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Chronic Myeloid Leukemia is a blood cancer for which standard therapy with Tyrosine-Kinase Inhibitors is successful in the majority of patients. After discontinuation of treatment half of the well-responding patients either present undetectable levels of tumor cells for a long time or exhibit sustained fluctuations of tumor load oscillating at very low levels. Motivated by the consequent question of whether the observed kinetics reflect periodic oscillations emerging from tumor-immune interactions, in this work, we analyze a system of ordinary differential equations describing the immune response to CML where both the functional response against leukemia and the immune recruitment exhibit optimal activation windows. Besides investigating the stability of the equilibrium points, we provide rigorous proofs that the model exhibits at least two types of bifurcations: a transcritical bifurcation around the tumor-free equilibrium point and a Hopf bifurcation around a biologically plausible equilibrium point, providing an affirmative answer to our initial question. Focusing our attention on the Hopf bifurcation, we examine the emergence of limit cycles and analyze their stability through the calculation of Lyapunov coefficients. Then we illustrate our theoretical results with numerical simulations based on clinically relevant parameters. Besides the mathematical interest, our results suggest that the fluctuating levels of low tumor load observed in CML patients may be a consequence of periodic orbits arising from predator-prey-like interactions.

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4-(2-furyl)-3-buten-2-one (FAc) is obtained by aldol condensation of furfural and acetone and has been used in hydrodeoxygenation reactions to obtain fuel products using noble metal catalysts. The hydrogenation of FAc in the aqueous phase using metallic- and Re oxide-supported catalysts on graphite was studied, within a temperature range of 200-240 °C, in a batch reactor over a 6 h reaction period. The catalysts were characterized using N2 adsorption-desorption, TPR-H2, TPD-NH3, XRD, and XPS analyses. Catalytic reactions revealed that metallic rhenium and rhenium oxide-supported catalysts are active for the hydrogenation and Piancatelli rearrangement of FAc. Notably, metallic rhenium exhibited a fourfold higher initial rate than rhenium oxide, which was attributed to the higher dispersion of Re in the Re/G catalyst over graphite. Re/G and ReOx/G catalysts tended to rearrange and hydrogenate FAc to 2-(2-oxopropyl)cyclopenta-1-one in water.

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Resumen Los sistemas agroforestales pueden representar importantes nichos ecológicos que coadyuven a la conservación de la diversidad avifaunística. El objetivo de este trabajo fue estimar y comparar la diversidad y uso de hábitat de aves insectívoras en sistemas agroforestales enclavados en un bosque mesófilo de montaña. Se efectuó el monitoreo de aves de agosto de 2018 a enero de 2019 en tres hábitats: café tradicional (CT), potrero (PT) y bosque mesófilo de montaña (BMM). Se determinaron índices de abundancia relativa (IAR), riqueza (Jacknife1), similitud (Jaccard) y diversidad (Shannon-Wiener). El IAR presentó valores bajos para los tres hábitats. El método Jacknife1 denotó una riqueza promedio considerable para las tres áreas (CT: 33.02, PT: 24.20, BMM: 9.98, CT-PT-BMM: 52.22). La técnica de Jaccard registró poca similitud en la riqueza, reafirmando el efecto del hábitat, composición y estructura florística como factores determinantes, al mismo tiempo que estableció promedios de diversidad alta obtenidos mediante el método de Shannon-Wiener (H´= 3.3; 3.1; 2.27; 3.78, respectivamente), revelando una diversidad relativamente estable en los tres hábitats. Por su parte, Kruskal-Wallis advirtió diferencias en la diversidad, pero no para la riqueza y la abundancia. Se evidenció la conformación declústeresy agrupaciones que encontraron mayor similitud entre la riqueza y la abundancia de especies por cada monitoreo aplicado. El análisis de componentes principales indicó mayor correlación del hábitat y la vegetación utilizados para la alimentación en el estrato herbáceo y arbóreo, en alturas que van de 5 m a 10 m, utilizando el estrato aéreo para vuelo. Los sistemas agroforestales estudiados constituyeron un nicho de oportunidad en donde la avifauna halló alimento, áreas de nidación y reproducción. Se recomienda la implementación de buenas prácticas de manejo agroforestal que coadyuven a la conservación de especies.

