{"675330":{"#nid":"675330","#data":{"type":"event","title":"PhD Defense by Roth Conrad","body":[{"value":"\u003Cp\u003EIn partial fulfillment of the requirements for the degree of\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDoctor of Philosophy in Ocean Science \u0026amp; Engineering\u003C\/p\u003E\u003Cp\u003EIn the\u003C\/p\u003E\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ERoth Conrad\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EWill defend his dissertation\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EToward Advancing the Definitions of Sequence-Discrete Prokaryotic Species and Intra-Species Units, and Quantifying Their Distribution Patterns in Marine Environments\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EThursday, July 18th, 2024\u003C\/p\u003E\u003Cp\u003E3 PM\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E(online only)\u003C\/p\u003E\u003Cp\u003EZoom:\u0026nbsp;\u003Ca href=\u0022https:\/\/gatech.zoom.us\/j\/91370832525\u0022\u003Ehttps:\/\/gatech.zoom.us\/j\/91370832525\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003Cstrong\u003EThesis Advisor:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EKonstantinos (Kostas) Konstantinidis, Ph.D.\u003C\/p\u003E\u003Cp\u003ECivil and Environmental Engineering\u003C\/p\u003E\u003Cp\u003E\u0026amp; School of Biological Sciences (by courtesy)\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr. Joel Kostka, Ph.D.\u003C\/p\u003E\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\u003Cp\u003E\u0026amp; School of Earth and Atmospheric Sciences\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDr. Thomas DiChristina, Ph.D.\u003C\/p\u003E\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDr. Thomas DiChristina, Ph.D.\u003C\/p\u003E\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDr. Frank Stewart\u003C\/p\u003E\u003Cp\u003EDepartment of Microbiology \u0026amp; Cell Biology\u003C\/p\u003E\u003Cp\u003EMontana State University\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EDr. Andrew Huang\u003C\/p\u003E\u003Cp\u003EThe Centers for Disease Control (CDC)\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EABSTRACT: Although sequence-discrete species appear to dominate natural microbial communities, the mechanism(s) that maintain such species and whether or not discrete intra-species units exist represent unanswered questions with major practical implications for communicating about microbial diversity. In this thesis, novel analytical approaches were developed to answer these questions, including a method to identified recently recombined genes between genomes. Application of this method to the 330 best sampled bacterial species by genome sequences identified a new intra-species ANI discontinuity between 99.2% and 99.8% (midpoint 99.5%) that can be used to identify genomovars (\u0026gt;99.5% ANI) and strains (\u0026gt;99.99% ANI) more reliably and robustly than the current practice. Further, this analysis showed that high ecological cohesiveness and unbiased horizontal gene flow, mediated by homologous recombination, underpin the sequence-discrete species and intra-species units. We also developed a new algorithm, employing the kernel density estimation (KDE) and a peak finding module, to determine when a population is identical or not between two metagenomes based on a read recruitment plot against a representative genome of the population. Application of this algorithm to available marine metagenomes allowed us to quantify how populations within a species diverge between ocean depths and basins and, interestingly, identified a few populations that are truly cosmopolitan across depths in the Gulf of Mexico. Therefore, this thesis provided novel means to integrated genomic and metagenomic data for identifying and tracking microbial species and intra-species units in situ, and has answered a major question for microbiology; that is, what is a species and what a strain.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u003Cstrong\u003EToward Advancing the Definitions of Sequence-Discrete Prokaryotic Species and Intra-Species Units, and Quantifying Their Distribution Patterns in Marine Environments\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Toward Advancing the Definitions of Sequence-Discrete Prokaryotic Species and Intra-Species Units, and Quantifying Their Distribution Patterns in Marine Environments"}],"uid":"27707","created_gmt":"2024-07-03 13:02:54","changed_gmt":"2024-07-03 13:07:05","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2024-07-18T15:00:00-04:00","event_time_end":"2024-07-18T17:00:00-04:00","event_time_end_last":"2024-07-18T17:00:00-04:00","gmt_time_start":"2024-07-18 19:00:00","gmt_time_end":"2024-07-18 21:00:00","gmt_time_end_last":"2024-07-18 21:00:00","rrule":null,"timezone":"America\/New_York"},"location":"ZOOM","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}