Residential equilibrium in a multifractal metropolitan area

A residential location model derived from urban economics is combined with the geometry of a multifractal Sierpinski carpet to represent and model a metropolitan area. This area is made up of a system of built-up patches hierarchically organised around a city centre, and green areas arranged in an inverse hierarchical order (large open-spaces in the periphery). An analytical solution is obtained by using a specific geographic coding system for computing distances. The values of the parameters used in the model are based on the French medium sized metropolitan areas; a realistic benchmark is proposed and comparative-statics simulations are performed. The results show that the French peri-urbanisation process (which took place from 1970 onward) can be explained by an increase in income and a reduction in transport costs. Nevertheless, changes in household preferences, in particular an increased taste for open spaces, can also contribute to urban sprawl by making the gradient of land rents less steep and by making peripheral household locations more desirableperi-urban, residential localisation, fractal geometry, amenities

Residential Equilibrium in a Multifractal Metropolitan Area.

In this paper, an urban economic model of residential location is combined with multifractal geometry (Sierpinski carpet) in order to model and analyse the spatial structure of a metropolitan area. This area is made of an urban system organised hierarchically around a central CBD, as well as of green spaces that have an inverse hierarchical organisation. The properties of the model are studied by means of analytical solutions. Then, simulation are made, which are based of French urban realities. This enables one to choose realistic parameters and to analyse the effects of several modelling assumptions (changes in preferences, economic shocks, …). The modelling results show that French periurbanisation of the last 30 years can be explained by the increase in income and by the decrease in transportation costs, probably without any changes in households preferences

Flash floods and muddy floods in Wallonia: recent temporal trends, spatial distribution and reconstruction of the hydrosedimentological fluxes using flood marks and sediment deposits

Flash floods and muddy floods may cause severe human and material damage despite their small spatial extent and low occurrence. In late May 2008, a major event has affected the area of Liège. This paper describes the methodology used to reconstruct the hydrosedimentological parameters of the flood from the geomorphological evidences observed in the field. Bed load and suspended load transport rates estimated during this extreme event were compared to the average values observed in other Walloon rivers and more specifically in the Ardennes Massif. The spatial distribution and the temporal evolution of the flash flood and muddy flood events are then analysed across Wallonia based on several works compiling press archives since the early twentieth century. The biases associated with this type of historical sources and the consequences of flash floods and muddy floods on the vulnerability and the risk of flooding in Wallonia are finally addressed.Les crues éclairs et les coulées boueuses, malgré leur extension spatiale réduite et leur occurrence peu fréquente, peuvent être à l’origine de dégâts importants tant sur le plan matériel que sur le plan humain. Fin mai 2008, un événement majeur a affecté la région liégeoise. Ce papier décrit la méthodologie employée pour reconstituer, en milieu forestier, ses paramètres hydrosédimentologiques à partir des éléments géomorphologiques observés sur le terrain. Les taux de transport de la charge de fond et de la charge en suspension au cours de cet événement extrême sont comparés aux valeurs moyennes observées dans d’autres rivières wallonnes et plus spécifiquement dans le massif ardennais. La répartition spatiale et l’évolution temporelle des crues éclairs sont ensuite analysées à l’échelle de la Wallonie sur base de plusieurs travaux académiques compilant l’ensemble des événements recensés dans la presse depuis le début du XXème siècle. Les biais liés à ce type de sources historiques sont abordés ainsi que les conséquences des crues éclairs sur la vulnérabilité et le risque d’inondation soudaine en Wallonie

