797 research outputs found
Evaluation of sustainability-oriented transversal competencies in engineering postgraduate studies
[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
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: 13.33â±â0.85 years old; 11 boys: 13.5â±â0.75 years old; 16 girls: 13.2â±â0.92 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: 68.72â±â5.57â
s, 66.23â±â5.23â
s; Îâ=â-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 (pâ<â.001), except the TV-SL and the TV-SF path. At M3, all links between variables presented significant effects (pââ€â.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: Ï2/dfâ=â3.82; M2: Ï2/dfâ=â3.08; M3: Ï2/dfâ=â4.94). 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
The aim of this study was to assess the: (i) gender; (ii) performance and; (iii) gender versus performance interactions in young swimmersâ 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
Monitoring the training process represents an important task during sports preparation. However, not always the applied protocols help to address the coachesâ 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
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?
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 âą. 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
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
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?
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
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 mâs-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 swimmersâ 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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