62 research outputs found

    Security checking experiments with mobile services

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    In this paper, we continue to investigate th

    Efficient early global relaxation of asteroid Vesta

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    The asteroid Vesta is a differentiated planetesimal from the accretion phase of Solar System formation. Although its present-day shape is dominated by a non-hydrostatic fossil equatorial bulge and two large, mostly unrelaxed impact basins, Vesta may have been able to approach hydrostatic equilibrium during a brief early period of intense interior heating. We use a finite element viscoplastic flow model coupled to a 1D conductive cooling model to calculate the expected rate of relaxation throughout Vesta’s early history. We find that, given sufficient non-hydrostaticity, the early elastic lithosphere of Vesta experienced extensive brittle failure due to self-gravity, thereby allowing relaxation to a more hydrostatic figure. Soon after its accretion, Vesta reached a closely hydrostatic figure with 40–200 My after formation, depending on the assumed depth of megaregolith. The Veneneia and Rheasilvia giant impacts, which generated most non-hydrostatic topography, must have therefore occurred >40–200 My after formation. Based on crater retention ages, topography, and relation to known impact generated features, we identify a large region in the northern hemisphere that likely represents relic hydrostatic terrain from early Vesta. The long-wavelength figure of this terrain suggests that, before the two late giant impacts, Vesta had a rotation period of 5.02 h (6.3% faster than present) while its spin axis was offset by 3.0 ° from that of the present. The evolution of Vesta’s figure shows that the hydrostaticity of small bodies depends strongly on its age and specific impact history and that a single body may embody both hydrostatic and non-hydrostatic terrains and epochs.National Science Foundation (U.S.). Graduate Research Fellowship Progra

    Criminal Prosecution of Persons, Who Committed Criminal, Acts Using the Сryptocurrency in the Russian Federation

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    The law enforcement agencies' main focus aimed at combatting crimes, which were committed with the use of cryptocurrency include struggling and prevention of illegal entrepreneurship, illegal banking activity, tax crime, illegal capital outflows, drug business, terrorism financing, legalization (laundering) of income. These crimes are significantly urgent not only in the Russian Federation, but in the whole world, as they provide further criminal economy's and corresponding institutions' development (ie corruption, illegal immigration, etc.). Thus, the topicality and practical importance of elaborating the methods aimed at crime investigation are doubtless

    The incidence of the anomaly P syndrome in water frogs (Anura, Ranidae, Pelophylax) from the Middle Volga River (Russia)

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    The anomaly P is a widespread morphological anomaly, which occurs in some groups of amphibians, caused by the trematode parasite Strigea robusta (Digenea: Strigeidae). This anomaly has been previously recorded in water frogs of the genus Pelophylax and toads of the genera Bufo and Bufotes. The anomaly P includes symmetrical polydactyly cases as a mild attenuated form of the complex syndrome, which in severe cases includes strong deformations of hindlimbs and forelimbs. Strigea robusta has a complex 3-host life cycle using planorbid mollusks as the first intermediate hosts, amphibian larvae as the second intermediate hosts, and anatid birds as the definitive hosts. Herein, we described new records of the anomaly P syndrome in water frogs of the genus Pelophylax from the northeastern parts of their ranges. Symmetrical polydactyly (as a mild form of the anomaly P syndrome) was found in 30 individuals of three species of water frogs from seven localities: in 25 individuals of P. lessonae from four waterbodies, in four individuals of P. ridibundus from three waterbodies, and one individual of P. esculentus. In Gusevo pond, three individuals of P. lessonae with severe cases of the syndrome were found. This is the first record of the anomaly P in reliably identified hybridogenetic edible frogs (P. esculentus) that have been identified in nature. Additionally, we provided new data about the occurrence of the anomaly P and the prevalence of the trematode S. robusta in mollusks taken from two water bodies where anomalous water frogs were found

    The missing large impact craters on Ceres

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    Asteroids provide fundamental clues to the formation and evolution of planetesimals. Collisional models based on the depletion of the primordial main belt of asteroids predict 10–15 craters >400 km should have formed on Ceres, the largest object between Mars and Jupiter, over the last 4.55 Gyr. Likewise, an extrapolation from the asteroid Vesta would require at least 6–7 such basins. However, Ceres’ surface appears devoid of impact craters >∼280 km. Here, we show a significant depletion of cerean craters down to 100–150 km in diameter. The overall scarcity of recognizable large craters is incompatible with collisional models, even in the case of a late implantation of Ceres in the main belt, a possibility raised by the presence of ammoniated phyllosilicates. Our results indicate that a significant population of large craters has been obliterated, implying that long-wavelength topography viscously relaxed or that Ceres experienced protracted widespread resurfacing

