Environmental data mining and modeling based on machine learning algorithms and geostatistics

The paper presents some contemporary approaches to spatial environmental data analysis. The main topics are concentrated on the decision-oriented problems of environmental spatial data mining and modeling: valorization and representativity of data with the help of exploratory data analysis, spatial predictions, probabilistic and risk mapping, development and application of conditional stochastic simulation models. The innovative part of the paper presents integrated/hybrid model-machine learning (ML) residuals sequential simulations-MLRSS. The models are based on multilayer perceptron and support vector regression ML algorithms used for modeling long-range spatial trends and sequential simulations of the residuals. NIL algorithms deliver non-linear solution for the spatial non-stationary problems, which are difficult for geostatistical approach. Geostatistical tools (variography) are used to characterize performance of ML algorithms, by analyzing quality and quantity of the spatially structured information extracted from data with ML algorithms. Sequential simulations provide efficient assessment of uncertainty and spatial variability. Case study from the Chernobyl fallouts illustrates the performance of the proposed model. It is shown that probability mapping, provided by the combination of ML data driven and geostatistical model based approaches, can be efficiently used in decision-making process. (C) 2003 Elsevier Ltd. All rights reserved.

Médecines complémentaires: vers un consensus evidence- based à l'hôpital universitaire [Complementary and alternative medicines (CAM): towards an evidence-based consensus in the university hospital].

While a popular vote supported a new article on complementary and alternative medicines (CAM) in the Swiss Constitution, this assessment in 14 wards of the University Hospital of Lausanne, Switzerland, attempted at answering the question: How can CAM use be better taken into account and patients informed with more rigor and respect for their choices? Confronted with a review of the literature (> 2000 publications in "Evidence-based complementary medicines" since 1998), respondents declared their ignorance of the clinical data presently available on CAM. All were in favour of more teaching and information on the subject, plus an official statement from the Hospital direction, ensuring production and diffusion of rigorous and clinically significant information on CAM.

Quantitative Ultrasound of the Heel and Fracture Risk Assessment: an Updated Meta-Analysis

Objectives: Quantitative ultrasound (QUS) is an attractive method for assessing fracture risk because it is portable, inexpensive, without ionizing radiation, and available in areas of the world where DXA is not readily accessible or affordable. However, the diversity of QUS scanners and variability of fracture outcomes measured in different studies is an important obstacle to widespread utilisation of QUS for fracture risk assessment. We aimed in this review to assess the predictive power of heel QUS for fractures considering different characteristics of the association (QUS parameters and fracture outcomes measured, QUS devices, study populations, and independence from DXA-measured bone density).Materials/Methods : We conducted an inverse-variance randomeffects meta-analysis of prospective studies with heel QUS measures at baseline and fracture outcomes in their follow-up. Relative risks (RR) per standard deviation (SD) of different QUS parameters (broadband ultrasound attenuation [BUA], speed of sound &SOS;, stiffness index &SI;, and quantitative ultrasound index [QUI]) for various fracture outcomes (hip, vertebral, any clinical, any osteoporotic, and major osteoporotic fractures) were reported based on study questions.Results : 21 studies including 55,164 women and 13,742 men were included with a total follow-up of 279,124 person-years. All four QUS parameters were associated with risk of different fractures. For instance, RR of hip fracture for 1 SD decrease of BUA was 1.69 (95% CI 1.43-2.00), SOS was 1.96 (95% CI 1.64-2.34), SI was 2.26 (95%CI 1.71-2.99), and QUI was 1.99 (95% CI 1.49-2.67). Validated devices from different manufacturers predicted fracture risks with a similar performance (meta-regression p-values>0.05 for difference of devices). There was no sign of publication bias among the studies. QUS measures predicted fracture with a similar performance in men and women. Meta-analysis of studies with QUS measures adjusted for hip DXA showed a significant and independent association with fracture risk (RR/SD for BUA =1.34 [95%CI 1.22-1.49]).Conclusions : This study confirms that QUS of the heel using validated devices predicts risk of different fracture outcomes in elderly men and women. Further research and international collaborations are needed for standardisation of QUS parameters across various manufacturers and inclusion of QUS in fracture risk assessment tools. Disclosure of Interest : None declared.

Local alignment refinement using structural assessment.

