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See detailCation Distribution Dependent Magnetic Properties in CoCr 2-x Fe x O 4 (x= 0.1 to 0.5): EXAFS, Mӧssbauer and Magnetic Measurements
Kumar, Durgesh; Banerjee, Alok; Mahmoud, Abdelfattah ULiege et al

in Dalton Transactions (2017), 46

In this report, we have examined the evolution of the structure and rich magnetic transitions such as a paramagnetic to ferrimagnetic phase transition at the Curie temperature (TC), spiral ordering ... [more ▼]

In this report, we have examined the evolution of the structure and rich magnetic transitions such as a paramagnetic to ferrimagnetic phase transition at the Curie temperature (TC), spiral ordering temperature (TS) and lock-in temperature (TL) observed in the CoCr2O4 spinel multiferroic after substituting Fe. The crystal structure, microstructure and cation distribution among the tetrahedral (A) and octahedral (B) sites in the spinel lattice are characterised by X-ray diffraction, transmission electron microscopy, Extended X-ray Absorption Fine Structure (EXAFS) and Mössbauer spectroscopy. Due to the same radial distances of the first coordination shell in both tetrahedral and octahedral environments observed in EXAFS spectra, the position of the second coordination shell specifies the preference of more Fe ions towards the A site at x = 0.1. At x = 0.5, more Fe ions favour the B site. The cation distribution quantitatively obtained from the Mössbauer spectral analysis shows that while 60% of Fe ions occupy the A site in x = 0.1, 40% occupy it in x = 0.5. Surprisingly at x = 0.3, Fe ions are distributed equally among the A and B sites. dc magnetization reveals an increase in TC from 102 K to 200 K and in TS from 26 to 40 K with an increase in Fe concentration, indicating an enhancement in A–B exchange interaction at the expense of B–B. No report has until now demonstrated such an enhancement in TS either in pure or in doped CoCr2O4. Furthermore, frequency-dependent ac susceptibility (χ) data fitted with different phenomenological models such as the Néel–Arrhenius, Vogel–Fulcher and power law confirm a spin-glass and/or cluster-glass behaviour in nanoparticles of CoCr2−xFexO4. [less ▲]

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See detailCation Involvement in Telomestatin Binding to G-Quadruplex DNA
Rosu, Frédéric ULiege; Gabelica, Valérie ULiege; Smargiasso, Nicolas ULiege et al

in Journal of Nucleic Acids (2010)

The binding mode of telomestatin to G-quadruplex DNA has been investigated using electrospray mass spectrometry, by detecting the intact complexes formed in ammonium acetate. The mass measurements show ... [more ▼]

The binding mode of telomestatin to G-quadruplex DNA has been investigated using electrospray mass spectrometry, by detecting the intact complexes formed in ammonium acetate. The mass measurements show the incorporation of one extra ammonium ion in the telomestatin complexes. Experiments on telomestatin alone also show that the telomestatin alone is able to coordinate cations in a similar way as a crown ether. Finally, density functional theory calculations suggest that in the G-quadruplex-telomestatin complex, potassium or ammonium cations are located between the telomestatin and a G-quartet. This study underlines that monovalent cation coordination capabilities should be integrated in the rational design of G-quadruplex binding ligands. [less ▲]

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See detailCation partitioning between minerals of the triphylite ± graftonite ± sarcopside association in granitic pegmatites
Roda-Robles, Encarnacion ULiege; Galliski, Migule; Nizamoff, Jim et al

Conference (2011)

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See detailCation-doped Cu2O as a transparent p-type semiconducting oxide with enhanced performances: A comparison between strontium and magnesium incorporation
Avelas Resende, João ULiege; Brochen, Stéphane; Bergerot, Laurent et al

Conference (2016, October)

In the group of semiconducting metallic oxides, cuprous oxide (Cu2O) presents promising electrical and manufacturing features for a variety of applications as p-type transparent material suitable in the ... [more ▼]

