The role of the autophagy in the differential vulnerability and the integrated stress response to the cerebral ischemia = El papel de la autofagia en la vulnerabilidad diferencial y en la respuesta integrada al estrés en la isquemia cerebral

142 p.El coste social y económico del accidente cerebrovascular (CVA) está continuamente en aumento y hasta la fecha hay pocas posibilidades de reducir la mortalidad o la discapacidad derivadas de esta patología. Por ello la búsqueda de nuevas dianas terapéuticas para su aplicación en clínica constituye una necesidad prioritaria. En el presente estudio se estudió la respuesta autofágica a la isquemia cerebral y su relación con el estrés del retículo. El objetivo era profundizar en el conocimiento de estos mecanismos, que constituyen potenciales dianas terapéuticas contra el CVA. En el primer capítulo, se realizó un estudio comparativo de la respuesta autofágica entre dos estructuras cerebrales (corteza cerebral e hipocampo) que presentan una vulnerabilidad diferencial a la isquemia. Para ello, se utilizó un modelo ex vivo de isquemia basado en el uso de secciones cerebrales. Este modelo permite la comparación de respuestas de diferentes estructuras en idénticas condiciones experimentales (en particular, se utilizaron 30 minutos de privación de oxígeno y glucosa [OGD] seguido de 3 horas en condiciones normóxicas [RL, reperfusion like]. Para caracterizar la actividad autofágica se midieron los niveles tanto de marcadores de inducción de autofagia como de sustratos específicos de autofagia (estimando así el flujo autofágico). Los resultados obtenidos permitieron concluir que la OGD induce una respuesta autofágica rápida en la corteza cerebral que no se observó en el hipocampo. El papel neuroprotector de la autofagia en la corteza cerebral parece implicar el control de los niveles de poliubiquitina y de la liberación de glutamato. El segundo capítulo compara la respuesta autofágica entre estructuras utilizando un modelo de isquemia cerebral global. Este modelo permitió extender los resultados descritos en el capítulo anterior a un modelo in vivo. Se analizó tanto la respuesta autofágica a la isquemia como su relación con la respuesta a las proteínas mal plegadas (UPR) inducida por el estrés de retículo endoplásmico. Tanto en la corteza cerebral como en la estructura hipocampal CA1 se observó actividad autofágica que no pudo ser detectada en la región hipocampal CA3. La respuesta autofágica en CA1 no parece suficiente para combatir el estrés de retículo, lo que explica la presencia de secuestosomas (agregados de proteínas mal plegadas) observados en las neuronas de esta estructura. La activación farmacológica de la UPR incrementó la actividad autofágica, eliminando los secuestosomas y reduciendo el daño isquémico. El tercer capítulo analiza la relación entre autofagia y la vía PERK de la UPR en un modelo de cultivos organotípicos de hipocampo sometidos a OGD y RL. Este modelo permite controlar la concentración de fármaco que llega a las neuronas y obtener muestras de una forma rápida, lo que permite estudiar diferencias en las respuestas entre tiempos muy cortos. El estudio mostró que la fosforilación de eIF2α (marcador de la activación de la vía PERK) presentó una respuesta rápida y de corta duración. Cuando está fosforilación se mantuvo a lo largo de la RL, se produjo un efecto neuroprotector mediado por ATF4 (activating transcription factor 4). Se ha descrito que ATF4 es capaz de producir una respuesta citoprotectora conocida como respuesta integrada al estrés (ISR, integrated stress response). La ISR incluye la activación de la autofagia y el aumento de la actividad antioxidante. Al contrario de lo observado en otros modelos de hipoxia, en el modelo aquí utilizado el efecto neuroprotector de ATF4 se debe a una respuesta antioxidante más que a una activación de la autofagia. Esto permitió concluir que el peso específico de los distintos componentes de la ISR depende del contexto celular y del modelo experimental

La innovación como factor de competitividad de las PYMEs

Las políticas de internacionalización e innovación son frecuentemente consideradas como factores clave para mejorar la competitividad de las empresas, impulsar su crecimiento y el del conjunto de la economía. En este trabajo se analiza la relación entre la actividad exportadora e innovadora de las pymes manufactureras españolas utilizando datos de la Encuesta sobre Estrategias Empresariales para el período 1990-2011. Los resultados muestran una fuerte asociación positiva entre internacionalización e innovación, actividades altamente persistentes. Estos resultados sugieren, de forma tentativa, que las políticas de internacionalización e innovación deberían definirse y aplicarse de forma coordinada o incluso integrada

Sustainable agriculture through perennial grains: wheat, rice, maize, and other species. A review

Grain crops are an important part of the human diet, accounting for a third of the consumed calories. Throughout human history, annual grain crops with high yields have been obtained through domestication. However, the “annual” characteristic brings associated a series of economic and environmental disadvantages, such as soil erosion or low soil resources use, that can be solved if the agriculture of annual varieties evolves towards perenniality. For this reason, there are numerous research groups dedicated to study and obtain perennial varieties of the most cultivated grain crops. In this review article, we have summarized the most important advances related to the subject, focusing on the domestication and hybridization of the most productive grains globally: wheat, rice, maize, rye and sorghum. We highlight their benefits for sustainable agriculture worldwide due to perennial grains may contribute to reducing erosion, acting avoiding carbon losses, reducing nutrient losses to waters or capturing nutrients deeper in soil when they are scarce, reducing farm costs and thus, increasing the effectiveness of agricultural grain crops. Despite perennial grain crops having disadvantages, they possess outstanding characteristics which make them resilient crops to deal with the imminent climate change. However, maintaining the perenniality trait without reducing genetic biodiversity is a great challenge of current scientific importance that must be deeply considered.Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGMinisterio de Ciencia e Innovación | Ref. FJC2019-039176-IXunta de Galicia | Ref. ED481D-2021/01

One swallow does not make a summer : episodes and persistence in high growth

This paper analyzes firms' episodes (spells) of high growth (HG) using a sample of Spanish manufacturing firms observed over two decades. The use of duration models allows us to investigate the following: (i) the probability of experiencing HG episodes, (ii) persistence in HG, and (iii) the determinants of the transitions in and out of the HG state and whether their impact varies over the business cycle. We find that about half of the firms experience at least one HG episode, but they seldom experience more than one. Moreover, high-growth status is rarely repeated due to high first-year selection. Yet, in subsequent years beyond the first one, the hazard rate from HG status falls substantially. These results suggest an "episodic" nature of HG and further allow us to identify two groups of firms characterized by the following: (i) (relatively) long HG spells and short no high-growth (NHG) spells and (ii) short HG spells and long NHG spells. In addition, some firm and market (demand) characteristics increase the probability of becoming an HG firm and enhancing HG persistence. Finally, during the downturn, the role of younger age and smaller size in explaining HG decreases

La constitución de una sociedad mercantil dedicada a la peletería

Traballo fin de grao (UDC.DER). Dereito. Curso 2015/201

Percepción de las Estrategias del Fan-page de ‘Importaciones el 10’ y su incidencia en la decisión de compra de sus consumidores en la ciudad de Trujillo en el año 2018

Años atrás las redes sociales era un tema muy poco conocido por las personas en general donde Facebook, YouTube, Twitter entre otras no eran más que palabras desconocidas en nuestro vocabulario, esto gracias al avance de la tecnología y con el pasar de los años fue cambiando tanto así que el impacto que ha tenido en nuestra forma de vida es de una manera mensurable donde la gente mantiene el contacto durante más tiempo o sentimos la necesidad de estar conectados o informados de lo que sucede en todas partes del mundo frente a ello la presente tesis analiza la Percepción que tiene el Fan-page de ‘Importaciones el 10’ y su incidencia en la decisión de compra de sus consumidores en la ciudad de Trujillo en el presente año, formulando como objetivo general de la investigación determinar el nivel de percepción del fan-page de ‘Importaciones el 10’ y su incidencia en la decisión de compra de sus consumidores en la ciudad de Trujillo en el año 2018, para lo cual se aplicó un estudio descriptivo – no experimental de corte trasversal. Aquí se determinó clientes que por lo menos han hecho una compra a través de Importaciones el 10 donde se sienten en confianza comprar o adquirir un producto a través de medios digitales. Los resultados muestran que la percepción incide positivamente en la decisión de compra por lo tanto para esta empresa que está en el rubro a través de medios digitales es de vital importancia manejar con bastante cuidado el tema de imagen, contenido e interacción con los consumidores

Straightforward Synthesis of Novel Acene-Based Aryne Precursors

Large polycyclic o-(trimethylsilyl)aryl triflates are easily obtained by reaction of commercially available bisaryne precursors with cyclopentadienones. The transformation involves controlled generation of one of the aryne functionalities, trapping by Diels–Alder reaction with a dienone, and chelotropic extrusion of CO. The newly synthesized triflates are precursors of acene-based arynes, including a didehydropentaceneFinancial support from the Spanish Ministry of Science and Competitiveness (MINECO, CTQ2013-44142-P and MAT2013-46593-C6-6-P), the European Union (Project PAMS, contract no. 610446), Xunta de Galicia (GPC2014/25), and FEDER is gratefully acknowledged. D.R.-L. thanks the Spanish Ministry of Education for the award of an FPU fellowshipS

Reasons for choosing and completing nursing studies among incoming and outgoing students: A qualitative study

Background The shortage of nurses is causing instability and crisis in health systems and will continue. The WHO reinforced the importance of recruiting and retaining new students. Authors of various studies recommend the need to identify and understand the reasons for pursuing a nursing degree. Objectives To determine students' preference for nursing studies and to identify the reasons for choosing, continuing, and completing a bachelor's degree in nursing. Design Qualitative, descriptive study. Participants 106 nursing students at the University of Huelva (Spain) participated during their first year (2017) and final year (2021) of the nursing degree. Methods This study was conducted with the same group of students in two phases. Data were collected in writing in a document with open-ended questions and no maximum wordcount. The responses were analysed using content analysis. Results A total of 76.4 % of participants stated that nursing had been their first choice. The main reasons for choosing a nursing degree were associated with fulfilment, and a desire to help others and interact with them. The reasons for completing their studies were primarily related to an interest in providing professional care, showing a deeper and more concrete knowledge of nursing care work. Conclusion For most participants, nursing was their first choice due to a strong intrinsic motivation related to self-satisfaction in helping others. The reasons for completing this degree had extrinsic motivations linked to nursing activity in hospital. Areas such as management, teaching, or research were not interesting to our students. Knowing the causes of this lack of interest could help us attract them to these areas.Funding for open access charge: Universidad de Huelva / CBU

Components of the nursing role as perceived by first-year nursing students

Background: Identifying and acquiring the nursing role is key to the development of nurses’ professional identity. Understanding nursing students’ perceptions in this regard will enable nursing educators to choose teaching strategies that lead to positive development of their students’ professional identity. Objectives: To describe how nursing students perceive the different components of the nursing role at the beginning of the nursing degree. Design: Cross-sectional, descriptive, observational study. Participants/settings: 106 first-year nursing students at the University of Huelva, Spain. Methods: Data on social and academic variables and variables relating to the instrumental and expressive roles were collected via an adapted, pilot-tested questionnaire assessed by experts. Results: For participants, caregiving is the core of the nursing role in the clinical setting, including both technical execution and patient care aspects. They highlighted the disease prevention, health promotion, restoration, and education profiles of nurses rather than their teaching, professional, and technical profiles. They were acquainted with the concept of postgraduate professional development, but were unaware of the academic pathways leading to it. They considered nurses to be decision-makers, who are nevertheless subordinate to doctors. Conclusions: Students did not consider nursing to be an autonomous profession, although they highlighted its decision-making capacity. They placed greater emphasis on the traditional profile of primary care nurses than on their technical profile, and were able to identify the members of the multidisciplinary healthcare team.Funding for open access charge: Universidad de Huelva / CBU

Design of a Low-Cost Multiplexer for the Study of the Impact of Soiling on PV Panel Performance

Atmospheric factors, such as clouds, wind, dust, or aerosols, play an important role in the power generation of photovoltaic (PV) plants. Among these factors, soiling has been revealed as one of the most relevant causes diminishing the PV yield, mainly in arid zones or deserts. The effect of soiling on the PV performance can be analyzed by means of I–V curves measured simultaneously on two PV panels: one soiled and the other clean. To this end, two I–V tracers, or one I–V tracer along with a multiplexer, are needed. Unfortunately, these options are usually expensive, and only one I–V tracer is typically available at the site of interest. In this work, the design of a low-cost multiplexer is described. The multiplexer is controlled by a low-cost single-board microcontroller manufactured by ArduinoTM, and is capable of managing several pairs of PV panels almost simultaneously. The multiplexer can be installed outdoors, in contrast to many commercial I–V tracers or multiplexers. This advantage allows the soiling effect to be monitored on two PV panels, by means of I–V indoor tracers. I–V curves measured by the low-cost multiplexer are also presented, and preliminary results are analyzedThis research was funded by the Spanish Ministry of Economy, Industry, and Competitiveness “PVCastSOIL” project No ENE2017-83790-C3-1-2-3-R, in collaboration with the European Regional Development Fun