Operational parameters for the superconducting cavity maser

Tests of the superconducting cavity maser (SCM) ultra-stable frequency source have been made for the first time using a hydrogen maser for a frequency reference. In addition to characterizing the frequency stability, the sensitivity of the output frequency to several crucial parameters was determined for various operating conditions. Based on this determination, the refrigeration and thermal control systems of the SCM were modified. Subsequent tests showed substantially improved performance, especially at the longest averaging times

Application of quasi-Monte Carlo methods to PDEs with random coefficients -- an overview and tutorial

This article provides a high-level overview of some recent works on the application of quasi-Monte Carlo (QMC) methods to PDEs with random coefficients. It is based on an in-depth survey of a similar title by the same authors, with an accompanying software package which is also briefly discussed here. Embedded in this article is a step-by-step tutorial of the required analysis for the setting known as the uniform case with first order QMC rules. The aim of this article is to provide an easy entry point for QMC experts wanting to start research in this direction and for PDE analysts and practitioners wanting to tap into contemporary QMC theory and methods.Comment: arXiv admin note: text overlap with arXiv:1606.0661

Semiparametric analysis to estimate the deal effect curve

The marketing literature suggests several phenomena that may contribute to the shape of the relationship between sales and price discounts. These phenomena can produce severe nonlinearities and interactions in the curves, and we argue that those are best captured with a flexible approach. Since a fully nonparametric regression model suffers from the curse of dimensionality, we propose a semiparametric regression model. Store-level sales over time is modeled as a nonparametric function of own-and cross-item price discounts, and a parametric function of other predictors (all indicator variables). We compare the predictive validity of the semiparametric model with that of two parametric benchmark models and obtain better performance on average. The results for three product categories indicate a.o. threshold- and saturation effects for both own- and cross-item temporary price cuts. We also show how the own-item curve depends on other items’ price discounts (flexible interaction effects). In a separate analysis, we show how the shape of the deal effect curve depends on own-item promotion signals. Our results indicate that prevailing methods for the estimation of deal effects on sales are inadequate.

Hot new directions for quasi-Monte Carlo research in step with applications

This article provides an overview of some interfaces between the theory of quasi-Monte Carlo (QMC) methods and applications. We summarize three QMC theoretical settings: first order QMC methods in the unit cube $[0,1]^s$ and in $\mathbb{R}^s$, and higher order QMC methods in the unit cube. One important feature is that their error bounds can be independent of the dimension $s$ under appropriate conditions on the function spaces. Another important feature is that good parameters for these QMC methods can be obtained by fast efficient algorithms even when $s$ is large. We outline three different applications and explain how they can tap into the different QMC theory. We also discuss three cost saving strategies that can be combined with QMC in these applications. Many of these recent QMC theory and methods are developed not in isolation, but in close connection with applications

Correspondence Between DGP Brane Cosmology and 5D Ricci-flat Cosmology

We discuss the correspondence between the DGP brane cosmology and 5D Ricci-flat cosmology by letting their metrics equal each other. By this correspondence, a specific geometrical property of the arbitrary integral constant I in DGP metric is given and it is related to the curvature of 5D bulk. At the same time, the relation of arbitrary functions $\mu$ and $\nu$ in a class of Ricci-flat solutions is obtained from DGP brane metric.Comment: 8 pages, 1 figure, accepted by MPLA, added referenc

