338 research outputs found

    Early stages of surface alteration of soda-rich-silicate glasses in the museum environment

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    This paper studied the alteration of three soda-rich-silicate glass types (Cristallo, façon-de-Venise and soda-lime silicate). Replica samples were exposed to different environments simulating museum-like conditions – room temperature and different relative humidities (RH). Results were analysed by SIMS, μ-FTIR, Optical Microscopy and Optical 3D profilometry. Cristallo appears as the most vulnerable, whilst the soda-lime glass appears as the most resistant to the environmental deterioration. The thickness of the altered layer is proportional to the time of exposure and to the RH of the surrounding atmosphere. From the results obtained, the glass composition and the water available and adsorbed to the surface strongly influence the kinetics of the surface alteration

    Using street based metrics to characterize urban typologies

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    [EN] Urban spatial structures reflect local particularities produced during the development of a city. High spatial resolution imagery and LiDAR data are currently used to derive numerical attributes to describe in detail intra-urban structures and morphologies. Urban block boundaries have been frequently used to define the units for extracting metrics from remotely sensed data. In this paper, we propose to complement these metrics with a set of novel descriptors of the streets surrounding the urban blocks under consideration. These metrics numerically describe geometrical properties in addition to other distinctive aspects, such as presence and properties of vegetation and the relationship between the streets and buildings. For this purpose, we also introduce a methodology for partitioning the street area related to an urban block into polygons from which the street urban metrics are derived. We achieve the assessment of these metrics through application of a one-way ANOVA procedure, the winnowing technique, and a decision tree classifier. Our results suggest that street metrics, and particularly those describing the street geometry, are suitable for enhancing the discrimination of complex urban typologies and help to reduce the confusion between certain typologies. The overall classification accuracy increased from 72.7% to 81.1% after the addition street of descriptors. The results of this study demonstrate the usefulness of these metrics for describing street properties and complementing information derived from urban blocks to improve the description of urban areas. Street metrics are of particular use for the characterization of urban typologies and to study the dynamics of cities.The authors appreciate the financial support provided by the Spanish Ministry of Science and Innovation in the framework of the project CGL2010-19591/BTE, and the data made available by the Spanish Instituto Geográfico Nacional (IGN)Hermosilla, T.; Palomar-Vázquez, J.; Balaguer Beser, ÁA.; Balsa Barreiro, J.; Ruiz Fernández, LÁ. (2014). Using street based metrics to characterize urban typologies. Computers, Environment and Urban Systems. 44:68-79. https://doi.org/10.1016/j.compenvurbsys.2013.12.002S68794

    The Secret Processor Will Go to The Ball: Benchmark Insider-Proof Encrypted Computing

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    `Encrypted computing\u27 is an approach to the prevention of insider attacks by the privileged operator against the unprivileged user on a computation system. It requires a processor that works natively on encrypted data in user mode, and the security barrier that protects the user is hardware-based encryption, not access protocols. We report on progress and practical experience with our superscalar RISC class prototype processor for encrypted computing and the supporting software infrastructure. It has been shown formally impossible for operator mode to read (or write to order) the plaintext form of data originating from or being operated on in the user mode of this class of processor, given that the encryption is independently secure. This paper aims to alert the secure hardware community that encrypted computing is possibly practical, not only theoretically plausible. The standard Dhrystone benchmark reported here for AES-128 encrypted computation shows performance equivalent to a 433MHz classic Pentium at the prototype\u27s 1GHz base clock

    La denominación de origen Cariñena como sistema productivo local: redes de empresas, cultura y gobernanza

