries are smooth, elastic structures, while diseased arteries may contain bulges due to high blood pressure, hard, inelastic areas, or internal blockages resulting from the accumulation of fatty plaques circulating in the blood. Atherosclerosis is the har…

3 minute read

Arteriosclerosis - The Cause Of Atherosclerosis, How Plaques Form, Diagnosis And Treatment, Prevention

Arteriosclerosis literally means "hardening of the arteries." As people age, their blood vessel walls naturally grow a bit stiffer and harder, with less flexibility. A common complication of arteriosclerosis is called atherosclerosis. In this condition, plaques (hardened masses composed of lipids, dead cells, fibrous tissue, and platelets) collect in the arteries. If a plaque grows l…

1 minute read

Arthritis

Arthritis is a term that refers to the inflammation of joints (the point where the ends of two bones meet each other). Upwards of 43 million American adults and children (1 out of every 6 citizens) have some form of the more than 100 different types of arthritis. Inflammation is a reaction of the body to injury. Excess fluid is directed to the affected area, which produces swelling. The fluid is m…

4 minute read

Arthropods

Arthropods are invertebrates such as insects, spiders and other arachnids, and crustaceans that comprise the phylum Arthropoda. The phylum Arthropoda includes three major classes—the Insecta, Arachnida, and Crustacea. Arthropods are characterized by their external skeleton, or exoskeleton, made mostly of chitin, a complex, rigid carbohydrate usually covered by a waxy, waterproof cuticle. Th…

2 minute read

Arthroscopic Surgery - Benefits Of Arthroscopic Surgery, Development Of The Procedure, The Operation, Types Of Arthroscopic Surgery

Arthroscopic surgery is a type of orthopedic surgery that utilizes an instrument called an arthroscope. An arthroscope is a small fiber-optic device that allows the surgeon to view the inside of a joint without a large incision. Most arthroscopic surgery can be performed requiring only three small incisions, each about 0.25 in (6 mm) long. These incisions are called portals. The word arthroscope i…

less than 1 minute read

Artifacts and Artifact Classification - Artifact classification

Artifacts are often the most intriguing part of archaeological research. Whether priceless or common, artifacts are key to deciphering the archaeological record and garnering information about how people lived in the past. However, most of the information from archaeological excavation is gathered from an artifact's context, or where an artifact is found, and with what other items it is rec…

6 minute read

Artificial Fibers - Polymeric fibers, Other synthetic fibers

Most synthetic fibers are polymer-based, and are produced by a process known as spinning. This process involves extrusion of a polymeric liquid through fine holes known as spinnerets. After the liquid has been spun, the resulting fibers are oriented by stretching or drawing. This increases the polymeric chain orientation and degree of crystallinity, and has the effect of increasing the modulus and…

17 minute read

Artificial Heart and Heart Valve

An artificial heart is a manmade device that is intended to replace the heart muscle that pumps approximately 2,000 gal (7,571 L) of blood through the body each day. The heart muscle is composed of several chambers and the blood flow into and out of the chambers is controlled by a system of valves. Valve failure can lead to congestive heart failure, pulmonary edema, and other serious cardiovascula…

5 minute read

Artificial Intelligence - What Is Intelligence?, Overview Of Ai, General Problem Solving, Expert Systems, Natural Language Processing

Certain tasks can be performed faster and more accurately by traditionally programmed computers than by human beings, particularly numerical computation and the storage, retrieval, and sorting of large quantities of information. However, the ability of computers to interact flexibly with the real world—their "intelligence"—remains slight. Artificial intelligence (AI) is…

2 minute read

Arum Family (Araceae)

Arums, also called aroids, are flowering plants in the family Araceae. The 2,500 species of arums are distributed worldwide, primarily in tropical and subtropical regions, where they grow in rainforests, mostly on the ground but also commonly as epiphytes. Arums are generally absent from the arctic and deserts. Only 11 species occur in North America and other north temperate regions. Most species …

5 minute read

Asbestos - Classification And Properties, Occurrence And Mining, Uses, Health Considerations

Asbestos is the general name for a wide variety of silicate minerals, mostly silicates of calcium, magnesium, and iron. Their common characteristics are a fibrous structure and resistance to fire. The two most common families of asbestos minerals are called amphibole and serpentine. The mineral has been known and used by humans for centuries. The ancient Romans, for example, wove asbestos wicks fo…

1 minute read

Asceticism - Hindu and Buddhist Asceticism - Asceticism In Hinduism, Asceticism In Buddhism, Asceticism In Jainism, Conclusion, Bibliography

The English term asceticism derives from the Greek askesis, originally meaning "to train" or "to exercise," specifically in the sense of the training and self-denial that an athlete undergoes to attain physical skill and mastery over the body. The Stoics adapted the word to refer to the moral discipline of the sage who learns, through self-mastery, how to act freely…

3 minute read

Asceticism - Western Asceticism - The Ancients, Early Christianity, The Middle Ages, The Early Modern Period, Modernity, Conclusion

Asceticism, defined for our purposes within the context of the premodern tradition, refers to specific passive and active practices that are engaged in out of ideological motives: on the one hand, abstinence from nourishment, sleep, sexuality, social communication, and social ties—thus from natural human expression—and from other components of civilization, such as bodily cleanliness…

less than 1 minute read