135 research outputs found
Hiding Encrypted Color Image within MPEG-2 Video
In any communication, security is the most important issue in today’s world. Lots of data security and data hiding algorithms have been developed in the last decade. Hiding data in digital videos makes possible to hide a great quantity of information when compared to techniques used in images. This work presents the encryption process of an image with combination of bit and pixel permutation technique depending on random key, and then steganography technique that hiding each bit of encrypted image in selected block 8*8 pixels(selected block process depending on high blue color ratio), of the frame and can extracted that bit after compressed with mpeg-2. Experimental results show the success of hidden extracted data from the sequence of frames, and also indicate the effectiveness of the implementation steganography compressed video with high security feature
Mitigation of salinity stress by exogenous application of cytokinin in faba bean (Vicia faba L.)
Soil salinity limits agricultural land use and crop productivity, thereby a major threat to global food safety. Plants treated with several phytohormones including cytokinins were recently proved as a powerful tool to enhance plant’s adaptation against various abiotic stresses. The current study was designed to investigate the potential role of 6-benzyladenine (BA) to improve broad bean (Vicia faba L.) salinity tolerance. The salt-stressed broad bean plantlets were classified into two groups, one of which was sprayed with water and another was sprayed with 200 ppm of BA. Foliar applications of BA to salt-exposed plants promoted the growth performance which was evidenced by enhanced root-shoot fresh and dry biomass. Reduced proline was strongly connected to the enhanced soluble proteins and free amino acids contents, protecting plant osmotic potential following BA treatment in salt-stressed broad bean. BA balanced entire mineral homeostasis and improved mineral absorption and translocation from roots to shoots, shoots to seeds and roots to seeds in salt-stressed plants. Excessive salt accumulation increased malondialdehyde level in leaves creating oxidative stress and disrupting cell membrane whereas BA supplementation reduced lipid peroxidation and improved oxidative defence. BA spray to salinity-stressed plants also compensated oxidative damage by boosting antioxidants defence mechanisms, as increased the enzymatic activity of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase. Moreover, clustering heatmap and principal component analysis revealed that mineral imbalances, osmotic impairments and increased oxidative damage were the major contributors to salts toxicity, on the contrary, BA-augmented mineral homeostasis and higher antioxidant capacity were the reliable markers for creating salinity stress tolerance in broad bean. In conclusion, the exogenous application of BA alleviated the antagonistic effect of salinity and possessed broad bean to positively regulate the osmoprotectants, ion homeostasis, antioxidant activity and finally plant growth and yield, perhaps suggesting these easily-accessible and eco-friendly organic compounds could be powerful tools for the management of broad bean growth as well as the development of plant resiliency in saline prone soils
Exogenous glutathione-mediated tolerance to deficit irrigation in salt-affected Capsicum frutescence (L.) plants is connected with higher antioxidant content and ionic homeostasis
As an important medicinal plant used in traditional and modern medicine, chili peppers are sensitive or moderately sensitive to drought or salt stress, respectively. Therefore, potential changes due to foliar-applied glutathione (GSH; 0, 0.4 and 0.8 mM) response on growth, yield, and physio-biochemical attributes, as well as water use efficiency (WUE) and fruit alkaloid capsaicin of chili pepper plants were investigated when grown under deficit irrigation in salt-affected soil (EC = 6.74 dS m–1). Two deficit irrigation water (DiW) regimes (80% and 60% of soil field capacity; FC) were used versus 100% of FC as a control. Both DiW treatments negatively affected growth and yield parameters, SPAD chlorophyll index, nutrient status, K+/Na+ ratio, and plant anatomical features. In contrast, osmoprotectants, ascorbate, glutathione, capsaicin, and phenolic contents, as well as WUE were increased in association with higher Na+ and Cl– contents. However, exogenously-applied GSH caused significant increases in the above-mentioned parameters along with an additional increase in osmoprotectants, antioxidants, and capsaicin contents, and a decrease in Na+ and Cl– levels compared to corresponding controls. The highest WUE, growth, and fruit yield responses were recorded at 0.8 mM GSH applied to plants under DiW at 80% FC + salinity (6.74 dS m–1). Therefore, this study suggested the use of leafy-applied GSH at 0.8 mM for satisfactory growth and yield with the highest WUE of chili pepper plants grown under salt-affected conditions with deficit irrigation
Molecular Detection of fnbA, fnbB and nuc Genes and Phenotypic Detection of some Virulence Factors in Local Staphylococcus aureus Isolates.
