Do field position and playing standard influence athlete performance in wheelchair basketball?

Improved understanding of mobility performance in wheelchair basketball is required to increase game performance. The aim of this study was to quantify the wheelchair-athlete activities of players in different field positions and of different playing standard during wheelchair basketball matches. From video analysis, absolute and relative duration and frequency of wheelchair movements and athlete control options were examined in 27 national standard and 29 international standard players during entire wheelchair basketball matches. Between-group factorial analysis of variances identified that national players drove more forward (42.6 ± 6.8 vs. 35.4 ± 3.7%; effect size Cohen’s d (ES) = 1.48) and started more often driving forward (33.9 ± 2.6 vs. 31.8 ± 2.8; ES = 0.77) during a match while the mean activity duration for a single driving forward activity was longer (4.3 ± 0.9 vs. 3.7 ± 0.6 s; ES = 0.75) than for international players. Furthermore, national players performed fewer rotational movements (21.8 ± 4.0 vs. 28.9 ± 7.8%; ES = –1.30) and started less often with the rotational movements (35.0 ± 3.6 vs. 40.5 ± 5.5; ES = –1.21) while the mean activity duration for a single rotation activity was shorter (2.1 ± 0.3 vs. 2.3 ± 0.3 s; ES = –0.67) than for international players. Differences in mobility performance among guard, forward and centre players were minimal. The results should help wheelchair basketball coaches specify wheelchair-handling training techniques and means to optimise wheelchair-athlete configurations.     

The scientometric world of Keith Pavitt: A tribute to his contributions to research policy and patent analysis

Keith Pavitt has made pioneering contributions to the study of science, technology and innovation. This paper aims to examine some of them on the basis of a bibliometric analysis of Keith Pavitt's work and the impact that he has had. First the paper follows how Pavitt's publication profile develops over time. Then we trace his most cited works and explore the sets of references in his papers. Author and journal co-citation maps illustrate the intellectual environment associated with Pavitt and the central role Research Policy played in this context. An analysis of the most frequently cited authors in Research Policy and Scientometrics underlines Keith Pavitt's role as both a shaper of, and a bridge between, science and technology policy and bibliometric analysis.     

The viralization of online education: Learning beyond the time of the coronavirus

PROSPECTS - In response to the global crisis resulted from the spread of the coronavirus in Brazil, many schools and universities suspended face-to-face classes and began to offer remote classes...     

The impact of body image and Afrocentric appearance on sexual refusal self-efficacy in early adolescent African American girls

Research examining the association between body image and sexual risk-taking has been mostly limited to clinical and/or White female samples. It is unclear whether body image plays a role in sexual risk-taking among African American early adolescent females. Moreover, research has neglected to consider body image within a cultural and ethnic framework. A positive sense of Afrocentric appearance may influence, either positively or negatively, sexual attitudes and behaviors among African American early adolescent girls. The purpose of this study, conducted with 156 urban African American early adolescent females, was to examine the relationships among body image, Afrocentric appearance, and sexual refusal self-efficacy. Results found no significant association between body image and sexual refusal self-efficacy. However, structural equation modeling found that a positive sense of Afrocentric appearance significantly predicted increased sexual refusal self-efficacy. Implications of this study in regard to culturally-based teenage pregnancy prevention and education initiatives are discussed.     

A novel μ-fluidic whole blood coagulation assay based on Rayleigh surface-acoustic waves as a point-of-care method to detect anticoagulants

A universal coagulation test that reliably detects prolonged coagulation time in patients, irrespective of the anticoagulant administered, has not been available to date. An easily miniaturised, novel μ-fluidic universal coagulation test employing surface acoustic waves (SAW) is presented here. SAW was employed to instantly mix and recalcify 6 μl citrated whole blood and image correlation analysis was used to quantify clot formation kinetics. The detection of clinically relevant anticoagulant dosing with old anticoagulants (unfractionated heparin, argatroban) and new anticoagulants (dabigatran, rivaroxaban) has been tested and compared to standard plasma coagulation assays. The applicability of this novel method has been confirmed in a small patient population. Coagulation was dose-proportionally prolonged with heparin, argatroban, dabigatran, and rivaroxaban, comparable to standard tests. Aspirin and clopidogrel did not interfere with the SAW-induced clotting time (SAW-CT), whereas the strong GPIIb/IIIa-inhibitor abciximab did interfere. Preliminary clinical data prove the suitability of the SAW-CT in patients being treated with warfarin, rivaroxaban, or dabigatran. The system principally allows assessment of whole blood coagulation in humans in a point-of-care setting. This method could be used in stroke units, emergency vehicles, general and intensive care wards, as well as for laboratory and home testing of coagulation.     

