ABSTRACT In recent years, the high consumption of non-renewable natural resources and energy associated with the generation of solid waste has encouraged the development of sustainable materials for civil construction. In this context, some studies on the use of polymeric residues in the formulation of concrete-based materials have been published. These residues can minimize the use of mineral aggregates, in addition to providing some desired properties to the materials obtained. Porosity is one of the most important parameters of the concrete microstructure, as it is intrinsically related to some properties of this material, such as compressive strength. The objective of this work is to evaluate the properties and porosity of a concrete formulated with different contents of poly(ethylene terephthalate) (PET) obtained from mooring cables of discarded oil platforms. The characterization of the polyester waste by different techniques showed that residue from mooringropes is comprised of PET. The mechanical evaluation of the concretes was performed by compression strength tests. The results showed that the addition of 5 % PET to the concrete formulations has a tendency to improve the mechanical strength of the materials. The porosity of each concrete sample was determined from images acquired from commercial scanner. Empirical equations were applied to relate the porosity data obtained to the compressive strength of the samples. The curves obtained matching with the inverse relationship between these two parameters.

RESUMO A incorporação de resíduos e a redução do teor de agregados minerais em formulações de concreto são ações que contribuem para a preservação ambiental. O objetivo desse estudo é desenvolver e avaliar as propriedades e a porosidade de concretos formulados com resíduos, provenientes de cabos usados em linhas de amarração de plataformas de petróleo. Com essa finalidade, os resíduos foram caracterizados utilizando técnicas tradicionalmente utilizadas em materiais. Corpos de prova de concretos de traço padrão 1,0: 2,3: 2,7: 0,55 (cimento: areia: brita: água) (NBR 5738) foram preparados e usados como referência. Para avaliar o efeito da incorporação dos resíduos no desempenho dos concretos, corpos de prova com teores de substituição parcial de 5% e 10% do agregado miúdo por resíduos foram preparados, e submetidos a ensaios de resistência à compressão axial (NBR 5739) e de absorção de água (NBR 778). A porosidade dos concretos foi determinada a partir de imagens obtidas em escâner comercial. Os resultados mostraram que os resíduos eram constituídos por poli (tereftalato de etileno), PET. O concreto formulado com teor de substituição de agregado miúdo por 5% de PET apresentou leve tendência ao aumento da resistência. A substituição de 10% do agregado por PET, entretanto, reduziu a resistência do concreto. Os valores de porosidade do concreto de referência e do formulado com substituição de 5% de agregado por PET apresentaram relação condizente com os valores de resistência à compressão. A metodologia adotada se mostrou satisfatória para a determinação de poros do tipo vazios de ar presentes na estrutura do concreto. As curvas de resistência versus porosidade baseadas nos modelos de Powers e Riyshkevitch demonstraram que essa metodologia pode ser utilizada para determinar a resistência à compressão de concretos com porosidade menor que 20%. O concreto formulado substituindo o agregado miúdo por 5% de PET apresenta resistência compatível com a do material de referência.

Abstract The objective of the study was to analyze the factors that determine the use of free pollination varieties of sorghum in the north of the state of Sinaloa, in order to characterize the type of producers that use this type of seeds. A discrete choice model was utilized to identify the factors that influence the adoption of sorghum by 199 farmers. Later, adopters (n= 11) and non-adopters (n= 188) of the technology were characterized based on non-parametric tests. The results show that 5.5 % of the producers have adopted sorghum varieties. The number of years with technical assistance and milk production were significant (P<0.05) for the adoption. Also, the characterization of the farmers showed that those who have more resources-infrastructure, machinery, livestock, land, wages and technical assistance, -were the ones who adopted the varieties of sorghum. It is concluded that the adoption of seeds is low and requires public goods, such as agricultural outreach programs, for the dissemination of its benefits to allow greater appropriation by farmers in the region of study.

