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401.
After a critical analysis of the strategies for conservation of the environment in Latin America and of large-scale development projects (agriculture and livestock raising, mining and electrical power plants) in the Amazon region of Brazil, this paper deals with the use of high-resolution satellite imagery for environmental monitoring. Two areas were considered in the study, Tucurui and Altamira. Spot/XS and Landsat/TM multispectral images were used, together with color aerial photographs of these areas. A computer-assisted visual interpretation procedure was employed to analyze images, and linear multispectral transformation was applied in selected subscenes in order to improve information extraction. The results indicate that high-resolution satellite imagery is generally compatible with the scale of the environmental problems in Amazonia and is a very efficient source of detailed information at a local scale on many aspects of the environment, in particular for monitoring changes over time in selected areas. Therefore, commercial satellite imagery, processed by specialized software, can accommodate a variety of analysis needs for decision makers and can also be an effective means of verification of international agreements on conservation of the environment in Amazonia.  相似文献   
402.
The variation of risk estimates in second trimester maternal serum screening for Down's syndrome has been shown to be considerable in quality control schemes, i.e. UKNEQAS. We studied the biological variation of risk estimates in 16 women through pregnancy. The maternal serum markers alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE3) and β-hCG were determined six times during late first to late second trimester, and the associated likelihood ratios for Down syndrome were calculated. The interpersonal variation of markers, as well as that of the likelihood ratio, was much greater than the intrapersonal variation. The average intrapersonal standard deviation (SD) of the triple test log likelihood ratio was 0.2291, corresponding to a central 95-percentile interval 0.36–2.81 of the likelihood ratio. The interpersonal SD of the log likelihood ratio was 0.5482, corresponding to a central 95-percentile interval 0.08–11.87 of the likelihood ratio. The large difference between the intra- and interpersonal variation makes it unlikely that biological variation through pregnancy is a major contributor to the variation of risk estimates obtained several times in the same pregnancy. Rather, improvements in analytical quality and laboratory management must be expected to result in reduced variation and, in consequence, better performance of screening. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
403.
A research project was carried out to evaluate ecotoxicological effects of mature compost addition to agricultural soil, using a battery of ecotoxicological tests. The following species were selected: plant of Lepidium sativum, earthworm Eisenia foetida, aquatic crustacean Daphnia magna and bacteria Vibrio fischeri. The tests were classified as “direct tests” using solid compost samples and “indirect tests” using compost leaching test eluate. The direct bioassays were performed using compost added to artificial soil in concentrations ranging from 2.5 to 100 % (w/w); the indirect ones considered compost eluate, added to a standard solution in the same concentrations used in the direct tests. Both tests aimed at obtaining the ecotoxicological parameters (LC50 and EC50). These values were then utilized to implement the Species Sensitivity Distribution (SSD) analysis and extrapolate the Hazard Concentration (HC), a useful threshold to preserve the biodiversity of agricultural ecosystems. Results indicated an increase in compost toxicity with greater compost concentrations; in particular, for direct tests compost dosage below 10 % showed low toxicity, while for indirect ones the toxicity was higher. Furthermore, SSD analysis showed a Hazardous Concentration (HC5) for direct bioassays of 3.5 % and for indirect of 14 %.  相似文献   
404.
A recent study (Izzo et al., Behav Ecol Sociobiol 64: 857–864, 2010) reported that cuticular hydrocarbons (CHCs) correlate with fertility, not dominance, in the paper wasp Polistes dominulus thus contradicting the results of recent investigations which concluded that social dominance is the main determinant for CHC signatures in this species. We suggest here that different forms of dominance in the pre-nesting and post-nesting phases caused the apparently contradictory results. Thus the assumption that dominance behaviour in the pre-nesting stage is synonymous with dominance after colony foundation is incorrect. We provide standardised definitions for forms of “dominance” observed in the P. dominulus life cycle to avoid apparent discrepancies in the future among studies dealing with the same topics in different annual stages.  相似文献   
405.
406.
Sea ports and the related maritime activities (e.g. shipping, shipbuilding, etc.) are one of the main driver of Europe’s growth, jobs, competitiveness and prosperity. The continuously growth of shipping sectors has however introduced some environmental concerns, particularly with respect to ship-generated waste management. The port of Koper, one of the major ports on the northern Adriatic Coast, is the focus of this study. In this paper, a life cycle assessment was performed to identify and quantify the environmental impacts caused by the ship-generated waste management of port of Koper. Carcinogens substance (e.g. dioxins) and inorganic emissions, especially heavy metals, resulted to be the most critical environmental issues, while the fossil fuels consumption is reduced by recovery of ship-generated oils. Moreover, the final treatment of ship waste was found to be critical phase of the management, and the landfill have a significant contribute to the overall environmental load. These results can be useful in the identification of the best practices and in the implementation of waste management plans in ports.  相似文献   
407.
