8,231 research outputs found

    Water Quality Trends across Select 319 Monitoring Sites in Northwest Arkansas

    Get PDF
    Northwest Arkansas contains two 319 priority watersheds that the Arkansas Natural Resources Commission has identified as being impacted by point source and nonpoint source pollution (i.e., phosphorus, nitrogen, and sediment). This project specifically focused on determining water quality trends at select sites within the Illinois River (HUC# 11110103) and Beaver Reservoir (HUC# 11010001) priority watersheds, including Ballard Creek, Osage Creek, Illinois River, White River, West Fork White River and the Kings River where sufficient constituent data were available. Water quality trends were analyzed using flow‐adjusted constituent concentrations of phosphorus, nitrogen, sediment, sulfate and chloride, and parametric and non‐parametric statistical techniques to determine if constituent concentrations were increasing, decreasing or not significantly changing over time. Overall, flow‐adjusted concentrations of phosphorus and sediment have been decreasing across these watersheds based upon both statistical approaches. The decrease in phosphorus was likely the most important observation, because most water quality concerns in this region have focused on elevated phosphorus concentrations in these transboundary watersheds. These trends can be used along with other watershed information to improve the knowledge of how past, current, and future management decisions have influenced the watershed

    Growth or decline in the Church of England during the decade of Evangelism: did the Churchmanship of the Bishop matter?

    Get PDF
    The Decade of Evangelism occupied the attention of the Church of England throughout the 1990s. The present study employs the statistics routinely published by the Church of England in order to assess two matters: the extent to which these statistics suggest that the 43 individual dioceses finished the decade in a stronger or weaker position than they had entered it and the extent to which, according to these statistics, the performance of dioceses led by bishops shaped in the Evangelical tradition differed from the performance of dioceses led by bishops shaped in the Catholic tradition. The data demonstrated that the majority of dioceses were performing less effectively at the end of the decade than at the beginning, in terms of a range of membership statistics, and that the rate of decline varied considerably from one diocese to another. The only exception to the trend was provided by the diocese of London, which experienced some growth. The data also demonstrated that little depended on the churchmanship of the diocesan bishop in shaping diocesan outcomes on the performance indicators employed in the study

    Constructing computer virus phylogenies

    Get PDF
    There has been much recent algorithmic work on the problem of reconstructing the evolutionary history of biological species. Computer virus specialists are interested in finding the evolutionary history of computer viruses - a virus is often written using code fragments from one or more other viruses, which are its immediate ancestors. A phylogeny for a collection of computer viruses is a directed acyclic graph whose nodes are the viruses and whose edges map ancestors to descendants and satisfy the property that each code fragment is "invented" only once. To provide a simple explanation for the data, we consider the problem of constructing such a phylogeny with a minimum number of edges. In general this optimization problem is NP-complete; some associated approximation problems are also hard, but others are easy. When tree solutions exist, they can be constructed and randomly sampled in polynomial time

    Social Dilemmas and Cooperation in Complex Networks

    Get PDF
    In this paper we extend the investigation of cooperation in some classical evolutionary games on populations were the network of interactions among individuals is of the scale-free type. We show that the update rule, the payoff computation and, to some extent the timing of the operations, have a marked influence on the transient dynamics and on the amount of cooperation that can be established at equilibrium. We also study the dynamical behavior of the populations and their evolutionary stability.Comment: 12 pages, 7 figures. to appea

    C-Terminal truncation of NR2A subunits impairs synaptic but not extrasynaptic localization of NMDA receptors

    Get PDF
    NMDA receptors interact via the extended intracellular C-terminal domain of the NR2 subunits with constituents of the postsynaptic density for purposes of retention, clustering, and functional regulation at central excitatory synapses. To examine the role of the C-terminal domain of NR2A in the synaptic localization and function of NR2A-containing NMDA receptors in hippocampal Schaffer collateral–CA1 pyramidal cell synapses, we analyzed mice which express NR2A only in its C-terminally truncated form. In CA1 cell somata, the levels, activation, and deactivation kinetics of extrasynaptic NMDA receptor channels were comparable in wild-type and mutant NR2A^(ΔC/ΔC) mice. At CA1 cell synapses, however, the truncated receptors were less concentrated than their full-length counterparts, as indicated by immunodetection in cultured neurons, synaptosomes, and postsynaptic densities. In the mutant, the NMDA component of evoked EPSCs was reduced in a developmentally progressing manner and was even more reduced in miniature EPSCs (mEPSCs) elicited by spontaneous glutamate release. Moreover, pharmacologically isolated NMDA currents evoked by synaptic stimulation had longer latencies and displayed slower rise and decay times, even in the presence of an NR2B-specific antagonist. These data strongly suggest that the C-terminal domain of NR2A subunits is important for the precise synaptic arrangement of NMDA receptors

