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11.
The aim of this study was to examine work-time profiles, blood lactate concentrations and perceived exertion among Greco-Roman wrestlers in the 1998 World Championship. Forty-two senior wrestlers from nine nations were studied in 94 matches. Each match was recorded with a video camera (Panasonic AG 455, film rate: 25 Hz) and analysed for duration of work (wrestling) and rest (interrupt) periods. Blood lactate concentration was determined with an electrochemical device (Analox P-LM5) and a rating of perceived exertion scale (Borg) was used to estimate general exertion and exertion in the extremity and trunk muscles. The mean duration of the matches was 427 s (range 324-535 s), with mean durations of work and rest of 317 and 110 s, respectively. The mean periods of work and rest were 37.2 and 13.8 s, respectively. Mean blood lactate concentration was 14.8 mmol x 1(-1) (range 6.9-20.6). The difference in mean blood lactate concentration between the first- and final-round matches was not significant (P > 0.05). Blood lactate concentration was significantly higher (P < 0.04) in matches of long duration than in those of short duration. The mean general rating of perceived exertion for all matches was 13.8 according to the scale used. Most of the wrestlers (53.3%) perceived exertion to be highest in the flexors of the forearm, followed by the deltoids (17.4%) and the biceps brachii muscles (12.0%). In addition to a relatively high rating of perceived exertion in the arm muscles, this indicates a high specific load on the flexor muscles of the forearm. 相似文献
12.
Luca Paolo Ardigò Johnny Padulo Andrea Zuliani Carlo Capelli 《Journal of sports sciences》2015,33(17):1853-1858
This study aimed to apply a validated bioenergetics model of sprint running to recordings obtained from commercial basic high-sensitivity global positioning system receivers to estimate energy expenditure and physical activity variables during soccer refereeing. We studied five Italian fifth division referees during 20 official matches while carrying the receivers. By applying the model to the recorded speed and acceleration data, we calculated energy consumption during activity, mass-normalised total energy consumption, total distance, metabolically equivalent distance and their ratio over the entire match and the two halves. Main results were as follows: (match) energy consumption = 4729 ± 608 kJ, mass normalised total energy consumption = 74 ± 8 kJ · kg?1, total distance = 13,112 ± 1225 m, metabolically equivalent distance = 13,788 ± 1151 m and metabolically equivalent/total distance = 1.05 ± 0.05. By using a very low-cost device, it is possible to estimate the energy expenditure of soccer refereeing. The provided predicting mass-normalised total energy consumption versus total distance equation can supply information about soccer refereeing energy demand. 相似文献
13.
Edward P. St. John Sandra Andrieu Jeffrey Oescher Johnny B. Starkey 《Research in higher education》1994,35(4):455-480
This paper uses the 1987 National Postsecondary Student Aid Study to compare five alternative approaches for assessing the
influence of student aid on within-year persistence by traditional college-age students enrolled in four-year colleges. Three
conclusions were drawn from the research. First, models that included tuition charges better predicted within-year persistence
than models that did not include this independent variable. Second, the use of multiple approaches for measuring the influence
of student aid provided more insight into the ways student aid policies influence persistence than any single approach. Third,
tuition charges had a consistent negative influence on persistence. 相似文献
14.
A specialized method is presented for listing all the spinning trees of the wheel, homeomorphs of the wheel, and certain cellular arrays. The procedure is a generalization of a known method of enumerating the trees of a suitably labeled ladder graph, and results in a direct listing of the trees with no duplications and no extraneous subgraphs. 相似文献
15.
When the assumption of multivariate normality is violated or when a discrepancy function other than (normal theory) maximum likelihood is used in structural equation models, the null distribution of the test statistic may not be χ2 distributed. Most existing methods to approximate this distribution only match up to 2 moments. In this article, we propose 2 additional approximation methods: a scaled F distribution that matches 3 moments simultaneously and a direct Monte Carlo–based weighted sum of i.i.d. χ2 variates. We also conduct comprehensive simulation studies to compare the new and existing methods for both maximum likelihood and nonmaximum likelihood discrepancy functions and to separately evaluate the effect of sampling uncertainty in the estimated weights of the weighted sum on the performance of the approximation methods. 相似文献
16.
Emerson Hicks Bunnell Lee R. Baker Johnny Minus William Storm Hale 《Communication Booknotes Quarterly》2013,44(9):8-10
Emerson, Naturalistic Photography for Students of the Art (1891) Hicks, Words and Pictures: Introduction to Photojournalism (1952) Bunnell, Nonsilver Printing Processes, $4.50 Lee R. Baker, Making Movies: From Script to Screen (New York: Harcourt Brace Javanovich, 1973—price not known, paper) Johnny Minus and William Storm Hale's Your Introduction to Film-TV Copyright, Contracts and other Law (Seven Arts Press, 6655 Hollywood Blvd., Hollywood, Ca. 90028 1973— $10.00 paper) Noel Burch Theory of Film Practice (New York: Praeger, 1973—$8.95) Hector Currie and Donald Staples' Film: Encounter (Dayton, Ohio: Pflaum/Standard, 1973—$9.95, paper) John G. Cawelti's Focus on Bonnie and Clyde (Englewood Cliffs, N.J.: Prentice-Hall, 1973—$5.95/2.45) David Bordwell, Filmguide to La Passion de Jeanne d'Arc Warren French, Filmguide to The Grapes of Wrath Carolyn Geduld, Filmguide to 2001: A Space Odyssey James Naremore, Filmguide to Psycho E. Rubenstein, Filmguide to The General Jay Leyda's Kino: A History of the Russian and Soviet Film (New York: Collier Books, 1973 reissue of 1960 original —$4.95, paper) 相似文献
17.
