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פברואר 21, 2016
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Date:21שלישיינואר 2020הרצאה
פרופ' רון מילוא - מי שוקל יותר? סקר האוכלוסין הגדול של הטבע
More information שעה 12:00 - 12:00כותרת מי שוקל יותר? סקר האוכלוסין הגדול של הטבעמיקום אולם ע"ש דולפי ולולה אבנרמרצה Prof. Ron Milo מארגן המחלקה לתקשורת ודוברותדף בית צרו קשר -
Date:21שלישיינואר 2020הרצאה
Visualizing activity dependent signaling dynamics in intact neuronal circuits
More information שעה 12:30 - 12:30מיקום אולם הרצאות ע"ש גרהרד שמידטמרצה Dr. Tal Laviv
Max Planck Florida Institute for Neuroscienceמארגן המחלקה למדעי המוחצרו קשר תקציר Show full text abstract about Sensory experience can change the structure and function o...»
Sensory experience can change the structure and function of neurons in the brain over a wide range of timescales, from milliseconds-second modulation of synaptic activity to long-lasting alterations of genetic programs, lasting minutes to hours. While conversion of synaptic activity into long-lasting nuclear signaling is vital for learning and neuronal development, we still lack a clear understanding of its basic operating principles. To address this, I will describe recent advancements using two-photon fluorescence lifetime imaging and new biosensors which allowed us to image the activity of CREB, an activity-dependent transcription factor important for synaptic plasticity, at single cell resolution in awake mice. Simultaneous imaging of CREB and Ca2+ in the visual cortex permitted us to explore how sensory deprivation (dark-rearing) can modulate the sensitivity and duration of CREB activity to sensory-evoked Ca2+ elevations. Future work using this approach will allow us to unravel synapse to nucleus signaling dynamics underlying experience-dependent plasticity in the brain.
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Date:21שלישיינואר 2020הרצאה
Visualizing activity dependent signaling dynamics in intact neuronal circuits
More information שעה 12:30 - 13:30מיקום אולם הרצאות ע"ש גרהרד שמידטמרצה Dr. Tal Laviv - Joint Seminar - Dept. of Neurobiology & Biomolecular Sciences
Max Planck Florida Institute for Neuroscienceמארגן המחלקה למדעים ביומולקולרייםצרו קשר תקציר Show full text abstract about Sensory experience can change the structure and function of ...» Sensory experience can change the structure and function of neurons in the brain over a wide range of timescales, from milliseconds-second modulation of synaptic activity to long-lasting alterations of genetic programs, lasting minutes to hours. While conversion of synaptic activity into long-lasting nuclear signaling is vital for learning and neuronal development, we still lack a clear understanding of its basic operating principles. To address this, I will describe recent advancements using two-photon fluorescence lifetime imaging and new biosensors which allowed us to image the activity of CREB, an activity-dependent transcription factor important for synaptic plasticity, at single cell resolution in awake mice. Simultaneous imaging of CREB and Ca2+ in the visual cortex permitted us to explore how sensory deprivation (dark-rearing) can modulate the sensitivity and duration of CREB activity to sensory-evoked Ca2+ elevations. Future work using this approach will allow us to unravel synapse to nucleus signaling dynamics underlying experience-dependent plasticity in the brain. -
Date:21שלישיינואר 2020הרצאה
Connecting the Dots: Multiple-substrate orchestration in bacterial type IV secretion systems
More information שעה 14:00 - 15:00מיקום בניין הלן ומילטון קימלמןמרצה Dr. Amit Meir
Yale Universityמארגן המחלקה לביולוגיה מבנית וכימיתצרו קשר -
Date:22רביעיינואר 2020הרצאה
IMM Guest seminar- Dr. Ela Elyada, will lecture on "Uncovering fibroblast heterogeneity in pancreatic cancer".
