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排序方式: 共有55条查询结果,搜索用时 31 毫秒
31.
Environmental Science and Pollution Research - Non-small cell lung cancer (NSCLC) is reported to have a high incidence rate and is one of the most prevalent types of cancer contributing towards 85%...  相似文献   
32.
This paper focuses on the importance of rainwater harvesting to mitigate the scarcity of water in the semi-arid region of Brazil. It is a case study about the Million Cisterns Project, an initiative developed by NGOs with the support of Brazilian Federal Government Institutions and international funding organizations. The project is innovative in a series of ways when compared to mitigation measures previously implemented by the government. Instead of focussing on short-term, top-down, palliative measures based on the construction of dams and wells, it focuses on low cost, bottom-up, long-term measures and, most importantly, it involves an educational component. Thus, the provision of water is closely related to the empowerment of the most destitute population and this leads to the sustainability of the actions. The case study serves to illustrate the relevance of the partnership between grassroots organizations and governmental institutions in the context of mitigation.  相似文献   
33.
Objective: Recent field data analyses have shown that the safety advantages of rear seats relative to the front seats have decreased in newer vehicles. Separately, the risks of certain injuries have been found to be higher for obese occupants. The objective of this study is to investigate the effects of advanced belt features on the protection of rear-seat occupants with a range of body mass index (BMI) in frontal crashes.

Methods: Whole-body finite element human models with 4 BMI levels (25, 30, 35, and 40 kg/m2) developed previously were used in this study. A total of 52 frontal crash simulations were conducted, including 4 simulations with a standard rear-seat, 3-point belt and 48 simulations with advanced belt features. The parameters varied in the simulations included BMI, load limit, anchor pretensioner, and lap belt routing relative to the pelvis. The injury measurements analyzed in this study included head and hip excursions, normalized chest deflection, and torso angle (defined as the angle between the hip–shoulder line and the vertical direction). Analyses of covariance were used to test the significance (P <.05) of the results.

Results: Higher BMI was associated with greater head and hip excursions and larger normalized chest deflection. Higher belt routing increased the hip excursion and torso angle, which indicates a higher submarining risk, whereas the anchor pretensioner reduced hip excursion and torso angle. Lower load limits decreased the normalized chest deflection but increased the head excursion. Normalized chest deflection had a positive correlation with maximum torso angle. Occupants with higher BMI have to use higher load limits to reach head excursions similar to those in lower BMI occupants.

