Abstract Microstructure, texture, and mechanical and fracture characterization of three insulating commercial refractories were carried out in order to establish a correlation between these properties. The materials were characterized using X-ray powder diffraction (XRD) with Rietveld and Le Bail approximation to perform phase quantification, mercury intrusion porosimetry, and scanning electron microscopy. The mechanical behavior of insulating commercial refractories was studied with a multi-technique approach that involved a three-point bending test, uniaxial compression test, and single-edge notched beam (SENB) test. Stable fracture tests were successfully performed. The obtained results showed that the main differences between the materials studied were pore size distribution and mineralogical composition. Materials with the major amount of mullite had the highest values of the mechanical parameters in the different performed tests. Microstructure texture properties Xray X ray XRD (XRD quantification porosimetry microscopy multitechnique multi technique threepoint point test singleedge single edge SENB (SENB composition

Abstract Economic growth has a direct link with the volume of cargo at port terminals. To encourage growth, investment decisions on infrastructure are required that can be performed by the development of econometric models. We compare three time-series models and one machine-learning model to estimate and forecast cargo volume. We apply an ARIMA+GARCH+Bootstrap, a multiplicative Holt-Winters, a support vector regression model, and a time-series model with explanatory variables ARIMAX. The models forecast cargo through the ports of San Pedro using data from 2008 to 2016. The database contains imports and exports of bulk, container, reefer, and ro-ro cargo. Results show that the multiplicative Holt-Winters model is the best method to forecast imports and exports of bulk cargo, while the support vector regression model is the best method to forecast imports and exports of container, reefer, and ro-ro cargo. The Diebold-Mariano Test, the RMSE metric, and the MAPE metric validate the results.

RESUMO O objetivo deste trabalho foi mapear e descrever a ocorrência de roedores e seus ectoparasitas nas regiões norte do departamento de La Paz, Bolívia. De abril a maio e julho a agosto de 2017, 80 indivíduos da espécie Oligoryzomys microtis foram capturados em armadilhas vivas. Uma amostra aleatória de 36 indivíduos foi analisada quanto à presença de ectoparasitas, encontrando um total de 458 ectoparasitas. Os roedores foram capturados em dois tipos de ambientes: floresta secundária e áreas cultivadas, sendo a área cultivada a área com maior captação de roedores. Dos ectoparasitas, Laelaps sp. foi o gênero com maior abundância e Mysolaelaps sp. o mais prevalente; o gênero Polygenis sp. é aparentemente descrito pela primeira vez na selva amazônica, exigindo estudos adicionais para entender melhor os patógenos que são transmitidos no parasitismo desta pulga em roedores devido à sua importância no ecossistema e para a saúde pública.

ABSTRACT The objective of this work was to map and describe the occurrence of rodents and their ectoparasites in regions to the North of the department of La Paz in Bolivia. From April to May and July to August 2017, 80 Oligoryzomys microtis rodents were captured and 36 random samples of their ectoparasites were analyzed, totaling 458 ectoparasites. Rodents were captured in two types of environments: secondary forest and crops areas, being the second one with greater amount of capture of rodents. Among the ectoparasites, Laelaps sp was the genus with the highest abundance and Mysolaelaps sp with the highest prevalence; the genus Polygenis sp is apparently described for the first time in the Amazon rainforest, requiring more studies to better understand the pathogens transmitted in the parasitism of this flea in rodents due to their importance in the ecosystem and public health.

Agromyzid leafminers cause damages in ornamental and horticultural crops. The objective of this study was to evaluate the number of adults of L. huidobrensis trapped in sticky traps in C. maxima var. zapallito and connect this with the total leaves, leaves damaged and parasitoids at different monitoring dates, and determine the correlation between the number of larvae and parasitoids, according to the number of galleries per leaf. Six traps were placed in a commercial plot, and they were replaced weekly. The total and damaged leaves were recorded weekly in 15 randomly picked plants. Damaged leaves were taken to laboratory where galleries per leaf were counted. Each leaf with a gallery was placed in a Petri dish until leafminer or parasitoid adults emerged. Liriomyza huidobrensis caused damage in in early crop stages. There was correspondence between adult population and damage and number of galleries per leaf with significant differences in the first monitoring date, which was not found with parasitoids.

