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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

An Examination of Hardy-Weinberg Disequilibrium and Statistical Testing in Genetic Association Studies

Grover, Vaneeta Kaur 18 June 2010 (has links)
In an unpublished study in Toronto it was observed that cases were in Hardy-Weinberg Equilibrium at a locus whereas their family members were in Hardy-Weinberg Disequilibrium (HWD). This led to an investigation of relatives of affected individuals to see whether the multiplicative model could be revealed by a nonzero HWD coefficient in relatives. Genotypic frequencies and HWD coefficients were derived for affected individuals and their affected and unaffected relatives. Methods were also developed to test for association using data from affected individuals and their relatives. In addition, a model was developed to assess whether the HWD observed in a data set from a stratified population can be explained by both genetic association and stratification. Parameter estimates for these models can be obtained using maximum likelihood methods, and used to deduce the mode of inheritance of the disease. / Departure from HWE (HWD) in a sample may indicate genotyping error, population stratification, selection bias, or some combination thereof. Therefore, loci exhibiting HWD are often excluded from association studies. However, it has been shown that in case-control studies HWD can result from a genetic effect at the locus, and HWD at a marker locus can be interpreted as evidence for association with a disease. In an unpublished study in Toronto it was observed that cases were in Hardy- Weinberg equilibrium at a locus whereas their family members were in HWD. It has been shown that the HWD coefficient for a multiplicative genetic model is zero. This led to an investigation of relatives of affected individuals to see whether the multiplicative model could be revealed by a nonzero HWD coefficient in relatives. Genotypic frequencies and HWD coefficients were derived for affected individuals and their affected and unaffected relatives. A substantial HWD was found in both individuals in dominant and recessive genetic models but HWD is only slightly nonzero for additive and multiplicative models. Methods were also developed to test for association using data from affected individuals and their relatives. Parameter estimates for these models can be obtained using maximum likelihood methods, and estimates provide valuable information regarding the mode of inheritance of the disease. The methods were applied to 112 discordant sib pairs with Alzheimer’s disease typed for the ApoE polymorphism and a significant association was observed between the "4 ApoE allele and Alzheimer’s disease. Case-control studies may indicate spurious association with a marker locus in a stratified population. Methods were developed to determine if the HWD observed in a data set from a stratified population can be explained by both genetic association and stratification. Parameter estimates for these models can be obtained using maximum likelihood methods, and used to deduce the mode of inheritance of the disease. Applying the model to the R990G SNP of the CASR gene, it was found that the HWD was adequately explained by a recessive genetic association and a stratification proportion of 10%, consistent with the population of Toronto.
12

Theoretical and phenomenological aspects of vector boson production

Werthenbach, Anja January 2000 (has links)
The production of three gauge bosons in high-energy collisions - in particular in view of a next-linear collider with center of mass energies in the TeV range - offers an unique opportunity to probe the Standard Model (SM) of today's particle physics. In this thesis we pay particular attention to the electroweak sector of the theory. We investigate the gauge structure {i. e. possible deviations from the SM predictions of gauge boson self-interactions manifest e. g. in anomalous quartic gauge boson couplings and Radiation zeros) as well as electroweak radiative corrections in order to improve theoretical predictions for SM processes. Quartic gauge boson couplings can be regarded as a direct window on the sector of electroweak symmetry breaking. We have studied the impact of three such anomalous couplings on the processes e+e(^-) → WWγ, ZZγ and Zγγ at LEP2 and a future linear collider. In certain high-energy scattering processes involving charged particles and the emission of one or more photons, the scattering amplitude vanishes for particular configurations of the final state particles. The fact that gauge symmetry is a vital ingredient for the cancellation to occur means that radiation zeros can be used to probe physics beyond the standard model. For example anomalous electroweak gauge boson couplings destroy the delicate cancellation necessary for the zero to occur. We have studied the process qq → WWγ. To match the expected experimental precision at future linear colliders, improved theoretical predictions beyond next-to-leading order are required. By choosing an appropriate gauge, we have developed a formalism to calculate such corrections for arbitrary electroweak processes. As an example we consider here the processes e(^+)e → f f and e(^+)e(^-) → W(^+)(_T)W(^-)(_T), W(^+)(_L)W(^-)(_L) and study the perturbative structure of the electroweak Sudakov logarithms by means of an explicit two-loop calculation. In this way we investigate how the Standard Model, with its mass gap between the photon and Z boson in the neutral sector, compares to unbroken theories like QED and QCD. We observe that the two-loop corrections are consistent with an exponentiation of the one-loop corrections. In this sense the Standard Model behaves like an unbroken theory at high energies.
13

