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See detailMulti-frequency nonlinear energy transfer from linear oscillators to mdof essentially nonlinear attachments
Tsakirtzis, Stylianos; Kerschen, Gaëtan ULg; Panagopoulos, Panagiotis et al

in Journal of Sound & Vibration (2005), 285(1-2), 483-490

We report on multi-frequency energy transfer from a two-mode, initially excited linear system to a multi-degree-of-freedom (mdof) essentially nonlinear attachment. This occurs through simultaneous ... [more ▼]

We report on multi-frequency energy transfer from a two-mode, initially excited linear system to a multi-degree-of-freedom (mdof) essentially nonlinear attachment. This occurs through simultaneous resonance interactions of both linear modes with a set of nonlinear normal modes (NNMs) of the attachment, and is studied utilizing numerical wavelet transforms. The multi-frequency nonlinear energy transfer discussed herein differs from multi-frequency energy transfer caused by resonance capture cascading where sequential energy transfer from a set of linear modes to single-dof nonlinear attachments takes place. (c) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailEtude du classement par forêts aléatoires d'échantillons perturbés à forte structure d'interaction
Brostaux, Yves ULg

Doctoral thesis (2005)

Amongst classification methods, forests of decision trees (Random Forests, BREIMAN, 2001) are highly versatile concerning descriptive attributes' or target variable's nature and shape of the concept to ... [more ▼]

Amongst classification methods, forests of decision trees (Random Forests, BREIMAN, 2001) are highly versatile concerning descriptive attributes' or target variable's nature and shape of the concept to estimate. Their diffusion in agronomical sciences is slowed by a lack of information about their ability to learn models with high interaction structures using learning samples with few examples and affected by random noise and irrelevant attributes. This research aim to fill this gap by a systematic exploration of those factors' effects and of the parameters of the Random Forests method, which is done by computer simulations, taking as a reference the classification trees generated by Breiman's CART method (1984). Results show that generating random forests with a partially deterministic attributes selection and a forest size of at least 100 or 500 trees give the best prediction accuracy. Those random forests show a significant increase in prediction accuracy on CART trees, even for low learning sample size (50 examples). This advantage reduce with the global perturbation level (noise and irrelevant attributes) but increase with the learning sample size, as random forests aren't affected by the asymptotic limitation of the learning curve showed by CART method. [less ▲]

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See detailLiving radical polymerization under emulsion conditions
Szkurhan, K.; Chan-Seng, D.; Kasahara, T. et al

Poster (2005, July 03)

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See detailComet C/2005 K2 (LINEAR)
Jehin, Emmanuel ULg; Nielsen, O.; Bryssinck, E.

in International Astronomical Union Circulars [=IAUCs] (2005), 8566

IAUC 8566 available at Central Bureau for Astronomical Telegrams.

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See detailYin Yang 1 cooperates with activator protein 2 to stimulate ERBB2 gene expression in mammary cancer cells.
Begon, Dominique ULg; Delacroix, Laurence ULg; Vernimmen, Douglas et al

in Journal of Biological Chemistry (2005), 280(26), 24428-34

Overexpression of the ERBB2 oncogene is observed in about 30% of breast cancers and is generally correlated with a poor prognosis. Previous results from our and other laboratories indicated that elevated ... [more ▼]

Overexpression of the ERBB2 oncogene is observed in about 30% of breast cancers and is generally correlated with a poor prognosis. Previous results from our and other laboratories indicated that elevated transcriptional activity contributes significantly to the overexpression of ERBB2 mRNA in mammary adenocarcinoma cell lines. Activator protein 2 (AP-2) transcription factors account for this overexpression through two recognition sequences located 215 and 500 bp upstream from the transcription start site. Furthermore, AP-2 transcription factors are highly expressed in cancer cell lines overexpressing ERBB2. In this report, we examined the cooperative effect of Yin Yang 1 (YY1) on AP-2-induced activation of ERBB2 promoter activity. We detected high levels of YY1 transcription factor in mammary cancer cell lines. Notably, we showed that YY1 enhances AP-2alpha transcriptional activation of the ERBB2 promoter through an AP-2 site both in HepG2 and in HCT116 cells, whereas a carboxyl-terminal-truncated form of YY1 cannot. Moreover, we demonstrated the interaction between endogenous AP-2 and YY1 factors in the BT-474 mammary adenocarcinoma cell line. In addition, inhibition of endogenous YY1 protein by an antisense decreased the transcription of an AP-2-responsive ERBB2 reporter plasmid in BT-474 breast cancer cells. Finally, we detected in vivo AP-2 and YY1 occupancy of the ERBB2 proximal promoter in chromatin immunoprecipitation assays. Our data thus provide evidence that YY1 cooperates with AP-2 to stimulate ERBB2 promoter activity through the AP-2 binding sites. [less ▲]

