Flat-bands in translated and twisted bilayer Penrose quasicrystals.

Correlated phases in Moiré materials together with the flat-bands in twisted systems play a central role to explain superconductivity in the new twisted bilayer graphene. In this paper, flat-bands are shown to exist in both translated and twisted bilayer of quasicrystals. Such flat-bands arise for different displacements and twisting angles of two-coupled Penrose lattices where Moiré patterns are also shown. Moiré patterns analyzed in this work have at least two inverted worms showing an interference pattern going along the five-fold axes of the pentagon. In order to analyze the behavior of the flat band, our study has been done for fixed interference worm directions but increasing the worm interference density, and for fixed worm interference density but increasing the number of worm directions. In case of rotations, the Moiré patterns that occurs for special angles such asπ/5, 2π/5, 3π/5, 4π/5 andπare discussed in detail because they clearly show flat-bands along with quasicrystalline electronic states at the Fermi level.

Rendimiento académico de estudiantes universitarios en asignaturas de las ciencias morfológicas: uso de aprendizajes activos basados en problemas (ABP) / Academic performance in university students in morphological science courses: use of active problem-based learning (PBL)

RESUMEN: La educación universitaria busca desarrollar competencias profesionales y capacidades para el aprendizaje autónomo. Las metodologías de aprendizajes activos, centrado en los alumnos, como el aprendizaje basado en problemas (ABP), podría ser de gran utilidad en mejorar el rendimiento académico en asignaturas de las Ciencias Básicas en estudiantes de carreras de salud y medicina. El objetivo de este estudio fue determinar el impacto del uso de la metodología activa de aprendizaje basado en problemas, sobre el rendimiento académico de estudiantes universitarios que cursan asignaturas morfo-biológicas en las carreras de Kinesiología y de Obstetricia. De un universo de 500 alumnos que ingresaron a los primeros años de carreras de la salud de la Universidad de Tarapacá (año lectivo 2018), se seleccionaron 100 estudiantes (mayores de 18 años), separando como grupo control o no intervenido (n=50) a estudiantes de Obstetricia y grupo intervenido, con aplicación de ABP (n=50), estudiantes de la carrera de Kinesiología. El estudio tuvo una duración de 24 semanas lectivas. Los resultados muestran que el grupo intervenido mejoró significativamente el rendimiento académico, con un 98% de aprobación y una evaluación final de 5,9. El grupo control alcanzó un 84 % de aprobación y evaluación final de 4,8. Se concluye que el uso de metodología activa de ABP, mejora significativamente el rendimiento académico de los estudiantes de ciencias de la salud que cursan asignaturas morfo-biológicas y que las actividades con participación directa a través de cuestionarios y exposiciones científicas grupales e individuales permiten que el estudiante sea su propio agente de cambio en los procesos de evaluación formativa. Se sugiere implementar este tipo de metodologías activas en los cursos regulares considerando además, los factores psicológicos del aprendizaje.

SUMMARY: University education seeks to develop professional skills and capacities for autonomous learning. Active learning methodologies, centered on students, such as problem- based learning (PBL), could be very useful in improving academic performance in Basic Sciences courses in health and medical students. The objective of this study was to determine the impact of the use of the active problem-based learning methodology on the academic performance of university students who take morpho-biological courses in the Kinesiology and Obstetrics degree programs. From a total of 500 students who entered the first years of health degrees at the University of Tarapacá (academic year 2018), 100 students (over 18 years of age) were selected, separating as a control or non-intervened group (n = 50) to Obstetrics students and intervened group, with application of ABP (n = 50), students of the Kinesiology degree program. The study lasted 24 school weeks. The results show that the intervened group significantly improved academic performance, with 98 % approval and a final evaluation of 5.9. The control group achieved 84 % approval and a final evaluation of 4.8. It is concluded that the use of the active PBL methodology significantly improves the academic performance of health sciences students who take morpho-biological subjects and that activities with direct participation through questionnaires and group and individual scientific presentations, allow the student be their own agent of change in the educational assessment processes. It is suggested to implement this type of active methodologies in regular courses, also considering the psychological factors of learning.

Patrones morfológicos asociados a factores de riesgo metabólico en población de adolescentes escolarizados / Morphological patterns associated with metabolic risk factors in the adolescent school population

RESUMEN: El aumento sostenido en la prevalencia de sobrepeso y obesidad en niños, niñas y adolescentes, causa alarma en la comunidad científica, que observa incrementos importantes en las enfermerdades asociadas a Síndrome Metabólico (SM), en la vida adulta. Chile presenta un 75 % con sobrepeso y obesidad en la población adulta y un 50,9 % en la población estudiantil, con un 66,2 % de sedentarismo. Los objetivos de este trabajo fueron determinar los perfiles antropométricos y su asociación a riesgo metabólico en adolescentes de colegio particular subvencionado de Arica-Chile. El total de los alumnos de enseñanza media, n= 810 (mujeres n= 437 y hombres n= 373), fueron evaluados según: peso, talla, perímetro de cintura, índice cintura-talla (ICT), índice de masa corporal (IMC). A todos ellos se les calculó el riesgo metabólico según protocolos de Ashwell & Gibson (2016) y el IMC según fórmula de Quetelet. Los datos fueron analizados en estadístico para tendencia central, dispersión y porcentajes. Para correlación se utilizó test de Pearson (r>0,5). Los resultados muestran que un 44,1 % de las mujeres y un 37,2 % de los hombres presentan sobrepeso y obesidad. El riesgo metabólico general de la población en estudio fue de 24,6 % (24,7 % y 24,4 % en mujeres y hombres respectivamente). Se observó una alta correlación entre PC / ICT (r= 0,92), IMC / ICT (r= 0,86) y Peso / PC (r= 0,87). Se concluye que las y los adolescentes presentan valores antropométricos alterados que indican altos índices de riesgos metabólicos. Los parámetros más alterados se observan en el segundo año de enseñanza media con porcentajes de sobrepeso y obesidad de 49,1 % en las mujeres versus 33,8 % en los hombres. Independientemente, los hombres presentaron mejores índices morfométricos que las mujeres. Se observaron altas correlaciones (r> 0,5) en todos los parámetros en estudio, asociados a riesgo metabólico. Se sugiere enfocar las intervenciones educativas según sello de vida saludable, incentivando la actividad física y mejorar los hábitos alimenticios en las y los adolescentes escolarizados.

