2,278 research outputs found

    The influence of excessive consumption on residents’ family thriving: the roles of intergenerational poverty transmission and educational cognition

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    Whether excessive consumption triggers the intergenerational transmission of poverty, as well as the role of residents’ cognition in family thriving, is still unclear in the literature. By adopting the structural equation model and the hierarchical regression method, we empirically tested the impact of excessive consumption and intergenerational transmission of poverty on the family thriving. We found that: first, the stronger the excessive consumption of Chinese residents are, the less helpful for them to achieve family thriving; the stronger the intra- and inter-generational transmission of poverty of Chinese residents are, the less likely for them to achieve family thriving. Second, excessive consumption reduces residents’ demands on family thriving by promoting the degree of intra-generational or inter-generational transmission of poverty. Third, the effect of achieving family thriving by reducing the intra- or inter-intergenerational transmission of poverty is evident in highly education-cognitive people. Our research provides insight into how excessive consumption affects the intergenerational transmission of poverty and the family thriving. It also provides valuable decision support for poverty reduction in public sector

    Surveillance of SARS-CoV-2 virus circulation using Acute Respiratory Infections sentinel system of Catalonia (PIDIRAC) during the 2019-2020 season: A retrospective observational study

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    Background: In the context of COVID-19 pandemic in Catalonia (Spain), the present study analyses respiratory samples collected by the primary care network using Acute Respiratory Infections Sentinel Surveillance System (PIDIRAC) during the 2019-2020 season to complement the pandemic surveillance system in place to detect SARS-CoV-2. The aim of the study is to describe whether SARS-CoV-2 was circulating before the first confirmed case was detected in Catalonia, on February 25th, 2020. Methods: The study sample was made up of all samples collected by the PIDIRAC primary care network as part of the Influenza and Acute Respiratory Infections (ARI) surveillance system activities. The study on respiratory virus included coronavirus using multiple RT-PCR assays. All positive samples for human coronavirus were subsequently typed for HKU1, OC43, NL63, 229E. Every respiratory sample was frozen at-80°C and retrospectively studied for SARS-CoV-2 detection. A descriptive study was performed, analysing significant differences among variables related to SARS-CoV- 2 cases comparing with rest of coronaviruses cases through a bivariate study with Chi-squared test and statistical significance at 95%. Results: Between October 2019 and April 2020, 878 respiratory samples from patients with acute respiratory infection or influenza syndrome obtained by PIDIRAC were analysed. 51.9% tested positive for influenza virus, 48.1% for other respiratory viruses. SARS-CoV-2 was present in 6 samples. The first positive SARS-CoV-2 case had symptom onset on 2 March 2020. These 6 cases were 3 men and 3 women, aged between 25 and 50 years old. 67% had risk factors, none had previous travel history nor presented viral coinfection. All of them recovered favourably. Conclusion: Sentinel Surveillance PIDIRAC enhances global epidemiological surveillance by allowing confirmation of viral circulation and describes the epidemiology of generalized community respiratory viruses' transmission in Catalonia. The system can provide an alert signal when identification of a virus is not achieved in order to take adequate preparedness measures

    Effect of parasympathetic stimulation on brain activity during appraisal of fearful expressions

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    Autonomic nervous system activity is an important component of human emotion. Mental processes influence bodily physiology, which in turn feeds back to influence thoughts and feelings. Afferent cardiovascular signals from arterial baroreceptors in the carotid sinuses are processed within the brain and contribute to this two-way communication with the body. These carotid baroreceptors can be stimulated non-invasively by externally applying focal negative pressure bilaterally to the neck. In an experiment combining functional neuroimaging (fMRI) with carotid stimulation in healthy participants, we tested the hypothesis that manipulating afferent cardiovascular signals alters the central processing of emotional information (fearful and neutral facial expressions). Carotid stimulation, compared with sham stimulation, broadly attenuated activity across cortical and brainstem regions. Modulation of emotional processing was apparent as a significant expression-by-stimulation interaction within left amygdala, where responses during appraisal of fearful faces were selectively reduced by carotid stimulation. Moreover, activity reductions within insula, amygdala, and hippocampus correlated with the degree of stimulation-evoked change in the explicit emotional ratings of fearful faces. Across participants, individual differences in autonomic state (heart rate variability, a proxy measure of autonomic balance toward parasympathetic activity) predicted the extent to which carotid stimulation influenced neural (amygdala) responses during appraisal and subjective rating of fearful faces. Together our results provide mechanistic insight into the visceral component of emotion by identifying the neural substrates mediating cardiovascular influences on the processing of fear signals, potentially implicating central baroreflex mechanisms for anxiolytic treatment targets

