ABSTRACT The rheological and nutritional properties of giant squid (Dosidicus gigas) surimi prepared by acid-saline leaching and the generation of a sol colloid with sodium citrate were evaluated. The application of 0.25, 1.27, 2.0, 3.0 and 7.0% sodium citrate produced a sol colloid from giant squid myofibrillar proteins. The addition up to 3.0% of sodium citrate presents a positive linear correlation with the properties of hardness and strength, from 2.0% there is a directly proportional increase with the modulus of elasticity of the gel. The addition of citrate as a cryoprotectant in the product did not improve the protective effect during storage at -20 °C for 72 hours. The replacement of NaCl by sodium citrate improved the texture of the surimi, a change that in terms of healthy eating contributes to the cleanliness of the nutritional label of the product by reducing its sodium content to 57.8% and not exceeding the limit of 800 mg/100 g of solid food.

RESUMEN Se evaluaron las propiedades reológicas y nutricionales en surimi de calamar gigante o pota (Dosidicus gigas) elaborado mediante lixiviación ácida-salina y la generación de un coloide sol con citrato sódico. La aplicación de 0.25, 1.27, 2.0, 3.0 y 7.0% de citrato sódico produjo un coloide sol a partir de las proteínas miofibrilares de calamar gigante. La adición hasta 3.0% de citrato sódico presenta una correlación lineal positiva con las propiedades de dureza y fuerza, y a partir de 2.0% se produce un incremento directamente proporcional con los módulos de elasticidad del gel. La adición de citrato como crioprotector en el producto no mejoró el efecto protector durante el almacenamiento a 20 °C por 72 horas. El reemplazo de NaCl por citrato sódico mejoró la textura del surimi, cambio que en términos de alimentación saludable contribuye con la limpieza de la etiqueta nutricional del producto al reducir su contenido de sodio a 57.8% y no superar el límite de 800 mg/100 g de alimento sólido.

Resumo A qualidade do solo é normalmente determinada pelas suas características físico-químicas sem ter em conta as comunidades bacterianas que desempenham um papel fundamental na decomposição química dos nutrientes das plantas. Neste contexto, o objetivo do estudo foi avaliar a diversidade bacteriana em solos de prados andinos elevados perturbados pelo cultivo de Lepidium meyenii sob diferentes gradientes de utilização (primeira, segunda e terceira utilizações) e desenvolvimento das culturas (pré-semeadura, desenvolvimento do hipocótilo e pós-colheita). A amostragem foi realizada no planalto de Bombón, nos Andes centrais do Peru, durante as estações das chuvas e das águas baixas, pelo método sistemático baseado num padrão específico atribuído em forma geométrica retangular a uma profundidade de 0 - 20 cm. A caracterização das comunidades bacterianas foi realizada através da sequenciação metagenômica do rRNA 16S. Foram relatadas 376 famílias de bactérias, das quais se verificou uma alteração significativa na composição e distribuição bacteriana em relação à pressão de utilização. Não se registaram grandes alterações devido ao desenvolvimento do Lepidium meyenii. As famílias mais sensíveis à utilização de indicadores de pressão e pobreza do solo foram as Verrucomicrobiaceae, Acidobacteraceae e Aakkermansiaceae.

Abstract Soil quality is usually determined by its physical-chemical characteristics without taking into account the bacterial communities that play a fundamental role in the chemical decomposition of plant nutrients. In this context, the objective of the study was to evaluate bacterial diversity in high Andean grassland soils disturbed with Lepidium meyenii cultivation under different gradients of use (first, second and third use) and crop development (pre-sowing, hypocotyl development and post-harvest). The sampling was carried out in the Bombón plateau in the central Andes of Peru, during the rainy and low water seasons, by the systematic method based on a specific pattern assigned in a geometric rectangular shape at a depth of 0 - 20 cm. The characterization of the bacterial communities was carried out through the metagenomic sequencing of the 16S rRNA. 376 families of bacteria were reported, of which it was determined that there was a significant change in bacterial composition and distribution in relation to use pressure. There were no major changes due to the development of Lepidium meyenii. The families most sensitive to use pressure and soil poverty indicators were Verrucomicrobiaceae, Acidobacteraceae and Aakkermansiaceae.

