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171.
The spontaneous resolution of cystic hygromas in fetuses with trisomy 18 may be due to a delay in lymphatic-vascular anastomosis. The severity of growth delay with trisomy 18 appears to be variable in time of onset and extent.  相似文献   
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ABSTRACT: The underwater light field of eight central New York lakes, which represent a wide range of trophic state, was characterized through paired measurements of Sechi disc transparency (SD, m) and diffuse light attenuation (Kd, m?1). A total of 90 paired measurements are included in the data base. Substantial variability in the Kd SD product with time within individual systems, and amongst systems, was observed, which indicates differences in the relative contributions of absorption and scattering to attenuation. More than 50 percent of the temporal variability in Kd was attributable to attendant variations in chlorophyll a (C, mg m?3) in only two of the lakes. Estimates of the adsorption (a, m?1) and scattering (b, m?1) coefficients based on paired Kd and SD measurements compared well with more precise determinations available for one of the lakes. Determinations of a and b for the eight lakes, from SD and Kd measurements, indicated great system-specificity and temporal variability in these characteristics. The temporal variability in relative contributions of a and b to Kd is consistent with covariation of different attenuating components and the lack of correlation between C and Kd in most of the study lakes.  相似文献   
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The Nickel Rim aquifer has been impacted for five decades by a metal-rich plume generated from the Nickel Rim mine tailings impoundment. Metals released by the oxidation of pyrrhotite in the unsaturated zone of the tailings migrate into the downgradient aquifer, affecting both the groundwater and the aquifer solids. A reactive barrier has been installed in the aquifer to remove sulfate and metals from the groundwater. The effect of the reactive barrier on metal concentrations in the aquifer solids has not previously been studied. In this study, a series of selective extraction procedures was applied to cores of aquifer sediment, to ascertain the distribution of metals among various solid phases present in the aquifer. Extraction results were combined with groundwater chemistry, geochemical modelling and solid-phase microanalyses, to assess the potential mobility of metals under changing geochemical conditions. Reactions within the reactive barrier caused an increase in the solid-phase carbonate content downgradient from the barrier. The concentrations of poorly crystalline, oxidized phases of Mn and Fe, as well as concentrations of Cr(III) associated with oxidized Fe, and poorly crystalline Zn, are lower downgradient from the barrier, whereas total solid-phase metal concentrations remain constant. Iron and Mn accumulate as oxidized, easily extractable forms in a peat layer overlying the aquifer. Although these oxides may buffer reducing plumes, they also have the potential to release metals to the groundwater, should a reduced condition be imposed on the aquifer by remedial actions.  相似文献   
176.
International trade is the primary conduit for unintentional and damaging species introductions. But biogeographic heterogeneity, and differences in historical trade exposure across trade partners suggest that not all imports are equally risky. We develop an analytical model linking exotic species introductions and discoveries to trade volumes. The model is estimated using a novel historical data set on global trade and species introductions by region. Our estimates support theoretical predictions that trade from different regions poses different risks and that the cumulative number of introductions from a region is a concave function of imports. For each trade region we then calculate the marginal and cumulative invasion risk from additional trade. Simple volume restrictions on imports to reduce NIS introductions are not advisable based on coarse cost–benefit calculations.  相似文献   
177.
ABSTRACT: Water resource and water quality management planning depend, to a large degree, on forecasts of industrial activity and population projections. A flexible economic data base is especially important where planning follows varying formats of geographical and industrial detail. Records of employment and payroll are collected in the administration of Unemployment Insurance (U.I.) programs and are available from State Employment Agencies. These statistics have been collected over a long period of record (thirty-five years). Many years of record are available on punched-cards or magnetic tape and may be arrayed and manipulated by computer. This basic approach has been followed in Virginia. Historical U.I. payroll and employment records for the period 1956 through 1970 were procured on magnetic tape. This data was arrayed by major hydrologic area and by regional planning district. Projections of manufacturing activity were then generated by fitting several exponential equations to annual payroll data in two-digit Standard Industrial Classifications. These exponentials were then extrapolated to provide a range of industrial projections. Other parameters of manufacturing activity were then correlated to the payroll data to generate projections of indexes such as employment, value-added, and gross manufacturing output. U.I. payroll data is now being correlated to parameters in non-manufacturing categories. Projections for industries such as trade and services will link extrapolated payroll data with benchmark correlations of payroll and sales receipts.  相似文献   
178.
The terrorist attacks of 11 September 2001 (9/11) left workplaces in pressing need of a mental health response capability. Unaddressed emotional sequelae may be devastating to the productivity and economic stability of a company's workforce. In the second year after the attacks, 85 employees of five highly affected agencies participated in 12 focus groups to discuss workplace mental health issues. Managers felt ill prepared to manage the magnitude and the intensity of employees' emotional responses. Rapid return to work, provision of workplace mental health services, and peer support were viewed as contributory to emotional recovery. Formal mental health services provided were perceived as insufficient. Drawing on their post‐9/11 workplace experience, members of these groups identified practical measures that they found helpful in promoting healing outside of professional mental health services. These measures, consistent with many principles of psychological first aid, may be applied by workplace leaders who are not mental health professionals.  相似文献   
179.
ABSTRACT

This article draws from the author’s four-year study of five school communities hit by the 2010–2011 earthquake sequence in the Canterbury region of New Zealand to highlight the roles that schools played in supporting their communities in the aftermath of the disaster. The article begins by synthesising the relevant literature on disasters, schools in earthquake disasters, and the importance of schools to their communities, pre- and post-disaster. The following themes from the data are discussed: (a) the role of schools in their communities prior to the earthquakes; (b) the role of schools in immediate rescue and response; (c) the role of schools in short-term relief; and (d) the role of schools in long-term recovery. The author then argues that as more evidence shows that schools play such crucial roles in post-disaster response and recovery, we need to better prepare and support them to undertake these functions. Further, we need to recognise the wider roles schools play supporting local communities to build and sustain resilience as part of on-going community cohesion and connectedness, so that society is better prepared when major disasters occur.  相似文献   
180.
Many environmental and facility managers view the submittal and public availability of their facilities' risk management plans (RMPs) as discrete events and give little thought about how RMP information may influence their future relations with plant communities and other stakeholders. In fact, the public availability of RMPs will have some significant and lasting consequences that have the potential to alter RMP sources' relations with a wide variety of stakeholders. This article is the first of two installments that will explore some of the likely outcomes of the risk management program, with a particular emphasis on those consequences tied to the public availability of the RMPs themselves. This installment considers likely responses at the community level and from both national and local environmental advocacy groups. The second installment will look at likely responses to RMP information in land use planning, by the financial services sector, by regulatory agencies, and by the senior management of RMP sources' owners and operators. Although the responses of individual communities to RMPs will be governed by a number of variables, including the nature of existing relations with individual RMP sources, proximity (or perceived proximity) of residences or other public and environmental receptors to RMP sources, and stakeholders' attitudes toward chemicals and chemical use, there are certain potential responses that managers should look for in their communities. These RMP-driven responses and expectations are discussed in the first installment of this article.© 1999 John Wiley & Sons, Inc.  相似文献   
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