With the great advances in ancient DNA extraction, genetic data are now obtained from geographically separated individuals from both present and past. However, population genetics theory about the joint effect of space and time has not been thoroughly studied. Based on the classical stepping-stone model, we develop the theory of Isolation by distance and time. We derive the correlation of allel...

In multiprocessor system Task scheduling is essential operation. The main objective of task scheduling is to shorten the length of schedule. The effectiveness by doing so is beneficial for large number of calculations having some constraints like time constraints etc. The proposed algorithm has the efficient execution of the schedule on parallel system that takes the structure of the applicatio...

Network based intrusions have become a serious threat to the users of the Internet. Intruders who wish to attack computers attached to the Internet frequently conceal their identity by staging their attacks through intermediate “stepping stones”. This makes tracing the source of the attack substantially more difficult, particularly if the attack traffic is encrypted. In this paper, we address t...

Mutualism is a major force driving evolution and sustaining ecosystems. Although the importance of spatial degrees of freedom and number fluctuations is well known, their effects on mutualism are not fully understood. With range expansions of microbes in mind, we show that, even when mutualism confers a selective advantage, it persists only in populations with high density and frequent migratio...

Is Temporary Agency Employment a Stepping Stone for Immigrants? We investigate whether agency employment is a bridge into regular employment for immigrants to Denmark using the timing-of-events approach. We provide evidence of large positive in-treatment effects, particularly for non-western immigrants and immigrants arriving during childhood. Post-treatment effects are fairly high for male non...

Z 2 in the limit L→∞, and study the time it takes two lineages tracing backward in time to coalesce. Our work fills a gap between the finite range migration case of [Ann. Appl. Probab. 15 (2005) 671–699] and the long range case of [Genetics 172 (2006) 701–708], where the migration range is a positive fraction of L. We obtain limit theorems for the intermediate case, and verify a conjecture in [...

Creating online communities of practice involves much more than creating software. Software houses online communities of practice activities but social interactions also depend on who is involved, what their goals are, their personalities and the community’s norms and policies. By paying attention to these sociability issues, community members can influence how their community develops. Norms t...

2.1 Summary This article provides a stepping-stone for the development of domain-independent design theory, based on a study initiated within the framework of the postgraduate Eindhoven design engineer program for Architectural Design Management Systems. This design theory is being developed to support the design of large-scale, complex design processes, such as one has in large building projec...

Vredenburgh and colleagues conducted the first phase II study of bevacizumab plus irinotecan in recurrent malignant glioma, confirming the safety and efficacy of bevacizumab. This study, which was published in the February 15, 2007, issue of Clinical Cancer Research, was a stepping stone for subsequent research, leading to regulatory approval of bevacizumab for recurrent glioblastoma. Clin Canc...