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See detailExploring the Antarctic soil metagenome as a source of novel cold-adapted enzymes and genetic mobile elements
Berlemont, Renaud ULg; Pipers; Delsaute, Maud ULg et al

in Revista Argentina de Microbiologia (2011)

Metagenomic library PP1 was obtained from Antarctic soil samples. Both functional and genotypic metagenomic screening were used for the isolation of novel cold-adapted enzymes with potential applications ... [more ▼]

Metagenomic library PP1 was obtained from Antarctic soil samples. Both functional and genotypic metagenomic screening were used for the isolation of novel cold-adapted enzymes with potential applications, and for the detection of genetic elements associated with gene mobilization, respectively. Fourteen lipase/esterase-, 14 amylase-, 3 protease-, and 11 cellulase-producing clones were detected by activity-driven screening, with apparent maximum activities around 35 °C for both amylolytic and lipolytic enzymes, and 35-55 °C for cellulases, as observed for other cold-adapted enzymes. However, the behavior of at least one of the studied cellulases is more compatible to that observed for mesophilic enzymes. These enzymes are usually still active at temperatures above 60 °C, probably resulting in a psychrotolerant behavior in Antarctic soils. Metagenomics allows to access novel genes encoding for enzymatic and biophysic properties from almost every environment with potential benefits for biotechnological and industrial applications. Only intI- and tnp-like genes were detected by PC R, encoding for proteins with 58-86%, and 58-73% amino acid identity with known entries, respectively. Two clones, BAC 27A-9 and BAC 14A-5, seem to present unique syntenic organizations, suggesting the occurrence of gene rearrangements that were probably due to evolutionary divergences within the genus or facilitated by the association with transposable elements. The evidence for genetic elements related to recruitment and mobilization of genes (transposons/integrons) in an extreme environment like Antarctica reinforces the hypothesis [less ▲]

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See detailExploring the cultural politics of labour in South China
Florence, Eric ULg

Scientific conference (2013, June 20)

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See detailExploring the Diversity of Fair Trade Social Enterprises
Huybrechts, Benjamin ULg; Defourny, Jacques ULg

E-print/Working paper (2010)

Fair trade (FT) organisations have been quite early taken as examples of social enterprises (SE) and have contributed to the shaping of the SE concept. The goal of this article is to examine more deeply ... [more ▼]

Fair trade (FT) organisations have been quite early taken as examples of social enterprises (SE) and have contributed to the shaping of the SE concept. The goal of this article is to examine more deeply, both at a conceptual and at an empirical level, to what extent FT organisations can be considered as social enterprises. First, we introduce different theoretical frameworks of SE and examine FT in the context of each of these frameworks. In a second step, we use an empirical study on fair trade social enterprises (FTSEs) across four European countries to illustrate and deepen the links between FT and SE, focusing on the goals and the governance structures of FTSEs. It appears that all FTSEs combine in some way economic, social and sometimes also political goals. FTSEs are thus in line with the "hybrid-goal" nature of SEs. FTSEs' governance is also quite specific and often innovative in terms of organisational architecture and stakeholders' involvement. Some FTSEs are closer to the European – participatory – approach of social enterprise, while others are closer to US – individual – approaches. Finally, the governance structures of FTSEs seem to reflect quite well their goal mix. This article provides a more solid basis for the often implicit link between FT and SE. Future researches could use our work to explore specific topics of the SE literature (e.g. stakeholders' involvement) in the context of FT. The FT example could also be used to examine further the shifting boundaries of the SE reality. The originality of this article is to apply the SE concept to a specific field and to show how, within this field, there is at the same time (1) a diversity of organisations, reflecting the diversity of SE approaches and (2) a range of specific features (especially in terms of goal mix and governance) distinguishing SEs from other types of organisations operating in the same field. [less ▲]

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See detailExploring the effect of action familiarity on SPTs recall performance in Alzheimer's disease
Lekeu, Françoise ULg; Van der Linden, Martial ULg; Moonen, Gustave ULg et al

in Journal of Clinical & Experimental Neuropsychology (2002), 24(8), 1057-1069

This study examined the performance of normal controls (NC) and Alzheimer's disease (AD) patients on free recall, semantic cued recall and object cued recall of both subject-performed tasks (SPTs) and ... [more ▼]

