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471.
Concentrations of thirty elements were measured in strong-acid extracts of soil, sagebrush (Artemisia tridentata spp.) leaves and perennial grass from the Idaho National Engineering Laboratory (INEL) and two reference sites in southern Idaho. A bicarbonate-chelating extract of soil was used to estimate plant-available concentrations. The results provide baseline data prior to start-up of a coal-fired steam generation facility on the INEL and other developments in the region. In addition, existing impact from effluents from thirty years of a nuclear fuel reprocessing facility on the INEL was evaluated. Based on the spatial distribution of element concentrations, as well as comparison with references sites, we conclude that concentrations of Zn, and perhaps Ni, Cd, and V, are currently elevated around the fuel reprocessing facility. The spatial distribution of these elements is similar to that of 137Cs in soil, a radionuclide which is emitted by the facility. Sagebrush and soil appear more responsive than perennial grass for long-term monitoring of element concentrations in this semi-arid environment.  相似文献   
472.
Prenatal diagnosis of trisomy 20 mosaicism in this case was based on cytogenetic analysis of cultured amniotic fluid cells (23/52 cells were trisomy 20 representing cells from each of four primary cultures). The pregnancy continued to term and the mosaicism was confirmed in the phenotypically normal male neonate by analysis of cultured foreskin fibroblasts (7/49 cells + 20) and placental cells 20/20 cells + 20) whereas the peripheral lymphocytes were cytogenetically normal (20/20 cells were 46,XY). This represents the first confirmation of trisomy 20 mosaicism in a phenotypically normal full-term neonate.  相似文献   
473.
This paper describes tools developed through a community consultative process to help decision makers manage electrical and magnetic fields (EMF) health risk. The process involved in‐depth interviews with experts (N=12) and focus group discussions with seven different stakeholder groups. The results reveal commonly held intense public concerns about the long‐term health effects of EMF. These concerns were further reinforced by the lack of public trust in both government and industry with regards to EMF risk management. Overall, the participants wanted tools that can be used to manage EMF information, scientific uncertainty about EMF and the complex environment in which EMF issues are embedded. The findings contributed to a mapping out of response formats to address public concerns related to risk, hazard, trust, accountability and fairness across a range of stakeholder groups. These tools and their roles in the management of complex and variable risks, involving new circumstances (e.g. privatization) and information (e.g. new scientific studies) are presented. The importance of recognizing and working with uncertainty through adaptive management strategies, using qualitative approaches, is also discussed.  相似文献   
474.
Summary Mass media can be used to reach a large audience, create knowledge and spread information, and lead to changes in attitudes. Newspapers, radio and television offer a valuable mechanism for parks and preserves to influence the public beyond their boundaries. With the park system in Sabah, Malaysia, a series of newspaper articles with the goal of increasing public interest in parks was developed. Although lack of prior data precluded an assessment of changes in park visitation rates, secondary effects such as calls from politicians and the business community, suggested tha print media is an effective way of reaching specific audiences with environmental messages in Sabah. Furthermore, the parks can serve a useful service by providing environmental information to the public. A survey of mass media in Sabah revealed a weekly average of only two newspaper articles and one hour of television viewing time devoted to natural resource conservation issues.Dr Susan K. Jacobson is Coordinator for the Program for Studies in Tropical Conservation in the Department of Wildlife and Range Sciences at the University of Florida. The paper describes research which she undertook in Sabah, Malaysia.  相似文献   
475.
Familial dysautonomia (FD), a recessively inherited disease, has been mapped to chromosome 9q31. Highly polymorphic dinucleotide repeat markers flanking the genetic locus and at the same genetic location have been identified. We describe the prenatal diagnosis of FD using linkage and linkage disequilibrium analyses with these markers. Twelve families were analysed for informativeness and of these, seven went on to have prenatal testing (a total of eight fetuses tested). All of these fetuses were predicted to be heterozygous unaffected (FD carriers). Seven fetuses have come to term and are normal. In the absence of a recombinant proband, a panel of three proximal and three distal markers is sufficient to provide informative flanking markers and an 87–96 per cent likelihood of a highly predictive test. In an additional family at 1:4 risk for FD, no DNA was available from the propositus. This family was analysed using linkage disequilibrium to the #18 allele of the tightly linked marker D9S58 in conjunction with linkage analysis using data from two unaffected children. Prenatal diagnosis in this family indicated an affected fetus.  相似文献   
476.
