scholarly journals Genomics of isolation in hybrids

2012 ◽  
Vol 367 (1587) ◽  
pp. 439-450 ◽  
Author(s):  
Zachariah Gompert ◽  
Thomas L. Parchman ◽  
C. Alex Buerkle
Keyword(s):  
Reproductive Isolation ◽  
Genetic Architecture ◽  
Large Scale ◽  
Empirical Studies ◽  
Hybrid Zones ◽  
Direct Measure ◽  
Fitness Effects ◽  
Outlier Loci ◽  
Admixed Population ◽  
Genome Level

Hybrid zones are common in nature and can offer critical insights into the dynamics and components of reproductive isolation. Hybrids between diverged lineages are particularly informative about the genetic architecture of reproductive isolation, because introgression in an admixed population is a direct measure of isolation. In this paper, we combine simulations and a new statistical model to determine the extent to which different genetic architectures of isolation leave different signatures on genome-level patterns of introgression. We found that reproductive isolation caused by one or several loci of large effect caused greater heterogeneity in patterns of introgression than architectures involving many loci with small fitness effects, particularly when isolating factors were closely linked. The same conditions that led to heterogeneous introgression often resulted in a reasonable correspondence between outlier loci and the genetic loci that contributed to isolation. However, demographic conditions affected both of these results, highlighting potential limitations to the study of the speciation genomics. Further progress in understanding the genomics of speciation will require large-scale empirical studies of introgression in hybrid zones and model-based analyses, as well as more comprehensive modelling of the expected levels of isolation with different demographies and genetic architectures of isolation.

Bullying, School Violence, and Climate in Evolving Contexts

2018 ◽  
Author(s):  
Ron Avi Astor ◽  
Rami Benbenisthty
Keyword(s):  
School Violence ◽  
School Safety ◽  
Media Coverage ◽  
Large Scale ◽  
Ecological Model ◽  
Empirical Studies ◽  
Practical Applications ◽  
Teacher Student ◽  
Area Of Interest ◽  
New Research

Since 2005, the bullying, school violence, and school safety literatures have expanded dramatically in content, disciplines, and empirical studies. However, with this massive expansion of research, there is also a surprising lack of theoretical and empirical direction to guide efforts on how to advance our basic science and practical applications of this growing scientific area of interest. Parallel to this surge in interest, cultural norms, media coverage, and policies to address school safety and bullying have evolved at a remarkably quick pace over the past 13 years. For example, behaviors and populations that just a decade ago were not included in the school violence, bullying, and school safety discourse are now accepted areas of inquiry. These include, for instance, cyberbullying, sexting, social media shaming, teacher–student and student–teacher bullying, sexual harassment and assault, homicide, and suicide. Populations in schools not previously explored, such as lesbian, gay, bisexual, transgender, and queer students and educators and military- and veteran-connected students, become the foci of new research, policies, and programs. As a result, all US states and most industrialized countries now have a complex quilt of new school safety and bullying legislation and policies. Large-scale research and intervention funding programs are often linked to these policies. This book suggests an empirically driven unifying model that brings together these previously distinct literatures. This book presents an ecological model of school violence, bullying, and safety in evolving contexts that integrates all we have learned in the 13 years, and suggests ways to move forward.

Hybrid Zones and the Genetic Architecture of a Barrier to Gene Flow Between Two Sunflower Species

Genetics ◽  
1999 ◽  
Vol 152 (2) ◽  
pp. 713-727 ◽  
Author(s):  
Loren H Rieseberg ◽  
Jeannette Whitton ◽  
Keith Gardner
Keyword(s):  
Genetic Study ◽  
Genetic Architecture ◽  
Chromosomal Rearrangements ◽  
Pollen Sterility ◽  
Model Organisms ◽  
Hybrid Zones ◽  
Reproductive Barriers ◽  
Natural Hybrid ◽  
Generation Times ◽  
Helianthus Petiolaris