Average of trial peaks versus peak of average profile: impact on change of direction biomechanics

ABSTRACT

The aims of this study were twofold: firstly, to compare lower limb kinematic and kinetic variables during a sprint and 90° cutting task between two averaging methods of obtaining discrete data (peak of average profile vs. average of individual trial peaks); secondly, to determine the effect of averaging methods on participant ranking of each variable within a group. Twenty-two participants, from multiple sports, performed a 90° cut, whereby lower limb kinematics and kinetics were assessed via 3D motion and ground reaction force (GRF) analysis. Six of the eight dependent variables (vertical and horizontal GRF; hip flexor, knee flexor, and knee abduction moments, and knee abduction angle) were significantly greater (p ≤ 0.001, g = 0.10–0.37, 2.74–10.40%) when expressed as an average of trial peaks compared to peak of average profiles. Trivial (g ≤ 0.04) and minimal differences (≤ 0.94%) were observed in peak hip and knee flexion angle between averaging methods. Very strong correlations (ρ ≥ 0.901, p < 0.001) were observed for rankings of participants between averaging methods for all variables. Practitioners and researchers should obtain discrete data based on the average of trial peaks because it is not influenced by misalignments and variations in trial peak locations, in contrast to the peak from average profile.     

Intensity and physiological strain of competitive ultra-endurance exercise in humans

The aim of this study was to determine the magnitude and pattern of intensity, and physiological strain, of competitive exercise performed across several days, as in adventure racing. Data were obtained from three teams of four athletes (7 males, 5 females; mean age 36 years, s = 11; cycling .VO(2 peak) 53.9 ml . kg(-1) . min(-1), s = 6.3) in an international race (2003 Southern Traverse; 96 - 116 h). Heart rates (HR) averaged 64% (95% confidence interval: +/- 4%) of heart rate range [%HRR = (HR - HR(min))/(HR(max) - HR(min)) x 100] during the first 12 h of racing, fell to 41% (+/-4%) by 24 h, and remained so thereafter. The level and pattern of heart rate were similar across teams, despite one leading and one trailing all other teams. Core temperature remained between 36.0 and 39.2 degrees C despite widely varying thermal stress. Venous samples, obtained before, during, and after the race, revealed increased neutrophil, monocyte and lymphocyte concentrations (P < 0.01), and increased plasma volume (25 +/- 10%; P < 0.01) with a stable sodium concentration. Standardized exercise tests, performed pre and post race, showed little change in the heart rate-work rate relationship (P = 0.53), but a higher perception of effort post race (P < 0.01). These results provide the first comprehensive report of physiological strain associated with adventure racing.     

The advising system: An alternative model related to the evaluation of self-directed learning

The proposed advising model focuses on creative learning. To operationalize such a model, there must be not only structural but behavioral changes in the existing system. This requires that professional educators have special concern for the quality of relationships between faculty and students. In a program which focuses on creative learning, most students need assistance in developing the understanding and skill necessary for creative learning. An alternative advising model is proposed, therefore, which enhances the behavioral requirements. The alternative model views the advising function as a teaching-consulting function with a priority goal of helping the student learn the art of self-evaluation as a prerequisite to life-long learning.     

Testing Role Models’ Differential Effect on Use of Aggressive Compliance Gaining Strategies

Using a repeated measures design, this empirical study confirmed that a differential relationship exists between significant role models’ use of aggressive compliance gaining strategies (ACGS) and an individual’s use of the same in romantic and non-romantic interactions. As expected, peer use was found to have the strongest relationship to individual use of ACGS with romantic partners. Unexpected was the similarity in strength of parent and peer use to individual use of ACGS with non-romantic partners. Relevance and opportunity are mechanisms used to explain role model impact as an antecedent variable of ACGS use. Future studies to advance theory regarding aggressive communication are discussed.     

Teaching Preschoolers to Count: Effective Strategies for Achieving Early Mathematics Milestones

Attention to early childhood mathematics instructional strategies has sharpened due to the relatively poor mathematics performance of U.S. students in comparison to students from other countries and research evidence that early mathematics skills impact later achievement. Early Childhood counting skills form the foundation for subsequent mathematics learning. In this article, we discuss the milestones of counting development and examine preschool classroom mathematics observations through the lenses of two CLASS Dimensions, Concept Development and Instructional Learning Formats. Recommendations for effective instructional strategies around counting and suggestions for incorporating mathematics instruction into storybook reading are provided.