An Image Statistics–Based Model for Fixation Prediction

The problem of predicting where people look at, or equivalently salient region detection, has been related to the statistics of several types of low-level image features. Among these features, contrast and edge information seem to have the highest correlation with the fixation locations. The contrast distribution of natural images can be adequately characterized using a two-parameter Weibull distribution. This distribution catches the structure of local contrast and edge frequency in a highly meaningful way. We exploit these observations and investigate whether the parameters of the Weibull distribution constitute a simple model for predicting where people fixate when viewing natural images. Using a set of images with associated eye movements, we assess the joint distribution of the Weibull parameters at fixated and non-fixated regions. Then, we build a simple classifier based on the log-likelihood ratio between these two joint distributions. Our results show that as few as two values per image region are already enough to achieve a performance comparable with the state-of-the-art in bottom-up saliency prediction

Patient safety in primary care: a survey of general practitioners in the Netherlands

Contains fulltext : 89814.pdf (publisher's version ) (Open Access)BACKGROUND: Primary care encompasses many different clinical domains and patient groups, which means that patient safety in primary care may be equally broad. Previous research on safety in primary care has focused on medication safety and incident reporting. In this study, the views of general practitioners (GPs) on patient safety were examined. METHODS: A web-based survey of a sample of GPs was undertaken. The items were derived from aspects of patient safety issues identified in a prior interview study. The questionnaire used 10 clinical cases and 15 potential risk factors to explore GPs' views on patient safety. RESULTS: A total of 68 GPs responded (51.5% response rate). None of the clinical cases was uniformly judged as particularly safe or unsafe by the GPs. Cases judged to be unsafe by a majority of the GPs concerned either the maintenance of medical records or prescription and monitoring of medication. Cases which only a few GPs judged as unsafe concerned hygiene, the diagnostic process, prevention and communication. The risk factors most frequently judged to constitute a threat to patient safety were a poor doctor-patient relationship, insufficient continuing education on the part of the GP and a patient age over 75 years. Language barriers and polypharmacy also scored high. Deviation from evidence-based guidelines and patient privacy in the reception/waiting room were not perceived as risk factors by most of the GPs. CONCLUSION: The views of GPs on safety and risk in primary care did not completely match those presented in published papers and policy documents. The GPs in the present study judged a broader range of factors than in previously published research on patient safety in primary care, including a poor doctor-patient relationship, to pose a potential threat to patient safety. Other risk factors such as infection prevention, deviation from guidelines and incident reporting were judged to be less relevant than by policy makers

Infant head growth in male siblings of children with and without autism spectrum disorders

Previous research has indicated that children with autism exhibit accelerated head growth (HG) in infancy, although the timing of acceleration varies between studies. We examined infant HG trajectory as a candidate autism endophenotype by studying sibling pairs. We retrospectively obtained serial head orbitofrontal circumference measurements of: a) 48 sibling pairs in which one (n = 28) or both (n = 20) sibs were affected by an autism spectrum disorder (ASD); and b) 85 control male sibling pairs. Rate of HG of ASD subjects was slightly accelerated compared to controls, but the magnitude of difference was below the limit of reliability of standard measurement methods. Sibling intra class correlation for rate of HG was highly statistically significant; the magnitude was significantly stronger among autism-affected families (ICC = .63) than among controls (ICC = .26), p < .01. Infant HG trajectory appears familial—possibly endophenotypic—but was not a reliable marker of autism risk among siblings of ASD probands in this sample

What do family physicians consider an error? A comparison of definitions and physician perception

