112 research outputs found

    Automatic Methods for Hiding Latency in Parallel and Distributed Computation

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    In this paper we describe methods for mitigating the degradation in performance caused by high latencies in parallel and distributed networks. For example, given any dataflow type of algorithm that runs in T steps on an n-node ring with unit link delays, we show how to run the algorithm in O(T) steps on any n-node bounded-degree connected network with average link delay O(1). This is a significant improvement over prior approaches to latency hiding, which require slowdowns proportional to the maximum link delay. In the case when the network has average link delay dave, our simulation runs in O(√daveT) steps using n/√dave processors, thereby preserving efficiency. We also show how to efficiently simulate an n × n array with unit link delays using slowdown Õ (d&frac23ave) on a two-dimensional array with average link delay dave. Last, we present results for the case in which large local databases are involved in the computation

    Inclusion of people with multiple long-term conditions in pregnancy research:patient, public and stakeholder involvement and engagement in a randomised controlled trial

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    Background: Both pregnant women and those with multiple long-term conditions are under-served groups in clinical research. Informing and improving research through patient and public involvement, including pregnant women with two or more long-term health conditions, is critical to increasing their inclusion in maternity research. Giant PANDA is a randomised controlled trial, evaluating the effect of a treatment initiation strategy with nifedipine versus labetalol on severe maternal hypertension and a composite outcome of fetal/neonatal death, or neonatal unit admission. We aimed to undertake a mixed methods study-within-a-project within the Giant PANDA trial to understand barriers and facilitators to participation, understand and optimise current representativeness of clinical trial delivery of those with multiple long-term conditions and co-create a checklist to support their inclusion in pregnancy research. Methods: We undertook online workshops with women with lived experience and hybrid workshops with healthcare professionals who look after women with multiple long-term conditions. A site audit of Giant PANDA sites provided insights into research delivery capacity and health system set-up, and how this influences inclusion. An extension to the Giant PANDA screening log captured data on multiple long-term conditions enabling analysis of the impact of these health conditions on women’s inclusion in the trial. We co-created a checklist of recommendations for those designing and recruiting to similar clinical trials. Results: Five key recommendations were identified including a need to (1) involve women with multiple long-term conditions as partners in maternity research and (2) minimise barriers that stop them from taking part through (3) designing and delivering research that is flexible in time and place (4) consider research as part of care for everyone, including those with multiple long-term conditions and (5) measure and report inclusion of those with two or more health conditions in maternity research. Multiple long-term conditions were not a barrier to recruitment or randomisation in the Giant PANDA trial. Conclusion: Women with multiple long-term conditions would like opportunities to find out about and participate in research which accounts for their needs. Our checklist aims to support those designing and delivering maternity research to optimise inclusion of individuals with multiple-long term conditions. Trial registration: Giant PANDA: EudraCT number: 2020-003410-12, ISRCTN: 12,792,616

    Improvements to the APBS biomolecular solvation software suite

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    The Adaptive Poisson-Boltzmann Solver (APBS) software was developed to solve the equations of continuum electrostatics for large biomolecular assemblages that has provided impact in the study of a broad range of chemical, biological, and biomedical applications. APBS addresses three key technology challenges for understanding solvation and electrostatics in biomedical applications: accurate and efficient models for biomolecular solvation and electrostatics, robust and scalable software for applying those theories to biomolecular systems, and mechanisms for sharing and analyzing biomolecular electrostatics data in the scientific community. To address new research applications and advancing computational capabilities, we have continually updated APBS and its suite of accompanying software since its release in 2001. In this manuscript, we discuss the models and capabilities that have recently been implemented within the APBS software package including: a Poisson-Boltzmann analytical and a semi-analytical solver, an optimized boundary element solver, a geometry-based geometric flow solvation model, a graph theory based algorithm for determining pKaK_a values, and an improved web-based visualization tool for viewing electrostatics

    Society for endocrinology guideline for understanding, diagnosing and treating female hypogonadism

