52,747 research outputs found
A Rotating Charged Black Hole Solution in f(R) Gravity
In the context of f(R) theories of gravity, we address the problem of finding
a rotating charged black hole solution in the case of constant curvature. The
new metric is obtained by solving the field equations and we show that the
behavior of it is typical of a rotating charged source. In addition, we analyze
the thermodynamics of the new black hole. The results ensures that the
thermodynamical properties in f(R) gravities are qualitatively similar to those
of standard General Relativity.Comment: 9 pages, no figure
The duality diagram in data analysis: Examples of modern applications
Today's data-heavy research environment requires the integration of different
sources of information into structured data sets that can not be analyzed as
simple matrices. We introduce an old technique, known in the European data
analyses circles as the Duality Diagram Approach, put to new uses through the
use of a variety of metrics and ways of combining different diagrams together.
This issue of the Annals of Applied Statistics contains contemporary examples
of how this approach provides solutions to hard problems in data integration.
We present here the genesis of the technique and how it can be seen as a
precursor of the modern kernel based approaches.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS408 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The early stages of heart development: insights from chicken embryos
The heart is the first functioning organ in the developing embryo and the detailed understanding of the molecular and cellular mechanisms involved in its formation provides insights into congenital malformations affecting its function and therefore the survival of the organism. Because many developmental mechanisms are highly conserved, it is possible to extrapolate from observations made in invertebrate and vertebrate model organisms to human. This review will highlight the contributions made through studying heart development in avian embryos, particularly the chicken. The major advantage of chick embryos is their accessibility for surgical manipulations and functional interference approaches, both gain- and loss-of-function. In addition to experiments performed in ovo, the dissection of tissues for ex vivo culture, genomic or biochemical approaches, is straightforward. Furthermore, embryos can be cultured for time-lapse imaging, which enables tracking of fluorescently labeled cells and detailed analyses of tissue morphogenesis. Owing to these features, investigations in chick embryos have led to important discoveries, often complementing genetic studies in mouse and zebrafish. As well as including some historical aspects, we cover here some of the crucial advances made in understanding of early heart development using the chicken model
Some new results on the self-dual [120,60,24] code
The existence of an extremal self-dual binary linear code of length 120 is a
long-standing open problem. We continue the investigation of its automorphism
group, proving that automorphisms of order 30 and 57 cannot occur. Supposing
the involutions acting fixed point freely, we show that also automorphisms of
order 8 cannot occur and the automorphism group is of order at most 120, with
further restrictions. Finally, we present some necessary conditions for the
existence of the code, based on shadow and design theory.Comment: 23 pages, 6 tables, to appear in Finite Fields and Their Application
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