ATLAS Pixel Detector: Operational Experience and Run-1 to Run-2 Transition

The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long shutdown, the detector was extracted from the experiment and brought to surface, to equip it with new service quarter panels, to repair modules and to ease installation of a new innermost layer, the Insertable B-Layer (IBL). An overview of the operational experience, the refurbishing of the Pixel Detector and of the IBL project as well as the experience in its construction, integration and commissioning are described.Comment: presented at VERTEX 2014 - 23rd International Workshop on Vertex Detectors, Doksy, Czech Republic, 15 Sep 2014. PoS(Vertex2014)00

ATLAS IBL: a challenging first step for ATLAS Upgrade at the sLHC

With the LHC collecting data at 7 TeV, plans are already advancing for a series of upgrades leading eventually to about five times the LHC design luminosity some 10 years from now in the High Luminosity LHC (HL-LHC) project. The upgrades for ATLAS detector will be staged in preparation for HL-LHC. The first upgrade for the Pixel Detector will be the construction of a new pixel layer, which will be installed during the first shutdown of the LHC machine foreseen in 2013-14. The new detector, called the Insertable B-Layer (IBL) will be installed between the existing Pixel Detector and a new, smaller radius beam-pipe at the radius of 3.2 cm. The IBL will require the development of several new technologies to cope with increased radiation and pixel occupancy and also to improve the physics performance through reduction of the pixel size and more stringent material budget. Two different and promising Silicon sensor technologies (planar n-in-n and 3D) are currently under investigation for the IBL. An overview of the IBL module design and the qualification for these sensor technologies are presented in this proceeding. This proceeding also summarizes the improvements expected to the ATLAS detector at the HL-LHC.Comment: 4 pages, 2 figures, Proceeding of XXIst International Europhysics Conference on High Energy Physics (EPS-HEP 2011), Grenoble, 21-27 July 201

Optimization of thin n-in-p planar pixel modules for the ATLAS upgrade at HL-LHC

The ATLAS experiment will undergo around the year 2025 a replacement of the tracker system in view of the high luminosity phase of the LHC (HL-LHC) with a new 5-layer pixel system. Thin planar pixel sensors are promising candidates to instrument the innermost region of the new pixel system, thanks to the reduced contribution to the material budget and their high charge collection efficiency after irradiation. The sensors of 50-150 $\mu$m thickness, interconnected to FE-I4 read-out chips, have been characterized with radioactive sources and beam tests. In particular active edge sensors have been investigated. The performance of two different versions of edge designs are compared: the first with a bias ring, and the second one where only a floating guard ring has been implemented. The hit efficiency at the edge has also been studied after irradiation at a fluence of $10^{15}$ \neqcm. Highly segmented sensors will represent a challenge for the tracking in the forward region of the pixel system at HL-LHC. In order to reproduce the performance of 50x50 $\mu$m$^2$ pixels at high pseudo-rapidity values, FE-I4 compatible planar pixel sensors have been studied before and after irradiation in beam tests at high incidence angles with respect to the short pixel direction. Results on the hit efficiency in this configuration are discussed for different sensor thicknesses

Performance of irradiated thin n-in-p planar pixel sensors for the ATLAS Inner Tracker upgrade

The ATLAS collaboration will replace its tracking detector with new all silicon pixel and strip systems. This will allow to cope with the higher radiation and occupancy levels expected after the 5-fold increase in the luminosity of the LHC accelerator complex (HL-LHC). In the new tracking detector (ITk) pixel modules with increased granularity will implement to maintain the occupancy with a higher track density. In addition, both sensors and read-out chips composing the hybrid modules will be produced employing more radiation hard technologies with respect to the present pixel detector. Due to their outstanding performance in terms of radiation hardness, thin n-in-p sensors are promising candidates to instrument a section of the new pixel system. Recently produced and developed sensors of new designs will be presented. To test the sensors before interconnection to chips, a punch-through biasing structure has been implemented. Its design has been optimized to decrease the possible tracking efficiency losses observed. After irradiation, they were caused by the punch-through biasing structure. A sensor compatible with the ATLAS FE-I4 chip with a pixel size of 50x250 $\mathrm{\mu}$m$^{2}$, subdivided into smaller pixel implants of 30x30 $\mathrm{\mu}$m$^{2}$ size was designed to investigate the performance of the 50x50 $\mathrm{\mu}$m$^{2}$ pixel cells foreseen for the HL-LHC. Results on sensor performance of 50x250 and 50x50 $\mathrm{\mu}$m$^{2}$ pixel cells in terms of efficiency, charge collection and electric field properties are obtained with beam tests and the Transient Current Technique

Amaurodon mustialaënsis (Basidiomycota, Thelephoraceae) new to Italy

Amaurodon mustialaënsis is reported for the first time from Italy. Based on Italian specimens, a brief description, microscopical and macroscopical photographs, ecological and distributional data of this rare taxon are presented.

c-MYC amplification and c-myc protein expression in pancreatic acinar cell carcinomas. New insights into the molecular signature of these rare cancers.

