199 research outputs found

    Massively parallel pyrosequencing-based transcriptome analyses of small brown planthopper (Laodelphax striatellus), a vector insect transmitting rice stripe virus (RSV)

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    <p>Abstract</p> <p>Background</p> <p>The small brown planthopper (<it>Laodelphax striatellus</it>) is an important agricultural pest that not only damages rice plants by sap-sucking, but also acts as a vector that transmits rice stripe virus (RSV), which can cause even more serious yield loss. Despite being a model organism for studying entomology, population biology, plant protection, molecular interactions among plants, viruses and insects, only a few genomic sequences are available for this species. To investigate its transcriptome and determine the differences between viruliferous and naïve <it>L. striatellus</it>, we employed 454-FLX high-throughput pyrosequencing to generate EST databases of this insect.</p> <p>Results</p> <p>We obtained 201,281 and 218,681 high-quality reads from viruliferous and naïve <it>L. striatellus</it>, respectively, with an average read length as 230 bp. These reads were assembled into contigs and two EST databases were generated. When all reads were combined, 16,885 contigs and 24,607 singletons (a total of 41,492 unigenes) were obtained, which represents a transcriptome of the insect. BlastX search against the NCBI-NR database revealed that only 6,873 (16.6%) of these unigenes have significant matches. Comparison of the distribution of GO classification among viruliferous, naïve, and combined EST databases indicated that these libraries are broadly representative of the <it>L. striatellus </it>transcriptomes. Functionally diverse transcripts from RSV, endosymbiotic bacteria <it>Wolbachia </it>and yeast-like symbiotes were identified, which reflects the possible lifestyles of these microbial symbionts that live in the cells of the host insect. Comparative genomic analysis revealed that <it>L. striatellus </it>encodes similar innate immunity regulatory systems as other insects, such as RNA interference, JAK/STAT and partial Imd cascades, which might be involved in defense against viral infection. In addition, we determined the differences in gene expression between vector and naïve samples, which generated a list of candidate genes that are potentially involved in the symbiosis of <it>L. striatellus </it>and RSV.</p> <p>Conclusions</p> <p>To our knowledge, the present study is the first description of a genomic project for <it>L. striatellus</it>. The identification of transcripts from RSV, <it>Wolbachia</it>, yeast-like symbiotes and genes abundantly expressed in viruliferous insect, provided a starting-point for investigating the molecular basis of symbiosis among these organisms.</p

    Enhancing Literacy Education with Narrative Richness in the Metaverse

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    Through an education-centric metaverse learning application, this research aims to assess the use of narrative richness to deliver media, language, and sustainability literacy education. The 21st-century learning needs require teaching and learning resources to be shared and managed more effectively across institutions. The use of metaverse features can help to manage varying narrative richness to boost learning reflection and attitude. Despite its potential, it is unclear how narrative richness in the metaverse can enhance teaching and learning. The study proposed in this research, which includes institutions from four Asian countries, is driven by this knowledge and evidence gap. Module leaders conceptualize and evaluate a purpose-built metaverse-learning application to produce rich and realistic learning experiences. We utilize narratives to enhance the realism of learning experiences and will assess the effects of narrative richness on learning reflection and attitude

    Research on vibration mechanism and control technology of building structure under earthquake action

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    The large engineering building structures are costly and thus complex to maintain due to their chances of failure under various hazardous conditions. These buildings are needed to be protected against the damage due to the hazards like earthquake, wind, seismic waves, etc. This article focuses on the investigation of vibration mechanism and control strategies for protection of buildings from the hazardous situations. The article presents a robust solution of utilization of magnetorheological dampers for vibration control applications in complex structures. It aims at developing a reliable decentralized model to track and monitor the building structures and control them before the earthquake actions are encountered. This article develops a novel dynamically optimized and decentralized mechanism using the PID controller for the self-regulation of conventional PID controller-based method. The major goal of decentralization is to ensure that each of the subsystem is compatible with one another and can also work independently with a higher efficiency at the time of fault. The combination of decentralization and self-regulation is tested for a tall building structural model with 10 floors. The proposed approach is compared with the conventional PID based mechanism under the faulty condition in order to illustrate its dynamism and usefulness for practical implementation. The proposed simulated model provides 95.54 % earthquake tracking precision and can be used for developing the earthquake protective schemes for the adequate survivability of tall building structures as well as to safeguard the human occupant in it

    The Effect of Zn-Al-Hydrotalcites Composited with Calcium Stearate and β-Diketone on the Thermal Stability of PVC

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    A clean-route synthesis of Zn-Al-hydrotalcites (Zn-Al-LDHs) using zinc oxide and sodium aluminate solution has been developed. The as-obtained materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The effects of metal ions at different molar ratios on the performance of hydrotalcites were discussed. The results showed that the Zn-Al-hydrotalcites can be successfully synthesized at three different Zn/Al ratios of 3:1, 2:1 and 1:1. Thermal aging tests of polyvinyl chloride (PVC) mixed with Zn-Al-LDHs, calcium stearate (CaSt2) and β-diketone were carried out in a thermal aging test box by observing the color change. The results showed that Zn-Al-LDHs can not only enhance the stability of PVC significantly due to the improved capacity of HCl-adsorption but also increase the initial stability and ensure good-initial coloring due to the presence of the Zn element. The effects of various amounts of Zn-Al-LDHs, CaSt2 and β-diketone on the thermal stability of PVC were discussed. The optimum composition was determined to be 0.1 g Zn-Al-LDHs, 0.15 g CaSt2 and 0.25 g β-diketone in 5 g PVC

