1,446 research outputs found
The Sarbanes-Oxley Act: A Cost-Benefit Analysis Using The U.S. Banking Industry
There are many analyses of the economic effects that regulations, in general, and Sarbanes-Oxley Act, in particular, have had on American business. This analysis looks at the effect that the Sarbanes-Oxley Act has had on the American banking industry. The return on assets and return on equity were obtained from the Federal Reserve Bank for all SEC-registered and nonregistered banks for the period 2000 through 2005. Comparative results indicate that during the period that the Act had been in effect there is a marked negative divergence for SEC-registered banks as opposed to those banks that do not report to the SEC
Nitric oxide regulates skeletal muscle fatigue, fiber type, microtubule organization, and mitochondrial ATP synthesis efficiency through cGMP-dependent mechanisms
Aim: Skeletal muscle nitric oxide–cyclic guanosine monophosphate (NO-cGMP) pathways are impaired in Duchenne and Becker muscular dystrophy partly because of reduced nNOSμ and soluble guanylate cyclase (GC) activity. However, GC function and the consequences of reduced GC activity in skeletal muscle are unknown. In this study, we explore the functions of GC and NO-cGMP signaling in skeletal muscle.
Results: GC1, but not GC2, expression was higher in oxidative than glycolytic muscles. GC1 was found in a complex with nNOSμ and targeted to nNOS compartments at the Golgi complex and neuromuscular junction. Baseline GC activity and GC agonist responsiveness was reduced in the absence of nNOS. Structural analyses revealed aberrant microtubule directionality in GC1−/− muscle. Functional analyses of GC1−/− muscles revealed reduced fatigue resistance and postexercise force recovery that were not due to shifts in type IIA–IIX fiber balance. Force deficits in GC1−/− muscles were also not driven by defects in resting mitochondrial adenosine triphosphate (ATP) synthesis. However, increasing muscle cGMP with sildenafil decreased ATP synthesis efficiency and capacity, without impacting mitochondrial content or ultrastructure.
Innovation: GC may represent a new target for alleviating muscle fatigue and that NO-cGMP signaling may play important roles in muscle structure, contractility, and bioenergetics.
Conclusions: These findings suggest that GC activity is nNOS dependent and that muscle-specific control of GC expression and differential GC targeting may facilitate NO-cGMP signaling diversity. They suggest that nNOS regulates muscle fiber type, microtubule organization, fatigability, and postexercise force recovery partly through GC1 and suggest that NO-cGMP pathways may modulate mitochondrial ATP synthesis efficiency
Curvature-Induced Defect Unbinding in Toroidal Geometries
Toroidal templates such as vesicles with hexatic bond orientational order are
discussed. The total energy including disclination charges is explicitly
computed for hexatic order embedded in a toroidal geometry. Related results
apply for tilt or nematic order on the torus in the one Frank constant
approximation. Although there is no topological necessity for defects in the
ground state, we find that excess disclination defects are nevertheless
energetically favored for fat torii or moderate vesicle sizes. Some
experimental consequences are discussed.Comment: 12 pages, 15 eps figure
The ACS Survey of Galactic Globular Clusters: M54 and Young Populations in the Sagittarius Dwarf Spheroidal Galaxy
We present new Hubble Space Telescope photometry of the massive globular
cluster M54 (NGC 6715) and the superposed core of the tidally disrupted
Sagittarius (Sgr) dSph galaxy as part of the ACS Survey of Galactic Globular
Clusters. Our deep (F606W~26.5), high-precision photometry yields an
unprecedentedly detailed color-magnitude diagram showing the extended blue
horizontal branch and multiple main sequences of the M54+Sgr system. The
distance and reddening to M54 are revised usingboth isochrone and main-sequence
fitting to (m-M)_0=17.27 and E(B-V)=0.15. Preliminary assessment finds the
M54+Sgr field to be dominated by the old metal-poor populations of Sgr and the
globular cluster. Multiple turnoffs indicate the presence of at least two
intermediate-aged star formation epochs with 4 and 6 Gyr ages and [Fe/H]=-0.4
to -0.6. We also clearly show, for the first time, a prominent, 2.3 Gyr old Sgr
population of near-solar abundance. A trace population of even younger (0.1-0.8
Gyr old), more metal-rich ([Fe/H]\sim0.6) stars is also indicated. The Sgr
age-metallicity relation is consistent with a closed-box model and multiple
(4-5) star formation bursts over the entire life of the satellite, including
the time since Sgr began disrupting.Comment: Accepted to ApJ Letter; 11 pages, 2 figures; figure 1 uploaded as
jpg; paper in ApJ format with full-resolution figures available at:
http://www.astro.ufl.edu/~ata/public_hstgc/paperIV/paperIV.p
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Distribution of SARS-CoV-2 RNA Signal in a Home with COVID-19 Positive Occupants
