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201.
The International Center for Alcohol Policies (ICAP) has developed an international program to reduce drink driving as part of its strategy for Global Actions on Harmful Drinking. The program focuses on capacity building, training, and the implementation, monitoring, and evaluation of regional and local pilot projects in 6 participating low- and middle-income countries. The first step in developing an effective program that addresses specific problems in a region or country is to assess the current drink driving situation. In order to meet this key requirement, ICAP developed a situation assessment approach based largely on the recommendations of Chapter 2 of the good practice manual on drinking and driving produced by the Global Road Safety Partnership (GRSP) under the auspices of the United Nations (UN) Road Safety Collaboration. The aim of the assessment was to provide the foundation for preparing a prioritized and effective suite of projects using the good practice recommended by the GRSP/UN manual. Its output is intended to assist with determining program objectives, design, and evaluation so that the benefits from the investments in drink driving programs can be maximized and data led, focusing on the priorities identified by the assessment. The situation assessment approach was produced as a set of guidelines containing a detailed and structured list of questions. The questions are organized into 6 main groups or elements and they enable a comprehensive and systematic collection of existing information about the extent and nature of the drink driving problem, the strengths and weaknesses of the current prevention practices, and the capacity for improvements. Situation assessments using these guidelines have been completed in the 6 focus countries and the resulting information is now being used for capacity building and developing appropriate and relevant pilot projects, taking into consideration the country's culture with respect to transportation, enforcement, health care, and alcohol consumption.  相似文献   
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203.
Between 1990 and 2007, 15 southern white (Ceratotherium simum simum) and black (Diceros bicornis) rhinoceroses on average were killed illegally every year in South Africa. Since 2007 illegal killing of southern white rhinoceros for their horn has escalated to >950 individuals/year in 2013. We conducted an ecological–economic analysis to determine whether a legal trade in southern white rhinoceros horn could facilitate rhinoceros protection. Generalized linear models were used to examine the socioeconomic drivers of poaching, based on data collected from 1990 to 2013, and to project the total number of rhinoceroses likely to be illegally killed from 2014 to 2023. Rhinoceros population dynamics were then modeled under 8 different policy scenarios that could be implemented to control poaching. We also estimated the economic costs and benefits of each scenario under enhanced enforcement only and a legal trade in rhinoceros horn and used a decision support framework to rank the scenarios with the objective of maintaining the rhinoceros population above its current size while generating profit for local stakeholders. The southern white rhinoceros population was predicted to go extinct in the wild <20 years under present management. The optimal scenario to maintain the rhinoceros population above its current size was to provide a medium increase in antipoaching effort and to increase the monetary fine on conviction. Without legalizing the trade, implementing such a scenario would require covering costs equal to approximately $147,000,000/year. With a legal trade in rhinoceros horn, the conservation enterprise could potentially make a profit of $717,000,000/year. We believe the 35‐year‐old ban on rhinoceros horn products should not be lifted unless the money generated from trade is reinvested in improved protection of the rhinoceros population. Because current protection efforts seem to be failing, it is time to evaluate, discuss, and test alternatives to the present policy.  相似文献   
204.
The Ecological Society of America has evaluated current U.S. national policies and practices on biological invasions in light of current scientific knowledge. Invasions by harmful nonnative species are increasing in number and area affected; the damages to ecosystems, economic activity, and human welfare are accumulating. Without improved strategies based on recent scientific advances and increased investments to counter invasions, harm from invasive species is likely to accelerate. Federal leadership, with the cooperation of state and local governments, is required to increase the effectiveness of prevention of invasions, detect and respond quickly to new potentially harmful invasions, control and slow the spread of existing invasions, and provide a national center to ensure that these efforts are coordinated and cost effective. Specifically, the Ecological Society of America recommends that the federal government take the following six actions: (1) Use new information and practices to better manage commercial and other pathways to reduce the transport and release of potentially harmful species; (2) Adopt more quantitative procedures for risk analysis and apply them to every species proposed for importation into the country; (3) Use new cost-effective diagnostic technologies to increase active surveillance and sharing of information about invasive species so that responses to new invasions can be more rapid and effective; (4) Create new legal authority and provide emergency funding to support rapid responses to emerging invasions; (5) Provide funding and incentives for cost-effective programs to slow the spread of existing invasive species in order to protect still uninvaded ecosystems, social and industrial infrastructure, and human welfare; and (6) Establish a National Center for Invasive Species Management (under the existing National Invasive Species Council) to coordinate and lead improvements in federal, state, and international policies on invasive species. Recent scientific and technical advances provide a sound basis for more cost-effective national responses to invasive species. Greater investments in improved technology and management practices would be more than repaid by reduced damages from current and future invasive species. The Ecological Society of America is committed to assist all levels of government and provide scientific advice to improve all aspects of invasive-species management.  相似文献   
205.
