1,573 research outputs found
CYSP: A new cylindrical directional neutron spectrometer: conceptual design
This communication describes in detail the design of a new cylindrical neutron spectrometer (CYSP) embedding 7 active thermal neutron detectors in a moderating structure made of polyethylene, borated plastic and lead. The device provides a strong directional response within the energy interval from thermal to hundreds of MeV, being nearly insensitive to neutrons coming from directions other than the cylinder axis with energies up to about 10 MeV. Therefore it will be especially suitable for applications where the neutron spectrum as a function of the emission angle needs to be measured. The Monte Carlo transport code MCNPX has been used to reach the final configuration for the spectrometer in terms of size, collimator, and arrangement of borated plastic and lead layers, number and position of the detectors. Moreover, MCNPX has been also used to calculate the response matrix of the instrument
Transdisciplinary integration and its implementation in primary education through two STEAM projects
Número especial: Educación STEAM: aportando pruebas de validez y efectividadSpecial issue: STEAM Education: contributing evidence of validity and effectivenessLa integración curricular desde una perspectiva STEAM transdisciplinar representa un profundo desafío. Este estudio profundiza en una comprensión transdisciplinar de la Educación Primaria y el rol del arte en dos proyectos STEAM a través del concepto de gran idea. Han participado 111 estudiantes de ocho grupos (11-12 años) de un programa para alumnado con altas capacidades, junto con cinco profesores y cuatro profesionales externos. Desde el rol de profesores e investigadores, se ha empleado la observación participante y no participante, grabaciones de vídeo, entrevistas individuales y grupales, diarios de clase y cuestionarios, triangulados y codificados a través de la Teoría de la Actividad mediante el software Atlas.ti8 y el análisis estadístico. Los resultados evidencian la significatividad del aprendizaje y la construcción de experiencias significativas, relacionadas con un grado elevado de motivación y de satisfacción, así como a la integración de diversas áreas en un proceso participativo, en el que el arte ha jugado un rol disciplinar e integrador. Se presenta una aproximación STEAM Transdisciplinar que podría resultar paradigmática para el ámbito de la Educción Primaria.Curriculum integration from a STEAM transdisciplinary perspective represents a profound challenge. This study delves into a transdisciplinary approach to primary education and the role of the arts through two STEAM projects in a programme for gifted students in Madrid (Spain). Participants include 111 students from eight groups (11–12 years old), five teachers and four external professionals. The teachers fulfill the dual role of both teacher and researcher, using participant and non-participant observation, video recordings, interviews and classroom journals and questionnaires. All the findings have been triangulated and coded by means of Activity Theory, using Atlas.ti8 software and statistical analysis. The results show the significance of learning and the creation of meaningful experiences as being related to a high degree of motivation and satisfaction, and to the integration of diverse areas in a participatory process in which the arts play a disciplinary and integrating role. A transdisciplinary STEAM approach is presented that could be paradigmatic for the field of primary education
Joint coarse-and-fine reasoning for deep optical flow
© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We propose a novel representation for dense pixel-wise estimation tasks using CNNs that boosts accuracy and reduces training time, by explicitly exploiting joint coarse-and-fine reasoning. The coarse reasoning is performed over a discrete classification space to obtain a general rough solution, while the fine details of the solution are obtained over a continuous regression space. In our approach both components are jointly estimated, which proved to be beneficial for improving estimation accuracy. Additionally, we propose a new network architecture, which combines coarse and fine components by treating the fine estimation as a refinement built on top of the coarse solution, and therefore adding details to the general prediction. We apply our approach to the challenging problem of optical flow estimation and empirically validate it against state-of-the-art CNN-based solutions trained from scratch and tested on large optical flow datasets.Peer ReviewedPostprint (author's final draft
Ictiólogos de la Argentina: Alberto Nani.
En esta serie se mencionan a todos aquellos que, a través de sus pequeños o grandes aportes, contribuyeron a la consolidación de la disciplina en nuestro país.
El plan general de esta contribución consiste en la elaboración de fichas individuales que contengan una lista de trabajos de los diferentes autores, acompañadas por bibliografía de referencia y, cuando ello fuera posible, por imágenes personales y material adicional.
