Available data on the isotopic ratio See PDF for Equation of ammonia (r(a)) and that of urea (r(u)) after a single feeding of glycine, aspartic acid, and ammonium citrate are analyzed. From this analysis the following conclusions are drawn. 1. The isotopic ratio See PDF for Equation of ammonia (r(a)) is always higher than that of urea (r(u)) in the initial period after a single feeding of isoto...

Ab initio molecular dynamics simulated annealing technique coupled with density functional theory in the local density approximation implemented in Spanish initiative for electronic simulations with thousands of atoms method is employed to search the ground state geometries of silicon clusters containing 10–16 atoms. We found a number of new isomers which are not previously reported. The atoms ...

A new notion of commutator was defined in any variety of Ω-groups A, relative to any fixed subvariety B of A [1]. This notion gives back the usual commutator of normal subgroups when A is the variety of groups and B the subvariety of abelian groups (see Section 2), but also the Peiffer commutator of normal precrossed submodules, when A is the variety of precrossed modules and B the subvariety o...

Allelic variants at the catechol-O-methyltransferase (COMT) locus are candidates to contribute to genetic components of interindividual differences in vulnerability to substance abuse. COMT plays a prominent role in dopaminergic circuits important for drug reward, and COMT alleles encode enzymes whose activities vary from three- to four-fold. We compared COMT allele frequencies in control resea...

Let p be an odd prime. We first get some non-existence and structural results on (pn,p,pn,n) relative difference sets with gcd(p,n)= 1 through a group ring approach. We then give a construction of (p(p+ 1),p,p(p+ 1),p+ 1) relative difference sets with p a Mersenne prime.

We introduce, for every integer n ≥ 1, the notion of an n-relative category and show that the category of the small n-relative categories is a model for the homotopy theory of n-fold homotopy theories, i.e. homotopy theories of . . . of homotopy theories. 1. Background and motivation In this introduction we • recall some results of (higher) homotopy theory, and • explain how they led to the cur...