Science Vision

1-9

Authors: J. Lalnunmawia, Ch. Vabeihmo, H. Lalremruatsanga

Mizoram is entirely covered by sedimentary successions of variable sand-silt-shale ratio. The predominating bed comprises of Surma Group of rocks, and Bhuban Formation being the dominating strata. The present study area of eastern anticlinal limbs of the Aizawl city are made up of thick succession of Bhuban Formation of Surma Group dipping towards east with strike of approximately N-S direction. The present research aims to find out the nature of provenance and the environment of deposition of the sediments on the bases of petrography of the sandstones and heavy minerals present. The petrography indicate presence of quartz, lithic fragments, feldspar, micas, opaque minerals bind together by siliceous, ferruginous and carbonate cements. The heavy minerals comprises of garnet, augite, zircon, rutile, staurolite, sillimanite, kyanite, hypersthene, hornblende, chlorite, tourmaline and apatite. It is found that the sediments of sandstones are derived most probably from the Himalayan Orogenic fold belt and the Indo-Burmese Collision Zones, and the sediments being transported by turbidity current and deposited in deltaic to shallow marine environment.

16-20

Authors: L. Vanchhawng, P.C. Rohmingliana, R. Mishra, B.K. Sahoo, B. Zoliana

Radon gas is found in the environment, indoor and outdoor and its parent element being traced back to U238. Study of indoor radon inhalation dose have been carried out in Aizawl City, Mizoram, India in 24 dwellings, which were specifically selected according to the site location of the dwellings. Solid-state nuclear track detectors (SSNTD) have been used to obtain the time integrated concentration levels of indoor radon. DRPS (direct radon progeny sensor), which selectively register the tracks due to alpha emissions from 214Po from the deposited atoms of 222Rn progeny species is used for estimating the equilibrium equivalent radon concentration (EERC). The equilibrium factor (F-factor) for radon is then calculated using the measured EERC and concentrations of radon. The equilibrium factor may be defined as ratio of the amount of progeny nucleus to that of a parent nucleus. Inhalation dose has been obtained from the measured F-factor and concentrations of indoor radon. The data obtained in the present work has been analyzed to obtain the significant inhalation dose of indoor radon. From these observations it has been found that the annual inhalation dose of indoor radon in the study area is 624.89 mSv/y, which is low in comparison to the global average.

27-36

Authors: K. Lalchhandama

Ethidium bromide is a household name in biology, and is arguably the most popular stain in molecular research. It was discovered as a consequence of the growth spurt in chemical synthesis towards the very end of 19th century and in the first half of the 20th century. The precursor compound phenanthridine aroused its potential as a drug, basically because of its quinoline ring, which is interestingly the basis of the medicinal properties of important drugs, such as quinine, known at the time. A medical breakthrough was made in 1938 when some derivatives of phenanthridine were experimented to effectively kill Trypanosoma congolense and T. vivax, the protozoan parasites causing trypanosomiasis (sleeping sickness) in cattle. In 1946, the most effective compound was identified, and with slight chemical modification, it was mass produced as a trypanocidal drug, dimidium bromide, or trypadine. It was the principal veterinary drug in Africa until another chemical modification in 1952 yielded a more potent and less toxic compound, the now-famed ethidium bromide. Manufactured by Boots Pure Drug Co., Ltd. as homidium (Ethidium®), it served as the drug of choice in cattle trypanosomiasis for three decades. Its pharmacological property lies on its ability to intercalate between base pairs in the nucleic acids. It was a serendipitous moment when Piet Borst and Cees Aaij, dismayed at their broken ultracentrifuge, began to use the compound for staining DNA in gel electrophoresis. And the rest, as they say, is history.