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Peer Reviewed
See detailIntegrating lexis, gesture and discourse in spatial descriptions
Lemmens, Maarten; Perrez, Julien ULg

Conference (2014, October 01)

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See detailThe 2.35 year itch of Cygnus OB2 #9. III. X-ray and radio emission analysis based on 3D hydrodynamical modelling
Parkin, E. R.; Pittard, J. M.; Nazé, Yaël ULg et al

in Astronomy and Astrophysics (2014), 570

Context. The wind-wind collision in a massive star binary system leads to the generation of high temperature shocks that emit at X-ray wavelengths and, if particle acceleration is effective, may exhibit ... [more ▼]

Context. The wind-wind collision in a massive star binary system leads to the generation of high temperature shocks that emit at X-ray wavelengths and, if particle acceleration is effective, may exhibit non-thermal radio emission. Cyg OB2#9 is one of a small number of massive star binary systems in this class. <BR /> Aims: X-ray and radio data recently acquired as part of a project to study Cyg OB2#9 are used to constrain physical models of the binary system, providing in-depth knowledge about the wind-wind collision and the thermal, and non-thermal, emission arising from the shocks. <BR /> Methods: We use a 3D, adaptive mesh refinement simulation (including wind acceleration, radiative cooling, and the orbital motion of the stars) to model the gas dynamics of the wind-wind collision. The simulation output is used as the basis for radiative transfer calculations considering the thermal X-ray emission and the thermal/non-thermal radio emission. <BR /> Results: The flow dynamics in the simulation show that wind acceleration (between the stars) is inhibited at all orbital phases by the opposing star's radiation field, reducing pre-shock velocities below terminal velocities. To obtain good agreement with the X-ray observations, our initial mass-loss rate estimates require a down-shift by a factor of ˜7.7 to 6.5 × 10[SUP]-7[/SUP] M[SUB]⊙[/SUB] yr[SUP]-1[/SUP] and 7.5 × 10[SUP]-7[/SUP] M[SUB]⊙[/SUB] yr[SUP]-1[/SUP] for the primary and secondary star, respectively. Furthermore, the low gas densities and high shock velocities in Cyg OB2 #9 are suggestive of unequal electron and ion temperatures, and the X-ray analysis indicates that an immediately post-shock electron-ion temperature ratio of ≃0.1 is also required. The radio emission is dominated by non-thermal synchrotron emission. A parameter space exploration provides evidence against models assuming equipartition between magnetic and relativistic energy densities. However, fits of comparable quality can be attained with models having stark contrasts in the ratio of magnetic-to-relativistic energy densities. Both X-ray and radio lightcurves are largely insensitive to viewing angle. The variations in X-ray emission with orbital phase can be traced back to an inverse relation with binary separation and pre-shock velocity. The radio emission also scales with pre-shock velocity and binary separation, but to positive powers (i.e. not inversely). The radio models also reveal a subtle effect whereby inverse Compton cooling leads to an increase in emissivity as a result of the synchrotron characteristic frequency being significantly reduced. Finally, using the results of the radio analysis, we estimate the surface magnetic field strengths to be ≈0.3 - 52G. [less ▲]

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See detailNouveautés en allergologie. L'allergie moléculaire.
GADISSEUR, Romy ULg

Conference (2014, October 01)

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See detailMicrocrystalline cellulose, a direct compression binder in a quality by design environment—A review
Thoorens, Grégory; Krier, Fabrice ULg; Leclercq, Bruno et al

in International Journal of Pharmaceutics (2014), 473(1-2), 64-72

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See detailLiège. Où s’amorce le nouveau modèle économique wallon ? Où s’échoue le vieux modèle politique wallon ?
Artige, Lionel ULg

Conference given outside the academic context (2014)

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See detailLes châteaux industriels dans le bassin liégeois : typologie et étude de cas
Destatte, Julien ULg; Peters, Arnaud ULg; Van Velthem, Lionel

Conference (2014, October 01)

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See detailPreliminary data from the Liège Screening programme suggests the reported decline in AAA prevalence is not global
Makrygiannis, Georgios ULg; EL HACHEMI, Mounia ULg; Labalue, Philippe et al

in Aorta (2014, October 01), 2(5), 212253

Background: Population based studies have shown evident benefit in terms of mortality from screening for Abdominal Aortic Aneurysm (AAA) among men aged over 65. However, recent studies from USA, UK and ... [more ▼]

Background: Population based studies have shown evident benefit in terms of mortality from screening for Abdominal Aortic Aneurysm (AAA) among men aged over 65. However, recent studies from USA, UK and Sweden suggest a decrease in the prevalence of AAA in the general population. Whether these findings are generalizable for the rest of Europe is unknown. Thus we decided to set up a screening program in order to detect AAA in Liege, Belgium. Material and Methods: During our ongoing study, over a first 3-month period, abdominal aortic ultrasound was performed on 541 participants, (198 women 343 men) to measure the maximal suprarenal and infrarenal aortic outer-outer diameter as well as the maximal diameter of the common iliac arteries. Moreover, we have measured arm and ankle blood pressure in each subject and the clinical characteristics of the patients, were collected. Results: The overall AAA prevalence was 4.62% (n = 25). In female participants aged ≥ 74 years the AAA prevalence amounted 1.01 %. While in male patients aged ≥ 65 years, it rose to 6.71%. Statistical analysis showed that male gender, aging, history of ischemic heart diseases, hyperlipidemia and varicose veins were significantly associated with AAA. Conclusion: Despite a reported declining prevalence of AAA in some recent population-based studies, we found that the prevalence of AAA in Liège population remains high in men aged 65 years or more. The prevalence of AAA seems to vary in different geographical regions. However, we need a larger sample to confirm our preliminary findings. [less ▲]

