189 research outputs found

    Model-based Investigations of Acidity Sources and Sinks of a Pit Lake in Western Australia

    Get PDF
    Lake Kepwari is a rehabilitated lake in the Collie Basin lignite mining area in Western Australia. The water quality of Lake Kepwari was modeled with the pit lake hydrodynamic and water quality model PITLAKQ. Based on a hydrodynamically validated model, water quality scenarios were used to quantify the sensitivity of different acidity sources including groundwater exchange, surface runoff and erosion, providing new insights into the system. The technique of monthly aggregation of all sources and sinks of acidity, based on detailed model output, provided the basis for useful conclusions. Model results suggest a new focus of field investigations to improve modeling certainty and a follow-up, improved phase of modeling

    Voltage-Controlled High-Bandwidth Terahertz Oscillators Based On Antiferromagnets

    Full text link
    Producing compact voltage-controlled frequency generators and sensors operating in the terahertz (THz) regime represents a major technological challenge. Here, we show that noncollinear antiferromagnets (NCAFM) with kagome structure host gapless self-oscillations whose frequencies are tunable from 0 Hz to the THz regime via electrically induced spin-orbit torques (SOTs). The auto-oscillations' initiation, bandwidth, and amplitude are investigated by deriving an effective theory, which captures the reactive and dissipative SOTs. We find that the dynamics strongly depends on the ground state's chirality, with one chirality having gapped excitations, whereas the opposite chirality provides gapless self-oscillations. Our results reveal that NCAFMs offer unique THz functional components, which could play a significant role in filling the THz technology gap.Comment: 6 pages, 2 figure

    The Powerful Role of Mothers in Adolescent Purpose Development

    Get PDF
    Adolescence is a critical time for the cultivation of life purpose, also known as a meaningful long-term aim focused on contribution to others. Youth with purpose, especially marginalized youth, report a number of positive outcomes. Relationships with caring adults appear to be particularly helpful in guiding young people on their path to purpose, but little work has focused specifically on the role of mothers. This qualitative study, approved by a Institutional Review Board, examines how twenty adolescents from marginalized communities describe their sense of purpose and its relationship to their caregivers. The sample size was determined based on saturation, a process in qualitative research when the researchers begin to observe redundancy in the data. Through content analysis, a major theme emerged: the role of mothers and their impact on purpose development on their children. Results showed that mothers helped their adolescents develop their sense of purpose through serving as a sense of inspiration, providing the adolescents with support, sparking a desire for the adolescents to make their mothers proud, and through the mothers and adolescents in engaging in conversations about one’s future

    ‘Question Moments’: A Rolling Programme of Question Opportunities in Classroom Science

    Get PDF
    This article has been made available through the Brunel Open Access Publishing Fund.This naturalistic study integrates specific 'question moments' into lesson plans to increase pupils' classroom interactions. A range of teaching tools has explored students' ideas through opportunities to ask and write questions. Their oral and written outcomes provide data on individual and group misunderstandings. Changes to the schedule of lessons were introduced to discuss these questions and solve disparities. Flexible lesson planning over fourteen lessons across a four-week period of highschool chemistry accommodated students' contributions and increased student participation, promoted inquiring and individualised teaching, with each teaching strategy feeding forward into the next

    Fannie Mae Business Review Briefing

    Get PDF

    Large bowel obstruction due to sesame seed bezoar: a case report

    Get PDF
    peer-reviewedWe report a case of a 79 year old man with a known benign anastomotic stricture presenting with large bowel obstruction. At laparotomy the obstruction was found to be caused by a large sesame seed bezoar. Seed bezoars are well known to cause impaction in the rectum but have never been previously reported to cause large bowel obstruction. We recommend that patients with known large bowel strictures should be advised not to eat seeds as this could ultimately lead to obstruction, ischaemia or perforationPUBLISHEDpeer-reviewe

    Methanogenic archaea use a bacteria-like methyltransferase system to demethoxylate aromatic compounds

    Get PDF
    Methane-generating archaea drive the final step in anaerobic organic compound mineralization and dictate the carbon flow of Earth’s diverse anoxic ecosystems in the absence of inorganic electron acceptors. Although such Archaea were presumed to be restricted to life on simple compounds like hydrogen (H(2)), acetate or methanol, an archaeon, Methermicoccus shengliensis, was recently found to convert methoxylated aromatic compounds to methane. Methoxylated aromatic compounds are important components of lignin and coal, and are present in most subsurface sediments. Despite the novelty of such a methoxydotrophic archaeon its metabolism has not yet been explored. In this study, transcriptomics and proteomics reveal that under methoxydotrophic growth M. shengliensis expresses an O-demethylation/methyltransferase system related to the one used by acetogenic bacteria. Enzymatic assays provide evidence for a two step-mechanisms in which the methyl-group from the methoxy compound is (1) transferred on cobalamin and (2) further transferred on the C(1)-carrier tetrahydromethanopterin, a mechanism distinct from conventional methanogenic methyl-transfer systems which use coenzyme M as final acceptor. We further hypothesize that this likely leads to an atypical use of the methanogenesis pathway that derives cellular energy from methyl transfer (Mtr) rather than electron transfer (F(420)H(2) re-oxidation) as found for methylotrophic methanogenesis

    Risk of mortality and cardiovascular events following macrolide prescription in chronic rhinosinusitis patients: a cohort study using linked primary care electronic health records

