208 research outputs found
Effects of Intrabeam Scattering and Synchrotron Radiation Damping when Reducing Transverse Emittances to Augment the LHC Luminosity
The effects of intrabeam scattering (IBS) and synchrotron radiation on the expected evolution of the LHC and SLHC beam emittances during physics coasts at 7 TeV are examined for the nominal beam and beams with reduced emittances
Time series analysis of Coulomb collisions in a beam dynamics simulation
Abstract In this paper, a time series analysis of collisional effects in a numerical simulation of a coasting beam transverse dynamics is presented. The simulation performs a numerical integration of the Hamilton's equations of a two-dimensional system of particles, describing the transverse dynamics of the beam. Then, an analysis of the time series generated has been applied in order to describe the dynamics of the system by means of the mean field equations, with the addition of a stochastic process in order to model Coulomb collisions
Comparing different approaches for generating random numbers device-independently using a photon pair source
What is the most efficient way to generate random numbers
device-independently using a photon pair source based on spontaneous parametric
down conversion (SPDC)? We consider this question by comparing two
implementations of a detection-loophole-free Bell test. In particular, we study
in detail a scenario where a heralded single photon source (HSPS) is used to
herald path-entangled states, i.e. entanglement between two spatial modes
sharing a single photon and where non-locality is revealed using photon
counting preceded by small displacement operations. We start by giving a
theoretical description of such a measurement. We then show how to optimize the
Bell-CHSH violation through a non-perturbative calculation, taking the main
experimental imperfections into account. We finally bound the amount of
randomness that can be extracted and compare it to the one obtained with the
conventional scenario using photon pairs entangled e.g. in polarization and
analyzed through photon counting. While the former requires higher overall
detection efficiencies, it is far more efficient in terms of both the entropy
per experimental run and the rate of random bit generation.Comment: 12 pages, 5 figure
Monetary Policy, Regulation and Volatile Markets
Turmoil in financial markets causes reflection. Is monetary policy conducted in the most efficient way? Are regulatory and supervisory arrangements adequate when market volatility increases and financial institutions come under stress? In the present SUERF Study, we have collected the reflections by an outstanding group of top officials, researchers and observers. The editors are proud to be able to present their joint insights to SUERF readers. The papers were presented at the 27th SUERF Colloquium in Munich in June 2008: New trends in asset management: Exploring the implications.Financial markets, volatility, regulatory and supervisory arrangements, LATW, bubbles, monetary policy, asset prices, interest rate policy, LTCM, Basel II, MiFID, subprime, CDOs
ERL Scheme for Compton Polarised Positron Sources
International audienceOne of the main challenges for the future linear colliders projects (ILC and CLIC) is to design an efficient positron source taking into account the constraints imposed by the target heating. At present, different schemes have been analysed to produce high energy gammas and to convert them in an amorphous target. One of them considers the possibility to boost the energy of the backscattered photons of a laser pulse by Compton effect. This method is very attractive since the source is independent from the main Linac and since the photon helicity is conserved in Compton scattering and subsequently transferred to the produced pairs. This allows the physics experiments disposing of both positron and electron polarised sources. Different schemes have been proposed to provide the electron beam for the Compton collisions. taking into account the constraint imposed by the low value of the Thomson cross section. One of the explored possibilities is to design an ERL with relatively low repetition frequency, high charge per pulse and then to stack the produced positrons in an accumulation ring. Different considerations on this scheme will be illustrated and the main constraints discussed. MO6RFP06
Targeting a phospho-STAT3-miRNAs pathway improves vesicular hepatic steatosis in an in vitro and in vivo model
Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease. Although genetic predisposition and epigenetic factors contribute to the development of NAFLD, our understanding of the molecular mechanism involved in the pathogenesis of the disease is still emerging. Here we investigated a possible role of a microRNAs-STAT3 pathway in the induction of hepatic steatosis. Differentiated HepaRG cells treated with the fatty acid sodium oleate (fatty dHepaRG) recapitulated features of liver vesicular steatosis and activated a cell-autonomous inflammatory response, inducing STAT3-Tyrosine-phosphorylation. With a genome-wide approach (Chromatin Immunoprecipitation Sequencing), many phospho-STAT3 binding sites were identified in fatty dHepaRG cells and several STAT3 and/or NAFLD-regulated microRNAs showed increased expression levels, including miR-21. Innovative CARS (Coherent Anti-Stokes Raman Scattering) microscopy revealed that chemical inhibition of STAT3 activity decreased lipid accumulation and deregulated STAT3-responsive microRNAs, including miR-21, in lipid overloaded dHepaRG cells. We were able to show in vivo that reducing phospho-STAT3-miR-21 levels in C57/BL6 mice liver, by long-term treatment with metformin, protected mice from aging-dependent hepatic vesicular steatosis. Our results identified a microRNAs-phosphoSTAT3 pathway involved in the development of hepatic steatosis, which may represent a molecular marker for both diagnosis and therapeutic targeting
Cyclooxygenase-2 inhibitors. 1,5-diarylpyrrol-3-acetic esters with enhanced inhibitory activity toward cyclooxygenase-2 and improved cyclooxygenase-2/cyclooxygenase-1 selectivity.
he important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3- acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain
Stacking Simulations for Compton Positron sources of Future Linear Colliders
The Compton positron source of a future linear collider must obtain the target bunch population by accumulating a large number of positron packets, arriving either in a number of bursts from a âCompton ringâ, with intermediate damping of the scattering electron beam, or quasicontinually from a âCompton energy recovery linacâ. We present simulation results for the longitudinal stacking of Compton positrons in the ILC damping ring (DR) and the CLIC pre-damping ring (PDR), discussing parameter optimization, stacking efficiency, possible further improvements, and outstanding questions
Factors Associated with SARS-CoV-2 Infection Evaluated by Antibody Response in a Sample of Workers from the Emilia-Romagna Region, Northern Italy
Factors associated with SARS-CoV-2 infection risk are still debated. This caseâcontrol study
aims to investigate the possible relationship between SARS-CoV-2 infection, evaluated through antibody response, and the main sociodemographic, occupational, clinical-anamnestic, and biochemical
factors in a population of Modena province (Northern Italy), mainly workers. Both workers who
voluntarily joined the screening campaign proposed by companies and self-referred individuals who
underwent serological testing were enrolled. Subjects with antibody positivity were recruited as
cases (n = 166) and subjects tested negative (n = 239) as controls. A questionnaire on sociodemographic, occupational, and clinical data was administered through telephone interviews. Serum
zinc/iron/copper/chromium/nickel, vitamins D/B12, folates, triglycerides, and LDL/HDL/total
cholesterol were measured. Cases lived more often in urban areas (61.8% vs. 57%). Cases and
controls did not differ significantly by working macrocategories, but the percentage of workers in the
ceramic sector was higher among cases. Low adherence to preventive measures in the workplace
was more frequent among seropositives. Folate concentration was significantly lower among cases.
Therefore, adequate folate levels, living in rural areas, and good adherence to preventive strategies
seem protective against infection. Workers in the ceramic sector seem to be at greater risk; specific
factors involved are not defined, but preventive interventions are needed
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