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Myopia In Animals
Some animals suffer from shortsightedness and have poor eyesight. In domestic animals, myopia, with or without Astigmatism (eye), astigmatism, occurs frequently. In cats Evolved for low-light hunting, cats' eyes are proportionally enormous. Their eye size makes focusing between near and far so difficult that the muscles develop with an environmental bias. Outdoor cats tend to be farsighted, while most indoor cats are nearsighted but not myopic. Cats are unable to focus on anything less than a foot in front of them. In dogs One animal species in which myopia occurs naturally is the domestic dog. Although the prevalence of myopia in dogs is breed dependent, approximately 8% to 15% of Labrador Retrievers are reported to have myopia. In rhinoceroses Whereas the rhinoceros may suffer from less-than-adequate eyesight, it generally survives by concentrating with its superior hearing and sense of smell. Some reports, however state that it can see better when focusing with one eye, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diceros Bicornis
The black rhinoceros, black rhino or hook-lipped rhinoceros (''Diceros bicornis'') is a species of rhinoceros, native to eastern and southern Africa including Angola, Botswana, Kenya, Malawi, Mozambique, Namibia, South Africa, Eswatini, Tanzania, Zambia, and Zimbabwe. Although the rhinoceros is referred to as ''black'', its colours vary from brown to grey. The other African rhinoceros is the white rhinoceros (''Ceratotherium simum''). The word "white" in the name "white rhinoceros" is often said to be a misinterpretation of the Afrikaans word ' (Dutch ') meaning wide, referring to its square upper lip, as opposed to the pointed or hooked lip of the black rhinoceros. These species are now sometimes referred to as the square-lipped (for white) or hook-lipped (for black) rhinoceros. The species overall is classified as critically endangered (even though the south-western black rhinoceros is classified as near threatened). Three subspecies have been declared extinct, including the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astigmatism (eye)
Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. This results in distorted or blurred vision at any distance. Other symptoms can include eyestrain, headaches, and trouble driving at night. Astigmatism often occurs at birth and can change or develop later in life. If it occurs in early life and is left untreated, it may result in amblyopia. The cause of astigmatism is unclear; however, it is believed to be partly related to genetic factors. The underlying mechanism involves an irregular curvature of the cornea and protective reaction changes in the lens of the eye, called lens astigmatism, that has the same mechanism as spasm of accomodation. Diagnosis is by an eye examination called autorefractor keratometry (objective, allows to see lens and cornea components of astigmatism) and subjective refraction, but subjective methods are almost always inaccurate, if lens astigmatism is not fully removed first with a week of eye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Shrews
The treeshrews (or tree shrews or banxrings) are small mammals native to the tropical forests of South and Southeast Asia. They make up the entire order Scandentia, which split into two families: the Tupaiidae (19 species, "ordinary" treeshrews), and the Ptilocercidae (one species, the pen-tailed treeshrew). Though called 'treeshrews', and despite having previously been classified in Insectivora, they are not true shrews, and not all species live in trees. They are omnivores; among other things, treeshrews eat fruit. Treeshrews have a higher brain to body mass ratio than any other mammal, including humans, but high ratios are not uncommon for animals weighing less than . Among orders of mammals, treeshrews are closely related to primates, and have been used as an alternative to primates in experimental studies of myopia, psychosocial stress, and hepatitis. Name The name '' Tupaia'' is derived from ''tupai'', the Indonesian word for squirrel, and was provided by Sir Stamford ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macaques
The macaques () constitute a genus (''Macaca'') of sociality, gregarious Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques inhabit species distribution, ranges throughout Asia, North Africa, and (in barbary macaques in Gibraltar, one instance) Gibraltar. Macaques are principally frugivore, frugivorous (preferring fruit), although their diet also includes seeds, leaves, flowers, and tree bark. Some species, such as the crab-eating macaque, subsist on a diet of invertebrates and occasionally small vertebrates. On average, southern pig-tailed macaques in Malaysia eat about 70 large rats each per year. All macaque social groups are matriarchy, matriarchal, arranged around dominant females. Macaques are found in a variety of habitats throughout the Asian continent and are highly adaptation, adaptable. Certain species have learned to synanthrope, live with humans and have become invasive in some human settlement, human-settled built environment, environment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinoscopy
Retinoscopy (Ret) is a technique to obtain an objective measurement of the refractive error of a patient's eyes. The examiner uses a retinoscope to shine light into the patient's eye and observes the reflection (reflex) off the patient's retina. While moving the streak or spot of light across the pupil the examiner observes the relative movement of the reflex or manually places lenses over the eye (using a trial frame and trial lenses) to "neutralize" the reflex. Static retinoscopy is a type of retinoscopy used in determining a patient's refractive error. It relies on Foucault knife-edge test, which states that the examiner should simulate optical infinity to obtain the correct refractive power. Hence, a power corresponding to the working distance is subtracted from the gross retinoscopy value to give the patient's refractive condition, the working distance lens being one which has a focal length of the examiner's distance from the patient (e.g. +1.50 dioptre lens for a 67 cm w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Shepherd
