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See detailPreliminary results for a hydrogen maser cavity in the TE111 mode
Van Der Beken, Emeline ULg; Léonard, Daniel; Counet, Arnaud et al

Poster (2015, April 13)

An analysis of a hydrogen maser working with an unusual TE111 mode is presented. Different simulations have been carried out and are compared with preliminary results obtained for such a maser. In ... [more ▼]

An analysis of a hydrogen maser working with an unusual TE111 mode is presented. Different simulations have been carried out and are compared with preliminary results obtained for such a maser. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design hydrogen masers with significant reduced dimensions which represents a huge benefit for space applications and in particular for the global positioning system. [less ▲]

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See detailA short dive into the complexity of Jupiter’s aurorae - invited
Bonfond, Bertrand ULg

Conference (2015, April 13)

Aurorae are the atmospheric signatures of energetic processes taking place far in the magnetosphere. One of the most important results brought by high resolution imaging of the UV aurorae at Jupiter is ... [more ▼]

Aurorae are the atmospheric signatures of energetic processes taking place far in the magnetosphere. One of the most important results brought by high resolution imaging of the UV aurorae at Jupiter is the realization that there isn’t such a thing as «the aurora» at Jupiter; as these light emissions appear to arise from a variety of processes. Some are related to the interaction of the magnetospheric plasma with the moons (the satellite footprints). Others are linked with the radial motion of flux tubes through centrifugal instabilities (the injection auroral signatures). Some diffuse emissions are connected with wave-particle interaction (the equatorward diffuse emissions). Another feature is associated with the magnetosphere-ionosphere coupling (the main emission/oval). Some auroral spots are related to internally driven reconnection (the polar dawn spots). Finally, the polar-most emissions remain to be understood and this list is still incomplete. In order to illustrate the discrepancies between these various features, I will show a set of recent results derived from the analysis of Hubble Space Telescope observations. For example, I will compare the vertical profile of satellite footprints and the main emissions, and show that the energy population of the precipitating particles varies from feature to feature. Moreover, even within a single feature, spatial variations do exist. As an example, I will characterize the dawn-dusk brightness discrepancy of the main emissions and discuss its implication regarding the magnetospheric currents. And finally, the dynamics of the features also helps differentiating one type of aurora from another. This will be shown through the description of the morphological evolution of the transient flares in the polar region. [less ▲]

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See detailUrban Greening Processes in Old Industrial Cities in Belgium: Factors of Success in Restoring Quality of Life and Combatting Environmental Inequalities
Lejeune, Zoé ULg

Conference (2015, April 11)

Environmental justice/inequality (EJ/I) movements, first in the US, then in many other countries have sought to shed light on the unequal environmental situations burdened by poor populations and ethnic ... [more ▼]

Environmental justice/inequality (EJ/I) movements, first in the US, then in many other countries have sought to shed light on the unequal environmental situations burdened by poor populations and ethnic minorities, and to challenge public policies and their unfair impact on those groups. In continental Europe and more specifically in Belgium, EJ activism has not emerged as a specific frame for environmental and urban contention. Locating this research at the interface of environmental inequality and urban environmental planning, we present findings from qualitative analysis gathered through interviews with local stakeholders be they elected officials, local officers, non-profit, or residents (n=30); our purpose is to ask how social movements as well as public authorities and ordinary citizens manage to reverse urban decline in old industrial cities in Belgium through environmental channels. These cities are characterized by environmental degradation and inequalities: atmospheric and soil pollution, brownfields, and high rates of unemployment, poverty, and social exclusion. We are interested in urban environmental processes, and explore the following question: what are the factors of success in restoring quality of life and wellbeing in two Belgian cities, with different mobilization profiles – one is successful, the other not – putting into perspective the determinants of successful renewal processes? We are particularly interested in understanding how environmental (inequality) issues are framed and handled politically at the local scale within those cities? The underlying goal consists of defining and formalizing new spaces and configurations of multilevel regulation between stakeholders, acting scale to revitalize their environment and their city or neighborhood, and to improve current urban policies in order to reduce environmental inequalities. Key findings are divided into five main explanatory categories: political opportunity structure; non-profit sector organization; citizens’ characteristics and collective action framework; bureaucratic reform; and symbolic action. [less ▲]

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See detailCibo e Islam.
Mescoli, Elsa ULg

Conference given outside the academic context (2015)

Séminaire organisé dans le cadre d'un cours de formation pour professionnels. Thématique: le rapport à la nourriture dans la religion islamique (interdictions, indications, rituels etc.).

