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101.
Because watershed collaborations connect economic and environmental concerns, they are of interest to students of sustainable economic development. The economic outcomes of such collaborations are difficult to study because socio-economic data collection areas do not generally correspond to collaboration boundaries and also because of the simultaneity of economic stimuli and restrictions in collaborative arrangements. This case study of New York City’s Watershed Collaboration in its Catskill Delaware Watershed used a mapping program to create a database of Watershed residents from the 1990 and 2000 census. It provides a heretofore unavailable socioeconomic portrait of the Watershed and trends in indicators relevant to Collaboration effectiveness such as age, demographic pressures, and economic welfare. Through the use of national, state, regional and rural controls, the study also explores the impact of the agreement on the Watershed. Results do not provide evidence of a net negative impact and are consistent with a net positive impact. Several trends which work against agreement effectiveness are identified.  相似文献   
102.
103.
Abstract: In 2006, we collected flow, sediment, and phosphorus (P) data at stream locations upstream and downstream of a small degraded wetland in south‐central Wisconsin traversed by a stream draining a predominantly agricultural watershed. The amount of sediment that left the wetland in the two largest storms, which accounted for 96% of the exported sediment during the observation period, was twice the amount that entered the wetland, even though only 50% of the wetland had been inundated. This apparently anomalous result is due to erosion of sediment that had accumulated in the low‐gradient channel and to the role of drainage ditches, which trapped sediment during the wetland‐filling phase. In the case of total P, the inflow to the wetland approximately equaled the outflow, although the wetland sequestered 30% of the incoming dissolved reactive P. The discrepancy is almost certainly due to net export of sediment. Many wetlands in the glaciated midwestern United States are ditched and traversed by low‐gradient channels draining predominantly agricultural areas, so the processes observed in this wetland are likely to be common in that region. Knowledge of this behavior presents opportunities to improve water quality in this and similar regions.  相似文献   
104.
ABSTRACT: Four algicides (copper citrate, copper ethanolamine, simazine, and diuron) were tested for effectiveness using in situ bio-assays. Bioassays were conducted in clear polyethylene bags and algicide effectiveness measured by chlorophyll a, productivity, and algal counts. The body of water where this testing took place had a high pH (9.2), and high levels of total dissolved solids (610 mg/l) and nutrients. The order of effectiveness found in this study was simazine > diuron > copper ethanolamine > copper citrate.  相似文献   
105.
Beach erosion on Cinnamon Bay in the U.S. Virgin Islands results from storm waves in the North Atlantic. The net trend of erosion, however, is due to local environmental degradation. Reef die-back, initiated during the period of high sedimentation associated with 18th and 19th century sugar cane cropping, has reduced the rate of generation of new coral sands. Sand losses to deep water during periods of storm waves are not replenished. Engineering measures designed to check erosion at Cinnamon Bay have had little effect in this environment of low wave energies, but sand deficiency. The appropriate environmental focus for management of reef-beach systems is reef health and thus, water quality.  相似文献   
106.
Northern fulmars from two breeding colonies in the Canadian Arctic, Cape Vera and Prince Leopold Island, were analyzed for organochlorine pesticides, PCBs, perfluorinated compounds (PFCs) and total mercury (Hg). Hepatic concentrations of organochlorines and Hg were highest in the male fulmars from Cape Vera. Perfluorooctane sulfonate (PFOS) concentrations did not vary significantly between sexes or colonies. However, concentrations of the perfluorinated carboxylates (PFCAs) were higher in fulmars from Cape Vera than Prince Leopold Island. The C11-C15 PFCAs averaged 90% of the PFCA profile at both colonies. Polychorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs (NO-PCBs) were measured only in birds from Prince Leopold Island. Concentrations of PCDDs, PCDFs, NO-PCBs and Toxic Equivalents (TEQs) did not differ significantly between sexes. ΣTEQ was comprised mainly of ΣTEQPCDF. Concentrations of Hg and the persistent halogenated compounds reported in this study were below published toxicological threshold values for wild birds.  相似文献   
107.
Elevated mercury concentrations in water were reported in the prairie wetlands at Lostwood National Wildlife Refuge, ND. In order to determine whether wildlife associated with these wetlands was exposed to and then accumulated higher mercury concentrations than wildlife living near more permanent wetlands (e.g. lakes), tree swallow (Tachycineta bicolor) eggs and nestlings were collected from nests near seasonal wetlands, semi-permanent wetlands, and lakes. Mercury concentrations in eggs collected near seasonal wetlands were higher than those collected near semi-permanent wetlands or lakes. In contrast, mercury concentrations in nestling livers did not differ among wetland types. Mercury and other element concentrations in tree swallow eggs and nestlings collected from all wetlands were low. As suspected from these low concentrations, mercury concentrations in sample eggs were not a significant factor explaining the hatching success of the remaining eggs in each clutch.  相似文献   
108.

