Al–Sc and Al–Sc–Zr alloys containing 0.05, 0.1 and 0.5
wt.% Sc and 0.15
wt.% Zr were investigated using optical microscopy, electron microscopy and X-ray diffraction. The phase composition of the ...alloys and the morphology of precipitates that developed during solidification in the sand casting process and subsequent thermal treatment of the samples were studied. XRD analysis shows that the weight percentage of the Al
3Sc/Al
3(Sc, Zr) precipitates was significantly below 1% in all alloys except for the virgin Al0.5Sc0.15Zr alloy. In this alloy the precipitates were observed as primary dendritic particles. In the binary Al–Sc alloys, ageing at 470
°C for 24
h produced precipitates associated with dislocation networks, whereas the precipitates in the annealed Al–Sc–Zr alloys were free of interfacial dislocations except at the lowest content of Sc. Development of large incoherent precipitates during precipitation heat treatment reduced hardness of all the alloys studied. Growth of the Al
3Sc/Al
3(Sc, Zr) precipitates after heat treatment was less at low Sc content and in the presence of Zr. Increase in hardness was observed after heat treatment at 300
°C in all alloys. There is a small difference in hardness between binary and ternary alloys slow cooled after sand casting.
The detection of selection signatures assists in understanding domestication, evolution, and the identification of genomic regions related to adaptation and production traits in buffaloes. The ...emergence of high-throughput technologies like Next Generation Sequencing and SNP genotyping had expanded our ability to detect these signatures of selection. In this study, we sought to identify signatures of selection in five buffalo populations (Brazilian Murrah, Bulgarian Murrah, Indian Murrah, Nili-Ravi, and Kundi) using Axiom Buffalo 90 K Genotyping Array data. Using seven different methodologies (Tajima's D, CLR, ROH, iHS, F
ST
, FLK and hapFLK), we identified selection signatures in 374 genomic regions, spanning a total of 381 genes and 350 quantitative trait loci (QTLs). Among these, several candidate genes were associated with QTLs for milk production, reproduction, growth and carcass traits. The genes and QTLs reported in this study provide insight into selection signals shaping the genome of buffalo breeds. Our findings can aid in further genomic association studies, genomic prediction, and the implementation of breeding programmes in Indian buffaloes.
Socioeconomic developments and industrialization exert tremendous impact on beaches which is often neglected. Heavy metal (Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb) contents were estimated in the ...intertidal region from Kalpakkam to Mamallapuram (20 km), southeast coast of India covering seven locations. To evaluate the level of contamination of these metals; enrichment factor (EF), geoaccumulation index (I gₑₒ), contamination factor (CF), pollution load index (PLI) and modified degree of contamination (mCd) were applied. The results were also compared with the sediment quality guidelines (SQGs) to find out the eco-toxicity level. Metal contents in the beach sediment were observed in the order: Fe > Al > Mn > Cr > Cu > Ni > Zn > Pb > Co > Cd. Grain size distribution showed medium to coarse nature of the sediment. Significant positive correlation was found among the metals indicating their common source of input. Based on EF, minor enrichment of Mn and Zn and moderately severe to severe enrichment of Cr, Cu, Pb and Cd were observed which was further confirmed by I gₑₒ and CF values. Moreover, Mamallapuram showed a very high CF value for Cd (>6) indicating very high contamination accountable to anthropogenic sources. PLI and mCd in all the stations indicated unpolluted nature except M1 where the values pointed moderate degree of contamination. As per the SQGs, Ni and Cr values exceeded the probable effect limit value implying that these metals can have adverse impacts. None of the metals exceeded the effect range median indicating that the beach sediment is not very toxic.
The increase of spikelet number in the panicles of modern super rice has made the architecture compact, as the extra spikelets are accommodated mostly on secondary branches than on primary branches. ...However, the grain yield did not improve because of poor grain filling, which was more visible in the basal spikelets than apical spikelets. The objective of this study was to examine the effect of the compactness and positional difference of spikelets in the panicle on grain filling by comparing the activity and genetic expression of starch synthesising enzymes in the developing kernels of lax-(Upahar and CR3856–45–11–2-7–2-5 (CR-45)) and compact-(Mahalaxmi and CR3856–29–14–2-1–1-1 (CR-29)) panicle cultivars. Upahar and Mahalaxmi are genetically related, whereas CR-45 and CR-29 are recombinant inbred lines. The grain carbohydrate concentration and activity of sucrose synthase (SUS) enzyme were estimated during the active period of grain filling. Further, expression of isoforms of SUS, ADP glucose pyrophosphorylase (APL and APS for large and small units respectively) and starch synthase (SS and GBSS for soluble and granule bound starch synthases respectively) were also assayed through PCR studies. The genotype approach used revealed grain SUS activity and starch concentration high and sugar concentration low in the lax- compared with compact-panicle cultivars and in the apical spikelets compared with basal ones. The margin of variation between apical and basal spikelets was higher in the compact- than the lax-panicle cultivars. Genetic expression of most of the isoforms of the enzymes was higher in the lax- than the compact-panicle cultivars as seen in RT–PCR studies. A quantitative appraisal of transcript levels of isoforms in the qRT–PCR identified greater expression of SUS3 in the basal spikelets of Upahar than that in Mahalaxmi and in CR-45 over CR-29, most prominently during the active period of grain filling. We conclude that proximal location as well as increased density of spikelets on panicles affected SUS3 expression in the basal spikelets. The metabolic dominance of a spikelet in rice panicle is dependent on the expression of the genes for different isoforms of starch synthesising enzymes, but the expression of SUS3 could be more specific than the others. SUS3 expression is most active during grain filling of the lax-panicle cultivars, but its dominance is reduced significantly in the kernels of the compact-panicle cultivars.
