Gene transfer between species during interspecific hybridization is a widely accepted reality in plants but is considered a relatively rare phenomenon among animals. Here we describe a unique case of ...mitochondrial DNA (mtDNA) paraphyly in the skipper genus, Erynnis, that involves well-diverged allopatric species. Using molecular evidence from both mitochondrial and nuclear genomes, we found high levels of intraspecific divergence in the mitochondrial genome within E. propertius (over 4% pair-wise sequence divergence) but no such differentiation in the nuclear genome. Sequence comparisons with related Erynnis suggest that past, but recent and infrequent introgression between E. propertius and E. horatius is the most reasonable explanation for the observed pattern of mtDNA paraphyly. This example of putative introgression highlights the complexity of mtDNA evolution and suggests that similar processes could be operating in other taxa that have not been extensively sampled. Our observations reinforce the importance of involving multiple genes with different modes of inheritance in the analysis of population history of congeneric taxa.
Abstract
Background
Traditional biomonitoring approaches have delivered a basic understanding of biodiversity, but they cannot support the large-scale assessments required to manage and protect ...entire ecosystems. This study used DNA metabarcoding to assess spatial and temporal variation in species richness and diversity in arthropod communities from 52 protected areas spanning 3 Canadian ecoregions.
Results
This study revealed the presence of 26,263 arthropod species in the 3 ecoregions and indicated that at least another 3,000–5,000 await detection. Results further demonstrate that communities are more similar within than between ecoregions, even after controlling for geographical distance. Overall α-diversity declined from east to west, reflecting a gradient in habitat disturbance. Shifts in species composition were high at every site, with turnover greater than nestedness, suggesting the presence of many transient species.
Conclusions
Differences in species composition among their arthropod communities confirm that ecoregions are a useful synoptic for biogeographic patterns and for structuring conservation efforts. The present results also demonstrate that metabarcoding enables large-scale monitoring of shifts in species composition, making it possible to move beyond the biomass measurements that have been the key metric used in prior efforts to track change in arthropod communities.
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Reducing potassium permanganate by a carbon matrix (multiwalled carbon nanotubes (MWCNTs)) in aqueous solutions, we have obtained Mn
x
O
y
/MWCNT nanostructured composites (NSCs). The morphology ...and texture of the MWCNTs and NSCs have been studied by X-ray diffraction, small angle X-ray scattering (SAXS), sorption porosimetry (SP), scanning electron microscopy, and transmission electron microscopy (TEM) with the aim of assessing the effect of the Mn
x
O
y
filler on their properties and the electrical capacitance characteristics of composite electrodes in model supercapacitor (SC) cells. Comparison of the TEM, SAXS, and SP results indicates that the MWCNTs have narrow distributions of the channel diameter (2–5 nm), outer diameter (18–23 nm), and wall thickness (2–12 nm). In addition, nanotube entanglements (“fibers”) form meso- and macropores (20–80 nm), probably slit-shaped. The filler particles in the NSCs have the form of nanometer-thick quasi-films of Mn
2
O
3
and MnO
2
nanocrystallites and aggregates on the surface of the inner channels, accessible to the electrolyte, and on the outer surface of the MWCNTs and partially block the MWCNT channels. The aggregate size and the blocking of channels and mesopores increase with increasing NSC preparation temperature and Mn
x
O
y
filler content. The electrical capacitance of the NSCs in a potential window of ±1 V exceeds the capacitance of the MWCNTs owing to the contribution of the pseudocapacitance during redox processes involving Mn
x
O
y
on the surface of the NSCs. At an optimal filler content (about 5 wt % in terms of Mn), the capacitance of NSC electrodes exceeds that of MWCNT electrodes by a factor of 1.5 (at
v
= 10 mV/s) and 2.5 (at
v
= 80 mV/s).
A complete Hamiltonian formalism is suggested for inertial waves in rotating incompressible fluids. Resonance three-wave interaction processes – decay instability and confluence of two waves – are ...shown to play a key role in the weakly nonlinear dynamics and statistics of inertial waves in the rapid rotation case. Future applications of the Hamiltonian approach to inertial wave theory are investigated and discussed.
Two polymorphs of tolazamide, N-(azepan-1-ylamino)carbonyl-4-methylbenzenesulfonamide, a sulfonylurea anti-diabetic drug, have different densities and molecular packings. Polymorph II converts into ...polymorph I in the solid state on heating or via recrystallization if solvent-assisted. The effect of pressure on the two forms and the possibility of a transformation to a denser form on compression have been studied. No phase transitions have been observed in either of the forms in a pentane-isopentane mixture (when no recrystallization is possible). Polymorph II recrystallized partly into a denser polymorph I in methanol at 0.1 GPa, but the transformation stopped at an early stage. Solid state DFT calculations of the two forms as well as conformational landscape investigation in the gas phase were used to rationalize this result. The anisotropic pressure-induced strain of the two polymorphs has been compared in relation to changes in the hydrogen bond geometry and the behavior of stacking interactions.
