--- _id: '8263' abstract: - lang: eng text: "Background: The genus Streptococcus comprises pathogens that strongly influence the health of humans and animals. Genome sequencing of multiple Streptococcus strains demonstrated high variability in gene content and order even in closely related strains of the same species and created a newly emerged object for genomic analysis, the pan-genome. Here we analysed the genome evolution of 25 strains of Streptococcus suis, 50 strains of Streptococcus pyogenes and 28 strains of Streptococcus pneumoniae.\r\n\r\nResults: Fractions of the pan-genome, unique, periphery, and universal genes differ in size, functional composition, the level of nucleotide substitutions, and predisposition to horizontal gene transfer and genomic rearrangements. The density of substitutions in intergenic regions appears to be correlated with selection acting on adjacent genes, implying that more conserved genes tend to have more conserved regulatory regions.\r\nThe total pan-genome of the genus is open, but only due to strain-specific genes, whereas other pan-genome fractions reach saturation. We have identified the set of genes with phylogenies inconsistent with species and non-conserved location in the chromosome; these genes are rare in at least one species and have likely experienced recent horizontal transfer between species. The strain-specific fraction is enriched with mobile elements and hypothetical proteins, but also contains a number of candidate virulence-related genes, so it may have a strong impact on adaptability and pathogenicity.\r\nMapping the rearrangements to the phylogenetic tree revealed large parallel inversions in all species. A parallel inversion of length 15 kB with breakpoints formed by genes encoding surface antigen proteins PhtD and PhtB in S. pneumoniae leads to replacement of gene fragments that likely indicates the action of an antigen variation mechanism.\r\n\r\nConclusions: Members of genus Streptococcus have a highly dynamic, open pan-genome, that potentially confers them with the ability to adapt to changing environmental conditions, i.e. antibiotic resistance or transmission between different hosts. Hence, integrated analysis of all aspects of genome evolution is important for the identification of potential pathogens and design of drugs and vaccines." article_number: '83' article_processing_charge: No article_type: original author: - first_name: Pavel V. full_name: Shelyakin, Pavel V. last_name: Shelyakin orcid: 0000-0003-0120-9319 - first_name: Olga full_name: Bochkareva, Olga id: C4558D3C-6102-11E9-A62E-F418E6697425 last_name: Bochkareva orcid: 0000-0003-1006-6639 - first_name: Anna A. full_name: Karan, Anna A. last_name: Karan - first_name: Mikhail S. full_name: Gelfand, Mikhail S. last_name: Gelfand citation: ama: 'Shelyakin PV, Bochkareva O, Karan AA, Gelfand MS. Micro-evolution of three Streptococcus species: Selection, antigenic variation, and horizontal gene inflow. BMC Evolutionary Biology. 2019;19. doi:10.1186/s12862-019-1403-6' apa: 'Shelyakin, P. V., Bochkareva, O., Karan, A. A., & Gelfand, M. S. (2019). Micro-evolution of three Streptococcus species: Selection, antigenic variation, and horizontal gene inflow. BMC Evolutionary Biology. Springer Nature. https://doi.org/10.1186/s12862-019-1403-6' chicago: 'Shelyakin, Pavel V., Olga Bochkareva, Anna A. Karan, and Mikhail S. Gelfand. “Micro-Evolution of Three Streptococcus Species: Selection, Antigenic Variation, and Horizontal Gene Inflow.” BMC Evolutionary Biology. Springer Nature, 2019. https://doi.org/10.1186/s12862-019-1403-6.' ieee: 'P. V. Shelyakin, O. Bochkareva, A. A. Karan, and M. S. Gelfand, “Micro-evolution of three Streptococcus species: Selection, antigenic variation, and horizontal gene inflow,” BMC Evolutionary Biology, vol. 19. Springer Nature, 2019.' ista: 'Shelyakin PV, Bochkareva O, Karan AA, Gelfand MS. 2019. Micro-evolution of three Streptococcus species: Selection, antigenic variation, and horizontal gene inflow. BMC Evolutionary Biology. 