Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailQuantitative interpretation of atmospheric carbon records over the last glacial termination
Köhler, Peter; Fischer, Hubertus; Munhoven, Guy ULg et al

in Global Biogeochemical Cycles (2005), 19(4), 4020

The glacial/interglacial rise in atmospheric pCO(2) is one of the best known changes in paleoclimate research, yet the cause for it is still unknown. Forcing the coupled ocean-atmosphere-biosphere box ... [more ▼]

The glacial/interglacial rise in atmospheric pCO(2) is one of the best known changes in paleoclimate research, yet the cause for it is still unknown. Forcing the coupled ocean-atmosphere-biosphere box model of the global carbon cycle BICYCLE with proxy data over the last glacial termination, we are able to quantitatively reproduce transient variations in pCO(2) and its isotopic signatures (delta C-13, Delta C-14) observed in natural climate archives. The sensitivity of the Box model of the Isotopic Carbon cYCLE ( BICYCLE) to high or low latitudinal changes is comparable to other multibox models or more complex ocean carbon cycle models, respectively. The processes considered here ranked by their contribution to the glacial/interglacial rise in pCO(2) in decreasing order are: the rise in Southern Ocean vertical mixing rates (> 30 ppmv), decreases in alkalinity and carbon inventories (> 30 ppmv), the reduction of the biological pump (similar to 20 ppmv), the rise in ocean temperatures (15 - 20 ppmv), the resumption of ocean circulation (15 - 20 ppmv), and coral reef growth (< 5 ppmv). The regrowth of the terrestrial biosphere, sea level rise and the increase in gas exchange through reduced sea ice cover operate in the opposite direction, decreasing pCO(2) during Termination I by similar to 30 ppmv. According to our model the sequence of events during Termination I might have been the following: a reduction of aeolian iron fertilization in the Southern Ocean together with a breakdown in Southern Ocean stratification, the latter caused by rapid sea ice retreat, trigger the onset of the pCO(2) increase. After these events the reduced North Atlantic Deep Water (NADW) formation during the Heinrich 1 event and the subsequent resumption of ocean circulation at the beginning of the Bolling-Allerod warm interval are the main processes determining the atmospheric carbon records in the subsequent time period of Termination I. We further deduce that a complete shutdown of the NADW formation during the Younger Dryas was very unlikely. Changes in ocean temperature and the terrestrial carbon storage are the dominant processes explaining atmospheric d13C after the Bolling-Allerod warm interval. [less ▲]

Detailed reference viewed: 7 (1 ULg)
Peer Reviewed
See detailQuantitative M-Mode and Two-Dimensional Echocardiography in Calves
Amory, Hélène ULg; Jakovljevic, S.; Lekeux, Pierre ULg

in Veterinary Record : Journal of the British Veterinary Association (1991), 128(2), 25-31

A standardised echocardiographic protocol was applied to 18 healthy calves for the estimation of 51 anatomical and functional cardiac variables. These variables were measured in a long axis and a short ... [more ▼]

A standardised echocardiographic protocol was applied to 18 healthy calves for the estimation of 51 anatomical and functional cardiac variables. These variables were measured in a long axis and a short axis view of the heart, and both two-dimensional and cursor-directed time-motion (M-) modes were used. The repeatability of each of the measurements was estimated by comparing values obtained twice within 24 hours, and most of the 51 variables showed a high degree of repeatability. Statistical analysis revealed a close correlation between cardiac measurements taken post mortem and by in vivo echocardiography, and between the echocardiographic values obtained in different scanning planes of the heart or ultrasonic modes, indicating that quantitative echocardiography is a reliable technique in calves. [less ▲]

Detailed reference viewed: 16 (3 ULg)
Full Text
Peer Reviewed
See detailQuantitative measurement of metal ions concentration of proteins separated by electrophoresis
Weber, Georges ULg; Strivay, David ULg; Menendez, M. et al

in International Journal of PIXE (1996), 1-2

This communication is devoted to nature determination and quantification by PIXE of metals contained in proteins after their separation by PolyAcrylamide Gel Electrophoresis (PAGE). After the ... [more ▼]

This communication is devoted to nature determination and quantification by PIXE of metals contained in proteins after their separation by PolyAcrylamide Gel Electrophoresis (PAGE). After the electrophoresis, the gel is dried and each track is scanned with a 2.5 MeV proton beam which triggers metal X-ray fluorescence and then, allows to determine the type of metals contained in an electrophoretic band. For quantitative determination of the amount of the metal contained inside the band, the characteristic X-ray peak area is compared with those obtained with polyacrylamide gels doped with the same metal. The normalization has been achieved by using RBS measurements on the gel itself. The procedure presented seems to be a very useful multielementary method for the metal content analysis and for the determination of the metal amounts inside proteins after their separation by electrophoresis. Furthermore it allows to check if metals remain bound to proteins. [less ▲]

