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Peer Reviewed
See detailQualitative analysis of ten-dimensional lovelock cosmological models
Demaret, Jacques; De Rop, Yves ULg; Tombal, P. et al

in General Relativity & Gravitation (1992), 24

The Einstein-like field equations obtained from the variation of a Lagrangian containing linear, quadratic (Gauss-Bonnet) and quartic terms for a ten-dimensional cosmological model cannot be solved ... [more ▼]

The Einstein-like field equations obtained from the variation of a Lagrangian containing linear, quadratic (Gauss-Bonnet) and quartic terms for a ten-dimensional cosmological model cannot be solved analytically. However, we can reduce them to a system of dynamical equations for the “Hubble parameters”. The study of the mathematical properties of the fixed points of this system gives a qualitative picture of the behaviour of a class of possible solutions. The inclusion of a quartic term generates an extremely rich structure for the corresponding dynamical system. Some solutions are shown to exhibit the interesting property of dimensional reduction, which has been proposed as a possible explanation of the three-dimensional character of our universe. [less ▲]

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See detailQualitative analysis of the interactive decisions of three coaches involved in a “start to run” session
Cloes, Marc ULg; Dethioux, Sébastien

Conference (2012, July)

Introduction. A growing number of programs are implemented to enable a smooth resumption of physical activity. “Start to run” is a running program promoted by the athletics federation that has gained a ... [more ▼]

Introduction. A growing number of programs are implemented to enable a smooth resumption of physical activity. “Start to run” is a running program promoted by the athletics federation that has gained a great notoriety in Belgium. It proposes sessions of 10 weeks during which participants are trained to run 5 km without stop (10 km for those who are not beginners). No data seems to be available about the coaching process in this specific context of active leisure. The purpose of this study was to enlarge knowledge on this topic. Methods. Based on the principles of the qualitative research, we analyzed three sites: three groups involved in a Start to run session in different communities of the Liege’s area (Wallonia, Belgium). In all sites, data were collected before, during, at the end and 12 weeks after the session. They provided information on the context as well as on the process (coaches and participants behaviors and perceptions), and participants’ achievement and maintenance. In this paper, we will focus our analysis on the interactive decisions of the coaches. It will be based on the observation of three lessons in each site (2d, 5th and 8th weeks): one of the authors attended to the training session as participant observer. Moreover, we will also use data collected through interviews (description of the organization and content of the program) and questionnaires (feelings about the lessons). Participants were also requested to provide their perceptions about the lessons. As evidenced above, the validity of the analysis is guaranteed by the triangulation of the data. Results. The three coaches described a similar teaching model but only subject #2 pointed out technical drills. Only subject #3 respected the “official” program developed by the athletics federation. The two other adapted it according to their experience and purposes of their groups. All of them considered that they were providing enough feedback and were active. On the other hand, they thought themselves as needing to encourage more and to be more effective in group management. Globally, participants confirmed the opinions of their respective coaches but they seemed more critical in group #3, showing a lower satisfaction about the motivational behaviors and feedback. The observation pointed out some problems in the clarity of the explanations (subject #1) and some divergences were reported with the actors. Discussion. The triangulation of the data allows us to consider that the three coaches are doing a very good job and adapt themselves to the expectations and needs of the participants. The identification of the positive and negative aspects in each subject provides a basis to propose some recommendations. Moreover, we pointed out that encouraged to speak about their own teaching process, all coaches modified spontaneously their interactive decisions during the study. This underlines the interest of this systematic analysis. [less ▲]

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See detailQualitative and quantitative analyses of a pharmaceutical formulation produced by hot melt extrusion using Raman spectroscopy
Netchacovitch, Lauranne ULg; De Bleye, Charlotte ULg; Sacre, Pierre-Yves ULg et al

Poster (2014, May 15)

In the pharmaceutical industry, Hot Melt Extrusion (HME) is a recent technique used to integrate poor water soluble drugs in pharmaceutical formulations. Indeed, more and more active pharmaceutical ... [more ▼]