More information שעה 11:00 - 12:00מיקום בניין וולפסון למחקר ביולוגימארגן המחלקה לאימונולוגיה מערכתיתצרו קשר -
Date:22רביעיינואר 2020הרצאה
Chemical and Biological Physics Guest Seminar
More information שעה 11:00 - 11:00כותרת Phase transitions in membranes and gels, and their potential function in living cellsמיקום בניין פרלמן למדעי הכימיהמרצה Dr Matan Mussel, Amiram Debesh
NIH, USAמארגן המחלקה לפיזיקה כימית וביולוגיתצרו קשר תקציר Show full text abstract about Soft matter systems offer a useful framework to study minima...» Soft matter systems offer a useful framework to study minimal models for living cells, helping to explain and quantify various aspects of biological functions in terms of macroscopic variables, symmetries, and universal properties. In this talk I will describe two such materials with particular focus on phenomena that arise when the system is near a phase transition. In the first part, I will describe a theoretical model of sound in lipid membranes near phase transition that corresponds to observations of nonlinear sound pulses in lipid monolayers as well as action potentials in living cells. Key properties are sigmoidal response to stimulation amplitude, and annihilation upon collision. I will explain the role of the phase diagram in producing the nonlinear properties and how sound in lipid membranes propagates thermal, electrical, and chemical variations in addition to the well-known mechanical changes. In the second part of the talk, I will describe a volume phase transition induced by the exchange of mono- and divalent cations in a polyelectrolyte hydrogel model. Ion-exchange and volume phase transition play a key role in several physiological functions where biopolymers are exposed to both mono- and multivalent counterions. These functions include, for instance, the packaging of DNA, andthe storage and release of cell secretory products. Our observations suggest that although the state diagram of the model system depends on many parameters of the gel and surrounding fluid, the volume phase transition exhibits universal properties. Osmotic swelling pressure measurements further reveal that both the second and third virial coefficients decrease with increasing divalent cation concentration until the volume transition is reached. -
Date:23חמישיינואר 2020סימפוזיונים
Growing Droplets in Cells and Gels
More information שעה 11:15 - 12:30מיקום בניין הפיזיקה ע"ש עדנה וק.ב. וייסמןמרצה Eric Dufresne
ETHמארגן הפקולטה לפיזיקהצרו קשר תקציר Show full text abstract about To function effectively, living cells compartmentalize myria...» To function effectively, living cells compartmentalize myriad chemical reactions. In the classic view, distinct functional volumes are separated by thin oily-barriers called membranes. Recently, the spontaneous sorting of cellular components into membraneless liquid-like domains has been appreciated as an alternate route to compartmentalization.
I will review the essential physical concepts thought to underly these biological phenomena, and outline some fundamental questions in soft matter physics that they inspire. Then, I will focus on the coupling of phase separation to elastic stresses in polymer networks. Using a series of experiments spanning living cells and synthetic materials, I will demonstrate that bulk mechanical stresses dramatically impact every stage in the life of a droplet, from nucleation and growth to ripening and dissolution.
These physical phenomena suggest new mechanisms that cells could exploit to regulate phase separation, and open new routes to the assembly of functional materials
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Date:23חמישיינואר 2020הרצאה
Identification of similarities in archaeological collections using deep learning algorithms: a Levantine case study
More information שעה 11:30 - 12:30מיקום בניין לביוכימיה על שם נלה וליאון בנוזיומרצה Avi Resler
Electrical Engineering, Tel Aviv Universityצרו קשר תקציר Show full text abstract about Artefacts that are found in archaeological excavations are o...» Artefacts that are found in archaeological excavations are often recognized by experts, who compare their appearance to other labeled objects that they have seen before or present in archaeological catalogs. Since this procedure may be subjective, scientific methods that aid archaeologists have become increasingly popular.
We have developed two machine learning tools which capture the similarity between two artefacts or similarities between groups of artefacts based on their RGB images. For the first antique recognition tool, we used face recognition deep neural network architecture, to measure the "archaeological" distance between images. In the second community detection tool, we aggregate similarities between images and measure the distance between assemblages - i.e., group of images. Based on that we applied a network-theory community detection algorithm, to find groups of archaeological sites that are linked to each other.
