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.
Following the discovery of the gravitational-wave source GW170817 by three Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo antennae (Abbott et al., 2017a), the MASTER Global Robotic ...Net telescopes obtained the first image of the NGC 4993 host galaxy. An optical transient, MASTER OTJ130948.10-232253.3/SSS17a was later found, which appears to be a kilonova resulting from the merger of two neutron stars (NSs). Here we describe this independent detection and photometry of the kilonova made in white light, and in B, V, and R filters. We note that the luminosity of this kilonova in NGC 4993 is very close to those measured for other kilonovae possibly associated with gamma-ray burst (GRB) 130603 and GRB 080503.
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.
Abstract
This article presents the early results of synchronous multiwavelength observations of one of the brightest gamma-ray bursts (GRBs) GRB 160625B with the detailed continuous fast optical ...photometry of its optical counterpart obtained by MASTER and with hard X-ray and gamma-ray emission, obtained by the Lomonosov and Konus-Wind spacecraft. The detailed photometry led us to detect the quasi-periodical emission components in the intrinsic optical emission. As a result of our analysis of synchronous multiwavelength observations, we propose a three-stage collapse scenario for this long and bright GRB. We suggest that quasiperiodic fluctuations may be associated with forced precession of a self-gravitating rapidly rotating superdense body (spinar), whose evolution is determined by a powerful magnetic field. The spinar’s mass allows it to collapse into a black hole at the end of evolution.
In a superconductor that lacks inversion symmetry, the spatial part of the Cooper pair wave function has a reduced symmetry, allowing for the mixing of spin-singlet and spin-triplet Cooper pairing ...channels and thus providing a pathway to a non-trivial superconducting state. Materials with a non-centrosymmetric crystal structure and with strong spin-orbit coupling are a platform to realize these possibilities. Here, we report the synthesis and characterisation of high quality crystals of Sn4As3, with non-centrosymmetric unit cell (R3m). We have characterised the normal and superconducting states using a range of methods. Angle-resolved photoemission spectroscopy shows a multiband Fermi surface and the presence of two surface states, confirmed by density-functional theory calculations. Specific heat measurements reveal a superconducting critical temperature of Tc ∼ 1.14 K and an upper critical magnetic field of μ0Hc ≳ 7 mT, which are both confirmed by ultra-low temperature scanning tunneling microscopy and spectroscopy. Scanning tunneling spectroscopy shows a fully formed superconducting gap, consistent with conventional s-wave superconductivity.
Hard X-ray absorption spectroscopy is a valuable in situ probe for non-destructive diagnostics of metal sites. The low-energy interval of a spectrum (XANES) contains information about the metal ...oxidation state, ligand type, symmetry and distances in the first coordination shell but shows almost no dependency on the bridged metal-metal bond length. The higher-energy interval (EXAFS), on the contrary, is more sensitive to the coordination numbers and can decouple the contribution from distances in different coordination shells. Supervised machine-learning methods can combine information from different intervals of a spectrum; however, computational approaches for the near-edge region of the spectrum and higher energies are different. This work aims to keep all benefits of XANES and extend its sensitivity towards the interatomic distances in the first and second coordination shells. Using a binuclear bridged copper complex as a case study and cross-validation analysis as a quantitative tool it is shown that the first 170 eV above the edge are already sufficient to balance the contributions of Cu-O/N scattering and Cu-Cu scattering. As a more general outcome this work highlights the trivial but often overlooked importance of using `longer' energy intervals of XANES for structural refinement and machine-learning predictions. The first 200 eV above the absorption edge still do not require parametrization of Debye-Waller damping and can be calculated within full multiple scattering or finite difference approximations with only moderately increased computational costs.
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•New 8-oxadiazole spiropyrans undergo positive photochromism.•8-oxadiazole spiropyrans form complexes with transition metal ions.•Complexes of merocyanines with Zn2+, Cd2+ possess ...negative photochromism.•Cation induced isomerization into merocyanine complexe can be controlled by light.•Photochromic transformations can be driven by transition metal ions.
New 8-(5-(p-tolyl)-1,3,4-oxadiazol-2-yl) substituted spirobenzopyrans appear as polychromogenic molecular system demonstrating both positive photochromism and ionochromic properties. Introduction of electron withdrawing formyl group into 6-position of the pyran part leads to increasing of spiropyran photocoloration reaction efficiency but decreases thermodynamical stability of merocyanine form complexes. Upon irradiation with visible light colored solutions of complexes with Zn2+, Cd2+ ions exhibiting negative photochromism, undergo reversible discoloration as a result of photodissociation characterized by the quantum yields reaching 46%. On one side this allows realizing controlled by light irradiation cation induced isomerizations into complexes of the merocyanine form. On the other hand, a system, in which direction of photochromic transformations can be driven by transition metal ions, can be designed.
The paper reports complementary studies of the order parameter of the newly discovered iron-based superconductor, KCa
2
Fe
4
As
4
F
2
(
T
c
= 34 K), that consists of alternating blocks of KFe
2
As
2
...(122) phase and CaFeAsF (1111) phase. We performed high-resolution intrinsic multiple Andreev reflection spectroscopy supplemented with self-field critical current measurements. Andreev spectra obtained by means of a break-junction technique reveal two distinct superconducting order parameters Δ
L
and Δ
S
. Their temperature dependencies were measured from 1.5 K to
T
c
. The shapes of Andreev reflections dips, corresponding to the two gaps are symmetrical, which is a signature of
s
-wave order parameter. Temperature dependence of the self-field critical current can also be described by two
s
-wave gaps model.
Molecular genetic studies of the morphological genus Polyporus s. l. recently made it possible to detect the presence of several phylogenetic lineages among its representatives, to clarify the ...boundaries and scope of the taxon. Species with a black cuticle covering the stipe of the basidiomata have been separated in the genus Picipes. Most representatives of this genus are known from China. In Russia, out of 29 species of the genus, there are three widespread species of Picipes – P. badius, P. melanopus, P. tubaeformis, and one rare species – P. rhizophilus. Phylogenetic analysis of the nucleotide sequences of selected nrDNA loci obtained from the herbarium materials collected by us, originally assigned to Picipes melanopus, revealed the presence of two rare, morphologically similar species, P. submelanopus and P. ulleungensis, which turned out to be new to Russia. Picipes submelanopus is characterized by a terrestrial fruiting bodies and differentiated from P. melanopus, that grows on dead wood. All specimens of fruiting bodies of Picipes submelanopus collected by us in Western Siberia were found on the roots of woody plants, as in the typе locality in China. Picipes ulleungensis differs from P. melanopus by larger fruiting bodies, slightly larger pores. In order to differentiate Picipes submelanopus and P. ulleungensis from morphologically similar species, in addition to morphological characters and ecological preferences, it is desirable to use DNA barcoding methods.
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