•Line coupling and line mixing in CH3I spectra perturbed by N2 and O2 have been calculated.•The semi-classical method correctly takes into account the k-degeneracy of the transitions.•It leads to a ...reasonable agreement with the available data, including the T-dependence.•New experiments at higher pressures are suggested to check the description of inter-doublets couplings.
Calculations of the N2-, O2-, and air-broadened widths, together with their temperature dependence exponents have been made for transitions of CH3I in the ν5 and ν6 bands. The calculations are based on a semi-classical line shape formalism developed by the current authors through modifying and refining the Robert-Bonamy formalism. In recent years, we have applied this formalism for linear molecules, symmetric-top molecules with inversion symmetry, and asymmetric-top molecules. For symmetric-top molecules with the k degeneracy such as CH3I, the formalism has a new feature. In this case, one should consider each of the CH3I transitions labeled by ki or f ≠ 0 as a doublet. Then, one needs to consider the effects of the line mixing process between these two components. Comparisons of our theoretical predictions with some data available demonstrate a very reasonable agreement. Finally we propose new experiments at higher perturber pressures that would enable one to check the theoretically calculated relaxation matrices and to extend the analysis to the inter-doublet mixing effects.
Light‐harvesting chlorophyll a/b binding (Lhc) family proteins play a significant role in photosynthetic processes. Our objective was systematic identification and analysis of the Lhc family in ...cotton, as well as the relationship between Lhc family genes and chlorophyll synthesis during photosynthetic processes.
We used genome‐wide identification, phylogenetic analysis, chromosomal distribution and collinearity to examine potential functions of Lhc superfamily genes in upland cotton. Subcellular localization, qRT‐PCR, a yeast two hybrid (Y2H) , and Virus‐induced gene silencing (VIGS) experiment were used to explore function of GhLhcb2.3.
Focusing on GhLhc family, gene structural analysis of G. hirsutum Lhc family genes (GhLhc) indicated the conservation of selected Lhc family members. The expression pattern of GhLhc proteins shows that Lhc family proteins are important for photosynthetic processes in leaves. Results of subcellular localization and qRT‐PCR in different cotton varieties showed that GhLhcb2.3 is closely related to chloroplast chlorophyll. Y2H found extensive heteromeric interactions between the GhLhcb2.3 and GhLhcb1.4. Subcellular localization revealed that GhLhcb1.4 is located in chloroplasts. VIGS showed that GhLhcb2.3 influenced chlorophyll a synthesis.
We comprehensively identified Lhc family genes in cotton, characterized these genes and reveal the influence of GhLhcb2.3 on chlorophyll a synthesis.
In this study, we investigated the genome‐wide identification, phylogenetic analysis, chromosomal distribution, and collinearity analysis for the Lhc superfamily regarding the potential functions of the Lhc superfamily genes in cotton.
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•Potential of rice plant to reduce bioavailable As in soils was investigated.•Unique rhizosphere biochemistry of rice plant favors efficient soil As removal.•Rice growth decreased ...rhizosphere DGT-As below the target level.•Root As accumulation accounted for 95% of total As in rice plant.•Removing rice roots was effective in attenuating bioavailable As in paddy soils.
Rice plant is efficient in arsenic (As) accumulation due to enhanced soil As release under flooded condition and its effective As uptake. Therefore, rice plant can be used to remove bioavailable As from paddy soil. In this study, the depleting dynamics of soil As with rice growth was mapped two-dimensionally with the zirconium-oxide diffusive gradients in thin films (DGT) technique. Further, the key biochemistry promoting soil As bioavailability was studied to better understand the underlying processes. Results revealed that the average DGT-As encompassing the root zone decreased steeply from 331 in the seedling stage to 136 in the heading & flowering stage and further to 118 μg l−1 at harvest, which was 26% lower than that of the control at 160 μg l−1. During this process, rhizosphere porewater As developed a dynamic profile similar to Fe and dissolved organic carbon, with the diversity of arrA gene peaking at heading & flowering stage. The data support soil As release from microbial reduction of Fe hydroxides fueled by root exudation as carbon source. Arsenic was mainly accumulated in the roots, accounting for up to 95% of total As in rice plants. Removal of rice roots resulted in ~19% lower DGT-As in post-harvest soil compared to without removing the roots. As a result, a sharp decline in As accumulation in rice plants was obtained in the second planting after removing one crop of rice roots. The results highlight that rice, as a paddy-adapted plant, is effective in As uptake in the roots, and thereby removing rice roots efficiently depletes bioavailable As from paddy soils.
Based on the theory of wave propagation in unsaturated poroelastic medium and elastic medium, the vibration isolation performance of the wave impeding block (WIB) in unsaturated soil foundation under ...S-wave incidence is studied. A free field model for setting WIB in unsaturated soil is established by using the Helmholtz principle, and the solutions of vertical displacements of the unsaturated soil foundation under S-wave incidence are obtained. The effects of mechanical parameters such as the angle of incidence, frequency of incidence, saturation, shear modulus, thickness, and depth on the vibration isolation effect of WIB in unsaturated soil foundation are investigated. The results show that the angle of incidence under S-wave incidence has a significant effect on the vibration isolation effect of the WIB in unsaturated ground, and the angle of WIB should be adjusted appropriately to avoid the incidence angle corresponding to the peak displacement in order to obtain a better vibration isolation effect. Saturation has a significant effect on the vibration isolation effect of the WIB, and the vibration isolation effect of the WIB increases with the increase in saturation. The vibration isolation effect of the WIB increases with the increase in its shear modulus. In a specific range of incident angle the vibration isolation effect will be increased with the increasing of thickness.
