Long-term comparison (1921–2001) of numerical knowledge in three to five-and-a-half year-old children

This study contributes to the debate about the Flynn effect by proposing a long-term comparison (1921–2001) of the numerical knowledge of two cohorts of three- to five-and-a-half year-old children. In 1921, Beckmann (1923) assessed the numerical development of children using four tasks (Production, Distinction, Recognition, and Naming). In 2001, we used these same tasks to test 400 children equally divided into five age groups spaced six months apart. The main results are as follows: (1) the order of difficulty of the four tasks was the same in 2001 and 1921; (2) the 2001 cohort significantly outperformed the 1921 cohort with an advance in numerical development ranging from six months to one year, depending on the task; (3) the superiority of the 2001 children showed up by the age of 3; (4) the magnitude of the rise in scores varied across tasks (the greatest gain was found for the Naming task); and (5) the children in the two cohorts used the same number-evaluation strategies, but the 2001 children used more mature strategies on the Naming task than did same-age 1921 children, particularly subitizing for apprehending small numbers. The rise in scores seems to correspond to a genuine gain in numerical ability, apparently promoted by parental child-raising practices (cross-generational transmission).     

Vanilla teaching as a rational choice: the impact of research and compliance on teacher development

This paper examines the proposition that the quality of university teaching in the research-intensive university is affected by various compliance demands on academic work that are meant to either enhance or be complementary to teaching. These include holding academics to account for the quality of both research and teaching. Our research aims to contribute to evolving theories about the research-teaching nexus and the relationship between compliance and teaching quality. Twenty five in-depth interviews were undertaken with lecturers at a research-intensive university. It was found that research was valued more than teaching, and teaching quality only needed to be good enough to achieve career goals. Once a certain compliance level had been reached in teaching, lecturers could justify apportioning more time for research. We have described teaching in this context as ‘vanilla’ and argue that vanilla teaching is a rationale choice for university academics.     

Yo-Yo Intermittent Endurance Test-Level 1 to monitor changes in aerobic fitness in pre-pubertal boys

The present study aimed to examine the performance and heart rate responses during the Yo-Yo Intermittent Endurance Test-Level 1 (Yo-Yo IE1) in children under the age of 10. One hundred and seven male children (7–9 years) performed the Yo-Yo IE1 at the beginning (M₁), middle (M₂) and end (M₃) of the school year. Data from individual heart rate curves of the Yo-Yo IE1 were analysed in order to detect the inflection point between an initial phase of fast rise in heart rate values and a second phase in which the rise of the heart rate values is much smaller. The distance covered in the Yo-Yo IE1 improved from M₁ to M₃ (884 ± 496 vs. 1032 ± 596 m; p < 0.05; d = 0.27), with intermediate values for M₂ (962 ± 528 m). Peak heart rate (HR_peak) decreased from M₁ to M₂ and M₃ (204 ± 9, 202 ± 9 and 200 ± 9 bpm, respectively; p < 0.05; d = 0.25–0.42). The 7th shuttle of the test (280 m), corresponding to 2.5 min, was identified as the inflection point between the two phases. Also, absolute heart rate at the 7th shuttle decreased progressively throughout the year (185 ± 9, 183 ± 10, and 179 ± 10 bpm; p < 0.05; d = 0.31–0.61). The present study provides evidence of the usefulness of a maximal as well as a submaximal version of Yo-Yo IE1 as a tool to monitor changes in aerobic fitness in pre-pubertal children.     

