We apply combinatorial arguments to establish structural constraints on Costas arrays. We prove restrictions on when a Costas array can contain a large corner region whose entries are all 0. In particular, we prove a 2010 conjecture due to Russo, Erickson and Beard. We then constrain the vectors joining pairs of 1s in a Costas array by establishing a series of results on its number of “mirror p...

In this paper we test two hypotheses regarding magical thinking about the perceived likelihood of future events. The first is that people believe that those who “tempt fate” by failing to take necessary precautions are more likely to suffer negative outcomes. The second is the “protection effect”, where reminding people of precautions they have taken leads them to see related risks as less like...

Formation of the coronary vessels is a fundamental event in heart development. Congenital abnormalities in the coronary system can have major deleterious effects on heart function. It is also possible that subtle variation in the patterning of coronary vessels has significant but uncharacterized effects on myocardial structure and function. In addition, generation of the coronary vascular syste...

The Social Construction of Disaster Disaster is widely perceived as an event beyond human control. The capricious hand of fate has moved against unsuspecting human communities, creating massive destruction and despair.[i] The sudden randomness of the event accentuates the cruelty of its effects, as surely the victims would have acted differently, had they known the risk. Other nations and organ...

Some of the signaling molecules required for formation of long-term memories are involved primarily in adult brain function, but others participate in a variety of other biological processes. The Notch signaling pathway, which is important for cell fate specification and differentiation in various systems, is also active in the mature brain. Here, we review evidence from recent studies indicati...

The process of cell fate determination has been depicted intuitively as cells travelling and resting on a rugged landscape, which has been probed by various theoretical studies. However, few studies have experimentally demonstrated how underlying gene regulatory networks shape the landscape and hence orchestrate cellular decision-making in the presence of both signal and noise. Here we tested d...

The Drosophila external sensory (es) organ is an excellent model system to study cell fate specification. Its development involves multiple steps of cell fate determination, which are governed by combined effects of intrinsic and extrinsic signals. Eventually, these signals are transduced to the nucleus and integrated to change the state of gene expression that promotes a particular fate (Jan a...

Stem cells have the capacity to differentiate into various lineages, and the ability to reliably direct stem cell fate determination would have tremendous potential for basic research and clinical therapy. Nanotopography provides a useful tool for guiding differentiation, as the features are more durable than surface chemistry and can be modified in size and shape to suit the desired applicatio...