Search results for "Bayes"
showing 10 items of 847 documents
Reproducing kernel hilbert spaces regression methods for genomic assisted prediction of quantitative traits.
2008
Abstract Reproducing kernel Hilbert spaces regression procedures for prediction of total genetic value for quantitative traits, which make use of phenotypic and genomic data simultaneously, are discussed from a theoretical perspective. It is argued that a nonparametric treatment may be needed for capturing the multiple and complex interactions potentially arising in whole-genome models, i.e., those based on thousands of single-nucleotide polymorphism (SNP) markers. After a review of reproducing kernel Hilbert spaces regression, it is shown that the statistical specification admits a standard mixed-effects linear model representation, with smoothing parameters treated as variance components.…
Stones, Bones, and Hillfort: Radiocarbon Dating of Ķivutkalns Bronze-Working Center
2013
The Bronze Age site of ķivutkalns with its massive amount of archaeological artifacts and human remains is considered the largest bronze-working center in Latvia. The site is a unique combination of cemetery and hillfort believed to be built on top of each other. This work presents new radiocarbon dates on human and animal bone collagen that somewhat challenge this interpretation. Based on analyses using a Bayesian modeling framework, the present data suggest overlapping calendar year distributions for the contexts within the 1st millennium BC. The carbon and nitrogen isotopic ratios indicate mainly terrestrial dietary habits of studied individuals and nuclear family remains buried in one o…
Radiocarbono y estadística Bayesiana: aportaciones a la cronología de la Edad del Bronce en el extremo oriental del sudeste de la península Ibérica
2014
La investigación arqueológica desarrollada en las últimas décadas ha permitido evaluar que en los valles de los ríos Segura y Vinalopó se dirimió el contacto entre dos sociedades de la Edad del Bronce de la península Ibérica: el grupo Argárico y el grupo del Prebético Meridional Valenciano. Las excavaciones realizadas en tres yacimientos de este ámbito - Terlinques, Cabezo Pardo y Cabezo Redondo- y las dotaciones de radiocarbono obtenidas permiten por primera vez evaluar la diacronía del proceso histórico que envolvió el desarrollo de ambos grupos arqueológicos a lo largo del II milenio cal BC, así como determinar diversos momentos socialmente significativos en su devenir histórico. Para el…
Barrier effects on the spatial distribution of Xylella fastidiosa in Alicante, Spain
2021
AbstractSpatial models often assume isotropy and stationarity, implying that spatial dependence is direction invariant and uniform throughout the study area. However, these assumptions are violated when dispersal barriers are present in the form of geographical features or disease control interventions. Despite this, the issue of non-stationarity has been little explored in the context of plant health. The objective of this study was to evaluate the influence of different barriers in the distribution of the quarantine plant pathogenic bacterium Xylella fastidiosa in the demarcated area in Alicante, Spain. Occurrence data from the official surveys in 2018 were analyzed with four spatial Baye…
Socio-economic deprivation and COVID-19 infection: a Bayesian spatial modelling approach
2022
Il presente articolo ha l’obiettivo di analizzare l’effetto della deprivazione socio-economica sull’incidenza da COVID-19 a livello sub-comunale. Grazie alla disponibilit`a di informazioni sui tassi di incidenza mensili da COVID-19 a livello di sezione di censimento per i due comuni di Palermo e Catania (Italia), viene pro- posto l’utilizzo di un modello spaziale Bayesiano con distribuzione binomiale zero- inflated. I risultati mostrano un’associazione tra livelli di deprivazione e incidenza da COVID-19 nei due comuni, controllando per la struttura spaziale delle unit`a areali considerate. Alla luce dei risultati, si rendono necessarie azioni di politica sanitaria focalizzando gli intervent…
Statistical methods for spatial cluster detection in childhood cancer incidence : A simulation study
2021
BACKGROUND AND OBJECTIVE: The potential existence of spatial clusters in childhood cancer incidence is a debated topic. Identification of such clusters may help to better understand etiology and develop preventive strategies. We evaluated widely used statistical approaches to cluster detection in this context.; METHODS: Incidence of newly diagnosed childhood cancer (140/1,000,000 children under 15 years) and nephroblastoma (7/1,000,000) was simulated. Clusters of defined size (1-50) were randomly assembled on the district level in Germany. Each cluster was simulated with different relative risk levels (1-100). For each combination 2000 iterations were done. Simulated data was then analyzed …
Whole-Genome Re-Sequencing Data to Infer Historical Demography and Speciation Processes in Land Snails: the Study of Two Candidula Sister Species
2021
Despite the global biodiversity of terrestrial gastropods and their ecological and economic importance, the genomic basis of ecological adaptation and speciation in land snail taxa is still largely unknown. Here, we combined whole-genome re-sequencing with population genomics to evaluate the historical demography and the speciation process of two closely related species of land snails from western Europe, Candidula unifasciata and C. rugosiuscula. Historical demographic analysis indicated fluctuations in the size of ancestral populations, probably driven by Pleistocene climatic fluctuations. Although the current population distributions of both species do not overlap, our approximate Bayesi…
Temporal speciation pattern in the western Mediterranean genus Tudorella P. Fischer, 1885 (Gastropoda, Pomatiidae) supports the Tyrrhenian vicariance…
2009
The land snail genus Tudorella shows a peculiar disjunct distribution around the western Mediterranean coasts. Despite high phenotypic plasticity, only two species with a disputed number of subspecific taxa are currently recognised. We delimited the species with mitochondrial (COI & 16S) and nuclear (ITS-1) markers based on the unified species concept and suggested that there are eight species in the genus, two of them currently undescribed. Applying Bayesian phylogenetic model selection, we tested four different biogeographic hypotheses that could be causal for the current distribution pattern of extant Tudorella species. A scenario involving vicariance events resulting from the repeated s…
Molecular evolution and complete genome sequences in forensic analysis: Neisseria gonorrhoeae in a transmission case
2019
Molecular epidemiology and phylogenetic analyses are frequently used in the investigation of viral transmission cases in forensic contexts. Here, we present the methods and results of the analysis of a bacterial transmission in an alleged child abuse case using complete genome sequences obtained by high-throughput sequencing (HTS) methods.
A computer program suitable for analysis of choice of categories in biomedical data recognition problems.
1980
The optimum choice of categories in problems of medical data recognition is governed by the choice of categories, the selection of appropriate features, and by the choice of a loss function. Under these circumstances it is often difficult to find out the suitable classification scheme. The computer program described here serves for the design of the optimum recognition procedure. The Bayes rule is used as decision rule. A criterion for the comparison of different choice of categories is given. The program can be performed after estimation of the underlying prior probabilities and the conditional densities obtained from a training set, and before testing the decision rule with real data.