Abstract Agroforestry systems can represent important ecological niches that contribute to the conservation of bird diversity. The objective of this work was to estimate and compare the diversity and habitat use of insectivorous birds in agroforestry systems located in a montane cloud forest. Bird monitoring was carried out from August 2018 to January 2019 in three habitats: traditional coffee plantation (CT), paddock (PT) and montane cloud forest (BMM). Relative abundance (IAR), richness (Jacknife1), similarity (Jaccard) and diversity (Shannon-Wiener) indices were determined. The IAR presented low values for the three habitats. The Jacknife1 method denoted considerable average richness for the three areas (CT: 33.02, PT: 24.20, BMM: 9.98, CT-PT-BMM: 52.22). The Jaccard technique recorded little similarity in richness, reaffirming the effect of habitat, composition and floristic structure as determining factors, which at the same time established high diversity averages, obtained by the Shannon-Wiener method (H´= 3.3; 3.1 ; 2.27; 3.78, respectively), revealing a relatively stable diversity in the three habitats. For his part, Kruskal-Wallis noticed differences in diversity, but not for richness and abundance. The formation of clusters and groups that found greater similarity between the richness and abundance of species for each applied monitoring was evidenced. Principal component analysis indicated a higher correlation of habitat and vegetation used for feeding in the herbaceous and arboreal stratum, at heights ranging from 5 m to 10 m, using the aerial stratum for flight. The agroforestry systems studied constituted a niche of opportunity where the avifauna found food, nesting and reproduction areas. The implementation of good agroforestry management practices that contribute to the conservation of species is recommended.

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Durante los últimos años se ha incentivado la suplementación con omega 3 durante el embarazo principalmente debido a la evidencia que mostraría beneficios en el desarrollo neuronal y visual del hijo en gestación, y a la prevención de patologías obstétricas asociadas a un aumento de la morbi-mortalidad perinatal. Los ácidos grasos poliinsaturados (PUFAs) omega 3, específicamente el ácido eicosapentaenoico (EPA) y el ácido docosahexaenoico (DHA), poseen propiedades antiinflamatorias, vasodilatadoras, además de propiedades anti-agregantes, las cuales han estimulado el uso de PUFAs en la prevención de enfermedades cardiovasculares. En esta revisión detallamos los efectos de la suplementación con omega 3 en diferentes aspectos del embarazo tales como la prevención del parto prematuro, preeclampsia, depresión post-parto y mejora del metabolismo durante la diabetes gestacional. Si bien existen diversos ensayos clínicos randomizados que estudian la suplementación con omega 3 durante la gestación, la evidencia sigue siendo no concluyente, debido a la variabilidad de las dosis y tiempo de administración. Ciertamente, un mayor número de estudios de calidad son necesarios para determinar el real impacto de la suplementación con omega 3 durante la gestación en la prevención de patologías obstétricas(AU)

During pregnancy, omega 3 supplementation has raised its popularity due to evidence that it would show not only benefits in the neural and visual development of the unborn child, but also in the prevention of obstetrical pathologies associated with of perinatal morbidity and mortality. Omega 3 polyunsaturated fatty acids (PUFAs), specifically, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), possess anti-inflammatory, vasodilatory and anti-aggregating properties, which have led to the use of PUFAs in the prevention of cardiovascular diseases. In this review, we detail the effects of omega 3 supplementation on different aspects of pregnancy such as prevention of preterm birth, pre-eclampsia, postpartum depression, and improved metabolism during gestational diabetes. Although there are several randomized clinical trials using omega-3 supplementation during pregnancy, the evidence remains inconclusive, due to variability in dosage and administration time. Certainly, a greater number of high-quality studies including randomized clinical trials are necessary to determine the impact of omega 3 supplementation during pregnancy in the prevention of obstetric pathologies(AU)

