Science Vision

63-78

Authors: Lalrinkimi, R.K. Lallianthanga

This study provides a first report of the various tree species prevailing in the tropical semi-evergreen forest within Mizoram Science Centre, Berawtlang, Aizawl in relation to their diversity; and also mentions traditional ethnomedicinal and economic uses of the species. A total number of 776 individual trees were assessed within the study site belonging to 74 different species representing 61 genera and 34 families. Among these, 55 tree species have been reported by previous workers to possess indigenous medicinal values. The most abundant tree species at the study site was found to be Callicarpa arborea (hnahkiah) of Verbenaceae comprising 14.30% of the total trees assessed, followed by Anogeissus acuminata (zairum) of Combretaceae with 12.62%, and Schima wallichii (khiang) of Theaceae with 10.56%. A concise list of the species recorded along with their ethnomedicinal and economic uses have been presented here. The prospect of in situ conservation of tree species is briefly highlighted.

80-99

Authors: Laldinpuia

Ramhlun Sports Complex is situated at the eastern limb of Aizawl anticline, Mizoram. Landslide took place in August 2012 which badly affected 16 houses. Due to presence of tension cracks, 38 houses are vacated within a safe time, but dismantled and 10 buildings are collapsed in August 2013. This affected 195 persons of 41 families. A geological investigation was performed; representative soil samples are analyzed as Atterberg’s limits, CBR (California bearing ratio), OMC (optimum moisture content) and MDD (maximum dry density), respectively. Instrumentations and monitoring of the movement using crackmeter and tape extensometer also done for two years. The CBR and MDD values are too low as compared to the safety standards, while moisture content is too high. This may show that the movement and erosion rate may be high. The movement was relatively high when rainfall increases. It was observed that, the area is not suitable and unsafe for settlement; constructions of road/ pavement are not recommended.

24-29

Authors: Lalnunthari, John Zothanzama, Saizamrengi

Melocanna baccifera is a well-known native bamboo species of India belonging to the grass family Poaceae. A study on the presence of arbuscular mycorrhizal fungi (AMF) association with M. baccifera was conducted from a disturbed and undisturbed bamboo forest sites within Mizoram University, Mizoram, India. Soil from the rhizosphere region as well as physico-chemical properties of the soil were taken to study AMF diversity. The roots were observed for percentage colonization by AMF. It was found that undisturbed site had higher colonization percentage (56%) than the disturbed site (46%). The Shannon’s diversity index showed that undisturbed site (1.46) had more diversity than the disturbed site (1.59) while disturbed site showed lower index of dominance (3.34) which indicates higher shared dominance of AMF species than undisturbed site (4.66).

35-42

Authors: K. Thanzami, C. Lalremruati, Vanlalthlana, Andrew Lalthasanga, Phyobemo C. Tungoe, Joseph L. Ralte, H. Lalhlenmawia

Effect of controlled and uncontrolled fermentation temperature on the microbial load, biochemical changes and change in nutritive value of bekang-um was studied in an attempt to upgrade the traditional fermentation technology of soybean, Glycine max (L.) Merr. The sterile cooked beans were fermented using a low-cost wooden incubator developed previously, adjusted at a constant temperature (35°C) and also under direct sunlight for 4 days following the traditional method. The microbial load, biochemical changes and changes in nutritive values of both the beans fermented were compared under controlled and uncontrolled temperature. The result showed that the viable cell counts, pH, free amino acids, proteolytic activity and alpha amylase activity increased in both the fermenting conditions throughout the process while the reducing sugar increased in the first day and decreased gradually with fermentation in both conditions. There is also an increase in moisture, protein and calorific value, and a decrease in carbohydrate, fats and ash value in both conditions. Fermentation under controlled temperature gave the higher levels of alpha amylase and proteolytic activities, viable cell counts, pH, free amino acids and nutritive value. These results suggested that fermentation proceeds at higher rate under controlled temperature using low-cost incubator could be utilized for the commercial production of bekang-um as the fermentation time could be reduced from three days to two days in addition to its simpler technology.

51-58

Authors: R. Lianngenga, L. Thangmawia

The effect of mechanical relaxation time in the elastic wave propagation in elastic materials with voids is investigated. The phase speed and the attenuation coefficients are obtained and observed the effect of mechanical relaxation time. The phenomenon of reflection of elastic waves due to the incident waves from a plane boundary of elastic materials with voids is studied. The amplitude and energy ratios of the reflected waves are obtained. Numerically these ratios, phase speeds and the corresponding attenuation coefficients are computed for a particular model and the effect of mechanical relaxation time is discussed.

1-5

Authors: H. Lalramnghinglova, Anil Pratap Singh, P.C. Lalrintluanga

Education is a process of development which includes three major activities, namely teaching, training and instruction. Environmental education is a process to promote the awareness and understanding of the environment, its relationship with man and his activities. It is also aimed at developing responsible actions necessary for preservation, conservation and improvement of the environment and its components. It has been introduced as a regular course in formal school education system in India following the directive of the Supreme Court of India. The present study aims at critically analyzing curriculum of environmental studies at primary, secondary and senior secondary level. The detailed analysis was done on the basis interactions with important stakeholders. In our study, we found that there is scarcity of qualified teachers to teach Environmental studies at each level. During interactions it was found that teachers have several environmental knowledge gaps and misconceptions about important environmental issues like about acid rain, ozone layer depletion and greenhouse effect. Our survey indicates that teachers hardly practice innovative methods to teach environment education. Most commonly used method is lecture. Field visits, practical, study tour and demonstrations are missing in many schools. It was also found that course content is not incremental; there is very often repetition of the topics. At college level, there is a need to focus more on environmental education and upgrade the course components. There should be both pre-service and in-service training for teachers to infuse emerging issues in course content. Such training should equip teachers for collecting and using relevant teaching materials to impart emerging issues. A few suggestions and recommendations are given based on critical analysis.

