Abstract Obesity is a major risk factor for type 2 diabetes mellitus development and is characterized by an abnormal expansion of adipose tissue and low-grade chronic inflammation that contribute to insulin resistance. Although there are multiple treatments, most therapies can produce undesirable side effects and therefore, new and effective treatments with fewer side effects are necessary. Previously, we demonstrated that a natural extract from the leaves of Eucalyptus tereticornis (OBE100) has anti-inflammatory, hypoglycemic and hypolipidemic activities. The major compounds identified in OBE100 were three pentacyclic triterpenoids, ursolic acid, oleanolic acid, and ursolic acid lactone. Triterpenoids have shown multiples biological activities. This current study compared the biological effect produced by OBE100 with five different reconstituted mixtures of these triterpenoids. Different cell lines were used to evaluate cytotoxicity, reactive oxygen species production, inflammatory cytokine expression, glucose uptake induction, leptin and adiponectin expression, and lipid accumulation. OBE100 treatment was the most efficacious and none of the formulated triterpenoid mixtures significantly improved on this. Moreover, OBE100 was less toxic and reduced reactive oxygen species production. Our study showed that the proven beneficial properties of triterpenoids may be enhanced due to the interaction with minor secondary metabolites present in the natural extract improving their anti-inflammatory properties.

Resumen: El objetivo de este trabajo es presentar un modelo concreto de poblaciones de especies en competición que exhibe la bifurcación Zip. La bifurcación zip fue introducida por Farkas en 1984 para un sistema tridimensional de ecuaciones diferenciales ordinarias que describe un quimiostato. Estudiaremos un sistema tridimensional de ecuaciones diferenciales ordinarias que modela la competición de dos poblaciones distintas de predadores por una única población presa. El sistema usa funciones trigonométricas concretas para representar la tasa de crecimiento de la presa y la respuesta funcional del predador. El modelo exhibe diferentes clases de comportamientos y muestra ejemplos de los llamados principio de exclusión competitiva y la competición

Abstract: The purpose of this paper is to present a concrete model of competing population species that exhibits a phenomenon called zip bifurcation. The Zip Bifurcation was introduced by Farkas in 1984 for a three dimensional ODE prey-predator system describing a chemostat. We will study a three dimensional system of ordinary differential equations that model the competition of two predators species for one single prey species. The system is based on concrete trigonometric functions modeling the growth rate of the prey and the functional response of the predator. The model exhibits different kinds of behavior and shows examples of the so called “competitive exclusión principle,” and the competition of one “r-strategist” and one “K-strategist.” Additionally, in order to illustrate the zip bifurcation, we will present some numerical simulations for our model.

Resumen En este artículo analizamos la noción de objeto matemático que tenían en la antigüedad clásica griega Platón y Aristóteles. En particular tratamos de probar que es erróneo interpretar la doble connotación que dicha noción exhibe en el pensamiento de Platón como expresión de una escisión ontológica que define dos tipos distintos de ‘objetos matemáticos’: los sensibles y los inteligibles. En el artículo defendemos que tal escisión es solo aparente puesto que en realidad lo que Platón introduce es una distinción entre dos maneras distintas de relacionarse con los objetos matemáticos: la de los Filósofos y la de los no Filósofos. Mostramos además que nuestra interpretación permite aclarar las ambigüedades en torno al concepto μоνάς, y disolver la tensión entre la existencia de dos disciplinas aparentemente distintas dedicadas al estudio de los objetos matemáticos discretos, la λоγιστική y la ἀριθμητική.

Abstract In this paper we study the concept of mathematical object as it was understood by ancient mathematical thought, particularly by Plato and Aristotle. We are going to prove that it is not right to interpret the duality of this concept in Plato’s works as consequence of an ontological division between two kinds of mathematical objects, i.e. the sensitive and the intelligible ones. We want to prove that such a division is not a real one because, as a matter of fact, Plato is proposing a differentiation between two possible ways to be related with mathematical objects: the way of the philosophers and the way of the non-philosophers. Moreover, we show that our interpretation is able to clarify the ambiguity around the concept of μоνάς and therefore eliminate the false distinction between the two subject matters devoted to the study of discrete mathematical objects: the λоγιστική and the ἀριθμητική.