Electronic Beam Switching of Circularly Polarized Plasma Magneto-Electric Dipole Array with Multiple Beams

In this paper, different array arrangements based on magneto-electric (ME) dipole antenna with wideband circular polarization (CP) characteristics are designed and investigated. Planar, triangular prism, square prism, and hexagonal prism array arrangements are considered. Each prism face has a sub-array comprises 2 × 2 ME-dipole elements. Each sub-array has wide impedance matching of 73.7%, a maximum gain of 16.6 dBi, and CP bandwidth of 78.2%. It employs the plasma frequency of the ME-dipole antenna to control its radiation characteristics. Frequency-independent lumped element equivalent circuit is constructed for a single antenna element. It is used to represent the antenna input impedance at different plasma electron densities with fixed physical structure. The proposed equivalent circuit comprises a single series section used for matching enhancement with feeder circuit, and three parallel tuned circuits corresponding to the three resonance frequencies in the input impedance. The best values of the equivalent circuit elements are computed using the particle swarm optimization (PSO) technique. Different array arrangements, planar, triangular, square, and hexagonal prism are designed to create single or multiple beams in different directions. An electronic beam switching is achieved by tuning in the plasma inside the ME-dipole in the desired direction. The radiation characteristics are analyzed and investigated using the finite integration technique (FIT).

     

Effects of azadirachtin/Neemazal on different stages and adult life table parameters of Trichogramma cacoeciae (Hymenoptera: Trichogrammatidae)

The effects of azadirachtin/Neemazal on adults, emergence, and life table parameters of Trichogramma cacoeciae Marchal were studied. The adults were exposed to fresh residues of the insecticide applied on glass plates. Based on the dose-response study, the LC50 value was 1330 ppm or 13.3 microg (AI)/ml. The effect of Neemazal on three developmental stages of the parasitoid was tested by dipping parasitized Sitotroga cerealella (Olivier) and Cydia pomonella (L.) eggs at the field-recommended concentration 3, 6, and 9 d after parasitization corresponding to larval, prepupal, and pupal stages. The emergence of adult parasitoids was adversely affected in both hosts, but the adverse effect was more in S. cerealella eggs compared with C. pomonella. The adult emergence was reduced by 73.3 and 33.76% in Sitotroga and Cydia eggs compared with controls, respectively. Longevity and progeny production of the emergent adults did not differ significantly from control. Neemazal affected stable population parameters (r(m), T, and DT) significantly. The intrinsic rate of increase for the control and Neemazal-exposed populations was 0.340 and 0.335 female offspring per female per day, respectively. Because some of postemergence life table parameters of adults were significantly reduced by the insecticide treatment, emergence rate of the parasitoid from treated eggs is not an adequate measure of ecological selectivity, and field studies are needed to determine the actual impact of neem on T. cacoeciae.     

Applications of forensic chemistry to environmental work

Recent trends in environmental remediation have increasingly employed the use of environmental chemistry techniques to decipher the source(s) and fate of the contaminants and, in some cases, to determine their age or apportion them to sources. An extensive database of pyrogenic and petrogenic 'chemical fingerprints' has been constructed by the Gas Technology Institute (GTI) and META Environmental, Inc. using gas chromatography coupled with a flame ionization detector (GC/FID) or with a mass spectrometer (GC/MS). The use of these chemical fingerprinting techniques have been highly successful in discerning wastes from wholly different sources as well as among Manufactured Gas Plant (MGP)-type wastes from different plant operations. However, these techniques have been limited when low-level polycyclic aromatic hydrocarbon (PAH) discernment is required. Specifically, these techniques often do not provide data with sufficient conclusive discriminating power between the 'urban background'PAH sources and those from MGP-operations, which is pertinent for meeting low-level, stringent site-cleanup standards. GTI has been developing a new analytical method for the measurement of 'urban background' PAH contamination. This method measures the compound-specific isotope ratio (CSIR) carbon with a GC/IRMS (isotope ratio mass spectrometer). The GC/IRMS technique is a relatively new analytical tool that has great potential as an environmental forensic method at former MGP sites. This paper focuses on the applications of both chemical and isotopic analysis of samples to discern PAH contamination in the environment.     

Protective role of nitric oxide against arsenic-induced damages in germinating mung bean seeds

Nitric oxide (NO) is a bioactive gaseous, multifunctional molecule playing a central role and mediating a variety of physiological processes and responses to biotic and abiotic stresses including heavy metals. The present study investigated whether NO applied exogenously as sodium nitroprusside (SNP) has a protective role against arsenic (As) toxicity (applied as sodium arsenate) in Vigna radiata (mung bean) germinating seeds. Treatment with 75???M SNP significantly improved mung bean seed germination, growth, and decreased the As-accumulation. Furthermore, As-induced oxidative stress measured in terms of malondialdehyde and H₂O₂ contents was lesser upon supplementation of SNP indicating a reactive oxygen species scavenging activity of NO. In addition, supplementation of SNP markedly decreased the activity of superoxide dismutase and stimulated catalase, ??-amylase, protease and slightly changed the H⁺-ATPase activity.     

Natural variation in the fast phase of chlorophyll a fluorescence induction curve (OJIP) in a global rice minicore panel

Photosynthesis Research - Photosynthesis can be probed through Chlorophyll a fluorescence induction (FI), which provides detailed insight into the electron transfer process in Photosystem II, and...     