Resumen El objetivo del estudio fue analizar los factores que determinan el uso de variedades de polinización libre de sorgo en el norte del estado de Sinaloa, con la finalidad de caracterizar el tipo de productores que utilizan este tipo de semillas. Se utilizó un modelo de elección discreta para identificar los factores que inciden en la adopción de sorgo de 199 ganaderos. Posteriormente, a través de pruebas no paramétricas se caracterizaron los adoptadores (n= 11) y no adoptadores (n= 188) de la tecnología. Los resultados muestran que 5.5 % de los productores han adoptado variedades de sorgo. El número de años con asistencia técnica y la producción de leche resultaron significativas (P<0.05) para la adopción. En tanto, la caracterización de los ganaderos mostró que aquellos que cuentan con mayor cantidad de recursos: infraestructura, maquinaria, ganado, tierra, jornales y asistencia técnica, son los que adoptaron las variedades de sorgo. Se concluye que la adopción de semillas es baja y necesita de bienes públicos, como la extensión agrícola, para la difusión de sus beneficios que permita una mayor apropiación de los ganaderos en la región de estudio.

Background: In December 2019, coronavirus disease 2019 (COVID-19) emerged in Wuhan city and spread rapidly throughout China and the world. Aim: To describe the clinical features, risk factors, and predictors of hospitalization in adult patients treated for acute respiratory infections associated with coronavirus SARS-CoV-2. Material and Methods: Descriptive prospective study of ambulatory and hospitalized adult patients with confirmed COVID-19 attended between April 1 and May 31, 2020. Clinical features, chronic comorbidities and demographic data were recorded, and patients were followed for two months as outpatients. Results: We assessed 1,022 adults aged 41 ± 14 years (50% men) with laboratory-confirmed COVID-19. One-third had comorbidities, specially hypertension (12.5%), hypothyroidism (6.6%), asthma (5.4%) and diabetes (4.5%). Hospital admission was required in 11%, 5.2% were admitted to critical care unit and 0.9% were connected to mechanical ventilation. Common symptoms included fatigue (55.4%), fever (52.5%), headache (68.6%), anosmia/dysgeusia (53.2%), dry cough (53.4%), dyspnea (27.4%) and diarrhea (35.5%). One third of patients reported persistence of symptoms at one-month follow-up, specially fatigue, cough and dyspnea. In the multivariate analysis, age, fever, cough, dyspnea and immunosuppression were associated with hospitalization and ICU admission. Age, male sex and moderate-severe dyspnea were associated with requirement of mechanical ventilation. The main predictors of prolonged clinical course were female sex, presence of comorbidities, history of dyspnea, cough, myalgia and abdominal pain. Conclusions: Clinical features of COVID-19 were highly unspecific. Prediction models for severity, will help medical decision making at the primary care setting.

ABSTRACT Juvenile giant fibroadenoma is a benign breast tumor and a rare variant of fibroadenomas. The clinical presentation is usually a painless, fast growing, unilateral tumor mass. In this article we present the case of a giant juvenile fibroadenoma of 12 cm in diameter in the breast of a 13-year-old girl. A radiological and histological study of the lesion was carried out and it was categorized as a juvenile giant fibroadenoma, so a complete lumpectomy with posterior breast remodeling was performed. After two months of follow-up, the patient is without signs of recurrence, in good general condition and waiting for the breast remodeling surgery.

RESUMEN El fibroadenoma gigante juvenil es un tumor de mama benigno y una variante rara de los fibroadenomas. La presentación clínica suele ser una masa tumoral unilateral, de crecimiento rápido e indolora. En este artículo presentamos el caso de un fibroadenoma gigante juvenil de 12 cm de diámetro en la mama de una niña de 13 años. Se realiza estudio radiológico e histológico de la lesión siendo categorizada como un fibroadenoma gigante juvenil por lo que se realiza tumorectomía completa con remodelación mamaria posterior. A los dos meses de seguimiento, la paciente se encuentra sin signos de recidiva, con buena situación general y a la espera de cirugía de remodelación mamaria.

