78 résultats pour "braine"

• Nervous System.

  of paralysis and other neurologic complications. Some diseases exhibit peculiar geographic and age distribution. In temperate zones, multiple sclerosis is a commondegenerative disease of the nervous system, but it is rare in the Tropics. The nervous system is subject to infection by a great variety of bacteria, parasites, and viruses. For example, meningitis, or infection of the meninges investing thebrain and spinal cord, can be caused by many different agents. On the other hand, one specific v...

• Stem Cell.

  The medical profession used adult stem cells to treat diseases long before anyone isolated one. In 1968 scientists performed the first successful bone marrowtransplant, a procedure in which a patient receives an infusion of healthy bone marrow cells. The purpose of such transplants is to restore the blood-making capabilitiesof the patient’s diseased bone marrow after extremely strong chemotherapy has destroyed that bone marrow. From the beginning investigators suspected that stemcells in the inf...

• Heart.

  situation. A Cardiac Cycle Although the right and left halves of the heart are separate, they both contract in unison, producing a single heartbeat. The sequence of events from the beginning ofone heartbeat to the beginning of the next is called the cardiac cycle. The cardiac cycle has two phases: diastole, when the heart’s chambers are relaxed, and systole,when the chambers contract to move blood. During the systolic phase, the atria contract first, followed by contraction of the ventricles. T...

• Atificiel

  Sustainability 2019,11 , 189 2 of 24Since the 1980s, many research was conducted to minimize the error of prediction through a method dubbed as gradient descent. This method is referred to as a Backpropagation algorithm for the training of the ANNs and it was applied to solve problems in different domains using few hidden layers [ 5,6]. Today, the availability of data has introduced the concept of machine learning as a subcategory to AI. Machine learning implies coding the computers to behave l...

• Metabolism (chemistry) - biology.

  nearly perfect balance. Although much remains to be revealed about metabolic processes, biochemists now agree that regulatory, or rate-limiting, enzymes figure largely in the reactionsinvolved ( see Enzyme). Affecting metabolic pathways at the earliest steps, each enzyme molecule has a specific, or active, site that matches, or “fits,” its particular substrate—the compound with which the enzyme forms a product. The precision with which rate-limiting enzymes and substrates join to set off a parti...

• Aerospace Medicine - astronomy.

  medically as aeroembolism and popularly as the bends, leads to confusion, paralysis, or neurocirculatory collapse. The most characteristic symptoms of the bends arepain in the large joints resulting from pressure of the gas on tendons and nerves, together with spasm of the blood vessels. Preflight inhalation of pure oxygen toeliminate nitrogen from the system has proved valuable as a preventive measure. Rapid decompression, resulting from accidental failure at high altitudes of thepressure withi...

• Connecticut Yankee - anthology.

  This missionary knight's name was La Cote Male Taile, and he said that this castle was the abode of Morgan le Fay, sister of King Arthur, and wife of King Uriens,monarch of a realm about as big as the District of Columbia—you could stand in the middle of it and throw bricks into the next kingdom. “Kings” and “Kingdoms”were as thick in Britain as they had been in little Palestine in Joshua's time, when people had to sleep with their knees pulled up because they couldn't stretch outwithout a passp...

• Leukemia.

  leukemia, and normal or mildly decreased in chronic lymphocytic leukemia. Nearly all chronic leukemia patients have increased white cell counts. In chronic myelocyticleukemia, some of these leukemic white cells are capable of functioning as normal cells do by fighting infectious microbes. Hence, infection is no more common than in ahealthy individual. In chronic lymphocytic leukemia the blood contains large numbers of malignant lymphocytes that do not function normally. Normal lymphocytescoexist...

• Stress (psychology).

  blood flow is diverted from the internal organs and skin to the brain and muscles. Breathing speeds up, the pupils dilate, and perspiration increases. This reaction issometimes called the fight-or-flight response because it energizes the body to either confront or flee from a threat. Another part of the stress response involves the hypothalamus and the pituitary gland, parts of the brain that are important in regulating hormones and many otherbodily functions. In times of stress, the hypothal...

