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See detailFirst Order Phase Transition in FePt/FeRh Bilayers
Ostler, Thomas ULg; Barton, Craig; Hrkac, Gino et al

Conference (2016, November 01)

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See detailThe puzzling properties of the magnetic O star Tr16-22
Nazé, Yaël ULg; Barbá, Rodolfo; Bagnulo, Stefano et al

in Astronomy and Astrophysics (2016), 596(A44), 1-7

Context. The detection of bright, hard, and variable X-ray emission in Tr16-22 prompted spectropolarimetric observations of this star, which in turn led to the discovery of a surface magnetic field. <BR ... [more ▼]

Context. The detection of bright, hard, and variable X-ray emission in Tr16-22 prompted spectropolarimetric observations of this star, which in turn led to the discovery of a surface magnetic field. <BR /> Aims: We want to further constrain the properties of this star, in particular to verify whether X-ray variations are correlated to changes in optical emission lines and magnetic field strength, as expected from the oblique rotator model that is widely accepted for magnetic O stars. <BR /> Methods: We have obtained new low-resolution spectropolarimetric and long-term high-resolution spectroscopic monitoring of Tr16-22, and we also analyse new, serendipitous X-ray data. <BR /> Results: The new X-ray observations are consistent with previous data, but their addition does not help to solve the ambiguity in the variation timescale because of numerous aliases. No obvious periodicity or any large variations are detected in the spectropolarimetric data of Tr16-22 obtained over three months. The derived field values appear to be in line with previous measurements, suggesting constancy of the field (though the possibility of small, short-term field variations cannot be excluded). Variations in the equivalent widths of Hα are very small, and they do not appear to be related to the X-ray timescale; the overall lack of large variations in optical emission lines is consistent with the magnetic field constancy. In addition, variations of the radial velocities indicate that Tr16-22 is probably a SB1 binary with a very long period. <BR /> Conclusions: Our new measurements of optical emission lines and magnetic field strength do not show an obvious correlation with X-ray variations. Our current data thus cannot be interpreted in terms of the common model, which assumes the electromagnetic emission associated with a wind confined by a dipolar field tilted with respect to the rotation axis. However, the sampling is imperfect and new data are needed to further constrain the actual periodicity of the various observed phenomena. If inconsistencies are confirmed, then we will need to consider alternative scenarios. Based on XMM-Newton observations (ObsIDs 0691970101, 0742850301, 0742850401, 0762910401) and ESO data (Prog. 386.D-0624A, 086.D-0997B, 089.D-0975A, 091.D-0090B, 095.D-0082).The reduced polarisation spectra (as ascii files) are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/596/A44">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/596/A44</A> [less ▲]

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See detailSupramolecular influence on cis–trans isomerization probed by ion mobility spectrometry
Czerwinska, Izabella; Kulesza, Alexander; Choi, Changmin et al

in Physical Chemistry Chemical Physics [=PCCP] (2016), 18

We used tandem ion mobility spectrometry measurements to investigate how the photo-isomerization of a chromophore (a methylpyridinium derivative) is affected by the complexation with a crown ether. A ... [more ▼]

We used tandem ion mobility spectrometry measurements to investigate how the photo-isomerization of a chromophore (a methylpyridinium derivative) is affected by the complexation with a crown ether. A dramatic blue-shift of the photo-isomerization spectrum was observed upon complexation, which could be well reproduced by ab initio calculations. Our results support that the observed changes in the photo-physical properties of the chromophore originate from the charge-solvation of its pyridinium moiety by the host cage. [less ▲]

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See detailGaia Data Release 1. Summary of the astrometric, photometric, and survey properties
Gaia Collaboration; Brown, A. G. A.; Vallenari, A. et al

in Astronomy and Astrophysics (2016), 595

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. <BR ... [more ▼]

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. <BR /> Aims: A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. <BR /> Methods: The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. <BR /> Results: Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of 3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr[SUP]-1[/SUP] for the proper motions. A systematic component of 0.3 mas should be added to the parallax uncertainties. For the subset of 94 000 Hipparcos stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr[SUP]-1[/SUP]. For the secondary astrometric data set, the typical uncertainty of the positions is 10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to 0.03 mag over the magnitude range 5 to 20.7. <BR /> Conclusions: Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data. [less ▲]

