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Plant tissue culture is the primary, fundamental, and applied aspect of plant biology. It is an indispensable and valuable technique for investigating morphogenesis, embryogenesis, clonal propagation, crop improvements, generation of pathogen-free plants, gene transfer and expression, and the production of secondary metabolites. The extensive use of various nanoparticles (NPs) in fields such as cosmetics, energy, medicine, pharmaceuticals, electronics, agriculture, and biotechnology have demonstrated positive impacts in microbial decontamination, callus differentiation, organogenesis, somatic variations, biotransformation, cryopreservation, and enhanced synthesis of bioactive compounds. This review summarizes the current state of knowledge with regard to the use of nanoparticles in plant tissue culture, with a particular focus on the beneficial outcomes. The positive (beneficial) and negative (toxic) effects of engineered NPs in tissue culture medium, delivery of transgenes, NPs toxicity concerns, safety issues, and potential hazards arising from utilization of nanomaterials in agriculture through plant tissue culture are discussed in detail, along with the future prospects for these applications. In addition, the potential use of novel nanomaterials such as graphene, graphite, dendrimers, quantum dots, and carbon nanotubes as well as unique metal or metalloid NPs are proposed. Further, the potential mechanisms underlying NPs elicitation of tissue culture response in different applications are critically evaluated. The potential of these approaches in plant nanobiotechnology is only now becoming understood and it is clear that the role of these strategies in sustainably increasing crop production to combat global food security and safety in a changing climate will be significant. [Display omitted] • Inclusion of nanoparticles in tissue culture medium enhance sustenance for culturing otherwise hard to propagate plants. • This study presents an overview of nanoparticles as a novel elicitor in plant tissue culture applications and challenges. • The phytotoxic effects of nanoparticles at physiological, biochemical and molecular levels are highlighted. • Provided information will be beneficial for plant improvement and enhanced production of significant secondary metabolites. [ABSTRACT FROM AUTHOR]

Oxidative stress generates reactive oxygen species which causes cell damage of living organisms and are normally detoxified by antioxidants. Indirect reports signify the damages caused by reactive oxygen species and neutralized by antioxidant, but the direct evidence to confirm this hypothesis is still unclear. To validate our hypothesis, an attempt was made in a diazotrophic bacterium (Azotobacter chroococcum Avi2) as a biological system, and hydrogen peroxide (H 2 O 2) and ascorbic acid were used as oxidative stress and antioxidant supplement, respectively. Additionally, rice plant-growth attributes by Avi2 was also assessed under H 2 O 2 and ascorbic acid. Results indicated that higher concentration of H 2 O 2 (2.5 mM-4.5 mM) showed the complete mortality of Avi2, whereas one ppm ascorbic acid neutralized the effect of H 2 O 2. Turbidity, colony forming unit, DNA quantity, nifH gene abundance, indole acetic acid and ammonia productions were significantly (p < 0.5) increased by 11.93%, 17.29%, 19.80%, 74.77%, 71.89%, and 42.53%, respectively in Avi2-treated with 1.5 mM H 2 O 2 plus ascorbic acid compared to 1.5 mM H 2 O 2 alone. Superoxide dismutase was significantly (p < 0.5) increased by 60.85%, whereas catalase and ascorbate peroxidase activities were significantly (p < 0.05) decreased by 64.28% and 68.88% in Avi2-treated with 1.5 mM H 2 O 2 plus ascorbic acid compared to 1.5 mM H 2 O 2 alone. Germination percentage of three rice cultivars (FR13a, Naveen and Sahbhagi dhan) were significantly (p < 0.5) increased by 20%, 13.33%, and 4%, respectively in Avi2-treated with 0.6 mM H 2 O 2 plus ascorbic acid compared with uninoculated control. Overall, this study indicated that ascorbic acid formulation neutralizes the H 2 O 2 -oxidative stress and enhances the survivability and plant growth-promoting efficacy of A. chroococcum Avi2 and therefore, it may be used as an effective formulation of bio-inoculants in rice under oxidative stress. • Efficacy of Azotobacter chroococcum Avi2 was studied under H 2 O 2 stress and ascorbic acid. • Higher concentration of H 2 O 2 (2.5 mM–4.5 mM) showed a complete mortality of Avi2. • One ppm ascorbic acid neutralized the effect of H 2 O 2 (∼4.5 mM) and retrieved Avi2 growth. • Ascorbic acid increased the diazotrophic efficacy of Avi2 by 74.77% in 1.5 mM H 2 O 2. • Ascorbic acid enhanced the rice plant-growth attributes in Avi2-treated with 0.6 mM H 2 O 2. [ABSTRACT FROM AUTHOR]