19, 83.' mla: 'Shelyakin, Pavel V., et al. “Micro-Evolution of Three Streptococcus Species: Selection, Antigenic Variation, and Horizontal Gene Inflow.” BMC Evolutionary Biology, vol. 19, 83, Springer Nature, 2019, doi:10.1186/s12862-019-1403-6.' short: P.V. Shelyakin, O. Bochkareva, A.A. Karan, M.S. Gelfand, BMC Evolutionary Biology 19 (2019). date_created: 2020-08-15T11:04:07Z date_published: 2019-03-27T00:00:00Z date_updated: 2023-02-23T13:28:54Z day: '27' doi: 10.1186/s12862-019-1403-6 extern: '1' intvolume: ' 19' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1186/s12862-019-1403-6 month: '03' oa: 1 oa_version: Published Version publication: BMC Evolutionary Biology publication_identifier: issn: - 1471-2148 publication_status: published publisher: Springer Nature quality_controlled: '1' status: public title: 'Micro-evolution of three Streptococcus species: Selection, antigenic variation, and horizontal gene inflow' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 19 year: '2019' ... --- _id: '8281' abstract: - lang: eng text: We review the history of population genetics, starting with its origins a century ago from the synthesis between Mendel and Darwin's ideas, through to the recent development of sophisticated schemes of inference from sequence data, based on the coalescent. We explain the close relation between the coalescent and a diffusion process, which we illustrate by their application to understand spatial structure. We summarise the powerful methods available for analysis of multiple loci, when linkage equilibrium can be assumed, and then discuss approaches to the more challenging case, where associations between alleles require that we follow genotype, rather than allele, frequencies. Though we can hardly cover the whole of population genetics, we give an overview of the current state of the subject, and future challenges to it. article_processing_charge: No author: - first_name: Nicholas H full_name: Barton, Nicholas H id: 4880FE40-F248-11E8-B48F-1D18A9856A87 last_name: Barton orcid: 0000-0002-8548-5240 - first_name: Alison full_name: Etheridge, Alison last_name: Etheridge citation: ama: 'Barton NH, Etheridge A. Mathematical models in population genetics. In: Balding D, Moltke I, Marioni J, eds. Handbook of Statistical Genomics. 4th ed. Wiley; 2019:115-144. doi:10.1002/9781119487845.ch4' apa: Barton, N. H., & Etheridge, A. (2019). Mathematical models in population genetics. In D. Balding, I. Moltke, & J. Marioni (Eds.), Handbook of statistical genomics (4th ed., pp. 115–144). Wiley. https://doi.org/10.1002/9781119487845.ch4 chicago: Barton, Nicholas H, and Alison Etheridge. “Mathematical Models in Population Genetics.” In Handbook of Statistical Genomics, edited by David Balding, Ida Moltke, and John Marioni, 4th ed., 115–44. Wiley, 2019. https://doi.org/10.1002/9781119487845.ch4. ieee: N. H. Barton and A. Etheridge, “Mathematical models in population genetics,” in Handbook of statistical genomics, 4th ed., D. Balding, I. Moltke, and J. Marioni, Eds. Wiley, 2019, pp. 115–144. ista: 'Barton NH, Etheridge A. 2019.Mathematical models in population genetics. In: Handbook of statistical genomics. , 115–144.' mla: Barton, Nicholas H., and Alison Etheridge. “Mathematical Models in Population Genetics.” Handbook of Statistical Genomics, edited by David Balding et al., 4th ed., Wiley, 2019, pp. 115–44, doi:10.1002/9781119487845.ch4. short: N.H. Barton, A. Etheridge, in:, D. Balding, I. Moltke, J. Marioni (Eds.), Handbook of Statistical Genomics, 4th ed., Wiley, 2019, pp. 115–144. date_created: 2020-08-21T04:25:39Z date_published: 2019-07-29T00:00:00Z date_updated: 2023-09-08T11:24:15Z day: '29' ddc: - '576' department: - _id: NiBa doi: 10.1002/9781119487845.ch4 edition: '4' editor: - first_name: David full_name: Balding, David last_name: Balding - first_name: Ida full_name: Moltke, Ida last_name: Moltke - first_name: John full_name: Marioni, John last_name: Marioni external_id: isi: - '000261343000003' isi: 1 language: - iso: eng month: '07' oa_version: None page: 115-144 publication: Handbook of statistical genomics publication_identifier: isbn: - '9781119429142' publication_status: published publisher: Wiley quality_controlled: '1' status: public title: Mathematical models in population genetics type: book_chapter user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2019' ... --- _id: '8296' abstract: - lang: eng text: While showing great promise, smart contracts are difficult to program correctly, as they need a deep understanding of cryptography and distributed algorithms, and offer limited functionality, as they have to be deterministic and cannot operate on secret data. In this paper we present Protean, a general-purpose decentralized computing platform that addresses these limitations by moving from a monolithic execution model, where all participating nodes store all the state and execute every computation, to a modular execution-model. Protean employs secure specialized modules, called functional units, for building decentralized applications that are currently insecure or impossible to implement with smart contracts. Each functional unit is a distributed system that provides a special-purpose functionality by exposing atomic transactions to the smart-contract developer. Combining these transactions into arbitrarily-defined workflows, developers can build a larger class of decentralized applications, such as provably-secure and fair lotteries or e-voting. article_processing_charge: No author: - first_name: Enis Ceyhun full_name: Alp, Enis Ceyhun last_name: Alp - first_name: Eleftherios full_name: Kokoris Kogias, Eleftherios id: f5983044-d7ef-11ea-ac6d-fd1430a26d30 last_name: Kokoris Kogias - first_name: Georgia full_name: Fragkouli, Georgia last_name: Fragkouli - first_name: Bryan full_name: Ford, Bryan last_name: Ford citation: ama: 'Alp EC, Kokoris Kogias E, Fragkouli G, Ford B. Rethinking general-purpose decentralized computing. In: Proceedings of the Workshop on Hot Topics in Operating Systems. ACM; 2019:105-112. doi:10.1145/3317550.3321448' apa: 'Alp, E. C., Kokoris Kogias, E., Fragkouli, G., & Ford, B. (2019). Rethinking general-purpose decentralized computing. In Proceedings of the Workshop on Hot Topics in Operating Systems (pp. 105–112). Bertinoro, Italy: ACM. https://doi.org/10.1145/3317550.3321448' chicago: Alp, Enis Ceyhun, Eleftherios Kokoris Kogias, Georgia Fragkouli, and Bryan Ford. “Rethinking General-Purpose Decentralized Computing.” In Proceedings of the Workshop on Hot Topics in Operating Systems, 105–12. ACM, 2019. https://doi.org/10.1145/3317550.3321448. ieee: E. C. Alp, E. Kokoris Kogias, G. Fragkouli, and B. Ford, “Rethinking general-purpose decentralized computing,” in Proceedings of the Workshop on Hot Topics in Operating Systems, Bertinoro, Italy, 2019, pp. 105–112. ista: 'Alp EC, Kokoris Kogias E, Fragkouli G, Ford B. 2019. Rethinking general-purpose decentralized computing. Proceedings of the Workshop on Hot Topics in Operating Systems. HotOS: Workshop on Hot Topics in Operating Systems, 105–112.' mla: Alp, Enis Ceyhun, et al. “Rethinking General-Purpose Decentralized Computing.” Proceedings of the Workshop on Hot Topics in Operating Systems, ACM, 2019, pp. 105–12, doi:10.1145/3317550.3321448. short: E.C. Alp, E. Kokoris Kogias, G. Fragkouli, B. Ford, in:, Proceedings of the Workshop on Hot Topics in Operating Systems, ACM, 2019, pp. 105–112. conference: end_date: 2019-05-15 location: Bertinoro, Italy name: 'HotOS: Workshop on Hot Topics in Operating Systems' start_date: 2019-05-13 date_created: 2020-08-26T11:45:45Z date_published: 2019-05-01T00:00:00Z date_updated: 