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Arsenic (As) is a toxic metalloid that is present in natural surroundings in many forms with severe consequences to sustainable agriculture and human health. Plant growth-promoting Rhizobia have been found involved in the induction of plant tolerance under various biotic and abiotic stresses. An endofungal Rhizobium species associated with arbuscular mycorrhizal fungi (AMF) Serendipita indica deploy beneficial role in the promotion of plant growth and tolerance against various biotic and abiotic stresses. In the current study, we have determined the role of endofungal Rhizobium species in protection of host plant growth under As stress. We observed that endofungal Rhizobium species strain Si001 tolerate AsV up to 25 mM and its inoculation enhances tomato seed germination and seedling growth. A hyper-colonization of Rhizobium species Si001 in tomato roots was observed under As stress and results in modulation of GSH and proline content with reduced ROS. Rhizobium species Si001 colonization in host plant recovered pigment contents (chlorophyll-a and chlorophyll-b up to 189.5% and 192%, respectively), photosynthesis (157%), and water use efficiency (166%) compared to As-treated plants. Interestingly, bacterial colonization results in 40% increased As accumulation in the root, while a reduction in As translocation from root to shoot up to 89% was observed as compared to As treated plants. In conclusion, endofungal Rhizobium species Si001 association with the host plant may improve plant health and tolerance against As stress with reduced As accumulation in the crop produce. [ABSTRACT FROM AUTHOR]

In the refining and chemical industry, distillation is one of the prime processes and is a multivariable control problem, which involves interaction amongst several control loops and exhibit dead time in the dynamic behavior. The analysis and controller design of processes inheriting dead time is a challenging task, and the presence of plant uncertainties and disturbances makes it challenging to exert quality control over time. In this paper, a template and bounds free approach is explored for the simultaneous synthesis of quantitative feedback theory (QFT) based robust controller and pre-filter for Wood and Berry distillation column with multiple time delays. This presented method simplifies the QFT controller synthesis for MIMO systems and eliminates the need of ' Schauder fixed point theory ' to express the m × m MIMO system into analogous m 2 MISO plants before the QFT controller synthesis. Using the presented approach, an optimal MIMO QFT controller and pre-filter are synthesized in a single step, which else conventionally follows a long sequential design process. In the presented approach, the QFT controller design problem has been posed as an optimization problem and is solved using genetic algorithm. The work has been compared with the work already reported in literature. The designed multivariate QFT controller efficiently mitigate the effect of parametric uncertainties, satisfy the design requirements in a very tight envelope, minimize the interaction amongst the control loops and offers improved the disturbance rejection. • Work explores a template and bounds free approach for the simultaneous synthesis of QFT controllers. • Presented method eliminates the need of ' Schauder fixed point theory ' for conventional MIMO QFT controller synthesis. • Designed MIMO QFT controller efficiently mitigate the parametric uncertainties and time delays. • Comparison of the proposed technique with the reported methods is also presented. [ABSTRACT FROM AUTHOR]

Two contrasting guar varieties [Cyamopsis tetragonoloba (L.) Taub.], RGC-1002—a better drought tolerant than RGC-936—a comparatively sensitive variety, were subjected to 8 days of water stress. The physiological characteristics of gas exchange, pigments and the spectral properties of the leaves were monitored and assessed. The guar variety, RGC-1002 exhibited higher relative water content (RWC) and biomass accumulation in water stress condition as compared to RGC-936. The RGC-1002 variety also showed a higher rate of photosynthesis, stomatal conductance, and lesser reduction in chlorophyll content as compared to RGC-936 variety. On the 8th day of drought, the leaf anthocyanin levels were also higher in RGC-1002 than RGC-936. Increased levels of anthocyanin result in decrease in absorption of light, and an increase in reflectance, and transmittance. The scattering coefficient of leaf spectra was significantly increased in RGC-936 than in RGC-1002 leaves; this is due to an increase in the size of intercellular air spaces and shrinkage of cells as a result of water loss. The leaf reflectance was also observed to be significantly increased in RGC-936 than in RGC-1002 leaves. The physiological and leaf optical observations substantiate that RGC-1002 was better adapted to water stress than RGC-936 variety. [ABSTRACT FROM AUTHOR]

