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See detailThe chlorophyll a fluorescence induction curve in the green microalga Haematococcus pluvialis: Further insight into the nature of the P-S-M fluctuation and its relationship with the "low-wave" phenomenon at steady-state
Fratamico, Anthony ULg; Tocquin, Pierre ULg; Franck, Fabrice ULg

in Photosynthesis Research (in press)

Chlorophyll fluorescence is an information-rich signal which provides an access to the management of light absorbed by PSII. A good example of this is the succession of fast fluorescence fluctuations ... [more ▼]

Chlorophyll fluorescence is an information-rich signal which provides an access to the management of light absorbed by PSII. A good example of this is the succession of fast fluorescence fluctuations during light-induced photosynthetic induction after dark-adaptation. During this period, the fluorescence trace exhibits several inflexion points: O-J-I-P-S-M-T. Thereas the OJIP part of this kinetics has been the subject of many studies, the processes that underly the PSMT transient are less understood. Here, we report an analysis of the PSMT phase in the green microalga Haematococcus pluvialis in terms of electron acceptors and light use by photochemistry, fluorescence and non-photochemical quenching (NPQ). We identify additional sub-phases between P and S delimited by an inflexion point, that we name Q, found in the second time-scale. The P-Q phase expresses a transient photochemical quenching specifically due to alternative electron transport to oxygen. During the transition from Q to S, the NPQ increases and then relaxes during the S-M phase in about 1 min. It is suggested that this transient NPQ observed during induction is a high energy state quenching (qE) dependent the alternative electron transport to molecular oxygen. We further show that this NPQ is of the same nature than the NPQ, known as the low-wave phenomenon, which is transiently observed after a saturating light pulse given at steady-state. In both cases, the NPQ is oxygen-dependent. This NPQ is observed at external pH 6.0, but not at pH 7.5, which seems correlated with faster saturation of the PQ pool at pH 6.0. [less ▲]

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See detailChlorophyll Synthesis in Dark-Grown Pine Primary Needles
Schoefs, B.; Franck, Fabrice ULg

in Plant Physiology (1998), 118(4), 1159-68

The pigment content of dark-grown primary needles of Pinus jeffreyi L. and Pinus sylvestris L. was determined by high-performance liquid chromatography. The state of protochlorophyllide a and of ... [more ▼]

The pigment content of dark-grown primary needles of Pinus jeffreyi L. and Pinus sylvestris L. was determined by high-performance liquid chromatography. The state of protochlorophyllide a and of chlorophylls during dark growth were analyzed by in situ 77 K fluorescence spectroscopy. Both measurements unambiguously demonstrated that pine primary needles are able to synthesize chlorophyll in the dark. Norflurazon strongly inhibited both carotenoid and chlorophyll synthesis. Needles of plants treated with this inhibitor had low chlorophyll content, contained only traces of xanthophylls, and accumulated carotenoid precursors. The first form of chlorophyll detected in young pine needles grown in darkness had an emission maximum at 678 nm. Chlorophyll-protein complexes with in situ spectroscopic properties similar to those of fully green needles (685, 695, and 735 nm) later accumulated in untreated plants, whereas in norflurazon-treated plants the photosystem I emission at 735 nm was completely lacking. To better characterize the light-dependent chlorophyll biosynthetic pathway in pine needles, the 77 K fluorescence properties of in situ protochlorophyllide a spectral forms were studied. Photoactive and nonphotoactive protochlorophyllide a forms with emission properties similar to those reported for dark-grown angiosperms were found, but excitation spectra were substantially red shifted. Because of their lower chlorophyll content, norflurazon-treated plants were used to study the protochlorophyllide a photoreduction process triggered by one light flash. The first stable chlorophyllide photoproduct was a chlorophyllide a form emitting at 688 nm as in angiosperms. Further chlorophyllide a shifts usually observed in angiosperms were not detected. The rapid regeneration of photoactive protochlorophyllide a from nonphotoactive protochlorophyllide after one flash was demonstrated. [less ▲]

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See detailChlorophyll synthesis in relation to the assembly of photosystems
Franck, Fabrice ULg; Schoefs, Benoît

in Bulletin de la Société Royale des Sciences de Liège (1996), 65(4-5), 269-278

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See detailChlorophyll: natural sources, extraction methods and application for textile industry
Miazek, Krystian ULg; Remacle, Claire ULg; Richel, Aurore ULg et al

Conference (2014, October 14)

Chlorophyll is a photosynthetic pigment available abundantly in microalgae and terrestrial plants. This pigment found applications in pharmaceutical, cosmetic and food products as a wound healing ... [more ▼]

Chlorophyll is a photosynthetic pigment available abundantly in microalgae and terrestrial plants. This pigment found applications in pharmaceutical, cosmetic and food products as a wound healing, antioxidant or coloring agent. Recent reports suggest that chlorophyll can also be used as a biomordant to enhance the dyeing process of textile products, but also as a textile dye with antimicrobial properties. In this presentation, different aspects of chlorophyll production are discussed. Firstly, numerous plant biomass types as potential sources of chlorophyll are presented. Subsequently, different methods for chlorophyll extraction and separation from plant biomass are described. Finally, possibilities of chlorophyll implementation into textile products on industrial scale are evaluated. [less ▲]

