Modelling the dynamics of children’s gross motor coordination

ABSTRACT

This study modelled children’s gross motor coordination, investigated sex-differences and identified the effects of fixed and dynamic correlates on motor coordination development. A total of 344 Portuguese children (170 girls), from 6 age cohorts (5 to 9 years of age), were followed consecutively for three years (age range 5 to 11 years) using a mixed-longitudinal cohort design. Birth weight, hand dominance and socioeconomic status (SES) were identified. Gross motor coordination, body mass index, physical fitness (PF) and physical activity (PA) were assessed annually. A sequence of multilevel hierarchical linear models were developed. Model 1 found that age, age², sex, sex-by-age and sex-by-age² were significant predictors (p < 0.05) of gross motor coordination. Boys outperformed girls from 6 years of age onwards. Model 2 found a cohort effect (p < 0.05). Model 3 found that right handers were more coordinated (p < 0.05). When the confounders of body mass index, PF and PA were added to the model (Model 4) it was found that boys and girls had parallel trajectories in their gross motor coordination development. In conclusion children with increasing body mass index were less coordinated, while those who were stronger and more agile had steeper trajectories of gross motor coordination with age.     

Historical coastal urban landscapes digital documentation and temporal study with 2D/3D modeling functionality: The case of Thessaloniki,Greece

The study refers to the visual representation of the coastal front of the historical center of Thessaloniki in northern Greece and its changes that have occurred through the years. Most of the old town was destroyed by fire on August 18, 1917. A few years later, the French architect and archeologist Ernest Hébrard proposed the reconstruction of the city centre, but his plans were never fully implemented. Since then, a series of interventions changed the form of the old town and consequently the coastal cityscape. The research was initially based on the photogrammetric processing of archive aerial images (1938) of Thessaloniki's city centre. Besides the vertical images, high oblique aerial images dated back to 1932, proved to be a significant source of information. A rich archive of old photographic material, sketches, drawings and gravures of the coastal forehead of the city was also used. Ortho-images of the coastal front, derived from laser scanning (2010), and a 3D model of the historical city center, derived from the stereo photogrammetric process of aerial images (1990), contributed decisively at the multi temporal study of the city front. The main outcomes of the present documentation study are the 3D representation (at scale of 1:200, accuracy 5 cm) of temporal changes of a part of the coastal front of the historical center of Thessaloniki and the 2D representation (at scale 1:100, accuracy 1–2 cm) of these changes with respect to variations on skyline, lacunas, interventions in old buildings, etc.     

A domain-independent approach to finding related entities

We propose an approach to the retrieval of entities that have a specific relationship with the entity given in a query. Our research goal is to investigate whether related entity finding problem can be addressed by combining a measure of relatedness of candidate answer entities to the query, and likelihood that the candidate answer entity belongs to the target entity category specified in the query. An initial list of candidate entities, extracted from top ranked documents retrieved for the query, is refined using a number of statistical and linguistic methods. The proposed method extracts the category of the target entity from the query, identifies instances of this category as seed entities, and computes similarity between candidate and seed entities. The evaluation was conducted on the Related Entity Finding task of the Entity Track of TREC 2010, as well as the QA list questions from TREC 2005 and 2006. Evaluation results demonstrate that the proposed methods are effective in finding related entities.     

Student gender stereotypes: contrasting the perceived maleness and femaleness of mathematics and language

The purpose of this study was to evaluate the gender stereotypes endorsed by elementary and high school students regarding mathematics and language. We developed a questionnaire allowing students to rate mathematics and language as either male or female domains and administered it to a sample of 984 elementary and high school French‐speaking Canadian students (Grades 6, 8, and 10). Results showed that, with the exception of Grade 6 boys, students did not believe that mathematics was a male domain, or even conceived of mathematics as a predominantly female domain, suggesting that the traditional stereotype favouring boys in mathematics might have changed over the past few years. Moreover, language was clearly viewed as a female domain. Overall, our findings suggest that boys seem to be in need of encouragement in school, especially regarding language, where the advantage given to girls is particularly salient.     

