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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 and 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 effects of seismicity on landslides and catchment sediment yield: An Italian case study
Vanmaercke, Matthias ULg; Ardizzone, F.; Rossi, M. et al

in Geomorphology (2017), 278

Recent studies showed that contemporary average catchment sediment yields (SY, [t km− 2 y− 1]) at regional and continental scales are often strongly correlated to spatial patterns of seismic activity ... [more ▼]

Recent studies showed that contemporary average catchment sediment yields (SY, [t km− 2 y− 1]) at regional and continental scales are often strongly correlated to spatial patterns of seismic activity. Nonetheless, we currently have little insights into the mechanisms that explain these correlations. We investigated how spatial patterns of SY in Italy are linked to patterns of seismic activity. For a dataset of 103 Italian catchments with average SY measured over a period of years to decades, we extracted tectonic and none-tectonic variables that potentially explain observed differences in SY. These include proxies for vertical uplift rates and cumulative seismic moments (CSM) associated with historic earthquakes of different ranges of magnitude. Results showed that also across Italy, SY is significantly correlated to seismicity. However, SY showed much stronger correlations with proxies of seismicity relating to small but frequent earthquakes (2 ≤ Mw < 4) than with proxies relating to tectonic uplift or large, potentially landslide-triggering earthquakes (Mw ≥ 4). Analyses of a dataset of about 500,000 landslides across Italy showed very comparable trends: spatial patterns of landslides within similar lithological units generally show a significant positive correlation with CSM of weak but frequent seismicity and generally not with CSM of large earthquakes. These results suggest that, on a decadal time scale and at a regional/continental spatial scale, frequent but relatively weak seismicity may exert a more important geomorphic impact than large earthquake events or tectonic uplift. © 2016 Elsevier B.V. [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 Fundamentals of Microreactor Technology with Multidisciplinary Lab Experiments Combining the Synthesis and Characterization of Inorganic Nanoparticles
Emmanuel, Noémie ULg; Emonds-Alt, Gauthier ULg; Lismont, Marjorie et al

in Journal of Chemical Education (2017)

Multidisciplinary lab experiments combining microfluidics, nanoparticle synthesis and characterization are presented. These experiments rely on the implementation of affordable yet efficient microfluidic ... [more ▼]

Multidisciplinary lab experiments combining microfluidics, nanoparticle synthesis and characterization are presented. These experiments rely on the implementation of affordable yet efficient microfluidic setups based on PFA capillary coils and standard HPLC connectors in upper undergraduate chemistry labs. Fundamental principles and concepts, as well as practical tips for the rapid deployment of microfluidics are presented. In-line membrane separation, segmented-flow regime, high temperature experiments, and in-line analytical techniques are illustrated with the preparation of inorganic nanoparticles (silver, gold, cadmium selenide or telluride) in microreactors. Besides microfluidics, analytical techniques for nanoparticle analysis are also illustrated. [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 Interest in and the Usage of the Internet Among Patients Eligible for Osteoporosis Screening.
Slomian, Justine ULg; Reginster, Jean-Yves ULg; Gaspard, Ulysse ULg et al

in Calcified tissue international (2015), 96

The aim of this study was to evaluate the interest in the Internet and its usage for health-related issues among people eligible for osteoporosis screening. Self-administered questionnaires have been ... [more ▼]

The aim of this study was to evaluate the interest in the Internet and its usage for health-related issues among people eligible for osteoporosis screening. Self-administered questionnaires have been distributed to subjects who were screened for osteoporosis and to menopausal women. 177 patients have responded to the survey (64.5 +/- 10.1 years, 88.1 % of women). There are 78.5 % of Internet users. Among them, 67.2 % said searching information about their health and 74.5 % said using the Internet for this purpose. All respondents attributed an average score, out of 10, of 5.7 +/- 2.3 regarding the reliability of information that they could find on the Internet. The use of the Internet differs significantly depending on age: those who use the Internet are younger (62.1 +/- 8.91 years) than those who do not use it (73.3 +/- 9.42 years). The socioeconomic status also has an impact on the Internet use: Internet users have a higher education, are more professionally active and have a higher net monthly household income compared to the group of non-users. Even if age and socioeconomic status appear to be determining factors in the use of the Internet for the search of health information in patients eligible for osteoporosis screening, almost 75 % of the study population use the Internet for this purpose. Action to promote health through an Internet platform must therefore take these parameters into account. [less ▲]

