9,404 research outputs found
Case report: early aortic valve degeneration associated with interstitial deletion of chromosome 2-46,XX,del (2)(q31.3; q32.2).
Interstitial deletions within the long arm of chromosome 2, involving the 2q31q33 region, are rare but are known to be associated with delays in development, behavioral problems, facial dysmorphism and various hand/foot anomalies.
Here, we describe a case with an interstitial 2q31.3.q32.2 deletion, presenting the previously described phenotype, exhibiting fibromyxoid degeneration of the aortic valve in addition to previously described clinical features.
Interstitial deletion in chromosome 2q31.2q32.3 might be associated to a fibromyxoid degeneration of valvular leaflets generating regurgitation. Patients diagnosed with this mutation may require investigation to rule out a valvular disease
In-orbit Vignetting Calibrations of XMM-Newton Telescopes
We describe measurements of the mirror vignetting in the XMM-Newton
Observatory made in-orbit, using observations of SNR G21.5-09 and SNR
3C58 with the EPIC imaging cameras. The instrument features that complicate
these measurements are briefly described. We show the spatial and energy
dependences of measured vignetting, outlining assumptions made in deriving the
eventual agreement between simulation and measurement. Alternate methods to
confirm these are described, including an assessment of source elongation with
off-axis angle, the surface brightness distribution of the diffuse X-ray
background, and the consistency of Coma cluster emission at different position
angles. A synthesis of these measurements leads to a change in the XMM
calibration data base, for the optical axis of two of the three telescopes, by
in excess of 1 arcminute. This has a small but measureable effect on the
assumed spectral responses of the cameras for on-axis targets.Comment: Accepted by Experimental Astronomy. 26 pages, 18 figure
Inverse Scattering for Gratings and Wave Guides
We consider the problem of unique identification of dielectric coefficients
for gratings and sound speeds for wave guides from scattering data. We prove
that the "propagating modes" given for all frequencies uniquely determine these
coefficients. The gratings may contain conductors as well as dielectrics and
the boundaries of the conductors are also determined by the propagating modes.Comment: 12 page
Global Bounds for the Lyapunov Exponent and the Integrated Density of States of Random Schr\"odinger Operators in One Dimension
In this article we prove an upper bound for the Lyapunov exponent
and a two-sided bound for the integrated density of states at an
arbitrary energy of random Schr\"odinger operators in one dimension.
These Schr\"odinger operators are given by potentials of identical shape
centered at every lattice site but with non-overlapping supports and with
randomly varying coupling constants. Both types of bounds only involve
scattering data for the single-site potential. They show in particular that
both and decay at infinity at least like
. As an example we consider the random Kronig-Penney model.Comment: 9 page
Cardiac Surgery in Advanced Heart Failure.
Mechanical circulatory support and heart transplantation are established surgical options for treatment of advanced heart failure. Since the prevalence of advanced heart failure is progressively increasing, there is a clear need to treat more patients with mechanical circulatory support and to increase the number of heart transplantations. This narrative review summarizes recent progress in surgical treatment options of advanced heart failure and proposes an algorithm for treatment of the advanced heart failure patient at >65 years of age
The First INTEGRAL AGN Catalog
We present the first INTEGRAL AGN catalog, based on observations performed
from launch of the mission in October 2002 until January 2004. The catalog
includes 42 AGN, of which 10 are Seyfert 1, 17 are Seyfert 2, and 9 are
intermediate Seyfert 1.5. The fraction of blazars is rather small with 5
detected objects, and only one galaxy cluster and no star-burst galaxies have
been detected so far. A complete subset consists of 32 AGN with a significance
limit of 7 sigma in the INTEGRAL/ISGRI 20-40 keV data. Although the sample is
not flux limited, the distribution of sources shows a ratio of obscured to
unobscured AGN of 1.5 - 2.0, consistent with luminosity dependent unified
models for AGN. Only four Compton-thick AGN are found in the sample. Based on
the INTEGRAL data presented here, the Seyfert 2 spectra are slightly harder
(Gamma = 1.95 +- 0.01) than Seyfert 1.5 (Gamma = 2.10 +- 0.02) and Seyfert 1
(Gamma = 2.11 +- 0.05).Comment: 17 pages, 12 figures, accepted for publication in Ap
Cosmic X-ray background and Earth albedo Spectra with Swift/BAT
We use Swift/BAT Earth occultation data at different geomagnetic latitudes to
derive a sensitive measurement of the Cosmic X-ray background (CXB) and of the
Earth albedo emission in the 15--200 keV band. We compare our CXB spectrum with
recent (INTEGRAL, BeppoSAX) and past results (HEAO-1) and find good agreement.
Using an independent measurement of the CXB spectrum we are able to confirm our
results. This study shows that the BAT CXB spectrum has a normalization
~8(+/-3)% larger than the HEAO-1 measurement. The BAT accurate Earth albedo
spectrum can be used to predict the level of photon background for satellites
in low Earth and mid inclination orbits.Comment: Accepted for publication in the Astrophysical Journal. 38 Pages, 16
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