797 research outputs found

    Evaluation of sustainability-oriented transversal competencies in engineering postgraduate studies

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    [EN] In recent times, education for sustainability is gaining more and more relevance in the field of engineering. One of the recently established Sustainable Development Goals explicitly calls for the achievement of sustainable infrastructures by 2030. Infrastructures are recognised as a crucial element towards a sustainable future, as they are responsible for a vast amount of environmental damages and economic expenses, but also are considered to be essential to achieve social welfare and the economic development of regions. Sustainable design of infrastructures requires a paradigm shift in the way engineering students are taught how to face design problems. The complex relation that exists between the conflicting dimensions in which sustainability is founded, namely economy, environment and society, requires of future engineers to develop a series of transversal competencies during their postgraduate studies. However, there are no objective criteria on which to base the assessment of the degree of acquisition of these skills. This paper presents an objective methodology for the evaluation of one of the key competencies required for sustainability-oriented future engineers, namely critical thinking. The proposed methodology is based on the evaluation of the coherency expressed by the students when dealing with a sustainability-related design problem. Such consistency shall be mathematically quantified by means of the Analytic Hierarchy Process. Through the resolution of a particular case study, where students are required to complete a survey comparing different sustainability criteria pairwise, the professor is able to obtain a consistency index from the comparison matrices derived from the survey results of each student. Such indicator is a valuable tool to assess both the clarity with which students perceive sustainability as well as their ability to meet the new challenges that the society will face in the near future.The authors acknowledge the financial support of the Spanish Ministry of Economy and Competitiveness, along with FEDER funding (Project: BIA2017-85098-R).Navarro, I.; SĂĄnchez-Garrido, A.; Yepes, V. (2020). Evaluation of sustainability-oriented transversal competencies in engineering postgraduate studies. IATED Academy. 2181-2187. https://doi.org/10.21125/iceri.2020.0522S2181218

    The transfer of strength and power into the stroke biomechanics of young swimmers over a 34-week period

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    The purpose of this study was to learn the interplay between dry-land strength and conditioning, and stroke biomechanics in young swimmers, during a 34-week training programme. Twenty-seven swimmers (overall: 13.33 ± 0.85 years old; 11 boys: 13.5 ± 0.75 years old; 16 girls: 13.2 ± 0.92 years old) competing at regional- and national-level competitions were evaluated. The swimmers were submitted to a specific in-water and dry-land strength training over 34 weeks (and evaluated at three time points: pre-, mid-, and post-test; M1, M2, and M3, respectively). The 100-m freestyle performance was chosen as the main outcome (i.e. dependent variable). The arm span (AS; anthropometrics), throwing velocity (TV; strength), stroke length (SL), and stroke frequency (SF; kinematics) were selected as independent variables. There was a performance enhancement over time (M1 vs. M3: 68.72 ± 5.57 s, 66.23 ± 5.23 s; Δ = -3.77%; 95% CI: -3.98;-3.56) and an overall improvement of the remaining variables. At M1 and M2, all links between variables presented significant effects (p < .001), except the TV-SL and the TV-SF path. At M3, all links between variables presented significant effects (p ≀ .05). Between M1 and M3, the direct effect of the TV to the stroke biomechanics parameters (SL and SF) increased. The model predicted 89%, 88%, and 92% of the performance at M1, M2, and M3, respectively, with a reasonable adjustment (i.e. goodness-of-fit M1: χ2/df = 3.82; M2: χ2/df = 3.08; M3: χ2/df = 4.94). These findings show that strength and conditioning parameters have a direct effect on the stroke biomechanics, and the latter one on the swimming performance.We would like to thank the support of the University of Beira Interior and SantanderUniversities (Bolsa BIPD/ ICI-FCSH-Santander Universidades-UBI/2017)info:eu-repo/semantics/acceptedVersio

    The influence of anthropometric, kinematic and energetic variables and gender on swimming performance in youth athletes