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See detailChlorophylls and carotenoids in a fully habituated nonorganogenic callus of Beta vulgaris
Bisbis, B.; Dujardin, E.; Kevers, Claire ULg et al

in Biologia Plantarum (1994), 36(3), 443-449

A fully habituated (H) nonorganogenic sugar beet callus, subcultured in the light, did not contain detectable chlorophyll (Chl) nor carotenoid (Car). It accumulated some Car in the dark. Fluorescence ... [more ▼]

A fully habituated (H) nonorganogenic sugar beet callus, subcultured in the light, did not contain detectable chlorophyll (Chl) nor carotenoid (Car). It accumulated some Car in the dark. Fluorescence spectra indicated that this H callus also accumulated some protochlorophyllide which, however, was not well integrated into the protochlorophyllide-NADPH-photoreductase complex, and therefore not transformed into chlorophyllide in the light. The H callus showed no variable fluorescence which indicated absence of photosynthesis, and therefore it suggested a full heterotrophic behaviour of this peculiar callus line. A green hormone-dependent callus of the same sugar beet had normal fluorescence spectra and kinetics comparable to those of a green leaf. © 1994 Institute of Experimental Botany. [less ▲]

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See detailChloroplastic and mitochondrial metal homeostasis.
Nouet, Cécile ULg; Motte, Patrick ULg; Hanikenne, Marc ULg

in Trends in Plant Science (2011), 16(7), 395-404

Transition metal deficiency has a strong impact on the growth and survival of an organism. Indeed, transition metals, such as iron, copper, manganese and zinc, constitute essential cofactors for many key ... [more ▼]

Transition metal deficiency has a strong impact on the growth and survival of an organism. Indeed, transition metals, such as iron, copper, manganese and zinc, constitute essential cofactors for many key cellular functions. Both photosynthesis and respiration rely on metal cofactor-mediated electron transport chains. Chloroplasts and mitochondria are, therefore, organelles with high metal ion demand and represent essential components of the metal homeostasis network in photosynthetic cells. In this review, we describe the metal requirements of chloroplasts and mitochondria, the acclimation of their functions to metal deficiency and recent advances in our understanding of their contributions to cellular metal homeostasis, the control of the cellular redox status and the synthesis of metal cofactors. [less ▲]

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See detailChoc anaphylactique peri-anesthesique: mythe et realites
Van Den Bosch, Sabine ULg; Libbrecht, Dominique ULg; Lamy, Maurice ULg

in Revue Médicale de Liège (2004), 59(5), 336-44

Peri-anaesthetic anaphylactic shock is a fortunately rare event, which nevertheless often turns out to be life-threatening. Only fast recognition and reaction can permit to avoid its sometimes dramatic ... [more ▼]

Peri-anaesthetic anaphylactic shock is a fortunately rare event, which nevertheless often turns out to be life-threatening. Only fast recognition and reaction can permit to avoid its sometimes dramatic consequences. This implies, from the anaesthetist, good knowledge of the mechanisms, of the events'sequence, of the usual triggering drugs and, of course, of the anaphylactic shock's treatment. After such an accident has occured the patient should be referred to an allergy specialist in order to perform a thorough exploration, thus pointing out which drug is responsible for the reaction, and by which mechanism. Drugs to be banished in the future would so be identified and should be taken to the patient's as well as his general practician's knowledge. [less ▲]

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See detailChocolate : Natural but also chemical product…
Echterbille, Julien ULg

Conference (2014, November 12)

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See detailChoeur de femmes au coeur de la Savoie. Les annonciades d'Annecy entre clôture stricte et sociabilité urbaine (17e-18e s.)
Henneau, Marie-Elisabeth ULg; Piront, Julie

Book published by Société des Amis du Vieil Annecy (in press)

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See detailChoice of a suitable E-nose output variable for the continuous monitoring of an odour in the environment
Nicolas, Jacques ULg; Romain, Anne-Claude ULg; Monticelli, D. et al

in Gardner, J.; Persaud, K. (Eds.) Electronic noses and olfaction 2000. Proceedings of abstracts ISOEN 2000. (2000)

An array of tin-oxide sensors is used to continuously monitor different odour emissions in the environment. The paper presents some issues aiming at improving the portability and the user-friendliness of ... [more ▼]

An array of tin-oxide sensors is used to continuously monitor different odour emissions in the environment. The paper presents some issues aiming at improving the portability and the user-friendliness of the instrument as well as testing what kind of signal may be used to monitor the odour "intensity". Main results are the following. The test of various pre-processing data algorithms pointed out that the use of pure reference air could be avoided, as long as the sensors are allowed to periodically regenerate in the presence of ambient air. Sensor array in static contact with ambient air could be sufficient for the on-line monitoring, but the use of a controlled gas flow system to transfer the odour from the source is better to avoid the influence of air movement on the heated sensors. The control of the temperature and the humidity of the gas and the thermo-regulation of the sensor chamber don't seem essential, even for outdoor operation. When trying to build a regression model linking the odour intensity to the sensor signals, Partial Least Square (PLS) model gives better results with respect to Multi Linear Regression or Principal Component regression models. For an application around a landfill area, where sensor signals are compared to the personal feeling of the operator in the field, PLS gives a percentage of 71% correct intensity prediction. [less ▲]

