Periodic variability in cetacean strandings: links to large-scale climate events.

Cetacean strandings elicit much community and scientific interest, but few quantitative analyses have successfully identified environmental correlates to these phenomena. Data spanning 1920-2002, involving a total of 639 stranding events and 39 taxa groups from southeast Australia, were found to demonstrate a clear 11-13- year periodicity in the number of events through time. These data positively correlated with the regional persistence of both zonal (westerly) and meridional (southerly) winds, reflecting general long-term and large-scale shifts in sea-level pressure gradients. Periods of persistent zonal and meridional winds result in colder and presumably nutrient-rich waters being driven closer to southern Australia, resulting in increased biological activity in the water column during the spring months. These observations suggest that large-scale climatic events provide a powerful distal influence on the propensity for whales to strand in this region. These patterns provide a powerful quantitative framework for testing hypotheses regarding environmental links to strandings and provide managers with a potential predictive tool to prepare for years of peak stranding activity.

X-chromosomal DNA polymorphisms in two ethnic groups from India.

Four polymorphic sites of the short arm of the X chromosome were studied in two racial groups from India, the Assamese and the Malayalee. Since the allelic frequencies of the two groups did not differ markedly from each other, the data from the two populations were pooled. The frequency of the A2 allele was 0.57 for the L1.28 probe, 0.20 for the RC8 probe, 0.28 for the pD2 probe and 0.11 for the L754 probe. The A3 allelic fragment of the RC8 probe was not found among 67 Indians, and in one Assamese woman an additional 7.0-kilobase fragment was found. The differences between the Indian population and other ethnic groups were analyzed.

Four DNA polymorphisms on the short arm of the X chromosome: allele frequencies in a German and in a Turkish population.

Four restriction fragment length polymorphisms, revealed by cloned arbitrary X chromosome segments (L1.28, RC8, pD2, 754) were studied in samples (50 individuals each) of a German and a Turkish population. All previously reported alleles of these polymorphisms were found in both populations, except the infrequent RC8 allele B3 (3.0 kb fragment), which was absent in both groups. The observed minor alleles were found to be rarer in the German series than in the Turkish group, but there was no conclusive evidence of essentially different allele frequencies in either population. However, the frequencies of the RC8 allele B2 (5.3 kb fragment) were differing at the 5% significance level. The allele frequencies of the four polymorphisms are presented and compared with those reported from other European regions.