221 research outputs found

    Changes in the capacity of visual working memory in 5- to 10-year-olds

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    Using the Luck and Vogel change detection paradigm, we sought to investigate the capacity of visual working memory in 5-, 7-, and 10-year-olds. We found that performance on the task improved significantly with age and also obtained evidence that the capacity of visual working memory approximately doubles between 5 and 10 years of age, where it reaches adult levels of approximately three to four items

    Sexual reproduction is the null hypothesis for life cycles of rust fungi

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    Sexual reproduction, mutation, and reassortment of nuclei increase genotypic diversity in rust fungi. Sexual reproduction is inherent to rust fungi, coupled with their coevolved plant hosts in native pathosystems. Rust fungi are hypothesised to exchange nuclei by somatic hybridisation with an outcome of increased genotypic diversity, independent of sexual reproduction. We provide criteria to demonstrate whether somatic exchange has occurred, including knowledge of parental haplotypes and rejection of fertilisation in normal rust life cycles

    Dietary, lifestyle and clinicopathological factors associated with BRAF and K-ras mutations arising in distinct subsets of colorectal cancers in the EPIC Norfolk study.

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    BACKGROUND: BRAF and K-ras proto-oncogenes encode components of the ERK signalling pathway and are frequently mutated in colorectal cancer. This study investigates the associations between BRAF and K-ras mutations and clinicopathological, lifestyle and dietary factors in colorectal cancers. METHODS: 186 adenocarcinomas and 16 adenomas from the EPIC Norfolk study were tested for BRAF and K-ras mutations. Diet and lifestyle data were collected prospectively using seven day food diaries. RESULTS: BRAF V600E mutation was found in 15.6% of colorectal cancers but at higher frequencies in cancers with proximal location, poor differentiation and microsatellite instability (MSI) (all p < 0.001). K-ras mutation (mostly in codons 12 and 13) was found in 22.0% of colorectal cancers but at higher frequencies in cancers of more advanced Dukes' stage (p = 0.001), microsatellite stable (MSS) status (p = 0.002) and in individuals with lower blood high-density lipoprotein concentrations (p = 0.04). Analysis of dietary factors demonstrated no link between BRAF mutation and any specific dietary constituent, however, K-ras mutation was found at higher frequencies in individuals with higher white meat consumption (p < 0.001). Further analysis of specific mutation type demonstrated that G to A transitions in K-ras were observed at higher frequencies in individuals consuming lower amounts of fruit (p = 0.02). CONCLUSION: These data support the model of BRAF and K-ras mutations arising in distinct colorectal cancer subsets associated with different clinicopathological and dietary factors, acting as mutually exclusive mechanisms of activation of the same signalling pathway.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Alterations in PTEN and PIK3CA in colorectal cancers in the EPIC Norfolk study: associations with clinicopathological and dietary factors.

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    BACKGROUND: The PTEN tumour suppressor gene and PIK3CA proto-oncogene encode proteins which contribute to regulation and propagation of signal transduction through the PI3K/AKT signalling pathway. This study investigates the prevalence of loss of PTEN expression and mutations in both PTEN and PIK3CA in colorectal cancers (CRC) and their associations with tumour clinicopathological features, lifestyle factors and dietary consumptions. METHODS: 186 adenocarcinomas and 16 adenomas from the EPIC Norfolk study were tested for PTEN and PIK3CA mutations by DNA sequencing and PTEN expression changes by immunohistochemistry. Dietary and lifestyle data were collected prospectively using seven day food diaries and lifestyle questionnaires. RESULTS: Mutations in exons 7 and 8 of PTEN were observed in 2.2% of CRC and PTEN loss of expression was identified in 34.9% CRC. Negative PTEN expression was associated with lower blood low-density lipoprotein concentrations (p = 0.05). PIK3CA mutations were observed in 7% of cancers and were more frequent in CRCs in females (p = 0.04). Analysis of dietary intakes demonstrated no link between PTEN expression status and any specific dietary factor. PTEN expression negative, proximal CRC were of more advanced Dukes' stage (p = 0.02) and poor differentiation (p < 0.01). Testing of the prevalence of PIK3CA mutations and loss of PTEN expression demonstrated that these two events were independent (p = 0.55). CONCLUSION: These data demonstrated the frequent occurrence (34.9%) of PTEN loss of expression in colorectal cancers, for which gene mutations do not appear to be the main cause. Furthermore, dietary factors are not associated with loss of PTEN expression. PTEN expression negative CRC were not homogenous, as proximal cancers were associated with a more advanced Dukes' stage and poor differentiation, whereas distal cancers were associated with earlier Dukes' stage.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Realising the Ambition - Being Me : National Practice Guidance for Early Years in Scotland

