ORCID Profile
0000-0003-0087-3015
Current Organisation
Massey University
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Publisher: Cold Spring Harbor Laboratory
Date: 28-07-2023
DOI: 10.1101/2023.07.26.23293210
Abstract: The speed of spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the coronavirus disease 2019 (COVID-19) pandemic highlights the importance of understanding how infections are transmitted in a highly connected world. Prior to vaccination, changes in human mobility patterns were used as non-pharmaceutical interventions to eliminate or suppress viral transmission. The rapid spread of respiratory viruses, various intervention approaches, and the global dissemination of SARS-CoV-2 underscore the necessity for epidemiological models that incorporate mobility to comprehend the spread of the virus. Here, we introduce a metapopulation susceptible–exposed–infectious–recovered (SEIR) model parameterised with human movement data from 340 cities in China. Our model replicates the early case trajectory in the COVID-19 pandemic. We then use machine learning algorithms to determine which network properties best predict spread between cities and find travel time to be most important, followed by the human movement Weighted Personalised PageRank. However, we show that travel time is most influential locally, after which the high connectivity between cities reduces the impact of travel time between in idual cities on transmission speed. Additionally, we demonstrate that only significantly reduced movement substantially impacts infection spread times throughout the network.
Publisher: Cold Spring Harbor Laboratory
Date: 27-08-2023
DOI: 10.1101/2023.08.25.554763
Abstract: Wild bovids provide important ecosystem services throughout their native range. In Asia, most are threatened with extinction. Five wild bovids remain in Thailand: gaur ( Bos gaurus ), banteng ( Bos javanicus ), wild water buffalo ( Bubalus arnee ), mainland serow ( Capricornis sumatraensis ) and Chinese goral ( Naemorhedus griseus ). However, their populations and habitats have declined substantially and become fragmented. Here, we identified potentially suitable habitat for these five threatened bovids using ecological niche models, first throughout the species entire distribution and second within Thailand, and quantified how much suitable area remains within protected areas. We combined species occurrence data with 28 environmental variables for modelling and used a spatially-restricted Biotic-Abiotic-Mobility framework for two accessible areas: 1) species-specific accessible areas and 2) a single large accessible area. We applied spatially restricted and weighted average ensembles from eight algorithms when generating maps. For B. gaurus and B. javanicus, the best models predicted suitable habitat was mostly within Southeast Asia, with B. gaurus having predicted large areas in Thailand and India. B. arnee suitable habitat was mostly in India. C. sumatraensis suitable habitat was mostly in Thailand and Myanmar. N. griseus was mainly restricted to China. In Thailand, the highest bovid potential richnesses were in the Northern Forest, Western Forest, Eastern Forest and Dong Phayayen-Khao Yai Forest Complexes. We identified unprotected hotspots with % of overall suitable habitat located outside protected areas. B. arnee had the smallest proportion of protected habitat (9%). Suitable areas identified in and out protected areas may guide habitat management and conflict mitigation strategies.
Publisher: Springer Science and Business Media LLC
Date: 03-2018
DOI: 10.1038/S41598-018-22236-6
Abstract: Spatiotemporally-localised prediction of virus emergence from wildlife requires focused studies on the ecology and immunology of reservoir hosts in their native habitat. Reliable predictions from mathematical models remain difficult in most systems due to a dearth of appropriate empirical data. Our goal was to study the circulation and immune dynamics of zoonotic viruses in bat populations and investigate the effects of maternally-derived and acquired immunity on viral persistence. Using rare age-specific serological data from wild-caught Eidolon helvum fruit bats as a case study, we estimated viral transmission parameters for a stochastic infection model. We estimated mean durations of around 6 months for maternally-derived immunity to Lagos bat virus and African henipavirus, whereas acquired immunity was long-lasting (Lagos bat virus: mean 12 years, henipavirus: mean 4 years). In the presence of a seasonal birth pulse, the effect of maternally-derived immunity on virus persistence within modelled bat populations was highly dependent on transmission characteristics. To explain previous reports of viral persistence within small natural and captive E. helvum populations, we hypothesise that some bats must experience prolonged infectious periods or within-host latency. By further elucidating plausible mechanisms of virus persistence in bat populations, we contribute to guidance of future field studies.
Publisher: Public Library of Science (PLoS)
Date: 03-09-2020
Publisher: Springer Science and Business Media LLC
Date: 03-01-2023
Publisher: Public Library of Science (PLoS)
Date: 12-06-2018
Publisher: Public Library of Science (PLoS)
Date: 05-10-2023
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for David Hayman.