Smart prediction of liquefaction-induced lateral spreading

The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(GEP).Based on statistical reasoning,individual models were developed for two topographies:free-face and gently sloping ground.Along with a comparison with conventional approaches for predicting the Dh,four additional regression-based soft computing models,i.e.Gaussian process regression(GPR),relevance vector machine(RVM),sequential minimal optimization regression(SMOR),and M5-tree,were developed and compared with the GEP model.The results indicate that the GEP models predict Dh with less bias,as evidenced by the root mean square error(RMSE)and mean absolute error(MAE)for training(i.e.1.092 and 0.815;and 0.643 and 0.526)and for testing(i.e.0.89 and 0.705;and 0.773 and 0.573)in free-face and gently sloping ground topographies,respectively.The overall performance for the free-face topology was ranked as follows:GEP>RVM>M5-tree>GPR>SMOR,with a total score of 40,32,24,15,and 10,respectively.For the gently sloping condition,the performance was ranked as follows:GEP>RVM>GPR>M5-tree>SMOR with a total score of 40,32,21,19,and 8,respectively.Finally,the results of the sensitivity analysis showed that for both free-face and gently sloping ground,the liquefiable layer thickness(T_(15))was the major parameter with percentage deterioration(%D)value of 99.15 and 90.72,respectively.

Influence of network structure on spreading dynamics via tie range

There are various phenomena of malicious information spreading in the real society, which cause many negative impacts on the society. In order to better control the spreading, it is crucial to reveal the influence of network structure on network spreading. Motifs, as fundamental structures within a network, play a significant role in spreading. Therefore, it is of interest to investigate the influence of the structural characteristics of basic network motifs on spreading dynamics.Considering the edges of the basic network motifs in an undirected network correspond to different tie ranges, two edge removal strategies are proposed, short ties priority removal strategy and long ties priority removal strategy. The tie range represents the second shortest path length between two connected nodes. The study focuses on analyzing how the proposed strategies impact network spreading and network structure, as well as examining the influence of network structure on network spreading. Our findings indicate that the long ties priority removal strategy is most effective in controlling network spreading, especially in terms of spread range and spread velocity. In terms of network structure, the clustering coefficient and the diameter of network also have an effect on the network spreading, and the triangular structure as an important motif structure effectively inhibits the spreading.

Individual dynamics and local heterogeneity provide a microscopic view of the epidemic spreading

The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the widely used deterministic compartmental models have qualitatively presented continuous “analytical” insight and captured some transmission features,their treatment usually lacks spatiotemporal variation.Here,we propose a stochastic individual dynamical(SID)model to mimic the random and heterogeneous nature of epidemic propagation.The SID model provides a unifying framework for representing the spatiotemporal variations of epidemic development by tracking the movements of each individual.Using this model,we reproduce the infection curves for COVID-19 cases in different areas globally and find the local dynamics and heterogeneity at the individual level that affect the disease outbreak.The macroscopic trend of virus spreading is clearly illustrated from the microscopic perspective,enabling a quantitative assessment of different interventions.Seemingly,this model is also applicable to studying stochastic processes at the “meter scale”,e.g.,human society’s collective dynamics.

Possible Cortical Spreading Depression Recorded Intraoperatively Following a Generalized Seizure: Illustrative Case

Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy for revascularization. Cortical spreading depression (CSD, also called cortical spreading depolarization) is a pathophysiological phenomenon whereby a wave of depolarization is thought to propagate across the cerebral cortex, creating a brief period of relative neuronal inactivity. The relationship between CSD and seizures is unclear, although some literature has made a correlation between seizures and a cortical environment conducive to CSD. Methods: Intraoperative somatosensory evoked potentials (SSEPs) and electroencephalography (EEG) were monitored continuously during the craniotomy procedure utilizing standard montages. Electrophysiological data from pre-ictal, ictal, and post-ictal periods were recorded. Results: During the procedure, intraoperative EEG captured a generalized seizure followed by a stepwise decrease in somatosensory evoked potential cortical amplitudes, compelling for the phenomenon of CSD. The subsequent partial recovery of neuronal function was also captured electrophysiologically. Discussion: While CSD is considered controversial in some aspects, intraoperative neurophysiological monitoring allowed for the unique analysis of a case demonstrating a CSD-like phenomenon. To our knowledge, this is the first published example of this phenomenon in which intraoperative neurophysiological monitoring captured a seizure, along with a stepwise subsequent reduction in SSEP cortical amplitudes not explained by other variables.

