1000 resultados para Lois López, Maria
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After most of the native ant species are displaced by the Argentine ant invasion, it is probable that some ecological processes carried out by natives are not replaced. In some cases this could be due to a morphological difference between the Argentine ant and the displaced native ants. The significant decrease in ant richness after the invasion (only two species detected in the invaded zones vs. 25 species in surrounding non-invaded zones) implies a drastic reduction in the ant mandible gap range (the mandible gap spectra of all the ant species in a community) in the invaded zones. This reduction could explain why some roles that were previously carried out by the displaced native species are not performed by the invasive species. This could be due to a functional inability to carry out these activities. The mandible gap waspositively correlated with the ant body mass in the 26 ant species considered. The functional inability hypothesis could be applied to other invasive ants as well as to the Argentine ant
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One of the most relevant properties of composite materials to be considered is stiffness. Fiberglass has been used traditionally as a fibrous reinforcing element when stiff materials are required. However, natural fibers are been exploited as replacements for synthetic fibers to satisfy environmental concerns. Among the different natural fibers, wood fibers show the combination of relatively high aspect ratio, good specific stiffness and strength, low density, low cost, and less variability than other natural fibers of such those from annual crops. In this work, composites from polypropylene and stone groundwood fibers from softwood were prepared and mechanically characterized under tensile loads. The Young’s moduli of the ensuing composites were analyzed and their micromechanics aspects evaluated. The reinforcing effect of stone groundwood fibers was compared to that of conventional reinforcement such fiberglass. The Halpin-Tsai model with the modification proposed by Tsai-Pagano accounted fairly for the behavior of PP composites reinforced with stone groundwood fibers. It was also demonstrated that the aspect ratio of the reinforcement plays a role in the Young’s modulus of injection molded specimens
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Este documento recoge los resultados de un estudio sobre el estado de la investigación astronómica en los centros del sistema español de investigación y desarrollo, en lo referente al trienio 1999-2001. Su objetivo es conocer y dar a conocer la situación real de las actividades investigadoras de una disciplina que se ha desarrollado espectacularmente en los últimos decenios en España ...
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We analyze the timing of photons observed by the MAGIC telescope during a flare of the active galactic nucleus Mkn 501 for a possible correlation with energy, as suggested by some models of quantum gravity (QG), which predict a vacuum refractive index similar or equal to 1 + (E/M-QGn)(n), n = 1, 2. Parametrizing the delay between gamma-rays of different energies as Delta t = +/-tau E-1 or Delta t = +/-tau E-q(2), we find tau(1) = (0.030 +/- 0.012) s/GeV at the 2.5-sigma level, and tau(q) = (3.71 +/- 2.57) x 10(-6) s/GeV2, respectively. We use these results to establish lower limits M-QG1 > 0.21 X 10(18) GeV and M-QG2 > 0.26 x 10(11) GeV at the 95% C.L. Monte Carlo studies confirm the MAGIC sensitivity to propagation effects at these levels. Thermal plasma effects in the source are negligible, but we cannot exclude the importance of some other source effect.
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Ilex paraguariensis is a native plant in Southern Brazil, whose leaves are utilized in beverages such as chimarrão and tererê. This study investigated variations of total methylxanthines in leaves from two Ilex populations collected at one-month intervals over the course of one year. The levels varied from 1.92 to 10.37 mg/g (Ijuí) and 1.77 to 9.17 mg/g (Santa Maria). Statistical analysis indicated a significative variation in the contents of all samples analysed, confirming seasonal fluctuations. These results show that the period of harvest might decisively influence the organoleptic characteristics of raw material used in industry and therefore in commercial products.
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This article reviews the life and career of Dr. Maria Josepa Arnall i Juan (1948-2002), head professor of Historiographic Science and Techniques at the University of Barcelona. Dr. Arnall was distinguished both on a personal and professional level. She performed a magnificent task as a researcher and teacher, and possessed a great work ethic, as evidenced by her rich and rigorous scientific output, described in the article. She played an active role in collaboration with the Archivists Association of Catalonia helping to train Catalan archivists. The memory of her as a person and a professional, as well as her important and valuable work, remain as her legacy
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Soitinnus: mieskuoro (TTBB).
