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See detailA comparison of supraglacial lake observations derived from MODIS imagery at the western margin of the Greenland ice sheet
Leeson, A.; Shepherd, A.; Sundal, A. et al

in Journal of Glaciology (2013), 59(208), 1179-1188

Supraglacial lakes (SGLs) affect the dynamics of the Greenland ice sheet by storing runoff and draining episodically. We investigate the evolution of SGLs as reported in three datasets, each based on ... [more ▼]

Supraglacial lakes (SGLs) affect the dynamics of the Greenland ice sheet by storing runoff and draining episodically. We investigate the evolution of SGLs as reported in three datasets, each based on automated classification of satellite imagery. Although the datasets span the period 2001–10, there are differences in temporal sampling, and only the years 2005–07 are common. By subsampling the most populous dataset, we recommend a sampling frequency of one image per 6.5 days in order to minimize uncertainty associated with poor temporal sampling. When compared with manual classification of satellite imagery, all three datasets are found to omit a sizeable (29, 48 and 41%) fraction of lakes and are estimated to document the average size of SGLs to within 0.78, 0.48 and 0.95 km2 . We combine the datasets using a hierarchical scheme, producing a single, optimized, dataset. This combined record reports up to 67% more lakes than a single dataset. During 2005–07, the rate of SGL growth tends to follow the rate at which runoff increases in each year. In 2007, lakes drain earlier than in 2005 and 2006 and remain absent despite continued runoff. This suggests that lakes continue to act as open surface–bed conduits following drainage. [less ▲]

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See detailComparison of T1 and T2 - weighted and Blade MRI sequences for examination of canine normal abdomen
Hoffmann; Buttin; Haye et al

Poster (2008)

Detailed reference viewed: 51 (1 ULg)
See detailA Comparison of TEC Values Derived by Using GPS, Ionosonde and NNSS Data
Warnant, René ULg; Jodogne, Jean-Claude; Van Camp, Michel

in Kersley, Len (Ed.) Proceedings of Beacon Satellite Symposium '94 (1994)

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See detailComparison of temperature estimates from heat transport model and electrical resistivity tomography during a shallow heat injection and storage experiment
Hermans, Thomas ULg; Daoudi, Moubarak ULg; Vandenbohede, Alexander et al

in Berichte der Geologischen Bundesanstalt (2012, September), 93

Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is ... [more ▼]

Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is therefore important. Geophysical methods may be useful in order to yield additional information with greater coverage than conventional wells. We report a heat transport study during a shallow heat injection and storage field test. Heated water (about 50°C) was injected for 6 days at the rate of 80 l/h in a 10.5°C aquifer. Since bulk electric resistivity variations can bring important information on temperature changes in aquifers (water electric conductivity increases about 2%/°C around 25°C), we monitored the test with surface electric resistivity tomography and demonstrate its ability to monitor spatially temperature variations. Time-lapse electric images clearly show the decrease and then the increase in bulk electric resistivity of the plume of heated water, during respectively the injection and the storage phase. This information enabled to calibrate the conceptual flow and heat model used to simulate the test. Inverted resistivity values are validated with borehole electromagnetic measurements (EM39) and are in agreement with the temperature logs used to calibrate the parameters of the thermo-hydrogeological model for the injection phase. This field work demonstrates that surface electric resistivity tomography can monitor heat and storage experiments in shallow aquifers. These results could potentially lead to a number of practical applications, such as the monitoring or the design of shallow geothermal systems or the use of heated water to replace salt water in tracer tests. [less ▲]

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See detailComparison of the ability of three radioimmunoassay to detect pregnancy-associated glycoproteins in bovine plasma
Perenyi, Z. S.; Szenci, Otto; Sulon, Joseph ULg et al

in Reproduction in Domestic Animals (2002), 37(2), 100-104

Pregnancy-associated glycoproteins (PAGs) constitute a large family of glycoproteins that are synthesized in the superficial layer of the ruminant placenta according to a spatial and temporal expression ... [more ▼]

Pregnancy-associated glycoproteins (PAGs) constitute a large family of glycoproteins that are synthesized in the superficial layer of the ruminant placenta according to a spatial and temporal expression pattern. When PAGs are released in the maternal blood they can be used for pregnancy diagnosis, pregnancy follow-up and for the monitoring of the trophoblastic function. Three different radioimmunoassay systems (RIA 1, RIA 2 and RIA 3) using antisera produced against PAG I67 (RIA 1), PAG55+62 (RIA 2) and PAG55+59 (RIA 3) were used in this investigation in order to measure the PAG concentration in plasma samples withdrawn from pregnant cows and heifers during different periods following artificial insemination (AI). These systems were able to detect PAG molecules in the maternal blood as early as 21 days after AI in different concentrations (RIA 1: 0.43 +/- 0.24 ng/ml, mean +/- SD; RIA 2: 0.48 +/- 0.24 ng/ml; RIA 3: 0.64 +/- 0.37 ng/ml). On days 32 and 42 RIA 2 (4.30 +/- 1.32 ng/ml and 5.56 +/- 1.95 ng/ml) and RIA 3 (4.17 +/- 1.15 ng/ml and 5.60 +/- 1.89 ng/ml) presented significantly (p < 0.0001) higher PAG concentrations than those of RIA 1 (2.43 +/- 0.81 ng/ml and 4.01 +/- 1.48 ng/ml), respectively. After day 21, significant correlations (p < 0.0001; r >/= 0.929) were determined between the three systems. Additionally the three individual PAG profiles presented in this study showed that PAG molecules secreted in the maternal blood between 21 and 50 days after AI were better recognized by the RIA 2 and RIA 3 systems. This study clearly indicated that the ability of a RIA test to recognize PAG molecules in the maternal blood can be improved by carefully selecting the antiserum. [less ▲]

