Computing Wasserstein Barycenter via operator splitting: the method of averaged marginals

The Wasserstein barycenter (WB) is an important tool for summarizing sets of probabilities. It finds applications in applied probability, clustering, image processing, etc. When the probability supports are finite and fixed, the problem of computing a WB is formulated as a linear optimization problem whose dimensions generally exceed standard solvers' capabilities. For this reason, the WB problem is often replaced with a simpler nonlinear optimization model constructed via an entropic regularization function so that specialized algorithms can be employed to compute an approximate WB efficiently. Contrary to such a widespread inexact scheme, we propose an exact approach based on the Douglas-Rachford splitting method applied directly to the WB linear optimization problem for applications requiring accurate WB. Our algorithm, which has the interesting interpretation of being built upon averaging marginals, operates series of simple (and exact) projections that can be parallelized and even randomized, making it suitable for large-scale datasets. As a result, our method achieves good performance in terms of speed while still attaining accuracy. Furthermore, the same algorithm can be applied to compute generalized barycenters of sets of measures with different total masses by allowing for mass creation and destruction upon setting an additional parameter. Our contribution to the field lies in the development of an exact and efficient algorithm for computing barycenters, enabling its wider use in practical applications. The approach's mathematical properties are examined, and the method is benchmarked against the state-of-the-art methods on several data sets from the literature

Salinity effects on nutrients uptake, biochemical content and growth response of Blue Panic (Panicum antidotale Retz) and Silage maize (Zea mays L)

Les cultures alternatives tolérantes à la salinité développent des mécanismes complexes dans les conditions biosalines. Nous avons étudié l'effet de l'eau salée sur l'absorption des nutriments et les paramètres physiologiques et biochimiques du bleu panicum (Panicum antidotale Retz) et du maïs d’ensilage (Zea mays L). Des mésocosmes ont été établis en quatre répétitions pour chaque espèce de plante dans une conception orthogonale avec différents niveaux d'eau d'irrigation saline comme traitements donnant T0 = 0.9 dS.m-1 (eau du robinet), T1 = 3 dS m-1, T2 = 6 dS m-1 et T3 = 10 dS m-1, pendant 8 semaines. L'augmentation de la salinité a provoqué un effet dépressif sur le maïs d’ensilage, conduisant à une réduction significative de la croissance (jusqu'à 37%), de la biomasse aérienne sèche (jusqu'à 58%) et racinaire (jusqu'à 87%) par rapport au témoin. Ainsi qu'une diminution de la chlorophylle a (jusqu'à 71 %), de la chlorophylle b (jusqu'à 77 %) et des caroténoïdes (jusqu'à 49 %) par rapport au témoin. Pour le bleu panicum, la salinité n'a par contre pas affecté les paramètres physiologiques et biochimiques étudiés. L'absorption de l’azote, du phosphore, du potassium et du calcium, du maïs d’ensilage a diminué avec l'augmentation des niveaux de salinité pour être significative pour une eau d'irrigation avec une conductivité électrique ≥ 6 dS m-1 par rapport au contrôle. La teneur en sodium dans les différentes parties du maïs d’ensilage (feuille, tige et racine), par contre, a augmenté significativement avec l'augmentation de la salinité. L'accumulation du calcium, du potassium et de l’azote a légèrement augmenté chez le bleu panicum, mais n’était significatif que dans des parties distinctes de la plante. Dans l'ensemble, notre étude indique que le maïs est plus sensible aux conditions salines (notamment celles ≥ 6 dS m-1) par rapport au bleu panicum qui tolère bien un environnement de salinité élevé ≥ 10 dS.m-1. Nos résultats suggèrent ainsi que l'introduction du bleu panicum comme culture alternative sur les sols affectés par la salinité, comme le périmètre irrigué de Foum El Oued à Laâyoune au Maroc, résulterait en des rendements élevés meilleurs que les rendements des cultures traditionnelles comme le maïs d’ensilage et améliorerait donc le revenu des agriculteurs locaux.Saline-tolerant alternative crops develop complex mechanisms under biosaline conditions. We investigated the effect of saline water on nutrient uptake, physiological and biochemical parameters of Blue Panic (Panicum antidotale Retz) and silage maize (Zea mays L). Mesocosms were established in four replicates for each plant species in an orthogonal design with different levels of saline irrigation water as treatments giving T0 = 0.9 dS m-1 (tap water), T1 = 3 dS m -1, T2 = 6 dS m-1 and T3 = 10 dS m-1, for 8 weeks. Increasing salinity caused a depressive effect on silage maize's physiological parameters, leading to a significant decrease in growth (up to 37%), aboveground (up to 58%) and root (up to 87%) dry matter biomass compared to control. As well as a decrease of chlorophyll a (up to 71%), chlorophyll b (up to 77%) and carotenoid (up to 49%) compared to control. For blue panic, salinity did not, however, affect the studied physiological and biochemical parameters. Nitrogen, phosphorus, potassium and calcium uptake, of silage maize, decreased with increasing salinity levels to be significant in irrigation water with electrical conductivity ≥ 6 dS m-1 relative to control. The sodium content in different parts of silage maize (leaf, stem and root), on the other hand, increased significantly with increasing salinity. The accumulation of calcium, potassium and nitrogen increased slightly in the blue panic, but this was only significant in separate parts of the plant. Overall, our study indicates that silage maize is more sensitive to saline conditions (particularly ≥ 6 dS m-1) compared to blue panic which tolerates well high saline environment ≥ 10 dS m-1. Our results, suggest therefore that the introduction of blue panic as an alternative crop on salt affected soils, such as the irrigated perimeter of Foum El Oued in Laâyoune in Morocco, would exhibit high performance better than traditional crops as silage maize and therefore would improve the local farmers’ income

