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See detailPrediction of daily milk, fat, and protein production by a random regression test-day model
Mayeres, P.; Stoll, J.; Bormann, J. et al

in Journal of Dairy Science (2004), 87(6), 1925-1933

Test-day genetic evaluation models have many advantages compared with those based on 305-d lactations; however, the possible use of test-day model (TDM) results for herd management purposes has not been ... [more ▼]

Test-day genetic evaluation models have many advantages compared with those based on 305-d lactations; however, the possible use of test-day model (TDM) results for herd management purposes has not been emphasized. The aim of this paper was to study the ability of a TDM to predict production for the next test day and for the entire lactation. Predictions of future production and detection of outliers are important factors for herd management (e. g., detection of health and management problems and compliance with quota). Because it is not possible to predict the herd-test-day (HTD) effect per se, the fixed HTD effect was split into 3 new effects: a fixed herd-test month-period effect, a fixed herd-year effect, and a random HTD effect. These new effects allow the prediction of future production for improvement of herd management. Predicted test-day yields were compared with observed yields, and the mean prediction error computed across herds was found to be close to zero. Predictions of performance records at the herd level were even more precise. Discarding herds enrolled in milk recording for <1 yr and animals with very few tests in the evaluation file improved correlations between predicted and observed yields at the next test day (correlation of 0.864 for milk in first-lactation cows as compared with a correlation of 0.821 with no records eliminated). Correlations with the observed 305-d production ranged from 0.575 to 1 for predictions based on 0 to 10 test-day records, respectively. Similar results were found for second and third lactation records for milk and milk components. These findings demonstrate the predictive ability of a TDM. [less ▲]

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See detailRéseaux de surveillance des masses d’eau souterraine en Région Wallonne
Rentier, Céline; Delloye, Francis; Dassargues, Alain ULg

in Tribune de l'Eau (La) (2004), (631-632), 11-21

La mise en œuvre de la directive européenne cadre de l’eau nécessite l’élaboration, par masse d’eau souterraine, d’un réseau de mesure et de surveillance aussi représentatif que possible de l’état des ... [more ▼]

La mise en œuvre de la directive européenne cadre de l’eau nécessite l’élaboration, par masse d’eau souterraine, d’un réseau de mesure et de surveillance aussi représentatif que possible de l’état des eaux souterraines. En Région Wallonne, cinq masses d’eau de caractéristiques différentes d’un point de vue géologique, hydrogéologique et d’occupation du sol ont fait l’objet d’une étude en vue d’établir une stratégie de sélection des sites de mesures. La sélection des stations de mesure composant chaque réseau a été réalisé en tenant compte de divers critères tels que la géologie, l’hydrogéologie et l’hydrochimie de la masse d’eau, les caractéristiques des points d’eau existants, mais aussi la densité et la répartition spatiale des ouvrages sélectionnés. Le système d’évaluation de la qualité des eaux souterraines SEQESO adopté en Région Wallonne a été appliqué à chacun de ces réseaux afin d’apprécier l’état chimique de ces masses d’eaux conformément à la directive-cadre. The implementation of the European water framework directive requires the construction of monitoring networks being as far as possible representative of the global water quality in each groundwater body. In Walloon Region, five groundwater bodies with different contrasted geological conditions, hydrogeological conditions and soil occupancy, were studied in order to establish an approach for choosing an adequate network of monitoring points. This selection was realized by considering different criterions as the groundwater geology, hydrogeology and hydrochemistry, the feature of existing waterpoints, but also the density and the spatial distribution of the selected points in order to obtain a statistically representative network. The quality assessment system for groundwater (SEQESO) adopted by the Walloon Region has been applied to the five monitoring networks in order to fully appreciate the chemical status of the groundwater bodies in accordance with the European directive. [less ▲]

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See detailAggregated indicators from an optimized groundwater monitoring network: example in Walloon region of Belgium for implementation of the European Water Directive
Rentier, Céline; Delloye, Francis; Brouyère, Serge ULg et al

in Proc. of Integrated methods for assessing water quality, COST629 Workshop (2004)

Following prescriptions of the recent European Water Framework Directive, a groundwater quality evaluation system must be adopted for checking the groundwater status with respect to different contaminants ... [more ▼]

