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Homogenization of Linear Parabolic Equations with a Certain Resonant Matching Between Rapid Spatial and Temporal Oscillations in Periodically Perforated Domains

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Acta Mathematicae Applicatae Sinica 2019年第2期35卷 340-358页

作者： tatiana LOBKOVA Department of Mathematics and Science Education Mid Sweden University

In this article, we study homogenization of a parabolic linear problem governed by a coefficient matrix with rapid spatial and temporal oscillations in periodically perforated domains with homogeneous Neumann data on the boundary of the holes. We prove results adapted to the problem for characterization of multiscale limits for gradients and very weak multiscale convergence.

关键词： Homogenization two-scale convergence multiscale convergence periodically perforated domains

Role of social and individual experience in interaction of the meadow ant Formica pratensis （Hymenoptera： Formicidae） with ladybird imagines and hoverfly larvae

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Insect Science 2015年第3期22卷 440-450页

作者： tatiana A. Novgorodova Institute of Systematics and Ecology of Animals Siberian Branch of the Russian Academy of Sciences Frunze str. 11 Novosibirsk 630091 Russia

The ability to recognize aphidophages is one of the key points in the protection ants provide aphids against their natural enemies. Behavior of honeydew collectors from nature （＂field,＂ control） and laboratory reared ＂naive＂ ants of Formica pratensis Retzius, which had never met either ＂mature＂ workers or aphids and aphidophages, was observed during their pairwise interactions with ladybird imagines and hoverfly larvae. The majority of the ＂naive＂ ants perceived ladybirds as an enemy at their first encounter attacking them immediately without any prior antennation. Ants seem to have a certain innate ＂enemy image＂ that lets them react very quickly to protect aphids. Hoverfly larvae were rarely attacked by both ＂field＂ and ＂naive＂ ants （〉 15%）. During tests with ladybirds ants from nature attacked them and also demonstrated the most aggressive reactions （series of bites and ＂death grip＂） less frequently than the ＂naive＂ ants. The percentage of ants avoiding aphidophages after a contact with their chemical defense （reflex bleeding and glue-like saliva） was significantly higher in the control group. Whereas the ＂naive＂ ants did not learn to avoid danger, foragers from nature usually tried to avoid negative experience and used tactics of ＂short bites.＂ Overall, experience has been proved to be unimportant for displaying key behavioral reactions underlying ant-ladybird interaction. However, accumulation of experience has been assumed to play an important role in the formation of behavioral strategy that allows honeydew collectors to drive aphidophages away with lower energy costs and avoid or minimize negative consequences of aphidophages＇ chemical defense.

关键词： ants aphidophages defense enemy recognition Harmonia axyridis Meligramma triangulifera

Effects of long-term medieval agriculture on soil properties:A case study from the Kislovodsk basin,Northern Caucasus,Russia

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Journal of Mountain Science 2018年第6期15卷 1171-1185页

作者： CHERNYSHEVA Elena KHOMUTOVA tatiana FORNASIER Flavio KUZNETSOVA tatiana BORISOV Alexandr Institute of Physicochemical and Biological Problems in Soil Science Russian Academy of Sciences Institutskaya 14229o Pushchino Moscow region Russia 2 CREA - VE Consiglio per la ricerca in Agricoltura e rAnalisi della Economia Agraria Centro di Ricerea Viticoltura ed Enologia Via Trieste 23 34170 Gorizia Italy

The chemical properties and biological activities of soils were studied in the vicinity of the medieval settlement Podkumskoe-3 in the Kislovodsk basin(Northern Caucasus, Russia). Between the 5 th and 8 th centuries this area was ploughed regularly, but it was then abandoned up to the present day. It has been established that past human activity leads to soil undergoing significant transformations in terms of microbial communities and enzyme activity, and that such changes are maintained over long periods. Long-term manuring in the middle of the first millennium AD led to an increase in organic carbon content and the accumulation of nitrate nitrogen. Soils of ancient abandoned fields are associated with increases in microbial biomass, number of saprotrophic bacteria, urease activity, and fungal mycelium biomass. The observed changes in the microbiological and biochemical properties of soil were conditioned by secondary anthropogenically induced succession after the abandonment of arable lands.

