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As a participating student in the Border Studies Program in the fall semester of 2000, the author did a field study working as a volunteer at El Centro de los Trabajadores Agrvcolas Fronterizos (The Border Agricultural Workers' Center, or CTAF). In this ethnography, he intertwines the exploration of several different relationships. He examines the relationship between the current struggles of farm workers in the U.S. and the movement led by Cesar Chavez in the 1970s; and the relationship between the ''periphery'' and the ''center.'' He also reflects upon his own position within the progressive movement, given the social privilege that adheres to him by virtue of race, class, and sex.  相似文献   
23.

Recent studies in exhibitions have begun to consider the cognitive content of the ‘dialogue’ between visitor and exhibit designer. Such studies have focused on the leisure visitor and not on organised school visits. The study reported here compares the conversational content of primary school and family visitors at the London Zoo and the Natural History Museum, London. The data show that there are common features to the children's interactions with animal exhibits and that the content of the conversations varies little between family groups and school groups both within an institution and between institutions. The lack of any marked distinction between school and family visitors strongly suggests that schools are failing to make effective use of the educational potential of zoos. Secondly, the findings of this study are important in pointing to the features of animal exhibits to which children, and their accompanying adults, attend. The data suggest that there is a gulf between the level of knowledge and understanding visitors bring to the exhibits and the message that the museums and zoos may wish to communicate. It is suggested that more successful education will only be achieved when museums and zoos give more credence to understanding what the visitor already does, or does not, know.  相似文献   
24.
The purpose of this study was to assess receptivity to peer teaching and peer learning about the safe and appropriate use of medications among communitydwelling older adults. The sample was predominately White (88.5%), female (75.9%) older adults with an average age of 80.2 ( - 9.1) years. On average, the participants perceived their health status as good (2.8 - 0.6). In addition, participants reported using an average number of 4.4 ( - 3.3) prescribed medications. The majority (75%) of participants also reported no problems with their medications. With respect to receptivity to peer teaching and peer learning, the participants, on average, were neutral to peer teaching (6.0 - 2.4), but were somewhat receptive to peer learning (6.7 - 2.2). The number of prescribed medications that a participant reported taking and the age of a participant were identified as significant predictors of receptivity to peer teaching and accounted for 14.5% of the total variance ( F = 5.84, df = 2, p = 0.005). For receptivity to peer learning, the number of prescribed medications also was a significant predictor ( F = 7.50, df = 1, p = 0.008). This study provides the initial step to identifying community-dwelling older adults who would be receptive to peer teaching and peer learning about the safe and appropriate use of medications.  相似文献   
25.
面对学生的错误,传统的做法是直接把正确的答案教给学生,因为这样可以节省教学时间,增加课堂训练的密度和强度.但评讲不久便发现,错误又死灰复燃,许多同学依然重复"昨天的故事".究其原因,由于这种评讲没有切入学生解题时犯错的真实情境,评讲缺乏针对性,教学的低效性自然也就显现出来了.  相似文献   
26.
Arterial spin labelling (ASL) provides a potential method to non-invasively determine muscle blood flow and examine the impact of interventions such as supplementation and training. However, it's a method with intrinsically low signal, leading to limitations in accuracy and temporal resolution. To examine these limitations, the current study measured perfusion via ASL on three occasions in the rectus femoris of 10 healthy adults, during light and moderate exercise, over three different exercise durations. For data sampled over 9 min, light intensity exercise gave an average perfusion of 35.0 ± 5.1 ml/min.100g?1 with a coefficient of variation (COV) of 16% and single intraclass correlation coefficient (ICC) of 0.67. For the moderate bout, perfusion was 51.3 ± 5.6 ml/min.100g?1 (COV 10%, ICC 0.82). When the same data were analyzed over 5 min 24 s, perfusion was 37.8 ± 11.13 (COV 30%, ICC 0.13) during light and 49.5 ± 8.8 ml/min.100g?1 (COV 18%, ICC 0.52) during moderate exercise. When sampling was reduced to 1 min 48 s, perfusion was 41.2 ± 13.7 (COV 33%, ICC 0.26) during light and 49.5 ± 13.6 ml/min.100g?1 (COV 28%, ICC 0.04) during moderate exercise. For 9 min a significant perfusion difference was found between the exercise intensities; however, this was not the case for sampling over 5 min 24 s or 1 min 48 s. Such findings illustrate the potential of ASL to non-invasively monitor muscle perfusion under steady-state conditions, but highlight that extended exercise protocols are necessary in order to generate date of sufficient reliability to be able to discriminate intervention dependent perfusion differences.  相似文献   
27.
