Strain induced magnetic domain evolution and spin re-orientation transition in epitaxial manganite films

The evolution of magnetic domain structure in epitaxial La$_{0.625}$Ca$_{0.375}$MnO$_3$ films on (001) NdGaO$_3$ is monitored as a function of temperature and magnetic field using Magnetic Force Microscopy. We see two distinct regions of magnetic orientational order; one in-plane displaying contrast-less image and the other tilted away from the film plane forming a distinct stripe pattern. A strong domain splitting is observed at the boundary of two regions, which is resilient to reorientation with temperature and magnetic field. We propose a model magnetic free energy functional to explain the mechanism of domain splitting seen in manganite films

Electronic reconstruction and enhanced superconductivity at La1.6−x_{1.6-x}Nd0.4_{0.4}Srx_{x}CuO4_{4}/La1.55_{1.55}Sr0.45_{0.45}CuO4_{4} bilayer interface

We report enhanced superconductivity in bilayer thin films consisting of superconducting La$_{1.6-x}$Nd$_{0.4}$Sr$_{x}$CuO$_{4}$ with 0.06 $\leq x<$ 0.20 and metallic but non-superconducting La$_{1.55}$Sr$_{0.45}$CuO$_{4}$. These bilayers show a maximum increase in superconducting transition temperature ($T_c$) of more than 200% for $x$ = 0.06 while no change in $T_c$ is observed for the bilayers with $x\geq$ 0.20. The analysis of the critical current and kinetic inductance data suggests 2-3 unit cells thick interfacial layer electronically perturbed to have a higher $T_c$. A simple charge transfer model with cation intermixing explains the observed $T_c$ in bilayers. Still the unusually large thickness of interfacial superconducting layers can not be explained in terms of this model. We believe the stripe relaxation as well as the proximity effect also influence the superconductivity of the interface

Interface superconductivity in La1.48_{1.48}Nd0.4_{0.4}Sr0.12_{0.12}CuO4_{4}/La1.84_{1.84}Sr0.16_{0.16}CuO4_{4} bilayers

We identify a distinct superconducting phase at the interface of a La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_4$ (LNSCO)/La$_{1.84}$Sr$_{0.16}$CuO$_4$ (LSCO) epitaxial bilayer system using ac screening measurements. A model based on inter-diffusion of quasiparticles and condensate at the interface yields a thickness of $\sim$ 25 nm for the interfacial layer. Two-dimensional superconductivity of the interface layer appears to be governed by Kosterlitz-Thouless-Berezinskii transition. A parallel magnetic field suppresses the superconducting transition temperature of this layer with a pair breaking parameter $\alpha$ varying as $H^2$

Mineralogical characterization and sorption properties of goethite rich iron ore from daitari, Orissa, India

The present study was an attempt to find alternative uses of goethite rich iron ore, usually not used as raw material for iron extraction, as an adsorbent for removal of anionic contaminants from water. Mineralogical characterization by optical microscope, XRD revealed the presence of substantial amount goethite in the iron ore which was also supported from the TG-DTA and FT-IR results. On heating in air, the goethite content was completely converted to hematite at 400°C. The sorption behaviour of the untreated (GRI-0) and heat treated iron ore were studied using aqueous phosphate solution as the adsorbate with respect to effect of pH, initial phosphate concentration, amount of adsorbent, interfering anions and heat treatment. Phosphate uptake was seen to increase with increasing temperature of heat treatment, attains a maximum value at 300°C and thereafter decreased on further increase of temperature. The experimental equilibrium adsorption data were fitted well to Langmuir isotherm model. The complete desorption of adsorbed phosphate at pH ≥ 12.0 indicated the adsorption of phosphate was reversible and may be reused further. The results obtained could be useful for considering GRI-0 as adsorbent for removal of phosphate ions from contaminated water bodies

Silicon amendment induces synergistic plant defense mechanism against pink stem borer (Sesamia inferens Walker.) in finger millet (Eleusine coracana Gaertn.).