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See detailA Comparison of the Acidity Levels in Room-Temperature Ionic Liquids
Robert, Thierry ULg; Magna, Lionel; Olivier-Bourbigou, Hélène et al

in Journal of the Electrochemical Society (2009), 156(9), 115

The Broensted acidity level was evaluated for several ionic liqs. ([BMIm][BF4], [BMIm][PF6], [BMIm][SbF6], [BMIm][OTf], [BMIm][NTf2], [HNET3][NTf2], and [HBIm][NTf2]) to which a strong acid, such as HNTf2 ... [more ▼]

The Broensted acidity level was evaluated for several ionic liqs. ([BMIm][BF4], [BMIm][PF6], [BMIm][SbF6], [BMIm][OTf], [BMIm][NTf2], [HNET3][NTf2], and [HBIm][NTf2]) to which a strong acid, such as HNTf2 [NTf2=N(CF3SO2)2] and HOTf (OTf=CF3SO3), has been added. The main purpose is to tentatively measure the influence on the resulting acidity of (i) the solvent anion or cation structure and (ii) the added acid nature. The evaluation method is based on the detn. of the Hammett acidity functions H0 using UV/visible spectroscopy. The acidity of protons is mainly detd. by their solvation state, and consequently, the properties of protons depend on both the nature of the solvent and the nature and concn. of the acid. In practice, for the investigated ionic liqs., the cation as well as the added acid nature does not play a dominant role, whereas changing the anion nature may lead to very different acidities. Indeed, for a similar content of added acid, the measured acidity levels are in the order PF6- > BF4- > NTf2- > OTf-. The problems of the influence of impurities on the final acidity and of the dissocg. character of the ionic liq. are addressed. [less ▲]

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See detailComparison of the adrenocortical response to both pharmacological and physiological stresses in sport horses
Linden, Annick ULg; Art, Tatiana ULg; Amory, Hélène ULg et al

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (1990), 37(8), 601-604

Seven sport horses were investigated to compare physiological and pharmacological stresses on the plasma glucocorticosteroid levels. <br />Venous blond was sampled and analysed for cortisol concentrations ... [more ▼]

Seven sport horses were investigated to compare physiological and pharmacological stresses on the plasma glucocorticosteroid levels. <br />Venous blond was sampled and analysed for cortisol concentrations before and after each type of stress. The physiological stress was induced by the completion of a cross-country and the phar¬macological one, by an intravenous ACTH administration (200 µg) in the came horses, one week after the course. <br />Both exercise and ACTH injection induced a highly significant cortisol increase of 79 ± 0.10 %, and 160 ± 0.18 %, respectively. The relative plasma cortisol increases due to exercise on the nue hand, and due to ACTH administration on the other hand, were correlated with a coefficient of 0.82. It was concluded that the plasma cortisol increase induced by a standardised pharmacological stress could be used in order to predict the exercise-induced stress response. [less ▲]

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See detailComparison of the amnesic, ataxic and hypothermic effects of ethanol and acetaldehyde in mice
Closon, Catherine ULg; Quertemont, Etienne ULg

in Alcoholism, Clinical & Experimental Research (2010), 34(8), 92-92

Acetaldehyde, the first metabolite of ethanol, has been suggested to be involved in many behavioral effects of ethanol. However, very few studies have been published on the role of acetaldehyde in the ... [more ▼]

