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See detailExteroceptive silent periods of temporalis muscle in headache
Schoenen, Jean ULg

in Van Steenberghe, D.; De Laat, A. (Eds.) EMG of jaw reflexes in man (1989)

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See detailExteroceptive suppression of temporalis muscle activity in chronic headache.
Schoenen, Jean ULg; Jamart, B.; Gerard, P. et al

in Neurology (1987), 37(12), 1834-6

Early (ES1) and late (ES2) exteroceptive suppression periods elicited by electrical stimulation of the labial commissure during teeth-clenching were recorded over the temporalis muscle in 45 headache ... [more ▼]

Early (ES1) and late (ES2) exteroceptive suppression periods elicited by electrical stimulation of the labial commissure during teeth-clenching were recorded over the temporalis muscle in 45 headache patients (25 tension headaches and 20 migraines) and 22 controls. Mean duration of ES2 for single shocks was significantly reduced in tension headache when compared with migraine or controls. At a stimulation rate of 2 Hz, ES2 was abolished in 40% of tension headache sufferers, but in none of the migraineurs. EMG analysis of temporalis late exteroceptive suppression might be a helpful diagnostic tool in functional headaches. Reduction of ES2 suggests that there is deficient activation or excessive inhibition of pontobulbar inhibitory interneurons which receive a strong input from limbic structures. ES2 might thus represent an interface between psychogenic and myogenic factors putatively involved in the pathogenesis of tension headache. [less ▲]

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See detailExteroceptive suppression of temporalis muscle activity in patients with chronic headache and in normal volunteers: methodology, clinical and pathophysiological relevance.
Schoenen, Jean ULg

in Headache (1993), 33(1), 3-17

Exteroceptive suppression of temporalis muscle activity was studied in patients with chronic headache and in healthy controls. Among different methods of recording, averaging 10 full-wave rectified EMG ... [more ▼]

Exteroceptive suppression of temporalis muscle activity was studied in patients with chronic headache and in healthy controls. Among different methods of recording, averaging 10 full-wave rectified EMG responses produces results with acceptable variability and discomfort. The late temporalis exteroceptive suppression period (ES2) is reduced on average in patients with chronic tension-type headache; this finding has been reproduced by several independent laboratories. Mean duration of temporalis ES2 is also diminished, but to a lesser degree, in daily drug abuse headache and, as shown by others, in episodic tension-type headache. It is normal in migraine between attacks, cluster headache and various types of symptomatic headaches. Temporalis ES2 may be decreased in untreated patients with major depression. In healthy volunteers, temporalis ES2 duration is reduced by a short-lasting painful stimulus to peripheral limbs after a delay of 50 to 60 ms, and by a sub-motor threshold electromagnetic stimulation to the contralateral cerebral cortex after a delay of 20 to 30 ms. In contrast, long-lasting trains of peripheral painful stimuli have no effect. Various pharmacological agents are able to modify temporalis ES2. Its duration is increased by 5-HT antagonists, but decreased by 5-HT uptake blockers. Pharmacological effects may differ between controls and patients. Considering these results and available data on the anatomo-functional organization of masticatory reflexes, we postulate that temporalis ES2 is a marker of the excitability of interneuronal nets in the ponto-medullary reticular formation. In chronic tension-type headache, excitability of these interneurons is decreased because of inadequate control by the serotonergic raphe magnus nucleus and the periaqueductal gray matter. Dysfunctioning of the latter structures might be caused by abnormal limbic inputs to the brain stem. Some steps of this pathophysiological hypothesis can be verified by modern neurophysiological techniques. [less ▲]

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See detailExteroceptive suppression of temporalis muscle activity in various types of headache.
Paulus, W.; Raubuchl, O.; Straube, A. et al

in Headache (1992), 32(1), 41-4

Exteroceptive suppression (ES) of temporalis muscle activity, particularly the multisynaptic ES2, has been reported to be significantly reduced in tension type headache, but not in migraine. We re ... [more ▼]

Exteroceptive suppression (ES) of temporalis muscle activity, particularly the multisynaptic ES2, has been reported to be significantly reduced in tension type headache, but not in migraine. We re-evaluated the methods of optimally analysing the single shock technique and its intra- and inter-individual variability in 26 normal subjects. These data were compared with the results in patients with migraine, post-lumbar puncture headache, headache due to meningitis, tension-type headaches in HIV infection and patients with symptomatic headache of various etiologies. ES2 was absent in about 50% of tension-type headache patients, but only in one normal subject. With the methods used here and when patients with absent ES2 were excluded, mean duration of ES2 was not significantly different between the various groups. It seems therefore necessary, in spite of increased discomfort for patients, to use complementary methods, such as averaging 16-32 responses and applying various stimulation sets, if one wants to increase the potency of temporalis ES2 as a diagnostic and pathophysiologic tool in headache. [less ▲]

