812 research outputs found
CMG2/ANTXR2 regulates extracellular collagen VI which accumulates in hyaline fibromatosis syndrome.
Loss-of-function mutations in capillary morphogenesis gene 2 (CMG2/ANTXR2), a transmembrane surface protein, cause hyaline fibromatosis syndrome (HFS), a severe genetic disorder that is characterized by large subcutaneous nodules, gingival hypertrophy and severe painful joint contracture. Here we show that CMG2 is an important regulator of collagen VI homoeostasis. CMG2 loss of function promotes accumulation of collagen VI in patients, leading in particular to nodule formation. Similarly, collagen VI accumulates massively in uteri of Antxr2 <sup>-/-</sup> mice, which do not display changes in collagen gene expression, and leads to progressive fibrosis and sterility. Crossing Antxr2 <sup>-/-</sup> with Col6a1 <sup>-/-</sup> mice leads to restoration of uterine structure and reversion of female infertility. We also demonstrate that CMG2 may act as a signalling receptor for collagen VI and mediates its intracellular degradation
The role of chiral loops in
We consider the rare decay and calculate the
non-resonant contribution to the amplitude to one loop in Chiral Perturbation
Theory. We display our result as both a diphoton energy spectrum and a partial
decay rate as a function of the photon energy cut. It turns out that the
one-loop correction can be numerically very important and could be detected, at
sufficiently large center-of-mass photon energies, from a measurement of the
partial decay width.Comment: 10 pages, Latex. Discussion on the resonant background enlarged, sign
error corrected, basic results unchanged. To appear in Phys. Lett.
Virtual Compton Scattering off the Pseudoscalar Meson Octet
We present a calculation of the virtual Compton scattering amplitude for the
pseudoscalar meson octet in the framework of chiral perturbation theory at
. We calculate the electromagnetic generalized polarizabilities
and compare the results in the real Compton scattering limit to available
experimental values. Finally, we give predictions for the differential cross
section of electron-meson bremsstrahlung.Comment: 9 pages, Latex, uses cjp3.sty (included), 4 eps figures, to be
published in the proceedings of the 13th Indian-Summer School "Understanding
the Structure of Hadrons," August 28 - September 1, 2000, Prague, Czech
Republi
Two-point function of strangeness-carrying vector-currents in two-loop Chiral Perturbation Theory
We calculate the correlator between two external vector-currents having the
quantum-numbers of a charged kaon. We give the renormalized expression to two
loops in standard chiral perturbation theory in the isospin limit, which, as a
physical result, is finite and scale-independent. Applications include a low
energy theorem, valid at two loop order, of a flavor breaking combination of
vector current correlators as well as a determination of the phenomenologically
relevant finite -counterterm combination by means of inverse
moment finite energy sum rules. This determination is less sensitive to
isospin-breaking effects than previous attempts.Comment: 24 pages, revtex, 4 figures, 2 tables, revised version, one ref.
adde
Theory of oscillations in the STM conductance resulting from subsurface defects (Review Article)
In this review we present recent theoretical results concerning
investigations of single subsurface defects by means of a scanning tunneling
microscope (STM). These investigations are based on the effect of quantum
interference between the electron partial waves that are directly transmitted
through the contact and the partial waves scattered by the defect. In
particular, we have shown the possibility imaging the defect position below a
metal surface by means of STM. Different types of subsurface defects have been
discussed: point-like magnetic and non-magnetic defects, magnetic clusters in a
nonmagnetic host metal, and non-magnetic defects in a s-wave superconductor.
The effect of Fermi surface anisotropy has been analyzed. Also, results of
investigations of the effect of a strong magnetic field to the STM conductance
of a tunnel point contact in the presence of a single defect has been
presented.Comment: 31 pages, 10 figuers Submitted to Low. Temp. Phy
Lifetimes of electrons in the Shockley surface state band of Ag(111)
We present a theoretical many-body analysis of the electron-electron (e-e)
inelastic damping rate of electron-like excitations in the Shockley
surface state band of Ag(111). It takes into account ab-initio band structures
for both bulk and surface states. is found to increase more rapidly as
a function of surface state energy E than previously reported, thus leading to
an improved agreement with experimental data
The effects of excluding patients from the analysis in randomised controlled trials: meta-epidemiological study
Objective To examine whether excluding patients from the analysis of randomised trials are associated with biased estimates of treatment effects and higher heterogeneity between trials
Effect of multidimensional lifestyle intervention on fitness and adiposity in predominantly migrant preschool children (Ballabeina): cluster randomised controlled trial
Objective To test the effect of a multidimensional lifestyle intervention on aerobic fitness and adiposity in predominantly migrant preschool children
- …