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See detailGenèse, évolution et multiples facettes d'une maladie inhabituelle affectant le hêtre en région wallonne
Huart, Olivier; Rondeux, Jacques ULg

in Forêt Wallonne (2001), 52

Les hêtraies wallonnes, principalement situées en Ardenne et en Gaume, sont victimes depuis près de 2 ans d'un problème sanitaire dont l'incidence au plan sylvicole et économique apparaît réellement ... [more ▼]

Les hêtraies wallonnes, principalement situées en Ardenne et en Gaume, sont victimes depuis près de 2 ans d'un problème sanitaire dont l'incidence au plan sylvicole et économique apparaît réellement catastrophique depuis le début de l'année 2001. Une recherche entamée mi-2000 a permis d'effectuer de très nombreuses observations et d'émettre diverses hypothèses quant à l'origine et au processus de développement d'une maladie mettant en jeu des champignons lignivores et des insectes ravageurs du bois. Cette recherche entre aujourd'hui dans sa seconde phase destinée non seulement à assurer le suivi méthodique de la maladie mais aussi à vérifier le bien-fondé des principales hypothèses émises concernant son origine et à cerner les mécanismes de propagation d'insectes dont les attaques n'ont cessé de croître depuis mars 2001. Ces attaques massives ont justifié la mise en place d'actions de recherche complémentaires et plus ciblées destinées à mieux comprendre la biologie des insectes incriminés et de proposer des moyens de lutte appropriés. Dans les lignes qui suivent nous présentons, sur la base d'observations menées depuis 10 mois, une analyse relativement fouillée de la situation en abordant successivement : l'historique de cette maladie, sa distribution, les symptômes les plus fréquemment observés ainsi que les agents causals, les axes prioritaires des recherches en cours, les conséquences tant économiques que sylvicoles et écologiques, et enfin les principaux moyens de lutte envisageable, compte tenu de l'état actuel des connaissances. [less ▲]

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See detailGenesis and organisation of surface horizons of deserts soils. Influence on soil management and classification
Souirji, A.; Marcoen, Jean Marie ULg

in Genesis and organisation of surface horizons of deserts soils. Influence on soil management and classification (1998)

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See detailGenesis of active and inactive species during the preparation of MoO3/SiO2-Al2O3 metathesis catalysts via wet impregnation
Debecker, D. P.; Stoyanova, M.; Rodemerck, U. et al

in Catalysis Today (2011), 169(1), 60-68

The wet impregnation of ammonium heptamolybdate onto silica-alumina is used to prepare MoO3/SiO2-Al2O3 heterogeneous metathesis catalysts. The preparation is inspected in details in conjunction with ... [more ▼]

The wet impregnation of ammonium heptamolybdate onto silica-alumina is used to prepare MoO3/SiO2-Al2O3 heterogeneous metathesis catalysts. The preparation is inspected in details in conjunction with physico-chemical characterization tools with the aim to identify the parameters that dictate the genesis of active and inactive metathesis species. The effects of the MoO3 loading and of the calcination temperature are systematically explored. The samples are characterized by N2-physisorption, ICP-AES, XRD, Raman, 27Al MAS-NMR and XPS and evaluated in the metathesis of propene to butene and ethene. Particular attention is brought to the interaction of the mesoporous silica-alumina support with the active component, to the decomposition of the precursor salt and to the location of the molybdenum oxide phase with respect to the pores of the support. It is shown that the temperature of calcination influences markedly the performances of the catalyst. High temperature treatments are necessary to decompose efficiently the Mo salt precursor. In the metathesis of propylene, the performances are levelling off when the MoO 3 loading is increased above ∼8 wt.%. This effect is correlated to the build up of MoO 3 crystals and of Al2(MoO4)3 at relatively high loading. © 2010 Elsevier B.V. All rights reserved. [less ▲]

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See detailGenesis of clone size heterogeneity in megakaryocytic and other hemopoietic colonies: the stochastic model revisited
Paulus, Jean-Michel ULg; Levin, Jack; Debili, Najet et al

in International Society for Experimental Hematology (2001), 29(nd), 1256-69

OBJECTIVE: We previously showed that the distributions of the numbers of doublings (NbD) undergone by individual megakaryocyte progenitors before commitment to polyploidization are markedly skewed and can ... [more ▼]

