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January 01, 2013

  • Date:12SundayJanuary 2025

    The Clore Center for Biological Physics

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    Time
    12:45 - 14:30
    Title
    Rethinking Cryo-EM, by Cryo-STEM
    Location
    Nella and Leon Benoziyo Physics Library
    LecturerProf. Michael Elbaum and Dr Shahar Seifer
    lunch will be served at 12:45
    Organizer
    Clore Center for Biological Physics
    Contact
    AbstractShow full text abstract about Cryo-EM has famously revolutionized structural biology with ...»
    Cryo-EM has famously revolutionized structural biology with atomic-scale resolution of macromolecules in 3D. The conventional protocol is based on wide-field imaging with phase contrast introduced by defocus, followed by extensive image processing and averaging from a great number of identical objects. Key assumptions break down in the extension toward 3D imaging of thicker specimens such as cells, however, and especially for interpretation of unique features.The talk will be in two parts (by Michael and Shahar). The first will introduce an alternative imaging modality by scanning a focused probe, i.e., scanning transmission electron microscopy, or STEM, which circumvents some of these constraints. New camera technologies enable recording of the entire pattern of diffraction at every pixel, called 4D STEM. Combining the imaging with tomography, we explore new methods to exploit the wave coherence for 3D reconstruction with optimal contrast and resolution. Examples include crystals of heme, intact cells and sections of cell multilayers, and bacteriophage for the latest advances. The second part will center on the physical mechanisms of electron scattering relevant to cryo-EM. Combined with an energy loss spectrometer, a 4D STEM measurement provides atomic differential cross-sections, both elastic and inelastic. The elastic part relates to de Broglie phase delay by the average electric potential. The inelastic part is mainly due to generation of plasmons and scattering by the resulting polarization. The cross-sections provide data to test new modeling approaches, as well as to develop characterization tools for biological and other organic materials.FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.biosoftweizmann.com/
    Lecture
  • Date:13MondayJanuary 2025

    Foundations of Computer Science Seminar

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    Time
    11:15 - 12:15
    Title
    Aligning Machine Learning with Society
    Location
    Jacob Ziskind Building
    Room 1 - 1 חדר
    LecturerLee Cohen
    Stanford
    Organizer
    Department of Computer Science and Applied Mathematics
    Contact
    AbstractShow full text abstract about Machine Learning (ML) systems are increasingly integrated in...»
    Machine Learning (ML) systems are increasingly integrated into society, but challenges arise when human incentives and expectations are overlooked. In this talk, I will present frameworks for aligning ML with society, focusing on strategic classification and personalization in decision making.
    Strategic classification models scenarios where individuals, aware of the deployed classifier, manipulate their observable attributes to achieve favorable outcomes. For example, individuals might apply for additional credit cards to boost their credit score just so they can qualify for a loan, even though it doesn’t impact their ability to repay the loan. The learning goal is to find a classifier robust against strategic manipulations. I will answer a fundamental question: Does learnability imply strategic learnability?

    In addition, I will discuss multi-objective Markov Decision Processes (MDPs), which involve multiple, potentially conflicting objectives. In classic reinforcement learning and MDPs, policies are evaluated with scalar reward functions, implying that every optimal policy is optimal for all users. However, real-world scenarios involve multiple, sometimes conflicting objectives, necessitating personalized solutions. I will present an MDP framework that accommodates different user preferences over objectives, where preferences are learned via policy comparisons, and the goal is to efficiently compute a near-optimal policy for a given user.
    Lecture
  • Date:13MondayJanuary 2025

    Midrasha on Groups Seminar

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    Time
    11:15 - 13:00
    Title
    Cost, L²-Betti numbers, and free groups: distinguishing free groups with von-Neumann algebras
    Location
    Elaine and Bram Goldsmith Building for Mathematics and Computer Sciences
    Room 208 - חדר 208
    LecturerMichael Glasner
    Weizmann
    Organizer
    Department of Mathematics
    Contact
    AbstractShow full text abstract about This is the first of two talks on cost, L²-Betti numbers, an...»
    This is the first of two talks on cost, L²-Betti numbers, and free groups. In this talk, I will show that two free ergodic p.m.p. actions of the free groups F_n and F_m are not orbit equivalent. This will be achieved by utilizing the concept of the cost of the orbit equivalence relation and related von-Neumann algebras. The content will primarily be based on Sections 4 and 5 of Ioana’s paper. For more details and the exact reference, click here.
    Lecture
  • Date:13MondayJanuary 2025

