Separability and Hidden Symmetries of Kerr-Taub-NUT Spacetime in Kaluza-Klein Theory

The Kerr-Taub-NUT spacetime in the Kaluza-Klein theory represents a localized stationary and axisymmetric object in four dimensions from the Kaluza-Klein viewpoint. That is, it harbors companion electromagnetic and dilaton fields, thereby showing up the signature of the extra fifth dimension. We explore the separability structure of this spacetime and show that the Hamilton-Jacobi equation for geodesics admits the complete separation of variables only for massless geodesics. This implies the existence of the hidden symmetries in the spacetime, which are generated by the conformal Killing tensor. Using a simple trick built up on a conformally related metric (an "effective" metric) with the Killing tensor, we construct the explicit expression for the conformal Killing tensor.Comment: 10 pages; REVTe

Tarih boyunca İstanbul suları

Taha Toros Arşivi, Dosya No: 104-Çeşmelerİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Examination of Exercise Addiction Levels of Physical Education Teacher Candidates According to Some Variables

The aim of this study is to examine the levels of exercise addiction of students studying in Physical Education Teaching Program according to gender and academic success variable. The research group consists of 50 students studying in the first class of Mardin Artuklu University, School of Physical Education and Sports, Physical Education Teaching Program in the 2019-2020 academic year. “Exercise Addiction Scale” was used as a data collection tool. The academic success levels of the students are taken from the university's automation system. It was determined that more than half of the participants (%52,0) were addicted to exercise. The addiction scores of male students were higher than female students. A low negative correlation was found between gender and exercise addiction scores. A low level of positive correlation was found between academic success and exercise addiction. As a result; A positive, albeit low, relationship was found between academic success and exercise addiction

The effects of autophagy genes on ageing

Thesis (Master)--Izmir Institute of Technology, Molecular Biology and Genetics, Izmir, 2011Includes bibliographical references (leaves: 25-32)Text in English; Abstract: Turkish and Englishx, 33 leavesAutophagy is defined as a catabolic bulk degradation pathway. In S.cerevisiae autophagy is defined as a single cell's adaptation to starvation. Ageing can be defined as a gradual and progressive deterioration of the health by the time. S.cerevisiae is one of the most important model organism in the field of ageing studies. It has been demonstrated that in different model organisms cellular ageing requires inhibiton of particular nutrient sensing pathways leads to extension or shorten replicative and chronological life span that would be linked by regulation of autophagic pathway. In our study, we screened 29 deletion mutants of autophagy genes in order to determine relation between autophagy and ageing. We found out that 6 mutants showed reduced replicative life span. Furthermore, possible roles of boric acid, as an autophagy inducer was elucidated on replicative and chronological life span. Boric acid did not incerease replicative or chronological life span, in oppose, it shortened life span in a dosedependent manner. Finally, to find out the link between autophagy and oxidative stress, we tested autophagy deficient cells for their hydrogen peroxide sensitivity. Absence of only five mutants rendered cells hydrogen peroxide sensitive. Overall, our results revealed that several mutants of autophagy related paths have shorter life spans compared to wild type cells and cells need to have an intact autophagy systems to benefit from life span extension

Evaluating Repairs and Interventions of the Fethiye Camii through the Perspective of Contemporary Conservation Ethics and Principles

Fethiye Camii is located in Istanbul in the Fatih district amidst the historic neighborhood of Çarşamba. The current structure is comprised of the churches of the Monastery of Pammakaristos in the XIV. Regio built during the Byzantine period. From the monastery, nothing but two churches, four cisterns and a burial chamber survive. In the Ottoman rule, Pammakaristos was first in use as a monastery for nuns and a little later it was put in use as the Greek Patriarchate. At the end of the 16th century, the churches of the monastery were converted to a mosque called Fethiye to commemorate the conquest of Azerbaijan and Georgia. The monument has come to our day under this name. In 1963, a section of the monument was inaugurated as the Fethiye Museum. Fethiye Camii has possessed various identities and has served many functions and communities over time. Currently the monument presents complex problems of architectural history and conservation. Multiple repairs throughout its long history have resulted in various transformations in its physical appearance. The very recent restoration work begun in the museum section in April 2018 has demonstrated the necessity of evaluating the monument’s state of preservation. This article examines its past repairs according to internationally accepted values and puts a special emphasis on 20th century repairs.İstanbul İli, Fatih İlçesi, Katip Musluhittin Mahallesi’nde yer alan Fethiye Camii, Çarşamba olarak bilinen tarihi semtte konumlanır. Yapı, Bizans Dönemi’nde kentin XIV. bölgesinde yer alan Pammakaristos Manastırı’nın kiliselerinden dönüştürülmüştür. İki kilise, dört sarnıç ve bir de mezar odası dışında hiçbir yapısı günümüze ulaşamayan Pammakaristos, İstanbul’un fethinin ardından önce kadınlar manastırı, sonra patrikhane olarak kullanılmıştır. Manastırın kiliseleri 16. yy. sonunda Azerbaycan ve Gürcistan’ın fethi anısına “Fethiye” ismiyle camiye çevrilmiş ve yapı günümüze kadar bu isimle gelmiştir. Ancak 1963’te bir bölümü “Fethiye Müzesi” olarak işlev kazanmıştır. Fethiye Camii zaman içinde çeşitli kimlik ve işlevlere sahip olmuş, birçok topluluğa hizmet etmiş bir yapı olarak, günümüzde karmaşık mimarlık tarihi ile çok çeşitli koruma sorunlarıyla yüz yüzedir. Uzun tarihi boyunca geçirmiş olduğu birçok onarım, fiziksel görünümünde çeşitli dönüşümler ile sonuçlanmış ve 2018 Nisan ayı içinde müze bölümünde başlayan restorasyon, yapının mevcut durumunun ve geçmiş onarımlarının değerlendirilmesini gündeme taşımıştır. Makale kapsamında bu onarımlar ele alınmakta ve yapının son yüzyılı özel bir vurgu ile değerlendirilmektedir