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Quan l'abadessa del monestir de Pedralbes estableix en el contracte de Ferrer Bassa que els murals de la capella de Sant Miquel es facin a l'oli segurament fa referència a una tècnica pictòrica consistent a aglutinar els pigments amb oli i a la seva aplicació damunt d'una capa prèvia feta a base de blanc de plom. Però la tècnica que ens trobem no és aquesta: si bé s'utilitza l'oli, s'empren altres aglutinants proteics i resines terpèniques, essent la fase prèvia una pintura al fresc. Els murals estan pintats al fresc i al sec gairabé en la mateixa proporció,i la distribució dels dos procediments està perfectament planificada abans de començar a pintar. També està previst fer la profusa decoració amb daurats i platejats. Els principals problemes de conservació són es inherents a la utilització d'aglutinants orgànics. La tècnica executiva és l'element que més ha condicionat la conservació dels murals, mentre que l'ambient estable de la capella i la seva ubicació han permès que aquest cicle pictòric hagi superat prop de set-cents anys d'història en un estat molt intacte i complet.
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Background: As a result of the growing number of interventions that are now performed in the context of maternity care, health authorities have begun to examine the possible repercussions for service provision and for maternal and neonatal health. In Spain the Strategy Paper on Normal Childbirth was published in 2008, and since then the authorities in Catalonia have sought to implement its recommendations. This paper reviews the current provision of maternity care in Catalonia. Methods: This was a descriptive study. Hospitals were grouped according to their source of funding (public or private) and were stratified (across four strata) on the basis of the annual number of births recorded within their respective maternity service. Data regarding the distribution of obstetric professionals were taken from an official government survey of hospitals published in 2010. The data on obstetric interventions (caesarean, use of forceps, vacuum or non-specified instruments) performed in 2007, 2010 and 2012 were obtained by consulting discharge records of 44 public and 20 private hospitals, which together provide care in 98% of all births in Catalonia. Proportions and confidence intervals were calculated for each intervention performed in all full-term (3742 weeks) singleton births. Results: Analysis of staff profiles according to the stratification of hospitals showed that almost all the hospitals had more obstetricians than midwives among their maternity care staff. Public hospitals performed fewer caesareans [range between 19.20% (CI 18.84-19.55) and 28.14% (CI 27.73-28.54)] than did private hospitals [range between 32.21% (CI 31.78-32.63) and 39.43% (CI 38.98-39.87)]. The use of forceps has decreased in public hospitals. The use of a vacuum extractor has increased and is more common in private hospitals. Conclusions: Caesarean section is the most common obstetric intervention performed during full-term singleton births in Catalonia. The observed trend is stable in the group of public hospitals, but shows signs of a rise among private institutions. The number of caesareans performed in accredited public hospitals covers a limited range with a stable trend. Among public hospitals the highest rate of caesareans is found in non-accredited hospitals with a lower annual number of births.
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Background: As a result of the growing number of interventions that are now performed in the context of maternity care, health authorities have begun to examine the possible repercussions for service provision and for maternal and neonatal health. In Spain the Strategy Paper on Normal Childbirth was published in 2008, and since then the authorities in Catalonia have sought to implement its recommendations. This paper reviews the current provision of maternity care in Catalonia. Methods: This was a descriptive study. Hospitals were grouped according to their source of funding (public or private) and were stratified (across four strata) on the basis of the annual number of births recorded within their respective maternity service. Data regarding the distribution of obstetric professionals were taken from an official government survey of hospitals published in 2010. The data on obstetric interventions (caesarean, use of forceps, vacuum or non-specified instruments) performed in 2007, 2010 and 2012 were obtained by consulting discharge records of 44 public and 20 private hospitals, which together provide care in 98% of all births in Catalonia. Proportions and confidence intervals were calculated for each intervention performed in all full-term (3742 weeks) singleton births. Results: Analysis of staff profiles according to the stratification of hospitals showed that almost all the hospitals had more obstetricians than midwives among their maternity care staff. Public hospitals performed fewer caesareans [range between 19.20% (CI 18.84-19.55) and 28.14% (CI 27.73-28.54)] than did private hospitals [range between 32.21% (CI 31.78-32.63) and 39.43% (CI 38.98-39.87)]. The use of forceps has decreased in public hospitals. The use of a vacuum extractor has increased and is more common in private hospitals. Conclusions: Caesarean section is the most common obstetric intervention performed during full-term singleton births in Catalonia. The observed trend is stable in the group of public hospitals, but shows signs of a rise among private institutions. The number of caesareans performed in accredited public hospitals covers a limited range with a stable trend. Among public hospitals the highest rate of caesareans is found in non-accredited hospitals with a lower annual number of births.
