Allelefrequency or Gene frequency is the proportion of all copies of a gene that is made up of a particular gene variant allele . In other words, it is the number of copies of a particular allele divided ... in a copies then the allelefrequency is the fraction or percentage of all the occurrences of that locus that is occupied by a given allele and the frequency of one of the alleles is a n N . For example, if the frequency of an allele is 20 in a given population, then among population members, one ... an allele that has a frequency of 20 . However, alleles distribute randomly only under certain assumptions ... gene often are graphed together as an allelefrequency distribution histogram , or allelefrequency ... at a locus genetics locus with two alleles, then the frequency p of the A allele and the frequency ... frequency of A math Similarly, the frequency q of the a allele is given by math q f mathbf aa frac ... different allelic forms, the frequency for each allele is simply the frequency of its homozygote plus half the sum of the frequencies for all the heterozygotes in which it appears. Allelefrequency can ... a during the DNA replication preceding meiosis . If math p t math is the frequency of the A allele in generation t , then math q t 1 p t math is the frequency of the a allele in generation ... in allelefrequency in one generation is math Delta p p t p t 1 left p t 1 acute u p ... Allelefrequency net database External links http alfred.med.yale.edu alfred ALFRED database http ... vWA 17 A1.rar VWA 17 AlleleFrequency in Human Population Poster http www.allelefrequencies.net ... JR, Pakstis AJ, Miller PL, Kidd KK title ALFRED an allelefrequency database for diverse populations ... L, Rood H, Komerofsky R title New allelefrequency database http www.allelefrequencies.net journal ... al lica simple Allelefrequency sv Genfrekvens tr Gen frekans zh ... . It can be expressed for example as a percentage . In population genetics , allele frequencies are used ... more details
Minor allelefrequency MAF refers to the frequency at which the less common allele occurs in a given population. SNPs with a minor allelefrequency of 5 or greater were targeted by the HapMap project. MAF is widely employed in Genome wide association study Genome Wide Association studies for complex traits. Category Classical genetics genetics stub ... more details
infobox biodatabase title Allelefrequency net logo File Database.png description online repository for immune gene frequencies in worldwide populations. scope organism Homo sapiens center University of Liverpool laboratory Institute of Infection and Global Health author pmid PMID 21062830 released 2010 standard format url http www.allelefrequencies.net download webservice sql sparql webapp standalone license versioning frequency curation bookmark The allelefrequency net database is a database containing the frequencies of immune genes and their corresponding alleles in different populations. ref cite journal quotes yes last Gonzalez Galarza first Faviel F authorlink coauthors Christmas Stephen, Middleton Derek, Jones Andrew R year 2011 month Jan title Allelefrequency net a database and online repository for immune gene frequencies in worldwide populations journal Nucleic Acids Res. volume 39 issue Database issue pages D913 9 publisher location England issn pmid 21062830 doi 10.1093 nar gkq1128 bibcode oclc id url language eng format accessdate laysummary laysource laydate quote ref References references See also Allelefrequency External links http www.allelefrequencies.net Biodatabase stub Category Biological databases Category Immunology Category Genetics Category Population genetics ... more details
q 1 , math math p 2 2pq q 2 1 , math where p is the frequency of one allele and q is the frequency of the alternative allele, which necessarily sum to unity. Then, p sup 2 sup is the fraction of the population homozygous for the first allele, 2 pq is the fraction of heterozygotes, and q sup 2 sup is the fraction homozygous for the alternative allele. If the first allele is dominant to the second, then the fraction ... http alfred.med.yale.edu alfred index.asp ALFRED The ALleleFREquency Database http www.ehstrafd.org EHSTRAFD.org Earth Human STR Allele Frequencies Database Category Classical genetics Category Genetic ... metal band Allele band An allele IPAc en icon uk l i l or IPAc en us l i l is one ... organisms have one copy of each gene and therefore one allele on each chromosome. If both alleles ... with two different A alleles. The word allele is a short form of allelomorph other ... resembles. Where the heterozygote is indistinguishable from one of the homozygotes, the allele involved ... are modeled by Quantitative trait locus polygenic inheritance . The term wild type allele is sometimes used to describe an allele that is thought to contribute to the typical phenotypic character ... type allele was historically regarded as dominant, common, and normal , in contrast to mutant ... were homozygous for the wild type allele at most gene loci, and that any alternative mutant allele was found in homozygous form in a small minority of affected individuals, often as genetic diseases , and more frequently in heterozygous form in Genetic carrier carriers for the mutant allele ... in the form of alleles that do not produce obvious phenotypic differences. Allele and genotype frequencies The frequency of alleles in a population can be used to predict the frequencies of the corresponding ..., such as Huntington disease , occur when an individual inherits only one dominant allele. See ... it Allele he jv Alel kk ht Al l ku Allel lv Al le lt Aleliniai genai hu All l ... more details
