Evaluating unsupervised methods to size and classify suspended particles using digital in-line holography

Substantial information can be gained from digital in-line holography of marine particles, eliminating depth-of-field and focusing errors associated with standard lens-based imagingmethods.However, for the technique to reach its full potential in oceanographic research, fully unsupervised (automated) methods are required for focusing, segmentation, sizing, and classification of particles. These computational challenges are the subject of this paper, in which the authors draw upon data collected using a variety of holographic systems developed at Plymouth University, United Kingdom, from a significant range of particle types, sizes, and shapes. A new method for noise reduction in reconstructed planes is found to be successful in aiding particle segmentation and sizing. The performance of an automated routine for deriving particle characteristics (and subsequent size distributions) is evaluated against equivalent size metrics obtained by a trained operative measuring grain axes on screen. The unsupervised method is found to be reliable, despite some errors resulting from oversegmentation of particles. A simple unsupervised particle classification system is developed and is capable of successfully differentiating sand grains, bubbles, and diatoms from within the surfzone. Avoiding miscounting bubbles and biological particles as sand grains enables more accurate estimates of sand concentrations and is especially important in deployments of particle monitoring instrumentation in aerated water. Perhaps the greatest potential for further development in the computational aspects of particle holography is in the area of unsupervised particle classification. The simple method proposed here provides a foundation upon which further development could lead to reliable identification of more complex particle populations, such as those containing phytoplankton, zooplankton, flocculated cohesive sediments, and oil droplets

Working memory and high-level cognition in children: An analysis of timing and accuracy in complex span tasks

This study examined working memory (WM) using complex span tasks (CSTs) to improve theoretical understanding of the relationship between WM and high-level cognition (HLC) in children. Ninety-two children aged between seven and eight years were tested on three computer-paced CSTs and measures of non-verbal reasoning, reading and mathematics. Processing times in the CSTs were restricted based on individually titrated processing speeds, and performance was compared to participant-led tasks with no time restrictions. Storage, processing accuracy, and both processing and recall times within the CSTs were used as performance indices to understand the effects of time restrictions at a granular level. Restricting processing times did not impair storage, challenging models that argue for a role of maintenance in WM. A task-switching account best explained the effect of time restrictions on performance indices and their inter-relationships. Principal component analysis showed that a single factor with all performance indices from just one CST (Counting span) was the best predictor of HLC. Storage in both the participant-led and computer-paced versions of this task explained unique and shared variance in HLC. However, the latter accounted for more variance in HLC when contributions from processing time were included in the model. Processing time in this condition also explained variance above and beyond storage. This suggests that faster processing is important to keep information active in WM; however, this is only evident when time restrictions are placed on the task and important when WM performance is applied in broader contexts that rely on this resource

Children’s Verbal, Visual and Spatial Processing and Storage Abilities: An Analysis of Verbal Comprehension, Reading, Counting and Mathematics

The importance of working memory (WM) in reading and mathematics performance has been widely studied, with recent research examining the components of WM (i.e., storage and processing) and their roles in these educational outcomes. However, the differing relationships between these abilities and the foundational skills involved in the development of reading and mathematics have received less attention. Additionally, the separation of verbal, visual and spatial storage and processing and subsequent links with foundational skills and downstream reading and mathematics has not been widely examined. The current study investigated the separate contributions of processing and storage from verbal, visual and spatial tasks to reading and mathematics, whilst considering influences on the underlying skills of verbal comprehension and counting, respectively. Ninety-two children aged 7- to 8-years were assessed. It was found that verbal comprehension (with some caveats) was predicted by verbal storage and reading was predicted by verbal and spatial storage. Counting was predicted by visual processing and storage, whilst mathematics was related to verbal and spatial storage. We argue that resources for tasks relying on external representations of stimuli related mainly to storage, and were largely verbal and spatial in nature. When a task required internal representation, there was a draw on visual processing and storage abilities. Findings suggest a possible meaningful separability of types of processing. Further investigation of this could lead to the development of an enhanced WM model, which might better inform interventions and reasonable adjustments for children who struggle with reading and mathematics due to WM deficits

Reducing radiation in chronic total occlusion percutaneous coronary interventions.

