Turbulence in a toroidal magnetized plasma investigated by collective light scattering: plasma form factor and plasma diffusion

12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France)On the toroidal magnetized plasma discharge ToriX, a collective light scattering device has been set to investigate plasma turbulence and transport. The light scattering intensity provides a measurement of the static form factor, at the scale of the scattering wave number k. The form factor is found to be very large, five to eight orders of magnitude above the equilibrium level. As a function of the k wave number, an exponential decay is found instead of a scaling law. This implies long range spatial correlation. The scattered light frequency spectral line shape is compared to the frequency Doppler transform (omega = k . v) of the plasma velocity in the observed volume. This is investigated by using both the classical Langmuir probes technique and the superheterodyne detection of the scattered light. The line shape is found to be mainly due to the non uniform convection velocity. To minimize the large scale convection velocity along the large radius, we added a vertical field to the horizontal toroidal B field. A significant decay of the form factor intensity is also observed. In this convection regulated regime, the scattered line profile modification as a function of k is investigated. It is interpreted as an effect of a brownian type of turbulent motion. According to this model, the signal auto-correlation function is expected to be the Ornstein function: C(t)=A exp{-k^2 D tc (t/tc -1 + exp(-t/tc))}, where tc is the correlation time of turbulent mouvement and D is the turbulent diffusion coefficient [1]. From this interpretation, the turbulent diffusion coefficient D across B is obtained for different plasma and observation conditions. As a function of the toroidal field intensity, D shows a characteristic Bohm behavior. These detailed investigations of the collective light scattering line profile validate the use of scattering device to get quantified measurements about plasma turbulent motion

Goulphar: rapid access and expertise for standard two-color microarray normalization methods

BACKGROUND: Raw data normalization is a critical step in microarray data analysis because it directly affects data interpretation. Most of the normalization methods currently used are included in the R/BioConductor packages but it is often difficult to identify the most appropriate method. Furthermore, the use of R commands for functions and graphics can introduce mistakes that are difficult to trace. We present here a script written in R that provides a flexible means of access to and monitoring of data normalization for two-color microarrays. This script combines the power of BioConductor and R analysis functions and reduces the amount of R programming required. RESULTS: Goulphar was developed in and runs using the R language and environment. It combines and extends functions found in BioConductor packages (limma and marray) to correct for dye biases and spatial artifacts. Goulphar provides a wide range of optional and customizable filters for excluding incorrect signals during the pre-processing step. It displays informative output plots, enabling the user to monitor the normalization process, and helps adapt the normalization method appropriately to the data. All these analyses and graphical outputs are presented in a single PDF report. CONCLUSION: Goulphar provides simple, rapid access to the power of the R/BioConductor statistical analysis packages, with precise control and visualization of the results obtained. Complete documentation, examples and online forms for setting script parameters are available from

A Vision-based Computed Torque Control for Parallel Kinematic Machines

In this paper, a novel approach for parallel kinematic machine control relying on a fast exteroceptive measure is implemented and validated on the Orthoglide robot. This approach begins with rewriting the robot models as a function of the only end-effector pose. It is shown that such an operation reduces the model complexity. Then, this approach uses a classical Cartesian space computed torque control with a fast exteroceptive measure, reducing the control schemes complexity. Simulation results are given to show the expected performance improvements and experiments prove the practical feasibility of the approach

Amplicon rearrangements during the extrachromosomal and intrachromosomal amplification process in a glioma

International audienceThe mechanisms of gene amplification in tumour cells are poorly understood and the relationship between extrachromosomal DNA molecules, named double minutes (dmins), and intrachromosomal homogeneously staining regions (hsr) is not documented at nucleotide resolution. Using fluorescent in situ hybridization and whole genome sequencing, we studied a xenografted human oligodendroglioma where the co-amplification of the EGFR and MYC loci was present in the form of dmins at early passages and of an hsr at later passages. The amplified regions underwent multiple rearrangements and deletions during the formation of the dmins and their transformation into hsr. In both forms of amplification, non-homologous end-joining and microhomology-mediated end-joining rather than replication repair mechanisms prevailed in fusions. Small fragments, some of a few tens of base pairs, were associated in contigs. They came from clusters of breakpoints localized hundreds of kilobases apart in the amplified regions. The characteristics of some pairs of junctions suggest that at least some fragments were not fused randomly but could result from the concomi-tant repair of neighbouring breakpoints during the interaction of remote DNA sequences. This characterization at nucleotide resolution of the transition between extra-and intrachromosome amplifications highlights a hitherto uncharacterized organization of the amplified regions suggesting the involvement of new mechanisms in their formation