SUMMARY: The sustained increase in the prevalence of overweight and obesity in children and adolescents causes alarm in the scientific community, who observe significant increases in diseases associated with Metabolic Syndrome (MS), in adult life. Chile presents 75 % with overweight and obesity in the adult population and 50.9 % in the student population and with 66.2 % of sedentary lifestyle. The objectives of this work were to determine the anthropometric profiles and their association with metabolic risk in adolescents from a subsidized private school in Arica-Chile. The total of high school students, n = 810 (women n = 437 and men n = 373), were evaluated according to: weight, height, waist circumference, waist-height index (WHI), body mass index (BMI). Metabolic risk was calculated for all of them according to Ashwell & Gibson protocols and BMI according to Quetelet's formula. The data were analyzed in statistics for central tendency, dispersion, and percentages. Pearson test (r> 0.5) was used for correlation. The results show that 44.1 % of women and 37.2 % of men are overweight and obese. The general metabolic risk of the study population was 24.6 % (24.7 % and 24.4 % in women and men, respectively). A high correlation was observed between WC / WHI (r = 0.92), BMI / WHI (r = 0.86) and Weight / WC (r = 0.87). It is concluded that adolescents present altered anthropometric values that indicate high rates of metabolic risks. The most altered parameters were observed in the second year of secondary education with percentages of overweight and obesity of 49.1 % in women versus 33.8 % in men. Regardless, males presented better morphometric indices than females. High correlations (r> 0.5) were observed in all the parameters under study, associated with metabolic risk. It is suggested to focus educational interventions according to the seal of healthy living, encouraging physical activity and improving eating habits in school adolescents.

Composición corporal y factores de riesgo metabólico en profesores de enseñanza básica de colegios de Chile / Body composition and metabolic risk factors in primary in primary school teachers in Chile

En el mundo la obesidad es considerada una pandemia que provoca grandes cambios metabólicos, responsables de las llamadas enfermedades crónicas no transmisibles (ECNT), las cuales presentan un 60 % de mortalidad, según la Organización Mundial de la Salud (2016). En Chile el 75 % de la población adulta y el 50,9 % de la población estudiantil, muestran índices de masa corporal de sobrepeso y obesidad, con un nivel de sedentarismo general de 66,2 %. Los objetivos de este trabajo fueron determinar los perfiles antropométricos, riesgo metabólico y niveles de actividad física en profesores de enseñanza básica en un colegio particular subvencionado de Arica-Chile. El total de los profesores, 12 varones y 29 mujeres, fueron evaluados según: peso, talla, perímetro de cintura, índice cintura-talla (ICT), índice de masa corporal (IMC), masa grasa (MG), masa grasa visceral (MGV) y masa muscular (MM). A todos ellos se les calculó el riesgo metabólico según protocolos de Ashwell & Gibson (2016) y el IMC según fórmula de Quetelet. Para determinar los porcentajes de MG, MM y MGV, se utilizó instrumento de bioimpedancia eléctrica, Omron HBF-514C. Posteriormente se les aplicó una encuesta sobre nivel de actividad física (IPAQ). Los datos fueron analizados en estadístico IBM SPSS para tendencia central, dispersión, conteos y porcentajes. Para correlación se usó test de Pearson (r>0,5). Los resultados muestran que un 68,3 % de los profesores presenta sobrepeso y obesidad. El IMC y porcentaje de MGV son significativamente más alto en varones que en mujeres (30,6 ±7,0 / 26,9±4,6 y 11,2±5,6 / 7,6±2,5 respectivamente). El riesgo metabólico general de la población en estudio fue de 58,5 % (75 % y 51,7 % varones y mujeres respectivamente). Se observa una alta correlación entre IMC-MGV (0,84), IMC-ICT (0,84) y MM-MG (0,85). Respecto al nivel de actividad física, solo el 19,5 % de los profesores muestra un nivel de actividad física alto. Se concluye que los profesores presentan valores antropométricos alterados que indican altos índices de riesgos metabólicos y con bajos niveles de actividad física. Independientemente, las mujeres presentan mejores índices morfométricos en todos los parámetros en estudio respecto a los profesores varones. Existe una alta correlación (r) entre el índice de masa corporal y los porcentajes de masa de grasa visceral y el índice de de cintura talla. Se sugiere enfocar las intervenciones educativas según sello de vida saludable, incentivando la actividad física y mejorar los hábitos alimenticios en los profesores.

