5,623 research outputs found
On Increasing of Resolution of Satellite Images via Their Fusion with Imagery at Higher Resolution
In this paper we propose a new statement of the spatial increasing resolution problem of MODIS-like multi-spectral images via their fusion with Lansat-like imagery at higher resolution. We give a precise definition of the solution to the indicated problem, postulate assumptions that we impose at the initial data, establish existence and uniqueness result, and derive the corresponding necessary optimality conditions. For illustration, we supply the proposed approach by results of numerical simulations with real-life satellite images.In this paper we propose a new statement of the spatial increasing resolution problem of MODIS-like multi-spectral images via their fusion with Lansat-like imagery at higher resolution. We give a precise definition of the solution to the indicated problem, postulate assumptions that we impose at the initial data, establish existence and uniqueness result, and derive the corresponding necessary optimality conditions. For illustration, we supply the proposed approach by results of numerical simulations with real-life satellite images
Gauge symmetries of strings in supertwistor space
Recently we have considered supertwistor reformulation of the D=4 N=1,2
superstring action that comprises Newman-Penrose dyad components and is
classically equivalent to the Green-Schwarz one. It was shown that in the
covariant kappa-symmetry gauge the supertwistor representation of the string
action simplifies. Here we analyze its Hamiltonian formulation, classify the
constraints on the phase-space variables, and find the covariant set of
generators of the gauge symmetries. Quantum symmetries of the supertwistor
representation of the string action are examined applying the world-sheet CFT
technique. Considered are various generalizations of the model from the
perspective of their possible relation to known twistor superstring models.Comment: 17 pages, LaTeX; v.2 minor changes in the text, references added,
misprints correcte
Finite Temperature QCD with Two Flavors of Non-perturbatively Improved Wilson Fermions
We study QCD with two flavors of non-perturbatively improved Wilson fermions
at finite temperature on the lattice. We determine the transition
temperature at lattice spacings as small as fm, and study string
breaking below the finite temperature transition. We find that the static
potential can be fitted by a two-state ansatz, including a string state and a
two-meson state. We investigate the role of Abelian monopoles at finite
temperature.Comment: 29 pages, 22 figures, Late
(Super)twistors and (super)strings
The Lagrangian formulation of the D=4 bosonic string and superstring in terms
of the (super)twistors is considered. The (super)twistor form of the equations
of motion is derived and the kappa-symmetry transformation for the
supertwistors is given. It is shown that the covariant kappa-symmetry gauge
fixation results in the action quadratic in the (super)twistor variables.Comment: LaTeX, 17 page
Effect of extracts from microalgae on cytokine levels in female C57Bl6 mice
Microalgae from the freshwater basins and seas are a valuable source of broad-spectrum biologically active substances that can affect the cells of immune system and their functional state. Cytokines are involved in all vital processes proceeding in the living cells (proliferation, maturation, differentiation, apoptosis/ necrosis). A study was performed in order to assess the effects of standard food formula for experimental animals supplemented with oil extract of microalgae from various systematic groups upon the levels of cytokines in blood serum, culture media conditioned by immunocytes, as well as kidney and liver tissues. The standard food was impregnated in oil extracts of microalgae (C. vulgaris, Coelastrella sp., A. platensis, C. closterium, and P. purpureum). In control series, the food was impregnated with pure vegetable oil. The animals were fed these foods for 12 days. Blood, spleen and thymus were taken to isolate immunocytes, kidneys and liver, and dimethyl sulfoxide extracts of the cells were produced. The conditioned media of splenocytes and thymocytes were obtained by adding concanavalin A (0 and 10 μg/ml) to the cultured cells. The levels of NO, IL-1β, IL-10, TNFα, and NO were determined in serum, conditioned media, and tissue extracts. In serum, the influence of microalgae on the levels of IL-1β and TNFα was revealed. Activation of immunocytes in experimental groups was followed by changes in IL-1β, TNFα and IL-10 production. Changes of cytokine and NO levels were revealed in liver and kidney extracts in experimental groups. Thus, microalgae extracts of various systematic groups affect the levels of cytokines in blood serum, cultural media conditioned by splenocytes and thymocytes, kidney and liver tissues
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