Second-order accurate genuine BGK schemes for the ultra-relativistic flow simulations

This paper presents second-order accurate genuine BGK (Bhatnagar-Gross-Krook) schemes in the framework of finite volume method for the ultra-relativistic flows. Different from the existing kinetic flux-vector splitting (KFVS) or BGK-type schemes for the ultra-relativistic Euler equations, the present genuine BGK schemes are derived from the analytical solution of the Anderson-Witting model, which is given for the first time and includes the "genuine" particle collisions in the gas transport process. The BGK schemes for the ultra-relativistic viscous flows are also developed and two examples of ultra-relativistic viscous flow are designed. Several 1D and 2D numerical experiments are conducted to demonstrate that the proposed BGK schemes not only are accurate and stable in simulating ultra-relativistic inviscid and viscous flows, but also have higher resolution at the contact discontinuity than the KFVS or BGK-type schemes.Comment: 41 pages, 13 figure

Effective noninvasive zygosity determination by maternal plasma target region sequencing

Background: Currently very few noninvasive molecular genetic approaches are available to determine zygosity for twin pregnancies in clinical laboratories. This study aimed to develop a novel method to determine zygosity by using maternal plasma target region sequencing. Methods: We constructed a statistic model to calculate the possibility of each zygosity type using likelihood ratios (Li) and empirical dynamic thresholds targeting at 4,524 single nucleotide polymorphisms (SNPs) loci on 22 autosomes. Then two dizygotic (DZ) twin pregnancies, two monozygotic (MZ) twin pregnancies and two singletons were recruited to evaluate the performance of our novel method. Finally we estimated the sensitivity and specificity of the model in silico under different cell-free fetal DNA (cff-DNA) concentration and sequence depth. Results/Conclusions: We obtained 8.90 Gbp sequencing data on average for six clinical samples. Two samples were classified as DZ with L values of 1.891 and 1.554, higher than the dynamic DZ cut-off values of 1.162 and 1.172, respectively. Another two samples were judged as MZ with 0.763 and 0.784 of L values, lower than the MZ cut-off values of 0.903 and 0.918. And the rest two singleton samples were regarded as MZ twins, with L values of 0.639 and 0.757, lower than the MZ cut-off values of 0.921 and 0.799. In silico, the estimated sensitivity of our noninvasive zygosity determination was 99.90% under 10% total cff-DNA concentration with 2 Gbp sequence data. As the cff-DNA concentration increased to 15%, the specificity was as high as 97% with 3.50 Gbp sequence data, much higher than 80% with 10% cff-DNA concentration. Significance: This study presents the feasibility to noninvasively determine zygosity of twin pregnancy using target region sequencing, and illustrates the sensitivity and specificity under various detecting condition. Our method can act as an alternative approach for zygosity determination of twin pregnancies in clinical practice.Multidisciplinary SciencesSCI(E)2ARTICLE6null

eHAPAC: A Privacy-Supported Access Control Model for IP-Enabled Wireless Sensor Networks

The implementation of IP technology in wireless sensor networks has promoted the development of many smart scenarios. To enhance secure access in IP-enabled wireless sensor networks, access control to sensor nodes is a necessary process. However, access control currently faces two challenges, feasibility and preservation of user access privacy. In this paper, we propose eHAPAC, a novel privacy-preserving access control model for IP-enabled wireless sensor networks. The contributions of our paper include three parts. First, this paper integrates the Hidra access control protocol and APAC privacy-preserving model, addressing the issue of privacy-preserving access control in resource-constrained devices. Second, this paper proposes an enhanced Hidra protocol to implement the unlinkability of protocol message exchanges. Third, to solve the problem of third party credibility, this paper improves the group signature-based APAC model and utilizes blockchain technology to manage the storage and publication of public group signature keys. Security analysis and performance evaluation prove that our protocol is secure and effective

The role of vasoactive intestinal peptide (VIP) in atropine-related inhibition of the progression of myopia

Abstract Objective This study aimed to investigate the potential involvement of vasoactive intestinal polypeptide (VIP) in myopia development and its contribution to the mechanism of action of the anti-myopia drug, atropine. Methods Thirty-three-week-old guinea pigs were randomly divided into normal control (NC, n = 10), monocularly form-deprived (FDM, n = 10), and FDM treated with 1% atropine (FDM + AT, n = 10) groups. The diopter and axial length were measured at 0, 2, and 4 weeks. Guinea pig eyeballs were removed at week four, fixed, and stained for morphological changes. Immunohistochemistry (IHC) and in situ hybridization (ISH) were performed to evaluate VIP protein and mRNA levels. Results The FDM group showed an apparent myopic shift compared to the control group. The results of the H&E staining were as follows: the cells of the inner/outer nuclear layers and retinal ganglion cells were disorganized; the choroidal thickness (ChT), blood vessel lumen, and area were decreased; the sclera was thinner, with disordered fibers and increased interfibrillar space. IHC and ISH revealed that VIP's mRNA and protein expressions were significantly up-regulated in the retina of the FDM group. Atropine treatment attenuated FDM-induced myopic shift and fundus changes, considerably reducing VIP's mRNA and protein expressions. Conclusions The findings of elevated VIP mRNA and protein levels observed in the FDM group indicate the potential involvement of VIP in the pathogenesis and progression of myopia. The ability of atropine to reduce this phenomenon suggests that this may be one of the molecular mechanisms for atropine to control myopia