Homology modeling is the most commonly used technique to build a three-dimensional model for a protein sequence. It heavily relies on the quality of the sequence alignment between the protein to model and related proteins with a known three dimensional structure. Alignment quality can be assessed according to the physico-chemical properties of the three dimensional models it produces.In this work, we introduce fifteen predictors designed to evaluate the properties of the models obtained for various alignments. They consist of an energy value obtained from different force fields (CHARMM, ProsaII or ANOLEA) computed on residue selected around misaligned regions. These predictors were evaluated on ten challenging test cases. For each target, all possible ungapped alignments are generated and their corresponding models are computed and evaluated.The best predictor, retrieving the structural alignment for 9 out of 10 test cases, is based on the ANOLEA atomistic mean force potential and takes into account residues around misaligned secondary structure elements. The performance of the other predictors is significantly lower. This work shows that substantial improvement in local alignments can be obtained by careful assessment of the local structure of the resulting models.

Assessment of the 10-year probability of osteoporotic hip fracture combining clinical risk factors and heel bone ultrasound: the EPISEM prospective cohort of 12,958 elderly women.

This study aimed to develop a hip screening tool that combines relevant clinical risk factors (CRFs) and quantitative ultrasound (QUS) at the heel to determine the 10-yr probability of hip fractures in elderly women. The EPISEM database, comprised of approximately 13,000 women 70 yr of age, was derived from two population-based white European cohorts in France and Switzerland. All women had baseline data on CRFs and a baseline measurement of the stiffness index (SI) derived from QUS at the heel. Women were followed prospectively to identify incident fractures. Multivariate analysis was performed to determine the CRFs that contributed significantly to hip fracture risk, and these were used to generate a CRF score. Gradients of risk (GR; RR/SD change) and areas under receiver operating characteristic curves (AUC) were calculated for the CRF score, SI, and a score combining both. The 10-yr probability of hip fracture was computed for the combined model. Three hundred seven hip fractures were observed over a mean follow-up of 3.2 yr. In addition to SI, significant CRFs for hip fracture were body mass index (BMI), history of fracture, an impaired chair test, history of a recent fall, current cigarette smoking, and diabetes mellitus. The average GR for hip fracture was 2.10 per SD with the combined SI + CRF score compared with a GR of 1.77 with SI alone and of 1.52 with the CRF score alone. Thus, the use of CRFs enhanced the predictive value of SI alone. For example, in a woman 80 yr of age, the presence of two to four CRFs increased the probability of hip fracture from 16.9% to 26.6% and from 52.6% to 70.5% for SI Z-scores of +2 and -3, respectively. The combined use of CRFs and QUS SI is a promising tool to assess hip fracture probability in elderly women, especially when access to DXA is limited.

Assessment of inflammatory Bowel Disease patient's needs and problems from a nursing perspective

BACKGROUND: In this study, we aimed at assessing Inflammatory Bowel Disease patients' needs and current nursing practice to investigate to what extent consensus statements (European Crohn's and Colitis Organization) on the nursing roles in caring for patients with IBD concur with local practice. METHODS: We used a mixed-method convergent design to combine quantitative data prospectively collected in the Swiss IBD cohort study and qualitative data from structured interviews with IBD healthcare experts. Symptoms, quality of life, and anxiety and depression scores were retrieved from physician charts and patient self-reported questionnaires. Descriptive analyses were performed based on quantitative and qualitative data. RESULTS: 230 patients of a single center were included, 60% of patients were males, and median age was 40 (range 18-85). The prevalence of abdominal pain was 42%. Self-reported data were obtained from 75 out of 230 patients. General health was perceived significantly lower compared with the general population (p < 0.001). Prevalence of tiredness was 73%; sleep problems, 78%; issues related to work, 20%; sexual constraints, 35%; diarrhea, 67%; being afraid of not finding a bathroom, 42%; depression, 11%; and anxiety symptoms, 23%. According to experts' interviews, the consensus statements are found mostly relevant with many recommendations that are not yet realized in clinical practice. CONCLUSION: Identified prevalence may help clinicians in detecting patients at risk and improve patient management. © 2015 S. Karger AG, Basel.

Differential monocular vs. binocular pupil responses from melanopsin-based photoreception in patients with anterior ischemic optic neuropathy.

