In a striking case of pathogen transfer involving the bacterium responsible for human acne, Propionibacterium acnes, Campisano et al. (2014) report on a new type of P. acnes that exploits grapevines, dubbing it P. acnes-type Zappae. They named the bacterium after the Italian term “zappa,” meaning hoe, as well as a tribute to eclectic composer Frank Zappa, who once wrote of “sand-blasted zits” i...

Expressions involving the product of the permanent with the (n − 1)st power of the determinant of a matrix of indeterminates, and of (0,1)-matrices, are shown to be related to an extension to odd dimensions of the Alon-Tarsi Latin Square Conjecture, first stated by Zappa. These yield an alternative proof of a theorem of Drisko, stating that the extended conjecture holds for Latin squares of odd...

Introduction. By a lattice homorphism of a group G onto a group G' we mean a single-valued mapping of the lattice L(G) of subgroups of G onto the lattice L(G') of subgroups of G', which preserves all unions and intersections, that is, which is subject to the conditions 1. (U,S,)0 = U,(S¿), 2. (r\vSr) = Ç)ASd>), for every (finite or infinite) set of subgroups 5„ of G. We call proper any l...