In the pharmaceutical industry, Hot Melt Extrusion (HME) is a recent technique used to integrate poor water soluble drugs in pharmaceutical formulations. Indeed, more and more active pharmaceutical ingredients (API) belong to the Biopharmaceutical Classification System (BCS) II and IV. Their integration in pharmaceutical solid forms is a big deal. HME processes increase the bioavailability and the solubility of those API by encompassing them in a polymeric carrier and by forming solid dispersions [1]. Moreover, in 2004, the FDA’s guidance initiative promoted the usefulness of Process Analytical Technology (PAT) tools when developing a manufacturing process. Vibrational spectroscopy is an appropriate PAT tool to analyze extrudates [2 – 3]. In this case, Raman spectroscopy, which belongs to vibrational spectroscopy, was used to analyze itraconazole extrudates qualitatively and quantitatively. During HME, the main objective is to develop solid dispersions by converting a crystalline API in an amorphous one, in order to improve its solubility and bioavailability [4]. According to Raman spectra, it is possible to identify the polymorphic form of the components in the extrudates by integrating or rationing the Raman bands that are characteristic of the API or by calculating the width at half intensity of some bands [5]. After determining the polymorphic form of the API, a quantitative method was developed in order to measure the ratio between the API and the polymer. Finally, chemical imaging was performed on extrudates to identify the distribution of the homogeneity of the API inside the polymer [6]. In conclusion, Raman spectroscopy is an appropriate tool to follow an extrusion process. By qualitative and quantitative analyses it is possible to determine the composition, the polymorphic form, the homogeneity, and the concentration of pharmaceutical matrices according to Raman fingerprint. References: [1] S. Shah et. al., Int J Pharm 453 (2013) 233 – 252. [2] L. Saerens et. al., Anal Chem 85 (2013) 5420 – 5429. [3] T. De Beer et. al., J Pharm Biomed Anal 48 (2008) 772 – 779. [4] A. Sarode et. al., Eur J Pharm Sci 48 (2013) 371 – 384. [5] E. Widjaja et. al., Eur J Pharm Sci 42 (2011) 45 – 54. [6] J. M. Amigo, Anal Bioanal Chem 398 (2010) 93 – 109. [less ▲]

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See detailQualitative and quantitative criteria for comfortable urban public spaces
Reiter, Sigrid ULg; De Herde, André

in Carmeliet, Jan; Hens, Hugo; Vermeir, Gerrit (Eds.) Research in building physics. Proceedings of the 2nd International Conference on Building Physics (2003, September)

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See detailQualitative and quantitative evaluation of bisindole usambarane alkaloids in Strychnos usambarensis roots by high performance liquid chromatography diode-array
Frederich, Michel ULg; Tits, Monique ULg; Angenot, Luc ULg

in Phytochemical Analysis [=PCA] (1998), 9(2), 63-66

A high performance liquid chromatographic method for the simultaneous determination of bisindole usambarane alkaloids from the roots of Strychnos usambarensis using a diode-array detector is proposed, The ... [more ▼]

A high performance liquid chromatographic method for the simultaneous determination of bisindole usambarane alkaloids from the roots of Strychnos usambarensis using a diode-array detector is proposed, The system, consisting of a RP-8 Select B column and a linear gradient elution with acetonitrile and acetate buffer allowed the separation of all the alkaloids in 20 min, Usambarensine was found to be the major tertiary alkaloid present in the roots, In order to demonstrate the possibility of quantifying the bisindole alkaloids in crude roots extracts, the quantitative evaluation of 3',4'-dihydrousambarensine, usambarensine and N-b-methylusambarensine was carried out. (C) 1998 John Wiley & Sons, Ltd. [less ▲]

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See detailQualitative and quantitative evaluation of equine respiratory mechanics by impulse oscillometry
Van Erck, Emmanuelle; Votion, Dominique ULg; Art, Tatiana ULg et al

in Equine Veterinary Journal (2006), 38(1), 52-58

Reasons for performing study: The long- established conventional reference technique (CRT) for measuring respiratory mechanics in horses lacks sensitivity and there is a need for further refinement in new ... [more ▼]

