the center (periphery) of a graph is the set of vertices with minimum (maximum)eccentricity. in this paper, the structure of centers and peripheries of some classes ofcomposite graphs are determined. the relations between eccentricity, radius and diameterof such composite graphs are also investigated. as an application we determinethe center and periphery of some chemical graphs such as nanotor...

The center (periphery) of a graph is the set of vertices with minimum (maximum) eccentricity. In this paper, the structure of centers and peripheries of some classes of composite graphs are determined. The relations between eccentricity, radius and diameter of such composite graphs are also investigated. As an application we determine the center and periphery of some chemical graphs such as nan...

It has been shown that the hyperpolarization-activated current “if” that is blocked by 2 mM Cs+ plays a minor role on pacemaker activity of the center and a major role on activity of the periphery of rabbit intact sino-atrial node. On the other hand some investigations showed that if the atrial muscle, surrounding the sino-atrial node, is cut away there is a shift in leading pacemaker site from...

Noam Chomsky argues that only a meager percentage of the world, consisting of mainly large corporations and developed nations, prosper from globalization. As stated in Immanuel Wallerstein’s World-System Theory, the modern system of the world, which is constructed according to the economic status of nations, can be divided into three levels: the core, the semi-periphery, and the periphery. Whil...

The localization of genes within the nuclear space is of paramount importance for proper genome functions. However, very little is known on the cis-acting elements determining subnuclear positioning of chromosome segments. We show here that the D4Z4 human subtelomeric repeat localizes a telomere at the nuclear periphery. This perinuclear activity lies within an 80 bp sequence included within a ...

Wind affects adversely the cooling tower thermal performance. A field investigation was carried out to study the thermal performance of Heller cooling towers under wind conditions, involving measurement of wind velocity and its direction around the cooling tower, and obtaining water flow rates and temperatures at the cooling tower inlet and outlet. Results show that air suction at the tower top...

Processes of social opinion formation might be dominated by a set of highly influential agents acting as ‘opinion leaders’. Here we explore whether such a perspective could shed light on the dynamics of a well known economic sentiment index. To this end, we hypothesize that the respondents of the survey under investigation form a core-periphery network, and we identify those agents that define ...