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131.
Scientists need to find innovative ways to communicate their findings with restoration practitioners in an era of global change. Apps are a promising bridge between restoration science and practice because they apply broad scientific concepts to specific situations. For example, habitat connectivity promotes ecological function, but practitioners lack ways to incorporate connectivity into decision‐making. We created an app where users calculate how habitat restoration or loss affects connectivity. By providing our app as an example and discussing the benefits and challenges in creating apps for practitioners, we encourage other restoration ecologists to similarly create apps that bridge science with practice.  相似文献   
132.
This is the first X-ray crystal structure of the monomeric form of sulfite reductase (SiR) flavoprotein (SiRFP-60) that shows the relationship between its major domains in an extended position not seen before in any homologous diflavin reductases. Small angle neutron scattering confirms this novel domain orientation also occurs in solution. Activity measurements of SiR and SiRFP variants allow us to propose a novel mechanism for electron transfer from the SiRFP reductase subunit to its oxidase metalloenzyme partner that, together, make up the SiR holoenzyme. Specifically, we propose that SiR performs its 6-electron reduction via intramolecular or intermolecular electron transfer. Our model explains both the significance of the stoichiometric mismatch between reductase and oxidase subunits in the holoenzyme and how SiR can handle such a large volume electron reduction reaction that is at the heart of the sulfur bio-geo cycle.  相似文献   
133.
The purpose of this research was to conduct reconstructions of concussive and non-concussive impacts in ice hockey to determine the biomechanics and thresholds of concussive injury in ice hockey. Videos of concussive and non-concussive impacts in an elite professional ice hockey league in North America were reconstructed using physical and finite element model methods. Eighty concussive and 45 non-concussive events were studied. Logistic regressions indicate significant thresholds for concussion for linear/rotational acceleration and CSDM10%. Impacts in ice hockey were mostly long duration events, longer than 15?ms. These results have significant implications for helmet standards and development to prevent concussion.  相似文献   
134.
Climate change is altering the conditions for tree recruitment, growth, and survival, and impacting forest community composition. Across southeast Alaska, USA, and British Columbia, Canada, Callitropsis nootkatensis (Alaska yellow‐cedar) is experiencing extensive climate change‐induced canopy mortality due to fine‐root death during soil freezing events following warmer winters and the loss of insulating snowpack. Here, we examine the effects of ongoing, climate‐driven canopy mortality on forest community composition and identify potential shifts in stand trajectories due to the loss of a single canopy species. We sampled canopy and regenerating forest communities across the extent of C. nootkatensis decline in southeast Alaska to quantify the effects of climate, community, and stand‐level drivers on C. nootkatensis canopy mortality and regeneration as well as postdecline regenerating community composition. Across the plot network, C. nootkatensis exhibited significantly higher mortality than co‐occurring conifers across all size classes and locations. Regenerating community composition was highly variable but closely related to the severity of C. nootkatensis mortality. Callitropsis nootkatensis canopy mortality was correlated with winter temperatures and precipitation as well as local soil drainage, with regenerating community composition and C. nootkatensis regeneration abundances best explained by available seed source. In areas of high C. nootkatensis mortality, C. nootkatensis regeneration was low and replaced by Tsuga. Our study suggests that climate‐induced forest mortality is driving alternate successional pathways in forests where C. nootkatensis was once a major component. These pathways are likely to lead to long‐term shifts in forest community composition and stand dynamics. Our analysis fills a critical knowledge gap on forest ecosystem response and rearrangement following the climate‐driven decline of a single species, providing new insight into stand dynamics in a changing climate. As tree species across the globe are increasingly stressed by climate change‐induced alteration of suitable habitat, identifying the autecological factors contributing to successful regeneration, or lack thereof, will provide key insight into forest resilience and persistence on the landscape.  相似文献   
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In this study we investigate conformational changes in Loop V-VI of visual arrestin during binding to light-activated, phosphorylated rhodopsin (Rho*-P) using a combination of site-specific cysteine mutagenesis and intramolecular fluorescence quenching. Introduction of cysteines at positions in the N-domain at residues predicted to be in close proximity to Ile-72 in Loop V-VI of arrestin (i.e. Glu-148 and Lys-298) appear to form an intramolecular disulfide bond with I72C, significantly diminishing the binding of arrestin to Rho*-P. Using a fluorescence approach, we show that the steady-state emission from a monobromobimane fluorophore in Loop V-VI is quenched by tryptophan residues placed at 148 or 298. This quenching is relieved upon binding of arrestin to Rho*-P. These results suggest that arrestin Loop V-VI moves during binding to Rho*-P and that conformational flexibility of this loop is essential for arrestin to adopt a high affinity binding state.  相似文献   
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138.
Objective: To evaluate the effect of a high‐protein diet on anthropometry, body composition, subjective appetite, and mood sensations in overweight and obese children attending a residential weight‐loss camp. Research Methods and Procedures: Children (120; BMI, 33.1 ± 5.5 kg/m2; age, 14.2 ± 1.9 years) were randomly assigned to either a standard or high‐protein diet group (15% vs. 22.5% protein, respectively). All children were assessed at baseline and at the end of the camp for anthropometry, body composition, blood pressure, biochemical variables (n = 27), and subjective appetite and mood sensations (n = 50). Results: Attendance at the weight‐loss camp resulted in significant improvements in most measures. Campers lost 5.5 ± 2.9 kg in body weight (p < 0.001) and 3.8 ± 5.4 kg in fat mass (p < 0.001) and reduced their BMI standard deviation score by 0.27 ± 0.1 (p < 0.001) and their waist circumference by 6.6 ± 2.8 cm (p < 0.001). Subjective sensations of hunger increased significantly over the camp duration, but no other changes in appetite or mood were observed. There were no significant differences between the two diets on any physical or subjective measures. Discussion: Weight‐loss camps are effective in assisting children to lose weight and improve on a range of health outcomes, independently of the protein content of the diet. The implications of an increase in hunger associated with weight loss needs to be considered. Further work is warranted to investigate whether higher levels of dietary protein are feasible or effective in longer‐term weight‐loss interventions of this type.  相似文献   
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140.
The anthrax attacks of 2001 demonstrated that bioterrorism poses a significant threat to U.S. national security. This threat is increasing as a result of the rapid expansion in scale and technical capabilities of the global biotechnology industry, which is broadening the availability of materials, technologies, and expertise needed to produce a biological weapon and is lowering the barriers to biological weapons terrorism and proliferation. At the same time, there has been a rise of sophisticated yet loosely networked transnational terrorist groups that have shown an interest in bioterrorism. The United States must confront this convergence. Although the U.S. government pursues many different biodefense programs to bolster its ability to detect and respond to a bioterrorist attack, these efforts must be augmented with preventive measures to meet today's international challenges. U.S. Homeland Security Presidential Directive 10 of April 2004 defines "Prevention and Protection" as one of the four essential pillars of the U.S. response to the bioterrorist threat. However, while bioscience and policy experts have proposed a variety of preventive initiatives, the creation of such programs has been slow and limited. Global biological materials management, which would focus on identifying and protecting those biological materials at the greatest risk of being used maliciously, is one potential solution. Such an approach would augment current U.S. biodefense efforts, provide the international community an effective means of mitigating the global threat of bioterrorism, and strengthen the international community's battle against emerging infectious disease.  相似文献   
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