Reasons for performing study: The long- established conventional reference technique (CRT) for measuring respiratory mechanics in horses lacks sensitivity and there is a need for further refinement in new technology, such as the impulse oscillometry system (IOS). Objectives: To evaluate the potential use of the IOS as a clinical respiratory function test and compare it to the current CRT in horses suffering from common upper and lower airway dysfunctions. Methods: Six healthy horses were tested before and after induction of a unilateral nasal obstruction (UNO) or transient left laryngeal hemiplegia. (LLH). Six heaves-affected horses were tested in clinical remission and during a heaves crisis, before and after nebulisation of cumulative doses of a bronchodilator therapy (ipratropium bromide; IPB). Results: As opposed to the CRT, the IOS was able to detect partial upper airway obstruction (UAO) caused by UNO or LLH in resting horses, without differentiating both conditions. Upper airway obstruction caused an upward shift of resistance (R-rs) from 5 to 35 Hz without altering reactance (X-rs). As for the CRT, IOS respiratory parameters measured in heaves-affected horses in crisis differed significantly from values measured during remission. The difference in frequency-dependent behaviour of R-rs and X-rs allowed discrimination between upper and lower airway obstructions. Bronchodilator treatment induced significant dose-dependent changes in X-rs at 5 and 10 Hz, from the first dose. Total pulmonary resistance (R-L) and R-rs at 5 Hz were affected from the second dose and displayed similar sensitivity. Although post treatment R-L values were comparable to remission, R-rs and X-rs remained significantly different, characterising persistent peripheral obstruction. Conclusions: The IOS was more sensitive than the CRT in detecting partial UAO in resting horses and persistent post treatment peripheral dysfunction in heaves-affected horses. The IOS is a sensitive test that provides graded quantitative and qualitative information on disease-induced respiratory dysfunctions as well as on treatment efficiency in horses. Potential relevance: The IOS could represent a practical and sensitive alternative respiratory function test for routine clinical investigations of common airway obstructive diseases and therapy in horses. [less ▲]

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See detailQualitative approach of the general vacuum Bianchi VI and VII cosmological models near the singularity
De Rop, Yves ULg

in General Relativity & Gravitation (1989), 21

We first show that the chaos-generating terms are absent from the vacuum field equations in the case of the general Bianchi VI and VII cosmological models. According to recent studies, this proves that ... [more ▼]

We first show that the chaos-generating terms are absent from the vacuum field equations in the case of the general Bianchi VI and VII cosmological models. According to recent studies, this proves that the Kasnerian metric is a general solution for these models in the neighborhood of the initial singularity. Then, using a method developed by Jantzen, we reduce the field equations to a nonautonomous system of order two. A numerical integration leads to the explicit four-parameter asymptotic form of a general solution, which is indeed Kasnerian in the canonical invariant basis. [less ▲]

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See detailA qualitative assessment of the influence of bioturbation in Lake Baikal sediments
Martin, Patrick; Boes, Xavier; Goddeeris, Baudouin et al

in Global and Planetary Change (2005), 46(1-4), 87-99

The impact of bioturbation in Lake Baikal sediments, particularly on rhythmic layering and mixing, was assessed by studying the actual vertical distribution of benthic animals in continuous accumulation ... [more ▼]

The impact of bioturbation in Lake Baikal sediments, particularly on rhythmic layering and mixing, was assessed by studying the actual vertical distribution of benthic animals in continuous accumulation zones selected by seismic survey (Vydrino, Shoulder, Posolskoe Bank, Continent Ridge). To assess the influence of the bioturbation, animals were extracted from short cores and identified at the relevant taxonomic level. The faunal distribution is examined in parallel with the bioturbation tracks observed in thin section. Oligochaeta, Nematoda, Ostracoda, Copepoda, Gammaridae, Chironomidae and Hydrachnidia were found inhabiting the sediment. Among them, only oligochaete worms were assumed to have a significant impact on sediment mixing because of their "conveyor belt" feeding. The other two most abundantly sampled groups, nematods and copepods, belong to the interstitial fauna that has no significant impact on the vertical displacement of sediment particles and do not ingest the sediment. The presence of a benthic fauna as deep as 15 cm in the sediment indicates that the possibility of sediment disturbance by invertebrate activity cannot be dismissed in Lake Baikal. The effect of biological mixing is more limited in the deepest stations because the number of potential bioturbators is reduced, qualitatively as well as quantitatively. Located in the abyssal zone, Continent and Vydrino (but outside turbidites) deep stations appear to be most promising sediment records for tracking climate signal at high resolution. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailQualitative assessment of the purity of multi-walled carbon nanotube samples using krypton adsorption
Gommes, Cédric ULg; Noville, Francis ULg; Bossuot, Christophe et al

in Studies in Surface Science and Catalysis (2005), 160

Krypton is a subcritical vapour at the nitrogen boiling temperature. As such, its adsorption on crystalline surfaces leads to condensation steps, typical of type VI isotherms according to IUPAC, while its ... [more ▼]

