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951.
Although motorcycling performance strongly depends on the characteristics of the motorcycles and capabilities of the riders, little information is available on the physiological profiles of riders. The aim of this study was to evaluate the physical load of official international men's road-race motorcycling competitions. Data were obtained from 34 male riders during the 2005 European Road-Race Motorcycling Championship (categories classified by size of engine: 125 GP, 250 GP, and 600 cc) during free practices, qualifying sessions, and official races. Participants' heart rates were recorded and blood lactate concentrations determined. During races, heart rates were most often above 90% of maximum heart rate (frequency of occurrence: 125 GP = 92.9%, s = 5.3; 250 GP = 93.6%, s = 7.3; 600 cc = 93.2%, s = 10.2). The heart rate distribution during riding showed main effects between phases of competition, engine sizes, and different portions of the race (P < 0.001). No difference was observed between riders on and not on the podium at the end of the race. Peak blood lactate concentrations after the qualifying sessions (5.2 mmol . l(-1), s = 1.2) and official races (6.0 mmol . l(-1), s = 2.1) were higher (P < 0.001) than at baseline. The present results show that road-race motorcycling imposes a high load on the riders, who should possess adequate fitness to maintain high-speed rides and minimize the effects of fatigue during competition. 相似文献
952.
Laura A. Hogarth William A. Roberts Shelley Roberts Benjamin Abroms 《Learning & behavior》2000,28(1):43-58
We performed six experiments in order to examine the ability of rats to use moving beacons and landmarks as cues to the location of reward on an eight-arm radial maze. In Experiments 1–4, the cues and goals were moved before each trial, and groups in which a single beacon was placed on the rewarded arm, a single landmark indicated that reward was on the arm immediately to the left of a landmark, or two landmarks were placed on each side of the reward arm were compared. The rats rapidly learned to track the reward in the beacon condition, failed to find the reward sooner than chance expectation with a single landmark, and did only slightly better than chance with two landmarks. In Experiments 5 and 6, the rats were trained in five trials per day, with the landmark and goal locations constant over daily rewarded trials, and in two extinction trials that were inserted among the rewarded trials. The rats found the goal arm at substantially better than chance expectancy with both one and two landmarks. Our results, in agreement with data from recent swimming pool experiments (A. D. L. Roberts & Pearce, 1998), show that rats will use the relationship between moving landmarks and a goal in order to find reward. 相似文献
953.
Laura Grünberg 《Higher Education in Europe》1999,24(3):395-404
Summarizing the incomplete results of the UNESCO Programme on “Good Practice in Promoting Gender Equality in Higher Education”;, the author asks that any assessment of the progress made in the area of gender‐sensitive education take regional specificities into account. The regional environment is at best neutral and usually hostile to feminism in subtle ways. In spite of the lack of tradition and experience in gender‐sensitive social institutions, valuable things have been happening in the region. Placed within their socio‐economic and political contexts (and not necessarily judged according to western standards) individuals, programmes, and institutions are pioneering in the field. Access to the benefits of an education incorporating a coherent gender dimension is, for the time being, limited. Some reasons for this situation are outlined in this article. 相似文献
954.
Laura V. Martinez Stella Ting-Toomey Tenzin Dorjee 《Journal of Intercultural Communication Research》2016,45(6):503-525
This study explored the identity management processes in interfaith marital communication in a United States setting. Sixteen marital partners participated in this interview study. Interviews were transcribed verbatim, interpreted, and analyzed. Guided by identity management theory, the interview data analysis revealed three general themes: development of the interfaith relational identity via the co-creation of a superordinate spiritual and value system; implementation of relational boundaries to prioritize the relational identity; and identification of key milestone decisions (i.e. wedding plans and children socialization coordination) interfaith partners face in their intimate relationships. Contributions, limitations, and directions for future studies on interfaith marital communication are addressed. 相似文献
955.
Laura Tisdall 《Cultural and Social History》2013,10(4):489-507
AbstractThe 1950s saw a wave of depictions of threatening male working-class adolescents in English novels, films and cartoons. However, these texts must be contextualised not only as part of the well-documented 1950s moral panic about youth but in relation to the popularized psychological concepts of the ‘normal’ and ‘deviant’ child and the increasing implementation of progressive educational ideas that artificially limited working-class pupils’ horizons. This makes this period not only another reiteration of the perennial moral panics about the rising generation that Geoffrey Pearson has documented, but an emergence of a new way of conceptualizing youth. 相似文献
956.
