Schwarzschild-De Sitter black holes in 4+1 dimensional bulk

We construct a static solution for 4+1 dimensional bulk such that the 3+1 dimensional world has a linear warp factor and describes the Schwarzschild-dS_{4} black hole. For m=0 this four dimensional universe and Friedmann Robertson Walker universe are related with an explicit coordinate transformation. We emphasize that for linear warp factors the effect of bulk on the brane world shows up as the dS_{4} background which is favored by the big bang cosmology.Comment: 6 page

Closed timelike curves and geodesics of Godel-type metrics

It is shown explicitly that when the characteristic vector field that defines a Godel-type metric is also a Killing vector, there always exist closed timelike or null curves in spacetimes described by such a metric. For these geometries, the geodesic curves are also shown to be characterized by a lower dimensional Lorentz force equation for a charged point particle in the relevant Riemannian background. Moreover, two explicit examples are given for which timelike and null geodesics can never be closed.Comment: REVTeX 4, 12 pages, no figures; the Introduction has been rewritten, some minor mistakes corrected, many references adde

Universal optical amplification without nonlinearity

We propose and experimentally realize a new scheme for universal phase-insensitive optical amplification. The presented scheme relies only on linear optics and homodyne detection, thus circumventing the need for nonlinear interaction between a pump field and the signal field. The amplifier demonstrates near optimal quantum noise limited performance for a wide range of amplification factors.Comment: 5 pages, 4 figure

INVESTİGATİON OF THE EFFECTS OF FOOTBALL TO SOLE

The aim of this research is to investigate the effect of playing soccer for a long time in professional soccer players to sole contact area. 15 football players (22,65 ± 2,6 years, 174,2 ± 5,6 cm height, 71,2 ± 4,8 kg body weight, 23,21 ± 1,4 kg / m² BMI) who play in the Sports Betting Super League teams, the top league of the Turkish Football Federation, who has no problem on his foot and 15 male volunteers (22,6 ± 1,6 years, 177,3 ± 5,4 cm height, 72,1 ± 3,3 kg body weight, 23,01 ± 1,9 kg / m² BMI) as control group was included in the survey. Professional footballers' age of starting football was determined as 9 years old. It has been determined that there is no anatomic disorder or discomfort in the foot, waist and knee areas which will affect the results of the foot contact area analysis in the study groups. EMED-SF (Germany) plantar pressure analysis system was used in the study. Statistically significant differences between the study groups were examined using the non-parametric Mann-Whitney U test. According to the results of the research, there was no statistically difference between the experimental and control groups in terms of physical characteristics. However, Significant results were found at (0.01-0.05) level in the beginning and grand total of heel medial, heel lateral, 1.2.3.4.5 metatars in the maximal force comparisons applied to the right and left foot contact area and the floor. Furthermore, it was determined that the values of the control group were higher than the values of the experimental group.  Article visualizations

Needed: a systems approach to improve flood risk mitigation through private precautionary measures

Private precautionary measures play an increasingly important role in flood risk management. The degree to which private precautionary measures mitigate flood risk depends mainly on the type of measure (and how effective it is) and how frequently and successfully it is implemented. These aspects are influenced by a complex interaction of physical and socio-economic processes, which makes the assessment and the prediction of the mitigation of flood risk via private precautionary measures a challenge. This paper provides an overview of factors and processes that influence the implementation and effectiveness of private precaution in mitigating flood risk, underpinning it with highlights from international examples. We recommend private precautionary measures for further use to improve flood risk mitigation, but stress that they need to be considered and implemented through a holistic systems approach to maximize their effectiveness

Gauss-Bonnet Gravity with Scalar Field in Four Dimensions

We give all exact solutions of the Einstein-Gauss-Bonnet Field Equations coupled with a scalar field in four dimensions under certain assumptions.Comment: Latex file, 7 page

Distraction osteogenesis in a severe mandibular deficiency

OBJECTIVE: Distraction osteogenesis is an alternative treatment method for the correction of mandibular hypoplasia. In this case report, distraction with a multidirectional extraoral device was performed to gradually lengthen the corpus and ramus of a patient who had a severe hypoplastic mandible. MATERIALS AND METHODS: The patient underwent bilateral extraoral ramus and corpus distraction osteogenesis. After seven days of latency period, distraction was performed 0.5 mm twice a day. Subsequent consolidation period was 12 weeks. RESULTS: The patient's mandible was elongated successfully. Cephalometric analysis revealed that ANB angle decreased from 13° to 6°, overjet of 15 mm decreased to 4 mm, corpus length increased from 49 mm to 67 mm, and ramus length increased from 41 mm to 43 mm. Posterior airway space (PAS) also increased due to advancement of the mandible. In stereolithographic model evaluation it was determined that the distances from condylion to gonion and from gonion to pogonion increased. CONCLUSION: Satisfactory results from both aesthetic and functional standpoints were obtained by distraction osteogenesis of the ramus and corpus

Experimental Demonstration of Squeezed State Quantum Averaging

We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.Comment: 4 pages, 5 figure