<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class="">Dear Soft Matter Colleagues and Friends,</font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;"><font face="HelveticaNeue" class=""><br class=""></font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class=""><font class="">On Friday 25 November 2022 at 9:30 AM at the UW Faculty of Physics (Pasteura 5, Warsaw;<b class=""> </b></font><b class="">room 1.40</b>) we are hosting a seminar during which</font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;"><font face="HelveticaNeue" class=""><br class=""></font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class=""><b class="">Bartłomiej Wacław </b><span class="">(University of Edinburgh & IChF PAN)</span></font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;"><font face="HelveticaNeue" class=""><br class=""></font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class="">will give a talk</font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal; min-height: 14px;"><font face="HelveticaNeue" class=""><br class=""></font></div><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class=""><b class="">Mechanical interactions affect biological evolution of bacteria<span class="Apple-tab-span" style="white-space:pre"> </span></b></font></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal;"><b class=""><br class=""></b></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal;"><b class="">Abstract</b></div><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><div class="" style="margin: 0cm; background-color: white;"><font face="HelveticaNeue" class="">Biofilms – surface-attached bacterial conglomerates – are not only ubiquitous in nature but also play a major role in industry and medicine, where biofilm growth on implants and catheters, and the evolution of antibiotic resistance is a concern. In the last ten years, thanks to the work of researchers from the soft-matter and statistical physics community (including our group), we have learned that mechanical interactions between bacterial cells and the surface on which they grow affect the shape of bacterial colonies [1,2] and population dynamics of novel genetic variants (mutations) in such colonies. This has been mostly investigated in bacterial colonies grown on agarose gel. When a colony is initiated with a mixture of two different fluorescent microbial strains, radial expansion and random fluctuations in the number of bacteria at the edge of the colony lead to the formation of “sectors” of genetically related bacteria. In this presentation, I will focus on how cell shape, cell-cell and cell-substrate adhesion and friction affect the probability that a faster-growing mutant ‘surfs’ at the colony’s frontier and creates a macroscopic sector. Although all these physical factors contribute to the surfing probability in seemingly different ways, I will show that they do it by affecting two key parameters that in turn influence the surfing probability: front roughness and cell alignment. These properties can be modified by chemical compounds that affect the bacteria and/or the surface, as well as by patterning the surface in a special way. Our work suggests a possible new approach to fighting persistent biofilms: the physical properties of bacterial cells could be targeted alongside standard antimicrobial therapy to kill the bacteria while at the same time reducing the probability of evolving resistance to antibiotics. </font></div><div class="" style="margin: 0cm; background-color: white;"><font face="HelveticaNeue" class=""><br class=""></font></div><div class="" style="margin: 0cm; background-color: white;"><font face="HelveticaNeue" class=""><div class="" style="margin: 0cm;">References:</div><div class="" style="margin: 0cm;">[1] F. D. C. Farrell, O. Hallatschek, D. Marenduzzo, and B. Waclaw, Physical Review Letters 111, (2013). </div><div class="" style="margin: 0cm;">[2] M. A. A. Grant, B. Waclaw, R. J. Allen, and P. Cicuta, Journal of The Royal Society Interface 11, 20140400 (2014). </div><div class="" style="margin: 0cm;">[3] M. Gralka, F. Stiewe, F. Farrell, W. Möbius, B. Waclaw, and O. Hallatschek, Ecology Letters 19, 889 (2016). </div><div class="" style="margin: 0cm;">[4] F. D. Farrell, M. Gralka, O. Hallatschek, and B. Waclaw, Journal of The Royal Society Interface 14, 20170073 (2017).</div><div class="" style="margin: 0cm;">[5] C. Watson, P. Hush, J. Williams, A. Dawson, N. Ojkic, S. Titmuss, and B. Waclaw, EPL 123, 68001 (2018).</div></font></div><div class="" style="font-family: HelveticaNeue; margin: 0cm; background-color: white;"><br class=""></div></div><div class="" style="font-family: HelveticaNeue; margin: 0px; font-stretch: normal; line-height: normal;">We warmly welcome everyone to attend the talk and the Soft Matter Coffee Break after the seminar, held in room 2.63 (2nd floor).</div><div class="" style="font-family: HelveticaNeue;"><br class=""></div><div class="" style="font-family: HelveticaNeue;"><font face="HelveticaNeue" class=""><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class="">Maria Ekiel-Jeżewska</font></div><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class="">Maciej Lisicki</font></div><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class="">Piotr Szymczak</font></div><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><font face="HelveticaNeue" class="">Panagiotis Theodorakis </font></div><div class=""><font face="HelveticaNeue" class=""><br class=""></font></div></font></div><div class=""><div dir="auto" class="" style="font-family: HelveticaNeue; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div><br class=""><br class=""><div class="">
<meta charset="UTF-8" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="">--</div><div class="">dr hab. Maciej Lisicki</div><div class="">Institute of Theoretical Physics | Faculty of Physics</div><div class="">University of Warsaw</div><div class=""><a href="http://softmatter.fuw.edu.pl" class="">softmatter.fuw.edu.pl</a></div><div class=""><br class=""></div><div class=""><br class=""></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div><div class=""><br class=""></div></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">
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