14 research outputs found
Benjamini-Schramm Convergence of Normalized Characteristic Numbers of Riemannian Manifolds
We study a weak form of Gromov-Hausdorff convergence
of Riemannian manifolds, also known as
Benjamini-Schramm convergence. This concept
is also applicable to other areas and has widely
been studied in the context of graphs.
The main result is the continuity of characteristic
numbers normalized by the volume with respect
to the Benjamini-Schramm topology on the class
of Riemannian manifolds with a uniform lower
bound on injectivity radius and Ricci curvature.
An immediate consequence is a comparison theorem
that gives for any characteristic number a
linear bound in terms of the volume on the entire
class of manifolds mentioned. We give another
interpretation of the result showing that characteristic
numbers can be reconstructed with some
accuracy from local random information
Plasma Dynamics
Contains reports on ten research projects divided into two sections.National Science Foundation (Grant ENG79-07047)U.S. Air Force - Office of Scientific Research (Grant AFOSR-77-3143)U.S. Department of Energy (Contract DE-ACO2-78ET51013)U.S. Department of Energy (Contract DE-ASO2-78ET53073.AO02)U.S. Department of Energy (Contract ET-78-S-02-4682)U.S. Department of Energy (Contract DE-AS02-78ET53074)U.S. Department of Energy (Contract DE-ASO2-78ET53050)U.S. Department of Energy (Contract DE-AS02-78ET51002)U.S. Department of Energy (Contract DE-ASO2-78ET53076
Plasma Dynamics
Contains table of contents for Section 2 and reports on four research projects.Lawrence Livermore National Laboratory (Subcontract 6264005)National Science Foundation (Grant ECS 84-13173)National Science Foundation (Grant ECS 85-14517)U.S. Air Force - Office of Scientifc Research (Contract AFOSR 84-0026)U.S. Army - Harry Diamond Laboratories (Contract DAAL02-86-C-0050)U.S. Navy - Office of Naval Research (Contract N00014-87-K-2001)U.S. Department of Energy (Contract DE-AC02-78-ET-51013)National Science Foundation (Grant ECS 85-1 5032
Plasma Dynamics
Contains table of contents for Section 2 and reports on four research projects.Lawrence Livermore National Laboratory Subcontract 6264005National Science Foundation Grant ECS 84-13173National Science Foundation Grant ECS 85-14517U.S. Air Force - Office of Scientific Research Contract AFOSR 84-0026U.S. Army - Harry Diamond Laboratories Contract DAAL02-86-C-0050U.S. Navy - Office of Naval Research Contract N00014-87-K-2001National Science Foundation Grant ECS 85-15032National Science Foundation Grant ECS 88-22475U.S. Department of Energy Contract DE-AC02-ET-5101
Human placental oxygenation in late gestation: experimental and theoretical approaches
The placenta is crucial for life. It is an ephemeral but complex organ acting as the barrier interface between maternal and fetal circulations, providing exchange of gases, nutrients, hormones, waste products and immunoglobulins. Many gaps exist in our understanding of the detailed placental structure and function, particularly in relation to oxygen handling and transfer in healthy and pathological states in utero. Measurements to understand oxygen transfer in vivo in the human are limited, with no general agreement on the most appropriate methods. An invasive method for measuring partial pressure of oxygen in the intervillous space through needle electrode insertion at the time of Caesarean sections has been reported. This allows for direct measurements in vivo whilst maintaining near normal placental conditions; however, there are practical and ethical implications in using this method for determination of placental oxygenation. Furthermore, oxygen levels are likely to be highly heterogeneous within the placenta. Emerging non-invasive techniques, such as MRI, and ex vivo research are capable of enhancing and improving current imaging methodology for placental villous structure and increase the precision of oxygen measurement within placental compartments. These techniques, in combination with mathematical modelling, have stimulated novel cross-disciplinary approaches that could advance our understanding of placental oxygenation and its metabolism in normal and pathological pregnancies, improving clinical treatment options and ultimately outcomes for the patient
Decrements of body mass index are associated with poor outcomes of idiopathic pulmonary fibrosis patients.
BackgroundThe processes that result in progression of idiopathic pulmonary fibrosis (IPF) remain enigmatic. Moreover, the course of this disease can be highly variable and difficult to accurately predict. We hypothesized analyses of body mass index (BMI), a simple, routine clinical measure, may also have prognostic value in these patients, and might provide mechanistic insights. We investigated the associations of BMI changes with outcome, plasma adipokines, and adaptive immune activation among IPF patients.MethodsData were analyzed in an IPF discovery cohort (n = 131) from the University of Pittsburgh, and findings confirmed in patients from the University of Alabama at Birmingham (n = 148). Plasma adipokines were measured by ELISA and T-cell phenotypes determined by flow cytometry.ResultsTransplant-free one-year survivals in subjects with the greatest rates of BMI decrements, as percentages of initial BMI (>0.68%/month), were worse than among those with more stable BMI in both discovery (HR = 1.8, 95%CI = 1.1-3.2, p = 0.038) and replication cohorts (HR = 2.5, 95%CI = 1.2-5.2, p = 0.02), when adjusted for age, baseline BMI, and pulmonary function. BMI decrements >0.68%/month were also associated with greater mortality after later lung transplantations (HR = 4.6, 95%CI = 1.7-12.5, p = 0.003). Circulating leptin and adiponectin levels correlated with BMI, but neither adipokine was prognostic per se. BMI decrements were significantly associated with increased proportions of circulating end-differentiated (CD28null) CD4 T-cells (CD28%), a validated marker of repetitive T-cell activation and IPF prognoses.ConclusionsIPF patients with greatest BMI decrements had worse outcomes, and this effect persisted after lung transplantation. Weight loss in these patients is a harbinger of poor prognoses, and may reflect an underlying systemic process, such as adaptive immune activation