23 research outputs found

    The 21 cm Signature of Shock Heated and Diffuse Cosmic String Wakes

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    The analysis of the 21 cm signature of cosmic string wakes is extended in several ways. First we consider the constraints on GμG\mu from the absorption signal of shock heated wakes laid down much later than matter radiation equality. Secondly we analyze the signal of diffuse wake, that is those wakes in which there is a baryon overdensity but which have not shock heated. Finally we compare the size of these signals compared to the expected thermal noise per pixel which dominates over the background cosmic gas brightness temperature and find that the cosmic string signal will exceed the thermal noise of an individual pixel in the Square Kilometre Array for string tensions Gμ>2.5×108G\mu > 2.5 \times 10^{-8}.Comment: 10 pages, 4 figures, Appendix added, version published in JCA

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    Educational level, socio-economic status and relationship with quality of life in elderly residents of the city of Porto Alegre/RS, Brazil

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    The objective of this study was to verify the index of quality of life of elderly individuals belonging to groups, from different socioeconomic strata in the city of Porto Alegre, Rio Grande do Sul State. The research adopted a transversal model, used to collect data from the SF-36 questionnaire. The sampling is the intentional type and comprised: 61 elderly people in Class A, 80 in Class C, and 84 in Class E. The research was approved by the Committee of Ethics in Research/UFRGS. In relation to the quality of life, Class A presented higher scores than did Classes C and E on the pain, vitality, social aspect and mental health areas. The results also showed a significant difference in quality of life among university educated individuals versus the other schooling groups, on the pain, vitality, mental health and social aspect fields. Quality of life is a complex concept to study, but essential to improve the perception of health and welfare by the elderly.<br>O objetivo deste trabalho foi verificar o índice de qualidade de vida de idosos participantes de grupos de convivência, de diferentes estratos socioeconômicos do município de Porto Alegre/RS. A pesquisa seguiu um modelo de estudo transversal e utilizou para coleta de dados o questionário SF-36. A amostragem foi do tipo intencional e foi composta por: 61 idosos na classe A, 80 na classe C e de 84 na classe E. A pesquisa foi aprovada pelo Comitê de Ética em Pesquisa da UFRGS. Em relação à qualidade de vida, a classe A apresentou escores melhores que a classe C e E nos domínios dor, vitalidade, aspecto social e saúde mental. Houve diferença significativa de qualidade de vida no ensino superior completo, em relação aos demais estratos de escolaridade, nos domínios dor, vitalidade, saúde mental e aspecto social. A qualidade de vida é um conceito complexo de ser estudado, mas essencial para que haja melhora na percepção de saúde e do bem-estar pelos idosos
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