Background

Disease severity is important when considering genes for inclusion on reproductive expanded carrier screening (ECS) panels. We applied a validated and previously published algorithm that classifies diseases into four severity categories (mild, moderate, severe, and profound) to 176 genes screened by ECS. Disease traits defining severity categories in the algorithm were then mapped to four severity-related ECS panel design criteria cited by the American College of Obstetricians and Gynecologists (ACOG).

Methods

Eight genetic counselors (GCs) and four medical geneticists (MDs) applied the severity algorithm to subsets of 176 genes. MDs and GCs then determined by group consensus how each of these disease traits mapped to ACOG severity criteria, enabling determination of the number of ACOG severity criteria met by each gene.

Results

Upon consensus GC and MD application of the severity algorithm, 68 (39%) genes were classified as profound, 71 (40%) as severe, 36 (20%) as moderate, and one (1%) as mild. After mapping of disease traits to ACOG severity criteria, 170 out of 176 genes (96.6%) were found to meet at least one of the four criteria, 129 genes (73.3%) met at least two, 73 genes (41.5%) met at least three, and 17 genes (9.7%) met all four.

Conclusion

This study classified the severity of a large set of Mendelian genes by collaborative clinical expert application of a trait-based algorithm. Further, it operationalized difficult to interpret ACOG severity criteria via mapping of disease traits, thereby promoting consistency of ACOG criteria interpretation.
  相似文献   
109.
An evaluation of the imprecision in dose predictions has been performed using current dose assessment models and present knowledge of the variability or uncertainty in model parameter values. The propagation of parameter uncertainties is demonstrated using a Monte Carlo technique for elemental 131I transported via the pasture-cow-milk-child pathway. The results indicate that when site-specific information is not available the imprecision inherent in the predictions for this pathway is potentially large. Generally, the 99th percentile in thyroid dose for children was predicted to be approximately an order of magnitude greater than the median value. The potential consequences of the imprecision in dose for radiation protection purposes are discussed.  相似文献   
110.
The U.S. Army Corps of Engineers conducted a water drawdown on Navigation Pool 8 of the Upper Mississippi River during the summers of 2001 and 2002 to increase aquatic vegetation production and thereby improve fish and wildlife habitat. Flooding of previously dried wetlands, however, may increase the rate of mercury methylation and make mercury more available to terrestrial vertebrates that feed in aquatic environments. Our objective was to determine if mercury, other elements, and organochlorine contaminants were more available to vertebrates following the 2001 drawdown. Tree swallow (Tachycineta bicolor) eggs and nestlings were collected at two sites on Pool 8 and a nearby Reference site in 2000 (pre-2001 drawdown), 2001 (pre-2001 drawdown) and 2002 (post-2001 drawdown) and tissues were analyzed for mercury, other elements, and organochlorine contaminants. Bioindicator measurements of genetic damage, oxidative stress, ethoxyresorufin-O-dealkylase activity, and the ratio of liver to nestling mass were also measured in nestlings at all sites and all years. Based on a multivariate analysis, the 2001 drawdown of Pool 8 did not influence element concentrations, organochlorine concentrations, or bioindicator response. Concentrations of inorganic and organochlorine contaminants in tree swallow eggs and nestlings were not at toxic levels. Hatching success did not differ among years and was comparable to the nationwide average.  相似文献   
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