Predicting centre of mass horizontal speed in low to severe swimming intensities with linear and non-linear models

We aimed to compare multilayer perceptron (MLP) neural networks, radial basis function neural networks (RBF) and linear models (LM) accuracy to predict the centre of mass (CM) horizontal speed at low-moderate, heavy and severe swimming intensities using physiological and biomechanical dataset. Ten trained male swimmers completed a 7 × 200 m front crawl protocol (0.05 m.s^?1 increments and 30 s intervals) to assess expiratory gases and blood lactate concentrations. Two surface and four underwater cameras recorded independent images subsequently processed focusing a three-dimensional reconstruction of two upper limb cycles at 25 and 175 m laps. Eight physiological and 13 biomechanical variables were inputted to predict CM horizontal speed. MLP, RBF and LM were implemented with the Levenberg-Marquardt algorithm (feed forward with a six-neuron hidden layer), orthogonal least squares algorithm and decomposition of matrices. MLP revealed higher prediction error than LM at low-moderate intensity (2.43 ± 1.44 and 1.67 ± 0.60%), MLP and RBF depicted lower mean absolute percentage errors than LM at heavy intensity (2.45 ± 1.61, 1.82 ± 0.92 and 3.72 ± 1.67%) and RBF neural networks registered lower errors than MLP and LM at severe intensity (2.78 ± 0.96, 3.89 ± 1.78 and 4.47 ± 2.36%). Artificial neural networks are suitable for speed model-fit at heavy and severe swimming intensities when considering physiological and biomechanical background.     

Cross‐time attitudes,concept formation,and achievement in college freshman physics

The relationships among science and engineering attitude, physics conceptual understanding, and physics achievement were explored for a population of college freshman engineering students over two semesters. Gender and SAT‐Quantitative measures were included as exogenous variables in a longitudinal path analysis. Attitude was theorized to predict achievement contemporaneously and at the next time point, while conceptual understanding was theorized to predict physics achievement contemporaneously and at the next time point. Each at one time was theorized to predict scores at the next time. A sample of 200 freshman engineering students participating in an integrated curriculum were assessed in September, December, and April (with a loss of 64 students) with the Force Concepts Inventory (FCI), Mechanics Baseline Test (MBT), and a locally developed attitude measure. The observed model indicated that the FCI predicted attitude at time 1 with no other paths between them, that FCI at time 1 predicted MBT at time 1 and time 2, FCI at time 2 predicted MBT at time 3, and MBT at time 1 predicted FCI at time 2. Gender and SAT‐Quantitative scores were predictive only of FCI and MBT at time 1. Results supported an interactive model of conceptual understanding and achievement, with attitude largely irrelevant to the process for this population. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 1112–1120, 2000     

The ingestion of a caffeinated energy drink improves jump performance and activity patterns in elite badminton players

The aim of this study was to investigate the effectiveness of a caffeine-containing energy drink to enhance physical and match performance in elite badminton players. Sixteen male and elite badminton players (25.4 ± 7.3 year; 71.8 ± 7.9 kg) participated in a double-blind, placebo-controlled and randomised experiment. On two different sessions, badminton players ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo). After 60 min, participants performed the following tests: handgrip maximal force production, smash jump without and with shuttlecock, squat jump, countermovement jump and the agility T-test. Later, a 45-min simulated badminton match was played. Players’ number of impacts and heart rate was measured during the match. The ingestion of the caffeinated energy drink increased squat jump height (34.5 ± 4.7 vs. 36.4 ± 4.3 cm; P < 0.05), squat jump peak power (P < 0.05), countermovement jump height (37.7 ± 4.5 vs. 39.5 ± 5.1 cm; P < 0.05) and countermovement jump peak power (P < 0.05). In addition, an increased number of total impacts was found during the badminton match (7395 ± 1594 vs. 7707 ± 2033 impacts; P < 0.05). In conclusion, the results show that the use of caffeine-containing energy drink may be an effective nutritional aid to increase jump performance and activity patterns during game in elite badminton players.     

Analysis of the distance covered by Brazilian professional futsal players during official matches

The purpose of this study was to measure and characterise the distances covered by Brazilian professional futsal players. The trajectories of 93 players during five matches were obtained using an automatic tracking method. The distances covered were analysed for different game conditions: over the entire game and during the times when the ball was out of play and in play separately. When the entire game was considered, the results showed that there was a reduction in the total distance covered per minute from the first [median ± IQR (interquartile range): 97.9 ± 16.2 m/min] to the second half (median = 90.3 m/min; IQR = 12.0), and when only the in-play time was considered (first half: 136.6 ± 17.2 m/min; second half: 129.2 ± 16.7 m/min). The percentage of distance covered in the standing and walking velocity range was higher in the second half than in the first when considering the entire game (30.8% and 28.0%, respectively) and during the in-play time (19.3% and 16.2%, respectively). In conclusion, this study verified that futsal players reduced the physical performance during the second half.     

