Revisiting the bound on axion-photon coupling from Globular Clusters

We derive a strong bound on the axion-photon coupling $g_{a\gamma}$ from the analysis of a sample of 39 Galactic Globular Clusters. As recognized long ago, the R parameter, i.e. the number ratio of stars in horizontal over red giant branch of old stellar clusters, would be reduced by the axion production from photon conversions occurring in stellar cores. In this regard we have compared the measured R with state-of-the-art stellar models obtained under different assumptions for $g_{a\gamma}$. We show that the estimated value of $g_{a\gamma}$ substantially depends on the adopted He mass fraction Y, an effect often neglected in previous investigations. Taking as benchmark for our study the most recent determinations of the He abundance in H II regions with O/H in the same range of the Galactic Globular Clusters, we obtain an upper bound $g_{a\gamma}<0.66\times 10^{-10}$ GeV$^{-1}$ at 95$\%$ confidence level. This result significantly improves the constraints from previous analyses and is currently the strongest limit on the axion-photon coupling in a wide mass range.Comment: (v2: 6 pages, 1 eps figure. Revised version. Discussion enlarged and references added. To appear on Physical Review Letters.

Estudio de factibilidad para el montaje y puesta en marcha de una empresa de asesorías y consultorías en proyectos en el municipio de Caucasia

RESUMEN: El siguiente documento contiene un estudio a nivel de factibilidad para el montaje y operación de una empresa de asesoría y consultoría en el municipio de Caucasia, subregión de Bajo Cauca en el departamento de Antioquia. Para la elaboración del estudio se surtieron cada una de las etapas que desde el punto vista metodológico son necesarias para la realización de una evaluación profunda de las alternativas de inversión, las cuales posibilitan la identificación y análisis de variables y factores determinantes del dictamen de viabilidad y la decisión de financiamiento. Como resultado del estudio se pudo establecer que el proyecto es viable a nivel técnico, comercial, legal y administrativo, sin embargo, a nivel financiero el concepto de viabilidad es desfavorable, ya que el resultado de los indicadores financieros (VPN, TIR, B/C) arrojan resultados negativos tanto en el flujo de caja libre como en el flujo de caja del inversionista. En virtud de lo anterior, se concluye que el proyecto debe aplazarse hasta tanto las condiciones del entorno financiero permitan diseñar una estructura financiera en la cual el costo de capital sea favorable a las expectativas de los inversionistas. Pese al concepto desfavorable se espera que el trabajo sea un punto de referencia para futuras investigaciones o proyectos similares. ABSTRACT: The following document contains a feasibility study for the assembly and operation of an advisory and consulting company in the municipality of Caucasia, sub-region of Bajo Cauca in the department of Antioquia. For the preparation of the study, each of the stages that from the methodological point of view are necessary for the realization of an in-depth evaluation of the investment alternatives were provided, which allow the identification and analysis of variables and determining factors of the feasibility and the financing decision. As a result of the study, it was possible to establish that the project is viable at a technical, commercial, legal and administrative level, however, at a financial level the concept of feasibility is unfavorable, since the result of the financial indicators (NPV, IRR, B/C) show negative results in both the free cash flow and the investor’s cash flow. By virtue of the above, it is concluded that the project should be postponed until the conditions of the financial environment allow the design of a financial structure in which the cost of capital is favorable to the expectations of investors. Despite the unfavorable concept, it is expected that the work will be a reference point for future research or similar projects

Mechanical properties and structural behaviour of masonry at elevated temperatures

The variation in the compressive strength of concrete block masonry was studied at elevated temperatures. Small specimens known as wallettes were used to obtain the compressive strength under steady state conditions. Eighteen wallettes were made of lightweight concrete blocks and 1:1:5 mortar proportion. The target temperatures were 20°C, 200°C, 400°C, 600°C, 700°C and 800°C. Initially load-deflection relationships were determined from the experimental wallettes and later they were converted into stress-strain relationships. Although the goal was to determine the compressive strength, other parameters were also studied such as modulus of elasticity, temperature-time relationships, modes of failure, material degradation, and change of colour.Lightweight concrete blocks were also tested to determine the compressive strength at equal temperatures applied for the wallettes. The blocks belonged to the same batch used for the wallettes. The tensile behaviour of mortar was determined at 20°C, 200°C and 400°C.Once the mechanical properties of the masonry wallettes, units and mortar were determined, they were used as input data to develop finite element models to simulate the same behaviour of the experimental wallettes. Finally, using the experimental and numerical results from the wallettes, they were used to predict the behaviour of 3m height walls.EThOS - Electronic Theses Online ServiceCONACYTGBUnited Kingdo

Impacto del financiamiento del Programa Reactiva Perú en la liquidez de la empresa TYPLAST S.A.C., Lurigancho, 2020

