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1.
Tom P. Moorhouse Cecilia A. L. Dahlsj? Sandra E. Baker Neil C. D'Cruze David W. Macdonald 《PloS one》2015,10(10)
Tourism accounts for 9% of global GDP and comprises 1.1 billion tourist arrivals per annum. Visits to wildlife tourist attractions (WTAs) may account for 20–40% of global tourism, but no studies have audited the diversity of WTAs and their impacts on the conservation status and welfare of subject animals. We scored these impacts for 24 types of WTA, visited by 3.6–6 million tourists per year, and compared our scores to tourists’ feedback on TripAdvisor. Six WTA types (impacting 1,500–13,000 individual animals) had net positive conservation/welfare impacts, but 14 (120,000–340,000 individuals) had negative conservation impacts and 18 (230,000–550,000 individuals) had negative welfare impacts. Despite these figures only 7.8% of all tourist feedback on these WTAs was negative due to conservation/welfare concerns. We demonstrate that WTAs have substantial negative effects that are unrecognised by the majority of tourists, suggesting an urgent need for tourist education and regulation of WTAs worldwide. 相似文献
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A nonplanar distortion of the heme ofc-type cytochromes is conserved in the proteins isolated from diverse species based upon a comprehensive analysis of available highresolution X-ray crystal structures. This distortion is induced through the cysteine thioether linkages between the porphyrin pyrrole groups and the polypeptide and results in an asymmetric pyrrole distortion. This asymmetry in the heme distortion is also conserved. For other heme proteins which lack these covalent bonds, nearly planar porphyrins are observed. Resonance Raman evidence indicates that nonplanar distortion of porphyrins containing metals, like iron, with large core sizes (?2.00 Å) is energetically unfavorable and can occur only in the presence of significant environmental perturbations. Further, energy minimization and dynamics calculations on the ferric form of yeast iso-1-cytochromec, starting from the crystallographic coordinates and using a molecular mechanics force field which accurately reproduces nonplanar distortions in metalloporphyrins, suggest that this distortion is indeed maintained by the protein tertiary structure. It is proposed that this protein-linked heme distortion modulates electron transfer function through modification of redox potentials of the porphyrin ring and the protein binding properties ofc-type cytochromes. 相似文献
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Abstract Competition experiments revealed that adenine and guanine were transported by a purine permease in both Candida glabrata 4 and a C. glabrata 4 cytosine permease negative mutant. The C. glabrata 4 cytosine permease negative mutant was isolated using 5-fluorocytosine selection. This mutant no longer transported cytosine, but transported adenine and guanine. A transport system for hypoxanthine was not detected. Hence, in addition to the cytosine permease, a purine permease exists in C. glabrata . This differs from the purine cytosine permeases in Saccharomyces cereuisiae and Candida albicans which transport adenine, cytosine, guanine and hypoxanthine. 相似文献
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Angelica Mendoza Beltran Brian Cox Chris Mutel Detlef P. van Vuuren David Font Vivanco Sebastiaan Deetman Oreane Y. Edelenbosch Jeroen Guinée Arnold Tukker 《Journal of Industrial Ecology》2020,24(1):64-79
Prospective life cycle assessment (LCA) needs to deal with the large epistemological uncertainty about the future to support more robust future environmental impact assessments of technologies. This study proposes a novel approach that systematically changes the background processes in a prospective LCA based on scenarios of an integrated assessment model (IAM), the IMAGE model. Consistent worldwide scenarios from IMAGE are evaluated in the life cycle inventory using ecoinvent v3.3. To test the approach, only the electricity sector was changed in a prospective LCA of an internal combustion engine vehicle (ICEV) and an electric vehicle (EV) using six baseline and mitigation climate scenarios until 2050. This case study shows that changes in the electricity background can be very important for the environmental impacts of EV. Also, the approach demonstrates that the relative environmental performance of EV and ICEV over time is more complex and multifaceted than previously assumed. Uncertainty due to future developments manifests in different impacts depending on the product (EV or ICEV), the impact category, and the scenario and year considered. More robust prospective LCAs can be achieved, particularly for emerging technologies, by expanding this approach to other economic sectors beyond electricity background changes and mobility applications as well as by including uncertainty and changes in foreground parameters. A more systematic and structured composition of future inventory databases driven by IAM scenarios helps to acknowledge epistemological uncertainty and to increase the temporal consistency of foreground and background systems in LCAs of emerging technologies. 相似文献