Stellar Populations in Barred Galaxies

We developed an iterative technique to better characterize stellar populations and the central activity of barred galaxies using evolutionary synthesis codes and OASIS data. The case of NGC5430 is presented here. Our results are reinforcing the role played by the bar and nuclear structures for the evolution of galaxies.Comment: 2 pages, 1 figure, to be published in the proceedings of IAU Symp. 262 "Stellar Populations - Planing for the Next Decate" (Aug. 2009

Phase locking a clock oscillator to a coherent atomic ensemble

The sensitivity of an atomic interferometer increases when the phase evolution of its quantum superposition state is measured over a longer interrogation interval. In practice, a limit is set by the measurement process, which returns not the phase, but its projection in terms of population difference on two energetic levels. The phase interval over which the relation can be inverted is thus limited to the interval $[-\pi/2,\pi/2]$; going beyond it introduces an ambiguity in the read out, hence a sensitivity loss. Here, we extend the unambiguous interval to probe the phase evolution of an atomic ensemble using coherence preserving measurements and phase corrections, and demonstrate the phase lock of the clock oscillator to an atomic superposition state. We propose a protocol based on the phase lock to improve atomic clocks under local oscillator noise, and foresee the application to other atomic interferometers such as inertial sensors.Comment: 9 pages, 7 figure

Nanopartículas Poliméricas en Dermocosmética

Indexación: Web of Science; Scielo.Recent advances in the fields of biomaterials and nanotechnology have allowed the development of advanced nanoparticles for biomedical applications. Despite a vast number of nanostructures such as liposomes, solid­lipid nanocapsules, polymeric and hybrid lipid­polymer nanoparticles have been studied as carriers for drug delivery for different pathologies with remarkable promising results; the use of polymeric nanoparticles in dermocosmetic still has not been widely explored. The evolution of cosmetic into the care skin and dermatology represents novel technological challenges. Also, the increasing knowledge about normal skin physiology and advances in nanotechnology provide an attractive environment for the creation of innovative dermocosmetic formulations. In this work, we discuss the state of the art of polymeric nanoparticles formulated for dermocosmetics, its mechanisms of action, and diffusion into the skin.Los recientes avances en el campo de los biomateriales y la nanotecnología han permitido el desarrollo de nanopartículas avanzadas para aplicaciones biomédicas. A pesar de que un gran número de nanoestructuras tales como liposomas, nanocápsulas lípido-sólidas, nanopartículas poliméricas y lípido-polímero híbridas han sido estudiadas como vehículos para la administración de fármacos en diferentes patologías con notables resultados prometedores, el uso de nanopartículas poliméricas en dermocosmética todavía no ha sido ampliamente explorado. La evolución de la cosmética en el cuidado de la piel y la dermatología nos enfrentan a nuevos retos tecnológicos. Además, el aumento de los conocimientos sobre la fisiología de la piel normal y los avances en la nanotecnología proporcionan un entorno atractivo para la creación de formulaciones dermocosméticas innovadoras. En este trabajo se discute el estado del arte de las nanopartículas poliméricas desarrolladas para dermocosmética, sus mecanismos de acción y la difusión en la piel.http://ref.scielo.org/b68hz

Modelling coral calcification accounting for the impacts of coral bleaching and ocean acidification

© Author(s) 2015. Coral reefs are diverse ecosystems that are threatened by rising CO2 levels through increases in sea surface temperature and ocean acidification. Here we present a new unified model that links changes in temperature and carbonate chemistry to coral health. Changes in coral health and population are explicitly modelled by linking rates of growth, recovery and calcification to rates of bleaching and temperature-stress-induced mortality. The model is underpinned by four key principles: the Arrhenius equation, thermal specialisation, correlated up- and down-regulation of traits that are consistent with resource allocation trade-offs, and adaption to local environments. These general relationships allow this model to be constructed from a range of experimental and observational data. The performance of the model is assessed against independent data to demonstrate how it can capture the observed response of corals to stress. We also provide new insights into the factors that determine calcification rates and provide a framework based on well-known biological principles to help understand the observed global distribution of calcification rates. Our results suggest that, despite the implicit complexity of the coral reef environment, a simple model based on temperature, carbonate chemistry and different species can give insights into how corals respond to changes in temperature and ocean acidification

Sex Determination by Observation of Barr Body in Teeth Subjected to High Temperatures

