45 research outputs found
Throughput maximization using reinforcement learning for LEO Satellite Communications
No full textFil: Pasquevich, Felipe. Comisión Nacional de Actividades Espaciales de Argentina. Centro Espacial Teófilo Tabanera - Córdoba; Argentina.Fil: Ayarde, Martín. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Mondino Llermanos, Yasmín. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Bossa, Celina. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Ibañez, Ignacio. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Smrekar, Marcelo. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Rodriguez, Andrés. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Corral Briones, Graciela. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Abstract
Low Earth Orbit (LEO) satellites demand progressively higher data transfer rates to download the amount of data generated by the satellite’s instruments, such as hyperspectral cameras or synthetic aperture radars. In this paper a solution to maximize the throughput is proposed. The core idea of this method is to specify a reward that evaluates the packet error rate and the modulation applied. By using the Q-Learning algorithm, the agent learns to select the correct modulation scheme dynamically. To tackle the problem of an infinite state space, a simple yet efficient state aggregation strategy is proposed. The scenario simulated is built from a real Two-Line Element (TLE), belonging to the Argentine SAOCOM-1B satellite and the ground station located at Cordoba, Argentina. The channel model assumes a Free Space Path Loss (FSPL) and a steerable antenna, with its respective associated radiation pattern. There are 4 possible modulations: Q-PSK, 8-PSK, 16-QAM and 32-QAM. We show that the proposed algorithm is able to learn the actions to steer the antenna and also select the appropriate modulation to obtain the maximum throughput.Fil: Pasquevich, Felipe. Comisión Nacional de Actividades Espaciales de Argentina. Centro Espacial Teófilo Tabanera - Córdoba; Argentina.Fil: Ayarde, Martín. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Mondino Llermanos, Yasmín. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Bossa, Celina. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Ibañez, Ignacio. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Smrekar, Marcelo. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Rodriguez, Andrés. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Corral Briones, Graciela. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina
Evolucion de pacientes mayores de 60 años, operados de cambio valvular aortico en el Instituto Nacional de Cardiologia
No full textSHARDS: constraints on the dust attenuation law of star-forming galaxies at z ∼ 2
No full textWe make use of the Survey of High-z Absorption Red and Dead Sources, an ultradeep
(<26.5AB) galaxy survey that provides optical photospectra at resolution R ∼ 50, via mediumband
filters (FWHM ∼ 150 Å). This data set is combined with ancillary optical and NIR fluxes
to constrain the dust attenuation law in the rest-frame NUV region of star-forming galaxies
within the redshift window 1.5 < z < 3. We focus on the NUV bump strength (B) and the
total-to-selective extinction ratio (RV), targeting a sample of 1753 galaxies. By comparing the
data with a set of population synthesis models coupled to a parametric dust attenuation law, we
constrain RV and B, as well as the colour excess, E(B − V). We find a correlation between RV
and B, which can be interpreted either as a result of the grain size distribution, or a variation of
the dust geometry among galaxies. According to the former, small dust grains are associated
with a stronger NUV bump. The latter would lead to a range of clumpiness in the distribution
of dust within the interstellar medium of star-forming galaxies. The observed wide range of
NUV bump strengths can lead to a systematic in the interpretation of the UV slope β typically
used to characterize the dust content. In this study, we quantify these variations, concluding
that the effects are β ∼ 0.4
Estrategias de aprendizaje y desempeño docente en la satisfacción académica en universitarios de Lima
No full textAcademic satisfaction in university students has been studied linking with contextual factors of the educational environment, among others, the teaching of the teacher, support in adaptation, as well as personal factors of the student. The purpose of this study was to estimate the prediction of the influence of student study strategies and teacher performance on the academic satisfaction of psychology students from two public universities in Lima, Peru. 161 university students of the degree in psychology participated, from two public universities in Lima, 46 men and 115 women, who answered three self-report scales, one on learning strategies, another on the performance of their teachers, and the third on academic satisfaction. The three scales obtained high internal consistency indices. The method used includes a non-experimental, explanatory design, to determine the incidence of the variables study strategies and