We calculate the evolution of the early universe through the epochs of weak decoupling, weak freeze-out and big bang nucleosynthesis (BBN) by simultaneously coupling a full strong, electromagnetic, ...and weak nuclear reaction network with a multienergy group Boltzmann neutrino energy transport scheme. The modular structure of our code provides the ability to dissect the relative contributions of each process responsible for evolving the dynamics of the early universe in the absence of neutrino flavor oscillations. Such an approach allows a detailed accounting of the evolution of the nu sub(e) nu sub(e), nu sub(mu), nu sub(mu), nu sub(tau), nu sub(tau)energy distribution functions alongside and self-consistently with the nuclear reactions and entropy/heat generation and flow between the neutrino and photon/electron/positron/baryon plasma components. This calculation reveals nonlinear feedback in the time evolution of neutrino distribution functions and plasma thermodynamic conditions (e.g., electron-positron pair densities), with implications for the phasing between scale factor and plasma temperature; the neutron-to-proton ratio; light-element abundance histories; and the cosmological parameter N sub(eff). We find that our approach of following the time development of neutrino spectral distortions and concomitant entropy production and extraction from the plasma results in changes in the computed value of the BBN deuterium yield. For example, for particular implementations of quantum corrections in plasma thermodynamics, our calculations show a 0.4% increase in deuterium. These changes are potentially significant in the context of anticipated improvements in observational and nuclear physics uncertainties.
The ability to determine the spatial distribution of rare fungal species is critical to understanding the environmental factors that affect them. Maximum entropy (MaxEnt) spatial distribution ...modeling solves this problem by allowing inferences about the distribution of species in a gradient of environmental factors based on occurrence data. To identify patterns of spatial distribution based on objective data, models of the potential geographical distribution of the rare polyporoid fungus of
Picipes rhizophilus
under current conditions (~1950–2000) and with predicted future climate changes (2100 AD) on a global scale have been created. The species
Picipes rhizophilus
can develop in steppe habitats of both plains and mountains. Most known habitats of the species are found in the ecoregions that make up the temperate grasslands, savannas and shrublands, Mediterranean forests, woodlands and scrubs, and desert and xeric shrubland biomes. The species is not associated with forest biomes, but it can be found in habitats located on their territory, subject to the processes of climate aridization and desertification. The species
Picipes rhizophilus
can develop in steppe habitats of both plains and mountains. Modeling the potential distribution of the species under the selected climatic scenario has shown the dynamics of changes in its range. The species-friendly climate area will increase in the North American continent, while there will be no significant changes in Europe and adjacent areas of Africa. In the most favorable territory for the species, located in the basin of the Western Manych River, conditions will become less favorable. There will be a local shift in the areas of potential distribution in the Asian part.
For the first time search for tetrodotoxin (TTX) and its analogues in the extracts of nemerteans using HPLC-MS/MS was performed. TTX analogues were detected in two nemertean species in addition to ...TTX: 7 analogues were detected in the extract of Cephalothrix simula, 3 analogues - in the extract 11-norTTX of Kulikovia manchenkoi. Presence of 5-deoxyTTX, 11-deoxyTTX, 5,6,11-trideoxyTTX and −6(R)-ol in nemerteans was shown for the first time.
•TTX and its analogues were first detected in ribbon worms via HPLC-MS/MS.•Four analogues of TTX were revealed in nemertean species for the first time.•5-deoxyTTX (K. manchenkoi) and 5,6,11-trideoxyTTX (C. simula) are dominant toxins.
Cloud condensation nuclei (CCN) concentrations were measured at Egbert, a rural site in Ontario, Canada during the spring of 2007. The CCN concentrations were compared to values predicted from the ...aerosol chemical composition and size distribution using κ-Köhler theory, with the specific goal of this work being to determine the hygroscopic parameter (κ) of the oxygenated organic component of the aerosol, assuming that oxygenation drives the hygroscopicity for the entire organic fraction of the aerosol. The hygroscopicity of the oxygenated fraction of the organic component, as determined by an Aerodyne aerosol mass spectrometer (AMS), was characterised by two methods. First, positive matrix factorization (PMF) was used to separate oxygenated and unoxygenated organic aerosol factors. By assuming that the unoxygenated factor is completely non-hygroscopic and by varying κ of the oxygenated factor so that the predicted and measured CCN concentrations are internally consistent and in good agreement, κ of the oxygenated organic factor was found to be 0.22±0.04 for the suite of measurements made during this five-week campaign. In a second, equivalent approach, we continue to assume that the unoxygenated component of the aerosol, with a mole ratio of atomic oxygen to atomic carbon (O/C) ≈ 0, is completely non-hygroscopic, and we postulate a simple linear relationship between κorg and O/C. Under these assumptions, the κ of the entire organic component for bulk aerosols measured by the AMS can be parameterised as κorg=(0.29±0.05)·(O/C), for the range of O/C observed in this study (0.3 to 0.6). These results are averaged over our five-week study at one location using only the AMS for composition analysis. Empirically, our measurements are consistent with κorg generally increasing with increasing particle oxygenation, but high uncertainties preclude us from testing this hypothesis. Lastly, we examine select periods of different aerosol composition, corresponding to different air mass histories, to determine the generality of the campaign-wide findings described above.
A novel approach to the preparation of imidazole-substituted cyclic iodonium salts has been developed via the oxidative cyclization of 1-phenyl-5-iodoimidazole using a cheap and available Oxone/H
SO
...oxidative system. The structure of the new polycyclic heteroarenes has been confirmed by single-crystal X-ray diffractometry, revealing the characteristic structure features for cyclic iodonium salts. The newly produced imidazole-flanked cyclic iodonium compounds were found to readily engage in a heterocyclization reaction with elemental sulfur, affording benzo5,1-
imidazothiazoles in good yields.
