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See detailStudy of Genetic Variability of Fatty Acid Profile in Bovine Milk and Fat Using Mid-Infrared Spectrometry
Soyeurt, Hélène ULg

Doctoral thesis (2008)

Changes in milk fat composition influence its nutritional quality as well as the technological properties of butter. The impact of feed on fat composition is well known; however, limited information is ... [more ▼]

Changes in milk fat composition influence its nutritional quality as well as the technological properties of butter. The impact of feed on fat composition is well known; however, limited information is available on the genetic variability of fatty acids in bovine milk. The overall aim of this PhD thesis was to study the genetic variability of fatty acid profile in bovine milk and fat. This type of research needs a large amount of data. Expensive reference analysis is used to measure the fatty acid contents in fat. The first objective of this thesis was to develop an alternative method that could be faster and cheaper than traditional methods. Calibration equations predicting the contents of fatty acid from mid-infrared spectrum were established. The contents of saturated and monounsaturated fatty acids, omega-9, fatty acids with short, medium and long chain were the best predicted. Thanks to the implementation of this method in the Walloon routine milk recording, more than 20,000 milk samples were analyzed. This database permitted to model the variation of fatty acid contents in milk and fat. From these models, the genetic variability of fatty acid profile was shown. The complexity of models increased throughout this project due to the increase of new available data. Differences across 7 dairy breeds were estimated using single and multi-trait mixed models. Milk fat and delta-9 desaturase activity of Jersey and dual purpose Belgian Blue differed significantly from Holsteins. Therefore, the choice of a given breed could modify the fat composition. Heritability values obtained for studied fatty acids with multi-trait mixed model ranged from 0.05 to 0.42. Higher values were observed for saturated compared to unsaturated fatty acids. Moderate heritability estimates were observed for the activity of delta-9 desaturase (0.20) and the hardness of butter (0.27). These two traits were estimated by specific fatty acid ratios. The heritability observed using a multi-trait random regressions test day model for the content of saturated fatty acids (0.42) was similar to the one observed for the percentage of fat (0.37). Considering the impact of selection on fat content, the selection could have a great impact on fat composition. High genetic correlations were observed between some fatty acids having similarities in their synthesis. Heritability and correlations varied through the duration of the lactation. Due to the large number of fatty acids, the estimation of an index, which includes the proper fatty acid profile, could be interesting for a future selection program. This PhD thesis provides the background required by future studies to estimate the impact of animal selection on milkfat composition. [less ▲]

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See detailSolar activity in connection with a 2.5 years periode cycle in air temperature time series using the Morlet wavelet method
Nicolay, Samuel ULg; Mabille, Georges ULg; Fettweis, Xavier ULg et al

Conference (2008, April 17)

The Morlet wavelet is applied to air temperature time series obtained from several weather stations and reveals the existence of a period cycle of 20-30 months since 1950, with an estimated amplitude of 0 ... [more ▼]

The Morlet wavelet is applied to air temperature time series obtained from several weather stations and reveals the existence of a period cycle of 20-30 months since 1950, with an estimated amplitude of 0.5 C. The origin of this period is investigated by computing the scale spectra associated to the principal indices that characterize air mass flows in the troposphere and the stratosphere, as well as the signals related to the sunspot number and the solar flux. Each analysed signal shows this period of approximatively 2.5 years. This suggests that the 2.5 years-cycle could be resulted from the solar activity. [less ▲]

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See detailNew pH-sensitive flower micelles for potential tumour targeting
Cajot, Sébastien ULg; Van Butsele, Kathy; Jérôme, Christine ULg

Poster (2008, April 16)

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See detailFunctional Development of Advanced Driver Assistance Systems by means of Driving Simulators
Christen, Fréderic ULg; Benmimoun, A.; Deutschle, S.

