1,436 research outputs found

    The angular power spectrum of radio emission at 2.3 GHz

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    We have analysed the Rhodes/HartRAO survey at 2326 MHz and derived the global angular power spectrum of Galactic continuum emission. In order to measure the angular power spectrum of the diffuse component, point sources were removed from the map by median filtering. A least-square fit to the angular power spectrum of the entire survey with a power law spectrum C_l proportional to l^{-alpha}, gives alpha = 2.43 +/- 0.01 for l = 2-100. The angular power spectrum of radio emission appears to steepen at high Galactic latitudes and for observed regions with |b| > 20 deg, the fitted spectral index is alpha = 2.92 +/- 0.07. We have extrapolated this result to 30 GHz (the lowest frequency channel of Planck) and estimate that no significant contribution to the sky temperature fluctuation is likely to come from synchrotron at degree-angular scalesComment: 10 pages, 10 figures, accepted for publication by Astronomy & Astrophysic

    Analysis of CMB foregrounds using a database for Planck

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    Within the scope of the Planck IDIS (Integrated Data Information System) project we have started to develop the data model for time-ordered data and full-sky maps. The data model is part of the Data Management Component (DMC), a software system designed according to a three-tier architecture which allows complete separation between data storage and processing. The DMC is already being used for simulation activities and the modeling of some foreground components. We have ingested several Galactic surveys into the database and used the science data-access interface to process the data. The data structure for full-sky maps utilises the HEALPix tessellation of the sphere. We have been able to obtain consistent measures of the angular power spectrum of the Galactic radio continuum emission between 408 MHz and 2417 MHz.Comment: 7 pages, 6 figures. To appear in the Proceedings of the MPA/ESO/MPE Joint Astronomy Conference "Mining The Sky

    Affect and Cognition in Managerial Decision Making: A Systematic Literature Review of Neuroscience Evidence

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    How do affect and cognition interact in managerial decision making? Over the last decades, scholars have investigated how managers make decisions. However, what remains largely unknown is the interplay of affective states and cognition during the decision-making process. We offer a systematization of the contributions produced on the role of affect and cognition in managerial decision making by considering the recent cross-fertilization of management studies with the neuroscience domain. We implement a Systematic Literature Review of 23 selected contributions dealing with the role of affect and cognition in managerial decisions that adopted neuroscience techniques/points of view. Collected papers have been analyzed by considering the so-called reflexive (X-) and reflective (C-) systems in social cognitive neuroscience and the type of decisions investigated in the literature. Results obtained help to support an emerging “unified” mind processing theory for which the two systems of our mind are not in conflict and for which affective states have a driving role toward cognition. A research agenda for future studies is provided to scholars who are interested in advancing the investigation of affect and cognition in managerial decision making, also through neuroscience techniques – with the consideration that these works should be at the service of the behavioral strategy field

    Holographic Technidilaton and LHC searches

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    We analyze in detail the phenomenology of a model of dynamical electroweak symmetry breaking inspired by walking technicolor, by using the techniques of the bottom-up approach to holography. The model admits a light composite scalar state, the dilaton, in the spectrum. We focus on regions of parameter space for which the mass of such dilaton is 125 GeV, and for which the bounds on the precision electroweak parameter S are satisfied. This requires that the next-to-lightest composite state is the techni-rho meson, with a mass larger than 2.3 TeV. We compute the couplings controlling the decay rates of the dilaton to two photons and to two (real or virtual) Z and W bosons. For generic choices of the parameters, we find a suppression of the decay into heavy gauge bosons, in respect to the analog decay of the standard-model Higgs. We find a dramatic effect on the decay into photons, which can be both strongly suppressed or strongly enhanced, the latter case corresponding to the large-N regime of the dual theory. There is a correlation between this decay rate of the dilaton into photons and the mass splitting between the techni-rho meson and its axial-vector partner: if the decay is enhanced in respect to the standard-model case, then the heavy spin-1 resonances are nearly degenerate in mass, otherwise their separation in mass is comparable to the mass scale itself.Comment: Very minor typos corrected. References adde

    Spectrophotometric properties of dwarf planet Ceres from the VIR spectrometer on board the Dawn mission

