Descubriendo Patrones Craneofaciales Usando Datos Cefalométricos Multivariados para la Toma de Decisiones en Ortodoncia

Indexación: Web of Science; Scielo.The aim was to find craniofacial morphology patterns in a multivariate cephalometric database using a clustering technique. Cephalometric analysis was performed in a sample of 100 teleradiographs collected from Chilean orthodontic patients. Thirty cephalometric measurements were taken from commonly used analysis. The computed variables were used to perform a clustering analysis with the k-means algorithm to identify patterns of craniofacial morphology. The J48 decision tree was used to analyze each cluster, and the ANOVA test to determine the statistical differences between the clusters. Four clusters were found that had significant differences (P<0.001) in 24 of the 30 variables studied, suggesting that they represent different patterns of craniofacial form. Using the decision tree, 8 of the 30 variables appeared to be relevant for describing the clusters. The clustering analysis is effective in identifying different craniofacial patterns based on a multivariate database. The distinct clusters appear to be caused by differences in the compensation process of the facial structure responding to a genetically determined cranial and mandible form. The proposed method can be applied to several databases, creating specific classifications for each one of them. KEY WORDS: Craniofacial patterns; Morphological patterns; Clustering technique; Orthodontics.RESUMEN: El objetivo fue encontrar patrones morfológicos craneofaciales, a partir de una base de datos cefalométricos multivariada, utilizando una técnica de clustering. Se realizó un análisis cefalométrico a una muestra de 100 telerradiografías pertenecientes a pacientes chilenos de ortodoncia. Treinta medidas cefalométricas obtenidas de los análisis más utilizados fueron registradas. Las variables computadas se utilizaron para realizar un análisis de clustering con el algoritmo k-medias, para identificar patrones de morfología craneofacial. El árbol de decisión J48 se utilizó para analizar cada cluster, y test de ANOVA para determinar diferencias estadísticamente significativas entre los clusters. Se encontraron cuatro clusters con diferencia estadísticamente significativas (p<0,001) en 24 de las 30 variables estudiadas, lo que sugiere que efectivamente corresponden a diferentes patrones craneofaciales. Utilizando el árbol de decisión, se pudo determinar que 8 de las 30 variables resultaron ser relevantes en la definición de los clusters. El análisis de clustering es efectivo en identificar patrones morfológicos craneofaciales usando una base de datos multivariada. Los distintos cluster encontrados, aparentemente se formarían a partir de diferencias en el proceso de compensación de la estructura facial, en respuesta a la forma mandibular genéticamente determinada. El método propuesto puede ser aplicado a múltiples bases de datos, creando clasificaciones específicas para cada una de ellas. PALABRAS CLAVE: Patrones craneofaciales; Patrones morfológicos; Técnica de clustering; Ortodoncia.http://ref.scielo.org/qdkkz

Factors of material consumption

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 32-34).Historic consumption trends for materials have been studied by many researchers, and, in order to identify the main drivers of consumption, special attention has been given to material intensity, which is the consumption of materials (in mass quantities) per GDP per capita. For our analysis, a new factor, material price, has been taken into account when analyzing the consumption of materials. Rather than focusing only in material intensity, material consumption has been studied in comparison to GDP per capita divided by price, which denotes purchasing capability. Furthermore, material consumption is decomposed into different factors and their contribution is determined for five different materials (aluminum, steel, copper, zinc and cement), for the USA, India, China and at the global level, beginning from 1900 until 2005. For the United States it can be seen that while the consumption per capita vs. purchasing capability shows an initially linearly increasing trend, a drastic slope change occurs posthumously. Similarly, on the global scale, a positive linear trend is observed initially, but is followed by a leveling of the consumption per capita, demonstrating saturation with respect to purchasing capability. On the other hand, the graphs for China and India show an increasing trend throughout the full studied period. Additionally, it has been found that on the second half of the 20th century, the US industry share of the GDP has decreased, as well as the material use within industry, balancing out the increase in population and GDP per capita. China and India on the other hand, show an increase in all factors, hence inducing consumption growth and avoiding saturation. By identifying the factors that influence material consumption, and to what extent, this work contributes to the understanding of human consumption patterns and enables a better approach to problems associated with resource utilization.by Pamela Cristina Silva Díaz.S.B

