Estudio de envejecimiento real en tuberías de PRFV en servicio, en redes de distribución de agua para riego

Tras la alta tasa de incidencias ocurridas en los últimos años en el sector del regadío español con tubería de PRFV de un fabricante concreto, se ha realizado un estudio comparativo entre muestras extraídas de este fabricante y de otros 4 fabricantes (que no han presentado fallos). Para ello, se realizó la extracción de muestras representativas con una antigüedad similar (unos 10 años). El objetivo era evaluar la pérdida de prestaciones con el tiempo (envejecimiento del material) -medida a través de sus propiedades mecánicas- así como comparar los resultados obtenidos entre las tuberías que presentan fallo y las que no. También se realizó un estudio exhaustivo de la composición de los tubos y sus materiales. El desarrollo de estos trabajos se ha realizado bajo el amparo del proyecto de I+D+I TUBCAL1618 de TRAGSA. Los resultados indican que la evolución de las propiedades en el tiempo de los tubos que presentan fallo no es la esperada y sus valores absolutos están por debajo de los valores declarados por el propio fabricante (la pérdida de propiedades en el tiempo es muy superior a la declarada). Estos resultados resultan coherentes con la tasa de averías que las obras en las que están instalados están sufriendo. Además, del análisis complementario de la información de calidad disponible se ha podido comprobar la enorme variabilidad de resultados. Esto es indicativo de un pobre control de proceso durante la fabricación. En el estudio detallado de las muestras y su composición se puede comprobar, también, que hay multitud de defectos de fabricación y elección de materiales que contribuyen a los fallos anticipados. Por el contrario, de los resultados de los ensayos mecánicos de la tubería de PRFV extraída de otros fabricantes –sin fallo- son, en general, muy buenos. La variabilidad de resultados -por fabricante- es escasa (indicando que los procesos de fabricación son mucho más estables y controlados). La pérdida de propiedades de los tubos es mucho menor, de media. Los valores obtenidos de pérdida de propiedades son muy inferiores a las curvas de referencia empleadas, por lo que el envejecimiento real es menor de lo previsto (y apunta a que su vida útil está garantizada). Los valores -en términos absolutos- obtenidos siguen siendo, además y en la mayoría de los casos, superiores a los requisitos de tubo nuevo de la norma para cada una de las referencias analizadas. Todo esto permite corroborar que la garantía de funcionamiento de las tuberías de PRFV está directamente relacionada con la calidad en su fabricación y el cumplimiento estricto de las especificaciones a corto y largo plazo definidas por la normativa vigente y las declaraciones de los propios fabricantes

Co-administration of human MSC overexpressing HIF-1α increases human CD34+ cell engraftment in vivo

Background: Poor graft function or graft failure after allogeneic stem cell transplantation is an unmet medical need, in which mesenchymal stromal cells (MSC) constitute an attractive potential therapeutic approach. Hypoxia-inducible factor-1α (HIF-1α) overexpression in MSC (HIF-MSC) potentiates the angiogenic and immunomodulatory properties of these cells, so we hypothesized that co-transplantation of MSC-HIF with CD34+ human cord blood cells would also enhance hematopoietic stem cell engraftment and function both in vitro and in vivo. Methods: Human MSC were obtained from dental pulp. Lentiviral overexpression of HIF-1α was performed transducing cells with pWPI-green fluorescent protein (GFP) (MSC WT) or pWPI-HIF-1α-GFP (HIF-MSC) expression vectors. Human cord blood CD34+ cells were co-cultured with MSC WT or HIF-MSC (4:1) for 72 h. Then, viability (Annexin V and 7-AAD), cell cycle, ROS expression and immunophenotyping of key molecules involved in engraftment (CXCR4, CD34, ITGA4, c-KIT) were evaluated by flow cytometry in CD34+ cells. In addition, CD34+ cells clonal expansion was analyzed by clonogenic assays. Finally, in vivo engraftment was measured by flow cytometry 4-weeks after CD34+ cell transplantation with or without intrabone MSC WT or HIF-MSC in NOD/SCID mice. Results: We did not observe significant differences in viability, cell cycle and ROS expression between CD34+ cells co-cultured with MSC WT or HIF-MSC. Nevertheless, a significant increase in CD34, CXCR4 and ITGA4 expression (p = 0.009; p = 0.001; p = 0.013, respectively) was observed in CD34+ cells co-cultured with HIF-MSC compared to MSC WT. In addition, CD34+ cells cultured with HIF-MSC displayed a higher CFU-GM clonogenic potential than those cultured with MSC WT (p = 0.048). We also observed a significant increase in CD34+ cells engraftment ability when they were co-transplanted with HIF-MSC compared to CD34+ co-transplanted with MSC WT (p = 0.016) or alone (p = 0.015) in both the injected and contralateral femurs (p = 0.024, p = 0.008 respectively). Conclusions: Co-transplantation of human CD34+ cells with HIF-MSC enhances cell engraftment in vivo. This is probably due to the ability of HIF-MSC to increase clonogenic capacity of hematopoietic cells and to induce the expression of adhesion molecules involved in graft survival in the hematopoietic niche