In spite of well-known mechanisms of iron consumption by plants from the soil and action patterns of iron ions in the soils, the work to eliminate the deficiency of this trace element in plants is ...still relevant. The article presents an assessment of the effect of iron (III) chelate complexes with diethylenetriaminepentaacetic acid (DTPА Fe) and ethylenediaminetetraacetic acid (EDTA Fe) on the mobility and availability of iron for plants in soil with a pH close to neutral. In a model experiment with using of drainage columns, there were established the patterns of iron distribution in the soil and its removal with irrigation water from the root zone of plants (10 cm). Against the background of similar distribution of iron in the soil, a higher content of its mobile forms in the lower layers was noted when using EDTA Fe. The leaching of iron from the soil was confirmed using both DTPA Fe and EDTA Fe. The vegetation experiment revealed the effect of chelate forms on the accumulation of iron in barley plants (Hordeum vulgare L.) during their early growth period (11 days). The iron content in the shoots varied from 120 to 140 µg/g, in the roots – from 233 to 244 µg/g, with a content of 200 µg/g in the control sample. A significant contribution to the accumulation of iron in barley seedlings was observed at the level of the root system in the experiment with EDTA Fe. Data on the accumulation of iron in barley roots were correlated (r = 0.99) with data on their ash content.
Numerical Study of Isotropic Ocean Swell Geogjaev, V. V.; Zakharov, V. E.; Badulin, S. I.
Doklady earth sciences,
12/2019, Letnik:
489, Številka:
2
Journal Article
Recenzirano
A new algorithm is used for detailed numerical study of the evolution of isotropic swell in a homogeneous ocean. It is shown that the Zakharov-Filonenko spectrum occurs in an explosive manner in a ...short time. The Kolmogorov constant of the solution is estimated numerically.
We determine the asymptotic behavior of the coupling coefficient for four-wave interactions of gravity waves in deep water in the limiting case when two wave vectors of interacting waves are small ...with respect to the other two (“long–short interactions”). It makes possible to find numerically dimensionless Kolmogorov constants for the power-law Kolmogorov–Zakharov spectra. The results obtained are crucially important for comparison of the weak turbulent theory with the experiments and natural observations.
Granular LTA and SOD zeolites have been synthesized, characterized, and further used to study the kinetics of water adsorption and desorption. It has been shown that LTA zeolite in a static mode ...provides adsorption of water vapor at the level of ~30 wt % for LTA and ~20 wt % for SOD. It has been found that during water adsorption from the gas phase on the LTA or SOD zeolite in a flow-through unit, the dew point reaches –50 or –9°С, respectively. The kinetics of adsorption of water vapor on zeolite granules has been studied; the values of apparent activation energy of the adsorption process have been calculated, which amount to about 50 kJ mol
–1
; and the rate order of the process has been determined (0.2 for LTA and 0.9 for SOD). The apparent activation energies for water desorption from the zeolites have been calculated by isoconversional analysis in terms of the Friedman, Ozawa–Flynn–Wall, and Kissinger–Akahira–Sunose models. It has been shown that all three models give similar results. It has been found that at given degree of conversion, the activation energies are not higher than 60 kJ mol
–1
, a value that corresponds to desorption of physically bound water. The increase in activation energy to 110 kJ mol
–1
(for SOD) or 80 kJ mol
–1
(for LTA) is associated with the removal of water from the α- and β-cages of zeolites.
We calculate the rate of ocean wave energy dissipation due to white capping by numerical simulation of deterministic phase resolving model for dynamics of ocean surface. Two independent numerical ...experiments are performed. First, we solve the 3D Hamiltonian equation that includes three- and four-wave interactions. This model is valid only for moderate values of the surface steepness, μ < 0.09. Then we solve the exact Euler equation for non-stationary potential flow of an ideal fluid with a free surface in 2D geometry. We use the conformal mapping of domain filled with fluid onto the lower half-plane. This model is applicable for arbitrary high levels of the steepness. The results of both experiments are close. The white capping is the threshold process that takes place if the average steepness μ > μ
cr
≃ 0.055. The rate of energy dissipation grows dramatically with increasing steepness. Comparison of our results with dissipation functions used in the operational models of wave forecasting shows that these models overestimate the rate of wave dissipation by order of magnitude for typical values of the steepness.
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