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Agadjanov D.,University of Bonn | Agadjanov D.,Georgian University of St. Andrew | Meissner U.-G.,University of Bonn | Meissner U.-G.,Julich Research Center | Rusetsky A.,University of Bonn
Journal of High Energy Physics | Year: 2014

The possibility of imposing partially twisted boundary conditions is investigated for the scalar sector of lattice QCD. According to the commonly shared belief, the presence of quark-antiquark annihilation diagrams in the intermediate state generally hinders the use of the partial twisting. Using effective field theory techniques in a finite volume, and studying the scalar sector of QCD with total isospin I = 1, we however demonstrate that partial twisting can still be performed, despite the fact that annihilation diagrams are present. The reason for this are delicate cancellations, which emerge due to the graded symmetry in partially quenched QCD with valence, sea and ghost quarks. The modified Lüscher equation in case of partial twisting is given. © 2014 The Author(s). Source

Maglakelidze N.,Georgian University of St. Andrew
Bulletin of the Georgian National Academy of Sciences | Year: 2016

Present study investigated possible differences between the effects of intravenous injection of OrexinA and OrexinB on the ultradian structure of sleep-wakefulness cycle and food motivation in rats. Two doses of these neuropeptides (5μg/ml and/or 10μg/ml) were injected in the tail vein. Continuous EEG registration of baseline sleep-wakefulness cycle during 5 h period daily (11.00 a.m.-16.00 a.m.) was started after post-surgery recovery period. Three baseline ultradian structures were registered on each animal so each animal served as a control for itself. After establishment of the stable baseline SWC ultradian structure OrexinA and/or OrexinB (from PHOENIX PHARMACEUTICALS) were injected in the tail vein at 10.55 a.m., than EEG registration of sleep-wakefulness cycle ultradian structure was started at 11.00 a.m., as in baseline recordings. Significant data were obtained about the whole effectiveness of i.v. OrexinA and ineffectiveness of i.v. OrexinB on sleep-wakefulness cycle ultradian structure. In contrast to i.v. OrexinB i.v. OrexinA produced significant increase of active wakefulness incidence, total time and percentage, whole suppression of REM sleep, and substantial changes in non-REM sleep stages-reduction of their incidence, total time and percentage. Because OrexinA has similar affinity to both Orexin receptor-1 and Orexin receptor-2 while OrexinB reveals a 10-fold higher affinity to Orexin receptor-2 it is possible to speak about the significance of Orexin receptor-1 for the sleep-wakefulness cycle disorders described in the present study. Therefore we can suggest that systemic administration of antagonists for Orexin receptor-1 can be effective for the aim of clinical therapy of insomnia. © 2016 Bull. Georg. Natl. Acad. Sci. Source

Agadjanov D.,University of Bonn | Agadjanov D.,Georgian University of St. Andrew | Guo F.-K.,University of Bonn | Rios G.,University of Bonn | Rusetsky A.,University of Bonn
Journal of High Energy Physics | Year: 2015

Abstract: We propose a method to study the nature of exotic hadrons by determining the wave function renormalization constant Z from lattice simulations. It is shown that, instead of studying the volume-dependence of the spectrum, one may investigate the dependence of the spectrum on the twisting angle, imposing twisted boundary conditions on the fermion fields on the lattice. In certain cases, e.g., the case of the DK bound state which is addressed in detail, it is demonstrated that the partial twisting is equivalent to the full twisting up to exponentially small corrections. © 2015, The Author(s). Source

Kachakhidze M.K.,Georgian University of St. Andrew | Kiladze R.,Ilia State University | Kachakhidze N.,Georgian University of St. Andrew | Kukhianidze V.,Ilia State University | Ramishvili G.,Ilia State University
Natural Hazards and Earth System Science | Year: 2010

It is acceptable that earthquakes certain exogenous (cosmic) triggering factors may exist in every seismoactive (s/a) region and in Caucasus among them. They have to correct earthquake occurring moment or play the triggering role in case when the region is at the limit of the critical value of the geological medium of course. Our aim is to reveal some exogenous factors possible to initiate earthquakes, on example of Caucasus s/a region, taking into account that the region is very complex by the point of view of the tectonic stress distribution. The compression stress directed from North to South (and vice versa) and the spread stress directed from East to West (and vice versa) are the main stresses acted in Caucasus region. No doubt that action of the smallest external stress may "work" as earthquakes triggering factor. In the presented work the Moon and the Sun perturbations are revealed as initiative agents of earthquakes when the directions of corresponding exogenous forces coincide with the directions of the compression stress or the spreading tectonic stress in the region. © Author(s) 2010. Source

Kachakhidze M.K.,Georgian University of St. Andrew | Kereselidze Z.A.,Nodia Institute of Geophysics | Kachakhidze N.K.,Georgian University of St. Andrew | Ramishvili G.T.,Ilia State University | Kukhianidze V.J.,Ilia State University
Natural Hazards and Earth System Science | Year: 2012

The present paper deals with an attempt to check the theoretical model of self-generated seismo-electromagnetic oscillations of LAI system on the basis of retrospective data. Application of the offered simple model enables one to explain qualitatively the mechanism of VLF electromagnetic emission initiated in the process of an earthquake preparation. Besides, the model enables us to associate telluric character geoelectric and geomagnetic perturbations incited by rock polarization and self-generated electromagnetic oscillations of lithosphere-atmosphere system. L'Aquila earthquake taken as an example to isolate reliably the Earth VLF emission from the magnetospheric electromagnetic emission of the same frequency range, MHD criterion is offered together with geomagnetic activity indexes. On the basis of the considered three earthquakes, according to the opinion of authors the model of self-generated seismo-electromagnetic oscillations of the LAI system will enable us to approach the problem of resolution of earthquake prediction with certain accuracy. © Author(s) 2012. CC Attribution 3.0 License. Source

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