The structure and composition of exhumed faults, and their implications for seismic processes

Field studies of faults exhumed from seismogenic depths provide useful data to constrain seismologic models of fault zone processes and properties. Data collected on the San Andreas Fault in the San Gabriel Mountains has shown that large-displacement faults consist of one to several very narrow slip zones embedded in a cataclastically deformed sheared region several meters thick. However these faults have not been buried to depths greater than 5 km. Fault zones in the Sierra Nevada, California allow us to study the microstructures resulting from the deformation mechanisms active at seismogenic depths. Syn-fault mineralization shows that these left-lateral strike-slip faults formed at 5-12 km depth. Detailed microstructural analyses of the small faults reveal that they evolved from cooling joints filled by chlorite, epidote and quartz. These joints were then reactivated to form shear faults with accompanying brittle fracture and cataclastic deformation, ultimately developing very fined-grained cataclasites and ultracataclasites. The shear-induced microstructures are developed on faults with as little as several mm of slip showing that narrow slip-surfaces develop early in the lifetime of these faults. Subsequent slip has little effect on the microstructures. The inferred similarity of deformation mechanisms in faults 10 m to 10 km long indicates that basic slip processes on the faults are scale invariant, and may be a cause for the inferred constant b-value for small earthquakes. Analysis of map-scale fault linkages and terminations indicate that linkage zones are up to 400 m wide and 1 km long, and consist of altered and fractured rocks with numerous through-going slip surfaces. Terminations are regions of numerous splay faults that have cumulative offsets approaching those of the main faults. The slip distribution and structure of the terminations and linkage zones suggest that seismic slip may propagate into these zones of enhanced toughness, and that through-going slip can occur when a sufficient linkage of faults in the zone allow slip to be transmitted

Validating Sample Average Approximation Solutions with Negatively Dependent Batches

Sample-average approximations (SAA) are a practical means of finding approximate solutions of stochastic programming problems involving an extremely large (or infinite) number of scenarios. SAA can also be used to find estimates of a lower bound on the optimal objective value of the true problem which, when coupled with an upper bound, provides confidence intervals for the true optimal objective value and valuable information about the quality of the approximate solutions. Specifically, the lower bound can be estimated by solving multiple SAA problems (each obtained using a particular sampling method) and averaging the obtained objective values. State-of-the-art methods for lower-bound estimation generate batches of scenarios for the SAA problems independently. In this paper, we describe sampling methods that produce negatively dependent batches, thus reducing the variance of the sample-averaged lower bound estimator and increasing its usefulness in defining a confidence interval for the optimal objective value. We provide conditions under which the new sampling methods can reduce the variance of the lower bound estimator, and present computational results to verify that our scheme can reduce the variance significantly, by comparison with the traditional Latin hypercube approach

Role of ABCB1 C3435T variant in response to antiepileptic drugs in epilepsy: a review

Over-expression of P-glycoprotein (P-gp), the encoded product of the ATP-binding cassette (ABC), sub-family B, member 1 (ABCB1/MDR1) gene, plays an important role in mediating multidrug resistance to antiepileptic drugs (AEDs) in about 30% of patients with epilepsy. Genetic variation may in part explain inter-individual differences in phenotype-genotype relationships in the pharmacological response of epilepsy patients to AEDs. The synonymous C3435T polymorphism is one of the most common allelic variants in the ABCB1/MDR1 gene, proposed in the causation of refractory epilepsy. Many studies have shown the relationship between C3435T polymorphism and refractoriness to AEDs in epilepsy. However, there is controversy between the findings of various studies, that is, whether ABCB1/MDR1 C3435T gene polymorphism is associated with response to AEDs in epilepsy patients. This review provides a background and discusses the results of investigations on possible confounding factors affecting the interpretation and implementation of association studies in this area

Density dependence of the Ionization Avalanche in ultracold Rydberg gases

We report on the behaviour of the ionization avalanche in an ensemble of ultracold 87Rb atoms coupled to a high lying Rydberg state and investigate extensions to the current model by including the effects of three-body recombination and plasma expansion. To separate the two effects we study the time dependence of the plasma formation at various densities as well as for different nS and nD states. At medium densities and low n we observe the onset of the avalanche as has been reported in other experiments, as well as a subsequent turn-off of the avalanche for longer excitation times, which we associate with plasma expansion. At higher densities and for higher lying Rydberg states we observe a disappearance of the avalanche signature, which we attribute to three-body recombination.Comment: 5 pages, 4 figure

Development of a leakage target setting approach for South Korea based on Economic Level of Leakage

Published13th Computer Control for Water Industry Conference, CCWI 2015Leakage has become a crucial issue that needs to be addressed effectively by water suppliers in terms of economic management of water systems. A target setting method based on the ELL (Economic Level of Leakage) calculation is proposed in this paper. The methodology applied is developed specifically for the South Korean context to select a minimum achievable level of NRW (Non-Revenue Water) and verify the appropriateness of the current target within existing financial constraints by using limited available data. This approach is focused on the derivation of the NRW control cost curve by using the newly developed cumulative method that minimizes data fluctuation and enhances the cost curve reliability. This has been applied to a case study by using data collected from the water supplier information system. The results obtained in this case study show significant outcomes in respect of both identification of an economically optimal target and prevention of unnecessary investment to meet this aim. This advance in leakage management allows water suppliers to select a rational target and manage their system economically and efficiently.This work has been funded and supported by K-water which is the public water company in South Kore

From strategy, to accounting : accounting practice and strategic discourse in the telecommunications industry

Following Roberts (1990) and Dent (1990). this study investigates the importance of complexifying the relationship between strategy and accounting. The genealogical approach of Hoskin et al (1997) provides inspiration as to the ways in which strategic discourse (itself promoted as a subject of study by Knights and Morgan (1990,1991,1995)) is historically contingent upon practices of accounting. I take up this task of inaugurating the study of accounting practice and strategy discourse, from strategy to accounting, to develop a new perspective of how their interaction takes place. This gives birth to a re-reading of the strategy (and accounting) literatures, from the direction of a constitutive notion of accounting practices. In particular, the processual and critical schools of strategy are found to promote conventional notions of accounting as mirror, as secondary and passive practice, which circulate beneath the usual level of visibility. Building on this emergent approach, a post- Foucauldian theory of practices is outlined from a methodological viewpoint. This approach does not begin from such general categories as 'the individual', 'the social' or 'the economic', and thereby does not follow conventional understandings of 'doing ethnography'. The inquiry is empirically situated within the context of a longitudinal investigation (1997-2000) into the U. K. based part of a global telecommunications company, Teleco. I discover complex interactions between accounting practices and the workings of strategy, both as presence and absence. There is a partial presence of strategy even within the most 'strategic' parts of Teleco, in conjunction with a growing absence within those parts most distant from 'the strategy'. Despite this, or perhaps because of this, the spread of accounting and accounting based-practices rolls on, albeit in a non-uniform way. This brings forth the possibility of a strategic accounting, one whose practices are perhaps most visibly internalised and effected on my very self, thus adding weight to the rejection within this thesis of the metaphysical categories of either 'strategy' or 'accounting