3,340 research outputs found
Role of arginase 2 in systemic metabolic activity and adipose tissue fatty acid metabolism in diet-induced obese mice
Visceral adipose tissue (VAT) inflammation and metabolic dysregulation are key components of obesity-induced metabolic disease. Upregulated arginase, a ureahydrolase enzyme with two isoforms (A1-cytosolic and A2-mitochondrial), is implicated in pathologies associated with obesity and diabetes. This study examined A2 involvement in obesity-associated metabolic and vascular disorders. WT and globally deleted A2(−/−) or A1(+/−) mice were fed either a high fat/high sucrose (HFHS) diet or normal diet (ND) for 16 weeks. Increases in body and VAT weight of HFHS-fed WT mice were abrogated in A2−/−, but not A1+/−, mice. Additionally, A2−/− HFHS-fed mice exhibited higher energy expenditure, lower blood glucose, and insulin levels compared to WT HFHS mice. VAT and adipocytes from WT HFHS fed mice showed greater A2 expression and adipocyte size and reduced expression of PGC-1α, PPAR-γ, and adiponectin. A2 deletion blunted these effects, increased levels of active AMPK-α, and upregulated genes involved in fatty acid metabolism. A2 deletion prevented HFHS-induced VAT collagen deposition and inflammation, which are involved in adipocyte metabolic dysfunction. Endothelium-dependent vasorelaxation, impaired by HFHS diet, was significantly preserved in A2−/− mice, but more prominently maintained in A1+/− mice. In summary, A2 is critically involved in HFHS-induced VAT inflammation and metabolic dysfunction
“REFORM” OF THE UNITED STATES AND BRAZILIAN RETIREMENT SYSTEMS FOR FEDERAL EMPLOYEES
Recently, Brazil made changes to its retirement system as it concerned public sector workers, changes which in certain ways were similar to those which occurred for most federal workers in the United States somewhat over a quarter of a century ago. Broadly speaking it involved the conversion of a purely pay-as-you-go defined benefit plans to a hybrid of a reduced pay-as-you-go defined benefit plan with a funded defined contribution plan. In theUnited States, the latter is called the Thrift Savings Plan which now has over 4.5 million participants and nearly $400 billion in assets.This paper offers a brief history of the origins of the U.S. system up until the changes in question were made, what were among the major factors or considerations which appear to have spurred the changes, a little bit about the constituencies which seem to have driven or resisted change as the case may be, the modifications that were envisioned, and expectations as to the difference that was expected to be wrought from those alterations. It canvases the differences between the then “old” and the “new” systems in relation to what was ostensibly sought to be achieved. It then draws on what is a surprisingly thin literature to describe the outcomes of the changes more than 25 years later with an eye to hoped-for or anticipated results at the outset. We then detail important elements of the new Brazilian system – which is at an early stage – with an eye to similarities and differences between it and the one we have described with a focus on how the outcomes of the system in theU.S.might bear on thinking inBrazilas it moves forward with its own. We conclude briefly with thoughts on the nature and merits of further pursuing the comparison and inquiry
Interventional cardiology : Cost-effectiveness of PCI guided by fractional flow reserve
Coronary revascularization strategies have been evaluated in numerous clinical trials. As coronary revascularization has become more common, concerns over financial costs have increased
Evidence for bacteriophage T7 tail extension during DNA injection
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
CGRaBS: An All-Sky Survey of Gamma-Ray Blazar Candidates
We describe a uniform all-sky survey of bright blazars, selected primarily by
their flat radio spectra, that is designed to provide a large catalog of likely
gamma-ray AGN. The defined sample has 1625 targets with radio and X-ray
properties similar to those of the EGRET blazars, spread uniformly across the
|b| > 10 deg sky. We also report progress toward optical characterization of
the sample; of objects with known R < 23, 85% have been classified and 81% have
measured redshifts. One goal of this program is to focus attention on the most
interesting (e.g., high redshift, high luminosity, ...) sources for intensive
multiwavelength study during the observations by the Large Area Telescope (LAT)
on GLAST.Comment: 18 pages, 6 figures, 1 machine-readable table available at
http://astro.stanford.edu/CGRaBS/ ; accepted for publication in ApJ
Quiescent H2 Emission From Pre-Main Sequence Stars in Chamaeleon I
We report the discovery of quiescent emission from molecular hydrogen gas
located in the circumstellar disks of six pre-main sequence stars, including
two weak-line T Tauri stars (TTS), and one Herbig AeBe star, in the Chamaeleon
I star forming region. For two of these stars, we also place upper limits on
the 2->1 S(1)/1->0 S(1) line ratios of 0.4 and 0.5. Of the 11 pre-main sequence
sources now known to be sources of quiescent near-infrared hydrogen emission,
four possess transitional disks, which suggests that detectable levels of H
emission and the presence of inner disk holes are correlated. These H
detections demonstrate that these inner holes are not completely devoid of gas,
in agreement with the presence of observable accretion signatures for all four
of these stars and the recent detections of [Ne II] emission from three of
them. The overlap in [Ne II] and H detections hints at a possible
correlation between these two features and suggests a shared excitation
mechanism of high energy photons. Our models, combined with the kinematic
information from the H lines, locate the bulk of the emitting gas at a few
tens of AU from the stars. We also find a correlation between H detections
and those targets which possess the largest H equivalent widths,
suggesting a link between accretion activity and quiescent H emission. We
conclude that quiescent H emission from relatively hot gas within the disks
of TTS is most likely related to on-going accretion activity, the production of
UV photons and/or X-rays, and the evolutionary status of the dust grain
populations in the inner disks.Comment: 12 pages, emulateapj, Accepted by Ap
Surveillance of a Faster Fixed-Course Target
The maximum surveillance of a target which is holding course is considered,
wherein an observer vehicle aims to maximize the time that a faster target
remains within a fixed-range of the observer. This entails two coupled phases:
an approach phase and observation phase. In the approach phase, the observer
strives to make contact with the faster target, such that in the observation
phase, the observer is able to maximize the time where the target remains
within range. Using Pontryagin's Minimum Principle, the optimal control laws
for the observer are found in closed-form. Example scenarios highlight various
aspects of the engagement.Comment: 12 pages, 8 figure
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