ABC random forests for Bayesian parameter inference

This preprint has been reviewed and recommended by Peer Community In Evolutionary Biology (http://dx.doi.org/10.24072/pci.evolbiol.100036). Approximate Bayesian computation (ABC) has grown into a standard methodology that manages Bayesian inference for models associated with intractable likelihood functions. Most ABC implementations require the preliminary selection of a vector of informative statistics summarizing raw data. Furthermore, in almost all existing implementations, the tolerance level that separates acceptance from rejection of simulated parameter values needs to be calibrated. We propose to conduct likelihood-free Bayesian inferences about parameters with no prior selection of the relevant components of the summary statistics and bypassing the derivation of the associated tolerance level. The approach relies on the random forest methodology of Breiman (2001) applied in a (non parametric) regression setting. We advocate the derivation of a new random forest for each component of the parameter vector of interest. When compared with earlier ABC solutions, this method offers significant gains in terms of robustness to the choice of the summary statistics, does not depend on any type of tolerance level, and is a good trade-off in term of quality of point estimator precision and credible interval estimations for a given computing time. We illustrate the performance of our methodological proposal and compare it with earlier ABC methods on a Normal toy example and a population genetics example dealing with human population evolution. All methods designed here have been incorporated in the R package abcrf (version 1.7) available on CRAN.Comment: Main text: 24 pages, 6 figures Supplementary Information: 14 pages, 5 figure

Trends in the treatment of orthopaedic prosthetic infections

The most commonly used therapy for prosthetic joint infection is a two-stage prosthetic exchange separated by 6 weeks of intravenous antibiotic therapy. This often results in long periods of hospitalization, morbidity, severe functional impairment and sometimes increased mortality. Therefore novel and challenging therapeutic approaches have been attempted, particularly in hip prosthetic infection. This includes, whenever possible, according to the type of microorganism, antibacterial susceptibility and clinical presentation (including age and comorbidities): (i) less aggressive surgical techniques (debridement and prosthesis retention, or re-implantation with a single-stage exchange arthroplasty); and (ii) antibiotic combinations active against biofilm-associated bacteria, including rifampicin (particularly with quinolones) with excellent bio-availability which allow prolonged and efficient oral therap

Comparison of fasting and non-fasting lipid profiles in a large cohort of patients presenting at a community hospital

Objective: To compare the fasting and non-fasting lipid profile including ApoB in a cohort of patients from a community setting. Our purpose was to determine the proportion of results that could be explained by the known biological variation in the fasting state and to examine the additional impact of non-fasting on these same lipid parameters. Methods: 1093 adult outpatients with fasting lipid requests were recruited from February to September 2016 at the blood collection sites of the Moncton Hospital. Participants were asked to come back in the next 3–4 days after having eaten a regular breakfast to have their blood drawn for a non-fasting lipid profile. Results: 91.6% of patients in this study had a change in total cholesterol that fell within the biological variation expected for this parameter. Similar results were seen for HDL-C (94.3%) non-HDL-C (88.8%) and ApoB (93.0%). A smaller number of patients fell within the biological variation expected for TG (78.8%) and LDL-C (74.6%). An average TG increase of 0.3 mmol/L was observed in fed patients no matter the level of fasting TG. A gradual widening in the range of change in TG concentration was observed as fasting TG increased. Similar results were seen in diabetic patients. Conclusion: Outside of LDL-C and TG, little changes were seen in lipid parameters in the postprandial state. A large part of these changes could be explained by the biological variation. We observed a gradual widening in the range of increase in TG for patients with higher fasting TG. Non-HDL-C and ApoB should be the treatment target of choice for patients in the non-fasting state

Pendidikan Kewarganegaraan untuk Membangun Wawasan Global Warga Negara Muda

Penelitian ini bertujuan untuk menemukan nilai-nilai dasar yang perlu dikembangkan dalam pendidikan kewarganegaraan untuk membangun wawasan global warga negara muda. Penelitian menggunakan pendekatan kualitatif dengan metode grounded theory. Sumber data terdiri atas sumber kepustakaan dan responden yang dipilih dengan menggunakan metode purposive sampling.Teknik pengumpulan data menggunakan studi dokumentasi, wawancara, dan observasi. Analisis data menggunakan analisis induktif. Hasil penelitian menunjukkan bahwa nilai-nilai dasar yang perlu dikembangkan dalam pendidikan kewarganegaraan untuk membangun wawasan global warga negara muda dalam konteks Indonesia antara lain adalah ketuhanan, kemanusiaan, persatuan, kerakyatan, keadilan sosial, kompetisi, menghormati orang lain, kemerdekaan, dan perdamaian

