69 research outputs found

    Grey and white matter correlates of recent and remote autobiographical memory retrieval:Insights from the dementias

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    The capacity to remember self-referential past events relies on the integrity of a distributed neural network. Controversy exists, however, regarding the involvement of specific brain structures for the retrieval of recently experienced versus more distant events. Here, we explored how characteristic patterns of atrophy in neurodegenerative disorders differentially disrupt remote versus recent autobiographical memory. Eleven behavioural-variant frontotemporal dementia, 10 semantic dementia, 15 Alzheimer's disease patients and 14 healthy older Controls completed the Autobiographical Interview. All patient groups displayed significant remote memory impairments relative to Controls. Similarly, recent period retrieval was significantly compromised in behavioural-variant frontotemporal dementia and Alzheimer's disease, yet semantic dementia patients scored in line with Controls. Voxel-based morphometry and diffusion tensor imaging analyses, for all participants combined, were conducted to investigate grey and white matter correlates of remote and recent autobiographical memory retrieval. Neural correlates common to both recent and remote time periods were identified, including the hippocampus, medial prefrontal, and frontopolar cortices, and the forceps minor and left hippocampal portion of the cingulum bundle. Regions exclusively implicated in each time period were also identified. The integrity of the anterior temporal cortices was related to the retrieval of remote memories, whereas the posterior cingulate cortex emerged as a structure significantly associated with recent autobiographical memory retrieval. This study represents the first investigation of the grey and white matter correlates of remote and recent autobiographical memory retrieval in neurodegenerative disorders. Our findings demonstrate the importance of core brain structures, including the medial prefrontal cortex and hippocampus, irrespective of time period, and point towards the contribution of discrete regions in mediating successful retrieval of distant versus recently experienced events

    Avaliação da alimentação de idosos de município paulista: aplicação do Índice de Alimentação Saudável

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    OBJETIVO: avaliar a qualidade da dieta da população idosa do município de Avaré (SP) através do Índice de Alimentação Saudável (IAS) MÉTODOS: trata-se de um estudo de corte transversal de base populacional realizado por meio de entrevista domiciliar. A amostra constou de 73 indivíduos, sorteados aleatoriamente dos idosos integrados ao Sistema Público de Saúde do Município. O consumo alimentar foi medido por meio de 3 Recordatórios de 24 horas. Para avaliação, foi aplicado o IAS adaptado para a população brasileira. Parte-se do princípio que o presente estudo constitui o primeiro no Brasil a aplicar o IAS utilizando 3 inquéritos do tipo recordatório de 24 horas em população idosa. Optou-se por esta metodologia, pois como descrito na literatura, um único dia não representa a ingestão habitual de um indivíduo devido à elevada variabilidade intrapessoal do consumo. RESULTADOS: Foram encontrados 32,9% de idosos com uma dieta de má qualidade; 60,3% necessitando de melhorias e 6,8% com uma dieta de boa qualidade. CONCLUSÃO: Pode-se concluir que os idosos estudados precisam de melhorias na alimentação, o que ressalta a importância de política de incentivo voltado à alimentação saudável na terceira idade.The scope of this paper was to evaluate the quality of the diet of the elderly in the city of Avaré, São Paulo state, using the Healthy Eating Index (HEI). A cross-sectional population-based study was conducted by home interviews. The sample consisted of 73 individuals, randomly selected among elderly people from the public health system in the city. Food consumption was measured by 3 24-hour recalls. The HEI adapted to the Brazilian population was applied for evaluation purposes. It is believed that this study is the first in Brazil to apply the HEI using 3 surveys of the 24-hour recall type among the elderly population. This methodology was chosen because, as described in the literature, a single day does not accurately reflect the usual intake of an individual due to the high interpersonal variance in consumption. It was found that 32.9% of elderly people were on a poor quality diet, 60.3% needed adjustments and 6.8% had a good quality diet. The conclusion that can be drawn is that the elderly population studied need to improve their diet, which emphasizes the importance of policies geared to encouraging healthy eating in old age.Universidade Estadual de São Paul

    Conservation of Forest Birds: Evidence of a Shifting Baseline in Community Structure

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    Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance.We used North American Breeding Bird Survey data, a time series of Landsat images classified with respect to land cover change, and mixed-effects models to associate changes in forest bird community structure with forest disturbance, latitude, and longitude in the conterminous United States for the years 1985 to 2006. We document a significant divergence from the baseline structure for all birds of similar migratory habit and nest location, and all forest birds as a group from 1985 to 2006. Unexpectedly, decreases in progressive similarity resulted from small changes in richness (<1 species per route for the 22-year study period) and modest losses in abundance (-28.7 - -10.2 individuals per route) that varied by migratory habit and nest location. Forest disturbance increased progressive similarity for Neotropical migrants, permanent residents, ground nesting, and cavity nesting species. We also documented highest progressive similarity in the eastern United States.Contemporary forest bird community structure is changing rapidly over a relatively short period of time (e.g., approximately 22 years). Forest disturbance and forest regeneration are primary factors associated with contemporary forest bird community structure, longitude and latitude are secondary factors, and forest loss is a tertiary factor. Importantly, these findings suggest some regions of the United States may already fall below the habitat amount threshold where fragmentation effects become important predictors of forest bird community structure

    A Single Peroxisomal Targeting Signal Mediates Matrix Protein Import in Diatoms

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    Peroxisomes are single membrane bound compartments. They are thought to be present in almost all eukaryotic cells, although the bulk of our knowledge about peroxisomes has been generated from only a handful of model organisms. Peroxisomal matrix proteins are synthesized cytosolically and posttranslationally imported into the peroxisomal matrix. The import is generally thought to be mediated by two different targeting signals. These are respectively recognized by the two import receptor proteins Pex5 and Pex7, which facilitate transport across the peroxisomal membrane. Here, we show the first in vivo localization studies of peroxisomes in a representative organism of the ecologically relevant group of diatoms using fluorescence and transmission electron microscopy. By expression of various homologous and heterologous fusion proteins we demonstrate that targeting of Phaeodactylum tricornutum peroxisomal matrix proteins is mediated only by PTS1 targeting signals, also for proteins that are in other systems imported via a PTS2 mode of action. Additional in silico analyses suggest this surprising finding may also apply to further diatoms. Our data suggest that loss of the PTS2 peroxisomal import signal is not reserved to Caenorhabditis elegans as a single exception, but has also occurred in evolutionary divergent organisms. Obviously, targeting switching from PTS2 to PTS1 across different major eukaryotic groups might have occurred for different reasons. Thus, our findings question the widespread assumption that import of peroxisomal matrix proteins is generally mediated by two different targeting signals. Our results implicate that there apparently must have been an event causing the loss of one targeting signal even in the group of diatoms. Different possibilities are discussed that indicate multiple reasons for the detected targeting switching from PTS2 to PTS1
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