205 research outputs found

    Comportamiento cíclico de una acero St-52-3N: Influencia de los módulos de elasticidad en las estimaciones de vida a fatiga

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    Dada la dependencia de los módulos de elasticidad en los métodos de estimación de vida a fatiga, se analiza el comportamiento cíclico y la variación de estos con el grado de deformación. En este estudio se llevan a cabo una serie de experimentos de fatiga uniaxial en control de deformación, con R=-1, a bajo número de ciclos y a temperatura ambiente, para caracterizar el comportamiento cíclico del acero al carbono St-52-3N. Se realizaron ensayos de fatiga uniaxial tanto de tracción como de torsión. Se compara los valores de los módulos de elasticidad monotónico y cíclico, además de los valores cíclicos correspondientes a los segmentos de descarga y carga (E1 ,E2) (acordes con ISO/DIS 121106). Se pone de manifiesto la variabilidad cometida al calcular el incremento de deformación plástica según el Método Estándar de ensayo que utilicemos (BS/ISO, ASTM, AECMA) y que determinará en cada caso la estimación del módulo de elasticidad cíclicoUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Desarrollo multidisciplinario en investigación y docencia del centro universitario UAEM Valle de México

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    DESARROLLO MULTIDISCIPLINARIO EN INVESTIGACIÓN Y DOCENCIA DEL CENTRO UNIVERSITARIO UAEM VALLE DE MÉXICOLa Universidad Autónoma del Estado de México ha evolucionado a través de sus 188 años de historia, dedicada a la educación, la investigación, la cultura y el deporte, como sus grandes ejes rectores, formadora de hombres y mujeres con un alto sentido humanista y ético, contribuyendo a lograr nuevas y mejores formas de existencia y convivencia social. Durante el proceso de desconcentración de la UAEM, se crearon las Unidades Académicas y Centros Universitarios para brindar el servicio de educación a más jóvenes en todo el Estado de México, este Centro Universitario fue uno de los primeros y a sus veinte años de existencia se está consolidando como uno de los mejores. Es en los últimos años que se ha venido impulsando la investigación al contar con cuerpos académicos, en formación y en consolidación, con infraestructura de primera tanto en equipo como en laboratorios especializados, con profesores de tiempo completo que participan en congresos, seminarios y presentan publicaciones en revistas indexadas. Por ello para celebrar esos veinte años de existencia de esta honorable institución, se planeó la compilación de esta obra que es parte del quehacer multidisciplinario en investigación y docencia como parte del Plan de Desarrollo 2013-2017, de esta administración. Esta obra reúne investigaciones tanto de profesores como de alumnos desde las diferentes ramas del saber en las que se inscriben sus siete licenciaturas, Actuaría, Administración, Contaduría, Derecho, Economía, Relaciones Económicas Internacionales e Informática Administrativa, tanto presencial como a distancia, así como sus tres ingenierías, Industrial, en Computación y Sistemas y Comunicaciones, así como gracias a la vinculación y colaboración académico – científica que se tiene con otras instituciones de educación superior a nivel nacional, como el Instituto Tecnológico de Orizaba, la Universidad Autónoma de San Luis Potosí, la Universidad Nacional Autónoma de México, la Universidad Autónoma Metropolitana, Universidad Politécnica de Victoria, el Instituto Politécnico Nacional entre otras. En el capítulo 1 se abordan seis temáticas diferentes de vanguardia en el área de las Ingenierías, en los capítulos 2 y 3 se incluyen temas de interés y gran relevancia en materia de ciencias sociales, política y economía. Se hace extensivo un reconocimiento para todos los que participaron tanto en la revisión de los trabajos, como en la compilación del producto final de este Libro intitulado “Desarrollo Multidisciplinario en Investigación y Docencia del Centro Universitario UAEM Valle de México”

    La vid silvestre en México. Actualidades y potencial

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    En ocho capítulos se aborda el estado del arte de la vid silvestre en MéxicoEl estudio de las especies vegetales nativas de México representa un reto que cada día más investigadores mexicanos asumen. Durante muchos años, el apoyo a la investigación pública ha sido mínimo; desde el punto de vista agronómico es insuficiente para avanzar a la velocidad que requiere nuestro país para afrontar problemas de producción y distribución de alimentos. Por esa razón, entre otras, me es grato presentar esta obra que compila parte de los trabajos de la Red de Vid Silvestre patrocinada por el Sistema Nacional de Recursos Fitogenéticos (sinarefi) dependiente de la sagarpa; trabajos apuntalados por investigadores que sin pertenecer a la red han colaborado en el estudio de las plantas del género Vitis. En este libro se muestra el potencial del país para aprovechar el recurso vid, empleado desde antes de la conquista española por nativos mexicanos que conocían sus bondades. Es necesario continuar el avance en el conocimiento de este recurso, por ello el presente libro pretende invitar a toda persona interesada en contribuir con el rescate y conservación de las vides mexicanas. Los autores y editores, así como las instituciones en donde laboramos y aquellas que patrocinan estas investigaciones, esperamos se cumpla este objetivo y que el lector, alumno, profesor, investigador, público en general, disfrute esta lectura y, sobre todo, se interese en el recurso VitisSEP, SINAREFI, UAEME

    Inovação no Desenvolvimento do Curso Online Acessível a Todos (MOOC) sobre “Redes Ultra-densas 5G e sua Evolução”