We successfully synthesized bulk Ba
Na
Fe
As
and Sr
Na
Fe
As
compounds by high-energy mechanical alloying (MA) technique. The MA process results in homogeneous amorphous phases of BaFe
As
and SrFe
As
.... It was found that the optimum time for high-energy milling in all cases is about 1.5-2 h, and the maximum amount of amorphous phase could be obtained when energy of 50-100 MJ/kg was absorbed by the powder. After a short-term heat treatment, we obtained nearly optimum sodium-doped Ba
Na
Fe
As
and Sr
Na
Fe
As
superconducting bulk samples. Therefore, MA is a potential scalable method to produce bulk superconducting material for industrial needs.
Tetrodotoxin (TTX) is a potent neurotoxin frequently occurring in marine organisms along with its numerous analogues. To determine the total TTX content, we developed an enzyme-linked immunosorbent ...assay (ELISA) technique utilizing polyclonal antibodies against TTX. The technique was tested using extracts of marine worms of the phylum Nemertea and confirmed by HPLC-MS/MS. It proved to be suitable for a preliminary assessment of the toxicity of marine organisms.
•ELISA technique for quantification of summed TTXs concentration has been developed.•Antibodies against TTXs were obtained by immunization with PHA-TTX conjugate.•The reliability of developed method was confirmed by its comparison with HPLC-MS/MS.
Abstract
Nanomaterials find permanently extending applications in various areas of life. In particular, nanosized phosphors can be used as pharmaceutical carriers capable of emitting ultraviolet or ...visible light that activates a photosensitizer, thus significantly expanding the possibilities of photodynamic therapy in the treatment of oncological, bacterial and viral diseases. The conditions required for the use of nanosized phosphors in medicine include their fine dispersion and effective luminescence in the red region of visible light spectrum upon stimulation by X-ray radiation of the range accepted for medical applications, particularly for diagnostic and therapeutic purposes in many diseases. The aim of this work was to study the effect of microwave treatment of Y
2
O
3
:Eu phosphors prepared by hydrothermal synthesis in ethylene glycol at 230 °C for 6 hours, involving the decomposition of mixed acetate. In order to reduce the aggregation and growth of the resulting particles, Aerosil A300 with average particle size 7 nm was added to the reaction mixture in the course of hydrothermal synthesis in the ratio 1:1 relating to the obtained phosphor. The microwave treatment was carried out at 800 °C for 5 minutes. The developed method provided Y
2
O
3
:Eu phosphor samples featuring with increased luminescence intensity in the region 610…700 nm compared to similar phosphors earlier prepared using the rapid thermal annealing (RTA) procedure.
In pnictide RbEuFe4As4, superconductivity sets in at 36 K and coexists, below 15–19 K, with the long-range magnetic ordering of Eu 4f spins. Here we report scanning tunneling experiments performed on ...cold-cleaved single crystals of the compound. The data revealed the coexistence of large Rb-terminated and small Eu-terminated terraces, both manifesting 1 × 2 and 2 × 2 reconstructions. On 2 × 2 surfaces, a hidden electronic order with a period ∼5 nm was discovered. A superconducting gap of ∼7 meV was seen to be strongly filled with quasiparticle states. The tunneling spectra compared with density functional theory calculations confirmed that flat electronic bands due to Eu 4f orbitals are situated ∼1.8 eV below the Fermi level and thus do not contribute directly to Cooper pair formation.
The taxonomic diversity of epiphytic myxomycetes depending on the height of the trunk on living woody plants in the arboretum of the Central Siberian Botanical Garden, Siberian Branch, Russian ...Academy of Sciences (CSBG SB RAS), has been studied. All samples of myxomycetes are obtained by cultivation by the method of moist chambers in the laboratory in Petri dishes. Sampling of bark from living woody plants is carried out at a height of trunks from 0 to 15 m from the soil level. The experiment involves nine species of introduced deciduous woody plants
Fraxinus pennsylvanica, Prunus maackii, Populus alba, Salix alba, S. pentandra, S. triandra, Sorbus aucuparia, Tilia cordata,
and
Jungles mandshurica
. As a result of data analysis, 51 species of myxomycetes are revealed. It is noted that the species composition of myxomycetes on the studied woody plants differs significantly from that on native tree species growing on the territory of the botanical garden. Two species of the genus
Arcyria
and
Trichia
new for science, 3 species new to Russia (
Didymium clavodecus
,
D. ovoideum
, and
D. synsporon
), and 18 species new for Novosibirsk Region have been identified. A description of species new to science is given; photographs of sporocarps, spores, and capillitium studied using light and scanning electron microscopy are provided; and a comparison with morphologically similar species is made. A change in the taxonomic composition of myxomycete communities depending on the height of the trunk is established. On the bark collected at the roots of trees, 25 species of myxomycetes have been identified; at a height of 1.5 m, 18; at a height of 5 m, 32; at a height of 10 m, 14; and, at a height of 15 m, 17. Representatives of the genus
Perichaena
are found at all heights, but the greatest species diversity is noted in the basal part, where seven species are noted, while species of the genus
Didymium
have the maximum species diversity (six species) at a height of 5 m, including three species new to Russia, noted only at this height. The distribution of the number of samples by height showed that the bark of living woody plants is most abundantly populated at a height of 5 m (72 samples) and at the root (50 samples).
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