    The Structural Characterization and Antigenicity of the S Protein of SARS-CoV

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    The corona-like spikes or peplomers on the surface of the virion under electronic microscope are the most striking features of coronaviruses. The S (spike) protein is the largest structural protein, with 1,255 amino acids, in the viral genome. Its structure can be divided into three regions: a long N-terminal region in the exterior, a characteristic transmembrane (TM) region, and a short C-terminus in the interior of a virion. We detected fifteen substitutions of nucleotides by comparisons with the seventeen published SARS-CoV genome sequences, eight (53.3%) of which are non-synonymous mutations leading to amino acid alternations with predicted physiochemical changes. The possible antigenic determinants of the S protein are predicted, and the result is confirmed by ELISA (enzyme-linked immunosorbent assay) with synthesized peptides. Another profound finding is that three disulfide bonds are defined at the C-terminus with the N-terminus of the E (envelope) protein, based on the typical sequence and positions, thus establishing the structural connection with these two important structural proteins, if confirmed. Phylogenetic analysis reveals several conserved regions that might be potent drug targets

    Development and validation of platelet-to-albumin ratio as a clinical predictor for diffuse large B-cell lymphoma

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    IntroductionDiffuse large B-cell lymphoma (DLBCL) is the most common subtypes of lymphoma. Clinical biomarkers are still required for DLBCL patients to identify high-risk patients. Therefore, we developed and validated the platelet-to-albumin (PTA) ratio as a predictor for DLBCL patients.MethodsA group of 749 patients was randomly divided into a training set (600 patients) and an internal validation set (149 cases). The independent cohort of 110 patients was enrolled from the other hospital as an external validation set. Penalized smoothing spline (PS) Cox regression models were used to explore the non-linear relationship between the PTA ratio and overall survival (OS) as well as progression-free survival (PFS), respectively.ResultsA U-shaped relation between the PTA ratio and PFS was identified in the training set. The PTA ratio less than 2.7 or greater than 8.6 was associated with the shorter PFS. Additionally, the PTA ratio had an additional prognostic value to the well-established predictors. What’s more, the U-shaped pattern of the PTA ratio and PFS was respectively validated in the two validation sets.DiscussionA U-shaped association between the PTA ratio and PFS was found in patients with DLBCLs. The PTA ratio can be used as a biomarker, and may suggest abnormalities of both host nutritional aspect and systemic inflammation in DLBCL

    Global climate forcing of aerosols embodied in international trade

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    International trade separates regions consuming goods and services from regions where goods and related aerosol pollution are produced. Yet the role of trade in aerosol climate forcing attributed to different regions has never been quantified. Here, we contrast the direct radiative forcing of aerosols related to regions’ consumption of goods and services against the forcing due to emissions produced in each region. Aerosols assessed include black carbon, primary organic aerosol, and secondary inorganic aerosols, including sulfate, nitrate and ammonium. We find that global aerosol radiative forcing due to emissions produced in East Asia is much stronger than the forcing related to goods and services ultimately consumed in that region because of its large net export of emissions-intensive goods. The opposite is true for net importers such as Western Europe and North America: global radiative forcing related to consumption is much greater than the forcing due to emissions produced in these regions. Overall, trade is associated with a shift of radiative forcing from net importing to net exporting regions. Compared to greenhouse gases such as carbon dioxide, the short atmospheric lifetimes of aerosols cause large localized differences between consumption- and production-related radiative forcing. International efforts to reduce emissions in the exporting countries will help alleviate trade-related climate and health impacts of aerosols while lowering global emissions

    Transboundary health impacts of transported global air pollution and international trade

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    Millions of people die every year from diseases caused by exposure to outdoor air pollution1, 2, 3, 4, 5. Some studies have estimated premature mortality related to local sources of air pollution6, 7, but local air quality can also be affected by atmospheric transport of pollution from distant sources8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18. International trade is contributing to the globalization of emission and pollution as a result of the production of goods (and their associated emissions) in one region for consumption in another region14, 19, 20, 21, 22. The effects of international trade on air pollutant emissions23, air quality14 and health24 have been investigated regionally, but a combined, global assessment of the health impacts related to international trade and the transport of atmospheric air pollution is lacking. Here we combine four global models to estimate premature mortality caused by fine particulate matter (PM2.5) pollution as a result of atmospheric transport and the production and consumption of goods and services in different world regions. We find that, of the 3.45 million premature deaths related to PM2.5 pollution in 2007 worldwide, about 12 per cent (411,100 deaths) were related to air pollutants emitted in a region of the world other than that in which the death occurred, and about 22 per cent (762,400 deaths) were associated with goods and services produced in one region for consumption in another. For example, PM2.5 pollution produced in China in 2007 is linked to more than 64,800 premature deaths in regions other than China, including more than 3,100 premature deaths in western Europe and the USA; on the other hand, consumption in western Europe and the USA is linked to more than 108,600 premature deaths in China. Our results reveal that the transboundary health impacts of PM2.5 pollution associated with international trade are greater than those associated with long-distance atmospheric pollutant transport
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