5,890 research outputs found

    Analyzing {\gamma}-rays of the Galactic Center with Deep Learning

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    We present a new method to interpret the γ\gamma-ray data of our inner Galaxy as measured by the Fermi Large Area Telescope (Fermi LAT). We train and test convolutional neural networks with simulated Fermi-LAT images based on models tuned to real data. We use this method to investigate the origin of an excess emission of GeV γ\gamma-rays seen in previous studies. Interpretations of this excess include γ\gamma rays created by the annihilation of dark matter particles and γ\gamma rays originating from a collection of unresolved point sources, such as millisecond pulsars. Our new method allows precise measurements of the contribution and properties of an unresolved population of γ\gamma-ray point sources in the interstellar diffuse emission model.Comment: 24 pages, 11 figure

    Análisis estadístico de los resultados de una investigación de los efectos de la influencia de la contaminación atmosférica sobre indicadores biológicos en escolares de sexo masculino

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    Con el objeto de buscar indicadores biológicos humanos de los efectos de la contaminación atmosférica se ha ejecutado un proyecto analítico exploratorio con poblaciones escolares en el centro de la ciudad de Santiago y en la comuna rural de María Pinto (Región Metropolitana). Se trabajó con 114 voluntarios escolares varones entre 10 y 14 años en el Instituto Nacional en Santiago y con un grupo de conrtol, similar, de 51 escolares en María Pinto. En sangre venosa y saliva obtenidas de estos voluntarios se hicieron determinaciones de variables inmunológicas, hematológicas y bioquímicas y medición de la actividad fagocítica del macrófago de sangre periférica. Se hicieron igualmente determinaciones antropométricas. Se determinó también factores de contaminación atmosférica por partículas en ambos lugares: se comprobó que la calidad de aire es significativamente diferente en ellos. Se resumen los resultados globales del proyecto y su análisis estadístico: se discuten tres metodologías alternativas que permitirían tomar en cuenta diferencias de estado nutricional entre ambas poblaciones que pudieran afectar los niveles de respuesta en las variables principales. Las concentraciones de imnunoglobulinas y los factores de complementos C3 y C4 no se muestran como indicadores biológicos efectivos de la contaminación por partículas en la atmósfera. Subsiste la posibilidad de que las variables: capacidad antioxidante del plasma, metahemoglobina, hematocrito, concentración de Fe en materia seca de sangre y otras puedan servir como tales indicadores. Las variaciones conjuntas del índice de fagocitosis y del % de killing evidencian un significativo stress oxidativo

    Differences between Atrial Fibrillation Detected before and after Stroke and TIA: A Systematic Review and Meta-Analysis

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    Background: Preliminary evidence suggests that patients with atrial fibrillation (AF) detected after stroke (AFDAS) may have a lower prevalence of cardiovascular comorbidities and lower risk of stroke recurrence than AF known before stroke (KAF). Objective: We performed a systematic search and meta-analysis to compare the characteristics of AFDAS and KAF. Methods: We searched PubMed, Scopus, and EMBASE for articles reporting differences between AFDAS and KAF until June 30, 2021. We performed random- or fixed-effects meta-analyses to evaluate differences between AFDAS and KAF in demographic factors, vascular risk factors, prevalent vascular comorbidities, structural heart disease, stroke severity, insular cortex involvement, stroke recurrence, and death. Results: In 21 studies including 22,566 patients with ischemic stroke or transient ischemic attack, the prevalence of coronary artery disease, congestive heart failure, prior myocardial infarction, and a history of cerebrovascular events was significantly lower in AFDAS than KAF. Left atrial size was smaller, and left ventricular ejection fraction was higher in AFDAS than KAF. The risk of recurrent stroke was 26% lower in AFDAS than in KAF. There were no differences in age, sex, stroke severity, or death rates between AFDAS and KAF. There were not enough studies to report differences in insular cortex involvement between AF types. Conclusions: We found significant differences in the prevalence of vascular comorbidities, structural heart disease, and stroke recurrence rates between AFDAS and KAF, suggesting that they constitute different clinical entities within the AF spectrum. PROSPERO registration number is CRD42020202622

    Psychometric properties of the Valuing Questionnaire in a Spaniard sample and factorial equivalence with a Colombian sample

