515 research outputs found

    Effect of 28-homobrassinolide on the nitrate reductase, carbonic anhydrase activities and net photosynthetic rate in Vigna radiata

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    The foliage of fifteen day-old Vigna radiata seedlings was sprayed with water (control) or with a 10–10 M, 10–8Mor 10–6 Maqueous solution of 28-homobrassinolide (HBR). Samples of the treated plant material, collected at 30/50 days after sowing (DAS), were assessed for the activities of carbonic anhydrase (CA) and nitrate reductase (NR); leaf chlorophyll content (Chl); stomatal conductance (gs); carboxylation efficiency (CE), and net photosynthetic rate (PN). 28-homobrassinolide generated a significant impact on all these characteristics and on seed yield at harvest. Among the treatments, 10–8Mproved best, in which case the values for the above six physiological parameters in 30 days-old plants increased by, respectively, 31, 29, 27, 28, 29 and 33% over the control. Moreover, the harvest weight of the seeds of these plants was 27% larger than in the control

    Lab scale studies on water hyacinth (Eichhornia crassipes Marts Solms) for biotreatment of textile wastewater

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    Textile wastewater contains substantial pollution loads in terms of Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), Total Dissolved Solids (TDS) and heavy metals. Phytoremediation used for removing heavy metals and other pollutants by aquatic macrophytes treatment systems (AMATS) is well established environmental protective technique. A lab scale study was conducted to test the feasibility of water hyacinth for treating textile wastewater. The pH was reduced from alkaline to nearly neutral in all cases studied with the introduction of water hyacinth. The maximum reduction in the conductivity was 55.71% while the BOD and COD reduction ranged from 40 to 70%. A great deal of reduction in the total solids was noted in all the waste samples with a maximum reduction of 50.64%. Water hyacinth has tremendous potential to absorb heavy metals from the textile wastewater as it resulted in 94.78% reduction of chromium, 96.88% in zinc and 94.44 % reduction in copper. ANOVA showed a significant (p<0.05) reduction in all the pollutants with the passage of time. Thus water hyacinth can be an efficient biological agent in reducing the pollution loads in textile industry wastewater

    Photoluminescence revealed higher order plasmonic resonance modes and their unexpected frequency blue shifts in silver-coated silica nanoparticle antennas

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    © 2019 by the authors. Higher order plasmonic resonance modes and their frequency blue shifts in silver-coated silica nanoparticle antennas are studied. Synthesizing them with a wet chemistry method, silica (SiO2) nanoparticles were enclosed within silver shells with different thicknesses. A size-dependent Drude model was used to model the plasmonic shells and their optical losses. Two higher order plasmonic resonances were identified for each case in these simulations. The photoluminescence spectroscopy (PL) experimental results, in good agreement with their simulated values, confirmed the presence of those two higher order resonant modes and their resonance frequencies. When compared with pure metallic Ag nanoparticles, size-induced blue shifts were observed in these resonance frequencies

    Response of Poaceous Weeds in Wheat to Post-Emergence Herbicides

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    Poaceous weeds are prolific and competitive in winter crops, but they are more insidious in wheat due to their similar morphology and growing requirements. Herbicides are effective and efficient tools of weed management, however, they are vulnerable to resistance, and herbicides with different modes of action might check the dominance of a particular weed flora. The current study was undertaken to see the response of three poaceous weeds viz., Phalaris minor, Avena fatua and Lolium temulentum, to herbicides Isoproturon, Topik (Clodinafop-p) and Puma Super (Fenoxaprop-p). Completely randomized design with two factor treatments (weeds, herbicides) and eight replications was employed. Data were recorded on chlorotic and necrotic effects of herbicides on weeds, and percent mortality at the time interval of 14, 21 and 28 days after the application of herbicides. Dry biomass weight of weeds was recorded at 30 days after the treatments. Results indicated that all the parameters were affected significantly over the period of time. Maximum counts of chlorotic (2.16) and necrotic (2.97) weeds were observed at the 21st day of treatment. The highest mortality (31.1 %) was recorded at 21st day after the application of herbicides. Phalaris minor was the most resistant weed to herbicides showing the lowest mortality (only 17.7 %) compared to other two weeds. Maximum dry weight of weeds was recorded in control while a minimum of 0.456 g dry weight was observed where Topik (Clodinafop-p) was applied. For the effective control of P. minor, A. fatua and L. temulentum weeds in wheat crop, Topik (15 WP) @ 0.37 kg a.i. ha-1 was proved to be the most suitable herbicide applied at 3-4 foliar stage

