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El objetivo del presente artículo se centra en resumir en forma exhaustiva y concisa las diferentes metodologías de estimación de la volatilidad que se han propuesto para el enfoque de opciones reales (real options approach o ROA) y brindar, además, una explicación teórica y práctica para estimar una volatilidad no sesgada e incondicional para dicha metodología. Los resultados de la investigación sugieren que la utilización de los métodos actuales genera una marcada sobreestimación de la volatilidad, lo que se transmite en última instancia en la sobrevaloración de la opción real. De esta forma se apropia el uso del método de estimación insesgado para determinar su impacto en la toma de decisiones para un proyecto real del sector de petróleo y gas en Colombia, en el que se estimó su valor estratégico por medio del uso de las opciones reales y se comparó con el resultado estático obtenido por el método de flujos de caja descontados (discounted cash flow o DCF); como resultado se encontró que se genera un valor adicional no percibido por la metodología tradicional que está acorde con la respectiva volatilidad que generó el commodity. Se propone que para futuras investigaciones se mantenga la condición de insesgamiento pero que la estimación sea condicional a través de modelos econométricos, con el fin de emular las irregularidades y las características empíricas que se presentan en las series financieras mediante la utilización, por ejemplo, un apropiado sistema de ecuaciones diferenciales estocásticas, como condición necesaria para el comportamiento del precio y de la volatilidad del activo subyacente. || The aim of this paper is to summarize exhaustively and concisely, the different methodologies for estimating the volatility that has been proposed for the real options approach (ROA), and also provide a theoretical and practical explanation for estimating an unbiased volatility and unconditional for this methodology. The results of the research suggest that the use of the current methods generates a marked overestimation of the volatility, which is ultimately transmitted in the overvaluation of the real option. In this way, the application of the unbiased estimation method is used to determine its impact on decision-making for a real project in the oil and gas sector in Colombia, in which its strategic value was estimated through the use of real options, and it was compared with the static result obtained by the method of discounted cash flows (DCF); as a result it was found that, it is generated an additional value not perceived by the traditional methodology, that is consistent with the respective volatility that was generated by the commodity. It is proposed that for future research, unbiasedness condition is maintained, but that the estimate is conditional through econometric models, in order to emulate the irregularities and empirical characteristics presented in the financial series using, for example, an appropriate system of stochastic differential equations, as required condition for the performance of price, and the volatility of the underlying asset.

Introduction: In pregnant anemic women redox biomarkers values are similar with the values of non anemic patients. But inter-correlations of redox parameters in the anemic group can increase the lipid peroxidation products and decrease some importantly antioxidants componentes. Objective: The present study was aimed to investigate the oxidant–antioxidant status of pregnant anemic women by iron deficiency in the third trimester of gestation and its relation to the birthweight. Materials and Methods: The present study comprised of 32 pregnant anemic women aged between 18–42 years and 33 pregnant healthy women as control with a haemoglobin (Hb) >110 g/L ranging in same age. Blood haemoglobin, haematocrit (Hct) and mean corpuscular haemoglobin concentration (MCHC) were determined as haematological parameters. The concentration of iron in plasma was also measured. Ferric reducing potential, albumin, vitamins C, E, A, erythrocyte reduced glutathione concentrations, total extracellular superoxide dismutase and catalase activity were measured as antioxidant indicators, and serum malondialdehyde plus 4-hydroxynonenal concentration as a lipoperoxidation biomarker. Results: The levels of haematological parameters were significantly reduced in the anemic group, but not iron plasma concentration, however, median was reduced in the anemic group. Except of vitamin E levels, no significant differences between the values of the indicators of redox status between the two groups of pregnant women were found. Vitamin E levels were decreased significantly in pregnant non anemic women. The correlations between haematological parameters showed significant correlation with each other except MCHC which did not correlate significantly with Hct. The levels of Hct showed significant and positive correlation with vitamin C levels, but negative with MCHC levels, that correlates significantly and positively with vitamin A concentrations, so, the levels of this vitamin significantly and positively correlate with vitamin E concentrations. The levels of vitamin A also correlate with serum catalase activity. This study showed that Extracellular Superoxide dismutase activity significantly decreased with increased of plasma lipid peroxidation products, and significantly increased with increased of erythrocytes reduced glutathione concentrations. Malondialdehyde plus 4-hydroxy-nonenal concentrations correlated significantly and inversely with birthweight, while erythrocyte reduced glutathione and total extracellular superoxide dismutase activity correlated significantly and directly. Conclusions: On the basis of our results, it may be concluded that in pregnant anemic women redox biomarkers values were similar with the values of non anemic patients, however inter-correlations of redox parameters in the anemic group showed that with an increase of lipid peroxidation products tends to decrease some importantly antioxidants components, which may result in various complications including peroxidation of vital body molecules resulting in increased risk for pregnant women as well as the fetus.