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See detailCritical specific stream power in gravel-bed rivers
Petit, François ULg; Gob, Frédéric ULg; Houbrechts, Geoffrey ULg et al

in Geomorphology (2005), 69(1-4), 92-101

Experiments with marked pebbles were carried out on different sized rivers of the Belgian Ardenne (catchment areas varying from less than I km(2) to 2700 km(2)). Specific stream power required to cause ... [more ▼]

Experiments with marked pebbles were carried out on different sized rivers of the Belgian Ardenne (catchment areas varying from less than I km(2) to 2700 km(2)). Specific stream power required to cause bedload movement was evaluated and critical values were obtained. Three types of relationship between critical specific stream power (omega(0)) and grain size (D) were established. The values for coo in the largest river (the Ourthe) were the lowest and were close to the values obtained for mountainous rivers carrying large boulders. In medium sized rivers (catchment area between 40 and 500 km(2)), the critical unit stream power was higher. It is likely that it is due to the bedform's greater resistance. This resistance would use up some of the energy that can cause movement and transport of bedload. The amount of resistance of the bedform can be expressed as bedform shear stress (tau ''), determined by the relationship between grain shear stress (tau'-that determines movement and transport of the bedload) and the total shear stress (tau). This ratio varies between 0.4 and 0.5 in the medium sized rivers, compared to 0.7 in the Ourthe. In headwater streams (less than 20 km(2)), there is greater loss of energy due to bedform resistance (tau'/tau < 0.3). Critical specific stream power is higher in this third type of river than in the other two. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailSurface effects of active folding, illustrated with examples from the TianShan
Hubert, Aurelia ULg; Suppe, J; Gonzalez-Mieres, J. et al

Conference (2005, July)

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See detailExperience from a large multi-centre expanded access programme (EAP) with gefitinib ('Iressa', ZD1839) as monotherapy in advanced non-small cell lung cancer (NSCLC)
van Puijenbroek, R.; Bosquee, Léon ULg; Tits, G. et al

in Lung Cancer (2005, July), 49(Suppl. 2), 273

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See detailTopology Discovery Using an Address Prefix Based Stopping Rule
Donnet, Benoît ULg; Friedman, Timur

in EUNICE Workshop (2005, July)

Recently, a first step towards a highly distributed IP-level topology discovery tool has been made with the introduction of the Doubletree algorithm. Doubletree is an efficient cooperative algorithm that ... [more ▼]

Recently, a first step towards a highly distributed IP-level topology discovery tool has been made with the introduction of the Doubletree algorithm. Doubletree is an efficient cooperative algorithm that allows the discovery of a large portion of nodes and links in the network while strongly reducing probing redundancy on nodes and destinations as well as the amount of probes sent. In this paper, we propose to reduce more strongly the load on destinations and, more essentially, the communication cost required for the cooperation by introducing a probing stopping rule based on CIDR address prefixes. [less ▲]

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See detailLow-Molecular-Weight Protein Tyrosine Phosphatases of Bacillus subtilis
Musumeci, Lucia ULg; Bongiorni, Cristina; Tautz, Lutz et al

in Journal of Bacteriology (2005), 187(14), 4945-4956

In gram-negative organisms, enzymes belonging to the low-molecular-weight protein tyrosine phosphatase (LMPTP) family are involved in the regulation of important physiological functions, including stress ... [more ▼]

In gram-negative organisms, enzymes belonging to the low-molecular-weight protein tyrosine phosphatase (LMPTP) family are involved in the regulation of important physiological functions, including stress resistance and synthesis of the polysaccharide capsule. LMPTPs have been identified also in gram-positive bacteria, but their functions in these organisms are presently unknown. We cloned two putative LMPTPs from Bacillus subtilis, YfkJ and YwlE, which are highly similar to each other in primary structure as well as to LMPTPs from gram-negative bacteria. When purified from overexpressing Escherichia coli strains, both enzymes were able to dephosphorylate p-nitrophenyl-phosphate and phosphotyrosine-containing substrates in vitro but showed significant differences in kinetic parameters and sensitivity to inhibitors. Transcriptional analyses showed that yfkJ was transcribed at a low level throughout the growth cycle and underwent a σB-dependent transcriptional upregulation in response to ethanol stress. The transcription of ywlE was growth dependent but stress insensitive. Genomic deletion of each phosphatase-encoding gene led to a phenotype of reduced bacterial resistance to ethanol stress, which was more marked in the ywlE deletion strain. Our study suggests that YfkJ and YwlE play roles in B. subtilis stress resistance. [less ▲]

