A Polarization Filter Based on a Novel Photonic Crystal Fiber with a Gold-Coated Air Hole by Using Surface Plasmon Resonance

A novel design of a polarization filter based on photonic crystal fiber (PCF) is proposed in this paper. With the introduction of a gold-coated air hole, the resonance strength is much stronger in y-polarized direction than in x-polarized direction at some particular wavelengths, which is due to the metal surface plasmon effects. At the wavelength of 1.31 μm, the loss of y-polarized mode is 2138.34 dB/cm while the loss is very low in x polarization. Furthermore, the loss peak can be flexibly adjusted from the wavelength of 1.26 to 1.56 μm by changing the thickness of a gold layer, and the loss in y polarization can be kept above 1200 dB/cm. The significant loss in y polarization makes this PCF a good candidate for developing a polarization filter with high performance.     

Better tolerance to water deficit in doubled diploid ‘Carrizo citrange’ compared to diploid seedlings is associated with more limited water consumption

Tolerance to water deficit in diploid (2x) and doubled diploid (4x) ‘Carrizo citrange’ (Citrus sinensis [L.] Osbeck × Poncirus trifoliata [L.] Raf) was investigated. Water deficit was applied for 4 weeks. Physiological parameters, including stomatal conductance (g _s), photosynthesis (A), transpiration (E), leaf and soil water potentials (Ψ _leaf; Ψ _soil), and pot water loss, were monitored throughout the stress. Moreover, ABA, H₂O₂ contents, and the expression of genes involved in ABA biosynthesis (NCED3), regulation of abscisic acid signaling (ABI1), and coding for a catalase enzyme (CAT2) known to favor H₂O₂ scavenging were monitored. During the experiment g _s, A, and E values were most of the time higher in 2x compared to 4x. During the water deficit period, pot water loss decreased faster in 2x compared to 4x, leading to a faster decrease in all physiological parameters in 2x. The higher sensitivity of 2x compared to 4x was correlated with more numerous thinner roots, higher leaf ABA and H₂O₂ contents, and with the lower leaf water potential. ABI1 and NCED3 expression was not strictly correlated with the ABA content. However, the higher CAT2 expression in 4x was correlated with the lower leaf H₂O₂ contents. Therefore, the better tolerance observed in 4x ‘Carrizo citrange’ compared to 2x was associated with more limited water consumption and better and H₂O₂ scavenging.     

The effect of genetic environment on locus-specific instability of the <Emphasis Type="Italic">yellow</Emphasis> gene in the Uman’ population of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

The effects of genotype of the laboratory strains, C(1)DX, ywf/Y, 23.5 MRF/CyL ⁴, and C(1)DX,yf; π₂, on locus-specific instability in the yellow gene of the strains y ^2-217, y ^2-715, and y ^2-700 from Uman’ population of Drosophila melanogaster was studied. Crosses of the males from Uman’-derived lines with the C(1)DX,ywf/Y females yielded a cascade of derivatives, mostly consisting of y ⁺ and y ² alleles, while their crosses with the 23.5 MRF/CyL ⁴ and C(1)DX,yf; π₂ females mostly resulted in the appearance of y ⁺ and y ¹ derivatives. The genomes of laboratory strains used in the study contained the full-sized hobo elements, which could differ from one another relative to the structure of variable region and affinity to different DNA sequences.     

Chaotic Dynamics of Neuromuscular System Parameters and the Problems of the Evolution of Complexity

The evolution rate v(t) varies among diverse biosystems, but a general theory can be formulated when the dynamics of the biosystem stater x = x(t) = (x₁, x₂, x _m ) ^T is considered in the m-dimensional space of states. A mathematical approach is proposed for evaluating such processes and describes the processes in terms of particular chaos of the statistical distribution functions f(x). In the case of complex multicomponent systems with a high dimension number m (m ?1) of the phase space of states, we propose using pairwise comparison matrices of samples x(t) when homeostasis is constant and calculating the parameters of quasiattractors. The Glensdorff–Prigogine thermodynamic approach to estimating evolution is inefficient in assessing the third-type systems, while it is applicable and the Prigogine theorem works at the level of molecular systems. Alterations in the state of the human neuromuscular system were found to lead to chaotic changes in the statistical functions f(x) in tremor recording samples, while quasiattractor parameters demonstrate a certain regularity.     