Accurately modeling the evolution of the electron radiation belts within the plasmasphere represents both an imperative goal for space weather forecasting and a great challenge. Combining previously ...developed approximate analytical expressions of electron lifetimes with recent statistical models of plasma density, ULF, whistler‐mode, and electromagnetic ion cyclotron waves, we demonstrate that geomagnetic activity and plasma density actually govern the inner structure of the radiation belts through several simple analytical scaling laws when Kp < 3. Many of the observed characteristic features of electron fluxes in the energy versus L shell parameter space are straightforwardly explained. In particular, the upper energy limit of significant electron fluxes at L = 1.5 is estimated as ∼1 MeV in agreement with recent satellite observations. This approximate analytical model represents a very simple and powerful tool for exploring and better understanding the complex variations of the inner structure of the radiation belts with geomagnetic activity during relatively quiet times.
Key Points
Approximate analytical scaling laws for the inner structure of the radiation belts based on multiple waves and plasma density statistics
Scaling laws agree with measured electron lifetimes and electron flux (E, L) distributions from the Van Allen Probes
Geomagnetic activity and plasmaspheric density are governing the inner structure of the radiation belts through simple scaling laws
Oriental river prawn (Macrobrachium nipponense) has been widely cultured in Asian countries. However, its nutritional studies are very limited. In the present 8‐week study, we investigated the ...effects of dietary protein to energy ratio (P/E ratio) on the growth, feed utilization and body composition in juvenile M. nipponense (initial weight 0.302 ±0.03 g). Two‐factor experiment was designed and nine semi‐purified diets were formulated to contain three lipid levels (20, 80 and 140 g kg−1) and three protein levels (330, 380 and 430 g kg−1), producing P/E ratios from 16.5 to 23.4 mg KJ−1 protein. The results indicated that the growth, survival rate and protein efficiency were dose dependently improved by the increased dietary lipid, but not dietary protein content. Increased dietary lipid content and/or protein content increased lipid accumulation in whole body, hepatopancreas and muscle, but did not change the feed intake and hepatopancreas weight. In conclusion, our present study indicated that M. nipponense is a species with relatively high‐energy requirement. It could utilize dietary lipid content up to 140 g kg−1, while the dietary protein with more than 330 g kg−1 would not promote growth and protein efficiency. Taken together, 330 g kg−1 dietary protein and 140 g kg−1 dietary lipid level with P/E ratio 16.49 could be optimum for M. nipponense.
Contamination of heavy metals represents one of the most pressing threats to water and soil resources as well as human health. Phytoremediation can be potentially used to remediate metal-contaminated ...sites. This study evaluated the potential of 36
plants (17
species) growing on a contaminated site in North Florida. Plants and the associated soil samples were collected and analyzed for total metal concentrations. While total soil Pb, Cu, and Zn concentrations varied from 90 to 4100, 20 to 990, and 195 to 2200
mg kg
−
1
, those in the plants ranged from 2.0 to 1183, 6.0 to 460, and 17 to 598
mg kg
−
1
, respectively. None of the plants were suitable for phytoextraction because no hyperaccumulator was identified. However, plants with a high bioconcentration factor (BCF, metal concentration ratio of plant roots to soil) and low translocation factor (TF, metal concentration ratio of plant shoots to roots) have the potential for phytostabilization. Among the plants,
Phyla nodiflora was the most efficient in accumulating Cu and Zn in its shoots (TF
=
12 and 6.3) while
Gentiana pennelliana was most suitable for phytostabilization of sites contaminated with Pb, Cu and Zn (BCF
=
11, 22 and 2.6). Plant uptake of the three metals was highly correlated, whereas translocation of Pb was negatively correlated with Cu and Zn though translocation of Cu and Zn were correlated. Our study showed that native plant species growing on contaminated sites may have the potential for phytoremediation.
As a major component of the cell wall, lignin has been suggested to play an important role in the plant defence response to various pathogens. However, how lignin is involved in plant pathogen ...interaction is still unclear. Here, a series of transgenic tobacco lines were cultivated with a range of differences in lignin content and composition. Evaluation of pathogen resistance in these plants indicated that lower total lignin content aggravated the severity of tobacco black shank and bacterial wilt diseases, while increased sinapyl lignin (S) alleviated the disease symptoms. The regression analysis indicated both lignin content and S lignin were positively correlated with disease resistance. These two factors had additive effects, exhibiting stronger correlation with disease resistance when they were combined. Neither guaiacyl lignin (G) nor S/G ratio showed close correlation with disease resistance. The expression of pathogenesis‐related protein genes PR2 and PR3 was induced after pathogen inoculation. However, the up‐regulation of PR2 and PR3 was not associated with a disease resistance‐induced increase in lignin content. These data collectively suggest that both total lignin content and S lignin are main factors that contribute to the basic defence response in tobacco.
Optical waveguide (OWG) sensors present great potential for detecting trace levels of harmful gases because of their high sensitivity and anti-electromagnetic interference. However, OWG-based SO2 and ...H2S-detecting sensors in the parts-per-trillion (ppt) range are still lacking. We fabricated 5,10,15,20-(tetra-4-aminophenyl) porphyrin (TAPP) thin film-based OWG sensor devices (TAPP-OWG) to detect SO2 and H2S gases, in which TAPP thin film was immobilized over the surface of a potassium ion exchange glass OWG. These sensors successfully measure extremely low concentrations of SO2 and H2S (detection limit = 1 ppt), providing good repeatability for SO2 (10 ppt) and H2S (10 ppt) gases, with relative standard deviations of 1.67% and 3.68%, respectively. With fast response (t1) and recovery (t2) times for SO2 (t1=4 s, t2=157 s) and H2S (t1=2 s, t2=117 s) at room temperature, TAPP thin film enhances the potential of OWGs for use in high-sensitivity trace-level gas detection.
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