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Brainworm
''Parelaphostrongylus tenuis'' (also known as meningeal worm or brainworm) is a neurotropic nematode parasite common to white-tailed deer, ''Odocoileus virginianus'', which causes damage to the central nervous system. Moose (''Alces alces''), elk (''Cervus canadensis''), caribou (''Rangifer tarandus''), mule deer (''Odocoileus hemionus''), and others are also susceptible to the parasite, but are aberrant hosts and are infected in neurological instead of meningeal tissue. The frequency of infection in these species increases dramatically when their ranges overlap high densities of white-tailed deer. The lifecycle begins in infected meningeal tissues in the central nervous system (CNS) where adult brainworms lay eggs. The eggs are dislodged from the CNS and pass into the lungs, where they hatch. The larvae are then coughed up, swallowed, and proceed through the gastrointestinal tract. Snails and slugs then serve as intermediate hosts, which are later eaten by ungulates, allowing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moose
The moose (: 'moose'; used in North America) or elk (: 'elk' or 'elks'; used in Eurasia) (''Alces alces'') is the world's tallest, largest and heaviest extant species of deer and the only species in the genus ''Alces''. It is also the tallest, and the second-largest, land animal in North America, falling short only to the American bison in body mass. Most adult male moose have broad, palmate ("open-hand shaped") antlers; other members of the deer family have pointed antlers with a dendritic ("twig-like") configuration. Moose inhabit the circumpolar boreal forests or temperate broadleaf and mixed forests of the Northern Hemisphere, thriving in cooler, temperate areas as well as subarctic climates. Hunting shaped the relationship between moose and humans, both in Eurasia and North America. Prior to the colonial era (around 1600–1700 CE), moose were one of many valuable sources of sustenance for certain tribal groups and First Nations. Hunting and habitat loss hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caribou
The reindeer or caribou (''Rangifer tarandus'') is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of Northern Europe, Siberia, and North America. It is the only representative of the genus ''Rangifer''. More recent studies suggest the splitting of reindeer and caribou into six distinct species over their range. Reindeer occur in both migratory and sedentary populations, and their herd sizes vary greatly in different regions. The tundra subspecies are adapted for extreme cold, and some are adapted for long-distance migration. Reindeer vary greatly in size and color from the smallest, the Svalbard reindeer (''R.'' (''t.'') ''platyrhynchus''), to the largest, Osborn's caribou (''R. t. osborni''). Although reindeer are quite numerous, some species and subspecies are in decline and considered vulnerable. They are unique among deer (Cervidae) in that females may have antlers, although the prevalence of an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematode
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (helminths) are the cause of soil-transmitted helminthiases. They are classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa. Unlike the flatworms, nematodes have a tubular digestive system, with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species are uncertain. A 2013 survey of animal biodiversity suggested there are over 25,000. Estimates of the total number of extant species are su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White-tailed Deer
The white-tailed deer (''Odocoileus virginianus''), also known Common name, commonly as the whitetail and the Virginia deer, is a medium-sized species of deer native to North America, North, Central America, Central and South America. It is the most widely-distributed mainland ungulate herbivore in the Americas; coupled with its natural predator, the Cougar, mountain lion (''Puma concolor''), it is one of the most widely-distributed terrestrial mammal species in the Americas and the world. Highly adaptable, the various subspecies of white-tailed deer inhabit many different ecosystems, from arid grasslands to the Amazon basin, Amazon and Orinoco Basin, Orinoco basins; from the Pantanal and the Llanos to the high-elevation terrain of the Andes. Globally, the white-tailed deer has been introduced (primarily for Trophy hunting, sport hunting) to New Zealand, the Greater Antilles of the Caribbean (Cuba, Jamaica, Hispaniola, and Puerto Rico), and some countries in Europe (mainly the Cz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mule Deer
The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related white-tailed deer (''Odocoileus virginianus''), which is found throughout most of North America east of the Rocky Mountains and in the valleys of the Rocky Mountains from Idaho and Wyoming northward, mule deer are found only on the western Great Plains, in the Rocky Mountains, in the southwest United States, and on the west coast of North America. Mule deer have also been introduced to Argentina and Kauai, Kauai, Hawaii. Taxonomy Mule deer can be divided into two main groups: the mule deer (''sensu stricto'') and the black-tailed deer. The first group includes all subspecies, except ''O. h. columbianus'' and ''Sitka deer, O. h. sitkensis'', which are in the black-tailed deer group. The two main groups have been treated as separate species, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meninges
In anatomy, the meninges (; meninx ; ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid space between the arachnoid mater and the pia mater. The primary function of the meninges is to protect the central nervous system. Structure Dura mater The dura mater (), is a thick, durable membrane, closest to the Human skull, skull and vertebrae. The dura mater, the outermost part, is a loosely arranged, fibroelastic layer of cells, characterized by multiple interdigitating cell processes, no extracellular collagen, and significant extracellular spaces. The middle region is a mostly fibrous portion. It consists of two layers: the endosteal layer, which lies closest to the skull, and the inner meningeal layer, which lies closer to the brain. It contains larger blood vessels that split into the capillaries in the pia mater. It is composed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naivety
Naivety (also spelled naïvety), naiveness, or naïveté is the state of being naive. It refers to an apparent or actual lack of experience and sophistication, often describing a neglect of pragmatism in favor of moral idealism. A ''naïve'' may be called a ''naïf''. Etymology In its early use, the word ''naïve'' meant "natural or innocent", and did not connote ineptitude. As a French adjective, it is spelled ''naïve'', for feminine nouns, and ''naïf'', for masculine nouns. As a French noun, it is spelled ''naïveté''. It is sometimes spelled "naïve" with a diaeresis, but as an unitalicized English word, "naive" is now the more usual spelling. "naïf" often represents the French masculine, but has a secondary meaning as an artistic style. "Naïve" is pronounced as two syllables, in the French manner, and with the stress on the second one. Culture The naïf appears as a cultural type in two main forms. On the one hand, there is 'the satirical naïf, such as Candide'. No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruminant Diseases
Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The process, which takes place in the front part of the digestive system and therefore is called foregut fermentation, typically requires the fermented ingesta (known as cud) to be regurgitated and chewed again. The process of rechewing the cud to further break down plant matter and stimulate digestion is called rumination. The word "ruminant" comes from the Latin ''ruminare'', which means "to chew over again". The roughly 200 species of ruminants include both domestic and wild species. Ruminating mammals include cattle, all domesticated and wild bovines, goats, sheep, giraffes, deer, gazelles, and antelopes.Fowler, M.E. (2010).Medicine and Surgery of Camelids, Ames, Iowa: Wiley-Blackwell. Chapter 1 General Biology and Evol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic Nematodes Of Mammals
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson characterised parasites' way of feeding as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes. There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), trophicallytransmitted parasitism (by being eaten), vector-transmitted parasitism, parasitoidism, and micropredation. One major axis of classification concerns invasiveness: an endo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematodes Described In 1945
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (helminths) are the cause of soil-transmitted helminthiases. They are classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa. Unlike the flatworms, nematodes have a tubular digestive system, with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species are uncertain. A 2013 survey of animal biodiversity suggested there are over 25,000. Estimates of the total number of extant species are subject to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
