Perturbation Theory vs Simulation: Quasi-linear Scale, Binning Effect, and Visualization of Bispectrum

Recently, Perturbation Theory (PT), specifically the Effective Field Theory of Large Scale Structure (EFTofLSS) and its equivalents, have proven powerful in analyzing observational data. To further this pursuit, we present a quantitative analysis for the accuracy of PT modeling by comparing its analytical prediction to the result from a suite of Quijote simulations. Specifically, we determine $k_{\rm NL}$, the wavenunmber below which the analytical prediction matches well with the N-body result, for both leading order (LO) and next-to-leading order (NLO) power spectrum and bispectrum at redshifts $z=0$, $0.5$, $1$, $2$, $3$. We also quantify the binning effect in Fourier space and show that an appropriate correction must be applied to the analytic predictions in order to compare them with the discrete Fourier transform results obtained from N-body-simulation or real data. Finally, we have devised a novel spherical-Bispectrum visualization scheme fully capturing the scale and configuration dependences. The new scheme facilitates bispectrum-amplitude comparison, for example, between theory and N-body results.Comment: 13 pages, 9 figures, submitted to MNRA

Distancing All Around: Post-Ming China Realpolitik in Seventeenth-Century Korea

During the Ming-Qing transition period, Chosŏn Korea (1392–1910) tried to articulate geopolitical change on its own terms by prioritizing state security. The way the Chosŏn court and ruling elites responded to the Revolt of Wu Sangui (1673–1681) and its aftereffects offers a snapshot of their accommodationist strategy for survival. This article explores how the court and elites maintained a policy of noninvolvement in association with domestic stability for social integration and self-strengthening for border defense. The author reveals the way the Chosŏn court and ruling elites handled the ongoing unexpected situations caused by Qing China, the anti-Qing force, and the Mongols. This approach helps contextualize the links between the realpolitik of Chosŏn and the longue durée of Pax Manjurica, Pax Mongolica, and Pax Sinica and promotes further inquiry into the international relations of East Asia from a transhistorical perspective. Keywords: Chosŏn-Ming alliance, Ming loyalism, Mongols, realpolitik, Revolt of Wu Sangui, state security, Qing dynast

Accelerated Life Testing to Predict Service Life and Reliability for an Appliance Door Hinge

Appliance manufacturers have traditionally performed physical testing using prototypes to assess reliability and service integrity of new product designs. However, for white goods where service lives are measured in years or decades, the use of endurance testing to analyze long time reliability is uneconomical. As accelerated life testing (ALT) is more efficient and less costly than traditional reliability testing, the methodology is finding increased usage by appliance manufacturers. In the present study, a simulation-based ALT approach was used to predict the service life of a polyacetal hinge cam from a consumer refrigerator. A predictive life stress model based on cumulative surface wear under accelerated stress conditions was developed and used to predict time to failure under consumer use. Results show that the life stress model demonstrated good agreement with performance testing data and reasonably predicts hinge life

Electron Parallel Closures for the 3 + 1 Fluid Model

Linear closures are obtained for arbitrary collisionality for the 3 þ 1 fluid model which includes the evolution of density, flow velocity, and pressure both parallel and perpendicular to a preferred direction, usually a magnetic field. A large set of 6400 moment equations is solved to provide closures that are accurate in the collisional regime and well into the collisionless regime. The closures in the collisionless limit are determined by solving the kinetic equation with a model collision operator. Simple fits for the kernel functions that define the closures are obtained for arbitrary collisionality in wave number space. The results are linearly accurate to within 3% across the entire range of collisionality

Fracture of a viscous liquid

When a viscous liquid hits a pool of liquid of same nature, the impact region is hollowed by the shock. Its bottom becomes extremely sharp if increasing the impact velocity, and we report that the curvature at that place increases exponentially with the flow velocity, in agreement with a theory by Jeong and Moffatt. Such a law defines a characteristic velocity for the collapse of the tip, which explains both the cusp-like shape of this region, and the instability of the cusp if increasing (slightly) the impact velocity. Then, a film of the upper phase is entrained inside the pool. We characterize the critical velocity of entrainment of this phase and compare our results with recent predictions by Eggers

Genomic Analysis of Immune Response against Vibrio Cholerae Hemolysin in Caenorhabditis elegans

Vibrio cholerae cytolysin (VCC) is among the accessory V. cholerae virulence factors that may contribute to disease pathogenesis in humans. VCC, encoded by hlyA gene, belongs to the most common class of bacterial toxins, known as poreforming toxins (PFTs). V. cholerae infects and kills Caenorhabditis elegans via cholerae toxin independent manner. VCC is required for the lethality, growth retardation and intestinal cell vacuolation during the infection. However, little is known about the host gene expression responses against VCC. To address this question we performed a microarray study in C. elegans exposed to V. cholerae strains with intact and deleted hlyA genes. Many of the VCC regulated genes identified, including C-type lectins, Prion-like (glutamine [Q]/asparagine [N]-rich)-domain containing genes, genes regulated by insulin/ IGF-1-mediated signaling (IIS) pathway, were previously reported as mediators of innate immune response against other bacteria in C. elegans. Protective function of the subset of the genes up-regulated by VCC was confirmed using RNAi. By means of a machine learning algorithm called FastMEDUSA, we identified several putative VCC induced immune regulatory transcriptional factors and transcription factor binding motifs. Our results suggest that VCC is a major virulence factor, which induces a wide variety of immune response- related genes during V. cholerae infection in C. elegans

Spatiotemporal regulation of a Legionella pneumophila T4SS substrate by the metaeffector SidJ

Modulation of host cell function is vital for intracellular pathogens to survive and replicate within host cells. Most commonly, these pathogens utilize specialized secretion systems to inject substrates (also called effector proteins) that function as toxins within host cells. Since it would be detrimental for an intracellular pathogen to immediately kill its host cell, it is essential that secreted toxins be inactivated or degraded after they have served their purpose. The pathogen Legionella pneumophila represents an ideal system to study interactions between toxins as it survives within host cells for approximately a day and its Dot/Icm type IVB secretion system (T4SS) injects a vast number of toxins. Previously we reported that the Dot/Icm substrates SidE, SdeA, SdeB, and SdeC (known as the SidE family of effectors) are secreted into host cells, where they localize to the cytoplasmic face of the Legionella containing vacuole (LCV) in the early stages of infection. SidJ, another effector that is unrelated to the SidE family, is also encoded in the sdeC-sdeA locus. Interestingly, while over-expression of SidE family proteins in a wild type Legionella strain has no effect, we found that their over-expression in a ∆sidJ mutant completely inhibits intracellular growth of the strain. In addition, we found expression of SidE proteins is toxic in both yeast and mammalian HEK293 cells, but this toxicity can be suppressed by co-expression of SidJ, suggesting that SidJ may modulate the function of SidE family proteins. Finally, we were able to demonstrate both in vivo and in vitro that SidJ acts on SidE proteins to mediate their disappearance from the LCV, thereby preventing lethal intoxication of host cells. Based on these findings, we propose that SidJ acts as a metaeffector to control the activity of other Legionella effectors