Searching for faint companions with VLTI/PIONIER. II. 92 main sequence stars from the Exozodi survey

The Exozodi survey aims to determine the occurrence rate of bright exozodiacal discs around nearby main sequence stars using infrared interferometry. Although the Exozodi survey targets have been carefully selected to avoid the presence of binary stars, the results of this survey can still be biased by the presence of unidentified stellar companions. Using the PIONIER data set collected within the Exozodi survey, we aim to search for the signature of point-like companions around the Exozodi target stars. We use both the closure phases and squared visibilities collected by PIONIER to search for companions within the ~100 mas interferometric field of view. The presence of a companion is assessed by computing the goodness of fit to the data for a series of binary models with various separations and contrasts. Five stellar companions are resolved for the first time around five A-type stars: HD 4150, HD 16555, HD 29388, HD 202730, and HD 224392 (although the companion to HD 16555 was independently resolved by speckle interferometry while we were carrying out the survey). In the most likely case of main sequence companions, their spectral types range from A5V to K4V. Three of these stars were already suspected to be binaries from Hipparcos astrometric measurements, although no information was available on the companions themselves so far. In addition to debiasing the statistics of the Exozodi survey, these results can also be used to revise the fraction of visual binaries among A-type stars, suggesting that an extra ~13% A-type stars are visual binaries in addition to the ones detected in previous direct imaging surveys. We estimate that about half the population of nearby A-type stars could be resolved as visual binaries using a combination of state-of-the-art interferometry and single-aperture imaging, and we suggest that a significant fraction of these binaries remains undetected to date.Comment: Accepted for publication in A&

A near-infrared interferometric survey of debris-disc stars. IV. An unbiased sample of 92 southern stars observed in H-band with VLTI/PIONIER

Context. Detecting and characterizing circumstellar dust is a way to study the architecture and evolution of planetary systems. Cold dust in debris disks only traces the outer regions. Warm and hot exozodiacal dust needs to be studied in order to trace regions close to the habitable zone. Aims. We aim to determine the prevalence and to constrain the properties of hot exozodiacal dust around nearby main-sequence stars. Methods. We search a magnitude limited (H < 5) sample of 92 stars for bright exozodiacal dust using our VLTI visitor instrument PIONIER in the H-band. We derive statistics of the detection rate with respect to parameters such as the stellar spectral type and age or the presence of a debris disk in the outer regions of the systems. We derive more robust statistics by combining our sample with the results from our CHARA/FLUOR survey in the K-band. In addition, our spectrally dispersed data allows us to put constraints on the emission mechanism and the dust properties in the detected systems. Results. We find an over-all detection rate of bright exozodiacal dust in the H-band of 11% (9 out of 85 targets) and three tentative detections. The detection rate decreases from early type to late type stars and increases with the age of the host star. We do not confirm the tentative correlation between the presence of cold and hot dust found in our earlier analysis of the FLUOR sample alone. Our spectrally dispersed data suggest that either the dust is extremely hot or the emission is dominated by the scattered light in most cases. The implications of our results for the target selection of future terrestrial planet finding missions using direct imaging are discussed.Comment: 20 pages, 16 figures, 4 tables, updated references and minor changes to the text, accepted for publication in A&

An Unbiased Near-infrared Interferometric Survey for Hot Exozodiacal Dust

Exozodiacal dust is warm or hot dust found in the inner regions of planetary systems orbiting main sequence stars, in or around their habitable zones. The dust can be the most luminous component of extrasolar planetary systems, but predominantly emits in the near- to mid-infrared where it is outshone by the host star. Interferometry provides a unique method of separating this dusty emission from the stellar emission. The visitor instrument PIONIER at the Very Large Telescope Interferometer (VLTI) has been used to search for hot exozodiacal dust around a large sample of nearby main sequence stars. The results of this survey are summarised: 9 out of 85 stars show excess exozodiacal emission over the stellar photospheric emission.Comment: Invited review of our paper (Ertel et al., 2014) for ESO's The Messenger, issue 159. Final version as published in The Messenge

Dietary exposure to pesticide residues and associated health risks in infants and young children – Results of the French infant total diet study

