240 research outputs found

    Detection of eight different tospovirus species by a monoclonal antibody against the common epitope of NSs protein

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    Rabbit antisera against the nucleocapsid protein (NP) have been commonly used for detection of tospoviruses and classification into serogroups or serotypes. Mouse monoclonal antibodies (MAbs) with high specificity to the NPs have also been widely used to identify tospovirus species. Recently, a serogroup-specific MAb against the NSs protein of Watermelon silver mottle virus (WSMoV) was produced by our laboratory to react with five members of WSMoV serogroup, i.e., WSMoV, Capsicum chlorosis virus (CaCV), Calla lily chlorotic spot virus (CCSV), Peanut bud necrosis virus (PBNV) and Watermelon bud necrosis virus (WBNV). The epitope recognized by the NSs MAb was determined and the comparison with the reported sequences of tospoviral NSs proteins revealed that the epitope is highly conserved at the N-terminal region of NSs proteins among members of WSMoV and Iris yellow spot virus (IYSV) serogroups, and Melon yellow spot virus (MYSV) serotype. When the NSs MAb was further used to react with the crude antigens of MYSV serotype, IYSV and Tomato yellow ring virus (TYRV) of IYSV serogroup, strong serological reactions, both in ELISA and western blotting, were observed. Thus, our results indicated that the NSs MAb is a useful and convenient tool for detection of the eight tospovirus species. It is also suggested that these eight Asian-type tospoviruses, i.e., WSMoV, CaCV, CCSV, PBNV, WBNV, MYSV, IYSV and TYRV, may share a common evolutionary ancesto

    Analysis of the Tomato spotted wilt virus Ambisense S RNA-Encoded Hairpin Structure in Translation

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    Background: The intergenic region (IR) of ambisense RNA segments from animal- and plant-infecting (-)RNA viruses functions as a bidirectional transcription terminator. The IR sequence of the Tomato spotted wilt virus (TSWV) ambisense S RNA contains stretches that are highly rich in A-residues and U-residues and is predicted to fold into a stable hairpin structure. The presence of this hairpin structure sequence in the 39 untranslated region (UTR) of TSWV mRNAs implies a possible role in translation. Methodology/Principal Findings: To analyse the role of the predicted hairpin structure in translation, various Renilla luciferase constructs containing modified 39 and/or 59 UTR sequences of the TSWV S RNA encoded nucleocapsid (N) gene were analyzed for expression. While good luciferase expression levels were obtained from constructs containing the 59 UTR and the 39 UTR, luciferase expression was lost when the hairpin structure sequence was removed from the 39 UTR. Constructs that only lacked the 59 UTR, still rendered good expression levels. When in addition the entire 39 UTR was exchanged for that of the S RNA encoded non-structural (NSs) gene transcript, containing the complementary hairpin folding sequence, the loss of luciferase expression could only be recovered by providing the 59 UTR sequence of the NSs transcript. Luciferase activity remained unaltered when the hairpin structure sequence was swapped for the analogous one from Tomato yellow ring virus, another distinct tospovirus. The addition of N and NSs proteins further increased luciferas

    Functional replacement of the endogenous tyrosyl-tRNA synthetase–tRNATyr pair by the archaeal tyrosine pair in Escherichia coli for genetic code expansion

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    Non-natural amino acids have been genetically encoded in living cells, using aminoacyl-tRNA synthetase–tRNA pairs orthogonal to the host translation system. In the present study, we engineered Escherichia coli cells with a translation system orthogonal to the E. coli tyrosyl-tRNA synthetase (TyrRS)–tRNATyr pair, to use E. coli TyrRS variants for non-natural amino acids in the cells without interfering with tyrosine incorporation. We showed that the E. coli TyrRS–tRNATyr pair can be functionally replaced by the Methanocaldococcus jannaschii and Saccharomyces cerevisiae tyrosine pairs, which do not cross-react with E. coli TyrRS or tRNATyr. The endogenous TyrRS and tRNATyr genes were then removed from the chromosome of the E. coli cells expressing the archaeal TyrRS–tRNATyr pair. In this engineered strain, 3-iodo-l-tyrosine and 3-azido-l-tyrosine were each successfully encoded with the amber codon, using the E. coli amber suppressor tRNATyr and a TyrRS variant, which was previously developed for 3-iodo-l-tyrosine and was also found to recognize 3-azido-l-tyrosine. The structural basis for the 3-azido-l-tyrosine recognition was revealed by X-ray crystallography. The present engineering allows E. coli TyrRS variants for non-natural amino acids to be developed in E. coli, for use in both eukaryotic and bacterial cells for genetic code expansion

