Interplay of cellular states: Role of delay as control mechanism

Delay is everywhere, no matter how small or big it is. Experimental evidences show the existence and importance of time delayed reactions specially in biological systems. The role of delay is found to be multifunctional and is seemed to be system dependent. The analytically solved P(X,t) of gene regulatory process shows universal class of Poisson process at stationary condition. However, time delay creates a possible condition to the system to impart correlation in the stochastic process as sub-Poissonian or noise enhancement process which could be important in regulating and controlling the system. The results of simulation of few biological systems (gene regulation, circadian rhythm, and repressilator) using delay stochastic simulation algorithm show the possibilities of delay induced onset of oscillating states, which could be the active states of the systems, where, the system can establish coherence among the system variables, enhance the signal processing, optimize the system activities, etc. On the other hand, delay can also induce switching off of the oscillating states, which may correspond to inactive state or system failure.

German Critical Philosophy and Marx

In this chapter, Robinson explores the German intellectuals who form the basis of Marxism. He links the history of German pietism and the Church with the development of Kantian materialism, which advocated for a radical reformulation of the German social order. Robinson then demonstrates how Kantian German idealism set in motion in German thought a series of determinations essential for Marx’s philosophy. While Marx is applauded for positing a revolutionary theory from the less radical ideas of Hegel, Robinson instead suggests that Hegel in fact contributed far more directly to Marxism than Marx admitted. Indeed, Robinson demonstrates how Hegel’s conception of a universal class (to be Marx’s proletariat), secularization of history (making history happen), and privileging of Western civilization as the only society based on Reason (the secularization of social change) all made their way into Marxism, notwithstanding Marx’s dismissal of Hegel as a mystical idealist. Robinson historicizes Marxism by demonstrating how Kant’s formulation of the German bureaucracy as a class, followed by Hegel’s argument that this class’s consciousness came from its political work, were appropriated by Marx and Engels for their later work.

The cup product of Brooks quasimorphisms

We prove the vanishing of the cup product of the bounded cohomology classes associated to any two Brooks quasimorphisms on the free group. This is a consequence of the vanishing of the square of a universal class for tree automorphism groups.

Beyond the Class–Race Binary

In his insightful new book, the historian David Roediger raises critical questions for scholar-activists seeking to understand white racism and contemporary capitalism and its class realities. He joins a long line of thinkers who have clearly recognized the need for both specifically racial and more universal, class-oriented programs of major social and economic change.

On the magnetorotational instability and elastic buckling

This paper demonstrates an equivalence between rotating magnetized shear flows and a stressed elastic beam. This results from finding the same form of dynamical equations after an asymptotic reduction of the axis-symmetric magnetorotational instability (MRI) under the assumption of almost-critical driving. The analysis considers the MRI dynamics in a non-dissipative near-equilibrium regime. Both the magnetic and elastic systems reduce to a simple one-dimensional wave equation with a non-local nonlinear feedback. Under transformation, the equation comprises a large number of mean-field interacting Duffing oscillators. This system was the first proven example of a strange attractor in a partial differential equation. Finding the same reduced equation in two natural applications suggests the model might result from other applications and could fall into a universal class based on symmetry.