5,438 research outputs found

    INSA scientific activities in the space astronomy area

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    Support to Astronomy operations is an important and long-lived activity within INSA. Probably the best known (and traditional) INSA activities are those related with real-time spacecraft operations: Ground station maintenance and operation (Ground station engineers and operators); spacecraft and payload real-time operation (spacecraft and instruments controllers); computing infrastructure maintenance (operators, analysts) and general site services.In this paper, we'll show a different perspective, probably not so well-known, presenting some INSA recent activities at the European Space Astronomy Centre (ESAC) and NASA Madrid Deep Space Communication Complex (MDSCC) directly related to scientific operations. Basic lines of activity involved include: Operations support for science operations; system and software support for real time systems; technical administration and IT support; R \& D activities, radioastronomy (at MDSCC and ESAC) and scientific research projects. This paper is structured as follows: first, INSA activities in two ESA cornerstone astrophysics missions, XMM-Newton and Herschel, will be outlined. Then, our activities related to Science infrastructure services, represented by the Virtual Observatory (VO) framework and the Science Archives development facilities are briefly shown. Radio Astronomy activities will be described afterwards, and finally, a few research topics in which INSA scientists are involved will be also described.Comment: 6 pages. Highlights of Spanish Astrophysics V Proceedings of the VIII Scientific Meeting of the Spanish AstronomicalSociety (SEA) held in Santander, 7-11 July, 200

    Compact Stars and Magnetized CFL Matter

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    The stability of the color flavor locked phase in the presence of a strong magnetic field is investigated within the phenomenological MIT bag model. It is found that the minimum value of the energy per baryon in a color flavor locked state at vanishing pressure is lower than the corresponding one for unpaired magnetized strange quark matter and, as the magnetic field increases, the energy per baryon decreases. This implies that magnetized color flavor locked matter is more stable and could become the ground state inside neutron stars. The anisotropy of the pressures is discussed. The mass-radius relation for such stars is also studied

    Search for H alpha emitters in Galaxy Clusters with Tunable Filters

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    The studies of the evolution of galaxies in Galaxy Clusters have as a traditional complication the difficulty in establishing cluster membership of those sources detected in the field of view. The determination of spectroscopic redshifts involves long exposure times when it is needed to reach the cluster peripherical regions of/or clusters at moderately large redshifts, while photometric redshifts often present uncertainties too large to offer significant conclusions. The mapping of the cluster of galaxies with narrow band tunable filters makes it possible to reach large redshifts intervals with an accuracy high enough to establish the source membership of those presenting emission/absorption lines easily identifiable, as H alpha. Moreover, the wavelength scan can include other lines as [NII], [OIII] or HβH_{\beta} allowing to distinguish those sources with strong stellar formation activity and those with an active galactic nuclei. All this makes it possible to estimate the stellar formation rate of the galaxies observed. This, together with ancillary data in other wavelengths may lead to a good estimation of the stellar formation histories. It will shed new light over the galaxy evolution in clusters and will improve our understanding of galaxy evolution, especially in the outer cluster regions, usually less studied and with significant unexploited data that can not be correctly interpreted without redshift determination.Comment: 4 pages, 2 figures. "Highlights of Spanish Astrophysics V", Proceedings of the VIII Scientific Meeting of the Spanish Astronomical Society (SEA) held in Santander, 7-11 July, 200

    Analyse des groupes de gènes co-exprimés : un outil automatique pour l'interprétation des expériences de biopuces (version étendue)

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    National audienceLa technologie des biopuces permet de mesurer les niveaux d'expression de milliers de gènes dans différentes conditions biologiques générant ainsi des masses de données à analyser. De nos jours, l'interprétation de ces volumineux jeux de donnés à la lumière des différentes sources d'informations est l'un des principaux défis dans la bio-informatique. Nous avons développé une nouvelle méthode appelée AGGC (Analyse des Groupes de Gènes Co-exprimés) qui permet de constituer de manière automatique des groupes de gènes à la fois fonctionnellement riches, i.e. qui partagent les mêmes annotations fonctionnelles, et co-exprimés. AGGC intègre l'information issue des biopuces, i.e. les profils d'expression des gènes, avec les annotations fonctionnelles des gènes obtenues à partir des sources d'informations génomiques comme Gene Ontology. Les expérimentations menées avec cette méthode ont permis de mettre en évidence les principaux groupes de gènes fonctionnellement riches et co-exprimés dans des expériences de biopuces. Programme et informations annexes : http://keia.i3s.unice.fr/?Implementations:CGGA

    Strange matter in the universe

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    The strange quark matter hypothesis is one of the most exciting speculations of the XX Century Physics. If this hypothesis is correct, the ground state of the matter would be the strange matter, which could form the core of compact objects like neutron stars or even more exotic objects like quarks stars. Due to the high-density and low-temperature regime in these stars, the interaction between quarks through gluon exchange could favor the appearance of a color superconducting state, significantl modifying the equation of state of the system. In this paper we present a general overview of this Subject, taking also into account the effect of strong magnetic field in the quark stars

    Co-expressed Gene Groups Analysis (CGGA): An Automatic Tool for the Interpretation of Microarray Experiments

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    International audienceMicroarray technology produces vast amounts of data by measuring simultaneously the expression levels of thousands of genes under hundreds of biological conditions. Nowadays, one of the principal challenges in bioinformatics is the interpretation of this large amount of data using different sources of information. We have developed a novel data analysis method named CGGA (Co-expressed Gene Groups Analysis) that automatically finds groups of genes that are functionally enriched, i.e. have the same functional annotations, and are co-expressed. CGGA automatically integrates the information of microarrays, i.e. gene expression profiles, with the functional annotations of the genes obtained by the genome-wide information sources such as Gene Ontology. By applying CGGA to well-known microarray experiments, we have identified the principal functionally enriched and co-expressed gene groups, and we have shown that this approach enhances and accelerates the interpretation of DNA microarray experiments. CGGA program is available at http://www.i3s.unice.fr/~rmartine/CGG

    Magnetic Field and Temperature Effects on Strangelets

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    The main properties of magnetized strangelets, namely, their energy per baryon, radius and electric charge, are studied in the unpaired strange quark matter phase. Temperature effects are taken into account in order to study their stability compared to the (56)Fe isotope and non-magnetized strangelets within the framework of the MIT bag model. It is concluded that the presence of a magnetic field tends to stabilize more the strangelets, even when temperature is considered. We find that the electric charge is modified in the presence of the magnetic field, leading to higher charge values for magnetized strangelets, when compared to the non-magnetized case

    Neuroprotection, Photoperiod, and Sleep

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    After an acquired brain injury, responses that induce cell death are activated; however, neuroprotective mechanisms are also activated. The relation between these responses determines the destination of the damaged tissue. This relation presents variations throughout the day; numerous studies have shown that the onset of a stroke occurs preferably in the morning. In the rat, ischemia causes more damage when it is induced during the night. The damage caused by a traumatic brain injury (TBI), in the rat, varies depending on the time of day it is induced. Minor behavioral damage has been reported when the TBI occurs during the night, a period that coincides with the wakefulness of the rat. It also has been observed that sleep deprivation accelerates the recovery. Our group has documented that this is due, in part, to a difference in the degree of activation of cannabinergic, GABAergyc, and glutamatergic systems
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