For nearly a century researchers have investigated the uptake and utilization of dissolved organic matter (DOM) by marine invertebrates, but its contribution to their growth, reproduction, and survival remains unclear. Here, the benefit of DOM uptake was assessed for the marine bryozoan Bugula neritina (Linnaeus 1758) through performance comparisons of individuals in the presence and absence of DOM. The experiments were performed using B. neritina collected from floating docks in Beaufort, NC, USA from July to September 2004. Seawater was subjected to ultraviolet irradiation to reduce naturally occurring DOM, and then enriched with either 1 μM of palmitic acid or a mixture containing 1 μM each of glucose, alanine, aspartic acid and glycine. Larvae in DOM-enriched and DOM-reduced treatments were sampled and induced to metamorphose following 1, 6, 12, and 24 h of continuous swimming at 25°C. Sampled larvae were assessed for initiation of metamorphosis, completion of metamorphosis, and ancestrular lophophore size to determine the extent to which energy acquired from DOM uptake could offset the metabolic costs of prolonged larval swimming. DOM treatment had no significant effect on initiation of metamorphosis, but did have a significant effect on completion of metamorphosis and lophophore size. Larvae swimming in DOM-enriched treatments for 24 h experienced a 20% increase in metamorphic completion rate, compared to larvae swimming for 24 h in the DOM-reduced treatment. In addition, larvae in the amino acid and sugar mixture for 24 h had a significantly larger lophophore surface area and volume (23 and 31%, respectively), compared to larvae in DOM-depleted seawater. To ensure that the increases in performance found in larvae with access to DOM were not due to a decrease in metabolic activity, the respiration rates for these larvae were compared to those of larvae in DOM-depleted seawater. There were no significant differences between these treatments, indicating that the increases in performance were due to the energy acquired from DOM. These results clearly show that for B. neritina, DOM uptake results in increased metamorphic success and in the size of the feeding apparatus following an extended larval swimming duration.  相似文献   
206.
Allozyme diversity was examined in four rare, high-montane plant species from the Appalachian Mountains of southeastern North America. These species may represent relictual members or descendants of an alpine community that was more widespread during the late Pleistocene. We sampled five populations of Geum radiatum (Rosaceae), Carex misera (Cyperaceae), Trichophorum cespitosum (Cyperaceae), and the four known populations of Calamagrostis cainii (Poaceae). Genetic diversity was low for all species but was typical of that found for plant species with limited ranges. Low genetic diversity may reflect historical events associated with changes in the species' biogeography. As the Pleistocene climate warmed, suitable habitat decreased in areal extent and became fragmented, probably resulting in smaller, more-isolated populations. In recent times these species, which co-occur in fragile rock outcrop habitats, have been adversely affected by human activities. Genetic analyses revealed reduced diversity in populations of decreasing size for three species. Estimates of gene flow were low ( Nm < 1.0) in all four species. Positive associations between genetic diversity and population size, evidence of recent population declines, and the low estimates of gene flow suggest that genetic drift may play a prominent role in shaping the present-day genetic composition of these species. Furthermore, these data suggest that the genetically depauperate populations are unlikely to regain genetic variation without human intervention.  相似文献   
207.
High-precision lead isotope ratios and lead concentrations have been compared statistically and graphically in women of child-bearing age (n = 77) from two smelter communities and one general urban community to evaluate the relative contributions to blood lead of tissue lead stores and lead from the contemporaneous environment (soil, floor dust, indoor airborne dust, water, food). Blood lead (PbB) contents were generally low (e.g. <10 g dL–1). Statistically significant isotopic differences in blood and environmental samples were observed between the three cities although isotopic differences in blood for individual subjects living in close proximity (200 m radius) was as large as the differences within a city. No single environmental measure dominated the biological isotope profile and in many cases the low levels of blood lead meant that their isotopic profiles could be easily perturbed by relatively small changes of environmental exposure. Apportioning of sources using lead isotopes is possibly not feasible, nor cost effective, when blood lead levels are <5 g dL–1. Interpretations based on statistical analyses of city-wide data do not give the same conclusions as when the houses are considered individually. Aggregating data from multiple subjects in a study such as this obscures potentially useful information. Most of the measures employed in this study, and many other similar studies, are markers of only short-to-medium integration of lead exposure. Serial sampling of blood and longer sampling times, especially for household variables, should provide more meaningful information.  相似文献   
208.