We examined the effect of anterior ischemic optic neuropathy (AION) on the activity of intrinsically photosensitive retinal ganglion cells (ipRGCs) using the pupil as proxy. Eighteen patients with AION (10 unilateral, 8 bilateral) and 29 age-matched control subjects underwent chromatic pupillometry. Red and blue light stimuli increasing in 0.5 log steps were presented to each eye independently under conditions of dark and light adaptation. The recorded pupil contraction was plotted against stimulus intensity to generate scotopic and photopic response curves for assessment of synaptically-mediated ipRGC activity. Bright blue light stimuli presented monocularly and binocularly were used for melanopsin activation. The post-stimulus pupil size (PSPS) at the 6th second following stimulus offset was the marker of intrinsic ipRGC activity. Finally, questionnaires were administered to assess the influence of ipRGCs on sleep. The pupil response and PSPS to all monocularly-presented light stimuli were impaired in AION eyes, indicating ipRGC dysfunction. To binocular light stimulation, the PSPS of AION patients was similar to that of controls. There was no difference in the sleep habits of the two groups. Thus after ischemic injury to one or both optic nerves, the summated intrinsic ipRGC activity is preserved when both eyes receive adequate light exposure.

Implementing evidence-based patient and family education on oral anticoagulation therapy: a community-based participatory project.

AIMS AND OBJECTIVES: This study aimed at developing and implementing evidence-based patient and family education on oral anticoagulation therapy. BACKGROUND: The number of persons with chronic diseases who live at home is increasing. They have to manage multiple diseases and complex treatments. One such treatment is oral anticoagulation therapy, a high risk variable dose medication. Adherence to oral anticoagulation therapy is jeopardised by limited information about the medications, their risk and complications, the impact of individual daily routine and the limited inclusion of family members in education. Hence, improved and tailored education is essential for patients and families to manage oral anticoagulation therapy at home. DESIGN AND METHODS: A community-based participatory research design combined with the Precede-Proceed model was used including a systematic literature review, posteducation analysis, an online nurse survey, a documentation analysis and patient/family interviews. The study was conducted between April 2010-December 2012 at a department of general internal medicine in a teaching hospital in Switzerland. Participants were the department's nursing and medical professionals including the patients and their families. RESULTS: The evidence-based patient and family education on oral anticoagulation therapy emerged comprising a learning assessment, teaching units, clarification of responsibilities of nurse professionals and documentation guidelines. CONCLUSION AND CLINICAL RELEVANCE: The inclusion of the whole department has contributed to the development and implementation of this evidence-based patient family education on oral anticoagulation therapy, which encompasses local characteristics and patient preferences. This education is now being used throughout the department.

External assessment of the Early Mortality Risk Score in patients with adenocarcinoma undergoing pancreaticoduodenectomy.

BACKGROUND: Pancreaticoduodenectomies (PD) still have a substantial mortality rate. Recently, different scores have been published to predict the mortality risk pre-operatively after PD. This retrospective study was designed to perform an external assessment of an Early Mortality Risk Score (EMRS). METHODS: From 2000 to 2012, all PD cases performed at our institution were documented. Only patients treated for pancreatic head adenocarcinomas were included. Survival time and EMRS (based on age, tumour size, tumour differentiation and comorbidities) were calculated for every patient. Relative risks (RR) of early death 9 and 12 months after PD were then calculated. RESULTS: Of 270 PD for various aetiologies, 120 PD for adenocarcinomas were included. The median follow-up was 37 months, and the overall median survival was 19 months. EMRS of 4 showed a mortality RR of 5.1 at 9 months (P = 0.048) and of 4.5 at 12 months (P = 0.020). CONCLUSIONS: EMRS of 4 is a predictor of tumour-related mortality at 9 and 12 months after PD for adenocarcinoma. The EMRS was externally assessed in our patient cohort and can be implemented in clinical practice. Clinical implications of this score still need to be studied.

CoDiab-VD: protocol of a prospective population-based cohort study on diabetes care in Switzerland.