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See detailExteroceptive suppression of temporalis muscle activity: methodological and physiological aspects.
Schoenen, Jean ULg

in Cephalalgia : An International Journal of Headache (1993), 13(1), 3-10

In recent years studies of the suppression of EMG activity in temporalis muscle induced by stimulation in the trigeminal territory have opened new perspectives in headache research. The various methods ... [more ▼]

In recent years studies of the suppression of EMG activity in temporalis muscle induced by stimulation in the trigeminal territory have opened new perspectives in headache research. The various methods that have been used in different laboratories are reviewed and some of the physiological modulations of temporalis exteroceptive suppression are described. Among different methods of recording, averaging 10 full-wave rectified EMG responses produces results with acceptable variability and discomfort. In order to obtain maximal responses the intensity of the stimulation should reach at least 20 mA. To avoid habituation of the second temporalis exteroceptive suppression period (ES2), the stimulation frequency has to be at 0.1 Hz or below. The level of voluntary contraction is not a critical variable as long as it reaches 50% of maximum. Some physiological variations of temporalis suppression are well documented. In females, ES2 is shorter during menstruation than at mid-cycle and correlated with the estradiol/progesterone ratio in plasma. Conditioning temporalis ES2 by a preceding peripheral stimulus markedly reduces its duration, which is partly reversible by naloxone. Various pharmacological agents are able to modify temporalis ES2: its duration is increased by 5-HT1 antagonists, but decreased by 5-HT uptake blockers; contradictory results have been obtained with acetylsalicylic acid. These results suggest that inhibitory brain-stem interneurons mediating temporalis ES2 are inhibited by serotonergic afferents, probably from the raphe magnus nucleus, and that the latter receives an excitatory input from the periaqueductal gray matter and other limbic structures, in part via opioid receptors. [less ▲]

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See detailExtinction debt and colonization credit: When both phenomena are integrated
Piqueray, Julien ULg; Cristofoli, Sara; Bisteau, Emmanuelle et al

Conference (2010)

Calcareous grasslands are among the most species-rich ecosystems in temperate countries. These ecosystems suffered a high fragmentation process during the last century. Fragmentation can lead to the ... [more ▼]

Calcareous grasslands are among the most species-rich ecosystems in temperate countries. These ecosystems suffered a high fragmentation process during the last century. Fragmentation can lead to the creation of an extinction debt in remaining habitat patches. In our study site, it was shown in a previous study that Fragmented habitat patches (area loss since 1965 >80%) exhibited an extinction debt in comparison to Stable habitat patches (area loss since 1965 <80%). However, human activities also created new habitat patches in the landscape and provided therefore opportunities for calcareous grassland plant species to colonize new sites. They also provide opportunities for studying species colonization abilities in the context of habitat restoration. We analyzed species richness in these new patches in comparison to old patches in order to detect colonization credit. When taking as reference Fragmented patches (that exhibit an extinction debt) or all old patches (Fragmented and Stable), we concluded to the occurrence of a colonization credit in New patches. However, when the reference is Stable patches (the less likely to exhibit an extinction debt) alone, no colonization credit could be detected. Moreover, correspondence analysis revealed that New patches were similar to old patches in term of species composition. These results are encouraging for restoration programs. They also showed that the presence of an extinction debt in reference habitats can lead to mistaken conclusion in restoration monitoring. Extinction debt occurrence should be taken into account in the choice of reference habitats for evaluation of restoration success. [less ▲]

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See detailL'extinction des peines
Jacobs, Ann ULg; Derre, Sylvie

in Postal Memorialis (2001)

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See detailL’extinction des servitudes : de nuances en précisions
Lecocq, Pascale ULg

in Journal des Tribunaux (2007)

Les servitudes du fait de l'homme peuvent s'éteindre par non usage trentenaire, celui-ci pouvant d'ailleurs être partiel. L'article étudie ce phénomène d'extinction, en le comparant à d'autres et ... [more ▼]