A total diet study (TDS) was undertaken to estimate the chronic dietary exposure to pesticide residues and health risks for the French infants and young children below 3 years old. As a whole, 516 pesticides and metabolites were analysed in 309 food composite samples including 219 manufactured baby foods and 90 common foods, which cover 97% of infants and young children's diet. These composite samples were prepared using 5,484 food products purchased during all seasons from 2011 to 2012 and processed as consumed. Pesticide residues were detected in 67% of the samples and quantified in 27% of the baby food samples and in 60% of the common foods. Seventy-eight different pesticides were detected and 37 of these quantified at levels ranging from 0.02 to 594 µg/kg. The most frequently detected pesticides (greater than 5% samples) were (1) the fungicides 2-phenylphenol, azoxystrobin, boscalid, captan and its metabolite tetrahydrophthalimide, carbendazim, cyprodinil, difenoconazole, dodine, imazalil, metalaxyl, tebuconazole, thiabendazole, (2) the insecticides acetamiprid, pirimiphos-methyl and thiacloprid, (3) the herbicide metribuzin and (4) the synergist piperonyl butoxide. Dietary intakes were estimated for each of the 705 individuals studied and for 431 pesticides incl. 281 with a toxicological reference value (TRV). In the lower-bound scenario, which tends to underestimate the exposure, the TRV were never exceeded. In the upper-bound scenario that overestimates exposure, the estimated intakes exceeded the TRV for dieldrin and lindane (two persistent organic pollutants) and propylene thiourea, a metabolite of propineb. For these three substances, more sensitive analyses are needed to refine the assessment. For 17 other detected and/or prioritised pesticides, the risk could not be characterised due to the lack of a valid TRV, of certain food analyses or the absence of analytical standards for their metabolites. Keywords: Food safety, Infants and young children, Pesticide residues, Total diet study, Exposure assessment, Risk characterizatio

How a supply‐side intervention can help to increase caesarean section rates in Burkina Faso facilities—Evidence from an interrupted time‐series analysis using routine health data

Objectives: In Burkina Faso, only 2.1% of women give birth by caesarean section (CS). To improve the use of maternal health services during pregnancy and childbirth, many interventions were implemented during the 2010s including performance‐based financing (PBF) and a free maternal health care policy (the gratuité). The objective of this study is to evaluate the impact of a supply‐side intervention (PBF) combined with a demand‐side intervention (gratuité) on institutional CS rates in Burkina Faso. Methods: We used routine health data from all the public health facilities in 21 districts (10 that implemented PBF and 11 that did not) from January 2013 to September 2017. We analysed CS rates as the proportion of CS performed out of all facility‐based deliveries (FBD) that occurred in the district. We performed an interrupted time series (ITS) analysis to evaluate the impact of PBF alone and then in conjunction with the gratuité on institutional CS rates. Results: CS rates in Burkina Faso increased slightly between January 2013 and September 2017 in all districts. After the introduction of PBF, the increase of CS rates was higher in intervention than in non‐intervention districts. However, after the introduction of the gratuité, CS rates decreased in all districts, independently of the PBF intervention. Conclusion: In 2017, despite high FBD rates in Burkina Faso as well as the PBF intervention and the gratuité, less than 3% of women who gave birth in a health facility did so by CS. Our study shows that the positive PBF effects were not sustained in a context of user fee exemption

How a supply‐side intervention can help to increase caesarean section rates in Burkina Faso facilities—Evidence from an interrupted time‐series analysis using routine health data

Objectives: In Burkina Faso, only 2.1% of women give birth by caesarean section (CS). To improve the use of maternal health services during pregnancy and childbirth, many interventions were implemented during the 2010s including performance-based financing (PBF) and a free maternal health care policy (the gratuité). The objective of this study is to evaluate the impact of a supply-side intervention (PBF) combined with a demand-side intervention (gratuité) on institutional CS rates in Burkina Faso. Methods: We used routine health data from all the public health facilities in 21 districts (10 that implemented PBF and 11 that did not) from January 2013 to September 2017. We analysed CS rates as the proportion of CS performed out of all facility-based deliveries (FBD) that occurred in the district. We performed an interrupted time series (ITS) analysis to evaluate the impact of PBF alone and then in conjunction with the gratuité on institutional CS rates. Results: CS rates in Burkina Faso increased slightly between January 2013 and September 2017 in all districts. After the introduction of PBF, the increase of CS rates was higher in intervention than in non-intervention districts. However, after the introduction of the gratuité, CS rates decreased in all districts, independently of the PBF intervention. Conclusion: In 2017, despite high FBD rates in Burkina Faso as well as the PBF intervention and the gratuité, less than 3% of women who gave birth in a health facility did so by CS. Our study shows that the positive PBF effects were not sustained in a context of user fee exemption

