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Hietarinta Chern–Simons supergravity and its asymptotic structure
Get PDFIn this paper we present the Hietarinta Chern–Simons supergravity theory in three space-time dimensions which extends the simplest Poincaré supergravity theory. After approaching the construction of the action using the Chern–Simons formalism, the analysis of the corresponding asymptotic symmetry algebra is considered. For this purpose, we first propose a consistent set of asymptotic boundary conditions for the aforementioned supergravity theory whose underlying symmetry corresponds to the supersymmetric extension of the Hietarinta algebra. We then show that the corresponding charge algebra contains the superbms3 algebra as subalgebra, and has three independent central charges. We also show that the obtained asymptotic symmetry algebra can alternatively be recovered as a vanishing cosmological constant limit of three copies of the Virasoro algebra, one of which is augmented by supersymmetry
Sound pressure level in the speech signal due to the use of a mask or face shield
Get PDFIntroducción: El uso de mascarillas y escudos faciales se generalizó durante la pandemia de COVID-19, pero su impacto en la salud vocal, especialmente en quienes usan la voz como herramienta de trabajo, aún no está completamente estudiado. Este estudio investiga el efecto de diferentes tipos de mascarillas y escudos faciales en el nivel de presión sonora de la voz, con especial atención al riesgo de desarrollar patologías vocales.
Métodos: Se realizaron grabaciones de voz a 18 participantes (11 mujeres y 7 hombres) en una cabina audiométrica, midiendo el nivel de presión sonora continuo equivalente (Leq) con un sonómetro. Se compararon los resultados obtenidos con diferentes tipos de mascarillas (quirúrgica, KN95, con ventana transparente) y un escudo facial.
Resultados: No se encontraron diferencias significativas en el Leq entre los grupos con y sin elementos de protección. Sin embargo, se observó que las mujeres tienden a aumentar la intensidad de su voz al usar mascarillas o escudos faciales, lo que podría generar un mayor esfuerzo vocal y un riesgo potencial de desarrollar patologías vocales a largo plazo.
Conclusiones: Si bien el uso de mascarillas y escudos faciales es necesario en ciertos contextos, es importante considerar las posibles consecuencias para la salud vocal, especialmente en mujeres. Se recomienda el uso de lenguaje no verbal para complementar la comunicación y evitar la combinación de mascarillas KN95 con escudos faciales cuando no sea estrictamente necesario
Uncovering the role of the subcommissural organ in early brain development through transcriptomic analysis
Get PDFBackground
The significant role of embryonic cerebrospinal fluid (eCSF) in the initial stages of brain development has been thoroughly studied. This fluid contains crucial molecules for proper brain development such as members of the Wnt and FGF families, apolipoproteins, and retinol binding protein. Nevertheless, the source of these molecules remains uncertain since they are present before the formation of the choroid plexus, which is conventionally known as the primary producer of cerebrospinal fluid. The subcommissural organ (SCO) is a highly conserved gland located in the diencephalon and is one of the earliest differentiating brain structures. The SCO secretes molecules into the eCSF, prior to the differentiation of the choroid plexus, playing a pivotal role in the homeostasis and dynamics of this fluid. One of the key molecules secreted by the SCO is SCO-spondin, a protein involved in maintenance of the normal ventricle size, straight spinal axis, neurogenesis, and axonal guidance. Furthermore, SCO secretes transthyretin and basic fibroblast growth factor 2, while other identified molecules in the eCSF could potentially be secreted by the SCO. Additionally, various transcription factors have been identified in the SCO. However, the precise mechanisms involved in the early SCO development are not fully understood.
Results
To uncover key molecular players and signaling pathways involved in the role of the SCO during brain development, we conducted a transcriptomic analysis comparing the embryonic chick SCO at HH23 and HH30 stages (4 and 7 days respectively). Additionally, a public transcriptomic data from HH30 entire chick brain was used to compare expression levels between SCO and whole brain transcriptome. These analyses revealed that, at both stages, the SCO differentially expresses several members of bone morphogenic proteins, Wnt and fibroblast growth factors families, diverse proteins involved in axonal guidance, neurogenic and differentiative molecules, cell receptors and transcription factors. The secretory pathway is particularly upregulated at stage HH30 while the proliferative pathway is increased at stage HH23.