RESUMEN La contaminación ambiental por metales pesados constituye un problema mundial contemporáneo. El desarrollo de estrategias biotecnológicas en el campo de la remediación ha ganado gran atención en los últimos años por ser más rentables, eficientes y amigables con el medio ambiente. Las bacterias resistentes a metales pesados constituyen una herramienta potente en la biorremediación de ambientes contaminados por metales. Este trabajo tuvo como objetivo caracterizar bacterias resistentes a metales pesados, aisladas de un escombro laterítico, residual de la industria minera de Moa. Se aislaron dos bacterias (EL-1 y EL-2) a partir del escombro laterítico. Los aislados se caracterizaron e identificaron hasta el nivel de género. Se evaluó la resistencia a níquel, cobalto, cromo y aluminio en medio mínimo Tris sólido. Se determinó la curva dosis-respuesta a níquel, cobalto, cromo y aluminio, así como el mecanismo de resistencia bacteriana a níquel. Además, se evaluó la susceptibilidad a antibióticos. Los dos aislados fueron identificados como Bacillus sp. Las cepas fueron resistentes a todos los metales evaluados, mostrando una alta resistencia a níquel (25 mmol-L-1). La cepa Bacillus sp. EL-1 presentó un mecanismo inducido de resistencia a níquel, mientras que la cepa Bacillus sp. EL-2 presentó una expresión constitutiva de la resistencia a este metal. Las bacterias mostraron un predominio de la sensibilidad a los antibióticos evaluados. Todas estas características las hacen interesantes para ser aplicadas en estrategias de biorremediación para el saneamiento ambiental.

ABSTRACT Environmental pollution by heavy metals is a contemporary world problem. Developing biotechnological strategies in remediation field has gained great attention in recent years for being more profitable, efficient and friendly to the environment. Heavy metal resistant bacteria are a powerful tool in bioremediation of metal contaminated environments. The aim of this study is to characterize heavy metal resistant bacteria, isolated from lateritic rubble, residual from Moa mining industry. Two bacteria (EL-1 and EL-2) were isolated from the lateritic rubble. The isolated ones were characterized and identified down to gender level. Resistance to nickel, cobalt, chromium and aluminum was evaluated in solid Tri minimal medium. The dose-response curve for nickel, cobalt, chromium and aluminum was determined, as well as the mechanism of bacterial resistance to nickel. In addition, antibiotic susceptibility was assessed. The two isolated were identified as Bacillus sp. The strains were resistant to all the evaluated metals, showing a high resistance to nickel (25 mmol-L-1). The Bacillus sp. EL-1 showed an induced mechanism of nickel resistance, while the Bacillus sp. EL-2 showed a constitutive resistance to this metal. The bacteria showed a predominance of sensitivity to the antibiotics evaluated. All these characteristics make them interesting to be applied in bioremediation strategies for environmental cleanup.

ABSTRACT: This article presents the results of an academic training experience in Community Psychology that has been ongoing since 2013 at a Chilean private university located in the city of Santiago. This ongoing experience was implemented through an institutional agreement with the Independencia municipality (urban area of Santiago) and has focused on the increasingly large migrant population present in this district. The experience is described considering the institutional framework made possible by the learning and service policy of the university, the educational approach adopted by the teaching team, and the assessment of all the local actors involved. This proposal is described through the documentary review and analysis of several written sources, 8 individual interviews with community members and municipality workers, 2 focus groups with students, and 14 surveys administered to teachers and students. Purposive sampling was used. The information is analyzed qualitatively using thematic analysis. Results describe the development of the training project within an institutional framework defined through a public policy that takes advantage of the migration context to implement interventions at a local level, thus responding to the social demands derived from the phenomenon.

RESUMEN: Se presentan los resultados de una experiencia de formación académica en psicología comunitaria, en desarrollo desde el año 2013 en una universidad privada chilena ubicada en la ciudad de Santiago. Dicha experiencia, en curso, se ha implementado mediante la vinculación institucional con el municipio de Independencia (área urbana de Santiago) y se ha orientado hacia el trabajo con la población migrante crecientemente avecindada en dicha localidad. La experiencia se describe tanto en base al marco institucional posibilitado por la política de aprendizaje y servicio de la universidad, como por la propuesta pedagógica asumida por el equipo docente y la evaluación de los actores locales involucrados. La descripción de esta propuesta, se realiza a través de la revisión y análisis documental de información proveniente de diversas fuentes escritas, 8 entrevistas individuales a miembros de la comunidad y funcionarios municipales, 2 grupos focales a estudiantes y 18 cuestionarios aplicados a docentes y estudiantes, mediante un muestreo intencionado. La información es analizada cualitativamente, mediante la técnica de análisis temático. Los resultados describen el desarrollo del proyecto formativo en un marco institucional definido desde una política pública que aprovecha el contexto de migración para liderar acciones de intervención en el ámbito local, atendiendo a las demandas sociales vinculadas al fenómeno.

