Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector

Cosmic rays extensive air showers (EAS) are associated with transient radio emission, which could provide an efficient new detection method of high energy cosmic rays, combining a calorimetric measurement with a high duty cycle. The CODALEMA experiment, installed at the Radio Observatory in Nancay, France, is investigating this phenomenon in the 10^17 eV region. One challenging point is the understanding of the radio emission mechanism. A first observation indicating a linear relation between the electric field produced and the cross product of the shower axis with the geomagnetic field direction has been presented (B. Revenu, this conference). We will present here other strong evidences for this linear relationship, and some hints on its physical origin.Comment: Contribution to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009. 4 pages, 8 figures. v2: Typo fixed, arxiv references adde

Geomagnetic origin of the radio emission from cosmic ray induced air showers observed by CODALEMA

The new setup of the CODALEMA experiment installed at the Radio Observatory in Nancay, France, is described. It includes broadband active dipole antennas and an extended and upgraded particle detector array. The latter gives access to the air shower energy, allowing us to compute the efficiency of the radio array as a function of energy. We also observe a large asymmetry in counting rates between showers coming from the North and the South in spite of the symmetry of the detector. The observed asymmetry can be interpreted as a signature of the geomagnetic origin of the air shower radio emission. A simple linear dependence of the electric field with respect to vxB is used which reproduces the angular dependencies of the number of radio events and their electric polarity.Comment: 9 pages, 15 figures, 1 tabl

The new violet laser dye, Krome Orange, allows an optimal polychromatic immunophenotyping based on CD45-KO gating.

Item does not contain fulltextBACKGROUND: Polychromatic immunophenotyping improves characterization of leukocyte subpopulations and their malignant counterparts. However, the lack of various fluorochrome-labeled monoclonal antibodies (MoAbs) hinders the formation of multi-color panels. CD45 appears to be an important MoAb for immunophenotyping of these cells. Plotted against the side scatter, CD45 provides immunological cell differentiation and the ability to recognize various normal and malignant leukocyte subpopulations. CD45 is commonly used and labeled with various fluorochromes and as a result, is incorporated in multi-color panels as a conjugate of less available fluorochromes, such as the violet laser dyes. However, these dyes (e.g. Pacific Orange/PO) often possess low fluorescence intensity, which may be too weak to differentiate between populations. The new organic dye Krome Orange (KO, emission at 528 nm) appears to be a more intense violet laser dye, serving as an alternative to PO. METHODS: Intensities of CD45 conjugated with FITC, PE, ECD, PE-Cy5, PE-Cy7, PO and KO were tested in different cell sources. Various lineage markers were sequentially back gated on CD45-KO to identify subpopulations. A 10-color MoAb panel for determination of aberrancies in small cell samples was composed to test specificity of CD45-KO. CONCLUSIONS: We showed in various fixed and unfixed cells from different sources that KO is a suitable fluorochrome with a significantly higher quantum yield than PO and is even brighter than other violet laser dyes (e.g. Pacific Blue). CD45-KO/SS enables us to distinguish and characterize various normal and malignant leukocyte subpopulations. By using a 10-color MoAb panel to screen on aberrancies, we showed that CD45-KO provides reliable immunophenotyping within small amounts of cells and thereby improves the quality of 10-color stainings

The role of canalicular ABC transporters in cholestasis

Item does not contain fulltextCholestasis, a hallmark feature of hepatobiliary disease, is characterized by the retention of biliary constituents. Some of these constituents, such as bile acids, inflict damage to hepatocytes and bile duct cells. This damage may lead to inflammation, fibrosis, cirrhosis, and eventually carcinogenesis, sequelae that aggravate the underlying disease and deteriorate clinical outcome. Canalicular ATP-binding cassette (ABC) transporters, which mediate the excretion of individual bile constituents, play a key role in bile formation and cholestasis. The study of these transporters and their regulatory nuclear receptors has revolutionized our understanding of cholestatic disease. This knowledge has served as a template to develop novel treatment strategies, some of which are currently already undergoing phase III clinical trials. In this review we aim to provide an overview of the structure, function, and regulation of canalicular ABC transporters. In addition, we will focus on the role of these transporters in the pathogenesis and treatment of cholestatic bile duct and liver diseases

Picosecond time drift characterization of the Laser MegaJoule timing system

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