• The conventional ceramic route successfully synthesized all the samples. • Jonscher power law was applied to the ac conductivity of all samples to study the conduction mechanism. • The conductivity spectrum of all samples follows Ghosh and Rolling scaling. • Kohlrausch-William-Watt function was applied to M ″ (f) to study the relaxation mechanism of samples. • Both the scaling behaviors reflected the temperature-independent conduction mechanism in the system. The mixed ionic and electronic conductor oxide with formula Sr 2-x La x SnO 4 (S2LS) within x ≤ 0.10 were synthesized via the conventional ceramic route and investigated. The structural analysis revealed the formation of single-phase materials with a tetragonal crystal structure. The presence of Sn in the form of Sn4+/Sn2+ ions and oxygen vacancies in the synthesized samples were investigated by X-ray photoelectron spectroscopy. The alternating current (AC) conductivity and modulus spectra of S2LS systems were obtained as functions of frequency and temperature and further scaled. The AC conductivity data were analyzed using Jonscher's power law (JPL) fitting to determine the hopping frequencies, DC conductivities, and power exponents. The obtained activation energy value suggests the dependence of conductivity primarily on the mobility of charge carriers. The conductivity spectra were analyzed using various formalisms, viz., Ghosh scaling and Rolling scaling, to understand the conduction mechanism. The scaling behaviors of AC conductivity and modulus spectra reflect the temperature-independent conduction mechanism of the system. [Display omitted] The following graph shows Rietveld refinement XRD pattern, high-resolution scanning electron micrograph, scaled conductivity and scaled modulus as a function of frequency at different temperatures. [ABSTRACT FROM AUTHOR]

Soil bacterial communities are considered as an essential member of the microbial community, contributing to soil health. Continuous application of chemical fertilizers alters the bacterial community structure (BCS) thereby disturbing the soil biogeochemical cycling. The present study highlights the 16S rRNA amplicon sequencing-based variation of BCS through Illumina-MiSeq ® in a 47 years old long-term fertilized paddy soil and its relation with grain yield (GY), straw biomass (SB) and various soil properties. The experiment comprising six treatments: control (no fertilizers), nitrogen (N), nitrogen + phosphorus (P) + potassium (K), farmyard manure (FYM), FYM + N and FYM + NPK. Data on rice crop performance indicated that GY and SB significantly ( p  ≤ 0.05) enhanced by 45.1%–49.3% and 36.9–39.4% in FYM + NPK compared to control. Relative abundance of bacterial phyla varied across inorganic and organic fertilizer treatments. Dominant phyla across all treatments were Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, and Firmicutes, accounting for about 80–85% of total operational taxonomic units (OTUs). N application alone over 47 years encouraged certain bacterial phyla (Firmicutes, Actinobacteria, and Nitrospira) while major (Proteobacteria, Acidobacteria and Cyanobacteria) and minor (Fibrobacteres, Spirochaetes, TM7 and GNO4) bacterial phyla were found to be suppressed compared to other treatments. Moreover, continuous use of chemical N in paddy soil, considerably suppressed some diazotrophs taxa Burkholderiales, Enterobacteriaceae, and other taxa Kaistobacter, Anaeromyxobacter, Bdellovibrio, and MND1. Redundancy analysis coupled with principal component analysis revealed that BCS was significantly influenced by soil pH and presence of higher nitrogen content. Interestingly, the highest proportion of bacterial OTUs was recorded in balanced fertilizer (NPK) (without FYM) and therefore, this result suggested for the first time that continuous application of NPK encouraged the beneficial bacterial community without compromising of GY and SB. Overall, the present study indicated that continuous application of N and NPK with or without FYM for more than four decades in paddy soil, encouraged certain BCS whereas, N application alone suppressed certain beneficial bacterial phyla, resulting in the alteration of soil biodiversity and rice productivity. [ABSTRACT FROM AUTHOR]

Diazotrophs are one of the most important microbial communities which play a key role in rhizosphere to enhance plant growth-promotion by supplying fixed nitrogen to the plants. The aim of present study was to analyze the frequency and diversity of diazotrophs in the rhizospheres of five genotypes of aromatic rice ( Oryza sativa cultivars Nua Kalajeera, Ketekijoha, Nua Desheri, Nua Chandan and Kala Namak) grown in ten years old long-term aromatic rice-rice (LARR) cropping system under sub-humid tropical condition. In this study, it was observed that very less frequency of active diazotrophs (0–14.28%) in the rhizosphere of aromatic rice genotypes based on polymerase chain reaction (PCR)-based nifH gene amplification, dot blot hybridization and acetylene reduction assay (ARA). The following five isolates (B10, B12, B29, BK16, NKR16) from rhizosphere of aromatic rice and the reference strain Azospirillum brasilence showed nifH amplification and positive signal for dot blot. None of these isolates showed positive in ARA test except A. brasilence . Basic local alighnment search tool (BLAST) homology of nifH sequences of B10, B12, B29, BK16 and NKR16 matched with Gluconoacetobacter diazotrophicus , Pseudomonas stutzeri , Klebsiella sp., Klebsiella pneumoniae and Sinorhizobium meliloti, respectively. Whereas, isolates B10, B12 and BK16 were identified as Bacillus cereus, Enterobacter sp., and Lysinibacillus sp., respectively based on 16S-rDNA sequencing. As per nifH sequences, these diazotrophs (B10, B12, B29, BK16, NKR16) fall under α and γ-proteobacter, whereas 16S-rDNA sequences revealed that they belonged to firmicutes and γ-proteobacter. Multiple sequence alignment of nifH gene sequences showed wider variation among diazotrophs, however 3D structure of NifH protein revealed the less diversity among isolates. Moreover, restriction digestion of 16S-rDNA using tetracutters ( MspI, MboI and HaeIII ) deciphered a unique pattern among small population of diazotrophs.The results of this finding provided an interesting data and novel information of diazotroph diversity in LARR cropping system. Finally, the present study indicated that the continuous application of high dose of inorganic nitrogenous fertilizers (nitrogen at the rate of 60 & 80 kg N ha −1 year −1 in wet and dry seasons, respectively) limit the frequency and diversity of rhizospheric diazotrophs in the LARR cropping system. [ABSTRACT FROM AUTHOR]

