Circadian rhythm effect on physical tennis performance in trained male players

To determine the effect of circadian rhythm on neuromuscular responses and kinematics related to physical tennis performance, after a standardised warm-up, 13 highly competitive male tennis players were tested twice for serve velocity/accuracy (SVA), countermovement vertical jump (CMJ), isometric handgrip strength (IS), agility T-test (AGIL) and a 10-m sprint (10-m RUN). In a randomised, counter-balance order, tennis players underwent the test battery twice, either in the morning (i.e., AM; 9:00 h) and in the afternoon (i.e., PM; 16:30 h). Paired t-tests were used to analyse differences due to time-of-day in performance variables. Comparison of morning versus afternoon testing revealed that SVA (168.5 ± 6.5 vs. 175.2 ± 6.1 km · h^?1; P = 0.003; effect size [ES] = 1.07), CMJ (32.2 ± 0.9 vs. 33.7 ± 1.1 cm; P = 0.018; ES = 1.46), AGIL (10.14 ± 0.1 vs. 9.91 ± 0.2 s; P = 0.007; ES = 1.23) and 10-m RUN time (1.74 ± 0.1 vs. 1.69 ± 0.1 s; P = 0.021; ES = 0.67) were significantly blunted during the morning testing. However, IS was not affected by time-of-day (P = 0.891). Thus, tennis performance may be reduced when competing in the morning in comparison to early evening. Therefore, coaches and tennis players should focus on schedule the SVA, power, speed and agility training sessions in the afternoon.     

Teaching future teachers basic astronomy concepts—seasonal changes—at a time of reform in science education

Bearing in mind students' misconceptions about basic concepts in astronomy, the present study conducted a series of constructivist activities aimed at changing future elementary and junior high school teachers' conceptions about the cause of seasonal changes, and several characteristics of the Sun–Earth–Moon relative movements like Moon phases, Sun and Moon eclipses, and others. The activities and results concerning the cause of seasonal changes are reported. Both the experimental class and the control groups improved their grasp of basic astronomy concepts statistically significantly, although the experimental class made the most impressive progress of all. Regarding subjects relevant to this study (seasonal changes), only the experimental class showed a statistically significant improvement, which justifies the constructivist approach. We conclude that in implementing a reform in the science curriculum, the change has to include the subjects taught and also the way they are taught. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 879–906, 2006     

Identifying top relevant dates for implicit time sensitive queries

Despite a clear improvement of search and retrieval temporal applications, current search engines are still mostly unaware of the temporal dimension. Indeed, in most cases, systems are limited to offering the user the chance to restrict the search to a particular time period or to simply rely on an explicitly specified time span. If the user is not explicit in his/her search intents (e.g., “philip seymour hoffman”) search engines may likely fail to present an overall historic perspective of the topic. In most such cases, they are limited to retrieving the most recent results. One possible solution to this shortcoming is to understand the different time periods of the query. In this context, most state-of-the-art methodologies consider any occurrence of temporal expressions in web documents and other web data as equally relevant to an implicit time sensitive query. To approach this problem in a more adequate manner, we propose in this paper the detection of relevant temporal expressions to the query. Unlike previous metadata and query log-based approaches, we show how to achieve this goal based on information extracted from document content. However, instead of simply focusing on the detection of the most obvious date we are also interested in retrieving the set of dates that are relevant to the query. Towards this goal, we define a general similarity measure that makes use of co-occurrences of words and years based on corpus statistics and a classification methodology that is able to identify the set of top relevant dates for a given implicit time sensitive query, while filtering out the non-relevant ones. Through extensive experimental evaluation, we mean to demonstrate that our approach offers promising results in the field of temporal information retrieval (T-IR), as demonstrated by the experiments conducted over several baselines on web corpora collections.     

