BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:We are all different: Modeling key individual differences in physi ological systems DTSTART;VALUE=DATE-TIME:20260324T130500Z DTEND;VALUE=DATE-TIME:20260324T140500Z DTSTAMP;VALUE=DATE-TIME:20260426T060657Z UID:indico-contribution-805-10334@events.saip.org.za DESCRIPTION:Speakers: Anita LAYTON (University of Waterloo)\nMathematical models of whole-body dynamics have advanced our understanding of human int egrative systems that regulate physiological processes such as metabolism\ , temperature\, and blood pressure. For most of these whole-body models\, baseline parameters describe a 35-year-old young adult man who weighs 70 k g. As such\, even among adults those models may not accurately represent h alf of the population (women)\, the older population\, and those who weigh significantly more than 70 kg. Indeed\, sex\, age\, and weight are known modulators of physiological function. To more accurately simulate a person who does not look like that "baseline person\," or to explain the mechani sms that yield the observed sex or age differences\, these factors should be incorporated into mathematical models of physiological systems. Another key modulator is the time of day\, because most physiological processes a re regulated by the circadian clocks. Thus\, ideally\, mathematical models of integrative physiological systems should be specific to either a man o r woman\, of a certain age and weight\, and a given time of day. A major g oal of our research program is to build models specific to different subpo pulations\, and conduct model simulations to unravel the functional impact s of individual differences.\n\nhttps://events.saip.org.za/event/272/contr ibutions/10334/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10334/ END:VEVENT BEGIN:VEVENT SUMMARY:Opening Plenary Remarks DTSTART;VALUE=DATE-TIME:20260324T130000Z DTEND;VALUE=DATE-TIME:20260324T130500Z DTSTAMP;VALUE=DATE-TIME:20260426T060657Z UID:indico-contribution-805-10348@events.saip.org.za DESCRIPTION:https://events.saip.org.za/event/272/contributions/10348/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10348/ END:VEVENT BEGIN:VEVENT SUMMARY:From Sample to Structure: An Introduction to Cryo Electron Microsc opy and Single Particle Analysis DTSTART;VALUE=DATE-TIME:20260327T120000Z DTEND;VALUE=DATE-TIME:20260327T123000Z DTSTAMP;VALUE=DATE-TIME:20260426T060657Z UID:indico-contribution-805-10329@events.saip.org.za DESCRIPTION:Speakers: Rebecca Thompson (Thermo Fisher Scientific)\nUnderst anding biological function at the molecular level requires direct visualiz ation of macromolecular structure. For decades\, structural biology has re lied on approaches such as X ray crystallography and nuclear magnetic reso nance spectroscopy. Over the past decade\, cryo electron microscopy has ra pidly matured into a central method for protein structure determination\, expanding the scope of questions that can be addressed at high resolution. In 2025\, over 10\,000 structures were deposited into the electron micros copy data bank\, and in the next few years it is projected single particle cryoEM will become the predominant technique for protein structure determ ination. \nCryo electron microscopy enables structure determination of pro teins and macromolecular complexes in a near native\, vitrified state with out the need for crystallization. In particular\, single particle analysis has become a powerful and widely adopted method for high resolution struc ture determination of soluble proteins\, membrane proteins\, viral particl es\, and dynamic multicomponent assemblies. Advances in direct electron de tectors\, electron optics\, automation\, and computational image processin g now make near atomic resolution structure determination increasingly rou tine in many academic laboratories.\nThe impact of cryo EM extends across diverse areas of the life sciences. In virology and infectious disease res earch\, cryo EM has resolved the structures of viral surface proteins\, in tact virions\, and host pathogen complexes\, directly informing vaccine de sign and antiviral development. In therapeutic research\, from small molec ules to biologics and monoclonal antibodies\, cryo EM enables detailed vis ualization of ligand binding\, antigen antibody interactions\, and epitope mapping\, accelerating structure guided drug design. In plant biotechnolo gy and crop science\, structural insights into photosynthetic complexes\, stress response machinery\, and plant pathogen interactions are guiding st rategies to improve yield\, resilience\, and food security.\nAt the same t ime\, advances in in silico protein structure prediction\, including AI ba sed approaches such as AlphaFold\, have transformed computational modellin g. While these tools are powerful\, experimental structural biology remain s essential. Cryo EM provides direct structural validation\, captures conf ormational heterogeneity\, reveals ligand binding and complex formation\, and enables the study of assemblies and cellular environments that remain difficult to access computationally.