The German Shepherd or Alsatian is a German breed of working dog of medium to large size. The breed was developed by Max von Stephanitz using various traditional German herding dogs from 1899. It was originally bred as a herding dog, for herding sheep. It has since been used in many other types of work, including disability assistance, search-and-rescue, police work, and warfare. It is commonly kept as a companion dog, and according to the Fédération Cynologique Internationale had the second-highest number of annual registrations in 2013. History During the 1890s, attempts were being made to standardise dog breeds. Dogs were being bred to preserve traits that assisted in their job of herding sheep and protecting their flocks from predators. In Germany this was practised within local communities, where shepherds selected and bred dogs. It was recognised that the breed had the necessary skills for herding sheep, such as intelligence, speed, strength and keen senses o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rottweiler
The Rottweiler (, ) is a breed of domestic dog, regarded as medium-to-large or large. The dogs were known in German as , meaning Rottweil butchers' dogs, because their main use was to herd livestock and pull carts laden with butchered meat to market. This continued until the mid-19th century when railways replaced droving. Although still used to herd stock in many parts of the world, Rottweilers are now also used as search and rescue dogs, guard dogs, and police dogs.Adolf Pienkoss, ''The Rottweiler'', 3rd ed., Borken, Germany: Internationale Föderation der Rottweilerfreunde, 2008. History According to the FCI Standard, the Rottweiler is considered to be one of the oldest surviving dog breeds. Its origin goes back to Roman times. These dogs were kept as herder or driving dogs. They marched over the Alps with the Roman legions, protecting the humans and driving their cattle. In the region of Rottweil, these dogs met and mixed with the native dogs in a natural crossing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miniature Horse
A miniature horse is a breed A breed is a specific group of domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist several slig ... or type of horse characterised by its small size. Usually it has been bred to display in miniature the morphology (biology), physical characteristics of a full-sized horse, but to be little over in height, or even less. Although such horses have the appearance of small horses, they are genetically much more similar to pony breeds such as the Shetland (pony), Shetland. They have various colors and coat patterns. Miniature horses are present in several countries, including Argentina, Australia, France, Germany, Holland, Ireland, Namibia, the Philippines, the United Kingdom and the United States. In some countries they have the status of a breed; these include the Falabella of Argentina, the Dutch Miniatu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Sclerosis
Nuclear sclerosis is an age-related change in the density of the crystalline lens The lens, or crystalline lens, is a transparent biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. By changing shape, it functions to change the focal length of the eye so that it ca ... nucleus that occurs in all older animals. It is caused by compression of older lens fibers in the nucleus by new fiber formation. The denser construction of the nucleus causes it to scattering, scatter light. Although nuclear sclerosis may describe a type of early cataract in medicine, human medicine,Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company, 1990. in veterinary medicine the term is also known as lenticular sclerosis and describes a bluish-grey haziness at the nucleus that usually does ''not'' affect vision, except for unusually dense cases. Immature senile cataract has to be differenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystalline Lens
The lens, or crystalline lens, is a transparent biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. By changing shape, it functions to change the focal length of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. This adjustment of the lens is known as '' accommodation'' (see also below). Accommodation is similar to the focusing of a photographic camera via movement of its lenses. The lens is flatter on its anterior side than on its posterior side. In humans, the refractive power of the lens in its natural environment is approximately 18 dioptres, roughly one-third of the eye's total power. Structure The lens is part of the anterior segment of the human eye. In front of the lens is the iris, which regulates the amount of light entering into the eye. The lens is suspended in place by the suspensory ligament of the lens, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macaque
The macaques () constitute a genus (''Macaca'') of gregarious Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques inhabit ranges throughout Asia, North Africa, and (in one instance) Gibraltar. Macaques are principally frugivorous (preferring fruit), although their diet also includes seeds, leaves, flowers, and tree bark. Some species, such as the crab-eating macaque, subsist on a diet of invertebrates and occasionally small vertebrates. On average, southern pig-tailed macaques in Malaysia eat about 70 large rats each per year. All macaque social groups are matriarchal, arranged around dominant females. Macaques are found in a variety of habitats throughout the Asian continent and are highly adaptable. Certain species have learned to live with humans and have become invasive in some human-settled environments, such as the island of Mauritius and Silver Springs State Park in Florida. Macaques can be a threat to wildlife conservation as well as to hum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.The elements are from different metal groups. See periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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