46,021 research outputs found
Equal Treatment and the Reproduction of Inequality
A way of seeing is also a way of not seeing
Equal Treatment and the Reproduction of Inequality
A way of seeing is also a way of not seeing
The Cytoscan (TM) model E-II, a new reflectance microscope for intravital microscopy: Comparison with the standard fluorescence method
The Cytoscan(TM) Model E-II (Cytometrics Inc., Philadelphia, Pa., USA) is a newly developed instrument which functions as an intravital microscope and is small and easily portable. Through the use of orthogonal polarization spectral (OPS) imaging, the Cytoscan Model E-II delivers images of the microcirculation which are comparable to those achieved with intravital fluorescence videomicroscopy (IFM), but without the use of fluorescent dyes. The purpose of this study was to validate the Cytoscan Model E-II instrument against IFM. The experiments were carried out on striated muscle in the dorsal skinfold chamber of the awake Syrian hamster. The following parameters were measured in identical regions of interest in the same animal under baseline conditions and 0.5 and 2 h after a 4-hour period of pressure-induced ischemia: arteriolar diameter, venular diameter and venular red blood cell velocity. Bland-Altman plots showed good agreement between the two techniques for venular red blood cell velocity. As expected, arteriolar and venular diameters as measured by the Cytoscan were on average 5 mum smaller than the values from IFM, since the Cytoscan measures the red blood cell column width and IFM measures luminal diameter. Thus, OPS imaging can be used to make valid measurements of microvascular diameter and red blood cell velocity in tissues. Copyright (C) 2000 S. Karger AG, Basel
Growth rates of the population in a branching Brownian motion with an inhomogeneous breeding potential
We consider a branching particle system where each particle moves as an
independent Brownian motion and breeds at a rate proportional to its distance
from the origin raised to the power , for . The asymptotic
behaviour of the right-most particle for this system is already known; in this
article we give large deviations probabilities for particles following
"difficult" paths, growth rates along "easy" paths, the total population growth
rate, and we derive the optimal paths which particles must follow to achieve
this growth rate.Comment: 56 pages, 1 figur
The rigid shell component for superrotation in planetary atmospheres: Angular momentum budget, mechanical analog and simulation of the spin up process
An analysis of superrotation in the atmosphere of planets, with rotation axis perpendicular to the orbital plane is presented. As the atmosphere expands, Hadley cells develop producing a redistribution of mass and angular momentum. A three dimensional thermally driven zonally symmetric spectral model and Laplace transformation simulate the time evolution of a fluid leading from corotation under globally uniform heating to superrotation under globally nonuniform heating. For high viscosities the rigid shell component of atmospheric superrotation can be understood in analogy with a pirouette. During spin up angular momentum is transferred to the planet. For low iscosities, the process is reversed. A tendency toward geostrophy, combined with increase of surface pressure toward the poles (due to meridional mass transport), induces the atmosphere to subrotate temporarily at lower altitudes. Resultant viscous shear near the surface permits angular momentum to flow from the planet into the atmosphere propagating upwards to produce high altitude superrotation rates
On empirical models of the upper atmosphere in the polar regions
Modified expression for exospheric temperature in Jacchia static diffusion models of upper atmosphere in polar region
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