718 research outputs found
A Minimum-Labeling Approach for Reconstructing Protein Networks across Multiple Conditions
The sheer amounts of biological data that are generated in recent years have
driven the development of network analysis tools to facilitate the
interpretation and representation of these data. A fundamental challenge in
this domain is the reconstruction of a protein-protein subnetwork that
underlies a process of interest from a genome-wide screen of associated genes.
Despite intense work in this area, current algorithmic approaches are largely
limited to analyzing a single screen and are, thus, unable to account for
information on condition-specific genes, or reveal the dynamics (over time or
condition) of the process in question. Here we propose a novel formulation for
network reconstruction from multiple-condition data and devise an efficient
integer program solution for it. We apply our algorithm to analyze the response
to influenza infection in humans over time as well as to analyze a pair of ER
export related screens in humans. By comparing to an extant, single-condition
tool we demonstrate the power of our new approach in integrating data from
multiple conditions in a compact and coherent manner, capturing the dynamics of
the underlying processes.Comment: Peer-reviewed and presented as part of the 13th Workshop on
Algorithms in Bioinformatics (WABI2013
On the state of low luminous accreting neutron stars
Observational appearance of a neutron star in the subsonic propeller state
which is a companion of a wind-fed mass-exchange close binary system is
discussed. During the subsonic propeller state the neutron star magnetosphere
is surrounded by a spherical quasi-static plasma envelope, which is extended
from the magnetospheric boundary up to the star accretion radius. The energy
input to the envelope due to the propeller action by the neutron star exceeds
the radiative losses and the plasma temperature in the envelope is of the order
of the free-fall temperature. Under this condition the magnetospheric boundary
is interchange stable. Nevertheless, I find that the rate of plasma penetration
from the envelope into the magnetic field of the neutron star due to diffusion
and magnetic field line reconnection processes is large enough for the
accretion power to dominate the spindown power. I show that the accretion
luminosity of the neutron star in the subsonic propeller state is 5*10**{30} -
10**{33} (dM/dt)_{15} erg/s, where dM/dt is the strength of the normal
companion stellar wind which is parametrized in terms of the maximum possible
mass accretion rate onto the neutron star magnetosphere. On this basis I
suggest that neutron stars in the subsonic propeller state are expected to be
observed as low luminous accretion-powered pulsars. The magnetospheric radius
of the neutron star in this state is determined by the strength of the stellar
wind, (dM/dt)_c, while the accretion luminosity is determined by the rate of
plasma penetration into the star magnetosphere, (dM/dt)_a, which is (dM/dt)_a
<< (dM/dt)_c. That is why the classification of the neutron star state in these
objects using the steady accretion model (i.e. setting (dM/dt)_a = (dM/dt)_c)
can lead to a mistaken conclusion.Comment: 6 pages, accepted for publication in A&
Liquid phase immunoassay utilizing magnetic marker and high Tc superconducting quantum interference device
We have developed a liquid phase immunoassay system utilizing a magnetic marker and a superconducting quantum interference device (SQUID). In this system, the magnetic marker was used to detect the biological material called antigen. The magnetic marker was designed so as to generate a remanence, and the remanence field of the markers that bound to the antigens was measured with the SQUID. The measurement was performed in a solution that contained both the bound and free (or unbound) markers, i.e., without using the so-called bound/free (BF) separation process. The Brownian rotation of the free markers in the solution was used to distinguish the bound markers from the free ones. Using the system, we conducted the detection of biological material called IgE without BF separation. At present, we could detect the IgE down to 7 pg (or 39 amol
Electric polarization induced by Neel order without magnetic superlattice: experimental study of Cu3Mo2O9 and numerical study of a small spin cluster
We clarify that the antiferromagnetic order in the distorted tetrahedral
quasi-one dimensional spin system induces electric polarizations. In this
system, the effects of the low dimensionality and the magnetic frustration are
expected to appear simultaneously. We obtain the magnetic-field-temperature
phase diagram in Cu3Mo2O9 by studying the dielectric constant and the
spontaneous electric polarization. Around the tricritical point at 10 T and 8
K, the change of the direction in the electric polarization causes a colossal
magnetocapacitance. We calculate the charge redistribution in the small spin
cluster consisting of two magnetic tetrahedra to demonstrate the electric
polarization induced by the antiferromagnetism.Comment: 10 pages 6 figures, in press in J. Phys. Soc. Jp
Mass-Enhanced Fermi Liquid Ground State in NaCoO
Magnetic, transport, and specific heat measurements have been performed on
layered metallic oxide NaCoO as a function of temperature .
Below a characteristic temperature =3040 K, electrical resistivity
shows a metallic conductivity with a behavior and magnetic susceptibility
deviates from the Curie-Weiss behavior showing a broad peak at 14 K. The
electronic specific heat coefficient is 60 mJ/molK at 2 K.
No evidence for magnetic ordering is found. These behaviors suggest the
formation of mass-enhanced Fermi liquid ground state analogous to that in
-electron heavy fermion compound LiVO.Comment: 4 pages, 4 figures, to be published in Phys. Rev. B 69 (2004
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Theoretical studies of EBT
A one-dimensional time dependent model of plasma particle and energy transport was used to predict the performance of an EBT experiment large enough to test confinement scaling in a parameter range (n, T, tau, etc.) close to reactor conditions. Such a device is referred to as EBT-P. The model is based on a computer code which uses the magnetic field lines as the basis for the coordinate system, and so includes some EBT geometrical effects, with neoclassical transport perpendicular to the surfaces of constant pressure. The geometry is self-consistent, i.e., the plasma pressure reacts on the magnetic field
Search for Charmless Two-body Baryonic Decays of B Mesons
We report the results of a search for the rare baryonic decays , , and . The analysis
is based on a data set of events collected by the
Belle detector at the KEKB collider. No statistically significant
signals are found, and we set branching fraction upper limits , , and at the 90% confidence level.Comment: 6 pages, 4 figures and 1 table. Submitted to Phys. Rev. D Rapid
Communication
Observation of chi_c2 Production in B-meson Decay
We report the first observation of chi_c2 production in B-meson decays. We
find an inclusive B -> chi_c2 X branching fraction of (1.80^{+0.23}_{-0.28}+/-
0.26) 10^-3. The data set, collected with the Belle detector at the KEKB e^+e^-
collider, consists of 31.9 million B\bar B events. We also present branching
fractions and momentum spectra for both chi_c1 and chi_c2 production.Comment: 5 pages with 2 figure
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