Anhedonia in the shadow of chronic social defeat stress, or When the experimental context matters

One of the core symptoms of major depression in human is anhedonia. For that reason, one of the main requirements towards experimental depression models is that they be able to demonstrate anhedonia in animals, that have been exposed to stressful events, and other behavioral changes attributable to a depression-like state. However, the results presented in the literature are contradictory: sweet solution intake, which is considered as a parameter of hedonic/anhedonic behavior in animals, responds quite differently to stressful situations in that it is either unaffected or increased or decreased. Different experimental designs used for the study of anhedonia in male mice exposed to chronic social defeat stress were tried to understand the reasons for so contradictory responses. Anhedonia appears as an abrupt reduction in sweet solution consumption in stressed animals and by failure to attain recovery after deprivation. However, it was also demonstrated that sucrose solution intake and preference strongly depend on the experimental context; that the possible critical factor may be prior acquaintance with the hedonic stimulus – or the lack whereof. Analysis of literature data and ours allowed us to conclude that the lack of a significant decrease in sweet solution intake in stressed animals is no evidence of lack of depression. This decrease is evidence of anhedonia only provided other symptoms of depression are present. Hedonic consumable intake can be decreased over various motivations, conditions or diseases, in particular, a high level of anxiety or pathological aggression

New, north-easternmost locality for Bembidion monticola Sturm, 1825 (Coleoptera: Carabidae) in Europe: relict of ancient distribution or a result of range expansion?

A new record of a subpopulation of Bembidion monticola Sturm, 1825 from Arkhangelsk region (Northern Europe, Russia) is discussed. The locality of this record is remote, about 700 km to the east from the northernmost previously known locality of this species. Ecology and distribution of B. monticola in northern Europe are reviewed, as well as possible ways of its spread further to northeast are hypothesised.© Entomologica Fennica. This is an open access article and the attached file is the published pdf

Метод автоматического построения алгоритмов распознавания участков фазовых траекторий

The problem of automated construction of recognizers of anomalies in the behavior of complicated dynamical systems is solved by means of analyzing trajectories obtained from sensors surrounding the system. A specific feature of the problem consists in the fact that, depending on the individual properties of the system and conditions of its operation, trajectories that contain anomalies may significantly differ from each other in amplitude and length. Besides, the training set could be incompletely defined. The algorithm described here is based on the idea of applying an algebraic approach to the labeling of trajectories. It allows to construct recognizers of abnormal behavior of complicated dynamical systems. The training of the algorithm could be done on an incompletely defined training set.Рассматривается задача автоматического построения алгоритмов распознавания нештатного поведения динамических систем. Информация о поведении системы доступна в виде фазовой траектории в пространстве показаний датчиков. Особенностью рассматриваемой задачи распознавания является тот факт, что траектории могут быть существенно искажены по амплитуде и растянуты или сжаты по времени в различных условиях работы системы. В работе предложен метод автоматического построения алгоритмов распознавания нештатного поведения динамических систем по заданной обучающей выборке. Метод позволяет строить алгоритмы распознавания, которые имеют более высокую устойчивость к искажениям фазовых траекторий по сравнению с другими известными методами построения алгоритмов распознавания

Improved Reproducibility of PbS Colloidal Quantum Dots Solar Cells Using Atomic Layer–Deposited TiO2

Thanks to their broadly tunable bandgap and strong absorption, colloidal lead chalcogenide quantum dots (QDs) are highly appealing as solution‐processable active layers for third‐generation solar cells. However, the modest reproducibility of this kind of solar cell is a pertinent issue, which inhibits the exploitation of this material class in optoelectronics. This issue is not necessarily imputable to the active layer but may originate from different constituents of the device structure. Herein, the deposition of TiO2 electron transport layer is focused on. Atomic layer deposition (ALD) greatly improves the reproducibility of PbS QD solar cells compared with the previously optimized sol–gel (SG) approach. Power conversion efficiency (PCE) of the solar cells using atomic layer–deposited TiO2 lies in the range between 5.5% and 7.2%, whereas solar cells with SG TiO2 have PCE ranging from 0.5% to 6.9% with a large portion of short‐circuited devices. Investigations of TiO2 layers by atomic force microscopy and scanning electron microscopy reveal that these films have very different surface morphologies. Whereas the TiO2 films prepared by SG synthesis and deposited by spin coating are very smooth, TiO2 films made by ALD repeat the surface texture of the fluorine‐doped tin oxide (FTO) substrate underneath

High-resolution remote thermography using luminescent low-dimensional tin-halide perovskites