Abstract Background: semantic networks allow to define a mental model structure showing the underlining culture. It can help to find Mexico City’s dwellers representation about the subjective well-being. Objective: the aim was to obtain a culturally relevant definition of subjective well-being with semantic networks, psychological and graph theories. Method: using semantic networks define well-being, satisfaction and happiness. The sample (N = 207) were volunteers, men and women (52%), dwellers of Mexico City, older than 18 years of age (x̅ = 35.62 years). Analysis included linear and nonlinear measures. Results: the well- being, happiness and satisfaction differentiated and complemented each other with dimensions (relationships, basic needs, resources) and components (emotion affect). The weighted frequencies highlighted salience of words health, calmness, family, happiness, peace. The geodesic distances remained short with the highest betweenness-centrality for health, calmness, work, happiness, satisfaction and security. Discussion and conclusions: the subjective well-being components and dimensions expected from the theory were found with the semantic networks. Happiness and satisfaction added the affect component. The geodesic distances were short and organized into five main modules: health, family, work and calmness. The representation converged the proposed elements of both the theory and the ones from inhabitants of Mexico City, into a culturally relevant definition.

Resumen Antecedentes: las redes semánticas muestran la estructura de conceptos culturalmente relevantes que forman modelos mentales, como puede ser la representación del bienestar subjetivo para la CDMX. Objetivo: Obtener una definición de bienestar subjetivo culturalmente relevante con la aplicación de la técnica de redes semánticas, teoría psicológica y de grafos. Metodología: aplicación de redes semánticas para los conceptos bienestar, satisfacción y felicidad. La muestra (N = 207) hombres y mujeres (52%), mayores de edad (x̅ = 35.62 años) y habitantes de la CDMX. Se analizó con distancias lineales y no lineales. Resultados: bienestar, felicidad y satisfacción se diferenciaron y complementaron con dimensiones (relaciones significativas, necesidades básicas, recursos y emociones positivas) y componentes (afectivo y cognoscitivo). La ponderación mostró la relevancia de salud, tranquilidad, familia, felicidad, y paz que complementó las distancias geodésicas con mayor centralidad (salud, tranquilidad, trabajo, felicidad, satisfacción y seguridad). Discusión y conclusiones: hubo la presencia de componentes y dimensiones del bienestar subjetivo con afectos y emociones de los conceptos felicidad y satisfacción. Se dio una red geodésica compacta con cinco módulos principales, y salud, familia, trabajo y tranquilidad fueron los de mayor centralidad. La representación converge lo propuesto en la teoría y la definición culturalmente relevante de los habitantes de la CDMX.

Abstract Hypertension is considered a risk factor for coronary heart disease, and its prevalence has increased substantially. Inhibition of angiotensin-converting enzyme (ACE-I) is key to lower blood pressure, making it an excellent treatment for hypertension. Corn (Zea mays L.) is an important source of bioactive peptides with potential anti-hypertensive activity related to ACE-I inhibition. These peptides can be obtained through the hydrolysis of corn gluten meal (CGM), as wet-milling by-products. The aim was to evaluate the in vitro and in vivo ACE-I inhibitory activity of blue CGM hydrolysates. Enzymatic digestion in vitro of blue CGM was conducted at different times. Hydrolysis for 360 min significantly increased both soluble protein and antioxidant activity by 4 and 8-fold respectively, the maximum ACE-I inhibition (94.3 %) was observed with 260 min hydrolysate. Mice were treated with the blue CGM hydrolysate (260 min), captopril or PBS to test the bioavailability in vivo. The CGM hydrolysate was detected in serum after 5 and up to 30 min after ingestion, showing the maximum ACE-I inhibitory capacity (59 %) during the first 15 min. Overall, this work showed that the blue CGM hydrolysate could serve as a functional food ingredient with antihypertensive effect due to its blood pressure-lowering peptides.

