participation in clinical trials can be useful for the health of a person, in who it is conducted, but it does not have to be - it can even be harmful. therefore, primary motive to accept such risk is humanity and human wish to contribute to the progress of medicine; this is expressed by personal consent. the consent, however, can be an expression of personal humanity, and for this, it is not l...

We introduce two new notions for hypergraphs, hypertree-depth and minors in hypergraphs. We characterise hypergraphs of bounded hypertree-depth by the ultramonotone robber and marshals game, by vertex-hyperrankings and by centred hypercolourings. Furthermore, we show that minors in hypergraphs are ‘well-behaved’ with respect to hypertree-depth and other hypergraph invariants, such as generalise...

CONTEXT In 2005, Arkansas changed its parental notification requirement for minors seeking an abortion to a parental consent law, under which a minor can obtain an abortion without consent after obtaining a judicial waiver. METHODS Using state health department data on 7,463 abortions among 15-19-year-olds over the period 2001-2007, an analysis of abortion and second-trimester abortion rates ...

Although professional guidelines recommend against testing minors for adult-onset genetic conditions, the genetic testing of minors for BRCA1/2 alterations has been debated in the literature. To better understand the opinions of BRCA mutation carriers regarding the genetic testing of minors and the cognitive and affective processes underlying these opinions, we interviewed BRCA mutation carrier...

Graph minors and the theory of graphs embedded in surfaces are fundamentally interconnected. Robertson and Seymour used graph minors to prove a generalization of the Kuratowski Theorem to arbitrary surfaces [37], while they also need surface embeddings in their Excluded Minor Theorem [45]. Various recent results related to graph minors and graphs on surfaces are presented.

This paper characte rizes real symmetri c matri ces A s uch that all t X t princ ipal minors a re equal and a ll t X t nonprinc ipal minors a re of fixed sign, for two consecutive values of t less than rank A. It a lso cha rac te rizes matrices A (over an arbitrary fi eld ) in which a ll t X t principal minors are equal and all nonprin cipal t X t minors a re e qua l, for one fixed value of t l...

The classical Schur algorithm computes the LDL T factorization of a symmetric Toeplitz matrix in O(n 2) operations, but requires that all the principal minors of the matrix be nonsingular. Look-ahead schemes have been proposed to deal with matrices that have exactly singular principal minors 9], 11]. Unfortunately, these algorithms cannot be extended to matrices that have ill-conditioned princi...