Galdames, IS (reprint author), Univ Talca, Ave Lircay S-N Oficina 104, Valparaiso, Chile.Sex determination is one of the keys in the identification process. A useful histological method for sex determination is the observation of Barr chromatin or Barr body. This study determines the effect of high temperatures on the diagnostic performance of the Barr chromatin observation on teeth. Were used 50 healthy teeth from 25 male and 25 female individuals aged between 14 and 44 years. The teeth were divided into 5 groups (each group with 5 female and 5 male teeth) and were exposed to controlled temperatures of 200, 400, 600, 800, and 1000 degrees C for 5 minutes. The coronal pulp was obtained and the tissue was processed and stained with hematoxylin-eosin. Four histological slides of male and 4 of female individuals were randomly selected, for each temperature level, which were observed by conventional microscopy at 100X magnification, each showing 50 cells per plate. The presence of 1 cell with visible sex chromatin was considered positive for females. It was only possible to evaluate the samples from groups subjected to 200 and 400 degrees C. In the groups analyzed, the test showed 100% accuracy. The average number of cells found to be positive Barr chromatin was 15 (SD 3.9) at 200 degrees C and 11 (SD 2.8) at 400 degrees C. Hence, it was possible to detect the sex at these temperatures by observing chromatin of the Barr body in dental pulp

Joint Optical Flow and Temporally Consistent Semantic Segmentation

The importance and demands of visual scene understanding have been steadily increasing along with the active development of autonomous systems. Consequently, there has been a large amount of research dedicated to semantic segmentation and dense motion estimation. In this paper, we propose a method for jointly estimating optical flow and temporally consistent semantic segmentation, which closely connects these two problem domains and leverages each other. Semantic segmentation provides information on plausible physical motion to its associated pixels, and accurate pixel-level temporal correspondences enhance the accuracy of semantic segmentation in the temporal domain. We demonstrate the benefits of our approach on the KITTI benchmark, where we observe performance gains for flow and segmentation. We achieve state-of-the-art optical flow results, and outperform all published algorithms by a large margin on challenging, but crucial dynamic objects.Comment: 14 pages, Accepted for CVRSUAD workshop at ECCV 201

Bayesian Joint Detection-Estimation of cerebral vasoreactivity from ASL fMRI data

International audienceAlthough the study of cerebral vasoreactivity using fMRI is mainly conducted through the BOLD fMRI modality, owing to its relatively high signal-to-noise ratio (SNR), ASL fMRI provides a more interpretable measure of cerebral vasoreactivity than BOLD fMRI. Still, ASL suffers from a low SNR and is hampered by a large amount of physiological noise. The current contribution aims at improving the re- covery of the vasoreactive component from the ASL signal. To this end, a Bayesian hierarchical model is proposed, enabling the recovery of per- fusion levels as well as fitting their dynamics. On a single-subject ASL real data set involving perfusion changes induced by hypercapnia, the approach is compared with a classical GLM-based analysis. A better goodness-of-fit is achieved, especially in the transitions between baseline and hypercapnia periods. Also, perfusion levels are recovered with higher sensitivity and show a better contrast between gray- and white matter

Development of a Global Fire Weather Database

The Canadian Forest Fire Weather Index (FWI) System is the mostly widely used fire danger rating system in the world. We have developed a global database of daily FWI System calculations, beginning in 1980, called the Global Fire WEather Database (GFWED) gridded to a spatial resolution of 0.5° latitude by 2/3° longitude. Input weather data were obtained from the NASA Modern Era Retrospective-Analysis for Research and Applications (MERRA), and two different estimates of daily precipitation from rain gauges over land. FWI System Drought Code calculations from the gridded data sets were compared to calculations from individual weather station data for a representative set of 48 stations in North, Central and South America, Europe, Russia, Southeast Asia and Australia. Agreement between gridded calculations and the station-based calculations tended to be most different at low latitudes for strictly MERRA-based calculations. Strong biases could be seen in either direction: MERRA DC over the Mato Grosso in Brazil reached unrealistically high values exceeding DC = 1500 during the dry season but was too low over Southeast Asia during the dry season. These biases are consistent with those previously identified in MERRA's precipitation, and they reinforce the need to consider alternative sources of precipitation data. GFWED can be used for analyzing historical relationships between fire weather and fire activity at continental and global scales, in identifying large-scale atmosphere–ocean controls on fire weather, and calibration of FWI-based fire prediction models.JRC.H.3 - Forest Resources and Climat