A unique DNA entry gate serves for regulated loading of the eukaryotic replicative helicase MCM2-7 onto DNA.

The regulated loading of the replicative helicase minichromosome maintenance proteins 2–7 (MCM2–7) onto replication origins is a prerequisite for replication fork establishment and genomic stability. Origin recognition complex (ORC), Cdc6, and Cdt1 assemble two MCM2–7 hexamers into one double hexamer around dsDNA. Although the MCM2–7 hexamer can adopt a ring shape with a gap between Mcm2 and Mcm5, it is unknown which Mcm interface functions as the DNA entry gate during regulated helicase loading. Here, we establish that the Saccharomyces cerevisiae MCM2–7 hexamer assumes a closed ring structure, suggesting that helicase loading requires active ring opening. Using a chemical biology approach, we show that ORC–Cdc6–Cdt1-dependent helicase loading occurs through a unique DNA entry gate comprised of the Mcm2 and Mcm5 subunits. Controlled inhibition of DNA insertion triggers ATPase-driven complex disassembly in vitro, while in vivo analysis establishes that Mcm2/Mcm5 gate opening is essential for both helicase loading onto chromatin and cell cycle progression. Importantly, we demonstrate that the MCM2–7 helicase becomes loaded onto DNA as a single hexamer during ORC/Cdc6/Cdt1/MCM2–7 complex formation prior to MCM2–7 double hexamer formation. Our study establishes the existence of a unique DNA entry gate for regulated helicase loading, revealing key mechanisms in helicase loading, which has important implications for helicase activation

LA DIMENSIÓN CONSTITUCIONAL DE LAS INSTITUCIONES NACIONALES DE DERECHOS HUMANOS

Este trabajo aborda la dimensión constitucional de las instituciones nacionales de derechos humanos. En el marco del actual proceso constituyente chileno, el artículo analiza las principales preguntas constitucionales que pueden surgir respecto a la institucionalidad de derechos humanos en Chile, con especial énfasis en la posición y el rol que debiera jugar el actual Instituto Nacional de Derechos Humanos en el futuro orden constitucional. Para ello, y después de analizar la pregunta sobre una eventual autonomía constitucional para una institución nacional de derechos humanos, el artículo reflexiona sobre las principales opciones o posibilidades regulatorias: modelo unipersonal o colegiado; concentración o fragmentación de instituciones; y discusiones generales sobre sus atribuciones.

Severity and duration of allergic conjunctivitis: are they associated with severity and duration of allergic rhinitis and asthma?

Comorbiditat al·lèrgica; Conjuntivitis al·lèrgica; Malaltia respiratòria al·lèrgicaAllergic comorbidity; Allergic conjunctivitis; Allergic respiratory diseaseComorbilidad alérgica; Conjuntivitis alérgica; Enfermedad respiratoria alérgicaObjective. The association of allergic conjunctivitis (AC) with rhinitis and/or asthma is poorly understood. The objective of this study was to apply the Consensus Document for Allergic Conjunctivitis (DECA) criteria for the classification of AC to a population of patients with AC to assess the association between the severity and duration of AC and rhinitis and/or asthma. Methods. Patients with ocular symptoms of AC who participated in the 'Alergológica 2015' study were included. The demographics, classification according to the DECA criteria, etiology, and comorbidities were evaluated by age groups (less or equal than 14 and greater than 14 years). Results. A total of 2,914 patients (age range, 1-90 years) were included in the "Alergológica 2015" study. Of these, 965 patients (33.1%) were diagnosed with AC (77.5% > 14 years). AC was classified as severe, moderate, or mild in 1.8%, 46.4%, and 51.8%, respectively; and as intermittent or persistent in 51.6% and 48.4% of the patients. AC alone occurred in 4% of patients. AC was mainly associated with rhinitis (88.4%), asthma (38.2%), food allergy (8.3%) and atopic dermatitis (3.5%). In allergic respiratory disease rhinitis preceded AC and asthma developed later. The severity and duration of AC was significantly associated with severity and duration of rhinitis (p less than 0.001 for both age groups) and asthma (p less than 0.001 only in adults). Conclusions. The application of the new DECA classification for AC reveals a direct relationship between AC, rhinitis and asthma respect to severity and duration. These relationships suggest that AC should be considered an integral part of the "one airway, one disease" hypothesis

