In this paper, the existence of limit cycles for the specific bilinear systems is explored. Based on the BellmanGronwall inequality approach, not only the exponentially stable limit cycles phenomenon of such systems can be certified but also the oscillation behaviors of such systems can be correctly predicted. Finally, a numerical example is provided to illustrate the feasibility and effectiven...

The stability of outcomes under democratic decision-making is a significant issue in public choice. Several factors might make U.N. voting blocs less stable than blocs in national legislatures. Nevertheless, the data suggest that from 1946 to 1973 United Nations voting blocs were relatively stable. Nations that leave their blocs tend to vote with nearby blocs rather than making large ideologica...

In this paper we consider the bifurcations that occur at the trivial equilibrium of a general class of nonlinear Leslie matrix models for the dynamics of a structured population in which only the oldest class is reproductive. Using the inherent net reproductive number n as a parameter, we show that a global branch of positive equilibria bifurcates from the trivial equilibrium at n = 1 despite t...

BACKGROUND Vatalanib is an orally active, small molecule tyrosine kinase inhibitor of vascular endothelial growth factor receptor (VEGFR). Bevacizumab is also an angiogenesis inhibitor, but it possesses a different mechanism of action. This phase I study was conducted to determine the dose-limiting toxicity, maximum-tolerated doses, and recommended phase II doses of the combination of vatalanib...

We propose a new semi-implicit level set approach to a class of curvature dependent flows. The method generalizes a recent algorithm proposed for the motion by mean curvature where the interface is updated by solving the Rudin-Osher-Fatemi (ROF) model for image regularization. Our proposal is general enough so that one can easily extend and apply the method to other curvature dependent motions....

the paper deals with the analysis of the external factor (solar activity, volcanic eruptions) influence on tree growth at the kola peninsula, northwestern russia. pinus sylvestris l. (scots pine) tree-ring chronologies collected nearby the northern timberline (68.63n, 33.25e) include the oldest (1445-2005 ad) living pine tree found up to date in the kola peninsula. a total of 18 living trees p...

AIMS AND BACKGROUND Capecitabine is the reference treatment for anthracycline- and/or taxane-pretreated metastatic breast cancer (MBC). This study examined its efficacy, tolerability and impact on the quality of life of elderly patients with MBC. MATERIALS AND METHODS Between January 2002 and December 2009, 75 consecutive elderly patients with MBC received first-line chemotherapy with capecit...

Seasonal frozen loess tunnel stability is controlled by many factors. To study the effects of water content and freeze-thaw cycles of loess tunnel stability, taking loess in Shanxi Yangqu No. 1 tunnel face as the research object, to do different moisture stability studies on loess tunnel after repeated freeze-thaw cycles. The results show that: (1) by the comprehensive structure potential and s...

Robust attracting heteroclinic cycles have been found in many models of dynamics with symmetries. In all previous examples, robust heteroclinic cycles appear between a number of symmetry broken equilibria. In this paper we examine the first example where there are robust attracting heteroclinic cycles that include the origin, ie a point with maximal symmetry. The example we study is for vector ...

A system of difference equations that arises in population dynamics is studied. Criteria are given for the existence of equilibria lying in the positive cone and for the existence of periodic cycles lying on the boundary of the cone. These equilibria and cycles arise from a bifurcation that occurs as a fundamental parameter R0 increases through the value 1. Under monotone conditions on the nonl...