Studies on the Effect of Dust–Ion Collision on Dust–Ion Acoustic Solitary Waves in a Magnetized Dusty Plasma in the Framework of Damped KP Equation and Modified Damped KP Equation

Plasma Physics Reports - The influence of the dust–ion collision effect on the propagation of ion–acoustic waves (IAWs) in a collisional magnetized dusty plasma containing positive...     

Kadomtsev−Petviashvili equation for a flow of highly nonisothermal collisionless plasma

It is shown that the equations of two-fluid electrodynamics for a cold ions flow and Boltzmann electrons in the vicinity of the ion-sound point can be reduced to the Kadomtsev?Petviashvili equation. Examples of two-dimensional equilibria with pole singularities obtained by exactly solving the equations are presented. An exact self-similar solution describing a two-dimensional transonic flow and having no pole singularities is found.     

Cylindrical Magnetosonic Solitary Waves by Modified Korteweg–de Vries–Burgers Equation in Electron–Positron–Ion Plasma

Plasma Physics Reports - Theoretical investigations are carried out for the cylindrical magnetosonic solitary waves in dissipative, hot electron–positron–ion plasma. By the reductive...     

Formation of Microspherules of Lunar Regolith in Plasma–Dust Processes Initiated by Meteoroid Impacts

Plasma Physics Reports - The possibility of the formation of microspherules in plasma-dust processes initiated by meteoroids impacting the lunar surface is discussed. It is demonstrated that...     

Nonlinear equation for Farley–Buneman waves in multispecies plasma

The nonlinear equation describing the Farley–Buneman (FB) waves in multispecies collisional plasmas is derived by employing the multiple-scale reduction analysis. It is shown that the presence of several ion species with different collisionalities and different ion masses removes the degeneracy of the nonlinear equation and generates the nonlinear terms resulting in wave steepening and wave breaking. This effect may be responsible for formation of one-dimensional coherent FB waves of a finite amplitude.     

Nonlinear Propagation of Electrostatic Waves in Alkali–Fullerene Plasmas

Plasma Physics Reports - Linear and nonlinear propagation of electrostatic waves is studied in electron-depleted bi-ion plasmas where positive and negative ions have different masses and charge...     

Existence of Traveling Waves for the Generalized F–KPP Equation

Variation in genotypes may be responsible for differences in dispersal rates, directional biases, and growth rates of individuals. These traits may favor certain genotypes and enhance their spatiotemporal spreading into areas occupied by the less advantageous genotypes. We study how these factors influence the speed of spreading in the case of two competing genotypes under the assumption that spatial variation of the total population is small compared to the spatial variation of the frequencies of the genotypes in the population. In that case, the dynamics of the frequency of one of the genotypes is approximately described by a generalized Fisher–Kolmogorov–Petrovskii–Piskunov (F–KPP) equation. This generalized F–KPP equation with (nonlinear) frequency-dependent diffusion and advection terms admits traveling wave solutions that characterize the invasion of the dominant genotype. Our existence results generalize the classical theory for traveling waves for the F–KPP with constant coefficients. Moreover, in the particular case of the quadratic (monostable) nonlinear growth–decay rate in the generalized F–KPP we study in detail the influence of the variance in diffusion and mean displacement rates of the two genotypes on the minimal wave propagation speed.     

Radiative Surface Waves in Layered Plasma–Dielectric Structures and Prospects of Their Application in Plasma Microwave Electronics

Plasma Physics Reports - Surface waves in layered systems consisting of material media with different frequency dispersions are considered: dielectric–plasma–vacuum,...     

Common Physical Errors in the Description of Water Fluxes in the Soil–Plant–Atmosphere System

Widely accepted concepts and definitions concerning the driving forces of upward water fluxes, such as osmotic pressure (OP) and water potential (WP), were analyzed in the soil–plant–atmosphere system. It is emphasized that, at present, there are no physically correct definitions of the mentioned parameters, because such a concept as the heat pressure of molecules in a liquid has not been introduced. Physical definitions of OP and WP are presented. It is demonstrated that WP is not a driving force for water fluxes at the water–vapor interface. The fundamental difference in mechanisms of diffusion fluxes and active transport across the biological membranes is analyzed. The biological specificity of driving forces at the soil–root and leaf–air interfaces is described.     

Three-Dimensional Structures of the Spatiotemporal Nonlinear Schr?dinger Equation with Power-Law Nonlinearity in PT-Symmetric Potentials

The spatiotemporal nonlinear Schrödinger equation with power-law nonlinearity in -symmetric potentials is investigated, and two families of analytical three-dimensional spatiotemporal structure solutions are obtained. The stability of these solutions is tested by the linear stability analysis and the direct numerical simulation. Results indicate that solutions are stable below some thresholds for the imaginary part of -symmetric potentials in the self-focusing medium, while they are always unstable for all parameters in the self-defocusing medium. Moreover, some dynamical properties of these solutions are discussed, such as the phase switch, power and transverse power-flow density. The span of phase switch gradually enlarges with the decrease of the competing parameter k in -symmetric potentials. The power and power-flow density are all positive, which implies that the power flow and exchange from the gain toward the loss domains in the cell.     

Nonlinear dynamics of beam–plasma instability in a finite magnetic field

The nonlinear dynamics of beam–plasma instability in a finite magnetic field is investigated numerically. In particular, it is shown that decay instability can develop. Special attention is paid to the influence of the beam?plasma coupling factor on the spectral characteristics of a plasma relativistic microwave accelerator (PRMA) at different values of the magnetic field. It is shown that two qualitatively different physical regimes take place at two values of the external magnetic field: B ₀ = 4.5 kG (Ω ~ ωB _p ) and 20 kG (Ω _B ? ω_p). For B ₀ = 4.5 kG, close to the actual experimental value, there exists an optimal value of the gap length between the relativistic electron beam and the plasma (and, accordingly, an optimal value of the coupling factor) at which the PRMA output power increases appreciably, while the noise level decreases.     