In this study, Staphylococcus aureus (S. aureus) isolates (32) were collected from different hospitals in Baghdad and were diagnosed by conventional methods. Antimicrobial susceptibility test was performed by disc diffusion method for ten antibiotics. Hemolytic production activity and Deoxy ribonuclease (DNase) production ability were detected. The biofilm production ability was detected by microtiter plate method. The diagnosis was confirmed using PCR to detect the thermostable nuclease gene (nuc). Then, PCR technique was used to detect the fibronectin binding protein A and fibronectin binding protein B genes (fnbA and fnbB respectively). The results showed a high prevalence (78%) of Methicillin-resistant Staphylococcus aureus (MRSA) isolates, Imipenem and vancomycin were the most affective antibacterial agents tested. All isolates produced DNase enzyme . On blood agar plate, 65.6% of isolates produced β-hemolysis zones while (34.4%) of isolates did not produce any hemolytic zone. The results of biofilm production assay showed that 41% of isolates gave a weak positive results. All isolates (100%) that had been previously diagnosed as S. aureus by routinely used methods harbored the nuc gene. fnbA and fnbB were found in (100%) and (25%) of isolates respectively. Conclusion: Molecular detection of nuc gene by PCR has high specificity for identifying S. aureus with a low cost which requires less time as compared with biochemical methods. fnbA and fnbB genes are important virulence factors of S. aureus. fnbA gene is the highest prevalence of toxinogenic and can be used as a genetic marker for diagnosis of local S. aureus isolates while fnbB gene does not play an important role in infection of S. aureus
Genetic and Morphological Diversity Assessment of Five Kalanchoe Genotypes by SCoT, ISSR and RAPD-PCR Markers
Determining the appropriate parents for breeding programs is the most important decision that plant breeders must make to maximize the genetic variability and produce excellent recombinant genotypes. Several methods are used to identify genotypes with desirable phenotypic features for breeding experiments. In this study, five kalanchoe genotypes were morphologically characterized by assessing plant height, number of inflorescences, number of flowers, flower length, flower diameter and number of petals. The analysis showed the distinction of yellow kalanchoe in the plant height trait, while the orange kalanchoe was distinguished in the number of inflorescences, the number of flowers and flower length traits, whereas the violet kalanchoe possessed the largest flower diameter and the highest number of petals. The molecular profiling was performed by random amplified polymorphism DNA (RAPD), inter-simple sequence repeats (ISSR) and start codon targeted (SCoT)-polymerase chain reaction (PCR) tools. Genomic DNA was extracted from young leaves and the PCR reactions were performed using ten primers for each SCoT, ISSR and RAPD marker. Only four out of ten primers showed amplicon profiles in all PCR markers. A total of 70 bands were generated by SCoT, ISSR and RAPD-PCR with 35 polymorphic bands and 35 monomorphic bands. The total number of bands of RAPD, ISSR and SCoT was 15, 17 and 38, respectively. The polymorphism percentages achieved by RAPD, ISSR and SCoT were 60.25%, 15% and 57%, respectively. The cluster analysis based on morphological data revealed two clusters. Cluster I consisted of violet and orange kalanchoe, and cluster II comprised red, yellow and purple kalanchoe. Whereas the cluster analysis based on molecular data revealed three clusters. Cluster I included only yellow kalanchoe, cluster II comprised orange and violet kalanchoe while cluster III comprised red, and purple kalanchoe. The study concluded that orange, violet and yellow kalanchoe are distinguished parents for breeding economically valued traits in kalanchoe. Also, the study concluded that SCoT and RAPD markers reproduced reliable banding patterns to assess the genetic polymorphism among kalanchoe genotypes that consider the basis stone for genetic improvements in ornamental plants
Tilted beam fabry-perot antenna with enhanced gain and broadband low backscattering
Communication with low radar signature platforms requires antennas with low backscatter, to uphold the low observability attribute of the platforms. In this work, we present the design for a Fabry–Perot (F-P) cavity antenna with low monostatic radar cross section (RCS) and enhanced gain. In addition, peak radiation is tilted inthe elevation plane. This is achieved by incorporating phase gradient metasurface (PGM) with absorptive frequency selective surface (FSS). The periodic surface of metallic square loops with lumped resistors forms the absorptive surface, placed on top of a partially reflecting surface (PRS) with an intervening air gap. The double-sided PRS consists of uniform metallic patches etched in a periodic fashion on its upper side. The bottom surface consists of variable-sized metallic patches, to realize phase gradient. The superstrate assembly is placed at about half free space wavelength above the patch antenna resonating at 6.6 GHz. The antenna’s ground plane and PRS together construct the F-P cavity. A peak gain of 11.5 dBi is achieved at 13◦ tilt of the elevation plane. Wideband RCS reduction is achieved, spanning 5.6–16 GHz, for x-and y-polarizations of normally incident plane wave. The average RCS reduction is 13 dB. Simulation results with experimental verifications are presented
Quarter wavelength fabry–perot cavity antenna with wideband low monostatic radar cross section and off-broadside peak radiation
Since antennas are strong radar targets, their radar cross section (RCS) reduction and radiation enhancement is of utmost necessity, particularly for stealth platforms. This work proposes the design of a Fabry–Perot Cavity (FPC) antenna which has wideband low monostatic RCS. While in the transmission mode, not only is gain enhancement achieved, but radiation beam is also deflected in the elevation plane. Moreover, the design is low-profile, i.e., the cavity height is ~λ/4. A patch antenna designed at 6 GHz serves as the excitation source of the cavity constructed between the metallic ground plane and superstrate. The superstrate structure is formed with absorptive frequency selective surface (AFSS) in conjunction with dual-sided partially reflective surface (PRS). Resistor loaded metallic rings serve as the AFSS, while PRS is constructed from inductive gradated mesh structure on one side to realize phase gradient for beam deflection; the other side has fixed capacitive elements. Results show that wideband RCS reduction was achieved from 4–16 GHz, with average RCS reduction of about 8.5 dB over the reference patch antenna. Off-broadside peak radiation at −38◦ was achieved, with gain approaching ~9.4 dB. Simulation and measurement results are presented
Investigation the nonlinear optical properties of silver nanoparticles using femtosecond laser
© 2020 Published under licence by IOP Publishing Ltd. In this research, the fabrication of silver nanoparticles and experimental nonlinear response (NLO). The fabrication of the silver nanoparticles has been done using E-Beam evaporation on a glass substrate (Ag-NPs) and investigation of their nonlinear optical response (NLO). The silver nanoparticles was evaluated by optical spectrum (UV-Vis) that shows localized surface Plasmon band at 375 nm. The experiment shows the nonlinear absorption and nonlinear refraction effect of silver nanoparticles, the silver nanoparticles is analysed by Z-Scan technique using a femtoseconds laser with 800 nm wavelength. The result shows the nonlinear absorption (NLA) is at 4.8710-4cmW-1, while (NLR) is at 7.9410-9cmW-1
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