1
|
Qin Y, Cheng K, Jong MC, Zheng H, Cai Z, Xiao B, Zhou J. Symbiotic bacterial communities and carbon metabolic profiles of Acropora coral with varying health status under thermal stress. MARINE POLLUTION BULLETIN 2024; 209:117116. [PMID: 39418876 DOI: 10.1016/j.marpolbul.2024.117116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 09/21/2024] [Accepted: 10/05/2024] [Indexed: 10/19/2024]
Abstract
Thermal-induced coral bleaching has received substantial research attention; however, the dynamics of symbiotic coral-associated bacterial communities are underexplored and the roles of coral with intermediate health status remain unclear. Using high-throughput sequencing and biochemical analyses, we found that the symbiotic zooxanthellae number gradually decreased with the increase of bleaching degree (non-bleached, semi-bleached, and fully-bleached) in the coral Acropora pruinosa. The semi-bleached host exhibited a relatively more complex microbial interaction network. For the carbon metabolic profiles, relatively higher carbon-fixing abilities observed in non-bleached coral symbiotic bacteria, followed by semi-bleached host, and lowest values appeared in fully-bleached coral. Partial least-squares pathway modeling revealed that bacterial community features and carbon metabolic function were directly related with health status, while temperature exerted a strong influence on the bleaching resilience. These findings can help us better understand the coral microecological feature and carbon metabolic potential under changing environment.
Collapse
Affiliation(s)
- Yuke Qin
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen 518055, Guangdong Province, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China
| | - Keke Cheng
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen 518055, Guangdong Province, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China
| | - Mui-Choo Jong
- Institute of Environment and Ecology, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China
| | - Huina Zheng
- Shenzhen Research Institute, Guangdong Ocean University, Shenzhen 518120, Guangdong Province, PR China
| | - Zhonghua Cai
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen 518055, Guangdong Province, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China
| | - Baohua Xiao
- Shenzhen Research Institute, Guangdong Ocean University, Shenzhen 518120, Guangdong Province, PR China.
| | - Jin Zhou
- Marine Ecology and Human Factors Assessment Technical Innovation Center of Natural Resources Ministry, Tsinghua Shenzhen International Graduate School, Shenzhen 518055, Guangdong Province, PR China; Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China; Shenzhen Key Laboratory of Advanced Technology for Marine Ecology, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong Province, PR China.
| |
Collapse
|
2
|
Wei Y, Zhang W, Baguya EB, Gu Y, Yi K, Zhou J, Tong M. Bleached coral supports high diversity and heterogeneity of bacterial communities: Following the rule of the 'Anna Karenina principle'. ENVIRONMENTAL RESEARCH 2024; 262:119977. [PMID: 39265759 DOI: 10.1016/j.envres.2024.119977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 08/23/2024] [Accepted: 09/10/2024] [Indexed: 09/14/2024]
Abstract
Coral-associated bacteria are sensitive to the health status of coral and proven biomarker(s) of the coral bleaching. However, whether coral specificity or health status play a key role when coral-associated bacteria responding to coral bleaching is not known. Therefore, the bacterial communities of five species of healthy and bleached corals, Acropora millepora, Favites abdita, Galaxea fascicularis, Dipsastraea speciosa and Pocillopora damicornis, were collected along the coast of Sanya, South China Sea and targeted for associated bacterial studies. The relative abundance of the dominant class Gammaproteobacteria tended to be higher in healthy corals, while Alphaproteobacteria were more abundant in bleached corals. Dominant genus Achromobacter demonstrated higher relative abundance in healthy corals (0.675) than in bleached corals (0.151). Most of the bleached corals had high α diversity, β dispersion, heterogeneity and complexity of the co-occurrence network of bacterial communities, which support the 'Anna Karenina Principle (AKP)' of diverse in threatened objects and conserved in healthy ones. The bacterial communities in the bleached corals were mostly involved in the selection process, and communities in the healthy corals were involved in the undominated process, which is obtained based on the null model test of β nearest-taxon-index (βNTI) and Bray-Curtis-based Raup-Crick (RCBray). This evidence further confirmed the AKP and revealed that the bacterial communities in the bleached corals were driven by deterministic factors. These findings provide valuable insights into the connection between bacterial and coral status, and the application of the AKP in the changing patterns of bacterial communities during coral bleaching.
