Search

A constructive method for solving the linear-quadratic problem of the optimal control of a parabolic-type system with distributed parameters is proposed under the condition of the uniform estimation of the target sets. The optimality criterion takes the form of an integral quadratic estimate of the controlled state function in the spatiotemporal domain of its definition. A parameterized representation of the control inputs is given with the required accuracy within special intervals of the optimal process, where the control inputs cannot be determined using first-order analytical optimality conditions. The proposed approach is based on the previously developed alternance method for constructing parameterized algorithms of programmed control, which heavily relies on the fundamental regularities of the subject area. It is demonstrated that the equations of the optimal regulators within the special intervals are reduced to the linear feedback algorithms based on the measured states of the objects. These algorithms are supplemented with switches at the boundary points to apply the admissible control inputs corresponding to the calculated values of the controlled variable. [ABSTRACT FROM AUTHOR]

We propose a method for synthesizing energy-optimal controllers in open and closed domains of space-time control actions for linear multidimensional objects with distributed parabolic parameters under the conditions of a given accuracy of uniform approximation of the final state of the system to the desired spatial distribution of the controlled variable. The approach is based on the previously developed alternance method for constructing parameterizable algorithms of optimal program control, which uses the fundamental laws of the subject area. It is shown that the desired equations of the controllers are reduced to linear feedback laws with restrictions on incomplete observation of the state of the object with nonstationary transmission coefficients, which are determined by preliminary calculation of the program control action. [ABSTRACT FROM AUTHOR]

A constructive method is proposed for solving a linear-quadratic problem of the robust optimization of spatiotemporal control actions in systems with distributed parabolic parameters under conditions of interval uncertainty of the time-invariant parametric characteristics of an object. In accordance with the control strategy according to the principle of the best guaranteed result, the assessment of achievable target sets of the controlled system is carried out according to the accuracy of uniform approximation to the required final state on an extended set of arguments, which includes, in addition to spatial variables, the entire admissible set of uncertain factors. The developed approach is based on the previously developed alternance method for constructing parameterizable program control algorithms, which extends the results of the theory of nonlinear Chebyshev approximations to a wide range of optimization problems and uses the fundamental laws of the subject area. It is shown that the proposed equations of optimal controllers, which are reduced to linear feedback laws on the measured state of the object with nonstationary transmission coefficients, lead to achievable values of the optimality criteria that do not exceed their upper bounds under the considered uncertainty conditions. [ABSTRACT FROM AUTHOR]

Many important aspects of intercellular glycosphingolipid (GSL) transport remain unknown, in particular how GSLs cross the glycocalyx of the cell-donor and cell-acceptor. The use of synthetic analogs instead of natural GSLs alleviates the study. However, in order to obtain adequate results, we must know how simplifications in the structure of a synthetic probe affect its properties of interest to us. In particular, how the replacement of a ceramide residue in GSL with a synthetic analog affects the release and insertion kinetics. To this end, we compared the properties of synthetic analogs, one of which contains natural ceramide moiety, while two others have lipid residues that are more convenient in terms of the probes chemical synthesis. FSL (Function-Spacer-Lipid) constructs containing DOPE (1,2-O-dioleoyl-sn-glycero-3-phospho ethanolamine), cholesterol (Chol), or C18-ceramide (Cer) lipid fragments (L) were compared. In all three probes, the lipid residues were linked to biotin with the hydrophilizing CMG2-spacer-arm. Using confocal microscopy, the similarity of the localization patterns of these three probes, both with each other and with the previously studied glycoprobes (F = glycan), was shown, namely: they were observed in the form of patches of an average size of 0.3 μm but were not detected at all in cell rafts. At the same time, the following differences were observed in the properties of the three studied FSLs: (1) the process of insertion of the ceramide construct reaches a plateau within three hours, while the other two within one hour; (2) the amount of inserted ceramide construct is less than the other two; and (3) release of the cholesterol construct from the cells where it is preinserted is slower than the other two. Thus, despite some quantitative differences, qualitatively all three constructs behave similarly, that is, they are interchangeable when studying the incorporation/release of the FSL into/from the cell. [ABSTRACT FROM AUTHOR]