Artificial surfaces are now an established alternative to grass (natural) surfaces in rugby union. Little is known, however, about their potential to reduce injury. This study characterises the spinal kinematics of rugby union hookers during scrummaging on third-generation synthetic (3G) and natural pitches. The spine was sectioned into five segments, with inertial sensors providing three-dimensional kinematic data sampled at 40 Hz/sensor. Twenty-two adult, male community club and university-level hookers were recruited. An equal number were analysed whilst scrummaging on natural or synthetic turf. Players scrummaging on synthetic turf demonstrated less angular velocity in the lower thoracic spine for right and left lateral bending and right rotation. The general reduction in the range of motion and velocities, extrapolated over a prolonged playing career, may mean that the synthetic turf could result in fewer degenerative injuries. It should be noted, however, that this conclusion considers only the scrummaging scenario.  相似文献   
28.
Heavy training is associated with increased respiratory infection risk and antimicrobial proteins are important in defence against oral and respiratory tract infections. We examined the effect of 14 weeks of vitamin D3 supplementation (5000 IU/day) on the resting plasma cathelicidin concentration and the salivary secretion rates of secretory immunoglobulin A (SIgA), cathelicidin, lactoferrin and lysozyme in athletes during a winter training period. Blood and saliva were obtained at the start of the study from 39 healthy men who were randomly allocated to vitamin D3 supplement or placebo. Blood samples were also collected at the end of the study; saliva samples were collected after 7 and 14 weeks. Plasma total 25(OH)D concentration increased by 130% in the vitamin D3 group and decreased by 43% in the placebo group (both = 0.001). The percentage change of plasma cathelicidin concentration in the vitamin D3 group was higher than in the placebo group (= 0.025). Only in the vitamin D3 group, the saliva SIgA and cathelicidin secretion rates increased over time (both = 0.03). A daily 5000 IU vitamin D3 supplement has a beneficial effect in up-regulating the expression of SIgA and cathelicidin in athletes during a winter training period, which could improve resistance to respiratory infections.  相似文献   
29.
The relationships between team performance indicators and match outcome have been examined in many team sports, however are limited in Australian Rules football. Using data from the 2013 and 2014 Australian Football League (AFL) regular seasons, this study assessed the ability of commonly reported discrete team performance indicators presented in their relative form (standardised against their opposition for a given match) to explain match outcome (Win/Loss). Logistic regression and decision tree (chi-squared automatic interaction detection (CHAID)) analyses both revealed relative differences between opposing teams for “kicks” and “goal conversion” as the most influential in explaining match outcome, with two models achieving 88.3% and 89.8% classification accuracies, respectively. Models incorporating a smaller performance indicator set displayed a slightly reduced ability to explain match outcome (81.0% and 81.5% for logistic regression and CHAID, respectively). However, both were fit to 2014 data with reduced error in comparison to the full models. Despite performance similarities across the two analysis approaches, the CHAID model revealed multiple winning performance indicator profiles, thereby increasing its comparative feasibility for use in the field. Coaches and analysts may find these results useful in informing strategy and game plan development in Australian Rules football, with the development of team-specific models recommended in future.  相似文献   
30.
The aim of this study was to investigate how the type of contact influences physiological, perceptual and locomotive load during a simulated rugby league match. Eleven male university rugby league players performed two trials of the rugby league movement simulation protocol for interchange forwards with a traditional soft tackle bag and a weighted tackle sled to replicate contact demands. The interchange forward-specific simulation was chosen given the contact frequency is higher for this group of players compared to whole match players. Locomotive rate, sprint speed, tackle intensity, heart rate (HR) and rating of perceived exertion were analysed during the first and second bouts that replicated two ~23 min on-field passages. Countermovement jump (CMJ) was measured before and immediately after each trial. More time was spent in heart rate zone between 91 and 100% HRpeak during the first (effect size ± 90% confidence interval: 0.44 ± 0.49) and second bouts (0.44 ± 0.43), and larger (0.6 ± 0.69) decrements in CMJ performance were observed during the sled trial (5.9, = 4.9%) compared to the bag trial (2.6, = 5.4%). Changing the type of contact during the match simulation subtly altered both the internal and external loads on participants. Using a standard tackle bag results in faster sprint speed to contact, but lower overall high-intensity running. Conversely, a heavier tackle object increases the internal load and results in greater lower limb neuromuscular fatigue as reflected by the decrease in CMJ performance.  相似文献   
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