Last 7 days
Bookmark and Share    
See detailExtension patterns in pituitary macroadenomas and relation to T2-weightd signal on diagnostic MRI examinations
Potorac, I; Cattin, F; KREUTZ, Julie ULg et al

Poster (2014, June)

Detailed reference viewed: 11 (0 ULg)
Full Text
See detailLaTeX, un peu, beaucoup (4. Les "équations" et leurs styles)
Dupont, Pascal ULg

in Losanges (2014)

Detailed reference viewed: 11 (0 ULg)
See detailGCxGC-HRTOFMS a Powerful Tool in Separation Science
Focant, Jean-François ULg

Scientific conference (2014, June)

Detailed reference viewed: 17 (1 ULg)
Full Text
Peer Reviewed
See detailUsing intensive multiyear fish-pass monitoring to analyse seasonal upstream movement patterns of patrimonial holobiotic potomadromous fish species in a medium size river
Benitez, Jean-Philippe ULg; Nzau Matondo, Billy ULg; Dierckx, Arnaud ULg et al

in Proceedings of the 10th International Conference on Ecohydraulics (2014, June)

Belgian rivers are fragmented by numerous obstacles which considerably limit the free access of fish to functional habitats. Fish-passes are major tools used to increase stream continuity and improve ... [more ▼]

Belgian rivers are fragmented by numerous obstacles which considerably limit the free access of fish to functional habitats. Fish-passes are major tools used to increase stream continuity and improve connectivity in the upstream direction. Using two modern multispecies fish-passes, this study aims to investigate multiyear abundance of holobiotic potamodromous fish and their seasonal movement patterns in relation with environmental factors. The fish passes were monitored continuously during 5 and 7 years and are located in two Belgian streams: the (19.3m³.s-1) and the Berwinne (1.9m³.s-1). Results revealed the presence of 20 different fish species, 14 species in the Berwinne and 19 species in the occurrence, salmonids and cyprinids species were predominant. A great interspecific and intraspecific variability in capture periodicity and in terms of stimulation by combination of factor environmental was observed. This study highlights the complexity and the omnipresence of holobiotic potamodromous fish movements at different life stages, in medium size river and brings new information on fish passes efficiency and use by these poorly known species. [less ▲]

Detailed reference viewed: 12 (5 ULg)
Full Text
See detailThe cyclic behaviour of sand, from the Prevost model to offshore geotechnics
Cerfontaine, Benjamin ULg

Doctoral thesis (2014)

The main objective of this thesis is the studying of the cyclic behaviour of dense sand. Its centre of gravity is the implementation of a convenient constitutive law in the finite element code LAGAMINE ... [more ▼]

The main objective of this thesis is the studying of the cyclic behaviour of dense sand. Its centre of gravity is the implementation of a convenient constitutive law in the finite element code LAGAMINE. The first step consists in summarising the salient features of the cyclic behaviour of sand observed in laboratory tests. Undrained monotonic and cyclic experiments are addressed. The phase transformation line is a key parameter in the description of its behaviour. The plasticity effects in both loading and unloading, the progressive pore pressure accumulation coupled with the degradation of the stiffness of the soil are of uttermost importance in the cyclic behaviour. The Prevost model is adopted for its conceptual simplicity and its physically related parameters. The basic equations of the model are described and its variants are illustrated. Calibration of the required parameters is carried out by means of simplified routines implemented in Matlab. A unique set of parameters is determined for each soil at a given relative density. Monotonic experiments are well reproduced. The model also replicates satisfactorily the trend of cyclic experiments. An implicit scheme is embraced in order to implement the model in the finite element code LAGAMINE. The implicit Prager translation rule is adopted for that purpose. It is ensured the discrete formulation reproduces exactly the analytical model. Accuracy, efficiency and robustness of the model are addressed throughout triaxial and multi-axial numerical examples. A hydro-mechanical interface finite element is developed. It consists in a three-node 1D isoparametric element. It is able to reproduce fluid flows across and along the interface. The unsticking of both walls of the interface is coupled with a suction effect due to the filling of the vacuum created. The behaviour of the element is illustrated by simple 1D examples of transient consolidation of a soil column. A final application consists in the modelling of a suction caisson, part of a tripod structure for wind turbines. An axisymmetric representation of this foundation is carried out. It is assumed embedded into dense Lund sand described by the Prevost model. Monotonic and cyclic simulations are performed in both drained and partially drained conditions. The salient features of the resistance of such foundations are highlighted. Their partially drained behaviour strongly increases their transient resistance. A storm including an extreme event is employed to simulate a cyclic loading. A pseudo-random short signal and its sinusoidal equivalent representation finally lead to an identical vertical settlement. This is confirmed by a long duration storm. Finally, a cyclic diagram summarising the final settlement attained for combinations of average and cyclic vertical loads is elaborated. Keywords [less ▲]

