Is there a correlation between the number of mutagens and the number of nonmutagens in an environmental sample?

We have adapted a procedure which was developed for studying the correlations in the distribution of genetic factors, such as sex ratios in siblings, to obtain estimates of the correlation between the number of mutagens and the number of nonmutagens in a sample. Positive correlations with correlation coefficients in excess of 0.8 were obtained. The high correlation suggests that it is possible to estimate the number of mutagens in samples with N > 100 compounds as (0.064 ± 0.01) N.     

Zur Ursache,Form und Chemie der Gallensteine

Gallstones are precipitations of oversaturated bile fluid. They can develop in the gallbladder and in the efferent bile ducts; they are very often correlated with diseases of the gallbladder, bile ducts and neighboring organs. The gallstone disease (cholelithiasis) is increasing continually, especially in developed countries with overcaloric nourished population. Surgical interventions on the biliary tract are the most frequent abdominal operations at present.     

Soil infertility in the Amazonian rain forest

Extensive mineral alteration in the older land surfaces of the eastern Amazonian lowland has led to complete impoverishment of the soils in respect of their inorganic nutrient contents. Large-scale use of this area for agricultural purposes seems impossible. In the western Amazonian lowland, younger land surfaces (Pliocene) have developed along with Pleistocene flood plains. The mineral alteration in the soil profiles of this area, which are partly characterized by poor drainage, has resulted in impoverishment of soils to a lesser degree. These soils can be used to a limited extent for agricultural purposes, especially at the level of a subsistence economy.     

New denitrifying bacteria isolated from Red Sea sediments

Sediments of various newly discovered deeps in the Red Sea were analyzed for the occurrence of denitrifying bacteria. The samples were collected in 1972 during the Valdivia cruises. Among the 27 different samples investigated, 17 revealed both coccoid and rod-shaped bacteria when enriched in complex nutrient broth (with 10% NaCl). Denitrifiers were recorded abundantly in the sediments, their population decreasing from some 10⁶/g in the surface material to only a few in the subsediment. A total of 16 pure cultures of denitrifying bacteria were isolated from the Suakin-and Thetis-deeps and studied morphologically, physiologically and biochemically. Genetics (molar percentage of guanine plus cytosine, % GC) and numerical taxonomy were included to reveal relationships and improve taxonomic classification. Fifteen isolates were described as Gram-negative, aerobic and facultative anaerobic (with NO ₃ ^- as H⁺-acceptor), polarly flagellated rods (Pseudomonas spp.); one was an inmotile, Gram-positive, facultative anaerobic coccus. None of the 15 Pseudomonas-isolates could be identified with one of the denitrifying species so far described and recognized. The strains should be regarded as hitherto undescribed denitrifying marine bacteria.Supported by the Bundesministerium für Forschung und Technologie, Bonn, Germany (FRG).     

Trace metals in the hair of habitants of the Ok Tedi region, Papua New Guinea

It has long been known that mining activity can markedly change the level and distribution of certain heavy metals in the adjacent environment. This pollution can be quite widespread and long lasting and often has deleterious effects on the health of local populations. In the present study scalp hair was used as the biopsy material because of its ease of collection and long history of use in this connection. Hair was collected from all the local villages in the vicinity of the mine site, as well as from Papua New Guinean nationals from other provinces, and European expatriates who were employed by the mining company and who were resident in the area. Hair from local people showed a remarkably high iron content by comparison with previously studied populations. The extreme variations in hair iron levels were reflected in the differential distribution of levels according to location, age and sex. Hair cadmium was also high in the population studied. Hair copper, lead, zinc and mercury all appeared to be within 'normal' limits by comparison with other general populations. These results are discussed in the context of the environmental and social impact of the mining operations on the local people.