685 research outputs found

    The Development of a Model of Audio Comfort in an Aviation Context

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    The Development of a Model of Audio Comfort in an Aviation Context – M.Aldridge The aim of this research was to develop a model of audio comfort. This model was developed to facilitate the comparison of different stimuli and their impact upon participants’ comfort. The thesis provides details of the human factors research undertaken as part of an Innovate UK funded project Improving the Propulsion Aerodynamics and Acoustics of Turboprop Aircraft (ImPAcTA) with Dowty Propellers. The thesis discusses the usage of the data obtained from this project in the development of a model of audio comfort. The thesis describes the initial stages in which the impact on cognitive performance and comfort are assessed in context of the physical properties of noise (Chapter 3). In this initial stage the results showed that there was a significant impact of both spectral content and decibel level on cognitive performance and reported discomfort. These results confirmed the efficacy of stimuli specific cognitive performance tasks in the measuring of discomfort when paired with a comfort questionnaire. With the usefulness of cognitive performance tasks being supported by the research carried out in Chapter the context in which noise was experienced was then examined (Chapter 4). To manipulate the context in which the noise was perceived the experiment varied the fidelity of a flight simulator. The results from this study showed that the reported immersion and presence participants experienced was related to both the comfort reported and task performance. The results demonstrated the need to consider the physical stimulus properties as well as environmental context and presentation methodologies in the assessment of comfort. The results also showed a significant impact of simulation fidelity on the assessment of comfort for an audio stimulus with consistent physical properties. The proposed model in this thesis is based on Rolls (1990) model of emotion. This model posits that there are parallels between comfort and emotion as defined by Rolls. In this model these parallels are based on the concepts of; elicitation of autonomic and endocrine responses, requirements to learn new and flexible behavioural responses to avoid/attain discomfort/comfort, motivation to take action, and facilitating communication. In the proposed model, comfort is represented as the centre of an x,y axis, movement on these axis are caused by the introduction or removal of primary or secondary reinforcers. Primary reinforcers refer to the experience of the discomfort stimuli while secondary reinforcers refers to the expectations a participant has of the stimuli and surrounding context. The impact of these reinforcers can be measured by cognitive task performance for primary reinforcers and perceived annoyance for secondary reinforcers. This model provides a novel method of predicting comfort that can be objectively measured and tested. The models assumptions were tested with use of both data collected previously (Chapter 4) and data from a new large scale study. Through the use of this data the assumptions of the model were confirmed with the model providing useful predictions of comfort from the metrics (Speech Identification Task, comfort questionnaire and Tanker Tracking Task) used

    Design of financial incentive interventions to improve lifestyle behaviors and health outcomes: A systematic review [version 1; peer review: awaiting peer review]

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    Background: Financial incentives may improve the initiation and engagement of behaviour change that reduce the negative outcomes associated with non-communicable diseases. There is still a paucity in guidelines or recommendations that help define key aspects of incentive-oriented interventions, including the type of incentive (e.g. cash rewards, vouchers), the frequency and magnitude of the incentive, and its mode of delivery. We aimed to systematically review the literature on financial incentives that promote healthy lifestyle behaviours or improve health profiles, and focused on the methodological approach to define the incentive intervention and its delivery. The protocol was registered at PROSPERO on 26 July 2018 (CRD42018102556). Methods: We sought studies in which a financial incentive was delivered to improve a health-related lifestyle behaviour (e.g., physical activity) or a health profile (e.g., HbA1c in people with diabetes). The search (which took place on March 3rd 2018) was conducted using OVID (MEDLINE and Embase), CINAHL and Scopus. Results: The search yielded 7,575 results and 37 were included for synthesis. Of the total, 83.8% (31/37) of the studies were conducted in the US, and 40.5% (15/37) were randomised controlled trials. Only one study reported the background and rationale followed to develop the incentive and conducted a focus group to understand what sort of incentives would be acceptable for their study population. There was a degree of consistency across the studies in terms of the direction, form, certainty, and recipient of the financial incentives used, but the magnitude and immediacy of the incentives were heterogeneous. Conclusions: The available literature on financial incentives to improve health-related lifestyles rarely reports on the rationale or background that defines the incentive approach, the magnitude of the incentive and other relevant details of the intervention, and the reporting of this information is essential to foster its use as potential effective interventions

    Four Eremophilane Sesquiterpenes from the Mangrove Endophytic Fungus Xylaria sp. BL321

