4,561 research outputs found
Strengthening the policy setting process for global malaria control and elimination
The scale-up of malaria control efforts in recent years, coupled with major investments in malaria research, has produced impressive public health impact in a number of countries and has led to the development of new tools and strategies aimed at further consolidating malaria control goals. As a result, there is a growing need for the malaria policy setting process to rapidly review increasing amounts of evidence
Site-Specific Effects of PECAM-1 on Atherosclerosis in LDL Receptor-Deficient Mice
Objective—Atherosclerosis is a vascular disease that involves lesion formation at sites of disturbed flow under the influence of genetic and environmental factors. Endothelial expression of adhesion molecules that enable infiltration of immune cells is important for lesion development. Platelet/endothelial cell adhesion molecule-1 (PECAM-1; CD31) is an adhesion and signaling receptor expressed by many cells involved in atherosclerotic lesion development. PECAM-1 transduces signals required for proinflammatory adhesion molecule expression at atherosusceptible sites; thus, it is predicted to be proatherosclerotic. PECAM-1 also inhibits inflammatory responses, on which basis it is predicted to be atheroprotective.
Methods and Results—We evaluated herein the effect of PECAM-1 deficiency on development of atherosclerosis in LDL receptor– deficient mice. We found that PECAM-1 has both proatherosclerotic and atheroprotective effects, but that the former dominate in the inner curvature of the aortic arch whereas the latter dominate in the aortic sinus, branching arteries, and descending aorta. Endothelial cell expression of PECAM-1 was sufficient for its atheroprotective effects in the aortic sinus but not in the descending aorta, where the atheroprotective effects of PECAM-1 also required its expression on bone marrow–derived cells.
Conclusion—We conclude that PECAM-1 influences initiation and progression of atherosclerosis both positively and negatively, and that it does so in a site-specific manner. (Arterioscler Thromb Vasc Biol. 2008;28:1996-2002
Space-time thermodynamics and subsystem observables in a kinetically constrained model of glassy systems
In a recent article [M. Merolle et al., Proc. Natl. Acad. Sci. USA 102, 10837
(2005)] it was argued that dynamic heterogeneity in -dimensional glass
formers is a manifestation of an order-disorder phenomenon in the
dimensions of spacetime. By considering a dynamical analogue of the free
energy, evidence was found for phase coexistence between active and inactive
regions of spacetime, and it was suggested that this phenomenon underlies the
glass transition. Here we develop these ideas further by investigating in
detail the one-dimensional Fredrickson-Andersen (FA) model in which the active
and inactive phases originate in the reducibility of the dynamics. We
illustrate the phase coexistence by considering the distributions of mesoscopic
spacetime observables. We show how the analogy with phase coexistence can be
strengthened by breaking microscopic reversibility in the FA model, leading to
a non-equilibrium theory in the directed percolation universality class.Comment: 12 pages, 11 figures, final version with minor change
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