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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 major depletions of conodont diversity during the Triassic
Martínez-Pérez, Carlos; Cascales - Miñana, Borja ULg; Plasencia, Pablo et al

in Historical Biology (2015), 27(5), 503-507

In this paper, we show that the Triassic fossil record reflects just two great depletions of conodont diversity before the Rhaetian, which occurred in the Smithian (Olenekian, Early Triassic) and in the ... [more ▼]

In this paper, we show that the Triassic fossil record reflects just two great depletions of conodont diversity before the Rhaetian, which occurred in the Smithian (Olenekian, Early Triassic) and in the Julian (Carnian, Late Triassic). By exploring this context, our results highlighted that they respond to different origination-extinction dynamics. Thus, while the Smithian diversity depletion can be interpreted as a consequence of elevated extinction, the Julian diversity depletion was triggered by fluctuations in origination regime. This evidence suggests that, despite the role of extinction on diversity losses, conodonts suffered crucial changes on the origination regimes during the Late Triassic which triggered these events. Notwithstanding, our results indicate that the end-Triassic diversity depletion of conodonts was produced by background extinction levels in a context of lower origination. This suggests that several biological factors, rather than a unique, environmental and/or cyclic cause, could have influenced the evolutionary history of conodonts during the Triassic. © 2014 © 2014 Taylor & Francis. [less ▲]

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See detailExploring the multiple functions of sleeping sites in Northern Pigtail macaques (Macaca leonina)
Jose Dominguez, Juan Manuel; Asensio, Norberto; Garcia Garcia, Carmen J et al

in International Journal of Primatology (2015), 36(4), 948-966

the seasonal variation, maximizing daily activities. Overall, predator avoidance and food efficiency were the main factors influencing the selection of sleeping sites. Our observations differ from those ... [more ▼]

the seasonal variation, maximizing daily activities. Overall, predator avoidance and food efficiency were the main factors influencing the selection of sleeping sites. Our observations differ from those found in a semiprovisioned group inhabiting the same Abstract Sleeping site selection in nonhuman primates may respond to various eco- logical factors, including predation avoidance, range defense, and foraging efficiency. We studied the sleeping sites used by a group of northern pigtailed macaques on 124 nights to test these hypotheses. The macaques used 57 different sleeping sites, of which 33 were used only once. They rarely used the same site on consecutive nights. These selection patterns are consistent with an antipredatory function, but may also be related to an antipathogenic strategy. Sleeping sites were located principally in the most heavily used areas of the home range and were generally away from areas of intergroup encounters. However, some of the most heavily used sleeping sites were in the area where intergroup encounters occurred, and intergroup encounters at sleeping sites always showed high levels of agonism, indicating possible intergroup competition over sleeping sites. On 77 % of nights, the study group selected the sleeping site nearest to either the last feeding area that day or to the first feeding area used the next morning, suggesting a foraging efficiency strategy. The mean distances from the sleeping site to the last and first feeding area were 227 m and 127 m, respectively, suggesting a multiple central place foraging strategy. The macaques entered sleeping sites a mean of 27 min before sunset and left 24 min after sunrise, and these times varied in line withstudy site, which used fewer sleeping sites and reused them much more often. This difference highlights the impact anthropogenic activities may have on sleeping site selection and the flexibility of sleeping patterns in a single species. Such flexibility may have helped the tree-to-ground evolutionary transition of sleep habits in primates [less ▲]

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

in Ciel et Terre (1987), 103

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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 Parsing of Dynamic Action in Checking Proneness
Belayachi, Sanaa ULg; Van der Linden, Martial ULg

in Behaviour Change (2015), 32(2), 93-103

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See detailExploring the plant diversity through time: inference and bias
Cascales - Miñana, Borja ULg; Cleal, Christopher J.

Conference (2014, November)

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