Antioxidant Enzymatic Activities and Gene Expression Associated with Heat Tolerance in the Stems and Roots of Two Cucurbit Species (“Cucurbita maxima” and “Cucurbita moschata”) and Their Interspecific Inbred Line “Maxchata”

The elucidation of heat tolerance mechanisms is required to combat the challenges of global warming. This study aimed to determine the antioxidant enzyme responses to heat stress, at the enzymatic activity and gene expression levels, and to investigate the antioxidative alterations associated with heat tolerance in the stems and roots of squashes using three genotypes differing in heat tolerance. Plants of heat-tolerant “C. moschata”, thermolabile “C. maxima” and moderately heat-tolerant interspecific inbred line “Maxchata” genotypes were exposed to moderate (37 °C) and severe (42 °C) heat shocks. “C. moschata” exhibited comparatively little oxidative damage, with the lowest hydrogen peroxide (H₂O₂), superoxide (O₂⁻) and malondialdehyde (MDA) contents in the roots compared to stems, followed by “Maxchata”. The enzyme activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POD) were found to be increased with heat stress in tolerant genotypes. The significant inductions of FeSOD, MnSOD, APX2, CAT1 and CAT3 isoforms in tolerant genotypes suggested their participation in heat tolerance. The differential isoform patterns of SOD, APX and CAT between stems and roots also indicated their tissue specificity. Furthermore, despite the sequence similarity of the studied antioxidant genes among “C. maxima” and “Maxchata”, most of these genes were highly induced under heat stress in “Maxchata”, which contributed to its heat tolerance. This phenomenon also indicated the involvement of other unknown genetic and/or epigenetic factors in controlling the expression of these antioxidant genes in squashes, which demands further exploration.     

Anomalous ferroelectric and magnetic behavior in BPFO-NZFO multiferroic nano-composites

Multiferroic nano-composites (1-x) Bi_.9Pr_.1FeO₃ (BPFO) –x Ni_.5Zn_.5Fe₂O₄ (NZFO) for x?=?0.0, 0.1, 0.2, 0.3 and 1.0 were synthesized by sol-gel auto-combustion method. Detailed investigations were made on the structural, morphological, ferroelectric, magnetic and dielectric properties of these nano-composites. The X-ray Diffraction pattern confirms the co-existence of perovskite BPFO and spinel NZFO phases without any impurity. The average particle size of as prepared BPFO and NZFO nanoparticles is nearly equal to 110?nm and 35?nm respectively which have been confirmed by the XRD and Transmission Electron Microscopy analysis. Structural and surface morphology are studied by Scanning Electron Microscopy. The dielectric properties of the composites are also studied at room temperature. The magnetic hysteresis loop has been studied to know the magnetic response of samples to the applied magnetic field of ±?1?T at room temperature. The saturation and remnant magnetization are found to increase with increase in NZFO weight percentage in the composite. The saturation magnetization values are 8.57?emu/g, 16.71?emu/g, 24.41?emu/g and remnant magnetization values are 0.78?emu/g, 1.23?emu/g, 1.58?emu/g for BPFO-NZFO 1, 2, 3 composite samples respectively. An anomalous ferroelectric behavior of BPFO-NZFO 1 composite sample was observed which can be understand with the help of observed results in dielectric and morphology of the samples. The incorporation of BPFO and NZFO enhances the multiferroic properties in the present composite materials which are quite promising from application point of view.     

Seed morphology using SEM techniques for identification of useful grasses in Dera Ghazi Khan,Pakistan

In recent study, 15 taxa of family Poaceae from Dera Ghazi Khan were investigated for morphological characterization of seeds. Scanning electron microscopy (SEM) was utilized to study morphological features of grass seeds. Moreover, economic importance of studied taxa has been discussed in present research. Grass seeds or caryopsis were collected in their mature state from different areas of Dera Ghazi Khan. Collected caryopses were subjected to SEM to investigate surface sculpture, epidermal cell shape, and cell wall patterns. Caryopsis shape observed was elliptic to oval. Also, the morphology of plant is being investigated. Cell wall pattern observed was straight and wavy. Surface sculpturing varies from smooth to reticulate. Epidermal cell shape was either wavy or irregular. Hilum position is terminal in all species. Epidermal cell structure and cell wall pattern was not observable in some species. Major variations among studied taxa were observed in terms of seed surface pattern. Five types of caryopsis surface pattern were observed namely, striate, smooth, reticulate, papillate, and granulate. Investigated taxa illustrated variations in terms of studied morphological features. Utilization of SEM has been proved very helpful in exploring seed morphological features. These observed features can aid in delimitation and identification of various grass taxa. Recent research recommends the utilization of SEM for caryopsis morphology to solve the identification issue of problematic grass genera.     

Eye gaze tracking based directional control interface for interactive applications

This paper proposes an unobtrusive and calibration-free framework towards eye gaze tracking based interactive directional control interface for desktop environment using simple webcam under unconstrained settings. The proposed eye gaze tracking involved hybrid approach designed by combining two different techniques based upon both supervised and unsupervised methods wherein the unsupervised image gradients method computes the iris centers over the eye regions extracted by the supervised regression based algorithm. Experiments performed by the proposed hybrid approach to detect eye regions along with iris centers over challenging face image datasets exhibited exciting results. Similar approach for eye gaze tracking worked well in real-time by using a simple web camera. Further, PC based interactive directional control interface based upon iris position has been designed that works without needing any prior calibrations unlike other Infrared illumination based eye trackers.

The proposed work may be useful to the people with full body motor disabilities, who need interactive and unobtrusive eye gaze control based applications to live independently.

     

Mobile FD-CR with High-Speed VTFET CMOS SOI Switch Under Channel Estimation Error

Silicon - In this paper, Silicon-on-Insulator vertical TFET based CMOS high-speed switch is implemented on Full-duplex Cognitive Radio (FD-CR), and the impact of cognitive radio (CR) node mobility...     

A systematic approach to the search for variational principles for plane steady flows

Using Vainberg's theorem of nonlinear potential operators, alternate potential principles associated with the differential equations governing the gasdynamics of plane steady irrotational diabatic flow and isoenergetic rotational adiabatic flow are formulated and their equivalence with Bateman's principle is established. Further, the advantage usefulness of treating a single nonlinear equation for the existence and hence formulation of a functional over the equivalent system for the same problem is brought into sharper focus.     

Novel microwave assisted synthesis of highly doped phase pure Nd:YAG nanopowder

For the first time, the studies on 2 to 10 at.% neodymium (Nd³⁺) ion doped Yttrium Aluminum Garnet (Nd:YAG) nanopowders obtained by microwave assisted citrate nitrate gel combustion synthesis is described in this work. This paper reports on high doping of Nd³⁺ ions with retaining the cubic garnet structure of YAG as evidenced from XRD, except the case of 8 at.% doped Nd:YAG. Phase pure YAG formation with 8 at.% Nd³⁺ doping was explored by using urea and alanine as alternative to citric acid complexing agents. Complete crystallization of YAG as a result of 2 hour thermal treatment at 900 °C under oxygen supply was studied by using Fourier Transform Infra-Red Spectroscopy (FTIR) and X-Ray Diffraction (XRD) techniques. With an increase in the dopant concentration a red shift in the FTIR peaks was observed. Using the XRD data, the cell parameter of Nd³⁺ (2 to 6 and 10 at.%) YAG was found to increase with an increase in the dopant concentration. The average primary particle size calculated using Scherrer’s equation was ～25 nm which was additionally supported by Transmission Electron Microscopy (TEM) results yielding particle sizes in the range of ～25 to 30 nm for all the cases.