Conclusión
The results suggest that the SCO has the capacity to secrete several morphogenic molecules to the eCSF prior to the development of other structures, such as the choroid plexus
Basis for high order divergence-free finite element spaces
No full textA method classically used in the lower polynomial degree for the construction of a finite element basis of the space of divergence-free functions is here extended to any polynomial degree for a bounded domain without topological restrictions. The method uses graphs associated with two differential operators: the gradient and the divergence, and selects the basis using a spanning tree of the first graph. It can be applied for the two main families of degrees of freedom, weights and moments, used to express finite element differential forms
Star-spot activity, orbital obliquity, transmission spectrum, physical properties, and transit time variations of the HATS-2 planetary system
Get PDFAims. Our aim in this paper is to refine the orbital and physical parameters of the HATS-2 planetary system and study transit timing variations and atmospheric composition thanks to transit observations that span more than 10 yr and that were collected using different instruments and pass-band filters. We also investigate the orbital alignment of the system by studying the anomalies in the transit light curves induced by starspots on the photosphere of the parent star.
Methods. We analysed new transit events from both ground-based telescopes and NASA’s TESS mission. Anomalies were detected in most of the light curves and modelled as starspots occulted by the planet during transit events. We fitted the clean and symmetric light curves with the JKTEBOP code and those affected by anomalies with the PRISM+GEMC codes to simultaneously model the photometric parameters of the transits and the position, size, and contrast of each starspot.
Results. We found consistency between the values we found for the physical and orbital parameters and those from the discovery paper and ATLAS9 stellar atmospherical models. We identified different sets of consecutive starspot-crossing events that temporally occurred in less than five days. Under the hypothesis that we are dealing with the same starspots, occulted twice by the planet during two consecutive transits, we estimated the rotational period of the parent star and, in turn the projected and the true orbital obliquity of the planet. We find that the system is well aligned. We identified the possible presence of transit timing variations in the system, which can be caused by tidal orbital decay, and we derived a low-resolution transmission spectrum
Advancing teacher reflective competence: Integrating lesson study and didactic suitability criteria in training
Get PDFThis study examines the impact of combining Lesson Study and the Didactic Suitability Criteria (DSC) for the development of teacher reflective skills. It involves six teachers in an Argentinean training program, spanning 15 virtual sessions over 5 months. Analysis of video recordings indicates significant improvement in reflective abilities, especially when using the DSC for lesson analysis. This approach enhances teaching quality and benefits student learning. The study suggests Lesson Study and the DSC are valuable tools for promoting collaboration and reflection among educators, particularly in math education. Further research with larger samples and long-term follow-up is recommended. This underscores the importance of integrating Lesson Study and the DSC in teacher training to enhance reflective competence and raise education quality
Experiências formativas em engenharia baseadas em metodologias ativas: Uma revisão sistemática da literatura
Get PDFEl plan de estudio de las carreras de ingeniería considera una formación en ciencias básicas y ciencias de la ingeniería. Por lo que este análisis aborda las investigaciones que implementan metodologías activas para la enseñanza de la ingeniería como construcción de una experiencia formativa. La información recolectada en las bases de datos Web of Science, Scopus y SciELO, bajo el modelo PRISMA de revisión sistemática de la literatura, analizó las metodologías activas, instrumentos de evaluación y su enfoque e impactos curriculares. Se obtuvo una muestra de 646 artículos, de los cuales, debido a la aplicación de criterios de inclusión y exclusión, fueron seleccionados únicamente 85. Las investigaciones se centran en asignaturas relacionadas a las ciencias de la ingeniería mediadas por aprendizaje cooperativo y aprendizaje basado en proyectos; además, se utilizan técnicas de recolección de datos basadas en cuestionarios y encuestas focalizadas en la experiencia de la innovación. Los impactos de las decisiones pedagógicas están centrados en el rendimiento académico y la adquisición de contenidos. En conclusión, la configuración que se establece entre el objeto de enseñanza y los sujetos es mediada por experiencias de aprendizaje en las que interactúan el currículum, la didáctica y la evaluación. Esto le permite al estudiantado mapear una experiencia formativa que apunta hacia la subjetivación, es decir, a reconstruir su visión del mundo tanto a nivel personal como profesional
Shannon entropy variation as a global indicator of electron density contraction at interatomic regions in chemical reactions
No full textContext: The negative of the Shannon entropy derivative is proposed to account for electron density contraction as the chemical bonds are breaking and forming during a chemical reaction. We called this property the electron density contraction index, EDC, which allows identifying stages in a reaction that are dominated by electron contraction or expansion. Four diferent reactions were analyzed to show how the EDC index changes along the reaction coordinate. The results indicate that the rate of change of Shannon entropy is directly related to the rate of change of the electron density at the bond critical points between all the atomic pairs in the molecular systems. It is expected that EDC will complement the detailed analysis of reaction mechanisms that can be performed with the theoretical tools available to date.
