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Topic Review

Geography and Cartography in Medieval Islam

Medieval Islamic geography and cartography refer to the study of geography and cartography in the Muslim world during the Islamic Golden Age (variously dated between the 8th century and 16th century). Muslim scholars made advances to the mapmaking traditions of earlier cultures, particularly the Hellenistic geographers Ptolemy and Marinus of Tyre,:193 combined with what explorers and merchants learned in their travels across the Old World (Afro-Eurasia). Islamic geography had three major fields: exploration and navigation, physical geography, and cartography and mathematical geography. Islamic geography reached its apex with Muhammad al-Idrisi in the 12th century.

9.6K
26 Oct 2022

Topic Review

Nutritional Deficiencies Associated with Obesity

Obesity is a critical medical condition worldwide that is increasingly involved with nutritional derangements associated with micronutrient deficiencies, including iron, zinc, calcium, magnesium, selenium, and vitamins A, C, D, and E. Nutritional deficiencies in obesity are mainly caused by poor-quality diets, higher nutrient requirements, alterations in micronutrient metabolism, and invasive obesity treatments. The current conventional agricultural system is designed for intensive food production, focusing on food quantity rather than food quality, consuming excessive agricultural inputs, and producing nutrient-deficient foods, thus generating severe health and environmental problems; agricultural food products may worsen obesity-related malnutrition. Therefore, modern agriculture is adopting new biofortification technologies to combat micronutrient deficiencies and improve agricultural productivity and sustainability.

9.6K
01 Jan 2023

Topic Review

Orgasm (from Greek ὀργασμός, orgasmos; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region characterized by sexual pleasure. Experienced by males and females, orgasms are controlled by the involuntary or autonomic nervous system. They are usually associated with involuntary actions, including muscular spasms in multiple areas of the body, a general euphoric sensation and, frequently, body movements and vocalizations. The period after orgasm (known as the refractory period) is typically a relaxing experience, attributed to the release of the neurohormones oxytocin and prolactin as well as endorphins (or "endogenous morphine"). Human orgasms usually result from physical sexual stimulation of the penis in males (typically accompanying ejaculation) and of the clitoris in females. Sexual stimulation can be by self-practice (masturbation) or with a sex partner (penetrative sex, non-penetrative sex, or other sexual activity). The health effects surrounding the human orgasm are diverse. There are many physiological responses during sexual activity, including a relaxed state created by prolactin, as well as changes in the central nervous system such as a temporary decrease in the metabolic activity of large parts of the cerebral cortex while there is no change or increased metabolic activity in the limbic (i.e., "bordering") areas of the brain. There is also a wide range of sexual dysfunctions, such as anorgasmia. These effects affect cultural views of orgasm, such as the beliefs that orgasm and the frequency or consistency of it are either important or irrelevant for satisfaction in a sexual relationship, and theories about the biological and evolutionary functions of orgasm.

9.6K
30 Nov 2022

Topic Review

Structure and Physiological Activities of Anthocyanins

Anthocyanidin is a kind of water-soluble natural pigment that widely exists in natural plants. Like other natural flavonoids, anthocyanin has a C6-C3-C6 carbon skeleton. Due to the different carbon substituents (-OH, -OCH3) on the B ring, different types of anthocyanins were derived. The six common anthocyanins were Pelargonidin (Pg), Cyanidin (Cy), Delphinidin (Dp), Peonidin (Pn), Petunidin (Pt), and Malvidin (Mv). In addition to giving food a variety of bright colors, anthocyanin also has important biological activities, such as antioxidant, anti-inflammatory, and anti-aging effects, among others. A large number of studies have shown that dietary anthocyanins have a good preventive effect on cardiovascular diseases.

