Science Vision

112-117

Authors: S. Rai and A.L. Fanai

The spectroscopic properties of Ho3+ in SiO2-TiO2 were investigated using optical absorption and fluorescence studies. The intensities of the electric dipole transitions of Ho3+ in the SiO2-TiO2 doped glasses were calculated from the absorption spectra in the visible region. From the experimental values of the oscillator strengths and calculated matrix elements, the Judd-Ofelt intensity parameters were calculated by least square analysis. The fluorescence spectral distribution of Ho3+ has been recorded using 370nm excitation source. The emission bands observed near blue and green regions were assigned as 5G5, 5G6→5I8, 5F3→5I8 and 5F4, 5S2 →5I8 radiative transitions.

122-127

Authors: H. Lalruatsanga

In P. wallichii, the flowers are cleistogamous, enclosed by a thin membranous spathe. The two anthers are borne on a forked filament placed adjoining to the stigmatic lobes. Ontogenetically the two anthers developed separately; because of intercalary growth, it becomes bifid. The archesporial cell comprises of uniseriate rows of cells, the anther wall consists of a very thin epidermis, unilayered endothecium with fibrous thickenings and the tapetum with uni- and binucleate cells. The anther wall development is reduced type, middle layers are absent. The connective tissues also acquire fibrous thickenings. Cytokinesis of microspore mother cell is successive type within a distinct callose wall. Pollen grains are dispersed in dyads with minute and dense granular exine.

133-142

Authors: R.K. Pandey

This article discusses the biology and physics of electrical system of living body that controls all body functions. Electrochemical potentials in the nerve cells are the source of billions of electrical signals, which propagate from all parts of body to the brain via neurotransmitters in the living body whose measurements allow obtaining useful clinical information. The propagation of electrical pulses in the living body is like transmission of pulses in a cable. The living cell membrane offers resistance and capacitance that form a complex net of electrical circuit. The ratio of space constant between cells to the time constant of neural resistance and capacitance define the speed of nerve impulses from one cell to other cell.

145-151

Authors: V. Ralte

Phytochemical screening was performed on leaves and flower extracts of Ipomoea cairica obtained from Aizawl, Mizoram. To analyse the bioactive compounds, Pet. ether, CHCl3 and CH3OH extracts of the selected plants were tested by following standard procedures. The results demonstrated the presence of alkaloids, sterols, flavonoids, reducing sugars, tannins, saponins, terpenoids, anthraquinones, glycosides and phenols. These results were compared with literature values. Indications from the results depicted usefulness of the plant parts in the treatment of some common diseases.

158-168

Authors: J. Lalnunmawia and J. Lalhlimpuii

Mizoram predominantly comprises of Surma Group of rocks which also cover the whole area of the Aizawl city. Sandstones exposed along Durtlang road section in the northern part of the Aizawl city are composed mainly of quartz, mica group of minerals like biotite and muscovite, lithic fragments and feldspar group of minerals like plagioclases, microcline and orthoclase, and other minor detrital components. The classification and provenance studies of sandstones are basically done on the basis of three important major detrital minerals like quartz, feldspar and lithic fragments. On the basis of these three components, the sandstones exposed along Durtlang road section were classified into litharenite and sublitharenite. The sources of the sediments were determined to be of igneous and metamorphic terrains, probably of Himalayan orogen and the Indo-Burmese collision zones.

61-66

Authors: J. Hussain and Lalthlamuana

This paper examines and compares different types of artificial neural networks for recognition of Mizo script. The Mizo script and English script are very similar in nature but special characters – Â, â, Ê, ê, Î, î, Ô, ô, Û, û, Ṭ, and ṭ – are incorporated in Mizo scripts which are not available in English script. In this experiment, an attempt was made to recognize Mizo script including capital letter, small letter, numerals, and special characters. The approach involves processing input images, conversion of image characters into binary matrix, analyzing and mapping the binary matrix, training and testing with a set of desired Mizo characters using different types of neural networks such as back propagation algorithm, radial basis function, learning vector quantization, and recurrent neural network. The results are compared with each other and suggest the best artificial neural networks algorithm for use in the recognition of Mizo script.

74-83

Authors: K. Lalduhawma and Shiva Kumar

The area in and around Aizawl City is dominated by Middle and Upper Bhuban rock formations. Geologically and petrologically the area has not been so far explored therefore the present study was initiated. The study area is composed of sandstone and shale belonging to Middle and Upper Bhuban formation and lies in between 92°60’ E longitude and 23°58’ N latitude. Rock samples collected from different sections in the study area were analyzed to study the mineralogical compositions of the rocks and determination of the multi-elemental distribution using high precision X- ray fluorescence analysis. The study shows that the area is dominated by different rock units such as sandstone, shale, siltstone and shaly sandstones belonging to middle and upper Bhuban formation. Petrological studies reveal that sandstone is greywacke exhibiting argillaceous matrix mainly siliceous, ferruginous and calcareous (due to presence of fossils) and rock fragments. The oxide and silica weight percentage observed from the geochemical analysis indicate Na2O, K2O and MgO have the maximum variation in the study area. The trace elements Sc, Co, Ni, Cu, Zn, Ga, Pb, Th, Rb, U, Sr, Y, Zr, Nb, Ba, Cr, V in parts per million (ppm) show a different variation in sandstone, shale and siltstone. Ba is having maximum value >500 ppm followed by Zr in sandstone whereas Cr is maximum in shale. Prominent feature is a persistently higher amount of uranium (~4 ppm) in the rocks of Middle Bhuban rocks in contrast to the average abundance in sandstone i.e. 2 ppm.