Poster (2008, April 16)

Der Beitrag beschreibt die Funktionsentwicklung von Fahrerassistenzsystemen an der Forschungsgesellschaft Kraftfahrwesen mbH Aachen (fka) und am Institut für Kraftfahrwesen (ika) der RWTH Aachen mittels ... [more ▼]

Der Beitrag beschreibt die Funktionsentwicklung von Fahrerassistenzsystemen an der Forschungsgesellschaft Kraftfahrwesen mbH Aachen (fka) und am Institut für Kraftfahrwesen (ika) der RWTH Aachen mittels Fahrsimulatoren. Dabei wird konkret auf die Entwicklung eines Kreuzungsassistenten sowie eines sogenannten KONVOI-Systems eingegangen. Beide Systeme wurden u.a. unter Verwendung des statischen Fahrsimulators InDriveS entwickelt. Der in diesem Beitrag vorgestellte Ansatz eines Kreuzungsassistenten basiert auf Kommunikation: Fahrzeug-Fahrzeug-Kommunikation (C2C) und Infrastruktur-Fahrzeug- Kommunikation (I2C). Hierfür wurden in der Verkehrsfluss- und Fahrsimulation verschiedene Systemvarianten betrachtet, um unterschiedliche Stufen der Systemkomplexität und unter- schiedliche Zeitrahmen für die Realisierung eines solchen Assistenten zu berücksichtigen. Jede dieser Systemvarianten wurde hinsichtlich deren Wirkung auf die Verkehrssicherheit bewertet. Daneben wurde auch die Benutzerakzeptanz unter Berücksichtigung verschiedener Mensch-Maschine-Schnittstellen betrachtet. Die Ergebnisse zeigen, dass die Kommunikationsreichweite der wichtigste Parameter für die Systemauslegung und -spezifikation darstellt. Für die Wirkung des Kreuzungsassistenten auf die Verkehrssicherheit ist in erster Linie der Ausrüstungsgrad entscheidend. Für die Benutzerakzeptanz ist die Detektionsrate von möglichen Konfliktsituationen und die Vermeidung von kritischen Situationen entscheidend. Das dargestellte KONVOI-System ermöglicht die Automatisierung von Nutzfahrzeugkolonnen auf Autobahnen. Neben der Funktionsentwicklung zur automatischen Abstandsregelung und Querführung werden in dem Projekt die Auswirkungen von KONVOIs auf den übrigen Verkehr analysiert und die bei den Fahrern auftretenden Belastungen und die Akzeptanz des Systems untersucht. Begleitend werden rechtliche Aspekte der kommerziellen Nutzung von Lkw-KONVOIs in Deutschland weiterentwickelt. Um die Komplexität der zu entwickelnden Lösungen zur Funktionserweiterung der Fahrzeuge zu bewältigen und eine hohe Zuverlässigkeit der Systeme zu gewährleisten, erfolgt die Systementwicklung mit Hilfe von Simulationswerkzeugen (MATLAB/Simulink, Stateflow, Verkehrsflusssimulation PELOPS und Lkw- Fahrsimulator InDriveS). Abschließend geht der Beitrag auf den neuen dynamischen Fahrsimulator der RWTH Aachen ein. [less ▲]

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See detailMIPAS: an instrument for atmospheric and climate research
Fischer, H.; Birk, M.; Blom, C. et al

in Atmospheric Chemistry and Physics (2008), 8(8), 2151--2188

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See detailContribution of "click chemistry" to the synthesis of antimicrobial aliphatic copolyester
Riva, Raphaël ULg; Lussis, Perrine ULg; Lenoir, Sandrine ULg et al

in Polymer (2008), 49(8), 2023-2028

A straightforward strategy is proposed to impart antimicrobial properties to biodegradable poly(oxepan-2-one) (poly(epsilon-caprolactone) or PCL), which is based on the grafting of pendant ammonium salts ... [more ▼]

