3,128 research outputs found
HIV-1 and Alzheimer: a real conection?
La infección por el virus de inmunodeficiencia humana (VIH) causa alteraciones neurológicas que son más graves y frecuentes como consecuenia del envejecimieno de la población. Este daño se asocia a la disfunción neuronal, que patológicamente se caracteriza como una pérdida de sinapsis, acortamiento de neuritas, anormalidades dendríticas, así comon pérdida neuronal. A este respecto, varios estudios han observado un aumento significativo de placas amiloides en cerebros de individuos infectados por el VIH en comparación con controles sanos, así como en individuos VIH positivos que habían estado expuestos a la terapia antirretroviral. En este trabajo se ha investigado el efecto de la combinación del péptido β-amiloide e infección por VIH-1 en diferentes células del sistema nervioso. El pretratamiento de las células gliales y neuronales provoca un incremento en la replicación viral, así como el tratamiento combinado virus y formas de oligómeros y fibrillas producen un incremento en las especies reactivas de oxígeno y de la forma activa de la enzima proapoptótica caspasa-3, en astrocitos. Lo que podría traducirse como un incremento de neurotoxicidad y depositos de β-amiloide en el cerebro infectado.Infection by human immunodeficiency virus (HIV) promotes neurological alterations which are more severe and frequents, due to the aging of the population. This dementia is associated to neuronal disfunction, and is pathologicaly characterized as sinapse lose, dendritic abnormalities and neuronal death. Supporting this, several studies have shown a significant increase of the amyloid plaques in infected HIV brains compared to healthy controls as well as HIV positive individuals which were exposed to antiretroviral therapy. In the present study we have investigated the combined effect of amyloid-β and HIV-1 infection in diferent nervous cells. When we pretreated glial cells and neurons we found an increased viral replication, as well as the combined treatment of HIV and oligomeric and fibrils forms of amyloid-β which produce glial increased levels of oxygen reactive species and the proapoptotic enzyme caspase-3. These observations could be traduced in an increased neurotoxicity and amyloid-β deposits in infected brains
Sicole: diagnóstico y tratamiento computarizado de la dislexia en español
En este articulo realizamos un recorrido sobre las investigaciones más relevantes en el campo
de la tecnología aplicada al diseño instruccional, las cuales marcan las pautas de diseño
de los programas educativos actuales y presentamos los criterios pedagógicos y tecnológicos que hemos seguido en el diseño e implementación de un ITS para la diagnóstico, evaluación y
tratamiento de niños con Dislexia en el lenguaje español. Este trabajo se halla dentro del
marco de un proyecto de investigación interdisciplinar titulado SICOLE, formado por psicólogos,
pedagogos e informáticos.In this paper we present the most significant researchers in the area of technology applied to
instructional design. Also, we describe the pedagogical and technological principles followed
in the design and implementation of an Intelligent Tutorial System for assessment and treatment of dyslexic children in Spanish language. This work is result of a multidisciplinary research
with engineers, teachers and psychologists and it has been funded by «Fondos Europeos para
el Desarrollo Regional» (FEDER), 1FD97-1140, and the «Dirección General de Investigación
Científica y Técnica» (DIGICYT). This package has being used in several Spanish schools as part of its validation process
Fijación interna versus percutánea en fracturas diafisarias de metacarpianos: estudio de casos-controles
Objetivos: comparación de resultados clínicos de fijación interna versus fijación percutánea. Material
y Métodos: estudio retrospectivo de casos y controles de 58 fracturas de metacarpianos (43 pacientes). Se incluyeron
las fracturas diafisarias, sin afectación articular. Se excluyeron si había afectación del pulgar o de falanges, fracturas
abiertas o más de 3 fracturas en la misma mano. Un total de 26 fracturas fueron tratadas con fijación interna y
32 con percutánea. Con un seguimiento medio de 2,5 años (rango, 1-4), se valoró la función mediante movilidad activa