Low Cost, Carbon-Based Micro- and Nano-Structured Electrodes for High Performance Supercapacitors

Advances in the development of sustainable, low-cost, and reliable energy storage technologies have become a high priority as the demand for high power, and high energy storage devices has risen with emerging technologies in electronics, transportation, and renewable energy systems. Supercapacitors, due to their relatively high energy density and power density, provide an attractive alternative to bridge the gap between conventional batteries and capacitors. Materials ranging from high surface area, inert carbons to Faradaic metal oxides and conducting polymers have been used to achieve a range of performance properties in supercapacitors. However, the development of new technologies faces many challenges, such as sustainability, charge efficiency, capacity, cycle stability and scalable manufacturing processes. In this work, to overcome some of these challenges, we developed straightforward, low-cost approaches for the design of micro- and nano-structured electrodes with enhanced electrochemical performance. Two main pathways were taken (1) manipulation of the electrode composition through the incorporation of lignin, as a redox polymer, into the active electrode material, for enhanced energy density, and (2) modification of the electrode structure through changes in the synthesis process of the electrode materials to improve the electrochemical performance. For the first approach, lignin polymers were incorporated into a conducting polymer during electrochemical polymerization, providing increased Faradaic charge storage from the phenolic lignin groups. Polypyrrole (PPy) electrodes were prepared with alkali lignin (AL) and sulfonated lignin (SLS), and the electrochemical performance was compared with pure PPy films. We demonstrated an increase in capacitance of 30% in PPy/AL compared to PPy/SLS and 56% to PPy. Subsequently, AL and SLS were combined with porous carbon, which is electrochemically inert and non-reactive with lignin to improve the electrode stability and study the electrochemical performance of lignin without possible chemical/physical interactions with PPy. We found that intermediate pore sizes (\u3e40 nm) led to optimal redox activity as lignin cannot get inside small pores, and large pores do not adsorb significant amounts of polymer. In the second approach, lignin was used as a precursor to make high surface area carbon fibers, in which the structure of conventional fibers (polyacrylonitrile) was manipulated to produce porous materials. Decreasing the fiber diameter (115 to 8.5 µm) led to an increase in capacitance from ~2 F/g to ~70 F/g and a chemical activation process resulted in capacitances of ~192 F/g. Under the same scope, high surface area resorcinol–formaldehyde carbon aerogels reinforced with a backbone material allowed the fabrication of free-standing electrodes, eliminating the need for a binder and current collector during supercapacitor assembly. Finally, we developed a template-free synthesis method for creating microstructured electrodes to improve ion transport within thick conducting polymer films (~16 µm) while maintaining high energy storage capacity. Electrodes comprising these materials validate low cost, high energy density and innovative ways to manipulate the chemical composition and physical structure of Faradaic and non-Faradaic materials

Criterios para la gestión sostenible de paisajes culturales extremos: (Hipo/Hiperdesarrollo): Mali, China y México

La relación de los paisajes culturales con el desarrollo sostenible suele ser crítico tanto en situaciones de hipodesarrollo como de hiperdesarrollo. La carencia de estudios, la escasa cartografía y la dificultad para obtener información obstaculizan el trazado de planes de desarrollo y estrategias que mejoren la calidad de vida de la población local al tiempo que se preservan los frágiles valores intangibles. Esta investigación posdoctoral consistió en reconocer el valor de los paisajes culturales extremos como motores de desarrollo, al tiempo que se trazó una metodología para cartografiar el territorio, sus dinámicas, sus intangibles y sus transformaciones con el fin de trazar estrategias de intervención. Al trabajar en China, Malí y México como casos de estudio, las diferencias culturales y en niveles de desarrollo han favorecido el intercambio cultural al tiempo que permiten la extrapolación de la metodología a múltiples contextos en África, Asia, Europa y Latinoamérica.The relationship of cultural landscapes with sustainable development is usually critical in hypodevelopment and hyperdevelopment situations. The lack of studies, scarce maps and difficulties in obtaining information hinder the design of development plans and strategies that would improve the quality of life of local population, whilst preserving the fragile intangible assets. This postdoctoral research consisted of recognising the value of extreme cultural landscapes as engines for development, whilst designing a methodology for mapping the land, its dynamics, its intangibles, and its transformations with the aim of designing strategic interventions. Through taking China, Mexico and Mali as study cases, the differences regarding culture and levels of development have favoured cultural exchange whilst allowing the extrapolation of the methodology to multiple contexts in Africa, Asia, Europe and Latin America

