Metaverse Security and Privacy: An Overview

Metaverse is a living space and cyberspace that realizes the process of virtualizing and digitizing the real world. It integrates a plethora of existing technologies with the goal of being able to map the real world, even beyond the real world. Metaverse has a bright future and is expected to have many applications in various scenarios. The support of the Metaverse is based on numerous related technologies becoming mature. Hence, there is no doubt that the security risks of the development of the Metaverse may be more prominent and more complex. We present some Metaverse-related technologies and some potential security and privacy issues in the Metaverse. We present current solutions for Metaverse security and privacy derived from these technologies. In addition, we also raise some unresolved questions about the potential Metaverse. To summarize, this survey provides an in-depth review of the security and privacy issues raised by key technologies in Metaverse applications. We hope that this survey will provide insightful research directions and prospects for the Metaverse's development, particularly in terms of security and privacy protection in the Metaverse.Comment: IEEE BigData 2022. 10 pages, 2 figure

AI-Generated Content (AIGC): A Survey

To address the challenges of digital intelligence in the digital economy, artificial intelligence-generated content (AIGC) has emerged. AIGC uses artificial intelligence to assist or replace manual content generation by generating content based on user-inputted keywords or requirements. The development of large model algorithms has significantly strengthened the capabilities of AIGC, which makes AIGC products a promising generative tool and adds convenience to our lives. As an upstream technology, AIGC has unlimited potential to support different downstream applications. It is important to analyze AIGC's current capabilities and shortcomings to understand how it can be best utilized in future applications. Therefore, this paper provides an extensive overview of AIGC, covering its definition, essential conditions, cutting-edge capabilities, and advanced features. Moreover, it discusses the benefits of large-scale pre-trained models and the industrial chain of AIGC. Furthermore, the article explores the distinctions between auxiliary generation and automatic generation within AIGC, providing examples of text generation. The paper also examines the potential integration of AIGC with the Metaverse. Lastly, the article highlights existing issues and suggests some future directions for application.Comment: Preprint. 14 figures, 4 table

Genomic analysis and characterization of phages infecting the marine Roseobacter CHAB-I-5 lineage reveal a globally distributed and abundant phage genus

Marine phages play an important role in marine biogeochemical cycles by regulating the death, physiological metabolism, and evolutionary trajectory of bacteria. The Roseobacter group is an abundant and important heterotrophic bacterial group in the ocean, and plays an important role in carbon, nitrogen, sulfur and phosphorus cycling. The CHAB-I-5 lineage is one of the most dominant Roseobacter lineages, but remains largely uncultured. Phages infecting CHAB-I-5 bacteria have not yet been investigated due to the lack of culturable CHAB-I-5 strains. In this study, we isolated and sequenced two new phages (CRP-901 and CRP-902) infecting the CHAB-I-5 strain FZCC0083. We applied metagenomic data mining, comparative genomics, phylogenetic analysis, and metagenomic read-mapping to investigate the diversity, evolution, taxonomy, and biogeography of the phage group represented by the two phages. The two phages are highly similar, with an average nucleotide identity of 89.17%, and sharing 77% of their open reading frames. We identified several genes involved in DNA replication and metabolism, virion structure, DNA packing, and host lysis from their genomes. Metagenomic mining identified 24 metagenomic viral genomes closely related to CRP-901 and CRP-902. Genomic comparison and phylogenetic analysis demonstrated that these phages are distinct from other known viruses, representing a novel genus-level phage group (CRP-901-type). The CRP-901-type phages do not contain DNA primase and DNA polymerase genes, but possess a novel bifunctional DNA primase-polymerase gene with both primase and polymerase activities. Read-mapping analysis showed that the CRP-901-type phages are widespread across the world’s oceans and are most abundant in estuarine and polar waters. Their abundance is generally higher than other known roseophages and even higher than most pelagiphages in the polar region. In summary, this study has greatly expanded our understanding of the genetic diversity, evolution, and distribution of roseophages. Our analysis suggests that the CRP-901-type phage is an important and novel marine phage group that plays important roles in the physiology and ecology of roseobacters

