1,236 research outputs found

    The evolution of RNAs with multiple functions

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    Increasing numbers of transcripts have been reported to transmit both protein-coding and regulatory information. Apart from challenging our conception of the gene, this observation raises the question as to what extent this phenomenon occurs across the genome and how and why such dual encoding of function has evolved in the eukaryotic genome. To address this question, we consider the evolutionary path of genes in the earliest forms of life on Earth, where it is generally regarded that proteins evolved from a cellular machinery based entirely within RNA. This led to the domination of protein-coding genes in the genomes of microorganisms, although it is likely that RNA never lost its other capacities and functionalities, as evidenced by cis-acting riboswitches and UTRs. On the basis that the subsequent evolution of a more sophisticated regulatory architecture to provide higher levels of epigenetic control and accurate spatiotemporal expression in developmentally complex organisms is a complicated task, we hypothesize: (i) that mRNAs have been and remain subject to secondary selection to provide trans-acting regulatory capability in parallel with protein-coding functions; (ii) that some and perhaps many protein-coding loci, possibly as a consequence of gene duplication, have lost protein-coding functions en route to acquiring more sophisticated trans-regulatory functions; (iii) that many transcripts have become subject to secondary processing to release different products; and (iv) that novel proteins have emerged within loci that previously evolved functionality as regulatory RNAs. In support of the idea that there is a dynamic flux between different types of informational RNAs in both evolutionary and real time, we review recent observations that have arisen from transcriptomic surveys of complex eukaryotes and reconsider how these observations impact on the notion that apparently discrete loci may express transcripts with more than one function. In conclusion, we posit that many eukaryotic loci have evolved the capacity to transact a multitude of overlapping and potentially independent functions as both regulatory and protein-coding RNAs

    Fluoridated elastomers: Effect on the microbiology of plaque

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    The objective of this study was to investigate the effect of fluoridated elastomeric ligatures on the microbiology of local dental plaque in vivo. This randomized, prospective, longitudinal, clinical trial had a split-mouth crossover design. The subjects were 30 patients at the beginning of their treatment with fixed orthodontic appliances in the orthodontic departments of the Liverpool and the Sheffield dental hospitals in the United Kingdom. The study consisted of 2 experimental periods of 6 weeks with a washout period between. Fluoridated elastomers were randomly allocated at the first visit to be placed around brackets on tooth numbers 12, 11, 33 or 22, 21, 43. Nonfluoridated elastomers were placed on the contralateral teeth. Standard nonantibacterial fluoridated toothpaste and mouthwash were supplied. After 6 weeks (visit 2), the elastomers were removed, placed in transport media, and plated on agar within 2 hours. Nonfluoridated elastomers were placed on all brackets for 1 visit to allow for a washout period. At visit 3, fluoridated elastomers were placed on the teeth contralateral to those that received them at visit 1. At visit 4, the procedures at visit 2 were repeated. Samples were collected on visits 2 and 4. A logistic regression was performed, with the presence or absence of streptococcal or anaerobic growth as the dependent variable. A mixed-effects analysis of variance was carried out with the percentage of streptococcal or anaerobic bacterial count as the dependent variable. The only significant independent variables were the subject variable (P = < .001) for the percentage of streptococcal and anaerobic bacterial count and the visit variable for the percentage of streptococcal count (P = < .001). The use of fluoridated or nonfluoridated elastomers was not significant for percentage of either streptococcal (P = .288) or anaerobic count (P = .230). Fluoridated elastomers are not effective at reducing local streptococcal or anaerobic bacterial growth after a clinically relevant time in the mouth

    DotAligner:Identification and clustering of RNA structure motifs

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    Abstract The diversity of processed transcripts in eukaryotic genomes poses a challenge for the classification of their biological functions. Sparse sequence conservation in non-coding sequences and the unreliable nature of RNA structure predictions further exacerbate this conundrum. Here, we describe a computational method, DotAligner, for the unsupervised discovery and classification of homologous RNA structure motifs from a set of sequences of interest. Our approach outperforms comparable algorithms at clustering known RNA structure families, both in speed and accuracy. It identifies clusters of known and novel structure motifs from ENCODE immunoprecipitation data for 44 RNA-binding proteins

    How prepared are UK medical graduates for practice? A rapid review of the literature 2009-2014.

