On the electromagnetic energy resolution of Cherenkov-fiber calorimeters

Electromagnetic calorimeters which sample the Cherenkov radiation of shower particles in optical fibers operate in a markedly different manner from calorimeters which rely on the dE/dx of shower particles. The well-understood physics of electromagnetic shower development is applied to the case of Cherenkov-fiber calorimetry (also known as quartz fiber calorimetry) and the results of systematically performed studies are considered in detail to derive an understanding of the critical parameters involved in energy measurement using such calorimeters. A quantitative parameterization of Cherenkov-fiber calorimetry electromagnetic energy resolution is proposed and compared with existing experimental results

CMS Forward-Backward MSGC milestone

The CMS MF1 milestone was set in order to evaluate system aspects of the CMS forward-backward MSGC tracker, to check the design and feasibility of mass production and to set up assembly and test procedures. We describe the construction and the experience gained with the operation of a system of 38 MSGC detectors assembled in six multi-substrate detector modules corresponding to the geometry of the forward-backward MSGC tracker in CMS. These modules were equipped with MSGCs mounted side by side, forming a continuous detector surface of about 0.2 m2. Different designs were tried for these modules. The problems encountered are presented with the proposed solutions. Operation conditions for the 38 MSGCs are reported from an exposure to a muon beam at the CERN SPS. Gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with the detection efficiency, the spatial resolution, alignment and edge studies

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Cloning of B-1,3-glucanases expressed during Cichorium somatic embryogenesis

Three different β-1,3-glucanase cDNA fragments, CG1, CG2 and CG3, were obtained by RT-PCR from RNA isolated from Cichorium hybrid `474' leaf fragments cultured for 11 days under somatic embryogenesis-inducing conditions. When expressed in Escherichia coli the proteins encoded by the three cDNAs were recognized by antibodies raised against 38 kDa extracellular β-1,3-glucanases studied previously (Helleboid et al., Planta 205 (1998) 56–63). The CG2 and CG3 cDNAs may represent expressed alleles of one gene because their sequences showed a very high identity (98.5€and are only 70␒dentical with CG1. Southern blot analysis revealed the presence of 3–4 genes coding for β-1,3-glucanases in the Cichorium genome. Expression analysis of the genes corresponding to the three clones analysed by semi-quantitative RT-PCR indicated that CG1 mRNAs were only detectable in Cichorium hybrid `474' leaf fragments from day 3 of somatic embryogenesis induction, whereas CG2-CG3 mRNAs were already present in non-induced leaf tissue of both the embryogenic hybrid `474' and a non-embryogenic genotype. The level of CG1 mRNAs was particularly high when embryogenic cells were dividing to produce embryos, and when the amount of callose deposited in cell walls surrounding embryogenic cells and young embryos decreased. These results indicate that expression of the CG1 gene is correlated to the somatic embryogenesis process and that it encodes a 38 kDa β-1,3-glucanase protein that may be involved in the degradation of callose localized around embryogenic cells and young embryos. A full-length CG1 cDNA clone was obtained using 3′ and 5′ RACE-PCR, and its sequence revealed that it encodes a β-1,3-glucanase that is equally homologous to both class III and class IV plant β-1,3-glucanase

Molecular characterization of new selective peroxisome proliferator–activated receptor {gamma} modulators with angiotensin receptor blocking activity

Selective peroxisome proliferator–activated receptor (PPAR) {gamma} modulation is a new pharmacological approach that, based on selective receptor-cofactor interactions and target gene regulation, should result in potent insulin sensitization in the absence of PPAR{gamma}-mediated adverse effects. Here, we characterize two angiotensin receptor blockers (ARBs), telmisartan and irbesartan, as new selective PPAR modulators (SPPARMs). Analysis of PPAR{gamma} protein conformation using protease protection showed that telmisartan directly interacts with the receptor, producing a distinct conformational change compared with a glitazone. Glutathione S-transferase pull-down and fluorescence resonance energy transfer assays revealed selective cofactor binding by the ARBs compared with glitazones with an attenuated release of the nuclear receptor corepressor and absence of transcriptional intermediary factor 2 recruitment by ARBs. Consistently, selective cofactor binding resulted in differential gene expression profiles in adipocytes (ARB versus glitazone treated) assessed by oligo microarray analysis. Finally, telmisartan improved insulin sensitivity in diet-induced obese mice in the absence of weight gain. The present study identifies two ARBs as new SPPARMs. SPPARM activity by ARBs could retain the metabolic efficacy of PPAR{gamma} activation with reduction in adverse effects exerting in parallel AT1 receptor blockade. This may provide a new therapeutic option for better cardiovascular risk management in metabolic diseases and may initiate the development of new classes of drugs combining potent antihypertensive and antidiabetic actions

Molecular characterization of new selective peroxisome proliferator–activated receptor {gamma} modulators with angiotensin receptor blocking activity

Selective peroxisome proliferator–activated receptor (PPAR) {gamma} modulation is a new pharmacological approach that, based on selective receptor-cofactor interactions and target gene regulation, should result in potent insulin sensitization in the absence of PPAR{gamma}-mediated adverse effects. Here, we characterize two angiotensin receptor blockers (ARBs), telmisartan and irbesartan, as new selective PPAR modulators (SPPARMs). Analysis of PPAR{gamma} protein conformation using protease protection showed that telmisartan directly interacts with the receptor, producing a distinct conformational change compared with a glitazone. Glutathione S-transferase pull-down and fluorescence resonance energy transfer assays revealed selective cofactor binding by the ARBs compared with glitazones with an attenuated release of the nuclear receptor corepressor and absence of transcriptional intermediary factor 2 recruitment by ARBs. Consistently, selective cofactor binding resulted in differential gene expression profiles in adipocytes (ARB versus glitazone treated) assessed by oligo microarray analysis. Finally, telmisartan improved insulin sensitivity in diet-induced obese mice in the absence of weight gain. The present study identifies two ARBs as new SPPARMs. SPPARM activity by ARBs could retain the metabolic efficacy of PPAR{gamma} activation with reduction in adverse effects exerting in parallel AT1 receptor blockade. This may provide a new therapeutic option for better cardiovascular risk management in metabolic diseases and may initiate the development of new classes of drugs combining potent antihypertensive and antidiabetic actions

Dark Count Rate in Single-Photon Avalanche Diodes: characterization and modeling study

International audienceDark Count Rate (DCR) in Single-Photon Avalanche Diodes (SPAD) in Complementary Metal-Oxide Semiconductor technology is characterized and analyzed with a comprehensive simulation methodology. Based on a series of measurements of SPAD with various architectures, on an extended range of voltages and temperatures, the DCR measurements are correlated to the spatial localization of traps within the device and their parameters. To this aim, process and electrical simulations using Technology Computer-Aided Design (TCAD) tools are combined with an in-house McIntyre solver to compute the breakdown probability (Pt). The traps are accounted for using thermal SRH carrier generation-recombination mechanism which is coupled with the position-dependent breakdown probability. This rigorous methodology makes it possible to directly compare with DCR measurements, since only generated carriers with a non-negligible breakdown probability are considere