Alvin Novick

Cochlear Microphonic Audiograms in the "Pure Tone" Bat Chilonycteris parnellii parnellii

Audiograms are sharply tuned to a frequency close to the second harmonic of the pulse. The tuning, which is much sharper than previously reported for any vertebrate receptor, provides a mechanism whereby the bat can effectively perceive echoes even during periods of pulse-echo overlap.

Orientation In Neotropical Bats. II Phyllostomatidae and Desmodontidae

The orientation sounds of Chilonycteris rubiginosa, C. personata, Pteronotus, Macrotus, Glossophaga, Leptonycteris, Artibeus (Phyllostomatidae), and Desmodus (Desmodontidae) were analyzed for frequency, frequency pattern, and duration. All of these bats produce ultrasonic orientation pulses of both a frequency modulated and harmonic pattern. Ordinarily at least two harmonic components characterize the onsets of pulses with additional harmonics commonly occurring later on. There is an invariable frequency drop, usually less than one octave, from beginning to end of each pulse. The rate of frequency drop may be irregular, especially so in C. rubiginosa , characterized as well by long pulses. Glossophaga produce sounds of unusually high frequency (up to 208 kc) and short duration. No generalities seem to characterize the frequency and duration of phyllostomatid sounds.

Orientation in Neotropical Bats. I. Natalidae and Emballonuridae

The orientation pulses of Natalus (Natalidae) have been recorded for the first time. These pulses are of a frequency modulated design with an initial frequency of about 85 kc and a terminal frequency of about 40 kc (roosting) or 55 kc (flying). A second harmonic component is also present. Pulses average 2.5 msec in duration. The orientation pulses of Balantiopteryx ( Emballonuridae ) are of a harmonic pattern with a slight fundamental frequency drop of 3–4 kc from beginning to end. Initially the fundamental of about 20 kc is accompanied by its second and third harmonics. These pulses average 3.2 msec in flight and are very similar to previously described pulses of Taphozous and Saccopteryx .

Pulse Duration in the Echolocation of Insects by the Bat, Pteronotus

The pulse durations of the orientation sounds of the bat, Pteronotus, are progressively shortened during the pursuit of a fruit-fly. If the position of the bat is calculated for each pulse, the echo from the fly is found to overlap the pulse by about 1.5 msec, in the approach phase, and by about 1.0 msec, in the terminal phase of each pursuit. Such pulse-echo overlaps has not previously been demonstrated in bats.

Self-Deferral, HIV Infection, and the Blood Supply: Evaluating an AIDS Intervention.

This article evaluates the effectiveness of self-deferral, a social screen implemented to protect the U.S. blood supply from HIV infection prior to the advent of laboratory testing of donated blood. Following a brief discussion of the history of this program, mathematical models are developed to estimate the number of infectious transfusions ultimately leading to AIDS that occurred prior to self-deferral. The analysis suggests that a significant percentage of the maximum number of AIDS-indicated infectious transfusions preventable were averted during the 2 years from implementation of self-deferral to the start of laboratory screening.

Civil Disobedience in Time of AIDS

In the face of what they view as continuing governmental indifference and neglect, persons with AIDS have turned to civil disobedience to affect public policy. Novick develops the background to the use of civil disobedience by AIDS activists as a form of protest and explains the interface between AIDS activists, many of whom are members of the gay community, and society. He argues that civil disobedience is justified in the face of the governments failure to develop a comprehensive national agenda on AIDS and to address the issues of access to health care, to new therapies, and to rational, sensitive health promotion.

A Critique of Schüklenk and Brookey: “Biomedical Research on Sexual Orientation: Researchers Taking Our Chances in Homophobic Societies”

In their paper in the previous issue of the Journal of the Gay and Lesbian Medical Association, Schüklenk and Brookey warn that research on the causes of sexual orientation may be dangerous. They develop several themes of which the most radical appear to be that “research has no value of its own” and that the products of research may be used for evil purposes, that we should greatly fear advances in knowledge, and (at least by implication) that we should put a stop to research and to advancing knowledge on the origins of sexual orientation. The present critique attempts to place their themes in a different context.