Landscape science: a Russian geographical tradition

The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia's own distinctive tradition in environmental science deriving from the work of V. V. Dokuchaev (1846-1903), the activities of certain key individuals (such as Berg and C. O. Sauer), and the very different social and political circumstances in different parts of the world appear to be the most significant. At the same time it is noted that neither in Russia nor in the West have geographers succeeded in specifying an agreed and unproblematic understanding of landscape, or more broadly in promoting a common geographical conception of human-environment relationships. In light of such uncertainties, the latter part of the article argues for closer international links between the variant landscape traditions in geography as an important contribution to the quest for sustainability

Оценка эффективности лечения новообразований печени по данным КТ и МРТ: дорожная карта для врача лучевой диагностики

The number of available methods for hepatic tumor treatment is steadily increasing. Except traditional surgical resection and systemic chemotherapy there are a lot of effective and increasingly used local methods such as Radiofrequency ablation, cryodestruction, transarterial chemoembolization. Radiologist should be able to assess treatment response and evaluate prognosis. We present review of literature on various systems for hepatic tumor treatment response evaluation. WHO, RECIST 1.0, RECIST 1.1, mRECIST and Choi criteria are thoroughly explained in terms of benefits and drawbacks. Also, texture analysis and diffusion-weighted imaging are discussed.В последние годы выбор различных вариантов терапии образований печени становится все шире, отмечается появление новых вариантов химио- и лучевой терапии. В настоящее время растет количество методов локального воздействия на опухоли, таких как радиочастотная абляция, криодеструкция, трансартериальная эмболизация. Клиническая оценка эффекта терапии не дает необходимого результата, поэтому возрастает потребность в адекватной оценке результатов лечения, основанной на данных методов КТ и МРТ. В данном литературном обзоре приводятся основные критерии оценки эффективности лечения опухолей различными видами воздействия. Отдельно рассматриваются критерии ВОЗ, RECIST, RECIST 1.1, mRECIST, Choi. Помимо этого обсуждаются новые методики объективизации эффектов терапии, основанные на оценке диффузионно-взвешенных изображений и текстурном анализе

Ellipsoidal configurations in the de Sitter spacetime

The cosmological constant $\Lambda$ modifies certain properties of large astrophysical rotating configurations with ellipsoidal geometries, provided the objects are not too compact. Assuming an equilibrium configuration and so using the tensor virial equation with $\Lambda$ we explore several equilibrium properties of homogeneous rotating ellipsoids. One shows that the bifurcation point, which in the oblate case distinguishes the Maclaurin ellipsoid from the Jacobi ellipsoid, is sensitive to the cosmological constant. Adding to that, the cosmological constant allows triaxial configurations of equilibrium rotating the minor axis as solutions of the virial equations. The significance of the result lies in the fact that minor axis rotation is indeed found in nature. Being impossible for the oblate case, it is permissible for prolate geometries, with $\Lambda$ zero and positive. For the triaxial case, however, an equilibrium solution is found only for non-zero positive $\Lambda$. Finally, we solve the tensor virial equation for the angular velocity and display special effects of the cosmological constant there.Comment: 15 pages, 11 figures, published in Class. Quant. Grav. References adde

Theory of diffusional phase transformations in nanocrystalline alloys upon severe plastic deformation: III. Alloys with limited solubility

In the frameworks of the model of regular solid solutions taking into account the different diffusion mobility of the components, the effect of fluxes of nonequilibrium vacancies on the kinetics of decomposition of the alloy is studied. It is shown that the joint action of thermodynamic stimuli of decomposition and the inverse Kirkendall effect gives rise to the precipitation of phases near sources and sinks for vacancies even if the alloy parameters fall into the region of mutual solubility of the components. It has been established that under specific conditions the effect of vacancy fluxes can lead to the formation of special space-time structures (traveling concentration waves). Features of the alloy decomposition upon severe plastic deformation, when grain boundaries serve as sources of nonequilibrium vacancies, are discussed. Copyright © 2005 by Pleiades Publishing, Inc

Theory of Diffusional Phase Transformations in Nanocrystalline Alloys upon Severe Plastic Deformation: II. Decomposition of Nonideal Solid Solutions

A theoretical model of the decomposition of regular solid solutions under the effect of fluxes of non-equilibrium vacancies is developed. The kinetics of the redistribution of the alloy components and the shape of the stationary profiles of the components have been investigated depending on the relationship between the diffusional mobilities of the components, alloy composition, the intensities of fluxes of nonequilibrium vacancies, and the parameters that characterize the interaction of atoms of various types. It is shown that even in the range of thermodynamic stability of the alloy the allowance for the nonideality of the solid solution leads to new qualitative features in the decomposition process. In particular, the degree of decomposition increases with approaching the spinodal; the formation of regions of a fixed composition becomes possible, and in special cases, the precipitation of pure components occurs