Abstract Genetic analyses of reproductive barriers represent one of the few methods by which theories of speciation can be tested. However, genetic study is often restricted to model organisms that have short generation times and are easily propagated in the laboratory. Replicate hybrid zones with a diversity of recombinant genotypes of varying age offer increased resolution for genetic mapping experiments and expand the pool of organisms amenable to genetic study. Using 88 markers distributed across 17 chromosomes, we analyze the introgression of chromosomal segments of Helianthus petiolaris into H. annuus in three natural hybrid zones. Introgression was significantly reduced relative to neutral expectations for 26 chromosomal segments, suggesting that each segment contains one or more factors that contribute to isolation. Pollen sterility is significantly associated with 16 of these 26 segments, providing a straightforward explanation of why this subset of blocks is disadvantageous in hybrids. In addition, comparison of rates of introgression across colinear vs. rearranged chromosomes indicates that close to 50% of the barrier to introgression is due to chromosomal rearrangements. These results demonstrate the utility of hybrid zones for identifying factors contributing to isolation and verify the prediction of increased resolution relative to controlled crosses.

scholarly journals Supply chain resilience in a developing country context: a case study on the interconnectedness of threats, strategies and outcomes

2017 ◽  
Vol 22 (6) ◽  
pp. 486-505 ◽  
Author(s):  
Benjamin Tukamuhabwa ◽  
Mark Stevenson ◽  
Jerry Busby
Keyword(s):  
Supply Chain ◽  
Developing Country ◽  
Large Scale ◽  
Empirical Studies ◽  
Small Scale ◽  
Supply Network ◽  
Catastrophic Events ◽  
Content Type ◽  
Supply Chain Resilience

Purpose In few prior empirical studies on supply chain resilience (SCRES), the focus has been on the developed world. Yet, organisations in developing countries constitute a significant part of global supply chains and have also experienced the disastrous effects of supply chain failures. The purpose of this paper is therefore to empirically investigate SCRES in a developing country context and to show that this also provides theoretical insights into the nature of what is meant by resilience. Design/methodology/approach Using a case study approach, a supply network of 20 manufacturing firms in Uganda is analysed based on a total of 45 interviews. Findings The perceived threats to SCRES in this context are mainly small-scale, chronic disruptive events rather than discrete, large-scale catastrophic events typically emphasised in the literature. The data reveal how threats of disruption, resilience strategies and outcomes are inter-related in complex, coupled and non-linear ways. These interrelationships are explained by the political, cultural and territorial embeddedness of the supply network in a developing country. Further, this embeddedness contributes to the phenomenon of supply chain risk migration, whereby an attempt to mitigate one threat produces another threat and/or shifts the threat to another point in the supply network. Practical implications Managers should be aware, for example, of potential risk migration from one threat to another when crafting strategies to build SCRES. Equally, the potential for risk migration across the supply network means managers should look at the supply chain holistically because actors along the chain are so interconnected. Originality/value The paper goes beyond the extant literature by highlighting how SCRES is not only about responding to specific, isolated threats but about the continuous management of risk migration. It demonstrates that resilience requires both an understanding of the interconnectedness of threats, strategies and outcomes and an understanding of the embeddedness of the supply network. Finally, this study’s focus on the context of a developing country reveals that resilience should be equally concerned both with smaller in scale, chronic disruptions and with occasional, large-scale catastrophic events.

“I Will Never Know the Person Who I Could Have Become”: Perceived Changes in Self-Identity Among Adult Survivors of Clergy-Perpetrated Sexual Abuse

2016 ◽  
Vol 34 (6) ◽  
pp. 1139-1162 ◽  
Author(s):  
Scott D. Easton ◽  
Danielle M. Leone-Sheehan ◽  
Patrick J. O’Leary
Keyword(s):  
Sexual Abuse ◽  
Media Coverage ◽  
Large Scale ◽  
Clinical Sample ◽  
Empirical Studies ◽  
Adult Survivors ◽  
Well Being ◽  
Future Research ◽  
Relational Self ◽  
Self Identity