While metal-halide perovskites have recently revolutionized research in optoelectronics through a unique combination of performance and synthetic simplicity, their low-dimensional counterparts can further expand the field with hitherto unknown and practically useful optical functionalities. In this context, we present the strong temperature dependence of the photoluminescence (PL) lifetime of low-dimensional, perovskite-like tin-halides, and apply this property to thermal imaging with a high precision of 0.05 {\deg}C. The PL lifetimes are governed by the heat-assisted de-trapping of self-trapped excitons, and their values can be varied over several orders of magnitude by adjusting the temperature (up to 20 ns {\deg}C-1). Typically, this sensitive range spans up to one hundred centigrade, and it is both compound-specific and shown to be compositionally and structurally tunable from -100 to 110 {\deg} C going from [C(NH2)3]2SnBr4 to Cs4SnBr6 and (C4N2H14I)4SnI6. Finally, through the innovative implementation of cost-effective hardware for fluorescence lifetime imaging (FLI), based on time-of-flight (ToF) technology, these novel thermoluminophores have been used to record thermographic videos with high spatial and thermal resolution.Comment: 25 pages, 4 figure

Geomechanical Modeling for Creating New Technologies of Deep Hydrocarbon Fields Development

Abstract— The paper presents the results of the experimental investigation of the rock physical properties in relation to issues of creating scientific fundamentals for new hydrocarbon production technologies. Nowadays easily accessible deposits of oil and gas which lies at depths of 2-3 km are gradually being depleted. The production of hydrocarbons from unconventional sources becomes all the more urgent. These include shale gas and oil, Arctic hydrocarbon resources, gas hydrates, coal bed methane, oil and gas from deep horizons. The development of such deposits requires the creation of new technologies. The knowledge of mechanical and filtration properties of rocks lying at great depths is needed for creation of the new oil production technologies. The investigation of the dependence of well stability and permeability of rocks on the stress-strain state which is determined by the pressure in the well and its bottom hole design in conditions of high rock pressure is required also. For the first time the tests of reservoir rocks from the depths of more than 6 km were carried out on the true triaxial load system. The real conditions that occur in the vicinity of the borehole for various bottom designs at lowering pressure were experimentally simulated on the unique experimental facility, Triaxial Independent Load Test System built in the Institute for Problems in Mechanics of the Russian Academy of Science. It is found that the possibility to improve the production rate of a well by increasing pressure drawdown in a well exists despite the low permeability and high strength of such rocks.   Index Terms— deep reservoirs, rock, well, the test facility, deformations, stresses, strength, elastic moduli. &nbsp

Coherent spin dynamics of electrons and holes in CsPbBr3_3 perovskite crystals

The lead halide perovskites demonstrate huge potential for optoelectronic applications, high energy radiation detectors, light emitting devices and solar energy harvesting. Those materials exhibit strong spin-orbit coupling enabling efficient optical orientation of carrier spins in perovskite-based devices with performance controlled by a magnetic field. Perovskites are promising for spintronics due to substantial bulk and structure inversion asymmetry, however, their spin properties are not studied in detail. Here we show that elaborated time-resolved spectroscopy involving strong magnetic fields can be successfully used for perovskites. We perform a comprehensive study of high-quality CsPbBr$_3$ crystals by measuring the exciton and charge carrier $g$-factors, spin relaxation times and hyperfine interaction of carrier and nuclear spins by means of coherent spin dynamics. Owing to their "inverted" band structure, perovskites represent appealing model systems for semiconductor spintronics exploiting the valence band hole spins, while in conventional semiconductors the conduction band electrons are considered for spin functionality.Comment: 8 pages, 3 figures + supplementary informatio

Cycles of linear and semilinear mappings

We give a canonical form of matrices of a cycle of linear or semilinear mapping V_1 --- V_2 --- ... --- V_t --- V_1 in which all V_i are complex vector spaces, each line is an arrow ---> or <---, and each arrow denotes a linear or semilinear mapping.Comment: 18 page

Finite-element study of the customized implant for revision hip replacement

This work examines a biomechanical system consisting of the hip endoprosthesis and bones of the pelvic region of a person under a load corresponding to the equilibrium of a person in double-supported state. An assessment of the strength of a customised endoprosthesis has been carried out based on the analysis of the stress-strain state of the finite element model of the “skeleton – hip prosthesis” system when tightening the screws and when the system is subjected the person's weight; dangerous areas of the pelvic bone with high level of stresses have been identified. As recommendations, optimization of the location and number of screws used in order to create a more uniform stress distribution is proposed