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131.
Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement‐based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species’ 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of <100 nesting females/annum. This bycatch rate is likely slowing population growth. Artisanal fisheries may be of greater concern for loggerheads than for leatherbacks, but the population appears to be withstanding the high bycatch rates because it is increasing exponentially. The hydrocarbon industry currently has a moderately low impact on both species, but mining in key areas (e.g., Southern Mozambique) may undermine >50 years of conservation, potentially affecting >80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives.  相似文献   
132.
Previous studies described the use of potassium dichromate (K2Cr2O7) to successfully preserve whole blood for up to 34 days at room temperature (20–22°C) for analysis of chlorinated dioxins, dibenzofurans and PCBs. Potassium dichromate has been successfully employed as a preservative for cows’ milk and in a World Health Organization study of human milk. The use of two 100?mg tablets in 40 to 100?mL of whole blood in anticoagulant was found to provide almost identical levels of dioxins, dibenzofurans, PCBs and lipids as found in frozen comparison blood at??70°C which is generally regarded as the gold standard for blood preservation. Potassium dichromate was found to be preferable to 20 and 40% ethyl alcohol for this preservation. This finding opens opportunities for preservation under field conditions in developing countries where neither electricity nor dry ice is available. Not having to use dry ice for shipping also allows more flexibility in the choice of commercial carriers for transporting blood to an analytical laboratory. It is recommended considering a number of compounds in addition to those studied in our first report and extending the time beyond 34 days in order to determine if longer storage might also be feasible. Data on polybrominated diphenyl ethers (PBDEs), as well as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and selected polychlorinated biphenyls (PCBs) are reported. For the present study 3 and 6 months were chosen in potassium dichromate at room temperature compared to freezing at ?70°C. Data indicate that these times exceed the limits of efficacy of potassium dichromate for whole blood preservation. This was attributed to degradation of the lipid component of the blood. Since dioxins and closely related structural analogues are traditionally reported as lipid normalized blood levels, this degradation of lipids provides erroneous results. Therefore, potassium dichromate is not recommended for long-term storage beyond 34 days at room temperature. It is planned to study the time period between one and three months and higher temperature preservation for shorter time periods, simulating conditions in tropical countries, to attempt to extend further the ease and convenience of chemical preservation of blood.  相似文献   
133.
Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants (BFRs) which have recently been detected in human blood and milk in the USA, and presently these PBDE levels are found to be the highest globally. On a population basis, individual blood and individual milk analyses show similar congener patterns and levels. Until now, there has not been a study comparing PBDE levels in milk and blood of the same individuals. This study is the first to report these levels for PBDEs, though partitioning between blood and milk has been done previously for dioxins and polychlorinated biphenyls (PCBs). Twelve congeners in 11 nursing mothers’ blood and milk were found and the data describe partitioning ratios between blood and milk. The data suggest it may be easier for smaller, less brominated congeners to move from blood to milk.  相似文献   
134.
Antimicrobial agents in the environment are a cause for concern. Antimicrobial drug residues and their metabolites reach the aquatic and terrestrial environment primarily through wastewater treatment plants (WWTP). In addition to the potential direct negative health and environmental effects, there is potential for the development of antimicrobial-resistant bacteria. Residue levels below the minimum inhibitory concentration for a bacterial species can be important in selection of resistance. There is uncertainty associated with resistance formation during WWTP processing. A meta-analysis study was carried out to analyse the effect of WWTP processing on the levels of antimicrobial-resistant bacteria within bacterial populations. An analysis of publications relating to multiple antimicrobial-resistant (MAR) bacteria (n?=?61), single antimicrobial-resistant (SAR) E. coli (n?=?81) and quinolone/fluoroquinolone-resistant (FR) bacteria (n?=?19) was carried out. The odds-ratio (OR) of MAR (OR?=?1.60, p?<?0.01), SAR (OR?=?1.33, p?<?0.01) and FR (OR?=?1.19, p?<?0.01) bacteria was determined. The results infer that WWTP processing results in an increase in the proportion of resistant bacteria in effluent, even though the overall bacterial population may have reduced (i.e. a reduction in total bacterial numbers but an increase in the percentage of resistant bacteria). The results support the need for further research into the development of antimicrobial-resistant strains and possible selective pressures operating in WWTPs.  相似文献   
135.