9.6K
01 Aug 2022

Topic Review

Domestic Violence

Domestic violence (also called domestic abuse or family violence) is violence or other abuse that occurs in a domestic setting, such as in a marriage or cohabitation. Domestic violence is often used as a synonym for intimate partner violence, which is committed by one of the people in an intimate relationship against the other person, and can take place in relationships or between former spouses or partners. In its broadest sense, domestic violence also involves violence against children, parents, or the elderly. It can assume multiple forms, including physical, verbal, emotional, economic, religious, reproductive, or sexual abuse. It can range from subtle, coercive forms to marital rape and other violent physical abuse, such as choking, beating, female genital mutilation, and acid throwing that may result in disfigurement or death, and includes the use of technology to harass, control, monitor, stalk or hack. Domestic murder includes stoning, bride burning, honor killing, and dowry death, which sometimes involves non-cohabitating family members. Globally, the victims of domestic violence are overwhelmingly women, and women tend to experience more severe forms of violence. They are also likelier than men to use intimate partner violence in self-defense. In some countries, domestic violence may be seen as justified or legally permitted, particularly in cases of actual or suspected infidelity on the part of the woman. Research has established that there exists a direct and significant correlation between a country's level of gender equality and rates of domestic violence, where countries with less gender equality experience higher rates of domestic violence. Domestic violence is among the most underreported crimes worldwide for both men and women. In addition, due to social stigmas regarding male victimization, men who are victims of domestic violence face an increased likelihood of being overlooked by healthcare providers. Domestic violence often occurs when the abuser believes that they are entitled to it, or that it is acceptable, justified, or unlikely to be reported. It may produce an intergenerational cycle of violence in children and other family members, who may feel that such violence is acceptable or condoned. Many people do not recognize themselves as abusers or victims, because they may consider their experiences as family conflicts that had gotten out of control. Awareness, perception, definition and documentation of domestic violence differs widely from country to country. Additionally, domestic violence often happens in the context of forced or child marriages. In abusive relationships, there may be a cycle of abuse during which tensions rise and an act of violence is committed, followed by a period of reconciliation and calm. The victims may be trapped in domestically violent situations through isolation, power and control, traumatic bonding to the abuser, cultural acceptance, lack of financial resources, fear, and shame, or to protect children. As a result of abuse, victims may experience physical disabilities, dysregulated aggression, chronic health problems, mental illness, limited finances, and a poor ability to create healthy relationships. Victims may experience severe psychological disorders, such as post-traumatic stress disorder (PTSD). Children who live in a household with violence often show psychological problems from an early age, such as avoidance, hypervigilance to threats and dysregulated aggression, which may contribute to vicarious traumatization.

9.6K
21 Oct 2022

Topic Review

Hyaluronic Acid

Hyaluronic acid, as a natural linear polysaccharide, has attracted researchers’ attention from its initial detection and isolation from tissues in 1934 until the present day. Due to biocompatibility and a high biodegradation of hyaluronic acid, it finds wide application in bioengineering and biomedicine: from biorevitalizing skin cosmetics and endoprostheses of joint fluid to polymeric scaffolds and wound dressings. However, the main properties of aqueous polysaccharide solutions with different molecular weights are different. Moreover, the therapeutic effect of hyaluronic acid-based preparations directly depends on the molecular weight of the biopolymer. The present entry collects the information about hyaluronic acid and its original properties. Particular emphasis is placed on the structural, physical and physico-chemical properties of hyaluronic acid in water solutions, as well as their degradability.

9.5K
31 Aug 2020

Topic Review

List of Artifacts in Biblical Archaeology

The following is a list of artifacts—objects created or modified by human culture—that are significant to biblical archaeology.

9.5K
31 Oct 2022

Topic Review

School Strike for the Climate

The school strike for the climate (Swedish: Skolstrejk för klimatet), also known variously as Fridays for Future (FFF), Youth for Climate, Climate Strike or Youth Strike for Climate, is an international movement of school students who take time off from class on Fridays to participate in demonstrations to demand action from political leaders to take action to prevent climate change and for the fossil fuel industry to transition to renewable energy. Publicity and widespread organising began after Swedish schoolgirl Greta Thunberg staged a protest in August 2018 outside the Swedish Riksdag (parliament), holding a sign that read "Skolstrejk för klimatet" ("School strike for the climate"). A global strike on 15 March 2019 gathered more than one million strikers. Around 2200 strikes were organised in 125 countries. On 24 May 2019, the second global strike took place, in which 1600 events across 150 countries drew hundreds of thousands of protesters. The events were timed to coincide with the 2019 European Parliament election. The 2019 Global Week for Future was a series of 4500 strikes across over 150 countries, focused around Friday 20 September and Friday 27 September. Likely the largest climate strikes in world history, 20 September strikes gathered roughly 4 million protesters, many of them schoolchildren, including 1.4 million people on strike in Germany. On 27 September, an estimated 2 million people participated in demonstrations worldwide, including over 1 million protesters in Italy and several hundred thousand protesters in Canada.

