Nature of the Neurotoxic Membrane Actions of Amyloid-β on Hippocampal Neurons in Alzheimer\u27s Disease

The mechanism by which amyloid-β (Aβ) produces brain dysfunction in patients with Alzheimer\u27s disease is largely unknown. According to previous studies, Aβ might share perforating properties with gramicidin, a well-accepted membrane-disrupting peptide. Therefore, we hypothesize that the key steps leading to synaptotoxicity by Aβ and gramicidin involve peptide aggregation, pore formation, and calcium dysregulation. Here, we show that Aβ and gramicidin form aggregates enriched in β-sheet structures using electron microscopy, and Thioflavin and Congo Red staining techniques. Also, we found that Aβ and gramicidin display fairly similar actions in hippocampal cell membranes, i.e. inducing Ca2+ entry and synaptoxicity characterized by the loss of synaptic proteins and a decrease in neuronal viability. These effects were not observed in a Ca2+ free solution, indicating that both Aβ and gramicidin induce neurotoxicity by a Ca2+-dependent mechanism. Using combined perforated patch clamp and imaging recordings, we found that only Aβ produced a perforation that progressed from a small (Cl−-selective pore) to a larger perforation that allowed the entry of fluorescent molecules. Therefore, based on these results, we propose that the perforation at the plasma membrane by Aβ is a dynamic process that is critical in producing neurotoxicity similar to that found in the brains of AD patients

Contralateral asymmetry for breast cancer detection : A CADx approach

Early detection is fundamental for the effective treatment of breast cancer and the screening mammography is the most common tool used by the medical community to detect early breast cancer development. Screening mammograms include images of both breasts using two standard views, and the contralateral asymmetry per view is a key feature in detecting breast cancer. we propose a methodology to incorporate said asymmetry information into a computer-aided diagnosis system that can accurately discern between healthy subjects and subjects at risk of having breast cancer. Furthermore, we generate features that measure not only a view-wise asymmetry, but a subject-wise one. Briefly, the methodology co-registers the left and right mammograms, extracts image characteristics, fuses them into subjectwise features, and classifies subjects. In this study, 152 subjects from two independent databases, one with analog- and one with digital mammograms, were used to validate the methodology. Areas under the receiver operating characteristic curve of 0.738 and 0.767, and diagnostic odds ratios of 23.10 and 9.00 were achieved, respectively. In addition, the proposed method has the potential to rank subjects by their probability of having breas

Incorporating Breast Asymmetry Studies into CADx Systems

Breast cancer is one of the global leading causes of death among women, and an early detection is of uttermost importance to reduce mortality rates. Screening mammograms, in which radiologists rely only on their eyesight, are one of the most used early detection methods. However, characteristics, such as the asymmetry between breasts, a feature that could be very difficult to visually quantize, is key to breast cancer detection. Due to the highly heterogeneous and deformable structure of the breast itself, incorporating asymmetry measurements into an automated detection system is still a challenge. In this study, we proposed the use of a bilateral registration algorithm as an effective way to automatically measure mirror asymmetry. Furthermore, this information was fed to a machine learning algorithm to improve the accuracy of the model. In this study, 449 subjects (197 with calcifications, 207 with masses, and 45 healthy subjects) from a public database were used to train and evaluate the proposed methodology. Using this procedure, we were able to independently identify subjects with calcifications (accuracy = 0.825, AUC = 0.882) and masses (accuracy = 0.698, AUC = 0.807) from healthy subjects

Software de gamificación institución educativa Silvania

Este trabajo está basado en el prototipo de software con metodología gamificada aplicado en la institución educativa Silvania del Municipio de Gigante Huila, utilizando elementos y principios de diseño de juegos en entorno educativo, con el objetivo de resolver problemas matemáticos básicos en los estudiantes del grado tercero. Durante la aplicación de los mecanismos de juego en el contexto educativo permitió desarrollar el proceso de enseñanza en un ambiente motivante y colaborativos, conllevando a realizar ejercicios prácticos y fortalecer habilidades matemáticas en los estudiantes. Para el desarrollo de este micro proyecto fue importante identificar unas bases teóricas, conocer e identificar conceptos de la gamificación, sus características, su funcionalidad, así como el modelo exelearnig y el modelo coda.This work is based on the software prototype with gamified methodology applied in the Silvania educational institution of the Municipality of Gigante Huila, using elements and principles of game design in an educational environment, with the objective of solving basic mathematical problems in third grade students. . During the application of game mechanisms in the educational context, it allowed the teaching process to be developed in a motivating and collaborative environment, leading to practical exercises and strengthening mathematical skills in students. For the development of this micro project it was important to identify theoretical bases, know and identify concepts of gamification, its characteristics, its functionality, as well as the exelearnig model and the coda model.Introducción -- Planteamiento del Problema -- Justificación -- Objetivos -- General -- Específicos -- Bases Teóricas -- Antecedentes -- Marco Teórico -- Gamificación -- Características de la Gamificación -- Importancia de las matemáticas en el grado tercero de la Institución Educativa Silvania -- Exelearning y su funcionalidad para el proceso de aula -- Modelo CODA - Calidad de objetos de Aprendizajes -- Marco Conceptual -- Metodología -- Población -- Muestra -- Requerimientos -- Características mínimas de los equipos de cómputo -- Desarrollo Prototipo de Software -- Instalación del aplicativo exelearning -- Pasos para la instalación de la herramienta bajo sistema operativo Windows -- Desarrollo del contenido -- Prueba N. 1. -- Prueba 2 -- Implementación del Prototipo de Software -- Evaluación del prototipo de software -- Plantilla de evaluación de la calidad -- Aplicación de la herramienta de evaluación -- Resultado de la evaluación de la herramienta de evaluación -- Cronograma de Actividades -- Presupuesto -- Conclusiones -- Bibliografía --Pregrad