    The first record of natural transfer of mitochondrial DNA from Pelophylax cf. bedriagae into P. lessonae (Amphibia, Anura)

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    The unidirectional natural transfer of mitochondrial (mt) DNA from Pelophylax lessonae into P. ridibundus is a common phenomenon in central Europe. Cases of mtDNA exchange between P. lessonae and other non-clonal species of the genus Pelophylax have been unknown so far. In this paper, we describe the first case of mtDNA transfer from P. cf. bedriagae into P. lessonae, which was found in National Park «Smolny», Republic of Mordovia, Russia

    the geomorphology of ceres

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    ### INTRODUCTION Observations of Ceres, the largest object in the asteroid belt, have suggested that the dwarf planet is a geologically differentiated body with a silicate core and an ice-rich mantle. Data acquired by the Dawn spacecraft were used to perform a three-dimensional characterization of the surface to determine if the geomorphology of Ceres is consistent with the models of an icy interior. ### RATIONALE Instruments on Dawn have collected data at a variety of resolutions, including both clear-filter and color images. Digital terrain models have been derived from stereo images. A preliminary 1:10 M scale geologic map of Ceres was constructed using images obtained during the Approach and Survey orbital phases of the mission. We used the map, along with higher-resolution imagery, to assess the geology of Ceres at the global scale, to identify geomorphic and structural features, and to determine the geologic processes that have affected Ceres globally. ### RESULTS Impact craters are the most prevalent geomorphic feature on Ceres, and several of the craters have fractured floors. Geomorphic analysis of the fracture patterns shows that they are similar to lunar Floor-Fractured Craters (FFCs), and an analysis of the depth-to-diameter ratios shows that they are anomalously shallow compared with average Ceres craters. Both of these factors are consistent with FFC floors being uplifted due to an intrusion of cryomagma. Kilometer-scale linear structures cross much of Ceres. Some of these structures are oriented radially to large craters and most likely formed due to impact processes. However, a set of linear structures present only on a topographically high region do not have any obvious relationship to impact craters. Geomorphic analysis suggests that they represent subsurface faults and might have formed due to crustal uplift by cryomagmatic intrusion. Domes identified across the Ceres surface present a wide range of sizes ( 100 km), basal shapes, and profiles. Whether a single formation mechanism is responsible for their formation is still an open question. Cryovolcanic extrusion is one plausible process for the larger domes, although most small mounds (<10-km diameter) are more likely to be impact debris. Differences in lobate flow morphology suggest that multiple emplacement processes have operated on Ceres, where three types of flows have been identified. Type 1 flows are morphologically similar to ice-cored flows on Earth and Mars. Type 2 flows are comparable to long-runout landslides. Type 3 flows morphologically resemble the fluidized ejecta blankets of rampart craters, which are hypothesized to form by impact into ice-rich ground. ### CONCLUSION The global trend of lobate flows suggests that differences in their geomorphology could be explained by variations in ice content and temperature at the near surface. Geomorphic and topographic analyses of the FFCs suggest that cryomagmatism is active on Ceres, whereas the large domes are possibly formed by extrusions of cryolava. Although spectroscopic analysis to date has identified water ice in only one location on Ceres, the identification of these potentially ice-related features suggests that there may be more ice within localized regions of Ceres' crust. ![Figure][1] Dawn high-altitude mapping orbit imagery (140 meters per pixel) of example morphologic features. ( A ) Occator crater; arrows point to floor fractures. ( B ) Linear structures, denoted by arrows. ( C ) A large dome at 42° N, 10° E, visible in the elevation map. ( D ) A small mound at 45.5° S, 295.7° E. ( E ) Type 1 lobate flow; arrows point to the flow front. Analysis of Dawn spacecraft Framing Camera image data allows evaluation of the topography and geomorphology of features on the surface of Ceres. The dwarf planet is dominated by numerous craters, but other features are also common. Linear structures include both those associated with impact craters and those that do not appear to have any correlation to an impact event. Abundant lobate flows are identified, and numerous domical features are found at a range of scales. Features suggestive of near-surface ice, cryomagmatism, and cryovolcanism have been identified. Although spectroscopic analysis has currently detected surface water ice at only one location on Ceres, the identification of these potentially ice-related features suggests that there may be at least some ice in localized regions in the crust. [1]: pending:ye
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