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Mangroves are Earth's most active and diversified saline wetlands, which play an essential role in protecting coastal communities from storm surge, cyclonic winds, tsunami, and tidal waves. Space-borne satellite data provide vital information for monitoring mangrove and retrieving health-related parameters. The objective of this study is to map and model biophysical and biochemical parameters of mangrove forests over the Bhitarkanika reserve forest located on the eastern coast of Odisha. The present study has employed Sentinel–2A sensor's red-edge bands to derive both the aforementioned parameters. Furthermore, the near-proximal sensor (NPS) data were integrated with satellite data for mapping leaf chlorophyll and nitrogen contents with the help of an empirical model. The key findings indicate that EVI (Enhanced Vegetation Index) and measured leaf chlorophyll were significantly and positively correlated (R2 = 0.78). EVI showed a stronger relationship with foliage pigments, such as leaf chlorophyll and nitrogen. Leaf area index (LAI) of mangrove ranged between 1 and 4, with healthy dense mangrove depicted LAI more than 2.5. Leaf chlorophyll content for dense mangrove forests showed between 40 and 90 μg/cm2 as estimated from satellite-based (i.e. NAOC index) and empirical model. However, the NAOC (Normalized Area Over reflectance Curve) index has relatively overestimated the chlorophyll. A similar pattern was also obtained for leaf nitrogen. Nevertheless, integrating both satellite and handheld NPS instruments has provided a robust and dynamic way to monitor mangrove forests' health conditions. Satellite-derived biophysical and biochemical parameters offer vital information on mangrove, which could be crucial towards conservation, plantation, and mangrove management.

Multiphoton imaging, a highly effective diagnostic technique, has recently gained widespread attention for early-stage cancer detection. Tremendous efforts have been dedicated to explore various types of exogenous contrast agents for improved signal-to-noise ratio of multiphoton imaging. Indocyanine green (ICG), the only U. S. FDA approved near-infrared chromophore, has been recently used as an exogenous contrast agent for two-photon bioimaging. Despite its great potential applications in clinical settings, the conventional delivery method of ICG has limited applications due to its poor cellular uptake and optical stability in its free form. Herein, we report the effect of nanoencapsulation of ICG on two-photon bioimaging. For this study, ICG was encapsulated within poly-l-arginine (PLA) based nanoparticles for the first time. These nanoparticles were found to be biocompatible and biodegradable as the major constituents were salts and PLA. These nanoparticles were spherical with a mean diameter of ∼61 nm and exhibit higher photostability than free ICG. Additionally, nanoencapsulated ICG treated cells show enhanced contrast for two-photon bioimaging in comparison with its free form. In summary, nanoencapsulated ICG could serve as an exogenous chromophore for multiphoton imaging, which shows excellent delivery efficacy.

Many bacterivorous and parasitic nematodes secrete signaling molecules called ascarosides that play a central role regulating their behavior and development. Combining stable-isotope labeling and mass spectrometry-based comparative metabolomics, here we show that ascarosides are taken up from the environment and metabolized by a wide range of phyla, including plants, fungi, bacteria, and mammals, as well as nematodes. In most tested eukaryotes and some bacteria, ascarosides are metabolized into derivatives with shortened fatty acid side chains, analogous to ascaroside biosynthesis in nematodes. In plants and C. elegans, labeled ascarosides were additionally integrated into larger, modular metabolites, and use of different ascaroside stereoisomers revealed the stereospecificity of their biosynthesis. The finding that nematodes extensively metabolize ascarosides taken up from the environment suggests that pheromone editing may play a role in conspecific and interspecific interactions. Moreover, our results indicate that plants, animals, and microorganisms may interact with associated nematodes via manipulation of ascaroside signaling.

