Complexity-entropy analysis at different levels of organization in written language

Written language is complex. A written text can be considered an attempt to convey a meaningful message which ends up being constrained by language rules, context dependence and highly redundant in its use of resources. Despite all these constraints, unpredictability is an essential element of natural language. Here we present the use of entropic measures to assert the balance between predictability and surprise in written text. In short, it is possible to measure innovation and context preservation in a document. It is shown that this can also be done at the different levels of organization of a text. The type of analysis presented is reasonably general, and can also be used to analyze the same balance in other complex messages such as DNA, where a hierarchy of organizational levels are known to exist

Charles M. Breder, Jr.: Palmetto Key, 1942

Charles M. Breder and his wife Ethel spent part of the summer of 1942 at the Palmetto Key field station, known today as Cabbage Key, on the west coast of Florida south of Charlotte Harbor. The Palmetto Key field station began in 1938 and ended in 1942 because of World War II. His Palmetto Key diary ran for 95 pages of notes, tables, diagrams, drawings, lists, and business records and this report presents a variety of fascinating entries. Diaries from other years all bear Breder's style of discipline, curiosity, humor, and speculations on nature. The diary was transcribed as part of the Coastal Estuarine Data/Document Rescue and Archeology effort for South Florida. (PDF contaons 24 pages

Complexity and transition to chaos in coupled Adler-type oscillators

Coupled non-linear oscillators are ubiquitous in dynamical studies. A wealth of behaviors have been found mostly for globally coupled systems. From a complexity perspective, less studied have been systems with local coupling, which is the subject of this contribution. The phase approximation is used, as weak coupling is assumed. In particular, the so called needle region, in parameter space, for Adler-type oscillators with nearest neighbors coupling is carefully characterized. The reason for this emphasis is that in the border of this region to the surrounding chaotic one, computation enhancement at the edge of chaos has been reported. The present study shows that different behaviors within the needle region can be found, and a smooth change of dynamics could be identified. Entropic measures further emphasize the region's heterogeneous nature with interesting features, as seen in the spatiotemporal diagrams. The occurrence of wave-like patterns in the spatiotemporal diagrams points to non-trivial correlations in both dimensions. The wave patterns change as the control parameters change without exiting the needle region. Spatial correlation is only achieved locally at the onset of chaos, with different clusters of oscillators behaving coherently while disordered boundaries appear between them.Comment: revised version published in PHYSICAL REVIEW E 107, 044212 (2023

Allosteric Mechanism on DREAM Dimerization and Impact on Its Interactions with Divalent Metal Zn2+

DREAM belongs to the NCS family, and it is involved in several physiological processes mediated by Ca2+ association, which produces changes in its oligomerization state. The mechanism of how Ca2+ binds to DREAM remains unknown. A kinetic study of the binding of Ca2+ to DREAM suggested that DREAM dimerization is a two-step process, the first step( τ1= 8±0.1ms) is associated with the binding of Ca2+ to the monomer, while the second step (τ2 = 3.6 ±0.4 s ) corresponds to a conformation relaxation that leads to the dimerization. Furthermore, by analyzing the fast kinetic k obsvs[L] , an inverse hyperbolic dependance was observed , which corresponds to the conformational selection mechanism providing crucial information on the binding of Ca2+ to DREAM. Previous MD studies has shown that a network of hydrophobic residues in DREAM participate in the transmission of the interdomain allosteric signal. The Trp169 is part of this network, MD analysis were performed to determine its role in allosteric signal transmission. The mutation of Trp to Ala lead to a loss of structural rearrangement previously observed upon Ca2+ binding. For instance, in the case of DREAMW169A the stabilizing salt bridge K87-E165 was not present , the EF hands in the mutant did not undergo the reorientation observed in DREAMWT and the dimer divided into two monomers in the presence of Ca2+. These findings suggest the Trp169 is involved in the interdomain communication in DREAM, and it is crucial for the protein proper functioning. Zn2+ is involved in several physiological processes and interacts with a wide variety of proteins , including other NCS proteins. DREAM also interacts with divalent metals with relatively high affinity . The presence of Zn2+ produces changes in DREM’s tertiary structure , and it is able to bind to DREAM in the presence(Kd=10.76± 1.46 and µM) and absence of Ca2+ (Kd=6.9 ± 0.6 µM). For the MD studies in the presence and absence of Ca2+, Zn2+ was found to bind to the protein involving amino acids located in EFH2. These findings suggest that Zn2+ may be involved in processes possibly involving DREAM and other NCS

Molecular Mechanism of DREAM Dimerization and Interactions with a Non-physiological Ligand Zn2+.

Downstream Regulatory Element Antagonist Modulator (DREAM) belongs to the family of neuronal calcium sensor proteins and it is involved in several processes in the brain. Zinc has been shown to bind to recoverin, with submillimolar affinity. Based on the high sequence homology between the NCS family, it is proposed that DREAM can also serve as an intracellular target for Zn2+. Fluorescence and CD studies confirm that zinc binds to DREAM with a of Kd = 4 µM, triggering changes in the proteins’ tertiary structure. The calcium association to DREAM leads to the formation of a Ca2+ bound dimer, while in the apo state, a monomer-tetramer equilibrium was observed. A chimeric version of DREAM was prepared by mutating the residues involved in dimerization. DREAM-NCS1 properties were investigated using spectroscopic techniques. These results point towards the role of hydrophobic interactions and salt bridges in stabilizing the dimer and propagating allosteric signals

Management and orchestration of virtual network functions via deep reinforcement learning

Management and orchestration (MANO) of re-sources by virtual network functions (VNFs) represents one of thekey challenges towards a fully virtualized network architectureas envisaged by 5G standards. Current threshold-based policiesinefficiently over-provision network resources and under-utilizeavailable hardware, incurring high cost for network operators,and consequently, the users. In this work, we present a MANOalgorithm for VNFs allowing a central unit (CU) to learnto autonomously re-configure resources (processing power andstorage), deploy new VNF instances, or offload them to the cloud,depending on the network conditions, available pool of resources,and the VNF requirements, with the goal of minimizing a costfunction that takes into account the economical cost as wellas latency and the quality-of-service (QoS) experienced by theusers. First, we formulate the stochastic resource optimizationproblem as a parameterized action Markov decision process(PAMDP). Then, we propose a solution based on deep reinforce-ment learning (DRL). More precisely, we present a novel RLapproach, called parameterized action twin (PAT) deterministicpolicy gradient, which leverages anactor-critic architecturetolearn to provision resources to the VNFs in an online manner.Finally, we present numerical performance results, and map themto 5G key performance indicators (KPIs). To the best of ourknowledge, this is the first work that considers DRL for MANOof VNFs’ physical resources