3,615 research outputs found
De Castella vetula : (hojas de un libro de viajes)
Copia digital. Valladolid : Junta de Castilla y León. ConsejerÃa de Cultura y Turismo, 2009-201
Reconocimiento de depresión en redes sociales basado en la detección de sÃntomas
Depression is a common mental disorder that affects millions of people around the world. Recently, several methods have been proposed that detect people suffering from depression by analyzing their language patterns in social media. These methods show competitive results, but most of them are opaque and lack of explainability. Motivated by these problems, and inspired by the questionnaires used by health professionals for its diagnosis, in this paper we propose an approach for the detection of depression based on the identification and accumulation of evidence of symptoms through the users’ posts. Results in a benchmark collection are encouraging, as they show a competitive performance with respect to state-of-the-art methods. Furthermore, taking advantage of the approach’s properties, we outline what could be a support tool for healthcare professionals for analyzing and monitoring depression behaviors in social networks.La depresión es un trastorno mental que afecta a millones de personas en todo el mundo. Recientemente, se han propuesto varios métodos que detectan personas que sufren depresión analizando sus patrones de lenguaje en las redes sociales. Estos métodos han mostrado resultados competitivos, sin embargo la mayorÃa son opacos y carecen de explicabilidad. Motivados por estos problemas, e inspirados en los cuestionarios utilizados por los profesionales de la salud para su diagnóstico, en este trabajo proponemos un método para la detección de depresión basado en la identificación y acumulación de evidencia de sÃntomas a través de las publicaciones de los usuarios. Los resultados obtenidos en una colección de referencia son prometedores, ya que muestran un desempeño competitivo con respecto a los mejores métodos actuales. Además, aprovechando las propiedades del método, describimos lo que podrÃa ser una herramienta de apoyo para que los profesionales de la salud analicen y monitoreen las conductas depresivas en las redes sociales
Convergence and Perturbation Resilience of Dynamic String-Averaging Projection Methods
We consider the convex feasibility problem (CFP) in Hilbert space and
concentrate on the study of string-averaging projection (SAP) methods for the
CFP, analyzing their convergence and their perturbation resilience. In the
past, SAP methods were formulated with a single predetermined set of strings
and a single predetermined set of weights. Here we extend the scope of the
family of SAP methods to allow iteration-index-dependent variable strings and
weights and term such methods dynamic string-averaging projection (DSAP)
methods. The bounded perturbation resilience of DSAP methods is relevant and
important for their possible use in the framework of the recently developed
superiorization heuristic methodology for constrained minimization problems.Comment: Computational Optimization and Applications, accepted for publicatio
Fodder and Grain Yield in Native Maize (Zea mays L.)
The objective of the present study was to quantify in 7 varieties of native or landrace corn (Zea mays L): grain yield, biomass, stubble and leaf: stem index; as well as the relationship between biomass, stubble and plant height.
.Design / methodology / approach: The treatments consisted in the sowing of seven cultivars of native corn (Zea mays L.). The experimental design was randomized blocks with four repetitions. The height of the plant, total biomass, its accumulation in stem, sheets, bracts, cob, grain and stubble (stem biomass + sheets + bracts + cob) were evaluated. An analysis of variance, the Tukey mean comparison test, and a regression analysis were applied.
Results: Significant differences were found between native corn cultivars for the variables under study. The outstanding ones were Yellow from Ixtenco, followed in terms of biomass and stubble by Blanco-ancho from Texcoco, Blanco and Rojo from Ixtenco. The height of the plant determined the biomass in 67% and the stubble in 77%.
Study limitations / implications: The trends found may vary depending on the native cultivars studied and their management.
Findings / conclusions: In the study region, there are differences between native maize cultivars for the agronomic characteristics evaluated. In relation to grain yield, biomass and stubble, the cultivar Amarillo from Ixtenco was the outstanding one, followed by Blanco-ancho from Texcoco, Blanco and Rojo from Ixtenco. The height of the plant determined in 67% and 77% the amount of stubble and biomass.Objective: To quantify the grain yield, biomass, crop stubble, and leaf:stalk index in seven varieties of maize (Zea mays L.), as well as the relationship between biomass, stubble, and plant height.
Design/Methodology/Approach: The process consisted in planting seven genotypes of native maize (Zea mays L.). The experimental design comprised randomized blocks with four repetitions. The plant’s height, total biomass, its accumulation in stalk, leaf, husk, cob, grain, and stubble (biomass of stalk?leaf?husk?cob) were evaluated. A varianceanalysis, the Tukey means comparison test, and a regression analysis were applied.
Results: Significant differences were found between the native maize genotypes. Notable cases were the Ixtenco Yellow, followed in terms of biomass and stubble by the Texcoco White-Wide, then the Ixtenco White and Red. The plant height determined biomass in 67% and stubble in 77%.
Study Limitations/Implications: The tendencies found could vary depending on the native cultivars studied and their management.