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    The aim of this study was to assess the: (i) gender; (ii) performance and; (iii) gender versus performance interactions in young swimmers’ anthropometric, kinematic and energetic variables. One hundred and thirty six young swimmers (62 boys: 12.76 ± 0.72 years old at Tanner stages 1-2 by self-evaluation; and 64 girls: 11.89 ± 0.93 years old at Tanner stages 1-2 by self-evaluation) were evaluated. Performance, anthropometrics, kinematics and energetic variables were selected. There was a non-significant gender effect on performance, body mass, height, arm span, trunk transverse surface area, stroke length, speed fluctuation, swimming velocity, propulsive efficiency, stroke index and critical velocity. A significant gender effect was found for foot surface area, hand surface area and stroke frequency. A significant sports level effect was verified for all variables, except for stroke frequency, speed fluctuation and propulsive efficiency. Overall, swimmers in quartile 1 (the ones with highest sports level) had higher anthropometric dimensions, better stroke mechanics and energetics. These traits decrease consistently throughout following quartiles up to the fourth one (i.e. swimmers with the lowest sports level). There was a non-significant interaction between gender and sports level for all variables. Our main conclusions were as follows: (i) there are non-significant differences in performance, anthropometrics, kinematics and energetics between boys and girls; (ii) swimmers with best performance are taller, have higher surface areas and better stroke mechanics; (iii) there are non-significant interactions between sports level and gender for anthropometrics, kinematics and energetics

    Training evaluation in male age-group swimmers

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    Monitoring the training process represents an important task during sports preparation. However, not always the applied protocols help to address the coaches’ concerns, namely regarding its complexity and difficulty to be used in large samples. Therefore, the aim of this study was to apply a simple protocol to control the training process in a group of male age-group swimmer

    High glucose and diabetes increase the release of [3H]-D-aspartate in retinal cell cultures and in rat retinas

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    Several evidences suggest that glutamate may be involved in retinal neurodegeneration in diabetic retinopathy (DR). For that reason, we investigated whether high glucose or diabetes affect the accumulation and the release of [3H]-D-aspartate, which was used as a marker of the glutamate transmitter pool. The accumulation of [3H]-D-aspartate did not change in cultured retinal neural cells treated with high glucose (30 mM) for 7 days. However, the release of [3H]-D-aspartate, evoked by 50 mM KCl, significantly increased in retinal cells exposed to high glucose. Mannitol, which was used as an osmotic control, did not cause any significant changes in both accumulation and release of [3H]-D-aspartate. In the retinas, 1 week after the onset of diabetes, both the accumulation and release of [3H]-D-aspartate were unchanged comparing to the retinas of agematched controls. However, after 4 weeks of diabetes, the accumulation of [3H]-D-aspartate in diabetic retinas decreased and the release of [3H]-Daspartate increased, compared to age-matched control retinas. These results suggest that high glucose and diabetes increase the evoked release of D-aspartate in the retina, which may be correlated with the hypothesis of glutamate-induced retinal neurodegeneration in DR

    Is leg kicking workout position affecting kinematic and hydrodynamic variables in front-craw?

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    Swimming training includes leg kicking workouts, whereas swimmerschoose betweenhead out (RO) or headin (HI) position holding afllitter kick board. Ourobjective was to characterize andanalyse differences between the t\vo legkicking positions in Swimming Vdocity (Y, 1n m/s), lntra-cyclic variation of the horizontal velocity (dv, dimensionless), Active Drag (D, in N), Hydrodynamic Coefficient (CD ‱. dimensionless), Mechanical Power (P, in W) andfrontal surfacearea (FSA, ia m2). Thirteen swimmers (15.3 ± 2,9 years~old) participated in thisstudy. Frontal surface area was calculated according to the proposal of Morais et aI. (201l)byphotogrammetry. Aftefa standard warmup, swimmers performed 4x25mbouts at maximum velocity as follows: i) 2XcrawI HO Ieg-kick; ii) 2XcrawI HI Ieg-kick. ln the first bout ofeach the V and the dv were measured usingaspeedmeter cable that Was attached to lhe swimmer's hip (Barbosaet aI., 2013). In the secondbout CD was obtained through the velocity perturbation method (Kolmogorov and Duplishcheva, 1992).info:eu-repo/semantics/publishedVersio

