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See detailDurito, een cyber-ridder op pantoffels
Vanden Berghe, Kristine ULg

in Lie, Nadia; D'haen, Theo (Eds.) Zorro & co. Populaire personages en het koloniale verleden (2002)

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See detailDurkheim et la littérature
Ledent, David ULg

Scientific conference (2014, October 09)

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See detailDUSP3 Phosphatase Deficiency or Inhibition Limit Platelet Activation and Arterial Thrombosis
Musumeci, Lucia ULg; Kuijpers, Marijke; Gilio, Karen et al

in Circulation (2015), 131(7), 656-68

Background A limitation of current antiplatelet therapies is their inability to separate thrombotic events from bleeding occurrences. Better understanding of the molecular mechanisms leading to platelet ... [more ▼]

Background A limitation of current antiplatelet therapies is their inability to separate thrombotic events from bleeding occurrences. Better understanding of the molecular mechanisms leading to platelet activation is of importance for the development of improved therapies. Recently, protein tyrosine phosphatases (PTPs) have emerged as critical regulators of platelet function. Methods and Results This is the first report implicating the dual-specificity phosphatase 3 (DUSP3) in platelet signaling and thrombosis. This phosphatase is highly expressed in human and mouse platelets. Platelets from DUSP3-deficient mice displayed a selective impairment of aggregation and granule secretion mediated through the collagen receptor glycoprotein VI (GPVI) and the C-type lectin-like receptor 2 (CLEC-2). DUSP3-deficient mice were more resistant to collagen- and epinephrine-induced thromboembolism, compared to wild-type mice, and showed severely impaired thrombus formation upon ferric chloride-induced carotid artery injury. Intriguingly, bleeding times were not altered in DUSP3-deficient mice. At the molecular level, DUSP3 deficiency impaired Syk tyrosine phosphorylation, subsequently reducing phosphorylation of PLCγ2 and calcium fluxes. To investigate DUSP3 function in human platelets, a novel small-molecule inhibitor of DUSP3 was developed. This compound specifically inhibited collagen and CLEC-2-induced human platelet aggregation, thereby phenocopying the effect of DUSP3 deficiency in murine cells. Conclusions DUSP3 plays a selective and essential role in collagen- and CLEC-2-mediated platelet activation and thrombus formation in vivo. Inhibition of DUSP3 may prove therapeutic for arterial thrombosis. This is the first time a PTP, implicated in platelet signaling, has been targeted with a small-molecule drug. [less ▲]

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See detailDUSP3/VHR is a pro-angiogenic atypical dual-specificity phosphatase
Amand, Mathieu ULg; Erpicum, Charlotte ULg; BAJOU, Khalid ULg et al

Poster (2014, January 27)

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See detailDUSP3/VHR is a pro-angiogenic atypical dual-specificity phosphatase
Amand, Mathieu ULg; Erpicum, Charlotte ULg; BAJOU, Khalid ULg et al

in Molecular Cancer (2014)

Background DUSP3 phosphatase, also known as Vaccinia-H1 Related (VHR) phosphatase, encoded by DUSP3/Dusp3 gene, is a relatively small member of the dual-specificity protein phosphatases. In vitro studies ... [more ▼]

