Deformation Behaviour on the Simulation of Liquefaction in Particle Geomaterials

AbstractLiquefaction has recently been shown to occur in constitutive models at a critical value for the hardening modulus. Thus, the nearness of a soil element to liquefying at a given instant can be determined by finding the difference between its hardening modulus and its critical hardening modulus. The constitutive functions of the pore medium were described as follows: the evolution of the constitutive effective stress with imposed solid matrix deformation; the intrinsic mass densities with intrinsic pressure on all three phase; and the relative flow vector with intrinsic pressure for the water and air phase. The revelation has been applied herein to map the progression of static liquefaction in large scale boundary value problems under monotonic loading conditions. Simulations are presented to demonstrate how the proposed criterion can be applied to real-world situations. In addition, the influences of the loading rate and the mesh size on the liquefaction prediction are examined. The methodology proposed herein provides a powerful means of assessing liquefaction risk based on solid mechanical theory rather than empiricism. Results of the mesh size effect showed that the axial strains with the onset of the deformation band were different, if the mesh sizes were not the same even in the same sample

Issues of Reggeization in qq′qq' Back-Angle Scattering

The Kirschner-Lipatov result for the DLLA of high-energy $qq'$ backward scattering is re-derived without the use of integral equations. It is shown that part of the inequalities between the variables in the logarithmically-divergent integrals is inconsequential. The light-cone wave-function interpretation under the conditions of backward scattering is discussed. It is argued that for hadron-hadron scattering in the valence-quark model the reggeization should manifest itself at full strength starting from $s_{hh}=50 GeV^2$.Comment: 10 Pages, 2 Figures. To appear in Proc. of Int. Conf. "New Trends in High Energy Physics", 27 Sept.-4 Oct. 2008, Yalta, Crimea, Ukrain

Characterization of an endogenous gene expressed in Aedes aegypti using an orally infectious recombinant Sindbis virus

Sindbis virus expression vectors have been used successfully to express and silence genes of interest in vivo in several mosquito species, including Aedes aegypti, Ae. albopictus, Ae. triseriatus,Culex pipiens, Armigeres subalbatus and Anopheles gambiae. Here we describe the expression of an endogenous gene, defensin, in Ae. aegypti using the orally infectious Sindbis virus, MRE/3′2J expression vector. We optimized conditions to infect mosquito larvae per os using C6/36 Ae. albopictus cells infected with the recombinant virus to maximize virus infection and expression of defensin. Infection with the parental Sindbis virus (MRE/3′2J) did not induce defensin expression. Mosquito larvae infected by ingestion of recombinant Sindbis virus-infected C6/36 cells expressed defensin when they emerged as adults. Defensin expression was observed by western analysis or indirect fluorescent assay in all developmental stages of mosquitoes infected with MRE/3′2J virus that contained the defensin insert. The multiplicity of infection of C6/36 cells and the quantity of infected cells consumed by larvae played an important role in defensin expression. Parental viruses, missing the defensin insert, and/or other defective interfering virus may have contributed to these observations

Mining State-Based Models from Proof Corpora

Interactive theorem provers have been used extensively to reason about various software/hardware systems and mathematical theorems. The key challenge when using an interactive prover is finding a suitable sequence of proof steps that will lead to a successful proof requires a significant amount of human intervention. This paper presents an automated technique that takes as input examples of successful proofs and infers an Extended Finite State Machine as output. This can in turn be used to generate proofs of new conjectures. Our preliminary experiments show that the inferred models are generally accurate (contain few false-positive sequences) and that representing existing proofs in such a way can be very useful when guiding new ones.Comment: To Appear at Conferences on Intelligent Computer Mathematics 201

Adiponectin Prevents Diabetic Premature Senescence of Endothelial Progenitor Cells and Promotes Endothelial Repair by Suppressing the p38 MAP Kinase/p16INK4A Signaling Pathway