Introducción: La importancia de una adecuada nutrición antes y durante la gestación es un requisito indispensable para garantizar una óptima salud y bienestar tanto de la madre como del producto de la concepción.Un aporte insuficiente de vitaminas puede conducir a un estado de competencia biológica entre la madre y el feto, lo cual puede ir en detrimento del estado de salud de ambos. Objetivo: Evaluar la adecuación del consumo diario y niveles séricos de vitaminas antioxidantes de gestantes atendidas en las áreas de salud de la ciudad de Bayamo, en relación con el estado nutricional a la captación temprana. Métodos: Se realizó un estudio observacional analítico y longitudinal en el que se incluyeron 65 gestantes con edad gestacional entre 25 y 36 semanas. Para la determinación del estado nutricional a la captación se usó el Índice de Masa Corporal, la evaluación dietética se realizó a través de una encuesta semicuantitativa de frecuencia de consumo de alimentos y en el suero sanguíneo se determinó la concentración de las vitaminas C, del α tocoferol y del retinol. Resultados: Predominó la inadecuación en la ingesta y estado del α tocoferol en todos los grupos de embarazadas según el estado nutricional a la captación, mientras que, el consumo y estado de las vitaminas A y C fue adecuado en todos los grupos. Conclusiones: El estado de la vitamina E es de riesgo tanto para las gestantes, como para sus fetos, no así el de las vitaminas C y A.

L’article présente une recherche qui porte sur l’étude des interactions par vidéoconférences entre étudiants français du Lycée Aristide Briand (Évreux) et étudiants mexicains du Centre d’Enseignement de Langues Étrangères (CELE) de l’Université Nationale Autonome du Mexique (UNAM). Il s’agit de décrire et d’analyser ces interactions en se penchant de manière plus spécifique sur les séquences qui mettent en évidence des problèmes d’incompréhension.

This purpose of this research is to identify appropriate rates to discount the flows from real options in situations in which the risk-free rate does not apply, in particular, in incomplete markets. A methodology is proposed for valuing real options based on certainty equivalence, which requires as a principal condition the consideration of preferences represented with utility functions. A constant relative risk aversion (CRRA) utility function is used to represent these preferences. The results indicate that this methodology adequately reflects how the value of a real option changes in accordance with an investor´s preferences.

The International Exhibition of 1878 takes place between Champ de Mars and the Trocadéro. After the defeat of Sedan and the Commune, the event offers to the world an image of the recovery of France and introduces the Third Republic. Despite their commercial nature, International Exhibitions aren’t restricted to a celebration of modern creations. Displayed through retrospectives, archaeological works of the 1878’s Exhibition substantially permeate their time. These pieces arouse nationalism and underlie political or religious disputes. They emphasize by contrast Human progress, or support by comparison the continuity of particular industrial practices.

The archetype of the ‘mad’ represents the paradigm of the otigmatization process and the history of madness appear as an attempt to make it disappear by their medicalization for the benefit of the concept of ‘mental illness ‘. The SMPG international survey results show the failure of the medicalization of madness to reduce stigma. This investigation describes the social representations associated to the archetypes of the ‘mad’, the “mentally ill” and the “depressed”.Made in France (67 sites) and in 17 countries (20 international sites), she describes the variants and invariants of these three archetypes.It describes the factors of significant stigmatization for the group ‘ mad /mentally ill ‘: non-responsibility, non-controllability, medicalization, poor prognosis and dangerousness. Regardless of the country, the hard core of representations combining madness and danger is rooted in the collective imagination and the “mentally ill” bears the attributes of a ‘mad’ medicalized. Conversely, the “depressive” label seems more acceptable and less exposed to stigma.Very few people recognize themselves in the collective representation of the ‘mad’ or the ‘mentally ill’, even those who have diagnosed mental disorders.Therefore, how to exit to the dichotomies madness/reason, us /them that are at the base of the process of stigmatization, if for all the people, and even people who have mental disorders, mad it is the other? This may be the role of the patients themselves to combat the stigma and self-stigma in the years to come.

