The CALICE Semi-Digital Hadronic Calorimeter (SDHCAL) prototype, built in 2011, was exposed to beams of hadrons, electrons and muons in two short periods in 2012 on two different beam lines of the CERN SPS. The prototype with its 48 active layers, made of Glass Resistive Plate Chambers and their embedded readout electronics, was run in triggerless and power-pulsing mode. The performance of the SDHCAL during the test beam was found to be very satisfactory with an efficiency exceeding 90% for almost all of the 48 active layers. A linear response (within ± 5%) and a good energy resolution are obtained for a large range of hadronic energies (5-80 GeV) by applying appropriate calibration coefficients to the collected data for both the Digital (Binary) and the Semi-Digital (Multi-threshold) modes of the SDHCAL prototype. The Semi-Digital mode shows better performance at energies exceeding 30 GeV.

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Proliferation of mesangial cells (MC) is an early event in many forms of glomerulonephritis. We have previously shown that platelet-derived growth factor (PDGF)-induced proliferation of MC was inhibited by the overexpression of cyclooxygenase-2 (COX-2). Since reactive oxygen species (ROS) are important mediators of mitogenic signaling, we evaluated the role of ROS in the COX-2 induced growth arrest in MC. We demonstrate that ROS are reduced in COX-2 overexpressing MC. Intracellular elevation of ROS restored PDGF-induced proliferation, while the expression of the cyclin-dependent kinase inhibitors p21 cip1 and p27 kip1 were decreased in these cells. The data suggest that COX-2 decreases ROS formation which consequently leads to the PDGF-induced inhibition of MC proliferation.

In special tests, the active layers of the CALICE Digital Hadron Calorimeter prototype, the DHCAL, were exposed to low energy particle beams, without being interleaved by absorber plates. The thickness of each layer corresponded approximately to 0.29 radiation lengths or 0.034 nuclear interaction lengths, defined mostly by the copper and steel skins of the detector cassettes. This paper reports on measurements performed with this device in the Fermilab test beam with positrons in the energy range of 1 to 10 GeV. The measurements are compared to simulations based on GEANT4 and a standalone program to emulate the detailed response of the active elements.