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See detailThe evolution of states and phase transitions under cooling of the early universe within the two-Higgs-doublet model
Ginzburg, I. F.; Ivanov, Igor ULg; Kanishev, K. A.

in Russian Physics Journal (2010, June), 53(6), 575-600

The two-Higgs-doublet model (2HDM) realizes ground states (vacuum) with different properties for different parameter values. The parameters of the effective potential change during cooling of the Universe ... [more ▼]

The two-Higgs-doublet model (2HDM) realizes ground states (vacuum) with different properties for different parameter values. The parameters of the effective potential change during cooling of the Universe after the Big Bang. In so doing, the properties of vacuum state can be affected, phase transitions take place. The evolution of phase states and the set of phase transitions can turn out to be much wider than those accounted for within the conventional Standard model (SM) with a single Higgs doublet. The phase history of the Universe is analyzed for any specified set of the 2HDM parameters. All possible variants of the history are considered. Sets of modern, observed, in principle, parameters corresponding to different sequences of thermal phase transitions are determined. Possible cosmological consequences are briefly discussed. [less ▲]

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See detailEvolution of the Antarctic surface mass balance by high-resolution downscaling and impact on sea-level change for the next centuries
Agosta, Cécile ULg; Favier, Vincent; Krinner, Gerhard et al

Conference (2012, July)

Most of the IPCC-AR4 Atmospheric Global Circulation Models (AGCM) predict an increase of the Antarctic Surface Mass Balance (SMB) during the 21st century that would mitigate global sea level rise. Present ... [more ▼]

Most of the IPCC-AR4 Atmospheric Global Circulation Models (AGCM) predict an increase of the Antarctic Surface Mass Balance (SMB) during the 21st century that would mitigate global sea level rise. Present accumulation and predicted change are largest at the ice sheet margins because they are driven by snowfall, which mostly comes from warm, moist air arising over the land slopes. The coastal belt is also where complex processes of sublimation, melt and refreezing occur. Thus, high-resolution modelling is necessary to adequately capture the effects of small-scale variations in topography on the atmospheric variables in this area, but limitations in computing resources prevent such resolution at the scale of Antarctica in full climate models. We present here a downscaling method leading to 15-km SMB resolution for century time-scales over Antarctica. We compute the effect of the fine topography on orographic precipitation and on boundary layer processes that lead to sublimation, melt and refreezing. We first display the SMB downscaled from ERA-Interim and show that the downscaling improves the agreement between modelled and observed SMB for the end of the 20th century. We then present hi-resolution features of the Antarctic SMB evolution during the 21st century downscaled from LMDZ4 for different scenarios. We show that a higher resolution induce at the same time more run-off but a significantly higher mitigation of sea level rise. [less ▲]

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See detailEvolution of the clinical expression of Bluetongue in Belgian cattle during year 2006 vs 2007
Guyot, Hugues ULg; Mauroy, Axel ULg; Rollin, Frédéric ULg et al

Conference (2008)

In August 2006, Belgium notified its first cases of Bluetongue (BT), serotype 8, in cattle and sheep. The disease was also observed at this time in the neighboring countries. The resurgence of BT was ... [more ▼]

In August 2006, Belgium notified its first cases of Bluetongue (BT), serotype 8, in cattle and sheep. The disease was also observed at this time in the neighboring countries. The resurgence of BT was observed in Northern Europe in 2007. The aim of the study was to compare clinical signs of BT observed in 2006 vs 2007 in Belgian cattle. The description of clinical signs was based on the observation of 38 and 39 cows in 2006 and 2007, respectively. BT cases were only included if they were confirmed by one or both laboratory diagnostic tests (competitive ELISA test and/or RT-qPCR). The inventory of clinical signs was made with a standardised clinical form for BT. This form is divided into general, cutaneous, locomotor, digestive, respiratory, neurological and reproductive clinical signs. Case data were summarised to determine changes in clinical presentation of BT between 2006 and 2007. A Fischer’s exact probability test was performed to compare (P<0.05) the frequency of clinical signs between the two years. Regarding general clinical signs, hyperthermia and tiredness were more often observed in 2007, compared to 2006. All clinical signs about skin and annexes were not significantly different between the two years. Locomotor signs such as prostration, incapacity to get up, reluctance to move, lameness and amyotrophy were more frequent in 2007. Loss of appetite, difficulties in grasping feed, salivation and drooling were the digestive signs more often observed in 2007. A purulent nasal discharge was the only respiratory sign more commonly observed in 2007. Apathy, generalised weakness and paresis or paralysis were more often encountered in 2007. The most important changes between the two years concerned reproduction. A higher incidence of abortion, premature calving and stillbirth was observed during 2007 outbreak. The frequency of most of the clinical signs of BT was higher in 2007 in Belgian cattle. Confirmed cases of BT in Belgian cattle were only 296 in 2006 compared to 4187 in 2007. These data do not represent the real situation of BT infection because the farmers do not notify all cases. Nevertheless, it seems that the 2007 outbreak was more severe regarding the number of cases and the frequency of clinical signs. The mild winter and wet 2007 summer might have favored the persistence of the vectors. [less ▲]