OBJECTIVE - A reduced number of circulating endothelial progenitor cells (EPCs) are casually associated with the cardiovascular complication of diabetes. Adiponectin exerts multiple protective effects against cardiovascular disease, independent of its insulin-sensitizing activity. The objective of this study was to investigate whether adiponectin plays a role in modulating the bioavailability of circulating EPCs and endothelial repair. RESEARCH DESIGN AND METHODS - Adiponectin knockout mice were crossed with db+/- mice to produce db/db diabetic mice without adiponectin. Circulating number of EPCs were analyzed by flow cytometry. Reendothelialization was evaluated by staining with Evans blue after wire-induced carotid injury. RESULTS - In adiponectin knockout mice, the number of circulating EPCs decreased in an age-dependent manner compared with the wild-type controls, and this difference was reversed by the chronic infusion of recombinant adiponectin. In db/db diabetic mice, the lack of adiponectin aggravated the hyperglycemia-induced decrease in circulating EPCs and also diminished the stimulatory effects of the PPARγ agonist rosiglitazone on EPC production and reendothelialization. In EPCs isolated from both human peripheral blood and mouse bone marrow, treatment with adiponectin prevented high glucose-induced premature senescence. At the molecular level, adiponectin decreased high glucose-induced accumulation of intracellular reactive oxygen species and consequently suppressed activation of p38 MAP kinase (MAPK) and expression of the senescence marker p16INK4A. CONCLUSIONS - Adiponectin prevents EPC senescence by inhibiting the ROS/p38 MAPK/p16 INK4A signaling cascade. The protective effects of adiponectin against diabetes vascular complications are attributed in part to its ability to counteract hyperglycemia-mediated decrease in the number of circulating EPCs. © 2010 by the American Diabetes Association.published_or_final_versio

Differential effect of the focal adhesion kinase Y397F mutant on v-Src-stimulated cell invasion and tumor growth

Upon cell adhesion to extracellular matrix proteins, focal adhesion kinase (FAK) rapidly undergoes autophosphorylation on its Tyr-397 which consequently serves as a binding site for the Src homology 2 domains of the Src family protein kinases and several other intracellular signaling molecules. In this study, we have attempted to examine the effect of the FAK Y397F mutant on v- Src- stimulated cell transformation by establishing an inducible expression of the Y397F mutant in v-Src-transformed FAK-null (FAK(-/-)) mouse embryo fibroblasts. We found that the FAK Y397F mutant had both positive and negative effects on v- Src- stimulated cell transformation; it promoted v- Src- stimulated invasion, but on the other hand it inhibited the v-Src-stimulated anchorage-independent cell growth in vitro and tumor formation in vivo. The positive e. ect of the Y397F mutant on v-Src- stimulated invasion was correlated with an increased expression of matrix metalloproteinase-2, both of which were inhibited by the specific phosphatidylinositol 3-kinase inhibitor wortmannin or a dominant negative mutant of AKT, suggesting a critical role for the phosphatidylinositol 3-kinase/AKT pathway in both events. However, the expression of the Y397F mutant rendered v- Src- transformed FAK(-/-) cells susceptible to anoikis, correlated with suppression on v-Src-stimulated activation of ERK and AKT. In addition, under anoikis stress, the induction of the Y397F mutant in v- Src- transformed FAK(-/-) cells selectively led to a decrease in the level of p130(Cas), but not other focal adhesion proteins such as talin, vinculin, and paxillin. These results suggest that FAK may increase the susceptibility of v- Src- transformed cells to anoikis by modulating the level of p130(Cas)

The Influences of Diesel Particulate Filter Installation on Air Pollutant Emissions for Used Vehicles

Three kinds of diesel particulate filters (DPFs) were installed on used diesel-powered vehicles to investigate their influences on air pollutant emissions. The air pollutant emissions were measured before, after and running for specific distances to assess the deterioration effect. The emission measurement was performed on a chassis dynamometer. The results show that emissions of smoke, CO and HC are all reduced after DPF installation. After 20000 km driving, the emission concentrations of the above 3 criteria air pollutants do not increase in comparison with that right after installation. When DPFs are installed, the emissions of PAHs (polycyclic aromatic hydrocarbons) are reduced by 85.6-89.4% and 69.0-89.2% for heavy-duty diesel vehicles (HDVs) and light-duty diesel vehicles (LDVs), respectively. After driving 20000 km for HDVs and 2500 km for LDVs, PAH emissions do not increase in comparison with that right after installation, indicating that the DPFs do not deteriorate after driving for the test mileages. The lower molecular weight PAHs predominates in the exhaust both before and after DPF installation. The results also show the reduction rate is higher for higher molecular weight PAHs due to their tendency to adsorb on particulate