Disciplinary epistemologies,generic attributes and undergraduate academic writing in nursing and midwifery

Generic attributes such as ‘holding a critical stance’, ‘using evidence to support claims’, and ‘projecting an impersonal voice’ are central to disciplinary academic writing in higher education. These attributes, also referred to as ‘skills’, have for a long time been conceptualised as transferable in that once learnt students are able to use them in a variety of contexts and for a range of needs. Over the past few years, however, the conceptualisation of these attributes as transferable has come under close scrutiny as they have been identified to be highly context-sensitive rather than context-flexible as they were once thought to be. Drawing on data from a 2-year study on undergraduate academic writing in nursing and midwifery at a university in the UK, this paper critically examines the role of disciplinary epistemologies in the conceptualisation of these attributes in the two disciplines, and demonstrates how these beliefs help to shape academic writing at undergraduate level, thus contributing to debates on generic skills and attributes and specificity in disciplinary discourses. The paper concludes by highlighting the importance for writers to examine how knowledge is displayed, constructed and communicated in their disciplines, and the significance of analysing the relationship between disciplinary epistemologies, generic attributes and academic writing as a way of gaining access to and producing central discourses in their professional community.     

ICT teacher training: a view of the TPACK model / Formación del profesorado en TIC: una visión del modelo TPACK

This paper presents a study on the TPACK model (Technological Pedagogical Content Knowledge), which focuses on the assumption that in order to use ICTs effectively in teaching, the instructor must be trained in technological, content and pedagogical knowledge. In consequence, education, teacher training and professional development programmes should provide learning opportunities so that teachers can develop and put into action the three areas included in the model. To analyse the TPACK model of the teachers included in the study, a translation of an already developed instrument was applied; its reliability resulted in a Cronbach’s alpha of .97. The sample was comprised of 1,368 people who conducted training activities related to education and technologies at universities in Spain, Argentina, Colombia, the Dominican Republic and Venezuela. The results reveal the need to stress not the technological aspects but the pedagogical and content knowledge, which is where the respondents earned the lowest scores.     

Physical characteristics that predict involvement with the ball in recreational youth soccer

This study examined the relative contribution of age, stage of puberty, anthropometric characteristics, health-related fitness, soccer-specific tests and match-related technical performance to variance in involvements with the ball during recreational 5-a-side small-sided (32 × 15 m) soccer matches. Using a cross-sectional design, 80 healthy male students (14.6 ± 0.5 years of age; range 13.6–15.4) who played soccer recreationally were randomly divided into 10 teams and played against each other. Measurements included height, body mass, pubertal status, health-related fitness (12-min walk/run test, standing long jump, 15-m sprint and sit-ups in 30 s), soccer-specific tests (kicking for speed, passing for accuracy and agility run with and without a ball), match-related technical performance (kicks, passes and dribbles) and involvements with the ball during matches. Forward multiple regression analysis revealed that cardiorespiratory fitness (12-min walk/run test) accounted for 36% of the variance in involvements with the ball. When agility with the ball (zigzag running) and power (standing long jump) were included among the predictors, the total explained variance increased to 62%. In conclusion, recreational adolescent players, regardless of their soccer-specific skills, may increase participation in soccer matches most through physical activities that promote improvement in cardiorespiratory fitness, muscle power and agility.     

The recent process of decentralization and democratic management of education in Brazil

Brazilian society is beginning a new historical period in which the principle of decentralization is beginning to predominate over centralization, which held sway during the last 25 years. In contrast to recent Brazilian history, there is now a search for political, democratic and participatory decentralization more consonant with grass-roots aspirations. The first section of this article presents a brief analysis of some decentralization policies implemented by the military regime of 1964, and discusses relevant facts related to the resistance of civil society to state authoritarianism, and to the struggle for the democratization and organization of civil society up to the end of the 1970s. The second section analyzes some new experiences of democratic public school administration initiated in the 1970s and 1980s. The final section discusses the move toward decentralization and democratization of public school administration in the new Federal and State Constitutions, and in the draft of the new Law of National Education.

