A radar antenna intercepts thermal radiation from various sources, including the ground, the sun, the sky, precipitation, and man-made radiators. In the radar receiver, this external radiation ...produces noise that constructively adds to the receiver internal noise and results in the overall system noise. Consequently, the system noise power is dependent on the antenna position and needs to be estimated accurately. Inaccurate noise power measurements may lead to a reduction of coverage if the noise power is overestimated or to radar data images cluttered by noise speckles if the noise power is underestimated. Moreover, when an erroneous noise power is used at low to moderate signal-to-noise ratios, estimators can produce biased meteorological variables. Therefore, to obtain the best quality of radar products, it is desirable to compute meteorological variables using the noise power measured at each antenna position. An effective technique that achieves this by estimating the noise power in real time from measured powers at each scan direction and in parallel with weather data collection has been proposed. Herein, the effects of such radial-based noise power estimation on spectral moment estimates are investigated.
Determinants of practice are factors that might prevent or enable improvements. Several checklists, frameworks, taxonomies, and classifications of determinants of healthcare professional practice ...have been published. In this paper, we describe the development of a comprehensive, integrated checklist of determinants of practice (the TICD checklist).
We performed a systematic review of frameworks of determinants of practice followed by a consensus process. We searched electronic databases and screened the reference lists of key background documents. Two authors independently assessed titles and abstracts, and potentially relevant full text articles. We compiled a list of attributes that a checklist should have: comprehensiveness, relevance, applicability, simplicity, logic, clarity, usability, suitability, and usefulness. We assessed included articles using these criteria and collected information about the theory, model, or logic underlying how the factors (determinants) were selected, described, and grouped, the strengths and weaknesses of the checklist, and the determinants and the domains in each checklist. We drafted a preliminary checklist based on an aggregated list of determinants from the included checklists, and finalized the checklist by a consensus process among implementation researchers.
We screened 5,778 titles and abstracts and retrieved 87 potentially relevant papers in full text. Several of these papers had references to papers that we also retrieved in full text. We also checked potentially relevant papers we had on file that were not retrieved by the searches. We included 12 checklists. None of these were completely comprehensive when compared to the aggregated list of determinants and domains. We developed a checklist with 57 potential determinants of practice grouped in seven domains: guideline factors, individual health professional factors, patient factors, professional interactions, incentives and resources, capacity for organisational change, and social, political, and legal factors. We also developed five worksheets to facilitate the use of the checklist.
Based on a systematic review and a consensus process we developed a checklist that aims to be comprehensive and to build on the strengths of each of the 12 included checklists. The checklist is accompanied with five worksheets to facilitate its use in implementation research and quality improvement projects.
The tailoring of implementation interventions includes the identification of the determinants of, or barriers to, healthcare practice. Different methods for identifying determinants have been used in ...implementation projects, but which methods are most appropriate to use is unknown.
The study was undertaken in five European countries, recommendations for a different chronic condition being addressed in each country: Germany (polypharmacy in multimorbid patients); the Netherlands (cardiovascular risk management); Norway (depression in the elderly); Poland (chronic obstructive pulmonary disease--COPD); and the United Kingdom (UK) (obesity). Using samples of professionals and patients in each country, three methods were compared directly: brainstorming amongst health professionals, interviews of health professionals, and interviews of patients. The additional value of discussion structured through reference to a checklist of determinants in addition to brainstorming, and determinants identified by open questions in a questionnaire survey, were investigated separately. The questionnaire, which included closed questions derived from a checklist of determinants, was administered to samples of health professionals in each country. Determinants were classified according to whether it was likely that they would inform the design of an implementation intervention (defined as plausibly important determinants).
A total of 601 determinants judged to be plausibly important were identified. An additional 609 determinants were judged to be unlikely to inform an implementation intervention, and were classified as not plausibly important. Brainstorming identified 194 of the plausibly important determinants, health professional interviews 152, patient interviews 63, and open questions 48. Structured group discussion identified 144 plausibly important determinants in addition to those already identified by brainstorming.
Systematic methods can lead to the identification of large numbers of determinants. Tailoring will usually include a process to decide, from all the determinants that are identified, those to be addressed by implementation interventions. There is no best buy of methods to identify determinants, and a combination should be used, depending on the topic and setting. Brainstorming is a simple, low cost method that could be relevant to many tailored implementation projects.
In the UK around 22% of men and 24% of women are obese, and there are varying but worrying levels in other European countries. Obesity is a chronic condition that carries an important health risk. ...National guidelines, for use in England, on the management of people who are overweight or obese have been published by the National Institute for Health and Clinical Excellence (NICE, 2006). NICE recommendations for primary care teams are: determine the degree of overweight and obesity; assess lifestyle, comorbidities and willingness to change; offer multicomponent management of overweight and obesity; referral to external services when appropriate. This study investigates a tailored intervention to improve the implementation of these recommendations by primary care teams.
