23,502 research outputs found
Growth factors in idiopathic pulmonary fibrosis: relative roles
Treatment of idiopathic pulmonary fibrosis patients has evolved very slowly; the fundamental approach of corticosteroids alone or in combination with other immunosuppressive agents has had little impact on long-term survival. The continued use of corticosteroids is justified because of the lack of a more effective alternative. Current research indicates that the mechanisms driving idiopathic pulmonary fibrosis reflect abnormal, dysregulated wound healing within the lung, involving increased activity and possibly exaggerated responses by a spectrum of profibrogenic growth factors. An understanding of the roles of these growth factors, and the way in which they modulate events at cellular level, could lead to more targeted therapeutic strategies, improving patients' quality of life and survival
Constraining Scatter in the Stellar Mass--Halo Mass Relation for Haloes Less Massive than the Milky Way
Most galaxies are hosted by massive, invisible dark matter haloes, yet little
is known about the scatter in the stellar mass--halo mass relation for galaxies
with host halo masses . Using mock catalogues based
on dark matter simulations, we find that two observable signatures are
sensitive to scatter in the stellar mass--halo mass relation even at these mass
scales; i.e., conditional stellar mass functions and velocity distribution
functions for neighbouring galaxies. We compute these observables for 179,373
galaxies in the Sloan Digital Sky Survey (SDSS) with stellar masses and redshifts 0.01 0.307. We then compare to mock
observations generated from the dark matter
simulation for stellar mass--halo mass scatters ranging from 0 to 0.6 dex. The
observed results are consistent with simulated results for most values of
scatter (0.6 dex), and SDSS statistics are insufficient to provide firm
constraints. However, this method could provide much tighter constraints on
stellar mass--halo mass scatter in the future if applied to larger data sets,
especially the anticipated Dark Energy Spectroscopic Instrument Bright Galaxy
Survey. Constraining the value of scatter could have important implications for
galaxy formation and evolution.Comment: 11 pages, 1 table, 9 main body figures, 9 appendix figure
Visual Responses in Mice Lacking Critical Components of All Known Retinal Phototransduction Cascades
The mammalian visual system relies upon light detection by outer-retinal rod/cone photoreceptors and melanopsin-expressing retinal ganglion cells. Gnat1(-/-); Cnga3(-/-); Opn4(-/-) mice lack critical elements of each of these photoreceptive mechanisms via targeted disruption of genes encoding rod alpha transducin (Gnat1); the cone-specific alpha 3 cyclic nucleotide gated channel subunit (Cnga3); and melanopsin (Opn4). Although assumed blind, we show here that these mice retain sufficiently widespread retinal photoreception to drive a reproducible flash electroretinogram (ERG). The threshold sensitivity of this ERG is similar to that of cone-based responses, however it is lost under light adapted conditions. Its spectral efficiency is consistent with that of rod opsin, but not cone opsins or melanopsin, indicating that it originates with light absorption by the rod pigment. The TKO light response survives intravitreal injection of U73122 (a phospholipase C antagonist), but is inhibited by a missense mutation of cone alpha transducin (Gnat2(cpfl3)), suggesting Gnat2-dependence. Visual responses in TKO mice extend beyond the retina to encompass the lateral margins of the lateral geniculate nucleus and components of the visual cortex. Our data thus suggest that a Gnat1-independent phototransduction mechanism downstream of rod opsin can support relatively widespread responses in the mammalian visual system. This anomalous rod opsin-based vision should be considered in experiments relying upon Gnat1 knockout to silence rod phototransduction
A Late Nineteenth - Century Rural Community: Three Homesteads in Sebago, Maine
This thesis examines three homesteads in the small inland farming community of Sebago, Maine. The homesteads are analyzed in terms of architecture and landscape, along with documentary sources such as census returns. Set against the backdrop of the history of the town, and northern rural New England in general, the story of these three houses offers insights into the soacial history of Sebago during this period
Quantum state transfer through a spin chain in a multi-excitation subspace
We investigate the quality of quantum state transfer through a uniformly
coupled antiferromagnetic spin chain in a multi-excitation subspace. The
fidelity of state transfer using multi-excitation channels is found to compare
well with communication protocols based on the ground state of a spin chain
with ferromagnetic interactions. Our numerical results support the conjecture
that the fidelity of state transfer through a multi-excitation subspace only
depends on the number of initial excitations present in the chain and is
independent of the excitation ordering. Based on these results, we describe a
communication scheme which requires little effort for preparation.Comment: 5 pages, 4 figure
Quantum initial condition sampling for linearized density matrix dynamics: Vibrational pure dephasing of iodine in krypton matrices
This paper reviews the linearized path integral approach for computing time
dependent properties of systems that can be approximated using a mixed
quantum-classical description. This approach is applied to studying vibrational
pure dephasing of ground state molecular iodine in a rare gas matrix. The
Feynman-Kleinert optimized harmonic approximation for the full system density
operator is used to sample initial conditions for the bath degrees of freedom.
This extremely efficient approach is compared with alternative initial
condition sampling techniques at low temperatures where classical initial
condition sampling yields dephasing rates that are nearly an order of magnitude
too slow compared with quantum initial condition sampling and experimental
results.Comment: 20 pages and 8 figure
A catalog of Kazarian galaxies
The entire Kazarian galaxies (KG) catalog is presented which combines
extensive new measurements of their optical parameters with a literature and
database search. The measurements were made using images extracted from the
STScI Digitized Sky Survey (DSS) of Jpg(blue), Fpg(red) and Ipg(NIR) band
photographic sky survey plates obtained by the Palomar and UK Schmidt
telescopes. We provide accurate coordinates, morphological type, spectral and
activity classes, blue apparent diameters, axial ratios, position angles, red,
blue and NIR apparent magnitudes, as well as counts of neighboring objects in a
circle of radius 50 kpc from centers of KG. Special attention was paid to the
individual descriptions of the galaxies in the original Kazarian lists, which
clarified many cases of misidentifications of the objects, particularly among
interacting systems. The total number of individual Kazarian objects in the
database is now 706. We also include the redshifts which are now available for
404 galaxies and the 2MASS infrared magnitudes for 598 KG. The database also
includes extensive notes, which summarize information about the membership of
KG in different systems of galaxies, and about revised activity classes and
redshifts. An atlas of several interesting subclasses of KG is also presented.Comment: 15 pages, 5 figures, 1 table, Accepted in Astrophysics, Vol. 53, No.
1, 2010 (English translation of Astrofizika
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