Findings/Conclusions: In the study region, there are differences between native maize cultivars for the agronomic characteristics evaluated. With respect to the yield of grain, biomass, and stubble, the Ixtenco Yellow cultivar was outstanding, followed by the Texcoco White-Wide, and Ixtenco White and Red. The plant height determined biomass in 67%, and stubble quantity in 77%
Inclusión educativa: Estrategias de aprendizaje implementadas por el personal docente en la UCA en 2020-2022
The transcription factor Spores Absent A is a PKA dependent inducer of Dictyostelium sporulation
Abstract Sporulation in Dictyostelium fruiting bodies evolved from amoebozoan encystation with both being induced by cAMP acting on PKA, but with downstream components still being unknown. Using tagged mutagenesis to find missing pathway components, we identified a sporeless mutant defective in a nuclear protein, SpaA. Expression of prespore genes was strongly reduced in spaA- cells, while expression of many spore stage genes was absent. Chromatin immunoprecipitation (ChIP) of a SpaA-YFP gene fusion showed that (pre)spore gene promoters bind directly to SpaA, identifying SpaA as a transcriptional regulator. SpaA dependent spore gene expression required PKA in vivo and was stimulated in vitro by the membrane-permeant PKA agonist 8Br-cAMP. The PKA agonist also promoted SpaA binding to (pre)spore promoters, placing SpaA downstream of PKA. Sequencing of SpaA-YFP ChIPed DNA fragments revealed that SpaA binds at least 117 (pre)spore promoters, including those of other transcription factors that activate some spore genes. These factors are not in turn required for spaA expression, identifying SpaA as the major trancriptional inducer of sporulation
Resumen de la Tarea DA-VINCIS en IberLEF 2022: Detección de Incidentes Violentos en Redes Sociales en Español
This paper presents the overview of the DA-VINCIS 2022 task, organized at IberLEF 2023 and co-located with the 38th International Conference of the Spanish Society for Natural Language Processing (SEPLN 2022). DA-VINCIS challenged participants to develop automated solutions for the detection of violent events mentioned in social networks. We released a novel corpus collected from Twitter and manually labeled with 4 categories of violent incidents (plus the no-incident label). The shared task focused on the Mexican variant of Spanish and it was divided into two tracks: (1) a binary classification task in which users had to determine whether tweets were associated to a violent incident or not; and (2) a multi-label classification task in which the category of the violent incident should be spotted. More than 40 teams registered for the task and 12 participants submitted predictions for the final phase. Very competitive results were reported in both sub tasks, where transformer-based solutions obtained the best results. Corpora and results are available at the shared task website at https://codalab.lisn.upsaclay.fr/competitions/2638.Se presenta el resumen de la tarea DA-VINCIS 2022, organizada en IberLEF 2022 junto a la 38ª Conferencia Internacional de la Sociedad Española para el Procesamiento del Lenguaje Natural (SEPLN 2022). DA-VINCIS plantea el reto de detectar automáticamente piezas de información en redes sociales que estén asociadas a eventos violentos. Se liberó un nuevo corpus para el Español Mexicano que fue etiquetado manualmente con 4 categorÃas de eventos violentos (además de la categorÃa no-violento). Se propusieron dos subtareas: (1) una tarea de clasificación binaria donde se buscaba distinguir tuits asociados a eventos violentos del resto; y otra (2) donde se buscaba identificar la categorÃa del evento violento. Más de 40 participantes se registraron en el portal y 12 enviaron resultados para la fase final. Los resultados obtenidos fueron muy competitivos para ambas tareas; las soluciones que obtuvieron los mejores resultados se basaron en modelos tipo transformer para el español. El corpus y los resultados detallados pueden consultarse en el sitio web de la tarea: https://codalab.lisn.upsaclay.fr/competitions/2638.This work was supported by CONACyT under grant CB-S-26314, Integración de Lenguaje y Visión mediante Representaciones Multimodales Aprendidas para Clasificación y Recuperación de Imágenes. We also would like to thank CONACyT for partially supporting this work under grant CB-2015-01-257383
Hidratación y microestructura de cemento Portland sustituido parcialmente con sÃlice ultrafina
Geothermal waste, a by-product of steam power plants that use geothermal underground resources, was studied as a possible replacement for Portland cement. This waste consists primarily in amorphous nanometric silica with traces of sodium and potassium chlorides. The replacement ratios studied were 0, 10 and 20% in cements cured at 20 and 60 ºC. X-ray diffraction analysis showed that clinker phase hydration took place earlier in the presence of the geothermal waste. Scanning electron microscopy, in turn, revealed a reduction in porosity and intense calcium hydroxide consumption as a result of the pozzolanic reaction. The pastes containing 20% waste, however, an intense cracking was observed due to the formation of alkali silica reaction gel and ettringite. Cracking was more prominent at 60 ºC but was not observed in either the neat cement or the blend with 10 % waste. The presence of these detrimental phases was attributed to the formation of Friedel’s salt in the initial hydration stages, induced by the chlorides in the geothermal material.Se investigaron pastas de cemento Portland sustituido con un desecho geotérmico, subproducto de la generación de electricidad en plantas que emplean recursos geotérmicos. El desecho está compuesto principalmente de sÃlice amorfa de tamaño nanométrico, con cloruros de sodio y potasio. Se investigaron cementos con niveles de substitución de 0, 10 y 20%, curados a 20 y 60 °C. En presencia del desecho geotérmico, se observó por Difracción de rayos X cuantitativa que la hidratación de las fases del clÃnker se aceleró; además mediante microscopÃa electrónica de barrido se encontró una disminución en la porosidad y un intenso consumo de hidróxido de calcio por la reacción puzolánica. Sin embargo, para pastas con 20% de desecho geotérmico, se observó agrietamiento con la presencia de gel de reacción álcali sÃlice y ettringita; fue más acentuado a 60 °C y no se observó para pastas de cemento puro y con 10% de desecho. La presencia de las fases nocivas se atribuye a la formación de sal de Friedel en las etapas iniciales de hidratación, promovida por los cloruros provenientes del desecho geotérmico
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