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21.
Purpose: In a cross-sectional study design, we evaluated the resting heart rate (HRbaseline) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, Mage = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers (CG; n = 25, Mage = 25.9 ± 4.5 years). Method: All participants underwent a submaximal exercise test. At 85% of the maximal predicted HR, the recovery protocol was started, and heart rate recovery (HRR) was recorded during 1-min intervals for 5 min. Results: Compared with CG, BD showed lower HRbaseline (70 beats per minute [bpm] vs. 62 bpm, respectively, U = 143, p < .05, ES = .46), lower preexercise HR (94 bpm vs. 86 bpm, U = 157, p < .05, ES = .42), longer exercise test duration (346 s vs. 420 s, U = 95.5, p < .05, ES = .59), and higher HRR for 5 min postexercise (U = 1.29–1.89, p < .05, ES = .33–.50) as follows: 1st min (32 bpm vs. 40 bpm), 2nd min (45 bpm vs. 53 bpm), 3rd min (51 bpm vs. 58 bpm), 4th min (55 bpm vs. 59 bpm), and 5th min (59 bpm vs. 63 bpm). The coefficient of HRR from the 1st min to the 5th min postexercise was similar in both groups (U = 229–311, p > .05, ES = < .10–.22). Conclusion: Heightened cardiovascular functional status characterized by favorable enhanced chronotropic dynamics appears to occur in practitioners of recreational ballroom dancing, which suggests that this modality of exercise may result in health benefits.  相似文献   
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The case is considered in which, during the operation of an optimal control system, the optimizer, in addition to applying his usual control, may switch structures. Necessary and sufficient conditions are derived and emphasis is placed on the special characteristics of this problem. Continuous and discrete time set-ups are considered and the separation principle is shown not to hold for the linear quadratic case in the presence of noise.  相似文献   
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The relations of the CAK-C to the Stanford-Binet and the WRAT were explored for a sample of 155 educable mentally retarded children. Correlational analyses indicated that: (a) The CAK-C is more closely related to MA than to either CA or IQ. (b) Both Reading and Arithmetic are more closely related to MA than to the CAK-C. The results support the position that Piagetian intelligence is somewhat distinct from psychometric intelligence, but suggest that the latter is the better predictor of academic achievement.  相似文献   
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In this study, sanitized coverage of the United States’ use of military drone strikes in foreign countries is pitted against more graphic news images in an experimental setting to determine effects on attitudes toward the use of U.S. military drones. In addition, multiple news exposures are tested to determine whether individuals can become emotionally inured to such coverage, even when images are more graphic. Key results find those who viewed graphic news visuals did not show evidence of desensitization after repeated viewing and expressed higher levels of concern regarding drone use but not reduced support for U.S. drone policy.  相似文献   
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The main aim of this study was to assess the separate and combined effects of exercise and nasal splinting on static and dynamic measures of nasal airflow. In a randomized crossover design, 12 healthy participants (6 men, 6 women) performed static and dynamic spirometric nasal airflow assessment tests, with or without nasal splinting (Breathe-Right?), before and after a maximal oxygen uptake (VO 2max ) treadmill test. At least 7 days later, the V O 2max and nasal airflow tests were repeated. The results showed that the measured variables were not significantly different with and without nasal splinting. We conclude that the absence of significantly enhanced nasal patency observed for nasal splinting and after exercise suggest that these factors have a minimal impact on nasal airflow volume and rate.  相似文献   
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Abstract

Little evidence exists to assess the effects of dance training on special populations. Research in this field has relied on pretest-posttest methods for gathering data. While such data gathering methods may be appropriate for particular research problems, alone they may be inadequate for broad-based, exploratory investigations of programs and effects. The present study is an example of a multiple measurement approach that uses eight measurements, in combination, to answer four research questions regarding the physical and social effects that occur when a group of educable mentally retarded adolescents is exposed to a 10-week dance program. The findings revealed that four students showed improvement in both social and physical behaviors, seven students showed improvement in either social or physical behaviors, and two students showed no improvement. There was no evidence of a “transfer effect” due to participation in the program, and some students' behaviors were affected by external factors. The authors found the approach useful for identifying multiple effects and generating hypotheses for further study.  相似文献   
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In this paper, we identify appropriate statistical methods for analysing categorical differences in discrete variables or 'performance indicators' resulting from performance analysis. The random mechanisms associated with discrete events do not follow a normal distribution; that is, the normal distribution is a continuous not a discrete probability distribution. We propose appropriate statistical methods based on two key discrete probability distributions, the Poisson and binomial distributions. Two approaches are proposed and compared using examples from notational analysis. The first approach is based on the classic chi-square test of significance (both the goodness-of-fit test and the test of independence). The second approach adopts a more contemporary method based on log-linear and logit models fitted using the statistical software GLIM. Provided relatively simple one-way and two-way comparisons in categorical data are required, both of these approaches result in very similar conclusions. However, as soon as more complex models or higher-order comparisons are required, the approach based on log-linear and logit models is shown to be more effective. Indeed, when investigating those factors and categorical differences associated with binomial or binary response variables, such as the proportion of winners when attempting decisive shots in squash or the proportion of goals scored from all shots in association football, logit models become the only realistic method available. By applying log-linear and logit models to discrete events resulting from notational analysis, greater insight into the underlying mechanisms associated with sport performance can be achieved.  相似文献   
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