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See detailInterplay between non-photochemical plastoquinone reduction and re-oxidation in pre-illuminated Chlamydomonas reinhardtii: a chlorophyll fluorescence study
Houyoux, Pierre-Alain; Ghysels, Bart ULiege; Lecler, Renaud ULiege et al

in Photosynthesis Research (2011), 110

In photosynthetic eukaryotes, the redox state of the plastoquinone (PQ) pool is an important sensor for mechanisms that regulate the photosynthetic electron transport. In higher plants, a multimeric ... [more ▼]

In photosynthetic eukaryotes, the redox state of the plastoquinone (PQ) pool is an important sensor for mechanisms that regulate the photosynthetic electron transport. In higher plants, a multimeric nicotinamide adenine dinucleotide (phosphate) (NAD(P))H dehydroge- nase (NDH) complex and a plastid terminal oxidase (PTOX) are involved in PQ redox homeostasis in the dark. We recently demonstrated that in the microalgae Chla- mydomonas reinhardtii, which lacks the multimeric NDH complex of higher plants, non-photochemical PQ reduction is mediated by a monomeric type-II NDH (Nda2). In this study, we further explore the nature and the importance of non-photochemical PQ reduction and oxidation in relation to redox homeostasis in this alga by recording the ‘dark’ chlorophyll fluorescence transients of pre-illuminated algal samples. From the observation that this fluorescence tran- sient is modified by addition of propyl gallate, a known inhibitor of PTOX, and in a Nda2-deficient strain we conclude that it reflects post-illumination changes in the redox state of PQ resulting from simultaneous PTOX and Nda2 activity. We show that the post-illumination fluo- rescence transient can be used to monitor changes in the relative rates of the non-photochemical PQ reduction and reoxidation in response to different physiological situa- tions. We study this fluorescence transient in algae acclimated to high light and in a mutant deficient in mitochondrial respiration. Some of our observations indi- cate that the chlororespiratory pathway participates in redox homeostasis in C. reinhardtii. [less ▲]

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See detailInterplay between Nonequilibrium and Equilibrium Spin Torque Using Synthetic Ferrimagnets
Klein, Christian; Petitjean, Cyril ULiege; Waintal, Xavier

in PHYSICAL REVIEW LETTERS (2012), 108(8), 086601-5

We discuss the current induced magnetization dynamics of spin valves F-0 vertical bar N vertical bar SyF where the free layer is a synthetic ferrimagnet SyF made of two ferromagnetic layers F-1 and F-2 ... [more ▼]

We discuss the current induced magnetization dynamics of spin valves F-0 vertical bar N vertical bar SyF where the free layer is a synthetic ferrimagnet SyF made of two ferromagnetic layers F-1 and F-2 coupled by RKKY exchange coupling. When the magnetic moment of the outer layer F-2 dominates the magnetization of the SyF, the sign of the effective spin torque exerted on the layer F-1 is controlled by the coupling's strength: for weak coupling the spin torque tends to antialign F-1's magnetization with respect to the pinned layer F-0. At large coupling the situation is reversed and tends to align F-1 with respect to F-0. At intermediate coupling, numerical simulations reveal that the competition between these two incompatible limits leads generically to spin torque oscillator (STO) behavior. The STO is found at zero magnetic field, with very significant amplitude of oscillations and frequencies up to 50 GHz or higher. [less ▲]

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See detailInterplay between Penicillin-binding proteins and SEDS proteins promotes bacterial cell wall synthesis.
Leclercq, Sophie ULiege; Derouaux, Adeline ULiege; Olatunji, Samir ULiege et al

in Scientific Reports (2017), 7

Bacteria utilize specialized multi-protein machineries to synthesize the essential peptidoglycan (PG) cell wall during growth and division. The divisome controls septal PG synthesis and separation of ... [more ▼]

Bacteria utilize specialized multi-protein machineries to synthesize the essential peptidoglycan (PG) cell wall during growth and division. The divisome controls septal PG synthesis and separation of daughter cells. In E. coli, the lipid II transporter candidate FtsW is thought to work in concert with the PG synthases penicillin-binding proteins PBP3 and PBP1b. Yet, the exact molecular mechanisms of their function in complexes are largely unknown. We show that FtsW interacts with PBP1b and lipid II and that PBP1b, FtsW and PBP3 co-purify suggesting that they form a trimeric complex. We also show that the large loop between transmembrane helices 7 and 8 of FtsW is important for the interaction with PBP3. Moreover, we found that FtsW, but not the other flippase candidate MurJ, impairs lipid II polymerization and peptide cross-linking activities of PBP1b, and that PBP3 relieves these inhibitory effects. All together the results suggest that FtsW interacts with lipid II preventing its polymerization by PBP1b unless PBP3 is also present, indicating that PBP3 facilitates lipid II release and/or its transfer to PBP1b after transport across the cytoplasmic membrane. This tight regulatory mechanism is consistent with the cell's need to ensure appropriate use of the limited pool of lipid II. [less ▲]

