Directional-TV algorithm for image reconstruction from limited-angular-range data

Investigation of image reconstruction from data collected over a limited-angular range in X-ray CT remains a topic of active research because it may yield insight into the development of imaging workflow of practical significance. This reconstruction problem is well-known to be challenging, however, because it is highly ill-conditioned. In the work, we investigate optimization-based image reconstruction from data acquired over a limited-angular range that is considerably smaller than the angular range in short-scan CT. We first formulate the reconstruction problem as a convex optimization program with directional total-variation (TV) constraints applied to the image, and then develop an iterative algorithm, referred to as the directional-TV (DTV) algorithm for image reconstruction through solving the optimization program. We use the DTV algorithm to reconstruct images from data collected over a variety of limited-angular ranges for breast and bar phantoms of clinical- and industrial-application relevance. The study demonstrates that the DTV algorithm accurately recovers the phantoms from data generated over a significantly reduced angular range, and that it considerably diminishes artifacts observed otherwise in reconstructions of existing algorithms. We have also obtained empirical conditions on minimal-angular ranges sufficient for numerically accurate image reconstruction with the DTV algorithm.     

科技期刊关联数据开放共享及出版政策研究

【目的】 搭建一个适合我国科技期刊关联数据出版的框架,为科技期刊制订关联数据开放共享及出版政策提供参考。【方法】 通过文献分析和网络调研方法,对国内外出版机构及科技期刊在关联数据出版方面的政策进行跟踪调研,并基于数据FAIR原则,分别从数据的可发现、可获取、可互操作和可重用4个维度进行具体分析,明确科技期刊关联数据出版的要素。【结果】 结合我国科技期刊发展现状及规划,通过共享分级并将数据出版要素纳入其中,提出符合国际数据共享政策、面向我国科技期刊的关联数据出版通用数据政策框架。【结论】 所提出的期刊关联数据共享分级策略,可为不同期刊数据政策的制订提供参考。     

Smartphone-based support system (SoberDiary) coupled with a Bluetooth breathalyser for treatment-seeking alcohol-dependent patients

BackgroundRelapse prevention in patients with alcohol dependence (AD) has long been a clinical challenge. It is vital to provide services with minial restrictions for patients to have access to continuous after-treatment care. The study was aimed to examine the benefits of a smartphone application (SoberDiary) coupled to a Bluetooth breathalyser to assist patients recovering from alcohol dependence (AD).MethodsThis study recruited 38 patients that fulfilled the DSM-IV-TR criteria for AD and who were undergoing an outpatient maintenance program for abstinence. The participants were provided a breathalyser and smartphone-equipped SoberDiary and followed for 12 weeks. The participants were divided into highly adherent (HA) and less adherent (LA) groups according to the medium number of reward points they were awarded for using the SoberDiary system throughout the follow-up period based on the average amount of time spent on using the application, the number of function modules they accessed, and the number of BrAC tests they completed each day.Results19 of the patients were classified as HA and 19 patients were classified as LA group. Members of the HA group recorded fewer drinking days and drinks consumed per week, a higher cumulative number of abstinence days, a higher abstinence rate, less pronounced anxiety, and superior quality of life.ConclusionsThe proposed smartphone-assisted support system coupled with a Bluetooth breathalyser might be a feasible supplement to conventional treatment for AD. Higher SoberDiary compliance appears to be associated with better clinical outcomes.     

The visibility of the discipline on the websites of academic nursing schools

Critical discourse analysis was used to examine the visibility of nursing as a distinct discipline on the websites of academic nursing schools in Ireland. The analysis focused on the content of the schools’ websites, including the available undergraduate curricular materials. The websites of a purposive sample of academic nursing schools in Canada, Scandinavia, and Australia were also analyzed for comparative purposes. The texts revealed that the disciplinary distinctiveness of nursing was only minimally represented on nearly all of the Irish nursing schools’ websites. There was little evidence that nursing theory was informing the form and content of nursing programs. Instead, there was evidence of eclecticism in their form and content, with much reliance on imported knowledge from other disciplines. In contrast, nursing’s disciplinary specialism was coherently and clearly articulated in website texts of the selected Canadian, Scandinavian, and Australian schools. Representations of nursing on official websites convey important messages to prospective students and to the public about the self-conceptualisation of nursing, including its knowledge forms and knowledge claims.     