total (MAT), fuerza, DASH, EAV de dolor y resultado radiográfico. Resultados: con ambos tratamientos los resultados
fueron satisfactorios. El tiempo de consolidación y alineación radiográfica fueron similares. Todas las valoraciones
clínicas, objetivas y subjetivas, fueron mejores en el grupo de fijación interna, así como la tasa de retorno a
las actividades previas. En el grupo de fijación interna hubo un caso de pseudoartrosis que fue reoperado y otro de
déficit de movilidad. En el grupo percutáneo hubo 4 casos con déficit de movilidad. Discusión y conclusiones: ambas
técnicas ofrecen resultados adecuados, pero con la fijación interna se obtuvieron mejores resultados respecto a movilidad,
fuerza, mayor facilidad para realización de las actividades previas y retorno a las laborales y deportivas, a pesar
de las complicaciones inherentes a la cirugía abiertaObjectives: comparison of outcomes with internal fixation versus percutaneous fixation. Material
and Methods: retrospective case-control study of 58 metacarpal fractures (43 patients). Shaft fractures without joint
involvement were included. Exclusion criteria were involvement of the thumb or phalange, open fracture, or more
than 3 fractures in the same hand. There were 26 fractures treated with internal fixation and 32 with percutaneous
fixation. With a mean follow-up of 2,5 years (range, 1-4), functional evaluation was performed by total active motion
(TAM), strength grip, DASH, pain VAS, and radiographic results. Results: satisfactory outcomes were obtained with
both treatments. Consolidation time and radiographic alignment were similar. All clinical objective and subjective
assessments were better in the internal fixation group, as well as the rate of return to previous activities. In the internal
fixation group, there was one case with nonunion, which was reoperated, and other with lack of motion. In the
percutaneous group, there were 4 cases with mobility deficits. Discussion and conclusions: satisfactory results were
offered by both methods, but better outcomes were obtained by internal fixation with regard to motion, strength, best
facility for previous activities, and return to work and sport activities. All this was spite of the inherent complications of open surger
Validation of the IOLF5C instrument for the efficacy of shooting on goal in football for the blind
El objetivo del estudio es diseñar y validar un instrumento de observación
para conocer los Indicadores de Rendimiento Competitivo en Fútbol a 5 para
personas ciegas a través de jueces expertos. La muestra se compuso por 12
entrenadores expertos en Fútbol a 5. Tras la realización de un estudio preliminar,
el IOLF5C quedó estructurado en dos partes: acciones básicas durante el
lanzamiento a portería en situaciones de juego, y durante el penalti. La validez
de contenido se realizó a través de la V de Aiken y sus intervalos de confianza.
Para comprobar la consistencia interna del instrumento se empleó α de
Cronbach. Los resultados indicaron que el IOLF5C dispone de niveles óptimos
de validez obteniendo valores superiores a 0,875 en todos los ítems durante el
juego y 0,96 en penalti. La consistencia del instrumento fue de 0,894. Por tanto, el IOLF5C es un instrumento válido y fiableThe aim of this study was to design and validate an observational instrument to
identify essential competitive performance indicators in Football 5-a-Side for
blind and partially sighted players through the assistance of expert evaluators.
The sample was comprised of twelve Football 5-a-Side expert coaches. After a
preliminary study, the OLF5C instrument was structured to include two groups
of actions: basic actions during shots on goal in game situations and shooting
actions penalty situations. Aiken's V statistic and confidence interval values
were used to assess the content validity and Cronbach' value was used to
assess the internal consistency of the instrument. Results indicated that the
IOLF5C has good validity indices with obtained values reaching .875 in all items
during game situations and 0.96 on penalty shot actions. The overall level of
instrument consistency was .894. The IOLF5C is considered to be a valid and reliable instrumen
Osteoblastoma del sacro. A propósito de dos casos clínicos.
