Hepatitis C virus budding at lipid droplet-associated ER membrane visualized by 3D electron microscopy.

The original publication is available at www.springerlink.comInternational audienceThe mechanisms underlying hepatitis C virus (HCV) morphogenesis remain elusive, but lipid droplets have recently been shown to be important organelles for virus production. We investigated the interaction between HCV-like particles and lipid droplets by three-dimensional reconstructions of serial ultrathin electron microscopy sections of cells producing the HCV core protein. The budding of HCV-like particles was mostly initiated at membranes close to the lipid droplets rather than at membranes directly apposed to the lipid droplets. This may have important implications for our understanding of the complex relationship between HCV and lipids and may make easier to dissect out the HCV life cycle

L’établissement rural de La Tène finale du « Vau Blanchard » à Lavernat (Sarthe) : vers un plan type de la ferme gauloise ?

Sur la commune de Lavernat, dans le sud du département de la Sarthe, la campagne de prospection archéologique systématique effectuée sur le tracé de la future autoroute A28, a permis au niveau de l’échangeur de Montabon, près de Château-du-Loir, de mettre en évidence un enclos de plan trapézoïdal d’une base de 101m pour une hauteur de 77m, circonscrivant une surface de 6500m2. À ce jour, il s’agit d’une des rares fermes indigène de La Tène finale fouillée exhaustivement dans le département de la Sarthe. Cette ferme est matérialisée au sol par des structures fossoyées arasées. Le décapage mécanique intégral de l’aire interne y a révélé un seul bâtiment d’habitat complété d’un grenier et d’un puits à eau. Quelques centaines de tessons, des plaques de foyers et des meules constituent l’essentiel des vestiges matériels exhumés tandis que de rares vestiges du iersiècle de notre ère matérialisent l’abandon du site. De nombreux établissements ruraux très comparables permettent d’évoquer un plan-type au sein des découvertes effectuées dans l’ouest de la Gaule.Near Château-du-Loir in the south of Sarthe, in the Commune of Lavernat, a systematic archaeological survey carried out along the planned route of the A 28, uncovered, at the Montabon junction, has uncovered a trapezoid enclosure 101 m by 77 m, encompassing an area of 6500 sq.m. This thoroughly excavated site is a rare example in the Sarthe of a “native” farmstead dating from the Late La Tene period. The settlement appears as eroded earthworks. Complete mechanical scraping of the interior revealed a single domestic building, a storage area and a well. Several hundred shards, some hearths slabs and querns are the main associated finds. A very few remains dating from the Ist century AD indicate when the site was finally abandoned. Many quite similar farmsteads suggest that a typical layout may emerge from all the discoveries yet made in Western Gaul

Evaluation of floristic diversity in urban areas as a basis for habitat management

International audienceQuestions: How can floristic diversity be evaluated in conser‐vation plans to identify sites of highest interest for biodiversity? What are the mechanisms influencing the distribution of species in human‐dominated environments? What are the best criteria to identify sites where active urban management is most likely to enhance floristic diversity?Location: The Hauts‐de‐Seine district bordering Paris, France.Methods: We described the floristic diversity in one of the most urbanized French districts through the inventory of ca. 1000 sites located in 23 habitats. We built a new index of floristic interest (IFI), integrating information on richness, indigeneity, typicality and rarity of species, to identify sites and habitats of highest interest for conservation. Finally, we explored the relationship between site IFI and land use patterns (LUP).Results: We observed a total of 626 vascular plant species. Habitats with highest IFI were typically situated in seminatural environments or environments with moderate human impact. We also showed that neighbouring (urban) structures had a significant influence on the floristic interest of sites: for example, the presence of collective dwellings around a site had a strong negative impact on IFI.Conclusions: Our approach can be used to optimize management in urban zones; we illustrate such possibilities by defining a ‘Site Potential Value’, which was then compared with the observed IFI, to identify areas (e.g. river banks) where better management could improve the district's biodiversity

Modelling Of An Automotive Multi-Evaporator Air-Conditioning System

With the arrival of plug-in hybrid electric vehicles (PHEV) and battery electric vehicles (BEV) with significant autonomy, battery cooling becomes a necessity in driving mode to ensure their durability and ability to charge rapidly.  For these vehicles, the refrigerating system may be composed of two evaporators (for front and rear passengers) in order to afford cooled air in the cabin and a chiller or a built-in battery evaporator to cool down the traction battery. This kind of multi-evaporator air-conditioning system has a number of technological barriers that must be undone. They are related to the components sizing in a context of cost reduction and control of such complex systems. The study therefore focuses on understanding the dynamic coupling of the several loop components such as the three evaporators having different cooling capacities. Understanding the behaviour of their respective expansion devices and the choice of these latter is also essential to control properly the transient phase and ensure an optimal operation of the air-conditioning system. In the literature, the effect of battery cooling by means of a chiller on the automotive air-conditioning loop has been already proved by simulation in the Dymola® [1] environment. The simulation results for several driving cycles, refrigerants and ambient conditions emphasize the thermal discomfort caused by the use of the chiller loop. However, no global control strategy has been established. More recently, a first study of an air conditioning system model with three evaporators was carried out [2]. After the validation of their component models, a cool down test was performed to test the performance of their air conditioning system. From a control point of view, a simple PI control on the temperature of air blown at the front evaporator was used to regulate the speed of the compressor. In the building sector [3], the benefits of a supervisory controller to regulate the multi-evaporator air conditioning system was developed. Although this type of decentralized model seems to be robust and applicable to the car, it requires the use of sensors and components currently too costly and subject to a less restrictive environment than in automotive. The challenge of such a cooling loop lies in the dynamic coupling of components as well as their design. The model of a multi-evaporator automotive air conditioning system (two evaporators and a chiller) is thus produced using the 0D AMESim® software. In order to obtain more representative results in the transient state, the majority of components, including the chiller and regulators, are physical models giving a good representation of their internal geometries. These models were validated using experimental test maps. The first results highlight the importance of the regulators choice on the loop stability. A comparison of several types of expansion valves (orifice, thermostatic and electronic) will be conducted in order to select the most suitable to meet the price-performance compromise. Finally, control strategies are studied in transient state to further improve the stability and speed of convergence to the target instructions

