364 research outputs found

    Cascade diagrams for depicting complex interventions in randomised trials

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    Clarity about how trial interventions are delivered is important for researchers and those who might want to use their results. A new graphical representation aims to help make complex interventions clearer. Many medical interventions—particularly non-pharmacological ones—are complex, consisting of multiple interacting components targeted at different organisational levels. Published descriptions of complex interventions often do not contain enough detail to enable their replication. Reports of behaviour change interventions should include descriptions of setting, mode, intensity, and duration, and characteristics of the participants. Graphical methods, such as that showing the relative timing of assessments and intervention components, may improve clarity of reporting. However, these approaches do not reveal the connections between the different “actors” in a complex intervention.8 Different audiences may want different things from a description of an intervention, but visualising relationships between actors can clarify crucial features such as the fidelity with which the intervention is passed down a chain of actors and possible routes of contamination between treatment arms. Here we describe a new graphical approach—the cascade diagram—that highlights these potential problems

    The death of massive stars - II. Observational constraints on the progenitors of type Ibc supernovae

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    The progenitors of many type II core-collapse supernovae have now been identified directly on pre-discovery imaging. Here we present an extensive search for the progenitors of type Ibc supernovae in all available pre-discovery imaging since 1998. There are 12 type Ibc supernovae with no detections of progenitors in either deep ground-based or Hubble Space Telescope archival imaging. The deepest absolute BVR magnitude limits are between -4 and -5. We compare these limits with the observed Wolf-Rayet population in the Large Magellanic Cloud and estimate a 16 per cent probability we have failed to detect such a progenitor by chance. Alternatively the progenitors evolve significantly before core-collapse or we have underestimated the extinction towards the progenitors. Reviewing the relative rates and ejecta mass estimates from lightcurve modelling of Ibc SNe, we find both incompatible with Wolf-Rayet stars with initial masses >25Msun being the only progenitors. We present binary evolution models that fit these observational constraints. Stars in binaries with initial masses <20Msun lose their hydrogen envelopes in binary interactions to become low mass helium stars. They retain a low mass hydrogen envelope until approximately 10,000 years before core-collapse; hence it is not surprising that galactic analogues have been difficult to identify.Comment: Accepted by MNRAS. 31 pages, 12 figures, 8 table

    Interpreting high [O III]/H β ratios with maturing starbursts

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    Star-forming galaxies at high redshift show ubiquitously high-ionization parameters, as measured by the ratio of optical emission lines. We demonstrate that local (z < 0.2) sources selected as Lyman break analogues also manifest high line ratios with a typical [O III]/Hβ=3.36+0.14−0.04 – comparable to all but the highest ratios seen in star-forming galaxies at z ∼ 2–4. We argue that the stellar population synthesis code BPASS can explain the high-ionization parameters required through the ageing of rapidly formed star populations, without invoking any AGN contribution. Binary stellar evolution pathways prolong the age interval over which a starburst is likely to show elevated line ratios, relative to those predicted by single stellar evolution codes. As a result, model galaxies at near-solar metallicities and with ages of up to ∼100 Myr after a starburst typically have a line ratio [O III]/Hβ ∼ 3, consistent with those seen in Lyman break galaxies and local sources with similar star formation densities. This emphasises the importance of including binary evolution pathways when simulating the nebular line emission of young or bursty stellar populations

    Effectiveness and cost-effectiveness of a novel, group self-management course for adults with chronic musculoskeletal pain: study protocol for a multicentre, randomised controlled trial (COPERS)