Soil microbial communities play an essential role in maintaining soil fertility and considered as ecological indicators to evaluate soil health. In the present study, long-term effects of organic and inorganic fertilizers on functional diversity of soil microbial communities, and their correlation with soil organic carbon, microbial biomass and activities, were observed under sub-humid tropical rice-rice cropping system. This experiment comprises six treatments viz . control (plots without application of chemical fertilizers and farm yard manure), nitrogen (N at the rate of 60 & 80 kg ha −1 in wet and dry seasons, respectively), nitrogen + phosphorus + potassium (NPK), farm yard manure (FYM), FYM + N and FYM + NPK. The results indicated that pH of the soil under the treatments decreased from its initial value, whereas total organic carbon increased in FYM-treated plots. Microbial biomass carbon and nitrogen in FYM + NPK were increased by 50.0 and 46.4%, respectively as compared to control treatment. Carbon and nitrogen mineralization; and soil enzyme activities were significantly ( p ≤ 0.05) higher in FYM + NPK over control. The average well color development (AWCD) values derived from Biolog ® eco-plates followed the order of FYM + N > FYM > FYM + NPK > NPK > N > Control. Shannon index was greater (p ≤ 0.05) in FYM-treated soil as compared to control and chemical treated soil. Principal component analysis (PCA) indicates a clear separation of the cluster of treatments with FYM application (FYM and FYM + NPK) and treatments without FYM (N and NPK). Shannon index was significantly correlated with available phosphorus ( p ≤ 0.002) and carbon mineralization ( p ≤ 0.015). Biplot analysis suggested that polymer and amino acid utilizing microbes were dominant, irrespective of all treatments. These results revealed that continuous application of nitrogen fertilizer alone has responded a shift in soil microbial community in the long run and decreased the functional diversity of microbes. However, application of FYM either alone, or in combination with chemical fertilizers, could restore soil fertility. Moreover, the information generated from this experiment though Biolog ® may be the first particularly with reference to the dominance of polymer and amino acid utilizing microbes, irrespective of treatments under long-term fertilized paddy soil. [ABSTRACT FROM AUTHOR]

Predicting bandgap is a crucial topic in materials informatics, however, it is still difficult when the available dataset is limited and unbalanced. Here, we applied a machine learning approach to construct a prediction model for transition metal dichalcogenides and oxides. Using an oversampling technique and atomistic feature engineering, we successfully constructed the machine learning model and analyzed the correlation with other physical properties. Furthermore, we also utilized the model to obtain a compressive sensing model based on physical quantities for analytic interpretation and quick prediction. • Machine learning model for bandgap prediction. • Oversampling technique. • Compressive sensing. [ABSTRACT FROM AUTHOR]

• Individual and combined applications of Ascorbic acid (AA) and Azotobacter chroococcum Avi2 were assessed in DT and DS-rice cultivars for photosynthetic efficacy, antioxidants and PGP under moisture deficit stress (MS). • Avi2 + AA enhanced RWC and chlorophyll contents in rice leaves, while reduced EL and proline under MS. • SOD, CAT and nifH gene were increased in Avi2 + AA under MS in both DT and DS rice cultivars. • Avi2 + AA also increased the ChlF- coefficients under MS, indicating a sign of plant wellness. • Overall, Avi2 + AA could serve as an effective formulation to alleviate MS vis à vis enhance PGP traits in rice. This group has previously reported the role of ascorbic acid (AA) as an antioxidant for survivability and ability to enhancing diazotrophic efficacy in Azotobacter chroococcum Avi2 under hydrogen peroxide (H 2 O 2) stress. However, the present study showed the combined application of AA and Avi2 in drought-susceptible (IR64 and Naveen) and drought-tolerant (Ankit and Satyabhama) rice cultivars to determine their photosynthetic efficacy (chlorophyll fluorescence-imaging), antioxidants, and plant growth-promotion (PGP) under moisture deficit stress (MS, −60 kPa). The results indicated that combined application of AA and Avi2 significantly (p < 0.05) increased the total chlorophyll, relative water content, electrolytic leakage, super oxide dismutase, and catalase activities in all rice cultivars as compared to other MS treatments, whereas stress indicators like proline and H 2 O 2 contents were proportionally increased under MS and their concentration were normalized under combined application of AA and Avi2. Photochemical quenching, non-photochemical quenching, photosynthetic electron transport rate, and the effective quantum efficiency were found to be increased significantly (p < 0.05) in Avi2 + AA as compared to other MS treatments. Moreover, rice roots harbored significantly (p < 0.05) higher copy number of nifH gene in Avi2 + AA treatment followed by Avi2 compared to flooded control and other MS treatments. Combined application of AA and Avi2 also increased the grain yield significantly (p < 0.05) by 7.09 % and 3.92 % in drought-tolerant (Ankit and Satyabhama, respectively) and 31.70 % and 34.19 % in drought-susceptible (IR64 and Naveen, respectively) rice cultivars compared to MS treatment. Overall, the present study indicated that AA along with Avi2 could be an effective formulation to alleviate MS vis à vis enhances PGP traits in rice. [ABSTRACT FROM AUTHOR]