Collapse
Affiliation(s)
- Yihan Wei
- Ocean College, Zhejiang University, Zhoushan, 316021, China; Key Laboratory of Marine Environmental Survey Technology and Application, Ministry of Natural Resources, Guangzhou, 510030, China
| | - Wenguang Zhang
- Ocean College, Zhejiang University, Zhoushan, 316021, China
| | | | - Yu Gu
- Ocean College, Zhejiang University, Zhoushan, 316021, China
| | - Kehan Yi
- Ocean College, Zhejiang University, Zhoushan, 316021, China
| | - Jin Zhou
- Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518131, China
| | - Mengmeng Tong
- Ocean College, Zhejiang University, Zhoushan, 316021, China; Key Laboratory of Marine Environmental Survey Technology and Application, Ministry of Natural Resources, Guangzhou, 510030, China; Hainan Institute, Zhejiang University, Sanya, 572025, China.
| |
Collapse
|
3
|
Bai C, Wang Q, Xu J, Zhang H, Huang Y, Cai L, Zheng X, Yang M. Impact of Nutrient Enrichment on Community Structure and Co-Occurrence Networks of Coral Symbiotic Microbiota in Duncanopsammia peltata: Zooxanthellae, Bacteria, and Archaea. Microorganisms 2024; 12:1540. [PMID: 39203380 PMCID: PMC11356306 DOI: 10.3390/microorganisms12081540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/24/2024] [Accepted: 07/24/2024] [Indexed: 09/03/2024] Open
Abstract
Symbiotic microorganisms in reef-building corals, including algae, bacteria, archaea, fungi, and viruses, play critical roles in the adaptation of coral hosts to adverse environmental conditions. However, their adaptation and functional relationships in nutrient-rich environments have yet to be fully explored. This study investigated Duncanopsammia peltata and the surrounding seawater and sediments from protected and non-protected areas in the summer and winter in Dongshan Bay. High-throughput sequencing was used to characterize community changes, co-occurrence patterns, and factors influencing symbiotic coral microorganisms (zooxanthellae, bacteria, and archaea) in different environments. The results showed that nutrient enrichment in the protected and non-protected areas was the greatest in December, followed by the non-protected area in August. In contrast, the August protected area had the lowest nutrient enrichment. Significant differences were found in the composition of the bacterial and archaeal communities in seawater and sediments from different regions. Among the coral symbiotic microorganisms, the main dominant species of zooxanthellae is the C1 subspecies (42.22-56.35%). The dominant phyla of bacteria were Proteobacteria, Cyanobacteria, Firmicutes, and Bacteroidota. Only in the August protected area did a large number (41.98%) of SAR324_cladeMarine_group_B exist. The August protected and non-protected areas and December protected and non-protected areas contained beneficial bacteria as biomarkers. They were Nisaea, Spiroplasma, Endozoicomonas, and Bacillus. No pathogenic bacteria appeared in the protected area in August. The dominant phylum in Archaea was Crenarchaeota. These symbiotic coral microorganisms' relative abundances and compositions vary with environmental changes. The enrichment of dissolved inorganic nitrogen in environmental media is a key factor affecting the composition of coral microbial communities. Co-occurrence analysis showed that nutrient enrichment under anthropogenic disturbances enhanced the interactions between coral symbiotic microorganisms. These findings improve our understanding of the adaptations of coral holobionts to various nutritional environments.
Collapse
Affiliation(s)
- Chuanzhu Bai
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; (C.B.); (Y.H.)
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; (Q.W.); (H.Z.); (X.Z.)
| | - Qifang Wang
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; (Q.W.); (H.Z.); (X.Z.)
| | - Jinyan Xu
- Fujian Key Laboratory of Island Monitoring and Ecological Development (Island Research Center, MNR), Pingtan 350400, China;
| | - Han Zhang
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; (Q.W.); (H.Z.); (X.Z.)
| | - Yuxin Huang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; (C.B.); (Y.H.)
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; (Q.W.); (H.Z.); (X.Z.)
| | - Ling Cai
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; (Q.W.); (H.Z.); (X.Z.)
- Observation and Research Station of Island and Coastal Ecosystems in the Western Taiwan Strait, Ministry of Natural Resources, Xiamen 361005, China
| | - Xinqing Zheng
- Key Laboratory of Marine Ecology Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China; (Q.W.); (H.Z.); (X.Z.)
- Observation and Research Station of Island and Coastal Ecosystems in the Western Taiwan Strait, Ministry of Natural Resources, Xiamen 361005, China
- Fujian Provincial Station for Field Observation and Research of Island and Coastal Zone, Zhangzhou 363216, China
| | - Ming Yang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; (C.B.); (Y.H.)
