12,493 research outputs found
Human immunodeficiency virus treatment-induced adipose tissue pathology and lipoatrophy: Prevalence and metabolic consequences
Lipoatrophy and metabolic complications of treatment of human immunodeficiency virus (HIV) infection may share common associations with adipose tissue pathology and inflammation. To investigate these relationships, we undertook a large-scale study of adipose tissue, body composition, and metabolic outcomes among HIV-infected adult men at a tertiary hospital HIV cohort during the period 2001-2007. Methods. Assessments included adipose biopsies (np211) for investigation of adipocyte mitochondrial DNA content, adipocytokine expression, and adipose macrophage content; and whole-body dual-energy X-ray absorptiometry (DEXA) scans (np225) for objective body composition changes; 138 individuals contributed both biopsy and DEXA data. Results. Compared with 78 treatment-naive control subjects, 98 zidovudine recipients (48%) and 49 stavudine recipients (67%) had leg fat measures <10% threshold value. Adipose samples associated with current stavudine or zidovudine (np99) revealed significant adipocyte mitochondrial DNA depletion, adipose tissue macrophage infiltration, and elevated proinflammatory cytokine levels, compared with samples from control subjects and nonthymidine nucleoside reverse-transcriptase inhibitor (NRTI) recipients (all P<.05). Improvements in adipose pathology after NRTI switching (np21 longitudinal samples) correlated with increased preswitch adipose inflammation and less severe fat loss (both P<.05). Elevated ratios of total to high-density lipoprotein cholesterol levels and Homeostatic Metabolic Assessment scores correlated independently with lipoatrophy severity (P<.05) and increased body mass index (P<.05) in thymidine NRTI-experienced individuals. No effect of demographic or HIV-related variables, or HIV protease inhibitor therapy exposure was detected. Conclusions. Adipose tissue pathology and lipoatrophic fat loss are highly prevalent among recipients of stavudine- or zidovudine-based HIV treatment and are associated with adverse metabolic outcomes. Restoring adipose tissue health appears to be an important issue in the long-term treatment of this patient population
OMEGA navigation system status and future plans
OMEGA is described as a very low frequency (VLF) radio navigational system operating in the internationally allocated navigation band in the electromagentic spectrum between 10 and 14 kilohertz. Full system implementation with worldwide coverage from eight transmitting stations is planned for the latter 1970's. Experimental stations have operated since 1966 in support of system evaluation and test. These stations provided coverage over most of the North Atlantic, North American Continent, and eastern portions of the North Pacific. This coverage provided the fundamental basis for further development of the system and has been essential to the demonstrated feasibility of the one to two nautical mile root-mean-square system accuracy. OMEGA is available to users in all nations, both on ships and in aircraft
A point mass in an isotropic universe: III. The region
McVittie's solution of Einstein's field equations, representing a point mass
embedded into an isotropic universe, possesses a scalar curvature singularity
at proper radius . The singularity is space-like and precedes, in the
expanding case, all other events in the space-time. It is shown here that this
singularity is gravitationally weak, and the possible structure of the region
is investigated. A characterization of this solution which does not
involve asymptotics is given.Comment: Revtex, 11pp. To appear in Class.Quant.Grav. Paper II appeared as
Class. Quant. Grav. 16 (1999) 122
Enterprise Liability and the Common Law
This book is a timely account of the relationship between the theory of ‘enterprise liability’ and a number of common law doctrines, principally vicarious liability. The account is timely because the dust has now begun to settle on the 1999 decision in Bazley v Curry, where the Supreme Court of Canada reformulated the law relating to the course of employment by seeking to put it on an ‘enterprise liability’ footing, a decision which in turn influenced the House of Lords’ approach to the same issue in Lister v Hesley Hall Ltd. According to the book’s author, Douglas Brodie, the invocation of enterprise liability can be seen as the common law’s response to contemporary concerns over the proper extent of corporate social responsibility, a claim he seeks to substantiate by a wide-ranging analysis of the inter-relationship between enterprise liability and the common law which is not limited to UK law but also makes extensive reference to authorities from Australia, Canada and the USA
Distributed Queries for Quality Control Checks in Clinical Trials
Operational Quality Control (QC) checks are standard practice in clinical trials and ensure ongoing compliance with the study protocol, standard operating procedures (SOPs) and Good Clinical Practice (GCP). We present a method for defining QC checks as distributed queries over case report forms (CRF) and clinical imaging data- sources. Our distributed query system can integrate time-sensitive information in order to populate QC checks that can facilitate discrepancy resolution workflow in clinical trials
Compression of Martian atmosphere for production of oxygen
The compression of CO2 from the Martian atmosphere for production of O2 via an electrochemical cell is addressed. Design specifications call for an oxygen production rate of 10 kg per day and for compression of 50 times that mass of CO2. Those specifications require a compression rate of over 770 cfm at standard Martian temperature and pressure (SMTP). Much of the CO2 being compressed represents waste, unless it can be recycled. Recycling can reduce the volume of gas that must be compressed to 40 cfm at SMTP. That volume reduction represents significant mass savings in the compressor, heating equipment, filters, and energy source. Successful recycle of the gas requires separation of CO (produced in the electrochemical cell) from CO2, N2, and Ar found in the Martian atmosphere. That aspect was the focus of this work
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