A constructive method is proposed for solving a linear-quadratic spatiotemporal control problem in systems with distributed parabolic parameters under the conditions of the given accuracy of uniform approximation of the final state of a plant to the required spatial distribution of the controlled variable. The developed approach is based on the previously developed alternance method for constructing parameterizable programmed control algorithms, which extends the results of the theory of nonlinear Chebyshev approximations to a wide range of optimization problems and uses the fundamental laws of the subject area. It is shown that the equations of optimal controllers with autonomous modal controls in the open domain of their definition and taking into account restrictions on the nature of the spatial distribution of the control actions specified by the conditions of technical implementation are reduced to linear feedback algorithms for the measured state of the plant with nonstationary transmission coefficients and the given dependence on the spatial arguments of the controlled value. The results obtained are extended to the problem of searching for time-invariant spatially distributed controls, considered as the desired design solutions for a plant. [ABSTRACT FROM AUTHOR]

A constructive method is proposed for solving the problem of time-optimal two-channel boundary control of two physically inhomogeneous objects with distributed parameters described by linear heat conduction equations under conditions of a perfect thermal contact of interacting media with estimates of the target sets of controlled temperature fields in a uniform metric that are typical for engineering applications. The developed technique uses a special method for describing the studied temperature fields in a form containing uniformly converging series. The approach under development is based on the parameterization procedure for the desired control actions and the subsequent reduction to the problem of semi-infinite optimization, which is solved by the scheme of the alternance method under the additional restriction on the same duration of the control process for both control actions. [ABSTRACT FROM AUTHOR]

We consider the problem of optimal control of movable objects with distributed parameters according to standard performance criteria, as applied to the actual optimization problem of the operational temperature modes for continuous process units for preheating semifinished products before subsequent pressure treatment. The energy-optimal distributions of the heat release power along the length of the heater in stationary modes of its operation, which serve as the desired design solutions for the plant, are determined. Algorithms for automatic programmed and positional control of operational transient modes of a heating unit are proposed that are optimal in terms of a standard quadratic quality criterion for a given accuracy of the uniform approximation of the final spatial temperature distribution to the required one. It is shown that the procedure for synthesizing an optimal controller is reduced to constructing a control system with linear feedback based on an incomplete measurement of the state of the plant with nonstationary transmission coefficients determined by a preliminary calculation of the programmed control. [ABSTRACT FROM AUTHOR]

A method for analytical construction of optimal regulators in problems of energy-efficient control of linear distributed parameters systems under conditions of a given accuracy of the uniform approximation of the terminal state of the object to the required spatial distribution of the controlled quantity is proposed. The developed approach is based on the previously designed alternance method of constructing parameterized algorithms of optimal programmed control. It is shown that the sought procedure of optimal regulator design is reduced to constructing a linear feedback control system by incomplete measurement of the state. The feedback transfer coefficients are known functions of time and finite values of the controlled quantity which are determined by preliminary calculation of the programmed control action. [ABSTRACT FROM AUTHOR]

A constructive method for synthesizing the optimal control of deterministic and not completely determined systems with distributed parabolic parameters under the conditions of the prescribed accuracy of a uniform approximation of the terminal plant state to the required spatial distribution of the controlled variable is proposed. This approach is based on the earlier developed alternance method for constructing optimal open-loop control algorithms, which extends the results of the theory of nonlinear Chebyshev approximations to a wide range of parameterizable optimal control problems and takes into account fundamental features of the domain. It is shown that the optimal controller equations are reduced to linear output feedback equations with time-dependent coefficients that are calculated based on incomplete measurements of the system's state with an error that decreases as the number of modal components of the controlled variable that are taken into account increases. [ABSTRACT FROM AUTHOR]