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See detailWhat is the professional profile of patients in phoniatrics?
Remacle, Angélique ULg; Petitfils, Cloé; LEJEUNE, LIONEL ULg et al

Conference (2015, April 10)

Objective. Research has paid increased attention to occupational voice disorders. This study describes the occupational status of patients examined in the Department of Otorhinolaryngology at Liège ... [more ▼]

Objective. Research has paid increased attention to occupational voice disorders. This study describes the occupational status of patients examined in the Department of Otorhinolaryngology at Liège University Hospital (Belgium) from 2009 to 2013. Study design. Retrospective study. Methods. The sex, age, diagnosis and occupational status were identified for 1,079 patients who were examined for a voice problem (754 women and 325 men; ages 4 to 93). The diagnosis was established using videolaryngostroboscopy. For patients who were employed, we identified (1) the numerically most frequent professionals, and (2) the professionals most at risk of consulting for their voice, based on the distribution of these professions among all workers living in French-speaking Belgium. Results. 11% of patients were unemployed, 15% were students, 20% were retired, and 54% were workers. In decreasing order of frequency, the most commonly seen professionals were teachers, office workers, artists (singers, actors, and musicians), storekeepers and marketing representatives, managers, domestic workers, and laborers. Regarding their distribution in the working population, the workers at greatest risk of consulting were artists, music teachers, counselors, sports coaches, psychologists, switchboard operators, journalists, and teachers. Nodules are the most common pathologies, encountered in 16.8% of the workers and 42.8% of the students who consulted the Department of Otorhinolaryngology for dysphonia. Conclusion. Prevention is needed both for the professions that seek medical help in the largest numbers (teachers) and for those that are at highest risk of consulting (artistic professions). In addition, teachers must be informed of the need to seek help as soon as voice problems appear. Level of evidence: 2b [less ▲]

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See detailChallenges of Sustainable and Commercial Aquaponics
Goddek, Simon; Delaide, Boris ULg; Mankasingh, Utra et al

in Sustainability (2015), 7

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See detailLecteurs truqués : sur la fabrique médiatique du lectorat au XIXe siècle
Stienon, Valérie ULg

Scientific conference (2015, April 10)

Les voix du lecteur en journal semblent autant fabriquées que relayées. Faux profils, rubriques convenues, individualisation artificielle d’une catégorie de destinataires, confusion entre les récepteurs ... [more ▼]

Les voix du lecteur en journal semblent autant fabriquées que relayées. Faux profils, rubriques convenues, individualisation artificielle d’une catégorie de destinataires, confusion entre les récepteurs et l’équipe de rédaction : ce sont là des cas fréquents. C’est à ces non-coïncidences entre l’expression d’un discours présenté comme généré de l'extérieur du journal, par sa réception, et la ressaisie de ce discours dans le dispositif et la poétique du périodique de presse que sont consacrées les observations mises en évidence dans cette communication. [less ▲]

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See detailMéthode ethnographique et science sociocriminologique. Le cas des groupements de jeunes.
Collin, Jonathan ULg

Conference given outside the academic context (2015)

ARGUMENT : Comment allier objet d'intérêt criminologique et méthodes de recherche ? Comment construire une méthode pertinente pour rendre compte, par exemple, de la réalité des groupes de jeunes, en ce ... [more ▼]

