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1.
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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Alkaptonuria (AKU) is a disease caused by a deficient homogentisate 1,2-dioxygenase activity leading to systemic accumulation of homogentisic acid (HGA), that forms a melanin-like polymer that progressively deposits onto connective tissues causing a pigmentation called “ochronosis” and tissue degeneration. The effects of AKU and ochronotic pigment on the biomechanical properties of articular cartilage need further investigation. To this aim, AKU cartilage was studied using thermal (thermogravimetry and differential scanning calorimetry) and rheological analysis. We found that AKU cartilage had a doubled mesopore radius compared to healthy cartilage. Since the mesoporous structure is the main responsible for maintaining a correct hydrostatic pressure and tissue homoeostasis, drastic changes of thermal and rheological parameters were found in AKU. In particular, AKU tissue lost its capability to enhance chondrocytes metabolism (decreased heat capacity) and hence the production of proteoglycans. A drastic increase in stiffness and decrease in dissipative and lubricant role ensued in AKU cartilage. Multiphoton and scanning electron microscopies revealed destruction of cell–matrix microstructure and disruption of the superficial layer. Such observations on AKU specimens were confirmed in HGA-treated healthy cartilage, indicating that HGA is the toxic responsible of morphological and mechanical alterations of cartilage in AKU.  相似文献   
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There are over one million described invertebrate species on Earth, the majority of which are likely to inhabit the highly biodiverse rain forests around the equator. These are some of the most vulnerable ecosystems on Earth due to the pressures of deforestation and climate change with many of their inhabitants at risk of extinction. Invertebrates play a major role in ecosystem functioning from decomposition and nutrient cycling to herbivory and pollination; however, while our understanding of these roles is improving, we are far from being able to predict the consequences of further deforestation, climate change, and biodiversity loss due to the lack of comparative data and the high proportion of species which remain to be discovered. As we move into an era of increased pressure on old-growth habitats and biodiversity, it is imperative that we understand how changes to invertebrate communities, and the extinction of species, affect ecosystems. Innovative and comprehensive methods that approach these issues are needed. Here, we highlight priorities for future tropical terrestrial invertebrate research such as the efficiency of sustainable land management, exploration of innovative methods for better understanding of invertebrate ecology and behavior, and quantifying the role of invertebrates in ecosystem functioning.  相似文献   
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Efforts to restore ponderosa pine ecosystems to open, park‐like conditions that predominated prior to European‐American settlement result in altered stand structure and increased landscape heterogeneity, potentially altering habitat suitability for invertebrates and other forest organisms. We examined the responses of two butterfly species, Colias eurytheme and Neophasia menapia, to microclimatic changes at structural edges created by experimental restoration treatments in northern Arizona. We monitored microclimate, including air temperature, light intensity, and vapor pressure deficit (VPD), on several mornings during butterfly releases. We placed adult butterflies at east‐ and west‐facing edges approximately one half‐hour before dawn to determine their behavioral response to microclimatic differences between east‐ and west‐facing edges. After sunrise, all three microclimatic variables were higher at east‐facing edges, and the difference in microclimate between the two edge orientations increased through early morning. For both species, butterflies placed at east‐facing edges flew earlier than butterflies at west‐facing edges. Colias eurytheme, an open‐habitat species, tended to move toward the treated forest during initial flight, while movements of Neophasia menapia, a forest‐dwelling species, did not differ from random flight. Our results indicate that butterflies respond to microclimatic factors associated with restoration treatments, while responses to structural changes in habitat vary among species, based on habitat and food plant preferences. These changes in forest structure and microclimate may affect the distribution of many mobile invertebrates in forested landscapes undergoing restoration treatments.  相似文献   
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The anticholinergic potencies of R- and S- disopyramide were studied in isolated myenteric plexus longitudinal muscle strip preparations from guinea-pig ileum using two experimental procedures. The first procedure tested the relative potencies of the isomers in inhibiting electrically-stimulated contractions in 6 ileum preparations. A balanced crossover design was employed. The mean concentration of S-disopyramide required to inhibit electrically stimulated contractions by 50% was 4.6 × 10?6 M and was about one-fourth of the concentration of R-disopyramide required to produce the same effect (p < 0.05). The second procedure tested the relative potencies of the isomers as direct antagonists of contractions induced by either histamine or acetylcholine in ileum preparations. Neither isomer antagonized the histamine-induced contractions. For the contractions induced by acetylcholine, the pA2 value, obtained directly from Schild plots, was 6.25 for S- and 5.74 for R- disopyramide. However, the slope of the Schild plot for the S-isomer differed significantly from ?1, suggesting that other mechanisms in addition to direct antagonism of acetylcholine may be involved. Thus, the results of the experiments involving both the antagonism of electrically stimulated contractions and the direct antagonism of acetylcholine-induced contractions indicate (1) that both isomers of disopyramide have anticholinergic properties and (2) that S-disopyramide is about 3–4 fold more potent as an anticholinergic agent.  相似文献   
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REACH and LCA—methodological approaches and challenges   总被引:1,自引:0,他引:1  

Purpose  

This paper discusses issues associated with the research question: What are the similarities and differences between the REACH and life cycle assessment (LCA) approaches, and how can synergies between these two approaches be exploited to achieve environmental improvements in a holistic perspective?  相似文献   
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Thylakoid membranes were subjected to photoinhibitory illumination. The use of oxygen-consuming enzymes to obtain strictly anaerobic conditions showed that while the absence of oxygen is a prerequisite for the formation of a reversibly photoinhibited state, the presence of oxygen is required for the recovery in the dark. The formation of the reversibly photoinhibited state did not protect the thylakoid membranes against irreversible damage. The effects of both bicarbonate and formate were found to be qualitatively different for photoinhibition under strictly anaerobic conditions compared to the effects observed under normal aerobic photoinhibition. It is suggested that there are two different mechanisms of photoinhibition, occurring to different extent under aerobic and anaerobic conditions, respectively, involving QA in both cases, but the QB-site in the former only.Abbreviations chl chlorophyll - PpBQ phenyl-p-benzoquinone - PS 2 Photosystem 2 - QA and QB primary and secondary quinone acceptors of Photosystem 2  相似文献   
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