A fixed allele is an allele that is the only variant that exists for that gene in all the population . A fixed allele is homozygous for all members of the population. ref http www.biochem.northwestern.edu holmgren Glossary Definitions Def F fixed allele.html ref The term allele normally refers to one variant gene out of several possible for a particular locus genetics locus in the DNA. When all but one allele go extinct and only one remains, that allele is said to be fixed. References references genetics stub Category Genetics ... more details
Unreferenced date December 2009 A null allele is a mutant allele copy of a gene that completely lacks that gene s normal function. This can be the result of the complete absence of the gene product protein, RNA at the molecular level, or the expression of a non functional gene product. At the phenotype phenotypic level, a null allele is indistinguishable from a deletion of the entire locus genetics locus . A mutant allele that produces no protein is called a protein null shown by Western blot western analysis , and one that produces no RNA is called an RNA null shown by Northern blot Northern analysis or by DNA sequencing of a deletion allele . A genetic null or Muller s morphs amorph ic allele has the same phenotype when homozygous as when heterozygous with a deficiency that disrupts the locus in question. A genetic null allele can be a protein and RNA null, but can also express normal levels of a gene product that is non functional due to mutation. Another definition of null allele concerning molecular markers, refers to such a marker in the case it can no longer be detected because of a mutation. For example, Microsatellite genetics microsatellite s i.e. a repetitive sequence of DNA, in which the repeat is rather short are used as molecular markers amplifying them through Polymerase ... be used and the allele is turned into a null allele. One example of a null allele is the O blood type allele in the human A, B and O blood types blood type system . The alleles for the A antigen ... if both are present. The allele for O blood type, however, is a mutated version of the allele ... allele is enzymatically inactive and therefore the O allele is expressed phenotypically in Zygosity homozygous OO individuals as the lack of any blood antigen. Thus we may consider the allele for the O blood type as a null allele. See also Muller s morphs amorph Genetic deletion RecLOH Unique event polymorphism DEFAULTSORT Null Allele Category Classical genetics de Nullallel es Alelo nulo ... more details
Infobox musical artist See Wikipedia WikiProject Musicians name Allele image caption image size 220 background ... br Mason Romaine Allele pronounced Uh Leel is an United States American alternative metal band from ... Tobin bass , Nathan Grimes drums . The band is currently signed to Goomba Music. To date, Allele has released two studio albums, Point of Origin Allele album Point of Origin in 2005 and Next to Parallel in 2011. History Allele was formed in 2002 by Wally Wood singer Wally Wood and ex Otep guitarist ... started to work on their debut Long Play LP titled Point of Origin Allele album Point of Origin ... band Bleed the Sky . Allele describes their sound as hard rock with a new feel and Point of Origin ... Switched and A New Revolution featuring ex Unloco frontman Joey Duenas . Allele has been voted 5 ..., The Jacknife and the Red Death. On June 29, 2006, it was revealed via Allele s MySpace blog that vocalist ...?mode Article&newsitemID 54441 BLABBERMOUTH.NET ALLELE Part Ways With Singer, Announce Replacement June 30, 2006 ref Allele would spend the rest of the fall touring with 10 Years band 10 Years and Evans ... BLABBERMOUTH.NET ALLELE To Tour With 10 YEARS, EVANS BLUE Aug. 8, 2006 ref ref http www.roadrunnerrecords.com blabbermouth.net news.aspx?mode Article&newsitemID 56659 BLABBERMOUTH.NET ALLELE Announces More Tour Dates With 10 YEARS, EVANS BLUE Aug. 17, 2006 ref Allele s track Stitches song Stitches ... Article&newsitemID 52356 BLABBERMOUTH.NET ALLELE Music Featured In TNT s Nightmares & Dreamscapes May ..., it was announced by a close friend of the band that Allele had broken up. This has since been confirmed ... remaining members. Frontman Wally Wood of the Jacksonville, Florida based hard rockers Allele has ... for Allele. Well, first step is, the first show we will play is August 30 at Freebird remix Live in Jacksonville ... their debut album Point of Origin Allele album Point of Origin . Songs performed included Immune Stitches .... On September 4, 2009, Allele streamed a preview of their upcoming new album. ref http tunelab.com ... more details
