Impacto de dos técnicas quirúrgicas sobre la recaída local de carcinoma de mama en pacientes de una clínica de Bogotá D.C.

Introducción: El carcinoma de mama es el tumor maligno más frecuente entre las mujeres y representa una significativa mortalidad en los países en vías de desarrollo. Según datos del Instituto Nacional de Cancerología en el 2010 se reportaron 672 nuevos casos de cáncer de mama, lo que representó el 18% de todos los tumores malignos en mujeres. Durante las últimas 3 décadas las técnicas quirúrgicas para el tratamiento del cáncer de mama han presentado un cambio significativo y proponen disminución de procedimientos agresivos y radicales, intervenciones como: mastectomía radical modificada, cirugía conservadora y la disección de ganglio centinela son ejemplos claros de esta evolución asociado al incremento de la reconstrucción mamaria inmediata. Metodología: Estudio observacional tipo cohorte retrospectivo en el cual se revisó una base de datos de pacientes con cáncer de mama de las cuales 632 fueron sometidas a mastectomía radical con preservación de piel y complejo areola-pezón y mastectomía radical con preservación de piel sin preservación del complejo areola-pezón, los dos procedimientos asociados a reconstrucción mamaria inmediata y se comparó la frecuencia de recaída local entre los dos grupos. Resultados: De las 632 pacientes estudiadas al 30.5% se les realizo preservación del complejo areola pezón. Las mujeres a quienes se les realizó preservación del complejo areola pezón presentaron menor sobrevida a la recaída local a 10 años (80.51%) comparado con las mujeres a quienes no se les preservó el complejo areola pezón (87.40%), sin embargo no se encontró diferencia estadísticamente significativa para determinar que las probabilidades de sobrevida sean diferentes. Discusión: No se evidenció diferencia estadísticamente significativa entre los 2 procedimientos quirúrgicos (con y sin preservación del complejo areola pezón) en relación a la recaída local, estudios retrospectivos no han evidenciado una mayor tasa de recaídas locales en pacientes a quienes se les preserva el complejo areola-pezón, sin embargo hacen falta estudios prospectivos y aleatorizados que puedan otorgar un mayor sustento científico que garantice la seguridad de la preservación del complejo areola-pezón.

Impacto de dos técnicas quirúrgicas sobre la recaída local de carcinoma de mama en pacientes de una clínica de Bogotá D.C.

Introducción: El carcinoma de mama es el tumor maligno más frecuente entre las mujeres y representa una significativa mortalidad en los países en vías de desarrollo. Según datos del Instituto Nacional de Cancerología en el 2010 se reportaron 672 nuevos casos de cáncer de mama, lo que representó el 18% de todos los tumores malignos en mujeres. Durante las últimas 3 décadas las técnicas quirúrgicas para el tratamiento del cáncer de mama han presentado un cambio significativo y proponen disminución de procedimientos agresivos y radicales, intervenciones como: mastectomía radical modificada, cirugía conservadora y la disección de ganglio centinela son ejemplos claros de esta evolución asociado al incremento de la reconstrucción mamaria inmediata. Metodología: Estudio observacional tipo cohorte retrospectivo en el cual se revisó una base de datos de pacientes con cáncer de mama de las cuales 632 fueron sometidas a mastectomía radical con preservación de piel y complejo areola- pezón y mastectomía radical con preservación de piel sin preservación del complejo areola-pezón, los dos procedimientos asociados a reconstrucción mamaria inmediata y se comparó la frecuencia de recaída local entre los dos grupos. Resultados: De las 632 pacientes estudiadas al 30.5% se les realizo preservación del complejo areola pezón. Las mujeres a quienes se les realizó preservación del complejo areola pezón presentaron menor sobrevida a la recaída local a 10 años (80.51%) comparado con las mujeres a quienes no se les preservó el complejo areola pezón (87.40%), sin embargo no se encontró diferencia estadísticamente significativa para determinar que las probabilidades de sobrevida sean diferentes. Discusión: No se evidenció diferencia estadísticamente significativa entre los 2 procedimientos quirúrgicos (con y sin preservación del complejo areola pezón) en relación a la recaída local, estudios retrospectivos no han evidenciado una mayor tasa de recaídas locales en pacientes a quienes se les preserva el complejo areola-pezón, sin embargo hacen falta estudios prospectivos y aleatorizados que puedan otorgar un mayor sustento científico que garantice la seguridad de la preservación del complejo areola-pezón.

