Science Vision

197–203

Authors: C. Malsawmtluangi, B. Lalzamliana, Klaudi K. Vaiphei

Sundried and smoked vegetables constitute major parts of the Mizo cuisine. Heavy metals and pesticides can be present in vegetables and cause many diseases including cancer. The objective of this study is to determine the concentration of heavy metal and pesticide residues in commonly consumed sundried and smoked vegetables from Aizawl market. Since cancer is prevailing at a high rate in Mizoram, it also aims to study whether there is any link between cancer and these vegetables. The concentrations of heavy metals were analyzed using atomic absorption spectroscopy and pesticide residues levels were analyzed using gas chromatography. This study reveals that the levels of heavy metals tested were within the permissible limits in all the vegetable samples, except for cadmium. Since cadmium exceeds the permissible limit, it can pose health risk for the consumers. The pesticide residues found in the tested samples were all within permissible limits. However, the amount and duration of consumption need to be considered as this can be a predisposing factor for cancer and other diseases.

217-221

Authors: Lalhruaitluangi, C. Khawlhring

The present experiment was carried out to standardize suitable drying techniques for hybrid tea rose variety ‘Valencia”. Two types of desiccants viz., silica gel and boric acid were used as embedding materials for drying, and the flowers were dried in hot air oven with different temperature and time combinations such as 40°C for 24 hours and 48 hours, 45°C for 24 hours and 48 hours, 50°C for 24 hours and 48 hours, 55°C for 24 hours and 48 hours, 60°C for 24 hours and 48 hours. Different observations were taken such as fresh and dry weight of flowers and hence moisture loss percentage calculated, petal diameter before and after drying were taken and hence petal shrinkage was determined. Sensory evaluations such as flower colour, shape, texture and overall acceptability was also determined. Results show that maximum moisture loss percentage (86.44%) was obtained in flowers embedded with silica gel and dried at 60°C for 48 hours; largest difference between petal diameter of fresh and dry flowers, and also maximum petal shrinkage of 14.27% occurred in those embedded with silica gel and dried at 60°C for 48 hours, whereas best score in sensory evaluations in terms of flower colour, flower shape, flower texture and overall acceptability were obtained with rose flowers embedded in silica gel and drying at 50°C for 48 hours.

228-237

Authors: V. Ralte

Mining causes massive damage to landscape and biological components of an ecosystem. Due to extensive and unmanaged coal mining in the southern part of Nokrek Biosphere Reserve of Meghalaya, the area has been turned into degraded land since nutrient deficient sandy spoils are hostile for the growth and regeneration of plant communities. Soil is sandy to sandy loam and red, brown to dark brown in colour. The physico-chemical properties of the soil were greatly affected due to coal mining. There is an increased acidity i.e. from 6.00 in the undisturbed forest (control site) to 3.50 in the coal mine spoil since abandoned mine spoil discharge acidic water that are enriched with iron and other metals and metalloids. Apart from this, soil nutrients are greatly depleted. The core zone soils are rich in organic matter and nutrients whereas coalmine spoils show sign of degradation especially in the nutrient content.

250-259

Authors: K. Lalchhandama

Gram-negative bacteria belonging to the order Rickettsiales such as Anaplasma, Ehrlichia, Neorickettsia, Rickettsia, and Orientia are the causative agents of infectious diseases collectively known as rickettsioses. Of the different rickettsial diseases, spotted fever and scrub typhus have ravaged India for the past couple of centuries. Specifically called the Indian tick typhus, spotted fever was discovered in India in the latter half of the 19th century. After several decades of dormancy, the disease re-emerged in several parts of India. Scrub typhus, originally discovered in Japan, has been recognised to be endemic to a so-called Tsutsugamushi Triangle, extending from Russian Far East and Korea in the north to northern Australia in the south and Afghanistan in the west, but the geographical description has now been breached. Not only in India, scrub typhus has emerged as the leading infectious disease in all endemic areas. Almost all Indian states have records of recurrent outbreaks. Infection can be of dire consequences, as multi-organ dysfunction and neurological disorder (meningocephalitis) are the common complications. This article discusses the historical background and scientific reports of rickettsioses in India.

128-147

Authors: B. Bharali, P. Borgohain, D. Bezbaruah, V. Vanthangliana, P. Protim Phukan, R. Rakshit

Tertiary sediments are thickly deposited in most part of the northeast India attaining a maximum thickness of ±7 km sedimentary succession. Surma basin located in the eastern proximity of India is also characterized by a thick sedimentary column which can be considered as the northeastern extension of Greater Bengal basin. This basin was initiated due to the mutual collision between Indian and Burmese Plate. Due to this collision, the bed rocks have undergone folding which are oriented N-S trending hill ranges. The basin was also cut by a number of parallel to sub-parallel transverse faults and thrusts. The litho association is consisting of sandstone, siltstone, shale and their various proportions. The present study focused on the provenance of the sediments, tectonic settings of the basin and various paleoclimatic conditions prevailing during the time of deposition by using petrography, granulometric and heavy mineral analysis of representative rock samples which were collected from various parts of Aizawl district of Mizoram belonging to the Upper Bhuban Formation. Based on the various proxies it was confirmed that the sediments were primarily derived from surrounding orogens and deposited in a shallow marine basin under the influence of fluvial-deltaic conditions which were basically sourced from felsic provenance. The sediments were moderately weathered under semi-humid to humid climatic condition before they deposited into Surma basin. Sandstones samples are litharenite and wacke type which were deposited in an active continental margin to recycled orogen settings.