Krypton is a subcritical vapour at the nitrogen boiling temperature. As such, its adsorption on crystalline surfaces leads to condensation steps, typical of type VI isotherms according to IUPAC, while its adsorption on rough surfaces is BET-like. Based on this property of krypton adsorption at 77 K, a methodology is proposed to determine the purity of carbon nanotubes samples. The method is tested on model samples obtained by mixing mechanically purified multi-walled carbon nanotubes with various amounts of the same catalyst as used for their synthesis. [less ▲]

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See detailQualitative bedside evaluation of the microcirculation via sidestream dark field imaging in dogs
Gommeren, Kris ULg; Allerton, Fergus ULg; Reynaud, Arthur et al

in Proceedings of the 22nd ECVIM-CA Congress (2012)

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See detailQualitative Comparison between the Quantum Calculations and Electrospray Mass Spectra of Complexes of Polyammonium Macrotricyclic Ligands with Dicarboxylic Acids
Collette, Caroline ULg; Dehareng, Dominique ULg; De Pauw, Edwin ULg et al

in Journal of the American Society for Mass Spectrometry (2001), 12(3), 304-16

The host-guest interactions play a very important role in chemical and biological processes. It is therefore important to be able to characterize these complexes. Electrospray mass spectrometry can be ... [more ▼]

The host-guest interactions play a very important role in chemical and biological processes. It is therefore important to be able to characterize these complexes. Electrospray mass spectrometry can be used to characterize the complex formation. It provides information on the mass and the charge of these ionic complexes. In this article, we show that the use of ab initio and semiempirical calculations, in addition to the results obtained by electrospray mass spectrometry, reveal to be a promising tool for the study of these noncovalent complexes. In this article, host-guest complexes formed by macropolycyclic polyammonium host molecules and dicarboxylic acids are studied. [less ▲]

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See detailQualitative comparison of 0.27T, 1.5T and 3T Magnetic Resonance Images of the normal equine foot.
Bolen, Géraldine ULg; Audigié, Fabrice; Spriet, Mathieu et al

in Journal of Equine Veterinary Science (2010), 30(1), 9-20

Magnetic resonance (MR) imaging has become an important diagnostic tool in the investigation of foot pain in horses. The aim of this study was to qualitatively compare ex-vivo MR images of the same equine ... [more ▼]

Magnetic resonance (MR) imaging has become an important diagnostic tool in the investigation of foot pain in horses. The aim of this study was to qualitatively compare ex-vivo MR images of the same equine feet obtained at three magnetic field strengths: 0.27, 1.5, and 3 tesla (T). Ten cadaver feet were used. All feet were imaged with two high-field (HF) systems (3T, 1.5T) and with a low-field (LF) system at 0.27T designed for standing horses. Images were acquired using similar pulse sequences in all 3 MR units. MR images were subjectively evaluated by three independent experienced image analysts for image quality and clarity of visualization of individual anatomical structures using a four-point grading scale. The images from all of the examinations were considered to be of diagnostic value except for the hoof capsule where substantial artifacts were present in LF images with distortion and loss of signal at the dorsal/distal aspect of the hoof capsule in LF images. Anatomical structure scoring values of images obtained at 3T and 1.5T were significantly greater than scores of images obtained at 0.27T. Scores for images obtained at 3T were significantly higher than those for images obtained at 1.5T. Mean score differences between 1.5T and 3T were higher for cartilage of the distal interphalangeal joint and for the ungular cartilages. [less ▲]

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See detailQualitative phenotypic analysis of yeast genes with unknown function.
Bianchi, M.; Vandenbol, Micheline ULg; Ngo, S. et al

Poster (1999)

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See detailQualitative phenotypic analysis of yeast genes with unknown function.
Bianchi, M.; Vandenbol, Micheline ULg; Ngo, S. et al

in Fourth Eurofan Meeting (1999)

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