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See detailStratospheric HCl increasing again, caused by dynamic variability, driven by increased tropopsheric wave activity
Notholt, J; Mahieu, Emmanuel ULg; Pfloeger, F et al

Conference (2015, September 22)

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See detailIntroduction au droit
Grandjean, Geoffrey ULg

Learning material (2015)

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Peer Reviewed
See detailMultimodality imaging assessment of the deleterious role of the intraluminal thrombus on the growth of abdominal aortic aneurysm in a rat model
NCHIMI LONGANG, Alain ULg; Courtois, Audrey ULg; EL HACHEMI, Mounia ULg et al

in European Radiology (2015), online

Objectives To evaluate imaging changes occurring in a rat model of elastase-induced abdominal aortic aneurysm (AAA), with emphasis on the intraluminal thrombus (ILT) occurrence. Methods The post-induction ... [more ▼]

Objectives To evaluate imaging changes occurring in a rat model of elastase-induced abdominal aortic aneurysm (AAA), with emphasis on the intraluminal thrombus (ILT) occurrence. Methods The post-induction growth of the AAA diameter was characterized using ultrasound in 22 rats. ILT was reported on 13 rats that underwent 14 magnetic resonance imaging (MRI) 2-18 days post-surgery, and on 10 rats that underwent 18 fluoro-deoxyglucose (FDG) positron emission tomography (PET)/microcomputed tomography examinations 2-27 days post-surgery. Logistic regressions were used to establish the evolution with time of AAA length, diameter, ILT thickness, volume, stratification, MRI and FDG PET signalling properties, and histological assessment of inflammatory infiltrates. Results All of the following significantly increased with time post-induction (p < 0.001): AAA length, AAA diameter, ILT maximal thickness, ILT volume, ILT iron content and related MRI signalling changes, quantitative uptake on FDG PET, and the magnitude of inflammatory infiltrates on histology. However, the aneurysm growth peak followed occurrence of ILT approximately 6 days after elastase infusion. Conclusion Our model emphasizes that occurrence of ILT precedes AAA peak growth. Aneurysm growth is associated with increasing levels of iron, signalling properties changes in both MRI and FDG PET, relating to its biological activities. [less ▲]

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See detailCurrent status of fasciolosis in Vietnam: an update and perspectives
Bui Thi, Dung ULg; Pham, Ngoc Doanh; Saegerman, Claude ULg et al

in Journal of Helminthology (2015)

Vietnam is recognized as endemic for fasciolosis. However, most of the available publications have not been published in international journals. This review is based on national and international ... [more ▼]

Vietnam is recognized as endemic for fasciolosis. However, most of the available publications have not been published in international journals. This review is based on national and international Vietnamese publications and highlights the current status of fasciolosis in Vietnam. It also provides some information available in neighboring countries. Updated data on responsible species, distribution, transmission and control aspects, are summarized. The Central region of Vietnam is reported as being highly endemic for fasciolosis with a high number of human patients (more than 20.000 in 2011). Fasciola gigantica is reported as the main species in Vietnam. However, hybrids between F. gigantica and F. hepatica were identified. Both human and animals are infected by the ingestion of raw vegetables and possibly contaminated drinking water. Three lymnaeid snail species (Austropeplea viridis, Radix auricularia, Radix rubiginosa) may act as intermediate host of Fasciola spp. However due to the likely misidentification of snail species and cercariae during the previous decade the critical analysis of published data is difficult. A better understanding of transmission aspects of fasciolosis would allow the implementation of preventive measures of this important neglected zoonotic disease. [less ▲]

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Peer Reviewed
See detailInfluence of the macromolecular surfactant features and reactivity on morphology and surface properties of emulsion-templated porous polymers
Mathieu, Kevin ULg; Jérôme, Christine ULg; Debuigne, Antoine ULg

in Macromolecules (2015), 48(18), 6489-6498

This work investigates key parameters of a straightfor- ward macromolecular surfactant-assisted functionalization strategy of porous polymers produced by high internal phase emulsion (HIPE) polymerization ... [more ▼]