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See detailThe interplay between phonology and syntax in French-speaking children with SLI
Parisse, Christophe; Maillart, Christelle ULiege

in International Journal of Language & Communication Disorders (2008), 43

Background. This study investigated the relationship between phonological and syntactic disorders of French-speaking children with SLI in production. Aims. This article compares three theories (pure ... [more ▼]

Background. This study investigated the relationship between phonological and syntactic disorders of French-speaking children with SLI in production. Aims. This article compares three theories (pure phonological theory, surface theory and mapping theory) of language developmental disorders, all of which view phonological difficulties as the main reason for the children’s problems. Methods and procedures. The linguistic parameters (salience, phonological complexity, syntactic complexity, lexical/functional, semantic/syntactic) (that are fundamental) to these theories were identified. The validity of these parameters was then tested against the phonological and syntactic results obtained by children with SLI and control children. Nine syntactic categories were tested. Outcomes and results. Phonological complexity was the only parameter whose importance was confirmed, and this was only for phonological results. Syntactic complexity did not correlate significantly with children’s difficulties, and the importance of phonological salience was not confirmed for French-speaking children. Mixed results were obtained for the other parameters, including negative correlations, which may call for different explanations. Conclusions. No theory fully explained the observed outcomes. Pure phonological theory was the most parsimonious, but could not explain all the results. [less ▲]

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See detailInterplay between spontaneous and induced brain activity during human non-rapid eye movement sleep.
Dang Vu, Thien Thanh ULiege; Bonjean, Maxime; Schabus, Manuel et al

in Proceedings of the National Academy of Sciences of the United States of America (2011), 108(37), 15438-43

Humans are less responsive to the surrounding environment during sleep. However, the extent to which the human brain responds to external stimuli during sleep is uncertain. We used simultaneous EEG and ... [more ▼]

Humans are less responsive to the surrounding environment during sleep. However, the extent to which the human brain responds to external stimuli during sleep is uncertain. We used simultaneous EEG and functional MRI to characterize brain responses to tones during wakefulness and non-rapid eye movement (NREM) sleep. Sounds during wakefulness elicited responses in the thalamus and primary auditory cortex. These responses persisted in NREM sleep, except throughout spindles, during which they became less consistent. When sounds induced a K complex, activity in the auditory cortex was enhanced and responses in distant frontal areas were elicited, similar to the stereotypical pattern associated with slow oscillations. These data show that sound processing during NREM sleep is constrained by fundamental brain oscillatory modes (slow oscillations and spindles), which result in a complex interplay between spontaneous and induced brain activity. The distortion of sensory information at the thalamic level, especially during spindles, functionally isolates the cortex from the environment and might provide unique conditions favorable for off-line memory processing. [less ▲]

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See detailInterplay between the electronic and dynamical properties of barium titanate
Ghosez, Philippe ULiege; Gonze, X.; Michenaud, J. P.

in Advanced in Computational Materials Science - II (1998)

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See detailInterplay of anisotropy and competing correlated pinning mechanisms in the angular dependence of the irreversible magnetization of YBa2Cu3O7 crystals
Silhanek, Alejandro ULiege; Civale, L.

in Physica C: Superconductivity (2000), 341(Part 2), 1227-1228

We measured the angular dependence of the irreversible magnetization of a YBa2Cu3O7 single crystal with columnar defects (CD) inclined with respect to the c-axis. At temperatures T greater than or equal ... [more ▼]

We measured the angular dependence of the irreversible magnetization of a YBa2Cu3O7 single crystal with columnar defects (CD) inclined with respect to the c-axis. At temperatures T greater than or equal to 40K and high fields we observe a sharp maximum centered at the tracks' direction. At T less than or equal to 20K the behavior is quite different. At high fields a broad bump at the tracks' direction is still visible, but its height is small and it appears only as a perturbation to the angular dependence due to material anisotropy. However, by performing the usual anisotropic rescaling (Blatter et al., Phys. Rev. Lett. 68, 875, 1992) we recover the strong unidirectional effects due to CD's. [less ▲]