    Identification of genes required for soil survival in Burkholderia thailandensis by transposon-directed insertion site sequencing.

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    Transposon-directed insertion site sequencing was used to identify genes required by Burkholderia thailandensis to survive in plant/soil microcosms. A total of 1,153 genetic loci fulfilled the criteria as being likely to encode survival characteristics. Of these, 203 (17.6 %) were associated with uptake and transport systems; 463 loci (40.1 %) coded for enzymatic properties, 99 of these (21.4 %) had reduction/oxidation functions; 117 (10.1 %) were gene regulation or sensory loci; 61 (5.3 %) encoded structural proteins found in the cell envelope or with enzymatic activities related to it, distinct from these, 46 (4.0 %) were involved in chemotaxis and flagellum, or pilus synthesis; 39 (3.4 %) were transposase enzymes or were bacteriophage-derived; and 30 (2.6 %) were involved in the production of antibiotics or siderophores. Two hundred and twenty genes (19.1 %) encoded hypothetical proteins or those of unknown function. Given the importance of motility and pilus formation in microcosm persistence the nature of the colonization of the rhizosphere was examined by confocal microscopy. Wild type B. thailandensis expressing red fluorescent protein was inoculated into microcosms. Even though the roots had been washed, the bacteria were still present but they were motile with no attachment having taken place, perhaps being retained in a biofilm

    Predicting Transcriptional Activity of Multiple Site p53 Mutants Based on Hybrid Properties

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    As an important tumor suppressor protein, reactivate mutated p53 was found in many kinds of human cancers and that restoring active p53 would lead to tumor regression. In this work, we developed a new computational method to predict the transcriptional activity for one-, two-, three- and four-site p53 mutants, respectively. With the approach from the general form of pseudo amino acid composition, we used eight types of features to represent the mutation and then selected the optimal prediction features based on the maximum relevance, minimum redundancy, and incremental feature selection methods. The Mathew's correlation coefficients (MCC) obtained by using nearest neighbor algorithm and jackknife cross validation for one-, two-, three- and four-site p53 mutants were 0.678, 0.314, 0.705, and 0.907, respectively. It was revealed by the further optimal feature set analysis that the 2D (two-dimensional) structure features composed the largest part of the optimal feature set and maybe played the most important roles in all four types of p53 mutant active status prediction. It was also demonstrated by the optimal feature sets, especially those at the top level, that the 3D structure features, conservation, physicochemical and biochemical properties of amino acid near the mutation site, also played quite important roles for p53 mutant active status prediction. Our study has provided a new and promising approach for finding functionally important sites and the relevant features for in-depth study of p53 protein and its action mechanism

    A Novel Role for the Centrosomal Protein, Pericentrin, in Regulation of Insulin Secretory Vesicle Docking in Mouse Pancreatic β-cells