Obesity is considered a global pandemic that causes major metabolic changes. It is responsible for the so-called noncommunicable chronic diseases (NCDs), which report a 60 % mortality rate (WHO, 2017). In Chile, 63 % of the population shows body mass indexes (BMI) of overweight and obesity, with a sedentary level of 86.7 %. The objectives of this work were to determine the anthropometric profiles, metabolic risk, and physical activity levels in primary school teachers, in a subsidized school in Arica, Chile. The teachers (n=41), 12 men, and 29 women were evaluated according to weight, height, waist circumference (WC), waist-to-height index (WHI), BMI, Fat Mass (FM), Visceral Fat Mass (VFM) and Muscle Mass (MM). All of them were calculated for metabolic risk, according to Ashwell & Gibson protocols and BMI according to Quetelet's formula. To determine the percentages of FM, MM, and VFM, an electric bioimpedance instrument, Omron HBF-514C, was used. Subsequently, a survey of physical activity level (IPAQ) was applied. The data were analyzed in the IBM SPSS statistic for central tendency, dispersion, counts, and percentages. For correlation, Pearson's test (r> 0.5) was used. The results show that 68.3 % of teachers are overweight and obese. BMI and percentage of VFM are significantly higher in men than in women (30.6 ± 7.0 / 26.9 ± 4.6 and 11.2 ± 5.6 / 7.6 ± 2.5 respectively). The overall metabolic risk of the study population was 58.5 % (75 % and 51.7 % men and women, respectively). There is a high correlation between BMIVFM (0.84), BMI-WHI (0.84), MM-FM (0.85). Regarding the level of physical activity, only 19.5 % of teachers show a high level of physical activity. It is concluded that teachers have altered anthropometric values that indicate high rates of metabolic risks and low levels of physical activity. Regardless, women have better morphometric indexes in all parameters under study, compared to male teachers. There is a high correlation (r) between body mass index and percentages of visceral fat mass and waist height index. It is suggested to focus on educational interventions according to the healthy life seal, promoting physical activity, and improving eating habits in teachers.

Anthropometric characteristics, body composition and somatotype of elite Pan-American race walking 20k / Características antropométricas, composición corporal y somatotipo de marchistas panamericanos de élite 20k

The anthropometric and somatotype evaluation is an essential tool in the selection and control of high-performance athletes. The aim of this study was to describe the somatotype and body composition of male elite race walkers (20 k modality), and its relationship with athletic performance. Twenty-four race walkers participated in this study. The sample was divided into two groups: the race walkers with the best performance (upper 25 percentile; n=7) and the second group (n=17) that corresponds to the rest of the participants. Weight (kg), height (cm), seven skinfolds, two diameters and five perimeters were measured. Body fat percentage (BF%) were estimated with the Yuhasz formula, and the somatotype was used applying the Heath-Carter method. The best performing athletes were taller (178.3 ± 4.4 cm vs. 173.7 ± 5.6 cm, p <0.05) and showed a greater ectomorphic component (p<0.05) than the rest of the participants. The somatotype of the best performance athletes was 2.2-2.8-4.1 against the 2.5-3.8-2.9 of the lowest performing athletes. The average time (hours, minute, seconds) of execution of the race in athletes of better performances was 1:22:40, in comparison with the athletes of lower performances with 1:32:41 (p<0.02). The ectomorphic component and height are morphological characteristics that can determine athletic performance of race walkers. It is suggested to consider these factors in the selection of the race walkers.

La evaluación antropométrica y del somatotipo es una importante herramienta en la selección y control de los atletas de alto rendimiento. El objetivo de este estudio fue describir el somatotipo y composición corporal de hombres marchistas olímpicos, modalidad 20 k, y su relación con el rendimiento atlético. Veinticuatro atletas de marcha participaron en este estudio. La muestra fue dividida en dos grupos: los marchistas de mejores rendimientos p25 superior (n=7) y el segundo grupo (n=17) que corresponde al resto de los participantes. Se registró el peso (kg), talla (cm), siete pliegues cutáneos, dos diámetros y cinco perímetros. Se estimó el porcentaje de grasa corporal (%GC) con la fórmula de Yuhasz y se describió el somatotipo utilizando el método de Heath-Carter. Se reporta una mayor altura en los atletas de mejor rendimiento (178,3±4,4 cm vs. 173,7±5,6 cm; p<0,05) y mayor componente ectomorfico (p<0,05) que el resto de los participantes. El somatotipo de los atletas de mejor rendimiento fue de 2.2-2.8-4.1 frente al 2.5-3.8-2.9 de los atletas de menor rendimiento. El tiempo promedio (hora, minuto, segundo) de ejecución de la carrera en atletas de mejores rendimientos fue de 1:22:40, en comparación con los atletas de menores rendimientos con 1:32:41 (p <0,02). El componente ectomórfico y altura serian características morfológicas que pueden determinar el rendimiento deportivo de atletas de marcha. Se sugiere considerar estos factores en la selección de los marchistas olímpicos.

Effect of the addition of thiourethane oligomers on the solâ¿¿gel composition of BisGMA/TEGDMA polymer networks.

OBJECTIVES: Thiourethane oligomers have been shown to increase the fracture toughness and reduce the polymerization stress of methacrylate-based materials. However, network formation has not been elucidated in these materials yet. The aim of this study was to evaluate how the addition of a thiourethane oligomer (TU) influences the sol/gel composition and network structure of methacrylate-based materials using dynamic mechanical analysis and extraction methods. MATERIALS AND METHODS: BisGMA/TEGDMA at systematically varied mass ratios (20/80 to 80/20wt%) were mixed with pre-polymerized thiourethane oligomers at 0 (control) or 20wt%, synthesized by combining pentaerythritol tetra-3-mercaptopropionate with dicyclohexylmethane 4,4⿲-Diisocyanate, at 1:2 isocyanate:thiol. 0.1wt% of 2,2-Dimethoxy-2-phenylacetophenone was added as the photoinitiator and 0.3wt% of 2,6-di-tert-butyl-4-methylphenol was added as a free radical inhibitor. Disk specimens (0.8ÿ10mm in diameter, n=3) were photoactivated at 270mW/ (320â¿¿500nm) for 1min. The degree of conversion (DC) was measured in near-IR (Ë¿6165cmâ¿¿1). Specimens were immersed in two different solvents (water for 7 days or dicholoromethane for 48h). Water sorption (WS) and solubility (SL) were obtained according to ISO 4049. The leachates for both solutions were analyzed with 1H-NMR (400MHz, CDCL3). Bar specimens (1ÿ3ÿ25mm, photocured and then post-processed at 180°C for 8h to DC>95%) were subjected to dynamic mechanical analysis (â¿¿30 to 230°C) to obtain glass transition temperature (Tg), tan delta curves and crosslinking density (ν). Data was analyzed with two-way ANOVA/Tukeyâ¿¿s test (95%). RESULTS: In general, the presence of TU increased the overall conversion. The WS was similar for all groups, but the SL decreased by 2-fold with the addition of the TU oligomer for all compositions, except BisGMA/TEGDMA 80/20. The BisGMA concentration of the leachates increased with increasing BisGMA in the initial mixture, and with the presence of thiourethane. This compositional drift of the gel with the presence of TU was attributed to the preferential dissolution of TEGDMA into the TU network. Tg and ν decreased with the addition of TU, as expected. The addition of TU produced more homogeneous networks, as evidenced by narrower breadth of the tan delta curve. CONCLUSION: The addition of TU affected the composition of the sol/gel in crosslinked networks, which were more homogeneous and presented 2-fold less potentially toxic leachates than the methacrylate controls. CLINICAL SIGNIFICANCE: The addition of TU may produce less cytotoxic materials based on the increased conversion and reduced amount of unreacted extractables from its network after water storage.