notability Music date March 2010 unreferenced date March 2010 This is a discography of the United States American alternative metal band Allele band Allele . Includes one studio album and two single. Albums Studio albums class wikitable align center Album information align left Point of Origin Allele album Point of Origin Released October 25, 2005 small U.S. small Label Corporate Punishment Records Corporate Punishment US Sales 178,000 Singles Closer to Habit, Stitches Singles class wikitable rowspan 2 Year rowspan 2 Title colspan 2 Peak chart positions rowspan 2 Album style width 3em font size 75 Hot Modern Rock Tracks U.S. br Mod br style width 3em font size 75 Hot Mainstream Rock Tracks U.S. br Main br valign top 2005 align left valign top Closer to Habit align center valign top align center valign top rowspan 2 Point of Origin valign top rowspan 1 2006 align left valign top Stitches align center valign top align center valign top valign top rowspan 1 2011 align left valign top Let It Go align center valign top align center valign top rowspan 1 Next to Parallel align center colspan 20 style font size 8pt denotes a release that did not chart. Music videos class wikitable Year Title Director s rowspan 1 2005 Closer to Habit Don Tylor Song appearances in media and soundtracks In 2006, Allele contributed Stitches to the THQ video game WWE Smackdown vs Raw 2007 and was featured in trailers and promos for TNT TV channel TNT s Stephen King anthology series, Nightmares and Dreamscapes . External links http www.alleleonline.com www.alleleonline.com Allele DEFAULTSORT Allele Discography Category Discographies of American artists Category Heavy metal groups discographies ... more details
Unreferenced date January 2007 orphan date November 2009 An Allele chart more commonly called a grid chart is a type of chart that shows the interaction of two data points at the grid intersection of their respective axes. The most common example of such a chart is from the multiplication table chart taught in many United States elementary schools , though the actual origins of this type of chart stem from genetics . Category Charts Genetics stub ... more details
frequency top to highest frequency bottom . f is the frequency in hertz Hz , meaning the number of cycles ... are reciprocal mathematics reciprocals . Frequency is the number of occurrences of a repeating event per unit time . It is also referred to as temporal frequency . The period is the duration of one turn geometry cycle in a repeating event, so the period is the reciprocal mathematics reciprocal of the frequency. For example, if a newborn baby s heart beats at a frequency of 120 times a minute, its ... processes, such as rotation , oscillation s, or wave s, frequency is defined as a number of cycles per unit time. In physics and engineering disciplines, such as optics , acoustics , and radio , frequency ... SI units, the unit of frequency is the hertz Hz , named after the German physicist Heinrich Hertz ... by one cycle, and is the reciprocal mathematics reciprocal of the frequency f math T frac 1 f math ... than those above. The horizontal axis represents time. By counting Calculating the frequency of a repeating ... within 15 seconds the frequency is math f frac 71 15 , mbox sec approx 4.7 , mbox hertz , math If the number ... an average error in the calculated frequency of f 1 2 T sub m sub , or a fractional ... interval and f is the measured frequency. This error decreases with frequency, so it is a problem ... the frequency of rotating or vibrating objects is to use a stroboscope . This is an intense repetitively flashing light strobe light whose frequency can be adjusted with a calibrated timing circuit. The strobe light is pointed at the rotating object and the frequency adjusted up and down. When the frequency of the strobe equals the frequency of the rotating or vibrating object, the object completes ... when illuminated by the strobe the object appears stationary. Then the frequency can be read from the calibrated ... multiple of the strobing frequency will also appear stationary. By frequency counter Higher frequencies are usually measured with a frequency counter . This is an electronic instrumentation electronic ... more details
