Age-related differences in vision and proprioception in a lower limb interceptive task: the effects of skill level and practice     

Williams AM  Weigelt C  Harris M  Scott MA 《Research quarterly for exercise and sport》2002,73(4):386-395

This study examined age-related differences in the role of visual proprioception during a lower limb interceptive action and how this varies as a function of skill and practice. In Experiment 1, skilled and less-skilled 8-, 10-, and 12-year-old boys controlled a soccer ball using their preferred foot under full vision and when sight of the effector was occluded. With the exception of the high-skilled 12-year-olds and low-skilled 8-year-olds, participants showed a decrement in peformance when denied access to visual proprioception. In Experiment 2, the effect of practicing under different informational constraints was examined for 12 year-old boys. Children performed varying amounts of practice under full vision, or in a condition where sight of the foot was occluded, before being transferred to the alternative viewing condition. Participants who practiced under occluded viewing conditions showed greater relative improvement in performance over practice and transfer sessions compared with a full vision control group. Some support is provided for the manipulation of visual informational constraints as an effective pedagogical approach to motor learning.  相似文献   

Visual search and biological motion perception in tennis   总被引：1，自引：0，他引：1  

Ward P  Williams AM  Bennett SJ 《Research quarterly for exercise and sport》2002,73(1):107-112

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The Loughborough Intermittent Shuttle Test: a field test that simulates the activity pattern of soccer     

Nicholas CW  Nuttall FE  Williams C 《Journal of sports sciences》2000,18(2):97-104

The aims of this study were to describe and determine the test-retest reliability of an exercise protocol, the Loughborough Intermittent Shuttle Test (the LIST), which was designed to simulate the activity pattern characteristic of the game of soccer. The protocol consisted of two parts: Part A comprised a fixed period of variable-intensity shuttle running over 20 m; Part B consisted of continuous running, alternating every 20 m between 55% and 95% VO2max, until volitional fatigue. Seven trained games players (age 21.5+/-0.9 years, height 182+/-2 cm, body mass 80.1+/-3.6 kg, VO2max 59.0+/-1.9 ml x kg(-1) x min(-1); mean +/- s(x)) performed the test on two occasions (Trial 1 and Trial 2), at least 7 days apart, to determine the test-retest reliability of the sprint times and running capacity. The physiological and metabolic responses on both occasions were also monitored. The participants ingested water ad libitum during the first trial, and were then prescribed the same amount of water during the second trial. The 15 m sprint times during Trials 1 and 2 averaged 2.42+/-0.04 s and 2.43+/-0.04 s, respectively. Run time during Part B was 6.3+/-2.0 min for Trial 1 and 6.1+/-1.3 min for Trial 2. The 95% limits of agreement for sprint times and run times during Part B were -0.14 to 0.12 s and -3.19 to 2.16 min respectively. There were no differences between trials for heart rate, rating of perceived exertion, body mass change during exercise, or blood lactate and glucose concentrations during the test. Thus, we conclude that the sprint times and the Part B run times were reproducible within the limits previously stated. In addition, the activity pattern and the physiological and metabolic responses closely simulated the match demands of soccer.  相似文献   

Temporal patterning of competitive emotions: a critical review   总被引：1，自引：1，他引：0  

Cerin E  Szabo A  Hunt N  Williams C 《Journal of sports sciences》2000,18(8):605-626

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Evaluating carrascolendas: A television series for Mexican‐American children     

Frederick Williams  Diana S. Natalicio 《广播与电子媒介杂志》2013,57(3):299-309

Readers with young children may have noticed the occasional Spanish language vignettes appearing from time to time on Sesame Street, the popular public television program for pre‐schoolers. The following article describes the development and audience impact of a program designed to reach a Spanish‐American audience in a Texas city. The study is presented primarily as a guide for other programmers desiring to evaluate audience effects of such content. This article is a summary of a longer report done under an Office of Education subcontract to the Center for Communication Research at the University of Texas. Dr. Williams is Director of the Center and professor in the school of communications, while Diana Natalicio is now an assistant professor of linguistics at the University of Texas at El Paso after having completed her doctorate in linguistics at the Austin campus in 1970.  相似文献   

Public Choices and Social Learning: The New Multimedia Technologies in Europe     

Robin Williams 《The Information Society》2000,16(4):251-262

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Help for the teacher of disturbed children in the public school: the use of consultation for problem solving and personal growth     

M E Williams 《Exceptional children》1967,34(2):87-91

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Increased dietary carbohydrate and endurance during single-leg cycling using a limb with normal muscle glycogen concentration     

A E Hardman  C Williams 《Journal of sports sciences》1989,7(2):127-138

The purpose of this study was to test the hypothesis that increased availability of blood-borne glucose would improve endurance after carbohydrate loading. A single-leg exercise model was employed, taking advantage of the fact that supercompensation of muscle glycogen occurs only in a previously exercised limb. Endurance time to exhaustion at 70% of maximal oxygen uptake (VO2 max) was determined for 11 males and three females who were then allocated to a control group or a high-carbohydrate (CHO) group. For 3 days following Test 1 the control group maintained a prescribed normal diet whilst the CHO group increased the proportion of energy derived from carbohydrate (62.1 +/- 4.3% cf. 43.9 +/- 2.0%, P less than 0.01). The endurance test was then repeated using the leg that was inactive during Test 1. Endurance time was increased on Test 2 (123.7 +/- 43.2 min cf. 98.5 +/- 21.9 min, P less than 0.05 one-tailed test) for the CHO group but not for the control group (101.8 +/- 21.7 min cf. 107.5 +/- 9.1 min, NS). There was no indication of enhanced carbohydrate metabolism during Test 2 for the CHO group but mean heart rate was lower during Test 2 than during Test 1 (145 +/- 14 beat min-1 cf. 152 +/- 12 beat min-1, P less than 0.05). These results suggest that the prior consumption of a high-carbohydrate diet improves endurance during high-intensity cycling with a limb with normal muscle glycogen concentration.  相似文献   

Microcomputer applications in a hospital library     

T Williams 《Bulletin of the Medical Library Association》1985,73(2):207-210

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What Is Motor Development?     

Kathleen Williams 《Quest (Human Kinetics)》2013,65(3):179-182

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