Scalable precision wide-field imaging in radio interferometry: I. uSARA validated on ASKAP data

As Part I of a paper series showcasing a new imaging framework, we consider the recently proposed unconstrained Sparsity Averaging Reweighted Analysis (uSARA) optimisation algorithm for wide-field, high-resolution, high-dynamic range, monochromatic intensity imaging. We reconstruct images from real radio-interferometric observations obtained with the Australian Square Kilometre Array Pathfinder (ASKAP) and present these results in comparison to the widely-used, state-of-the-art imager WSClean. Selected fields come from the ASKAP Early Science and Evolutionary Map of the Universe (EMU) Pilot surveys and contain several complex radio sources: the merging cluster system Abell 3391-95, the merging cluster SPT-CL 2023-5535, and many extended, or bent-tail, radio galaxies, including the X-shaped radio galaxy PKS 2014-558 and the ``dancing ghosts'', known collectively as PKS 2130-538. The modern framework behind uSARA utilises parallelisation and automation to solve for the w-effect and efficiently compute the measurement operator, allowing for wide-field reconstruction over the full field-of-view of individual ASKAP beams (up to 3.3 deg each). The precision capability of uSARA produces images with both super-resolution and enhanced sensitivity to diffuse components, surpassing traditional CLEAN algorithms which typically require a compromise between such yields. Our resulting monochromatic uSARA-ASKAP images of the selected data highlight both extended, diffuse emission and compact, filamentary emission at very high resolution (up to 2.2 arcsec), revealing never-before-seen structure. Here we present a validation of our uSARA-ASKAP images by comparing the morphology of reconstructed sources, measurements of diffuse flux, and spectral index maps with those obtained from images made with WSClean.Comment: Accepted for publication in MNRA

Sexual and Reproductive Health Behaviors of Undocumented Migrants in Geneva: A Cross Sectional Study

Undocumented migrants face major barriers in accessing prevention and health care. Whereas the association between low socioeconomic status and poor health is well documented only few studies have addressed specific health issues in undocumented migrants. The aim of the present study is to describe sexual and reproductive health behaviors of undocumented migrants in Geneva. This descriptive cross sectional study included consecutive undocumented migrants presenting from November 2007 to February 2008 to a health facility offering free access to health care to this population. Following informed consent, they completed a self administered questionnaire about their socio-demographic profile and sexual and reproductive health behaviors. A total of 384 patients were eligible for the study. 313 (82%) agreed to participate of which 77% (241 patients) completed the survey. Participants were mainly young, Latino-American, single, well-educated and currently working women. They had multiple partners and reported frequently engaging in sexual intercourse. Use of contraceptive methods and strategies of prevention against sexually transmitted infections (STI) were rare. Nearly half of the women had had at least one induced abortion and 40% had had an unplanned pregnancy. One in four participants reported a current or past STI or other genital infection. The results of our study suggest that undocumented migrants engage in frequent and high risk sexual intercourse with insufficient use of contraceptive methods and suboptimal strategies of prevention against STI. Our study underlines the real need for specific sexual and reproductive educational programs targeting this hard to reach populatio

Scalable precision wide-field imaging in radio interferometry: II. AIRI validated on ASKAP data

Accompanying Part I, this sequel delineates a validation of the recently proposed AI for Regularisation in radio-interferometric Imaging (AIRI) algorithm on observations from the Australian Square Kilometre Array Pathfinder (ASKAP). The monochromatic AIRI-ASKAP images showcased in this work are formed using the same parallelised and automated imaging framework described in Part I: ``uSARA validated on ASKAP data''. Using a Plug-and-Play approach, AIRI differs from uSARA by substituting a trained denoising deep neural network (DNN) for the proximal operator in the regularisation step of the forward-backward algorithm during deconvolution. We build a trained shelf of DNN denoisers which target the estimated image-dynamic-ranges of our selected data. Furthermore, we quantify variations of AIRI reconstructions when selecting the nearest DNN on the shelf versus using a universal DNN with the highest dynamic range, opening the door to a more complete framework that not only delivers image estimation but also quantifies epistemic model uncertainty. We continue our comparative analysis of source structure, diffuse flux measurements, and spectral index maps of selected target sources as imaged by AIRI and the algorithms in Part I -- uSARA and WSClean. Overall we see an improvement over uSARA and WSClean in the reconstruction of diffuse components in AIRI images. The scientific potential delivered by AIRI is evident in further imaging precision, more accurate spectral index maps, and a significant acceleration in deconvolution time, whereby AIRI is four times faster than its sub-iterative sparsity-based counterpart uSARA.Comment: Accepted for publication in MNRA

