Predicting Population Status of Gum and Resin Bearing Plant Species from Size Distributions in Benishangul Gumuz Regional State, Ethiopia: Inferences for Their Sustainable Management

Diversity, population structures, and regeneration status of gum- and resin-producing woody species, were assessed in 116 sample plots, each measuring 400 m2 and established along line transects. The data were collected in two selected districts, namely, Sherkole and Kurmuk in Benishangul-Gumuz National Regional State, one of the gums and resin belts in western Ethiopia. The gum- and resin-producing woody species had 1.04 and 0.7 diversity and 0.576 and 0.49 evenness values at Kurmuk and Sherkole districts, respectively. They accounted for 26% and 46% of the density, 51% and 58% of the basal area, and 32% and 53% of the Importance Value Index of all the woody species, respectively. The gum- and resin-bearing woody species exhibited three patterns of population structure. The first pattern suggests good reproduction abilities of the species coupled with a good recruitment of seedlings and their subsequent continuous growth to replace older individuals over time, indicating stable regeneration. About 61% of the gum- and resin-bearing woody species fall under this category. The other two patterns indicate the hampered regeneration status of the woody species. Heavy grazing, conversion to cropland by small-scale farming, gold mining, recurrent fire, and climate change were mentioned as major bottlenecks of natural regeneration and recruitment. Policy, extension, and research recommendations are discussed.

Predicting population status of gum and resin bearing plant species from size distributions in Benishangul Gumuz Regional State, Ethiopia: Inferences for their sustainable management

Diversity, population structures and regeneration status of gum- and resin- producing woody species, were assessed in 116 sample plots, each measuring 400 m2 and established along line transects. The data were collected in two selected districts, namely, Sherkole and Kurmuk in Benishangul-Gumuz National Regional State, one of the gum and resin belts in western Ethiopia. The gum- and resin-producing woody species had 1.04 and 0.7 diversity and 0.576 and 0.49 evenness values at Kurmuk and Sherkole districts, respectively. They accounted for 26% and 46% of the density, 51% and 58% of the basal area and 32% and 53% of the Importance Value Index of all the woody species, respectively. The gum- and resin- bearing woody species exhibited three patterns of population structure. The first pattern suggests good reproduction abilities of the species coupled with good recruitment of seedlings and their subsequent continuous growth to replace older individuals over time, indicating stable regeneration. About 61% of the gum- and resin- bearing woody species fall under this category. The other two patterns indicate hampered regeneration status of the woody species. Heavy grazing, conversion to crop land by small scale farming, gold mining, recurrent fire and climate change were mentioned as major bottlenecks of natural regeneration and recruitment. Policy, extension and research recommendations are discussed.

The Effects of Forcing Direction on the Flame Transfer Function of a Lean-Burn Spray Flame

The flame transfer function (FTF) of an industrial lean-burn fuel injector has been computed using large eddy simulation (LES) and compared to experimental measurements using the multi-microphone technique and OH* measurements. The flame transfer function relates the fluctuations of heat release in the combustion chamber to fluctuations of airflow through the fuel injector and is a critical part of thermoacoustic analysis of combustion systems. The multi-microphone method derives the FTF by forcing the flame acoustically, alternating from the upstream and downstream side. Simulations emulating this methodology have been completed using compressible large eddy simulations (LES). These simulations are also used to derive an FTF by measuring the fluctuations of mass flow rate and heat release rate directly which reduces the number of simulations per frequency to one, significantly reducing the simulation cost. Simulations acoustically forced from downstream are shown to result in a lower value of the FTF gain than simulations forced from upstream with a small change in phase, this is shown to be consistent with theory. Through using a slightly different definition of the FTF, this is also shown to be consistent with measurements of the heat release rate using OH* chemiluminescence however these results are inconsistent with the multi-microphone method result. The discrepancy comes from not having an accurate measurement of the acoustic impedance at the exit plane of the injector and from certain convective phenomena that alter the downstream velocity and pressure field with respect to the purely acoustic signal. All simulations show a lower gain in the FTF than the experiments but with good reproduction of phase. Previous work suggests this error is likely due to fluctuations of the fuel spray atomisation process due to the acoustic forcing which is not modelled in this study.