Diferencias entre la regla de exclusión probatoria nacional y la regla de exclusión del Derecho Internacional Penal: análisis de tres casos de injerencias en comunicaciones privadas.

Teniendo en cuenta tres casos dentro del contexto del conflicto armado donde la jurisdicción penal colombiana estudia la admisión o exclusión de medios probatorios producidos a partir de injerencias de comunicaciones, encontramos que no siempre se aplica la regla de exclusión cuando no cuentan con una orden judicial previa. Ante este problema, buscamos como se ha solucionado, teniendo como referente la el Derecho Internacional Humanitario, el Derecho Internacional de los Derechos Humanos. Lo anterior nos da base para entender la regla de exclusión de que se ha venido desarrollando dentro del Derecho Internacional Penal. Si bien estas reglas nos sirven para solucionar estos tres casos, terminan siendo contradictorios a lo que ha venido desarrollando la Corte Constitucional. De esta manera, si bien esta Corte consideró que la regla de Estatuto de Roma, va en concordancia con la nuestra regla de exclusión nacional, tal afirmación es errónea.

El desempeño de Unamsil en el programa DDR durante el proceso de paz en Sierra Leona. Estudio de caso: los niños soldados. 1998-2005

El interés de este Estudio de Caso es investigar la manera en que la Misión de Paz de la ONU en Sierra Leona (UNAMSIL) redireccionó el programa Desarme, Desmovilización y Reintegración (DDR) hacia los niños soldados durante el post-conflicto en el país. Se analiza cómo a través de la coordinación de diferentes Agencias y Organizaciones Internacionales con UNAMSIL, el Gobierno y la Sociedad Civil hace posible que se refuerce el rol de los Interim Care Centers (ICCs) en donde se enfrentaron las necesidades esenciales de los menores excombatientes para lograr un mejor proceso de su desmovilización y reintegración. Se explica de igual forma, las diferentes herramientas que sirven para llevar a cabo la resolución del conflicto y la reconstrucción de la paz, enfocándose en el peacekeeping, peacemaking y peacebuilding, como mecanismos que ayudaron a crear un espacio seguro para los niños exsoldados. Por último, se exponen los alcances y límites de los ICCs con respecto a la reintegración de los menores excombatientes

Relación de los factores laborales e individuales con la carga mental de los trabajadores de una institución minera (2014)

Objetivo: Establecer la relación de los factores laborales e individuales con la carga mental en los trabajadores del área de contratación y titulación minera y los de seguimiento y control en una institución minera durante el año 2014. Materiales y métodos: Estudio de corte transversal en 298 trabajadores que trabajan en una Institución Minera, en la ciudad de Bogotá. La identificación de los factores laborales e individuales relacionados con la carga mental se hizo mediante la aplicación de un cuestionario autodiligenciado utilizando la guía de Estimación de la carga mental de trabajo: método NASA TLX, en el cual se realizó análisis de medidas de tendencia central y se indagó relación a través de la prueba Chi cuadrado de Pearson, usando nivel de significación del 5%, con el programa SPSS 20. Resultados: La población predominante era de género masculino, donde la mayoría de los trabajadores fueron ingenieros pertenecientes al área de seguimiento y control, se evidenció asociación estadísticamente significativa entre la profesión con la percepción de exigencia física (p ≤ 0,001), de igual modo entre área de trabajo con la percepción de exigencia mental (p ≤ 0,001), en la cual se establece que la carga mental y el factor profesional (técnicos) y el factor laboral (área de seguimiento y control), son determinantes para la aparición de fatiga fisiológica y cognitiva, ya que en estos se evidencia mayor exigencia física en los trabajadores técnicos con un 81,40% y en los trabajadores del área de seguimiento y control con un 99,04%. Conclusión: Se encontró una alta exigencia mental, temporal y esfuerzo en los trabajadores y una relación significativa entre la profesión con la percepción de exigencia física, predominando en los técnicos, seguidos de abogados e ingenieros y entre el área de trabajo con la percepción de exigencia mental, siendo mayor en el área de seguimiento y control.