关键词： Anthropogenic soils Manuring Enzymeactivity Microbial biomass North Caucasus MiddleAges

ON AUGMENTED LAGRANGIAN METHODS FOR SADDLE-POINT LINEAR SYSTEMS WITH SINGULAR OR SEMIDEFINITE （1, 1） BLOCKS

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Journal of Computational Mathematics 2014年第3期32卷 297-305页

作者： tatiana S. Martynova Computing Center Southern Federal University Rostov-on-Don Russia

An effective algorithm for solving large saddle-point linear systems, presented by Krukier et al., is applied to the constrained optimization problems. This method is a modification of skew-Hermitian triangular splitting iteration methods. We consider the saddle-point linear systems with singular or semidefinite （1, 1） blocks. Moreover, this method is applied to precondition the GMRES. Numerical results have confirmed the effectiveness of the method and showed that the new method can produce high-quality preconditioners for the Krylov subspace methods for solving large sparse saddle-point linear systems.

关键词： Hermitian and skew-Hermitian splitting Saddle-point linear system Constrained optimization Krylov subspace method.

General techniques for constructing variational integrators

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Frontiers of Mathematics in China 2012年第2期7卷 273-303页

作者： Melvin LEOK tatiana SHINGEL Department of Mathematics University of California San Diego La Jolla CA 92093 USA

The numerical analysis of variational integrators relies on variational error analysis, which relates the order of accuracy of a variational integrator with the order of approximation of the exact discrete Lagrangian by a computable discrete Lagrangian. The exact discrete Lagrangian can either be characterized variationally, or in terms of Jacobi＇s solution of the Hamilton- Jacobi equation. These two characterizations lead to the Galerkin and shooting constructions for discrete Lagrangians, which depend on a choice of a numerical quadrature formula, together with either a finite-dimensional function space or a one-step method. We prove that the properties of the quadrature formula, finite-dimensional function space, and underlying one-step method determine the order of accuracy and momentum-conservation properties of the associated variational integrators We also illustrate these systematic methods for constructing variational integrators with numerical examples.

关键词： Geometric numerical integration geometric mechanics symplectic integrator variational integrator Lagrangian mechanics

Land use in agricultural landscapes with chernozems contaminated after Chernobyl accident: Can we be confident in radioecological safety of plant foodstuff?

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International Soil and Water Conservation Research 2019年第2期7卷 158-166页

作者： Olga Komissarova tatiana Paramonova Radioecology&Ecotoxicology Department Soil Science FacultyLomonosov Moscow State UniversityLeninskie Gory 1-12Moscow 119991Russia

Agricultural land use in the area of the post-Chemobyl Plavsk radioactive hotspot (Tula region,Central Russia) has raised a problem of radioecological safety of obtained plant *** of 137Cs activities and inventories in components of 'soil-plant' systems of the territory has been conducted in 2014-2017 in 10 agrosystems and 2 semi-natural *** was revealed that density of 137Cs contamination of arable chernozems and alluvial calcareous soils nowadays varies in a range 140-220 kBq/m2 and exceeds radiation safety standard by^3.5-6 *** plowing of the arable soils up to 30-cm in 1986-1987 resulted in decreasing of 137Cs inventories in rooting zone by ≈ 70% for crops cultivated with shallow disk plowing (wheat,barley),and by ≈ 35% for crops cultivated with middle plowing (buckwheat,amaranth,white mustard).The investigated plants and their compartments can be grouped on the basis of transfer factor values as follows:maize (stems and leaves)> amaranth> bromegrass > vegetation of dry meadow,galega,sunflower (seeds),vegetation of wet meadow > maize (grain),soybean (pods),barley (grain),buckwheat (grain),potatoes (tubers)> white mustard (seeds),wheat (grain).It is noticeable that generative plant compartments are characterized by less 137Cs activities in comparison with stems and leaves;and that 137Cs root uptake is not coincide with total flux of mineral nutrients in 'soil-plant' *** sum,137Cs soil-to-plant transfer in the area of the Plavsk radioactive hotspot is characterized by considerable discrimination,so 137Cs activities in plants are completely in accordance with national standards.

