169 research outputs found
"Resonance" phenomena in thermal diffusion processes in two-layer structures
The dependence on chopper frequency of the effective thermal diffusivity and
effective thermal conductivity in photoacoustic experiments is discussed. The
theoretical model of a two-layer structure at rear-surface illumination in the
high frequency limit is considered. It is shown that the effective thermal
diffusivity presents ``resonance'' while the effective thermal conductivity
sharply changes its magnitude and sign. Such ``resonant'' behavior strongly
depends on the surface thermal conductivities associated with the interface
thermal contacts.Comment: 13 pages, 3 figure
3D printed scaled setup for smoke transport analysis in a subterranean passenger platform
In this work, the study of smoke fire transportation inside of a subway passenger platform is presented. The study includes a set of numerical simulations to observe the behavior of the smoke inside the platform. Two smoke transport simulations using the FDS program are also included. Subsequently, the development of a 3D - 1:100 scale model is described and it was used to perform an experimental observation of the phenomenon. The model was built by using a 3D printer which allowed to include more architectural details of the real scenario. The inclusion of these details allowed to observe qualitative similarity between the results of the simulation and the experimental work. Although there are clear differences between what could happen in a real scenario and what was observed in the scale model, it was identified that the model is an important complement to the simulations. In addition to the simulations, the use of this type of 3D models allows the observation of the phenomenon by different specialists such as firefighters, policeman, medical personnel, etc., in the same place and its intention is to provide a more interactive tool to the observation group, increasing the time devoted to the development of contingency actions and reducing the costs associated with the logistics of a real simulacrum. The model allows to better identify the strengths, opportunities, weaknesses and threats of the contingency procedures developed by the safety and hygiene groups and to make their corresponding adjustments if necessary.Peer Reviewe
Cognitive Decline in a Colombian Kindred With Autosomal Dominant Alzheimer Disease: A Retrospective Cohort Study
Data from an autosomal dominant Alzheimer disease (ADAD) kindred were used to track the longitudinal trajectory of cognitive decline associated with preclinical ADAD and explore factors that may modify the rate of cognitive decline
Diagnóstico del clima organizacional desde la perspectiva del docente en la Facultad de Ciencias Agrotecnológicas
La investigación tuvo como objetivo evaluar el clima organizacional en la Facultad de Ciencias Agrotecnológicas de la Universidad Autónoma de Chihuahua y a partir de éste se determina el nombre del proyecto: Diagnóstico del clima organizacional desde la perspectiva de los docentes de la Facultad de Ciencias Agrotecnológicas. Este trabajo pretende refrescar un estudio investigativo sobre el clima organizacional que se realizó anteriormente en la Facultad. La combinación de experiencia, práctica, ideas y conocimientos teóricos brindan el soporte necesario para construir y proponer procesos de intervención que establezcan un panorama real y un mejoramiento continuo al clima organizacional encontrado en la Facultad. La investigación es de tipo descriptivo cuantitativo en la modalidad de campo. El total de encuestas realizadas fue de 32
Professional quality of life and organizational changes: a five-year observational study in Primary Care
<p>Abstract</p> <p>Background</p> <p>The satisfaction and the quality of life perceived by professionals have implications for the performance of health organizations. We have assessed the variations in professional quality of life (PQL) and their explanatory factors during a services management decentralization process.</p> <p>Methods</p> <p>It was designed as a longitudinal analytical observational study in a Health Area in Madrid, Spain. Three surveys were sent out during an ongoing management decentralization process between 2001 and 2005. The professionals surveyed were divided into three groups: Group I (97.3% physicians), group II (92.5% nurses) and group III (auxiliary personnel). Analysis of the tendency and elaboration of an explanatory multivariate model was made. The PQL -35 questionnaire, based on Karasek's demand-control theory, was used to measure PQL. This questionnaire recognizes three PQL dimensions: management support (MS), workload (WL) and intrinsic motivation (IM).</p> <p>Results</p> <p>1444 responses were analyzed. PQL increased 0.16 (CI 95% 0.04 – 0.28) points in each survey. Group II presents over time a higher PQL score than group I of 0.38 (IC 95% 0.18 – 0.59) points. There is no difference between groups I and III.</p> <p>For each point that MS increases, PQL increases between 0.44 and 0.59 points. PQL decreases an average of between 0.35 and 0.49 point, for each point that WL increases.</p> <p>Age appears to have a marginal association with PQL (CI 95% 0.00 – 0.02), as it occurs with being single or not having a stable relationship (CI 95% 0.01 – 0.41). Performing management tasks currently or in the past is related to poorer PQL perception (CI 95% -0.45 – -0.06), and the same occurs with working other than morning shifts (CI 95% -0.03 – -0.40 points).</p> <p>PQL is not related to sex, location of the centre (rural/urban), time spent working in the organization or contractual situation.</p> <p>Conclusion</p> <p>With the improvement in work control and avoiding increases in workloads, PQL perception can be maintained despite deep organizational changes at the macro-management level. Different professional groups experience different perceptions depending on how the changes impact their position in the organization.</p
