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21.
ABSTRACT

Non-methane organic compound (NMOC) profiles for on-road motor vehicle emissions were measured in a downtown tunnel and parking garages in Mexico City during 1996. Hydrocarbon samples from the tunnel and ambient air samples (C2-C12) were collected using stainless steel canisters, and carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated cartridges. Canister samples were analyzed by gas chromatog-raphy/flame ionization detection (GC/FID) to ascertain detailed hydrocarbon composition. DNPH samples were analyzed by high performance liquid chromatography (HPLC). NMOC source profiles were quantified for evaporative emissions from refueling, cold start, and hot soak, and on-road operating conditions. The ultimate purpose will be to determine the apportionment of ambient NMOC concentrations using the Chemical Mass Balance (CMB) model. The tunnel profile contained 42.3 ppbC% of alkanes, 20.6 ppbC% of unsaturated compounds, and 22.4 ppbC% of aromatics. The most abundant species were acetylene with 7.22 ppbC%, followed by ipentane with 5.69 ppbC%, and toluene with 5.42 ppbC%. These results were compared with those from studies in the United States. The cold start profile was found to be similar to the tunnel profile, although there were differences in the content of acetylene, isopentane, and oxygenates. The abundance of saturated NMOC in the hot soak profile was similar to gasoline head space profiles; it was also much larger than saturated NMOC in the roadway profile.  相似文献   
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An insect parasitoid carrying an ochratoxin producing fungus   总被引:2,自引:0,他引:2  
The insect parasitoid Prorops nasuta has been introduced from Africa to many coffee-producing countries in an attempt to control the coffee berry borer. In this paper, we report on the sequencing of the ITS LSU-rDNA and beta-tubulin loci used to identify a fungus isolated from the cuticle of a P. nasuta that emerged from coffee berries infected with the coffee berry borer. The sequences were compared with deposits in GenBank and the fungus was identified as Aspergillus westerdijkiae. The fungus tested positive for ochratoxin A production, with varying levels depending on the media in which it was grown. These results raise the possibility that an insect parasitoid might be disseminating an ochratoxin-producing fungus in coffee plantations.  相似文献   
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We present a decision support framework for science-based assessment and multi-stakeholder deliberation. The framework consists of two parts: a DPSIR (Drivers–Pressures–States–Impacts–Responses) analysis to identify the important causal relationships among anthropogenic environmental stressors, processes, and outcomes; and a Decision Landscape analysis to depict the legal, social, and institutional dimensions of environmental decisions. The Decision Landscape incorporates interactions among government agencies, regulated businesses, non-government organizations, and other stakeholders. It also identifies where scientific information regarding environmental processes is collected and transmitted to improve knowledge about elements of the DPSIR and to improve the scientific basis for decisions. Our application of the decision support framework to coral reef protection and restoration in the Florida Keys focusing on anthropogenic stressors, such as wastewater, proved to be successful and offered several insights. Using information from a management plan, it was possible to capture the current state of the science with a DPSIR analysis as well as important decision options, decision makers and applicable laws with a the Decision Landscape analysis. A structured elicitation of values and beliefs conducted at a coral reef management workshop held in Key West, Florida provided a diversity of opinion and also indicated a prioritization of several environmental stressors affecting coral reef health. The integrated DPSIR/Decision landscape framework for the Florida Keys developed based on the elicited opinion and the DPSIR analysis can be used to inform management decisions, to reveal the role that further scientific information and research might play to populate the framework, and to facilitate better-informed agreement among participants.  相似文献   
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江西武夷成矿带铜多金属矿产资源远景评价与展望   总被引:1,自引:0,他引:1  
华南武夷山地区处于扬子、华夏两大构造单元交接叠加地段,构造变形复杂,中生代岩浆活动强烈,具有十分优越的成矿条件,矿产资源潜力巨大.本文以正在武夷山成矿带开展的矿产远景调查工作和资源评价工作所取得的阶段性成果为基础,分析了武夷山成矿带的成矿地质背景、主要矿床类型及近几年的找矿勘查成果,并对武夷成矿带江西省境内铜多金属矿产资源潜力进行了初步评价,划分了十七个找矿远景区.  相似文献   
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Environmental Geochemistry and Health - Civilian and military shooting range facilities cause environmental issues in several countries due to the accumulation of Potentially Toxic Elements; as a...  相似文献   
28.