Cariotipo del tití gris (Saguinus leucopus): similitudes con el cariotipo humano

White-footed Tamarin (Saguinus leucopus) is a primate endemic to Colombia whose karyotype is described in this study from a pair of individuals located in the East of Caldas Wild Fauna Rehabilitation Center in Colombia. The blood samples were collected from the femoral vein and anti-coagulated with heparin sodium. The chromosomes obtained by the classic method of culture of lymphocytes as well as Q and G banding. The individuals display 46 chromosomes (2n = 46: 30Bi, 14A); sexual chromosomes XX in female and XY in the male (chimerism 46, XX/46, XY in this last one). An ideogram for the White-footed Tamarin karyotype is proposed. Ample similarities in S. leucopus chromosomes Xy 5 are observed and with human chromosomes Xy 19, respectively. Other partial similarities were demonstrated between chromosomes 1 of both species, S. leucopus 2 and 14 with human 7. The comparison of the size of exonic regions of two genes of S. leucopus and Homo sapiens did not show any difference.El tití gris (Saguinus leucopus) es un primate endémico de Colombia cuyo cariotipo se describe en el presente estudio a partir de una pareja de individuos ubicados en el Centro de Rehabilitación de Fauna Silvestre del Oriente de Caldas, Colombia. Las muestras de sangre fueron recolectadas de la vena femoral y anticoaguladas con heparina de sodio. Los cromosomas se obtuvieron por el método clásico de cultivo de linfocitos y bandeamiento Q y G Los individuos presentan 46 cromosomas (2n = 46: 30Bi, 14A); cromosomas sexuales XX en la hembra y XY en el macho (quimerismo 46,XX/46,XY en este último). Se propone un ideograma para el cariotipo del Tití Gris. Se observan amplias semejanzas en los cromosomas X y 5 de S. leucopus con los cromosomas X y 19 humanos, respectivamente. Otras similitudes parciales se evidenciaron entre los cromosomas 1 de ambas especies, 2 y 14 de S. leucopus con el 7 humano. La comparación del tamaño de regiones exónicas de dos genes de S. leucopus y Homo sapiens no arrojó diferencia

Análisis de la evolución del conocimiento preventivo y su práctica entre la población de Colombia hacia la enfermedad por Coronavirus (Covid-19)

La presente investigación muestra la evolución que ha presentado el conocimiento y práctica de las recomendaciones dadas por la Organización Mundial de la Salud para la prevención de la Covid-19 en comparación al estudio realizado por Rivera-Diaz et al. Se encuetaron 478 personas, los resultados mostraron que un alto porcen-taje conoce y pone en práctica las recomendaciones de la OMS indistintamente del sexo del individuo. Además, el estudio evidencia la problemática relacionada con el consumo de sustancias o medicamentos para la prevención de la Covid-19, que pueden poner en serios riesgos la salud de quien los consume; de otro lado, el uso de plantas medicinales también demuestra ser una práctica muy común en la población.This research shows the evolution that has been presented by the knowledge and practice by part of the people of the recommendations given by the World Health Organization for the prevention of Covid-19 compared to the study carried out by Rivera-Diaz et al. 478 people were surveyed, the results showed that a high percentage knows and puts into practice the WHO recommendations regardless of the sex of the individual. In addition, the study shows the problems related to the consumption of substances and / or medications for the prevention of Covid-19, which can put the health of those who consume them at serious risk; on the other hand, the use of medicinal plants also proves to be a very common practice in the population.https://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0001402116https://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0001540415https://orcid.org/0000-0002-4835-9739https://orcid.org/0000-0002-2582-2495https://scienti.minciencias.gov.co/gruplac/jsp/visualiza/visualizagr.jsp?nro=00000000004151https://scienti.minciencias.gov.co/gruplac/jsp/visualiza/visualizagr.jsp?nro=00000000019115danielr.ricardo@[email protected]://scholar.google.com/citations?user=OW0mejcAAAAJ&hl=eshttps://scholar.google.es/citations?user=RoziXGMAAAAJ&hl=e

Análisis de la evolución del conocimiento preventivo y su práctica entre la población de Colombia hacia la enfermedad por Coronavirus (Covid-19)

La presente investigación muestra la evolución que ha presentado el conocimiento y práctica de las recomendaciones dadas por la Organización Mundial de la Salud para la prevención de la Covid-19 en comparación al estudio realizado por RiveraDiaz et al. Se encuetaron 478 personas, los resultados mostraron que un alto porcentaje conoce y pone en práctica las recomendaciones de la OMS indistintamente del sexo del individuo. Además, el estudio evidencia la problemática relacionada con el consumo de sustancias o medicamentos para la prevención de la Covid-19, que pueden poner en serios riesgos la salud de quien los consume; de otro lado, el uso de plantas medicinales también demuestra ser una práctica muy común en la población.The present investigation shows the evolution that has presented the knowledge and practice of the recommendations given by the World Health Organization for the prevention of Covid-19 compared to the study carried out by RiveraDiaz et al. 478 people were surveyed, the results showed that a high percentage knows and puts into practice the recommendations of the WHO regardless of the individual's sex. In addition, the study evidences the problems related to the consumption of substances or medicines for the prevention of Covid-19, which they can seriously risk the health of those who consume them; on the other hand, the use of medicinal plants also proves to be a very common practice in the population