Los agromícidos causan daños en cultivos ornamentales y hortícolas. El objetivo de este estudio fue evaluar el número de adultos de L. huidobrensis en trampas pegajosas ubicadas en un cultivo de C. maxima var. zapallito, y relacionarlo con el total de hojas, hojas dañadas y parasitoides en diferentes fechas de monitoreo, y determinar la correlación entre el número de larvas y de parasitoides, de acuerdo a la cantidad de galerías por hojas. Seis trampas pegajosas fueron colocadas en un lote comercial y reemplazadas semanalmente. En 15 plantas seleccionadas al azar se registró el número total de hojas y el de hojas dañadas. Las hojas dañadas fueron llevadas a laboratorio donde se contó el número de galerías por hoja, y cada una fue colocada en cajas de Petri hasta la emergencia de los adultos del minador o del parasitoide. La población de adultos estuvo en correspondencia con el número de galerías por hoja con diferencias significativas en la primera fecha de monitoreo, pero no con los parasitoides.

ABSTRACT Background: In our country, the prevalence of type 2 diabetes (DT2) and cardiovascular risk factors (CVRF) increases continuously. Although the phenomenon is accompanied by the adoption of unhealthy lifestyles that facilitate such growth, there is little implementation of strategies that can modify the situation. Objective: To review the available evidence on the magnitude of the problem of diabetes and CVRF in our country, its possible relationship with the practice of physical activity and potential mechanism of action. Methodology: Evaluation of data from the Third National Survey of Risk Factors (ENFR) and information referred to factors that promote the prevalence growth of T2D. Additionally, successful strategies have been used worldwide for its prevention. Results: The body mass index registered in the studied population shows an increase in the percentage of people with overweight/obesity inverse to the practice of physical activity. Likewise, the results of the oral glucose tolerance tests show that their alterations (prediabetes/ diabetes) are lower among those who performed physical activity. The percentage of people with blood pressure values within the normal range as well as circulating cholesterol (according to target values of international guidelines), is also significantly lower among those who practiced physical activity. Conclusion: The presented evidence objectively demonstrates the need/advantages of implementing a large-scale diabetes primary prevention program at the national level to.

RESUMEN Antecedentes: En nuestro país la prevalencia de diabetes tipo 2 (DT2) y de factores de riesgo cardiovascular (FRCV) aumenta continuamente. Aunque el fenómeno se acompaña de adopción de estilos de vida no saludable que facilitan dicho crecimiento, es escasa la implementación de estrategias que puedan modificar la situación. Objetivo: Revisar la evidencia disponible sobre la magnitud del problema de la diabetes y los FRCV en nuestro país, su posible relación con la práctica de actividad física y potencial mecanismo de acción. Metodología: Evaluación de datos de la tercera Encuesta Nacional de Factores de Riesgo (ENFR) e información referida a factores que contribuyen al crecimiento de la prevalencia de DT2. Igualmente estrategias exitosas utilizadas a nivel mundial para su prevención. Resultados: El índice de masa corporal registrado en la población estudiada muestra un aumento del porcentaje de personas con sobrepeso/obesidad inverso a la práctica de actividad física. Igualmente los resultados de las pruebas de tolerancia a la glucosa oral muestran que sus alteraciones (prediabetes/diabetes) son menores entre quienes realizaban actividad física. El porcentaje de personas con valores de presión arterial dentro del rango normal al igual que de colesterol circulante (según valores meta de guías internacionales), es también significativamente menor entre quienes practicaban actividad física. Conclusión: La evidencia presentada demuestra objetivamente la necesidad/ventajas de implementar un programa de prevención primaria de diabetes a gran escala a nivel nacional para disminuir su crecimiento y la pertinencia de incluir la práctica de actividad física como estrategia de prevención tal como propone el PPDBA.

In this work, we present a study to determine the transit times and frequencies of pulses by using the Short-Time Fourier Transform (STFT). We consider the case of an acoustic signal composed of five Gaussian pulses that have a high overlapping in time but oscillate at different frequencies. We proceeded in three steps. First, we illustrate how the STFT calculated through a sliding window produces a spectrogram where transit time is on one axis and frequency on the other. Second, we derive an exact analytical solution of the STFT to develop an intuitive vision of the mathematical technique. Finally, in a third step, we present an experiment to demonstrate that the STFT is a useful technique to characterize a complex acoustical signal.

