Roots are the primary site of interaction between plants and microorganisms. To meet food demands in changing climates, improved yields and stress resistance are increasingly important, stimulating ...efforts to identify factors that affect plant productivity. The role of bacterial endophytes that reside inside plants remains largely unexplored, because analysis of their specific functions is impeded by difficulties in cultivating most prokaryotes. Here, we present the first metagenomic approach to analyze an endophytic bacterial community resident inside roots of rice, one of the most important staple foods. Metagenome sequences were obtained from endophyte cells extracted from roots of field-grown plants. Putative functions were deduced from protein domains or similarity analyses of protein-encoding gene fragments, and allowed insights into the capacities of endophyte cells. This allowed us to predict traits and metabolic processes important for the endophytic lifestyle, suggesting that the endorhizosphere is an exclusive microhabitat requiring numerous adaptations. Prominent features included flagella, plant-polymer-degrading enzymes, protein secretion systems, iron acquisition and storage, quorum sensing, and detoxification of reactive oxygen species. Surprisingly, endophytes might be involved in the entire nitrogen cycle, as protein domains involved in N(2)-fixation, denitrification, and nitrification were detected and selected genes expressed. Our data suggest a high potential of the endophyte community for plant-growth promotion, improvement of plant stress resistance, biocontrol against pathogens, and bioremediation, regardless of their culturability.
High resolution time series data of hydrogen (
δD) and oxygen (
δ
18O) isotope values of precipitation have been generated for the first time at Kolkata, eastern India where the summer monsoon clouds ...from Bay of Bengal (BOB) commence their journey over India. Use of a Rayleigh cum two component mixing model and comparison of Kolkata data with the International Atomic Energy Agency (IAEA)–Global Network of Isotopes in Precipitation (GNIP) data base of New Delhi suggest that the precipitation at New Delhi cannot be explained by simple continental effect of a BOB vapour source alone, traveling and raining successively along Kolkata–New Delhi route. It is necessary to invoke an admixture of ∼
20% vapour originating from the Arabian sea with the vapour coming from BOB and finally causing summer monsoon rains at New Delhi. The findings have major implications to the regional water vapour budget over India.
In the present paper, the ATLAS inclusive W± and Z boson production data are analyzed together with the CMS inclusive W± and Z boson production data to investigate any possible tensions between the ...data sets and to determine the strange sea fraction, within the framework of a parton distribution function fit at next-to next-to-leading order in perturbative QCD.
Mesoporous NiO samples with different morphology were synthesized by hydrothermal method, and they were studied as electrocatalysts for oxygen evolution reaction in alkaline solution. The NiO samples ...were characterized by X-ray diffraction, transmission electron microscopy, N2-adsorption, scanning electron microscopy and X-ray photoelectron spectroscopy. The critical synthesis parameters like hydrothermal reaction temperature, time and molar ratio of precursors were varied using Taguchi experimental method to investigate their effect on morphology and specific surface area of mesoporous NiO samples. The characterization data illustrated the formation of nanoplates, nanorods, and nanoparticles. All the NiO samples exhibited mesoporosity and the specific surface area values in the range of 88–156 m2/g. One of the synthesized mesoporous NiO samples, largely constituting of nanoplates and nanorods with high porosity, exhibited a Tafel slope of 62 mV/dec and achieved a current density of 41.6 mA/cm2 at 1.6 V (vs. RHE). It showed better electrocatalytic activity for oxygen evolution reaction than remaining samples.
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•Mesoporous NiO samples with different morphology were prepared by hydrothermal method.•Effect of different synthesis parameters on structures of mesoporous NiO was studied.•Synthesis parameters were varied using Taguchi experimental method.•They were studied as electrocatalysts for OER in alkaline medium.•NiO constituted with largely nanoplates and nanorods showed better OER activity.
Nanostructured materials play an important role in advancing the electrochemical energy storage and conversion technologies such as lithium ion batteries and fuel cells, offering great promise to ...address the rapidly growing environmental concerns and the increasing global demand for energy. In this review, we summarize some of the recent progress and advances in our laboratory on nanostructured electrode materials for lithium ion batteries and platinum-based and platinum-free nanoalloy electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFC). Materials design, novel chemical synthesis and processing, advanced materials characterization, and electrochemical evaluation data are presented.
Signaling networks that convert graded stimuli into binary, all-or-none cellular responses are critical in processes ranging from cell-cycle control to lineage commitment. To exhaustively enumerate ...topologies that exhibit this switch-like behavior, we simulated all possible two- and three-component networks on random parameter sets, and assessed the resulting response profiles for both steepness (ultrasensitivity) and extent of memory (bistability). Simulations were used to study purely enzymatic networks, purely transcriptional networks, and hybrid enzymatic/transcriptional networks, and the topologies in each class were rank ordered by parametric robustness (i.e., the percentage of applied parameter sets exhibiting ultrasensitivity or bistability). Results reveal that the distribution of network robustness is highly skewed, with the most robust topologies clustering into a small number of motifs. Hybrid networks are the most robust in generating ultrasensitivity (up to 28%) and bistability (up to 18%); strikingly, a purely transcriptional framework is the most fragile in generating either ultrasensitive (up to 3%) or bistable (up to 1%) responses. The disparity in robustness among the network classes is due in part to zero-order ultrasensitivity, an enzyme-specific phenomenon, which repeatedly emerges as a particularly robust mechanism for generating nonlinearity and can act as a building block for switch-like responses. We also highlight experimentally studied examples of topologies enabling switching behavior, in both native and synthetic systems, that rank highly in our simulations. This unbiased approach for identifying topologies capable of a given response may be useful in discovering new natural motifs and in designing robust synthetic gene networks.
