1,570 research outputs found

    Aportaciones a los estudios económico-administrativos. Reflexiones teóricas y evidencias empíricas

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    La economía y la administración están inmersas en el universo de las ciencias sociales, áreas del conocimiento que comprenden dominios diferentes, pero también convergen y se intersectan en un objeto de estudio: las organizacienones y sus agregados (industrias o sectores). Desde una perspectiva social, los estudios económico-administrativos informan sobre cómo hacer eficientes a las organizaciones y competitivos a los sectores con la finalidad de impactar positivamente en la justicia social (por ejemplo: mediante productos de mejor calidad a mejores precios). El auge de este tipo de estudios está extendido a fenómenos clave en el mundo de hoy, tales como: la ventaja competitiva, la innovación, la administración de la cadena de suministros y la administración verde, entre otros.El objetivo de este libro es difundir las aportaciones hechas a los estudios económico-administrativos, ya sea como reflexiones teóricas o a modo de evidencia empírica, pues la conjunción de varias ciencias ayuda a comprender fenómenos complejos mejor que una disciplina en forma aislada. Más que la homogeneidad de teorías o hegemonía de unas sobre otras, la investigación interdisciplinaria construye un acercamiento a la diversidad de puntos de vista: se buscan factores, métodos o lenguajes comunes alrededor de un objeto de estudio (Fernández, 2009; Martínez, 1997), llegándose a conformar una comunidad científica con antecedentes disciplinarios diferentes, pero con cierta unidad, relaciones y acciones recíprocas (Kuhn, 1995). Así, en este texto el objeto de estudio es el funcionamiento e interacción de las organizaciones, como integrantes de los sectores económicos, en los mercados locales y globales. La comunidad científica está conformada por investigadores y egresados del Doctorado en Ciencias Económico-Administrativas, el cual nace en 2006 en la Universidad Autónoma del Estado de México, a cargo de la Dependencia de Educación Superior (DES) Económico-Administrativa

    All Roads Lead to Rome: Results of Non-Invasive Respiratory Therapies Applied in a Tertiary-Care Hospital Without an Intermediate Care Unit During the COVID-19 Pandemic

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    Introducción. Las terapias respiratorias no invasivas (TRNI) fueron ampliamente utilizadas en la primera ola de la pandemia de COVID-19, en escenarios distintos según los medios disponibles. El objetivo fue presentar la supervivencia a 90 días y los factores asociados a esta de los pacientes tratados con TRNI en un centro de tercer nivel sin Unidad de Cuidados Respiratorios Intermedios. Como objetivo secundario comparar los resultados obtenidos de las distintas terapias. Métodos. Estudio observacional de pacientes tratados con TRNI fuera de un ambiente de Cuidados Intensivos o Unidad de Cuidados Respiratorios Intermedios, diagnosticados de COVID-19 y con síndrome de distrés respiratorio agudo por criterios radiológicos y de ratio SpO2/FiO2. Se desarrolló un modelo multivariante de regresión logística para determinar las variables independientemente asociadas, y se compararon los resultados de la terapia de alto flujo con cánula nasal y la presión positiva continua en la vía aérea. Resultados. Se trataron 107 pacientes y sobrevivieron 85 (79,4%) a los 90 días. Antes de iniciar la TRNI el ratio medio de SpO2/FiO2 fue de 119,8±59,4. Un mayor score de SOFA se asoció significativamente a la mortalidad (OR 2,09; IC95% 1,34 – 3,27), mientras que la autopronación fue un factor protector (OR 0,23; IC95% 0,06 – 0,91). La terapia de alto flujo con cánula nasal fue utilizada en 63 sujetos (58,9%), y la presión positiva continua en la vía aérea en 41 (38,3%). No se encontraron diferencias entre ellas. Conclusión. Aproximadamente cuatro de cada cinco pacientes tratados con TRNI sobrevivieron a los 90 días, y no se encontraron diferencias significativas entre la terapia de alto flujo con cánula nasal y la presión positiva continua en la vía aérea.S

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

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    Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

    Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

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    There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

    Search for anomalous couplings in boosted WW/WZ -> l nu q(q)over-bar production in proton-proton collisions at root s=8TeV

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    Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

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    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

    Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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    An embedding technique to determine ττ backgrounds in proton-proton collision data

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    An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe
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