1,100 research outputs found

    The enzymatic determination of glucose in carbonated beverages: a useful tool for the undergraduate students to learn the basis of enzymatic analysis and the comparison of two analytical methods

    Get PDF
    The importance of enzymatic analysis in biochemistry, clinical chemistry and food chemistry is undoubted. The course "Applied Biochemistry" in our Faculty is aimed to undergraduate students of Chemistry and Biochemistry. In this subject, the principles and applications of enzymatic analysis are presented to the students, who receive a theoretical introductory lecture in the classroom before they carry out an experiment that should be feasible to be solved in a short laboratory period. The experimental protocol here presented, based on the enzymatic determination of glucose in carbonated beverages, has been implemented at the University of Málaga and it has been optimized according to the students’ results and commentaries along the last years. It aims to illustrate basic issues relating enzymatic analysis, including its potential application to food chemistry. Although there are several enzymatic methods that can be used for the determination of glucose, we selected the one based on the coupled reactions of glucose oxidase (GOD; EC 1.1.3.4.) and peroxidase (POD; EC 1.11.1.7.) because the kinetic constants of glucose oxidase allow the mentioned enzymatic reactions to be used in both, the end point and the kinetic enzymatic analysis methods. In this way, data for two different protocols for the determination of glucose concentration are obtained by the students from a single reaction mixture. Students construct a calibration curve for each method using a glucose standard solution, and use them to determine the glucose concentration in the problem solutions. The inclusion of replicate samples in the determination of the glucose concentration of an “ideal problem” (glucose in purified water) is used to illustrate the principles of statistics in the lab, and comparison with the “real value” allows an estimation of the accuracy of each method. The evaluation of glucose concentration in four carbonated beverages: coloured coke and uncoloured tonic sodas (regular or sugarless in both cases) makes student to recognise the appearance of interferences that should be either avoided or eliminated. Since all samples are analysed by means of end-point and kinetic methods, students can discuss the applicability of each method to these specific analytical problems. They are also encouraged to compare both analytical methods in terms of sensitivity, selectivity, accuracy, and time consumed. Chemistry and Biochemistry undergraduate students having performed this experiment in our laboratories have found it formative, interesting and challenging.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    A practice project to prevent the cookbook model as modus operandi for biochemistry laboratory learning

    Get PDF
    Laboratory learning is a crucial component of chemistry and biochemistry instruction and should be conceived as a way to develop students’ reasoning, technical or practical skills, introducing them into the scientific method principles. Nevertheless, the heavily criticized “expository instruction style”, characterized by a cookbook nature, is still the most widespread style of laboratory instruction in our universities. Alternative learning styles based in the inquiry, discovery and problem-based pedagogical approaches, have been reported to promote students’ problem solving skills, critical thought and self-confidence development. We are currently involved in the Educative Innovation Project PIE17-065, funded by University of Malaga, aimed to improve the teaching practice of Biochemistry laboratory to undergraduate students. Based on an enzymatic analysis of glucose in soft-drinks we have developed a laboratory protocol as a part of a full practice project where students must work before and after the lab session, in order to prevent the cookbook model as modus operandi, therefore preventing the situation where the students get a first glimpse of the experiment protocol whereas they put on their lab coat. The learning activities have been designed to move our students from the passive role that characterizes the step-by-step procedures, to an active and critical attitude that starts before and remains after their laboratory session, also minimizing time, space, and equipment resources. Our results have shown that this experiment has improved the learning of both, future biochemists and chemists, which showed a very positive perception of the whole practical project.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. PIE 17-06

    Biotechnological potential of microorganisms isolated from the salar del hombre muerto, Argentina

    Get PDF
    Bacterial strains were isolated from soil and aqueous solution samples from the Salar del Hombre Muerto, Argentina. A total of 141 strains were characterized and the tolerance to sodium chloride was evaluated. We performed a screening to search for molecules of biotechnological interest: carotenoids (11%), emulsifiers (95%), and exopolysaccharides (6%), and to assess the production of enzymes, including proteolytic (39%), lipolytic (26%), hemolytic (50%), and catalase activities (99%); 25 bacterial strains were selected for further studies. Some of them produced biofilms, but only Bacillus sp. HA120b showed that ability in all the conditions assayed. Although 21 strains were able to form emulsions, the emulsifying index Kocuria sp. M9 and Bacillus sp. V3a cultures were greater than 50% and, emulsions were more stable when the bacteria grew in higher salt concentrations. Only pigmented Kocuria sp. M9 showed lipolytic activity on olive oil medium and was able to produce biofilms when cultured without and with 4 M of NaCl. Yellow pigments, lipase activity, and biosurfactant production were observed for Micrococcus sp. SX120. Summarizing, we found that the selected bacteria produced highly interesting molecules with diverse industrial applications and, many of them are functional in the presence of high salt concentrations.Fil: Lopez, Marta Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Martínez, Fabiana Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Rajal, Verónica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Irazusta, Verónica Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentin

    Learning contract, co-operative and flipped learning as useful tools for studying metabolism

    Get PDF
    Es el Abstract de una comunicación a un congreso internacional sobre educaciónUndergraduate students in Biology identify Metabolic Biochemistry as a particularly difficult subject. This is due to the fact that students need to interconnect properly all the contents of its syllabus throughout their study of the subject in order to get a global insight of the complex regulatory features controlling metabolic pathways within the metabolic network under different physiologic and pathologic conditions, as well as metabolism as a whole. Due to these objective difficulties, a high percentage of our students face the study of this subject as a very hard task beyond their forces and capacities. This perception leads to high rates of premature dropout. In previous years, less than 40% of all the registered students attended the examinations of Metabolic Biochemistry (a subject in the second year of the Degree of Biology at our University). Even worse, less than 25% of our students passed the exams. From the academic year 2015/16 on, we are developing innovative teaching projects (PIE15-163 and PIE17-145, funded by University of Malaga) aimed to increase our student loyalty to the subject (and hence to increase their attendance to exams) and to help them to learn more effectively metabolism and its regulation. These innovative teaching projects are based on the use of several powerful tools: a learning contract and problem-based learning within the framework of group tasks promoting an actual collaborative learning in a flipped classroom. The present communication will show the implementation of the PIE15-163 and PIE17-145 projects and some results obtained from them.This work was supported by Malaga University funds granted to the educational innovation project PIE17-145. The attendance to the END2018 International Conference on Education and New Developments (June 2018, Budapest, Hungary) has received a grant from "I Plan Propio Integral de Docencia. Universidad de Málaga"]

    Towards an unsupervised speaking style voice building framework: multi-style speaker diarization

    Get PDF
    Current text-to-speech systems are developed using studio-recorded speech in a neutral style or based on acted emotions. However, the proliferation of media sharing sites would allow developing a new generation of speech-based systems which could cope with spontaneous and styled speech. This paper proposes an architecture to deal with realistic recordings and carries out some experiments on unsupervised speaker diarization. In order to maximize the speaker purity of the clusters while keeping a high speaker coverage, the paper evaluates the F-measure of a diarization module, achieving high scores (>85%) especially when the clusters are longer than 30 seconds, even for the more spontaneous and expressive styles (such as talk shows or sports)

    Medida de glucosa en refrescos: una útil herramienta para ilustrar el aprendizaje de los fundamentos del análisis enzimático

    Get PDF
    Es indudable la relevancia que el análisis enzimático tiene en el ámbito de la Bioquímica, la Química Clínica y la Química de la Alimentación, entre otras. En la asignatura “Bioquímica Aplicada” de cuarto curso del grado en Química de nuestra Universidad, los alumnos aprenden los fundamentos teóricos del análisis enzimático, que luego ponen en práctica en el laboratorio, en un contexto cotidiano, mediante la determinación de glucosa en diferentes refrescos carbonatados. Aunque existen diversos métodos enzimáticos para la valoración de la concentración de glucosa, hemos elegido para la sesión práctica el que se basa en las reacciones acopladas de la glucosa oxidasa (EC 1.1.3.4.) y la peroxidasa (EC 1.11.1.7.) por ser especialmente ilustrativo a la hora de afianzar los conceptos teóricos desarrollados en clase, así como para despertar su espíritu crítico al enfrentarles a la resolución de problemas “del mundo real” y hacerles elegir qué método analítico puede ser mejor para un caso concreto. Los alumnos usan dos protocolos distintos (métodos cinético y a punto final) para determinar la concentración de glucosa, inicialmente en una muestra de glucosa en agua, familiarizándose con ambos métodos y permitiéndoles construir las rectas de calibrado, mediante las que deberán establecer el rango de aplicación para cada método. La medida de las variaciones de absorbancia con el tiempo, que en el método cinético son proporcionales a la concentración de glucosa, permite ilustrar aspectos metodológicos de la estimación de la velocidad inicial de una reacción enzimática. Posteriormente los alumnos se enfrentan al problema de la medida de la concentración de glucosa en una serie de bebidas que incluyen refrescos de cola y tónicas, con o sin azúcar (refrescos “cero”), encontrándose con nuevas dificultades como son la necesidad de diluir en varios órdenes de magnitud las muestras (lo que les familiariza con el uso de las diluciones seriadas), y la aparición de interferencias debidas al color de la muestra, decantándose por uno u otro método en función de la naturaleza del problema analítico planteado.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Source Language Categorization for improving a Speech into Sign Language Translation System