Abstract—When studying various technologies and their synthesis, a holistic system-oriented approach is preferable, which provides a solution to the problem of the systems under study for various conditions. It has been established that the productivity in recent years in Siberia increases without development; an increase in costs per unit area leads to an increase in yield but does not reduce the cost per unit of production. To increase the yield, sophistication is necessary: the modernization of the proposed technological solutions through the use of agricultural technologies of various levels of intensity based on new scientific and technical achievements. The results of the work made it possible to obtain research methods for agricultural technologies for managing the productivity of agrocenoses (using the example of the cultivation of grain crops in Siberia). Limited resources often do not allow using more efficient technologies of different levels of intensity to increase the yield of grain crops. The use of various methods of mathematical analysis, probability theory, and linear programming methods, based on the data of experimental studies carried out for irrigated and rainfed agriculture, made it possible to develop algorithms and nomograms to search for technologies that provide more efficient ways of cultivating grain crops. It is known that the yield is an integral indicator of the efficiency of agriculture. The random nature of this indicator requires the use of different distribution laws. The most effective, from our point of view, was the use of Euler functions, in particular, the Euler's beta function. This made it possible, using the example of experimental data for the average yield of grain crops in the amount of 30 c/ha (which is the generally accepted average world yield for grain crops), to construct effective algorithms for choosing sets of intensity levels of technologies for cultivating agrocenoses. The cost function is determined, the value of which is in good agreement with the experimental data (costs) obtained for irrigated agriculture. It is generally recommended to consider four intensity levels of agricultural technologies. However, for the conditions of Western Siberia (according to Siberian Federal Scientific Center of Agrobiotechnology, Russian Academy of Sciences), it is recommended to consider three levels. [ABSTRACT FROM AUTHOR]

The solution of the inverse problem of technological physics is considered as a problem of the optimal control of an object with distributed parameters based on the Pontryagin maximum principle for an infinite-dimensional object formulated as necessary optimality conditions. The inverse problem of heat conduction is formulated in the uniform metric of estimation of the error in the description of the state function of the studied object and is reduced to the problem of the optimal control of an infinite-dimensional object with an integral quality functional and an extended state vector, for which the nature of the optimal control action is established with the Pontryagin maximum principle. The maximum principle method, which takes into account the relations that ensure that the solution belongs to a given compact set, makes it possible to obtain a parametric representation of the identified lumped or spatially distributed characteristics. [ABSTRACT FROM AUTHOR]

A constructive solution of the optimal energy-efficient programmed control problem for distributed parameter systems with a given-precision uniform approximation of the space distribution of the controlled variable with respect to the desired state is proposed. The computational algorithm developed below involves a special-form preliminary parametrization procedure for control actions on finite-dimensional subsets of the terminal values of conjugate variables in the boundary-value problem of Pontryagin's maximum principle, in combination with the subsequent reduction to a semi-infinite optimization problem, which is solved with respect to the requisite parameter vector using the alternance method suggested earlier. An example of optimal energy-efficient control of transient heat conduction, which is of independent interest, is given. [ABSTRACT FROM AUTHOR]

We propose a constructive technology for solving parametrizable problems of multichannel optimal control in systems with distributed parameters under conditions of a given accuracy of uniform approximating the resultant spatial distribution of the controlled variable to the desired state. The developed technique uses the parametrization procedure of the sought control actions and the subsequent reduction to the special form of the task of semi-infinite optimization, which is solved by the scheme of the alternance method proposed earlier; this scheme is generalized to the investigated situation. We present an example (which is of interest by itself) of time-optimization of the process of nonstationary heat conductivity with two boundary control actions. [ABSTRACT FROM AUTHOR]

The previously developed technology of multi-objective optimization of deterministic systems with distributed parabolic parameters can be applied in typical situations with interval uncertainties of parametric characteristics of controlled plants. Minimax problems of mathematical programming are formed in accordance with a control strategy based on the principle of the best guaranteed result of a expanded set of arguments, which includes all permissible realizations of uncertain factors, in the case of estimating a given accuracy of approximation to a required finite system state in uniform metric. These problems are solved by an alternance method that uses the Chebyshev properties of desired extermals and fundamental laws of the problem domain. This paper also presents an example of multi-objective optimization of temperature modes of induction heating of metallic semifinished products before plastic deformation operations in technological complexes for pressure treatment of metal, which is of independent interest. [ABSTRACT FROM AUTHOR]

A constructive technology of the solution of the parametrized problems of the programmed optimal control of systems with the distributed parameters under the conditions of different requirements for the permissible deviation of the resulting spatial distribution of the controlled value from the set magnitude in the uniform metric is proposed. The developed technique uses a special procedure of the one-criterion convolution of the considered constraints and the subsequent reduction to the typical form of the problems of mathematical programming on the extremum of a function of a finite number of variables with an infinite number of constraints (semi-infinite optimization problem), which is solved by the scheme of the previously developed alternance method. An example of optimization by the criteria of the speed and energy consumption of unsteady heat conduction processes with two different restrictions on the accuracy of approximation to the given temperature conditions, which is of independent interest, is given. [ABSTRACT FROM AUTHOR]