Real-Time Diffraction Field Calculation Methods for Computer-Generated Holograms

Holographic three-dimensional television systems provide a natural 3D visualization. Fast calculation of the diffraction field from a three-dimensional object is essential to achieve video rate. In the literature, there are myriads of fast algorithms for diffraction field calculation from three-dimensional objects, but most of them omit the pixelated structure of the dynamic display devices which are used in the reconstruction process. In this chapter, the look-up table-based fast algorithm for diffraction field calculation from a three-dimensional object for a pixelated dynamic display device is presented. Real-time diffraction field calculations are obtained by running the algorithm in parallel on a graphical processing unit. Performance of the algorithm is evaluated in terms of computation time of the diffraction field and the normalized mean square error on the reconstructed object. To have optimization on the required memory space for the look-up table, two different sampling policies along the longitudinal axis are implemented. Uniform sampling policy along the longitudinal axis provides better error performance than nonuniform sampling policy. Furthermore, optical experiments are performed, and it is observed that both numerical and optical reconstructions are similar to each other. Hence, the proposed method provides successful results

Analyzing a novice teacher’s instructional actions in response to unexpected moments in teaching

International audienceThis study investigated instructional actions of a novice teacher in 6th grade mathematics classrooms during unexpected moments of teaching. The teacher was selected as a case due to her commitment to lesson planning and her interest in creating meaningful mathematical discussions. Unexpected moments of teaching are defined as moments when there is an interruption to the lesson planning. These moments are significant as how teachers notice and decide to act in these moments may determine the quality of instruction. The analyses of lesson planning meetings, lesson observations and interviews with the teacher revealed only three cases of unexpected moments as she taught algebra. The results indicated that unexpected moments of teaching in the form of student questions and responses helped the teacher reflect for future lessons. The instructional actions during these moments had the potential to support and extend student thinking

Dimensions of Political Representation: Ideological and Policy Congruence between the Representative and the Represented in Seven Countries

Based on the understanding that modern democracies must be representative and that this is not only necessary but also desirable, this paper exploits a unique data set which makes comparisons of citizens and their parliamentary representatives on a number of dimensions possible at two points in time (roughly six years apart). The data allows us to comparatively evaluate three dimensions of congruence: ideology, economic policy, and democratic values. We have found that the levels of congruence for the first two dimensions is remarkably high while the popular demand for democracy is significantly lagging behind. Finally, we have failed to demonstrate a positive correlation between quality of democracy and levels of congruence

A CASE STUDY OF TERRESTRIAL LASER SCANNING FOR URBAN CONSERVATION STUDIO AT ÇARŞAMBA NEIGHBOURHOOD IN ISTANBUL

The proper approach of heritage preservation starts with understanding its values and respecting its authenticity and integrity. This requests detailed records and analyses which in principally can be conducted using traditional methods with classical tools or using advanced technological tools.Currently, advantages of using new technologies have been welcomed by the heritage preservation courses at universities. This paper aims to present the implementation of the 3D laser scanning in a graduate studio in urban conservation at FSMVU (Fatih Sultan Mehmet Vakıf University) in Istanbul, with all potentials and limitations. In particular, the process of creating a point cloud by 3D laser scanner Faro Focus 150 S and producing orthographic figures for documentation, for selected streets in the historic neighborhood of Çarşamba at Fener-Balat in Istanbul will be explained. The use of the 3D laser scanning was especially beneficial where the classical tools for documentation couldn’t bring satisfing results. This paper by comparing classical tools and 3D laser scanning techniques tries to identify all the advantages and disadvantages of the new technology and the difference in the quality of the obtained result