Relationship between the cumulative exposure to atherogenic index of plasma and ischemic stroke: A retrospective cohort study

Background: Atherogenic index of plasma (AIP) has been demonstrated as a surrogate marker for ischemic stroke, but there is limited evidence for the effect of long-term elevation of AIP on ischemic stroke. Therefore, we aimed to characterize the relationship between cumulative exposure to AIP and the risk of ischemic stroke. Methods: A total of 54,123 participants in the Kailuan Study who attended consecutive health examinations in 2006, 2008, and 2010 and had no history of ischemic stroke or cancer were included. The time-weighted cumulative AIP (cumAIP) was calculated as a weighted sum of the mean AIP values for each time interval and then normalized to the total duration of exposure (2006–2010). Participants were divided into four groups according to quartile of cumAIP: the Q1 group, ≤ −0.50; Q2 group, − 0.50 to − 0.12; Q3 group, − 0.12 to 0.28; and Q4 group, ≥ 0.28. Cox proportional hazard models were used to evaluate the relationship between cumAIP and ischemic stroke by calculating hazard ratios (HRs) and 95% confidence intervals (95% CIs). Results: After a median follow-up of 11.03 years, a total of 2,742 new ischemic stroke events occurred. The risk of ischemic stroke increased with increasing quartile of cumAIP. After adjustment for potential confounders, Cox regression models showed that participants in the Q2, Q3, and Q4 groups had significantly higher risks of ischemic stroke than those in the Q1 group. The HRs (95% CIs) for ischemic stroke in the Q2, Q3, and Q4 groups were 1.17 (1.03, 1.32), 1.33 (1.18, 1.50), and 1.45 (1.28, 1.64), respectively. The longer duration of high AIP exposure was significantly associated with increased ischemic stroke risk. Conclusions: High cumulative AIP is associated with a higher risk of ischemic stroke, which implies that the long-term monitoring and maintenance of an appropriate AIP may help prevent such events

Visit-to-visit variability in triglyceride-glucose index and diabetes:A 9-year prospective study in the Kailuan Study

Instruction/Aims: It is unknown whether variability in the triglyceride-glucose index (TyG-index) is associated with the risk of diabetes. Here, we sought to characterize the relationship between TyG-index variability and incident diabetes. Methods: We performed a prospective study of 48,013 participants in the Kailuan Study who did not have diabetes. The TyG-index was calculated as ln [triglyceride (TG, mg/dL) concentration × fasting blood glucose concentration (FBG, mg/dL)/2]. The TyG-index variability was assessed using the standard deviation (SD) of three TyG-index values that were calculated during 2006/07, 2008/09, and 2010/11. We used the Cox proportional hazard models to analyze the effect of TyG-index variability on incident diabetes. Results: A total of 4,055 participants were newly diagnosed with diabetes during the study period of 8.95 years (95% confidence interval (CI) 8.48–9.29 years). After adjustment for confounding factors, participants in the highest and second-highest quartiles had significantly higher risks of new-onset diabetes versus the lowest quartile, with hazard ratios (95% CIs) of 1.18 (1.08–1.29) and 1.13 (1.03–1.24), respectively (P trend< 0.05). These higher risks remained after further adjustment for the baseline TyG-index. Conclusions: A substantial fluctuation in TyG-index is associated with a higher risk of diabetes in the Chinese population, implying that it is important to maintain a normal and consistent TyG-index

Graphene controlled Brewster angle device for ultra broadband terahertz modulation