ARGUMENT : Comment allier objet d'intérêt criminologique et méthodes de recherche ? Comment construire une méthode pertinente pour rendre compte, par exemple, de la réalité des groupes de jeunes, en ce compris ce que certains praticiens et chercheurs nomment "les bandes" ? La réponse se trouve peut-être dans la méthode ethnographique, dont nous savons qu'elle fut utilisée par les sociologues dits de l'Ecole de Chicago et qu'elle est encore la base méthodologique des recherches en anthropologie et de certaines études sociologiques. Pourrait-on alors parler "d'ethnocriminologie", dans le sens où l'on étudierait un phénomène d'intérêt criminologique à travers la méthode ethnographique ? Plus largement, quelle place la criminologie fait-elle à l'anthropologie et à l'ethnographie ? [less ▲]

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See detailOptimal Enforcement of Competition Policy: The Commitments Procedure under Uncertainty
Gautier, Axel ULg

Scientific conference (2015, April 09)

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See detailLa génétique de l'acromégalie
Beckers, Albert ULg

Scientific conference (2015, April 09)

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See detailImproved spectral fitting of nitrogen dioxide from OMI in the 405-465 nm window
van Geffen, J H G M; Boersma, K F; Van Roozendael, M et al

in Atmospheric Measurement Techniques (2015), 8

An improved nitrogen dioxide (NO2) slant column density retrieval for the Ozone Monitoring Instrument (OMI) in the 405–465 nm spectral region is presented. Since the launch of OMI on board NASA’s EOS-Aura ... [more ▼]

An improved nitrogen dioxide (NO2) slant column density retrieval for the Ozone Monitoring Instrument (OMI) in the 405–465 nm spectral region is presented. Since the launch of OMI on board NASA’s EOS-Aura satellite in 2004, differential optical absorption spectroscopy (DOAS) retrievals of NO2 slant column densities have been the starting point for the KNMI DOMINO and NASA SP NO2 vertical column data as well as the OMI NO2 data of some other institutes. However, recent intercomparisons between NO2 retrievals from OMI and other UV/Vis and limb spectrometers, as well as ground-based measurements, suggest that OMI stratospheric NO2 is biased high. This study revises and, for the first time, fully documents the OMI NO2 retrieval in detail. The representation of the OMI slit function to convolve high-resolution reference spectra onto the relevant spectral grid is improved. The window used for the wavelength calibration is optimised, leading to much-reduced fitting errors. Ozone and water vapour spectra used in the fit are updated, reflecting the recently improved knowledge of their absorption cross section in the literature. The improved spectral fit also accounts for absorption by the O2–O2 collision complex and by liquid water over clearwater areas. The main changes in the improved spectral fitting result from the updates related to the wavelength calibration: the RMS error of the fit is reduced by 23% and the NO2 slant column by 0.85 1015 molec cm-2, independent of latitude, solar zenith angle and NO2 value. Including O2–O2 and liquid water absorption and updating the O3 and water vapour cross-section spectra further reduces NO2 slant columns on average by 0.35 1015 molec cm-2, accompanied by a further 9% reduction in the RMS error of the fit. The improved OMI NO2 slant columns are consistent with independent NO2 retrievals from other instruments to within a range that can be explained by photochemically driven diurnal increases in stratospheric NO2 and by small differences in fitting window and approach. The revisions indicate that current OMI NO2 slant columns suffered mostly from an additive positive offset, which is removed by the improved wavelength calibration and representation of the OMI slit function. It is therefore anticipated that the improved NO2 slant columns are most important to retrievals of spatially homogeneous stratospheric NO2 rather than to heterogeneous tropospheric NO2. [less ▲]

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See detailEstimated Subglottic Pressure Evaluation, Evolution in 152 Dysphonic Patients
Morsomme, Dominique ULg; Finck, Camille ULg; Larrouy, Pauline ULg

Conference (2015, April 08)

Background: Estimated subglottic pressure (ESGP) is part of the aerodynamic measurements included in the vocal profile. It is an indication of vocal effort. Speyer reports an improvement of the ESGP score ... [more ▼]