A proteinaceous organic matrix regulates carbonate mineral production in the marine teleost intestine

Marine teleost fish produce CaCO(3) in their intestine as part of their osmoregulatory strategy. This precipitation is critical for rehydration and survival of the largest vertebrate group on earth, yet the molecular mechanisms that regulate this reaction are unknown. Here, we isolate and characterize an organic matrix associated with the intestinal precipitates produced by Gulf toadfish (Opsanus beta). Toadfish precipitates were purified using two different methods, and the associated organic matrix was extracted. Greater than 150 proteins were identified in the isolated matrix by mass spectrometry and subsequent database searching using an O. beta transcriptomic sequence library produced here. Many of the identified proteins were enriched in the matrix compared to the intestinal fluid, and three showed no substantial homology to any previously characterized protein in the NCBI database. To test the functionality of the isolated matrix, a micro-modified in vitro calcification assay was designed, which revealed that low concentrations of isolated matrix substantially promoted CaCO(3) production, where high concentrations showed an inhibitory effect. High concentrations of matrix also decreased the incorporation of magnesium into the forming mineral, potentially providing an explanation for the variability in magnesium content observed in precipitates produced by different fish species

Transcriptomic and proteomic profiles of vascular cells involved in human abdominal aortic aneurysm

Diseases & disorder

Onset of a submarine eruption east of Mayotte, Comoros archipelago: the first ten months seismicity of the seismo-volcanic sequence (2018–2019)

International audienceFrom 10 May 2018 to 1 November 2022 (time of writing), an unprecedented seismic activity is observed east of Mayotte Island (France), related to the largest submarine eruption ever recorded with offshore geophysical studies. Using signals from regional and local seismic stations, we build a comprehensive catalog of the local seismicity for the first ten months of the sequence. This catalog includes a total of 2874 events of magnitude (Mlv) ranging from 2.4 to 6.0, with 77% of them relocated using a double difference location procedure. The hypocentral locations over this period are highly dependent on the small seismic network available. Therefore we compare the locations of later events using a similar network and those estimated from a local ocean bottom seismometer (OBS) network installed since March 2019. Based on the time space evolution and characteristics of the seismicity, five distinct phases can be identified, corresponding to the successive activation of two deep seismic swarms, related to the lithospheric-scale magma ascent up to the seafloor, along with progressive deepening of the seismicity interpreted as decompression of a 40 km deep reservoir

CSRP3 mediates polyphenols-induced cardioprotection in hypertension

Berries contain bioactive polyphenols, whose capacity to prevent cardiovascular diseases has been established recently in animal models as well in human clinical trials. However, cellular processes and molecular targets of berries polyphenols remain to be identified. The capacity of a polyphenol-enriched diet (i.e., blueberries, blackberries, raspberries, strawberry tree fruits and Portuguese crowberries berries mixture) to promote animal survival and protect cardiovascular function from salt-induced hypertension was evaluated in a chronic salt-sensitive Dahl rat model. The daily consumption of berries improved survival of Dahl/salt-sensitive rats submitted to high-salt diet and normalized their body weight, renal function and blood pressure. In addition, a prophylactic effect was observed at the level of cardiac hypertrophy and dysfunction, tissue cohesion and cardiomyocyte hypertrophy. Berries also protected the aorta from fibrosis and modulated the expression of aquaporin-1, a channel involved in endothelial water and nitric oxide permeability. Left ventricle proteomics analysis led to the identification of berries and salt metabolites targets, including cystein and glycin-rich protein 3 (CSRP3), a protein involved in myocyte cytoarchitecture. In neonatal rat ventricular cardiomyocytes, CSRP3 was validated as a target of a berries-derived polyphenol metabolite, 4-methylcatechol sulfate, at micromolar concentrations, mimicking physiological conditions of human plasma circulation. Accordingly, siRNA silencing of CSRP3 and 4-methylcatechol sulfate pretreatment reversed cardiomyocyte hypertrophy and CSRP3 overexpression induced by phenylephrine. Our systemic study clearly supports the modulation of CSRP3 by a polyphenol-rich berries diet as an efficient cardioprotective strategy in hypertension-induced heart failure