689 research outputs found

    Gender differences and age-related changes in performance at the duathlon world champions

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    Analyze the differences in performance between genders, and changes in performance in age group category at Short distance during the ITU Duathlon World Championships held between 2005 and 2016.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Effects of a strength and stretching program, combined or Iisolated, on active flexibility in physical education setting.

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    Purpose. To examine the effects of a two-session-per-week strength and stretching program on sit and reach score among high-school students in the physical education setting. Methods. A sample of 46 high-school students (16 girls and 30 boys) aged 12-14 years from four classes were clustered and randomly assigned to a strength group (n=8), a stretching group (n=12), a strength + stretching group (n=16) or a control group (n=10). During physical education classes, the experimental students performed a 1-minute stretching, a 1-minute strength or a 2-minutes strength + stretching program twice a week a total of 20 weeks. Control students performed the same physical education classes, but they did not follow any strength and/or stretching program. Active flexibility (estimated by the classic sit-and-reach test) was assessed at the beginning and at the end of the intervention program. Results. The Wilcoxon test results showed that students that performed a combined strength and stretching program increased statistically significantly their active flexibility levels from pre-intervention to post-intervention (∆ = 1.8 ± 3.2 cm; p 0.05). Conclusiones. Since in physical education many curricular contents need to be developed each academic year and the subject is also restricted by its limited curriculum time allocation, teachers could improve students’ flexibility combining stretching and strength workout. Therefore, in addition to the improvement of students’ flexibility levels, this intervention program might permit regular development of other physical education curricular contents.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Differences according to modalities, distances and genders of how the triathletes carry their bicycles for the boxes during the first transition in the Spanish Championships

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    Introduction The purpose was to compare the proportion in the use (by elite or pro category) of the 4 types of hold-riding the bicycle during the transition between triathletes’ sex (men and women), distance or modality (Olympic, sprint, long and cross) at the Triathlon Spanish Championships. Method The sample was composed by 648 Spanish triathletes, participants of eight elite Spanish championship triathlon during 2016. Results Most of triathletes hold-ride the bike by the seat only while driving it (76.2%), followed by the handlebar (14.9%), seat-handlebar (7.1%) and stem styles (1.9%). The same tendency was showed within sex, category and race subcategories, except for Olympic (seat style was used for the 95% of triathletes), sprint (seat and handlebar styles were similar), and long (seat-handlebar and stem styles were equal). The results showed that there were statistically significantly differences in the proportion of triathletes that used each hold-riding of the bicycle between sex, race, and sex-race subcategories (p 0.05; Cramer´s V = 0.000-0.244). Discussion The difference between men and women is that men have twice the grip on the handlebars. The videos show that this may be because the groups of men in the boxes are greater than those of the women, and this sometimes forces them, to take the bike by the handlebar to control it better and avoid incidents. While in the Olympic, sprint and long-distance elite triathletes mostly used the seat style, and in the cross race the handlebar style.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Comparison of the effect of a Physical Education-Based Stretching Program applied during the Warm-Up, ColdDown and both periods on hamstring extensibility in Primary Schoolchildren.

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    Purpose. To compare the effects of a physical education-based stretching program applied during the warm-up, cold-down and both periods on hamstring extensibility in primary schoolchildren. Methods. A sample of 237 schoolchildren aged 7-12 years old (128 girls and 109 boys) from two primary school centres participated in the present study and met satisfactorily the inclusion and exclusion criteria. A cluster randomized controlled trial design was used. The classes balanced by grade were randomly assigned to the warm-up (n = 57), cold-down (n = 55), both periods (n = 61) or control groups (n = 64). During the physical education sessions, the students from the interventional groups performed a four-minute stretching program twice a week for eight weeks. The intervention program was applied during the warm-up (4 minutes), cold-down (4 minutes) and warm-up (2 minutes)-cold-down (2 minutes) for the warm-up, cold-down and both periods groups, respectively. Hamstring extensibility (estimated by the back-saver sit-and-reach test) was assessed at the beginning and at the end of the intervention program. Results. The one-way ANOVA (p 0.05). Conclusions. In order to develop students’ flexibility, PE teachers should apply stretching programs during the cold-down period. Due to the negative effect of static stretching on performance as previously found in the literature, it seems that PE teachers should improve students´ flexibility during the cool-down period of the sessions.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Effect of the adsorbate stiffness on the resonance response of microcantilever sensors

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    The authors present a theoretical model to predict the resonance frequency shift due to molecule adsorption on micro- and nanocantilevers. They calculate the frequency shift experienced by cantilevers made of either silicon or the polymer SU-8, when two adsorbates, myosin protein and an alkanethiol, are attached to the cantilever surface. They demonstrate that the effect of the adsorbate stiffness can be comparable or even larger than the mass effect, producing positive frequency shifts. The results provide methods for decoupling both opposite effects and routes for the design of resonators with high sensitivity to molecule adsorption based on either stiffness or mass effects.Peer reviewe