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See detailEvolution of the content of THC and other major cannabinoids in drug-type cannabis cuttings and seedlings during growth of plants
DE BACKER, Benjamin ULg; Maebe, Kevin; Verstraete, Alain G. et al

in Journal of Forensic Sciences (2012), 57(4), 918-922

In Europe, authorities frequently ask forensic laboratories to analyze seized cannabis plants to prove that cultivation was illegal (drug type and not fiber type). This is generally done with mature and ... [more ▼]

In Europe, authorities frequently ask forensic laboratories to analyze seized cannabis plants to prove that cultivation was illegal (drug type and not fiber type). This is generally done with mature and flowering plants. However, authorities are often confronted with very young specimens. The aim of our study was to evaluate when the chemotype of cannabis plantlets can be surely determined through analysis of eight major cannabinoids content during growth. Drug-type seedlings and cuttings were cultivated, sampled each week, and analyzed by high-performance liquid chromatography with diode array detection. The chemotype of clones was recognizable at any developmental stage because of high total Delta-9-tetrahydrocannabinol (THC) concentrations even at the start of the cultivation. Conversely, right after germination seedlings contained a low total THC content, but it increased quickly with plant age up, allowing chemotype determination after 3 weeks. In conclusion, it is not necessary to wait for plants’ flowering to identify drug-type cannabis generally cultivated in Europe. [less ▲]

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See detailEvolution of the early Earth biosphere
Javaux, Emmanuelle ULg

Conference (2005)

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See detailThe evolution of the Fair Trade organisational landscape in France and in Belgium
Huybrechts, Benjamin ULg

Conference (2008, May 14)

Parallel to the dramatic growth of its sales and public awareness, the Fair Trade movement has seen its organisational landscape become increasingly diversified. While Fair Trade nonprofit pioneers were ... [more ▼]

Parallel to the dramatic growth of its sales and public awareness, the Fair Trade movement has seen its organisational landscape become increasingly diversified. While Fair Trade nonprofit pioneers were initially relatively homogeneous in terms of goals and structures, the economic development of the initiative, driven by the sales of Fair Trade products in mainstream distribution channels, has led to the emergence of a multitude of new actors with much more heterogeneous behaviours – in spite of the general trend towards a stronger market orientation – (Gendron, 2004; Moore, 2004; Nicholls & Opal, 2005; Renard, 2003). When observing the evolution of Fair Trade organisations (FTOs), i.e., organisations claiming to be totally dedicated to Fair Trade, three trends can be observed: Fair Trade pioneers have adopted more business-oriented profiles and more complex and specialised organisational structures; New small Fair Trade businesses have emerged with a stronger economic specialisation on a particular product or distribution channel ; « Old » and « new » FTOs increasingly gather into networks with two types of purposes: to promote Fair Trade and to have a minimum political representation (advocacy networks) and to face common socio-economic challenges (socio-economic networks). The goal of this contribution is to analyse these three trends with the help of a sample of nearly fourty FTOs in Belgium and in the French Rhône-Alpes region. We can thus illustrate the three trends on the basis of both general observations and precise examples. We also try to compare the two regions and to explore to what extent the evolution of FTOs reveals more global trends within the Fair Trade movement. [less ▲]

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See detailThe evolution of the inorganic fluorine budget since the mid-1980s based on FTIR measurements at northern mid-latitudes
Duchatelet, Pierre ULg; Feng, Wuhu; Chipperfield, Martyn et al

in Geophysical Research Abstracts (2011)

Fluorine enters the stratosphere principally in the form of CFCs (chlorofluorocarbons, mainly CFC-12 and CFC-11), HCFCs (hydrochlorofluorocarbons, mainly HCFC-22) and HFCs (hydrofluorocarbons, mainly HFC ... [more ▼]