On the Buildup of Ion–Acoustic Instability in Plasma with Two Types of Ions

Plasma Physics Reports - The issues of the onset of ion–acoustic instability of the reverse current in a hot plasma with parameters corresponding to the laser thermonuclear fusion plasma are...     

Nonlinear Wave Structures of Electron Acoustic Waves in Nonextensive Magnetized Electron–Positron–Ion Plasmas

Plasma Physics Reports - A multicomponent collisionless magnetized plasma system consisting of cold mobile electron fluid, hot electrons and positrons following the q-nonextensive distribution, and...     

Linear and Weakly Nonlinear Stability Analyses of Turing Patterns for Diffusive Predator–Prey Systems in Freshwater Marsh Landscapes

We study a diffusive predator–prey model describing the interactions of small fishes and their resource base (small invertebrates) in the fluctuating freshwater marsh landscapes of the Florida Everglades. The spatial model is described by a reaction–diffusion system with Beddington–DeAngelis functional response. Uniform bound, local and global asymptotic stability of the steady state of the PDE model under the no-flux boundary conditions are discussed in details. Sufficient conditions on the Turing (diffusion-driven) instability which induces spatial patterns in the model are derived via linear analysis. Existence of one-dimensional and two-dimensional spatial Turing patterns, including rhombic and hexagonal patterns, are established by weakly nonlinear analyses. These results provide theoretical explanations and numerical simulations of spatial dynamical behaviors of the wetland ecosystems of the Florida Everglades.     

Higher Dimensional Gaussian-Type Solitons of Nonlinear Schr?dinger Equation with Cubic and Power-Law Nonlinearities in PT-Symmetric Potentials

Two families of Gaussian-type soliton solutions of the (n+1)-dimensional Schrödinger equation with cubic and power-law nonlinearities in -symmetric potentials are analytically derived. As an example, we discuss some dynamical behaviors of two dimensional soliton solutions. Their phase switches, powers and transverse power-flow densities are discussed. Results imply that the powers flow and exchange from the gain toward the loss regions in the cell. Moreover, the linear stability analysis and the direct numerical simulation are carried out, which indicates that spatial Gaussian-type soliton solutions are stable below some thresholds for the imaginary part of -symmetric potentials in the defocusing cubic and focusing power-law nonlinear medium, while they are always unstable for all parameters in other media.     

Profile of an Ion–Acoustic Solitary Wave in Plasma with Negative Ions

Plasma Physics Reports - A method for numerical calculation of the profile of an ion–acoustic solitary wave in plasma with negative ions and, as a particular case, in electron–ion...     

Modified method for determination of sulfur metabolites in plant tissues by stable isotope dilution-based liquid chromatography–electrospray ionization–tandem mass spectrometry

A wide variety of sulfur metabolites play important roles in plant functions. We have developed a precise and sensitive method for the simultaneous measurement of several sulfur metabolites based on liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) and ³⁴S metabolic labeling of sulfur-containing metabolites in Arabidopsis thaliana seedlings. However, some sulfur metabolites were unstable during the extraction procedure. Our proposed method does not allow for the detection of the important sulfur metabolite homocysteine because of its instability during sample extraction. Stable isotope-labeled sulfur metabolites of A. thaliana shoot were extracted and utilized as internal standards for quantification of sulfur metabolites with LC–MS/MS using S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), methionine (Met), glutathione (GSH), and glutathione disulfide (GSSG) as example metabolites. These metabolites were detected using electrospray ionization in positive mode. Standard curves were linear (r² > 0.99) over a range of concentrations (SAM 0.01–2.0 μM, SAH 0.002–0.10 μM, Met 0.05–4.0 μM, GSH 0.17–20.0 μM, GSSG 0.07–20.0 μM), with limits of detection for SAM, SAH, Met, GSH, and GSSG of 0.83, 0.67, 10, 0.56, and 1.1 nM, respectively; and the within-run and between-run coefficients of variation based on quality control samples were less than 8%.     

Spatial–Temporal Properties of Current-Convective Turbulence in Divertor Plasma under DIII-D-Like Detached Conditions

Plasma Physics Reports - Recent experimental observations of divertor plasma turbulence at the ASDEX Upgrade tokamak have demonstrated the onset of strong fluctuations of plasma radiation intensity...     

Use of a Modified α-N-Acetylgalactosaminidase in the Development of Enzyme Replacement Therapy for Fabry Disease

A modified α-N-acetylgalactosaminidase (NAGA) with α-galactosidase A (GLA)-like substrate specificity was designed on the basis of structural studies and was produced in Chinese hamster ovary cells. The enzyme acquired the ability to catalyze the degradation of 4-methylumbelliferyl-α-D-galactopyranoside. It retained the original NAGA''s stability in plasma and N-glycans containing many mannose 6-phosphate (M6P) residues, which are advantageous for uptake by cells via M6P receptors. There was no immunological cross-reactivity between the modified NAGA and GLA, and the modified NAGA did not react to serum from a patient with Fabry disease recurrently treated with a recombinant GLA. The enzyme cleaved globotriaosylceramide (Gb3) accumulated in cultured fibroblasts from a patient with Fabry disease. Furthermore, like recombinant GLA proteins presently used for enzyme replacement therapy (ERT) for Fabry disease, the enzyme intravenously injected into Fabry model mice prevented Gb3 storage in the liver, kidneys, and heart and improved the pathological changes in these organs. Because this modified NAGA is hardly expected to cause an allergic reaction in Fabry disease patients, it is highly promising as a new and safe enzyme for ERT for Fabry disease.