To test our methods, we used a highly diverse dataset of Israeli antiques. This dataset is a good case study due to geographical proximity between archaeological sites and the presence of artefacts from a wide range of archaeological ages. -
Date:23חמישיינואר 2020הרצאה
Regulating the regulators:
More information שעה 13:00 - 14:00כותרת Regulation of NK cell intracellular inhibitory immune checkpoint to govern anti-tumor immunityמיקום בניין ע"ש מקס ולילאן קנדיוטימרצה Prof. Mira Barda-Saad
Bar Ilan Universityמארגן המחלקה לאימונולוגיה ורגנרציה ביולוגיתצרו קשר -
Date:23חמישיינואר 2020הרצאה
Pelletron meeting - by invitation only
More information שעה 16:00 - 17:30צרו קשר -
Date:26ראשוןינואר 2020הרצאה
Quantifying Holocene rainfall and evaporation in East Asia
More information שעה 11:00 - 11:00מיקום בניין משפחת זוסמןמרצה Yoni Goldsmith
Hebrew University of Jerusalemמארגן המחלקה למדעי כדור הארץ וכוכבי הלכתצרו קשר -
Date:26ראשוןינואר 2020הרצאה
Mechanical interaction between cells in fibrous environments
More information שעה 11:00 - 12:00מיקום בניין פרלמן למדעי הכימיהמרצה Dr. Ayelet Lesman
School of Mechanical Engineering, Faculty of Engineering, Tel-Aviv Universityמארגן המחלקה לכימיה מולקולרית ולמדע חומריםצרו קשר תקציר Show full text abstract about Tissues are made up of cells and an extracellular matrix (EC...» Tissues are made up of cells and an extracellular matrix (ECM), a cross-linked network of fibers that exhibits complex mechanics. Cells actively alter the ECM structure and mechanics by applying contractile forces. These forces can propagate far into the matrix and allow for remote cellular sensing. We study experimentally and computationally how cell-generated forces are transmitted in fibrous environments, the associated physical mechanisms, and the ability of the propagated forces to support mechanical interaction between distant cells. Also, we demonstrate how the dynamic changes in the ECM structure can lead to improve transport of molecules traveling between the cells, facilitating mechano-biochemical interactions. Such long-range force interactions through the ECM can drive large-scale cooperative biological processes, such that occur during wound healing and morphogenesis. Our work can also provide design parameters for biomaterials used in tissue engineering applications. -
Date:26ראשוןינואר 2020הרצאה
Chemical and Biological Physics Guest Seminar
More information שעה 14:00 - 15:00כותרת Non-Genetic “Optogenetics”: Silicon Based Bio-Interfaces for Multi-scale Optical Modulationמיקום בניין פרלמן למדעי הכימיהמרצה Dr Menahem (Hemi) Rotenberg, Amiram Debesh
The James Franck Institute, the University of Chicagoמארגן המחלקה לפיזיקה כימית וביולוגיתצרו קשר תקציר Show full text abstract about Bioelectronics for cellular interrogation requires a minimal...» Bioelectronics for cellular interrogation requires a minimally invasive introduction of an electrical probe to the cell. Despite tremendous developments in the field of electroceuticals in the past decades, the available technologies are still associated with major limitations. Micropipette electrodes, micro- and nanoelectrode arrays, and nano-field effect transistors allow intracellular access with extremely high spatial resolution. However, these technologies are substrate-bound, do not allow reconfigurable recording or stimulation, and lack deep tissue access, which limits their use to in vitro application. Optogenetics can offer numerous mechanistic insights into cellular processes, but its spatial resolution is limited, especially for 3D tissues. Moreover, it requires genetic modification, which limits its potential therapeutic applications. In this talk, I will present my recent studies of developing new approaches for bio-interfaces using silicon micro- and nanostructures for non-genetic optical modulation, spanning from sub cellular interrogation with extremely high spatial resolutions to whole organ optical modulation. For sub-cellular interrogation, we used tailored made photovoltaic silicon nanowires with p-i-n core-shell design. These nanowires were hybridized with living myofibroblasts and used as free sanding cell-silicon hybrids with leadless optical modulation capabilities. We used focused laser to perform intracellular electrical interrogation with high, sub-cellular spatial resolution. Thereafter, we used these hybrids to tackle a long-standing debate regarding electrical coupling between myofibroblasts and cardiomyocytes in vivo, by interrogating specific myofibroblasts within the 3D volume of the cardiac tissue. We also show this technology’s utility for neuronal investigation by hybridizing myelinating oligodendrocytes and interfacing them with neurons, allowing the investigation of calcium transients’ role in the myelination process with unprecedented spatial control. For whole organ interface we used flexible single crystalline silicon membranes, that were able to adhere and wrap around the heart and sciatic nerve. We used optical stimulation to perform heart pacing at different location on the heart, and sciatic nerve excitation. These results demonstrate potential biomedical applications for cardiac resynchronization therapy and sciatic nerve neuro-regenerative treatments. -