Acute effects of exercise and active video games on adults’ reaction time and perceived exertion

The purpose of the present study was to examine the acute effects of resting, aerobic exercise practised alone, and aerobic exercise with active video games (AVG), on complex reaction time (CRT) and the post-exercise acute rate of perceived exertion (RPE) in young healthy adults. The experimental group was composed of 92 healthy young adults, 78 males and 13 females (age M?=?21.9?±?2.7 years) who completed two sessions, A and B. In session A, participants rode 30?min on an ergometer, while in session B they exercised for 30?min on an ergometer while playing an AVG on a Wii. The control group was composed of 30 young adults, 26 males and 4 females (age M?=?21.4?±?2.9 years) who rested for 30?min. In each session, a CRT task was performed before and after exercising or resting, and post-exercise global RPE was noted. Repeated measures general linear model (GLM) and Wilcoxon tests were performed. (1) Both aerobic exercise alone and aerobic exercise combined with AVG improved CRT, while resting did not; (2) aerobic exercise combined with AVG did not improve CRT more than aerobic exercise only; and (3) RPE was lower after aerobic exercise combined with AVG compared with aerobic exercise only. In young adults, exercise produces acute benefits on CRT, and practising exercise with AVG helps to decrease RPE.     

Relationship between physical activity,physical fitness and multiple metabolic risk in youths from Muzambinho's study

Negative associations between physical activity (PA), physical fitness and multiple metabolic risk factors (MMRF) in youths from populations with low PA are reported. The persistence of this association in moderately-to highly active populations is not, however, well established. The aim of the present study was to investigate this association in a Brazilian city with high frequency of active youths. We assessed 122 subjects (9.9?±?1.3 years) from Muzambinho city. Body mass index, waist circumference, glycaemia, cholesterolaemia, systolic and diastolic blood pressures were measured. Maximal handgrip strength and one-mile walk/run test were used. Leisure time PA was assessed by interview. Poisson regression was used in the analysis. The model explained 11% of the total variance. Only relative muscular strength and one-mile walk/run were statistically significant (p?相似文献   

Multiobjective optimization and multivariable control of the beer fermentation process with the use of evolutionary algorithms

This paper describes empirical research on the model, optimization and supervisory control of beer fermentation. Conditions in the laboratory were made as similar as possible to brewery industry conditions. Since mathematical models that consider realistic industrial conditions were not available, a new mathematical model design involving industrial conditions was first developed. Batch fermentations are multiobjective dynamic processes that must be guided along optimal paths to obtain good results. The paper describes a direct way to apply a Pareto set approach with multiobjective evolutionary algorithms (MOEAs). Successful finding of optimal ways to drive these processes were reported. Once obtained, the mathematical fermentation model was used to optimize the fermentation process by using an intelligent control based on certain rules.     

Analysis of the intraseasonal stability of field test performances in young academy soccer players

This study aimed to observe the intraseasonal stability of anthropometric, technical and functional test results in academy soccer players of different age categories. In total, 103 participants (age range: 7.7–13.4 years) by 5 age categories of the same academy were recruited for this study. Players were submitted to a field-test battery comprising 3 anthropometric measurements (body mass, stature and body mass index), 6 soccer technical tests (to assess the ability of ball control, ball control with the head, pass accuracy, shooting accuracy, dribbling and dribbling with pass) and 3 functional tests (countermovement jump with the hands on the hip, countermovement jump with free hands and 15-m linear sprint) that was administered in 4 test sessions during the same season. Though anthropometric results showed a clear increment in each age category across the season, the fluctuation of technical test results depended on age category and test session. Moreover, a significant increase in the results of functional tests was observed in most of the age categories, in particular, for the assessment of lower power limb. In conclusion, collecting repeated intraseason measurements permits the identification of players’ fluctuations of performance across the season and allows coaches to make frequent adjustments of their programmes.     