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    Background. The Valuing Questionnaire (VQ) is considered as one of the most psychometrically robust instruments to measure valued living according to the acceptance and commitment therapy model. It consists of 10 items that are responded to on a 7-point Likert-type scale and has two factors: Progression and Obstruction. The Spanish version of theVQshowed good psychometric properties in Colombian samples. However, there is no evidence of the psychometric properties of the VQ in Spaniard samples. This study aims to analyze the validity of the VQ in a large Spaniard sample and analyze the measurement invariance with a similar Colombian sample. Method. The VQ was administered to a Spaniard sample of 846 adult participants from general online population. Cronbach's alpha and McDonald's omega were computed to analyze the internal consistency of the VQ. The fit of the VQ's two-factor model was tested through a confirmatory factor analysis with a robust maximum likelihood (MLR) estimation method. Afterward, we analyzed the measurement invariance across countries and gender. Convergent construct validity was analyzed with a package of questionnaires that evaluated experiential avoidance (Acceptance and Action Questionnaire-II, AAQ-II), emotional symptoms (Depression Anxiety and Stress Scale-21, DASS-21), life satisfaction (Satisfaction with Life Scale, SWLS), and cognitive fusion (Cognitive Fusion Questionnaire, CFQ). Results. The internal consistency across samples was adequate (alphas and omegas were .85 for VQ-Progress and .84 for VQ-Obstruction). The two-factor model obtained a good fit to the data (RMSEA D 0.073, 90% CI [0.063, 0.083], CFI D 0.98, NNFI D 0.97, and SRMR D 0.053). The VQ showed strict invariance across countries and gender and showed theoretically coherent correlations with emotional symptoms, life satisfaction, experiential avoidance, and cognitive fusion. In conclusion, the Spanish version of the VQ demonstrated good psychometric properties in a large Spaniard sample

    Psychometric properties of the Automatic Thoughts Questionnaire-8 in two Spanish nonclinical samples

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    Background. The ATQ is a widely used instrument consisting of 30 items that assess the frequency of negative automatic thoughts. However, the extensive length of the ATQ could compromise its measurement efficiency in survey research. Consequently, an 8-item shortened version of the ATQ has been developed. This study aims to analyze the validity of the ATQ-8 in two Spanish samples. Method. The ATQ-8 was administered to a total sample of 1,148 participants (302 undergraduates and 846 general online population). To analyze convergent construct validity, the questionnaire package also included the Dysfunctional Attitude Scale-Revised (DAS-R), Depression Anxiety and Stress Scale-21 (DASS-21), Acceptance Action Questionnaire-II (AAQ-II), Cognitive Fusion Questionnaire (CFQ), Generalized Pliance Questionnaire (GPQ), and Satisfaction with Life Scale (SWLS). To analyze internal consistency, we computed Cronbach's alpha and McDonald's omega. A confirmatory factor analysis was conducted to test the one-factor structure of the ATQ-8. In so doing, a robust diagonally weighted least square estimation method (Robust DWLS) was adopted using polychoric correlations. Afterward, we analyzed measurement invariance across samples, gender, groupage, and education level. Lastly, we evaluated convergent construct validity by computing Pearson correlations between the ATQ-8 and the remaining instruments. Results. The internal consistency across samples was adequate (alpha and omega D .89). The one-factor model demonstrated a good fit to the data (RMSEAD0.10, 90% CI [0.089, 0.112], CFID0.98, NNFID0.97, andSRMRD0.048). The ATQ-8 showed scalar metric invariance across samples, gender, groupage, and education level. The ATQ-8 scores were significantly associated with emotional symptoms (DASS-21), satisfaction with life (SWLS), dysfunctional schemas (DAS-R), cognitive fusion (CFQ), experiential avoidance (AAQ-II), and generalized pliance (GPQ). In conclusion, the Spanish version of the ATQ-8 demonstrated adequate psychometric properties in Spanish samples

    Diferencias en la distribución de las variantes de hemoglobina según las regiones geográficas en una población colombiana