Galectins are involved in various biological processes, e.g. cell-cell and cell-matrix adhesion and the transmission of cellular signals. Despite the diversity of functions, little is known about the nature of their physiological cognate ligands on the cell surface and the localization of galectins in the glycocalyx, although this information is important for understanding the functional activity of galectins. In this work, localization of endogenous and exogenously loaded galectins in the glycocalyx was studied. The following main conclusions are drawn: 1) galectins are not evenly distributed within the glycocalyx, they are accumulated in patches. Patching is not the result of a cross-linking of cellular glycans by galectins. Instead, patch-wise localization is the consequence of irregular distribution of glycans forming the glycocalyx; 2) galectins are accumulated in the inner zone of the glycocalyx rather than at its outer face or directly in vicinity of the cell membrane; 3) patches are not associated with cell rafts. [ABSTRACT FROM AUTHOR]

The previously developed methods for analyzing the controllability of linear multidimensional plants with distributed parameters on a given set of open-loop trajectories of their transfer into the desired finite state are extended to interconnected physically heterogeneous distributed dynamic systems. An example (which is of independent interest) of estimating the open-loop controllability of nonstationary heat conduction processes under the conditions of the perfect contact of the interacting environments is presented. [ABSTRACT FROM AUTHOR]

A constructive technology of multi-objective optimization of control of distributed parameter plants is proposed. The technology is based on a single-criterion version in the form of the minimax convolution of normalized performance criteria. The approach under development is based on the transition to an equivalent form of the variational problem with constraints, with the problem solution being a priori Pareto-effective. Further procedures of preliminary parameterization of control actions and subsequent reduction to a special problem of semi-infinite programming make it possible to find the sought extremals with the use of their Chebyshev properties and fundamental laws of the subject domain. An example of multi-objective optimization of operation modes of an engineering thermophysics object is presented, which is of independent interest. [ABSTRACT FROM AUTHOR]

A constructive method for the design and real-time implementation of parameterized open-loop controls in the optimal feedback control of ensembles of trajectories of incompletely determined parabolic systems with distributed parameters is proposed. This method uses reduction to semiinfinite optimization problems, alternance properties of their solutions, and additional information about fundamental laws of the application domain. The practical application of the results is illustrated by the example of controlling nonstationary temperature fields under multiple disturbances, which is a problem of independent interest. [ABSTRACT FROM AUTHOR]

This work is devoted to a possible way to construct time-optimal closed systems for incompletely determined linear models of distributed-parameter control plants of parabolic type, which provides real-time identification of their parametric characteristics according to the results of monitoring the state of the plants. The structural-parametric synthesis of the proposed controllers is based on the alternance method of designing optimal software controls. The paper gives an example (of independent interest) of constructing a time-optimal system for the control of the process of induction heating under typical conditions of interval uncertainty of the initial temperature and heat losses. [ABSTRACT FROM AUTHOR]

Galectins are ß-galactoside-binding proteins sharing homology in amino acid sequence of their carbohydraterecognition domain. Their carbohydrate specificity outside cells has been studied previously. The main conclusion of these studies was that several levels of glycan ligand recognition exist for galectins: (i) disaccharide Galß1-4GlcNAc (LN, Nacetyllactosamine) binds stronger than ß-galactopyranose; (ii) substitution at 0 -2 and 0 -3 of galactose residue as well as core fragments ('right' from GlcNAc) provides significant increase in affinity; (iii) similarly glycosylated proteins can differ significantly in affinity to galectins. Information about the natural cellular receptors of galectins is limited. Until recently, it was impossible to study specificity of cell-bound galectins. A model based on controlled incorporation of a single protein into glycocalyx of cells and subsequent interaction of loaded cells with synthetic glycoprobes measured by flow cytometry made this possible recently. In this review, data about glycan specificity of proto-, chimera-, and tandem-repeat type galectins on the cell surface are systematized, and comparative analysis of the results with data on specificity of galectins in artificial systems was performed. The following conclusions from these studies were made: (i) cellular galectins have practically no ability to bind disaccharide LN, but display affinity to 3'-substituted oligolactosamines and oligomers LN; (ii) tandem-repeat type galectins recognize another disaccharide, namely Galß1-3GlcNAc (Le); (iii) on the cell surface, tandemrepeat type galectins conserve the ability to display high affinity to blood group antigens of ABH system; (iv) in general, when galectins are immersed into glycocalyx, they are more selective regarding glycan interactions. Thus, we conclude that competitive interaction of galectins with cell microenvironment (endogenous cell glycans) is the main factor providing selectivity of galectins in vivo. [ABSTRACT FROM AUTHOR]