teaching performance, on the variable academic satisfaction, through linear regression analysis. The results showed that, with a statistical significance level of 5% (p < .000), the two predictor variables significantly affected academic satisfaction. Based on the results, it is concluded that teaching performance and student learning strategies have a significant impact on the academic satisfaction of psychology students at two public universities in Metropolitan Lima.La satisfacción académica en estudiantes universitarios ha sido estudiada vinculando con factores contextuales del ambiente educativo, entre otros, la enseñanza del docente, apoyo en la adaptación, así como factores personales del estudiante. El propósito de este estudio fue estimar la predicción de la influencia de las estrategias de aprendizaje del alumnado y el desempeño docente sobre la satisfacción académica de estudiante de psicología de dos universidades públicas de Lima, Perú. Participaron 161 estudiantes de universitarios de la licenciatura en psicología, de dos universidades públicas de Lima, 46 hombres y 115 mujeres, quienes respondieron tres escalas de auto reporte, uno sobre estrategias de aprendizaje, otro sobre desempeño de sus docentes y el tercero sobre satisfacción académica. Las tres escalas obtuvieron índices de consistencia interna alta. El método empleado comprende un diseño no experimental, explicativo, para determinar la incidencia de las variables estrategias de estudio y desempeño docente, sobre la variable satisfacción académica, a través del análisis de regresión lineal. Los resultados mostraron que, con un nivel de significancia estadística del 5% p < .001, las dos variables predictoras afectaron significativamente a la satisfacción académica. A partir de los resultados se concluye que el desempeño docente y las estrategias de aprendizaje del alumnado inciden significativamente en la satisfacción académica de los estudiantes de psicología en dos universidades públicas de Lima Metropolitana
Garotas da colônia: aprender e trabalhar na infância rural
No full textNeste trabalho, analiso, a partir de posições regulacionistas a respeito do trabalho infantil, as participações das meninas nas atividades agrícolas em San Ignacio (Missões, Argentina). A partir de referências a um trabalho de campo etnográfico iniciado em 2009, considero como sua incorporação nos fazeres cotidianos dos sítios pode entender-se como experiências formativas, isto é, como parte de um processo de aquisição progressiva de autonomia para o próprio sustento, onde as distinções étnicas, genéricas, de idade e posição social definem certas atividades e saberes como próprios das “garotas do campo”. Esses conhecimentos sobre o mundo são os que lhes permitem entender, mas também transformar imperceptivelmente e em seu fazer quotidiano, o mundo que as rodeia.En este trabajo analizo, a partir de posiciones regulacionistas respecto del trabajo infantil, las participaciones de las niñas en las actividades agrícolas en San Ignacio (Misiones, Argentina). A partir de referencias a un trabajo de campo etnográfico iniciado en 2009, considero cómo su incorporación en los quehaceres de las chacras puede entenderse como experiencias formativas, es decir como parte de un proceso de adquisición progresiva de autonomía para el propio sostenimiento, donde las distinciones étnicas, genéricas, de edad y posición social definen ciertas actividades y saberes como propios de las “chicas de la colonia”. Estos conocimientos sobre el mundo son los que les permiten entender, pero también transformar imperceptiblemente y en su quehacer cotidiano, el mundo que las rodea
Risk perception of occupational hazards among dental health care workers in a dental hospital in Turkey
No full textIntroduction: dental caries is among the oral diseases of greatest health importance due to its magnitude, therefore knowledge about it is a determining factor in its prevention.Objective: to evaluate the effectiveness of an educational intervention concerning knowledge of dental caries in sixth grade schoolchildren.Method: a non-observational, quasi-experimental, before-after study was carried out without a control group, at Ignacio Agramonte y Loynaz Elementary School in Morón municipality in sixth grade schoolchildren, during the period from December to January 2020-2021. A sample of 30 patients was chosen by simple random sampling.Results: there was a predominance of female sex (56,7 %); 50 % of the students were 10 years old. A significant increase was observed (p˂0,01) after the intervention was applied, from the level of adequate knowledge regarding the risk factors for dental caries (26,7 % vs. 96,7 %), preventive measures (13,3 % vs. 96,7 %) and the lifestyles favoring the onset of caries (20 % vs. 100 %).Conclusions: the application of the educational intervention increased the level of knowledge concerning dental caries, which favors a better perception of risk factors and provides tools for its prevention, diagnosis and treatment.Introducción: la caries dental se encuentra entre las enfermedades bucales de mayor importancia sanitaria por su