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Akodon Cursor
The cursor grass mouse or cursorial akodont (''Akodon cursor''), is a sigmodontine rodent from South America. Description The cursor grass mouse is a moderately sized rodent, with a head-body length of , and a tail long. Males are larger than females, weighing an average of , compared with for females. They have a typical mouse-like appearance, with short whiskers and stubby claws on the feet. They have dark to golden brown fur over most of their body, with paler greyish or yellowish underparts. Some have a whitish spot between the ears, but this is not present on all individuals. Cursor grass mice are members of the ''A. cursor'' species group, and very similar in appearance to other members of the group. In particular, they cannot easily be distinguished from the closely related montane grass mouse, which inhabits neighbouring regions to the immediate south. Although the cursor grass mouse is, on average, slightly larger than the montane species, there is too much overlap for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herluf Winge
Adolf Herluf Winge (19 March 1857 – 10 November 1923) was a Danish zoologist. Biography As a young student, along with his brother Oluf, Winge was interested in small mammals, particularly moles, shrews and insectivora. He studied mammalian dentition and produced a comparison of cusp similarities. He worked at the Zoological Museum in the University of Copenhagen The University of Copenhagen ( da, Københavns Universitet, KU) is a prestigious public university, public research university in Copenhagen, Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in ... from 1885. A major work was his three volumes of ''E Museo Lundii'' on the extinct fauna of South America with 75 plates that he drew. He also studied the animal remains found in the kitchen-middens of Denmark. Winge was described as a Lamarckist by some authors. References 1857 births 1923 deaths Danish zoologists Lamarckism {{Denmark-scientist-stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. It has a population of seven million, nearly three million of whom live in the capital and largest city of Asunción, and its surrounding metro. Although one of only two landlocked countries in South America (Bolivia is the other), Paraguay has ports on the Paraguay and Paraná rivers that give exit to the Atlantic Ocean, through the Paraná-Paraguay Waterway. Spanish conquistadores arrived in 1524, and in 1537, they established the city of Asunción, the first capital of the Governorate of the Río de la Plata. During the 17th century, Paraguay was the center of Jesuit missions, where the native Guaraní people were converted to Christianity and introduced to European culture. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akodon
''Akodon'' is a genus consisting of South American grass mice. They mostly occur south of the Amazon Basin and along the Andes north to Venezuela, but are absent from much of the basin itself, the far south of the continent, and the lowlands west of the Andes. ''Akodon'' is one of the most species-rich genera of Neotropical rodents. Species of ''Akodon'' are known to inhabit a variety of habitats from tropical and tropical moist forests to altiplano and desert. Fossils are known from the late Pliocene onwards. Taxonomy ''Akodon'' is the largest genus in the tribe Akodontini. Three of its synonyms—''Chalcomys'', ''Hypsimys'', and particularly ''Microxus''—have sometimes been regarded as distinct genera. Neomicroxus was separated in 2013. Previously associated with ''Akodon'', the genera ''Abrothrix'', '' Deltamys'', ''Necromys'', ''Thalpomys'', and '' Thaptomys'' are currently recognized as distinct. Some species of the tribe Abrotrichini are called akodons. The genus cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liposarcoma
Liposarcomas are the most common subtype of soft tissue sarcomas, accounting for at least 20% of all sarcomas in adults. Soft tissue sarcomas are rare neoplasms with over 150 different histological subtypes or forms. Liposarcomas arise from the precursor lipoblasts of the adipocytes (i.e. fat cells) in adipose (i.e. fat) tissues. Adipose tissues are distributed throughout the body, including such sites as the deep and more superficial layers of subcutaneous tissues as well as in less surgically accessible sites like the retroperitoneum (i.e. space behind the abdominal cavity) and visceral fat inside the abdominal cavity. All liposarcomas consist of at least some cells that bear a resemblance to fat cells when examined for their histopathologic appearances under a microscope. However, the liposarcomas do have several forms based on differences in their clinical presentations (e.g. ages, gender preferences, sites of tumors, signs, and symptoms), severities (i.e. potential to inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth. The time interval of a gestation is called the '' gestation period''. In obstetrics, ''gestational age'' refers to the time since the onset of the last menses, which on average is fertilization age plus two weeks. Mammals In mammals, pregnancy begins when a zygote (fertilized ovum) implants in the female's uterus and ends once the fetus leaves the uterus during labor or an abortion (whether induced or spontaneous). Humans In humans, pregnancy can be defined clinically or biochemically. Clinically, pregnancy starts from first day of the mother's last period. Biochemically, pregnancy starts when a woman's human chorionic gonadotropin (hCG) levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Home Range
A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He drew maps showing where the animal had been observed at different times. An associated concept is the utilization distribution which examines where the animal is likely to be at any given time. Data for mapping a home range used to be gathered by careful observation, but nowadays, the animal is fitted with a transmission collar or similar GPS device. The simplest way of measuring the home range is to construct the smallest possible convex polygon around the data but this tends to overestimate the range. The best known methods for constructing utilization distributions are the so-called bivariate Gaussian or normal distribution kernel density methods. More recently, nonparametric methods such as the Burgman and Fox's alpha-hull and Getz a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cecropia
''Cecropia'' is a Neotropical genus consisting of 61 recognized species with a highly distinctive lineage of dioecious trees. The genus consists of pioneer trees in the more or less humid parts of the Neotropics, with the majority of the species being myrmecophytic.Berg, Rosselli & Davidson (2005) Berg and Rosselli state that the genus is characterized by some unusual traits: spathes fully enclosing the flower-bearing parts of the inflorescences until anthesis, patches of dense indumentums (trichilia) producing Mullerian (food) at the base of the petiole, and anthers becoming detached at anthesis. ''Cecropia'' is most studied for its ecological role and association with ants. Its classification is controversial; in the past, it has been placed in the Cecropiaceae, Moraceae (the mulberry family), or Urticaceae (the nettle family).Burger (1977) The modern Angiosperm Phylogeny Group system places the "cecropiacean" group in the Urticaceae. The genus is native to the American tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beetle
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal life-forms; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species. Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae (ladybirds or ladybugs) eat aphids, scale insects, thrips, and other plant-sucking insects that damage crops. Beetles typically have a particularly hard e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hymenoptera
Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Parasitoid wasp, parasitic. Females typically have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. This ovipositor is often modified into a stinger. The young develop through holometabolism (complete metamorphosis (biology), metamorphosis)—that is, they have a wormlike larval stage and an inactive pupal stage before they mature. Etymology The name Hymenoptera refers to the wings of the insects, but the original derivation is ambiguous. All references agree that the derivation involves the Ancient Greek language, Ancient Greek wikt:πτερόν, πτερόν (''pteron'') for wing. The Ancient Greek wikt:ὑμήν, ὑμήν (''hymen'') for membrane provides a plausible etymology for the term bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the eighth-largest country in the world. It shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a federal state subdivided into twenty-three provinces, and one autonomous city, which is the federal capital and largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a federal system. Argentina claims sovereignty over the Falkland Islands, South Georgia and the South Sandwich Islands, and a part of Antarctica. The earliest recorded human prese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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