A straightforward strategy is proposed to impart antimicrobial properties to biodegradable poly(oxepan-2-one) (poly(epsilon-caprolactone) or PCL), which is based on the grafting of pendant ammonium salts by "click" chemistry. First, statistical copolymerization of 3-chlorooxepan-2-one (alpha-chloro-epsilon-caprolactone or alpha Cl epsilon CL) with oxepan-2-one (epsilon-caprolactone or epsilon CL) was initiated by 2,2-dibutyl-2-stanna-1,3-dioxepane (DSDOP). In a second step, pendant chlorides were converted into azides by reaction with sodium azide (NaN3). Finally, quaternary ammonium containing alkynes were quantitatively added to the pendant azide groups of PCL by the copper-catalyzed Huisgen's 1,3-dipolar cycloaddition, which is a typical "click" reaction. An alternative two-step strategy based on the cycloaddition of the amine containing alkyne onto the pendant azides, followed by quaternization turned out to be less efficient. The antimicrobial activity was analyzed by the "shaking flask method" in the presence of Escherichia coli [less ▲]

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See detailA record negative Greenland ice sheet surface mass balance rate in 2007
Fettweis, Xavier ULg

Poster (2008, April 15)

Results made with the regional climate model MAR show a record surface melt (592 km³/yr = a global sea level rise of 1.6 mm/yr) of the Greenland ice sheet (GrIS) during summer 2007 compared with 1970-2006 ... [more ▼]

Results made with the regional climate model MAR show a record surface melt (592 km³/yr = a global sea level rise of 1.6 mm/yr) of the Greenland ice sheet (GrIS) during summer 2007 compared with 1970-2006. This record melt, detected also in the microwave satellite data, is associated with very low snowfall (508 km³/yr) inducing a negative Surface Mass Balance (SMB) rate of -65 km³/yr. Such a negative simulated SMB rate is unprecedented in the recent Greenland history. The summer 2007 is associated with a positive SST anomaly, a negative 2006-2007 GrIS winter accumulation and anomalous advection of warm air masses over the GrIS. Sensitivity experiments carried out by the MAR model evaluate the impacts of these anomalies on the Greenland climate and SMB. The main impacts of a warmer SST anomaly in the MAR model are more precipitation over Greenland due to an enhanced evaporation above the ocean and, an increase of surface melt induced by the advection of warmer oceanic air (>0°C) into the continent by the atmospheric part of MAR. A negative winter accumulation anomaly exposes ice and old snow (with a lower albedo) earlier than previous years in the ablation zone which significantly increases the melting given the albedo feedback. Finally, changes in the boundaries forcing of the MAR model test the consequence of the anomalous persistent southerly airflow during June and July. [less ▲]

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See detailEstimation of the 1900-2100 Greenland ice sheet surface mass balance
Fettweis, Xavier ULg

Conference (2008, April 15)

Results from a 37-year simulation (1970-2006) over the Greenland ice sheet (GrIS) with the regional climate model MAR reveals that more than 97% of the interannual variability of the modelled Surface Mass ... [more ▼]

Results from a 37-year simulation (1970-2006) over the Greenland ice sheet (GrIS) with the regional climate model MAR reveals that more than 97% of the interannual variability of the modelled Surface Mass Balance (SMB) is explained by the GrIS summer temperature anomaly and the GrIS annual precipitation anomaly. This dependence is also fully confirmed by another model using the ECMWF (re)analysis. This multiple regression is then used to empirically estimate the GrIS SMB since 1900 from climatological time series and reanalysises. The projected SMB changes in the 21st century are investigated with the set of simulations performed with AOGCM's for the IPCC Fourth Assessment Report. These estimations show that the high surface mass loss rates of these last years (1998, 2003, 2006) are not unprecedented in the GrIS history of the last hundred years. The minimum SMB rate seems to be occurred in the 1930's due to a combination of dryer and warmer years than now although the effect of the man-induced global warming was not perceptible at that time. The AOGCM's project that the SMB rate of the 1930s would be common at the end of this century. The temperature would be higher than in the 1930s but the increase of accumulation would partly offset the acceleration of surface melt due to the temperature increase. If no change will occur in the iceberg discharge rate, such negative SMB rates would be not large enough to significantly increase in the future the fresh meltwater flux from the GrIS into the ocean. However, these assumptions are based on an empirical multiple regression only currently validated and the accuracy and time homogeneity of the data sets and AOGCM results used in these estimations constitute a large uncertainty. [less ▲]