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    Since 2013 there has been a determined focus by the Scottish Government to work towards realising the ambition for Scotland to be the best place for children to grow up in and learn. Changes to the Children and Young People (Scotland) Act 2014, have resulted in our youngest children, particularly those from birth to starting school, being at the heart of significant new developments. In 2014 Scottish Government started to increase the number of hours of funded provision to 600 hours for 3 and 4 year olds and some two year olds. The national practice guidance, “Building the Ambition” was commissioned at this time to complement the new policy developments and to support practitioners. The further expansion of funded Early Learning and Childcare (ELC) to 1140 hours per year for all 3 and 4 year olds, and for around a quarter of 2 year olds will be available from August 2020. This expansion to 1140 hours seeks not only to extend funded places, but to also improve the quality of our ELC provision across Scotland. We know that the earliest years of life are crucial for every child. Evidence tells us that, if our early learning and childcare offer is to help children fulfil their potential and contribute to closing the poverty related gap in children’s outcomes, it has to be high quality. To support the expansion it was decided to refresh the original Building the Ambition, incorporating and updating relevant aspects of the Pre-Birth to Three guidance and extending across the child’s learning journey into the early years of primary school. This new guidance, Realising the Ambition: Being Me, reflects the original principles and philosophy of Building the Ambition and complements the current policy direction of ELC and early primary education. It aspires to support practitioners in delivering what babies and young children need most and how we can most effectively deliver this in Scotland to give children the best start in life. The practice guidance aims to support anyone who works with and for babies and young children across all areas of Scotland. It has been designed to: build confidence and capability of those who work with children and families from pre-birth to starting school and beyond; make links between practice, theory and policy guidance to reinforce aspects of high quality provision and the critical role practitioners play; clarify some aspects of current practice and provide a reference which practitioners can easily use; support improvement and quality by encouraging discussion, self reflection and questioning about relevant practice in each setting, and; provide advice on achieving the highest quality of ELC and early primary provision that will enable young children to experience and to play their own part in Scotland being the best place in the world to grow up

    Evaluating Student Volunteer and Service-Learning Programs: A Casebook for Practitioners

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    Today, evaluation concepts and methods are widely available to those who plan and administer student volunteer programs. Unfortunately, however, evaluation has all too often been carried out-and written about-in ways that have robbed it of its usefulness to people dealing with the realities of day-to-day program operation. Evaluation has thus acquired the reputation among practitioners of being too complex, too costly, too time-consuming, even too threatening to be of much practical value

    Population genomics reveals historical and ongoing recombination in the Fusarium oxysporum species complex

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    The Fusarium oxysporum species complex (FOSC) is a group of closely related plant pathogens long-considered strictly clonal, as sexual stages have never been recorded. Several studies have questioned whether recombination occurs in FOSC, and if it occurs its nature and frequency are unknown. We analysed 410 assembled genomes to answer whether FOSC diversified by occasional sexual reproduction interspersed with numerous cycles of asexual reproduction akin to a model of predominant clonal evolution (PCE). We tested the hypothesis that sexual reproduction occurred in the evolutionary history of FOSC by examining the distribution of idiomorphs at the mating locus, phylogenetic conflict and independent measures of recombination from genome-wide SNPs and genes. A phylogenomic dataset of 40 single copy orthologs was used to define structure a priori within FOSC based on genealogical concordance. Recombination within FOSC was tested using the pairwise homoplasy index and divergence ages were estimated by molecular dating. We called SNPs from assembled genomes using a k-mer approach and tested for significant linkage disequilibrium as an indication of PCE. We clone-corrected and tested whether SNPs were randomly associated as an indication of recombination. Our analyses provide evidence for sexual or parasexual reproduction within, but not between, clades of FOSC that diversified from a most recent common ancestor about 500 000 years ago. There was no evidence of substructure based on geography or host that might indicate how clades diversified. Competing evolutionary hypotheses for FOSC are discussed in the context of our results.The University of Queensland Development Fellowships, the Department of the Environment and Energy under the Australian Biological Resources Study; the Tree Protection Co-operative Programme (TPCP), the National Research Foundation of South Africa and the DST-NRF Centre of Excellence in Tree Health Biotechnology (CTHB).http://www.studiesinmycology.orgam2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog
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