119 research outputs found

    IDENTIFICATION OF VIRAL AND HOST FACTORS INVOLVED IN TOMBUSVIRUS REPLICATION AND RECOMBINATION

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    Rapid evolution of RNA viruses with mRNA-sense genomes is a major concern to health and economic welfare due to the devastating diseases these viruses inflict on humans, animals and plants. Rapid viral RNA evolution is frequently due to RNA recombination, which can be facilitated by recombination signals present in viral RNAs. Among such signals are short sequences with high AU contents that constitute recombination hot spots in Brome mosaic virus (BMV) and retroviruses. We have demonstrated that a defective interfering (DI) RNA, a model template associated with Tomato bushy stunt virus (TBSV), a tombusvirus, undergoes frequent recombination in plants and protoplast cells when it carries the AU-rich hot spot sequence from BMV. Similar to the situation with BMV, most of the recombination junction sites in the DI RNA recombinants were found within the AU-rich region. Our results support the idea that common AU-rich recombination signals might promote interviral recombination between unrelated viruses. To test if host genes can affect the evolution of RNA viruses, we used a Saccharomyces cerevisiae single-gene deletion library, which includes ~80% of yeast genes, in RNA recombination studies based on a small viral replicon RNA derived from TBSV. The genome-wide screen led to the identification of five host genes, whose absence resulted in rapid generation of novel viral RNA recombinants. Thus, these genes normally suppress viral RNA recombination, but in their absence hosts become viral recombination hotbeds. Four of the five recombination suppressor genes are likely involved in RNA degradation, suggesting that RNA degradation could play a role in viral RNA recombination. Overall, our results demonstrate for the first time that a set of host genes have major effect on RNA virus recombination and evolution. Replication of the non-segmented, plus-stranded RNA genome of Cucumber necrosis tombusvirus (CNV) requires two essential overlapping viral-coded replication proteins, the p33 replication co-factor and the p92 RNA-dependent RNA polymerase. We have demonstrated that p33 is phosphorylated in vivo and in vitro by a membrane-bound plant kinase. Based on in vitro studies with purified recombinant p33, we show evidence for phosphorylation of threonine and serine residues adjacent to the essential RNA-binding site in p33. Our findings suggest that phosphorylation of threonine/serine residues adjacent to the essential RNA-binding site in the auxiliary p33 protein likely plays a role in viral RNA replication and subgenomic RNA synthesis during tombusvirus infections

    Trajectories of educational aspirations through high school and beyond: A gendered phenomenon?

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    Growth curve modeling was utilized to examine change in the educational aspirations of adolescents from early high school through to three years beyond high school, as a function of gender and other adolescent characteristics. Significant gender effects were found for level of education aspired to, rate of growth, and degree of acceleration: boys’ aspirations were lower in early high school, accelerated at a faster pace to peak above girls’ aspirations by the end of high school, and dropped more steeply so that, by the post-high school period, educational aspirations were equivalent across genders. Gender also interacted with Grade 9 achievement in determining educational trajectories. Finally, the perception that one faces barriers in educational attainment was found to significantly influence rate of growth and acceleration, indicating that change in aspirations over time differs between people who see barriers to their education and people who do not, independently of gender. Implications of these results for promoting students’ educational aspirations are discussed.Keywords: Gender, high school, educational aspirationsLa modélisation des courbes de croissance a été utilisée pour examiner les changements dans les ambitions scolaires des adolescents à l'école secondaire et jusqu'à trois ans au-delà de l'école secondaire, en fonction du sexe et d'autres caractéristiques des adolescents. D'importantes différences selon le sexe ont été observées concernant le niveau d'éducation auquel les adolescents aspiraient, le taux de croissance, et le degré d'accélération: la courbe représentant les ambitions des garçons était plus basse au début de l'école secondaire, augmentait ensuite à un rythme plus rapide jusqu'à atteindre un pic au-dessus de la courbe des filles pour la période de la fin de l'école secondaire, et chutait enfin plus fortement de telle sorte que les deux courbes se retrouvaient au même niveau dans la période post-secondaire. Le genre a également interagi avec la réussite en neuvième année en déterminant des trajectoires éducatives. Enfin, la perception d'être confronté à des barrières entravant la réussite scolaire s'est révélée être un facteur qui influence de manière significative le taux de croissance et d'accélération, ce qui indique que le changement dans les ambitions scolaires au fil du temps diffère entre ceux qui perçoivent des obstacles au cours de leur scolarité et ceux qui n'en perçoivent pas, indépendamment de leur sexe. Les implications de ces résultats pour promouvoir les ambitions scolaires des élèves sont discutées.Mots-clés: Genre, école secondaire, aspirations scolaire