A priori filtering and LES modeling of turbulent two-phase flows application to phase separation

International audienceThe Large Eddy Simulation (LES) of two-phase flows with resolved scale interfaces is investigated through the a priori filtering of Direct Numerical Simulations (DNS) of one-fluid and multifield models. A phase inversion benchmark [ 1 –4] is considered highlighting many coalescence and interface rupture events in a kind of atomization process. The order of magnitude of specific two-phase subgrid LES terms is first considered with the two modeling approaches. Then, different existing models such as Smagorinsky [5], Wall-Adapting Local Eddy-viscosity (WALE) model [6], Bardina [7], Mixed [8] and Approximate Deconvo-lution Model (ADM) [9] are used to account for two-phase subgrid effects. These models are compared to filtered DNS results. The main conclusion concerning a priori LES filtering is that the inertia term is not predominant in two-phase flows with fragmentation and rupture of interface. This conclusion is different from that of the studies of [3, 10–13]. Concerning LES models, functional modeling do not correlate to filtered DNS results whereas structural approaches do. Bardina and ADM are clearly the good LES framework to consider for two-phase flows with resolved scale interfaces. ADM is clearly better than Bardina in our study

Comparison and Uncertainty Quantification of Two-Fluid Models forBubbly Flows with NEPTUNE_CFD and STAR-CCM+

International audienceThe nuclear industry is interested in better understanding the behavior of turbulent boiling flowsand in using modern computational tools for the design and analysis of advanced fuels and reactorsand for simulation and study of mitigation strategies in accident scenarios. Such interests serve asdrivers for the advancement of the 3-dimensional multiphase Computational Fluid Dynamicsapproach. A pair of parallel efforts have been underway in Europe and in the United States, theNEPTUNE and CASL programs respectively, that aim at delivering advanced simulation tools thatwill enable improved safety and economy of operations of the reactor fleet. Results from acollaboration between these two efforts, aimed at advancing the understanding of multiphaseclosures for pressurized water reactor (PWR) application, are presented. Particular attention is paidto the assessment and analysis of the different physical models implemented in NEPTUNE_CFDand STAR-CCM+ codes used in the NEPTUNE and the CASL programs respectively, forapplication to turbulent two-phase bubbly flows. The experiments conducted by Liu and Bankoff(Liu, 1989; Liu and Bankoff 1993a and b) are selected for benchmarking, and predictions from thetwo codes are presented for a broad range of flow conditions and with void fractions varyingbetween 0 and 50percent. Comparison of the CFD simulations and experimental measurements revealsthat a similar level of accuracy is achieved in the two codes. The differences in both sets of closuremodels are analyzed, and their capability to capture the main features of the flow over a wide rangeof experimental conditions are discussed. This analysis paves the way for future improvements ofexisting two-fluid models. The benchmarks are further leveraged for a systematic study of thepropagation of model uncertainties. This provides insights into mechanisms that lead to complexinteractions between individual closures (of the different phenomena) in the multiphase CFDapproach. As such, it is seen that the multi-CFD-code approach and the principled uncertaintyquantification approach are both of great value in assessing the limitations and the level of maturityof multiphase hydrodynamic closures

Gridded global surface ozone metrics for atmospheric chemistry model evaluation

The concentration of ozone at the Earth's surface is measured at many locations across the globe for the purposes of air quality monitoring and atmospheric chemistry research. We have brought together all publicly available surface ozone observations from online databases from the modern era to build a consistent data set for the evaluation of chemical transport and chemistry-climate (Earth System) models for projects such as the Chemistry-Climate Model Initiative and Aer-Chem-MIP. From a total data set of approximately 6600 sites and 500 million hourly observations from 1971-2015, approximately 2200 sites and 200 million hourly observations pass screening as high-quality sites in regionally representative locations that are appropriate for use in global model evaluation. There is generally good data volume since the start of air quality monitoring networks in 1990 through 2013. Ozone observations are biased heavily toward North America and Europe with sparse coverage over the rest of the globe. This data set is made available for the purposes of model evaluation as a set of gridded metrics intended to describe the distribution of ozone concentrations on monthly and annual timescales. Metrics include the moments of the distribution, percentiles, maximum daily 8-hour average (MDA8), sum of means over 35 ppb (daily maximum 8-h; SOMO35), accumulated ozone exposure above a threshold of 40 ppbv (AOT40), and metrics related to air quality regulatory thresholds. Gridded data sets are stored as netCDF-4 files and are available to download from the British Atmospheric Data Centre (doi:10.5285/08fbe63d-fa6d-4a7a-b952-5932e3ab0452). We provide recommendations to the ozone measurement community regarding improving metadata reporting to simplify ongoing and future efforts in working with ozone data from disparate networks in a consistent manner