Following prescriptions of the recent European Water Framework Directive, a groundwater quality evaluation system must be adopted for checking the groundwater status with respect to different contaminants. A screening evaluation system (based on a system developed by the French Water Agencies) has been adapted to the specific conditions in the Walloon Region of Belgium. Groundwater quality data are aggregated into indicators with respect to different water uses such as drinking water standards, thresholds values for preserving dependent surface ecosystems, or the groundwater ‘natural or patrimonial state’. A global groundwater quality indicator can also be calculated. Different aggregation techniques are discussed with their respective influence on the final indicator. In relation to this evaluation, the monitoring network must be adapted for being (as far as possible) representative of the global quality of water in each groundwater body. Existing knowledge and understanding of the actual hydrogeological conditions were used in priority for choosing an adequate network of monitoring points. At the same time, the spatial density of points was checked in order to obtain a statistically representative network. Applications were performed in five different GWBodies belonging to the hydrographic district of the Meuse River in the Walloon Region and with different contrasted geological conditions: Cretaceous chalks, Carboniferous limestones and Pleistocene gravels of the alluvial plain of the River Meuse. These examples provide a good opportunity for further discussion and work about the main related issues: optimzation procedures, aggregation methods and estimation of the reliability of indicators. [less ▲]

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See detailLa pédagogie universitaire en mouvement : une stratégie en 7 clés méthodologiques et enrichissement continu pour une mise en action de compétences et un impact pratique immédiat
Poumay, Marianne ULg

in (Re)trouver le plaisir d'enseigner et d'apprendre. Construire savoirs et compétences. (2004)

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See detailCatalogue des papyrus iatromagiques grecs
de Haro Sanchez, Magali ULg

in Papyrologica Lupiensia (2004), 13

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See detailBois de feu et déboisement au Sahel: mise au point
Ozer, Pierre ULg

in Science et changements planétaires / Sécheresse (2004), 15(3), 243-251

A major environmental issue of the XXIst century, deforestation due to firewood consummation is an increasing problem within the Sahel of West Africa. This article underlines the difficulties to obtain ... [more ▼]

A major environmental issue of the XXIst century, deforestation due to firewood consummation is an increasing problem within the Sahel of West Africa. This article underlines the difficulties to obtain reliable statistics to correctly monitor deforestation. Field data on firewood consumption are dramatically lacking and inventories of forest cover are very poor. In this context, scientists and policymakers often use the data published by FAO to understand the deforestation topic. Unfortunately, we clearly demonstrate that those data are also inaccurate and not coherent. The analysis of several official documents shows that no institution is currently able to produce any reliable data on firewood and its impact on the environment. [less ▲]

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See detailAnalyse de la campagne agricole 2003 en terme de stress hydrique
De Longueville, Florence ULg; Horion, Stéphanie ULg; Tychon, Bernard ULg et al

in Bulletin de la Société Géographique de Liège (2004), 44

This article presents the evaluation of the crop water stress in 2003 using the Belgian Crop Growth Monitoring System (B-CGMS). The indicator used is the Relative Soil Moisture Index (RSMI), and is based ... [more ▼]

This article presents the evaluation of the crop water stress in 2003 using the Belgian Crop Growth Monitoring System (B-CGMS). The indicator used is the Relative Soil Moisture Index (RSMI), and is based on a calculation integrating soil moisture data. This index shows the differences between needed and effectively available soil water for different crop types. It is one of the outputs of the B-CGMS agrometeorological model. Based on a fixed threshold, days affected by water stress have been identified and computed for specific periods during which lack of soil water is likely to have dramatic impacts on crop production. The cumulative number of days affected by water stress indicator has then been integrated into a GIS to spatially represent the situation of winter wheat and maize during the 2003 crop season. Results suggest that only maize was affected by the water stress in northern and southern Belgium. In the latter area, the lack of water at key periods provoked a yield reduction ranging between 2 and 50%. [less ▲]

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See detailUtilisation de la visibilité horizontale pour l’estimation de la qualité de l’air à Niamey, Niger
Ozer, Pierre ULg

in Bulletin de la Société Géographique de Liège (2004), 44

It is now irrefutable that air pollution caused by large amounts of Total Suspended Particulates (TSP) has numerous undesired consequences on human health. Air quality deterioration in the US and in ... [more ▼]

It is now irrefutable that air pollution caused by large amounts of Total Suspended Particulates (TSP) has numerous undesired consequences on human health. Air quality deterioration in the US and in Europe caused by high concentration of African dust is seen as a major health threat although most of these countries are very distant from the Sahara. Surprisingly, no estimates of TSP levels near the Saharan dust source are available. Based on horizontal visibility measurements reduced by dust in the air, TSP levels are estimated at Niamey-Aéroport (Niger) by using different relations found in the literature. It appears that excessive TSP concentration levels are very important in magnitude and frequency. These very high TSP levels represent a tremendous public health threat that should be absolutely taken into consideration by national and international decision makers. [less ▲]

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See detailMassive binaries and colliding winds
Rauw, Grégor ULg

in EAS Publications Series (2004)