Detailed reference viewed: 11 (4 ULg)
Full Text
Peer Reviewed
See detailEcologie, diversité spécifique et abondance des petits mammifères de la ville de Cotonou au Bénin (Afrique de l’Ouest)
Houèmènou, Gualbert; Kassa, B.; Libois, Roland ULg

in International Journal of Biological and Chemical Sciences (2014), 8(3), 1202-1213

L’étude de la diversité des petits mammifères de la ville de Cotonou (Bénin) selon les types de milieux (habités ou non) a été réalisée du 25 août 2004 au 25 mai 2005 avec interruptions. Les campagnes de ... [more ▼]

L’étude de la diversité des petits mammifères de la ville de Cotonou (Bénin) selon les types de milieux (habités ou non) a été réalisée du 25 août 2004 au 25 mai 2005 avec interruptions. Les campagnes de captures ont été effectuées. Au total, 348 petits mammifères ont été capturés pour un effort de piégeage de 2652 nuits-pièges et 11 espèces comprenant 3 espèces (Rattus rattus, Rattus norvegicus et Mus domesticus) cosmopolites représentant 25% du total et les espèces africaines (Crocidura olivieri, Crocidura sp., Arvicanthis niloticus,Cricetomys gambianus, Dasymys rufulus, Mastomys sp., Gerbilliscus kempi, Taterillus gracilis) représentant 75% du total, ont été inventoriées. La prépondérance de Rattus rattus dans les captures avec 59,8% de Mastomys sp. (13,5%) et de C. olivieri (8,6%) a été notée. Mus domesticus (0,29%), Arvicanthis niloticus (0,86%) et Crocidura sp. (0,86%) sont faiblement représentées. L’indice de diversité de Shannon est de 2,08 dans la ville de Cotonou, de 2,70 dans les milieux non habités et de 1,45 dans les milieux habités où l’on ne trouve quasiment que les rats et souris. Le domaine de l’aéroport (aéroport international de Cotonou) et quelques zones marécageuses, inaccessibles à la population, constituent des zones refuges où l’indice de diversité des petits mammifères est relativement élevé. [less ▲]

Detailed reference viewed: 6 (0 ULg)
Full Text
See detailRole of estradiol in the feminization of lordosis behavior in female mice
Trouillet, Anne-Charlotte ULg

Poster (2014, June)

The classic theory of mammalian brain and behavioral sexual differentiation holds that an organizational action of testosterone, secreted perinatally by the male’s testes, controls male-typical aspects of ... [more ▼]

The classic theory of mammalian brain and behavioral sexual differentiation holds that an organizational action of testosterone, secreted perinatally by the male’s testes, controls male-typical aspects of brain and behavioral development, whereas no active perinatal sex hormone signaling is required for female-typical differentiation. However, it has recently been shown using aromatase knock out (ArKO) mice, which are deprived of estradiol due to a targeted mutation in the aromatase gene, that estradiol may also actively contribute to the differentiation of female-typical aspects of behavior over a specific pre-pubertal period. Female ArKO mice showed significantly lower levels of lordosis behavior than wild type controls following adult ovariectomy and treatment with ovarian hormones. This deficit was restored by treating female ArKO mice with estradiol benzoate between postnatal days 15 and 25. However, the mechanism by which estradiol acts prepubertally in female mice to feminize lordosis behavior remains to be elucidated. Therefore, in a first attempt, we are determining which neuropeptides are in particularly sensitive to estradiol action over the prepubertal period. We will focus on neuropeptides which have been shown to be implicated in lordosis behavior. Studies by the group of Micevych have proposed an important role for NPY and beta-endorphin (B-END) neurons in the arcuate nucleus (ARC) in the estradiol-mediated activation of lordosis behavior in female rats. An in vitro study recently showed that kisspeptin directly activates ARC B-END neurons. This is particularly interesting since unpublished results from our laboratory showed that Kp neurons are directly involved in the expression of lordosis behavior. We are thus currently determining the expression of NPY, B-END, and kisspeptin in the ARC as well as μ-opioid receptors MORs in the MPN over the prepubertal period and their possible modulation by prepubertal estradiol treatment. [less ▲]

