Service-Learning: Going Beyond Traditional Extension Activities

This article advocates service-learning as an integrative strategy for Cooperative Extension Educators to advance the concept of a truly engaged institution through the use of college students. The authors, having designed and implemented a service-learning course, discuss the advantages of experiential education and its positive impact on the university, students, communities, and the Cooperative Extension Service

Developmental trends in voice onset time: some evidence for sex differences

This study reports on an investigation into the voice onset time (VOT) patterns of the plosives /p b t d/ in a group of 30 children aged 7 (n = 10), 9 (n = 10) and 11 (n = 10) years. Equal numbers of girls and boys participated in the study. Each child named a series of letter objects to elicit /p b t d/ in a syllable onset position with a fixed vowel context. VOT data were examined for age, sex and plosive differences with the following hypotheses: Firstly, that there would be sex differences in the VOT patterns of preadolescent children. Secondly, that the sex differences in VOT patterns would be linked to age and development, and that these would eventually become marked by the age of 11 years, by which time adult-like VOT values should have been achieved. Finally, that the extent of sex and age differences would be dependent upon the plosive being investigated. Results indicated patterns of decrease with age in the VOT values of /p b/ for the boys, with some evidence of increases in the VOT values of /t/ for the girls. In addition, 'voiced' and 'voiceless' cognates showed a more marked bimodal distribution in the girls' VOT patterns. This bimodal distribution was investigated by examining the degree of difference between the VOT values of voiced and voiceless cognate pairs /p b/ and /t d/, and examining the effects of age, sex and cognate pair. These results indicated that more marked sex differences in the 'voiced'/'voiceless' contrast emerged between the data of the 9- and 11-year-olds, a pattern, which was more marked for the alveolar plosives. These preliminary results confirmed all three hypotheses. The findings are presented and discussed both within a developmental and sociophonetic framework

NASA CYGNSS Mission Applications Workshop

NASA's Cyclone Global Navigation Satellite System, (CYGNSS), mission is a constellation of eight microsatellites that will measure surface winds in and near the inner cores of hurricanes, including regions beneath the eyewall and intense inner rainbands that could not previously be measured from space. The CYGNSS-measured wind fields, when combined with precipitation fields (e.g., produced by the Global Precipitation Measurement [GPM] core satellite and its constellation of precipitation imagers), will provide coupled observations of moist atmospheric thermodynamics and ocean surface response, enabling new insights into hurricane inner core dynamics and energetics. The outcomes of this workshop, which are detailed in this report, comprise two primary elements: (1) A report of workshop proceedings, and; (2) Detailed Applications Traceability Matrices with requirements and operational considerations to serve broadly for development of value-added tools, applications, and products

923-3 Fluosol Reduces Myocardial Reperfusion Injury by Prolonged Suppression of Neutrophils by its Detergent Component (RheothRx) and not by Enhancing O2Delivery

Fluosol, a complex mixture of O2carrying perfluorocarbons (PFCs) emulsified by the detergent pluronic F-68 and a variety of lipids, significantly reduces myocardial reperfusion injury (RI) in animals and humans as shown in some initial clinical trials. Potential mechanisms for Fluosol include enhanced O2delivery to the reperfused tissue and modulation of various neutrophil (PMNs) functions. Recent studies in dogs and man demonstrate the same beneficial effect for treatment of Rl with the detergent component alone, RheothRx, which is currently undergoing clinical trials. We have shown that the effect of Fluosol on PMNs is related to this detergent. However, prolonged infusion (48 hrs) of detergent is required to reduce Rl to the same extent as Fluosol given over only 1 hr. Possible mechanisms for the beneficial effects of Fluosol (O2delivery vs effects on PMNs) were investigated in a model of regional ischemia utilizing rabbits undergoing 30mins of circumflex occlusion and 48 hrs of reperfusion. Infarct size (area of necrosis, AN) was determined histologically and expressed as percent of risk region (area at risk, AR). Animals received Fluosol (30cc/kg) with or without O2or saline over the first 60mins of reperfusion. AR was similar in all groups. (Mean±SEM of AN/AR (%), n=11 for all groups). The treatment with Fluosol with or without O2(44±3 and 40;±3, respectively) was significantly (p<0.05) reduced compared to control (63±4). Another group received F-I08, a larger size pluronic detergent found to be 2.5-fold more potent in suppressing PMN function in vitrocompared to F-68, during the first 3 hrs of reperfusion. This treatment did not alter the infarct size (63±5). RheothRx was found to form 4 nm micelles in solution whereas Fluosol formed particles approximately 100 times larger. Similar sized particles were formed by substituting the perfluorocarbons with mineral oil. The in vitroactivity of this pluronic/mineral oil micelle on PMN function was similar to Fluosol. Infusion of these larger oil micelles was tolerated by rabbits and used in further infarct studies.ConclusionsThese studies suggest that (1) reduction of RI by Fluosol is not due to enhanced O2delivery by the PFCs to reperfused myocardium and (2) since the Fluosol emulsion markedly reduces the clearance of the detergent F-68 (t½: Fluosol ≅ 8 hrs vs RheothRx ≅ 1.5 hrs). prolonged PMN suppression rather than potency of suppression is the mechanism whereby Fluosol ameliorates RI. Fluosol's clinical efficacy may be enhanced by prolonging its infusion to ensure an adequate blood level to suppress PMN function beyond the time of reperfusion injury. RheothRx's clinical usefulness may be facilitated by decreasing its renal clearance by delivering larger micelles of the detergent in order to produce prolonged PMN suppression with a shorter infusion time