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    Introduction: Chronic musculoskeletal pain is a common condition that often responds poorly to treatment. Self-management courses have been advocated as a non-drug pain management technique, although evidence for their effectiveness is equivocal. We designed and piloted a self-management course based on evidence for effectiveness for specific course components and characteristics. Methods/analysis: COPERS (coping with persistent pain, effectiveness research into self-management) is a pragmatic randomised controlled trial testing the effectiveness and cost-effectiveness of an intensive, group, cognitive behavioural-based, theoretically informed and manualised self-management course for chronic pain patients against a control of best usual care: a pain education booklet and a relaxation CD. The course lasts for 15 h, spread over 3 days, with a –2 h follow-up session 2 weeks later. We aim to recruit 685 participants with chronic musculoskeletal pain from primary, intermediate and secondary care services in two UK regions. The study is powered to show a standardised mean difference of 0.3 in the primary outcome, pain-related disability. Secondary outcomes include generic health-related quality of life, healthcare utilisation, pain self-efficacy, coping, depression, anxiety and social engagement. Outcomes are measured at 6 and 12 months postrandomisation. Pain self-efficacy is measured at 3 months to assess whether change mediates clinical effect. Ethics/dissemination: Ethics approval was given by Cambridgeshire Ethics 11/EE/046. This trial will provide robust data on the effectiveness and cost-effectiveness of an evidence-based, group self-management programme for chronic musculoskeletal pain. The published outcomes will help to inform future policy and practice around such self-management courses, both nationally and internationally. Trial registration: ISRCTN24426731

    Adaptive Stand Up Paddleboard

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    The task of this project was to create an adaptive paddleboard capable of being ridden by someone who does not have full mobility in one or more of their lower extremities. This project was worked on by a team of five students - three mechanical engineers and two kinesiology students - to create an effective and robust design for the client. To do this, the team regularly met with the client and used individual and group expertise in various fields to bring the best product to the end user. The client, Damien, was a firefighter who was injured in July 2015 after a tree fell on him while he was on duty. The incident left Damien with an incomplete spinal cord injury at level T12 and L1. An incomplete spinal cord injury differs from a complete spinal cord injury in that the spinal cord is not completely severed; instead, due to vertebrae compression or fracture, the axons of a nerve are crushed or destroyed, affecting the ability of motor or sensory information to be transmitted to the brain. However, because of the incomplete nature of the injury, some motor and sensory function is still preserved. The extent of sensory and/or motor preservation is highly varied from person to person because of the difference in the amount of damage on each person’s nerve fibers. Injuries to the L1 vertebrae commonly result in mild loss of function in the hips and legs. As is typical with these types of thoracic injuries, Damien retained full function and strength in his arms and hands. Damien began working on strengthening his legs and reestablishing patterned neural activity in the Central Nervous System (CNS) through intensive therapy at Project Walk in the third quarter of 2015. The therapy is an intensive physical therapy regime; with the goal of being able to walk by the time his therapy is completed. The project was meant to be used by the client for the entirety of his therapy and beyond. For this, the team went through many designs and ideas before all settling on one style, a rear folding, low profile support that could assist the client in a standing position. This design went through a multitude of design changes and iterations as proof of concept tests and analysis was done throughout the year. Consultation with the client, sponsors, advisors, and those interested in the project or working on something similar were paramount helping the team finalize the design. The final chosen design is a modified version of the preliminary selected design. Upon presenting the final preliminary design to Damien, the team received valuable feedback regarding how he planned to use the board, as well as his progress in his ability to move his legs. The largest change Damien wanted to see in the design was the addition of a seating position on the board, which became a focus for the team. Furthermore, Damien expressed how he was very comfortable using dip bars to move his body up and down, as this is a very common movement for wheelchair users. The team took this feedback, in addition to other items, and integrated them into the design in an attempt to create the product so it uniquely fit Damien’s desires. One major breakthrough on the project was that of the insert design used to attach the structure to the board. Through research into methods to attaching structures to prefabricated paddleboards, there was no basis that could be found, as most products of this type were made building custom boards. For this project, and the help of SUP Think Tank and Ding King Surfboard Repair, the team used the “top hat” method, which consists of the following order for each of the four insert locations: two layers of carbon fiber sheets, three layers of 4 oz. fiberglass sheets, the wooden inserts, and then three more layers of 4 oz. fiberglass. Another major recognition was that of automated machining, where using CNC machines became a major help when having tried and failed and hand machining certain aspect of this project. All of this lead to the final design for the adaptive stand up paddleboard project. The final design consists of three positions, kneeling, sitting, and standing. Movement between these positions is possible with the use of the dip bars Damien suggested, and the low profile idea from the initial concept was kept. This low profile concept allows the standing and sitting support to fold down against the paddleboard, also clearing room for a more comfortable kneeling position. The entire project was made marine compatible, with the structure being made of anodized aluminum, nylon straps, and stainless steel bolts and pins. This design was made modular, so it could be removed from the board if necessary, allowing the paddleboard to progress with the client throughout his recovery and more, assisting him in all areas necessary