| |
Collapse
|
4
|
Lai C, Chen L, Zhong X, Tang Z, Zhang B, Luo Y, Li C, Jin M, Chen X, Li J, Shi Y, Sun Y, Guo L. Long-term effects on liver metabolism induced by ceftriaxone sodium pretreatment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 335:122238. [PMID: 37506808 DOI: 10.1016/j.envpol.2023.122238] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/16/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023]
Abstract
Ceftriaxone is an emerging contaminant due to its potential harm, while its effects on liver are still need to be clarified. In this study, we first pretreated the 8-week-old C57BL/6J mice with high dose ceftriaxone sodium (Cef, 400 mg/mL, 0.2 mL per dose) for 8 days to prepare a gut dysbiosis model, then treated with normal feed for a two-month recovery period, and applied non-targeted metabolomics (including lipidomics) to investigate the variations of fecal and liver metabolome, and coupled with targeted determination of fecal short-chain fatty acids (SCFAs) and bile acids (BAs). Lastly, the correlations and mediation analysis between the liver metabolism and gut metabolism/microbes were carried, and the potential mechanisms of the mal-effects on gut-liver axis induced by Cef pretreatment were accordingly discussed. Compared to the control group, Cef pretreatment reduced the rate of weight gain and hepatosomatic index, induced bile duct epithelial cells proliferated around the central vein and appearance of binucleated hepatocytes, decreased the ratio of total branching chains amino acids (BCAAs) to total aromatic amino acids (AAAs) in liver metabolome. In fecal metabolome, the total fecal SCFAs and BAs did not change significantly while butyric acid decreased and the primary BAs increased after Cef pretreatment. Correlation and mediation analysis revealed one potential mechanism that Cef may first change the intestinal microbiota (such as destroying its normal structure, reducing its abundance and the stability of the microbial network or certain microbe abundance like Alistipes), and then change the intestinal metabolism (such as acetate, caproate, propionate), leading to liver metabolic disorder (such as spermidine, inosine, cinnamaldehyde). This study proved the possibility of Cef-induced liver damage, displayed the overall metabolic profile of the liver following Cef pretreatment and provided a theoretical framework for further research into the mechanism of Cef-induced liver damage.
Collapse
Affiliation(s)
- Chengze Lai
- The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, China; Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Linkang Chen
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Xiaoting Zhong
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Zeli Tang
- Department of Pathology, School of Basic Medical Sciences, Guangdong Medical University, Dongguan, China
| | - Bin Zhang
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Yu Luo
- Guangzhou Liwan District Center for Disease Control and Prevention, Guangzhou, Guangdong, China
| | - Chengji Li
- Yunfu Disease Control and Prevention Center, Guang Dong Province, China
| | - Mengcheng Jin
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Xu Chen
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Jinglin Li
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Yinying Shi
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Yanqin Sun
- Department of Pathology, School of Basic Medical Sciences, Guangdong Medical University, Dongguan, China
| | - Lianxian Guo
- The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, China; Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China.
| |
Collapse
|
5
|
Xu M, Cheng K, Xiao B, Tong M, Cai Z, Jong MC, Chen G, Zhou J. Bacterial Communities Vary from Different Scleractinian Coral Species and between Bleached and Non-Bleached Corals. Microbiol Spectr 2023; 11:e0491022. [PMID: 37191552 PMCID: PMC10269541 DOI: 10.1128/spectrum.04910-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 04/07/2023] [Indexed: 05/17/2023] Open
Abstract
Bleaching is one of the most relevant factors implicated in the integrity of coral reef ecosystems, with the increasing frequency and intensity of damaging events representing a serious threat to reef biodiversity. Here, we analyzed changes in coral-associated bacteria from three types of non-bleached and bleached scleractinian corals (Acropora digitifera, Galaxea fascicularis, and Porites pukoensis) in Hainan Luhuitou peninsula coastal areas. The community structure of symbiotic bacteria differed significantly among the three apparently healthy corals. The bleached corals had higher bacterial alpha diversity and some specific bacteria genera, including Ruegeria, Methyloceanibacter, Filomicrobium, Halioglobus, Rubripirellula, Rhodopirellula, Silicimonas, Blastopirellula, Sva0996 marine group, Woeseia, and unclassified_c_Gammaproteobacteria, were consistently increased in bleached groups. Network analysis revealed significantly different degrees of modularity between bleached and non-bleached groups at the bacterial genus level, and a higher proportion of links was dominated by positive co-occurrences. Functional prediction analysis illustrated that coral-associated bacteria remained relatively consistent in the bleached and non-bleached groups. Structure equation modeling revealed that the bacterial community diversity and function were directly influenced by host and environment factors. These findings suggested that coral-associated bacterial responses to bleaching occur in a host-dependent manner, informing novel strategies for restoring coral and aiding adaption to bleaching stress. IMPORTANCE Accumulating evidence indicates that coral-associated bacteria play an important role in the health of holobionts. However, the variability of the symbiotic bacterial community structure among coral species with different coral health statuses remains largely unknown. Here, we investigated three apparent non-bleached (healthy) and bleached coral species (sampled in situ), involving related symbiotic bacterial profiles, including composition, alpha diversity, network relationship, and potential function. Structural equation modeling analysis was used to analyze the relationship between coral status and abiotic and biotic factors. The bacterial community structure of different groups was shown to exhibit host-specific traits. Both host and environmental impacts had primary effects on coral-associated microbial communities. Future studies are needed to identify the mechanisms that mediate divergent microbial consortia.
