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861.
Recent research indicates that sustainability assessment tools (SAT) for farms need to be contextually adapted to be acceptable and useful. Focusing specifically on social sustainability, this study sought to identify important aspects of relevance for Swedish (livestock) farmers’ social situation and compare these aspects with social indicators used in three existing SATs (RISE, SAFA, IDEA). A survey revealed that social issues of key importance for the self-reported overall life satisfaction of Swedish livestock farmers are: having a good financial situation, having a similar standard of living as others, not experiencing too much stress, having meaningful work, having decent working hours, and having a desirable family situation. Of the three SATs evaluated, RISE appears best equipped to capture the social situation of Swedish farmers but does not fully address the aspect of finding work meaningful. SAFA and IDEA both fail to capture many aspects of importance for describing the social situation of Swedish farmers. We present a novel method for testing the relevance of social indicators for farmers in a specific context. Applying this method before choosing, applying, and adapting SATs for farm-level sustainability assessments would increase the relevance of the social sustainability dimension, but deeper stakeholder engagement than offered by our survey is needed. 相似文献
862.
We provide first evidence of a link from daily air pollution exposure to sleep loss in a panel of Chinese cities. We develop a social media-based, city-level metric for sleeplessness, and bolster causal claims by instrumenting for pollution with plausibly exogenous variations in wind patterns. Estimates of effect sizes are substantial and robust. In our preferred specification a one standard deviation increase in AQI causes an 11.6% increase in sleeplessness, and for PM2.5 is 12.8%. The results sustain qualitatively under OLS estimation but are attenuated. The analysis provides a previously unaccounted for benefit of more stringent air quality regulation. It also offers a candidate mechanism in support of recent research that links daily air quality to diminished workplace productivity, cognitive performance, school absence, traffic accidents, and other detrimental outcomes. 相似文献
863.
陈哲勇 《湖南环境生物职业技术学院学报》2006,12(1):69-72
目前,我国流动人口犯罪率居高不下,严重危及着社会的安定,已成为社会各界关注的热点和解决的难点问题.流动人口犯罪的主要表现特征为主体的复杂性,犯罪的团伙性、流窜性、侵财性等.相对剥夺论是流动人口犯罪一种可行的理论阐释,有助于深化我们对流动人口犯罪的理解.加强和完善政府职能是控制流动人口犯罪行之有效的应对措施. 相似文献
864.
Vincent Dietemann Jochen Pflugfelder Stephan Härtel Peter Neumann Robin M. Crewe 《Behavioral ecology and sociobiology》2006,60(6):785-793
Social parasites exploit their host’s communication system to usurp resources and reproduce. In the honeybee, Apis mellifera, worker reproduction is regulated by pheromones produced by the queen and the brood. Workers usually reproduce when the queen is removed and young brood is absent. However, Cape honeybee workers, Apis mellifera capensis, are facultative intraspecific social parasites and can take over reproduction from the host queen. Investigating the manner in which parasitic workers compete with host queens pheromonally can help us to understand how such parasitism can evolve and how reproductive division of labour is regulated. In A. m. capensis, worker reproduction is associated with the production of queen-like pheromones. Using pheromonal contest experiments, we show that Apis mellifera scutellata queens do not prevent the production of queen-like mandibular gland compounds by the parasites. Given the importance of these pheromones in acquiring reproductive status, our data suggest that the single invasive lineage of parasitic workers occurring in the range of A. m. scutellata was selected for its superior ability to produce these signals despite the presence of a queen. Such resistance was indeed less frequent amongst other potentially parasitic lineages. Resistance to reproductive regulation by host queens is probably the key factor that facilitates the evolution of social parasitism by A. m. capensis workers. It constitutes a mechanism that allows workers to evade reproductive division of labour and to follow an alternative reproductive option by acquiring direct fitness in foreign colonies instead of inclusive fitness in their natal nests. 相似文献
865.
We study interactions between resource distributions, grouping, and diet development in foragers who learn by trial-and-error. We do this by constructing an individual-based model where individuals move and forage in groups in a 2-D space with high resource diversity and learn what to eat. By comparing diet development in different resource distributions, and in gregarious and solitary individuals, we elucidate how these factors affect patterns of diet variation. Our results indicate that different resource distributions have profound effects on learning opportunities, and thereby lead to contrasting phenomena. In uniform environments, local resource depletion by gregarious individuals, in interaction with learning, leads to diet differentiation. In patchy environments, grouping leads to enhanced diet overlap within groups and leads to differences in diet between groups. Surprisingly, mixed environments can generate all these phenomena simultaneously. Our results predict relationships between diet variation, trial-and-error learning, and resource distributions. The phenomena we describe are not evolved strategies, but arise spontaneously when groups of individuals learn to forage in certain resource distributions. This suggests that describing diet specialization or diet homogenization as the result of behavioral strategies may not always be justified. 相似文献
866.