The Upper Valanginian (Early Cretaceous) positive carbon-isotope event recorded in terrestrial plants

Our understanding of the ancient ocean-atmosphere system has focused on oceanic proxies. However, the study of terrestrial proxies is equally necessary to constrain our understanding of ancient climates and linkages between the terrestrial and oceanic carbon reservoirs. We have analyzed carbon-isotope ratios from fossil plant material through the Valanginian and Lower Hauterivian from a shallow-marine, ammonite-constrained succession in the Crimean Peninsula of the southern Ukraine in order to determine if the Upper Valanginian positive carbon-isotope excursion is expressed in the atmosphere. delta(13)C(plant) values fluctuate around -23% to -22% for the Valanginian-Hauterivian, except during the Upper Valanginian where delta(13)C(plant) values record a positive excursion to similar to-18%. Based upon ammonite biostratigraphy from Crimea, and in conjunction with a composite Tethyan marine delta(13)C(carb) curve, several conclusions can be drawn: (1) the delta(13)C(plant) record indicates that the atmospheric carbon reservoir was affected; (2) the defined ammonite correlations between Europe and Crimea are synchronous; and (3) a change in photosynthetic carbon-isotope fractionation, caused by a decrease in atmospheric PCO2, occurred during the Upper Valanginian Positive delta(13)C excursion. Our new data, combined with other paleoenvironmental and paleoclimatic information, indicate that the Upper Valanginian was a cool period (icehouse) and highlights that the Cretaceous period was interrupted by periods of cooling and was not an equable climate as previously thought. (C) 2005 Elsevier B.V. All rights reserved.

Deriving a sea surface temperature record suitable for climate change research from the along-track scanning radiometers

We describe the approach to be adopted for a major new initiative to derive a homogeneous record of sea surface temperature for 1991–2007 from the observations of the series of three along-track scanning radiometers (ATSRs). This initiative is called (A)RC: (Advanced) ATSR Re-analysis for Climate. The main objectives are to reduce regional biases in retrieved sea surface temperature (SST) to less than 0.1 K for all global oceans, while creating a very homogenous record that is stable in time to within 0.05 K decade−1, with maximum independence of the record from existing analyses of SST used in climate change research. If these stringent targets are achieved, this record will enable significantly improved estimates of surface temperature trends and variability of sufficient quality to advance questions of climate change attribution, climate sensitivity and historical reconstruction of surface temperature changes. The approach includes development of new, consistent estimators for SST for each of the ATSRs, and detailed analysis of overlap periods. Novel aspects of the approach include generation of multiple versions of the record using alternative channel sets and cloud detection techniques, to assess for the first time the effect of such choices. There will be extensive effort in quality control, validation and analysis of the impact on climate SST data sets. Evidence for the plausibility of the 0.1 K target for systematic error is reviewed, as is the need for alternative cloud screening methods in this context.

Bilayer graphene formed by passage of current through graphite: evidence for a three-dimensional structure

The passage of an electric current through graphite or few-layer graphene can result in a striking structural transformation, but there is disagreement about the precise nature of this process. Some workers have interpreted the phenomenon in terms of the sublimation and edge reconstruction of essentially flat graphitic structures. An alternative explanation is that the transformation actually involves a change from a flat to a three-dimensional structure. Here we describe detailed studies of carbon produced by the passage of a current through graphite which provide strong evidence that the transformed carbon is indeed three-dimensional. The evidence comes primarily from images obtained in the scanning transmission electron microscope using the technique of high-angle annular dark-field imaging, and from a detailed analysis of electron energy loss spectra. We discuss the possible mechanism of the transformation, and consider potential applications of “three-dimensional bilayer graphene”.

Sugarcane Phosphoribosyl Pyrophosphate Synthetase: Molecular Characterization of a Phosphate-independent PRS

Phosphoribosyl pyrophosphate synthetase (PRS-EC:2.7.6.1) is an important enzyme present in several metabolic pathways, thus forming a complex family of isoenzymes. However, plant PRS enzymes have not been extensively investigated. In this study, a sugarcane prs gene has been characterized from the Sugar Cane Expressed Sequence Tag Genome Project. This gene contains a 984-bp open reading frame encoding a 328-amino acid protein. The predicted amino acid sequence has 77% and 78% amino acid sequence identity to Arabidopsis thaliana and Spinacia oleracea PRS4, respectively. The assignment of sugarcane PRS as a phosphate-independent PRS isoenzyme (Class II PRS) is verified following enzyme assay and phylogenetic reconstruction of PRS homologues. To gain further insight into the structural framework of the phosphate independence of sugarcane PRS, a molecular model is described. This model reveals the formation of two conserved domains elucidating the structural features involved in sugarcane PRS phosphate independence. The recombinant PRS retains secondary structure elements and a quaternary arrangement consistent with known PRS homologues, based on circular dichroism measurements.