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OBJECTIVE: The purpose of the current study was to cross-culturally adapt and validate an online questionnaire to assess eating habits and physical activity of university students under confinement due to coronavirus disease (COVID-19). DESIGN: Generation of a cross-sectional online survey to university students conducted during confinement due to COVID-19. The study was divided into two phases. SETTINGS: Students, Chile. PARTICIPANTS: Phase 1 considered the process of translation and back translation, expert panel, cultural adaptation and the generation of a pilot to validate a preliminary format of the questionnaire. In Phase 2, information from the instrument was collected from two hundred and sixty-eight university students, ages 16 to 30 years old, with a mean age of 21·6 (3·3) The major proportion of participants were female (82 %). RESULTS: The adapted questionnaire was statistically validated in three dimensions: (A) eating habits and behaviours during quarantine, (B) perception of risk and (C) physical activity changes during the quarantine. The reliability of Cronbach's α for dimensions A, B and C was 0·59, 0·85 and 0·97, respectively. The complete questionnaire obtained 0·61 in internal consistency and 0·61 (0·58-0·67) ICC reliability. A statistically significant positive correlation matrix was observed. CONCLUSIONS: This questionnaire is a practical tool to obtain accurate information about the relation of COVID-19 confinement on people's eating habits and physical activity. Therefore, it could contribute to establishing appropriate strategies to prevent negative effects on people's health.

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Resumen Introducción: El distanciamiento social y la cuarentena han probado tener efectos negativos en la salud mental de las poblaciones, a saber: miedo, ansiedad, depresión y sintomatología de estrés postraumático. La resiliencia emerge como variable amortiguadora del impacto. El objetivo del estudio fue comparar el impacto psicológico del COVID-19 en varios países latinoamericanos. Método: se obtuvo una muestra de 1184 participantes de México, Cuba, Chile, Colombia y Guatemala; cuya edad osciló entre 18 y 83 años (M = 38.78, DT = 13.81). Se aplicó una encuesta sobre síntomas médicos asociados al COVID-19 con tres instrumentos para evaluar: (1) síntomas de depresión, ansiedad y estrés, (2) impacto del evento y (3) resiliencia. Resultados: Las personas más jóvenes, con mayor cantidad de síntomas médicos y con mayores puntajes de impacto del evento tienden a presentar mayor sintomatología depresiva, ansiosa y estrés, siendo el impacto del evento el predictor más determinante. La resiliencia fue el predictor protector contra la depresión, ansiedad y estrés. Conclusiones: Los resultados muestran las diferencias en la respuesta psicológica ante la pandemia del COVID-19 en cada país, y sugieren la necesidad del desarrollo de políticas públicas enfocadas en la prevención y la promoción de la salud integral ante emergencias sanitarias.

Abstract Introduction: Social distancing and quarantine have proven to have negative effects on the mental health of populations, namely fear, anxiety, depression and post-traumatic stress symptoms. Resilience emerges as a buffering variable for such impact. The objective of this study was to compare the psychological impact of COVID-19 in several Latin American countries. Method: A sample of 1184 participants from Mexico, Cuba, Chile, Colombia and Guatemala was obtained; whose age ranged from 18 to 83 years old (M = 38.78, SD = 13.81). A survey on medical symptoms associated with COVID-19 and three instruments to evaluate: (1) depression, anxiety and stress, (2) impact of the event and (3) resilience were administered. Results: Younger people, with more symptoms associated with COVID-19 and those who reported higher scores of impact of event tended to present greater depressive, anxious and stress symptomatology. The impact of the event was the most determinant predictor. Resilience was protective against the impact of event, depression, anxiety and stress. Conclusions: The results show the differences in the psychological response to COVID-19 in each country and suggesting the need to develop public policies focused on prevention and promotion of integral health when facing sanitary emergencies.

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The population's behavioral responses to containment and precautionary measures during the COVID-19 pandemic have played a fundamental role in controlling the contagion. A comparative analysis of precautionary behaviors in the region was carried out. A total of 1184 people from Mexico, Colombia, Chile, Cuba, and Guatemala participated through an online survey containing a questionnaire on sociodemographic factors, precautionary behaviors, information about COVID-19, concerns, maintenance of confinement, and medical symptoms associated with COVID-19. Cubans reported the highest scores for information about COVID-19. Colombians reported less frequent usage of precautionary measures (e.g., use of masks), but greater adherence to confinement recommendations in general, in contrast to the low levels of these behaviors in Guatemalans. Chileans reported greater pandemic-related concerns and the highest number of medical symptoms associated with COVID-19. These findings allow a partial characterization of the Latin American population's responses during the second and third phases of the COVID-19 pandemic and highlight the importance of designing and managing public health policies according to the circumstances of each population when facing pandemics.

