764 research outputs found

    A Mobile App Delivering a Gamified Battery of Cognitive Tests Designed for Repeated Play (OU Brainwave): App Design and Cohort Study

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    Background: Mobile phone and tablet apps are an increasingly common platform to collect data. A key challenge for researchers has been participant “buy-in” and participant attrition for designs requiring repeated testing. Objective: The objective of this study was to develop and asses the utility of 1 – 2 minute versions of both classic and novel cognitive tasks within a user focussed and driven mobile phone and tablet app designed to encourage repeated play. Methods: A large sample (N = 13,979 at first data collection) participated in multiple, self-paced, sessions of working memory (N-back), spatial cognition (Mental rotation), sustained attentional focus (Persistent Vigilance task), and split attention (Multiple object tracking) tasks along with an implementation of a novel action learning task. A full morningness-eveningness questionnaire was also included. Data was collected across an 18 month period. While the app prompted reengagement at set intervals, each participant was free to repeatedly complete each task as many times as they wished. Results: We found a significant relationship between morningness and age (r = 0.298, n = 12755, p Conclusions: Using extremely short testing periods and permitting participants to decide their own level of engagement - both in terms of which gamified task they played, and how many sessions they completed - we were able to collect a substantial and valid dataset. We suggest that the success of OU brainwave should inform future research oriented apps - particularly in issues around balancing participant engagement with data fidelity

    Re-estimation of argon isotope ratios leading to a revised estimate of the Boltzmann constant

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    In 2013, NPL, SUERC and Cranfield University published an estimate for the Boltzmann constant [1] based on a measurement of the limiting low-pressure speed of sound in argon gas. Subsequently, an extensive investigation by Yang et al [2] revealed that there was likely to have been an error in the estimate of the molar mass of the argon used in the experiment. Responding to [2], de Podesta et al revised their estimate of the molar mass [3]. The shift in the estimated molar mass, and of the estimate of kB, was large: -2.7 parts in 106, nearly four times the original uncertainty estimate. The work described here was undertaken to understand the cause of this shift and our conclusion is that the original samples were probably contaminated with argon from atmospheric air.
 In this work we have repeated the measurement reported in [1] on the same gas sample that was examined in [2, 3]. However in this work we have used a different technique for sampling the gas that has allowed us to eliminate the possibility of contamination of the argon samples. We have repeated the sampling procedure three times, and examined samples on two mass spectrometers. This procedure confirms the isotopic ratio estimates of Yang et al [2] but with lower uncertainty, particularly in the relative abundance ratio R38:36.
 Our new estimate of the molar mass of the argon used in Isotherm 5 in [1] is 39.947 727(15) g mol-1 which differs by +0.50 parts in 106 from the estimate 39.947 707(28) g mol-1 made in [3]. This new estimate of the molar mass leads to a revised estimate of the Boltzmann constant of kB = 1.380 648 60 (97) × 10−23 J K−1 which differs from the 2014 CODATA value by +0.05 parts in 106.&#13

    The positive predictive value of stroke identification by ambulance clinicians in North East England: a retrospective cohort study

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    Introduction/background Accurate prehospital identification of patients who had an acute stroke enables rapid conveyance to specialist units for time-dependent treatments such as thrombolysis and thrombectomy. Misidentification leads to patients who had a ‘stroke mimic’ (SM) being inappropriately triaged to specialist units. We evaluated the positive predictive value (PPV) of prehospital stroke identification by ambulance clinicians in the North East of England. Methods This service evaluation linked routinely collected records from a UK regional ambulance service identifying adults with any clinical impression of suspected stroke to diagnostic data from four National Health Service hospital trusts between 1 June 2013 and 31 May 2016. The reference standard for a confirmed stroke diagnosis was inclusion in Sentinel Stroke National Audit Programme data or a hospital diagnosis of stroke or transient ischaemic attack in Hospital Episode Statistics. PPV was calculated as a measure of diagnostic accuracy. Results Ambulance clinicians in North East England identified 5645 patients who had a suspected stroke (mean age 73.2 years, 48% male). At least one Face Arm Speech Test (FAST) symptom was documented for 93% of patients who had a suspected stroke but a positive FAST was only documented for 51%. Stroke, or transient ischaemic attack, was the final diagnosis for 3483 (62%) patients. SM (false positives) accounted for 38% of suspected strokes identified by ambulance clinicians and included a wide range of non-stroke diagnoses including infections, seizures and migraine. Discussion In this large multisite data set, identification of patients who had a stroke by ambulance clinicians had a PPV rate of 62% (95% CI 61 to 63). Most patients who had a suspected stroke had at least one FAST symptom, but failure to document a complete test was common. Training for stroke identification and SM rates need to be considered when planning service provision and capacity. http://dx.doi.org/10.1136/emermed-2019-208902. This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0