Collapse
Affiliation(s)
- Meiting Xu
- School of Environment, Harbin Institute of Technology, Harbin, People’s Republic of China
- School of Marine Science and Technology, Harbin Institute of Technology (Weihai), Weihai, Shandong Province, People’s Republic of China
| | - Keke Cheng
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, People’s Republic of China
| | - Baohua Xiao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen, People’s Republic of China
| | - Mengmeng Tong
- Ocean College, Zhejiang University, Zhoushan, People’s Republic of China
| | - Zhonghua Cai
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, People’s Republic of China
| | - Mui-Choo Jong
- Institute of Environment and Ecology, Shenzhen International Graduate School, Tsinghua University, Shenzhen, People’s Republic of China
| | - Guofu Chen
- School of Environment, Harbin Institute of Technology, Harbin, People’s Republic of China
- School of Marine Science and Technology, Harbin Institute of Technology (Weihai), Weihai, Shandong Province, People’s Republic of China
| | - Jin Zhou
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Institute for Ocean Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, People’s Republic of China
| |
Collapse
|
6
|
Cheng K, Tong M, Cai Z, Jong MC, Zhou J, Xiao B. Prokaryotic and eukaryotic microbial communities associated with coral species have high host specificity in the South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161185. [PMID: 36581277 DOI: 10.1016/j.scitotenv.2022.161185] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 12/13/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Reef-building corals are well known for their obligate association with Symbiodiniaceae, and an array of other microbes, including bacteria, fungi, and symbiotic algae (i.e., total microbiome), which together form the coral holobiont. The total microbiome plays an intricate part in maintaining the homeostasis of the coral holobiont and is closely associated with host health. However, the composition of the coral associated microbiome and interaction between its different members remains elusive because few analyses have bridged taxonomically disparate groups. This research gaps have prevented a holistic understanding of the total microbiome. Thus, to simultaneously characterize the bacterial, fungal and symbiotic algal communities associated with different coral species, and explore the relationship between these symbionts and coral health, healthy and bleached tissues from four coral species, Acropora muricata, Galaxea fascicularis, Platygyra daedalea, and Pavona explanulata, were collected from the Xisha Islands of the South China Sea. Using high throughput sequencing, a high degree of host-specificity was observed among bacterial, fungal, and algal groups across coral species. There were no obvious changes in the microbial community structure of apparently healthy and bleached corals, but host bleaching allowed colonization of the holobionts by diverse opportunistic microbes, resulting in a significant elevation in the α-diversity of microbial communities. In addition, co-occurrence analysis of the coral microbiota also identified more complex microbial interactions in bleached corals than in healthy ones. In summary, this study characterized the structure of coral-associated microbiomes across four coral species, and systematically studied microbiome differences between healthy and bleached corals. The findings improve our understanding of the heterogeneity of symbiotic microorganisms and the impact of coral's physiological status on its associated microbial communities composition.
Collapse
Affiliation(s)
- Keke Cheng
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, PR China
| | - Mengmeng Tong
- Ocean College, Zhejiang University, Zhoushan 316021, PR China
| | - Zhonghua Cai
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, PR China
| | - Mui Choo Jong
- Institute of Environment and Ecology, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, PR China
| | - Jin Zhou
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, PR China.
| | - Baohua Xiao
- Shenzhen Institute of Guangdong Ocean University, Shenzhen 518114, PR China.
| |
Collapse
|
7
|
Abstract
We investigate financial market dynamics by introducing a heterogeneous agent-based opinion formation model. In this work, we organize individuals in a financial market according to their trading strategy, namely, whether they are noise traders or fundamentalists. The opinion of a local majority compels the market exchanging behavior of noise traders, whereas the global behavior of the market influences the decisions of fundamentalist agents. We introduce a noise parameter, q, to represent the level of anxiety and perceived uncertainty regarding market behavior, enabling the possibility of adrift financial action. We place individuals as nodes in an Erdös-Rényi random graph, where the links represent their social interactions. At any given time, individuals assume one of two possible opinion states ±1 regarding buying or selling an asset. The model exhibits fundamental qualitative and quantitative real-world market features such as the distribution of logarithmic returns with fat tails, clustered volatility, and the long-term correlation of returns. We use Student's t distributions to fit the histograms of logarithmic returns, showing a gradual shift from a leptokurtic to a mesokurtic regime depending on the fraction of fundamentalist agents. Furthermore, we compare our results with those concerning the distribution of the logarithmic returns of several real-world financial indices.
Collapse
|
8
|
Wu H, Meng X, Danziger MM, Cornelius SP, Tian H, Barabási AL. Fragmentation of outage clusters during the recovery of power distribution grids. Nat Commun 2022; 13:7372. [PMID: 36450824 PMCID: PMC9712383 DOI: 10.1038/s41467-022-35104-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
The understanding of recovery processes in power distribution grids is limited by the lack of realistic outage data, especially large-scale blackout datasets. By analyzing data from three electrical companies across the United States, we find that the recovery duration of an outage is connected with the downtime of its nearby outages and blackout intensity (defined as the peak number of outages during a blackout), but is independent of the number of customers affected. We present a cluster-based recovery framework to analytically characterize the dependence between outages, and interpret the dominant role blackout intensity plays in recovery. The recovery of blackouts is not random and has a universal pattern that is independent of the disruption cause, the post-disaster network structure, and the detailed repair strategy. Our study reveals that suppressing blackout intensity is a promising way to speed up restoration.