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Cell type-specific genetic regulation of gene expression across human tissues
The Genotype-Tissue Expression (GTEx) project has identified expression and splicing quantitative trait loci in cis (QTLs) for the majority of genes across a wide range of human tissues. However, the functional characterization of these QTLs has been limited by the heterogeneous cellular composition of GTEx tissue samples. We mapped interactions between computational estimates of cell type abundance and genotype to identify cell type-interaction QTLs for seven cell types and show that cell type-interaction expression QTLs (eQTLs) provide finer resolution to tissue specificity than bulk tissue cis-eQTLs. Analyses of genetic associations with 87 complex traits show a contribution from cell type-interaction QTLs and enables the discovery of hundreds of previously unidentified colocalized loci that are masked in bulk tissue
The impact of sex on gene expression across human tissues
Many complex human phenotypes exhibit sex-differentiated characteristics. However, the molecular mechanisms underlying these differences remain largely unknown. We generated a catalog of sex differences in gene expression and in the genetic regulation of gene expression across 44 human tissue sources surveyed by the Genotype-Tissue Expression project (GTEx, v8 release). We demonstrate that sex influences gene expression levels and cellular composition of tissue samples across the human body. A total of 37% of all genes exhibit sex-biased expression in at least one tissue. We identify cis expression quantitative trait loci (eQTLs) with sex-differentiated effects and characterize their cellular origin. By integrating sex-biased eQTLs with genome-wide association study data, we identify 58 gene-trait associations that are driven by genetic regulation of gene expression in a single sex. These findings provide an extensive characterization of sex differences in the human transcriptome and its genetic regulation
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The impact of sex on gene expression across human tissues
Many complex human phenotypes exhibit sex-differentiated characteristics, however the underlying molecular mechanisms of these differences remain largely unknown. Here, we present an extensive catalog of both sex differences in gene expression and its genetic regulation across 44 human tissue sources surveyed by GTEx (v8 release). We demonstrate that sex strongly influences gene expression levels and cellular composition of tissue samples across the human body. The effect of sex on gene expression is widespread, with a total of 37% of all genes exhibiting sex-biased expression in at least one tissue. This suggests that many if not most biological processes, and thus complex traits and diseases, are impacted by sex effects on the transciptome. We expand the identification of cis-eQTLs with sex-differentiated effects and characterize their cellular origin. By integrating sex-biased eQTLs with genome-wide association study data, we identify 58 gene-trait associations that are driven by genetic regulation in a single sex, including novel associations not detected with sex-agnostic approaches. Altogether we provide the most comprehensive characterization of sex differences in the human transcriptome and its regulation to date.Peer ReviewedPreprin
Yeasts associated with the production of distilled alcoholic beverages
Distilled alcoholic beverages are produced firstly by fermenting sugars emanating from cereal starches (in the case of whiskies), sucrose-rich plants (in the case of rums), fructooligosaccharide-rich plants (in the case of tequila) or from fruits (in the case of brandies). Traditionally, such fermentations were conducted in a spontaneous fashion, relying on indigenous microbiota, including wild yeasts. In modern practices, selected strains of Saccharomyces cerevisiae are employed to produce high levels of ethanol together with numerous secondary metabolites (eg. higher alcohols, esters, carbonyls etc.) which greatly influence the final flavour and aroma characteristics of spirits following distillation of the fermented wash. Therefore, distillers, like winemakers, must carefully choose their yeast strain which will be very important in providing the alcohol content and the sensory profiles of spirit beverages. This Chapter discusses yeast and fermentation aspects associated with the production of selected distilled spirits and highlights similarities and differences with the production of wine
MEGARA developments at LICA-UCM
LICA-UCM is the brand new laboratory for scientific advanced instrumentation (Laboratorio de Investigacion Cientifica Avanzada) at Universidad Complutense de Madrid where MEGARA integration will take place
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