BACKGROUND: Physicians are being asked to report errors from primary care, but little is known about how they apply the term "error." This study qualitatively assesses the relationship between the variety of error definitions found in the medical literature and physicians' assessments of whether an error occurred in a series of clinical scenarios. METHODS: A systematic literature review and pilot survey results were analyzed qualitatively to search for insights into what may affect the use of the term error. The National Library of Medicine was systematically searched for medical error definitions. Survey participants were a random sample of active members of the American Academy of Family Physicians (AAFP) and a selected sample of family physician patient safety "experts." A survey consisting of 5 clinical scenarios with problems (wrong test performed, abnormal result not followed-up, abnormal result overlooked, blood tube broken and missing scan results) was sent by mail to AAFP members and by e-mail to the experts. Physicians were asked to judge if an error occurred. A qualitative analysis was performed via "immersion and crystallization" of emergent insights from the collected data. RESULTS: While one definition, that originated by James Reason, predominated the literature search, we found 25 different definitions for error in the medical literature. Surveys were returned by 28.5% of 1000 AAFP members and 92% of 25 experts. Of the 5 scenarios, 100% felt overlooking an abnormal result was an error. For other scenarios there was less agreement (experts and AAFP members, respectively agreeing an error occurred): 100 and 87% when the wrong test was performed, 96 and 87% when an abnormal test was not followed up, 74 and 62% when scan results were not available during a patient visit, and 57 and 47% when a blood tube was broken. Through qualitative analysis, we found that three areas may affect how physicians make decisions about error: the process that occurred vs. the outcome that occurred, rare vs. common occurrences and system vs. individual responsibility CONCLUSION: There is a lack of consensus about what constitutes an error both in the medical literature and in decision making by family physicians. These potential areas of confusion need further study

Redefining risk research priorities for nanomaterials

Chemical-based risk assessment underpins the current approach to responsible development of nanomaterials (NM). It is now recognised, however, that this process may take decades, leaving decision makers with little support in the near term. Despite this, current and near future research efforts are largely directed at establishing (eco)toxicological and exposure data for NM, and comparatively little research has been undertaken on tools or approaches that may facilitate near-term decisions, some of which we briefly outline in this analysis. We propose a reprioritisation of NM risk research efforts to redress this imbalance, including the development of more adaptive risk governance frameworks, alternative/complementary tools to risk assessment, and health and environment surveillance

In Caenorhabditis elegans Nanoparticle-Bio-Interactions Become Transparent: Silica-Nanoparticles Induce Reproductive Senescence

While expectations and applications of nanotechnologies grow exponentially, little is known about interactions of engineered nanoparticles with multicellular organisms. Here we propose the transparent roundworm Caenorhabditis elegans as a simple but anatomically and biologically well defined animal model that allows for whole organism analyses of nanoparticle-bio-interactions. Microscopic techniques showed that fluorescently labelled nanoparticles are efficiently taken up by the worms during feeding, and translocate to primary organs such as epithelial cells of the intestine, as well as secondary organs belonging to the reproductive tract. The life span of nanoparticle-fed Caenorhabditis elegans remained unchanged, whereas a reduction of progeny production was observed in silica-nanoparticle exposed worms versus untreated controls. This reduction was accompanied by a significant increase of the ‘bag of worms’ phenotype that is characterized by failed egg-laying and usually occurs in aged wild type worms. Experimental exclusion of developmental defects suggests that silica-nanoparticles induce an age-related degeneration of reproductive organs, and thus set a research platform for both, detailed elucidation of molecular mechanisms and high throughput screening of different nanomaterials by analyses of progeny production

Evolving health information technology and the timely availability of visit diagnoses from ambulatory visits: A natural experiment in an integrated delivery system