Although many COVID-19 patients quarantine and recover at home, the dispersal of SARS-CoV-2 onto surfaces and dust within the home environment remains poorly understood. To investigate the distribution and persistence of SARS-CoV-2 in a quarantine home, samples were collected from a household with two confirmed COVID-19 cases (one adult and one child). Home surface swab and dust samples were collected two months after symptom onset (and one month after symptom resolution) in the household. The strength of the SARS-CoV-2 molecular signal in fomites varied as a function of sample location, surface material and cleaning practices. Notably, the SARS-CoV-2 RNA signal was detected at several locations throughout the household although cleaning appears to have attenuated the signal on many surfaces. Of the 24 surfaces sampled, 46% were SARS-CoV-2 positive at the time of sampling. The SARS-CoV-2 concentrations in dust recovered from floor and HVAC filter samples ranged from 104-105 N2 gene copies/g dust. While detection of viral RNA does not imply infectivity, this study confirms that the SARS-CoV-2 RNA signal can be detected at several locations within a COVID-19 quarantine home and can persist after symptoms have resolved. In addition, the concentration of SARS-CoV-2 (normalized per unit mass of dust) recovered in home HVAC filters may prove useful for estimating SARS-CoV-2 airborne levels in homes.This work was supported by Whole Communities-Whole Health, a research grand challenge at the University of Texas at Austin. In addition, the work that provided the basis for this publication was also supported by funding under an award TXHHU0046-18 with the U.S. Department of Housing and Urban Development.Office of the VP for Researc
Electron-Phonon Coupling in Highly-Screened Graphene
Photoemission studies of graphene have resulted in a long-standing
controversy concerning the strength of the experimental electron-phonon
interaction in comparison with theoretical calculations. Using high-resolution
angle-resolved photoemission spectroscopy we study graphene grown on a copper
substrate, where the metallic screening of the substrate substantially reduces
the electron-electron interaction, simplifying the comparison of the
electron-phonon interaction between theory and experiment. By taking the
nonlinear bare bandstructure into account, we are able to show that the
strength of the electron-phonon interaction does indeed agree with theoretical
calculations. In addition, we observe a significant bandgap at the Dirac point
of graphene.Comment: Submitted to Phys. Rev. Lett. on July 20, 201
The Ursinus Weekly, May 29, 1969
S.F.A.R.C. blocked on rules proposals • William F. Buckley featured at June 9th Commencement for 304 graduating seniors • 316 freshmen admitted for Fall \u2769 semester • New Vice-Presidents: Pettit, Richter named • IF wrap-up • New members of Sigma Xi Club; 11 students, 4 faculty selected • Editorials: Proper emphasis; Goodbye, and all that • Focus: T.W. Rhody • It\u27s all over • Polemic finale • One-acts reviewed • A story • Eulogy to Dr. Courtney Smith and the one dead in the ghetto • Velikovsky: The outcast • Board meeting • Outing Club ends diversified year • Tacconelli, Maurer finish with highest batting marks • UC netmen hammer way to best log since \u2756 • Final examination schedulehttps://digitalcommons.ursinus.edu/weekly/1176/thumbnail.jp
Reduced Coupling of Oxidative Phosphorylation In Vivo Precedes Electron Transport Chain Defects Due to Mild Oxidative Stress in Mice
Oxidative stress and mitochondrial function are at the core of many degenerative conditions. However, the interaction between oxidative stress and in vivo mitochondrial function is unclear. We used both pharmacological (2 week paraquat (PQ) treatment of wild type mice) and transgenic (mice lacking Cu, Zn-superoxide dismutase (SOD1−/−)) models to test the effect of oxidative stress on in vivo mitochondrial function in skeletal muscle. Magnetic resonance and optical spectroscopy were used to measure mitochondrial ATP and oxygen fluxes and cell energetic state. In both models of oxidative stress, coupling of oxidative phosphorylation was significantly lower (lower P/O) at rest in vivo in skeletal muscle and was dose-dependent in the PQ model. Despite this reduction in efficiency, in vivo mitochondrial phosphorylation capacity (ATPmax) was maintained in both models, and ex vivo mitochondrial respiration in permeabilized muscle fibers was unchanged following PQ treatment. In association with the reduced P/O, PQ treatment led to a dose-dependent reduction in PCr/ATP ratio and increased phosphorylation of AMPK. These results indicate that oxidative stress uncouples oxidative phosphorylation in vivo and results in energetic stress in the absence of defects in the mitochondrial electron transport chain
The local symmetries of M-theory and their formulation in generalised geometry
In the doubled field theory approach to string theory, the T-duality group is
promoted to a manifest symmetry at the expense of replacing ordinary Riemannian
geometry with generalised geometry on a doubled space. The local symmetries are
then given by a generalised Lie derivative and its associated algebra. This
paper constructs an analogous structure for M-theory. A crucial by-product of
this is the derivation of the physical section condition for M-theory
formulated in an extended space.Comment: 20 pages, v2: Author Name corrected, v3: typos correcte
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