194 research outputs found

    Over-expression of AtPAP2 in Camelina sativa leads to faster plant growth and higher seed yield

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    <p>Abstract</p> <p>Background</p> <p>Lipids extracted from seeds of <it>Camelina sativa </it>have been successfully used as a reliable source of aviation biofuels. This biofuel is environmentally friendly because the drought resistance, frost tolerance and low fertilizer requirement of <it>Camelina sativa </it>allow it to grow on marginal lands. Improving the species growth and seed yield by genetic engineering is therefore a target for the biofuels industry. In <it>Arabidopsis</it>, overexpression of purple acid phosphatase 2 encoded by <it>Arabidopsis </it>(<it>AtPAP2</it>) promotes plant growth by modulating carbon metabolism. Overexpression lines bolt earlier and produce 50% more seeds per plant than wild type. In this study, we explored the effects of overexpressing AtPAP2 in <it>Camelina sativa</it>.</p> <p>Results</p> <p>Under controlled environmental conditions, overexpression of AtPAP2 in <it>Camelina sativa </it>resulted in longer hypocotyls, earlier flowering, faster growth rate, higher photosynthetic rate and stomatal conductance, increased seed yield and seed size in comparison with the wild-type line and null-lines. Similar to transgenic <it>Arabidopsis</it>, activity of sucrose phosphate synthase in leaves of transgenic <it>Camelina </it>was also significantly up-regulated. Sucrose produced in photosynthetic tissues supplies the building blocks for cellulose, starch and lipids for growth and fuel for anabolic metabolism. Changes in carbon flow and sink/source activities in transgenic lines may affect floral, architectural, and reproductive traits of plants.</p> <p>Conclusions</p> <p>Lipids extracted from the seeds of <it>Camelina sativa </it>have been used as a major constituent of aviation biofuels. The improved growth rate and seed yield of transgenic <it>Camelina </it>under controlled environmental conditions have the potential to boost oil yield on an area basis in field conditions and thus make <it>Camelina</it>-based biofuels more environmentally friendly and economically attractive.</p

    Is acupuncture effective in controlling gagging when taking an alginate impressions?

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    Our community health project aimed to (1) identify the prevalence of gagging among patients attending the Prince Philip Dental Hospital; and to identify socio-demographic variations in reported gagging experiences; and (2) perform a pilot study to evaluate the effectiveness of acupuncture in the control of gagging in the dental setting. Methods: A survey on reported gagging experiences was conducted among patients attending our hospital involving a convenience sample of 225 patients. Participants who reported to previously gag in the dental setting were invited to participate in a pilot study to evaluate the effectiveness of acupuncture in controlling gagging when taking an upper alginate impression. Participants were randomized to receive acupuncture stimulation at a site reported to be effective in the control of gagging on the lower lip (point CV 24) or at a sham site on the upper lip (point GV 26) on their first visit and at their second visit to receive the alternative acupuncture stimulation. Results: The response rate to the survey was 81.3% (183/225). Approximately a third (58/183) reported to have experienced gagging in the dental setting and most frequently encountered this when having a dental impression (among approximately a quarter of participants - 44/183). Half (95/183) reported gagging while performing oral self-care. Four in ten participants (73/183) reported some stress visiting the dentist related to gagging. Sociodemographic variations in reported gagging experiences were evident with respect to age, gender and education level. The response rate to the pilot study was 92.3% (36/39). There was no significant difference in the prevalence of gagging when acupuncture was applied to the test site compared to when acupuncture was applied to the sham site on dental examination (p>0.05) or when taking an upper alginate impression (p>0.05). Conclusions: Gagging in a relative common experience reported by patients attending our hospital – in daily life, in the dental setting and in performing oral self-care. Socio-demographic variations in the prevalence of gagging were apparent. The pilot study does not support the use of acupuncture in controlling gagging in the dental setting.published_or_final_versio