The problem of controllability of linear multidimensional models of dynamical systems with distributed parameters is considered for a given set of open-loop trajectories that transfer the plant into the terminal state. Based on the behavior of these trajectories in the spatial and temporal domain, we obtain necessary and sufficient conditions (that can be directly checked) for the existence of various technologically feasible controls ensuring that the necessary requirements are met. Using the methods proposed in this study, we give examples (which are of independent interest) for estimating the open-loop controllability of nonstationary heat conduction processes. [ABSTRACT FROM AUTHOR]

Galectins are multifunctional effectors, for example acting as regulators of cell growth via protein-glycan interactions. The observation of capacity to kill bacteria for two tandem-repeat-type galectins, which target histo-blood epitopes toward this end (Stowell et al. Nat. Med. 16:295-301, ), prompted us to establish an array with bacterial polysaccharides. We addressed the question whether sugar determinants other than β-galactosides may be docking sites, using human galectins-4, -8, and -9. Positive controls with histo-blood group ABH-epitopes and the E. coli 086 polysaccharide ascertained the suitability of the set-up. Significant signal generation, depending on type of galectin and polysacchride, was obtained. Presence of cognate β-galactoside-related epitopes within a polysaccharide chain or its branch will not automatically establish binding properties, and structural constellations lacking galactosides, like rhamnan, were found to be active. These data establish the array as valuable screening tool, giving direction to further functional and structural studies. [ABSTRACT FROM AUTHOR]

Background: Cannabis is the most frequently used illegal substance in the United States and Europe. There is a dramatic increase in the demand for treatment for cannabis dependence. Cannabis users frequently have co-morbid mood symptoms, especially depression and anxiety, and regular cannabis users may self-medicate for such symptoms. Objectives: We report a double-blind, placebo-controlled treatment study, for the prevention of cannabis use in cannabis-dependent individuals. Method: Regular cannabis-dependent users ( n = 52) were treated for 9 weeks with weekly cognitive-behavior and motivation-enhancement therapy sessions together with escitalopram 10 mg/day. Urine samples were collected to monitor delta-9 tetrahydrocannabinol (THC) during treatment and questionnaires were administered to assess anxiety and depression. Results: We observed a high rate of dropout (50%) during the 9-week treatment program. Fifty-two patients were included in the intention-to-treat analysis. Of these, ten (19%) remained abstinent after 9 weeks of treatment as indicated by negative urine samples for THC. Escitalopram provided no advantage over placebo in either abstinence rates from cannabis or anxiety and depression scores during the withdrawal and abstinent periods. Conclusions: Escitalopram treatment does not provide an additional benefit either for achieving abstinence, or for the treatment of the cannabis withdrawal syndrome. Due to limitations of our study, namely, a high dropout rate and effects of low abstinence rates on measures of anxiety, depression and withdrawal, it is premature to conclude that selective serotonin reuptake inhibitors are not effective for treatment of the cannabis withdrawal syndrome. [ABSTRACT FROM AUTHOR]

A method is proposed to solve the joint optimization problem based on system quality criteria for the thermophysical processes of preheating and subsequent plastic deformation of metal semi-finished products in industrial metal working systems with a free choice of the admissible initial temperature states before plastic deformation that integrate these processes in a single process system. Potentials for practical applications of the method is illustrated by the example of a process system for forming pressed articles from aluminum alloys. [ABSTRACT FROM AUTHOR]

The minimization problem for deviations of the stationary state of a system with distributed parameters from a desired state estimated in the uniform metric is considered. A constructive method for its solution using a successive parameterization of controls and the alternance properties of optimal spatial distributions of the controlled variable is proposed. Examples of the use of the proposed computational scheme of the organization of computational algorithms in optimization problems of stationary thermal conductivity processes are discussed. [ABSTRACT FROM AUTHOR]