Displacement of Cranial Reference Landmarks Used in Jarabak and Ricketts Cephalometric Analysis During Active Growth

Indexación: Web of Science; Scielo.RESUMEN: El objetivo de este trabajo fue evaluar el desplazamiento de los puntos craneales: Nasion, Silla, Basion, Porion, Orbitario y Pterigoideo, utilizados como referencia en los análisis cefalométricos de Jarabak y Ricketts durante el crecimiento activo. Se seleccionaron 120 telerradiografías de perfil en formato digital, correspondientes a 60 pacientes con 2 telerradiografías cada uno, tomadas con un intervalo de tiempo mínimo de 1 año (T1 y T2), en donde T1 se encuentra antes o durante el peak de crecimiento según el Estado de Maduración Cervical Vertebral (CVM) I, II ó III de Baccetti y T2 en estadio CVM IV,V,VI (después del peak de crecimiento). Un examinador previamente calibrado, ubicó los puntos analizados y para evaluar su desplazamiento, se realizaron mediciones en T1 y T2 (3 variables para cada punto), usando como referencia 2 planos que no se modifican a partir de los 5 años de edad (LCB y Vert-T). Para determinar el desplazamiento de los puntos, se calculó la variación promedio observada entre T1 y T2 y se realizó la prueba t para muestras pareadas o Wilcoxon (según distribución) para determinar la existencia de diferencias significativas. Además, se comparó la muestra por sexo, CVM inicial y CVM final. Se encontraron variaciones entre T1 y T2 en todas las medidas, aunque sólo en 5 de ellas se encontraron diferencias significativas; no se encontró diferencias al comparar por sexo, CVM inicial y final. Es así como podemos concluir que todos los puntos craneales analizados sufren desplazamiento durante el crecimiento. Los puntos Basion y Orbitario son los que sufren mayor desplazamiento. Es necesario analizar las implicancias de estas variaciones en los resultados obtenidos de los análisis cefalométrico y evaluar la necesidad de utilizar puntos de referencia alternativos.SUMMARY: The objective of this study was to evaluate the displacement of cranial reference points: Nasion, Sella, Basion, Porion, Orbitale and Pterygomaxillary, used in Jarabak and Ricketts cephalometric analysis, during active growth. Hundred and twenty digitalized lateral telerradiographies, corresponding to 60 patients (2 teleradiographies each one), were collected. The radiographies were taken with a minimum interval of one year between them (T1 and T2), where T1 is taken before or during the pubertal growth peack according to the cervical vertebral maturation stages developed by baccetti (CVM) I, II or III and T2 in CVM IV,V,VI (after the growth peak). Then, a previously calibrated examinator marked reference points and cephalometric measurements were taken (2 variables for each landmark). Measurements were made using craniofacial stable structures as references (stable basicranial line and Vertical T). To detect displacement in the landmark positions, t test or Wilcoxon test according to the distribution of each variable, was used to compare the data between T1 and T2. Also, comparisons were made by sex, and by initial and final CVM. All of the variables have variations between T1 y T2, but only 5 have a statistically significant difference. There were no differences between sexes and at initial and final CVM. In conclusion, all of the reference landmarks analyzed had displacement during active growth. Point Basion and Orbitale suffered the largest displacement. It is necessary to analyze the clinical implications of this displacement in order to evaluate the convenience of using alternative reference landmarks.http://ref.scielo.org/rf877

El microcrédito, una herramienta para contrarrestar la pobreza, el caso México (2000-2008).

