97 research outputs found

    Evaluating the performance of hydrological models via cross-spectral analysis: case study of the Thames Basin, United Kingdom

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    Nine distributed hydrological models, forced with common meteorological inputs, simulated naturalised daily discharge from the Thames Basin for 1963-2001. While model-dependent evaporative losses are critical for modelling mean discharge, multiple physical processes at many time scales influence the variability and timing of discharge. Here we advocate the use of cross-spectral analysis to measure how the average amplitude, and independently the average phase, of modelled discharge differ from observed discharge at daily to decadal time scales. Simulation of the spectral properties of the model discharge via numerical manipulation of precipitation confirms that modelled transformation involves runoff generation and routing that amplify the annual cycle, while subsurface storage and routing of runoff between grid boxes introduces most autocorrelation and delays. Too much or too little modelled evaporation affects discharge variability as do the capacity and time constants of modelled stores. Additionally the performance of specific models would improve if four issues were tackled: a) non-sinusoidal annual variations in model discharge (prolonged low baseflow and shortened high baseflow, 3 models), b) excessive attenuation of high frequency variability (3 models), c) excessive short-term variability in winter half years but too little variability in summer half years (2 models) and d) introduction of phase delays at the annual scale only during runoff generation (3 models) or only during routing (1 model). Cross-spectral analysis reveals how re-runs of one model using alternative methods of runoff generation - designed to improve performance at the weekly to monthly time scales - degraded performance at the annual scale. The cross-spectral approach facilitates hydrological model diagnoses and development

    Collective Body Mapping Ritual

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    This paper introduces and describes a collective body mapping ritual presented as part of the Goldsmiths International Art Therapy Conference. The following reflections on the unfolding of the ritual were distilled from a series of conversations between Christina, Annette, Sue and Penny that took place immediately after the conference, and in the ensuing weeks and months. The article has been co-written by all four – a process that echoed the collective sharing and making of meaning that took place among participants in the ritual circle

    Data Assimilation Enhancements to Air Force Weathers Land Information System

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    The United States Air Force (USAF) has a proud and storied tradition of enabling significant advancements in the area of characterizing and modeling land state information. 557th Weather Wing (557 WW; DoDs Executive Agent for Land Information) provides routine geospatial intelligence information to warfighters, planners, and decision makers at all echelons and services of the U.S. military, government and intelligence community. 557 WW and its predecessors have been home to the DoDs only operational regional and global land data analysis systems since January 1958. As a trusted partner since 2005, Air Force Weather (AFW) has relied on the Hydrological Sciences Laboratory at NASA/GSFC to lead the interagency scientific collaboration known as the Land Information System (LIS). LIS is an advanced software framework for high performance land surface modeling and data assimilation of geospatial intelligence (GEOINT) information

    Mapping of a blood pressure QTL on chromosome 17 in American Indians of the strong heart family study

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    Abstract Background Blood pressure (BP) is a complex trait, with a heritability of 30 to 40%. Several genome wide associated BP loci explain only a small fraction of the phenotypic variation. Family studies can provide an important tool for gene discovery by utilizing trait and genetic transmission information among relative-pairs. We have previously described a quantitative trait locus at chromosome 17q25.3 influencing systolic BP in American Indians of the Strong Heart Family Study (SHFS). This locus has been reported to associate with variation in BP traits in family studies of Europeans, African Americans and Hispanics. Methods To follow-up persuasive linkage findings at this locus, we performed comprehensive genotyping in the 1-LOD unit support interval region surrounding this QTL using a multi-step strategy. We first genotyped 1,334 single nucleotide polymorphisms (SNPs) in 928 individuals from families that showed evidence of linkage for BP. We then genotyped a second panel of 306 SNPs in all SHFS participants (N = 3,807) for genes that displayed the strongest evidence of association in the region, and, in a third step, included additional genotyping to better cover the genes of interest and to interrogate plausible candidate genes in the region. Results Three genes had multiple SNPs marginally associated with systolic BP (TBC1D16, HRNBP3 and AZI1). In BQTN analysis, used to estimate the posterior probability that any variant in each gene had an effect on the phenotype, AZI1 showed the most prominent findings (posterior probability of 0.66). Importantly, upon correction for multiple testing, none of our study findings could be distinguished from chance. Conclusion Our findings demonstrate the difficulty of follow-up studies of linkage studies for complex traits, particularly in the context of low powered studies and rare variants underlying linkage peaks

    Understanding implementability in clinical trials : a pragmatic review and concept map