Four contrasting varieties of guar, RGC-1002 and RGC-1038, drought tolerant, while, Sarada and RGC-936, drought sensitive, were monitored in watered and drought. The water status, phenolics, plant anatomy and transcript level of genes related to anatomical traits were assessed. The study aimed to decipher the anatomical adaptations of guar plants in response to water stress. The physiological determinants, relative water content (RWC), water potential (ψ), and leaf membrane damage, declined under drought in all four varieties although, the decrement was lesser in the tolerant varieties. Furthermore, the tolerant cultivars subjected to water stress recorded higher accumulation of total phenolic content, anthocyanin and lignin, which efficiently scavenge the reactive oxygen species. The results suggest that the cultivars RGC-1002 and RGC-1038 are better able to resist drought-induced oxidative stress than Sarada and RGC-936. Moreover, leaf, petiole, stem and root anatomical traits viz. size of epidermal cell, parenchyma, width of cortex layer, and diameter of xylem vessels were narrowed in all the varieties although, the decrement was lesser in the tolerant varieties under drought. The expression analysis of genes revealed that drought-tolerant varieties showed enhanced mechanical support for water conduction by up-regulation of genes, Phenylalanine ammonia-lyase1 (PAL1), cinnamate-4-hydroxylase (C4H), 4-coumarate-CoA ligase (4CL), cinnamoyl-CoA reductase (CCR), caffeoyl-CoA O-methyltransferase (CCOMT), and cinnamyl-alcohol dehydrogenase (CAD6) in water stress conditions. The alterations in physio-anatomical, biochemical and gene expression traits in tolerant guar varieties enabled them to maintain steady nutrient transport while reducing the risk of embolisms and increasing water-flow resistance for better survival in water stressed conditions. [Display omitted] • Drought increases membrane damage and caused electrolyte leakage. • Cell size of epidermis, cortex and xylem reduced in leaf, petiole, stem, root. • Drought increases accumulation of lignin, total phenolic content and anthocyanins. • Transcript level of lignin pathway genes upregulated during drought. [ABSTRACT FROM AUTHOR]

A buck converter is a step-down switching regulator. Buck convertors are being widely used in industrial applications that rely on regulated output voltage under fluctuating input voltage. A buck convertor works in the following modes: (a) current-controlled or (b) voltage-controlled mode. But these convertors manifest several nonlinearites because of the switching operation. Hence, in order to generate a quality output of the convertor, the design of a controller becomes crucial. In this paper, the synthesis of a QFT-based robust controller and prefilter has been carried out for an uncertain buck converter with varying input voltage and varying load. The controller synthesis problem has been posed as an optimization problem, and metaheuristic algorithms have been used for obtaining the optimal gains for the QFT controller and prefilter. By doing this, the QFT synthesis can be carried out in a single step instead of following the sequential classical QFT process on Nichols charts and the need for the generation of templates and bounds has be eliminated. The designed 2-degree-of-freedom QFT control system offers a robust behavior and efficiently handles the parametric uncertainties. The robustness of the designed controller has been confirmed through simulation results for large input voltage and load fluctuations. [ABSTRACT FROM AUTHOR]

A novel metamaterial (MTM) element for radome applications is presented in this paper, which shows negative permittivity and permeability characteristics at distinct frequency ranges. The MTM element is composed of tightly coupled Swastika-shaped conductors printed on both sides of the dielectric substrate. The electromagnetic (EM) analysis of the proposed structure is carried out using the full-wave method-based standard software package and then validated with the experimental results. The MTM structure is further modified by introducing shorting strips at its edges to improve bandpass FSS response with flat-top and sharp roll-off characteristics in microwave and millimeter-wave frequency regimes. In view of airborne radome application of MTM-FSS structure, a multilayered hemispherical radome is designed by embedding it in the mid-plane of the radome wall. The EM performance of the antenna–radome system is analyzed using 3-D ray tracing geometrical optics in conjunction with aperture integration method, incorporating the transmission characteristics of MTM-FSS-based radome wall using CST Microwave Studio. The MTM-FSS-based radome exhibits superior EM performance characteristics as compared to the conventional optimized monolithic radome over the frequency range of 8.5–10.3 GHz, with high transmission efficiency (~0.30) and minimal boresight error (~4 mrad) for the entire beam steering range. [ABSTRACT FROM AUTHOR]