OBJECTIVE: We previously showed that the distributions of the numbers of doublings (NbD) undergone by individual megakaryocyte progenitors before commitment to polyploidization are markedly skewed and can consistently be fitted to straight lines when plotted on semilogarithmic coordinates. The slope of such lines, which yields the probability of polyploidization per doubling, is made less steep by stimulators of megakaryocyte colony formation and is less steep in mixed erythroid-megakaryocyte than in pure megakaryocyte colonies. Therefore, megakaryocytopoiesis provides a unique model for the study of clonal heterogeneity in a hemopoietic lineage, which is the subject of this review. DATA SOURCES: Articles relevant to the interpretation of these data were selected from the authors' and public databases. DATA SYNTHESIS: Exponential NbD distributions were first explained by postulating that following the assembly of thrombopoiesis-specific regulators, megakaryocyte progenitors require only a single random event to arrest proliferation and commit to polyploidization. However, this stochastic model was refuted by data indicating that intrinsic properties of individual progenitors affect the NbD they achieve. We suggest that the unequal repartition of critical compounds (including receptors, signaling molecules, and gene regulators) inherent in the stem cell-progenitor transition causes a heritable heterogeneity in megakaryocyte progenitor responsiveness to polyploidization inducers. This model would be compatible with 1) the evidence for intraclonal synchronization in megakaryocyte and other hemopoietic clones generated by committed progenitors; 2) the low probability of polyploidization of the relatively insensitive bipotent megakaryocyte progenitors; and 3) the thesis that stimulators act in part by recruiting megakaryocyte progenitor cells endowed with lesser responsiveness to polyploidization inducers and higher proliferative potential. CONCLUSION: The responsiveness of individual megakaryocyte progenitors to polyploidization inducers may be a major determinant of the exponential shape of NbD distributions. [less ▲]

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See detailGenesis of gray monazites : evidences from the Paleozoïc of Belgium
Burnotte, Etienne; Pirard, Eric ULg; Michel, Gilbert

in Economic Geology (1989), 84

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See detailGenesis of intermediate to silicic igneous rocks at the end of the Sveconorwegian (grenvillian) orogeny
Vander Auwera, Jacqueline ULg; Bogaerts, M.; Bolle, Olivier ULg

in Geochimica et Cosmochimica Acta (2007, August), 71(15S), 1054

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See detailThe genesis of platelet volume and density distributions
Paulus, Jean-Michel ULg; Sequaris, Marianne; Graas, D. et al

in Martin, John; Trowbridge, Anthony (Eds.) Platelet Heterogeneity: Biology and Pathology (1988, April)

A discussion by 28 authors of the factors determining platelet heterogeneity in man and mammals

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See detailGENESTAT: an information portal for design and analysis of genetic association studies
Ripatti, Samuli; Becker, Tim; Bickeboller, Heike et al

in European Journal of Human Genetics (2009), 17(4), 533-6

We present the rationale, the background and the structure for version 2.0 of the GENESTAT information portal (www.genestat.org) for statistical genetics. The fast methodological advances, coupled with a ... [more ▼]

We present the rationale, the background and the structure for version 2.0 of the GENESTAT information portal (www.genestat.org) for statistical genetics. The fast methodological advances, coupled with a range of standalone software, makes it difficult for expert as well as non-expert users to orientate when designing and analysing their genetic studies. The ultimate ambition of GENESTAT is to guide on statistical methodology related to the broad spectrum of research in genetic epidemiology. GENESTAT 2.0 focuses on genetic association studies. Each entry provides a summary of a topic and gives links to key papers, websites and software. The flexibility of the internet is utilised for cross-referencing and for open editing. This paper gives an overview of GENESTAT and gives short introductions to the current main topics in GENESTAT, with additional entries on the website. Methods and software developers are invited to contribute to the portal, which is powered by a Wikipedia-type engine and allows easy additions and editing. [less ▲]