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    Cariñena and its environs are a territory that can be considered as a local productive system, since there is a network of enterprises linked by trading relations –specially the integration of vine growing and wine production into cooperatives- and by cooperation relationships, being the Guarantee of Origin and Quality of Wine the clearest outcome. The analysis of a set of indicators calculated from official statistics and of a set of semi-structured interviews to the main agents has led to the knowledge of certain cognitive and organisational components of the system. Those identified are a low level of technical culture, a high level of entrepreneurial culture and a low institutional density, reflected in weak outcomes of network governance.Cariñena y su entorno es un territorio que puede calificarse como sistema productivo local, pues cuenta con una red de empresas vinculadas entre sí por relaciones de mercado -especialmente la integración de viticultura y vinicultura por medio de las cooperativas- y por relaciones de cooperación, de las que la denominación de origen es el resultado más patente. El análisis de un conjunto de indicadores calculados a partir de estadísticas oficiales y de una serie de entrevistas semiestructuradas a los principales agentes ha permitido aproximarse al conocimiento de determinados elementos cognitivos y de organización del sistema. Así, se han detectado un bajo nivel de cultura técnica, un alto nivel de cultura empresarial y una baja densidad institucional, que se refleja en unas débiles manifestaciones de gobernanza en red

    rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma decays in the local quark Nambu--Jona-Lasinio model

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    The branching ratios and photon spectra of the rare processes rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma are calculated in the framework of the standard local quark Nambu--Jona-Lasinio (NJL) model. Three types of diagrams are considered: the quark box and the pole diagrams with scalar (sigma,a_0(980)) and vector (rho,omega) mesons. The obtained estimations for the widths of the processes rho(omega)-> pi^0 pi^0 gamma are in satisfactory agreement with existing experimental data. Predictions are made for the widths of the processes rho(omega) -> eta pi^0 gamma.Comment: 6 pages, 5 figure

    ParaDIME: Parallel Distributed Infrastructure for Minimization of Energy for data centers

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    Dramatic environmental and economic impact of the ever increasing power and energy consumption of modern computing devices in data centers is now a critical challenge. On the one hand, designers use technology scaling as one of the methods to face the phenomenon called dark silicon (only segments of a chip function concurrently due to power restrictions). On the other hand, designers use extreme-scale systems such as teradevices to meet the performance needs of their applications which in turn increases the power consumption of the platform. In order to overcome these challenges, we need novel computing paradigms that address energy efficiency. One of the promising solutions is to incorporate parallel distributed methodologies at different abstraction levels. The FP7 project ParaDIME focuses on this objective to provide different distributed methodologies (software-hardware techniques) at different abstraction levels to attack the power-wall problem. In particular, the ParaDIME framework will utilize: circuit and architecture operation below safe voltage limits for drastic energy savings, specialized energy-aware computing accelerators, heterogeneous computing, energy-aware runtime, approximate computing and power-aware message passing. The major outcome of the project will be a noval processor architecture for a heterogeneous distributed system that utilizes future device characteristics, runtime and programming model for drastic energy savings of data centers. Wherever possible, ParaDIME will adopt multidisciplinary techniques, such as hardware support for message passing, runtime energy optimization utilizing new hardware energy performance counters, use of accelerators for error recovery from sub-safe voltage operation, and approximate computing through annotated code. Furthermore, we will establish and investigate the theoretical limits of energy savings at the device, circuit, architecture, runtime and programming model levels of the computing stack, as well as quantify the actual energy savings achieved by the ParaDIME approach for the complete computing stack with the real environment

    Monitoring new long-lasting intravitreal formulation for glaucoma with vitreous images using optical coherence tomography

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    Intravitreal injection is the gold standard therapeutic option for posterior segment patholo-gies, and long-lasting release is necessary to avoid reinjections. There is no effective intravitreal treatment for glaucoma or other optic neuropathies in daily practice, nor is there a non-invasive method to monitor drug levels in the vitreous. Here we show that a glaucoma treatment combining a hypotensive and neuroprotective intravitreal formulation (IF) of brimonidine–Laponite (BRI/LAP) can be monitored non-invasively using vitreoretinal interface imaging captured with optical coherence tomography (OCT) over 24 weeks of follow-up. Qualitative and quantitative characterisation was achieved by analysing the changes in vitreous (VIT) signal intensity, expressed as a ratio of retinal pigment epithelium (RPE) intensity. Vitreous hyperreflective aggregates mixed in the vitreous and tended to settle on the retinal surface. Relative intensity and aggregate size progressively decreased over 24 weeks in treated rat eyes as the BRI/LAP IF degraded. VIT/RPE relative intensity and total aggregate area correlated with brimonidine levels measured in the eye. The OCT-derived VIT/RPE relative intensity may be a useful and objective marker for non-invasive monitoring of BRI/LAP IF

