Research highlights

Y. Suzuki,T. Nakata, M. Watanabe, S. Battulga,D.  Enkhtaivan, S. Demberel, C. Odonbaatar, A. Bayasgalan, T. Badral

Destructive large earthquakes occur not only along major plate boundaries but also within the interior of plates. To establish appropriate safety measures, identifying intraplate active faults and the potential magnitude of associated earthquakes is essential before an earthquake occurs. This study was conducted to document the geomorphic expression of a previously unrecognized 50‐km‐long active fault in Ulaanbaatar, the capital of Mongolia. Mapping of the fault was accomplished using the Advanced Land Observation Satellite elevation dataset provided by Japan Aerospace Exploration Agency (JAXA), a stereo‐scope interpretation of CORONA satellite images, the emplacement of trenches across the fault trace, and field study. The Ulaanbaatar fault (UBF) is marked by fault scarps on the surface and left‐lateral stream deflections. The fault displaces late Pleistocene deposits and is thus considered to be active. Based on the length of the fault, the UBF is believed to be capable of causing earthquakes with magnitudes greater than M7 and subsequent associated damage to buildings and heavy causalities within the metropolitan area. We strongly suggest that building resistance requirements in Ulaanbaatar should be revised to mitigate for the potential of extensive seismic damage. The results of this study can be used to revise the seismic hazard map and stipulate a new disaster prevention strategy to improve public safety in Ulaanbaatar. It is also possible that there may be other active faults in the vicinity of Ulaanbaatar, and these require investigation. See more…

Diyendo Massilani, Laurits Skov, Mateja Hajdinjak, Byambaa Gunchinsuren, Damdinsuren Tseveendorj, Seonbok Yi, Jungeun Lee, Sarah Nagel, Birgit Nickel, Thibaut Devièse,Tom Higham, Matthias Meyer, Janet Kelso, Benjamin M. Peter, Svante Pääbo

We present analyses of the genome of a ~34,000-year-old hominin skull cap discovered in the Salkhit Valley in northeastern Mongolia. We show that this individual was a female member of a modern human population that, following the split between East and West Eurasians, experienced substantial gene flow from West Eurasians. Both she and a 40,000-year-old individual from Tianyuan outside Beijing carried genomic segments of Denisovan ancestry. These segments derive from the same Denisovan admixture event(s) that contributed to present-day mainland Asians but are distinct from the Denisovan DNA segments in present-day Papuans and Aboriginal Australians. See more…

Isolation and characterization of antiprotozoal compound-producing Streptomyces species from Mongolian soils

Pagmadulam B., Tserendulam D., Rentsenkhand Ts., Masayuki Igarashi., Ryuichi Sawa, Coh-ichi Nihei, Yoshifumi Nishikawa

Natural resources are recognized as important sources of potential drugs for treating various infections, and microorganisms are a rich natural source of diverse compounds. Among the world's microorganisms, actinomycetes, which are abundant in soil and marine, are the well-known producers of a wide range of bioactive secondary metabolites and antibiotics. In the present study, four actinomycetes (samples N25, N6, N18, and N12) were isolated from soil samples in Mongolia. Phylogenetic analysis of these isolates revealed that they share the highest similarity with Streptomyces canus (N25), S. cirratus (N6), S. bacillaris (N18) and S. peucetius (N12), based on 16S rRNA gene sequencing. Crude extracts were obtained from them using ethyl acetate, and the crude fractions were separated by thin layer chromatography. The fractions were then evaluated for their cytotoxicities and their anti-Toxoplasma and antimalarial activities in vitro. The S. canus (N25) crude extract was selected for further chemical characterization based on its antiprotozoal activities. Using liquid chromatography-high resolution mass spectrometry, phenazine-1-carboxylic acid (PCA) was detected and identified in the active fractions of the metabolites from strain N25. We next confirmed that commercially available PCA possesses antiprotozoal activity against T. gondii (IC₅₀: 55.5 μg/ml) and Plasmodium falciparum (IC₅₀: 6.4 μg/ml) in vitro. The results of this study reveal that soil actinomycetes are potential sources of antiprotozoal compounds, and that PCA merits further investigation as an anti-protozoal agent. See more…

Allometric equations for estimating aboveground biomass of Nitraria sibirica Pall. in Gobi Desert of Mongolia

Javkhlan Nyamjav, Munkh-Erdene Batsaikhan, Guangliang Li, Jia Li, Amgalan Luvsanjamba, Kun Jin, Wenfa Xiao, Liji Wu, Tuvshintogtokh Indree, Aili Qin

