276 research outputs found
Impacto de la pizarra luminosa en estudiantes de contaduría pública de estadística inferencial y fundamentos de matemáticas.
Diagnosticar el uso de la pizarra luminosa en cursos cuantitativos.El uso de recursos que inviten al estudiante a estar más comprometido con su proceso educativo puede incrementar su desempeño. El objetivo del estudio es encontrar el nivel de apreciación percibido en el uso de la pizarra luminosa en dos cursos cuantitativos y establecer las diferencias entre el sexo y la situación laboral de los estudiantes participantes. Se utilizó como instrumento una encuesta que diligenciaron los 97 participantes. Se encontró que el 82% de los estudiantes preferían los videos elaborados por el mismo profesor que orientaba la asignatura, el 82% prefirió verle la cara al profesor mientras escribe en el tablero. En las 3 dimensiones, comprensión, compromiso y satisfacción, se obtuvo 97%, 94% y 95% respectivamente en la categoría “Totalmente de acuerdo”. La apreciación total en relación con el sexo no presentó diferencias significativas, al igual que con la situación laboral
Implicaciones en la salud de los trabajadores originadas por la exposición térmica en cultivos
The health effects related to heat have a high impact on the farming population because it is their only work environment where they can acquire serious illnesses and even death, for which these workers have developed mitigation strategies to improve their conditions labor. Objective: Determine the implications for workers’ health caused by thermal exposure cultures are. Methods: A systematic review in different scientific databases and data were collected in an array in Excel for further analysis data was performed. Results: Temperatures were taken directly 14.6% above 35°C, however, most indirect measurements were performed in a qualitatively and 65.9% of which are related to the thermal perception of workers. The skin lesions were 34.1% of all reported health effects and the main mitigation measure used by farmers is hydration with water with 31.7% of the articles reviewed. Conclusion: Exposure to high temperatures has implications on the health of workers who may become severe enough to cause cancerous skin lesions, burns, heat stroke and even death. However, many workers have adopted strategies to counter the effects of sun exposure on agricultural crops.Los efectos en la salud relacionados con calor tienen un alto impacto en la población agricultora debido a que es su único entorno de trabajo, donde pueden adquirir graves enfermedades e incluso la muerte, para lo cual éstos trabajadores han ideado estrategias de mitigación que mejoren sus condiciones laborales. Objetivo: Determinar cuáles son las implicaciones en la salud de los trabajadores originadas por la exposición térmica en cultivos. Métodos: Se realizó una revisión sistemática en diferentes bases de datos científicas y los datos se recolectaron en una matriz en Excel para su posterior análisis. Resultados: Las temperaturas tomadas de manera directa fueron de 14.6% por encima de 35° C, sin embargo, la mayoría de las mediciones se realizaron de manera indirecta y cualitativa en un 65.9% las cuales están relacionadas con la percepción térmica de los trabajadores. Las lesiones en la piel fueron el 34.1% de todos los efectos a la salud reportados y la principal medida de mitigación que usan los agricultores es la hidratación con agua con el 31.7% del total de los artículos revisados. Conclusión: La exposición a temperaturas altas genera implicaciones en la salud de los trabajadores que pueden llegar a ser tan graves como para ocasionar lesiones cancerígenas en la piel, quemaduras, golpe de calor y hasta la muerte. Sin embargo, muchos de los trabajadores han adoptado estrategias para contrarrestar los efectos de la exposición solar en los cultivos agrícolas
Incremental Fermi Large Area Telescope fourth source catalog
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMWe present an incremental version (4FGL-DR3, for Data Release 3) of the fourth Fermi Large Area Telescope (LAT) catalog of 3-ray sources. Based on the first 12 years of science data in the energy range from 50 MeV to 1 TeV, it contains 6658 sources. The analysis improves on that used for the 4FGL catalog over eight years of data: more sources are fit with curved spectra, we introduce a more robust spectral parameterization for pulsars, and we extend the spectral points to 1 TeV. The spectral parameters, spectral energy distributions, and associations are updated for all sources. Light curves are rebuilt for all sources with 1 yr intervals (not 2 month intervals). Among the 5064 original 4FGL sources, 16 were deleted, 112 are formally below the detection threshold over 12 yr (but are kept in the list), while 74 are newly associated, 10 have an improved association, and seven associations were withdrawn. Pulsars are split explicitly between young and millisecond pulsars. Pulsars and binaries newly detected in LAT sources, as well as more than 100 newly classified blazars, are reported. We add three extended sources and 1607 new point sources, mostly just above the detection threshold, among which eight are considered identified, and 699 have a plausible counterpart at other wavelengths. We discuss the degree-scale residuals to the global sky model and clusters of soft unassociated point sources close to the Galactic plane, which are possibly related to limitations of the interstellar emission model and missing extended source