RESUMEN Introducción: Las consecuencias de la homofobia pueden afectar a la integridad y la salud mental y física de los individuos homosexuales en la sociedad. En Perú hay escasos estudios que hayan evaluado la homofobia en la población médico-estudiantil. Objetivo: Determinar los factores sociales, educativos y culturales asociados con la homofobia entre estudiantes de Medicina peruanos. Métodos: Se realizó un estudio de tipo transversal analítico en 12 sedes de Medicina humana peruanas. Se definió homofobia según un test validado, que se asoció con otras variables. Se obtuvieron estadísticos de asociación. Resultados: Las 4 universidades de Lima obtuvieron menores porcentajes de alumnos homofóbicos (15-20%) que las universidades del interior del país (22-62%). Al realizar el análisis multivariable, disminuyeron la frecuencia de homofobia: ser mujer (RPa = 0,74; IC95%, 0,610,92; p = 0,005), estudiar en una universidad de Lima (RPa = 0,57; IC95%, 0,43-0,75; p < 0,001), profesar la religión católica (RPa = 0,53; IC95%, 0,37-0,76; p < 0,001), conocer a un homosexual (RPa = 0,73; IC95%, 0,60-0,90; p = 0,003) y haber atendido a un paciente homosexual (RPa = 0,76; IC95%, 0,59-0,98; p = 0,036); en cambio, ser machista aumentó la frecuencia de homofobia (RPa = 1,37; IC95%, 1,09-1,72; p = 0,007), ajustado por 4 variables. Conclusiones: La homofobia fue menos frecuente entre las mujeres, los que estudiaban en la capital, los que profesan el catolicismo y los que conocen/han atendido a un homosexual; por el contrario, los machistas fueron más homofóbicos.

ABSTRACT Background: The consequences of homophobia can affect the integrity, mental and physical health of homosexual individuals in society. There are few studies in Peru that have evaluated homophobia in the medical student population. Objective: To establish the social, educational and cultural factors associated with homophobia among Peruvian medical students. Methods: A cross-sectional analytical study was conducted in 12 medicine schools in Peru. Homophobia was defined according to a validated test, which was associated with other variables. Statistical associations were identified. Results: The lowest percentages of homophobic students (15-20%) were found in the four universities in Lima, while universities in the interior of the country had the highest percentages (22-62%). Performing a multivariate analysis, we found that the frequency of homophobia was lower for the following variables: the female gender (PRa=0.74; 95% CI, 0.61-0.92; p=0.005), studying at a university in Lima (PRa=0.57; 95% CI, 0.43-0.75; p<0.001), professing the Catholic religion (PRa=0.53; 95% CI, 0.37-0.76;p<0.001), knowing a homosexual (PRa=0.73; 95% CI, 0.60-0.90; p=0.003) and having treated a homosexual patient (PRa=0.76; 95% CI, 0.59-0.98; p=0.036). In contrast, the frequency of homophobia increased in male chauvinists (PRa=1.37; 95% CI, 1.09-1.72; p=0.007), adjusted by four variables. Conclusions: Homophobia was less common in women, in those who study in the capital, those who profess Catholicism and those who know/have treated a homosexual. In contrast, male chauvinists were more homophobic.

