404 research outputs found
The Paradox of Muscle Hypertrophy in Muscular Dystrophy
Mutations in the dystrophin gene cause Duchenne and Becker muscular dystrophy in humans and syndromes in mice, dogs, and cats. Affected humans and dogs have progressive disease that leads primarily to muscle atrophy. Mdx mice progress through an initial phase of muscle hypertrophy followed by atrophy. Cats have persistent muscle hypertrophy. Hypertrophy in humans has been attributed to deposition of fat and connective tissue (pseudohypertrophy). Increased muscle mass (true hypertrophy) has been documented in animal models. Muscle hypertrophy can exaggerate postural instability and joint contractures. Deleterious consequences of muscle hypertrophy should be considered when developing treatments for muscular dystrophy
Recent developments in planet migration theory
Planetary migration is the process by which a forming planet undergoes a
drift of its semi-major axis caused by the tidal interaction with its parent
protoplanetary disc. One of the key quantities to assess the migration of
embedded planets is the tidal torque between the disc and planet, which has two
components: the Lindblad torque and the corotation torque. We review the latest
results on both torque components for planets on circular orbits, with a
special emphasis on the various processes that give rise to additional, large
components of the corotation torque, and those contributing to the saturation
of this torque. These additional components of the corotation torque could help
address the shortcomings that have recently been exposed by models of planet
population syntheses. We also review recent results concerning the migration of
giant planets that carve gaps in the disc (type II migration) and the migration
of sub-giant planets that open partial gaps in massive discs (type III
migration).Comment: 52 pages, 18 figures. Review article to be published in "Tidal
effects in Astronomy and Astrophysics", Lecture Notes in Physic
A Helicity-Based Method to Infer the CME Magnetic Field Magnitude in Sun and Geospace: Generalization and Extension to Sun-Like and M-Dwarf Stars and Implications for Exoplanet Habitability
Patsourakos et al. (Astrophys. J. 817, 14, 2016) and Patsourakos and
Georgoulis (Astron. Astrophys. 595, A121, 2016) introduced a method to infer
the axial magnetic field in flux-rope coronal mass ejections (CMEs) in the
solar corona and farther away in the interplanetary medium. The method, based
on the conservation principle of magnetic helicity, uses the relative magnetic
helicity of the solar source region as input estimates, along with the radius
and length of the corresponding CME flux rope. The method was initially applied
to cylindrical force-free flux ropes, with encouraging results. We hereby
extend our framework along two distinct lines. First, we generalize our
formalism to several possible flux-rope configurations (linear and nonlinear
force-free, non-force-free, spheromak, and torus) to investigate the dependence
of the resulting CME axial magnetic field on input parameters and the employed
flux-rope configuration. Second, we generalize our framework to both Sun-like
and active M-dwarf stars hosting superflares. In a qualitative sense, we find
that Earth may not experience severe atmosphere-eroding magnetospheric
compression even for eruptive solar superflares with energies ~ 10^4 times
higher than those of the largest Geostationary Operational Environmental
Satellite (GOES) X-class flares currently observed. In addition, the two
recently discovered exoplanets with the highest Earth-similarity index, Kepler
438b and Proxima b, seem to lie in the prohibitive zone of atmospheric erosion
due to interplanetary CMEs (ICMEs), except when they possess planetary magnetic
fields that are much higher than that of Earth.Comment: http://adsabs.harvard.edu/abs/2017SoPh..292...89
A Nationwide 2010-2012 Analysis of U.S. Health Care Utilization in Inflammatory Bowel Diseases
Cellular mechanisms in basic and clinical gastroenterology and hepatolog
Radio Science Investigation on a Mercury Orbiter Mission
We review the results from {\it Mariner 10} regarding Mercury's gravity field
and the results from radar ranging regarding topography. We discuss the
implications of improving these results, including a determination of the polar
component, as well as the opportunity to perform relativistic gravity tests
with a future {\it Mercury Orbiter}. With a spacecraft placed in orbit with
periherm at 400 km altitude, apherm at 16,800 km, period 13.45 hr and latitude
of periherm at +30 deg, one can expect a significant improvement in our
knowledge of Mercury's gravity field and geophysical properties. The 2000 Plus
mission that evolved during the European Space Agency (ESA) {\it Mercury
Orbiter} assessment study can provide a global gravity field complete through
the 25th degree and order in spherical harmonics. If after completion of the
main mission, the periherm could be lowered to 200 km altitude, the gravity
field could be extended to 50th degree and order. We discuss the possibility
that a search for a Hermean ionosphere could be performed during the mission
phases featuring Earth occultations.
Because of its relatively large eccentricity and close proximity to the Sun,
Mercury's orbital motion provides one of the best solar-system tests of general
relativity. Consequently, we emphasize the number of feasible relativistic
gravity tests that can be performed within the context of the parameterized
post-Newtonian formalism - a useful framework for testing modern gravitational
theories. We pointed out that current results on relativistic precession of
Mercury's perihelion are uncertain by 0.5 %, and we discuss the expected
improvement using {\it Mercury Orbiter}. We discuss the importance of {\it
Mercury Orbiter} for setting limits on a possible time variation in theComment: 23 pages, LaTeX, no figure
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Author Correction: A chickpea genetic variation map based on the sequencing of 3,366 genomes
In Extended Data Fig. 1 of this Article, the labels âMarket classâ and âBiological statusâ were inadvertently swapped. In the corresponding figure legend, âTrack 1: Biological status; Track 2: Market class;â should have been âTrack 1: Market class; Track 2: Biological status;â. The original Article has been corrected online
Accounting for nature: assessing habitats in the UK countryside.
Countryside Survey 2000 (CS2000) and the
Northern Ireland Countryside Survey 2000
(NICS2000) have been designed to provide
detailed information about the habitats and
landscape features that are important elements
of our countryside. They can tell us about the
âstockâ of these resources, that is how much of
them we have and where they are to be found,
and they can give us an insight into their
condition based on the variety and abundance
of the plant species associated with them. Using
information from previous surveys, we can also
gain an understanding of how the stock and
condition of these habitats and landscape
features are changing over time. We can build up
a sort of balance sheet or an account of natural
assets in the UK countryside. In this report we
look in particular at the period between the last
two surveys, 1990 and 1998
Genome-wide association meta-analysis identifies 48 risk variants and highlights the role of the stria vascularis in hearing loss
Hearing loss is one of the top contributors to years lived with disability and is a risk factor for dementia. Molecular evidence on the cellular origins of hearing loss in humans is growing. Here, we performed a genome-wide association meta-analysis of clinically diagnosed and self-reported hearing impairment on 723,266 individuals and identified 48 significant loci, 10 of which are novel. A large proportion of associations comprised missense variants, half of which lie within known familial hearing loss loci. We used single-cell RNA-sequencing data from mouse cochlea and brain and mapped common-variant genomic results to spindle, root, and basal cells from the stria vascularis, a structure in the cochlea necessary for normal hearing. Our findings indicate the importance of the stria vascularis in the mechanism of hearing impairment, providing future paths for developing targets for therapeutic intervention in hearing loss
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