Quantitative trait locus mapping of genes associated with vacuolation in the adrenal X-zone of the DDD/Sgn inbred mouse

Background

Adrenal gland of mice contains a transient zone between the adrenal cortex and the adrenal medulla: the X-zone. There are clear strain differences in terms of X-zone morphology. Nulliparous females of the inbred mouse DDD strain develop adrenal X-zones containing exclusively vacuolated cells, whereas females of the inbred mouse B6 strain develop X-zones containing only non-vacuolated cells. The X-zone vacuolation is a physiologic process associated with the X-zone degeneration and is tightly regulated by genetic factors. Identification of the genetic factors controlling such strain differences should help analyze the X-zone function. In this study, a quantitative trait locus (QTL) analysis for the extent of X-zone vacuolation was performed for two types of F₂ female mice: F₂A ^y mice (F₂ mice with the A ^y allele) and F₂ non-A ^y mice (F₂ mice without the A ^y allele). These were produced by crossing B6 females and DDD.Cg-A ^y males. DDD.Cg-A ^y is a congenic mouse strain for the A ^y allele at the agouti locus and is used for this study because a close association between the X-zone morphology and the agouti locus genotype has been suggested. The A ^y allele is dominant and homozygous lethal; therefore, living A ^y mice are invariably heterozygotes.

Results

Single QTL scans identified significant QTLs on chromosomes 1, 2, 6, and X for F₂ non-A ^y mice, and on chromosomes 2, 6, and 12 for F₂A ^y mice. The QTL on chromosome 2 was considered to be because of the agouti locus, which has been suggested to be associated with X-zone vacuolation. A significant QTL that interacted with the agouti locus was identified on chromosome 8.

Conclusions

The extent of X-zone vacuolation in DDD females was controlled by multiple genes with complex interactions. The murine X-zone is considered analogous structure to the human fetal zone. Therefore, the results of this study will aid in understanding function of not only of the X-zone but also of the human fetal zone. Identifying the genes responsible for the QTLs will be essential for understanding the molecular basis of X-zone function, which is currently unclear.

     

Adiabatic Heating of Electrons in the Magnetospheric Current Sheet

Electron dynamics and acceleration in an electromagnetic field configuration modeling the current sheet configuration of the Earth’s magnetotail region is investigated. A focus is made on the role of the dawn?dusk magnetic field component B_y in the convection electron heating by an electric field E_y. For numerical integration of a large number of test particle trajectories over long time intervals, the equations of motion written in the guiding center approximation are used. It is shown that the presence of a B_y ≠ 0 magnetic field significantly changes the electron heating and allows electrons with small pitch angles to gain energy much more efficiently than the equatorial electrons. As a result, the convection heating in the current sheet with B_y ≠ 0 leads to the formation of an accelerated anisotropic population of particles with energies higher than a few hundred electronvolts. The obtained results and spacecraft observations in the Earth’s magnetotail are compared, and possible limitations in the proposed model approaches are discussed.     

Microwave electrode discharge in nitrogen: Structure and characteristics of the electrode region

The parameters of the electrode region of an electrode microwave discharge in nitrogen are studied by emission spectroscopy. The radial and axial distributions of the intensities of the bands of the second (N₂(C ³Π _u → B ³Π _g )) and first (N₂(B ³Π _g → A ³Σ _u ⁺ )) positive systems of molecular nitrogen and the first negative system of nitrogen ions (N ₂ ⁺ (B ²Σ _u ⁺ → X ²Σ _g ⁺ )), the radial profiles of the electric field E and the electron density N _e , and the absolute populations of the vibrational levels v _C = 0–4 of the C ³Π _u excited state of N₂ and the vibrational level v _Bi = 0 of the B ²Σ _u ⁺ excited state of a molecular nitrogen ion are determined. The population temperature of the first vibrational level T _V of the ground electronic state X ¹Σ _g ⁺ of N₂ and the excitation temperature T _C of the C ³Π _u state in the electrode region of the discharge are measured. The radius of the spherical region and the spatially integrated plasma emission spectra are studied as functions of the incident microwave power and gas pressure. A method for determining the electron density and the microwave field strength from the plasma emission characteristics is described in detail.     

