Historic seismicity near the source zone of the great 2008 Wenchuan earthquake: Implications for seismic hazards

In the past 500 years, 14 historical earthquakes, including one that caused a maximum intensity of IX, occurred over a distance of more than 300 km along the Longmen Shan thrust belt, including portions that did not rupture during the devastating Wenchuan earthquake sequence of May 12, 2008. Estimated locations of epicenters and trends of faulting during historical events complement information gathered after the 2008 sequence. In particular, in addition to the two fault splays that ruptured in 2008, there are additional seismogenic faults across the Longmen Shan belt, including those in the hinterland and in the foreland. In the latter case, the occurrence of moderate-sized historical earthquakes and the disproportionally wide region of reported damage in the Sichuan basin from large events within the Longmen Shan belt, probably an effect of low attenuation in the stable basin, calls for attention to the potential of seismic hazard in the heavily populated Chengdu basin. Moreover, long recurrence-intervals of great events, estimated from trenching of colluvium along the ruptures of the 2008 sequence, should not be taken as reliable estimates for somewhat smaller, but nonetheless highly destructive events along the Longmen Shan thrust belt

Slip rates on the Chelungpu and Chushiang thrust faults inferred from a deformed strath terrace along the Dungpuna river, west central Taiwan

The Chelungpu fault produced the September 1999 M_w = 7.6 Chi-Chi earthquake, central Taiwan. The shortening rate accommodated by this structure, integrated over several seismic cycles, and its contribution to crustal shortening across the Taiwanese range have remained unresolved. To address the issues, we focus our study on the Chelungpu and Chushiang thrust faults within the southernmost portion of the Chi-Chi rupture area. Structural measurements and available seismic profiles are used to infer the subsurface geometry of structures. The Chushiang and Chelungpu faults appear as two splay faults branching onto a common ramp that further north connects only to the Chelungpu surface trace. We survey a deformed strath terrace along the Dungpuna river, buried under a 11,540 ± 309 years old fill deposit. Given this age, the dip angles of the faults, and the vertical throw determined from the offset of the strath terrace across the surface fault traces, we estimate slip rates of 12.9 ± 4.8 and 2.9 ± 1.6 mm/yr on the Chelungpu and Chushiang faults, respectively. These yield a total shortening rate of 15.8 ± 5.1 mm/yr to be absorbed on their common decollement at depth. This total value is an upper bound for the slip rate on the Chelungpu fault further north, where the Chushiang fault disappears and transfers shortening to adjacent faults. Combining these results with the recently constrained shortening rate on the Changhua blind thrust reveals that all these frontal faults presently absorb most of the long-term horizontal shortening across the Taiwanese range. They thus stand as the major sources of seismic hazards in this heavily populated area. The return period of earthquakes similar to the Chi-Chi event over a ∼80 km long stretch of the Western Foothills is estimated to be ~64 years. This value is an underestimate because it assumes that all the faults locked during the interseismic period slip only during such large events. Comparison with historical seismicity suggests that episodic aseismic deformation might also play a major role in accommodating shortening

Modeling of a hydraulic arresting gear using fluid–structure interaction and isogeometric analysis

Fluid–structure interaction (FSI) analysis of a full-scale hydraulic arresting gear used to retard the forward motion of an aircraft landing on an aircraft-carrier deck is performed. The simulations make use of the recently developed core and special-purpose FSI techniques for other problem classes, specialized to the present application. A recently proposed interactive geometry modeling and parametric design platform for isogeometric analysis (IGA) is directly employed to create the arresting gear model, and illustrates a natural application of IGA to this problem class. The fluid mechanics and FSI simulation results are reported in terms of the arresting-gear rotor loads and blade structural deformation and vibration. Excellent agreement is achieved with the experimental results for the arresting gear design simulated in this work

Modulation of CXCR4, CXCL12, and Tumor Cell Invasion Potential In Vitro by Phytochemicals.

CXCR4 is a chemokine receptor frequently overexpressed on primary tumor cells. Organs to which these cancers metastasize secrete CXCL12, the unique ligand for CXCR4, which stimulates invasion and metastasis to these sites. Similar to our previous work with the chemoprotective phytochemical, 3,3'-diindolylmethane (DIM), we show here that genistein also downregulates CXCR4 and CXCL12 and subsequently lowers the migratory and invasive potentials of breast and ovarian cancer cells. Moreover, genistein and DIM elicit a significantly greater cumulative effect in lowering CXCR4 and CXCL12 levels than either compound alone. Our data suggest a novel mechanism for the protective effects of phytochemicals against cancer progression and indicate that in combination, these compounds may prove even more efficacious