La pobreza es un tema de gran debate, no es patrimonio de país alguno, no es carencia espontánea, es como muchos fenómenos sociales, producto y resultado de determinadas políticas económicas y formas de organización social. Entonces, es un tema que no está relacionado con un solo país, más bien es una cuestión de carácter mundial. En el caso particular de México, a partir de 1982 adopto el modelo neoliberal, y aunque ciertamente se solucionaron algunos problemas que aquejaban al país, esto se desvaneció ante las crisis financieras de 1987, 1994, 2003 y recientemente la de 2008

Carga bacilar como predictor de respuesta al tratamiento en pacientes con Tuberculosis Pulmonar

La tuberculosis (TB) es una de las principales enfermedades infecto contagiosas en el Perú con un tratamiento largo y en muchas ocasiones difícil, por lo tanto, poder predecir el resultado post tratamiento resulta necesario. Objetivo: Evaluar si la carga de bacilos ácido alcohol resistentes (BAAR) en la baciloscopía, con diferentes grados de positividad, es un predictor de la respuesta al tratamiento antituberculoso. Método: Estudio tipo cohorte histórico en elccual serrevisaron 235 historiasdde pacientes con TB divididos según el resultado de su baciloscopía a los 2 meses de terapia antituberculosa (65 con resultado positiva y 170 con resultado negativo) atendidos en el Hospital Víctor Lazarte Echegaray en el periodo 2010- 2019. Resultados: El 55% de los pacientes que no negativizaron presentaron una alta carga bacilar en el diagnóstico, mientras que solo hubo un 7% de carga bacilar alta en quienes sí tuvieron adecuada respuesta al tratamiento antituberculoso, correspondiente a un incremento del riesgo mala respuesta en 15.64 veces (IC95%: 6.3-38.8) luego de ajustar a las variables de confusión. Conclusión: La alta carga de BAAR en la baciloscopía es un predictor de mala respuesta al tratamiento antituberculoso.Tuberculosis (TB) is one of the main infectious and contagious diseases in Peru with a long and often difficult treatment, therefore, being able to predict the post treatment outcome is necessary. Objective: To assess whether the smear load, with different degrees of positivity, is a predictor of the response to tuberculosis treatment. Method: a historical cohort study in which 235 histories of patients with TB were divided according to the result of their smear after 2 months of tuberculosis therapy (65 with a positive result and 170 with a negative result) treated at the Víctor Lazarte Echegaray Hospital in the period 2010 - 2019. Results: 55% of patients who did not negativize had a high bacillary load in the diagnosis, while there was only 7% high bacillary load in those who did have adequate response to tuberculosis treatment, corresponding to an increased risk Bad response in 15.64 times (95% CI: 6.3-38.8) after adjusting for confounding variables.Tesi

Cultura organizacional y su influencia en el desempeño laboral de los colaboradores de la empresa Compured SAC, Trujillo 2020.

La presente investigación titulada “cultura organizacional y su influencia en el desempeño laboral de los colaboradores de la empresa Compured sac, Trujillo 2020”. Tuvo como objetivo principal: Determinar la influencia de la cultura organizacional en el desempeño de los colaboradores de la empresa Compured SAC, Trujillo 2020. Esta investigación según su finalidad es aplicada, según su alcance es correlacional, según su temporalidad es transversal, de enfoque cuantitativo y de diseño no experimental. Para la recolección de datos se utilizó como técnica la encuesta y como instrumento el cuestionario. La muestra objeto de estudio fue de 30 personas. Con lo cual se obtuvo como resultado que si existe relación entre la Cultura organizacional y el desempeño de los colaboradores de la empresa Compured SAC, con un coeficiente de Pearson de 0.419. Mostrando que, al mejorar el Cultura organizacional, se mejora el desempeño. Además, se pudo definir que el Cultura organizacional influye en 17.6% en la variación del desempeño. Como posible solución es proponer la Comunicación como factor fundamental, para ello es importante tener en cuenta y aplicar de forma constante las formas de comunicación; entregar la información tanto por escrito como por medios electrónicos con la necesaria claridad, fluidez y oportunidad para conseguir que se comprenda y alcanzar el éxito anhelado.The present research entitled "organizational culture and its influence on the work performance of the collaborators of the company Compured sac, Trujillo 2020". Its main objective was to determine the influence of organizational culture on the performance of employees of the company Compured SAC, Trujillo 2020. This research according to its purpose is applied, according to its scope it is correlational, and according to its temporality it is transversal, quantitative approach and non-experimental design. For data collection, the survey was used as a technique and the questionnaire as an instrument. The sample under study consisted of 30 people. As a result, it was found that there is a relationship between organizational culture and the performance of the employees of Compured SAC, with a Pearson coefficient of 0.419, showing that by improving the organizational culture, performance improves. In addition, it was possible to define that the Organizational Culture influences 17.6% in the variation of performance. As a possible solution is to propose Communication as a fundamental factor, for this it is important to take into account and constantly apply the forms of communication; deliver the information both in writing and by electronic means with the necessary clarity, fluency and timeliness to ensure that it is understood and achieve the desired success.Tesi

