Standard and Embedded Solitons in Nematic Optical Fibers

A model for a non-Kerr cylindrical nematic fiber is presented. We use the multiple scales method to show the possibility of constructing different kinds of wavepackets of transverse magnetic (TM) modes propagating through the fiber. This procedure allows us to generate different hierarchies of nonlinear partial differential equations (PDEs) which describe the propagation of optical pulses along the fiber. We go beyond the usual weakly nonlinear limit of a Kerr medium and derive an extended Nonlinear Schrodinger equation (eNLS) with a third order derivative nonlinearity, governing the dynamics for the amplitude of the wavepacket. In this derivation the dispersion, self-focussing and diffraction in the nematic are taken into account. Although the resulting nonlinear $PDE$ may be reduced to the modified Korteweg de Vries equation (mKdV), it also has additional complex solutions which include two-parameter families of bright and dark complex solitons. We show analytically that under certain conditions, the bright solitons are actually double embedded solitons. We explain why these solitons do not radiate at all, even though their wavenumbers are contained in the linear spectrum of the system. Finally, we close the paper by making comments on the advantages as well as the limitations of our approach, and on further generalizations of the model and method presented.Comment: "Physical Review E, in press

TOI-222: A single-transit TESS candidate revealed to be a 34-d eclipsing binary with CORALIE, EulerCam, and NGTS

We report the period, eccentricity, and mass determination for the Transiting Exoplanet Survey Satellite (TESS) single-transit event candidate TOI-222, which displayed a single 3000 ppm transit in the TESS 2-min cadence data from Sector 2. We determine the orbital period via radial velocity measurements (P = 33.9 d), which allowed for ground-based photometric detection of two subsequent transits. Our data show that the companion to TOI-222 is a low-mass star, with a radius of 0.18+−003910 R☉ and a mass of 0.23 ± 0.01 M☉. This discovery showcases the ability to efficiently discover long-period systems from TESS single-transit events using a combination of radial velocity monitoring coupled with high-precision ground-based photometry

Enhanced Degradation of TCE on a Superfund Site Using Endophyte-Assisted Poplar Tree Phytoremediation

Trichloroethylene (TCE) is a widespread environmental pollutant common in groundwater plumes associated with industrial manufacturing areas. We had previously isolated and characterized a natural bacterial endophyte, Enterobacter sp. strain PDN3, of poplar trees, that rapidly metabolizes TCE, releasing chloride ion. We now report findings from a successful three-year field trial of endophyte-assisted phytoremediation on the Middlefield-Ellis-Whisman Superfund Study Area TCE plume in the Silicon Valley of California. The inoculated poplar trees exhibited increased growth and reduced TCE phytotoxic effects with a 32% increase in trunk diameter compared to mock-inoculated control poplar trees. The inoculated trees excreted 50% more chloride ion into the rhizosphere, indicative of increased TCE metabolism in planta. Data from tree core analysis of the tree tissues provided further supporting evidence of the enhanced rate of degradation of the chlorinated solvents in the inoculated trees. Test well groundwater analyses demonstrated a marked decrease in concentration of TCE and its derivatives from the tree-associated groundwater plume. The concentration of TCE decreased from 300 \u3bcg/L upstream of the planted area to less than 5 \u3bcg/L downstream of the planted area. TCE derivatives were similarly removed with cis-1,2-dichloroethene decreasing from 160 \u3bcg/L to less than 5 \u3bcg/L and trans-1,2-dichloroethene decreasing from 3.1 \u3bcg/L to less than 0.5 \u3bcg/L downstream of the planted trees. 1,1-dichloroethene and vinyl chloride both decreased from 6.8 and 0.77 \u3bcg/L, respectively, to below the reporting limit of 0.5 \u3bcg/L providing strong evidence of the ability of the endophytic inoculated trees to effectively remove TCE from affected groundwater. The combination of native pollutant-degrading endophytic bacteria and fast-growing poplar tree systems offers a readily deployable, cost-effective approach for the degradation of TCE, and may help mitigate potential transfer up the food chain, volatilization to the atmosphere, as well as direct phytotoxic impacts to plants used in this type of phytoremediation

Genome sequence of the plant growth promoting endophytic yeast Rhodotorula graminis WP1

Here we present the genome sequence of Rhodotorula graminis WP1, a pink-pigmented, encapsulated yeast strain belonging to the Basidiomycota phylum that was isolated from within stems of Populus trichocarpa growing in its native riparian environment alongside the Snoqualmie River in Western Washington state(Xin et al., 2009). Although numerous bacterial endophytes, the microorganisms living fully within plants, have been characterized, relatively few endophytic yeast strains have been studied (Doty, 2011). The genome of strain WP1 was the first endophytic yeast to be sequenced, and has been included in several genomic analyses (Spatafora et al., 2013; Nagy et al., 2014; Pendleton et al., 2014). Although originally isolated from poplar, WP1 has a broad host range, providing growth benefits not only to poplar (Knoth et al., 2014; Khan et al. in review) but also to grasses and agricultural crop species (Khan et al., 2012; Knoth et al., 2013). Strain WP1 improves plant vigor and has useful biochemical properties (Doty, 2014) including the ability to ferment both pentoses and hexoses and to degrade fermentation inhibitors (Xu et al., 2011). Genomic analysis of bacterial endophytes has revealed certain features in common including genes for phytohormone synthesis, adhesion, colonization, stress reduction, and iron and phosphate acquisition (Fouts et al., 2008; Taghavi et al., 2010; Sessitsch et al., 2012; Witzel et al., 2012). We analyzed the genome of WP1 with a focus on genes potentially involved in plant-microbe interactions

Solution operator method of radiation transport equation with non-coherent and anisotropic scattering

The equation of the optical radiation transfer in a spectral line is considered in the paper aiming at the solution explicit form obtaining by operator methods. As a result new explicit formulae for the radiation transfer in a line have been obtained. New formulae may be used for the testing and construction of special calculation methods of transfer theoryAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio