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Negative Strand RNA Viruses
Negative-strand RNA viruses (−ssRNA viruses) are a group of related viruses that have negative-sense, single-stranded genomes made of ribonucleic acid (RNA). They have genomes that act as complementary strands from which messenger RNA (mRNA) is synthesized by the viral enzyme RNA-dependent RNA polymerase (RdRp). During replication of the viral genome, RdRp synthesizes a positive-sense antigenome that it uses as a template to create genomic negative-sense RNA. Negative-strand RNA viruses also share a number of other characteristics: most contain a viral envelope that surrounds the capsid, which encases the viral genome, −ssRNA virus genomes are usually linear, and it is common for their genome to be segmented. Negative-strand RNA viruses constitute the phylum ''Negarnaviricota'', in the kingdom ''Orthornavirae'' and realm ''Riboviria''. They are descended from a common ancestor that was a double-stranded RNA (dsRNA) virus, and they are considered to be a sister clade of reovi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Electron Micrograph
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and Focus (optics), focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a Detectors for transmission electron microscopy, detector such as a scintillator attached to a charge-coupled device or a direct electron detector. Transmission electron microscopes are capable of imaging at a significantly higher Optical resolution, resolution than Optical microscope, light microscopes, owing to the smaller de Broglie wavelength of electrons. This enables the instrument to capture fine detail—even as small as a single column of atoms, which is thousands o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthornavirae
''Orthornavirae'' is a kingdom of viruses that have genomes made of ribonucleic acid (RNA), including genes which encode an RNA-dependent RNA polymerase (RdRp). The RdRp is used to transcribe the viral RNA genome into messenger RNA (mRNA) and to replicate the genome. Viruses in this kingdom share a number of characteristics which promote rapid evolution, including high rates of genetic mutation, recombination, and reassortment. Viruses in ''Orthornavirae'' belong to the realm ''Riboviria''. They are descended from a common ancestor that may have been a non-viral molecule that encoded a reverse transcriptase instead of an RdRp for replication. The kingdom is subdivided into seven phyla that separate member viruses based on their genome type, host range, and genetic similarity. Viruses with three genome types are included: positive-strand RNA viruses, negative-strand RNA viruses, and double-stranded RNA viruses. Many of the most widely known viral diseases are caused by membe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lassa Fever Virus
Lassa virus (LASV) is an arenavirus that causes Lassa hemorrhagic fever, a type of viral hemorrhagic fever (VHF), in humans and other primates. Lassa virus is an emerging virus and a select agent, requiring Biosafety Level 4-equivalent containment. It is endemic in West African countries, especially Sierra Leone, the Republic of Guinea, Nigeria, and Liberia, where the annual incidence of infection is between 300,000 and 500,000 cases, resulting in 5,000 deaths per year. As of 2012 discoveries within the Mano River region of west Africa have expanded the endemic zone between the two known Lassa endemic regions, indicating that LASV is more widely distributed throughout the tropical wooded savannah ecozone in west Africa. There are no approved vaccines against Lassa fever for use in humans. Discovery In 1969, missionary nurse Laura Wine fell ill with a mysterious disease she contracted from an obstetrical patient in Lassa, a village in Borno State, Nigeria. She was then tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Influenza Virus
''Orthomyxoviridae'' () is a family of negative-sense RNA viruses. It includes nine genera: '' Alphainfluenzavirus'', '' Betainfluenzavirus'', '' Gammainfluenzavirus'', '' Deltainfluenzavirus'', '' Isavirus'', '' Mykissvirus'', '' Quaranjavirus'', '' Sardinovirus'', and '' Thogotovirus''. The first four genera contain viruses that cause influenza in birds (see also avian influenza) and mammals, including humans. Isaviruses infect salmon; the thogotoviruses are arboviruses, infecting vertebrates and invertebrates (such as ticks and mosquitoes). The Quaranjaviruses are also arboviruses, infecting vertebrates (birds) and invertebrates (arthropods). The four genera of Influenza virus that infect vertebrates, which are identified by antigenic differences in their nucleoprotein and matrix protein, are as follows: * '' Alphainfluenzavirus'' infects humans, other mammals, and birds, and causes all flu pandemics * '' Betainfluenzavirus'' infects humans and seals * '' Gammainfluenz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hantavirus
''Orthohantavirus'' is a genus of viruses that includes all hantaviruses (family ''Hantaviridae'') that cause disease in humans. Orthohantaviruses, hereafter referred to as hantaviruses, are naturally found primarily in rodents. In general, each hantavirus is carried by one rodent species and each rodent that carries a hantavirus carries one hantavirus species. Hantaviruses in their natural reservoirs usually cause an asymptomatic, persistent infection. In humans, however, hantaviruses cause two diseases: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). HFRS is mainly caused by hantaviruses in Africa, Asia, and Europe, called Old World hantaviruses, and HPS is usually caused by hantaviruses in the Americas, called New World hantaviruses. Hantaviruses are transmitted mainly through aerosols and droplets that contain rodent excretions, as well as through contaminated food, bites, and scratches. Environmental factors such as rainfall, temperature, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebola Virus