89-93

Authors: Aldrin Malsawmtluanga, Lalnunpuia, Lawrence Z. Chhangte, Ricky L. Ralte and Z. Pachuau

A theoretical study of electronic and optical properties of zinc blende structure of BeS is presented by applying the full-potential linearized augmented plane wave (FP-LAPW) method within density-functional theory (DFT) as implemented in WIEN2k code. Our results are in agreement with previous theoretical and experimental studies on this important semiconductor compound. For the optical calculations, the dipole approximation is used. The imaginary part of dielectric function is calculated in momentum representation, which requires matrix elements of the momentum p between occupied and unoccupied states. The microscopic origin of the main features in the optical spectra is identified and also the factors responsible for most of the optical absorption.

2-17

Authors: K. Lalchhandama

The history of medicine teaches us that understanding the principle and natural origin of diseases is key to their effective management. Ancient Greek and Roman physicians abandoned supernatural interventions, as previously believed to be the sources of diseases, and instead expounded a theory of natural cause called miasma. Malaria (the very word meaning ‘bad air’) is the archetype, and is the most vicious of them all, then and thereafter, in the entire history of humankind. The search for its origin and transmission was as old as the miasma theory itself. Some rays of light dawned during the Italian the Renaissance from Girolamo Fracastoro in the form of contagion theory, but its true nature was as enigmatic as ever. The Pandora’s box of dilemmas was closed only on the closing of the 19th century CE. Yielding no medical enlightenment after a good two millennia, the miasma theory was confronted by the fledgling germ theory, and finally subjugated by the mosquito-malaria theory. The epoch-making discoveries came from two army physicians, Alphonse Laveran in Africa, who discovered the malarial parasite, and Ronald Ross in India, who discovered the mode of transmission. The saga is classic in the annals of science where theories are tested and falsified, and the one with the most credible and durable evidence survives, in spite of the odds and authoritative hostilities.

28-33

Authors: D.C. Baro, S. Sharma and R.A. Baishya

Extensive survey for ornamental fishes of Sonkosh River was conducted from April, 2012 to March, 2013. The River Sonkosh is located in the western part of Kokrajhar District of Bodoland Territorial Council (BTC) area, a tributary of the Brahmaputra River in north-west bank. During the survey period, a total of 49 ornamental fish species were identified belonging to 34 genera, 18 families and 6 orders. Cyprinidae family represented the maximum number of species (18) followed by the family Channidae (5), Cobitidae (4), Siluridae (3), Amblycipitidae (3), Balitoridae, Nandidae, Badidae and Belontiidae (2 species each) and Notopteridae, Schilbeidae, Olyridae, Chacidae, Mastacembelidae, Chandidae, Osphronemidae, Gobiidae and Tetraodontidae (1 species each). The study shows that 1 species belongs to endangered category, 3 species near threatened, 1 species vulnerable, 32 species least concern, 3 species data deficient and 6 species not evaluated according to IUCN status, 2013.

39-45

Authors: Lalmuansangi and H. Lalramnghinglova

The present study was conducted during March to September 2013 at Palak Dil, the largest lake in Mizoram, which is located between 92°52’-92°55’E longitude and 22°10’-22°13’N latitude in the remote part of Mara Autonomous District Council in the southern part of Mizoram near the border of Indo-Burma hotspots region. The Palak Dil is a nationally recognized natural lake and the catchment area is approximately 18.5 sq km and the total water body is around 1.5 sq km only. The water quality, viz. temperature, pH, total dissolved solids, electrical conductivity, acidity, alkalinity, dissolved oxygen, biological oxygen demand, carbon dioxide, total hardness, chloride, nitrate, phosphate and iron were analyzed and found that all the parameters are within the standard limits given by various scientific agencies, but the water is not pure as expected. This can be accrued to the developmental works that were undergoing around the lake. Study on biodiversity was carried out by field enumeration, collection and identification of the flora and fauna. It was observed that the ecosystem in which birds and animals living there is gradually degrading due to anthropogenic activity and developmental works.

