Investigation on the Biocontrol of Phytophthora diseases on strawberry based on antagonism

After screening of several rhizosphere bacteria against the soilborne pathogens of red core and crown rot disease of strawberry Phytophthora fragariae var. fragariae and Phytophthora cactorum under in vitro conditions, three of the most active isolates which produced up to 63% of reduction in mycelium growth, such as Raoultella terrigena (G-584), Bacillus amyloliquefaciens (G-V1) and Pseudomonas fluorescens (2R1-7) were selected for further studies under in vivo conditions. In a greenhouse and field experiments, mentioned above three isolates were tested against both Phytophthora diseases under artificial infested soil conditions. Root dip treatment with these bacterial antagonists produced a control effect on both fungal diseases between 27 to 55 % and were in some cases comparable with the chemical fungicide Aliette

Effect of alkaline treatment on the sulfate content and quality of semi-refined carrageenan prepared from seaweed Kappaphycus alvarezii Doty (Doty) farmed in Indian waters

Seaweed Kappaphycus alvarezii previously known as Eucheuma cottonii is one of the best sources of kappa carrageenan and is cultivated in Philippines, Indonesia, Malaysia and other countries including India. In the present study, semi-refined carrageenan (SRC) was prepared from K. alvarezii with different concentrations of KOH (6, 12, 18 and 24%) at 80 ± 2°C for 2 h; its sulfate contents were 13.73±0.74, 13.66±0.27, 13.84±0.66 and 14.76±0.18%, respectively, and it was 14.10±0.34% for untreated clean weed (control). The sulfate removal with increasing concentration of KOH used for processing SRC is not statistically significant (p < 0.05). The KCl gel strength of untreated clean weed and 6, 12, 18 and 24% KOH treated weed was 97±10.27, 650±12.11, 637±10.25, 552±18.71 and 526±26.55 g cm-2, respectively. Contents of 3,6-anhydrogalactose were 28.30±0.52, 33.41±0.50, 32.97±0.42, 31.15±0.60 and 31.61±0.17%. FTIR spectroscopy showed that molecules in all four SRC samples are quite similar. Spectral band was at 1257 cm-1 which referred to ester sulfate of 930 cm-1 for 3,6 anhydrogalactose and 848 cm-1 assigned to galactose-4-sulfate. From the present investigation, it was observed that sulfate removal and quality improvement with increasing concentration of KOH for cooking seaweed is not statistically significant; therefore, seaweed can be subjected to lower concentration of KOH treatment (6 to 12%) to produce semi-refined carrageenan on commercial scale.Keywords:  Seaweed, Kappaphycus alvarezii, KOH treatment, semi-refined carrageenan (SRC), sulfate content, FTIR spectra, gel strength.Abbreviation: SRC, semi-refined carrageenan; 3,6-AG, 3,6-anhydrogalacotse; FTIR, Fourier Transform Infrared Spectroscopy

Computational modelling of meiotic entry and commitment

In response to developmental and environmental conditions, cells exit the mitotic cell cycle and enter the meiosis program to generate haploid gametes from diploid germ cells. Once cells decide to enter the meiosis program they become irreversibly committed to the completion of meiosis irrespective of the presence of cue signals. How meiotic entry and commitment occur due to the dynamics of the regulatory network is not well understood. Therefore, we constructed a mathematical model of the regulatory network that controls the transition from mitosis to meiosis in Schizosaccharomyces pombe. Upon nitrogen starvation, yeast cells exit mitosis and undergo conjugation and meiotic entry. The model includes the regulation of Mei2, an RNA binding protein required for conjugation and meiotic entry, by multiple feedback loops involving Pat1, a kinase that keeps cells in mitosis, and Ste11, a transcription activator required for the sexual differentiation. The model accounts for various experimental observations and demonstrates that the activation of Mei2 is bistable, which ensures the irreversible commitment to meiosis. Further, we show by integrating the meiosis-specific regulation with a cell cycle model, the dynamics of cell cycle exit, G1 arrest and entry into meiosis under nitrogen starvation. © 2017 The Author(s)

Unusual seedless approach to gold nanoparticle synthesis: application to selective rapid naked eye detection of mercury(II)