Clergy-perpetrated sexual abuse (CPSA) during childhood represents a tragic betrayal of trust that inflicts damage on the survivor, the family, and the parish community. Survivors often report CPSA has a disturbing impact on their self-identity. Despite intense media coverage of clergy abuse globally in the Catholic Church (and other faith communities) over several decades, relatively few empirical studies have been conducted with survivors. Beyond clinical observations and advocacy group reports, very little is known about survivors’ perceptions of how the abuse impacted their long-term self-identity. Using data collected during the 2010 Health and Well-Being Survey, this qualitative analysis represents one of the first large-scale studies with a non-clinical sample of adult male survivors of CPSA from childhood ( N = 205). The negative effects of the sexual abuse on participants were expressed across six domains of self-identity: (a) total self, (b) psychological self, (c) relational self, (d) gendered self, (e) aspirational self, and (f) spiritual self. These findings highlight the range and depth of self-suffering inflicted by this pernicious form of sexual violence. The findings are useful for developing clinical services for survivors, shaping public and institutional policies to address clergy-perpetrated sexual abuse, and guiding future research with this population.

scholarly journals Technology Acceptance in Healthcare: A Systematic Review

2021 ◽  
Vol 11 (22) ◽  
pp. 10537
Author(s):  
Adi A. AlQudah ◽  
Mostafa Al-Emran ◽  
Khaled Shaalan
Keyword(s):  
Systematic Review ◽  
Technology Acceptance ◽  
Large Scale ◽  
Empirical Studies ◽  
Influential Factors ◽  
Full Potential ◽  
Eligibility Criteria ◽  
Factors Affecting ◽  
The Usa ◽  
Healthcare Technologies

Understanding the factors affecting the use of healthcare technologies is a crucial topic that has been extensively studied, specifically during the last decade. These factors were studied using different technology acceptance models and theories. However, a systematic review that offers extensive understanding into what affects healthcare technologies and services and covers distinctive trends in large-scale research remains lacking. Therefore, this review aims to systematically review the articles published on technology acceptance in healthcare. From a yield of 1768 studies collected, 142 empirical studies have met the eligibility criteria and were extensively analyzed. The key findings confirmed that TAM and UTAUT are the most prevailing models in explaining what affects the acceptance of various healthcare technologies through different user groups, settings, and countries. Apart from the core constructs of TAM and UTAUT, the results showed that anxiety, computer self-efficacy, innovativeness, and trust are the most influential factors affecting various healthcare technologies. The results also revealed that Taiwan and the USA are leading the research of technology acceptance in healthcare, with a remarkable increase in studies focusing on telemedicine and electronic medical records solutions. This review is believed to enhance our understanding through a number of theoretical contributions and practical implications by unveiling the full potential of technology acceptance in healthcare and opening the door for further research opportunities.

scholarly journals Better estimation of SNP heritability from summary statistics provides a new understanding of the genetic architecture of complex traits

2018 ◽  
Author(s):  
Doug Speed ◽  
David J Balding
Keyword(s):  
Complex Traits ◽  
Genetic Architecture ◽  
Large Scale ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Summary Statistics ◽  
Confounding Bias ◽  
Conserved Regions ◽  
Genome Wide ◽  
Variation Explained

LD Score Regression (LDSC) has been widely applied to the results of genome-wide association studies. However, its estimates of SNP heritability are derived from an unrealistic model in which each SNP is expected to contribute equal heritability. As a consequence, LDSC tends to over-estimate confounding bias, under-estimate the total phenotypic variation explained by SNPs, and provide misleading estimates of the heritability enrichment of SNP categories. Therefore, we present SumHer, software for estimating SNP heritability from summary statistics using more realistic heritability models. After demonstrating its superiority over LDSC, we apply SumHer to the results of 24 large-scale association studies (average sample size 121 000). First we show that these studies have tended to substantially over-correct for confounding, and as a result the number of genome-wide significant loci has under-reported by about 20%. Next we estimate enrichment for 24 categories of SNPs defined by functional annotations. A previous study using LDSC reported that conserved regions were 13-fold enriched, and found a further twelve categories with above 2-fold enrichment. By contrast, our analysis using SumHer finds that conserved regions are only 1.6-fold (SD 0.06) enriched, and that no category has enrichment above 1.7-fold. SumHer provides an improved understanding of the genetic architecture of complex traits, which enables more efficient analysis of future genetic data.

scholarly journals M. cerebralis establishment and spread: A graphical synthesis

2021 ◽  
Author(s):  
Pouria Ramazi ◽  
Samuel Matthias Fischer ◽  
Julie Alexander ◽  
Clayton James ◽  
Andrew J. Paul ◽  
...  
Keyword(s):  
Large Scale ◽  
Graphical Model ◽  
Empirical Studies ◽  
Model Development ◽  
Ecological Impacts ◽  
Surveillance Program ◽  
Whirling Disease ◽  
Spread Model ◽  
Considerable Impact ◽  
Economic Constraints

