Cycling shoe aerodynamics     

Giuseppe Gibertini  Donato Grassi  Carlo Macchi  Giuseppe De Bortoli 《Sports Engineering》2010,12(3):155-161

The present paper describes the activity carried out to investigate the aerodynamic effects of cycling shoes for time trial competitions. This subject has not been widely studied but can be important for an accurate aerodynamic optimisation of a time trial cyclist. The study was carried out by means of wind tunnel testing: an appropriate test setup and an appropriate test procedure (based on “effective angle of attack approach”) were developed in order to produce realistic test conditions. The developed testing procedure was applied to two different shoe models, differently fastened. Furthermore, an important point was the investigation of the overshoe effect. The results showed that the power required to overcome the shoe’s drag is almost a tenth of the total power and that differences between the shoes can affect the cyclist’s performance.  相似文献   

Development of a cultural self-efficacy scale for adolescents (CSES-A)     

Elena Briones  Carmen Tabernero  Carlo Tramontano  Gian Vittorio Caprara  Alicia Arenas 《Int J Intercult Relat》2009,33(4):301-312

We developed a cultural self-efficacy scale for adolescents (CSES-A) and tested its psychometric properties using both exploratory and confirmatory factor analyses. Cultural self-efficacy (CSE) was defined as person's perception of his/her own capability to function effectively in situations characterized by cultural diversity. On the basis of Bandura's guideline for the development of a domain-specific self-efficacy measure, we tailored 50 items after reviewing literature about cultural competence, adolescents’ school-problems and social self-efficacy scales developed in previous studies in intercultural contexts. After pre-testing and analyzing psychometric properties of the scale, we selected 33 items. Eight hundred sixty-eight adolescents with five different cultural origins completed a set of questionnaires, including the CSES-A, internal control expectancies, general self-efficacy, academic expectancies, number of people from diverse cultures they keep in touch with, acculturation attitudes, perceived enrichment of other cultures, acculturation stress and demographic data. An EFA with MPLUS 2.14 highlighted a five-factor solution with 25 items that was supported by a subsequent CFA. The five factors were: self-efficacy in mixing satisfactorily with other cultures, in understanding different ways of life, in processing information from other cultures, in coping with loneliness and in learning and understanding other languages. The pattern of correlation with internal control expectancies, general self-efficacy and cultural variables supported the validity of the scale. CSES-A may be useful for future research on multicultural contexts, in which self-efficacy in cultural adaptation could be a fundamental variable.  相似文献   

Factors influencing physiological responses to small-sided soccer games   总被引：3，自引：2，他引：1  

Rampinini E  Impellizzeri FM  Castagna C  Abt G  Chamari K  Sassi A  Marcora SM 《Journal of sports sciences》2007,25(6):659-666

The aim of this study was to examine the effects of exercise type, field dimensions, and coach encouragement on the intensity and reproducibility of small-sided games. Data were collected on 20 amateur soccer players (body mass 73.1 +/- 8.6 kg, stature 1.79 +/- 0.05 m, age 24.5 +/- 4.1 years, VO(2max) 56.3 +/- 4.8 ml x kg(-1) x min(-1)). Aerobic interval training was performed during three-, four-, five- and six-a-side games on three differently sized pitches, with and without coach encouragement. Heart rate, rating of perceived exertion (RPE) on the CR10-scale, and blood lactate concentration were measured. Main effects were found for exercise type, field dimensions, and coach encouragement (P < 0.05), but there were no interactions between any of the variables (P > 0.15). During a six-a-side game on a small pitch without coach encouragement, exercise intensity was 84 +/- 5% of maximal heart rate, blood lactate concentration was 3.4 +/- 1.0 mmol x l(-1), and the RPE was 4.8. During a three-a-side game on a larger pitch with coach encouragement, exercise intensity was 91 +/- 2% of maximal heart rate, blood lactate concentration was 6.5 +/- 1.5 mmol x l(-1), and the RPE was 7.2. Typical error expressed as a coefficient of variation ranged from 2.0 to 5.4% for percent maximal heart rate, from 10.4 to 43.7% for blood lactate concentration, and from 5.5 to 31.9% for RPE. The results demonstrate that exercise intensity during small-sided soccer games can be manipulated by varying the exercise type, the field dimensions, and whether there is any coach encouragement. By using different combinations of these factors, coaches can modulate exercise intensity within the high-intensity zone and control the aerobic training stimulus.  相似文献   