Determinación de la resistencia a esfuerzo cortante en ensayos de flexión a paneles sándwich PUR: análisis de las dificultades y simulación por elementos finitos

The use of the composite construction elements combining different materials with complementary characteristics, it has spread increasingly. The sandwich panels composed by external metallic sheets that they contributes resistance and core of rigid insulating thermal foam, that provides qualities that improve the thermal comfort inside all kinds of constructions. They are in use in closings and covers that shape the surrounding one of the buildings. Of the different quality controls to which they have to surrender. In this article one proposes an improvement to the indicated one in the procedure for the determination of the resistance to the shear strength, Managing to avoid many anomalous results obtained by the utilization of rigid plates in the supports. Finally, so much the problem observed as the proposed solution, they are modeled and simulate by means of the method of finite elements.La utilización de elementos constructivos compuestos, combinando distintos materiales con características complementarias, se ha extendido cada vez más. Los paneles sándwich, compuestos por capas externas de metal que les aporta resistencia y núcleo de espuma aislante térmica, que proporciona cualidades que mejoran el confort térmico en el interior de todo tipo de construcciones, se utilizan en cerramientos y cubiertas que conforman la envolvente de los edificios. De los distintos controles de calidad a que se han de someter, en este artículo se propone una mejora al indicado en las normas para la determinación de la resistencia al esfuerzo cortante, consiguiendo evitar muchos resultados anómalos obtenidos por la utilización de placas rígidas en los apoyos. Finalmente, tanto el problema observado como la solución propuesta, se modelizan y simulan mediante el método de elementos finitos

Percepción de las conductas contrarias a la convivencia en el profesorado de Educación Secundaria Obligatoria

The learning environment influences the teaching-learning process as well as the welfare of the educational community members. Moreover, it is a question addressed by numerous scientific studies.The main objective of this research project is to describe and analyze the main conflicting behaviors of students in mandatory secondary education and relate to variables such as the location of institutions and participants, teacher gender, years of seniority as a teacher, management position and educational stage.In the research we worked with a sample of 147 teachers of Physical Education actively practicing in mandatory secondary education schools. Participants completed two ad hoc questionnaires to evaluate students´ problem behaviour at school. We followed the ‘factor analysis’ approach and finally we obtained five behavioural factors. We also applied the chi-squared test or so-called ‘Exact test of Fisher’ to associate these behaviours to other relevant variables. We conclude that the most frequent unruly behaviour are disruptive attitude and verbal abuse. Behaviours related to “Defiance and bullying” are more likely to happen when teachers are women. Less experienced teachers recorded more “attention deficit” behaviours in their classroom. Teachers having experience on management positions had to deal less often with behaviours related to “attention deficit” and “misuse of materials”.La convivencia escolar en los centros educativos influye en el proceso de enseñanza-aprendizaje, así como en el bienestar de los miembros de la comunidad educativa. Además, es una cuestión abordada por numerosos estudios científicos. El objetivo principal del presente trabajo es describir y analizar las principales conductas contrarias a la convivencia en Educación Secundaria Obligatoria y relacionarlas con variables como la ciudad de procedencia, género del profesor, antigüedad en el cuerpo, desempeño de cargo directivo y ciclo educativo.Los participantes son 147 profesores de Educación Física que ejercen activamente la profesión en centros de Educación Secundaria Obligatoria. Dicha muestra cumplimentó individual y expresamente dos cuestionarios diseñados “ad hoc” para evaluar las conductas contrarias a la convivencia en el alumnado. A las conductas se les aplicó la técnica de análisis factorial obteniendo finalmente cinco factores de conducta. Además, se aplicó chi-cuadrado o test exacto de Fisher para relacionar las conductas con otras variables de interés.Se concluye que las conductas contrarias a la convivencia más frecuentes son las disruptivas y las agresiones verbales. Respecto al género del profesorado las conductas pertenecientes a “desafío y acoso” son más frecuentes cuando la profesora es mujer que cuando el profesor es hombre. Cuantos menos años lleva el profesor en el cuerpo, más frecuentes son las conductas pertenecientes a “déficit de atención”. Las conductas pertenecientes a “déficit de atención” y “mal uso de materiales” son más frecuentes cuando el profesor no desempeña ni ha desempeñado cargo directivo alguno.

