{"536821":{"#nid":"536821","#data":{"type":"news","title":"Dr. Sam Brown Awarded  $600K","body":[{"value":"\u003Cp\u003EDr. Sam Brown, Associate Professor of Biology, was just awarded a $600K, 3 year grant from the Simons Foundation for a project entitled \u201c\u003Cem\u003EHow do quorum-sensing bacteria sense and respond to their social and physical environment?\u003C\/em\u003E\u003Cem\u003E\u201d\u003C\/em\u003EThis project investigates collective decision making in bacteria by exploring how bacteria collectively sense and respond to their environment via a form of cell-cell communication known as quorum-sensing (QS). Despite the widespread interest in QS from molecular mechanisms to social evolution and pathogen control, there is still controversy over the basic evolutionary function of QS \u2013 in short, \u003Cem\u003Ewhy \u003C\/em\u003Edo bacteria use QS? The standard answer is that cells produce extracellular signals to serve as a proxy for cell density \u2013 more signal implies more bacteria. However, inferences to density can be confounded as signal concentration will also vary with changes in the physical environment (diffusion, flow) and other aspects\u0026nbsp; of\u0026nbsp; social\u0026nbsp; organization\u0026nbsp; (spatial\u0026nbsp; patterning,\u0026nbsp; genotypic\u0026nbsp; mixing),\u0026nbsp; leading\u0026nbsp; to\u0026nbsp; a\u0026nbsp; list of alternative hypotheses (e.g. diffusion, efficiency, and genotype sensing).\u003C\/p\u003E\u003Cp\u003ECurrent functional hypotheses and mathematical models focus on the limits of inference to physical and\/or social environmental variation, given the production and sensing of a single signal\u0026nbsp; type.\u0026nbsp; However,\u0026nbsp; molecular\u0026nbsp; characterization\u0026nbsp; of\u0026nbsp; QS\u0026nbsp; systems\u0026nbsp; often\u0026nbsp; reveals\u0026nbsp; the\u0026nbsp; use \u0026nbsp;of\u003C\/p\u003E\u003Cp\u003Emultiple distinct extracellular signal molecules. To overcome this persistent gap between\u003C\/p\u003E\u003Cp\u003Efunctional hypotheses and molecular mechanism we will develop and test theory on the functional roles and limits of multi-signal QS, using the widely studied environmental generalist microbe \u003Cem\u003EPseudomonas aeruginosa \u003C\/em\u003E(PA)\u003Cem\u003E. \u003C\/em\u003EOur central hypotheses are that QS bacteria can \u003Cstrong\u003E(1) \u003C\/strong\u003Esimultaneously resolve their social and physical environment, via non-linear processing of multiple signals with differing environmental properties and \u003Cstrong\u003E(2) \u003C\/strong\u003Euse simple signal-mediated rules to limit collective behaviors to clonal high density, low diffusion, low flow environments. The proposed research will leverage Georgia Tech\u2019s expertise in spatial math modeling, \u2018lab-on- a-chip\u2019 environmental manipulation, high-throughput microbial imaging and evolutionary microbiology.\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Dr. Sam Brown Awarded  $600K"}],"uid":"27964","created_gmt":"2016-05-17 15:12:24","changed_gmt":"2016-10-08 03:21:42","author":"Jasmine Martin","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2016-05-17T00:00:00-04:00","iso_date":"2016-05-17T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"536801":{"id":"536801","type":"image","title":"Sam Brown","body":null,"created":"1463713200","gmt_created":"2016-05-20 03:00:00","changed":"1475895322","gmt_changed":"2016-10-08 02:55:22","alt":"Sam Brown","file":{"fid":"88845","name":"brown.sam_.jpeg","image_path":"\/sites\/default\/files\/images\/brown.sam_.jpeg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/brown.sam_.jpeg","mime":"image\/jpeg","size":29680,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/brown.sam_.jpeg?itok=U5iz8-sD"}}},"media_ids":["536801"],"groups":[{"id":"1275","name":"School of Biological Sciences"}],"categories":[{"id":"146","name":"Life Sciences and Biology"}],"keywords":[{"id":"167225","name":"Sam Brown"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"}],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}