    A survey of UK paramedics’ views about their stroke training, current practice and the identification of stroke mimics

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    Aims ‐ Paramedics play a crucial role in identifying patients with suspected stroke and transporting them to appropriate acute care. Between 25% and 50% of suspected stroke patients are later diagnosed with a condition other than stroke known as a ‘stroke mimic’. If stroke mimics could be identified in the pre-hospital setting, unnecessary admissions to stroke units could potentially be avoided. This survey describes UK paramedics’ stroke training and practice, their knowledge about stroke mimic conditions and their thoughts about pre-hospital identification of these patients.Methods ‐ An online survey invitation was circulated to members within the UK College of Paramedics and promoted through social media (8 September 2016 and 23 October 2016). Topics included: stroke training; assessment of patients with suspected stroke; local practice; and knowledge about and identification of stroke mimics.Results ‐ There were 271 responses. Blank responses (39) and non-paramedic (1) responses were removed, leaving 231 responses from paramedics which equates to 2% of College of Paramedics membership and 1% of Health and Care Professions Council registered paramedics. The majority of respondents (78%) thought that they would benefit from more training on pre-hospital stroke care. Narrative comments focused on a desire to improve the assessment of suspected stroke patients and increase respondents’ knowledge about atypical stroke presentations and current stroke research. The Face Arm Speech Test was used by 97% of respondents to assess suspected stroke patients, although other tools such as Recognition of Stroke in the Emergency Room (17%) and Miami Emergency Neurological Deficit (11%) were also used. According to those responding, 50% of stroke patients were taken to emergency departments, 35% went straight to a stroke ward and 8% were taken directly to CT scan. Most respondents (65%) were aware of the term ‘stroke mimic’. Two-thirds of respondents (65%) thought a tool that predicted the likelihood of a suspected stroke being a stroke mimic would be useful in pre-hospital care.Conclusion ‐ This study reports a survey of UK paramedics’ views about the stroke care they provide. Conclusions are limited by the low number of responses. Assessment of suspected stroke patients was recognised as an important skill by paramedics and an area where many would like further training. Respondents’ current practice varied in terms of the stroke assessment tools used and whether suspected stroke patients were taken to the emergency department or direct to a stroke ward. A stroke mimic identification tool would be useful if it allowed stroke mimic patients to be directed to appropriate care, but it would need to have a high level of specificity and not adversely impact on time to treatment for true stroke patients

    The frequency, characteristics and aetiology of stroke mimic presentations::a narrative review

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    A significant proportion of patients with acute stroke symptoms have an alternative ‘mimic’ diagnosis. A narrative review was carried out to explore the frequency, characteristics and aetiology of stroke mimics. Prehospital and thrombolysis-treated patients were described separately. Overall, 9972 studies were identified from the initial search and 79 studies were included with a median stroke mimic rate of 19% (range: 1–64%). The prehospital median was 27% (range: 4–43%) and the thrombolysis median 10% (range: 1–25%). Seizures, migraines and psychiatric disorders are the most frequently reported causes of stroke mimics. Several characteristics are consistently associated with stroke mimics; however, they do not fully exclude the possibility of stroke. Nineteen per cent of suspected stroke patients had a mimic condition. Stroke mimics were more common with younger age and female sex. The range of mimic diagnoses, a lack of clear differentiating characteristics and the short treatment window for ischaemic stroke create challenges for early identification

