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See detailcatR: an R package for computerized adaptive testing
Magis, David ULg; Raîche, Gilles

in Applied Psychological Measurement (2011), 35

Computerized adaptive testing (CAT) is an active current research field in psychometrics and educational measurement. However, there is very little software available to handle such adaptive tasks. The R ... [more ▼]

Computerized adaptive testing (CAT) is an active current research field in psychometrics and educational measurement. However, there is very little software available to handle such adaptive tasks. The R package catR was developed to perform adaptive testing with as much flexibility as possible, in an attempt to provide a developmental and testing platform to the interested user. Several item-selection rules and ability estimators are implemented. The item bank can be provided by the user or randomly generated from parent distributions of item parameters. Three stopping rules are available. The output can be graphically displayed. [less ▲]

Detailed reference viewed: 48 (8 ULg)
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See detailCattedrale e collegiali di Liegi
Corswarem, Emilie ULg

Conference (2006, December 07)

Detailed reference viewed: 22 (1 ULg)
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See detailCattle enterotoxaemia and Clostridium perfringens: description, diagnosis and prophylaxis
Lebrun, M.; Mainil, Jacques ULg; Linden, Annick ULg

in Veterinary Record : Journal of the British Veterinary Association (2010), 167(1), 13-22

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See detailCattle grazing dynamics under contrasted pasture characteristics at temporal and spatial scales
Andriamandroso, Andriamasinoro ULg

Doctoral thesis (2017)

Grassland constitutes an important and a low-cost food source for grazing livestock. Optimal management should consider both forage resource productivity and animal needs. For cattle, grazing is a normal ... [more ▼]

Grassland constitutes an important and a low-cost food source for grazing livestock. Optimal management should consider both forage resource productivity and animal needs. For cattle, grazing is a normal behavior displayed in an attempt to eat the amount of forage to fulfill their nutritive requirements for maintenance and production. It is the most time-consumed activity of cows reared in pasture-based systems. With the increase of herd size, on one hand, farmers have been constrained to integrate innovative tools and techniques, such as milking robot, to improve the production system in particular to reduce the labor cost. On the other hand, such change might reduce time allocated for grazing on pasture. However pasture-based systems constitute a real pillar for sustainability as they are socially acceptable and environmentally profitable as they play an important role on ecosystem services and biodiversity provision. Studying grazing processes at individual level, which finally is the key point of animal-plant interactions, is a valuable research domain to enhance the knowledge about this mechanism and to feed decision support tools. This thesis aimed to link the changes in pasture characteristics to the grazing behavior of cattle in order to better understand the grazing strategy under different pasture characteristics and forage allowances. To allow an individual monitoring, sensor technology has integrated within farms and livestock researches to monitor many physical variables, inducing the emergence of precision livestock farming approach. Different types of sensors were designed, and already commercialized for some, primarily for physiological status detections such as heat, parturition or diseases. Grazing behaviors could be monitored using pressure, electromyography, acoustic or accelerometric sensors by classifying posture and movements of the animal into unitary behaviors (grazing, ruminating, resting, walking, etc.) and finer behavior such as chews and bites through jaw movements’ detection. When compared to real observation, detection accuracies of these behaviors were variable according to the type of sensor, its position on the animal during data acquisition on pasture, the data recording frequency, the time-window and the method dedicated to the post-recording data analysis. State-of-the-art analysis demonstrated a great performance of accelerometers for unitary behaviors and bites detection. An inertial measurement unit, integrating accelerometer, gyroscope and location sensors, was used for recording cattle movements during grazing at high sampling rate (100Hz). It allows a correct detection of grass intake and rumination behaviors with an average accuracy of 91% using 1-second time-window when calibrating and validating the detection algorithm. Deeper analysis of accelerometric signal allowed us to detect bites and chews performed during grazing and ruminating. Effects of pasture heights on grazing bites characteristics were differentiated by a higher frequency when pasture is at a lower height. Finally when combined to geographical information, a similar pattern was observed for cattle grazing on the same spot confirming their herd movement during grazing in terms of bites location. Differences were visible under different pasture heights but not significant. Such bites location, combined with continuous monitoring of cattle behaviors, through use of sensors, should be furtherly linked with more pasture characteristics, if possible with the same accuracy, and monitored on longer period in order to obtain a complete coverage of cattle grazing strategy and the effect of contrasted environment in order to purpose valuable tool for a better grazing management. [less ▲]