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    Introducción Colombia ha estado Introducción Colombia ha estado sometida a intensas corrientes genéticas y culturales debido a su ubicación geográfica. Las hemoglobinopatías son las enfermedades recesivas más frecuentes en todo el mundo y representan un importante problema de salud pública, según la región y la ascendencia de cada país. Objetivos Evaluar la frecuencia de variantes de hemoglobina según la región geográfica en un grupo poblacional ajustado por sexo y edad en Colombia. Métodos Fue un estudio descriptivo retrospectivo de variantes de hemoglobina realizado por electroforesis en pacientes atendidos y/o remitidos a instituciones de atención especializada en Bogotá, Colombia entre enero de 2009 y diciembre de 2020. Resultados Se analizaron 2.224 resultados, 48,4% hombres y 51,5% mujeres; 63,3% de los pacientes fueron sin alteraciones, 14,3% presentaron talasemia, 17,3%, HbS, 2,3%, HbS/C, 1,8%, HbC, 0,5%, HbE y 0,5% HbF persistente, siendo la HbS más prevalente en hombres (p = 0,005). Al evaluar las regiones geográficas de Colombia, se encontró una mayor prevalencia de HbS en las regiones Pacífica (p = 0,005) y Caribe, mientras que la Talasemia y la HbS fueron más prevalentes en las regiones Andina y Orinoquia, y fue raro encontrar alguna hemoglobinopatía (p = 0,0001) en la región Amazónica. Conclusiones Las principales hemoglobinopatías encontradas en Colombia son la HbS, predominantemente en varones, y la Talasemia. La distribución de las hemoglobinopatías en las diferentes regiones geográficas de Colombia está influenciada por la ancestralidad.Sujeta a intensas corrientes genéticas y culturales debido a su ubicación geográfica. Las hemoglobinopatías son las enfermedades recesivas más frecuentes a nivel mundial y representan un importante problema de salud pública, según la región y la ancestralidad de cada país. Objetivos Evaluar la frecuencia de variantes de hemoglobina según la región geográfica en un grupo poblacional ajustado por sexo y edad en Colombia. Métodos Fue un estudio descriptivo retrospectivo de variantes de hemoglobina realizado por electroforesis en pacientes atendidos y/o remitidos a instituciones de atención especializada en Bogotá, Colombia entre enero de 2009 y diciembre de 2020. Resultados Se analizaron 2.224 resultados, 48,4% hombres y 51,5% mujeres; 63,3% de los pacientes fueron sin alteraciones, 14,3% presentaron talasemia, 17,3%, HbS, 2,3%, HbS/C, 1,8%, HbC, 0,5%, HbE y 0,5% HbF persistente, siendo la HbS más prevalente en hombres (p = 0,005). Al evaluar las regiones geográficas de Colombia, se encontró una mayor prevalencia de HbS en las regiones Pacífica (p = 0,005) y Caribe, mientras que la Talasemia y la HbS fueron más prevalentes en las regiones Andina y Orinoquia, y fue raro encontrar alguna hemoglobinopatía (p = 0,0001) en la región Amazónica. Conclusiones Las principales hemoglobinopatías encontradas en Colombia son la HbS, predominantemente en varones, y la Talasemia. La distribución de las hemoglobinopatías en las diferentes regiones geográficas de Colombia está influenciada por la ascendencia.Introduction Colombia has been Introduction Colombia has been subject to intense genetic and cultural currents due to its geographical location. Hemoglobinopathies are the most common recessive diseases found worldwide and represent an important public health problem, according to the region and ancestry of each country. Objectives To evaluate the frequency of hemoglobin variants according to the geographical region in a population group adjusted to sex and age in Colombia. Methods This was a descriptive retrospective study of hemoglobin variants performed by electrophoresis in patients treated at and/or referred to specialized care institutions in Bogota, Colombia between January 2009 and December 2020. Results A total of 2,224 results were analyzed, 48.4% male and 51.5% female; 63.3% of patients were without alterations, 14.3% presented with thalassemia, 17.3%, HbS, 2.3%, HbS/C, 1.8%, HbC, 0.5%, HbE and 0.5% persistent HbF, with HbS being more prevalent in males (p = 0.005). When assessing the geographical regions of Colombia, a higher prevalence of HbS was found in the Pacific (p = 0.005) and Caribbean regions, while Thalassemia and HbS were more prevalent in the Andean and Orinoquia regions, and it was rare to find any hemoglobinopathies (p = 0.0001) in the Amazonian region. Conclusions The main hemoglobinopathies found in Colombia are HbS, predominantly in males, and Thalassemia. The distribution of hemoglobinopathies in different geographical regions of Colombia is influenced by ancestry.subject to intense genetic and cultural currents due to its geographical location. Hemoglobinopathies are the most common recessive diseases found worldwide and represent an important public health problem, according to the region and ancestry of each country. Objectives To evaluate the frequency of hemoglobin variants according to the geographical region in a population group adjusted to sex and age in Colombia. Methods This was a descriptive retrospective study of hemoglobin variants performed by electrophoresis in patients treated at and/or referred to specialized care institutions in Bogota, Colombia between January 2009 and December 2020. Results A total of 2,224 results were analyzed, 48.4% male and 51.5% female; 63.3% of patients were without alterations, 14.3% presented with thalassemia, 17.3%, HbS, 2.3%, HbS/C, 1.8%, HbC, 0.5%, HbE and 0.5% persistent HbF, with HbS being more prevalent in males (p = 0.005). When assessing the geographical regions of Colombia, a higher prevalence of HbS was found in the Pacific (p = 0.005) and Caribbean regions, while Thalassemia and HbS were more prevalent in the Andean and Orinoquia regions, and it was rare to find any hemoglobinopathies (p = 0.0001) in the Amazonian region. Conclusions The main hemoglobinopathies found in Colombia are HbS, predominantly in males, and Thalassemia. The distribution of hemoglobinopathies in different geographical regions of Colombia is influenced by ancestry
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