Towards an engineering approach for advanced interaction techniques in 3D environments

National audienceIn recent years, Virtual Environments have appeared in new areas such as mass-market, web or mobile situations. In parallel, advanced forms ofinteractions are emerging such as tactile, mixed, tangible or spatial user interfaces, promoting ease of learning and use. To contribute to the democratization of 3D Virtual Environments(3DVE) and their use by persons who are not experts in 3D and occasional users, simultaneously considering Computer Graphics and Human Computer Interaction design considerations is required. In this position paper, we first provide an overview of a new analytical framework for the design of advanced interaction techniques for 3D Virtual Environment. It consists in identifying links that support the interaction and connect user’s tasks to be performed in a 3DVE with the targeted scene graph. We relate our work to existing modeling approaches and discuss about our expectations with regards to the engineering of advanced interaction techniqu

0230: Effectiveness of switching Prasugrel's ‘low responders’ to ticagrelor after acute coronary syndrome

AimsThis study aimed to assess the effectiveness and safety of switching from Prasugrel to Ticagrelor patients identified as Prasugrel low-responders one month after ACS.Methods and results540 patients admitted for ACS with coronary stent implantation and discharged on Prasugrel 10mg were screened. Prasugrel response was assessed one month after discharge using Platelet Reactivity Index Vasodilatator Stimulated Phosphoprotein (PRI VASP). High on-Treatment Platelet Reactivity (HTPR) was defined as VASP>50%. Patients with HTPR were enrolled and switched to Ticagrelor 90 mg twice a day. They were re-tested a month later. Primary endpoint was defined as: comparison of degree of platelet inhibition and incidence of HTPR one month after switching to Ticagrelor in patients with HTPR on Prasugrel therapy. The safety endpoint was the incidence of bleedings under Ticagrelor as compared with Prasugrel therapy, using the Bleeding Academic Research Consensus definition.Between March 2010 and November 2013, 19 patients were defined as HTPR on Prasugrel 10 mg one month after ACS, with a mean VASP of 59,3%. Among these patients, 14 were switched to Ticagrelor 180 mg daily and, at one month, we observed a significant decrease in PRI VASP, with a mean value at 19.6% (p<0.001). No patients remained HTPR and 4 patients (28.4%) were identified as Very Low on-Treatment Platelet Reactivity (VLTPR) (VASP<10%). No ischemic events were reported after switching, while 3 patients (21%) suffered from bleeding complications (2 BARC1 and 1 BARC2 bleedings) during Ticagrelor therapy.ConclusionSwitch to Ticagrelor in Prasugrel's “low responders” patients is an effective strategy, leading to an adequate platelet inhibition in a large majority of patients. This biological tailored approach could be useful in preventing ischemic complications, in this specific high risk population, potentially increasing bleeding risk. This hypothesis needs to be confirmed in large clinical studies.Abstract 0230 – Figur

Infectious olecranon and patellar bursitis: short-course adjuvant antibiotic therapy is not a risk factor for recurrence in adult hospitalized patients

Objectives No evidence-based recommendations exist for the management of infectious bursitis. We examined epidemiology and risk factors for recurrence of septic bursitis. Specifically, we compared outcome in patients receiving bursectomy plus short-course adjuvant antibiotic therapy (≤7 days) with that of patients receiving bursectomy plus longer-course antibiotic therapy (>7 days). Patients and methods Retrospective study of adult patients with infectious olecranon and patellar bursitis requiring hospitalization at Geneva University Hospital from January 1996 to March 2009. Results We identified 343 episodes of infectious bursitis (237 olecranon and 106 patellar). Staphylococcus aureus predominated among the 256 cases with an identifiable pathogen (85%). Three hundred and twelve cases (91%) were treated surgically; 142 (41%) with one-stage bursectomy and closure and 146 with two-stage bursectomy. All received antibiotics for a median duration of 13 days with a median intravenous component of 3 days. Cure was achieved in 293 (85%) episodes. Total duration of antibiotic therapy [odds ratio (OR) 0.9; 95% confidence interval (95% CI) 0.8-1.1] showed no association with cure. In multivariate analysis, only immunosuppression was linked to recurrence (OR 5.6; 95% CI 1.9-18.4). Compared with ≤7 days, 8-14 days of antibiotic treatment (OR 0.6; 95% CI 0.1-2.9) or >14 days of antibiotic treatment (OR 0.9; 95% CI 0.1-10.7) was equivalent, as was the intravenous component (OR 1.1; 95% CI 1.0-1.3). Conclusions In severe infectious bursitis requiring hospitalization, adjuvant antibiotic therapy might be limited to 7 days in non-immunosuppressed patient