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See detailThe antiangiogenic factor, 16-kDa human prolactin, induces endothelial cell cycle arrest by acting at both the G(0)-G(1) and the G(2)-M phases
Tabruyn, Sébastien ULg; Nguyen, Ngoc-Quynh-Nhu ULg; Cornet, Anne ULg et al

in Molecular Endocrinology (2005), 19(7), 1932-1942

The 16-kDa N-terminal fragment of human prolactin (16K hPRL) is a potent antiangiogenic factor that has been shown to prevent tumor growth in a xenograph mouse model. In this paper we first demonstrate ... [more ▼]

The 16-kDa N-terminal fragment of human prolactin (16K hPRL) is a potent antiangiogenic factor that has been shown to prevent tumor growth in a xenograph mouse model. In this paper we first demonstrate that 16K hPRL inhibits serum-induced DNA synthesis in adult bovine aortic endothelial cells. This inhibition is associated with cell cycle arrest at both the G(0)-G(1) and the G(2)-M phase. Western blot analysis revealed that 16K hPRL strongly decreases levels of cyclin D1 and cyclin B1, but not cyclin E. The effect on cyclin D1 is at least partially transcriptional, because treatment with 16K hPRL both reduces the cyclin D1 mRNA level and down-regulates cyclin D1 promoter activity. This regulation may be due to inhibition of the MAPK pathway, but it is independent of the glycogen synthase kinase-3 beta pathway. Lastly, 16K hPRL induces the expression of negative cell cycle regulators, the cyclin-dependent kinase inhibitors p21(cip1) and p27(kip1). In summary, 16K hPRL inhibits serum-induced proliferation of endothelial cells through combined effects on positive and negative regulators of cell cycle progression. [less ▲]

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See detailOptimization of Surface Utilization Using Heuristic Approaches
Langer, Yves; Bay, Maud ULg; Crama, Yves ULg et al

in Ship Technology Research = Schiffstechnik (2005), 52(3), 141-147

We present a scheduling problem that arises in factories producing large building blocks. This is a three dimensional bin-packing problem with two spatial dimensions and a time dimension. We propose an ... [more ▼]

We present a scheduling problem that arises in factories producing large building blocks. This is a three dimensional bin-packing problem with two spatial dimensions and a time dimension. We propose an algorithm based on the guided local search heuristic of Faroe and al. (Informs Journal of Computing,vol.15, 2003). The algorithm is especially developped to consider real-life issues. Finally the algorithm is applied on an industrial problem and shows excellent performances in speed and quality of the solution. [less ▲]

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See detailEfficacy and morbidity of a novel induction treatment for locally advanced NSCLC
Bosquee, Léon ULg; Rinken, Françoise ULg; Bustin, F. et al

in Lung Cancer (2005, July), 49(Suppl. 2), 78

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See detailDétestation de la mélancolie. Note sur la mémoire et sur l'oubli
Havelange, Carl ULg

in vu d'ici (2005), 19

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See detailCareer end for teachers: Towards a better understanding of stress and early retirement
Hansez, Isabelle ULg; Bertrand, Françoise ULg; De Keyser, Véronique ULg et al

in Travail Humain (Le) (2005), 68(3), 193-223

An increasing number of teachers decide to resign before legal retirement age, leading to significant shortages within the profession. A survey was conducted among teachers working in the city of Liege ... [more ▼]

An increasing number of teachers decide to resign before legal retirement age, leading to significant shortages within the profession. A survey was conducted among teachers working in the city of Liege, Belgium. This aimed to determine what led them to withdraw from their jobs and the degree to which stress contributed to their decisions. Various adjustments were made in favour of elderly workers, such as working time and training. The question of whether these are sufficient to keep them motivated in their job was raised. A questionnaire was developed to try and identify the reasons why teachers resign, their motivations for staying in the job and their expectations in terms of career-end adjustments. The key concepts included in this tool were personal factors, job-related factors (i.e. working conditions, organizational and structural changes and job recognition) and employment-related factors. This questionnaire was combined with a subjective stress measure (MSP-A, Lemyre [less ▲]