Exon sequence requirements for excision in vivo of the bacterial group II intron RmInt1

<p>Abstract</p> <p>Background</p> <p>Group II intron splicing proceeds through two sequential transesterification reactions in which the 5' and 3'-exons are joined together and the lariat intron is released. The intron-encoded protein (IEP) assists the splicing of the intron <it>in vivo </it>and remains bound to the excised intron lariat RNA in a ribonucleoprotein particle (RNP) that promotes intron mobility. Exon recognition occurs through base-pairing interactions between two guide sequences on the ribozyme domain dI known as EBS1 and EBS2 and two stretches of sequence known as IBS1 and IBS2 on the 5' exon, whereas the 3' exon is recognized through interaction with the sequence immediately upstream from EBS1 [(δ-δ' interaction (subgroup IIA)] or with a nucleotide [(EBS3-IBS3 interaction (subgroup IIB and IIC))] located in the coordination-loop of dI. The δ nucleotide is involved in base pairing with another intron residue (δ') in subgroup IIB introns and this interaction facilitates base pairing between the 5' exon and the intron.</p> <p>Results</p> <p>In this study, we investigated nucleotide requirements in the distal 5'- and 3' exon regions, EBS-IBS interactions and δ-δ' pairing for excision of the group IIB intron RmInt1 <it>in vivo</it>. We found that the EBS1-IBS1 interaction was required and sufficient for RmInt1 excision. In addition, we provide evidence for the occurrence of canonical δ-δ' pairing and its importance for the intron excision <it>in vivo.</it></p> <p>Conclusions</p> <p>The excision <it>in vivo </it>of the RmInt1 intron is a favored process, with very few constraints for sequence recognition in both the 5' and 3'-exons. Our results contribute to understand how group II introns spread in nature, and might facilitate the use of RmInt1 in gene targeting.</p

Psychometric characteristics of a commuting-to-school behaviour questionnaire for families

The purposes of this study were: (a) to describe the patterns of modes of commuting to school (children) and to work (parents) separated by gender and age, (b) to validate the questions on children’s mode of commuting to and from school according to their parents, and (c) to analyse the reliability of a family questionnaire focused on commuting to school behaviours. A total of 611 parents (mean age: 43.28 ± 6.25 years old) from Granada (Spain) completed “Family commuting-to-school behaviour” questionnaire in two sessions separated by 14 days, (2016 and 2018). The validation between family and children’s questions was assessed using the Kappa and Spearman correlation coefficients, and the test–retest reliability within the family questions was assessed using the Kappa and the weighted Kappa. The children’s modes of commuting to school (mean age: 11.44 ± 2.77 years old) were mainly passive (57.7% to school) while parents’ modes of commuting to work were mainly active (71.6%). The validity of the mode of commuting was significant with high Kappa and Spearman coefficients. The test–retest reliability presented a good agreement for the mode of commuting to school in children, distance and time to school, and the mode of commuting to work in parents, while the questions on acceptable distance to walk or cycle to school showed a moderate to good agreement. The “Family commuting-to-school behaviour” questionnaire could be a useful tool to assess the mode of commuting of children, distance and time to school for researchers and practitioners

Feasibility and Reliability of a Questionnaire to Assess the Mode, Frequency, Distance and Time of Commuting to and from School: The PACO Study

Active commuting to and from school has several health implications. Self-reporting is the most common assessment tool, but there is a high heterogeneity of questionnaires in the scientific literature. The purpose of this study was to analyse the feasibility and reliability of the Spanish “New Version of Mode and Frequency of Commuting To and From School” questionnaire in children and adolescents. A total of 635 children (5–12 years old) and 362 adolescents (12–18 years old) filled out the questionnaire twice (14 days apart). Feasibility was evaluated using an observational checklist. The test-retest reliability of the “New Version of Mode and Frequency of Commuting To and From School” questionnaire and the distance and time to school were examined using the kappa and weight kappa coefficient (κ). No misunderstanding of questions was reported. The time to complete the questionnaire was 15 ± 3.62 and 9 ± 2.26 min for children and adolescents, respectively. The questionnaire showed substantial and almost perfect kappa coefficients for the overall six items (k = 0.61–0.94) in children and adolescents. The “New Version of Mode and Frequency of Commuting To and From School” questionnaire is a feasible and reliable questionnaire in Spanish children and adolescents.Spanish Ministry of Economy, Industry and CompetitivenessEuropean Union (EU) DEP2016-75598-RUniversity of Granada, Plan Propio de Investigacion 2016, excellence actions: Units of ExcellenceUnit of Excellence on Exercise and Health (UCEES)Junta de AndaluciaConsejeria de Conocimiento, Investigacion y UniversidadesEuropean Union (EU) SOMM17/6107/UGREuropean Social Fund (ESF