\nThis presentation will introduce the fundamental principles of cryo EM and single particle analysis\, placing the method within the broader structural biology workflow. Key steps\, inc luding sample preparation\, vitrification\, data acquisition\, and image r econstruction\, will be outlined with emphasis on practical considerations . Examples from modern 200 kV cryo TEM platforms such as the Glacios micro scope will illustrate how recent technological developments support a wide range of research projects. \nThe talk will conclude by looking beyond is olated particles toward cryo electron tomography and in situ structural an alysis. These approaches enable visualization of molecular machines direct ly within cells\, bridging molecular and cellular scales and opening new o pportunities to study biology in its native context.\n\nhttps://events.sai p.org.za/event/272/contributions/10329/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10329/ END:VEVENT BEGIN:VEVENT SUMMARY:Multiscale local self-organization of the human metaphase mitotic spindle DTSTART;VALUE=DATE-TIME:20260327T130000Z DTEND;VALUE=DATE-TIME:20260327T133000Z DTSTAMP;VALUE=DATE-TIME:20260426T060657Z UID:indico-contribution-805-10335@events.saip.org.za DESCRIPTION:Speakers: Will Conway (New York Structural Biology Consortium) \nThe current model of mitotic spindle assembly proposes that microtubules nucleate at spindle poles and grow inward to capture chromosomes. However \, recent structural studies reveal that spindles are composed of short mi crotubules that do not span the full pole-to-chromosome distance. It remai ns unclear how short\, disconnected microtubules collectively generate and transmit the forces necessary to build a bipolar spindle. Using cryo-elec tron tomography to map microtubule polarity in intact human cells\, we fin d that spindle microtubules form locally antiparallel dense regions with a consistent 8 nm wall-to-wall spacing. This spacing is too narrow for most molecular motors to fit between adjacent microtubules\, ruling out direct motor crosslinking of the bundle interior. Instead\, spacing scales inver sely with local microtubule density\, consistent with density-driven steri c interactions\, analogous to liquid crystal ordering. Motor perturbations combined with centriole depletion\, which generated motor-active monopola r spindles\, further revealed that the kinesin-5 Eg5 motor establishes loc al antiparallel overlap independently of spindle bipolarity\, while a bala nce of Eg5 and dynein regulates microtubule density to maintain spindle ar chitecture. Together\, these findings challenge the pole-centric model and suggest a bottom-up\, self-organized model in which motor-microtubule int eractions within dense bundles generate forces that build bipolar spindles .\n\nhttps://events.saip.org.za/event/272/contributions/10335/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10335/ END:VEVENT BEGIN:VEVENT SUMMARY:The importance of water in biology - an example of receptor functi on and implications for optogenetics DTSTART;VALUE=DATE-TIME:20260326T120000Z DTEND;VALUE=DATE-TIME:20260326T124000Z DTSTAMP;VALUE=DATE-TIME:20260426T060657Z UID:indico-contribution-805-10331@events.saip.org.za DESCRIPTION:Speakers: Anthony Watts (University of Oxford)\nWater\, in its many states\, has a pivotal role in biology. But resolving it at the mole cular level has been a challenge. Here\, we resolve and describe how water determines the way in which an external stimulus\, light in this example\ , intimately controls how the stimulus is conformational changes in membra ne receptors in response to a stimulus\, and capturing their functionally relevant dynamics\, is very challenging. Over the years we have addressed this challenge using a range of spectroscopic approaches [1\,2\,3] on func tionally competent photoreceptors\, often in their natural membranes [4] o r Lipodisqs™ [5\,6]. More recently\, we have complemented this work with functional studies\, mass spec characterization [7] and very high resolut ion (1.07 Å) crystallography [8\,9\,10]\, as well as photo-induced x-ray\ , free electron laser studies (XFELS)\, without the use of detergents and including natural lipids. This high-resolution information reveals waters and their importance in both receptor activation-desensitization and QM(SC C-DFTB)/MM MD trajectories give information about the activation process. The system studied is achearhodopsin-3 (AR3)\, a photoreceptor utilized wi dely in optogenetics despite the lack of structures until now. We suggest that the different arrangement of internal water networks in AR3 is respon sible for the faster photocycle kinetics compared to homologs – AR3 is ~ 10x more efficient than bacteriorhodopsin at current generation. These ins ights may well have generic implications for other receptors.