scholarly journals A meta-analysis of relationships between polychlorinated biphenyl exposure and performance across studies of free-ranging tree swallows ( Tachycineta bicolor )

2016 ◽  
Vol 3 (4) ◽  
pp. 150634 ◽  
Author(s):  
Frances Bonier
Keyword(s):  
Reproductive Success ◽  
Polychlorinated Biphenyl ◽  
Meta Analysis ◽  
Field Studies ◽  
Tree Swallow ◽  
Tree Swallows ◽  
Bioindicator Species ◽  
And Performance ◽  
Free Ranging ◽  
Pcb Exposure

Habitats worldwide are increasingly being degraded by human activities, with environmental pollution representing a significant threat to species and ecosystems. The presence of persistent organic chemicals, such as polychlorinated biphenyls (PCBs), has generated concern. Captive experiments and field studies have reported some evidence for detrimental effects of PCB exposure, but also significant variation across studies and species. Here, I use a meta-analytical approach to combine findings across 10 studies investigating effects of PCBs on performance (e.g. reproductive success, offspring growth) in free-ranging tree swallows, a common bioindicator species that accumulates high levels of PCBs at some contaminated sites. Contrary to predictions, five complementary analyses revealed no significant negative association between PCB exposure and performance in tree swallows. In fact, in one analysis, increased PCB exposure was associated with improved reproductive success. Possible explanations for these findings include several limitations of field studies, variation in the toxicity of different PCB congener mixtures found across sites included in the analysis, and variation in the degree of tolerance of PCB exposure among species (with high tolerance found in tree swallows). At this point, the available evidence from field studies does not demonstrate negative impacts of PCB exposure on tree swallow performance.

Changes in polychlorinated biphenyl (PCB) exposure in tree swallows (Tachycineta bicolor) nesting along the Sheboygan River, WI, USA

Ecotoxicology ◽  
2014 ◽  
Vol 23 (8) ◽  
pp. 1439-1446 ◽  
Author(s):  
Christine M. Custer ◽  
Thomas W. Custer ◽  
Sean M. Strom ◽  
Kathleen A. Patnode ◽  
J. Christian Franson
Keyword(s):  
Polychlorinated Biphenyl ◽  
Tachycineta Bicolor ◽  
Tree Swallows ◽  
Pcb Exposure

scholarly journals Why Grit Requires Perseverance AND Passion to Positively Predict Performance

2018 ◽  
Author(s):  
Jon Jachimowicz ◽  
Andreas Wihler ◽  
Erica Bailey ◽  
Adam Galinsky
Keyword(s):  
United States ◽  
Meta Analysis ◽  
Empirical Support ◽  
Field Studies ◽  
The United States ◽  
Current Theory ◽  
The Public ◽  
Contradictory Evidence ◽  
And Performance ◽  
Public Imagination

Grit has captured the public imagination and crept into educational policy throughout the United States. However, because prior studies linking grit and performance are beset by contradictory evidence, commentators increasingly state that grit is over-hyped. We propose that the inconsistency between grit's initial promise and its subsequent lack of empirical support has occurred because grit's measurement has not matched its definition. Although grit is defined as the combination of perseverance and passion, its measurement has focused on perseverance and has not adequately captured passion. In a meta-analysis of 127 studies and two field studies, we show that passion is a key component of grit. The current theory and results suggest that perseverance without passion isn't grit, but merely a grind.

Tree swallow diet in relation to wetland acidity

1991 ◽  
Vol 69 (10) ◽  
pp. 2629-2637 ◽  
Author(s):  
Peter J. Blancher ◽  
Donald K. McNicol
Keyword(s):  
Reproductive Success ◽  
Breeding Season ◽  
Major Change ◽  
Tachycineta Bicolor ◽  
Tree Swallow ◽  
Total Biomass ◽  
Tree Swallows ◽  
Nestling Diet ◽  
Aquatic Food ◽  
Emerging Insects

We examined 12 825 prey of tree swallows (Tachycineta bicolor) northeast of Sudbury, Ontario, to observe the importance of aquatic food and the influence of wetland pH on swallow diet during the breeding season. Items of aquatic origin constituted most of the biomass in diets of both nestlings and adults. Molluscs and Ephemeroptera (mayflies), whose distributions in the study wetlands were strongly influenced by pH, were eaten by swallows, particularly nestlings. The major change in nestling diet in relation to wetland acidity was a decrease in mayflies and a corresponding increase in aquatic Diptera at wetlands of lower pH. The number of aquatic taxa eaten by nestlings was lowest at acidic wetlands. The total biomass of emerging insects captured at acidic wetlands was not lower than at wetlands of higher pH, and in fact tended to be greater. The rate at which swallows fed their young and the amount of food fed to nestlings were not related to wetland pH or other wetland characteristics. Nevertheless, the reduced availability of calcium-rich foods at acidic wetlands and the change in types of food available may play a role in the reduced reproductive success of swallows at acidic wetlands.