We report on a multi-wavelength analysis of the 26 January 2014 solar eruption involving a coronal mass ejection (CME) and a Type-II radio burst, performed by combining data from various space-and ground-based instruments. An increasing standoff distance with height shows the presence of a strong shock, which further manifests itself in the continuation of the metric Type-II burst into the decameter-hectometric (DH) domain. A plot of speed versus position angle (PA) shows different points on the CME leading edge travelled with different speeds. From the starting frequency of the Type-II burst and white-light data, we find that the shock signature producing the Type-II burst might be coming from the flanks of the CME. Measuring the speeds of the CME flanks, we find the southern flank to be at a higher speed than the northern flank; further the radio contours from Type-II imaging data showed that the burst source was coming from the southern flank of the CME. From the standoff distance at the CME nose, we find that the local Alfven speed is close to the white-light shock speed, thus causing the Mach number to be small there. Also, the presence of a streamer near the southern flank appears to have provided additional favorable conditions for the generation of shock-associated radio emission. These results provide conclusive evidence that the Type-II emission could originate from the flanks of the CME, which in our study is from the the southern flank of the CME., 19 pages, 7 Figures, 1 table ; Accepted for publication in Solar Physics

We report observations of thermal emission from the frontal structure of a coronal mass ejection (CME) using data obtained with the Gauribidanur RAdioheliograPH (GRAPH) simultaneously at 80 MHz and 53 MHz on 2016 May 1. The CME was due to activity on the far-side of the Sun, but near its limb. No non-thermal radio burst activity were noticed. This provided an opportunity to observe the faint thermal radio emission from the CME, and hence directly estimate the electron density, mass, and magnetic field strength of the plasma entrained in the CME. Considering that CMEs are mostly observed only in whitelight and reports on their plasma characteristics are also limited, the rare direct radio observations of thermal emission from a CME and independent diagnosis of its plasma parameters are important measurements in the field of CME physics., Comment: 15 pages, 4 figures, accepted for publication in Geophysical Research Letters

Microorganisms and nematodes in the rhizosphere profoundly impact plant health, and small-molecule signaling is presumed to play a central role in plant rhizosphere interactions. However, the nature of the signals and underlying mechanisms are poorly understood. Here we show that the ascaroside ascr#18, a pheromone secreted by plant-parasitic nematodes, is metabolized by plants to generate chemical signals that repel nematodes and reduce infection. Comparative metabolomics of plant tissues and excretions revealed that ascr#18 is converted into shorter side-chained ascarosides that confer repellency. An Arabidopsis mutant defective in two peroxisomal acyl-CoA oxidases does not metabolize ascr#18 and does not repel nematodes, indicating that plants, like nematodes, employ conserved peroxisomal β-oxidation to edit ascarosides and change their message. Our results suggest that plant-editing of nematode pheromones serves as a defense mechanism that acts in parallel to conventional pattern-triggered immunity, demonstrating that plants may actively manipulate chemical signaling of soil organisms., Small molecules in the rhizosphere regulate interactions between plants and other organisms. Here the authors show that an ascaroside pheromone secreted by plant-parasitic nematodes is converted by host plant peroxisomal β-oxidation into shorter side-chained ascarosides that repel nematodes.

We carried out a statistical study of the `quiet' solar corona during the descending phase of the sunspot cycle 24 (i.e. 2015 January - 2019 May) using data obtained with the Gauribidanur RAdioheliograPH (GRAPH) at 53 MHz and 80 MHz simultaneously. Our results show that the equatorial (east-west) diameters of the solar corona at the above two frequencies shrunk steadily. The decrease was found to be due to a gradual reduction in the coronal electron density ($N_{e}$). Independent estimates of $N_{e}$ in the equatorial region of the `background' corona using white-light coronagraph observations indicate a decline consistent with our findings., Comment: Accepted for publication in Geophysical Research Letters

Pneumonia is an acute lung infection that takes life of many young children in developing countries. Early stage (red hepatization) detection of pneumonia would be pragmatic to control mortality rate. Detection of this disease at early stages demands the knowledge of pathology, making it difficult to screen noninvasively. We propose photoacoustic spectral response (PASR), a noninvasive elasticity-dependent technique for early stage pneumonia detection. We report the quantitative red hepatization detection of pneumonia through median frequency, spectral energy, and variance. Significant contrast in spectral parameters due to change in sample elasticity is found. The tissue-mimicking phantom study illustrates a 39% increase in median frequency for 1.5 times the change in density. On applying to formalin-fixed pneumonia-affected goat lungs, it provides a distinct change in spectral parameters between pneumonia affected areas and normal lungs. The obtained PASR results were found to be highly correlating to standard histopathology. The proposed technique therefore has potential to be a regular diagnostic tool for early pneumonia detection.