    Get PDF
    Background: Macrolide antibiotics have demonstrated important anti-inflammatory and immunomodulatory properties in chronic rhinosinusitis (CRS) patients. However, reports of increased risks of cardiovascular events have led to safety concerns. We investigated the risk of all-cause and cardiac death, and cardiovascular outcomes, associated with macrolide use. Methodology: Observational cohort (1997-2016) using linked data from the Clinical Practice Research Datalink, Hospital Episodes Statistics, and the Office for National Statistics. Patients aged 16-80 years with CRS prescribed a macrolide antibiotic or penicillin were included, comparing prescriptions for macrolide antibiotics to penicillin. Outcomes were all-cause mortality, cardiac death, myocardial infarction, stroke, diagnosis of peripheral vascular disease, and cardiac arrhythmia. Results: Analysis included 320,798 prescriptions received by 66,331 patients. There were 3,251 deaths, 815 due to cardiovascular causes, 925 incident myocardial infarctions, 859 strokes, 637 diagnoses of peripheral vascular disease, and 1,436 cardiac arrhythmias. A non-statistically significant trend towards increased risk of myocardial infarction during the first 30 days following macrolide prescription was observed (fully adjusted hazard ratio 1.60, 95% confidence interval: 0.95, 2.68, p=0.08). No statistically significant short- or long-term risks were observed for macrolide prescription. No significant risks were identified for clarithromycin in particular. Conclusions: Although not statistically significant, our best estimates suggest an increased short-term risk of myocardial infarction in patients with CRS following macrolide prescription, supporting previous observational evidence. However, confounding by indication remains a possible explanation for this apparent increased risk. We found no evidence of longer term increased risks

    Expert panel process to optimise the design of a randomised controlled trial in chronic rhinosinusitis (the MACRO programme).

    Get PDF
    BACKGROUND: MACRO (Defining best Management for Adults with Chronic RhinOsinusitis) is an NIHR-funded programme of work designed to establish best practice for adults with chronic rhinosinusitis (CRS). The 7-year programme comprises three consecutive workstreams, designed to explore NHS care pathways through analysis of primary and secondary data sources, and to undertake a randomised controlled trial to evaluate a longer-term course of macrolide antibiotics and endoscopic sinus surgery for patients with CRS. A number of outstanding elements still required clarification at the funding stage. This paper reports an expert panel review process designed to agree and finalise the MACRO trial design, ensuring relevance to patients and clinicians whilst maximising trial recruitment and retention. METHODS: An expert panel, consisting of the MACRO Programme Management Group, independent advisors, and patient contributors, was convened to review current evidence and the mixed-method data collected as part of the programme, and reach agreement on MACRO trial design. Specifically, agreement was sought for selection of macrolide antibiotic, use of orally administered steroids, inclusion of CRS phenotypes (with/without nasal polyps), and overall trial design. RESULTS: A 12-week course of clarithromycin was agreed as the main trial comparator due to its increasing use as a first- and second-line treatment for patients with CRS, and the perceived need to establish its role in CRS management. Orally administered steroids will be used as a rescue medication during the trial, rather than routinely either pre or post trial randomisation, to limit any potential effects on surgical outcomes and better reflect current UK prescribing habits. Both CRS phenotypes will be included in a single trial to ensure that the MACRO trial is both pragmatic and generalisable to primary care. A modified, three-arm trial design was agreed after intense discussions and further exploratory work. Inclusion criteria were amended to ensure that the patients recruited would be considered eligible for the treatment offered in the trial due to having already received appropriate medical therapy as deemed suitable by their ENT surgeon. A proposed 6-week run-in period prior to randomisation was removed due to the new criteria prior to randomisation. CONCLUSION: The expert panel review process resulted in agreement on key elements and an optimal design for the MACRO trial, considered most likely to be successful in terms of both recruitment potential and ability to establish best management of patients with CRS

    Clarithromycin and endoscopic sinus surgery for adults with chronic rhinosinusitis with and without nasal polyps: study protocol for the MACRO randomised controlled trial.

    Get PDF
    BACKGROUND: Chronic rhinosinusitis (CRS) is a common source of ill health; 11% of UK adults reported CRS symptoms in a worldwide population study. Guidelines are conflicting regarding whether antibiotics should be included in primary medical management, reflecting the lack of evidence in systematic reviews. Insufficient evidence to inform the role of surgery contributes to a fivefold variation in UK intervention rates. The objective of this trial is to establish the comparative effectiveness of endoscopic sinus surgery (ESS) or a prolonged course of antibiotics (clarithromycin) in adult patients with CRS in terms of symptomatic improvement and costs to the National Health Service compared with standard medical care (intranasal medication) at 6 months. METHODS/DESIGN: A three-arm parallel-group trial will be conducted with patients who remain symptomatic after receiving appropriate medical therapy (either in primary or secondary care). They will be randomised to receive: (1) intranasal medication plus ESS, (2) intranasal medication plus clarithromycin (250 mg) or (3) intranasal medication plus a placebo. Intranasal medication (current standard medical care) is defined as a spray or drops of intranasal corticosteroids and saline irrigations. The primary outcome measure is the SNOT-22 questionnaire, which assesses disease-specific health-related quality of life. The study sample size is 600. Principal analyses will be according to the randomised groups irrespective of compliance. The trial will be conducted in at least 16 secondary or tertiary care centres with an internal pilot at six sites for 6 months. DISCUSSION: The potential cardiovascular side effects of macrolide antibiotics have been recently highlighted. The effectiveness of antibiotics will be established through this trial, which may help to reduce unnecessary usage and potential morbidity. If ESS is shown to be clinically effective and cost-effective, the trial may encourage earlier intervention. In contrast, if it is shown to be ineffective, then there should be a significant reduction in surgery rates. The trial results will feed into the other components of the MACRO research programme to establish best practice for the management of adults with CRS and design the ideal patient pathway across primary and secondary care. TRIAL REGISTRATION: ISRCTN36962030 . Registered on 17 October 2018
    • …
    corecore