Extended Blind End-member and Abundance Extraction for Biomedical Imaging Applications.

In some applications of biomedical imaging, a linear mixture model can represent the constitutive elements (end-members) and their contributions (abundances) per pixel of the image. In this work, the extended blind end-member and abundance extraction (EBEAE) methodology is mathematically formulated to address the blind linear unmixing (BLU) problem subject to positivity constraints in optical measurements. The EBEAE algorithm is based on a constrained quadratic optimization and an alternated least-squares strategy to jointly estimate end-members and their abundances. In our proposal, a local approach is used to estimate the abundances of each end-member by maximizing their entropy, and a global technique is adopted to iteratively identify the end-members by reducing the similarity among them. All the cost functions are normalized, and four initialization approaches are suggested for the end-members matrix. Synthetic datasets are used first for the EBEAE validation at different noise types and levels, and its performance is compared to state-of-the-art algorithms in BLU. In a second stage, three experimental biomedical imaging applications are addressed with EBEAE: m-FLIM for chemometric analysis in oral cavity samples, OCT for macrophages identification in post-mortem artery samples, and hyper-spectral images for in-vivo brain tissue classification and tumor identification. In our evaluations, EBEAE was able to provide a quantitative analysis of the samples with none or minimal a priori information.

Multiscale seascape habitat of necto-benthic littoral species, application to the study of the dusky grouper habitat shift throughout ontogeny.

Describing the spatial patterns of benthic coastal habitats and investigating how those patterns affect the ecology of inhabiting species is a main objective of seascape ecology. Within this emerging discipline spatial scale is a principal topic. Different spatial scales inform on different characteristics of the habitat and therefore the relation between species and their habitats would be better defined when observed at multiple levels of spatial scale. Here we apply a multiscale seascape approach to investigate the habitat preferences of juvenile and adult individuals of dusky grouper (Epinephelus marginatus) in a Mediterranean marine protected area. Results show that the information obtained at different spatial scales is complementary, improving our capability to identify the preferred habitats and how it changes throughout ontogeny. These results show the relevance of implementing multiscale seascape ecology approaches to investigate the species-habitat relationships and to improve management and conservation of necto-benthic endangered top predators.

Quadratic blind linear unmixing: A graphical user interface for tissue characterization.

Spectral unmixing is the process of breaking down data from a sample into its basic components and their abundances. Previous work has been focused on blind unmixing of multi-spectral fluorescence lifetime imaging microscopy (m-FLIM) datasets under a linear mixture model and quadratic approximations. This method provides a fast linear decomposition and can work without a limitation in the maximum number of components or end-members. Hence this work presents an interactive software which implements our blind end-member and abundance extraction (BEAE) and quadratic blind linear unmixing (QBLU) algorithms in Matlab. The options and capabilities of our proposed software are described in detail. When the number of components is known, our software can estimate the constitutive end-members and their abundances. When no prior knowledge is available, the software can provide a completely blind solution to estimate the number of components, the end-members and their abundances. The characterization of three case studies validates the performance of the new software: ex-vivo human coronary arteries, human breast cancer cell samples, and in-vivo hamster oral mucosa. The software is freely available in a hosted webpage by one of the developing institutions, and allows the user a quick, easy-to-use and efficient tool for multi/hyper-spectral data decomposition.

Deconvolution of fluorescence lifetime imaging microscopy by a library of exponentials.

Fluorescence lifetime microscopy imaging (FLIM) is an optic technique that allows a quantitative characterization of the fluorescent components of a sample. However, for an accurate interpretation of FLIM, an initial processing step is required to deconvolve the instrument response of the system from the measured fluorescence decays. In this paper, we present a novel strategy for the deconvolution of FLIM data based on a library of exponentials. Our approach searches for the scaling coefficients of the library by non-negative least squares approximations plus Thikonov/l(2) or l(1) regularization terms. The parameters of the library are given by the lower and upper bounds in the characteristic lifetimes of the exponential functions and the size of the library, where we observe that this last variable is not a limiting factor in the resulting fitting accuracy. We compare our proposal to nonlinear least squares and global non-linear least squares estimations with a multi-exponential model, and also to constrained Laguerre-base expansions, where we visualize an advantage of our proposal based on Thikonov/l(2) regularization in terms of estimation accuracy, computational time, and tuning strategy. Our validation strategy considers synthetic datasets subject to both shot and Gaussian noise and samples with different lifetime maps, and experimental FLIM data of ex-vivo atherosclerotic plaques and human breast cancer cells.

Extended output phasor representation of multi-spectral fluorescence lifetime imaging microscopy.

