2,028 research outputs found

    AdS/BCFT Correspondence for Higher Curvature Gravity: An Example

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    We consider the effects of higher curvature terms on a holographic dual description of boundary conformal field theory. Specifically, we consider three-dimensional gravity with a specific combination of Ricci tensor square and curvature scalar square, so called, new massive gravity. We show that a boundary entropy and an entanglement entropy are given by similar expression with those of the Einstein gravity case when we introduce an {\it effective} Newton's constant and an {\it effective} cosmological constant. We also show that the holographic g-theorem still holds in this extension, and we give some comments about the central charge dependence of boundary entropy in the holographic construction. In the same way, we consider new type black holes and comment on the boundary profile. Moreover, we reproduce these results through auxiliary field formalism in this specific higher curvature gravity.Comment: 27pages, minor corrections, accepted in JHE

    AdS Black Hole Solutions in the Extended New Massive Gravity

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    We have obtained (warped) AdS black hole solutions in the three dimensional extended new massive gravity. We investigate some properties of black holes and obtain central charges of the two dimensional dual CFT. To obtain the central charges, we use the relation between entropy and temperature according to the AdS/CFT dictionary. For AdS black holes, one can also use the central charge function formalism which leads to the same results.Comment: 24pages, some organization corrected, minor corrections, references added, final published versio

    Holographic Renormalization and Stress Tensors in New Massive Gravity

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    We obtain holographically renormalized boundary stress tensors with the emphasis on a special point in the parameter space of three dimensional new massive gravity, using the so-called Fefferman-Graham coordinates with relevant counter terms. Through the linearized equations of motion with a standard prescription, we also obtain correlators among these stress tensors. We argue that the self-consistency of holographic renormalization determines counter terms up to unphysical ambiguities. Using these renormalized stress tensors in Fefferman-Graham coordinates, we obtain the central charges of dual CFT, and mass and angular momentum of some AdSAdS black hole solutions. These results are consistent with the previous ones obtained by other methods. In this study on the Fefferman-Graham expansion of new massive gravity, some aspects of higher curvature gravity are revealed.Comment: Version accepted for publication in JHEP, conclusion revised, references adde

    Sampling of An.gambiae s.s mosquitoes using Limburger cheese, heat and moisture as baits in a homemade trap

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    <p>Abstract</p> <p>Background</p> <p>Ample evidence has shown that odour baited traps are likely to provide an objective monitoring tool for the host-seeking fraction of mosquito vectors of diseases like malaria and bancroftian filariasis. Such traps could eventually become part of primary healthcare systems used to study the vector biology and epidemiology of mosquito-borne diseases. I hereby, report a study that sampled <it>Anopheles gambiae sensu stricto </it>mosquitoes in a screen house using a homemade trap baited with a combination of Limburger cheese and moisture, Limburger cheese and heat, or Limburger cheese, moisture and heat.</p> <p>Findings</p> <p>Tests on the efficacy of the developed trap to sample <it>An. gambiae s.s</it>, mosquitoes using Limburger cheese, moisture and heat as baits were carried out in a screen house measuring 11.4 Ă— 7.1 Ă— 2.8 m. The studies were done in three phases. In the first phase the efficacy of the trap to sample <it>An. gambiae s.s</it>. using odour and moisture was tested. The second phase was to test the efficacy of the trap to sample <it>An. gambiae s.s</it>. using Limburger cheese and heat. In the third phase a combination of Limburger cheese, moisture and heat was tested. Tests were carried out for 27 consecutive nights.</p> <p>The designed trap collected a total of 59 <it>An. gambiae s.s</it>. in three trials. The trap baited with Limburger cheese and moisture collected 7 <it>An. gambiae s.s </it>in 7 days. The mean catch per day was 1. The trap baited with Limburger cheese and heat collected zero <it>An. gambiae s.s </it>in 11 days. The mean catch per day was therefore 0. The trap baited with Limburger cheese, moisture and heat collected 52 mosquitoes in 27 days and the mean catch was 1.93.</p> <p>Conclusions</p> <p>This study indicates that a non-electric fan driven trap baited with a combination of Limburger cheese, heat and moisture has a potential as an effective sampling tool for the malaria vector, <it>Anopheles gambiae s.s</it>. However, further optimization studies would be necessary.</p

    Competition and educational quality: evidence from the Netherlands

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    Little evidence is available for the effect of competition on educational quality as only a few countries allow large-scale competition. In the Netherlands, free parental choice has been present since the beginning of the twentieth century and can be characterized as a full voucher program with 100 % funding. Based on micro panel data for the Netherlands, we show that there is a relation between competition and educational outcomes in secondary education, but that it is often negative and small, sometimes insignificant but never positive. This effect is larger for small and medium-sized schools and for schools that do not have a Protestant or Catholic denomination

    Topological mechanochemistry of graphene

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    In view of a formal topology, two common terms, namely, connectivity and adjacency, determine the quality of C-C bonds of sp2 nanocarbons. The feature is the most sensitive point of the inherent topology of the species so that such external action as mechanical deformation should obviously change it and result in particular topological effects. The current paper describes the effects caused by uniaxial tension of a graphene molecule in due course of a mechanochemical reaction. Basing on the molecular theory of graphene, the effects are attributed to both mechanical loading and chemical modification of edge atoms of the molecule. The mechanical behavior is shown to be not only highly anisotropic with respect to the direction of the load application, but greatly dependent on the chemical modification of the molecule edge atoms thus revealing topological character of the graphene deformation.Comment: 9 pages, 10 figures, 1 table. arXiv admin note: text overlap with arXiv:1301.094

    Methodological issues in cross-cultural research

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    Regardless of whether the research goal is to establish cultural universals or to identify and explain cross-cultural differences, researchers need measures that are comparable across different cultures when conducting cross-cultural studies. In this chapter, we describe two major strategies for enhancing cross-cultural comparability. First, we discuss a priori methods to ensure the comparability of data in cross-cultural surveys. In particular, we review findings on cross-cultural differences based on the psychology of survey response and provide suggestions on how to deal with these cultural differences in the survey design stage. Second, we discuss post hoc methods to ascertain data comparability and enable comparisons in the presence of threats to equivalence
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