2,048 research outputs found
Low-Mass Eclipsing Binaries in the Initial Kepler Data Release
We identify 231 objects in the newly released Cycle 0 dataset from the Kepler
Mission as double-eclipse, detached eclipsing binary systems with Teff < 5500 K
and orbital periods shorter than ~32 days. We model each light curve using the
JKTEBOP code with a genetic algorithm to obtain precise values for each system.
We identify 95 new systems with both components below 1.0 M_sun and eclipses of
at least 0.1 magnitudes, suitable for ground-based follow-up. Of these, 14 have
periods less than 1.0 day, 52 have periods between 1.0 and 10.0 days, and 29
have periods greater than 10.0 days. This new sample of main-sequence,
low-mass, double-eclipse, detached eclipsing binary candidates more than
doubles the number of previously known systems, and extends the sample into the
completely heretofore unexplored P > 10.0 day period regime. We find
preliminary evidence from these systems that the radii of low-mass stars in
binary systems decrease with period. This supports the theory that binary
spin-up is the primary cause of inflated radii in low-mass binary systems,
although a full analysis of each system with radial-velocity and multi-color
light curves is needed to fully explore this hypothesis. As well, we present 7
new transiting planet candidates that do not appear among the recently released
list of 706 candidates by the Kepler team, nor in the Kepler False Positive
Catalog, along with several other new and interesting systems. We also present
novel techniques for the identification, period analysis, and modeling of
eclipsing binaries.Comment: 22 pages in emulateapj format. 9 figures, 4 tables, 2 appendices.
Accepted to AJ. Includes a significant addition of new material since last
arXiv submission and an updated method for estimating masses and radi
Semi-automatic detection of hepatic tumor in computed tomography images
In this work, the main purpose is develop a computational segmentation strategy for
liver tumor semiautomatic detection. This strategy considers three-dimensional computed
tomography images and it consists of techniques application that, on the one hand, diminish the
noise and detect the edges of the objects present in those images and, on the other hand, generate
the liver tumor morphology. For this, the sequence of techniques composed of gaussian
smoothing, gradient magnitude, median filter, region growing and binary morphological dilation
are used. The value obtained, for the metric called Dice score, show a good correlation between
manual segmentation, performed by a hepatologist, and the tumor segmentation obtained using
the proposed technique. This type of segmentation is the extreme utility for the characterization
of hepatic tumors and the planning of the clinical behavior to be followed in the treatment of this
human liver disease
Simulation Study of Chic -> J/Psi + gamma Detection with J/Psi -> e+ e- in pp Collisions
We present Monte Carlo preliminary results about the feasibility to detect
the Chic family in p-p collisions at 14 TeV in the ALICE Central Barrel at CERN
LHC. The Chic1 and Chic2 were forced to decay in the channel J/Psi + gamma ->
e+ e- + gamma and were merged with a proton-proton non-biased collision. After
MonteCarlo transport and simulation of the detector response, the e+, e- and
converted gamma were reconstructed and identified in the ALICE ITS, TPC and TRD
detectors. Separate signals corresponding to gamma from Chic1 and from Chic2
were observed. The position and relative weight of the fit to gaussians agreed
with the input values within the statistical limits. Similar studies will be
done for Pb-Pb collisions
ESTADO DEL ARTE DE IPTV Y CONSIDERACIONES TÉCNICAS PARA SU MIGRACIÓN A IPV6 EN COLOMBIA
El artículo tiene como objetivos centrales hacer una revisión del estado del arte de IPTV (Televisión a través de IP) y una propuesta para la implementación de esta tecnología en Colombia sobre una red IPv6. La convergencia de las teleco-municaciones ha dado origen a aplicaciones IP que permiten acceso a contenidos audiovisuales digitalizados a través de re-des que hacen uso de dicho protocolo. Se abordanestudios ac-tuales que tratan características fundamentales de televisión sobre la red de datos, como el funcionamiento, la arquitectura, los estándares en los que se basa, propuestas para evaluar las políticas de calidad de servicio y por ultimo consideraciones técnicas para su implementación en una red IPv6
Strategies against β-amyloid protein as therapeutics in Alzheimer's disease
Podeu consultar el llibre complet a: http://hdl.handle.net/2445/12071
Evaluation of polymeric nanofiltration membranes on metal valorisation from acidic mine waters
Postprint (author's final draft
Benzodiazepines and Related Drugs as a Risk Factor in Alzheimer's Disease Dementia.
