977 research outputs found
Cosmological parameter inference with Bayesian statistics
Bayesian statistics and Markov Chain Monte Carlo (MCMC) algorithms have found
their place in the field of Cosmology. They have become important mathematical
and numerical tools, especially in parameter estimation and model comparison.
In this paper, we review some fundamental concepts to understand Bayesian
statistics and then introduce MCMC algorithms and samplers that allow us to
perform the parameter inference procedure. We also introduce a general
description of the standard cosmological model, known as the CDM
model, along with several alternatives, and current datasets coming from
astrophysical and cosmological observations. Finally, with the tools acquired,
we use an MCMC algorithm implemented in python to test several cosmological
models and find out the combination of parameters that best describes the
Universe.Comment: 30 pages, 17 figures, 5 tables; accepted for publication in Universe;
references adde
Análisis de procesos de inestabilidad en taludes mediante comparativo entre métodos de equilibrio lÃmite y elementos finitos
Introduction: The article presents research results on the analysis of slope instability processes, conducted at the Universidad Pedagógica y Tecnológica de Colombia in 2019.
Problem: Slope instability processes are permanently present in the state of Boyacá – Colombia. The stability analysis through the application of conventional limit equilibrium methods does not reflect the real conditions of mechanical resistance of the materials found.
Aim: Analyze slope instability processes utilizing the finite element method in two critical spots located on the road that connects the city of Tunja with the town of Miraflores.
Methods: Start with the search and compilation of information from critical spots with relevant geotechnical characterization on roads in the state, thereby permitting the identification of two unstable critical spots. With the use of geological, geotechnical and hydrological information, the mechanical behavior of the materials is modelled through the software Slide and Midas GTS NX.
Results: The estimation of material stability through the finite element method shows more reliable results compared to the actual behavior of the studied locations and compared to the methods based on limit equilibrium.
Conclusion:The use of this numerical simulation technique is recommended to replace conventional methods, being an affordable and effective tool for the analysis of instability processes.
Originality: Most analyses of instability processes conducted in the state of Boyacá – Colombiado not use the finite element method.
Limitations: The estimation of material stability is based on a constitutive model for soil and another for rock
Capacidades de organizaciones vecinales para la gobernanza urbana: caso de estudio en el municipio de Guadalajara (Estudios)
The objective of the article is to study the capacities of neighborhood councils in the individual, organizational and institutional dimensions, in order to observe if the capacities of the neighborhood councils constitutes a limitation to their potential of action and then, to the possibility of contribution to urban governance. The study is applied to a sample of neighborhood councils in the city of Guadalajara, Jalisco, Mexico. The main results is that the neighborhood councils have some limitations because they are weakly established and rudimentary institutionalized organizations. Recommendations are made to strength the capacities of neighborhood councils.El objetivo del trabajo es estudiar las capacidades de las organizaciones vecinales en las dimensiones individual, organizacional e institucional, con la finalidad de evidenciar si representan una limitación a su potencial de acción y, por lo tanto, a su posibilidad de aportar a la gobernanza urbana. El estudio se realiza a cuatro casos de asociaciones vecinales en el municipio de Guadalajara, Jalisco, ubicadas en algunas de las zonas menos favorecidas de la ciudad. El resultado principal es que las asociaciones vecinales estudiadas cuentan con capacidades limitadas debido a que son organizaciones débilmente establecidas y con una institucionalización rudimentaria. De manera general, se formulan recomendaciones para fortalecer las capacidades de las organizaciones vecinales
Gestión de comercialización y la competitividad de las micro y pequeñas empresas agroindustriales del vino, Tacna
La presente investigación es no experimental - relacional, cuyo objetivo es determinar de qué manera se relaciona la gestión de comercialización y la competitividad de las micro y pequeñas empresas agroindustriales del vino en Tacna en el 2015. El diseño fue correlacional, ya que examina la relación existente entre dos o más variables, en la misma unidad de investigación. La población de estudio estuvo constituida por 33 micro y pequeñas empresas agroindustriales Los principales resultados fueron: de las 33 empresas agroindustriales de vino comprendidas en el estudio, 22 presentaron competitividad baja y mayormente gestión desfavorable, 6 empresas competitividad media y preferentemente gestión desfavorable y 7 empresas competitividad alta con una gestión mayormente poco favorable. Se concluye gestión de comercialización y la competitividad de las micro y pequeñas empresas de vino en la ciudad de Tacna , están relacionados a un nivel de confianza del 95 % (2c=18,884 2t=5,99 ; P valor =0,001)
