scholarly journals Are there Physical Linkages between Genes that have Synergistic Fitness Effects?

2020 ◽  
Author(s):  
Juliet Byrnes ◽  
John Murray ◽  
Mark M. Tanaka ◽  
Ben Goldys ◽  
Antony Bellanto ◽  
...  
Keyword(s):  
Meiotic Recombination ◽  
Genetic Variants ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Epistatic Effect ◽  
Epistatic Interactions ◽  
Fitness Effects ◽  
Fisher Model ◽  
Strongly Connected ◽  
The Relationship

AbstractMany of the effects on fitness in population genetics are due not to single locations in the genome, but to the interaction of genetic variants at multiple locations in the genome. Of particular interest are ‘completely epistatic’ interactions, where a combination of genetic variants is required to produce an effect, and the effect cannot occur with any other combination. In diploids, epistasis is strongly connected to meiotic recombination, a process which can both assemble and destroy beneficial combinations of genetic variants. Additionally, epistatic interactions can be hard to detect in empirical studies, and mathematical models of epistasis and recombination are challenging to analyse, so despite their ubiquity epistatic interactions are regularly not considered. As a result, there is little consensus on when high levels of recombination might be expected, or how strongly recombination affects beneficial or deleterious fitness effects controlled by epistatic interactions. We address this question by conducting a meta-analysis and simulations. The meta-analysis used data drawn and curated from Drosophila melanogaster studies in Flybase. We extracted studies relating genetic combinations and phenotypically detectable effects on fitness, then analysed the relationship between the rate of recombination and effect on fitness with a statistical model. We also ran simulations under a two-locus Wright-Fisher model with recombination and epistatic selection. The results of both approaches indicated a tendency for genetic combinations with an epistatic effect on fitness to occur in an environment of reduced meiotic recombination. Two possible explanations for this are that the variants controlling such interactions are selected for in regions where there is little recombination, or that such interactions lead to selection for lower rates of recombination in the regions where those variants appear.

Enhancing Occupational Performance through Occupationally Embedded Exercise: A Meta-Analytic Review

1997 ◽  
Vol 17 (1) ◽  
pp. 25-47 ◽  
Author(s):  
Keh-Chung Lin ◽  
Ching-Yi Wu ◽  
Linda Tickle-Degnen ◽  
Wendy Coster
Keyword(s):  
Occupational Therapy ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Theory And Practice ◽  
Occupational Performance ◽  
Nelson Model ◽  
Theoretical Inquiry ◽  
Analytic Review ◽  
The Impact ◽  
The Relationship

Occupation or purposeful activity is the unique historical root of occupational therapy and is thought to enhance health and prevent disability. Nelson's (1988) recent conceptual framework of occupation consolidates the beliefs of occupational therapy. One focus for empirical research and theoretical inquiry is the relationship between occupational form and occupational performance. This article critically analyzes this important part of the Nelson model and meta-analytically summarizes findings of the empirical studies that have examined this relationship. Results of the meta-analysis showed a substantial relationship of occupational form to occupational performance (weighted mean effect size r=0.50) in support of the proposition of the Nelson model that occupation can be analyzed in terms of the relationship between occupational form and occupational performance. The impact of potential moderators on the study findings is explored. Implications for occupational therapy theory and practice are discussed.

scholarly journals Stakeholder Pressures and Corporate Environmental Strategies: A Meta-Analysis

2020 ◽  
Vol 12 (3) ◽  
pp. 1172 ◽  
Author(s):  
Lixiang Wang ◽  
Weian Li ◽  
Lujun Qi
Keyword(s):  
Manufacturing Industry ◽  
Practical Implication ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Corporate Sustainability ◽  
Developed Countries ◽  
Manufacturing Firms ◽  
Environmental Strategies ◽  
Stakeholder Pressures ◽  
The Relationship

Stakeholder pressures and corporate environmental strategies continue to be important topics of corporate sustainability. Limited by sample size, there is a lack of general conclusions on which groups of stakeholder pressures are the main drivers of environmental strategies. Amassing a database of 58 empirical studies, the authors divided stakeholder pressures into four groups—internal, coercive, market, and social pressure—and explored the relationship between different pressures and environmental strategies by conducting a meta-analysis. The main result shows that internal pressure is the main driver of environmental strategies. Further empirical results show that stakeholder pressures could have a larger effect on corporate environmental strategies in developed countries and that non-manufacturing firms could change their environmental strategies more easily than manufacturing firms. The results provide the practical implication that a green industry transition is strongly needed in the manufacturing industry, especially for polluting industries, and that firms in polluting industries should implement environmental strategy changes in the future. This paper contributes to clarifying the relationship between stakeholder pressures and corporate environmental strategies based on a meta-analysis.

