260 research outputs found

    Roots migration: The post-return experiences of second-generation Venezuelan-Portuguese migrants

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    Luso-Venezuelan ‘returnees’ have been moving from Venezuela to Madeira since the 1990s. In recent years, they have arrived in masses, as a result of the ongoing crisis that hit the country after the severe global crash in oil prices. This study focuses on ‘roots migration’, specifically on the experiences of second-generation ‘returnees’ from Venezuela to Madeira, as an important part of the historic phenomenon of emigration from Portugal to Venezuela that started in the 1940s, with a clear majority departing from Madeira island. Drawing on fieldwork based on semi-directed interviews, the aim is to understand the circumstances in which the decision to relocate to Madeira takes place, and how the migration experience develops upon return. Taking into consideration and highlighting these individuals’ upbringing as children of well-integrated immigrants, we look at the way these migrants negotiate their identities and belonging, and how their constructions of the self and home influence their expectations and lived experience in the ancestral homeland.‘Retornados’ Luso-Venezuelanos têm chegado à Madeira vindos da Venezuela, desde a década de 1990, e nos últimos anos, têm chegado em números significativos, como resultado da atual crise que o país tem atravessado desde a grave quebra global dos preços do petróleo. Este estudo centra-se na 'migração em busca de raízes', nomeadamente nas experiências dos filhos dos imigrantes Madeirenses na Venezuela, no âmbito do fenómeno histórico da emigração Portuguesa para a Venezuela que se iniciou nos anos 1940, e cuja maioria era oriunda da ilha da Madeira. A partir de um trabalho de campo centrado em entrevistas semi-diretivas, pretende-se compreender as circunstâncias em que surge a decisão de relocação para a Madeira, e como se desenvolve a experiência migratória após a chegada. Tendo em consideração que os indivíduos em questão são filhos de imigrantes bem integrados no país de acolhimento, analisamos a maneira como estes negociam a sua identidade e sentimentos de pertença, que por sua vez influenciam as expetativas criadas e posteriormente as experiências vivenciadas no país de origem dos pais

    Transduction of an immortalized olfactory ensheathing glia cell line with the green fluorescent protein (GFP) gene: Evaluation of its neuroregenerative capacity as a proof of concept.

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    Olfactory ensheathing glia (OEG) cells are known to foster axonal regeneration of central nervous system (CNS) neurons. Several lines of reversibly immortalized human OEG (ihOEG) have been previously established that enabled to develop models for their validation in vitro and in vivo. In this work, a constitutively GFP-expressing ihOEG cell line was obtained, and named Ts14-GFP. Ts14-GFP neuroregenerative ability was similar to that found for the parental line Ts14 and it can be assayed using in vivo transplantation experimental paradigms, after spinal cord or optic nerve damage. Additionally, we have engineered a low-regenerative ihOEG line, hTL2, using lentiviral transduction of the large T antigen from SV40 virus, denominated from now on Ts12. Ts12 can be used as a low regeneration control in these experiments.pre-print281 K

    A data-driven health assessment method for electromechanical actuation systems

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    The design of health assessment applications for the electromechanical actuation system of the aircraft is a challenging task. Physics-of-failure models involve non-linear complex equations which are further complicated at the system-level. Data-driven techniques require run-to-failure tests to predict the remaining useful life. However, components are not allowed to run until failure in the aerospace engineering arena. Besides, when adding new monitoring elements for an improved health assessment, the airliner sets constraints due to the increased cost and weight. In this context, the health assessment of the electromechanical actuation system is a challenging task. In this paper we propose a data-driven approach which estimates the health state of the system without run-to-failure data and limited health information. The approach combines basic reliability theory with Bayesian concepts and obtained results show the feasibility of the technique for asset health assessment

    Development of an aeronautical electromechanical actuator with real time health monitoring capability

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    Development and implementation of EMAs has increased rapidly during the last years in the context of the “more electrical aircraft”. One of the main technical key issues for the EMA implementation is the jamming. It can appear due to metalmetal contact of load transmission (in gearboxes, bearings and ball/roller screws). This problem penalizes the reliability although with very low failure rate. To overcome this problem in aeronautical EMAs are actually several ways investigated, where one of the most attractive and with more promising is the implementation of advanced monitoring systems. This implementation of “smart” monitoring systems will imply a clear economical profit in the final product and in the complete system: envisaged benefits will be lower maintenance costs with higher reliability, instead of increasing maintenance costs and decreasing reliability for classical components without Health Monitoring. At the end, the selection of the Health Monitoring and Management system will be able to establish different levels of validation: failure detection, diagnostic and prognostic; this will provide a proactive maintenance strategy in order to replace EMA before failure. A demonstrator prototype of an innovative electromechanical actuator with real time health monitoring capability has been designed and developed by SENER. This actuator type can be taken as a reference for typical secondary control surface applications. This development is based on previous work performed by SENER in AWIATOR project where one of the tasks was the design and calculation of the new flap trailing edge with MINITEDs. In addition, this work included the supports and linkages of the current actuator to the MINITED. This compact electromechanical actuator shows innovations with respect to current state-of-the-art electrical actuators as lightness and compactness of the resulting actuator, with high power density within small dimensions. As an added value, an additional plug module is under development for real time health monitoring to detect potential working incidents: “smart actuator”. One of the additional key points will be the health management in order to solve the introduction of these systems in EMAs, and to check the compatibility with the aircraft systems

    Consequences of the Lack of IL-10 in Different Endotoxin Effects and its Relationship With Glucocorticoids

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    Sepsis constitutes one of the major causes of death in ICUs. In sepsis induced by gram-negative, although lipopolysaccharide (LPS) initially induces an exacerbated secretion of proinflammatory cytokines leading to endotoxic shock and death resembling a septic shock, it is also capable of inducing refractoriness to subsequent challenge with LPS, a state known as endotoxin tolerance, which is considered the initial step of the immunosuppression found in septic patients. As we previously demonstrated the importance of glucocorticoids in endotoxin tolerance, the aim of this study was to evaluate the contribution of Interleukin-10 (IL-10) both in the endotoxic shock and in the development of the tolerance and its relationship with glucocorticoids. Our results show that, upon LPS challenge, IL-10 knockout mice (KO) mice had an enhanced LPS sensitivity, along with elevated levels of proinflammatory cytokines as tumor necrosis factor-α, IL-12 and interferon-γ, and enhanced tissue damage, despite the high levels of glucocorticoids. This effect may be because, in part, of the higher expression of tumor necrosis factor receptors in IL-10 KO mice. Further, the injection of dexamethasone did not protect IL-10 KO mice from a LPS lethal challenge. Although tolerance was achieved in the absence of IL-10, it was weaker and the elevated levels of glucocorticoids were not able to reverse the high sensitivity of IL-10 KO mice to LPS. Nevertheless, glucocorticoids would play a pivotal role in the establishment and maintenance of this partial tolerance in IL-10 KO mice. Finally, our results show that IL-10 and glucocorticoids could act in a bidirectional way influencing the inflammatory and anti-inflammatory periods.Fil: Córdoba Moreno, Marlina Olyissa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Todero, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fontanals, Adriana Mirta. Fundación Instituto Leloir; ArgentinaFil: Pineda, Gonzalo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Montagna, Daniela Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Yokobori, Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Ramos, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Barrientos, Gabriela Laura. Hospital Alemán. Laboratorio de Medicina Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Toblli, Jorge Eduardo. Hospital Alemán. Laboratorio de Medicina Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Isturiz, Martín Amadeo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Rearte, María Bárbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

    Activation of innate and specific immune responses in hemolytic uremic syndrome (HUS)- patients

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    La función primaria del sistema inmunológico es preservar al individuo sano frente a infinidad de agentes microbianos patógenos o injuriantes. Sin embargo, en determinadas circunstancias los mecanismos agresores normalmente montados contra un agente invasor, pueden tornarse altamente injuriantes para el propio individuo. Hay importantes evidencias tanto clínicas como experimentales, de que la reacción inflamatoria inducida por los distintos componentes de las bacterias Escherichia coli productoras de toxina Shiga (Stx) (STEC), fundamentalmente la Stx y los lipopolisacáridos (LPS), contribuye decisivamente en la evolución a la forma completa de SUH Así los pacientes al ser diagnosticados de SUH, presentan evidencias de haber sufrido un proceso de activación del sistema inmune innato, o reacción inflamatoria muy aguda y temprana en la evolución de la enfermedad. Algunas de estas evidencias pueden resumirse como: una neutrofilia marcada, leucocitos neutrófilos (PMN) circulantes que se encuentran “agotados o exhaustos”, los monocitos diferenciados hacia un fenotipo inflamatorio (menor expresión de CD14 y aumento de CD16), y se encuentra un significativo descenso en los leucocitos que presentan el receptor para la quimioquina Fractalquina (FKN, CX3CL1)) (CX3CR1): los. monocitos clásicos y células Natural Killer (NK). Estas células tienen un alto potencial citotóxico. La FKN se expresa en endotelio y epitelio renal y ha sido involucrada en los mecanismos patogénicos en distintas nefropatías. Llamativamente, encontramos una correlación significativa entre la severidad del cuadro renal y las alteraciones mencionadas. Por último se discute el papel protector que la respuesta inmune específica podría ejercer, fundamentalmente a través de la producción de anticuerpos neutralizantes de la Stx.The central role of the immune system is the preservation of the health against several pathogenic microbes and injury agents. However, on special conditions defensive mechanisms triggered towards the foreign agent can damage the host. Clinical and experimental evidence indicate that inflammatory reaction triggered by the main components of Shiga toxin (Stx)- producing Escherichia coli (STEC), participate in the evolution to the complete form of HUS. When children are diagnosed of HUS, they present evidence that have suffered a very strong and early inflammatory response. These features include: the presence of a marked neutrophilia, the polymorfonuclear leucocytes (PMN) are “deactivated or exhausted” and the monocytes are differentiated towards an inflammatory phenotype (CD14-reduced and CD16-enhanced membrane expression). In addition, HUS-patients show a marked reduction in the absolute and relative number of leucocytes carrying the receptor (CX3CR1) for the chemokine “Fractalkine” (FKN, CX3 CL1), which are the classic monocytes and Natural Killer cells (NK). All these cells express a high cytotoxic potencial. The chemokine FKN is expressed in endothelial and epithelial renal cells, and is involved in the pathogenic mechanism of different nephropathies. Noteworthy, we found a significant correlation between the severity of the renal damage (as days of anuria) and the alterations described above. Finally, the protective role of specific immune response, mainly through the antibody production with Stx-neutralizing capacity, is discussed.Fil: Palermo, Marina Sandra. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fernandez, Gabriela C.. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Ramos, Maria Victoria. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Bentancor, Leticia. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Fernández Brando, Romina Jimena. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Dran, Graciela I.. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Isturiz, Martín Amadeo. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

    Olfactory ensheathing cell-conditioned medium reverts 3 Ab25–35-induced oxidative damage in SH-SY5Y cells 4 by modulating the mitochondria-mediated apoptotic pathway.

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    Olfactory ensheathing cells (OECs) are a type of 10 glia from the mammalian olfactory system, with neuro- 11 protective and regenerative properties. b-Amyloid peptides 12 are a major component of the senile plaques characteristic 13 of the Alzheimer brain. The amyloid beta (Ab) precursor 14 protein is cleaved to amyloid peptides, and Ab25–35 is 15 regarded to be the functional domain of Ab, responsible for 16 its neurotoxic properties. It has been reported that Ab25–35 17 triggers reactive oxygen species (ROS)-mediated oxidative 18 damage, altering the structure and function of mitochon- 19 dria, leading to the activation of the mitochondrial intrinsic 20 apoptotic pathway. Our goal is to investigate the effects of 21 OECs on the toxicity of aggregated Ab25–35, in human 22 neuroblastoma SH-SY5Y cells. For such purpose, SH- 23 SY5Y cells were incubated with Ab25–35 and OEC-conditioned medium (OECCM). OECCM promoted the 24 cell viability and reduced the apoptosis, and decreased the 25 intracellular ROS and the lipid peroxidation. In the pres- 26 ence of OECCM, mRNA and protein levels of antioxidant 27 enzymes (SOD1 and SOD2) were upregulated. Concomi- 28 tantly, OECCM decreased mRNA and the protein expres- 29 sion levels of cytochrome c, caspase-9, caspase-3, and Bax 30 in SH-SY5Y cells, and increased mRNA and the protein 31 expression level of Bcl-2. However, OECCM did not alter 32 intracellular Ca 33 2? concentration in SH-SY5Y cells. Taken together, our data suggest that OECCM ameliorates 34 Ab25–35-induced oxidative damage in neuroblastoma SH- 35 SY5Y cells by inhibiting the mitochondrial intrinsic path- 36 way. These data provide new insights into the functional 37 actions of OECCM on oxidative stress-induced cell 38 damage.pre-print2138 K
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