733 research outputs found
Mixed Infection of Hard Red Winter Wheat with High Plains Virus and Wheat Streak Mosaic Virus from Wheat Curl Mites in Nebraska
A new disease of wheat and corn caused by the High Plains virus (HPV) has been observed in the High Plains region of western United States. HPV is transmitted by the wheat curl mite, Aceria tosichella, which is also the vector of wheat streak mosaic virus (WSMV). In the field it is extremely difficult to visually differentiate plants infected with WSMV from those with HPV. An indirect protein-A sandwich enzyme-linked immunosorbent assay (PAS-ELISA) and Western blot analysis were used to identify WSMV and HPV. Samples of wheat curl mites were collected from arbitrarily chosen sites from commercial wheat plantings in 1995 and 1996 and used to infest caged wheat plants. After 3 weeks, leaf samples were harvested and assayed. Both Western blot analysis and PAS-ELISA were effective at identifying samples positive for WSMV and HPV, both alone and in mixed infections. Western blot results showed that over the 2 years, 65% of the samples were positive for WSMV, 46% were positive for HPV, and mixed infections were found in 40% of the samples. HPV presence was verified with similar results from field collected plant samples. These levels of virus indicate an unexpectedly high incidence of HPV in wheat curl mite populations in Nebraska
Linear and non-linear regression analysis for the sorption kinetics of Rhodamine dye from aqueous solution using Chitosan-Jackfruit nanocomposite
This paper presents experimental results such as the adsorbate-adsorbent chemical properties and chemical interaction as well as adsorption conditions. The experimental results were fitted to batch kinetic studies to obtain the characteristic parameters of each model. According to the evaluation using the Kinetic equation, the maximum sorption capacity at dye concentration was 19.6 (mg g-1), pH 11.6 (mg g-1) and temperature 24.2 (mg g-1) Rhodamine dye were investigated. For all of the systems studied, the pseudo-first-order and pseudo-second-order model provided the best correlation of the kinetic experimental data. The results revealed that with increasing temperature and decreasing pH, ionic strength, and adsorbate concentration, dye removal efficiency has increased. Chitosan-Jackfruit nanocomposite could remove 90.2% dye from the solution containing 40 mg/L dye at 100 min. The results indicated that dye removal followed pseudo-second-order kinetic (R2>0.99). According to the findings, Chitosan-Jackfruit nanocomposites an effective adsorbent for direct dye removal from wastewater
Synthesis of Iron Oxide Magnetic Nanoparticles: Characterization and its Biomedical Application
In the present time, Iron oxide magnetic nanoparticles (IOMNPs) have paid considerable attention due to their exclusive applications in terms of surface-to-volume ratio, superparamagnetism, high surface area, biosensor, bio-separation, catalysis, and biomedicine. Our goal was to synthesis iron oxide magnetic nanoparticles by chemical route technique. The preparation method had a very large effect on the size, shape, and surface chemistry of the magnetic nanoparticles including their applications. The iron chloride solution was prepared by mixing deionized water with iron chloride tetrahydrate. The synthesized powder was characterized by XRD, UV-vis, SEM, FT-IR, DLS, FL, and TGA techniques. Moreover, antibacterial activity was evaluated using the synthesized IOMNPs against Escherichia coli (A), Pseudomonas (B), Enterobacter (C), Staphylococcus aureus (D), and Bacillus subtilis (E) in the concentration of 0.1 mg and 0.5 mg. The results showed that Bacillus subtilis possess a higher antibacterial activity at the concentration of 0.5 mg comparing the other bacterial species. The outcome of this work would contribute to the present understanding of the biomedical application with the obtained size, shape, and synthesized method
Green Synthesis and Characterization of Antibacterial Studies by Iron Oxide Nanoparticles using Carica papaya Leaf Extract
In present years, the synthesis of iron oxide nanoparticles (IONPs) has established excessive potential in biological applications due to their non-toxic role in biological systems, biocompatibility, and biodegradability. Ongoing research efforts focused on IONPs in the expansion of novel technologies as they can be synthesized with surface modification. Here we have studied the antibacterial effects of IONPs which were synthesized effectively through a green synthesis route by using leaf extract of the Carica papaya plant. The formation of IONPs was confirmed by the color change. The crystallinity of IONPs was determined by XRD and the morphology by using SEM, which showed spherical particles of well-dispersed size. The absorption peak was determined by UVâvis spectroscopy at 390 nm. Average particle size distribution was obtained at 56 nm using PSA. FL spectroscopy indicated the higher emission wavelength by redshift at 641.6 nm. TGA showed that the IONPs are thermally stable up to 200â°C with no decomposition. The outcome would pave a way for utilizing IONPs for better biomedical application
Synthesis and Characterization of Silver Nanoparticles from Ashyranthus aspera Extract for Antimicrobial Activity Studies
Development of biologically inspired experimental processes for the
synthesis of nanoparticles is evolving into an important branch of
nanotechnology. Plant-mediated synthesis of nanomaterials has been
increasingly gaining popularity due to its eco-friendly nature and
cost-effectiveness. In the present study, we were synthesized silver
(Ag) nanoparticles using aqueous extracts of fresh leaves of
Ashyranthus aspera medicinal plants as bio-reducing agents. UV-Vis
spectrometer used to monitor the reduction of Ag ions and the formation
of AgNPs in the medium. UV-Vis spectra and visual observation showed
that the color of the fresh leaf extracts of Ashyranthus aspera turned
into grayish-brown respectively, after treatment with Ag precursors.
