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See detailp27Kip1 independently promotes neuronal differentiation and migration in the cerebral cortex.
Nguyen, Laurent ULg; Besson, A.; Heng, J Ik-Tsen et al

in Bulletin et Mémoires de l'Académie Royale de Médecine de Belgique (2007), 162(5-6), 310-4

The generation of glutamatergic neurons by stem and progenitor cells is a complex process involving the tight coordination of multiple cellular activities, including cell cycle exit, initiation of ... [more ▼]

The generation of glutamatergic neurons by stem and progenitor cells is a complex process involving the tight coordination of multiple cellular activities, including cell cycle exit, initiation of neuronal differentiation and cell migration. The mechanisms that integrate these different events into a coherent program are not well understood. Here we show that the cyclin-dependent kinase inhibitor p27Kip1 plays an important role in neurogenesis in the mouse cerebral cortex, by promoting the differentiation and radial migration of cortical projection neurons. Importantly, p27Kip1 promotes neuronal differentiation and neuronal migration via two distinct mechanisms, which are themselves independent of the cell cycle regulatory function of p27Kip1. p27Kip1 inactivation by gene targeting or RNA interference results in neuronal differentiation and radial migration defects, demonstrating that p27Kip1 regulates cell migration in vivo. The differentiation defect, but not the migration defect, is rescued by overexpression of the proneural gene Neurogenin 2. p27Kip1 acts by stabilizing Neurogenin 2 protein, an activity carried by the N-terminal half of the protein. The migration defect resulting from p27Kp1 inactivation is rescued by blocking RhoA signalling, an activity that resides in the c-terminal half of p27Kip1. Thus, p27Kip1 plays a key role in cortical development, acting as a modular protein that independently regulates and couples multiple cellular pathways contributing to neurogenesis. [less ▲]

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See detailp27kip1 independently promotes neuronal differentiation and migration in the cerebral cortex.
Nguyen, Laurent ULg; Besson, Arnaud; Heng, Julian Ik-Tsen et al

in Genes & Development (2006), 20(11), 1511-24

The generation of neurons by progenitor cells involves the tight coordination of multiple cellular activities, including cell cycle exit, initiation of neuronal differentiation, and cell migration. The ... [more ▼]

The generation of neurons by progenitor cells involves the tight coordination of multiple cellular activities, including cell cycle exit, initiation of neuronal differentiation, and cell migration. The mechanisms that integrate these different events into a coherent developmental program are not well understood. Here we show that the cyclin-dependent kinase inhibitor p27(Kip1) plays an important role in neurogenesis in the mouse cerebral cortex by promoting the differentiation and radial migration of cortical projection neurons. Importantly, these two functions of p27(Kip1) involve distinct activities, which are independent of its role in cell cycle regulation. p27(Kip1) promotes neuronal differentiation by stabilizing Neurogenin2 protein, an activity carried by the N-terminal half of the protein. p27(Kip1) promotes neuronal migration by blocking RhoA signaling, an activity that resides in its C-terminal half. Thus, p27(Kip1) plays a key role in cortical development, acting as a modular protein that independently regulates and couples multiple cellular pathways contributing to neurogenesis. [less ▲]

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See detailP2P File Sharing for P2P Computing
Briquet, Cyril ULg; Dalem, Xavier ULg; Jodogne, Sébastien ULg et al

in Multiagent and Grid Systems (2009), 2009/5(2), 137-164

The transfer of large input data files in P2P computing Grids often leads to delays in Task completion times. Existing research related to this topic has been focused on the spatial grouping of Tasks, i.e ... [more ▼]

The transfer of large input data files in P2P computing Grids often leads to delays in Task completion times. Existing research related to this topic has been focused on the spatial grouping of Tasks, i.e. reuse of available data through data caching and data-aware scheduling. However, it tends to decrease the level of parallelism of Task execution. In this paper, this issue is addressed by integrating the BitTorrent P2P file sharing protocol, a novel Task selection scheduling algorithm, an existing online, data-aware Resource selection algorithm (similar to Storage Affinity), and caching support. These algorithms have been implemented in the Lightweight Bartering Grid middleware. The Java implementation relies exclusively on Free and Open Source data transfer software (Azureus, Apache FTP server, edtFTPj). The proposed data transfer architecture does not need Predictive Communications Ordering or an explicit deployment of an overlay network. It is also easily deployable. Our main contribution is the joint use of P2P computing and P2P file sharing technologies, enabling a highly scalable and adaptive data transfer architecture to support P2P computing. [less ▲]

