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1.

Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.

  相似文献   
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Ambio - Muskoxen (Ovibos moschatus) are an integral component of Arctic biodiversity. Given low genetic diversity, their ability to respond to future and rapid Arctic change is unknown, although...  相似文献   
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How species interact modulate their dynamics, their response to environmental change, and ultimately the functioning and stability of entire communities. Work conducted at Zackenberg, Northeast Greenland, has changed our view on how networks of arctic biotic interactions are structured, how they vary in time, and how they are changing with current environmental change: firstly, the high arctic interaction webs are much more complex than previously envisaged, and with a structure mainly dictated by its arthropod component. Secondly, the dynamics of species within these webs reflect changes in environmental conditions. Thirdly, biotic interactions within a trophic level may affect other trophic levels, in some cases ultimately affecting land–atmosphere feedbacks. Finally, differential responses to environmental change may decouple interacting species. These insights form Zackenberg emphasize that the combination of long-term, ecosystem-based monitoring, and targeted research projects offers the most fruitful basis for understanding and predicting the future of arctic ecosystems.  相似文献   
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This paper discusses the extent to which charity-led initiatives can contribute to capacity building for food justice in England. The paper draws on evaluations of two projects run by the charity Garden Organic: the Master Gardener Programme, operating a network of volunteers who mentor households, schools and community groups to support local food growing, and the Sowing New Seeds programme, which engages “Seed Stewards” to work with communities to encourage the growing and cooking of “exotic” crops. Based on qualitative data about peoples’ motivations for participation and the benefits that are experienced, we interpret these projects as examples of capacity building for food justice. We suggest that whilst currently depoliticised, the “quiet” process of reskilling and awareness raising that occurs through shared gardening projects could have transformative potential for people’s relationship with food. Finally, we use our findings to raise critical questions and propose future research about food justice concepts and practices.  相似文献   
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We investigated the global metabolite response to artificial selection for tolerance to stressful conditions such as cold, heat, starvation, and desiccation, and for longevity in Drosophila melanogaster. Our findings were compared to data from other levels of biological organization, including gene expression, physiological traits, and organismal stress tolerance phenotype. Overall, we found that selection for environmental stress tolerance changes the metabolomic 1H NMR fingerprint largely in a similar manner independent of the trait selected for, indicating that experimental evolution led to a general stress selection response at the metabolomic level. Integrative analyses across data sets showed little similarity when general correlations between selection effects at the level of the metabolome and gene expression were compared. This is likely due to the fact that the changes caused by these selection regimes were rather mild and/or that the dominating determinants for gene expression and metabolite levels were different. However, expression of a number of genes was correlated with the metabolite data. Many of the identified genes were general stress response genes that are down-regulated in response to selection for some of the stresses in this study. Overall, the results illustrate that selection markedly alters the metabolite profile and that the coupling between different levels of biological organization indeed is present though not very strong for stress selection at this level. The results highlight the extreme complexity of environmental stress adaptation and the difficulty of extrapolating and interpreting responses across levels of biological organization.  相似文献   
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The fate of glyphosate and its degradation product aminomethylphosphonic acid (AMPA) was studied in soil. Labeled glyphosate was used to be able to distinguish the measured quantities of glyphosate and AMPA from the background values since the soil was sampled in a field where glyphosate had been used formerly. After addition of labeled glyphosate, the disappearance of glyphosate and the formation and disappearance of AMPA were monitored. The resulting curves were fitted according to a new EU guideline. The best fit of the glyphosate degradation data was obtained using a first-order multi compartment (FOMC) model. DT50 values of 9 days (glyphosate) and 32 days (AMPA) indicated relatively rapid degradation. After an aging period of 6 months, the leaching risk of each residue was determined by treating the soil with pure water or a phosphate solution (pH 6), to simulate rain over a non-fertilized or fertilized field, respectively. Significantly larger (p < 0.05) amounts of aged glyphosate and AMPA were extracted from the soil when phosphate solution was used as an extraction agent, compared with pure water. This indicates that the risk of leaching of aged glyphosate and AMPA residues from soil is greater in fertilized soil. The blank soil, to which 252 g glyphosate/ha was applied 21 months before this study, contained 0.81 ng glyphosate/g dry soil and 10.46 ng AMPA/g dry soil at the start of the study. Blank soil samples were used as controls without glyphosate addition. After incubation of the blank soil samples for 6 months, a significantly larger amount of AMPA was extracted from the soil treated with phosphate solution than from that treated with pure water. To determine the degree of uptake of aged glyphosate residues by crops growing in the soil, 14C-labeled glyphosate was applied to soil 6.5 months prior to sowing rape and barley seeds. After 41 days, 0.006 ± 0.002% and 0.005 ± 0.001% of the applied radioactivity was measured in rape and barley, respectively.  相似文献   
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Increasing public concern for the welfare of fish species that human beings use and exploit has highlighted the need for better understanding of the cognitive status of fish and of their ability to experience negative emotions such as pain and fear. Moreover, studying emotion and cognition in fish species broadens our scientific understanding of how emotion and cognition are represented in the central nervous system and what kind of role they play in the organization of behavior. For instance, on a macro neuro-architecture level the brains of fish species look dramatically different from those of mammals, while such a dramatic difference does not (always) occur at the level of emotion- and cognition-related behavior. Here, therefore, we discuss the evidence of emotion and cognition in fish species related to underlying neuro-architecture and the role that emotion and cognition play in the organization of behavior. To do so we use a framework encompassing a number of steps allowing a systematic approach to these issues. Emotion and cognition confer on human and non-human animals the capacity to compliment and/or override immediate reflexes to stimuli and so allow a large degree of flexibility in behavior. Systematic research on behavior that in mammals is indicative of emotion and cognition has been conducted in only a few fish species. The data thus far indicate that in these species brain-behavior relationships are not fundamentally different from those observed in mammals. Furthermore, data from other studies show evidence that behavior patterns related to emotion and cognition vary between fish species as well within fish species, related to sex and life history stage for example. From a welfare perspective, knowledge of such variability will potentially help us to design optimal living conditions for fish species kept by humans.  相似文献   
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