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See detailMulticenter implementation of geriatric assessment in Belgian patients with cancer: A survey on treating physicians' general experiences and expectations.
Kenis, Cindy; Kenis, Cindy; Heeren, Pieter et al

in Journal of geriatric oncology (2014), 5(4), 431-438

OBJECTIVES: The aim of this study is to identify treating physicians' general experiences and expectations regarding geriatric assessment (GA) in older patients with cancer. MATERIALS AND METHODS: A ... [more ▼]

OBJECTIVES: The aim of this study is to identify treating physicians' general experiences and expectations regarding geriatric assessment (GA) in older patients with cancer. MATERIALS AND METHODS: A survey was carried out in 9 Belgian hospitals, which participated in a national GA implementation project focusing on older patients with cancer. A newly developed questionnaire was completed by their treating physicians. Data collection comprised of reviewing hospital data, general respondent data, and treating physicians' general experiences and expectations regarding GA. Descriptive statistics were calculated. RESULTS: Eighty-two physicians from 9 hospitals participated. The GA team composition can vary substantially, with a nurse as core member. Ideally, all older patients with cancer in whom a treatment decision is necessary, should benefit from the GA. Nearly all GA domains are reported as very important. Availability of GA results can be improved. Treating physicians want geriatricians to coordinate geriatric recommendations related to the identified GA problems, and expect from trained healthcare workers (THCWs) to collect GA data, to report GA results, and to follow-up the implementation of geriatric recommendations. CONCLUSION: This study identifies relevant information for improving the implementation of GA in older patients with cancer in Belgium and reveals priorities for a THCW from the treating physician's point of view. To increase the effectiveness of GA, further efforts are needed to improve the implementation of geriatric recommendations. [less ▲]

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See detailVelocity and turbulence measurements for assessing the stability of riverbeds: a comparison between UVP and ADVP
Duma, Diana ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

in 11th International Conference on Hydroscience & Engineering - "Hydro-Engineering for Environmental Challenges" (2014, October)

Maintaining the overall stability of active riverbeds requires a deep understanding of the complex interactions between turbulent flow forces and forces stabilizing the riverbed. Standard approaches do ... [more ▼]

Maintaining the overall stability of active riverbeds requires a deep understanding of the complex interactions between turbulent flow forces and forces stabilizing the riverbed. Standard approaches do not properly take into account the turbulence fluctuations in non-uniform flows, while these are of primary importance in the mechanisms determining the stability of stones. In a new approach, the flow forces are quantified by means of parameters combining explicitly the velocity and turbulence distributions over a certain water depth above the riverbed. In this paper, as an onset for using these newly developed bed stability parameters, we report on new experimental measurements of velocity and turbulent kinetic energy based on acoustic methods, whereas all previous uses at the new bed stability parameters relied on Laser PIV Techniques. For quasi-uniform and non-uniform flow conditions, velocity measurements were conducted with two complementary devices: an ultrasonic velocimeter probe (UVP) and an acoustic Doppler velocimeter profiler (ADVP). The results are compared and discussed in detail. A general consistency between the two types of measurements is obtained, while some discrepancies are highlighted close to the bed and tentative explanations are given. [less ▲]

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See detailHarmonia axyridis population study in agroecosystems
Vandereycken, Axel ULg; Fassotte, Bérénice ULg; Durieux, Delphine ULg et al

Poster (2014, October)

The Multicoloured Asian ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is one of these species which was intentionally introduced for biological control and has spread from its native ... [more ▼]

The Multicoloured Asian ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is one of these species which was intentionally introduced for biological control and has spread from its native range in Central and Eastern Asia to large parts of North and South America, Europe, and Africa. The decline of native species is linked to the spread and the aggressive behaviour of H. axyridis. From 2009, we evaluated the population densities of aphids predator and predator diversities, with a special focus on H. axyridis in agroecosystems of Wallonia (South of Belgium). First, field crops preferences of H. axyridis were determined. Later, changes linked to aphid’s predator populations over time were evaluated. Finally, H. axyridis population changes between two crop farming methods were also evaluated. Samplings performed in agroecosystems highlighted that the community of aphid's predator is composed of few dominant species: three coccinellids (Coccinella septempunctata L., P. quatuordecimpunctata L., and H. axyridis), one syrphid (Episyrphus balteatus De Geer), and one chrysopid (Chrysoperla carnea Stephens). We demonstrated that H. axyridis do not invade all crops at the same rate, maize and broad bean being more infested than wheat and potato at both larval and adult stages. Moreover, H. axyridis populations in maize have strongly increased from 2009 to 2011. Finally, we showed that organic farming do not contribute to increase the abundance of H. axyridis but leads to increase the total abundance of aphid’s natural enemies. [less ▲]