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See detailCattle methane fluxes measurement over an intensively grazed grassland using eddy covariance
Dumortier, Pierre ULg; Aubinet, Marc ULg; Beckers, Yves ULg et al

Poster (2013, September)

Methane emissions account for 8% of the EU-15 GHG emissions and livestock generates approximately half of these emissions (European Commission, 2009). Recent technological advances in spectroscopy now ... [more ▼]

Methane emissions account for 8% of the EU-15 GHG emissions and livestock generates approximately half of these emissions (European Commission, 2009). Recent technological advances in spectroscopy now permit methane flux measurement using eddy covariance. This method has numerous strengths. It can measure fluxes in situ, continuously and across broad areas. This provides information about meadow and cattle emission behaviour throughout the year and across a broad range of climatic conditions. We will present here a one year monitoring of methane exchange between an intensively grazed meadow and the atmosphere obtained using the eddy-covariance method. Methane fluxes exchanged by a grazed meadow were measured continuously since June 2012 at the Dorinne Terrestrial Observatory (50˚ 18’ 44” N; 4˚ 58’ 07” E; 248 m asl.) in Belgium. The site is an intensively pastured meadow of 4.2 ha managed according to the regional common practices where up to 30 Belgian Blue cows are grazing simultaneously. Flux measurements were made with the eddy covariance technique, using a fast CH4 analyzer (Picarro G2311-f) and a sonic anemometer (Campbell Csat3). Carbon dioxide fluxes and various micro-meteorological and soil variables, biomass growth and stocking rate evolution were also measured at the site. Turbulent fluxes were calculated according to standard eddy covariance computation schemes and were filtered for non-stationarity and for low friction velocity (u*) events. During grazing periods, fluxes are dominated by the enteric fermentation source and average 111 nmol m-2 s-1. They are highly variable, probably due to cow movements in and out the measurement footprint and cow digestion rhythm. Despite this spread, a daily emission rhythm is observed with higher emissions during the afternoon. When fluxes are integrated over large periods, methane emissions were found strongly related to cattle stocking rate with a slope of 7.34±0.78 mol CH4 day-1 LSU-1. Further developments are ongoing in order to improve cattle geo-localization through infra-red cameras and individual home-made GPS devices. The two systems will be compared in terms of cost, efficiency and ease of use. During cow-free periods, the methane flux averages 10.5 nmol m-2 s-1 and is highly variable with some production peaks above 100 nmol m-2 s-1. No relation was found between methane fluxes and soil temperature while a weak negative relation was found between methane fluxes and soil humidity. No soil methane absorption has been observed. European Commission. Fifth National Communication from the European Community Under the UN Framework Convention on Climate Change (UNFCCC). Technical Report - 2009 – 038 (2009). [less ▲]

Detailed reference viewed: 174 (24 ULg)
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See detailCattle neosporosis in Belgium : a case-control study in dairy and beef cattle
De Meerscham, F.; Focant, C.; Boreux, R. et al

in International Journal for Parasitology (2000)

Detailed reference viewed: 83 (11 ULg)
See detailCattle production from grass in intensive areas. Ecological Aspects of Grassland Management
Dufrasne, Isabelle ULg; Istasse, Louis ULg; Raskin, Pascale et al

in Grassland Science in Europe (1998)

Detailed reference viewed: 13 (1 ULg)
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See detailCattle pulmonary smooth muscles contractile response to serotonin after atropine pretreatment
Linden, Annick ULg; Desmecht, Daniel ULg; Amory, Hélène ULg et al

in Archives Internationales de Physiologie et de Biochimie (1993)