160-162

Authors: D.C. Vanlalfakawma, F. Lalnunmawia, S.K. Sen, S.K. Tripathi

Bambusa tulda Roxb. is a semi-deciduous caespitose bamboo endemic to Indo-Burma. It is known as ‘rawṭhing’ in Mizoram, India, and its mass gregarious flowering is called ṭhingtâm. ‘Ṭhingtâm’ has a cycle of about 45-50 years. The first ṭhingtâm, recorded in the region was in 1880, which was preceded by mautâm (gregarious flowering of Melocanna baccifera) in 1862; i.e., the ṭhingtâm phenomenon occurred ~20 years after the Mautâm. The last ṭhingtâm was recorded in 1981. However, there has been a localised ṭhingtâm at Zawlnuam, a village at the northwestern Mizoram. The first flowering was recorded in 2015. This unusual phenomenon needs to be investigated.

172–181

Authors: H. Lalrinawmi, J.M.C. Vabeikhokhei, J. Zothanzama, Zohmangaiha

Twenty-seven (27) species of edible mushrooms growing in both soil and wood have been described here from Mizoram, India. All the species were identified based on their morphological, both macro- and microscopic characteristics. The study was carried out during July 2013 to October 2016. Wood inhabiting fungi viz. Schizophyllum commune (pasi), Lentinula lateritia (pa pal), Auricularia auricular-judae (Pu Vana beng), Lentinus tigrinus (pa hnahkhar), L. polychrous (pa chang/pa puanveng) and soil growing fungi viz., Lactifluus corrugis (pa uithin), Lactarius piperatus (pa lengvar), Macrolepiota dolichaula (pa se-ek), Russula subfragiliformis (pa lengsen), Termotomyces heimii (pa sawntlung), Volvariella taylorii (changel pa) are the edible species known to the local community. Other edible species yet unknown to the local community in Mizoram are also recorded viz., Cantharellus cibarius, Craterellus cornucopioides, Lycoperdon perlatum, Macrolepiota procera, Ramariopsis kunzei, Russula aurora, R. compacta, R. cyanoxantha, Lentinula edodes, Lentinus sajor-caju, Pleurotus ostreatus, P. djamor, Tremella fuciformis, T. mesenterica, Laetiporus suphureus and Fistulina hepatica.

61-68

Authors: L. Pautu, Zorammuana, P. Lalmalsawma, Zoramthara

Outbreaks of dengue disease have been reported from many parts of India including northeastern States. There were reports of dengue disease outbreaks from Moreh town in Manipur during 2007-2008 and from Pasighat in Arunachal Pradesh during 2012 from northeast India. The first outbreak of dengue-like fever in Mizoram was reported on 30th August from Tuikual North ‘C’ Mual, Aizawl, followed by consecutive outbreaks at 10 localities between August and December 2016 within Aizawl city. In these localities, epidemiological and entomological studies were conducted to identify the disease and its vector. Blood serums were collected from the patients for the serological confirmation and Aedes mosquitoes (adults and larvae) were collected for vector identification and confirmation. There were 580 (NS1=384, IgM=196) patients confirmed with the disease from 11 localities in Aizawl and Ae. aegypti were identified as a potential vector species. There was no predilection towards sexes and all age group are affected with a median age 30. Parameters of entomological study revealed high density of vector mosquito in the study areas. Public health actions pertaining to the prevention and control of the disease were implemented. As dengue is included among the notifiable diseases in India, government authorities should strengthen manpower, case management and laboratory support, and regularly organizing interactive co-ordination meetings at all levels to sensitize public through IEC and awareness programmes as well as source reduction of Aedes mosquito breeding.

94-103

Authors: K. Lalchhandama

Three flukes, Schistosoma haematobium (urinary blood fluke), Clonorchis sinensis (Chinese liver fluke), and Opisthorchis viverrini (Southeast Asian liver fluke) are, by official decree, Group 1 (fully proven) human carcinogens. Thus, they comprise a group of preventable carcinogens. But considering the situation of prevailing infection, from the lifestyle and food habits of people in the endemic regions, it is unlikely that they are eradicated in the near future. S. haematobium is transmitted by snails and infection is acquired from snail-infested water. C. sinensis and O. viverrini are both transmitted from eating fish. As medically important flukes, it is crucial to understand their biology, and this is an attempt to explain that in the light of the history of their discovery. Further, this is written with a hope that several facts, often erroneously presented in scientific literature, about these flukes are rectified.

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.