Results of a comprehensive study of water bioresources of lake Senezh

In the paper, preliminary results of hydrochemical, hydrobiological, parasitological and ichthyological investigations have been given, carried out on waters of the Lake Senezh in 2020 and compared with analogous works for 2004–2006. The ecosystem of the given water object is extremely understudied. In the size structure of fish species, caught in 2020, dynamics of a good reproduction potential could be noted. The condition factor of all fish species is very high. One can see a significant prevalence of females over males, excepting bream, in all fish groups studied. The water object investigated showed the 2,8 times MPC increase for iron in fish farming water bodies. Concentration of toxic elements in water samples and bottom sediments did not increase MPC for all other indices. The bacteriological water analysis showed insignificant increase of bacterial contamination at the area of the investigation station 6 only, what is most likely of the anthropogenic nature and is being a result of the littoral lake zone pollution. Parasitological analysis of the Senezh lake fishes indicates of o high level of their invasion. 11 parasites species were found in 3 fish species investigated, which were represented by 73% of trematodes at the metacercaria and maritas stage. The fish ergasiles problem, existed in this water body since 2005 and up to-date, continues. In zanders gills, parasitic Ergasilus sieboldin were found. The given work would be interesting for investigators who will study the Senezh lake as well as other water bodies of the Moscow area.

Observations in statistically homogeneous, locally inhomogeneous cosmological toy models without FLRW backgrounds

ABSTRACT We study observations in toy models that constitute exact cosmological solutions to the Einstein equation. These models are statistically homogeneous but locally inhomogeneous, without an a priori introduced Friedmann–Lemaître–Roberston–Walker (FLRW) background and with ‘structures’ evolving fairly slowly. The mean redshift–distance relation and redshift drift along 500 light rays in each of two models are compared with relations based on spatial averages. The relations based on spatial averages give a good reproduction of the mean redshift–distance relation, although most convincingly in the model where the kinematical backreaction and average spatial curvature cancel each other to a subpercentage precision. In both models, the mean redshift drift clearly differs from the drift of the mean redshift. This indicates that redshift drift could be an important tool for testing the backreaction conjecture as redshift drift appears to distinguish between local and global effects. The method presented for computing the redshift drift is straightforward to generalize and can thus be utilized to fairly easily compute this quantity in a general space–time.

Towards an algebraic method of solar cycle prediction

An algebraic method for the reconstruction and potentially prediction of the solar dipole moment value at sunspot minimum (known to be a good predictor of the amplitude of the next solar cycle) was suggested in the first paper in this series. The method sums up the ultimate dipole moment contributions of individual active regions in a solar cycle: for this, detailed and reliable input data would in principle be needed for thousands of active regions in a solar cycle. To reduce the need for detailed input data, here we propose a new active region descriptor called ARDoR (Active Region Degree of Rogueness). In a detailed statistical analysis of a large number of activity cycles simulated with the 2 × 2D dynamo model we demonstrate that ranking active regions by decreasing ARDoR, for a good reproduction of the solar dipole moment at the end of the cycle it is sufficient to consider the top N regions on this list explicitly, where N is a relatively low number, while for the other regions the ARDoR value may be set to zero. For example, with N = 5 the fraction of cycles where the dipole moment is reproduced with an error exceeding ±30% is only 12%, significantly reduced with respect to the case N = 0, i.e. ARDoR set to zero for all active regions, where this fraction is 26%. This indicates that stochastic effects on the intercycle variations of solar activity are dominated by the effect of a low number of large “rogue” active regions, rather than the combined effect of numerous small ARs. The method has a potential for future use in solar cycle prediction.