Mechanism for phenanthridines synthesis by nitrogenation of 2-acetylbiphenyls in acidic solution: a DFT study

The mechanism of phenanthridines synthesis from the nitrogenation of 2-acetylbiphenyls (1) by TMSN₃ in TFA has been studied by DFT calculations. Results at the B3LYP/6-311G(d) level showed that: 1) reaction of TMSN₃/HN₃ with the protonated form of 1 (1H⁺), which generates the key intermediate C ^x+ by removal of TMSOH/H₂O, is the rate determining step, and TMSN₃ as the nitrogen source is certainly preferred over HN₃. 2) from C ^x+, the two pathways leading to 2 ^x H⁺ and 3 ^x H⁺ are both thermodynamically and kinetically feasible and competitive to each other. 3) The high barriers of the reverse reactions suggest that the ratio of the final products 2 ^x :3 ^x is determined by the branching ratio of reaction rates of C ^x+ to intermediates D ^x+ in pass_I and E ^x+ in pass_II.

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Graphical Abstract DFT results indicate that the replacement of -OH by -N₃ which generates C ^x+ controls the consumption rate of 1 ^x H⁺, and the ratio of C ^x+ transforms to D ^x+ and C ^x+ transforms to E ^x+ (k:k') determines the final ratio of products 2x:3x.

     

A generalized theory of particulate electron conduction enzymes applied to cytochrome oxidase. A theory of coupled electron and/or ion transport applied to pyruvate carboxylase

A previously developed theory of particulate electron conduction enzymes was based on a model of an enzyme particle catalyzing the oxidation-reduction of two different substrates at two different enzymatic sites on the same particle with conduction of electrons between the two sites through the enzyme particle. Using the simplifying assumption that the percent reduction of the second substrate is held constant, there was previously shown to be a hyperbolic relationship between the first order rate constant (k′) and the sum (C _x ) of oxidized plus reduced substrate, of the formk′=α/(C _x +β), where α and β are positive constants. It is shown here that if this simplifying assumption is omitted, a positive constant is added to the right hand side of this equation, which describes exactly the experimental data of Smith and conrad on cytochrome oxidase. If electron transport is assumed to be coupled to ion transport, this equation becomesk′=(α/C _x )?γ (where γ is a positive constant) which describes the experimental data of Eadie and Gale on pyruvic carboxylase of yeast. It seems probable that the same theory is applicable to coupled ion-ion transport and coupled electron-electron transport in both membranous systems, and in particulate preparations consisting of membrane fragments.     

The mathematical model of concentration polarization coefficient in membrane transport and volume flows

In this paper, the authors investigate the membrane transport of aqueous non-electrolyte solutions in a single-membrane system with the membrane mounted horizontally. The purpose of the research is to analyze the influence of volume flows on the process of forming concentration boundary layers (CBLs). A mathematical model is provided to calculate dependences of a concentration polarization coefficient (ζ _s ) on a volume flux (J _vm ), an osmotic force (Δπ) and a hydrostatic force (ΔP) of different values. Property ζ _s ?=?f(J _vm ) for J _vm ?>?0 and for J _vm ?≈?0 and property ζ _s ?=?f(ΔC ₁) are calculated. Moreover, results of a simultaneous influence of ΔP and Δπ on a value of coefficient ζ _s when J _vm ?=?0 and J _vm ?≠?0 are investigated and a graphical representation of the dependences obtained in the research is provided. Also, mathematical relationships between the coefficient ζ _s and a concentration Rayleigh number (R _C ) were studied providing a relevant graphical representation. In an experimental test, aqueous solutions of glucose and ethanol were used.     

