Energy reconstruction and calibration algorithms for the ATLAS electromagnetic calorimeter

The work of this thesis is devoted to the study, development and optimization of the algorithms of energy reconstruction and calibration for the electromagnetic calorimeter (EMC) of the ATLAS experiment, presently under installation and commissioning at the CERN Large Hadron Collider in Geneva (Switzerland). A deep study of the electrical characteristics of the detector and of the signals formation and propagation is conduced: an electrical model of the detector is developed and analyzed through simulations; a hardware model (mock-up) of a group of the EMC readout cells has been built, allowing the direct collection and properties study of the signals emerging from the EMC cells. We analyze the existing multiple-sampled signal reconstruction strategy, showing the need of an improvement in order to reach the advertised performances of the detector. The optimal filtering reconstruction technique is studied and implemented, taking into account the differences between the ionization and calibration waveforms as emerging from the mock-up analysis. A new calibration procedure that does not need any informations from the ionization signals as collected from the physics events in the EMC is proposed; its feasibility is investigated and discussed

Diphoton searches in ATLAS

International audienc

On the feasibility of predicting the ATLAS EM Calorimeter ionization signals using the Time Convolution Method at the LHC sampling rate

The Time Convolution Method was developed to extract the electrical parameters associated with the readout of ionization signals in the EM Calorimeter. It has been developed and was successfully used for the EMC calibration at the 2001/2002 H8 beam test. In this note we investigate the the feasibility of the method at lower sampling rate, down to and including the LHC run-time rate of 25 ns

Google, Facebook and what else? Measuring the hybridity of Italian journalists by their use of sources

The contemporary media systems present hybrid logics and features that imply an increasingly interdependence among actors, media and communication formats. The hybrid media system approach underlines that legacy news media and non-elite media actors construct flows of news through different media technologies and according to complex temporal structures. A media environment arises in which traditional distinctions between concepts like \u2018online\u2019 and \u2018offline\u2019, \u2018producer\u2019 and \u2018audience\u2019, \u2018citizens\u2019 and \u2018journalists\u2019 become blurred. The emphasis appears to be on change more than continuity, and on difference more than similarity. Although the hybrid media approach is appreciated by numerous contemporary media scholars, hybridity in media often remains an all-encompassing concept and few attempts have been made to measure it. This article assesses the level of hybridity by investigating journalists\u2019 uses of sources. It considers mainly journalists\u2019 use of sources by the medium for which they work (from newspapers to web or radio) and the kinds of news that they produce (hard or soft news, business/finance, tech/science). The contemporary media systems present hybrid logics and features that imply an increasingly interdependence among actors, media and communication formats. The hybrid media system approach underlines that legacy news media and non-elite media actors construct flows of news through different media technologies and according to complex temporal structures. A media environment arises in which traditional distinctions between concepts like \u2018online\u2019 and \u2018offline\u2019, \u2018producer\u2019 and \u2018audience\u2019, \u2018citizens\u2019 and \u2018journalists\u2019 become blurred. The emphasis appears to be on change more than continuity, and on difference more than similarity. Although the hybrid media approach is appreciated by numerous contemporary media scholars, hybridity in media often remains an all-encompassing concept and few attempts have been made to measure it. This article assesses the level of hybridity by investigating journalists\u2019 uses of sources. It considers mainly journalists\u2019 use of sources by the medium for which they work (from newspapers to web or radio) and the kinds of news that they produce (hard or soft news, business/finance, tech/science). The assumption is, therefore, that, within a homogeneously hybridized media system, journalists use the same sources regardless of the medium for which they work and the topics with which they deal. This objective is pursued by analysing the data collected via a survey conducted by means of structured interviews with a sample of 1424 Italian journalists between October and November 2016. The findings show that the analytical distinction among platforms for which journalists work still matters in terms of sources. Except for the use of Facebook and Google, journalists have still very defined paths to collect sources according to the medium they work for. The article has implications also for the literature on journalists\u2019 authority and expertis

Oxidative Stress and Redox Modulation Potential in Type 1 Diabetes

Redox reactions are imperative to preserving cellular metabolism yet must be strictly regulated. Imbalances between reactive oxygen species (ROS) and antioxidants can initiate oxidative stress, which without proper resolve, can manifest into disease. In type 1 diabetes (T1D), T-cell-mediated autoimmune destruction of pancreatic β-cells is secondary to the primary invasion of macrophages and dendritic cells (DCs) into the islets. Macrophages/DCs, however, are activated by intercellular ROS from resident pancreatic phagocytes and intracellular ROS formed after receptor-ligand interactions via redox-dependent transcription factors such as NF-κB. Activated macrophages/DCs ferry β-cell antigens specifically to pancreatic lymph nodes, where they trigger reactive T cells through synapse formation and secretion of proinflammatory cytokines and more ROS. ROS generation, therefore, is pivotal in formulating both innate and adaptive immune responses accountable for islet cell autoimmunity. The importance of ROS/oxidative stress as well as potential for redox modulation in the context of T1D will be discussed