Rate-dependent propagation of cardiac action potentials in a one-dimensional fiber

Action potential duration (APD) restitution, which relates APD to the preceding diastolic interval (DI), is a useful tool for predicting the onset of abnormal cardiac rhythms. However, it is known that different pacing protocols lead to different APD restitution curves (RCs). This phenomenon, known as APD rate-dependence, is a consequence of memory in the tissue. In addition to APD restitution, conduction velocity restitution also plays an important role in the spatiotemporal dynamics of cardiac tissue. We present new results concerning rate-dependent restitution in the velocity of propagating action potentials in a one-dimensional fiber. Our numerical simulations show that, independent of the amount of memory in the tissue, waveback velocity exhibits pronounced rate-dependence and the wavefront velocity does not. Moreover, the discrepancy between waveback velocity RCs is most significant for small DI. We provide an analytical explanation of these results, using a system of coupled maps to relate the wavefront and waveback velocities. Our calculations show that waveback velocity rate-dependence is due to APD restitution, not memory.Comment: 17 pages, 7 figure

A pharmacodynamic analysis of resistance trends in pathogens from patients with infection in intensive care units in the United States between 1993 and 2004

<p>Abstract</p> <p>Background</p> <p>Increasing nosocomial pathogen resistance to available antimicrobial agents is of growing concern. While higher MICs can diminish antimicrobial effectiveness, dose adjustments often mitigate this effect. This study's objective was to ascertain whether MICs among major pathogens in the ICU to several commonly used agents have increased enough to significantly impact their ability to achieve bactericidal effect.</p> <p>Methods</p> <p>Cefepime, ceftriaxone, imipenem and piperacillin-tazobactam MICs were determined with 74,394 Gram-negative bacilli obtained from ICU patients with various infections in the US between 1993 and 2004. Results were grouped into four 3-year periods. The predicted cumulative fraction of response (CFR) was estimated based on patient-derived pharmacokinetic values and Monte Carlo simulation. Trends in CFR over the four study periods were assessed using the Cochran-Armitage test. The primary analysis included all organisms combined; <it>Pseudomonas aeruginosa </it>and <it>Acinetobacter </it>species were also evaluated individually.</p> <p>Results</p> <p>In the primary analysis, imipenem 500 mg q6h showed CFRs from 87% to 90% across all four study periods, with a trend toward slightly improved bactericidal target attainment (p < 0.01). CFRs for cefepime 2 g q12h and piperacillin-tazobactam 4.5 g q6h both declined by 2% (p < 0.01 and p < 0.05, respectively), reflecting upward shifts in the underlying MIC distributions. Ceftriaxone had <52% CFR for all regimens in all periods, with no significant trend. Against <it>P. aeruginosa</it>, significant declines in CFR were seen for (range, p-value): imipenem 1 g q8h (82%–79%, p < 0.01), cefepime 1 g q12h (70%–67%, p < 0.01), cefepime 2 g q12h (84%–82%, p < 0.05), piperacillin-tazobactam 3.375 g q6h (76%–73%, p < 0.01), piperacillin-tazobactam 4.5 g q8h (71%–68%, p < 0.01), and piperacillin-tazobactam 4.5 g q6h (80%–77%, p < .01). Against <it>Acinetobacter </it>spp., all regimens of imipenem, cefepime and piperacillin-tazobactam showed significant declines in CFR over time (p < 0.01).</p> <p>Conclusion</p> <p>Our observations suggest that as a result of increasing antimicrobial resistance among ICU pathogens in the US, drug effectiveness, assessed as a function of individual agents' ability to attain pharmacodynamic targets, has declined, especially with <it>P. aeruginosa </it>and <it>Acinetobacter </it>spp. Cefepime 2 g q8h and imipenem were the most potent agents against these species, respectively. More aggressive dosing of all of the agents characterized could preserve their clinical utility, but this must be balanced with safety and tolerability issues by the physician.</p

100 opportunities for more inclusive ocean research: cross-disciplinary research questions for sustainable ocean governance and management

In order to inform decision making and policy, research to address sustainability challenges requires cross-disciplinary approaches that are co-created with a wide and inclusive diversity of disciplines and stakeholders. As the UN Decade of Ocean Science for Sustainable Development approaches, it is therefore timely to take stock of the global range of cross-disciplinary questions to inform the development of policies to restore and sustain ocean health. We synthesized questions from major science and policy horizon scanning exercises, identifying 89 questions with relevance for ocean policy and governance. We then scanned the broad ocean science literature to examine issues potentially missed in the horizon scans and supplemented the horizon scan outcome with 11 additional questions. This resulted in an unprioritized list of 100 general questions that would require a cross-disciplinary approach to inform policy. The questions fell into broad categories including: coastal and marine environmental change, managing ocean activities, governance for sustainable oceans, ocean value, and technological and socio-economic innovation. Each question can be customized by ecosystem, region, scale, and socio-political context, and is intended to inspire discussions of salient cross-disciplinary research directions to direct scientific research that will inform policies. Governance and management responses to these questions will best be informed by drawing upon a diversity of natural and social sciences, local and traditional knowledge, and engagement of different sectors and stakeholders