Genetic mapping of the early responses to salt stress in Arabidopsis thaliana

Salt stress decreases plant growth prior to significant ion accumulation in the shoot. However, the processes underlying this rapid reduction in growth are still unknown. To understand the changes in salt stress responses through time and at multiple physiological levels, examining different plant processes within a single set-up is required. Recent advances in phenotyping has allowed the image-based estimation of plant growth, morphology, colour and photosynthetic activity. In this study, we examined the salt stress-induced responses of 191 Arabidopsis accessions from 1 h to 7 days after treatment using high-throughput phenotyping. Multivariate analyses and machine learning algorithms identified that quantum yield measured in the light-adapted state (F_v′/F_m′) greatly affected growth maintenance in the early phase of salt stress, whereas the maximum quantum yield (QY_max) was crucial at a later stage. In addition, our genome-wide association study (GWAS) identified 770 loci that were specific to salt stress, in which two loci associated with QY_max and F_v′/F_m′ were selected for validation using T-DNA insertion lines. We characterized an unknown protein kinase found in the QY_max locus that reduced photosynthetic efficiency and growth maintenance under salt stress. Understanding the molecular context of the candidate genes identified will provide valuable insights into the early plant responses to salt stress. Furthermore, our work incorporates high-throughput phenotyping, multivariate analyses and GWAS, uncovering details of temporal stress responses and identifying associations across different traits and time points, which are likely to constitute the genetic components of salinity tolerance.     

Toll-like receptor 2 induced angiogenesis and invasion is mediated through the Tie2 signalling pathway in rheumatoid arthritis

Background

Angiogenesis is a critical early event in inflammatory arthritis, facilitating leukocyte migration into the synovium resulting in invasion and destruction of articular cartilage and bone. This study investigates the effect of TLR2 on angiogenesis, EC adhesion and invasion using microvascular endothelial cells and RA whole tissue synovial explants ex-vivo.

Methods

Microvascular endothelial cells (HMVEC) and RA synovial explants ex vivo were cultured with the TLR2 ligand, Pam3CSK4 (1 µg/ml). Angiopoietin 2 (Ang2), Tie2 and TLR2 expression in RA synovial tissue was assessed by immunohistology. HMVEC tube formation was assessed using Matrigel matrix assays. Ang2 was measured by ELISA. ICAM-1 cell surface expression was assessed by flow cytometry. Cell migration was assessed by wound repair scratch assays. ECM invasion, MMP-2 and -9 expression were assessed using transwell invasion chambers and zymography. To examine if the angiopoietin/Tie2 signalling pathway mediates TLR2 induced EC tube formation, invasion and migration assays were performed in the presence of a specific neutralising anti-Tie2mAb (10 ug/ml) and matched IgG isotype control Ab (10 ug/ml).

Results

Ang2 and Tie2 were localised to RA synovial blood vessels, and TLR2 was localised to RA synovial blood vessels, sub-lining infiltrates and the lining layer. Pam3CSK4 significantly increased angiogenenic tube formation (p<0.05), and upregulated Ang2 production in HMVEC (p<0.05) and RA synovial explants (p<0.05). Pam3CSK4 induced cell surface expression of ICAM-1, from basal level of 149±54 (MFI) to 617±103 (p<0.01). TLR-2 activation induced an 8.8±2.8 fold increase in cell invasion compared to control (p<0.05). Pam3CSK4 also induced HMVEC cell migration and induced MMP-2 and -9 from RA synovial explants. Neutralisation of the Ang2 receptor, Tie2 significantly inhibited Pam3CSK4-induced EC tube formation and invasion (p<0.05).

Conclusion

TLR2 activation promotes angiogenesis, cell adhesion and invasion, effects that are in part mediated through the Tie2 signalling pathway, key mechanisms involved in the pathogenesis of RA.     

Effect of Nano-Fe as Feed Supplement on Growth Performance,Survival Rate,Blood Parameters and Immune Functions of the Stellate Sturgeon (Acipenser stellatus)

Russian Journal of Marine Biology - The present study is aimed to investigate the effects of iron nanoparticles (Fe-NPs) on growth performance, liver histopathology and some blood parameters of the...     

Detection of morphometric differentiation between isolated up- and downstream populations of Siah Mahi (<Emphasis Type="Italic">Capoeta capoeta gracilis</Emphasis>) (Pisces: Cyprinidae) in the Tajan River (Iran)

It has been postulated that the building of the Shahid-Rajaei dam on the Tajan River around 1995 has lead to the morphological divergence of Siah Mahi Capotes capoeta gracilis (Pisces) of up- and downstream populations due to the isolation. A 13-landmark morphometric truss network system was used to investigate the hypothesis. Univariate analysis of variance showed significant differences between the means of the two groups for 45 standardized morphometric measurements out of 78 characters studied. In linear discriminant function analysis (DFA), the overall assignment of individuals into their original groups was 87.6%. The proportion of individuals correctly classified into their original groups was 90.3% for upstream and 83.7% for downstream population. The principal component analysis (PCA) scatter plot of individual component scores between PC1 and PC2 showed 121 fish specimens grouped into two areas but with a relativity high degree of overlap between two populations. Clustering analysis based on Euclidean square distances among groups of centroids using an UPGMA resulted into two main clusters indicating two populations of C. c. gracilis. The present study indicated the presence of two morphologically different populations of C. c. gracilis in the Tajan River across the Shahid-Rajaei dam, probably due to their limited downstream dispersal and the elimination of upstream migration altogether, due the construction of the dam.