• Spider (arthropod) - biology.

  The spider’s abdomen is soft and saclike. On the underside of the tip of the abdomen are three pairs of spinnerets. Each spinneret is studded with many fine, hairliketubes called spigots, which produce a variety of silk threads. The spigots lead to several large silk glands inside the abdomen. Silk is formed as a liquid inside theseabdominal glands. As the silk is drawn out through the spigots, protein molecules within the silk line up parallel to one another, causing the silk to harden and form...

• Beetle - biology.

  cut, or crush prey. Beetles that consume nectar from flowers use tubelike mouthparts to suck up nectar like a primitive straw. C Thorax The thorax, the body region behind the head, consists of three segments that provide attachments for the legs and wings. Each segment of the thorax carries a pair oflegs. The middle segment also bears the stiff wing sheaths called elytra, and the hind segment holds the membranous hind wings. D Legs Beetles have six jointed legs, each leg with five parts. The f...

• Stone Age.

  limestone, quartzite, and indurated shale. Ground stone tools could be made on a wider range of raw material types, including coarser grained rock such as granite. Flaking produces several different types of stone artifacts, which archaeologists look for at prehistoric sites. The parent pieces of rock from which chips have beendetached are called cores, and the chips that have been removed from cores are called flakes. A flake that has had yet smaller flakes removed from one or more edgesin orde...

• Roosevelt Franklin Delano, 1882-1945, né à Hyde Park (New York), homme d'État américain.

  Complétez votre recherche en consultant : Les corrélats États-Unis - Histoire - Les États-Unis, puissance mondiale - La Seconde Guerre mondiale Les livres guerres mondiales - les trois Grands à Yalta, en Crimée, le 9 février 1945, page 2277, volume 4 Complétez votre recherche en consultant : Les corrélats Amérique du Nord - Histoire - L'Amérique du Nord, du XIXe siècle à nos jours Atlantique (charte de l') brain-trust Byrnes James Francis Churchill (sir Winston) démocrate (parti)...

• migrations de populations.

  population - Les perspectives démographiques Les livres migrations de populations - carte des principaux flux internationaux, page 3198, volume 6 Les migrations alternantes. Dans les grandes agglomérations, la dissociation entre le lieu de résidence et le lieu de travail entraîne des déplacements quotidiens. Ce va-et-vient de centaines de milliers de personnes depuis les banlieues vers le centre des villes est appelé « migrations alternantes » ou encore « mouvements pendulaires ». Ces migr...

• arc en ciel

  · "Adults are always asking little kids what they want to be when they grow up because   they're looking for ideas.” What we can or cannot do, what we consider possible or impossible, is rarely a function of our true   capability. It is more likely a function of our beliefs about who we are. Tony Robbins “ Nobody can go back and start a new beginning, but anyone can start today and make a new ending. ” The difference between school and life? In school, you're taught a lesson and then...

• Multiple Sclerosis.

  slow the progress of the disease. It has become increasingly clear that early treatment is crucial to prevent or delay further damage to the nervous system. There are also treatments for specific symptoms, including corticosteroids (often taken intravenously), that can shorten the duration of an MS attack. Several drugs canrelieve spasticity, fatigue, and bladder problems. People with MS often find that nondrug treatments, such as regular exercise and adequate rest, can help them tomaintain more...

• Autism.

  may also repeat body movements, such as spinning, rocking, or flapping hands. When upset or excited, they may also harm themselves by skin-biting or head-banging. They may also show significant aggression toward other people or inanimateobjects, or may have episodes of extreme anger or frustration. D Associated Symptoms Some children with autism show other symptoms that do not contribute to the diagnosis of autism itself. Sensory sensitivity is quite common, especially to some textures, sounds,...

• Death and Dying - biology.

