Contemporary Issues of Commercial Invertebrates’ Harvesting in the Russian Sector of the Barents Sea

The Russian fishery for invertebrate hydrobionts in the Barents Sea includes the list of a dozen species of crustaceans, mollusks, and echinoderms. This type of fishery is characterized by great diversity in relation to the status of exploited stocks, catch size, and economic efficiency of the fishery. The list of up-to-date problems of this industry is long and includes biological, scientific, commercial, socio-economical, and market issues. Among the main problems of the Russian invertebrate fishery in the Barents Sea, overfishing, underutilization of a number of stocks, and significant emissions from fishing waste are considered. The causes of these problems, possible solutions and the priorities of such a solution are analyzed

THREE ESSAYS ON LIQUIDITY IN MODERN MARKETS

Recent technological advancements have challenged financial markets. Academic researchers, regulators and market participants voice concerns that modern markets bear the negative externalities of such advancements. Specifically, they are concerned that today’s markets are becoming more fragile and unfair to less sophisticated traders. This work employs empirical methodology to test whether these concerns are justified. This thesis contains three essays: The first essay studies whether modern markets become less liquid during intraday extreme price movements (EPMs). When a price moves in a certain direction, liquidity providers face two opposing incentives. The first incentive is to stay in the market to accumulate more inventory in anticipation of a price reversal. The second incentive is to withdraw due to capital constraints, inventory and adverse selection risks. Using data from Canadian and U.S. markets, I find that the former incentive is stronger during intraday EPMs. This finding alleviates concerns that prices are subject to periods of extreme volatility due to systematic liquidity withdrawals. Contrary to these concerns, liquidity providers appear sufficiently incentivized to dampen intraday volatility. The second essay examines the activity of a specific type of modern liquidity providers – high frequency traders (HFTs) – around EPMs. I find that, on average, HFTs provide liquidity during EPMs by absorbing imbalances created by non-high frequency traders (nHFTs). Yet HFT liquidity provision is limited to EPMs in single stocks. When several stocks experience simultaneous EPMs, HFT liquidity demand dominates their supply. There is little evidence of HFTs causing EPMs. The third essay studies whether recent technological advancements result in higher costs for less sophisticated traders. In modern markets, trading firms spend generously to gain a speed advantage over their rivals. The marketplace that results from this rivalry is characterized by speed differentials whereby some traders are faster than others. Is such a marketplace optimal? To answer this question, I study a series of exogenous weather-related episodes that temporarily remove the speed advantages of the fastest traders by disrupting their microwave networks. During these episodes, adverse selection declines accompanied by improved liquidity and reduced volatility. Liquidity improvement is larger than the decline in adverse selection consistent with the emergence of latent liquidity and enhanced competition among liquidity suppliers. The results are confirmed in an event-study setting, whereby a new business model adopted by one of the technology providers reduces speed differentials among traders, which results in liquidity improvements

Oblique Polarized Reflectance Spectroscopy for Depth Sensitive Measurements in the Epithelial Tissue

Optical spectroscopy has shown potential as a tool for precancer detection by discriminating alterations in the optical properties within epithelial tissues. Identifying depth-dependent alterations associated with the progression of epithelial cancerous lesions can be especially challenging in the oral cavity due to the variable thickness of the epithelium and the presence of keratinization. Optical spectroscopy of epithelial tissue with improved depth resolution would greatly assist in the isolation of optical properties associated with cancer progression. Here, we report a fiber optic probe for oblique polarized reflectance spectroscopy (OPRS) that is capable of depth sensitive detection by combining the following three approaches: multiple beveled fibers, oblique collection geometry, and polarization gating. We analyze how probe design parameters are related to improvements in collection efficiency of scattered photons from superficial tissue layers and to increased depth discrimination within epithelium. We have demonstrated that obliquely-oriented collection fibers increase both depth selectivity and collection efficiency of scattering signal. Currently, we evaluate this technology in a clinical trial of patients presenting lesions suspicious for dysplasia or carcinoma in the oral cavity. We use depth sensitive spectroscopic data to develop automated algorithms for analysis of morphological and architectural changes in the context of the multilayer oral epithelial tissue. Our initial results show that OPRS has the potential to improve the detection and monitoring of epithelial precancers in the oral cavity.Biomedical Engineerin

