Heterogeneity in Ty1-copia group of retroelements in chickpea (Cicer arietinum) genome

Retrotransposons constitute a major fraction of plant genomes and these elements may have played a significant role in evolution and sequence organization of genomes. In order to access the diversity of Ty1-copia group of retroelements, reverse transcriptase (RT) sequences were amplified from chickpea genome, using the primers derived from two conserved domains of RT region. Thirty-six RT regions from independent amplicons were cloned and sequenced. On the basis of homology of deduced amino acids, the RT sequences could be grouped into three major families. The intra-family divergence at amino acid level ranges from 2 to 19%. Though intra-family RT sequences were conserved but no two sequences were identical. The results indicate a high degree of heterogeneity among the Ty1-copia group of retroelements from chickpea. It was possible to isolate RT specific sequences from RNA isolated from stressed seedlings, indicating that some of the retroelements may be functional under certain stress conditions

CARE1, a TY3-gypsy long terminal repeat retrotransposon in the food legume chickpea (Cicer arietinum L)

We report a novel Ty3-gypsy long terminal repeat retrotransposon CARE1 (_Cicer arietinum_ retro-element 1) in chickpea. This 5920-bp AT-rich (63%) element carries 723-bp 5' and 897-bp 3' LTRs respectively flanking an internal region of 4300-bp. The LTRs of CARE1 show 93.9% nucleotide identity to each other and have 4-bp (ACTA) terminal inverted repeats. A 17-bp potential tRNAmet primer binding site downstream to 5' LTR and a 13-bp polypurine tract upstream to 3' LTR have been identified. The order of domains (Gag-proteinase-reverse transcriptase-RNaseH-integrase) in the deduced amino acid sequence and phylogenetic tree constructed using reverse transcriptase sequences places CARE1 in the gypsy group of retrotransposons. Homologues of a number of _cis_-elements including CCAAT, TATA and GT-1 have been detected in the regulatory region or the 5' LTR of CARE1. Transgenic tobacco plants containing 5' LTR:GUS construct show that its 5'-LTR is inactive in a heterologous system under normal as well as tissue culture conditions. Genomic Southern blot experiments using 5’LTR of the element as a probe show that CARE1 or its related elements are present in the genomes of various chickpea accessions from various geographic regions

Quaternion Gravi-Electromagnetism

Defining the generalized charge, potential, current and generalized fields as complex quantities where real and imaginary parts represent gravitation and electromagnetism respectively, corresponding field equation, equation of motion and other quantum equations are derived in manifestly covariant manner. It has been shown that the field equations are invariant under Lorentz as well as duality transformations. It has been shown that the quaternionic formulation presented here remains invariant under quaternion transformations.Comment: Key Words: Quaternion, dyons, gravito-dyons, gravi-electromagnetism. PACS No.: 04.90. +e ; 14.80. H

Prestressed concrete targets under high rate of loading

© The Author(s) 2018. Prestressed concrete is highly being preferred as material for construction in the case of strategic and relevant structures such as, for instance, nuclear containments, armor deposits, shelters, bridges, and military bunkers. It is highly durable, fire and corrosion resistant, and non-porous. In order to study the influence of prestressing on the mechanics of deformation, energy absorption capacity, and failure modes of concrete targets, finite element simulations have been carried out using hard steel bullets and compared with the experiments carried out by the authors earlier. Prestressed concrete targets of plan size 450 mm × 450 mm and thickness of 80 mm were impacted by 0.5-kg hard steel projectiles. The concrete was designed to obtain an unconfined compressive strength of 48 MPa. An initial stress of 10% magnitude of compressive strength was induced by 4-mm-diameter high-tensile-strength (1700 MPa) steel wires in prestressed concrete targets. A grid of 8-mm-diameter steel bars was inserted in the reinforced and prestressed concrete targets to enable the straight comparison between these concretes. The prestressing in concrete has been found to be effective in reducing the volume of scabbed material as well as the ballistic resistance of prestressed concrete targets. The ballistic limit of prestressed concrete with 10% induced stress was found to be, respectively, 14% higher than that of the plain concrete target and 10.2% higher than the reinforced concrete. Failure modes predicted through finite element simulations were found in agreement with that of the actual results

Investigation of ion induced bending mechanism for nanostructures

Ion induced bending is a promising controlled technique for manipulating nanoscale structures. However, the underlying mechanism of the process is not well understood. In this letter, we report a detailed study of the bending mechanism of Si nanowires (NWs) under Ga+ irradiation. The microstructural changes in the NW due to ion beam irradiation are studied and molecular dynamics simulations are used to explore the ion–NW interaction processes. The simulation results are compared with the microstructural studies of the NW. The investigations inform a generic understanding of the bending process in crystalline materials, which we suggest to be feasible as a versatile manipulation and integration technique in nanotechnology