Background DUSP3 phosphatase, also known as Vaccinia-H1 Related (VHR) phosphatase, encoded by DUSP3/Dusp3 gene, is a relatively small member of the dual-specificity protein phosphatases. In vitro studies showed that DUSP3 is a negative regulator of ERK and JNK pathways in several cell lines. On the other hand, DUSP3 is implicated in human cancer. It has been alternatively described as having tumor suppressive and oncogenic properties. Thus, the available data suggest that DUSP3 plays complex and contradictory roles in tumorigenesis that could be cell type-dependent. Since most of these studies were performed using recombinant proteins or in cell-transfection based assays, the physiological function of DUSP3 has remained elusive. Results Using immunohistochemistry on human cervical sections, we observed a strong expression of DUSP3 in endothelial cells (EC) suggesting a contribution for this phosphatase to EC functions. DUSP3 downregulation, using RNA interference, in human EC reduced significantly in vitro tube formation on Matrigel and spheroid angiogenic sprouting. However, this defect was not associated with an altered phosphorylation of the documented in vitro DUSP3 substrates, ERK1/2, JNK1/2 and EGFR but was associated with an increased PKC phosphorylation. To investigate the physiological function of DUSP3, we generated Dusp3-deficient mice by homologous recombination. The obtained DUSP3-/- mice were healthy, fertile, with no spontaneous phenotype and no vascular defect. However, DUSP3 deficiency prevented neo-vascularization of transplanted b-FGF containing Matrigel and LLC xenograft tumors as evidenced by hemoglobin (Hb) and FITC-dextran quantifications. Furthermore, we found that DUSP3 is required for b-FGF-induced microvessel outgrowth in the aortic ring assay. Conclusions All together, our data identify DUSP3 as a new important player in angiogenesis. [less ▲]

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See detailDussart Frans
Merenne-Schoumaker, Bernadette ULg

in Nouvelle biographie nationale (2010)

Courte biographie du Prof F. Dussart de l'Université de Liège

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See detailDUst Around NEarby Stars. The survey observational results
Eiroa, C; Marshall, J; Mora, A et al

in Astronomy and Astrophysics (2013), 555

Context. Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system's counterparts are the asteroid and Edgeworth-Kuiper ... [more ▼]

Context. Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system's counterparts are the asteroid and Edgeworth-Kuiper belts. Aims. The DUNES survey aims at detecting extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars, putting in this way the solar system into context. The survey allows us to address some questions related to the prevalence and properties of planetesimal systems. Methods. We used Herschel/PACS to observe a sample of nearby FGK stars. Data at 100 and 160 μm were obtained, complemented in some cases with observations at 70 μm, and at 250, 350 and 500 μm using SPIRE. The observing strategy was to integrate as deep as possible at 100 μm to detect the stellar photosphere. Results. Debris discs have been detected at a fractional luminosity level down to several times that of the Edgeworth-Kuiper belt. The incidence rate of discs around the DUNES stars is increased from a rate of ∼ 12.1% ± 5% before Herschel to ∼ 20.2% ± 2%. A significant fraction (∼ 52%) of the discs are resolved, which represents an enormous step ahead from the previously known resolved discs. Some stars are associated with faint far-IR excesses attributed to a new class of cold discs. Although it cannot be excluded that these excesses are produced by coincidental alignment of background galaxies, statistical arguments suggest that at least some of them are true debris discs. Some discs display peculiar SEDs with spectral indexes in the 70–160 μm range steeper than the Rayleigh-Jeans one. An analysis of the debris disc parameters suggests that a decrease might exist of the mean black body radius from the F-type to the K-type stars. In addition, a weak trend is suggested for a correlation of disc sizes and an anticorrelation of disc temperatures with the stellar age. [less ▲]

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See detailDust exposure exacerbates the expression of ptx3, a recently discovered acute phase protein, in horses’ airways
Ramery, Eve ULg; Bureau, Fabrice ULg; Lekeux, Pierre ULg

Conference (2009)

Heaves is a common cause of recurrent airway obstruction (R.A.O) that occurs in mature horses stabled in a dusty environment. The long pentraxin PTX3 play an important role in the host defence and over ... [more ▼]