Les servitudes du fait de l'homme peuvent s'éteindre par non usage trentenaire, celui-ci pouvant d'ailleurs être partiel. L'article étudie ce phénomène d'extinction, en le comparant à d'autres et, notamment, à l'extinction judiciaire d'une servitude pour cause de perte de toute utilité. [less ▲]

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See detailExtinction law classification and lens redshift estimate by means of the principal component analysis
Jean, C.; Surdej, Jean ULg

in Astronomy and Astrophysics (2007), 471(3), 807-812

Aims. We propose a method based on the Principal Component Analysis (PCA) to classify and estimate the redshift of an extinction law in a distant gravitational lens galaxy. Such extinction laws are very ... [more ▼]

Aims. We propose a method based on the Principal Component Analysis (PCA) to classify and estimate the redshift of an extinction law in a distant gravitational lens galaxy. Such extinction laws are very poorly known and an efficient method to characterize them is badly needed. Methods. We first compute the principal axes of an exhaustive collection of redshifted theoretical extinction laws. Then, we project on these new axes the extinction law we wish to classify. The position of its projection among those redshifted extinction laws from the collection allows us to characterize it and to estimate its redshift. Results. Monte Carlo simulations show that the method is efficient and relatively precise for reasonably good signal-to-noise ratio data. The application of the method to a real case, the gravitational lens system SBS 0909+532, leads to very encouraging results. [less ▲]

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See detailThe extinction of ichthyosaurs is a facet of a major Cenomanian turnover in marine ecosystems
Fischer, Valentin ULg

Conference (2013, October)

Untangling geosphere-biosphere interactions is crucial to understand the biodiversity and how it might evolve in a changing environment. But little is known about the possible impact of environmental ... [more ▼]

Untangling geosphere-biosphere interactions is crucial to understand the biodiversity and how it might evolve in a changing environment. But little is known about the possible impact of environmental changes on animals occupying the highest levels of the marine trophic chains. The Cretaceous period offers a fantastic opportunity to investigate such relationship, being characterized by a globally warm but changing climate and a diverse assemblage of aquatic reptiles that underwent profound modifications during this period, ultimately permitting the diversification of the animals dominating nowadays marine ecosystems. The origin, magnitude and nature of these turnovers are poorly understood and have rarely been investigated in a global canvas. Especially, how and why ichthyosaurs, the ‘fish-shaped’ marine reptiles, went extinct at the beginning of the Late Cretaceous has been a mystery for decades. Previous assessments of their diversity suggested ichthyosaurs were already on the decline since the end of the Jurassic; their final extinction was therefore regarded as anecdotal. Several theories have proposed unique biological drivers to this event, including a break in the food chain or competition with other marine vertebrates. The reassessment of the taxonomy, phylogeny and paleoecology Cretaceous ichthyosaurs from Eurasia tells a much different story. Ichthyosaurs were ecologically and taxonomically diverse in several Eurasian ecosystems up to the latest Early Cretaceous. This revision also reveals that their extinction is diachronic, being staggered over four phases that span the entire Cenomanian stage. Detailed comparison with other groups suggests the multiphased extinction of ichthyosaurs is not an isolated event, as was previously assumed, but correlates with profound, multiphased turnovers among other marine animals, such as microplankton, rudists, ammonoids, and pythonomorphs. The diversity and contemporaneity of the biotic responses suggest worldwide physicochemical drivers for this profound reorganization of the marine ecosystems. The extinction of ichthyosaurs therefore appears as one of the facets of a much wider event that affected most of the marine ecosystems during the Cenomanian. [less ▲]

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See detailExtinctions et renouvellements fauniques chez les reptiles marins du Crétacé
Bardet, Nathalie; Fischer, Valentin ULg; Jouve, Stéphane et al

Conference (2011, December)

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See detailExtra-solar planet imaging: ground vs space based coronagraphs
Hanot, Charles ULg; Absil, Olivier ULg; Boccaletti, A. et al

Conference (2010, October 28)

In the context of exoplanet detection, a large majority of the 400 detected exoplanets have been found by indirect methods. Today, progress in the field of high contrast and angular resolution imaging has ... [more ▼]

