163 research outputs found

    Qhaway: una herramienta de apoyo para el diagnóstico del glaucoma con aprendizaje profundo

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    Propone un método para el diagnóstico del glaucoma basado en un modelo híbrido de modelos DL, con el cual usando imágenes del fondo de ojo de un paciente se consigue hacer el diagnóstico con alta precisión. Se consideró la integración de los dataset públicos de glaucoma HRF, Drishti-GS1, sjchoi86-HRF, RIM-ONE y ACRIMA, con un total de 1707 imágenes (919 normal y 788 glaucoma) del fondo de ojo, un modelo híbrido de Voting sobre los modelos de DL ResNet50 con dos tipos de fine tuning y ResNet50V2, y la implementación usando Keras y Tensor Flow, con lo que se consiguió un diagnóstico con exactitud del 96.55%, sensibilidad del 98.54% y especificidad del 94.32%. Además, los experimentos numéricos muestran que el aprendizaje usando 5 bases de datos permite mejores resultados que por separado, incluso aplicando transfer learning, también muestran que el modelo híbrido voting genera una exactitud superior en 20.69% a la mejor exactitud obtenido por el mejor modelo de DL (DenseNet169) usando un dataset, 13.22% al mejor modelo (ResNet50V2) usando transfer learning con los 5 datasets, y 1.72% al mejor modelo (ResNet50) considerando los 5 dataset

    Factores motivacionales y su impacto en los indicadores educativos de una IEMS pública

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    Esta investigación muestra los resultados de un estudio cuyo objetivo fue analizar los componentes motivacionales en los directivos, docentes y estudiantes del Centro De Estudios, Tecnológicos, Industrial y de Servicios 72 (CETIS 72) desde su criterio personal. Tiene una forma analítica, además asume un corte transversal. Se empleó la técnica de encuesta, a través de tres cuestionarios: Cuestionario de motivación escolar para los sujetos antes mencionado, el cual está estructurado por tres dimensiones; la primera identifica la importancia que los directivos, docentes y estudiantes  brindan a los aspectos relacionados a la motivación al logro de McClelland; la segunda, evalúa  los factores motivacionales relacionados al desarrollo de las actividades que los directivos, profesores y alumnos, es decir, que tanto se motivan al ejecutar los siguientes aspectos: relacionados con la tarea, relacionado con su ego personal, con la valoración social y la consecución de estímulos externos. Los factores motivacionales presentes en los directivos, docentes y estudiantes del Centro de Estudios Tecnológico Industrial y de Servicios Número 72 es favorable, se encuestó a 6 directivos, 40 docentes y 219 estudiantes de la carrera técnica Administración de Recursos Humanos (TADRH) del CETIS 72, en la investigación se visualiza que los componentes son significativos en la percepción de los factores motivacionales en el ejercicio de sus propias funciones educativas. Por otra parte, las situaciones como status y la edad no representan variaciones significativas en su motivación al logro. Para finalizar, la característica género sí presentó diferencia significativa para dichos factores motivacionales

    Perceptual Anchoring in Preschool Children: Not Adultlike, but There

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    BACKGROUND: Recent studies suggest that human auditory perception follows a prolonged developmental trajectory, sometimes continuing well into adolescence. Whereas both sensory and cognitive accounts have been proposed, the development of the ability to base current perceptual decisions on prior information, an ability that strongly benefits adult perception, has not been directly explored. Here we ask whether the auditory frequency discrimination of preschool children also improves when given the opportunity to use previously presented standard stimuli as perceptual anchors, and whether the magnitude of this anchoring effect undergoes developmental changes. METHODOLOGY/PRINCIPAL FINDINGS: Frequency discrimination was tested using two adaptive same/different protocols. In one protocol (with-reference), a repeated 1-kHz standard tone was presented repeatedly across trials. In the other (no-reference), no such repetitions occurred. Verbal memory and early reading skills were also evaluated to determine if the pattern of correlations between frequency discrimination, memory and literacy is similar to that previously reported in older children and adults. Preschool children were significantly more sensitive in the with-reference than in the no-reference condition, but the magnitude of this anchoring effect was smaller than that observed in adults. The pattern of correlations among discrimination thresholds, memory and literacy replicated previous reports in older children. CONCLUSIONS/SIGNIFICANCE: The processes allowing the use of context to form perceptual anchors are already functional among preschool children, albeit to a lesser extent than in adults. Nevertheless, immature anchoring cannot fully account for the poorer frequency discrimination abilities of young children. That anchoring is present among the majority of typically developing preschool children suggests that the anchoring deficits observed among individuals with dyslexia represent a true deficit rather than a developmental delay

    Gene fusions and gene duplications: relevance to genomic annotation and functional analysis