scholarly journals Prognostic Role of c-Met Overexpression in High Grade Glioma: a Meta-analysis

2019 ◽  
Author(s):  
Bo Wu ◽  
Yuhan Ma ◽  
Sheng Zhong ◽  
Junliang Ge ◽  
Shanshan Jiang ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Progression Free Survival ◽  
High Grade Glioma ◽  
High Grade ◽  
Poor Overall Survival ◽  
Prognostic Analysis ◽  
Oncomine Database ◽  
Strongly Connected ◽  
The Relationship

AbstractObjectivesThis study aims to assess the relationship between the expression of c-Met and the prognosis of high grade glioma patients.MethodThe MET proto-oncogene encoded c-Met protein. The gene expression data of 325 patients were downloaded from CGGA. The Oncomine database analysis and the prognosis analysis were conducted. Besides, meta-analysis was also performed to confirm the conclusion.ResultOncomine database was identified and analyzed and results showed that the MET copy number was obviously higher in glioblastoma than normal tissue consistently (p<0.001). The prognostic analysis of 325 high grade glioma samples showed that high c-Met expression patients had poor overall survival (OS) and progression free survival (PFS) than the low c-Met expression patients dramatically (HR, 2.223; 95% CI: 1.662 to 2.974; P<0.0001 and HR, 2.089; 95% CI: 1.578 to 2.770; P<0.0001). 6 studies involving 503 patients were included in the meta-analysis. The pooled results indicated that the high expression of c-Met was not significantly associated with OS (HR =1.01, 95% CI:0.93-1.09), but strongly connected with shorter PFS (HR =1.92, 95% CI:1.42-2.58, p<0.01).Conclusionc-Met overexpression has correlation with poor prognosis of high grade glioma patients.

scholarly journals Insect-host control of obligate, intracellular symbiont density

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Mathilda Whittle ◽  
Antoine M. G. Barreaux ◽  
Michael B. Bonsall ◽  
Fleur Ponton ◽  
Sinead English
Keyword(s):  
Empirical Studies ◽  
Limited Capacity ◽  
Tight Control ◽  
Obligate Intracellular ◽  
Fitness Effects ◽  
Intracellular Symbiont ◽  
Using Data ◽  
Future Work ◽  
The Relationship ◽  
Self Replication

Many insects rely on intracellular bacterial symbionts to supplement their specialized diets with micronutrients. Using data from diverse and well-studied insect systems, we propose three lines of evidence suggesting that hosts have tight control over the density of their obligate, intracellular bacterial partners. First, empirical studies have demonstrated that the within-host symbiont density varies depending on the nutritional and developmental requirements of the host. Second, symbiont genomes are highly reduced and have limited capacity for self-replication or transcriptional regulation. Third, several mechanisms exist for hosts to tolerate, regulate and remove symbionts including physical compartmentalization and autophagy. We then consider whether such regulation is adaptive, by discussing the relationship between symbiont density and host fitness. We discuss current limitations of empirical studies for exploring fitness effects in host–symbiont relationships, and emphasize the potential for using mathematical models to formalize evolutionary hypotheses and to generate testable predictions for future work.

Corporate social performance in family firms: a meta-analysis

2018 ◽  
Vol 8 (3) ◽  
pp. 235-273 ◽  
Author(s):  
Sergio Canavati
Keyword(s):  
Family Firms ◽  
Corporate Social Performance ◽  
Social Performance ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Content Type ◽  
The Family ◽  
Corporate Social ◽  
The Relationship