    Midrasha on Groups Seminar

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    Time
    14:15 - 16:00
    Title
    Probabilistic laws on groups
    Location
    Jacob Ziskind Building
    Room 1 - 1 חדר
    LecturerGuy Blachar
    Weizmann
    Organizer
    Department of Mathematics
    Contact
    AbstractShow full text abstract about Suppose a finite group satisfies the following property: If ...»
    Suppose a finite group satisfies the following property: If you take two random elements, then with probability bigger than 5/8 they commute. Then this group is commutative. Starting from this well-known result, it is natural to ask: Do similar results hold for other laws (p-groups, nilpotent groups...)? Are there analogous results for infinite groups? Are there phenomena specific to the infinite setup? We will survey known and new results in this area. New results are joint with Gideon Amir, Maria Gerasimova and Gady Kozma.
    Lecture
  • Date:14TuesdayJanuary 2025

    Designing fully computational and efficient de novo enzymes: insights into catalysis and foldability

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    Time
    14:00 - 15:00
    Location
    Gerhard M.J. Schmidt Lecture Hall
    LecturerDina Listov
    Organizer
    Department of Chemical and Structural Biology
    Lecture
  • Date:15WednesdayJanuary 2025

    Machine Learning and Statistics Seminar

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    Time
    11:15 - 12:15
    Title
    Algebraic Approaches and Deep Neural Models for 3D Scene Reconstruction and Camera Pose Estimation in Static and Dynamic Environments
    Location
    Jacob Ziskind Building
    Room 1 - 1 חדר
    LecturerYoni Kasten
    Nvidia Research
    Organizer
    Department of Computer Science and Applied Mathematics
    Contact
    AbstractShow full text abstract about This talk will explore advances in 3D scene reconstruction, ...»
    This talk will explore advances in 3D scene reconstruction, focusing on approaches to estimate camera poses and scene structures in challenging multiview and dynamic content scenarios. First, I will outline foundational aspects of my earlier work, where we characterized the algebraic structure of fundamental and essential matrices in multiview settings and developed deep learning methods for joint recovery of camera parameters and sparse 3D scene structures. The main part of the talk introduces TracksTo4D (NeurIPS 2024), a novel, efficient method for reconstructing dynamic 3D structures and camera motion from casual videos. TracksTo4D leverages a dedicated encoder, trained in an unsupervised way on a dataset of casual videos, that uses 2D point tracks as input to infer dynamic 3D structures and camera motion. Our architecture takes into account symmetries in the problem, enforces the reconstruction to be of low rank, and models both static and dynamic scene components. Our model demonstrates strong generalization to unseen videos from new categories, achieving accurate 3D reconstruction and camera localization through a single feed-forward pass while drastically reducing running times.

    Bio:

    Yoni Kasten is a senior research scientist at NVIDIA Research in Tel Aviv, on Prof. Gal Chechik’s team. His research in 3D computer vision focuses on algebraic characterizations of multi-camera systems and deep neural models for surface reconstruction, dynamic scene modeling, and 4D scene reconstruction. Yoni earned his PhD from the Weizmann Institute, where his work on structure from motion estimation using algebraic characterizations, supervised by Prof. Ronen Basri, received the John F. Kennedy Prize for Outstanding Doctoral Research. He also completed his M.Sc. in Computer Science at the Hebrew University of Jerusalem under the supervision of Prof. Shmuel Peleg and Prof. Michael Werman.
    Lecture
  • Date:15WednesdayJanuary 2025

    “Evolution of nervous systems - a view from nematodes"

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    Time
    13:00 - 14:00
    Location
    Gerhard M.J. Schmidt Lecture Hall
    LecturerProf.Oliver Hobert
    Columbia University
    Contact
    Lecture
  • Date:15WednesdayJanuary 2025

