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91.
Zheng Li Andreas Sjodin Erin N. Porter Donald G. Patterson Larry L. Needham Sangil Lee Armistead G. Russell James A. Mulholland 《Atmospheric environment (Oxford, England : 1994)》2009,43(5):1043-1050
Twenty-four hour PM2.5 samples from a rural site, an urban site, and a suburban site (next to a major highway) in the metropolitan Atlanta area in December 2003 and June 2004 were analyzed for 19 polycyclic aromatic hydrocarbons (PAH). Extraction of the air samples was conducted using an accelerated solvent extraction method followed by isotope dilution gas chromatography/mass spectrometry determination. Distinct seasonal variations were observed in total PAH concentration (i.e. significantly higher concentrations in December than in June). Mean concentrations for total particulate PAHs in December were 3.16, 4.13, and 3.40 ng m?3 for the urban, suburban and rural sites, respectively, compared with 0.60, 0.74, and 0.24 ng m?3 in June. Overall, the suburban site, which is impacted by a nearby major highway, had higher PAH concentration than did the urban site. Total PAH concentrations were found to be well correlated with PM2.5, organic carbon (OC), and elemental carbon (EC) in both months (r2 = 0.36–0.78, p < 0.05), although the slopes from the two months were different. PAHs represented on average 0.006% of total PM2.5 mass and 0.017% of OC in June, compared with 0.033% of total PM2.5 and 0.14% of OC in December. Total PAH concentrations were also correlated with potassium ion (r2 = 0.39, p = 0.014) in December, but not in June, suggesting that in winter biomass burning can potentially be an important source for particulate PAH. Retene was found at a higher median air concentration at the rural site than at the urban and suburban sites—unlike the rest of the PAHs, which were found at lower levels at the rural site. Retene also had a larger seasonal difference and had the weakest correlation with the rest of the PAHs measured, suggesting that retene, in particular, might be associated with biomass burning. 相似文献
92.
Effects of urbanization on the population structure of freshwater turtles across the United States
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David R. Bowne Bradley J. Cosentino Laurel J. Anderson Christopher P. Bloch Sandra Cooke Patrick W. Crumrine Jason Dallas Alexandra Doran Jerald J. Dosch Daniel L. Druckenbrod Richard D. Durtsche Danielle Garneau Kristen S. Genet Todd S. Fredericksen Peter A. Kish Mary Beth Kolozsvary Frank T. Kuserk Erin S. Lindquist Carol Mankiewicz James G. March Timothy J. Muir K. Greg Murray Madeline N. Santulli Frank J. Sicignano Peter D. Smallwood Rebecca A. Urban Kathy Winnett‐Murray Craig R. Zimmermann 《Conservation biology》2018,32(5):1150-1161
Landscape‐scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will negatively correlate with landscape urbanization. As a collaborative effort of the Ecological Research as Education Network (EREN), we sampled freshwater turtle populations in 11 states across the central and eastern United States. Contrary to expectations, we found a significant positive relationship between proportions of mature female painted turtles (Chrysemys picta) and urbanization. We did not detect a relationship between urbanization and proportions of immature turtles. Urbanization may alter the thermal environment of nesting sites such that more females are produced as urbanization increases. Our approach of creating a collaborative network of scientists and students at undergraduate institutions proved valuable in terms of testing our hypothesis over a large spatial scale while also allowing students to gain hands‐on experience in conservation science. 相似文献
93.
This study explored mechanisms underlying employees' behaviors targeted at preventing workplace physical violence and verbal aggression. Poor psychological violence‐prevention climate perceptions and previous exposure to violence and aggression represent stressors that were associated with increased strains and reduced motivation. Strains and motivation, in turn, were related to prevention behaviors. We collected data from employee and coworker dyads, and structural equation modeling results supported that clear organizational policies, prompt management responses to assaults, and putting safety as a priority contributed positively to prevention behaviors through reduced strains and increased motivation. On the other hand, prior experiences of being attacked were related to more strains and lower motivation, which were related to lower prevention compliance. Our results inform future interventions for violence prevention. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
94.
The Journal of Safety Research has partnered with the Injury Center at the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, USA, to briefly report on some of the latest findings in the research community. This report is the sixth in a series of CDC articles. This conference on Hip Protector Use was held at Boston University in June, 2004 under the sponsorship of the Injury Center. Hip fractures from falls are a major threat to the health and well-being of older adults. One approach to hip fracture prevention is the use of hip protectors (HPs), soft padding or hard shells embedded within specially designed underwear. This conference brought together experts to discuss the efficacy and barriers to using HP. Conclusions from the conference included the need for HP product specifications and standards of safety and efficacy, testing protocols, and efficacy trials. While no single entity was identified to advance these initiatives, this effort should be international and should involve collaboration between researchers, health care providers and policy-makers, and HP manufacturers. Plans are already underway for a second international conference in Europe to follow-up these recommendations and develop strategies for implementation. 相似文献
95.