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See detailThe genetic absence epilepsy rat from Strasbourg (GAERS), a rat model of absence epilepsy: Computer modeling and differential gene expression
Lakaye, Bernard ULg; Thomas, E.; Minet, Arlette ULg et al

in Epilepsia (2002), 43(Suppl. 5), 123-129

Purpose: We present results obtained by computer modeling of the thalamic network and differential gene expression analysis in a rat strain with absence epilepsy, the genetic absence epilepsy rat from ... [more ▼]

Purpose: We present results obtained by computer modeling of the thalamic network and differential gene expression analysis in a rat strain with absence epilepsy, the genetic absence epilepsy rat from Strasbourg (GAERS). Methods: (a) Computer modeling used equations from the Hodgking-Huxley model with a circuit of 13 reticular thalamic (nRt) and 39 thalamocortical (TC) neurons; (b) gene-expression analysis using differential mRNA display (DD), in situ hybridization, Northern blotting, and competitive reverse transcriptase-polymerase chain reaction (RT-PCR). Results: (a) Computer modeling showed an increased network synchrony in the thalamic circuit as the value of conductance of low-voltage activated calcium channel (LVACC) is increased. (b) Using differential mRNA display, a 40% upregulation of the H-ferritin mRNA in the hippocampus was demonstrated. Looking for some candidate genes of the VACC family, no difference was found in the alpha1G mRNA expression between GAERS and control animals, whereas a decreased expression of the alpha1E subunit was observed in the cerebellum and the brainstem of the GAERS. This phenomenon was not observed in young animals when the epileptic phenotype is not expressed. Conclusions: The use of computer modeling appeared to be an efficient way to evaluate the impacts of electrophysiologic findings in vivo from single cells on an entire circuit. No clear single gene defect was revealed so far in GAERS. More information could arise from linkage analysis. However, some brain structures like hippocampus or cerebellum classically not known to be involved in the production of absence spike-and-wave discharges could in fact participate in the development of this phenotype. [less ▲]

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See detailGenetic algorithm for the design of electro-mechanical sigma delta modulator MEMS sensors
Wilcock, Reuben; Kraft, Michaël ULg

in Sensors (2011), 11(10), 9217--9238

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See detailGenetic algorithm optimisation of transient two-phase water pressures inside closed-end rock joints
Bollaert, Erik; Erpicum, Sébastien ULg; Pirotton, Michel ULg et al

in Schleiss, Anton; Bollaert, Erik (Eds.) Rock Scour due to falling high-velocity jets (2002)

High-velocity plunging water jets, appearing at the downstream end of dam weirs and spillways, can create scour of the rock. The prediction of this scour is necessary to ensure the safety of the toe of ... [more ▼]

High-velocity plunging water jets, appearing at the downstream end of dam weirs and spillways, can create scour of the rock. The prediction of this scour is necessary to ensure the safety of the toe of the dam as well as the stability of its abutments. A physically based engineering model has been developed at the Laboratory of Hydraulic Constructions for evaluation of the ultimate scour depth. This model is based on experimental measurements of water pressures at plunge pool bottoms and inside underlying rock joints. The pressures inside the joints revealed to be of highly transient nature and governed by the presence of free air. Hence, a numerical modelling of these pressures was performed, in collaboration with the Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH), based on the one-dimensional transient flow equations applied to a pseudo-fluid. The amount of free air is a function of the instantaneous pressure inside the joint and has been accounted for by means of appropriate celerity-pressure relationships. These relationships are defined by the ideal gas law and Henry’s law and were optimised by means of a genetic algorithm optimisation technique. Very good agreement has been obtained between the measured and computed pressures at the end location of one-dimensional closed-end rock joints. [less ▲]

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See detailGenetic analysis in young patients with sporadic pituitary macroadenomas:Beside AIP don't forget MEN1 genetic analysis.
Cuny, Thomas; Pertuit, Morgane; Sahnoun-Fathallah, Mouna et al

in European Journal of Endocrinology (2013)

CONTEXT: germline mutations in the AIP gene have been identified in young patients (age </= 30 years old) with sporadic pituitary macroadenomas. Otherwise, there are few data concerning the prevalence of ... [more ▼]

