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Topic Review
Short-Beaked Echidna
The short-beaked echidna (Tachyglossus aculeatus) is one of four living species of echidna and the only member of the genus Tachyglossus. It is covered in fur and spines and has a distinctive snout and a specialized tongue, which it uses to catch its insect prey at a great speed. Like the other extant monotremes, the short-beaked echidna lays eggs; the monotremes are the only living group of mammals to do so. The short-beaked echidna has extremely strong front limbs and claws, which allow it to burrow quickly with great power. As it needs to be able to survive underground, it has a significant tolerance to high levels of carbon dioxide and low levels of oxygen. It has no weapons or fighting ability but repels predators by curling into a ball and deterring them with its spines. It lacks the ability to sweat and cannot deal with heat well, so it tends to avoid daytime activity in hot weather. It can swim if needed. The snout has mechanoreceptors and electroreceptors that help the echidna to detect its surroundings. During the Australia n winter, it goes into deep torpor and hibernation, reducing its metabolism to save energy. As the temperature increases, it emerges to mate. Female echidnas lay one egg a year and the mating period is the only time the otherwise solitary animals meet one another; the male has no further contact with the female or his offspring after mating. A newborn echidna is the size of a grape but grows rapidly on its mother's milk, which is very rich in nutrients. Baby echidnas eventually grow too large and spiky to stay in the pouch and, around seven weeks after hatching, are expelled from the pouch into the mother's burrow. At around six months of age, they leave the burrow and have no more contact with their mothers. The species is found throughout Australia, where it is the most widespread native mammal, and in coastal and highland regions of eastern New Guinea, where it is known as the mungwe in the Daribi and Chimbu languages. It is not threatened with extinction, but human activities, such as hunting, habitat destruction, and the introduction of foreign predatory species and parasites, have reduced its distribution in Australia.
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  • 29 Nov 2022
Topic Review
Addax (Genus)
The addax (Addax nasomaculatus), also known as the white antelope and the screwhorn antelope, is an antelope native to the Sahara Desert. The only member of the genus Addax, it was first described scientifically by Henri de Blainville in 1816. As suggested by its alternative name, the pale antelope has long, twisted horns - typically 55 to 80 cm (22 to 31 in) in females and 70 to 85 cm (28 to 33 in) in males. Males stand from 105 to 115 cm (41 to 45 in) at the shoulder, with females at 95 to 110 cm (37 to 43 in). They are sexually dimorphic, as the females are smaller than the males. The colour of the coat depends on the season - in the winter, it is greyish-brown with white hindquarters and legs, and long, brown hair on the head, neck, and shoulders; in the summer, the coat turns almost completely white or sandy blonde. The addax mainly eats grasses and leaves of any available shrubs, leguminous herbs and bushes. They are well-adapted to exist in their desert habitat, as they can live without water for long periods of time. Addax form herds of five to 20 members, consisting of both males and females. They are led by the oldest female. Due to its slow movements, the addax is an easy target for its predators: humans, lions, leopards, cheetahs and African wild dogs. Breeding season is at its peak during winter and early spring. The natural habitat of the addax are arid regions, semideserts and sandy and stony deserts. The addax is a critically endangered species of antelope, as classified by the IUCN. Although extremely rare in its native habitat due to unregulated hunting, it is quite common in captivity. The addax was once abundant in North Africa; however it is currently only native to Chad, Mauritania, and Niger. It is extirpated from Algeria, Egypt, Libya, Sudan, and Western Sahara, but has been reintroduced into Morocco and Tunisia.
