The effects of work:rest duration on physiological and perceptual responses during intermittent exercise and performance     

Price M  Moss P 《Journal of sports sciences》2007,25(14):1613-1621

In this study, we examined the effects of different work:rest durations during 20 min intermittent treadmill running and subsequent performance. Nine males (mean age 25.8 years, s = 6.8; body mass 73.9 kg, s = 8.8; stature 1.75 m, s = 0.05; VO(2max) 55.5 ml x kg(-1) x min(-1), s = 5.8) undertook repeated sprints at 120% of the speed at which VO(2max) was attained interspersed with passive recovery. The work:rest ratio was constant (1:1.5) with trials involving either short (6:9 s) or long (24:36 s) work:rest exercise protocols (total exercise time 8 min). Each trial was followed by a performance run to volitional exhaustion at the same running speed. Testing order was randomized and counterbalanced. Heart rate, oxygen consumption, respiratory exchange ratio, and blood glucose were similar between trials (P > 0.05). Blood lactate concentration was greater during the long than the short exercise protocol (P < 0.05), whereas blood pH was lower during the long than the short exercise protocol (7.28, s = 0.11 and 7.30, s = 0.03 at 20 min, respectively; P < 0.05). Perceptions of effort were greater throughout exercise for the long than the short exercise protocol (16.6, s = 1.4 and 15.1, s = 1.6 at 20 min, respectively; P < 0.05) and correlated with blood lactate (r = 0.43) and bicarbonate concentrations (r = 0.59; P < 0.05). Although blood lactate concentration at 20 min was related to performance time (r = - 0.56; P < 0.05), no differences were observed between trials for time to exhaustion (short exercise protocol: 95.8 s, s = 30.0; long exercise protocol: 92.0 s, s = 37.1) or physiological responses at exhaustion (P > 0.05). Our results demonstrate that 20 min of intermittent exercise involving a long work:rest duration elicits greater metabolic and perceptual strain than intermittent exercise undertaken with a short work:rest duration but does not affect subsequent run time to exhaustion.  相似文献   

Effects of achievement standards,choice, sex,and educational level on mathematical performance     

Lisa M. McNeir  W. John Schuldt 《Psychology in the schools》1989,26(4):415-421

The study assessed the effects of achievement standards, and choice of such standards, on mathematics performance in conditions where no tangible rewards were presented for reaching such standards. Elementary, junior high, and high school students performed a multiplication task in conditions where they chose standards, had standards imposed by an experimenter, or had no standards. Results demonstrated that high school students worked more multiplication problems when they chose standards than when identical standards were imposed by an experimenter or when no standards were present. Moreover, male students who chose standards worked more problems than did male students who had no standards; this effect was not found for female students.  相似文献   

Changes in kinematics and arm–leg coordination during a 100-m breaststroke swim     

Samuel W. Oxford  Rob S. James  Michael J. Price  Carl J. Payton  Michael J. Duncan 《Journal of sports sciences》2017,35(16):1658-1665

The purpose of this study was to compare arm–leg coordination and kinematics during 100 m breaststroke in 26 (8 female; 18 male) specialist breaststroke swimmers. Laps were recorded using three 50-Hz underwater cameras. Heart rate and blood lactate were measured pre- and post-swim. Arm–leg coordination was defined using coordination phases describing continuity between recovery and propulsive phases of upper and lower limbs: coordination phase 1 (time between end of leg kick and start of the arm pull phases); and coordination phase 2 (time between end of arm pull and start of leg kick phases). Duration of stroke phases, coordination phases, swim velocity, stroke length (SL), stroke rate (SR) and stroke index (SI) were analysed during the last three strokes of each lap that were unaffected by turning or finishing. Significant changes in velocity, SI and SL (P < 0.05) were found between laps. Both sexes showed significant increase (P < 0.05) in heart rate and blood lactate pre- to post-swim. Males had significantly (P < 0.01) faster swim velocities resulting from longer SLs (P = 0.016) with no difference in SR (P = 0.064). Sex differences in kinematic parameters can be explained by anthropometric differences providing males with increased propelling efficiency.  相似文献   

Animals,Governance and Ecology: Managing the Menace of Venomous Snakes in Colonial India     

