Fresnel zone plate telescopes for X-ray imaging II: numerical simulations with parallel and diverging beams

We present the results of simulations of shadows cast by a zone plate telescope which may have one to four pairs of zone plates. From the shadows we reconstruct the images under various circumstances. We discuss physical basis of the resolution of the telescope and demonstrate this by our simulations. We allow the source to be at a finite distance (diverging beam) as well as at an infinite distance (parallel beam) and show that the resolution is worsened when the source is nearby. By reconstructing the zone plates in a way that both the zone plates subtend the same solid angles at the source, we obtain back high resolution even for sources at a finite distance. We present simulated results for the observation of the galactic center and show that the sources of varying intensities may be reconstructed with accuracy. Results of these simulations would be of immense use in interpreting the X-ray images from recently launched CORONAS-PHOTON satellite.Comment: 17 pages, 36 figures, Published in Experimental Astronom

Assessing Tolerance to Heavy-Metal Stress in Arabidopsis thaliana Seedlings

The deposited book chapter is a post-print version and has been submitted to peer review.The deposited book chapter version contains attached the supplementary materials within the pdf.This publication hasn't any creative commons license associated.The deposited book chapter is part of the book series: "Environmental Responses in Plants: Methods and Protocols" (pp.197-208) published by Springer.Heavy-metal soil contamination is one of the major abiotic stress factors that, by negatively affecting plant growth and development, severely limit agricultural productivity worldwide. Plants have evolved various tolerance and detoxification strategies in order to cope with heavy-metal toxicity while ensuring adequate supply of essential micronutrients at the whole-plant as well as cellular levels. Genetic studies in the model plant Arabidopsis thaliana have been instrumental in elucidating such mechanisms. The root assay constitutes a very powerful and simple method to assess heavy-metal stress tolerance in Arabidopsis seedlings. It allows the simultaneous determination of all the standard growth parameters affected by heavy-metal stress (primary root elongation, lateral root development, shoot biomass, and chlorophyll content) in a single experiment. Additionally, this protocol emphasizes the tips and tricks that become particularly useful when quantifying subtle alterations in tolerance to a given heavy-metal stress, when simultaneously pursuing a large number of plant lines, or when testing sensitivity to a wide range of heavy metals for a single line.Fundação para a Ciência e a Tecnologia grants: (EXPL/AGR-PRO/1013/2013, SFRH/BPD/44640/2008); GREEN-it "Bioresources for Sustainability": (UID/Multi/04551/2013).info:eu-repo/semantics/publishedVersio

Leukocytes Breach Endothelial Barriers by Insertion of Nuclear Lobes and Disassembly of Endothelial Actin Filaments

Israel Science Foundation (grant 87/12) Flight Attendant Medical Research Institute Foundation (FAMRI) (grant FAMRI032001_CoE), USA Minerva Foundation, Germany Wellcome Trust (grant 098291/Z/12/Z to S.N.

Instruments of RT-2 Experiment onboard CORONAS-PHOTON and their test and evaluation III: Coded Aperture Mask and Fresnel Zone Plates in RT-2/CZT Payload

Imaging in hard X-rays of any astrophysical source with high angular resolution is a challenging job. Shadow-casting technique is one of the most viable options for imaging in hard X-rays. We have used two different types of shadow-casters, namely, Coded Aperture Mask (CAM) and Fresnel Zone Plate (FZP) pair and two types of pixellated solid-state detectors, namely, CZT and CMOS in RT-2/CZT payload, the hard X-ray imaging instrument onboard the CORONAS-PHOTON satellite. In this paper, we present the results of simulations with different combinations of coders (CAM & FZP) and detectors that are employed in the RT-2/CZT payload. We discuss the possibility of detecting transient Solar flares with good angular resolution for various combinations. Simulated results are compared with laboratory experiments to verify the consistency of the designed configuration.Comment: 27 pages, 16 figures, Accepted for publication in Experimental Astronomy (in press

Comparison of in vitro regeneration efficiency of leaf explants in response to different cytokinins and assessment of genetic uniformity of regenerated plants of Solanum surattense Burm.f.

