{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,5,2]],"date-time":"2025-05-02T16:48:38Z","timestamp":1746204518087,"version":"3.40.2"},"reference-count":0,"publisher":"SAGE Publications","issue":"5-6","license":[{"start":{"date-parts":[[2012,1,1]],"date-time":"2012-01-01T00:00:00Z","timestamp":1325376000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["In Silico Biology: Journal of Biological Systems Modeling and Multi-Scale Simulation"],"published-print":{"date-parts":[[2012,11]]},"abstract":"<jats:p>\n            Influenza A viruses have been responsible for large losses of lives around the world and\n          continue to present a great public health challenge. In April 2009, a novel swine-origin\n          H1N1 virus emerged in North America and caused the first pandemic of the 21\n            <jats:sup>st<\/jats:sup>\n            century. Toward the end of 2009, two waves of outbreaks occurred, and then the disease\n          moderated. It will be critical to understand how this novel pandemic virus invaded and\n          adapted to a human population. To understand the molecular dynamics and evolution in this\n          pandemic H1N1 virus, we applied an Expectation-Maximization algorithm to estimate the\n          Gaussian mixture in the genetic population of the hemagglutinin (HA) gene of these H1N1\n          viruses from April of 2009 to January of 2010 and compared them with the viruses that\n          cause seasonal H1N1 influenza. Our results show that, after it was introduced to human\n          population, the 2009 H1N1 viral HA gene changed its population structure from a single\n          Gaussian distribution to two major Gaussian distributions. The breadths of HA genetic\n          diversity of 2009 H1N1 virus also increased from the first wave to the second wave of this\n          pandemic. Phylogenetic analyses demonstrated that only certain HA sublineages of 2009 H1N1\n          viruses were able to circulate throughout the pandemic period. In contrast, the influenza\n          HA population structure of seasonal H1N1 virus was relatively stable, and the breadth of\n          HA genetic diversity within a single season population remained similar. This study\n          revealed an evolutionary mechanism for a novel pandemic virus. After the virus is\n          introduced to human population, the influenza virus would expand their molecular diversity\n          through both random mutations (genetic drift) and selections. Eventually, multiple levels\n          of hierarchical Gaussian distributions will replace the earlier single distribution. An\n          evolutionary model for pandemic H1N1 influenza A virus was proposed and demonstrated with\n          a simulation.\n          <\/jats:p>","DOI":"10.3233\/isb-2012-0457","type":"journal-article","created":{"date-parts":[[2025,1,20]],"date-time":"2025-01-20T11:05:27Z","timestamp":1737371127000},"page":"225-236","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["Mixture model analysis reflecting dynamics of the population diversity of          2009 pandemic H1N1 influenza virus"],"prefix":"10.1177","volume":"11","author":[{"given":"Li-Ping","family":"Long","sequence":"first","affiliation":[{"name":"Department of Basic Sciences, College of Veterinary Medicine, Mississippi\r          State University, Starkville, MS, USA"}]},{"given":"Changhe","family":"Yuan","sequence":"additional","affiliation":[{"name":"Department of Computer Science, Queens College\/City University of New York,\r          New York, NY, USA"}]},{"given":"Zhipeng","family":"Cai","sequence":"additional","affiliation":[{"name":"Department of Basic Sciences, College of Veterinary Medicine, Mississippi\r          State University, Starkville, MS, USA"}]},{"given":"Huiping","family":"Xu","sequence":"additional","affiliation":[{"name":"Division of Biostatistics, Department of Medicine, School of Medicine,\r          Indiana University, Bloomington, IN, USA"}]},{"given":"Xiu-Feng","family":"Wan","sequence":"additional","affiliation":[{"name":"Department of Basic Sciences, College of Veterinary Medicine, Mississippi\r          State University, Starkville, MS, USA"}]}],"member":"179","published-online":{"date-parts":[[2012,1]]},"container-title":["In Silico Biology: Journal of Biological Systems Modeling and Multi-Scale Simulation"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.3233\/ISB-2012-0457","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.3233\/ISB-2012-0457","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,21]],"date-time":"2025-03-21T14:33:45Z","timestamp":1742567625000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.3233\/ISB-2012-0457"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,1]]},"references-count":0,"journal-issue":{"issue":"5-6","published-print":{"date-parts":[[2012,11]]}},"alternative-id":["10.3233\/ISB-2012-0457"],"URL":"https:\/\/doi.org\/10.3233\/isb-2012-0457","relation":{},"ISSN":["1386-6338","1434-3207"],"issn-type":[{"type":"print","value":"1386-6338"},{"type":"electronic","value":"1434-3207"}],"subject":[],"published":{"date-parts":[[2012,1]]}}}