Quantization of a gauge theory on a curved noncommutative space

We study quantization of a gauge analogon of the Grosse-Wulkenhaar model: we find divergent one-loop contributions to the 1-point and 2-point Green functions. We obtain that five counterterms are necessary for renormalization and that all divergences are logarithmic.Comment: 23 pages, 3 figure

AdS-inspired noncommutative gravity on the Moyal plane

We consider noncommutative gravity on a space with canonical noncommutativity that is based on the commutative MacDowell-Mansouri action. Gravity is treated as gauge theory of the noncommutative $SO(1,3)_\star$ group and the Seiberg-Witten (SW) map is used to express noncommutative fields in terms of the corresponding commutative fields. In the commutative limit the noncommutative action reduces to the Einstein-Hilbert action plus the cosmological term and the topological Gauss-Bonnet term. After the SW expansion in the noncommutative parameter the first order correction to the action, as expected, vanishes. We calculate the second order correction and write it in a manifestly gauge covariant way.Comment: 22 pages, no figures, final versio

The Standard Model on Non-Commutative Space-Time: Electroweak Currents and Higgs Sector

In this article we review the electroweak charged and neutral currents in the Non-Commutative Standard Model (NCSM) and compute the Higgs and Yukawa parts of the NCSM action. With the aim to make the NCSM accessible to phenomenological considerations, all relevant expressions are given in terms of physical fields and Feynman rules are provided.Comment: 33 pages, axodraw.sty; shortened, comments and references added, version to appear in EPJ

(Non)renormalizability of the D-deformed Wess-Zumino model

We continue the analysis of the $D$-deformed Wess-Zumino model which was started in the previous paper. The model is defined by a deformation which is non-hermitian and given in terms of the covariant derivatives $D_\alpha$. We calculate one-loop divergences in the two-point, three-point and four-point Green functions. We find that the divergences in the four-point function cannot be absorbed and thus our model is not renormalizable. We discuss possibilities to render the model renormalizable.Comment: 19 pages; version accepted for publication in Phys.Rev.D; new section with the detailed discussion on renormalizabilty added and a special choice of coupling constants which renders the model renormalizable analyze

Dynamical analysis of particular class of time-delay control systems

U disertaciji su razmatrani problemi dinamike analize posebnih klasa sistema sa istim vremenskim kašnjenjem. Prošireni su osnovni rezultati na polju ljapunovske stabilnosti linearnih, vremenski diskretnih sistema sa istim vremenskim kašnjenjem. Data je Ljapunov–Krasovski metoda za vremenski diskretne sisteme sa istim vremenskim kašnjenjem. Prezentovani su potrebni i dovoljni uslovi asimptotske stabilnosti, zavisne od isto vremenskog kašnjenja, linearnih, vremenski kontinualnih i diskretnih sistema sa istim vremenskim kašnjenjem. Dati su dovoljni uslovi asimptotske stabilnosti, nezavisne od isto vremenskog kašnjenja, klase linearnih, perturbovanih sistema sa višestrukim vremenskim kašnjenjem. Prezentovani su dovoljni uslovi D–stabilnosti klase linearnih, vremenski diskretnih sistema sa istim vremenskim kašnjenjem. Dati su dovoljni uslovi eksponencijalne stabilnosti vremenski diskretnih sistema sa istim vremenskim kašnjenjem i perturbacijama. Prezentovani su potrebni i dovoljni uslovi kvadratne stabilnosti linearnih, vremenski diskretnih sistema sa istim vremenskim kašnjenjem u stanju i neodreenostima. Potrebni i dovoljni uslovi asimptotske stabilnosti, zavisni od isto vremenskog kašnjenja, velikih, linearnih, vremenski kontinualnih i diskretnih sistema sa istim vremenskim kašnjenjem, su dati. Prouena je stabilnost velikih, intervalnih, vremenski kontinualnih i diskretnih sistema sa istim vremenskim kašnjenjem. Izvedeni su novi dovoljni kriterijumi, zavisni i nezavisni od isto vremenskog kašnjenja, stabilnosti na konanom vremenskom intervalu i atraktivne praktine stabilnosti linearnih, vremenski kontinualnih i diskretnih sistema sa istim vremenskim kašnjenjem, kao i odgovarajui rezultati koji se tiu problema praktine nestabilnosti. Istražen je problema stabilnosti na konanom vremenskom intervalu za klasu linearnih, vremenski diskretnih sistema sa vremenski promenljivim kašnjenjem. Numeriki primeri su dati da demonstriraju primenu prezentovanih metoda.control systems are considered. Some of the basic results in the area of Lyapunov stability of linear, discrete time–delay systems are extended. A Lyapunov–Krasovskii method for discrete time–delay systems is gived. Necessary and sufficient conditions for delay–dependent asymptotic stability of linear, continuous and discrete time–delay systems is offered. Sufficient conditions, independent of delay, for asymptotic stability of a particular class of linear perturbed time–delay systems with multiple delays are gived. New sufficient conditions for the D–stability of a particular class of linear, discrete time–delay systems are established. Sufficient conditions for the exponential stability of discrete time–delay systems with perturbations are gived. Necessary and sufficient conditions for quadratic stability of uncertain linear discrete systems with state delay are presented. New necessary and sufficient conditions for delay–dependent asymptotic stability of a particular class of large–scale, linear, continuous and discrete time–delay systems are established. The stability of continuous and discrete large–scale time–delay interval systems are considered. A new sufficient delay–dependant and delay–independent criteria for the finite time stability and attractive practical stability of linear continuous and discrete time–delay systems has been derived, as well as corresponding results concerning instability problems. Finite–time stability problem has been investigated for a class of linear discrete time–varying delay systems. Numerical examples are given to demonstrate the application of the proposed methods

