DNA degradation in avian faecal samples and feasibility of non-invasive genetic studies of threatened capercaillie populations

We evaluated the feasibility of using faeces as a non-invasively collected DNA source for the genetic study of an endangered bird population (capercaillie; Tetrao urogallus). We used a multitube approach, and for our panel of 11 microsatellites genotyping reliability was estimated at 98% with five repetitions. Experiments showed that free DNases in faecal material were the major cause of DNA degradation. Our results demonstrate that using avian faeces as a source of DNA, reliable microsatellite genotyping can be obtained with a reasonable number of PCR replicate

Coherent beam superposition of ten diode lasers with a Dammann grating

We demonstrate the use of a binary diffractive optical element in a very simple setup to convert the multilobed beam from a low fill factor array of coherent laser diodes into a quasi-Gaussian beam. The phase profile of the grating is determined with a phase retrieval algorithm. Experimentally, the conversion efficiency reaches more than 44%. We also establish that this setup can be used to make an effective measurement of the coherency of the laser array

Enabling Large-Scale Testing of IaaS Cloud Platforms on the Grid'5000 Testbed

International audienceAlmost ten years after its premises, the Grid'5000 platform has become one of the most complete testbeds for designing or evaluating large-scale distributed systems. Initially dedicated to the study of High Performance Computing, the infrastructure has evolved to address wider concerns related to Desktop Computing, the Internet of Services and more recently the Cloud Computing paradigm. In this paper, we present the latest mechanisms we designed to enable the automated deployment of the major open-source IaaS cloudkits (i.e., Nimbus, OpenNebula, CloudStack, and OpenStack) on Grid'5000. Providing automatic, isolated and reproducible deployments of cloud environments lets end-users study and compare each solution or simply leverage one of them to perform higher-level cloud experiments (such as investigating Map/Reduce frameworks or applications)

Semi-Automatic Classification of Cementitious Materials using Scanning Electron Microscope Images

International audienceSegmentation and classification are prolific research topics in the image processing community, which have been more and more used in the context of analysis of cementitious materials, on images acquired with Scanning Electron Microscopes (SEM). Indeed, there is a need to be able to detect and to quantify the materials present in a cement paste in order to follow the chemical reactions occurring in the material even days after the solidification. In this paper, we propose a new approach for segmentation and classification of cementitious materials based on the denoising of the data with the Block Matching 3D (BM3D) algorithm, Binary Partition Tree (BPT) segmentation, Support Vector Machines (SVM) classification, and the interactivity with the user. The BPT provides a hierarchical representation of the spatial regions of the data, allowing a segmentation to be selected among the admissible partitions of the image. SVMs are used to obtain a classification map of the image. This approach combines state-of-the-art image processing tools with the interactivity with the user to allow a better segmentation to be performed, or to help the classifier discriminate the classes better. We show that the proposed approach outperforms a previous method on synthetic data and several real datasets coming from cement samples, both qualitatively with visual examination and quantitatively with the comparison of experimental results with theoretical ones

gLite sur Grid'5000: vers une plate-forme d'expérimentation à taille réelle pour les grilles de production

National audienceThe Grid has become a huge and important instrument, playing a key role in the everyday work of many researchers. A large amount of software is being developed both to manage the grid infrastructure itself (gLite middleware), to facilitate the task of grid users (e.g workflow managers, pilot job managers, etc.), and to run the computations. That software must be designed to handle network and services outages in a highly distributed environment, while still providing the expected performance. It is inconvenient to test software using the production infrastructure, since (1) it might not exhibit the behaviour that is required to test extreme conditions (services are unlikely to crash as often as required when testing fault tolerance); (2) it might not be possible to replace key parts of the infrastructure without degrading the user experience; (3) experiments are not easily reproduced in production conditions. In this paper, we present our ongoing work on deploying the gLite middleware on the Grid'5000 testbed, a scientific instrument designed to support research on parallel, large-scale and distributed computing. Tools were written to automatize the deployment of the gLite middleware on several sites and clusters, resulting in a deployment of 5 sites and 8 clusters on 441 machines in less than an hour. This provides a solid basis for future experiments on the gLite middleware and on software that interact with the middleware