Assessing the Gap between Social and Individual Perceptions of Sexual Harassment
Sexual harassment in and out of the workplace has social and economic implications for both the harassed and those subject to the environment. Understanding the nature of sexual harassment perceptions is an important step in designing effective policies aimed at its elimination. This study estimates the gaps between individual and social perceptions of sexual harassment and examines the role of gender in perception gaps in this context. This is accomplished through a laboratory experiment in order to use an incentivized method to elicit the social norm perceptions for sexual harassment scenarios of different types that could be considered in the “gray area”. We find that a gap between individual and social perceptions occurs when accounting for gender but is not present when gender is not accounted for. This occurs because we find that men and women tend to have opposite perception gaps. Under the assumption that perceived social norms influence behavior, our findings suggest that it could be beneficial to design campaigns that consider the role of gender on perceptions of sexual harassment
Lipofundin-Induced Hyperlipidemia Promotes Oxidative Stress and Atherosclerotic Lesions in New Zealand White Rabbits
Atherosclerosis represents a major cause of death in the world. It is known that Lipofundin 20% induces atherosclerotic lesions in rabbits, but its effects on serum lipids behaviour and redox environment have not been addressed. In this study, New Zealand rabbits were treated with 2 mL/kg of Lipofundin for 8 days. Then, redox biomarkers and serum lipids were determined spectrophotometrically. On the other hand, the development of atherosclerotic lesions was confirmed by eosin/hematoxylin staining and electron microscopy. At the end of the experiment, total cholesterol, triglycerides, cholesterol-LDL, and cholesterol-HDL levels were significantly increased. Also, a high index of biomolecules damage, a disruption of both enzymatic and nonenzymatic defenses, and a reduction of nitric oxide were observed. Our data demonstrated that Lipofundin 20% induces hyperlipidemia, which promotes an oxidative stress state. Due to the importance of these phenomena as risk factors for atherogenesis, we suggest that Lipofundin induces atherosclerosis mainly through these mechanisms
Ruteo multicast mediante algoritmos genéticos
Los sistemas o redes de comunicación construidos teniendo en cuenta el modelo de referencia OSI (Open Systems lnterconection) o la arquitectura de Internet, fueron diseñados para soportar servicios o comunicaciones punto a punto, donde la información fluye entre dos usuarios únicamente.
Uno de los tópicos en el cual las redes de computadoras actuales están poniendo mucho énfasis, proviene de las aplicaciones multicast o de grupo. Estas involucran más de dos usuarios (estos usuarios definen el grupo multicast) los cuales desean intercambiar información.
Recientes avances en los medios de transmisión como la fibra óptica y en los equipos como ruutas o switch es, han logrado velocidades del orden de Gbps (Giga Bits por Segundo). Lo anterior sumado al trabajo en las nuevas tecnologías para almacenar datos, audio y video, han permitido el desarrollo de nuevas aplicaciones multimediales y/o servicios de tiempo real distribuidos, como por ejemplo Educación a Distancia, Video-Conferencia, entre otros, donde la red debería ser capaz de proveer el servicio de comunicación multicast.Eje: Sistemas inteligentes. Metaheurísticas.Red de Universidades con Carreras en Informática (RedUNCI
Co-Regulation of Expression of Phase II Metabolizing Enzymes and Multidrug Resistance-Associated Protein 2
Treatment of experimental animals with prototypical enzyme inducers represents a useful tool to characterize the role of different isozymes in drug metabolism and to improve our knowledge on factors regulating their synthesis at the transcriptional level. The effect of model enzyme inducers on phase II (conjugating) enzyme families, including UDP-glucuronosyltransferase’s and glutathione-S-transferase’s, has been well characterized in rodent liver. More recently, the effect of inducers on the expression of canalicular multidrug resistance-associated protein 2 (Mrp2) has been focused upon. The identification of a number of conjugated drugs as Mrp2 substrates suggests that both the conjugation and transport systems act coordinately to improve drug elimination from the body. We provide evidence about circumstances resulting in the simultaneous upregulation of phase II enzymes and Mrp2 in hepatic and extrahepatic tissues, most likely involving activation of common nuclear receptors (e.g., FXR, PXR). Additionally, we provide an analysis of examples of drug-induced toxicity leading to the simultaneous downregulation of both systems. Potential therapeutic strategies based on the modulation of expression of these systems are also briefly commented upon