El osteoblastoma es un tumor óseo primitivo de frecuente localización en los elementos posteriores de la columna vertebral, aunque raro en el sacro. Se presentan dos osteoblastomas del sacro, con un seguimiento medio de ocho años, tratados mediante resección intralesional que, sin morbilidad, deparó un excelente resultado. El curetaje sería un procedimiento de resección válido en osteoblastomas sacros no agresivos, si bien obliga a un seguimiento prolongado del paciente para vigilar la posibilidad de recidivas locales.Osteoblastoma is a primary neoplasm of bone fre-
quently located in the posterior elements of the spine, alt-
hough rarely affecting the sacrum. Two cases in this location
are reported, with a mean follow-up of eight years, treated
with an intralesional resection that, without any morbidity, has
provided an excellent result. Curettage should be a valid re-
section procedure for nonagressive osteoblastomas of the
sacrum, although it makes necessary a long follow-up in or-
der to watch over the possibility of a local recurrence
Emitters of -photon bundles
We propose a scheme based on the coherent excitation of a two-level system in
a cavity to generate an ultrabright CW and focused source of quantum light that
comes in groups (bundles) of photons, for an integer tunable with the
frequency of the exciting laser. We define a new quantity, the \emph{purity} of
-photon emission, to describe the percentage of photons emitted in bundles,
thus bypassing the limitations of Glauber correlation functions. We focus on
the case and show that close to 100% of two-photon emission and
90% of three-photon emission is within reach of state of the art cavity QED
samples. The statistics of the bundles emission shows that various
regimes---from -photon lasing to -photon guns---can be realized. This is
evidenced through generalized correlation functions that extend the standard
definitions to the multi-photon level.Comment: Introduce the n-th order N-photon correlation functions. Reorganized
to emphasize the N-photon emitter, now extended to the antibunching regime,
rather than only coherent emission as previsoul
Health Promotion for Childhood Obesity: An Approach Based on Self-Tracking of Data
[EN]At present, obesity and overweight are a global health epidemic. Traditional interventions
for promoting healthy habits do not appear to be e ective. However, emerging technological solutions
based on wearables and mobile devices can be useful in promoting healthy habits. These applications
generate a considerable amount of tracked activity data. Consequently, our approach is based on
the quantified-self model for recommending healthy activities. Gamification can also be used as
a mechanism to enhance personalization, increasing user motivation. This paper describes the
quantified-self model and its data sources, the activity recommender system, and the PROVITAO
App user experience model. Furthermore, it presents the results of a gamified program applied for
three years in children with obesity and the process of evaluating the quantified-self model with
experts. Positive outcomes were obtained in children’s medical parameters and health habits
Valence change of praseodymium in Pr0.5Ca0.5CoO3 investigated by x-ray absorption spectroscopy
X-ray absorption spectroscopy measurements in Pr0.5Ca0.5CoO3 were performed
at the Pr M4,5, Pr L3, and Ca L2,3 absorption edges as a function of
temperature below 300 K. Ca spectra show no changes down to 10 K while a
noticeable thermally dependent evolution takes place at the Pr edges across the
metal-insulator transition. Spectral changes are analyzed by different methods,
including multiple scattering simulations, which provide quantitative details
on an electron loss at Pr 4f orbitals. We conclude that in the insulating phase
a fraction [15(+5)%] of Pr3+ undergoes a further oxidation to adopt a
hybridized configuration composed of an admixture of atomic-like 4f1 states
(Pr4+) and f- symmetry states on the O 2p valence band (Pr3+L states)
indicative of a strong 4f- 2p interaction.Comment: 19 pages (.doc), 4 figures, Phys. Rev. B, in pres
Agile human centered methodologies to develop educational software
This paper presents a methodological proposal that is based on powerful current approaches to the software development process: agile methodologies (SCRUM, Lean UX), user-centered design (UCD) and user experience design (UXD). Specifically, we have adapted some of the characteristics of the agile methodologies, which have allowed us to produce useful prototypes that are focused on the users while receiving constant feedback from them. The main goal of the proposed methodology is to identify usability problems and UX factors in the early stages of educational software development. Furthermore, we have also applied and validated the proposal during the framework development of an educational software project for users with special educational needs. A specific case taking into account key usability issues to support students with special education needs (SEN) is presented. In conclusion, we state that the proposed methodology could be a good design process philosophy to follow in the development of software projects in general, and in educational projects in particular
