baysian

Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells...

The pygmy angelfishes (genus Centropyge, family Pomacanthidae) are brightly colored species that occupy reef habitats in every tropical ocean. Some species are rarely observed because they occur below conventional scuba depths. Their striking coloration can command thousands of U.S. dollars in the aquarium trade, and closely related species are often distinguished only by coloration. These factors have impeded phylogenetic resolution, and every phylogeographic survey to date has reported discordance between coloration, taxonomy, and genetic partitions...

Embryonic stem cell (ESC), iPCs, and adult stem cells (ASCs) all are among the most promising potential treatments for heart failure, spinal cord injury, neurodegenerative diseases, and diabetes. However, considerable uncertainty in the production of ESC-derived terminally differentiated cell types has limited the efficiency of their development. To address this uncertainty, we and other investigators have begun to employ a comprehensive statistical model of ESC differentiation for determining the role of intracellular pathways (e...

There is an urgent need to identify new treatments for the rapidly growing population of people with Alzheimer's disease (AD). Innovations in clinical trial designs many help to reduce development time, provide more definitive answers regarding drug efficacy, and facilitate prioritizing compounds to be advanced to Phase III clinical trials. Standard designs compare drug and placebo changes from baseline on a rating scale. Baysian adaptive clinical trials allow the use of data collected in the trial to modify doses, sample size, trial duration, and entry criteria in an ongoing way as the data are collected...

Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World. Its wide host range, high mobility and fecundity, and the ability to adapt and develop resistance against all common groups of insecticides used for its management have exacerbated its pest status. An understanding of the population genetic structure in H. armigera under Indian agricultural conditions will help ascertain gene flow patterns across different agricultural zones. This study inferred the population genetic structure of Indian H...

BACKGROUND: The goal of this study is to extend the applications of parametric survival models so that they include cases in which accelerated failure time (AFT) assumption is not satisfied, and examine parametric and semiparametric models under different proportional hazards (PH) and AFT assumptions. METHODS: The data for 12,531 women diagnosed with breast cancer in British Columbia, Canada, during 1990-1999 were divided into eight groups according to patients' ages and stage of disease, and each group was assumed to have different AFT and PH assumptions...

PURPOSE: To compare the intervention rates associated with labor in low-risk women who began their labor in the "home-like birth centre" (HLBC) and the traditional labor ward (TLW). METHODS: This retrospective study used data that were collected from January 2005 to June 2008, from women admitted to the HLBC (n = 316) and compared to a group of randomly selected low-risk women admitted to the TLW (n = 890) using the Baysian information criterion to select the best predictive model...

OBJECTIVES: To compare intervention rates associated with labor in low-risk women who began their labor in the "home-like birth centre" and the traditional delivery room. PATIENTS AND METHODS: This retrospective study used data that were collected from January 2005 through June 2008, from women admitted to the "home-like birth centre" (n=316) and compared to a group of randomly selected low-risk women admitted to the traditional labor ward (n=890) using the Baysian Information Criterion to select the best predictive model...

Different methods being used in the rare diseases clinical trials are examined. There is shown the purposefulness of using fuzzy approaches for such studies. Some advantages of Fuzzy logic methods in comparison with Baysian approach are substantiated.

Coherent optical signal processing methods for screening Pap smears were evaluated and are presented in a three-part sequence. In Part 1, 2-D Fourier spectra of normal and abnormal cells generated from many high resolution cell photographs are presented. Each cell spectrum was measured with a coherent optical data processing system containing a special geometry detector and automated data collection capability. Several parameters, determined from weighted measures of the cell transform intensity variations, were tested as feature discriminators to separate normal from abnormal cells...

Karenia brevis is the Florida red tide dinoflagellate responsible for detrimental effects on human and environmental health through the production of brevetoxins. Brevetoxins are thought to be synthesized by a polyketide synthase (PKS) complex, but the gene cluster for this PKS has yet to be identified. Here, eight PKS transcripts were identified in K. brevis by high throughput cDNA library screening. Full length sequences were obtained through 3' and 5' RACE, which demonstrated the presence of polyadenylation, 3'-UTRs, and an identical dinoflagellate-specific spliced leader sequence at the 5' end of PKS transcripts...

