Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. Anorexia is a term of Greek origin: an- (ἀν-, prefix denoting negation) and orexis (ὄρεξις, "appetite"), translating literally to "a loss of appetite"; instead, the adjective nervosa indicates the functional and non-organic nature of the disorder. Anorexia nervosa was coined by Gull in 1873 but, despite literal translation, the symptom of hunger is frequently present and the pathological control of this instinct is a source of satisfaction for the patients.
Patients with anorexia nervosa commonly see themselves as overweight, although they are in fact underweight. The DSM-5 describes this perceptual symptom as "disturbance in the way in which one's body weight or shape is experienced". In research and clinical settings, this symptom is called "body image disturbance". Patients with anorexia nervosa also often deny that they have a problem with low weight. They may weigh themselves frequently, eat small amounts, and only eat certain foods. Some exercise excessively, force themselves to vomit (in the "anorexia purging" subtype), or use laxatives to lose weight and control body shapes. Medical complications may include osteoporosis, infertility, and heart damage, among others. Women will often stop having menstrual periods. In extreme cases, patients with anorexia nervosa who continually refuse significant dietary intake and weight restoration interventions, and are declared incompetent to make decisions by a psychiatrist, may be fed by force under restraint via nasogastric tube after asking their parents or proxies to make the decision for them.The cause of anorexia is currently unknown. There appear to be some genetic components with identical twins more often affected than fraternal twins. Cultural factors also appear to play a role, with societies that value thinness having higher rates of the disease. Additionally, it occurs more commonly among those involved in activities that value thinness, such as high-level athletics, modeling, and dancing. Anorexia often begins following a major life-change or stress-inducing event. The diagnosis requires a significantly low weight and the severity of disease is based on body mass index (BMI) in adults with mild disease having a BMI of greater than 17, moderate a BMI of 16 to 17, severe a BMI of 15 to 16, and extreme a BMI less than 15. In children, a BMI for age percentile of less than the 5th percentile is often used.Treatment of anorexia involves restoring the patient back to a healthy weight, treating their underlying psychological problems, and addressing behaviors that promote the problem. While medications do not help with weight gain, they may be used to help with associated anxiety or depression. Different therapy methods may be useful, such as cognitive behavioral therapy or an approach where parents assume responsibility for feeding their child, known as Maudsley family therapy. Sometimes people require admission to a hospital to restore weight. Evidence for benefit from nasogastric tube feeding is unclear; such an intervention may be highly distressing for both anorexia patients and healthcare staff when administered against the patient's will under restraint. Some people with anorexia will have a single episode and recover while others may have recurring episodes over years. Many complications improve or resolve with the regaining of weight.Globally, anorexia is estimated to affect 2.9 million people as of 2015. It is estimated to occur in 0.9% to 4.3% of women and 0.2% to 0.3% of men in Western countries at some point in their life. About 0.4% of young women are affected in a given year and it is estimated to occur ten times more commonly among women than men. Rates in most of the developing world are unclear. Often it begins during the teen years or young adulthood. While anorexia became more commonly diagnosed during the 20th century it is unclear if this was due to an increase in its frequency or simply better diagnosis. In 2013, it directly resulted in about 600 deaths globally, up from 400 deaths in 1990. Eating disorders also increase a person's risk of death from a wide range of other causes, including suicide. About 5% of people with anorexia die from complications over a ten-year period, a nearly six times increased risk. The term "anorexia nervosa" was first used in 1873 by William Gull to describe this condition.
In recent years, evolutionary psychiatry as an emerging scientific discipline has been studying mental disorders from an evolutionary perspective. It is still debated whether eating disorders such as anorexia have evolutionary functions or if they are problems resulting from a modern lifestyle.Affect may refer to:
Affect (education)
Affect (linguistics), attitude or emotion that a speaker brings to an utterance
Affect (philosophy)
Affect (psychology), the experience of feeling or emotion
Affect display, signs of emotion, such as facial expression, vocalization, and posture
Affect theory
Affective science, the scientific study of emotion
Affective computing, an area of research in computer science aiming to understand the emotional state of users
Reduced affect display, a.k.a. emotional blunting or affective flattening, a reduction in emotional reactivity
Pseudobulbar affect, a.k.a. labile affect, the unstable display of emotion
Affect (rhetoric), the responsive, emotional feeling that precedes cognition
Affected accent; see Accent (sociolinguistics)
Affect (company), a defunct Japanese video game developerA planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and – according to the International Astronomical Union but not all planetary scientists – has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, astrology, science, mythology, and religion. Apart from Earth itself, five planets in the Solar System are often visible to the naked eye. These were regarded by many early cultures as divine, or as emissaries of deities. As scientific knowledge advanced, human perception of the planets changed, incorporating a number of disparate objects. In 2006, the International Astronomical Union (IAU) officially adopted a resolution defining planets within the Solar System. This definition is controversial because it excludes many objects of planetary mass based on where or what they orbit. Although eight of the planetary bodies discovered before 1950 remain "planets" under the current definition, some celestial bodies, such as Ceres, Pallas, Juno and Vesta (each an object in the solar asteroid belt), and Pluto (the first trans-Neptunian object discovered), that were once considered planets by the scientific community, are no longer viewed as planets under the current definition of planet.
The planets were thought by Ptolemy to orbit Earth in deferent and epicycle motions. Although the idea that the planets orbited the Sun had been suggested many times, it was not until the 17th century that this view was supported by evidence from the first telescopic astronomical observations, performed by Galileo Galilei. About the same time, by careful analysis of pre-telescopic observational data collected by Tycho Brahe, Johannes Kepler found the planets' orbits were elliptical rather than circular. As observational tools improved, astronomers saw that, like Earth, each of the planets rotated around an axis tilted with respect to its orbital pole, and some shared such features as ice caps and seasons. Since the dawn of the Space Age, close observation by space probes has found that Earth and the other planets share characteristics such as volcanism, hurricanes, tectonics, and even hydrology.
Planets in the Solar System are divided into two main types: large low-density giant planets, and smaller rocky terrestrials. There are eight planets in the Solar System according to the IAU definition. In order of increasing distance from the Sun, they are the four terrestrials, Mercury, Venus, Earth, and Mars, then the four giant planets, Jupiter, Saturn, Uranus, and Neptune. Six of the planets are orbited by one or more natural satellites, the two exceptions being Mercury and Venus.
Several thousands of planets around other stars ("extrasolar planets" or "exoplanets") have been discovered in the Milky Way. As of 1 September 2021, 4,834 known extrasolar planets in 3,572 planetary systems (including 795 multiple planetary systems), ranging in size from just above the size of the Moon to gas giants about twice as large as Jupiter, have been discovered, out of which more than 100 planets are the same size as Earth, nine of which are at the same relative distance from their star as Earth from the Sun, i.e. in the circumstellar habitable zone. On 20 December 2011, the Kepler Space Telescope team reported the discovery of the first Earth-sized extrasolar planets, Kepler-20e and Kepler-20f, orbiting a Sun-like star, Kepler-20. A 2012 study, analyzing gravitational microlensing data, estimates an average of at least 1.6 bound planets for every star in the Milky Way.
Around one in five Sun-like stars is thought to have an Earth-sized planet in its habitable zone.Prevention may refer to:
| תאריך המענק | 2018 |
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| שפה מקורית | ???core.languages.en_GB??? |
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