Contents Combinatorial Convexity by Víctor Álvarez and Jeong

Nail-patella syndrome. A case with a de novo mutation in the LMX1B gene not previously described.

Correspondence: Naira Álvarez Martín Sección de Nefrología Pediátrica. Servicio de Pediatría. Hospital Nuestra Señora de la Candelaria. Ctra. General del Rosario s/n. 38010 Santa Cruz de Tenerife. (Spain) [email protected] [email protected] Nail-patella syndrome. A case with a de novo mutation in the LMX1B gene not previously described Naira Álvarez-Martín, María J. Gamundi, Imma Hernan,...

On the log-convexity of combinatorial sequences

Here presented is a survey for the log-convexity of some famous combinatorial sequences. We develop techniques for dealing with the log-convexity of sequences satisfying a three-term recurrence. We also introduce the concept of q-log-convexity and establish the link with linear transformations preserving the log-convexity. MSC: 05A20; 11B73; 11B83; 11B37

A Criterion for the Log-Convexity of Combinatorial Sequences

Recently, Došlić, and Liu and Wang developed techniques for dealing with the log-convexity of sequences. In this paper, we present a criterion for the log-convexity of some combinatorial sequences. In order to prove the log-convexity of a sequence satisfying a three-term recurrence, by our method, it suffices to compute a constant number of terms at the beginning of the sequence. For example, i...

The allocative efficiency measure by means of a distance function: The case of Spanish public railways

Substitutes and complements in network flows viewed as discrete convexity

A new light is shed on “substitutes and complements” in the maximum weight circulation problem with reference to the concepts of L-convexity and M-convexity in the theory of discrete convex analysis. This provides us with a deeper understanding of the relationship between convexity and submodularity in combinatorial optimization.