RELATIONSHIP BETWEEN FORMATION OF THE FEMORAL BICONDYLAR ANGLE AND TROCHLEAR SHAPE. INDEPENDENCE OF DIAPHYSEAL AND EPIPHYSEAL GROWTH

During hominin evolution, an increase in the femoral bicondylar angle was the initial change that led to selection for protuberance of the lateral trochlear lip and elliptical profile of the lateral condyle. No correlation is found during ontogeny between the degree of femoral obliquity and of the prominence of the lateral trochlear lip. Might there be then a relationship with the elliptical profile of the lateral condyle ? On intact femoral diaphyses of juvenile humans and great apes, we compared the anteroposterior length of the lateral and medial sides of the distal metaphysis. The two diaphyseal pillars remain equal during postnatal growth in great apes, while the growth of the lateral pillar far exceeds that of the medial pillar in humans. Increase in bicondylar angle is correlated with disproportionate anteroposterior lengthening of the lateral pillar. The increased anteroposterior length of the lateral side of the metaphysis would contribute to increasing the radius of curvature of the lateral condyle, but not to projection of the lateral trochlear lip. The similar neonatal and adult femoro-patellar joint shape in humans prompted an assessment of the similarity during growth of the entire neonatal and adult epiphyses. We showed that the entire epiphysis undergoes drastic changes in proportions during postnatal growth. Finally, we emphasize the need to distinguish the cartilaginous phenotype and the ossified phenotype of the distal femoral epiphysis -and of any epiphysis- during postnatal growth. This crucial distinction applies to most postcranial bones for they almost all develop following the process of endochondral ossification

Organo-mineral imprints in fossil cyanobacterial mats of an Antarctic lake

peer reviewe

Le site gaulois et antique de « La Carie », entre oppidum et ville romaine à Entrammes (Mayenne)

À mi-chemin entre oppidum gaulois et thermes antiques, le site de « La Carie » à Entrammes, installé près d’un gué sur un affluent de la Mayenne, a livré une succession stratigraphique débutant vers le milieu de La Tène moyenne, prenant son ampleur au Haut-Empire et finissant par une petite nécropole mérovingienne. Ces éléments s’organisent au sud, puis des deux côtés d’une large voie gauloise puis antique. L’habitat gaulois, peu dense, va en se complexifiant avant un abandon vers la fin de La Tène D1. Sur les mêmes bases, le site est réoccupé à partir de Tibère, des fours de potiers marquant la création d’une zone artisanale périphérique au nouveau chef-lieu du pagus gallo-romain d’Entrammes. À la période flavienne, de nouvelles structures sont élevées et agrandies jusqu’au début de la période sévérienne. Au Bas-Empire, si l’habitat est abandonné, la voie continue d’être utilisée ; une petite nécropole mérovingienne atteste de la permanence de cette dernière au moins jusqu’au viiie siècle. Enfin, mentionnons qu’un abondant mobilier, peu diversifié, illustre l’occupation, essentiellement de la période gauloise à la fin du Haut-Empire.Midway between the Gallic oppidum and the ancient spa, just before a ford on a Mayenne tributary, the site of “La Carie” at Entrammes has yielded a stratigraphic succession dating from the mid Celtic (La Tène) period, reaching its zenith during the time of the early Roman Empire with its end denoted by a small Merovingian necropolis. These elements are all arranged firstly to the south and then on either side of a large ancient Gallic well. Gallic habitation, firstly insignificant, became more complex before being abandoned towards the end of La Tène D1. Using the same base, the site was reoccupied from the time of Tiberius; potter’s kilns indicating the installation of a craft area were found on the periphery of the new administrative town of Entrammes, the former pagus. During the Flavian period, further structures were erected and enlarged through to the beginning of the Severan period. During the Late Empire, although the habitation was abandoned, the road continued to be used; a small Merovingian necropolis ensuring its permanence up to at least the fifteenth century. Finally, we should mention that abundant furniture, not particularly varied, illustrates occupation primarily from the Gallic period to the end of the Early Empire

Merkel Cell Polyomavirus Strains in Patients with Merkel Cell Carcinoma

We investigated whether Merkel cell carcinoma (MCC) patients in France carry Merkel cell polyomavirus (MCPyV) and then identified strain variations. All frozen MCC specimens and 45% of formalin-fixed and paraffin-embedded specimens, but none of the non-MCC neuroendocrine carcinomas specimens, had MCPyV. Strains from France and the United States were similar