This work investigates key parameters of a straightfor- ward macromolecular surfactant-assisted functionalization strategy of porous polymers produced by high internal phase emulsion (HIPE) polymerization. For that purpose, a series of well-defined amphiphilic poly(ethylene oxide)-b-poly(styrene) (PEO-b-PS) copolymers with various compositions and molar masses were synthesized by radical addition−fragmentation chain transfer (RAFT) polymerization and used as macromolecular surfactants for the emulsion-templated polymerization of styrene/divinylbenzene (S/DVB). The morphology of the resulting foams, referred to as polyHIPEs, was found dependent on the PS block length and concentration of the block copolymer surfactant in the emulsion. Moreover, we determined the lowest PS block length required for preserving the anchoring of the copolymer at the surface by physical entanglement within the S/DVB cross-linked matrix leading to a PEO-coated porous material. The functionalization of the porous monoliths with PEO was evidenced by sessile drop shape analyses and water uptake experiments. The chemical anchoring of the PEO-b-PS at the surface of polyHIPEs was also explored by interfacial initiation of the HIPE polymerization from a PEO-b-PS-RAFT macroinitiator leading to porous structures with permanent PEO coatings. In this case, copolymerizing DVB with acrylate instead of styrene improved the interconnectivity of the porous monoliths. [less ▲]

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See detail"Il figlio di Bakunìn". Anarchico innamorato della vita e delle donne.
Curreri, Luciano ULg

Article for general public (2015)

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See detailAir-sea ice gases exchange: update of recent findings, outcomes from sea ice models, caveats and open questions
Delille, Bruno ULg; Zhou, Jiayun; Kotovitch, Marie ULg et al

Conference (2015, September 21)

There are growing evidences that sea ice exchanges climate gases with the atmosphere. We will rapidly present a state of the art of current large scale assessment of spring and summer uptake of ... [more ▼]

There are growing evidences that sea ice exchanges climate gases with the atmosphere. We will rapidly present a state of the art of current large scale assessment of spring and summer uptake of atmospheric CO2. We will challenge these assessments with 1) new evidence of significant winter CO2 release for winter experiments 2) new finding of the role of bubbles formation and transport within sea ice and 3) impurities expulsion derived from combined artificial ice experiment and modelling. Finally, comparison of air-ice fluxes derived from automated chamber and micrometeorological method and, mechanistic and box models show significant discrepancies that suggest that the contribution of sea ice to the air-ocean fluxes of CO2 remain an open question. We will also highlight that sea ice contribute to the fluxes of other gases as CH4 ,N2O and DMS [less ▲]

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See detailThe role of feedback in maintaining robustness and modulation across scales: Insights from cellular and network neurophysiology
Dethier, Julie ULg

Doctoral thesis (2015)

The brain is a complex system made of many components acting at very dif- ferent resolution levels, from the microsecond and nanometer scales with ion channels to hours and brain-wide scale with proteins ... [more ▼]

The brain is a complex system made of many components acting at very dif- ferent resolution levels, from the microsecond and nanometer scales with ion channels to hours and brain-wide scale with proteins. The brain dynamics and functions emerge from the interactions between these resolution levels. Math- ematical modeling is a powerful ally to uncover some of the brain organizing principles and mechanisms. From this perspective, the question of which cel- lular details must be retained at the network level is largely open. Motifs simplify systems by approximating the wiring diagram and by taking advantage of the timescale separation between processes. Yet, motifs study each resolution level separately and neglect couplings between levels. This approach falls short of system-level questions and multiresolution intrinsic properties. The present dissertation aims at narrowing the gap by looking at the inter- play between resolution levels. We propose to extract essential elements, in the form of feedback loops, to be maintained from one resolution to the next in the hope of a better understanding of brain functions and diseases. The focus is on the spatiotemporal upscaling from the neuron to the network level and, in particular, on the maintenance of modulation and robustness properties across scales. This approach is used in a two-neuron network and is extended to a prospective multiresolution excitability framework. The main contributions of this dissertation are the following. We identify the key role of a cellular feedback loop for network oscillation robustness and modulation. Rhythms are crucial in the brain functioning but much awaits to be understood regarding their control, regulation, and function. In a mutually-inhibitory network, we isolate an essential cellular property—a positive feedback loop in the slow timescale—to be retained at the network level to ensure modulation and robustness of network oscillations. We highlight the peculiar role that a cellular feedback loop can play for the regulation of network switches. We identify that a cellular positive feedback loop brings localization properties, both temporally and spatially, to network oscillations. The emerging picture suggests a basal ganglia network model valid both in healthy movement-related oscillations and in parkinsonian conditions. Multiresolution excitability emerges due to localization properties of ex- citable systems: different excitability resolution windows can be superposed and interact, generating multiresolution systems. In each window, the system is characterized via its transfer properties and input-output behavior. Signal processing properties appear in these multiresolution systems and endow mul- tiresolution objects with gating and multiplex signaling capabilities. In conclusion, the present dissertation provides novel insights on the impor- tance of the interplay between cellular and network levels. This multiresolution motif perspective is thought to be general and not specific to neuroscience. Fi- nally, exploiting the concept in multiresolution technologies is suggested. [less ▲]

