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31.
Living in groups is a widespread phenomenon in many animal taxa. The reduction of predation risk is thought to be an important cause for the formation of groups. Consequently, grouping behavior is particularly pronounced during vulnerable life stages, i.e., as juveniles. However, group living does not only provide benefits but also imposes costs on group members, e.g., increased competition for food. Thus, benefits of grouping behavior might not be evident when predation risk is absent. The adaptive significance of living and also developing in a group independent from predation risk has received relatively little attention although this might have important implications on the evolution and maintenance of group living. The first aim of the present study was to examine whether the social environment affects juvenile performance in the cichlid fish Pelvicachromis taeniatus and, secondly, whether kinship affects social behavior. Kin selection theory predicts benefits from grouping with kin. Here, we demonstrate that juveniles reared in a group grow on average faster compared to juveniles reared in isolation under standardized laboratory conditions without predation risk. Furthermore, we found significant differences in social behavior between juveniles reared in a group and reared in isolation. Fish reared in isolation were significantly more aggressive and less willing to shoal than group-reared fish. As expected, genetic relatedness influenced social behavior in group-reared fish as well: dyads of juveniles consisting of kin showed increased group cohesiveness compared to non-kin dyads. We discuss the potential benefits of group living in general and living with kin in particular. 相似文献
32.
Frank D. Belschak Gabriele Jacobs Steffen R. Giessner Kate E. Horton P. Saskia Bayerl 《组织行为杂志》2020,41(9):830-850
Large-scale, long-term change initiatives take time to unfold, which can be a source of uncertainty and strain. Investigating the initial 19 months of a large-scale change, we argue that during these stages, employees' change-related beliefs become more negative over time, which negatively affects their work engagement and, ultimately, increases their turnover intentions. Furthermore, we investigate the impact of a trait, Machiavellianism, on change reactions and propose that employees high in Machiavellianism react more negatively during change processes as they are especially susceptible to uncertainty and stress. We test our (cross-level) moderated mediation model in a three-wave longitudinal study among employees undergoing a large-scale change (T1: n = 1,602; T2: n = 1,113; T3: n = 759). We find that employees' beliefs about the impact and value of the change are indeed negatively related to change duration and that decreases in these perceptions come with a decline in engagement and increases in turnover intentions. Moreover, employees high in Machiavellianism react more strongly to a deterioration in change-related beliefs, showing stronger reductions in engagement and stronger increases in turnover intentions than employees low in Machiavellianism. Our study offers explanations for the negative effects of large-scale changes including an explanatory factor for disparate employee reactions to change over time. 相似文献
33.
Margaret M. Hinrichs Thomas P. Seager Sarah J. Tracy Mark A. Hannah 《The Environmentalist》2017,37(2):144-155
Current trends validate the notion that multifaceted, multimodal interdisciplinary collaborations lead to increased research productivity in publications and citations, compared to those achieved by individual researchers. Moreover, it may be that scientific breakthroughs are increasingly achieved by interdisciplinary research teams. Nonetheless, despite the perceived importance of collaboration and its bibliometric benefits, today’s scientists are still trained to be autonomous, work individually, and encourage their graduate students to do the same—perpetuating values which impede the creation of collaborative space between disciplines. As a consequence, scientists working in teams typically report serious obstacles to collaboration. This paper builds off of recent recommendations from a 2015 National Academies report on the state of team science which emphasizes greater definition of roles, responsibility, accountability, goals, and milestones. However, these recommendations do not address the subjective, relational components of collaboration which can drive innovation and creativity. The relational side of collaboration is key to understanding the capacity and capabilities of the knowledge workers, such as scientists and engineers, who comprise interdisciplinary research teams. The authors’ recommendations, grounded in organizational communication and knowledge worker literature, include a renewed focus on the process of organizing through communication rather than focusing on organization as an outcome or consequence of teamwork, leading and cultivating team members rather than managing them, and the need to address self-driven, rather than external, motivations to engage in knowledge work. 相似文献
34.