    Chemical and Biological Physics Dept. -Guest Seminar

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    Time
    13:00 - 14:00
    Location
    perlman
    404
    LecturerDr. Natalie Fardian-Melamed, Columbia University, NY, USA
    AbstractShow full text abstract about Mechanical force is a critical feature for most physical pro...»
    Mechanical force is a critical feature for most physical processes, and remote measure of mechanical signals with high force sensitivity and spatial resolution is crucial for progress in fields as diverse as robotics, biophysics, civil engineering, and medicine. Existing nanoscale remote force sensors, however, are very limited in the dynamic range of forces they can detect, and are rarely compatible with subsurface operation, restricting sensor applicability [1]. In this talk, I will describe how we leverage the extreme optical nonlinearity offered by photon-avalanche [2], and its susceptibility to steep change due to minute changes in the environment – to create nanoscale force sensors that can be addressed remotely by continuous-wave, deeply-penetrating, infrared light, and can detect picoNewton to microNewton forces with a dynamic range spanning more than four orders of magnitude [3]. Using atomic force microscopy coupled with single-nanoparticle optical spectroscopy, we characterize the mechano-optics of different Tm3+-doped avalanching upconverting nanoparticles on a single particle level, to rationally design force sensors with different modalities of force-dependent optical readout, including mechanobrightening and mechanochromism. By manipulating the interionic distances and hence energy transfer pathways within the nanosensors by application of force, we demonstrate exceptional mechanical sensitivity coupled with high single-particle brightness, over multiple scales of force. The adaptability of these nanoscale optical force sensors, along with their multiscale sensing capability, enable operation in the dynamic and versatile environments present in diverse, real-world structures spanning biological organisms to nanoelectromechanical systems.
    Lecture
  • Date:16ThursdayJanuary 2025

    Vision and AI

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    Time
    12:15 - 13:15
    Title
    Interpreting the Inner Workings of Vision Models
    Location
    Jacob Ziskind Building
    Room 1 - 1 חדר
    LecturerYossi Gandelsman
    UC Berkeley/Meta
    Organizer
    Department of Computer Science and Applied Mathematics
    Contact
    AbstractShow full text abstract about In this talk, I present an approach for interpreting the int...»
    In this talk, I present an approach for interpreting the internal computation in deep vision models. I show that these interpretations can be used to detect model bugs and to improve the performance of pre-trained deep neural networks (e.g., reducing hallucinations from image captioners and detecting and removing spurious correlations in CLIP) without any additional training. Moreover, the obtained understanding of deep representations can unlock new model capabilities (e.g., novel identity editing techniques in diffusion models and faithful image inversion in GANs). I demonstrate how to find common representations across different models (discriminative and generative) and how deep representations can be adapted at test-time to improve model generalization without any additional supervision. Finally, I discuss future work on improving the presented interpretation techniques and their application to continual model correction and scientific discovery.

    Bio: Yossi is a EECS PhD at UC Berkeley, advised by Alexei Efros, and a visiting researcher at Meta. Before that, he was a member of the perception team at Google Research (now Google-DeepMind). He completed his M.Sc. at Weizmann Institute, advised by Prof. Michal Irani. His research centers around deep learning, computer vision, and mechanistic interpretability.
    Lecture
  • Date:16ThursdayJanuary 2025

    Geometric Functional Analysis and Probability Seminar

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    Time
    13:30 - 14:30
    Title
    Free boundary problems and particle systems
    Location
    Jacob Ziskind Building
    Room 155 - חדר 155
    LecturerRami Atar
    Technion
    Organizer
    Department of Mathematics
    Contact
    AbstractShow full text abstract about Particle systems that can be described macroscopically via f...»
    Particle systems that can be described macroscopically via free boundary problems (FBP) include the $N$-branching Brownian motion (branching Brownian particles on the line with removal of the leftmost particle upon each branching), and the Atlas model (Brownian particles on the line where the leftmost particle is equipped with a positive drift). The regularity of the free boundary plays a crucial role in proving the particle system -- FBP relation, but does not hold in some natural generalizations of these models. I will describe a weak FBP formulation where control over free boundary regularity is not required in order to achieve this relation in the two cases above. I will also describe an analogous weak formulation of a ``free obstacle’' problem aimed at a branching Brownian motion with removals occurring at the most densely populated areas.

    This is partly based on joint works with Amarjit Budhiraja and with Leonid Mytnik and Gershon Wolansky.
    Lecture
  • Date:16ThursdayJanuary 2025

    Harnessing Cancer Paradigms for the Treatment of Heart Failure and Fibrosis

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    Time
    14:00 - 15:00
    Location
    Max and Lillian Candiotty Building
    LecturerProf. Ami Aronheim
    Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine, Technion.
    Organizer
    Moross Integrated Cancer Center (MICC)
    Contact
    Lecture
  • Date:16ThursdayJanuary 2025

    The ESCRT machinery: an evolutionary conserved, a multi-purpose membrane remodeling deviceounced