Date:27שניינואר 2020כנסים
Israeli Fly meeting 2020
More information שעה 08:00 - 08:00מיקום מרכז כנסים על-שם דויד לופאטייושב ראש Oren Schuldiner -
Date:27שניינואר 2020סימפוזיונים
Annual Pearlman lecture - Catalysts Live & Up Close: Hunting for the Hidden Chemistry in Catalysis
More information שעה 11:00 - 12:15מיקום אולם הרצאות ע"ש גרהרד שמידטמרצה Prof. Bert M. Weckhuysen
University of Utrechtמארגן הפקולטה לכימיהצרו קשר -
Date:27שניינואר 2020הרצאה
Braginsky Center for the Interface between the Sciences and the Humanities
More information שעה 11:00 - 11:00כותרת Evolutions: Science as Storytellingמיקום אולם ע"ש דולפי ולולה אבנרמרצה Prof. Oren Harman
Science, Technology and Society, Bar Ilan UNiversityמארגן מרכז על-שם ברגינסקי לשילוב בין מדעי הטבע למדעי הרוחצרו קשר -
Date:27שניינואר 2020הרצאה
Singlet oxygen as an essential component in plant stress response
More information שעה 14:00 - 14:00כותרת PhD Thesis Defense - Room 690C - Floor 6מיקום בניין לביוכימיה על שם נלה וליאון בנוזיומרצה Tomer Chen
Prof. Robert Fluhr's Lab., Dept. of Plant and Environmental Sciences, WISמארגן המחלקה למדעי הצמח והסביבהצרו קשר -
Date:27שניינואר 2020הרצאה
Inferring the dynamics of learning from sensory decision-making behavior
More information שעה 14:00 - 14:00מיקום אולם הרצאות ע"ש גרהרד שמידטמרצה Prof. Jonathan Pillow
Dept of Psychology, Princeton Universityמארגן המחלקה למדעי המוחצרו קשר תקציר Show full text abstract about The dynamics of learning in natural and artificial environme...» The dynamics of learning in natural and artificial environments is a problem of great interest to both neuroscientists and artificial intelligence experts. However, standard analyses of animal training data either treat behavior as fixed, or track only coarse performance statistics (e.g., accuracy and bias), providing limited insight into the dynamic evolution of behavioral strategies over the course of learning. To overcome these limitations, we propose a dynamic psychophysical model that efficiently tracks trial-to-trial changes in behavior over the course of training. In this talk, I will describe recent work based on a dynamic logistic regression model that captures the time-varying dependencies of behavior on stimuli and other task covariates. We applied our method to psychophysical data from both human subjects and rats learning a sensory discrimination task. We successfully tracked the dynamics of psychophysical weights during training, capturing day-to-day and trial-to-trial fluctuations in behavioral strategy. We leverage the model's flexibility model to investigate why rats frequently make mistakes on easy trials, demonstrating that so-called "lapses" often arise from sub-optimal weighting of task covariates. Finally, I will describe recent work on adaptive optimal training, which combines ideas from reinforcement learning and adaptive experimental design to formulate methods for inferring animal learning rules from behavior, and using these rules to speed up animal training. -
Date:27שניינואר 2020הרצאה
The Surprises of a Nanochannel –
More information שעה 14:15 - 14:15מיקום בניין הפיזיקה ע"ש עדנה וק.ב. וייסמןמרצה Yoav Green
BGUמארגן המחלקה לפיזיקה של מערכות מורכבותצרו קשר תקציר Show full text abstract about Nanofluidic systems have the potential to revolutionize nume...» Nanofluidic systems have the potential to revolutionize numerous fields of high practical importance, including desalination, energy harvesting, bio-sensing, fluid based electrical circuits, and more. It is, therefore, not surprising that in the last two decades we are witnessing an increase in nanofluidic-based research. However, realizing the full potential of nanofluidics remains conditional to conquering several significant challenges. Notably, our current understanding of the fundamental physical phenomena that govern ion transport through nanochannels is incomplete and many key questions remain open.