    Ionic liquids for promising ion-conducting polymer materials of electrochemical devices

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    The review is devoted to analysis of synthesis methods development of ionic liquids based on quaternary ammonium salts and their application as components of the liquid and polymeric electrolytes for various electrochemical devices. The special attention is given to the properties analysis of ionic liquids depending on the structure of them cationic and anionic parts. The data on composition and properties of polymeric electrolytes that can be used in lithium batteries, capacitors, fuel cells, and dye-sensitized solar cells are shown.Проаналізовано розвиток методів синтезу іонних рідин на основі четвертинних амонієвих солей і їх застосування як компонент рідких і полімерних електролітів для різних електрохімічних пристроїв. Особливу увагу надано аналізу залежності властивостей іонних рідин від структури їх катіонної та аніонної частин. Наведено дані складу і властивостей полімерних електролітів, які можуть використовуватися в літієвих батареях, конденсаторах, сонячних батареях.Обзор посвящен анализу развития методов синтеза ионных жидкостей на основе четвертичных аммониевых солей и их применения в качестве компонент жидких и полимерных электролитов для различных электрохимических устройств. Особое внимание уделяется анализу зависимостисвойств ионных жидкостей от структуры их катионной и анионной частей. Представлены данные по составу и свойствам полимерных электролитов, которые могут использовать в литиевых батареях, конденсаторах, солнечных батареях

    Career success: the role of teenage career aspirations, ambition value and gender in predicting adult social status and earnings

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    Links between family social background, teenage career aspirations, educational performance and adult social status attainment are well documented. Using a contextual developmental framework, this article extends previous research by examining the role of gender and teenage ambition value in shaping social status attainment and earnings in adulthood. Drawing on data from an 18-year British follow up study we tested a path model linking family background factors (such as family social status and parental aspirations) and individual agency factors in adolescence (in particular, career aspirations and ambition value) to social status attainment and earnings in adulthood. The findings suggest that ambition value is linked to adult earnings. That is, young people for whom it is important to get on in their job earn more money in adulthood than their less ambitious peers. The findings also confirm that teenage career aspirations are linked to adult social status attainment, and suggest that family background factors, teenage career aspirations and ambition value interact to influence social status attainment and earnings in adulthood. Gender differences are discusse

    Combination of osteogenesis imperfecta and type 1 diabetes mellitus

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    Osteogenesis imperfecta (OI) is a hereditary connective tissue disorder accompanied by increased bone fragility. Five types of OI are distinguished on the basis of phenotypic manifestations. OI type 1 is characterized by a reduced amount of normal type 1 collagen and is the mildest form. In addition to the fractures, course of disease can be accompanied by short stature, skeletal deformity and joint hypermobility. Although fracture risk decreases with age, such patients needs regular follow-up with an assessment of bone mineral density (BMD) and, if necessary, correction of therapy to improve the quality of life. Type 1 diabetes mellitus (T1DM) is associated with a decreased BMD, which is mostly attributed to insulin deficiency and hyperglycemia, which also increase the risk of fractures. Achieving and stable maintenance of glycemic targets is often challenging, but it is necessary to exclude hyperglycemia as a factor that further worsens the quality of bone. This paper describes a clinical case of an extremely rare combination of type 1 OI and T1DM, two diseases with a pronounced negative effect on bone tissue. The combination of these pathologies requires special management tactics for such patients to reduce the risk of developing new fractures

    Controlling for Prior Attainment Reduces the Positive Influence that Single-Gender Classroom Initiatives Exert on High School Students’ Scholastic Achievements.

