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See detailDetecting microbial patterns in relation to soil agricultural practices and the plant development stage
Degrune, Florine ULg; Dufrêne, Marc ULg; Taminiau, Bernard ULg et al

Poster (2014, December 02)

Agricultural practices have a strong impact on soil bacteria and fungi. Furthermore, microbial community composition can change with the stage of plant development. We are interested in exploring these ... [more ▼]

Agricultural practices have a strong impact on soil bacteria and fungi. Furthermore, microbial community composition can change with the stage of plant development. We are interested in exploring these effects in relation to changes induced by agriculture and plant stage in soil conditions. Some bacteria are influenced only by the plant stage, which induces changes in soil humidity, pH, nitrates, and carbon. We would thus expect these bacteria to be highly sensitive to these parameters. Other bacteria are affected only by the tillage practice applied. Further study is needed to identify the soil parameters responsible for this effect. The plant stage also has a great impact on fungal community composition. [less ▲]

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See detailPsychometrics and bibliometrics: Overview of future possible interactions
Magis, David ULg

Scientific conference (2014, December 02)

Bibliometrics is a growing research field with the main aim of collecting bibliometric information (citations, publications, awards...) to infer valuable rankings or to predict future academic performance ... [more ▼]

Bibliometrics is a growing research field with the main aim of collecting bibliometric information (citations, publications, awards...) to infer valuable rankings or to predict future academic performance. However, most bibliometric approaches are based either on pairwise comparisons of "objects" (authors, funding applications, academics...) with respect to selected "criteria" (publications, citation rate, h-index...), or on modeling observable academic outcomes using observed such criteria. The purpose of this talk is twofold. First, an improvement of the pairwise comparison approach will be outlined on the basis of so-called multicriteria decision aid (MCDA) routines, which will imply an increased flexibility and added freedom for the decision process. Second, we will start a deeper reflexion on possible connections between bibliometrics and psychometrics. Among others, the possibility of modeling latent "academic ability" as outcome of interest, given manifest criteria, will be put to an open discussion and exchange with the listeners [less ▲]

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See detailAtelier ENMG pratique membre supérieur
WANG, François-Charles ULg

Scientific conference (2014, December 02)

Detailed reference viewed: 18 (4 ULg)
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See detailMid-winter freeze experiment in the Arctic Ocean: Norwegian Young sea ICE cruise (N-ICE2015)
Nomura, Daiki; Granskog, Mats A.; Fransson, Agneta et al

Poster (2014, December 02)

In mid-January 2015, RV Lance will freeze into the ice north of Svalbard, Arctic Ocean at around 83.25°N 30°E, and passively drift with the ice as part of the Norwegian Young sea ICE cruise (N-ICE2015 ... [more ▼]

In mid-January 2015, RV Lance will freeze into the ice north of Svalbard, Arctic Ocean at around 83.25°N 30°E, and passively drift with the ice as part of the Norwegian Young sea ICE cruise (N-ICE2015). Judging from historic sea ice drift trajectories, it is likely that RV Lance will drift in a SW direction and the ship will probably be freed from the ice in mid spring after about two to three months of drift. Thereafter, RV Lance will return to her starting position and start a new drift. Under all circumstances, the ice drift project will end in late June 2015. Throughout the cruise the focus will be on the interaction of the atmosphere-ice-ocean system and the response of the marine ecosystem to the thinner ice regime. The overall goal of the project team is to improve our understanding of the role of the younger ice pack in the Arctic on greenhouse gas fluxes and to ultimately assess whether the Arctic Ocean is a sink or source of greenhouse gases. We plan to conduct long-term synchronous observations of Arctic snow and sea ice biogeochemistry and physics and fluxes of carbon dioxide, methane, nitrous oxide and bromoform. This work targets at filling a crucial gap in our understanding of the role of Arctic sea ice in the climate system. This is done by conducting state of the art observations on Arctic sea ice in the polar night, when observations are basically non-existent. Further we are focusing on the new thinner ice regime, which is even less documented. We aim to understand how the thinner sea ice in the Arctic basin contributes (i) to important greenhouse gas exchange between the atmosphere and ocean and (ii) to aerosol formation, that contribute to the radiative balance of the planet. This work will increase direct collaboration between Japanese and European scientists in the Arctic, and combines complimentary expertise and experience from several international partners to carry out the interdisciplinary work proposed. [less ▲]

Detailed reference viewed: 46 (2 ULg)
See detailLa régulation du marché du travail par les intermédiaires privés
Gérard, Julie ULg

Conference (2014, December 02)

Detailed reference viewed: 14 (2 ULg)
See detailPhysisorbed poly(ethylene oxide) is a robust tether for AFM-based single-molecule force spectroscopy
Willet, Nicolas ULg; Lussis, Perrine ULg; Giamblanco, Nicoletta et al