Fluorine enters the stratosphere principally in the form of CFCs (chlorofluorocarbons, mainly CFC-12 and CFC-11), HCFCs (hydrochlorofluorocarbons, mainly HCFC-22) and HFCs (hydrofluorocarbons, mainly HFC-134a) which have been (or are still) widely emitted at ground level by human activities. In the lower stratosphere, the photolysis of these halogenated source gases leads to the formation of the two fluorine reservoirs COClF and COF2. The subsequent photolysis of these two compounds frees F atoms, which principally react with CH4 and H2O to form the extremely stable HF gas, by far the dominant fluorine reservoir in the middle and upper stratosphere. Despite the fact that fluorine does not significantly contribute in stratospheric ozone depletion, measurements of the concentrations of individual F-containing species in different altitude ranges of the atmosphere are important as they reflect the amounts of anthropogenic gases transported into the middle atmosphere as well as their decomposition. Such measurements also provide insight into the partitioning between major fluorine source gases (which are potent greenhouse gases) and reservoirs and allows a global inventory of organic (CFy), inorganic (Fy) and total (FTOT) fluorine burdens to be monitored as a function of time. Indeed, regular updates of such inventories are important as the partitioning between F-containing gases in the stratosphere is continually evolving as emissions of anthropogenic gases from the surface change, principally as a consequence of the progressive ban on the production of CFCs and HCFCs adopted by the Montreal Protocol and its subsequent Amendments and Adjustments. To complement recent studies regarding fluorine species (Duchatelet et al., 2009, 2010, 2011; Mahieu et al., 2011), this communication presents the time series of the inorganic fluorine budget Fy over the last twenty-five years, based on HF and COF2 total column amounts derived from high resolution Fourier transform infrared (FTIR) solar spectra recorded at Jungfraujoch (46.5°N, 8.0°E, 3580m asl). A trend analysis of our HF, COF2 and Fy time series is performed and discussed in the context of past and current emissions of halogenated source gases. Comparisons with model and space data are also included. [less ▲]

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See detailEvolution of the Io footprint brightness I: Far-UV observations
Bonfond, Bertrand ULg; Hess, Sébastien; Gérard, Jean-Claude ULg et al

in Planetary and Space Science (2013), 88

The Io footprint (IFP) is a set of auroral spots and an extended tail resulting from the strong interaction between Io and the Jovian magnetosphere. For the first time, we present measurements of the ... [more ▼]

The Io footprint (IFP) is a set of auroral spots and an extended tail resulting from the strong interaction between Io and the Jovian magnetosphere. For the first time, we present measurements of the brightness and precipitated power for each individual spot, using the image database gathered from 1997 to 2009 with the Hubble Space Telescope in the Far-UV domain. We show that the relative brightness of the spots varies with the System III longitude of Io. Moreover, our novel measurement method based on 3D simulations of the auroral features allows to derive the precipitated energy fluxes from images on which the emission region is observed at a slant angle. Peak values as high as 2 W/m² are observed for the main spot, probably triggering a localized and sudden heating of the atmosphere. Additionally, strong brightness differences are observed from one hemisphere to another. This result indicates that the location of Io in the plasma torus is not the only parameter to control the brightness, but that the magnetic field asymmetries also play a key role. Finally, we present new data confirming that significant variations of the spots' brightness on timescales of 2-4 minutes are ubiquitous, which suggests a relationship with intermittent double layers close to Jovian surface. [less ▲]

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See detailEvolution of the Io Footprint Brightness II: Modeling
Hess, Sébastien; Bonfond, Bertrand ULg; Chantry, Virginie ULg et al

in Planetary and Space Science (2013), 88

The interaction of Io with the Jovian magnetosphere creates the best known and brightest satellite-controlled aurorae in our solar system. These aurorae are generated by the precipitation of electrons ... [more ▼]

The interaction of Io with the Jovian magnetosphere creates the best known and brightest satellite-controlled aurorae in our solar system. These aurorae are generated by the precipitation of electrons, which are accelerated by the Alfvén waves carrying the current between the satellite and the planet. A recent study computed the energy deposited on top of Jupiter's ionosphere due to the electron precipitation and retrieved the correct mean brightness of Io-related aurorae. The model developed in this study takes into account the acceleration mechanism and the Alfvén wave propagation effects. We use the same method to investigate the brightness variation of the different components of the Io footprint as a function of longitude. These observations are discussed in a companion paper. We identify several effects that act together to modulate the footprint brightness such as Alfvén wave reflections, magnetic mirroring of the electrons, the local interaction at Io and kinetic effects close to Jupiter. We identify the effects contributing the most to the modulation of the brightnesses of the three brightest components of the Io footprints: the main and reflected Alfvén wing spots and the transhemispheric electron spot. We show in particular that the modulation of the efficiency of the electron acceleration can be of greater importance than the modulation of the power generated at Io. We reproduce the average modulation of the spot brightnesses and present an extensive discussion of possible explanations for the observed features not reproduced by our model. [less ▲]

