808 research outputs found

    The galaxy density environment of gamma-ray burst host galaxies

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    We analyze cross-correlation functions between Gamma-Ray Burst (GRB) hosts and surrounding galaxies. We have used data obtained with the Very Large Telescope at Cerro Paranal (Chile), as well as public Hubble Space Telescope data. Our results indicate that Gamma-Ray Burst host galaxies do not reside in high galaxy density environments. Moreover, the host-galaxy cross-correlations show a relatively low amplitude. Our results are in agreement with the cross-correlation function between star-forming galaxies and surrounding objects in the HDF-N.Comment: 6 figures, accepted for publication in Ap

    Imaging how and where we breathe oxygen: Another Big Short?

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    The Big Short tells the story of a small group of skeptics who profited from the financial crisis in 2007 by betting against collateralized (mortgage) debt obligations (CDO). Importantly, the novel paints a clear picture of the eccentric nature of contrarians who think divergently and against the grain or bet against an accepted truth or “sure” thing. In a similar manner, Ishii and co-workers’ recent work describes their team’s development of a pulmonary imaging technology that provides divergent and disruptive in vivo lung measurements of oxygen partial pressure in the context of the prevailing and longstanding consensus around FEV1 as the definitive diagnostic of chronic lung disease. The Big Short tells the story of a small group of skeptics who profited from the financial crisis in 2007 by betting against collateralized (mortgage) debt obligations (CDO). Importantly, the novel paints a clear picture of the eccentric nature of contrarians who think divergently and against the grain or bet against an accepted truth or “sure” thing. In a similar manner, Ishii and co-workers’ recent work describes their team’s development of a pulmonary imaging technology that provides divergent and disruptive in vivo lung measurements of oxygen partial pressure in the context of the prevailing and longstanding consensus around FEV1 as the definitive diagnostic of chronic lung disease

    Using heterogeneous wireless sensor networks in a telemonitoring system for healthcare

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    Abstract—Ambient intelligence has acquired great importance in recent years and requires the development of new innovative solutions. This paper presents a distributed telemonitoring system, aimed at improving healthcare and assistance to dependent people at their homes. The system implements a service-oriented architecture based platform, which allows heterogeneous wireless sensor networks to communicate in a distributed way independent of time and location restrictions. This approach provides the system with a higher ability to recover from errors and a better flexibility to change their behavior at execution time. Preliminary results are presented in this paper. Index Terms—Ambient intelligence (AmI), healthcare, servicesoriented architectures (SOAs), wireless sensors networks (WSNs)

    Wireless Sensor Networks and Real-Time Locating Systems to Fight against Maritime Piracy

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    There is a wide range of military and civil applications where Wireless Sensor Networks (WSNs) and Multi-Agent Systems (MASs) can be used for providing context-awareness for troops and special corps. On the one hand, WSNs comprise an ideal technology to develop Real-Time Locating Systems (RTLSs) aimed at indoor environments, where existing global navigation satellite systems do not work properly. On the other hand, agent-based architectures allow building autonomous and robust systems that are capable of working on highly dynamic scenarios. This paper presents two piracy scenarios where the n-Core platform can be applied. n-Core is a hardware and software platform intended for developing and deploying easily and quickly a wide variety of WSNs applications based on the ZigBee standard. In the first scenario a RTLS is deployed to support boarding and rescue operations. In the second scenario a multi-agent system is proposed to detect the unloading of illegal traffic of merchandise at ports

    Vaginal alpha-lipoic acid shows an anti-inflammatory effect on the cervix, preventing its shortening after primary tocolysis. A pilot, randomized, placebo-controlled study

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    Introduction: Inflammation might be an important underlying cause of preterm birth. Our aim is to explore whether vaginal administration α-lipoic acid reduces cervical inflammation and shortening after primary tocolysis. Materials and methods: Singleton pregnancies between 24–30 weeks remaining undelivered after hospitalization for preterm labor were randomly allocated to placebo (20 women, 15 analyzed) or vaginal ALA 400 mg (active ingredient 10 mg) daily (20 women, 17 analyzed) for 30 days. A cervical swab to quantify pro-inflammatory (IL1, IL2, IL6, IL8, TNFα) and anti-inflammatory (IL4, IL10) cytokines as well as transvaginal ultrasound cervical length measurement (CL) were performed before and after treatment. Results: The % changes of pro-inflammatory cytokines do not differ between treatment groups, while IL4 significantly increases by vaginal ALA in comparison to placebo (118.0 ± 364.3% versus 29.9 ± 103.5%, p = 0.012). Combined anti-inflammatory cytokines show same trend (292.5 ± 208.5% versus 64.5 ± 107.4, p = 0.03). CL remains similar in vaginal ALA group (from 23.1 ± 6.6 to 20.80 ± 7.9 mm), while it significantly decreased in placebo group (from 20.4 ± 6.5 to 13.8 ± 7.5 mm, p < 0.001 versus Baseline; p = 0.003 versus vaginal ALA). Conclusion: Vaginal ALA significantly stimulates anti-inflammatory ILs in the cervix of undelivered women after a preterm labor episode. This effect is associated with a stabilization of the CL

    GenÎmica e biotecnologia aplicadas a adaptação a mudanças climåticas.

