Wnt Signaling in Neural Crest Ontogenesis and Oncogenesis.

Neural crest (NC) cells are a temporary population of multipotent stem cells that generate a diverse array of cell types, including craniofacial bone and cartilage, smooth muscle cells, melanocytes, and peripheral neurons and glia during embryonic development. Defective neural crest development can cause severe and common structural birth defects, such as craniofacial anomalies and congenital heart disease. In the early vertebrate embryos, NC cells emerge from the dorsal edge of the neural tube during neurulation and then migrate extensively throughout the anterior-posterior body axis to generate numerous derivatives. Wnt signaling plays essential roles in embryonic development and cancer. This review summarizes current understanding of Wnt signaling in NC cell induction, delamination, migration, multipotency, and fate determination, as well as in NC-derived cancers

Stability and bifurcation analysis of Westwood+ TCP congestion control model in mobile cloud computing networks

In this paper, we first build up a Westwood+ TCP congestion control model with communication delay in mobile cloud computing networks. We then study the dynamics of this model by analyzing the distribution ranges of eigenvalues of its characteristic equation. Taking communication delay as the bifurcation parameter, we derive the linear stability criteria depending on communication delay. Furthermore, we study the direction of Hopf bifurcation as well as the stability of periodic solution for the Westwood+ TCP congestion control model with communication delay. We find that the Hopf bifurcation occurs when the communication delay passes a sequence of critical values. The stability and direction of the Hopf bifurcation are determined by the normal form theory and the center manifold theorem. Finally, numerical simulation is done to verify the theoretical results

Experimental study of supercritical CO2 injected into water saturated medium rank coal by X-ray microCT

Carbon dioxide geosequestration into deep unmineable coal seams is a technique which can mitigate anthropogenic greenhouse gas emissions. However, coal composition is always complex, and some minerals such as calcite chemically react when exposed to the acidic environment (which is created by scCO2 mixing with formation water). These reactive transport processes are still poorly understood. We thus imaged a water-bearing heterogeneous coal (calcite rich) core before and after scCO2 injection in-situ at high resolutions (3.43 µm) in 3D via X-ray in-situ microCT flooding system. Indeed, the calcite-coal mixed layer was partially dissolved, and absolute porosity and connectivity significantly increased. We thus suggested that such process could be used as an acidizing method in CO2 ECBM. However, such dissolved damage also can significantly affect the rock mechanical properties and potentially induce geohazards

Analysis of internal crack healing mechanism under rolling deformation

A new experimental method, called the \u27hole filling method\u27, is proposed to simulate the healing of internal cracks in rolled workpieces. Based on the experimental results, the evolution in the microstructure, in terms of diffusion, nucleation and recrystallisation were used to analyze the crack healing mechanism. We also validated the phenomenon of segmented healing. Internal crack healing involves plastic deformation, heat transfer and an increase in the free energy introduced by the cracks. It is proposed that internal cracks heal better under high plastic deformation followed by slow cooling after rolling. Crack healing is controlled by diffusion of atoms from the matrix to the crack surface, and also by the nucleation and growth of ferrite grain on the crack surface. The diffusion mechanism is used to explain the source of material needed for crack healing. The recrystallisation mechanism is used to explain grain nucleation and growth, accompanied by atomic migration to the crack surface

Adaptive Constraint Partition based Optimization Framework for Large-scale Integer Linear Programming(Student Abstract)

Integer programming problems (IPs) are challenging to be solved efficiently due to the NP-hardness, especially for large-scale IPs. To solve this type of IPs, Large neighborhood search (LNS) uses an initial feasible solution and iteratively improves it by searching a large neighborhood around the current solution. However, LNS easily steps into local optima and ignores the correlation between variables to be optimized, leading to compromised performance. This paper presents a general adaptive constraint partition-based optimization framework (ACP) for large-scale IPs that can efficiently use any existing optimization solver as a subroutine. Specifically, ACP first randomly partitions the constraints into blocks, where the number of blocks is adaptively adjusted to avoid local optima. Then, ACP uses a subroutine solver to optimize the decision variables in a randomly selected block of constraints to enhance the variable correlation. ACP is compared with LNS framework with different subroutine solvers on four IPs and a real-world IP. The experimental results demonstrate that in specified wall-clock time ACP shows better performance than SCIP and Gurobi.Comment: To be published in AAAI2023 Student Abstrac

Comparison of end-to-side versus side-to-side anastomosis in upper limb arteriovenous fistula in hemodialysis patients: A systematic review and meta-analysis

ObjectiveIt is currently unclear if the anastomosis technique impacts the patency of upper arm arteriovenous fistula (AVF) in hemodialysis patients. This review compared outcomes of end-to-side and side-to-side anastomosis for AVF fistula in hemodialysis patients.MethodsPubMed, CENTRAL, Web of Science, and Embase were searched for all types of studies published between 1st January 2000 to 3rd September 2022. Patency rates at 6, 12 months, maturation time, and complications were compared between ETS and STS groups.ResultsSixteen studies including six randomized controlled trials (RCTs) were included. Meta-analysis showed no difference in patency rates between ETS and STS group at 6 months (OR: 1.15 95% CI: 0.72, 1.83 I2 = 52% p = 0.56) but better patency with STS at 12 months (OR: 0.63 95% CI: 0.41, 0.95 I2 = 21% p = 0.03). The difference was non-significant in a subgroup analysis of RCTs and non-RCTs. In the absence of distal vein ligation in the STS group, the ETS group had significantly better patency at 6 months but with distal vein ligation, STS had higher patency at 12 months. Meta-analysis demonstrated no difference in maturation time between the two groups (MD: 0.10 95% CI: 0.29, 0.49 I2 = 89% p = 0.61). Only a descriptive analysis of complications could be carried out with no major difference.ConclusionOur review demonstrates that the STS anastomosis technique with distal vein ligation may result in significantly better patency rates as compared to the standard ETS technique. Data for complication rates are scarce and varied but without any significant differences between the two techniques