60 research outputs found
Tourism and indigenous heritage in Latin America: as observed through Mexico’s magical village Cuetzalan: Book Review
Deformed Sine-Gordon Models, Solitons and Anomalous Charges
We study certain deformations of the integrable sine-Gordon model (DSG). It is found analytically and numerically several towers of infinite number of anomalous charges for soliton solutions possessing a special space–time symmetry. Moreover, it is uncovered exact conserved charges associated to two-solitons with a definite parity under space-reflection symmetry, i.e. kink-kink (odd parity) and kink-antikink (even parity) scatterings with equal and opposite velocities. Moreover, we provide a linear formulation of the modified SG model and a related tower of infinite number of exact non-local conservation laws. We back up our results with extensive numerical simulations for kink-kink, kink-antikink and breather configurations of the Bazeia et al. potential Vqw=64q2tan2w21−sinw2q2,q∈R, which contains the usual SG potential V2w=21−cos2w
Identifying factors associated with sedentary time after stroke. Secondary analysis of pooled data from nine primary studies.
<p><b>Background</b>: High levels of sedentary time increases the risk of cardiovascular disease, including recurrent stroke.</p> <p><b>Objective</b>: This study aimed to identify factors associated with high sedentary time in community-dwelling people with stroke.</p> <p><b>Methods</b>: For this data pooling study, authors of published and ongoing trials that collected sedentary time data, using the activPAL monitor, in community-dwelling people with stroke were invited to contribute their raw data. The data was reprocessed, algorithms were created to identify sleep-wake time and determine the percentage of waking hours spent sedentary. We explored demographic and stroke-related factors associated with total sedentary time and time in uninterrupted sedentary bouts using unique, both univariable and multivariable, regression analyses.</p> <p><b>Results</b>: The 274 included participants were from Australia, Canada, and the United Kingdom, and spent, on average, 69% (SD 12.4) of their waking hours sedentary. Of the demographic and stroke-related factors, slower walking speeds were significantly and independently associated with a higher percentage of waking hours spent sedentary (p = 0.001) and uninterrupted sedentary bouts of <i>>30</i> and <i>>60 min</i> (p = 0.001 and p = 0.004, respectively). Regression models explained 11–19% of the variance in total sedentary time and time in prolonged sedentary bouts.</p> <p><b>Conclusion</b>: We found that variability in sedentary time of people with stroke was largely unaccounted for by demographic and stroke-related variables. Behavioral and environmental factors are likely to play an important role in sedentary behavior after stroke. Further work is required to develop and test effective interventions to address sedentary behavior after stroke.</p
Avaliação do uso do ciclo de inquérito em escolas rurais da Bolívia
Between the years 2000 and 2005, teachers from 39 schools of the municipality of Coroico (Bolivia) applied a research method called the Inquiry Cycle (IC) in their classrooms. In order to know the effect, in students and teachers, of the application of IC in the skills to design an investigation in the changes in knowledge about the natural environment and in the ability to think critically about the environment itself, a quantitative short-term evaluation was applied in the year 2005. Additionally, to assess whether experiences with IC were stored in the long-term memory, a survey was applied in the year 2017 to a group of 47 youngsters who had applied IC as children. The results indicate that the frequent application of IC improves knowledge and understanding of the natural environment and the ability to reflect on the environment. This is kept in the long term, at least in part of those involved. We conclude that IC is a very valuable tool for the teaching of science linked mainly to environmental conservation.Entre los años 2000 a 2005, maestros de 39 escuelas del municipio de Coroico (Bolivia) aplicaron con sus estudiantes un método de investigación llamado Ciclo de Indagación (CI). Con el objetivo de conocer el efecto, en estudiantes y maestros, de la aplicación del CI en las habilidades para diseñar una investigación, en los cambios en el conocimiento sobre el entorno natural y en la capacidad de pensar críticamente sobre el propio entorno, se aplicó en el año 2005 una evaluación cuantitativa a mediano plazo. Adicionalmente, para evaluar si las experiencias con el CI se almacenaron en la memoria a largo plazo, se realizó en el año 2017 una encuesta a un grupo de 47 jóvenes que aplicaron el CI cuando eran niños. Los resultados indican que la aplicación frecuente del CI mejora el conocimiento y comprensión del entorno natural y la capacidad de reflexionar acerca del ambiente. Esto se mantiene en el largo plazo, al menos en una parte de los involucrados. Concluimos que el CI es una herramienta