Background: Some SNPs related to lipid and energy metabolism may be implicated not only in the development of obesity and associated comorbidities, but also in the weight loss response after a nutritional intervention. Objective: In this context, the present study analyzed four SNPs located within four genes known to be associated with obesity and other obesity-related complications, and their putative role in a weight-loss intervention in overweight/obese adolescents. Methods: The study population consisted of 199 overweight/obese adolescents (13-16 yr old) undergoing 10 weeks of a weight loss multidisciplinary intervention: the EVASYON programme (www.estudioevasyon.org). Adolescents were genotyped for 4 SNPs, and anthropometric measurements and biochemical markers were analyzed at the beginning and after the intervention. Results: Interestingly, APOA5(rs662799) was associated with the baseline anthropometric and biochemical outcomes, whereas FTO (rs9939609) seemed to be related with the change of these values after the 10-week intervention. The other two SNPs, located in the CETP (rs1800777) and the APOA1 (rs670) genes, showed important relationships with adiposity markers. Specifically, a combined model including both SNPs turned up to explain up to 24% of BMI-SDS change after 10 weeks of the multidisciplinary intervention, which may contribute to understand the weight loss response. Conclusion: Common variants in genes related to lipid and energy metabolism may influence not only biochemical outcomes but also weight loss response after a multidisciplinary intervention carried out in obese/overweight adolescents.

Antecedentes: Algunas variantes genéticas relacionadas con el metabolismo lipídico y energético pueden estar implicadas en la respuesta a una intervención nutricional además de estar asociadas con el desarrollo de obesidad y comorbilidades asociadas. Objetivo: En este sentido, este artículo analiza cuatro polimorfismos situados en cuatro genes que han sido previamente asociados con la obesidad u otras complicaciones asociadas a la misma, así como su posible papel en la respuesta a una intervención para la pérdida de peso en adolescentes con sobrepeso u obesidad. Métodos: La población en estudio está formada por 199 adolescentes con sobrepeso u obesidad (13-16 años) llevando a cabo una intervención multidisciplinar de 10 semanas para la pérdida de peso: programa EVASYON (www.estudioevasyon.org). Los adolescentes fueron genotipados para los 4 SNPs y tanto al comienzo como al final de la intervención se analizaron marcadores bioquímicos y se tomaron medidas antropométricas. Resultados: Rs662799 del gen APOA5 se asoció al inicio con parámetros antropométricos y bioquímicos, mientras que el rs9939609 del gen FTO parecía estar asociado con el cambio de estas variables tras 10 semanas de intervención. Las variantes rs1800777 del gen CETP y rs670 del gen APOA1 mostraron una importante asociación con marcadores de adiposidad. Concretamente, un modelo combinado incluyendo los dos polimorfismos logró explicar hasta un 24% del cambio en el IMC-SDS tras 10 semanas de intervención. Conclusión: Variantes genéticas previamente relacionadas con el metabolismo lipídico y energético, pueden repercutir no solamente en valores bioquímicos sino también en la respuesta a una intervención multidisciplinar para la pérdida de peso en adolescentes con sobrepeso u obesidad.

Lifestyle changes such as following a hypocaloric diet and regular physical exercise are recognized as effective non-pharmacological interventions to reduce body fat mass and prevent cardiovascular disease risk factors. Purpose: To evaluate the interactions of a higher protein (HP) vs. a lower protein (LP) diet with or without a concomitant progressive resistance training program (RT) on body composition and lipoprotein profile in hypercholesterolemic obese women. Methods: Retrospective study derived from a 16-week randomized controlled-intervention clinical trial. Twentyfive sedentary, obese (BMI: 30-40 kg/m²) women, aged 40-60 with hypercholesterolemia were assigned to a 4-arm trial using a 2 x 2 factorial design (Diet x Exercise). Prescribed diets had the same calorie restriction (-500 kcal/day), and were categorized according to protein content as: lower protein (< 22% daily energy intake, LP) vs. higher protein (> 22% daily energy intake, HP). Exercise comparisons involved habitual activity (control) vs. a 16-week supervised whole-body resistance training program (RT), two sessions/wk. Results: A significant decrease in weight and waist circumference was observed in all groups. A significant decrease in LDL-C and Total-Cholesterol levels was observed only when a LP diet was combined with a RT program, the RT being the most determining factor. Interestingly, an interaction between diet and exercise was found concerning LDL-C values. Conclusion: In this study, resistance training plays a key role in improving LDL-C and Total-Cholesterol; however, a lower protein intake (< 22% of daily energy intake as proteins) was found to achieve a significantly greater reduction in LDL-C.