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See detailThe Gaia mission
Gaia Collaboration; Prusti, T.; de Bruijne, J. H. J. et al

in Astronomy and Astrophysics (2016), 595

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept ... [more ▼]

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page. <A href="http://www.cosmos.esa.int/gaia">http://www.cosmos.esa.int/gaia</A> [less ▲]

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See detailFrom Dictionary to Terminologies / Ontologies in General Practice/Family Medicine
Gusso, Gustavo; Jamoulle, Marc ULg

in The World Book of Family Medicine – Iberoamericana Edition 2016 (2016)

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See detailLe réseau d’énergie électrique a-t-il un avenir ? (livre blanc)
Lilien, Jean-Louis ULg

Diverse speeche and writing (2016)

Il s'agit d'un livre blanc sur l'avenir du réseau d'énergie électrique : devra-t-il encore exister demain ? Quels sont les avantages et les inconvénients soit du système actuel soit des micro-réseaux ... [more ▼]

Il s'agit d'un livre blanc sur l'avenir du réseau d'énergie électrique : devra-t-il encore exister demain ? Quels sont les avantages et les inconvénients soit du système actuel soit des micro-réseaux individuels ? [less ▲]

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See detailPREDetector 2.0: Online and Enhanced Version of the Prokaryotic Regulatory Elements Detector Tool
Tocquin, Pierre ULg; Naomé, Aymeric ULg; Jourdan, Samuel ULg et al

E-print/Working paper (2016)

In the era that huge numbers of microbial genomes are being released in the databases, it becomes increasingly important to rapidly mine genes as well as predict the regulatory networks that control their ... [more ▼]

In the era that huge numbers of microbial genomes are being released in the databases, it becomes increasingly important to rapidly mine genes as well as predict the regulatory networks that control their expression. To this end, we have developed an improved and online version of the PREDetector software aimed at identifying putative transcription factor-binding sites (TFBS) in bacterial genomes. The original philosophy of PREDetector 1.0 is maintained, i.e. to allow users to freely fix the DNA-motif screening parameters, and to provide a statistical means to estimate the reliability of the prediction output. This new version offers an interactive table as well as graphics to dynamically alter the main screening parameters with automatic update of the list of identified putative TFBS. PREDetector 2.0 also has the following additional options: (i) access to genome sequences from different databases, (ii) access to weight matrices from public repositories, (iii) visualization of the predicted hits in their genomic context, (iv) grouping of hits identified in the same upstream region, (v) possibility to store the performed jobs, and (vi) automated export of the results in various formats. PREDetector 2.0 is available at http://predetector.fsc.ulg.ac.be/. [less ▲]

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See detailSpeech style manipulations in dysarthria in French-speaking children: Acoustic findings.
Ancelle, Josephine; Moya Gale, G.; Hetrick, B et al

Poster (2016, November)

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See detailMeasurements of reference ISO nozzles by high-speed imaging
De Cock, Nicolas ULg; Massinon, Mathieu ULg; Nuyttens, David et al

in Crop Protection (2016), 89

Agricultural spray characteristics determine the efficiency of a pesticide application because size and velocity affect droplet trajectory and impact behavior. At present, the relevance of different ... [more ▼]

