Ravinder Singh

Effect of seed pre-soaking with 24-epibrassinolide on growth and photosynthetic parameters of Brassica juncea L. in imidacloprid soil.

Pesticides are widely used to protect crop plants from various insect pests. However, application of pesticides causes phytotoxicity to plants which results in their impaired growth and development. Brassinosteroids are well known to protect plants under abiotic stress conditions. The purpose of the present study was to access the ameliorative role of 24-epibrassinolide (EBR) in Brassica juncea L. under imidacloprid (IMI) toxicity. B. juncea plants were raised from seeds soaked in 0.1, 1 and 100nM of EBR, and grown in soils amended with 250, 300 and 350mgkg(-1) IMI pesticide, and observed for growth, pigments and photosynthetic parameters after 30, 60 and 90 days of seed sowing. The plants grown in soil treated with IMI exhibited a significant reduction in shoot length, number of leaves, chlorophyll contents and photosynthetic parameters like photosynthetic rate, stomatal conductance, inter-cellular CO2 and transpiration rate, when compared with their respective controls. However, pigments which act as antioxidants such as carotenoids, anthocyanins and xanthophylls were increased with IMI stress. Pre-sowing seed treatment with EBR decreased the toxic effects of IMI and increased the growth, pigment biosynthesis and photosynthetic parameters of the plants grown in IMI amended soil. Maximum increase in all the growth and photosynthetic parameters was noticed in plants raised from seeds treated with 100nM EBR and grown in IMI amended soil.

Anomalous behaviour of environment affected CR-39 at elevated temperatures

Abstract The evidence obtained indicates that the stability of latent tracks in CR-39 is affected by the environmental conditions which the detector experiences during annealing. The depth dependence bulk etch rate, balloon-like surface features are some of the anomalous observations that are discussed in the text. It has been observed that the ballooning affect is a function of annealing time and temperature. An attempt has been made to explain the chemical changes accompanying the anomalous behaviour of the detector.

Optical and Structural Modifications in Heavy Ion Irradiated Polystyrene

Samples of polystyrene (PS) have been irradiated with 64Cu (50 and 120 MeV) and 12C (70 MeV) ion beams (fluence=1011 to 1013 ions cm−2) in order to study the induced modifications using UV‐VIS and FTIR spectroscopy. UV spectra of irradiated samples reveal that the optical band gap decreases from 4.36 to 1.46 eV in PS. The decrease in optical band gap is more pronounced with the Cu‐ion beam due to high electronic energy loss as compared to the C ion beam. The effect of low energy (50 MeV) Cu ions on the optical properties of PS is larger than that due to high energy (120 MeV) Cu ions. The correlation between the optical band gap and the number of six member carbon rings inside the largest carbon clusters embedded in the network of polystyrene is discussed. FTIR spectra reveal the formation of hydroxyl, alkene, and alkyne groups in the Cu‐ion irradiated PS. Changes in the intensity of the absorption bands on irradiation with C‐ion relative to pristine samples have also been observed and are discussed.

Range and etching behaviour of swift heavy ions in polymers

Aliphatic (CR-39) and aromatic (Lexan polycarbonate) polymers have been irradiated with a variety of heavy ions such as 58Ni, 93Nb, 132Xe, 139La, 197Au, 208Pb, 209Bi, and 238U having energy ranges of 5.60–8.00 MeV/n in order to study the range and etching kinetics of heavy ion tracks. The ion fluence (range ∼104–105 ions/cm2) was kept low to avoid the overlapping of etched tracks. The measured values of maximum etched track length were corrected due to bulk etching and over etching to obtain the actual range. The experimental results of range profiles were compared with those obtained by the most used procedures employed in obtaining range and stopping power. The range values of present ions have been computed using the semiempirical codes (SRIM-98, SRIM-2003.26, and LISE++:0-[Hub90]) in order to check their accuracy. The merits and demerits of the adopted formulations have been highlighted in the present work. It is observed that the range of heavy ions is greater in aromatic polymers (Lexan polycarbonate) as compared to the aliphatic polymers (CR-39) irradiated with similar ions having same incident energies. The SRIM-98 and SRIM2003.26 codes don’t show any significant trend in deviations, however, LISE++:0-[Hub90] code provides overall good agreement with the experimental values. The ratio of track etch rate (along projectile trajectory) to the bulk etch rate has also been studied as a function of energy loss of heavy ions in these polymers.

ROS Compartmentalization in Plant Cells Under Abiotic Stress Condition

Reactive oxygen species (ROS) are generated in various plant organelles under normal conditions and play an important role in different physiological progressions. But under abiotic stress, excessive ROS generation takes place which causes damage to normal functioning of plants. ROS play a dual role as they cause cellular damage and are also involved in abiotic stress signaling. Therefore, it is important to investigate the features of appearance of physiological effects of ROS depending on their cellular localization under the abiotic stress. Plants possess certain antioxidative mechanisms to deal with excess ROS in the cells, which involves enzymatic and nonenzymatic antioxidants. In the review, the mechanisms of ROS formation in different cellular compartments like mitochondria, peroxisomes, chloroplasts, nucleus, vacuole, cell wall, and plasma membranes are considered and summarized.

