Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 2 )

2019 ( 562 )

2018 ( 708 )

2017 ( 702 )

Custom range...

Search Results: 1 - 10 of 402316 matches for " Gillern Suzanne M "
All listed articles are free for downloading (OA Articles)
Page 1 /402316
Display every page Item
Lymphocyte Depletion in Experimental Hemorrhagic Shock in Swine
Hawksworth Jason S,Graybill Christopher,Brown Trevor S,Gillern Suzanne M
Journal of Inflammation , 2012, DOI: 10.1186/1476-9255-9-34
Abstract: Background Hemorrhagic shock results in systemic activation of the immune system and leads to ischemia-reperfusion injury. Lymphocytes have been identified as critical mediators of the early innate immune response to ischemia-reperfusion injury, and immunomodulation of lymphocytes may prevent secondary immunologic injury in surgical and trauma patients. Methods Yorkshire swine were anesthetized and underwent a grade III liver injury with uncontrolled hemorrhage to induce hemorrhagic shock. Experimental groups were treated with a lymphocyte depletional agent, porcine polyclonal anti-thymocyte globulin (PATG) (n = 8) and compared to a vehicle control group (n = 9). Animals were observed over a 3 day survival period. Circulating lymphocytes were examined with FACS analysis for CD3/CD4/CD8, and central lymphocytes with mesenteric lymph node and spleen staining for CD3. Circulating and lung tissue16 infiltrating neutrophils were measured. Circulating CD3 lymphocytes in the blood and in central lymphoid organs (spleen/lymph node) were stained and evaluated using FACS analysis. Immune-related gene expression from liver tissue was quantified using RT-PCR. Results The overall survival was 22% (2/9) in the control and 75% (6/8) in the PATG groups, p = 0.09; during the reperfusion period (following hemorrhage) survival was 25% (2/8) in the control and 100% (6/6) in the PATG groups, p = 0.008. Mean blood loss and hemodynamic profiles were not significantly different between the experimental and control groups. Circulating CD3+CD4+ lymphocytes were significantly depleted in the PATG group compared to control. Lymphocyte depletion in the setting of hemorrhagic shock also significantly decreased circulating and lung tissue infiltrating neutrophils, and decreased expression of liver ischemia gene expression. Conclusions Lymphocyte manipulation with a depletional (PATG) strategy improves reperfusion survival in experimental hemorrhagic shock using a porcine liver injury model. This proof of principle study paves the way for further development of immunomodulation approaches to ameliorate secondary immune injury following hemorrhagic shock.
A Tribute to Marcy Carlson Speer, 1959–2007
Suzanne M Leal
PLOS Genetics , 2007, DOI: 10.1371/journal.pgen.0030230
Viscosity solutions associated with impulse control problems for piecewise-deterministic processes
Suzanne M. Lenhart
International Journal of Mathematics and Mathematical Sciences , 1989, DOI: 10.1155/s0161171289000207
Abstract: This paper considers existence and uniqueness results for viscosity solutions of integro-differential equations associated with the impulse control problem for piecewise-deterministic processes on bounded domains and on Rn.
Effects of Galaxy Selection Upon Lyman Alpha Absorber Identification
Suzanne M. Linder
Physics , 1997,
Abstract: While it is possible to explain Lyman alpha absorber counts at low redshift using gas which is associated with moderately extended galaxies (Linder 1997), absorbers are often observed to be associated with galaxies at larger impact parameters from quasar lines of sight than are expected from calculated galaxy absorption cross sections in such absorber-galaxy models. However, a large fraction of absorbers is expected to arise in lines sight through galaxies which are low in luminosity and/or surface brightness, so that they are unlikely to be detected in surveys for galaxies close to quasar lines of sight. Given that it is impossible to be certain that any particular absorber has been matched to the correct galaxy, I show that it is possible to simulate plots of absorption covering factors around luminous galaxies which resemble observed plots by assuming that absorption often originates in unidentified galaxies.
Comparing Galaxies and Lyman Alpha Absorbers at Low Redshift
Suzanne M. Linder
Physics , 1997, DOI: 10.1086/305332
Abstract: A scenario is explored in which Lyman alpha absorbers at low redshift arise from lines of sight through extended galaxy disks, including those of dwarf and low surface brightness galaxies. A population of galaxies is simulated based upon observed distributions of galaxy properties, and the gas disks are modeled using pressure and gravity confinement. Some parameter values are ruled out by comparing simulation results with the observed galaxy luminosity function, and constraints may be made on the absorbing cross sections of galaxies. Simulation results indicate that it is difficult to match absorbers with particular galaxies observationally since absorption typically occurs at high impact parameters (>200 kpc) from luminous galaxies. Low impact parameter absorption is dominated by low luminosity dwarfs. A large fraction of absorption lines is found to originate from low surface brightness galaxies, so that the absorbing galaxy is likely to be misidentified. Low redshift Lyman alpha absorber counts can easily be explained by moderately extended galaxy disks when low surface brightness galaxies are included, and it is easily possible to find a scenario which is consistent with observed the galaxy luminosity function, with low redshift Lyman limit absorber counts, and with standard nucleosynthesis predictions of the baryon density, Omega_Baryon.
