Impacts of Urbanization on Base Flow and Recharge Rates, Northeastern Illinois: Summary of Year 1 Activities

During year one of a two-year project to investigate the impacts of urbanization on base flow and ground-water recharge rates in northeastern Illinois, three gaged watersheds in urbanized areas of northeastern Illinois, and one watershed located in rural northwestern Illinois, have been selected for study. The gages have a common period of record extending from October 1952 through the present, a period during which the northeastern Illinois watersheds underwent substantial urbanization. Mean daily discharge data from the gages have been analyzed using an automated hydrograph separation technique, and monthly estimates of mean total discharge, base flow, and direct runoff have been calculated. Spearman rank correlation coefficients indicate a stronger correlation between precipitation and total discharge, base flow, and direct runoff in the northeastern Illinois watersheds than in the rural watershed. Smoothed time-series plots of total discharge, base flow, and direct runoff in the urban watersheds are less consistent with precipitation than similar plots constructed from the rural watershed data. The trends indicate that rates of direct runoff have overtaken rates of base flow in two of the three northeastern Illinois watersheds, but in one of these watersheds, this relationship probably reflects the cessation of effluent discharges to the stream. In general, double-mass curve analysis suggests that, relative to the rural watershed, base flow in the urban watersheds has proportionally decreased, and direct runoff has proportionally increased. The trends suggested by the smoothed time-series plots and the double-mass curves are consistent with a conceptual model of the northeastern Illinois watersheds in which sewering and impervious surfaces have reduced infiltration, and thence ground-water recharge and base flow, in the watersheds.Ope

Midwest Technology Assistance Center for Small Public Water Systems Final Report

The Midwest Technology Assistance Center (MTAC) was established October 1, 1998 to provide assistance to small public water systems throughout the Midwest via funding from the United States Environmental Protection Agency (USEPA) under section 1420(f) of the 1996 amendments to the Safe Drinking Water Act. This report summarizes progress made under USEPA Grant# 832591-01 for funds received in Federal Years (FY) 05 and 06. MTAC is a cooperative effort of the 10 states of the Midwest (congruent with USEPA regions 5 and 7), led by the Illinois State Water Survey and the University of Illinois. The director of their Water Resources Institute (WRI) coordinates the participation of each state in MTAC. Dr. Richard Warner (WRI director) and Kent Smothers were the principal investigators for this project. Kent Smothers serves as the managing director of the center, and is responsible for conducting routine activities with the advice and counsel of Dr. Richard Warner.published or submitted for publicationis peer reviewe

The Role of Work Pressure in IT Task Groups: Identifying Theoretical Constructs

This paper introduces the study of group work pressure (GWP) in information technology (IT) task groups. We theorize that GWP arises from demands and resources in group work and that high levels of GWP inhibit group performance. To identify the constructs of a new group task demands-resources (GTD-R) model, we solicit subjects’ descriptions of factors associated with high and low pressure group work situations they have experienced. We find that GWP is composed of characteristics of the task, group, environment, and individuals in the environment. Group characteristics include expertise of the group, group history, and degree of interpersonal conflicts. Individual characteristics include task motivation, personal expertise, and positive/negative consequences. Task complexity, time pressure, and external resources available to the group complete the model tasks. The findings extend prior demands-resources research, suggesting a research model for future study and practical mechanisms for reducing undesirable effects of GWP

Context Counts: Effects of Work versus Non-Work Context on Participants’ Perceptions of Fit in E-mail versus Face-to-Face Communication

There is a general need to understand better how context can affect evaluation, usage, and productivity of IT in research and practical settings. This paper investigates how perceived effectiveness of e-mail-style computer-mediated communication (CMC) differs between work and non-work contexts of use, and contrasts these differences with perceived effectiveness of face-to-face communication (FtFC). From the prior literature, we identified seven major activity domains that are prominent in CMC research. We developed a set of activity scales and corresponding measures of normative cognitive effort (NCE) for these domains and conducted an initial study to evaluate the overall instrument. In a second study, we measured perceived effectiveness of the communication mode within each activity domain among subjects who had communicated via e-mail and FtFC over a 15-week period. Some subjects communicated to support team-based software development (work context), and others communicated for personal interest (non-work context). We find communication technologies, activities, and contexts of use jointly determine perceived effectiveness; context influences perceived effectiveness primarily through interactions; and NCE successfully predicts perceived effectiveness based upon normative differences among activities. Our findings extend prior research in the area of task-technology fit to incorporate context effects, suggest that context is an important consideration in designing research, and introduce NCE as a method for predicting fit that can be applied even prior to system design. We conclude that the differential effects of work vs. non-work contexts are too large to be ignored, and we recommend an increased focus on context effects in CMC research and practice

