1,448 research outputs found
Weed control strategies in organically grown carrots
This paper outlines a study to integrate elements of cultural, thermal and mechanical control methods in the production of late maincrop drilled organic carrots. Agronomic and economic findings are discusse
Horticultural weed control in organic systems ā a modelling approach
This report was presented at the UK Organic Research 2002 Conference. Weed control is an important yet mainly unaddressed research issue in organic systems. At present there is little agronomic support to underpin weed management decisions. Computer modelling and simulation techniques may provide a valuable tool for understanding the nature and processes of the organic system thus generating knowledge and information of direct benefit to growers, which will aid in short and long term weed management strategies
Fertility building strategies during the conversion period ā assessment of performance in a stockless field vegetable rotation
This report was presented at the UK Organic Research 2002 Conference of the Colloquium of Organic Researchers (COR). Nutrient off-takes, residue returns and nutrient inputs were measured during and after conversion from a conventional arable system to organic vegetables with cereals. This data was used to construct nutrient budgets to assess the effectiveness of contrasting fertility building strategies and various cropping regimes. The effect of placing the cereal crops in different places in the crop sequence was also considered
A modified route to unsymmetrically substituted triphenylenes, new functionalised derivatives and twins, and the smallest reported triphenylene mesogen
We report the unexpected observation of columnar mesophase formation in a simple 2,7-dibromotetramethoxytriphenylene ā by far the most lightly substituted discotic mesogen in this class. This derivative was prepared alongside the 3,6-dibromotriphenylene isomer to demonstrate an alternative, modified synthetic strategy that permits late-stage interchange of alkyl chain substituents. The new method is employed alongside the original route to deliver several new materials, including a conjugated ferrocene-triphenylene-ferrocene triad, a BODIPY-triphenylene-BODIPY triad and a new nematic twin linked through imine bridges
MultiBUGS: A Parallel Implementation of the BUGS Modeling Framework for Faster Bayesian Inference
MultiBUGS is a new version of the general-purpose Bayesian modeling software BUGS that implements a generic algorithm for parallelizing Markov chain Monte Carlo (MCMC) algorithms to speed up posterior inference of Bayesian models. The algorithm parallelizes evaluation of the product-form likelihoods formed when a parameter has many children in the directed acyclic graph (DAG) representation; and parallelizes sampling of conditionally-independent sets of parameters. A heuristic algorithm is used to decide which approach to use for each parameter and to apportion computation across computational cores. This enables MultiBUGS to automatically parallelize the broad range of statistical models that can be fitted using BUGS-language software, making the dramatic speed-ups of modern multi-core computing accessible to applied statisticians, without requiring any experience of parallel programming. We demonstrate the use of MultiBUGS on simulated data designed to mimic a hierarchical e-health linked-data study of methadone prescriptions including 425,112 observations and 20,426 random effects. Posterior inference for the e-health model takes several hours in existing software, but MultiBUGS can perform inference in only 28 minutes using 48 computational cores
Bias modelling in evidence synthesis
Policy decisions often require synthesis of evidence from multiple sources, and the source studies typically vary in rigour and in relevance to the target question. We present simple methods of allowing for differences in rigour (or lack of internal bias) and relevance (or lack of external bias) in evidence synthesis. The methods are developed in the context of reanalysing a UK National Institute for Clinical Excellence technology appraisal in antenatal care, which includes eight comparative studies. Many were historically controlled, only one was a randomized trial and doses, populations and outcomes varied between studies and differed from the target UK setting. Using elicited opinion, we construct prior distributions to represent the biases in each study and perform a bias-adjusted meta-analysis. Adjustment had the effect of shifting the combined estimate away from the null by approximately 10%, and the variance of the combined estimate was almost tripled. Our generic bias modelling approach allows decisions to be based on all available evidence, with less rigorous or less relevant studies downweighted by using computationally simple methods
Treatment in the STAMPEDE era for castrate resistant prostate cancer in the UK: ongoing challenges and underappreciated clinical problems.