Ultrastructural characterization of colloidal metal films for bioanalytical applications by scanning force microscopy

Colloidal metal films (CMFs) are prepared by the attachment of silver, gold, or platinum (or other metal) particles to a glass slide modified by silanization with 3‐mercaptopropyl silane. The covalent attachment of the metal particles occurs through the metal–sulfur bond. In these samples the local electromagnetic field is enhanced near the surface of the CMF due to excitation of plasmon resonances. This phenomenon can be used for a variety of analytical applications. Because the optical properties are strongly dependent on the morphology of the film, its structural characterization becomes of great importance. To further characterize CMFs we have used scanning force microscopy (SFM). Initial studies revealed lateral dimensions of the particles as well as the particle density. Height measurements were made using the three‐dimensional topographic image of the surface yielded by SFM, and were used to evaluate the selective deposition of a silica spacer layer onto the metal particles. Comparative SFM measurements in water and air using different imaging modes were performed to investigate the mechanical stability of CMFs against the forces exerted by the scanning tip

NONLINEAR ANALYSIS OF STATICALLY INDETERMINATE WOODEN STRUCTURES AND OPTIMIZATION OF CROSS SECTION DIMENSIONS OF DOME RIBS

The analysis of the behaviour of natural structures of laminated wood domes and the numerous preliminary calculations have shown the possibility of saving materials by reducing the height of cross sections of meridional ribs. This is especially effective when you include in design of skins, performing a role of building shell, the collaboration with frame elements (annular and longitudinal ribs). Multiple static indeterminacy of such structure allows its non-linear work and the redistribution of forces under nonuniform loads. At the same ime, the skin carries a significant part of the forces appearing in the shell and the ribs are underloaded. The tress-strain states of all elements are investigated. For the frame analysis the calculation is performed by the method of integral module that allows controlling strength resistance of a structure at any moment of its operation. The design recommendations for section dimensions of a shell are developed

Respublika mechei ili torgovaia respublika ?

Les auteurs analysent la représentation qui est faite de la toute puissante république de Novgorod dans les écrits historiques et politiques russes du xviiie – début du xixe siècle. Dans la tradition européenne, la république classique est une république militaire, qui s’appuie sur le modèle de la république romaine militairement puissante. En opposition, la république commerciale est considérée comme un petit État, inférieure militairement aux grandes monarchies. La pensée sociale russe, à commencer par celle développée par A.I. Mankiev, identifie Novgorod à une république mais demeure ambivalente dans l’évaluation de sa puissance militaire. Sous l’influence de l’imagerie romaine et du discours général « de gloire et de grandeur » de la fin du xviiie siècle, un canon s’est mis en place, qui fait de l’ancienne Novgorod « une république militaire » tout en conservant la république commerciale comme outil conceptuel pour l’analyse de l’histoire ultérieure de la ville. La reconnaissance d’un pouvoir militaire à la république de Novgorod sape l’un des arguments clés en faveur de la monarchie, selon lequel seule une monarchie est capable de contrôler et défendre efficacement un large territoire. De ce fait, l’évaluation de Novgorod en tant que république militaire marque une étape importante dans l’apparition dans la société russe du xixe siècle d’une alternative républicaine à un monarchisme apparemment inébranlable.The authors analyze how the powerful Republic of Novgorod was represented in Russian historical and political writing between the eighteenth and early nineteenth centuries. In the European tradition, a republic typically was military and modeled on the Roman Republic and its military strength. In contrast, the trading republic was considered a small state, militarily inferior to great monarchies. Russian social thought, starting with A.I. Mankiev’s, identified Novgorod with a military republic while remaining ambivalent in assessing its military might. The influence of Roman imagery and the general discourse on “glory and grandeur” of the late eighteenth century brought about the emergence of a model of old Novgorod as a military republic and set aside the trading republic as a conceptual toolkit for studying the town’s future historical development. Recognition of military power in the Republic of Novgorod undermined one of the key arguments in favor of monarchy – the claim that monarchy alone is able to effectively control and protect a vast territory. Thus, viewing Novgorod as a military republic was an important step towards the rise, in early‑nineteenth‑century Russian society, of a republican alternative to a seemingly immutable monarchy

