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Search Results: 1 - 10 of 222120 matches for " Alejandro D. González "
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Energy Subsidies in Argentina Lead to Inequalities and Low Thermal Efficiency
Alejandro D. González
Energies , 2009, DOI: 10.3390/en20300769
Abstract: Natural gas is the main energy resource for buildings in Argentina. Since 2002, subsidies have kept the prices of this fuel between 9 and 26 times lower than regular prices in other countries. The lowest prices are the result of climate-related subsidies. In cold areas, heating uses several times more energy than locations in Europe with a similar climate. A potential for consumption reductions of up to 70% suggests a very low building thermal performance. The main barriers to finding a solution are the heavy subsidies and public unawareness. Users, government officials, and construction professionals do not identify the very low thermal efficiency. Energy policies to encourage improvements are proposed.
Alejandro Díaz Solís,Aleida González González
Ingeniería Industrial , 2007,
Abstract: Se analizan algunos problemas que pueden existir internamente en un centro educacional, el enfoque hacia la presencia de una no conformidad luego de la implantación de un sistema de gestión de la calidad; además, como base de detección de estas y la trascendencia que puede tener una buena planificación y ejecución de las auditorías de la calidad. Se muestran algunos resultados basados en las acciones correctivas/ preventivas que se adoptaron luego de detectadas las no conformidades, demostrando la posibilidad que brindan estas de mejorar una organización.
Two Approaches to the Study of a Controversial Relationship: Cutaneous Photosensitivity and Anti-Ro/SS-A Autoantibodies  [PDF]
Mariela L. Paz, Eliana M. Cela, Alejandro Ferrari, Adrián D. Friedrich, Juliana Leoni, Daniel H. González Maglio
Open Journal of Rheumatology and Autoimmune Diseases (OJRA) , 2014, DOI: 10.4236/ojra.2014.41001
Abstract: Background: Autoantibodies (Aabs) are the hallmark of numerous systemic autoimmune pathologies (SAPs), for instance anti-Ro/SS-A Aabs are usually found in Systemic Lupus Erythematosus (SLE) and Sjogren’s Syndrome. Cutaneous photosensitivity (CP) is found in most forms and subsets of LE and consists of a skin rash as a result of unusual reaction to sunlight. There are many theories which relate specifically the presence of circulating anti-Ro/SS-A Aabs with the CP phenomenon, though there are several studies which are in disagreement. Results: In this study we analyzed the relationship between CP and anti-Ro Aabs by means of two approaches. The first one included an in vitro model where we evaluated by flow cytometry the binding capacity of affinity-purified Aabs to autoantigens relocalized on apoptotic keratinocyte’s surface. We found that there was no relationship between the binding capacity of serum from 10 selected patients or their corresponding purified anti-Ro52 and anti-Ro60 Aabs, and the presence or absence of CP, neither with the SAPs. The in vivo model consisted of Hairless SKH:1 mice which were induced to produce anti-murine Ro52 and/or Ro60 Aabs and were subsequently irradiated with UVB light. We evaluated the skin histology and also the epidermal production of TNF-α. We found no differences between the groups in neither of the parameters evaluated. Conclusions: These results agree with some studies on the role of the Aabs in CP, considering anti-Ro Aabs not as the only responsible for the manifestation; and disagree with many other authors, who believe in the strong association between these two events.
Drops with non-circular footprints
Pablo D. Ravazzoli,Alejandro G. González,Javier A. Diez
Physics , 2015,
Abstract: In this paper we study the morphology of drops formed on partially wetting substrates, whose footprint is not circular. This type of drops is a consequence of the breakup processes occurring in thin films when anisotropic contact line motions take place. The anisotropy is basically due to hysteresis effects of the contact angle since some parts of the contact line are wetting, while others are dewetting. Here, we obtain a peculiar drop shape from the rupture of a long liquid filament sitting on a solid substrate, and analyze its shape and contact angles by means of goniometric and refractive techniques. We also find a non--trivial steady state solution for the drop shape within the long wave approximation (lubrication theory), and compare most of its features with experimental data. This solution is presented both in Cartesian and polar coordinates, whose constants must be determined by a certain group of measured parameters. Besides, we obtain the dynamics of the drop generation from numerical simulations of the full Navier--Stokes equation, where we emulate the hysteretic effects with an appropriate spatial distribution of the static contact angle over the substrate.
