349 research outputs found

    El uso del ordenador como instrumento para enseñar a manejar sistemas de adquisición de datos experimentales

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    En este trabajo vamos a presentar el estado de desarrollo de un proyecto de innovación educativa destinado a favorecer el uso de las Tecnologías de la Información y la Comunicación (TIC) en la formación científica y técnica de los estudiantes de Ingeniería. En concreto este proyecto se ha centrado en la elaboración y aplicación de un software educativo que permita a nuestros alumnos aprender a manejar un sistema de adquisición de datos (SAD) que después será utilizado como instrumento de medida de variables físicas en diversos procesos experimentales. Tras elaborar un primer prototipo del programa hemos comenzado a utilizar esta aplicación como instrumento de enseñanza virtual, en una fase previa al uso real del citado sistema de adquisición de datos por parte de los alumnos, en el desarrollo de experiencias de laboratorio. En este proceso hemos observado que el software elaborado contribuye a que los estudiantes comiencen a familiarizarse con la metodología experimental y el instrumental, antes de pasar a utilizarlo en la realización de experiencias reales

    Estudio didáctico interactivo de los estados de la materia EDIEMA

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    La falta de recursos tales como laboratorios y materiales así como la peligrosidad de algunas prácticas, hacen que la enseñanza de la Química sea muy teórica, cuando es una ciencia básicamente experimental. Por otra parte, la tendencia, en la docencia Universitaria, está cambiando desde el concepto de enseñanza del profesor al aprendizaje del alumno, es decir, el alumno ha de ser artífice de su propio aprendizaje, actuando de forma activa en al adquisición de conocimientos y habilidades. La aplicación desarrollada: estudio didáctico interactivo de los estados de la materia (EDIEMA), pretende paliar el déficit de recursos y ayudar al alumno en su autoaprendizaje, mediante un sistema tutorizado, ya que permite mostrar, con detalle, las propiedades físicas de los tres estados de la materia, gases, líquidos y sólidos, desde un punto de vista molecular, sin necesidad de disponer de laboratorios, material, etc. Este estudio se realiza mediante simulaciones en tres dimensiones de experimentos y propiedades relacionadas con los gases, líquidos y sólidos, centrándose principalmente en el estado gaseoso, ya que es el más difícil de experimentar en un laboratorio. El software consta de tres partes: tutorial, simulación y ejercicios. En el tutorial se exponen los contenidos teóricos, en la simulación se presentan las experiencias de laboratorio que dieron lugar a la formulación de leyes. En el apartado de ejercicios se formulan cuestiones para la autoevaluación del conocimiento adquirid

    Estudio de campos electromagnéticos medioambientales: una propuesta que conecta asignaturas científicas con aspectos tecnológicos, sociales y medioambientales

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    In order to make the student to be interested on what he has to study, we have developed a new educational tool called "Study of environmental electromagnetic fields: a proposal that connects scientific subject to technologic, social and environmental issues". It is presented as an introduction to the measurement of electomagnetic fields, it means, to what nowadays is called electromagnetic pollution. In that way it tries to relate scientific subject to technologic, social and environmental issues that are important for the present society. Our aim is to remove the isolation between education in universities and the students' surroundings.Con el afán de motivar a nuestros alumnos de ingeniería, hemos desarrollado una nueva herramienta docente que denominamos "Estudio de campos electromagnéticos medioambientales: una propuesta que conecte asignaturas científicas con aspectos tecnológicos, sociales y ambientales". Con ella pretendemos introducir al alumno en la medición de campos electromagnéticos, esto es, en lo que actualmente se conoce como medición de contaminación alectromagnética.De esta forma, se trata de una propuesta que conecta asignaturas científicas con aspectos tecnológicos, sociales y ambientales de actualidad. Con ello queremos romper el aislamiento que existe en muchas ocasiones entre la enseñanza universitaria y la realidad que conoce y rodea al alumno

    Co-ingestion of carbohydrate with branched-chain amino acids or L-leucine does not preferentially increase serum IGF-1 and expression of myogenic-related genes in response to a single bout of resistance exercise

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    This study determined if the co-ingestion of carbohydrate (CHO) with branched-chain amino acids (BCAA) or L-leucine (LEU) preferentially affected serum IGF-1 and the expression of myogenic-related genes in response to resistance exercise (RE). Forty one, college-age males were randomly assigned to 1 of 4 groups: CHO, CHO-BCAA, CHO-LEU, or placebo (PLC). Resistance exercise consisted of 4 sets of leg press and leg extension at 80% 1RM. Supplements were ingested peri-exercise, and venous blood and muscle biopsies were obtained pre-exercise (PRE), and at 30, 120, and 360 min post-exercise. Serum IGF-1 was determined with ELISA, and skeletal muscle mRNA expression of myostatin, ActRIIB, p21kip, p27kip, CDK2, cyclin B1, cyclin D1, Myo-D, myogenin, MRF-4, and myf5 was determined using real-time PCR. Results were determined with two-way ANOVA for serum IGF-1 and two-way MANOVA for mRNA expression. Serum IGF-1 in CHO and CHO+BCAA was greater than PLC (p \u3c 0.05) but was not affected by RE (p \u3e 0.05). Significant differences were detected between groups for myostatin, ActIIB, MyoD, and myf5 mRNA expression showing CHO to be significantly different than CHO+BCAA, CHO+LEU, and PLC (p \u3c 0.05). At 30, 120 and 360 min post-exercise, p21cip was significantly less than PRE, whereas cyclin D1 was greater than PRE at 120 and 360 min post-exercise (p \u3c 0.05). The co-ingestion of CHO with either BCAA or L-leucine in conjunction with RE had no preferential effect on serum IGF-1 or pre-translational markers indicative of myogenesis