    Scientific opinion on the pest categorization of the tospovirus

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    The European Commission requested EFSA’s Panel on Plant Health to perform the pest categorisation for the 24 viruses of the Tospovirus genus for the EU territory. The following tospoviruses were analysed: Tomato spotted wilt virus (TSWV), Impatiens necrotic spot virus (INSV), Iris yellow spot virus (IYSV), Polygonum ringspot virus (PolRSV), Groundnut ringspot virus (GRSV), Tomato chlorotic spot virus (TCSV), Alstroemeria necrotic streak virus (ANSV), Chrysanthemum stem necrosis virus (CSNV), Melon severe mosaic virus (MSMV), Tomato yellow (fruit) ring virus (TYRV), Tomato zonate spot virus (TZSV), Groundnut yellow spot virus (GYSV), Groundnut chlorotic fan-spot virus (GCFSV), Groundnut bud necrosis virus (GBNV), Zucchini lethal chlorosis virus (ZLCV), Capsicum chlorosis virus (CaCV), Watermelon bud necrosis virus (WBNV), Watermelon silver mottle virus (WSMoV), Tomato necrotic ringspot virus (TNRV), Calla lily chlorotic spot virus (CCSV), Melon yellow spot virus (MYSV), Soybean vein necrosis associated virus (SVNaV), Bean necrotic mosaic virus (BeNMV) and Pepper necrotic spot virus (PNSV). In reaching its conclusions, the Panel considered four parameters to be of critical importance in the risk assessment area: (i) the presence of a tospovirus, (ii) the existence of host plants, (iii) the existence of thrips vector species and (iv) the potential for damage to crops grown in Europe. Based on its analysis, the Panel concluded that the 24 viruses analysed could be allocated to four different risk groups. Seven viruses (GRSV, TCSV, ANSV, CSNV, MSMV, TYRV, TZSV) for which both thrips species vectors and natural or experimental hosts crops are present in the EU territory were considered by the Panel to represent the highest risk to the EU territory. In contrast, three viruses (INSV, IYSV and PolRSV) already present in the risk assessment area were not considered by the Panel to pose a risk justifying the development of full risk assessments

    Mobile devices usage in retail setting: Gender and generation preferences

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    Purpose: The tendency shows that more customers will bring and use their mobile devices in-store. This study proposes a further analysis of the complementary role of the mobile device in an in-store purchase providing a characterisation of those customers and analyses their usage preferences and behaviour intentions, presenting new insights concerning gender and generation preferences. Design/methodology/approach: Quantitative research with customers of electronic stores was conducted based on a questionnaire applied at the store’s exit. To assess the differences between genders and among generations were used the parametric T-Test and one-way ANOVA. Findings: The results demonstrate divergencies between generations when using mobile devices. In addition, they indicate that males have more intention to manage shopping tasks efficiently and consequently are less affected by in-store marketing stimuli and less predisposed to impulse purchases. Research limitations/implications: Although real customers participated, a convenience sample was used. The results should be compared with research on other retailer types. The customer shopping motivations and the types of mobile device usage should be further investigated since they can change the experience and the retailer’s outcomes. Practical implications: Contributing to related specific research areas such as shopping behaviour and technology in retail settings by showing the usage preferences, the study also provides information for retailers, especially those needing to approach the Gen Z customers, improving the development of strategies. Originality/value: This research explores further the complementary role of the mobile device in an in-store purchase. By conducting the study in a new setting, it brings new insight into a less explored, yet important sector.info:eu-repo/semantics/publishedVersio