Heaves is a common cause of recurrent airway obstruction (R.A.O) that occurs in mature horses stabled in a dusty environment. The long pentraxin PTX3 play an important role in the host defence and over-expression of PTX3 may contribute to airways injury. Therefore, we hypothesised that PTX3 may have relevance in the understanding of the pathogenesis of recurrent airway obstruction (R.A.O). In the present study, we first investigated the equine PTX3 (ePTX3) structure by cloning, sequencing and western-blotting. A 120pb deletion was found in the second exon of ePTX3 in comparison to human PTX3. Moreover, an alternative splicing occurs with complete deletion of the second exon, resulting in two forms of the protein, “spliced” (32 kD) and “full length” (42 kD). The pentraxin domain is very well conserved in the two forms with 94% of amino-acids conserved between equines and humans. These findings could have implications for the comprehension of the function of each domain of the protein. Then, we studied the effects of dust exposure and subsequent R.A.O crisis on ePTX3 expression in the broncho-alveolar lavage fluid (BALF) and the bronchial epithelial cells. PTX3 could be detected in BALF macrophages, neutrophils, eosinophils and bronchial epithelial cells. It was over-expressed in the BALF supernatant from RAO-affected horses in crisis. Dust exposure induced PTX3 in BALF macrophages either in healthy horses or in R.A.O-affected horses. Conversely, PTX3 was strongly over-expressed in the bronchial epithelial cells from R.A.O-affected horses in crisis. Considering epithelial cells as one of the major cell types in the airways, PTX3 produced at this level may play an important role in inflammatory process. Moreover, it suggests that dust-induced expression of PTX3 is differentially regulated in macrophages and bronchial-epithelial cells. A JNK-dependant, NFκB-independent regulatory pathway has been described in lung epithelial cells. A comparable mechanism could be involved in bronchial epithelial cells. If this is confirmed, PTX3 expression in respiratory epithelial cells could be therapeutically targeted. [less ▲]

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See detailDust formation by the colliding wind WC5+O9 binary WR19 at periastron passage
Williams, P. M.; Rauw, Grégor ULg; van der Hucht, K. A.

in Monthly Notices of the Royal Astronomical Society (2009), 395

We present infrared photometry of the episodic dust-making Wolf-Rayet system WR19 (LS3), tracking its fading from a third observed dust formation episode in 2007 and strengthening the view that these ... [more ▼]

We present infrared photometry of the episodic dust-making Wolf-Rayet system WR19 (LS3), tracking its fading from a third observed dust formation episode in 2007 and strengthening the view that these episodes are periodic (P = 10.1 +/- 0.1y). Radial velocities (RVs) of the O9 component observed between 2001 and 2008 show RV variations consistent with WR19 being a spectroscopic binary of high eccentricity (e = 0.8), having periastron passage in 2007.14, shortly before the phase of dust formation. In this respect, WR19 resembles the archetypical episodic dust-making colliding wind binary system WR140. Based on observations collected at the European Southern Observatory, La Silla, Chile, in allocations 67.D-0043, 70.D-0266, 72.D-0070, 73.D-0027, 74.D-0116, 76.D-0029, 78.D-0001, 79.D-0092 and 80.D-0198. E-mail: pmw@roe.ac.uk [less ▲]

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See detailDust from Comet 209P/LINEAR during its 2014 Return: Parent Body of a New Meteor Shower, the May Camelopardalids
Ishiguro, Masateru; Kuroda, Daisuke; Hanayama, Hidekazu et al

in The Astrophysical Journal Letters (2015), 798

We report a new observation of the Jupiter family comet 209P/LINEAR during its 2014 return. The comet is recognized as a dust source of a new meteor shower, the May Camelopardalids. 209P/LINEAR was ... [more ▼]

We report a new observation of the Jupiter family comet 209P/LINEAR during its 2014 return. The comet is recognized as a dust source of a new meteor shower, the May Camelopardalids. 209P/LINEAR was apparently inactive at a heliocentric distance r<SUB>h</SUB> = 1.6 AU and showed weak activity at r<SUB>h</SUB> <= 1.4 AU. We found an active region of <0.001% of the entire nuclear surface during the comet's dormant phase. An edge-on image suggests that particles up to 1 cm in size (with an uncertainty of factor 3-5) were ejected following a differential power-law size distribution with index q = –3.25 ± 0.10. We derived a mass-loss rate of 2-10 kg s<SUP>–1</SUP> during the active phase and a total mass of ≈5 × 10<SUP>7</SUP> kg during the 2014 return. The ejection terminal velocity of millimeter- to centimeter-sized particles was 1-4 m s<SUP>–1</SUP>, which is comparable to the escape velocity from the nucleus (1.4 m s<SUP>–1</SUP>). These results imply that such large meteoric particles marginally escaped from the highly dormant comet nucleus via the gas drag force only within a few months of the perihelion passage. [less ▲]

