Numerous combinatorial optimization problems (knapsack, maximum-weight matching, etc.) can be expressed as subset maximization problems: One is given a ground set $$N=\{1,\dots ,n\}$$ , collection $$\mathcal {F}\subseteq 2^N$$ of subsets thereof such that $$\emptyset \in \mathcal {F}$$ and an objective (profit) function $$p:\mathcal {F}\rightarrow \mathbb {R}_+$$ . The task to choose $$S\in max...

1. As a defect of suppressor function has been hypothesized in the pathogenesis of coeliac disease, we measured, by monoclonal antibodies, the inducer/suppressor T-cell ratio in adult coeliac disease. 2. No statistical difference was observed between coeliac patients and healthy controls, irrespective of treatment and HLA status. 3. These results do not show an imbalance in the inducer/suppress...

We analyze the complexity of vote trading problems with equal-sized voting districts. For two allied vote-swapping parties, the problem is polynomially solvable. For three parties, the problem is NP-complete.

We consider the problem of maximimizing, over all choices of n nonzero elements a 1 ; : : : ; a n 2 R m , the number of the 2 n subset sums P i2I a i , over all index sets I, belonging to some speciied target set T.tigated the case m = 1 and T = f0; 1g of this problem, and showed that the maximum in their case is ? n+1 b n+1 2 c , but it remained open until now to prove the essential uniqueness...

In recent years, knapsack problems for (in general non-commutative) groups have attracted attention. In this paper, the knapsack problem for wreath products is studied. It turns out that decidability of knapsack is not preserved under wreath product. On the other hand, the class of knapsack-semilinear groups, where solutions sets of knapsack equations are effectively semilinear, is closed under...

This paper shows the presence of high-affinity binding sites for melatonin in human circulating T lymphocytes, but not in B lymphocytes. The binding of melatonin to T cells was dependent on time, stable, reversible, saturable, specific, and inversely correlated to the production of melatonin, expressed as the nocturnal 12 h production of its urinary metabolite 6-sulfatoxymelatonin. The affinity...