Reference     

John Schmittroth Jr.  Martin Connors  Roberto Valdez  Elena Pernia  W.H. Wallace  M. Gordon 《Communication Booknotes Quarterly》2013,44(9):93-95

TELECOMMUNICATIONS SYSTEMS AND SERVICES DIRECTORY —ISSUE TWO, edited by John Schmittroth Jr. and Martin Connors (Detroit, Mich.: Gale Research, 1984--$170.00 for the first edition, being issued in three parts, paper)

THE BOOK PUBLISHING ANNUAL: HIGHLIGHTS, ANALYSES & TRENDS (New York: R.R. Bowker, 1984---$49.95)

THE COMPUTER AND BUSINESS EQUIPMENT INDUSTRY MARKETING DATA BOOK (Computer and Business Equipment Manufacturers Association, 311 First Street, N.W., Washington, D.C. 20001--price not given, paper)

THE SOCIAL AND ECONOMIC IMPACT OF VIDEOTEX, TELETEXT AND COMPUTERS: AN ANNOTATED BIBLIOGRAPHY, by Roberto Valdez, et al., and THE SOCIAL AND ECONOMIC IMPACT OF TELEPHONES by Elena Pernia, et al. (Honolulu, Hi.: East-West Center, 1984--price not given, but cost covers reproduction and postage, paper)

WHAT'S IN PRINT: THE SUBJECT GUIDE TO MICROCOMPUTER MAGAZINES, by W.H. Wallace (Blue Ridge Summit, Pennsylvania: TAB Books, 1984--price not given, paper)

DICTIONARY OF NEW INFORMATION TECHNOLOGY ACRONYMS, by M. Gordon, et al. (London: Kogan Page/Detroit: Gale Research, 1984--$56.00)

THE VIDEOTEX MARKETPLACE (Bethesda, Md.: Phillips Publishing, 1984--$97.00, paper)

A VIDEOTEX/TELETEXT BIBLIOGRAPHY (Videotex Industry Association, 1901 Ft. Myer Drive, Suite 200, Rosslyn, VA 22209--$25.00, paper)

AUDIO VIDEO MARKET PLACE: A MULTIMEDIA GUIDE 1984 (New York: R.R. Bowker, 1984--$45.00 paper)

THE INTERACTIVE CABLE TV HANDBOOK (Bethesda, Md.: Phillips Publishing, 1984--$97.00, paper)

COMPUTERIZED LITERATURE SEARCHING: RESEARCH STRATEGIES AND DATABASES, by Charles L. Gilreath (Boulder, Colo.: Westview, 1984--$25.00)  相似文献   

Landing techniques in volleyball     

Roberto Lobietti  Simon Coleman  Eduardo Pizzichillo  Franco Merni 《Journal of sports sciences》2013,31(13):1469-1476

Abstract

Knee injuries such as anterior cruciate ligament lesions and patellar tendonitis are very frequent in volleyball, and are often attributed to micro traumas that occur during the landing phase of airborne actions. The aim of the present study was to compare different jumping activities during official men's and women's volleyball games. Twelve top-level matches from the Italian men's and women's professional leagues were analysed. The jumps performed during the games were classified according to the landing technique used by the player (left or right foot or both feet together), court position, and ball trajectory. Chi-square analyses were performed to detect differences in landing techniques between the sexes, court positions, and trajectories when serving, attacking, blocking, and setting. Significant differences (P < 0.05) were found between the sexes for block, set, and spike but not for the jump serve. The frequency of landings on one foot was related to court position and the trajectory of the sets: when spiking faster sets, the players were more likely to use a one-footed landing. The present results should help coaches and physiotherapists to devise appropriate training and prevention programmes, and reveal the need for further detailed biomechanical investigations of the relationships between landings and knee injuries.  相似文献   

Estimation of teacher practices based on text transcripts of teacher speech using a support vector machine algorithm     

Roberto Araya  Francisco Plana  Pablo Dartnell  Jorge Soto‐Andrade  Gina Luci  Elena Salinas  Marylen Araya 《British journal of educational technology : journal of the Council for Educational Technology》2012,43(6):837-846

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On the Wrong Side of the Tracks: Understanding the Effects of School Structure and Social Capital in the Educational Pursuits of Undocumented Immigrant Students     

