Performance,motivation, and enjoyment in young female basketball players: An interdisciplinary approach

ABSTRACT

The purpose of this study was to examine the variation in accumulated basketball training experience, body size, functional performance, deliberate practice motivation, achievement and competitiveness motivation and sources of enjoyment among young female basketball players, partitioning the potential variation by individuals´ biological characteristics (menarche status) and contextual characteristics (competitive age group and competitive level). We considered 114 adolescent female basketball players aged 14.3 (1.8) years. We used multilevel regression and poststratification estimations. The adolescent female basketball players selected for state-level had more accumulated experience, were taller and with better functional performance. Conditional on the data, youth female coaches tend to value (probably overvalue) size and function when selecting/promoting players, even at early age groups, likely contributing to an overrepresentation of early maturing girls in at early age groups. Players from club- and state-level were similarly highly motivated for deliberate practice and to achievement. Only for competitiveness, state-level players had higher values than club level players. The sources of enjoyment were influenced by context (competitive levels) for self-referenced competencies and others-referenced competencies. Structured programs of training and competition in youth female basketball provide a nurturing environment for the development of players´ engagement and commitment to training and excellence attainment.     

Is it worth establishing institutional repositories? The strategies for open access to Spanish peer‐reviewed articles

We examine open access to the Spanish scientific literature via investigation of a sample of peer‐reviewed articles in seven subject categories. Of the 28,259 papers published in 2000, 26.89% were freely accessible, with the share varying among disciplines. Articles in the social and behavioral sciences were the most widely available for free. This disciplinary divide applies also to the strategies used to offer open access to documents. In clinical medicine, life sciences, arts and humanities and social sciences open access was mainly based on the publishers' side, while subject‐based repositories were dominant in physical, chemical and earth sciences and deposit on homepages was the preferred strategy in engineering, computing and technology. Institutional and general repositories seem to play a minor role in providing free access to the Spanish peer‐reviewed literature. Papers published in commercial journals are less accessible than those that appear in non‐commercial journals, and we found overlaps in almost 20% of papers deposited. The fastest way to gain open access is to deposit in subject‐based repositories and the longest delays are related to deposits in homepages and especially to institutional repositories. Open access to Spanish peer‐reviewed articles is dominated by the passive mechanism of the “gold route” and the editorial strategy with self‐archiving practices in the minority and directed mainly towards subject‐based repositories and homepage posting of the papers. The results of this study could serve as a reference point for further study on the evolution of open access in Spain.     

Effects of different intensities of resistance training with equated volume load on muscle strength and hypertrophy

The present study investigated the effects of different intensities of resistance training (RT) on elbow flexion and leg press one-repetition maximum (1RM) and muscle cross-sectional area (CSA). Thirty men volunteered to participate in an RT programme, performed twice a week for 12 weeks. The study employed a within-subject design, in which one leg and arm trained at 20% 1RM (G20) and the contralateral limb was randomly assigned to one of the three conditions: 40% (G40); 60% (G60), and 80% 1RM (G80). The G20 started RT session with three sets to failure. After G20 training, the number of sets was adjusted for the other contralateral limb conditions with volume-matched. CSA and 1RM were assessed at pre, post-6 weeks, and post-12 weeks. There was time effect for CSA for the vastus lateralis (VL) (8.9%, 20.5%, 20.4%, and 19.5%) and elbow flexors (EF) (11.4%, 25.3%, 25.1%, and 25%) in G20, G40, G60, and G80, respectively (p?>?.05). G80 showed higher CSA than G20 for VL (19.5% vs. 8.9%) and EF (25% vs. 11.4%) at post-12 weeks (p?p?相似文献   

Sex-differences in elite-performance track and field competition from 1983 to 2015