This study examined the performance of normal controls (NC) and Alzheimer's disease (AD) patients on free recall, semantic cued recall and object cued recall of both subject-performed tasks (SPTs) and verbal descriptions of actions, by controlling familiarity of actions associated to objects. The results showed that both groups performed better after SPT encoding than after verbal encoding. in all three types of recall. In addition, this SPT advantage was greater for AD patients than for NC in the object cued recall test, emphasizing AD patients' sensibility to the congruence of cues between encoding and retrieval conditions. Following verbal encoding. NC showed a better recall for less familiar actions than for highly familiar actions, whereas AD patients exhibited the opposite pattern. These results reflect that AD patients did not benefit from a distinctiveness effect at encoding for improving subsequent retrieval of verbal information, probably due to a reduced level of elaboration during encoding. However, there was no effect of action familiarity on recall performance by both groups following SPT encoding. These results suggest that memory for verbal actions and SPTs is governed by different principles. In addition. they demonstrate the robustness of the SPT effect in AD patients, who were able to improve memory performance in the SPT condition not only with highly familiar actions but also with less familiar actions. [less ▲]

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See detailExploring the Formation Pathways of DNA G-Quadruplex Architectures
Rosu, Frédéric ULg; Poncelet, Harmonie; Teulade-Fichou, Marie-Paule et al

Conference (2007, September 07)

Guanine-rich DNA strands can form the so-called G-quadruplex architectures due to the formation of quartets of guanines linked by 8 hydrogen bonds. G-quadruplexes are further stabilized by the inclusion ... [more ▼]

Guanine-rich DNA strands can form the so-called G-quadruplex architectures due to the formation of quartets of guanines linked by 8 hydrogen bonds. G-quadruplexes are further stabilized by the inclusion of cations between the G-quartets. The abundance of G-rich regions throughout the genome and their very presence in telomeric regions made G-quadruplexes interesting targets. NMR and crystallographic studies of G-quadruplex structures revealed amazing variety in the G-quadruplex topologies. The next challenge will be to understand the rules governing the formation of the various topologies, in order to predict relevant G-quadruplexes in the genome, and in order to act rationally on their formation or disruption. To date, only few experimental [1] or theoretical [2] studies have been devoted to investigating the mechanisms of G-quadruplex formation. We report here a detailed investigation of DNA G-quadruplex formation pathways using electrospray mass spectrometry (ESI-MS). The sequences TGnT (n = 3-6) were purchased from Eurogentec (Seraing, Beliugm). ESI-MS experiments were performed in the negative ion mode on a Q-TOF Ultima Global (Waters, Manchester, UK). The cation used was ammonium (up to 150 mM). Experiments were performed in the presence and absence of methanol (up to 20%) as co-solvent. ESI-MS allows counting both the number of strands and the number of cations in each intermediate. We could confirm the presence of transient dimer and trimer intermediates in low abundance. More unexpectedly, ESI-MS also reveals unambiguously the formation of pentamers which contain ammonium cations. The pentamers slowly convert into tetramers. Counting the number of included cations also revealed that, in the case of (TG6T)4, inclusion of four ammonium cations is fast, while the inclusion of the last ammonium ion is very slow. We also found that the addition of methanol (initially added to obtain higher ion intensities) significantly increases the rate of G-quadruplex formation. Finally, we also investigated the role of G-quadruplex ligands in the rate of formation of G-quadruplexes. We could classify the ligands according to their increase of G-quadruplex formation kinetics, and distinguish the intermediates. Interestingly, one ligand showed formation of a higher-order structure by bridging two G-quadruplexes. Acknowledgement: The authors thank the FRS-FNRS for their support. References: [1] J. Gros et al., Nucleic Acids Res., 2007, doi:10.1093/nar/gkm111. [2] R. Stefl et al., Biophys. J., 2003, 85(3), 1787-1804. [less ▲]

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See detailExploring the gravitationally lensed system HE 1104-1805: near-IR spectroscopy
Courbin, F.; Lidman, C.; Meylan, G. et al

in Astronomy and Astrophysics (2000), 360

A new technique for the spatial deconvolution of spectra is applied to near-IR (0.95-2.50 mum) NTT/SOFI spectra of the lensed, radio-quiet quasar HE 1104-1805. The continuum of the lensing galaxy is ... [more ▼]