Methods: Density functional theory calculations at the B3LYP/6-31G(d,p) level of theory were carried out using Gaussian 16 to analyze the reaction mechanisms of the four reactions studied. The reaction paths were obtained via the intrinsic reaction coordinate method, which served as the reaction coordinate to obtain the reaction force and the EDC profles in each case. Shannon entropy and electron density at the bond critical points were calculated using the Multiwfn 3.7 package
Evolution of the ecological niche behind the largest disjunct freshwater fish distribution in the world
No full text1. Ecological processes that are behind distributions of species that inhabit isolated localities, complex disjunct distributions, remain poorly understood. Traditionally, vicariance and dispersion have been proposed as explanatory mechanisms that drive such distributions. However, to date, our understanding of the ecological processes driving evolution of ecological niches associated with disjunct distributions remains rudimentary.
2. Here, we propose a framework to deconstruct drivers of such distribution using World's most widespread freshwater fish Galaxias maculatus as a model and integrating marine and freshwater environments where its life cycle may occur. Specifically, we assessed ecological and historical factors (Gondwanan vicariance, marine dispersion) and potential dispersion (niche‐tracking) that explain its distribution in the Southern Hemisphere.
3. Estimated distribution was consistent with previously reported distribution and mainly driven by temperature and topography in freshwater environments and by primary productivity and nitrate in marine environments. Niche dynamics of G. maculatus provided evidence of synergy between vicariance and marine dispersion as explanatory mechanisms of its disjunct distribution, suggesting that its ecological niche was conserved since approximately 30 Ma ago.
4. This integrated assessment of ecological niche in marine and freshwater environments serves as a generic framework that may be applied to understand processes underpinning complex distributions of diadromous species
Empoderamiento de la mujer: Un panorama general a través del análisis bibliométrico
Get PDFEl Empoderamiento de la Mujer (WfEM) es esencial para lograr la igualdad de género y el desarrollo sostenible. El objetivo de este estudio es presentar un panorama general sobre el WfEM mediante el análisis bibliométrico. Se utiliza el método del análisis de desempeño e indicadores como el h-index, la productividad y la citas. Posteriormente, se aplica el método del mapeo científico utilizando el software Vosviewer® para mostrar la imagen del campo del WfEM con las técnicas de citas conjuntas y la co-ocurrencia de palabras claves. Este estudio utiliza la base de datos SCOPUS. Las unidades de análisis fueron artículos y autores. Los resultados muestran que los autores más influyentes en el campo son Naila Kabeer, Agnes R. Quisumbing, Kathryn Yount, Sidney Ruth Schuler y Syed Mesbahuddin Hashemi. El WfEM es un campo de proyección mundial, con gran número de áreas emergentes debido a la visibilidad de participación de las mujeres, dominios, enfoques teóricos y capacidad estratégica de desarrollo. El género, la igualdad de género, país-India, microfinanzas y desarrollo son temas que mantienen una estrecha relación con el WfEM. Sin embargo, el concepto presenta desafíos en su análisis y medición, además del riesgo de perder sus bases políticas, emancipadoras y de justicia social