A study of Hardy-Weinberg equilibrium, linkage equilibrium, and population structure in Hispanics using seven genetic markers

Jones, Donald Thomas 01 January 1997 (has links)
No description available.
14

The analysis of twelve forensic DNA genetic markers for Hardy-Weinberg and gametic phase disequilibrium for a Caucasian data base

Gregonis, Daniel John 01 January 1997 (has links)
No description available.
15

PopGen Fishbowl: A Free Online Simulation Model of Microevolutionary Processes

Jones, Thomas C., Laughlin, Thomas F. 01 February 2010 (has links)
Natural selection and other components of evolutionary theory are known to be particularly challenging concepts for students to understand. To help illustrate these concepts, we developed a simulation model of microevolutionary processes. The model features all the components of Hardy-Weinberg theory, with population size, selection, gene flow, nonrandom mating, and mutation all being demonstrated in the simulations. By using this freely available computer model, students can develop and test hypotheses with replicated virtual experiments. Because the model is an agent-based simulation, there is biologically realistic variability in the results. Students using the model see results both numerically and graphically and these are reinforced by an animation of the virtual fish in the simulated experiment.
16

Use of Diplotypes - Matched Haplotype Pairs From Homologous Chromosomes - in Gene-Disease Association Studies

Zuo, Lingjun, Wang, Kesheng, Luo, Xingguang 01 June 2014 (has links)
Alleles, genotypes and haplotypes (combinations of alleles) have been widely used in gene-disease association studies. More recently, association studies using diplotypes (haplotype pairs on homologous chromosomes) have become increasingly common. This article reviews the rationale of the four types of association analyses and discusses the situations in which diplotype-based analyses are more powerful than the other types of association analyses. Haplotype-based association analyses are more powerful than allele-based association analyses, and diplotype-based association analyses are more powerful than genotype-based analyses. In circumstances where there are no interaction effects between markers and where the criteria for Hardy-Weinberg Equilibrium (HWE) are met, the larger sample size and smaller degrees of freedom of allele-based and haplotype-based association analyses make them more powerful than genotype-based and diplotype-based association analyses, respectively. However, under certain circumstances diplotype-based analyses are more powerful than haplotype-based analysis.
17

Arten und Biotope am Terrassenweinberg - am Beispiel des Terrassenweinbergs am Burgberg Meißen

Hardtke, Hans-Jürgen, Kuschka, Volkmar 28 January 2021 (has links)
Die vorliegende Broschüre soll dazu dienen, neben einem Einblick in die Geschichte der Pflanzenwelt des Meißner Burgbergs insbesondere die Artenvielfalt des Lebensraumes Terrassenweinberg mit Trockenmauern aufzuzeigen, wenn er in ökologischer Weise bewirtschaftet wird. Der Überblick über die häufigsten Arten kann dabei stellvertretend für die verschiedenen Biotope an Weinbauterrassen und Burgbergen stehen. Die Broschüre richtet sich an ein interessiertes Fachpublikum, aber auch an alle weiteren Freunde der Natur und unserer einmaligen Kulturlandschaft im Elbtal. Redaktionsschluss: 01.09.2015
18