Detailed reference viewed: 28 (1 ULg)
Full Text
Peer Reviewed
See detailQuantitative methods for food allergens: a review.
Kirsch, Stéphanie ULg; Fourdrilis, Séverine ULg; Dobson, Rowan ULg et al

in Analytical and Bioanalytical Chemistry (2009), 395

The quantitative detection of allergens in the food chain is a strategic health objective as the prevalence of allergy continues to rise. Food allergenicity is caused by proteins either in their native ... [more ▼]

The quantitative detection of allergens in the food chain is a strategic health objective as the prevalence of allergy continues to rise. Food allergenicity is caused by proteins either in their native form or in forms resulting from food processing. Progress in mass spectrometry greatly opened up the field of proteomics. These advances are now available for the detection and the quantification of traces of allergenic proteins in complex mixtures, and complete the set of biological tests used until now, such as ELISA or PCR. We review methods classified according to their ability to simultaneously quantify and identify allergenic proteins and underline major advances in the mass-spectrometric methods. [less ▲]

Detailed reference viewed: 274 (50 ULg)
Full Text
See detailQuantitative Micro-Imaging of Building Materials : from reality to dream
Pirard, Eric ULg; CSTC

in La microscopie appliquée aux matériaux de construction (2002)

Detailed reference viewed: 11 (1 ULg)
Full Text
Peer Reviewed
See detailQuantitative Microtexture Analysis of Carbonate Rocks Using Bireflectance Imaging
Jaimes Contreras, Rafael Antonio ULg; Pilawski, Dimitri; Califice, Arnaud ULg et al

in Proceedings IAMG 2010 (2010)

Microtextural analysis of rocks has been addressed by several authors as an essential means to better understand the natural genesis of the material. But, it is also of paramount importance to those who ... [more ▼]

Microtextural analysis of rocks has been addressed by several authors as an essential means to better understand the natural genesis of the material. But, it is also of paramount importance to those who try to predict the geotechnical or industrial behaviour of a rock under many forms of solicitation (mechanical, thermal, etc.). Quantitative modal (phase) analysis using point counting has already been discussed in depth by authors such as Chayes more than fifty years ago. Nowadays, automated image analysis with millions of pixels is easily available and improves statistical accuracy provided the classification step is correctly performed. Spitefully the assignment of a pixel to a given mineral phase or to a given crystal is often poorly satisfactory and remains the bottleneck of a fully automated textural analysis. Methods using a manual rotation of a polarizer in transmitted light microscopy have been developed by Starkey and Samantaray (1993) and further automated and improved by Fueten (1997). These allow to better delineate individual crystals in a thin section due to contrast in birefringence. In this paper a similar technique using multiple orientations of a polarizer in reflected light microscopy has been used to contrast individual crystals in carbonated rocks. The maximum and minimum grey levels registered for each pixel allow for computing a bireflectance image whose variance is a good indicator of the misalignment of cristallographical orientations in the section. Moreover, the maximum of the reflectance gradient obtained for each orientation generates a good image of the grain boundaries and the presence of pores. This last one is quantitatively analysed using the intercept method to estimate the mean and variance of the grain size distribution. The paper presents a quantitative comparison of several different microtextures. [less ▲]

Detailed reference viewed: 117 (7 ULg)
Full Text
Peer Reviewed
See detailQuantitative mineralogical analysis of Cobalt and Copper distribution in historical slags from Küre (Turkey)
Pirard, Eric ULg

in Canadian Mining and Metallurgical Bulletin (The) (1991), 84(946), 87-91

Detailed reference viewed: 18 (8 ULg)
Full Text
Peer Reviewed
See detailQuantitative modeling of Sr, Ca, Rb, K in the Bjerkreim-Sokndal lopolith (S.W. Norway)
Duchesne, Jean-Clair ULg

in Contributions to Mineralogy & Petrology (1978), 66

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailQuantitative morphological studies of mesoporous catalysts at nanometer scale resolution
Ziese, Ulrike; Gommes, Cédric ULg; Blacher, Silvia ULg et al

in Studies in Surface Science and Catalysis (2005), 158

We have combined electron tomography with posterior image processing for a quantitative morphological study of mesoporous catalysts at nanometer scale resolution. As a first example for the possibilities ... [more ▼]

We have combined electron tomography with posterior image processing for a quantitative morphological study of mesoporous catalysts at nanometer scale resolution. As a first example for the possibilities of the approach, pore size distributions of single particles of commercial USY and XVUSY zeolites were derived. [less ▲]

Detailed reference viewed: 17 (1 ULg)
Full Text
Peer Reviewed
See detailQuantitative nephelometric assay for determining myoglobin evaluated
Delanghe, J. R.; Chapelle, Jean-Paul ULg; Vanderschueren, S. C.

in Clinical Chemistry (1990), 36(9), 1675-8

A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of myoglobin (Behringwerke) was evaluated with the BNA Nephelometer. Method precision was good ... [more ▼]