Características psicométricas de la Escala de Ideación Suicida de Beck (ISB) en estudiantes universitarios de la ciudad de México
Socorro González Macip,Alejandro Díaz Martínez,Silvia Ortiz León,Catalina González
Salud mental , 2000,
Abstract: El artículo pretende dar a conocer las características psicométricas: la concordancia diagnóstica y la consistencia interna de la Escala de Ideación Suicida de Beck (ISB), e identificar la frecuencia de la ideación suicida en los adolescentes y describir las características clínicas de los que la presentaron, de acuerdo con el criterio de la escala, en una muestra de 122 estudiantes universitarios que acudieron al Servicio de Psiquiatría del Departamento de Psicología Médica, Psiquiatría y Salud Mental de la Facultad de Medicina de la Universidad Nacional Autónoma de México. El estudio fue de tipo transversal, ex-post-facto, utilizando un procedimiento de muestreo no probabilístico. La muestra quedó integrada por 122 estudiantes de 17 a 25 a os. El clínico detectó que 18.9% de los 122 participantes, tenían ideación suicida, esto es, 23 de ellos; de éstos, 22 fueron correctamente identificados por la Escala ISB. En cuanto a la estructura factorial, la escala quedó conformada por cuatro dimensiones tal como la escala original de Beck de la siguiente manera: Sub-escala I: Las características de sus actitudes hacia la vida y la muerte (5 reactivos), conformada por un factor y con una consistencia interna de alpha = .90. La sub-escala II: Las características de los pensamientos y de los deseos de suicidarse (5 reactivos) arrojó 2 factores, obteniendo coeficientes de alpha = 0.65 en el primero y de alpha = .45 en el segundo, pero se consideró pertinente integrarlos en una sola dimensión. La sub-escala III: Las características del intento suicida (4 reactivos), que se integraron en un factor, alcanzaron una consistencia interna de alpha = .61, y la sub-escala IV: La actualización del intento suicida (2 reactivos), que se considera como un indicador y obtuvo un coeficiente alpha = .45. La Escala de Ideación Suicida de Beck no pretende poder predecir el intento suicida, pero sí valorar la intensidad del deseo de suicidarse para saber si el sujeto corre el riesgo de suicidarse pronto. Por lo tanto, es importante saber si tiene o no la idea de hacerlo y detectarlo oportunamente para evitarlo y proporcionarle un tratamiento adecuado.
Valor pronóstico de la hiperuricemia en la insuficiencia cardíaca crónica Prognostic value of hyperuricemia in chronic heart failure
Alejandro Martínez S,Alejandro González M,Cristián Cerda D,Pedro Pérez C
Revista médica de Chile , 2004,
Abstract: Background: Hyperuricemia has been proposed as a risk marker in chronic heart failure, but its value as an independent prognostic is not well established. Aim: To determine the prognostic value of hyperuricemia, in patients with chronic stable heart failure. Patients and methods: Forty six male patients with chronic heart failure, aged 62±13 years, were studied. Their ejection fraction was less than 40% and their serum creatinine was less than 2 mg/dl. Serum uric acid and catecholamines, maximal oxygen consumption (VO2 max) and left ventricular ejection fraction were measured. Mortality and the need for cardiac transplant were recorded as endpoints during a mean follow up of 39±18 months. The relationship between basal measures and the occurrence of events was analyzed using univariate and multivariate methods. Results: Basal VO2 max and left ventricular ejection fraction were 16±4.6 ml/kg/min and 22±7% respectively. Eighteen patients died and three required transplantation during the follow up. Patients reaching these endpoints had a lower VO2 max and left ventricular ejection fraction and higher uric acid levels. Multivariate analysis accepted left ventricular ejection fraction (relative risk 0.89, 95% CI 0.82-0.97) and serum uric acid (relative risk 1.335 95% CI 1.02-1.74) as significant predictors of events. The relative risk for cardiac transplantation was 7.07 times higher among those with a serum uric acid over 7 mg/dl. Conclusions: A high serum uric acid is an independent predictor of bad prognosis in patients with stable chronic heart failure (Rev Méd Chile 2004; 132: 1031-6
La epigenética y los estudios en gemelos en el campo de la psiquiatría
Adriana Estrella González Ramírez,Alejandro Díaz Martínez,Adriana Díaz Anzaldúa
Salud mental , 2008,
Abstract: La secuencia de ADN genómico que caracteriza a nuestra especie constituye la piedra fundamental de la vida humana; parte de ella se refleja en la secuencia del ARN y a través de éste se dicta la información necesaria para que nuestras células produzcan proteínas. La genética contribuye de manera importante a los avances en el campo médico. Los descubrimientos genéticos han permitido desarrollar estrategias para modificar, prevenir y proponer nuevas terapias para diversas enfermedades. En el siglo XIX, Gregor Johann Mendel desarrolló un modelo teórico capaz de predecir la naturaleza y propiedades de los mecanismos de la herencia, que sigue siendo indispensable para explicar la base de la herencia humana. Otro suceso determinante en la historia de la Medicina se dio a conocer casi nueve décadas después cuando James Watson y Francis Crick describieron su modelo estructural para el ADN. Posteriormente se introdujeron la clonación posicional y la reacción en cadena de la polimerasa; más recientemente se publicó cerca del 99% de la secuencia del genoma humano. El período actual