We study the best approximation (in the Kantorovich-Rubinshtein metric) of continuous measures on the straight line by measures concentrated at finitely many points. Some algorithm for obtaining these measures is constructed, and the questions of their existence and uniqueness are considered. Applications of the results to some problems of mathematical economics are studied. [ABSTRACT FROM AUTHOR]

The piecewise continuous (relay) nature of lumped control actions in problems of timeand energy-optimal control of a wide range of distributed-parameter nonlinear objects of engineering thermophysics is established. On this basis, the required programmed controls in a number of practical situations can be found by the proposed algorithmically precise (alternance) method. As an example, which is of independent interest, the problem of optimal control of nonlinear models of induction heating of metal semi-products before subsequent pressure treatment is considered. [ABSTRACT FROM AUTHOR]

The problem of analytical construction of aggregated automatic controllers for various types of control actions in systems with distributed parameters described by parabolic partial differential equations is considered. Synthesis algorithms based on the proposed forms of aggregated macro-variables are studied. A boundary control system for the process of non-stationary thermal conductivity is constructed to illustrate the results. [ABSTRACT FROM AUTHOR]

The network of adhesion/growth-regulatory galectins in chicken (chicken galectin, CG) has only one tandemrepeat-type protein, CG8. Using a cell-based assay and probing galectin reactivity with a panel of fluorescent neoglycoconjugates (glycoprobes), its glycan-binding profile was determined. For internal validation, human galectin-8 (HG8) was tested. In comparison to HG8, CG8 showed a rather similar specificity: both galectins displayed high affinity to blood group ABH antigens as well as to 3′-sialylated and 3′-sulfated lactosamine chains. The most remarkable difference was found to be an ability of HG8 (but not CG8) to bind the disaccharide Galβ1-3GlcNAc (Le) as well as branched and linear oligolactosamines. The glycan-binding profile was shown to be influenced by glycocalix of the cell, where the galectin is anchored. Particularly, glycosidase treatment of galectin-loaded cells led to the change of the profile. Thus, we suppose the involvement of cis-glycans in the interaction of cell-anchored galectins with external glycoconjugates. [ABSTRACT FROM AUTHOR]

Influenza virus is known to bind sialoglycans located on the surface of the host cell. In addition, recent data suggest the involvement of other molecular targets in viral reception. Of note, a high density of terminal galactose residues is created on the surface of virions because of the influenza virus' own neuraminidase activity. Thus, we suggested the possibility for an interaction of the influenza virus with galactose-binding proteins - galectins. In the present work we studied the influence of several galectins on the adhesion and further internalization of virus into the cell; six virus strains and three cell lines were studied. Chicken galectins CG-1A and -2 as well as human galectins HGal-1 and -8 promote virus binding in dose dependent manner, but they do not influence the internalization stage. Also, galectins are able to restore the ability of influenza virus to infect desialylated cells up to the level of native cells. When CG-1A in physiological concentrations was loaded onto viruses, the adhesion level was higher than in the case of on-cell loading. The effect of adhesion increase depends on the glycan structure of target-cell as well as of virus. The aggregated data suggest a promotional effect of galectins during the stage of influenza virus binding with the surface of target-cell. [ABSTRACT FROM AUTHOR]

Under study is a dynamical system of economics with discrete time whose states at each moment correspond to nonnegative integer points of a two-dimensional vector space. There are two types of products and two facilities each of which can change the state of the system by random integer vectors with different collections of probabilities. By a control we understand the choice at each moment of time of one available collection of probabilities. The goal of control is to minimize the probability of leaving the positive quadrant. The question is considered of the existence of some prices that agree with an optimal control. [ABSTRACT FROM AUTHOR]

