Multilevel Double Loop Monte Carlo and Stochastic Collocation Methods with Importance Sampling for Bayesian Optimal Experimental Design

An optimal experimental set-up maximizes the value of data for statistical inferences and predictions. The efficiency of strategies for finding optimal experimental set-ups is particularly important for experiments that are time-consuming or expensive to perform. For instance, in the situation when the experiments are modeled by Partial Differential Equations (PDEs), multilevel methods have been proven to dramatically reduce the computational complexity of their single-level counterparts when estimating expected values. For a setting where PDEs can model experiments, we propose two multilevel methods for estimating a popular design criterion known as the expected information gain in simulation-based Bayesian optimal experimental design. The expected information gain criterion is of a nested expectation form, and only a handful of multilevel methods have been proposed for problems of such form. We propose a Multilevel Double Loop Monte Carlo (MLDLMC), which is a multilevel strategy with Double Loop Monte Carlo (DLMC), and a Multilevel Double Loop Stochastic Collocation (MLDLSC), which performs a high-dimensional integration by deterministic quadrature on sparse grids. For both methods, the Laplace approximation is used for importance sampling that significantly reduces the computational work of estimating inner expectations. The optimal values of the method parameters are determined by minimizing the average computational work, subject to satisfying the desired error tolerance. The computational efficiencies of the methods are demonstrated by estimating the expected information gain for Bayesian inference of the fiber orientation in composite laminate materials from an electrical impedance tomography experiment. MLDLSC performs better than MLDLMC when the regularity of the quantity of interest, with respect to the additive noise and the unknown parameters, can be exploited

Carcinomes nasopharynges localement avances

Les carcinomes nasopharyngés représentent une entité spécifique différente des cancers de la tête et du cou. L’incidence est plus élevée en Asie du Sud-Est et en Afrique du Nord. Le pronostic reste sombre pour les stades localement avancés (IIB—IVB), plus d’un tiers des cas présenteront une récidive locale et/ou métastatique, la survie globale à cinq ans tous stades confondus est estimée à 50—70 %. L’objectif de ce travail est de préciser les aspects cliniques, diagnostiques, thérapeutiques et pronostiques chez 100 malades porteur de carcinome nasopharyngé localement avancé traités à l’Institut Salah Azaiz (ISA) et de préciser l’impact de la chimiothérapie neoadjuvante (CNA) ainsi que les séquelles thérapeutiques à court et à long terme.Mots clés : carcinome nasopharyngé - chimiothérapie - radiothérapieNasopharyngeal carcinoma represents a specific entity different from cancers of head and neck. The incidence is highest in South- East Asia and North Africa. The prognosis remains poor for locally advanced stages (IIB -IVB), more than one third of cases presented locally recurrent and / or metastatic disease, the overall five-year survival for all stages is estimated at 50-70%. The objective of this study is to clarify the impact of neoadjuvant chemotherapy on long-term survival among 100 patients treated in Institut of Salah Azaiz by neo adjuvant chemotherapy followed by locoregional radiotherapy for locally advanced nasopharyngeal carcinoma, and identify prognostic factors and clinical long term effect.Key words: nasopharyngeal carcinoma – chemotherapy - radiotherap

Heat transfer and pressure drop characteristics of a plate heat exchanger using water based Al2O3 nanofluid for 30° and 60° chevron angles

Nanofluid is a new class of engineering fluid that has good heat transfer characteristics which is essential to increase the heat transfer performance in various engineering applications such as heat exchangers and cooling of electronics. In this study, experiments were conducted to compare the heat transfer performance and pressure drop characteristics in a plate heat exchanger (PHE) for 30° and 60° chevron angles using water based Al2O3 nanofluid at the concentrations from 0 to 0.5 vol.% for different Reynolds numbers. The thermo-physical properties has been determined and presented in this paper. At 0.5 vol% concentration, the maximum heat transfer coefficient, the overall heat transfer coefficient and the heat transfer rate for 60° chevron angle have attained a higher percentage of 15.14%, 7.8% and 15.4%, respectively in comparison with the base fluid. Consequently, when the volume concentration or Reynolds number increases, the heat transfer coefficient and the overall heat transfer coefficient as well as the heat transfer rate of the PHE (Plate Heat Exchangers) increases respectively. Similarly, the pressure drop increases with the volume concentration. 60° chevron angle showed better performance in comparison with 30° chevron angle

Postprocessing for quantum random number generators: entropy evaluation and randomness extraction

