A permutation π is said to be a Dumont permutation of the first kind if each even integer in π must be followed by a smaller integer, and each odd integer is either followed by a larger integer or is the last element of π (see, for example, www.theory.csc.uvic.ca/∼cos/inf/perm/Genocchi Info.html). In Duke Math. J. 41 (1974), 305–318, Dumont showed that certain classes of permutations on n lette...

Knockout mouse models targeting various cytochrome P450 (P450 or CYP) genes are valuable for determining P450’s biologic functions, including roles in drug metabolism and chemical toxicity. In this study, a novel Cyp2a(4/5)bgs-null mouse model was generated, in which a 1.2-megabase pair genomic fragment containing nine Cyp genes in mouse chromosome 7 (including, sequentially, Cyp2a5, 2g1, 2b19,...

We study generating functions for the number of permutations on n letters avoiding 132 and an arbitrary permutation τ on k letters, or containing τ exactly once. In several interesting cases the generating function depends only on k and is expressed via Chebyshev polynomials of the second kind. 2000 Mathematics Subject Classification: Primary 05A05, 05A15; Secondary 30B70, 42C05

A graphG = (V,E) is word-representable if there exists a word w over the alphabet V such that letters x and y alternate in w if and only if xy is an edge in E. Word-representable graphs are the main focus in “Words and Graphs” by Kitaev and Lozin. A word w = w1 · · ·wn avoids the pattern 132 if there are no 1 ≤ i1 < i2 < i3 ≤ n such that wi1 < wi3 < wi2. A recently suggested research direction ...

v < va. In the other extreme, when v ˆ 0:4 arcsec, the magnetic ®eld from the magnetar would be negligible, but the inferred ®eld strength can be easily explained as arising from compression of the ambient ®eld by the bow shock. The mean expansion speed of the nebula is 3:5 3 1010d5v4t 2 1 10 cm s 2 1 where t10 is the age of the nebula in units of 10 days. Thus in the limit of v ˆ 0:4 arcsec th...

We study generating functions for the number of involutions of length n avoiding (or containing exactly once) 132 and avoiding (or containing exactly once) an arbitrary permutation τ of length k. In several interesting cases these generating functions depend only on k and can be expressed via Chebyshev polynomials of the second kind. In particular, we show that involutions of length n avoiding ...

likely than nonusers to engage in risky sexual behavior and that they are less likely than nonusers to rely on condoms. In some studies, condom use has been treated as one component of a sexual-risk index, which is then related to substance use. In other research, condom use has been treated as a separate independent variable, which is then related to substance use directly. In this article, we...

The aim of this review is to examine two factors that may be associated with development of childhood overweight: early feeding, namely exclusive breastfeeding practices; family structure. Findings from the Identification and prevention of Dietaryand lifestyle-induced health EFfects In Children and infantS (IDEFICS) study are presented in the context of the literature. IDEFICS is a multi-centre...