In this contribution, I review recent results from observational investigations of early-type binaries of spectral types O and Wolf-Rayet. These studies aim at an accurate determination of fundamental ... [more ▼]

In this contribution, I review recent results from observational investigations of early-type binaries of spectral types O and Wolf-Rayet. These studies aim at an accurate determination of fundamental parameters such as masses and radii of the most massive stars. In addition, multi-wavelength analyses of wind collisions in massive binaries provide constraints on the properties of stellar winds of massive stars and shock physics of cosmic plasmas. [less ▲]

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See detailRecommandations de l'ESH-ESC 2003 pour la prise en charge de l'hypertension artérielle en médecine générale
Persu, Alexandre; Krzesinski, Jean-Marie ULg; Van de Borne, Philippe

in Revue Médicale de Liège (2004), 59(9), 489-496

Guidelines for the management of arterial hypertension are regularly updated. This article summarizes the last international guidelines in this field published last year. The decision to initiate an ... [more ▼]

Guidelines for the management of arterial hypertension are regularly updated. This article summarizes the last international guidelines in this field published last year. The decision to initiate an antihypertensive treatment will not only depend on blood pressure [less ▲]

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See detailMR2048151, Sergeev, Y. A. and Swailes, D. C. and Petrie, C. J. S., Stability of uniform fluidization revisited; Physica A
Rochus, Pierre ULg

in Mathematical Reviews [=MR] (2004), 335(1-2), 9--34

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See detailDevelopment of RT-PCR assays using fluorogenic 3 minor groove binder DNA probes for detection of fruit tree viruses.
Marbot, Sophie; Kummert, Jean; Vendrame, Marina et al

in Acta Horticulturae (2004), (657), 547-551

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See detailEffect Of Pig Bodyweight On Ileal Amino Acid Endogenous Losses After Ingestion Of A Protein-Free Diet Enriched In Pea Inner Fibre Isolates
Leterme, Pascal; Thewis, André ULg

in Reproduction Nutrition Development (2004), 44(5), 407-417

The present study was conducted to evaluate whether bodyweight and the micronisation of dietary fibre affect the endogenous nitrogen and amino acid losses (ENL and EAAL) in pigs. The effect of the ... [more ▼]

The present study was conducted to evaluate whether bodyweight and the micronisation of dietary fibre affect the endogenous nitrogen and amino acid losses (ENL and EAAL) in pigs. The effect of the micronising process was tested by providing pigs with 90 g DM·kg–1 BW0.75 of a N-free diet supplemented with isolated pea inner fibres, presented in native or micronised form and with a water-holding capacity of 12 and 4 g water·g–1 DM, respectively. ENL and EAAL were measured on pigs weighing 24, 62 and 105 kg. In all cases, daily ENL increased linearly (P < 0.05) with BW, for the majority of the AA and total N. As BW increased, daily ENL, total EAAL and the majority of EAAL increased linearly independently of micronisation (P < 0.05). When expressed per kg DMI, total EAAL and the majority of each EAA decreased curvilinearly and reached nadir at around 100 kg BW. For ENL expressed per kg DMI, micronisation resulted in a curvilinear decrease with increasing BW, as compared to a linear decrease for pigs fed the native pea fibre diet (non-micronised). Micronisation of pea inner fibres did not decrease ENL or EAAL daily, except for proline. When the losses were expressed as g·k–1g DMI, micronisation did not decrease ENL but decreased (P < 0.05) endogenous losses for a majority of AA as well as for total AA. The results suggest that small pigs excrete more endogenous N per kg DMI than large pigs and that pea fibre micronisation reduces EAAL but not ENL when expressed per kg DMI. [less ▲]

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See detailImprovement Of Spray Deposit Homogeneity Using A Pwm Spray Controller To Compensate Horizontal Boom Speed Variations
Lebeau, Frédéric ULg; El Bahir, L.; Destain, Marie-France ULg et al

in Computers and Electronics In Agriculture (2004), 43(2),

Longitudinal spray distribution is mainly affected by the horizontal speed variations of the nozzles. Manufacturers classically try to reduce unwanted nozzles movements using horizontal boom suspension ... [more ▼]

Longitudinal spray distribution is mainly affected by the horizontal speed variations of the nozzles. Manufacturers classically try to reduce unwanted nozzles movements using horizontal boom suspension but these methods have performance and price limitations. This paper describes a spray controller aiming to compensate the effect of the horizontal boom movements on the spray deposits homogeneity. The controller is based on three main components: a control law describing the relationship between nozzle speed, nozzle flow and spray deposit; a real time measurement of the boom horizontal speed variations using micro-machined capacitive accelerometers, and pulse width modulation (PWM) nozzle flow actuators. To assess the feasibility of such a controller, a single nozzle prototype was developed and tested in the laboratory, using a nigrosine solution. Spray coverage was measured using image analysis for field representative nozzle speed variations. The spray coverage uniformity using the controller showed about 51% compensation of the variations observed without it. [less ▲]