Collapse
Affiliation(s)
- Hao Wu
- State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing, 100876, China
- Center for Complex Networks Research, Department of Physics, Northeastern University, Boston, 02115, USA
| | - Xiangyi Meng
- Center for Complex Networks Research, Department of Physics, Northeastern University, Boston, 02115, USA
| | - Michael M Danziger
- Center for Complex Networks Research, Department of Physics, Northeastern University, Boston, 02115, USA
| | - Sean P Cornelius
- Department of Physics, Ryerson University, 350 Victoria Street, M5B 2K3, Toronto, Canada
| | - Hui Tian
- State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing, 100876, China.
| | - Albert-László Barabási
- Center for Complex Networks Research, Department of Physics, Northeastern University, Boston, 02115, USA
| |
Collapse
|
9
|
Artime O, De Domenico M. From the origin of life to pandemics: emergent phenomena in complex systems. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20200410. [PMID: 35599559 PMCID: PMC9125231 DOI: 10.1098/rsta.2020.0410] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 05/31/2023]
Abstract
When a large number of similar entities interact among each other and with their environment at a low scale, unexpected outcomes at higher spatio-temporal scales might spontaneously arise. This non-trivial phenomenon, known as emergence, characterizes a broad range of distinct complex systems-from physical to biological and social-and is often related to collective behaviour. It is ubiquitous, from non-living entities such as oscillators that under specific conditions synchronize, to living ones, such as birds flocking or fish schooling. Despite the ample phenomenological evidence of the existence of systems' emergent properties, central theoretical questions to the study of emergence remain unanswered, such as the lack of a widely accepted, rigorous definition of the phenomenon or the identification of the essential physical conditions that favour emergence. We offer here a general overview of the phenomenon of emergence and sketch current and future challenges on the topic. Our short review also serves as an introduction to the theme issue Emergent phenomena in complex physical and socio-technical systems: from cells to societies, where we provide a synthesis of the contents tackled in the issue and outline how they relate to these challenges, spanning from current advances in our understanding on the origin of life to the large-scale propagation of infectious diseases. This article is part of the theme issue 'Emergent phenomena in complex physical and socio-technical systems: from cells to societies'.
Collapse
Affiliation(s)
- Oriol Artime
- Fondazione Bruno Kessler, Via Sommarive 18, Povo, TN 38123, Italy
| | - Manlio De Domenico
- Department of Physics and Astronomy ‘Galileo Galilei’, University of Padua, Padova, Veneto, Italy
| |
Collapse
|
10
|
Valente A, De Domenico M, Artime O. Non-Markovian random walks characterize network robustness to nonlocal cascades. Phys Rev E 2022; 105:044126. [PMID: 35590548 DOI: 10.1103/physreve.105.044126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/14/2022] [Indexed: 06/15/2023]
Abstract
Localized perturbations in a real-world network have the potential to trigger cascade failures at the whole system level, hindering its operations and functions. Standard approaches analytically tackling this problem are mostly based either on static descriptions, such as percolation, or on models where the failure evolves through first-neighbor connections, crucially failing to capture the nonlocal behavior typical of real cascades. We introduce a dynamical model that maps the failure propagation across the network to a self-avoiding random walk that, at each step, has a probability to perform nonlocal jumps toward operational systems' units. Despite the inherent non-Markovian nature of the process, we are able to characterize the critical behavior of the system out of equilibrium, as well as the stopping time distribution of the cascades. Our numerical experiments on synthetic and empirical biological and transportation networks are in excellent agreement with theoretical expectation, demonstrating the ability of our framework to quantify the vulnerability to nonlocal cascade failures of complex systems with interconnected structure.
Collapse
Affiliation(s)
- Angelo Valente
- Department of Mathematics, University of Trento, 38123 Povo (TN), Italy
| | - Manlio De Domenico
- CoMuNe Lab, Department of Physics and Astronomy, University of Padua, 35131 Padua, Italy
| | - Oriol Artime
- CHuB Lab, Fondazione Bruno Kessler, 38123 Povo (TN), Italy
| |
Collapse
|
11
|
Baquero F, Martínez JL, F. Lanza V, Rodríguez-Beltrán J, Galán JC, San Millán A, Cantón R, Coque TM. Evolutionary Pathways and Trajectories in Antibiotic Resistance. Clin Microbiol Rev 2021; 34:e0005019. [PMID: 34190572 PMCID: PMC8404696 DOI: 10.1128/cmr.00050-19] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Evolution is the hallmark of life. Descriptions of the evolution of microorganisms have provided a wealth of information, but knowledge regarding "what happened" has precluded a deeper understanding of "how" evolution has proceeded, as in the case of antimicrobial resistance. The difficulty in answering the "how" question lies in the multihierarchical dimensions of evolutionary processes, nested in complex networks, encompassing all units of selection, from genes to communities and ecosystems. At the simplest ontological level (as resistance genes), evolution proceeds by random (mutation and drift) and directional (natural selection) processes; however, sequential pathways of adaptive variation can occasionally be observed, and under fixed circumstances (particular fitness landscapes), evolution is predictable. At the highest level (such as that of plasmids, clones, species, microbiotas), the systems' degrees of freedom increase dramatically, related to the variable dispersal, fragmentation, relatedness, or coalescence of bacterial populations, depending on heterogeneous and changing niches and selective gradients in complex environments. Evolutionary trajectories of antibiotic resistance find their way in these changing landscapes subjected to random variations, becoming highly entropic and therefore unpredictable. However, experimental, phylogenetic, and ecogenetic analyses reveal preferential frequented paths (highways) where antibiotic resistance flows and propagates, allowing some understanding of evolutionary dynamics, modeling and designing interventions. Studies on antibiotic resistance have an applied aspect in improving individual health, One Health, and Global Health, as well as an academic value for understanding evolution. Most importantly, they have a heuristic significance as a model to reduce the negative influence of anthropogenic effects on the environment.