Roberto G. Gonzales 《Peabody Journal of Education》2013,88(4):469-485

Over the last few years, increasing scholarly and media attention has been paid to the plight of undocumented immigrant college students. However, only a small fraction of undocumented youth actually moves on from high school to postsecondary opportunities. Indeed, the exclusion from financial aid eligibility and low family socioeconomic status severely limit undocumented students’ ability to matriculate to institutions of higher learning. But little is known about the ways in which school experiences shape postsecondary outcomes. This article focuses on the high school experiences of a sample of undocumented young adults and examines the ways in which school structures shape access to resources needed for postsecondary matriculation. In doing so, I argue that school-based networks are critical for success. However, these networks are fundamentally shaped by the school structure. This article draws from 78 in-depth life histories of undocumented Latino young adults in the Los Angeles metropolitan area. I incorporate a sample, stratified by educational experiences. The lived experiences of these young adults shed important light on the broader world in which they live and the ways in which immigration policies interact with school practices to shape success and failure.  相似文献   

The Short-Term Effects of a Computer-Based Pregnancy,STD, and HIV Prevention Program     

Anthony J. Roberto  Kellie E. Carlyle  Rick S. Zimmerman  Erin L. Abner  Pamela K. Cupp  Gary L. Hansen 《Communication quarterly》2013,61(1):29-48

A computer- and Internet-based intervention was designed to influence several variables related to the prevention of pregnancy, STDs, and HIV in rural adolescents. Three-hundred and thirty-eight tenth-graders enrolled in two rural public high schools participated in this field experiment. Results indicate that students in the experimental school had greater knowledge, greater condom negotiation efficacy, greater situational efficacy, and more favorable attitudes toward waiting to have sex than students in the control school. In tandem, the results suggest that computer-based programs may be a cost-effective and easily replicable means of providing teens with basic information and skills necessary to prevent pregnancy, STDs, and HIV.  相似文献   

Prevalence and Predictors of Cyberbullying Perpetration by High School Seniors     

Anthony J. Roberto  Jen Eden  Matthew W. Savage  Leslie Ramos-Salazar  Douglas M. Deiss 《Communication quarterly》2013,61(1):97-114

Cyberbullying is the deliberate and repeated misuse of communication technology by an individual or group to threaten or harm others. Guided largely by the communication skills deficiency model and previous research on cyberbullying, this study examins the effects of several predictor variables (i.e., verbal aggression, sex, risky behaviors, parental monitoring, parental limits, technology use, and scope of Internet activities) on cyberbullying perpetration. A total of 1,606 incoming freshmen at a large southwestern university completed an online survey measuring all predictor and dependent variables under investigation. Overall, 35% of these individuals reported that they had cyberbullied at least one person during their senior year of high school. Results indicated that verbal aggression, risky behaviors, and cyberbullying victimization emerged as significant predictors of cyberbullying perpetration. These results have important theoretical and practical implications for those interested in developing cyberbullying prevention interventions.  相似文献   

Physiological and anthropometric characteristics of top-level youth cross-country cyclists     

Alessandro Fornasiero  Aldo Savoldelli  Roberto Modena  Gennaro Boccia  Barbara Pellegrini  Federico Schena 《Journal of sports sciences》2018,36(8):901-906

In the literature there is a lack of data about the development of top level athletes in cross-country mountain biking (XCO). The purpose of this study was to analyze anthropometric and physiological characteristics of some of the best XCO bikers aged between 13 and 16. The study involved 45 bikers (26 males and 19 females) belonging to a youth national team. The evaluations, consisting of anthropometric measures, incremental cycling tests (VO_2max, PPO, P@RCP), and 30 s Wingate Tests (PMax, PMean), were conducted over a lapse of 4 years. Our findings showed in bikers, already at young age, a specific athletic profile advantageous for XCO performance. At the age of 16, just before entering the junior category and competing at international level, male and female bikers showed physiological values normalized to the body mass comparable to those reported in literature for high level athletes (VO_2max>70 and >60 ml/kg/min, PPO >6.5 and >5.5 W/kg, respectively in males and females). The production of high power-to-weight ratios and high peaks of anaerobic power attests the presence of highly developed aerobic and anaerobic systems in young XCO cyclists reflecting the high physiological demand of this sport.  相似文献   

Growth,functional capacities and motivation for achievement and competitiveness in youth basketball: an interdisciplinary approach     