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See detailDust historical record in ombrotrophic peat: The case study of a NW European bog
Allan, Mohammed ULg; Fagel, Nathalie ULg; Le Roux, Gael et al

Poster (2013, May 16)

Ombrotrophic peatlands are unique environmental archives of natural and anthropogenic atmospheric dust deposition because their surface layers are exclusively fed by atmospheric inputs. Lead (Pb) isotopes ... [more ▼]

Ombrotrophic peatlands are unique environmental archives of natural and anthropogenic atmospheric dust deposition because their surface layers are exclusively fed by atmospheric inputs. Lead (Pb) isotopes have been often used to evidence any anthropogenic influence in peat, but they only record trace metal pollution. Another radiogenic isotope, the Neodymium (Nd), could be also use to discriminate the sources of dust in peat bogs. Dust fluxes were investigated over the last 2500 years in the Misten peat bog in Eastern Belgium. Our aims were to use Nd isotope signature to decipher between local and distal dust supplies, the Pb isotopes to trace the antropogenic influences. To address these aims we analyzed REE and lithogenic element analyses, as well as the Nd and Pb isotopes, using HR-ICP-MS and MC-ICP-MS, respectively in peat layers dated by 210Pb and 14C. Changes in REE concentration variations in peat samples are correlated with Ti, Al, and Zr that are lithogenic conservative elements, suggesting that REE are immobile in the studied peat bogs and can be used as tracers of dust deposition. Dust fluxes show pronounced increase at BC300, AD600, 1000AD, 1200AD and from 1700AD, recording either influence of human activities (regional erosion due to forest clearing and soil cultivation activities) or local and regional climate changes. Lead enrichments reveal strong human impact over the last 300 years. Lead isotope signatures are consistent with local and regional contamination by coal combustion and smelting activities. Neodymium isotopes allow to identify three periods characterised by dominant-distal sources (at 320AD, 1000 AD and 1700AD). Those periods are consistent with local wetter intervals as indicated by lower humification degree. Local erosion prevails durier drier (higher humification) intervals (-100AD, 600AD). On a global scale more distal supplies are driven during colder periods, in particular Oort and Maunder minima, confirming the hypothesis that cold climate conditions favor distal supplies. Combining geochemical elementary content and isotope data in ombrotrophic peat allows to decipher between dust flux changes related to human and climate forcing. [less ▲]

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See detailDust in LBV-type Nebulae
Hutsemekers, Damien ULg

in Luminous Blue Variables: Massive Stars in Transition. ASPC 120 (1997)

Some systematic properties of dust in LBV-type nebulae are reviewed on the basis of the far-infrared thermal emission measured by the IRAS satellite, and the scattering of visible stellar light.

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See detailDust in the inner regions of debris disks around A stars
Akeson, R. L.; Ciardi, D. R.; Millan-Gabet, R. et al

in Astrophysical Journal (2009), 691

We present infrared interferometric observations of the inner regions of two A-star debris disks, beta Leo and zeta Lep, using the FLUOR instrument at the CHARA interferometer on both short (30 m) and ... [more ▼]

We present infrared interferometric observations of the inner regions of two A-star debris disks, beta Leo and zeta Lep, using the FLUOR instrument at the CHARA interferometer on both short (30 m) and long (> 200 m) baselines. For the target stars, the short-baseline visibilities are lower than expected for the stellar photosphere alone, while those of a check star, delta Leo, are not. We interpret this visibility offset of a few percent as a near-infrared (NIR) excess arising from dust grains which, due to the instrumental field of view, must be located within several AU of the central star. For beta Leo, the NIR excess-producing grains are spatially distinct from the dust which produces the previously known mid-infrared (MIR) excess. For zeta Lep, the NIR excess may be spatially associated with the MIR excess-producing material. We present simple geometric models which are consistent with the NIR and MIR excesses and show that for both objects, the NIR-producing material is most consistent with a thin ring of dust near the sublimation radius, with typical grain sizes smaller than the nominal radiation pressure blowout radius. Finally, we discuss possible origins of the NIR-emitting dust in the context of debris disk evolution models. [less ▲]