Quantum random-number generators (QRNGs) can offer a means to generate information-theoretically provable random numbers, in principle. In practice, unfortunately, the quantum randomness is inevitably mixed with classical randomness due to classical noises. To distill this quantum randomness, one needs to quantify the randomness of the source and apply a randomness extractor. Here, we propose a generic framework for evaluating quantum randomness of real-life QRNGs by min-entropy, and apply it to two different existing quantum random-number systems in the literature. Moreover, we provide a guideline of QRNG data postprocessing for which we implement two information-theoretically provable randomness extractors: Toeplitz-hashing extractor and Trevisan's extractor.Comment: 13 pages, 2 figure

Analyzing Recent Coronary Heart Disease Mortality Trends in Tunisia between 1997 and 2009.

BACKGROUND: In Tunisia, Cardiovascular Diseases are the leading causes of death (30%), 70% of those are coronary heart disease (CHD) deaths and population studies have demonstrated that major risk factor levels are increasing. OBJECTIVE: To explain recent CHD trends in Tunisia between 1997 and 2009. METHODS: DATA SOURCES: Published and unpublished data were identified by extensive searches, complemented with specifically designed surveys. ANALYSIS: Data were integrated and analyzed using the previously validated IMPACT CHD policy model. Data items included: (i)number of CHD patients in specific groups (including acute coronary syndromes, congestive heart failure and chronic angina)(ii) uptake of specific medical and surgical treatments, and(iii) population trends in major cardiovascular risk factors (smoking, total cholesterol, systolic blood pressure (SBP), body mass index (BMI), diabetes and physical inactivity). RESULTS: CHD mortality rates increased by 11.8% for men and 23.8% for women, resulting in 680 additional CHD deaths in 2009 compared with the 1997 baseline, after adjusting for population change. Almost all (98%) of this rise was explained by risk factor increases, though men and women differed. A large rise in total cholesterol level in men (0.73 mmol/L) generated 440 additional deaths. In women, a fall (-0.43 mmol/L), apparently avoided about 95 deaths. For SBP a rise in men (4 mmHg) generated 270 additional deaths. In women, a 2 mmHg fall avoided 65 deaths. BMI and diabetes increased substantially resulting respectively in 105 and 75 additional deaths. Increased treatment uptake prevented about 450 deaths in 2009. The most important contributions came from secondary prevention following Acute Myocardial Infarction (AMI) (95 fewer deaths), initial AMI treatments (90), antihypertensive medications (80) and unstable angina (75). CONCLUSIONS: Recent trends in CHD mortality mainly reflected increases in major modifiable risk factors, notably SBP and cholesterol, BMI and diabetes. Current prevention strategies are mainly focused on treatments but should become more comprehensive

Pixantrone can be activated by formaldehyde to generate a potent DNA adduct forming agent

Mitoxantrone is an anti-cancer agent used in the treatment of breast and prostate cancers. It is classified as a topoisomerase II poison, however can also be activated by formaldehyde to generate drug–DNA adducts. Despite identification of this novel form of mitoxantrone–DNA interaction, excessively high, biologically irrelevant drug concentrations are necessary to generate adducts. A search for mitoxantrone analogues that could potentially undergo this reaction with DNA more efficiently identified Pixantrone as an ideal candidate. An in vitro crosslinking assay demonstrated that Pixantrone is efficiently activated by formaldehyde to generate covalent drug–DNA adducts capable of stabilizing double-stranded DNA in denaturing conditions. Pixantrone–DNA adduct formation is both concentration and time dependent and the reaction exhibits an absolute requirement for formaldehyde. In a direct comparison with mitoxantrone–DNA adduct formation, Pixantrone exhibited a 10- to 100-fold greater propensity to generate adducts at equimolar formaldehyde and drug concentrations. Pixantrone–DNA adducts are thermally and temporally labile, yet they exhibit a greater thermal midpoint temperature and an extended half-life at 37°C when compared to mitoxantrone–DNA adducts. Unlike mitoxantrone, this enhanced stability, coupled with a greater propensity to form covalent drug–DNA adducts, may endow formaldehyde-activated Pixantrone with the attributes required for Pixantrone–DNA adducts to be biologically active

