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  1. Article ; Online: Bayesian phylodynamic inference with complex models.

    Volz, Erik M / Siveroni, Igor

    PLoS computational biology

    2018  Volume 14, Issue 11, Page(s) e1006546

    Abstract: Population genetic modeling can enhance Bayesian phylogenetic inference by providing a realistic prior on the distribution of branch lengths and times of common ancestry. The parameters of a population genetic model may also have intrinsic importance, ... ...

    Abstract Population genetic modeling can enhance Bayesian phylogenetic inference by providing a realistic prior on the distribution of branch lengths and times of common ancestry. The parameters of a population genetic model may also have intrinsic importance, and simultaneous estimation of a phylogeny and model parameters has enabled phylodynamic inference of population growth rates, reproduction numbers, and effective population size through time. Phylodynamic inference based on pathogen genetic sequence data has emerged as useful supplement to epidemic surveillance, however commonly-used mechanistic models that are typically fitted to non-genetic surveillance data are rarely fitted to pathogen genetic data due to a dearth of software tools, and the theory required to conduct such inference has been developed only recently. We present a framework for coalescent-based phylogenetic and phylodynamic inference which enables highly-flexible modeling of demographic and epidemiological processes. This approach builds upon previous structured coalescent approaches and includes enhancements for computational speed, accuracy, and stability. A flexible markup language is described for translating parametric demographic or epidemiological models into a structured coalescent model enabling simultaneous estimation of demographic or epidemiological parameters and time-scaled phylogenies. We demonstrate the utility of these approaches by fitting compartmental epidemiological models to Ebola virus and Influenza A virus sequence data, demonstrating how important features of these epidemics, such as the reproduction number and epidemic curves, can be gleaned from genetic data. These approaches are provided as an open-source package PhyDyn for the BEAST2 phylogenetics platform.
    MeSH term(s) Africa, Western/epidemiology ; Bayes Theorem ; Computer Simulation ; Epidemics ; Genetics, Population ; Hemorrhagic Fever, Ebola/epidemiology ; Humans ; Influenza, Human/epidemiology ; Models, Theoretical ; Phylogeny ; Population Surveillance ; Seasons ; Software Design
    Language English
    Publishing date 2018-11-13
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2193340-6
    ISSN 1553-7358 ; 1553-734X
    ISSN (online) 1553-7358
    ISSN 1553-734X
    DOI 10.1371/journal.pcbi.1006546
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Additive Uncorrelated Relaxed Clock Models for the Dating of Genomic Epidemiology Phylogenies.

    Didelot, Xavier / Siveroni, Igor / Volz, Erik M

    Molecular biology and evolution

    2020  Volume 38, Issue 1, Page(s) 307–317

    Abstract: Phylogenetic dating is one of the most powerful and commonly used methods of drawing epidemiological interpretations from pathogen genomic data. Building such trees requires considering a molecular clock model which represents the rate at which ... ...

    Abstract Phylogenetic dating is one of the most powerful and commonly used methods of drawing epidemiological interpretations from pathogen genomic data. Building such trees requires considering a molecular clock model which represents the rate at which substitutions accumulate on genomes. When the molecular clock rate is constant throughout the tree then the clock is said to be strict, but this is often not an acceptable assumption. Alternatively, relaxed clock models consider variations in the clock rate, often based on a distribution of rates for each branch. However, we show here that the distributions of rates across branches in commonly used relaxed clock models are incompatible with the biological expectation that the sum of the numbers of substitutions on two neighboring branches should be distributed as the substitution number on a single branch of equivalent length. We call this expectation the additivity property. We further show how assumptions of commonly used relaxed clock models can lead to estimates of evolutionary rates and dates with low precision and biased confidence intervals. We therefore propose a new additive relaxed clock model where the additivity property is satisfied. We illustrate the use of our new additive relaxed clock model on a range of simulated and real data sets, and we show that using this new model leads to more accurate estimates of mean evolutionary rates and ancestral dates.
    MeSH term(s) Evolution, Molecular ; Genome, Bacterial ; Models, Genetic ; Mutation ; Phylogeny
    Language English
    Publishing date 2020-07-27
    Publishing country United States
    Document type Comparative Study ; Evaluation Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 998579-7
    ISSN 1537-1719 ; 0737-4038
    ISSN (online) 1537-1719
    ISSN 0737-4038
    DOI 10.1093/molbev/msaa193
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Book ; Conference proceedings: Static analysis

