Distribution of 222Rn in groundwater and estimation of resulting radiation dose to different age groups: A case study from Bangalore City

Ingesting waters holding high levels of natural occurring radioactive element like Radon would contribute to increase in the effective dose received by people followed by an increased prevalence of cancer. The current study is an attempt to describe the extent of contribution of ²²²Rn to natural background radiation and the resultant effective dose to public of different age groups. In order to do so, 65 groundwater samples from selected parts of Bangalore city were collected and analyzed for radon activity using RAD7 radon monitor coupled with RAD H₂O accessories. The radon activity was in the range of 3.05–696 Bq/L (mean: 91.39 Bq/L) and 92.31% of the groundwater samples recorded elevated radon concentration above the United States environmental protection agency (USEPA's) Maximum Contaminant Level (MCL) value of 300 pCi/L, corresponding to 11.1 Bq/L. The mean annual effective dose contribution of people falling under different age groups (viz., infants, children, teens: males and females, adults: males and females, pregnant and lactating women) due to ingestion of water-borne ²²²Rn ranged from 0.082 to 0.444 mSv/y and was found to be higher in all the age groups of males compared to respective female age groups, but well within the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and World Health Organization (WHO) proposed limit of 1 mSv/y.     

Studies on the phytoplankton of the River Ganges,Varanasi, India Part IV “Phytoplankton in relation to fish population”

Summary A detailed and systematic study of the algae present in the guts of several fishes from the river and their percentage composition was carried out. Only a few fishes like Hilsa ilisha, Gadusia chapra and Barbus stigma showed herbivorous and omnivorous habits. Definite grazing of the phytoplankton by fishes was clearly envisaged. Their comparative preference for diatoms was evident.     

A comparative study on permeabilization treatments for in situ determination of phytase of Rhodotorula gracilis

Rhodotorula gracilis , a red yeast, was shown to produce phytase and the cultural conditions were standardized for phytase production. Permeabilization treatments using detergents, organic solvents, enzymes and physical methods were performed and compared by measuring the phytase activity of whole cells. None of the permeabilization methods except the freeze-thaw method enhanced phytase activity. The enzyme activity of a yeast suspension subjected to 15 cycles of freezing and thawing was 77·26 U g⁻¹ cells. Phytate in feeds is an anti-nutritional factor which complexes with many minerals, rendering it unavailable to monogastric animals. Rhodotorula gracilis subjected to freeze-thawing can be used as a source of phytase in feeds to enhance phosphorus availability.     

Wound healing studies of Aristolochia bracteolata Lam. with supportive action of antioxidant enzymes

Aristolochia bracteolata is a perennial herb, the leaves of which are used by the native tribals and villagers of the Chittoor District of Andhra Pradesh in India for the rapid healing of cuts and wounds. The ethanol extract of the shade-dried leaves of Aristolochia bracteolata Lam. was studied for its effect on wound healing in rats, using incision, excision and dead-space wound models, at two different dose levels of 400 and 800 mg/kg/body wt./day. The plant showed a definite, positive effect on wound healing, with a significant increase of the level of two powerful antioxidant enzymes, super oxide dismutase and catalase, in the granuloma tissue.     

Novel enrichment technique for the isolation of highly potent catalase producing yeasts from soil1

Among the 252 soil isolates screened, about 40% were catalase-positive. A novel soil enrichment culture technique consisting of feeding decreasing concentrations of a rich nutrient medium along with increasing concentrations of H2O2 (up to 15% v/v) in a semi- continuous glass column reactor over 15 days resulted in the isolation of high catalase producing yeasts identified as Saccharomyces cerevisiae and Schizosaccharomyces pombe. These yeasts produced 2–3 times more of intracellular catalase (1630 to 2277 U/ml) than the other microbial isolates (15 to 820 U/ml) tested. The other microorganisms gradually disappeared as the concentration of H2O2 increased in the enrichment. The technique could be used for the isolation of exclusively yeasts that might have superior industrial properties such as high ethanol, flavour, protein and lipid production.     

Expression of the cry1EC gene in castor (Ricinus communis L.) confers field resistance to tobacco caterpillar (Spodoptera litura Fabr) and castor semilooper (Achoea janata L.)

Castor (cv. DCS-9) has been transformed through Agrobacterium-mediated and particle gun bombardment methods using appropriate vectors containing the Bt chimeric gene cry1EC driven by enhanced 35S promoter. About 81 and 12 putative transformants were regenerated following selection on hygromycin and kanamycin, respectively. Southern analysis of DNA extracted from T₀ plants confirmed integration of the introduced gene in castor genome. The integration and inheritance of the introduced genes was demonstrated up to T₄ generation by PCR and Southern analysis. Southern analysis of two events having single and two copies showed the same pattern of integration in the subsequent generations. Insect feeding experiments conducted in the laboratory by releasing neonate larvae of castor semilooper and S. litura on leaf tissues excised from transgenic and control plants showed varying degrees of larval mortality and slow growth in larvae fed on transgenic leaf tissue. Field bioassays against Spodoptera litura and castor semilooper conducted for eight events in T₁–T₄ generations under net confinement were more informative and events conferring resistance to the two major defoliators were identified.     

Fatty acid changes during maturation of Momordica charantia and Trichosanthes Anguina Seeds

Changes in fatty acids were studied during maturation of Momordica charantia and Trichosanthes anguina seeds, which contain cis-9, trans-11, trans-13-octadecatrienoic acid (α-eleostearic) and cis-9, trans-11, cis-13-octadecatrienoic acid (punicic), respectively. The two seeds matured 30 and 35 days after flowering, respectively. Total lipids as well as α-eleostearic acid accumulated rapidly from 10 to 20 days in M. charantia. In T. anguina the active period of lipid synthesis was from 15 to 30 days but punicic acid continued to be synthesized until maturity. In both species, the disappearance of linolenic acid and the reduction in concentration of linoleic acid were concomitant with the formation of conjugated fatty acids. The conjugated fatty acids were absent from monoacylglycerols and phospholipids of both species, and also from the diacylglycerols of M. charantia, throughout maturation