A novel EM (electromagnetic) design of low observable antenna using active hybrid-element frequency selective surface (FSS) as ground plane is presented in this paper for stealth applications. The EM characteristics of active hybrid-element FSS structure are reconfigured from reflecting mode to transmitting mode and vice versa by switching ON and OFF the PIN diode at 10 GHz. In ON state of diode (reflection mode), the FSS structure shows extremely less transmission (<−40 dB), which corroborates its suitability for ground plane of antenna. In OFF state of diode (transmission mode), it exhibits bandpass response over the frequency range 9.3–10.7 GHz corresponding to very less power loss (<−0.42 dB). Further, a low observable microstrip patch antenna (MPA) is designed using proposed FSS structure as ground plane and its EM characteristics are studied using commercial software package. In ON state of diode, the FSS-based MPA is observed to perform as typical MPA and its out-of-band radar cross section (RCS) also reduces as well. In OFF state of diode, FSS-based antenna does not radiate while passes EM signal impinging on its structure in result reduces significantly in-band RCS (up to 15.8 dBmm 2 ) as compared to conventional MPA. Finally, a prototype active FSS-based antenna is fabricated and measured for proof-of-the concept. [ABSTRACT FROM AUTHOR]

Automation of the robust control system synthesis for uncertain systems is of great practical interest. In this paper, the loop shaping step for synthesizing quantitative feedback theory (QFT) based controller for a two-phase permanent magnet stepper motor (PMSM) has been automated using teaching learning-based optimization (TLBO) algorithm. The QFT controller design problem has been posed as an optimization problem and TLBO algorithm has been used to minimize the proposed cost function. This facilitates designing low-order fixed-structure controller, eliminates the need of manual loop shaping step on the Nichols charts, and prevents the overdesign of the controller. A performance comparison of the designed controller has been made with the classical PID tuning method of Ziegler-Nichols and QFT controller tuned using other optimization algorithms. The simulation results show that the designed QFT controller using TLBO offers robust stability, disturbance rejection, and proper reference tracking over a range of PMSM’s parametric uncertainties as compared to the classical design techniques. [ABSTRACT FROM AUTHOR]

Loop shaping is the prime step for synthesising Quantitative Feedback Theory (QFT) based robust controllers. The synthesised QFT controller assures performance robustness in presence of parametric plant uncertainties'. In this paper for automating the controller synthesis, loop-shaping problem has been posed as multi-objective optimization problem, which is solved using particle swarm optimization algorithm. The presented approach, explores a template and bounds free method for the automatic synthesis of fixed structure QFT controller for a highly uncertain pneumatic servo actuator system. The paper also explores the use of level diagrams for choosing the ideal solution from the Pareto optimal set. From the results obtained, the designed controller offers performance robustness over a range of plant's parametric uncertainty. [ABSTRACT FROM AUTHOR]

The Goods and Services Tax Act 1985 does not require foreign suppliers to collect goods and services tax (GST). In addition, private importers are not required to pay GST unless the value of an imported consignment exceeds a de minimis threshold. Domestic retailers are crying foul; in their view, failing to levy GST on imports below the threshold makes the prices of New Zealand firms uncompetitive compared to offshore firms. This, they claim, erodes tax revenue and damages the local economy. But is the threshold really as problematic as local retailers contend? If it is problematic, are there alternatives better than the current regime? This article investigates. The article consists of three parts: the first part reviews the history and operation of GST; the second part examines the problems of a de minimis threshold; and finally, in the third part, the article considers potential options for reform. [ABSTRACT FROM AUTHOR]