Se presentaron algunos de los principales estudios y se discutieron resultados que confirman la relación entre el estrés oxidativo y la hipertensión arterial esencial, a partir de indicadores del daño oxidativo, de las defensas antioxidantes, así como de las respuestas de estos a algunos antioxidantes y a otros factores implicados en el origen del estrés oxidativo, que es un estado en el cual existe un desequilibrio entre las especies de alto poder oxidante y los sistemas de defensa antioxidante del organismo. En la actualidad, el estrés oxidativo aparece como una de las varias alteraciones metabólicas descritas en la hipertensión arterial esencial. Se ha demostrado que está implicado tanto en la disfunción endotelial como en la hipertrofia de las células musculares lisas vasculares, con fuertes evidencias de que un trastorno en la vasodilatación dependiente del endotelio pueda ser el fenómeno primarioSome of the main studies were presented and the results confirming the relation existing between oxidative stress and essential arterial hypertension were discussed, starting from oxidative damage indicators, from the antioxidant defenses, as well as from their responses to some antioxidants and to other factors involved in the origin of oxidative stress, which is a state where there is an imbalance among the species of high oxidizing power and the antioxidant defense systems of the organism. Nowadays, the oxidative stress appears as one of the various metabolic disorders described in essential arterial hypertension. It has been proved that it is involved both in the endothelial dysfunction and in the hypertrophy of vascular smooth muscular cells. There are strong evidences that a disorder in the vasodilation depending on the endothelium may be the primary phenomenon

El artículo presenta una investigación que forma parte de un proyecto regional que estudia la dinámica de prácticas plurilingüísticas en contextos escolares pluriculturales de escuelas francesas a donde llegan alumnos de diferentes orígenes. En escuelas de barrios nuevos de la ciudad de Le Mans (Francia) observamos los comportamientos, prácticas y representaciones (o imaginarios) plurilingüísticos de los alumnos y profesores. Concentrados en tres clases de escuela elemental, se suscitan actividades en otras lenguas y se estudia su acogida por el profesor y por los alumnos. Observamos que esas nuevas experiencias los ayudan a aceptar la presencia del plurilingüismo y al desarrollo de competencias lingüísticas variadas en cada estudiante durante la clase. Especialmente se puede constatar el desarrollo de capacidades reflexivas metalingüísticas que forman la base de una verdadera competencia lingüística general.

Se realizó una caracterización nutricional antropométrica y dietética con el objetivo de determinar la existencia de estrés oxidativo en pacientes hipertensos esenciales no tratados del sexo masculino, se estudiaron 20 hipertensos y 25 normotensos. Se determinó la concentración de colesterol total, triacilglicéridos, el potencial reductor férrico y la concentración de malondialdehído en el suero sanguíneo, así como la concentración de glutatión reducido y la actividad de la Cu,Zn superóxido dismutasa en eritrocitos. Se mostró que los pacientes hipertensos estudiados tuvieron una concentración significativamente menor de glutatión reducido y más baja actividad de la superóxido dismutasa que los sujetos normotensos. No se encontró diferencia significativa de los valores del potencial reductor férrico entre los grupos, sin embargo, se constató un aumento de la concentración de malondialdehído en los hipertensos. Se concluyó que en los hipertensos esenciales estudiados existe un incremento en los valores de los indicadores de daño oxidativo y una disminución del estado de las defensas antioxidantes, lo que evidencia una situación de estrés oxidativoA dietary and anthropometric nutritional characterization was made to determine the oxidative stress in untreated male patients with essential hypertension. Twenty hypertensive and 25 normotensive patients were studied. The concentration of total cholesterol, triacylglycerides, iron reducing potential and the concentration of malondialdehyde in blood serum as well as concentration of reduced gluthation and the action of Cu, Zn superoxide dismutase in erythrocytes were determined. It was observed that studied hypertensive patients had a significantly lower concentration of reduced gluthation and lower dismutase superoxide activity than normotensive subjects. There was no significant difference in iron reducing potential among the groups; however, there was an increase in malondialdehyde concentration in hypertensive patients. It was concluded that the studied subjects with essential hypertension experienced increased values of oxidative stress indicators and decrease of antioxidant defenses, which showed the presence of oxidative stress.

Se estudian 28 pacientes con amenorrea en las cuales mediante dosificación de los 17 cetoesteroides y la Prueba de la Progesterona Pregnandiol se analiza la existencia o no en ellas de hiperactividad androgénica, y su origen ovárico o suprarrenal. Se muestra la importancia de la Prueba de la Progesterona Pregnandiol en el estudio de las amenorreas.

This article seeks to analyze military press discourse within the context of a broader perspective about the role played by this press in the coming of democracy to Spain (1975-1982), and the links it maintained with the Spanish political class. More particularly, it aims to study the specific nature of the military review Reconquista (1950-1982) and its ideological evolution from, at its beginning, a Regenerationist approach to the military profession, then as mouthpiece for the pro-Franco military establishment and finally, the changes which took place in its editorial line on the death of General Franco.