Characterization of Building Thermal Energy Consumption at the Urban Scale

The ongoing urban transition toward decarbonized energy systems has raised the attention on local energy planning practices. Besides the multiple actors involved in the planning process, the complexity of the urban energy systems requires the elaboration of heterogeneous data. In such contest, the paper introduces and compares two GIS-based ethodologies for supporting the spatial characterization of the local residential built environment in terms of building distribution and space heating energy consumption. Starting from the assessment of residential consumption, a third method for the characterization of non-residential building thermal energy consumption is proposed. From a bottom-up perspective, in both residential models all the buildings are geo-referenced and clustered according to their thermo-physical characteristics. From a top-down perspective, energy balance data are used to calibrate the bottom-up results and to match the total building loads. The procedure, tested on the city of Turin as case study, allows assessing the energy use of buildings and to create urban energy maps. The energy spatial characterization of a territory is the basis for performing short and long-term scenarios analysis. Results of this method can be useful to: i. decision maker to understand the current state of the territorial energy consumption to identify critical energy intense areas; ii. citizens for visualising their energy consumption and iii. researchers for setting up the basis of further urban analysis

Overcoming Self-Reactivity Through Immunological and Metabolic Redox Modulation

The importance of reactive oxygen species (ROS) is illustrated by their crucial roles in immunology and disease pathologies. ROS can activate redox-dependent transcription factors, promoting a host of proinflammatory immune responses that are exacerbated during oxidative stress. The aim of this thesis is to determine how redox modulation impairs self-reactivity and aberrant inflammation in diabetes. Prevention of CD4+ TH1 T cell activation is critical for restricting autoreactive immune responses and maintaining pancreatic β cell integrity in type 1 diabetes. Moreover, decreasing the inflammatory milieu and subsequent complications is necessary for restoring insulin sensitivity in type 2 diabetes. Although current immunosuppressive therapies are invaluable for transplantations, small molecule inhibitors with low toxicity are necessary for stopping autoreactivity and treating inflammatory-driven metabolic diseases. We utilized a catalytic antioxidant (CA) in diabetogenic models based on previous work demonstrating that redox modulation promotes T cell hyporesponsivness and impairs innate cell cytokine secretion by blocking NF-κB activation. Additionally, CA sustains health of isolated islets, delays islet allograft rejection, and inhibits transfer of diabetes into young NOD.scid mice. First, the mechanisms behind CA-mediated CD4+ TH1 T cell hyporesponsivness were investigated in vitro and in vivo using diabetogenic murine experiments with a focus on the redox-dependent sheddase TACE and one of its substrate, LAG-3, a negative regulator of T cell activation. Ability to track type 1 diabetes progression through a serum biomarker, soluble LAG-3, was also assessed from both murine and human samples. Next, CA-mediated alteration(s) of immune cell metabolism was characterized. Effects on glycolysis and oxidative phosphorylation were assessed to determine additional mechanisms of regulation and where treatment efficiency wanes. Lastly, redox modulation was evaluated in treatment of high-fat diet-induced type 2 diabetes. Markers of inflammation and diabetic complications were measured to ascertain the severity of insulin resistance. Collectively, this work is a distinct contribution to the knowledge of CA treatment and its ability to 1) inhibit diabetogenic TH1 responses through regulation of a redox-dependent metalloprotease and subsequent cleavage of a negative T cell surface marker; 2) prevent self-reactivity through metabolic regulation; and 3) reduce inflammation and complications in high-fat diet-induced type 2 diabetes

2004 ATLAS Combined Testbeam : Computation and Validation of the Electronic Calibration Constants for the Electromagnetic Calorimeter

From July to November 2004, a full slice of the ATLAS barrel detector was studied in testbeam. A complete electromagnetic barrel module was used, read by the final electronics and operated by ATLAS TDAQ software. This note describes in details the electronic calibration procedure and the cell energy reconstruction: each step of the procedure and its associated software is explicitly described. The general calibration procedure is very similar to the one applied in previous barrel and endcap standalone testbeams. Emphasis is put on tools developed in the context of the combined testbeam which can be used for commissioning and operation of the calorimeters in ATLAS. Many validation studies were performed on each calibration constant. Previously unobserved effects such as the FEB temperature dependence of some constants were observed. Overall, the calibration performances are at the expected level

Current and historical genetic variability of native brown trout populations in a southern alpine ecosystem: implications for future management

The highly polymorphic taxon European brown trout (genus Salmo) has high phenotypic plasticity, displaying a complex pattern of morphological and life-history variation, contributing to taxonomic confusion. Three main mitochondrial lineages (Adriatic, Mediterranean, and marmoratus) developed during the Pleistocene climatic events in the southern Alpine ecosystem. Here, the natural distribution of native brown trout S. trutta is controversial, complicated by introductions of the Atlantic strain. By investigating museum vouchers, this study aimed to retrace the historical presence of brown trout in the southern Alpine ecosystem before the beginning of mass introductions, which occurred since the middle of the 19th century. By examining the combination of historical and current genetic variability, this study aims to depict the actual impact of introductions of the introduced strain, increasing knowledge and informing conservation strategies and future management plans. The molecular approaches selected were: (i) sequencing of the mitochondrial control region and (ii) genotyping of the nuclear gene LDH-C1*. Vouchers dated the presence of the native Adriatic strain since 1821, while current genetic variability showed the widespread signature of introgression, a consequence of several decades of introductions. Focused plans to preserve local lineages are urgently needed, including short-term solution to avoid complete pauperization of this ecosystem