Benzodiazepines (BZDs) and Z-drugs are compounds widely prescribed in medical practice due to their anxiolytic, hypnotic, and muscle relaxant properties. Yet, their chronic use is associated with cases of abuse, dependence, and relapse in many patients. Furthermore, elderly people are susceptible to alterations in pharmacodynamics, pharmacokinetics as well as to drug interaction due to polypharmacy. These situations increase the risk for the appearance of cognitive affectations and the development of pathologies like Alzheimer's disease (AD). In the present work, there is a summary of some clinical studies that have evaluated the effect of BZDs and Z-drugs in the adult population with and without AD, focusing on the relationship between their use and the loss of cognitive function. Additionally, there is an assessment of preclinical studies focused on finding molecular proof on the pathways by which these drugs could be involved in AD pathogenesis. Moreover, available data (1990-2019) on BZD and Z-drug use among elderly patients, with and without AD, was compiled in this work. Finally, the relationship between the use of BZD and Z-drugs for the treatment of insomnia and the appearance of AD biomarkers was analyzed. Results pointed to a vicious circle that would worsen the condition of patients over time. Likewise, it put into relevance the need for close monitoring of those patients using BZDs that also suffer from AD. Consequently, future studies should focus on optimizing strategies for insomnia treatment in the elderly by using other substances like melatonin agonists, which is described to have a much more significant safety profile
Optimizing CIGB-300 intralesional delivery in locally advanced cervical cancer
Background:We conducted a phase 1 trial in patients with locally advanced cervical cancer by injecting 0.5 ml of the CK2-antagonist CIGB-300 in two different sites on tumours to assess tumour uptake, safety, pharmacodynamic activity and identify the recommended dose.Methods:Fourteen patients were treated with intralesional injections containing 35 or 70 mg of CIGB-300 in three alternate cycles of three consecutive days each before standard chemoradiotherapy. Tumour uptake was determined using 99 Tc-radiolabelled peptide. In situ B23/nucleophosmin was determined by immunohistochemistry.Results:Maximum tumour uptake for CIGB-300 70-mg dose was significantly higher than the one observed for 35 mg: 16.1±8.9 vs 31.3±12.9 mg (P=0.01). Both, AUC 24h and biological half-life were also significantly higher using 70 mg of CIGB-300 (P<0.001). Unincorporated CIGB-300 diffused rapidly to blood and was mainly distributed towards kidneys, and marginally in liver, lungs, heart and spleen. There was no DLT and moderate allergic-like reactions were the most common systemic side effect with strong correlation between unincorporated CIGB-300 and histamine levels in blood. CIGB-300, 70 mg, downregulated B23/nucleophosmin (P=0.03) in tumour specimens.Conclusion:Intralesional injections of 70 mg CIGB-300 in two sites (0.5 ml per injection) and this treatment plan are recommended to be evaluated in phase 2 studies.Fil: Sarduy, M. R.. Medical-surgical Research Center; CubaFil: García, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Coca, M. A.. Clinical Investigation Center; CubaFil: Perera, A.. Clinical Investigation Center; CubaFil: Torres, L. A.. Clinical Investigation Center; CubaFil: Valenzuela, C. M.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Baladrón, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Solares, M.. Hospital Materno Ramón González Coro; CubaFil: Reyes, V.. Center For Genetic Engineering And Biotechnology Havana; CubaFil: Hernández, I.. Isotope Center; CubaFil: Perera, Y.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Martínez, Y. M.. Medical-surgical Research Center; CubaFil: Molina, L.. Medical-surgical Research Center; CubaFil: González, Y. M.. Medical-surgical Research Center; CubaFil: Ancízar, J. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Prats, A.. Clinical Investigation Center; CubaFil: González, L.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Casacó, C. A.. Clinical Investigation Center; CubaFil: Acevedo, B. E.. Centro de Ingeniería Genética y Biotecnología; CubaFil: López Saura, P. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes; ArgentinaFil: Gómez, R.. Elea Laboratories; ArgentinaFil: Perea Rodríguez, S. E.. Center For Genetic Engineering And Biotechnology Havana; Cuba. Centro de Ingeniería Genética y Biotecnología; Cub
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