Here we report a novel hydrothermal method to synthesize hybrid nanostructures based on single phase cobalt disulfide (CoS2) nanoparticles decorated on multiwalled carbon nanotubes (MWCNT) for ...application as supercapacitor electrode. This is also the first report on systematic investigation of the influence of MWCNTs on the electrochemical properties of CoS2 nanoparticle based electrode for supercapacitor. The X-ray diffraction and electron microscopic analyses revealed that incorporation of CNTs promotes the growth of only the CoS2 phase in the form of spherical nanoparticles with an average diameter of ∼9 nm. CoS2-MWCNT nanohybrid electrode containing 20 wt % MWCNT showed the highest specific capacitance of 1486 F/g at 1 A/g discharge current density along with excellent reversibility. It also showed high cycle stability with ∼80% retention of specific capacitance even after 10,000 cycles. Thus, we show a low cost and simple method to synthesize a CoS2-MWCNT nanohybrid that has great promise as electrode material for supercapacitor applications. Incorporation of CNT not only provides a conducting network for fast charge diffusion but (due to large surface area) also allows more CoS2 molecules to be readily available for redox reaction resulting in the reduction of the charge transfer resistance consistent with the data obtained from electrochemical impedance spectroscopy.
Molecular biomarkers are used world wide for quick assessment of the immediate effect of environmental pollution on marine ecosystems. Recently, we evaluated oxidative stress responses of marine rock ...oyster, Saccostrea cucullata impacted due to polycyclic aromatic hydrocarbons (PAHs) accumulated in their tissues at a few sampling sites along the coast of Goa around the region of the Arabian sea coast, India (Sarkar et al., 2017). Using a combination of partial alkaline unwinding and comet assays, we now report a comprehensive study on the impairment of DNA integrity (DI) in S. cucullata due to exposure to environmentally available PAHs and also heavy metals (Pb, Cd, Cu, Fe and Mn) along the Arabian Sea coast, Goa, India exclusively around the entire coast of Goa. First, we determined significant correlation between DI in S. cucullata and the extent of exposure to and bioaccumulation of different PAH compounds including 2–3 aromatic ring PAHs (R2, 0.95), 4–6 aromatic ring PAHs (R2, 0.85), oxygenated-PAHs (oxy-PAHs, R2, 0.84) and total PAHs (t-PAHs, R2, 0.98). Second, we observed dose-dependent decrease in DI in S. cucullata with increasing concentrations of different PAH components in oyster tissues. We substantiated our field observations with appropriate laboratory controls using benzoapyrene (BaP). Third, we performed stepwise multiple regression analyses of different water quality parameters including pH, salinity, temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrite (NO2), nitrate (NO3), phosphate (PO4), turbidity and also t-PAH-biota, t-PAH-water with DI as the dependent variable. Among all these parameters, only four parameters such as t-PAH-biota in combination with DO, BOD and NO2 showed significant correlation (R¯2 = 0.95) with loss in DI in S. cucullata. Based on these results, we created a map indicating the percentage of DNA damage in S. cucullata exposed to PAHs and heavy metals at each sampling location along the west coast of India around Goa, India.
•DNA damage in S. cucullata induced by environmental exposure to pollutants like PAHs, heavy metals etc.•Significant correlation observed between the loss of DNA integrity in rock oyster and the concentration of PAHs in oyster.•Laboratory exposure of S. cucullata to Benzo(a)pyrene substantiate the occurrence of impairment of DNA integrity.•S. cucullata is found to be an useful sentinel species for bio-monitoring of pollution.
Bayesian approaches to include real-world data in clinical studies Müller, P; Chandra, N K; Sarkar, A
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
05/2023, Letnik:
381, Številka:
2247
Journal Article
Recenzirano
Randomized clinical trials have been the mainstay of clinical research, but are prohibitively expensive and subject to increasingly difficult patient recruitment. Recently, there is a movement to use ...real-world data (RWD) from electronic health records, patient registries, claims data and other sources in lieu of or supplementing controlled clinical trials. This process of combining information from diverse sources calls for inference under a Bayesian paradigm. We review some of the currently used methods and a novel non-parametric Bayesian (BNP) method. Carrying out the desired adjustment for differences in patient populations is naturally done with BNP priors that facilitate understanding of and adjustment for population heterogeneities across different data sources. We discuss the particular problem of using RWD to create a synthetic control arm to supplement single-arm treatment only studies. At the core of the proposed approach is the model-based adjustment to achieve equivalent patient populations in the current study and the (adjusted) RWD. This is implemented using common atoms mixture models. The structure of such models greatly simplifies inference. The adjustment for differences in the populations can be reduced to ratios of weights in such mixtures. This article is part of the theme issue 'Bayesian inference: challenges, perspectives, and prospects'.
A
bstract
The impact of measurements of heavy-flavour production in deep inelastic
ep
scattering and in
pp
collisions on parton distribution functions is studied in a QCD analysis at next-to-leading ...order. Recent combined results of inclusive and heavy-flavour produc- tion cross sections in deep inelastic scattering at HERA are investigated together with heavy-flavour production measurements at the LHC. Differential cross sections of charm- and beauty-hadron production measured by the LHCb collaboration at the centre-of-mass energies of 5, 7 and 13 TeV as well as the recent measurements of the ALICE experiment at the centre-of-mass energies of 5 and 7 TeV are explored. These data impose additional constraints on the gluon and the sea-quark distributions at low partonic fractions
x
of the proton momentum, down to
x ≈
10
−
6
. The impact of the resulting parton distribution function in the predictions for the prompt atmospheric-neutrino fluxes is studied.
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