9.5K
06 Dec 2022

Topic Review

Annulment is a legal procedure within secular and religious legal systems for declaring a marriage null and void. Unlike divorce, it is usually retroactive, meaning that an annulled marriage is considered to be invalid from the beginning almost as if it had never taken place (though some jurisdictions provide that the marriage is only void from the date of the annulment; for example, this is the case in section 12 of the Matrimonial Causes Act 1973 in England and Wales). In legal terminology, an annulment makes a void marriage or a voidable marriage null.

9.5K
04 Nov 2022

Topic Review

Quaternary Numeral System

A quaternary /kwəˈtɜːrnəri/ numeral system is base-4. It uses the digits 0, 1, 2 and 3 to represent any real number. Four is the largest number within the subitizing range and one of two numbers that is both a square and a highly composite number (the other being 36), making quaternary a convenient choice for a base at this scale. Despite being twice as large, its radix economy is equal to that of binary. However, it fares no better in the localization of prime numbers (the smallest better base being the primorial base six, senary). Quaternary shares with all fixed-radix numeral systems many properties, such as the ability to represent any real number with a canonical representation (almost unique) and the characteristics of the representations of rational numbers and irrational numbers. See decimal and binary for a discussion of these properties.

9.5K
16 Nov 2022

Topic Review

History of Statistics

The history of statistics in the modern way is that it originates from the term statistics, found in 1749 in Germany. Although there have been changes to the interpretation of the word over time. The development of statistics is intimately connected on the one hand with the development of sovereign states, particularly European states following the peace of Westphalia (1648); and the other hand with the development of probability theory, which put statistics on a firm theoretical basis (see history of probability). In early times, the meaning was restricted to information about states, particularly demographics such as population. This was later extended to include all collections of information of all types, and later still it was extended to include the analysis and interpretation of such data. In modern terms, "statistics" means both sets of collected information, as in national accounts and temperature records, and analytical work which requires statistical inference. Statistical activities are often associated with models expressed using probabilities, hence the connection with probability theory. The large requirements of data processing have made statistics a key application of computing; see history of computing hardware. A number of statistical concepts have an important impact on a wide range of sciences. These include the design of experiments and approaches to statistical inference such as Bayesian inference, each of which can be considered to have their own sequence in the development of the ideas underlying modern statistics.

9.5K
19 Oct 2022

Biography

Erwin Schrödinger

Erwin Rudolf Josef Alexander Schrödinger (UK: /ˈʃrɜːdɪŋər/, US: /ˈʃroʊ-/;[1] German: [ˈɛɐ̯viːn ˈʃʁøːdɪŋɐ]; 12 August 1887 – 4 January 1961), sometimes written as Erwin Schrodinger or Erwin Schroedinger ("oe" is the proper transliteration of the German "ö"), was a Nobel Prize-winning Austrian-Irish physicist who developed a number of fundamental results in quantum theor

9.5K
30 Nov 2022

Topic Review

Hat puzzles are logic problems that date back to as early as 1961. Such hat puzzles, frequently contextualized as prisoners and hats puzzles, are induction puzzles (a kind of logic puzzle) that involve reasoning about the actions of other people, drawing in aspects of Game theory sometimes called the hierarchy of beliefs. There are many variations, but the central theme remains the same. A number of players are each wearing a hat, which may be of various specified colours. Players can see the colours of at least some other players' hats, but not that of their own. With highly restricted communication or none, some of the players must guess the colour of their hat. The problem is to find a strategy for the players to determine the colours of their hats based on the hats they see and what the other players do. In some versions, they compete to be the first to guess correctly; in others, they can work out a strategy beforehand to cooperate and maximize the probability of correct guesses. One variation received some new publicity as a result of Todd Ebert's 1998 Ph.D. thesis at the University of California, Santa Barbara. It is a strategy question about a cooperative game, which has connections to algebraic coding theory.