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  • 04 Nov 2022
Topic Review
BRCA Mutation
A BRCA mutation is a mutation in either of the BRCA1 and BRCA2 genes, which are tumour suppressor genes. Hundreds of different types of mutations in these genes have been identified, some of which have been determined to be harmful, while others have no proven impact. Harmful mutations in these genes may produce a hereditary breast–ovarian cancer syndrome in affected persons. Only 5–10% of breast cancer cases in women are attributed to BRCA1 and BRCA2 mutations (with BRCA1 mutations being slightly more common than BRCA2 mutations), but the impact on women with the gene mutation is more profound. Women with harmful mutations in either BRCA1 or BRCA2 have a risk of breast cancer that is about five times the normal risk, and a risk of ovarian cancer that is about ten to thirty times normal. The risk of breast and ovarian cancer is higher for women with a high-risk BRCA1 mutation than with a BRCA2 mutation. Having a high-risk mutation does not guarantee that the woman will develop any type of cancer, or imply that any cancer that appears was actually caused by the mutation, rather than some other factor. High-risk mutations, which disable an important error-free DNA repair process (homology directed repair), significantly increase the person's risk of developing breast cancer, ovarian cancer and certain other cancers. Why BRCA1 and BRCA2 mutations lead preferentially to cancers of the breast and ovary is not known, but lack of BRCA1 function seems to lead to non-functional X-chromosome inactivation. Not all mutations are high-risk; some appear to be harmless variations. The cancer risk associated with any given mutation varies significantly and depends on the exact type and location of the mutation and possibly other individual factors. Mutations can be inherited from either parent and may be passed on to both sons and daughters. Each child of a genetic carrier, regardless of sex, has a 50% chance of inheriting the mutated gene from the parent who carries the mutation. As a result, half of the people with BRCA gene mutations are male, who would then pass the mutation on to 50% of their offspring, male or female. The risk of BRCA-related breast cancers for men with the mutation is higher than for other men, but still low. However, BRCA mutations can increase the risk of other cancers, such as colon cancer, pancreatic cancer, and prostate cancer. Methods to diagnose the likelihood of a patient with mutations in BRCA1 and BRCA2 getting cancer were covered by patents owned or controlled by Myriad Genetics. Myriad's business model of exclusively offering the diagnostic test led to Myriad growing from being a startup in 1994 to being a publicly traded company with 1200 employees and about $500M in annual revenue in 2012; it also led to controversy over high prices and the inability to get second opinions from other diagnostic labs, which in turn led to the landmark Association for Molecular Pathology v. Myriad Genetics lawsuit.
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  • 01 Dec 2022
Biography
Frederick Wollaston Hutton
Captain Frederick Wollaston Hutton, FRS, (16 November 1836 – 27 October 1905) was an English-New Zealand scientist who applied the theory of natural selection to explain the origins and nature of the natural history of New Zealand. An army officer in early life, he then had an academic career in geology and biology. He became one of the most able and prolific nineteenth century naturalists of
  • 1.7K
  • 11 Nov 2022
Topic Review
Polymorphism
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative phenotypes, in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the same genotype. Genetic polymorphism is a term used somewhat differently by geneticists and molecular biologists to describe certain mutations in the genotype, such as single nucleotide polymorphisms that may not always correspond to a phenotype, but always corresponds to a branch in the genetic tree. See below. Polymorphism is common in nature; it is related to biodiversity, genetic variation, and adaptation. Polymorphism usually functions to retain a variety of forms in a population living in a varied environment.:126 The most common example is sexual dimorphism, which occurs in many organisms. Other examples are mimetic forms of butterflies (see mimicry), and human hemoglobin and blood types. According to the theory of evolution, polymorphism results from evolutionary processes, as does any aspect of a species. It is heritable and is modified by natural selection. In polyphenism, an individual's genetic makeup allows for different morphs, and the switch mechanism that determines which morph is shown is environmental. In genetic polymorphism, the genetic makeup determines the morph. The term polymorphism also refers to the occurrence of structurally and functionally more than two different types of individuals, called zooids, within the same organism. It is a characteristic feature of cnidarians. For example, Obelia has feeding individuals, the gastrozooids; the individuals capable of asexual reproduction only, the gonozooids, blastostyles; and free-living or sexually reproducing individuals, the medusae. Balanced polymorphism refers to the maintenance of different phenotypes in population.
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  • 07 Nov 2022
Biography
Lynn Townsend White Jr.
