neXtSIM: a new Lagrangian sea ice model

The Arctic sea ice cover has changed drastically over the last decades. Associated with these changes is a shift in dynamical regime seen by an increase of extreme fracturing events and an acceleration of sea ice drift. The highly non-linear dynamical response of sea ice to external forcing makes modelling these changes and the future evolution of Arctic sea ice a challenge for current models. It is, however, increasingly important that this challenge be better met, both because of the important role of sea ice in the climate system and because of the steady increase of industrial operations in the Arctic. In this paper we present a new dynamical/thermodynamical sea ice model called neXtSIM that is designed to address this challenge. neXtSIM is a continuous and fully Lagrangian model, whose momentum equation is discretised with the finite-element method. In this model, sea ice physics are driven by the combination of two core components: a model for sea ice dynamics built on a mechanical framework using an elasto-brittle rheology, and a model for sea ice thermodynamics providing damage healing for the mechanical framework. The evaluation of the model performance for the Arctic is presented for the period September 2007 to October 2008 and shows that observed multi-scale statistical properties of sea ice drift and deformation are well captured as well as the seasonal cycles of ice volume, area, and extent. These results show that neXtSIM is an appropriate tool for simulating sea ice over a wide range of spatial and temporal scales

Mapping wildland-urban interfaces at large scales integrating housing density and vegetation aggregation for fire prevention in the South of France

Every year, more than 50,000 wildland fires affect about 500,000 ha of vegetation in southern European countries, particularly in wildland-urban interfaces (WUI). This paper presents a method to characterize and map WUIs at large scales and over large areas for wildland fire prevention in the South of France. Based on the combination of four types of building configuration and three classes of vegetation structure, 12 interface types were classified. Through spatial analysis, fire ignition density and burned area ratio were linked with the different types of WUI. Among WUI types, isolated WUIs with the lowest housing density represent the highest level of fire risk

Compartmental pharmacokinetics of nefopam during mild hypothermia

Background Nefopam is a non-opioid, non-steroidal, centrally acting analgesic which has an opioid-sparing effect. It also reduces the threshold (triggering core temperature) for shivering without causing sedation or respiratory depression. The drug is therefore useful as both an analgesic and to facilitate induction of therapeutic hypothermia. However, compartmental pharmacokinetics during hypothermia are lacking for nefopam. Methods We conducted a prospective, randomized, blinded study in eight volunteers. On two different occasions, one of two nefopam concentrations was administered and more than 30 arterial blood samples were gathered during 12 h. Plasma concentrations were determined using gas chromatography/mass spectrometry to investigate the pharmacokinetics of nefopam with non-linear mixed-effect modelling. Results A two-compartment mammillary model with moderate inter-individual variability and inter-occasional variability independent of covariates was found to best describe the data [mean (se): V1=24.13 (2.8) litre; V2=183.34 (13.5) litre; Clel=0.54 (0.07) litre min−1; Cldist=2.84 (0.42) litre min−1]. Conclusions The compartmental data set describing a two-compartment model was determined and could be implemented to drive automated pumps. Thus, work load could be distributed to a pump establishing and maintaining any desired plasma concentration deemed necessary for a treatment with therapeutical hypothermi

Hidromedusas profundas del Mediterráneo: Un estudio que incluye la descripción de dos nuevas especies recolectadas en cañones submarinos del Mediterráneo Occidental

Two new species of hydromedusae (Foersteria antoniae and Cunina simplex) are described from plankton collected in sediment traps placed in the Lacaze-Duthiers Submarine Canyon and along Banyuls-sur-Mer coast (northwestern Mediterranean). The Mediterranean hydromedusan deep-water fauna contains 41 species which represent 45.5 % of the world-wide deep-sea hydromedusae fauna (90) and 20% of the total number of Mediterranean hydromedusae (204). The Mediterranean deep-water hydromedusan fauna is characterised by a large percentage of holoplanktonic species (61%), mainly Trachymedusae. Nevertheless, contrary to the general opinion, the percentage of meroplanktonic species is equally high. The most original features of this fauna lies however in the importance of the number of endemic species (22%) and in the fact that the majority of them are meroplanktonic Leptomedusae with a supposed bathybenthic stage. Some of the endemic species could still represent relics of the primitive Tethys fauna having survived to the Messinian crisis. The origin of the Mediterranean deep-water hydromedusan fauna is discussed and a general hypothesis is proposed.Se describen dos especies nuevas a partir de ejemplares recolectados mediante trampas de sedimento del cañón submarino de Lacaze-Duthiers situado en frente de la costa de Banyuls-sur-Mer (Mediterráneo noroccidental). La fauna profunda de hydromedusas en el Mediterráneo contiene 41 especies que representan 45.5 % de la fauna mundial del grupo y el 20% de la fauna de hydromedusas del Mediterráneo. La fauna Mediterránea de hydromedusas profundas se caracteriza por un gran porcentaje de especies holoplanctónicas (61%), fundamentalmente Trachymedusas, sin embargo, contrario a la opinión generalizada, el porcentaje de especies meroplanctónicas es igualmente importante (39%). La característica más interesante de esta fauna es el número de especies endémicas (22%) y el hecho de que la mayoría de estas especies son meroplanctónicas (Leptomedusas) con una supuesta fase bentónica. Algunas de estas especies endémicas, podrían ser especies relictas (endémica insular) de la fauna primitiva del Tetis que sobrevivieron a la crisis Mesiniana. Se discute el origen de la fauna de hydromedusas profundas en el Mediterráneo y se presenta una nueva hipótesis