University infirmary admissions for drug abuse, 1968--1970 and 1973--1975.

University overnight infirmary admissions for drug abuse were reviewed over the 2-year periods 1968--1970 and 1973--1975. Hallucinogen abuse diminished over the years studied while alcohol abuse increased. Marijuana abuse was essentially unchanged.

Hepatitis B surface antigenaemia in Kenyans with chronic liver disease.

Fifty Kenyan patients with chronic liver disease or hepatocellular carcinoma were tested for hepatitis B surface antigenaemia by radioimmunoassay. The hepatitis B surface antigen was detected in 77% of the patients with chronic persistent or chronic aggressive hepatitis, or cirrhosis confirmed by liver biopsy, compared with 15% in a control group. All six patients with hepatocellular carcinoma had detectable hepatitis B surface antigen or antibody.

Intention myoclonus: successful treatment with clonazepam.

Clonazepam, a new benzodiazepine derivative, was used in the treatment of intention myoclonus with excellent results. Five patients, three with postanoxic encephalopathy and two with degenerative central nervous system disorders, all refractory to other therapy, responded with marked decrease in myoclonus. The effective dosage was 7 to 12 mg a day in divided doses.

Hepatitis Bs antigen and liver cancer: A population based study in Kenya.

Peers and Linsell (1973) demonstrated a significant association between the incidence of primary liver cancer and ingested aflatoxin in a study in the Muranga district of Kenya. A study of hepatitis B antigen in the same district showed no significant differences between the low altitude area, with a relatively high incidence of primary liver cancer, and the high altitude area with a lower incidence of the tumour. Current evidence is more in favour of aflatoxin playing an important role in the aetiology of primary liver cancer but hepatitis B antigen may play an ancillary role.

New seismic data on the state of the deep lunar interior.

Direct shear-wave arrivals from seismtic events originating on the far side of the moon are not observed at some of the stations of the Apollo seismic network. These data suggest that the material in the lunar interior at a depth of 1000 to 1100 kilometers is more dissipative for seismic shear waves than the lithosphere above, and possibly exists in a partially molten state akin to the earth's asthenosphere.

Lunar crust: structure and composition.

Lunar seismic data from artificial impacts recorded at three Apollo seismometers are interpreted to determine the structure of the moon's interior to a depth of about 100 kilomneters. In the Fra Mauro region of Oceanus Procellarum, the moon has a layered crust 65 kilometers thick. The seismic velocities in the upper 25 kilometers are consistent with those in lunar basalts.

Moonquakes.

Although the average rate of seismic energy release within the moon appears to be far below that of the earth, over 100 events believed to be moonquakes have been recorded by the two seismic stations installed on the lunar surface during Apollo missions 12 and 14. With few exceptions, the moonquakes occur at monthly intervals near times of perigee and apogee and show correlations with the longer-term (7-month) lunar gravity variations. The repeating moonquakes are believed to occur at not less than 10 different locations.

Seismic data from man-made impacts on the moon.

Unusually long reverberations were recorded from two lunar impacts by a seismic station installed on the lunar surface by the Apollo 12 astronauts. Seismic data from these impacts suggest that the lunar mare in the region of the Apollo 12 landing site consists of material with very low seismic velocities near the surface, with velocity increasing with depth to 5 to 6 kilometers per second (for compressional waves) at a depth of 20 kilometers. Absorption of seismic waves in this structure is extremely low relative to typical continental crustal materials on earth.

Passive seismic experiment.

Seismometer operation for 21 days at Tranquillity Base revealed, among strong signals produced by the Apollo 11 lunar module descent stage, a small proportion of probable natural seismic signals. The latter are long-duration, emergent oscillations which lack the discrete phases and coherence of earthquake signals. From similarity with the impact signal of the Apollo 12 ascent stage, they are thought to be produced by meteoroid impacts or shallow moonquakes.