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Bacteria interact with a multitude of other organisms, many of which produce antimicrobials. Selection for resistance to these antimicrobials has the potential to result in resistance to clinical antibiotics when active compounds target the same bacterial pathways. The possibility of such cross-resistance between natural antimicrobials and antibiotics has to our knowledge received very little attention. The antimicrobial activity of extracts from seaweeds, known to be prolific producers of antimicrobials, is here tested against Staphylococcus aureus isolates with varied clinical antibiotic resistance profiles. An overall effect consistent with cross-resistance is demonstrated, with multidrug-resistant S. aureus strains being on average more resistant to seaweed extracts. This pattern could potentially indicate that evolution of resistance to antimicrobials in the natural environment could lead to resistance against clinical antibiotics. However, patterns of antimicrobial activity of individual seaweed extracts vary considerably and include collateral sensitivity, where increased resistance to a particular antibiotic is associated with decreased resistance to a particular seaweed extract. Our correlation-based methods allow the identification of antimicrobial extracts bearing most promise for downstream active compound identification and pharmacological testing.

Background Symptomatic aortic stenosis has a poor prognosis. Many patients are considered inoperable or at high surgical risk for surgical aortic valve replacement (SAVR), reflecting their age, comorbidities and frailty. The clinical effectiveness and safety of TAVI have not been reviewed systematically for these high levels of surgical risk. This systematic review compares mortality and other important clinical outcomes up to 5 years post treatment following TAVI or other treatment in these risk groups. Methods A systematic review protocol was registered on the PROSPERO database (CRD42016048396). The Cochrane Library, Centre for Reviews and Dissemination Databases, MEDLINE, EMBASE, and ZETOC were searched from January 2002 to August 2016. Clinical trials or matched studies comparing TAVI with other treatments for AS in patients surgically inoperable or operable at a high risk were included. Data extraction and quality assessment were conducted by two reviewers. Data were pooled using random-effects meta-analysis. The main outcomes were all-cause mortality, efficacy and major complications. Results Three good quality randomised controlled trials (RCTs) were included. Patients’ mean age ranged from 83- 85 years, around half were female and New York Heart Association (NYHA) functional class III or IV ranged from 83.8% to 94.2% with frequent comorbidities. In 358 surgically inoperable patients from one RCT, TAVI was superior to medical therapy for all-cause mortality at 1 year (hazard ratio (HR) 0.58, 95% confidence interval (CI) 0.36−0.92), 2 years (HR 0.50, 95% CI 0.39−0.65), 3 years (HR 0.53, 95% CI 0.41to 0.68) and 5 years (HR 0.50, 95% CI 0.39−0.65), and NYHA class III or IV at 2 years (TAVI 16.8% (16/95), medical therapy 57.5% (23/40), p In a meta-analysis including 1,494 high risk surgically operable patients from two non-inferiority RCTs TAVI showed no significant differences from SAVR in all-cause mortality at two years (HR 1.03, 95% CI 0.82−1.29) and up to 5 years (HR 0.83, 95% CI 0.83−1.12). There were no statistically significant differences in major vascular complications and myocardial infarction at any time point, discrepant results for major bleeding on variable definitions and no differences in stroke rate at any time point. Using the GRADE tool, this evidence was considered of low quality. Conclusions Symptomatic aortic stenosis can be lethal without intervention but surgical resection is contraindicated for some patients and high risk for others. We found that all-cause mortality up to 5 years of follow-up did not differ significantly between TAVI and SAVR in patients surgically operable at a high risk, but favoured TAVI over medical therapy in patients surgically inoperable. TAVI is a viable life-extending treatment option in these surgical high risk groups.

[This corrects the article DOI: 10.1186/s41512-016-0001-y.].

Introduction Barrett's oesophagus (BO), a metaplastic condition affecting the lower oesophagus due to long-standing gastro-oesophageal reflux and chronic inflammation, is a precursor lesion for oesophageal adenocarcinoma (OADC). There is no clinical test to predict which patients with BO will progress to OADC. The British Society of Gastroenterology recommends endoscopic surveillance of patients with BO. Epigenetic changes have been well characterised in the neoplastic progression of ulcerative colitis to colonic carcinoma, another gastrointestinal cancer associated with chronic inflammation. This systematic review protocol aims to identify and evaluate studies which examine epigenetic biomarkers in BO and their association with progression to OADC. Methods and analysis All prospective and retrospective primary studies, and existing systematic reviews investigating epigenetic markers including DNA methylation, histone modification, chromatin remodelling, micro and non-coding RNAs of all types will be eligible for inclusion. Eligible patients are those over the age of 18 with BO, BO with dysplasia, OADC or unspecified oesophageal cancer. A comprehensive search of bibliographic databases using combinations of text and index words relating to the population, prognostic markers and outcome will be undertaken with no language restrictions. Results will be screened by 2 independent reviewers and data extracted using a standardised proforma. The quality and risk of bias of individual studies will be assessed using the Quality in Prognostic Studies (QUIPS) tool. A narrative synthesis of all evidence will be performed with key findings tabulated. Meta-analysis will be considered where studies and reported outcomes are considered sufficiently homogeneous, both clinically and methodologically. Findings will be interpreted in the context of the quality of included studies. The systematic review will be reported according to PRISMA guidelines. Ethics and dissemination This is a systematic review of completed studies and no ethical approval is required. Findings from the full systematic review will be submitted for publication and presentation at national and international conferences which will inform future research on risk stratification in patients with BO. Review registration number CRD42016038654.

This study built on a previous piece of my research, which found that student perceptions of the efficacy of feedback do not always match what both teachers and the literature might expect. A new model of written feedback was implemented in the classroom that praises the process of learning as opposed to the outcome. 2 collaborating teachers implemented a criteria-driven effort grade feedback intervention in conjunction with standard practice of constructive written comments. 50 year-10 students from 2 mixed attainment science sets were studied in terms of their motivation for learning, engagement with the feedback process and resulting attainment before and after intervention. The effectiveness of the intervention was assessed using action research methodology in two cycles gathering evidence from the collaborating teacher and students using interviews and questionnaires. Analysis of the data showed that reactions to the intervention from both teachers and students were positive. Students initially struggled to identify and reflect on their own effort, often over-estimating it when compared to teacher assessment. Throughout the intervention, however, refinements to the effort-criteria, based on evidence gathered in the action research process, enabled increased student awareness of effort and ability to apply consistent grading. Motivation to learn improved and homework completion rates increased from 35% to 90%. Students showed better engagement with the feedback process and increased reflection and utilisation of written comments. A marginal increase in attainment was noted, though the limitations in using this as a measure with a small sample and short duration are discussed. Contemporary educational research and implications for future practice are discussed; wider-use of effort-grading in feedback is indicated to verify findings in different subject areas. Teacher collaboration is crucial in achieving this and the practicalities of larger-scale roll-out are considered.

We demonstrate electrically driven coherent quantum interference in the optical transition of single, basally oriented divacancies in commercially available 4H silicon carbide. By applying microwave frequency electric fields, we coherently drive the divacancy’s excited-state orbitals and induce Landau-Zener-Stückelberg interference fringes in the resonant optical absorption spectrum. In addition, we find remarkably coherent optical and spin subsystems enabled by the basal divacancy’s symmetry. These properties establish divacancies as strong candidates for quantum communication and hybrid system applications, where simultaneous control over optical and spin degrees of freedom is paramount.