Effects of 6-month soccer and traditional physical activity programmes on body composition,cardiometabolic risk factors,inflammatory, oxidative stress markers and cardiorespiratory fitness in obese boys

Physical activity is important in obesity prevention, but the effectiveness of different physical activity modalities remains to be determined among children. The main purpose of this study was to compare the effects of a 6-month soccer programme and a traditional physical activity programme on changes in body composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status in obese boys. Eighty-eight boys (8–12 years; BMI > +2 standard deviations of WHO reference values) participated in one of three groups: soccer, traditional activity and control. Soccer and traditional activity programmes involved 3 sessions per week for 60–90 min at an average intensity of 70–80% of maximal heart rate. Control group participated in activities of normal daily living. All boys participated in school physical education, two sessions per week of 45–90-min. Measurements were taken at baseline and after 6 months, and included body size and composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status. Physical activity and dietary intake were assessed before and immediately following the intervention. The three groups had similar characteristics at baseline. After 6 months, both intervention groups had significantly lower relative fatness (% fat), waist circumference and total cholesterol, and higher cardiorespiratory fitness, self-esteem, perceived physical competence and attraction to physical activity compared with control group. In conclusion, physical activity interventions over 6 months positively influenced several indicators of health status among obese boys. The results also suggested that soccer has the potential as an effective tool for the prevention and reduction of childhood obesity and associated consequences.     

The peak velocity derived from the Carminatti Test is related to physical match performance in young soccer players

ABSTRACT

The aim of this study was to examine the relationship between the peak velocity derived from the Carminatti Test (T-CAR) (PV_T-CAR) and physical match performance in young soccer players. Thirty-three youth soccer players were recruited from 2 non-professional clubs. Friendly matches and small-sided game were performed. Physical match demands were assessed using Global Positioning System (GPS) technology. On a separate occasion, the players were submitted to the T-CAR. Players were categorised into 3 groups based on their T-CAR performance: Low (PV_T-CAR ≤ P33), Intermediate (P33 > PV_T-CAR < P66) and High (PV_T-CAR ≥ P66). The PV_T-CAR (15.5 ± 0.7 km·h^?1) was significantly related to high-intensity activities (HIA; r = 0.78, P < 0.001), high-intensity running (HIR; r = 0.66, P < 0.001), sprinting (r = 0.62, P < 0.001) and total distance (TD) covered (r = 0.47, P < 0.01) during friendly matches. The PV_T-CAR was strongly correlated with the amount of HIA (r = 0.81, P < 0.001), HIR (r = 0.85, P < 0.001) and TD covered (r = 0.81, P < 0.001) during small-sided game. No significant correlation was observed between the PV_T-CAR and distance of sprinting (r = 0.49, P = 0.067) during small-side game. Furthermore, players in the High group covered significantly more TD (10%) and did more HIA (42%), sprinting (31%) and HIR (25%) during friendly matches compared to the players classified as having Low performance on the T-CAR. These differences still remained after adjusting for chronological age (CA), maturity and body size. In conclusion, the current study gives empirical support to the ecological and construct validity of this novel field test (T-CAR) as an indicator of match-related physical performance in young soccer players during pubertal years.     

Validity of an Athletic Skills Track among 6- to 12-year-old children

The purpose of this study was to examine the feasibility and validity of an Athletic Skills Track (AST) to assess fundamental movement skills among 6- to 12-year-old children in a physical education setting. Four hundred sixty-three Dutch children (211 girls, 252 boys) completed three tests: the Körperkoordinationstest für Kinder (KTK) and two Athletic Skills Tracks (AST-1, AST-2). The validity of AST-1 and AST-2 was examined by correlating the time (s) needed to complete the tracks and the KTK Motor Quotient (MQ).

Overall, there was a low correlation between AST-1 and the KTK MQ (r = –0.474 (P < 0.01)) and a moderate correlation between AST-2 and the KTK MQ (r = –0.502 (P < 0.01)). When split up by age group the associations were much higher and ranged between r = –0.469 and r = –0.767), with the exception of the low correlation coefficient of the AST-2 in 7-year-olds. The results indicate that fundamental movement skills of 6- to 12-year-old children can be assessed with a quick, convenient and low-cost motor competence test in a physical education setting, i.e., an Athletic Skills Track. Future studies should further assess the reliability, discriminative ability and validity of age-specific versions of the AST.