Nitraria sibirica Pall. is a shrub species belonging to the family of Nitrariaceae. It plays pivotal role in arid ecosystems since it is tolerant to high salinity and drought. This species is widely distributed throughout Mongolia and it is mostly found in arid ecosystems of Mongolian Gobi Desert. In this study, we developed allometric equations for estimating aboveground biomass of N. sibirica using various structural descriptors and pinpointed the best models. Variables that precisely predicted above-ground biomass were a combination of basal diameter, crown area, and height. The allometric growth equation constructed is not merely helpful to achieve accurate estimations of the above-ground biomass in shrub vegetation in the Gobi Desert of Mongolia, but also can provide a reference for the above-ground biomass of Nitraria species growing in analogous habitats worldwide. Therefore, our research purposes an important advance for biomass estimation in Gobi ecosystems and complements previous studies of shrub biomass worldwide. This study provides reasonable estimates of biomass of N. sibirica, which will be valuable in evaluations of biological resources, especially for quantifying the main summer diet of Gobi bears, and also can be an alternative tool for assessing carbon cycling in Gobi Desert. See more…

Bilguun Bayarsaikhana, Seoktae Kohb, Enkhbat Tsedenbaljira, Gansukh Tumurtushaa

In light of the cosmological observations, we investigate dark energy models from the Horndeski theory of gravity. In particular, we consider cosmological models with the derivative self-interaction of the scalar field and the derivative coupling between the scalar field and gravity. We choose the self-interaction term to have an exponential function of the scalar field with both positive and negative exponents. For the function that has a positive exponent, our result shows that the derivative self-interaction term plays an important role in the late-time universe. On the other hand, to reproduce the right cosmic history, the derivative coupling between the scalar field and gravity must dominate during the radiation-dominated phase. However, the importance of such a coupling in the present universe found to be negligible due to its drastic decrease over time. Moreover, the propagation speed of gravitational waves estimated for our model is within the observational bounds, and our model satisfies the observational constraints on the dark energy equation of state. See more…

Middle Paleozoic intermediate-mafic rocks of the Tsoroidog Uul’ accretionary complex, Central Mongolia: Petrogenesis and tectonic implications

Lkhagvasuren Dagva-Ochir, Tumen-Ulzii Oyunchimeg, Batkhuyag Enkhdalai, Inna Safonova, Huan Li, Dorjsuren Otgonbaatar, Ladry Soh Tamehe, Davaanyam Sharav

The Tsoroidog Uul’ accretionary complex is hosted by the Tsetserleg terrane in the southwestern KhangayKhentey orogenic system (Central Mongolia), which represents the segment of the Central Asian Orogenic Belt and hassignificantregional implications foritstectonic evolution.This paper reports the results of field investigations and petrography, bulk-rock major and trace element geochemical, as well as Sm–Nd isotopes of Middle Paleozoic intermediate-mafic rocks from the Tsoroidog Uul’ accretionary complex. We investigate a wide range of rock types which can be divided into 4 groups on the basis of their TiO₂ and REE characteristics. Group 1 is characterized by moderate TiO₂, relatively flat chondrite-normalized REE patterns (La/Sm_n=1.0; Gd/Yb_n=1.2). These basalts are divided into two subgroups: (1) Nb/Th_pm=3.6, Nb/La_pm=0.8, Zr/Nb=24.6, and Ce/Yb_pm=0.8 (N-MORB type); (2) Nb/Th_pm=1.3, Nb/La_pm=1.1, Zr/Nb=11.9, and Ce/Yb_pm=1.6 (E-MORB type). Group 2 shows high TiO₂ and LREE (La/Sm_n=3.0), differentiated HREE (Gd/Yb_n=2.5), positive Nb anomalies shown in primitive mantle-normalized multi-element patterns (Nb/Th_pm=1.2; Nb/La_pm=1.1), and low Zr/Nb_av. ratios (~6). Group 3 displays low TiO₂, high LREE (La/Sm_n= 3.6), Zr/Nb_av.=24.4, and low Nb (Nb/La_pm=0.2). Group 4 exhibits moderate TiO₂, flat REE patterns (La/Sm_n=0.8; Gd/Yb_n=1.1), negative Nb anomalies (Nb/Th_pm=0.3; Nb/La_pm=0.6) and Zr/Nb_av.=33. The εNd(t) values are positive for Group 1 and Group 2, but negative for Group 3. Based on their petrological and geochemical features, we suggest that the Group 1 and 2 mafic volcanic rocks were formed in an oceanic environment, and represent mid-oceanic ridge basalt (MORB) and oceanic-island basalt (OIB), respectively. In contrast, Group 3 intermediate dikes probably have supra-subduction origin with calc-alkaline features, whereas Group 4 represents arc tholeiite basalt including remnants of the continental volcanic arc. Overall, the Middle Paleozoic intermediate-mafic rocks of the Tsoroidog Uul’ accretionary complex were probably generated from heterogenous mantle sources. Thus, we propose that spatial and temporal changes of the Paleo-Pacific Oceanic lithosphere, which subducted under the continental margin of the Siberian Craton, resulted in the variable composition of the intermediate-mafic rocks of this complex. The accretionary complex of the Tsetserleg terrane, which extends into Ulaanbaatar terrane, was formed by subduction of the Paleo-Pacific Oceanic lithosphere or Mongol-Okhotsk Ocean. See more…