La presente investigación tiene como objetivo general analizar el impacto del financiamiento del Programa Reactiva Perú en la liquidez de la empresa TYPLAST S.A.C. del año 2020. La metodología usada es de método mixto, tipo básica con diseño no experimental y nivel descriptivo. La población y muestra, estuvo constituido por los documentos del Programa Reactiva Perú, el balance general y estado de flujo de caja de la empresa TYPLAST S.A.C. correspondientes al 2019, 2020 y 2021. Para la recopilación de datos se aplicó entrevista y análisis documental, de igual manera se obtuvo una beneficiosa liquidez durante los últimos trimestres del 2020 y mejorando poco a poco durante el 2021, por último, la diferencia restante lo uso para capital de trabajo. Como conclusión se obtuvo que el financiamiento del Programa Reactiva Perú tiene un impacto positivo en la liquidez de la empresa TYPLAST S.A.C en el año 2020, ya que se demostró que el financiamiento otorgado por este programa apoyó a la empresa a confrontar sus obligaciones a corto plazo con sus proveedores principales, de igual forma ayudó a enfrentar las obligaciones con sus trabajadores (remuneraciones)

Sistema de detección de estados de ánimo para el diagnóstico de pacientes con ansiedad y depresión utilizando técnicas de reconocimiento facial

Se mejoró la experiencia y toma de pruebas psicológicas, implementado un sistema a base de técnicas de predicción y reconocimiento facial a base de las emociones. Con este proyecto brindamos un mejor análisis y diagnóstico de los pacientes, creando un sistema de software que mejora el tiempo de análisis y los resultados obtenidos al realizar la evaluación psicológica, logrando un resultado más confiable, además de llevar un control e historial de los pacientes. Los resultados de la muestra de este proyecto se tomaron a pacientes con problemas de ansiedad y lo monitorearon paralelo un especialista del área de psicología para validar el resultado esperado frente a cada prueba en contra de su diagnóstico basado en tu experticia. Cumpliendo con los objetivos específicos y el objetivo general planteado en el proyecto, obteniendo un resultado de aceptación sobre el sistema de un 80.26%.We improved the experience and taking of psychological tests, implementing a system based on predictive techniques and facial recognition based on emotions. With this project we provide a better analysis and diagnosis of patients, creating a software system that, using the afore mentioned tools, improves the analysis time and the results obtained when performing the psychological evaluation, achieving a more reliable result, in addition to keeping a control and history of patients. The results obtained in the sample of the present project were taken from patients with anxiety problems and was monitored in parallel by a specialist in the area of psychology in order to validate the expected result against each test against your diagnosis based on your expertise. Fulfilling the specific objectives and the general objective set out in the project, obtaining a result of acceptance on the system of 80.26%.Tesi

Tolerancia a la salinidad del pasto Banderita [Bouteluoa curtipendula (Michx.) Torr.] en la etapa de germinación en dos regímenes de temperaturas

El pasto Banderita es un forraje nativo de México, con gran potencial socio-económico para la ganadería extensiva; sin embargo, la información sobre su tolerancia a la salinidad es escasa. Para evaluar el efecto de diferentes sales y concentraciones sobre su germinación, se utilizaron cariópsides de reciente cosecha. Las salinidades sulfático-sódica y NaHCO3 de pH alcalino, registraron el menor porcentaje de germinación, en las sales: clorhídrica y CaCl2.2H2O con pH ácido, el mayor valor. El efecto de sales combinadas fue benéfico para la germinación; ésta es inversamente proporcional al incremento de solución salina. Un incremento de temperatura favoreció la germinación, disminuyó la toxicidad de los cloruros y permitió que las semillas soportaran mayores concentraciones de salinidad.El pasto Banderita es un forraje nativo de México, con gran potencial socioeconómico para la ganadería extensiva; sin embargo, la información sobre su tolerancia a la salinidad es escasa. Para evaluar el efecto de diferentes sales y concentraciones sobre su germinación, se utilizaron cariópsides de reciente cosecha. Las salinidades sulfáticosódica y NaHCO3 de pH alcalino, registraron el menor porcentaje de germinación, en las sales: clorhídrica y CaCl2 . 2H2O con pH ácido, el mayor valor. El efecto de sales combinadas fue benéÀco para la germinación; ésta es inversamente proporcional al incremento de solución salina. Un incremento de temperatura favoreció la germinación, disminuyó la toxicidad de los cloruros y permitió que las semillas soportaran mayores concentraciones de salinidad

Efecto de la salinidad y la temperatura sobre el crecimiento del pasto Banderita [Bouteluoa curtipendula (Michx.) Torr.]