magnitud, por lo que el conocimiento sobre esta es determinante en su prevención.Objetivo: evaluar la efectividad de una intervención educativa sobre conocimiento de caries dental en escolares de sexto grado.Método: se realizó un estudio no observacional, cuasi-experimental, antes-después sin grupo control, en escolares de sexto grado de la escuela primaria Ignacio Agramonte y Loynaz del municipio Morón, durante el periodo de diciembre a enero del 2020 y 2021. Mediante muestreo aleatorio simple se seleccionó una muestra de 30 pacientes.Resultados: Existió un predominio del sexo femenino (56,7 %); el 50 % de los estudiantes poseían 10 años. Se observó un aumento significativo (p˂0,01) luego de aplicada la intervención, del nivel de conocimiento adecuado sobre los factores de riesgo de caries dental (26,7 % vs 96,7 %), las medidas de prevención (13,3 % vs 96,7 %) y los estilos de vida que favorecen la aparición de estas (20 % vs 100 %).Conclusiones: la aplicación de la intervención educativa elevó el nivel de conocimiento sobre caries dental, lo cual favorece una mejor percepción del riesgo y brinda herramientas para su prevención, diagnóstico y tratamiento
Chicas de la colonia: aprender y trabajar en la infancia rural
No full textEn este trabajo analizo, a partir de posiciones regulacionistas respecto del trabajo infantil, lasparticipaciones de las niñas en las actividades agrícolas en San Ignacio (Misiones, Argentina).A partir de referencias a un trabajo de campo etnográico iniciado en 2009, considero cómosu incorporación en los quehaceres de las chacras puede entenderse como experienciasformativas, es decir como parte de un proceso de adquisición progresiva de autonomía para elpropio sostenimiento, donde las distinciones étnicas, genéricas, de edad y posición social deinenciertas actividades y saberes como propios de las chicas de la colonia. Estos conocimientos sobre el mundo son los que les permiten entender, pero también transformar imperceptiblemente y en su quehacer cotidiano, el mundo que las rodea.Palabras clave: identiicaciones, infancia, genero, aprendizaje, agricultura familia
Functional interplay between c‐Myc and Max in B lymphocyte differentiation
No full textThe Myc family of oncogenic transcription factors regulates myriad cellular functions. Myc proteins contain a basic region/helix-loop-helix/leucine zipper domain that mediates DNA binding and heterodimerization with its partner Max. Among the Myc proteins, c-Myc is the most widely expressed and relevant in primary B lymphocytes. There is evidence suggesting that c-Myc can perform some of its functions in the absence of Max in different cellular contexts. However, the functional in vivo interplay between c-Myc and Max during B lymphocyte differentiation is not well understood. Using in vivo and ex vivo models, we show that while c-Myc requires Max in primary B lymphocytes, several key biological processes, such as cell differentiation and DNA replication, can initially progress without the formation of c-Myc/Max heterodimers. We also describe that B lymphocytes lacking Myc, Max, or both show upregulation of signaling pathways associated with the B-cell receptor. These data suggest that c-Myc/Max heterodimers are not essential for the initiation of a subset of important biological processes in B lymphocytes, but are required for fine-tuning the initial response after activation.We thank the CNB Animal and Flow Cytometry facilities and the Transgenic CNB-CBMSO UAM/CSIC Unit for the generation of maxflox mice. Next-generation sequencing experiments were performed in the Genomics Unit of the CNIC. We thank K McCreath for editing the manuscript. This work was supported by a grant of the Spanish Ministry of Economy and Competitiveness (SAF2014-52398, AEI/FEDER, UE).S
Hypothyroidism confers tolerance to cerebral malaria
No full textThe modulation of the host’s metabolism to protect tissue from damage induces tolerance to infections increasing survival. Here, we examined the role of the thyroid hormones, key metabolic regulators, in the outcome of malaria. Hypothyroidism confers protection to experimental cerebral malaria by a disease tolerance mechanism. Hypothyroid mice display increased survival after infection with Plasmodium berghei ANKA, diminishing intracranial pressure and brain damage, without altering pathogen burden, blood-brain barrier disruption, or immune cell infiltration. This protection is reversed by treatment with a Sirtuin 1 inhibitor, while treatment of euthyroid mice with a Sirtuin 1 activator induces tolerance and reduces intracranial pressure and lethality. This indicates that thyroid hormones and Sirtuin 1 are previously unknown targets for cerebral malaria treatment, a major killer of children in endemic malaria areas.This work was funded by grants SAF2017-83289-R to S.A. and A.A., SAF2017-90604REDT to A.A. supported by the The European Regional Development Fund (FEDER) and BIO2016-77430-R to J.M.B. from the Ministerio de Economía y Competitividad; B2017/BMD-3724 to S.A. and A.A. from the Comunidad de Madrid; and CIBERONC CB/16/00228 to A.A. from the Instituto de Salud Carlos III