Fifteen years ago it was suggested that low-voltage Ohmic response of nanochannel-microchannels systems was dominated by the electrical resistance of the nanochannel, and that the resistances of the adjacent microchannels, were negligible. I will present evidence contradicting this suggestion that has since become paradigm. I will present a new modified paradigm which emphasizes the importance of the microchannels in determining the overall response. Our result suggest the need to conduct fundamental driven research to further reveal the physics of ion-transport at low-voltages so that we can unveil the physics at high-voltages where non-linear electroconvective effects are prevalent.
Bio: Yoav Green is currently a senior lecturer in the Department of Mechanical Engineering at Ben-Gurion University. Before that, Yoav was post-doctoral researcher in the Harvard T. H. Chan School of Public Health where he worked in the field of biomechanics. Yoav holds a PhD in mechanical engineering from the Technion - Israel Institute of Technology where his research fields were nanofluidics and electrokinetics. Yoav also holds an MSc in physics (astrophysics and astronomy) from the Weizmann Institute of Science, and BSc in aerospace engineering from the Technion. -
Date:28שלישיינואר 2020הרצאה
Chemical and Biological Physics Dept Seminar
More information שעה 11:00 - 11:00כותרת Wide-Field Single Photon-Counting Imaging for Fast and Highly Sensitive In Vivo Cell Trackingמיקום בניין פרלמן למדעי הכימיהמרצה Dr Rinat Ankri, Amiram Debesh
Postdoctoral Fellow, UCLA, CAמארגן המחלקה לפיזיקה כימית וביולוגיתצרו קשר תקציר Show full text abstract about Biomolecular imaging at the preclinical stage is an essentia...» Biomolecular imaging at the preclinical stage is an essential tool in various biomedical research areas such as immunology, oncology or neurology. Among all modalities available to date, optical imaging techniques play a central role, while fluorescence, in particular in the NIR region of the spectrum, provides high sensitivity and high specificity with relatively cheap instrumentation. Several whole-body optical pre-clinical NIR imaging systems are commercially available. Instruments using continuous wave (CW or time-independent) illumination allow basic small animal imaging at low cost. However, CW techniques cannot provide fluorescence lifetime contrast, which allows to probe the microenvironment and affords an increased multiplexing power. In the first part of my talk I will introduce our single photon, time-gated, phasor-based fluorescence lifetime Imaging method which circumvents limitations of conventional techniques in speed, specificity and ease of use, using fluorescent lifetime as the main contrast mechanism.
In the second part of my talk I will present the tracking and multiplexing of two different cell populations, based on their different lifetimes (following their fluorescent dyes-loading). Despite major advantages of optical based NIR imaging, the reason that NIR imagers are not clinically used, is that only very few such fluorescent molecules absorb and emit in the NIR (or in the shortwave infrared, SWIR region), and even fewer have favorable biological properties (and FDA approval). I will introduce small lung cancer and dendritic cells tracking using small polyethylene glycol/phosphatidylethanolamine (PEG–PE) micelles loaded with NIR dyes (using commercial dyes as well as dyes synthesized in Prof. Sletten’s lab, UCLA Chemistry Dept.). Micelles’ endocytosis into cells affords efficient loading and exhibits strong bio stability, enabling to track the loaded cells for several days using these formulations, even though dyes were diluted by cells division (leading to reduced dye concentration within the dividing cells). Moreover, fluorescent lifetime contrast (achieved through our time-gated imaging method), significantly improved these cells detection.
These advances in NIR fluorescence based imaging open up new avenues toward NIR and SWIR imaging for biomedical applications, such as tracking and monitoring cells during immunotherapy and/or drug delivery (treatment monitoring) for various types of disease.