\n\n(1). Higm an et al.\, (2011) Angew. Chemie 50(36):8432\n(2). Dijkman et al.\, (2018) Nature Comms. 9:1710\n(3). Dijkman et al.\, (2020) Science Advances\, 6:3 3\n(4). Lavington & Watts (2020) Biophys. Rev. 12:1287\n(5). Juarez et al. \, (2019) Chem. Phys. Lipids 221:167\n(6). Sawczyc et al (2023) Eur. Bioph ys J. 52:39\n(7). Hoi et al.\, (2021) Nano Letters\, 21(7):2824\n(8). Axfo rd et al.\, (2022) Acta Cryst D78:52\n(9). Juarez et al (2021) Nature Comm s. 12:629\n(10). Birsh et al.\, (2023) J. Appl. Cryst. 56:1361\n\nhttps:// events.saip.org.za/event/272/contributions/10331/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10331/ END:VEVENT BEGIN:VEVENT SUMMARY:Fluorescence-Lifetime Super-Resolution Microscopy DTSTART;VALUE=DATE-TIME:20260326T090000Z DTEND;VALUE=DATE-TIME:20260326T094000Z DTSTAMP;VALUE=DATE-TIME:20260426T060657Z UID:indico-contribution-805-10330@events.saip.org.za DESCRIPTION:Speakers: Jörg Enderlein (University of Göttingen)\nRecent a dvancements in super-resolution microscopy have enabled unprecedented insi ghts into the spatial organization of cellular structures. In this talk\, I will present a series of methodological innovations that synergistically integrate fluorescence-lifetime single-molecule localization microscopy ( FL-SMLM) [1\,2]\, image scanning microscopy (ISM) [3\,4]\, and metal-/gr aphene-induced energy transfer (MIET/GIET) imaging [5–7]. These approac hes collectively offer isotropic three-dimensional resolution at the nanom eter scale\, multiplexed imaging capabilities\, and robustness against chr omatic aberrations.\n\nFirst\, I will discuss our work on MIET and GIET mi croscopy\, which exploit distance-dependent quenching phenomena near metal lic or graphene interfaces to determine the axial position of single emitt ers with sub-10 nm accuracy. The combination of MIET with dSTORM or DNA-PA INT provides truly isotropic 3D resolution\, extending the reach of locali zation microscopy into the axial dimension without interferometric complex ity.\n\nSecond\, I will highlight the development of fluorescence lifetime DNA-PAINT (FL-PAINT)\, a technique that enables multi-target super-resolu tion imaging through fluorescence lifetime multiplexing without fluid exch ange. By utilizing orthogonally designed imager strands conjugated to fluo rophores with distinct lifetimes\, we achieve simultaneous imaging of mult iple targets in the dense intracellular environment.\n\nLastly\, I will in troduce our latest development of fluorescence-lifetime image scanning mic roscopy SMLM (FL-iSMLM)\, which achieves a near twofold enhancement in lat eral resolution by integrating a single-photon detector array into a confo cal laser scanning microscope. This method combines the localization preci sion of ISM with the multiplexing power of fluorescence-lifetime detection \, enabling sub-5 nm resolution in fixed cells while simultaneously allowi ng discrimination of targets based solely on their fluorescence lifetimes. \n\nReferences\n[1] J. C. Thiele\, D. A. Helmerich\, N. Oleksiievets\, R. Tsukanov\, E. Butkevich\, M. Sauer\, O. Nevskyi\, and J. Enderlein\, Confo cal Fluorescence-Lifetime Single-Molecule Localization Microscopy\, ACS Na no 14\, 14190 (2020).\n[2] J. C. Thiele\, O. Nevskyi\, D. A. Helmerich\, M . Sauer\, and J. Enderlein\, Advanced Data Analysis for Fluorescence-Lifet ime Single-Molecule Localization Microscopy\, Front. Bioinform. 1\, 740281 (2021).\n[3] C. B. Müller and J. Enderlein\, Image Scanning Microscopy\, Phys. Rev. Lett. 104\, 198101 (2010).\n[4] N. Radmacher\, O. Nevskyi\, J. I. Gallea\, J. C. Thiele\, I. Gregor\, S. O. Rizzoli\, and J. Enderlein\, Doubling the resolution of fluorescence-lifetime single-molecule localiza tion microscopy with image scanning microscopy\, Nat. Photon. 18\, 1059 (2 024).\n[5] A. I. Chizhik\, J. Rother\, I. Gregor\, A. Janshoff\, and J. En derlein\, Metal-induced energy transfer for live cell nanoscopy\, Nature P hoton 8\, 124 (2014).\n[6] A. Ghosh\, A. Sharma\, A. I. Chizhik\, S. Isban er\, D. Ruhlandt\, R. Tsukanov\, I. Gregor\, N. Karedla\, and J. Enderlein \, Graphene-based metal-induced energy transfer for sub-nanometre optical localization\, Nat. Photonics 13\, 860 (2019).\n[7] J. C. Thiele\, M. Jung blut\, D. A. Helmerich\, R. Tsukanov\, A. Chizhik\, A. I. Chizhik\, M. Sch nermann\, M. Sauer\, O. Nevskyi\, and J. Enderlein\, Isotropic Three-Dimen sional Dual-Color Super-Resolution Microscopy with Metal-Induced Energy Tr ansfer\, Science Advances 8\, 14190 (2021).\n\nhttps://events.saip.org.za/ event/272/contributions/10330/ LOCATION: URL:https://events.saip.org.za/event/272/contributions/10330/ END:VEVENT END:VCALENDAR