    Kinematical changes in swimming front crawl and breaststroke with the AquaTrainerÂź snorkel

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    The aim of the present study was to assess the kinematical changes when swimming maximal bouts in Front Crawl and Breaststroke with the AquaTrainerÂź snorkel. Thirteen male swimmers (7 at Breaststroke and 6 at Front Crawl) of national level performed randomly two maximal bouts of 100-m swims: one bout using the Aqua- TrainerÂź snorkel (snorkel swim) and another one without the snorkel (free swim). The swims were videotaped in sagital plane with a pair of cameras providing 2D kinematics evaluation. The following measures were assessed: swimming performance (T100), stroke cycle period (P), stroke rate (SR), stroke length (SL), swimming velocity (v), swimming eYciency as estimated by the stroke index (SI), speed Xuctuation (dv) and the mathematical characterisation of dv. T100 was signiWcantly higher when swimming with the snorkel than in free swimming at Breaststroke (= 6.26%) and at Front Crawl (= 4.75%). P, SR and SL, as well as SI and dv did not present signiWcant diVerences. The main Wnding of the study was that changes in the swimming velocity imposed by the use of the AquatrainerÂź do not seem due to changes in general kinematics or swimming eYcienc

    Linking selected variables with direct and indirect effect on young swimmer's performance

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    One of the main goals of swimming research is to identify the scientific domains and/or variables that predict swimming performance in children (i.e., young athletes) in the perspective of detecting future talents (1). Nevertheless, research in young athletes should be less invasive, expensive and timeconsuming than in adult/elite counterparts (2). In this sense, several authors (2-4) on regular basis estimate and/or measure variables in different scientific domains (i.e., anthropometric, hydrodynamic, kinematical and energetic) that are easy to collect and might predict performance and/or detect talented swimmers.info:eu-repo/semantics/publishedVersio

    Can 8 weeks of training in female swimmers affect active drag?

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    Hydrodynamic drag is the force that a swimmer has to overcome in order to maintain his movement through water and is influenced by velocity, shape, size and the frontal surface area Thus, the aim of this study was to assess the effects of 8 weeks of training on active drag in young female swimmers. 8 female age group swimmers belonging to the same swimming club participated in this study. Active drag measurements were conducted in two different trials: at the beginning of the season and after 8 weeks of training. The velocity perturbation method was used to determine active drag in front crawl swimming. After 8 weeks of training, mean active drag decreased, although no significant differences were found between the two trials. No significant differences were observed in swimming velocity between the two trials. It seems that 8 weeks of swimming training were not enough to allow significant improvements on swimming technique. One can recommend that specific training sets concerning technique correction and improvement in young swimmers should be a main aim during training planning

    Agreement between different methods to measure the active drag coefficient in front-crawl swimming

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    The aim of this study was to analyze the agreement of the active drag coefficient measured through drag and propulsion methods. The sample was composed of 18 swimmers (nine boys: 15.9 ± 0.9 years; nine girls: 15.3 ± 1.2 years) recruited from a national swimming team. The velocity perturbation method was used as the drag measurement system and the Aquanex system as the propulsion system. For both sexes combined, the frontal surface area was 0.1128 ± 0.016 m2, swim velocity 1.54 ± 0.13 m∙s-1, active drag 62.81 ± 11.37 N, propulsion 68.81 ± 12.41 N. The level of the active drag coefficient agreement was calculated based on the mean values comparison, simple linear regression, and Bland Altman plots. The mean data comparison revealed non-significant differences (p > 0.05) between methods to measure the active drag coefficient. Both the linear regression (R2 = 0.82, p < 0.001) and Bland Altman plots revealed a very high agreement. The active drag coefficient should be the main outcome used in the interpretation of the swimmers’ hydrodynamic profile, because it is less sensitive to swimming velocity. Coaches and researchers should be aware that the active drag coefficient can also be calculated based on propulsion methods and not just based on drag methods. Thus, the swimming community can now use different equipment to measure the hydrodynamics of their swimmersThis work was supported by national funds (FCT - Portuguese Foundation for Science and Technology) under the project UIDB/DTP/04045/2020info:eu-repo/semantics/publishedVersio
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