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    Mudanças climĂĄticas globais e seus impactos na agricultura. Pesquisa e desenvolvimento de tecnologias transgĂȘnicas. GenĂŽmica funcional para descoberta de genes de valor agronĂŽmico. Bancos de dados genĂŽmicos. GenĂŽmica comparativa. AnĂĄlise filogenĂ©tica de famĂ­lias gĂȘnicas. AplicaçÔes de tecnologias de sequenciamento de prĂłxima geração. Seleção em larga escala de eventos transgĂȘnicos. A Unidade Mista de Pesquisa em GenĂŽmica Aplicada a Mudanças ClimĂĄticas (UMiP GenClima)

    Further results on why a point process is effective for estimating correlation between brain regions

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    Signals from brain functional magnetic resonance imaging (fMRI) can be efficiently represented by a sparse spatiotemporal point process, according to a recently introduced heuristic signal processing scheme. This approach has already been validated for relevant conditions, demonstrating that it preserves and compresses a surprisingly large fraction of the signal information. Here we investigated the conditions necessary for such an approach to succeed, as well as the underlying reasons, using real fMRI data and a simulated dataset. The results show that the key lies in the temporal correlation properties of the time series under consideration. It was found that signals with slowly decaying autocorrelations are particularly suitable for this type of compression, where inflection points contain most of the information.Fil: Cifre, I.. Universitat Ramon Llull; EspañaFil: Zarepour Nasir Abadi, Mahdi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Horovitz, S. G.. National Institutes of Health; Estados UnidosFil: Cannas, Sergio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Chialvo, Dante Renato. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentin

    The effect of the sixth sulfur ligand in the catalytic mechanism of periplasmic nitrate reductase

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    The catalytic mechanism of nitrate reduction by periplasmic nitrate reductases has been investigated using theoretical and computational means. We have found that the nitrate molecule binds to the active site with the Mo ion in the +6 oxidation state. Electron transfer to the active site occurs only in the proton-electron transfer stage, where the MoV species plays an important role in catalysis. The presence of the sulfur atom in the molybdenum coordination sphere creates a pseudo-dithiolene ligand that protects it from any direct attack from the solvent. Upon the nitrate binding there is a conformational rearrangement of this ring that allows the direct contact of the nitrate with MoVI ion. This rearrangement is stabilized by the conserved methionines Met141 and Met308. The reduction of nitrate into nitrite occurs in the second step of the mechanism where the two dimethyl-dithiolene ligands have a key role in spreading the excess of negative charge near the Mo atom to make it available for the chemical reaction. The reaction involves the oxidation of the sulfur atoms and not of the molybdenum as previously suggested. The mechanism involves a molybdenum and sulfur-based redox chemistry instead of the currently accepted redox chemistry based only on the Mo ion. The second part of the mechanism involves two protonation steps that are promoted by the presence of MoV species. MoVI intermediates might also be present in this stage depending on the availability of protons and electrons. Once the water molecule is generated only the MoVI species allow water molecule dissociation, and, the concomitant enzymatic turnover.Fil: Cerqueira, N.M.F.S.A.. Faculdade de CiĂȘncias E Tecnologia, Universidade Nova de Lisboa; PortugalFil: Gonzalez, P.J.. Faculdade de CiĂȘncias E Tecnologia, Universidade Nova de Lisboa; PortugalFil: Brondino, Carlos Dante. Universidad Nacional del Litoral; ArgentinaFil: RomĂŁo, M.J.. Faculdade de CiĂȘncias E Tecnologia, Universidade Nova de Lisboa; PortugalFil: RomĂŁo, C.C.. Instituto de Tecnologia Qu&Fil: Moura, I.. Faculdade de CiĂȘncias E Tecnologia, Universidade Nova de Lisboa; PortugalFil: Moura, J.J.G.. Faculdade de CiĂȘncias E Tecnologia, Universidade Nova de Lisboa; Portuga

    Dynamically altered conductance in an Organic Thin Film Memristive Device

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    The memristive device is one of the basic elements of novel, brain-inspired, fast, and energy-efficient information processing systems in which there is no separation between memorization and information analysis functions. Since the first demonstration of the resistive switching effect, several types of memristive devices have been developed. In most of them, the memristive effect originates from direct modification of the conducting area, e.g. conducting filament formation/disintegration, or semiconductor doping/dedoping. Here, we report a solution-processed lateral memristive device based on a new conductivity modulation mechanism. The device architecture resembles that of an organic field-effect transistor in which the top gate electrode is replaced with an additional insulator layer containing mobile ions. Alteration of the ion distribution under the influence of applied potential changes the electric field, modifying the conductivity of the semiconductor channel. The devices exhibit highly stable current-voltage hysteresis loops and Short-Term Plasticity (STP). We also demonstrate short-term synaptic plasticity with tunable time constants

    Self-organizing multi-agent system for management and planning surveillance routes

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    This paper presents the THOMAS architecture, specially designed to model open multi-agent systems, and its application in the development of a multi-agent system for managing and planning surveillance routes for security personnel. THOMAS uses agents with reasoning and planning capabilities. These agents can perform a dynamic self-organization when they detect changes in the environment. THOMAS is appropriate for developing systems in highly dynamic environments similar to the one presented in this study, as demonstrated by the results obtained after having applied the system to a case study.Web of Science3151100108
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