Cambios en el estilo de vida como el seguimiento de dieta hipocalórica y práctica de ejercicio físico regular, son reconocidos como intervenciones no farmacológicas efectivas para reducir la masa grasa y prevenir enfermedades cardiovasculares. Objetivo: Evaluar la interacción de dietas con mayor aporte proteico (HP) vs. menor aporte de proteínas (LP) con o sin un programa de entrenamiento de fuerza (RT) sobre la composición corporal, y el perfil lipídico en mujeres obesas con hipercolesterolemia. Metodología: Estudio retrospectivo derivado de un ensayo clínico controlado, aleatorizado de 16 semanas de intervención. 25 mujeres de entre 40-60 años, sedentarias, obesas (IMC: 30-40 kg/m²) y con hipercolesterolemia, fueron asignadas a 4 grupos, diseño factorial 2 x 2 (Dieta x Ejercicio). Las dietas, presentaban la misma restricción calórica (-500 kcal/day), y fueron categorizadas de acuerdo a su contenido proteico como: más bajas en proteínas (LP, < 22% del valor energético total) vs. más altas en proteínas (HP, > 22% del valor energético total). La comparación del ejercicio incluyó la actividad habitual (control) vs. 2 sesiones/sem de entrenamiento de fuerza supervisado, durante 16 semanas. Resultados: Se observaron pérdidas significativas de peso y de circunferencia de la cintura en todos los grupos. Disminución significativa de los niveles de LDL-C y colesterol total cuando la dieta LP era combinada con RT, siendo el RT el factor determinante. Se encontró una interacción entre dieta y ejercicio, en relación a los valores de LDL-C. Conclusión: En este estudio, el ejercicio de fuerza juega un papel importante en la reducción de los niveles de LDL-C y Colesterol total; sin embargo, una menor ingesta de proteínas (< 22% del valor energético total) puede favorecer mayor reducciones de LDL-C.

We have calculated the photonic band structure and the optical properties of two periodic layered systems, air/LiTaO3 and air/InSb, with the dielectric constant of the semiconducting medium taking into account the phononic contributions. Intrinsic electron and hole densities are also considered for the InSb. In addition to the photonic gaps originated by the structural configuration and the dielectric contrast (gaps by diffraction), there exist photonic gaps of metallic (polaritonic) behavior that appear at two frequency regions, just above the transverse phononic frequency and below the effective plasma frequency. We have found that the absorption mechanisms give rise to inflexion points in some bands - the curve of dispersion returns without reaching the Billouin zone limit. An infinite concentration of non-dispersive bands is found below the polaritonic gap when the absorption is neglected. However, with realistic absorption such infinite series of flat bands disappears, giving place to a finite number of dispersive bands.

En este trabajo presentamos un estudio sobre la Estructura de Bandas Fotónicas y las propiedades ópticas de dos sistemas multicapas distintos, aire/LiTaO3 y aire/InSb, para los cuales la constante dieléctrica del medio semiconductor toma en cuenta las contribuciones fonónicas. Las densidades intrínsecas de electrones y huecos son consideradas para el InSb. Además de las bandas fotónicas prohibidas originadas por la estructura geométrica y contrastes dieléctricos (brechas por difracción) existen bandas fotónicas prohibidas debido a la naturaleza metálica (polaritónica) de los componentes semiconductores. Estas brechas existen en dos regiones de frecuencias, a valores mayores de la frecuencia de resonancia fonónica y para valores menores de frecuencia de plasma efectiva. Hemos encontrado que los mecanismos de absorción dan lugar a puntos de inflexión en algunas bandas los cuales no llegan al límite de la primera zona de Brillouin. Por otra parte, para el caso en que no existe absorción, hemos encontrado una concentración infinita de bandas no dispersivas. Estas bandas están por debajo de la banda prohibida polaritónica. Sin embargo, cuando se considera un sistema realista en donde se incluyen los efectos de absorción del material semiconductor, la dispersión en las bandas da lugar a un número finito de bandas.