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    Three new eremophilane sesquiterpenes (1–3) were isolated from the mangrove endophytic fungus Xylaria sp. BL321 together with 07H239-A (4), a known analogue of the new compounds. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. Compound 4 showed activation activity on α-glucosidase at 0.15 μM (146%), and then, 4 gradually produced inhibitory activity on α-glucosidase with increasing concentration, and the IC50 value is 6.54 μM

    Substrate-gated docking of pore subunit Tha4 in the TatC cavity initiates Tat translocase assembly

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    The twin-arginine translocase (Tat) transports folded proteins across tightly sealed membranes. cpTatC is the core component of the thylakoid translocase and coordinates transport through interactions with the substrate signal peptide and other Tat components, notably the Tha4 pore-forming component. Here, Cys–Cys matching mapped Tha4 contact sites on cpTatC and assessed the role of signal peptide binding on Tha4 assembly with the cpTatC–Hcf106 receptor complex. Tha4 made contact with a peripheral cpTatC site in nonstimulated membranes. In the translocase, Tha4 made an additional contact within the cup-shaped cavity of cpTatC that likely seeds Tha4 polymerization to form the pore. Substrate binding triggers assembly of Tha4 onto the interior site. We provide evidence that the substrate signal peptide inserts between cpTatC subunits arranged in a manner that conceivably forms an enclosed chamber. The location of the inserted signal peptide and the Tha4–cpTatC contact data suggest a model for signal peptide–gated Tha4 entry into the chamber to form the translocase

    Learning environments research in English classrooms

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    Although learning environments research has thrived for decades in many countries and school subjects, English classroom environment research is still in its infancy. This article paves the way for expanding research on English classroom environments by (1) reviewing the limited past research in English classrooms and (2) reporting the first study of English learning environments in Singaporean primary schools. For a sample of 441 grade 6 students, past research in other subjects was replicated in that a modified version of the What Is Happening In this Class? questionnaire was cross-validated, classroom environment was found to vary with the determinants of student sex and ethnicity, and associations emerged between students’ attitudes and the nature of the classroom environment

    Maternal nicotine exposure leads to decreased cardiac protein disulfide isomerase and impaired mitochondrial function in male rat offspring.

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    Smoking throughout pregnancy can lead to complications during gestation, parturition and neonatal development. Thus, nicotine replacement therapies are a popular alternative thought to be safer than cigarettes. However, recent studies in rodents suggest that fetal and neonatal nicotine exposure alone results in cardiac dysfunction and high blood pressure. While it is well known that perinatal nicotine exposure causes increased congenital abnormalities, the mechanisms underlying longer-term deficits in cardiac function are not completely understood. Recently, our laboratory demonstrated that nicotine impairs placental protein disulfide isomerase (PDI) triggering an increase in endoplasmic reticulum stress, leading us to hypothesize that this may also occur in the heart. At 3 months of age, nicotine-exposed offspring had 45% decreased PDI levels in the absence of endoplasmic reticulum stress. Given the association of PDI and superoxide dismutase enzymes, we further observed that antioxidant superoxide dismutase-2 levels were reduced by 32% in these offspring concomitant with a 26-49% decrease in mitochondrial complex proteins (I, II, IV and V) and tissue inhibitor of metalloproteinase-4, a critical matrix metalloprotease for cardiac contractility and health. Collectively, this study suggests that perinatal nicotine exposure decreases PDI, which can promote oxidative damage and mitochondrial damage, associated with a premature decline in cardiac function

    Identifying and Prioritizing Greater Sage-Grouse Nesting and Brood-Rearing Habitat for Conservation in Human-Modified Landscapes

