Particle bioturbation in Massachusetts Bay: Preliminary results using a new deliberate tracer technique

To better understand temporal and particle size-dependent bioturbation processes, we conducted a study of sediment mixing in Massachusetts Bay using a newly developed deliberate tracer technique. Sediments from a 32-m, fine-grained site were collected and the 38–62 (“silt”) and 63–125 (“sand”) μm fractions isolated. These particle-size fractions were labeled with two different noble metals (Au: silt & Ag: sand) using a thermal diffusion technique. Mixtures of the tracers were spread onto the seafloor in April and July 1992 by divers and were tube-cored (3 replicates) ˜ 80 d later in each case. Vertical profiles of the tracers were measured at μg/g (Ag) and ng/g (Au) levels by instrumental neutron activation analysis. During the spring experiment, Au (silt) was mixed to depths \u3e 15 cm and displayed multiple subsurface maxima, whereas Ag (sand) was confined to the upper 5 cm of the bed and showed a near monotonic decrease in concentration with depth. In the fall experiment, the tracers displayed more congruent down-core profiles consisting of near-surface maxima and several subsurface peaks. Two nonlocal bioturbation modes are suggested by the tracer data: reverse conveyor-belt transport and head-down deposit feeding or excavation. A particle caching strategy by an unidentified macrofaunal species is postulated to explain the subsurface peaks, but remains conjectural without better species-level natural history information regarding solid-phase bioturbation

Cytogenetic and Molecular Predictors of Outcome in Acute Lymphocytic Leukemia: Recent Developments

During the last decade a tremendous technologic progress based on genome-wide profiling of genetic aberrations, structural DNA alterations, and sequence variations has allowed a better understanding of the molecular basis of pediatric and adult B/T- acute lymphoblastic leukemia (ALL), contributing to a better recognition of the biological heterogeneity of ALL and to a more precise definition of risk factors. Importantly, these advances identified novel potential targets for therapeutic intervention. This review will be focused on the cytogenetic/molecular advances in pediatric and adult ALL based on recently published articles

Reduction des emissions polluantes et du CO_2 : etat des connaissances, etat des recherches dans le monde

Available from INIST (FR), Document Supply Service, under shelf-number : RP 400 (2335) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEAgence de l'Environnement et de la Maitrise de l'Energie (ADEME), 92 - Vanves (France)FRFranc

High Density Cell Microarray Based on Dielectrophoresis Traps Induced by a Matrix of Singularities

International audienc

Fast concentration gradient generator on a cell biochip for toxicology applications

International audienc

Les etudes de securite et de fiabilite Communication au seminaire OTAN/CDSM, Brest, 25-27 mars 1987

Communication se trouvant dans les actes du seminaire 'Evaluation du risque de pollution accidentelle liee au transport maritime de substances dangereuses' (p.165 a 199) organise par le Centre de documentation, de recherche et d'experimentations sur les pollutions accidentelles des eaux (CEDRE) a Brest, 25-27 mars 1987SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : RP 10404 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

A microfluidic device with removable packaging for the real time visualisation of intracellular effects of nanosecond electrical pulses on adherent cells

Dalmay, C De Menorval, M A Francais, O Mir, L M Le Pioufle, B England Lab on a chip Lab Chip. 2012 Oct 16;12(22):4709-15. doi: 10.1039/c2lc40857k.The biological mechanisms induced by the application of nanosecond pulsed electric fields (nsPEFs: high electrical field amplitude during very short duration) on cells remain partly misunderstood. In this context, there is an increasing need for tools that allow the delivering of such pulses with the possibility to monitor their effects in real-time. Thanks to miniaturization and technology capabilities, microtechnologies offer great potential to address this issue. We report here the design and fabrication of a microfluidic device optimized for the delivery of ultra short (10 ns) and intense (up to 280 kV cm(-1)) electrical pulses on adherent cells, and the real time monitoring of their intracellular effects. Ultra short electric field pulses (nsPEFs or nanopulses) affect both the cell membrane and the intracellular organelles of the cells. In particular, intracellular release of calcium from the endoplasmic reticulum was detected in real time using the device, after exposure of adherent cells to these nsPEFs. The high intensity and spatial homogeneity of the electric field could be achieved in the device thanks to the miniaturization and the use of thick (25 mum) electroplated electrodes, disposed on a quartz substrate whose transparency allowed real time monitoring of the nsPEFs effects. The proposed biochip is compatible with cell culture glass slides that can be placed on the chip after separate culture of several days prior to exposure. This device allows the easy exposure of almost any kind of attached cells and the monitoring in real time while exposed to nsPEFs, opening large possibilities for potential use of the developed biochips