131,827 research outputs found
Polymer Translocation througha Pore in a Membrane
We construct a new statistical physical model of polymer translocation
through a pore in a membrane treated as the diffusion process across a free
energy barrier. We determine the translocation time in terms of chain
flexibility yielding an entropic barrier, as well as in terms of the driving
mechanisms such as transmembrane chemical potential difference and Brownian
ratchets. It turns out that, while the chemical potential differences induce
pronounced effects on translocation due to the long-chain nature of the
polymer, the ratchets suppress this effect and chain flexibility.Comment: 4 pages, 5 figures, published in Phys. Rev. Lett. 77, 783(1996
D1 and D5-Brane Actions in AdS_m x S^n
The kappa-invariant and supersymmetric actions of D1 and D5-branes in AdS_3 x
S^3 are investigated, as well as the action of a D5-brane in an AdS_5 x S^5
background. The action of a D5-brane lying totally in an AdS_3 x S^3 background
is found. Some progress was made towards finding the action for the D5-brane
free to move in the whole AdS_3 x S^3 x T^4 space, however the supersymmetric
action found here is not kappa-invariant and the reasons the method used did
not find a kappa-invariant solution are discussed.Comment: 17pp, Latex, improved explanations, a definition adde
Reconstructing a pure state of a spin s through three Stern-Gerlach measurements: II
The density matrix of a spin s is fixed uniquely if the probabilities to obtain the value s upon measuring n.S are known for 4s(s+1) appropriately chosen directions n in space. These numbers are just the expectation values of the density operator in coherent spin states, and they can be determined in an experiment carried out with a Stern-Gerlach apparatus. Furthermore, the experimental data can be inverted providing thus a parametrization of the statistical operator by 4s(s+1) positive parameters
Clinical exome performance for reporting secondary genetic findings.
BACKGROUND
:
Reporting clinically actionable incidental
genetic findings in the course of clinical exome testing is
recommended by the American College of Medical Genet-
ics and Genomics (ACMG). However, the performance of
clinical exome methods for reporting small subsets of genes
has not been previously reported.
METHODS
:
In this study, 57 exome data sets performed as
clinical (n
!
12) or research (n
!
45) tests were retrospec-
tively analyzed. Exome sequencing data was examined for
adequacy in the detection of potentially pathogenic variant
locations in the 56 genes described in the ACMG incidental
findings recommendation. All exons of the 56 genes were
examined for adequacy of sequencing coverage. In addition,
nucleotide positions annotated in HGMD (Human Gene
Mutation Database) were examined.
RESULTS
:
The 56 ACMG genes have 18336 nucleotide
variants annotated in HGMD. None of the 57 exome
data sets possessed a HGMD variant. The clinical exome
test had inadequate coverage for
"
50% of HGMD vari-
ant locations in 7 genes. Six exons from 6 different genes
had consistent failure across all 3 test methods; these
exons had high GC content (76%–84%).
CONCLUSIONS
:
The use of clinical exome sequencing
for the interpretation and reporting of subsets of genes
requires recognition of the substantial possibility of
inadequate depth and breadth of sequencing coverage
at clinically relevant locations. Inadequate depth of
coverage may contribute to false-negative clinical ex-
ome results
Eta invariants with spectral boundary conditions
We study the asymptotics of the heat trace \Tr\{fPe^{-tP^2}\} where is
an operator of Dirac type, where is an auxiliary smooth smearing function
which is used to localize the problem, and where we impose spectral boundary
conditions. Using functorial techniques and special case calculations, the
boundary part of the leading coefficients in the asymptotic expansion is found.Comment: 19 pages, LaTeX, extended Introductio
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