Eccentric flywheel post-activation potentiation influences swimming start performance kinetics

This study aimed to assess the effects of post-activation potentiation in the strength related variables of a kick start. Thirteen competitive swimmers performed three kick starts after a standardized warm up (denoted USUAL) and another after inducing post-activation through five isotonic repetitions on an eccentric flywheel (denoted PAP). A T-test was used to quantify differences between USUAL and PAP warm up. The best trial of each subject achieved by natural conditions (denoted PEAK) was compared with data obtained after PAP. An instrumented starting block with independent triaxial force plates, collected the strength variables related with the impulse at take off. Improvements in the vertical components of force were observed after PAP compared with USUAL, meanwhile no differences were detected on the horizontal components of it. The velocity at take off was higher after PAP compared with USUAL (4.32 ± 0.88 vs 3.93 ± 0.60 m*s-1; p = 0.02). No differences in force or velocity were detected comparing PAP with PEAK (4.13 ± 0.62 m*s-1, p = 0.11). The PAP warm-up increased vertical force and it was transferred to a higher resultant velocity at take-off. This improvement would equal the best result possible obtained in natural conditions after some trials.     

The PCC ISNI Pilot: Exploring Identity Management on a Global,Collaborative Scale

Abstract

The Program for Cooperative Cataloging (PCC) conducted a multi-institution Pilot project to contribute metadata to the International Standard Name Identifier (ISNI) database. In addition to describing the goals, structure, and activities undertaken in the Pilot, this article examines some of the experiences of PCC metadata practitioners as they sought to incorporate ISNIs into their metadata workflows and pursue a wide range of ISNI use cases. Lastly, the article outlines next steps that flowed from the Pilot as the PCC has parlayed its newly developing identity management expertise into additional PCC program explorations.     

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.     

Analysis of doping control test results in individual and team sports from 2003 to 2015

Background:Determining the prevalence of doping in sport might be useful for anti-doping authorities to gauge the effectiveness of anti-doping policies implemented to prevent positive attitudes toward doping.Using questionnaires and personal interviews,previous investigations have found that the prevalence of doping might be different among different sports disciplines;however,there is no sport-specific information about the proportion of adverse and atypical findings(AAF) in samples used for doping control.The aim of the present investigation was to assess the differences in the frequency of adverse analytical and atypical findings among sports using the data made available by the World Anti-Doping Agency.Methods:The data included in this investigation were gathered from the Testing Figures Reports made available annually from 2003 to 2015 by the World Anti-Doping Agency.These Testing Figures Reports include information about the number of samples analyzed,the number of AAFs reported,and the most commonly found drugs in the urine and blood samples analyzed.A total of 1,347,213 samples were analyzed from the individual sports selected for this investigation,and 698,371 samples were analyzed for disciplines catalogued as team sports.Results:In individual sports,the highest proportions of AAF were 3.3%±1.0% in cycling,3.0%±0.6% in weightlifting,and 2.9%±0.6% in boxing.In team sports,the highest proportions of AAF were 2.2%±0.5% in ice hockey,2.0%±0.5% in rugby,and 2.0%±0.5% in basketball.Gymnastics and skating had the lowest proportions at(≤1.0%) for individual sports,and field hockey,volleyball and football had the lowest proportions for team sports(≤1.4%).Conclusion:As suggested by the analysis,the incidence of AAF was not uniform across all sports disciplines,with the different proportions pointing to an uneven use of banned substances depending on the sport.This information might be useful for increasing the strength and efficacy of anti-doping policies in those sports with the highest prevalence in the use of banned substances.     

Academic productivity of African Americans in criminology and criminal justice

This study explores the productivity of African American scholars in the field of criminology during the period of 1987 through 1998. Issues about the relative benefits of mentoring are explored. The impact of external and internal barriers with respect to authorship are also addressed. Journals included in the study were randomly selected from a list of criminology and criminal justice journals. Authorship order is also identified, that is, we look at primary, secondary and tertiary authorships by African American faculty as well. Findings provide empirical evidence that the contributions of African American faculty do not appear in many mainstream journals. The reasons behind the under representation are explored.     

“Spanish as a foreign language” teachers’ profiles: inclusive beliefs, teachers’ perceptions of student outcomes in the TCLA program, burnout, and experience

The present study focuses on the Temporary Classroom of Linguistic Adaptation program (TCLA program) in which specialist teachers (Spanish as a foreign language teachers—SFL teachers) teach Spanish to immigrants who are not proficient in the language. We suggest that support for immigrant students in Spanish schools should adopt a new inclusive educational approach. The present investigation is a preliminary attempt at characterizing the profiles of SFL teachers by assessing, simultaneously, five relevant variables (through cluster analysis): inclusive beliefs, teachers’ perceptions of student outcomes in TCLA program, general burnout, diversity-related teacher burnout, and years of teaching experience. Eighty-one SFL teachers from 132 schools in Spain (EU) were asked to complete a self-report questionnaire. Cluster analysis found two clearly differentiated groups: the larger one, Innovative SFL Teachers and the smaller, Traditional SFL Teachers. The Traditional SFL Teachers are characterized by more years of experience, lower inclusive beliefs scores, lower teachers’ perception of student outcomes in the TCLA program scores, and higher burnout scores as compared with the Innovative SFL Teachers. Moreover, Traditional SFL Teachers conceptualize their teaching role as a "teacher of Spanish" whereas Innovative SFL Teachers see themselves much more as playing a supportive role.