An update on feline infectious peritonitis: diagnostics and therapeutics.

This review is concerned with what has been learned about feline infectious peritonitis (FIP) diagnostics and therapeutics since the publication of an extensive overview of literature covering the period 1963-2009. Although progress has been made in both areas, obtaining a definitive diagnosis of FIP remains a problem for those veterinarians and/or cat owners who require absolute certainty. This review will cover both indirect and direct diagnostic tests for the disease and will emphasize their limitations, as well as their specificity and sensitivity. There is still no effective treatment for FIP, although there are both claims that such therapies exist and glimmers of hope coming from new therapies that are under research. FIP has also been identified in wild felids and FIP-like disease is now a growing problem among pet ferrets

Limits of slow-light in photonic crystals

While ideal photonic crystals would support modes with a vanishing group velocity, state-of-the art structures have still only provided a slow-down by roughly two orders of magnitude. We find that the induced density of states caused by lifetime broadening of the electromagnetic modes results in the group velocity acquiring a finite value above zero at the band gap edges, while attaining superluminal values within the band gap. Simple scalings of the minimum and maximum group velocities with the imaginary part of the dielectric function or, equivalently, the linewidth of the broadened states, are presented. The results obtained are entirely general and may be applied to any effect which results in a broadening of the electromagnetic states, such as loss, disorder, finite-size effects, etc. This significantly limits the reduction in group velocity attainable via photonic crystals.Comment: 5 pages, 3 figures, accepted for Physical Review

Null-Wave Giant Gravitons from Thermal Spinning Brane Probes

We construct and analyze thermal spinning giant gravitons in type II/M-theory based on spherically wrapped black branes, using the method of thermal probe branes originating from the blackfold approach. These solutions generalize in different directions recent work in which the case of thermal (non-spinning) D3-brane giant gravitons was considered, and reveal a rich phase structure with various new properties. First of all, we extend the construction to M-theory, by constructing thermal giant graviton solutions using spherically wrapped M2- and M5-branes. More importantly, we switch on new quantum numbers, namely internal spins on the sphere, which are not present in the usual extremal limit for which the brane world volume stress tensor is Lorentz invariant. We examine the effect of this new type of excitation and in particular analyze the physical quantities in various regimes, including that of small temperatures as well as low/high spin. As a byproduct we find new stationary dipole-charged black hole solutions in AdS_m X S^n backgrounds of type II/M-theory. We finally show, via a double scaling extremal limit, that our spinning thermal giant graviton solutions lead to a novel null-wave zero-temperature giant graviton solution with a BPS spectrum, which does not have an analogue in terms of the conventional weakly coupled world volume theory.Comment: v1: 31p

On the Influence of Force Distribution and Boundary Condition on Helical Gear Stiffness

The gear stiffness has a direct influence on the dynamic response of transmission systems that include a gear box, the stiffness also controls the load distribution among the teeth in mesh. The stiffness of a gear tooth varies non-linearly as the contact line with the meshing gear tooth moves along the surface of the tooth and the resulting meshing stiffness also includes discontinuities. The stiffness estimation for helical gears can only be done using full 3D analysis contrary to spur gears where 2D often suffice. Besides the usual gear geometry defined by standards two factors are found to have a large influence on the stiffness. These two factors are the rim thickness included in the stiffness calculation and the contact zone size. In the contact zone the distribution of the load is also shown to be important. Simple possible simplifications in relation to the contact load distribution are presented. The gear stiffness is found using the elastic energy of the loaded tooth. In the finite element calculation the true gear tooth root profile is applied