An efficient, genetically stable and rapid regeneration system via multiple shoot formation was developed for an endangered medicinal herb Solanum surattense. Leaves were cultured on MS medium supplemented with different concentration of cytokinins; 6-benzylaminopurine (BAP), kinetin (Kn), thiadiazuron (TDZ), zeatin and inorganic phosphate (iP) alone or in combinations. Among five cytokinins used, TDZ (0.1 mg/l) gave the maximum regeneration response (35 shoot buds per explant), with 100% regeneration efficiency. Comparative regeneration efficiency of cytokinins was in the following order: TDZ > zeatin > iP > BAP > Kn and the comparative ratio was 6:4:3:2:1. Highestfrequency of adventitious shoot bud induction (54 shoot buds per explant) was achieved on combination of TDZ (0.1 mg/l) and BAP (1 mg/l). Combinations of cytokinins were more effective for shoot bud regeneration as compared to cytokinin alone. Best root formation was observed on Murashige and Skoog (MS) medium supplemented with 1 mg/l indole-3-acetic acid (IBA). The rooted plantlets were hardened gradually and resulted in a production of more than 80% plantlets. Theefficiency of auxins for root organogenesis was in the following order: IBA > IAA > NAA > PAA. Genetic stability of regenerated plants was analyzed using random amplified polymorphic DNA (RAPD) markers.Keywords: Solanum surattense, adventitious shoot buds, genetic fidelity, random amplified polymorphic DNA, thiadiazuro

Bianchi Type-II String Cosmological Models in Normal Gauge for Lyra's Manifold with Constant Deceleration Parameter

The present study deals with a spatially homogeneous and anisotropic Bianchi-II cosmological models representing massive strings in normal gauge for Lyra's manifold by applying the variation law for generalized Hubble's parameter that yields a constant value of deceleration parameter. The variation law for Hubble's parameter generates two types of solutions for the average scale factor, one is of power-law type and other is of the exponential form. Using these two forms, Einstein's modified field equations are solved separately that correspond to expanding singular and non-singular models of the universe respectively. The energy-momentum tensor for such string as formulated by Letelier (1983) is used to construct massive string cosmological models for which we assume that the expansion ($\theta$) in the model is proportional to the component $\sigma^{1}_{~1}$ of the shear tensor $\sigma^{j}_{i}$. This condition leads to $A = (BC)^{m}$, where A, B and C are the metric coefficients and m is proportionality constant. Our models are in accelerating phase which is consistent to the recent observations. It has been found that the displacement vector $\beta$ behaves like cosmological term $\Lambda$ in the normal gauge treatment and the solutions are consistent with recent observations of SNe Ia. It has been found that massive strings dominate in the decelerating universe whereas strings dominate in the accelerating universe. Some physical and geometric behaviour of these models are also discussed.Comment: 24 pages, 10 figure

Differential expression of collectins in human placenta and role in inflammation during spontaneous Labor.

© 2014 Yadav et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Collectins, collagen-containing Ca2+ dependent C-type lectins and a class of secretory proteins including SP-A, SP-D and MBL, are integral to immunomodulation and innate immune defense. In the present study, we aimed to investigate their placental transcript synthesis, labor associated differential expression and localization at feto-maternal interface, and their functional implication in spontaneous labor. The study involved using feto-maternal interface (placental/decidual tissues) from two groups of healthy pregnant women at term (≥37 weeks of gestation), undergoing either elective C-section with no labor ('NLc' group, n = 5), or normal vaginal delivery with spontaneous labor ('SLv' group, n = 5). The immune function of SP-D, on term placental explants, was analyzed for cytokine profile using multiplexed cytokine array. SP-A, SP-D and MBL transcripts were observed in the term placenta. The 'SLv' group showed significant up-regulation of SP-D (p = 0.001), and down-regulation of SP-A (p = 0.005), transcripts and protein compared to the 'NLc' group. Significant increase in 43 kDa and 50 kDa SP-D forms in placental and decidual tissues was associated with the spontaneous labor (p<0.05). In addition, the MMP-9-cleaved form of SP-D (25 kDa) was significantly higher in the placentae of 'SLv' group compared to the 'NLc' group (p = 0.002). Labor associated cytokines IL-1α, IL-1β, IL-6, IL-8, IL-10, TNF-α and MCP-1 showed significant increase (p<0.05) in a dose dependent manner in the placental explants treated with nSP-D and rhSP-D. In conclusion, the study emphasizes that SP-A and SP-D proteins associate with the spontaneous labor and SP-D plausibly contributes to the pro-inflammatory immune milieu of feto-maternal tissues.Funding provided by BT/PR15227/BRB/10/906/2011) Department of Biotechnology (DBT), Government of India http://dbtindia.nic.in/index.asp (TM) and Indian Council of Medical Research (ICMR) Junior Research Fellowship (JRF)/Senior Research Fellowship (SRF), Government of India, www.icmr.nic.in (AKY)