Stable inversion clines in a grasshopper species group despite complex geographical history
Chromosomal inversions are known to play roles in adaptation and differentiation in many species. They involve clusters of correlated genes (i.e., loci in linkage disequilibrium, LD) possibly associated with environmental variables. The grasshopper "species complex" Trimerotropis pallidipennis comprises several genetic lineages distributed from North to South America in arid and semi-arid high-altitude environments. The southernmost lineage, Trimerotropis sp., segregates for four to seven putative inversions that display clinal variation, possibly through adaptation to temperate environments. We analysed chromosomal, mitochondrial and genome-wide single nucleotide polymorphism data in 19 Trimerotropis sp. populations mainly distributed along two altitudinal gradients (MS and Ju). Populations across Argentina comprise two main chromosomally and genetically differentiated lineages: one distributed across the southernmost border of the "Andes Centrales," adding evidence for a differentiation hotspot in this area; and the other widely distributed in Argentina. Within the latter, network analytical approaches to LD found three clusters of correlated loci (LD-clusters), with inversion karyotypes explaining >79% of the genetic variation. Outlier loci associated with environmental variables mapped to two of these LD-clusters. Furthermore, despite the complex geographical history indicated by population genetic analyses, the clines in inversion karyotypes have remained stable for more than 20 generations, implicating their role in adaptation and differentiation within this lineage. We hypothesize that these clines could be the consequence of a coupling between extrinsic postzygotic barriers and spatially varying selection along environmental gradients resulting in a hybrid zone. These results provide a framework for future investigations about candidate genes implicated in rapid adaptation to new environments.Peer reviewe
Ursodeoxycholate reduces ethinylestradiol glucuronidation in the rat: Role of prevention in estrogen-induced cholestasis
ABSTRACT Ethinylestradiol (EE) administration (5 mg/kg, s.c., daily for 5 days) to rats leads to cholestasis, and its derivative EE 17-glucuronide is a likely mediator of this effect. Coadministration of ursodeoxycholate (UDC) was shown to prevent ethinylestradiol-induced cholestasis. The aim of this study was to evaluate the inhibitory effect of UDC on EE glucuronidation in vivo and in vitro as a potential mechanism to explain UDC protection. UDC treatment (25 mg/kg, i.p., daily for 5 days) decreased the biliary excretion of EE 17-glucuronide in bile after administration of a trace dose of [ 3 H]EE and reduced microsomal EE 17-glucuronidation activity by 20% and expression of UGT2B1, one of the enzymes involved in EE conjugation, by 30%. Glucuronidation kinetic studies were performed in vitro using normal microsomes and isolated hepatocytes in the presence of tauroursodeoxycholate (TUDC), the major endogenous derivative of UDC in the rat. Kinetic enzymatic studies in microsomes showed a noncompetitive inhibition of EE 17-glucuronidation by TUDC, which was unique for this bile salt since other endogenous bile salts such as taurocholate, taurochenodeoxycholate, or taurodeoxycholate did not affect the enzyme activity. Studies in isolated hepatocytes confirmed the inhibitory effect of TUDC on EE glucuronidation and indicated that TUDC can reach the enzyme active site in intact cells. In conclusion, both in vivo and in vitro experiments indicate that UDC decreased the metabolic pathways involved in EE glucuronidation, hence decreasing the formation of the cholestatic derivative EE 17-glucuronide
Una solución multiparadigma para el desarrollo de software
El liderazgo efectivo de proyectos de tecnología es fundamental para asegurar que tales proyectos concluyan satisfactoriamente, entregando productos de calidad y valor agregado. En particular, este liderazgo es crucial para las iniciativas de gobierno electrónico. En este trabajo se presenta la línea de investigación en Coordinación y Liderazgo de Tecnología para Gobierno Electrónico que tiene como objetivo definir un framework que permita la implementación y el sostenimiento de un modelo de líderes de tecnología para el sector público (Chief Information Officer) en Gobierno (GCIO). Asimismo, y con el objetivo de asegurar la disponibilidad de recursos humanos capaces de cumplir con las responsabilidades de esta función, se pretende desarrollar currícula para una especialización en GCIO.Eje: Innovación en Sistemas de SoftwareRed de Universidades con Carreras en Informática (RedUNCI
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