<html><body><div style="font-family: times new roman, new york, times, serif; font-size: 12pt; color: #000000"><div><strong><span lang="EN-GB" style="font-size: 12.0pt; font-family: 'Arial','sans-serif';" data-mce-style="font-size: 12.0pt; font-family: 'Arial','sans-serif';">Poštovani,</span></strong><span lang="EN-GB" style="font-size: 12.0pt; font-family: 'Arial','sans-serif';" data-mce-style="font-size: 12.0pt; font-family: 'Arial','sans-serif';"><br> <strong>podsjećamo Vas na <span style="color: red;" data-mce-style="color: red;">današnji</span> seminar na</strong></span><span lang="EN-GB" style="font-size: 10.0pt; font-family: 'Arial','sans-serif';" data-mce-style="font-size: 10.0pt; font-family: 'Arial','sans-serif';"> </span><strong><span lang="EN-GB" style="font-size: 12.0pt; font-family: 'Arial','sans-serif';" data-mce-style="font-size: 12.0pt; font-family: 'Arial','sans-serif';">Institutu za fiziku u <span style="color: red;" data-mce-style="color: red;">15:00 </span>sati:</span></strong></div><div><strong> </strong></div><div style="text-align: center;"><strong><img src="cid:009fae3f1655c964800e9d9f8f63014906005dc9@zimbra" data-mce-src="cid:009fae3f1655c964800e9d9f8f63014906005dc9@zimbra"><br></strong></div><div style="text-align: center;"><strong><br></strong></div><div style="text-align: center;" data-mce-style="text-align: center;"><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><span lang="EN-GB" style="font-family: 'Century Gothic','sans-serif'; color: #5f5f5f;" data-mce-style="font-family: 'Century Gothic','sans-serif'; color: #5f5f5f;">Institut za fiziku, Bijenička cesta 46,</span></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><span lang="EN-GB" style="font-family: 'Century Gothic','sans-serif'; color: #5f5f5f;" data-mce-style="font-family: 'Century Gothic','sans-serif'; color: #5f5f5f;">predavaonica u zgradi Mladen Paić</span></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><span lang="EN-GB" style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif'; color: #993300;" data-mce-style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif'; color: #993300;">utorak, 26. kolovoza 2014., u 15:00 sati</span></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><span lang="EN-GB" style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif'; color: #993300;" data-mce-style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif'; color: #993300;"><br></span></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><br></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><b><span style="font-size: 16.0pt; font-family: 'Times New Roman','serif'; color: #55913c;" data-mce-style="font-size: 16.0pt; font-family: 'Times New Roman','serif'; color: #55913c;">Physical limits of the accuracy of cell chemotaxis</span></b></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><br></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><br></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><span lang="EN-GB" style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif';">Dr. </span><span lang="EN-GB" style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif';">sc. Igor Šegota</span><span lang="EN-GB" style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 14.0pt; font-family: 'Century Gothic','sans-serif';"></span></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><br></b></p><p align="center" style="text-align: center; margin: 0px;" data-mce-style="text-align: center; margin: 0px;"><b><span style="font-size: 11pt; font-family: 'Century Gothic', sans-serif;" data-mce-style="font-size: 11pt; font-family: 'Century Gothic', sans-serif;">Department of Physics, Cornell University</span></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><b><i><span lang="EN-GB" style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';">E-mail: <span style="color: blue;" data-mce-style="color: blue;"><a href="mailto:igs0001@gmail.com" data-mce-href="mailto:igs0001@gmail.com">igs0001@gmail.com</a></span></span></i></b><br></b></p><p align="center" style="margin: 0px; text-align: center;" data-mce-style="margin: 0px; text-align: center;"><b><br></b></p><p align="center" style="margin: 0px; text-align: left;" data-mce-style="margin: 0px; text-align: left;"><b><b><span style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';">A fundamental problem in the study of living matter is how and with what precision single cells measure and orient themselves along extracellular chemical gradients. Eukaryotic cells can accurately sense very shallow gradients where the difference in cell receptor occupancy between the front and the back of the cell is only few molecules. This implies that their sensing performance approaches limits set by basic physical principles. In particular, the stochastic processes of binding and unbinding of these molecules to cell receptors have recently been suggested as the main limiting factor. However, despite the advances in chemical identification of the involved molecules, it is still an open question how parameters such as the total receptor number per cell and the affinity of binding sites for these molecules affect the limits of gradient sensing. I will show how a combination of quantitative experiments and statistical mechanics demonstrates that cells surprisingly acquire much more information about the gradient than allowed by contemporary models of their physical limits. In addition, I will also theoretically show that cells can amplify chemical gradients by secreting proteins that degrade these signaling molecules and that the secretion rate of these proteins matches its rough experimental estimate.</span></b></b></p><p align="center" style="margin: 0px; text-align: left;" data-mce-style="margin: 0px; text-align: left;"><b><b><span style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';"><br></span></b></b></p><p align="center" style="margin: 0px; text-align: left;" data-mce-style="margin: 0px; text-align: left;"><b><b><span style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';"></span></b></b></p><p style="margin: 0px; text-align: left;"><b><span lang="EN-GB" style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';">Voditelji seminara IF-a: Nikša Krstulović i Osor Bari</span></b><b><span lang="HR" style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';">šić</span></b><b><span lang="HR" style="font-size: 10.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 10.0pt; font-family: 'Century Gothic','sans-serif';"></span></b></p><p align="center" style="margin: 0px; text-align: left;" data-mce-style="margin: 0px; text-align: left;"><b><b><span style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';" data-mce-style="font-size: 11.0pt; font-family: 'Century Gothic','sans-serif';"><br></span></b></b></p><p align="center" style="margin: 0px; text-align: left;" data-mce-style="margin: 0px; text-align: left;"><br></p><p align="center" style="margin: 0px; text-align: left;" data-mce-style="margin: 0px; text-align: left;"><br></p></div></div></body></html>