In this paper, we investigate novel low-dimensional and model-free representations for multi-spectral fluorescence lifetime imaging microscopy (m-FLIM) data. We depart from the classical definition of the phasor in the complex plane to propose the extended output phasor (EOP) and extended phasor (EP) for multi-spectral information. The frequency domain properties of the EOP and EP are analytically studied based on a multiexponential model for the impulse response of the imaged tissue. For practical implementations, the EOP is more appealing since there is no need to perform deconvolution of the instrument response from the measured m-FLIM data, as in the case of EP. Our synthetic and experimental evaluations with m-FLIM datasets of human coronary atherosclerotic plaques show that low frequency indexes have to be employed for a distinctive representation of the EOP and EP, and to reduce noise distortion. The tissue classification of the m-FLIM datasets by EOP and EP also improves with low frequency indexes, and does not present significant differences by using either phasor.

Composición corporal y el efecto de un programa de fuerza auxiliar para prevenir lesiones en musculos cuádriceps femoral, isquiotibiales y bíceps femoral en jóvenes universitarios futbolistas / Body composition and the effect of an auxiliary force program to prevent injuries in femoral quadriceps, hamstrings and biceps femoris muscles in young college players

El objetivo de esta investigación fue conocer los efectos de un programa de fuerza auxiliar en la prevención de lesiones de los músculos: cuádriceps femoral, isquiotibiales y bíceps femoral en futbolistas universitarios de la ciudad de Madrid, independiente del programa normal de entrenamiento del club universitario. Veinticuatro jugadores universitarios de entre 19 a 28 años participaron en el estudio, separados en grupo control (n=12) y grupo experimental (n=12). En ambos grupos se evaluó inicialmente el desplazamiento y la velocidad (potencia), mediante un transductor de movimiento o "encoder". Posteriormente al grupo experimental se le aplicó un programa de fuerza auxiliar, para reforzar los músculos del muslo, por un período de 6 meses. El Comité de Ética/Bioética de la Universidad de Tarapacá, aprobó los protocolos de esta investigación. Los resultados muestran que el grupo experimental presenta un aumento significativo en la ganancia de fuerza/potencia, en relación al grupo control, expresada en watts (1187,6±110,4 vs. 1011,6±110,4, respectivamente). El porcentaje de recuperación de la fuerza fue significativamente mayor en el grupo experimental, con un 16,8% y 0,17% en el grupo de control. El porcentaje de jugadores lesionados en el grupo experimental fue significativamente menor que en el grupo control (16,6% y 50%, respectivamente). Se concluye que los programas preventivos de fuerza auxiliar, en los jugadores de futbol de entre 19 a 28 años, son eficaces en la prevención de lesiones musculares por la ganancia considerable de fuerza/potencia, aportando un importante beneficio económico y deportivo. Por lo tanto, se recomienda incluir estos programas de fuerza auxiliar en todos los clubes deportivos profesionales.

The objective of this research was to determine the effects of a program of auxiliary force in the prevention of injuries to muscles: quadriceps femoris, hamstrings and biceps femoris in college football players of the city of Madrid, independent of the normal training program of university club. Twenty-four college players aged 19­28 years participated in the study, divided into experimental group (n=12) and control group (n= 12). In both groups, the displacement and the velocity (potency) were initially assessed through a motion transducer or "encoder". Then in experimental group was implemented a program of auxiliary force for 6 months. The Ethics/Bioethics Committee at the Universidad of Tarapacá, approved the protocols of this research. The results shown in the experimental group, with program of auxiliary forces a significant increase in gain strength/potency, relative to the control group, expressed in watts (1187.6±110.4 vs. 1011.6±110.4 respectively), the percentage recovery of force was 16.8% in the experimental group and 0.1larger than bifurcation aneurysms until they 7% in the control group. The percentage of injured players in the experimental group was significantly lower than the control group (16.6% and 50% respectively). We conclude that preventive programs auxiliary force in football players 19 and 28 years are effective in preventing muscle injuries by the considerable gain strength/potency, providing great economic and sporting benefits. Therefore it is recommended include these programs of auxiliary force in all sports clubs.

[Survival of patients with metastatic breast cancer according to pathological types of tumors]. / Cáncer de mama metastásico: Caracterización de una cohorte según subtipos.

BACKGROUND: The prognosis of breast cancer (BC) is in part determined by the stage at diagnosis and its pathological characteristics. AIM: To evaluate the association between survival of women with metastatic breast cancer and pathological features of the tumor. PATIENTS AND METHODS: We obtained clinical and pathological data from patients diagnosed with a metastatic BC between 1999 and 2013. The expression of estrogen (ER) and progesterone (PR) receptors and human epidermal growth factor receptor 2 (HER2) was determined by immunohistochemistry. Clinicopathological subtypes were defined as: Luminal A: ER or PR positive, HER2 negative, histological grade (HG) 1 or 2; Luminal B: ER or PR positive, HER2 negative or positive or HG 3; triple negative (TN): ER, PR and HER2 negative, independent of the HG, positive HER2: ER, PR negative and HER2 positive, independent of HG. We analyzed survival based on these subtypes. RESULTS: We identified 54 patients aged 24 to 85 years, with metastatic BC at diagnosis. Seventy five percent had luminal tumors; 19.6% HER2 positive and 7.8% were TN. In 61% of evaluable tumors, HG was classified as 3. The frequency of HER2 positive and high HG tumors was greater in these patients with metastatic BC than in a non-metastatic local BC cohort. Survival was higher among patients with Luminal tumors than in women with non-Luminal cancer (56.4 and 11.4 months, respectively, p = 0.04). CONCLUSIONS: Patients with metastatic BC at diagnosis often had HER2 positive tumors and high HG. As in other studies, ER positive tumors had a better survival.