Phytochemical, antioxidant and antimicrobial parameters of essential oils and hydrosols of colombian Thyme and Rosemary obtained using two different steam distillation methods
Two procedures of steam distillation of Rosmarinus officinalis and Thymus vulgaris were compared by phytochemical, antioxidant and antimicrobial analysis of their respective essential oils and hydrosols using respectively GCFID and GCMS analysis, free radical scavenging activity on ABTS and dilution and diffusion method against 3 bacteria and 2 fungi. Differences in bioactivity results are discussed taking into account changes in molecular content of essential oils and hydrosols obtained by the two different distillation methods. Although no significant difference was observed between the two procedures with Rosmarinus officinalis, that was not the case with Thymus vulgaris. Significant differences were noted, not only in their respective chemical composition especially with the thymol and p-cymene percentage with respectively a change from 39% with conventional steam distillation to 27% with adapted steam distillation for thymol and from 28% with the first distillation to 37% with the second one for p-cymene. These phytochemical composition changes have an impact on their biological activities results and consequently on the therapeutic activities expected which shows the importance of distillation method selection
Frecuencia del músculo Palmar Longo. Un estudio con población de Bucaramanga
RESUMEN El propósito de este estudio fue determinar la presencia del Músculo Palmar Longo (MPL) considerando el sexo y el componente étnico en una población de Bucaramanga. Materiales y métodos: se evaluó la presencia del MPL, mediante la visualización directa de su tendón, en los antebrazos de 1214 individuos mayores de 10 años, de sexo masculino y femenino y de raza blanca y mestiza. La expresión del tendón del MPL requiere de una maniobra especÃfica de oposición de los pulgares y flexión de las articulaciones radiocarpianas. Resultados; se observó agenesia global de 20,3%, correspondiendo a los blancos 21.5% y a los mestizos 19%. Considerando el sexo, la agenesia del palmar fue mayor en mujeres (22.2%) que en los hombres (17,2%), siendo la diferencia significativa (chi cuadrado yates corrected x2= 4,07, p< 0.04). Predominó la ausencia muscular bilateral (10.3%) sobre la unilateral izquierda (5.8%) y derecha (4.2%). Conclusiones: la incidencia de la agenesia observada del palmar longo se ubica en un rango intermedio a lo señalado para las poblaciones étnicas: caucasoides, negroides y mongoloides. Existe concordancia con la mayorÃa de estudios que señalan mayor agenesia del palmar en mujeres que en hombres y en el lado izquierdo. Salud UIS 2002; 34: 12-17Palabras Clave: AnatomÃa, Sistema muscular, Palmar longo, Agenesia. ABSTRACT The purpose of this study was to determine the presence of the Palmaris Longus Muscle (PLM) considering the sex and the ethnic component in a population of Bucaramanga. Materials and methods: the presence of the PLM was evaluated, by means of the direct visualization of its tendon, in the forearms of 1214 individuals bigger than 10 years old, of males and females and of white and half-breed race. The expression of the tendon of the PLM requires of a specific maneuver of opposition of the thumbs and flexion of the radiocarpian articulations. Results: global absence of 20.3% was observed, corresponding to the white race 21.5% and to the half-breed race 19%. Considering the sex, the absence of the palmaris longus was bigger in women (22.2%) that in the men (17.2%), being the significant difference {squared Chi: Yates corrected x1 = 4.07,
Metastatic Intraocular Tumor Due to Colorectal Adenocarcinoma: Case Report and Literature Review
Purpose: To describe the clinical and histopathological findings of a case of intraocular metastasis due to colorectal adenocarcinoma and to carry out a literature review.
Case Report: A 64-year-old man with a history of tumor resection due to infiltrating colorectal adenocarcinoma three years previously sought ophthalmological care because of severe ocular pain without response to medical treatment and progressive vision loss in the left eye. On ultrasonographic examination, there was a heterogeneous intraocular choroidal tumor, which occupied approximately 40% of the vitreous cavity, as well as peritumoral serous retinal detachment. The patient underwent left eyeball enucleation. The histopathological diagnosis was metastatic tubular adenocarcinoma involving the retina and choroid that partially infiltrated the sclera and the proximal optic nerve.
Conclusion: The present case highlights a rare pathological entity associated with variable therapeutic schemes and survival times and poor prognosis in patients with metastatic intraocular tumors due to colorectal adenocarcinoma
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