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See detailCAU-1, a subclass B3 metallo-beta-lactamase of low substrate affinity encoded by an ortholog present in the Caulobacter crescentus chromosome
Docquier, J. D.; Pantanella, F.; Giuliani, F. et al

in Antimicrobial Agents and Chemotherapy (2002), 46(6), 1823-1830

The sequenced chromosome of Caulobacter crescentus CB15 encodes a hypothetical protein that exhibits significant similarity (30 to 35% identical residues) to metallo-beta-lactamases of subclass B3. An ... [more ▼]

The sequenced chromosome of Caulobacter crescentus CB15 encodes a hypothetical protein that exhibits significant similarity (30 to 35% identical residues) to metallo-beta-lactamases of subclass B3. An allelic variant of this gene (divergent by 3% of its nucleotides) was cloned in Escherichia coli from C crescentus type strain DSM4727. Expression studies confirmed the metallo-p-lactamase activity of its product, CAU-1. The enzyme produced in E. coli was purified by two ion-exchange chromatography steps. CAU-1 contains a 29-kDa polypeptide with an alkaline isoelectric pH (>9), and unlike the L1 enzyme of Stenotrophomonas maltophilia, the native form is monomeric. Kinetic analysis revealed a preferential activity toward penicillins, carbapenems, and narrow-spectrum cephalosporins, while oxyimino cephalosporins were poorly or not hydrolyzed. Affinities for the various beta-lactams were poor overall (K-m values were always >100 muM and often >400 muM). The interaction with divalent ion chelators appeared to occur by a mechanism similar to that prevailing in other members of subclass B3. In C. crescentus, the CAU-1 enzyme is produced independently of beta-lactam exposure and, interestingly, the bla(CAU) determinant is bracketed by three other genes, including two genes encoding enzymes involved in methionine biosynthesis and a gene encoding a putative transcriptional regulator, in an operon-like structure. The CAU-1 enzyme is the first example of a metallo-beta-lactamase in a member of the alpha subdivision of the class Proteobacteria. [less ▲]

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See detailCaudectomie consécutive à une fracture vertébrale chez un taureau
Lamain, Guillaume ULg; Sartelet, Arnaud ULg

in Point Vétérinaire (2011), 312

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See detailCaudectomie haute pour traiter une fracture vertébrale avec ostéolyse
Lamain, Guillaume ULg; Sartelet, Arnaud ULg; Touati, Kamal ULg

in Point Vétérinaire (2011), 312

Detailed reference viewed: 64 (10 ULg)
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See detailCaught on the Boundary: The Micro-Processes of Social Movement-Corporate Relationships
Huybrechts, Benjamin ULg; Nicholls, Alex

Conference (2010, September 13)

Detailed reference viewed: 66 (6 ULg)
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See detailCausal filter selection in microarray data
Bontempi, Gianluca; Meyer, Patrick ULg

in Proceedings of the 27th International Conference on Machine Learning (ICML-10) (2010)

Detailed reference viewed: 33 (2 ULg)
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See detailCausale connectieven in het Leerdercorpus Nederlands
Degand, Liesbeth; Perrez, Julien ULg

in N/F. Tijdschrift van de Association des néerlandistes de Belgique francophone (2004), 4

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See detailCausative role of VZV in two fatal disseminated infections
Nikkels, Arjen ULg; Debrus, S.; Sadzot-Delvaux, Catherine ULg et al

Conference (1994)

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See detailLa cause - Le rôle respectif du juge et des parties dans l'allégation des faits et la détermination de la règle de droit applicable au litige
Boularbah, Hakim ULg

in J. Linsmeau et M. Storme : Le rôle respectif du juge et des parties dans le procès civil (1999)

Detailed reference viewed: 123 (3 ULg)
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See detailUne cause atypique de fistule cutanée
Damiens, Justine; Shimizu, Naomi ULg; Claeys, Stéphanie ULg et al

in Monde Vétérinaire (Le) (2016), 163

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See detailLa cause d'utilité publique
Pâques, Michel ULg; Donnay, Luc ULg; Vercheval, Cécile ULg

in Renders, David (Ed.) L'expropriation pour cause d'utilité publique (2013)

Detailed reference viewed: 55 (11 ULg)