Abstract: The sorption of Cd(II) from aqueous solution by rice husk, a surplus agricultural byproduct was investigated. Some simple and low-cost chemical modifications resulted in increasing the sorption capacity of raw rice husk (RRH) from 8.58mg/g to 11.12, 20.24, 16.18mg/g and reducing the equilibrium time from 10h of RRH to 2, 4 and 1h for epichlorohydrin treated rice husk (ERH), NaOH treated rice husk (NRH), sodium bicarbonate treated rice husk (NCRH), respectively. The effect of pH, sorption kinetics and isotherms were studied in batch experiments. Good correlation coefficient was obtained for pseudo second-order kinetic model, which agreed with chemisorption as the rate-limiting mechanism. Sorption isotherm test showed that equilibrium sorption data were better represented by Langmuir model than the Freundlich model. The highly efficient low cost and the rapid uptake of Cd(II) by NCRH indicated that it could be an excellent alternative for the removal of heavy metal by sorption process. [Copyright &y& Elsevier]

A novel copper-catalyzed chemoselective oxidative O -aroylation of 2-acetylphenols, alkyl salicylates and 1,3-dicarbonyl compounds with a wide range of styrene derivatives are described. This approach provides an efficient chemoselective preparation of phenol, alkyl salicylate and enol esters in good to excellent yields. This method represents an alternative protocol for the classical esterification reactions. [Display omitted] • Copper-catalyzed directing group assisted aroylation of phenols. • Chemoselective approach. • TBHP used as oxidant. • Additive, base, and ligand free, proceeds under mild conditions. • An alternative approach for the classical esterification reactions. [ABSTRACT FROM AUTHOR]

Eu-doped Sr 2 SnO 4 samples were synthesized using conventional ceramic route, followed by calcination at 1000 °C. Rietveld refinement analysis of XRD data indicates that the samples are single phase and crystallized into tetragonal crystal structure. Functional groups and metal-oxygen interaction has been studied using FTIR spectroscopy. The XPS analysis revealed the presence of oxygen vacancy, Sr in Sr2+ and Sn in Sn2+/Sn4+ in sample. The PL spectrum shows five peaks of Eu3+ due to transition 5D 0 →7F 0,1,2,3,4. The transition peaks 5D 0 →7F 0 and 5D 0 →7F 2 found most intense in PL spectra, and their ratio with 5D 0 →7F 1 were increased up to SSE6 and then decreased for SSE10, due to quenching phenomenon. An efficient energy transfer from oxygen vacancy to 5D 0 →7F 0 state leads to enormously increase in their intensity. By utilizing these absorption states and emission states as metastable state, the present sample can be used in UV-filter, UV-detector, and optical device applications. [ABSTRACT FROM AUTHOR]