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See detailOPSE metrology system onboard of the PROBA3 mission of ESA
Loreggia, D.; Bemporad, A.; Capobianco, G. et al

in Proc. SPIE Volume 9604 Solar Physics and Space Weather Instrumentation VI (2015, September 21)

In recent years, ESA has assessed several mission involving formation flying (FF). The great interest in this topics is mainly driven by the need for moving from ground to space the location of next ... [more ▼]

In recent years, ESA has assessed several mission involving formation flying (FF). The great interest in this topics is mainly driven by the need for moving from ground to space the location of next generation astronomical telescopes overcoming most of the critical problems, as example the construction of huge baselines for interferometry. In this scenario, metrology systems play a critical role. PROBA3 is an ESA technology mission devoted to in-orbit demonstration of the FF technique, with two satellites, an occulter and a main satellite housing a coronagraph named ASPIICS, kept at an average inter-distance by about 144m, with micron scale accuracy. The guiding proposal is to test several metrology solution for spacecraft alignment, with the important scientific return of having observation of Corona at never reached before angular field. The Shadow Position Sensors (SPS), and the Optical Position Emitters Sensors (OPSE) are two of the systems used for FF fine tracking. The SPS are finalized to monitor the position of the two spacecraft with respect to the Sun and are discussed in dedicated papers presented in this conference. The OPSE will monitor the relative position of the two satellites and consists of 3 emitters positioned on the rear surface of the occulter, that will be observed by the coronagraph itself. By following the evolution of the emitters images at the focal plane the alignment of the two spacecrafts is retrieved via dedicated centroiding algoritm. We present an overview of the OPSE system and of the centroiding approach. [less ▲]

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See detailThe Shadow Positioning Sensors (SPS) for formation flying metrology on-board the ESA-PROBA3 mission
Bemporad, A.; Baccani, C.; Capobianco, G. et al

in Proc. SPIE Volume 9604 Solar Physics and Space Weather Instrumentation VI (2015, September 21)

PROBA3 is an ESA technology mission devoted to in-orbit demonstration of the formation flight (FF) technique, with two satellites kept at an average inter-distance by about 144 m. The ASPIICS instrument ... [more ▼]

PROBA3 is an ESA technology mission devoted to in-orbit demonstration of the formation flight (FF) technique, with two satellites kept at an average inter-distance by about 144 m. The ASPIICS instrument on-board PROBA3 will be the first ever space-based coronagraph working on one satellite and having the external occulter located on the second satellite, thus allowing observations of the inner solar corona with unprecedented reduction of stray light. During the observational periods, the FF configuration will be maintained with very high precision and two different techniques will be implemented: the use of Shadow Positioning Sensors (SPS) located on the Coronagraph Spacecraft (diodes measuring the penumbral light intensity on the entrance pupil plane) and the use of Occulter Position Sensor LEDs (OPSE) located on the back side of the Occulter Spacecraft. This paper will review the main instrumental requirements on the SPS needed to determine the 3-dimensional relative positioning of the two PROBA3 satellites with the high precision and frequency. [less ▲]

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See detailFormation flying metrology for the ESA-PROBA3 mission: the Shadow Position Sensors (SPS) silicon photomultipliers (SiPMs) readout electronics
Focardi, M.; Bemporad, A.; Buckley, S. et al

in Proc. SPIE Volume 9604 Solar Physics and Space Weather Instrumentation VI (2015, September 21)

