1,032 research outputs found
Cálculo de índices de confort térmico en recintos cerrados con transferencia de calor
El trabajo que se presenta forma parte de los estudios que el grupo de investigación "Análisis Térmico y Ventilación en la Ingeniería y la Edificación" está desarrollando para la realización del Proyecto "Estudio de la eficiencia energética y del confort en un edificio bioclimático" en la Universidad Politécnica de Madrid. El objetivo general de dicho proyecto es aportar, a través de modelos físicos y datos experimentales, información relevante que sirva para optimizar el consumo energético de una vivienda bioclimática en la Comunidad de Madrid.
Con este fin, en el presente trabajo se simula el comportamiento del aire en una habitación, mediante un modelo CFD (Computational Fluid Dynamics), con el fin de determinar los índices deconfort térmico en el recinto, bajo dos supuestos de calefacción utilizados en edificación: radiadores y suelo radiante
De la Diplomatura al Grado en Logopedia: influencia sobre las tasas de éxito y rendimiento en una asignatura obligatoria
[Resumen] El proceso de convergencia hacia el Espacio Europeo de Educación Superior (EEES) es hoy
día un hecho, y lleva en funcionamiento tiempo suficiente para permitir la realización de
comparaciones. Como consecuencia de su implantación, se ha producido un potente
movimiento innovador en la concepción del sistema educativo universitario dentro de la Unión
Europea, dando respuesta al reto planteado acerca de alcanzar el equilibrio entre la formación
creativa orientada al mercado laboral, la especialización y la formación de futuros
investigadores. Una de las modificaciones más evidentes ha sido la distribución de las clases
presenciales en dos tipos: expositivas (dirigidas al conjunto del grupo, las tradicionales
lecciones magistrales) e interactivas (dirigidas a subgrupos de estudiantes, que se concreta en
actividades tipo seminarios, debates y prácticas), acompañada de cambios simultáneos en las
metodologías docentes y técnicas de evaluación. Con el objetivo de evaluar los resultados de
la adaptación de estudiantes y docentes al EEES, en este trabajo se recoge el análisis
comparativo de la evolución de los resultados académicos en la asignatura “Alteraciones
congénitas del lenguaje”, de la Diplomatura en Logopedia, posteriormente transformada a
“Alteraciones de base congénita” en el Grado en Logopedia, en una franja temporal desde 3
años antes hasta 6 años después de la transformación. Es una materia de segundo curso en el
Grado, obligatoria y con una carga docente de 6 ECTS. Asimismo, se han determinado los
efectos sobre las tasas de éxito, rendimiento y evaluación. El número de estudiantes
matriculados en los últimos años de la Diplomatura fue notablemente bajo. Los resultados
reflejan que el proceso de adaptación tuvo consecuencias inicialmente negativas sobre las
calificaciones, aunque fueron mitigándose con el tiempo, hasta alcanzar en la actualidad
niveles incluso mejores que los anteriores a la adaptación. Mientras que las tasas de éxito y
rendimiento de los primeros cursos del Grado se vieron significativamente reducidas, la tasa
de evaluación mantuvo valores estables durante el periodo analizad
Development and Screening of a Marker to Detect Activated Rainbow Trout Leukocytes
Monoclonal antibodies (mAbs) have been essential tools in the elucidation of the immune system of mammals, and their application to identify surface molecules on leukocytes have allowed important functions of these cell to be identified (such as receptors that bind antigens, ligands involved in cell to cell signaling or in initiating immune response activity). Not only have mAbs been used to discriminate cells during different stages of cell development, but have also assisted in understanding the dynamics of molecules expressed during functional processes. Such molecules detected on human leukocytes are called human leukocyte differentiation antigens or HLDA. In order to group the antibodies that detect similar molecules and have similar patterns of reaction, immunologists have organised the mAbs that bind to these antigens into Clusters of Differentiation (CD). So far, there are about 350 leukocyte surface molecules detected by mAbs with a CD nomenclature for human leukocytes (www.hcdm.org).
In fish immunology there is a great need to produce mAbs that are able to differentiate the various components of the fish immune system to assist in the elucidation of the fish immune system. The present study was an endeavour to develop and characterise mAbs that could be accredited to such scheme. A better understanding of the fish immune system is urgently required so that effective strategies of control can be developed for significant diseases during fish farming.
Monoclonal antibodies were prepared by immunizing mice with thymic leukocytes from rainbow trout. The leukocytes were activated with the lectin Concanavalin A to promote the activation and proliferation of the target T-cell population. The selection of clones producing antibodies during screening was performed on the basis of the response of the supernatant from hybridomas using three consecutive assays. First, selection was determined by the positive staining of cells from the thymus in a Dot blot assay. Secondary screening was performed by means of flow cytometry (FCM) and the criterion for selection was the preferential detection of leukocytes gated in the lymphocyte region. Finally, the positive supernatants from hybridomes were evaluated to determine their effectiveness in the detection of modifications in the labelled cells during a multiple way activation by detection of foreign histocompatibility complex enhanced with mitogens.
