INTRODUCTION The use of reciprocating movement was claimed to increase the resistance of nickel-titanium (NiTi) file to fatigue in comparison with continuous rotation. Recently 2 new brands of NiTi files have been marketed for use in a RM mode. The purpose of this study was to compare the cyclic fatigue resistance and torsional resistance of these 2 files, Reciproc and WaveOne. METHODS Cyclic...

This paper describes surface characteristics, in terms of its morphology, roughness and near-surface damage of Si wafers cut by diamond wire sawing (DWS) of Si ingots under different cutting conditions. Diamond wire sawn Si wafers exhibit nearly-periodic surface features of different spatial wavelengths, which correspond to kinematics of various movements during wafering, such as ingot feed, wi...

In this paper I describe how the spatial dynamics of autocatalytic interactions among entities in a virtual world led to a type of co-operation that typically would be studied from a game theoretical perspective. The entities were very simple and completely identical at the start of the simulation. They just aggregated and performed aggressive interactions in which winning was self-reinforcing....

In many studies on social demeanour it is overlooked how complex social behaviour may result from simple self-reinforcing interactions between entities. In this paper an individualoriented computer model is used to study whether the spatial dynamics between artificial agents and their autocatalytic interactions may result in a rank-related differentiation of social-activity profiles and ‘repaym...

Knowledge of the principles by which behavioral sequences are generated is essential to progress in our understanding of neural mechanisms. We describe here a set of natural principles or syntax rules that organize the components of grooming and feeding. The behavioral stream of facial grooming or of taste-elicited ingestive/aversive consummatory actions of rats can be viewed as a long series o...

Individual acts of cooperation give rise to dynamic social networks. Traditionally, models for cooperation in structured populations are based on a separation of individual strategies and of population structure. Individuals adopt a strategy-typically cooperation or defection, which determines their behaviour toward their neighbours as defined by an interaction network. Here, we report a behavi...

In contrast to guilt based reciprocity, which hypothesizes that reciprocity is an increasing function of the 2 order expectation of trustor’s expectation for reciprocation, we test for reciprocity which is a decreasing function of trustees 2 order expectations, i.e., that people can reciprocate out of gratitude. To unambiguously decrease 2 order expectations in our treatment, we broke up a stan...

We study the detailed growth of a social networking site with full temporal information by examining the creation process of each friendship relation that can collectively lead to the macroscopic properties of the network. We first study the reciprocal behavior of users, and find that link requests are quickly responded to and that the distribution of reciprocation intervals decays in an expone...