The coordination between phytohormones regulation, stomatal behaviour (stomatal index and opening/closing) and gas exchange are potent determinants of plant survival under drought stress. However, we found a knowledge gap in the mechanism regulating the fine-tuning of these features during drought. In order to address this we evaluated gas exchange, stomatal behaviour and endogenous phytohormones content in two cotton varieties (LRA-5166 and NBRI-67) differing in drought sensitivity during water deficit conditions. Variety specific differences were recorded in net photosynthesis rate (A), transpiration rate (E) and stomatal conductance (gs) with significantly less decrease in drought tolerant LRA-5166 than drought sensitive NBRI-67. The abscisic acid (ABA) accumulation was significantly increased in LRA-5166 while reduced in NBRI-67 under water deficit, which was accompanied by relatively less reduced 6-benzylaminopurine (6-BAP) level in LRA-5166 than NBRI-67. Thus, improved ABA/6-BAP ratio was observed in both the varieties of cotton. Critically, LRA-5166 has reduced stomatal index, aperture size and significantly higher A and intrinsic water use efficiency (WUEi), thus higher drought tolerance than NBRI-67. Furthermore, we found that endogenous ABA predominantly maintains the stomatal behaviour and regulates its physiology either by antagonizing 6-BAP or alone to coordinate with water deficit signals. Overall, our findings describe a new insight as to how drought modulates endogenous ABA and 6-BAP homeostasis in cotton leaf and the mechanism of stomatal regulation by ABA and 6-BAP in cotton. [ABSTRACT FROM AUTHOR]

SUMMARY: Small RNAs (sRNAs) such as microRNAs (miRNAs) and small interfering RNAs (siRNAs) are short 20–24‐nucleotide non‐coding RNAs. They are key regulators of gene expression in plants and other organisms. Several 22‐nucleotide miRNAs trigger biogenesis cascades of trans‐acting secondary siRNAs, which are involved in various developmental and stress responses. Here we show that Himalayan Arabidopsis thaliana accessions having natural mutations in the miR158 locus exhibit robust cascade silencing of the pentatricopeptide repeat (PPR)‐like locus. Furthermore, we show that these cascade sRNAs trigger tertiary silencing of a gene involved in transpiration and stomatal opening. The natural deletions or insertions in MIR158 led to improper processing of miR158 precursors, thereby blocking synthesis of mature miR158. Reduced miR158 levels led to increased levels of its target, a pseudo‐PPR gene that is targeted by tasiRNAs generated by the miR173 cascade in other accessions. Using sRNA datasets derived from Indian Himalayan accessions, as well as overexpression and knockout lines of miR158, we show that absence of miR158 led to buildup of pseudo‐PPR‐derived tertiary sRNAs. These tertiary sRNAs mediated robust silencing of a gene involved in stomatal closure in Himalayan accessions lacking miR158 expression. We functionally validated the tertiary phasiRNA that targets NHX2, which encodes a Na+‐K+/H+ antiporter protein, thereby regulating transpiration and stomatal conductance. Overall, we report the role of the miRNA–TAS–siRNA–pseudogene–tertiary phasiRNA–NHX2 pathway in plant adaptation. Significance Statement: A natural variant of the miR158 locus of west Himalayan Arabidopsis thaliana shows miRNA‐driven cleavage of a pseudogene, and abolished activity of the miRNA leads to tertiary phasiRNA biogenesis. One such phasiRNA targets a gene that regulates growth and development in A. thaliana. The present study describes negative regulation of phasiRNA biogenesis by a miRNA. [ABSTRACT FROM AUTHOR]

In this work, a polarization independent and wideband electromagnetic (EM) waves absorbing frequency selective surface (FSS) structure is presented. The unit cell of the proposed FSS consists of an assembly of cross arrow resonators with four SMD resistors mounted on it, to enhance the absorbance bandwidth. This unit cell also possesses a four‐fold symmetry which makes it polarization insensitive. The designed unit cell is compact with the length and width dimensions as 0.19λL × 0.19λL, and thickness of 0.13λL, where λL is the guided wavelength corresponding to the lowest operating frequency. The proposed absorber is theoretically and experimentally tested for its absorbance, cross‐polarization level, and radar cross section (RCS) characteristics. The computer‐aided simulation and practical measurements indicate that the proposed absorber offers more than 90% (with a fractional bandwidth of 93%) absorbance for normal incidence at 4.5–12.4 GHz frequency band. The cross‐polarization reflection coefficient analysis indicates that the proposed FSS configuration behaves as an absorber and not a polarization convertor. The input impedance plot, surface current distribution, and E‐field distribution of the unit cell were also analyzed and presented to understand the absorbance mechanism. The RCS of the proposed FSS is compared with the RCS of a reflective (metallic) sheet to analyze its suitability for practical applications (RCS reduction) within the working band. The 3D simulated and 2D calculated RCS results indicate that the proposed FSS is suitable for wideband EM wave absorber applications. [ABSTRACT FROM AUTHOR]

