Duration-adaptive Video Highlight Pre-caching for Vehicular Communication Network

Video traffic in vehicular communication networks (VCNs) faces exponential growth. However, different segments of most videos reveal various attractiveness for viewers, and the pre-caching decision is greatly affected by the dynamic service duration that edge nodes can provide services for mobile vehicles driving along a road. In this paper, we propose an efficient video highlight pre-caching scheme in the vehicular communication network, adapting to the service duration. Specifically, a highlight entropy model is devised with the consideration of the segments' popularity and continuity between segments within a period of time, based on which, an optimization problem of video highlight pre-caching is formulated. As this problem is non-convex and lacks a closed-form expression of the objective function, we decouple multiple variables by deriving candidate highlight segmentations of videos through wavelet transform, which can significantly reduce the complexity of highlight pre-caching. Then the problem is solved iteratively by a highlight-direction trimming algorithm, which is proven to be locally optimal. Simulation results based on real-world video datasets demonstrate significant improvement in highlight entropy and jitter compared to benchmark schemes

Switching and Emergence of CTL Epitopes in HIV-1 Infection

Background Human Leukocyte Antigen (HLA) class I restricted Cytotoxic T Lymphocytes (CTLs) exert substantial evolutionary pressure on HIV-1, as evidenced by the reproducible selection of HLA-restricted immune escape mutations in the viral genome. An escape mutation from tyrosine to phenylalanine at the 135th amino acid (Y135F) of the HIV-1 nef gene is frequently observed in patients with HLA-A*24:02, an HLA Class I allele expressed in ~70% of Japanese persons. The selection of CTL escape mutations could theoretically result in the de novo creation of novel epitopes, however, the extent to which such dynamic “CTL epitope switching” occurs in HIV-1 remains incompletely known. Results Two overlapping epitopes in HIV-1 nef, Nef126-10 and Nef134-10, elicit the most frequent CTL responses restricted by HLA-A*24:02. Thirty-five of 46 (76%) HLA-A*24:02-positive patients harbored the Y135F mutation in their plasma HIV-1 RNA. Nef codon 135 plays a crucial role in both epitopes, as it represents the C-terminal anchor for Nef126-10 and the N-terminal anchor for Nef134-10. While the majority of patients with 135F exhibited CTL responses to Nef126-10, none harboring the “wild-type” (global HIV-1 subtype B consensus) Y135 did so, suggesting that Nef126-10 is not efficiently presented in persons harboring Y135. Consistent with this, peptide binding and limiting dilution experiments confirmed F, but not Y, as a suitable C-terminal anchor for HLA-A*24:02. Moreover, experiments utilizing antigen specific CTL clones to recognize endogenously-expressed peptides with or without Y135F indicated that this mutation disrupted the antigen expression of Nef134-10. Critically, the selection of Y135F also launched the expression of Nef126-10, indicating that the latter epitope is created as a result of escape within the former. Conclusions Our data represent the first example of the de novo creation of a novel overlapping CTL epitope as a direct result of HLA-driven immune escape in a neighboring epitope. The robust targeting of Nef126-10 following transmission (or in vivo selection) of HIV-1 containing Y135F may explain in part the previously reported stable plasma viral loads over time in the Japanese population, despite the high prevalence of both HLA-A*24:02 and Nef-Y135F in circulating HIV-1 sequences

Severity of enterovirus A71 infection in a human SCARB2 knock-in mouse model is dependent on infectious strain and route

Enterovirus A71 (EV-A71) is a major etiological agent of human hand, foot and mouth disease, and it can cause severe neurological complications. Although several genotypes of EV-A71 strains are prevalent in different regions of the world, the genotype C4 has circulated in mainland China for more than 20 years. The pathogenicity of different EV-A71 clinical isolates varies and needs to be explored. In this study, hSCARB2 knock-in mice (N = 181) with a wide range of ages were tested for their susceptibility to two EV-A71 strains with the subgenotypes C4 and C2, and two infection routes (intracranial and venous) were compared. The clinical manifestations and pathology and their relationship to the measured viral loads in different tissues were monitored. We observed that 3 weeks is a crucial age, as mice younger than 3-week-old that were infected became extremely ill. However, mice older than 3 weeks displayed diverse clinical symptoms. Significant differences were observed in the pathogenicity of the two strains with respect to clinical signs, disease incidence, survival rate, and body weight change. We concluded that hSCARB2 knock-in mice are a sensitive model for investigating the clinical outcomes resulting from infection by different EV-A71 strains. The intracranial infection model appears to be suitable for evaluating EV-A71 neurovirulence, whereas the venous infection model is appropriate for studying the pathogenicity of EV-A71

Experimental Studies of Scale Effect on the Shear Strength of Coarse-Grained Soil

