Spatial patterns of genetic relatedness among samples reflect the past movements of their ancestors. Our ability to untangle this history has the potential to improve dramatically given that we can now infer the ultimate description of genetic relatedness, the ancestral recombination graph (ARG). By extending spatial theory previously applied to trees, we generalize the common model of Brownian motion to full ARGs, thereby accounting for correlations in trees along a chromosome while efficiently computing likelihood-based estimates of dispersal rate and genetic ancestor locations, with associated uncertainties.
View Article and Find Full Text PDFTemporal variation in stress might signify changes in an animal's internal or external environment, while spatial variation in stress might signify variation in the quality of the habitats that individual animals experience. Habitat-induced variations in stress might be easiest to detect in highly territorial animals, and especially in species that do not take advantage of common strategies for modulating habitat-induced stress, such as migration (escape in space) or hibernation (escape in time). Spatial and temporal variation in response to potential stressors has received little study in wild animals, especially at scales appropriate for relating stress to specific habitat characteristics.
View Article and Find Full Text PDFGenetic factors impact alcohol use behaviors and these factors may become increasingly evident during emerging adulthood. Examination of the effects of individual variants as well as aggregate genetic variation can clarify mechanisms underlying risk. We conducted genome-wide association studies (GWAS) in an ethnically diverse sample of college students for three quantitative outcomes including typical monthly alcohol consumption, alcohol problems, and maximum number of drinks in 24 h.
View Article and Find Full Text PDFThe purpose of this study was to evaluate the delivery of alendronate, calcitonin, and osteoprotegerin (OPG) through human dentin by both diffusion and iontophoresis for the potential treatment of invasive cervical resorption. Radiolabeled alendronate, calcitonin, and OPG were added to the top of a split chamber device that contained 1-mm thick dentin disks devoid of a smear layer. Transdentinal movement of medicaments by either random diffusion or application of an iontophoretic current was measured by analysis of gamma emission of effluent fractions.
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