123,032 research outputs found

    Commentary on “Evaluation of shooting distance by AFM and FTIR⁄ATR analysis of GSR” Mou Y., Lakadwar J., Rabalais J.W., J. Forensic Sci. 2008; 53:1381-6

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    This piece highlights the disadvantages of utiising atomic force microscopy (AFM) for analysis of gun shot residue (GSR) and other fine powders. Also outlined is the origin of novel particle shapes that can be found in some published images

    Letter from BJ&B to ITGLWF, May 29, 2007 re: Final Agreement

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    This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide.  Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.FLA_BJ_B_Settlement.pdf: 48 downloads, before Oct. 1, 2020

    Dissecting the mechanisms of learning-by-doing in Drosophila

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    At the heart of learning-by-doing lies a well-known psychological phenomenon: information will be remembered better if it is actively generated rather than passively read or heard. First described in humans, this generation effect can also be observed in various animal models. However, the neurobiological mechanisms underlying the generation effect are unknown. Here we show that two reciprocal interactions between its active and passive components contribute to the generation effect in flies. One interaction consists of the active (skill-learning) component facilitating the passive (fact-learning) component. Fact-learning, on the other hand, inhibits skill-learning. Experiments with adenylyl cyclase I deficient _rutabaga_ mutant flies revealed that the fact- but not the skill-learning component requires this evolutionarily conserved learning gene. Using mushroom-body deficient transgenic flies we observed that the mushroom-bodies mediate the inhibition of skill-learning. This inhibition also enables generalization and prevents premature habit formation. Extended training in wildtype flies produced a phenocopy of mushroom-body impaired flies, such that generalization was abolished and goal-directed actions were transformed into habitual responses. Thus, our results identify various neural processes underlying learning-by-doing, delineate some of their synergisms and provide a framework for further dissecting them in a genetically tractable model system

    Economic evaluation of ondansetron: Preliminary analysis using clinical trial data prior to price setting

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    This article has been made available through the Brunel Open Access Publishing Fund and is available from the specified link - Copyright © 1992 Macmillan Press Ltd.This study combines secondary analysis of efficacy and side-effect data from a randomised controlled trial with estimates of resource use to evaluate the likely economic effects of the new antiemetic agent ondansetron. Costs, effects and cost-effectiveness of ondansetron in the prophylaxis of acute nausea and vomiting induced by chemotherapy are assessed relative to antiemetic therapy with metoclopramide. Superior efficacy of ondansetron is quantified both in terms of significant emesis avoided and emesis management costs avoided. A simple cost analysis, with the metoclopramide dosage priced at 10 pounds, indicates that therapy with ondansetron would give equivalent net treatment costs, at a price ratio (ondansetron/metoclopramide) of 2.3 to 1. If therapeutic success is defined as the avoidance of emesis and antiemetic side-effects, then the two therapies would be equally cost-effective at a drug price ratio of 5 to 1. We conclude that, (i) economic evaluation prior to price setting is feasible and informative; (ii) such models can indicate prospective data collection priorities

    Effect of expiratory muscle fatigue on exercise tolerance and locomotor muscle fatigue in healthy humans

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    High-intensity exercise (> or =90% of maximal O(2) uptake) sustained to the limit of tolerance elicits expiratory muscle fatigue (EMF). We asked whether prior EMF affects subsequent exercise tolerance. Eight male subjects (means +/- SD; maximal O(2) uptake = 53.5 +/- 5.2 ml.kg(-1).min(-1)) cycled at 90% of peak power output to the limit of tolerance with (EMF-EX) and without (CON-EX) prior induction of EMF and for a time equal to that achieved in EMF-EX but without prior induction of EMF (ISO-EX). To induce EMF, subjects breathed against an expiratory flow resistor until task failure (15 breaths/min, 0.7 expiratory duty cycle, 40% of maximal expiratory gastric pressure). Fatigue of abdominal and quadriceps muscles was assessed by measuring the reduction relative to prior baseline values in magnetically evoked gastric twitch pressure (Pga(tw)) and quadriceps twitch force (Q(tw)), respectively. The reduction in Pga(tw) was not different after resistive breathing vs. after CON-EX (-27 +/- 5 vs. -26 +/- 6%; P = 0.127). Exercise time was reduced by 33 +/- 10% in EMF-EX vs. CON-EX (6.85 +/- 2.88 vs. 9.90 +/- 2.94 min; P < 0.001). Exercise-induced abdominal and quadriceps muscle fatigue was greater after EMF-EX than after ISO-EX (-28 +/- 9 vs. -12 +/- 5% for Pga(tw), P = 0.001; -28 +/- 7 vs. -14 +/- 6% for Q(tw), P = 0.015). Perceptual ratings of dyspnea and leg discomfort (Borg CR10) were higher at 1 and 3 min and at end exercise during EMF-EX vs. during ISO-EX (P < 0.05). Percent changes in limb fatigue and leg discomfort (EMF-EX vs. ISO-EX) correlated significantly with the change in exercise time. We propose that EMF impaired subsequent exercise tolerance primarily through an increased severity of limb locomotor muscle fatigue and a heightened perception of leg discomfort

