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61.
Life-history theory predicts that individuals should increase their reproductive effort when the fitness return from reproduction is high. Females mated with high-quality males are therefore expected to have higher investment than females mated with low-quality males, which could bias estimates of paternal effects. Investigating the traits females use in their allocation decisions and the aspects of reproduction that are altered is essential for understanding how sexual selection is affected. We studied the potential for differential female allocation in a captive population of a precocial bird, the Chinese quail, Coturnix chinensis. Females paired with males with large sexual ornaments laid larger, but not more, eggs than females paired with males with small sexual ornaments. Furthermore, female egg mass was also significantly positively affected by male testis size, probably via some unknown effect of testis size on male phenotype. Testis size and ornament size were not correlated. Thus, both primary and secondary male sexual traits could be important components of female allocation decisions. Experimental manipulation of hormone levels during embryonic development showed that both male and female traits influencing female egg size were sensitive to early hormone exposure. Differences in prenatal hormone exposure as a result of maternal steroid allocation to eggs may explain some of the variation in reproductive success among individuals, with important implications for non-genetic transgenerational effects in sexual selection.Communicated by C. Brown  相似文献   
62.
A general model for annual runoff rate predictions of total copper from naturally patinated copper on buildings at specific urban or rural sites of low chloride influence has been deduced from laboratory and field data. All parameters within the model have a physical meaning and include the average annual rain acidity (pH), the annual rain quantity and the geometry of a building in terms of surface inclination. In 70% of all reported annual runoff rates, the predicted values are within 30% from the observed values. The individual and interactive effect of rain composition in terms of pH, sulfate, chloride and nitrate concentration was investigated in immersion experiments in artificial rain water representative of urban and rural sites of Europe. The results show pH to have a dominating effect on patina dissolution, nitrate to have a small inhibiting effect, whereas no significant effect was seen for chloride and sulfate. In case pH data are not available, a model has been statistically deduced from field data by considering SO2 as influencing parameter, rather than pH. The predictability with the SO2 model is not as good as with the pH model i.e. the pH model should preferentially be used since it is a better predictor and all parameters within the model can be physically explained.  相似文献   
63.
We summarize direct and indirect effects on fitness components of animal color pattern and present a synthesis of theories concerning the ecological and evolutionary dynamics of chromatic multiple niche polymorphisms. Previous endeavors have aimed primarily at identifying conditions that promote the evolution and maintenance of polymorphisms. We consider in a conceptual model also the reciprocal influence of color polymorphism on population processes and propose that polymorphism entails selective advantages that may promote the ecological success of polymorphic species. The model begins with an evolutionary branching event from mono- to polymorphic condition that, under the influence of correlational selection, is predicted to promote the evolution of physical integration of coloration and other traits (cf. multi-trait coevolution and complex phenotypes). We propose that the coexistence within a population of alternative ecomorphs with coadapted gene complexes promotes utilization of diverse environmental resources, population stability and persistence, colonization success, and range expansions, and enhances the evolutionary potential and speciation. Conversely, we predict polymorphic populations to be less vulnerable to environmental change and at lower risk of range contractions and extinctions compared with monomorphic populations. We offer brief suggestions as to how these falsifiable predictions may be tested.  相似文献   
64.
Atmospheric polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that represent a risk not only to humans, but to all living organisms. High-molecular weight PAHs are more toxic than lighter relatives, and also have a higher tendency to bind onto air particles (i.e., particle matter, PM). PM is a major constituent of air pollution. Adequate assessment of the biological impact of PM requires the analysis, not only of the effects on human health, but also on the environment. Since the aquatic systems work as a natural sink to these air pollutants, assessing the effects of particle-bound PAHs on aquatic organisms may further characterize its potential aquatic toxicity, also providing simple and low-cost alternative assays to investigate PM biological effects in vivo. We review the current scientific literature, addressing the atmospheric PAHs fate, transformation and deposition, pertinent particle-bound PAHs toxicity data, and the potential aquatic toxic burden. Conceptual and experimental procedures that could improve future investigations and risk assessments are also considered.  相似文献   
65.
As the need to address climate change is ever more urgent, many have emphasised the importance of community-level responses. The Transition movement has advanced community-based action to increase resilience for over a decade and has expanded significantly. Thus, it is a critical setting for examining community engagement towards climate change in practice. Our study is based on 39 interviews with facilitators of Transition initiatives in Portugal, coupled with observational data, and is guided by two main research questions: how do Transition initiatives promote community engagement at the local level? What are the factors constraining or facilitating community engagement within Portuguese Transition initiatives? We identify several aspects of Transition’s constructions of community resilience and engagement that indicate ambivalence towards, or avoidance of, certain issues. They relate do agency, structure, power and inclusion, as well as to the modes of engagement and the communication practices of Transition initiatives. We argue that strategies for community engagement should be specific to social contexts rather than internationally uniform and be based on participatory approaches. Drawing on an extensive empirical analysis, the article contributes to theory building on the Transition movement beyond the Anglo-Saxon context and to the wider field of community-based environment initiatives.  相似文献   
66.
