3,151 research outputs found
Computational neuroanatomy and co-expression of genes in the adult mouse brain, analysis tools for the Allen Brain Atlas
We review quantitative methods and software developed to analyze
genome-scale, brain-wide spatially-mapped gene-expression data. We expose new
methods based on the underlying high-dimensional geometry of voxel space and
gene space, and on simulations of the distribution of co-expression networks of
a given size. We apply them to the Allen Atlas of the adult mouse brain, and to
the co-expression network of a set of genes related to nicotine addiction
retrieved from the NicSNP database. The computational methods are implemented
in {\ttfamily{BrainGeneExpressionAnalysis}}, a Matlab toolbox available for
download.Comment: 25 pages, 8 figures, accepted in Quantitative Biology (2012) 000
Taylor-Lagrange renormalization scheme. Application to light-front dynamics
The recently proposed renormalization scheme based on the definition of field
operators as operator valued distributions acting on specific test functions is
shown to be very convenient in explicit calculations of physical observables
within the framework of light-front dynamics. We first recall the main
properties of this procedure based on identities relating the test functions to
their Taylor remainder of any order expressed in terms of Lagrange's formulae,
hence the name given to this scheme. We thus show how it naturally applies to
the calculation of state vectors of physical systems in the covariant
formulation of light-front dynamics. As an example, we consider the case of the
Yukawa model in the simple two-body Fock state truncation.Comment: 18 pages, 6 figures, introduction changed, corrected typos, to be
published in Physical Review
Revisiting the Naturalness Problem -- Who is afraid of quadratic divergences? --
It is widely believed that quadratic divergences severely restrict natural
constructions of particle physics models beyond the standard model (SM).
Supersymmetry provides a beautiful solution, but the recent LHC experiments
have excluded large parameter regions of supersymmetric extensions of the SM.
It will now be important to reconsider whether we have been misinterpreting the
quadratic divergences in field theories. In this paper, we revisit the problem
from the viewpoint of the Wilsonian renormalization group and argue that
quadratic divergences, which can always be absorbed into a position of the
critical surface, should be simply subtracted in model constructions. Such a
picture gives another justification to the argument that the scale invariance
of the SM, except for the soft-breaking terms, is an alternative solution to
the naturalness problem. It also largely broadens possibilities of model
constructions beyond the SM since we just need to take care of logarithmic
divergences, which cause mixings of various physical scales and runnings of
couplings.Comment: 22 pages, 6 figures, version published in Phys. Rev.
The changing perception of women's role in society : a study (1974-1978)
Includes bibliographical references.There can be no doubt that, in our society today, women have been working hard to advance and better their situation in the home, in the schools, and in the workplace. As early as 1647, Margaret Brent went before the Maryland Assembly to demand that women be given a “place and voyce” in their meetings. In 1848, in Seneca Falls, New York, the first convention on women’s rights took place. In 1920, women were given the right to vote. Throughout the 1960’s and 1970’s legislation such as the Civil Rights Act of 1964 was passed. This particular act prohibited job discrimination based on sex. There has been a great push for women’s rights in our country that has brought about an obvious change in the public’s attitude towards the woman and her role in society. It was only a few years ago that we, as a nation, came only three states short of passing the Equal Rights Amendment giving full and equal rights to women. Only sixty-five years ago, women could not even vote! There can be no doubt that attitudes are changing on this important issue
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