Modelling and upscaling of shallow compaction in basins

Heterogeneous fine-grained sediments at shallow burial (< 1000m) below the seafloor can often experience large strain of mechanical compaction and variable degrees of overpressure in their pore space as a result of disequilibrium dissipation of pore fluid. Shallow overpressure can pose significant risks to economics and safety of hydrocarbon production and may impact on hydrocarbon generation deep in a basin and hydrocarbon migration to traps during basin evolution. However, when basin modelling ignores the heterogeneity of sediments, large strain deformation and fluid flow conditions at smaller length- and/or time-scales than those at basin scales, it can lead to incorrect prediction of sediment compaction, and hence the mass of the sediment column, the magnitude of pore pressure and its distribution at shallow burials, and consequently can impact on the simulation of basin evolution. In this thesis, the necessity of considering large-strain consolidation in modelling shallow compaction is demonstrated, and a one-dimensional large-strain numerical simulator, based on one of Gibson’s consolidation models and suitable for basin modelling, is developed and verified. An analytical upscaling technique is also developed for determining the effective compressible parameters and permeability for horizontally layered systems of certain compaction characteristics. They are used subsequently to analyse parametrically the compaction behaviours of the layered systems and to calculate effective coefficients for the systems, with results showing that fine-scale simulation is required when considering the effect of fluid-structure interaction. However, the large strain model over-predicts the pressure of the Ursa region, Gulf of Mexico, based on information from the Integrated Ocean Drilling Program (IODP). An analysis indicates that horizontal fluid flow, or lateral motion of mass transport processes, may explain the over prediction. The limitation of a 1D model is further discussed thereafter both in fluid flow and mechanical deformation. With strong applicability and fundamentality, the Modified Cam Clay model is adopted in 2D research, and related verification is provided. Modified Cam Clay can show elastic and elastic-plastic properties in basin evolution. Heterogeneous Modified Cam Clay materials can be upscaled to a homogenous anisotropic elastic material in elastic deformation and a homogenous Modified Cam Clay material in elastic-plastic deformation, however, the upscaled parameters vary with the effective stress. The value of the upscaling is demonstrated by modelling the evolution of a simplified North Africa basin model

Zaozao Xu’s case: Chinese women’s appeal for the right to freeze their eggs

China’s regulatory framework on assisted reproductive technologies (henceforth ARTs) has remained unchanged and unchallenged for over two decades, prohibiting unmarried women from accessing any form of ARTs. Section 1 Article 4(1) of the Ethical Principles for Human Reproductive Technologies and Human Sperm Banks explicitly stipulates that ‘couples who do not comply with national population and family planning laws and regulations and single women’ are prohibited from accessing ARTs. However, unmarried men are allowed to freeze sperm regardless of their marital status, constituting direct discrimination against women. Furthermore, significant legislative conflicts exist between local regulations and departmental rules in this area, hindering the consistent application of ART norms in China and substantially limiting the reproductive rights of Chinese women. Zaozao Xu’s case is the first case in China directly challenging the current prohibitive regulations on egg freezing and may signify a crucial turning point in China’s reform of ARTs legislation. This commentary provides an overview of the case and examines various issues associated with the existing regulatory framework, including the vagueness of the legislation and regulation, legislative conflicts in the current framework, deeply rooted discrimination against women, and the regulator’s problematic conception of ARTs. This commentary emphasises the urgent need for China to re-evaluate and reform its ARTs regulatory framework to allow unmarried women to access ARTs, or at least egg-freezing services as the first step

In situ structures of the segmented genome and RNA polymerase complex inside a dsRNA virus.

Viruses in the Reoviridae, like the triple-shelled human rotavirus and the single-shelled insect cytoplasmic polyhedrosis virus (CPV), all package a genome of segmented double-stranded RNAs (dsRNAs) inside the viral capsid and carry out endogenous messenger RNA synthesis through a transcriptional enzyme complex (TEC). By direct electron-counting cryoelectron microscopy and asymmetric reconstruction, we have determined the organization of the dsRNA genome inside quiescent CPV (q-CPV) and the in situ atomic structures of TEC within CPV in both quiescent and transcribing (t-CPV) states. We show that the ten segmented dsRNAs in CPV are organized with ten TECs in a specific, non-symmetric manner, with each dsRNA segment attached directly to a TEC. The TEC consists of two extensively interacting subunits: an RNA-dependent RNA polymerase (RdRP) and an NTPase VP4. We find that the bracelet domain of RdRP undergoes marked conformational change when q-CPV is converted to t-CPV, leading to formation of the RNA template entry channel and access to the polymerase active site. An amino-terminal helix from each of two subunits of the capsid shell protein (CSP) interacts with VP4 and RdRP. These findings establish the link between sensing of environmental cues by the external proteins and activation of endogenous RNA transcription by the TEC inside the virus

