Gradients in industrial bioreactors have attracted substantial research attention since exposure to fluctuating environmental conditions has been shown lead changes the metabolome, transcriptome as well population heterogeneity industrially relevant microorganisms. Such also found impact key process parameters like yield on substrate and productivity. Hence, understanding gradients is important...

We have computed a set of multiphase chemical evolution models in which the radial mass distribution of each theoretical galaxy is calculated using the universal rotation curve from Persic, Salucci & Steel (1996). We obtain the chemical evolution for galaxies of different masses and morphological types by changing the efficiencies to form molecular clouds and stars according with these types. W...

The initial activity-independent formation of a topographic map in the retinotectal system has long been thought to rely on the matching of molecular cues expressed in gradients in the retina and the tectum. However, direct experimental evidence for the existence of such gradients has only emerged in the past two years. The new data has provoked the discussion of a new set of models in the expe...

We propose a new way of deriving policy gradient updates for reinforcement learning. Our technique, based on Fourier analysis, recasts integrals that arise with expected policy gradients as convolutions and turns them into multiplications. The obtained analytical solutions allow us to capture the low variance benefits of EPG in a broad range of settings. For the critic, we treat trigonometric a...

Shh activity and at different distances from the source. The proper functioning of tissues and organs requires These observations provide unequivocal evidence that that each cell differentiate appropriately for its position. Shh acts directly on distant cells and therefore that Shh In many cases, the positional information that instructs forms a morphogen gradient in the developing neural cells...

DIFFERENCES IN MEASURED RATES OF SPECIation and extinction among living species are commonly used to explain latitudinal diversity gradients. The logic is straightforward: the higher the net diversification rate (the difference between the speciation and extinction rate), the greater the number of species. In this vein, J. T. Weir and D. Schluter conclude from their recent study of birds and ma...

Optical observations of a statistically complete sample of edge-on disc-dominated galaxies are used to study the intrinsic vertical colour gradients in the galactic discs, in order to constrain the effects of population gradients, residual dust extinction and gradients in the galaxies’ metal abundance. For the majority of our sample galaxies, the colours and colour gradients in the range 1.0hz ...