Viscoelastic Taylor-Couette instability of shear banded flow
Suzanne M. Fielding
Physics , 2009, DOI: 10.1103/PhysRevLett.104.198303
Abstract: We study numerically shear banded flow in planar and curved Couette geometries. Our aim is to explain two recent observations in shear banding systems of roll cells stacked in the vorticity direction, associated with an undulation of the interface between the bands. Depending on the degree of cell curvature and on the material's constitutive properties, we find either (i) an instability of the interface between the bands driven by a jump in second normal stress across it; or (ii) a bulk viscoelastic Taylor Couette instability in the high shear band driven by a large first normal stress within it. Both lead to roll cells and interfacial undulations, but with a different signature in each case. Our work thereby suggests a different origin for the roll cells in each of the recent experiments.
The need for inertia in nonequilibrium steady states of sheared binary fluids
Suzanne M. Fielding
Physics , 2007, DOI: 10.1103/PhysRevE.77.021504
Abstract: We study numerically phase separation in a binary fluid subject to an applied shear flow in two dimensions, with full hydrodynamics. To do so, we introduce a mixed finite-differencing/spectral simulation technique, with a transformation to render trivial the implementation of Lees-Edwards sheared periodic boundary conditions. For systems with inertia, we reproduce the nonequilibrium steady states reported in a recent lattice Boltzmann study. The domain coarsening that would occur in zero shear is arrested by the applied shear flow, which restores a finite domain size set by the inverse shear rate. For inertialess systems, in contrast, we find no evidence of nonequilibrium steady states free of finite size effects: coarsening persists indefinitely until the typical domain size attains the system size, as in zero shear. We present an analytical argument that supports this observation, and that furthermore provides a possible explanation for a hitherto puzzling property of the nonequilibrium steady states with inertia.
Comparing Low Surface Brightness Galaxies and Ly$α$ Absorbers
Suzanne M. Linder
Physics , 1996,
Abstract: I explore the hypothesis that Ly$\alpha$ absorption at low redshift is caused by the outer regions of extended galaxy disks, including those of dwarf and low surface brightness galaxies. McGaugh (1996) has shown that the distribution of central galaxy surface brightnesses may be flat to 25 B mag arcsec$^{-2}$ or fainter. A population of galaxies is simulated based upon observed distributions. The low-redshift neutral column density distribution is predicted, and an estimate is made for the number density of disk galaxies required to explain all absorbers. Results relating to galaxy luminosities and impact parameters are discussed.
Simulations of LyαAbsorption from Low Surface Brightness Galaxies
Suzanne M. Linder
Physics , 1998,
Abstract: Using simulations of the low redshift galaxy population based upon galaxy observations, it is shown (Linder 1998) that the majority of Ly$\alpha$ absorbers at low redshift could arise in low surface brightness (LSB) galaxies. The contribution to absorption from LSB galaxies is large for any galaxy surface brightness distribution which is currently supported by observations. Ly\alpha absorbers should become powerful tools for studying the properties and evolution of galaxies, but first it will be necessary to establish observationally the nature of the Ly\alpha absorbers at low redshift. Further simulations, in which the absorbing galaxy population is 'observed' with some selection criteria, are used to explore how easily possible it is for an observer to test for a scenario in which LSB galaxies give rise to most of the Ly$\alpha$ absorbers. It is shown that absorption arising in LSB galaxies is often likely to be attributed to high surface brightness galaxies at larger impact parameters from the quasar line of sight.
Criterion for extensional necking instability in polymeric fluids
Suzanne M. Fielding
Physics , 2011, DOI: 10.1103/PhysRevLett.107.258301
Abstract: We study the linear instability with respect to necking of a filament of polymeric fluid undergoing uniaxial extension. Contrary to the widely discussed Considere criterion, we find the onset of instability to relate closely to the onset of downward curvature in the time (and so strain) evolution of the zz component of the molecular strain, for extension along the z axis. In establishing this result numerically across five of the most widely used models of polymer rheology, and by analytical calculation, we argue it to apply generically. Particularly emphasized is the importance of polymer chain stretching in partially mitigating necking. We comment finally on the relationship between necking and the shape of the underlying steady state constitutive curve for homogeneous extension.
Page 1 /402316
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.