Determinación de parámetros aerodinámicos del cohete SLAM PAMPERO

En este trabajo se ofrecerá una revisión de la memoria de cálculo aerodinámico del cohete de artillería SLAM PAMPERO calibre 105 mm., de características balísticas conocidas, y provisto y en servicio activo en el Ejército Argentino desde hace más de 30 años. Habida cuenta que en décadas pasadas, para poder aproximar los resultados se contaban con herramientas muy limitadas, hoy es factible disponer de un herramental más moderno. Para poder precisar la trayectoria, es necesario conocer la balística interior del motor y resolver la balística exterior y la aerodinámica del cohete completo. La primera se caracteriza a partir de cálculos analíticos, empíricos y de ensayos en banco estático, mientras que para la balística exterior y la aerodinámica son imprescindibles los procesamientos analíticos y numéricos, más los ensayos en túnel de viento y las trayectografías, lo que desemboca en la tabla de tiro. En este estudio, para determinar los coeficientes aerodinámicos empleamos distintas metodologías de cálculo, a fin de poder apreciar su nivel de aproximación y su utilidad en las diferentes fases de un proyecto. En primer lugar se utilizó el programa semiempirico MISSILE DATCOM, para continuar los mismo cálculos con el método de paneles PAN AIR. Finalmente se estudió el cohete a través de metodologías de CFD por volúmenes finitos. A partir de estas herramientas, se pudo delimitar la variación del coeficiente de resistencia (CD) en función del número de Mach. De esa manera, se comprobó la trayectoria con diversas técnicas, validándose los resultados al compararlos con los definidos en la tabla de tiro de cohete, ya existente. Este procedimiento dio lugar a trazar la curva de resistencia que se corresponde con la trayectoria real, y se validó el nivel de aproximación/complejidad de cada método de cálculo

The isolation from Saccharomyces cerevisiae of two antibacterial cationic proteins that inhibit malolactic bacteria

Substances with antibacterial activity were recovered from the extracellular medium and from the acidified cell extract of Saccharomyces cerevisiae R107 by binding onto a cation exchanger. The fraction eluted with NaOH contained two different antibacterial factors, one with the characteristics of lysozyme, the other apparently a small protein with a similar high pI.Die Isolierung von zwei bakteriziden, kationischen Proteinen aus Saccharomyces cerevisiae, die Bakterien des Säureabbaus hemmenSubstanzen mit bakterizider Wirkung wurden sowohl aus dem Kultursubstrat als auch aus angesäuertem Zellextrakt von Saccharomyces cerevisiae Rl07 mit Hilfe von Kationenaustauscher isoliert. Die mit NaOH eluierte Fraktion enthielt zwei unterschiedliche bakterizide Substanzen, eine mit Lysozymeigenschaften, die andere, ein kleines Protein, mit ähnlich hohem isoelektrischen Punkt

Adalimumab in the treatment of pediatric patients with chronic noninfectious anterior uveitis

Introduction: Adalimumab is established as an effective treatment for pediatric noninfectious uveitis refractory to methotrexate. However current use of the medication is empiric, according to fixed-dosing regimens and a significant proportion of patients will be nonresponsive or suboptimally responsive to adalimumab. Areas covered: There remains considerable scope to improve outcomes through tailoring treatment according to individual patient responsiveness. Monitoring of anti-drug antibodies and serum drug trough levels may assist in predicting which patients are likely to have a poor response to adalimumab and enable tailoring of regimens to individual patients. Expert opinion: We propose use of these biomarkers to individualize therapy in suboptimally responding patients, and present an algorithm of treatment escalation for pediatric noninfectious uveitis

Understanding mechanisms of genetic risk for adolescent internalizing and externalizing problems: The mediating role of parenting and personality

Genetic predispositions play an important role in the development of internalizing and externalizing behaviors. Understanding the mechanisms through which genetic risk unfolds to influence these developmental outcomes is critical for developing prevention and intervention efforts, capturing key elements of Irv's research agenda and scientific legacy. In this study, we examined the role of parenting and personality in mediating the effect of genetic risk on adolescents' major depressive disorder and conduct disorder symptoms. Longitudinal data were drawn from a sample of 709 European American adolescents and their mothers from the Collaborative Studies on Genetics of Alcoholism. Results from multivariate path analysis indicated that adolescents' depressive symptoms genome-wide polygenic scores (DS_GPS) predicted lower parental knowledge, which in turn was associated with more subsequent major depressive disorder and conduct disorder symptoms. Adolescents' DS_GPS also had indirect effects on these outcomes via personality, with a mediating effect via agreeableness but not via other dimensions of personality. Findings revealed that the pattern of associations was similar across adolescent gender. Our findings emphasize the important role of evocative gene-environment correlation processes and intermediate phenotypes in the pathways of risk from genetic predispositions to complex adolescent outcomes