''Orthoebolavirus zairense'' or Zaire ebolavirus, more commonly known as Ebola virus (; EBOV), is one of six known species within the genus ''Ebolavirus''. Four of the six known ebolaviruses, including EBOV, cause a severe and often fatal viral hemorrhagic fever, hemorrhagic fever in humans and other mammals, known as Ebola virus disease (EVD). Ebola virus has caused the majority of human deaths from EVD, and was the cause of the Western African Ebola virus epidemic, 2013–2016 epidemic in western Africa, which resulted in at least suspected cases and confirmed deaths. Ebola virus and its genus were both originally named for Zaire (now the Democratic Republic of the Congo), the country where it was List of Ebola outbreaks, first described, and was at first suspected to be a new "strain" of the closely related Marburg virus. The virus was renamed "Ebola virus" in 2010 to avoid confusion. Ebola virus is the single member of the species ''Zaire ebolavirus'', which is assigned t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomato Spotted Wilt Virus
Tomato spotted wilt virus (TSWV) is a spherical Sense (molecular biology), negative-sense RNA virus. Transmitted by thrips, it causes serious losses in economically important crops and it is one of the most economically devastating plant viruses in the world. Transmission and lifespan The circulative propagative transmission of TSWV is carried out by at least 10 different species of thrips. The most common species is ''Frankliniella occidentalis'' (western flower thrips) as it is the Vector (epidemiology), vector that predominantly transmits TSWV globally and in greenhouses. The rapid developmental and reproductive rate of the thrips contributes to the spread of TSWV. The time needed for insects to acquire the virus (acquisition period) and the time needed for the virus to move from the insect to the plant (inoculation) for TSWV varies depends on the vector species. For ''F. occidentalis'', the acquisition and inoculation of TSWV can be as short as 5 minutes. However, the acq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rift Valley Fever Virus
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems. Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates. ''Failed rifts'' are the result of continental rifting that failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to the poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metamerism (biology), metameric) Segmentation (biology), segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species. Haemolymph is the analogue of blood for most arthropods. An arthropod has an open circulatory system, with a body cavity called a haemocoel through which haemolymph circulates to the interior Organ (anatomy), organs. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. They have ladder-like nervous systems, with paired Anatomical terms of location#Dorsal and ventral, ventral Ventral nerve cord, nerve cord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cap Snatching
A cap is a flat headgear, usually with a visor. Caps have crowns that fit very close to the head. They made their first appearance as early as 3200 BC. The origin of the word "cap" comes from the Old French word "chapeau" which means "head covering". Over time, the word has evolved and changed its meaning, but it still retains its association with headwear. Caps typically have a visor, or no brim at all. They are popular in casual and informal settings, and are seen in sports and fashion. They are typically designed for warmth, and often incorporate a visor to block sunlight from the eyes. They come in many shapes, sizes, and are of different brands. Baseball caps are one of the most common types of cap. Types * Ascot cap * Ayam * Baggy green * Balmoral * Beanie (North America) * Bearskin * Beret * Biretta * Busby * Canterbury cap * Cap and bells * Cap of maintenance * Casquette * Caubeen * Caul * Coif * Combination cap (also known as a service cap) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyploviricotina
''Polyploviricotina'' is a subphylum of viruses in the phylum ''Negarnaviricota''. It is one of only two virus subphyla, the other being '' Haploviricotina'', which is also in ''Negarnaviricota''. The name comes from , the Ancient Greek for 'complex', along with the suffix for a virus subphylum; 'viricotina'. Taxonomy The subphylum contains the following classes and orders (-''viricetes'' denotes class and -''virales'' denotes order): * '' Bunyaviricetes'' ** ''Elliovirales ''Elliovirales'' is an order of viruses. Taxonomy The order contains the following families: * '' Cruliviridae'' * ''Fimoviridae'' * ''Hantaviridae'' * ''Peribunyaviridae'' * '' Phasmaviridae'' * ''Tospoviridae ''Orthotospovirus'' is a genus o ...'' ** '' Hareavirales'' * '' Insthoviricetes'' ** '' Articulavirales'' References External links Invasion of the Body Snatchers: Viruses Can Steal Our Genetic Code to Create New Human-Virus Genes on: SciTechDaily, Source: Mount Sinai School of Medicine; Au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haploviricotina
''Haploviricotina'' is a subphylum of viruses in the phylum ''Negarnaviricota''. It is one of only two virus subphyla, the other being ''Polyploviricotina'', which is also in ''Negarnaviricota''. The name comes from , the Ancient Greek for 'simple', along with the suffix for a virus subphylum; 'viricotina'. Taxonomy The subphylum ''Haploviricotina'' is composed of 4 classes and 5 orders: * '' Chunqiuviricetes'' ** '' Muvirales'' * ''Milneviricetes'' ** '' Serpentovirales'' * ''Monjiviricetes'' ** '' Jingchuvirales'' ** ''Mononegavirales ''Mononegavirales'' is an order of negative-strand RNA viruses which have nonsegmented genomes. Some members that cause human disease in this order include Ebola virus, human respiratory syncytial virus, measles virus, mumps virus, Nipah viru ...'' * '' Yunchangviricetes'' ** '' Goujianvirales'' References Negarnaviricota Virus subphyla {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