9.5K
24 Oct 2022

Topic Review

Schizoid Personality Disorder

Schizoid personality disorder (/ˈskɪtsɔɪd, ˈskɪdzɔɪd/, often abbreviated as SPD or SzPD) is a personality disorder characterized by a lack of interest in social relationships, a tendency toward a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment and apathy. Affected individuals may be unable to form intimate attachments to others and simultaneously possess a rich and elaborate but exclusively internal fantasy world. Other associated features include stilted speech, a lack of deriving enjoyment from most activities, feeling as though one is an "observer" rather than a participant in life, an inability to tolerate emotional expectations of others, apparent indifference when praised or criticized, a degree of asexuality, and idiosyncratic moral or political beliefs. Symptoms typically start in late childhood or adolescence. The cause of SPD is uncertain, but there is some evidence of links and shared genetic risk between SPD, other cluster A personality disorders (such as schizotypal personality disorder) and schizophrenia. Thus, SPD is considered to be a "schizophrenia-like personality disorder". It is diagnosed by clinical observation, and it can be very difficult to distinguish SPD from other mental disorders (such as autism spectrum disorder, with which it may sometimes overlap). The effectiveness of psychotherapeutic and pharmacological treatments for the disorder has yet to be empirically and systematically investigated. This is largely because people with SPD rarely seek treatment for their condition. Originally, low doses of atypical antipsychotics were also used to treat some symptoms of SPD, but their use is no longer recommended. The substituted amphetamine bupropion may be used to treat associated anhedonia. However, it is not general practice to treat SPD with medications, other than for the short-term treatment of acute co-occurring disorders (e.g. depression). Talk therapies such as cognitive behavioral therapy (CBT) may not be effective, because people with SPD may have a hard time forming a good working relationship with a therapist. SPD is a poorly studied disorder, and there is little clinical data on SPD because it is rarely encountered in clinical settings. Studies have generally reported a prevalence of less than 1% It is more common in males than in females. SPD is linked to negative outcomes, including a significantly compromised quality of life, reduced overall functioning even after 15 years and one of the lowest levels of "life success" of all personality disorders (measured as "status, wealth and successful relationships"). Bullying is particularly common towards schizoid individuals. Suicide may be a running mental theme for schizoid individuals, though they are not likely to actually attempt it. Some symptoms of SPD (e.g. solitary lifestyle and emotional detachment), however, have been stated as general risk factors for serious suicidal behaviour.

9.5K
20 Oct 2022

Topic Review

Nomadic empires, sometimes also called steppe empires, Central or Inner Asian empires, were the empires erected by the bow-wielding, horse-riding, nomadic people in the Eurasian Steppe, from classical antiquity (Scythia) to the early modern era (Dzungars). They are the most prominent example of non-sedentary polities. Some nomadic empires consolidated by establishing a capital city inside a conquered sedentary state and then exploiting the existing bureaucrats and commercial resources of that non-nomadic society. In such a scenario, the originally nomadic dynasty may become culturally assimilated to the culture of the occupied nation before it is ultimately overthrown. Ibn Khaldun (1332–1406) described a similar cycle on a smaller scale in 1377 in his Asabiyyah theory. Historians of the early medieval period may refer to these polities as "khanates" (after khan, the title of their rulers). After the Mongol conquests of the 13th century the term orda ("horde") also came into use — as in "Golden Horde".

9.5K
25 Nov 2022

Topic Review

Photocatalysts indicates the acceleration of a chemical reaction occurring on the surface of a semiconductor material (the catalyst) caused by the presence of light. Illumination of the catalyst causes the generation of free changes (electrons and holes) that can partecipate to chemical reactions, thus causing (or acceleratin) them. Photocatalysis con be used in hydrogen (H2) production (e.g., via water splitting or photo-reforming of organic substrates), CO2 reduction, pollution mitigation and water or air remediation via oxidation (photodegradation) of pollutants. Titanium dioxide (TiO2) is a “benchmark” photocatalyst, thanks to many favorable characteristics.