CONTEXT: germline mutations in the AIP gene have been identified in young patients (age </= 30 years old) with sporadic pituitary macroadenomas. Otherwise, there are few data concerning the prevalence of MEN1 mutations in such population. OBJECTIVE: We assessed the prevalence of both AIP and MEN1 genetic abnormalities (mutations and large gene deletions) in young patients (age </= 30 years old) diagnosed with sporadic and isolated macroadenoma, without hypercalcemia and/or MEN1-associated lesions. DESIGN: The entire coding sequences of AIP and MEN1 were screened for mutations. In cases of negative sequencing screening, multiplex ligation-dependent probe amplification was performed for the detection of large genetic deletions. PATIENTS AND SETTINGS: 174 patients from Endocrinology Departments of 15 French University Hospital Centers were eligible for this study. RESULTS: 21/174(12%) patients had AIP (n=15, 8.6%) or MEN1 (n=6, 3.4%) mutations. In pediatric patients (age </= 18 years old), AIP/MEN1 mutation frequency reached nearly 22% (n=10/46). AIPmut and MEN1mut were respectively identified in 8/79 (10.1%) and 1/79 (1.2%) somatotropinoma patients; they each accounted for 4/74 (5.4%) prolactinoma patients with mutations. Half of patients (n=3/6) with gigantism displayed mutations in AIP. Interestingly, 4/12 (33%) patients with non-secreting adenomas bore either AIP or MEN1 mutations, whereas none of the 8 corticotroph-adenomas and a single thyrotropinoma case had mutations. No large gene deletions were observed in sequencing-negative patients. CONCLUSION: mutations in MEN1 can be of significance in young patients with sporadic isolated pituitary macroadenomas, particularly prolactinomas, and together with AIP, we suggest genetic analysis of MEN1 in such population. [less ▲]

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See detailGenetic analysis of a glomerulonephropathy segregating in a pedigree of French Mastiff.
Battaille, Géraldine ULg; Lavoué, Rachel ULg; Peeters, Dominique ULg et al

in Proceedings of 32nd Annual Conference of the International Society of Animal Genetics (2010)

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See detailGenetic analysis of heat stress effects on yield traits, udder health, and fatty acids of Walloon Holstein cows
Hammami, Hedi ULg; Vandenplas, Jérémie; Vanrobays, Marie-Laure ULg et al

in Journal of Dairy Science (2015), 98(7), 4956-4968

Genetic parameters that considered tolerance for heat stress were estimated for production, udder health, and milk composition traits. Data included 202,733 test-day records for milk, fat, and protein ... [more ▼]

Genetic parameters that considered tolerance for heat stress were estimated for production, udder health, and milk composition traits. Data included 202,733 test-day records for milk, fat, and protein yields, fat and protein percentages, somatic cell score (SCS), 10 individual milk fatty acids (FA) predicted by mid-infrared spectrometry, and 7 FA groups. Data were from 34,468 first-lactation Holstein cows in 862 herds in the Walloon region of Belgium and were collected between 2007 and 2010. Test-day records were merged with daily temperature-humidity index (THI) values based on meteorological records from public weather stations. The maximum distance between each farm and its corresponding weather station was 21km. Linear reaction norm models were used to estimate the intercept and slope responses of 23 traits to increasing THI values. Most yield and FA traits had phenotypic and genetic declines as THI increased, whereas SCS, C18:0, C18:1 cis-9, and 4 FA groups (unsaturated FA, monounsaturated FA, polyunsaturated FA, and long-chain FA) increased with THI. Moreover, the latter traits had the largest slope-to-intercept genetic variance ratios, which indicate that they are more affected by heat stress at high THI levels. Estimates of genetic correlations within trait between cold and hot environments were generally high (>0.80). However, lower estimates (< = 0.67) were found for SCS, fat yield, and C18:1 cis-9, indicating that animals with the highest genetic merit for those traits in cold environments do not necessarily have the highest genetic merit for the same traits in hot environments. Among all traits, C18:1 cis-9 was the most sensitive to heat stress. As this trait is known to reflect body reserve mobilization, using its variations under hot conditions could be a very affordable milk biomarker of heat stress for dairy cattle expressing the equilibrium between intake and mobilization under warm conditions. [less ▲]

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