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Canon RF Mount
The Canon RF lens mount is an interchangeable-lens mount developed by Canon for its full-frame mirrorless interchangeable-lens cameras, and featured first by the EOS R, followed by the EOS RP. The RF mount was announced in September 2018. In May 2022, Canon announced APS-C EOS R cameras (the EOS R10 and EOS R7) and RF-S lenses designed for these cameras. The RF mount allows for the use of Canon EF and EF-S mount lenses using one of three Canon-made lens adapters. When an RF-S or EF-S lens is attached, however, the camera will only function as an APS-C camera, not a full-frame camera. Details Canon full-frame cameras have used the EF lens mount since 1987. In comparison with that mount, the RF mount's inner diameter is the same at 54 mm. The RF mount's flange focal distance at 20 mm is much shorter than that of the Canon EF and EF-S mounts at 44 mm. The EF-M mount has a flange focal distance of 18 mm. An EF-EOS R lens adapter enables Canon EF, EF-S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Release Factor
A release factor is a protein that allows for the termination of translation by recognizing the termination codon or stop codon in an mRNA sequence. They are named so because they release new peptides from the ribosome. Background During translation of mRNA, most codons are recognized by "charged" tRNA molecules, called aminoacyl-tRNAs because they are adhered to specific amino acids corresponding to each tRNA's anticodon. In the standard genetic code, there are three mRNA stop codons: UAG ("amber"), UAA ("ochre"), and UGA ("opal" or "umber"). Although these stop codons are triplets just like ordinary codons, they are not decoded by tRNAs. It was discovered by Mario Capecchi in 1967 that, instead, tRNAs do not ordinarily recognize stop codons at all, and that what he named "release factor" was not a tRNA molecule but a protein. Later, it was demonstrated that different release factors recognize different stop codons. Classification There are two classes of release fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conductors can radiate into space as electromagnetic waves ( radio waves). This is the basis of radio technology. * RF current does not penetrate deeply into electri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Forest
Random forests or random decision forests is an ensemble learning method for classification, regression and other tasks that operates by constructing a multitude of decision trees at training time. For classification tasks, the output of the random forest is the class selected by most trees. For regression tasks, the mean or average prediction of the individual trees is returned. Random decision forests correct for decision trees' habit of overfitting to their training set. Random forests generally outperform decision trees, but their accuracy is lower than gradient boosted trees. However, data characteristics can affect their performance. The first algorithm for random decision forests was created in 1995 by Tin Kam Ho using the random subspace method, which, in Ho's formulation, is a way to implement the "stochastic discrimination" approach to classification proposed by Eugene Kleinberg. An extension of the algorithm was developed by Leo Breiman and Adele Cutler, who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RF Online
''RF Online'', originally named 'Rising Force', ( ko, 라이징 포스) is a 3D MMORPG developed by CCR. The first version of the game was released in South Korea and was later followed by Chinese (Mandarin), Japanese, Indonesian, Portuguese and English translations. The North American/European version of the game launched its retail phase on February 21, 2006. A mixture of science fiction and classic fantasy Fantasy is a genre of speculative fiction involving magical elements, typically set in a fictional universe and sometimes inspired by mythology and folklore. Its roots are in oral traditions, which then became fantasy literature and d ..., ''RF Online'' is set in a distant planet in the Novus system where magic exists alongside high technology. Like most MMORPGs it follows the typical fantasy setting complete with swords and sorcery, but it also emphasizes the three-way Race vs. Race vs. Race (RvRvR) concept and modern/futuristic technology such as mecha and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodesian Front
The Rhodesian Front was a right-wing conservative political party in Southern Rhodesia, subsequently known as Rhodesia. It was the last ruling party of Southern Rhodesia prior to that country's unilateral declaration of independence, and the ruling party of Rhodesia from 1965 until 1979. Led first by Winston Field, and, from 1964, by Ian Smith, the Rhodesian Front was the successor to the Dominion Party, which was the main opposition party in Southern Rhodesia when that territory was a part of the Federation of Rhodesia and Nyasaland. The RF was formed in March 1962 by conservative white Rhodesians who opposed regional decolonisation and majority rule. It carried the general election in Southern Rhodesia that December, and remained in power until 1979. History and ideology The RF had fifteen founding principles, which included the preservation of each racial group's right to maintain its own identity, the preservation of 'proper standards' through a policy of advancement t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheumatoid Factor