Acetaldehyde, the first metabolite of ethanol, has been suggested to be involved in many behavioral effects of ethanol. However, very few studies have been published on the role of acetaldehyde in the amnesic and ataxic effects of ethanol. The aim of the present studies was to compare the profiles of ethanol and acetaldehyde in several behavioral tests, measuring motor coordination, learning and memory in mice. Female Swiss mice were injected intraperitoneally with ethanol (0-3g/kg) and acetaldehyde (100-300mg/kg). The effects of these substances on a series of representative behaviors were investigated. The amnesic effects were tested with an object recognition task and a one-trial passive avoidance test. Additionally, the rectal temperatures were used to evaluate the hypothermic effects of the two substances. Finally, motor coordination was assessed using the accelerating rotarod test. The results showed that acetaldehyde, like ethanol, altered memory as shown by a reduced performance in the passive avoidance test and the object recognition task. In addition, acetaldehyde at doses between 100 and 300 mg/kg induced significant hypothermic effects, but that was of shorter duration than ethanol-induced hypothermia. Finally, significant ataxic effects of both acetaldehyde and ethanol were observed in the accelerating rotarod test. Overall, the results of the present study clearly show that acetaldehyde, like ethanol, has amnesic, hypothermic and ataxic properties in mice at least at relatively high concentrations. [less ▲]

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See detailComparison of the antihypertensive efficacy and tolerability of candesartan cilexetil and angiotensin-converting enzyme inhibitor therapy in primary hypertension: the champion study
Lins, R.; Krzesinski, Jean-Marie ULg; Vandenhoven, G. et al

in American Journal of Hypertension : Journal of the American Society of Hypertension (2001), 4

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See detailComparison of the candesartan cilexetil and angiotensin-converting enzyme inhibitor therapy in mild to moderate hypertension
Krzesinski, Jean-Marie ULg; Lins, R.; Vandenhoven, G. et al

in Journal of hypertension (2001)

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See detailComparison of the cardiac pumping capability and cardiac pumping reserve in double muscled and conventional calves
Amory, Hélène ULg; Mc Entee, Kathleen ULg; Linden, Annick ULg et al

in Canadian Journal of Physiology & Pharmacology (1993), 71(12), 946-951

Hereditary muscular hypertrophy is a character that has been selected in several animal species for industrial meat production. The selection of this character in cattle produces animals of exceptional ... [more ▼]

Hereditary muscular hypertrophy is a character that has been selected in several animal species for industrial meat production. The selection of this character in cattle produces animals of exceptional commercial value but ones with a lower aerobic capacity than that of conventional cattle. The purpose of this work was to study the role of cardiac function as a potential limiting factor of aerobic capacity in double-muscled calves. Two groups of healthy calves were studied, one consisting of nine calves of conventional conformation and the other of nine double-muscled calves. Pulmonary arterial and capillary wedge, central venous, and systemic arterial pressures were measured by fluid-filled catheters and recorded together with the electrocardiogram. Cardiac output was measured by the thermodilution technique. From these measurements, the heart rate, the cardiac and the stroke indices, the pulmonary and the systemic vascular resistances, and the cardiac power output were calculated. The parameters were recorded under basal resting conditions and during incremental dobutamine challenge, which allowed determination of the resting cardiac power output, the cardiac pumping capability, and the cardiac reserve. Dobutamine challenge induced a significant rise in cardiac and stroke indices, heart rate, and cardiac power output, a significant decrease in pulmonary and systemic vascular resistances, and no change in systemic and pulmonary arterial pressures. The cardiac reserve obtained in the present study was low in comparison with those previously reported in humans, dogs, and horses. This may be related to the poor running capability of bovine species relative to that of the former species.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

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See detailComparison of the collision-induced dissociation of duplex DNA at different collision regimes: Evidence for a multistep dissociation mechanism
Gabelica, Valérie ULg; De Pauw, Edwin ULg

in Journal of the American Society for Mass Spectrometry (2002), 13(1), 91-98

The dissociation mechanism of duplex DNA has been investigated in detail by collision-induced dissociation experiments at different collision regimes. MS/MS experiments were performed either in a ... [more ▼]

The dissociation mechanism of duplex DNA has been investigated in detail by collision-induced dissociation experiments at different collision regimes. MS/MS experiments were performed either in a quadrupole collision cell (hybrid quadrupole-TOF instrument) or in a quadrupole ion trap with different activation times and energies. In addition to the noncovalent dissociation of the duplex into the single strands, other covalent bond fragmentation channels were observed. Neutral base loss from the duplex is favored by slow activation. In fast activation conditions, however, the major reaction channel is the noncovalent dissociation into single strands, which is highly entropy-favored. Fast activation regimes can favor the entropy-driven noncovalent dissociation, while in slow heating conditions the competition with enthalpy-driven covalent fragmentation can completely hinder the dissociation of the complex. We also evidence that the noncovalent dissociation of DNA duplex is a multistep process involving a progressive unzipping, preferentially at terminal positions. This is proposed to be a general feature for complexes containing a high number of contributing interactions organized at the interface of the ligands. The overall (observed) dissociation kinetics of noncovalent complexes can therefore depend on a complicated mechanism for which a single transition state description of the kinetics is too simplistic. [less ▲]

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See detailComparison of the current techniques used for the denoising of scintigraphic images
Kirkove, Murielle ULg; Seret, Alain ULg

in European Journal of Nuclear Medicine and Molecular Imaging (2006), 33(S2), 318

Detailed reference viewed: 26 (9 ULg)