Effects of high altitude on morphophysiological patterns, perception and attention capacity in students from Putre (3500 m. a. s. l. ) and Arica (2 m. a. s. l. ), Chile / Efectos de la altura sobre patrones morfofisiológicos y en la capacidad atencional y de percepción en estudiantes de las comunas de Putre (3500 msnm) y de Arica (2 msnm), Chile

High altitude hypoxia is a stress that triggers several adaptive mechanisms, one of which is how the brain responds to lack of oxygen. The aim of this study was to determine changes in morphological and physiological patterns and in the attention capacity and perception in student populations from the highlands and from a sea level location. Eighty students, aged 14 to 16 years old, both sexes, from the Municipalities of Putre (3500 m.a.s.l.) and Arica (2 m.a.s.l.) participated in this study, with each group composed of 20 women and 20 men. After informed consent was obtained and with the students acceptance, parameters such as weight, height, BMI, heart rate, systolic and diastolic blood pressures were obtained. Subsequently, a psychometric test of attention and perception was applied. The results determined that the population from Putre had less weight and height than students from Arica. Males exhibited a significant decrease in heart rate and women had lower systolic and diastolic blood pressures than in the assessed sea level population. The levels of response in the psycho-technical tests were significantly lower in the population from high altitude, both in males and females. We conclude that high altitude causes changes in morphological and physiological patterns and in responsiveness in psycho-technical tests. However, further studies in psycho-perception are required to delineate the effects that are unique of ethnicity, culture and worldview of the people living in high altitude and their levels of response.

La hipoxia de altura es un estrés que dispara varios mecanismos adaptativos, uno de ellos es como el cerebro responde frente a la falta de oxígeno. El objetivo de este trabajo fue determinar cambios en los patrones morfológicos, fisiológicos y en la capacidad de atención y precepción de población estudiantil que vive en altura y a nivel del mar. Ochenta estudiantes de entre 14 a 16 años de ambos sexos, pertenecientes a las Comunas de Putre (3500 msnm) y Arica (2 msnm) participaron de este estudio. Cada grupo con 20 mujeres y 20 hombres fue medido para determinar su peso, talla, IMC, frecuencia cardiaca, presión sistólica y diastólica. Posteriormente se les aplicó una prueba psicométrica de atención y percepción. Los resultados determinan que la población de Putre presenta menor peso y talla que los alumnos de Arica. Los hombres muestran una disminución significativa de la frecuencia cardiaca y las mujeres presentan una presión sistólica y diastólica menor que lo observado en la población a nivel del mar. Los niveles de respuesta en la prueba psicotécnica son significativamente más bajos en la población que vive en altura tanto en hombres como mujeres. Se concluye que la altura provoca cambios en los patrones morfológicos, fisiológicos y en la capacidad de respuesta en el test psicotécnico. Sin embargo se requieren de mayores estudios de psicopercepción que permitan delimitar los efectos que son propios de la etnia, cultura y la cosmovisión de los pueblos que viven en altura y los niveles de respuesta de esta población.

Características clínico-patológicas y sobrevida de pacientes con cáncer de mama bilateral sincrónico / Clinicopathological features and survival of patients with bilateral synchronous breast cancer

Introduction: Bilateral synchronous breast cancer (BSBC) has a variable incidence and conflicting data on prognosis. Our goal is to evaluate the characteristics and survival of patients with BSBC treated at Cancer Center of the Pontificia Universidad Católica de Chile. Patients and Methods: Descriptive study. We identified patients treated between January 1999 and May 2013. We evaluated and compared characteristics from BSBC patients with a local cohort of non-synchronous breast cancer. Results: The incidence of BSBC was 1.8 percent (n = 28). Three patients were excluded because of missing data. Therefore we analyzed 25 patients (50 tumors). Median age: 50 years (33-84). The dominant tumor's diagnosis was clinical in 47.6 percent of cases, and imaging in 90.5 percent of the contra-lateral non-dominant (p = 0.04). Average tumor size of invasive tumors was 2.5 cm for dominant tumor versus 1.7 cm for the non-dominant (p = 0.02). 81.4 percent of invasive tumors were estrogen receptor (ER) positive. Histological and subtype concordance between both tumors was 88 percent and 72 percent respectively. 54 percent of patients with BSBC were managed with total mastectomy versus 28.4 percent in the control group no BSBC (p = 0.0001). The estimated overall survival at 10 years was 76.5 percent in patients with no BSBC versus 62 percent in those with BSBC (p = 0.08). Conclusions: The BSBC is rare. Frequently they are ER positive tumors, mostly diagnosed through images and managed with less conservative surgery.

Introducción: La incidencia y pronóstico del Cáncer de mama (CM) bilateral sincrónico (CMBS), no son bien conocidos. Evaluamos las características y sobrevida de pacientes con CMBS tratadas en el Centro de Cáncer de la Pontificia Universidad Católica de Chile. Pacientes y Método: Estudio descriptivo. Identificamos pacientes con CMBS tratadas entre enero de 1999 y mayo de 2013. Evaluamos sus características y las comparamos con una cohorte local de CM no sincrónico. Resultados: La incidencia de CMBS fue de 1,8 por ciento (n = 28). Se excluyeron 3 pacientes por falta de datos. Analizamos por tanto, 25 pacientes (50 tumores). Mediana de edad: 50 años (33-84). El diagnóstico del tumor dominante fue clínico en el 47,6 por ciento de los casos, y por imágenes en 90,5 por ciento de los contra-laterales no dominantes (p = 0,04). Tamaño tumoral promedio de los tumores invasores fue de 2,5 cm en tumores dominantes vs 1,7 cm en los no dominantes (p = 0,02). Un 81,4 por ciento de los tumores invasores fueron receptor de estrógenos (RE) positivos. La concordancia histológica y de subtipo histológico entre ambos tumores fue de 88 por ciento y 72 por ciento respectivamente. Un 54 por ciento de las pacientes con CMBS fueron manejadas con mastectomía total versus un 28,4 por ciento en el grupo control de CM no BS (p = 0,0001). La sobrevida global estimada a 10 años fue de un 76,5 por ciento en pacientes con CM no BS versus 62 por ciento en aquellos con CMBS (p = 0,08). Conclusiones: El CMBS es poco frecuente. Usualmente son tumores RE positivos que reciben con menos frecuencia manejo conservador de la mama.

