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See detailIs Contact Between Conspecifics Involved in the Cohesion of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) Aggregations?
Durieux, Delphine ULg; Fassotte, Bérénice ULg; Fischer, Christophe ULg et al

in Journal of Insect Behavior (2014), 27(1), 1-13

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas), exhibits a gregarious behavior during unfavorable winter conditions. Although this behavior is currently described as a phenomenon occurring ... [more ▼]

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas), exhibits a gregarious behavior during unfavorable winter conditions. Although this behavior is currently described as a phenomenon occurring only during winter, aggregations can also be observed outside overwintering conditions. However, the substrate markings previously highlighted as being involved in the wintry aggregation of this exotic species do not seem to be used by non-overwintering individuals to aggregate. This fact suggests then that other cues are responsible for the induction of this behavior. In this work, we have tested the hypothesis that direct contact between non-overwintering individuals stimulates the establishment of clusters. Binary choice experiments highlighted the involvement of elytral cuticular compounds in this phenomenon. Chromatographic analyses showed that the active extracts contained mainly hydrocarbons, including saturated, mono-unsaturated, and di-unsaturated homologues. Physical contact also seems to be involved in the non-overwintering aggregative behavior of H. axyridis, but to a lesser extent than these natural compounds. These findings could eventually be used to develop new control methods of these pest populations and so, reduce the adverse impacts it causes on biodiversity. [less ▲]

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See detailLaTeX, un peu, beaucoup (4. Les "équations" et leurs styles)
Dupont, Pascal ULg

in Losanges (2014)

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See detailGCxGC-HRTOFMS a Powerful Tool in Separation Science
Focant, Jean-François ULg

Scientific conference (2014, June)

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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 ▲]

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See detailINVESTIGATION OF TWO IMPROVED TRADITIONAL MEDICINES: DEVELOPMENT AND VALIDATION OF A LC-UV METHOD FOR THE DOSAGE OF A TRACER COMPOUND
Tshisekedi Tshibangu, Pascal; Kalenda Dibungi, Pascal; Rozet, Eric ULg et al

Poster (2014, June)

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See detailAfrique: le péril des migrations climatiques
Ozer, Pierre ULg; Gemenne, François ULg

Article for general public (2014)

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See detailNouakchott: les pieds dans l'eau
Ozer, Pierre ULg

Article for general public (2014)

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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 ▲]

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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)

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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 ▲]

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See detailBoard attributes and conditional conservatism: Evidence from French firms
Boussaid, Nabila ULg; Sougné, Danielle ULg; Hamza, Taher

Conference (2014, May 30)

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See detailEffect of concentration in Ge-Te liquids: A combined density functional and neutron scattering study
Micoulaut, Matthieu; Coulet, M.V.; Piarristeguy, A. et al

in Physical Review. B : Solid State (2014), 89(17), 174205

The structural properties of three compositions of Ge-Te liquids (Ge10Te90, Ge15Te85, Ge20Te80) are studied from a combination of density functional based molecular dynamics simulations and neutron ... [more ▼]

The structural properties of three compositions of Ge-Te liquids (Ge10Te90, Ge15Te85, Ge20Te80) are studied from a combination of density functional based molecular dynamics simulations and neutron scattering experiments. We investigate structural properties including structure factors, pair distribution functions, angular distributions, coordination numbers, neighbor distributions and compare our results with experimental findings. Most noticeable is the good agreement found in the reproduction of the structure in real and reciprocal space, resulting from the incorporation of dispersion forces in the simulation. This leads to Ge and Te coordination numbers which are lower than in previous studies and which can now be followed with temperature, while also strongly depending on the chosen cutoff distance. Results show a gradual conversion of higher coordinated species (TeIV, GeV) into lower coordinated ones at lower temperature, while leaving anticipated coordinations from the octet rule (TeII and GeIV) nearly unchanged. Structural correlations are characterized as a function of temperature and composition. The vibrational density of states is also measured from inelastic neutron scattering for different compositions and temperatures, and compared to the simulated counterpart which exhibits a reasonable agreement at low frequency. [less ▲]

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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 ▲]

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See detailThe European Union election process : a way foward democracy
Michel, Quentin ULg

Scientific conference (2014, May 30)

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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 ▲]

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