Nighttime chemistry at a high altitude site above Hong Kong

Nighttime reactions of nitrogen oxides influence ozone, volatile organic compounds, and aerosol and are thus important to the understanding of regional air quality. Despite large emissions and rapid recent growth of nitrogen oxide concentrations, there are few studies of nighttime chemistry in China. Here we present measurements of nighttime nitrogen oxides, NO3 and N2O5, from a coastal mountaintop site in Hong Kong adjacent to the megacities of the Pearl River Delta region. This is the first study of nighttime chemistry from a site within the residual layer in China. Key findings include the following. First, highly concentrated urban NOx outflow from the Pearl River Delta region was sampled infrequently at night, with N2O5 mixing ratios up to 8 ppbv (1 min average) or 12 ppbv (1 s average) in nighttime aged air masses. Second, the average N2O5 uptake coefficient was determined from a best fit to the available steady state lifetime data as γ(N2O5) = 0.014 ± 0.007. Although this determination is uncertain due to the difficulty of separating N2O5 losses from those of NO3, this value is in the range of previous residual layer determinations of N2O5 uptake coefficients in polluted air in North America. Third, there was a significant contribution of biogenic hydrocarbons to NO3 loss inferred from canister samples taken during daytime. Finally, daytime N2O5 mixing ratios were in accord with their predicted photochemical steady state. Heterogeneous uptake of N2O5 in fog is determined to be an important production mechanism for soluble nitrate, even during daytime. Key Points Large (up to 12 ppbv N2O5) but infrequent nocturnal NOx outflow from the Pearl River Delta Average N2O5 uptake coefficients 0.014 ± 0.007, in line with residual layer measurements in the U.S. Daytime N2O5 follows predicted steady state but rapidly produces soluble nitrate in fog.Department of Civil and Environmental Engineerin

Allosteric modulation of beta1 integrin function induces lung repair in animal model of emphysema.

Emphysema is a progressive lung disease characterised by loss of lung parenchyma with associated functional changes including decreased tissue elastance. Here we report beta1 integrin is a novel target for tissue repair and regeneration in emphysema. We show a single dose of a monoclonal antibody against beta1 integrin induced both functional and structural reversal of elastase-induced lung injury in vivo, and we found that similar matrix remodelling changes occurred in human lung tissue. We also identified a potential mechanism of action as this allosteric modulation of beta1 integrin inhibited elastase-induced caspase activation, F-actin aggregate formation and changes in cellular ATP levels. This was accompanied by maintenance of beta1?integrin levels and inhibition of caveolin-1 phosphorylation. We propose that allosteric modulation of beta1 integrin-mediated mechanosensing prevents cell death associated with lung injury and progressive emphysema, thus allowing cells to survive and for repair and regeneration to ensue

Testing the Group Task Demands-Resources Model among IT Professionals

Demands and resources of the work experience have been shown to be important antecedents to development of job burnout and exhaustion among individual workers, and a recent line of research has applied the demands-resources perspective to model pressures that can arise in group work. We conducted a study of the group task demands-resources model to extend testing from information technology (IT) student group settings—where the model was developed—to the context of group work among IT professionals. We find that most antecedents in the model are predictive of group work pressure or task performance satisfaction, however, several important differences emerged in findings between prior tests with IT students and the IT professionals we surveyed in this study

Regional assessment of the ground-water resources in eastern Kankakee and northern Iroquois counties

"ISWS/RI-111."--Cover.Includes bibliographical references (p. 60-61).Enumeration continues through succeeding title