    Development and validation of a pragmatic prehospital tool to identify stroke mimic patients

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    Aim Stroke mimics (SM) are non-stroke conditions producing stroke-like symptoms. Prehospital stroke identification tools prioritise sensitivity over specificity.1 It is estimated that >25% of prehospital suspected stroke patients are SM.2 Failure to identify SM creates inefficient use of ambulances and specialist stroke services. We developed a pragmatic tool to identify SM amongst suspected prehospital stroke patients. Method The tool was developed using regression analysis of clinical variables documented in ambulance records of suspected stroke patients linked to primary hospital diagnoses (derivation dataset, n=1,650, 40% SM).3 It was refined using feedback from paramedics (n=3) and hospital clinicians (n=9), and analysis of an expanded prehospital derivation dataset (n=3,797, 41% SM (original 1650 patients included)). Results The STEAM tool combines six variables: 1 point for Systolic blood pressure 38.5°C with Abstracts A2 BMJ Open 2018;8(Suppl 1):A1–A34 (NHS). Protected by copyright. on 14 August 2019 at Manchester University NHS Foundation Trust http://bmjopen.bmj.com/ BMJ Open: first published as 10.1136/bmjopen-2018-EMS.6 on 16 April 2018. Downloaded from heart rate >90 bpm; 1 point for seizures or 2 points for seizures with known diagnosis of Epilepsy; 1 point for Age <40 years or 2 points for age <30 years; 1 point for headache with known diagnosis of Migraine; 1 point for FAST-ve. A score of 2 on STEAM predicted SM diagnosis in the derivation dataset with 5.5% sensitivity, 99.6% specificity and positive predictive value (PPV) of 91.4%. External validation (n=1,848, 33% SM) showed 5.5% sensitivity, 99.4% specificity and a PPV of 82.5%. Conclusion STEAM uses common clinical characteristics to identify SM patients with high certainty. The benefits of using STEAM to reduce SM admissions to stroke services need to be weighed up against delayed admissions for stroke patients wrongly identified as SM. https://bmjopen.bmj.com/content/8/Suppl_1/A2.3 This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ http://dx.doi.org/10.1136/bmjopen-2018-EMS.

    Against the Cold War : the nature and traditions of pro-Soviet sentiment in the British Labour Party 1945-89.

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    Ideas and ideological attachments are a powerful motivating force over political activity. This thesis studies how a group of British Labour parliamentarians developed an ideological link to the Soviet Union and how this attachment acted as a prism through which they viewed the world. This led to an opposition to the Cold War to develop that was sympathetic to the objectives of the Soviet Union. This led pro-Sovietism to become an established, but minority, tradition of British socialism. This is explored through a study of the ideals and activities associated with these beliefs by focussing on individual MPs. Using MPs as case studies, and studying them within the context of a period of the Cold War, we are able to understand how their activism became reactive to international relations and how their ideas filtered into developing traditions within the party's left-wing. The thesis rejects the notion that those who engaged in pro-Soviet activism were agents of the Soviet Union and crypto-Communists and develops a framework within which these figures can be understood as principled socialists who shared the objectives of preventing an escalation of the Cold War and establishing a socialist future

    Study of the interrelationship between weld geometry, process variables and joint intergrity for friction processed AA6082-T6 aluminium