The purpose of this study was to assess the veracity of the Court of Arbitration for Sport’s assertion that sex-differences in athletic performance in elite-standard track and field competition is of the order of 10–12%. Exponential curves were fitted to the data of selected track and field events of the finals of all IAAF World Championships and Olympic Games from 1983 to 2016. For each curve, the coefficient of determination R² was calculated, in combination the corresponding 95% confidence intervals for the curve constants. Sex-differences were evaluated via differences in the fitted curves between men and women. Mean performances of winners, as well as overall performance means of all participants, were also analyzed. The calculated sex-difference was 8.2 ± 1.0% – 11.8 ± 2.1% for sprints, 10.3 ± 3.3% – 12.8 ± 4.0% for middle and long-distance events, 9.7 ± 2.9% – 13.1 ± 2.9% for relays and 14.2 ± 2.2% – 25.0 ± 4.4% for jumps. This study therefore confirms that the percentage difference accepted by the CAS is appropriate for elite-standard track and field events.     

Hyperandrogenic athletes: performance differences in elite-standard 200m and 800m finals

The purpose of this study was to examine whether the difference in elite-standard track and field performance between women athletes with and without hyperandrogenism reaches the 10–12% difference in performance between men and women, using only results from elite-standard track and field final competitions. Officially available data from two hyperandrogenic women (Caster Semenya and Dutee Chand) were compared with the characteristic performance of 200m and 800m elite-standard finals. The finishing times of Caster Semenya, before her ineligibility to compete in 2009 and after the suspension of the 2011 IAAF Hyperandrogenism Regulations were found to be respectively 1.24% and 1.49% faster than the predicted performance in 800m finals. When compared with the result of the second classified, the difference was respectively 0.65% and 2.08%. The analysis of the finishing times of Dutee Chand did not lead to any conclusions due to the lack of available data. The present study indicates that the percentage difference in performance between women with and women without hyperandrogenism does not reach the 3% difference requested by the Court of Arbitration for Sport for the reinstatement of the Hyperandrogenism Regulations, neither does it reach the 10% accepted range of difference in performance between men and women.     

From closed source to open source software: Analysis of the migration process to Open Office

This article seeks to analyse the migration trajectory from commercial off-the-shelf and closed source software to open source software in order to establish the critical success/resistance factors associated with the replacement of the extant Microsoft Office with Open Office software in a private Brazilian company. The bibliographical review of this work addresses adoption/resistance to information systems, which is the theoretical framework adopted to explain the data collected. The single case study method was then applied and data was collected via documentation analysis, interviews, questionnaires, and direct and participant observation. Data analysis was then conducted by means of content analysis and non-parametric statistics. Based on that, three types of user behaviour were identified with respect to the intention to use open source software, namely adopters, partial adopters, and non-adopters. Finally, the reasons for such behaviour were set forth and discussed in order to make the implications of the study clear.     

In-depth cross-coupling analysis in high-performance induction motor control

High-performance field oriented control (FOC) of induction motors (IMs) relies on the accurate control of their electrical dynamics. In particular, perfect decoupling control of the stator currents should be ideally achieved for a FOC scheme to be efficient. However, the decoupling effectiveness afforded by most stator currents controllers may be influenced not only by the parameters and the operating condition, but also by the specific controller structure and the adopted coordinate system. A measure to assess decoupling effectiveness is non-existent in the IM control literature. To bridge this gap, an in-depth analysis of the cross-coupling inherent characteristics of the electrical subsystem of IMs under different well-known control structures is presented in this paper. Specifically, four control strategies previously studied and experimentally validated in the literature are critically assessed in this work: (1) stationary frame proportional-integral (PI) control, (2) synchronous frame PI control, (3) synchronous frame PI control with decoupling networks, and (4) improved stationary frame diagonal control. The decoupling capabilities of controllers in stationary and synchronous coordinates are examined, with a detailed insight on the role of decoupling methods. The analysis is performed in the frequency domain under the framework of individual channel analysis and design (ICAD). By application of ICAD, the decoupling effectiveness of FOC schemes is clearly exposed and quantified, with an assessment of the effects of parametric uncertainty being carried out for completeness. The effect of the inverter dynamics over cross-coupling is also treated using digital simulations. The results are useful to determine the conditions in which each control strategy has either advantages or disadvantages. Additionally, it is possible to determine the effect of several operating parameters over the stator currents cross-coupling such as nominal flux and torque levels.