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See detailP2P Implications on Web Surfing
Merciadri, Luca ULg

E-print/Working paper (2009)

P2P (Peer-to-Peer) technology comprises various ways to exchange information rapidly, each participant sharing a portion of his own resources. Anyway, despite of the numerous advantages of using P2P, a ... [more ▼]

P2P (Peer-to-Peer) technology comprises various ways to exchange information rapidly, each participant sharing a portion of his own resources. Anyway, despite of the numerous advantages of using P2P, a real problem is often encountered when using cheap internet connections: web surfing becomes so slow that it seems impossible to reach a web page, for the P2P’s user. It is especially the case when using connections with a low upload speed. The problem has also an importance, even if it is minor, when using high-speed connections (VDSL, ... ), as it is also a waste of capacity. [less ▲]

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See detailA P2X Ion Channel-triggered NF-{kappa}B Pathway Enhances TNF-{alpha}-induced IL-8 Expression in Airway Epithelial Cells.
Theatre, Emilie ULg; Bours, Vincent ULg; Oury, Cécile ULg

in American Journal of Respiratory Cell and Molecular Biology (2009)

Extracellular ATP, acting at P2Y and P2X receptors, has recently been shown to contribute to airway inflammation. Using different epithelial cell models, this study shows that ATP promotes TNF-alpha ... [more ▼]

Extracellular ATP, acting at P2Y and P2X receptors, has recently been shown to contribute to airway inflammation. Using different epithelial cell models, this study shows that ATP promotes TNF-alpha-elicited IL-8 expression through P2X ion channel-triggered Ca(2+) entry, leading to CaMK-dependent IKK activation and binding of active p65 to IL-8 gene promoter. [less ▲]

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See detailP2X(1)-mediated activation of extracellular signal-regulated kinase 2 contributes to platelet secretion and aggregation induced by collagen.
Oury, Cécile ULg; Toth-Zsamboki, Emese; Vermylen, Jos et al

in Blood (2002)

This study shows that mild platelet stimulation with collagen rapidly releases ATP, which activates the P2X(1)-PKC-ERK2 pathway. This process enhances further degranulation of the collagen-primed granules ... [more ▼]

This study shows that mild platelet stimulation with collagen rapidly releases ATP, which activates the P2X(1)-PKC-ERK2 pathway. This process enhances further degranulation of the collagen-primed granules allowing platelet aggregation to be completed. [less ▲]

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See detailP2X1 expressed on polymorphonuclear neutrophils and platelets is required for thrombosis in mice
Darbousset, Roxane; Delierneux, Céline ULg; Mezouar, Soraya et al

in Blood (2014), 124

Adenosine Triphosphate (ATP) and its metabolite, adenosine, are key regulators of polymorphonuclear neutrophils (PMNs) functions. PMNs have recently been implicated in the initiation of thrombosis. We ... [more ▼]

Adenosine Triphosphate (ATP) and its metabolite, adenosine, are key regulators of polymorphonuclear neutrophils (PMNs) functions. PMNs have recently been implicated in the initiation of thrombosis. We investigated the role of ATP and adenosine in PMN activation and recruitment at the site of endothelial injury. Following binding to the injured vessel wall, PMNs are activated and release elastase. The recruitment of PMNs and the subsequent fibrin generation and thrombus formation are strongly affected in mice deficient in the P2X1-ATP receptor and in wild-type mice treated with CGS 21680, an agonist of the A2A adenosine receptor or NF449 a P2X1 antagonist. Infusion of wild-type PMNs into P2X1-deficient mice increases fibrin generation but not thrombus formation. Restoration of thrombosis requires infusion of both platelets and PMNs from wild-type mice. In vitro, ATP activates PMNs, whereas CGS 21680 prevents their binding to activated endothelial cells. These data indicate that ATP contributes to PMN activation leading to their adhesion at the site of laser-induced endothelial injury, a necessary step leading to the generation of fibrin and subsequent platelet-dependent thrombus formation. Altogether, our study identifies previously unknown mechanisms by which ATP and adenosine are key molecules involved in thrombosis by regulating the activation state of PMNs. [less ▲]

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See detailThe P2X1 ion channel in platelets acts as a functional receptor for ATP and is weakly antagonized by ADP.
Oury, Cécile ULg; Toth-Zsamboki, Emese; Thys, Chantal et al

in Thrombosis and Haemostasis (2001)

