211 research outputs found

    Sustainable high strength steel flush end plate beam-tocolumn composite joints with deconstructable bolted shear connectors

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    The design of engineering structures for deconstructability can reduce the energy and cost required for their demolition and the disposal of their construction waste, and it also enhances the sustainability of a building by allowing for easy dismantling and the reuse or recycling of structural components and construction materials at the end of the service life of the building. In addition, using high performance materials such as High Strength Steel (HSS) can improve the sustainability of a structure by providing for higher design stresses and accordingly reducing the self-weight of the structure. This paper describes the results of four full-scale beam-to-column deconstructable composite joints with HSS S690 flush end plates. The structural behaviour of the new system in conjunction with application of post-installed friction-grip bolted shear connectors for developing deconstructable composite floors is investigated. The test results show that the proposed composite beam-tocolumn joints can provide the required strength and ductility according to EC3 and EC4 specifications, and that the system can be easily deconstructed at the end of the service life of the structure as a proof of concept

    Study of clonal variation of 'Bidaneh Ghermez' grapevine cultivar in Iran

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    ArticleGrapevine (Vitis vinifera L.) is a well - known plant including different cultivars and clones. In spite of the extensive works at the cultivar level, identification and determination of clonal genetic variation has remained as a challenge. To assess the genetic variation between clones of grapevine cv. 'Bidaneh Ghermez', 20 selected clones were analyzed for cluster weight (CW), cluster length (CL), cluster width (CWI), berry weight (BW), berry length (BL), berry width (BWI) and total soluble solids (TSS) in randomized complete block design with three replications. Analysis of variance reveale d considerable genetic variation for all measured traits (except cluster width) among clones. Cluster analysis, discriminant function analysis and principal component analysis (PCA) showed same results and all clones assigned in 2 groups. First group was including 9 clones and second group was including 11 clones. Overall, our results indicated C7, C10, C12 and C14 clones were best clones and have potential to introduce promising clones for stablishing new vineyard with high yield

    Drug-related mutational patterns in hepatitis B virus (HBV) reverse transcriptase proteins from Iranian treatment-Naïve chronic HBV patients

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    Background: Immunomodulators and Nucleotide analogues have been used globally for the dealing of chronic hepatitis B virus (HBV) infection. However, the development of drug resistance is a major limitation to their long-term effectiveness. Objectives: The aim of this study was to characterize the hepatitis B virus reverse transcriptase (RT) protein variations among Iranian chronic HBV carriers who did not receive any antiviral treatments. Materials and Methods: Hepatitis B virus partial RT genes from 325 chronic in active carrier patients were amplified and directly sequenced. Nucleotide/amino acid substitutions were identified compared to the sequences obtained from the database. Results: All strains belonging to genotype D.365 amino-acid substitutions were found. Mutations related to lamivudine, adefovir, telbivudine, and entecavir occurred in (YMDD) 4% (n = 13), (SVQ) 17.23% (n = 56), (M204I/V + L180M) 2.45% (n = 8) and (M204I) 2.76% (n = 9) of patients, respectively. Conclusions: RT mutants do occur naturally and could be found in HBV carriers who have never received antiviral therapy. However, mutations related to drug resistance in Iranian treatment-naïve chronic HBV patients were found to be higher than other studies published formerly. Chronic HBV patients should be monitored closely prior the commencement of therapy to achieve the best regimen option. © 2013, KOWSAR Corp

    The association between common C677T mutation in methylenetetrahydrofolate reductase gene and the risk of venous thrombosis in an Iranian population

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    Background: Venous thrombosis is a multicausal disease involving acquired and genetic factors. The prevalence of methylenetetrahydrofolate reductase (MTHFR) C677T genotypes and its association with venous thrombosis is not established in the Iranian population. In this study we investigated a possible association between fasting hyperhomocysteinemia and C677T mutation in the MTHFR gene with venous thrombosis. Materials and Methods: We studied 200 venous thrombotic patients and 100 healthy controls, of similar age and sex. Mutation analysis was carried out by PCR-RFLP, and the homocysteine level was measured by EIA. Results: No significant differences in the frequency of C677T genotypes were observed between patients and controls (P=0.2). The frequency of the T allele was 21 and 27.2 in controls and patients, respectively (odds ratio, 1.27; 95 CI, 0.83-1.94, P=0.15). Fasting homocysteine level was significantly higher in patients than controls (P=0.001). Conclusions: We concluded that hyperhomocysteinemia, but not MTHFR C677T mutation, is a significant risk factor for venous thrombosis in the Iranian population, and measuring the level of homocysteine is less expensive and more useful than the genetic test for the MTHFR mutation