muy valiosa para la enseñanza de la ciencia vinculada principalmente con la conservación ambiental. Entre 2000 e 2005, professores de 39 escolas do município de Coroico (Bolívia) aplicaram com seus alunos um método de pesquisa chamado Ciclo de Inquérito (CI). Com o objetivo de conhecer o efeito em alunos e professores da aplicação do CI nas habilidades para desenhar uma investigação, nas mudanças no conhecimento sobre o entorno natural e na capacidade de pensar criticamente sobre o próprio entorno, foi aplicado em 2005 um questionário quantitativo a médio prazo. Adicionalmente, para avaliar se as experiências com CI foram armazenadas na memória de longo prazo, foi feito um questionário a um grupo de 47 jovens com os quais se aplicou CI quando crianças. Os resultados indicam que a aplicação frequente de CI melhora o conhecimento e a compreensão do ambiente do entorno natural, bem como a capacidade de refletir sobre esse ambiente. Isso é mantido a longo prazo, ao menos em parte dos envolvidos. Concluímos que o CI é uma ferramenta muito valiosa para o ensino da ciência ligada principalmente à conservação ambiental
Multi-Omics and Pathway analyses of Genome-Wide associations Implicate Regulation and Immunity in Verbal Declarative Memory Performance
BACKGROUND: Uncovering the functional relevance underlying verbal declarative memory (VDM) genome-wide association study (GWAS) results may facilitate the development of interventions to reduce age-related memory decline and dementia.
METHODS: We performed multi-omics and pathway enrichment analyses of paragraph (PAR-dr) and word list (WL-dr) delayed recall GWAS from 29,076 older non-demented individuals of European descent. We assessed the relationship between single-variant associations and expression quantitative trait loci (eQTLs) in 44 tissues and methylation quantitative trait loci (meQTLs) in the hippocampus. We determined the relationship between gene associations and transcript levels in 53 tissues, annotation as immune genes, and regulation by transcription factors (TFs) and microRNAs. to identify significant pathways, gene set enrichment was tested in each cohort and meta-analyzed across cohorts. Analyses of differential expression in brain tissues were conducted for pathway component genes.
RESULTS: The single-variant associations of VDM showed significant linkage disequilibrium (LD) with eQTLs across all tissues and meQTLs within the hippocampus. Stronger WL-dr gene associations correlated with reduced expression in four brain tissues, including the hippocampus. More robust PAR-dr and/or WL-dr gene associations were intricately linked with immunity and were influenced by 31 TFs and 2 microRNAs. Six pathways, including type I diabetes, exhibited significant associations with both PAR-dr and WL-dr. These pathways included fifteen MHC genes intricately linked to VDM performance, showing diverse expression patterns based on cognitive status in brain tissues.
CONCLUSIONS: VDM genetic associations influence expression regulation via eQTLs and meQTLs. The involvement of TFs, microRNAs, MHC genes, and immune-related pathways contributes to VDM performance in older individuals
GWAS analysis of handgrip and lower body strength in older adults in the CHARGE consortium
Decline in muscle strength with aging is an important predictor of health trajectory in the elderly. Several factors, including genetics, are proposed contributors to variability in muscle strength. To identify genetic contributors to muscle strength, a meta-analysis of genomewide association studies of handgrip was conducted. Grip strength was measured using a handheld dynamometer in 27 581 individuals of European descent over 65 years of age from 14 cohort studies. Genomewide association analysis was conducted on ~2.7 million imputed and genotyped variants (SNPs). Replication of the most significant findings was conducted using data from 6393 individuals from three cohorts. GWAS of lower body strength was also characterized in a subset of cohorts. Two genomewide significant (P-value< 5 × 10−8) and 39 suggestive (P-value< 5 × 10−5) associations were observed from meta-analysis of the discovery cohorts. After meta-analysis with replication cohorts, genomewide significant association was observed for rs752045 on chromosome 8 (β = 0.47, SE = 0.08, P-value = 5.20 × 10−10). This SNP is mapped to an intergenic region and is located within an accessible chromatin region (DNase hypersensitivity site) in skeletal muscle myotubes differentiated from the human skeletal muscle myoblasts cell line. This locus alters a binding motif of the CCAAT/enhancer-binding protein-β (CEBPB) that is implicated in muscle repair mechanisms. GWAS of lower body strength did not yield significant results. A common genetic variant in a chromosomal region that regulates myotube differentiation and muscle repair may contribute to variability in grip strength in the elderly. Further studies are needed to uncover the mechanisms that link this genetic variant with muscle strength
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