The field of percutaneous intervention for chronic total occlusion (CTO) has enjoyed significant innovations in the recent years. Novel techniques and technologies have revolutionized the field and have resulted in considerably higher success rates even in patients with high anatomical complexity. Successful CTO recanalization is associated with significant clinical benefits, such as the improvement of angina and quality of life, reduced rates of surgical revascularization, improvement of left ventricular function and decreased mortality rates. However, complex CTO procedures often require prolonged x-ray exposure which have been associated with adverse long term outcomes

Trends in the lifetime risk of developing cancer in Great Britain: comparison of risk for those born from 1930 to 1960

BACKGROUND: Typically, lifetime risk is calculated by the period method using current risks at different ages. Here, we estimate the probability of being diagnosed with cancer for individuals born in a given year, by estimating future risks as the cohort ages. METHODS: We estimated the lifetime risk of cancer in Britain separately for men and women born in each year from 1930 to 1960. We projected rates of all cancers (excluding non-melanoma skin cancer) and of all cancer deaths forwards using a flexible age-period-cohort model and backwards using age-specific extrapolation. The sensitivity of the estimated lifetime risk to the method of projection was explored. RESULTS: The lifetime risk of cancer increased from 38.5% for men born in 1930 to 53.5% for men born in 1960. For women it increased from 36.7 to 47.5%. Results are robust to different models for projections of cancer rates. CONCLUSIONS: The lifetime risk of cancer for people born since 1960 is >50%. Over half of people who are currently adults under the age of 65 years will be diagnosed with cancer at some point in their lifetime

A Synergistic Approach for Evaluating Climate Model Output for Ecological Applications

Increasing concern about the impacts of climate change on ecosystems is prompting ecologists and ecosystem managers to seek reliable projections of physical drivers of change. The use of global climate models in ecology is growing, although drawing ecologically meaningful conclusions can be problematic. The expertise required to access and interpret output from climate and earth system models is hampering progress in utilizing them most effectively to determine the wider implications of climate change. To address this issue, we present a joint approach between climate scientists and ecologists that explores key challenges and opportunities for progress. As an exemplar, our focus is the Southern Ocean, notable for significant change with global implications, and on sea ice, given its crucial role in this dynamic ecosystem. We combined perspectives to evaluate the representation of sea ice in global climate models. With an emphasis on ecologically-relevant criteria (sea ice extent and seasonality) we selected a subset of eight models that reliably reproduce extant sea ice distributions. While the model subset shows a similar mean change to the full ensemble in sea ice extent (approximately 50% decline in winter and 30% decline in summer), there is a marked reduction in the range. This improved the precision of projected future sea ice distributions by approximately one third, and means they are more amenable to ecological interpretation. We conclude that careful multidisciplinary evaluation of climate models, in conjunction with ongoing modeling advances, should form an integral part of utilizing model output

Acceleration of generalized hypergeometric functions through precise remainder asymptotics

We express the asymptotics of the remainders of the partial sums {s_n} of the generalized hypergeometric function q+1_F_q through an inverse power series z^n n^l \sum_k c_k/n^k, where the exponent l and the asymptotic coefficients {c_k} may be recursively computed to any desired order from the hypergeometric parameters and argument. From this we derive a new series acceleration technique that can be applied to any such function, even with complex parameters and at the branch point z=1. For moderate parameters (up to approximately ten) a C implementation at fixed precision is very effective at computing these functions; for larger parameters an implementation in higher than machine precision would be needed. Even for larger parameters, however, our C implementation is able to correctly determine whether or not it has converged; and when it converges, its estimate of its error is accurate.Comment: 36 pages, 6 figures, LaTeX2e. Fixed sign error in Eq. (2.28), added several references, added comparison to other methods, and added discussion of recursion stabilit

Walking as a meaningful leisure occupation: the implications for occupational therapy

Introduction: In response to growing interest in leisure in occupational therapy and the importance of understanding how occupations maintain, enhance and promote health and wellbeing, a qualitative phenomenological study was conducted to explore the experiences of walking for leisure. Method: Six healthy student participants, identified as regular walkers, were interviewed using a semi-structured format. Data were analysed following interpretative phenomenological analysis methodology. Findings: Participants expressed how and why walking was meaningful to them; the four main themes were social connectedness, wellbeing, connection to nature and achievement from a challenge. Findings suggest that occupational therapists could use walking and leisure occupations in intervention, and that there is scope for an occupational therapy perspective in health promotion. Conclusion: Determining the subjective meaning of engaging in walking as a leisure occupation has implications for occupational science and health promotion in helping to explain why people do what they do

Goal setting and strategies to enhance goal pursuit for adults with acquired disability participating in rehabilitation.