Conference (2014, December 01)

Atomic force microscopy (AFM)-based single-molecule force spectroscopy is a prevalent tool for the exploration of individual (bio)molecules, providing exquisite information on many molecular-level ... [more ▼]

Atomic force microscopy (AFM)-based single-molecule force spectroscopy is a prevalent tool for the exploration of individual (bio)molecules, providing exquisite information on many molecular-level processes. For example, proteins, DNA, polysaccharides, supramolecular polymers and polyelectrolytes have been investigated, revealing details about the strength of intramolecular interactions, folding and unfolding pathways, mechanics, conformational changes, reactivity, kinetics, etc. For each particular system under investigation, the experimental design is a decisive phase that often involves a multistep chemical protocol, including grafting, derivatization, coupling, (de-)protection, and other functionalization reactions. Procedures of sample preparation are often complex and time-consuming. Hence, there is a need for new general platforms allowing for straightforward sample preparation adapted to single-molecule studies, i.e. a tight attachment to both the substrate and the tip, and a low density to favor single-molecule detection. We report here on the use of poly(ethylene oxide) (PEO) as a tether to probe various properties of individual molecules. The polymeric linker acts as a handle that stably binds to the AFM tip. The simple adsorption of poly(ethylene oxide) to the tip is versatile and provides an appropriate system configuration for the investigation of many different biological and synthetic molecular systems. To attest for this versatility and adequacy with advanced single-molecule investigation, we present different examples of PEO-mediated studies about the unfolding of a synthetic peptide, the mechanochemical behavior of a molecular machine and finally the stability of a metallo-supramolecular complexed polymer. All the requirements for the study of peptide conformation, tiny molecular machines or metallo-supramolecular interactions in solution are here fulfilled. More generally, this method based on non-covalent sorption of PEO on an AFM tip, can be implemented in a wide range of solvents, for the study of many intra- or intermolecular phenomena at the single-molecule level over orders of magnitude of force loading rates. Connecting PEO tethers to a very broad variety of (bio)molecules is a facile and versatile route. The commercial availability of many different functional PEOs makes this tethering strategy even more accessible. [less ▲]

Detailed reference viewed: 52 (3 ULg)
See detailL'âgisme
Marquet, Manon ULg; Schroyen, Sarah ULg

Conference (2014, December 01)

Detailed reference viewed: 14 (4 ULg)
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See detailAlignment of quasar polarizations with large-scale structures
Hutsemekers, Damien ULg; Braibant, Lorraine ULg; Pelgrims, Vincent ULg et al

in Astronomy and Astrophysics (2014), 572

We have measured the optical linear polarization of quasars belonging to Gpc scale quasar groups at redshift z ~ 1.3. Out of 93 quasars observed, 19 are significantly polarized. We found that quasar ... [more ▼]

We have measured the optical linear polarization of quasars belonging to Gpc scale quasar groups at redshift z ~ 1.3. Out of 93 quasars observed, 19 are significantly polarized. We found that quasar polarization vectors are either parallel or perpendicular to the directions of the large-scale structures to which they belong. Statistical tests indicate that the probability that this effect can be attributed to randomly oriented polarization vectors is on the order of 1%. We also found that quasars with polarization perpendicular to the host structure preferentially have large emission line widths while objects with polarization parallel to the host structure preferentially have small emission line widths. Considering that quasar polarization is usually either parallel or perpendicular to the accretion disk axis depending on the inclination with respect to the line of sight, and that broader emission lines originate from quasars seen at higher inclinations, we conclude that quasar spin axes are likely parallel to their host large-scale structures. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 092.A-0221.Table 1 is available in electronic form at <A href="http://www.aanda.org/10.1051/0004-6361/201424631/olm">http://www.aanda.org</A> [less ▲]

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See detailThe use of microorganisms of cassava retting for the production of pectinolytic enzymes
Kouhounde, Sonagnon Hermann Serge ULg; Adeoti, Kifouli; Delvigne, Frank ULg et al

in Journal of Microbiology Biotechnology and Food Sciences (2014), 4(3), 277-281

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See detailShort-term spectroscopic variability of Plaskett's star
Palate, Matthieu ULg; Rauw, Grégor ULg

in Astronomy and Astrophysics (2014), 572

Context. Plaskett's star (HD 47129) is a very massive O-star binary in a post Roche-lobe overflow stage. CoRoT observations of this system revealed photometric variability with a number of frequencies ... [more ▼]