    A salting out and resin procedure for extracting Schistosoma mansoni DNA from human urine samples

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    Submitted by Nuzia Santos ([email protected]) on 2012-09-27T14:31:36Z No. of bitstreams: 1 36.2010.pdf: 789056 bytes, checksum: 0a4282ac34d4c6aef08223da45e0f126 (MD5)Made available in DSpace on 2012-09-27T14:31:36Z (GMT). No. of bitstreams: 1 36.2010.pdf: 789056 bytes, checksum: 0a4282ac34d4c6aef08223da45e0f126 (MD5) Previous issue date: 2010Fundação Oswaldo Cruz. Laboratório de Esquistossomose. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, Brasil/ Universidade Federal de Ouro Preto. Escola de Farmácia. Laboratório de Pesquisas Clínicas. Ouro Preto, MG, BraziBackground: In this paper a simple and cheap salting out and resin (InstaGene matrix® resin - BioRad) DNA extraction method from urine for PCR assays is introduced. The DNA of the fluke Schistosoma mansoni was chosen as the target since schistosomiasis lacks a suitable diagnostic tool which is sensitive enough to detect low worm burden. It is well known that the PCR technique provides high sensitivity and specificity in detecting parasite DNA. Therefore it is of paramount importance to take advantage of its excellent performance by providing a simple to handle and reliable DNA extraction procedure, which permits the diagnosis of the disease in easily obtainable urine samples. Findings: The description of the extraction procedure is given. This extraction procedure was tested for reproducibility and efficiency in artificially contaminated human urine samples. The reproducibility reached 100%, showing positive results in 5 assay repetitions of 5 tested samples each containing 20 ng DNA/5 ml. The efficiency of the extraction procedure was also evaluated in a serial dilution of the original 20 ng DNA/5 ml sample. Detectable DNA was extracted when it was at a concentration of 1.28 pg DNA/mL, revealing the high efficiency of this procedure. Conclusions: This methodology represents a promising tool for schistosomiasis diagnosis utilizing a bio-molecular technique in urine samples which is now ready to be tested under field conditions and may be applicable to the diagnosis of other parasitic disease

    Statin use and the risk of colorectal cancer in a population-based electronic health records study

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    There is extensive debate regarding the protective effect of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) on colorectal cancer (CRC). We aimed to assess the association between CRC risk and exposure to statins using a large cohort with prescription data. We carried out a case-control study in Catalonia using the System for Development of Primary Care Research (SIDIAP) database that recorded patient diseases history and linked data on reimbursed medication. The study included 25 811 cases with an incident diagnosis of CRC between 2010 and 2015 and 129 117 frequency-matched controls. Subjects were classified as exposed to statins if they had ever been dispensed statins. Analysis considering mean daily defined dose, cumulative duration and type of statin were performed. Overall, 66 372 subjects (43%) were exposed to statins. There was no significant decrease of CRC risk associated to any statin exposure (OR = 0.98; 95% CI: 0.95-1.01). Only in the stratified analysis by location a reduction of risk for rectal cancer was observed associated to statin exposure (OR = 0.87; 95% CI: 0.81-0.92). This study does not support an overall protective effect of statins in CRC, but a protective association with rectal cancer merits further research

    Development and Evaluation of a Sensitive PCR-ELISA System for Detection of Schistosoma Infection in Feces

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    Schistosomiasis is a neglected disease caused by worms of the genus Schistosoma. The transmission cycle requires contamination of bodies of water by parasite eggs present in excreta, specific snails as intermediate hosts and human contact with water. Fortunately, relatively safe and easily administrable drugs are available and, as the outcome of repeated treatment, a reduction of severe clinical forms and a decrease in the number of infected persons has been reported in endemic areas. The routine method for diagnosis is the microscopic examination but it fails when there are few eggs in the feces, as usually occurs in treated but noncured persons or in areas with low levels of transmission. This study reports the development of the PCR-ELISA system for the detection of Schistosoma DNA in human feces as an alternative approach to diagnose light infections. The system permits the enzymatic amplification of a specific region of the DNA from minute amounts of parasite material. Using the proposed PCR-ELISA approach for the diagnosis of a population in an endemic area in Brazil, 30% were found to be infected, as compared with the 18% found by microscopic fecal examination. Although the technique requires a complex laboratory infrastructure and specific funding it may be used by control programs targeting the elimination of schistosomiasis

    Statin use and the risk of colorectal cancer in a population-based electronic health records study

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    There is extensive debate regarding the protective effect of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) on colorectal cancer (CRC). We aimed to assess the association between CRC risk and exposure to statins using a large cohort with prescription data. We carried out a case-control study in Catalonia using the System for Development of Primary Care Research (SIDIAP) database that recorded patient diseases history and linked data on reimbursed medication. The study included 25 811 cases with an incident diagnosis of CRC between 2010 and 2015 and 129 117 frequency-matched controls. Subjects were classified as exposed to statins if they had ever been dispensed statins. Analysis considering mean daily defined dose, cumulative duration and type of statin were performed. Overall, 66 372 subjects (43%) were exposed to statins. There was no significant decrease of CRC risk associated to any statin exposure (OR = 0.98; 95% CI: 0.95-1.01). Only in the stratified analysis by location a reduction of risk for rectal cancer was observed associated to statin exposure (OR = 0.87; 95% CI: 0.81-0.92). This study does not support an overall protective effect of statins in CRC, but a protective association with rectal cancer merits further research

    Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin

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    Background: In inland water systems, it is important to characterize the trophic links in order to identify the ‘trophic species’ and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours. Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs. Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro- and microfauna.Fil: Williner, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; ArgentinaFil: de Azevedo Carvalho, Debora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Collins, Pablo Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentin
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