62 research outputs found
Analysis of genome-wide structure, diversity and fine mapping of Mendelian traits in traditional and village chickens
Extensive phenotypic variation is a common feature among village chickens found throughout much of the developing world, and in traditional chicken breeds that have been artificially selected for traits such as plumage variety. We present here an assessment of traditional and village chicken populations, for fine mapping of Mendelian traits using genome-wide single-nucleotide polymorphism (SNP) genotyping while providing information on their genetic structure and diversity. Bayesian clustering analysis reveals two main genetic backgrounds in traditional breeds, Kenyan, Ethiopian and Chilean village chickens. Analysis of linkage disequilibrium (LD) reveals useful LD (r(2)â©Ÿ0.3) in both traditional and village chickens at pairwise marker distances of âŒ10âKb; while haplotype block analysis indicates a median block size of 11â12âKb. Association mapping yielded refined mapping intervals for duplex comb (Gga 2:38.55â38.89âMb) and rose comb (Gga 7:18.41â22.09âMb) phenotypes in traditional breeds. Combined mapping information from traditional breeds and Chilean village chicken allows the oocyan phenotype to be fine mapped to two small regions (Gga 1:67.25â67.28âMb, Gga 1:67.28â67.32âMb) totalling âŒ75âKb. Mapping the unmapped earlobe pigmentation phenotype supports previous findings that the trait is sex-linked and polygenic. A critical assessment of the number of SNPs required to map simple traits indicate that between 90 and 110K SNPs are required for full genome-wide analysis of haplotype block structure/ancestry, and for association mapping in both traditional and village chickens. Our results demonstrate the importance and uniqueness of phenotypic diversity and genetic structure of traditional chicken breeds for fine-scale mapping of Mendelian traits in the species, with village chicken populations providing further opportunities to enhance mapping resolutions
The spine in Pagetâs disease
Pagetâs disease (PD) is a chronic metabolically active bone disease, characterized by a disturbance in bone modelling and remodelling due to an increase in osteoblastic and osteoclastic activity. The vertebra is the second most commonly affected site. This article reviews the various spinal pathomechanisms and osseous dynamics involved in producing the varied imaging appearances and their clinical relevance. Advanced imaging of osseous, articular and bone marrow manifestations of PD in all the vertebral components are presented. Pagetic changes often result in clinical symptoms including back pain, spinal stenosis and neural dysfunction. Various pathological complications due to PD involvement result in these clinical symptoms. Recognition of the imaging manifestations of spinal PD and the potential complications that cause the clinical symptoms enables accurate assessment of patients prior to appropriate management
Informed Conditioning on Clinical Covariates Increases Power in Case-Control Association Studies
Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from lowâBMI cases are larger than those estimated from highâBMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment) or phenotype and clinical covariates (case-control-covariate ascertainment). While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-valueâ=â1Ă10â9). The improvement varied across diseases with a 16% median increase in Ï2 test statistics and a commensurate increase in power. This suggests that applying our method to existing and future association studies of these diseases may identify novel disease loci
Genetic variants linked to education predict longevity
Educational attainment is associated with many health outcomes, including longevity. It is also known to be substantially heritable. Here, we used data from three large genetic epidemiology cohort studies (Generation Scotland, n = âŒ17,000; UK Biobank, n = âŒ115,000; and the Estonian Biobank, n = âŒ6,000) to test whether education-linked genetic variants can predict lifespan length. We did so by using cohort membersâ polygenic profile score for education to predict their parentsâ longevity. Across the three cohorts, meta-analysis showed that a 1 SD higher polygenic education score was associated with âŒ2.7% lower mortality risk for both mothers (total ndeaths = 79,702) and âŒ2.4% lower risk for fathers (total ndeaths = 97,630). On average, the parents of offspring in the upper third of the polygenic score distribution lived 0.55 y longer compared with those of offspring in the lower third. Overall, these results indicate that the genetic contributions to educational attainment are useful in the prediction of human longevity.</p
Advanced Method for the Treatment of Organic Aqueous Wastes: Wet Peroxide Oxidation â WPOÂź, Laboratory Studies and Industrial Development
International audienceA wide range of organic effluents produced by the chemical industry cannot be efficiently treated by biological methods, often because of their toxicity. A new liquid phase oxidation process, which is derived from the Fentonâs reaction, using hydrogen peroxide at a high temperature (120°C) and iron salts as catalyst, has been developed to help solve this problem. This process, named âWet Peroxide Oxidationâ (WPOÂź), is well suited for effluents containing between 0.5 and 10 g/1 of carbon (TOC). A limited capital cost associated with a reasonable running cost are its main characteristics, as well as flexibility. It can be run alone before releasing-off the treated wastes or associated with other methods as either a pre-treatment or a post-treatment step.Several pure test compounds, wastes and by-products from various industries such as paper, petroleum, chemical and pharmaceutical, have been treated by the WPOÂź process. In most cases, an almost total oxidation was obtained. However, the Fentonâs reaction efficiency is limited by the accumulation of volatile fatty acids such as oxalic, malonic, succinic and acetic acids (hereafter OMSA). In order to improve the efficiency of the original process, various transition metal ions have been tested as catalysts. The experimental results indicated that the system using simultaneously homogeneous Fe, Cu and Mn is a promising one. This new catalytic system allows efficient elimination at a temperature not greater than 100 °C to avoid pressurization of the treatment reactor.A pilot plant unit has been developed, which was mainly used for polluted water tables treatment during industrial sites reclamation and industrial wastewater treatment. The efficiency of the method was established on a large scale basis. At the same time, economical data were assessed
Controlling the proliferation of Zygosaccharomyces bailii in ephedrine anti-phlegm cough mixture
Factors affecting the development of precipitating antibodies in workers exposed to contaminated humidifiers
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