Cáncer de mama metastásico: Caracterización de una cohorte según subtipos / Survival of patients with metastatic breast cancer according to pathological types of tumors

Background: The prognosis of breast cancer (BC) is in part determined by the stage at diagnosis and its pathological characteristics. Aim: To evaluate the association between survival of women with metastatic breast cancer and pathological features of the tumor. Patients and Methods: We obtained clinical and pathological data from patients diagnosed with a metastatic BC between 1999 and 2013. The expression of estrogen (ER) and progesterone (PR) receptors and human epidermal growth factor receptor 2 (HER2) was determined by immunohistochemistry. Clinicopathological subtypes were defined as: Luminal A: ER or PR positive, HER2 negative, histological grade (HG) 1 or 2; Luminal B: ER or PR positive, HER2 negative or positive or HG 3; triple negative (TN): ER, PR and HER2 negative, independent of the HG, positive HER2: ER, PR negative and HER2 positive, independent of HG. We analyzed survival based on these subtypes. Results: We identified 54 patients aged 24 to 85 years, with metastatic BC at diagnosis. Seventy five percent had luminal tumors; 19.6% HER2 positive and 7.8% were TN. In 61% of evaluable tumors, HG was classified as 3. The frequency of HER2 positive and high HG tumors was greater in these patients with metastatic BC than in a non-metastatic local BC cohort. Survival was higher among patients with Luminal tumors than in women with non-Luminal cancer (56.4 and 11.4 months, respectively, p = 0.04). Conclusions: Patients with metastatic BC at diagnosis often had HER2 positive tumors and high HG. As in other studies, ER positive tumors had a better survival.

Effects of malathion on cellularity and sperm differentiation in testis and epididymis of adult rats / Efectos del malatión en la celularidad y diferenciación de espermatozoides en testículo y epidídimo de ratas adultas

Malathion is an organophosphorous insecticide, used worldwide for pest and disease control; however, it could also affect the reproductive patterns of several species. The aim of this study was to determine the effects of malathion in the cellularity and sperm differentiation in testis and epididymis of rats. Twenty adult male Sprague Dawley rats were divided into a malathion-treated group (n=10, dose of 170 mg/kg via subcutaneous injection for a period of 13 days) and control group (n=10, injected only with normal saline). After treatments, the rats were sacrificed by regulated euthanasia and assessed for sperm count in testis and epididymis and epididymal teratospermia degree. The results showed a significant decrease in body, testicular and epididymal weight in animals treated with malathion. Testicular sperm counts in treated rats exhibited a significant decrease in the number of sperm compared to controls (42.56x106 vs. 95.99x106), as well as in epididymis (77.55x106 vs. 106.54x106). Concerning the degree of teratospermia, a significant increase of abnormal sperm in the epididymis of treated rats versus controls (42.1% vs. 21%, respectively) was observed. We conclude that malathion has a cytotoxic effect in rats, significantly reducing the number of sperm produced by the seminiferous tubules and affecting their quality and number during the process of maturation and capacitation in their transit through the epididymis, thus increasing the level of teratospermia.

El malatión es un insecticida organofosforado, ampliamente usado en el control de plagas y pestes, sin embargo también puede afectar a los patrones reproductivos de las especies. El objetivo de este trabajo fue determinar los efectos de malatión en la celularidad y diferenciación de espermatozoides en testículo y en epidídimo de ratas. Veinte ratas macho adultas de la cepa Sprague Dawley, fueron divididos en grupo tratado con malatión (n=10) en dosis de 170 mg/kg de peso, inyección sub cutánea (s.c.), por un período de 13 días (duración del ciclo del epitelio seminífero) y grupo control (n=10), los cuales solo fueron inyectados con suero fisiológico. Finalizado el tratamiento las ratas fueron sacrificadas por eutanasia normada y se procedió a medir el recuento espermático en testículo y epidídimo y el grado de teratospermia en epidídimo. Los resultados obtenidos muestran una disminución significativa en el peso corporal, testicular y del epidídimo de ratas machos tratados con malatión. El recuento espermático en testículo de ratas tratadas, al compararlos con ratas controles, muestra una disminución significativa en el número de espermatozoides (42,56x106 / 95,99x106), igual comportamiento se observó en epidídimo (77,55 x106 / 106,54 x106). Al determinar el grado de teratospermia se observó un aumento significativo de espermatozoides anormales, en el epidídimo de las ratas tratadas versus los controles (42,1% y 21%, respectivamente). Se concluye que malatión tiene un efecto citotóxico en ratas, disminuyendo significativamente el número de espermatozoides producidos por los túbulos seminíferos y afectando la calidad y el número de ellos durante el proceso de maduración y capacitación, en su tránsito por el epidídimo, aumentando el nivel de teratospermia.