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Digitoitu 29. 5. 2008.
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En este artículo se describe el modelo de innovación docente de Diseños Experimentales y Aplicados (DEIA), una asignatura metodológica de Psicología adaptada al Espacio Europeo de Educación Superior (EEES). El objetivo del estudio consiste en aprobar una adaptación del cuestionario Evaluación del Modelo de Innovación Docente (EMID) a la presente propuesta Europea (EMIDE) para conocer la valoración del alumnado en relación con nuestro modelo, así como estimar la adecuación de carga de trabajo prescrita. El hecho de que 270 estudiantes de DEIA completaran el EMIDE demuestra una adecuada validez factorial y un alto grado de fiabilidad. Según este estudio, los estudiantes perciben positivamente la innovación docente europea, y, en relación con la percepción de comprensión, señalan elementos relevantes a la hora de asimilar los contenidos necesarios para superar la materia, así como algunos elementos relacionados con el Campus Virtual y la semipresencialidad. La satisfacción del alumnado en relación con la propuesta parece estar más asociada a la estrategia semipresencial y al Campus Virtual, considerados como elementos innovadores en la enseñanza de la materia. Por último, se ha percibido un nivel de dedicación del estudiante menor del que se esperaba, concretamente en cuanto a las clases presenciales y al tiempo dedicado al estudio autónomo. Del estudio se concluye que es necesaria más investigación empírica para conocer los hallazgos relacionados con las adaptaciones que se están realizando de las asignaturas universitarias al EEES.
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En este artículo se describe la adaptación de la asignatura"Diseños experimentales y aplicados" de la Facultad de Psicología de la Universitat de Barcelona (UB) según las directrices de esta Universidad para adaptarse al Espacio Europeo de Educación Superior (EEES). Se realizó una investigación con el objetivo de conocer la opinión de los estudiantes respecto a la innovación docente desarrollada a través de la introducción del campus virtual. Para ello, se administró a 180 estudiantes una adaptación del cuestionario EMID (Evaluación del Modelo de Innovación Docente) que valoraba diversos aspectos: las actividades autónomas, el sistema de evaluación continuada y el campus virtual con Moodle. Los resultados del estudio muestran que los estudiantes valoran positivamente dichos aspectos, especialmente el sistema metodológico de enseñanza-aprendizaje-evaluación mediante el campus virtual, así como los materiales teórico-prácticos diseñados para que puedan adquirir las competencias metodológicas de esta asignatura.
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Invasive malignant melanoma (MM) is an aggressive tumor with no curative therapy available in advanced stages. Nuclear corepressor (NCoR) is an essential regulator of gene transcription, and its function has been found deregulated in different types of cancer. In colorectal cancer cells, loss of nuclear NCoR is induced by Inhibitor of kappa B kinase (IKK) through the phosphorylation of specific serine residues. We here investigate whether NCoR function impacts in MM, which might have important diagnostic and prognostic significance. By IHC, we here determined the subcellular distribution of NCoR in a cohort of 63 primary invasive MM samples, and analyzed its possible correlation with specific clinical parameters. We therefore used a microarray-based strategy to determine global gene expression differences in samples with similar tumor stage, which differ in the presence of cytoplasmic or nuclear NCoR. We found that loss of nuclear NCoR results in upregulation of a specific cancer-related genetic signature, and is significantly associated with MM progression. Inhibition of IKK activity in melanoma cells reverts NCoR nuclear distribution and specific NCoR-regulated gene transcription. Analysis of public database demonstrated that inactivating NCoR mutations are highly prevalent in MM, showing features of driver oncogene.
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Award-winning