Possible effects of climate change on air quality are studied for two urban sites in the UK, London and Glasgow. Hourly meteorological data were obtained from climate simulations for two periods representing the current climate and a plausible late 21st century climate. Of the meteorological quantities relevant to air quality, significant changes were found in temperature, specific humidity, wind speed, wind direction, cloud cover, solar radiation, surface sensible heat flux and precipitation. Using these data, dispersion estimates were made for a variety of single sources and some significant changes in environmental impact were found in the future climate. In addition, estimates for future background concentrations of NOx, NO2, ozone and PM10 upwind of London and Glasgow were made using the meteorological data in a statistical model. These showed falls in NOx and increases in ozone for London, while a fall in NO2 was the largest percentage change for Glasgow. Other changes were small. With these background estimates, annual-average concentrations of NOx, NO2, ozone and PM10 were estimated within the two urban areas. For London, results averaged over a number of sites showed a fall in NOx and a rise in ozone, but only small changes in NO2 and PM10. For Glasgow, the changes in all four chemical species were small. Large-scale background ozone values from a global chemical transport model are also presented. These show a decrease in background ozone due to climate change. To assess the net impact of both large scale and local processes will require models which treat all relevant scales.  相似文献   
67.
Biodiversity conservation work can be challenging but rewarding, and both aspects have potential consequences for conservationists’ mental health. Yet, little is known about patterns of mental health among conservationists and its associated workplace protective and risk factors. A better understanding might help improve working conditions, supporting conservationists’ job satisfaction, productivity, and engagement, while reducing costs from staff turnover, absenteeism, and presenteeism. We surveyed 2311 conservation professionals working in 122 countries through an internet survey shared via mailing lists, social media, and other channels. We asked them about experiences of psychological distress, working conditions, and personal characteristics. Over half were from and worked in Europe and North America, and most had a university-level education, were in desk-based academic and practitioner roles, and responded in English. Heavy workload, job demands, and organizational instability were linked to higher distress, but job stability and satisfaction with one's contributions to conservation were associated with lower distress. Respondents with low dispositional and conservation-specific optimism, poor physical health, and limited social support, women, and early-career professionals were most at risk of distress in our sample. Our results flag important risk factors that employers could consider, although further research is needed among groups underrepresented in our sample. Drawing on evidence-based occupational health interventions, we suggest measures that could promote better working conditions and thus may improve conservationists’ mental health and abilities to protect nature.  相似文献   
68.
Wind power is expanding globally. Simultaneously, a growing number of conflicts against large-scale wind farms are emerging in multiple locations around the world. As these processes occur, new questions arise on how electricity from wind is being generated, how such energy is flowing within societies, and how these production-flows are being shaped by specific power structures. The present paper explores the expanding geography of wind energy conflicts by analyzing 20 case studies from across the Americas, Africa, Asia and Europe. Based on the Environmental Justice Atlas database, it reflects on how land pressures and patterns of uneven development emerge as two features of the current expansion of wind farms. Following a relational analysis, these patterns are examined to interpret the plural instances of opposition emerging throughout the rural spaces of the world. The article argues that previously unexplored forms of collective action are expanding the scope and content of the “wind energy debate”. In addition to the claims of “landscape” and “wildlife protection” addressed by the existing literature, this study sheds light on the rural/peripheral contexts where opposition emerges through the defense of indigenous territories, local livelihoods and communal development projects. The study contends that these “emerging storylines” embrace an environmental justice perspective when challenging the socially unequal and geographically uneven patterns reproduced by the ecological modernization paradigm. From this lens, cases of local opposition are not interpreted as selfish forces blocking a low-carbon transition, but instead, are understood as political instances that enable a wider discussion about the ways such transition should take place.  相似文献   
69.
The Bormida River Basin, located in the northwestern region of Italy, has been strongly contaminated by the ACNA chemical factory. This factory was in operation from 1892 to 1998, and contamination from the factory has had deleterious consequences on the water quality, agriculture, natural ecosystems and human health. Attempts have been made to remediate the site. The aims of this study were to use high-resolution satellite images combined with a classical remote sensing methodology to monitor vegetation conditions along the Bormida River, both upstream and downstream of the ACNA chemical factory site, and to compare the results obtained at different times before and after the remediation process. The trends of the Normalised Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) along the riverbanks are used to assess the effect of water pollution on vegetation. NDVI and EVI values show that the contamination produced by the ACNA factory had less severe effects in the year 2007, when most of the remediation activities were concluded, than in 2006 and 2003. In 2007, the contamination effects were noticeable up to 6 km downstream of the factory, whereas in 2003 and 2006 the influence range was up to about 12 km downstream of the factory. The results of this study show the effectiveness of remediation activities that have been taking place in this area. In addition, the comparison between NDVI and EVI shows that the EVI is more suitable to characterise the vegetation health and can be considered an additional tool to assess vegetation health and to monitor restoration activities.  相似文献   
70.
Extensive research has been done on the 'high politics' of negotiations of international environmental agreements. However, little attention has been paid to the effectiveness of their implementation after coming into force. Effectiveness cannot be easily measured, since different stakeholders use different criteria as the basis of their opinion. The purpose of this study is to investigate discourses on the effectiveness of an international environmental regime. The regime chosen is the Mediterranean Action Plan (MAP) - and its legal framework, the Barcelona Convention - which was established in 1975 under the aegis of the United Nations Environment Programme (UNEP). Q methodology was used to reveal discourses on the effectiveness of UNEP/MAP. After collecting relevant literature and identifying the stakeholders, 25 in-depth interviews were conducted. The stakeholders were from the Secretariat of the Convention, academia, NGO workers, and others that studied or knew the subject well. From these interviews 294 statements were extracted, from which 44 were finally selected to be used in the Q study. The interviewees were approached for the second time to complete the Q sorts. This study revealed four distinct discourses concerning the effectiveness of international environmental regimes. It concludes that there is no one 'right' way of defining effectiveness and that no approach can provide more than a partial evaluation of the overall effectiveness of a regime.  相似文献   
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