M. cerebralis is the parasite causing whirling disease, which has dramatic ecological impacts due to its potential to cause high mortality in salmonids. The large-scale efforts, necessary to underpin an effective surveillance program, have practical and economic constraints. There is, hence, a clear need for models that can predict the parasite spread. Model development, however, often heavily depends on knowing influential variables and governing mechanisms. We have developed a graphical model for the establishment and spread of M. cerebralis by synthesizing experts’ opinion and empirical studies. First, we conducted a series of workshops with experts to identify variables believed to impact the establishment and spread of the parasite M. cerebralis and visualized their interactions via a directed acyclic graph. Then we refined the graph by incorporating empirical findings from the literature. The final graph’s nodes correspond to variables whose considerable impact on M. cerebralis establishment and spread is either supported by empirical data or confirmed by experts, and the graph’s directed edges represent direct causality or strong correlation. This graphical model facilitates communication and education of whirling disease and provides an empirically driven framework for constructing future models, especially Bayesian networks.

Public communication about home burglary prevention in Belgium

2007 ◽  
Vol 30 (4) ◽  
pp. 567-586 ◽  
Author(s):  
Dave Gelders ◽  
Hans Peeraer ◽  
Jelle Goossens
Keyword(s):  
Content Analysis ◽  
Focus Group ◽  
Police Officers ◽  
Large Scale ◽  
Empirical Studies ◽  
Public Communication ◽  
Focus Group Interviews ◽  
Content Type ◽  
Group Interviews ◽  
Media Mix

PurposeThe purpose of this paper is to gain insight into the content, format and evaluation of printed public communication from police officers and governments regarding home burglary prevention in Belgium.Design/methodology/approachThe content and format in this paper is analyzed through content analysis of 104 printed communication pieces in the Belgian province of Flemish‐Brabant in 2005. The evaluation is analyzed through five focus group interviews among professionals and common citizens.FindingsThe paper finds that police zones significantly differ in terms of communication efforts. The media mix is not diverse with poor collaboration between police officers and government information officers, while intermediaries (i.e. architects) are rarely used, culminating in poor targeted communication.Research limitations/implicationsThe paper shows that only printed communication is analyzed and more large‐scale empirical research is desired.Practical implicationsThe paper shows that a richer media mix, more targeted communication, more national communication support and additional dialogue between and training of police officers and communication with professionals are advisable.Originality/valueThis paper combines two empirical studies and methods (content analysis and focus group interviews), resulting in a series of recommendations for further inquiry and future action.

Model Track Studies by Ground Penetrating Radar (GPR) on Ballast With Different Fouling and Geotechnical Properties

2015 ◽  
Author(s):  
Hamed Faghihi Kashani ◽  
Carlton L. Ho ◽  
Charles P. Oden ◽  
Stanley S. Smith
Keyword(s):  
Ground Penetrating Radar ◽  
Large Scale ◽  
Empirical Studies ◽  
Geotechnical Properties ◽  
Maintenance Cost ◽  
Non Invasive ◽  
Section Area ◽  
University Of Massachusetts ◽  
Ground Penetrating ◽  
The University

In recent years there has been an increase in the knowledge of, and need for, non-invasive monitoring of ballast in order to identify the problematic sections of track and decrease the maintenance cost. Various technologies such as Ground Penetrating Radar (GPR) are becoming accepted for investigating the condition of ballast. However since these techniques were not originally developed for engineering applications, their applicability in ballast evaluations can be sometimes uncertain. Continued empirical studies and condition specific calibrations are needed to demonstrate repeatable and quantifiable results. In this study large-scale track models with trapezoidal section area were constructed at the University of Massachusetts to investigate the effects of breakdown fouling, and the effects of changing geotechnical properties on GPR traces. This paper presents the design and construction of large scale track models, and methods used for GPR data collection. GPR data are presented in this paper that demonstrate sensitivity to the track model properties and variables. In particular, the experiments are being used to evaluate changes in GPR data with changing geotechnical properties of the ballast such as density, water content, grain size distribution (GSD), and fouling percentage.

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