Notes de lecture

"Jacques BAUDOU: Jean-Jacques SCHLERET, Merveilleux, fantastique et science-fiction à la télévision française", par Marc Lits; "Gilbert DURAND: Introduction à la mythodologie. Mythes et sociétés", par Marc Lits; "Pierre GLAUDES: Yves REUTER, Personnages et didactique du récit", par Marc Lits; "Pierre LéVY: Qu'est-ce que le virtuel ?", par Hugues Peeters; "Michel MAFFESOLI: éloge de la raison sensible", par Caroline Huynen; "Francisco J. VARELA, Quel savoir pour l'éthique ? Action sagesse et cognition", par Jean-Pierre Meunier"Jacques BAUDOU: Jean-Jacques SCHLERET, Merveilleux, fantastique et science-fiction à la télévision française", par Marc Lits; "Gilbert DURAND: Introduction à la mythodologie. Mythes et sociétés", par Marc Lits; "Pierre GLAUDES: Yves REUTER, Personnages et didactique du récit", par Marc Lits; "Pierre LéVY: Qu'est-ce que le virtuel ?", par Hugues Peeters; "Michel MAFFESOLI: éloge de la raison sensible", par Caroline Huynen; "Francisco J. VARELA, Quel savoir pour l'éthique ? Action sagesse et cognition", par Jean-Pierre Meunie

Role of the High Affinity Immunoglobulin E Receptor in Bacterial Translocation and Intestinal Inflammation

A role for immunoglobulin E and its high affinity receptor (FcεRI) in the control of bacterial pathogenicity and intestinal inflammation has been suggested, but relevant animal models are lacking. Here we compare transgenic mice expressing a humanized FcεRI (hFcεRI), with a cell distribution similar to that in humans, to FcεRI-deficient animals. In hFcεRI transgenic mice, levels of colonic interleukin 4 were higher, the composition of fecal flora was greatly modified, and bacterial translocation towards mesenteric lymph nodes was increased. In hFcεRI transgenic mice, 2,4,6-tri-nitrobenzenesulfonic acid (TNBS)-induced colitis was also more pronounced, whereas FcεRI-deficient animals were protected from colitis, demonstrating that FcεRI can affect the onset of intestinal inflammation

Housing land transaction data and structural econometric estimation of preference parameters for urban economic simulation models

This paper describes a dataset of 6284 land transactions prices and plot surfaces in 3 medium-sized cities in France (Besançon, Dijon and Brest). The dataset includes road accessibility as obtained from a minimization algorithm, and the amount of green space available to households in the neighborhood of the transactions, as evaluated from a land cover dataset. Further to the data presentation, the paper describes how these variables can be used to estimate the non-observable parameters of a residential choice function explicitly derived from a microeconomic model. The estimates are used by Caruso et al. (2015) to run a calibrated microeconomic urban growth simulation model where households are assumed to trade-off accessibility and local green space amenities

Incidence, natural course, and outcome of type II endoleaks in infrarenal endovascular aneurysm repair based on the ENGAGE registry data

Objective: The purpose of this study was to report the incidence, natural history, and outcome of type II endoleaks in the largest prospective real-world cohort to date. Methods: Patients were extracted from the prospective Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE). Two groups were analyzed: first, patients with an isolated type II endoleak; and second, patients with a type II endoleak who later presented with a type I endoleak. A health status analysis between patients with an early type II endoleak and patients with no endoleak was performed. Second, an attempt was made to identify risk factors in patients with a type II endoleak who later presented with a type I endoleak. Results: Through 5 years of follow-up, a total of 197 (15.6%) patients with isolated type II endoleaks were identified. Most were detected within the first 30 days (n = 73 [37.1%]) and through the first year (n = 73 [37.1%]), with the remainder being detected after 1 year of follow-up (n = 51 [25.8%]). Patients with a type II endoleak had a higher incidence of aneurysm growth and more secondary endovascular procedures (15.4% vs 7.5% at 5 years; P <.001). Overall survival was higher in the isolated type II endoleak group compared with patients with no endoleak (77.2% vs 67.0% at 5 years; P =.010). Twenty-two patients (10%) with a type II endoleak were diagnosed with a late type I endoleak (type IA, n = 10; type IB, n = 12), with a secondary intervention rate of 67.5% through 5 years. There was no difference in health status scores between patients with an early type II endoleak and patients without any type of endoleak at 1-year follow-up. Conclusions: In the ENGAGE registry, isolated type II endoleaks are present in 15.6% of patients during follow-up. The majority do not require secondary intervention, and an early isolated type II endoleak does not have an impact on health status through 1 year. However, a small group of patients with a type II endoleak will present with a type I endoleak, resulting in a high secondary intervention rate and significant risk of aneurysm-related complications