Background: Estimated subglottic pressure (ESGP) is part of the aerodynamic measurements included in the vocal profile. It is an indication of vocal effort. Speyer reports an improvement of the ESGP score after voice treatment. Nevertheless, few studies used ESGP to evaluate voice efficiency treatment. Objectives: The purpose is to examine the ESGP twice, at the first (T1) and the last consultation (T2) . We observe the ESGP values according to voice pathology. We also examine the relationships between ESGP, SPL(Sound pressure level) and DSI (Discorder severity index) . Method: The study includes 130 patients (M:31/W:99), which suffer from 4 different pathologies as immobility (N: 54), oedema (N:23), nodules (N:24) and polyp (N:29). Each patient’s file consists of VLS, acoustic, aerodynamic and perceptual measures. The ESGP was collected through the Phonatory Aerodynamic System Model 6600 (KayPentax). Patients produced 3 sequences of / ipipi / at low (IL), conversational (IC) and high (IH) intensity. Patients were grouped according to the ENT’s diagnosis. We compare our values to those of Zraick et al (2012) which studied ESGP on a healthy group. Results: At T2, for the all patients, at minimum and conversational intensity the ESGP scores decrease singificantly, even if those scores were higher than for the healthy group. We observe a negative correlation between ESGP and SPL at low and conversational intensity. At T1, the higher is the ESGP score, the lower is the SPL score. At T2, the higher is the ESGP score, the higher is the SPL score. At T1, a negative correlation is observed between ESGP and DSI for 2 groups of patients (immobility and polyp) only at minimum intensity. The higher is the ESGP, the lower is SPL. At T2, only for the group immobility, the negative correlation persists. Conclusion: This study highlights the importance of considering the ESGP as a parameter of efficiency. High ESGP is mainly connected with patients who suffer from pathology. The patient who suffer from immobility seems to present a specific profile which could help the clinician to better understand their vocal behavior. Recommendation: This study highlights the pertinence of considering the ESGP as a parameter of vocal treatment efficiency. [less ▲]

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See detailAging Mechanisms in Amorphous GeTe
Raty, Jean-Yves ULg; Zhang, Wei; Luckas, Jennifer et al

Conference (2015, April 08)

We investigate the structure of amorphous GeTe using Density Functional Theory based Molecular Dynamics, using either the standard Generalized Gradient Approximation, or the more elaborate Van der Waals ... [more ▼]

We investigate the structure of amorphous GeTe using Density Functional Theory based Molecular Dynamics, using either the standard Generalized Gradient Approximation, or the more elaborate Van der Waals approximation. New insight is provided on the stability of homopolar GeGe bonds and tetrahedral Ge bonding, in relation with the resistance drift phenomenon, that is investigated experimentally using photothermal deflection spectroscopy experiments. Aging phenomena are common to all amorphous structures, but of special importance in phase change materials (PCM) since it impedes the realization of multi-level memories. Different interpretations have been proposed, but we focus here on the structural relaxation of amorphous GeTe, chosen because it is the simplest system that is representative of the wider class of GST alloys, lying along the GeTe-Sb2Te3 composition line of the GeSbTe phase diagram. Since the structural relaxations concerned with the drift take place on long time scales, the task of understanding them to limit their consequences is not a simple one. We successfully achieved this goal by developing new approaches to overcome a series of hurdles. A first problem is that directly generating an amorphous structure by quenching a liquid using Density Functional Theory (DFT) based Molecular Dynamics leads to one sample with a small number of atom (typically a few hundreds), and, hence of small number of atomic environments. Here we sample a large number of local atomic environments, corresponding to different bonding schemes, by chemically substituting different alloys, selected to favor different local atomic structures. This enables spanning a larger fraction of the configuration space relevant to aging. A second aspect is that GST alloys are known to display complex bonding mechanisms, for which the simple chemist’s “octet-rule” does not apply, leading a long series of controversies, concerning in particular the local structure around Ge atoms. We overcome this problem by using state of the art non local DFT-MD, including the so-called van der Waals corrections. This leads to more clearly defined environments that are thoroughly analyzed. We can then identify their fingerprints in the available structural experimental data and assess the stability of these local environments to obtain information of the driving forces leading to the structural relaxation. The calculated electronic properties nicely match the most recent photothermal deflection spectroscopy experiments that are presented here. Our results support a model of the amorphous phase and its time evolution that involves an evolution of the local (chemical) order towards that of the crystal (by getting rid of homopolar bonds), and an evolution of its electronic properties that drift away from those of the crystal, driven by an increase of the Peierls-like distortion of the local environments in the amorphous, as compared to the crystal. [less ▲]