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See detailThe interplay of regional systems of innovation, strategic alliances and open innovation
Segers, Jean ULiege

Doctoral thesis (2017)

Modern biotechnology is a driving force and a full grown industry in the international economy with ongoing and rapid innovations. The emphasis of this dissertation is on the valorization of red biotech ... [more ▼]

Modern biotechnology is a driving force and a full grown industry in the international economy with ongoing and rapid innovations. The emphasis of this dissertation is on the valorization of red biotech, i.e. pharmaceutical and healthcare applications. Belgium has firmly established itself as an international red biotechnology country, with a world class biotechnology industry in the Flanders and Wallonia bioRegions. Developing a domestic biotechnology industry - and hence new biotechnology firms - can be influenced by regional policy. The pharmaceutical-biotechnology regional and sectoral innovation system is characterized as an international and dynamic network architecture involving numerous players engaged in drug discovery. Regional governments and dedicated public and private network organizations have supported emerging new biotechnology firms by providing critical resources and by promoting an institutional environment that has enabled partnerships between universities, highly specialized research centers, small science based academic spin-offs and corporate spin-outs and large global pharmaceutical companies. Both policy and big firms look at the new biotechnology firms from a strategic point of view. The policy objective is the emergence of new and sustainable firms in the region; the big firms objective is the filling or renewal of the pipelines of products. New biotechnology firms are both beneficiaries and targets of strategic partnering alliances with large and global (bio)pharmaceutical companies. A number of the Belgian new biotechnology firms hold a nodal position as “ most preferred partner ” with multiple alliances in dynamic R&D networks. They have a high degree of integration into global technological networks through strategic alliances. Strategic alliances and open innovation are commonly leveraged. Despite their small size and relative immaturity, some of the new biotechnology firms are able to adopt innovative business models by providing R&D and services to large biopharmaceutical companies and by cooperating with them through open innovation. [less ▲]

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See detailInterplay of structural and electronic stabilizing factors in neutral and cationic phosphine protected Au13 clusters
Fresch, Barbara ULiege; Hanozin, Emeline ULiege; Dufour, Fabien ULiege et al

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2012), 66(12),

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See detailThe interplay of two single nucleotide polymorphisms in the CACNA1A gene may contribute to migraine susceptibility.
D'Onofrio, Mara; Ambrosini, Anna; Di Mambro, Alessandra et al

in Neuroscience Letters (2009), 453(1), 12-5

Migraine is a common disorder with a significant genetic component. Mutations in the CACNA1A gene are found in hemiplegic migraine (HM). Basilar-type (BM), another subtype of migraine with aura, differs ... [more ▼]

Migraine is a common disorder with a significant genetic component. Mutations in the CACNA1A gene are found in hemiplegic migraine (HM). Basilar-type (BM), another subtype of migraine with aura, differs from HM only by the absence of motor deficits. BM and HM may thus share common genetic features. In the present study, two single nucleotide polymorphisms (SNPs) of the CACNA1A gene were characterized in a population of migraine patients and healthy controls. The polymorphisms, E918D, predicting a glutamic acid-to-aspartic acid substitution at codon 918 and E993V, predicting a glutamic acid-to-valine substitution at codon 993, were frequently detected among patients and controls. Seven BM, 10 SHM, 5 FHM, 57 migraine with typical aura, 32 migraine without aura patients and 107 healthy controls were screened. The E918D and E993V SNPs were found in 30/117 (25.6%) and 32/117 (27.3%) migraine patients, respectively. The prevalence of these SNPs taken separately was not significantly different from that of control subjects (n=28/107, 26.2% for E918D; n=29/107 for E993V, 27.1%) neither for the total migraine population nor for the various migraine subtypes. By contrast, coexistence of both SNPs was more frequent in migraineurs (25/117, 21%) than in healthy controls (12/107, 11%; p=0.048), a difference that was significant for every migraine subtype. This result suggests that the interplay of minor genetic variants such as single nucleotide polymorphisms may influence the P/Q-type calcium channel function in several subtypes of migraine. [less ▲]

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See detailInterpleural, intercostal and thoracic epidural analgesia
Joris, Jean ULiege

in Current Opinion in Anaesthesiology (1991), 4

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See detailInterpolation of SLA Using the Data-Interpolating Variational Analysis in the Coastal Area of the NW Mediterranean Sea
Troupin, Charles ULiege; Barth, Alexander ULiege; Beckers, Jean-Marie ULiege et al

Poster (2013, October 07)

