Hamilton - Jacobi treatment of front-form Schwinger model

The Hamilton-Jacobi formalism was applied to quantize the front-form Schwinger model. The importance of the surface term is discussed in detail. The BRST-anti-BRST symmetry was analyzed within Hamilton-Jacobi formalism.Comment: 11 pages, to be published in Int. Journ. Mod. Phys.

First Order Actions: a New View

We analyse systems described by first order actions using the Hamilton-Jacobi (HJ) formalism for singular systems. In this study we verify that generalized brackets appear in a natural way in HJ approach, showing us the existence of a symplectic structure in the phase spaces of this formalism

Hamilton-Jacobi quantization of singular Lagrangians with linear velocities

In this paper, constrained Hamiltonian systems with linear velocities are investigated by using the Hamilton-Jacobi method. We shall consider the integrablity conditions on the equations of motion and the action function as well in order to obtain the path integral quantization of singular Lagrangians with linear velocities.Comment: late

Multi Hamilton-Jacobi quantization of O(3) nonlinear sigma model

The O(3) non-linear sigma model is investigated using multi Hamilton-Jacobi formalism. The integrability conditions are investigated and the results are in agreement with those obtained by Dirac's method. By choosing an adequate extension of phase space we describe the transformed system by a set of three Hamilton-Jacobi equations and calculate the corresponding action.Comment: 10 pages, LaTeX, to be published in Mod. Phys. Lett.

Hamilton-Jacobi treatment of a non-relativistic particle on a curved space

In this paper a non-relativistic particle moving on a hypersurface in a curved space and the multidimensional rotator are investigated using the Hamilton-Jacobi formalism. The equivalence with the Dirac Hamiltonian formalism is demonstrated in both Cartesian and curvilinear coordinates. The energy spectrum of the multidimensional rotator is equal to that of a pure Laplace-Beltrami operator with no additional constant arising from the curvature of the sphere.Comment: 10 pages, LaTe

Rod photoreceptors drive circadian photoentrainment across a wide range of light intensities.

In mammals, synchronization of the circadian pacemaker in the hypothalamus is achieved through direct input from the eyes conveyed by intrinsically photosensitive retinal ganglion cells (ipRGCs). Circadian photoentrainment can be maintained by rod and cone photoreceptors, but their functional contributions and their retinal circuits that impinge on ipRGCs are not well understood. Using mice that lack functional rods or in which rods are the only functional photoreceptors, we found that rods were solely responsible for photoentrainment at scotopic light intensities. Rods were also capable of driving circadian photoentrainment at photopic intensities at which they were incapable of supporting a visually guided behavior. Using mice in which cone photoreceptors were ablated, we found that rods signal through cones at high light intensities, but not at low light intensities. Thus, rods use two distinct retinal circuits to drive ipRGC function to support circadian photoentrainment across a wide range of light intensities

An Effective Technique in Treatment of Femoral Neck Fractures - Ostheosynthesis under Double Fluoroscopic Guidance

PURPOSE OF THE STUDY The most commonly used technique for fixation of the femoral neck fractures is percutaneous osteosynthesis with cannulated screw under fluoroscopy guidance. Osteosynthesis performed under single-fluoroscopic guidance requires continuous repositioning the fluoroscope to obtain biplane imaging. This study aimed to evaluate whether there is a statistically significant difference between the osteosynthesis procedures performed under guidance of single-fluoroscopy and double fluoroscopy with respect to radiation emission safety and treatment parameters for fixation of femoral neck fractures. MATERIAL AND METHODS This retrospective study included 35 patients operated for femoral neck fracture between December 2013 and October 2017. Osteosynthesis was performed in 21 of these patients using cannulated screw under guidance of single-fluoroscopy whereas other 14 patients underwent same type of osteosynthesis assisted by double-fluoroscopy. The parameters of these two groups such as duration of surgery preparation, duration of the surgery, duration of radiation exposure, collo-diaphyseal angle and Harris hip score values were recorded. RESULTS No significant difference was found between the groups regarding time for surgery preparation (p > 0.05). On the other hand, duration of surgery and overall duration of radiation exposure were found 14 (p 0.05). CONCLUSIONS Use of double-fluoroscopy significantly reduces time of surgical duration and also level of radiation exposure in surgery of femoral neck fractures

Motives for reforms on civil–military relations in Turkey

ABSTRACT: This article examines the progress and shortcomings of democratic control of armed forces (DCAF) reforms in Turkey and seeks to question how Turkey might be further motivated to implement reforms. It questions official motives in each reform process and finds two main motives for progress: the prospect of EU accession and democratization. It finds the motive for the existing shortcomings as the goal for allowing a degree of authority for military within DCAF in order to prevent political abuse of military power. Thus it seems that Turkey might be motivated to overcome these shortcomings only when its understanding of DCAF details a full subordination of military to civilian authority. © 2016 Taylor & Francis