ALBERT

Notes: Summary The paper describes a new portable highly sensitive dual-frequency electromagnetic prospecting unit designed for detailedem surveys based on moving source compensation method. Employing horizontal-horizontal coil profiling, the unit is capable of working on a source-receiver separation of 330 feet (ninety meters) on both frequencies of 500 cycles per sec and 1500 cycles per sec to an accuracy of ±1%. The presence of secondary field characterised by two related components ‘in-phase’ and ‘out-of-phase’ are measured accurately to define the conductor characteristics. An unique provision is made for compensating the phase-shifts in the presence of medium to poor conductors, such as conductive overburden or relatively disseminated ore mineralisation.

Notes: Decisions to develop water resources systems so far have been primarily taken on the basis of engineering and economic feasibilities. Very rarely, if ever, sociological feasibility has been considered, except in a very broad sense. Planning is for the people, and it should improve the quality of life. Hence, it is argued that water resources decisions ought to be primarily social ones, and that the success or failure of any resource development should not only be judged by its techno-economic excellence but also by its impact on people.Water resources planning process is discussed, and the difficulties associated with the evaluation of sociological feasibility of projects are enumerated. The social consequences of water development projects are traced through planning, construction, operation and management impacts. Finally, it is suggested that the foremost factor in the success of any water management program is the public understanding and acceptance of that program.

Notes: BOOK REVIEWS

Notes: Summary Interactions of cationic dye methylene blue with small polyanions like inositol hexasulfate, adenosine-triphosphate, ammonium molybdate, potassium ferro- and ferricyanide have been studied spectrophotometrically and conductometrically to ascertain the chromotropic characters of these polyanions. Results show that while almost all of them bind the dye stoichiometrically, none of them except ammonium molybdate is a chromotrope in the sense in which heparin, chondroitin sulfate etc. are. Inositol hexasulfate induces an intermediate spectra, though not perfectly metachromatic as is the case with inositol hexaphosphate. It is concluded that a chromotrope need not be a macromolecule to induce metachromasia in a dye solution, but the minimum number of charges per polyanion to give it a chromotropic character will vary with the nature of the polyanion.

Notes: Abstract The measurements of the hard X-ray spectrum of Sco X-1 in the energy interval 20–150 keV in three balloon flights from Hyderabad, India are reported. These results show conclusively that the spectrum of Sco X-1 is very flat in the energy interval 40–150 keV and the measured fluxes beyond 60 keV are several orders of magnitude higher than those expected on the basis of an extrapolation of bremsstrahlung spectrum from a thin hot plasma at a temperature corresponding tokT=5 keV, which is applicable for Sco X-1 for energies 〈40 keV. The results are compared with those of other investigators of hard X-rays from Sco X-1, and the implication of the results is briefly discussed.

Notes: Summary Transformations of two linked ribosomal loci (str and ery) were carried out between the SIII-1 strain of pneumococcus and the Challis and SBE strains of group H streptococcus. Transfer of markers between the Challis and SBE strains is as efficient as in the corresponding intrastrain transformations. Transfer between either of these strains and the pneumococcus, however, is less efficient than in the corresponding intrastrain transformation, and is referred to as heterospecific transformation. The inefficiency of the heterospecific transformation is due neither to specific lethality nor reduced uptake of heterologous DNA. When DNA was extracted from the hybrid resulting from a heterospecific cross and used to transform the original donor and recipient species, we found: (a) no donor material in the hybrid DNA responsible for the markedly low efficiency of integration into the recipient species; (b) donor material, in addition to the transforming marker itself, detectable by the higher efficiency with which hybrid DNA transforms the original donor species than does DNA from the original recipient species. DNA was extracted from each of 36 independently derived, doubly marked transformants resulting from the cross: Challis str-s ery-sxSIII-1 str-r53 ery-r2 DNA. Variability was observed between the different hybrid DNAs when the integration efficiency of the str marker in each DNA was compared with that of the ery marker. Variability of as great a magnitude was not observed when the same hybrid DNA was tested in repeated experiments, or when different DNA preparations were extracted from the same hybrid strain, or when several DNA preparations were obtained from a number of independent homospecific transformants. It is concluded that different kinds of donor material are present in the various hybrids, and that the nature of this extra-marker material affects the integration of the marker. Linkage of the str and ery markers was reduced in heterospecific transformations. The kind of donor DNA in the hybrid genome did not affect the linkage reduction observed when the str and ery markers were transferred back to the donor species in which they originated. Indeed, this linkage reduction was the same as that observed when the markers were originally transferred from the SIII-1 to the Challis strain. Specific factors reducing linkage in heterologous crosses must, therefore, be distinct from other factors which affect integration efficiency. The former, however, may be primarily responsible for the inefficiency of heterospecific transformation. One of the hybrid DNAs was used to obtain a second generation of hybrids by passing it through each of the original parental strains. Tests of the DNAs extracted from 24 independently produced, second-generation hybrids showed that hybrid DNA is subject to further alteration by a second integration involving some heterologous confrontation. The probability of such alteration appears to be increased if the second integration is accompanied by linkage reduction.

Notes: Summary The effect of various doses of gamma irradiation on the development of Schistosoma incognitum cercariae have been investigated in mice. A marked resistance to a subsequent challenge infection with normal cercariae was observed in mice doubly vaccinated with irradiated cercariae. Experiments on the passive transfer of immunity had failed to demonstrate a significant degree of resistance by this vaccination procedure.