Nongenetic perturbations, such as environmental change or developmental noise, can induce novel phenotypes. If an induced phenotype appears recurrently and confers a fitness advantage, selection may promote its genetic stabilization. Nongenetic perturbations can thus initiate evolutionary innovation. Genetic variation that is not usually phenotypically visible may play an important role in this...

Zirconia-nickel functionally graded materials were obtained by powder metallurgy technique. The microstructure, residual stress, fracture toughness and Vickers hardness were investigated. Mixed-mode fracture response of YSZ /Ni functionally graded materials was examined utilizing the three point bending test and finite element method (Cosmos/M 2.7). The results show that the stress intensity fac...

In nematodes, environmental or physiological perturbations alter death's scaling of time. In human cancer, genetic perturbations alter death's curvature of time. Those changes in scale and curvature follow the constraining contours of death's invariant geometry. I show that the constraints arise from a fundamental extension to the theories of randomness, invariance and scale. A generalized Gomp...

Starting with fewer degrees of freedom has been shown to enable a more efficient exploration of the sensorimotor space. While not necessarily leading to optimal task performance, it results in a smaller number of directions of stability, which guide the coordination of additional degrees of freedom. The developmental release of additional degrees of freedom is then expected to allow for optimal...

The Cenomanian-Turonian Gharesu section in the east of Kopet-Dagh basin have been investigated to determine the relationship between palaeoenvironmental perturbations and nitrogen cycling across OAE2. This succession is composed of 43 m shale and marl interbedded with glauconitic sandstone and lies between Aitamir-Abderaz formations boundary. The nitrogen Isotope values fluctuate between 0‰ to ...

this paper presents some analyses about the robust practical stability of a class of nonlinear affine systems in the presence of non-vanishing perturbations based on the passivity concept. the given analyses confirm the robust passivity property of the perturbed nonlinear systems in a certain region. moreover, robust control laws are designed to guarantee the practical stability of the perturbe...

Abstract Groups of animals can perform highly coordinated collective behaviours that confer benefits to the participating individuals by facilitating social information exchange and protection from predators 1 . Some these characteristics could arise when groups operate at critical points between two structurally functionally different states, leading maximal responsiveness external stimuli eff...