    Improving Productivity through Strategic Alignment of Competitive Capabilities

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    Purpose The purpose of this paper is to investigate the productivity performance at the firm level from the perspective of manufacturing capability development at the process level. Moreover, it reveals how alignment of manufacturing capabilities with market requirements has influenced a firm’s productivity over a period that includes the 2008 global recession. Design/methodology/approach A conceptual framework was derived from established theories and employed as part of a case study design encompassing a multiple methods research approach. The case of a UK SME was selected to reflect some of the issues associated with the wider productivity stagnation experienced by the UK economy in recent years. Findings The firm’s manufacturing strategy had become incrementally misaligned with market requirements due to external changes in its business environment. The complex relationships between capabilities such as quality, speed and cost were characterised. Realigning the firm’s manufacturing strategy to regain productivity performance required a range of prioritised actions including capital investment and changes in management practices concerning bottom-up process improvement and regular, top-down strategy review. Research limitations/implications The findings of the case study cannot be generalised and the outcomes are specific to just one firm. However, the approach lends itself to replication, particularly within SMEs. Originality/value Prior studies have focussed on capability development at higher levels of abstraction. The study operationalized established theoretical perspectives at the firm level to derive context-based outcomes that can be used to improve manufacturing strategy alignment and productivity. Furthermore, the study contributes empirical evidence from the SME sector to the ongoing debate regarding the UK’s productivity puzzle

    An approach to estimating rockfish biomass based on larval production, with application to Sebastes jordani

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    An assessment of the total biomass of shortbelly rockfish (Sebastes jordani) off the central California coast is presented that is based on a spatially extensive but temporally restricted ichthyoplankton survey conducted during the 1991 spawning season. Contemporaneous samples of adults were obtained by trawl sampling in the study region. Daily larval production (7.56 × 1010 larvae/d) and the larval mortality rate (Z=0.11/d) during the cruise were estimated from a larval “catch curve,” wherein the logarithm of total age-specific larval abundance was regressed against larval age. For this analysis, larval age compositions at each of the 150 sample sites were determined by examination of otolith microstructure from subsampled larvae (n=2203), which were weighted by the polygonal Sette-Ahlstrom area surrounding each station. Female population weight-specific fecundity was estimated through a life table analysis that incorporated sex-specific differences in adult growth rate, female maturity, fecundity, and natural mortality (M). The resulting statistic (102.17 larvae/g) was insensitive to errors in estimating M and to the pattern of recruitment. Together, the two analyses indicated that a total biomass equal to 1366 metric tons (t)/d of age-1+ shortbelly rockfish (sexes combined) was needed to account for the observed level of spawning output during the cruise. Given the long-term seasonal distribution of spawning activity in the study area, as elucidated from a retrospective examination of California Cooperative Oceanic Fisheries Investigation (CalCOFI) ichthyoplankton samples from 1952 to 1984, the “daily” total biomass was expanded to an annual total of 67,392 t. An attempt to account for all sources of error in the derivation of this estimate was made by application of the delta-method, which yielded a coefficient of variation of 19%. The relatively high precision of this larval production method, and the rapidity with which an absolute biomass estimate can be obtained, establishes that, for some species of rockfish (Sebastes spp.), it is an attractive alternative to traditional age-structured stock assessments

    Effectiveness of financial incentives to improve adherence to maintenance treatment with antipsychotics: cluster randomised controlled trial