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See detailImpacts of ice sheet mask and resolution on estimating the surface mass balance of the Greenland ice sheet
Fettweis, Xavier ULg

Poster (2008, April 15)

The impacts of the spatial resolution and a Greenland ice sheet (GrIS) mask on modelling the Surface Mass Balance (SMB) are studied with the regional climate model MAR coupled with a complex energy ... [more ▼]

The impacts of the spatial resolution and a Greenland ice sheet (GrIS) mask on modelling the Surface Mass Balance (SMB) are studied with the regional climate model MAR coupled with a complex energy balance/snowpack model. On the one hand, too coarse resolution prevents the model from resolving adequately the steep ice sheet margin and the ablation zone, not wider than 100 km in Greenland, where substantial seasonal melting occurs. The resolution affects also the precipitation modelling. On the other hand, a too large ice sheet mask (i.e. with low-altitude ice pixels in the model, where there is no ice in reality) leads to an overestimation of the run-off. In addition, due to the albedo feedback, biases in the ice sheet mask have also consequences on the surface energy balance. [less ▲]

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See detailPolyomavirus in Renal Transplantation: A Hot Problem
Bonvoisin, Catherine ULg; Weekers, Laurent ULg; Xhignesse, Patricia ULg et al

in Transplantation (2008), 85(7S), 42-48

Polyomavirus BK has emerged as an important complication after kidney transplantation. Although, BK nephropathy develops in only1%to5%of renal transplant recipients, its prognosis when present is very ... [more ▼]

Polyomavirus BK has emerged as an important complication after kidney transplantation. Although, BK nephropathy develops in only1%to5%of renal transplant recipients, its prognosis when present is very poor. The most accepted risk factor is the level of immunosuppressive treatment, but the serostatus of donor and recipient and the absence of human leukocyte antigen C7 in donor and/or recipient influence the BK virus (BKV) reactivation. The gold standard in diagnosing BKV nephropathy (BKVN) continues to be biopsy with use of immunohistochemistry for large T antigens. Urinary decoy cells and blood BKV DNA polymerase chain reaction are used in the screening, but their positive predictive values are poor. However, their use as predictors of the evolution of BKVN is more valuable. The reduction of immunosuppressive therapy currently represents the first-line treatment for BKVN. Cidofovir and leflunomide can be used when BKVN continues to progress. In the event of graft loss, retransplantation is possible with a low risk of recurrence when the infection is no longer active. [less ▲]

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See detailCaractérisation phénotypique et gestion de la population de poulets locaux dans les communes de Dassa et de Toffo au Bénin
Chabi Toko, Roukayath ULg

Master of advanced studies dissertation (2008)

Morphometrical and morphological characters of 663 local chickens and management technique, production and breeding aims of 97 breeders were studied in Dassa and Toffo district in Benin. Different ... [more ▼]