Hard Label Black Box Node Injection Attack on Graph Neural Networks

While graph neural networks have achieved state-of-the-art performances in many real-world tasks including graph classification and node classification, recent works have demonstrated they are also extremely vulnerable to adversarial attacks. Most previous works have focused on attacking node classification networks under impractical white-box scenarios. In this work, we will propose a non-targeted Hard Label Black Box Node Injection Attack on Graph Neural Networks, which to the best of our knowledge, is the first of its kind. Under this setting, more real world tasks can be studied because our attack assumes no prior knowledge about (1): the model architecture of the GNN we are attacking; (2): the model's gradients; (3): the output logits of the target GNN model. Our attack is based on an existing edge perturbation attack, from which we restrict the optimization process to formulate a node injection attack. In the work, we will evaluate the performance of the attack using three datasets, COIL-DEL, IMDB-BINARY, and NCI1

Alchemical and structural distribution based representation for improved QML

We introduce a representation of any atom in any chemical environment for the generation of efficient quantum machine learning (QML) models of common electronic ground-state properties. The representation is based on scaled distribution functions explicitly accounting for elemental and structural degrees of freedom. Resulting QML models afford very favorable learning curves for properties of out-of-sample systems including organic molecules, non-covalently bonded protein side-chains, (H$_2$O)$_{40}$-clusters, as well as diverse crystals. The elemental components help to lower the learning curves, and, through interpolation across the periodic table, even enable "alchemical extrapolation" to covalent bonding between elements not part of training, as evinced for single, double, and triple bonds among main-group elements

ProcData: An R Package for Process Data Analysis

Process data refer to data recorded in the log files of computer-based items. These data, represented as timestamped action sequences, keep track of respondents' response processes of solving the items. Process data analysis aims at enhancing educational assessment accuracy and serving other assessment purposes by utilizing the rich information contained in response processes. The R package ProcData presented in this article is designed to provide tools for processing, describing, and analyzing process data. We define an S3 class "proc" for organizing process data and extend generic methods summary and print for class "proc". Two feature extraction methods for process data are implemented in the package for compressing information in the irregular response processes into regular numeric vectors. ProcData also provides functions for fitting and making predictions from a neural-network-based sequence model. These functions call relevant functions in package keras for constructing and training neural networks. In addition, several response process generators and a real dataset of response processes of the climate control item in the 2012 Programme for International Student Assessment are included in the package

Effect of Two Kinds of Bone Replacement Materials on Bone Formation in Repairing Bone Defects Around Mandibular Posterior Area: a Case Study of Bone Defects Around Mandibular Posterior Area Caused by Boxing

Objective: To investigate the effect of two kinds of bone replacement materials on bone formation in repairing bone defect around mandibular posterior area. Methods: A total of 60 patients with Bone defects around mandibular posterior area caused by boxing were selected from a hospital from January 2020 to June 2020. They were divided into Perio Glas (group P) and Bone Plant (group B) by random number table method, with 30 patients in each group. Perio Glas Bone graft was used in group P and Bone Plant graft was used in group B. The vertical height and buccal lingual bone plate width of the two groups were observed at baseline and after treatment, and the success rate of implants was compared between the two groups. Results: The success rate of implant in group P was significantly lower than that in group B (P &lt; 0.05). The vertical height and buccal lingual bone plate width in group P were significantly lower than those in group B (P &lt; 0.05). Conclusion: Compared with Perio Glas, Bone Plant can better maintain the vertical height and buccal lingual Bone plate width of patients with Bone defects around mandibular posterior area caused by boxing, and has better effect of inducing Bone regeneration and osteogenesis

Application of Nanotechnology in Oral Implantation Based on Exercise-Induced Tooth Injury

With the development of sports in various countries, more and more people participate in sports, and the rate of sports injuries to the oral and maxillofacial system also increases, especially the dental injuries caused by boxing are more common. At the same time, with the improvement of modern production, people's basic needs have been continuously met, and more and more people have begun to pay attention to their physical health and appearance characteristics. Among them, dental plastic correction and restoration have received great attention. In addition, with the application of nanotechnology in various fields in recent years, scholars at home and abroad have also tried or have continued to introduce nanomaterials into oral clinics, in order to improve and develop the application of oral materials, so that the oral clinic can be continuously improved and developed. Therefore, this paper reviews the current situation of sports injury of the oral and maxillofacial system, the mechanical analysis of tooth injury, the current situation of tooth restoration and the application of nanotechnology in the field of oral implantation