This paper addresses the problem of creating probabilistic brain atlases from manually labeled training data. We propose a general mesh-based atlas representation, and compare different atlas models by evaluating their posterior probabilities and the posterior probabilities of their parameters. Using such a Baysian framework, we show that the widely used "average" brain atlases constitute relatively poor priors, partly because they tend to overfit the training data, and partly because they do not allow to align corresponding anatomical features across datasets...

A new species of microsporidian, Trichonosema algonquinensis, is described from a freshwater bryozoan, Pectinatella magnifica from Ontario, Canada. The parasite develops in epithelial cells and appears as white, spherical masses throughout the tissues. Trichonosema algonquinensis is diplokaryotic, diploblastic and undergoes development in direct contact with the cytoplasm of the host cell. Mature spores are ovoid, tapered at one end, and measure 8.5 +/- 0.3 x 4.4 +/- 0.1 microm. The polar filament is wound in 20 to 23 helical coils...

INTRODUCTION: Multiple surgical approaches for the correction of stress urinary incontinence (SUI) have been described. In an attempt to determine which procedure may be superior, we performed a meta-analysis comparing the needle suspensions (i.e. Gittes, Stamey), Raz, Burch/MMK colposuspension, and urethral sling. METHODS: The most complete 87 of 310 articles relating to the surgical therapy for SUI published between 1982 and 1995 were selected by Medline search for review. These articles incorporated patients operated on from 1965 to 1995...

Women experience more adverse reactions to treatment with therapeutic drugs than men. Theories proposed to explain this include overdosing, different pharmacokinetics and pharmacodynamics, women are more likely to report adverse events than men, or women take more medications than men. Food and Drug Administration (FDA) Office of Women's Health (OWH) funds research to promote including women in clinical trials and understanding the biology of sex-related differences in the safety of FDA-regulated products. Including women in clinical trials advances the understanding of drug efficacy and safety in women by providing information on drug dosing, pharmacokinetics, and pharmacodynamics...

The field of survival analysis emerged in the 20th century and experienced tremendous growth during the latter half of the century. The developments in this field that have had the most profound impact on clinical trials are the Kaplan-Meier (1958, Journal of the American Statistical Association 53, 457-481) method for estimating the survival function, the log-rank statistic (Mantel, 1966, Cancer Chemotherapy Report 50, 163-170) for comparing two survival distributions, and the Cox (1972, Journal of the Royal Statistical Society, Series B 34, 187-220) proportional hazards model for quantifying the effects of covariates on the survival time...

adopt a traditional review of the mutagenicity data on TCE and its metabolites but instead raise several issues regarding the interpretation of mutagenicity and genetic toxicity tests in shedding light on whether these processes are key events in tumor initiation. As discussed in the U.S. EPA proposed cancer guidelines, a salient question is whether TCE or its metabolites interacts directly with and mutates DNA to bring about changes in gene expression or whether DNA mutation is achieved through some other process...

No abstract text is available yet for this article.

We derive an efficient algorithm for topographic mapping of proximity data (TMP), which can be seen as an extension of Kohonen's self-organizing map to arbitrary distance measures. The TMP cost function is derived in a Baysian framework of folded Markov chains for the description of autoencoders. It incorporates the data by a dissimilarity matrix D and the topographic neighborhood by a matrix H of transition probabilities. From the principle of maximum entropy, a nonfactorizing Gibbs distribution is obtained, which is approximated in a mean-field fashion...

The problem of competing risks analysis arises often in public health, demography, actuarial science, industrial reliability applications, and experiments in medical therapeutics. In the classical competing risks scenario one models the risks with a vector (T = (T1, ..., Tk) of non-negative random variables that represents the potential times to death of k risks. One cannot see T directly but sees instead Y = min (T1, ..., Tk) and the actual cause of death. The major difficulty with this analysis is the requirement for the expert to specify the single cause of death that, in fact, may not be the actual cause...