Science Vision

8-14

Authors: B. N. Mahanta, R. K. Sarmah, T. K. Goswami, B. R. Syngai

A thin linear belt of Permian Lower Gondwana rocks occur in the Eastern Himalayas from Arunachal Pradesh to Sikkim. The Lower Gondwana Group of rocks consists of shale, siltstone, sandstone, carbonaceous shale and coaly matter and is sandwiched between Miri Group and Siwalik Group of rocks. Heavy mineral composition of sandstones is extensively used in the provenance studies as they are the surviving remnants of the rather abundant but unstable mafic components of the source rock. The sandstones of Lower Gondwana Group bear the heavy mineral assemblage of chlorite, biotite, zircon, ilmenite, epidote, garnet, amphibole, chloritoid, brown tourmaline, magnetite, staurolite, rutile, and opaques which is indicative of a provenance of metamorphic rocks with input of igneous rocks. Provenance sensitive mineral index ratios were also calculated to see the variation in the ratio of two or more stable minerals with the same characteristics.

19-24

Authors: B. Lalruatfela, J. Zoremsiami, G. C. Jagetia

The use of tobacco and its products are known to cause many illnesses including cancer. A smokeless tobacco locally manufactured called tuibur (tobacco brew) has been consumed by the Mizos from a very long time. In this experiment we aim to determine the cytotoxicity of tuibur by an in vitro study on tuibur-treated human peripheral blood lymphocytes. We have found that 24 h treatment of human lymphocytes with two grades of commercial tuibur and nicotine showed a concentration dependent decrease in cell viability. We, therefore, concluded that as the in vitro use of tuibur has an adverse effect on cell survival, its consumption might have potential side effects on the health of the users.

33-52

Authors: K. Lalchhandama

Cancer is a disease of antiquity. The Ancient Greeks were familiar with onkos (from which we have the term oncology)—tumour of all sorts. Hippocrates coined karkinos and karkinoma, our source of the words cancer and carcinoma. Of a plethora of carcinogens, parasitic worms (helminths) constitute a considerable health concern. Three trematodes, Clonorchis sinensis, Opisthorchis viverrini, and Schistosoma haematobium are now officially classified carcinogens. But the discovery of helminths as cancer-causing agents took wrong turns and marks an inglorious chapter in the history of science. The carcinogenicity of worms, vindicating Rudolf Virchow’s reiztheorie (irritation theory) of cancer origin, was glorified in the scientific forefront by Johannes Fibiger in the 1910s. Discovery of a new nematode, which he proudly named Spiroptera carcinoma, and his subsequent demonstration that the parasite could induce stomach cancer in rats, earned Fibiger a retrospective Nobel Prize in Physiology or Medicine in 1926, and a lasting fame. But not in an appealing way. His achievement did not withstand the test of time. S. carcinoma was annulled as an invalid taxon in zoology—supplanted by Gongylonema neoplasticum—and eventually was branded as a non-carcinogenic agent.