Tolerance and Safety of Nifurtimox in Patients with Chronic Chagas Disease

Background. Nifurtimox has been used to treat Chagas disease for 40 years, but tolerance and safety data in adults are scarce. We aimed to evaluate nifurtimox tolerance and safety in a cohort of Trypanosoma cruzi-infected adult patients in a country of nonendemicity. Methods. This observational study included all consecutive adults patients who were given a diagnosis of T. cruzi infection from June through December 2008. Eligible patients received nifurtimox at 10 mg/kg/day for 60 days, with regular medical and biological follow-up. Adverse events (AEs) were recorded according to Common Terminology Criteria for Adverse Events, version 3.0. Results. Eighty-one patients received nifurtimox. Eight were lost to follow-up during treatment, and 41 (56.2%) completed the 60-day course. All premature treatment terminations were caused by AEs; 97.5% of patients suffered from AEs, mostly expected (90.5%) and not severe. Gastrointestinal symptoms predominated. Six (7.4%) patients presented with a suspected unexpected serious adverse reaction: drug reaction with eosinophilia and systemic symptoms (n = 3), Quincke edema (n = 1), acute myocarditis (n = 1), and anaphylaxis (n = 1). Patients with 3 or more AEs had an increased risk of premature treatment termination (hazard ratio, 8.42; 95% confidence interval, 1.6-45.5). Conclusion. Nifurtimox is poorly tolerated among adults with chronic Chagas disease, resulting in a low treatment completion rate. Considering the significant risk of serious AEs, close monitoring is required, which may be difficult to implement in poor rural areas of countries of endemicity. The safety and efficacy of nifurtimox and benznidazole should be compared to improve current therapeutic recommendations, and pharmacovigilance systems should be enhance

Exploratory Analysis of Functional Data via Clustering and Optimal Segmentation

We propose in this paper an exploratory analysis algorithm for functional data. The method partitions a set of functions into $K$ clusters and represents each cluster by a simple prototype (e.g., piecewise constant). The total number of segments in the prototypes, $P$, is chosen by the user and optimally distributed among the clusters via two dynamic programming algorithms. The practical relevance of the method is shown on two real world datasets

The Off-Shell Electromagnetic T-matrix: momentum-dependent scattering from spherical inclusions with both dielectric and magnetic contrast

The momentum- and frequency-dependent T-matrix operator for the scattering of electromagnetic waves by a dielectric/conducting and para- or diamagnetic sphere is derived as a Mie-type series, and presented in a compact form emphasizing various symmetry properties, notably the unitarity identity. This result extends to magnetic properties one previously obtained for purely dielectric contrasts by other authors. Several situations useful to spatially-dispersive effective-medium approximations to one-body order are examined. Partial summation of the Mie series is achieved in the case of elastic scattering.Comment: 22 pages. Preprint of a paper to appear in `Waves in Complex And Random Media' ((c) Taylor and Francis, 2011

Congenital Transmission of Chagas Disease in Latin American Immigrants in Switzerland

International migration has changed the epidemiologic patterns of Chagas disease. Recently, 2 cases of Chagas disease transmitted from Latin American women to their newborns were diagnosed in Geneva, Switzerland. A retrospective study to detect Chagas disease showed a prevalence of 9.7% among 72 Latin American women tested during pregnancy in Switzerland

Forward and robust selection of the most potent and noncellular toxic siRNAs from RNAi libraries

Use of highly potent small interfering RNAs (siRNAs) can substantially reduce dose-dependent cytotoxic and off-target effects. We developed a genetic forward approach by fusing the cytosine deaminase gene with targets for the robust identification of highly potent siRNAs from RNA interference (RNAi) libraries that were directly delivered into cells via bacterial invasion. We demonstrated that two simple drug selection cycles performed conveniently in a single container predominately enriched two siRNAs targeting the MVP gene (siMVP) and one siRNA targeting the egfp gene (siEGFP) in surviving cells and these proved to be the most effective siRNAs reported. Furthermore, the potent siRNAs isolated from the surviving cells possessed noncellular toxic characteristics. Interestingly, the length of highly potent siMVPs identified could be as short as 16-mer, and increasing the length of their native sequences dramatically reduced RNAi potency. These results suggest that the current approach can robustly discover the most potent and nontoxic siRNAs in the surviving cells, and thus has great potential in facilitating RNAi applications by minimizing the dose-dependent and sequence nonspecific side effects of siRNAs