The High Cadence Transit Survey (HiTS): Compilation and Characterization of Light-curve Catalogs
Indexación: Scopus.J.M. acknowledges support from CONICYT-Chile through CONICYT-PCHA/Doctorado-Nacional/2014-21140892. J.M., F.F., G.C.V., and G.M. acknowledge support from the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC120009, awarded to the Millennium Institute of Astrophysics (MAS). F.F. acknowledges support from Conicyt through the Fondecyt Initiation into Research project No. 11130228. J.M., F.F., J.S.M., G.C.V., and S.G. acknowledge support from Basal Project PFB-03, Centro de Modelamiento Matemáico (CMM), Universidad de Chile. P.L. acknowledges support by Fondecyt through project #1161184. G.C.V. gratefully acknowledges financial support from CON-ICYT-Chile through FONDECYT postdoctoral grant number 3160747 and CONICYT-Chile and NSF through the Programme of International Cooperation project DPI201400090. P.H. acknowledges support from FONDECYT through grant 1170305. L.G. was supported in part by the US National Science Foundation under grant AST-1311862. G.M. acknowledges support from Conicyt through CONICYT-PCHA/Magís-terNacional/2016-22162353. Support for T.d.J. has been provided by US NSF grant AST-1211916, the TABASGO Foundation, and Gary and Cynthia Bengier. R.R.M. acknowledges partial support from BASAL Project PFB-06, as well as FONDECYT project N◦1170364. Powered@NLHPC: this research was supported by the High Performance Computing infrastructure of the National Laboratory for High Performance Computing (NLHPC), PIA ECM-02, CONICYT. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaborating institutions: Argonne National Lab, the University of California Santa Cruz, the University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologi-cas-Madrid, the University of Chicago, University College London, the DES-Brazil consortium, the University of Edinburgh, ETH-Zurich, the University of Illinois at Urbana-Champaign, Institut de Ciencies de l’Espai, Institut de Fisica d’Altes Energies, Lawrence Berkeley National Lab, Ludwig-Maximilians Universitat, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Lab, Stanford University, the University of Sussex, and Texas A&M University. Funding for DES, including DECam, has been provided by the U.S. Department of Energy, National Science Foundation, Ministry of Education and Science (Spain), Science and Technology Facilities Council (UK), Higher Education Funding Council (England), National Center for Supercomputing Applications, Kavli Institute for Cosmological Physics, Financia-dora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo a Pesquisa, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência e Tecnologia (Brazil), the German Research Foundation-sponsored cluster of excellence “Origin and Structure of the universe,” and the DES collaborating institutions. Facility: CTIO:1.5 m (DECam).The High Cadence Transient Survey (HiTS) aims to discover and study transient objects with characteristic timescales between hours and days, such as pulsating, eclipsing, and exploding stars. This survey represents a unique laboratory to explore large etendue observations from cadences of about 0.1 days and test new computational tools for the analysis of large data. This work follows a fully data science approach, from the raw data to the analysis and classification of variable sources. We compile a catalog of ∼15 million object detections and a catalog of ∼2.5 million light curves classified by variability. The typical depth of the survey is 24.2, 24.3, 24.1, and 23.8 in the u, g, r, and i bands, respectively. We classified all point-like nonmoving sources by first extracting features from their light curves and then applying a random forest classifier. For the classification, we used a training set constructed using a combination of cross-matched catalogs, visual inspection, transfer/active learning, and data augmentation. The classification model consists of several random forest classifiers organized in a hierarchical scheme. The classifier accuracy estimated on a test set is approximately 97%. In the unlabeled data, 3485 sources were classified as variables, of which 1321 were classified as periodic. Among the periodic classes, we discovered with high confidence one δ Scuti, 39 eclipsing binaries, 48 rotational variables, and 90 RR Lyrae, and for the nonperiodic classes, we discovered one cataclysmic variable, 630 QSOs, and one supernova candidate. The first data release can be accessed in the project archive of HiTS (http://astro.cmm.uchile.cl/HiTS/). © 2018. The American Astronomical Society. All rights reserved.https://iopscience.iop.org/article/10.3847/1538-3881/aadfd
- …