Elevated carbon dioxide (eCO 2), higher dose of recommended nitrogen (HDN), and water deficit stress (WDS) are three important factors which influence individually on diazotrophic community in paddy soil, thereby affecting crop yield and its nitrogen use efficiency. However, the combined effects of eCO 2 , HDN, and WDS on soil diazotrophic community remains inadequate particularly in rice. Hence, the present study was conducted in CO 2 -maintained open-top chamber to assess the diazotrophic community under combined influence of eCO 2 (550 ± 20 μmol mol−1 as compared to ambient CO 2 i.e. 400 ± 10 μmol mol−1) and HDN (120 kg N ha−1, 50% higher than recommended dose of N for rice i.e. 80 kg N ha−1, in sub-humid tropical region of eastern India) with and without WDS (−60 kPa) at two growth stages of rice (tillering, TI and panicle initiation, PI) and correlated with soil carbon (C) pools and enzyme activities. The results indicated that soil organic C, readily mineralizable C, microbial biomass C, acid and alkaline phosphatase activities were significantly (p < 0.05) increased under combined influence of eCO 2 and HDN at both TI and PI stages of rice without WDS. The results also showed that abundance of nifH varied from ambient CO 2 (aCO 2) to eCO 2 and found higher in aCO 2 under recommended dose of nitrogen (RDN) without WDS, whereas under eCO 2 , nifH copy number was found higher under HDN at both TI and PI stages of rice without WDS. Biplot analysis revealed that abundance of nifH and nitrifiers were highly correlated under aCO 2 coupled with RDN without WDS. Illumina MiSeq®-based targeted nifH metagenome showed that eCO 2 encouraged the relative abundance of Proteobacteria and Cyanobacteria, whereas suppressed the other diazotrophic phyla like Actinobacteria, Firmicutes, and Chlorobi, but the reverse trend was observed in HDN treatments. Heatmap analysis revealed a unique differentiation of Rhizobiales and Pseudomonadales under eCO 2 coupled with RDN without WDS. Moreover, three-way interactions of eCO 2 , HDN, and WDS also showed significant (p < 0.05) difference of soil C pools and enzymatic activities at both growth stages of rice. Overall, the present study showed that diazotrophic community in paddy soil was significantly (p < 0.05) altered by the additive effects of eCO 2 , HDN, and WDS. • Diazotrophs were analyzed under combined influence of eCO 2 , HDN, and water deficit paddy soil. • Abundance of nifH was significantly increased under combined effects of eCO 2 and HDN. • nifH- Illumina MiSeq® revealed that 35.6 to 66.2% of OTUs belonged to Bradyrhizobiaceae. • Rhizobiales and Pseudomonadales were predominant in eCO 2 and RDN without WDS. • eCO 2 and HDN significantly increased the soil carbon pools and enzyme activities in paddy soil. [ABSTRACT FROM AUTHOR]

This paper reviews dissimilatory nitrate reduction to ammonium (DNRA) in soils - a newly appreciated pathway of nitrogen (N) cycling in the terrestrial ecosystems. The reduction of NO 3 − occurs in two steps; in the first step, NO 3 − is reduced to NO 2 −; and in the second, unlike denitrification, NO 2 − is reduced to NH 4 + without intermediates. There are two sets of NO 3 −/NO 2 − reductase enzymes, i.e., Nap/Nrf and Nar/Nir; the former occurs on the periplasmic-membrane and energy conservation is respiratory via electron-transport-chain, whereas the latter is cytoplasmic and energy conservation is both respiratory and fermentative (Nir, substrate-phosphorylation). Since, Nir catalyzes both assimilatory- and dissimilatory-nitrate reduction, the nrfA gene, which transcribes the NrfA protein, is treated as a molecular-marker of DNRA; and a high nrfA / nosZ (N 2 O-reductase) ratio favours DNRA. Recently, several crystal structures of NrfA have been presumed to producee N 2 O as a byproduct of DNRA via the NO (nitric-oxide) pathway. Meta-analyses of about 200 publications have revealed that DNRA is regulated by oxidation state of soils and sediments, carbon (C)/N and NO 2 −/NO 3 − ratio, and concentrations of ferrous iron (Fe2+) and sulfide (S2−). Under low-redox conditions, a high C/NO 3 − ratio selects for DNRA while a low ratio selects for denitrification. When the proportion of both C and NO 3 − are equal, the NO 2 −/NO 3 − ratio modulates partitioning of NO 3 −, and a high NO 2 −/NO 3 − ratio favours DNRA. A high S2−/NO 3 − ratio also promotes DNRA in coastal-ecosystems and saline sediments. Soil pH, temperature, and fine soil particles are other factors known to influence DNRA. Since, DNRA reduces NO 3 − to NH 4 +, it is essential for protecting NO 3 − from leaching and gaseous (N 2 O) losses and enriches soils with readily available NH 4 +-N to primary producers and heterotrophic microorganisms. Therefore, DNRA may be treated as a tool to reduce ground-water NO 3 − pollution, enhance soil health and improve environmental quality. Unlabelled Image • DNRA is a novel and shortest biological pathway of N-cycling in terrestrial ecosystems where NO 3 - is reduced to NH 4 + in soils • This pathway has potential to reduce N 2 O emissions and protect NO 3 - from leaching losses • It outcompetes the denitrification process under limited NO 3 - availability in the system • It enriches soil with NH 4 +-N and make available to primary producers as N-fertilizer • Meta-analyse revealed that DNRA is mainly regulated by C/N ratio, NO 2 - / NO 3 - ratio and S2- [ABSTRACT FROM AUTHOR]