A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of myoglobin (Behringwerke) was evaluated with the BNA Nephelometer. Method precision was good: the intra-assay CV varied between 1.5% and 6.1%; with daily calibration, the interassay CV ranged between 1.5% and 7.5%. For usual sample dilutions, the assay response varied linearly with myoglobin concentrations up to 23.1 nmol/L. After automatic dilution by the instrument, concentrations up to 2310 nmol/L could be measured without high-dose "hook" effect. Further manual dilution allowed measurement of myoglobin concentrations up to 26,000 nmol/L. Calibration was stable for at least seven days. We detected no significant interferences from hemoglobin, haptoglobin, bilirubin, iodine-containing contrast media, and rheumatoid factors. Treating lipemic samples with Lipoclean (Behringwerke) decreased test results. Simultaneously drawn serum and plasma samples from the same subject showed no consistent differences in myoglobin concentrations. The mean reference myoglobin concentration was 1.380 (SD 0.82) nmol/L for men and 0.878 (SD 0.45) nmol/L for women. In patients with renal insufficiency, serum creatinine values were moderately related to serum myoglobin values (r = 0.465). Although a commercial radioimmunoassay (Byk-Sangtec) and the nephelometric assay intercorrelated well (r = 0.929), values obtained by nephelometry were significantly lower (P less than 0.05). By both assays, results for heart and skeletal muscle tissue extracts showed no correlation, a finding that suggests the existence of multiple forms of myoglobin in human tissues. We conclude that immunonephelometry is a rapid, practical, and reliable method for measuring myoglobin in serum. [less ▲]

Detailed reference viewed: 5 (1 ULg)
See detailQuantitative NIR Spectroscopy of Massive Stars
Sana, H.; Stap, F. A.; de Koter, A. et al

in Astronomical Society of the Pacific Conference Series (2013, January 01)

Interest for near-infrared (NIR) spectroscopy of massive stars has been dramatically increasing over the last decade. Because it allows one to observe objects inaccessible at optical wavelengths due to ... [more ▼]

Interest for near-infrared (NIR) spectroscopy of massive stars has been dramatically increasing over the last decade. Because it allows one to observe objects inaccessible at optical wavelengths due to absorption, the infrared domain offers a privileged window to study highly extinguished objects. Yet, a detailed calibration of the massive star properties at NIR wavelength is still missing. Following the lines of the work of Repolust et al. (2005), we have acquired high resolution spectroscopy of several nearby massive stars using VLT/CRIRES, focusing on spectral lines of interest in the J, H, K, and L bands. In this work, we present the earliest results of our quantitative spectroscopic analysis of the main sequence stars in our sample. Using the unique combination of a genetic algorithm approach with the state-of-the-art non-LTE atmosphere model FASTWIND, we compare the stellar and wind properties as derived from the optical and the NIR regime. [less ▲]

Detailed reference viewed: 13 (4 ULg)
Full Text
Peer Reviewed
See detailQuantitative onvergence analysis of multi-agent systems
tuna, S. E.; Sepulchre, Rodolphe ULg

in Proceedings of the 7th IFAC Symposium on Nonlinear Control Systems (2007, August)

We introduce a characterization of contraction for bounded convex sets. For discrete-time multi-agent systems we provide an explicit upperbound on the rate of convergence to a consensus under the ... [more ▼]

We introduce a characterization of contraction for bounded convex sets. For discrete-time multi-agent systems we provide an explicit upperbound on the rate of convergence to a consensus under the assumptions of contractiveness and (weak) connectedness (across an interval). Convergence is shown to be exponential when either the system of the function characterizing the contraction is linear [less ▲]

Detailed reference viewed: 5 (0 ULg)
Full Text
See detailQuantitative palynology in late and latest Famennian swamp environments, an accurate tool for marine / non-marine correlation.
Streel, Maurice ULg

in Newsletter. Subcommission on Devonian Stratigraphy (1998), 15

Detailed reference viewed: 10 (1 ULg)
Full Text
Peer Reviewed
See detailQuantitative palynology of Famennian events in the Ardenne-Rhine Regions.
Streel, Maurice ULg

in Abhandlungen der Geologischen Bundesanstalt (1999), 54

Detailed reference viewed: 19 (1 ULg)
Full Text
See detailQuantitative palynology of latest Famennian events in the Sauerland.
Streel, Maurice ULg

in Newsletter. Subcommission on Devonian Stratigraphy (1998), 15

Detailed reference viewed: 12 (0 ULg)
See detailQuantitative palynology, a tool for characterizing mud
Roche, M.; Steemans, Philippe ULg; Streel, Maurice ULg

Conference (1990)

Detailed reference viewed: 4 (0 ULg)
Full Text
See detailA quantitative point of view of the concept of vulnerability
Brouyère, Serge ULg

in Zwahlen, François (Ed.) Vulnerability and risk mapping for the protection of carbonate (karst) aquifers, COST620 final report (2004)

Detailed reference viewed: 46 (4 ULg)