Omnipresent Maxwell’s demons orchestrate information management in living cells

The development of synthetic biology calls for accurate understanding of the critical functions that allow construction and operation of a living cell. Besides coding for ubiquitous structures, minimal genomes encode a wealth of functions that dissipate energy in an unanticipated way. Analysis of these functions shows that they are meant to manage information under conditions when discrimination of substrates in a noisy background is preferred over a simple recognition process. We show here that many of these functions, including transporters and the ribosome construction machinery, behave as would behave a material implementation of the informationmanaging agent theorized by Maxwell almost 150 years ago and commonly known as Maxwell’s demon (MxD). A core gene set encoding these functions belongs to the minimal genome required to allow the construction of an autonomous cell. These MxDs allow the cell to perform computations in an energy-efficient way that is vastly better than our contemporary computers

Expanding graphs, Ramanujan graphs, and 1-factor perturbations

We construct (k+-1)-regular graphs which provide sequences of expanders by adding or substracting appropriate 1-factors from given sequences of k-regular graphs. We compute numerical examples in a few cases for which the given sequences are from the work of Lubotzky, Phillips, and Sarnak (with k-1 the order of a finite field). If k+1 = 7, our construction results in a sequence of 7-regular expanders with all spectral gaps at least about 1.52

A Spatial Look at Negative Externalities in Agricultural Landscapes: Seedless Mandarins and Honey Bee Pollination in California

When honey bees transport pollen across citrus orchards they can increase the number of seeds in varieties that remain seedless otherwise. An increase in seeds diminishes the market value of the fruit creating an externality between seedless growers and beekeepers. This paper investigates the efficiency of different policy resolution of this externality including a range of regulated spatial segregations of beekeeping and seedless farming with or without financial compensations. We develop a spatial model of honey foraging behavior to quantify the efficiencies and redistributions of different policies that may be used to correct this market failure. Some of these policies have been implemented others are being currently discussed in policy debates in the California citrus belt. This paper illustrates that quantifying biophysical processes that create externalities is a necessary step towards evaluating the economics efficiency of alternative solutions.Resource /Energy Economics and Policy,

The future of the Belgian Press

Overview of the Belgian print media landscape with comarative approach for Flanders and Walloni

Entanglement in a fermion chain under continuous monitoring

We study the entanglement entropy of the quantum trajectories of a free fermion chain under continuous monitoring of local occupation numbers. We propose a simple theory for entanglement entropy evolution from disentangled and highly excited initial states. It is based on generalized hydrodynamics and the quasi-particle pair approach to entanglement in integrable systems. We test several quantitative predictions of the theory against extensive numerics and find good agreement. In particular, the volume law entanglement is destroyed by the presence of arbitrarily weak measurement.Comment: 18 pages, 8 figures, 2 new figure

Gravitational wave energy spectrum of hyperbolic encounters

The emission of gravitational waves is studied for a system of massive objects interacting on hyperbolic orbits within the quadrupole approximation following the work of Capozziello et al. Here we focus on the derivation of an analytic formula for the energy spectrum of the emitted waves. We checked numerically that our formula is in agreement with the two limiting cases for which results were already available: for the eccentricity {\epsilon} = 1, the parabolic case whose spectrum was computed by Berry and Gair, and the large {\epsilon} limit with the formula given by Turner.Comment: 9 pages, 4 figures, Accepted for publication in Physical Review