This work studies the effect of incorporating fluorescent organic extracts and oxide zinc nanoparticles in silica xerogel composites prepared by the sol-gel method, under different condition of preparation, which confer different optical and structural characteristics to product. The samples at room temperature and heat-treating at annealing temperature were studied using infrared spectroscopy, fluorescence, X-ray diffraction and differential temperature analysis.

The main objective of this work is to study the feasibility of new materials to be used as support for boron-nickel catalysts. Potential support materials such as: silica gel, alumina, hydrothermal modified Perlites and zeolite 4A, were characterized by BET, TPR and DRX. After the addition of Ni and B, their catalytic activity evaluated with the nitrobenzene hydrogenation model reaction. The influence of operational parameters during the impregnation process such as order of reactants, speed of agitation, time of aging and it influences from the previous thermal treatment were evaluated. The results show that the adequate materials to be used as catalysts supports are the commercial silica and Rehydroxilated Perlite. It is due to the existence of superficial OH groups, which allow the anchorage of the nickel boride catalyst.

In this paper we describe an application of the Finite Difference Time Domain (FDTD) method to simulate the propagation of the electromagnetic field in a homogeneous medium. The strategy of this method is to formulate the differential Maxwell equations in space and time finite differences in order to write a computational code. This work tries to motivate the undergraduate students to the numerical simulation of the electromagnetic wave propagation. We propose an interactive matlab code that with easy modifications is able to simulate different physical situations.

En este artículo se describe una aplicación del método de diferencias finitas en el dominio del tiempo (MDFDT) para simular la propagación del campo electromagnético en un medio homogéneo. La estrategia de este método se basa en escribir las ecuaciones diferenciales de Maxwell en una formulación discreta en el espacio y en el tiempo. El objetivo es trasladar esta formulación a un algoritmo que pueda ser resuelto numéricamente por medio de un código computacional. Este trabajo pretende motivar a los estudiantes a la simulación numérica de fenómenos electromagnéticos ondulatorios. Por medio de lenguaje Matlab generamos un código que, con modificaciones fáciles, permite obtener animaciones que simulan diferentes situaciones físicas.

ELISA was used to evaluate, accompany, and compare the humoral immune response of Swiss mice during hyperimmunization with native and Cobalt-60-irradiated (60Co) venoms of Bothrops jararaca, Bothrops jararacussu and Bothrops moojeni. Potency and neutralization were evaluated by in vitro challenges. After hyperimmunization, immunity was observed by in vivo challenge, and the side effects were assessed. The animals immunization with one LD50 of each venom occurred on days 1, 15, 21, 30, and 45, when blood samples were collected; challenges happened on the 60th day. Results showed that ELISA was efficient in evaluating, accompanying and comparing mouse immune response during hyperimmunization. Serum titers produced with natural venom were similar to those produced with irradiated venom. Immunogenic capacity was maintained after 60Co-irradiation. The sera produced with native venom showed neutralizing potency and capacity similar to those of the sera produced with irradiated venom. All antibodies were able to neutralize five LD50 from these venoms. Clinical alterations were minimum during hyperimmunization with irradiated venom, however, necrosis and death occurred in animals inoculated with native venom.

ELISA was used to evaluate, follow, and compare the humoral immune response of Swiss mice during hyperimmunization with natural and Cobalt 60-irradiated (60Co) Crotalus durissus terrificus venom. Potency and neutralization were evaluated by in vitro challenges. After hyperimmunization, immunity was observed by "in vivo" challenge and the side effects were assessed. The animals immunization with one LD50 of the venom was on days one, 15, 21, 30, and 45, when blood samples were collected; the challenges occurred on the 60th day. Results showed that ELISA was efficient in evaluating, following, and comparing mouse immune response during hyperimmunization. Serum titers produced with natural venom were similar to those produced with irradiated venom. Immunogenic capacity was maintained after 60Co irradiation. Serum produced from Crotalus durissus terrificus irradiated venom showed higher potency and neutralization capacity than that from natural venom. All antibodies were able to neutralize five LD50 from these venoms. Clinical alterations were minimum during hyperimmunization with irradiated venom.