The spatial interpolation of along-track Sea-Level Anomalies (SLA) data to produce gridded map has numerous applications in oceanography (model validation, data assimilation, eddy tracking, ...). Optimal ... [more ▼]

The spatial interpolation of along-track Sea-Level Anomalies (SLA) data to produce gridded map has numerous applications in oceanography (model validation, data assimilation, eddy tracking, ...). Optimal Interpolation (OI) is often the preferred method for this task, as it leads to the lowest expected error and provides an error field associated to the analyzed field. However, the method suffers from limitations such as the numerical cost (due to the inversion of covariance matrices) as well as the isotropic covariance function, generally employed in altimetry. The Data-Interpolating Variational Analysis (DIVA) is a gridding method based on the minimization of a cost function using a finite-element technique. The cost function penalizes the departures from observations, the smoothness of the gridded field and physical constraints (advection, diffusion, ...). It has been shown that DIVA and OI are equivalent (provided some assumptions on the covariances are made), the main difference is that in DIVA, the covariance function is not explicitly formulated. The technique has been previously applied for the creation of regional hydrographic climatologies, which required the processing of a large number of data points. In this work we present the application and adaptation of Diva to the analysis of SLA in the Mediterranean Sea and the production of weekly maps of SLA in this region. The peculiarities of SLA along-track data are addressed: • number of observations: the finite-element technique coupled to improvements in the matrix inversion (parallel or iterative solvers) lead to a decrease of the computational time, meaning that sub-sampling of the initial data set is not required. • quality of the different missions: the weight attributed to each data point can be easily set according to the satellite that provided the observations, so that different measurement noise variances are considered. • spatial correlation scale: it varies spatially in the domain according to the value of the Rossby radius of deformation. • long-wavelength errors: each data point is associated a class, and a detrending technique allows the determination of the trend for each class, leading to a reduction of the inconsistencies between missions. • anisotropy of physical coastal features: a pseudo-velocity field derived from regional bathymetry enhances the correlations along the main currents. Particular attention will be paid to the influence of this constraint in the coastal area. The analysis and error fields obtained over the Mediterranean Sea are compared with the available gridded products from AVISO. Different ways to compute the error field are compared. The impact of the use of multiple missions to prepare the gridded fields is also examined. In situ measurements from an intensive multi-sensor experiment carried out north of the Balearic Islands in May 2009 serve to assess the quality of the gridded fields in the coastal area. [less ▲]

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See detailInterpolation schemes for geometrically exact beams: A motion approach
Sonneville, Valentin; Bruls, Olivier ULiege; Bauchau, Olivier A.

in International Journal for Numerical Methods in Engineering (in press)

This paper focuses on the interpolation of the kinematic fields describing the configuration of geometrically exact beams, namely, the position and rotation fields. Two kinematic representations are ... [more ▼]

This paper focuses on the interpolation of the kinematic fields describing the configuration of geometrically exact beams, namely, the position and rotation fields. Two kinematic representations are investigated: the classical approach that treats the displacement and rotation fields separately and the motion approach that treats those two fields as a unit. The latter approach is found to be more consistent with the kinematic description of beams. Then, two finite element interpolation strategies are presented and contrasted. The first interpolates the displacement and rotation fields separately, whereas the second interpolates both fields as a unit, in a manner consistent with the motion approach. The performance of both strategies is evaluated in light of the fundamental requirements for the convergence of the finite element method: the ability to represent rigid-body motions and constant strain states. It is shown that the traditional uncoupled interpolation scheme for the position field approximates that based on the motion approach and that the coupling induced by the interpolation of motion yields superior convergence rates for the representation of constant strain states. This property is known to lead to finite elements that are less prone to the locking phenomenon. [less ▲]

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See detailInterpolymer radical coupling: A toolbox complementary to controlled radical polymerization
Debuigne, Antoine ULiege; Hurtgen, Marie ULiege; Detrembleur, Christophe ULiege et al

in Progress in Polymer Science (2012), 37(7), 1004-1030

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular ... [more ▼]

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system. [less ▲]

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See detailInterpretatio : traduction ou assimilation ? La pratique dédicatoire comme révélateur
Paul, Stéphanie ULiege

Conference (2013, January 24)

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See detailInterpretation and modelling of multi-tracer tests in heterogeneous geological media
Dassargues, Alain ULiege

in Peters, N. E.; Coudrain-Ribstein, A. (Eds.) Hydrochemistry (Proc. of the Rabat Symposium) (1997)

Detailed reference viewed: 21 (6 ULiège)