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See detailEvolution of the Io footprint morphology
Bonfond, Bertrand ULg; Grodent, Denis ULg; Gérard, Jean-Claude ULg et al

Conference (2008, April)

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See detailEvolution of the Kızılırmak river and its interaction with the North Anatolian Fault, Turkey
Drab, Laureen; Hubert, Aurelia ULg; Benedetti, Lucilla et al

in AGU Abstract (2010, December)

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See detailEvolution of the Peierls distortion in liquid As xSb 1-x compounds
Raty, Jean-Yves ULg; Gaspard, Jean-Pierre ULg; Ceolin, R. et al

in Journal of Non-Crystalline Solids (1998), 232-234

The local order in the liquid binary alloy As xSb 1-x (0lesxles1) is studied by short-wavelength (lambda=0.7 Aring) neutron scattering. The coordination number (Z) and the interatomic distances (d) are ... [more ▼]

The local order in the liquid binary alloy As xSb 1-x (0lesxles1) is studied by short-wavelength (lambda=0.7 Aring) neutron scattering. The coordination number (Z) and the interatomic distances (d) are analyzed in terms of the As concentration: Z increases continuously, from a value of 3.5 for pure arsenic to a value of 6.3 for pure antimony, whereas d shows a departure from Vegard's rule. The interatomic distance increases in the range 0.15lesxles1.00 and is almost constant in the range 0.00lesxles0.15. A simple tight-binding model is developed, which indicates that the relevant parameter is the hardness of the core repulsion between the atoms [less ▲]

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See detailEvolution of the Peierls distortion in liquid AsxSb1-x compounds
Raty, Jean-Yves ULg; Gaspard, Jean-Pierre ULg; Céolin, R. et al

in Journal of Non-Crystalline Solids (1998), 232-234

The local order in the liquid binary alloy AsxSb1-x (0 ≤ x ≤ 1) is studied by short-wavelength (λ = 0.7 Å) neutron scattering. The coordination number (Z) and the interatomic distances (d) are analyzed in ... [more ▼]

The local order in the liquid binary alloy AsxSb1-x (0 ≤ x ≤ 1) is studied by short-wavelength (λ = 0.7 Å) neutron scattering. The coordination number (Z) and the interatomic distances (d) are analyzed in terms of the As concentration: Z increases continuously, from a value of 3.5 for pure arsenic to a value of 6.3 for pure antimony, whereas d shows a departure from Vegard's rule. The interatomic distance increases in the range 0.15 ≤ x ≤ 1.00 and is almost constant in the range 0.00 ≤ x ≤ 0.15. A simple tight-binding model is developed, which indicates that the relevant parameter is the hardness of the core repulsion between the atoms. © 1998 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailEvolution of the periodicity of the W UMa system Epsilon CrA
Manfroid, Jean ULg; Heck, A.; Lunel, M. et al

in Astronomy and Astrophysics (1987), 176

Photometric uvby observations of Epsilon CrA obtained with the 1-m telescope at ESO during 1985 are compiled in tables along with published photometry from the period 1960-1984 and analyzed ... [more ▼]

Photometric uvby observations of Epsilon CrA obtained with the 1-m telescope at ESO during 1985 are compiled in tables along with published photometry from the period 1960-1984 and analyzed comprehensively. The results are presented in O-C diagrams and discussed, and a relative increase of 0.00001 in the period of the object is detected. It is pointed out that this change may have been gradual (over a 5-10-yr period) or abrupt (at about HJD 2,440,000), but that the period appears to have become stable again in the most recent observations. [less ▲]

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See detailEvolution of the polarization of the optical afterglow of the γ-ray burst GRB030329
Greiner, Jochen; Klose, Sylvio; Reinsch, Klaus et al

in Nature (2003), 426

The association of a supernova with GRB030329 strongly supports the `collapsar' model of γ-ray bursts, where a relativistic jet forms after the progenitor star collapses. Such jets cannot be spatially ... [more ▼]