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See detailChoice of an adjuvant for vaccination trials
Vermout, Sandy; Denis, M.; Losson, Bertrand ULg et al

in Annales de Médecine Vétérinaire (2003), 147(6), 393-401

The development of new vaccines, containing protective antigens that are more and more well characterized, is hindered by the lack of adjuvants able both to amplify immune response and to control it ... [more ▼]

The development of new vaccines, containing protective antigens that are more and more well characterized, is hindered by the lack of adjuvants able both to amplify immune response and to control it qualitatively. A number of tumors and infectious diseases could be treated with adjuvant preparations that would adequately intensify and modulate specific immune response; in particular, the possibility to specifically induce a Th1 response seems to be of paramount importance for the prevention and for the cure of these diseases. Furthermore, these adjuvants must be as safe as possible, not only for commercial applications, but also in the respect of laboratory animals' welfare. This review describes the different adjuvants presently used in vaccinology, classifying them following their chemical nature and presenting for each category the knowledge concerning their activity and toxicity. [less ▲]

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See detailChoice of key-words for a scientific paper.
VAN DAMME, Hendrik ULg; DETRY, Olivier ULg; Lerut, J et al

in Acta Chirurgica Belgica (2012), 112(2), 107

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See detailChoice of probing site for estimation of carcass lean percentage in Piétrain pig using the real-time ultrasound
Youssao, A. K. L.; Verleyen, Vincent ULg; Michaux, Charles ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2002), 6(4), 195-200

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See detailChoice of sedation according to ventilatory mode
Lamy, Maurice ULg; Damas, Pierre ULg; Joris, Jean ULg

in Journal of drug development (1991), 4(Suppl 3), 77-81

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See detailThe choice of the cooperative legal form: Any rationality?
Dufays, Frédéric ULg; O'Shea, Noreen

Conference (2015, July 04)

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See detailChoisir des cas exemplaires La Strategic litigation dans la lutte contre les discriminations liées à l’emploi en Belgique
Lejeune, Aude ULg; Orianne, Jean-François ULg

Conference (2011, July 07)

Dans plusieurs pays européens, les organismes publics nationaux de promotion de l’égalité des chances et de lutte contre les discriminations, appelés Equality Bodies, recourent à une pratique de « ... [more ▼]

Dans plusieurs pays européens, les organismes publics nationaux de promotion de l’égalité des chances et de lutte contre les discriminations, appelés Equality Bodies, recourent à une pratique de « Strategic litigation ». Inspirée par les pratiques anglo-saxonnes de common law, elle consiste à utiliser l’arène judiciaire pour faire avancer la jurisprudence dans certaines matières. Il s’agit plus précisément de sélectionner, parmi les cas individuels que traitent ces organismes, les dossiers qui sont exemplaires et qui pourront permettre aux magistrats de créer une jurisprudence positive dans certains domaines particuliers du droit. Au-delà de la contrainte budgétaire qui les empêche de défendre tous les cas, leur objectif est de se positionner comme un acteur stratégique en utilisant les cours et tribunaux comme des espaces d’action politique. Notre communication s’appuie sur une recherche de terrain qui traite des discriminations liées à l’emploi en Belgique. Notre matériau empirique se compose principalement d’entretiens et d’observations dans les deux centres chargés de la promotion de l’égalité des chances en Belgique (le Centre pour l’égalité des chances et la lutte contre le racisme et l’Institut pour l’égalité des femmes et des hommes) : entretiens de juristes de première et de seconde lignes, entretiens avec les plaignants, observation d’interactions aux « guichets » et au sein des équipes. En outre, nous avons réalisé une vaste analyse documentaire : consultation de dossiers depuis le dépôt de la plainte jusqu’au jugement, examen de rapports d’activité, de notes de travail internes aux services, etc. Enfin, nous avons procédé à des entretiens complémentaires d’avocats et de magistrats en charge de ces dossiers. Ce riche matériau nous permet d’analyser le processus de choix de cas exemplaires et ses implications. L’étude met tout d’abord en lumière les arguments auxquels se réfèrent les juristes qui sont amenés à sélectionner les dossiers en qualifiant certains cas « d’exemplaires ». Ensuite, elle examine l’articulation entre les revendications individuelles des plaignants, liées à leur propre histoire personnelle, avec les stratégies collectives de publicisation de ces centres. Enfin, elle interroge la stratégie judiciaire qui, dans un pays de droit continental, peut nourrir d’autres stratégies de lobbying politique en dehors des cours et tribunaux. [less ▲]

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