    Hankin, Chris / Siveroni, Igor

    12th international symposium, SAS 2005, London, UK, September 7 - 9, 2005 ; proceedings

    (Lecture notes in computer science ; 3672)

    2005  

    Institution SAS
    Event/congress International Static Analysis Symposium (12, 2005.09.07-09, London) ; International Symposium on Static Analysis (12, 2005.09.07-09, London) ; SAS 2005 (12, 2005.09.07-09, London)
    Author's details Chris Hankin; Igor Siveroni (ed.)
    Series title Lecture notes in computer science ; 3672
    Keywords Computer programming ; Langages de programmation ; Programmation (Informatique) ; Programming languages (Electronic computers)
    Language English
    Size X, 367 S, graph. Darst, 235 mm x 155 mm
    Publisher Springer
    Publishing place Berlin u.a.
    Document type Book ; Conference proceedings
    Note Literaturangaben
    ISBN 3540285849 ; 9783540285847
    Database Former special subject collection: coastal and deep sea fishing

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  4. Book ; Conference proceedings: Static analysis

    Hankin, Chris / Siveroni, Igor

    12th international symposium, SAS 2005, London, UK, September 7 - 9, 2005 ; proceedings

    (Lecture notes in computer science ; 3672)

    2005  

    Institution SAS
    Event/congress International Static Analysis Symposium (12, 2005.09.07-09, London) ; International Symposium on Static Analysis (12, 2005.09.07-09, London) ; SAS 2005 (12, 2005.09.07-09, London)
    Author's details Chris Hankin; Igor Siveroni (ed.)
    Series title Lecture notes in computer science ; 3672
    Keywords Computer programming ; Langages de programmation ; Programmation (Informatique) ; Programming languages (Electronic computers)
    Language English
    Size X, 367 S, graph. Darst, 235 mm x 155 mm
    Publisher Springer
    Publishing place Berlin u.a.
    Document type Book ; Conference proceedings
    Note Literaturangaben
    ISBN 3540285849 ; 9783540285847
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  5. Book ; Online ; Conference proceedings: Static analysis

    Hankin, Chris / Siveroni, Igor

    12th international symposium, SAS 2005, London, UK, September 7 - 9, 2005 ; proceedings

    (Lecture notes in computer science ; 3672)

    2005  

    Institution SAS
    Event/congress International Static Analysis Symposium (12, 2005.09.07-09, London) ; International Symposium on Static Analysis (12, 2005.09.07-09, London) ; SAS 2005 (12, 2005.09.07-09, London)
    Author's details Chris Hankin; Igor Siveroni (ed.)
    Series title Lecture notes in computer science ; 3672
    Keywords Computer programming ; Programming languages (Electronic computers)
    Language English
    Size Online-Ressource (X, 367 S.), graph. Darst
    Publisher Springer
    Publishing place Berlin u.a.
    Document type Book ; Online ; Conference proceedings
    Note Literaturangaben
    ISBN 3540285849 ; 9783540285847
    DOI 10.1007/11547662
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  6. Book ; Conference proceedings ; Online: Static analysis

    Hankin, Chris / Siveroni, Igor

    12th international symposium, SAS 2005, London, UK, September 7 - 9, 2005 ; proceedings

    (Lecture notes in computer science ; 3672)

    2005  

    Institution SAS
    Event/congress International Static Analysis Symposium (12, 2005.09.07-09, London) ; International Symposium on Static Analysis (12, 2005.09.07-09, London) ; SAS 2005 (12, 2005.09.07-09, London)
    Author's details Chris Hankin; Igor Siveroni (ed.)
    Series title Lecture notes in computer science ; 3672
    Keywords Computer programming ; Programming languages (Electronic computers)
    Language English
    Size Online-Ressource (X, 367 S.), graph. Darst
    Publisher Springer
    Publishing place Berlin u.a.
    Document type Book ; Conference proceedings ; Online
    Note Literaturangaben
    ISBN 3540285849 ; 9783540285847
    DOI 10.1007/11547662
    Database Former special subject collection: coastal and deep sea fishing

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  7. Article ; Online: Genetic evidence for the association between COVID-19 epidemic severity and timing of non-pharmaceutical interventions.

