Patchiness of habitat has important influences on distributions and abundances of organisms. Given the increasing threat of loss and alteration of habitats due to pressures associated with humans, there is a need for ecologists to understand species' requirements for habitat and to predict changes to taxa under various future environmental conditions. This study tested hypotheses about the gene...

Our essay begins with explication of the notion of eigenform as pioneered by Heinz von Foerster in his papers (Foerster, 1981, pp. 258–271, pp. 274–285, pp. 288–309) and explored in papers of the author (Kauffman, 2003, pp. 73–90, 2005, pp. 129–150; 2009, pp. 121–137, 2010, pp. 48–89). In Foerster (1981, pp. 274–285) the familiar objects of our existence can be seen as tokens for the behaviors ...

We study optimal double helices with straight axes (or the fattest tubes around them) computationally using three kinds of functionals; ideal ones using ropelength, best volume packing ones, and energy minimizers using two one-parameter families of interaction energies between two strands of types r−α and 1 r exp(−kr). We compare the numerical results with experimental data of DNA.

In this paper we consider new upscaling and homogenization methods for the pressure equation that are less sensitive to the boundary condition assumptions than many other published methods. We start from the discretized pressure equation and rely on the construction of subproblems with signii-cantly fewer unknowns, describing the behaviour of the solution of the ne-grid problem in suitable subs...