---

Zusammenfassung Die brasilianische Gesellschaft beginnt einen neuen Abschnitt in ihrer Geschichte, in dem das Prinzip der Dezentralisierung über die in den letzten 25 Jahren vorherrschende Zentralisierung dominiert. Im Gegensatz zur jüngsten brasilianischen Geschichte wird nunmehr eine politische, demokratische und partizipatorische Dezentralisierung gesucht, die mit den regionalen Bestrebungen besser vereinbar ist. Der erste Teil dieses Artikels enthält eine kurze Analyse einiger 1964 vom Militärregime eingeführter Dezentralisierungmaßnahmen und untersucht relevante Fakten, die mit dem Widerstand der zivilen Gesellschaft gegen die Staatsgewalt und mit dem Kampf um Demokratisierung und eine Organisation der zivilen Gesellschaft bis Ende der 70er Jahre zusammenhängen. Im zweiten Teil werden einige neue Erfahrungen den in der 70er und 80er Jahren eingeführten Verwaltung öffentlicher demokratischer Schulen analysiert. Im Schlußteil geht es um die Entwicklung zur Dezentralisierung und Demokratisierung der öffentlichen Schulverwaltung in den neuen Bundes- und Staatsverfassungen und im Entwurf des neuen Gesetzes zu Nationaler Bildung.

---

Résumé La société brésilienne entame une nouvelle ère historique caractérisée par une prédominance du principe de décentralisation sur celui de centralisation, qui a prévalu durant les 25 dernières années. Par comparaison à l'histoire brésilienne moderne, on vise actuellement une décentralisation politique, démocratique et fondée sur la participation, qui soit plus en harmonie avec les aspirations du peuple. La première partie du présent article contient une brève analyse des politiques de décentralisation appliquées par le régime militaire de 1964, et discute les faits pertinents relatifs à la résistance de la société civile à l'autoritarisme de l'Etat, et à la lutte pour la démocratisation et l'organisation de la société civile jusqu'à la fin des années 70. La deuxième partie analyse quelques expériences récentes concernant la démocratisation de l'administration de l'école publique, inaugurée dans les années 70 et 80. La dernière partie examine le passage à la décentralisation et à la démocratisation dans l'administration de l'école publique dans la nouvelle constitution fédérale et dans celles des Etats fédérés, ainsi que dans le nouveau projet de loi sur l'Education nationale.

     

Elementary students’ metacognitive processes and post-performance calibration on mathematical problem-solving tasks

Calibration, or the correspondence between perceived performance and actual performance, is linked to students’ metacognitive and self-regulatory skills. Making students more aware of the quality of their performance is important in elementary school settings, and more so when math problems are involved. However, many students seem to be poorly calibrated, with a tendency towards over-confidence. The present study analyzes the relationship between post-performance calibration accuracy and the metacognitive process shown by 524 fifth- and sixth-grade students while solving two math problems. After calculating a calibration index and establishing the stability of students’ judgments and actual performance, differences in the metacognitive process exhibited by students with different calibration accuracy (Accurate vs. Inaccurate groups) were analyzed. The emergence of different calibration patterns and differences in the metacognitive process as a function of mathematics achievement and grade level were also examined. Results indicated that: (a) students in the overall sample were little calibrated and over-confident, showing high stability in their judgments and actual performance across problems; (b) inaccurate students reported using information representation sub-processes (drawing/summarizing) less frequently, but writing and reviewing (and also correcting mistakes) more frequently than their accurate peers; and (c) differences in calibration patterns and the metacognitive process were found when achievement level was considered, whereas grade level did not generate any important effect. These findings suggest the usefulness of process-based measures to examine the metacognitive processes involved in making post-performance judgments, considering achievement and its possible mediating role in this relationship.     

Cognitive,Motivational, and Volitional Dimensions of Learning: An Empirical Test of a Hypothetical Model

The principal aim of this research is to contrast empirically a hypothetical model developed on the basis of the fundamental assumptions of current self-regulated learning models. In line with evaluation criteria of model fit, a high rate of congruence between the hypothesized theoretical model and the empirical data was observed. Analysis of the effects between the variables of the model revealed the following relevant aspects: students' predisposition to feel responsible for the results of their academic behavior (internal attribution) is related to positive self-image (academic self-concept), both being important conditions for development of learning-oriented motivation (learning goals). All of this involves selection and use of learning strategies for deep information processing (deep learning strategies), which leads students to assume responsibility with high levels of persistence, perseverance, and tenacity so as to achieve goals defined by the motivational orientation. This persistence and effort to achieve the proposed goals has in turn a positive and significant effect on academic achievement.