A Bibliometric Analysis of High Impact Research in the Middle East Using Champion Works

Increasing political and financial support for scientific research in the Middle East requires academic and research communities in the region to demonstrate the visibility and impact of their scientific output. However, for countries with smaller scientific communities or lack of detailed information on their scientific production, the use of common metrics of scientific impact (e.g., number of papers, impact factor, h-index, etc.) may fail to reveal their true ability to produce high quality research, and thus guarantee the wanted societal support. In such cases, identifying and highlighting outstanding papers produced by national institutions or scientists may be another way to demonstrate scientific capacity and impact. In this context, this work aims to provide an overview of champion works (papers that have received over 1,000 citations) produced by Middle East countries. This analysis focuses on science, medicine, and technology papers featured in the Science Citation Index Expanded of Web of Science. The authors identified 213 champion works authored by Middle East scientists published since the 1970s. Israel is currently the leading nation in the Middle East in terms of published champion works, but at least one such work was identified for the majority of countries in the region. Middle East champion works were published on a diverse range of subject categories and often featured in the top journals worldwide (e.g., Science, Nature, etc.). The top institutions in the Middle East authoring champion works and their leading collaborating countries worldwide are listed, and the role of international scientific collaborations in achieving these highly cited papers is highlighted.     

A Longitudinal Study of Physics Students' Conceptions on Energy in Pre-Service Training for High School Teachers

Journal of Science Education and Technology - How physics students teachers' understanding of energy develops during their pre-service high school teacher university program? How do their...     

Antecedents and consequents of student satisfaction in higher technical-vocational education: evidence from Brazil

International Journal for Educational and Vocational Guidance - This article proposes a model of antecedents and consequences of student satisfaction in Higher Technical-Vocational Education (HTVE)...     

Beyond Rock and Roll: The Economic Impact of the Grateful Dead on a Local Economy

For-profit popular music concerts, a seldom studied event, may create sizeable economic impacts in a local economy. Using information from a survey of more than 1,000 concert goers to a Grateful Dead performance in Las Vegas and RIMS II multipliers, we estimate income and employment impacts. We conclude that the potential large spill-overs effects of such an event should not be ignored. This revised version was published online in August 2006 with corrections to the Cover Date.     

Childhood trauma and suicide risk in a sample of young individuals aged 14–35 years in southern Brazil

Suicide is among the main causes of death of people aged between 15 and 44 years old. Childhood trauma is an important risk factor for suicide. Hence, the objective of this study was to verify the relationship between childhood trauma and current suicide risk (suicidal behavior and ideation) in individuals aged 14–35 years, in the city of Pelotas, Brazil. This is a cross-sectional, population-based study. Sample selection was performed by clusters. Suicide risk was evaluated using the Mini International Neuropsychiatric Interview (MINI) and Childhood trauma was assessed with the Childhood Trauma Questionnaire (CTQ). Moreover, the participants responded to a questionnaire concerning socioeconomic status, work, and substance use. The sample was composed of 1,380 individuals. The prevalence of suicide risk was 11.5%. The prevalence figures of childhood trauma were 15.2% (emotional neglect), 13.5% (physical neglect), 7.6% (sexual abuse), 10.1% (physical abuse), and 13.8% (emotional abuse). Suicide risk was associated (p < .001) with gender, work, alcohol abuse, tobacco use, and all types of childhood trauma. The odds of suicide risk were higher in women (OR = 1.8), people who were not currently working (OR = 2.3), individuals who presented alcohol abuse (OR = 2.6), and among tobacco smokers (OR = 3.4). Moreover, suicide risk was increased in all types of trauma: emotional neglect (OR = 3.7), physical neglect (OR = 2.8), sexual abuse (OR = 3.4), physical abuse (OR = 3.1), and emotional abuse (OR = 6.6). Thus, preventing early trauma may reduce suicide risk in young individuals.     

What Do We Expect from Students' Physics Laboratory Experiments?

We want physics specialized high school and college students to think like physicists, and this involves an understanding of the scientific methods of inquiry and the ability to use these methods in their own investigations. In order to do that, students have to be made aware that no experimental result has any physical meaning unless an estimate of the uncertainty or precision is assigned to it. In this paper, we describe two simple experiments in which high school and college students measure physical constants, and make an easy analysis of their experimental data by applying the tools offered by microcomputers.