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101.
Most major neuropsychiatric outcomes of concern to families are not detectable by prenatal ultrasound. The introduction of genome-wide chromosomal microarray analysis to prenatal clinical diagnostic testing has increased the detection of pathogenic 22q11.2 deletions, which cause the most common genomic disorder. The recent addition of this and other microdeletions to non-invasive prenatal screening methods using cell-free fetal DNA has further propelled interest in outcomes. Conditions associated with 22q11.2 deletions include intellect ranging from intellectual disability to average, schizophrenia and other treatable psychiatric conditions, epilepsy, and early-onset Parkinson's disease. However, there is currently no way to predict how severe the lifetime expression will be. Available evidence suggests no major role in these neuropsychiatric outcomes for the congenital cardiac or most other structural anomalies that may be detectable on ultrasound. This article provides an outline of the lifetime neuropsychiatric phenotype of 22q11.2 deletion syndrome that will be useful to clinicians involved in prenatal diagnosis and related genetic counselling. The focus is on information that will be most relevant to two common situations: detection of a 22q11.2 deletion in a fetus or newborn, and new diagnosis of 22q11.2 deletion syndrome in a parent without a previous molecular diagnosis. © 2016 John Wiley & Sons, Ltd.  相似文献   
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Previous studies on various marine mollusc species have shown that both larval and juvenile growth rates are substantially heritable, but few workers have examined the extent to which larval and juvenile growth rates covary. We examined the relationship between larval and juvenile growth rates in seven laboratory experiments conducted between 1986 and 1993, using the prosobranch gastropods Crepidula plana Say and C. fornicata (L.). In most experiments larvae were reared individually, measured twice nondestructively to determine larval grwoth rate, allowed or stimulated (daily 5-h exposure to 20 mM excess K+ in seawater) to metamophose, and then measured at least twice after metamorphosis to determine juvenile growth rates. Generally, there was no significant (p >0.10) relationship between larval and juvenile growth rates, suggesting that in these two species selection can act independently on the two stages of development. A positive correlation (p=0.007) between larval and juvenile growth rates was observed for C. fornicata in one experiment, but only for offspring from females maturing the most rapidly in laboratory culture. Even for these larvae, however, variation in larval growth rate explained<2% of the variation in juvenile growth rate, so that larval and juvenile growth rates are at most only weakly associated in this species.  相似文献   
104.
Recovery dynamics in a previously disturbed stream were investigated to determine the influence of a series of remedial actions on stream recovery and to evaluate the potential application of bioindicators as an environmental management tool. A suite of bioindicators, representing five different functional response groups, were measured annually for a sentinel fish species over a 15 year period during which a variety of remedial and pollution abatement actions were implemented. Trends in biochemical, physiological, condition, growth, bioenergetic, and nutritional responses demonstrated that the health status of a sentinel fish species in the disturbed stream approached that of fish in the reference stream by the end of the study. Two major remedial actions, dechlorination and water flow management, had large effects on stream recovery resulting in an improvement in the bioenergetic, disease, nutritional, and organ condition status of the sentinel fish species. A subset of bioindicators responded rather dramatically to temporal trends affecting all sites, but some indicators showed little response to disturbance or to restoration activities. In assessing recovery of aquatic systems, application of appropriate integrative structural indices along with a variety of sensitive functional bioindicators should be used to understand the mechanistic basis of stress and recovery and to reduce the risk of false positives. Understanding the mechanistic processes involved between stressors, stress responses of biota, and the recovery dynamics of aquatic systems reduces the uncertainty involved in environmental management and regulatory decisions resulting in an increased ability to predict the consequences of restoration and remedial actions for aquatic systems.  相似文献   
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Urban ecological systems: scientific foundations and a decade of progress   总被引:9,自引:0,他引:9  
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.  相似文献   
107.
Rapid infiltration basins (RIBs) are effective tools for wastewater treatment and groundwater recharge, but continuous application of wastewater can increase soil P concentrations and subsequently impact groundwater quality. The objectives of this study were to (1) investigate the effects of reclaimed water infiltration rate and "age" of RIBs on soil P concentrations at various depths, and (2) estimate the degree (percentage) of sorption equilibrium reached between effluent P and soil attained during reclaimed water application to different RIBs. The study was conducted in four contrasting cells of a RIB system with up to a 25 year history of secondary wastewater application. Soil samples were collected from 0 to 300 cm depth at 30 cm intervals and analyzed for water extractable phosphorus (WEP) and oxalate extractable P, Al, and Fe concentrations. Water extractable P and P saturation ratio (PSR) values were generally greater in the cells receiving reclaimed water compared to control soils, suggesting that reclaimed water P application can increase soil P concentrations and the risk of P movement to greater depths. Differences between treatment and control samples were more evident in cells with longer histories of reclaimed water application due to greater P loading. Data also indicated considerable spatial variability in WEP concentrations and PSR values, especially within cells from RIBs characterized by fast infiltration rates. This occurs because wastewater-P flows through surface soils much faster than the minimum time required for sorption equilibrium to occur. Studies should be conducted to investigate soil P saturation at deeper depths to assess possible groundwater contamination.  相似文献   
108.
Genetic mechanisms of pollution resistance in a marine invertebrate.   总被引:1,自引:0,他引:1  
Pollution is a common stress in the marine environment and one of today's most powerful agents of selection, yet we have little understanding of how anthropogenic toxicants influence mechanisms of adaptation in marine populations. Due to their life history strategies, marine invertebrates are unable to avoid stress and must adapt to variable environments. We examined the genetic basis of pollution resistance across multiple environments using the marine invertebrate, Styela plicata. Gametes were crossed in a quantitative genetic breeding design to enable partitioning of additive genetic variance across a concentration gradient of a common marine pollutant, copper. Hatching success was scored as a measure of stress resistance in copper concentrations of 0, 75, 150, and 350 microg/L. There was a significant genotype x environment interaction in hatching success across copper concentrations. Further analysis using factor analytic modeling confirmed a significant dimension of across-environment genetic variation where the genetic basis of resistance to stress in the first three environments differed from that in the environment of highest copper concentration. A second genetic dimension further differentiated between the genetic basis of resistance to low and high stress environments. These results suggest that marine organisms use different genetic mechanisms to adapt to different levels of pollution and that the level of genetic variation to adapt to intense pollution stresses may be limited.  相似文献   
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110.
This paper analyzes existing cost-sharing rules for wastewater pollution grants administered by the Environmental Protection Agency under the 1972 Amendments to the Federal Water Pollution Control Act. It identifies and measures biases in the existing cost-sharing rules that encourage nonfederal interests to select particular techniques (e.g., capital-intensive techniques) over others even when the selected techniques are not the least costly to the nation. The paper develops theoretically a cost-sharing condition—that the same percentage cost share be applied to all abatement techniques—that would eliminate the cost-sharing bias. Alternative cost-sharing approaches are evaluated in terms of their biasing effects and their absolute dollar costs for federal and nonfederal project participants.  相似文献   
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