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See detailDust in the Wind and Public Health: Example from Mauritania.
Ozer, Pierre ULg

in Ozer, André; Swinne, Danièle (Eds.) Desertification: Migration, Health, Remediation and Local Governance. (2008)

The Sahara largely contributes to the global injection of mineral dust into the northern hemisphere. Since the onset of the drought in the Sahel and the environmental degradation in the arid and semi-arid ... [more ▼]

The Sahara largely contributes to the global injection of mineral dust into the northern hemisphere. Since the onset of the drought in the Sahel and the environmental degradation in the arid and semi-arid belts surrounding the Sahara, dust storms frequency and intensity has dramatically increased. It is now irrefutable that air pollution caused by large amounts of respiratory particulates or Particulate Matter less than 10 µm in aerodynamic diameter (PM10) has numerous undesired consequences on human health. Air quality degradation far away from the African continent in the US and in Europe caused by high concentration of African dust is seen as a major health threat although most of these countries are very distant from the Sahara. Surprisingly, no estimates of PM10 levels near the Saharan dust source are available. Based on horizontal visibility observations which are reduced by the presence of dust in the atmosphere, PM10 levels are estimated at the station of Nouakchott, Mauritania by using relations found in the literature. It appears that excessive concentrations of particles are very important both in magnitude and frequency as the 24-hour PM10 thresholds established by the US EPA National Ambient Air Quality Standards and the EU Limits Values for Air Quality were systematically exceeded. The average yearly concentration is far above air quality standards. These very high particulate levels are likely to represent an important public health threat and should be considered as a major environmental risk. We present here a first comparison between monthly respiratory diseases data and PM10 concentrations due to dust storms. [less ▲]

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See detailDust variability and land degradation in the Sahel
Ozer, Pierre ULg

in Belgeo (2002), 2002(2), 195-209

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See detailDust-acoustic modes in plasmas with dust distributions and charge fluctuations
Verheest, F.; Jacobs, G.; Cattaert, Tom ULg

in New Journal of Physics (2003), 5

Charge fluctuations in dusty plasmas are discussed starting from charge, mass, momentum and current equations for the combined dusty plasma. This allows a generic description of low-frequency waves in ... [more ▼]

Charge fluctuations in dusty plasmas are discussed starting from charge, mass, momentum and current equations for the combined dusty plasma. This allows a generic description of low-frequency waves in plasmas with dust distributions, and leads to the damping and other modifications of the dust-acoustic and related modes, like generalized dust-Coulomb modes. [less ▲]

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See detailA dustfall event in November 1996 in Genoa, Italy.
Ozer, Pierre ULg; Erpicum, Michel ULg; Cortemiglia, Gian Camillo et al

in Weather (1998), 53(5), 140-145

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See detailA dusty nebula around the luminous blue variable candidate HD 168625
Hutsemekers, Damien ULg; van Drom, E.; Gosset, Eric ULg et al

in Astronomy and Astrophysics (1994), 290

On the basis of narrow-band visible and near-infrared imagery as well as high-resolution spectroscopy, we report the discovery of a new LBV-type nebula around the B supergiant HD 168625. We find that it ... [more ▼]

On the basis of narrow-band visible and near-infrared imagery as well as high-resolution spectroscopy, we report the discovery of a new LBV-type nebula around the B supergiant HD 168625. We find that it essentially consists of a dusty expanding shell from which seems to emerge a bipolar emission nebula, the whole embedded in a reflection nebulosity. The inner shell is stratified: the continuum emission arises beyond the ionized gas, and is possibly due to scattering of stellar light by large dust grains or to non-equilibrium dust emission. The unexpected presence of unidentified infrared emission bands (UIRs) in the spectrum of this object is also discussed. We finally report the non-detection of a comparable nebula around the nearby LBV HD 168607. [less ▲]

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