A practical illustration of multidimensional diagnostic skills profiling: Comparing results from confirmatory factor analysis and diagnostic classification models

In recent years there has been an increasing international interest in fine-grained diagnostic inferences on multiple skills for formative purposes. A successful provision of such inferences that support meaningful instructional decision-making requires (a) careful diagnostic assessment design coupled with (b) empirical support for the structure of the assessment grounded in multidimensional scaling models. This paper investigates the degree to which multidimensional skills profiles of children can be reliably estimated with confirmatory factor analysis models, which result in continuous skill profiles, and diagnostic classification models, which result in discrete skill profiles. The data come from a newly developed diagnostic assessment of arithmetic skills in elementary school that was specifically designed to tap multiple skills at different levels of definitional grain size.     

Parental Behavior,Cognitive Appraisal,and Motivation in Young Athletes

Purpose: This study tested two hypotheses relating young athletes’ sports motivations to parental behaviors and cognitive appraisal: (1) young athletes’ motivation in sports is related to their parents’ behavior; and (2) this relationship is mediated by cognitive appraisal, even after controlling for competitive level and sports records. Method: This cross-sectional study included 673 young athletes and it measured the athletes’ perceptions of parental behaviors, cognitive appraisal, and sports motivation. Results: Structural equation modeling confirmed Hypothesis 1–the mother’s behaviors accounted for 15 to 16% of the variance in sports motivation, and the father’s behaviors accounted for 12 to 21% of the variance. The correlation patterns differed according to whether the athletes were evaluating the mother’s or father’s behaviors. Hypothesis 2 also was confirmed, for cognitive appraisal partially mediated the relationship between the perception of parental behaviors and sports motivation (34% of the variance was accounted for by the perception of the mother’s behavior; 30% by the father’s). The mediating model did not vary with competitive level or sports records. Conclusion: Parental behaviors and cognitive appraisal need to be taken into account to understand young athletes’ sports motivations.     

Discovery of carbon-based strongest and hardest amorphous material

Carbon is one of the most fascinating elements due to its structurally diverse allotropic forms stemming from its bonding varieties (sp, sp² and sp³). Exploring new forms of carbon has been the eternal theme of scientific research. Herein, we report on amorphous (AM) carbon materials with a high fraction of sp³ bonding recovered from compression of fullerene C₆₀ under high pressure and high temperature, previously unexplored. Analysis of photoluminescence and absorption spectra demonstrates that they are semiconducting with a bandgap range of 1.5–2.2 eV, comparable to that of widely used AM silicon. Comprehensive mechanical tests demonstrate that synthesized AM-III carbon is the hardest and strongest AM material known to date, and can scratch diamond crystal and approach its strength. The produced AM carbon materials combine outstanding mechanical and electronic properties, and may potentially be used in photovoltaic applications that require ultrahigh strength and wear resistance.     

Body composition and nutritional profile of male adolescent tennis players

In this cross-sectional study, we evaluated the body composition and dietary intake of 44 adolescent tennis players. After being divided into two groups (age 10-13 years and age 14-18), the players had their weight, height, and sexual maturation assessed. Dual-energy X-ray absorptiometry was used to assess body composition. Food intake was obtained from a non-consecutive 4-day food record. The data were analysed using the Virtual Nutri v.1.0 software and compared with the present recommendations for adolescent athletes or dietary reference intakes. Body mass index and body fat for tennis practice were adequate for 89% and 71% of the tennis players respectively, regardless of age group. A calorie deficit greater than 10% of energy expenditure was observed in 32% of the sample. Fifty percent of the athletes consumed carbohydrates in accordance with recommended values. Protein and lipid intakes were above recommended values, while fibre, calcium, potassium, magnesium, and folic acid intakes were below recommendation for 98%, 80%, 100%, 100%, and 98% of the tennis players respectively. The observed nutritional deficiencies represent an additional barrier for adolescents engaged in competitive sports to achieve an optimum nutrition to maintain growth, health, and performance.