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    BACKGROUND: Escherichia coli a model organism provides information for annotation of other genomes. Our analysis of its genome has shown that proteins encoded by fused genes need special attention. Such composite (multimodular) proteins consist of two or more components (modules) encoding distinct functions. Multimodular proteins have been found to complicate both annotation and generation of sequence similar groups. Previous work overstated the number of multimodular proteins in E. coli. This work corrects the identification of modules by including sequence information from proteins in 50 sequenced microbial genomes. RESULTS: Multimodular E. coli K-12 proteins were identified from sequence similarities between their component modules and non-fused proteins in 50 genomes and from the literature. We found 109 multimodular proteins in E. coli containing either two or three modules. Most modules had standalone sequence relatives in other genomes. The separated modules together with all the single (un-fused) proteins constitute the sum of all unimodular proteins of E. coli. Pairwise sequence relationships among all E. coli unimodular proteins generated 490 sequence similar, paralogous groups. Groups ranged in size from 92 to 2 members and had varying degrees of relatedness among their members. Some E. coli enzyme groups were compared to homologs in other bacterial genomes. CONCLUSION: The deleterious effects of multimodular proteins on annotation and on the formation of groups of paralogs are emphasized. To improve annotation results, all multimodular proteins in an organism should be detected and when known each function should be connected with its location in the sequence of the protein. When transferring functions by sequence similarity, alignment locations must be noted, particularly when alignments cover only part of the sequences, in order to enable transfer of the correct function. Separating multimodular proteins into module units makes it possible to generate protein groups related by both sequence and function, avoiding mixing of unrelated sequences. Organisms differ in sizes of groups of sequence-related proteins. A sample comparison of orthologs to selected E. coli paralogous groups correlates with known physiological and taxonomic relationships between the organisms

    Induction of B-cell lymphoma by UVB Radiation in p53 Haploinsufficient Mice

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    <p>Abstract</p> <p>Background</p> <p>The incidence of non-Hodgkin's lymphoma has increased over recent years. The exact etiology of lymphoma remains unknown. Ultraviolet light exposure has been associated with the development of internal lymphoid malignancies and some reports suggest that it may play a role in the development of lymphoma in humans. Here we describe the characterization and progression of lymphoma in p53 heterozygous mice exposed to UVB irradiation.</p> <p>Methods</p> <p>UVB-irradiated p53<sup>+/- </sup>mice developed enlargement of the spleen. Isolated spleen cells were transplanted into Rag deficient hosts. The UV-induced tumor cells were analyzed by flow cytometry. The tumor cells were tagged with GFP to study their metastatic potential. SKY and karyotypic analysis were carried out for the detection of chromosomal abnormalities. Functional assays included in vitro class switch recombination assay, immunoglobulin rearrangement assay, as well as cytokine profiling.</p> <p>Results</p> <p>UVB-exposed mice showed enlargement of the spleen and lymph nodes. Cells transplanted into Rag deficient mice developed aggressive tumors that infiltrated the lymph nodes, the spleen and the bone marrow. The tumor cells did not grow in immune competent syngeneic C57Bl/6 mice yet showed a modest growth in UV-irradiated B6 mice. Phenotypic analysis of these tumor cells revealed these cells are positive for B cell markers CD19<sup>+</sup>, CD5<sup>+</sup>, B220<sup>+</sup>, IgM<sup>+ </sup>and negative for T cell, NK or dendritic cell markers. The UV-induced tumor cells underwent robust in vitro immunoglobulin class switch recombination in response to lipopolysaccharide. Cytogenetic analysis revealed a t(14;19) translocation and trisomy of chromosome 6. These tumor cells secret IL-10, which can promote tumor growth and cause systemic immunosuppression.</p> <p>Conclusion</p> <p>UV-irradiated p53<sup>+/- </sup>mice developed lymphoid tumors that corresponded to a mature B cell lymphoma. Our results suggest that an indirect mechanism is involved in the development of internal tumors after chronic exposure to UV light. The induction of B cell lymphoma in UV-irradiated p53 heterozygous mice may provide a useful model for lymphoma development in humans.</p

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Community-based scheduled screening and treatment of malaria in pregnancy for improved maternal and infant health in The Gambia, Burkina Faso and Benin: study protocol for a randomized controlled trial

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    Background: In sub-Saharan Africa, malaria continues to cause over 10,000 maternal deaths and 75,000 to 200,000 infant deaths. Successful control of malaria in pregnancy could save lives of mothers and babies and is an essential part of antenatal care in endemic areas. The primary objective is to determine the protective efficacy of community-scheduled screening and treatment (CSST) using community health workers (CHW) against the primary outcome of prevalence of placental malaria. The secondary objectives are to determine the protective efficacy of CSST on maternal anaemia, maternal peripheral infection, low birth weight, selection of sulfadoxine-pyrimethamine (SP) resistance markers, and on antenatal clinic (ANC) attendance and coverage of intermittent preventive treatment during pregnancy (IPTp-SP).Methods/design: This is a multi-centre cluster-randomised controlled trial involving three countries with varying malaria endemicity; low (The Gambia) versus high transmission (Burkina Faso and Benin), and varying degrees of SP resistance (high in Benin and moderate in Gambia and Burkina Faso). CHW and their related catchment population who are randomised into the intervention arm will receive specific training on community-based case management of malaria in pregnancy. All women in both study arms will be enrolled at their first ANC visits in their second trimester where they will receive their first dose of IPTp-SP. Thereafter, CHW in the intervention arm will perform scheduled monthly screening and treatment in the womens homes. At time of delivery, a placental biopsy will be collected from all women to determine placental malaria. At each contact point, filter paper and blood slides will be collected for detection of malaria infection and SP resistance markers.Discussion: To reach successful global malaria control, there is an urgent need to access those at greatest risk of malaria infection. The project is designed to develop a low-cost intervention in pregnant women which will have an immediate impact on the malaria burden in resource-limited countries. This will be done by adding to the standard IPTp-SP delivered through the health facilities: an "extension" strategy to the communities in rural areas thus bringing health services closer to where women live. Trial registration: Current Controlled Trials: ISRCTN37259296 (5 July 2013), and clinicaltrials.gov: NCT01941264 (10 September 2013)
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