A new technique for the spatial deconvolution of spectra is applied to near-IR (0.95-2.50 mum) NTT/SOFI spectra of the lensed, radio-quiet quasar HE 1104-1805. The continuum of the lensing galaxy is revealed between 1.5 mum and 2.5 mum. Although the spectrum does not show strong emission features, it is used in combination with previous optical and IR photometry to infer a plausible redshift in the range 0.8 < z < 1.2. Modeling of the system shows that the lens is complex, probably composed of the red galaxy seen between the quasar images and a more extended component associated with a galaxy cluster with fairly low velocity dispersion (~ 575 km s[SUP]-1[/SUP]). Unless more constrains can be put on the mass distribution of the cluster, e.g. from deep X-ray observations, HE 1104-1805 will not be a good system to determine H[SUB]0[/SUB]. We stress that multiply imaged quasars with known time delays may prove more useful as tools for detecting dark mass in distant lenses than for determining cosmological parameters. The spectra of the two lensed images of the source are of great interest. They show no trace of reddening at the redshift of the lens nor at the redshift of the source. This supports the hypothesis of an elliptical lens. Additionally, the difference between the spectrum of the brightest component and that of a scaled version of the faintest component is a featureless continuum. Broad and narrow emission lines, including the FeII features, are perfectly subtracted. The very good quality of our spectrum makes it possible to fit precisely the optical Fe II feature, taking into account the underlying continuum over a wide wavelength range. HE 1104-1805 can be classified as a weak Fe II emitter. Finally, the slope of the continuum in the brightest image is steeper than the continuum in the faintest image and supports the finding by Wisotzki et al. (1993) that the brightest image is microlensed. This is particularly interesting in view of the new source reconstruction methods from multiwavelength photometric monitoring. While HE 1104- 1805 does not seem the best target for determining cosmological parameters, it is probably the second most interesting object after Q 2237+0305 (the Einstein cross), in terms of microlensing. Based on observations collected with the ESO New Technology Telescope (program 61.B-0413) [less ▲]

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See detailExploring the Holocene through fossil cyanobacterial sequences from Antarctic lake sediments.
Fernandez Carazo, Rafael ULg; Waleron, Krzysztof; Hodgson, Dominic et al

Poster (2009, July 27)

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See detailExploring the L1-L2 relationship in the L2 acquisition of prosody
Rasier, Laurent ULg; Hiligsmann, Philippe

Conference (2009)

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See detailExploring the L1-L2 Relationship in the L2 Acquisition of Prosody
Rasier, Laurent ULg; Hiligsmann, Philippe

E-print/Working paper (2009)

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See detailExploring the magnetic topologies of cool stars
Morin, J.; Donati, J *-F; Petit, P. et al

in IAU Symposium Proceedings (2010, September 01)

Magnetic fields of cool stars can be directly investigated through the study of the Zeeman effect on photospheric spectral lines using several approaches. With spectroscopic measurement in unpolarised ... [more ▼]

Magnetic fields of cool stars can be directly investigated through the study of the Zeeman effect on photospheric spectral lines using several approaches. With spectroscopic measurement in unpolarised light, the total magnetic flux averaged over the stellar disc can be derived but very little information on the field geometry is available. Spectropolarimetry provides a complementary information on the large-scale component of the magnetic topology. With Zeeman-Doppler Imaging (ZDI), this information can be retrieved to produce a map of the vector magnetic field at the surface of the star, and in particular to assess the relative importance of the poloidal and toroidal components as well as the degree of axisymmetry of the field distribution. The development of high-performance spectropolarimeters associated with multi-lines techniques and ZDI allows us to explore magnetic topologies throughout the Hertzsprung-Russel diagram, on stars spanning a wide range of mass, age and rotation period. These observations bring novel constraints on magnetic field generation by dynamo effect in cool stars. In particular, the study of solar twins brings new insight on the impact of rotation on the solar dynamo, whereas the detection of strong and stable dipolar magnetic fields on fully convective stars questions the precise role of the tachocline in this process. [less ▲]

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See detailExploring the night sky with binoculars -- P. Moore
Manfroid, Jean ULg

in Ciel et Terre (1987), 103

Not Available

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See detailExploring the nucleon structure through GPDs and TDAs in hard exclusive processes
Pire, Bernard; Semenov-Tyan-Shanskiy, Kirill ULg; Szymanowski, Lech et al

Conference (2011)

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See detailExploring the origin of magnetic fields in massive stars: II. New magnetic field measurements in cluster and field stars
Hubrig, S.; Schoeller, M.; Ilyin, I. et al

in Astronomy and Astrophysics (2013), 551

Theories on the origin of magnetic fields in massive stars remain poorly developed, because the properties of their magnetic field as function of stellar parameters could not yet be investigated. To ... [more ▼]