2021-01-12T08:17:56Z day: '01' doi: 10.1145/3317550.3321448 extern: '1' language: - iso: eng month: '05' oa_version: None page: 105-112 publication: Proceedings of the Workshop on Hot Topics in Operating Systems publication_identifier: isbn: - '9781450367271' publication_status: published publisher: ACM quality_controlled: '1' scopus_import: '1' status: public title: Rethinking general-purpose decentralized computing type: conference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2019' ... --- _id: '8303' abstract: - lang: eng text: 'ByzCoin, a promising alternative of Bitcoin, is a scalable consensus protocol used as a building block of many research and enterprise-level decentralized systems. In this paper, we show that ByzCoin is unsuitable for deployment in an anopen, adversarial network and instead introduceMOTOR. MOTORis designed as a secure, robust, and scalable consensus suitable for permissionless sharded blockchains. MOTORachieves these properties by making four key design choices: (a) it prioritizes robustness in adversarial environments while maintaining adequate scalability, (b) it employees provably correct cryptography that resists DoS attacks from individual nodes, (c) it deploys unpredictable rotating leaders to defend against mildly-adaptive adversaries and prevents censorship, and (d) it creates an incentive compatible reward mechanism. These choices are materialized as (a) a “rotating subleader” communication pattern that balances the scalability needs with the robustness requirements under failures, (b) deployment of provable secure BLS multi-signatures, (c) use of deterministic thresh-old signatures as a source of randomness and (d) careful design of the reward allocation mechanism. We have implemented MOTORand compare it withByzCoin. We show that MOTORcan scale similar to ByzCoin with an at most2xoverhead whereas it maintains good performance even under high-percentage of faults, unlike ByzCoin.' article_number: 2019/676 article_processing_charge: No author: - first_name: Eleftherios full_name: Kokoris Kogias, Eleftherios id: f5983044-d7ef-11ea-ac6d-fd1430a26d30 last_name: Kokoris Kogias citation: ama: Kokoris Kogias E. Robust and scalable consensus for sharded distributed ledgers. Cryptology ePrint Archive. apa: Kokoris Kogias, E. (n.d.). Robust and scalable consensus for sharded distributed ledgers. Cryptology ePrint Archive. chicago: Kokoris Kogias, Eleftherios. “Robust and Scalable Consensus for Sharded Distributed Ledgers.” Cryptology EPrint Archive, n.d. ieee: E. Kokoris Kogias, “Robust and scalable consensus for sharded distributed ledgers,” Cryptology ePrint Archive. . ista: Kokoris Kogias E. Robust and scalable consensus for sharded distributed ledgers. Cryptology ePrint Archive, 2019/676. mla: Kokoris Kogias, Eleftherios. “Robust and Scalable Consensus for Sharded Distributed Ledgers.” Cryptology EPrint Archive, 2019/676. short: E. Kokoris Kogias, Cryptology EPrint Archive (n.d.). date_created: 2020-08-26T12:13:56Z date_published: 2019-06-06T00:00:00Z date_updated: 2021-09-24T12:07:11Z day: '06' extern: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://eprint.iacr.org/2019/676 month: '06' oa: 1 oa_version: Preprint publication: Cryptology ePrint Archive publication_status: submitted status: public title: Robust and scalable consensus for sharded distributed ledgers type: preprint user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2019' ... --- _id: '8304' abstract: - lang: eng text: "Enabling secure communication across distributed systems is usually studied under the assumption of trust between the different systems and an external adversary trying to compromise the messages. With the appearance of distributed ledgers or blockchains, numerous protocols have emerged, which attempt to achieve trustless communication between distrusting ledgers and participants. Cross-chain communication (CCC) thereby plays a fundamental role in cryptocurrency exchanges, sharding, bootstrapping of new and feature-extension of existing distributed ledgers. Unfortunately, existing proposals are designed ad-hoc for specific use-cases, making it hard to gain confidence on their correctness and composability.