61 research outputs found

    Noncommutative N=1 super Yang-Mills, the Seiberg-Witten map and UV divergences

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    Classically, the dual under the Seiberg-Witten map of noncommutative U(N), {\cal N}=1 super Yang-Mills theory is a field theory with ordinary gauge symmetry whose fields carry, however, a \theta-deformed nonlinear realisation of the {\cal N}=1 supersymmetry algebra in four dimensions. For the latter theory we work out at one-loop and first order in the noncommutative parameter matrix \theta^{\mu\nu} the UV divergent part of its effective action in the background-field gauge, and, for N>=2, we show that for finite values of N the gauge sector fails to be renormalisable; however, in the large N limit the full theory is renormalisable, in keeping with the expectations raised by the quantum behaviour of the theory's noncommutative classical dual. We also obtain --for N>=3, the case with N=2 being trivial-- the UV divergent part of the effective action of the SU(N) noncommutative theory in the enveloping-algebra formalism that is obtained from the previous ordinary U(N) theory by removing the U(1) degrees of freedom. This noncommutative SU(N) theory is also renormalisable.Comment: 33 pages, 4 figures. Version 2: Unnecessary files removed. Version 3: New types of field redefinitions were considered, which make the large N U(N) and the SU(N) theories renormalisable. The conclusions for U(N) with finite N remain unchanged. Version 4: Corrected mistyped equations, minor revision

    Renormalizability of noncommutative SU(N) gauge theory

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    We analyze the renormalizability properties of pure gauge noncommutative SU(N) theory in the θ\theta-expanded approach. We find that the theory is one-loop renormalizable to first order in θ\theta.Comment: 11 pages, minor changes, accepted for publication in JHE

    Inhibitory effect of coumarin derivatives on apple (cv. Idared) polyphenol oxidase

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    Inhibitory effect of 32 coumarin derivatives (20 Schiff bases, 5 thiosemicarbazides, 5 thiazolidinones, and their precursors, 7-hydroxy-4-methylcoumarin and 4-methylcoumarin-7-yl hydrazine carboxylate) on partially purified apple polyphenol oxidase was investigated. Thirteen coumarin derivatives inhibited polyphenol oxidase (5 Schiff bases, 5 thiosemicarbazides, 1 thiazolidinone, 4-methyl-7-hydroxycoumarin and 4-methylcoumarin-7-yl hydrazine carboxylate), while 19 derivatives showed no effect on enzyme activity. The most effective inhibitors were thiosemicarbazides, with 4-methyl-1-(2-(4-methyl-2-oxo-2H-chromen-7-yloxy)acetyl) thiosemicarbazide (compound C23) being the most prominent inhibitor (IC50 = 10.45 µM). The importance of thiosemicarbazide moiety as crucial structure element for strong apple PPO inhibition was confirmed by its cyclisation to thiazolidinone bearing the same substituents as corresponding thiosemicarbazide. Capture of the sulphur atom of thiosemicarbazide group within tiazolidinone ring caused significant loss of inhibitory effect against apple PPO

    Emergence of classical behavior from the quantum spin

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    Classical Hamiltonian system of a point moving on a sphere of fixed radius is shown to emerge from the constrained evolution of quantum spin. The constrained quantum evolution corresponds to an appropriate coarse-graining of the quantum states into equivalence classes, and forces the equivalence classes to evolve as single units representing the classical states. The coarse-grained quantum spin with the constrained evolution in the limit of the large spin becomes indistinguishable from the classical system

    TeV Scale Implications of Non Commutative Space time in Laboratory Frame with Polarized Beams

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    We analyze e+eγγe^{+}e^{-}\rightarrow \gamma\gamma, eγeγe^{-}\gamma \rightarrow e^{-}\gamma and γγe+e\gamma\gamma \rightarrow e^{+}e^{-} processes within the Seiberg-Witten expanded noncommutative scenario using polarized beams. With unpolarized beams the leading order effects of non commutativity starts from second order in non commutative(NC) parameter i.e. O(Θ2)O(\Theta^2), while with polarized beams these corrections appear at first order (O(Θ)O(\Theta)) in cross section. The corrections in Compton case can probe the magnetic component(ΘB\vec{\Theta}_B) while in Pair production and Pair annihilation probe the electric component(ΘE\vec{\Theta}_E) of NC parameter. We include the effects of earth rotation in our analysis. This study is done by investigating the effects of non commutativity on different time averaged cross section observables. The results which also depends on the position of the collider, can provide clear and distinct signatures of the model testable at the International Linear Collider(ILC).Comment: 22 pages, 19 figures, new comments and references added, few typos corrected, Published in JHE

    On divergent 3-vertices in noncommutative SU(2)gauge theory

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    We analyze divergencies in 2-point and 3-point functions for noncommutative θ\theta-expanded SU(2)-gauge theory with massless fermions. We show that, after field redefinition and renormalization of couplings, one divergent term remains.Comment: 7 page

    The relationship between somatic and psychosocial factors and systemic blood pressure in hypertensive and normotensive workers

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    Devetsto radnika starih 35 - 59 godina podvrgnuto je kliničkom, elektrokardiografskom i psihološkom ispitivanju. Prevalencija arterijske hipertenzije bila je 15,2%. Pozitivna obiteljska anamneza za hipertenziju bila je prisutna u 87 (63,5%) hipertenizivnih i 41 (29,9%) normotenzivnog radnika (P 0,05). Između hipertenzivnih i normotenzivnih radnika nije bilo značajne razlike u jačini osam bazičnih emocija, kao ni u zadovoljenju životnih potreba (P > 0,05). Multiplom regresijskom analizom ustanovljeno je da SU dob i srčana frekvencija značajni prediktori za sistolički krvni tlak u obje skupine. Ove varijable bile su značajniji prediktori u hipertenzivnoj skupini. Ostale varijable, tjelesna masa i zadovoljstvo radnim mjestom i osobnim dohotkom, nisu se pokazale značajnim prediktorima. Značajni prediktor dijastoličkog krvnog tlaka u normotenzivnih radnika bila je tjelesna masa. U hipertenzivnih radnika ova varijabla nije značajno utjecala na visinu dijastoličkog tlaka. Osam bazičnih emocija po Plutchiku i zadovoljenost životnih potreba nisu bili značajni prediktori sistemskog tlaka niti u hipertenzivnih niti u normotenzivnih radnika. Naša studija potvrdila je heterogenost prediktora sistemskog tlaka u normotenzivnih i hipertenzivnih radnika.A cohort of 900 workers aged 35 - 59 years underwent clinical electrographical and psychological examinations. The prevalence of arterial hypertension was 15.2%. Family history of hypertension was positive in 87 (63.5%) hypertensive and 41 (29.9%) normotensive workers (P 0.05). No significant difference in the intensity of eight basic emotions was found between the hypertensive and normotensive persons (P> 0.05). According to multiple regression analysis the most predictive variables of systolic blood pressure in both groups were age and resting heart rate. The two variables were more significant predictors in the hypertensive than in the normotensive group. The most predictive variable of diastolic blood pressure among the normotensive workers was body index. For the hypertensive workers this variable was not a significant predictor of diastolic blood pressure. The eight basic emotions according to Plutchik and the life need satisfaction were not significant predictors of systemic blood pressure either with the hypertensive or normotensive workers

    Geometry of the Grosse-Wulkenhaar Model

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    We define a two-dimensional noncommutative space as a limit of finite-matrix spaces which have space-time dimension three. We show that on such space the Grosse-Wulkenhaar (renormalizable) action has natural interpretation as the action for the scalar field coupled to the curvature. We also discuss a natural generalization to four dimensions.Comment: 16 pages, version accepted in JHE

    MicroRNAs miR-203-3p, miR-664-3p and miR-708-5p are associated with median strain lifespan in mice

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    This is the final version of the article. Available from Springer Nature via the DOI in this record.MicroRNAs (miRNAs) are small non-coding RNA species that have been shown to have roles in multiple processes that occur in higher eukaryotes. They act by binding to specific sequences in the 3' untranslated region of their target genes and causing the transcripts to be degraded by the RNA-induced silencing complex (RISC). MicroRNAs have previously been reported to demonstrate altered expression in several aging phenotypes such as cellular senescence and age itself. Here, we have measured the expression levels of 521 small regulatory microRNAs (miRNAs) in spleen tissue from young and old animals of 6 mouse strains with different median strain lifespans by quantitative real-time PCR. Expression levels of 3 microRNAs were robustly associated with strain lifespan, after correction for multiple statistical testing (miR-203-3p [β-coefficient = -0.6447, p = 4.8 × 10(-11)], miR-664-3p [β-coefficient = 0.5552, p = 5.1 × 10(-8)] and miR-708-5p [β-coefficient = 0.4986, p = 1.6 × 10(-6)]). Pathway analysis of binding sites for these three microRNAs revealed enrichment of target genes involved in key aging and longevity pathways including mTOR, FOXO and MAPK, most of which also demonstrated associations with longevity. Our results suggests that miR-203-3p, miR-664-3p and miR-708-5p may be implicated in pathways determining lifespan in mammals.This work was funded by the Wellcome Trust (grant number WT097835MF to D. Melzer and L.W. Harries), and the NIH-NIA (grant number AG038070 to The Jackson Laboratory)

    Dynamics of FitzHugh-Nagumo excitable systems with delayed coupling

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    Small lattices of NN nearest neighbor coupled excitable FitzHugh-Nagumo systems, with time-delayed coupling are studied, and compared with systems of FitzHugh-Nagumo oscillators with the same delayed coupling. Bifurcations of equilibria in N=2 case are studied analytically, and it is then numerically confirmed that the same bifurcations are relevant for the dynamics in the case N>2N>2. Bifurcations found include inverse and direct Hopf and fold limit cycle bifurcations. Typical dynamics for different small time-lags and coupling intensities could be excitable with a single globally stable equilibrium, asymptotic oscillatory with symmetric limit cycle, bi-stable with stable equilibrium and a symmetric limit cycle, and again coherent oscillatory but non-symmetric and phase-shifted. For an intermediate range of time-lags inverse sub-critical Hopf and fold limit cycle bifurcations lead to the phenomenon of oscillator death. The phenomenon does not occur in the case of FitzHugh-Nagumo oscillators with the same type of coupling.Comment: accepted by Phys.Rev.
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