Volume 14, Issue 3, 2014 July-September

Volume 14, No 3 Pages:
2014 July-September Articles: 9

Spectroscopic studies of Ho3+ doped SiO2-TiO2 nanoparticle for photonic applications

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.

ELIZ - Instant messenger for Android platform

ELIZ is an instant messenger for android platform mobile. This mobile application is developed for sending and receiving text messages from one mobile to another mobile having the android platform. The application will enable sending/receiving text message services from one client to the other via Google Cloud Server. This application is a simple and easy text messenger with freely available resources and hence messaging do not cost anything. Unlike other available application it will not use the phone number as ID for registering the app account, instead it uses the Gmail ID and password as its login ID for registering to the app account. This paper explains the development phases of the instant messenger and its scopes. ELIZ- the developed instant messenger is named after the first author.

Microsporogenesis of Polypleurum wallichi (R. Brown ex. Griff.) Warm. (Podostemaceae) growing in northeast India

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.

In vitro antioxidant activity of Ageratina adenophora (King & Rob) and Ipomoea cairica (L) Sweet

In this study, the in vitro antioxidant activity of the methanolic extracts of leaves and flowers of Ipomoea cairica and leaves of Ageratina adenophora were determined by spectrophotometric method. Antioxidant activity of extracts were expressed as percentage of DPPH radicals inhibition and IC50 values (μg/ml). Values in percentage ranged from 2.70 % for 0.0005 mg/ml concentration of I. cairica leaves to 93.24% for 0.05 mg/ml concentration of I.cairica flowers. The largest capacity to neutralize DPPH radicals was found for methanolic extract of I.cairica flowers which neutralized 50% of free radicals at the concentration of 1.00 μg/ml. I. cairica can be regarded as promising candidates for natural plant sources of antioxidants with high value.

Communication mechanism between living cells

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.

Symbiosis between Rhizobium and the non-legume, Polypleurum wallichii

Polypleurum wallichii is an aquatic plant found in East- Khasi Hill District of Meghalaya, in the Northeast India. The endophyte was successfully cultured using Tryptone-yeast medium. Holdfast as well as thallus showed Gram-negative bacterium resembling the bacterioids of Rhizobium, (designated as Polypleurum type-I) similar to nodules from Glycine max and other tropical legumes. The plant body of Polypleurum has poor vasculature and lack intercellular space, hence, no formation of distinct nodules. The observations indicate that the plant is a nitrogen fixing non-legume, and the endophyte bacterium is member of Rhizobium.

Evaluation of phytochemical contents of Ipomoea cairica (L) Sweet – a qualitative approach

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.

Molecular and phylogenetic analysis of the genus Orthetrum (Odonata: Anisoptera: Libellulidae) using mitochondrial CO1 gene

Molecular phylogenetic relationships among members of the odonate genus Orthetrum (Odonata: Anisoptera: Libellulidae) were examined using 403 bp of mitochondrial COI. The support for monophyly of the Orthetrum was found in some studies with unresolved complexity. The O. sabina, O. serapia and O. trincaria formed a seperate and distinct group from the morphological analysis. We analysed the COI sequences of 22 species of Orthetrum using MEGA6. The p-distance between the members and the rate of transitional and transversional substitution was generated. The analysis indicated that the Orthetrum are monophyletic and O. sabina and O. trinacria formed a disticnt and a seperate group.

Classification and provenance studies of the sandstones exposed along Durtlang road section, Aizawl, Mizoram

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.

Fostering scientific temper in Mizoram

This article celebrates the theme “Fostering Scientific Temper” of the Department of Science and Technology, Government of India. It emphasizes the need for breaking unscientific approaches to understanding nature and events in our lives, particularly stressing on those of the Mizo people. The linger belief that leaf insects and stick insects spontaneously transform from plants, that house lizards are venomous, that animal intestines are good for diabetes mellitus, and that malaria is spread through water. The indigenous notion that crocodiles are the male species, and gharials are the females, that two edible snails are males and females, porcupines can shoot their spines, and that the rough-skinned toads are leprous. This paper is an attempt to provide the scientific rationales of these apparent myths.

Mizo Academy of Sciences Annual Report 2013-2014

Recipient of MAS award - M. Sawmliana