\r\nWe provide the first systematic exposition of protocols for CCC. First, we formalize the underlying research problem and show that CCC is impossible without a trusted third party, contrary to common beliefs in the blockchain community. We then develop a framework to evaluate existing and to design new cross-chain protocols. The framework is based on the use case, the trust model, and the security assumptions of interlinked blockchains. Finally, we identify security and privacy challenges faced by protocols in the cross-chain setting.\r\nThis Systematization of Knowledge (SoK) offers a comprehensive guide for designing protocols bridging the numerous distributed ledgers available today. It aims to facilitate clearer communication between academia and industry in the field." article_number: 2019/1128 article_processing_charge: No author: - first_name: Alexei full_name: Zamyatin, Alexei last_name: Zamyatin - first_name: Mustafa full_name: Al-Bassam, Mustafa last_name: Al-Bassam - first_name: Dionysis full_name: Zindros, Dionysis last_name: Zindros - first_name: Eleftherios full_name: Kokoris Kogias, Eleftherios id: f5983044-d7ef-11ea-ac6d-fd1430a26d30 last_name: Kokoris Kogias - first_name: Pedro full_name: Moreno-Sanchez, Pedro last_name: Moreno-Sanchez - first_name: Aggelos full_name: Kiayias, Aggelos last_name: Kiayias - first_name: William J. full_name: Knottenbelt, William J. last_name: Knottenbelt citation: ama: 'Zamyatin A, Al-Bassam M, Zindros D, et al. SoK: Communication across distributed ledgers. Cryptology ePrint Archive.' apa: 'Zamyatin, A., Al-Bassam, M., Zindros, D., Kokoris Kogias, E., Moreno-Sanchez, P., Kiayias, A., & Knottenbelt, W. J. (n.d.). SoK: Communication across distributed ledgers. Cryptology ePrint Archive.' chicago: 'Zamyatin, Alexei, Mustafa Al-Bassam, Dionysis Zindros, Eleftherios Kokoris Kogias, Pedro Moreno-Sanchez, Aggelos Kiayias, and William J. Knottenbelt. “SoK: Communication across Distributed Ledgers.” Cryptology EPrint Archive, n.d.' ieee: 'A. Zamyatin et al., “SoK: Communication across distributed ledgers,” Cryptology ePrint Archive. .' ista: 'Zamyatin A, Al-Bassam M, Zindros D, Kokoris Kogias E, Moreno-Sanchez P, Kiayias A, Knottenbelt WJ. SoK: Communication across distributed ledgers. Cryptology ePrint Archive, 2019/1128.' mla: 'Zamyatin, Alexei, et al. “SoK: Communication across Distributed Ledgers.” Cryptology EPrint Archive, 2019/1128.' short: A. Zamyatin, M. Al-Bassam, D. Zindros, E. Kokoris Kogias, P. Moreno-Sanchez, A. Kiayias, W.J. Knottenbelt, Cryptology EPrint Archive (n.d.). date_created: 2020-08-26T12:16:38Z date_published: 2019-10-01T00:00:00Z date_updated: 2021-09-24T12:08:14Z day: '01' extern: '1' language: - iso: eng main_file_link: - open_access: '1' url: 'https://eprint.iacr.org/2019/1128 ' month: '10' oa: 1 oa_version: Preprint publication: Cryptology ePrint Archive publication_status: submitted status: public title: 'SoK: Communication across distributed ledgers' type: preprint user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9 year: '2019' ... --- _id: '8305' abstract: - lang: eng text: In this paper, we present the first fully asynchronous distributed key generation (ADKG) algorithm as well as the first distributed key generation algorithm that can create keys with a dual (f,2f+1)−threshold that are necessary for scalable consensus (which so far needs a trusted dealer assumption). In order to create a DKG with a dual (f,2f+1)− threshold we first answer in the affirmative the open question posed by Cachin et al. how to create an AVSS protocol with recovery thresholds f+1