This study aimed to explore the opinions of healthcare professionals regarding the management of men with advanced prostate cancer with particular emphasis on treatment timing and sequencing; treatment adverse-effects and exercise a supportive therapy. Semi-structured interviews with a purposively selected group of healthcare professionals involved in prostate cancer care within the NHS, conducted over the phone or face to face. A total of 37 healthcare professionals participated in the interviews including urologists, clinical oncologists, medical oncologists, clinical nurse specialists, general practitioners, physiotherapists, exercise specialists, service managers, clinical commissioners and primary care physicians. The availability of newer treatments for advanced prostate cancer as well as results from the STAMPEDE and CHAARTED trials has resulted in new challenges for patients and HCPs. This includes the impact of an increased workload on oncologists, a potential lack of clinical continuity between urology and oncology and uncertainties regarding optimal selection, timing and sequencing of chemotherapy and second-line treatment. Fitness for treatment in advanced prostate cancer populations remains a significant barrier to accessing therapies for patients with a poor performance status. Among this, muscle wastage can significantly affect performance status and consequentially compromise cancer therapy. Exercise was regarded as a potential therapy to mitigate the adverse-effects of treatment including the prevention or reduction in muscle wastage. There is a lack of data guiding clinicians in this post STAMPEDE and CHAARTED era, work is needed to reassess and optimize the prostate cancer care pathway as it evolves. Exercise should be explored as a therapeutic option to mitigate the effects of long term ADT. Further study from a wider cohort of both prostate cancer care specialists and patients will aid in establishing a highly functioning pathway with optimal individualised care. Sustained exercise TrAining for Men wIth prostate caNcer on Androgen deprivation: the STAMINA programme (RP-DG-1213-10,010). REC Reference: 15/SW/0260 IRAS Project ID: 178340 Hospital ID: STH 18391 approved on 24/08/2015
Digital methodology to implement the ECOUTER engagement process
ECOUTER (Employing COnceptUal schema for policy and TranslationĀ Engagement in Research) ā French for āto listenā ā is a new stakeholder engagementĀ method incorporating existing evidence to help participants draw upon theirĀ own knowledge of cognate issues and interact on a topic of shared concern. TheĀ results of an ECOUTER can form the basis of recommendations for research, governance,Ā practice and/or policy. This paper describes the development of a digital methodology for the ECOUTERĀ engagement process based on currently available mind mapping freeware software.Ā The implementation of an ECOUTER process tailored to applications within healthĀ studies are outlined for both online and face-to-face scenarios. Limitations of theĀ present digital methodology are discussed, highlighting theĀ requirement of a purposeĀ built software for ECOUTER research purposes
Post-discharge care following acute kidney injury: quality improvement in primary care
BACKGROUND: Over the past decade, targeting acute kidney injury (AKI) has become a priority to improve patient safety and health outcomes. Illness complicated by AKI is common and is associated with adverse outcomes including high rates of unplanned hospital readmission. Through national patient safety directives, NHS England has mandated the implementation of an AKI clinical decision support system in hospitals. In order to improve care following AKI, hospitals have also been incentivised to improve discharge summaries and general practices are recommended to establish registers of people who have had an episode of illness complicated by AKI. However, to date, there is limited evidence surrounding the development and impact of interventions following AKI. DESIGN: We conducted a quality improvement project in primary care aiming to improve the management of patients following an episode of hospital care complicated by AKI. All 31 general practices within a single NHS Clinical Commissioning Group were incentivised by a locally commissioned service to engage in audit and feedback, education training and to develop an action plan at each practice to improve management of AKI. RESULTS: AKI coding in general practice increased from 28% of cases in 2015/2016 to 50% in 2017/2018. Coding of AKI was associated with significant improvements in downstream patient management in terms of conducting a medication review within 1āmonth of hospital discharge, monitoring kidney function within 3 months and providing written information about AKI to patients. However, there was no effect on unplanned hospitalisation and mortality. CONCLUSION: The findings suggest that the quality improvement intervention successfully engaged a primary care workforce in AKI-related care, but that a higher intensity intervention is likely to be required to improve health outcomes. Development of a real-time audit tool is necessary to better understand and minimise the impact of the high mortality rate following AKI
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