    Origin of the response of nanomechanical resonators to bacteria adsorption

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    Resonant microcantilevers are being actively investigated as sensitive mass sensors for biological detection. By performing experiments of adsorption of the bacteria Escherichia coli on singly clamped microcantilevers, we demonstrate that the effect of the added mass is not the only and may not be the main origin of the response of these sensors. The experiments show that the magnitude and sign of resonance frequency shift both depend critically on the distribution of the adsorbed bacterial cells on the cantilever. We relate this behavior to the added mass that shifts the resonance to lower frequencies and the higher effective flexural rigidity of the cantilever due to the bacteria stiffness that shifts the resonance to higher frequencies. Both effects can be uncoupled by positioning the cells where each effect dominates, near the free cantilever end for measuring the added mass or near the clamping for measuring the increase of flexural rigidity.One of the authors (D.R.) acknowledges the fellowship funded by the Autonomic Community of Madrid. This work was supported by the Spanish National Research Council (CSIC), Project No. 200550M056.Peer reviewe

    Empathy in students of Kinesiology

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    Introduction: empathy is an important concept in the interaction between the Kinesiologist and the patient. Objective: to determine the levels of empathy in students of Kinesiology considering the variables course and gender from the School of Health Sciences, University of Atacama (Chile) in November 2018. Methods: exploratory and cross-sectional study. A sample of 191 students was included in the study. The Jefferson's Empathy scale was used. The median, quartile 1 and 3, inter-quartile difference and confidence interval of the median were estimated. The possible differences regarding empathy were studied using nonparametric tests (Mood Median). Results: there were differences in empathy in the course variable. Empathy was not different concerning gender variable. Conclusions: levels of empathy, along with the levels of interest showed differences between courses and there are no differentiation concerning empathy between genders

    Silicon nanowires: where mechanics and optics meet at the nanoscale

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    Mechanical transducers based on nanowires promise revolutionary advances in biological sensing and force microscopy/spectroscopy. A crucial step is the development of simple and non-invasive techniques able to detect displacements with subpicometer sensitivity per unit bandwidth. Here, we design suspended tapered silicon nanowires supporting a range of optical resonances that confine and efficiently scatter light in the visible range. Then, we develop an optical method for efficiently coupling the evanescent field to the regular interference pattern generated by an incoming laser beam and the reflected beam from the substrate underneath the nanowire. This optomechanical coupling is here applied to measure the displacement of 50 nm wide nanowires with sensitivity on the verge of 1 fm/Hz1/2 at room temperature with a simple laser interferometry set-up. This method opens the door to the measurement of the Brownian motion of ultrashort nanowires for the detection of single biomolecular recognition events in liquids, and single molecule spectroscopy in vacuum.We acknowledge financial support from the Spanish Science Ministry (MINECO) through projects TEC2011-29120-C05-04; and from European Research Council through Starting Grant NANOFORCELLS (ERC-StG-2011-278860).Peer reviewe

    Análisis de la producción científica latinoamericana sobre estrés docente (2010 – 2018)

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    The purpose of this research was to evaluate the scientific production on teacher stress. It is a cross-sectional descriptive study of articles published in journals indexed in the SciELO collection between 2010 and 2018. An estimate of publications per year, journals, institutional affiliations and publication topics was analyzed. It was found that between the aforementioned years, 60 articles on the subject have been published, out of which the years of greatest production fluctuate between 2014 and 2018. The main journals that published articles on this topic are: Research News in Education, Uninorte Health Magazine and the Magazine of Medical Sciences of Pinar del Río in Cuba. In addition, Brazil, Colombia and Cuba have the institutional affiliations with the highest number of published articles. We can conclude that teacher stress as a research variable has been studied gradually in Latin American countries; however, it is necessary to continue strengthening these studies in other databases.La presente investigación tuvo como objetivo evaluar la producción científica sobre estres docente. Es un estudio descriptivo transversal de los artículos publicados en revistas indizadas en la colección SciELO entre los años 2010 y 2018. Se analizó estimación de publicaciones por año, revistas, afiliaciones institucionales y temáticas de publicación. Se encontró que entre los años mencionados se han publicado 60 artículos sobre la temática, de los cuales los años de mayor producción fluctuan entre 2014 a 2018, las principales revistas de publicación sobre este tópico son: Actualidades Investigativas en Educación, Revista Salud Uninorte y Revista de Ciencias Médicas de Pinar del Río; además Brasil, Colombia y Cuba son los afiliaciones a instituciones de estos países con mayor cantidad de artículos publicaods. Podemos concluir que el estres docente como variable de investigación viene siendo estudiado de a poco en países latinoamericanos; sin embargo, es necesario seguir fortaleciendo estos estudios en demás bases de datos
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