    Ragonnet-Cronin, Manon / Boyd, Olivia / Geidelberg, Lily / Jorgensen, David / Nascimento, Fabricia F / Siveroni, Igor / Johnson, Robert A / Baguelin, Marc / Cucunubá, Zulma M / Jauneikaite, Elita / Mishra, Swapnil / Watson, Oliver J / Ferguson, Neil / Cori, Anne / Donnelly, Christl A / Volz, Erik

    Nature communications

    2021  Volume 12, Issue 1, Page(s) 2188

    Abstract: Unprecedented public health interventions including travel restrictions and national lockdowns have been implemented to stem the COVID-19 epidemic, but the effectiveness of non-pharmaceutical interventions is still debated. We carried out a phylogenetic ... ...

    Abstract Unprecedented public health interventions including travel restrictions and national lockdowns have been implemented to stem the COVID-19 epidemic, but the effectiveness of non-pharmaceutical interventions is still debated. We carried out a phylogenetic analysis of more than 29,000 publicly available whole genome SARS-CoV-2 sequences from 57 locations to estimate the time that the epidemic originated in different places. These estimates were examined in relation to the dates of the most stringent interventions in each location as well as to the number of cumulative COVID-19 deaths and phylodynamic estimates of epidemic size. Here we report that the time elapsed between epidemic origin and maximum intervention is associated with different measures of epidemic severity and explains 11% of the variance in reported deaths one month after the most stringent intervention. Locations where strong non-pharmaceutical interventions were implemented earlier experienced much less severe COVID-19 morbidity and mortality during the period of study.
    MeSH term(s) COVID-19/diagnosis ; COVID-19/epidemiology ; COVID-19/virology ; Communicable Disease Control/methods ; Epidemics ; Humans ; Phylogeny ; Phylogeography/methods ; Public Health/methods ; Public Health/statistics & numerical data ; SARS-CoV-2/classification ; SARS-CoV-2/genetics ; SARS-CoV-2/physiology ; Severity of Illness Index
    Language English
    Publishing date 2021-04-12
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-021-22366-y
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Genomic epidemiology of a densely sampled COVID-19 outbreak in China.

    Geidelberg, Lily / Boyd, Olivia / Jorgensen, David / Siveroni, Igor / Nascimento, Fabrícia F / Johnson, Robert / Ragonnet-Cronin, Manon / Fu, Han / Wang, Haowei / Xi, Xiaoyue / Chen, Wei / Liu, Dehui / Chen, Yingying / Tian, Mengmeng / Tan, Wei / Zai, Junjie / Sun, Wanying / Li, Jiandong / Li, Junhua /
    Volz, Erik M / Li, Xingguang / Nie, Qing

    Virus evolution

    2021  Volume 7, Issue 1, Page(s) veaa102

    Abstract: Analysis of genetic sequence data from the SARS-CoV-2 pandemic can provide insights into epidemic origins, worldwide dispersal, and epidemiological history. With few exceptions, genomic epidemiological analysis has focused on geographically distributed ... ...

    Abstract Analysis of genetic sequence data from the SARS-CoV-2 pandemic can provide insights into epidemic origins, worldwide dispersal, and epidemiological history. With few exceptions, genomic epidemiological analysis has focused on geographically distributed data sets with few isolates in any given location. Here, we report an analysis of 20 whole SARS- CoV-2 genomes from a single relatively small and geographically constrained outbreak in Weifang, People's Republic of China. Using Bayesian model-based phylodynamic methods, we estimate a mean basic reproduction number (
    Language English
    Publishing date 2021-03-14
    Publishing country England
    Document type Journal Article
    ZDB-ID 2818949-8
    ISSN 2057-1577
    ISSN 2057-1577
    DOI 10.1093/ve/veaa102
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: COVID-19 epidemic severity is associated with timing of non-pharmaceutical interventions

    Ragonnet-Cronin, Manon / Boyd, Olivia / Geidelberg, Lily / Jorgensen, David / Nascimento, Fabricia F / Siveroni, Igor / Johnson, Robert / Baguelin, Marc / Cucunuba, Zulma M / Jauneikaite, Elita / Mishra, Swapnil / Thompson, Hayley A / Watson, Oliver J / Ferguson, Neil / Donnelly, Christl A / Volz, Erik

    medRxiv

    Abstract: Background: Unprecedented public health interventions including travel restrictions and national lockdowns have been implemented to stem the COVID-19 epidemic, but the effectiveness of non-pharmaceutical interventions is still debated. International ... ...

