A test of the hypothesis that impact-induced fractures are preferred sites for later tectonic activity

Impact cratering has been an important process in the solar system. The cratering event is generally accompanied by faulting in adjacent terrain. Impact-induced faults are nearly ubiquitous over large areas on the terrestrial planets. The suggestion is made that these fault systems, particularly those associated with the largest impact features are preferred sites for later deformation in response to lithospheric stresses generated by other processes. The evidence is a perceived clustering of orientations of tectonic features either radial or concentric to the crater or basin in question. An opportunity exists to test this suggestion more directly on Earth. The terrestrial continents contain more than 100 known or probable impact craters, with associated geological structures mapped to varying levels of detail. Prime facie evidence for reactivation of crater-induced faults would be the occurrence of earthquakes on these faults in response to the intraplate stress field. Either an alignment of epicenters with mapped fault traces or fault plane solutions indicating slip on a plane approximately coincident with that inferred for a crater-induced fault would be sufficient to demonstrate such an association

Biological control networks suggest the use of biomimetic sets for combinatorial therapies

Cells are regulated by networks of controllers having many targets, and targets affected by many controllers, but these "many-to-many" combinatorial control systems are poorly understood. Here we analyze distinct cellular networks (transcription factors, microRNAs, and protein kinases) and a drug-target network. Certain network properties seem universal across systems and species, suggesting the existence of common control strategies in biology. The number of controllers is ~8% of targets and the density of links is 2.5% \pm 1.2%. Links per node are predominantly exponentially distributed, implying conservation of the average, which we explain using a mathematical model of robustness in control networks. These findings suggest that optimal pharmacological strategies may benefit from a similar, many-to-many combinatorial structure, and molecular tools are available to test this approach.Comment: 33 page

Failure Probabilities and Tough-Brittle Crossover of Heterogeneous Materials with Continuous Disorder

The failure probabilities or the strength distributions of heterogeneous 1D systems with continuous local strength distribution and local load sharing have been studied using a simple, exact, recursive method. The fracture behavior depends on the local bond-strength distribution, the system size, and the applied stress, and crossovers occur as system size or stress changes. In the brittle region, systems with continuous disorders have a failure probability of the modified-Gumbel form, similar to that for systems with percolation disorder. The modified-Gumbel form is of special significance in weak-stress situations. This new recursive method has also been generalized to calculate exactly the failure probabilities under various boundary conditions, thereby illustrating the important effect of surfaces in the fracture process.Comment: 9 pages, revtex, 7 figure

Reply to the comment by Jacobs and Thorpe

Reply to a comment on "Infinite-Cluster geometry in central-force networks", PRL 78 (1997), 1480. A discussion about the order of the rigidity percolation transition.Comment: 1 page revTe

Self-Attracting Walk on Lattices

We have studied a model of self-attracting walk proposed by Sapozhnikov using Monte Carlo method. The mean square displacement $\sim t^{2\nu}$ and the mean number of visited sites $\sim t^{k}$ are calculated for one-, two- and three-dimensional lattice. In one dimension, the walk shows diffusive behaviour with $\nu=k=1/2$. However, in two and three dimension, we observed a non-universal behaviour, i.e., the exponent $\nu$ varies continuously with the strength of the attracting interaction.Comment: 6 pages, latex, 6 postscript figures, Submitted J.Phys.

ADOPTION OF SUPPLEMENTAL WORK-AT-HOME: A COMPARATIVE ANALYSIS

The primary purpose of this study is to develop a deeper understanding of the dynamics of the adoption of SWAH. Specifically, it examines how the work and family environments of dual-career male and female and traditional male parents who perform SWAH differ from the work and family environments of their cohorts who do not. People who perform SWAH were found to work significantly more hours per week and more hours at home than those who did not adopt SWAH. The data indicates that men and women who have higher level more challenging jobs (Le., greater work expectations and lower role clarity) were more likely to adopt SWAH than were men and women with fewer career demands. There were no significant differences in the family environments of men who did and did not adopt SWAH. Perceived family responsibility (i.e., family involvement, family expectations) was associated with a woman\u27s tendency to adopt SWAH

Does Religiosity Affect Stock Investors’ Herding Behaviour? Global Evidence

We investigate if religiosity promotes herding among stock market investors. In a global sample of 21 markets over the period 2006–2018, increasing religiosity fosters herding only when the absolute religiosity level is relatively high. At low levels, an increase in religiosity has the opposite effect, promoting anti-herding. Our finding that changes in religiosity, depending on its level (high versus low), exert opposing effects on herding helps to understand contradictory findings in prior literature. Religiosity further induces more herding when economic freedom is low and the state is either impotent or corrupt, and promotes anti-herding when institutional quality is high

On Perceptions of Financial Volatility in Price Sequences

Stock prices in financial markets rise and fall, sometimes dramatically, thus asset returns exhibit volatility. In finance theory, volatility is synonymous with risk and as such represents the dispersion of asset returns about their central tendency (i.e. mean), measured by the standard deviation of returns. When individuals make investment decisions, influenced by perceptions of risk and volatility, they commonly do so by examining graphs of historic price sequences rather than returns. It is unclear, therefore, whether standard deviation of return is foremost in their mind when making such decisions. We conduct two experiments to examine the factors that may influence perceptions of financial volatility, including standard deviation along with a number of price-based factors. Also of interest is the influence of price sequence regularity on perceived volatility. While standard deviation may have a role to play in perception of volatility, we find evidence that other price-based factors play a far greater role. Furthermore, we report evidence to support the view that the extent to which prices appear irregular is a separate aspect of volatility, distinct from the extent to which prices deviate from central tendency. Also, while partially correlated, individuals do not perceive risk and volatility as synonymous, though they are more closely related in the presence of price sequence irregularity

Extremal statistics in the energetics of domain walls

We study at T=0 the minimum energy of a domain wall and its gap to the first excited state concentrating on two-dimensional random-bond Ising magnets. The average gap scales as $\Delta E_1 \sim L^\theta f(N_z)$, where $f(y) \sim [\ln y]^{-1/2}$, $\theta$ is the energy fluctuation exponent, $L$ length scale, and $N_z$ the number of energy valleys. The logarithmic scaling is due to extremal statistics, which is illustrated by mapping the problem into the Kardar-Parisi-Zhang roughening process. It follows that the susceptibility of domain walls has also a logarithmic dependence on system size.Comment: Accepted for publication in Phys. Rev.

Scaling of interfaces in brittle fracture and perfect plasticity

The roughness properties of two-dimensional fracture surfaces as created by the slow failure of random fuse networks are considered and compared to yield surfaces of perfect plasticity with similar disorder. By studying systems up to a linear size L=350 it is found that in the cases studied the fracture surfaces exhibit self-affine scaling with a roughness exponent close to 2/3, which is asymptotically exactly true for plasticity though finite-size effects are evident for both. The overlap of yield or minimum energy and fracture surfaces with exactly the same disorder configuration is shown to be a decreasing function of the system size and to be of a rather large magnitude for all cases studied. The typical ``overlap cluster'' length between pairs of such interfaces converges to a constant with $L$ increasing.Comment: Accepted for publication in Phys. Rev.