Purpose Empirical studies provide conflicting conclusions regarding the corporate social performance (CSP) of family firms. The purpose of this paper is to synthesize the existing empirical evidence and examine the potential role of research design and contextual factors. Design/methodology/approach A meta-analysis of existing empirical studies was performed to examine the role of sampling, measurement and contextual factors in explaining the different and often conflicting results of empirical studies in the family business literature. Findings The overall relationship between family firms and CSP is positive. The relationship between family firms and CSP is positive for private family firms but is negative for public family firms. The relationship between family firms and CSP is positive when family involvement includes both family ownership and management as opposed to only family ownership or family management. Private family firms care more and public family firms care less about the community, environment, and employees than private and public nonfamily firms. The relationship between family firms and CSP is stronger in institutional environments with weak labor and corporate governance regulatory frameworks. Research limitations/implications The operationalization of both the family firm and CSP constructs significantly predicts the magnitude and direction of the relationship between family firms and CSP. Practical implications Family firms should become more skilled at measuring and disseminating information about the firm’s CSP. Family firms should work to improve public perceptions about the CSP of family firms. Social implications Policy should encourage family firms to remain privately owned by the family. Policy should also incentivize the involvement of family owners in the management of family firms. Originality/value Although several literature reviews address the relationship between family firms and CSP, this is the first review to use the meta-analysis method. The authors contribute to the family business literature by analyzing how differences in study-, firm- and country-level factors can explain some of the variance in the results of the studies in the literature.

How organizational tenure affects innovative behavior?

2016 ◽  
Vol 7 (1) ◽  
pp. 99-126 ◽  
Author(s):  
Zhiqiang Liu ◽  
Liang Ge ◽  
Wanying Peng
Keyword(s):  
Theoretical Foundation ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Practical Skills ◽  
Innovative Behavior ◽  
Content Type ◽  
Status Hierarchy ◽  
Culture Difference ◽  
Organizational Tenure ◽  
The Relationship

Purpose – The purpose of this paper was to examine the relationship between organizational tenure and employee innovative behavior and the influence of culture difference and status-related moderators (i.e. status hierarchy and status stability) on the linkage. Design/methodology/approach – By using a meta-analysis method that included 76 empirical studies, this study examines the relationship of organizational tenure and innovative behavior. In this study, 79 samples (N = 21659) derived from 76 empirical studies that met the inclusion criteria in the meta-analysis. Findings – The results show that organizational tenure has a weak positive effect on employee innovative behavior (r = 0.04), and status hierarchy, position tenure, culture difference and measurement ways influence the relationship between the two. In addition, a three-way interaction among status hierarchy, position tenure and organizational tenure is found to jointly affect innovative behavior; specifically, for those who are low in status hierarchy and short in position tenure, their organizational tenures are positively related to innovative behavior, but for those with a longer position tenure in organizations, their organizational tenure may relate to innovative behavior negatively, whatever their status hierarchies are (high or low). This study is helpful in providing theoretical foundation and practical skills to such issues regarding how to trigger innovative behavior efficiently at different career stages. Research limitations/implications – Limitations include tenure range of participants and no longitudinal samples in our studies. Future research should examine more contextual factors which influenced the relationship between organizational tenure and innovative behavior. Practical implications – The results of this study show that long organizational tenure is not negatively related to innovative behaviors. For managers, do not ignore the contribution of long-tenured employees to innovation. Through promotion or job rotation to increase employees’ job satisfaction and innovative willing. Originality/value – To authors’ knowledge, this is the first study to examine status attribute class variables in the relationship between organizational tenure on innovative behavior. The study is helpful in providing theoretical foundation and practical skills to such issues regarding how to trigger innovative behavior at different career stages correctly.

The Relationship Between Exposure to Community Violence and Psychological Distress Among Adolescents: A Meta-Analysis

2003 ◽  
Vol 18 (3) ◽  
pp. 335-352 ◽  
Author(s):  
W. Cody Wilson ◽  
Beth Spenciner Rosenthal
Keyword(s):  
Psychological Distress ◽  
Community Violence ◽  
Effect Size ◽  
Quantitative Methods ◽  
Psychological Symptoms ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Traumatic Experiences ◽  
Exposure To Community Violence ◽  
The Relationship

This article is concerned with the “size of the relationship” between exposure to chronic community violence and psychological symptoms among adolescents. It analyzes all relevant empirical studies in the published literature during the last 20 years; uses quantitative methods to summarize findings; and estimates the effect size using meta-analysis. The 37 independent samples (n = 17,322) were coded on 19 categories, including size and characteristics of sample, and characteristics of the independent and dependent variables. Findings indicate that there is a positive correlation between exposure to community violence and psychological distress; and that the effect size (r = .25) of this relationship is low-medium. The estimated effect size of the relationship points to new issues such as the characteristics of the psychosocial dynamics of resilience in the face of exposure to community violence and how exposure to community violence interacts with other potentially traumatic experiences in the producing of psychological distress.