Evdokia E. Khabunova, Ludmila S. Dampilova, Alimaa Ayuushzhaviyin

Introduction. The article examines the motif of heroic duel (combat) as an important segment of the epic plot, and our comparative analysis of the nuclear basis of the motif and its variation list proves instrumental in delineating a structural-meaningful model motif invariant inherent to the epic of Mongolic peoples and depicting military conflicts. The issue has never been dealt with in this perspective. Goals. The work seeks to determine a variation row of the invariant motif in national epic traditions of Buryats, Kalmyks, Mongols, and Oirats. Materials. The variation row to be extracted from Mongolic epic narratives, namely: Buryat uligers of Abai Geser (Ungin version of P. Petrov) and Abai Geser Khubun (Ekhirit-Bulagat version of M. Emegenov), Baga Dorbet and Eelyan Ovla’s cycles of the Kalmyk Epic of Jangar, Xinjiang Oirat version of the Jangar, Oirat Mongolian tuuli texts titled Daini Kyurel and Khan Kharangui, and a Khalkha tuuli titled Agiyin Ulan Khan. Methods. To identify the typology and variable interpretations of the motif, the study uses elements of the comparative-typological and comparative-historical methods. The ‘heroic duel (combat)’ motif model is viewed as an element that hypothetically can act as the most important lever within the plot development mechanism, e.g., evolving from a motif ― a ‘simplest narrative unit’ ― to a plot, and vice versa. When it comes to identify the motif, its dualistic nature, variety of its properties and features noted by Russian and foreign scientists are taken into account. Results. The comparative insight into the motif of heroic duel (combat) makes it possible to single out the motif as an essential constructive and meaningful element of the plot, examine the degree of productivity and mobility of the motif in genetically related though stadially differing epics, as well as in ones belonging to various taletelling traditions, observe heroic confrontation patterns in epics of Mongolic peoples. Conclusions. The study concludes that motif invariants tend to form a plot basis, while motif variants express certain features (stadial, national, local) of each epic tradition. See more…

First-principles prediction of a two-dimensional vanadium carbide (MXene) as the anode for lithium ion batteries

Shirchinnamjil Nyamdelger, Tumentsereg Ochirkhuyag, Deleg Sangaa, Dorj Odkhuu

Exploring two-dimensional anode materials that can utilize the storage capacity and diffusion mobility of Li ions is at the heart of lithium ion battery (LIB) research. Herein, we report the results of ab initio electronic structure calculations on the storage capacity and diffusion mobility affinities of Li ions adsorbed onto nondefective and defective MXene V2C monolayers. It is found that Li ions strongly chemisorb on the two sides of the V2C surface with a preferential adsorption site at the hollow center of the honeycomb structure. The binding profile and open-circuit voltage calculations reveal that the Li/V2C structure exhibits a specific capacity as high as 472 mA h g−1 at the Li2V2C stoichiometry, a value relatively high compared with those of the typical anode materials including graphite (372 mA h g−1). Furthermore, the diffusion barrier of a Li ion over the V2C surface is identified to be no more than 0.1 eV, which is a few times smaller than that of graphene and graphitic anodes. In addition, during the lithiation and delithiation processes, the change in the lateral lattice is quite small, only about a 2% increase at the full lithiation of Li2V2C, implying a good cycling performance. Importantly, these intriguing findings are very robust against the intrinsic structural and atomic defects including local point vacancies and biaxial compressive and tensile strains. More specifically, the presence of a monovanadium vacancy enhances the binding energy up to 3.1 eV per Li ion, which is about a 30% enhancement compared with the defect-free Li/V2C structure, and reduces the activation barrier by about 2 meV; meanwhile, these binding and diffusion mobility features can be improved even more when the lattice constant of the V2C monolayer is expanded. These results thus suggest that MXene V2C could be a promising anode material with high capacity and high rate capabilities for next generation high-performance LIBs. See more…