Effect of loading on peak power of the bar,body, and system during power cleans,squats, and jump squats

Abstract

Nine males (age 24.7 ± 2.1 years, height 175.3 ± 5.5 cm, body mass 80.8 ± 7.2 kg, power clean 1-RM 97.1 ± 6.36 kg, squat 1-RM = 138.3 ± 20.9 kg) participated in this study. On day 1, the participants performed a one-repetition maximum (1-RM) in the power clean and the squat. On days 2, 3, and 4, participants performed the power clean, squat or jump squat. Loading for the power clean ranged from 30% to 90% of the participant's power clean 1-RM and loading for the squat and jump squat ranged from 0% to 90% of the participant's squat 1-RM, all at 10% increments. Peak force, velocity, and power were calculated for the bar, body, and system (bar + body) for all power clean, squat, and jump squat trials. Results indicate that peak power for the bar, body, and system is differentially affected by load and movement pattern. When using the power clean, squat or jump squat for training, the optimal load in each exercise may vary. Throwing athletes or weightlifters may be most concerned with bar power, but jumpers or sprinters may be more concerned with body or system power. Thus, the exercise type and load vary according to the desired stimulus.     

Emphasizing the History of Genetics in an Explicit and Reflective Approach to Teaching the Nature of Science

Science education researchers have long advocated the central role of the nature of science (NOS) for our understanding of scientific literacy. NOS is often interpreted narrowly to refer to a host of epistemological issues associated with the process of science and the limitations of scientific knowledge. Despite its importance, practitioners and researchers alike acknowledge that students have difficulty learning NOS and that this in part reflects how difficult it is to teach. One particularly promising method for teaching NOS involves an explicit and reflective approach using the history of science. The purpose of this study was to determine the influence of a historically based genetics unit on undergraduates’ understanding of NOS. The three-class unit developed for this study introduces students to Mendelian genetics using the story of Gregor Mendel’s work. NOS learning objectives were emphasized through discussion questions and investigations. The unit was administered to undergraduates in an introductory biology course for pre-service elementary teachers. The influence of the unit was determined by students’ responses to the SUSSI instrument, which was administered pre- and post-intervention. In addition, semi-structured interviews were conducted that focused on changes in students’ responses from pre- to post-test. Data collected indicated that students showed improved NOS understanding related to observations, inferences, and the influence of culture on science.     

The role of question type and reading ability in reading comprehension

Performance on a standardized reading comprehension test reflects the number of correct answers readers select from a list of alternate choices, but fails to provide information about how readers cope with the various cognitive demands of the task. The aim of this study was to determine whether three groups of readers: normally achieving (NA), poor comprehenders (CD), with no decoding disability, and reading disabled (RD), poor comprehenders with poor decoding skills, differed in their ability to cope with reading comprehension task demands. Three task variables reflected in the question-answer relations that appear on standardized reading comprehension tests were identified.Passage Independent (PI) question can be answered with reasonable accuracy based on the reader's prior knowledge of the passage content.Inference (INFER) questions required the reader to generate an inference at the local or global test level.Locating (LOCAT) questions require the reader to match the correct answer choice to a detail explicitly stated in the text either verbatim or in paraphrase form. The relations among reader characteristics, cognitive task factors and reading comprehension test scores were analyzed using a structural relations equation with LISREL. It was found that the three reading groups differed with respect to the underlying relationship between their performance on specific question-answer types and their standardized reading comprehension score. For the NA group, a high score on PI was likely to be accompanied by a low score on INFER, whereas in the CD and RD groups, PI and INFER are positively related. The finding of a negative relationship between background knowledge and inference task factors for normally achieving readers suggests that even normal readers may have comprehension difficulties that go undetected on the basis of a standardized scores. This study indicates that current comprehension assessments may not be adequate for assessing specific reading difficulties and that more precise diagnostic tools are needed.     

Physical discipline and children's adjustment: cultural normativeness as a moderator

Interviews were conducted with 336 mother-child dyads (children's ages ranged from 6 to 17 years; mothers' ages ranged from 20 to 59 years) in China, India, Italy, Kenya, the Philippines, and Thailand to examine whether normativeness of physical discipline moderates the link between mothers' use of physical discipline and children's adjustment. Multilevel regression analyses revealed that physical discipline was less strongly associated with adverse child outcomes in conditions of greater perceived normativeness, but physical discipline was also associated with more adverse outcomes regardless of its perceived normativeness. Countries with the lowest use of physical discipline showed the strongest association between mothers' use and children's behavior problems, but in all countries higher use of physical discipline was associated with more aggression and anxiety.     

Social anxiety in learning: stages of change in a sample of UK undergraduates

Social anxiety in learning is prevalent amongst traditional-age students and has a marked effect on their engagement with higher education. It receives little attention from academic or support services and there is a presumption that students will manage their anxieties. Yet it is unclear what psychosocial resources they might bring to this task and how these may develop through the undergraduate years. This study sought to identify possible change processes in student social anxiety by analysing qualitative responses obtained from Level 2 undergraduate students (n=39) in relation to their experience of learning situations such as lectures, seminars and group presentations. Thematic analysis suggested a four-stage developmental progression for students in terms of their experience and orientation to coping with social anxiety. Implications for staff development and student support are outlined.     