    Effect of expiratory muscle fatigue on exercise tolerance and locomotor muscle fatigue in healthy humans

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    High-intensity exercise (> or =90% of maximal O(2) uptake) sustained to the limit of tolerance elicits expiratory muscle fatigue (EMF). We asked whether prior EMF affects subsequent exercise tolerance. Eight male subjects (means +/- SD; maximal O(2) uptake = 53.5 +/- 5.2 ml.kg(-1).min(-1)) cycled at 90% of peak power output to the limit of tolerance with (EMF-EX) and without (CON-EX) prior induction of EMF and for a time equal to that achieved in EMF-EX but without prior induction of EMF (ISO-EX). To induce EMF, subjects breathed against an expiratory flow resistor until task failure (15 breaths/min, 0.7 expiratory duty cycle, 40% of maximal expiratory gastric pressure). Fatigue of abdominal and quadriceps muscles was assessed by measuring the reduction relative to prior baseline values in magnetically evoked gastric twitch pressure (Pga(tw)) and quadriceps twitch force (Q(tw)), respectively. The reduction in Pga(tw) was not different after resistive breathing vs. after CON-EX (-27 +/- 5 vs. -26 +/- 6%; P = 0.127). Exercise time was reduced by 33 +/- 10% in EMF-EX vs. CON-EX (6.85 +/- 2.88 vs. 9.90 +/- 2.94 min; P < 0.001). Exercise-induced abdominal and quadriceps muscle fatigue was greater after EMF-EX than after ISO-EX (-28 +/- 9 vs. -12 +/- 5% for Pga(tw), P = 0.001; -28 +/- 7 vs. -14 +/- 6% for Q(tw), P = 0.015). Perceptual ratings of dyspnea and leg discomfort (Borg CR10) were higher at 1 and 3 min and at end exercise during EMF-EX vs. during ISO-EX (P < 0.05). Percent changes in limb fatigue and leg discomfort (EMF-EX vs. ISO-EX) correlated significantly with the change in exercise time. We propose that EMF impaired subsequent exercise tolerance primarily through an increased severity of limb locomotor muscle fatigue and a heightened perception of leg discomfort

    The Longitudinal Variation of Equatorial Waves due to Propagation on a Varying Zonal Flow

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    The general 1D theory of waves propagating on a zonally varying flow is developed from basic wave theory, and equations are derived for the variation of wavenumber and energy along ray paths. Different categories of behavior are found, depending on the sign of the group velocity cg and a wave property B. For B positive, the wave energy and the wavenumber vary in the same sense, with maxima in relative easterlies or westerlies, depending on the sign of cg. Also the wave accumulation of Webster and Chang occurs where cg goes to zero. However, for B negative, they behave in opposite senses and wave accumulation does not occur. The zonal propagation of the gravest equatorial waves is analyzed in detail using the theory. For nondispersive Kelvin waves, B reduces to 2, and an analytic solution is possible. For all the waves considered, B is positive, except for the westward-moving mixed Rossby–gravity (WMRG) wave, which can have negative B as well as positive B. Comparison is made between the observed climatologies of the individual equatorial waves and the result of pure propagation on the climatological upper-tropospheric flow. The Kelvin wave distribution is in remarkable agreement, considering the approximations made. Some aspects of the WMRG and Rossby wave distributions are also in qualitative agreement. However, the observed maxima in these waves in the winter westerlies in the eastern Pacific and Atlantic Oceans are generally not in accord with the theory. This is consistent with the importance of the sources of equatorial waves in these westerly duct regions due to higher-latitude wave activity
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