关键词： Radioactive soil contamination Caesium-137 137Cs Arable soils 'Soil-plant' system Chernobyl accident Radioecologically safe land use

Pricing strategies in inelastic energy markets： can we use less if we can＇t extract more？

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Frontiers of Earth Science 2014年第1期8卷 3-17页

作者： Alexey Voinov tatiana Filatova International Institute for Geo-lnformation Science and Earth Observation University of Twente Enschede 7522EA The Netherlands Centre for Studies in Technology and Sustainable Development University of Twente Enschede 7522EA The Netherlands

Limited supply of nonrenewable energy resources under growing energy demand creates a situation when a marginal change in the quantity supplied or demanded causes non-marginal swings in price levels. The situation is worsened by the fact that we are currently running out of cheap energy resources at the global scale while adaptation to climate change requires extra energy costs. It is often argued that technology and alternative energy will be a solution. However, alternative energy infrastructure also requires additional energy investments, which can further increase the gap between energy demand and supply. This paper presents an explorative model that demonstrates that a smooth transition from an oil-based economy to alternative energy sources is possible only if it is started well in advance while fossil resources are still abundant. Later the transition looks much more dramatic and it becomes risky to rely entirely on technological solutions. It becomes increasingly likely that in addition to technological solutions that can increase supply we will need to find ways to decrease demand and consumption. We further argue that market mechanisms can be just as powerful tools to curb demand as they have traditionally been for stimulating consumption. We observe that individuals who consume more energy resources benefit at the expense of those who consume less, effectively imposing price externalities on the latters. We suggest two transparent and flexible methods of pricing that attempt to eliminate price externalities on energy resources. Such pricing schemes stimulate less consumption and can smooth the transition to renewable energy.

关键词： peak oil price externality alternative energy resources EROEI

Changes in the sorption, desorption, distribution, and availability of copper, induced by application of sewage sludge on Chilean soils contaminated by mine tailings

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Journal of Environmental Sciences 2012年第5期24卷 912-918页

作者： tatiana Garrido Jorge Mendoza Francisco Arriagada Faculty of Chemical Sciences and Pharmacy Department of Inorganic and Analytical Chemistry University of Chile

The effect of mine tailings and sewage sludge was evaluated on sorption, desorption, availability and distribution of copper in two soils, one high （sandy soil） and one low in copper （clay soil）. In both soils contaminated by mine tailings the copper sorption capacity and the affinity of the substrate for the metal decreased substantially compared to the uncontaminated soils, however, the sorption remained always high in the clay soil substrates. In the substrates with sandy soil, the high Cu content and lower clay content were determining factors in the lower magnitude of the sorption. Similarly, metal desorption was closely related to these two parameters, and it was higher in clay soil with lower pH. In general, the application of sewage sludge favored the sorption of Cu in soils contaminated and uncontaminated with mine tailings, and in all cases desorption decreased, an effect that remained for at least 30 days. Simple extraction of Cu with CaCl2 and diethylenetriaminepentaacetic acid gave contradictory results, so a careful choice of the procedure is required, depending on the level of metal in the soil and on the acting principle of the extracting agent. In that relation, more complete information on the changes in the metal forms was obtained by application of the sequential extraction procedure proposed by the European Community Bureau of Reference.

关键词： sewage sludge copper sorption mine tailings copper desorption European Community Bureau of Reference sequential extraction

Neuroinflammation,neurodegeneration and regeneration in multiple sclerosis:intercorrelated manifestations of the immune response

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Neural Regeneration Research 2016年第11期11卷 1727-1730页

作者： tatiana Koudriavtseva Caterina Mainero Multiple Sclerosis Clinical and Research Unit Department of Systems MedicineTor Vergata University Athinoula A.Martinos Center for Biomedical Imaging Department of RadiologyMassachusetts General Hospital Harvard Medical School

Multiple sclerosis （MS） is a chronic immune-mediated inflammatory-demyelinating disorder of the central nervous system, with a strong neurodegenerative component. The question whether neurodegeneration in MS is independent or related to neuroinflammation has been long debated, but not yet fully clarified. Furthermore, little is still known on how neuroinflammation and neurodegeneration in MS are related to potential regenerative processes. In this perspective, we briefly discuss main clinical, pathological and experimental evidence on the relationship between neuroinflammation and neurodegeneration in MS, and on their connection with regeneration. We discuss that these processes in MS might represent intercorrelated manifestations of the immune response, especially of the innate immunity.

关键词： multiple sclerosis neuroinflammation neurodegeneration regeneration immune response innateimmunity