Resumen La hipertensión es factor de riesgo en enfermedades coronarias, y su prevalencia ha aumentado sustancialmente. La inhibición de enzima convertidora de angiotensina (ECA) es clave para disminuir presión arterial, y excelente tratamiento para hipertensión. El maíz (Zea mays L.) es fuente de péptidos bioactivos con actividad antihipertensiva por inhibición de ECA. Péptidos pueden obtenerse por hidrólisis de harina de gluten de maíz (HGM), como subproducto de molienda húmeda. El objetivo fue evaluar in vitro e in vivo actividad inhibitoria de ECA en hidrolizados de HGM azul. La digestión enzimática in vitro de HGM fue conducida a diferentes tiempos. La hidrólisis por 360 min aumento significativamente proteína soluble y actividad antioxidante de 4 y 8 veces, respectivamente; la máxima inhibición de ECA (94.3%) fue observada a 260 minutos del hidrolizado. Ratones fueron tratados con HGM hidrolizado (260 minutos), captopril o PBS para evaluar biodisponibilidad in vivo. Después de la ingestión, HGM hidrolizado fue detectado en suero en 5 hasta 30 minutos, mostrando máxima inhibición de ECA (59 %) durante los primeros 15 minutos. En general, este trabajo mostró que hidrolizado de HGM podría servir como ingrediente funcional en alimentos con efecto antihipertensivo debido a péptidos reductores de presión arterial.

Abstract From the perspective of the capacities of Amartya Sen and the autonomy of Doyal and Gough, it is sought to know the productive practices with ICTs in university students because it is assumed that they can expand their capacities to take opportunities and participate in social life. Through a documentary method, a corpus of 59 scientific documents from 20 countries, published between 2010 and 2018, was analyzed to characterized the social practices with ICTs in young university students. Practices for learning, citizenship, communication and prosumerism were found; cellphone and social networks were identified as preferred technologies versus the Internet and the personal computer. In addition, it was possible to define the productive techno-practices on the frame of human development for these young students.

Resumen Desde la perspectiva de las capacidades de Amartya Sen y de la autonomía de Doyal y Gough, se busca conocer las prácticas productivas con las tecnologías de la información y la comunicación (TIC) en los jóvenes universitarios, porque se asume que estas pueden expandir sus capacidades para aprovechar las oportunidades y participar en la vida social. A través de un método documental se analizó un corpus de 59 documentos científicos de 20 países, publicados entre 2010 y 2018, para caracterizar las prácticas sociales con las TIC que realizan los jóvenes universitarios. Se encontraron prácticas para el aprendizaje, la ciudadanía, lo comunicativo y el prosumismo, y se identificó la emergencia del teléfono celular y las redes sociales como las tecnologías preferentes de uso frente a la difuminación del internet y la computadora. Además, se lograron definir las tecnoprácticas productivas de cara al desarrollo humano de estos jóvenes.

Abstract: Community psychology approaches the study of leadership from a critical perspective, revealing its potential of transforming social reality within the framework of the processes of associativity and social exchange. In order to know the public perception about leadership and public policies, during 2017, we developed and applied a questionnaire to a sample of 247 people between 20 and 75 years of age, residents of the Metropolitan and Valparaíso regions. Its aim was to know the citizens’ perception based on the representations, meanings and assessment of the leadership in current public policies. The analysis of the quantitative data included the use of descriptive statistics and, for the qualitative data, we worked with the guidelines of the theory of the central nucleus of social representations. The results show little recognition of the public policy of leadership. Meanings and assessments associated with group and horizontal leadership were observed, while their representations are fundamentally of an individual type. We discuss the possibility of constructing new views of the leadership from public policy, enhancing it as a collective and transformative process.

Resumen: La psicología comunitaria aborda el liderazgo desde una perspectiva crítica, relevando su potencial transformador de la realidad social, en el marco de los procesos de asociatividad e intercambio social. Con el objetivo de conocer la percepción ciudadana en torno a la inclusión del liderazgo en planes, programas y proyectos de políticas públicas en Chile, durante el año 2017, elaboramos y aplicamos un cuestionario a una muestra de 247 personas entre 20 y 75 años, residentes de las regiones Metropolitana y de Valparaíso. Su objetivo fue conocer la percepción con base en las representaciones, significados y valoración del liderazgo implementados en las políticas públicas actuales. El análisis de los datos cuantitativo incluyó uso de estadísticos descriptivos y, para los cualitativos, se trabajó con los lineamientos de la teoría del núcleo central de las representaciones sociales. Los resultados muestran un escaso reconocimiento de la inclusión del tema del liderazgo en la política pública. Se observaron significados y valoraciones asociadas a un liderazgo de tipo grupal y horizontal, mientras que sus representaciones son fundamentalmente de tipo individual. Se discute la posibilidad de construir nuevas miradas del liderazgo desde la política pública, potenciándolo como un proceso colectivo y transformador.