Terahertz modulators with high tunability of both intensity and phase are essential for effective control of electromagnetic properties. Due to the underlying physics behind existing approaches there is still a lack of broadband devices able to achieve deep modulation. Here, we demonstrate the effect of tunable Brewster angle controlled by graphene, and develop a highly-tunable solid-state graphene/quartz modulator based on this mechanism. The Brewster angle of the device can be tuned by varying the conductivity of the graphene through an electrical gate. In this way, we achieve near perfect intensity modulation with spectrally flat modulation depth of 99.3 to 99.9 percent and phase tunability of up to 140 degree in the frequency range from 0.5 to 1.6 THz. Different from using electromagnetic resonance effects (for example, metamaterials), this principle ensures that our device can operate in ultra-broadband. Thus it is an effective principle for terahertz modulation

Association of Cardiovascular Health Score Trajectory With Incident Myocardial Infarction in Hypertensive Patients

Background: The association between changes in cardiovascular health score (CHS) over time and myocardial infarction (MI) risk in hypertensive patients remains unclear. Method: This was a prospective study comprising 17 374 hypertensive patients from the Kailuan study cohort who underwent 3 surveys and were identified to be free of MI, stroke, or cancer from 2006 to 2010. CHS consisted of 7 cardiovascular health metrics (plasma glucose, total cholesterol, blood pressure, smoking, body mass index, physical activity, salt intake), ranging from 0 (worst) to 13 (best) in the study. CHS trajectories were developed during 2006 to 2010 to predict the MI risk from 2010 to 2020. Additionally, the Cox proportional hazard model was established to calculate the hazard ratio and 95% CI of incident MI in different trajectory groups. Result: This study identified the 5 CHS trajectories from 2006 to 2010: low-stable (n=1161; range, 4.7-4.5), moderate-decreasing (n=3928; decreased from 6.9 to 6.0), moderate-increasing (n=1014; increased from 5.6 to 7.8), high-stable I (n=7940; range, 8.1-8.2), and high-stable II (n=3331; range, 9.2-9.7). During the median follow-up of 10.04 years, 288 incident MI cases were identified. After adjusting for potential confounders, compared with low-stable group, the hazard ratio and 95% CI of MI were 0.24 (0.15-0.40) for high-stable II, 0.36 (0.24-0.54) for high-stable I, 0.46 (0.25-0.83) for moderate-increasing, and 0.61 (0.41-0.90) for moderate-decreasing, respectively. Conclusions: In hypertensive patients, high-stable CHS or improvement in CHS is associated with a lower risk of incident MI, when compared with low-stable CHS trajectory over time.</p

Inflammatory bowel disease is causally related to irritable bowel syndrome: a bidirectional two-sample Mendelian randomization study

IntroductionInflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are lifelong digestive diseases that severely impact patients’ quality of life. The existence of a causal association between IBS and IBD remains unclear. This study aimed to determine the direction of causality between IBD and IBS by quantifying their genome-wide genetic associations and performing bidirectional two-sample Mendelian randomization (MR) analyses.MethodsGenome-wide association studies (GWAS) among a predominantly European patient cohort identified independent genetic variants associated with IBS and IBD. Two separate databases (a large GWAS meta-analysis and the FinnGen cohort) for both IBS and IBD were consulted to retrieve statistics on instrument-outcome associations. MR analyses included inverse-variance-weighted, weighted-median, MR-Egger regression, MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) methods, and sensitivity analyses were performed. The MR analyses were carried out for each outcome data, followed by a fixed-effect meta-analysis.ResultsGenetically predicted IBD was associated with an increased risk of IBS. Odds ratios (95% confidence intervals) for samples of 211,551 (17,302 individuals with IBD), 192,789 (7,476 Crohn’s disease cases), and 201,143 (10,293 ulcerative colitis cases) individuals were 1.20 (1.00, 1.04), 1.02 (1.01, 1.03), and 1.01 (0.99, 1.03), respectively. After outlier correction using MR-PRESSO, the odds ratio for ulcerative colitis was 1.03 (1.02, 1.05) (p = 0.001). However, an association between genetically influenced IBS and IBD was not identified.DiscussionThis study confirms that IBD is causally related to IBS, which may interfere with the diagnosis and treatment of both diseases