The Optimal trigger speed of vehicle activated signs

The thesis aims to elaborate on the optimum trigger speed for Vehicle Activated Signs (VAS) and to study the effectiveness of VAS trigger speed on drivers’ behaviour. Vehicle activated signs (VAS) are speed warning signs that are activated by individual vehicle when the driver exceeds a speed threshold. The threshold, which triggers the VAS, is commonly based on a driver speed, and accordingly, is called a trigger speed. At present, the trigger speed activating the VAS is usually set to a constant value and does not consider the fact that an optimal trigger speed might exist. The optimal trigger speed significantly impacts driver behaviour. In order to be able to fulfil the aims of this thesis, systematic vehicle speed data were collected from field experiments that utilized Doppler radar. Further calibration methods for the radar used in the experiment have been developed and evaluated to provide accurate data for the experiment. The calibration method was bidirectional; consisting of data cleaning and data reconstruction. The data cleaning calibration had a superior performance than the calibration based on the reconstructed data. To study the effectiveness of trigger speed on driver behaviour, the collected data were analysed by both descriptive and inferential statistics. Both descriptive and inferential statistics showed that the change in trigger speed had an effect on vehicle mean speed and on vehicle standard deviation of the mean speed. When the trigger speed was set near the speed limit, the standard deviation was high. Therefore, the choice of trigger speed cannot be based solely on the speed limit at the proposed VAS location. The optimal trigger speeds for VAS were not considered in previous studies. As well, the relationship between the trigger value and its consequences under different conditions were not clearly stated. The finding from this thesis is that the optimal trigger speed should be primarily based on lowering the standard deviation rather than lowering the mean speed of vehicles. Furthermore, the optimal trigger speed should be set near the 85th percentile speed, with the goal of lowering the standard deviation.

Imagens e contra-imagens do estado": considerações sobre a sociedade civil em Gramsci e Habermas

The theme of civil society has resonated significantly in the analysis of social science studies and has long been the center of public opinion, applied to a vast range of contexts, significances and political ideological connotations. Starting with such an unstable theoretical scenario, our research proposal scrutinized two civil society analysis traditions. Embodied by Antonio Gramsci and Jürgen Habermas, these politically conceptual differences are significantly divided into distinct interpretations of the relationship between the state and civil society. On one side, in Gramsci's work, we observe civil society as historically constituted through "molecular expansion of the state", organizing itself during its obligatory constitutive moment. On the other, Habermas shows us a civil society instituted from the structural differentiation process of society developed due to the contradiction existing between the different ways the state administration is organized, the economy and daily social interaction (in which it is found). As a consequence, civil society is no longer seen as a political arena and the hegemonic catalyst of the state, but as a social arrangement destined to increase the viability of the ethical and dialogical reconstruction of social life. It follows that the understanding of the distinctions between both models of civil society become crucial in the measure that they are divided in relation to the delineation of acting agents, fighting strategies, and to the objective of their actions.Despite the existence of analytical dissonance, we intend to outline the common points between both these civil society analysis traditions whose conflicting political action models lead us to a greater understanding of our contemporary political scene. This will be done starting with the systematization of both selected authors' principal categories, and through the introduction of the "contra-hegemonic public sphere" concept

Formação de professores, saberes, reflexividade e apropriação da cultura digital no Projeto Um Computador por Aluno (UCA)