Para analizar la respuesta del crecimiento de pasto Banderita a la salinidad se diseñó un experimento bifactorial de 11 tipos de sales a 8 concentraciones (0, 2, 4, 8, 12, 15, 19 y 28 dS m-1) y dos temperaturas (19 + 4 y 20 ºC), durante 15 días. Las sales que permitieron el mayor crecimiento fueron CaCl2.2H2O y clorhídrico-sulfática; el NaHCO3 y la salinidad sulfática registraron el menor crecimiento. Las sales geoquímicas permitieron el desarrollo vegetativo mayor en comparación con las sales puras. El crecimiento disminuyó al incrementarse la conductividad eléctrica de la sal. El desarrollo de la radícula fue menor al de la parte aérea tanto a temperatura ambiente como a temperatura controlada.Para analizar la respuesta del crecimiento de pasto Banderita a la salinidad se diseñó un experimento bifactorial de 11 tipos de sales a 8 concentraciones (0, 2, 4, 8, 12, 15, 19 y 28 dS m-1) y dos temperaturas (19 + 4 y 20 ºC), durante 15 días. Las sales que permitieron el mayor crecimiento fueron CaCl2.2H2O y clorhídrico-sulfática; el NaHCO3 y la salinidad sulfática registraron el menor crecimiento. Las sales geoquímicas permitieron el desarrollo vegetativo mayor en comparación con las sales puras. El crecimiento disminuyó al incrementarse la conductividad eléctrica de la sal. El desarrollo de la radícula fue menor al de la parte aérea tanto a temperatura ambiente como a temperatura controlada

Examining Emailed Feedback as Boosters After a College Drinking Intervention Among Fraternities and Sororities: Rationale and Protocol for a Remote Controlled Trial (Project Greek)

BACKGROUND: College students involved in Greek life (ie, members of fraternities and sororities) tend to engage in more high-risk alcohol use and experience more negative consequences than those not involved in Greek life. Web-based alcohol interventions, such as Alcohol eCHECKUP TO GO, have been successful in reducing alcohol use and consequences among the general college student population, but interventions targeting alcohol reduction among those involved in Greek life have had limited success. Booster emails including personalized feedback regarding descriptive norms and protective behavioral strategies have shown potential in increasing the effectiveness of web-based interventions among college drinkers. Studies are needed to determine the efficacy of these boosters among those involved in Greek life. OBJECTIVE: The primary objective of this study is to assess the efficacy of booster emails sent to Greek life students who complete Alcohol eCHECKUP TO GO. Specifically, we expect that participants who receive the booster emails will reduce their alcohol consumption and related problems (primary aim 1), reduce perceived peer drinking, and increase the number of protective behavioral strategies they use over time (primary aim 2) relative to those who do not receive boosters. Contingent upon finding the emailed booster efficacious and sufficient enrollment of members from each organization, an exploratory aim is to examine social mechanisms of change (ie, through selection vs socialization). METHODS: This study is a remote, controlled intervention trial following participants for up to 6 months. Participants must be aged at least 18 years, undergraduate students, and members of a participating fraternity or sorority. Eligible participants complete a web-based baseline survey to assess their alcohol consumption behaviors and beliefs, including norms and protective behavioral strategies, and information about their social networks. After completing the baseline survey, they participate in the web-based intervention. Follow-up surveys are sent 1, 3, and 6 months after the intervention. Those in the booster condition also receive emails containing personalized feedback at 2 weeks and 14 weeks after the intervention. Latent growth models and R-Simulation Investigation for Empirical Network Analysis will be used to analyze the data. RESULTS: As of September 2022, we have enrolled 18 participants from 2 fraternities and 2 sororities, and they have completed the baseline survey. Overall, 72% (13/18) of participants have completed the 1-month follow-up. Enrollment will continue through December 2022. CONCLUSIONS: This study aims to examine the effectiveness of personalized feedback booster emails sent after an alcohol intervention among members of college Greek life. A secondary, exploratory aim is to provide information about social mechanisms of change (if possible). The current methodology targets whole network recruitment, with chapter presidents serving as gatekeepers and facilitators. Unique challenges of recruiting whole networks and working with campus administrators are discussed. TRIAL REGISTRATION: ClinicalTrials.gov NCT05107284; https://clinicaltrials.gov/ct2/show/NCT05107284. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/42535

Event-Related Potentials to an English/Spanish Syllabic Contrast in Mexican 10–13-Month-Old Infants

We report brain electrophysiological responses from 10- to 13-month-old Mexican infants while listening to native and foreign CV-syllable contrasts differing in Voice Onset Time (VOT). All infants showed normal auditory event-related potential (ERP) components. Our analyses showed ERP evidence that Mexican infants are capable of discriminating their native sounds as well as the acoustically salient (aspiration) foreign contrast. The study showed that experience with native language influences VOT perception in Spanish learning infants. The acoustic salience of aspiration is perceived by both Spanish and English learning infants, but exposure provides additional phonetic status to this native-language feature for English learning infants. The effects of early experience and neural commitment as well as the impact of acoustic salience are further discussed