Monotonicity and regularity of the speed for excited random walks in higher dimensions

We introduce a method for studying monotonicity of the speed of excited random walks in high dimensions, based on a formula for the speed obtained via cut-times and Girsanov's transform. While the method gives rise to similar results as have been or can be obtained via the expansion method of van der Hofstad and Holmes, it may be more palatable to a general probabilistic audience. We also revisit the law of large numbers for stationary cookie environments. In particular, we introduce a new notion of $e_1-$exchangeable cookie environment and prove the law of large numbers for this case.Comment: arXiv admin note: text overlap with arXiv:0705.0658 by other authors without attributio

Dynamic Multi-Arm Bandit Game Based Multi-Agents Spectrum Sharing Strategy Design

For a wireless avionics communication system, a Multi-arm bandit game is mathematically formulated, which includes channel states, strategies, and rewards. The simple case includes only two agents sharing the spectrum which is fully studied in terms of maximizing the cumulative reward over a finite time horizon. An Upper Confidence Bound (UCB) algorithm is used to achieve the optimal solutions for the stochastic Multi-Arm Bandit (MAB) problem. Also, the MAB problem can also be solved from the Markov game framework perspective. Meanwhile, Thompson Sampling (TS) is also used as benchmark to evaluate the proposed approach performance. Numerical results are also provided regarding minimizing the expectation of the regret and choosing the best parameter for the upper confidence bound

The key parameters that govern translation efficiency

Translation of mRNA into protein is a fundamental yet complex biological process with multiple factors that can potentially affect its efficiency. Here, we study a stochastic model describing the traffic flow of ribosomes along the mRNA (namely, the inhomogeneous $\ell$-TASEP), and identify the key parameters that govern the overall rate of protein synthesis, sensitivity to initiation rate changes, and efficiency of ribosome usage. By analyzing a continuum limit of the model, we obtain closed-form expressions for stationary currents and ribosomal densities, which agree well with Monte Carlo simulations. Furthermore, we completely characterize the phase transitions in the system, and by applying our theoretical results, we formulate design principles that detail how to tune the key parameters we identified to optimize translation efficiency. Using ribosome profiling data from S. cerevisiae, we shows that its translation system is generally consistent with these principles. Our theoretical results have implications for evolutionary biology, as well as synthetic biology.Comment: To appear in Cell Systems. 32 pages, 10 figures, 1 tabl

Modeling of Sediment Transport and Turbidity Maximum in the Gironde Estuaries (France) by Single- and Two-Phase Approaches

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Dynamic Interaction of USP14 with the Chaperone HSC70 Mediates Crosstalk between the Proteasome, ER Signaling, and Autophagy

USP14 is a deubiquitinating enzyme associated with the proteasome that is important for protein degradation. Here we show that upon proteasomal inhibition or expression of the mutant W58A38 USP14, association of USP14 with the 19S regulatory particle is disrupted. MS-based interactomics revealed an interaction of USP14 with the chaperone, HSC70 in neuroblastoma cells. Proteasome inhibition enhanced binding of USP14 to HSC70, but also to XBP1u and IRE1α proteins, demonstrating a role in the unfolded protein response. Striatal neurons expressing mutant huntingtin exhibited reduced USP14 and HSC70 levels, whilst inhibition of HSC70 downregulated USP14. Furthermore, proteasome inhibition or the use of mutant W58A-USP14 facilitated the interaction of USP14 with the autophagy protein, GABARAP. Functionally, overexpression of W58A-USP14 increased GABARAP positive autophagosomes in striatal neurons and this was abrogated using the HSC70 inhibitor, VER-155008. Modulation of the USP14-HSC70 axis by various drugs may represent a potential therapeutic target in HD to beneficially influence multiple proteostasis pathwaysPeer reviewe