The dynamic model of enterprise revenue management

The article presents the dynamic model of enterprise revenue management. This model is based on the quadratic criterion and linear control law. The model is founded on multiple regression that links revenues with the financial performance of the enterprise. As a result, optimal management is obtained so as to provide the given enterprise revenue, namely, the values of financial indicators that ensure the planned profit of the organization are acquired

Актуальные проблемы гидрологических расчетов в арктической зоне Российской Федерации и сопредельных территориях распространения многолетней мерзлоты

The article reveals the main problems facing hydrologists in engineering design in the Arctic zone of Russia and adjacent territories of permafrost. Climate warming and degradation of permafrost cause a significant transformation of the hydrological cycle. The retrospective observations of runoff cannot be considered therefore in modern conditions. The density of the hydrological network in the permafrost zone of Russia has decreased by more than 1.5 times, and on small rivers – more than three times in recent decades. Thus, the use of standard calculation methods (SP 33-101-2003) to assess the runoff characteristics in the Arctic regions is practically impossible. It is shown that in the developed Arctic countries where the size of the territories and their inaccessibility could be compared with withRussia, the low density of the standard observation network is compensated by the organization of small scientific research stations for studying hydrological processes in various physical and geographical conditions and the development of mathematical modeling methods. It is shown that historicallyRussiawas the leader of hydrological research in cold regions. It is stated that there is an urgent need to create a state program aimed at restoring the previously operating in the cryolithоzone and organizing new research hydrological watersheds, improving the standard hydrological network, and developing complex modeling systems and methods for their parameterization.В статье раскрыты основные проблемы, стоящие перед гидрологами при инженерном проектировании в Арктической зоне России и прилегающих территориях распространения многолетней мерзлоты. Основной из них является практическая невозможность использования стандартных методов расчета (СП 33-101-2003) для оценки характеристик стока в регионах с крайне ограниченными данными наблюдений гидрометрической сети в современных условиях изменений климата. Констатируется срочная необходимость создания государственной программы, направленной на восстановление ранее действовавших в криолитозоне и организацию новых научно-исследовательских гидрологических стационаров, совершенствование стандартной гидрологической сети, а также развитие комплексных моделирующих систем и методов их параметризации

Геофизические признаки источников гигантской наледи на р. Анмангында (Магаданская область)

Giant aufeis fields are the indicators of water exchange processes in the permafrost zone. The study of aufeis dynamics is relevant to assessing the state of the cryosphere in a changing climate. The Anmangynda aufeis which forms upstream of the Kolyma River basin, was as large as 6.8 km2 in the last century and is considered representative of the mountainous territories in the northeast Russia. In recent decades, there have been significant changes in the aufeis formation regime that require updating the understanding of the cryosphere processes. The historical observational data obtained in 1962-1990 for the Anmangynda aufeis allows using it as the present-day object of research.The main goal of geophysical research in 2021-2022 was to study the structure of the Anmangynda aufeis and aufeis glade to determine its genesis and development processes. The main tasks were to identify the boundary between frozen and unfrozen rocks, to reveal groundwater discharge channels, and to assess the aufeis thickness distribution. There were carried out georadar survey using an antenna unit with central frequency of 250 MHz and ground-based capacitively coupled electrical resistivity tomography. It was found that by April 5, 2021, the maximum ice thickness was 4.35 m with an average value of 1.35 m, and the volume of aufeis was 3.56 million m3. By means of georadar, there were performed identification and drilling verification of the groundwater discharge channels from alluvium to aufeis surface, located in the stream beds. There is geophysical evidence of deep bedrock groundwater sources. Based on the electrical resistivity tomography data, there were identified large and locally freezing river taliks, from which the water is squeezed onto the ice surface. It is recommended to conduct further interdisciplinary research to clarify the geophysical results obtained.Гигантские наледи являются индикаторами процессов водообмена в зоне распространения мерзлоты. Исследование динамики наледей является актуальной задачей оценки состояния криосферы в изменяющемся климате. Анмангындинская наледь, формирующаяся в верховьях бассейна р. Колымы, в прошлом веке достигала размеров 6.8 км2 и считается репрезентативной для горных территорий северо-востока России. В последние десятилетия произошли значительные изменения режима наледеобразования, требующие актуализации представлений о процессах криолитозоны. Наличие исторических данных наблюдений на Анмангындинской наледи позволяет использовать ее как объект исследований в настоящее время.Целью геофизических исследований 2021-2022 гг. являлось изучение строения Анмангындинской наледи и наледной поляны для уточнения ее генезиса и процессов формирования. Основными задачами были выявление границ мерзлых и талых пород, каналов разгрузки подземных вод и оценка распределения толщины наледного льда. Проведены георадиолокационные зондирования с антенным блоком центральной частоты 250 МГц и электротомография с заземлениями через емкостную связь. Установлено, что к 5 апреля 2021 г. максимальная толщина льда составила 4.35 м при среднем значении 1.35 м, объем наледи - 3.56 млн м3. С помощью георадара выявлены и заверены бурением каналы разгрузки подземных вод из аллювия под лед, расположенные в руслах проток. Выявлены геофизические признаки глубинных источников подземных вод в коренных породах. По данным электротомографии установлено наличие крупных и локальных промерзающих подрусловых таликов, из которых выжимается вода на поверхность льда

Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles

Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed

Unique PGE–Cu–Ni Noril’sk Deposits, Siberian Trap Province: Magmatic and Tectonic Factors in Their Origin

The unique and very large PGE⁻Cu⁻Ni Noril’sk deposits are located within the Siberian trap province, posing a number of questions about the relationship between the ore-forming process and the magmatism that produced the traps. A successful answer to these questions could greatly increase the possibility of discovering new deposits in flood basalt provinces elsewhere. In this contribution, we present new data on volcanic stratigraphy and geochemistry of the magmatic rocks in the key regions of the Siberian trap province (Noril’sk, Taimyr, Maymecha-Kotuy, Kulyumber, Lower Tunguska and Angara) and analyze the structure of the north part of the province. The magmatic rocks of the Arctic zone are characterized by variable MgO (3.6⁻37.2 wt %) and TiO2 (0.8⁻3.9 wt %) contents, Gd/Yb (1.4⁻6.3) and La/Sm (2.0⁻10.4) ratios, and a large range of isotopic compositions. The intrusions in the center of the Tunguska syneclise and Angara syncline have much less variable compositions and correspond to a “typical trap„ with MgO of 5.6⁻7.2 wt %, TiO2 of 1.0⁻1.6 wt %, Gd/Yb ratio of 1.4⁻1.6 and La/Sm ratio of 2.0⁻3.5. This compositional diversity of magmas in the Arctic zone is consistent with their emplacement within the paleo-rift zones. Ore-bearing intrusions (the Noril’sk 1, Talnakh, Kharaelakh) are deep-situated in the Igarka-Noril’sk rift zone, which has three branches, namely the Bolsheavamsky, Dyupkunsky, and Lower Tunguska, that are prospected for discovering new deposits. One possible explanation for the specific position of the PGE⁻Cu⁻Ni deposits is accumulation of sulfides in these long-lived zones from the Neoproterozoic to the Mesozoic era during magmatic and metamorphic processes. Thus, trap magmatism, itself, does not produce large deposits, but mobilizes earlier formed sulfide segregations in addition carrying metals in the original magmas. These deposits are the results of several successive magmatic events, in which emplacement of the traps was the final event

6-Bromohypaphorine from Marine Nudibranch Mollusk Hermissenda crassicornis is an Agonist of Human α7 Nicotinic Acetylcholine Receptor

6-Bromohypaphorine (6-BHP) has been isolated from the marine sponges Pachymatisma johnstoni, Aplysina sp., and the tunicate Aplidium conicum, but data on its biological activity were not available. For the nudibranch mollusk Hermissenda crassicornis no endogenous compounds were known, and here we describe the isolation of 6-BHP from this mollusk and its effects on different nicotinic acetylcholine receptors (nAChR). Two-electrode voltage-clamp experiments on the chimeric α7 nAChR (built of chicken α7 ligand-binding and glycine receptor transmembrane domains) or on rat α4β2 nAChR expressed in Xenopus oocytes revealed no action of 6-BHP. However, in radioligand analysis, 6-BHP competed with radioiodinated α-bungarotoxin for binding to human α7 nAChR expressed in GH4C1 cells (IC50 23 ± 1 μM), but showed no competition on muscle-type nAChR from Torpedo californica. In Ca2+-imaging experiments on the human α7 nAChR expressed in the Neuro2a cells, 6-BHP in the presence of PNU120596 behaved as an agonist (EC50 ~80 μM). To the best of our knowledge, 6-BHP is the first low-molecular weight compound from marine source which is an agonist of the nAChR subtype. This may have physiological importance because H. crassicornis, with its simple and tractable nervous system, is a convenient model system for studying the learning and memory processes