Hydrothermal ecosystems are of high conservation and scientific value, but they are sensitive to external perturbations that result from development. This study examines the composition of vegetation at four plots at the Wairakei-Tauhara geothermal field, New Zealand, using the Scott height-frequency method, ground temperatures at 0.1- and 1-m depth, soil pH, and photographic surveys. It highlights the response of plant communities, in particular that of Kunzea ericoides var. microflora, in terms of composition, structure, and biomass index values, measures changes in ground temperature, as well as provides baseline data against which to compare future changes. It was found that optimal growing conditions for K. ericoides var. microflora are at temperatures above background conditions with a slightly acidic pH. Plots with cooler, less acidic conditions support more diverse plant communities, which also promote the establishment of invasive species. This suggests that the largest threats to thermotolerant vegetation in New Zealand, including K. ericoides var. microflora, are further decreases in ground temperature because the establishment of invasive species may result in thermolerant vegetation being out-competed in hydrothermal ecosystems. Recognising and understanding the ecological diversity and dynamics of hydrothermal ecosystems, as well as acknowledging the competing interests between development and conservation, is key to the management and protection of these areas. 相似文献
35.
Saskia Buchholz Andreas Krein Jürgen Junk Günther Heinemann Lucien Hoffmann 《Environmental Modeling and Assessment》2013,18(3):271-283
The aim of this study is to investigate the air pollution situation in an urban area in southwestern Luxembourg and to simulate annual NO2 and PM10 concentrations in response to changes in meteorological conditions and emissions using a Gaussian dispersion model. Simulations are carried out for the years 1998–2006. Emission scenarios related to road transport and nonindustrial combustion are performed in order to predict changes of air pollution levels. Road transport is by far the most important local emission source in the study area. Scenarios with more stringent emission standards for vehicles, less traffic, and fewer heavy-duty vehicles lead to reductions of NOx and primary PM10 emissions. As a result, the annual NO2 concentrations are decreasing in most parts of the study area and are below the European annual limit value of 40 μg?m?3. In contrast, a scenario with increased use of wood pellets for domestic heating shows an increase in urban PM10 concentration. The year-to-year variability of meteorological conditions accounts for the same magnitude of absolute NO2 and PM10 concentration changes as the emission scenarios. The comparison with measurements located in the study area shows that the model is able to predict urban-scale annual average air pollution. The proposed application results show that the model can be appropriate for policy-driven air quality management and planning queries. 相似文献
36.
Selective Patronage and Social Justice: Local Food Consumer Campaigns in Historical Context 总被引:1,自引:1,他引:0
C. Clare Hinrichs Patricia Allen 《Journal of Agricultural and Environmental Ethics》2008,21(4):329-352
In the early 2000s, the development of local food systems in advanced industrial countries has expanded beyond creation and
support of farmers’ markets and community supported agriculture farms and projects to include targeted Buy Local Food campaigns.
Non-governmental groups in many U.S. places and regions have launched such campaigns with the intent of motivating and directing
consumers toward more local food purchasing in general. This article examines the current manifestations and possibilities
for social justice concerns in Buy Local Food campaigns, by considering them within the more general category of “selective
patronage“ campaigns. Historical campaign examples, such as Buy Union, Buy American, and Buy Black campaigns, offer instructive
comparisons to contemporary consumer campaigns promoting local food. Through examining the construction of threats, intended
beneficiaries, products to be avoided, and those to be preferentially selected, the paper demonstrates how selective patronage
campaigns have emphasized social justice needs and concerns for designated groups in ways that have been potentially exclusionary
of other disadvantaged groups and thus undermining of social justice more broadly. As a contemporary instance of “selective
patronage,“ Buy Local Food campaigns exhibit similar contradictory impulses, which are intensified by the conceptual and practical
pitfalls in designating “local.“ The article concludes by considering how the challenges and prospects for commitments to
social justice in local food consumer campaigns reinforce the importance of emerging initiatives centered on domestic fair
trade. 相似文献