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    Female hypogonadism (FH) is a relatively common endocrine disorder in women of premenopausal age, but there are significant uncertainties and wide variation in its management. Most current guidelines are monospecialty and only address premature ovarian insufficiency (POI); some allude to management in very brief and general terms, and most rely upon the extrapolation of evidence from the studies relating to physiological estrogen deficiency in postmenopausal women. The Society for Endocrinology commissioned new guidance to provide all care providers with a multidisciplinary perspective on managing patients with all forms of FH. It has been compiled using expertise from Endocrinology, Primary Care, Gynaecology and Reproductive Health practices, with contributions from expert patients and a patient support group, to help clinicians best manage FH resulting from both POI and hypothalamo‐pituitary disorders, whether organic or functional

    Rehabilitation aimed at improving outdoor mobility for people after stroke: a multicentre randomised controlled study (the Getting out of the House Study)

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    Background: One-third of stroke patients are dependent on others to get outside their homes. This can cause people to become housebound, leading to increased immobility, poor health, isolation and misery. There is some evidence that outdoor mobility rehabilitation can reduce these limitations. Objective: To test the clinical effectiveness and cost-effectiveness of an outdoor mobility rehabilitation intervention for stroke patients. Design: Multicentre, parallel-group randomised controlled trial, with two groups allocated at a 1 : 1 ratio plus qualitative participant interviews. Setting: Fifteen UK NHS stroke services throughout England, Scotland and Wales. Participants: A total of 568 stroke patients who wished to get out of the house more often, mean age of 71 years: 508 reached the 6-month follow-up and 10 were interviewed. Intervention: Control was delivered prior to randomisation to all participants, and consisted of verbal advice and transport and outdoor mobility leaflets. Intervention was a targeted outdoor mobility rehabilitation programme delivered by 29 NHS therapists to 287 randomly chosen participants for up to 12 sessions over 4 months. Main outcome measures: Primary outcome was participant health-related quality of life, measured by the Short Form questionnaire-36 items, version 2 (Social Function domain), 6 months after baseline. Secondary outcomes were functional ability, mobility, number of journeys (from monthly travel diaries), satisfaction with outdoor mobility (SWOM), psychological well-being and resource use [health care and Personal Social Services (PSS)] 6 months after baseline. Carer well-being was recorded. All outcome measures were collected by post and repeated 12 months after baseline. Outcomes for the groups were compared using statistical significance testing and adjusted for multiple membership to account for the effect of multiple therapists at different sites. Interviews were analysed using interpretive phenomenology to explore confidence. Results: A median of seven intervention sessions [interquartile range (IQR) 3–7 sessions], median duration of 369 minutes (IQR 170–691.5 minutes) per participant was delivered. There was no significant difference between the groups on health-related quality of life (social function). There were no significant differences between groups in functional ability, psychological well-being or SWOM at 6- or 12-month follow-ups. There was a significant difference observed for travel journeys with the intervention group being 42% more likely to make a journey compared with the control group [rate ratio 1.42, 95% confidence interval (95% CI) 1.14 to 1.67] at 6 months and 76% more likely (rate ratio 1.76, 95% CI 1.36 to 1.95) at 12 months. The number of journeys was affected by the therapist effect. The mean incremental cost (total NHS and PSS cost) of the intervention was £3413.75 (95% CI –£448.43 to £7121.00), with an incremental quality-adjusted life-year gain of –0.027 (95% CI –0.060 to 0.007) according to the European Quality of Life-5 Dimensions and –0.003 (95% CI –0.016 to 0.006) according to the Short Form questionnaire-6 Dimensions. At baseline, 259 out of 281 (92.2%) participants in the control group were dissatisfied with outdoor mobility but at the 6-month assessment this had reduced to 77.7% (181/233), a 15% reduction. The corresponding reduction in the intervention group was slightly greater (21%) than 268 out of 287 (93.4%) participants dissatisfied with outdoor mobility at baseline to 189 out of 261 (72.4%) at 6 months. Participants described losing confidence after stroke as being detrimental to outdoor mobility. Recruitment and retention rates were high. The intervention was deliverable by the NHS but had a neutral effect in all areas apart from potentially increasing the number of journeys. This was dependent on the therapist effect, meaning that some therapists were more successful than others. The control appeared to affect change. Conclusions: The outdoor mobility intervention provided in this study to these stroke patients was not clinically effective or cost-effective. However, the provision of personalised information and monthly diaries should be considered for all people who wish to get out more