Collapse
Affiliation(s)
- F. Baquero
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - J. L. Martínez
- National Center for Biotechnology (CNB-CSIC), Madrid, Spain
| | - V. F. Lanza
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Central Bioinformatics Unit, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - J. Rodríguez-Beltrán
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - J. C. Galán
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - A. San Millán
- National Center for Biotechnology (CNB-CSIC), Madrid, Spain
| | - R. Cantón
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - T. M. Coque
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| |
Collapse
|
12
|
Liu F, Wang Z, Deng Y. GMM: A generalized mechanics model for identifying the importance of nodes in complex networks. Knowl Based Syst 2020. [DOI: 10.1016/j.knosys.2019.105464] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
13
|
Sweet M, Burian A, Fifer J, Bulling M, Elliott D, Raymundo L. Compositional homogeneity in the pathobiome of a new, slow-spreading coral disease. MICROBIOME 2019; 7:139. [PMID: 31752998 PMCID: PMC6873542 DOI: 10.1186/s40168-019-0759-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 10/13/2019] [Indexed: 05/04/2023]
Abstract
BACKGROUND Coral reefs face unprecedented declines in diversity and cover, a development largely attributed to climate change-induced bleaching and subsequent disease outbreaks. Coral-associated microbiomes may strongly influence the fitness of their hosts and alter heat tolerance and disease susceptibility of coral colonies. Here, we describe a new coral disease found in Micronesia and present a detailed assessment of infection-driven changes in the coral microbiome. RESULTS Combining field monitoring and histological, microscopic and next-generation barcoding assessments, we demonstrate that the outbreak of the disease, named 'grey-patch disease', is associated with the establishment of cyanobacterial biofilm overgrowing coral tissue. The disease is characterised by slow progression rates, with coral tissue sometimes growing back over the GPD biofilm. Network analysis of the corals' microbiome highlighted the clustering of specific microbes which appeared to benefit from the onset of disease, resulting in the formation of 'infection clusters' in the microbiomes of apparently healthy corals. CONCLUSIONS Our results appear to be in contrast to the recently proposed Anna-Karenina principle, which states that disturbances (such as disease) trigger chaotic dynamics in microbial communities and increase β-diversity. Here, we show significantly higher community similarity (compositional homogeneity) in the pathobiome of diseased corals, compared to the microbiome associated with apparently healthy tissue. A possible explanation for this pattern is strong competition between the pathogenic community and those associated with the 'healthy' coral holobiont, homogenising the composition of the pathobiome. Further, one of our key findings is that multiple agents appear to be involved in degrading the corals' defences causing the onset of this disease. This supports recent findings indicating a need for a shift from the one-pathogen-one-disease paradigm to exploring the importance of multiple pathogenic players in any given disease.
Collapse
Affiliation(s)
- Michael Sweet
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, UK.
| | - Alfred Burian
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, UK
| | - James Fifer
- Marine Laboratory, University of Guam, Mangilao, GU, 96923, Guam
| | - Mark Bulling
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, UK
| | - David Elliott
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, UK
| | - Laurie Raymundo
- Marine Laboratory, University of Guam, Mangilao, GU, 96923, Guam
| |
Collapse
|
14
|
Duan D, Lv C, Si S, Wang Z, Li D, Gao J, Havlin S, Stanley HE, Boccaletti S. Universal behavior of cascading failures in interdependent networks. Proc Natl Acad Sci U S A 2019; 116:22452-22457. [PMID: 31624122 PMCID: PMC6842597 DOI: 10.1073/pnas.1904421116] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Catastrophic and major disasters in real-world systems, such as blackouts in power grids or global failures in critical infrastructures, are often triggered by minor events which originate a cascading failure in interdependent graphs. We present here a self-consistent theory enabling the systematic analysis of cascading failures in such networks and encompassing a broad range of dynamical systems, from epidemic spreading, to birth-death processes, to biochemical and regulatory dynamics. We offer testable predictions on breakdown scenarios, and, in particular, we unveil the conditions under which the percolation transition is of the first-order or the second-order type, as well as prove that accounting for dynamics in the nodes always accelerates the cascading process. Besides applying directly to relevant real-world situations, our results give practical hints on how to engineer more robust networked systems.
