1,233 research outputs found
RunDec: a Mathematica package for running and decoupling of the strong coupling and quark masses
In this paper the formulae are collected which are needed for the computation
of the strong coupling constant and quark masses at different energy scales and
for different number of active flavours. All equations contain the
state-of-the-art QCD corrections up to three- and sometimes even four-loop
order. For the practical implementation {\tt Mathematica} is used and a package
containing useful procedures is provided.Comment: 32 pages, ps figures included, accepted for publication in Computer
Physics Communication
A Smart Robotic System for Industrial Plant Supervision
In today's chemical plants, human field operators perform frequent integrity
checks to guarantee high safety standards, and thus are possibly the first to
encounter dangerous operating conditions. To alleviate their task, we present a
system consisting of an autonomously navigating robot integrated with various
sensors and intelligent data processing. It is able to detect methane leaks and
estimate its flow rate, detect more general gas anomalies, recognize oil films,
localize sound sources and detect failure cases, map the environment in 3D, and
navigate autonomously, employing recognition and avoidance of dynamic
obstacles. We evaluate our system at a wastewater facility in full working
conditions. Our results demonstrate that the system is able to robustly
navigate the plant and provide useful information about critical operating
conditions.Comment: Final submission for IEEE Sensors 202
Axial U(1) dynamics in eta and eta' photoproduction
We discuss the sensitivity of eta and eta' photoproduction near threshold to
the gluonic OZI breaking parameters in the U_A(1)-extended effective chiral
Lagrangian for low-energy QCD. Our coupled-channels analysis hints at a strong
correlation between the gluon-induced contributions to the eta' mass and the
low-energy pp -> pp eta' reaction and the near-threshold behaviour of the gamma
p -> eta p cross-section.Comment: 19 pages, 9 figure
Toxoplasma gondii Actively Inhibits Neuronal Function in Chronically Infected Mice
Upon infection with the obligate intracellular parasite Toxoplasma gondii, fast replicating tachyzoites infect a broad spectrum of host cells including neurons. Under the pressure of the immune response, tachyzoites convert into slow-replicating bradyzoites, which persist as cysts in neurons. Currently, it is unclear whether T. gondii alters the functional activity of neurons, which may contribute to altered behaviour of T. gondii–infected mice and men. In the present study we demonstrate that upon oral infection with T. gondii cysts, chronically infected BALB/c mice lost over time their natural fear against cat urine which was paralleled by the persistence of the parasite in brain regions affecting behaviour and odor perception. Detailed immunohistochemistry showed that in infected neurons not only parasitic cysts but also the host cell cytoplasm and some axons stained positive for Toxoplasma antigen suggesting that parasitic proteins might directly interfere with neuronal function. In fact, in vitro live cell calcium (Ca2+) imaging studies revealed that tachyzoites actively manipulated Ca2+ signalling upon glutamate stimulation leading either to hyper- or hypo-responsive neurons. Experiments with the endoplasmatic reticulum Ca2+ uptake inhibitor thapsigargin indicate that tachyzoites deplete Ca2+ stores in the endoplasmatic reticulum. Furthermore in vivo studies revealed that the activity-dependent uptake of the potassium analogue thallium was reduced in cyst harbouring neurons indicating their functional impairment. The percentage of non-functional neurons increased over time In conclusion, both bradyzoites and tachyzoites functionally silence infected neurons, which may significantly contribute to the altered behaviour of the host
Liver Fibrosis and Metabolic Alterations in Adults With alpha-1-antitrypsin Deficiency Caused by the Pi*ZZ Mutation
BACKGROUND & AIMS: Alpha-1 antitrypsin deficiency (AATD) is among the most common genetic disorders. Severe AATD is caused by a homozygous mutation in the SERPINA1 gene that encodes the Glu342Lys substitution (called the Pi*Z mutation,
Pi*ZZ genotype). Pi*ZZ carriers may develop lung and liver diseases. Mutation- associated lung disorders have been well studied, but less is known about the effects in liver. We assessed the liver disease burden and associated features in
adults with this form of AATD. METHODS: We collected data from 554 Pi*ZZ adults (403 in an exploratory cohort, 151 in a confirmatory cohort), in 9 European countries, with AATD who were homozygous for the Pi*Z mutation, and 234 adults without
the Pi*Z mutation (controls), all without pre-existing liver disease. We collected data on demographic parameters, comorbidities, lung- and liver-related health, and blood samples for laboratory analysis. Liver fibrosis was assessed non-invasively
via the serum tests Aspartate Aminotransferase to Platelet Ratio Index and HepaScore and via transient elastography. Liver steatosis was determined via transient elastography-based controlled attenuation parameter. We performed histologic
analyses of livers from transgenic mice that overexpress the AATD-associated Pi*Z variant. RESULTS: Serum levels of liver enzymes were significantly higher in Pi*ZZ carriers vs controls. Based on non-invasive tests for liver fibrosis, significant fibrosis
was suspected in 20%–36% of Pi*ZZ carriers, whereas signs of advanced fibrosis were 9- to 20-fold more common in Pi*ZZ carriers compared to non-carriers. Male sex; age older than 50 years; increased levels of alanine aminotransferase, aspartate
aminotransferase, or g-glutamyl transferase; and low numbers of platelets were associated with higher liver fibrosis burden. We did not find evidence for a relationship between lung function and liver fibrosis. Controlled attenuation parameter 280 dB/m, suggesting severe steatosis, was detected in 39% of Pi*ZZ carriers vs 31% of controls. Carriers of Pi*ZZ had lower serum concentrations of triglyceride and low- and very-lowdensity lipoprotein cholesterol than controls, suggesting impaired hepatic secretion of lipid. Livers from Pi*Zoverexpressing mice had steatosis and down-regulation of
genes involved in lipid secretion. CONCLUSIONS: In studies of AATD adults with the Pi*ZZ mutation, and of Pi*Z-overexpressing mice, we found evidence of liver steatosisinfo:eu-repo/semantics/publishedVersio
Results and Techniques of Multi-Loop Calculations
In this review some recent multi-loop results obtained in the framework of
perturbative Quantum Chromodynamics (QCD) and Quantum Electrodynamics (QED) are
discussed. After reviewing the most advanced techniques used for the
computation of renormalization group functions, we consider the decoupling of
heavy quarks. In particular, an effective method for the evaluation of the
decoupling constants is presented and explicit results are given. Furthermore
the connection to observables involving a scalar Higgs boson is worked out in
detail. We review the radiative corrections of a Higgs boson into gluons and
quarks and present explicit results up to order and ,
respectively. In this review special emphasis is put on the applications of
asymptotic expansions. A method is described which combines expansion terms of
different kinematical regions with the help of conformal mapping and Pad\'e
approximation. This method allows us to proceed beyond the present scope of
exact multi-loop calculations. As far as physical processes are concerned, we
review the computation of three-loop current correlators in QCD taking into
account the full mass-dependence. In a further application four-loop diagrams
are considered which contribute to the order QED corrections to the
decay. Finally the calculation of the three-loop relation between the
and on-shell quark mass definitions is presented. To complete
the presentation, some technical details are presented in the Appendix, where
also explicit analytical results are listed.Comment: 125 pages, to appear in Physics Reports, eqs. (4.11), (4.77), (4.79)
and (C.3) corrected, references and note adde
Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an
Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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