Mechanical behaviour of stamped aluminium alloy components by means of response surfaces

In the automotive industry, the use of stamped aluminium alloy components has become a very common occurrence. For the appropriate design of these components, it is necessary to know how the manufacturing process a ects the material properties. In the first place, high plastic strains ("p) can be generated during the stamping process, which can result in a change in the residual stress and mechanical properties in the plastically deformed areas. Furthermore, if a last coat of paint that is usually subjected to a thermal cycle, characterized by temperature (T) and exposure time (t), is applied, it can also influence mechanical behaviour. Consequently, this paper studies how both processes a ect the mechanical behaviour of an aluminium alloy of the 5000 series, commonly used in these types of components. In particular, the mechanical properties such as the yield stress at 0.2% ( 0.2), the ultimate tensile strength (sut) and the engineering strain at break (e f ) have been analysed. To achieve this, a response surface technique, based on the design of experiments, has been used. The response surfaces obtained allow for the prediction of mechanical properties 0.2, sut and e f for any combination of values of t, T and "p.Junta of Castile and Leon through grant ref. BU053U1

EJERCICIOS VINCULADOS CON LA VIDA PARA FAVORECER EL TRABAJO INDEPENDIENTE DESDE LA MATEMÁTICA EN LA SECUNDARIA BÁSICA

The uninterrupted development of society means that every year there are higher and higher demands on man, on his integral training. An important role in training the student in the development of his mental potential and in his mathematical preparation is played by independent work. In this respect, it is necessary to introduce methods and ways that favor the teaching of this subject in Basic Secondary Education. Therefore, the present research aims to offer exercises linked to life in order to favor independent work in the students of the seventh grade of Basic Secondary School. During the investigation different instruments were applied, supported by methods of the empirical and theoretical level that allowed to obtain a more real information of the state of the raised problem. The theoretical references were systematized from philosophical, sociological, psychological, pedagogical and didactic positions. The results obtained show a positive transformation, since it is observed a strengthening in the development of the independent work in the students of the seventh grade of the Basic Secondary School.El desarrollo ininterrumpido de la sociedad hace que cada año se planteen exigencias cada vez más altas al hombre, a su formación general integral. Un papel importante en la formación del alumno en el desarrollo de sus potencialidades mentales y en su preparación matemática lo desempeña el trabajo independiente. Al respecto, es necesario introducir métodos y vías que favorezcan la enseñanza del mismo en la Educación Secundaria Básica, por lo que la presente investigación tiene como objetivo ofrecer ejercicios vinculados con la vida para favorecer el trabajo independiente en los alumnos de séptimo grado de la escuela Secundaria Básica. Durante la investigación se aplicaron diferentes instrumentos, sustentados en métodos del nivel empírico y teórico que permitieron obtener una información más real del estado del problema planteado. Se sistematizaron los referentes teóricos desde posiciones filosóficas, sociológicas, psicológicas, pedagógicas y didácticas. Los resultados obtenidos muestran una transformación positiva, pues se observa un fortalecimiento en el desarrollo del trabajo independiente en los alumnos del séptimo grado de la Secundaria Básica

Puccinia spore concentrations in relation to weather factors and phenological development of a wheat crop in northwestern Spain

Rust is one of the main diseases affecting wheat crops in Spain, causing significant yield and quality losses. Research on its identification and quantification in the air is a worldwide priority due to the importance of this crop as a source of food and feed. The objective of this study is to determine the temporal variation of airborne spores of Puccinia and their relationship with meteorological variables and the phenological development of a wheat crop in Northwestern Spain during two growing seasons. The study was conducted in A Limia, Ourense, located in Northwestern Spain, during the wheat growing seasons of 2021 and 2022. The Lanzoni VPPS 2010 spore trap was used to collect airborne spores, which were identified using optical microscopy. The wheat growing season was less than 95 days during both years, and wheat rust spores were detected during all phenological stages of the crop. Concentrations were higher than 100 spores/m3 from the booting stage to senescence, mainly in 2021. Statistical analyses showed that temperature was the meteorological variable that most influenced Puccinia concentrations in the air in both years. The modification of a prediction model proposed by other authors for wheat rust, which takes into account mean temperature (10–25 °C), dew point temperature (<5 °C), and nighttime temperature (10–20 °C), allowed us to tentatively predict the increase in Puccinia concentrations in the year 2022 when these conditions occurred for four or five consecutive days. This research is the first in Spain to report the presence of rust-causing Puccinia spores in the air during all phenological stages of the wheat crop and provides useful information for designing management strategies, considering temperature values

