35 research outputs found

    Student Selection Criteria in Undergraduate Leadership Education Programs

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    Citizens expect and deserve effective leadership in both the public and private sectors. In today’s 24/7 information access society, high profile leaders have become a source of constant scrutiny by citizens and the media demanding results and integrity on par with the enormous salaries and fringe benefits these individuals receive

    Biology of Francisella tularensis Subspecies holarctica Live Vaccine Strain in the Tick Vector Dermacentor variabilis

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    Background: The c-proteobacterium Francisella tularensis is the etiologic agent of seasonal tick-transmitted tularemia epizootics in rodents and rabbits and of incidental infections in humans. The biology of F. tularensis in its tick vectors has not been fully described, particularly with respect to its quanta and duration of colonization, tissue dissemination, and transovarial transmission. A systematic study of the colonization of Dermacentor variabilis by the F. tularensis subsp. holarctica live vaccine strain (LVS) was undertaken to better understand whether D. variabilis may serve as an inter-epizootic reservoir for F. tularensis. Methodology/Principal Findings: Colony-reared larva, nymph, and adult D. variabilis were artificially fed LVS via glass capillary tubes fitted over the tick mouthparts, and the level of colonization determined by microbial culture. Larvae and nymphs were initially colonized with 8.860.8610 1 and 1.160.03610 3 CFU/tick, respectively. Post-molting, a significant increase in colonization of both molted nymphs and adults occurred, and LVS persisted in 42 % of molted adult ticks at 126 days post-capillary tube feeding. In adult ticks, LVS initially colonized the gut, disseminated to hemolymph and salivary glands by 21 days, and persisted up to 165 days. LVS was detected in the salivary secretions of adult ticks after four days post intra-hemocoelic inoculation, and LVS recovered from salivary gland was infectious to mice with an infectious dose 50 % of 3 CFU. LVS in gravid female ticks colonized via the intra-hemocoelic route disseminated to the ovaries and then t

    Effects of the Distribution of Female Primates on the Number of Males

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    The spatiotemporal distribution of females is thought to drive variation in mating systems, and hence plays a central role in understanding animal behavior, ecology and evolution. Previous research has focused on investigating the links between female spatiotemporal distribution and the number of males in haplorhine primates. However, important questions remain concerning the importance of spatial cohesion, the generality of the pattern across haplorhine and strepsirrhine primates, and the consistency of previous findings given phylogenetic uncertainty. To address these issues, we examined how the spatiotemporal distribution of females influences the number of males in primate groups using an expanded comparative dataset and recent advances in Bayesian phylogenetic and statistical methods. Specifically, we investigated the effect of female distributional factors (female number, spatial cohesion, estrous synchrony, breeding season duration and breeding seasonality) on the number of males in primate groups. Using Bayesian approaches to control for uncertainty in phylogeny and the model of trait evolution, we found that the number of females exerted a strong influence on the number of males in primate groups. In a multiple regression model that controlled for female number, we found support for temporal effects, particularly involving female estrous synchrony: the number of males increases when females are more synchronously receptive. Similarly, the number of males increases in species with shorter birth seasons, suggesting that greater breeding seasonality makes defense of females more difficult for male primates. When comparing primate suborders, we found only weak evidence for differences in traits between haplorhines and strepsirrhines, and including suborder in the statistical models did not affect our conclusions or give compelling evidence for different effects in haplorhines and strepsirrhines. Collectively, these results demonstrate that male monopolization is driven primarily by the number of females in groups, and secondarily by synchrony of female reproduction within groups

    Physiological Correlates of Volunteering

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    We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

    Economics of invasive species policy and management

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    Leader self -development intervention study: The impact of self -discrepancy and feedback

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    While leader self-development is becoming an increasingly important strategy for developing leaders within organizations, not much is known regarding how or why leaders self-develop. In an attempt to improve understanding of the psychological aspects behind the leader self-development process, I developed and provided an empirical examination of a model which incorporated self-discrepancy theory, identity theory, and motivational theories. A 2 x 2 quasi-experimental design was implemented within a military context, such that the focus of a self-discrepancy (ideal versus worst leader) and feedback (positive versus negative feedback) were manipulated. Mediators and dependent variables included developmental readiness, developmental goals, and self-development intentions. Findings of the study were argued to contribute to a better understanding of the leader self-development process and to provide a basis for future research. Specifically, means efficacy was found to be a significant moderator of the goal quality to intentions to develop relationship. When means efficacy was high, the relationship between goal quality and developmental intentions increased. Implications for future research and practice were discussed

    A meta-analytic review of leadership impact research: Experimental and quasi-experimental studies

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    In this study we set out to conduct a comprehensive quantitative research analysis of literature reporting results on the causal impact of leadership by focusing on examining what we refer to as ‘leadership interventions.’ We defined leadership interventions as those studies where the researcher overtly manipulated leadership as the independent variable through training, assignment, scenario or other means. Our focus included both examining experimental and quasi-experimental as well as lab and field studies conducted in public and private organizations. Our goal was to address a simple question: do leadership interventions have the intended impact and if so to what degree? We conducted a comprehensive review of the published and unpublished literature and uncovered 200 lab and field studies that met our criterion as leadership intervention studies. We report here the findings of a series of meta-analyzed effects comparing the relative impact of leadership interventions across intervention types, leadership theories, and several common dependent variables. Overall, leadership interventions produced a 66% probability of achieving a positive outcome versus a 50–50 random effect for treatment participants, but this effect varied significantly when assessing moderators such as type of leadership theory
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