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    Research points to the positive impact that gender-segregated schooling and classroom initiatives exert on academic attainment. An evaluation of these studies which reveal positive effects highlights, however, that students are typically selectively assigned to single- or mixed-gender instructional settings, presenting a methodological confound. The current study controls for students’ prior attainment to appraise the efficacy of a single-gender classroom initiative implemented in a co-educational high school in the United Kingdom. Secondary data analysis (using archived data) was performed on 266 middle-ability, 11–12 year-old students’ standardized test scores in Languages (English, foreign language), STEM-related (Mathematics, Science, Information and Communication Technology), and Non-STEM subjects (art, music, drama). Ninety-eight students (54, 55% female) were taught in single-gender and 168 (69, 41% female) in mixed-gender classrooms. Students undertook identical tests irrespective of classroom type, which were graded in accordance with U.K national curriculum guidelines. Controlling for students’ prior attainment, findings indicate that students do not appear to benefit from being taught in single-gender relative to mixed-gender classrooms in Language and STEM-related subjects. Young women benefitted from being taught in mixed-gender relative to single-gender classes for Non-STEM subjects. However, when prior ability is not controlled for, the intervention appears to be effective for all school subjects, highlighting the confounding influence of selective admissions. These findings suggest that gender-segregated classroom initiatives may not bolster students’ grades. It is argued that studies that do not control for selection effects may tell us little about the effectiveness of such interventions on scholastic achievement

    Moral Disengagement and Risk Prototypes in the Context of Adolescent Cyberbullying: Findings From Two Countries

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    Cyberbullying is associated with a wide range of mental health difficulties and behavioral problems in adolescents and research is needed to better understand psychological correlates of this behavior. The present study used a novel model that incorporated Social Cognitive Theory and the prototype/willingness model to identify the correlates of behavioral willingness to engage in cyberbullying in two countries. Adolescent students were randomly selected from secondary schools in Italy (n = 1710) and Greece (n = 355), and completed anonymous measures of moral disengagement, descriptive norms, risk prototype evaluations and behavioral willingness to engage in cyberbullying. Hierarchical linear regression analyses showed that willingness to engage in cyberbullying was associated with moral disengagement, prototype evaluations and descriptive social norms in Italy, and with gender, moral disengagement and descriptive social norms in Greece. Regression-based multiple mediation modeling further showed that the association between moral disengagement and cyberbullying willingness was mediated by prototype evaluations in Italy and by descriptive norms in Greece. The implications of our findings are discussed in the context of self-regulating cyberbullying perpetration in adolescents and informing school-based policies and interventions to prevent cyberbullying behavior

    Recombination and positive selection identified in complete genome sequences of Japanese encephalitis virus

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    The mosquito-borne Japanese encephalitis virus (JEV) causes encephalitis in man but not in pigs. Complete genomes of a human, mosquito and pig isolate from outbreaks in 1982 and 1985 in Thailand were sequenced with the aim of identifying determinants of virulence that may explain the differences in outcomes of JEV infection between pigs and man. Phylogenetic analysis revealed that five of these isolates belonged to genotype I, but the 1982 mosquito isolate belonged to genotype III. There was no evidence of recombination among the Thai isolates, but there were phylogenetic signals suggestive of recombination in a 1994 Korean isolate (K94P05). Two sites of the genome under positive selection were identified: codons 996 and 2296 (amino acids 175 of the non-structural protein NS1 and 24 of NS4B, respectively). A structurally significant substitution was seen at NS4B position 24 of the human isolate compared with the mosquito and pig isolates from the 1985 outbreak in Thailand. The potential importance of the two sites in the evolution and ecology of JEV merits further investigation
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