    Get PDF
    This paper describes a categorization module for improving the performance of a Spanish into Spanish Sign Language (LSE) translation system. This categorization module replaces Spanish words with associated tags. When implementing this module, several alternatives for dealing with non-relevant words have been studied. Non-relevant words are Spanish words not relevant in the translation process. The categorization module has been incorporated into a phrase-based system and a Statistical Finite State Transducer (SFST). The evaluation results reveal that the BLEU has increased from 69.11% to 78.79% for the phrase-based system and from 69.84% to 75.59% for the SFST

    A problem-/case-based learning approach as an useful tool for studying glycogen metabolism and its regulation

    Get PDF
    Versión preprint del manuscrito de los autores, publicado finalmente en: Biochemistry and Molecular Biology Education, con DOI: 10.1002/bmb.21449Metabolism and its regulation is one of the most complex and difficult topics for students learning biochemistry. A problem-/case-based learning (PBL) approach can be useful to help biochemistry students to fulfill the goal of acquiring an integrated view of metabolism and its regulation. The present article describes our experience enrolling volunteer students to learn glycogen metabolism making use of a design-based research methodology to develop teaching learning sequences focused on a PBL approach. Enrolled undergraduate students had better final scores than those students that did not participates. Furthermore, enrolled students were satisfied with the experience, finding it interesting, formative, and challenging.This work was supported by the University of Málaga (Spain) with funds granted to the educational innovation projects PIE15-163, PIE17-145, and PIE19-057. The experimental work carried out by our group is supported by grants PID2019-105010RB-I00 and EDU2017-82197-P (Spanish Ministry of Science, Innovation and Universities), UMA18-FEDERJA-220 (Andalusian Government and FEDER) and funds from group BIO 267 (Andalusian Government), as well as funds from “Plan Propio de Investigación y Transferencia” (U. Málaga)

    Abuse of the elderly

    Get PDF
    El maltrato a personas mayores es una realidad que todavía hoy sigue existiendo a pesar de haberse incluido en las preocupaciones profesionales, políticas y sociales de nuestra sociedad actual. El maltrato al anciano viene definido por patrones culturales según la comunidad de referencia, el momento histórico y el entorno sociocultural que los rodea. Además suele tener lugar tanto en el ámbito social-comunitario, institucional y familiar. En este trabajo nos vamos a centrar en definir los diferentes conceptos relacionados con el maltrato al anciano, las diferentes formas del mismo y sus factores de riesgo, y como detectarlo.Elder abuse is a reality that still exists today despite having been included in the professional, political and social concerns of our current society. Elder abuse is defined by cultural patterns according to the community of reference, the historical moment and the sociocultural environment that surrounds them. In addition, it usually takes place in the social-community, institutional and family spheres. In this paper we will focus on defining the different concepts related to elder abuse, the different forms of the same and their risk factors, and how to detect it

    Relación entre apoyo social percibido y disposición resiliente en adolescentes paraguayos = Relation between perceived social support and resilient disposition in Paraguayan adolescents

    Get PDF
    El estudio de la adolescencia ha destacado la vulnerabilidad del proceso asociado con variables como la disposición resiliente, presente en aquellos recursos que pueden hacer la diferencia para el sustento del bienestar o su ausencia. De estos recursos se destaca el apoyo social que el adolescente percibe de su entorno. El objetivo de la investigación se centró en establecer la relación entre el apoyo social percibido y la disposición resiliente, y compararlas conforme el sexo y la edad de una muestra de adolescentes paraguayos escolarizados.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI
    corecore