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    Time
    15:00 - 16:00
    Location
    Nella and Leon Benoziyo Building for Biological Sciences
    Auditorium room 191c
    LecturerProf. Natalie Elia
    The Department of Life Sciences, Ben-Gurion University
    Organizer
    Department of Biomolecular Sciences
    Contact
    AbstractShow full text abstract about The ESCRT membrane remodeling complex, found across all life...»
    The ESCRT membrane remodeling complex, found across all life forms, exhibits a versatility that transcends evolutionary boundaries. From orchestrating the constriction of micron-wide tubes in cell division to facilitating the budding of 50 nm vesicles in receptor degradation, ESCRTs perform diverse functions in animal cells. In recent years, ESCRT homologs were identified in prokaryotes, highlighting a role for this protein machinery in the ancient world.  We seek to understand the mechanistic principles underlying the functional diversity of the ESCRT system across evolution. Specifically, we focus on understanding how the ESCRT complex orchestrate in cells to constrict and cut membranes in eukaryotes, focusing on its role in cell division, and in prokaryotes, focusing on the recently discovered Asgard archaea. By combining high-resolution imaging with biochemical and structural studies we aim to unlock the secrets of this fundamental membrane remodeling machinery and its potential role in evolution.
    Lecture
  • Date:19SundayJanuary 2025

    Allochthonous groundwater microorganisms affect coastal seawater microbial abundance, activity and diversity

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    Time
    11:00 - 12:00
    Location
    Sussman Family Building for Environmental Sciences
    M. Magaritz seminar room
    LecturerKeren Yanuka-Golub
    AbstractShow full text abstract about Submarine groundwater discharge (SGD) is a globally importan...»
    Submarine groundwater discharge (SGD) is a globally important processsupplying nutrients and trace elements to the coastal environment, thusplaying a pivotal role in sustaining marine primary productivity. Along withnutrients, groundwater also contains allochthonous microbes that aredischarged from the terrestrial subsurface into the sea. Currently, little isknown about the interactions between groundwater-borne and coastalseawater microbial populations, and groundwater microbes' role uponintroduction to coastal seawater populations. In the current study weinvestigated seawater microbial abundance, activity and diversity in a sitestrongly influenced by SGD. In addition, through laboratory-controlledbottle incubations, we mimicked different mixing scenarios betweengroundwater and seawater. Our results demonstrate that the addition of0.1 μm filtered groundwater stimulated heterotrophic activity andincreased microbial abundance compared to control coastal seawater,whereas 0.22 μm filtration treatments induced primary productivity andSynechococcus growth. 16S rRNA gene sequencing showed a strongshift from a SAR11-rich community in the control samples toRhodobacteraceae dominance in the <0.1 μm treatment, in agreementwith Rhodobacteraceae enrichment in the SGD field site. These resultssuggest that microbes delivered by SGD may affect the abundance,activity and diversity of intrinsic microbes in coastal seawater, highlightingthe cryptic interplay between groundwater and seawater microbes incoastal environments, which has important implications for carboncycling.
    Lecture
  • Date:19SundayJanuary 2025

    The Clore Center for Biological Physics

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    Time
    12:45 - 14:30
    Title
    A social view of viral decision making
    Location
    Nella and Leon Benoziyo Physics Library
    LecturerProf. Avigdor Eldar
    lunch will be served at 12:45
    Organizer
    Clore Center for Biological Physics
    Contact
    AbstractShow full text abstract about Temperate bacterial viruses (or phages) have two divergent l...»
    Temperate bacterial viruses (or phages) have two divergent life cycles when infecting their host; A virulent (lytic) cycle where they rapidly replicate to produce hundreds of virions and kill their host, or a dormant (lysogenic) cycle where it typically integrates into the host genome and replicate with it. The social environment of the cell is a major determinant of the phage’s decision between its life cycles, but the consequences of sociality are still being explored. In this lecture, I will introduce the canonical phage lambda model where this has been studied and a recent model for phage sociality which is based on detection of small molecule signals. I will then discuss three works which combine experiments, genomics and theory to discuss the nature of social signals in different systems and their implication for phage decision making, social cooperation and their evolution. FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.biosoftweizmann.com/ 
    Lecture
  • Date:20MondayJanuary 2025