Agricultural spray characteristics determine the efficiency of a pesticide application because size and velocity affect droplet trajectory and impact behavior. At present, the relevance of different characterization techniques remains controversial since discrepancies may be significant between measurements performed in different laboratories. A digital image acquisition technique and analysis algorithm is proposed for droplet size and velocimetry measurements as an alternative to well-established techniques such as the Phase Doppler Particle Analyzer (PDPA) or laser diffraction spectrometry (LDS). The algorithm requires double exposed shadow images acquired in a back-lighted arrangement with a Particle Image Velocimetry (PIV) camera and a pulsed light emitting diode (LED). Spatial illumination heterogeneities are corrected by subtracting from each image a mean background acquired on several images without any particle. The algorithm accuracy is ensured by the rejection of out-of-focus particles using a focus parameter depending on gradient intensity at the particle edges. Thresholds for focus particle selection were determined by studying the evolution of the focus parameter and the error on particle size measurements from images containing droplets with uniform size at various distance of the object plane. Selected droplets were identified on both pairs of images to determine their size and velocity. Droplet size distributions were corrected to account for the uneven sampling probability caused by the volumetric method. Droplet size distributions of a set of reference nozzle/pressure combinations defined in the ISO/DIS 25358 were measured. The image technique was able to distinguish each of the reference sprays well. Comparison with PDPA measurements showed that the imaging technique tends to measure an equivalent Dv50, a lower Dv10 and a higher Dv90 leading therefore to a higher relative span factor. Velocity measurements showed good agreement between both techniques except for one nozzle/pressure combination. [less ▲]

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See detailLa médiation, un "quasi-concept"
Servais, Christine ULg

in Servais, Christine (Ed.) La médiation. Théorie et terrains (2016)

Il s'agit d'une présentation des problématiques qui traversent l'ouvrage à partir du constat d'un écart entre l'approche théorique de la médiation et son approche par les pratiques.

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See detailNonlinear dynamical tunneling of optical whispering gallery modes in the presence of a Kerr nonlinearity
Shim, Jeong -Bo ULg; Schlagheck, Peter ULg; Hentschel, Martina et al

in Physical Review A (2016), 94

The effect of a Kerr nonlinearity on dynamical tunneling is studied, using coupled whispering gallery modes in an optical microcavity. The model system that we have chosen is the “add-drop filter,” which ... [more ▼]

The effect of a Kerr nonlinearity on dynamical tunneling is studied, using coupled whispering gallery modes in an optical microcavity. The model system that we have chosen is the “add-drop filter,” which is comprised of an optical microcavity and two waveguides coupled to the cavity. Due to the evanescent fields scattering on the waveguide, the whispering gallery modes in the microcavity form doublets, which manifest themselves as splittings in the spectrum. As these doublets can be regarded as a spectral feature of dynamical tunneling between two different dynamical states with a spatial overlap, the effect of a Kerr nonlinearity on the doublets is numerically investigated in the more general context of the relationship between cubic nonlinearity and dynamical tunneling. Within the numerical realization of the model system, it is observed that the doublets show a bistable transition in their transmission curve as the Kerr nonlinearity in the cavity is increased. At the same time, one rotational mode becomes dominant over the other one in the transmission, since the two states in the doublet have uneven linewidths. By using coupled-mode theory, the underlying mode dynamics of the phenomena is theoretically modeled and clarified. [less ▲]

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See detailReverse Traceroute with DisNETPerf, a Distributed Internet Paths Performance Analyzer
Wassermann, Sarah ULg; Casas, Pedro

in Proc. Demonstrations of the 41th Annual IEEE Conference on Local Computer Networks (LCN-Demos 2016) (2016)

Traceroute is the most widely used Internet path diagnosis tool today. A major limitation of traceroute when the destination is not controllable by the user is its inability to measure reverse paths, i.e ... [more ▼]

Traceroute is the most widely used Internet path diagnosis tool today. A major limitation of traceroute when the destination is not controllable by the user is its inability to measure reverse paths, i.e., the path from a destination back to the source. In this demo session, we showcase DisNETPerf, a new tool to perform reverse traceroute measurements. DisNETPerf is able to collect measurements from the server to the user for path performance monitoring and troubleshooting purposes, even when the server is not under the control of the experimenter. DisNETPerf uses RIPE Atlas, a largely distributed active measurements platform to perform traceroute measurements from any arbitrarily selected server in the Internet. [less ▲]

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See detailFreedom of religion in the workplace in Belgium
Kéfer, Fabienne ULg

in Camas Roda, Ferran (Ed.) Exercising the right to freedom of religion in the workplace at the international and European level: A comparative study of the United Kingdom, France, Belgium and Spain (2016)

This conference explores the way in which Belgian law deals with situations where labour law engages with the right to freedom of religion and belief and the right not to be discriminated on grounds of ... [more ▼]