    Higher meson resonances in ρπ0π0γ\rho \to \pi^0 \pi^0 \gamma and ωπ0π0γ\omega \to \pi^0 \pi^0 \gamma

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    The role of higher meson resonances with spin 1 and 2 is investigated quantitatively in the decay processes of ρπ0π0γ\rho \to \pi^0\pi^0 \gamma and ωπ0π0γ\omega \to \pi^0 \pi^0 \gamma. Among the higher resonances, we find that the f2(1270)f_2(1270) tensor meson can give a nontrivial contribution especially to the ωπ0π0γ\omega \to \pi^0 \pi^0 \gamma decay process. When the f2f_2 contribution is combined with the processes involving the vector and scalar meson intermediate states, a good agreement with the recent measurements is achieved for both decays. The effect of the f2(1270)f_2(1270) is found to be sizable at the intermediate photon energies and may be verified by precise measurements of the recoil photon spectrum of the ωπ0π0γ\omega \to \pi^0 \pi^0 \gamma decay. The dependence of the decay widths on various models for the ρ\rho-ω\omega mixing in the literature is also investigated.Comment: 16 pages, REVTeX, 6 figures, revised version, to appear in Phys. Rev.

    ηπ0γγ\eta \to \pi^0 \gamma \gamma decay within unitarized chiral perturbation theory

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    We improve the calculations of the ηπ0γγ\eta \to \pi^0 \gamma \gamma decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the a0(980)a_0(980) resonance and fixing the longstanding sign ambiguity on its contribution. This also allows us to calculate the loops with one vector meson exchange, thus removing a former source of uncertainty. In addition we ensure the consistency of the approach with other processes. First, by using vector meson dominance couplings normalized to agree with radiative vector meson decays. And, second, by checking the consistency of the calculations with the related γγπ0η\gamma \gamma \to \pi^0 \eta reaction. We find an ηπ0γγ\eta \to \pi^0 \gamma \gamma decay width of 0.47±0.100.47\pm 0.10 eV, in clear disagreement with published data but in remarkable agreement with the most recent measurement.Comment: 15 pages, 10 figures, published versio

    Voriconazole Use in Children: Therapeutic Drug Monitoring and Control of Inflammation as Key Points for Optimal Treatment

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    Infeccions fúngiques pediàtriques; Monitorització terapèutica de fàrmacs; VoriconazolInfecciones fúngicas pediátricas; Monitorización terapéutica de fármacos; VoriconazolPaediatric fungal infections; Therapeutic drug monitoring; VoriconazoleVoriconazole plasma concentrations (PC) are highly variable, particularly in children. Dose recommendations in 2–12-year-old patients changed in 2012. Little data on therapeutic drug monitoring (TDM) after these new recommendations are available. We aimed to evaluate voriconazole monitoring in children with invasive fungal infection (IFI) after implementation of new dosages and its relationship with safety and effectiveness. A prospective, observational study, including children aged 2–12 years, was conducted. TDM was performed weekly and doses were changed according to an in-house protocol. Effectiveness, adverse events, and factors influencing PC were analysed. A total of 229 PC from 28 IFI episodes were obtained. New dosing led to a higher rate of adequate PC compared to previous studies; still, 35.8% were outside the therapeutic range. In patients aged < 8 years, doses to achieve therapeutic levels were higher than recommended. Severe hypoalbuminemia and markedly elevated C-reactive protein were related to inadequate PC. Therapeutic PC were associated with drug effectiveness and safety. Higher doses in younger patients and a dose adjustment protocol based on TDM should be considered. Voriconazole PC variability has decreased with current updated recommendations, but it remains high and is influenced by inflammatory status. Additional efforts to control inflammation in children with IFI should be encouraged.This research was funded by an Investigator Sponsored Research Grant from Pfizer (Grant Number WI182544
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