23,585 research outputs found
Consistent Estimation of Low-Dimensional Latent Structure in High-Dimensional Data
We consider the problem of extracting a low-dimensional, linear latent
variable structure from high-dimensional random variables. Specifically, we
show that under mild conditions and when this structure manifests itself as a
linear space that spans the conditional means, it is possible to consistently
recover the structure using only information up to the second moments of these
random variables. This finding, specialized to one-parameter exponential
families whose variance function is quadratic in their means, allows for the
derivation of an explicit estimator of such latent structure. This approach
serves as a latent variable model estimator and as a tool for dimension
reduction for a high-dimensional matrix of data composed of many related
variables. Our theoretical results are verified by simulation studies and an
application to genomic data
Different thermodynamic pathways to the solvation free energy of a spherical cavity in a hard sphere fluid
This paper determines the excess free energy associated with the formation of
a spherical cavity in a hard sphere fluid. The solvation free energy can be
calculated by integration of the structural changes induced by inserting the
cavity using a number of different exact thermodynamic pathways. We consider
three such pathways, including a new density route derived here. Structural
information about the nonuniform hard sphere fluid in the presence of a general
external field is given by the recently developed hydrostatic linear response
(HLR) integral equation. Use of the HLR results in the different pathways gives
a generally accurate determination of the solvation free energy for cavities
over a wide range of sizes, from zero to infinity. Results for a related
method, the Gaussian Field Model, are also discussed.Comment: 10 pages, 4 figures; submitted to J. Chem. Phy
Transposase mapping identifies the genomic targets of BAP1 in uveal melanoma
Table summarizing the RNA-seq results. Differential gene expression results in BAP1-knockdown compared to control OCM-1A cells are shown from the RNA-seq data. Each row gives the unique Ensembl identifier, gene name, and description for each gene, as well as the log of the fold change (logFC), average expression, adjusted p-value, and linear fold change. (XLSX 1392 kb
MgB2 tunnel junctions and 19 K low-noise dc superconducting quantum interference devices
Point contact junctions made from two pieces of MgB2 can be adjusted to
exhibit either superconductor-insulator-superconductor (SIS) or
superconductor-normal metal-superconductor (SNS) current-voltage
characteristics. The SIS characteristics are in good agreement with the
standard tunneling model for s-wave superconductors, and yield an energy gap of
(2.02 +/- 0.08) meV. The SNS characteristics are in good agreement with the
predictions of the resistively-shunted junction model. DC Superconducting
QUantum Interference Devices made from two SNS junctions yield magnetic field
noise as low as 35 fT/Hz^{1/2} at 19 K.Comment: 4 pages, 4 figure
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