Supernova Neutrino Spectrum with Matter and Spin Flavor Precession Effects

We consider Majorana neutrino conversions inside supernovae by taking into account both flavor mixing and the neutrino magnetic moment. We study the adiabaticity of various possible transitions between the neutrino states for both normal and inverted hierarchy within the various solar neutrino problem solutions. From the final mass spectrum within diffrent scenarios, we infer the consequences of the various conversion effects on the neutronization peak, the nature of final spectra, and the possible Earth matter effect on the final fluxes. This enable us to check the sensibility of the SN neutrino flux on magnetic moment interaction, and narrow down possible scenarios which depend on: the mass spectrum normal or inverted, the solution of the solar neutrino problem; and the value of MuxB.Comment: 24pages, 7 figure

Familial Mediterranean fever, Inflammation and Nephrotic Syndrome: Fibrillary Glomerulopathy and the M680I Missense Mutation

BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by inflammatory serositis (fever, peritonitis, synovitis and pleuritis). The gene locus responsible for FMF was identified in 1992 and localized to the short arm of chromosome 16. In 1997, a specific FMF gene locus, MEFV, was discovered to encode for a protein, pyrin that mediates inflammation. To date, more than forty missense mutations are known to exist. The diversity of mutations identified has provided insight into the variability of clinical presentation and disease progression. CASE REPORT: We report an individual heterozygous for the M680I gene mutation with a clinical diagnosis of FMF using the Tel-Hashomer criteria. Subsequently, the patient developed nephrotic syndrome with biopsy-confirmed fibrillary glomerulonephritis (FGN). Further diagnostic studies were unremarkable with clinical workup negative for amyloidosis or other secondary causes of nephrotic syndrome. DISCUSSION: Individuals with FMF are at greater risk for developing nephrotic syndrome. The most serious etiology is amyloidosis (AA variant) with renal involvement, ultimately progressing to end-stage renal disease. Other known renal diseases in the FMF population include IgA nephropathy, IgM nephropathy, Henoch-Schönlein purpura as well as polyarteritis nodosa. CONCLUSION: To our knowledge, this is the first association between FMF and the M680I mutation later complicated by nephrotic syndrome and fibrillary glomerulonephritis

Definitions and outcome measures for bullous pemphigoid: Recommendations by an international panel of experts

Our scientific knowledge of bullous pemphigoid (BP) has dramatically progressed in recent years. However, despite the availability of various therapeutic options for the treatment of inflammatory diseases, only a few multicenter controlled trials have helped to define effective therapies in BP. A major obstacle in sharing multicenter-based evidences for therapeutic efforts is the lack of generally accepted definitions for the clinical evaluation of patients with BP. Common terms and end points of BP are needed so that experts in the field can accurately measure and assess disease extent, activity, severity, and therapeutic response, and thus facilitate and advance clinical trials. These recommendations from the International Pemphigoid Committee represent 2 years of collaborative efforts to attain mutually acceptable common definitions for BP and proposes a disease extent score, the BP Disease Area Index. These items should assist in the development of consistent reporting of outcomes in future BP reports and studies. © 2011 by the American Academy of Dermatology, Inc

Cd(II) and Pb(II) complexes of the polyether ionophorous antibiotic salinomycin

<p>Abstract</p> <p>Background</p> <p>The natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in <it>in vivo </it>experiments, despite so far no Pb(II)-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their <it>in vitro </it>complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II) and lead(II).</p> <p>Results</p> <p>New metal(II) complexes of the polyether ionophorous antibiotic salinomycin with Cd(II) and Pb(II) ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa) undergoes a reaction with heavy metal(II) ions to form [Cd(Sal)₂(H₂O)₂] (<b>1</b>) and [Pb(Sal)(NO₃)] (<b>2</b>), respectively. Abstraction of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II) ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield <b>1</b>. Two salinomycin anions occupy the equatorial plane of the Cd(II) center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II) cation. Complex <b>2 </b>consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation.</p> <p>Conclusion</p> <p>The formation of the salinomycin heavy metal(II) complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock farming.</p

The Protease Inhibitor Alpha-2-Macroglobuline-Like-1 Is the p170 Antigen Recognized by Paraneoplastic Pemphigus Autoantibodies in Human

Paraneoplastic pemphigus (PNP) is a devastating autoimmune blistering disease, involving mucocutaneous and internal organs, and associated with underlying neoplasms. PNP is characterized by the production of autoantibodies targeting proteins of the plakin and cadherin families involved in maintenance of cell architecture and tissue cohesion. Nevertheless, the identity of an antigen of Mr 170,000 (p170), thought to be critical in PNP pathogenesis, has remained unknown