Friedmann limits of rotating hypersurface-homogeneous dust models

The existence of Friedmann limits is systematically investigated for all the hypersurface-homogeneous rotating dust models, presented in previous papers by this author. Limiting transitions that involve a change of the Bianchi type are included. Except for stationary models that obviously do not allow it, the Friedmann limit expected for a given Bianchi type exists in all cases. Each of the 3 Friedmann models has parents in the rotating class; the k = +1 model has just one parent class, the other two each have several parent classes. The type IX class is the one investigated in 1951 by Goedel. For each model, the consecutive limits of zero rotation, zero tilt, zero shear and spatial isotropy are explicitly calculated.Comment: 39 pages, LaTeX, 1 postscript figure. Subjects: General relativity, exact solutions, cosmolog

Functional specialization and differential regulation of short-chain carboxylic acid transporters in the pathogen Candida albicans

Open Access via PMC2859246Peer reviewe

Stress-induced nuclear accumulation is dispensable for Hog1-dependent gene expression and virulence in a fungal pathogen

The authors thank E. Veal for intellectual input. This work was funded by the UK Biotechnology and Biological Research Council [J.Q. BB/K016393/1; A.J.P.B. BB/K017365/1], the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) [D.M.M. NC/N002482/1] and the Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology [097377]). D.M.M. and A.J.P.B. are also supported by the MRC Centre for Medical Mycology at the University of Aberdeen (MR/N006364/1).Peer reviewedPublisher PD

Riemann-Cartan Space-times of G\"odel Type

A class of Riemann-Cartan G\"odel-type space-times are examined in the light of the equivalence problem techniques. The conditions for local space-time homogeneity are derived, generalizing previous works on Riemannian G\"odel-type space-times. The equivalence of Riemann-Cartan G\"odel-type space-times of this class is studied. It is shown that they admit a five-dimensional group of affine-isometries and are characterized by three essential parameters $\ell, m^2, \omega$: identical triads ($\ell, m^2, \omega$) correspond to locally equivalent manifolds. The algebraic types of the irreducible parts of the curvature and torsion tensors are also presented.Comment: 24 pages, LaTeX fil

Dvali-Gabadadze-Porrati Cosmology in Bianchi I brane

The dynamics of Dvali-Gabadadze-Porrati Cosmology (DGP) braneworld with an anisotropic brane is studied. The Friedmann equations and their solutions are obtained for two branches of anisotropic DGP model. The late time behavior in DGP cosmology is examined in the presence of anisotropy which shows that universe enters a self-accelerating phase much later compared to the isotropic case. The acceleration conditions and slow-roll conditions for inflation are obtained

Property differences among the four major Candida albicans strain clades

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Tachyonic potential in Bianchi type-I universe

Motivated from recent string theoretic results, a tachyonic potential is constructed for a spatially homogeneous and anisotropic background cosmology.Comment: 5 pages,LATEX,Typos in the text corrected, more references adde

Self-similar cosmologies in 5D: spatially flat anisotropic models

In the context of theories of Kaluza-Klein type, with a large extra dimension, we study self-similar cosmological models in 5D that are homogeneous, anisotropic and spatially flat. The "ladder" to go between the physics in 5D and 4D is provided by Campbell-Maagard's embedding theorems. We show that the 5-dimensional field equations $R_{AB} = 0$ determine the form of the similarity variable. There are three different possibilities: homothetic, conformal and "wave-like" solutions in 5D. We derive the most general homothetic and conformal solutions to the 5D field equations. They require the extra dimension to be spacelike, and are given in terms of one arbitrary function of the similarity variable and three parameters. The Riemann tensor in 5D is not zero, except in the isotropic limit, which corresponds to the case where the parameters are equal to each other. The solutions can be used as 5D embeddings for a great variety of 4D homogeneous cosmological models, with and without matter, including the Kasner universe. Since the extra dimension is spacelike, the 5D solutions are invariant under the exchange of spatial coordinates. Therefore they also embed a family of spatially {\it inhomogeneous} models in 4D. We show that these models can be interpreted as vacuum solutions in braneworld theory. Our work (I) generalizes the 5D embeddings used for the FLRW models; (II) shows that anisotropic cosmologies are, in general, curved in 5D, in contrast with FLRW models which can always be embedded in a 5D Riemann-flat (Minkowski) manifold; (III) reveals that anisotropic cosmologies can be curved and devoid of matter, both in 5D and 4D, even when the metric in 5D explicitly depends on the extra coordinate, which is quite different from the isotropic case.Comment: Typos corrected. Minor editorial changes and additions in the Introduction and Summary section

British digital game studies

This paper provides a short and potted recent history of digital games research in Great Britain. We begin this story in 2001. Though a substantial amount of research and writing on digital games was taking in Britain since at least the 1980s, for us the turn of the new millennium makes a logical starting point for our recent history. This is because this was not only the year that Aarseth (2001) marked as 'year one' for 'computer game research', but it was also the year that the first major international conference on digital games took place in the UK (in Bristol), and the first time a major British government grant was awarded to undertake research on digital gaming. The paper then charts the significant role Britain played in hosting major early international gatherings of (now leading) games researchers, such as those in Bristol and also Manchester. As well as the important crop of early British authored (text)books that helped shape the direction of this new emerging discipline. What we then see is a significant growth in British digital games studies focused around a number of key events, research clusters, and publications, and the development of a particular framing of digital games within a wider social, cultural, and political context. It is this, we would suggest, which has given British digital game studies its particular flavour and also its important global role in pushing forward research, theory, and key debates