This article presents broadband, high gain, and highly efficient, leaky wave antenna for X‐band applications. The proposed leaky wave antenna consists of periodic unit cells created by a combination of modified asymmetric meander line slots and an array of metallic via. The proposed unit cell configuration work as a composite left hand‐right hand leaky wave transmission line and it is characterized using dispersion analysis. The simulated and measurement results indicate that the proposed antenna offers a wide bandwidth of 52.94% (*with stop band of 2.1%) and a large beam scanning range from −59° to 70° with a maximum measured gain of 13.1 dBi. [ABSTRACT FROM AUTHOR]

Unravelling the plants responses towards rising atmospheric [CO 2 ] have largely been explored in genetical and morpho-physiological contexts. However, epigenetic factors including DNA methylation which play critical roles in adaptation are largely unexplored. Here we investigated the methylome, transcriptome and morpho-physiological responses of the two Arabidopsis thaliana populations evolved at high (3400 m amsl) and low elevation (700 m amsl) zones to elevated [CO 2 ] (e[CO 2 ]). We show that depending on the origin of the population, there were local level variations in DNA methylation when exposed to e[CO 2 ], but global methyl cytosine (mC) content remained unchanged. Further, there was loss of methylation and more protein coding genes were differentially methylated than transposable elements and non-coding RNA genes, in both the populations but more so in the low elevation one. The differentially methylated genes of the two populations belonged to distinct functional categories. More genes related to methylation machinery were down-regulated in the high elevation population than the low elevation one. Although there was no correlation between methylation and gene expression at the global scale but a few genes exhibited methylation dependent expression level. Finally the hyper- and hypo-methylated status of a few genes due to e[CO 2 ] treatment were validated. Overall, our data suggested the two populations responded differently towards e[CO 2 ] with respect to methylome remodeling, phenotypic and molecular plasticity. However, methylome remodeling and molecular plasticity were more prominent in the low elevation population. Understanding the evolution of epigenetic response towards e[CO 2 ] may help in future crop improvement strategies. • Elevated CO 2 affects DNA methylation remodeling in Arabidopsis thaliana depending on origin of the population. • Methylome remodeling and molecular plasticity of the low elevation population were more than the higher elevation one. • More protein coding genes were differentially methylated in response to elevated CO 2. • Elevated CO 2 induced global gene expression and methylation is not co-linear. [ABSTRACT FROM AUTHOR]

Metallothioneins (MTs) are diverse class of cysteine-rich proteins having metal-chelation properties. The role of MTs has been demonstrated in different abiotic stresses and MTs have been designated as biomolecular stress markers. Chickpea is an important legume crop supplying proteins to humans, as well as acting as great soil-binders along with nitrogen-fixation capability. The present research deals with the development of transgenic chickpea overexpressing metallothionein type-1 (CarMT1) gene for analyzing its role in stress tolerance against drought and heavy metals. The overexpression construct was designed using binary expression vector, pBI121 and transformed in chickpea desi cultivar, Pusa-362 for functional validation by using sonication-assisted Agrobacterium -mediated transformation. The results indicated high transcript levels under the drought (22-folds) and changes in physiological (photosynthesis rate, transpiration rate, stomatal conductance, water-use efficiency) and biochemical (antioxidant enzymes and compatible solutes) parameters suggesting stress-mitigating roles of CarMT1. The transgenic seeds were evaluated for heavy metal stress adaptation that resulted in better seed survival efficiency under different heavy metal stresses. The results indicated beneficial roles of MT gene in transgenic lines of chickpea in presence of different abiotic stresses, which could pave the way for multi-stress tolerant crop development. A schematic representation of working of MT gene in response to drought stress in transgenic chickpea plants. [Display omitted] • CarMT1 gene over-expressed in chickpea indicates drought and heavy metal stress enduring roles. • Transgenic plants were better in seed germination and root growth. • Physio-biochemical and molecular characterization reported stress adaptive roles. • Transgenic plants resulted up to 22-fold change in expression in comparison to control. [ABSTRACT FROM AUTHOR]