Preservation of visual attention in older expert orienteers at rest and under physical effort   总被引：1，自引：0，他引：1  

Pesce C  Cereatti L  Casella R  Baldari C  Capranica L 《运动与训练心理学杂志》2007,29(1):78-99

This study investigated the visual attention of older expert orienteers and older adults not practicing activities with high attentional and psychomotor demands, and considered whether prolonged practice of orienteering may counteract the age-related deterioration of visual attentional performance both at rest and under acute exercise. In two discriminative reaction time experiments, performed both at rest and under submaximal physical workload, visual attention was cued by means of spatial cues of different sizes followed, at different stimulus-onset asynchronies, by compound stimuli with local and global target features. Orienteers, as compared to nonathletes, showed a faster reaction speed and a complex pattern of attentional differences depending on the time constraints of the attentional task, the demands on endogenous attentional control, and the presence or absence of a concomitant effortful motor task. Results suggest that older expert orienteers have developed attentional skills that outweigh, at least at rest, the age-related deficits of visual attentional focusing.  相似文献   

Building the scholarship of next generation information professional     

John Carlo Bertot  Paul T. Jaeger  John A. Shuler 《Government Information Quarterly》2012

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High-throughput size-based rare cell enrichment using microscale vortices   总被引：2，自引：0，他引：2  

Hur SC  Mach AJ  Di Carlo D 《Biomicrofluidics》2011,5(2):22206

Cell isolation in designated regions or from heterogeneous samples is often required for many microfluidic cell-based assays. However, current techniques have either limited throughput or are incapable of viable off-chip collection. We present an innovative approach, allowing high-throughput and label-free cell isolation and enrichment from heterogeneous solution using cell size as a biomarker. The approach utilizes the irreversible migration of particles into microscale vortices, developed in parallel expansion-contraction trapping reservoirs, as the cell isolation mechanism. We empirically determined the critical particle∕cell diameter D(crt) and the operational flow rate above which trapping of cells∕particles in microvortices is initiated. Using this approach we successfully separated larger cancer cells spiked in blood from the smaller blood cells with processing rates as high as 7.5×10(6) cells∕s. Viable long-term culture was established using cells collected off-chip, suggesting that the proposed technique would be useful for clinical and research applications in which in vitro culture is often desired. The presented technology improves on current technology by enriching cells based on size without clogging mechanical filters, employing only a simple single-layered microfluidic device and processing cell solutions at the ml∕min scale.  相似文献   

Response to “Government information in the digital age: The once and future Federal Depository Library Program”     

John A. ShulerPaul T. Jaeger  John Carlo Bertot 《Government Information Quarterly》2011,28(1):e2

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Overeducation among European University Graduates: a comparative analysis of its incidence and the importance of higher education differentiation     

Carlo Barone  Luis Ortiz 《Higher Education》2011,61(3):325-337

The incidence of overeducation in eight European countries is here assessed by means of multiple indicators. With the exception of Spain, the results reveal that overeducation is a minor risk amongst European tertiary graduates. Yet, the contrast between different indicators reveals the existence of an overeducation of a moderate kind in countries with high rates of tertiary attainment (Norway, Finland and Netherlands). Our results also reveal the importance of higher education differentiation for understanding the risk of overeducation. Graduates from humanistic fields, bachelor courses and vocational colleges are more exposed to overeducation, though their disadvantage varies cross-nationally.  相似文献   

A Class-Wide Intervention for Improving Homework Performance     

Lea A. Theodore PhD  Richard J. DioGuardi PhD  Tammy L. Hughes PhD  Danielle Aloiso PsyD  Melissa Carlo  Darren Eccles 《Journal of educational and psychological consultation》2013,23(4):275-299

Homework completion has an important impact on the overall academic functioning of students. Consultation requests often center on identifying efficient interventions so that teachers may facilitate the homework process and enhance students' academic achievement. This investigation employed a randomized interdependent group contingency and randomized reinforcers to improve homework completion and accuracy of spelling performance in 21 elementary school students. An ABAB reversal design across all students was employed. Results showed this intervention to have a positive impact on both spelling homework completion and accuracy rates. Limitations, future research, and contributions are addressed.  相似文献   

Bringing voice to the next generation information professional     

John Carlo Bertot 《Government Information Quarterly》2013

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