The European Space Agency (ESA) is planning to launch in 2018 the PROBA3 Mission, designed to demonstrate the inorbit formation flying (FF) attitude capability of its two satellites and to observe the ... [more ▼]

The European Space Agency (ESA) is planning to launch in 2018 the PROBA3 Mission, designed to demonstrate the inorbit formation flying (FF) attitude capability of its two satellites and to observe the inner part of the visible solar corona as the main scientific objective. The solar corona will be observed thanks to the presence on the first satellite, facing the Sun, of an external occulter producing an artificial eclipse of the Sun disk. The second satellite will carry on the coronagraph telescope and the digital camera system in order to perform imaging of the inner part of the corona in visible polarized light, from 1.08 Rsun up to about 3 Rsun. One of the main metrological subsystems used to control and to maintain the relative (i.e. between the two satellites) and absolute (i.e. with respect to the Sun) FF attitude is the Shadow Position Sensor (SPS) assembly. It is composed of eight micro arrays of silicon photomultipliers (SiPMs) able to measure with the required sensitivity and dynamic range the penumbral light intensity on the Coronagraph entrance pupil. In the following of the present paper we describe the overall SPS subsystem and its readout electronics with respect to the capability to satisfy the mission requirements, from the light conversion process on board the silicon-based SPS devices up to the digital signal readout and sampling. [less ▲]

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See detailDesign and modelisation of ASPIICS optics
Galy, Camille ULg; Fineschi, S.; Galano, D. et al

in Proc. SPIE Volume 9604 Solar Physics and Space Weather Instrumentation VI (2015, September 21)

In the framework of development of ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun), the Centre Spatial de Liege is responsible of the optical design ... [more ▼]

In the framework of development of ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun), the Centre Spatial de Liege is responsible of the optical design of the coronagraph and the optics will be manufactured by TOPTEC. The particularity of this coronagraph is to have an external occulter located 150 m ahead of the first imaging lens. This external occulter is re-imaged on an internal occulter which function is - as in a classical externally occulted Lyot coronagraph - to block the sun light diffracted by the external occulter and to reduce the straylight on the detector. The selection of this configuration is driven by the requirement to observe the corona as close as possible to the solar limb (i.e. 1 RSun) without imaging the limb itself. A requirement of 1.08 RSun is specified at optical design level to grant 1.2 Rsun at instrument level. The coronograph instrument is designed to have a field of view of 1.6° x 1.6° with a resolution of less than 6 arcsec. Its performances are limited by diffraction in a 530 – 590 nm wavelength range. This paper presents the optical design and demonstrates that by design the requirements are fulfilled within the misalignment, manufacturing and thermo-elastic error contributions. [less ▲]

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See detailSignificance of the occulter diffraction for the PROBA3/ASPIICS formation flight metrology
Landini, F.; Bemporad, A.; Focardi, M. et al

in Proc. SPIE Volume 9604 Solar Physics and Space Weather Instrumentation VI (2015, September 21)

PROBA-3/ASPIICS is a formation Flying coronagraph selected by ESA and currently in its C/D phase. It is constituted by two spacecrafts (OSC, Occulter SpaceCraft, carrying the occulter, diameter 142 cm ... [more ▼]

PROBA-3/ASPIICS is a formation Flying coronagraph selected by ESA and currently in its C/D phase. It is constituted by two spacecrafts (OSC, Occulter SpaceCraft, carrying the occulter, diameter 142 cm, and CSC, Coronagraph SpaceCraft, with the telescope) separated by ~144 m, kept in strict alignment by means of an active custom system. The alignment active system most critical components are the Shadow Positioning Sensors (SPS), a series of Si-PM (Silicon Photomultiplier) measuring the penumbra generated by the occulter. The arrangement of the SPSs around the telescope entrance aperture is defined as a trade-off between mechanical constraints and maximum sensitivity to misalignments. The signal detected by the SPSs can be approximately simulated with a geometrical analysis based on the variation of the penumbra generated by the external occulter. The stray light generated by the diffraction from the external occulter may affect the SPSs signal. It is mandatory to carefully evaluate its level in order to refine the active alignment adjustment algorithm. This work is dedicated to the description of the preliminary investigation performed in order to evaluate the impact of the diffraction on the SPSs signal. [less ▲]