Infobox musical artist name The Frequency image image size 220 caption From left to right Marc Cazorla, Alex Stiff background group or band origin Los Angeles , California , United States genre Indie rock , Electronica , Ambient music Ambient years active 2005 present label Ropeadope Records br Trussed website http www.thefrequencymusic.net Official Website current members Marc Cazorla br Alex Stiff br Mark Quinn The Frequency are an independent rock band from Los Angeles, CA. Marc Cazorla and Alex Stiff are the core songwriting and recording duo behind the music and use an array of analog and vintage instruments in creating sounds that have been described by NME as stripped back music strengthened by simplicity as much as beauty . Q Magazine has given the new release Morning to 3 A.M. 3 out of 4 stars and hails the band as able to form perfectly crafted Air like synth pop while also stretching their wings on the 17 minute ever shifting psych rock track Ego Is the Drug 3 A.M. The Frequency have recently signed a worldwide publishing deal with http www.chrysalismusic.co.uk Chrysalis Music in the UK and the song Jim Gordon Part II has been heard all over the globe due to being licensed for a yearlong BlackBerry television commercial campaign. Music from The Frequency can also be found ... Daily newspaper to declare The Frequency should be on every rock fan s radar. The Frequency s Jim Gordon ... Machine self release 2007 The Frequency EP Ropeadope Digital Compilations Explorations Classic Picante ... Free Download Oct 09 http www.nme.com reviews the frequency 10684 NME Review July 09 http www.dmcupdate.com ... External links http www.thefrequencymusic.net The Frequency s official website http www.myspace.com thefrequencymusic The Frequency s myspace http www.facebook.com pages The Frequency 5877798251?ref mf The Frequency on Facebook http www.twitter.com the frequency The Frequency on Twitter http absenceofgiants.com www.absenceofgiants.com DEFAULTSORT Frequency, The Category American indie rock groups ... more details
10 10 ref http www.411mania.com music album reviews 855 Allele 96 Point Of Origin Review.htm 411Mania ... allele pointoforigin.html Shakefire review ref rev7 FoundryMusic.com rev7score Rating 3 5 ref http ... Point Of Origin is the first studio album by the alternative metal band Allele band Allele ... and Allele s record label gave the band a lot of creative freedom. He had a lot of great ideas on the vocal ...?fljournal?FEMU&coll 5 Allele Record new album mlive.com .Retrieved on March 24, 2010. ref Track listing Tracklisting writing credits yes title1 Fake writer1 Allele length1 2 56 title2 A Different Someone writer2 Allele length2 3 28 title3 Closer to Habit writer3 Allele length3 3 19 title4 Stitches writer4 Allele length4 3 08 title5 Lost In Your Words writer5 Allele length5 3 33 title6 Tightrope writer6 Allele length6 3 45 title7 Immune writer7 Allele length7 4 14 title8 Lies writer8 Allele length8 3 14 title9 Misunderstood writer9 Allele length9 2 38 title10 Unknown writer10 Allele ... Records http www.alleleonline.com Official Allele Website Allele DEFAULTSORT Point Of Origin Album Category 2005 albums Category Allele albums Category Debut albums fa ... more details
An allele specific oligonucleotide ASO is a short piece of synthetic DNA complementary to the sequence of a variable target DNA. It acts as a Hybridization probe probe for the presence of the target in a Southern blot assay or, more commonly, in the simpler Dot blot assay. It is a common tool used in genetic testing , forensics , and Molecular Biology research. An ASO is typically an oligonucleotide of 15&ndash 21 nucleotide nucleotide bases in length. It is designed and used in a way that makes it specific for only one version, or allele , of the DNA being tested. The length of the ASO, which strand it is chosen from, and the conditions by which it is Nucleic acid hybridization bound to and washed from the target DNA all play a role in its specificity. These probes can usually be designed to detect a difference of as little as 1 base in the target s genetic sequence, a basic ability in the assay of single nucleotide polymorphism s SNPs , important in genotype genotype analysis and the Human Genome Project . To be detected after it has bound to its target, the ASO must be labeled with a radioactive ... RB Discrimination among the human beta A, beta S, and beta C globin genes using allele specific ... its non target allele leading to weaker interaction . The first diagram shows how the S probe is fully ... the normal A allele, while samples 3 and 5 have both the A and S alleles and are therefore Zygosity Heterozygous heterozygous Genetic carrier carriers of this Dominance relationship Recessive allele recessive mutation . Samples 2 and 6 have only the S allele, and would be affected by the disease ... been adapted to detect polymorphisms, as Variants of PCR allele specific PCR . However, the simplicity ... RB Detection of sickle cell beta S globin allele by hybridization with synthetic oligonucleotides. Proc ... amplified beta globin and HLA DQ DNA with allele specific oligonucleotide probes Nature ... Image of ASO autoradiogram DEFAULTSORT Allele Specific Oligonucleotide Category DNA profiling ... more details
Unreferenced date December 2009 In population genetics , the genotype frequency is the frequency or proportion i.e. 0 f 1 of genotype s in a population . It may be denoted thus math f mathbf AA math or alternatively H 1, H 2 H 3 eek I think Compare allelefrequency . The Hardy Weinberg law predicts genotype frequencies from allele frequencies under certain conditions, in which case math f mathbf AA p 2 math math f mathbf Aa 2pq math math f mathbf aa q 2 math Genotype frequencies may be represented by a De Finetti diagram . DEFAULTSORT Genotype Frequency Category Population genetics es Frecuencia genot pica it Frequenza del genotipo hu Genot pus gyakoris g zh ... more details
