{WAVA}: a New Web Service for Automatic Video Data Flow Adaptation in Heterogeneous Collaborative Environments

International audienceThe progressive needs for using video streaming for different applications in varied domains have created a new set of heterogeneous environments. In order to get the best performance of such environments, video streaming has to be adapted to the different parameters that characterize these environments, namely: bandwidth, CPU, GPU, screen resolution, etc. In this paper, we define a new web service, named Wava (Web service for Automatic Video Data Flows Adaptation). Wava allows multimedia platform to adjust the adaptation at two levels: the static level during initialization and the dynamic level according to the fluctuation of the environment

Superconducting magnesium diboride films on Silicon with Tc0 about 24K grown via vacuum annealing from stoichiometric precursors

Superconducting magnesium diboride films with Tc0 ~ 24 K and sharp transition \~ 1 K were successfully prepared on silicon substrates by pulsed laser deposition from a stoichiometric MgB2 target. Contrary to previous reports, anneals at 630 degree and a background of 2x10^(-4) torr Ar/4%H2 were performed without the requirement of Mg vapor or an Mg cap layer. This integration of superconducting MgB2 films on silicon may thus prove enabling in superconductor-semiconductor device applications. Images of surface morphology and cross-section profiles by scanning electron microscopy (SEM) show that the films have a uniform surface morphology and thickness. Energy dispersive spectroscopy (EDS) reveals these films were contaminated with oxygen, originating either from the growth environment or from sample exposure to air. The oxygen contamination may account for the low Tc for those in-situ annealed films, while the use of Si as the substrate does not result in a decrease in Tc as compared to other substrates.Comment: 5 pages, 4 figures, 15 references; due to file size limit, images were blure

Cloning and sequence analysis of the defective in anther dehiscence1 (DAD1) gene fragment of Chinese kale

To clone the defective in anther dehiscence1 (DAD1) gene fragment of Chinese kale, about 700 bp product was obtained by PCR amplification using Chinese kale genomic DNA as the template and a pair of specific primers designed according to the conserved sequence of DAD1 genes of Arabidopsis thaliana and Brassica rapa. The amplified product was ligated into the T vector and sequenced. The results show that the gene fragment was 678 bp long without introns. It shared 89% identity with the nucleotide sequence of the DAD1 gene of A. thaliana and the sequence identity was as high as 97 to 99% with those of other plants belonging to the same genus as Chinese kale. The amino acid sequence deduced from the nucleotide sequence had 91% identity with that of A. thaliana. It was shown that the cloned fragment was a part of Chinese kale DAD1 gene.Key words: Chinese kale, Brassica oleracea var. alboglabra, defective in anther dehiscence1 (DAD1), gene clone

Statistical experimental methods for optimizing the cultivating conditions for Rhodococcus erythropolis

Rhodococcus erythropolis was found to effectively degrade aflatoxin Bl produced by Aspergillus flavus and Aspergillus parasiticus. However, one problem of concern was the slow growth of this strain. In this study, Plackett–Burman design was used to select the most important variables, namely, temperature, pH, inoculum size, liquid volume, agitation speed and culture time that affected the growth of R. erythropolis. Central composite experimental design and response surface analysis were adopted to derive a statistical model for optimizing the culture conditions. From the obtained results, it can be concluded that the optimum parameters were: temperature, 15.3°C; pH, 5.56; inoculum size, 4%; liquid volume, 70 ml in 250 ml flask; agitation speed, 180 rpm; and culture time, 58.2 h. At this optimum point, the populations of the viable organisms could reach 108 colony forming units (CFU)/ml, which was 100 times higher than that incubated under the initial conditions. After 58.2 h incubation in this optimum cultivating conditions, 53.9 ± 2.1% of aflatoxin B1 was degraded, while only 20.6±1.4% of aflatoxin B1 was degraded in the initial conditions.Key words: Rhodococcus erythropolis, culture condition, optimization, Plackett–Burman design, central composite design, response surface methodology

Superconducting gap structure and pinning in disordered MgB2 films

We have performed a comparative study of two thin films of magnesium diboride (MgB2) grown by different techniques. The critical current density at different temperatures and magnetic fields was evaluated from magnetisation curves, the structure of superconducting order parameter was obtained from point-contact spectroscopy, and the scattering rates were evaluated by fitting the temperature dependent normal-state resistivity to the two-band model. The films have similar critical temperatures close to 39 K, but the upper critical fields were different by a factor of 2 (5.2T and 2.5 T at 20 K). We have found that the film with higher Hc2 also had stronger scattering in the sigma band and smaller value of the superconducting gap in this band. As the scattering in sigma band is primarily due to the defects in boron plane, our results are consistent with the assumption that disordering the boron planes leads to enhanced Hc2 and better pinning properties in magnetic field.Comment: Paper presented at EUCAS'0

3-d Lattice QCD Free Energy to Four Loops

We compute the expansion of the 3-d Lattice QCD free energy to four loop order by means of Numerical Stochastic Perturbation Theory. The first and second order are already known and are correctly reproduced. The third and fourth order coefficients are new results. The known logarithmic divergence in the fourth order is correctly identified. We comment on the relevance of our computation in the context of dimensionally reduced finite temperature QCD.Comment: 8 pages, 3 figures, latex typeset with JHEP3.cl

Branching ratios for the beta decay of 21Na

We have measured the beta-decay branching ratio for the transition from 21Na to the first excited state of 21Ne. A recently published test of the standard model, which was based on a measurement of the beta-nu correlation in the decay of 21Na, depended on this branching ratio. However, until now only relatively imprecise (and, in some cases, contradictory) values existed for it. Our new result, 4.74(4)%, reduces but does not remove the reported discrepancy with the standard model.Comment: Revtex4, 2 fig

Packetization schemes for forward error correction in Internet video streaming

In this work, our focus is on video streaming applications with relatively strict delay constraints; for such applications, forward error correction (FEC) is the preferred channel coding technique to recover from packet losses. Moreover, since video packets are usually of different importance, optimal bit allocation across video packets results in different packets receiving unequal error protection (UEP)