13,116 research outputs found
Extending Invitations, Becoming Messmates
As music educators we can model proactive advocacy among community members to prevent individuals\u27 reactive violence in response to intolerance for differences. We can offer music-learning tables as safe spaces in which community members openly and collaboratively learn to know each other as individuals with diverse identities and interests. As messmates around the table, we can identify ways that researching, questioning, and being musical together can eradicate fears and the damaging effects of homophobia
Influence of vertical transport on free tropospheric aerosols over the central USA in springtime
Measurements of the atmospheric aerosol chemical composition during the Subsonic Aircraft: Contrail and Cloud Effects Special Study (SUCCESS) indicate substantial vertical transport of boundary layer aerosol to the free troposphere over the south-central United States during springtime. Mixing ratios of water-soluble aerosol Ca 2+ at 6 - 12 km altitude exhibited a median mixing ratio of 20 pptv, with 15% of the measurements \u3e 100 pptv and a maximum of ! 235 pptv. In air parcels with enhanced Ca 2+, the ratios K+/Ca 2+, Mg2+/Ca 2+, and Na+/Ca 2+ in the bulk aerosol were distinctly characteristic of those in limestone and/or cement. Significantly enhanced mixing ratios of aerosol SO42-, NO3-, and NH4 + were also concomitant with the elevated Ca 2+, suggesting transport of both crustal and anthropogenic aerosols to the upper troposphere. The mass concentration of water-soluble aerosol material was in the range 0.1 - 6 pg m -3 STP, and estimated crustal dust levels were 7 - 160 pg m \u273 ST
Research opportunities in muscle atrophy
Muscle atrophy in a weightless environment is studied. Topics of investigation include physiological factors of muscle atrophy in space flight, biochemistry, countermeasures, modelling of atrophied muscle tissue, and various methods of measurement of muscle strength and endurance. A review of the current literature and suggestions for future research are included
Research opportunities in loss of red blood cell mass in space flight
Decreases of red blood cell mass and plasma volume have been observed consistently following manned space flights. Losses of red cell mass by United States astronauts have averaged 10 to 15% (range: 2 to 21%). Based on postflight estimates of total hemoglobin, Soviet cosmonauts engaged in space missions lasting from 1 to 7 months have exhibited somewhat greater losses. Restoration of red cell mass requires from 4 to 6 weeks following return to Earth, regardless of the duration of space flight
Recommendations for high intensity upper body exercise testing
Introduction: For given submaximal and maximal peak power outputs aerobic responses to upper body exercise are different to those for lower body exercise (Sawka, 1986: Exercise & Sport Sciences Reviews, 14, 175-211). However, much less is known regarding responses to exercise intensities at and around peak oxygen up take (VO2peak). Purpose: The purpose of this study was to determine the metabolic responses during arm crank ergometry (ACE) below, at and above peak oxygen uptake and to help establish exercise testing guidelines for high intensity upper body exercise. Methods: Following institutional ethical approval fourteen male students (Age 21.1, s = 6.1 years and 2.44 s=0.44 VO2peak) volunteered to take part in this study. Each participant exercised on a table mounted cycle ergometer (Monark 894E, Monark Exercise AB, Sweden). After habituation peak minute power (PMP) was calculated from an incremental test. Subsequently each participant completed four continuous work tests (CWT) to volitional exhaustion at 80%, 90%, 100% and 110% of PMP. All tests were completed at 70 rev∙min-1 with a minimum of 48-h between tests and the order was counterbalanced. Each CWT was preceded by a 5 min warm-up, loaded with a mass corresponding to the participants 80% PMP for 20 s at minutes 2, 3 and 4. Oxygen uptake (VO2), respiratory exchange ratio (RER), heart rate (HR) and ratings of perceived exertion for the arms (local (RPEL) and cardiorespiratory strain (RPECR) were recorded at 1 min, 2 min and at volitional exhaustion. The EMG responses at three sites (flexor carpi ulnaris, biceps brachii and triceps brachii lateral) were recorded using double-differential (16-3000 Hz bandwidth, x300 gain), bipolar, active electrodes (MP-2A, Linton, Norfolk, UK). Electromyographic data were sampled at 1000 Hz and filtered using a 20 to 500 Hz band-pass filter (MP150 Data Acquisition and AcqKnowledge 4.0, Biopac, Goleta, CA). The EMG signals for each muscle were root mean squared (RMS) with a 500-ms sample window. The signal was then normalised, prior to each CWT, as a percentage of the mean of 3 sets of 10 duty cycles completed during the warm-up (see above) when the participants 80% PMP for 20 s was applied. Time to exhaustion (Tlim) was recorded as the performance outcome measure. Data for Tlim were analysed using one-way analysis of variance. Differences in EMG, VO2, RER, HR, RPEL and RPECR were analysed using separate two-way analysis of variance with repeated measures (trial x time). All analyses were performed using the Statistical Package for Social Sciences ( 17.0; SPSS Inc., Chicago, IL). Individual differences in means were located using Bonferroni post-hoc correction. Significance was accepted at P < 0.05. Results: As resistive load increased Tlim decreased (611 s=194, 397 s=99, 268 s=90, 206 s=67s, respectively; P < 0.001, ES = 0.625). Post-hoc analysis revealed that Tlim using 80%PMP was longer than for 90%, 100% and 110% PMP trials (P < 0.001) and 90% was longer than both 100% and 110% PMP trials (P = 0.079, P = 0.001). At exhaustion VO2 was similar across trials (P = 0.413, ES = 0.053), although 80% PMP VO2 tended to be less (2.10 s=0.32 l·min-1) than for 90% (2.29 s=0.37), 100% (2.33 s=0.49) and 110% (2.26 s=0.34). Also, 80% PMP VO2 was less than VO2peak (P = 0.013). There were differences in RER at Tlim (P < 0.001, ES = 0.593) with values increasing with % PMP (1.15 s=0.07, 1.26 s=0.07, 1.36 s=0.10, 1.40 s=0.09, respectively). There were no differences across trials for HR at Tlim (~173 (12); P = 0.834, ES = 0.016) and HR was