9.5K
26 May 2021

Topic Review

Nestorianism is a Christian theological doctrine that upholds several distinctive teachings in the fields of Christology and Mariology. It opposes the concept of hypostatic union and emphasizes a radical distinction between two natures (human and divine) of Jesus Christ. That Christological position is defined as radical dyophisitism. Nestorianism was named after Christian theologian Nestorius (386–450), Patriarch of Constantinople from 428 to 431, who was influenced by Christological teachings of Theodore of Mopsuestia at the School of Antioch. Nestorius' teachings brought him into conflict with other prominent church leaders, most notably Cyril of Alexandria, who criticized especially his rejection of the title Theotokos ("Mother of God") for Mary, the mother of Jesus. Nestorius and his teachings were eventually condemned as heretical at the Council of Ephesus in 431, and again at the Council of Chalcedon in 451, which led to the Nestorian Schism; churches supporting Nestorian teachings broke with the rest of the Christian Church. Following that, many of Nestorius's supporters relocated to the Sasanian Empire, where they affiliated with the local Christian community, known as the Church of the East. Over the next decades the Church of the East became increasingly Nestorian in doctrine, leading to it becoming known alternatively as the Nestorian Church.

9.5K
25 Nov 2022

Topic Review

Iron-Containing Oral Contraceptives

Oral contraceptive use has been associated with decreased menstrual blood losses; thus, can independently reduce the risk of anemia and iron deficiency in women. Manufacturers have recently started to include supplemental iron in the non-hormonal placebo tablets of some contraceptives.

9.5K
15 Jul 2021

Topic Review

Dinosaur Behavior

Dinosaur behavior is difficult for paleontologists to study since much of paleontology is dependent solely on the physical remains of ancient life. However, trace fossils and paleopathology can give insight into dinosaur behavior. Interpretations of dinosaur behavior are generally based on the pose of body fossils and their habitat, computer simulations of their biomechanics, and comparisons with modern animals in similar ecological niches. As such, the current understanding of dinosaur behavior relies on speculation, and will likely remain controversial for the foreseeable future. However, there is general agreement that some behaviors which are common in crocodiles and birds, dinosaurs' closest living relatives, were also common among dinosaurs. Gregarious behavior was common in many dinosaur species. Dinosaurs may have congregated in herds for defense, for migratory purposes, or to provide protection for their young. There is evidence that many types of dinosaurs, including various theropods, sauropods, ankylosaurians, ornithopods, and ceratopsians, formed aggregations of immature individuals. Nests and eggs have been found for most major groups of dinosaurs, and it appears likely that dinosaurs communicated with their young, in a manner similar to modern birds and crocodiles. The crests and frills of some dinosaurs, like the marginocephalians, theropods and lambeosaurines, may have been too fragile to be used for active defense, and so they were likely used for sexual or aggressive displays, though little is known about dinosaur mating and territorialism. Most dinosaurs seem to have relied on land-based locomotion. A good understanding of how dinosaurs moved on the ground is key to models of dinosaur behavior; the science of biomechanics, in particular, has provided significant insight in this area. For example, studies of the forces exerted by muscles and gravity on dinosaurs' skeletal structure have investigated how fast dinosaurs could run, whether diplodocids could create sonic booms via whip-like tail snapping, and whether sauropods could float.

9.5K
31 Oct 2022

Topic Review

The spirit spouse is one of the most widespread elements of shamanism, distributed through all continents and at all cultural levels. Often, these spirit husbands/wives are seen as the primary helping spirits of the shaman, who assist them in their work, and help them gain power in the world of spirit. The relationships shamans have with their spirit spouses may be expressed in romantic, sexual, or purely symbolic ways, and may include gender transformation as a part of correctly pairing with their "spouse". Shamans report engaging with their spirit spouses through dreams, trance, and other ritual elements. In some cultures, gaining a spirit spouse is a necessary and expected part of initiation into becoming a shaman. Evidence of spirit spouses may be seen in non-shamanic cultures as well, including dreams about Christ by nuns, who are considered to be "brides of Christ".

9.4K
16 Nov 2022

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