Resting vs. active: a meta-analysis of the intra- and inter-specific associations between minimum, sustained, and maximum metabolic rates in vertebrates

Variation in aerobic capacity has far reaching consequences for the physiology, ecology, and evolution of vertebrates. Whether at rest or active, animals are constrained to operate within the energetic bounds determined by their minimum (minMR) and sustained or maximum metabolic rates (upperMR). MinMR and upperMR can differ considerably among individuals and species but are often presumed to be mechanistically linked to one another. Specifically, minMR is thought to reflect the idling cost of the machinery needed to support upperMR. However, previous analyses based on limited datasets have come to conflicting conclusions regarding the generality and strength of their association. Here we conduct the first comprehensive assessment of their relationship, based on a large number of published estimates of both the intra-specific (n = 176) and inter-specific (n = 41) phenotypic correlations between minMR and upperMR, estimated as either exercise-induced maximum metabolic rate (VO2max), cold-induced summit metabolic rate (Msum), or daily energy expenditure (DEE). Our meta-analysis shows that there is a general positive association between minMR and upperMR that is shared among vertebrate taxonomic classes. However, there was stronger evidence for intra-specific correlations between minMR and Msum and between minMR and DEE than there was for a correlation between minMR and VO2max across different taxa. As expected, inter-specific correlation estimates were consistently higher than intra-specific estimates across all traits and vertebrate classes. An interesting exception to this general trend was observed in mammals, which contrast with birds and exhibit no correlation between minMR and Msum. We speculate that this is due to the evolution and recruitment of brown fat as a thermogenic tissue, which illustrates how some species and lineages might circumvent this seemingly general association. We conclude that, in spite of some variability across taxa and traits, the contention that minMR and upperMR are positively correlated generally holds true both within and across vertebrate species. Ecological and comparative studies should therefore take into consideration the possibility that variation in any one of these traits might partly reflect correlated responses to selection on other metabolic parameters

Contexts of diffusion: Adoption of research synthesis in Social Work and Women's Studies

Texts reveal the subjects of interest in research fields, and the values, beliefs, and practices of researchers. In this study, texts are examined through bibliometric mapping and topic modeling to provide a birds eye view of the social dynamics associated with the diffusion of research synthesis methods in the contexts of Social Work and Women's Studies. Research synthesis texts are especially revealing because the methods, which include meta-analysis and systematic review, are reliant on the availability of past research and data, sometimes idealized as objective, egalitarian approaches to research evaluation, fundamentally tied to past research practices, and performed with the goal informing future research and practice. This study highlights the co-influence of past and subsequent research within research fields; illustrates dynamics of the diffusion process; and provides insight into the cultural contexts of research in Social Work and Women's Studies. This study suggests the potential to further develop bibliometric mapping and topic modeling techniques to inform research problem selection and resource allocation.Comment: To appear in proceedings of the 2014 International Conference on Social Computing, Behavioral-Cultural Modeling, and Prediction (SBP2014

Consistent alleviation of abiotic stress with silicon addition: a meta-analysis

1. Hundreds of single species studies have demonstrated the facility of silicon (Si) to alleviate diverse abiotic stresses in plants. Understanding of the mechanisms of Si-mediated stress alleviation is progressing, and several reviews have brought information together. A quantitative assessment of the alleviative capacity of Si, however, which could elucidate plant Si function more broadly, was lacking. 2. We combined the results of 145 experiments, predominantly on agricultural species, in a meta-analysis to statistically assess the responses of stressed plants to Si supply across multiple plant families and abiotic stresses. We interrogated our database to determine whether stressed plants increased in dry mass and net assimilation rate, oxidative stress markers were reduced, antioxidant responses were increased and whether element uptake showed consistent changes when supplied with Si. 3. We demonstrated that across plant families and stress types, Si increases dry weight, assimilation rate and chlorophyll biosynthesis and alleviates oxidative damage in stressed plants. In general, results indicated that plant family (as a proxy for accumulator type) and stress type had significant explanatory power for variation in responses. The consistent reduction in oxidative damage was not mirrored by consistent increases in antioxidant production, indicative of the several different stress alleviation mechanisms in which Si is involved. Silicon addition increased K in shoots, decreased As and Cd in roots and Na and Cd in shoots. Silicon addition did not affect Al, Ca or Mn concentration in shoots and roots of stressed plants. Plants had significantly lower concentrations of Si accumulated in shoots but not in roots when stressed. 4. Meta-analyses showed consistent alleviation by Si of oxidative damage caused by a range of abiotic stresses across diverse species. Our findings indicate that Si is likely to be a useful fertilizer for many crops facing a spectrum of abiotic stresses. Similarities in responses across families provide strong support for a role of Si in the alleviation of abiotic stress in natural systems, where it has barely been explored. We suggest this role may become more important under a changing climate and more experiments using non-agricultural species are now needed

