Land subsidence over oilfields in the Yellow River Delta

Subsidence in river deltas is a complex process that has both natural and human causes. Increasing human activities like aquaculture and petroleum extraction are affecting the Yellow River delta, and one consequence is subsidence. The purpose of this study is to measure the surface displacements in the Yellow River delta region and to investigate the corresponding subsidence source. In this paper, the Stanford Method for Persistent Scatterers (StaMPS) package was employed to process Envisat ASAR images collected between 2007 and 2010. Consistent results between two descending tracks show subsidence with a mean rate up to 30 mm/yr in the radar line of sight direction in Gudao Town (oilfield), Gudong oilfield and Xianhe Town of the delta, each of which is within the delta, and also show that subsidence is not uniform across the delta. Field investigation shows a connection between areas of non-uniform subsidence and of petroleum extraction. In a 9 km2 area of the Gudao Oilfield, a poroelastic disk reservoir model is used to model the InSAR derived displacements. In general, good fits between InSAR observations and modeled displacements are seen. The subsidence observed in the vicinity of the oilfield is thus suggested to be caused by fluid extraction

Social Network Developing Process Driven by Conflict in Mass Contingency Events

AbstractTwo evolutionary mechanisms of mass contingency events are discussed, which are the cognition structure and the social network structure of the vulnerable groups and also the important problem in public security engineering of developing country. The paper analyzes the developing process of social network driven by conflict. Because the abundant participants share the expensive protest cost, the opinion leaders or sponsors organize the social network in the vulnerable group to maintain their legitimate rights and interests. The theoretical research shows that the protest strategy is feasible as soon as the social network reaches the minimal numbers. The CHAM strike event in 2010 provides an excellent case to explain the three-phase developing process of mass contingency events and the hiberarchy social network driven by the conflict. Lastly, it makes the simulation analysis about the social network of the CHAM strike under the Netlogo platform, where the simulating result is in accordance with the theoretical analysis

Normobaric hyperoxia protects the blood brain barrier through inhibiting Nox2 containing NADPH oxidase in ischemic stroke

Normobaric hyperoxia (NBO) has been shown to be neuro- and vaso-protective during ischemic stroke. However, the underlying mechanisms remain to be fully elucidated. Activation of NADPH oxidase critically contributes to ischemic brain damage via increase in ROS production. We herein tested the hypothesis that NBO protects the blood-brain barrier (BBB) via inhibiting gp91phox (or called Nox2) containing NADPH oxidase in a mouse model of middle cerebral artery occlusion (MCAO). Wild-type C57/BL6 mice and gp91phoxknockout mice were given NBO (95% O2) or normoxia (21% O2) during 90-min MCAO, followed by 22.5 hrs of reperfusion. BBB damage was quantified by measuring Evans blue extravasation. The protein levels of matrix metalloproteinase-9 (MMP-9), tight junction protein occludin and gp91phox were assessed with western blot. Gel zymography was used to assess the gelatinolytic activity of MMP-9. In the wild type mice, cerebral ischemia and reperfusion led to remarkable Evans blue extravasation, significantly increased gp91phox and MMP-9 levels and decreased occludin levels in the ischemic brain tissue. In gp91phox knockout mice, the changes in Evans blue extravasation, MMP-9 and occludin were at much smaller magnitudes when compared to the wild type. Importantly, NBO treatment significantly reduced the changes in all measured parameters in wild type mice, while did not cause additional reductions in these changes when gp91phox was knocked out. These results indicate that activation of Nox2 containing NADPH oxidase is implicated in the induction of MMP-9, loss of occludin and BBB disruption in ischemic stroke, and inhibition of Nox2 may be an important mechanism underlying NBO-afforded BBB protection

A new monotypic genus and species from China, \u3cem\u3eLangxie feti\u3c/em\u3e gen. et sp. n. (Scorpiones: Buthidae)

A new monotypic genus, Langxie gen. n., is described from Xizang (Tibet), China. The new genus shares an important morphological character with Afrolychas Kovařík, 2019: absence of external accessory denticles (EADs) along the sixth row of median denticles (MDs) on the pedipalp movable finger. Langxie gen. n. is different from Afrolychas in the following aspects: loss of EAD near the proximally enlarged MD within each row (i. e., loss of all EAD on the movable finger; this also distinguishes the new genus from other related genera in the “(Ananteris + Isometrus)” clade (Štundlová et al., 2022)), subaculear tubercle armed with or without a secondary tubercle dorsally, immaculate color pattern, more slender appendages and metasoma, and less sexually dimorphic pectines. Langxie gen. n. further differs from another geographically close genus, Himalayotityobuthus Lourenço, 1997, by the presence of highly developed pectinal fulcra (vs. absent in Himalayotityobuthus), six rows of MDs on the pedipalp movable finger (vs. 7–8 in Himalayotityobuthus) and five pairs of lateral ocelli (vs. 3 in Himalayotityobuthus). The new species, Langxie feti sp. n., is small and slender, exhibiting no obvious sexual dimorphism in pedipalp and metasoma, but the sexes are visibly different in the relative size of median ocelli and coarseness of carapacial granulation. Lattice microstructures are prominently developed on its cuticle

High-precision Monte Carlo study of directed percolation in (d+1) dimensions

We present a Monte Carlo study of the bond and site directed (oriented) percolation models in $(d+1)$ dimensions on simple-cubic and body-centered-cubic lattices, with $2 \leq d \leq 7$. A dimensionless ratio is defined, and an analysis of its finite-size scaling produces improved estimates of percolation thresholds. We also report improved estimates for the standard critical exponents. In addition, we study the probability distributions of the number of wet sites and radius of gyration, for $1 \leq d \leq 7$.Comment: 11 pages, 21 figure