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See detailInvestigation of shear stress evolution during neotissue growth in a perfusion bioreactor using 3d multiphysics modeling
Guyot, Yann ULg; Papantoniou, Ioannis; Schrooten, Jan et al

Conference (2014, October)

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See detailStudy of sex ratio and morphotypes of the Multicoloured Asian Ladybird, Harmonia axyridis Pallas in Belgian maize
Vandereycken, Axel ULg; Fassotte, Bérénice ULg; Barsics, Fanny ULg et al

Poster (2014, October)

Several insect species are known to have different morphotypes, an adaptation to heterogeneities in changing environments. This phenotypic plasticity could be a factor used by the Multicoloured Asian ... [more ▼]

Several insect species are known to have different morphotypes, an adaptation to heterogeneities in changing environments. This phenotypic plasticity could be a factor used by the Multicoloured Asian Ladybird, which is considered as an invasive species in Europe since its introduction in the 80’s. Harmonia axyridis has four major morphotypes: 2 melanic forms, conspicua and spectabilis; and 2 non-melanic, succinea and axyridis. In Belgium, only the three first are observed. Literature reports variations in morphotype frequencies, across native and introduced strains. These variations seem to be linked to climate (geographical and seasonal variation), with non-melanic forms being the most abundant in hot and arid climate. This study focused on the variation of morphotype abundance in H. axyridis according to season, field and gender. Adult ladybirds were caught from mid-July to mid-October 2012 into 5 maize fields. The proportions of observed morphotypes were compared according to the sampling season. The abundance of morphotypes was not significantly different through the fields; the observed ratios were 81.6%, 15% and 3.4% for succinea, spectabilis and conspicua respectively. Succinea was the most observed morphotype (χ2=755.8; P<0.001). The total number of collected males and females was the same with ratios of 48.2% and 51.8%: (χ2=0.93; P=0.33). The sex ratio was also not significantly different for each morphotype. There was no evolution of melanic and non-melanic form ratio according to the season, with 25.6% of melanic form in summer and 20.6% in autumn (χ2=1.22; P=0.27). Our results seem to show that morphotype adaptation according to the climate is not observed for Belgian ladybirds. [less ▲]

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See detailData processing of vibrational chemical imaging for pharmaceutical applications.
Sacre, Pierre-Yves ULg; De Bleye, Charlotte ULg; Chavez, Pierre-François ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2014), 101

Vibrational spectroscopy (MIR, NIR and Raman) based hyperspectral imaging is one of the most powerful tools analyze pharmaceutical preparation. Indeed, it combines the advantages of vibrational ... [more ▼]

Vibrational spectroscopy (MIR, NIR and Raman) based hyperspectral imaging is one of the most powerful tools analyze pharmaceutical preparation. Indeed, it combines the advantages of vibrational spectroscopy to imaging techniques and allows therefore the visualization of distribution of compounds, crystallization processes. However, these techniques provide a huge amount of data that must be processed to extract the relevant information. This review presents fundamental concepts of hyperspectral imaging, the basic theory of the most used chemometric tools used to pre-process, process and post-process the generated data. The last part of the present paper focuses on pharmaceutical applications of hyperspectral imaging and highlights the data processing approaches to enable the reader making the best choice among the different tools available. [less ▲]

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See detailAn asymptotic expansion-based method for a spectral approach in equivalent statistical linearization
Canor, Thomas ULg; Blaise, Nicolas ULg; Denoël, Vincent ULg

in Probabilistic Engineering Mechanics (2014), 38

Equivalent linearization consists in replacing a nonlinear system with an equivalent linear one whose parameters are tuned with regard to the minimization of a suitable function. In particular, the ... [more ▼]

Equivalent linearization consists in replacing a nonlinear system with an equivalent linear one whose parameters are tuned with regard to the minimization of a suitable function. In particular, the Gaussian equivalent linearization expresses the properties of an equivalent linear system in terms of the mean vector and the covariance matrix of the responses, which are the unknowns of the optimization problem in a spectral approach. Even though the system has been linearized, the resulting set of equations is nonlinear. The computational effort in this method pertains to the solution of a possibly large set of nonlinear algebraic equations involving integrals and inversions of full matrices. This work proposes to develop and apply an asymptotic expansion-based method to facilitate and to improve the statistical linearization for large nonlinear structures. The proposed developments demonstrate that for slightly to moderately coupled nonlinear systems, the equivalent linearization can be applied with an appropriate modal approach and eventually seen as a convergent series initiated with the stochastic response of a main decoupled linear system. With this method, the computational effort is attractively reduced, the conditioning of the set of nonlinear algebraic equations is improved and inversion of full transfer matrices and repeated integrations are avoided. The paper gives a formal description of the method and illustrates its implementation and performances with the computation of stationary responses of nonlinear structures subject to coherent random excitation fields. [less ▲]

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