There are now several well-documented psychological problems associated with prenatal testing programmes. These include poor understanding of tests undergone or declined, anxiety following false positive results, and false reassurance in those receiving negative test results. There is, as yet, little evidence concerning how to provide services to circumvent these. The focus of this review is upon just one of these problems: how best to inform women about prenatal testing and their reproductive options following the diagnosis of a fetal abnormality. Possible methods of improving informed decision-making either about whether to undergo testing or whether to terminate an affected pregnancy are described drawing upon research from antenatal and other health care areas. Future challenges for clinical practice and research in this area concern the range of conditions and predispositions for which prenatal testing with the option of termination should be offered. 相似文献
The frequency of mosaicism and pseudomosaicism in the prenatal diagnosis of cytogenetic disorders is reported, based on 3000 pregnancies studied in our laboratory. Diagnosis of true mosaicism was only made when an abnomality was detected in two or more independent cultures established from an amniotic fluid sample. On this basis, 0.37 per cent of all cases were diagnosed as true mosaics. 1.07 per cent of all cases had pseudomosaicism involving more than one cell from the same culture with an identical abnormality. 4.13 per cent of cases had a single abnormal cell with an extra chromosome, loss of a sex chromosome (or part of a sex chromosome), or translocation. Details of the outcome and follow-up of cases is given. Particularly problematical were cases where multiple cells from one culture contained an abnormality which could have been clinically significant. A crude estimate of the extent to which true mosaicism might currently be misinterpreted as pseudomosaicism or entirely missed has been made, based on data from the U.S. survey (Hsu and Perlis, in press). It was concluded that even when two, and if necessary a third culture is extensively analysed with an average of 24 cells per culture counted, at least 4.5 per cent of cases of true mosaicism may be completely missed and at least 7 per cent could be misdiagnosed as pseudomosaicism. There is an urgent need for improved laboratory techniques which allow growth of a greater number of cell colonies and therefore a more broadly based analysis. Detailed long term follow-up of prenatally diagnosed mosaics is also essential for assessing the clinical significance of the laboratory findings. 相似文献
The objective of this paper is to examine the mitigation of climate change using the Clean Development Mechanism (CDM) from the perspective of developing countries. The effects of the CDM on developing countries’ efforts to reduce greenhouse gases (GHGs) pledged under the Paris Agreement (United Nations Framework Convention on Climate Change [UNFCCC], 21st Conference of the Parties, Paris, France) are investigated. Data analysis reveals that the intensive hosting of CDM projects and the resultant higher marginal abatement costs led to fewer efforts by developing countries to mitigate climate change. A theoretical model from the literature of “low-hanging fruits” is applied to determine if rising prices of the CDM can be expected in the future. The results indicate that the benefits for developing countries must increase so as to keep the CDM attractive for them in an environment where they also have reduction commitments. To further ensure the effectiveness of the CDM under the Paris Agreement, policy should ensure that developing countries actually charge higher prices and, at the same time, contribute adequately to the global goal of GHG reductions. To this end, developing countries should be permitted to demand benefits that lie outside the current scope of the CDM, and non-compliance with their climate targets should also be sanctioned. In addition, fostering sustainable development should become more attractive for developed countries without the CDM, e.g., through sustainability labels, so as to reduce the trade-off for developing countries between the benefits of the CDM and compliance with their commitments to mitigate climate change.
This paper examines some of the theoretical and methodological issues arising from the process of conceptualising and eliciting values for environmental risk in the context of heterogeneous expert knowledge. Drawing on the experience of a recent research project examining the relationship between livestock farming systems and microbial watercourse pollution the paper reflects critically upon efforts to develop an interdisciplinary assessment of the factors that may affect the loss of potential pathogens from agricultural land to water courses as the basis for targeting high risk fields and farms. The paper describes the procedures for designing the natural and cultural parameters that surround microbial risks and the issues that are raised for making whole system assessments workable based on contrasting and unstable systems of disciplinary insight. Situated within claims about the need for generating reliable and widely applicable assessments of environmental risk the paper suggests that interdisciplinary working raises important issues about the role of ‘uncertain’ knowledge in the management of ‘known’ risks. 相似文献
This paper positions climate change against the backdrop of gender, premised on the understanding that neither climate change impacts nor responses are gender neutral, therefore institutions need to respond accordingly. Institutions play a central role in facilitating policy effects and forming major nodes of interaction as well as determining the accentuation of risk. Drawing on examples from different parts of Sub-Saharan Africa, the paper seeks to elucidate why women should be placed at the heart of climate change interventions. Establishing the appropriate connections between gender and climate change will enhance the opportunities for problem-solving and can increase the efficiency and effectiveness of policy-making. The gendered aspects of climate change and environmental relations are analysed by using an African feminist approach as the theoretical framework to expand and expound upon this position. This paper also investigates institutional matters pertaining to the management of environmental resources and highlights some of the constraints that need to be overcome in order to ensure the inclusion and empowerment of women in the management of these resources. It concludes by calling for a thorough understanding of the gender-based power relations in the agendas and activities of environmental governance institutions at all levels in society. 相似文献
