Wavelet-based density estimation for noise reduction in plasma simulations using particles

For given computational resources, the accuracy of plasma simulations using particles is mainly held back by the noise due to limited statistical sampling in the reconstruction of the particle distribution function. A method based on wavelet analysis is proposed and tested to reduce this noise. The method, known as wavelet based density estimation (WBDE), was previously introduced in the statistical literature to estimate probability densities given a finite number of independent measurements. Its novel application to plasma simulations can be viewed as a natural extension of the finite size particles (FSP) approach, with the advantage of estimating more accurately distribution functions that have localized sharp features. The proposed method preserves the moments of the particle distribution function to a good level of accuracy, has no constraints on the dimensionality of the system, does not require an a priori selection of a global smoothing scale, and its able to adapt locally to the smoothness of the density based on the given discrete particle data. Most importantly, the computational cost of the denoising stage is of the same order as one time step of a FSP simulation. The method is compared with a recently proposed proper orthogonal decomposition based method, and it is tested with three particle data sets that involve different levels of collisionality and interaction with external and self-consistent fields

WAVELET REGULARIZATION OF A FOURIER-GALERKIN METHOD FOR SOLVING THE 2D INCOMPRESSIBLE EULER EQUATIONS

International audienceWe employ a Fourier-Galerkin method to solve the 2D incompressible Euler equations, and study several ways to regularize the solution by wavelet filtering at each timestep. Real-valued orthogonal wavelets and complex-valued wavelets are considered, combined with either linear or non-linear filtering. The results are compared with those obtained via classical viscous and hyperviscous regularization methods. Wavelet regularization using complex-valued wavelets performs as well in terms of L2 convergence rate to the reference solution. The compression rate for homogeneous 2D turbulence is around 3 for this method, suggesting that memory and CPU time could be reduced in an adaptive wavelet computation. Our results also suggest L2 convergence to the reference solution without any regularization, in contrast to what is obtained for the 1D Burgers equation

Phosducin regulates the expression of transducin betagamma subunits in rod photoreceptors and does not contribute to phototransduction adaptation.

For over a decade, phosducin's interaction with the betagamma subunits of the G protein, transducin, has been thought to contribute to light adaptation by dynamically controlling the amount of transducin heterotrimer available for activation by photoexcited rhodopsin. In this study we directly tested this hypothesis by characterizing the dark- and light-adapted response properties of phosducin knockout (Pd- / -) rods. Pd- / - rods were notably less sensitive to light than wild-type (WT) rods. The gain of transduction, as measured by the amplification constant using the Lamb-Pugh model of activation, was 32% lower in Pd- / - rods than in WT rods. This reduced amplification correlated with a 36% reduction in the level of transducin betagamma-subunit expression, and thus available heterotrimer in Pd- / - rods. However, commonly studied forms of light adaptation were normal in the absence of phosducin. Thus, phosducin does not appear to contribute to adaptation mechanisms of the outer segment by dynamically controlling heterotrimer availability, but rather is necessary for maintaining normal transducin expression and therefore normal flash sensitivity in rods

Depth, balancing, and limits of the Elo model

-Much work has been devoted to the computational complexity of games. However, they are not necessarily relevant for estimating the complexity in human terms. Therefore, human-centered measures have been proposed, e.g. the depth. This paper discusses the depth of various games, extends it to a continuous measure. We provide new depth results and present tool (given-first-move, pie rule, size extension) for increasing it. We also use these measures for analyzing games and opening moves in Y, NoGo, Killall Go, and the effect of pie rules

Extraction of a tricarboxylic acid from a sugar-cane by-product – Study and modeling of the anion-exchange step

Extraction of a tricarboxylic acid from a sugar-cane by-product – Study and modeling of the anion-exchange step . 16. Congrès de la Société Française de Génie des Procédés "Le Génie des Procédés au Service de l'Homme" (SFGP 2017

SOCIAL BEHAVIOUR AND ITS EVOLUTION IN SCYTODID SPIDERS (ARANEAE: SCYTODIDAE)

Ph.DDOCTOR OF PHILOSOPH

Genetic affinities between the Yami tribe people of Orchid Island and the Philippine Islanders of the Batanes archipelago

<p>Abstract</p> <p>Background</p> <p>Yami and Ivatan islanders are Austronesian speakers from Orchid Island and the Batanes archipelago that are located between Taiwan and the Philippines. The paternal genealogies of the Yami tribe from 1962 monograph of Wei and Liu were compared with our dataset of non-recombining Y (NRY) chromosomes from the corresponding families. Then mitochondrial DNA polymorphism was also analyzed to determine the matrilineal relationships between Yami, Ivatan, and other East Asian populations.</p> <p>Results</p> <p>The family relationships inferred from the NRY Phylogeny suggested a low number of paternal founders and agreed with the genealogy of Wei and Liu (P < 0.01). Except for one Y short tandem repeat lineage (Y-STR), seen in two unrelated Yami families, no other Y-STR lineages were shared between villages, whereas mtDNA haplotypes were indiscriminately distributed throughout Orchid Island.</p> <p>The genetic affinity seen between Yami and Taiwanese aborigines or between Ivatan and the Philippine people was closer than that between Yami and Ivatan, suggesting that the Orchid islanders were colonized separately by their nearest neighbors and bred in isolation. However a northward gene flow to Orchid Island from the Philippines was suspected as Yami and Ivatan peoples both speak Western Malayo-Polynesian languages which are not spoken in Taiwan. Actually, only very little gene flow was observed between Yami and Ivatan or between Yami and the Philippines as indicated by the sharing of mtDNA haplogroup B4a1a4 and one O1a1* Y-STR lineage.</p> <p>Conclusions</p> <p>The NRY and mtDNA genetic information among Yami tribe peoples fitted well the patrilocal society model proposed by Wei and Liu. In this proposal, there were likely few genetic exchanges among Yami and the Philippine people. Trading activities may have contributed to the diffusion of Malayo-Polynesian languages among them.</p> <p>Finally, artifacts dating 4,000 YBP, found on Orchid Island and indicating association with the Out of Taiwan hypothesis might be related to a pioneering stage of settlement, as most dating estimates inferred from DNA variation in our data set ranged between 100-3,000 YBP.</p

Does Pictorial Health Information Improve Health Behaviours and Other Outcomes? A Systematic Review Protocol

Introduction: Most health information is verbal or written, yet words alone may not be the most effective way to communicate health information. Lower health literacy is prevalent in the US and is linked to limited understanding of one’s medical condition and treatment. Pictures increase comprehension, recall, adherence and attention in health settings. This is called pictorial superiority. No systematic review has examined the impact of pictorial health information among patients and consumers, including those with lower health literacy. Methods and analysis: This systematic review and meta-analysis will assess the characteristics and effectiveness of pictorial health information on patient and consumer health behaviours and outcomes, as well as differentially among individuals of lower literacy/lower health literacy. We will conduct a systematic search across selected databases, as well as grey literature, from inception until June 2018. We will include randomised controlled trials in all languages with all types of participants that assess the effect of pictorial health information on patients’ and consumers’ health behaviours and outcomes. Two independent reviewers will conduct the primary screening of articles and data extraction for the selected articles with a third individual available to resolve conflicts. We will assess the quality of all included studies using the Cochrane risk of bias tool. We will combine all selected studies and do a test of heterogeneity. If there is sufficient homogeneity, we will pool studies into a meta-analysis. Independent of the heterogeneity of included studies, we will also conduct a narrative synthesis. Ethics and dissemination: No ethics approval is required. The results will be published in a peer-reviewed journal and presented at relevant conferences