This study aimed to develop magnetic Fe3O4/sugarcane bagasse activated carbon composite for the adsorption of arsenic (III) from aqueous solutions. Activated carbon (AC) was prepared from sugarcane bagasse by chemical activation using H3PO4 as an activating agent at 400 &deg, C. To enhance adsorption capacity for arsenic, the resultant AC was composited with Fe3O4 particles by facile one-pot hydrothermal treatment. This method involves mixing the AC with aqueous solution of iron (II) chloride tetrahydrate, polyvinyl pyrrolidone (PVP), and ethanol. Batch adsorption experiments were conducted for the adsorption of As (III) onto the composite. The effects of pH, adsorbent dosage, and contact time on the arsenic adsorption were studied. The result showed that the composite could remove the arsenic from the water far more effectively than the plain AC. The highest percentage of arsenic removal was found at pH at 8, adsorbent dose of 1.8 g/L, and contact time of 60 min. Langmuir and Freundlich adsorption isotherm was used to analyze the equilibrium experimental data. Langmuir model showed the best fit compared to the Freundlich model with a maximal capacity of 6.69 mg/g. These findings indicated that magnetic Fe3O4/sugarcane bagasse AC composite could be potentially applied for adsorptive removal of arsenic (III) from aqueous solutions.

Context. Coronal mass ejections (CMEs) are large eruptions of magnetised plasma from the Sun that are often accompanied by solar radio bursts produced by accelerated electrons. Aims. A powerful source for accelerating electron beams are CME-driven shocks, however, there are other mechanisms capable of accelerating electrons during a CME eruption. So far, studies have relied on the traditional classification of solar radio bursts into five groups (Type I-V) based mainly on their shapes and characteristics in dynamic spectra. Here, we aim to determine the origin of moving radio bursts associated with a CME that do not fit into the present classification of the solar radio emission. Methods. By using radio imaging from the Nan\c{c}ay Radioheliograph, combined with observations from the Solar Dynamics Observatory, Solar and Heliospheric Observatory, and Solar Terrestrial Relations Observatory spacecraft, we investigate the moving radio bursts accompanying two subsequent CMEs on 22 May 2013. We use three-dimensional reconstructions of the two associated CME eruptions to show the possible origin of the observed radio emission. Results. We identified three moving radio bursts at unusually high altitudes in the corona that are located at the northern CME flank and move outwards synchronously with the CME. The radio bursts correspond to fine-structured emission in dynamic spectra with durations of ~1 s, and they may show forward or reverse frequency drifts. Since the CME expands closely following an earlier CME, a low coronal CME-CME interaction is likely responsible for the observed radio emission., Comment: 14 pages, 13 figures

We estimated the coronal magnetic field strength ($B$) during the 23 July 2016 coronal mass ejection (CME) event using i) the flux rope structure of the CME in the whitelight coronagraph images and ii) the band splitting in the associated type {\sc II} burst. No models were assumed for the coronal electron density ($N(r)$) used in the estimation.The results obtained using the above two independent methods correspond to different heliocentric distances ($r$) in the range $\approx$\,2.5\,--\,4.5$\rm R_{\odot}$, but they show excellent consistency and could be fitted with a single power-law distribution of the type $B(r)=5.7r^{-2.6}$ \textrm{G}, which is applicable in the aforementioned distance range. The power law index i.e. $-2.6$) is in good agreement with the results obtained in previous studies by different methods., 15 pages, 6 Figures

In recent years, two-photon fluorescence microscopy has gained significant interest in bioimaging. It allows the visualization of deeply buried inhomogeneities in tissues. The near-infrared (NIR) dyes are also used for deep tissue imaging. Indocyanine green (ICG) is the only U.S. Food and Drug Administration (FDA) approved exogenous contrast agent in the NIR region for clinical applications. However, despite its potential candidature, it had never been used as a two-photon contrast agent for biomedical imaging applications. This letter provides an insight into the scope and application of the two-photon excitation property of ICG to the second excited singlet (S2 ) state in aqueous solution. Furthermore, in this work, we demonstrate the two-photon cellular imaging application of ICG using direct fluorescence emission from S2 state for the first time. Our results show that two-photon excitation to S2 state of ICG could be achieved with approximately 790 nm wavelength of femtosecond laser, which lies in well-known "tissue-optical window." This property would enable light to penetrate much deeper in the turbid medium such as biological tissues. Thus, ICG could be used as the first FDA approved NIR exogenous contrast agent for two-photon imaging. These findings can make remarkable influence on preclinical and clinical cell imaging.