Roles of Mitochondrial Dynamics under Stressful and Normal Conditions in Yeast Cells

Eukaryotic cells contain dynamic mitochondrial filaments: they fuse and divide. Here we summarize data on the protein machinery driving mitochondrial dynamics in yeast and also discuss the factors that affect the fusion-fission balance. Fission is a general stress response of cells, and in the case of yeast this response appears to be prosurvival. At the same time, even under normal conditions yeast mitochondria undergo continuous cycles of fusion and fission. This seems to be a futile cycle and also expensive from the energy point of view. Why does it exist? Benefits might be the same as in the case of sexual reproduction. Indeed, mixing and separating of mitochondrial content allows mitochondrial DNA to segregate and recombine randomly, leading to high variation in the numbers of mutations per individual mitochondrion. This opens a possibility for effective purifying selection-elimination of mitochondria highly contaminated by deleterious mutations. The beneficial action presumes a mechanism for removal of defective mitochondria. We argue that selective mitochondrial autophagy or asymmetrical distribution of mitochondria during cell division could be at the core of such mechanism

Plastic pollution tendencies of the Barents Sea and adjacent waters

The article represents the analysis of the plastic pollution of water areas and coasts of the Barents Sea and adjacent waters based on foreign and Russian studies. The authors consider the influence of various factors, including climate change in the Arctic. The threat to various types of marine activities and the marine ecosystem from plastic pollution is evaluated. The emphasis is on the existing and potential damage to industrial fisheries in the Barents Sea and adjacent waters. An analysis of the regulatory and organizational and economic mechanisms for preventing plastic pollution of the Arctic seas and coasts of the Arctic Council member states and practices of their application is carried out. Particular attention is paid to the control and supervision over litter collection onboard and the efficiency of its disposal after delivery to the land. To improve the legal regulation of handling waste of production and consumption, it is justified to adopt the draft federal law “On secondary material resources”; to create a financial platform for the circular economy in analogy with the European Union and to develop technologies to increase the life cycle and reuse of goods made of plastic. To supplement to the activities of the “State Program Social and Economic Development of the Arctic zone of the Russian Federation” and the state programs for social and economic development of the Arctic, it is proposed to include various types of plastic in the list of hazardous pollutants of water areas and coasts of the Russian Arctic and to build facilities for processing of plastic wastes from fishing enterprises in the Arctic. Also, the regional authorities should encourage volunteering for cleaning coasts of the Barents Sea from garbage, incl. plastic

Bound-state beta-decay of a neutron in a strong magnetic field

The beta-decay of a neutron into a bound $(pe^-)$ state and an antineutrino in the presence of a strong uniform magnetic field ($B \gtrsim 10^{13}$ G) is considered. The beta-decay process is treated within the framework of the standard model of weak interactions. A Bethe-Salpeter formalism is employed for description of the bound $(pe^-)$ system in a strong magnetic field. For the field strengths $10^{13}$ G$\lesssim B \lesssim10^{18}$ G the estimate for the ratio of the bound-state decay rate $w_b$ and the usual (continuum-state) decay rate $w_c$ is derived. It is found that in such strong magnetic fields $w_b/w_c \sim 0.1-0.4$. This is in contrast to the field-free case, where $w_b/w_c \simeq 4.2 \times 10^{-6}$ [J. N. Bahcall, Phys. Rev. {\bf 124}, 495 (1961); L. L. Nemenov, Sov. J. Nucl. Phys. {\bf 15}, 582 (1972); X. Song, J. Phys. G: Nucl. Phys. {\bf 13}, 1023 (1987)]. The dependence of the ratio $w_b/w_c$ on the magnetic field strength $B$ exhibits a logarithmic-like behavior. The obtained results can be important for applications in astrophysics and cosmology.Comment: 22 pages (revtex4), 1 figure; v2: more detailed discussion on astrophysical applications in conclusion section, accepted for publication in Phys. Rev.