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    The centrosome is important for microtubule organization and cell cycle progression in animal cells. Recently, mutations in the centrosomal protein, pericentrin, have been linked to human microcephalic osteodysplastic primordial dwarfism (MOPD II), a rare genetic disease characterized by severe growth retardation and early onset of type 2 diabetes among other clinical manifestations. While the link between centrosomal and cell cycle defects may account for growth deficiencies, the mechanism linking pericentrin mutations with dysregulated glucose homeostasis and pre-pubertal onset of diabetes is unknown. In this report we observed abundant expression of pericentrin in quiescent pancreatic β-cells of normal animals which led us to hypothesize that pericentrin may have a critical function in β-cells distinct from its known role in regulating cell cycle progression. In addition to the typical centrosome localization, pericentrin was also enriched with secretory vesicles in the cytoplasm. Pericentrin overexpression in β-cells resulted in aggregation of insulin-containing secretory vesicles with cytoplasmic, but not centrosomal, pericentriolar material and an increase in total levels of intracellular insulin. RNAi- mediated silencing of pericentrin in secretory β-cells caused dysregulated secretory vesicle hypersecretion of insulin into the media. Together, these data suggest that pericentrin may regulate the intracellular distribution and secretion of insulin. Mice transplanted with pericentrin-depleted islets exhibited abnormal fasting hypoglycemia and inability to regulate blood glucose normally during a glucose challenge, which is consistent with our in vitro data. This previously unrecognized function for a centrosomal protein to mediate vesicle docking in secretory endocrine cells emphasizes the adaptability of these scaffolding proteins to regulate diverse cellular processes and identifies a novel target for modulating regulated protein secretion in disorders such as diabetes

    Real-Time PCR Improves Helicobacter pylori Detection in Patients with Peptic Ulcer Bleeding

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    Background and aims: Histological and rapid urease tests to detect H. pylori in biopsy specimens obtained during peptic ulcer bleeding episodes (PUB) often produce false-negative results. We aimed to examine whether immunohistochemistry and real-time PCR can improve the sensitivity of these biopsies. Patients and Methods: We selected 52 histology-negative formalin-fixed paraffin-embedded biopsy specimens obtained during PUB episodes. Additional tests showed 10 were true negatives and 42 were false negatives. We also selected 17 histology-positive biopsy specimens obtained during PUB to use as controls. We performed immunohistochemistry staining and real-time PCR for 16S rRNA, ureA, and 23S rRNA for H. pylori genes on all specimens. Results: All controls were positive for H. pylori on all PCR assays and immunohistochemical staining. Regarding the 52 initially negative biopsies, all PCR tests were significantly more sensitive than immunohistochemical staining (p<0.01). Sensitivity and specificity were 55% and 80% for 16S rRNA PCR, 43% and 90% for ureA PCR, 41% and 80% for 23S rRNA PCR, and 7% and 100% for immunohistochemical staining, respectively. Combined analysis of PCR assays for two genes were significantly more sensitive than ureA or 23S rRNA PCR tests alone (p<0.05) and marginally better than 16S rRNA PCR alone. The best combination was 16S rRNA+ureA, with a sensitivity of 64% and a specificity of 80%. Conclusions: Real-time PCR improves the detection of H. pylori infection in histology-negative formalin-fixed paraffin-embedded biopsy samples obtained during PUB episodes. The low reported prevalence of H. pylori in PUB may be due to the failure of conventional tests to detect infection

    Seismic risk assessment for developing countries : Pakistan as a case study

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    Modern Earthquake Risk Assessment (ERA) methods usually require seismo-tectonic information for Probabilistic Seismic Hazard Assessment (PSHA) that may not be readily available in developing countries. To bypass this drawback, this paper presents a practical event-based PSHA method that uses instrumental seismicity, available historical seismicity, as well as limited information on geology and tectonic setting. Historical seismicity is integrated with instrumental seismicity to determine the long-term hazard. The tectonic setting is included by assigning seismic source zones associated with known major faults. Monte Carlo simulations are used to generate earthquake catalogues with randomized key hazard parameters. A case study region in Pakistan is selected to demonstrate the effectiveness of the method. The results indicate that the proposed method produces seismic hazard maps consistent with previous studies, thus being suitable for generating such maps in regions where limited data are available. The PSHA procedure is developed as an integral part of an ERA framework named EQRAM. The framework is also used to determine seismic risk in terms of annual losses for the study region
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