Corona, the outermost region of the Sun, is believed to be present from a heliocentric distance of ~.01 R ʘ (where R ʘ is the radius of the solar photosphere)to more than 1 AU. Being highly tenuous plasma medium, it harbours large scale structures, as multi-frequency observations reveal. One such powerful solar phenomenon is Coronal Mass Ejections (CMEs), which has radio signatures as Type II bursts. Type II solar radio bursts are considered to originate from plasma waves excited by magnetohydrodynamic(MHD) shocks and converted into radio waves at the local plasma frequency and/or its harmonics. They are the direct diagnostic of MHD shocks in the solar atmosphere.

We estimated the coronal magnetic field strength ( $B$ ) during the 23 July 2016 coronal mass ejection (CME) event using i) the flux rope structure of the CME in the white-light coronagraph images and ii) the band-splitting in the associated type II burst. No models were assumed for the coronal electron density ( $N(r)$ ) we used in the estimation. The results obtained with these two independent methods correspond to different heliocentric distances ( $r$ ) in the range ${\approx}\,2.5\,\mbox{--}\,4.5~\mbox{R}_{\odot}$ , but they show excellent consistency and could be fit with a single power-law distribution of the type $B(r)=5.7r^{-2.6}~\mbox{G}$ , which is applicable in that distance range. The power-law index (i.e. −2.6) is in good agreement with the results obtained in previous studies by different methods.

Dispersive delays due to the Solar wind introduce excess noise in high-precision pulsar timing experiments, and must be removed in order to achieve the accuracy needed to detect, e.g., low-frequency gravitational waves. In current pulsar timing experiments, this delay is usually removed by approximating the electron density distribution in the Solar wind either as spherically symmetric, or with a two-phase model that describes the contributions from both high- and low-speed phases of the Solar wind. However, no dataset has previously been available to test the performance and limitations of these models over extended timescales and with sufficient sensitivity. Here we present the results of such a test with an optimal dataset of observations of pulsar J0034-0534, taken with the German stations of LOFAR. We conclude that the spherical approximation performs systematically better than the two-phase model at almost all angular distances, with a residual root-mean-square (rms) given by the two-phase model being up to 28% larger than the result obtained with the spherical approximation. Nevertheless, the spherical approximation remains insufficiently accurate in modelling the Solar-wind delay (especially within 20 degrees of angular distance from the Sun), as it leaves timing residuals with rms values that reach the equivalent of 0.3 microseconds at 1400 MHz. This is because a spherical model ignores the large daily variations in electron density observed in the Solar wind. In the short term, broadband observations or simultaneous observations at low frequencies are the most promising way forward to correct for Solar-wind induced delay variations., Accepted for publication in MNRAS. 17 pages, 13 figures

We report a solar coronal split-band type II radio burst that was observed on 2016 March 16 with the Gauribidanur Radio Spectro-Polarimeter (GRASP) in the frequency range $\approx$\,90\,-\,50 MHz, and the Gauribidanur RadioheliograPH (GRAPH) at two discrete frequencies, viz. 80 MHz and 53.3 MHz. Observations around the same epoch in extreme-ultraviolet (EUV) and white-light show that the above burst was associated with a flux rope structure and a coronal mass ejection (CME), respectively. The combined height-time plot generated using EUV, radio, and whitelight data suggest that the different observed features (i.e. the flux rope, type II burst and the CME) are all closely associated. We constructed an empirical model for the coronal electron density distribution ($N_{e}(r)$, where $r$ is the heliocentric distance) from the above set of observations themselves and used it to estimate the coronal magnetic field strength ($B$) over the range of $r$ values in which the respective events were observed. The $B$ values are consistent with each other. They vary as $B(r)\,=\,2.61 \times r^{-2.21}$ \textrm{G} in the range $r \approx$\,1.1\,-\,2.2$\rm R_{\odot}$. As far as we know, similar `direct' estimates of $B$ in the near-Sun corona without assuming a model for $N_{e}(r)$, and by combining co-temporal set of observations in two different regions (radio and whitelight) of the electromagnetic spectrum, have rarely been reported. Further, the present work is a novel attempt where the characteristics of a propagating EUV flux rope structure, considered to be the signature of a CME close the Sun, have been used to estimate $B(r)$ in the corresponding distance range., 11 pages, 8 figures, 3 tables; Accepted for publication in ApJ