Mode-coupling and nonlinear Landau damping effects in auroral Farley-Buneman turbulence

The fundamental problem of Farley-Buneman turbulence in the auroral $E$-region has been discussed and debated extensively in the past two decades. In the present paper we intend to clarify the different steps that the auroral $E$-region plasma has to undergo before reaching a steady state. The mode-coupling calculation, for Farley-Buneman turbulence, is developed in order to place it in perspective and to estimate its magnitude relative to the anomalous effects which arise through the nonlinear wave-particle interaction. This nonlinear effect, known as nonlinear ``Landau damping'' is due to the coupling of waves which produces other waves which in turn lose energy to the bulk of the particles by Landau damping. This leads to a decay of the wave energy and consequently a heating of the plasma. An equation governing the evolution of the field spectrum is derived and a physical interpration for each of its terms is provided

A study investigating the comparative effects of an audiation pause in tonal pattern training on fourth and fifth grade children

The purpose of this study is to examine variations of response time in tonal pattern training. The problem of the study is twofold. 1) To determine the comparative effect of fourth and fifth grade students who echoed tonal patterns immediately and students who echoed after a pause, and 2) to examine how the variations in response time in tonal pattern training effects the performance of high and low aptitude students. The sample for this study consisted of approximately 140 fourth and fifth grade students who attended an elementary school located in a Southern New Jersey suburban community. The sample included six intact classes, each class randomly assigned to the treatment group and the control group. All six classes received music instruction once a week for 40 minutes from the investigator. The Intermediate Measures of Music Audiation (IMMA) was administered to all students during regularly scheduled music classes prior to the beginning of the tonal pattern instruction to determine each student\u27s level of musical aptitude. During the ten weeks of instruction, the subjects participated in tonal pattern training during their regularly scheduled music class singing tonic and dominant tonal patterns in major and minor, first at the aural/oral level and then at the verbal association level. At the end of the period, students were tested individually on their singing achievement of tonal patterns. Within two weeks of the completion of the tonal training, students were tape-recorded singing familiar and unfamiliar tonal patterns on the neutral syllable bum in major and minor. Two judges were trained to evaluate the student performances using a criterion-referenced tonal rating scale. The interjudge reliability between judges was calculated at .915. No statistically significant differences were found for either the interaction or main effect for the treatment. As expected, however, a main effect for aptitude was confirmed through statistical analysis. Based on the evidence acquired from this study, it cannot be concluded that variations of response time in tonal pattern training is a necessary component for learning theory pedagogy

Characterization of the HIV-1 RNA associated proteome identifies Matrin 3 as a nuclear cofactor of Rev function

<p>Abstract</p> <p>Background</p> <p>Central to the fully competent replication cycle of the human immunodeficiency virus type 1 (HIV-1) is the nuclear export of unspliced and partially spliced RNAs mediated by the Rev posttranscriptional activator and the Rev response element (RRE).</p> <p>Results</p> <p>Here, we introduce a novel method to explore the proteome associated with the nuclear HIV-1 RNAs. At the core of the method is the generation of cell lines harboring an integrated provirus carrying RNA binding sites for the MS2 bacteriophage protein. Flag-tagged MS2 is then used for affinity purification of the viral RNA. By this approach we found that the viral RNA is associated with the host nuclear matrix component MATR3 (Matrin 3) and that its modulation affected Rev activity. Knockdown of MATR3 suppressed Rev/RRE function in the export of unspliced HIV-1 RNAs. However, MATR3 was able to associate with Rev only through the presence of RRE-containing viral RNA.</p> <p>Conclusions</p> <p>In this work, we exploited a novel proteomic method to identify MATR3 as a cellular cofactor of Rev activity. MATR3 binds viral RNA and is required for the Rev/RRE mediated nuclear export of unspliced HIV-1 RNAs.</p

Zonal flow and zonal magnetic field generation by finite β drift waves: a theory for low to high transitions in tokamaks

The understanding of low to high (L-H) transition in tokamaks has been an important area of investigation for more than a decade. Recent 3D finite β simulations of drift-resistive ballooning modes in a flux tube geometry by Rogers et al. [Phys. Rev. Lett. 81, 4396 (1998)] have provided a unique parametrization of the transition in a two-dimensional phase space. Comparison of the threshold curve in this phase space with data from ASDEX and C-MOD has shown very good agreement. In this Letter we provide a simple theory, based on the generation of zonal flow and zonal magnetic field in a finite-beta plasma, which explains this threshold curve for L-H transition in tokamaks

Особенности расчета экономических показателей высокоскоростных лоцманских катеров на этапе концептуального проектирования

Клева, Я. А. Особенности расчета экономических показателей высокоскоростных лоцманских катеров на этапе концептуального проектирования = Features of economic indicators calculation for high speed pilot boat on stage of conceptual design / Я. А. Клева // Зб. наук. пр. НУК. – Миколаїв : НУК, 2016. – № 4 (466). – С. 22–27.Залежності для розрахунку основних економічних показників розглянуті з врахуванням специфіки експлуатації швидкісних лоцманських катерів. Формули, що пропонуються, можуть використовуватися для вирішення задач вибору оптимальних характеристик лоцманського катера.During the last decades a vast amount of research has been focused on the issues of design, operations, and development of more optimized structures of high-speed craft. The right choice of the criterion function is crucial. Fundamentally, efficiency can be increased with the reduction of production costs, operational costs, and environmental impact, while maintaining or improving craft performance, reliability, and safety. The estimation of economic performances of pilot boats in conceptual design phase should account for many features, such as, different building materials, development of the hull design, choice of the propeller, conditions of operations, and others. The majority of estimation techniques are developed specifically for large ships and, therefore, do not take into account the essential features of design and function of small high-speed craft, namely, pilot boats. Іn this paper we present formulas for estimation of building cost of the conventional pilot boat (a monohull). The author recommends the set of formulas for estimation, which form the mathematical model. These equations can be used in the optimization task.Представлены зависимости для расчета основных экономических показателей с учетом специфики проектирования и эксплуатации высокоскоростных лоцманских катеров. Полученные формулы могут быть использованы при решении задачи выбора оптимальных характеристик лоцманского катера

Diamagnetic Suppression of Component Magnetic Reconnection at the Magnetopause

We present particle-in-cell simulations of collisionless magnetic reconnection in a system (like the magnetopause) with a large density asymmetry across the current layer. In the presence of an ambient component of the magnetic field perpendicular to the reconnection plane the gradient creates a diamagnetic drift that advects the X-line with the electron diamagnetic velocity. When the relative drift between the ions and electrons is of the order the Alfven speed the large scale outflows from the X-line necessary for fast reconnection cannot develop and the reconnection is suppressed. We discuss how these effects vary with both the plasma beta and the shear angle of the reconnecting field and discuss observational evidence for diamagnetic stabilization at the magnetopause.Comment: 10 pages, 10 figures; accepted by JGR; agu2001.cls and agu.bst include