Measurements of the plasma density in the FTU tokamak by a pulsed time-of-flight X-wave refractometer

On-line control over the plasma density in tokamaks (especially, in long-term discharges) requires reliable measurements of the averaged plasma density. For this purpose, a new method of density measurements—a pulsed time-of-flight plasma refractometry—was developed and tested in the T-11M tokamak. This method allows one to determine the averaged density from the measured time delay of nanosecond microwave pulses propagating through the plasma. For an O-wave, the measured time delay is proportional to the line-averaged density and is independent of the density profile (f?f _p ) τ_o ≈ k _o \(\tfrac{1}{{f^2 }}\mathop \smallint \limits_l \) N(x dx. A similar formula is valid for an X-wave: τ_X = ≈ k _x \(\tfrac{{f^2 + f_c^2 }}{{(f^2 - f_c^2 )^2 }}\mathop \smallint \limits_l \) N(x)dx. Here, f is the frequency of the probing wave, f _p is the plasma frequency, l= 4 a is the path length for two-pass probing in the equatorial plane, a is the plasma minor radius, k _O and k _X are numerical factors, f _c is the electron-cyclotron frequency at the axis of the plasma column, and f _p ?f _c , f. Measurements of the time delay provide the same information as plasma interferometry, though they do no employ the effect of interference. When the conditions f _p ?f _c , f are not satisfied, the measured time delay depends on the shape of the density profile. In this case, in order to determine the average density regardless of the density profile, it is necessary to perform simultaneous measurements at several probing frequencies in order to determine the average density. In ITER (Bt ～ 5T), a spectral window between the lower and upper cutoff frequencies in the range of 50–100 GHz can be used for pulsed time-of-flight X-wave refractometry. This appreciably simplifies the diagnostics and eliminates the problem of the first mirror. In this paper, the first results obtained in the FTU tokamak with a prototype of the ITER pulsed time-of-flight refractometer are presented. The geometry and layout of experiments similar to the planned ITER experiments are described. The density measured by pulsed time-of-flight refractometry is shown to agree well with the results obtained in FTU with a two-frequency scanning IR interferometer. The results obtained are analyzed, and the future experiments are discussed.     

Testing the cost of reproduction with the rotifer <Emphasis Type="Italic">Brachionus</Emphasis><Emphasis Type="Italic">patulus</Emphasis> at different pH levels

In the present work, we tested the hypothesis that the cost of reproduction was evident under stressful conditions with the rotifer Brachionus patulus at different pH levels (5–10 at 1 unit intervals). We used sublethal pH levels (pH 5, 9, and 10) to simulate stressful conditions. We analyzed the correlations between age-specific fecundity (m ₁, m ₂, m ₃, …) versus future survival (l _x + 1, l _x + 2, l _x + 3, … for the entire lifespan) (survival costs) and future expectation of reproduction (\( V_{ 1}^{*} , \, V_{ 2}^{*} , \, V_{ 3}^{*} , \ldots \) for the entire lifespan) (reproductive costs), using the data obtained from life table demographic studies of B. patulus under stressful and favorable (pH 6, 7, and 8) pH levels. The results showed that significant negative correlations were observed between age-specific fecundity and future survival and future expectation of reproduction at all tested pH levels, indicating that costs of reproduction exist in the rotifer B. patulus under stressful and favorable pH conditions. However, the percentage of statistically significant negative correlations from total correlations of survival and reproductive costs differed greatly, depending on the tested pH conditions. The percentage of significant negative correlation of reproductive costs is significantly higher under stressful pH conditions (pH 5, 9, and 10) than favorable pH conditions (pH 6, 7, and 8). For survival costs, the same trends are also observed, suggesting that the costs of reproduction were more obvious under stressful pH than favorable pH.     

Characteristics of a transverse RF discharge in Xe/Cl<Subscript>2</Subscript> mixtures

Results are presented from the study of the electrical and optical characteristics of a transverse RF discharge in Xe/Cl₂ mixtures at pressures of p≤400 Pa. The working mixture was excited by a modulated RF discharge (f=1.76 MHz) with a transverse electrode configuration (L≤17 cm). The emission spectrum in the spectral range of 210–600 nm and the waveforms of the discharge current, discharge voltage, and plasma emission intensity were investigated. The UV emission power from the discharge was studied as a function of the pressure and composition of a Xe/Cl₂ mixture. It is shown that a discharge in a xenon-chlorine mixture acts as planar excimer-halogen lamp operating in the spectral range of 220–450 nm, which contains a system of overlapping XeCl(D, B-X; B, C-A) and Cl₂(D′-A′) bands. Transverse RF discharges in Xe/Cl₂ mixtures can be used to create a wideband lamp with two 50-cm² planar apertures and the low circulation rate of the working mixture.     

