Tagansky Complex of Monuments of the Golden Horde Period on the Bityug River

The paper presents the results of a study of the Tagansky complex of monuments of the Golden Horde period on the Bityug River in the Pavlovsky District of Voronezh Oblast. The complex includes a subsoil burial ground, a settlement associated with it, as well as a settlement near Antipovka village. The study was carried out in 1995, 1998–2002 by an expedition of Voronezh State University. The ceramic complex includes pottery manufactured in the Golden Horde centers and Russian ceramics. The economic activity of the population includes agriculture, cattle breeding and metallurgical production. The morphology of skulls from the Tagansky burial ground finds analogies among the substrate Europeoid populations of Eastern Europe

Casimir-Polder attraction and repulsion between nanoparticles and graphene in out-of-thermal-equilibrium conditions

The nonequilibrium Casimir-Polder force between a nanoparticle and a graphene sheet kept at different temperatures is investigated in the framework of Dirac model using the formalism of the polarization tensor. It is shown that the force magnitude increases with increasing temperature of a graphene sheet. At larger separations an impact of nonequilibrium conditions on the force becomes smaller. According to our results, the attractive Casimir-Polder force vanishes at some definite nanoparticle-graphene separation and becomes repulsive at larger separations if the temperature of a graphene sheet is smaller than that of the environment. This effect may find applications both in fundamental investigations of graphene and for the control of forces in microdevices of bioelectronics.Comment: 8 pages, 3 figures; Eq.(25) and Figs. 1 and 3 are correcte

Activated Ion Electron Capture Dissociation (AI ECD) of proteins: synchronization of infrared and electron irradiation with ion magnetron motion.

Here, we show that to perform activated ion electron capture dissociation (AI-ECD) in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer equipped with a CO(2) laser, it is necessary to synchronize both infrared irradiation and electron capture dissociation with ion magnetron motion. This requirement is essential for instruments in which the infrared laser is angled off-axis, such as the Thermo Finnigan LTQ FT. Generally, the electron irradiation time required for proteins is much shorter (ms) than that required for peptides (tens of ms), and the modulation of ECD, AI ECD, and infrared multiphoton dissociation (IRMPD) with ion magnetron motion is more pronounced. We have optimized AI ECD for ubiquitin, cytochrome c, and myoglobin; however the results can be extended to other proteins. We demonstrate that pre-ECD and post-ECD activation are physically different and display different kinetics. We also demonstrate how, by use of appropriate AI ECD time sequences and normalization, the kinetics of protein gas-phase refolding can be deconvoluted from the diffusion of the ion cloud and measured on the time scale longer than the period of ion magnetron motion

ANALYSIS OF THE EDGE EFFECT OF SHEAR STRESSES IN THE SHIFT OF A TWO-LAYER BEAM

The paper presents a system of resolving equations describing the stress-strain state of multilayer beams and allowing solving a wide range of problems, such as shear, bending, and normal separation for any number of layers. For each of the layers, hypotheses similar to the Kirchhoff - Love hypotheses are introduced. In the proposed model, the layers interact with a contact layer. The contact layer is an anisotropic medium, which can be considered as a “brush” of elastic short rods. For simplicity, it is assumed that the rods are oriented normally to the contact surface. The use of a contact layer allows such problems as infinite tangential stresses at the interface between the layers near the end of the beam and also to solve the problem of determining the concentration of the shearing stresses occurring at the boundaries between the layers and in the corner points, their variation, for example, in the creep process. The main feature of the proposed model is strict satisfaction of the boundary conditions. In view of the complexity of the resolving system of equations, we consider, as an example, the problem of shearing the layers of a double-layer beam. An analytical solution is obtained that allows qualitative analysis of the influence of mechanical and geometric characteristics on the stress-strain state of the design model, calculate the true adhesive strength, and determine the physical characteristics of the contact layer on the basis of experimental data. A numerical example is given for calculating a beam in two variants of model loading, on the basis of which a relationship was established between the true and average adhesive strength, depending on various parameters

Nanomesh aluminum films for LC alignment : theoretical and experimental modeling

A porous system for LC alignment is reviewed. Fabrication of nanomesh aluminum films and their porous structure are described. Methods of the nanomesh parameters for optimal LC alignment are discussed. A model of the LC alignment in a porous system is proposed. The LC orientation type is determined by the free anchoring energy and the micropore diameter. The difference between planar and homeotropic anchoring energies appears to be lower than the interaction energy by two orders of magnitude

Analysis of 3800-year-old Yersinia pestis genomes suggests Bronze Age origin for bubonic plague