Resumo: Introdução Peru provavelmente seja o país da região das Américas com uma maior incidência e prevalência de hidatidose cística; a infância é a etapa da vida onde geralmente adquire-se a infeção, pelo qual é importante o desenvolvimento de capacidades para sua prevenção. Objetivo Determinar o nível de conhecimento sobre hidatidose humana após a aplicação de um programa preventivo em crianças do ensino elementar (5° ano) de uma instituição educativa da localidade de Huancavelica. Metodologia Estudo quase experimental com pre e post teste a grupo experimental e controle, mostra 28 crianças em cada grupo que cumpriram critérios de seleção, amostragem não probabilística. Aplicou-se um questionário para medir conhecimentos sobre hidatidose humana e medidas preventivas, o programa esteve baseado no Modelo Didático Operativo de Bustos, empregando-se a “t” de Student para amostras em pares. Resultados O nível de conhecimento sobre hidatidose humana antes da intervenção educativa foi 50% entre médio e alto (17.5 ± 3.4); despois da intervenção 100% mostrou um nível alto (26.8 ± 1.9) p=0.001. O conhecimento sobre medidas preventivas da hidatidose humana antes da intervenção foi 25% baixo, 57.1% médio e 17.9% alto (5.5 ± 2.2); após a intervenção o nível foi 10.7% médio e 89.3% alto (9.1 ± 1.4) p=0.001; o grupo controle não evidenciou mudanças. Conclusões O programa preventivo foi eficaz, já que como resultado da intervenção apreciou-se uma melhora no conhecimento da hidatidose, assim como das medidas de prevenção para evitá-la.

Abstract: Introduction Peru is probably the country in the region of the Americas with the highest prevalence of cystic hydatidosis, and because during childhood is when the infection generally is acquired, it is important to develop strategies in order to prevent it. Objective To determine the level of knowledge about human hydatidosis after the implementation of an educational preventing program on children of the 5th grade at a school at Huancavelica, Peru. Methodology This is a quasi-experimental study with control and experimental groups and pre-post tests on a sample of 56 children (28 per group) who met the selection criteria. Sampling was non probabilistic. A questionnaire was given in order to assess the corresponding levels of knowledge, including that on the preventing measures. The program was based on the Operative Educational Model of Bustos. Paired Student’s t tests were calculated. Results The level of knowledge on human hydatidosis before the educational intervention was 50% between medium or high (17.5 ± 3.4), but after the program, 100% showed a high level of knowledge (26.8 ± 1.9) p=0.001. Specific knowledge on preventive measures before the intervention was 25% low, 57.1% medium, and 17.9% high (5.5 ± 2.2), and after the program, the levels were 10.7% medium and 89.3% high (9.1 ± 1.4) p=0.001. The control group did not show changes in the scores. Conclusions The educational program improved the knowledge on hydatidosis and its preventive measures.

Resumen: Introducción Perú probablemente sea el país de la región de las Américas con una mayor incidencia y prevalencia de hidatidosis quística; la niñez es la etapa de la vida donde generalmente se adquiere la infección, por lo que es importante el desarrollo de capacidades para su prevención. Objetivo Determinar el nivel de conocimiento sobre hidatidosis humana tras la aplicación de un programa preventivo en niñas/os del quinto de primaria de una institución educativa de la localidad de Huancavelica. Metodología Estudio cuasi experimental con pre y post prueba a grupo experimental y control, muestra 28 niñas/os en cada grupo que cumplieron criterios de selección, muestreo no probabilístico. Se aplicó un cuestionario para medir conocimientos sobre hidatidosis humana y medidas preventivas, el programa estuvo basado en el Modelo Didáctico Operativo de Bustos, empleándose la “t” de Student para muestras pareadas. Resultados El nivel de conocimiento sobre hidatidosis humana antes de la intervención educativa fue 50% entre medio y alto (17.5 ± 3.4); después de la intervención 100% mostró un nivel alto (26.8 ± 1.9) p=0.001. El conocimiento sobre medidas preventivas de la hidatidosis humana antes de la intervención fue 25% bajo, 57.1% medio y 17.9% alto (5.5 ± 2.2); tras la intervención el nivel fue 10.7% medio y 89.3% alto (9.1 ± 1.4) p=0.001; el grupo control no evidenció cambios. Conclusiones El programa preventivo fue eficaz, ya que como resultado de la intervención se apreció una mejoría en el conocimiento de la hidatidosis, así como de las medidas de prevención para evitarla.

