Evolution of Off-Fault Deformation along Analog Strike-Slip Faults

Strike-slip faults evolve to accommodate more fault slip, resulting in less off-fault deformation. In analog experiments, the measured fault slip to off-fault deformation ratios are similar to those measured in crustal strike-slip systems, such as the San Andreas fault system. Established planar faults have the largest fault slip to off-fault deformation ratio of ~0.98. In systems without a pre-existing fault surface, crustal thickness and basal detachment conditions affect shear zone width and roughness. However, once the applied plate displacement is 1-2 times the crustal thickness, partitioning of deformation between fault slip and off-fault distributed shear is \u3e0.90, regardless of the basal boundary conditions. In addition, at any moment during the evolution of the analog fault system, the ratio of fault slip to off-fault deformation is larger than the cumulative ratio. We also find that the upward and lateral propagation of faults as an active shear zone developing early in the experiments has greater impact on the system’s strike-slip efficiency than later interaction between non-collinear fault segments. For bends with stepover distance of twice the crustal thickness, the fault slip to off-fault deformation ratio increases up to ~0.80-0.90, after applied plate displacement exceeds twice the crustal thickness. Propagation of new oblique-slip faults around sharp restraining bends reduces the overall off-fault deformation within the fault system. In contrast, fault segments within gentle restraining bends continue to slip and the propagation of new oblique-slip faults have less effect on the system’s efficiency than for sharp restraining bends

Moderate Growth Time Series for Dynamic Combinatorics Modelisation

Here, we present a family of time series with a simple growth constraint. This family can be the basis of a model to apply to emerging computation in business and micro-economy where global functions can be expressed from local rules. We explicit a double statistics on these series which allows to establish a one-to-one correspondence between three other ballot-like strunctures

Regulation of the Drosophila Initiator Caspase Dronc through Ubiquitylation

Apoptosis is a programmed cell death mechanism that is evolutionary conserved from worms to humans. Apoptosis is mediated by initiator and effector caspases. The initiator caspases carry long pro-domains for their interaction with scaffolding proteins to form a cell-death platform, which is essential for their activation. Activated initiator caspases then cleave effector caspases that execute cell death through cleaving downstream targets. In addition to their apoptotic function, caspases also participate in events where caspase activity is not required for cell killing, but for regulating other functions, so-called non-apoptotic functions of caspases. The Drosophila initiator caspase Dronc, the ortholog of mammalian caspase-2 and caspase-9 has a CARD domain that is essential for its interaction with the scaffolding protein Dark to form the apoptosome. Apoptosome formation is crucial for activation of Dronc. Activity of both initiator and effector caspases are further kept in control by the ubiquitin system to avoid inappropriate caspase activity. However, mechanistic details of how the ubiquitin system regulates activation of Dronc are not clear. Therefore, I investigated the ubiquitylation status of Dronc and its function in Drosophila. I found that Dronc is mono-ubiquitylated at Lys78 (K78) in its CARD domain, which blocks its interaction with Dark and formation of the apoptosome. Furthermore, I demonstrated that K78 mono-ubiquitylation plays an inhibitory role in Dronc’s non-apoptotic functions, which may not require its catalytic activity but may be important for the survival of the fly. This thesis study unveils the link between the ubiquitin system and caspases through a regulatory mechanism where a single mono-ubiquitylation event could inhibit both apoptotic and non-apoptotic functions of a caspase

Scalable and Cost Efficient Algorithms for Virtual CDN Migration

Virtual Content Delivery Network (vCDN) migration is necessary to optimize the use of resources and improve the performance of the overall SDN/NFV-based CDN function in terms of network operator cost reduction and high streaming quality. It requires intelligent and enticed joint SDN/NFV migration algorithms due to the evident huge amount of traffic to be delivered to end customers of the network. In this paper, two approaches for finding the optimal and near optimal path placement(s) and vCDN migration(s) are proposed (OPAC and HPAC). Moreover, several scenarios are considered to quantify the OPAC and HPAC behaviors and to compare their efficiency in terms of migration cost, migration time, vCDN replication number, and other cost factors. Then, they are implemented and evaluated under different network scales. Finally, the proposed algorithms are integrated in an SDN/NFV framework. Index Terms: vCDN; SDN/NFV Optimization; Migration Algorithms; Scalability Algorithms.Comment: 9 pages, 11 figures, 4 tableaux, conference Local Computer Networks (LCN), class

Hydrogen Production in the Cyanobacterium Synechocystis sp. PCC 6803 with Engineered Subunit of the Bidirectional H2-ase

Hydrogenase (H2-ase) enzyme holds great promise as a bio-generator for bio-solar hydrogen (H2) production. Consequently, an oxygen-tolerant H2-ase is needed in a photosynthetic organism.  In this work, a mutant strain of Synechocystis sp. PCC 6803 with modified H2-ase analyzed under various physiological conditions. The growth rate was higher than that of wt strain and cellular capacity to fix carbon was increased, as shown by higher glycogen accumulation. Oxygen evolution by mutant strain in chemostats was higher than by wt cells over a range of pH levels. The mutant displayed significantly higher hydrogen (H2) production than wt cells, especially at high pH. Examinations of electron flow pathways in the presence of various inhibitors indicated that the genetically modified H2-ase apparently behaves similarly to the wt with respect to its electron source. Remarkably, it was consistently observed H2 production under continuous light conditions, in the presence of oxygen (O2), under many circumstances in both chemostat and batch tests. H2 production in the light was improved under alkaline pH in mutant strain than wt. The data suggest that the genetically modified hydrogenase (H2ase) is a functionally active. Several lines of evidence suggest that O2 may be important in draining electrons from the donor side of photosystem I (PSI) in turn increases the linear electron flow and thereby helping to feed the H2ase activity. In conclusion, the bidirectional H2ase in Synechocystis may play a critical role in cell physiology not only under anoxic conditions but also under O2-evolving activity. Keywords: Cyanobacteria, Hydrogen, Hydrogenase, Protein engineering