Mesure de l'épaisseur des différentes couches de la paroi de l'intestin grêle du chien sain : corrélation entre histologie et échographie

Depuis l’utilisation de l’échographie en entérologie vétérinaire, il est admis de manière empirique que les mesures de la paroi intestinale à l’échographie correspondent aux mesures histologiques, sans qu’aucune étude n’en ait jamais vérifié la corrélation effective. Cette étude expérimentale a été menée sur 8 chiens Beagle sains afin de comparer des mesures sur images échographiques et stéréomicroscopiques prises dans différentes conditions et sur images histologiques du duodénum, du jéjunum et de l’iléon. Les résultats montrent que les mesures des tuniques pariétales de l’intestin grêle à l’échographie conventionnelle sont très proches de celles obtenues en stéréomicroscopie et en histologie. Il existe cependant des variations entre les trois portions intestinales et notamment l’iléon qui donne les résultats les moins satisfaisants. Il est donc pertinent d’utiliser l’échographie pour mesurer l’épaisseur des tuniques de la paroi de l’intestin grêle chez le chien

Secure migration of virtual SDN topologies

International audienceWith the emergence of Software Defined Networks (SDN), new virtualization techniques have appeared (e.g., FlowVi-sor [14]). Traditional hypervision has attracted a lot of attention with respect to resource sharing and multi-tenancy. Cloud providers have usually a solid knowledge on how to manage computing , memory and storage resources, but often lack the ability to properly manage network resources. Thanks to OpenFlow, a widespread SDN southbound interface protocol, virtualizing the network infrastructure has become possible. However, network virtualization also comes with its own security issues ([5], [6]). In this paper, we focus on the security aspects related to the migration of virtual networks. After providing a brief overview of the technological scope of our work, we review the state of the art of the migration of virtual resources. Finally, we conclude with our current results and the prospective outcomes we expect to obtain

Relationships Among Some Lolium and Festuca Species

Molecular markers were used to investigate phylogenetic relationships among the 8 species of ryegrass (Lolium) and 11 species of fescue (Festuca). Nine sequences of non-coding chloroplastic or mitochondrial DNA were amplified through PCR, then digested by 20 restriction enzymes. Restriction sites data were used to draw an UPGMA tree. The main features are: 1) a clear-cut distinction between fine-leaved fescues (subg. Festuca) and broad-leaved fescues (subg. Schedonorus), which include the ryegrasses. 2) among the broad-leaved fescues, meadow fescue and tall fescue are very closely related, which may indicate that they share a common maternal ancestor, while gigant fescue is the most differentiated. 3) in the ryegrass group, the endemic L. canariense and perennial ryegrass seem to have diverged first from their common ancestor with meadow fescue, while all the annual ryegrasses, both outbreeders or inbreeders, have a recent origin

A Model for Granular Texture with Steric Exclusion

We propose a new method to characterize the geometrical texture of a granular packing at the particle scale including the steric hindrance effect. This method is based on the assumption of a maximum disorder (entropy) compatible both with strain-induced anisotropy of the contact network and steric exclusions. We show that the predicted statistics for the local configurations is in a fairly agreement with our numerical data.Comment: 9 pages, 5 figure

Low-Cost Microfabrication Tool Box

Microsystems are key enabling technologies, with applications found in almost every industrial field, including in vitro diagnostic, energy harvesting, automotive, telecommunication, drug screening, etc. Microsystems, such as microsensors and actuators, are typically made up of components below 1000 microns in size that can be manufactured at low unit cost through mass-production. Yet, their development for commercial or educational purposes has typically been limited to specialized laboratories in upper-income countries due to the initial investment costs associated with the microfabrication equipment and processes. However, recent technological advances have enabled the development of low-cost microfabrication tools. In this paper, we describe a range of low-cost approaches and equipment (below £1000), developed or adapted and implemented in our laboratories. We describe processes including photolithography, micromilling, 3D printing, xurography and screen-printing used for the microfabrication of structural and functional materials. The processes that can be used to shape a range of materials with sub-millimetre feature sizes are demonstrated here in the context of lab-on-chips, but they can be adapted for other applications. We anticipate that this paper, which will enable researchers to build a low-cost microfabrication toolbox in a wide range of settings, will spark a new interest in microsystems

Optimizing resource allocation for secure SDN-based virtual network migration

International audienceRecent evolutions in cloud infrastructures allowed service providers to tailor new services for demanding customers. Providing these services confronts the infrastructure providers with costs and constraints considerations. In particular, security constraints are a major concern for today's businesses as the leak of personal information would tarnish their reputation. Recent works provide examples on how an attacker may leverage the infrastructure's weaknesses to steal sensitive information from the users. Specifically, an attacker can leverage maintenance processes inside the infrastructure to conduct an attack. In this paper, we consider the migration of a virtual network as the maintenance process. Then we determine the optimal monitoring resources allocation in this context with a Markov Decision Process. This model takes into account the impact of monitoring the infrastructure, the migration process and finally how the attacker may chose particular targets in the infrastructure. We provide a working prototype implemented in Python

The effect of mass loading on spurious modes in micro-resonators

Dissipation mechanisms severely compromise the performance of micro-resonator based sensors. In this letter, we specifically examine the shift in resonant frequency of spurious modes towards the mode of interest during mass loading. This can result in modal interaction that degrades the response of the sensor. However, by understanding and controlling this effect we can overcome this key barrier to micro-resonator applications.This is the author accepted manuscript. The final version is available from AIP via http://dx.doi.org/10.1063/1.492759

Microfluidics for protein biophysics

Microfluidics has the potential to transform experimental approaches across the life sciences. In this review, we discuss recent advances enabled by the development and application of microfluidic approaches to protein biophysics. We focus on areas where key fundamental features of microfluidics open up new possibilities and present advantages beyond low volumes and short time-scale analysis, conventionally provided by microfluidics. We discuss the two most commonly used forms of microfluidic technology, single-phase laminar flow and multiphase microfluidics. We explore how the understanding and control of the characteristic physical features of the microfluidic regime, the integration of microfluidics with orthogonal systems and the generation of well-defined microenvironments can be used to develop novel devices and methods in protein biophysics for sample manipulation, functional and structural studies, detection and material processing

Mechanism of droplet-formation in a supersonic microfluidic spray device

Spray drying is an approach employed in automotive, food, and pharmaceutical industries as a robust and cost efficient liquid atomization technique offering direct control over droplet dimensions. The majority of commercially available spray nozzles are designed for large throughput spray drying applications or uniform surface coating, but microfluidic nebulizers have recently been developed as small scale alternatives. Here, we explore the physical parameters that define the droplet size and formation under supersonic flow conditions commonly found in microfluidic spray drying systems. We examined the spray nozzle operation using high speed imaging and laser scattering measurements, which allowed us to describe the spray regimes and droplet size distributions. It was determined that by using this spray nozzle device, droplets with diameters of 4–8 μm could be generated. Moreover, we show that the supersonic de Laval nozzle model can be used to predict the average droplet size. Our approach can be used as a platform for interfacing fluid microprocessing with gas phase detection and characterization