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451.
Intensifying global trade will result in increased numbers of plant pest and pathogen species inadvertently being transported along with cargo. This paper examines current mechanisms for prevention and management of potential introductions of forest insect pests and pathogens in the European Union (EU). Current European legislation has not been found sufficient in preventing invasion, establishment and spread of pest and pathogen species within the EU. Costs associated with future invasions are difficult to estimate but past invasions have led to negative economic impacts in the invaded country. The challenge is combining free trade and free movement of products (within the EU) with protection against invasive pests and pathogens. Public awareness may mobilise the public for prevention and detection of potential invasions and, simultaneously, increase support for eradication and control measures. We recommend focus on commodities in addition to pathways, an approach within the EU using a centralised response unit and, critically, to engage the general public in the battle against establishment and spread of these harmful pests and pathogens.  相似文献   
452.
The availability of affordable ‘recreational’ camera traps has dramatically increased over the last decade. We present survey results which show that many conservation practitioners use cheaper ‘recreational’ units for research rather than more expensive ‘professional’ equipment. We present our perspective of using two popular models of ‘recreational’ camera trap for ecological field-based studies. The models used (for >2 years) presented us with a range of practical problems at all stages of their use including deployment, operation, and data management, which collectively crippled data collection and limited opportunities for quantification of key issues arising. Our experiences demonstrate that prospective users need to have a sufficient understanding of the limitations camera trap technology poses, dimensions we communicate here. While the merits of different camera traps will be study specific, the performance of more expensive ‘professional’ models may prove more cost-effective in the long-term when using camera traps for research.  相似文献   
453.
Three men were killed and four others were injured during a well drill operation on Hobson Well C-10A in the Sea Cliff Oil Field (also known as Rincon Oil Field), in Ventura County, California, United States, on August 10, 1994, as a result of errors made by the work supervisors at the site. The oil field was under management by Vintage Petroleum, Ltd., which was sued for negligence by the families of the deceased and injured. The coroner's autopsy examination concluded that the cause of the deaths was due to the inhalation of the toxic gas carbon monoxide (CO). This gas was assumed to have been released from the firing of high-energy guns (HEGs) using carbon-rich explosive pentaerythritol tetranitrate (PETN) in an oxygen-depleted environment, during a fracking operation by Schlumberger Corporation on Well C-10A. The author of this article was appointed as an expert witness by Schlumberger to evaluate if the coroner's conclusion was correct. A series of chemical analytical analyses were conducted on the vapor phase of samples, in addition to dissolved components in water from Well C-10A and two adjacent wells. Stable isotope analyses were also conducted on hydrogen (H2), methane (CH4), nitrogen (N2), CO, and water (H2O) 3 weeks after the accident, as well as on four additional occasions from September to December 1994. Control test analyses were performed on the products from HEG firings, using the same explosives as those used in the perforation of Well C-10A in control chambers at a Schlumberger facility in Houston, Texas. The conclusion reached was that the dominant products of PETN detonations are H2, CH4, CO, and N2. However, the isotope ratios (D/H and 13C/12C) of methane in the control experiments were different in Well C-10A, following the detonation on August 10, 1994, than those resulting from controlled PETN explosions. The conclusion reached in this study was that the fracking of the well at a depth of around 2,150 ft had increased the permeability of the sediment layers in the Padres Zone at that depth to allow the rapid release of a large quantity of natural gas, primarily CH4, which supersaturated the water in the well. This event caused the formation of a large bubble, which ballooned out of the well to the surface, displacing air in the location where the men were working, and thus causing asphyxiation, which resulted in the death of the three men. The judge accepted this interpretation.  相似文献   
454.
Ambio - The choice of tree species used in production forests matters for biodiversity and ecosystem services. In Sweden, damage to young production forests by large browsing herbivores is helping...  相似文献   
455.
The Australian and New Zealand Guidelines for Fresh and Marine Water Quality are a key document in the Australian National Water Quality Management Strategy. These guidelines released in 2000 are currently being reviewed and updated. The revision is being co-ordinated by the Australian Department of Sustainability, Environment, Water, Population and Communities, while technical matters are dealt with by a series of Working Groups. The revision will be evolutionary in nature reflecting the latest scientific developments and a range of stakeholder desires. Key changes will be: increasing the types and sources of data that can be used; working collaboratively with industry to permit the use of commercial-in-confidence data; increasing the minimum data requirements; including a measure of the uncertainty of the trigger value; improving the software used to calculate trigger values; increasing the rigour of site-specific trigger values; improving the method for assessing the reliability of the trigger values; and providing guidance of measures of toxicity and toxicological endpoints that may, in the near future, be appropriate for trigger value derivation. These changes will markedly improve the number and quality of the trigger values that can be derived and will increase end-users’ ability to understand and implement the guidelines in a scientifically rigorous manner.  相似文献   
456.
A study of the anaerobic treatment of wastewaters derived from red (RWWW) and tropical fruit wine (TFWWW) production was carried out in four laboratory-scale fluidized bed reactors with natural zeolite as bacterial support. These reactors operated at mesophilic temperature (35°C). Reactors R1 and R2 contained Chilean natural zeolite, while reactors R3 and R4 used Cuban natural zeolite as microorganism support. In addition, reactors R1 and R3 processed RWWW, while reactors R2 and R4 used TFWWW as substrate. The biomass concentration attached to zeolites in the four reactors studied was found to be in the range of 44–46 g volatile solids (VS)/L after 90 days of operation time. Both types of zeolites can be used indistinctly in the fluidized bed reactors achieving more than 80%–86% chemical oxygen demand (COD) removals for organic loading rates (OLR) of up to at least 20 g COD/L d. pH values remained within the optimal range for anaerobic microorganisms for OLR values of up to 20 and 22 g COD/L d for RWWW and TFWWW, respectively. Toxicity and inhibition levels were observed at an OLR of 20 g COD/L d in reactors R1 and R3 while processing RWWW, whereas the aforementioned inhibitory phenomena were not observed at an OLR of 24 g COD/L d in R2 and R4, treating TFWWW as a consequence of the lower phenolic compound content present in this substrate. The volatile fatty acid (VFA) levels were always lower in reactors processing TFWWW (R2 and R4) and these values (< 400 mg/L, as acetic acid) were lower than the suggested limits for digester failure. The specific methanogenic activity (SMA) was twice as high in reactors R2 and R4 than in R1 and R3 after 120 days of operation when all reactors operated at an OLR of 20 g COD/L d.  相似文献   
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