    The Balassa-Samuelson Effect in 'East & West'. Differences and Similarities

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    Based on two detailed Balassa-Samuelson (BS) studies, Wagner and Hlouskova (2004) for eight Central Eastern European countries (CEECs) and Wagner and Doytchinov (2004) for ten Western European countries (WECs), this study assesses the differences and similarities of the BS effect between these two country groups. The econometric results show that the BS effect may have been overestimated in previous studies due to application of inappropriate first generation panel cointegration methods. When appropriately quantified, the BS effect itself explains RER movements respectively inflation differentials only to a small extent. However, extended BS relationships that include additional variables allow for an adequate modelling of inflation. Based on the comparative analysis we draw some conclusions for monetary policy in the future enlarged Euro Area.Balassa-Samuelson effect, Central and Eastern Europe, Western Europe, Non-stationary panels, Inflation simulations

    Genome transcription/translation of segmented, negative-strand RNA viruses

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    The requirements for alignment of capped RNA leader sequences along the viral genome during influenza transcription initiation (“cap-snatching”) have long been an enigma. Previous work on Tomato spotted wilt virus (TSWV) transcription initiation has revealed that this virus displays a preference for leaders with increasing base complementarity to the 3'-ultimate residues of the viral RNA template. Assuming that cap-snatching is a highly conserved mechanism, it is tempting to speculate that the findings for TSWV apply to all segmented negative RNA viruses. The research in this thesis aimed to analyze whether similar cap donor requirements applied for Influenza A virus transcription initiation as compared to what has been found for TSWV. Indeed, in vitro studies demonstrated that influenza transcriptase prefers multiple base-pairing capped leaders. Additionally, the occurrence of “prime-and-realign” during influenza transcription initiation was observed, as well as internal priming at the 3'-penultimate viral residue. The in vitro findings were confirmed by similar studies performed during influenza infection of cell cultures. Whereas transcription initiation of TSWV has been relatively well studied, transcription termination has not. It is postulated that transcription termination/translation is triggered by the formation of a hairpin structure. In cell experiments support a role of the TSWV hairpin structure in translation.</p

    The valuation of housing in low-amenity and low purchasing power city districts: social and economic value entangled by default

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    Urban development projects are based on both calculative practices, in order to render investments in new housing profitable, and on a broader assessment of the value of amenities, qualities associated with housing units such as access to parks and shopping facilities, while not directly being included in presumptive buyers’ prices or rents but still affecting the prices or rents paid because amenities affect market demand. This condition is particularly cumbersome in low-income city districts, and/or in city districts with “negative” amenities, such as visible street crime and a substandard quality of schooling. A study of an urban development project in a “particularly socially vulnerable” city district in Sweden shows how municipally-owned real estate companies and private construction companies need to collaborate with authorities (e.g. the police) and municipal boards (e.g. the education board) to advocate investment in amenities. In order to increase housing stock evaluations, local housing market attractiveness, and the housing welfare of residents in blighted city districts, urban development projects must include, in substantive ways, a variety of perspectives, competencies, and formal decision-making authorities

    Non-structural proteins of arthropod-borne bunyaviruses: roles and functions

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    Viruses within the Bunyaviridae family are tri-segmented, negative-stranded RNA viruses. The family includes several emerging and re-emerging viruses of humans, animals and plants, such as Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus, La Crosse virus, Schmallenberg virus and tomato spotted wilt virus. Many bunyaviruses are arthropod-borne, so-called arboviruses. Depending on the genus, bunyaviruses encode, in addition to the RNA-dependent RNA polymerase and the different structural proteins, one or several non-structural proteins. These non-structural proteins are not always essential for virus growth and replication but can play an important role in viral pathogenesis through their interaction with the host innate immune system. In this review, we will summarize current knowledge and understanding of insect-borne bunyavirus non-structural protein function(s) in vertebrate, plant and arthropod

    Stability of Transgenic Resistance Against Plant Viruses

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