Image and geometry processing with Oriented and Scalable Map

We turn the Self-organizing Map (SOM) into an Oriented and Scalable Map (OS-Map) by generalizing the neighborhood function and the winner selection. The homogeneous Gaussian neighborhood function is replaced with the matrix exponential. Thus we can specify the orientation either in the map space or in the data space. Moreover, we associate the map’s global scale with the locality of winner selection. Our model is suited for a number of graphical applications such as texture/image synthesis, surface parameterization, and solid texture synthesis. OS-Map is more generic and versatile than the task-specific algorithms for these applications. Our work reveals the overlooked strength of SOMs in processing images and geometries.     

Trends in Prevalence of Serious Psychological Distress and Depression Among Adults with Stroke in the United States

ObjectivesTo examine national trends in prevalence of serious psychological distress and depression among adults with stroke in the United States (US) from 2004 to 2017, and variations across sociodemographic subgroups.MethodsData were obtained from the household components of the 2004-2017 Medical Expenditure Panel Survey, a nationally representative survey in the US. History of stroke or transient ischemic attack was based on self-report. Psychological distress was measured by the Kessler-6 scale, and depressive symptoms were measured by the 2-item Patient Health Questionnaire. Logistic regression models were used to examine the trends in prevalence of serious psychological distress and depression overall and by age, sex, and race/ethnicity.ResultsAmong 10889 participants with stroke or transient ischemic attack, 60.0% were aged ≥ 65, 54.4% were female, and 72.2% were non-Hispanic white. The prevalence of serious psychological distress decreased from 14.9% in 2004-2005 to 11.3% in 2016-2017, corresponding to 7% lower odds every 2 years (adjusted odds ratio [aOR0.93, 95% confidence interval [CI]=0.89-0.97); and the prevalence of depression decreased from 23.1% in 2004-2005 to 18.3% in 2016-2017, corresponding to 5% lower odds every 2 years (aOR=0.95, 95% CI=0.92-0.98), after adjustment for sociodemographic characteristics, functional limitations, and antidepressant use. The trends varied significantly by age, but not sex and race/ethnicity. The overall decline was mainly driven by older adults above age 64.ConclusionsPrevalence of serious psychological distress and depression among US adults with stroke decreased from 2004 to 2017, but the burden of mental health problems remained high.     

Predictors of diabetes foot complications among patients with diabetes in Saudi Arabia

AimsTo identify risk factors and clinical biomarkers of prevalent diabetes foot complications, including foot ulcers, gangrene and amputations among patients with diabetes in Jeddah, Saudi Arabia.Methods598 diabetes patients from Jeddah participated in the current study. Patients were considered to have diabetes foot complications if they reported diagnosis of foot ulcers or gangrene or amputations in a questionnaire administered by a physician and confirmed by clinical exams. Information on socio-demographic and lifestyle variables was self-reported by patients, and several clinical markers were assessed following standard procedures.ResultsThe prevalence of diabetes foot complications in this population was 11.4%. In the multivariable model without adjustment for PAD (peripheral artery disease) and DPN (diabetes peripheral neuropathy), non-Saudi nationality, longer diabetes duration and insulin use was significantly associated with higher diabetes foot complications prevalence. Each 1 g/L increase of hemoglobin was associated with 2.8% lower prevalence of diabetes foot complications. In the multivariable model adjusting for PAD and DPN, the previously observed associations except for nationality were no longer significant. Patients with both DPN and PAD had 9.73 times the odds of diabetes foot complications compared to the patients with neither condition.ConclusionIn this population, longer diabetes duration, insulin use, lower hemoglobin levels and non-Saudi nationality were associated with higher prevalence of foot complications. These associations were largely explained by the presence of DPN and PAD except for non-Saudi nationality. Diabetes patients with both DPN and PAD had nearly 10-fold increased risk of foot complications than those with neither condition.