Mechanism of the slow-moving landslides in Jurassic red-strata in the Three Gorges Reservoir, China

Landslides in Jurassic red-strata make up a great part of geohazards in the Three Gorges Reservoir (TGR) in China. Most of them begin to move slowly with the accumulated displacement increasing stepwise, which corresponds to seasonal rainfall and 30 m of reservoir water level fluctuation (145 m to 175 m on elevation). We analyzed the movement of 21 slow moving landslides in the Jurassic red-strata in TGR, and found that all these landslides involved two differing processes; one is the sliding process with different shear speeds of soils within the sliding zone (landslide activity), and the other one is in steady state with different durations (dormant state). This means that the soil within the sliding surface may experience shearing at different shear rates and recovery in shear strength during the dormant period. To clarify the mechanism of this kind of movement, we took soil samples from the sliding surface of Xiangshanlu landslide, which occurred on August 30, 2008 in the Jurassic red-strata in TGR, and examined the shear rate dependency and recovery of shear resistance by means of ring shear tests. The results of tests at different shear rates show that the shear strength is positively dependent on the shear rate, and can be recovered within a short consolidation duration after the shearing ceased. By increasing the pore-water pressure (PWP) from the upper layer of the sample, we also examined the initiation of shearing which can simulate the restart of landsliding due to the fluctuation of groundwater level caused by rainfall or changes in reservoir water level. The monitored PWP near the sliding surface revealed that there was a delayed response of PWP near the sliding surface to the applied one. This kind of delayed response in pore-water pressure may provide help for the prediction of landslide occurrence due to rainfall or fluctuation of reservoir water level

MiR-429 suppresses the progression and metastasis of osteosarcoma by targeting ZEB1

MiR-429 functions as a tumor suppressor and has been observed in multiple types of cancer, but the effects and mechanisms of miR-429 in osteosarcoma are poorly understood. This study is performed to evaluate the functions of miR-429 in the progression of osteosarcoma. Firstly, the miR-429 expression in osteosarcoma tissues and oste- osarcoma cells was detected using real time PCR, and the relationship between miR-429 expression and overall survival of osteosarcoma was analyzed. Secondly, the effects of miR-429 on the migration, invasion, proliferation and apoptosis of osteosarcoma cells were evaluated using transwell assay, wound-healing assay, CCK-8 assay and flow cytometry, respectively. Proteins related to epithelial-mesenchymal transition (EMT), E-cadherin, Vimentin, N-cadherin and Snail, were also detected using Western blot. Finally, the target gene of miR-429 in osteosarcoma was predicted and verified using dual luciferase assay and the expression correlation between them was analyzed using Pearson’s correlation. MiR-429 was down-regulated in osteosarcoma tissues and osteosarcoma cells; the expression level of miR-429 was associated with the prognosis of osteosarcoma. High level of miR-429 in osteo- sarcoma cells significantly suppressed the migration, invasion and proliferation of cells but induced cells apopto- sis. Furthermore, high level of miR-429 in osteosarcoma cells obviously increased the expression of E-cadherin protein but decreased the expression of Vimentin, N-Cadherin and Snail proteins. EMT inducer ZEB1 was the target gene of miR-429 and the expression of ZEB1 was negatively related to the miR-429 expression in osteosar- coma. In conclusion, miR-429 may functions as a tumor suppressor and be down-regulated in osteosarcoma. MiR- 429 may suppress the progression and metastasis of osteosarcoma by down-regulating the ZEB1 expression

GP-NAS-ensemble: a model for NAS Performance Prediction

It is of great significance to estimate the performance of a given model architecture without training in the application of Neural Architecture Search (NAS) as it may take a lot of time to evaluate the performance of an architecture. In this paper, a novel NAS framework called GP-NAS-ensemble is proposed to predict the performance of a neural network architecture with a small training dataset. We make several improvements on the GP-NAS model to make it share the advantage of ensemble learning methods. Our method ranks second in the CVPR2022 second lightweight NAS challenge performance prediction track

Shop The Look: Building a Large Scale Visual Shopping System at Pinterest

As online content becomes ever more visual, the demand for searching by visual queries grows correspondingly stronger. Shop The Look is an online shopping discovery service at Pinterest, leveraging visual search to enable users to find and buy products within an image. In this work, we provide a holistic view of how we built Shop The Look, a shopping oriented visual search system, along with lessons learned from addressing shopping needs. We discuss topics including core technology across object detection and visual embeddings, serving infrastructure for realtime inference, and data labeling methodology for training/evaluation data collection and human evaluation. The user-facing impacts of our system design choices are measured through offline evaluations, human relevance judgements, and online A/B experiments. The collective improvements amount to cumulative relative gains of over 160% in end-to-end human relevance judgements and over 80% in engagement. Shop The Look is deployed in production at Pinterest.Comment: 10 pages, 7 figures, Accepted to KDD'2

Sr²⁺ Ion Substitution Enhanced Dielectric Properties of Co₍₂₎Z Ferrites for VHF Antenna Substrate