    The production of hydrogen through the use of a 77 wt% Pd 23 wt% Ag membrane water gas shift reactor

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    Hydrogen as an energy carrier has the potential to decarbonize the energy sector. This work presents the application of a palladium-silver (PdeAg) membrane-based reactor. The membrane reactor which is made from PdeAg film supported by porous stainless steel (PSS) is evaluated for the production of hydrogen and the potential replacement of the current two-stage Water-Gas Shift (WGS) reaction by a single stage reaction. The permeability of a 20 mmPdeAg membrane reactor was examined at 320° C, 380° C and 430° C. The effect of continuous hydrogen exposure on the PdeAg membrane at high temperature and low temperature was examined to investigate the thermal stability and durability of the membrane. During continuous operation to determine thermal stability, the membrane reactor exhibited stable hydrogen permeation at 320° C for 120 h and unstable hydrogen permeation at 430° C was observed. For the WGS reaction, the reactor was loaded with Ferrochrome catalyst. The membrane showed the ability to produce high purity hydrogen, with a CO conversion and an H2 recovery of 84% and 88%, respectively. The membrane suffered from hydrogen embrittlement due to desorption and adsorption of hydrogen on the membrane surface. SEM analysis revealed cracks that occurred on the surface of the membrane after hydrogen exposure. XRD analysis revealed lattice expansion after hydrogen loading which suggests the occurrence of phase change from a-phase to the more brittle b-phase.DHE

    Las representaciones sociales de los docentes, en relación con la incidencia de la enseñanza de idiomas extranjeros en la formación de grado universitario en el ámbito de la Facultad de Humanidades y Ciencias Sociales (FHyCS-UNaM). EIERS 2. 16H314

