2,228 research outputs found

    Perdeuterated cyanobiphenyl liquid crystals for infrared applications

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    Perdeuterated 4'-pentyl-4-cyanobiphenyl (D5CB) was synthesized and its physical properties evaluated and compared to those of 5CB. D5CB retains physical properties similar to those of 5CB, such as phase transition temperatures, dielectric constants, and refractive indices. An outstanding feature of D5CB is that it exhibits a much cleaner and reduced infrared absorption. Perdeuteration, therefore, extends the usable range of liquid crystals to the mid infrared by significantly reducing the absorption in the near infrared, which is essential for telecom applications

    The Middle to Late Miocene “Carbonate Crash” in the Equatorial Indian Ocean

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    We integrate benthic foraminiferal stable isotopes, X‐ray fluorescence elemental ratios, and carbonate accumulation estimates in a continuous sedimentary archive recovered at International Ocean Discovery Program Site U1443 (Ninetyeast Ridge, Indian Ocean) to reconstruct changes in carbonate deposition and climate evolution over the interval 13.5 to 8.2 million years ago. Declining carbonate percentages together with a marked decrease in carbonate accumulation rates after ~13.2 Ma signal the onset of a prolonged episode of reduced carbonate deposition. This extended phase, which lasted until ~8.7 Ma, coincides with the middle to late Miocene carbonate crash, originally identified in the eastern equatorial Pacific Ocean and the Caribbean Sea. Interocean comparison reveals that intense carbonate impoverishment at Site U1443 (~11.5 to ~10 Ma) coincides with prolonged episodes of reduced carbonate deposition in all major tropical ocean basins. This implies that global changes in the intensity of chemical weathering and riverine input of calcium and carbonate ions into the ocean reservoir were instrumental in driving the carbonate crash. An increase in U1443 Log (Ba/Ti) together with a change in sediment color from red to green indicate a rise in organic export flux to the sea floor after ~11.2 Ma, which predates the global onset of the biogenic bloom. This early rise in export flux from biological production may have been linked to increased advection of nutrients and intensification of upper ocean mixing, associated with changes in the seasonality and intensity of the Indian Monsoon

    The role of fire in UK peatland and moorland management: the need for informed, unbiased debate

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    Fire has been used for centuries to generate and manage some of the UK's cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions

    Albumin versus balanced crystalloid for resuscitation in the treatment of sepsis:A protocol for a randomised controlled feasibility study, “ABC-Sepsis”

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    BACKGROUND: Patients presenting with suspected sepsis to secondary care often require fluid resuscitation to correct hypovolaemia and/or septic shock. Existing evidence signals, but does not demonstrate, a benefit for regimes including albumin over balanced crystalloid alone. However, interventions may be started too late, missing a critical resuscitation window. METHODS: ABC Sepsis is a currently recruiting randomised controlled feasibility trial comparing 5% human albumin solution (HAS) with balanced crystalloid for fluid resuscitation in patients with suspected sepsis. This multicentre trial is recruiting adult patients within 12 hours of presentation to secondary care with suspected community acquired sepsis, with a National Early Warning Score ≄5, who require intravenous fluid resuscitation. Participants are randomised to 5% HAS or balanced crystalloid as the sole resuscitation fluid for the first 6 hours. OBJECTIVES: Primary objectives are feasibility of recruitment to the study and 30-day mortality between groups. Secondary objectives include in-hospital and 90-day mortality, adherence to trial protocol, quality of life measurement and secondary care costs. DISCUSSION: This trial aims to determine the feasibility of conducting a trial to address the current uncertainty around optimal fluid resuscitation of patients with suspected sepsis. Understanding the feasibility of delivering a definitive study will be dependent on how the study team are able to negotiate clinician choice, Emergency Department pressures and participant acceptability, as well as whether any clinical signal of benefit is detected

    The protocol for the Be Our Ally Beat Smoking (BOABS) study, a randomised controlled trial of an intensive smoking cessation intervention in a remote Aboriginal Australian health care setting