Lynn Townsend White Jr. (April 29, 1907 – March 30, 1987) was an American historian. He was a professor of medieval history at Princeton from 1933 to 1937, and at Stanford from 1937 to 1943. He was president of Mills College, Oakland, from 1943 to 1958 and a professor at University of California, Los Angeles from 1958 until 1987.[1] Lynn White helped to found The Society of History and Technol
  • 1.7K
  • 15 Dec 2022
Biography
Hertha Sponer
Hertha Sponer (1 September 1895 – 27 February 1968) was a German physicist and chemist who contributed to modern quantum mechanics and molecular physics and was the first woman on the physics faculty of Duke University. She was the older sister of philologist and resistance fighter Margot Sponer.[1] Sponer was born in Neisse (Nysa), Prussian Silesia, and obtained her high school degree in N
  • 1.7K
  • 22 Nov 2022
Topic Review
Embryogenesis
Embryogenesis is the process by which the embryo forms and develops. In mammals, the term refers chiefly to early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. Embryogenesis starts with the fertilization of the egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum is referred to as a zygote, a single diploid cell. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo. Although embryogenesis occurs in both animal and plant development, this article addresses the common features among different animals, with some emphasis on the embryonic development of vertebrates and mammals.
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  • 10 Nov 2022
Biography
Susana Martinez-Conde
Susana Martinez-Conde (born October 1, 1969) is a neuroscientist and science writer. She is a professor of ophthalmology, neurology, and physiology & pharmacology at the State University of New York, Downstate Medical Center, where she directs the Laboratory of Integrative Neuroscience. She directed laboratories previously at the Barrow Neurological Institute and University College London.[1] He
  • 1.7K
  • 28 Nov 2022
Topic Review
Cashew Production in Tanzania
Tanzania is one of the largest cashew producers in Africa, with exports providing 10-15 percent of the country's foreign exchange. The country is the eighth-largest grower of cashew nut in the world and ranks fourth in Africa. The country provides 20% of Africa's cashew nut and only trails in production of Nigeria, Cote D'Ivoire, and Guinea-Bissau, according to figures released in 2012 by United Nations Food and Agricultural Organisation (FAO). The country has been engaged in the production of the cash crop since before independence in the years 1960s however, poor regulation and lack of reliable payments to farmers have posed significant challenges to the Cashew Nut farming industry in Tanzania. Guinea-Bissau, a country a tenth of the area of Tanzania's, has a significantly greater yield. The cash crop is usually cultivated in the southern coastal regions of the country, near the towns of Mtwara, Kilwa and Dar es Salaam. The sale and marketing of the product is run by the Cashewnut Board of Tanzania, through various farmer co-operatives. More than ninety percent of the exports are destined for India and almost entirely in raw form. The lack of domestic processing firms costs the country vital foreign revenues and thousands of jobs. The Tanzanian government has been facing challenges for finding potential investors in order to revive the cashew processing industry in Tanzania.
  • 1.7K
  • 16 Nov 2022
Topic Review
Malting Process
The malting process converts raw grain into malt. The malt is mainly used for brewing or whisky making, but can also be used to make malt vinegar or malt extract. Various grains are used for malting; the most common are barley, sorghum, wheat and rye. There are a number of different types of equipment that can be used to produce the malt. A traditional floor malting germinates the grains in a thin layer on a solid floor, and the grain is manually raked and turned to keep the grains loose and aerated. In a modern malt house the process is more automated, and the grain is germinated on a floor that is slotted to allow air to be forced through the grain bed. Large mechanical turners keep the much thicker bed loose with higher productivity and better energy efficiency.