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    Es continuidad del Proyecto EIERS (16H-254); continuando con el diseño de investigación exploratoria, cuali-cuantitativo, que tiene por objeto relevar las representaciones sociales de los docentes de la FHyCS-UNaM sobre el valor otorgado a la inclusión del aprendizaje de idiomas extranjeros en la formación académica de grado y contrastarlos con las prácticas académicas (programas de cátedras, producciones didácticas e Informes de Investigación, de Avance y Finales, producidos por los docentes de las carreras de grado en estudio y con el Informe Final del proyecto EIERS). La finalidad será construir un corpus crítico entre lo relevado en los discursos y lo que se hace en la praxis en cuanto a la incorporación de la lengua extranjera en los procesos de enseñanzaaprendizaje en la formación de estudiantes universitarios de las carreras de grado de la FHyCSUNaM. Con este proceso de indagación se busca disponer de conocimiento, analizado a partir de datos primarios y fuentes secundarias, para construir criterios de análisis que posibiliten desarrollar acciones críticas sobre el quehacer en la formación universitaria de grado en relación a la adquisición de competencias lingüísticas que posibiliten el acceso a la producción científico académica que se realiza en otros idiomas. En esta segunda etapa el equipo de investigadores se propone explorar la percepción que tienen los docentes sobre los aprendizajes instrumentales de lenguas extranjeras y la valoración que realizan acerca del impacto de estos conocimientos en la habilitación académica de los estudiantes en su formación de grado universitario; como así también en la continuidad de las carreras de postgrado y / en su desarrollo profesional. El análisis de las RSd sobre la importancia de los IE en su formación de grado, brindará información acerca de los modos en que el docente construye el espacio disciplinar en que está inmerso a fin de trazar nuevas y más complejas redes conceptuales, redimensionando sus prácticas áulicas Resumen técnico: Es continuidad del Proyecto EIERS (16H-254); continuando con el diseño de investigación exploratoria, cuali-cuantitativo, que tiene por objeto relevar las representaciones sociales de los docentes de la FHyCS-UNaM sobre el valor otorgado a la inclusión del aprendizaje de idiomas extranjeros en la formación académica de grado y contrastarlos con las prácticas académicas (programas de cátedras, producciones didácticas e Informes de Investigación, de Avance y Finales, producidos por los docentes de las carreras de grado en estudio y con el Informe Final del proyecto EIERS). La finalidad será construir un corpus crítico entre lo relevado en los discursos y lo que se hace en la praxis en cuanto a la incorporación de la lengua extranjera en los procesos de enseñanzaaprendizaje en la formación de estudiantes universitarios de las carreras de grado de la FHyCSUNaM. Con este proceso de indagación se busca disponer de conocimiento, analizado a partir de datos primarios y fuentes secundarias, para construir criterios de análisis que posibiliten desarrollar acciones críticas sobre el quehacer en la formación universitaria de grado en relación a la UNaM – FHCS – SinvyP Gsinvyp03 adquisición de competencias lingüísticas que posibiliten el acceso a la producción científico académica que se realiza en otros idiomas

    Rotating Higher Spin Partition Functions and Extended BMS Symmetries

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    We evaluate one-loop partition functions of higher-spin fields in thermal flat space with angular potentials; this computation is performed in arbitrary space-time dimension, and the result is a simple combination of Poincar\'e characters. We then focus on dimension three, showing that suitable products of one-loop partition functions coincide with vacuum characters of higher-spin asymptotic symmetry algebras at null infinity. These are extensions of the bms_3 algebra that emerges in pure gravity, and we propose a way to build their unitary representations and to compute the associated characters. We also extend our investigations to supergravity and to a class of gauge theories involving higher-spin fermionic fields.Comment: 58 pages; clarifications and references added; version to be published in JHE

    Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials

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    Recent years witnessed a rapid growth of interest of scientific and engineering communities to thermal properties of materials. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range - of over five orders of magnitude - from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. I review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. A special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe prospects of applications of graphene and carbon materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe

    Singular values of the Dirac operator in dense QCD-like theories

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    We study the singular values of the Dirac operator in dense QCD-like theories at zero temperature. The Dirac singular values are real and nonnegative at any nonzero quark density. The scale of their spectrum is set by the diquark condensate, in contrast to the complex Dirac eigenvalues whose scale is set by the chiral condensate at low density and by the BCS gap at high density. We identify three different low-energy effective theories with diquark sources applicable at low, intermediate, and high density, together with their overlapping domains of validity. We derive a number of exact formulas for the Dirac singular values, including Banks-Casher-type relations for the diquark condensate, Smilga-Stern-type relations for the slope of the singular value density, and Leutwyler-Smilga-type sum rules for the inverse singular values. We construct random matrix theories and determine the form of the microscopic spectral correlation functions of the singular values for all nonzero quark densities. We also derive a rigorous index theorem for non-Hermitian Dirac operators. Our results can in principle be tested in lattice simulations.Comment: 3 references added, version published in JHE

    Multijet production in neutral current deep inelastic scattering at HERA and determination of α_{s}

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    Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson virtualities 10 5 GeV and –1 < η_{LAB}^{jet} < 2.5. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant α_{s} (M_{z}), determined from the ratio of the trijet to dijet cross sections, is α_{s} (M_{z}) = 0.1179 ± 0.0013 (stat.)_{-0.0046}^{+0.0028}(exp.)_{-0.0046}^{+0.0028}(th.)
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