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    We study the spectrophotometric properties of dwarf planet Ceres in the VIS-IR spectral range by means of hyper-spectral images acquired by the VIR imaging spectrometer on board the NASA Dawn mission. Disk-resolved observations with a phase angle within the 7<α<1327^{\circ}<\alpha<132^{\circ} interval were used to characterize Ceres' phase curve in the 0.465-4.05 μ\mum spectral range. Hapke's model was applied to perform the photometric correction of the dataset, allowing us to produce albedo and color maps of the surface. The VV-band magnitude phase function of Ceres was fitted with both the classical linear model and H-G formalism. The single-scattering albedo and the asymmetry parameter at 0.55μ\mum are w=0.14±0.02w=0.14\pm0.02 and ξ=0.11±0.08\xi=-0.11\pm0.08, respectively (two-lobe Henyey-Greenstein phase function); the modeled geometric albedo is 0.094±0.0070.094\pm0.007; the roughness parameter is θˉ=29±6\bar{\theta}=29^{\circ}\pm6^{\circ}. Albedo maps indicate small variability on a global scale with an average reflectance of 0.034±0.0030.034 \pm 0.003. Isolated areas such as the Occator bright spots, Haulani, and Oxo show an albedo much higher than average. We measure a significant spectral phase reddening, and the average spectral slope of Ceres' surface after photometric correction is 1.1%kA˚11.1\%k\AA^{-1} and 0.85%kA˚10.85\%k\AA^{-1} at VIS and IR wavelengths, respectively. Broadband color indices are VR=0.38±0.01V-R=0.38\pm0.01 and RI=0.33±0.02R-I=0.33\pm0.02. H-G modeling of the VV-band magnitude phase curve for α<30\alpha<30^{\circ} gives H=3.14±0.04H=3.14\pm0.04 and G=0.10±0.04G=0.10\pm0.04, while the classical linear model provides V(1,1,0)=3.48±0.03V(1,1,0^{\circ})=3.48\pm0.03 and β=0.036±0.002\beta=0.036\pm0.002. The comparison with spectrophotometric properties of other minor bodies indicates that Ceres has a less back-scattering phase function and a slightly higher albedo than comets and C-type objects. However, the latter represents the closest match in the usual asteroid taxonomy.Comment: 14 pages, 20 figures, published online on Astronomy and Astrophysics on 13 February 2017. Revised to reflect minor changes in text and figures made in proofs, updated value of V-R and R-

    Hardware prototyping and validation of a W-ΔDOR digital signal processor

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    Microwave tracking, usually performed by on ground processing of the signals coming from a spacecraft, represents a crucial aspect in every deep-space mission. Various noise sources, including receiver noise, affect these signals, limiting the accuracy of the radiometric measurements obtained from the radio link. There are several methods used for spacecraft tracking, including the Delta-Differential One-Way Ranging (ΔDOR) technique. In the past years, European Space Agency (ESA) missions relied on a narrowband ΔDOR system for navigation in the cruise phase. To limit the adverse effect of nonlinearities in the receiving chain, an innovative wideband approach to ΔDOR measurements has recently been proposed. This work presents the hardware implementation of a new version of the ESA X/Ka Deep Space Transponder based on the new tracking technique named Wideband ΔDOR (W-ΔDOR). The architecture of the new transponder guarantees backward compatibility with narrowband ΔDOR

    Post-operative quality of life after single-visit root canal treatment employing three different instrumentation techniques—An institutional randomized clinical trial

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    Root canal treatment (RCT) eliminates damaged pulpal tissue and protects the tooth from recurrent microbial invasion. Post-endodontic pain (PEP) is a frequently encountered complication of root canal therapy. It can have an impact on patients’ quality of life (QoL) and their subjective perception of treatment options. Thus, a self-assessment questionnaire was used to evaluate and compare the influence of manual, rotary, and reciprocating file shaping procedures on immediate post-operative quality of life (POQoL) involving single-visit root canal therapy. It was a double-blinded, randomized, controlled clinical trial. A total of 120 participants were randomly assigned sequentially to three groups comprising 40 patients in each group: Group A: Hand K file (positive control); Group B: ProTaper Next file system; and Group C: WaveOne Gold. Post-operative pain was evaluated using a 4-point visual analog scale (VAS) after 12 h, 24 h, 48 h, 72 h, and 1 week. The highest post-operative pain was with manual instrumentation using hand K files, and the lowest was with reciprocating and rotating instrumentations. No significant difference was noted between the parameters of quality of life assessed, suggesting the filing system or technique had a similar effect
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