The haploid state of males in eusocial Hymenoptera—the ants, bees, and wasps—has been proposed as a driving force in the evolution of social behavior under the assumption that haploidy results in higher susceptibility to pathogens. In this study, we present the first test of the assumptions of the “haploid male susceptibility hypothesis”. We challenged males and workers of the bumblebee Bombus terrestris with its parasite Crithidia bombi but found no differences in either initial susceptibility or the intensity of infection between haploid males and diploid females. We reviewed observational studies on parasitism in haplodiploid insects and found that in 15 out of 26 cases, haploid males had lower parasite prevalence. However, the majority of available data related to nontransmissible parasites and thus any general statements about haploid susceptibility remain unclear. Using a simulation model, we studied how diverse genetic mechanisms could affect the values for resistance; results suggest that only a phenomenon that renders workers effectively haploid, e.g., imprinting, could explain our experimental results. A more likely explanation is that, in eusocial Hymenoptera with predominantly female populations, parasites may simply become more adapted to the more common female hosts and, thus, male haploid susceptibility may be hidden due to parasite adaptation. Our results do not support the idea that the haploid susceptibility hypothesis explains the origin or maintenance of social systems in the eusocial Hymenoptera. 相似文献
867.
Varenka Lorenzi Ryan L. Earley Matthew S. Grober 《Behavioral ecology and sociobiology》2006,59(6):715-722
Sex change in marine teleost fishes is commonly regulated by social factors. In species that exhibit protogynous sex change,
such as the bluebanded goby Lythrypnus dalli, the most dominant female typically initiates sex change when a male is removed from the social group. Females can use visual,
chemical or tactile cues to assess the presence or absence of a male. The primary goal of our study was to determine whether
the olfactory and visual presence of a male versus its behavioural interactions with females were important for mediating
sex change. We exposed females to three different treatments: absence of a male, presence of a male that could physically
interact with her and presence of a male behind a barrier that allowed visual and olfactory interactions but prohibited physical
interactions. Sex change occurred in the absence of a male but not in the presence of a male that could physically interact
with the female. The presence of a male behind the barrier did not prevent sex change but affected the timing of sex change.
Season appeared to affect the latency to initiate male typical courtship, with a delay at the end of the reproductive season
only when the male was present behind the barrier. We discuss the seasonal results in terms of L. dalli life history and the potential benefits and costs of changing sex late in the season in the presence or absence of aggressive
reinforcement by the male. Our results identify direct behavioural interactions as an important proximate mechanism in the
social regulation of sex change in L. dalli. 相似文献
868.
Per Angelstam Jean-Michel Roberge Robert Axelsson Marine Elbakidze Karl-Olof Bergman Anders Dahlberg Erik Degerman Sönke Eggers Per-Anders Esseen Joakim Hjältén Therese Johansson Jörg Müller Heidi Paltto Tord Snäll Ihor Soloviy Johan Törnblom 《Ambio》2013,42(2):229-240
Assessing ecological sustainability involves monitoring of indicators and comparison of their states with performance targets that are deemed sustainable. First, a normative model was developed centered on evidence-based knowledge about (a) forest composition, structure, and function at multiple scales, and (b) performance targets derived by quantifying the habitat amount in naturally dynamic forests, and as required for presence of populations of specialized focal species. Second, we compared the Forest Stewardship Council (FSC) certification standards’ ecological indicators from 1998 and 2010 in Sweden to the normative model using a Specific, Measurable, Accurate, Realistic, and Timebound (SMART) indicator approach. Indicator variables and targets for riparian and aquatic ecosystems were clearly under-represented compared to terrestrial ones. FSC’s ecological indicators expanded over time from composition and structure towards function, and from finer to coarser spatial scales. However, SMART indicators were few. Moreover, they poorly reflected quantitative evidence-based knowledge, a consequence of the fact that forest certification mirrors the outcome of a complex social negotiation process. 相似文献
869.
Van Herzele A Dendoncker N Acosta-Michlik L 《Journal of environmental management》2011,92(3):1023-1032
The integration of environmental concerns into agricultural policies - through agri-environment measures (AEM) - has seen a fast development across Europe. This paper conceives AEM as an evolving instrument, a product that takes shape, gets diffused and taken up in, by and through networks of relations. Success then depends on the mobilisation or active participation of all those who may support and develop it. Using the examples of the Flanders' and Walloon regions of Belgium, the paper sets out to examine the mechanisms by which mobilisation for agri-environmental management develops, and by doing so, to gain a better understanding of mobilisation capacity as a concept to be used for evaluating policy implementation in this area. The study follows AEM along the various trajectories of implementation (design, distribution, application). The findings reveal how mobilisation capacity is gradually built-up by the interplay between AEM and the networks it connects to. The case illustrates well how such interactions occur all the way from administration offices to farmers' fields, and that their nature can be very different (e.g., formal and informal, durable and short-lived, expected and unexpected). It is concluded that in evaluating actor-networks, one should look at them in an open and fluid manner, that is, not to privilege any particular configuration or form of attachment over the other, not take intentions and objectives as a starting point but instead address the opportunities for synergies, and be aware that any network built around the instrument may change its content and the way it functions. 相似文献
870.