THE SEEPAGE CHARACTERISTICS OF HETEROGENEOUS BODY WITH DIFFERENT SPREADING SOLUTION MODES AND ITS APPLICATIONS

As the dump was a typically heterogeneous body, the seepage was different with varied spreading solution modes. The phenomenon of lamination that occured in the site was simulated using three layers in an indoor experiment, and the seepage effect comparison experiment of the inside spreading solution model and the top spreading solution model have been carried out. In the inside spreading solution mode, the phreatic planar flew without infiltration and the parallel layer motion model was used to calculate the seepage coefficient and equivalent seepage coefficient of each state respectively. In the top spreading solution model, the phreatic planar flew with an even infiltration on the surface, and the vertical layer motion model was adopted to calculate the above coefficient. The results showed that the seepage coefficient of the inside model was larger than the top model in the heterogeneous body, The ratio of them was between 1.42 and 3.07. On the basis of these results, the following new technologies were discussed： installing a few small diameter mechanical pore sand piles with every lamination in the using dump; drilling some holes one-off in the unused dump. These two methods could changed the top spreading solution into the inside model, thus the seepage in the dump was improved.

Numerical and Experimental Study on Droplet Spreading Motion after Impingement Considering Dynamic Contact Angle with CCUP （CIP-Combined Unified Procedure） Method

The contact angle is one of important parameters to simulate droplet spreading and impingement phenomena on the surface. In the most numerical research, it is assumed constant value and it is implemented as boundary condition. However, contact angle is changed according to contact line velocity and time. Hence, for accurate simulation, dynamic contact angle which has various values as time elapsed is adopted. In the present study, the numerical analysis is performed on the droplet spreading phenomena considering dynamic contact angle function which is obtained from single droplet spreading experiment on the flat and bare surface. The CIP （cubic interpolated pseudo-particle） method by Yabe is used for analysis of interface between liquid and gas phases. The numerical results considering contact angle function which newly modeled as time and contact angle are compared with numerical results considering Hoffman＇s function and experimental data for range of Weber number which are 4.427 and 11.334. In contrast of numerical result considering Hoffman＇s function, the numerical result shows good agreement with experimental data as time elapsed in contact angle evolution, deformation of droplet spreading radius and height. Indeed, overall, the results display the increasing maximum spreading radius and the decreasing height as Weber numbers increased.

Simulation Research on the Effect of Spreading Process Parameters on the Quality of Lunar Regolith Powder Bed in Additive Manufacturing

Lunar surface additive manufacturing with lunar regolith is a key step in in-situ resource utilization.The powder spreading process is the key process,which has a major impact on the quality of the powder bed and the precision of molded parts.In this study,the discrete element method(DEM)was adopted to simulate the powder spreading process with a roller.The three powder bed quality indicators,including the molding layer offset,voidage fraction,and surface roughness,were established.Besides,the influence of the three process parameters,which are roller’s translational speed,rotational speed,and powder spreading layer thickness on the powder bed quality indicators was also analyzed.The results show that with the reduction of the powder spreading layer thickness and the increase of the rotational speed,the offset increased significantly;when the translational speed increased,the offset first increased and then decreased,which resulted in an extreme value;with the increase of the layer thickness and the decrease of the translational speed,the values for voidage fraction and surface roughness significantly reduced.The powder bed quality indicators were adopted as the optimization objective,and the multi-objective parameter optimization was carried out.The predicted optimal powder spreading parameters and powder bed quality indicators were then obtained.Moreover,the optimal values were then verified.This study can provide informative guidance for in-situ manufacturing at the moon in future deep space exploration missions.

An Important Spreading Event of the Neo-Tethys Ocean during the Late Jurassic and Early Cretaceous: Evidence from Zircon U-Pb SHRIMP Dating on Diabase in Nagarze, Southern Tibet

Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase（gabbro）-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. In order to constrain the emplacement age of these dykes, zircons of two samples from diabases in Nagarzê were dated by using the U-Pb SHRIMP method. Two nearly the same weighted mean ^206pb/^23SU ages were obtained in this paper, which are 134.9±1.8 Ma （MSWD=0.65） and 135.5 ± 2.1 Ma （MSWD=1.40）, respectively. They not only represent the crystallization age of the diabase, but also documented an important spreading event of the Neo-Tethys Ocean during the late Jurassic and early Cretaceous. This dating result is of great significance to reconstruct the temporal framework of the late Neo-Tethys Ocean in the Qinghai-Tibet Plateau.