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See detailAn XMM-Newton observation of the multiple system HD 167971 (O5-8V+O5-8V+(O81)) and the young open cluster NGC6604
De Becker, Michaël ULg; Rauw, Grégor ULg; Blomme, Ronny et al

in Astronomy and Astrophysics (2005), 437(3), 1029-1046

We discuss the results of two XMM-Newton observations of the open cluster NGC 6604 obtained in April and September 2002. We concentrate mainly on the multiple system HD 167971 (O5- 8V + O5- 8V + (O8I ... [more ▼]

We discuss the results of two XMM-Newton observations of the open cluster NGC 6604 obtained in April and September 2002. We concentrate mainly on the multiple system HD 167971 (O5- 8V + O5- 8V + (O8I)). The soft part of the EPIC spectrum of this system is thermal with typical temperatures of about 2 x 106 to 9 x 106 K. The nature ( thermal vs. non-thermal) of the hard part of the spectrum is not unambiguously revealed by our data. If the emission is thermal, the high temperature of the plasma (similar to 2.3 x 10(7) to 4.6 x 10(7) K) would be typical of what should be expected from a wind-wind interaction zone within a long period binary system. This emission could arise from an interaction between the combined winds of the O5- 8V + O5- 8V close binary system and that of the more distant O8I companion. Assuming instead that the hard part of the spectrum is non-thermal, the photon index would be rather steep (similar to 3). Moreover, a marginal variability between our two XMM-Newton pointings could be attributed to an eclipse of the O5 - 8V + O5 - 8V system. The overall X-ray luminosity points to a significant X-ray luminosity excess of about a factor 4 possibly due to colliding winds. Considering HD 167971 along with several recent X-ray and radio observations, we propose that the simultaneous observation of non-thermal radiation in the X-ray (below 10.0 keV) and radio domains appears rather unlikely. Our investigation of our XMM-Newton data of NGC 6604 reveals a rather sparse distribution of X-ray emitters. Including the two bright non-thermal radio emitters HD 168112 and HD 167971, we present a list of 31 X-ray sources along with the results of the cross-correlation with optical and infrared catalogues. A more complete spectral analysis is presented for the brightest X-ray sources. Some of the members of NGC 6604 present some characteristics suggesting they may be pre-main sequence star candidates. [less ▲]

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See detailInvolvement of both prefrontal and inferior parietal cortex in dual-task performance
Collette, Fabienne ULg; Olivier, L.; Van der Linden, Martial ULg et al

in Cognitive Brain Research (2005), 24(2), 237-251

This PET study explored the neural substrate of both dual-task management and integration task using single tasks that are known not to evoke any prefrontal activation. The paradigm included two simple ... [more ▼]

This PET study explored the neural substrate of both dual-task management and integration task using single tasks that are known not to evoke any prefrontal activation. The paradigm included two simple (visual and auditory) discrimination tasks, a dual task and an integration task (requiring simultaneous visual and auditory discrimination), and baseline tasks (passive viewing and hearing). Data were analyzed using SPM99. As predicted, the comparison of each single task to the baseline task showed no activity in prefrontal areas. The comparison of the dual task to the single tasks demonstrated left-sided foci of activity in the frontal gyrus (BA 9/46, BA 10/47 and BA 6), inferior parietal gyrus (BA 40), and cerebellum. By reference to previous neuroimaging studies, BA 9/46 was associated with the coordinated manipulation of simultaneously presented information, BA 10/47 with selection processes, BA 6 with articulatory rehearsal, and BA 40 with attentional shifting. Globally similar regions were found for the integration task, except that the inferior parietal gyrus was not recruited. These results confirm the hypothesis that the left prefrontal cortex is implicated in dual-task performance. Moreover, the involvement of a parietal area in the dual task is in keeping with the hypothesis that a parieto-frontal network sustains executive functioning. [less ▲]

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See detailThe CINEMA Project: A Video-Based Human-Computer Interaction System for Audio-Visual Immersion
Dardenne, Renaud; Embrechts, Jean-Jacques ULg; Van Droogenbroeck, Marc ULg et al

in ERCIM News (2005), 62

Numerous studies are currently focusing on the modelling of humans and their behavior in 3D environments. The CINEMA project has similar goals but differentiates itself by aiming at enhanced interactions ... [more ▼]

Numerous studies are currently focusing on the modelling of humans and their behavior in 3D environments. The CINEMA project has similar goals but differentiates itself by aiming at enhanced interactions, the creation of mixed reality, and the creation of interactive and reactive acoustical environments. Part of the project consists in gesture recognition of a user, who is given the real-time control of auralization and audio spatialization processes. [less ▲]

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