Modelo estadístico de textura para detección de masas en mamografía

In this article we demonstrate the use of principal components analysis to visualizea high dimensional texture representation and understand its geometry. Our targetapplication is mass detection as texture abnormalities. We analyse a texture represen-tation based on the gray levels of a local neighborhood, we estimate a gaussian mixturemodel by means of the EM algorithm and graph the data along with the probabilisticmodel. Our results explain nature of the feature space and at the same time keepsaround 98% of the total variation.Kewords: Biomedical Engineering, Radiodiagnostic, Breast-Cancer, Statistical Meth-ods, Mathematical Models

Integración de la reflexión en la docencia para perfeccionar el proceso de enseñanza-aprendizaje

El presente trabajo tiene como objetivo analizar la importancia de la integración de la reflexión en la docencia para perfeccionar el proceso de enseñanza –aprendizaje. Para ello se ha tenido en cuenta el criterio de varios autores que han investigado sobre el tema en cuestión. Asimismo, en esta investigación se trabajaron los conceptos de reflexión y docencia además de abordar otros términos o categorías que intervienen en la integración de estos dos conceptos como son: proceso de enseñanza-aprendizaje, reflexividad y conocimiento práctico, para una mejor comprensión de la problemática planteada. Cambiar, transformarse, revisar críticamente un proceso es necesario para alcanzar un estadio superior de desarrollo. En el caso de la educación los cambios serían necesarios para luchar contra métodos educativos estáticos y memorísticos. Se necesitan crear espacios de reflexión donde los docentes se analicen y mejoren con sistematicidad, profesionales que impartan sus clases para jóvenes que pertenecen a una sociedad cada vez más compleja y exigente. Palabras clave: Educación, docencia, enseñanza-aprendizaje, reflexión.   ABSTRACT This paper aims to analyze the importance of integrating reflection in teaching to improve the teaching-learning process. For this, the criteria of several authors who have investigated the subject in question have been taken into account. Likewise, in this research were worked on the concepts of reflection and teaching, in addition to addressing other terms or categories that intervene in the integration of these two concepts, such as: teaching-learning process, reflexivity and practical knowledge, for a better understanding of the problem raised. Changing, transforming, critically reviewing a process is necessary to reach a higher stage of development. In the case of education, the changes would be necessary to fight against static and rote educational methods. It is necessary to create spaces for reflection where teachers systematically analyze and improve themselves, professionals who teach their classes for young people who belong to an increasingly complex and demanding society. Keywords: Eeducation, teaching, teaching- learning, reflection

IMPLEMENTACIÓN DE UN PROTOTIPO DE PRUEBA PARA DESARROLLOS EN VISIÓN ARTIFICIAL

RESUMEN  En este artículo se muestra como puede ser implementado un sistema estereoscópico simple usando dos cámaras de televisión, el cual puede ser usado para realizar pruebas en el desarrollo de diferentes proyectos en visión artificial. El sistema implementado usa cámaras fijas y segmentación por color para establecer la correspondencia entre las imágenes, mediante un algoritmo desarrollado en Matlab. La función básica del prototipo es estimar la distancia a la que se encuentran los objetos en un entorno. Con el fin de obtener un buen grado de precisión en la estimación de la distancia, se requiere una calibración adecuada de las cámaras, procedimiento que generalmente resulta bastante complejo. En éste artículo se simplifica la calibración bajo ciertos parámetros, con lo cual el modelo matemático se reduce a un problema de semejanza de triángulos.  PALABRAS CLAVES: Estimación de distancia, Procesamiento de imágenes, Segmentación por color, Visión Artificial, Visión estereoscópica, Visión por computador.  ABSTRACT  This paper shows how a simple stereoscopic system can be implemented using two TV cameras, system that may be used for testing in the development of different projects in computer vision. The implemented system uses fixed cameras and color segmentation to establish the correspondence between the images, using a MatLab developed algorithm. The basic function of the prototype is to estimate the distance at which the objects are in an environment. To get a good degree of accuracy in estimating the distance, it needs a proper calibration of the cameras, procedure which is generally quite complex. In this article the calibration is simplified under certain parameters, reducing the mathematical model to a problem of similarity of triangles.  KEYWORDS: Artificial vision, Color segmentation, Computer vision, Distance estimation, Estereoscopic vision, Image processing. 