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    Background: Australian Aboriginal peoples and Torres Strait Islanders (Indigenous Australians) smoke at much higher rates than non-Indigenous people and smoking is an important contributor to increased disease, hospital admissions and deaths in Indigenous Australian populations. Smoking cessation programs in Australia have not had the same impact on Indigenous smokers as on non-Indigenous smokers. This paper describes the protocol for a study that aims to test the efficacy of a locally-tailored, intensive, multidimensional smoking cessation program.\ud \ud Methods/Design: This study is a parallel, randomised, controlled trial. Participants are Aboriginal and Torres Strait Islander smokers aged 16 years and over, who are randomly allocated to a 'control' or 'intervention' group in a 2:1 ratio. Those assigned to the 'intervention' group receive smoking cessation counselling at face-to-face visits, weekly for the first four weeks, monthly to six months and two monthly to 12 months. They are also encouraged to attend a monthly smoking cessation support group. The 'control' group receive 'usual care' (i.e. they do not receive the smoking cessation program). Aboriginal researchers deliver the intervention, the goal of which is to help Aboriginal peoples and Torres Strait Islanders quit smoking. Data collection occurs at baseline (when they enrol) and at six and 12 months after enrolling. The primary outcome is self-reported smoking cessation with urinary cotinine confirmation at 12 months.\ud \ud Discussion: Stopping smoking has been described as the single most important individual change Aboriginal and Torres Strait Islander smokers could make to improve their health. Smoking cessation programs are a major priority in Aboriginal and Torres Strait Islander health and evidence for effective approaches is essential for policy development and resourcing. A range of strategies have been used to encourage Aboriginal peoples and Torres Strait Islanders to quit smoking however there have been few good quality studies that show what approaches work best. More evidence of strategies that could work more widely in Indigenous primary health care settings is needed if effective policy is to be developed and implemented. Our project will make an important contribution in this area.\ud \ud Trial Registration: Australian New Zealand Clinical Trials Registry (ACTRN12608000604303

    Investigating student teachers’ presentations of literacy and literacy pedagogy in a complex context

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    The field of literacy and primary literacy education is patterned by multiple discourses and this raises challenges for those educating the next generation of primary literacy teachers. In England, the last 15 years have seen considerable levels of prescription in the primary literacy curriculum and compliance by the school and teacher education sectors has been enforced through demanding accountability regimes. In this paper, the authors draw on findings of a small-scale interview study to consider how understandings of literacies associated with different contexts may or may not inflect student teachers’ orientations towards literacy provision in school. The authors explore how five student teachers presented their experiences of literacy within and beyond the classroom and how they seemed to position themselves in relation to literacy pedagogy. The authors focus particularly on continuities and discontinuities between literacies in the student teachers’ personal and professional lives, and on tensions they identified between the teachers they felt they wanted to, and were expected to, become. Reflecting on this work, the authors consider how they can best equip pre-service primary and early years teachers to develop as critical reflective literacy practitioners in the current context

    Developing a core outcome set for the health outcomes for children and adults with congenital oesophageal atresia and/or tracheo-oesophageal fistula: OCELOT task group study protocol

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    Introduction: Heterogeneity in reported outcomes of infants with oesophageal atresia (OA) with or without tracheo-oesophageal fistula (TOF) prevents effective data pooling. Core outcome sets (COS) have been developed for many conditions to standardise outcome reporting, facilitate meta-analysis and improve the relevance of research for patients and families. Our aim is to develop an internationally-agreed, comprehensive COS for OA-TOF, relevant from birth through to transition and adulthood. Methods and analysis: A long list of outcomes will be generated using (1) a systematic review of existing studies on OA-TOF and (2) qualitative research with children (patients), adults (patients) and families involving focus groups, semistructured interviews and self-reported outcome activity packs. A two-phase Delphi survey will then be completed by four key stakeholder groups: (1) patients (paediatric and adult); (2) families; (3) healthcare professionals; and (4) researchers. Phase I will include stakeholders individually rating the importance and relevance of each long-listed outcome using a 9-point Likert scale, with the option to suggest additional outcomes not already included. During phase II, stakeholders will review summarised results from phase I relative to their own initial score and then will be asked to rescore the outcome based on this information. Responses from phase II will be summarised using descriptive statistics and a predefined definition of consensus for inclusion or exclusion of outcomes. Following the Delphi process, stakeholder experts will be invited to review data at a consensus meeting and agree on a COS for OA-TOF. Ethics and dissemination: Ethical approval was sought through the Health Research Authority via the Integrated Research Application System, registration no. 297026. However, approval was deemed not to be required, so study sponsorship and oversight were provided by Alder Hey Children’s NHS Foundation Trust. The study has been prospectively registered with the COMET Initiative. The study will be published in an open access forum
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