Arsenic (As) considered as one of the hazardous metalloid that hampers various physiological activities in rice. To study the mechanism of As tolerance in rice, one differentially expressed tau class glutathione-S-transferase (OsGSTU5) has been selected and transgenic rice plants with knockdown (KD) and overexpressing (OE) OsGSTU5 were generated. Our results suggested that KD lines became less tolerant to As stress than WT plants, while OE lines showed enhanced tolerance to As. Under As toxicity, OE and KD lines showed enhanced and reduced antioxidant activities such as, SOD, PRX and catalase, respectively indicating its role in ROS homeostasis. In addition, higher malondialdehyde content, poor photosynthetic parameters and higher reactive oxygen species (ROS) in KD plant, suggests that knockdown of OsGSTU5 renders KD plants more susceptible to oxidative damage. Also, the relative expression profile of various transporters such as OsABCC1 (As sequestration), Lsi2 and Lsi6 (As translocaters) and GSH dependent activity of GSTU5 suggests that GSTU5 might help in chelation of As with GSH and sequester it into the root vacuole using OsABCC1 transporter and thus limits the upward translocation of As towards shoot. This study suggests the importance of GSTU5 as a good target to improve the As tolerance in rice [Display omitted] • OsGSTU5 is upregulated in rice under Arsenic (As) stress. • High expressing OsGSTU5 lines showed tolerance under As toxicity. • OsGSTU5 sequester As in vacuoles of the root through OsABCC1 vacuolar transporter. • OsGSTU5 maintains the ROS homeostasis, physiological and biochemical activities. [ABSTRACT FROM AUTHOR]

• Peppermint based nanoemulsion has been synthesized by high energy sonication method. • 1% dose of PNE was able to inhibit the growth of A. solani. • 1% PNE reduce the disease severity caused by A. solani in tomato up to 87.5%. • PNE modulates plant physiology at biochemical, morphological, gene expression level. Early blight, caused by Alternaria solani is one of the most devastating disease affecting to the Solanum lycopersicum (tomato), reducing its productivity by 80%. The present study illustrates the synthesis of nanoemulsion using peppermint oil for potent antimicrobial activity against A. solani. A peppermint oil based nanoemulsion (PNE) was synthesized which was further characterized by Dynamic Light Scattering and Transmission Electron Microscopy. The nano-droplets present in nanoemulsion were spherical in shape with average size <100 nm. In-vitro antimicrobial activity of PNE was examined against A. solani with the carbendazim as positive control. A green-house study was performed to evaluate the antimicrobial efficacy and plant immunity developed by nanoemulsion as well as compared with carbendazim, chemical fungicide. PNE was much competent to reduce the disease severity up to 68.7% at 14th day and 87.5% at 21st day respectively. Physiological modulation was showed in tomato plants against A. solani, they were confirmed by measured the physical parameters, plant physiology, changes in leaf morphology and stress responses. A significant changes were found in proline and lipid peroxidation content in infected plants whereas nanoemulsion treated infected plants was able to cope-up from stress condition. Physical parameters and Scanning Electron Microscopy (SEM) analysis also revealed the similar observations. A reduced photosynthesis rate and transpiration rate were found in diseased plants as compared to other treatments, although stomatal conductance was not much affected. Defence responsive gene expression also up-regulated in PNE treated diseased plants than pathogen alone. Thus, the current study demonstrated the peppermint oil based nanoemulsion was more efficacious than chemical fungicide to early blight disease management in Solanum lycopersicum. [ABSTRACT FROM AUTHOR]