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OBJECTIVES: Interprofessional collaboration in the training of nursing and psychology students helps provide students of both disciplines with the ability and competences they need to best attend to their patients. This study implemented and analyzed a method for developing the competences of each discipline in a scenario of joint clinical simulation that incorporates mental and physical health simultaneously, and measured the caring ability of the participating students. METHODS: Participants took a self-applied survey measuring their own caring ability. After, a clinical simulation was performed where nursing students performed clinical interviews on psychology students, who acted as standardized patients. Caring abilities were measured in the nursing students, and the psychology students implemented an intervention service measuring caring ability and brief - debrief simulation by coaching to nursing students. RESULTS: The results indicated that the self-applied questionnaire of caring ability resulted in scores significantly higher than what was measured by observers. CONCLUSIONS: The results contribute to the development of protocols, training and collaborative work practices in interprofessional education, which allow the scaling of these competences.

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BACKGROUND: Sudomotor dysfunction may appear in early stages of diabetic neuropathy. AIM: To evaluate the diagnostic capacity of the Neuropad test, based on the detection of sudomotor dysfunction, as an early indicator of diabetic neuropathy. MATERIAL AND METHODS: In Forty-two type 2 diabetic patients, the Neuropad test was compared with the 10 g monofilament test (proposed in the technical orientation of diabetic foot of the Ministry of Health of Chile), deep and thermal sensitivity. RESULTS: The surface sensitivity assessed with a brush had a sensitivity and specificity of 18.8 and 100% respectively when compared with the 10 g monofilament. When compared with the Neuropad, the figures were 9 and 100%, respectively. Pain perception sensitivity and specificity were 13 and 100% respectively when compared with the 10 g monofilament. The figures were 6 and 100%, when compared with the Neuropad. Thermal discrimination had a sensitivity and specificity of 88 and 33% respectively when compared with the 10 g monofilament. The figures were 75 and 25% respectively when compared with the Neuropad. The deep sensitivity evaluated with a 128 Hz tuning fork had a sensitivity and specificity of 31 and 100% respectively when compared with the 10 g monofilament. The figures were 16 and 31% respectively when compared with the Neuropad. The Neuropad had a sensitivity and specificity of 94 and 29% respectively were compared with the 10 g monofilament. CONCLUSIONS: Neuropad had a good diagnostic yield for the early detection of sudomotor dysfunction.

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Background: Sudomotor dysfunction may appear in early stages of diabetic neuropathy. Aim: To evaluate the diagnostic capacity of the Neuropad test, based on the detection of sudomotor dysfunction, as an early indicator of diabetic neuropathy. Material and Methods: In Forty-two type 2 diabetic patients, the Neuropad test was compared with the 10 g monofilament test (proposed in the technical orientation of diabetic foot of the Ministry of Health of Chile), deep and thermal sensitivity. Results: The surface sensitivity assessed with a brush had a sensitivity and specificity of 18.8 and 100% respectively when compared with the 10 g monofilament. When compared with the Neuropad, the figures were 9 and 100%, respectively. Pain perception sensitivity and specificity were 13 and 100% respectively when compared with the 10 g monofilament. The figures were 6 and 100%, when compared with the Neuropad. Thermal discrimination had a sensitivity and specificity of 88 and 33% respectively when compared with the 10 g monofilament. The figures were 75 and 25% respectively when compared with the Neuropad. The deep sensitivity evaluated with a 128 Hz tuning fork had a sensitivity and specificity of 31 and 100% respectively when compared with the 10 g monofilament. The figures were 16 and 31% respectively when compared with the Neuropad. The Neuropad had a sensitivity and specificity of 94 and 29% respectively were compared with the 10 g monofilament. Conclusions: Neuropad had a good diagnostic yield for the early detection of sudomotor dysfunction.