BACKGROUND: Diabetes represents an increasing health burden worldwide. In 2010, the Public Health Department of the canton of Vaud (Switzerland) launched a regional diabetes programme entitled "Programme cantonal Diabète" (PcD), with the objectives to both decrease the incidence of diabetes and improve care for patients with diabetes. The cohort entitled CoDiab-VD emerged from that programme. It specifically aimed at following quality of diabetes care over time, at evaluating the coverage of the PcD within this canton and at assessing the impact of the PcD on care of patients with diabetes. METHODS/DESIGN: The cohort CoDiab-VD is a prospective population-based cohort study. Patients with diabetes were recruited in two waves (autumn 2011--summer 2012) through community pharmacies. Eligible participants were non-institutionalised adult patients (≥ 18 years) with diabetes diagnosed for at least one year, residing in the canton of Vaud and coming to a participating pharmacy with a diabetes-related prescription. Women with gestational diabetes, people with obvious cognitive impairment or insufficient command of French were not eligible. Self-reported data collected, included the following primary outcomes: processes-of-care indicators (annual checks) and outcomes of care such as HbA1C, (health-related) quality of life measures (Short Form-12 Health Survey--SF-12, Audit of Diabetes-Dependent Quality of Life 19--ADDQoL) and Patient Assessment of Chronic Illness Care (PACIC). Data on diabetes, health status, healthcare utilisation, health behaviour, self-management activities and support, knowledge of, or participation to, campaigns/activities proposed by the PcD, and socio-demographics were also obtained. For consenting participants, physicians provided few additional pieces of information about processes and laboratory results. Participants will be followed once a year, via a mailed self-report questionnaire. The core of the follow-up questionnaires will be similar to the baseline one, with the addition of thematic modules adapting to the development of the PcD. Physicians will be contacted every 2 years. DISCUSSION: CoDiab-VD will allow obtaining a broad picture of the care of patients with diabetes, as well as their needs regarding their chronic condition. The data will be used to evaluate the PcD and help prioritise targeted actions. TRIAL REGISTRATION: This study is registered with ClinicalTrials.gov, identifier NCT01902043, July 9, 2013.

Social justice in education : how the function of selection in educational institutions predicts support for (non)egalitarian assessment practices

Educational institutions are considered a keystone for the establishment of a meritocratic society. They supposedly serve two functions: an educational function that promotes learning for all, and a selection function that sorts individuals into different programs, and ultimately social positions, based on individual merit. We study how the function of selection relates to support for assessment practices known to harm vs. benefit lower status students, through the perceived justice principles underlying these practices. We study two assessment practices: normative assessment-focused on ranking and social comparison, known to hinder the success of lower status students-and formative assessment-focused on learning and improvement, known to benefit lower status students. Normative assessment is usually perceived as relying on an equity principle, with rewards being allocated based on merit and should thus appear as positively associated with the function of selection. Formative assessment is usually perceived as relying on corrective justice that aims to ensure equality of outcomes by considering students' needs, which makes it less suitable for the function of selection. A questionnaire measuring these constructs was administered to university students. Results showed that believing that education is intended to select the best students positively predicts support for normative assessment, through increased perception of its reliance on equity, and negatively predicts support for formative assessment, through reduced perception of its ability to establish corrective justice. This study suggests that the belief in the function of selection as inherent to educational institutions can contribute to the reproduction of social inequalities by preventing change from assessment practices known to disadvantage lowerstatus student, namely normative assessment, to more favorable practices, namely formative assessment, and by promoting matching beliefs in justice principles.

Inter-rater Reliability of Criteria-Based Content Analysis of Children's Statements of Abuse.

The evaluation of children's statements of sexual abuse cases in forensic cases is critically important and must and reliable. Criteria-based content analysis (CBCA) is the main component of the statement validity assessment (SVA), which is the most frequently used approach in this setting. This study investigated the inter-rater reliability (IRR) of CBCA in a forensic context. Three independent raters evaluated the transcripts of 95 statements of sexual abuse. IRR was calculated for each criterion, total score, and overall evaluation. The IRR was variable for the criteria, with several being unsatisfactory. But high IRR was found for the total CBCA scores (Kendall's W = 0.84) and for overall evaluation (Kendall's W = 0.65). Despite some shortcomings, SVA remains a robust method to be used in the comprehensive evaluation of children's statements of sexual abuse in the forensic setting. However, the low IRR of some CBCA criteria could justify some technical improvements.

Assessment of the role of LASER-Doppler in the treatment of port-wine stains in infants.