This study employed ordinal logistic regression analyses to investigate the relationship between American adolescents' participation in physical activity and depressive symptomatology. Data were drawn from the second Child Development Supplement to the Panel Study of Income Dynamics (CDS II), which was conducted over 2002-2003. Fewer than 60% of adolescents were found to accumulate 60 min of moderate-to-vigorous physical activity (MVPA) outside of school hours on week or weekend days. Accumulated duration of MVPA was not, however, significantly associated with severity of depressive symptoms for either gender. Males who were not involved in sporting clubs or lessons were more likely than males who were highly involved to experience greater severity of depressive symptoms (OR = 3.24, CI = 1.33, 7.87). Results highlight gender variability in the psychosocial correlates of sporting participation and prompt further investigation of the relevance of current physical activity guidelines for mental health in adolescence. 相似文献
957.
958.
AbstractIn policy contexts, social exclusion can be experienced through the systematic marginalization of groups by inhibiting their ability to access resources and support. In this article, we consider the context of community sport development in rural Canada to discuss the implications of rationalized policy systems for rural citizens. We discuss instances where engagement with the sport system was constrained as well as the way that rural people responded in order to continue engagement in sport both within and outside of policy frameworks. A more inclusive sport policy system requires the acknowledgement of diverse social outcomes which may be realized through sport. But, in order for this to take place, policy makers and practitioners must acknowledge that these outcomes can exist outside of athlete development and must re-consider the ways that resources and support can be allocated. 相似文献
959.
Laura Simoni Guido Pasquini Silvia Pancani Federica Vannetti Claudio Macchi Silvia Pogliaghi 《Journal of sports sciences》2020,38(20):2321-2328
ABSTRACT Studies on running biomechanics and energetics are usually conducted on a treadmill. To ensure that locomotion on a treadmill is comparable to locomotion overground, participants need to be expert in the use of the device. This study aimed to identify the number and duration of sessions needed to obtain stable measurements for spatiotemporal and metabolic parameters in unexperienced treadmill runners. Fourteen male recreational runners performed three 15-min treadmill running trials in different days at a submaximal speed. Spatiotemporal and metabolic parameters were registered at minutes: 5, 10, 15 and their within-trial and between-trial changes were analysed using a two-way repeated measures ANOVA and Bonferroni post-hoc test. Within-trial differences were found in step frequency (decreased over time), Step Length and Contact Time (increased), reaching stability at different time points. Ventilator parameters increased, reaching stability after 5–10 min, while heart rate increased progressively over time. The only between-trial differences were an increase in step length and a decrease in step frequency at min 1, between trials 1 and 3. In conclusion, at least three running trials of 15 min are required to familiarize with the device. The last 5 min of the third trial can be regarded as stable measurements. 相似文献
960.
Emil List Larsen Henrik Enghusen Poulsen Cristina Michaelsen Laura Kofoed Kjær Mark Lyngbæk Emilie Skytte Andersen 《Journal of sports sciences》2020,38(18):2080-2091
ABSTRACT
Acute and adaptive changes in systemic markers of oxidatively generated nucleic acid modifications (i.e., 8-oxo-7,8-dihydro-2?-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo)) as well as inflammatory cytokines (i.e., C-reactive protein, interleukin-6, interleukin-10, and tumour necrosis factor alpha), a liver hormone (i.e., fibroblast growth factor 21 (FGF21)), and bone metabolism markers (sclerostin, osteocalcin, C-terminal telopeptide, and N-terminal propeptide of type 1 procollagen) were investigated following a marathon in 20 study participants. Immediate changes were observed in inflammatory cytokines, FGF21, and bone metabolism markers following the marathon. In contrast, no immediate changes in urinary excretion of 8-oxodG and 8-oxoGuo were evident. Four days after the marathon, decreased urinary excretion of 8-oxodG (-2.9 (95% CI -4.8;-1.1) nmol/24 h, P < 0.01) and 8-oxoGuo (-5.8 (95% CI -10.3;-1.3) nmol/24 h, P = 0.02) was observed. The excretion rate of 8-oxodG remained decreased 7 days after the marathon compared to baseline (-2.3 (95%CI -4.3;-0.4) nmol/24 h, P = 0.02), whereas the excretion rate of 8-oxoGuo was normalized. In conclusion marathon participation immediately induced a considerable inflammatory response, but did not increase excretion rates of oxidatively generated nucleic acid modifications. In fact, a delayed decrease in oxidatively generated nucleic acid modifications was observed suggesting adaptive antioxidative effects following exercise. 相似文献