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  • Author: Carlos Rodríguez x
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Approach to students’ social representations in the construction of academic European geography: A case study of Spanish university students

Abstract

This article provides the results of classroom research involving university students training to be secondary school teachers of geography and history. The research is based on the analysis of a word association test on Europe and the European Union. The results constitute an approach to the geographical and historical representations these students have of their own European continent. This is a fundamental question considering that this collective group is training to teach the contents and values of European geography in secondary school education. From here on, our intention is no other than to carry out an exercise of synthesis and overall reflection on the test results and introduce issues which could generate some debate in the educational community.

Open access
Sensitivity to diazepam after a single session of forced swim stress in weaning Wistar rats

Abstract

The present study investigated the sensitivity to stress and diazepam in weaning (21-day old) Wistar rats. A single 15-min session of forced swimming was used to induce anxiety-like behavior. The group that was forced to swim exhibited an increase in anxiety-like behavior in the elevated plus maze (EPM) and open field test (OFT) compared to the non-stressed group. Diazepam (1 h before the tests) reduced anxiety-like behavior in rats forced to swim compared to the vehicle stressed group. The dose-response curve for diazepam indicated that the 0.5 mg kg−1 dose (1 h before the EPM and OFT) was the minimum effective dose in reducing anxiety-like behavior without altering locomotor activity in weaning rats. These results indicate that weaning rats can develop anxiety-like behavior after a brief, single session of stress, and that rats at this age are seemingly more sensitive to diazepam than adult rats, which may be taken into account for clinical applications.

Open access
Effects of Core Strength Training Using Stable and Unstable Surfaces on Physical Fitness and Functional Performance in Professional Female Futsal Players

Abstract

The aim of this study was to assess the effect of core strength training performed on a stable surface (CTS) compared with core strength training performed on an unstable surface (CTU) on physical fitness (jump performance, sprint, and repeated sprint ability (RSA)) and quality of movement (Fundamental Movement Screen) in professional female futsal players. Fourteen professional female futsal players (mean age: 23.7 ± 5.1 years, age range: 18-28 years) were randomly assigned to a CTS (n = 7) or a CTU (n = 7) group. The intervention program was carried out 3 times a week over 6 weeks. Players of both groups performed the same four core-strengthening exercises. The only difference between the two interventions was that the CTU group performed all exercises (i.e., shoulder bridge, side bridge, prone plank, and crunch) on an unstable surface (Togu® Dyn-Air). Within-group analysis showed significant improvements (p < 0.001) in 10 m sprint performance from the pre- to post-test in the CTS (+4.37%) and CTU (+5.00%) groups. Players in both the CTS (+10.39%) and CTU (+11.10%) group also showed significant enhancement in the Functional Movement Screen total score, from the pre-test to post-test. In addition, a significant time effect was also observed for the CTU group in the relative score of the RSA test decreasing from the pre- to post-test (-30.85%). In the between-groups analysis, there were no significant differences between the core strength training groups (CTS vs CTU) in any variable. To conclude, sprint and Functional Movement Screen performance improved following CTS and CTU when conducted in combination with regular futsal training. In addition, CTU had limited benefit in RSA compared to CTS.

Open access
DNA extraction and amplification from Pinaceae dry wood

Abstract

Wood constitutes the unique source of DNA in dead trees, but extraction of adequate quality DNA from dry wood is usually challenging. However, many different molecular studies require the use of such DNA. We have standardized and validated a modified CTAB protocol to isolate DNA from dry wood from Abies pinsapo and Cedrus atlantica species. Due to the degradation and very little DNA that is normally present in the wood from dead trees we have developed a PCR based test to certify the quality of the extracted samples. In the present study, we have proved too the effectiveness of this methodology to isolate DNA from conifer dry wood samples of sufficient quality to perform further molecular genetic experiments.

Open access
Event–Based Feedforward Control of Linear Systems with input Time–Delay

Abstract

This paper proposes a new method for the analysis of continuous and periodic event-based state-feedback plus static feed-forward controllers that regulate linear time invariant systems with time delays. Measurable disturbances are used in both the control law and triggering condition to provide better disturbance attenuation. Asymptotic stability and L2-gain disturbance rejection problems are addressed by means of Lyapunov–Krasovskii functionals, leading to performance conditions that are expressed in terms of linear matrix inequalities. The proposed controller offers better disturbance rejection and a reduction in the number of transmissions with respect to other robust event-triggered controllers in the literature.

Open access
Effect of hydraulic loading rate and vegetation on phytoremediation with artificial wetlands associated to natural swimming pools

Abstract

The treatment of pool water, whether for recreational or sporting purposes, by phytoremediation is widely applied. This work evaluates two artificial vertical flow wetlands, one on a real scale and the other on a laboratory scale, which have been planted with Typha domingensis, for the treatment of pool water in the climatic conditions of the city of Santiago de Cuba. When the hydraulic load applied to the real scale wetland was less than 0.25 m3∙m–2∙d–1, the levels of organic and microbiological contamination in the pool were below the maximum limits allowed by Cuban standards. At a laboratory scale, the presence of vegetation favoured the elimination of nitrogen compounds (nitrates and ammonium) and organic materials (BOD and COD). This behaviour is explained by the presence of processes of assimilation of organic compounds, or by the action of microorganisms associated with the rhizome of plants, which establish a symbiotic mechanism favourable to phytodepuration. The minimum concentration of ammonium obtained in outflow from the laboratory-scale reactor without vegetation reached a value of 2.15 mg∙m–3, which is within the limits allowed by the sanitary regulations.

Open access