El plan integrado de la ONU en apoyo a la respuesta al SIDA en el Amazonas y Bahia, Brasil : una experiencia interprogramática e intersectorial de cooperación técnica

Este artigo apresenta o Plano Integrado das Nações Unidas em Apoio à resposta à Aids no Amazonas e na Bahia, uma iniciativa de mobilização conjunta do Sistema das Nações Unidas no Brasil em implementação desde o final de 2007. Estabelecido a partir da prioridade nacional de se responder às inequidades regionais, o “Amazonaids” e o “Laços Sociaids” buscam fortalecer sinergias locais por meio de um apoio coordenado das Agências do Sistema ONU à resposta à epidemia nos dois estados. O artigo apresenta o contexto de elaboração do Plano Integrado, sua construção, regiões e temas prioritários no Amazonas e na Bahia. Descreve, ainda, aforma de organização para implementação das atividades e as lições aprendidas até o momento. O artigo conclui destacando o processo de apropriação e liderança locais na implementação das atividades e tambémno processo de fortalecimento de ações conjuntas e integradas das Nações Unidas no Brasil, como preconizado no processo de reforma da ONU.This article presents the UN IntegratedPlan in Support to the AIDS responsein Amazonas and Bahia, a joint UNmobilization initiative, being implementedin Brazil since late 2007. Establishedfrom the national priority to respond toregional inequities, the “Amazonaids” and“Laços Sociaids” seek to strengthen localsynergies through coordinated supportof the UN system agencies to respond tothe epidemic in the two states. The articlepresents the context for the elaborationof the Integrated Plan, its development,regions and priority areas in Amazonas andBahia. It also describes the organization forimplementing the activities and lessonslearned so far. The paper concludesby highlighting the process of local ownership and leadership in implementingthe activities and also in the process ofstrengthening joint and integrated actionsof the United Nations in Brazil, as foreseenin the process of UN reform.En este artículo presenta el Plan Integradode la ONU en Apoyo a la respuesta alSIDA en Amazonas y Bahía, una iniciativaconjunta de movilización del sistema de lasNaciones Unidasimplementado en Brasildesde finales de 2007. Fue establecidoa partir de la prioridad nacional deresponder a las desigualdades regionales.Los proyectos “Amazonaids” y “LazosSociaids” buscan reforzar las sinergiaslocales mediante el apoyo coordinado delos organismos del sistema de las Naciones Unidas para responder a la epidemia en losdos estados. El artículo presenta el contextode la elaboración del Plan Integrado, suconstrucción, las regiones y las prioridadestemáticas en Amazonas y en Bahia.También describe la forma de organizaciónpara la ejecución de las actividades y laslecciones aprendidas hasta ahora. Tambiéndescribe la forma de organización para laejecución de las actividades y las leccionesaprendidas hasta ahora.El documento concluye destacando elproceso de apropiación y liderazgo local enla ejecución de las actividades y también enel proceso de fortalecimiento de accionesconjuntas e integradas de las NacionesUnidas en Brasil, como se recomienda enel proceso de reforma de la ONU