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Histone H4
Histone H4 is one of the five main histone proteins involved in the structure of chromatin in eukaryote, eukaryotic cells. Featuring a main globular domain and a long N-terminus, N-terminal tail, H4 is involved with the structure of the nucleosome of the 'beads on a string' organization. Histone proteins are highly post-translationally modified. Covalently bonded modifications include acetylation and methylation of the N-terminal tails. These modifications may alter Gene expression, expression of genes located on DNA associated with its parent histone octamer. Histone H4 is an important protein in the structure and function of chromatin, where its sequence variants and variable modification states are thought to play a role in the dynamic and long term regulation of genes. Genetics Histone H4 is encoded in multiple genes at different loci including: HIST1H4A, HIST1H4B, HIST1H4C, HIST1H4D, HIST1H4E, HIST1H4F, HIST1H4G, HIST1H4H, HIST1H4I, HIST1H4J, HIST1H4K, HIST1H4L, HIST2H4A, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H4 (chronometer)
John Harrison ( – 24 March 1776) was an English carpenter and clockmaker who invented the marine chronometer, a long-sought-after device for solving the problem of how to calculate longitude while at sea. Harrison's solution revolutionized navigation and greatly increased the safety of long-distance sea travel. The problem he solved had been considered so important following the Scilly naval disaster of 1707 that the British Parliament was offering financial rewards of up to £20,000 (equivalent to £ in ) under the 1714 Longitude Act, though Harrison never received the full reward due to political rivalries. He presented his first design in 1730, and worked over many years on improved designs, making several advances in time-keeping technology, finally turning to what were called sea watches. Harrison gained support from the Longitude Board in building and testing his designs. Towards the end of his life, he received recognition and a reward from Parliament. Early life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoom H4 Handy Recorder
The H4 Handy Recorder is a handheld digital audio recorder from Zoom, featuring built-in condenser microphones in an X-Y stereo pattern, priced from around US$280 depending upon memory capacity . Recordings are stored on an SD card (128 MB supplied), or via a USB cable to a computer running digital audio workstation software (Cubase LE supplied). Applications and recording formats The H4 can record in stereo or four-track mode. In stereo mode WAV or compressed (MP3) files may be made. A 2 GB card will store 95 hours of speech-quality or 3 hours of CD-quality recording. With device firmware from version 2.0, SDHC cards up to 32 GB in size are supported, storing 16 hours at the highest-quality setting (uncompressed PCM WAV, 24 bit, 96 kHz, stereo). Basic four-track recordings can be made in the field with the built-in microphones and two additional input ports which accept external signal sources via XLR or 1/4-inch connectors. Stereo mode In stereo mode, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headlamp
A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in the most precise usage, ''headlamp'' is the term for the device itself and ''headlight'' is the term for the beam of light produced and distributed by the device. Headlamp performance has steadily improved throughout the automobile age, spurred by the great disparity between daytime and nighttime traffic fatalities: the US National Highway Traffic Safety Administration states that nearly half of all traffic-related fatalities occur in the dark, despite only 25% of traffic travelling during darkness. Other vehicles, such as trains and aircraft, are required to have headlamps. Bicycle headlamps are often used on bicycles, and are required in some jurisdictions. They can be powered by a battery or a small generator like a bottle or hub dynamo. History of automotive headlamps Origins The first horseless carriages used carriage lamps, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histamine H4 Receptor
The histamine H4 receptor, like the other three histamine receptors, is a member of the G protein-coupled receptor superfamily that in humans is encoded by the ''HRH4'' gene. Discovery Unlike the histamine receptors discovered earlier, H4 was found in 2000 through a search of the human genomic DNA data base. Tissue distribution H4 is highly expressed in bone marrow and white blood cells and regulates neutrophil release from bone marrow and subsequent infiltration in the zymosan-induced pleurisy mouse model. It was also found that H4 receptor exhibits a uniform expression pattern in the human oral epithelium. Function The Histamine H4 receptor has been shown to be involved in mediating eosinophil shape change and mast cell chemotaxis. This occurs via the βγ subunit acting at phospholipase C to cause actin polymerization and eventually chemotaxis. The histamine H4 receptor has been identified as a vital regulator of the immune system, involved in eosinophil migration, mast c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H4 Polytope
In 4-dimensional geometry, there are 15 uniform 4-polytope, uniform polytopes with H4 symmetry. Two of these, the 120-cell and 600-cell, are regular polytope, regular. Visualizations Each can be visualized as symmetric orthographic projections in Coxeter planes of the H4 Coxeter group, and other subgroups. The 3D picture are drawn as Schlegel diagram projections, centered on the cell at pos. 3, with a consistent orientation, and the 5 cells at position 0 are shown solid. Coordinates The coordinates of uniform polytopes from the H4 family are complicated. The regular ones can be expressed in terms of the golden ratio and . Coxeter expressed them as 5-dimensional coordinates.Coxeter, ''Regular and Semi-Regular Polytopes II'', ''Four-dimensional polytopes', p. 296–298 References * John Horton Conway, J.H. Conway and Michael Guy (computer scientist), M.J.T. Guy: ''Four-Dimensional Archimedean Polytopes'', Proceedings of the Colloquium on Convexity at Copenhagen, pag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS H4