Abstract Reformulated gasoline (RFG) contains oxygen additives such as methyl tertiary butyl ether or ethanol. The additives enable vehicles to burn fuel with a higher air/fuel ratio, thereby lowering the emission of carbon monoxide (CO) and volatile organic compounds (VOCs). Because VOCs react with sunlight to form ozone (O3), the Clean Air Act requires severe O3 nonattainment areas such as southeastern Wisconsin to use RFG. On July 17, 2001, the U.S. Environmental Protection Agency (EPA) granted Milwaukee, WI, and Chicago, IL, a waiver from the VOC reduction requirement of Phase II RFG. The VOC reduction requirement was lowered from 27.4% of the 1990 baseline fuel to 25.4%. The assumption was that ethanol-blended RFG would lower summertime CO concentrations sufficiently to offset the increased VOC emissions. The waiver is estimated to increase VOC emissions by ~0.8%, or 0.4 t of VOC on a hot summer weekday. This study evaluates whether RFG has been effective in lowering southeastern Wisconsin ambient CO concentrations. Three years of ambient CO data before RFG was introduced were compared with the first three years of ambient CO data after RFG was introduced. This paper also evaluates how the meteorology, vehicle inspection/maintenance program, vehicle miles traveled, and stationary source emissions influence CO concentrations. The winter decrease in ambient CO concentrations was found to be statistically significant, while the summer data showed no statistically significant change, indicating that RFG is most effective lowering ambient CO concentrations in cold weather. 相似文献
Abstract: Roots of riparian vegetation increase streambank erosion resistance and structural stability; therefore, knowledge of root density and distribution in streambanks is useful for stream management and restoration. The objective of this study was to compare streambank root distributions for herbaceous and woody vegetation and to develop empirical models to predict root density. Root length density, root volume ratio, soil physical and chemical properties, and above‐ground vegetation densities were measured at 25 sites on six streams in southwestern Virginia. The Mann‐Whitney test was used to determine differences in root density along stream segments dominated by either woody or herbaceous vegetation. Multiple linear regression was used to develop relationships between root density and site characteristics. Study results showed that roots were evenly distributed across the bank face with the majority of roots having diameters less than 2 mm. Soil bulk density and above‐ground vegetation were key factors influencing root density. While significant relationships were developed to predict root density, the predictive capabilities of the equations was low. Because of the highly variable nature of soil and vegetation properties, it is recommended at this time that soil erodibility and root density be measured in the field for design and modeling purposes, rather than estimated based on empirical relationships. 相似文献
The study investigated factors associated with internalising emotional and behavioural problems among adolescents displaced during the most recent Chechen conflict. A cross-sectional survey (N=183) examined relationships between social support and connectedness with family, peers and community in relation to internalising problems. Levels of internalising were higher in displaced Chechen youth compared to published norms among non-referred youth in the United States and among Russian children not affected by conflict. Girls demonstrated higher problem scores compared to boys. Significant inverse correlations were observed between family, peer and community connectedness and internalising problems. In multivariate analyses, family connectedness was indicated as a significant predictor of internalising problems, independent of age, gender, housing status and other forms of support evaluated. Sub-analyses by gender indicated stronger protective relationships between family connectedness and internalising problems in boys. Results indicate that family connectedness is an important protective factor requiring further exploration by gender in war-affected adolescents. 相似文献
We combined a natural experiment with field surveys and GIS to investigate the effects of dust from recreational trails and
access roads on the federally threatened Valley elderberry longhorn beetle (“VELB,” Desmocerus californicus dimorphus) and its host plant, elderberry (Sambucus mexicana). Dust is listed in the species recovery plan as a threat to the VELB and unpaved surfaces are common throughout the riparian
corridors where the VELB lives, yet the effects of dust on the VELB have been untested. We found that dust deposition varied
among sites and was highest within 10 m of trails and roads, but was similar adjacent to dirt and paved surfaces within sites.
Elderberry density did not differ with distance from dirt surfaces. Despite similar within-site dust levels, elderberry adjacent
to paved surfaces were less stressed than those near dirt ones, possibly because increased runoff from paved surfaces benefited
elderberry. Dust deposition across sites was weakly correlated with elderberry stress symptoms (e.g., water stress, dead stems,
smaller leaves), indicating that ambient dust (or unmeasured correlates) influenced elderberry. Direct studies of the VELB
showed that its distribution was not negatively affected by the proximity to dirt surfaces. Dust from low traffic dirt and
paved access roads and trails, therefore, affected VELB presence neither directly nor indirectly through changed elderberry
condition. These results suggest that the placement of VELB mitigation, restoration, and conservation areas can proceed independently
of access roads if dust and traffic levels do not exceed those in our study site. Furthermore, dust control measures are likely
to be unnecessary under such conditions. The potential effects of increased traffic and dust levels are addressed through
a literature review. 相似文献