se conoce como la era post-genómica, ya que además de descifrar genomas completos, los investigadores pretenden, entre otras cosas, esclarecer los mecanismos que influyen en la activación e inactivación de los genes, lo cual en parte involucra un nivel epigenético. En las ciencias médicas los gemelos constituyen un grupo idóneo para abordar el estudio de las enfermedades hereditarias. En este tipo de padecimientos suelen observarse similitudes entre parientes, en especial si se trata de gemelos monocigóticos. Sin embargo, aun en este tipo de hermanos se detectan diferencias importantes. Parámetros como los grados de concordancia y porcentajes de heredabilidad han puesto de manifiesto que un gemelo monocigótico puede presentar trastornos hereditarios que su co-gemelo nunca tendrá. La epigenética es el estudio de los cambios en la función de los genes que no afectan la secuencia del ADN, por modificaciones que tienen lugar principalmente en las citosinas de éste y en las histonas de la cromatina. Se ha determinado que las modificaciones epigenéticas son mucho más frecuentes que aquellas que modifican la secuencia del ADN, por lo que constituyen uno de los fundamentos de la diversidad biológica, muestran la manera en que el ambiente puede modular la expresión genética y contribuyen así a nuestro fenotipo. Esta revisión reúne datos sobre la posible relevancia de la epigenética en el estudio de los trastornos mentales y como posible explicación parcial de las diferencias observadas entre ge
Conceptos de enfermedad y sanación en la cosmovisión mapuche e impacto de la cultura occidental
Ciencia y enfermería , 2004, DOI: 10.4067/S0717-95532004000100002
Abstract: this article presents the central aspects of the mapuche cosmology related with sickness and healing. words used in mapudugún, the native language of the mapuche, the concepts of equilibrium, disequilibrium, negative energy, and positive energy are discussed. the activities and roles of the mapuche healing agents as well as those of the individual, are described. the function of the person who is "machi" is presented. finally, the impact of occidental culture over the customs, culture, curative system, and health of the mapuche and pehuenche are evaluated.
Vascularización del útero y los Ovarios del Pécari de Collar (Tayassu tajacu)
Pradere,José D.; Ruiz E.,Ana Z.; González M.,Freddy; Correa,Alejandro;
Revista de la Facultad de Ciencias Veterinarias , 2007,
Abstract: the vascularization of the internal genital tract of the collared peccary (tayassu tajacu) was studied using radiographic, simple dissection and tissue clearing techniques. thirteen (13) postpuberal female, aged 1-2 years, were evaluated. this study showed that the structures the reproductive tract are mainly irrigated by the ovarian, uterine, vaginal, and vestibular arteries. this arterial pattern was reiterative in all animals studied. this research revealed the presence of branches of the ovarian artery, which traverse the thickness of the ovarian vein wall, interconnecting the ovarian and uterine branches of the ovarian artery, at the level of the utero-ovarian vascular pedicle. this work also revealed that the ovary is mainly irrigated by the ovarian branch of the ovarian artery, leading to an anastomosis between the uterine branch of the ovarian artery and the cranial branch of the uterine artery, which supply blood to the cranial end of the uterine horn. furthermore, ipsilateral and contralateral anastomoses among the uterine, vaginal, and vestibular arteries that irrigate the body, cervix, vagina, and vaginal vestibule were evidenced. the uterine branch of the ovarian artery provided the main blood supply to theuterine tuba, setting a difference for the domestic gilt whose uterine tuba is irrigated by the ovarian branch of the ovarian artery. it is concluded that the vascular pattern of the genital tract of the collared peccary, greatly resembles that of the gilt (sus scrofa domesticus).
Anatomía del útero y Ovarios del Capibara (Hydrochoerus hydrochaeris): Irrigación Arterial
Pradere,José D; González M,Freddy; Ruiz, E,Ana Z; Correa,Alejandro;
Revista de la Facultad de Ciencias Veterinarias , 2006,
Abstract: the purpose of this study was to describe, for the first time, the vascular arterial pattern of the uterus and ovaries of the capybara (hydrochoerus hydrochaeris) using single dissection, light microscopy and tissue-clearing techniques. fifteen (15) postpuberal females of different ages (6 months to 2 years) were assessed. this study showed that the anatomical arrangement of the uterine horns, body and cervix is similar to dogs, cats and some rodents such as hamsters and rats. the arterial supply to the reproductive tract is made up of the ovarian, uterine and vaginal arteries all of which establish ipsilateral anastomosis among them. they also establish contralateral anastomosis between the uterine and vaginal arteries. organs evaluated revealed that the uterine artery represents the main arterial vessel to the ovary, sending segmental branches to the horn and uterine body, branching off at the endings into two branches that penetrate deep into the walls of both structures. subsequently, these branches anastomose with opposite homologue vessels. further studies in this area are required to complement the description of the arteriovenous supply. this would allow a better understandingof the reproductive physiology and sexual behavior in this species.
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