An 8.8‐magnitude earthquake occurred off the coast of Chile on 27 February 2010, displacing nearly 2,000 children aged less than five years to emergency housing camps. Nine months later, this study assessed the needs of 140 displaced 0–5‐year‐old children in six domains: caregiver stability and protection; health; housing; nutrition; psychosocial situation; and stimulation. Multivariate regression was applied to examine the degree to which emotional, physical, and social needs were associated with baseline characteristics and exposure to the earthquake, to stressful events, and to ongoing risks in the proximal post‐earthquake context. In each domain, 20 per cent or fewer children had unmet needs. Of all children in the sample, 20 per cent had unmet needs in multiple domains. Children's emotional, physical, and social needs were associated with ongoing exposures amenable to intervention, more than with baseline characteristics or epicentre proximity. Relief efforts should address multiple interrelated domains of child well‐being and ongoing risks in post‐disaster settings.  相似文献   
29.
The objective of this study was to evaluate the presence of organochlorine pesticides in samples of forage, soil, water, and milk in four units of an organic production system for cow´s milk (samples of forage, milk, soil, and water) in Tecpatan, Chiapas, Mexico. The organochlorine pesticides were extracted from forage, soil and water based on the USEPA (2005) guideline and from milk based on the IDF 1991 guideline. The pesticides were identified and quantified by gas chromatography with electron capture detector (CG-ECD). In general, the highest average concentration of total pesticides was found in the samples of milk and forage (311 ± 328 and 116.5 ±77 ng g?1 respectively). Although, the production systems analyzed are organic, organochlorine pesticides were detected in all environmental samples (forage, soil, water, and organic milk). Although no values surpassed the defined limits of Mexican and International regulation it is advisable that a monitoring program of contaminants in these production systems is continued.  相似文献   
30.
This study describes the density variation and phenology of Macrocystis integrifolia and M. pyrifera populations from northern and southern Chile, respectively. Samples of both species were taken in wave-exposed and wave-protected areas. In addition, spore production, germination and early growth rate of sporophytes of each population was studied at monthly intervals under three temperature and salinity regimes. Results indicate that M. integrifolia from northern Chile presents perennial plants with a mean density of three individuals per 0.25 m2 throughout the year and that it reproduces mainly during spring and winter. Although, M. pyrifera in exposed areas of southern Chile also have a perennial-type life strategy, they are able to reproduce all year round. In contrast, M. pyrifera populations in protected areas of southern Chile show a clear annual cycle, with high recruitment during late winter and fertile sporophytes in summer and autumn, although the populations become completely decimated thereafter. The effect of temperature and salinity on M. integrifolia shows that it is independent of water movement, but requires low temperatures and high salinities for the release of zoospores, germination and early sporophyte growth. This pattern differs from that of M. pyrifera in southern Chile, which has a broader tolerance range for salinity and temperature than does M. integrifolia. However, in southern Chile wave-protected populations showed higher spore release and germination at 15°C and 18°C, whereas sporophyte growth responded better at the lowest temperature tested (8°C). In general, these results are contrary to those expected, since a seasonal reproductive pattern was observed in M. integrifolia inhabiting a less seasonally variable environment. In exposed sites of southern Chile, plants showed greater tolerance and continuous reproduction throughout the year, despite the greater environmental variability. Finally, population dynamics of protected kelps in southern Chile shows an annual pattern, which is contrary to the expected perennial strategy shown by exposed populations.Communicated by P.W. Sammarco, Chauvin  相似文献   
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