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RESUMEN Validar instrumentos de medición de datos es fundamental para constituir conocimiento certero y objetivo respecto a los hábitos en ingesta alimentaria. El artículo pretende adaptar y validar para el contexto de educación superior un cuestionario que originalmente es de atención primaria, y que se transforme en un insumo válido para medir hábitos alimentarios en estudiantes universitarios. Basados en un cuestionario validado por Pino, Díaz y López en el 2011, se ajustaron las preguntas para un contexto de educación terciaria. El instrumento se aplicó a una muestra estratificada de 405 estudiantes de pregrado de una universidad perteneciente al Consejo de Rectores de Chile (CRUCH) de la región del Maule. Los datos fueron procesados mediante el paquete estadístico SPSS 20, y contó con los respectivos resguardos éticos mediante consentimiento informado firmado. Siguiendo los pertinentes análisis estadísticos para la validación del instrumento, podemos dar cuenta de un cuestionario confiable y aceptable (α= 0,815), estableciéndose 10 dimensiones con 35 preguntas. Se concluye un instrumento válido y adaptado para ser aplicado en estudiantes con el fin de identificar sus hábitos alimentarios en educación superior.

ABSTRACT Validating data measurement instruments is essential to establish accurate and objective knowledge regarding dietary habits. This article aims to adapt and validate a questionnaire to measure dietary habits originally designed for the primary care setting for use in the context of higher education. Based on a questionnaire validated by Pino, Díaz and López in 2011, the questions were adjusted for a tertiary education context. The instrument was applied to a sample of 405 undergraduate students of a university belonging to the Council of Rectors of Chile (CRUCH) of the Maule region, stratified by college year. Data were analysed using SPSS 20; signed informed consent was obtained. Following the relevant statistical analysis for the validation of an instrument, 10 dimensions with 35 questions were established. Results indicated that the instrument is trustworthy and acceptable (α= 0.815). We conclude that the instrument is a valid adaptation and can be applied to higher education students in order to identify their eating habits.

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Este estudo centra-se no uso de tarefas orais para desenvolver a vontade de comunicação dos alunos na Aprendizagem Baseada em Projetos. Os participantes foram 31 alunos da 10ª série de uma escola particular no Chile. Os dados desta pesquisa foram coletados através de aulas gravadas por áudio e uma escala de classificação de percepção. Os resultados mostram que, sempre que os alunos foram expostos a tarefas orais específicas, eles usaram o inglês com mais frequência para solicitar informações, em oposição ao L1, espanhol. Os alunos também se inclinam a dar mais informações em inglês ao responder a perguntas de sim/não, em oposição a perguntas de conteúdo de respostas completas. Além disso, os alunos usaram sua L1 poucas vezes; no entanto, o espanhol ainda era usado quando o professor não estava monitorando as tarefas. O estudo também revelou que os estudantes perceberam que usavam o inglês em diferentes frequências para diferentes funções do idioma.

Este estudio se centra en el uso de tareas orales para desarrollar las ganas de comunicación de los alumnos en el Aprendizaje Basada en Proyectos. Los participantes eran treinta y un alumnos de la 10º grado de una escuela particular en Chile. Se recolectaron los datos de esa investigación por intermedio de clases grabadas por audio y una escala de clasificación de percepción. Los resultados apuntan que, siempre que los alumnos fueron expuestos a tareas orales específicas, ellos usaron el inglés con más frecuencia para solicitar información, en oposición al L1, español. Los alumnos también se inclinan a dar más información en inglés al contestar preguntas del tipo sí/no, en oposición a preguntas de contenido de respuestas completas. Además, los alumnos usaron su L1 pocas veces; sin embargo, el español aún era usado cuando el profesor no estaba monitoreando las tareas. El estudio también apuntó a que los estudiantes percibieron que usaban el inglés en distintas frecuencias para diferentes funciones del idioma.

This study focuses on the use of oral tasks to develop students' willingness to communicate (WTC) under a Project Based Learning (PBL) approach. The participants were thirty-one 10th graders from a private school in Chile. The data of this research was collected through audio-recorded lessons and a students' perception rating scale. The findings show that whenever the students were exposed to specific oral tasks, they used English more frequently to ask for information, as opposed to their L1, Spanish. The students also inclined to give more information in English when answering yes/no questions, as opposed to wh- questions. Moreover, the students used their L1 very few times; however, Spanish was still used when the teacher was not monitoring the tasks. The study also revealed that the students perceived they used English in different frequencies for different language functions.

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