The acute effects of static stretching on peak force,peak rate of force development and muscle activity during single- and multiple-joint actions in older women

Abstract

The present study investigated the acute effects of static stretching on peak force, peak rate of force development and integrated electromyography (iEMG) in 27 older women (65 ± 4 years; 69 ± 9 kg; 157 ± 1 cm; 28 ± 4 kg · m^?2). The participants were tested during two exercises (leg press and knee extension) after two conditions: stretching and control. The data were collected on four days (counterbalanced with a 24-hour rest period). In the stretching condition, the quadriceps muscle was stretched (knee flexion) for three sets of 30 s with 30 s rest intervals. No significant difference was detected for peak force and peak rate of force development during the single- and multiple-joint exercises, regardless of the following interactions: condition (stretching and control) vs. time (pre x post x 10 x 20 x 30 minutes post; P > 0.05) and exercise vs. time (P > 0.05). Additionally, no significant interaction was found for the iEMG activity (condition vs. time; P > 0.05) in the single- and multiple-joint exercises. In conclusion, a small amount of stretching of an agonist muscle (quadriceps) did not affect the peak force, peak rate of force development and EMG activity in older women during single- and multiple-joint exercises.     

PART III: KINANTHROPOMETRY

Whole-body bone mineral density and bone mineral mass in young adult rugby union players.     

Faculty-exchange programs promoting change: motivations,experiences, and influence of participants in the Carnegie Mellon University-Portugal Faculty Exchange Program

The international mobility of faculty is increasing worldwide. Although studies have considered the experiences of academics abroad, less is known about faculty-exchange programs with policy objectives. This study helps to fill this gap by analyzing a nationwide structured faculty exchange program established by Carnegie Mellon University and Portuguese universities to bring change to Portuguese higher education. The findings are based on interviews with Portuguese program participants, whose motivation to participate and experiences with the program, in addition to the influence of their experience abroad on their home institution, were explored. We find that, although the alignment of individual motivations with institutional interests is important to such programs, the complex transposition of individual experiences to the institutional level may be impeded by cultural resistance as well as resource and organizational constraints. Our exploration of the features that determine the success or failure of these experiences provides insights for policymakers seeking to implement faculty-mobility programs in the future.     

Developing mathematical understanding and students with emotional and behavioural disorders: a review of the literature

Recent shifts in focus on academic interventions for students diagnosed with emotional and behavioural disorders (EBD) create a need to evaluate existing interventional research in content areas such as mathematics. Literature reviews in the area of mathematics interventions for students with EBD have mostly focused on the outcomes and the rigour of existing studies with limited attention to the quality of the pedagogical methods used in those studies. The purpose of this conceptual review was to use a teaching-for-understanding lens to examine existing research interventions in mathematics for students with EBD. Teaching-mathematics-for-understanding requires pedagogical methods that aim to activate and capture students’ mathematical reasoning and thinking. An iterative electronic and hand search of the literature found 30 studies covering three decades (1985–2015) that met the criteria for inclusion in this review. Results of the analysis include: (1) mathematics assessments utilised ranged from very basic to comprehensive, with most studies applying basic assessments; (2) a majority of the studies focused on intervention strategies targeting procedural and rote knowledge; (3) most studies utilised quantitative inquiry methods; and (4) in more recent years, studies have increasingly examined conceptual mathematical understanding and incorporated qualitative inquiry methods.     

Scoring mode and age-related effects on youth soccer teams’ defensive performance during small-sided games

ABSTRACT

This study aimed to examine the scoring mode (line goal, double goal or central goal) and age-related effects on the defensive performance of youth soccer players during 4v4 small-sided games (SSGs). Altogether, 16 male players from 2 age groups (U13, n = 8, mean age: 12.61 ± 0.65 years; U15, n = 8, 14.86 ± 0.47 years) were selected as participants. In six independent sessions, participants performed the three SSGs each during 10-min periods. Teams’ defensive performance was analysed at every instant ball possession was regained through the variables: ball-recovery type, ball-recovery sector, configuration of play and defence state. Multinomial logistic regression analysis used in this study revealed the following significant main effects of scoring mode and age: (1) line goal (vs. central goal) increased the odds of regaining possession through tackle and in the defensive midfield sector, and decreased the odds of successful interceptions; (2) double goal (vs. central goal) decreased the odds of regaining possession through turnover won and with elongated playing shapes; (3) the probability of regaining possession through interception significantly decreased with age. Moreover, as youth players move forward in age groups, teams tend to structurally evolve from elongated playing shapes to flattened shapes and, at a behavioural level, from defending in depth to more risky flattened configurations. Overall, by manipulating the scoring mode in SSGs, coaches can promote functional and coadaptive behaviours between teams not only in terms of configurations of play, but also on the pitch locations that teams explore to regain possession.     