XRD and SEM have been used to investigate the morphology of prepared
AgNPs. The peaks in the XRD pattern are associated with that of the
Face-Centered-Cubic (FCC) form of metallic silver. TGA/DTA results
associated with weight loss and exothermic reaction due to the
desorption of chemisorbed water. FTIR was performed to identify the
functional groups which form a layer covering AgNPs and stabilize the
AgNPs in the medium. Moreover, silver nanoparticles using aqueous leaf
extracts of Ashyranthus aspera were separately tested for their
antibacterial activity against Gram-positive bacteria ( Staphylococcus
aureus ) and Gram-negative bacteria ( Enterobacter ). The results
showed that the bacterial growth was inhibited by the extracts
containing AgNPs Nanoparticles. The biosynthesized nanoparticle was
prepared from Ashyranthus aspera leaf extracts exhibits potential
applications as broad-spectrum antimicrobial agents
From dwindling ice to headwater lakes: could dams replace glaciers in the European Alps?
The potential exploitation of areas becoming ice-free in response to ongoing climate change has rarely been addressed, although it could be of interest from the water management perspective. Here we present an estimate for the potential of mitigating projected changes in seasonal water availability from melting glaciers by managing runoff through reservoirs. For the European Alps we estimate that by the end of the century, such a strategy could offset up to 65% of the expected summer-runoff changes from presently glacierized surfaces. A first-order approach suggests that the retention volume potentially available in the areas becoming deglacierized is in excess of the volume required for achieving the maximal possible mitigation by more than one order of magnitude. Obviously, however, such a strategy cannot compensate for the reduction in annual runoff caused by glacier ice depletion. Our estimates indicate that by 2070â2099, 0.73 ± 0.67 km3 aâ1 of this non-renewable component of the water cycle could be missing in Alpine water supplies
Pricing Rainfall Based Futures Using Genetic Programming
Rainfall derivatives are in their infancy since starting trading on the Chicago Mercantile Exchange (CME) since 2011. Being a relatively new class of financial instruments there is no generally recognised pricing framework used within the literature. In this paper, we propose a novel framework for pricing contracts using Genetic Programming (GP). Our novel framework requires generating a risk-neutral density of our rainfall predictions generated by GP supported by Markov chain Monte Carlo and Esscher transform. Moreover, instead of having a single rainfall model for all contracts, we propose having a separate rainfall model for each contract. We compare our novel framework with and without our proposed contract-specific models for pricing against the pricing performance of the two most commonly used methods, namely Markov chain extended with rainfall prediction (MCRP), and burn analysis (BA) across contracts available on the CME. Our goal is twofold, (i) to show that by improving the predictive accuracy of the rainfall process, the accuracy of pricing also increases. (ii) contract-specific models can further improve the pricing accuracy. Results show that both of the above goals are met, as GP is capable of pricing rainfall futures contracts closer to the CME than MCRP and BA. This shows that our novel framework for using GP is successful, which is a significant step forward in pricing rainfall derivatives
Is the internet the right medium for a 'don't quit campaign'?
This paper examines the effectiveness of promoting post-16 education and training via Internet. It examines the differences between those who intend to continue the post-16 schooling and those who do not. The implication of the findings challenges the
effectiveness of a 'don't quit campaign' which was to offer support and guidance on the choice of post 16 options. This study found that the campaign has done very little for those who decided not to continue post-16 education. Consequently, disadvantaged young people need constant support and resources to eliminate the disparities between different groups
He Scores Through a Screen: Mediating Masculinities Through Hockey Video Games
Hockey video games highlight the ways in which the video game medium shapes and conditions the experience of producing and/or performing the sport âin real life.â Indeed, the accumulation of advanced statistics in and through the constant evaluation, measurement, and surveillance which are inherent to video gamesâand increasingly seen as foundational for sportâreveals important contradictions not only in the way the embodied sport is played and understood, but also in terms of the proofs of masculinity upon which the sport is built. It then becomes clear that the building of masculinity and the empowerment of the character become one and the same. The ludic function reinforces the cultural imperative and vice versa. Thus, our chapter prizes apart the conflation of masculinity with hockey while showing the ways that video game studies can contribute to existing disciplines
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