Pipeline Implementations of Neumann-Neumann and Dirichlet-Neumann Waveform Relaxation Methods

This paper is concerned with the reformulation of Neumann-Neumann Waveform Relaxation (NNWR) methods and Dirichlet-Neumann Waveform Relaxation (DNWR) methods, a family of parallel space-time approaches to solving time-dependent PDEs. By changing the order of the operations, pipeline-parallel computation of the waveform iterates are possible without changing the final solution. The parallel efficiency and the increased communication cost of the pipeline implementation is presented, along with weak scaling studies to show the effectiveness of the pipeline NNWR and DNWR algorithms.Comment: 20 pages, 8 figure

Schwarz waveform relaxation with adaptive pipelining

Schwarz waveform relaxation (SWR) methods have been developed to solve a wide range of diffusion-dominated and reaction-dominated equations. The appeal of these methods stems primarily from their ability to use nonconforming space-time discretizations; SWR methods are consequently well-adapted for coupling models with highly varying spatial and time scales. The efficacy of SWR methods is questionable, however, since in each iteration, one propagates an error across the entire time interval. In this manuscript, we introduce an adaptive pipeline approach wherein one subdivides the computational domain into space-time blocks, and adaptively selects the waveform iterates which should be updated given a fixed number of computational workers. Our method is complementary to existing space and time parallel methods, and can be used to obtain additional speedup when the saturation point is reached for other types of parallelism. We analyze these waveform relaxation with adaptive pipelining (WRAP) methods to show convergence and the theoretical speedup that can be expected. Numerical experiments on solutions to the linear heat equation, the advection-diffusion equation, and a reaction-diffusion equation illustrate features and efficacy of WRAP methods for various transmission conditions

Bulk crystal growth and electronic characterization of the 3D Dirac Semimetal Na3Bi

High quality hexagon plate-like Na3Bi crystals with large (001) plane surfaces were grown from a molten Na flux. The freshly cleaved crystals were analyzed by low temperature scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), allowing for the characterization of the three-dimensional (3D) Dirac semimetal (TDS) behavior and the observation of the topological surface states. Landau levels (LL) were observed, and the energy-momentum relations exhibited a linear dispersion relationship, characteristic of the 3D TDS nature of Na3Bi. In transport measurements on Na3Bi crystals the linear magnetoresistance and Shubnikov-de Haas (SdH) quantum oscillations are observed for the first time.Comment: To be published in a special issue of APL Material

A Psychometric Comparison of Psychological Inflexibility Measures: Discriminant Validity and Item Performance

Psychological inflexibility is a rigid behavioral pattern that interferes with engagement in personally meaningful activities; it is the hypothesized root of suffering in acceptance and commitment therapy (ACT). Thus, the quality of its measurement affects the research, theory, and practice of ACT. The current study aimed to evaluate the discriminant validity and item performance of four measures of psychological inflexibility: the Acceptance and Action Questionnaire—II (AAQ-II), a revised version of the AAC-II (AAQ-3), the Brief Experiential Avoidance Questionnaire (BEAQ), and the Comprehensive assessment of Acceptance and Commitment Therapy processes (CompACT). We analyzed data from community (n = 253), student (n = 261), and treatment-seeking samples (n = 140) using exploratory factor analysis and multigroup graded-response models. The CompACT had the strongest discriminant validity followed by the AAQ-3, whereas items in the CompACT Behavioral Awareness and Valued Action subscales performed most consistently across groups. No single measure emerged as clearly superior to others; rather, appropriate selection of measures depends on the goals and context of assessment. Scientific and clinical implications are discussed

Notch1 mutations drive clonal expansion in normal esophageal epithelium but impair tumor growth

NOTCH1 mutant clones occupy the majority of normal human esophagus by middle age but are comparatively rare in esophageal cancers, suggesting NOTCH1 mutations drive clonal expansion but impede carcinogenesis. Here we test this hypothesis. Sequencing NOTCH1 mutant clones in aging human esophagus reveals frequent biallelic mutations that block NOTCH1 signaling. In mouse esophagus, heterozygous Notch1 mutation confers a competitive advantage over wild-type cells, an effect enhanced by loss of the second allele. Widespread Notch1 loss alters transcription but has minimal effects on the epithelial structure and cell dynamics. In a carcinogenesis model, Notch1 mutations were less prevalent in tumors than normal epithelium. Deletion of Notch1 reduced tumor growth, an effect recapitulated by anti-NOTCH1 antibody treatment. Notch1 null tumors showed reduced proliferation. We conclude that Notch1 mutations in normal epithelium are beneficial as wild-type Notch1 favors tumor expansion. NOTCH1 blockade may have therapeutic potential in preventing esophageal squamous cancer

A sensual philology for Anglo-Saxon England

What forgotten forms can philology assume anew? Reassessing how early medieval writers loved words differently than we do reveals significant gaps between past and presence senses of the physical phenomena words can index. In the early medieval language of Old English texts there remains a largely uncharted capacity for less linguistically driven aspects of expression, formed through a network of words, sounds, bodies and media: how the mute sound of a bell and the crook of a silent finger come together in medieval sign language, or how the Old English word for ring becomes a weeping, poetic gasp within a heaving breast. Such early medieval moments of communication survive because of language and in spite of language, and qualify the visualist framework through which we predictably reconstitute the medieval past, calling, /sotto voce/, for more than lovely words

Biological, clinical and population relevance of 95 loci for blood lipids.

Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD

Preferences for HIV prevention strategies among newly arrived Asian-born men who have sex with men living in Australia: A discrete choice experiment.

The HIV epidemic in Australia is changing with higher risk for HIV among newly-arrived Asian-born men who have sex with men (MSM) compared to Australian-born MSM. We evaluated the preferences for HIV prevention strategies among 286 Asian-born MSM living in Australia for <5 years. A latent class analysis uncovered three classes of respondents who were defined by their preferences: "PrEP" (52%), "Consistent condoms" (31%), and "No strategy" (17%). Compared to the "No strategy" class, men in the "PrEP" class were less likely to be a student or ask their partner for their HIV status. Men in the "Consistent condoms" class were more likely to get information about HIV from online, and less likely to ask their partner for their HIV status. Overall, PrEP was the preferred HIV prevention strategy for newly arrived migrants. Removing structural barriers to access PrEP can accelerate progress toward ending HIV transmission

A clinical diagnostic model for predicting influenza among young adult military personnel with febrile respiratory illness in Singapore

10.1371/journal.pone.0017468PLoS ONE63