Replication of the Superstition and Performance Study by

2014 ◽  
Vol 45 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Robert J. Calin-Jageman ◽  
Tracy L. Caldwell
Keyword(s):  
Task Difficulty ◽  
Statistical Power ◽  
Meta Analysis ◽  
A Priori ◽  
Significant Heterogeneity ◽  
Performance Study ◽  
Improve Performance ◽  
Research Designs ◽  
Series Of Experiments ◽  
And Performance

A recent series of experiments suggests that fostering superstitions can substantially improve performance on a variety of motor and cognitive tasks ( Damisch, Stoberock, & Mussweiler, 2010 ). We conducted two high-powered and precise replications of one of these experiments, examining if telling participants they had a lucky golf ball could improve their performance on a 10-shot golf task relative to controls. We found that the effect of superstition on performance is elusive: Participants told they had a lucky ball performed almost identically to controls. Our failure to replicate the target study was not due to lack of impact, lack of statistical power, differences in task difficulty, nor differences in participant belief in luck. A meta-analysis indicates significant heterogeneity in the effect of superstition on performance. This could be due to an unknown moderator, but no effect was observed among the studies with the strongest research designs (e.g., high power, a priori sampling plan).

Team Learning Behaviors and Performance: A Meta-Analysis of Direct Effects and Moderators

2021 ◽  
pp. 105960112110169
Author(s):  
Christopher W. Wiese ◽  
C. Shawn Burke ◽  
Yichen Tang ◽  
Claudia Hernandez ◽  
Ryan Howell
Keyword(s):  
Team Performance ◽  
Team Learning ◽  
Task Complexity ◽  
Meta Analysis ◽  
Sample Type ◽  
Learning Behaviors ◽  
Learning Teams ◽  
And Performance ◽  
The Relationship ◽  
Team Familiarity

Under what conditions do team learning behaviors best predict team performance? The current meta-analytic efforts synthesize results from 113 effect sizes and 7758 teams to investigate how different conceptualizations (fundamental, intrateam, and interteam), team characteristics (team size and team familiarity), task characteristics (interdependence, complexity, and type), and methodological characteristics (students vs. nonstudents and measurement choice) affect the relationship between team learning behaviors and team performance. Our results suggest that while different conceptualizations of team learning behaviors independently predict performance, only intrateam learning behaviors uniquely predict performance. A more in-depth investigation into the moderating conditions contradicts the familiar adage of “it depends.” The strength of the relationship between intrateam learning behaviors and team performance did not depend on team familiarity, task complexity, or sample type. However, our results suggested this relationship was stronger in larger teams, teams with moderate task interdependence, teams performing project/action tasks, and studies that use measures that capture a wider breadth of the team learning behavior construct space. These efforts suggest that common boundary conditions do not moderate this relationship. Scholars can leverage these results to develop more comprehensive theories addressing the different conceptualizations of team learning behaviors as well as providing clarity on the scenarios where team learning behaviors are most needed. Further, practitioners can use our results to develop more guided team-based policies that can overcome some of the challenges of forming and developing learning teams.

Alliance experience and performance outcomes: A meta-analysis

2021 ◽  
pp. 147612702098287
Author(s):  
Peng Wang ◽  
Xu Jiang ◽  
Maggie Chuoyan Dong
Keyword(s):  
Strategic Alliance ◽  
Meta Analysis ◽  
Group Analysis ◽  
Performance Outcomes ◽  
Country Level ◽  
Different Types ◽  
Performance Consequences ◽  
Controversial Topic ◽  
Alliance Experience ◽  
And Performance

Alliance experience has been a frequent topic in strategic alliance research in recent decades. Nonetheless, its performance consequences, either as a whole or differentiated into general versus partner-specific alliance experience, are neither theoretically clear nor empirically consistent. We use a range of meta-analytic techniques to integrate the empirical findings of 143 studies and provide a more conclusive assessment compared to prior research. Our study thus addresses a long-standing, understudied, and controversial topic: the distinction between the two types of alliance experiences. Going beyond traditional sub-group analysis, we reveal the contextual contingencies by examining how different types of alliance experiences and performance outcomes jointly affect the alliance experience–performance relationship. Moreover, we identify critical country-level institutional contingencies that moderate the focal effect.

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