This paper highlights the increasing concerns relating to hydroenvironmetal issues and cites recent examples of the challenges now being regularly faced by hydroenvironmetal scientists and engineers. The limitations and restrictions of both physical (or laboratory) and numerical (or computer based) hydraulic models used in the planning and management of aquatic basins are discussed. General details are given of numerical models used for flow and water quality concentration predictions in estuarine waters, with particular application to the challenges occurring along the South Wales coast. A highly accurate and non-diffusive finite difference scheme that solves the transport equation for predicting water quality indicators and suspended sediment concentration distributions is also discussed. In particular, details are outlined of the extension of the water quality indicators of faecal coliforms, as required to comply with the EU Bathing Water Directive, to predict health risk assessment, in the form of predicting the risk of gastroenteritis. Three example research projects along the South Wales coast are described; the projects involve the application of two-dimensional and three-dimensional hydroenvironmetal models to predict flow patterns and water quality indicator organism distributions in the coastal receiving waters. These studies include: (i) a curvilinear finite difference approach to modelling flows in the Bristol Channel, (ii) coastal health risk predictions in Swansea Bay using combined water quality and epidemiological models, and (iii) combined sewer overflow discharges into Cardiff Bay.  相似文献   
136.
In response to lingering concerns about the utility of dynamometer data for mobile source emissions modeling, the U.S. Environmental Protection Agency (EPA) has constructed an on-road test facility to characterize the real-world emissions of heavy-duty trucks. The facility was designed to effectively demonstrate the full range of vehicle operation and to measure the emissions produced. Since it began operation, the facility has been continuously upgraded to incorporate state-of-the-art technology. Its potential uses include collecting modal emissions data, validating dynamometer test parameters and results, and demonstrating new emission control technologies.  相似文献   
137.
PROBLEM: Braking time (BT) is a critical component in safe driving, and various approaches have been applied to minimize it. This study analyzed the components of BT in order to assess the effects of age, gender, vehicle transmission type, and event uncertainty, on its two primary components, perception-reaction time and brake-movement time. METHOD: Perception-reaction time and brake-movement time were measured at the onset of lights for 72 subjects in a simulator. The six experimental conditions were three levels of uncertainty conditions (none, some, and some + false alarms) and two types of transmission (manual and automatic). The 72 subjects, half male and half female, were further divided into three age groups (mean of 23, 30, and 62 years). Each subject had 10 trials in each of the three levels of uncertainty conditions. RESULTS: Transmission type did not significantly affect either perception-reaction time or brake-movement time. Perception-reaction time increased significantly from 0.32 to 0.42 s (P < .05) as uncertainty increased but brake-movement time did not change. Perception-reaction time increased (from 0.35 to 0.43 s) with age but brake-movement time did not change with age. Gender did not affect perception-reaction time but did affect brake-movement time (males 0.19 s vs. females 0.16 s). IMPACT ON INDUSTRY: At 90 km/h, a car travels 0.25 m in 0.01 s. Consequently, even such small effects multiplied by millions of vehicle-kilometers can contribute to significant savings in lives and damages.  相似文献   
138.
Based on the theoretical identification of three different motivational forces for voluntary turnover—affective, calculative, and alternative—we hypothesize that the relationship between supervisor–subordinate relationship quality (i.e., leader–member exchange) and turnover intentions is best represented as curvilinear as opposed to linear. We test this hypothesis in two organizational samples consisting of 402 employees from a water management district and 183 employees from a distribution services organization. We found support for the hypothesis in both samples. We offer directions for future research. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
139.
We examined the geology of a small inland wetland in Hampton, Connecticut to determine its postglacial history and to assess the severity of human impact at this remote wooded site. Using stratigraphic evidence, we dernonstrate that the present wetland was created when sediment pollution from a 19th-century railroad filled a preexisting artificial reservoir, and that the prehistoric wetland was a narrow drainage swale along Hampton Brook. This same, severely impacted wetland was interpreted by the Pulitzer Prize-winning naturalist Edwin Way Teale as a beautiful wilderness area of particular interest. These conflicting perceptions indicate that artificial wetlands can be naturally mitigated in less than a century of healing, even in the absence of deliberate management. We also point out that the “wilderness” value of the Teale wetland was in the eye of the beholder and that unseen human impacts may have improved the aesthetic experience.  相似文献   
140.
ABSTRACT: Problems of water quality and quantity are critical to development of the energy resources of the Western U. S. Based on a number of independent measures, the Upper Colorado River Basin will experience severe water availability problems in a few decades if projected energy and agricultural development occurs. Given the impending collision between the competing interests of various Western water users, water resource management and conservation deserves the utmost attention. Substantial opportunities for conservation exist in energy and agricultural development. Selection of both conversion and cooling technologies and careful siting decisions can sharply reduce the water requirements of energy development. Agricultural water conservation strategies include improving irrigation and cultivation practices, removing phreatophytes, removing marginal lands from production, and changing crop patterns. In order to accomplish significant conservation, however, there must be changes in those aspects of Western water law that remove conservation incentives from the water use system.  相似文献   
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