Afforestation Effects on Soil Carbon Storage in the United States: A Synthesis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152514/1/saj2sssaj20120236.pd

Effectiveness of agri‐environmental management on pollinators is moderated more by ecological contrast than by landscape structure or land‐use intensity

Agri-environment management (AEM) started in the 1980s in Europe to mitigate biodiversity decline, but the effectiveness of AEM has been questioned. We hypothesize that this is caused by a lack of a large enough ecological contrast between AEM and non-treated control sites. The effectiveness of AEM may be moderated by landscape structure and land-use intensity. Here, we examined the influence of local ecological contrast, landscape structure and regional land-use intensity on AEM effectiveness in a meta-analysis of 62 European pollinator studies. We found that ecological contrast was most important in determining the effectiveness of AEM, but landscape structure and regional land-use intensity played also a role. In conclusion, the most successful way to enhance AEM effectiveness for pollinators is to implement measures that result in a large ecological improvement at a local scale, which exhibit a strong contrast to conventional practices in simple landscapes of intensive land-use regions

On the Reliability of Meta-Analytic Reviews

The article addresses the issue of intercoder reliability in meta-analyses. The current practice of reporting a single, mean intercoder agreement score in meta-analytic research leads to systematic bias and overestimates the true reliability. An alternative approach is recommended in which average intercoder agreement scores or other reliability statistics are calculated within clusters of coded variables. These clusters form a hierarchy in which the correctness of coding decisions at a given level of the hierarchy is contingent on decisions made at higher levels. Two separate studies of intercoder agreement in meta-analysis are presented to assess the validity of the model.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67840/2/10.1177_0193841X9301700303.pd

Practitioner Review: Therapist variability, patient-reported therapeutic alliance, and clinical outcomes in adolescents undergoing mental health treatment - a systematic review and meta-analysis

Background: Previous meta-analyses have only found small correlations (r=0.10 to r=0.19) between therapeutic alliance and clinical outcomes in samples of adolescents receiving psychological therapy. Although study-level variables have been found to moderate this, little is known about the impact of therapist variability. The present meta-analysis aimed to address this gap by using patient-therapist ratio as a moderator variable. Methods: Contrary to previous reviews of adolescent alliance, individual effect sizes were extracted using a pre-registered conceptual hierarchy. Controlling for treatment-level confounds, a random effects meta-analysis assessed the moderating effect of patient-therapist ratio on the alliance-outcome relationship in pre-defined single-predictor and multi-predictor meta-regressions.Results: The alliance-outcome relationship was found to be larger than previously thought (k=28, N=2911, r=0.29, 95% Confidence Interval 0.21, 0.37;

The Resilient Organization: A Meta-Analysis of the Effect of Communication on Team Diversity and Team Performance

The Input-Process-Output framework is adopted to examine the impact of diversity attributes (the input) on communication (the process) and their influence on performance (the output), to understand the internal group/team working mechanisms of organizational resilience. A meta-analysis of 174 correlations from 35 empirical studies undertaken over 35 years (1982-2017) showed that members of a team who have different experiences are more likely to share information and communicate openly when they deal with a task that requires collaboration outside the team. This supports the view that organizations are more resilient by being more closely connected with the external environment. Differences in social categories tend to favor openness of communication, especially in the case of age diversity and race/ethnicity diversity. An increase in openness of communication is likely to enhance team performance, particularly for small and medium sized teams operating in manufacturing industries, while frequency of communication can be beneficial for both large and medium sized teams working in the high technology industry. The positive workings of these associations form the resilient organization