3,174 research outputs found

    Twigraph: Discovering and Visualizing Influential Words between Twitter Profiles

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    The social media craze is on an ever increasing spree, and people are connected with each other like never before, but these vast connections are visually unexplored. We propose a methodology Twigraph to explore the connections between persons using their Twitter profiles. First, we propose a hybrid approach of recommending social media profiles, articles, and advertisements to a user.The profiles are recommended based on the similarity score between the user profile, and profile under evaluation. The similarity between a set of profiles is investigated by finding the top influential words thus causing a high similarity through an Influence Term Metric for each word. Then, we group profiles of various domains such as politics, sports, and entertainment based on the similarity score through a novel clustering algorithm. The connectivity between profiles is envisaged using word graphs that help in finding the words that connect a set of profiles and the profiles that are connected to a word. Finally, we analyze the top influential words over a set of profiles through clustering by finding the similarity of that profiles enabling to break down a Twitter profile with a lot of followers to fine level word connections using word graphs. The proposed method was implemented on datasets comprising 1.1 M Tweets obtained from Twitter. Experimental results show that the resultant influential words were highly representative of the relationship between two profiles or a set of profile

    General Tensor Lagrangians from Gravitational Higgs Mechanism

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    The gravitational Higgs mechanism proposed by 't Hooft in arXiv:0708.3184 involves the spacetime metric g_{mu nu} as well as the induced metric \bar{g}_{mu nu} proportional to \eta_{a b} \partial_{mu} \phi^a \partial_{nu} \phi^b where \phi^{a} (a=0,...,3), as we call it, break all four diffeomorphisms spontaneously via the vacuum expectation values proportional to x^a. In this framework, we construct and analyze the most general action density in terms of various invariants involving the curvature tensors, connexion coefficients, and the contractions and the determinants of the two metric fields. We show that this action admits a consistent expansion about the flat background such that the resulting Lagrangian possesses several novel features not found in the linearized Einstein-Hilbert Lagrangian with Fierz-Pauli mass term (LELHL-FP): (i) its kinetic part generalizes that of LELHL-FP by weighing the corresponding structures with certain coefficients generated by invariants, (ii) the entire Lagrangian is ghost-- and tachyon--free for mass terms not necessarily in the Fierz-Pauli form, and, (iii) a consistent mass term is generated with no apparent need to higher derivative couplings.Comment: 20 pp; added a referenc

    A Complete Version of the Glauber Theory for Elementary Atom - Target Atom Scattering and Its Approximations

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    A general formalism of the Glauber theory for elementary atom (EA) - target atom (TA) scattering is developed. A second-order approximation of its complete version is considered in the framework of the optical-model perturbative approach. A `potential' approximation of a second-order optical model is formulated neglecting the excitation effects of the TA. Its accuracy is evaluated within the second-order approximation for the complete version of the Glauber EA-TA scattering theory.Comment: PDFLaTeX, 10 pages, no figures; an updated versio

    Protracted fever after infliximab induction therapy in a patient with ulcerative colitis (clinical case)

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    Inflammatory bowel diseases (ulcerative colitis and Crohn’s disease) tend to increase in frequency and prevalence worldwide and lead to a significant reduction in quality of life with a complicated course. Intravenous administration of corticosteroids in acute severe ulcerative colitis is effective in 60–70 % of cases. Rescue therapy for patients with steroid‐refractory and steroid-dependence attacks is effective for reducing colectomy or colproctectomy and improves long-term treatment outcomes. Despite the proven efficacy of infliximab, limitations to the use of monoclonal antibodies are adverse reactions to the administration of genetically engineered biologic therapy (GEBT), both well-known and studied, and rare.The aim of the study. To analyze a case of an extremely rare and paradoxical incurable hyperergic reaction that occurred after using genetically engineered biological therapy with tumor necrosis factor alpha blockers in a patient suffering from ulcerative colitis.Materials and methods. We carried out the search in the PubMed, Embase, Scopus and Medline databases until November 1, 2022 using the following keywords: inflammatory bowel disease, ulcerative colitis (UC), anti-tumor necrosis factor α (antiTNFα), infliximab, fever, adverse events. In the scientific electronic library eLIBRARY, a search was made for Russian-language publications using similar queries in Russian. We analyzed the patient’s medical records from 03.06.2013 up to the present day; the patient signed an informed consent for the publication and discussion of the presented data.Conclusion. The widespread use of GEBT in the treatment of autoimmune and autoinflammatory diseases leads to the accumulation of both positive and negative experience of clinicians in real clinical practice. The officially described adverse events in the appointment of any drug suggest options for their prevention and treatment. Atypical manifestations or casuistic cases must be systematized for further fundamental pathophysiological studies

    Spin physics with antiprotons

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    New possibilities arising from the availability at GSI of antiproton beams, possibly polarised, are discussed. The investigation of the nucleon structure can be boosted by accessing in Drell-Yan processes experimental asymmetries related to cross-sections in which the parton distribution functions (PDF) only appear, without any contribution from fragmentation functions; such processes are not affected by the chiral suppression of the transversity function h1(x)h_1(x). Spin asymmetries in hyperon production and Single Spin Asymmetries are discussed as well, together with further items like electric and magnetic nucleonic form factors and open charm production. Counting rates estimations are provided for each physical case. The sketch of a possible experimental apparatus is proposed.Comment: Presented for the proceedings of ASI "Spin and Symmetry", Prague, July 5-10, 2004, to be published in Czech. J. Phys. 55 (2005