We have recently shown that the carbohydrate-binding pattern of galectins in cells differs from that determined in artificial (non-cellular) test-systems. To understand the observed discrepancy, we compared several test-systems differing in the mode of galectin presentation on solid phase. The most representative system was an assay where the binding of galectin (human galectins-1 and -3 were studied) to asialofetuin immobilized on solid phase was inhibited by polyacrylamide glycoconjugates, Glyc-PAA. This approach permits us to range quantitatively glycans (Glyc) by their affinity to galectin, i.e. to study both high and low affinity ligands. Our attempts to imitate the cell system by solid-phase assay were not successful. In the cell system galectin binds glycoconjugates by one carbohydrate-recognizing domain (CRD), and after that the binding to the remaining non-bound CRD is studied by means of fluorescein-labeled Glyc-PAA. In an “imitation” variant when galectins are loaded on adsorbed asialofetuin or Glyc-PAA followed by revealing of binding by the second Glyc-PAA, the interaction was not observed or glycans were ordered poorly, unlike in the inhibitory assay. When galectins were adsorbed on corresponding antibodies (when all CRDs were free for recognition by carbohydrate), a good concentration dependence was observed and patterns of specificities were similar (though not identical) for the two methods; notably, this system does not reflect the situation in the cell. Besides the above-mentioned, other variants of solid-phase analysis of galectin specificity were tested. The results elucidate the mechanism and consequence of galectin CRD cis-masking on cell surface. [ABSTRACT FROM AUTHOR]

A precise method based on a special procedure of successive parametrization of control actions is proposed to solve boundary-value optimal control problems for distributed-parameter systems with the tolerances for deviations from the required final state of the controlled object specified in the uniform metric. The method is used to solve the time optimal control problem for an innovative technology of induction heating of massive bodies rotating in a direct current magnetic field. [ABSTRACT FROM AUTHOR]

A special procedure for control action parameterization and the precise method based on it for determining open-loop optimal control algorithms for the systems with distributed parameters under the prescribed tolerance conditions for the deviation from the required final state of the controlled parameter being estimated in the uniform metric is proposed. The method uses the reduction to the problems of semi-infinite optimization, alternance properties of their solutions, and some additional information on fundamental regularities of the subject domain. Examples showing an opportunity of using these results for applied problems, constituting also a point of independent interest are presented. [ABSTRACT FROM AUTHOR]

Galectins are a family of β-galactoside binding lectins, homological by a sequence of the carbohydrate-binding site. In this review literature data about structure and carbohydrate specificity of galectins are discussed. The role of galectins in the regulation of cell adhesion in immune response, inflammation, and cancer progression is considered. [ABSTRACT FROM AUTHOR]

The problem of synthesizing automatic controllers for one class of linear plants with distributed parameters is considered from the general point of structural theory of distributed systems. On this basis, methods to construct control algorithms for various modifications of control actions are proposed. The results obtained are illustrated by examples of synthesizing automatic control systems of nonstationary heat conduction processes. [ABSTRACT FROM AUTHOR]

Soluble siglecs-1,-4,-5,-6,-7,-8,-9, and-10 were probed with polyacrylamide glycoconjugates in which: 1) the Neu5Ac residue was substituted by a sulfate group (Su); 2) glycoconjugates contained both Su and Neu5Ac; 3) sialoglycoconjugates contained a tyrosine-O-sulfate residue. It was shown that sulfate derivatives of LacNAc did not bind siglecs-1,-4,-5,-6,-7,-8,-9, and-10; binding of 6′-O-Su-LacNAc to siglec-8 was stronger than binding of 3′SiaLacNAc. The relative affinity of 3′-O-Su-TF binding to siglecs-1,-4, and-8 was similar to that of 3′SiaTF. 3′-O-Su-Lec displayed two-fold weaker binding to siglec-1 and siglec-4 than 3′SiaLec. The interaction of soluble siglecs with sulfated oligosaccharides containing sialic acid was also studied. It was shown that siglecs-1,-4,-5,-6,-7,-9, and-10 did not interact with these compounds; binding of 6-O-Su-3′SiaLacNAc and 6-O-Su-3′SiaTF to siglec-8 was weaker than that of the corresponding sulfate-free sialoside probes. Siglec-8 displayed affinity to 6′-O-Su-LacNAc and 6′-O-Su-SiaLex, and defucosylation of the latter compound led to an increase in the binding. Sialoside probes containing tyrosine-O-sulfate residue did not display increased affinity to siglecs-1 and-5 compared with glycoconjugates containing only sialoside. Cell-bound siglecs-1,-5,-7, and-9 did not interact with 6-O-Su-3′SiaLacNAc, whereas the sulfate-free probe 3′SiaLacNAc demonstrated binding. In contrast, the presence of sulfate in 6-O-Su-6′SiaLacNAc did not affect binding of the sialoside probe to siglecs. 6′-O-Su-SiaLex displayed affinity to cell-bound siglecs-1 and-5; its isomer 6-O-Su-SiaLex bound more strongly to siglecs-1,-5, and-9 than SiaLex. [ABSTRACT FROM AUTHOR]