Se tratará de guardar un orden cronológico, pero esto no es excluyente, ya que priorizaremos las sucesivas ediciones al material disponible.
Este es otro camino para rescatar y revalorizar a quienes en diversos contextos históricos sentaron las bases de lo que hoy es la ictiología nacional.
Considero que este es el comienzo de una obra de mayor magnitud en la que se logre describir una parte importante de la historia de las ciencias naturales de la República Argentina
On the nature of an ejection event in the jet of 3C111
We present a possible scenario for the ejection of a superluminal component
in the jet of the Broad Line Radio Galaxy 3C111 in early 1996. VLBI
observations at 15 GHz discovered the presence of two jet features on scales
smaller than one parsec. The first component evolves downstream, whereas the
second one fades out after 1 parsec. We propose the injection of a perturbation
of dense material followed by a decrease in the injection rate of material in
the jet as a plausible explanation. This scenario is supported by 1D
relativistic hydrodynamics and emission simulations. The perturbation is
modeled as an increase in the jet density, without modifying the original
Lorentz factor in the initial conditions. We show that an increase of the
Lorentz factor in the material of the perturbation fails to reproduce the
observed evolution of this flare. We are able to estimate the lifetime of the
ejection event in 3C111 to be 36\pm7 days.Comment: Accepted for publication in Astronomy & Astrophysics Letter
Symptoms and etiological attribution: a cross-sectional study in mexican outpatients with psychosis and their relatives
This cross-sectional study aimed at identifying the most common attributions of their mental disorder in a Mexican patients who have experienced psychosis and their relatives and exploring how having experienced or not characteristic psychotic symptoms and their present clinical status might affect their etiological attributions. Past and current symptom profiles of 66 patients were as assessed with the SCID-I (Structured Clinical Interview for DSM-IV Axis I Disorders) and the PANSS (Positive and Negative Syndrome Scale), respectively. The etiological attribution of psychosis of patients () and the relatives () was assessed with the Angermeyer and Klusmann scale comprising 30 items into five categories: biology, personality, family, society, and esoteric. Patients and relatives attribute psychosis mainly to social factors. Relatives' attributions were not influenced by clinical profile of patients, whereas in the case of patients it was only current clinical status that showed a difference, with those in nonremission scoring higher personality and family factors. Acknowledging patients' and relatives' beliefs about mental disorders at onset and later on is particularly important in psychosis, a mental condition with severe and/or persistent symptoms, in order to promote better involvement in treatment and in consequence efficacy and recovery
7-Nitroindazole down-regulates dopamine/DARPP-32 signaling in neostriatal neurons in a rat model of Parkinson's disease
Neuronal nitric oxide synthase (nNOS) is involved in the regulation of diverse intracellular messenger systems in the brain. Nitric Oxide (NO) contributes to inducing signaling cascades that involve a complex pattern of phosphorylation of DARPP-32 (in Thr-34), which controls the phosphoproteins involved in neuronal activation. However, the role of NO in the pathophysiology of Parkinson's disease (PD) and its effect in striatal neurons have been scarcely explored. In the present work, we investigate the effects of a nitric oxide synthase (NOS) inhibitor, 7-nitroindazole (7-NI) in the nigrostriatal pathway of striatal 6-hydroxydopamine (6-OHDA) lesioned rats. Our quantitative histological findings show that treatment with 7-NI significantly reduced 6-OHDA-induced dopaminergic damage in the dorsolateral striatum and Substantia Nigra pars compacta (SNpc). Moreover, 6-OHDA lesioned rats show a significant increase of nNOS+ and Phospho-Thr34-DARPP-32+ cells, accompanied by a consequent decrease of total DARPP-32+ cells, which suggests an imbalance of NO activity in the DA-depleted striatum, which is also reflected in behavioral studies. Importantly, these effects are reverted in the group treated with 7-NI. These results show a clear link between the state of phosphorylation of DARPP-32 and parkinsonism, which is regulated by nNOS. This new evidence suggests a prominent role for nitric oxide in the neurotransmitter balance within the basal ganglia in the pathophysiology of experimental parkinsonism.This work was supported by grants from the Spanish Ministry of Science (SAF 2007-62262), FIS (PI/2010/02827) and CIBERNED (Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas)
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