沿海经济活动的发展与海洋/沿海环境之间的关系异常脆弱.但凡工业扩张的地方,海洋/沿海的生态系统就总体恶化.土地污染引发大量危害.对于旅游产业,特别是在岛屿地区,环境的危害必然会削弱这个产业."全球从陆地活动保护海洋环境的行动计划"谋求改变这种关系.它提出一个有效掌控陆地污染物的计划.未来的落实倚重合作伙伴,特别是私人部门发起或参与的行动. 相似文献
96.
Byung Kyu Kim Jamie Krams Erin Krug Mark Leaseburge Justin Lemley Ammar Alkhawaldeh Ray A. Mentzer M. Sam Mannan 《Journal of Loss Prevention in the Process Industries》2012,25(5):780-787
Several catastrophic events in the process industry have caused extensive damage to life and property and have forever changed the process safety landscape. Despite the commitment from the industry, incidents still occur with similar root causes, impacting major companies in various ways. This work examines the financial impact of such incidents on the stability and future of affected companies in different industries. Several devastating incidents were analyzed to evaluate the direct impact in the short- and long-term and to discuss factors influencing the ability of affected companies to withstand the consequence of catastrophic events. 相似文献
97.
98.
Erin E. Wilson-Rankin 《Behavioral ecology and sociobiology》2014,68(7):1151-1161
Social insects often serve as model systems for communication and recruitment studies, and yet, it remains controversial whether social vespid wasps can reliably communicate resource information to nestmates. In this study, I present empirical evidence that foraging strategies depend on the initial assessment of resource size and potential competition by foraging yellowjackets. The context dependent foraging behavior of Vespula pensylvanica provides a potential explanation for the inconsistent reports of the existence of recruitment communication in vespid wasps. Furthermore, life history traits may influence yellowjacket foraging behavior; annual V. pensylvanica colonies, whose foragers routinely patrol near the nest, exhibited increased bait visitation in response to the return of successful foragers, whereas perennial colonies did not. These behavioral disparities provide insight into how foraging strategies and search patterns may shift with colony size and longevity. In experiments that investigate the effects of visual cues of conspecifics and bait dispersion, foraging decisions corresponded with expectations of yellowjackets integrating resource quantity and access into a perception of demand. When resource competition could be assessed as high, V. pensylvanica foragers quickly exploited the bait closest to their colony regardless of occupation by other wasps; however, foragers preferred visiting unoccupied baits in situations where competition could be perceived as low. Moreover, a meta-analysis revealed that context-dependent, cue-mediated recruitment was widespread in Vespidae, where such foraging behaviors changed with habitat and the potential for resource competition. Such plastic foraging strategies may contribute to the invasion success of some vespid wasps. 相似文献
99.
100.
Elbroch M Mwampamba TH Santos MJ Zylberberg M Liebenberg L Minye J Mosser C Reddy E 《Conservation biology》2011,25(6):1195-1202
Abstract: Evidence suggests that the involvement of local people in conservation work increases a project's chances of success. Involving citizen scientists in research, however, raises questions about data quality. As a tool to better assess potential participants for conservation projects, we developed a knowledge gradient, K, along which community members occupy different positions on the basis of their experience with and knowledge of a research subject. This gradient can be used to refine the citizen–science concept and allow researchers to differentiate between community members with expert knowledge and those with little knowledge. We propose that work would benefit from the inclusion of select local experts because it would allow researchers to harness the benefits of local involvement while maintaining or improving data quality. We used a case study from the DeHoop Nature Preserve, South Africa, in which we conducted multiple interviews, identified and employed a local expert animal tracker, evaluated the expert's knowledge, and analyzed the data collected by the expert. The expert animal tracker J.J. created his own sampling design and gathered data on mammals. He patrolled 4653 km in 214 days and recorded 4684 mammals. He worked from a central location, and his patrols formed overlapping loops; however, his data proved neither spatially nor temporally autocorrelated. The distinctive data collected by J.J. are consistent with the notion that involving local experts can produce reliable data. We developed a conceptual model to help identify the appropriate participants for a given project on the basis of research budget, knowledge or skills needed, technical literacy requirements, and scope of the project. 相似文献