Peer Reviewed
See detailEstimated Subglottic Pressure Evaluation According to Vocal Pathology. Study on 418 Patients
Morsomme, Dominique ULg; Chareix, Hélène; FINCK, Camille ULg et al

Conference (2014, May 31)

Estimated subglottic pressure (ESGP) is part of the aerodynamic measurements included in the vocal profile. It is an indication of vocal effort and can guide the therapist in his clinical approach. We aim ... [more ▼]

Estimated subglottic pressure (ESGP) is part of the aerodynamic measurements included in the vocal profile. It is an indication of vocal effort and can guide the therapist in his clinical approach. We aim to examine the clinical interest of the ESGP by observing its values according to voice pathology, age, gender and sound pressure level. We also examine the relationships between PSGE, DSI and VHI. Method:The study includes 418 patients (M:118/W:300). Each patient’s file consists of VLS, acoustic, aerodynamic and perceptual measures. The ESGP was collected through the Phonatory Aerodynamic System Model 6600 (KayPentax). Patients produced 3 sequences of / ipipi / at low (IL), conversational (IC) and high (IH) intensity. Patients were grouped according to the ENT’s diagnosis. Results: Patients without vocal lesions (MTD) had a significantly lower ESGP compared to patients with nodules, polyps, inflammation, edema (IL, IC), cysts (IC) or scar (IC). Patients with vocal fold atrophy had a lower ESGP than those suffering from nodules and polyps at conversational and high intensity, but were not differentiated at low intensity. Amongst patients without lesions (MTD), a positive correlation appeared between ESGP and intensity; which was not the case for patients with lesions. At high intensity, men had a significantly higher ESGP than women. At low intensity, we noted a positive correlation between the VHI scores and ESGP levels. At low and conversational intensity, we observed a negative correlation between DSI and ESGP scores. Conclusion: This study highlights the importance of considering ESGP in the vocal profile. As expected, patients with vocal pathology produce high ESGP. However, the correlations between intensity and ESGP vary depending on the patient's pathology. In addition, ESPG values allow the clinician to distinguish MTD and healthy patients and thus could help the therapist in his clinical approach. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailFalsos positivos de C5-carnitina elevada en cribado neonatal: A que son debidos?
Yahyaoui, Raquel; Rueda; Dayaldasani, Anita et al

in Medicina Clinica (2014)

Detailed reference viewed: 12 (2 ULg)
Full Text
See detailWind Tunnel Testing of a VTOL MAV Propeller in Tilted Operating Mode
Theys, Bart; Dimitriadis, Grigorios ULg; Andrianne, Thomas ULg et al

in Proceedings of the 2014 International Conference on Unmanned Aircraft Systems (ICUAS 2014) (2014, May 30)

This paper presents experimental results of the full 3-axis force vector and 3-axis moment vector acting on a propeller, commonly used for a Vertical Take Off and Landing Micro Aerial Vehicle (VTOL MAV ... [more ▼]

This paper presents experimental results of the full 3-axis force vector and 3-axis moment vector acting on a propeller, commonly used for a Vertical Take Off and Landing Micro Aerial Vehicle (VTOL MAV). Measurements were carried out in a wind tunnel using a high resolution 6-axis force/moment sensor embedded in a customized test rig at several wind speeds, propeller rotational speeds and angles of the propeller shaft with respect to the air stream. Results show strong moments acting on the propeller in forward flight and unstable conditions in descending flight. Power calculations reveal a decrease in power consumption during slow forward flight and how motor efficiency can be maximized. [less ▲]

Detailed reference viewed: 3 (0 ULg)
Full Text
See detailBoard attributes and conditional conservatism: Evidence from French firms
Boussaid, Nabila ULg; Sougné, Danielle ULg; Hamza, Taher

Conference (2014, May 30)

Detailed reference viewed: 9 (1 ULg)
Full Text
See detailNumerical Investigation of Continuous Fiber Glass Drawing Process
Chouffart, Quentin ULg; Simon, Philippe; Terrapon, Vincent ULg

Conference (2014, May 30)

The manufacturing process of glass fibers used for the reinforcement of composite material consists in drawing a glass melt at high temperature through the bushing plate into fibers using a winder. This ... [more ▼]