Polymorphism of <Emphasis Type="Italic">yellow</Emphasis> locus in <Emphasis Type="Italic">Drosophila melanogaster</Emphasis> mutants from natural populations

We have studied the molecular characteristics of the yellow locus (y; 1–0.0), which determines the body color of phenotypically wild-type and mutant alleles isolated in different years from geographically distant populations of Drosophila melanogaster. According to the Southern blot, data restriction maps of the yellow locus of all examined strains differ from one another, as well as from Oregon stock. FISH analysis shows that, in the neighborhood of the yellow locus in the X chromosome, neither P nor hobo elements are found in y^1–775 stock, while only hobo is found in these region in y^1–859 and y^1–866 stocks, only the P element is found in y⁺sn⁸⁴⁹ stock, and both elements are found in y^1–719 stock. Thus, all yellow mutants studied are of independent origin. Locus yellow located on the end of X chromosome (region 1A5–8 on the cytologic map) carries significantly more transposon than retrotransposon induced mutations compared to the white locus (region 3C2). It is possible that, at the ends of Drosophila melanogaster chromosomes, transposons are more active than retrotransposons.     

Photosynthesis,stomatal conductance and terpene emission response to water availability in dry and mesic Mediterranean forests

Key message

Warmer summer conditions result in increased terpene emissions except under severe drought, in which case they strongly decrease.

Abstract

Water stress results in a reduction of the metabolism of plants and in a reorganization of their use of resources geared to survival. In the Mediterranean region, periods of drought accompanied by high temperatures and high irradiance occur in summer. Plants have developed various mechanisms to survive in these conditions by resisting, tolerating or preventing stress. We used three typical Mediterranean tree species in Israel, Pinus halepensis L., Quercus calliprinos and Quercus ithaburensis Webb, as models for studying some of these adaptive mechanisms. We measured their photosynthetic rates (A), stomatal conductance (g _s), and terpene emission rates during spring and summer in a geophysical gradient from extremely dry to mesic from Yatir (south, arid) to Birya (north, moist) with intermediate conditions in Solelim. A and g _s of P. halepensis were threefold higher in Birya than in Yatir where they remained very low both seasons. Quercus species presented 2–3-fold higher A and g _s but with much more variability between seasons, especially for Q. ithaburensis with A and g _s that decreased 10–30-fold from spring to summer. Terpene emission rates for pine were not different regionally in spring but they were 5–8-fold higher in Birya than in Yatir in summer (P < 0.05). Higher emissions were also observed in Solelim for the drought resistant Q. ithaburensis (P < 0.001) but not for Q. calliprinos. α-Pinene followed by limonene and 3-carene were the dominant terpenes. Warmer summer conditions result in increased Terpene emission rates except under severe drought, in which case they strongly decrease.

     

Heterosis,transmission genetics,and selection for increased growth rate in a <Emphasis Type="Italic">N. tabacum</Emphasis> × synthetic tobacco cross

Cultivated tobacco (Nicotiana tabacum L.) is a classic amphidiploid, and hybrids between this cultivated species and closely related diploid Nicotiana relatives often exhibit heterotic effects for growth rate and yield. Crosses between N. tabacum and synthetic tobaccos, 4x(Nicotiana sylvestris × Nicotiana otophora) or 4x(N. sylvestris × Nicotiana tomentosiformis), may provide superior routes for genome-wide introgression from diploid relatives and allow increased potential to capitalize on heterotic effects in tobacco. Significant levels of mid-parent heterosis were observed for yield and growth rate in F₁ hybrids between synthetic tobaccos and a standard tobacco cultivar. Microsatellite marker genotyping of an F₂ population derived from a K326 × [4x(N. sylvestris × N. otophora)] cross was carried out to preliminarily investigate the relative importance of different types of gene action on observed heterosis in the original interspecific cross. Results suggested a role for both partial dominance and overdominance. Marker genotyping also indicated an overall reduced level of recombination in the N. tabacum × synthetic tobacco cross relative to a N. tabacum × N. tabacum cross but no evidence of genomic regions with severely restricted levels of recombination. Results suggest that populations derived from N. tabacum × synthetic tobacco crosses may be more efficient for introgressing germplasm from diploid relatives, as compared to populations derived from crosses between N. tabacum and diploid forms where preferential pairing between N. tabacum homologues can reduce the potential for introgression of alien chromatin. Such materials may be useful as sources of favorable alleles influencing quantitative characters in tobacco.     

