Biomedical subjects

M V Berry

Publications and source records attributed to M V Berry.

3 recordsLinked to original sources

PubMed2002

Exuberant interference: rainbows, tides, edges, (de)coherence...

Young's pioneering studies of interference have led to fundamental developments in wave physics. Supernumerary rainbows were the first example of diffraction associated with caustics. Cotidal lines (connecting places where the tide is high at a given time) were the first example of wavefronts in the modern sense (pattern of phase contours (arg psi(1) + psi(2)) of the superposition of waves psi(1) and psi(2), rather than the superposed patterns of the separate phases arg psi(1) and arg psi(2)), and led to the discovery of phase singularities. Edge-diffracted waves extend the range of asymptotic methods applied to waves and continue to find diverse and unexpected applications. Young's understanding of the conditions for observing interference are now part of decoherence theory, which explains, for example, the emergence of the classical world from the quantum world.

Interferometry↗

PubMed1996

Colored diffraction catastrophes.

On fine scales, caustics produced with white light show vividly colored diffraction fringes. For caustics described by the elementary catastrophes of singularity theory, the colors are characteristic of the type of singularity. We study the diffraction colors of the fold and cusp catastrophes. The colors can be simulated computationally as the superposition of monochromatic patterns for different wavelengths. Far from the caustic, where the luminosity contrast is negligible, the fringe colors persist; an asymptotic theory explains why. Experiments with caustics produced by refraction through irregular bathroom-window glass show good agreement with theory. Colored fringes near the cusp reveal fine lines that are not present in any of the monochromatic components; these lines are explained in terms of partial decoherence between rays with widely differing path differences.

Journal Article↗

PubMedDate not supplied

The surgical treatment of osteochondritis of the capitellum.

This paper reviews 14 patients who underwent elbow arthrotomy for osteochondritis of the capitellum. The etiology in 7 of the 14 cases appears to be the result of repeated trauma from throwing sports. Five of the 14 described a singular significant traumatic episode, and in 2 of the 14, a clear etiology is uncertain. The diagnostic features including signs, symptoms, and elbow range of motion are examined. The operative findings are correlated with plain x-ray films of the elbow in all cases and with an elbow arthrogram in 11 out of 14 cases. The average length of followup was 24 months. The postoperative range of motion was increased an average of 18 degrees. Eighty-six percent (12 out of 14) patients returned to organized, competitive athletic activity without restrictions. The Little League background of those patients with apparent repetitive microtrauma to the elbow is examined in terms of length of pitching experience and types of pitches thrown. In addition, the throwing mechanism of these patients is evaluated with respect to the type of delivery at possible risk for the development of osteochondritis. We conclude that after a failure of conservative therapy, surgical treatment, including removal of the intraarticular loose bodies, excision of capitellar lesions, and curettage to bleeding bone can be expected to produce pain relief and improvement in joint motion. A return to organized competitive sport activities can be expected.

Adolescent↗