Copy number variations (CNVs) are major forms of genetic variation with an increasing importance in animal genomics. This study used the Illumina BovineSNP 50 K BeadChip to detect the genome-wide ...CNVs in the Tharparkar cattle. With the aid of
software, we noticed a total of 447 copy number variation regions (CNVRs) across the autosomal genome, occupying nearly 2.17% of the bovine genome. The average size of detected CNVRs was found to be 122.2 kb, the smallest CNVR being 50.02 kb in size, to the largest being 1,232.87 Kb. Enrichment analyses of the genes in these CNVRs gave significant associations with molecular adaptation-related Gene Ontology (GO) terms. Most CNVR genes were significantly enriched for specific biological functions; signaling pathways, sensory responses to stimuli, and various cellular processes. In addition, QTL analysis of CNVRs described them to be linked with economically essential traits in cattle. The findings here provide crucial information for constructing a more comprehensive CNVR map for the indigenous cattle genome.
Growth of monodispersed AlGaN nanowires of ternary wurtzite phase is reported using the chemical vapor deposition technique in the vapor–liquid–solid process. The role of distribution of Au catalyst ...nanoparticles on the size and shape of AlGaN nanowires is discussed. These variations in the morphology of the nanowires are understood invoking Ostwald ripening of Au catalyst nanoparticles at high temperature followed by the effect of single and multiprong growth mechanism. Energy-filtered transmission electron microscopy is used as an evidence for the presence of Al in the as-prepared samples. A significant blue shift of the band gap, in the absence of quantum confinement effect in the nanowires with diameter ∼100 nm, is used as a supportive evidence for the AlGaN alloy formation. Polarized resonance Raman spectroscopy with strong electron–phonon coupling along with optical confinement due to the dielectric contrast of nanowire with respect to that of surrounding media are adopted to understand the crystalline orientation of a single nanowire in the subdiffraction limit of ∼100 nm using 325 nm wavelength, for the first time. The results are compared with the structural analysis using high resolution transmission microscopic study.
The present broad range of sheep phenotypic variation is the consequence of selection for various production characteristics such as wool, milk, meat, and natural adaptability to diverse situations. ...In the current study, the genomic data of 79 animals from three Indian sheep breeds (Changthangi, Deccani, and Garole) were explored to decipher regions under positive selection for various productive traits using various statistical tools. We found 61, 102 regions using Tajima's D, CLR and 58, 38, and 71 regions using F
ST
, FLK, and hapFLK, respectively, under selective sweep. Significant candidate genes related to various important traits, such as KLHL for fibre diameter and the OMA1 gene for feed-induced thermogenesis in Changthangi, were identified. In addition, the SYCP2 and NAPAS3 genes were found to be associated with seasonal reproductivity, and BMPR1B for fertilization capacity in Garole. In a previous study, the HSPA6 gene (Garole) was found to be associated with thermo-tolerance in the Angus sheep breed. The outcomes discussed here provide a basis for detecting selective sweeps that underlie genetic variations of traits that have functional importance.
Knowledge about genetic diversity is very essential for the management and sustainable utilization of livestock genetic resources. In this study, we presented a comprehensive genome-wide analysis of ...genetic diversity, ROH, inbreeding, linkage disequilibrium, effective population size and haplotype block structure in Tharparkar cattle of India. A total of 24 Tharparkar animals used in this study were genotyped with Illumina BovineSNP50 array. After quality control, 22,825 biallelic SNPs were retained, which were in HWE, MAF > 0.05 and genotyping rate >90%. The overall mean observed (H
O
) and expected heterozygosity (H
E
) were 0.339 ± 0.156 and 0.325 ± 0.129, respectively. The average minor allele frequency was 0.234 with a standard deviation of ± 0.131. We identified a total of 1832 ROH segments and the highest autosomal coverage of 13.87% was observed on chromosome 23. The genomic inbreeding coefficients estimates by F
ROH
, F
HOM
, F
GRM
and F
UNI
were 0.0589, 0.0215, 0.0532 and 0.0160 respectively. The overall mean linkage disequilibrium (LD) for a total of 133,532 pairwise SNPs measured by D' and r
2
was 0.6452 and 0.1339, respectively. In addition, we observed a gradual decline in effective population size over the past generations.
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