Monoclonal antibody TcOm15 was selected from 564 hybridomas produced and then used to stain cells from various Rainbow Trout tissues. It was clear from FCM, microscopy and Western blot analysis that mAb TcOm15 not only reacted with thymic cells but also with cells from other tissues. Differential staining of cells with mAb TcOm15 was observed with 27.1 ±1.4 % of leukocytes from peripheral blood leukocytes (PBL) stained in comparison to 2.0 ±0.2 % from the thymus, 13.8 ±0.4 % from the spleen, and 5.6 ±0.6 % cells stained from head kidney. The labeled cells showed characteristics of lymphocytes and monocytes, presenting a distinctive staining in immunohistochemistry and confocal microscopy.
Western blot analysis, using electrophoresed proteins under denaturing conditions with leukocytes from several different tissues, showed that mAb TcOm15 did not detect a single protein. At least three proteins appeared to be identified by the mAb at 105, 160 and 200 kDa. The proteins were identified as α Actinin-4, non-erythroid Spectrin αII chain or Ig-like protein and non-muscle Myosin (MYH10) by MALDI-TOF analysis. Three of these identities are for compositional molecules for the cytoskeleton of different types of cells, and one it is associated to immunoglobulin superfamily. The identification of these proteins by mAb TcOm15 suggests an ability of this mAb to detect a specific function, possibly related with the synchronicity of expression or interaction of cytoskeleton-membrane proteins forming a multiprotein complex. Another possibility is as a carrier role for a protein during interactions.
Colocalization of the mAb with F actin from the cytoskeleton was also observed suggesting the possibility that mAb TcOm15 detects a specific site in a multi-protein complex from the cytoskeleton. The molecule detected showed down-regulation in a dose dependant way with Concanavalin A and the expression was almost lost following stimulation of cells with phorbol 12-myristate 13-acetate stimulation. Leukocytes from the PBL and thymus up-regulated the expression of the TcOm15 molecule under mitogenic conditions in vitro, and results from in vivo experiments suggested the possibility of up-regulation on thymic cells.
In conclusion, the results obtained in the present study provide information on a potentially useful marker (mAb TcOm15) for a cytoskeleton-membrane antigen that is modulated during stimulation of teleost lymphocytes. Additionally, this may enable insights into the relationship between cytoskeletal proteins and membrane associated immunoglobulin. Future research is necessary in order to explain this relationship and to determine the functional participation of the TcOm15 molecule during the activation of rainbow trout cells
The Organic Selenium Compound Selenomethionine Modulates Bleomycin-Induced DNA Damage and Repair in Human Leukocytes
This is an Accepted Version of the published document. This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s12011-009-8407-9[Abstract] The objective of this work was to evaluate the effects of selenomethionine (SeMet) on the induction, repair, and persistence of DNA damage in human leukocytes challenged with bleomycin (BLM). Comet assay was used to determine DNA strand breaks and hOGG1 for the specific recognition of oxidative damage. Leukocytes were (A) stimulated with phytohemagglutinin, (B) damaged with BLM, and (C) incubated to allow DNA repair. Comet assay was performed after each phase. SeMet (50 μM) was supplemented either during phase A, B, or C, or AB, or ABC. Treatment with SeMet decreased BLM-induced stand breaks when added during phase AB. Results obtained after the repair period indicate that SeMet favors repair of DNA damage especially when applied during phase AB. The comparison between DNA damage before and after repair showed that BLM-induced damage was repaired better in the presence of SeMet. Our results showed antigenotoxic effect of SeMet on BLM-induced DNA and also on repair and persistence of this damage when applied before and simultaneously with BLM.This work was funded by a grant from the Xunta de Galicia (INCITE08PXIB106155PR). V. Valdiglesias was supported by a fellowship from the University of A CoruñaGalicia. Xunta; INCITE08PXIB106155P
MECANyONDAS -09
El planímetro es un aparato diseñado para realizar medidas directas de superficies con artilugios mecánicos. Se emplea para medir figuras geométricas, irregulares, mapas geográficos, etc. para lo cual basta seguir su contorno con una punta situada en el extremo de un brazo articulado unido a un conjunto de ingeniosos dispositivos mecánicos articulados. Es de señalar que el planímetro inspiró la invención del ratón que todos usamos en nuestro ordenador, tanto es así que el primer prototipo de ratón se construyó a partir de la tecnología del planímetro. Tamaño caja (alto x largo x ancho): 5.3x25.7x9.7 cm Tamaño instrumento (alto x largo x ancho): 22.5x4.5x2 cmCuando necesitamos medir la superficie de una figura plana sencilla o facilmente descomponible en figuras sencillas, el problema no reviste mayor complejidad. Considérese por ejemplo el caso de una figura que podemos descomponer en un conjunto de triángulos rectángulos; si el número de triángulos no es excesivo el problema es trivial. Si por el contrario la figura