<p>Abstract</p> <p>Background</p> <p>Health information technology (HIT) may improve health care quality and outcomes, in part by making information available in a timelier manner. However, there are few studies documenting the changes in timely availability of data with the use of a sophisticated electronic medical record (EMR), nor a description of how the timely availability of data might differ with different types of EMRs. We hypothesized that timely availability of data would improve with use of increasingly sophisticated forms of HIT.</p> <p>Methods</p> <p>We used an historical observation design (2004–2006) using electronic data from office visits in an integrated delivery system with three types of HIT: Basic, Intermediate, and Advanced. We calculated the monthly percentage of visits using the various types of HIT for entry of visit diagnoses into the delivery system's electronic database, and the time between the visit and the availability of the visit diagnoses in the database.</p> <p>Results</p> <p>In January 2004, when only Basic HIT was available, 10% of office visits had diagnoses entered on the same day as the visit and 90% within a week; 85% of office visits used paper forms for recording visit diagnoses, 16% used Basic at that time. By December 2006, 95% of all office visits had diagnoses available on the same day as the visit, when 98% of office visits used some form of HIT for entry of visit diagnoses (Advanced HIT for 67% of visits).</p> <p>Conclusion</p> <p>Use of HIT systems is associated with dramatic increases in the timely availability of diagnostic information, though the effects may vary by sophistication of HIT system. Timely clinical data are critical for real-time population surveillance, and valuable for routine clinical care.</p

Initial clinical experience with frameless optically guided stereotactic radiosurgery/radiotherapy in pediatric patients

The objective of this study is to report our initial experience treating pediatric patients with central nervous system tumors using a frameless, optically guided linear accelerator. Pediatric patients were selected for treatment after evaluation by a multidisciplinary neuro-oncology team including neurosurgery, neurology, pathology, oncology, and radiation oncology. Prior to treatment, all patients underwent treatment planning using magnetic resonance imaging (MRI) and treatment simulation on a standard computed tomography scanner (CT). For CT simulation, patients were fitted with a customized plastic face mask with a bite block attached to an optical array with four reflective markers. After ensuring adequate reproducibility, these markers were tracked during treatment by an infra-red camera. All treatments were delivered on a Varian Trilogy linear accelerator. The follow-up period ranges from 1–18 months, with a median follow-up of 6 months. Nine patients, ages ranging from 12 to 19 years old (median age 15 years old), with a variety of tumors have been treated. Patients were treated for juvenile pilocytic astrocytoma (JPA; n = 2), pontine low-grade astrocytoma (n = 1), pituitary adenoma (n = 3), metastatic medulloblastoma (n = 1), acoustic neuroma (n = 1), and pineocytoma (n = 1). We followed patients for a median of 12 months (range 3–18 months) with no in-field failures and were able to obtain encouraging toxicity profiles. Frameless stereotactic optically guided radiosurgery and radiotherapy provides a feasible and accurate tool to treat a number of benign and malignant tumors in children with minimal treatment-related morbidity

Patient safety culture measurement in general practice. Clinimetric properties of 'SCOPE'

<p>Abstract</p> <p>Background</p> <p>A supportive patient safety culture is considered to be an essential condition for improving patient safety. Assessing the current safety culture in general practice may be a first step to target improvements. To that end, we studied internal consistency and construct validity of a safety culture questionnaire for general practice (SCOPE) which was derived from a comparable questionnaire for hospitals (Dutch-HSOPS).</p> <p>Methods</p> <p>The survey was conducted among caregivers of Dutch general practice as part of an ongoing quality accreditation process using a 46 item questionnaire. We conducted factor analyses and studied validity by calculating correlations between the subscales and testing the hypothesis that respondents' <it>patient safety grade </it>of their practices correlated with their scores on the questionnaire.</p> <p>Results</p> <p>Of 72 practices 294 respondents completed the questionnaire. Eight factors were identified concerning <it>handover and teamwork, support and fellowship, communication openness, feedback and learning from error, intention to report events, adequate procedures and staffing, overall perceptions of patient safety </it>and <it>expectations and actions of managers</it>. Cronbach's alpha of the factors rated between 0.64 and 0.85. The subscales intercorrelated moderately, except for the factor about intention to report events. Respondents who graded patient safety highly scored significantly higher on the questionnaire than those who did not.</p> <p>Conclusions</p> <p>The SCOPE questionnaire seems an appropriate instrument to assess patient safety culture in general practice. The clinimetric properties of the SCOPE are promising, but future research should confirm the factor structure and construct of the SCOPE and delineate its responsiveness to changes in safety culture over time.</p