Rheumatoid factor (RF) is the autoantibody that was first found in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG and different RFs can recognize different parts of the IgG-Fc. RF and IgG join to form immune complexes that contribute to the disease process. Rheumatoid factor can also be a cryoglobulin (antibody that precipitates on cooling of a blood sample); it can be either type 2 (monoclonal IgM to polyclonal IgG) or type 3 (polyclonal IgM to polyclonal IgG) cryoglobulin. Although ''predominantly'' encountered as IgM, rheumatoid factor can be of any isotype of immunoglobulins, i.e. IgA, IgG, IgM, IgE, IgD. Testing RF is tested by collecting blood in a plain tube (5 mL is often enough). The serum is tested for the presence of RF. There are different methods available, which include nephelometry, turbidimetry, agglutination of gamma globulin-coated latex particles or erythrocytes. RF is often evaluated in patients suspected of having any f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiative Forcing
Radiative forcing (or climate forcing) is the change in energy flux in the atmosphere caused by natural or anthropogenic factors of climate change as measured by watts / metre2. It is a scientific concept used to quantify and compare the external drivers of change to Earth's energy balance. System feedbacks and internal variability are related concepts, encompassing other factors that also influence the direction and magnitude of imbalance. Positive radiative forcing means Earth receives more incoming energy from sunlight than it radiates to space. This net gain of energy will cause warming. Conversely, negative radiative forcing means that Earth loses more energy to space than it receives from the sun, which produces cooling. A planet in radiative equilibrium with its parent star and the rest of space can be characterized by net zero radiative forcing and by a planetary equilibrium temperature. Radiative forcing on Earth is meaningfully evaluated at the tropopause and at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pacific and Indian Oceans. Its Metropolitan France, metropolitan area extends from the Rhine to the Atlantic Ocean and from the Mediterranean Sea to the English Channel and the North Sea; overseas territories include French Guiana in South America, Saint Pierre and Miquelon in the North Atlantic, the French West Indies, and many islands in Oceania and the Indian Ocean. Due to its several coastal territories, France has the largest exclusive economic zone in the world. France borders Belgium, Luxembourg, Germany, Switzerland, Monaco, Italy, Andorra, and Spain in continental Europe, as well as the Kingdom of the Netherlands, Netherlands, Suriname, and Brazil in the Americas via its overseas territories in French Guiana and Saint Martin (island), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regions Financial Corporation
Regions Financial Corporation is a bank holding company headquartered in the Regions Center in Birmingham, Alabama. The company provides retail banking and commercial banking, trust, stockbrokerage, and mortgage services. Its banking subsidiary, Regions Bank, operates 1,952 automated teller machines and 1,454 branches in 16 states in the Southern and Midwestern United States. Regions is ranked 434th on the Fortune 500 and is component headquartered in Alabama. Regions is also on the list of largest banks in the United States. Regions is the largest deposit holder in Alabama and Tennessee. It is also one of the largest deposit holders in Arkansas, Louisiana, Mississippi, and Florida. The company sponsors Regions Field, a Minor League Baseball stadium in Birmingham, Alabama, and the Tradition golf tournament. It sponsored the Regions Charity Classic, a golf tournament held in 2009 and 2010. The company has a partnership with Operation HOPE, Inc., to provide free financial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheumatic Fever
Rheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection. Signs and symptoms include fever, multiple painful joints, involuntary muscle movements, and occasionally a characteristic non- itchy rash known as erythema marginatum. The heart is involved in about half of the cases. Damage to the heart valves, known as rheumatic heart disease (RHD), usually occurs after repeated attacks but can sometimes occur after one. The damaged valves may result in heart failure, atrial fibrillation and infection of the valves. Rheumatic fever may occur following an infection of the throat by the bacterium '' Streptococcus pyogenes''. If the infection is left untreated, rheumatic fever occurs in up to three percent of people. The underlying mechanism is believed to involve the production of antibodies against a person's own tissues. Due to their genetics, some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reticular Formation
The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation make up a complex set of networks in the core of the brainstem that extend from the upper part of the midbrain to the lower part of the medulla oblongata. The reticular formation includes ascending pathways to the cortex in the ascending reticular activating system (ARAS) and descending pathways to the spinal cord via the reticulospinal tracts. Neurons of the reticular formation, particularly those of the ascending reticular activating system, play a crucial role in maintaining behavioral arousal and consciousness. The overall functions of the reticular formation are modulatory and premotor, involving somatic motor control, cardiovascular control, pain modulation, sleep and consciousness, and habituation. The modulatory functions are pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