51-58

Authors: S. Mukherjee and N. Senthil Kumar

The terminator technology is a genetically engineered suicide mechanism that can be triggered off by specific external stimuli. The preferred trigger is antibiotic tetracycline, which is applied to seeds. As a result of which the seeds of the next generation will self-destruct by auto-poisoning. The main version of the terminator includes a set of three novel genes inserted into one plant. However, there is another version, which divides two or three genes on to two plants that are later to be cross-pollinated. The ultimate outcome is a dead seed in the following generation. Many consider terminator technology a problem due to the fact that the top 10 largest seed companies globally control half the world’s commercial seed market. Therefore, if terminator technology is commercialized, corporations will most likely try to incorporate this technology into all of their seeds. This would secure a much stronger monopoly on the seed market compared to patents because this technology would ensure that it is impossible for farmers to re-use their once harvested seeds.

149-156

Authors: S. Lallianrawna, R. Muthukumaran, V. Ralte, G. Gurusubramanian, N. Senthil Kumar

Petroleum ether, chloroform and methanol extracts of Ageratina adenophora leaves were screened for assessing bioactive phytochemical constituents. The preliminary phytochemical screening using the standard phytochemical tests detected the presence of alkaloids, steroids, flavonoids, reducing sugars, tannins, saponins, terpenoids, anthraquinones, cardiac glycosides and phenols in different solvent extracts. Total phenolic and flavonoid contents along with total antioxidant capacity of the polar methanolic extract of A. adenophora leaves were evaluated to explore the reliable and potential sources of novel natural antioxidants. The methanol extract leaves revealed a total phenolic content of 30.0 mg gallic acid equivalent/g and 510.0 mg quercetin equivalent/g. The total antioxidant capacity ranges from 16.98 to 94.87% of standard ascorbic acid at concentrations ranging from 0.05 to 1 mg/ml of the plant extract in methanol.

162-168

Authors: S. Ansari and A. Shayestehfar

In the present study inter- and intra-population species of Lepadella patella were investigated. For this purpose 110 individual of geographical populations of these rotifers were collected from different parts of Arak county, and for each habitat five ecological factors such as longitude, latitude, elevation, temperature and pH were examined. The ANOVA test and also one-sample t-test showed significant difference for morphological characters. In inter- and intra-population section, 10 individual were selected randomly from each populations, then seven quantitative morphological characters were examined, the individuals were separated from other in the PCA plot and UPGMA tree. Significant correlations negative/positive were found between some of morphological characters with studied ecological factors of habitat, in addition variations in morphological characters were seen between population and they were separated in PCA plot and also UPGMA tree. Ecological factors were different between habitat, therefore in this study, we concluded that variation temperature was most effective among all the ecological factors, on diversification of populations.

175-179

Authors: Lalrokima Chenkual

In Mizoram, there is a practice of an alternative system of propagation of messages called torchlight Morse code communication. It is an indigenous technology, by improvising the existing W/T based on Morse code communication into Mizo language. Morse code encodes the Roman alphabet, the Arabic numerals and a small set of punctuation and procedural signals as standardized sequences of short and long "dots" and "dashes", or "dits" and "dahs". In the Mizo method, hand-held portable torchlight was used to transmit Morse code by light signal and the receiver could easily interpret the message using the same code. This mode of communication augured well in the folded belt of Mizoram trending in N-S direction and most of the villages/town exists on the top of the hillocks. Most of the village built signal tower in the elevated places and any person who was well versed in the system was on duty by rotation to received, reply and forwarded the message. This practice, which was banned and became dormant when Mizoram was declared as a Disturbed Area according to Armed Forces (Assam & Manipur) Acts, 1958 in 1966, is now revived by Disaster Management Centre, Administrative Training Institute, Mizoram in collaboration with Mizo Signal Corps by training NGOs and Mizoram Police Radio Organization personnel. With its advantages and limitations, it may also be applicable in other part of India, especially in other hilly, vulnerable and inaccessible area.

186-190

Authors: H. Lalrinpuii and Lalnuntluanga

Deterioration of air quality, which is an alteration of atmospheric chemistry by pollutants from natural and anthropogenic sources is of major global environmental concerns today. The sources of deterioration of air quality in Mizoram is mainly due to shifting cultivation or slash and burn agriculture or jhum burning, one of the main form of agriculture and livelihood of the villagers. Large amounts of air pollutants are emitted during prescribed forest fires (jhum burning). Unlike wildfires, prescribed fires are intentionally ignited in order to maintain ecosystem health and minimize adverse impacts of long-term fire suppression while protecting property. However, jhum burning has resulted in many forms of pollution, directly and indirectly hampering the natural environment .The need to understand the effect of jhum burning and the consequences not only on soil, but on air and human health is important.

200-211

Authors: Laldinpuia

Saiha town slumping area was triggered by cloud burst on the 16th and 17th May, 1995. Prominent transverse cracks were observed from the month of October, 2010 at the rupture surface of subsidence localities such as New Colony-I, New Colony-III, College Veng and Council Veng, Saiha. About 310 houses were affected. This could be due to high rate of percolation of rain water which developed pore pressure and weakening connection between the top and bottom layer, thus, reduced shear strength or resisting force. A continuous movement was observed till 2013, and maybe unsafe localities if not mitigate at the correct time. The present paper deals with geological field investigations as well as recommendation in terms of preventive and remedial measures.