IMPLEMENTACIÓN DE UN PROTOTIPO DE PRUEBA PARA DESARROLLOS EN VISIÓN ARTIFICIAL

RESUMEN  En este artículo se muestra como puede ser implementado un sistema estereoscópico simple usando dos cámaras de televisión, el cual puede ser usado para realizar pruebas en el desarrollo de diferentes proyectos en visión artificial. El sistema implementado usa cámaras fijas y segmentación por color para establecer la correspondencia entre las imágenes, mediante un algoritmo desarrollado en Matlab. La función básica del prototipo es estimar la distancia a la que se encuentran los objetos en un entorno. Con el fin de obtener un buen grado de precisión en la estimación de la distancia, se requiere una calibración adecuada de las cámaras, procedimiento que generalmente resulta bastante complejo. En éste artículo se simplifica la calibración bajo ciertos parámetros, con lo cual el modelo matemático se reduce a un problema de semejanza de triángulos.  PALABRAS CLAVES: Estimación de distancia, Procesamiento de imágenes, Segmentación por color, Visión Artificial, Visión estereoscópica, Visión por computador.  ABSTRACT  This paper shows how a simple stereoscopic system can be implemented using two TV cameras, system that may be used for testing in the development of different projects in computer vision. The implemented system uses fixed cameras and color segmentation to establish the correspondence between the images, using a MatLab developed algorithm. The basic function of the prototype is to estimate the distance at which the objects are in an environment. To get a good degree of accuracy in estimating the distance, it needs a proper calibration of the cameras, procedure which is generally quite complex. In this article the calibration is simplified under certain parameters, reducing the mathematical model to a problem of similarity of triangles.  KEYWORDS: Artificial vision, Color segmentation, Computer vision, Distance estimation, Estereoscopic vision, Image processing. 

Managing Achilles Pain (the MAP study) – A process evaluation of data collection methods

Background Process evaluations explore the way in which a study was conducted. The Managing Achilles Pain study (MAP study) had the primary aim of assessing the feasibility of the protocol for a future large longitudinal cohort study that would investigate the association and predictive relationship of self-efficacy, working alliance and expectations with outcome in the management of Achilles tendinopathy. Objectives This study aimed to evaluate the processes conducted in the MAP study by exploring the acceptability of the study procedures from the participants' and physiotherapists' perspectives. Design A qualitative evaluation using semi-structured telephone interviews. Method All physiotherapists and participants who participated in the MAP study were invited. Data from physiotherapists (n = 6) and participants (n = 7) were transcribed and analysed using the Framework Approach. Findings From the physiotherapists' perspective 4 themes were identified relating to obstacles; (1) access to participants; (2) recall; (3) visibility; (4) time, and 4 themes were identified relating to facilitating success; (1) training; (2) motivation; (3) incentives; (4) simplicity. From the participants' perspective 2 themes were identified relating to obstacles; (1) information from the physiotherapist; (2) follow up, 3 themes were identified relating to facilitating success; (1) motivation; (2) website; (3) questionnaire, and 1 theme relating to unintended consequences of participating in the study; positive experience. Conclusions Although clinicians are enthused to be involved in research, organisational factors impact levels of engagement. Key influences to optimising the potential success of a study include the publicising of the study; optimising verbal recruitment strategies; and clarity in communication