Developing a context-based bounded centrality approach of street patterns in flooding: a case study of London

Floods affect an average of 21 million people worldwide each year, and their frequency is expected to increase due to climate warming, population growth, and rapid urbanisation. Previous research on the robustness of transport networks during floods has mainly used percolation theory. However, giant component size of disrupted networks cannot capture the entire network’s information and, more importantly, does not reflect the local reality. To address this issue, this study introduces a novel approach to bounded context-based centrality to extract the local impact of disruption. In particular, we propose embedding travel behaviour into the road network to calculate bounded centrality and develop new measures characterising the size of connected components during flooding. Our analysis can identify critical road segments during floods by comparing the decreasing trend and dispersibility of component sizes on road networks. To demonstrate the feasibility of these approaches, a case study of London's transport infrastructure that integrates road networks with relevant urban contexts was developed. This approach is beneficial for practical risk management, helping decision-makers allocate resources efficiently in space and time

Investigation of Cutting Rock by TBM Hob using a SPG Method

TBM (tunnel boring machine) hob is the core component of the TBM for rock cutting, whose cutting performance can directly determine the overall tunneling efficiency of the TBM. The understanding of cutting rock caused by TBM hobs is still not enough due to the complex contact features between the TBM hob and rock. To study the dynamic cutting process of the TBM hobs deeply, the rock cutting numerical model of the TBM hob is built based on the SPG (smooth particle Galerkin) method, the influence of hob penetration and hob spacing on rock breaking dynamic process, rock cutting forces and specific energy consumption are investigated. The results indicate that the dynamic process of sequential cutting of TBM hobs can be simulated well, and the rock breaking patterns caused by TBM hobs can be reflected with the SPG method. It also shows that the cutting forces of the hob are positively correlated with the hob penetration and hob spacing. For a given hob penetration, there exists an optimum hob spacing to acquire the highest rock cutting efficiency. The hob penetrations of 5, 7, 9, and 11 mm correspond to the optimum hob spacing of 60, 80, 90, and 100 mm respectively. Finally, the simulated results based on the SPG method are verified by comparing the experimental results and the CSM model. This study can provide a new method for simulating the rock cutting dynamic process of the TBM hobs

Bridge helix bending promotes RNA polymerase II backtracking through a critical and conserved threonine residue.

The dynamics of the RNA polymerase II (Pol II) backtracking process is poorly understood. We built a Markov State Model from extensive molecular dynamics simulations to identify metastable intermediate states and the dynamics of backtracking at atomistic detail. Our results reveal that Pol II backtracking occurs in a stepwise mode where two intermediate states are involved. We find that the continuous bending motion of the Bridge helix (BH) serves as a critical checkpoint, using the highly conserved BH residue T831 as a sensing probe for the 3'-terminal base paring of RNA:DNA hybrid. If the base pair is mismatched, BH bending can promote the RNA 3'-end nucleotide into a frayed state that further leads to the backtracked state. These computational observations are validated by site-directed mutagenesis and transcript cleavage assays, and provide insights into the key factors that regulate the preferences of the backward translocation

Cutting Characteristics and Layout of Pre-cutting Machine Cutter

The pre-cutting machine is becoming valued due to its ability to effectively prevent surface settlement and reduce vibration in tunnel construction. To obtain the cutting characteristics and layout of pre-cutting machine cutter, the cutting tests by the pre-cutting machine cutter are conducted and the cutting laws are also studied. The research results show that the cutting force rather than normal force and side force is responsible for the rock breaking. With the increase of the cutting depth and cutting spacing, the cutting forces increase generally. But for the little value of cutting spacing, the cutting force can not increase continuously when the cutting depth increase to a relatively large value. Furthermore, for a given cutting depth, the cutting force will keep at an approximate constant rather than continuous increase with the increase of the cutting spacing when the cutting spacing increases to a relatively large value. The specific energy decreases nonlinearly with the increase of cutting depth and the decrease of specific energy is not significant when the cutting depth is more than 12 mm. Moreover, there exists an optimal cutting spacing for a given cutting depth. To maintain a desirable cutting efficiency, the ratio of cutting spacing to cutting depth should be controlled between 1 and 2. Finally, the layout plan of the pre-cutting machine cutter is proposed based on the research results and is applied in the actual manufacturing of the pre-cutting machine

How Resonance Modulates Multiple Hydrogen Bonding in Self-Assembled Systems.