    Abstract Background: Unprecedented public health interventions including travel restrictions and national lockdowns have been implemented to stem the COVID-19 epidemic, but the effectiveness of non-pharmaceutical interventions is still debated. International comparisons are hampered by highly variable conditions under which epidemics spread and differences in the timing and scale of interventions. Cumulative COVID-19 morbidity and mortality are functions of both the rate of epidemic growth and the duration of uninhibited growth before interventions were implemented. Incomplete and sporadic testing during the early COVID-19 epidemic makes it difficult to identify how long SARS-CoV-2 was circulating in different places. SARS-CoV-2 genetic sequences can be analyzed to provide an estimate of both the time of epidemic origin and the rate of early epidemic growth in different settings. Methods: We carried out a phylogenetic analysis of more than 29,000 publicly available whole genome SARS-CoV-2 sequences from 57 locations to estimate the time that the epidemic originated in different places. These estimates were cross-referenced with dates of the most stringent interventions in each location as well as the number of cumulative COVID-19 deaths following maximum intervention. Phylodynamic methods were used to estimate the rate of early epidemic growth and proxy estimates of epidemic size. Findings: The time elapsed between epidemic origin and maximum intervention is strongly associated with different measures of epidemic severity and explains 46% of variance in numbers infected at time of maximum intervention. The reproduction number is independently associated with epidemic severity. In multivariable regression models, epidemic severity was not associated with census population size. The time elapsed between detection of initial COVID-19 cases to interventions was not associated with epidemic severity, indicating that many locations experienced long periods of cryptic transmission. Interpretation: Locations where strong non-pharmaceutical interventions were implemented earlier experienced much less severe COVID-19 morbidity and mortality during the period of study.
    Keywords covid19
    Language English
    Publishing date 2020-09-18
    Publisher Cold Spring Harbor Laboratory Press
    Document type Article ; Online
    DOI 10.1101/2020.09.15.20194258
    Database COVID19

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  10. Article ; Online: BEAST 2.5: An advanced software platform for Bayesian evolutionary analysis.

    Bouckaert, Remco / Vaughan, Timothy G / Barido-Sottani, Joëlle / Duchêne, Sebastián / Fourment, Mathieu / Gavryushkina, Alexandra / Heled, Joseph / Jones, Graham / Kühnert, Denise / De Maio, Nicola / Matschiner, Michael / Mendes, Fábio K / Müller, Nicola F / Ogilvie, Huw A / du Plessis, Louis / Popinga, Alex / Rambaut, Andrew / Rasmussen, David / Siveroni, Igor /
    Suchard, Marc A / Wu, Chieh-Hsi / Xie, Dong / Zhang, Chi / Stadler, Tanja / Drummond, Alexei J

    PLoS computational biology

    2019  Volume 15, Issue 4, Page(s) e1006650

    Abstract: Elaboration of Bayesian phylogenetic inference methods has continued at pace in recent years with major new advances in nearly all aspects of the joint modelling of evolutionary data. It is increasingly appreciated that some evolutionary questions can ... ...

    Abstract Elaboration of Bayesian phylogenetic inference methods has continued at pace in recent years with major new advances in nearly all aspects of the joint modelling of evolutionary data. It is increasingly appreciated that some evolutionary questions can only be adequately answered by combining evidence from multiple independent sources of data, including genome sequences, sampling dates, phenotypic data, radiocarbon dates, fossil occurrences, and biogeographic range information among others. Including all relevant data into a single joint model is very challenging both conceptually and computationally. Advanced computational software packages that allow robust development of compatible (sub-)models which can be composed into a full model hierarchy have played a key role in these developments. Developing such software frameworks is increasingly a major scientific activity in its own right, and comes with specific challenges, from practical software design, development and engineering challenges to statistical and conceptual modelling challenges. BEAST 2 is one such computational software platform, and was first announced over 4 years ago. Here we describe a series of major new developments in the BEAST 2 core platform and model hierarchy that have occurred since the first release of the software, culminating in the recent 2.5 release.
    MeSH term(s) Animals ; Bayes Theorem ; Biological Evolution ; Computational Biology ; Computer Simulation ; Evolution, Molecular ; Humans ; Markov Chains ; Models, Genetic ; Monte Carlo Method ; Phylogeny ; Software
    Language English
    Publishing date 2019-04-08
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Validation Study
    ZDB-ID 2193340-6
    ISSN 1553-7358 ; 1553-734X
    ISSN (online) 1553-7358
    ISSN 1553-734X
    DOI 10.1371/journal.pcbi.1006650
    Database MEDical Literature Analysis and Retrieval System OnLINE

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