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    OBJECTIVE: To understand how prepared UK medical graduates are for practice and the effectiveness of workplace transition interventions. DESIGN: A rapid review of the literature (registration #CRD42013005305). DATA SOURCES: Nine major databases (and key websites) were searched in two timeframes (July-September 2013; updated May-June 2014): CINAHL, Embase, Educational Resources Information Centre, Health Management Information Consortium, MEDLINE, MEDLINE in Process, PsycINFO, Scopus and Web of Knowledge. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Primary research or studies reporting UK medical graduates' preparedness between 2009 and 2014: manuscripts in English; all study types; participants who are final-year medical students, medical graduates, clinical educators, patients or NHS employers and all outcome measures. DATA EXTRACTION: At time 1, three researchers screened manuscripts (for duplicates, exclusion/inclusion criteria and quality). Remaining 81 manuscripts were coded. At time 2, one researcher repeated the process for 2013-2014 (adding six manuscripts). Data were analysed using a narrative synthesis and mapped against Tomorrow's Doctors (2009) graduate outcomes. RESULTS: Most studies comprised junior doctors' self-reports (65/87, 75%), few defined preparedness and a programmatic approach was lacking. Six themes were highlighted: individual skills/knowledge, interactional competence, systemic/technological competence, personal preparedness, demographic factors and transitional interventions. Graduates appear prepared for history taking, physical examinations and some clinical skills, but unprepared for other aspects, including prescribing, clinical reasoning/diagnoses, emergency management, multidisciplinary team-working, handover, error/safety incidents, understanding ethical/legal issues and ward environment familiarity. Shadowing and induction smooth transition into practice, but there is a paucity of evidence around assistantship efficacy. CONCLUSIONS: Educational interventions are needed to address areas of unpreparedness (eg, multidisciplinary team-working, prescribing and clinical reasoning). Future research in areas we are unsure about should adopt a programmatic and rigorous approach, with clear definitions of preparedness, multiple stakeholder perspectives along with multisite and longitudinal research designs to achieve a joined-up, systematic, approach to understanding future educational requirements for junior doctors.This research was commissioned and funded by the General Medical Council who gave feedback on clarity and approved the manuscript for publicatio

    Medical student intentions to move abroad: A UK-based realist evaluation

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    This is the final version. Available from on open access from Ubiquity Press via the DOI in this record. Data accessibility statement: The data that support the findings of this study are available from the corresponding author upon request.INTRODUCTION: Medical students moving abroad after qualification may contribute to domestic healthcare workforce shortages. Greater insights into how medical students make decisions about moving abroad may improve post-qualification retention. The aim was to develop a programme theory explaining medical students' intentions to move abroad or not. METHODS: In Phase 1 the initial programme theory was generated from a literature review. In Phase 2, the theory was developed through 30 realist interviews with medical students from a medical school in the United Kingdom. In Phase 3 the final programme theory was used to produce recommendations for stakeholders. RESULTS: The findings highlight the complex decision-making that medical students undertake when deciding whether to move abroad. We identified five contexts and six mechanisms leading to two outcomes (intention to move abroad and no intention to move abroad). CONCLUSIONS: This realist evaluation has demonstrated how contexts and mechanisms may interact to enable specific outcomes. These insights have allowed evidence-based recommendations to be made with a view to retaining graduates, including protected time within medical curricula to experience other healthcare systems, improved availability of domestic postgraduate posts providing domestic career certainty and stronger domestic-based social support networks for graduates.Association for the Study of Medical Education (ASME)General Medical Council (GMC

    "I'd been like freaking out the whole night": exploring emotion regulation based on junior doctors' narratives

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    The importance of emotions within medical practice is well documented. Research suggests that how clinicians deal with negative emotions can affect clinical decision-making, health service delivery, clinician well-being, attentiveness to patient care and patient satisfaction. Previous research has identified the transition from student to junior doctor (intern) as a particularly challenging time. While many studies have highlighted the presence of emotions during this transition, how junior doctors manage emotions has rarely been considered. We conducted a secondary analysis of narrative data in which 34 junior doctors, within a few months of transitioning into practice, talked about situations for which they felt prepared or unprepared for practice (preparedness narratives) through audio diaries and interviews. We examined these data deductively (using Gross’ theory of emotion regulation: ER) and inductively to answer the following research questions: (RQ1) what ER strategies do junior doctors describe in their preparedness narratives? and (RQ2) at what point in the clinical situation are these strategies narrated? We identified 406 personal incident narratives: 243 (60%) contained negative emotion, with 86 (21%) also containing ER. Overall, we identified 137 ER strategies, occurring prior to (n = 29, 21%), during (n = 74, 54%) and after (n = 34, 25%) the situation. Although Gross’ theory captured many of the ER strategies used by junior doctors, we identify further ways in which this model can be adapted to fully capture the range of ER strategies participants employed. Further, from our analysis, we believe that raising medical students

    Long noncoding RNAs in neuronal-glial fate specification and oligodendrocyte lineage maturation