族群達到哈溫比例及芮特比例的交配系統之整合性研究 / A Comprehensive Study of Mating Systems of a Population Attaining Hardy-Weinberg Proportions and Wright Proportions

黃崑明, Kuen-Ming Huang Unknown Date (has links)
在族群遺傳學中已知有許多因子影響基因型與對偶基因頻率,族群的交配方式即為其中之一。例如,哈溫平衡定律即指族群進行隨機交配,而芮特平衡定律所描述之自交系理論指的是族群進行了某種特定型式的非隨機交配。本文將以往討論過或未討論過之族群基因型頻率會達到哈溫比例及芮特比例的交配系統做一整合性研究。族群基因型頻率會達到哈溫比例或芮特比例之交配系統的整體架構將根據交配群體中雙親二子群體的交配行為、基因型頻率是否在哈溫比例及是否相同、對偶基因頻率是否相同來建立。整體架構中的每一構造點所對應的交配系統將被找出或證明不存在,若存在則會進一步討論其特性。 目 錄 摘要………………………………………………………………….. I ABSTRACT………………………………………………………… II 圖表目錄…………………………………………………………….. VII 第一章 緒論……………………………………………………….. 1 第二章 族群達到Hardy-Weinberg比例及Wright比例的交配系統之整體架構………………………………………….. 3 第三章 族群達到Hardy-Weinberg比例之隨機交配系統……... 6 3.1 基本定義與原理………………………………………………………. 6 3.1.1 基因型頻率與對偶基因頻率…………………………………… 6 3.1.2 隨機交配與非隨機交配………………………………………… 7 3.1.3 基因型隨機交配會導致配子隨機結合原理…………………... 7 3.1.4 平衡族群的交配系統之特性…………………………………… 8 3.2 雌雄二次群體之基因型頻率在相同的Hardy-Weinberg比例且其子代群體基因型頻率會達到Hardy-Weinberg比例的隨機交配系統 ………………………………………………………………… 9 3.3 雌雄二次群體之基因型頻率在不同的Hardy-Weinberg比例的隨機交配系統 其子代群體基因型頻率不會達到Hardy-Weinberg比例……………………………………………………….. 10 3.4 雌雄二次群體之基因型頻率不在Hardy-Weinberg比例但基因型及對偶基因頻率皆相同下其子代群體基因型頻率會達到Hardy-Weinberg比例的隨機交配系統 ……………………………….. 12 3.5 雌雄二次群體之基因型頻率不在Hardy-Weinberg比例且基因型頻率不同但對偶基因頻率相同下其子代群體基因型頻率會達到Hardy-Weinberg比例的隨機交配系統 ………………………. 13 3.6 雌雄二次群體之基因型頻率不在Hardy-Weinberg比例且基因型及對偶基因頻率皆不同的隨機交配系統 之子代群體基因型頻率不會達到Hardy-Weinberg比例………………………………. 14 3.7 隨機交配族群基因型頻率會達到Hardy-Weinberg比例的交配系統之結論與彙整………………………………………………………. 14 第四章 族群達到Hardy-Weinberg比例的隨機交配系統之性質 17 4.1 隨機交配系統 及其子代群體配子結合之相關係數…………... 17 4.1.1 隨機交配系統 之相關係數………………………………... 17 4.1.2 隨機交配系統 之子代群體配子結合的相關係數……….. 18 4.2 ITO方法及其應用……………………………………………………. 19 4.3 隨機交配系統 之親代和子代基因型聯合頻率矩陣及其相關係數. 21 4.3.1 隨機交配系統 之母子基因型聯合頻率矩陣及其相關係數... 20 4.3.2 隨機交配系統 之父子基因型聯合頻率矩陣及其相關係數... 23 4.3.3 隨機交配系統 之親子基因型聯合頻率矩陣及其相關係數... 24 4.4 隨機交配系統 之二同胞基因型聯合頻率矩陣及其相關係數.. 25 4.5 隨機交配族群基因型頻率達到Hardy-Weinberg比例的交配系統之性質比較……………………………………………………………. 27 第五章 母父子基因型的傳遞機率矩陣及其應用……………….. 28 5.1 母父子基因型的傳遞機率矩陣………………………………………. 28 5.2 子代群體基因型頻率之矩陣代數算法………………………………. 31 5.2.1 不區分異質結合基因型的子代群體基因型頻率……………... 32 5.2.2 區分異質結合基因型的子代群體基因型頻率………………... 33 5.3 親代和子代基因型聯合頻率之矩陣代數算法……………………… 34 5.3.1 母子基因型聯合頻率矩陣之矩陣代數算法…………………... 