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    Muitos dos novos dispositivos de comunicações móveis serão aparelhos que alimentam e monitorizam as nossas casas, infraestruturas urbanas e transportes. Controlar drones a milhares de quilómetros de distância, realizar cirurgias remotas ou estar imerso em vídeo com latência reduzida transformará certamente o acesso às tecnologias de informação e comunicação digitais. Estes são alguns dos aspetos que tornarão a quinta geração das comunicações móveis (5G) uma revolução, um impulso para a economia, e o foco de todos os intervenientes atuais na área das telecomunicações. Com este intuito, o planeamento e a crescente densidade de implantação destas novas redes introduzem novos desafios de otimização. Que elementos serão adicionados em relação às gerações anteriores? Baseados num Curso Online Acessível a Todos (MOOC) anteriormente desenvolvido na UC3M (UC3M Staff, 2022), o MOOC sobre redes ultra-densas 5G e sua evolução foi elaborado pelos investigadores da Marie Skłodowska-Curie Actions (MSCA) ITN/ETN Europeia (teamUp5G Reserachers, 2022), denominada TeamUp5G (Teamup5G, 2022; Pérez Leal et al., 2020) e apresenta as tecnologias mais importantes que suportam comunicações móveis 5G, com ênfase no aumento de capacidade e redução de energia, que facilitam o desenvolvimento de redes com pequenas células. Os conteúdos abrangem aspectos desde tecnologias de comunicação até casos de utilização, prototipagem e o futuro próximo, sem esquecer questões como a gestão de interferência, eficiência energética ou gestão de espectro. O objetivo do MOOC (TeamUp5G, 2022) é preencher a lacuna na aprendizagem ao nível dos estudos de graduação e pós-graduação, em conteúdos relacionados com tecnologias 5G emergentes e suas aplicações, incluindo a 6G futura. O público-alvo envolve engenheiros, investigadores, profissionais e estudantes. O artigo descreve o conteúdo e os resultados de aprendizagem do MOOC, as principais tarefas e recursos envolvidos na sua criação, as contribuições conjuntas do setor académico e não académico, e aspectos como a conformidade relativamente aos direitos de autor, garantia de qualidade, testes e detalhes sobre comunicação e inscrição, seguidos da discussão das lições extraídas.Este trabalho foi financiado pelo programa de investigação e inovação Horizonte 2020 da União Europeia através da Rede Europeia de Estágios (ETN) Marie Skłodowska-Curie TeamUp5G, acordo de bolsa N.º 813391, pela SNF Scientific Exchange - AISpectrum (projecto 205842) e UIDB/50008/2020. Os autores agradecem as contribuições da equipa audiovisual da UC3M responsáveis pela edição do MOOC, e da equipa responsável pelos direitos de autor e pela gravação na plataforma edX.info:eu-repo/semantics/acceptedVersio

    Predicting species dominance shifts across elevation gradients in mountain forests in Greece under a warmer and drier climate

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    The Mediterranean Basin is expected to face warmer and drier conditions in the future, following projected increases in temperature and declines in precipitation. The aim of this study is to explore how forests dominated by Abies borisii-regis, Abies cephalonica, Fagus sylvatica, Pinus nigra and Quercus frainetto will respond under such conditions. We combined an individual-based model (GREFOS), with a novel tree ring data set in order to constrain tree diameter growth and to account for inter- and intraspecific growth variability. We used wood density data to infer tree longevity, taking into account inter- and intraspecific variability. The model was applied at three 500-m-wide elevation gradients at Taygetos in Peloponnese, at Agrafa on Southern Pindos and at Valia Kalda on Northern Pindos in Greece. Simulations adequately represented species distribution and abundance across the elevation gradients under current climate. We subsequently used the model to estimate species and functional trait shifts under warmer and drier future conditions based on the IPCC A1B scenario. In all three sites, a retreat of less drought-tolerant species and an upward shift of more drought-tolerant species were simulated. These shifts were also associated with changes in two key functional traits, in particular maximum radial growth rate and wood density. Drought-tolerant species presented an increase in their average maximal growth and decrease in their average wood density, in contrast to less drought-tolerant species

    Epigenetic loss of RNA‑methyltransferase NSUN5 in glioma targets ribosomes to drive stress adaptive translational program

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    Tumors have aberrant proteomes that often do not match their corresponding transcriptome profiles. One possible cause of this discrepancy is the existence of aberrant RNA modification landscapes in the so-called epitranscriptome. Here, we report that human glioma cells undergo DNA methylation-associated epigenetic silencing of NSUN5, a candidate RNA methyltransferase for 5-methylcytosine. In this setting, NSUN5 exhibits tumor-suppressor characteristics in vivo glioma models. We also found that NSUN5 loss generates an unmethylated status at the C3782 position of 28S rRNA that drives an overall depletion of protein synthesis, and leads to the emergence of an adaptive translational program for survival under conditions of cellular stress. Interestingly, NSUN5 epigenetic inactivation also renders these gliomas sensitive to bioactivatable substrates of the stress-related enzyme NQO1. Most importantly, NSUN5 epigenetic inactivation is a hallmark of glioma patients with long-term survival for this otherwise devastating disease

    Rate and duration of hospitalisation for acute pulmonary embolism in the real-world clinical practice of different countries : Analysis from the RIETE registry

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    The Eurasian Modern Pollen Database (EMPD), version 2

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    The Eurasian (nee European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).Peer reviewe

    Enabling planetary science across light-years. Ariel Definition Study Report

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    Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution

    Utilization of mechanical power and associations with clinical outcomes in brain injured patients: a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

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    Background: There is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes. Methods: In this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale ≤ 12 before intubation) who required mechanical ventilation (MV) ≥ 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS). Results: We included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22). Conclusions: Exposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation
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