BACKGROUND: Port-wine stains (PWS) are malformations of capillaries in 0.3% of newborn children. The treatment of choice is by pulsed dye LASER (PDL), and requires several sessions. The efficacy of this treatment is at present evaluated on the basis of clinical inspection and of digital photographs taken throughout the treatment. LASER-Doppler imaging (LDI) is a noninvasive method of imaging the perfusion of the tissues by the microcirculatory system (capillaries). The aim of this paper is to demonstrate that LDI allows a quantitative, numerical evaluation of the efficacy of the PDL treatment of PWS. METHOD: The PDL sessions were organized according to the usual scheme, every other month, from September 1, 2012, to September 30, 2013. LDI imaging was performed at the start and at the conclusion of the PDL treatment, and simultaneously on healthy skin in order to obtain reference values. The results evidenced by LDI were analyzed according to the "Wilcoxon signed-rank" test before and after each session, and in the intervals between the three PDL treatment sessions. RESULTS: Our prospective study is based on 20 new children. On average, the vascularization of the PWS was reduced by 56% after three laser sessions. Compared with healthy skin, initial vascularization of PWS was 62% higher than that of healthy skin at the start of treatment, and 6% higher after three sessions. During the 2 months between two sessions, vascularization of the capillary network increased by 27%. CONCLUSION: This study shows that LDI can demonstrate and measure the efficacy of PDL treatment of PWS in children. The figures obtained when measuring the results by LDI corroborate the clinical assessments and may allow us to refine, and perhaps even modify, our present use of PDL and thus improve the efficacy of the treatment.

Assessment of Immature Platelet Fraction in the Diagnosis of Wiskott-Aldrich Syndrome.

Children with Wiskott-Aldrich syndrome (WAS) are often first diagnosed with immune thrombocytopenia (ITP), potentially leading to both inappropriate treatment and the delay of life-saving definitive therapy. WAS is traditionally differentiated from ITP based on the small size of WAS platelets. In practice, microthrombocytopenia is often not present or not appreciated in children with WAS. To develop an alternative method of differentiating WAS from ITP, we retrospectively reviewed all complete blood counts and measurements of immature platelet fraction (IPF) in 18 subjects with WAS and 38 subjects with a diagnosis of ITP treated at our hospital. Examination of peripheral blood smears revealed a wide range of platelet sizes in subjects with WAS. Mean platelet volume (MPV) was not reported in 26% of subjects, and subjects in whom MPV was not reported had lower platelet counts than did subjects in whom MPV was reported. Subjects with WAS had a lower IPF than would be expected for their level of thrombocytopenia, and the IPF in subjects with WAS was significantly lower than in subjects with a diagnosis of ITP. Using logistic regression, we developed and validated a rule based on platelet count and IPF that was more sensitive for the diagnosis of WAS than was the MPV, and was applicable regardless of the level of platelets or the availability of the MPV. Our observations demonstrate that MPV is often not available in severely thrombocytopenic subjects, which may hinder the diagnosis of WAS. In addition, subjects with WAS have a low IPF, which is consistent with the notion that a platelet production defect contributes to the thrombocytopenia of WAS. Knowledge of this detail of WAS pathophysiology allows to differentiate WAS from ITP with increased sensitivity, thereby allowing a physician to spare children with WAS from inappropriate treatment, and make definitive therapy available in a timely manner.

2015 Update on Acute Adverse Reactions to Gadolinium based Contrast Agents in Cardiovascular MR. Large Multi-National and Multi-Ethnical Population Experience With 37788 Patients From the EuroCMR Registry.

OBJECTIVES: Specifically we aim to demonstrate that the results of our earlier safety data hold true in this much larger multi-national and multi-ethnical population. BACKGROUND: We sought to re-evaluate the frequency, manifestations, and severity of acute adverse reactions associated with administration of several gadolinium- based contrast agents during routine CMR on a European level. METHODS: Multi-centre, multi-national, and multi-ethnical registry with consecutive enrolment of patients in 57 European centres. RESULTS: During the current observation 37,788 doses of Gadolinium based contrast agent were administered to 37,788 patients. The mean dose was 24.7 ml (range 5-80 ml), which is equivalent to 0.123 mmol/kg (range 0.01 - 0.3 mmol/kg). Forty-five acute adverse reactions due to contrast administration occurred (0.12%). Most reactions were classified as mild (43 of 45) according to the American College of Radiology definition. The most frequent complaints following contrast administration were rashes and hives (15 of 45), followed by nausea (10 of 45) and flushes (10 of 45). The event rate ranged from 0.05% (linear non-ionic agent gadodiamide) to 0.42% (linear ionic agent gadobenate dimeglumine). Interestingly, we also found different event rates between the three main indications for CMR ranging from 0.05% (risk stratification in suspected CAD) to 0.22% (viability in known CAD). CONCLUSIONS: The current data indicate that the results of the earlier safety data hold true in this much larger multi-national and multi-ethnical population. Thus, the "off-label" use of Gadolinium based contrast in cardiovascular MR should be regarded as safe concerning the frequency, manifestation and severity of acute events.