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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Annals of operations research 58 (1995), S. 181-200 
    ISSN: 1572-9338
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Economics
    Notes: Abstract The main purpose of this paper is the study of connections between combinatorial and continuous optimization. After reviewing some known results, new ways of establishing connections between the two fields are discussed. Particularly, the importance of connecting combinatorial optimization with the field of variational inequalities is stressed. Related to this, the so-called gap function approach to solve a variational inequality is generalized, showing that methods for nonconvex and combinatorial programming may be useful in the variational field. Duality and further investigations are discussed.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 46 (1990), S. 1060-1063 
    ISSN: 1420-9071
    Keywords: Bursa of Fabricius ; cell culture ; cytokeratin ; REp cells ; electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The REp cells of the bursa follicle medulla of chicken were isolated in vitro. Culture of the REp cells was maintained over a period of 10 days and the cells were observed at 3 and 10 days by means of transmission electron microscopy (TEM) and immunofluorescence. The use of an anticytokeratin monoclonal antibody confirmed their epithelial nature. TEM observations showed the presence of desmonsomes and tonofilaments, which are characteristic of epithelial cells. Furthermore, to some extent the cells regenerated in vitro the network they form in vivo. Though the growth rate becomes slower with time, the features of the REp cells do not significantly change.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The distribution of the NADPH diaphorase activity was studied in mouse Leydig cells by means of light and electron microscopy. When observed by the light microscope, most Leydig cells appeared intensely stained; a few cells (about 10%) showed a slightly positive or apparently negative reaction. The inhibitory effects of NG-nitro-l-arginine and iodonium diphenyl on frozen sections suggest the colocalisation of NADPH diaphorase reaction with nitric oxide synthase. The ultrastructural study revealed that all the Leydig cells were positively stained for NADPH diaphorase; however, a small number of cells displayed weak enzymatic activity. The reaction product was located in the mitochondria, smooth endoplasmic reticulum and lipidic vacuoles, and the nuclear envelope was also stained. The possible meaning of the NADPH diaphorase activity in the Leydig cells of mice was discussed.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of optimization theory and applications 42 (1984), S. 331-365 
    ISSN: 1573-2878
    Keywords: Theorems of the alternative ; optimality conditions ; regularity conditions ; constraints qualification ; separation theorems ; Lagrangian functions ; penalty functions ; duality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract A theorem of the alternative is stated for generalized systems. It is shown how to deduce, from such a theorem, known optimality conditions like saddle-point conditions, regularity conditions, known theorems of the alternative, and new ones. Exterior and interior penalty approaches, weak and strong duality are viewed as weak and strong alternative, respectively.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of optimization theory and applications 44 (1984), S. 363-364 
    ISSN: 1573-2878
    Keywords: Optimality conditions ; regularity ; constraint qualifications ; theorems of the alternative
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Several corrections to Ref. 1 are pointed out.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of optimization theory and applications 59 (1988), S. 525-525 
    ISSN: 1573-2878
    Keywords: Convex functions ; gradients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract A conjecture is made on convex functions. It leads to the problem of characterizing a class of convex functions, which is of interest both from the theoretical point of view and in the field of minimization methods.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of optimization theory and applications 55 (1987), S. 233-256 
    ISSN: 1573-2878
    Keywords: Theorems of the alternative ; multifunctions ; Lagrange multipliers ; calculus of variations ; separation theorems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Theorems of the alternative and separation theorems have been shown to be very useful concepts in constrained extremum problems (see, for instance, Refs. 1–12). Their use has stressed the concept of image of a constrained extremum problem, which has turned out to be a powerful and promising tool for investigating the main aspects of optimization (see Refs. 13 and 19). It should be pointed out that, in this approach, a finite-dimensional image problem can be associated to the given extremum problem, even if this is infinite-dimensional and provided that its constraints are expressed by functionals. Such a development can be carried on by means of theorems of the alternative for systems of single-valued functions. In this paper, theorems of the alternative for systems of multifunctions are studied, some general properties are stated, and connections with known results investigated. It is shown how the present approach can be used to analyze extremum problems, where the image of the domain of the constraining functions belongs to a functional space. Such a development will be carried on in a subsequent paper.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of optimization theory and applications 60 (1989), S. 191-241 