    C-STICH2: emergency cervical cerclage to prevent miscarriage and preterm birth—study protocol for a randomised controlled trial

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    Abstract Background Cervical cerclage is a recognised treatment to prevent late miscarriage and pre-term birth (PTB). Emergency cervical cerclage (ECC) for cervical dilatation with exposed unruptured membranes is less common and the potential benefits of cerclage are less certain. A randomised control trial is needed to accurately assess the effectiveness of ECC in preventing pregnancy loss compared to an expectant approach. Methods C-STICH2 is a multicentre randomised controlled trial in which women presenting with cervical dilatation and unruptured exposed membranes at 16 + 0 to 27 + 6 weeks gestation are randomised to ECC or expectant management. Trial design includes 18 month internal pilot with embedded qualitative process evaluation, minimal data set and a within-trial health economic analysis. Inclusion criteria are ≥16 years, singleton pregnancy, exposed membranes at the external os, gestation 16 + 0–27 + 6 weeks, and informed consent. Exclusion criteria are contraindication to cerclage, cerclage in situ or previous cerclage in this pregnancy. Randomisation occurs via an online service in a 1:1 ratio, using a minimisation algorithm to reduce chance imbalances in key prognostic variables (site, gestation and dilatation). Primary outcome is pregnancy loss; a composite including miscarriage, termination of pregnancy and perinatal mortality defined as stillbirth and neonatal death in the first week of life. Secondary outcomes include all core outcomes for PTB. Two-year development outcomes will be assessed using general health and Parent Report of Children’s Abilities-Revised (PARCA-R) questionnaires. Intended sample size is 260 participants (130 each arm) based on 60% rate of pregnancy loss in the expectant management arm and 40% in the ECC arm, with 90% power and alpha 0.05. Analysis will be by intention-to-treat. Discussion To date there has been one small trial of ECC in 23 participants which included twin and singleton pregnancies. This small trial along with the largest observational study (n = 161) found ECC to prolong pregnancy duration and reduce deliveries before 34 weeks gestation. It is important to generate high quality evidence on the effectiveness of ECC in preventing pregnancy loss, and improve understanding of the prevalence of the condition and frequency of complications associated with ECC. An adequately powered RCT will provide the highest quality evidence regarding optimum care for these women and their babies. Trial registration ISRCTN Registry ISRCTN12981869 . Registered on 13th June 2018

    Post-Fasciotomy Classification System for Acute Compartment Syndrome of the Leg

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    Objective: Acute compartment syndrome (ACS) is a true emergency. Even with urgent fasciotomy there is often muscle damage and need for further surgery. Although ACS is not uncommon, no validated classification system exists to aid in efficient and clear communication. The aim of this study was to establish and validate a classification system for the consequences of ACS treated with fasciotomy. Methods: Using a modified Delphi method, an international panel of ACS experts was assembled to both establish a grading scheme for the disease and then validate the classification system. The goal was to articulate discrete grades of ACS related to fasciotomy findings and associated costs. A pilot analysis was used to determine questions that were clear to the respondents. Discussion of this analysis resulted in another round of cases used for 24 other raters. The twenty-four individuals implemented the classification system two separate times to compare outcomes for 32 clinical cases. The accuracy and reproducibility of the classification system were subsequently calculated based on the providers' responses. Results: The Fleiss’ Kappa of all raters was at 0.711 showing a strong agreement between the 24 raters. Secondary validation was performed for paired 276 raters and correlation was tested using the Kendall coefficient. The median correlation coefficient was 0.855. All 276 pairs had statistically significant correlation. Correlation coefficient between the first and second rating sessions was strong with the median pair scoring at 0.867. All surgeons had statistically significant internal consistency. Conclusion: This new ACS classification system may be applied to better understand the impact of ACS on patient outcomes and economic costs for leg ACS. Level of Evidence: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved

    On the interpretation of in situ HONO observations via photochemical steady state

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    A substantial body of recent literature has shown that boundary layer HONO levels are higher than can be explained by simple, established gas-phase chemistry, to an extent that implies that additional HONO sources represent a major, or the dominant, precursor to OH radicals in such environments. This conclusion may be reached by analysis of point observations of (for example) OH, NO and HONO, alongside photochemical parameters; however both NO and HONO have non-negligible atmospheric lifetimes, so these approaches may be problematic if substantial spatial heterogeneity exists. We report a new dataset of HONO, NOx and HOx observations recorded at an urban background location, which support the existence of additional HONO sources as determined elsewhere. We qualitatively evaluate the possible impacts of local heterogeneity using a series of idealised numerical model simulations, building upon the work of Lee et al. (J. Geophys. Res., 2013, DOI: 10.1002/2013JD020341). The simulations illustrate the time required for photostationary state approaches to yield accurate results following substantial perturbations in the HOx/NOx/NOy chemistry, and the scope for bias to an inferred HONO source from NOx and VOC emissions in either a positive or negative sense, depending upon the air mass age following emission. To assess the extent to which these impacts may be present in actual measurements, we present exploratory spatially resolved measurements of HONO and NOx abundance obtained using a mobile instrumented laboratory. Measurements of the spatial variability of HONO in urban, suburban and rural environments show pronounced changes in abundance are found in proximity to major roads within urban areas, indicating that photo-stationary steady state (PSS) analyses in such areas are likely to be problematic. The measurements also show areas of very homogeneous HONO and NOx abundance in rural, and some suburban, regions, where the PSS approach is likely to be valid. Implications for future exploration of HONO production mechanisms are discussed

    Discovery of species-wide tool use in the Hawaiian crow

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    Funding from the Biotechnology and Biological Sciences Research Council, UK (BBSRC; grant BB/G023913/2 to C.R., and studentship to B.C.K.), the University of St Andrews (C.R.), JASSO (S.S.), and the Royal Society of London (M.B.M.). Funding for thecaptive ‘Alala propagation programme was provided by the U.S. Fish and Wildlife Service, Hawai‘i Division of Forestry and Wildlife, Moore Family Foundation, Marisla Foundation, several anonymous donors, and San Diego Zoo Global.Only a handful of bird species are known to use foraging tools in the wild1. Amongst them, the New Caledonian crow (Corvus moneduloides) stands out with its sophisticated tool-making skills2, 3. Despite considerable speculation, the evolutionary origins of this species’ remarkable tool behaviour remain largely unknown, not least because no naturally tool-using congeners have yet been identified that would enable informative comparisons4. Here we show that another tropical corvid, the ‘Alalā (C. hawaiiensis; Hawaiian crow), is a highly dexterous tool user. Although the ‘Alalā became extinct in the wild in the early 2000s, and currently survives only in captivity5, at least two lines of evidence suggest that tool use is part of the species’ natural behavioural repertoire: juveniles develop functional tool use without training, or social input from adults; and proficient tool use is a species-wide capacity. ‘Alalā and New Caledonian crows evolved in similar environments on remote tropical islands, yet are only distantly related6, suggesting that their technical abilities arose convergently. This supports the idea that avian foraging tool use is facilitated by ecological conditions typical of islands, such as reduced competition for embedded prey and low predation risk4, 7. Our discovery creates exciting opportunities for comparative research on multiple tool-using and non-tool-using corvid species. Such work will in turn pave the way for replicated cross-taxonomic comparisons with the primate lineage, enabling valuable insights into the evolutionary origins of tool-using behaviour.PostprintPeer reviewe
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