The effects of diazepam on intrinsic laryngeal muscle activation during respiration and speech

Electromyographic recordings of intrinsic laryngeal muscles were made during respiration, phonation, speech, and swallow in three subjects in two conditions: with and without intravenous administration of 5 mg of diazepam. The mean activity in microvolts of the thyroarytenoid and cricothyroid muscles was measured during respiration and the percentage increase over resting levels during inspiration, expiration, swallow, phonation, and speech. All subjects demonstrated significant (p ≤ 0.001) reductions in mean activity during respiration with diazepam. Significant (p ≤ 0.001) diazepam, subject, and subject by diazepam interactions were found in the percentage increase in muscle activation on each task. In one subject muscle activity consistently decreased, while in the other two subjects it consistently increased with diazepam. Although all had significant muscle relaxant effects, individuals differed in their diazepam responses during muscle activation. These differences may relate to a subject's age.     

Scalar field of nonparaxial Gaussian beams

A family of closed-form expressions for the scalar field of strongly focused Gaussian beams in oblate spheroidal coordinates is given. The solutions satisfy the wave equation and are free from singularities. The lowest-order solution in the far field closely matches the energy density produced by a sine-condition, high-aperture lens illuminated by a paraxial Gaussian beam. At the large waist limit the solution reduces to the paraxial Gaussian beam form. The solution is equivalent to the spherical wave of a combined complex point source and sink but has the advantage of being more directly interpretatable.     

p-Wave cold collisions in an optical lattice clock

We study ultracold collisions in fermionic ytterbium by precisely measuring the energy shifts they impart on the atoms' internal clock states. Exploiting Fermi statistics, we uncover p-wave collisions, in both weakly and strongly interacting regimes. With the higher density afforded by two-dimensional lattice confinement, we demonstrate that strong interactions can lead to a novel suppression of this collision shift. In addition to reducing the systematic errors of lattice clocks, this work has application to quantum information and quantum simulation with alkaline-earth atoms.