At the orogenic gold deposits of the Yana–Kolyma metallogenic belt (northeast Russia) both Au–quartz-sulfide mineralization with native gold and disseminated sulfide mineralization with invisible Au developed. The textural and mineralogical-geochemical features, isotope-geochemical characteristics of gold-bearing sulfides from proximal metasomatites, and possible forms of Au occurrence in pyrite and arsenopyrite have been studied using electron microprobe, atomic absorption, LA-ICP-MS trace element, isotope analysis, and computed microtomography. Four generations of pyrite (Py1, diagenetic; Py2, metamorphic; Py3, metasomatic; Py4, veined) and two generations of arsenopyrite (Apy1, metasomatic; Apy2, veined) have been identified at the Khangalas deposit. In the proximal metasomatites, the most common are Py3 and Apy1. Studying their chemical composition makes it possible to identify the features of the distribution patterns of typochemical trace elements in pyrite and arsenopyrite, and to establish the nature of the relationship between Au and these elements. In Py3 and Apy1, structurally bound (solid solution) Au⁺ prevails, isomorphically entering the crystal lattice or its defects. Isotope characteristics of hydrothermal sulfides (δ³⁴S = −2.0 to −0.6‰) indicate that mantle/magmatic sulfur was involved in the formation of the deposit, though the participation of sulfur from the host rocks of the Verkhoyansk clastic complex cannot be ruled out. The Khangalas deposit has much in common with other gold deposits of the Yana–Kolyma metallogenic belt, and from this point of view, the results obtained will help to better reveal their gold potential and understand their origin.

An integrative analysis of an isolated population of Harting’s vole (Microtus hartingi) from the Eastern Rhodope Mountains (Bulgaria) was carried out by morphological and morphometric methods, computed tomography, Cytb variation data, and experimental hybridization. Substantial changes in the development of the skull and teeth were found. Nevertheless, those voles can live to the senex stage. A phylogenetic reconstruction based on Cytb sequences showed that M. hartingi from the Eastern Rhodopes forms a separate clade, which is a sister clade to the voles from Northeastern Greece (also from the foothills of the Rhodopes). M. hartingi from the Rhodopes is mostly isolated reproductively from M. h. ankaraensis from Anatolia (Turkey), as evidenced by a decrease in the proportion of pairs that started breeding, relatively high mortality of pups, and increased sterility of hybrid males. Possible time of isolation of the Rhodopean population and consequences of the “bottleneck” effect on its current state are discussed. At the same time, we believe that, at present, it is impossible to determine its taxonomic status. It is necessary to recognize M. hartingi from the Bulgarian Rhodopes as an endangered population and to include it in regional Red Lists of Bulgaria.

The extraction of museum DNA from a unique collection of samples of the “Crocidura pergrisea” species complex, which comprises local endemics of Central and West Asia, allowed us to determine their inter- and intragroup relationships. The first step of this study was the re-evaluation of heavily damaged type specimens of C. armenica via a microcomputed-tomography-based cybertaxonomic approach (CTtax), which enabled a precise description of the species’ morphology; three-dimensional models of the cybertypes were made available through the MorphoBank Repository. We developed the “AProMaDesU” pipeline on the basis of five requirements for micro-CT-based cyber-datasets in relation to mammalian collections. Our second step was a combination of several meticulous approaches to morphological investigation against a background of a cytb-based phylogeny, which helped us to make a taxonomic decision about the status of species of the “pergrisea” group, e.g., C. arispa, C. armenica, and C. serezkyensis, when the morphological results were partly incongruent with the molecular phylogeny. Nevertheless, under two assumptions, our findings preserved a separate species-level status of C. serezkyensis and C. arispa. In addition, we restored the species-level status of C. armenica. This taxonomic decision is based on our morphospace analysis, which revealed unique craniomandibular shape transformations within the rocky shrews that helped them with the transition to a new area of morphospace/trophic niches and consequently separated them from the other analyzed Crocidura groups.

The limits of solid solutions and thermal deformations in the L-alanine–L-serine (L-ala–L-ser) amino acid system have been determined. Thirteen amino acid mixtures with various proportions of the components L-ser/L-ala were studied using powder X-ray diffraction techniques. It was found that the regions of solid solutions in the system are rather limited and cover less than 10 mol. % from each component side. The thermal behavior of the components L-ser and L-ala and the composition L-ser/L-ala = 90/10 were studied by temperature-resolved powder X-ray diffraction. The heating of L-ser and L-ala only causes thermal deformations, while two-phase mixtures with the 90/10 L-ser/L-ala ratio form solid solutions at elevated temperatures. Additionally, the parameters of the thermal deformation tensor for L-ser and L-ala were calculated, and the figures of their thermal expansion coefficients were plotted and analyzed. The study conducted is of high applicability, since amino acids are active components of various biological, geological, and technological processes, including those at elevated temperatures, and have numerous applications in life-science industries.