34 5.3.2 父子基因型聯合頻率之矩陣代數算法………………………… 35 5.4 二同胞基因型聯合頻率之矩陣代數算法…………………………… 36 第六章 族群達到Hardy-Weinberg比例之非隨機交配系統…... 41 6.1 雌雄二次群體之基因型頻率在Hardy-Weinberg比例且基因型及對偶基因頻率皆相同下其子代群體基因型頻率會達到Hardy-Weinberg比例的非隨機交配系統 …………………………….. 41 6.2 雌雄二次群體之基因型頻率不在Hardy-Weinberg比例且基因型與對偶基因頻率皆不同但其子代群體基因型頻率達到Hardy-Weinberg比例的非隨機交配系統 …………………………….. 44 6.3 非隨機交配系統 的另一種表示法……………………………… 46 6.4 雌雄二次群體之基因型頻率在Hardy-Weinberg比例但基因型及對偶基因頻率皆不同下其子代群體基因型頻率會達到Hardy-Weinberg比例的非隨機交配系統 …………………………….. 50 6.5 雌雄二次群體之基因型頻率不在Hardy-Weinberg比例但基因型及對偶基因頻率皆相同下其子代群體基因型頻率會達到Hardy-Weinberg比例的非隨機交配系統 …………………………….. 52 6.6 雌雄二次群體之基因型頻率不在Hardy-Weinberg比例且基因型頻率不同但對偶基因頻率相同下其子代群體基因型頻率會達到Hardy-Weinberg比例的非隨機交配系統 …………………… 53 6.7 非隨機交配族群基因型頻率會達到Hardy-Weinberg比例的交配系統之彙整……………………………………………………………. 54 第七章 族群達到Hardy-Weinberg比例的非隨機交配系統之性質……………………………………………………….. 56 7.1 雌雄交配基因型聯合頻率矩陣 之相關係數………………….. 56 7.2 之子代群體配子結合的相關係數……………………………… 58 7.3 之親代和子代基因型聯合頻率矩陣及其相關係數………….. 60 7.3.1 之母子基因型聯合頻率矩陣及其相關係數…………….. 61 7.3.2 之父子基因型聯合頻率矩陣及其相關係數…………….. 64 7.4 之二同胞基因型聯合頻率矩陣及其相關係數……………… 64 7.5 非隨機交配族群之子代群體基因型頻率達到Hardy-Weinberg比例的交配系統之性質比較…………………………………………… 69 第八章 族群達到Wright比例的交配系統及其性質……………. 71 8.1 Wright平衡定律……………………………………………………… 71 8.2 族群基因型頻率達到Wright比例的交配系統之最一般化型式 … 72 8.3 族群基因型頻率會達到Wright比例之交配系統的整體架構中其餘各交配系統之存在性………………………………………………. 77 8.3.1 雌雄二次群體之基因型頻率在Hardy-Weinberg比例且基因型及對偶基因頻率皆相同其子代群體基因型頻率會達到Wright比例的交配系統 …………………………………. 77 8.3.2 雌雄二次群體之基因型頻率不在Hardy-Weinberg比例但基因型及對偶基因頻率皆相同其子代群體基因型頻率會達到Wright比例的交配系統 …………………………………. 78 8.3.3 族群基因型頻率達到Wright比例的交配系統之彙整……….. 80 8.4 族群基因型頻率會達到Wright比例的交配系統之性質………… 82 8.4.1 雌雄交配基因型聯合頻率矩陣 之相關係數……………. 82 8.4.2 之親代和子代基因型聯合頻率矩陣及其相關係數……. 84 8.4.3.1 之母子基因型聯合頻率矩陣及其相關係數……… 84 8.4.3.2 之父子基因型聯合頻率矩陣及其相關係數………. 87 8.4.3 之二同胞基因型聯合頻率矩陣及其相關係數…………. 87 8.4.4 族群基因型頻率會達到Wright比例的交配系統之性質的結論與彙整………………………………………………………… 89 第九章 一般化平衡族群的交配系統及其性質………………….. 91 9.1 一般化平衡定律………………………………………………………. 91 9.2 非隨交配族群基因型頻率達到一般化比例的交配系統之最一般化型式 ……………………………………………………………… 93 9.3 雌雄二次群體之基因型頻率在Hardy-Weinberg比例但基因型與對偶基因頻率皆不同的一般化平衡族群之交配系統 ………… 98 9.4 一般化平衡族群的交配系統之性質………………………………… 100 9.4.1 雌雄交配基因型聯合頻率矩陣 之相關係數……………… 100 9.4.2 之子代群體配子結合之相關係數………………………… 102 9.4.3 之親代和子代基因型聯合頻率矩陣及其相關係數……… 104 9.4.3.1 之母子基因型聯合頻率矩陣及其相關係數……….. 104 9.4.3.2 之父子基因型聯合頻率矩陣及其相關係數………... 106 9.4.4 之二同胞基因型聯合頻率矩陣及其相關係數…………… 106 9.4.5 一般化平衡族群之性質彙整…………………………………… 109 第十章 結論與未來研究方向…………………………………….. 