Characterization of special hamiltonian graphs

We get a formula for the number of hamiltonian circuits of a graph through which we characterize the special hamiltonian graphs, that is containing a dominant circuit of minimal length.     

Multiscale models for biological systems

Life, amazingly rich in diversity of shapes and functions, explores the limits of extreme complexity in nature. In this review we shall discuss in general terms the use of multiscale mathematical and computer models to study the dynamics of biological systems. These models permit integration of the rapidly expanding knowledge concerning the molecular basis of biology and its complex, nonlinear relationship with the emerging shapes and functions of cells, tissues and organs in living organisms.     

Quantum Machine and Semantic Realism Approach: a Unified Model

The Geneva–Brussels approach to quantum mechanics (QM) and the semantic realism (SR) nonstandard interpretation of QM exhibit some common features and some deep conceptual differences. We discuss in this paper two elementary models provided in the two approaches as intuitive supports to general reasonings and as a proof of consistency of general assumptions, and show that Aerts’ quantum machine can be embodied into a macroscopic version of the microscopic SR model, overcoming the seeming incompatibility between the two models. This result provides some hints for the construction of a unified perspective in which the two approaches can be properly placed.     

Bowen-Franks groups of reducible bimodal subshifts of finite type

We study the Bowen-Franks groups of subshifts of finite type associated with reducible bimodal periodic kneading sequences pairs.     

Antiferromagnetic TiFe2 in applied fields: experiment and simulation

Mössbauer spectra of a powdered TiFe₂ sample were measured under different applied fields and the results were compared to simulated spectra obtained by minimizing the total energy of a two-sublattice antiferromagnet. In order to reproduce experimental results a highly textured distribution had to be assumed, the local anisotropy axis lying mostly perpendicular to the applied field. Thus, magnetic alignment of AF grains by an external field was demonstrated. In addition, exchange and anisotropy fields for TiFe₂ at T?～?0 K have been determined.     

Two-loop vertices in quantum field theory: infrared convergent scalar configurations

A comprehensive study is performed of general massive, scalar, two-loop Feynman diagrams with three external legs. Algorithms for their numerical evaluation are introduced and discussed, numerical results are shown for all different topologies and comparisons with analytical results, whenever available, are performed. An internal cross-check, based on alternative procedures, is also applied. The analysis of infrared divergent configurations, as well as the treatment of tensor integrals, will be discussed in two forthcoming papers.     

Chemo-enzymatic preparation from renewable resources of enantiopure 1,3-oxazolidine-2-thiones

Chiral 1,3-oxazolidine-2-thiones were prepared in enantiopure form from renewable resources through an enzymatic process involving immobilized myrosinase (thioglucoside glucohydrolase E.C. 3.2.3.1).     

New heuristics for the maximum diversity problem

The maximum diversity problem (MDP) consists of identifying, in a population, a subset of elements, characterized by a set of attributes, that present the most diverse characteristics among the elements of the subset. The identification of such solution is an NP-hard problem. Some heuristics are available to obtain approximate solutions for this problem. In this paper, we propose different GRASP heuristics for the MDP, using distinct construction procedures and including a path-relinking technique. Performance comparison among related work and the proposed heuristics is provided. Experimental results show that the new GRASP heuristics are quite robust and are able to find high-quality solutions in reasonable computational times. G.C. Silva’s work sponsored by CAPES MSc scholarship. L.S. Ochi’s work sponsored by CNPq research grants 304103/2003-9 and 550059/2005-9. S.L. Martins’s work sponsored by CNPq research grant 475124/03-0. A. Plastino’s work sponsored by CNPq research grants 300879/00-8 and 475124/03-0.