Orthogonal Polynomial Representation of Imaginary-Time Green's Functions

We study the expansion of single-particle and two-particle imaginary-time Matsubara Green's functions of quantum impurity models in the basis of Legendre orthogonal polynomials. We discuss various applications within the dynamical mean-field theory (DMFT) framework. The method provides a more compact representation of the Green's functions than standard Matsubara frequencies and therefore significantly reduces the memory-storage size of these quantities. Moreover, it can be used as an efficient noise filter for various physical quantities within the continuous-time quantum Monte Carlo impurity solvers recently developed for DMFT and its extensions. In particular, we show how to use it for the computation of energies in the context of realistic DMFT calculations in combination with the local density approximation to the density functional theory (LDA+DMFT) and for the calculation of lattice susceptibilities from the local irreducible vertex function.Comment: 14 pages, 11 figure

Meta‐analysis of gene‐environment interaction exploiting gene‐environment independence across multiple case‐control studies

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138916/1/sim7398_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138916/2/sim7398.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138916/3/sim7398-sup-001-sup.pd

School-based intervention study examining approaches for well-being and mental health literacy of pupils in Year 9 in England: study protocol for a multischool, parallel group cluster randomised controlled trial (AWARE)

Introduction The prevalence of emotional difficulties in young people is increasing. This upward trend is largely accounted for by escalating symptoms of anxiety and depression. As part of a public health response, there is increasing emphasis on universal prevention programmes delivered in school settings. This protocol describes a three-arm, parallel group cluster randomised controlled trial, investigating the effectiveness and cost-effectiveness of two interventions, alongside a process and implementation evaluation, to improve mental health and well-being of Year 9 pupils in English secondary schools. Method A three-arm, parallel group cluster randomised controlled trial comparing two different interventions, the Youth Aware of Mental Health (YAM) or the Mental Health and High School Curriculum Guide (The Guide), to Usual Provision. Overall, 144 secondary schools in England will be recruited, involving 8600 Year 9 pupils. The primary outcome for YAM is depressive symptoms, and for The Guide it is intended help-seeking. These will be measured at baseline, 3–6 months and 9–12 months after the intervention commenced. Secondary outcomes measured concurrently include changes to: positive well-being, behavioural difficulties, support from school staff, stigma-related knowledge, attitudes and behaviours, and mental health first aid. An economic evaluation will assess the cost-effectiveness of the interventions, and a process and implementation evaluation (including a qualitative research component) will explore several aspects of implementation (fidelity, quality, dosage, reach, participant responsiveness, adaptations), social validity (acceptability, feasibility, utility), and their moderating effects on the outcomes of interest, and perceived impact. Ethics and dissemination This trial has been approved by the University College London Research Ethics Committee. Findings will be published in a report to the Department for Education, in peer-reviewed journals and at conferences

Whole Genome Sequencing in Psychiatric Disorders: the WGSPD Consortium

As technology advances, whole genome sequencing (WGS) is likely to supersede other genotyping technologies. The rate of this change depends on its relative cost and utility. Variants identified uniquely through WGS may reveal novel biological pathways underlying complex disorders and provide high-resolution insight into when, where, and in which cell type these pathways are affected. Alternatively, cheaper and less computationally intensive approaches may yield equivalent insights. Understanding the role of rare variants in the noncoding gene-regulating genome, through pilot WGS projects, will be critical to determine which of these two extremes best represents reality. With large cohorts, well-defined risk loci, and a compelling need to understand the underlying biology, psychiatric disorders have a role to play in this preliminary WGS assessment. The WGSPD consortium will integrate data for 18,000 individuals with psychiatric disorders, beginning with autism spectrum disorder, schizophrenia, bipolar disorder, and major depressive disorder, along with over 150,000 controls

LocusZoom: regional visualization of genome-wide association scan results

Summary: Genome-wide association studies (GWAS) have revealed hundreds of loci associated with common human genetic diseases and traits. We have developed a web-based plotting tool that provides fast visual display of GWAS results in a publication-ready format. LocusZoom visually displays regional information such as the strength and extent of the association signal relative to genomic position, local linkage disequilibrium (LD) and recombination patterns and the positions of genes in the region

Bayesian methods and optimal experimental design for gene mapping by radiation hybrids

Radiation hybrid mapping is a somatic cell technique for ordering human loci along a chromosome and estimating the physical distance between adjacent loci. The present paper considers a realistic model of fragment generation and retention. This model assumes that fragments are generated in the ancestral cell of a clone according to a Poisson breakage process along the chromosome. Once generated, fragments are independently retained in the clone with a common retention probability. Based on this and less restrictive models, statistical criteria such as minimum obligate breaks, maximum likelihood, and Bayesian posterior probabilities can be used to decide order. Distances can be estimated by either maximum likelihood or Bayesian posterior means. The model also permits rational design of radiation dose for optimal statistical precision. A brief examination of some real data illustrates our criteria and computational algorithms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65749/1/j.1469-1809.1992.tb01139.x.pd