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    BACKGROUND: Balancing animal conservation and human use of the landscape is an ongoing scientific and practical challenge throughout the world. We investigated reproductive success in female greater sage-grouse (Centrocercus urophasianus) relative to seasonal patterns of resource selection, with the larger goal of developing a spatially-explicit framework for managing human activity and sage-grouse conservation at the landscape level. METHODOLOGY/PRINCIPAL FINDINGS: We integrated field-observation, Global Positioning Systems telemetry, and statistical modeling to quantify the spatial pattern of occurrence and risk during nesting and brood-rearing. We linked occurrence and risk models to provide spatially-explicit indices of habitat-performance relationships. As part of the analysis, we offer novel biological information on resource selection during egg-laying, incubation, and night. The spatial pattern of occurrence during all reproductive phases was driven largely by selection or avoidance of terrain features and vegetation, with little variation explained by anthropogenic features. Specifically, sage-grouse consistently avoided rough terrain, selected for moderate shrub cover at the patch level (within 90 m(2)), and selected for mesic habitat in mid and late brood-rearing phases. In contrast, risk of nest and brood failure was structured by proximity to anthropogenic features including natural gas wells and human-created mesic areas, as well as vegetation features such as shrub cover. CONCLUSIONS/SIGNIFICANCE: Risk in this and perhaps other human-modified landscapes is a top-down (i.e., human-mediated) process that would most effectively be minimized by developing a better understanding of specific mechanisms (e.g., predator subsidization) driving observed patterns, and using habitat-performance indices such as those developed herein for spatially-explicit guidance of conservation intervention. Working under the hypothesis that industrial activity structures risk by enhancing predator abundance or effectiveness, we offer specific recommendations for maintaining high-performance habitat and reducing low-performance habitat, particularly relative to the nesting phase, by managing key high-risk anthropogenic features such as industrial infrastructure and water developments

    Drinking behaviours and blood alcohol concentration in four European drinking environments: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Reducing harm in drinking environments is a growing priority for European alcohol policy yet few studies have explored nightlife drinking behaviours. This study examines alcohol consumption and blood alcohol concentration (BAC) in drinking environments in four European cities.</p> <p>Methods</p> <p>A short questionnaire was implemented among 838 drinkers aged 16-35 in drinking environments in four European cities, in the Netherlands, Slovenia, Spain and the UK. Questions included self-reported alcohol use before interview and expected consumption over the remainder of the night. Breathalyser tests were used to measured breath alcohol concentration (converted to BAC) at interview.</p> <p>Results</p> <p>Most participants in the Dutch (56.2%), Spanish (59.6%) and British (61.4%) samples had preloaded (cf Slovenia 34.8%). In those drinking < 3 h at interview, there were no differences in BAC by gender or nationality. In UK participants, BAC increased significantly in those who had been drinking longer, reaching 0.13% (median) in females and 0.17% in males drinking > 5 h. In other nationalities, BAC increases were less pronounced or absent. High BAC (> 0.08%) was associated with being male, aged > 19, British and having consumed spirits. In all cities most participants intended to drink enough alcohol to constitute binge drinking.</p> <p>Conclusions</p> <p>Different models of drinking behaviour are seen in different nightlife settings. Here, the UK sample was typified by continued increases in inebriation compared with steady, more moderate intoxication elsewhere. With the former being associated with higher health risks, European alcohol policy must work to deter this form of nightlife.</p

    A self administered reliable questionnaire to assess lower bowel symptoms

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    <p>Abstract</p> <p>Background</p> <p>Bowel symptoms are considered indicators of the presence of colorectal cancer and other bowel diseases. Self administered questionnaires that elicit information about lower bowel symptoms have not been assessed for reliability, although this has been done for upper bowel symptoms. Our aim was to develop a self administered questionnaire for eliciting the presence, nature and severity of lower bowel symptoms potentially related to colorectal cancer, and assess its reliability.</p> <p>Methods</p> <p>Immediately before consulting a gastroenterologist or colorectal surgeon, 263 patients likely to have a colonoscopy completed the questionnaire. Reliability was assessed in two ways: by assessing agreement between patient responses and (a) responses given by the doctor at the consultation; and (b) responses given by patients two weeks later.</p> <p>Results</p> <p>There was more than 75% agreement for 78% of the questions for the patient-doctor comparison and for 92% of the questions for the patient-patient comparison. Agreement for the length of time a symptom was present, its severity, duration, frequency of occurrence and whether or not medical consultation had been sought, all had agreement of greater than 70%. Over all questions, the chance corrected agreement for the patient-doctor comparison had a median kappa of 65% (which represents substantial agreement), interquartile range 57–72%. The patient-patient comparison also showed substantial agreement with a median kappa of 75%, interquartile range 68–81%.</p> <p>Conclusion</p> <p>This self administered questionnaire about lower bowel symptoms is a useful way of eliciting details of bowel symptoms. It is a reliable instrument that is acceptable to patients and easily completed. Its use could guide the clinical consultation, allowing a more efficient, comprehensive and useful interaction, ensuring that all symptoms are assessed. It will also be a useful tool in research studies on bowel symptoms and their predictive value for colorectal cancer and other diseases. Studies assessing whether bowel symptoms predict the presence of colorectal cancer should provide estimates of the reliability of the symptom elicitation.</p

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
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