86 research outputs found
Semi-empirical catalog of early-type galaxy-halo systems: dark matter density profiles, halo contraction and dark matter annihilation strength
With SDSS galaxy data and halo data from up-to-date N-body simulations we
construct a semi-empirical catalog (SEC) of early-type systems by making a
self-consistent bivariate statistical match of stellar mass (M_star) and
velocity dispersion (sigma) with halo virial mass (M_vir). We then assign
stellar mass profile and velocity dispersion profile parameters to each system
in the SEC using their observed correlations with M_star and sigma.
Simultaneously, we solve for dark matter density profile of each halo using the
spherical Jeans equation. The resulting dark matter density profiles deviate in
general from the dissipationless profile of NFW or Einasto and their mean inner
density slope and concentration vary systematically with M_vir. Statistical
tests of the distribution of profiles at fixed M_vir rule out the null
hypothesis that it follows the distribution predicted by N-body simulations for
M_vir ~< 10^{13.5-14.5} M_solar. These dark matter profiles imply that dark
matter density is, on average, enhanced significantly in the inner region of
halos with M_vir ~< 10^{13.5-14.5} M_solar supporting halo contraction. The
main characteristics of halo contraction are: (1) the mean dark matter density
within the effective radius has increased by a factor varying systematically up
to ~ 3-4 at M_vir = 10^{12} M_solar, and (2) the inner density slope has a mean
of ~ 1.3 with rho(r) ~ r^{-alpha} and a halo-to-halo rms scatter of
rms(alpha) ~ 0.4-0.5 for 10^{12} M_solar ~< M_vir ~< 10^{13-14} M_solar steeper
than the NFW profile (alpha=1). Based on our results we predict that halos of
nearby elliptical and lenticular galaxies can, in principle, be promising
targets for gamma-ray emission from dark matter annihilation.Comment: 43 pages, 20 figures, JCAP, revised and accepted versio
Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion
We examine the cosmological constraining power of future large-scale weak
lensing surveys on the model of \emph{Euclid}, with particular reference to
primordial non-Gaussianity. Our analysis considers several different estimators
of the projected matter power spectrum, based on both shear and flexion, for
which we review the covariances and Fisher matrices. The bounds provided by
cosmic shear alone for the local bispectrum shape, marginalized over
, are at the level of . We consider
three additional bispectrum shapes, for which the cosmic shear constraints
range from (equilateral shape) up to (orthogonal shape). The competitiveness of cosmic
flexion constraints against cosmic shear ones depends on the galaxy intrinsic
flexion noise, that is still virtually unconstrained. Adopting the very high
value that has been occasionally used in the literature results in the flexion
contribution being basically negligible with respect to the shear one, and for
realistic configurations the former does not improve significantly the
constraining power of the latter. Since the flexion noise decreases with
decreasing scale, by extending the analysis up to
cosmic flexion, while being still subdominant, improves the shear constraints
by when added. However on such small scales the highly non-linear
clustering of matter and the impact of baryonic physics make any error
estimation uncertain. By considering lower, and possibly more realistic, values
of the flexion intrinsic shape noise results in flexion constraining power
being a factor of better than that of shear, and the bounds on
and being improved by a factor of upon
their combination. (abridged)Comment: 30 pages, 4 figures, 4 tables. To appear on JCA
Exploring new uses of video with videoSpace
Abstract. This paper describes videoSpace, a software toolkit designed to facilitate the integration of image streams into existing or new documents and applications to support new forms of human-computer interaction and collaborative activities. In this perspective, videoSpace is not focused on performance or reliability issues, but rather on the ability to support rapid prototyping and incremental development of video applications. The toolkit is described in extensive details, by showing the architecture and functionalities of its class library and basic tools. Several projects developed with videoSpace are also presented, illustrating its potential and the new uses of video it will allow in the future.
Anti-D monoclonal antibodies from 23 human and rodent cell lines display diverse IgG Fc-glycosylation profiles that determine their clinical efficacy
Anti-D immunoglobulin (Anti-D Ig) prophylaxis prevents haemolytic disease of the fetus and newborn. Monoclonal IgG anti-Ds (mAb-Ds) would enable unlimited supplies but have differed in efficacy in Fc gamma RIIIa-mediated ADCC assays and clinical trials. Structural variations of the oligosaccharide chains of mAb-Ds are hypothesised to be responsible. Quantitative data on 12 Fc-glycosylation features of 23 mAb-Ds (12 clones, 5 produced from multiple cell lines) and one blood donor-derived anti-D Ig were obtained by HPLC and mass spectrometry using 3 methods. Glycosylation of mAb-Ds from human B-lymphoblastoid cell lines (B) was similar to anti-D Ig although fucosylation varied, affecting ADCC activity. In vivo, two B mAb-Ds with 77-81% fucosylation cleared red cells and prevented D-immunisation but less effectively than anti-D Ig. High fucosylation (>89%) of mouse-human heterohybridoma (HH) and Chinese hamster ovary (CHO) mAb-Ds blocked ADCC and clearance. Rat YB2/0 mAb-Ds with 60%) together with lower fucosylation (<60%) as safe features of mAb-Ds for mediating rapid red cell clearance at low doses, to enable effective, inexpensive prophylaxis.Proteomic
IgG N-glycans as potential biomarkers for determining galactose tolerance in Classical Galactosaemia
N-glycan processing and assembly defects have been demonstrated in untreated and partially treated patients with Classical Galactosaemia. These defects may contribute to the ongoing pathophysiology of this disease. The aim of this study was to develop an informative method of studying differential galactose tolerance levels and diet control in individuals with Galactosaemia, compared to the standard biochemical markers. Ten Galactosaemia adults with normal intellectual outcomes were analyzed in the study. Five subjects followed galactose liberalization, increments of 300. mg to 4000. mg/day over 16. weeks, and were compared to five adult Galactosaemia controls on a galactose restricted diet. All study subjects underwent clinical and biochemical monitoring of red blood cell galactose-1-phosphate (RBC Gal-1-P) and urinary galactitol levels. Serum N-glycans were isolated and analyzed by normal phase high-performance liquid chromatography (NP-HPLC) with galactosylation of IgG used as a specific biomarker of galactose tolerance. IgG N-glycan profiles showed consistent individual alterations in response to diet liberalization. The individual profiles were improved for all, but one study subject, at a galactose intake of 1000. mg/day, with decreases in agalactosylated (G0) and increases in digalactosylated (G2) N-glycans. We conclude that IgG N-glycan profiling is an improved method of monitoring variable galactosylation and determining individual galactose tolerance in Galactosaemia compared to the standard methods
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