Report a novel seedless Hg2+-induced synthetic approach for the preparation of gold nanostructures. This protocol is demonstrated for the highly selective and sensitive naked eye detection of Hg2+ based on the high affinity metallophilic Hg2+–Au+ interaction. The response time upon exposure to Hg2+ is almost instantaneou

SWOT analysis of the electrochemical reactivity of different carbon paste electrodes

275-282<span style="font-size:11.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" te"="" lang="EN-GB">The electroactivity of different carbonaceous materials suitable for electroanalytical applications has been described. Voltammetric studies reveal that only Vulcan carbon and single walled carbon nanotube show well defined voltammetric behavior with clear peak-to-peak separation close to the Nernstian behavior. Acetylene and activated carbon does not show the expected electroactivity and the reason is discussed with the help of electrochemical impedance analysis. The varied performances in terms of structure and morphology of different carbonaceous materials are further characterized using Raman spectroscopy, contact angle measurement, scanning electron microscope and thermo gravimetric analysis.</span

Non-enzymatic organophosphorus pesticide detection using gold atomic cluster modified electrode

In this work,we report the detection of organophosphorous pesticides, particularlymethyl parathion using gold atomic clusters (AuACs) non-enzymatically employing squarewave voltammetry (SWV). Synthesis of surfactant stabilized gold atomic clusters on a polycrystalline gold electrode was executed by a simple potentiodynamic cyclic voltammetry technique. The clusters are characterized using UV–visible spectroscopy and transmission electron microscopy techniques. The electroanalytical results exhibited linear behavior in the micro (10–80 μM) as well as nanomolar (1–10 nM) concentration ranges and the detection limit is found to be 0.65 nM (S/N=3). The proposed sensor matrix is evaluated with real samples and the results are in good agreement with high performance liquid chromatographic (HPLC) analysis

<i style="">In situ </i>bismuth film modified carbon fiber microelectrode for nanomolar detection of cadmium and lead

699-703In situ bismuth film modified carbon fiber microelectrode is reported for sensitive detection of Cd(II) and Pb(II) in 0.1 M acetate buffer solution of pH 4.5. As compared to the unmodified electrode, in situ bismuth modification improves the detection limit at nanomolar level for individual as well as simultaneous detection of Cd(II) and Pb(II). Electroanalysis carried out using square wave anodic stripping voltammetry shows linear response over the 50-500 nM range. The minimum detection limits are not affected for the individual and simultaneous metal detection. Using the standard addition method, cadmium and lead have been detected in tap water samples successfully

Fabrication of dendritic nanoporous gold via a two-step amperometric approach: Application for electrochemical detection of methyl parathion in river water samples

In this work, nanoporous gold (NPG) was prepared according to three different approaches, such as (i) anodization-electrochemical reduction (A-ECR, NPGA), (ii) dynamic hydrogen bubble template (DHBT, NPGB), and (iii) the combination of both methods (NPGA+B). Field-emission scanning electron microscopy (FE-SEM) and cyclic voltammetry (CV) were used to investigate the structural morphology and the electrochemical behavior of the fabricated materials. The NPGA+B electrode showed a large amount of surface defects and/or edges, greater electrochemical surface area (2.5 cm2), and increased roughness factor (35.4). Such outstanding features of the NPGA+B platform were demonstrated by the sensitive detection of methyl parathion (MP) in river water samples. CV results indicated nearly 25-fold, 6-fold, and 2.5-fold higher sensitivity for NPGA+B compared to that of bare Au, NPGA, and NPGB, respectively. Differential pulse voltammetry (DPV) results show a linear behavior in the MP concentration range of 5–50 ng mL−1 with a limit of detection (LOD) of 0.6 ng mL−1 and limit of quantification (LOQ) of 2.0 ng mL−1. Besides, the NPGA+B sensor also revealed excellent selectivity towards MP detection in the presence of other interfering molecules or ions, reproducibility, and repeatability.Fil: Silva Junior, Gilberto J.. Universidade de Sao Paulo; BrasilFil: Selva, Jéssica Soares Guimarães. Universidade de Sao Paulo; BrasilFil: Sukeri, Anandhakumar. Universidade de Sao Paulo; BrasilFil: Gonçalves, Josué Martins. Universidade de Sao Paulo; BrasilFil: Regiart, Daniel Matias Gaston. Universidade de Sao Paulo; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Bertotti, Mauro. Universidade de Sao Paulo; Brasi