Collapse
Affiliation(s)
- Dongli Duan
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, China
- School of Information and Control Engineering, Xi'an University of Architecture and Technology, Xi'an 710311, China
| | - Changchun Lv
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, China
| | - Shubin Si
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, China;
| | - Zhen Wang
- School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an 710072, China;
- Center for OPTical IMagery Analysis and Learning, Northwestern Polytechnical University, Xi'an 710072, China
| | - Daqing Li
- School of Reliability and Systems Engineering, Beihang University, Beijing 100191, China
| | - Jianxi Gao
- Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY 12180
- Network Science and Technology Center, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Shlomo Havlin
- Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - H Eugene Stanley
- Center for Polymer Studies, Department of Physics, Boston University, Boston, MA 02215;
| | - Stefano Boccaletti
- Institute of Complex Systems, Consiglio Nazionale delle Ricerche, Florence 50019, Italy
- Unmanned Systems Research Institute, Northwestern Polytechnical University, Xi'an 710072, China
| |
Collapse
|
15
|
Li J, Xia C, Xiao G, Moreno Y. Crash dynamics of interdependent networks. Sci Rep 2019; 9:14574. [PMID: 31601907 PMCID: PMC6787334 DOI: 10.1038/s41598-019-51030-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/20/2019] [Indexed: 11/24/2022] Open
Abstract
The emergence and evolution of real-world systems have been extensively studied in the last few years. However, equally important phenomena are related to the dynamics of systems' collapse, which has been less explored, especially when they can be cast into interdependent systems. In this paper, we develop a dynamical model that allows scrutinizing the collapse of systems composed of two interdependent networks. Specifically, we explore the dynamics of the system's collapse under two scenarios: in the first one, the condition for failure should be satisfied for the focal node as well as for its corresponding node in the other network; while in the second one, it is enough that failure of one of the nodes occurs in either of the two networks. We report extensive numerical simulations of the dynamics performed in different setups of interdependent networks, and analyze how the system behavior depends on the previous scenarios as well as on the topology of the interdependent system. Our results can provide valuable insights into the crashing dynamics and evolutionary properties of interdependent complex systems.
Collapse
Affiliation(s)
- Jie Li
- Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin, 300384, China
- Key Laboratory of Computer Vision and System (Ministry of Education), Tianjin University of Technology, Tianjin, 300384, China
| | - Chengyi Xia
- Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin, 300384, China.
- Key Laboratory of Computer Vision and System (Ministry of Education), Tianjin University of Technology, Tianjin, 300384, China.
| | - Gaoxi Xiao
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
- Complexity Institute, Nanyang Technological University, Singapore, 637335, Singapore.
| | - Yamir Moreno
- Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, Zaragoza, 50018, Spain
- Departamento de Física Teórica, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza, 50009, Spain
- ISI Foundation, Turin, Italy
| |
Collapse
|
16
|
A Survey on Power System Blackout and Cascading Events: Research Motivations and Challenges. ENERGIES 2019. [DOI: 10.3390/en12040682] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Power systems are the most complex systems and have great importance in modern life. They have direct impacts on the modernization, economic, political and social aspects. To operate such systems in a stable mode, several control and protection techniques are required. However, modern systems are equipped with several protection schemes with the aim of avoiding the unpredicted events and power outages, power systems are still encountering emergency and mal-operation situations. The most severe emergencies put the whole or at least a part of the system in danger. If the emergency is not well managed, the power system is likely to have cascading failures that might lead to a blackout. Due to the consequences, many countries around the world have research and expert teams who work to avoid blackouts on their systems. In this paper, a comprehensive review on the major blackouts and cascading events that have occurred in the last decade are introduced. A particular focus is given on the US power system outages and their causes since it is one of the leading power producers in the world and it is also due to the ready availability of data for the past events. The paper also highlights the root causes of different blackouts around the globe. Furthermore, blackout and cascading analysis methods and the consequences of blackouts are surveyed. Moreover, the challenges in the existing protective schemes and research gaps in the topic of power system blackout and cascading events are marked out. Research directions and issues to be considered in future power system blackout studies are also proposed.
Collapse
|
17
|
Wu Y, Zhang S, Zhang Z. Environment-based preference selection promotes cooperation in spatial prisoner's dilemma game. Sci Rep 2018; 8:15616. [PMID: 30353150 PMCID: PMC6199282 DOI: 10.1038/s41598-018-34116-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/11/2018] [Indexed: 11/14/2022] Open
Abstract
The impact of environment on individuals is particularly critical. In evolutionary games, adopting the strategy of the neighbor who performs better is nontrivial for the survival and maintenance of cooperation, in that such an action may help the agents to obtain higher benefit and more obvious evolutionary advantages. Inspired by this idea, we investigate the effect of the environment-based preference selection on the evolution of cooperation in spatial prisoner’s dilemma. A simple rule, incorporating individual preference selection via an adjustable parameter α to explore how the selection of the potential strategy sources influences individual behavior traits, is considered. Because social interaction may not be the only way of generating payoffs, we assume that the individual’s income is also affected by the environment. Besides, taking into account individual differences, we introduce the heterogeneity of the environment. Through numerous computing simulations, we find that environment-based preference selection, which accelerates the microscopic organization of cooperator clusters to resist the aggression of defectors, can truly promote cooperation within a large range of parameters. Our study indicates that the combination of heterogeneity and preference selection may be key for the sustainability of cooperation in structured populations.