    Neuromodulation of experience-dependent sexually dimorphic learning

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    Time
    11:00 - 12:15
    Location
    WSOS (FGS)
    A
    LecturerSonu Kurien Dr. Meital Oren Lab
    Student Seminar-PhD Thesis Defense-HybridZoom:  https://weizmann.zoom.us/j/7576151783?pwd=V2hoQUxvN1IzVlRCU3ZESmcwMHA2Zz09Meeting ID: 757 615 1783Password: 050925
    Organizer
    Department of Brain Sciences
    AbstractShow full text abstract about How do sex-specific evolutionary drives influence decision-m...»
    How do sex-specific evolutionary drives influence decision-making processes when facing a shared environmental cue? Given the sex biases in disease states, some of which include a significant cognitive component, it is crucial to evaluate the influence of genetic sex on brain mechanisms from the ground up. In my thesis, I investigate if and how the genetic sex affects context and experience-dependent behavioral plasticity when learning an environmental cue. By utilizing a genes-to-behavior approach, I unravel sexual dimorphism in an ethologically relevant behavioral paradigm. C. elegans males do not learn to avoid the pathogenic bacteria PA14 as efficiently and rapidly as hermaphrodites, even though the pathogenicity is perceived. I explore the neuronal representations following training that encode this dimorphism and observe a possible sensory gating mechanism. The transcriptomic and subsequent behavioral analysis revealed the influence of the neuromodulatory network on male behavior. In particular, npr-5, an ortholog of the mammalian NPY receptor, regulates male learning by modulating typical neuronal activity. Finally, we uncover that male decision-making behavior is shaped by sexual status and is regulated by npr-5. Taken together, the work portrays how shared experiences drive sex-specific plasticity in hermaphrodites and males by modulating learning to fulfill perceived evolutionary needs. 
    Lecture
  • Date:20MondayJanuary 2025

    Midrasha on Groups Seminar

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    Time
    11:15 - 13:00
    Title
    Confined subgroups and irreducible lattices
    Location
    Elaine and Bram Goldsmith Building for Mathematics and Computer Sciences
    Room 208 - חדר 208
    LecturerArie Levit
    TAU
    Organizer
    Department of Mathematics
    Contact
    AbstractShow full text abstract about A subgroup H < G is called confined if there is a compact...»
    A subgroup H < G is called confined if there is a compact subset K of G such that every conjugate of H intersects K at some point other than identity. We prove that every confined subgroup of an irreducible lattice in a higher rank semisimple Lie group has finite index. Since a non-trivial normal subgroup is confined, our result extends the Margulis normal subgroup theorem. We do not rely on Kazhdan’s property (T), and instead obtain a spectral gap from the product structure. More generally, we show that any confined discrete subgroup of a higher rank semisimple Lie group satisfying a certain irreducibility condition is a lattice. This extends the recent work of Fraczyk and Gelander, removing the property (T) assumption. Joint work with Uri Bader and Tsachik Gelander.
    Lecture
  • Date:20MondayJanuary 2025

    Midrasha on Groups Seminar

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    Time
    14:15 - 16:00
    Title
    Cost, L²-Betti numbers, and free groups: bounding the rank gradient
    Location
    Jacob Ziskind Building
    Room 1 - 1 חדר
    LecturerTomer Konforty
    TAU
    Organizer
    Department of Mathematics
    Contact
    AbstractShow full text abstract about This is the second of two talks on cost, L²-Betti numbers, a...»
    This is the second of two talks on cost, L²-Betti numbers, and free groups. In this talk, I will define the rank gradient of a group and explain its relationship to cost. I will mostly follow this paper of Abért–Nikolov and Section 5.5 in the book of Kammeyer.
    Lecture
  • Date:21TuesdayJanuary 2025

    The Evolution and Plasticity of the CONNECTOME

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    Time
    12:30 - 13:30
    Location
    Gerhard M.J. Schmidt Lecture Hall
    LecturerProf. Yaniv Assaf
    Organizer
    Department of Brain Sciences
    Contact
    AbstractShow full text abstract about At every aspect of our lives, function determines structure....»
    At every aspect of our lives, function determines structure. Just as new roads are built between developing cities, network wires are laid to accommodate faster communication demands, and social networks form around shared goals, the brain also remodels its connectome to adapt to the continuous and dynamic changes in functional demands.The&nbsp;connectome&nbsp;refers to the functional and structural characteristics of brain connectivity, spanning from the micron level (neural circuits) to the macroscopic level (long-scale pathways). This intricate network, encompassing the white matter and beyond, facilitates the transmission of information across different brain regions. When the integrity of the&nbsp;connectome&nbsp;is compromised, brain function deteriorates. Thus, the&nbsp;connectome&nbsp;is fundamental to everything the brain does.Traditionally, without the tools to explore the&nbsp;connectome&nbsp;in vivo, it was assumed to be stable and fixed. Much of white matter research focused on mapping the geographical structure of the network and its connected areas. However, advances in magnetic resonance imaging (MRI), particularly diffusion MRI, have opened a new window into the in vivo physiology of the white matter and the&nbsp;connectome.By measuring the microstructural properties of white matter, researchers now have the opportunity to investigate its physiology and dynamics. This presentation will demonstrate how the&nbsp;connectome&nbsp;can be measured, outline its macro- and microstructural features, and describe its evolutionary characteristics by comparing the&nbsp;connectomes&nbsp;of 100 different mammalian species. Additionally, we will explore the role of the&nbsp;connectome&nbsp;in brain plasticity and its remarkable dynamics.Light refreshments before the seminar
    Lecture
  • Date:22WednesdayJanuary 2025