Clinical Outcomes and Complications After Pedicle-anchored Dynamic or Hybrid Lumbar Spine Stabilization : A Systematic Literature Review

Fusion is the standard in-strumentation for many pathologies of the lumbar spine. Wor-rying rates of failure, including adjacent segment degeneration (ASD), have consistently been reported. The interest for dy-namic stabilization came from the need of minimizing the long-term complications related to the restriction of the lumbar motion. However, pedicle-based dynamic stabilization advan-tages and drawbacks remain controversial

How a supply-side intervention can help to increase caesarean section rates in Burkina Faso facilities-Evidence from an interrupted time-series analysis using routine health data.

OBJECTIVES: In Burkina Faso, only 2.1% of women give birth by caesarean section (CS). To improve the use of maternal health services during pregnancy and childbirth, many interventions were implemented during the 2010s including performance-based financing (PBF) and a free maternal health care policy (the gratuité). The objective of this study is to evaluate the impact of a supply-side intervention (PBF) combined with a demand-side intervention (gratuité) on institutional CS rates in Burkina Faso. METHODS: We used routine health data from all the public health facilities in 21 districts (10 that implemented PBF and 11 that did not) from January 2013 to September 2017. We analysed CS rates as the proportion of CS performed out of all facility-based deliveries (FBD) that occurred in the district. We performed an interrupted time series (ITS) analysis to evaluate the impact of PBF alone and then in conjunction with the gratuité on institutional CS rates. RESULTS: CS rates in Burkina Faso increased slightly between January 2013 and September 2017 in all districts. After the introduction of PBF, the increase of CS rates was higher in intervention than in non-intervention districts. However, after the introduction of the gratuité, CS rates decreased in all districts, independently of the PBF intervention. CONCLUSION: In 2017, despite high FBD rates in Burkina Faso as well as the PBF intervention and the gratuité, less than 3% of women who gave birth in a health facility did so by CS. Our study shows that the positive PBF effects were not sustained in a context of user fee exemption

Leveraging the Variability of Pharmacovigilance Disproportionality Analyses to Improve Signal Detection Performances

Background: A plethora of methods and models of disproportionality analyses for safety surveillance have been developed to date without consensus nor a gold standard, leading to methodological heterogeneity and substantial variability in results. We hypothesized that this variability is inversely correlated to the robustness of a signal of disproportionate reporting (SDR) and could be used to improve signal detection performances. Methods: We used a validated reference set containing 399 true and false drug-event pairs and performed, with a frequentist and a Bayesian disproportionality method, seven types of analyses (model) for which the results were very unlikely to be related to actual differences in absolute risks of ADR. We calculated sensitivity, specificity and plotted ROC curves for each model. We then evaluated the predictive capacities of all models and assessed the impact of combining such models with the number of positive SDR for a given drug-event pair through binomial regression models. Results: We found considerable variability in disproportionality analysis results, both positive and negative SDR could be generated for 60% of all drug-event pairs depending on the model used whatever their truthfulness. Furthermore, using the number of positive SDR for a given drug-event pair largely improved the signal detection performances of all models. Conclusion: We therefore advocate for the pre-registration of protocols and the presentation of a set of secondary and sensitivity analyses instead of a unique result to avoid selective outcome reporting and because variability in the results may reflect the likelihood of a signal being a true adverse drug reaction.MIAI @ Grenoble Alpe

Implicit complexity for coinductive data: a characterization of corecurrence

We propose a framework for reasoning about programs that manipulate coinductive data as well as inductive data. Our approach is based on using equational programs, which support a seamless combination of computation and reasoning, and using productivity (fairness) as the fundamental assertion, rather than bi-simulation. The latter is expressible in terms of the former. As an application to this framework, we give an implicit characterization of corecurrence: a function is definable using corecurrence iff its productivity is provable using coinduction for formulas in which data-predicates do not occur negatively. This is an analog, albeit in weaker form, of a characterization of recurrence (i.e. primitive recursion) in [Leivant, Unipolar induction, TCS 318, 2004].Comment: In Proceedings DICE 2011, arXiv:1201.034