Theories on the origin of magnetic fields in massive stars remain poorly developed, because the properties of their magnetic field as function of stellar parameters could not yet be investigated. To investigate whether magnetic fields in massive stars are ubiquitous or appear only in stars with a specific spectral classification, certain ages, or in a special environment, we acquired 67 new spectropolarimetric observations for 30 massive stars. Among the observed sample, roughly one third of the stars are probable members of clusters at different ages, whereas the remaining stars are field stars not known to belong to any cluster or association. Spectropolarimetric observations were obtained during four different nights using the low-resolution spectropolarimetric mode of FORS2 (FOcal Reducer low dispersion Spectrograph) mounted on the 8-m Antu telescope of the VLT. Furthermore, we present a number of follow-up observations carried out with the high-resolution spectropolarimeters SOFIN mounted at the Nordic Optical Telescope (NOT) and HARPS mounted at the ESO 3.6m between 2008 and 2011. To assess the membership in open clusters and associations, we used astrometric catalogues with the highest quality kinematic and photometric data currently available. The presence of a magnetic field is confirmed in nine stars previously observed with FORS1/2: HD36879, HD47839, CPD-282561, CPD-472963, HD93843, HD148937, HD149757, HD328856, and HD164794. New magnetic field detections at a significance level of at least 3sigma were achieved in five stars: HD92206c, HD93521, HD93632, CPD-468221, and HD157857. Among the stars with a detected magnetic field, five stars belong to open clusters with high membership probability. According to previous kinematic studies, five magnetic O-type stars in our sample are candidate runaway stars. [less ▲]

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See detailExploring the potential of crop specific green area index time series to improve yield estimation at regional scale
Duveiller, Gregory; de Wit, Allard; Kouadio, Amani Louis ULg et al

in Sobrino, J. A. (Ed.) Proceedings of the 3rd International Symposium on Recent Advances in Quantitative Remote Sensing (RAQRS'III) (2010)

Crop status, such as the Green Area Index (GAI), can be retrieved from satellite observations by modelling and inverting the radiative transfer within the canopy. Providing such information along the ... [more ▼]

Crop status, such as the Green Area Index (GAI), can be retrieved from satellite observations by modelling and inverting the radiative transfer within the canopy. Providing such information along the growing season can potentially improve crop growth modelling and yield estimation. However, such approaches have proven difficult to apply on coarse resolution satellite data due to the fragmented land cover in many parts of the World. Advances in operational crop mapping will sooner or later allow the production of crop maps relatively early in the crop growth season, thereby providing an opportunity to sample pixels from medium/coarse spatial resolution data with relatively high cover fraction of a particular crop type to derive crop specific GAI time series. This research explores how to use such time series derived from MODIS to produce indicators of crop yield using two approaches over part of Belgium. The first method consists in looking at metrics of the decreasing part of the GAI curves when senescence occurs. Such metrics, like the position of the inflexion point, have been shown to be significantly correlated to yield. The second approach is to optimize the WOFOST model used in the European Crop Growth Monitoring System (CGMS) based on the GAI time series. Results show that, although the optimized model shows considerably better performance than the model running on the default parameter, the model is sometimes outperformed by the simpler metric approach. In all cases, indicators including remote sensing information provide better estimates that the average yield of previous years. [less ▲]

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See detailExploring the relationship between new word learning and short-term memory for serial order recall, item recall, and item recognition
Majerus, Steve ULg; Poncelet, Martine ULg; Elsen, B. et al

in European Journal of Cognitive Psychology (2006), 18(6), 848-873

We reexplored the relationship between new word learning and verbal short-term memory (STM) capacities, by distinguishing STM for serial order information, item recall, and item recognition. STM ... [more ▼]

We reexplored the relationship between new word learning and verbal short-term memory (STM) capacities, by distinguishing STM for serial order information, item recall, and item recognition. STM capacities for order information were estimated via a serial order reconstruction task. A rhyme probe recognition task assessed STM for item recognition. Item recall capacities were derived from the proportion of item errors in an immediate serial recall task. In Experiment 1, strong correlations were observed between item recall and item recognition, but not between the item STM tasks and the serial order task, supporting recent theoretical positions that consider that STM for item and serial order rely on distinct capacities. Experiment 2 showed that only the serial order reconstruction task predicted independent variance in a paired associate word - nonword learning task. Our results suggest that STM capacities for serial order play a specific and causal role in learning new phonological information. [less ▲]

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See detailExploring the risk factors for Salmonella in the ten biggest Belgian pig slaughterhouses.
Delhalle, Laurent ULg; Desadeleer, L.; Bollaerts, K. et al

Poster (2007, May)

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See detailExploring the role of base words and suffixes in word and pseudoword processing: Evidence from young French readers
Quemart, Pauline ULg; Casalis, Séverine; Duncan, Lynne

in Scientific Studies of Reading (2012), (5), 424-442

Detailed reference viewed: 32 (2 ULg)