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See detailDesign status of ASPIICS, an externally occulted coronagraph for PROBA-3
Renotte, Etienne ULg; Alia, A.; Bemporad, A. et al

in Proc. SPIE Volume 9604 Solar Physics and Space Weather Instrumentation VI (2015, September 21)

The “sonic region” of the Sun corona remains extremely difficult to observe with spatial resolution and sensitivity sufficient to understand the fine scale phenomena that govern the quiescent solar corona ... [more ▼]

The “sonic region” of the Sun corona remains extremely difficult to observe with spatial resolution and sensitivity sufficient to understand the fine scale phenomena that govern the quiescent solar corona, as well as phenomena that lead to coronal mass ejections (CMEs), which influence space weather. Improvement on this front requires eclipse-like conditions over long observation times. The space-borne coronagraphs flown so far provided a continuous coverage of the external parts of the corona but their over-occulting system did not permit to analyse the part of the white-light corona where the main coronal mass is concentrated. The proposed PROBA-3 Coronagraph System, also known as ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun), with its novel design, will be the first space coronagraph to cover the range of radial distances between ~1.15 and 3 solar radii where the magnetic field plays a crucial role in the coronal dynamics, thus providing continuous observational conditions very close to those during a total solar eclipse. PROBA-3 is first a mission devoted to the in-orbit demonstration of precise formation flying techniques and technologies for future European missions, which will fly ASPIICS as primary payload. The instrument is distributed over two satellites flying in formation (approx. 150m apart) to form a giant coronagraph capable of producing a nearly perfect eclipse allowing observing the sun corona closer to the rim than ever before. The coronagraph instrument is developed by a large European consortium including about 20 partners from 7 countries under the auspices of the European Space Agency. This paper is reviewing the recent improvements and design updates of the ASPIICS instrument as it is stepping into the detailed design phase. [less ▲]

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See detailCeci n’est pas un conseil !
Choffray, Jean-Marie ULg

E-print/Working paper (2015)

La « Grande Récession de 2008 » a un mérite. Un seul ! Elle a rendu public le fait que personne ne savait exactement ce qui s’était passé, ni ce qui se passait. Pourquoi une telle crise de confiance avait ... [more ▼]

La « Grande Récession de 2008 » a un mérite. Un seul ! Elle a rendu public le fait que personne ne savait exactement ce qui s’était passé, ni ce qui se passait. Pourquoi une telle crise de confiance avait-elle vu le jour ? Quelles en seraient les conséquences ? Toutes et tous se sont trompés, y compris les meilleurs. Même celles et ceux qui étaient convaincus d’avoir raison ! Plus que jamais, l’incertitude, la saine et souveraine incertitude, garantit la liberté de l’investisseur... et du professeur ! [less ▲]

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See detailArabie saoudite et Etats-Unis: un divorce annoncé
Hermans, Michel ULg; Ernst, Damien ULg

Article for general public (2015)

Detailed reference viewed: 121 (11 ULg)
See detailPathways of recurrent high-grade squamous intraepithelial lesions of the cervix
Herfs, Michael ULg

Conference (2015, September 20)

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See detailMarkets flash graphs
Choffray, Jean-Marie ULg

E-print/Working paper (2015)

A graph is worth a hundred words... A good graph may suggest some new heuristics. And…, a series of excellent graphs may provide the backbone of a theory! The goal of this paper is to share a set of ... [more ▼]

A graph is worth a hundred words... A good graph may suggest some new heuristics. And…, a series of excellent graphs may provide the backbone of a theory! The goal of this paper is to share a set of graphs from multiple sources that offer as many flashes on current and past market conditions. Inevitably, these graphs reflect my own biases and questionings. They are not meant to induce any action aside, maybe, from their integration in a personal Information System. The Great Recession of 2008, whose consequences are still unfolding, has been for each of us a powerful invitation to modesty. We live in a world where improbable, unthinkable and impossible events happen every day... More than ever, it’s time to sit down, shut up, watch out, build graphs, and think… hard! [less ▲]

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See detailLa consultation pour troubles du comportement à l'adolescence : importance du timing pubertaire
Glowacz, Fabienne ULg

Scientific conference (2015, September 19)

Detailed reference viewed: 13 (0 ULg)