The Longitudinal Association Between Retirement and Depression: A Systematic Review and Meta-Analysis

2021 ◽  
Author(s):  
Wentao Li ◽  
Xin Ye ◽  
Dawei Zhu ◽  
Ping He
Keyword(s):  
Systematic Review ◽  
Depressive Symptoms ◽  
Longitudinal Studies ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Developed Countries ◽  
Involuntary Retirement ◽  
Longitudinal Association ◽  
The Relationship

Abstract The purpose of this study was to collect the evidence of the relationship between retirement and depression through meta-analysis, and further analyze the heterogeneity of results. The quality of the studies was rated based on ten predefined criteria. We searched articles published between 1980 and 2020 and a total of 25 longitudinal studies were included in the meta-analysis. The meta-analysis results showed that retirement was associated with more depressive symptoms (d =0.044, 95%CI 0.008 to 0.080). The association of involuntary retirement (d = 0.180, 95%CI 0.061 to 0.299) with more depressive symptoms was stronger than voluntary retirement (d = 0.086, 95%CI -0.018 to 0.190) and regulatory retirement (d = 0.009, 95%CI -0.079 to 0.097). Retirement was significantly associated with more depressive symptoms in eastern developed countries (d = 0.126, 95%CI 0.041 to 0.210), and the association was stronger than that in western developed countries (d = 0.016, 95%CI -0.023 to 0.055). These findings suggest that the transition to retirement was associated with higher risk of depression and this association varied by the type of retirement and country. Further empirical studies need to explore the mechanism of retirement and depression and whether such association was linked with socio-economic position.

scholarly journals Meta-study on the relationship between profitability and liquidity of enterprises in macroeconomic and institutional environment

DECISION ◽  
2021 ◽  
Author(s):  
Jacek Jaworski ◽  
Leszek Czerwonka
Keyword(s):  
Institutional Environment ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Factors Affecting ◽  
Institutional Conditions ◽  
Common Effect ◽  
Two Factors ◽  
External Sources ◽  
Financial Liquidity ◽  
The Relationship

AbstractThe main aim of the paper is to determine the relationship between profitability and financial liquidity of a company using meta-analysis. This method is based on a synthesis of many previous studies with the application of econometric tools. The results of the study show that, taking into account 16 economies, it is not possible to identify a common effect describing the relationship between the profitability of enterprises and their financial liquidity measured by the current liquidity ratio. The results of individual empirical studies that underlie the meta-analysis are diverse. This means that there are moderators of the strength and direction of this dependence associated with macroeconomic and institutional conditions. We attempted to separate them by means of meta-regression. This method involves the use of a regression model, where data are derived from both meta-analysis and external sources. We diagnosed two statistically significant moderators of the strength and direction of the relationship between profitability and liquidity. These are two factors: (i) private sector crediting and (ii) capital market development. Our paper contributes to the development of the existing knowledge by summarizing and binding previous individual empirical studies on the relationship between profitability and liquidity of enterprises and identifying factors affecting this relationship. This knowledge can assist financial managers in making more efficient decisions related to liquidity and working capital management.

scholarly journals Visions for Teacher Education – Experiences from Finland [VISIONS 2011: Teacher Education]

2012 ◽  
Vol 6 (1) ◽  
Author(s):  
Sven-Erik Hansén ◽  
Liselott Forsman ◽  
Jessica Aspfors ◽  
Marina Bendtsen
Keyword(s):  
Higher Education ◽  
Teacher Education ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Global Level ◽  
Subject Specific ◽  
Characteristic Features ◽  
State Of Affairs ◽  
Constituent Elements ◽  
The Relationship

The study of teacher education in different countries reveals that many basic problems seem quite similar, although we might use different ways of categorizing and labeling the constituent elements. These differences can be specific to certain contexts, at least partly due to different traditions. To allow educationalists to understand and learn from each other on a global level, it is important to find ways of communicating these issues. The present article provides a meta-analysis of various empirical studies conducted by the authors and other Finnish researchers. The discussion entails exposing the plan and composition of characteristic features constituting Finnish teacher education. However, its ambition goes beyond describing the state of affairs: Despite a unanimous appreciation of its design, both nationally and abroad, Finnish teacher education is facing many kinds of tensions and challenges, which we in the following characterize as dilemmas. The overall aim of this article is to discuss some of these dilemmas, and also to suggest some possible ways of dealing with these. We will discuss four types of dilemmas: (1) the organization of teacher education in higher education institutions and its internal organization, (2) the relationship between general and subject-specific didactics, (3) a research-based approach versus practice-oriented approaches, and (4) the dilemma of the transition from education to work.

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