Oxidant and solvent stable alkaline protease from Aspergillus flavus and its characterization

The increase in agricultural practices has necessitated the judicious use of agricultural wastes into value added products. In this study, an  extracellular, organic solvent and oxidant stable, serine protease wasproduced by Aspergillus flavus MTCC 9952 under solid state fermentation. Maximum protease yield was obtained when the strain was grown under wheat bran and corn cob mixture (1:1) incubated for 48 h at pH 9.0 and temperature 37°C with 50% of initial moisture content. The partially purified enzyme showed wide range of pH optima (8.0-12.0) and pH stability (7.0-12.0), whereas, optimum temperature was 40°C and was stable over a wide range of temperature 30-45°C. The protease was extremely stable towards several organic solvents. The enzyme retained 80% of its original activity in the presence of non ionic and ionic surfactants and 100% with 10% H2O2 after 1 h of incubation at 30°C. In addition, the enzyme showed excellent compatibility with some commercial powder detergents. The compatibility of our protease with several detergents, oxidants and organic solvents suggests its possible use in detergent industry and peptide synthesis.Key words: Alkaline protease, solid state fermentation, PMSF, organic solvent

Control of sulphide during anaerobic treatment of S-containing wastewaters by adding limited amounts of oxygen or nitrate

Sulphide generated during anaerobic treatment of S-containing wastewaters represents an environmental problem. Adding limited amounts of oxygen or nitrate (or nitrite) to biologically (or chemically) oxidise sulphide forms a simple process level strategy to control this problem. This short review evaluates the feasibility and limitations of this strategy on the basis of the results of bioreactor studies.Sulphide generated during anaerobic treatment of S-containing wastewaters represents an environmental problem. Adding limited amounts of oxygen or nitrate (or nitrite) to biologically (or chemically) oxidise sulphide forms a simple process level strategy to control this problem. This short review evaluates the feasibility and limitations of this strategy on the basis of the results of bioreactor studies.Spanish Ministry of Education and Science; AEA Technology Environment; Nova Energie; The Swedish Gas Centre; University of Southern Denmark

Effective battery charging system using step voltage and step duty size-based MPPT controller for solar PV system

\ua9 2023 The Author(s). Solar energy is an excellent source of renewable energy, despite its intermittent nature that can pose a challenge. To meet load demand, a converter is required to integrate the system. The converter acts based on control signals from the controller, which is trained according to the end demand and availability of Sun Irradiance. This paper utilizes the Incremental Conductance (IC) and Perturb and Observe (P&amp;O) algorithms, which are widely accepted in the industry and easy to implement. This study aims to design and compare a Step Voltage (SV) controller and a Step-Duty (SD) Maximum Point Tracking (MPPT) IC controller-based DC to DC boost converter. The paper compares the performance of SV and SD controller-based DC to DC boost converters under different environmental conditions, evaluates the system\u27s effectiveness by comparing the oscillations in load power for both conditions and discusses the impact of battery charging on the Load. The system performance is tested using MATLAB Simulink/coding, considering the Indian solar radiation intensity (SRI) scenario and temperature variations. Overall, this study provides a comprehensive analysis of the performance of the proposed system, which can contribute to the development and optimization of solar energy systems in various applications. From the comparative analysis of IC SD, SV and P&amp;O SD, SV it is observed the performance of IC SD is superior. The impact of battery charging using IC SD controller on the load and MPPT point is also discussed