Constraints on constraints: Surveying the epigenetic landscape

Constraints on Constraints: Surveying the Epigenetic Landscape

It is now relatively commonplace to advocate the need for some sorts of constraints on leornlng ond knowledge acquisition. The critical issues to cognitive science concern the sorts of constraints thot ore able to best model various phenomena of learning and development. Four types of constraints on learning ore proposed to be used as an interpretative fromework within which to: 1. Better under...

Freedom and Constraints in the K3 Landscape

We consider “magnetized brane” compactifications of the type I/heterotic string on K3 with U(1) background fluxes. The gauge group and matter content of the resulting six-dimensional vacua are parameterized by a matrix encoding a lattice contained within the even, self-dual lattice Γ3,19. Mathematical results of Nikulin on lattice embeddings make possible a simple classification of all such sol...

Empirical Constraints on Vacuum Decay in the Stringy Landscape

It is generally considered as self evident that the lifetime of our vacuum in the landscape of string theory cannot be much shorter than the current age of the universe. Here I show why this lower limit is invalid. A certain type of " parallel universes " is a necessary consequence of the string-landscape dynamics and might well allow us to " survive " vacuum decay. As a consequence our stringy...

Practical Constraints on Collaterals under Iranian Law

Local and Landscape Constraints on Coffee Leafhopper (Hemiptera: Cicadellidae) Diversity

The intensification of agriculture drives many ecological and environmental consequences including impacts on crop pest populations and communities. These changes are manifested at multiple scales including small-scale management practices and changes to the composition of land-use types in the surrounding landscape. In this study, we sought to examine the influence of local and landscape-scale...