H.F. ionospheric radar ground-scatter map showing land-sea boundaries by a spectral-separation technique

Ionospherically propagated h.f. radio waves that have been backscattered from the sea can often be distinguished from those backscattered from land because of their different Doppler spectra. This characteristic has been exploited to generate an ionospheric radar map of the south-east United States from Boulder, Colo., by gating out the sea-scatter Doppler components. The agreement between the observed and actual land-sea boundaries is good.     

Extensive restriction site polymorphism at the human phenylalanine hydroxylase locus and application in prenatal diagnosis of phenylketonuria

A total of 10 restriction site polymorphisms have been identified at the human phenylalanine hydroxylase locus using a full-length human phenylalanine hydroxylase cDNA clone as a hybridization probe to analyze human genomic DNA. These polymorphic patterns segregate in a Mendelian fashion and concordantly with the disease state in various PKU kindreds. The frequencies of the restriction site polymorphisms at the human phenylalanine hydroxylase locus among Caucasians are such that the observed heterozygosity in the population is 87.5%. Thus, most families with a history of classical phenylketonuria can take advantage of the genetic analysis for prenatal diagnosis and carrier detection of the hereditary disorder.     

The frequency of disfluencies during phonatory transitions in stuttered and nonstuttered speech

The AA. investigated the frequency of antibodies against Toxoplasma gondii in 426 women with repeated abortions, perinatal mortality and malformed newborns. They showed on the whole a low incidence even if they demonstrated a high incidence (77.7%) of antibodies in women with malformed newborns. The meaning of the observations are briefly discussed.     

Tissue reactions induced by Schistosoma mansoni in Biomphalaria glabrata

In Biomphalaria glabrata with a strong natural resistance, Schistosoma mansoni sporocysts are rapidly encapsulated by granulocytes and killed, mainly by the strong phagocytic activity of the cells. Irradiated Echinostoma paraensei sporocysts seem able to suppress the function of the granulocytes. Tissue reactions in snails with self-cure demonstrate: involvement of two types of cells, granulocytes and hyalinocyte-like cells; formation of amoeba-fibrous capsules; limited tendency of granulocytes to become attracted to the parasites; a slow process of parasite destruction; and a possible involvement of humoral factors. It seems that there is partial suppression of the granulocyte function in smails with self-cure.     

Characterization of IS1547, a new member of the IS900 family in the Mycobacterium tuberculosis complex, and its association with IS6110

Unlike classically defined insertion sequence (IS) elements, which are delimited by their inverted terminal repeats, some IS elements do not have inverted terminal repeats. Among this group of atypical IS elements, IS116, IS900, IS901, and IS1110 have been proposed as members of the IS900 family of elements, not only because they do not have inverted terminal repeats but also because they share other features such as homologous transposases and particular insertion sites. In this study, we report a newly identified IS sequence, IS1547, which was first identified in a clinical isolate of Mycobacterium tuberculosis. Its structure, insertion site, and putative transposase all conform with the conventions of the IS900 family, suggesting that it is a new member of this family. IS1547 was detected only in isolates of the M. tuberculosis complex, where it had highly polymorphic restriction fragment length polymorphism patterns, suggesting that it may be a useful genetic marker for identifying isolates of the M. tuberculosis complex and for distinguishing different strains of M. tuberculosis. ipl is a preferential locus for IS6110 insertion where there are eight known different insertion sites for IS6110. Surprisingly, the DNA sequence of ipl is now known to be a part of IS1547, meaning that IS1547 is a preferential site for IS6110 insertion.