The manufacturing process of glass fibers used for the reinforcement of composite material consists in drawing a glass melt at high temperature through the bushing plate into fibers using a winder. This process is sensitive to numerous disturbances that can cause the fiber to break during the drawing process. In order to understand the origin of these failures and improve the process efficiency, it is important to understand the physics of the forming fiber. We investigate here the underlying physics of the forming of a single fiber through numerical simulations. In particular, we focus on the region from the hole tips at the bushing plate to the glass transition point. The influence of key parameters (e.g. operating windows, and heat transfers mechanisms) on the fiber radius attenuation and the internal stresses is investigated through a sensitivity analysis. In addition, the impact of the temperature variations at the bushing plate is investigated. Finally, we show how the forming stress is influenced by these parameters. It is found that the internal stress can be minimizing by varying the operating windows. On the other hand, results also demonstrate that the heat pattern of the bushing plate is one of the most important causes for disturbance in the process. [less ▲]

Detailed reference viewed: 26 (4 ULg)
Full Text
See detailThe European Union election process : a way foward democracy
Michel, Quentin ULg

Scientific conference (2014, May 30)

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailUsing shear strain localisation to model the fracturing around gallery in unsaturated Callovo-Oxfordian claystone
Pardoen, Benoît ULg; Levasseur, Séverine ULg; Collin, Frédéric ULg

in 10th International Workshop on Bifurcation and Degradation in Geomaterials (2014, May 30)

Galleries drilling leads to damage propagation, fracturing and properties modifications in the surrounding medium. The prediction of the damaged zone behaviour is an important matter and needs to be ... [more ▼]

Galleries drilling leads to damage propagation, fracturing and properties modifications in the surrounding medium. The prediction of the damaged zone behaviour is an important matter and needs to be properly assessed. To do so the fractures can be modelled using shear strain localisation. The coupled local second gradient model is used under unsaturated conditions to correctly model the strain localisation behaviour. The permeability evolution and the rock desaturation due to air ventilation in galleries are considered. Finally, a hydro-mechanical modelling of a gallery excavation in Callovo-Oxfordian claystone is performed leading to a fairly good representation of the damaged zone. [less ▲]

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailToward a Characterization of Western Operatic Singing Voices
Larrouy, Pauline ULg; Magis, David ULg; Nowak, Marion et al

Poster (2014, May 29)

Objective: One can easily recognize the musical style of a singer by listening to his/her sung performance. Several acoustical parameters of the Western operatic singing technique have been studied ... [more ▼]

Objective: One can easily recognize the musical style of a singer by listening to his/her sung performance. Several acoustical parameters of the Western operatic singing technique have been studied. However, the number of parameters could be extended and the effect of melody on these parameters remains unclear. By observing the effects of melody and technique on acoustical and musical parameters of the singing voice, this study aims at further characterizing the Western operatic singing technique. Methods: Fifty professional singers performed two contrasting melodies (popular song and romantic melody) with two vocal techniques (with and without operatic singing technique). The common quality parameters (energy distribution, vibrato rate and extent), perturbation parameters (standard deviation of the fundamental frequency, signal-to-noise ratio, jitter and shimmer) and musical features (fundamental frequency of the starting note, average tempo, and sound pressure level) of the 200 sung performances were analyzed. Results: The results show that the choice of melody had a limited impact on the acoustical and musical parameters observed, whereas a particular vocal profile appeared depending on the vocal technique employed. By examining these parameters in a theoretical model, this study highlights the relevance of vibrato rate, sound level, energy distribution, fundamental frequency of the starting note and tempo in describing the Western operatic singing technique. Conclusions: This study confirms that vocal technique affects most of the parameters examined and that the effect of melody is limited. In addition, the observation of quality and musical parameters contributes to a better understanding of the operatic singing technique. Conversely, the perturbation parameters don’t seem to take part in the characterization of operatic singing voices. Although the suggested theoretical model needs to be further developed in future research, it already generates implications for research and teaching. [less ▲]

Detailed reference viewed: 15 (0 ULg)
See detailAbundance and variability of jellyfishes in the Bay of Calvi, Corsica
Collignon, Amandine ULg; Hecq, Jean-Henri ULg; Goffart, Anne ULg

Scientific conference (2014, May 29)

Detailed reference viewed: 35 (3 ULg)