The objective of this study was to investigate the role of serotonin (5-HT) in mediating the effects of cocaine in humans. To accomplish this, 12 subjects each participated in two randomized, double-blind test sessions separated by 1 week. In one session, subjects underwent acute depletion of the 5-HT amino acid precursor tryptophan (TRP), followed by a test dose of intranasal cocaine. In the other session, the cocaine test dose was preceded by sham depletion. Subject ratings of cocaine "high" were significantly lower following active TRP depletion than after the sham procedure. Subjects also showed an earlier but less sustained rise in self-rated nervousness during active TRP depletion. These findings are consistent with the hypothesis that 5-HT may be involved in mediating the euphorigenic and modulating the anxiogenic effects of cocaine in humans, either directly or through actions on other (e.g., dopaminergic) systems.

A monolayer adsorbed on a crystal surface may form an overlayer whose unit-cell dimension in one or both principal directions is very long compared with the substrate lattice constant (5 -15 lattice constants, for example). We refer to such overlayers as nearly incommensurate.In this paper, we explore the lattice vibrations of such overlayers, within a model where the substrate is viewed as rigid, providing a corrugated potential well within which the adsorbates reside. We first find the static equilibrium configuration of the adlayer, and then calculate the phonon spectrum and meansquare displacements within harmonic lattice dynamics. For small corrugation amplitudes, we find very large mean-square displacements parallel to the surface. There is a smooth transition to a regime where the overlayer is locked to the substrate tightly; the transition occurs within a rather narrow range of corrugation strengths. This and other systematic aspects of the vibrational properties of such overlayers are explored in the paper.

THE following notes are founded on observations on 685 cases of gas poisoning which came under treatment in a casualty clearing station between May 2nd and May 7tl, 1915. The patients were brought in by motor ambulance convoys from the field ambulances-a journey of about ten miles. Some arrived only six lhours after being "gassed," wlhile in other cases a muclh longer period had elapsed before ;they were brought in." Tiley were detained in tlle casualty clearing station only until they were deemed fit to evacuate to the base. The slighter cases were sent down at the earliest possible moment, the mlajority were evacuated within forty-eiglht hours, while Fourteen men died out of the first batch of seventeen admitted.Among the hundreds of cases subsequently observed, all degrees of asphyxia were evident, and it is difficult to convey a composite clinical picture of all of these. Certain common features, however, stood out so prominently that our purpose will be served by calling attention to them.Certain of these have been alluded to already.The typical case was on admission cold, with a subnormal temperature, conscious but restless, the pulse slow and full (except in the collapsed cases). The face was cyanosed, intensely so in many cases, and tlle expression was strained and anxious. Nearly all the cases on admission were in the first or asphyxial stage, whiclh lhas just been described. This condition demanded immediate and energetic treatment, and was that whiclh chiefly occupied us at the casualty clearing station. Grave symptoms appeared with startling suddenness, but if patients could be safely brouglht through this stage, recovery was tlle rule.The first stage gradually passed off after some thirty-six hours, and the patient fell into a sleep from which he woke feeling muclh better. He continued in this state for perhaps lhalf a day, and during this period every effort was made to evacuate hiim safely to tlle base.After these few 1oULrs of comparative quiet, symptoms of bronchitis began to manifest themselves. In the majority of cases, as far as our experience went, these were not severe. In the cases, however, which had been kept alive with difficulty there was a very short quiescent stage, followed by intense bronchitis. Four of the most severe cases died in this bronchitic stage. Their sym. ptoms, as compared with the first stage, were as follows : 'rlie frothing secretion gave way to thick greenish mucopurulent expectoration, consciousness was replaced by delirium, temperature rose from subnormal up to -1040 F., and the pulse became of small volume, white its rate increased to perhaps 160. Respirations were less choking, but more shallow, and numbered up to 70 per minute before death. TREATMENT.As po8t-mortemn examination showed that the patients died of acute congestion and oedema of the lungs, the aim of our treatment was:1. To expel the excessive secretion from the lungs by emetics and stimulating expectorants.