Morphometrical and morphological characters of 663 local chickens and management technique, production and breeding aims of 97 breeders were studied in Dassa and Toffo district in Benin. Different phenotypes were identified in the study area: the chicken with normal feathering, the naked neck, the frizzle feathered the soft feathering and the polydactyl. Feather colour of local poultry is variable but the partridge (18.55 %), the black (12.52 %), the light brown (9.05 %) and the brown (8.13 %) are dominants. The comb is predominantly with a simple type (99 %) and essentially the pink (59.58 %) and light pink (29.26 %) colour are encountered. The ear lobes are pink (45.40 %) and white (36.80 %). The beak colour goes from white (0.3 %) through yellow (9.61 %) and black (27.45 %) to brown (40.27 %). The skin is essentially pink, light pink but legs are white and grey. Eyes are most orange (70.14 %) and brownish (27.75 %). The two sexes were not significantly different for body measurements. The hen weighs 773.04 g ± 322.71 and the coq 745.84 g ± 353.7. The region had an effect on body measurements because Dassa’s chickens had average value globally higher than the one in Toffo. Correlation coefficients between body live weight and the other body linear measurements were high and significant. Three groups of chicken emerge: those with yellow beak and those with black beak met in Dassa district and those with cream beak and diverse feathers colour observed in Toffo district. Results also show that 52.58 % of chicken breeders are female and for 71.13 % of them, poultry contributes about 40-100 % to their annual income. The breeders in Toffo had a higher chicken stock and this supports the hypothesis that “lower land owners keep more chickens”. Chicken are raised for rituals uses, market and consumption. Local chicken are appreciated for two purposes: eggs and meat production. The selection criteria are based on the hen’s prolificity and its live weight. Hens reached their sexual maturity between 24 and 26 weeks of age. [less ▲]

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See detailRéformer le budget, changer l'Europe
Gangloff, Camille; Grandjean, Geoffrey ULg; Mancini, Francesca et al

Report (2008)

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See detailThree-dimensional analysis of oceanographic data with the software DIVA
Troupin, Charles ULg; Ouberdous, Mohamed ULg; Machín, Francisco et al

Poster (2008, April 13)

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See detailOn-line respiratory mechanics in newborns: stability and effect of ventilatory mode.
Rigo, Vincent ULg; Rigo, Jacques ULg

in Berger, Th. (Ed.) 9th EPNV Final Program and Abstracts (2008, April 11)

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See detailEffets de la qualité des données sur la courbe d'apprentissage des forêts aléatoires
Brostaux, Yves ULg

Scientific conference (2008, April 11)

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See detailScreening for chronic kidney disease and other associated risk factors in rural congolese oil company in the Democratic Republic of Congo (DRC).
Sumaili, Ernest; Zinga, Chantal; Nseka, Nazaire et al

Poster (2008, April 10)

This study indicates that CKD and traditional risk factors for CKD are very prevalent in this rural Oil Company. Screenings for these conditions are thus imperative to put high on the health agenda ... [more ▼]

This study indicates that CKD and traditional risk factors for CKD are very prevalent in this rural Oil Company. Screenings for these conditions are thus imperative to put high on the health agenda. Additional studies are needed of the causes of CKD in this company and probably in other areas of the DRC. [less ▲]

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See detailSynthesis of novel functional aliphatic polyesters by association of ring-opening polymerization and click chemistry
Lecomte, Philippe ULg; Schmeits, Stephanie ULg; Riva, Raphaël ULg et al

Conference (2008, April 09)

Nowadays, biodegradable and biocompatible aliphatic polyesters are widely used as environmentally friendly thermoplastics and biomaterials. Nevertheless, the absence of any functional group along the ... [more ▼]

Nowadays, biodegradable and biocompatible aliphatic polyesters are widely used as environmentally friendly thermoplastics and biomaterials. Nevertheless, the absence of any functional group along the chain is a severe limitation for the development of new applications. Very recently, it was reported by Emrick et al. and by us that copper(I)-mediated 1,3-dipolar Huisgen's cycloaddition of alkynes and azides, the most widely used “click” reaction in the frame of macromolecular engineering, is very efficient to derivatize aliphatic polyesters. Due to the tolerance for many functional groups, cumbersome protection and deprotection steps are not needed. One main advantage of copper(I)-mediated Huisgen's cycloaddition compared to other reactions previously used to derivatize aliphatic polyesters relies on the mildness of the experimental conditions, which results in limited degradation. Our most recent results dealing with the combination of “click” chemistry and ring-opening polymerization towards functional PCL and PLA, networks, graft and hyperbranched copolymers will be highlighted. [less ▲]

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