LA MAESTRÍA EN DIRECCIÓN EDUCACIONAL: CAMINO A LA EXCELENCIA ACADÉMICA

The training of administrators constitutes one of the essential aspects of the Policy of the Cuban State and Government, legislated in resolutions and state documents and gathered in the strategies at all the levels of administration; The program of Master in Educational Management comes to be the ideal answer to make concrete such aspiration and to take care of this priority in the Ministry of Education (Mined, acronym in Spanish). The academic program, structured by diploma, courses and non-teaching activities that provide 89 credits, sets standards in the training and improvement of managers and has a direct impact on their quality, with 40% of enrollment in the first edition promoted to senior management positions, 60% with participation in international and national scientific meetings and 72.0% acts for the defense of their theses, corroborate its validity, while in possession of aspiring to academic excellence.La superación de cuadros y reservas, constituye uno de los aspectos esenciales de la Política de Cuadros del Estado y Gobierno cubanos, legislada en resoluciones, circulares y documentos estatales y recogida en las estrategias a todos los niveles de dirección; si a ello se suma la impronta de concebirla desde un marcado enfoque investigativo, que impacte en todos los sectores de la sociedad, no caben dudas de que el programa de Maestría en Dirección Educacional viene a ser la respuesta ideal para concretar tal aspiración y atender dicha prioridad en el Mined. El programa académico estructurado por diplomados, cursos y actividades no lectivas que aportan 89 créditos, marca pautas en la formación y superación de directivos e impacta directamente en su calidad, con un 40% de la matrícula en la Edición I promovida a cargos de dirección superiores, un 60% con participación en eventos científicos internacionales y nacionales y un 72.0% aptos para la defensa de sus tesis, corroboran su validez, a la vez&nbsp; que aspira a la excelencia académica.&nbsp;&nbsp;&nbsp

EL MODO DE ACTUACIÓN PROFESIONAL MÉDICO DEL ESTUDIANTE DE MEDICINA EN FORMACIÓN INICIAL

The training of the medical student has been the object of occupation throughout history, it has been directed to solve health problems through an integral medical attention, which constitutes a demand of society and the health system. The training model for medical students must be in line with the demands of the historical context, which requires a professional capable of resolving the contradictions of medical practice. The present research focuses on the training of the medical professional's way of acting (MAPMe, acronym in Spanish), of the medical student in initial training, from the growing need for the training process to take place, from the first years of the career, in the coherent relationship between theory and practice, a key role in the expansion of the common space shared by teachers and medical specialists, with students and the population. The main theoretical results are materialized in a methodology that provides training levels of the medical performance of medical students, as well as dimensions, indicators and sub-indicators that make it possible to evaluate the changes operated. The practical results are synthesized in the interventional aspect of the methodology, which is centered on three interrelated stages, in order to specify the levels, referred to previously. The research contains the operationalization of the research variable, the main transformations revealed in the experiment, and the results of the consultation with specialists, who corroborate the validity of the methodology in its theoretical and interventional aspect.La formación del estudiante de Medicina ha sido objeto de ocupación a lo largo de la historia, ha estado dirigida a resolver problemas de salud mediante una atención médica integral, lo que constituye una exigencia de la sociedad y del sistema de salud. El modelo de formación del estudiante de Medicina debe estar en consonancia con las exigencias planteadas por el contexto histórico, que exige un profesional capaz de resolver las contradicciones de la práctica médica. La presente investigación centra el estudio en la formación del modo de actuación profesional médico (MAPMe, acrónimo en español), del estudiante de Medicina en formación inicial, a partir de la necesidad creciente de que el proceso formativo transcurra, desde los primeros años de la carrera, en la relación coherente teoría–práctica, papel clave en la ampliación del espacio común que comparten los profesores y especialistas médicos, con los estudiantes y la población. Los principales resultados teóricos se concretan en una metodología que aporta niveles de formación del MAPMe, así como dimensiones, indicadores y subindicadores que posibilitan evaluar los cambios operados. Los resultados prácticos se sintetizan en el aspecto interventivo de la metodología, centrada en tres etapas relacionadas entre sí, para concretar los niveles, referidos con anterioridad. La investigación contiene la operacionalización de la variable investigativa, las principales transformaciones reveladas en el experimento, y los resultados de la consulta a especialistas, quienes corroboran la validez de la metodología en su aspecto teórico e interventivo

Sensibilidad in vitro de cepas cubanas de Aspergillus spp. de origen clínico y ambiental