The association of a supernova with GRB030329 strongly supports the `collapsar' model of γ-ray bursts, where a relativistic jet forms after the progenitor star collapses. Such jets cannot be spatially resolved because γ-ray bursts lie at cosmological distances; their existence is instead inferred from `breaks' in the light curves of the afterglows, and from the theoretical desire to reduce the estimated total energy of the burst by proposing that most of it comes out in narrow beams. Temporal evolution of the polarization of the afterglows may provide independent evidence for the jet structure of the relativistic outflow. Small-level polarization (~1-3 per cent) has been reported for a few bursts, but its temporal evolution has yet to be established. Here we report polarimetric observations of the afterglow of GRB030329. We establish the polarization light curve, detect sustained polarization at the per cent level, and find significant variability. The data imply that the afterglow magnetic field has a small coherence length and is mostly random, probably generated by turbulence, in contrast with the picture arising from the high polarization detected in the prompt γ-rays from GRB021206 (ref. 18). [less ▲]

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See detailEvolution of the populations of Cystoseira balearica (Phaeophyceae) and epiphytic Bangiophyceae in the Bay of Calvi (Corsica) in the last eight years
Hoffman, Lucien; Clarisse, Serge; Detienne, Xavier et al

in Bulletin de la Société Royale des Sciences de Liège (1988), 4-5

In a number of stations covering the Bay of Calvi (Corsica, Mediterranean Sea) we studied the development of the macroscopic brown alga Cyctoseira balearica and of the epiphytic microscopic Bangiophyceae ... [more ▼]

In a number of stations covering the Bay of Calvi (Corsica, Mediterranean Sea) we studied the development of the macroscopic brown alga Cyctoseira balearica and of the epiphytic microscopic Bangiophyceae. Cystoseira balearica is a major component of infralittoral communities on rocky substrates and Bangiophyceae have been considered indicators of eutrophication. The epiphytic Bangiophyceae have indeed their optimal developement near the sewages discharges (especially in summer) and near the town of Calvi. Since 1981 an increase is observed in the abundance of the Bangiophycae. Cystoseira balearica, a pollution-sensitive species, is not present in the harbours of the town of Cavi and near the sewage dicharges. Since 1980 the coverage and the standing crop of this alga have decreased. The increase of Bangiophyceae and the concurrent decrease of Cyctoseira balearica seem to indicate an increasing pollution of the waters of the Bay of Calvi in the period 1980 - 1988. [less ▲]

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See detailEvolution of the prevalence and characteristics of anemia in inflammatory bowel diseases between 1993 and 2003
Vijverman, A.; Piront, Patricia ULg; Belaiche, Jacques ULg et al

in Acta Gastro-Enterologica Belgica (2006), 69(1, Jan-Mar), 1-4

Introduction : Anemia has been considered as an overlooked complication of inflammatory bowel disease. Studies dating back to the 80ties and the 90ties have shown 30% of anemia among inflammatory bowel ... [more ▼]

Introduction : Anemia has been considered as an overlooked complication of inflammatory bowel disease. Studies dating back to the 80ties and the 90ties have shown 30% of anemia among inflammatory bowel disease (IBD) patients. More recently, the broader use of immunosuppressive drug and infliximab allowing better mucosal healing as well as a more aggressive treatment of anemia, including the use of safer form of IV iron, may have influenced the prevalence of anemia among IBD patients. Our aim was to asses the prevalence and characteristics of anemia among two cohorts of IBD patients at 10 years interval and to look for associated clinical or demographic factors. Methods: using the IBD patients register of one senior gastroenterologist, we identified IBD patients he had consecutively seen and who had blood test at the outpatient clinic during the years 1993 and 2003. Demographic and clinical characteristics, treatment for Crohn's disease, blood test results and treatment of anemia were recorded and compared between these two cohorts. Anemia was defined as an hemoglobin level lower than the normal value of the laboratory of our hospital. Results : 80 and 90 patients were identified in 1993 and 2003, respectively. There was no significant difference between the two cohorts, according to age, gender, disease type, duration or location. There were 27/80 (33.8%) and 15/90 (16.7%) anemic patients in 1993 and 2003, respectively (P = 0.013). The prevalence of severe anemia (hemoglobin level < 10.5 g/100 ml) was similar in the two cohorts (6.3% and 5.6%). Characteristics of the anemia were similar in the two cohorts with a majority of iron deficiency anemia and inflammatory anemia. Ferritin and CRP levels were not significantly different in the two cohorts. The only significant difference was a more frequent use of immunosuppressive treatment and infliximab in 2003 than in 1993 (33.3% vs. 13.8%; P = 0.0038, RR :0.41, 0.22-0.77) Conclusions : Prevalence of mild to moderate anemia has significantly decreased in our population over the last 10 years. The only difference detected between the two cohorts was the increased use of immunosuppressive drug (mainly azathioprine). [less ▲]

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