• Mental Illness.

  note that under this definition, political dissidents could be considered mentally ill for refusing to accept the dictates of their government. VI PREVALENCE Mental illness affects people of all ages, races, cultures, and socioeconomic classes. The prevalence of mental illness refers to how many people experience a mentalillness during a specified time period. A United States and Worldwide In the United States, researchers estimate that about 24 percent of people 18 or older, or about 44 mill...

• Attention-Deficit Hyperactivity Disorder.

  Although the drugs are prescribed most often to treat ADHD among children, increasingly adults are taking the drugs for ADHD. From 2002 to 2005 the number ofprescriptions written for adults reportedly increased by 90 percent. In the United States about 2.5 million children and about 1.5 million adults take ADHD drugs. Amember of the FDA advisory panel noted that adults are more likely to have a higher risk of heart problems. Most of the 25 sudden deaths, however, were amongchildren. The prelimin...

• which became a seed.

  BEAUTIFUL ANDTRUE   Mom made spaghetti fordinner thatnight. Ronatewith us.Iasked himifhe was stillinterested inbuying meafive-piece drum setwith Zildjian cymbals. Hesaid, "Yeah. Ithink thatwould begreat." "Howabout adouble basspedal?" "Idon't know whatthatis,but Ibet wecould arrange it."Iasked himwhy hedidn't havehisown family. Momsaid,"Oskar!" I said, " What? " Ron putdown hisknife andfork andsaid, "It'sOK." Hesaid, "Idid have afamily, Oskar.Ihad awife anda daughter." "Didyougetdivorced?" Helau...

• Development (biology) - biology.

  Understanding the molecular machinery within cells gives biologists a direct basis for understanding growth, because growth is the synthesis of new protoplasm, andbiologists know the basic mechanism of this synthesis. One key gap, however, exists in this knowledge. Biologists want to know not only how substances aresynthesized but also how growth is controlled so that the proportions of an animal or plant remain consistent from generation to generation. The direction and amountof growth, which a...

• Comparative Anatomy.

  In comparing two species, anatomists have to be careful to differentiate between homologous structures, which are ones that have evolved from a shared ancestor, andanalogous structures, which have developed from different origins. Homologous structures are built on the same underlying plan. A human arm, a bat’s wing, and awhale’s flipper look quite different from the outside, but the bones inside reveal that these limbs all have the same basic structure. Analogous structures, by contrast,often l...

• Hormone.

  women is called a follicle-stimulating hormone. When a follicle-stimulating hormone binds to an ovary cell, it stimulates the enzymes needed for the synthesis ofestradiol, a female sex hormone. Another gonadotropin called luteinizing hormone regulates the production of eggs in women and the production of the male sexhormone testosterone. Produced in the male gonads, or testes, testosterone regulates changes to the male body during puberty, influences sexual behavior, and playsa role in growth. T...

• Coral - biology.

  Soft corals lack a distinct skeleton. Although they live in colonies, the individual polyps are fused into a complex body, usually strengthened by small lumps or spikesknown as sclerites, which are made of protein and calcite. Soft corals come in a variety of shapes, including undulating sheets, upright mushroomlike shapes, andbeautiful shapes that form branches. A number of other octocorals have skeletons made from a hard or horny protein, sometimes strengthened with more brittle calcareous dep...

• Consciousness

  view faces several serious objections. Rival views of introspective consciousness fall into three categories, according to whether they treat introspective access (1) as epistemically looser or less direct than inner perception, (2) as tighter or more direct, or (3) as fundamentally non-epistemic or nonrepresentational. Theories in category (1) explain introspection as always retrospective, or as typically based on self-directed theoretical inferences. Rivals from category (2) maintain that an i...

• Midnighters

• Ant - biology.

  The workers of many ant species carry a stinger within the hind end of the gaster. These ants use the stinger to defend against their enemies. In some species, workerants lack a stinger but use the tip of their gaster to squirt or dab poison at other small animals and when fighting battles with other ants, fending off predators, or killinginsects or other animals that they use as food. III PHYSIOLOGY Ants have a rigid, external skeleton called an exoskeleton that gives the soft, inner body its...