Breaking the habit: engineering students’ understanding of mathematical creativity

ABSTRACT

In higher education, engineering students have to be prepared for their future jobs, with knowledge but also with several soft skills, among them creativity. In this paper, we present a study carried on with 128 engineering undergraduate students on their understanding of mathematical creativity. The students were in the first year of different engineering first degrees in a north-eastern Portuguese university and we analysed the content of their texts for the question ‘What do you understand by mathematical creativity?’. Data collection was done in the first semester of the academic years 2014/2015 and 2016/2017 in a Linear Algebra course. The results showed that ‘problem solving’ category had the majority of the references in 2014/2015, but not in the academic year 2016/2017 were ‘involving mathematics’ category had the majority. This exploratory study pointed out for ‘problem solving’ and ‘involving mathematics’ categories and gave us hints for teaching mathematics courses in engineering degrees.     

Executive Functioning and School Readiness Among Preschoolers With Externalizing Problems: The Moderating Role of the Student–Teacher Relationship

Research Findings: The objective of this study was to examine the student–teacher relationship as a potential moderator of the link between executive functioning (EF) and children’s early school readiness among a clinical sample of preschoolers with externalizing behavior problems (EBP). Participants for the study included 139 preschool children (75.54% boys, M age = 5.01 years, 84.94% Hispanic/Latino) with at-risk or clinically elevated levels of EBP. The student–teacher relationship was assessed using the Student–Teacher Relationship Scale. School readiness data were composed of standardized achievement test scores and teacher reports of kindergarten readiness. EF was measured via parent and teacher reports along with standardized measures of EF, including the Head–Toes–Knees–Shoulders task and 4 standardized subtests from the Automated Working Memory Assessment. Poorer student–teacher relationship quality was predictive of lower teacher-reported kindergarten readiness and higher academic impairment. Main effects were qualified by an interaction between EF and student–teacher relationship quality such that worse EF (parent/teacher reports and standardized performance) was only associated with lower teacher-rated kindergarten readiness for children with poorer student–teacher relationship quality. Practice or Policy: EF appears to be an important predictor of school readiness for preschool children with EBP, particularly for children experiencing poorer student–teacher relationships.     

Testing the scalar expectancy theory (SET) and the learning-to-time model (LeT) in a double bisection task

Two theories of timing, scalar expectancy theory (SET) and learning-to-time (LeT), make substantially different assumptions about what animals learn in temporal tasks. In a test of these assumptions, pigeons learned two temporal discriminations. On Type 1 trials, they learned to choose a red key after a 1-sec signal and a green key after a 4-sec signal; on Type 2 trials, they learned to choose a blue key after a 4-sec signal and a yellow key after either an 8-sec signal (Group 8) or a 16-sec signal (Group 16). Then, the birds were exposed to signals 1 sec, 4 sec, and 16 sec in length and given a choice between novel key combinations (red or green vs. blue or yellow). The choice between the green key and the blue key was of particular significance because both keys were associated with the same 4-sec signal. Whereas SET predicted no effect of the test signal duration on choice, LeT predicted that preference for green would increase monotonically with the length of the signal but would do so faster for Group 8 than for Group 16. The results were consistent with LeT, but not with SET.     

A Teaching-Learning Sequence of Colour Informed by History and Philosophy of Science

In this work, we present a teaching-learning sequence on colour intended to a pre-service elementary teacher programme informed by History and Philosophy of Science. Working in a socio-constructivist framework, we made an excursion on the history of colour. Our excursion through history of colour, as well as the reported misconception on colour helps us to inform the constructions of the teaching-learning sequence. We apply a questionnaire both before and after each of the two cycles of action-research in order to assess students’ knowledge evolution on colour and to evaluate our teaching-learning sequence. Finally, we present a discussion on the persistence of deep-rooted alternative conceptions.     

Introduction to the Treatment of Non-Linear Effects Using a Gravitational Pendulum

We show that the treatment of pendulum movement, other than the linear approximation,may be an instructive experimentally based introduction to the physics of non-lineareffects. Firstly the natural frequency of a gravitational pendulum is measured as functionof its amplitude. Secondly forced oscillations of a gravitational pendulum are investigatedexperimentally without limiting amplitudes. By this arrangement new phenomena, thebistability and the jump-effect, can be observed. In the case of bistability the drivengravitational pendulum can oscillate in two different stable modes. Either it oscillateswith a small amplitude and approximately in phase with the exciting torque or it oscillateswith a larger amplitude and approximately anti-phase. The jump effect is the spontaneoustransition from one mode of oscillation to the other. Both effects can be demonstrated andexplained.