Physical fitness normative values for 6–18-year-old Greek boys and girls,using the empirical distribution and the lambda,mu, and sigma statistical method     

Konstantinos D. Tambalis  Demosthenes B. Panagiotakos  Glykeria Psarra  Stelios Daskalakis  Stavros A. Kavouras  Nickos Geladas 《European Journal of Sport Science》2016,16(6):736-746

The aim of the this study was to establish age- and gender-specific physical fitness normative values and to compare percentiles and Z scores values in a large, nationwide sample of Greek children aged 6–18 years. From March 2014 to May 2014, a total of 424,328 boys and girls aged 6–18 years who attended school in Greece were enrolled. The studied sample was representative, in terms of age–sex distribution and geographical region. Physical fitness tests (i.e. 20?m shuttle run test (SRT), standing long jump, sit and reach, sit-ups, and 10?×?5?m SRT) were performed and used to calculate normative values, using the percentiles of the empirical distributions and the lambda, mu, and sigma statistical method. Normative values were presented as tabulated percentiles for five health-related fitness tests based on a large data set comprising 424,328 test performances. Boys typically scored higher than girls on cardiovascular endurance, muscular strength, muscular endurance, and speed/agility, but lower on flexibility (all p values <0.001). Older boys and girls had better performances than younger ones (p?相似文献   

Perceived health problems in swimmers according to the chemical treatment of water in swimming pools     

Álvaro Fernández-Luna  Pablo Burillo  José Luis Felipe  Julio del Corral  Jorge García-Unanue  Leonor Gallardo 《European Journal of Sport Science》2016,16(2):256-265

The objective of this study was to determine which chemical treatment used for disinfecting water in indoor swimming pools had the least impact on users' perceptions of health problems, and which generated the greatest satisfaction with the quality of the water. A survey on satisfaction and perceived health problems was given to 1001 users at 20 indoor swimming pools which used different water treatment methods [chlorine, bromine, ozone, ultraviolet lamps (UV) and salt electrolysis]. The findings suggest that there is a greater probability of perceived health problems, such as eye and skin irritation, respiratory problems and skin dryness, in swimming pools treated with chlorine than in swimming pools using other chemical treatment methods. Pools treated with bromine have similar, although slightly better, results. Other factors, such as age, gender, time of day of use (morning and afternoon) and type of user (competitive and recreational), can also affect the probability of suffering health problems. For all of the above, using combined treatment methods as ozone and UV, or salt electrolysis produces a lower probability of perceived health problems and greater satisfaction.  相似文献   

Active recovery of the finger flexors enhances intermittent handgrip performance in rock climbers     

Jiří Baláš  David Giles  Jan Kodejška  Michaela Panáčková  Simon Fryer 《European Journal of Sport Science》2016,16(7):764-772

This study aimed to (1) evaluate the effect of hand shaking during recovery phases of intermittent testing on the time–force characteristics of performance and muscle oxygenation, and (2) assess inter-individual variability in the time to achieve the target force during intermittent testing in rock climbers. Twenty-two participants undertook three finger flexor endurance tests at 60% of their maximal voluntary contraction until failure. Performances of a sustained contraction and two intermittent contractions, each with different recovery strategies, were analysed by time–force parameters and near-infrared spectroscopy. Recovery with shaking of the forearm beside the body led to a significantly greater intermittent test time (↑ 22%, P?P?P?相似文献   

Momentum sequence and environmental climate influence levels of perceived psychological momentum within a sport competition     

Walid Briki  Keith D. Markman  Guillaume Coudevylle  Stéphane Sinnapah  Olivier Hue 《European Journal of Sport Science》2016,16(3):350-357

