974 research outputs found

    Brown algae as heavy metals and nitrogen biomonitors of coastal areas: a review of protocols

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    Since the 1950s, marine macroalgae have been used as biomonitors of pollution (including heavy metals, organic compounds, or radioactive elements, among others). These organisms have the ability to bioconcentrate bioavailable compounds from the environment, and through a chemical analysis of their tissues, are used as indicators of water quality. However, despite their relevance, there is no standardized protocols for their use as a tool in environmental monitoring programmess. The harmonization of protocols is very important because algae are often included in legislative measurements, and the lack of scientifically based protocols can lead to deficiencies in such regulations. Therefore, an exhaustive study of the use of marine macroalgae in biomonitoring, as well as the standardization of some important methodological aspects of the technique, such as the sampling design, the type of sample, etc., has been carried out in this Doctoral Thesis in order to contribute to the standardization of this technique

    Factorial Analysis of the Skills Preferred by Basketball Players : a Study in Young Players

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    The aim of this work is to classify basketball skills according to the preference of the young players who play this sport. The most interesting results show the existence of 5 factors which could explain the variation percentage of 66, 99 %. The drew factors arranged from better to worse as a function of how well they explain the issue, have been named as " Shot and scores 1 or 2 points "; " Receive + Defence + Bounce "; " Recover + 3 points scores "; " Provoke personal fault " and " Rebound "

    Application of a Token Economy Program and Preferences for Basketball Players

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    The aim of this work is to analyze the differences between players of a group following a token economy program and another who does not follow it. The results indicate that young players perceive that their trainers have a preference for attacking actions during the match; this unanimity in preferences disappears during training. Significant differences were found significant differences in the preferences of coach during training; which means that belonging to one group of study implies different choices. There have been found significant differences between groups in specific skills related to defense and ball reception

    Local genetic structure on breeding grounds of a long-distance migrant passerine: the bluethroat (Luscinia svecica) in Spain

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    Breeding site fidelity can be determined by environmental features, which depending on their heterogeneous distribution may shape the genetic landscape of a population. We used 10 microsatellite loci to study the genetic variation of 83 bluethroats (Luscinia svecica azuricollis) across 14 localities within the Spanish breeding population and assess the relative influence of different habitat characteristics (physiography and vegetation) on genetic differentiation. Based on the genetic variation of this population, we identified 3 geographically consistent genetic clusters that on average showed a higher genetic differentiation than among other north European populations, even those belonging to different subspecies. The inferred genetic clusters occurred in geographic areas that significantly differed in elevation. The highest genetic differentiation was observed between sites at different mountain ranges, as well as between the highest altitude sites in the northeastern locale, whereas vegetation type did not explain a significant percentage of genetic variation. The lack of correlation between geographic and genetic distances suggests that this pattern of genetic structure cannot be explained as a consequence of isolation by distance. Finally, we discuss the importance of preserving areas encompassing high environmental and genetic variation as a means of preserving evolutionary processes and adaptive potential.University of LeĂłn (2009/00131/00); CSIC/MICINN Proyecto Intramural Especial-PIE (201030I019).Peer Reviewe

    Pseudoepitheliomatous hyperplasia after diode laser oral surgery: an experimen tal study

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    Background : To examine the process of epithelial reparation in a surgical wound caused by diode laser. Material and Methods : A n experimental study with 27 Sprage-Dawley rats was undertaken. The animals were randomly allocated to two experimental groups, whose individuals underwent glossectomy by means of a diode laser at different wattages, and a control group treated using a number 15 scalpel blade. The animals were slaughtered at the 2nd, 7th, and 14th day after glossectomy. The specimens were independently studied by two pathologists (blinded for the specimens’ group). Results: At the 7th day, re-epithelisation was slightly faster for the control group (conventional scalpel) ( p =0.011). At the 14th day, complete re-epithelization was observed for all groups. The experimental groups displayed a pseudoepitheliomatous hyperplasia. Conclusions: It is concluded that, considering the limitations of this kind of experimental studies, early re-epithelisation occurs slightly faster when a conventional scalpel is used for incision, although re-epithelisation is completed in two weeks no matter the instrument used. In addition, pseudoepitheliomatous hyperplasia is a potential event after oral mucosa surgery with diode laser. Knowledge about this phenomenon (not previously described) may prevent diagnostic mistakes and inadequate treatment approaches, particularly when dealing with potentially malignant oral lesions

    Philosophical and Epistemological Basis for Building a Quality Online Training Methodology

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    This chapter outlines the problem of laying the groundwork for building a suitable online training methodology. In the first place, it points out that most e-learning initiatives are developed without a defined method or an appropriate strategy. It then critically analyzes the role of the constructivist model in relation to this problem, affirming that this explanatory framework is not a method and describing the problems to which this confusion gives rise. Finally, it proposes a theoretical and epistemological framework of reference for building this methodology based on Greek paideía. The authors propose that the search for a reference model such as the one developed in ancient Greece will allow us to develop a method based on the importance of a teaching profile “different” from traditional academic roles and which we call “tutor.” It has many similarities to the figures in charge of monitoring learning both in Homeric epic and Classical Greece

    Determining Quality for Online Activities. Methodology and Training of Online Tutors as a Challenge for Achieving the Excellence

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    The Information and Communication Technologies have meant a significant evolution in distance education, thus the roles of the student and the teacher have shifted from a traditional teacher-centred standpoint, to a more dynamic perspective, with the student as the central character. Whereas the role of the teacher has been extensively studied, that has not been the case with the online student. This paper reflects on the role of the online learner and draws some conclusions about the key qualities these students need to be successful in any eLearning setting, from the perspective of the Continuing Education and Specialization course Technologies and Methods in Networked Learning: Tutor Online (TOL), held by the University of Salamanca (Spain) from 2004

    Looking for the excellence in eLearning initiatives. Methodology and training of online tutoring

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    The aim of this paper is to analyze the main issues to be considered in order to design a quality framework for eLearning. Among other aspects, the active role of online tutors will be shown as a fundamental activity to achieve excellence in eLearning activities. To know how online tutors really work, the training program to be followed by those who desire to become online tutors will be shown, as so as their methodology, skills and competences
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