A Polarization Filter Based on Photonic Crystal Fiber with Symmetry Around Gold-Coated Holes

We propose a modified design for a photonic crystal fiber (PCF) polarization filter based on surface plasmon resonance (SPR). The air holes are arrayed in diamond lattices, and the diameter of the holes around the gold-coated holes are different that can separate the refractive index of the x-polarization and y-polarization second order surface plasmon polariton (SPP) modes. The influences of structural parameters of the photonic crystal fiber (PCF) on the filter characteristics are studied using the finite element method (FEM). Great changes have taken place in the results of numerical simulation by changing the thickness of the gold film and air hole diameter. Simulation results show that the resonance wavelength is communication wavelength 1550 mm, the loss of the y-polarization mode is 43,126.7 dB/m. When the length of the fiber is 500 μm, extinction ratio is more than 20 dB at the communication wavelength, and bandwidth achieve to 190 nm. It is an important property of PCF polarization filter in production.     

Evaluation of microbial globin promoters for oxygen-limited processes using <Emphasis Type="Italic">Escherichia coli</Emphasis>

Oxygen-responsive promoters can be useful for synthetic biology applications, however, information on their characteristics is still limited. Here, we characterized a group of heterologous microaerobic globin promoters in Escherichia coli. Globin promoters from Bacillus subtilis, Campylobacter jejuni, Deinococcus radiodurans, Streptomyces coelicolor, Salmonella typhi and Vitreoscilla stercoraria were used to express the FMN-binding fluorescent protein (FbFP), which is a non-oxygen dependent marker. FbFP fluorescence was monitored online in cultures at maximum oxygen transfer capacities (OTR_max) of 7 and 11 mmol L^?1 h^?1. Different FbFP fluorescence intensities were observed and the OTR_max affected the induction level and specific fluorescence emission rate (the product of the specific fluorescence intensity multiplied by the specific growth rate) of all promoters. The promoter from S. typhi displayed the highest fluorescence emission yields (the quotient of the fluorescence intensity divided by the scattered light intensity at every time-point) and rate, and together with the promoters from D. radiodurans and S. coelicolor, the highest induction ratios. These results show the potential of diverse heterologous globin promoters for oxygen-limited processes using E. coli.     

Laboratory modeling of nonstationary processes in space cyclotron masers: First results and prospects

Results are presented from laboratory modeling of the dynamics of space cyclotron masers. A selfoscillatory mode of cyclotron instability in the nonequilibrium plasma of an ECR discharge in a magnetic mirror trap is found. The plasma comprises two electron populations: the background population with a density of N _e ～ 10¹³–10¹⁴ cm^?3 and temperature of T _e ≈ 300 eV and the energetic population with a density of N _e ～ 10¹⁰ cm^?3 and temperature of T _e ≈ 10 keV. Quasi-periodic pulsed precipitation of energetic electrons from the trap, accompanied by microwave bursts at frequencies below the electron gyrofrequency in the center of the trap, is detected. The study of the microwave plasma emission and the energetic electrons precipitated from the trap shows that the precipitation is related to the excitation of whistler-mode waves propagating nearly parallel to the trap axis. The observed instability has much in common with phenomena in space magnetic traps, such as radiation belts of magnetized planets and solar coronal loops. The experimental results demonstrate the opportunity of laboratory modeling of space cyclotron masers. The main tasks and possibilities of such modeling are discussed.