Assessment of postoperative hormonal therapy in recurance of recidives in patients operated of ovarian endometriosis

Uvod:Endometrioza je jedno od čestih oboljenja u reproduktivnom dobu žene. Od nje boluje 5-10% celokupne ženske populacije.Tretman endometrioze može biti hiruški i medikamentozni. Poslednjih desetak godina u terapiji se upotrebljavaju analozi Gonadotropin rilizing hormona. Upotreba analoga GnRH značajno smanjuje simptome endometrioze . I pored velikog napredka u hiruškim tehnikama a i zbog same prirode oboljenja, endometrioza često recidivira. Ciljevi istraživanja:Utvrditi procenat pojave recidiva kod operisanih pacijentkinja zbog endometrioze jajnika u odnosu na stadijum bolesti i vrstu uradjene operacije, a koje su posle operacije primale supresivnu terapiju GnRH alaoga u odnosu na one koje posle operacije nisu primale supresivnu terapiju. Metode i materijal:Ispitivanje je predstavljalo prospektivnu studiju koja je izvedena na Ginekološko-akušerskoj klinici „Narodni Front“ u Beogradu, u dvogodišnjem periodu. Ispitivanjem je obuhvaćeno 200 pacijentkinja sa endometriomom jajnika a koje operisane laparoskopskim putem. Pacijentkinje su bile životne dobi od 20. – 45. godine.Operisane pacijentkinje su podeljene u dve grupe, ispitivanu i kontrolnu grupu. Ispitivanu grupu sačinjavaju 100 pacijentkinja operisanih laparoskopskim putem zbog endometriotičnih cista jajnika, a kod kojih je posle operacije primenjena supresivna terapija analozima GnRH. Od analoga GnRH primenjivan je Triptorelin u obliku acetata tj. Dipherelin 3,75 mg intra muskularno, jednom mesečno ili Goserelin u obliku acetata tj. Zoladex 3,6 mg subkutano u prednji trbušni zid, jednom mesečno. Analozi GnRH su davani u toku 4 do 6 meseci u zavisnosti od stepena težine endometrioze. U zavisnosti od vrste operativnog zahvata, sve pacijentkinje ispitivane grupe su podeljene u dve podgrupe. Prvu podgrupu sačinjavaju pacijentkinje kod kojih je urađena laparoskopska cistektomija, dok drugu podgrupu sačinjavaju pacijentkinje kod kojih je urađena laparoskopska cistotomija i koagulacija kapsule ciste. Odluku o tome koja je vrsta operacije urađena kod pacijentkinje donosio je operator u zavisnosti od operativnog nalaza.Stepen težine endometrioze je procenjen po klasifikaciji Američkog udruženja za fertilitet i sterilitet ( AFS klasifikacija)..