PROBLEM: The rapid growth of teleworking has raised several social and legal issues regarding an employer's responsibility for the safety of an employee's home office. In this paper, researchers discuss the need for safety training for teleworkers and the effectiveness of a home office ergonomics training program. METHOD: Study participants (N = 50) were randomly assigned into a treatment or control group. The treatment group completed the ergonomics training and a pre- and posttest. The control group completed the pre- and posttests without training. RESULTS: The study demonstrated the need for teleworker ergonomics training. More than 85% of participants had not received teleworker training before, and 44% had experienced pain or discomfort while teleworking. Participants who completed the training significantly improved their scores on knowledge, attitude, and practices subtests. In a follow-up survey, participants indicated that they had made ergonomic changes to their offices based on the training. Several participants indicated that the pain or discomfort that they had been experiencing was eliminated or reduced as a result of the training.  相似文献   
477.
Local authorities and transport planners need fast and straightforward tools to perform their preliminary air quality assessments. Such tools are required to provide an initial impression of the local air quality and to highlight areas requiring a more rigorous investigation. This paper presents a technique to develop such a tool, for performing an initial assessment of air quality due to traffic in an urban area. The technique combines an interaction matrix methodology as developed for rock engineering systems, with Geographical Information System (GIS) map overlaying. This interaction matrix methodology incorporates a total system approach, which identifies the main parameters and quantifies the interactions between them. Weighting values for these parameters are obtained either through parametric studies, using numerical modelling, or from engineering judgement. These weightings are applied to spatial datasets for a study area using a GIS. The GIS results are presented in the form of a vulnerability map, which highlights the areas susceptible to poor air quality. This visual interpretation of the results is ideal for local authorities, who have to report to a wide range of non-specialists in the field, for example, planners, councillors and the public. The vulnerability map compares favourably with pollutant concentration patterns, obtained from an advanced dispersion model.  相似文献   
478.
Deflector Designs for Fish Habitat Restoration   总被引:1,自引:0,他引:1  
Paired current deflectors are structures that are installed on each bank of a river to locally reduce the width of the channel, thereby creating flow acceleration and promoting scouring. These instream habitat structures have been used extensively in restoration projects to create pool habitat for fish, but there are many discrepancies in deflector design recommendations in terms of orientation, height, and length. Our objectives were to (1) examine how the angle, height, and length of paired deflectors affect scour hole dimensions and potential for bank erosion; and (2) test the applicability to paired deflectors of existing equations for scour hole depth and volume. Three deflector angles (45°, 90°, and 135°), two deflector heights (with flow under and over the deflector height), and two lengths (reducing the width by 25% and 50%) were investigated using uniform sand in a laboratory flume. Results showed a 26–30% smaller scour depth resulting from 45° deflectors than from 90° deflectors and a 5–10% smaller scour depth for 135° deflectors compared to 90° deflectors. The volume of scour and the potential for bank erosion were greater when flow was under the height of the deflectors rather than overtopping and when the length of deflector was increased. When flow was under the deflector height, 135° deflectors had the highest amount of bank erosion; whereas during overtopping flow conditions, 90° deflectors had the greatest bank erosion potential. Values predicted by the model of Kuhnle and others were closest to observed scour depth and volume measurements. The assumption that upstream-oriented deflectors always generate the largest scour should be revised.  相似文献   
479.
Transformation products of 2-benzoxazolinone (BOA) in soil   总被引:1,自引:0,他引:1  
Three degradation experiments were performed to examine the formation of transformation products from 2-benzoxazolinone (BOA) in different soil types and concentrations. In two experiments using BOA in low concentration (400 microgkg(-1)) only one unidentified transformation product was found, whereas in the degradation experiment in high concentration (400 mgkg(-1)) several metabolites occurred. Two of these metabolites, 2-amino-(3H)-phenoxazin-3-one (APO); and 2-acetylamino-(3H)-phenoxazin-3-one (AAPO) were synthesized to prove their identity. This is the first time that the successive formation of these types of compounds from BOA is shown in soil. A number of other APO related transformation products were detected and provisionally characterized. The formation of APO, which is a much more biologically active compound than BOA, and the concurrent formation of a number of other APO-related metabolites in soil underline the importance of performing transformation studies as part of the evaluation of the effect of allelochemicals on weeds and soil-borne diseases.  相似文献   
480.
Data from the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) indicate significant changes have occurred in precipitation chemistry and the chemical climate in the United States (US). A Seasonal Kendall Trend (SKT) analysis shows statistically significant increases in precipitation ammonium concentrations at 64% of 159 continental US NADP/NTN sites evaluated from Winter 1985 to Fall 2004 (Dec. 1984 – Nov. 2004). Sulfate decreases were widespread, with an SKT analysis indicating statistically significant decreases at 89% of sites evaluated. Ratios of chemical equivalent concentrations of ammonium to sulfate in precipitation have risen to the extent that ammonium now exceeds sulfate over more than half of the continental U.S. on a precipitation-weighted-mean annual basis. These trends in the concentrations of ammonium, sulfate, and other species have been accompanied by significant decreases in the frequency of acidic precipitation (pH < 5.0) in the last decade.  相似文献   
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