The use of storm water to enhance a coastal swamp

The purpose of this study was to quantify the potential of available storm water to mitigate the adverse impacts of impounded saline water within a 1,336-ha, forested coastal ecosystem. A site-specific hydrodynamic model was constructed to predict the spatial influence of reduced salinity resulting from the continuous discharge of storm water, at a volume of 2.83 cubic meters per second (cms), directly and indirectly into the study area. These results were then incorporated into the Wetlands Value Assessment (WVA) model to quantify wetland benefits to specific habitats.The results show that the discharge of 2.83 cms of storm water can significantly enhance wetland functions within the 1,336-ha coastal ecosystem. The most benefit occurs when the storm water is discharged directly into the swamp via dedicated channel or pipeline, in contrast to discharging into an existing bayou within the subbasin and directing flow into the adjacent wetlands. Utilizing the WVA methodology, direct discharge is predicted to result in a net wetland benefit of 725.97 Average Annual Habitat Units (AAHUs). This benefit is largely attributed to reductions in salinity and an improved water regime (mixing) within the declining baldcypress swamp.     

The Variable Effects of Family Background on the Timing of First Marriage: United States, 1969–1993

Longitudinal data from the Panel Study of Income Dynamics for a sample of 6570 women and men observed between 1969 and 1993 are used to examine historical changes and life-course variation in the effects of family background characteristics on the timing of first marriage. Discrete-time event history analyses reveal that the inverse effect of parental resources (family income and mother's education) on the timing of first marriage has both declined over time and weakens as children age. Historical declines in the effect of parental resources on first marriage timing appear to explain the divergence between Black and White marriage patterns over this period. In contrast, the inverse effect of experiencing a nonintact family structure during childhood on the timing of first marriage remains constant over both historical time and the life course. The implications of these findings for theories of demographic individuation and life-course perspectives are discussed.     

Raptor nesting locations along an urban density gradient in the Great Basin,USA

Raptors are the most prevalent group of urban apex predators, and the majority of raptor genera in North America have been recorded using urban areas. Prior research assessments along urban-wildland gradients show that urban habitat preference varies by raptor species and that raptor nesting preferences within urban settings may vary. Attempts to understand the intra- and inter-specific nesting patterns along an urban gradient would advance extant knowledge. Here we present the locations of individual nest sites of nine raptor species along an urban gradient in Reno-Sparks, NV. We developed an urban density model based on the number of residents, number of employees, and building footprints and number of floors for built structures within each land parcel at four spatial scales, representing nest site, macrohabitat, average nearest-nest, and landscape scales. Cooper’s Hawks (Accipiter cooperii), Sharp-shinned Hawks (Accipiter striatus), and Red-tailed Hawks (Buteo jamaicensis) nested across the widest range of the urban spectrum and closest to the urban core, whereas Golden Eagles (Aquila chrysaetos) and Swainson’s Hawks (Buteo swainsonii) nested on the urban fringe. Urban density for all nest locations was lowest at the nest-site scale, and the highest at the average nearest-nest and landscape scales. Raptors tended to occupy a wide range of the building-area density spectrum but not the building-height or employee density spectrums indicative of the attractiveness of suburban habitat.

     

Cognitive Self‐Regulation and Depression: Examining Academic Self‐Efficacy and Goal Characteristics in Youth of a Northern Plains Tribe

The relationship between cognitive self‐regulatory processes and depression was examined in American Indian adolescents from a Northern Plains tribe. Students completed measures of negative life events, self‐efficacy, goals, and depressive symptoms. Results indicated that academic self‐efficacy was strongly associated with depression. Academic self‐efficacy also correlated with intrinsically motivating goal representations, such that students who indicated high academic self‐efficacy had goals that were more important to them, goals they thought more about, and goals they viewed as wanted by the self instead of as imposed on by others. However, we did not find the hypothesized mediational model in which academic self‐efficacy influenced depression indirectly by influencing goal characteristics. Rather, this indirect model varied by grade, and differed from what we expected. Specifically, for older adolescents, higher levels of academic self‐efficacy predicted goals that were more likely to be identified as the adolescent's own, and in turn, these self‐ as opposed to other‐oriented goals predicted higher levels of depressive symptoms. Results are discussed as providing support for continued investigations into the role of specific cognitive self‐regulatory processes in youth adjustment.     

Geographic Mobility and Spatial Assimilation among U. S. Latino Immigrants1

Although the spatial assimilation of immigrants to the United States has important implications for social theory and social policy, few studies have explored the atterns and determinants of interneighborhood geographic mobility that lead to immigrants’residential proximity to the white, non‐Hispanic majority. We explore this issue by merging data from three different sources ‐ the Latino National Political Survey, the Panel Study of Income Dynamics, and tract‐level census data ‐ to begin unraveling causal relationships among indicators of socioeconomic, social, cultural, segmented, and spatial assimilation. Our longitudinal analysis of 700 Mexican, Puerto Rican, and Cuban immigrants followed from 1990 to 1995 finds broad support for hypotheses derived from the classical account of minority assimilation. High income, English language use, and embeddedness in Anglo social contexts increase Latino immigrants’geographic mobility into Anglo neighborhoods. U. S. citizenship and years spent in the United Stares are ppsidvely associated with geographic mobility into more Anglo neighbor oods, and coethnic contact is inversely associated with this form of mobility, but these associations operate largely through other redictors. Prior experiences of ethnic discrimination increase and residence in public housing decreases the likelihood that Latino immigrants will move from their origin neighborhoods, while residing in metropolitan areas with large Latino populations leads to geographic moves into “less Anglo” census tracts.     

Evaluation of the Physical Hazards Associated with Two Remedial Alternatives at a Superfund Site

This study presents an evaluation of the risks due to the physical hazards associated with two remedial alternatives for a former chemical manufacturing facility in New Jersey. Both the on-site and off-site risk of work-related fatalities during remedy implementation and the risks of accident or accident-related fatalities during the off-site transport of site-related materials were evaluated. The two remedial alternatives evaluated were on-site containment and excavation with off-site incineration. The risk of at least one fatality due to a work-related accident was estimated for on-site activities associated with each remedial alternative, and for off-site incineration. The risks of at least one accident and of one accident-related fatality were calculated with accident and fatality data from the U.S. Department of Transportation. In addition, the risk of at least one accident that might potentially affect a natural resource (e.g., river, lake, or national park) was evaluated. This evaluation indicates that the risk of a work-related fatality is over an order of magnitude higher, and the risk of an accident or accident-related fatality is over three orders of magnitude higher, for the excavation/off-site incineration remedial alternative than for the on-site containment alternative. Overall, this study indicates that the physical hazards associated with excavation and off-site incineration are much greater than those associated with on-site containment for this site. Therefore, if a choice between the two remedial alternatives were to be made based solely on physical hazards and accident risk, the on-site containment alternative would be more protective of human health and the environment than the excavation/off-site incineration alternative.     

REGULATORY UPDATES: ICH E14 draft consensus guideline on clinical evaluation of QT/QTc interval prolongation

ICH E14 calls for public comment by epidemiologists and statisticians on the practical implications of thresholds to be used for regulatory decision‐making. Readers involved in QT/QTc assessment in drug development and those with an interest in this area are encouraged to give the topic some thought and to be prepared to engage in public debate on the proposed ICH E14 guidance in late 2004 and early 2005. Copyright © 2004 John Wiley & Sons Ltd.