es más compleja el trabajo se hace muy tedioso y además un elevado número de triángulos supondrá un error creciente acumulado en el resultado final. El trabajo era tan enorme que algunas veces se recurría a medir el área de la figura recortándola y comparando su peso con el de una figura regular simple realizada en el mismo material, utilizando una simple balanza convencional. Para evitar esos cálculos, a finales del siglo XIX, se diseñaron los primeros planímetros que podemos definir como aparatos para medir por procedimientos puramente mecánicos la superficie de una figura irregular, siendo suficiente recorrer su contorno con una punta colocada en el extremo de uno de los brazos del aparato, el brazo trazador. En un planímetro polar, el polo o extremo del otro brazo, el polar, se fija en un punto determinado y cuando el trazador se mueve a lo largo de la curva frontera de la región, una rueda contadora sobre este brazo se desliza parcialmente y rueda también parcialmente en forma perpendicular al brazo trazador. El planímetro mide la distancia que la rueda gira y se demuestra que ésta es proporcional al área encerrada por el contorno recorrido. La teoría que subyace en el funcionamiento del planímetro y que demuestra lo que se acaba de indicar está relacionada con el teorema de Green de forma que a veces se refiere esta propiedad como teorema del planímetro. El primer planímetro fue desarrollado por el suizo Jakob Amsler-Laffon en 1854
Cytogenetic Effects Induced by Prestige Oil on Human Populations: The Role of Polymorphisms in Genes Involved in Metabolism and DNA Repair
This is a manuscript version of the article.[Abstract] The spill from the oil tanker Prestige (NW Spain, November 2002) was perhaps the biggest ecological disaster that happened worldwide in the last decades. As a consequence of this catastrophe a general concern led to a huge mobilization of human and technical resources. Given that no information was reported in the scientific literature regarding to the chronic repercussions to human health of exposure to oil spills, a pilot study was performed by our group revealing some increased genotoxic effects in the subjects exposed to the oil during cleaning activities. Due to the seriousness of the results, we extended our study comprising a larger population and including an extensive evaluation of the main polymorphic sites in metabolizing and DNA-repair genes. General increases in micronucleus (MN) frequency and decreases in the proliferation index were observed in individuals with longer time of exposure. Age was a significant predictor of MN frequency. CYP1A1 3′-UTR, EPHX1 codons 113 and 139, GSTP1, GSTM1 and GSTT1 metabolic polymorphisms, and XRCC3 codon 241 and XPD codon 751 repair polymorphisms influenced cytogenetic damage levels. In view of these results, it seems essential to pay more attention to the chronic human health effects of exposure to oil and to focus new studies on such a relevant but overlooked public health field that involves a large number of people all over the world.This work was partially funded by a grant from the Fundación Arao through the intervention of Dr. Juan Jesús Gestal and Dr. Ernesto Smyth, and by the University of A Coruña. B. Pérez-Cadahía and V. Valdiglesias were supported by fellowships from the University of A Coruña
Identification of differentially expressed genes in SHSY5Y cells exposed to okadaic acid by suppression subtractive hybridization
<p>Abstract</p> <p>Background</p> <p>Okadaic acid (OA), a toxin produced by several dinoflagellate species is responsible for frequent food poisonings associated to shellfish consumption. Although several studies have documented the OA effects on different processes such as cell transformation, apoptosis, DNA repair or embryogenesis, the molecular mechanistic basis for these and other effects is not completely understood and the number of controversial data on OA is increasing in the literature.</p> <p>Results</p> <p>In this study, we used suppression subtractive hybridization in SHSY5Y cells to identify genes that are differentially expressed after OA exposure for different times (3, 24 and 48 h). A total of 247 subtracted clones which shared high homology with known genes were isolated. Among these, 5 specific genes associated with cytoskeleton and neurotransmission processes (NEFM, TUBB, SEPT7, SYT4 and NPY) were selected to confirm their expression levels by real-time PCR. Significant down-regulation of these genes was obtained at the short term (3 and 24 h OA exposure), excepting for NEFM, but their expression was similar to the controls at 48 h.</p> <p>Conclusions</p> <p>From all the obtained genes, 114 genes were up-regulated and 133 were down-regulated. Based on the NCBI GenBank and Gene Ontology databases, most of these genes are involved in relevant cell functions such as metabolism, transport, translation, signal transduction and cell cycle. After quantitative PCR analysis, the observed underexpression of the selected genes could underlie the previously reported OA-induced cytoskeleton disruption, neurotransmission alterations and <it>in vivo </it>neurotoxic effects. The basal expression levels obtained at 48 h suggested that surviving cells were able to recover from OA-caused gene expression alterations.</p
- …