Fast simulation of identity-by-descent segments.

The worst-case runtime complexity to simulate haplotype segments identical by descent (IBD) is quadratic in sample size. We propose two main techniques to reduce the compute time, both of which are motivated by coalescent and recombination processes. We provide mathematical results that explain why our algorithm should outperform a naive implementation with high probability.

Adjusting for principal components can induce collider bias in genome-wide association studies.

Principal component analysis (PCA) is widely used to control for population structure in genome-wide association studies (GWAS). Top principal components (PCs) typically reflect population structure, but challenges arise in deciding how many PCs are needed and ensuring that PCs do not capture other artifacts such as regions with atypical linkage disequilibrium (LD). In response to the latter, many groups suggest performing LD pruning or excluding known high LD regions prior to PCA.

Prevalence, predictors, and patterns of patient reported non-motor outcomes six months after stroke: a prospective cohort study.

Background: Adverse non-motor outcomes have a major impact on patients and caregivers after stroke, but knowledge of their prevalence, predictors and patterns across multiple health domains remains limited; we therefore aimed to obtain these data in a large observational prospective cohort study.

Methods: We included data from the Stroke Investigation Group in North and Central London (SIGNAL) registry based at the University College London Hospitals (UCLH) Comprehensive Stroke Service which serves a multi-ethnic population of ∼1.6 million people.

Case Report: Effects of Environmental Smoke Exposure on Respiratory Conditions-A Report of an Aboriginal Man Fire Hunting for Mud Turtles in the Top End, Northern Territory of Australia.

Environmental smoke has been shown to have significant associations with both causation and exacerbation of respiratory conditions. Aboriginal Australians in the Northern Territory (NT) of Australia are disproportionately affected by respiratory illness in comparison with non-Aboriginal Australians. Traditionally, Aboriginal communities have utilized fire for multiple purposes, such as land management practices, cultural ceremonies, hunting, and cooking.