In the context of exoplanet detection, a large majority of the 400 detected exoplanets have been found by indirect methods. Today, progress in the field of high contrast and angular resolution imaging has allowed direct images of several exoplanetary systems to be taken (cf. HR 8799, Fomalhaut and β Pic). In the near future, several new instruments are going to dramatically improve our sensitivity to exoplanet detection. Among these, SPHERE (Spectro Polarimetric High contrast Exoplanet REsearch) at the VLT, MIRI (Mid Infra-Red Instrument) onboard JWST and EPICS at the ELT will be equipped with coronagraphs to reveal faint objects in the vicinity of nearby stars. We made use of the Lyon group (COND) evolutionary models of young (sub-)stellar objects and exoplanets to compare the sensitivities of these different instruments using their estimated coronagraphic profiles. From this comparison, we present a catalogue of targets which are particularly well suited for the different instruments. [less ▲]

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See detailExtra-solar planet imaging: ground vs. space based coronagraphs
Hanot, Charles ULg

Conference (2010, October 28)

In the context of exoplanet detection, a large majority of the 400 detected exoplanets have been found by indirect methods. Today, progress in the field of high contrast and angular resolution imaging has ... [more ▼]

In the context of exoplanet detection, a large majority of the 400 detected exoplanets have been found by indirect methods. Today, progress in the field of high contrast and angular resolution imaging has allowed direct images of several exoplanetary systems to be taken (cf. HR 8799, Fomalhaut and β Pic). In the near future, several new instruments are going to dramatically improve our sensitivity to exoplanet detection. Among these, SPHERE (Spectro Polarimetric High contrast Exoplanet REsearch) at the VLT, MIRI (Mid Infra-Red Instrument) onboard JWST and EPICS at the ELT will be equipped with coronagraphs to reveal faint objects in the vicinity of nearby stars. We made use of the Lyon group (COND) evolutionary models of young (sub-)stellar objects and exoplanets to compare the sensitivities of these different instruments using their estimated coronagraphic profiles. From this comparison, we present a catalogue of targets which are particularly well suited for the different instruments. [less ▲]

Detailed reference viewed: 17 (5 ULg)
See detailExtra-Terrestrial Observations: Reports of national space-research programs 381
Swings, Polydore ULg

in Transactions of the International Astronomical Union. Series B, Proceedings of the general assembly (1962), 11

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See detailAn Extra-trees-based Automatic Target Recognition Algorithm
Pisane, Jonathan ULg; Marée, Raphaël ULg; Ries, Philippe ULg et al

in To appear in Proc. International Radar Conference (2009)

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See detailExtracellular amygdala excitatory and inhibitory amino acids change after acute ethanol administration
Quertemont, Etienne ULg; De Witte, Philippe

in Alcohol & Alcoholism (1995), 30

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See detailExtracellular amygdala taurine can be conditioned to stimuli associated with ethanol
Quertemont, Etienne ULg; de Neuville, Jessica; De Witte, Philippe

in Alcoholism, Clinical & Experimental Research (1996), 20

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See detailExtracellular amygdala taurine can be conditioned to stimuli associated with ethanol
Quertemont, Etienne ULg; de Neuville, Jessica; De Witte, Philippe

in Alcoholism, Clinical & Experimental Research (1996), 20

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See detailExtracellular catalase production by Aspergillus phoenicis.
Kacem-Chaouche, N.; Meraihi, Z.; Destain, Jacqueline ULg et al

Poster (2004, May)

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See detailThe extracellular chaperone clusterin potently inhibits human lysozyme amyloid formation by interacting with prefibrillar species
Kumita, Janet R.; Poon, Stephen; Caddy, Gemma L. et al

in Journal of Molecular Biology (2007), 369

We have studied the effects of the extracellular molecular chaperone, clusterin, on the in vitro aggregation of mutational variants of human lysozyme, including one associated with familial amyloid ... [more ▼]

We have studied the effects of the extracellular molecular chaperone, clusterin, on the in vitro aggregation of mutational variants of human lysozyme, including one associated with familial amyloid disease. The aggregation of the amyloidogenic variant I56T is inhibited significantly at clusterin to lysozyme ratios as low as 1:80 (i.e. one clusterin molecule per 80 lysozyme molecules). Experiments indicate that under the conditions where inhibition of aggregation occurs, clusterin does not bind detectably to the native or fibrillar states of lysozyme, or to the monomeric transient intermediate known to be a key species in the aggregation reaction. Rather, it seems to interact with oligomeric species that are present at low concentrations during the lag (nucleation) phase of the aggregation reaction. This behavior suggests that clusterin, and perhaps other extracellular chaperones, could have a key role in curtailing the potentially pathogenic effects of the misfolding and aggregation of proteins that, like lysozyme, are secreted into the extracellular environment. [less ▲]

Detailed reference viewed: 45 (1 ULg)