proportional to %PMP at 1 min, and 2 min. For flexor carpi ulnaris there was an increase in activation as exercise intensity increased (P < 0.001, ES = 0.245). There were a similar responses for biceps brachii and triceps brachii demonstrating an increase in activation with exercise intensity (P <0.001, ES = 0.137, P < 0.001, ES = 0.163, respectively). No differences for RPEL and RPECR were observed at Tlim. Discussion: There was a clear response of Tlim with intensity as expected for lower body exercise (Hill et al., 2002: Medicine and Science in Sports and Exercise, 34(4), 709-714). Despite differences in Tlim across exercise intensities VO2, HR and RPE were similar at exhaustion indicating a functional cardiorespiratory maximum had been reached. As indicated by the RER an increased activation of the anaerobic metabolism with greater exercise intensities (100% and 110%) is likely and therefore this may represent a greater anaerobic component at these two intensities. The increase in EMG activity with intensity could indicate an increase activity with an increase in exercise intensity. Conclusion: It is recommended that due to the combination of muscle activation, oxygen uptake and Tlim that an exercise intensity of 90% or 100% of PMP could be used for high intensity upper body exercise testing
Wetlands: A potentially significant source of atmospheric methyl bromide and methyl chloride
Tropospheric methyl bromide (CH3Br) and methyl chloride (CH3Cl) are significant sources of ozone (O3) destroying halogens to the stratosphere. Their O3 depletion potential (ODP) can be determined from atmospheric lifetimes and therefore their atmospheric budgets, both of which are out of balance with known sink terms larger than identified sources. We have discovered a new source of CH3Br and CH3Cl emissions to the atmosphere at two wetland sites in the Northeastern United States. We have reason to believe that these compounds are biologically produced in situ. Our measurements indicate that the global annual flux of CH3Br and CH3Cl from wetlands could be as high as 4.6 Gg yr−1 Of CH3Br and 48 Gg yr−1 of CH3Cl. These are preliminary estimates based on measurements made during the end of the 1998 growing season, a time period of decreased emissions of other trace gases such as methane (CH4)
The World's Conservation Strategy
Rational use and conservation of living resources must be the active concern of all of us, rich and poor alike, if the world is to continue to develop in any reasonable degree of harmony with Nature. Accordingly it is necessary to recognize that industrial—and even some degree of demographic—development is not necessarily incompatible with environmental protection, and indeed that, in the world to come, conservation and development will have to be widely interlinked. Cognizant of this and of the fundamental need to protect and perpetuate living, renewable resources in the face of ever-mounting and demanding human populations, and stressing the imperative of preserving a holistic approach to these problems of Man's and Nature's ‘only one Earth', IUCN, with the support of UNEP and WWF, and the endorsement of some other bodies, launched, early in 1980, after several laborious redraftings, a ‘World Conservation Strategy', in the manner described in the last part of this paper. It sets a policy for all to follow, taking mankind well away from the merely reactionist basis of conservatio
Translating Environmental Science into Policy and Action
Background/Question/Methods: Many ecologists are skilled at identifying environmental problems and defining solutions, but not at achieving concrete action to implement those insights. The question, then, is how to help ecologists translate environmental science into policy and action. Most ecologists' education and training do not prepare them to be effective in the policy arena, much less in ways to achieve action. Ecologists find disincentives in the form of the academic attitude that somehow the application of science is inferior to so-called "pure science." This ivory tower holdover has been largely discredited in the context of environmental issues, and the discipline of conservation biology exists explicitly to foster applications of science, but the attitude remains a potent obstacle, especially for younger ecologists seeking academic acceptance and tenure. Even when ecologists ignore or overcome this obstacle there are few resources available to provide guidance for achieving action. For example, most textbooks that describe the policy process present an academic picture that bears little relationship to the messy real world process. One approach to providing such guidance has been developed in the Department of Environmental Science and Policy at George Mason University, Fairfax, Virginia. This is a course developed specifically to identify and analyze the basic principles, skills and strategies involved in turning scientific knowledge and information, and the policies derived from them, into action. The course uses a series of actual case histories drawn from experience with local and national U.S. and foreign governments, UN organizations, NGOs and other relevant situations. The approach is to give a case hissory, analyze it and derive from it the principles, strategies and skills that work. The professor describes the setting, background, objective, procedure followed and the result. This is followed by class discussion to analyze the case and identify what lessons can be learned and what specific principles, skills and strategies were responsible for or contributed to the results.

Results/Conclusions: While there are some basic principles that hold true in many situations, no single formula for achieving action can be applied in every case. Each situation is somewhat different and to succeed one has to be able to select from an array of principles and skills to fit them to the special needs. This course is a proven way to provide students with a "tool kit" of principles, skills and strategies to guide them effectively to translate environmental science into policy and action
Site-specific alteration of murine hepatitis virus type 4 peplomer glycoprotein E2 results in reduced neurovirulence
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