    ISSN: 1573-2878
    Keywords: Nonsmooth optimization ; necessary conditions ; semi-differentiable functions ; Lagrange multipliers ; generalized derivatives ; image space ; Euler equation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract In the last two decades, there has been an increasing interest in nonsmooth optimization, both from a theoretical viewpoint and because of several applications. Necessary optimality conditions, as well as other important topics, have received new attention (see, for instance, Refs. 1–11 and references therein). In recent papers (see, for instance, Refs. 12–18 and references therein), theorems of the alternative for generalized systems have been studied and their use in optimization has been exploited. As a consequence of this analysis, the concept of image of a constrained extremum problem has been developed; such a concept, whose introduction goes back to the work of Carathéodory, has only recently been recognized to be a powerful tool (Refs. 8, 10, 13, 14, 18–21). On the basis of these ideas, in the present paper we deal with a necessary condition for constrained extremum problems having a finite-dimensional image, while those having an infinite-dimensional one will be treated in a subsequent paper. The necessary condition is established within a class of semidifferentiable functions, which is introduced here and which embraces several classic types of functions (e.g., convex functions, differentiable functions, and even some discontinuous functions). The condition embodies the classic theorems of Lagrange, John, Karush, Kuhn-Tucker, and Euler.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of global optimization 12 (1998), S. 215-223 
    ISSN: 1573-2916
    Keywords: Optimal control ; Exact penalization ; Directional differentiability ; Subdifferentiability ; Necessary optimality conditions ; Nonsmooth analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The nonsmoothness is viewed by many people as at least an undesirable (if not unavoidable) property. Our aim here is to show that recent developments in Nonsmooth Analysis (especially in Exact Penalization Theory) allow one to treat successfully even some quite ‘smooth’ problems by tools of Nonsmooth Analysis and Nondifferentiable Optimization. Our approach is illustrated by one Classical Control Problem of finding optimal parameters in a system described by ordinary differential equations.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 221 (1981), S. 67-75 
    ISSN: 1432-0878
    Keywords: Bursa of Fabricius ; FAE cells ; Carrageenan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les cellules épithéliales associées aux follicules lymphatiques (FAE) de la bourse de Fabricius du poulet, dotées d'activités enzymatiques et de capacités micropinocitosiques, expriment des fonctions qui, d'une certaine manière, rappellent celles des macrophages. Sur base de cette constatation, on a cherché à évaluer si les cellules FAE sont sensibles à une substance notoirement macrophage-toxique comme la carragénine. Cette substance a été introduite dans le lumière de la bourse de Fabricius où on l'a fait séjourner pendant 72–120. Les bourses de Fabricius prélevées après un tel traitement ont été examinées en employant des méthodes histologiques et histochimiques, qui ont évidencié une réduction des zones FAE avec modification de leur aspect. Les résultats indiqueraient une sensibilité des cellules FAE à la carragénine. Sur un groupe d'animaux traités avec la même substance, on a étudié le comportement immunologique en ce qui concerne SRBC. On observe une hausse des agglutinines et du nombre PFC directes/rate anti-SRBC par rapport aux contrôles non traités avec la carragénine. Sur base des résultats morphologiques et immunologiques, on discute la nature et le rôle des cellules associées aux follicules de la bourse de Fabricius du poulet.
    Notes: Summary The lymphoid-follicle associated epithelial (FAE) cells of the bursa Fabricii of chickens show enzymatic and micropinocytotic activities; they can perform functions reminiscent of those of macrophages. To test this relationship, we checked whether FAE cells are sensitive to carrageenan, a substance widely known to be toxic for macrophages. This substance was gently introduced into the bursal lumen and was left there for a period of 72 to 120 h. The bursae of Fabricius were then examined histologically and histochemically. The result was that the FAE areas had been reduced in number and that their structural pattern had been modified. This effect suggests that FAE cells may be sensitive to carrageenan. The immunological response to SRBC was studied in one group of animals that had received carrageenan. The antibody seemed to elicit an increase in the agglutinins and in the number of direct PFC/spleen against SRBC in comparison with control chickens. On the basis of the morphological and immunological results obtained, the origin and the role of the FAE cells of the bursa of Fabricius are discussed.
    Type of Medium: Electronic Resource
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