The samples of (Ba 1−x Sr x) 2 SnO 4 with x = 0, 0.10, 0.20, 0.40, 0.80, 1.00 were synthesized by a high-temperature solid state ceramic route. Lattice parameters obtained from the Rietveld profile analysis; decreased with increasing Sr. The decreasing nature of lattice parameters indicated the complete solubility of Sr at Ba-site. Further, incorporation of Sr at Ba-site has been studied by Fourier transform infrared (FTIR) spectroscopy. The dielectric constant and dissipation factor increases with increasing Sr. Contribution of grain and grain boundary were resolved by complex modulus spectroscopy analysis. AC conductivity spectra of the entire sample follow Universal Jonscher's power law. The similar value of activation energy obtained from relaxation frequency and dc conductivity implies that the origin of conduction and relaxation mechanisms remains the same throughout the samples. The modulus and conductivity spectra of solid solutions nicely follow the time-temperature superposition (TTSP) principle. Further, conductivity spectra of solid solutions were studied by Ghosh and Summerfield scaling. • The solubility of Sr in Ruddlesden popper system (Ba 1-x Sr x) 2 SnO 4 has achieved upto 100%. • Giant dielectric properties have been observed and compared to other layered perovskites. • Non-Debye type relaxation process occurred in the solid solution of Ruddlesden Popper system. • Relaxation and Conduction process takes place by hoping of electron between degenerate sites of Sn (Sn4+/Sn2+). • Scaling studies suggests that relaxation/conduction processes are temperature and compositional independent. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) are one of the beneficial soil microbial communities, playing an important role in abiotic and biotic stress management in agricultural crops, including rice. Climate change, particularly elevated CO 2 (eCO 2) alters the soil microbial community, but the alteration of AMF community has received little attention, partly because of inadequacy in understanding of AMF taxonomy. Therefore, an attempt was made to understand AMF community in paddy soil under long-term exposure (8 years) to eCO 2 through sequencing 18S rRNA small subunit SSU based Illumina Miseq technique using the primer pair AML1/AML2. Changes in OTUs belonging to 23 AMF species were identified in the ambient (400 ± 10 μmol mol−1) and eCO 2 (550 ± 20 μmol mol−1) conditions, respectively based on reads alignment using Maarj AM VT database. Moreover, principal coordinate (PCO) analysis clustered the related OTUs and suggested that long-term exposure of eCO 2 suppressed the OTUs of Glomerales and encouraged the OTUs of Diversisporales. Overall, the present study indicates that long-term exposure of paddy soil to eCO 2 (550 ppm) drastically reduced the commonly occuring AMF such as Claroideoglomus and Glomus species in sub-humid tropical condition. Unlabelled Image • Illumina MiSeq based AMF diversity was studied in paddy soil under ambient and elevated CO 2 conditions. • AML1/AML2 primer pair can be used to study AMF diversity in Illumina MiSeq platform. • Long-term exposure of elevated CO 2 in paddy soil drastically reduced Glomerales and encouraged Diversisporales. • Elevated CO 2 significantly improved SOC and microbiological properties in paddy soil. [ABSTRACT FROM AUTHOR]

Triticum aestivum L. known as common wheat is one of the most important cereal crops feeding a large and growing population. Various environmental stress factors including drought, high salinity and heat etc . adversely affect wheat production in a significant manner. Dehydration-responsive element-binding (DREB1A) factors, a class of transcription factors (TF) play an important role in combating drought stress. It is known that DREB1A specifically interacts with the dehydration responsive elements (DRE/CRT) inducing expression of genes involved in environmental stress tolerance in plants. Despite its critical interplay in plants, the structural and functional aspects of DREB1A TF in wheat remain unresolved. Previous studies showed that wheat DREBs ( DREB1 and DREB2 ) were isolated using various methods including yeast two-hybrid screens but no extensive structural models were reported. In this study, we made an extensive in silico study to gain insight into DREB1A TF and reported the location of novel DREB1A in wheat chromosomes. We inferred the three-dimensional structural model of DREB1A using homology modelling and further evaluated them using molecular dynamics(MD) simulations yielding refined modelled structures. Our biochemical function predictions suggested that the wheat DREB1A orthologs have similar biochemical functions and pathways to that of AtDREB1A. In conclusion, the current study presents a structural perspective of wheat DREB1A and helps in understanding the molecular basis for the mechanism of DREB1A in response to environmental stress. [ABSTRACT FROM AUTHOR]

In this research article, the emphasis is given on the simulation of optical and electronic characteristics of ITO/NPB/Alq 3 :DCJTB/Alq 3 /Ag heterostructure based organic light emitting diode (OLED). Under simulation, the behavior of excitons associated with EML and ETL have been studied with variation in anode voltage and current. In order to simulate the spectral characteristics, the Holstein model has been used for the Alq 3 and DCJTB spectra in electron transport and emissive layers. The photon propagation model has been used to study the Purcell factor. In results, we have achieved I–V characteristics, luminescent power, output spectral power density, spectral radiance and spectral luminous flux. According to the results achieved, the operating voltage is found ∼ 4 V and the highest luminous flux of the designed OLED corresponds to ∼ 565 nm (yellow/orange color) in visible region. Hence, the designed OLED may be very suitable for emission of yellow/orange light at very low voltage ∼ 4 V. [ABSTRACT FROM AUTHOR]