Published onlineJournal ArticleMeta-AnalysisResearch Support, Non-U.S. Gov'tReviewBACKGROUND: Goal setting is considered a key component of rehabilitation for adults with acquired disability, yet there is little consensus regarding the best strategies for undertaking goal setting and in which clinical contexts. It has also been unclear what effect, if any, goal setting has on health outcomes after rehabilitation. OBJECTIVES: To assess the effects of goal setting and strategies to enhance the pursuit of goals (i.e. how goals and progress towards goals are communicated, used, or shared) on improving health outcomes in adults with acquired disability participating in rehabilitation. SEARCH METHODS: We searched CENTRAL, MEDLINE, EMBASE, four other databases and three trials registers to December 2013, together with reference checking, citation searching and contact with study authors to identify additional studies. We did not impose any language or date restrictions. SELECTION CRITERIA: Randomised controlled trials (RCTs), cluster-RCTs and quasi-RCTs evaluating the effects of goal setting or strategies to enhance goal pursuit in the context of adult rehabilitation for acquired disability. DATA COLLECTION AND ANALYSIS: Two authors independently reviewed search results for inclusion. Grey literature searches were conducted and reviewed by a single author. Two authors independently extracted data and assessed risk of bias for included studies. We contacted study authors for additional information. MAIN RESULTS: We included 39 studies (27 RCTs, 6 cluster-RCTs, and 6 quasi-RCTs) involving 2846 participants in total. Studies ranged widely regarding clinical context and participants' primary health conditions. The most common health conditions included musculoskeletal disorders, brain injury, chronic pain, mental health conditions, and cardiovascular disease.Eighteen studies compared goal setting, with or without strategies to enhance goal pursuit, to no goal setting. These studies provide very low quality evidence that including any type of goal setting in the practice of adult rehabilitation is better than no goal setting for health-related quality of life or self-reported emotional status (8 studies; 446 participants; standardised mean difference (SMD) 0.53, 95% confidence interval (CI) 0.17 to 0.88, indicative of a moderate effect size) and self-efficacy (3 studies; 108 participants; SMD 1.07, 95% CI 0.64 to 1.49, indicative of a moderate to large effect size). The evidence is inconclusive regarding whether goal setting results in improvements in social participation or activity levels, body structure or function, or levels of patient engagement in the rehabilitation process. Insufficient data are available to determine whether or not goal setting is associated with more or fewer adverse events compared to no goal setting.Fourteen studies compared structured goal setting approaches, with or without strategies to enhance goal pursuit, to 'usual care' that may have involved some goal setting but where no structured approach was followed. These studies provide very low quality evidence that more structured goal setting results in higher patient self-efficacy (2 studies; 134 participants; SMD 0.37, 95% CI 0.02 to 0.71, indicative of a small effect size) and low quality evidence for greater satisfaction with service delivery (5 studies; 309 participants; SMD 0.33, 95% CI 0.10 to 0.56, indicative of a small effect size). The evidence was inconclusive regarding whether more structured goal setting approaches result in higher health-related quality of life or self-reported emotional status, social participation, activity levels, or improvements in body structure or function. Three studies in this group reported on adverse events (death, re-hospitalisation, or worsening symptoms), but insufficient data are available to determine whether structured goal setting is associated with more or fewer adverse events than usual care.A moderate degree of heterogeneity was observed in outcomes across all studies, but an insufficient number of studies was available to permit subgroup analysis to explore the reasons for this heterogeneity. The review also considers studies which investigate the effects of different approaches to enhancing goal pursuit, and studies which investigate different structured goal setting approaches. It also reports on secondary outcomes including goal attainment and healthcare utilisation. AUTHORS' CONCLUSIONS: There is some very low quality evidence that goal setting may improve some outcomes for adults receiving rehabilitation for acquired disability. The best of this evidence appears to favour positive effects for psychosocial outcomes (i.e. health-related quality of life, emotional status, and self-efficacy) rather than physical ones. Due to study limitations, there is considerable uncertainty regarding these effects however, and further research is highly likely to change reported estimates of effect