    "Though the city used to be called Luz" –SIRT6, aging and beyond.

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    Time
    11:00 - 12:00
    Title
    The mammalian longevity associated acetylome
    Location
    Arthur and Rochelle Belfer Building for Biomedical Research
    LecturerDr. Haim Cohen
    Organizer
    Sagol Institute for Longevity Research
    Contact
    AbstractShow full text abstract about Despite extensive studies at the genomic, transcriptomic, an...»
    Despite extensive studies at the genomic, transcriptomic, and metabolomic levels, the underlying mechanisms regulating longevity remain incompletely understood. Post-translational protein acetylation has been suggested to regulate aspects of longevity. To further explore the role of acetylation, we developed the PHARAOH computational tool, based on the 100-fold differences in longevity within the mammalian class. Analyzing acetylome and proteome data across 107 mammalian species identified multiple significant longevity-associated acetylated lysine residues in mice and humans, controlling many longevity-related pathways. Specifically, we found that longevity-associated acetylation sites help resolve the Peto Paradox: the enigma of why animals with increased body size live longer yet do not exhibit much higher cancer incidence. Our findings show a significant positive correlation between these new acetylation sites and protection against multiple types of cancer in humans. Moreover, mutating these sites reduced the anti-neoplastic functions of the acetylated proteins. These findings provide new insights into the pivotal role of protein acetylation in mammalian longevity, suggesting potential interventions to extend human healthspan.
    Lecture
  • Date:22WednesdayJanuary 2025

    Deciphering the role of the DCC/UNC-40 receptor in dopaminergic neurons during health and disease

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    Time
    11:00 - 13:00
    Location
    Koshland Room, Belfer building
    Meeting ID: 757 615 1783 Password: 050925
    LecturerSapir Sela
    student PhD defense seminar
    Organizer
    Department of Brain Sciences
    Contact
    AbstractShow full text abstract about TheUNC-40 receptor, a homolog of the human DCC receptor, is ...»
    TheUNC-40 receptor, a homolog of the human DCC receptor, is critical for neuronal development and maintenance, with its dysregulation implicated in neurodegenerative diseases such as Parkinson’s disease. This study investigates the role of UNC-40 in dopaminergic neuron health and degeneration using Caenorhabditis elegans as a model system. Loss-of-function mutations in UNC-40 conferred resistance to 6-hydroxydopamine (6-OHDA)-induced DA neuron degeneration, while stabilization of UNC-40 via mutation in the CPD regulatory site led to spontaneous, selective DA neurodegeneration independent of toxins. Mechanistic analyses revealed that UNC-40 stabilization triggers parthanatos, a caspase-independent cell death pathway driven by mitochondrial oxidative stress. Pharmacological inhibition of PARP-1 and treatment with mitochondrial antioxidants significantly rescued DA neurons from degeneration.suggesting UNC-40 stabilization causes mitochondrial oxidative stress. Remarkably, UNC-40-induced degeneration was sexually dimorphic, affecting hermaphrodites but not males. Transcriptomic analyses revealed significant gene expression changes in hermaphrodites carrying stabilized UNC40, while males exhibited minimal changes, suggesting intrinsic protective mechanisms. UNC-6, a ligand for UNC-40, was identified as a critical external factor modulating this dimorphism; its absence in hermaphrodites rendered them vulnerable, while its presence in males made them unaffected by the stabilization of the receptor. Behavioral assays revealed functional impairments in hermaphrodites with stabilized UNC-40, linked to altered synaptic activity and excitotoxicity. These findings establish UNC-40 as a key regulator of DA neuron health, highlight its role in oxidative stress and synaptic maintenance, and underscore sexually dimorphic vulnerability to neurodegeneration. The parallels between UNC-40 in C. elegans and DCC in humans suggest conserved mechanisms underlying neurodegeneration and point to potential therapeutic targets for diseases like PD.
    Lecture

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