该论文通过对青铜器时代的两个鼠疫杆菌分离株进行测序，深入剖析了鼠疫杆菌的历史。德国、俄罗斯、中国和瑞士等多国研究员共同参与了研究。这篇论文的第一作者是德国马克斯-普朗克研究所的考古遗传学专家Maria Spyrou。她和同事从俄罗斯墓穴中埋葬的九名古代人的牙齿样本入手，发现有两人感染鼠疫杆菌。之后，他们从这些个体中分离出距今约3800年的病原菌。在这项新研究中，研究人员利用液相捕获和Illumina鸟枪法测序技术，对青铜器时代的一名男子（RT5）的鼠疫杆菌和人类宿主序列进行测序，其中鼠疫杆菌基因组的平均覆盖度达到32倍。同时，他们还对另一名感染个体（RT6）的分离株进行测序，平均覆盖度为1.9倍。系统发育分析表明，RT5和RT6分离株是共同谱系的一部分，这个谱系的祖先是史上三次瘟疫大流行的罪魁祸首。除了众所周知的中世纪欧洲瘟疫大流行，鼠疫杆菌还曾造成公元6世纪的查士丁尼瘟疫和19世纪的中国大规模鼠疫。 马克斯-普朗克人类历史科学研究所的古病理学专家Kirsten Bos表示，这些结果表明“具有传播潜力的瘟疫存在的时间比我们想象得更久。”Bos是这篇论文的通讯作者之一。【Abstract】The origin of Yersinia pestis and the early stages of its evolution are fundamental subjects of investigation given its high virulence and mortality that resulted from past pandemics. Although the earliest evidence of Y. pestis infections in humans has been identified in Late Neolithic/Bronze Age Eurasia (LNBA 5000–3500y BP), these strains lack key genetic components required for flea adaptation, thus making their mode of transmission and disease presentation in humans unclear. Here, we reconstruct ancient Y. pestis genomes from individuals associated with the Late Bronze Age period (~3800 BP) in the Samara region of modern-day Russia. We show clear distinctions between our new strains and the LNBA lineage, and suggest that the full ability for flea-mediated transmission causing bubonic plague evolved more than 1000 years earlier than previously suggested. Finally, we propose that several Y. pestis lineages were established during the Bronze Age, some of which persist to the present day.We thank Cosimo Posth, Marcel Keller, Michal Feldman and Wolfgang Haak for useful insights to the manuscript, as well as Alexander Immel and Stephen Clayton for computational support. In addition, we are thankful to Guido Brandt, Antje Wissgott and Cäcilia Freund for laboratory support. M.A.S., A.H., K.I.B. and J.K. were supported by the ERC starting grant APGREID, and by the Max Planck Society. C.C.W. was supported by the Max Planck Society and the Nanqiang Outstanding Young Talents Program of Xiamen University. D.K. was supported by a Marie Heim-Vögtlin grant from the Swiss National Science Foundation

On the utility of predictive chromatography to complement mass spectrometry based intact protein identification

The amino acid sequence determines the individual protein three-dimensional structure and its functioning in an organism. Therefore, "reading" a protein sequence and determining its changes due to mutations or post-translational modifications is one of the objectives of proteomic experiments. The commonly utilized approach is gradient high-performance liquid chromatography (HPLC) in combination with tandem mass spectrometry. While serving as a way to simplify the protein mixture, the liquid chromatography may be an additional analytical tool providing complementary information about the protein structure. Previous attempts to develop "predictive" HPLC for large biomacromolecules were limited by empirically derived equations based purely on the adsorption mechanisms of the retention and applicable to relatively small polypeptide molecules. A mechanism of the large biomacromolecule retention in reversed-phase gradient HPLC was described recently in thermodynamics terms by the analytical model of liquid chromatography at critical conditions (BioLCCC). In this work, we applied the BioLCCC model to predict retention of the intact proteins as well as their large proteolytic peptides separated under different HPLC conditions. The specific aim of these proof-of-principle studies was to demonstrate the feasibility of using "predictive" HPLC as a complementary tool to support the analysis of identified intact proteins in top-down, middle-down, and/or targeted selected reaction monitoring (SRM)-based proteomic experiments

Analysis of 3800-year-old Yersinia pestis genomes suggests Bronze Age origin for bubonic plague

© 2018 The Author(s). The origin of Yersinia pestis and the early stages of its evolution are fundamental subjects of investigation given its high virulence and mortality that resulted from past pandemics. Although the earliest evidence of Y. pestis infections in humans has been identified in Late Neolithic/Bronze Age Eurasia (LNBA 5000-3500y BP), these strains lack key genetic components required for flea adaptation, thus making their mode of transmission and disease presentation in humans unclear. Here, we reconstruct ancient Y. pestis genomes from individuals associated with the Late Bronze Age period (~3800 BP) in the Samara region of modern-day Russia. We show clear distinctions between our new strains and the LNBA lineage, and suggest that the full ability for flea-mediated transmission causing bubonic plague evolved more than 1000 years earlier than previously suggested. Finally, we propose that several Y. pestis lineages were established during the Bronze Age, some of which persist to the present day