Hierarchical Regulation of Nitrogen Export from Urban Catchments: Interactions of Storms and Landscapes

In urban catchments of arid central Arizona, we investigate how the export of mineral and organic nitrogen (N) in storm runoff is regulated by interactions between local landscape characteristics and broader scale storm features. First, we test whether N export is more a function of (1) processes that affect N concentration in runoff or (2) the propensity of the catchment to convey rainfall as runoff. With data pooled across catchments, the mass of N in export (load) is determined by processes regulating runoff N concentration. There are exceptions when catchments are examined individually, where N load from some catchments is determined by the hydrologic responsiveness of the catchment. Second, we investigate the relationship between N export and catchment features. Loads per catchment area were greater from more impervious catchments, probably because impervious catchments held more N in a mobilizable phase and conveyed more rainfall as overland flow. Loads per area were lower from larger catchments, possibly owing to more N-retention hot spots in larger catchments. Catchments with the greatest N exports were those with commercial land use, and loads decreased as development became less prevalent or as residential replaced industrial land use. Third, we investigated how catchment features moderated direct responses of N export to storms. Export was less correlated with storm features in catchments that were larger, more pervious, and less industrial. Results support an N build and flush hypothesis, which purports that there is little biotic processing of N deposited to arid, urban surfaces with little organic matter. The rate and duration of deposition determine the size of the mobile N pool. Any amount of rainfall capable of generating overland flow would entrain nearly all mobilizable N and export it from the catchment. Nonetheless, these results suggest that, even with daunting seasonal and interannual variability in storm conditions, material export can be reduced by managing intrinsic catchment features

ADDRESS (ADministration of DRotrecogin alfa [activated] in Early stage Severe Sepsis) long-term follow-up: one-year safety and efficacy evaluation.

OBJECTIVE: To demonstrate that drotrecogin alfa (activated) has an acceptable safety profile 1 yr from randomization. DESIGN: One-year follow-up of patients participating in a placebo-controlled clinical study of drotrecogin alfa (activated) in severe sepsis patients at low risk of death (the ADDRESS study). SETTING: The study was conducted at 516 hospitals in 34 countries. PATIENTS: The study included 2,640 patients. INTERVENTIONS: One-year follow-up was performed as an addendum to the placebo-controlled ADDRESS study. Treatment groups were compared using the chi-square test and Kaplan-Meier estimates. MEASUREMENTS AND MAIN RESULTS: Survival status at 1 yr was obtained for 90% of patients enrolled in the study (n = 2,376). The difference in mortality rate between drotrecogin alfa (activated) and placebo patients was numerically smaller at 1 yr (34.2% and 34.0%, respectively, p = .94) than at 28 days (18.5% and 17.0%, respectively, p = .34). In the subgroups defined by organ dysfunction class (single or multiple) and Acute Physiology and Chronic Health Evaluation II score (or=25), the differences in mortality rate between treatment groups at 1 yr were consistent with those observed at 28 days; no significant differences in mortality rates between treatment groups were observed. No additional serious adverse events were reported during the period between hospital discharge and 1 yr. CONCLUSIONS: No increased risk of death or evidence of harm at 1 yr was associated with drotrecogin alfa (activated) administration in patients with severe sepsis at lower risk of death

How to last alone at the top : US strategic planning for the unipolar era

This article investigates how key actors within the US defence policy community realigned their interests to forge a new consensus on the redirection of US defence strategy following the 'peace shock' they faced with the collapse of bipolarity. This consensus centred on the idea that achieving US security in the 'age of uncertainty' demanded overwhelming US military power, which was widely interpreted as necessitating military capabilities to fight multiple major theatre wars simultaneously against regional 'Third World' adversaries. This helped to preserve many of the principal pillars of US Cold War defence policy through deflecting calls for more radical organisational changes and deeper cuts to defence budgets

Orientation vs. Behavior: Gender Differences in Field of Study Choice Set

Women now surpass men in overall rates of college graduation in many industrialized countries, but sex segregation in fields of study persists, even within STEM majors. In a world where gender norms have changed but gender stereotypes remain strong, we argue that attitudes and orientation towards behaviors are less constrained by gendered institutions than are the behaviors themselves. Accordingly, sex segregation in the broader choice set of majors considered by student applicants may be lower than the sex segregation in their first preference field of study selection (first choice). Over time, this may lead to diminishing sex segregation in higher education and the labor market. With unique data on the broader set of fields considered by STEM-bound applicants to elite Israeli universities, we find support for this theory. Moreover, the factors that drive the gender gap in the first choice, in particular labor market earnings, risk aversion and the sex composition of fields! , are weaker in the broad set of choices than in the first choice. The result is less segregation in considered majors than in the first choice. We consider the theoretical implications of these results