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    Background The translation of evidence from clinical trials into practice is complex. One approach to facilitating this translation is to consider the 'implementability' of trials as they are designed and conducted. Implementability of trials refers to characteristics of the design, execution and reporting of a late-phase clinical trial that can influence the capacity for the evidence generated by that trial to be implemented. On behalf of the Australian Clinical Trials Alliance (ACTA), the national peak body representing networks of clinician researchers conducting investigator-initiated clinical trials, we conducted a pragmatic literature review to develop a concept map of implementability. Methods Documents were included in the review if they related to the design, conduct and reporting of late-phase clinical trials; described factors that increased or decreased the capacity of trials to be implemented; and were published after 2009 in English. Eligible documents included systematic reviews, guidance documents, tools or primary studies (if other designs were not available). With an expert reference group, we developed a preliminary concept map and conducted a snowballing search based on known relevant papers and websites of key organisations in May 2019. Results Sixty-five resources were included. A final map of 38 concepts was developed covering the domains of validity, relevance and usability across the design, conduct and reporting of a trial. The concepts drew on literature relating to implementation science, consumer engagement, pragmatic trials, reporting, research waste and other fields. No single resource addressed more than ten of the 38 concepts in the map. Conclusions The concept map provides trialists with a tool to think through a range of areas in which practical action could enhance the implementability of their trials. Future work could validate the strength of the associations between the concepts identified and implementability of trials and investigate the effectiveness of steps to address each concept. ACTA will use this concept map to develop guidance for trialists in Australia

    Developing an Australian Melanoma Clinical Outcomes Registry (MelCOR): a protocol paper

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    Introduction Australia has the highest incidence of melanoma in the world with variable care provided by a diverse range of clinicians. Clinical quality registries aim to identify these variations in care and provide anonymised, benchmarked feedback to clinicians and institutions to improve patient outcomes. The Australian Melanoma Clinical Outcomes Registry (MelCOR) aims to collect population-wide, clinical-level data for the early management of cutaneous melanoma and provide anonymised feedback to healthcare providers. Methods and analysis A modified Delphi process will be undertaken to identify key clinical quality indicators for inclusion in the MelCOR pilot. MelCOR will prospectively collect data relevant to these quality indicators, initially for all people over the age of 18 years living in Victoria and Queensland with a melanoma diagnosis confirmed by histopathology, via a two-stage recruitment and consent process. In stage 1, existing State-based cancer registries contact the treating clinician and provide an opportunity for them to opt themselves or their patients out of direct contact with MelCOR. After stage 1, re-identifiable clinical data are provided to the MelCOR under a waiver of consent. In stage 2, the State-based cancer registry will approach the patient directly and invite them to opt in to MelCOR and share identifiable data. If a patient elects to opt in, MelCOR will be able to contact patients directly to collect patient-reported outcome measures. Aggregated data will be used to provide benchmarked, comparative feedback to participating institutions/clinicians. Ethics and dissemination Following the successful collection of pilot data, the feasibility of an Australia-wide roll out will be evaluated. Key quality indicator data will be the core of the MelCOR dataset, with additional data points added later. Annual reports will be issued, first to the relevant stakeholders followed by the public. MelCOR is approved by the Alfred Ethics Committee (58280/127/20)

    Implementation of increased physical therapy intensity for improving walking after stroke: Walk 'n Watch protocol for a multi-site stepped-wedge cluster randomized controlled trial

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    Clinical practice guidelines support structured, progressive protocols for improving walking after stroke. Yet, practice is slow to change, evidenced by the little amount of walking activity in stroke rehabilitation units. Our recent study (n=75) found that a structured, progressive protocol integrated with typical daily physical therapy improved walking and quality of life measures over usual care. Research therapists progressed the intensity of exercise by using heart rate and step counters worn by the participants with stroke during therapy. To have the greatest impact, our next step is to undertake an implementation trial to change practice across stroke units where we enable the entire unit to use the protocol as part of standard of care. What is the effect of introducing structured, progressive exercise (termed the Walk 'n Watch protocol) to standard of care on the primary outcome of walking in adult participants with stroke over the hospital inpatient rehabilitation period? Secondary outcomes will be evaluated and include quality of life.Methods and sample size estimates: This national, multisite clinical trial will randomize 12 sites using a stepped-wedge design where each site will be randomized to deliver Usual Care initially for 4, 8, 12 or 16-months (three sites for each duration). Then, each site will switch to the Walk 'n Watch phase for the remaining duration of a total 20-month enrolment period. Each participant will be exposed to only one of Usual Care or Walk 'n Watch. The trial will enrol a total of 195 participants with stroke to achieve a power of 80% with a Type I error rate of 5%, allowing for 20% dropout. Participants will be medically stable adults post-stroke and able to take 5 steps with a maximum physical assistance from one therapist. The Walk 'n Watch protocol focuses on completing a minimum of 30-minutes of weight-bearing, walking-related activities (at the physical therapists' discretion) that progressively increases in intensity informed by activity trackers measuring heart rate and step number.Study outcome(s): The primary outcome will be the change in walking endurance, measured by the Six-Minute Walk Test, from Baseline (T1) to 4-weeks (T2). This change will be compared across Usual Care and Walk 'n Watch phases using a linear mixed-effects model. Additional physical, cognitive, and quality of life outcomes will be measured at T1, T2, and 12-months post-stroke (T3) by a blinded assessor. The implementation stepped-wedge cluster-randomized trial enables the protocol to be tested under real-world conditions, involving all clinicians on the unit. It will result in all sites and all clinicians on the unit to gain expertise in protocol delivery. Hence, a deliberate outcome of the trial is facilitating changes in best practice to improve outcomes for participants with stroke in the trial, and for the many participants with stroke admitted after the trial ends
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