Many complex phenomena favoring the solidification of metal that occur during the casting process, such as cast metal flow, thermal gradient and heat transfer between the cast metal and the mold. The grain size and mechanical properties of cast metal are defined by both these phenomena, and by the geometrical characteristics and thermo-physical properties of the metal and the mold. Heat loss from the mold to the environment through convection can also affect the mechanical properties of cast metal. In this study reported, two-dimensional numerical simulations were made of pure iron solidification in industrial AI 50/60 AFS greensand and mullite molds, using the finite element technique and the ANSYS software program. For this purpose, the iron's thermo-physical properties were considered dependent with temperature, while for sand and mullite these properties were considered constant, and the convection phenomenon was also considered on the mold's external surface. Metallurgical characteristics, such as the attack zone in the feed head and hot top were not taken into account in this study, since they are irrelevant the behavior of heat transfer of the metal to the mold. Owing to the iron's temperature-dependent thermo-physical properties, this type of problem is of nonlinear characteristic. The results of the heat transfer are shown in 2D, as well as, the thermal flux, the thermal gradient and the convergence curves that control the feasibility of the Newton-Raphson algorithm calculation process. The cooling curves at various points of the solidified specimen, and the heating and cooling curves in the mold were also shown. These results were considered relevant.

In the present study we have made the numeric simulation by finite elements of the cathodic protection by printed current system for the buried duct. The built model was based on the steel carbon type SAE-AISI 1015, and this steel is the constituent material of the duct. This work allowed analyzing the potential distribution in the proposed project and the parameters that more influence the variation of this potential. Those parameters were such as resistivity of the soil, distance between cathode and anode, position of the anode, potential and diameter of the cathode. As a result it was verified that the resistivity of the electrolyte and the distance cathode/anode influence significantly the distribution of the potential of the projected system of cathodic protection.

A durabilidade do varistor de ZnO está relacionada com suas características elétricas, microestruturais, térmicas e com o fenômeno de transporte de massa nos contornos de grão durante o processo de operação do varistor. O estado de polarização nos contornos de grão está relacionado com a difusão do zinco, do oxigênio e dos dopantes durante a aplicação do potencial elétrico e/ou da temperatura. Quando o potencial elétrico é retirado e o estado de polarização não recupera seu estado natural, significa que o dispositivo adquire os piores parâmetros e o varistor sofre degradação, comprometendo sua durabilidade. Neste trabalho, foi simulada a difusão do zinco intersticial e das vacâncias de oxigênio em ZnO. Foi também simulada a durabilidade do varistor, através do planejamento fatorial dos parâmetros elétricos, térmicos e geométricos que caracterizam o dispositivo. Através destes resultados, verificou-se que a difusão do zinco intersticial controla principalmente as propriedades elétricas. Observou-se, também, que quando aumenta a temperatura e a queda de tensão registrada em 0,5 mA/cm², a durabilidade do varistor fica comprometida.

The durability of the ZnO varistor is related with its electric, microstructural and thermal characteristics, and with the phenomenon of mass transport at grain boundaries under varistor operation. The polarization state at grain boundaries is related to the diffusion of zinc, oxygen and dopants during the application of the electric potential and/or of the temperature. When the electric potential is removed and the polarization state doesn't recover its natural state, the device presents the worst parameters and the varistor degrades, decreasing its lifetime. In this work, a simulation of the diffusion of interstitial zinc and of oxygen vacancy in ZnO varistor is done. In addition, the durability of the varistor was simulated, through the factorial design of electric, thermal and geometric parameters that characterize the device. It was found that the diffusion of the interstitial zinc controls mainly the electrical properties of the varistor. It was also observed that when the temperature is increased and the tension drops to 0.5 mA/cm², the lifetime of the varistor decreases.