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Conference given outside the academic context (2012)

Algorithms for testing the collective consumption model

Conference (2012, November 09)

In this talk, we discuss an extension of the strong axiom of revealed preferences to collective households. The question that we address is whether a set of observed consumption baskets can be decomposed ... [more ▼]

In this talk, we discuss an extension of the strong axiom of revealed preferences to collective households. The question that we address is whether a set of observed consumption baskets can be decomposed in such a way that each of the derived data sets reflects the choices of a “rational” (i.e., utility-maximizing) individual member of the household. Although testing revealed preference axioms on data generated by a single decisionmaker can be done in polynomial time, the extension to two-member households is NP-complete. We propose two algorithms for testing the collective consumption model on large data sets. The first one is an exact algorithm based on a new mixed-integer programming formulation, whereas the second one is a heuristic based on a simulated annealing procedure that solves a global optimization formulation of the problem. Computational experiments are performed on real-life data. [less ▲]

Hippocrate dans un monde de chrétiens : la réception des traités hippocratiques dans la chôra égyptienne à la période byzantine (284-641)

Conference (2012, November 09)

Dans le cadre d'une recherche sur la réception des œuvres des auteurs de l’antiquité classique dans l’Égypte christianisée, on examine les témoignages papyrologiques de la période byzantine relatifs aux ... [more ▼]

Dans le cadre d'une recherche sur la réception des œuvres des auteurs de l’antiquité classique dans l’Égypte christianisée, on examine les témoignages papyrologiques de la période byzantine relatifs aux traités hippocratiques, leur texte, leur mise en texte et leur contexte, en vue, non seulement de définir leur spécificité par rapport aux autres papyrus grecs médicaux et aux papyrus iatro-magiques de la même époque, mais aussi d’y déceler des traces éventuelles de copie ou d’utilisation en contexte chrétien. [less ▲]

Cerebral aspergillosis in immunocompromised patient successfully treated with voriconazole

Poster (2012, November 08)

Cerebral aspergillosis is a severe invasive mycosis occurring in immunocompromised patients. This pathology is associated with a high rate of mortality and is a current complication of pulmonary invasive ... [more ▼]

Cerebral aspergillosis is a severe invasive mycosis occurring in immunocompromised patients. This pathology is associated with a high rate of mortality and is a current complication of pulmonary invasive aspergillosis. We report the case of a 44-year-old immunocompromised male with a recent history of oropharyngeal carcinoma. At his admission the patient presented with fever and confusion. Imaging revealed the presence of a cerebral abscess combined with lung infiltrates. During hospitalization and despite a broad-spectrum antibiotic regimen his condition worsened. A thin needle aspiration of the abscess was performed for diagnosis purpose. Histological examination of the tissue showed septate and branched hyphae with 45° angles suggestive of Aspergillus. A real-time PCR specific for the detection of Aspergillus sp. was carried out and confirmed the fungal etiology of the abscess. Rare colonies of A. fumigatus were isolated a few days later. The diagnosis of invasive pulmonary aspergillosis complicated by a cerebral dissemination was confirmed. Antifungal treatment based on voriconazole 4 mg/kg q12h was introduced and the dosage was successfully increased up to 5 mg/kg q12h by drug monitoring. This case highlights the usefulness of the Aspergillus PCR for the rapid identification of hyphae in tissue biopsies (or in the event of negative culture), and the importance of therapeutic drug monitoring in treatment by voriconazole. [less ▲]

Accompagnement des aidants des patients Alzheimer comme approche non-pharmacologique essentielle!

Conference (2012, November 08)

Greenland ice-sheet contribution to sea-level rise buffered by meltwater storage in firn

in Nature (2012), 491

Surface melt on the Greenland ice sheet has shown increasing trends in areal extent and duration since the beginning of the satellite era. Records for melt were broken in 2005, 2007, 2010 and 2012. Much ... [more ▼]

Surface melt on the Greenland ice sheet has shown increasing trends in areal extent and duration since the beginning of the satellite era. Records for melt were broken in 2005, 2007, 2010 and 2012. Much of the increased surface melt is occurring in the percolation zone, a region of the accumulation area that is perennially covered by snow and firn (partly compacted snow). The fate of melt water in the percolation zone is poorly constrained: some may travel away from its point of origin and eventually influence the ice sheet’s flow dynamics and mass balance and the global sea level, whereas some may simply infiltrate into cold snow or firn and refreeze with none of these effects. Here we quantify the existing water storage capacity of the percolation zone of the Greenland ice sheet and show the potential for hundreds of gigatonnes of meltwater storage. We collected in situ observations of firn structure and meltwater retention along a roughly 85-kilometre-long transect of the melting accumulation area. Our data show that repeated infiltration events in which melt water penetrates deeply (more than 10 metres) eventually fill all pore space with water. As future surface melt intensifies under Arctic warming, a fraction of melt water that would otherwise contribute to sea-level rise will fill existing pore space of the percolation zone. We estimate the lower and upper bounds of this storage sink to be 322 ± 44 gigatonnes and 1.289 gigatonnes, respectively. Furthermore, we find that decades are required to fill this pore space under a range of plausible future climate conditions. Hence, routing of surface melt water into filling the pore space of the firn column will delay expansion of the area contributing to sea-level rise, although once the pore space is filled it cannot quickly be regenerated. [less ▲]

21st century projections of surface mass balance changes for major drainage systems of the Greenland ice sheet

in Environmental Research Letters (2012), 7

Outputs from the regional climate model Modèle Atmosphérique Régionale at a spatial resolution of 25 km are used to study 21st century projected surface mass balance (SMB) over six major drainage basins ... [more ▼]

Outputs from the regional climate model Modèle Atmosphérique Régionale at a spatial resolution of 25 km are used to study 21st century projected surface mass balance (SMB) over six major drainage basins of the Greenland ice sheet (GrIS). The regional model is forced with the outputs of three different Earth System Models (CanESM2, NorESM1 and MIROC5) obtained when considering two greenhouse gas future scenarios with levels of CO2 equivalent of, respectively, 850 and >1370 ppm by 2100. Results indicate that the increase in runoff due to warming will exceed the increased precipitation deriving from the increase in evaporation for all basins, with the amount of net loss of mass at the surface varying spatially. Basins along the southwest and north coast are projected to have the highest sensitivity of SMB to increasing temperatures. For these basins, the global temperature anomaly corresponding to a decrease of the SMB below the 1980–99 average (when the ice sheet was near the equilibrium) ranges between +0.60 and +2.16 °C. For the basins along the northwest and northeast, these values range between +1.50 and +3.40 °C. Our results are conservative as they do not account for ice dynamics and changes in the ice sheet topography. [less ▲]

Can satellites help organic crop certification?

Poster (2012, November 08)

Organic agriculture, while producing healthy food and contributing to protect the environment, needs to be certified in order to meet the consumers confidence. The objective of this study was to ... [more ▼]

Organic agriculture, while producing healthy food and contributing to protect the environment, needs to be certified in order to meet the consumers confidence. The objective of this study was to investigate how earth observation techniques could enhance the crop certification process and in particular the possibility to discriminate organic and conventional fields. These different crop management methods results in crop biophysical differences which are supposed to be observable by earth observation techniques. A set of satellites with varying spatial and spectral resolution was used to compute discriminant indicators. Under the best conditions the results show a complete discrimination between organic and conventional crops. [less ▲]

Le corpus jésuite. Formes et enjeux

Scientific conference (2012, November 08)

Révision de la Carte Numérique des Sols de Wallonie - Campagne de recherche 2012-2013 - Premier rapport intermédiaire

Report (2012)