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    Background: Long non-protein-coding RNAs (ncRNAs) are emerging as important regulators of cellular differentiation and are widely expressed in the brain.Results: Here we show that many long ncRNAs exhibit dynamic expression patterns during neuronal and oligodendrocyte (OL) lineage specification, neuronal-glial fate transitions, and progressive stages of OL lineage elaboration including myelination. Consideration of the genomic context of these dynamically regulated ncRNAs showed they were part of complex transcriptional loci that encompass key neural developmental protein-coding genes, with which they exhibit concordant expression profiles as indicated by both microarray and in situ hybridization analyses. These included ncRNAs associated with differentiation-specific nuclear subdomains such as Gomafu and Neat1, and ncRNAs associated with developmental enhancers and genes encoding important transcription factors and homeotic proteins. We also observed changes in ncRNA expression profiles in response to treatment with trichostatin A, a histone deacetylase inhibitor that prevents the progression of OL progenitors into post-mitotic OLs by altering lineage-specific gene expression programs.Conclusion: This is the first report of long ncRNA expression in neuronal and glial cell differentiation and of the modulation of ncRNA expression by modification of chromatin architecture. These observations explicitly link ncRNA dynamics to neural stem cell fate decisions, specification and epigenetic reprogramming and may have important implications for understanding and treating neuropsychiatric diseases

    Complex architecture and regulated expression of the Sox2ot locus during vertebrate development

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    The Sox2 gene is a key regulator of pluripotency embedded within an intron of a long noncoding RNA (ncRNA), termed Sox2 overlapping transcript (Sox2ot), which is transcribed in the same orientation. However, this ncRNA remains uncharacterized. Here we show that Sox2ot has multiple transcription start sites associated with genomic features that indicate regulated expression, including highly conserved elements (HCEs) and chromatin marks characteristic of gene promoters. To identify biological processes in which Sox2ot may be involved, we analyzed its expression in several developmental systems, compared to expression of Sox2. We show that Sox2ot is a stable transcript expressed in mouse embryonic stem cells, which, like Sox2, is down-regulated upon induction of embryoid body (EB) differentiation. However, in contrast to Sox2, Sox2ot is up-regulated during EB mesoderm-lineage differentiation. In adult mouse, Sox2ot isoforms were detected in tissues where Sox2 is expressed, as well as in different tissues, supporting independent regulation of expression of the ncRNA. Sox2dot, an isoform of Sox2ot transcribed from a distal HCE located >500 kb upstream of Sox2, was detected exclusively in the mouse brain, with enrichment in regions of adult neurogenesis. In addition, Sox2ot isoforms are transcribed from HCEs upstream of Sox2 in other vertebrates, including in several regions of the human brain. We also show that Sox2ot is dynamically regulated during chicken and zebrafish embryogenesis, consistently associated with central nervous system structures. These observations provide insight into the structure and regulation of the Sox2ot gene, and suggest conserved roles for Sox2ot orthologs during vertebrate development

    A comparison of course-related stressors in undergraduate problem-based learning (PBL) versus non-PBL medical programmes

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    Background: Medical students report high levels of stress related to their medical training as well as to other personal and financial factors. The aim of this study is to investigate whether there are differences in course-related stressors reported by medical students on undergraduate problem-based learning (PBL) and non-PBL programmes in the UK. Method: A cross-sectional study of second-year medical students in two UK medical schools (one PBL and one non-PBL programme) was conducted. A 16-question self-report questionnaire, derived from the Perceived Medical Student Stress Scale and the Higher Education Stress Inventory, was used to measure course-related stressors. Following univariate analysis of each stressor between groups, multivariate logistic regression was used to determine which stressors were the best predictors of each course type, while controlling for socio-demographic differences between the groups. Results: A total of 280 students responded. Compared to the non-PBL students (N = 197), the PBL students (N = 83) were significantly more likely to agree that: they did not know what the faculty expected of them (Odds Ratio (OR) = 0.38, p = 0.03); there were too many small group sessions facilitated only by students resulting in an unclear curriculum (OR = 0.04, p < 0.0001); and that there was a lack of opportunity to explore academic subjects of interest (OR = 0.40, p = 0.02). They were significantly more likely to disagree that: there was a lack of encouragement from teachers (OR = 3.11, p = 0.02); and that the medical course fostered a sense of anonymity and feelings of isolation amongst students (OR = 3.42, p = 0.008). Conclusion: There are significant differences in the perceived course-related stressors affecting medical students on PBL and non-PBL programmes. Course designers and student support services should therefore tailor their work to minimise, or help students cope with, the specific stressors on each course type to ensure optimum learning and wellbeing among our future doctors
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