    Presence and diversity of Leishmania RNA virus in an old zoonotic cutaneous leishmaniasis focus, northeastern Iran: haplotype and phylogenetic based approach

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    Objective: Leishmania RNA virus (LRV) is a double-stranded RNA (dsRNA) virus that circulates within many species of the Leishmania parasite. In this study, we aimed to investigate the presence of LRV2 circulating in Leishmania isolates in an old focus of ZCL located in northeastern of Iran. Methods: Leishmania isolates were collected from 85 patients that confirmed to have cutaneous leishmaniasis (CL) based on parasitological examination. To identify the Leishmania isolates, species-specific primer sets were applied for molecular identification. The presence of LRV2 was performed by RdRp-semi nested-PCR. The genetic diversity were calculated using MEGA and DnaSP. To assess haplotype diversity, 31 LRV2 strains in different regions were surveyed using analysis a 292-bp section of the RdRp sequences. Results: Out of 85 patients, 83 (97.6 ) were diagnosed with L. major and 2 (2.4 ) with L. tropica. LRV2 virus was detected in 59 (69.4) of the CL cases. For the first time, LRV2 was reported in one L. tropica strain in Iran. The current LRV2 sequences indicated the highest similarities to an Old World LRV2. Moreover, 10 unique haplotypes were identified based on the analyzed sequences of the RdRp gene. Conclusions: Our results indicated the highest occurrence of Leishmania/LRV2 co-circulation in this known ZCL focus from northeastern Iran. Phylogenetic analyses of LRV2 sequences confirmed that these isolates belong to the order of LRV2 from the Old World. This study offered an insight into LRV2 haplotype that the informative issue can be used for genetic research of LRV2 in other regions. © 2020 The Author(s

    Sowing the wheat seeds of Afghanistan's future

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    Societal Impact Statement: The production and availability of food underpins societal stability. In Afghanistan, wheat is the major arable agricultural crop and source of dietary energy. The withdrawal of NATO allies and partner countries from Afghanistan presents numerous well‐documented societal and political challenges and has impacts on immediate and longer‐term food security. Conflict‐impacted irrigation infrastructure coupled with growing climate instability have also contributed markedly to reductions in current food, and specifically wheat, production. Here, we review the status of Afghan wheat improvement and propose a research agenda to support the regeneration of Afghanistan's wheat and agricultural sector. Summary: Afghanistan is a country with diverse natural ecologies in a largely arid and mountainous region. The rural sector is still considered to drive economic potential. Current social, political and economic instability along with climatic challenges are driving food and water insecurity in the wider region. In the short term, it is likely that this and the associated challenges of displacement and unemployment can only be addressed by humanitarian intervention and agrifood and nutrition support. In the medium to long term, drought, and heat, probably linked to climate change, will pose recurrent challenges for agriculture and food security that will require a much broader set of interventions to secure the rural population's livelihoods. The genetic gap, among other major challenges, must be addressed if Afghanistan is to develop its agricultural potential leading to income and livelihood improvements for farmers and stable and accessible supplies for consumers. Only thereby will the country be enabled to reap the important and long‐sought trade and food security benefits derived from self‐sufficiency. Here, we highlight the agricultural challenges facing Afghanistan and propose forward strategies for ensuring the future stability of wheat production, the cornerstone of Afghan agriculture

    Plant breeding increases spring wheat yield potential in Afghanistan

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    Wheat (Triticum aestivum L.) is an essential food security crop in Afghanistan. To determine the contribution of wheat breeding to increasing productivity, we analyzed data obtained from 192 trials conducted over 11 locations from 2002–2003 to 2015–2016. Using this data, we estimated annual genetic gains for grain yield, days to heading and plant height over the 14-yr period. We used best linear unbiased estimates to measure genetic gains across CIMMYT Elite Spring Wheat Yield Trials per se and for the top 5 and top 10% performing genotypes relative to checks. Mean realized genetic gain for grain yield was 115 kg ha–1 yr−1, whereas the top 10 genotypes achieved annual yield gains of 123 kg ha–1. The continually replaced local check. s also contributed an annual genetic gain for yield of 107 kg ha–1. The associated adaptive traits days to heading and plant height varied in their response over time with the top 10 yielding genotypes having a 1.82 d annual reduction in heading date while plant height increased by 0.77 cm yr−1 for the same set of genotypes. Results show that continual breeding improvements confer yield gains, contributing to increasing Afghan wheat productivity. This has wider relevance for demonstrating the value of continued investment in public sector plant breeding supporting wheat production and food security in Central Asia
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