18 research outputs found
Lagrange Duality in Set Optimization
Based on the complete-lattice approach, a new Lagrangian duality theory for
set-valued optimization problems is presented. In contrast to previous
approaches, set-valued versions for the known scalar formulas involving infimum
and supremum are obtained. In particular, a strong duality theorem, which
includes the existence of the dual solution, is given under very weak
assumptions: The ordering cone may have an empty interior or may not be
pointed. "Saddle sets" replace the usual notion of saddle points for the
Lagrangian, and this concept is proven to be sufficient to show the equivalence
between the existence of primal/dual solutions and strong duality on the one
hand and the existence of a saddle set for the Lagrangian on the other hand
In vitro and in vivo characterization of neural stem cells
Neural stem cells are defined as clonogenic
cells with self-renewal capacity and the ability to
generate all neural lineages (multipotentiality). Cells
with these characteristics have been isolated from the
embryonic and adult central nervous system. Under
specific conditions, these cells can differentiate into
neurons, glia, and non-neural cell types, or proliferate in
long-term cultures as cell clusters termed
“neurospheres”. These cultures represent a useful model
for neurodevelopmental studies and a potential cell
source for cell replacement therapy. Because no specific
markers are available to unequivocally identify neural
stem cells, their functional characteristics (self-renewal
and multipotentiality) provide the main features for their
identification. Here, we review the experimental and
ultrastructural studies aimed at identifying the
morphological characteristics and the antigenic markers
of neural stem cells for their in vitro and in vivo
identification
Subdifferential and optimality conditions for the difference of set-valued mappings
In this paper, an existence theorem of the subgradients for set-valued mappings, which introduced by Borwein (Math Scand 48:189-204, 1981), and relations between this subdifferential and the subdifferential introduced by Baier and Jahn (J Optim Theory Appl 100:233-240, 1999), are obtained. By using the concept of this subdifferential, the sufficient optimality conditions for generalized D. C. multiobjective optimization problems are established. And the necessary optimality conditions, which are the generalizations of that in Gadhi (Positivity 9:687-703, 2005), are also established. Moreover, by using a special scalarization function, a real set-valued optimization problem is introduced and the equivalent relations between the solutions are proved for the real set-valued optimization problem and a generalized D. C. multiobjective optimization problem