    Campylobacter jejuni transcriptome changes during loss of culturability in water

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    Background: Water serves as a potential reservoir for Campylobacter, the leading cause of bacterial gastroenteritis in humans. However, little is understood about the mechanisms underlying variations in survival characteristics between different strains of C. jejuni in natural environments, including water. Results: We identified three Campylobacter jejuni strains that exhibited variability in their ability to retain culturability after suspension in tap water at two different temperatures (4°C and 25°C). Of the three strains C. jejuni M1 exhibited the most rapid loss of culturability whilst retaining viability. Using RNAseq transcriptomics, we characterised C. jejuni M1 gene expression in response to suspension in water by analyzing bacterial suspensions recovered immediately after introduction into water (Time 0), and from two sampling time/temperature combinations where considerable loss of culturability was evident, namely (i) after 24 h at 25°C, and (ii) after 72 h at 4°C. Transcript data were compared with a culture-grown control. Some gene expression characteristics were shared amongst the three populations recovered from water, with more genes being up-regulated than down. Many of the up-regulated genes were identified in the Time 0 sample, whereas the majority of down-regulated genes occurred in the 25°C (24 h) sample. Conclusions: Variations in expression were found amongst genes associated with oxygen tolerance, starvation and osmotic stress. However, we also found upregulation of flagellar assembly genes, accompanied by down-regulation of genes involved in chemotaxis. Our data also suggested a switch from secretion via the sec system to via the tat system, and that the quorum sensing gene luxS may be implicated in the survival of strain M1 in water. Variations in gene expression also occurred in accessory genome regions. Our data suggest that despite the loss of culturability, C. jejuni M1 remains viable and adapts via specific changes in gene expression

    Characterization of basal and lipopolysaccharide-induced microRNA expression in equine peripheral blood mononuclear cells using Next-Generation Sequencing

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    The innate immune response to lipopolysaccharide contributes substantially to the morbidity and mortality of gram-negative sepsis. Horses and humans share an exquisite sensitivity to lipopolysaccharide and thus the horse may provide valuable comparative insights into this aspect of the inflammatory response. MicroRNAs, small non-coding RNA molecules acting as post-transcriptional regulators of gene expression, have key roles in toll-like receptor signaling regulation but have not been studied in this context in horses. The central hypothesis of this study was that lipopolysaccharide induces differential microRNA expression in equine peripheral blood mononuclear cells in a manner comparable to humans. Illumina Next Generation Sequencing was used to characterize the basal microRNA transcriptome in isolated peripheral blood mononuclear cells from healthy adult horses, and to evaluate LPS-induced changes in microRNA expression in cells cultured for up to four hours. Selected expression changes were validated using quantitative reverse-transcriptase PCR. Only miR-155 was significantly upregulated by LPS, changing in parallel with supernatant tumor necrosis factor-α concentration. Eight additional microRNAs, including miR-146a and miR-146b, showed significant expression change with time in culture without a clear LPS effect. Target predictions indicated a number of potential immunity-associated targets for miR-155 in the horse, including SOCS1, TAB2 and elements of the PI3K signaling pathway, suggesting that it is likely to influence the acute inflammatory response to LPS. Gene alignment showed extensive conservation of the miR-155 precursor gene and associated promoter regions between horses and humans. The basal and LPS-stimulated microRNA expression pattern characterized here were similar to those described in human leukocytes. As well as providing a resource for further research into the roles of microRNAs in immune responses in horses, this will facilitate inter-species comparative study of the role of microRNAs in the inflammatory cascade during endotoxemia and sepsis

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Pan-cancer analysis of whole genomes

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    Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

    stairs and fire

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    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    Do Dragons Have Better Fate?

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    Traditionally, belief in the Chinese zodiac promotes the superstition that the timing of one's birth determines one's fate. Adherence to this belief has resulted in increased birth rates during Dragon years and, hence, problems in the logistics of providing certain public goods and services (such as schools and medical services) by governments. Despite the possible economic impacts of this superstition on society, no previous study has attempted to test its validity. Using the 1991 and 1996 Hong Kong census data sets, as well as the standard return-to-education methodology, we do not find any evidence for this pervasive superstition. (JEL J13, J18, Z12) Copyright 2005, Oxford University Press.

    The chemistry of osmium-palladium mixed-metal nanoclusters and nanoparticles

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