Humberto Moreira Carvalho  Carlos E Gonçalves  Dave Collins  Roberto R Paes 《Journal of sports sciences》2018,36(7):742-748

The interaction of multiple influences on the path to sport success is not yet fully understood by sport scientists. In this study, we examined variation in body size, functional capacities and motivation for achievement, competitiveness and deliberate practice of youth basketball players associated with differences in biological maturity status, chronological age and years of training experience. Reflecting the importance of interactive effects, we examined the relationships between the psychological variables and functional capacities. Fifty-eight male basketball players aged 9.5 to 15.5 years were considered. Variables included chronological age, estimated age at peak height velocity, stature, body mass and sitting height by anthropometry; the Work and Family Orientation and Deliberate Practice Motivation Questionnaires were also used. Finally, the Line Drill test and Yo-Yo Intermittent Recovery level 1 (Yo-Yo IR1) tests were used as functional capacities indicators for basketball. Variance components models derived from series of multilevel linear regression models revealed a substantial variation by maturity status for body size, functional capacities indicators, mastery and will to excel. The influence of estimated maturity status on mastery and will to excel was independent of age and years of experience. In contrast, no relationships were observed between psychological variables and functional capacities indicators. We conclude that growth-related changes are relevant to understanding players´ motivations for achievement, competitiveness and deliberate practice. This should be of interest to those involved in the selection and development of youth basketball players.  相似文献   

Effects of resistance training in HIV-infected patients: A meta-analysis of randomised controlled trials     

Roberto Poton  Marcos Polito  Paulo Farinatti 《Journal of sports sciences》2017,35(24):2380-2389

The relative effects of resistance training (RT) upon muscle fitness and immune function among HIV-infected patients are uncertain. The purpose of this study was to perform a meta-analysis to determine the effects of RT upon muscle strength, muscle mass and CD4 cells count and to identify potential moderators of those outcomes in HIV-infected patients. Meta-analyses use random or fixed-effects model depending on the heterogeneity of effect sizes, complemented with Hedge’s g correction factor. Thirteen trials were meta-analysed. Overall, RT increased muscle strength (35.5%, P < 0.01) and CD4 cell count (26.1%, P = 0.003) versus controls (P < 0.03), but not muscle mass (P = 0.051). Meta-regression followed by subgroup moderator analysis showed that gains in muscle strength followed a dose–response pattern with largest increase detected among trials with longer (24 weeks; 49.3%) than shorter intervention (<12 weeks; 39%), higher (Physiotherapy Evidence-Based Database [PEDro] scale = 6; 38.3%) than lower (PEDro = 5; 28.1%) quality, and longer (12 months; 59.7%) than shorter time under highly active antiretroviral therapy (HAART) (<6 months; 37.1%), (P < 0.01). RT appears to be efficacious to improve muscular strength (~35.5%) and CD4 cell count (~26.1%), but not muscle mass of HIV-infected patients. Effects upon strength were greater in studies with higher quality and among trials with longer RT and HAART.  相似文献   

Induced beliefs about a fictive energy drink influences 200-m sprint performance†     

Ricardo de la Vega  Sara Alberti  Roberto Ruíz-Barquín  István Soós 《European Journal of Sport Science》2017,17(8):1084-1089

Placebo and nocebo effects occur in response to subjective expectations and their subsequent neural actions. Research shows that information shapes expectations that, consequently, influence people’s behaviour. In this study, we examined the effects of a fictive and inert green colour energy drink provided for three groups (n?=?20/group) with different information. The first group was led to expect that the drink augments running performance (positive information), the second group was led to expect that the drink may or may not improve performance (partial-positive information), while the third group was told that earlier research could not demonstrate that the drink improves performance (neutral/control). At baseline, the three groups did not differ in their 200-m sprint performance (p?>?.05). One week later, 20-min immediately after ingesting the drink, all participants again ran 200?m. The positive information group increased its performance by 2.41?s, which was statistically significant (p?<?.001) and also perceived its sprint-time shorter (p?<?.05) than the other two groups. A better performance (0.97?s) that approached but did not reach statistical significance was also noted in the partial-positive information group, and a lesser change (0.72?s) that was statistically not significant was noted in the neutral information control group. These results reveal that drinking an inert liquid, primed with positive information, changes both the actual and the self-perceived time on a 200-m sprint. The current findings also suggest that the level of certainty of the information might be linked to the magnitude of change in performance.  相似文献