    Effects of anti-resorptive agents on trabecular bone score (TBS) in older women

    Get PDF
    Summary: We evaluated the longitudinal effects of anti-resorptive agents (534 treated women vs. 1,150 untreated) on lumbar spine bone mineral density (BMD) and trabecular bone score (TBS). TBS was responsive to treatment in women over age 50. The treatment-related increase in TBS was less than the increase in BMD, which is consistent with bone texture preservation. Introduction: In addition to inducing an increase in BMD, anti-resorptive agents also help to preserve bone architecture. TBS, a new gray-level texture measurement, correlates with 3D parameters of bone micro-architecture independent of BMD. Our objective was to evaluate the longitudinal effects of anti-resorptive agents on lumbar spine BMD and TBS. Methods: Women (≄50years), from the BMD program database for the province of Manitoba, Canada, who had not received any anti-resorptive drug prior to their initial dual X-ray absorptiometry (DXA) exam were divided into two groups: untreated, those without any anti-resorptive drug over the course of follow-up, and treated, those with a non-estrogen anti-resorptive drug (86% bisphosphonates, 10% raloxifene, and 4% calcitonin). Lumbar spine TBS was calculated for each lumbar spine DXA examination. Changes in TBS and BMD between baseline and follow-up (mean follow-up 3.7years), expressed in percentage per year, were compared between the two groups. Results: A total of 1,150 untreated women and 534 treated women met the inclusion criteria. Only a weak correlation was seen between BMD and TBS in either group. Significant intergroup differences in BMD change and TBS change were observed over the course of follow-up (p < 0.001). Similar mean decreases in BMD and TBS (−0.36%/year and −0.31%/year, respectively) were seen for untreated subjects (both p < 0.001). Conversely, treated subjects exhibited a significant mean increase in BMD (+1.86%/year, p < 0.002) and TBS (+0.20%/year, p < 0.001). Conclusion: TBS is responsive to treatment with non-estrogen anti-resorptive drug therapy in women over age 50. The treatment-related increase in TBS is less than the increase in BMD, which is consistent with bone texture preservatio

    Client Participation: Central and Underinvestigated Elements of Intervention

    Get PDF
    Although client participation is central to psychosocial interventions, most investigations conceptualize and measure participation in rather crude ways. This review suggests that essential elements of treatment participation are largely unknown, links between participation and outcomes are not clear, and most investigations of influences on within-treatment variations in participation are based on outdated causal models. Drawing on literature on health and mental health care, this article develops a comprehensive conceptual model of treatment participation. It proposes an agenda for future research aimed at understanding participation phenomena in various contexts

    Client Participation: Central and Underinvestigated Elements of Intervention

    Get PDF
    Although client participation is central to psychosocial interventions, most investigations conceptualize and measure participation in rather crude ways. This review suggests that essential elements of treatment participation are largely unknown, links between participation and outcomes are not clear, and most investigations of influences on within-treatment variations in participation are based on outdated causal models. Drawing on literature on health and mental health care, this article develops a comprehensive conceptual model of treatment participation. It proposes an agenda for future research aimed at understanding participation phenomena in various contexts

    The Relationship Between Landing Mechanics and Injury Risk in Women\u27s Collegiate Soccer Players

    Get PDF
    Mechanical performance in landing related tasks has been suggested to be related to injury in athletic. PURPOSE: The purpose of this investigations was to assess relationships which may exist between performance in landing mechanics and injury rates throughout a women’s NCAA Division II Collegiate Soccer season. METHODS: Twenty-eight women (age 19.7±1.6 yrs, height 1.6±0.5 m, mass 63.4±7.9 kg) were assessed using the Landing Error Scoring System (LESS) test prior to a competitive season. Injury rates, types, and time lost from participation were tracked throughout the season. Injury information was coded and categorized each week in the following: acute vs. chronic; soft vs. hard tissue; upper vs. lower body; specific anatomical location; contact vs. non-contact; week of injury occurrence; practice days missed from injury; and games missed from injury. Association was measured via a Spearman\u27s rank correlation coefficient and a stepwise linear regression was performed for any variables which showed significant correlation to determine predictive relationships which may exist. The LESS test was evaluated independently by multiple raters and inter-rater reliability was high (ICC=0.824, 95% CI upper and lower = 0.917-0.657, p=0.001). Statistical significance was set a priori at p≀0.05. RESULTS: No significant correlations were determined between LESS test performance and injury and the LESS score did not add strength of association to any predictive variables. DISCUSSION: The main finding of this investigation is that performance on the LESS test did not show significant association with injury rates in women’s collegiate soccer players. LESS test performance has previously been suggested to be a valid and reliable clinical assessment tool, and claims have been made regarding its utility as a screening tool for identification of persons who may be at risk for subsequent injury. Landing mechanics may still be a valid predictor of injury risk. However, the results of our investigation do not support the use of the LESS test as a screening tool for injury risk in women’s collegiate soccer athletes
    • 

    corecore