ASSESSING THE IMPACT OF SEX-SPECIFIC MICROSATELLITE VARIANTS ON PHENOMICS OF INBRED SWISS ALBINO MICE

An inbred strain limits the segregating variance and provides more power and requires fewer experimental animals to produce good reproducibility. This study was undertaken with the aim to assess the impact of sex of offsprings and sex specific microsatellite variants on performance and fitness traits in F4 inbred Swiss albino mice. The phenomics of different performance and fitness traits were estimated on 506 F4 inbred mice population. Two ‘X’ chromosome specific microsatellite loci (DXMit187 and DxMit172) were used for PCR-Microsatellite genotyping of 102 F4 inbred population. PIC estimates showed that both the loci were informative for the population. In the current population, with the increasing level of “F” a declining trend was observed for Body weight at birth (BWB), Body weight at weaning (BWW), Litter size at weaning (LSW) and Litter weight at weaning (LWW). In F4 inbred population, BWW and ABW for males (17.32±0.32g and 30.81±0.31g) were significantly (p<0.05) higher than females (16.39±0.30g and 27.83±0.28g). The significant (p<0.05) impact of sex of offspring on performance traits revealed that less magnitude of inbreeding depression was observed in male as compared to female. There were 3 alleles and 5 genotypes at the DXMit172 locus, and 3 alleles and 4 genotypes at the DXMit187 locus. The highest and lowest allelic frequencies were found at DXMit172 locus for 142 (0.422) and 154 (0.226) alleles, respectively, and at DXMit187 locus for 126 (0.588) and 146 (0.093) alleles, respectively. Genotype 142/142 (0.382) and 154/148 (0.059) had the highest and lowest genotypic frequency at the DXMit172 locus, respectively, and at DXMit187 locus for 126/126 (0.588) and 146/146 (0.039) genotypes, respectively. In the current study, only the DXMit172 loci had significant genotypic associations with fitness traits (p<0.05). The average FIS based on X- specific microsatellite markers was 0.790 in the F4 inbred population. These results indicate that rate of inbreeding depression is more in females than in males

Anomalous influence of grain size on the global structure, ferroelectric and piezoelectric response of Na0.5Bi0.5TiO3

Na0.5Bi0.5TiO3 (NBT) based lead-free piezoelectrics have received significant attention in the last few years for their anomalous high-field electrostrain response. The positional disorder on the nano/meso scale in these systems have a profound effect on their perceived global structure and dielectric properties. Here we have carried out a systematic analysis of the grain size dependent structural, ferroelectric, piezoelectric and high temperature electrical conduction behaviour of NBT. We show that the global monoclinic lattice distortion collapses even while the grains are unusually large (similar to 2.5 mu m). We also found that the polarization switching ability and piezoelectric response of bulk NBT ceramics reduce drastically when grains are submicron in size. We use a powder poling technique to prove that the significant reduction of piezoelectricity in the submicron grain ceramic is not due to suppression of ferroelectricity within the grains itself, but rather due to inability of the grains to transform collectively to a long range rhombohedral ferroelectric state, either because of the clamping effect and/or enhanced incoherence of the grain boundaries. We also noted a qualitative change in the electrical conduction behaviour as a function of grain size and comment on a possible correlation between the grain size, global structure, piezoelectric response and oxygen ion conductivity of this lead-free compound. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Influence of Cr3+ doping on multiferroic properties in the morphotropic phase boundary compositions of BiFeO3-PbTiO3 system

In this paper, we have investigated the effect of Cr3+ substitution on the crystal structure, microstructure, dielectric and magnetic behavior of the morphotropic phase boundary (MPB) composition of the multiferroic ceramic 0.675BiFe((1-x))Cr(x)O(3)-0.325PbTiO(3) (x = 0, 0.02 and 0.05). The average grain size of the specimens increased from similar to 150 nm for x = 0 to 470 nm for x = 0.05. Rietveld refinement analysis of the X-Ray powder diffraction patterns confirmed the coexistence of multiphase i.e. monoclinic Cc and tetragonal P4 mm polymorphs for all the compositions. The system exhibits weak ferromagnetism for x = 0.05. We estimated the magnetoelectric interaction constant (gamma similar to 0.31) for x = 0.05 by Ginzburg-Landau theory. The value of magnetoelectric coupling coefficient is found to be 0.054 mV/cm-Oe, 0.073 mV/cm-Oe, 0.133 mV/cm-Oe for x = 0, 00.02 and 0.05, respectively. High temperature dielectric data also reveals that Curie temperature decreases with increasing Cr3+ concentration

Magnetic, ferroelectric, and magnetodielectric properties of BiFeO3 ceramic co-doped with Eu and Gd

Polycrystalline samples of Bi0.9Eu0.1FeO3, Bi0.9Gd0.1FeO3, and Bi0.9Eu0.05Gd0.05FeO3 ceramics were synthesized by a solid-state reaction method, followed by rapid quenching to room temperature. Bio(0.9)Eu(0.1)FeO(3) shows higher magnetization than Bi0.9Gd0.1FeO3 and Bi5.9Eu0.05Gd0.05FeO3. This can be explained by lattice distortion, and the change in the statistical distribution of Fe3+ /Fe2+. Similarly, ferroelectric polarization of Bi0.9Eu0.1FeO3 was found to be higher than that of Bi0.9Gd0.1FeO3 and Bi0.9Eu0.05Gd0.05FeO3. However, the absolute value of the magnetocapacitance of Bi0.9Eu0.05Gd0.05FeO3 (similar to 1.6%) was found to be higher than that of Bi0.9Eu0.1FeO3 (similar to 1.3%) and Bi0.9Gd0.1FeO3 (similar to 1.1%). In addition, the quadratic component of magnetoelectric coupling is higher for Bi0.9Eu0.05Gd0.05FeO3, which makes Bi0.9Eu0.05Gd0.05FeO3 attractive for further study