Discussion and Conclusion: The simulation results suggest that optimizing load limiter and adding pretensioner(s) can reduce injury risks associated with obesity, but conflicting effects on head and chest injuries were observed. This study demonstrated the feasibility and importance of using human models to investigate protection for occupants with various BMI levels. A seat belt system capable of adapting to occupant size and body shape will improve protection for obese occupants in rear seats.  相似文献   
34.
35.
Poultry litter applications to land have been based on crop N requirements, resulting in application of P in excess of plant requirements, which may cause degradation of water quality in the Chesapeake Bay watershed. The effect of litter source (the Delmarva Peninsula and Moorefield, West Virginia) and composting of poultry litter on N mineralization and availability of P in two soil types (sandy loam and silt loam) was determined in a controlled environment for 120 d. Nitrogen mineralization (percent total organic N converted to inorganic nitrogen) rates were higher for fresh litter (range of 42 to 64%) than composted litter (range of 1 to 9%). The N mineralization rate of fresh litter from the Delmarva Peninsula was consistently lower than the fresh litter from Moorefield, WV. The N mineralization rate of composted litter from either source was not significantly different for each soil type (7 to 9% in sandy loam and 1 to 5% in silt loam) even though composting conditions were completely different at the two composting facilities. Litter source had a large effect on N mineralization rates of fresh but not composted poultry litter. Composting yielded a more predictable and reliable source of mineralizable N than fresh litter. Water-extractable phosphorus (WEP) was similar in soils amended with composted litter from WV and fresh litter from both sources (approximately 10 to 25 and 2 to 14 mg P kg(-1) for sandy loam and silt loam, respectively). Mehlich 1-extractable phosphorus (MEP) was similar in soils amended with WV fresh litter and composted litter from both sources (approximately 100 to 140 and 60 to 90 mg P kg(-1) for sandy loam and silt loam, respectively). These results suggest that the composting process did not consistently reduce WEP and MEP, and P can be as available in composted poultry litter as in fresh poultry litter.  相似文献   
36.
This paper presents and compares case studies of three Flexible Manufacturing Systems (FMSs). Interviews, observation and questionnaire data from two installations are compared to data presented in previous studies of a third installation. Whereas the previous research found that FMS workers suffered from a lack of autonomy and control, this does not characterize work on the two new installations. While in one of the new cases, the difference may have been due to its semi-autonomous team organization, the other new installation was organized along rather conventional lines. Despite its conventional organization, workers in this latter FMS expressed high levels of satisfaction and motivation and their system operated at a very high level of efficiency. This result suggests that future research might fruitfully reconsider whether the relevant factor of satisfaction and motivation is autonomy or efficacy.  相似文献   
37.
Yenni G  Adler PB  Ernest SK 《Ecology》2012,93(3):456-461
Theory has recognized a combination of niche and neutral processes each contributing, with varying importance, to species coexistence. However, long-term persistence of rare species has been difficult to produce in trait-based models of coexistence that incorporate stochastic dynamics, raising questions about how rare species persist despite such variability. Following recent evidence that rare species may experience significantly different population dynamics than dominant species, we use a plant community model to simulate the effect of disproportionately strong negative frequency dependence on the long-term persistence of the rare species in a simulated community. This strong self-limitation produces long persistence times for the rare competitors, which otherwise succumb quickly to stochastic extinction. The results suggest that the mechanism causing species to be rare in this case is the same mechanism allowing those species to persist.  相似文献   
38.
Theis N  Adler LS 《Ecology》2012,93(2):430-435
Many organisms face challenges in avoiding predation while searching for mates. For plants, emitting floral fragrances to advertise reproductive structures could increase the attraction of detrimental insects along with pollinators. Very few studies have experimentally evaluated the costs and benefits of fragrance emission with explicit consideration of how plant fitness is affected by both pollinators and florivores. To determine the reproductive consequences of increasing the apparency of reproductive parts, we manipulated fragrance, pollination, and florivores in the wild Texas gourd, Cucurbita pepo var. texana. With enhanced fragrance we found an increase in the attraction of florivores, rather than pollinators, and a decrease in seed production. This study is the first to demonstrate that enhanced floral fragrance can increase the attraction of detrimental florivores and decrease plant reproduction, suggesting that florivory as well as pollination has shaped the evolution of floral scent.  相似文献   
39.
Barber NA  Adler LS  Theis N  Hazzard RV  Kiers ET 《Ecology》2012,93(7):1560-1570
Herbivores affect plants through direct effects, such as tissue damage, and through indirect effects that alter species interactions. Interactions may be positive or negative, so indirect effects have the potential to enhance or lessen the net impacts of herbivores. Despite the ubiquity of these interactions, the indirect pathways are considerably less understood than the direct effects of herbivores, and multiple indirect pathways are rarely studied simultaneously. We placed herbivore effects in a comprehensive community context by studying how herbivory influences plant interactions with antagonists and mutualists both aboveground and belowground. We manipulated early-season aboveground herbivore damage to Cucumis sativus (cucumber, Cucurbitaceae) and measured interactions with subsequent aboveground herbivores, root-feeding herbivores, pollinators, and arbuscular mycorrhizal fungi (AMF). We quantified plant growth and reproduction and used an enhanced pollination treatment to determine if plants were pollen limited. Increased herbivory reduced interactions with both antagonists and mutualists. Plants with high levels of early herbivory were significantly less likely to suffer leaf damage later in the summer and tended to be less attacked by root herbivores. Herbivory also reduced pollinator visitation, likely due to fewer and smaller flowers, and reduced AMF colonization. The net effect of herbivory on plant growth and reproduction was strongly negative, but lower fruit and seed production were not due to reduced pollinator visits, because reproduction was not pollen limited. Although herbivores influenced interactions between plants and other organisms, these effects appear to be weaker than the direct negative effects of early-season tissue loss.  相似文献   
40.
The proactive displacement by public authorities of populations from areas perceived to be exposed to a high risk of disaster presents complex human rights challenges. Provided that no ulterior motive is at play, the use of compulsory evacuations and relocations as policy responses to such risk is mandated by the duty to protect the right to life. However, proactive displacement in the interest of saving lives can be problematic as such measures can lead to the limitation of other human rights, resulting in an intricate assessment of whether compulsory evacuation or permanent relocation is proportional in any given circumstance. Such an analysis demands critical attention by public authorities to the perception of the disaster risk in question and problematises claims to objectivity of official risk assessments. Furthermore, it poses the question as to whether measures designed to address the disaster risk in question that are less intrusive than relocation may be available to public authorities.  相似文献   
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