26 research outputs found
Social Network Analysis on Food Web and Dispute Data
Several social science disciplines, especially anthropology and sociology, have long engaged in social network analyses. Social Network Analysis (SNA) uses network theory to analyse social networks – a network that often involves individual social actors (people) and relations between them. Social network analysis aims at understanding the network structure by description, visualization, and statistical modeling. In this research, the illustration of the use of SNA is done on two different datasets: food web data and militarized interstate dispute data
Latent Causal Socioeconomic Health Index
This research develops a model-based LAtent Causal Socioeconomic Health
(LACSH) index at the national level. We build upon the latent health factor
index (LHFI) approach that has been used to assess the unobservable
ecological/ecosystem health. This framework integratively models the
relationship between metrics, the latent health, and the covariates that drive
the notion of health. In this paper, the LHFI structure is integrated with
spatial modeling and statistical causal modeling, so as to evaluate the impact
of a continuous policy variable (mandatory maternity leave days and
government's expenditure on healthcare, respectively) on a nation's
socioeconomic health, while formally accounting for spatial dependency among
the nations. A novel visualization technique for evaluating covariate balance
is also introduced for the case of a continuous policy (treatment) variable. We
apply our LACSH model to countries around the world using data on various
metrics and potential covariates pertaining to different aspects of societal
health. The approach is structured in a Bayesian hierarchical framework and
results are obtained by Markov chain Monte Carlo techniques.Comment: 31 pages. arXiv admin note: substantial text overlap with
arXiv:1911.0051
Latent Socio-Economic Health and Causal Modelling
This research attempts to develop model-based socio-economic health measures using statistical causal inference and modelling. There is a growing consensus for an alternative measure to Gross Domestic Product (GDP) for a country’s socio-economic health. Many conventional ways of constructing the health indices involve combining different observable metrics to form an index. However, the ‘health’ of a society is inherently latent, with the metrics being observable indicators of health. Much effort has been attempted to provide this alternative measure but none to our knowledge so far that uses a model-based approach to reflect the latent health. To take this into account, we adopt the latent health factor index (LHFI) approach that has been used in assessing ecological health. This framework integratively models the relationship between metrics, the unobservable latent health, and the covariates that drive the notion of health. Moreover, we are extending the LHFI approach by integrating it with statistical causal modelling to investigate the causes and effects embedded in the factors influencing health and the metrics. We implement our model using data pertaining to different aspects of societal health and potential explanatory variables. The approach is structured in a Bayesian hierarchical framework and the results obtained by applying Markov Chain Monte Carlo (MCMC) techniques. The resulting health measures aim to provide a holistic quantification of the overall ‘health’ of a society.IBISWorld Industrial Gran
Genome-wide meta-analysis of 241,258 adults accounting for smoking behaviour identifies novel loci for obesity traits
Few genome-wide association studies (GWAS) account for environmental exposures, like smoking, potentially impacting the overall trait variance when investigating the genetic contribution to obesity-related traits. Here, we use GWAS data from 51,080 current smokers and 190,178 nonsmokers (87% European descent) to identify loci influencing BMI and central adiposity, measured as waist circumference and waist-to-hip ratio both adjusted for BMI. We identify 23 novel genetic loci, and 9 loci with convincing evidence of gene-smoking interaction (GxSMK) on obesity-related traits. We show consistent direction of effect for all identified loci and significance for 18 novel and for 5 interaction loci in an independent study sample. These loci highlight novel biological functions, including response to oxidative stress, addictive behaviour, and regulatory functions emphasizing the importance of accounting for environment in genetic analyses. Our results suggest that tobacco smoking may alter the genetic susceptibility to overall adiposity and body fat distribution.Peer reviewe
Juden und Deutsche : ein Resumé
von Anton Ku
Recommended from our members
The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study.
Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape