Differential Tiam1/Rac1 activation in hippocampal and cortical neurons mediates differential spine shrinkage in response to oxygen/glucose deprivation.

Distinct neuronal populations show differential sensitivity to global ischemia, with hippocampal CA1 neurons showing greater vulnerability compared to cortical neurons. The mechanisms that underlie differential vulnerability are unclear, and we hypothesize that intrinsic differences in neuronal cell biology are involved. Dendritic spine morphology changes in response to ischemic insults in vivo, but cell type-specific differences and the molecular mechanisms leading to such morphologic changes are unexplored. To directly compare changes in spine size in response to oxygen/glucose deprivation (OGD) in cortical and hippocampal neurons, we used separate and equivalent cultures of each cell type. We show that cortical neurons exhibit significantly greater spine shrinkage compared to hippocampal neurons. Rac1 is a Rho-family GTPase that regulates the actin cytoskeleton and is involved in spine dynamics. We show that Rac1 and the Rac guanine nucleotide exchange factor (GEF) Tiam1 are differentially activated by OGD in hippocampal and cortical neurons. Hippocampal neurons express more Tiam1 than cortical neurons, and reducing Tiam1 expression in hippocampal neurons by shRNA enhances OGD-induced spine shrinkage. Tiam1 knockdown also reduces hippocampal neuronal vulnerability to OGD. This work defines fundamental differences in signalling pathways that regulate spine morphology in distinct neuronal populations that may have a role in the differential vulnerability to ischemia

The way of life of pluriactivity farmers in Minho villages in Northwest Portugal

Este artigo teve por objetivo analisar o modo de vida do agricultor pluriativo, uma categoria em expansão na agricultura praticada não apenas nas aldeias minhotas do noroeste de Portugal, lócus deste estudo, mas em grande parte do mundo ocidental. Utilizou-se a aplicação de um survey, cross-sectional, aplicado a famílias de agricultores exclusivamente agrícolas e pluriativos, em 50% das freguesias da vila escolhida para este estudo. Os resultados da pesquisa revelaram a urbanização do modo de vida dos agricultores pluriativos e inclusive dos que viviam exclusivamente da agricultura, apontando, contudo, para a compatibilidade da agricultura com este modo de vida mais tecnologizado e integrado à dinâmica das vilas e cidades.This article aimed to analyze the lifestyle of the pluriactive farmer. This is a growing category in the agricultural practices not only held in the Minho villagesin northwestern Portugal, which is the locus for this study, but also vastly found in the eastern world. A cross-sectional survey was conducted, which was applied exclusively to pluriactive, agricultural families, in 50% of the civil parishes of the chosen village. The results of thisresearch made evident the urbanization in the lifestyle of the pluriactive farmer including those who used to live solely of agriculture. However, thisstudy points out to the compatibility of agriculture with a lifestyle that is more technological, more integrated with the village and the city dynamics

Environmental modeling of the intercompartmental distribution of low-level radioactive wastes

The uranium mining in Portugal was active almostduring one century in 62 different sites. One of these sitesrefers to the former Urgeiriça uranium mine, anunderground mine which was considered to be the mostimportant uranium exploitation in the country. Thisformer mine is surrounded by small farms and countryhouses and most of the local population lives in a villagelocated at 2 km from the mine.The Urgeiriça mine was exploited between 1913 and1944 for radium extraction and from 1951 to 1991 for theproduction of uranium concentrates. The ores from thismine, as well as from other uranium mines exploited inPortugal, were processed in the Urgeiriça uranium millfacility. About 2,5 million tones of low level radioactivewastes from this facility were disposed in an open air areaoriginating the largest tailings pile of the mining area,named as the Old Dam, with an average height of 14meters covering 13,3 hectares in this region (Figure1).Fig. 1. Aerial photo of the Urgeiriça Old Dam.Since 1996 the Portuguese government had to dealwith the decommissioning of the mines, mills and otherfacilities and the rehabilitation of the mining sites.In particular, for the remediation of the Urgeiriça site,the reclamation program was announced in 2005. For thissite the rehabilitation of the Old Dam was considered akey element of the overall environmental reclamationprogram [1].Radioactivity measurements done at the Old Damshowed high concentrations for the radionuclides of the238U decay series [2]. It is also well known that thesetailings were a source of external radiation andfurthermore, a powerful source of radon originatinghigher radiation levels comparing to the backgroundvalues. Due to precipitation, water, wind and soil erosion,radionuclides could be transported and redistributed inthis region as well as in its vicinity. Therefore, peopleliving in the nearby areas could be exposed to additionallevels of radiation. This study intended to evaluate theenvironmental impacts from the Old Dam tailingsdisposal to the soil, water, and air

Endocytosis and lysosomal degradation of GluA2/3 AMPARs in response to oxygen/glucose deprivation in hippocampal but not cortical neurons

Abstract Global cerebral ischemia results in oxygen and glucose deprivation (OGD) and consequent delayed cell death of vulnerable neurons, with hippocampal CA1 neurons more vulnerable than cortical neurons. Most AMPA receptors (AMPARs) are heteromeric complexes of subunits GluA1/GluA2 or GluA2/GluA3, and the presence of GluA2 renders AMPARs Ca2+-impermeable. In hippocampal CA1 neurons, OGD causes the synaptic expression of GluA2-lacking Ca2+-permeable AMPARs, contributing to toxic Ca2+ influx. The loss of synaptic GluA2 is caused by rapid trafficking of GluA2-containing AMPARs from the cell surface, followed by a delayed reduction in GluA2 mRNA expression. We show here that OGD causes endocytosis, lysosomal targeting and consequent degradation of GluA2- and GluA3-containing AMPARs, and that PICK1 is required for both OGD-induced GluA2 endocytosis and lysosomal sorting. Our results further suggest that GluA1-containing AMPARs resist OGD-induced endocytosis. OGD does not cause GluA2 endocytosis in cortical neurons, and we show that PICK1 binding to the endocytic adaptor AP2 is enhanced by OGD in hippocampal, but not cortical neurons. We propose that endocytosis of GluA2/3, caused by a hippocampal-specific increase in PICK1-AP2 interactions, followed by PICK1-dependent lysosomal targeting, are critical events in determining changes in AMPAR subunit composition in the response to ischaemia

Experiência de linguagem na escrita de infância.

A Literatura Infantil é, na contemporaneidade, um campo de estudos em ascensão. Sua consolidação no rol dos estudos literários, porém, enfrenta equívocos que remontam à sua própria adjetivação. O termo “infantil”, comumente referido a partir de uma compreensão biopsíquica da infância, é interpretado como caracterizante de algo limitado e inacabado, portanto, de menor valor. Embasado na filosofia de Giorgio Agamben, surge uma nova chave de acesso ao conceito de "infantil” na experiência literária, cujo método está na mediação da própria linguagem. A partir do conceito de “experiência de linguagem”, o infans pode ser reconhecido no centro discursivo do texto, espaço em que ganha presença ao inscrever as qualidades literárias reconhecidas numa poética que não se deixa esgotar pelo estatuto da simbologia. Travessia essa que marca a Literatura de Infância, ao propiciar à criança a presença histórica como linguagem, e consequente poder de 'ser uma voz e ter-lugar no tempo' da enunciação literária. As narrativas exemplares, contos de Carrascoza, apenas nos oferecem o lugar da experiência como um modo de manifestação da "infância" na linguagem escrita, com o objetivo de marcar os limites que separam a língua da fala.PALAVRAS-CHAVE: Literatura Infantil; infância; experiência de linguagem