This conference explores the way in which Belgian law deals with situations where labour law engages with the right to freedom of religion and belief and the right not to be discriminated on grounds of religion. It starts with the Belgian regime of religious freedom, protection against discrimination and valid reasons for termination of employment. It then considers specific areas of those regimes in Belgian labour relations, such as the work schedule accommodation, the refusal to perform work, clothing and religious symbols in the workplace, and the work in an ethos organization. It relates mainly to Belgian case law but also to the case law of the European courts [less ▲]

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See detailAttack-Prevention and Damage-Control Investments in Cybersecurity
Lam, Wing Man Wynne ULg

Scientific conference (2016, November)

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See detailSleep and Electroencephalography, Preprocessing and analyses of a specific sleep EEG pattern
Coppieters't Wallant, Dorothe ULg

Doctoral thesis (2016)

Preprocessing and analyses of a specific sleep EEG pattern. Automatic detection methods, self-adjustable to individuals characteristics, were developed in order to remove artefacts from EEG sleep ... [more ▼]

Preprocessing and analyses of a specific sleep EEG pattern. Automatic detection methods, self-adjustable to individuals characteristics, were developed in order to remove artefacts from EEG sleep recordings, detect sleep spindles and analyse NREM power spectrum. Methods are described, assessed and discussed. [less ▲]

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See detailRecension de l'ouvrage de G. Rosoux : Vers une "dématérialisation" des droits fondamentaux?
Bouhon, Frédéric ULg

in Revue de la Faculté de Droit de l'Université de Liège (2016), 2016(3), 631-633

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See detailExtraction Socket Management with Buccal Plate Expansion: Preliminary Results of a Novel Technique
Fernandez Ayora, Alberto; González-Martín, Oscar; ROMPEN, Eric ULg et al

in International Journal of Periodontics & Restorative Dentistry (2016), 36(6),

The primary objective of this pilot study was to evaluate a new socket preservation technique involving the intentional expansion of the extraction socket buccal plate using a flapless internal ... [more ▼]

The primary objective of this pilot study was to evaluate a new socket preservation technique involving the intentional expansion of the extraction socket buccal plate using a flapless internal corticotomy and biomaterials. A total of 11 patients requiring tooth extraction were enrolled in this study. The aim of this technique was to maintain or improve the hard and soft tissue contour of the ridge after tooth extraction. All surgical sites healed uneventfully. Significant alveolar bone dimension changes were observed in the coronal region of the ridge (-1.4 ± 0.9 mm); however, it was only slightly lower at the medium (-0.35 ± 0.7 mm) and apical levels (-0.3 ± 0.8 mm) (P > .05). The ridge dimensional changes were significantly higher in the buccal aspect than in the palatal aspect in all patients. Vertical bone resorption was not significant. Concerning the soft tissue contour, the horizontal distance between the preoperative and postoperative buccal profiles ranged from 0.94 to -2.88 mm. The proposed ridge preservation technique may help maintain the volume of the healed ridge but cannot completely prevent contour changes after tooth extraction. [less ▲]

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See detailRobustness of spatial autocorrelation tests
Ernst, Marie ULg

Poster (2016, November)

Spatial autocorrelation expresses the dependence between values at neighbouring locations. Testing if the spatial autocorrelation is significant may confirm or deny the need to consider spatial analysis ... [more ▼]

Spatial autocorrelation expresses the dependence between values at neighbouring locations. Testing if the spatial autocorrelation is significant may confirm or deny the need to consider spatial analysis over the classical one. Indeed, the analysis of spatial data is only meaningful if the spatial components bring information. Several measures of spatial autocorrelation are defined in the literature. Moran’s index, Geary’s ratio and Getis-Ord statistic are the most used statistics. Tests based on these measures have been developed in the literature using asymptotic and permutation results. They are used in practice in many fields, for instance in geography, economics, biogeosciences, medicine, ... However, these tests should be cautiously applied because they are not robust. A single contaminated observation can significantly modify their results. This poster is composed of two parts. Firstly, the robustness of already available tools for measuring spatial autocorrelation will be analysed. Secondly, alternative methods will be proposed to robustly test the spatial autocorrelation. [less ▲]

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