The present study examined the influence of momentum sequence (positive vs. negative) and environmental climate (hot–wet vs. neutral) on supporters’ (i.e. virtual observers’) reported levels of perceived psychological momentum (PM) during a simulated cycling competition. Participants supported one of two competing cyclists involved in a race that was displayed on a screen in a lecture hall. The race scenario was manipulated so that the supported cyclist appeared to undergo either a positive or negative momentum sequence. In addition, participants were either exposed to a hot–wet environmental climate or to a neutral environmental climate while observing the race scenario. According to the results, reported levels of PM were higher in the positive momentum sequence condition than in the negative momentum sequence condition, consistent with the notion that supporters’ PM is influenced by a positivity bias, and reported levels of PM were also found to be higher in the hot–wet climate condition than in the neutral climate condition, consistent with the notion that environmental climate is a contextual factor that influences PM through the operation of a causal augmenting mechanism.  相似文献   

#OscarsSoWhite: how Stuart Hall explains why nothing changes in Hollywood and everything is changing     

Isabel Molina-Guzmán 《Critical Studies in Media Communication》2016,33(5):438-454

ABSTRACT

Stuart Hall’s work on culture, representation, ideology and hegemony positions Hollywood as a cultural institution informed by and informative of US social values and norms. Thus contemporary debates over Hollywood's diversity are indicative of broader social conflicts. Empirically the article examines 2014–2015 news coverage of Hollywood to question the Hollywood paradox—the lack of diversity in film/TV production yet TV’s increasing shift towards on-screen diversity. It maps three discursive frames: Hollywood exceptionalism, economic imperatives, and institutionalized racism and sexism. The article concludes by using Hulu’s East Los High to reflect on TV’s digital turn and innovative models in production and representation.  相似文献   

The legacy of Nikola Tesla
The AC system that he helped to usher in     

D P Sen Gupta 《Resonance》2007,12(3):54-69

Alternating Current (AC) is used all over the world today. In India we use AC at 50 Hz (cycles per second) and in USA and Canada at 60 Hz. During the latter part of the 19th century, even during the early part of the 20th century, Direct Current or DC was widely used. Had we continued with DC, electricity would not have been as widely available as it is today and its use would have been cumbersome, costly and severely restricted. We owe it mainly to the Serbian genius Nikola Tesla that electricity has reached almost every nook and corner of most continents.  相似文献   

Sign and phonology     

Moores DF 《American annals of the deaf》2001,146(1):3-4

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无线移动数字图书馆系统中多媒体检索的同步模式     

党德鹏  周立柱 《上海大学学报(英文版)》2006,10(5):409-414

1IntroductionRecent advances in wireless communication,digitallibrary,distributed multi media,massive storage,andmobile computing technologies are sti mulating the de-velopment of mobile multi media digital library systems(M2DLS)that allow mobile clients to access multi me-dia material anywhere and anyti me over a cellular ra-dio network[1,2].In M2DLS,multi media objects,ingeneral,can be composed of multiple media streamssuch as audio and video,whose retrieval must proceedso as to not only …  相似文献   

Changing the Behavior of Behavior Changers     

John D. Krumboltz 《Counselor Education & Supervision》1967,6(Z3):222-229

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Academic socialization,parental educational expectations,and academic self‐efficacy among Latino adolescents     

Fernanda L. Cross  Aixa D. Marchand  Michael Medina  Andrea Villafuerte  Deborah Rivas‐Drake 《Psychology in the schools》2019,56(4):483-496

This study examined the direct association between parental educational expectations and adolescents’ academic self‐efficacy, as well as the moderating influence of parental academic socialization messages. Participants were 148 Latino parent–adolescent dyads with the majority of Mexican origin (80.4%). Most of the parent participants were mothers (85.8%). Adolescents were 13 (46%) or 14 (54%) years of age, and 53% identified as female. Adolescents reported their academic self‐efficacy and perceptions of their parents’ educational expectations; parents reported on their academic socialization messages of shame/pressure and effort regarding academics. The results suggest that, after accounting for parents’ level of education and immigrant status, parental educational expectations were positively associated with adolescent academic self‐efficacy. This association was stronger among adolescents whose parents reported transmitting fewer messages of shame/pressure and academic effort. These results point to the importance of nuances in the content and type of academic socialization messages within Latino families.  相似文献