Urban air pollutant concentration data often tend to fit a two-parameter averaging-time model having three characteristics: (1) pollutant concentrations are (two-parameter) lognormally distributed for all averaging times; (2) median concentrations are proportional to averaging time raised to an exponent; and (3) maximum concentrations are approximately inversely proportional to averaging time raised to an exponent. Concentration data obtained near many isolated point sources and in some urban areas often do not fit a two-parameter lognormal distribution. An increment (either positive or negative) can be added to each such concentration in order to fit the data instead to a three-parameter lognormal distribution. This increment has been incorporated as the third parameter in a new three-parameter averaging-time model that can be used in both point-source and urban settings. Examples show how this new model can be used to analyze SO2 concentration data obtained near a point source to determine the degree of emission reduction needed to achieve the national ambient air quality standards.  相似文献   
408.
Abstract

Metabolites in which the chlorine from propachlor has been replaced by a cysteine group or a methylsulfonyl group [‐S(O2) CH3] are present in the urine of rats dosed orally with propachlor. In the present study, urine from rats given single oral doses of 35S‐labeled cysteine conjugate of propachlor contained metabolites having the methylsulfonyl groups labeled with S. No metabolites containing 14C‐labeled methylsulfonyl groups were isolated from urine of rats given single oral doses of the cysteine conjugate of propachlor in which the cysteine group was uniformly labeled with 14C. These findings show that the cysteine conjugate of propachlor is the source of sulfur in the methylsulfonyl‐containing metabolites. Therefore, we suggest that a C‐S lyase present in the animal cleaves the cysteine conjugate of propachlor and thus allows further metabolism of the sulfur to a methylsulfonyl moiety.  相似文献   
409.
An important component of the biological assessment of stream condition is an evaluation of the direct or indirect effects of human activities or disturbances. The concept of a "reference condition" is increasingly used to describe the standard or benchmark against which current condition is compared. Many individual nations, and the European Union as a whole, have codified the concept of reference condition in legislation aimed at protecting and improving the ecological condition of streams. However, the phrase "reference condition" has many meanings in a variety of contexts. One of the primary purposes of this paper is to bring some consistency to the use of the term. We argue the need for a "reference condition" term that is reserved for referring to the "naturalness" of the biota (structure and function) and that naturalness implies the absence of significant human disturbance or alteration. To avoid the confusion that arises when alternative definitions of reference condition are used, we propose that the original concept of reference condition be preserved in this modified form of the term: "reference condition for biological integrity," or RC(BI). We further urge that these specific terms be used to refer to the concepts and methods used in individual bioassessments to characterize the expected condition to which current conditions are compared: "minimally disturbed condition" (MDC); "historical condition" (HC); "least disturbed condition" (LDC); and "best attainable condition" (BAC). We argue that each of these concepts can be narrowly defined, and each implies specific methods for estimating expectations. We also describe current methods by which these expectations are estimated including: the reference-site approach (condition at minimally or least-disturbed sites); best professional judgment; interpretation of historical condition; extrapolation of empirical models; and evaluation of ambient distributions. Because different assumptions about what constitutes reference condition will have important effects on the final classification of streams into condition classes, we urge that bioassessments be consistent in describing the definitions and methods used to set expectations.  相似文献   
410.
To investigate the effects of moist olive husks (MOH-residues) on soil respiration, microbial biomass, and enzymatic (o-diphenoloxidase, beta-glucosidase, dehydrogenase and alkaline phosphatase) activities, a silty clay soil was incubated with 0 (control), 8 x 10(3) (D), 16 x 10(3) (2D) and 80 x 10(3) (10D) kg ha-1 of MOH-residues on a dry weight basis. Soil respiration and microbial biomass data indicated that the addition of MOH-residues strongly increased microbial activity proportionally to the amounts added. Data of qCO2 suggested that the respiration to biomass ratio of the microbial population was strongly modified by MOH-residues additions during the first 90 days of incubation. The qCO2 data suggested a low efficiency in energy yields from C oxidation during the first 2 months of soil incubation. qFDA seemed to be relatively unaffected for treatments D and 2D as compared to the control, but was significantly lowered by the application of 10D, showing the lowest hydrolytic activity of microbial biomass in this treatment up to 360 days of incubation. o-Diphenoloxidase activity was delayed, and this delay was extended with the addition of larger quantities of MOH-residues. Alkaline phosphatase, beta-glucosidase and dehydrogenase activities were in line with the findings on microbial biomass changes and activities. The biological and biochemical data suggest that the addition of a large quantity of MOH-residues (80 x 10(3) kg ha-1) strongly modifies the soil characteristics affecting the r- and K-strategist populations, and that these changes last for at least the 360 days of incubation. The data also suggest that application rates exceeding 16 x 10(3) kg ha-1 are not recommended until the agro-chemical and -physical functions of the soil are further studied.  相似文献   
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