Lloyd Price 《Cultural and Social History》2017,14(2):201-217

During the nineteenth century, the British Raj launched a campaign to reduce the number of people killed annually by venomous snakes on the Indian subcontinent. Unlike its successful effort to cull large mammals, the colonial government was forced to abolish its bounty scheme in 1890 and instead seek to use sanitation to reduce interactions between humans and snakes. This article will assess this transition in policy as a means to understand how attitudes towards the governance of animals were shaped by cultural and ecological factors. It will be shown that during its inception, discourses of scientific governance statistically augmented perceptions of the threat posed by snakes, presenting them as a direct yet manageable danger within an anthropocentric cultural model. However, financial and practical limitations forced the government to recognise that the behaviour, seasonal patterns and territorial movements of snakes influenced the rate of mortality, and thus adjust its policy to acknowledge the experience of cohabitation in India’s diverse ecological contexts.  相似文献   

Street Wise: a programme for educating young people about citizenship,rights, responsibilities and the law     

Lisa Hawking 《Educational Psychology in Practice》2012,28(1):111-112

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HUMAN SERVICES FOR THE ELDERLY AND THE ROLE OF UNIVERSITY–COMMUNITY COLLABORATION: PERCEPTIONS OF HUMAN SERVICE AGENCY WORKERS     

Mojisola F. Tiamiyu  Lisa Bailey 《Educational gerontology》2013,39(6):479-492

According to the U.S. Bureau of the Census, in 1998 the 65-74 years age group (18.4 million) was eight times larger than in 1900, the 75-84 years age group (12 million) was 16 times larger, and the 85 and older years age group (4 million) was 33 times larger. It is anticipated that if this trend continues, by 2030, there will be about 70 million older American persons, more than twice their number in 1998. To meet the needs of the older population, governments, foundations, nonprofit organizations, and other groups will have to continue to work on how to increase availability, accessibility, and adequacy of community-based services. One approach will be to encourage community collaboration and partnerships. Funding agencies have encouraged university-community collaboration in recent years. However, none of the studies reviewed for this paper addressed the need for the type of university-community collaboration that our study deals with (i.e., university-community agency collaboration). In particular, our study investigates human service agency workers' perceptions of the availability, accessibility, and adequacy of services to the elderly in Northwest Ohio, and how collaboration with a university can improve service delivery to consumers. The findings of the study provide a general indication of trends, experiences, and problems common to these agencies. The findings also suggest that agency workers do not necessarily have a negative perception of university-community agency collaboration, rather many do not understand how such collaborations will improve services to consumers. Recommendations regarding how to enhance university-community collaborations are made.  相似文献   

Marketing marvel: Extending the life of a Scribner’s bestseller     

Lisa?SpiroEmail author 《Publishing Research Quarterly》2004,19(4):3-16

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Reduced knowledge of results frequency enhances error detection     

Bruechert L  Lai Q  Shea CH 《Research quarterly for exercise and sport》2003,74(4):467-472

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Not virtual,but a real,live, online,interactive reference service     

Jerant LL  Firestein K 《Medical reference services quarterly》2003,22(2):57-68

In today's fast-paced environment, traditional medical reference services alone are not adequate to meet users' information needs. Efforts to find new ways to provide comprehensive service to users, where and when needed, have often included the use of new and developing technologies. This paper describes the experience of an academic health science library in developing and providing an online, real-time reference service. Issues discussed include selecting software, training librarians, staffing the service, and considering the future of the service. Use statistics, question type analysis, and feedback from users of the service and librarians who staff the service, are also presented.  相似文献   

The influence of crank rate on peak oxygen consumption during arm crank ergometry   总被引：1，自引：0，他引：1  

Smith PM  Price MJ  Doherty M 《Journal of sports sciences》2001,19(12):955-960

The aim of this study was to assess the influence of three imposed crank rates on the attainment of peak oxygen consumption (VO2peak) and other physiological responses during incremental arm crank ergometry. Twenty physically active, although non-specifically trained, males volunteered for the study. They completed an exercise protocol using an electrically braked arm ergometer (Lode Angio, Groningen, Netherlands) at crank rates of 60, 70 and 80 rev x min(-1). The order of tests was randomized and they were separated by at least 2 days. Peak VO2 was significantly higher (P < 0.05) at 70 and 80 rev x min(-1) than at 60 rev x min(-1). Peak ventilation volume increased as a function of crank rate and was higher (P < 0.05) at 80 than at 60 rev x min(-1). Peak heart rate was higher (P < 0.05) at 70 and 80 rev x min(-1) than at 60 rev x min(-1). Furthermore, 70 and 80 rev x min(-1) resulted in an extended test time compared with 60 rev x min(-1). The greater physiological responses observed during the tests at the two faster crank rates might have been the result of a postponement of acute localized neuromuscular fatigue, allowing for more work to be completed. We recommend, therefore, that an imposed crank rate between 70 and 80 rev x min(-1) should be used to elicit VO2peak and other physiological responses in arm crank ergometry.  相似文献