Dissociation between caloric and head impulse testing in patients with congenital abnormalities of the semicircular canals.

BACKGROUND: Dissociation between caloric and head impulse test results in patients with vestibular disorders has been well documented since the introduction of video head impulse testing. Prior to the introduction of video head impulse testing, vestibular diagnostic services relied mainly on caloric testing, and it is now known that the caloric testing shows more positive results than video head impulse testing. A dissipation model was proposed to explain this dissociation.Case reportsThis paper presents two cases in which caloric testing indicated an absent or significantly reduced response on the horizontal semicircular canal plane but video head impulse testing showed near-normal or normal vestibulo-ocular reflex gain on the same plane. CONCLUSION: This report supports the dissipation theory and questions the functional relevance of canal paresis values calculated from caloric test results.

Hypersharp resonant capture of neutrinos as a laboratory probe of the Planck length.

The 18.6 keV antineutrino (nue) line from the two-body decay of 3H in crystals can be emitted with a natural width because of motional averaging by lattice vibrations despite the very long lifetime of 3H and contrary to commonly held views of linewidths in such a case. It can be resonantly captured in 3He with geometrical cross section sigma approximately 10(-17) cm2. Using its hypersharp sensitivity DeltaE/E approximately 10(-29) and the method of "time-filtered" resonance, the basic energy width approximately 10(-24) eV expected of the 3H state can be measured to test if ultimate nuclear widths are limited by the Planck length rather than time-energy uncertainty.

Probing the temperature profile of energy production in the sun.

The particle kinetic energies of thermonuclear pp fusion in the Sun (Gamow energy) produce small changes in the energies of pp solar neutrinos relative to those due only to exothermal energetics. This effect may be observable via the unique tools of the LENS solar neutrino detector. The temperature profile of energy production in the Sun may thus be directly probed for the first time.

Solar neutrinos--from puzzle to paradox.

The solar neutrino puzzle is deepening into a paradox that refutes the basic logic of the reaction chain that powers the sun by the fusion of protons into heavy elements. Experiments now reveal a serious anomaly in the relative neutrino fluxes from the different steps in the chain. Neutrinos from boron-8 at the end of the chain are seen but hardly any are seen from beryllium-7, without which the observed boron-8 cannot be made. The only apparent way to avoid a paradoxical "missing link" in the sun's energy chain is a nonzero neutrino mass, an idea that can be tested in future experiments.