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See detailGCxGC-TOFMS and supervised multivariate approaches to study human cadaveric decomposition olfactive signatures
Stefanuto, Pierre-Hugues ULg; Perrault, Katelynn A.; Stadler, Sonja et al

in Analytical Bioanalytical Chemistry (2015), 407(16), 4767-4778

In forensic thanato-chemistry, the understanding of the process of soft tissue decomposition is still limited. A better understanding of the decomposition process and the characterization of the ... [more ▼]

In forensic thanato-chemistry, the understanding of the process of soft tissue decomposition is still limited. A better understanding of the decomposition process and the characterization of the associated volatile organic compounds (VOC) can help to improve the training of victim recovery (VR) canines, which are used to search for trapped victims in natural disasters or to locate corpses during criminal investigations. The complexity of matrices and the dynamic nature of this process require the use of comprehensive analytical methods for investigation. Moreover, the variability of the environment and between individuals creates additional difficulties in terms of normalization. The resolution of the complex mixture of VOCs emitted by a decaying corpse can be improved using comprehensive two-dimensional gas chromatography (GC× GC), compared to classical singledimensional gas chromatography (1DGC). This study combines the analytical advantages of GC×GC coupled to timeof- flight mass spectrometry (TOFMS) with the data handling robustness of supervised multivariate statistics to investigate the VOC profile of human remains during early stages of decomposition. Various supervised multivariate approaches are compared to interpret the large data set. Moreover, early decomposition stages of pig carcasses (typically used as human surrogates in field studies) are also monitored to obtain a direct comparison of the two VOC profiles and estimate the robustness of this human decomposition analog model. In this research, we demonstrate that pig and human decomposition processes can be described by the same trends for the major compounds produced during the early stages of soft tissue decomposition. [less ▲]

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See detailState of the art on drivers of deforestation in the Congo basin tropical forest
Gillet, Pauline ULg; Vermeulen, Cédric ULg; Dessard, Hélène et al

Conference (2015, April 07)

The Congo basin forest experiment a low pressure on biodiversity in comparison to other rainforests around the world. But according to the predictions, climate change and direct human drivers could have ... [more ▼]

The Congo basin forest experiment a low pressure on biodiversity in comparison to other rainforests around the world. But according to the predictions, climate change and direct human drivers could have an important effect on the deforestation rate. In that context, CoForTips project want to foster a better management of the Congo Basin forests through a better understanding of the dynamics, regime shifts and tipping points of biodiversity and a better definition of the conditions of resilience of social and ecological systems. In order to assess the current knowledge about drivers of deforestation in the world tropical forests, we analyzed the existent literature to list the direct and indirect drivers of deforestation in the forested tropical zones and to focus on deforestation in the Congo Basin forest and specifically in Cameroon and Gabon. We listed direct drivers of deforestation like expansion of agriculture which can be either family farming or agribusiness; timber extraction for softwood industry and fuel wood; development of infrastructure leading to the opening up of forested land and populations, and mining industries. The underlying causes found in the literature concern economic factors like gross domestic product, national income based on environmental resources exploitation and consumer demand expressing on local and global markets. Technological factors that allow much larger removal. Cultural issues like representation of the forest in the collective imagination as an important source of economic income. Institutional factors like policy measures advocating pro-deforestation measures and demographic causes taking into account for local population rise due to a high fertility rate and linked to population migration. Those direct and underlying causes of deforestation where then detailed for Cameroon and Gabon. [less ▲]

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