111 10.1 結論……………………………………………………………………. 111 10.2 未來研究方向…………………………………………………………. 115 參考文獻…………………………………………………………….. 117 / In population genetics it is known that there are many factors that may affect the genotypic and gene distributions of a population. The type of mating of a population is one of them. For examples, basically Hardy-Weinberg equilibrium law refers to a population undergoing random mating, and Wright's equilibrium law in inbreeding refers to a special type of nonrandom mating. This study performs a comprehensive investigation of all possible matings that can attain Hardy-Weinberg proportions or Wright proportions that had been or not had been discussed previously. The framework of mating systems attaining the Hardy-Weinberg proportions or Wright proportions will be established on the basis of pooling together factors such as the mating behavior, gene frequencies, genotypic frequencies and the Hardy-Weinberg proportions of the male and female subpopulations. The type and property of each mating system corresponding to each point of the established mating system framework are examined.
19

Measurement Of Sm Electro-weak Parameters In Reactor Antineutrino-electron Scattering In Texono Experiment

Deniz, Muhammed 01 May 2007 (has links) (PDF)
In this thesis a search for electron type neutrino-electron scattering cross-section and Weinberg Angle measurements were performed at KS Nuclear Power Station with 200 kg CsI(Tl) scintillating crystal detector located at a distance of 28 m from the 2.9 GW reactor core giving total flux of 6:52X10^12 cm^-2s^-1 in average at the experimental site. New analysis techniques and background suppression methods were developed. In the region of 3-8 MeV a measurement of SM cross section of (1:235+-0.577) XR_SM and Weinberg Angle of 0:264 +-0.075 which is quite consistent with the SM value of 0.23120(15)were obtained. These are the best results with wold wide level sensitivities at untested low energy region by using reactor anti-neutrinos.
20

The Rare Disease Assumption: The Good, The Bad, and The Ugly

Brems, Matthew William 01 June 2015 (has links)
No description available.

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