A Trial of the Five Es: A Referent Model for Constructivist Teaching and Learning

The science and technology education literature indicates that teaching within a constructivist paradigm is an effective way to promote student learning. Despite this, most primary school teachers do not use constructivist theoretical approaches because they are perceived as difficult and impractical to implement. To promote constructivist teaching and learning approaches in schools, teachers need access to models and strategies they can implement effectively and with relative ease. A unit of work was developed, based on the Five Es model (Engagement, Exploration, Explanation, Elaboration and Evaluation), and taught to a year 3 class. Ten students were participants in the study and became the sample. Data were analysed using two different methods to compare and validate findings. The unit of work, based on the Five Es model, was found to be interesting and fun by students, and motivated student learning and promoted student higher-order thinking.     

Caught between a rock and a hard place: disruptive boys’ views on mainstream and special schools in New South Wales,Australia

Students with disruptive behaviour in the Australian state of New South Wales (NSW) are increasingly being educated in separate ‘behaviour’ schools. There is however surprisingly little research on how students view these settings, or indeed the mainstream schools from which they were excluded. To better understand excluded students’ current and past educational experiences, we interviewed 33 boys, aged between 9 and 16 years of age, who were enrolled in separate special schools for students with disruptive behaviour. Analyses reveal that the majority of participants began disliking school in the early years due to difficulties with schoolwork and teacher conflict. Interestingly, while most indicated that they preferred the behaviour school, more than half still wanted to return to their old school. It is therefore clear that separate special educational settings are not a solution to disruptive behaviour in mainstream schools. Whilst these settings do fulfil a function for some students, the preferences of the majority of boys suggest that ‘mainstream’ school reform is of first-order importance.     

What do students want most from written feedback information? Distinguishing necessities from luxuries using a budgeting methodology

Feedback is a key concern for higher education practitioners, yet there is little evidence concerning the aspects of assessment feedback information that higher education students prioritise when their lecturers’ time and resources are stretched. One recent study found that, in such circumstances, students actually perceive feedback information itself as a luxury rather than a necessity. We first re-examined that finding by asking undergraduates to ‘purchase’ characteristics to create the ideal lecturer, using budgets of differing sizes to distinguish necessities from luxuries. Contrary to the earlier research, students in fact considered good feedback information the single biggest necessity for lecturers to demonstrate. In a second study, we used the same method to examine the characteristics of feedback information that students value most. Here, the most important perceived necessity was guidance on improvement of skills. In both studies, students’ priorities were influenced by their individual approaches to learning. These findings permit a more pragmatic approach to building student satisfaction in spite of growing expectations and demands.     

F. Memoirs and Biography

ON TELEVISION by Pierre Bourdieu, translated from the 1996 French original by Priscilla Ferguson (New York: The New Press, 1998—$18.95, paper, ISBN 1–56584–407–6, 104 pp., appendix, translator's note, bibliography, notes, index)

BUYER'S GUIDE TO FIFTY YEARS OF TV ON VIDEO by Sam Frank (Amherst, NY: Prometheus Books, 1999—$22.95, paper, ISBN 1–57392–226–9, 1,498 pp., index)

THE TELEVISION STUDIES BOOK edited by Christine Geraghty and David Lusted (London: Arnold / New York: St. Martin's Press, 1998—$59.95/18.95, ISBN 0–340–66232 hard, 0–340–66231‐X paper, 337 pp., index)

WHY WE WATCH: THE ATTRACTIONS OF VIOLENT ENTERTAINMENT edited by Jeffrey H. Goldstein (New York: Oxford University Press, 1998—$49.95/17.95, ISBN 0–19–511820–0 hard, 0–19–511821–9 paper, 270 pp., illustrations, references, subject and name indexes)

BROADCASTING IN AMERICA: A SURVEY OF ELECTRONIC MEDIA by S. W. Head, C. H. Sterling, L. B. Schofield, T. Spann, and M. A. McGregor (Boston: Houghton Mifflin, 1998 [8th ed.]—$52.00, paper, ISBN 0–395–87371–1, 337 pp., 280 photos &; graphics, bibliography, index, instructor's manual)

PRIME TIME LAW: FICTIONAL TELEVISION AS LEGAL NARRATIVE edited by Robert M. Jarvis and Paul R. Joseph (Durham, NC: Carolina Academic Press, 1998—price not given, ISBN 0–89089–805–7 hard, 0–89089–808–1 paper, 323 pp., notes, index)

MASTERPIECE THEATRE AND THE POLITICS OF QUALITY by Lawrence A. Jarvik (Lanham, MD: Scarecrow Press, 1999—$60.00, ISBN 0–8108–3204–6, 261 pp., notes, bibliography, index)

TELEVISION VIOLENCE: A GUIDE TO THE LITERATURE edited by P.T. Kelly (Nova Science Publishers, 6080 Jericho Turnpike, Suite 207, Commack, NY 11725—price not given, ISBN 1–56072–299–1, 193 pp., index)

UNDERSTANDING SOCIETY, CULTURE, AND TELEVISION by Paul Monaco (Westport, CT: Praeger, 1998—$55.00, ISBN 0–275–96057–9, 152 pp., bibliography, index)

ENCYCLOPEDIA OF TELEVISION NEWS edited by Michael D. Murray (Phoenix: Oryx Press, 1999—price not given, ISBN 1–57356–108–8, 315 pp., photos, further reading, index)

STUDENT TELEVISION IN AMERICA: CHANNELS OF CHANGE by Tony Silvia and Nancy F. Kaplan (Ames, IA: Iowa State University Press, 1998— $29.95, paper, ISBN 0–8138–2160–6, 243 pp., illustrations, selected bibliography, appendixes, index)

LIVING COLOR: RACE AND TELEVISION IN THE UNITED STATES edited by Sasha Torres (Durham, NC: Duke University Press, 1998—$49.95/17.95, ISBN 0–8223–2178–5 hard, 0–8223–2195–5 paper, illustrations, selected bibliography, index)