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    Objective: To test whether offering financial incentives to patients with psychotic disorders is effective in improving adherence to maintenance treatment with antipsychotics. Design: Cluster randomised controlled trial. Setting: Community mental health teams in secondary psychiatric care in the United Kingdom. Participants: Patients with a diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder, who were prescribed long acting antipsychotic (depot) injections but had received 75% or less of the prescribed injections. We randomly allocated 73 teams with a total of 141 patients. Primary outcome data were available for 35 intervention teams with 75 patients (96% of randomised) and for 31 control teams with 56 patients (89% of randomised). Interventions: Participants in the intervention group were offered £15 (€17; $22) for each depot injection over a 12 month period. Participants in the control condition received treatment as usual. Main outcome measure: The primary outcome was the percentage of prescribed depot injections given during the 12 month intervention period. Results 73 teams with 141 consenting patients were randomised, and outcomes were assessed for 131 patients (93%).⇓ Average baseline adherence was 69% in the intervention group and 67% in the control group. During the 12 month trial period adherence was 85% in the intervention group and 71% in the control group. The adjusted effect estimate was 11.5% (95% confidence interval 3.9% to 19.0%, P=0.003). A secondary outcome was an adherence of ≥95%, which was achieved in 28% of the intervention group and 5% of the control group (adjusted odds ratio 8.21, 95% confidence interval 2.00 to 33.67, P=0.003). Although differences in clinician rated clinical improvement between the groups failed to reach statistical significance, patients in the intervention group had more favourable subjective quality of life ratings (β=0.71, 95% confidence interval 0.26 to 1.15, P=0.002). The number of admissions to hospital and adverse events were low in both groups and did not show substantial differences. Conclusion: Offering modest financial incentives to patients with psychotic disorders is an effective method for improving adherence to maintenance treatment with antipsychotics

    Prevalence and impact of chronic widespread pain in the Bangladeshi and White populations of Tower Hamlets, East London

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    The prevalence and impact of chronic pain differ between ethnic groups. We report a study of the comparative prevalence and impact of chronic pain in Bangladeshi, British Bangladeshi and White British/Irish people. We posted a short questionnaire to a random sample of 4,480 patients registered with 16 general practices in the London Borough of Tower Hamlets and conducted a longer questionnaire with patients in the waiting areas at those practices. We distinguished between Bangladeshi participants who were born in the UK or had arrived in the UK at the age of 14 or under (British Bangladeshi) and those who arrived in UK at the age of over 14 (Bangladeshi). We obtained 1,223/4,480 (27 %) responses to the short survey and 600/637 (94 %) to the long survey. From the former, the prevalence of chronic pain in the White, British Bangladeshi and Bangladeshi groups was 55, 54 and 72 %, respectively. The corresponding figures from the long survey were 49, 45 and 70 %. Chronic widespread pain was commoner in the Bangladeshi (16 %) than in the White (10 %) or British Bangladeshi (9 %) groups. People with chronic pain experienced poorer quality of life (odds ratio for scoring best possible health vs. good health (or good vs. poor health) 5.6 (95 % confidence interval 3.4 to 9.8)), but we found no evidence of differences between ethnic groups in the impact of chronic pain on the quality of life. Chronic pain is commoner and, of greater severity, in Bangladeshis than in Whites. On most measures in this study, British Bangladeshis resembled the Whites more than the Bangladeshis

    New product introduction and supplier integration in sales and operations planning:evidence from the Asia Pacific region

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    Purpose: This paper investigates the implementation and performance benefits of Sales and Operations Planning (S&OP) within organizations in Asia Pacific. Design/methodology/approach: A case study method was used, with two companies selected. The first company had recently commenced S&OP and applied it to facilitate New Product Introduction, while the second had integrated its supplier into an existing S&OP program. Supply chain performance data was collected and analyzed in the context of an S&OP maturity framework. Findings: Both cases show significant improvements in supply chain performance. In one case, the implementation of a common form of S&OP resulted in a 67% reduction in order lead time for newly introduced products. The second case demonstrated a 30% reduction in inventory levels and a 52% improvement in forecast accuracy through more advanced S&OP processes. Research limitations/implications: This paper studies just two companies and is not intended to be representative of outcomes at all companies implementing S&OP. Further studies are required for a more generalized picture of S&OP implementations in the Asia Pacific region to emerge. Practical implications: The findings illustrate the potential quantitative benefits of adopting S&OP and the circumstances under which these benefits may be achieved. The results are also supportive of the notion of a maturity model for S&OP implementations. Originality/value: This paper strengthens the link between practitioner and academic literature by providing empirical evidence of the benefits of S&OP. Furthermore, the findings are derived from the Asia Pacific region for which there have been few academic studies on S&OP to date
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