Introduction: The behavior of antifungal susceptibility of Aspergillus spp. in Cuba remains unknown. The antifungals recommended to treat aspergillosis are amphotericin B, itraconazole, voriconazole and echinocandins. The influence of the environment may set off the emergence of drug-resistance in these microorganisms.Objective: To evaluate in vitro susceptibility of Aspergillus spp. strains to amphotericin B, itraconazole and voriconazol, and the relationship between susceptibility patterns and their origin.Materials and methods: Minimum inhibitory concentrations of amphotericin B, itraconazole and voriconazole were determined for 60 Aspergillus spp. strains of clinical and environmental origin using the M38-A2 method of the Clinical and Laboratory Standards Institute.Results: We found 21 amphotericin B resistant strains (mainly from clinical samples and hospital environments), as well as three itraconazole resistant strains (from non-hospital outdoor and indoor environments). No voriconazole resistance was found. No relationship was found between strain origin and susceptibility.Conclusions: Results suggest the possible existence of environmental factors or interactions with resistant genotypes which may give rise to resistant phenotypes in our country. This is the first report of in vitro  Aspergillus spp. resistant strains in Cuba. These studies should be broadened and include molecular and phylogenetic analyses.Introducción. En Cuba se desconoce el comportamiento de la sensibilidad de Aspergillus spp. a los antifúngicos recomendados para el tratamiento de la aspergilosis: la anfotericina B, el itraconazol, el voriconazol y las equinocandinas. La influencia del ambiente puede condicionar la aparición de resistencia en estos microorganismos.Objetivo. Evaluar la sensibilidad in vitro de cepas de Aspergillus spp. a la anfotericina B, el itraconazol y el voriconazol, y la relación de los patrones de sensibilidad con su origen.Materiales y métodos. Se determinaron las concentraciones inhibitorias mínimas de la anfotericina B, el itraconazol y el voriconazol para 60 cepas de Aspergillus spp. de origen clínico y ambiental mediante el método M38-A2 del Clinical and Laboratory Standard Institute.Resultados. Se encontraron 21 cepas resistentes a la anfotericina B (principalmente en muestras clínicas y ambientes hospitalarios) y tres cepas resistentes al itraconazol (en ambientes interiores y exteriores no hospitalarios). No se hallaron cepas resistentes al voriconazol. No se encontró relación entre el origen de las cepas y su sensibilidad.Conclusiones. Se sugiere la posible existencia de factores ambientales o interacciones con genotipos resistentes que pueden dar origen a fenotipos resistentes en Cuba. Este es el primer reporte del país de cepas de Aspergillus spp. resistentes in vitro. Los resultados ameritan ampliar el estudio para incluir análisis moleculares y filogenéticos

Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials.

Funder: laura and john arnold foundationBACKGROUND: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ). METHODS: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. RESULTS: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. CONCLUSIONS: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care

Sustitución de las sustancias limpiadora y reveladora para realizar la inspección con líquidos penetrantes

La presencia de las uniones soldadas en muchas estructuras hace que las inspecciones que se le realicen sean muy importantes. En este trabajo se realizó la inspección mediante un líquido penetrante a un grupo de estas uniones. Fue necesario sustituir el limpiador y el revelador pues no se contaba con estas sustancias. La sustitución realizada con nafta y polvo de tiza respectivamente fue posible, debido a que los resultados obtenidos concuerdan con los que plantean la bibliografía y con comparaciones realizadas con uniones que tenían defectos conocidos

Effect of temperature on isolates of Cladosporium cladosporioides collected from the air of Havana, Cuba

Se evaluó in vitro el efecto de la temperatura en el crecimiento, la esporulación y la germinación de esporas de 13 aislados de C. cladosporioides, recolectados de la atmósfera de La Habana, Cuba. Ocho aislados crecieron óptimamente a 25°C, tres en el rango de 25-28°C y las dos restantes entre 25-30°C y 10-28°C, respectivamente. Seis aislados presentaron la mayor esporulación a 25°C y siete a 28°C. El mayor porcentaje de germinación se observó a 25°C en dos aislados, a 28°C en seis, y a 30°C en tres. A 37°C ningún aislado creció ni esporuló, sin embargo se detectó germinación. Los aislados pueden agruparse en tres conjuntos considerando la respuesta fisiológica ante las temperaturas evaluadas, lo que evidencia la variabilidad en relación a este factor ambiental. Esta investigación es una contribución al conocimiento sobre la influencia de un determinante ecológico en el ciclo de vida de C. cladosporioides.The effect in vitro of temperature on growth, sporulation and spore’s germination of 13 isolates of C. cladosporioides, collected from the atmosphere of Havana, Cuba has been evaluated. Eight isolates grew optimally at 25 °C, three in the range among 25-28 °C and the remaining two between 25-30 °C and 10-28 °C, respectively. Six isolates showed the highest sporulation at 25 °C and seven at 28 °C. The highest percentage of germination was observed at 25 °C in two isolates, at 28 °C in six, and at 30 °C in three. At 37 °C no isolate grew or sporulated, however germination was detected. The isolates can be grouped into three clusters considering the physiological response to the temperatures evaluated, which shows a diversity and relationship with this environmental factor. This research is a contribution to the knowledge about the influence of an ecological determinant in the life cycle of C. cladosporioides