Context. Plaskett's star (HD 47129) is a very massive O-star binary in a post Roche-lobe overflow stage. CoRoT observations of this system revealed photometric variability with a number of frequencies. <BR /> Aims: The aim of this paper is to characterize the variations in spectroscopy and investigate their origin. <BR /> Methods: To sample its short-term variability, HD 47129 was intensively monitored during two spectroscopic campaigns of six nights each. The spectra were disentangled and Fourier analyses were performed to determine possible periodicities and to investigate the wavelength dependence of the phase constant and the amplitude of the periodicities. <BR /> Results: Complex line profile variations are observed. Frequencies near 1.65, 0.82, and 0.37 d[SUP]-1[/SUP] are detected consistently in the He i λ 4471, He ii λ 4542, and N iii λ 4510-4518 lines. These frequencies are consistent with those of the strongest signals detected in photometry. The possibilities that these variations stem from pulsations, a recently detected magnetic field or tidal interactions are discussed. <BR /> Conclusions: Whilst all three scenarios have their strengths, none of them can currently account for all the observed properties of the line profile variations. Based on observations collected at the Observatoire de Haute Provence (OHP, France). [less ▲]

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See detailSe barricader : une solution insuffisante face à l'eau
de Muelenaere, Michel; Archambeau, Pierre ULg; Erpicum, Sébastien ULg et al

Article for general public (2014)

Detailed reference viewed: 20 (3 ULg)
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See detailMixed modes in red giants: a window on stellar evolution
Mosser, B.; Benomar, O.; Belkacem, K. et al

in Astronomy and Astrophysics (2014), 572

Context. The detection of oscillations with a mixed character in subgiants and red giants allows us to probe the physical conditions in their cores. <BR /> Aims: With these mixed modes, we aim at ... [more ▼]

Context. The detection of oscillations with a mixed character in subgiants and red giants allows us to probe the physical conditions in their cores. <BR /> Aims: With these mixed modes, we aim at determining seismic markers of stellar evolution. <BR /> Methods: Kepler asteroseismic data were selected to map various evolutionary stages and stellar masses. Seismic evolutionary tracks were then drawn with the combination of the frequency and period spacings. <BR /> Results: We measured the asymptotic period spacing for 1178 stars at various evolutionary stages. This allows us to monitor stellar evolution from the main sequence to the asymptotic giant branch and draw seismic evolutionary tracks. We present clear quantified asteroseismic definitions that characterize the change in the evolutionary stages, in particular the transition from the subgiant stage to the early red giant branch, and the end of the horizontal branch. <BR /> Conclusions: The seismic information is so precise that clear conclusions can be drawn independently of evolution models. The quantitative seismic information can now be used for stellar modeling, especially for studying the energy transport in the helium-burning core or for specifying the inner properties of stars entering the red or asymptotic giant branches. Modeling will also allow us to study stars that are identified to be in the helium-subflash stage, high-mass stars either arriving or quitting the secondary clump, or stars that could be in the blue-loop stage. Table 1 is only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/L5">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/L5</A> [less ▲]

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See detailWASP-94 A and B planets: hot-Jupiter cousins in a twin-star system
Neveu-VanMalle, M.; Queloz, D.; Anderson, D. R. et al

in Astronomy and Astrophysics (2014), 572

We report the discovery of two hot-Jupiter planets, each orbiting one of the stars of a wide binary system. <ASTROBJ>WASP-94A</ASTROBJ> (<ASTROBJ>2MASS 20550794-3408079</ASTROBJ>) is an F8 type star ... [more ▼]

We report the discovery of two hot-Jupiter planets, each orbiting one of the stars of a wide binary system. <ASTROBJ>WASP-94A</ASTROBJ> (<ASTROBJ>2MASS 20550794-3408079</ASTROBJ>) is an F8 type star hosting a transiting planet with a radius of 1.72 ± 0.06 R<SUB>Jup</SUB>, a mass of 0.452 ± 0.034 M<SUB>Jup</SUB>, and an orbital period of 3.95 days. The Rossiter-McLaughlin effect is clearly detected, and the measured projected spin-orbit angle indicates that the planet occupies a retrograde orbit. <ASTROBJ>WASP-94B</ASTROBJ> (<ASTROBJ>2MASS 20550915-3408078</ASTROBJ>) is an F9 stellar companion at an angular separation of 15'' (projected separation 2700 au), hosting a gas giant with a minimum mass of 0.618 ± 0.028 M<SUB>Jup</SUB> with a period of 2.008 days, detected by Doppler measurements. The orbital planes of the two planets are inclined relative to each other, indicating that at least one of them is inclined relative to the plane of the stellar binary. These hot Jupiters in a binary system bring new insights into the formation of close-in giant planets and the role of stellar multiplicity. The radial-velocity and photometric data used for this work are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A49">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A49</A> [less ▲]

Detailed reference viewed: 14 (1 ULg)