• The samples have been synthesized using Sol-Gel combustion route at 60 °C. • All samples are crystallized into cubic spinel group under space group (Fd 3 ¯ m). • Positive zeta potential reflects stability of nano-powders in conducting liquid. • Optical band gap of samples reflects inorganic semiconducting nature. • Temperature-dependent resistivity shows Arrhenius type conduction in samples. The Ni modified samples ZnFe 2-x Ni x O 4 with x = 0, 0.05, and 0.10 were synthesized using the sol-gel combustion method at 60 °C. The phase of obtained samples was determined using X-ray powder diffraction and found that it crystallized into a cubic spinel group. The lattice parameter of samples was decreased with increasing Ni concentration. However, the local symmetry of samples was explored using Raman spectroscopy. The presence of Raman band at 655 cm−1 was assigned to the vibration of Fe-O; found to be shifted towards higher wavenumber reconfirm the incorporation of Ni. The optical bandgap of the samples was determined using the Tauc plot and found to be in the range of 2.50 to 2.95 eV, which reflects the inorganic semiconducting nature of samples. Dielectric properties of samples were studied as a function of frequency and temperature show the presence of interfacial and orientational polarization in the sample. The resistivity of samples has been studied using Arrhenius model, and found three different regions of conduction within investigated temperature range. The first region assigned to the hopping of electron, while the second region to the hopping of polaron via the orientation of dipole (2 Ni Fe ' - 2 h.) , or (2 Ni Fe ' - V o..) , and the third region assigned to migration of V o.. or e ' / h.. The conductivity of samples found in range of (0.85–8.95) S-cm−1 higher than conventional electrolytes used in IT-SOFCs. Based on these studies, the present materials can be used as a potential candidate for semiconductor devices and electrolytes in IT-SOFCs applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A deep learning model is developed for efficient process modeling using a limited amount of experimental data. • The model facilitates an under 0.9% discrepancy rate with the actual process by distilling physics-based knowledge from FEM simulation. • The data augmentation based on the deep learning model generates realistic data from FEM simulation and experimental data. • The developed deep learning strategy alleviates the overfitting of learning weights, thereby achieving the high performance of inverse design. In manufacturing industry, finding optimal design parameters for targeted properties has traditionally been guided by trial and error. However, limited data availability to few hundreds sets of experimental data in typical materials processes, the machine-learning capabilities and other data-driven modeling (DDM) techniques are too far from it to be practical. In this study, we show how a versatile design strategy, tightly coupled with physics-based modeling (PBM) data, can be applied to small set of experimental data to improve the optimization of process parameters. Our strategy uses PBM to achieve augmented data that includes essential physics: in other words, the PBM data allows the inverse design model to 'learn' physics, indirectly. We demonstrated the accuracy of both forward-prediction and inverse-optimization have been dramatically improved with the help of PBM data, which are relatively cheap and abundant. Furthermore, we found that the inverse model with augmented data can accurately optimize process parameters, even for ones those were not considered in the simulation. Such versatile strategy can be helpful for processes/experiments for the cases where the number of collectable data is limited, which is most of the case in industries. [ABSTRACT FROM AUTHOR]

Abstract Rice is the foremost staple food in the world, safeguarding the global food and nutritional security. Rise in atmospheric carbon dioxide (CO 2) and water deficits are threatening global rice productivity and sustainability. Under real field conditions these climatic factors often interact with each other resulting in impacts that are remarkably different compared to individual factor exposure. Rice soils exposed to drought and elevated CO 2 (eCO 2) alters the biomass, diversity and activity of soil microorganisms affecting greenhouse gas (GHG) emission dynamics. In this review we have discussed the impacts of eCO 2 and water deficit on agronomic, biochemical and physiological responses of rice and GHGs emissions from rice soils. Drought usually results in oxidative stress due to stomatal closure, dry weight reduction, formation of reactive oxygen species, decrease in relative water content and increase in electrolyte leakage at almost all growth and developmental phases of rice. Elevated atmospheric CO 2 concentration reduces the negative effects of drought by improving plant water relations, reducing stomatal opening, decreasing transpiration, increasing canopy photosynthesis, shortening crop growth period and increasing the antioxidant metabolite activities in rice. Increased scientific understanding of the effects of drought and eCO 2 on rice agronomy, physiology and GHG emission dynamics of rice soil is essential for devising adaptation options. Integration of novel agronomic practices viz., crop establishment methods and alternate cropping systems with improved water and nutrient management are important steps to help rice farmers cope with drought and eCO 2. The review summarizes future research needs for ensuring sustained global food security under future warmer, drier and high CO 2 conditions. Graphical abstract Unlabelled Image Highlights • Agronomic management options are promising for mitigating water deficit stress. • Rice crop behavior under elevated CO 2 condition was discussed. • Opportunities under elevated CO 2 are reviewed to explore the future research needs. [ABSTRACT FROM AUTHOR]

