156 research outputs found
Bayesian Model Comparison in Genetic Association Analysis: Linear Mixed Modeling and SNP Set Testing
We consider the problems of hypothesis testing and model comparison under a
flexible Bayesian linear regression model whose formulation is closely
connected with the linear mixed effect model and the parametric models for SNP
set analysis in genetic association studies. We derive a class of analytic
approximate Bayes factors and illustrate their connections with a variety of
frequentist test statistics, including the Wald statistic and the variance
component score statistic. Taking advantage of Bayesian model averaging and
hierarchical modeling, we demonstrate some distinct advantages and
flexibilities in the approaches utilizing the derived Bayes factors in the
context of genetic association studies. We demonstrate our proposed methods
using real or simulated numerical examples in applications of single SNP
association testing, multi-locus fine-mapping and SNP set association testing
A statistical framework for joint eQTL analysis in multiple tissues
Mapping expression Quantitative Trait Loci (eQTLs) represents a powerful and
widely-adopted approach to identifying putative regulatory variants and linking
them to specific genes. Up to now eQTL studies have been conducted in a
relatively narrow range of tissues or cell types. However, understanding the
biology of organismal phenotypes will involve understanding regulation in
multiple tissues, and ongoing studies are collecting eQTL data in dozens of
cell types. Here we present a statistical framework for powerfully detecting
eQTLs in multiple tissues or cell types (or, more generally, multiple
subgroups). The framework explicitly models the potential for each eQTL to be
active in some tissues and inactive in others. By modeling the sharing of
active eQTLs among tissues this framework increases power to detect eQTLs that
are present in more than one tissue compared with "tissue-by-tissue" analyses
that examine each tissue separately. Conversely, by modeling the inactivity of
eQTLs in some tissues, the framework allows the proportion of eQTLs shared
across different tissues to be formally estimated as parameters of a model,
addressing the difficulties of accounting for incomplete power when comparing
overlaps of eQTLs identified by tissue-by-tissue analyses. Applying our
framework to re-analyze data from transformed B cells, T cells and fibroblasts
we find that it substantially increases power compared with tissue-by-tissue
analysis, identifying 63% more genes with eQTLs (at FDR=0.05). Further the
results suggest that, in contrast to previous analyses of the same data, the
majority of eQTLs detectable in these data are shared among all three tissues.Comment: Summitted to PLoS Genetic
Non-parametric Bayesian mixture model to study adverse events of COVID-19 vaccines
The vaccine adverse event reporting system (VAERS) is a vital resource for
post-licensure vaccine safety monitoring and has played a key role in assessing
the safety of COVID-19 vaccines. However it is difficult to properly identify
rare adverse events (AEs) associated with vaccines due to small or zero counts.
We propose a Bayesian model with a Dirichlet Process Mixture prior to improve
accuracy of the AE estimates with small counts by allowing data-guided
information sharing between AE estimates. We also propose a negative control
procedure embedded in our Bayesian model to mitigate the reporting bias due to
the heightened awareness of COVID-19 vaccines, and use it to identify
associated AEs as well as associated AE groups defined by the organ system in
the Medical Dictionary for Regulatory Activities (MedDRA) ontology. The
proposed model is evaluated using simulation studies, in which it outperforms
baseline models without information sharing and is applied to study the safety
of COVID-19 vaccines using VAERS data
ChatHome: Development and Evaluation of a Domain-Specific Language Model for Home Renovation
This paper presents the development and evaluation of ChatHome, a
domain-specific language model (DSLM) designed for the intricate field of home
renovation. Considering the proven competencies of large language models (LLMs)
like GPT-4 and the escalating fascination with home renovation, this study
endeavors to reconcile these aspects by generating a dedicated model that can
yield high-fidelity, precise outputs relevant to the home renovation arena.
ChatHome's novelty rests on its methodology, fusing domain-adaptive pretraining
and instruction-tuning over an extensive dataset. This dataset includes
professional articles, standard documents, and web content pertinent to home
renovation. This dual-pronged strategy is designed to ensure that our model can
assimilate comprehensive domain knowledge and effectively address user
inquiries. Via thorough experimentation on diverse datasets, both universal and
domain-specific, including the freshly introduced "EvalHome" domain dataset, we
substantiate that ChatHome not only amplifies domain-specific functionalities
but also preserves its versatility.Comment: ChatHome,DSLM for home renovatio
On weakly bounded well-filtered spaces
In [16], using Rudin sets, Miao, Li and Zhao introduced a new concept of weakly well-filtered spaces—-bounded well-filtered spaces. Now, also using Rudin sets, we introduce another type of spaces—weakly bounded well-filtered spaces, which are strictly stronger than -bounded well-filtered spaces. Some basic properties of -bounded well-filtered spaces and weakly bounded well-filtered spaces are investigated and the relationships among some kinds of weakly sober spaces and weakly well-filtered spaces are posed. It is proved that the category is not reflective in the category
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