Defect Chemistry, Sodium Diffusion and Doping Behaviour in NaFeO2 Polymorphs as Cathode Materials for Na-Ion Batteries: A Computational Study

Minor metal-free sodium iron dioxide, NaFeO2, is a promising cathode material in sodium-ion batteries. Computational simulations based on the classical potentials were used to study the defects, sodium diffusion paths and cation doping behaviour in the α- and β-NaFeO2 polymorphs. The present simulations show good reproduction of both α- and β-NaFeO2. The most thermodynamically favourable defect is Na Frenkel, whereas the second most favourable defect is the cation antisite, in which Na and Fe exchange their positions. The migration energies suggest that there is a very small difference in intrinsic Na mobility between the two polymorphs but their migration paths are completely different. A variety of aliovalent and isovalent dopants were examined. Subvalent doping by Co and Zn on the Fe site is calculated to be energetically favourable in α- and β-NaFeO2, respectively, suggesting the interstitial Na concentration can be increased by using this defect engineering strategy. Conversely, doping by Ge on Fe in α-NaFeO2 and Si (or Ge) on Fe in β-NaFeO2 is energetically favourable to introduce a high concentration of Na vacancies that act as vehicles for the vacancy-assisted Na diffusion in NaFeO2. Electronic structure calculations by using density functional theory (DFT) reveal that favourable dopants lead to a reduction in the band gap.

Fat SIRAH: Coarse-grained phospholipids to explore membrane-protein dynamics

ABSTRACTTne capability to handle highly heterogeneous molecular assemblies in a consistent manner is among the greatest challenges faced when deriving simulation parameters. This is particularly the case for coarse-grained simulations in which chemical functional groups are lumped into effective interaction centers for which transferability between different chemical environments is not guaranteed. Here we introduce the parameterization of a set of CG phospholipids compatible with the latest version of the SIRAH force field for proteins. The newly introduced lipid species include different acylic chain lengths, partial unsaturation, as well as polar and acidic head groups that show a very good reproduction of structural membrane determinants, as areas per lipid, thickness, order parameter, etc., and their dependence with temperature. Simulation of membrane proteins showed unprecedented accuracy in the unbiased description of the thickness-dependent membrane-protein orientation in systems where this information is experimentally available (namely, the SarcoEndoplasmic Reticulum Calcium –SERCA-pump and its regulator Phospholamban). The interactions that lead to this faithful reproduction can be traced down to single amino acid-lipid interaction level and show full agreement with biochemical data present in the literature. Finally, the present parameterization is implemented in the GROMACS and AMBER simulation packages facilitating its use to a wide portion of the Biocomputing community.

New Sellmeier and Thermo-Optic Dispersion Formulas for AgGaS2

This paper reports on the new Sellmeier and thermo-optic dispersion formulas that provide a good reproduction of the temperature-dependent phase-matching conditions for second-harmonic generation (SHG) and sum-frequency generation (SFG) of a CO2 laser and a Nd:YAG laser-pumped KTiOPO4 (KTP) optical parametric oscillator (OPO) in the 0.8859–10.5910 μm range as well as those for difference-frequency generation (DFG) between the two diode lasers in the 4.9–6.5 μm range and DFG between the two periodically poled LiNbO3 (PPLN) OPOs in the 5–12 μm range thus far reported in the literature.

Ecobiological study of Artemia salina L. and first determination of the toxicity of ammonium sulphate

The objective of this work is firstly an ecobiological study, which aims to determine whether salinity is favorable for a good reproduction rate of cysts in the Artemia salina L., a species known for its use in aquaculture. Secondly, a short-term test of ammonium sulfate toxicity on its vitality is carried out as its environment is permanently subjected to sulphate-laden waste. The work consists of subjecting the species to different salinities in order to produce a good yield in cysts, which once recovered, hatching and breeding is maintained until individuals reach the adult stage. A toxicological study using toxicity test (CL50) is then conducted to study the resistance of these adults with various concentrations of ammonium sulphate. The results obtained from the ecobiological study show a mean similar to the natural environment (p > 0.05) with a favorable concentration for the reproduction of the species at a salinity of about 75 g dm−3. The toxicity test indicates a CL50 equal to 75 mg dm−3 after 24 hours. It is obvious that Artemia salina L. can be cultivated by controlling its reproduction by varying the salinity rate for its use during different seasons of the year, thus ammonium sulphate from waste is considered as a limiting factor.