Genetic characterisation of indigenous duck of Tripura state in India using microsatellite markers.

Exploring genetic variability by microsatellite markers is essential for genetic improvement, preservation of indigenous germplasm and production of high-quality offspring. Lack of information on microsatellite profiling of Indian indigenous ducks (Tripura state) has stoked curiosity in this work. Genomic DNA samples from randomly selected 36 native ducks were analysed at 25 duck-specific microsatellite loci. Alleles were separated through 3.4% MetaPhore™ agarose gel electrophoresis. Allele sizes were determined using Image Lab 6 software of GelDoc™ EZ System. Allelic data were analysed by POPGENE version 1.31. Total 112 alleles were resolved and all the loci were found polymorphic with 2 to 15 alleles across the loci. Average number of allele (Na) was 4.480 ± 0.659. Allele sizes and frequencies ranged from 96 to 357 bp and 0.014 to 0.819, respectively. Average heterozygosity of Nei, effective number (Ne) of alleles and Shannon's information index (I) were 0.617 ± 0.036, 3.538 ± 0.527 and 1.184 ± 0.112, respectively. The estimates of Ne were less than the Na at all the loci, indicating prevalence of heterozygosity. Polymorphic information content (PIC) ranged from 0.252 (CAUD020) to 0.911 (CAUD019) with an average of 0.562 ± 0.040. Sixteen loci were moderate to highly polymorphic and informative (PIC ˃ 0.5). Chi-square and G-square statistics revealed Hardy-Weinberg disequilibrium at all the loci. Moderate to high level of polymorphism of the studied microsatellites indicated that these markers might be helpful for genetic characterisation and adoption of appropriate conservation strategies to exploit optimum genetic potentiality of indigenous ducks of Tripura.

Nanodoping: a route for enhancing electro-optic performance of bent core nematic system.

We report the effect of dispersion of barium titanate (BaTiO3) nanoparticles (BNPs) in a four ring bent core nematic (BCN) liquid crystal. Polarizing optical microscopy reveals the presence of a single nematic phase in pure and doped states. Polar switching has been observed in the bent core system and the value of spontaneous polarization (P s) increases with increase in doping concentration of BNPs in BCN. Dielectric study shows a lower frequency mode, which can be ascribed to the formation of cybotactic clusters. These clusters are also responsible for the observed polar switching in pure, as well as, in doped BCNs. Another higher frequency mode, observed only in pure BCN, indicates the rotation of molecules about their long molecular axis. The conductivity of doped samples is also found to decrease as compared to the pure BCN. This reduction helps in the minimization of negative effects caused by free ions in liquid crystal based devices. This study demonstrates that the interaction between BNPs and BCN molecules improves the P s, dielectric behaviour, viscosity and reduces the conductivity of pure BCN. Hence, nanodoping in a BCN is an effective method for the enhancement of electro-optic performances and will lead to the development of faster electro-optic devices.

Highly Polarized Fluorescent Illumination Using Liquid Crystal Phase.

Liquid crystal (LC) materials are currently the dominant electronic materials in display technology because of the ease of control of molecular orientation using an electric field. However, this technology requires the fabrication of two polarizers to create operational displays, reducing light transmission efficiency below 10%. It is therefore desirable to develop new technologies to enhance the light efficiency while maintaining or improving other properties such as the modulation speed of the molecular orientation. Here we report a uniaxial-oriented B7 smectic liquid crystalline film, using fluorescent bent-core LC molecules, a chemically modified substrate, and an in-plane electric field. A LC droplet under homeotropic boundary conditions of air/LC as well as LC/substrate exhibits large focal conic like optical textures. The in-plane electric field induced uniaxial orientation of the LC molecules, in which molecular polar directors are aligned in the direction of the electric field. This highly oriented LC film exhibits linearly polarized luminescence and microsecond time-scale modulation characteristics. The resultant device is both cheap and easy to fabricate and thus has great potential for electro-optic applications, including LC displays, bioimaging systems, and optical communications.