Lymphatic spreading and lymphadenectomy for esophageal carcinoma

Esophageal carcinoma(EC) is a highly lethal malignancywith a poor prognosis. One of the most important prognostic factors in EC is lymph node status. Therefore, lymphadenectomy has been recognized as a key that influences the outcome of surgical treatment for EC. However, the lymphatic drainage system of the esophagus, including an abundant lymph-capillary network in the lamina propria and muscularis mucosa, is very complex with cervical, mediastinal and celiac node spreading. The extent of lymphadenectomy for EC has always been controversial because of the very complex pattern of lymph node spreading. In this article, published literature regarding lymphatic spreading was reviewed and the current lymphadenectomy trends for EC are discussed.

MUC5AC/β-catenin expression and KRAS gene alteration in laterally spreading colorectal tumors

AIM： To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor （LST）. METHODS： LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes： （1） a granular type （Gr-LST） composed of superficially spread- ing aggregates of nodules forming a fiat-based lesion with a granulonodular and uneven surface; and （2） a non-granular type （NGr-LST） with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC, MUC6, CD10 （markers of gastrointestinal cell lineage）, p53, 13-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog （KRAS） and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 （BRAF） by poly- merase chain reaction followed by direct sequencing. RESULTS： Histologically, 15 Gr-LST samples were ad- enomas with low-grade dysplasia （LGD）, 12 were high- grade dysplasia （HGD） and 9 were adenocarcinomas invading the submucosa （INV）, while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 ex- pression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was signifi- cantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was signifi- cantly higher in the Gr-type harboring a specific muta- tional pattern （G12V）. BRAF mutations （V600E） were detected only in two Gr-LSTs. CONCLUSION： The two subtypes of LST, especially in the proximal colon, have differing phenotypes of gastrointestinal cell lineage, proliferation and activa- tion of Wnt/β-catenin or RAS/RAF/extracellular signal- regulated kinase signaling.

Response of a pile group behind quay wall to liquefaction-induced lateral spreading:a shake-table investigation

The response of pile foundations near a quay wall under liquefaction-induced lateral spreading remains a complex problem. This study presents the results of a shake-table test on a 2×2 pile group behind a sheet-pile quay wall that was subjected to lateral spreading. The quay wall was employed to trigger liquefaction-induced large lateral ground deformation. The discussions focus on the behavior of the pile and the soil and on the bending moment distributions within the group pile and the restoring force characteristics at the superstructure. Overall, the piles exhibited apparent pinning effects that reduced soil deformation. In addition, the rear-row piles near the quay wall experienced larger bending moments than did the front-row piles, indicating significant pile group effects. The tests showed that lateral spreading could be a primary cause of larger monotonic deformations and bending moments. It can also be concluded that the monotonic bending moments were significantly decreased due to the presence of slow soil flow. The stiffness at the superstructure was reduced because of accumulated excess pore pressure before liquefaction, and it was recovered during lateral spreading. The present study further enhances current understanding of the behavior of low-cap pile foundations under lateral spreading.

Fast method for spreading sequence estimation of DSSS signal based on maximum likelihood function

To estimate the spreading sequence of the direct sequence spread spectrum (DSSS) signal, a fast algorithm based on maximum likelihood function is proposed, and the theoretical derivation of the algorithm is provided. By simplifying the objective function of maximum likelihood estimation, the algorithm can realize sequence synchronization and sequence estimation via adaptive iteration and sliding window. Since it avoids the correlation matrix computation, the algorithm significantly reduces the storage requirement and the computation complexity. Simulations show that it is a fast convergent algorithm, and can perform well in low signal to noise ratio (SNR).

A modified stiffness spreading method for layout optimization of truss structures

The stiffness spreading method (SSM) was initially proposed for layout optimization of truss structures,in which an artificial elastic material of low modulus is uniformly distributed in the design domain to create connections between discrete members.In this paper,a modified stiffness spreading method is proposed by replacing the artificial elastic material with auxiliary bars to connect real members of the truss structure.Since the background continuum mesh for the elastic material is no longer required,the computational cost is significantly reduced.Like SSM,the new method is advantageous in that an initial design may consist of disconnected bars allocated in the design domain,and mathematical programming methods can be applied for the efficient solution of the formulated optimization problem.A number of solution strategies are also developed to achieve more practical designs with lower computational cost.Numerical examples of both 2-D and 3-D truss structures are presented to demonstrate the feasibility,robustness and effectiveness of the proposed method.

Performance Evaluation of Space-Time Spreading and Orthogonal Transmit Diversity

Space-time spreading (STS) and orthogonal transmit diversity (OTD) are towtransmit diversity schemes proposed by cdma2000 standard. In this paper, performance comparisonanalysis of the two transmits diversity schemes in multipath channel under multiuser situation arecarried out. Link level simulation in forward link cdma2000 is performed in IMT-2000 channel.Performance analysis and simulation results show that the performance improvement provided STS overOTD decreases as the increase of propagation path number and decrease of the user number.