HMS ''H4'' was a British H class submarine, British H-class submarine built by the Canadian Vickers Co., Montreal. She was laid down on 11 January 1915 and was commissioned on 5 June 1915. After her commissioning, HMS ''H4'' and sister ships , and crossed the Atlantic from St John's, Newfoundland and Labrador, St. John's, Newfoundland and Labrador, Newfoundland to Gibraltar being escorted by the armed merchant cruiser . ''H4'' sank the U-boat in the Adriatic on 23 May 1918. She was sold on 30 November 1921 in Malta. Design Like all pre-''H11'' British H-class submarines, ''H4'' had a displacement of at the surface and while submerged. It had a total length of , a beam of , and a draught of . It contained a diesel engines providing a total power of and two electric motors each providing power. Retrieved froNaval-Historyon 20 August 2015. The use of its electric motors made the submarine travel at . It would normally carry of fuel and had a maximum capacity of . The sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H4 (film)
''H4'' is a 2012 independent American film directed by Paul Quinn; actor Harry Lennix produced the film and stars in the title role. The film premiered at the 2012 Conference of the Shakespeare Association of America,http://www.shakespeareassociation.org/wp-content/uploads/2013/06/bulletin0112.pdf and later showed premiere in competition at the 49th Chicago International Film Festival in 2013. In November 2014, the film was shown at the Indie Memphis Film Festival. Plot The film is an adaptation that combines William Shakespeare's plays ''Henry IV, Part 1'' and ''Henry IV, Part 2'' and sets them in contemporary Los Angeles. The screenplay was adapted by Dr. Ayanna Thompson, Professor of English at Arizona State University, retaining Shakespeare's original language. According to Lennix, the film is told "from the perspective of black people, acted primarily by black people, and it’s from the black point of view"; he nevertheless describes Shakespeare's themes, and the film's, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H4 (classification)
H4 is a para-cycling classification. The UCI recommends this be coded as MH4 or WH4. Definition Union Cycliste Internationale (UCI) defines H4 as: *Paraplegic with impairments corresponding to a complete lesion from Th11 or below * No lower limb function or limited function * Normal or almost normal trunk stability * Non-spinal cord injury, functional ability profile equivalent to sport class H4 (ex-H3) * Incomplete loss of lower limb function, functional ability profile equivalent to sport class H4 (ex-H3) or H5 (ex-H4), with other disabilities, which prevent the safe use of a conventional bicycle, tricycle or the Kneeling position in a handbike * Recumbent position in handbike (AP or ATP-bike) * Diplegia and athetosis/ataxia/dystonia (almost normal UE) Hemiplegic with spasticity a minimum of grade 3, lower limb more involved. The cycle This classification can use ATP3 knee-seat cycle that is forward leaning on a rigid frame. Classification history Cycling first became a Paral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H4 Dansteed Way
The Milton Keynes grid road system is a network of predominantly national speed limit, fully landscaped routes that form the top layer of the street hierarchy for both private and public transport in Milton Keynes, Buckinghamshire. The system is unique in the United Kingdom for its innovative use of street hierarchy principles: the grid roads run in between districts rather than through them. This arrangement permits higher speed limits due to the absence of buildings close to the roads, although more recently some have been limited in part to . The grid road system also serves an important purpose of discouraging through-traffic from travelling through neighbourhoods and thus reduces traffic noise and pollution in pedestrian areas. Motor traffic is segregated from pedestrian and leisure cycling traffic, which uses the alternative Milton Keynes redway system. Almost all grid junctions are roundabouts, and the absence of traffic lights (from most) enables free and efficient moveme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNR Class H4
The Great Northern Railway (Great Britain), Great Northern Railway Class H4 (classified K3 by the London and North Eastern Railway, LNER) was a class of 2-6-0 steam locomotive designed for mixed-traffic work. The type was a more powerful development of the earlier GNR Class H3, H3 (LNER Class K2, LNER K2) class and was notable at the time, as the boilers were the largest fitted to any British locomotive to that date. After formation of the London and North Eastern Railway, the type became known as class K3 and was adopted as an LNER standard design. They got the nickname "Jazzers" after the rhythm of their exhaust beat and the unbalanced gyratory movement. Construction The first ten locomotives were built at the GNR's Doncaster Works in 1920, to the design of Nigel Gresley. Six further batches were built at Doncaster and Darlington Works, Armstrong Whitworth, Robert Stephenson and Company and the North British Locomotive Company. The last few of 193 examples were delivered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