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See detailP2X1 Ion Channels Promote Neutrophil Chemotaxis through Rho Kinase Activation
Lecut, Christelle ULg; Frederix, Kim ULg; Johnson, Daniel M et al

in Journal of Immunology (2009)

This study shows that activation of P2X1 ion channels by ATP promotes neutrophil chemotaxis, a process involving Rho kinase-dependent actomyosin-mediated contraction at the cell rear. These ion channels ... [more ▼]

This study shows that activation of P2X1 ion channels by ATP promotes neutrophil chemotaxis, a process involving Rho kinase-dependent actomyosin-mediated contraction at the cell rear. These ion channels may therefore play a significant role in host defense and inflammation. [less ▲]

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See detailP2X1 receptors as new regulators of neutrophil life span
Faccinetto, Céline ULg; Lecut, Christelle ULg; Jacobs, Nathalie ULg et al

in Journal of Thrombosis and Haemostasis [=JTH] (2007)

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See detailP2X1-induced activation of Ca2+ calmodulin leads to myosin light chain and ERK2 phosphorylation in human platelets.
Toth-Zsamboki, Emese; Oury, Cécile ULg; De Vos, Rita et al

in Journal of Thrombosis and Haemostasis [=JTH] (2003)

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See detailP2X1-mediated activation of Ca2+-calmodulin leads to myosin light chain and ERK2 phosphorylation in human platelets.
Toth-Zsamboki, Emese; Oury, Cécile ULg; De Vos, Rita et al

in Haematologica (2002), 87

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See detailP2X1-mediated ERK2 activation amplifies the collagen-induced platelet secretion by enhancing myosin light chain kinase activation.
Oury, Cécile ULg; Toth-Zsamboki, Emese; Cornelissen, Heidi et al

in Journal of Biological Chemistry (2003)

This study shows that, at low doses of collagen, glycoprotein VI activation leads to early protein kinase C- and MLC kinase-dependent platelet degranulation. Rapidly released ATP triggers P2X1 -mediated ... [more ▼]

This study shows that, at low doses of collagen, glycoprotein VI activation leads to early protein kinase C- and MLC kinase-dependent platelet degranulation. Rapidly released ATP triggers P2X1 -mediated Ca2+ influx, activating ERK2, in turn amplifying platelet secretion by reinforcing the early MLC kinase phosphorylation. Hence, the P2X1-ERK2-MLC axis contributes to collagen-induced platelet activation by enhancing platelet degranulation. [less ▲]

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See detailThe P2Y1 receptor antagonist adenosine-2',5'-diphosphate non-selectively antagonizes the platelet P2X1 ion channel.
Oury, Cécile ULg; Toth-Zsamboki, Emese; Tytgat, Jan et al

in Thrombosis and Haemostasis (2001)

This letter indicates a lack of specificity of a platelet P2Y1 receptor antagonist.

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See detailP3 panel summary: exozodiacal dust disks
Absil, Olivier ULg

Scientific conference (2009, September 18)

When observing an extrasolar planetary system, the most luminous component after the star itself is generally the light scattered and/or thermally emitted by a population of micron-sized dust grains ... [more ▼]

When observing an extrasolar planetary system, the most luminous component after the star itself is generally the light scattered and/or thermally emitted by a population of micron-sized dust grains. These grains are expected to be continuously replenished by the collisions and evaporation of larger bodies just as in our solar zodiacal cloud. Exozodiacal clouds (\exozodis") must therefore be seriously taken into account when attempting to directly image faint Earth-like planets (exoEarths, for short). This paper summarizes the oral contributions and discussions that took place during the Satellite Meeting on exozodiacal dust disks, in an attempt to address the following two questions: Do we need to solve the exozodi question? If yes, how to best solve it? [less ▲]

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See detailP300 and personality: an investigation with the Cloninger's model.
Hansenne, Michel ULg

in Biological Psychology (1999), 50(2), 143-55

The relationships between P300 and personality have been explored mainly in reference to the model of personality described by Eysenck because of its biological bases. Recently, Cloninger and his ... [more ▼]

The relationships between P300 and personality have been explored mainly in reference to the model of personality described by Eysenck because of its biological bases. Recently, Cloninger and his colleagues have proposed a model of personality based on four temperaments and three characters. The Temperament and Character Inventory (TCI) is a 226-item self-questionnaire developed to assess these seven dimensions of personality. In the present study, the relationships between these dimensions of personality and P300 have been investigated in 43 normal subjects. The results show that P300 amplitude is positively correlated with the novelty seeking dimension and negatively correlated with the harm avoidance dimension. In contrast, the other dimensions of the TCI were not related to P300 amplitude. Moreover, P300 latency and reaction time were not associated with the TCI dimensions of personality. This study confirms that personality is related to P300. [less ▲]

