80 research outputs found
Thermal discharge-created increasing temperatures alter the bacterioplankton composition and functional redundancy
Additional file 1: Table S1. Measurements of geochemical factors of the 10 sampling sites. Table S2. Pearson correlations between seawater temperature and biogeochemical variables. Figure S1. Pearson correlations between seawater temperature and bacterial abundance (A), DNA yield (a proxy for microbial biomass) (B), and grazing rate (C). Figure S2. Multivariate regression tree (MRT) of bacterial diversity associated with driving biogeochemical factors
Structural Mutual Information and Its Application
Shannon mutual information is an effective method to analyze the information interaction in a point-to-point communication system. However, it cannot solve the problem of channel capacity in graph structure communication system. This problem make it impossible to use traditional mutual information (TMI) to detect the real information and to measure the information embedded in the graph structure. Therefore, measuring the interaction of graph structure and the degree of privacy leakage has become an emerging and challenging issue to be considered. To solve this issue, we propose a novel structural mutual information (SMI) theory based on structure entropy model and the Shannon mutual information theorem, following by the algorithms for solving SMI. The SMI is used to detect the real network structure and measure the degree of private data leakage in the graph structure. Our work expands the channel capacity of Shannonβs second theorem in graph structure, discusses the correlation properties between SMI and TMI, and concludes that SMI satisfies some basic properties, including symmetry, non-negativity, and so on. Finally, theoretical analysis and example demonstration show that the SMI theory is more effective than the traditional privacy measurement methods to measure the information amount embedded in the graph structure and the overall degree of privacy leakage. It provides feasible theoretical support for the privacy protection technology in the graph structure
Privacy Attacks and Defenses for Digital Twin Migrations in Vehicular Metaverses
The gradual fusion of intelligent transportation systems with metaverse
technologies is giving rise to vehicular metaverses, which blend virtual spaces
with physical space. As indispensable components for vehicular metaverses,
Vehicular Twins (VTs) are digital replicas of Vehicular Metaverse Users (VMUs)
and facilitate customized metaverse services to VMUs. VTs are established and
maintained in RoadSide Units (RSUs) with sufficient computing and storage
resources. Due to the limited communication coverage of RSUs and the high
mobility of VMUs, VTs need to be migrated among RSUs to ensure real-time and
seamless services for VMUs. However, during VT migrations, physical-virtual
synchronization and massive communications among VTs may cause identity and
location privacy disclosures of VMUs and VTs. In this article, we study privacy
issues and the corresponding defenses for VT migrations in vehicular
metaverses. We first present four kinds of specific privacy attacks during VT
migrations. Then, we propose a VMU-VT dual pseudonym scheme and a synchronous
pseudonym change framework to defend against these attacks. Additionally, we
evaluate average privacy entropy for pseudonym changes and optimize the number
of pseudonym distribution based on inventory theory. Numerical results show
that the average utility of VMUs under our proposed schemes is 33.8% higher
than that under the equal distribution scheme, demonstrating the superiority of
our schemes.Comment: 8 pages, 6 figure
A Novel Cyberspace-Oriented Access Control Model
With the developments of mobile communication, networks and information technology, many new information service patterns and dissemination modes emerge with some security and privacy threats in access control, i.e., the ownership of data is separated from the administration of them, secondary/mutiple information distribution etc. Existing access control models, which are always proposed for some specific scenarios, are hardly to achieve fine-grained and adaptive access control. In this paper, we propose a novel Cyberspace-oriented Access Control model, termed as CoAC, which avoids the aforementioned threats by comprehensively considering some vital factors, such as the access requesting entity, general tense, access point, resource, device, networks, internet-based interactive graph and chain of resource transmission. By appropriately adjusting these factors, CoAC covers most of typical access control models and fulfills the requirements of new information service patterns and dissemination modes. We also present the administrative model of our proposed CoAC model and formally describe the administrative functions and methods used in the administrative model by utilizing Z-notation. Our CoAC is flexible and scalable, it can be further refined and expanded to figure out new opportunities and challenges in the upcoming access control techniques
Assessing the Microbial Community and Functional Genes in a Vertical Soil Profile with Long-Term Arsenic Contamination
Conceived and designed the experiments: GW. Performed the experiments: JX GL. Analyzed the data: JX JZ GW. Contributed reagents/materials/analysis tools: ST JZ GW. Wrote the paper: JX ZH JDVN JZ GW.Arsenic (As) contamination in soil and groundwater has become a serious problem to public health. To examine how microbial communities and functional genes respond to long-term arsenic contamination in vertical soil profile, soil samples were collected from the surface to the depth of 4 m (with an interval of 1 m) after 16-year arsenic downward infiltration. Integrating BioLog and functional gene microarray (GeoChip 3.0) technologies, we showed that microbial metabolic potential and diversity substantially decreased, and community structure was markedly distinct along the depth. Variations in microbial community functional genes, including genes responsible for As resistance, carbon and nitrogen cycling, phosphorus utilization and cytochrome c oxidases were detected. In particular, changes in community structures and activities were correlated with the biogeochemical features along the vertical soil profile when using the rbcL and nifH genes as biomarkers, evident for a gradual transition from aerobic to anaerobic lifestyles. The C/N showed marginally significant correlations with arsenic resistance (pβ=β0.069) and carbon cycling genes (pβ=β0.073), and significant correlation with nitrogen fixation genes (pβ=β0.024). The combination of C/N, NO3β and P showed the highest correlation (rβ=β0.779, pβ=β0.062) with the microbial community structure. Contradict to our hypotheses, a long-term arsenic downward infiltration was not the primary factor, while the spatial isolation and nutrient availability were the key forces in shaping the community structure. This study provides new insights about the heterogeneity of microbial community metabolic potential and future biodiversity preservation for arsenic bioremediation management.Yeshttp://www.plosone.org/static/editorial#pee
Geographic distance and pH drive bacterial distribution in alkaline lake sediments across Tibetan Plateau.
CP-ABE-Based Secure and Verifiable Data Deletion in Cloud
Cloud data, the ownership of which is separated from their administration, usually contain usersβ private information, especially in the fifth-generation mobile communication (5G) environment, because of collecting data from various smart mobile devices inevitably containing personal information. If it is not securely deleted in time or the result of data deletion cannot be verified after their expiration, this will lead to serious issues, such as unauthorized access and data privacy disclosure. Therefore, this affects the security of cloud data and hinders the development of cloud computing services seriously. In this paper, we propose a novel secure data deletion and verification (SDVC) scheme based on CP-ABE to achieve fine-grained secure data deletion and deletion verification for cloud data. Based on the idea of access policy in CP-ABE, we construct an attribute association tree to implement fast revoking attribute and reencrypting key to achieve fine-grained control of secure key deletion. Furthermore, we build a rule transposition algorithm to generate random data blocks and combine the overwriting technology with the Merkle hash tree to implement secure ciphertext deletion and generate a validator, which is then used to verify the result of data deletion. We prove the security of the SDVC scheme under the standard model and verify the correctness and effectiveness of the SDVC scheme through theoretical analysis and ample simulation experiment results
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