Sialyl oligosaccharides have long been considered to be the sole receptors for influenza virus. However, according to [1] some viruses are able to grow in sialic-free MDCK cells. Here we attempted to reveal a possible second, non-sialic receptor, hypothesizing the involvement of additional carbohydrate lectin recognition in influenza virus reception process, first of all in situations when a lectin of the host cell could recognize the viral carbohydrate ligand. We tested the presence of galactose- and sialic acid-binding lectins, as well as mannoside- and sulfo- N-acetyllactosamine-recognizing properties of MDCK and Vero cells using polyacrylamide neoglycoconjugates and antibodies. MDCK cells bind galactoside probes stronger than Vero cells, whereas Vero cells bind preferentially sialoside, mannoside and various sulfo-oligosaccharide probes. The probing of viruses with the neoglycoconjugates revealed specific 6′-HSO 3 LacNAc (but not other sulfated oligosaccharides) binding property of A and B human strains. Affinity of 6′-HSO 3 LacNAc probe was comparable with affinity of 6′-SiaLac probe but the binding was not inhibited by the sialooligosaccharide. [ABSTRACT FROM AUTHOR]

Elimination of apoptotic bodies is one of the important functions of macrophages. The aim of this work was to study the role of macrophage lectins in this process. Macrophage lectins were probed with neoglycoconjugates Glyc-PAA-fluo where carbohydrate is linked to fluorescein-labeled polyacrylamide (MW 30 kD). It was shown that neoglycoconjugates containing a Neu5Aca2-3Gal fragment bound to macrophages isolated from blood of healthy donors. Besides, carbohydrate chains containing the same fragment were revealed on apoptotic bodies. Phagocytosis of apoptotic bodies by macrophages was inhibited with sialooligosaccharide ligands of siglec-5 and MAbs to siglec-5. Thus, siglec-5 expressed on macrophages could participate in phagocytosis of apoptotic bodies. In addition, the role of siglecs in engulfment of apoptotic bodies by tumor-associated macrophages was studied. The phagocytic potency of macrophages isolated from blood of breast cancer patients was lower than engulfment ability of macrophages obtained from healthy donors and depended on tumor degree. Staining of macrophages obtained from blood of tumor patients with sialylated Glyc-PAA-fluo probes was more intense than that of macrophages from healthy donors; phagocytosis of apoptotic bodies by tumor associated macrophages was inhibited by carbohydrates that are known to be ligands for siglecs. [ABSTRACT FROM AUTHOR]

Sprouted barley grains, the waste product of malt extract production, were incriminated as the cause of a lethal (96% mortality) neurotoxic syndrome in sheep fed the grains. Clinical manifestations, comprising tremors, lameness, abnormal gait, paralysis and death indicated a tremorgenic mycotoxicosis. Whilst 50% of the flock died within 17 days, mortality continued over more than 5 months. Pathological findings were limited to neuronal degeneration and necrosis in the midbrain. Germinating grains were shown to be contaminated with growth of Aspergillus clavatus. [ABSTRACT FROM AUTHOR]

Prefixes epi- and Hypo-are proposed for being used with the word neuston as more correct than supra- and infra-. From the aspect of the intestinal content and from the habit of biting the superficial film of water, it is supposed that some Collembola feed on the molecular layer of lipoproteins formed there, or on the bacteria of the hyponeuston Two types of epineuston are recognized: the transitory one, formed on more or less ephemeral water pools after rainfalls, and constituted by hemiedaphic (rarely epi- and cuedaphic) species which were dislodged from their habitats by the pore saturation of the soil and litter. The permanent or epineuston proper, characteristic of bodies of water as lakes, lagoons or ponds contains species of Collembola especially adapted to this kind of life. In the rivers both types of fauna are mixed Samples of epineuston from pools and stream taken dun rig several years were studied, analyzing the causes of this accumulations or swarmings, the variation of its composition, and mortality. Quantitative estimation of the epineuston carried by a stream in the driest season: 7500 arthropods hourly, among which 4000 Collembola. During the rainy season this stream must carry tens or hundreds of thousands per hour. It is concluded that rivers and streams and also floods, act as a way of dispersion for species adapted to float above the surface of water. [ABSTRACT FROM AUTHOR]