A CONSTITUIÇÃO DO VIAJANTE TRANSCULTURAL: UM ESTUDO DE FIGURA NA SOMBRA, DE ASSIS BRASIL

The present paper focuses in the study of the novel Figura na sombra of the author, Luiz Antonio de Assis Brasil, in the intention to, beginning by the understanding of the hybrid productions of history and fiction as a critical reading mode, treat the memorial rescue of the biography of the french naturalist, Aimé Bonpland, a figure that remained on the edge of the historical records and that is now renewed by fiction. The possibility of rereading history materialized in a literary work creates multiples visions about the past time and gives personality, origin and voice to this silenced figure, showing us the opportunity to know the past by the anonymous's bias. A traveler and a great research scholar of the American fauna and flora, Bonpland was relegated to shadow and oblivion, as the title implies, who abandoned his own homeland to establish permanently in the South American extreme where he joined to the local customs, language and identity after a long period of wanderings and transits by different Latin-American countries. Thus, the narrative flirt with questions related to the identity formation, transits, crossing borders and transcultural process in which the subject along his journey is renewed in touch, in changes and in relations with distinct cultures highlighting, thereby, a pungent phenomena throughout Latin America.  O presente trabalho centra-se no estudo do romance Figura na Sombra, do escritor Luiz Antonio de Assis Brasil sob o intento de, partindo da compreensão das produções híbridas de história e ficção como modalidade de releitura crítica do, tratar do resgate memorial da biografia do naturalista francês Aimé Bonpland, figura que permaneceu à margem dos registros históricos, mas que agora se renova através da ficção. Essa possibilidade de reler a história materializada na obra literária gera múltiplas visões sobre o tempo pretérito e dá personalidade, origem e voz a essa figura silenciada, apresentando-nos a possibilidade de conhecer o passado pelo viés do anônimo. Viajante e grande estudioso da fauna e da flora americana, Bonpland ficou relegado à sombra e ao esquecimento, assim como o título insinua, abandonando a sua terra natal para estabelecer-se em definitivo no extremo sul-americano, onde integrou-se aos costumes, à língua e à identidade local após um longo período de andanças e trânsitos por diferentes países latino-americanos. A narrativa flerta, portanto, com questões relativas à formação identitária, trânsitos, travessia de fronteiras e processos transculturais em que o sujeito durante a sua jornada se renova no contato, nas trocas e nas relações com diferentes culturas, evidenciando, assim, um fenômeno pungente em toda a América Latina

Coordenação dos Estudos Clínicos de Cardiologia desenvolvidos no Hospital Universitário Walter Cantídio

This research presents discussions on the topic clinical studies, more specifically, under the coordination of cardiology, calling themselves ‘Coordination of Clinical Trials of Cardiology developed at the University Hospital Walter Cantídio’. The overall objective was to understand the perception of users and health professionals on the conduct and develo pment of clinical trials in cardiology at the University Hospital Walter Cantídio. Developed a qualitative research, a case study that used semi-structured interviews as data collection technique. These visibilizaram the voice of 18 patients and six health professionals. The discussion was theoretically supported by authors such as: Arone (2007), Barbosa (1989), Borsoi e Codo (1995), Japiassu e Marcondes (1993), Jansen (1997), Karlberg e Speers (2010), Marziale e Robazzi (2000), among others who have contributed to studies in this area. Research has shown that the physician may be located more authentically withthe patient, treating it more humane way, understanding its limitations and possibilities, although without getting involved with the irrational wish of the patient. It was concluded that the HUWC Clinical studies require greater medical attention in order to provide greater clarification patients about their disease and up the progress of their treatment and experienced improvement.A presente pesquisa apresenta discussões sobre a temática estudos clínicos, mais especificamente, no âmbito da coordenação da área de cardiologia, intitulando-se ’Coordenação dos Estudos Clínicos de Cardiologia desenvolvidos no Hospital Universitário Walter Cantídio‘. O objetivo geral foi compreender a percepção dos usuários e profissionais de saúde sobre a condução e desenvolvimento dos estudos clínicos na área de cardiologia no Hospital Universitário Walter Cantídio. Desenvolveu-se uma pesquisa qualitativa, do tipo estudo de caso, que utilizou entrevistas semiestruturadas como técnica de coleta de dados. Estas visibilizaram a voz de 18 pacientes e seis profissionais de saúde. A discussão dos resultados foi amparada teoricamente em autores como: Arone (2007), Barbosa (1989), Borsoi e Codo (1995), Japiassu e Marcondes (1993), Jansen (1997), Karlberg e Speers (2010), Marziale e Robazzi (2000), dentre outros que já contribuíram com estudos nessa área. A pesquisa mostrou que o médico pode se situar de maneira mais autêntica junto ao doente, tratando-o de forma mais humanizada, entendendo suas limitações e possibilidades, embora sem se envolver com os desígnios irracionais do paciente. Concluiu-se que os Estudos Clínicos do HUWC exigem uma maior atenção do médico no sentido de oferecer aos pacientes maiores esclarecimentos sobre sua doença e sobe a evolução do seu tratamento e melhorias vivenciadas