Normalized frequency can refer to Normalized frequency digital signal processing Normalized frequency fiber optics , also known as V number Disambig ... more details
Frequency conversion may refer to different processes affecting frequency of physical phenomena A frequency changer is an electronic device that converts alternating current AC of one frequency to alternating current of another frequency. A variable frequency drive is a type of frequency changer Frequency conversion in nonlinear optics may refer to various manipulations of the frequency of light. A Hetrodyne is used in signal electronics to convert frequencies. disambig ... more details
In telecommunication , frequency sharing is the assignment to or use of the same radio frequency by two or more stations that are separated geographically or that use the frequency at different times. Frequency sharing reduces the potential for mutual radio frequency interference interference where the assignment of different frequencies to each User telecommunications user is not practical or possible. In a communications net , frequency sharing does not pertain to stations that use the same frequency. References FS1037C Category Bandplans telecomm stub ar ... more details
Single frequency may refer to Single Frequency Approach , a service for a military single piloted turbojet aircraft to use a single UHF frequency during their landing approach Single frequency network , a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel Single frequency signaling , line signaling in which dial pulses or supervisory signals are conveyed by a single voice frequency tone in each direction disambig ... more details
In the physical sciences and in telecommunication , the term frequency shift has the following meanings Any change in frequency A Doppler shift Any change in the frequency of a radio transmitter or electronic oscillator oscillator . Note In the radio regime, frequency shift is also called rf shift. Frequency shift telegraphy In Fax facsimile , a frequency modulation system where one frequency represents picture black and another frequency represents picture white . Frequencies between these two limits may represent shades of gray An intentional frequency change used for modulation purposes FS1037C MS188 disambig ... more details
wiktionary frequencyFrequency refers to how often an event occurs within a period of time. Frequency may also refer to tocright General Audio frequency , a periodic vibration whose frequency is audible to the average human Statistical frequency , the number of times an event occurred in an experiment or the study Utility frequency or mains frequency , the frequency of an alternating current electricity supply Frequency spectrum , a continuum of vibrations of varying amplitude such as sound or light Popular culture Frequency film Frequency film , a 2000 film starring Jim Caviezel and Dennis Quaid FM4 Frequency Festival , an Austrian music festival Frequency radio station Frequency radio station , a student radio station based in Preston, England Frequency video game Frequency video game , a 2001 music video game Frequency Nick Gilder album Frequency Nick Gilder album , 1979 Frequency IQ album Frequency IQ album , 2009 Frequencies album Frequencies album , a 1991 album by electronic band LFO Frequency , a song by Super Furry Animals from their album Love Kraft Frequency producer born 1983 , New York based music producer and DJ Medical Urinary frequency , a medical term used to describe the frequent passing of small amounts of urine See also Periodicity disambiguation disambiguation ca Freq ncia desambiguaci da Frekvens flertydig de Frequency fr Fr quence homonymie lt Da nis reik m s nl Frequency nn Frekvens pt Frequ ncia desambigua o sk Frekvencia ... more details
Transition frequency may refer to A measure of the Gain bandwidth product Transistors high frequency operating characteristics of a transistor, usually symbolized as math f sub T sub A characteristic of spectral line s The frequency at which changes in the hyperfine structure of atoms occur Turnover number Turnover frequency in enzymology disambig ... more details
Carrier frequency is a term used to designate The nominal frequency of a carrier wave The center frequency of a frequency modulation signal The frequency of the unmodulated electrical wave at the output of an amplitude modulated AM , frequency modulated FM or phase modulated PM transmitter The output of a transmitter when the modulation is zero The rate of occurrence within a population of a chromosome that causes a genetic disorder Category Telecommunications terms Category Modems disambig ... more details