This study investigates teacher training and cognitive practice of teachers in a Basic Education school that adopted the Project One Computer per Student (OCS) in their school routine. Its relevance consists in provide directions for the continuation of training activities on the Project and guide the teachers with their pedagogical practices using the laptop model one to one. The thesis defended is that the educator formation for social using of digital media (specially the laptops from the Project UCA) gives space to establish new sociotechnical relationships, of new social and professionals practices, new identitary components and a process of reflexivity and knowledge reconstruction to teach. We reaffirm the importance of reflexivity and appropriation of digital culture for the better development of teaching practice using the Information and Communication Technologies (ICTs), giving focus to the aspects of social and professional use of the technology. The study is part of the qualitative aspect and is a procedural tracking based on principles of ethnographic research. As procedures and methodological tools, were used: intensive observation of school environments, documental analysis, focal group, semi-structured questionnaires and semi-structured individual interviews. The research was held in a public school in the city of Parnamirim - RN. The subject sample relates to 17 teachers, coming from the elementary school I and II, Youth and Adult Education and High School, who went through the process of training UCA and having entered the laptops in their teaching. The research corpus is structured based on the messages built into the process of data collection and is analyzed based on principles of Content Analysis, specified by Laurence Bardin (2011). Was taken as theoretical reference studies by Tardif (2000; 2011), Pimenta (2009), Gorz (2004, 2005), Giddens (1991), Dewey, J. (1916), Boudieu (1994; 1999), Freire (1996; 2005), among others. The analysis indicates a process of reconstruction / revision of knowledge to teach and work in digital culture, being these knowledges guided by the experience of the subjects investigated. The reconstructed knowledges will be revealed from a categorization process. The following groups of knowledges: "technical knowledges", "didactic-methodological knowledges and knowledges of professionalization" were built on the assumption of ownership of digital culture in the educational context. The analysis confirms the appearance of new ways of sociability when acquiring other forms of acting and thinking ICTs, despite the environment adverse to the reflexivity shared among the teachers. Also reveals, based on the ownership concept present on the data analysis, the construction of meanings of belonging and transformation of individuals into social routes from the interweaving of the teaching practice with the digital culture. Emphasizes, finally, the importance of a training for use of ICTs that exceeds the instrumentation, in other words, what we call "technical knowledges", but taking on its structural basis the shared reflection, the opening for the ressignificance (new meaning) and reconstruction of new knowledges and practices and that really allows, to the teacher, the living of an experience capable of providing socio-technical transformations of their relationships

Measurement of the forward-backward charge asymmetry in top-quark pair production

We present the first measurement of the integrated forward-backward charge asymmetry in top-quark-top-antiquark pair (t (t) over bar) production in proton-antiproton (p (p) over bar) collisions in the lepton+jets final state. Using a b-jet tagging algorithm and kinematic reconstruction assuming t (t) over bar +X production and decay, a sample of 0.9 fb(-1) of data, collected by the D0 experiment at the Fermilab Tevatron Collider, is used to measure the asymmetry for different jet multiplicities. The result is also used to set upper limits on t (t) over bar +X production via a Z' resonance.

Sociedade civil, entre o político-estatal e o universo gerencial

Cet article est fondé sur le concept de société civile développé par le marxiste Antonio Gramsci et propose un dialogue critique avec les autres idées de la société civile qui, de nos jours, cherchent à s'affirmer dans le panorama politique et culturel. Nous nous fondons sur le fait d'être passé, au cours des dernières décennies, d'une idée de société civile prioritairement politique-publique, scène de luttes démocratiques et de nouvelles hégémonies, vers une image qui transforme la société civile soit en ressource de gestion ­ un arrangement de la société destiné à rendre possible différents genres spécifiques de politiques publiques ­ soit en un facteur de reconstruction étique et dialogique de la vie sociale. L'incorporation de l'idée de participation au langage de planification a déplacé la société civile de son champs principal (celui de l'organisation de nouvelles hégémonies) vers un espace de coopération et de gestion de la crise. Par ailleurs, l'expansion de l'activisme social, dans un cadre de crise politique de l'État et de la démocratie représentative a poussé vers la recherche d'une autre «place» à partir de laquelle il serait possible d'établir et de répandre de nouvelles postulations éthiques et de nouvelles procédures collectives. D'une phase où le marxisme était prépondérant et laissait sa marque, nous sommes entrés dans une phase dans laquelle la perspective libérale, affirmée de façon orthodoxe ou nuancée, prévaut et opère comme principale référence.

Porous titanium scaffolds produced by powder metallurgy for biomedical applications

Porous titanium scaffolds are promising materials for biomedical applications such as prosthetic anchors, fillers and bone reconstruction. This study evaluated the bone/titanium interface of scaffolds with interconnected pores prepared by powder metallurgy, using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Porous scaffolds and dense samples were implanted in the tibia of rabbits, which were subsequently killed 1, 4, and 8 weeks after surgery. Initial bone neoformation was observed one week after implantation. Bone ingrowth in pores and the Ca/P ratio at the interface were remarkably enhanced at 4 and 8 weeks. The results showed that the interconnected pores of the titanium scaffolds promoted bone ingrowth, which increased over time. The powder metallurgy technique thus proved effective in producing porous scaffolds and dense titanium for biomedical applications, allowing for adequate control of pore size and porosity and promoting bone ingrowth.