Using arithmetic conditions on affine semigroups we prove that for a simplicial toric variety of codimension 2 the property of being a set-theoretic complete intersection on binomials in characteristic p holds either for all primes p, or for no prime p, or for exactly one prime p.

As Bernard Nahlen of the Global Fund to fight AIDS, Tuberculosis and Malaria told the Bulletin: “In children in higheendemic areas, indirect, malariae related mortality may be just as or even more important than the burden of acute, direct malariaeattributable more tality — but it is even more difficult to measure.” To further clarify the picture, WHO recommends that specific, direct, acute mal...

Braids ñàï Üå represented as two-dimenSional diagrams showing the crossings of strings or as words over the generators of à braid group. À minimal braid is îïå with the fewest crossings (or the shortest words) among all possible repre~entations topologically equivalent to that braid. ÒÜå main result of this paper is that the set of minimal braids is co-NP-complete. Algorithmic problems in braid...

An irreversible k-threshold process is a process on a graph where vertices change color from white to black if they have at least k black neighbors. An irreversible k-conversion set is a subset S of vertices of a graph G such that the irreversible k-threshold process changes all vertices of G to black if S is the initial set of black vertices. We show that deciding the existence of an irreversi...

We previously isolated a complete set of primary trisomics along with many other aneuploids from triploid plants derived from an indica rice variety "Zhongxian 3037." About 30,000 progeny from these trisomic and aneuploid plants were grown each year from 1994 to 1999. The variants that differed morphologically from both the diploids and the original primary trisomics were collected for cytologi...

In this paper, a necessary and sufficient condition on which a set of implications is complete is proposed with the help of the notion of model from logic. Besides, using the closure of an attribute subset to a set of implications, we present a formal method to remove the redundant implications from a complete set. Subsequently, we provide an algorithm to generate a complete set of implications...

In this paper, we take the advantages of extended superquadrics to represent and recognize the entire set of 36 geons. Extended superquadrics are novel volumetric shape models that include superquadrics as a special case. An extended superquadric model can be deformed in any direction because it extends the exponents of the superquadric model from constants to functions of the latitude and long...

The Feedback Arc Set problem asks whether it is possible to delete at most k arcs to make a directed graph acyclic. We show that Feedback Arc Set is NPcomplete for bipartite tournaments, that is, directed graphs that are orientations of complete bipartite graphs.

Population scale studies combining genetic information with molecular phenotypes (for example, gene expression) have become a standard to dissect the effects of genetic variants onto organismal phenotypes. These kinds of data sets require powerful, fast and versatile methods able to discover molecular Quantitative Trait Loci (molQTL). Here we propose such a solution, QTLtools, a modular framewo...

Rewriting is a common functionality in proof assistants, that allows to simplify theorems and goals. The set of equations to use in a rewrite step has to be manually specified, and therefore often includes rules which may lead to non-termination. Even in the case of termination another desirable property of a simplification set would be confluence. A well-known technique from rewriting to trans...