The effect of Sr2+ ions on the microstructure and high frequency properties of 2.5 wt% Bi2O3 added to Co(2)Z hexaferrites (3Ba(1-x)SrxO•2CoO•12Fe2O3, x = 0.0, 0.2, 0.4 and 0.6) synthesised using the solid-state reaction method was investigated. Experimental results indicate that the dielectric properties were markedly enhanced with the increase in the content of Sr2+ ions, thereby increasing the miniaturisation factor, which enables a size reduction in a long frequency range. Slight changes to saturation magnetisation (Ms) and coercivity (Hc) were observed, i.e., the saturation magnetisation (Ms) decreased from 39.99 to 38.11 emu/g, and coercivity (Hc) increased from 59.05 to 65.21 Oe when x increased from 0.0 to 0.6. Meanwhile, ε′ increased from approximately 8 to 12, indicating the invariability in μ′. In addition, the processed materials exhibit relatively low magnetic loss and dielectric loss (magnetic loss tanδμ ≈ 0.08 and dielectric loss (tanδε ≈ 0.007)). These results indicate that the substituted CO(2)Z ferrites have excellent potential in high-frequency antenna applications

Sr2+ Ion Substitution Enhanced Dielectric Properties of Co(2)Z Ferrites for VHF Antenna Substrate

The effect of Sr2+ ions on the microstructure and high frequency properties of 2.5 wt% Bi2O3 added to Co(2)Z hexaferrites (3Ba(1-x)SrxO•2CoO•12Fe2O3, x = 0.0, 0.2, 0.4 and 0.6) synthesised using the solid-state reaction method was investigated. Experimental results indicate that the dielectric properties were markedly enhanced with the increase in the content of Sr2+ ions, thereby increasing the miniaturisation factor, which enables a size reduction in a long frequency range. Slight changes to saturation magnetisation (Ms) and coercivity (Hc) were observed, i.e., the saturation magnetisation (Ms) decreased from 39.99 to 38.11 emu/g, and coercivity (Hc) increased from 59.05 to 65.21 Oe when x increased from 0.0 to 0.6. Meanwhile, ε′ increased from approximately 8 to 12, indicating the invariability in μ′. In addition, the processed materials exhibit relatively low magnetic loss and dielectric loss (magnetic loss tanδμ ≈ 0.08 and dielectric loss (tanδε ≈ 0.007)). These results indicate that the substituted CO(2)Z ferrites have excellent potential in high-frequency antenna applications

Analysis of Baishuihe landslide influenced by the effects of reservoir water and rainfall

Since the impoundment of the Three Gorges Reservoir in June 2003, a number of new landslides have occurred and existing landslides have been made worse. The 1,260 × 104 m3 Baishuihe landslide, located at 56 km west of the Three Gorges Dam, began to deform more noticeably after the first impoundment in early July 2003. The sliding of the two blocks comprising the landslide, one an active block and the other a relatively stable block, became apparent after approximately 5 years of monitoring. Field recordings show that the landslide displacement is affected by the combined effects of the rainfall and water level in the reservoir. These effects have been investigated in the present paper, including the deformation characteristics (movement pattern, direction, displacement and velocity) earmarking the temporal evolution of the active block. Based on a practical creep model of a large rock slide, alert velocity thresholds for pre-alert, alert and emergency phases have been computed corresponding to the imminence of failure. The alert velocity thresholds are being proposed to be included as a part of an early-warning system of an emergency plan drawn up to minimize the adverse impact in the event of landslide failure. The emergency plan is intended to be implemented as a risk management tool by the relevant authorities of the Three Gorges Reservoir in the near future

Improved slope unit method for fine evaluation of regional landslide susceptibility

Susceptibility evaluation is the basis of regional landslide risk early warning and stability analysis. Scientific and reasonable division of evaluation unit is the key to landslide susceptibility evaluation. For large-scale fine landslide susceptibility evaluation, the traditional slope unit division method based on hydrology and geomorphology generally results in low accuracy of the evaluation. In this paper, an improved slope unit method based on the slope geological environment is proposed. Dazhou Town was selected as an example and the obtained results from the proposed model were compared with the results from hydrological analysis method and curvature watershed method. The results show that the size uniformity of the evaluation units divided by the proposed method is better, and no fine units or deformed long strip units were generated. The overall morphological characteristics of the evaluation unit are more reasonable, and the morphological index is between 1 and 2, which generally presents circular-like or square-like shape. At the same time, the superposition degree between the results of the improved slope unit division and the range of the existing disaster boundary is the highest, which can better reflect the physical significance of landslide risk assessment. The proposed model has significant potential for improving the accuracy of regional landslide susceptibility evaluation

Study on the effect of tower foundation landslide protection measures based on a physical model test

A large number of high voltage transmission tower foundations crossing mountainous and hilly areas are often located in high-prone slope areas of landslide disasters. Applying appropriate protective measures to improve their stability is the key to ensuring the continuous and safe operation of transmission lines. To study the protection effect of different protection measures on the tower foundation landslide, this paper takes the Yanzi landslide in Badong County, Hubei Province as a geological prototype, designs and produces a physical test model, and carries out physical model tests of the landslide under extreme rainfall conditions(50, 100 mm/h) without protection, applying anti-slide piles and lattice protection. The deformation and failure characteristics of the landslide and the protective effect of different protective measures are revealed from the experimental point of view. The results show that under two extreme conditions, the unprotected landslide experienced the evolution process of slope surface erosion, crack propagation, local collapse and deformation, and overall sliding. The anti-slide pile measures have a significant effect on the overall protection of the landslide. The landslide is in a stable state, the deformation of the tower foundation is small, and the inclination rate of the tower meets the specification, but the slope surface will be scoured and collapsed. Lattice slope protection measures can effectively reduce the risk of slope erosion and slope toe collapse, but the overall stabilization of the tower foundation under continuous heavy rainfall is slightly weaker. The model test results are consistent with the historical deformation of the landslide and the actual treatment effect. The test conclusions can provide a reference for the failure mechanism research and protection engineering design of similar tower foundation landslides