The study is a cluster randomised controlled trial. Primary care teams will be recruited from the East Midlands of England, and randomised into two study arms: 1) the study group, in which primary care teams are offered a set of tailored interventions to help implement the NICE guidelines for overweight and obesity; or 2) the control group in which primary care teams continue to practice usual care. The primary outcome is the proportion of overweight or obese patients for whom the primary care team adheres to the NICE guidelines. Secondary outcomes include the proportion of patients with a record of lifestyle assessment, referral to external weight loss services, the proportion of obese patients who lose weight during the intervention period, and the mean weight change over the same period.
Although often recommended, the methods of tailoring implementation interventions to account for the determinants of practice are not well developed. This study is part of a programme of studies seeking to develop the methods of tailored implementation.
Current Controlled Trials ISRCTN07457585. Registered 09/08/2013. Randomisation commenced 30/08/2013.
In the 'Tailored Implementation for Chronic Diseases (TICD)' project, five tailored implementation programs to improve healthcare delivery in different chronic conditions have been developed. These ...programs will be evaluated in distinct cluster-randomized controlled trials. This protocol describes the process evaluation across these trials, which aims to identify determinants of change in chronic illness care, to examine the validity of the tailoring methods that were applied, and to analyze the association of implementation activities and the effectiveness of the program.
A multilevel approach was used to develop five tailored implementation interventions. In order to guide the process evaluation in five distinct trials, the study protocols for the cluster randomized trials and the related process evaluations were developed simultaneously and iteratively.
The process evaluation comprises three main components: a structured survey with health professionals in the trials, semi-structured interviews with a purposeful sample of this study population, and standardized documentation of organizational practice characteristics. Norway will only conduct the qualitative part of the analysis because the survey and documentation of practice characteristics are considered to be not feasible. The evaluation is guided by 'logic models' of the implementation programs: frameworks that specify the linkages between the strategies used, the determinants addressed by tailoring, and the anticipated outcomes. Standardization of measures across trials is sought to facilitate analysis of aggregated data from the trials.
This process evaluation will need to find a balance between standardization of methods across trials and the tailoring of measures to the specificities of each trial.
Short term food choices can affect not only hunger, but can also affect mood and cognitive function, yet few studies have measured all three factors in a single study. The macronutrient composition ...of breakfast and diet influences mood, appetite and cognitive function. This thesis describes a series of studies in healthy female subjects investigating the effects of breakfast, and manipulations of breakfast and diet composition on mood, appetite and cognitive function. In these studies subjects were provided with high fat, low carbohydrate (HFLC) and low fat, high carbohydrate (LFHC) breakfasts and diets. Study 1 found that breakfast provision (LFHC breakfast), in comparison to breakfast omission resulted in significant improvements in subjects' self reported ratings of mood and appetite, which were closely correlated with each other. Breakfast provision did not cause any significant changes in cognitive function, but this may be as a result of insufficiently demanding tests. The macronutrient composition of the breakfasts was modified in study 2 which found that the HFLC breakfast reduced subjective feelings of anger, reduced target reaction times and prevented a deterioration in the letter x accuracy task in comparison the LFHC breakfast. The HFLC and LFHC breakfast differed from subjects habitual breakfast composition. Study 3 and study 4 found that habitual breakfast consumption (in comparison to the HFLC and LFHC breakfasts) resulted in a much greater increase (relative to baseline) in subjective ratings of energy and placidity, a greater reduction in ratings of tiredness and a reduction in reaction times. Study 4 also found that consumption of a HFLC diet for 2 weeks resulted in an increase in subjective ratings of energy, whilst consumption of a LFHC diet resulted in a reduction. Consumption of both diets resulted in a reduction in ratings of tense and an increase in ratings of placidity at the second study visits.
An ageing population and high levels of multimorbidity increase rates of GP and specialist consultations. Constraints on health care funding are leading to additional pressure for the adoption of ...safe and cost-effective alternatives to specialist care, in some cases by shifting services to primary care.
In this paper we argue, having searched for evidence on approaches to shifting care for some people with cardiovascular problems from secondary to primary care, that a collaborative, multidisciplinary approach is required to achieve high quality outcomes from cardiovascular care in the primary care setting. Simply transferring patients from specialist care to management by primary care teams is likely to lead to worse outcomes than services that involve both specialists and primary care teams together, in planned and effectively managed systems of care.The care of patients with certain chronic conditions in the community, if appropriately organised, can achieve the same health outcomes as ambulatory care by hospital specialists. However, shared care by GPs and specialists for patients with chronic heart failure after discharge from hospital can deliver better patient survival. The existing models of shared care include specialists working in an ambulatory care setting (in Central and Eastern Europe) or in hospital based outreach clinics, and cardiology care organised by GPs in the UK and Australia, which have demonstrated reductions in referral rates.
Current research supports the idea of the management of certain chronic health conditions in primary care based on the integration of GPs and specialists into multidisciplinary teams, based on availability of reliable evidence about cost-effectiveness, health care outcomes, patient preference and incentives for GPs. Evaluation of such schemes is mandatory, however, to ensure that the expected benefits do materialise.
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