dbVar structural variant cluster set for data analysis and variant comparison

dbVar houses over 3 million submitted structural variants (SSV) from 120 human studies including copy number variations (CNV), insertions, deletions, inversions, translocations, and complex chromosomal rearrangements. Users can submit multiple SSVs to dbVAR that are presumably identical, but were ascertained by different platforms and samples, to calculate whether the variant is rare or common in the population and allow for cross validation. However, because SSV genomic location reporting can vary – including fuzzy locations where the start and/or end points are not precisely known – analysis, comparison, annotation, and reporting of SSVs across studies can be difficult. This project was initiated by the Structural Variant Comparison Group for the purpose of generating a non-redundant set of genomic regions defined by counts of concordance for all human SSVs placed on RefSeq assembly GRCh38 (RefSeq accession GCF_000001405.26). We intend that the availability of these regions, called structural variant clusters (SVCs), will facilitate the analysis, annotation, and exchange of SV data and allow for simplified display in genomic sequence viewers for improved variant interpretation. Sets of SVCs were generated by variant type for each of the 120 studies as well as for a combined set across all studies. Starting from 3.64 million SSVs, 2.5 million and 3.4 million non-redundant SVCs with count \u3e=1 were generated by variant type for each study and across all studies, respectively. In addition, we have developed utilities for annotating, searching, and filtering SVC data in GVF format for computing summary statistics, exporting data for genomic viewers, and annotating the SVC using external data sources

Pomological and Olive Oil Quality Characteristics Evaluation under Short Time Irrigation of Olive Trees cv. Chemlali with Untreated Industrial Poultry Wastewater

The aim of this work was the investigation of the effect of wastewater generated from the poultry meat industry on the irrigation of olive trees, during a short time period, in order to evaluate its impact on pomological criteria and olive oil quality. Olive trees were subjected to irrigation with different water qualities: (i) poultry wastewater (PWW), (ii) poultry wastewater diluted with tap water 50:50 (v/v) (PWTWW), (iii) rain-fed cultivation system (control). The results showed that PWTWW contains the optimal mineral proportions, leading to improved pomological criteria. However, the highest significant pulp oil content was obtained using poultry wastewater irrigation (69.51%), while this was 66.71% using diluted poultry wastewater, and 58.03 % for the control. Poultry wastewater irrigation yielded the best results in oil standard quality indices. In addition, an enrichment in oil total polyphenols content was achieved. The oil fatty acid profile was not affected following irrigation with poultry wastewater. Nevertheless, there was a significant increase in the contents of oleic acid and alcohols, accompanied by a decrease in total sterols. However, heavy metals accumulation was observed in both fruits and olive oil. In conclusion, our results suggest that among the three water qualities, poultry wastewater is the best alternative to improve olive oil quality

Premature mortality attributable to smoking among Tunisian men in 2009

INTRODUCTION: Tobacco smoking is a significant public health threat in the world, a risk factor for many diseases, and has been increasing in prevalence in many developing countries. In this study, we aimed to estimate the burden of premature deaths attributable to smoking among Tunisian men aged 35-69 years in 2009. METHODS: The number of deaths attributable to smoking was estimated using the population attributable risk fraction method. Smoking prevalence was obtained from a nationally representative survey. Causes of death were obtained from the registry of the National Public Health Institute. Relative risks were taken from the American Cancer Society Prevention Study (CPS-II). RESULTS: Total estimated premature deaths attributable to smoking among men in Tunisia were 2601 (95% CI: 2268-2877), accounting for 25% (95% CI: 23.3-26.6) of total male adult mortality. Cancer, cardiovascular and respiratory diseases were the major causes of premature deaths attributable to smoking with 1272 (95% CI: 1188-1329), 966 (95% CI: 779-1133) and 364 (300-415) deaths, respectively. CONCLUSIONS: Tobacco smoking is highly relevant and is related to substantial premature mortality in Tunisia, around double that estimated for the region as a whole. This also has not decreased over the past 20 years. Urgent actions are needed to reduce this pandemic

Plasmocytome Ganglionnaire A Propos D\'un Cas

Les plasmocytomes ganglionnaires sont très rares. Ils peuvent être en rapport avec des métastases à partir d\'un myélome multiple ou d\'un plasmocytome extramédullaire. Les localisations primaires ganglionnaires restent exceptionnelles. Nous rapportons un cas colligé et opéré au service d\'ORL et CMF de l\'hôpital la Rabta. Il s\'agit d\'une femme de 74 ans opérée d\'une tuméfaction submandibulaire gauche. Le diagnostic est fait à l\'examen histologique qui a révélé un plasmocytome ganglionnaire primaire. Le traitement est radiochirurgical. Nous présentons les aspects histopatologiques, cliniques, biologiques et thérapeuthiques de cette affection rare. Keywords: plasmocytomes ganglionnaires, adénopathie cervicale. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 53-5