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    This work presents a broad overview of the successful development of friction taper stud welding (FTSW) in 25mm thick AA6082-T6 sections. It covers the selection of geometry and process parameters, the development of data logging equipment, energy input results and interpretations. Research was carried out to develop the FTSW process for application in 25mm AA6082-T6 sections. The development and application of the FTSW process addresses the need to fill blind holes in thick aluminium sections for the repair of incorrectly drilled holes, friction stir welding exit holes and defects in critical components. During welding, frictional torque, rotational speed, axial force, near interface temperature of the tapered hole and welding time was recorded. This data was used to calculate energy input and energy input rates throughout a weld, enabling the effect of process parameters to be linked to energy, temperature, microhardness and static joint strength. Results of preliminary experiments are included in the study that were used for the design of a process parameter test window for FTSW in AA6082-T6, as no parameters were available to indicate a starting point for the research. The effect of process parameters on the static joint strength at the base of the tapered hole are presented; using a parallel sided stud and tapered hole configuration. This addresses one of the pressing issues facing FTSW of AA6082-T6, namely the lack of bonding at the bottom of the blind hole. A final process parameter matrix is designed based on the process development welds and is presented and discussed. In addition, the use of a non-consumable heat sink was investigated to prevent the premature collapse of the stud during welding and was shown to be critically important to the FTSW of AA6082-T6. To achieve good sidewall bonding a hole taper angle of 60° is required, this having been shown during visual evaluation of development welds. Stud taper angles between 2° and 5° less than the taper angle of the hole were identified as the range within which good FTSW can be made. With this geometry, at no stage during welding did the body of the stud shear off from the weld interface due to softening, thereby preventing collapse of the stud and formation of poorly bonded regions at the sidewall of the hole. The absence of shearing off of the weld interface during plunge was shown to be a good indicator of appropriate geometry and can be linked to welds made with high hole and stud taper angles and high axial force ramp up rates. The large hole and stud diameter relative to the depth of the hole and the large taper angle of the hole further aid in keeping the weld nugget rotating in the hole, promoting plasticization of the sidewall. Axial force ramp up rate was found to be the main critical success factor in an AA6082-T6 FTSW. Without control of this parameter the body of the stud will heat and detrimentally soften during plunge. It was established that good FTSW in AA6082-T6 cannot be made without the use of preheat to overcome the heat dissipation during welding, and is directly linked to improved energy input characteristics. Energy input as well as energy input rate were directly linked to static tensile strength and softening in the HAZ. The angle of the stud has been related to the energy input rate limit of the stud body, with increasing stud taper angles enabling the stud to withstand a higher energy input rate, allowing the weld interface to propagate up the hole at a slower rate, promoting plasticization of the sidewall. This study has successfully made good FTSW in 25mm thick AA6082-T6, in a 60°, 20mm deep tapered hole. Process parameters and ranges that produce FTSW exhibiting the required characteristics were identified by this study

    Emergency supply of prescription-only medicines to patients by community pharmacists: a mixed methods evaluation incorporating patient, pharmacist and GP perspectives

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    Objective To evaluate and inform emergency supply of prescription-only medicines by community pharmacists (CPs), including how the service could form an integral component of established healthcare provision to maximise adherence. Design Mixed methods. 4 phases: prospective audit of emergency supply requests for prescribed medicines (October–November 2012 and April 2013); interviews with CPs (February–April 2013); follow-up interviews with patients (April–May 2013); interactive feedback sessions with general practice teams (October–November 2013). Setting 22 community pharmacies and 6 general practices in Northwest England. Participants 27 CPs with experience of dealing with requests for emergency supplies; 25 patients who received an emergency supply of a prescribed medicine; 58 staff at 6 general practices. Results Clinical audit in 22 pharmacies over two 4-week periods reported that 526 medicines were requested by 450 patients. Requests peaked over a bank holiday and around weekends. A significant number of supplies were made during practice opening hours. Most requests were for older patients and for medicines used in long-term conditions. Difficulty in renewing repeat medication (forgetting to order, or prescription delays) was the major reason for requests. The majority of medicines were ‘loaned’ in advance of a National Health Service (NHS) prescription. Interviews with CPs and patients indicated that continuous supply had a positive impact on medicines adherence, removing the need to access urgent care. General practice staff were surprised and concerned by the extent of emergency supply episodes. Conclusions CPs regularly provide emergency supplies to patients who run out of their repeat medication, including during practice opening hours. This may aid adherence. There is currently no feedback loop, however, to general practice. Patient care and interprofessional communication may be better served by the introduction of a formally structured and funded NHS emergency supply service from community pharmacies, with ongoing optimisation of repeat prescribing
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