Silicon (Si) uptake and accumulation in plants can mitigate various biotic stresses through enhanced plant resistance against wide range of herbivores. But the role of silicon in defense molecular mechanism still remains to be elucidated in finger millet. In the present study, we identified three silicon transporter genes viz. EcLsi1, EcLsi2, and EcLsi6 involved in silicon uptake mechanism. In addition, the study also identified and characterized ten different Si transporters genes from finger millet through transcriptome assembly. The phylogenetic study revealed that EcLsi1 and EcLsi6 are homologs while EcLsi2 and EcLsi3 form another pair of homologs. EcLsi1 and EcLsi6 belong to family of NIP2s (Nod26-like major intrinsic protein), bona fide silicon transporters, whereas EcLsi2 and EcLsi3, an efflux Si transporter, belong to an uncharacterized anion transporter family having a significant identity with putative arsB transporter proteins. Further, the phylogenetic and topology analysis suggest that EcLsi1 and EcLsi2 co-evolved during evolution while, EcLsi2 and EcLsi3 are evolved from either EcLsi1 and/or EcLsi6 by fusion or duplication event. Moreover, these silicon transporters are predicted to be localized in plasma membrane, but their structural differences indicate that they might have differences in their silicon uptake ability. Silicon amendment induces the synergistic defense mechanism by significantly increasing the transcript level of silicon transporter genes (EcLsi1, EcLsi2 and EcLsi6) as well as defense hormone regulating genes (EcSAM, EcPAL and EcLOX) at 72 hpi (hours of post infestation) in both stem and roots compared to non-silicon treated plants against pink stem borer in finger millet plants. This study will help to understand the molecular defense mechanism for developing strategies for insect pest management

Genetic Variation and Population Structure in Jamunapari Goats Using Microsatellites, Mitochondrial DNA, and Milk Protein Genes

Jamunapari, a dairy goat breed of India, has been gradually declining in numbers in its home tract over the years. We have analysed genetic variation and population history in Jamunapari goats based on 17 microsatellite loci, 2 milk protein loci, mitochondrial hypervariable region I (HVRI) sequencing, and three Y-chromosomal gene sequencing. We used the mitochondrial DNA (mtDNA) mismatch distribution, microsatellite data, and bottleneck tests to infer the population history and demography. The mean number of alleles per locus was 9.0 indicating that the allelic variation was high in all the loci and the mean heterozygosity was 0.769 at nuclear loci. Although the population size is smaller than 8,000 individuals, the amount of variability both in terms of allelic richness and gene diversity was high in all the microsatellite loci except ILST 005. The gene diversity and effective number of alleles at milk protein loci were higher than the 10 other Indian goat breeds that they were compared to. Mismatch analysis was carried out and the analysis revealed that the population curve was unimodal indicating the expansion of population. The genetic diversity of Y-chromosome genes was low in the present study. The observed mean M ratio in the population was above the critical significance value (Mc) and close to one indicating that it has maintained a slowly changing population size. The mode-shift test did not detect any distortion of allele frequency and the heterozygosity excess method showed that there was no significant departure from mutation-drift equilibrium detected in the population. However, the effects of genetic bottlenecks were observed in some loci due to decreased heterozygosity and lower level of M ratio. There were two observed genetic subdivisions in the population supporting the observations of farmers in different areas. This base line information on genetic diversity, bottleneck analysis, and mismatch analysis was obtained to assist the conservation decision and management of the breed

Experimental studies on effect of speaking mode on spoken term detection

The objective of this paper is to study the effect of speaking mode on spoken term detection (STD) system. The experiments are conducted with respect to query words recorded in isolated manner and words cut out from continuous speech. Durations of phonemes in query words greatly vary between these two modes. Hence pattern matching stage plays a crucial role which takes care of temporal variations. Matching is done using Subsequence dynamic time warping (DTW) on posterior features of query and reference utterances, obtained by training Multilayer perceptron (MLP). The difference in performance of the STD system for different phoneme groupings (45, 25, 15 and 6 classes) is also analyzed. Our STD system is tested on Telugu broadcast news. Major difference in STD system performance is observed for recorded and cut-out types of query words. It is observed that STD system performance is better with query words cut out from continuous speech compared to words recorded in isolated manner. This performance difference can be accounted for large temporal variations

Two-dimensional electron-gas-like charge transport at magnetic Heusler alloy-SrTiO3_3 interface

We report remarkably low residual resistivity, giant residual resistivity ratio, free-electron-like Hall resistivity and high mobility ($\approx$ 10$^4$ cm$^2$V$^{-1}$s$^{-1}$) charge transport in epitaxial films of Co$_2$MnSi and Co$_2$FeSi grown on (001) SrTiO$_3$. This unusual behavior is not observed in films deposited on other cubic oxide substrates of comparable lattice parameters. The scaling of the resistivity with thickness of the films allow extraction of interface conductance, which can be attributed to a layer of oxygen vacancies confined within 1.9 nm of the interface as revealed by atomically resolved electron microscopy and spectroscopy. The high mobility transport observed here at the interface of a fully spin polarized metal is potentially important for spintronics applications