The secondary electrostatic interaction (SEI) has been regarded as the fundamental cause for the relative strengths of multiple hydrogen bonds for decades, though recent studies challenged its validation. Here, we used our developed block-localized wave function (BLW) method, which is a variant of ab initio valence bond (VB) theory and can self-consistently derive the wave function for a strictly electron-localized state, to study a series of exemplary multiply hydrogen-bonded complexes and critically examine the role of SEI in the binding. Our computations show that the multiple hydrogen bond in self-assembled complexes is a kind of resonance-assisted hydrogen bond (RAHB) in nature, and the π resonance which moves electron density from the hydrogen bond donor to the acceptor is the true origin of the different hydrogen bond strengths. By quenching the π resonance effect, the hydrogen bond strengths become nearly identical for various neutral doubly, triply, and quadruply hydrogen-bonded dimers where in general the SEI model works. In other words, the SEI plays only a minor role in multiply hydrogen-bonded complexes, and the π resonance, which changes not only electron densities but also molecular polarities (dipole moments), is the major force

Sandpile-simulation-based graph data model for MVD generative design of shield tunnel lining using information entropy

BIM standard development is central to the performance and behavior of BIM model application across transmission, visualization, and information management perspectives. Tremendous effort has been made to ease the implementation of IFC data model in practice. Yet, the complexity of IFC data model hurdles the implementation of the import and export functionality by software vendors. To overcome this, buildingSMART introduced the concept of Model View Definitions to define which parts of an IFC data model need to be implemented for a specific data exchange scenario. With such, the certification of compatibility for software products with the IFC standard is formed. The Model View Definition is use case orientated to determine whether the specific information should be included in an IFC partial model. With the creation of ad-hoc, project-specific Exchange Requirements increasing, associated MVD development requires much more work to incorporate standard development. To resolve this issue, this paper attempts to exploit the potential of information entropy which has proven itself extremely crucial in many other industries in terms of information management, and then integrates it with sandpile simulation to propose a Top-down hierarchy to structure as well as interpret IFC partial model via Model View Definition. The proposed information entropy shifted MVD development approach would manage to unify the MVD development process that enables the reduction on confusion for various end users, specific organization, or project needs. Moreover, to better translate the BIM standard topology into sandpile simulations, a new notion system is proposed. Sandpile simulations are further implemented to prove their applicability, during the simulation, self-organized criticality is identified, and the existence of chaos is observed

Association between gut microbiota and bone metabolism: Insights from bibliometric analysis

Gut microbiota has been reported to participate in bone metabolism. However, no article has quantitatively and qualitatively analyzed this crossing field. The present study aims to analyze the current international research trends and demonstrate possible hotspots in the recent decade through bibliometrics. We screened out 938 articles meeting the standards from 2001 to 2021 in the Web of Science Core Collection database. Bibliometric analyses were performed and visualized using Excel, Citespace, and VOSviewer. Generally, the annual number of published literatures in this field shows an escalating trend. The United States has the largest number of publications, accounting for 30.4% of the total. Michigan State University and Sichuan University have the largest number of publications, while Michigan State University has the highest average number of citations at 60.00. Nutrients published 49 articles, ranking first, while the Journal of Bone and Mineral Research had the highest average number of citations at 13.36. Narayanan Parameswaran from Michigan State University, Roberto Pacifici from Emory University, and Christopher Hernandez from Cornell University were the three professors who made the largest contribution to this field. Frequency analysis showed that inflammation (148), obesity (86), and probiotics (81) are keywords with the highest focus. Moreover, keywords cluster analysis and keywords burst analysis showed that “inflammation”, “obesity”, and “probiotics” were the most researched topics in the field of gut microbiota and bone metabolism. Scientific publications related to gut microbiota and bone metabolism have continuously risen from 2001 to 2021. The underlying mechanism has been widely studied in the past few years, and factors affecting the alterations of the gut microbiota, as well as probiotic treatment, are emerging as new research trends

Pathological Ace2-to-Ace enzyme switch in the stressed heart is transcriptionally controlled by the endothelial Brg1–FoxM1 complex

Genes encoding angiotensin-converting enzymes (Ace and Ace2) are essential for heart function regulation. Cardiac stress enhances Ace, but suppresses Ace2, expression in the heart, leading to a net production of angiotensin II that promotes cardiac hypertrophy and fibrosis. The regulatory mechanism that underlies the Ace2-to-Ace pathological switch, however, is unknown. Here we report that the Brahma-related gene-1 (Brg1) chromatin remodeler and forkhead box M1 (FoxM1) transcription factor cooperate within cardiac (coronary) endothelial cells of pathologically stressed hearts to trigger the Ace2-to-Ace enzyme switch, angiotensin I-to-II conversion, and cardiac hypertrophy. In mice, cardiac stress activates the expression of Brg1 and FoxM1 in endothelial cells. Once activated, Brg1 and FoxM1 form a protein complex on Ace and Ace2 promoters to concurrently activate Ace and repress Ace2, tipping the balance to Ace2 expression with enhanced angiotensin II production, leading to cardiac hypertrophy and fibrosis. Disruption of endothelial Brg1 or FoxM1 or chemical inhibition of FoxM1 abolishes the stress-induced Ace2-to-Ace switch and protects the heart from pathological hypertrophy. In human hypertrophic hearts, BRG1 and FOXM1 expression is also activated in endothelial cells; their expression levels correlate strongly with the ACE/ACE2 ratio, suggesting a conserved mechanism. Our studies demonstrate a molecular interaction of Brg1 and FoxM1 and an endothelial mechanism of modulating Ace/Ace2 ratio for heart failure therapy