12-15

Authors: David C. Vanlalfakawma, Sukanta Kumar Sen, S.K. Tripathi, F. Lalnunmawia

Tobacco is an important agricultural product that is consumed all over the world. More than 8000 chemicals are reported to be present in tobacco, and a large number of these chemicals are known carcinogens, and hence is known to be one of the most significant contributors to the development of cancer of different body parts. These chemicals have been reported to alter both the genetic and epigenetic constituents of cells. Such changes involve point mutation, deletion, insertion, recombination, transversion, transition, and chromosomal aberrations including aneuploidy and polyploidy. The chemical composition of different types of tobacco has been reported to be different. In this article, brief information about tobacco plants; history, types and popularity of tobacco; its chemical composition; relation to cancer and other diseases and its effects on the molecular, epigenetic and genetic compositions have been highlighted.

104-110

Authors: C. Lalremruati, C. Malsawmtluangi, H. Lalhlenmawia

The objective of this study was to determine the phytoconstituents present in successive extracts and the antidepressant activity of methanolic extract of the spadix of Colocasia affinis. The preliminary phytochemical investigation indicated the presence of fats and fixed oils, steroids and triterpenoids in petroleum ether extract, steroids and triterpenoids in chloroform extract, flavonoids and tannins in methanol extract and carbohydrates in the aqueous extract. An in vivo test for antidepressant activity was performed on the methanolic extract of the plant at two different doses using force swim test and tail suspension test on an experimental animal model (rat). Imipramine was used as a standard drug for the study. The methanolic extract at 200 and 400 mg/kg, produced significant reduction (p<0.001) in the immobility period when compared with that of control group animals in both the tests. Thus, the result indicates that the methanolic extract exhibited significantly good antidepressant activity. Further investigation may be needed to understand the actual mechanism of action.

120-124

Authors: P.B. Lalthanpuii, Zarzokimi, K. Lalchhandama

Cogon grass, Imperata cylindrica (L.) Räuschel, was studied for its flavonoid and phenol contents. A series of extracts of the underground (rhizome-root) parts was prepared by hot extraction using solvents of different polarities such as chloroform, methanol, and petroleum ether. The total flavonoid content of the plant extracts was determined based on the reaction with aluminum chloride, sodium nitrite, and sodium hydroxide. Quercetin was used as a standard reference. Chloroform extract showed highest content of flavonoids with 30.88 mg QE/g dry wt., followed by petroleum ether extract which was 22.05 mg mg QE/g dry wt., and methanol extract has the least value with 7.35 mg QE/g dry wt. The total phenolic content of the plant was estimated based on the reaction of Folin-Ciocalteu reagent using gallic acid as the standard reference. Again, the chloroform extract had the highest content with 7.54 mg GAE/g dry wt., while methanol extract contained 5.03 mg GAE/g dry wt., and petroleum ether extract contained 3.63 mg mg GAE/g dry wt. Our study shows that I. cylindrica is a good source of antioxidants.

81-91

Authors: C. Lalhriatpuia

Nanopillars-TiO2 thin films was obtained on a borosilicate glass substrate with (S1) and without (S2) polyethylene glycol as template. The photocatalytic behaviour of S1 and S2 thin films was assessed inthe degradation of methylene blue (MB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the SEM, XRD, FTIR and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data confirmed that the TiO2 particles are in its anatase mineral phase. The SEM and AFM images indicated the catalyst is composed with nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of MB was well studied at wide range of physico-chemical parameters. The effect of solution pH (pH 4.0 to 10.0) and MB initial concentration (1.0 to 10.0 mg/L) was extensively studied and the effect of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of MB was demonstrated. The maximum percent removal of MB was observed at pH 8.0 beyond which it started decreasing and a low initial concentration of the pollutant highly favoured the photocatalytic degradation using thin films and the presence of several interfering ions diminished the photocatalytic activity of thin films to some extent. The overall photocatalytic activity was in the order: S2 > S1 > UV. The photocatalytic degradation of MB was followed the pseudo-first-order rate kinetics. The mineralization of MB was studied with total organic carbon measurement using the TOC (total organic carbon) analysis.

98-103

Authors: P.B. Lalthanpuii, Zarzokimi, K. Lalchhandama

Cogon grass Imperata cylindrica is a perennial grass belonging to the family Poaceae, and the rhizome-root portion of which is used for the treatment of bacterial infections, ringworms and other skin infections. Among the Mizo people they are directly consumed or juiced for the treatment of intestinal infection. Its chemical and biological properties are poorly documented. In this study, a methanol extract of the rhizome-root was prepared by hot extraction in a Soxhlet apparatus. Standard chemical tests were conducted. The presence of alkaloids, carbohydrates including reducing sugars, phytosterols, tannins, saponins and proteins were confirmed as the major bio-compounds. Free radical-scavenging activities were also determined. The plant extract indicated concentration-dependent scavenging activity on DPPH with an inhibitory concentration (IC50) of 2.14 µg/ml. H2O2 was similarly scavenged, in which the IC50 was 2.221 µg/ml. Our results suggest that I. cylindrica has important medicinal values.