Bayesian multi-QTL mapping for growth curve parameters

Background Identification of QTL affecting a phenotype which is measured multiple times on the same experimental unit is not a trivial task because the repeated measures are not independent and in most cases show a trend in time. A complicating factor is that in most cases the mean increases non-linear with time as well as the variance. A two- step approach was used to analyze a simulated data set containing 1000 individuals with 5 measurements each. First the measurements were summarized in latent variables and subsequently a genome wide analysis was performed of these latent variables to identify segregating QTL using a Bayesian algorithm. Results For each individual a logistic growth curve was fitted and three latent variables: asymptote (ASYM), inflection point (XMID) and scaling factor (SCAL) were estimated per individual. Applying an 'animal' model showed heritabilities of approximately 48% for ASYM and SCAL while the heritability for XMID was approximately 24%. The genome wide scan revealed four QTLs affecting ASYM, one QTL affecting XMID and four QTLs affecting SCAL. The size of the QTL differed. QTL with a larger effect could be more precisely located compared to QTL with small effect. The locations of the QTLs for separate parameters were very close in some cases and probably caused the genetic correlation observed between ASYM and XMID and SCAL respectively. None of the QTL appeared on chromosome five. Conclusions Repeated observations on individuals were affected by at least nine QTLs. For most QTL a precise location could be determined. The QTL for the inflection point (XMID) was difficult to pinpoint and might actually exist of two closely linked QTL on chromosome one

Bayesian Analysis of Heterogeneous Residual Variance in Canine Behaviour

Non-additive effects like for instance genotype-environment interactions and genetically structured heterogeneity of residual variance are notoriously dependent on scale: many statistical non-additive phenomena disappear after a careful choice of transformation of the phenotypic values. Particularly for behavioural measures, scale is a delicate matter. We present a novel Bayesian approach that assesses heterogeneity in environmental variance as a function of genetic effects, where the scale is defined by a psychometric model based on item-response theory. This makes analysis results independent of what items are in a particular test version. We apply the method to fearful behaviour in dogs and compare results with the more usual sum score approac

Довгостроковий часовий прогноз розвитку карсту на Передкарпатті

Здійснено довгостроковий часовий прогноз активізації сульфатного карсту в Передкарпатті. В якості факторів активізації розглянуті сонячна і сейсмічна активність, метеорологічні та гідрогеологічні дані. Основою часового прогнозу, здійсненого до 2020 року, служить теорія про ритмічність природних явищ, їх взаємозв’язок і взаємообумовленість.Осуществлен временной прогноз активизации сульфатного карста в Предкарпатье. В качестве факторов активизации рассмотрены солнечная и сейсмическая активность, метеорологические и гидрогеологические данные. Основой временного прогноза, осуществленного до 2020 года является теория о ритмичности природных явлений, их взаимосвязи и взаимообусловленности.The long-term time forecast of sulfate cockpit activation throughout the Piedmont Carpathians has been accomplished. The leading factors-activators include: solar and seismic activity as well as meteorological and hydro-geological data. The backbone of this prognosis for the period up to 2020 is represented by the theory of rhythm among natural phenomena, their interconnection and stipulation

Украина — член международной комиссии по блоьшим плотинам

Within Herd Test Prevalence Affects Genetic Variation in Antibody Response to Mycobacterium avium Subspecies paratuberculosis in Milk of Dutch Holstein-Friesians - K.J.E. van Hulzen, M. Nielen, A.P. Koets, G. de Jong, J.A.M. van Arendonk and H.C.M. Heuven. Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands. Worldwide, classical control strategies based on hygiene and culling of infected animals have not been able to eradicate Johne’s disease. Therefore, breeding for disease resistance may be a useful tool to contribute to control the disease. In this study, genetic parameters were estimated for the presence of a Mycobacterium avium subspecies paratuberculosis specific antibody response in milk of Dutch Holstein-Friesians using subsets of data based on within herd test prevalence levels. The estimated heritability ranged from 3.1% for the complete dataset to 9.7% for herds with a minimum test prevalence of 10%. Cross-validation analysis showed that breeding values were predicted most accurately using data obtained from herds with at least 2 positive tested animals, hence a heritability of 4.1% (± 0.4)