Collapse
Affiliation(s)
- Yu'e Wu
- Coordinated Innovation Center for Computable Modeling in Management Science, Tianjin University of Finance and Economics, Tianjin, 300222, China
| | - Shuhua Zhang
- Coordinated Innovation Center for Computable Modeling in Management Science, Tianjin University of Finance and Economics, Tianjin, 300222, China.
| | - Zhipeng Zhang
- Coordinated Innovation Center for Computable Modeling in Management Science, Tianjin University of Finance and Economics, Tianjin, 300222, China
| |
Collapse
|
18
|
|
19
|
Zhou D, Elmokashfi A. Network recovery based on system crash early warning in a cascading failure model. Sci Rep 2018; 8:7443. [PMID: 29748570 PMCID: PMC5945858 DOI: 10.1038/s41598-018-25591-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/19/2018] [Indexed: 11/09/2022] Open
Abstract
This paper investigates the possibility of saving a network that is predicted to have a cascading failure that will eventually lead to a total collapse. We model cascading failures using the recently proposed KQ model. Then predict an impending total collapse by monitoring critical slowing down indicators and subsequently attempt to prevent the total collapse of the network by adding new nodes. To this end, we systematically evaluate five node addition rules, the effect of intervention delay and network degree heterogeneity. Surprisingly, unlike for random homogeneous networks, we find that a delayed intervention is preferred for saving scale free networks. We also find that for homogeneous networks, the best strategy is to wire newly added nodes to existing nodes in a uniformly random manner. For heterogeneous networks, however, a random selection of nodes based on their degree mostly outperforms a uniform random selection. These results provide new insights into restoring networks by adding nodes after observing early warnings of an impending complete breakdown.
Collapse
Affiliation(s)
- Dong Zhou
- Simula Metropolitan CDE, Fornebu, 1364, Norway
| | | |
Collapse
|
20
|
Seki K, Nakamura M. The mechanism of collapse of the Friendster network: What can we learn from the core structure of Friendster? SOCIAL NETWORK ANALYSIS AND MINING 2017. [DOI: 10.1007/s13278-017-0429-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
21
|
Sensing Attribute Weights: A Novel Basic Belief Assignment Method. SENSORS 2017; 17:s17040721. [PMID: 28358325 PMCID: PMC5421681 DOI: 10.3390/s17040721] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 02/04/2023]
Abstract
Dempster-Shafer evidence theory is widely used in many soft sensors data fusion systems on account of its good performance for handling the uncertainty information of soft sensors. However, how to determine basic belief assignment (BBA) is still an open issue. The existing methods to determine BBA do not consider the reliability of each attribute; at the same time, they cannot effectively determine BBA in the open world. In this paper, based on attribute weights, a novel method to determine BBA is proposed not only in the closed world, but also in the open world. The Gaussian model of each attribute is built using the training samples firstly. Second, the similarity between the test sample and the attribute model is measured based on the Gaussian membership functions. Then, the attribute weights are generated using the overlap degree among the classes. Finally, BBA is determined according to the sensed attribute weights. Several examples with small datasets show the validity of the proposed method.
Collapse
|
22
|
Jiang W, Wei B, Tang Y, Zhou D. Ordered visibility graph average aggregation operator: An application in produced water management. CHAOS (WOODBURY, N.Y.) 2017; 27:023117. [PMID: 28249408 DOI: 10.1063/1.4977186] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Complex networks are widely used in modeling complex system. How to aggregate data in complex systems is still an open issue. In this paper, an ordered visibility graph average aggregation operator is proposed which is inspired by the complex network theory and Newton's law of universal gravitation. First of all, the argument values are ordered in descending order. Then a new support function is proposed to measure the relationship among values in a visibility graph. After that, a weighted network is constructed to determine the weight of each value. Compared with the other operators, the new operator fully takes into account not only the information of orders but also the correlation degree between the values. Finally, an application of produced water management is illustrated to show the efficiency of the proposed method. The new method provides a universal way to aggregate data in complex systems.
Collapse
Affiliation(s)
- Wen Jiang
- School of Electronics and Information, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Boya Wei
- School of Electronics and Information, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Yongchuan Tang
- School of Electronics and Information, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Deyun Zhou
- School of Electronics and Information, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| |
Collapse
|
23
|
Affiliation(s)
- Debra Toiber
- Department of Life Sciences, Ben-Gurion University of the Negev , Beer Sheva, Israel
| | - Gabriel Leprivier
- Department of Pediatric Oncology, Hematology and Clinical ImmunologyHeine University , Dusseldorf, Germany
| | - Barak Rotblat
- Department of Life Sciences, Ben-Gurion University of the Negev , Beer Sheva, Israel
| |
Collapse
|