In the group of semiconducting metallic oxides, cuprous oxide (Cu2O) presents promising electrical and manufacturing features for a variety of applications as p-type transparent material suitable in the domains of transparent electronics and photovoltaic cells. However Cu2O suffers from optical and electrical limitations, due to a relatively small bandgap of 2.17 eV and a fairly high resistivity (> 102 Ω.cm) in intrinsic thin films at room temperature. In this work, we successfully doped Cu2O thin films with different divalent cations, namely Sr and Mg, by metal-organic chemical vapour deposition. We compared the effects of each element on crystallographic structure, films morphology, electronic transport and optical transmittance. In both cases, the presence of the cation contributed to a higher stability of the Cu2O phase, reducing the appearance of CuO parasitic phase. Nevertheless, a SrCO3 phase was detected in the Sr doped system. In terms of electrical properties, the incorporation of Sr, up to 16%, reduced the resistivity down to 1Ω.cm, with a mobility of 16 cm2.V-1.s-1. Moreover, the incorporation of strontium also leads to the emergence of a with a deep acceptor level located around EA = 278 ± 21 meV above the top of the valence band. The concentration of this deep acceptor level, attributed to simple copper vacancies, drastically increases with the strontium content, due to a decrease of its formation energy. The effect on optical transmittance could not be detected. The Mg-doped Cu2O thin films were monophasic and showed a higher resistivity of 6.6 Ω.cm at an Mg concentration of 17%, due to the lower mobility, 1 cm2.V-1.s-1. Although, the presence of this dopant contributes for the highest charge-carrier density observed in this work, up to 8x1017 cm-3. As in the Sr case, this can be explained by a simple copper vacancy doping mechanism assisted by cation incorporation. Additionally, a slight increase of transparency is observed when compared to intrinsic Cu2O. The control of carrier concentration and mobility values by dopant concentration, as well as the improvements in phase stability and transparency are key factors for the application of this versatile p-type oxide in transparent electronics and solar cells applications. [less ▲]

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See detailCationic and secretory effects of BPDZ 44 and diazoxide in rat pancreatic islets
Antoine, M.-H.; Pirotte, Bernard ULiege; Hermann, M. et al

in Experientia (1994), 50

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See detailCationic pattern of hemolymph in adult hymenoptera
Florkin, Marcel ULiege; Jeuniaux, Charles ULiege

in Life Sciences (1963), 12

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See detailLes cations inorganiques dans l'hémolymphe larvaire des insectes trichoptères
Beaujot, J.; Naoumoff, M.; Jeuniaux, Charles ULiege

in Archives Internationales de Physiologie et de Biochimie (1970), 78

The inorganic cationic composition of the larval haemolymph has been studied in 6 species of Trichoptera. The amounts of K and Ca are constant and very low. The variations of the Na concentrations are ... [more ▼]

The inorganic cationic composition of the larval haemolymph has been studied in 6 species of Trichoptera. The amounts of K and Ca are constant and very low. The variations of the Na concentrations are generally comprised between 60 and 99 mEq/l. On the contrary, the concentrations of Mg are highly variable in the different species : the extreme values observed so far are respectively 10.5 and 205 mEq/l. However, contrary to what is well known in the case of Lepidoptera, the high concentrations of Mg are not accompanied by low Na concentrations. As far as cationic patterns of larval haemolymph are concerned, Trichoptera appear to occupy an intermediate position between Mecoptera and Lepidoptera. [less ▲]

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See detailCaton l'Ancien : étude biographique
Kurth, Godefroid ULiege

Doctoral thesis (1872)

Detailed reference viewed: 101 (5 ULiège)
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See detailcatR: an R package for computerized adaptive testing
Magis, David ULiege; 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 ▲]

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See detailCattedrale e collegiali di Liegi
Corswarem, Emilie ULiege

Conference (2006, December 07)

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See detailCattle enterotoxaemia and Clostridium perfringens: description, diagnosis and prophylaxis
Lebrun, M.; Mainil, Jacques ULiege; Linden, Annick ULiege

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 ULiege

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 ULiege; Aubinet, Marc ULiege; Beckers, Yves ULiege 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 ▲]

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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: 86 (11 ULiège)
See detailCattle production from grass in intensive areas. Ecological Aspects of Grassland Management
Dufrasne, Isabelle ULiege; Istasse, Louis ULiege; Raskin, Pascale et al

in Grassland Science in Europe (1998)

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

in Point Vétérinaire (2011), 312

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

in Point Vétérinaire (2011), 312

Detailed reference viewed: 66 (10 ULiège)