  • 1.7K
  • 11 Oct 2022
Biography
Guillermo Söhnlein
Guillermo Adrian Miguel Söhnlein (born May 18, 1966 in Buenos Aires, Argentina) is an American social entrepreneur with special interests in the commercialization of outer space, the exploration of the world's oceans, and the global connections between space and ocean industries. Guillermo Söhnlein was born in Buenos Aires, Argentina , on May 18, 1966. He immigrated to the United States in
  • 1.7K
  • 01 Dec 2022
Biography
Emil Georg Cohn
Emil Georg Cohn (28 September 1854 – 28 January 1944), was a German physicist. Cohn was born in Neustrelitz, Mecklenburg on 28 September 1854. He was the son of August Cohn, a lawyer, and Charlotte Cohn. At the age of 17, Cohn began to study jurisprudence at the University of Leipzig. However, at the Ruprecht Karl University of Heidelberg and the University of Strasbourg he began to study p
  • 1.7K
  • 30 Dec 2022
Topic Review
Postmenopausal Confusion
Postmenopausal confusion, also commonly referred to as postmenopausal brain fog, is a group of symptoms of menopause in which women report problems with cognition at a higher frequency during postmenopause than before. Multiple studies on cognitive performance following menopause have reported noticeable declines of greater than 60%. The common issues presented included impairments in reaction time and attention, difficulty recalling numbers or words, and forgetting reasons for involvement in certain behaviors. Association between subjective cognitive complaints and objective measures of performance show a significant impact on health-related quality of life for postmenopausal women. Treatment primarily involves symptom management through non-pharmacological treatment strategies. This includes involvement in physical activity and following medically supervised diets, especially those that contain phytoestrogens or resveratrol. Pharmacological interventions in treating postmenopausal confusion are currently being researched. Hormone therapy is currently not indicated for the treatment of postmenopausal confusion due to inefficacy. The use of hormone replacement therapy for approved indications has identified no significant negative effect on postmenopausal cognition. Although much of the literature references women, it is important to understand that all people who undergo menopause, including those who do not self-identify as women, may experience symptoms of postmenopausal confusion.
  • 1.7K
  • 04 Nov 2022
Biography
Mathias Jucker
Mathias Jucker, born 7 July 1961 in Zürich, Switzerland , is a Swiss neuroscientist, Professor, and a Director at the Hertie Institute for Clinical Brain Research of the University of Tübingen, Germany . He is also a Group Leader at the German Center for Neurodegenerative Diseases (German: Deutsches Zentrum für Neurodegenerative Erkrankungen, (DZNE)) in Tübingen. Jucker is known for his rese
  • 1.7K
  • 30 Dec 2022
Topic Review
Living Root Bridges
Template:Infobox bridge Living root bridges are a form of tree shaping common in the southern part of the Northeast Indian state of Meghalaya. They are handmade from the aerial roots of rubber fig trees (Ficus elastica) by the Khasi and Jaintia peoples of the mountainous terrain along the southern part of the Shillong Plateau. Root bridges have also been observed in the Indian state of Nagaland. Living root bridges have also been created in Indonesia at Jembatan akar on the island of Sumatra, and in the banten provence of Java , by the Baduy people.
  • 1.7K
  • 21 Nov 2022
Topic Review
Megapnosaurus Rhodesiensis
Coelophysis rhodesiensis is an extinct species of coelophysid theropod dinosaur that lived approximately 188 million years ago during the early part of the Jurassic Period in what is now Africa. The species was a small to medium-sized, lightly built, ground-dwelling, bipedal carnivore, that could grow up to 3 m (9.8 ft) long. It was formerly called Syntarsus, but that name was already taken by a beetle, and was subsequently given the name Megapnosaurus by Ivie, Ślipiński & Węgrzynowicz, in 2001, though many subsequent studies have classified it in the genus Coelophysis.
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  • 28 Nov 2022
Topic Review
Outline of Biophysics
The following outline is provided as an overview of and topical guide to biophysics: Biophysics – interdisciplinary science that uses the methods of physics to study biological systems.
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  • 02 Nov 2022
Topic Review
Discriminative Measurement for Radon Isotopes
Radon and thoron measurement studies have been widely conducted and reported all over the world. Generally, the techniques used relate to the passive nuclear track detectors. Though some surveys shown that passive monitors for radon are sensitive to thoron, and hence the measured results might be probably overestimated the radon concentration. This study investigated the radon and thoron measurement in domestic and international using passive radon-thoron discriminative measuring device, commercially named RADUET. This paper attempts to provide an understanding and evident roadmap for discriminative measurements of radon isotopes.
  • 1.7K
  • 05 Nov 2020
Biography
Janet Pierrehumbert
Janet Pierrehumbert /pɪərˈhʌmbərt/ is Professor of Language Modeling in the Oxford e-Research Centre at the University of Oxford and a senior research fellow of Trinity College, Oxford.[1] She developed an intonational model which includes a grammar of intonation patterns and an explicit algorithm for calculating pitch contours in speech, as well as an account of intonational meaning.[2][3]
  • 1.7K
  • 24 Nov 2022
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