Analysis of chromosomal translocation T(11;19) in mucoepidermoid carcinoma of salivary glands - correlation with clinical and histopathological parameters

Kod velikog broja salivarnih mukoepidermoidnih karcinoma (MEK) detektovana je rekurentna t(11;19) hromozoska translokacija čiji je proizvod novostvoreni fuzio onkogen (MECT1-MAML2). Prisustvo MECT1-MAML2 onkogena remeti normalan ćelijski ciklus i ćelijsku diferencijaciju, dovodeći do nastanka i razvoja tumora. Ciljevi ove studije bili su da se utvrdi incidenca MECT1-MAML2 fuzije kod srpskih pacijenata, zatim da se ispita odnos MECT1-MAML2 fuzije sa kliničkim i histopatološkim karakteristikama MEK-a, kao i da se utvrdi relevantnost ove fuzije kao molekularnog markera biološkog ponašanja MEK-a. U ovoj retrospektivnoj studiji, 20 slučajeva MEK-a i 23 slučajeva MEK-ovih imitacija je bilo testirano na prisustvo MECT1-MAML2 fuzije koristeći reverznu transkriptazu-polimeraznu lančanu reakciju (RT-PCR). Klinički i histopatološki parametri zajedno sa preživljavanjem bez znakova bolesti i ukupnim vremenom preživljavanja su ispitivani u odnosu na MECT1-MAML2 fuzioni status. MEK imitacije (n=23) su definisane kao ne-MEK grupa i svi slučajevi ovih karcinoma su bili negativni na MECT1-MAML2 fuziju. Kod MEK-a (n=20) fuzija je bila detektovana u 8 slučajeva (40%). Prisustvo MECT1-MAML2 fuzije je bilo povezano sa niskim histološkim gradusom tumora (P = 0.02), sa preživljavanjem bez znakova bolesti (P= 0.002) i ukupnim vremenom preživljavanja (P=0.046). Ova studija je pokazala da su LG fuzio-pozitivni MEK-i poseban kliničko-histopatološki entitet, zatim da MECT1-MAML2 fuzija može da se koristi kao pomoćni dijagnostički i prognostički marker za mukoepidermoidni karcinom.A significant number of salivary mucoepidermoid carcinoma (MEC) harbor a recurring t(11;19) translocation with an associated novel fusion oncogene (MECT1-MAML2). The MECT1-MAML2 oncogene disrupts normal cell-cycle and differentiation, contributing to tumor development. The objectives of this study were to establish the incidence of MECT1-MAML2 fusion in Serbian patients, to examine the correlation between MECT1-MAML2 status and clinico-pathological parameters of MECs, and estimate its relevance as a genetic marker of MEC behavior. In this retrospective study, 20 cases of MEC of salivary glands and 23 cases of MEC mimics were tested for the presence of MECT1-MAML2 fusion using reverse transcriptase-polymerase chain reaction (RT-PCR). Histopatological as well as clinical parameters, disease free survival, and overall survival data were examined in relation to fusion status. MEC mimics (n=23) were defined as non-MECs and all these cases were negative for the MECT1-MAML2 fusion. In the group of confirmed MECs (n=20) the MECT1-MAML2 fusion was detected in 8 cases (40%). The presence of the MECT1-MAML2 fusion was associated with low-grade tumor histology (P = 0.02), with disease-free survival (P= 0.002) and with overall survival rate (P=0.046). The study has shown that the LG fusio-positive MECs represent unique clinico-histopatological entity, as well as that the presence of the MECT1-MAML2 fusion can serve as an additional diagnostic and prognostic marker for mucoepidermoid carcinomas

Differential algebras on kappa-Minkowski space and action of the Lorentz algebra

We propose two families of differential algebras of classical dimension on kappa-Minkowski space. The algebras are constructed using realizations of the generators as formal power series in a Weyl super-algebra. We also propose a novel realization of the Lorentz algebra so(1,n-1) in terms of Grassmann-type variables. Using this realization we construct an action of so(1,n-1) on the two families of algebras. Restriction of the action to kappa-Minkowski space is covariant. In contrast to the standard approach the action is not Lorentz covariant except on constant one-forms, but it does not require an extra cotangent direction.Comment: 16 page

Gauge theories on the kappa-Minkowski spacetime

This study of gauge field theories on kappa-deformed Minkowski spacetime extends previous work on field theories on this example of a noncommutative spacetime. We construct deformed gauge theories for arbitrary compact Lie groups using the concept of enveloping algebra-valued gauge transformations and the Seiberg-Witten formalism. Derivative-valued gauge fields lead to field strength tensors as the sum of curvature- and torsion-like terms. We construct the Lagrangians explicitly to first order in the deformation parameter. This is the first example of a gauge theory that possesses a deformed Lorentz covariance.Comment: 17 pages, few minor revision