747 research outputs found

    Promotion of Coalescence in Bicellar Mixtures by an SP-B Fragment

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    Political legitimacy in decisions about experiments in solar radiation management

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    Some types of solar radiation management (SRM) research are ethically problematic because they expose persons, animals, and ecosystems to significant risks. In our earlier work, we argued for ethical norms for SRM research based on norms for biomedical research. Biomedical researchers may not conduct research on persons without their consent, but universal consent is impractical for SRM research. We argue that instead of requiring universal consent, ethical norms for SRM research require only political legitimacy in decision-making about global SRM trials. Using Allen Buchanan & Robert Keohane's model of global political legitimacy, we examine several existing global institutions as possible analogues for a politically legitimate SRM decision-making body

    Motor Carrier Scheduling Practices and Their Influence on Driver Fatigue

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    The primary objective of this report is to develop a better understanding of how the scheduling practices of motor carrier firms affect driver fatigue. The basis of this empirical research is a commercial driver fatigue model that includes driving environment (i.e., regularity of time, trip control, and quality of rest), economic pressures exerted on drivers (from customers, carriers, and the drivers themselves) and company safety practices as key factors in explaining driver fatigue. The model utilizes two measures of fatigue: frequency of close calls due to fatigue and driver perceptions of fatigue as a problem. Crash involvement is used to evaluate general safety performance. Three separate studies were conducted. First, the influence of driving environments alone on fatigue among over-the-road truck drivers was tested through a survey of 502 drivers at five geographically dispersed truck stops. A typology of driving environments was developed and the percent of drivers in each category was determined. It was found that a large number of drivers are in the “high fatigue risk” categories. Regression analysis identified starting the work week tired and longer than expected loading and unloading time as significantly related to both measures of fatigue. Regularity of time, regularity of route, and hours of uninterrupted sleep were each statistically significant factors for one fatigue measure. Next, the complete model was tested on a random sample of 279 drivers at 116 trucking companies and 122 drivers at 66 motor coach companies, which was then stratified on the basis of safety performance (i.e., SAFESTAT ratings). Data for these two studies were generated from surveys of drivers, safety directors, dispatchers, and top management at the sample firms. In the truck company study, starting the workweek tired was the single most significant factor related to fatigue. Other significant fatigue-influencing factors were difficulty in finding a place to rest and shippers’ and receivers’ scheduling requirements (including loading and unloading). Company safety practices that mitigated driver fatigue were carrier assistance with loading and unloading, carrier efforts to minimize nighttime driving, and driver voluntary attendance at corporate safety and training meetings. In the motor coach company study, the most significant factors related to driver fatigue were starting the work week tired, driving tired to make a good income, and pressure on drivers to accept trips. Two safety measures – drivers’ perceptions of their company’s safe drivingculture and policies, or attempts to minimize nighttime driving – mitigated some of the factors that adversely affect driver fatigue

    Association between muscular strength and mortality in men: prospective cohort study

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    Objective: To examine prospectively the association between muscular strength and mortality from all causes, cardiovascular disease, and cancer in men. Design: Prospective cohort study. Setting: Aerobics center longitudinal study. Participants: 8762 men aged 20-80. Main outcome measures: All cause mortality up to 31 December 2003; muscular strength, quantified by combining one repetition maximal measures for leg and bench presses and further categorised as age specific thirds of the combined strength variable; and cardiorespiratory fitness assessed by a maximal exercise test on a treadmill. Results: During an average follow-up of 18.9 years, 503 deaths occurred (145 cardiovascular disease, 199 cancer). Age adjusted death rates per 10,000 person years across incremental thirds of muscular strength were 38.9, 25.9, and 26.6 for all causes; 12.1, 7.6, and 6.6 for cardiovascular disease; and 6.1, 4.9, and 4.2 for cancer (all P Conclusion: Muscular strength is inversely and independently associated with death from all causes and cancer in men, even after adjusting for cardiorespiratory fitness and other potential confounders

    Use of Extinguish Plus™ to Reduce Red Imported Fire Ants and Increase Northern Bobwhite Abundance

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    Populations of northern bobwhite (Colinus virginianus) have been declining throughout Texas since at least the 1970s. The red imported fire ant (RIFA, Solenopsis invicta) was introduced from South America and reached Texas by the 1950s. Previous studies have documented the negative effects of RIFA on northern bobwhite populations through both direct predation and indirect reduction of small invertebrates. In 2013, 2014, and 2015, large areas (1,490 ha in 2013 and 2,380 ha in 2014 and 2015) of the 3,744-ha portion of the Attwater Prairie Chicken National Wildlife Refuge (APCNWR) in Colorado County, Texas, were aerially treated with Extinguish Plus™, a chemical pesticide and reproductive inhibitor that targets ants. Our study took place on APCNWR and our objectives included evaluation of the impacts of RIFA treatment on 1) RIFA abundance, and 2) northern bobwhite nest success and brood survival. We trapped, banded, and radiocollared northern bobwhites in areas treated and not treated with Extinguish Plus from May 2014 through August 2016. We also collected RIFA abundance data using baited Petri dishes on areas treated and nontreated areas during these periods. Treatment reduced RIFA presence on the refuge by 73.4% during 2014 and 2015, but did not reduce RIFA presence during 2016 possibly because of displacement of RIFA colonies due to heavy flooding on the refuge. We detected a difference (χ21 = 11,009, P = 0.0009) in the number of females sighted with and without broods between treated (19.5% F with broods) and nontreated areas (35.7% F with broods). We also found a difference (t12 = 2.51, P = 0.027) in mean number of chicks per brood sighted within treated (4.7) versus nontreated (9.3) areas for 2014 and 2014; but in 2016, we found no difference (t12 = 0.32, P = 0.754) in mean number of chicks per brood sighted within treated (7.7) and nontreated (8.4) areas, which was possibly due to extensive flooding in the nontreated area in April that destroyed most first nests. Our data suggested treatment with Extinguish Plus did not increase northern bobwhite abundance on the APCNWR during the 2014, 2015, and 2016 bobwhite nesting seasons. Our results differ from previous studies, possibly because of time since treatment and differences in environmental factors between treated and nontreated areas such as ecological site, vegetation composition, and predator abundance
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