Shear strength is an essential index for the evaluation of soil stability. Test results of the shear strength of scaled coarse-grained soil (CGS for short) are usually not able to accurately reflect the actual properties and behaviors of in situ CGS due to the scale effect. Therefore, this study focuses on the influence of the scale effect on the shear strength of scaled CGS, which has an important theoretical significance and application for the strength estimation of CGS in high earth-rock dam engineering. According to previous studies, the main cause of the scale effect for scaled CGS is the variation of the gradation structure as well as the maximum particle size (dmax), in which the gradation structure as a characteristic parameter can be expressed by the gradation area (S). A total of 24 groups of test soil samples with different gradations were designed by changing the maximum particle size dmax and gradation area S. Direct shear tests were conducted in this study to quantitatively explore the effect of the gradation structure and the maximum particle size on the shear strength of CGS. Test results suggest that the shear strength indexes (i.e., the cohesion and internal friction angle) of CGS present an increasing trend with the improvement of the maximum particle size dmax, and thus a logarithmic function relationship among c, φ, and dmax is presented. Both cohesion (c) and internal friction angle (φ) are negatively related to the gradation area (S) in most cases. As a result, an empirical relationship between c, φ, and S is established based on the test results. Furthermore, a new prediction model of shear strength of CGS considering the scale effect is proposed, and the accuracy of this model is verified through the test results provided by relevant literature. Finally, the applicability of this model to different types of CGS is discussed

Emerging role of mesenchymal stromal cells in gynecologic cancer therapy

Abstract Mesenchymal stromal cells (MSCs) show considerable promise in regenerative medicine with superior anti-fibrotic, immunomodulatory, and angiogenic functions. More recently, discovered with the tumor tropism, MSCs have been exploited as the basis of targeted cancer therapy. In this scenario, MSCs can directly home to tumor tissues and play anti-tumor properties. In addition, MSCs, MSC-derived exosomes and MSC-derived membranes are often developed as carriers for precisely delivering cytotoxic agents to cancer sites, including chemotherapeutic drugs, therapeutic genes, or oncolytic viruses. However, it has revealed the tumorigenic risk of MSCs as an important component within the tumor microenvironment, hampering the translation of MSC-based cancer therapies into clinical settings. Therefore, in this review, we introduce the specific tumor-tropic ability of MSCs and underlying mechanisms. We also summarize the current application of MSC-based therapeutic approaches in treating gynecologic cancers, mainly including cervical, ovarian, and endometrial cancers. Moreover, we discuss the main challenges that the current MSC-based cancer therapies are facing

Evaluating the Effects of MKAVCFSL Derived from Bighead Carp (Hypophthalmichthys nobilis) Flesh on Antioxidant Activity in Caco-2 Cells In Vitro

The effect of an antioxidative peptide Met-Lys-Ala-Val-Cys-Phe-Ser-Leu (MKAVCFSL) on oxidative stress in Caco-2 cell lines was investigated. Caco-2 cells exposed to excess oxidative stress could be restored when pretreated with the peptide. Reactive oxygen species (ROS) and malondialdehyde (MDA) within the cells could be scavenged by MKAVCFSL. The peptide could also enhance the activity of glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD), while catalase (CAT) activity did not show a significant difference between treatment and control samples. Meanwhile, it was observed that peptide treatment increased the concentration of glutathione (GSH). Yet the content of glutathione disulfide (GSSG) was hardly affected. The stability of MKAVCFSL was also assessed and an intact peptide was observed after simulated gastrointestinal digestion. Part of the peptide was hydrolyzed into fragments including MKA, FSL, AVCFSL, and MKAVCF. This study demonstrated that MKAVCFSL derived from bighead carp hydrolysates could ameliorate oxidative stress to protect the Caco-2 cells

Pushing toward a more personalized MOOC: Exploring instructor selected activities, resources, and technologies for MOOC design and implementation

This study explores the activities, tools, and resources that instructors of massive open online courses (MOOCs) use to improve the personalization of their MOOCs. Following email interviews with 25 MOOC and open education leaders regarding MOOC personalization, a questionnaire was developed. This questionnaire was then completed by 152 MOOC instructors from around the world. While more than 8 in 10 respondents claimed heavy involvement in designing their MOOCs, only one-third placed extensive effort on meeting unique learner needs during course design, and even fewer respondents were concerned with personalization during course delivery. An array of instructional practices, technology tools, and content resources were leveraged by instructors to personalize MOOC-based learning environments. Aligning with previous research, the chief resources and tools employed in their MOOCs were discussion forums, video lectures, supplemental readings, and practice quizzes. In addition, self-monitoring and peer-based methods of learner feedback were more common than instructor monitoring and feedback. Some respondents mentioned the use of flexible deadlines, proposed alternatives to course assignments, and introduced multimedia elements, mobile applications, and guest speakers among the ways in which they attempted to personalize their massive courses. A majority of the respondents reported modest or high interest in learning new techniques to personalize their next MOOC offering

Agarose gel etectrophoresis of DNA from HeLa cells treated for 48 hours with different concentrations of EPSAH.

<p>Agarose gel etectrophoresis of DNA from HeLa cells treated for 48 hours with different concentrations of EPSAH.</p

Identification of apoptotic cells by AO/EB staining.

<p>HeLa cells were treated with different concentrations of EPSAH (50–800 µg/ml) for 48 h and compared with untreated cells. The most representative fields are shown.</p