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See detailModelling The Dynamic Distribution Of Spray Deposits
Lebeau, Frédéric ULg

in Biosystems Engineering (2004), 89(3),

A mathematical model to estimate the spray distribution of phytopharmaceutical deposits under a spray boom is proposed. It focuses on the need to take account of the dynamic effects of the forward ... [more ▼]

A mathematical model to estimate the spray distribution of phytopharmaceutical deposits under a spray boom is proposed. It focuses on the need to take account of the dynamic effects of the forward movement of the boom. These are related both to the horizontal and vertical boom movement and to the influence of aerodynamic factors on the nozzle spray distribution. The distribution of the spray deposits is computed by multiplying the nozzle spray pattern by the time needed to move from one position to the next. Mathematically, this is expressed by a convolution of the trajectory function with the nozzle spray pattern function. The model is validated through a dynamic test bench to reproduce the boom movements observed in the field. The chosen method to measure the distribution of the spray deposits is a chemical dosage of the sprayed potassium chloride (KCl) solution collected in Petri dishes. A pulse-width modulation (PWM) nozzle body fitted on the test bench is used to generate a dynamic distribution of spray deposits from which the dynamic two-dimensional nozzle spray pattern is reconstructed. This dynamic nozzle spray pattern introduced in the model allows a far better estimation of the spray deposit distribution to be made than the one obtained using the static nozzle spray pattern which was computed using filtered back-projection. [less ▲]

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See detailLe bilan azoté dans les exploitations porcines wallonnes : entre contraintes environnementales et qualité différenciée.
Degre, Aurore ULg; Verheve, Didier; Debouche, Charles ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2004), 8(2), 119-124

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See detailLe verrat, la truie: Aspects techniques de la reproduction
Feller, Didier; Thilmant, Pierre; Wavreille, José et al

Book published by FPW - Edition 2004 (2004)

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See detailDes socles de compétences à la mise en place d'une démarche expérimentale à l'école primaire : intervention en formation initiale des enseignants
Hindryckx, Marie-Noëlle ULg; Stegen, Pierre; Graftiau, Marie-Christine et al

in Herphelin, Martine (Ed.) Actes du troisième congrès des chercheurs en éducation : (re)trouver le plaisir d'enseigner et d 'apprendre; construire savoirs et compétences (2004)

Dans le cadre de ce projet de recherche-action, une collaboration étroite entre deux services universitaires de Liège (Service de Didactique générale , faculté de Psychopédagogie et service de Chimie ... [more ▼]

Dans le cadre de ce projet de recherche-action, une collaboration étroite entre deux services universitaires de Liège (Service de Didactique générale , faculté de Psychopédagogie et service de Chimie organique - faculté des Sciences) et la Haute École Charlemagne (Liège et Huy) s’est mise en place pendant trois ans. La question centrale qui a guidé le travail durant ces trois années est : « Comment incorporer, dans le curriculum de formation des futurs instituteurs, des mises en situation favorisant le développement de leur capacité à construire des activités d’apprentissages faisant intervenir des démarches expérimentales telles que présentées dans le document « Socles de compétences » ? ». L’objet de la collaboration entre les différents partenaires concernés a été la construction d’un outil de formation prenant place dans les ateliers de formation professionnelle (AFP) des futurs enseignants. Cet outil de formation a pris la forme d’un module qui s’est articulé sur une démarche en trois temps : • Faire vivre aux futurs enseignants une démarche de recherche expérimentale concrète, au départ d’une énigme scientifique à leur niveau ; • Prendre du recul face au vécu pour faire identifier par les stagiaires les fondements didactiques de la démarche de formation et prolonger cette réflexion métacognitive par des moments de théorisation sur les contenus visés ; • Construire ensemble des séquences de leçons mettant en place une démarche expérimentale et les tester dans des classes du primaire Ce dispositif a été testé à cinq reprises, dans des situations différentes, à la Haute École Charlemagne dans les implantations de Liège et de Huy. Un document en cinq volumes constitue le rapport final qui clôture les trois années de recherche pour l’AGERS. Il est construit comme un outil destiné aux enseignants des Hautes Ecoles (psychopédagogues et/ou professeur de sciences) ainsi qu’aux maîtres de formation pratique. [less ▲]

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See detailBridges across Chasms: Towards a Transcultural Future in Caribbean Literature
Ledent, Bénédicte ULg

Book published by L3 (Liège Language and Literature) (2004)

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