The molecular alterations of pancreatic acinar cell carcinomas (ACCs) and mixed acinar-neuroendocrine carcinomas (MANECs) are not completely understood, and the possible role of c-MYC amplification in tumor development, progression, and prognosis is not known. We have investigated c-MYC gene amplification in a series of 35 ACCs and 4 MANECs to evaluate its frequency and a possible prognostic role. Gene amplification was investigated using interphasic fluorescence in situ hybridization analysis simultaneously hybridizing c-MYC and the centromere of chromosome 8 probes. Protein expression was immunohistochemically investigated using a specific monoclonal anti-c-myc antibody. Twenty cases had clones with different polysomies of chromosome 8 in absence of c-MYC amplification, and 5 cases had one amplified clone and other clones with chromosome 8 polysomy, while the remaining 14 cases were diploid for chromosome 8 and lacked c-MYC amplification. All MANECs showed c-MYC amplification and/or polysomy which were observed in 54% pure ACCs. Six cases (15.3%) showed nuclear immunoreactivity for c-myc, but only 4/39 cases showed simultaneous c-MYC amplification/polysomy and nuclear protein expression. c-myc immunoreactivity as well as c-MYC amplification and/or chromosome 8 polysomy was not statistically associated with prognosis. Our study demonstrates that a subset of ACCs shows c-MYC alterations including gene amplification and chromosome 8 polysomy. Although they are not associated with a different prognostic signature, the fact that these alterations are present in all MANECs suggests a role in the acinar-neuroendocrine differentiation possibly involved in the pathogenesis of MANECs

IL-1β maintains the DNA hypermethylation of anti-inflammatory IL-10 gene in a human intestinal epithelial cell line

Intestinal inflammation is a natural process crucial to maintain gut integrity, but its deregulation is involved in the pathogenesis of severe intestinal disorders[1]. Intestinal epithelial cells play a crucial role in the inflammatory response, modulating the immune cell exposure to antigens and by their ability to secrete many inflammatory mediators. IL-1β represents a pivotal player: secreted by infiltrated leucocytes, it induces the expression of several pro-inflammatory genes. Also the anti-inflammatory IL-10, whose function is to terminate the inflammatory process, modulates the intestinal physiology[2]. Recent clinical reports showed that patients with ulcerative colitis in remission phase have significantly higher IL10 gene expression in mucosa compared with active patients and controls[3]. Moreover, in the latest years aberrant epigenetic mechanisms were put in binomial relationship with chronic inflammatory diseases[4]. Previously, we described a demethylation of pro-inflammatory IL6 and IL8 genes in human colonic Caco-2 cells differentiated into an enterocyte-like phenotype and exposed to the inflammatory action of IL-1β[5]. In the present study we evaluate whether the IL-1β treatment affected the methylation status of the anti-inflammatory IL10 gene, in the same in vitro model. Our results showed that IL-1β treatment did not change the hypermethylation status of the IL10 promoter. Moreover, in cell lysates from IL-1β-treated Caco-2 cells, we observed a dose-dependent increase of DNMTs activity and, surprisingly, a decrease of DNMT3b expression. These findings put in evidence the complexity of relationship between IL-1β and DNMTs, and may suggest a potential role of IL-1β as pleiotropic modulator of DNA methylation in Caco-2 cell line

Finite element analysis of ground deformation due to dike intrusion with applications to Mt. Etna volcano

A 2D finite elements study was carried out to analyse the effects caused by dike intrusion inside a heterogeneous medium and with a realistic topography of Mt. Etna volcano. Firstly, the method (dimension domain, elements type) was calibrated using plane strain models in elastic half-spaces; the results were compared with those obtained from analytical dislocation models. Then the effects caused both by the topographic variations and the presence of multi-layered medium on the surface, were studied. In particular, an application was then considered to Mt. Etna by taking into account the real topography and the stratification deduced from seismic tomography. In these conditions, the effects expected by the dike, employed to model the 2001 eruption under simple elastic half-space medium conditions, were computed, showing that topography is extremely important, at least in the near field