The term, frequency dependence is applied, or referred to in the following articles In Chemical synapse ... succession a phenomenon that gives rise to the so called frequency dependence of synapses. Common source Usually the frequency dependence of the gain v D v G is unimportant for frequencies even somewhat above the corner frequency of the ... Dielectric frequency dependence of the susceptibility leads to frequency dependence of the permittivity. Dispersion optics discusses cases of frequency dependence ... to frequency dependence effects in wave propagation. Also, there are the overarching Kramers Kronig relations that connect the frequency dependence of propagation and attenuation Evolutionary invasion analysis incorporates the concept of frequency dependence from game theory but allows for more ... Kronig relation s, which place limitations upon the form of the frequency dependence. ... Electrical impedance myography phase can be plotted as a function of frequency to demonstrate the differences in frequency dependence between healthy and diseased groups. ... Frequency dependent selection ... on its frequency . Gain bandwidth product According to S. Srinivasan t he parameter characterizing the frequency ... coefficient, typically represented by an , has no wavelength or frequency dependence for the frequency range being worked in. Intrinsic viscosity section entitled Frequency dependence The intrinsic viscosity formula may also be generalized to include a frequency dependence. Metamaterial some properties of metamaterials are related to frequency dependence Miller effect accounts for the increase ... of the capacitance between the input and output terminals. Opacity optics More extreme frequency dependence is visible in the absorption line s of cold gases. Permittivity frequency dependence of the susceptibility leads to frequency dependence of the permittivity. Photon The model accounted for the frequency dependence of light s energy... Pole splitting is a phenomenon exploited in some forms of frequency ... more details
Frequency deviation f is used in Frequency modulation FM radio to describe the maximum instantaneous difference between an FM modulated frequency and the Center frequency nominal carrier frequency . The term is sometimes mistakenly used as synonymous with frequency drift , which is an unintended offset of an oscillator from its nominal frequency. The frequency deviation of a radio is of particular importance in relation to Bandwidth signal processing bandwidth , because less deviation means that more channels can fit into the same amount of frequency spectrum . The FM broadcasting range 88 108 MHz uses a channel spacing of 200 kHz, with a maximum frequency deviation of 75 kHz, leaving a 25 kHz buffer above the highest and below the lowest frequency to reduce interaction with other channels. ref http hyperphysics.phy astr.gsu.edu hbase audio radio.html ref AM broadcasting uses a channel spacing of 10 kHz, but with amplitude modulation frequency deviation is irrelevant. FM applications use peak deviations of 75 kHz 200 kHz spacing , 5 kHz 25 kHz spacing , 2.25 kHz 12.5 kHz spacing , and 2 kHz 8.33 kHz spacing . ref http www.rsgb spectrumforum.org.uk Papers VHF Davos 20C5 20Papers DV05 C5 17 20SARL 20NBFM.pdf ref See also Frequency modulation References FS1037C MS188 reflist Category Telecommunications it Deviazione di frequenza pl Dewiacja cz stotliwo ci ru ... more details
A frequency standard is a stable electronic oscillator oscillator used for frequency calibration or reference. A frequency standard generates a fundamental frequency with a high degree of accuracy and precision . Harmonics of this fundamental frequency are used to provide reference points. Since time is the reciprocal of frequency, it is relatively easy to derive a time standard from a frequency standard. A standard clock comprises a frequency standard, a device to count off the cycles of the oscillation emitted by the frequency standard, and a means of displaying or outputting the result. Frequency standards in a telecommunications network network or Telecommunications facility facility are sometimes administratively designated as primary or secondary . The terms primary and secondary , as used in this context, should not be confused with the respective technical meanings of these words in the discipline of precise time and frequency. Frequency reference A frequency reference is an instrument used for providing a stable frequency of some kind. There are different sorts of frequency references, acoustics acoustic ones such as tuning fork s but also electrical ones that emit a signal of a certain frequency a frequency standard . Among the most stable frequency references in the world are caesium standard s, including Caesium fountain caesium fountains , and hydrogen maser s. Caesium standards are widely recognized as having better long term stability, whereas hydrogen masers can attain superior short term performance therefore, several national Measurement standards laboratory standards laboratories use ensembles of caesium standards and hydrogen masers in order to combine the best attributes of both. The carrier of time signal transmitters, LORAN LORAN C transmitters and of several ... used as frequency standard. References FS1037C MS188 See also Rubidium standard DEFAULTSORT Frequency Standard Category Electronics standards de Normalfrequenz ru ... more details
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