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See detailP300 event-related brain potential and personality in depression.
Hansenne, Michel ULg; Pitchot, William ULg; Pinto, Emmanuel ULg et al

in European Psychiatry (2000), 15(6), 370-7

P300 is an event-related brain potential (ERP) particularly interesting to the study of cognitive processes in normal subjects and in psychopathology. P300 has been applied in depression with ... [more ▼]

P300 is an event-related brain potential (ERP) particularly interesting to the study of cognitive processes in normal subjects and in psychopathology. P300 has been applied in depression with controversial results. A major source for these controversial results could result from the diversity of depressed patients included in the different studies. Supporting this assumption, impulsivity, blunted affect, suicidal behavior and psychotic features significantly influence P300 amplitude. However, no data are available on the possible influences of the personality of depressed patients on P300. Since personality is related to P300 in normal subjects, the aim of the present study is to investigate the relationship between ERPs (P200, N200, and P300) and the Temperament and Character Inventory (TCI) in 54 depressed patients. The main results of the study concern the absence of major correlations between personality dimensions as assessed by the TCI and ERP parameters among depressed patients. Only weak partial positive correlations relate N200 latency with harm avoidance, and P300 amplitude (Pz) with the self-directedness dimension. N200 amplitude is also negatively correlated to persistence. However, the preliminary nature of the presented results with respect to the weak statistical significance should be underlined. [less ▲]

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See detailP300 event-related potential and serotonin-1A activity in depression.
Hansenne, Michel ULg; Ansseau, Marc ULg

in European Psychiatry (1999), 14(3), 143-7

The identification of the brain structures and neurotransmitters responsible for the generation and/or modulation of P300 could lead to important clinical implications. Since serotonin disturbances seem ... [more ▼]

The identification of the brain structures and neurotransmitters responsible for the generation and/or modulation of P300 could lead to important clinical implications. Since serotonin disturbances seem to play a critical role in depression, the aim of the study was to assess the possible relationships between the P300 event-related brain potential and serotonergic activity in depression. The study was conducted among 45 major depressive inpatients, and serotonergic activity was assessed by prolactin (PRL) response to flesinoxan (a 5-HT1A agonist). Results showed a significant negative correlation between P300 amplitude and PRL response to flesinoxan (r = -0.40, P = 0.007 at Cz; r = -0.47, P = 0.001 at Pz). In contrast, both P300 latency and reaction time were not related to endocrine response. This study supports a role for serotonin-1A in the neurobiological modulation of P300 amplitude. [less ▲]

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See detailP300 in posttraumatic stress disorder.
Charles, G.; Hansenne, Michel ULg; Ansseau, Marc ULg et al

in Neuropsychobiology (1995), 32(2), 72-4

In the present study, P300 has been recorded in 26 subjects (15 women) 1 month after an aggression without organic complications. Among our sample, 16 subjects fulfilled DSM-III-R criteria for ... [more ▼]

In the present study, P300 has been recorded in 26 subjects (15 women) 1 month after an aggression without organic complications. Among our sample, 16 subjects fulfilled DSM-III-R criteria for posttraumatic stress disorder (PTSD) and 10 did not. P300 amplitude was significantly lower in the 16 PTSD subjects as compared to the 10 subjects without PTSD. This study supports information processing disturbances in PTSD. [less ▲]

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See detailThe p40* adhesin pseudogene of Mycoplasma bovis
Thomas, Anne; Linden, Annick ULg; Mainil, Jacques ULg et al

in Veterinary Microbiology (2004), 104(3-4), 213-217

An analogue of the adhesin gene p40 of Mycoplasma agalactiae was found in Mycoplasma bovis. Nucleotide sequence analysis of the p40* gene in M. bovis revealed the presence of a large deletion involving a ... [more ▼]

An analogue of the adhesin gene p40 of Mycoplasma agalactiae was found in Mycoplasma bovis. Nucleotide sequence analysis of the p40* gene in M. bovis revealed the presence of a large deletion involving a frameshift that causes premature truncation of the translated protein, indicating that p40* exists as a pseudogene in M. bovis. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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