Abstract Use of plant-associated beneficial microbes, especially endophytes are getting popular day by day as they occupy a relatively privileged niche inside different plant tissues with lesser competition for food and shelter than rhizosphere. The effects of different physical factors like temperature, rainfall, and seasonal variation and UV radiation on plant growth promoting endophytic communities are less pronounced than those on the rhizospheric and phylloplane microbes. This present work has been compromised with further utilization of an indigenous rice (Oryza sativa L.) root endophytic Azotobacter sp. strain Avi2 (MCC 3432) (AzA) as a bio-formulation for sustainable rice production based on several physiological parameters (plant height, root length/weight, leaf area, yield, chlorophyll contain), in-vitro comparative plant growth promoting assays, greenhouse and field experiments (dry and wet season). Treatments with AzA exhibited higher yield as well as maximal chlorophyll fluorescence (Fm) of flag leaves in flowering and grain filling stages indicating higher photosynthetic rates. Scanning electron microscopic image of rice roots demonstrated accumulation of bacterial biofilm at the junction of primary and lateral root confirming the root-colonizing ability of the bacterium. The results of the study were quite encouraging as AzA exhibited better vegetative and reproductive growth of rice in pot and field experiment compared to formulated rhizospheric Azotobacter sp. (commercial product). Apart from that plants treated with AzA (supplemented 50% nitrogenous fertilizer of recommended dose) exhibited similar yield parameters when it was compared with the recommended dose of fertilizer (RDF; 120:60:60 mg N:P:K kg−1 soil/ without any bacterial). Therefore, it can be concluded that application of this plant growth promoting endophyte can reduce a substantial amount of N-fertilizer for field application. [ABSTRACT FROM AUTHOR]

Biochar plays a pivotal role in carbon storage-fractionation-mineralization process in soil. However, uncertainty still remains about the influence of biochar on these inter-related processes that links to C cycling in soil. A three years field experiment was initiated in 2013 at ICAR-National Rice Research Institute, Cuttack, India, to study the deviation in C mineralization and C fractions caused by the application of six doses of rice husk derived biochar (RHB), ranging from 0.5 t ha −1 to 10.0 t ha −1 . The results showed an increase in cumulative CO 2 -C emission with increasing RHB rates. However, the model-fitted mineralization rates (dC/dt) did not show significant difference between treated and control soils at the end of incubation period in a laboratory study. In addition, microbial quotient and % C from RHB utilized showed a decreasing trend with increasing rates of RHB application, establishing the carbon sequestration potential of RHB. The highest rate (10.0 t ha −1 ) of RHB application accumulated maximum total organic C (3.26%) and a larger share of non-labile C (63.8%) among the treatments. An increase in rice grain yield (1–24%, depending on rate of RHB application) was observed with increasing rates of RHB which further established that RHB application not only enhanced C storage but also enhanced the productivity of rice by enhancing the soil fertility. [ABSTRACT FROM AUTHOR]

Suitable method of application of urea briquette in flooded rice ( Oryza sativa L.) not only increases nitrogen use efficiency, but at the same time sustain yield and reduce greenhouse gas emission in general and nitrous oxide emission in particular. Keeping this hypothesis, seven different treatments including manual and mechanical mode of application with two different type of applicators were tested in field in consecutive wet (2015) and dry (2016) seasons. Three row briquette applicator (TRBA) and top dressing applicator (TDA) were used in combination for basal and top dressing application along with prilled urea broadcasting and without application as well. It was observed the use of TRBA at basal with first top dressing by TDA and manual placement of urea briquette at second top dressing (TRBA + TDA) yielded highest @ 6.71 t ha −1 and 5.47 t ha −1 in the wet and dry seasons, respectively, with the highest agronomic use efficiency (36.3 kg kg −1 ). Average emission of methane from all treatments were higher (19.2–27.1%) during wet season than the dry season and vice versa in case of nitrous oxide (3.6–11.8%). Among the treated plots, TRBA + TDA recorded the lowest emission of nitrous oxide. The largest amount of ammonia was lost through volatilization after basal application of urea, followed by top dressing at the end of maximum tillering stage and panicle initiation stage. As a whole, volatilization loss of N was lowest in control (3.3–3.4 mg NH 3 -N m −2 d −1 ), followed by mechanical (27.6–33.9 mg NH 3 -N m −2 d −1 ) and manual (49.1–55.3 mg NH 3 -N m −2 d −1 ) method of urea briquette application. The population of nitrite oxidizers and heterotrophs were highest in prilled urea broadcasting. Soil dehydrogenase activity was the highest in urea briquette manual placement + top dressing applicator (UBMP + TDA, 148.0 μg–160.0 TPF g −1 soil d −1 ) treatment, while the urease activity was less was in urea applicator treated plots. Subsurface application of larger size urea (urea briquette) and applicator based precise placement of urea reduced the lossess of nitrogen through ammonia volatilization and nitrous oxide emission, thus enhanced nitrogen use efficiency. Apart from that, issue of adequate skilled labour for precise depth of application could be tackled by effectively adopting mechanical placement of urea briquette. The mechanical placement of briquette (relatively larger size particle) in tropical flooded rice is more precise and less labour intensive, hence this is an efficient environment friendly approach of N management. [ABSTRACT FROM AUTHOR]