The geochemistry of iodine — a review   总被引:1,自引:0,他引:1  
Iodine has long been recognised as an important element environmentally. Despite this there are many gaps in our knowledge of its geochemistry and even where information is available much of this is based on old data which, in the light of recent data, are suspect.Iodine forms few independent minerals and is unlikely to enter most rock-forming minerals. In igneous rocks its concentration is fairly uniform and averages 0.24 mg/kg. Sedimentary rocks tend to have higher concentrations with average iodine contents of:-recent sediments 5–200 mg/kg, carbonates 2.7 mg/kg, shales 2.3 mg/kg and sandstones 0.8 mg/kg. Organic-rich sediments are particularly enriched in iodine.Soils, generally, are much richer in iodine than the parent rocks with the actual level being decided mainly by soil type and locality. Little soil iodine is water-soluble and much iodine is thought to be associated with organic matter, clays and aluminium and iron oxides. Most iodine in soils is derived from the atmosphere where, in turn, it has been derived from the oceans. Seawater has a mean iodine content of 58 g/L, while non-saline surface waters have lower and very variable levels. Subsurface brines and mineral waters are generally strongly enriched in iodine.Marine plants are frequently enriched in iodine while terrestrial plants have generally low contents. Iodine is essential for all mammals.Consideration of the geochemical cycle of iodine reveals that its transfer from the oceans to the atmosphere is probably the most important process in its geochemistry.  相似文献   
209.
Summary. Aphid colonies can reach high levels of abundance but last for short periods of time. The larvae of aphidophagous ladybirds (Coleoptera: Coccinellidae) that feed on these colonies might therefore suffer from starvation, which favours the occurrence of cannibalism and intraguild predation. Thus, the assessment of patch quality becomes crucial and it has been shown that female ladybirds refrain from laying eggs in the presence of an oviposition deterring semiochemical deposited by their larvae. Adalia bipunctata (L.), Adalia decempunctata (L.) and Coccinella septempunctata L. are 3 sympatric species of ladybirds, which can co-occur in aphid colonies. As a consequence, their eggs and larvae are under threat, not only from cannibalism but also intraguild predation. Females should, therefore, also use the tracks deposited by heterospecific larvae to assess the quality of aphid colonies as oviposition sites. The expectation is that: 1- the strength of the reaction to each other’s larval tracks should be correlated with percentage habitat overlap and that 2- the reaction to conspecific larval tracks should be stronger than to heterospecific tracks. In order to test these hypotheses, females’ oviposition behaviour was analysed and a chemical analysis of the tracks of their larvae undertaken. The results show that oviposition behaviour is not related to habitat overlap. Both species of Adalia react to tracks of their own larvae and those of C. septempunctata, but A. decempunctata reacted more strongly than A. bipunctata. C. septempunctata reacted very slightly to its own tracks but not to those of either species of Adalia. The larval tracks are mainly composed of alkanes. Those of the two species of Adalia are qualitatively 100% similar and 60% so when the quantitative results are compared. They are, however, only 24–29% similar to those of Coccinella septempunctata.  相似文献   
210.
Adult sockeye salmon (Oncorhynchus nerka, N = 179) from six Fraser River populations (British Columbia) were intercepted in continental shelf waters ∼215 km from the Fraser River mouth, gastrically implanted with acoustic transmitters, non-lethally biopsied for blood biochemistry, gill Na+,K+-ATPase activity and somatic energy density and then released. Migration behaviour and travel times to the river mouth and into the river were monitored by underwater telemetry receivers positioned at the river mouth and in the river. Post-release survival of salmon was excellent, with 84% (N = 150) of fish reaching the furthest receiving station ∼85 km upriver. Fish from Late-summer run populations (Adams and Weaver Creek) averaged a migration rate of ∼20 km day−1 through the marine area and held at the river mouth and adjacent areas for 7–9 days before entering the river. Summer-run populations (Birkenhead, Chilko, Horsefly and Stellako) had a migration rate ∼33 km day−1 and held for only 1–3 days. Once in river, similar patterns were observed: Late-run populations migrated at ∼28 km day−1 and Summer-run populations at ∼40 km day−1. From point of release to the river mouth, males migrated faster than females, but once in river migration rates did not differ between sexes. Among all females, a correlation was discovered between levels of circulating testosterone and river entry timing. This correlation was not observed among males. Plasma K+, Cl, glucose, lactate and osmolality were also correlated with entry timing in both sexes.  相似文献   
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