Treatment of dogs with compensated myxomatous mitral valve disease with spironolactone-a pilot study

Spironolactone improves outcome in dogs with advanced myxomatous mitral valve disease (MMVD). Its efficacy in preclinical MMVD is unknown. The hypothesis was the administration of spironolactone to dogs with compensated MMVD demonstrating risk factors for poorer prognosis will decrease the rate of disease progression. The aim was to provide pilot data to evaluate preliminary effects and sample size calculation for a definitive clinical trial

Mediators of mechanotransduction between bone cells

Mechanical forces are known to regulate the function of tissues in the body, including bone. Bone adapts to its mechanical environment by altering its shape and increasing its size in response to increases in mechanical load associated with exercise, and by decreasing its size in response to decreases in mechanical load associated with microgravity or prolonged bed rest. Changes in bone size and shape are produced by a cooperative action of two main types of the bone cells - osteoclasts that destroy bone and osteoblasts that build bone. These cell types come from different developmental origins, and vary greatly in their characteristics, such as size, shape, and expression of receptor subtypes, which potentially may affect their responses to mechanical stimuli. The objective of this study is to compare the responses of osteoclasts and osteoblasts to mechanical stimulation. This study has allowed us to conclude the following: 1. A mediator is released from a single source cell. 2. The response to the mediator changes with distance. 3. The value of the apparent diffusion coeficient increases with distance. 4. A plausible proposed mechanism is that ATP is released and degrades to ADP. 5. Future experiments are required to confim that ATP is the mediator as suggested

How large is the spreading width of a superdeformed band?

Recent models of the decay out of superdeformed bands can broadly be divided into two categories. One approach is based on the similarity between the tunneling process involved in the decay and that involved in the fusion of heavy ions, and builds on the formalism of nuclear reaction theory. The other arises from an analogy between the superdeformed decay and transport between coupled quantum dots. These models suggest conflicting values for the spreading width of the decaying superdeformed states. In this paper, the decay of superdeformed bands in the five even-even nuclei in which the SD excitation energies have been determined experimentally is considered in the framework of both approaches, and the significance of the difference in the resulting spreading widths is considered. The results of the two models are also compared to tunneling widths estimated from previous barrier height predictions and a parabolic approximation to the barrier shape

Mixed-mode impedance and reflection coefficient of two-port devices

From the point of view of mixed-mode scattering parameters, Smm, a two-port device can be excited using different driving conditions. Each condition leads to a particular set of input reflection and input impedance coefficient definitions that should be carefully applied depending on the type of excitation and symmetry of the two-port device. Therefore, the aim of this paper is to explain the general analytic procedure for the evaluation of such reflection and impedance coefficients in terms of mixed-mode scattering parameters. Moreover, the driving of a two-port device as a one-port device is explained as a particular case of a two-port mixed-mode excitation using a given set of mixed-mode loads. The theory is applied to the evaluation of the quality factor, Q, of symmetrical and non- symmetrical inductors.Ministerio de Innovación y Ciencia TEC2010-14825/MIC, TEC2010-21484Junta de Andalucía TIC-253

MeV Right-handed Neutrinos and Dark Matter

We consider the possibility of having a MeV right-handed neutrino as a dark matter constituent. The initial reason for this study was the 511 keV spectral line observed by the satellite experiment INTEGRAL: could it be due to an interaction between dark matter and baryons? Independently of this, we find a number of constraints on the assumed right-handed interactions. They arise in particular from the measurements by solar neutrino experiments. We come to the conclusion that such particles interactions are possible, and could reproduce the peculiar angular distribution, but not the rate of the INTEGRAL signal. However, we stress that solar neutrino experiments are susceptible to provide further constraints in the future.Comment: 7 pages, figure 1 changed, added reference

Final-state interaction phase difference in J/ψ→ρηJ/\psi\to\rho\eta and ωη\omega\eta decays

It is shown that the study of the $\omega-\rho^0$ interference pattern in the $J/\psi\to (\rho^0+\omega)\eta\to\pi^+\pi^-\eta$ decay provides the evidence for the large (nearly $90^\circ$) relative phase between the one-photon and the three-gluon decay amplitudes.Comment: 5 pages, revtex, \tightenlines, a version published in Phys. Rev. D 61, 117504 (2000

The Composite Fermion Hierarchy: Condensed States of Composite Fermion Excitations?

A composite Fermion hierarchy theory is constructed in a way related to the original Haldane picture by applying the composite Fermion (CF) transformation to quasiparticles of Jain states. It is shown that the Jain theory coincides with the Haldane hierarchy theory for principal CF fillings. Within the Fermi liquid approach for few electron systems on the sphere a simple interpretation of many-quasiparticle spectra is given and provides an explanation of failure of CF hierarchy picture when applied to the hierarchical $4/11$ state.Comment: 6 pages, Revtex, 4 figures in PostScript, submitted to Phys. Rev. Let

Quantum Monte Carlo study of the Ne atom and the Ne+ ion

We report all-electron and pseudopotential calculations of the ground-stateenergies of the neutral Ne atom and the Ne+ ion using the variational and diffusion quantum Monte Carlo (DMC) methods. We investigate different levels of Slater-Jastrow trial wave function: (i) using Hartree-Fock orbitals, (ii) using orbitals optimized within a Monte Carlo procedure in the presence of a Jastrow factor, and (iii) including backflow correlations in the wave function. Small reductions in the total energy are obtained by optimizing the orbitals, while more significant reductions are obtained by incorporating backflow correlations. We study the finite-time-step and fixed-node biases in the DMC energy and show that there is a strong tendency for these errors to cancel when the first ionization potential (IP) is calculated. DMC gives highly accurate values for the IP of Ne at all the levels of trial wave function that we have considered