Determinación del Porcentaje de Masa Grasa, según Mediciones de Perímetros Corporales, Peso y Talla: Un Estudio de Validación / Determination of Fat Mass Percentage by Measuring Body Circumferences, Weight and Height: A Validation Study

La obesidad se caracteriza por un aumento excesivo de la grasa corporal. En Chile, en el año 2010, se determinó que el 25,1% de la población sobre los 15 años, presentaba obesidad y un 39,3 % sobrepeso. El objetivo de esta investigación fue validar un método económico y de fácil manejo para los profesionales de la Educación, que permita determinar los porcentajes de masa grasa (%MG) en población escolar, ocupando las variables de perímetros corporales, el peso y la talla (PPT). A una muestra de 1725 alumnos de enseñanza básica, 1020 niñas y 705 niños, de entre 10 a 14 años de edad de la Comuna de Arica (XV Región), se les determinó el %MG según el modelo propuesto de perímetro, peso y talla (PPT). Como modelos de referencia se utilizaron los protocolos de Durnin & Womersley (1974) y el protocolo de Slaughter et al. (1988). Los resultados muestran que los índices de masa corporal (IMC), presentan valores normales de 21 kg/m2 tanto para niñas como niños. La sumatoria de los pliegues corporales de bíceps, tríceps, subescapular, ilíaco y abdominal (S5), es significativamente mayor en la población femenina, respecto a los varones (108,5 mm y 81,4 mm respectivamente). La comparación del porcentaje de masa grasa, entre los diversos modelos en estudio demuestra que el modelo propuesto de PPT, no presenta diferencias significativas (NS). Todos ellos expresan valores sobre el 20% en la población en estudio, propio de sobrepeso y obesidad. Se concluye que el modelo de perímetros, peso y talla, es eficaz para determinar los porcentajes de masa grasa en población escolar. La población en estudio presenta altos índices de masa grasa.

Obesity is characterized by an excessive increase in body fat. In Chile (2010), 25.1% and 39,3% of the population over 15 years old were reported with obesity and overweight respectively. The objective of this study was to validate an economic and easy method to use for education professionals to determine the percentage of fat mass (% FM) in schoolchildren, measuring the variables body circumferences, weight and height (CWH).A sample of 1725 primary school students, 1020 girls and 705 boys, in age of 10 to 14 years old from Arica (Region XV), were analyzed to determine % FM according to the model proposed (CWH), as reference models were used Durnin & Womersley protocols (1974) and the Slaughter et al. protocol (1988).The results show that body mass index (BMI), have normal values of 21 kg/m2 for both girls and boys. The sum of the body skinfolds biceps, triceps, subscapular, iliac and abdominal (S5) is significantly higher in women, compared to males (108.5 mm and 81.4 mm respectively).The comparison of the percentage of fat mass between the various models in study demonstrates that the proposed model of "circumferences, weight and height (CWH), not show significant differences (NS). All models express percentage of fat mass over 20% in the study population, typical of overweight and obesity. We conclude that the model of circumference, weight and height (CWH), is effective to determine the percentages of body fat in school population. In addition the study population has high levels of fat mass.

Búsqueda e inclusión laboral de personas con discapacidad cognitiva en Chile: una mirada desde sus madres / Job search and inclusion of people with cognitive disability in Chile: a look from their mothers

El presente artículo identifica los factores sociales que inciden en el proceso de búsqueda e inclusión laboral de jóvenes que presentan una discapacidad cognitiva en Chile, intentando dilucidar qué aspectos se constituyen en barreras para la incorporación a un trabajo desde la perspectiva de sus madres. Se basa en una investigación cualitativa en la que se utilizaron entrevistas en profundidad y cuestionarios semi estructurados, para identificar las visiones y significaciones de las madres de jóvenes con discapacidad cognitiva en torno al proceso de búsqueda e incorporación laboral. Como principales resultados, se han identificado tres tipos de obstáculos al empleo de los jóvenes con discapacidad cognitiva en el discurso de las entrevistadas: obstáculos sociales, personales y doméstico familiares. En el plano social, las participantes señalan la falta de interés por parte de empresas privadas, la prevalencia de estereotipos y la creencia común que las personas con discapacidad son menos productivas. En el plano interno/nivel de familia, los padres se reconocen temerosos ante el proceso de integración, lo que asocian a que las personas con discapacidad cognitiva son más vulnerables y se encuentran expuestas a sufrir abusos o perjuicios, por lo que toman una postura selectiva ante las posibles ofertas de empleo. En lo que respecta al nivel personal, encontramos las declaraciones asociadas a una baja autoestima, inseguridad, falta de autonomía comunicativa y problemas de salud de las personas con discapacidad cognitiva, que influyen en la capacidad de búsqueda y en la adecuación personal al puesto de trabajo.

The aim of this paper is to stress out the the social factors that Chilean young people with cognitive disability have to face in the process being inserted in a job. It intents to figure out, from the mothers’ point of view, the aspects that constitutes a barrier for their children to be employed. This survey has been conducted from a multidisciplinary setting and a qualitative design, using interviews and a semi structured survey. As main outcomes, we have indentified three kinds of barriers: social, personal and domestic/family. At a social level, mothers point out the lack of interest from private corporations, the prevalence of stereotypes and the common belief that disabled people areless productive. At the domestic/family level, most parents are reluctant to agree with the labor integration process, mainly because they think that their children might be abused or deceived by the employers and their teamwork. Therefore, they are extremely cautious when selecting job opportunities. As a personal level, mothers found statements associated to low self-esteem, unsteadiness, lack of autonomy and communicative disabilities.

Formation of spin-polarons in the ferromagnetic Kondo lattice model away from half-filling.

Even though realistic one-dimensional experiments in the field of half-metallic semiconductors are not at hand yet, we are interested in the underlying fundamental physics. In this regard we study a one-dimensional ferromagnetic Kondo lattice model, a model in which a conduction band is coupled ferromagnetically to a background of localized d moments with coupling constant J(H), and investigate the T = 0 phase diagram as a function of the antiferromagnetic interaction J between the localized moments and the band-filling n, since it has been observed that doping of the compounds has led to formation of magnetic domains. We explore the spin-polaron formation by looking at the nearest-neighbour correlation functions in the spin and charge regimes for which we use the density matrix renormalization group method, which is a highly efficient method to investigate quasi-one-dimensional strongly correlated systems.