    Influence of anionic surfactant on stability of nanoparticles in aqueous solutions

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    Dispersion and aggregation of nanoparticles in aqueous solutions are important factors for safe and effective application of nanoparticles, for instance, in the oil industry. As conventional oil reserves are depleted, it is necessary to advance chemical enhanced oil recovery (cEOR) techniques to develop unconventional oil reservoirs. Nanoparticles modified by surfactants can be a promising reagent in cEOR. These nanomaterials can reduce interfacial tension and change the wettability of reservoir rock, which leads to an increase in oil recovery. However, the application of nanoparticles is limited by their substantial aggregation in aqueous solutions. The purpose of this work is to select nanoparticles for obtaining stable sols in water in the presence of an anionic surfactant and to optimize the conditions (pH) for further modifying the nanoparticles with the anionic surfactant. Sodium dodecyl sulfate (SDS) is used as an anionic surfactant. The aggregation of oxide and carbon nanoparticles in water and anionic surfactant solutions was studied by laser diffraction, dynamic and electrophoretic light scattering methods. Most of the studied nanoparticles in water form aggregates with bi-, three- and polymodal particle size distributions. TiO2 nanoparticles obtained by plasma dynamic synthesis form the most stable sols in anionic surfactant solutions. The range of 5–7 pH is defined as optimal for their modification with surfactants. The stability of carbon nanoparticles in aqueous solutions increases significantly in the presence of a surfactant. The obtained results form the basis for further research on the modification of marked nanoparticles in surfactant solutions

    Inadequacy of zero-width approximation for a light Higgs boson signal

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    In the Higgs search at the LHC, a light Higgs boson (115 GeV <~ M_H <~ 130 GeV) is not excluded by experimental data. In this mass range, the width of the Standard Model Higgs boson is more than four orders of magnitude smaller than its mass. The zero-width approximation is hence expected to be an excellent approximation. We show that this is not always the case. The inclusion of off-shell contributions is essential to obtain an accurate Higgs signal normalisation at the 1% precision level. For gg (-> H) -> VV, V= W,Z, O(10%) corrections occur due to an enhanced Higgs signal in the region M_VV > 2 M_V, where also sizable Higgs-continuum interference occurs. We discuss how experimental selection cuts can be used to exclude this region in search channels where the Higgs invariant mass cannot be reconstructed. We note that the H -> VV decay modes in weak boson fusion are similarly affected.Comment: 26 pages, 18 figures, 6 tables; added references, expanded introduction, version to appear in JHE

    The Path Integral Quantization And The Construction Of The S-matrix In The Abelian And Non-Abelian Chern-Simons Theories

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    The cvariant path integral quantization of the theory of the scalar and spinor particles interacting through the abelian and non-Abelian Chern-Simons gauge fields is carried out and is shown to be mathematically ill defined due to the absence of the transverse components of these gauge fields. This is remedied by the introduction of the Maxwell or the Maxwell-type (in the non-Abelian case)term which makes the theory superrenormalizable and guarantees its gauge-invariant regularization and renormalization. The generating functionals are constructed and shown to be formally the same as those of QED (or QCD) in 2+1 dimensions with the substitution of the Chern-Simons propagator for the photon (gluon) propagator. By constructing the propagator in the general case, the existence of two limits; pure Chern-Simons and QED (QCD) after renormalization is demonstrated. By carrying out carefully the path integral quantization of the non-Abelian Chern-Simons theories using the De Witt-Fadeev-Popov and the Batalin-Fradkin- Vilkovisky methods it is demonstrated that there is no need to quantize the dimensionless charge of the theory. The main reason is that the action in the exponent of the path integral is BRST-invariant which acquires a zero winding number and guarantees the BRST renormalizability of the model. The S-matrix operator is constructed, and starting from this S-matrix operator novel topological unitarity identities are derived that demand the vanishing of the gauge-invariant sum of the imaginary parts of the Feynman diagrams with a given number of intermediate on-shell topological photon lines in each order of perturbation theory. These identities are illustrated by an explicit example.Comment: LaTex file, 31 pages, two figure

    B-> D* zero-recoil formfactor and the heavy quark expansion in QCD: a systematic study

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    We present a QCD analysis of heavy quark mesons focussing on the B -> D* formfactor at zero recoil, F_D*(1). An advanced treatment of the perturbative corrections in the Wilsonian approach is presented. We estimate the higher-order power corrections to the OPE sum rule and describe a refined analysis of the nonresonant continuum contribution. In the framework of a model-independent approach, we show that the inelastic contribution in the phenomenological part of the OPE is related to the mQ-dependence of the hyperfine splitting and conclude that the former is large, lowering the prediction for F_D*(1) down to about 0.86. This likewise implies an enhanced yield of radial and D-wave charm excitations in semileptonic B decays and alleviates the problem with the inclusive yield of the wide excited states. We also apply the approach to the expectation values of dimension 7 and 8 local operators and to a few other issues in the heavy quark expansion.Comment: 70 pages, 13 figure
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