Johnny Hartz Søraker 《The Information Society》2013,29(1):40-46
The increasing use of frameworks within which Internet users can contribute nontextual information constitutes a serious obstacle to government attempts to accurately censor and monitor Internet traffic. This development, as seen in the explosive growth of frameworks such as Second Life, YouTube, and Wikipedia, could lead to a transfer of regulatory power away from heavily regulated Internet Service Providers in nondemocratic regimes, into the hands of intermediaries that are more likely to uphold freedom of expression. Thereby, a development toward increasingly enframed and nontextual information can promote freedom of expression even in traditionally nondemocratic regimes. I analyze this development with regard to its possible implications for freedom of expression, online crime, and the role of private companies in international politics. 相似文献
18.
Johnny Nilsson Sandor Csergö Lennart Gullstrand Per Tveit Per Egil Refsnes 《Journal of sports sciences》2013,31(11):939-945
The aim of this study was to examine work-time profiles, blood lactate concentrations and perceived exertion among Greco-Roman wrestlers in the 1998 World Championship. Forty-two senior wrestlers from nine nations were studied in 94 matches. Each match was recorded with a video camera (Panasonic AG 455, film rate: 25 Hz) and analysed for duration of work (wrestling) and rest (interrupt) periods. Blood lactate concentration was determined with an electrochemical device (Analox P-LM5) and a rating of perceived exertion scale (Borg) was used to estimate general exertion and exertion in the extremity and trunk muscles. The mean duration of the matches was 427 s (range 324-535 s), with mean durations of work and rest of 317 and 110 s, respectively. The mean periods of work and rest were 37.2 and 13.8 s, respectively. Mean blood lactate concentration was 14.8 mmol · l -1 (range 6.9-20.6). The difference in mean blood lactate concentration between the first- and final-round matches was not significant ( P > 0.05). Blood lactate concentration was significantly higher ( P ? 0.04) in matches of long duration than in those of short duration. The mean general rating of perceived exertion for all matches was 13.8 according to the scale used. Most of the wrestlers (53.3%) perceived exertion to be highest in the flexors of the forearm, followed by the deltoids (17.4%) and the biceps brachii muscles (12.0%). In addition to a relatively high rating of perceived exertion in the arm muscles, this indicates a high specific load on the flexor muscles of the forearm. 相似文献
19.
Antonio Dello Iacono Johnny Padulo Laurent D Seitz 《Journal of sports sciences》2018,36(11):1269-1276
This study aimed to investigate the acute effects of two barbell hip thrust-based (BHT) post-activation potentiation (PAP) protocols on subsequent sprint performance. Using a crossover design, eighteen handball athletes performed maximal 15-m sprints before and 15s, 4min and 8min after two experimental protocols consisting of BHT loaded with either 50% or 85% 1RM (50PAP and 85PAP, respectively), in order to profile the transient PAP effects. The resulting sprint performances were significantly impaired at 15s only after the 85PAP protocol, which induced likely and very likely greater decreases compared to the 50PAP. At 4min and 8min, significant improvements and very likely beneficial effects were observed in the 10m and 15m performances following both protocols. Significant differences were found when comparing the two PAPs over time; the results suggested very likely greater performance improvements in 10m following the 85PAP after 4min and 8min, and possible greater performance improvements in 15m after 4min. Positive correlations between BHT 1RMs values and the greatest individual PAP responses on sprint performance were found. This investigation showed that both moderate and intensive BHT exercises can induce a PAP response, but the effects may differ according to the recovery following the potentiating stimulus and the individual`s strength level. 相似文献
20.
Alessandro M. Zagatto Fabio Y. Nakamura Fabio Milioni Willian E. Miyagi Rodrigo A. B. de Poli Johnny Padulo 《Journal of sports sciences》2017,35(24):2453-2460
The purpose of the study was to investigate the sensitivity of an alternative maximal accumulated oxygen deficit (MAODALT) method to discriminate the “anaerobic” capacity while comparing: least trained (LT) participants (n = 12), moderately trained (MT) participants (n = 12), endurance trained (ET) participants (n = 16), and rugby (RG) players (n = 11). Participants underwent a graded exercise test on a treadmill and a supramaximal effort for assessing MAODALT. MAODALT was calculated as the sum of oxygen equivalents from the phosphagen and glycolytic metabolic pathways. MAODALT was significantly higher (P < 0.05) in RG (64.4 ± 12.1 mL · kg?1) than in ET (56.8 ± 5.4 mL · kg?1; effect size [ES] = 0.77; +13.5%), MT (53.8 ± 5.3 mL · kg?1; ES = 1.08; +19.8%), and LT (49.9 ± 4.5 mL · kg?1; ES = 1.50; +36.4%). In addition, the magnitude-based inference analysis revealed that MAODALT was likely (LT vs. MT), very likely (MT vs. RG, and ET vs. RG) and most likely (LT vs. ET, and LT vs. RG) different between all groups, except for MT and ET, which presented an unclear difference. In conclusion, MAODALT was sensitive enough to distinguish the “anaerobic” capacity in individuals with different training status, especially for RG players compared with LT participants and MT participants. 相似文献