Effects of structural characterizations on fragility functions of bridges subject to seismic shaking and lateral spreading

This paper evaluates the seismic vulnerability of different classes of typical bridges in California when subjected to seismic shaking or liquefaction-induced lateral spreading. The detailed structural configurations in terms of superstructure type, connection, continuity at support and foundation type, etc. render different damage resistant capability. Six classes of bridges are established based on their anticipated failure mechanisms under earthquake shaking. The numerical models that are capable of simulating the complex soil-structure interaction effects, nonlinear behavior of columns and connections are developed for each bridge class. The dynamic responses are obtained using nonlinear time history analyses for a suite of 250 earthquake motions with increasing intensity. An equivalent static analysis procedure is also implemented to evaluate the vulnerability of the bridges when subjected to liquefaction-induced lateral spreading. Fragility functions for each bridge class are derived and compared for both seismic shaking （based on nonlinear dynamic analyses） and lateral spreading （based on equivalent static analyses） for different performance states. The study finds that the fragility functions due to either ground shaking or lateral spreading show significant correlation with the structural characterizations, but differences emerge for ground shaking and lateral spreading conditions. Structural properties that will mostly affect the bridges＇ damage resistant capacity are also identified.

Seismic phases from the Moho and its implication on the ultraslow spreading ridge

The Moho interface provides critical evidence for crustal thickness and the mode of oceanic crust accretion. The seismic Moho interface has not been identified yet at the magma-rich segments （46°-52°E） of the ultra- slow spreading Southwestern Indian Ridge （SWIR）. This paper firstly deduces the characteristics and do- mains of seismic phases based on a theoretical oceanic crust model. Then, topographic correction is carried out for the OBS record sections along Profile Y3Y4 using the latest OBS data acquired from the detailed 3D seismic survey at the SWIR in 2010. Seismic phases are identified and analyzed, especially for the reflected and refracted seismic phases from the Moho. A 2D crustal model is finally established using the ray tracing and travel-time simulation method. The presence of reflected seismic phases at Segment 28 shows that the crustal rocks have been separated from the mantle by cooling and the Moho interface has already formed at zero age. The 2D seismic velocity structure across the axis of Segment 28 indicates that detachment faults play a key role during the processes of asymmetric oceanic crust accretion.

Simulating the Spreading of Two Competing Public Opinion Information on Complex Network

In this paper, we investigate the regularity of spreading of information and public opinions towards two competing products in complex networks. By building its mathematical model and simulating its evolution process, we have found the statistical regularity for support rates of two different products at a steady stage. The research shows that strength of the public opinion spreading is proportional to the final support rates of a product.

Laterally spreading tumors:Limitations of computed tomography colonography

AIM: To prospectively investigate the detection rate of laterally spreading tumors (LSTs) of the colorectum by computed tomography (CT) colonography (CTC).

Cortical spreading depression-induced preconditioning in the brain

Cortical spreading depression is a technique used to depolarize neurons. During focal or global ischemia, cortical spreading depression-induced preconditioning can enhance tolerance of further injury. However, the underlying mechanism for this phenomenon remains relatively unclear. To date, numerous issues exist regarding the experimental model used to precondition the brain with cortical spreading depression, such as the administration route, concentration of potassium chloride, induction time, duration of the protection provided by the treatment, the regional distribution of the protective effect, and the types of neurons responsible for the greater tolerance. In this review, we focus on the mechanisms underlying cor- tical spreading depression-induced tolerance in the brain, considering excitatory neurotransmission and metabolism, nitric oxide, genomic reprogramming, inflammation, neurotropic factors, and cellular stress response. Specifically, we clarify the procedures and detailed information regarding cortical spreading depression-induced preconditioning and build a foundation for more comprehensive investigations in the field of neural regeneration and clinical application in the future.

Numerical study of three-dimensional wave-induced longshore current's effects on sediment spreading of the Huanghe River mouth

A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED, which has been developed through introducing wave-enhanced bottom shear stress, wave dependent surface drag coefficient, wave-induced surface mixing, SWAN, damping function of sediment on turbulence, sediment model and depth-dependent wave radiation stress to COHERENS. The COHERENS-SED is adopted to study the effects induced by wave-induced three-dimensional longshore current on suspended sediment spreading of the Huanghe River （Yellow River） mouth. Several different cases divided by setting different wave parameters of inputting boundary waves are carried out. The modeling results agree with measurement data. In terms of simulation results, it is easy to know that three-dimensional wave radiation stress plays an obvious role when inputting boundary wave height is stronger than 3 m. Moreover, wave direction also affects the sediment spreading rules of the mouth strongly too.