Carbon (70 MeV) and copper (120 MeV) ions irradiation effects in Makrofol-N

Makrofol-N polycarbonate was irradiated with carbon (70 MeV) and copper (120 MeV) ions to analyze the induced effects with respect to optical and structural properties. In the present investigation, the fluence for carbon and copper beams was kept in the range of 1×1011– 1×1013 ions/cm2 to study the swift heavy ion induced modifications. UV–VIS, FTIR and XRD techniques were utilized to study the induced changes. The analysis of UV–VIS absorption studies revealed that the optical energy gap was reduced by 17% on carbon irradiation, whereas the copper beam leads to a decrease of 52% at the highest fluence of 1×1013 ions/cm2. The band gap can be correlated to the number of carbon atoms, N, in a cluster with a modified Robertsons equation. In copper (120 MeV) ions irradiated polycarbonate, the number of carbon atoms in a cluster was increased from 63 to 269 with the increase of ion fluence from 0 to 1×1013 ions/cm2, whereas N is raised only up to 91 when the same polymer films were irradiated with carbon (70 MeV) ions under similar conditions. FTIR analysis showed a decrease in almost all characteristic absorption bands under irradiation. The formation of hydroxyl (‒ OH) and alkene (C˭C) groups were observed in Makrofol-N at higher fluence on irradiation with both types of ions, while the formation alkyne end (R‒ C≡ CH) group was observed only after copper ions irradiation. The radii of the alkyne production of about 3.3 nm were deduced for copper (120 MeV) ions. XRD measurements show a decrease in intensity of the main peak and an increase of the average intermolecular spacing with the increase of ion fluence, which may be attributed to the structural degradation of Makrofol-N on swift ion irradiation.

Study of YAP Element among an Endogamous Human Isolate in Punjab

Abstract The blood samples of 66 Ahmadiyya Muslim males from Qadian, district Gurdaspur of Punjab have been analysed to study the Y-chromosome Alu insertion polymorphism (YAP). Y-chromosomes carrying the YAP element were found in many populations in India and Pakistan. However, the absence of YAP insertion element in the present Ahmadiyya population has suggested that this isolated population is not likely to have been affected by many migrations in Indian history.

Proton Irradiated Polystyrene as a Food Packaging Material

Thin polystyrene films are irradiated with protons (3MeV) under vacuum at room temperature with the absorbed dose ranging from 2 × 106 to 2 × 107 Gy. The changes in color, increase of cross-linking, and induction of microstrain on the surface of proton-irradiated polystyrene are investigated with UV-VIS, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) techniques, respectively. There are minimal changes in these properties up to 6 × 106 Gy, which is much more than the 25kGy radiations needed for sterilization.

Study of DYS 390 Polymorphism among Khatri Population of Punjab in Comparison to Other Indian and World Population

Abstract The Y chromosome specific polymorphism (Y-STR and Y-SNPs) can be used to track paternal lineages as well as male specific movements and admixture among humans. The objective of the present work is to study the genetic polymorphism at Y chromosome specific STR locus, DYS390 among Khatri population of Punjab and generate a comparative data with respect to other Indian and world populations. The DNA was isolated from blood samples of Khatri male individuals through organic method and were amplified by PCR using specific primers for DYS390 locus. The PCR products were electrophoresed on polyacrylamide gels and silver staining was done to resolve and observe different alleles. Gel-Pro 3.1 software was used to confirm the allele size. Chi-Square test was applied to test whether differences between the allele frequencies among Khatri, other Indian and world populations were statistically significant. Network Joining (NJ) tree was constructed using Network analysis software. The results showed 7 different alleles ranging from 22 to 28 in Khatri population and revealed a significantly high degree of genetic heterogeneity at this locus. The gene diversity was found to be 0.8363. The Network Joining tree showed Khatri population as an independent branch alongside Chinese. Therefore, it can be inferred that Khatri population is probably a result of conglomeration of different lineages, like most other North-West Indian population.

Copper (50 MeV) and Oxygen (84 MeV) Ion Irradiation Probed Thermal, Structural and Optical Behavior of Polyethylene Terephthalate

Abstract Polyethylene terephthalate (PET) films of 50u2009μm thickness were exposed to swift-heavy 50u2009MeV copper and 84u2009MeV oxygen ions, with fluence varying from 1u2009×u20091011 to 1u2009×u20091013 ions cm−2. Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) and UV-visible spectroscopic techniques were used to characterize the irradiated samples. The XRD and DSC analysis indicated the loss of crystallinity during/after the irradiation. The FTIR spectra revealed the formation of alkyne end groups, Cue5fbC groups and structural deformation with increase of ion fluence. Considerable reduction in the value of the optical bandgap was inferred from the study of the UV-visible absorption curves.