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April 29, 2015
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Date:28MondayDecember 2015Lecture
Population networks : the promised land of wet computing
More information Time 13:15 - 13:15Location Edna and K.B. Weissman Building of Physical SciencesLecturer Dr. Renaud Renault
Institut Curie and Institut Pierre-Gilles de Gennes (IPGG)Organizer Clore Center for Biological PhysicsContact Abstract Show full text abstract about Neurons grown in vitro are in theory amenable to generate an...» Neurons grown in vitro are in theory amenable to generate and process information as they normally do inside brains, enabling many ground-breaking applications including glucose-powered neural implants to repair cerebral functions, in vitro models for cognitive studies, and even new kinds of artificial intelligence. However, there is currently no consensus about how to harness the capabilities of neurons in culture or how to build robust and efficient neuronal devices.
Based on the properties of cultured networks that are both resilient and experimentally accessible on the one hand, and the theoretical framework of Frank Rosenblatt’s perceptron on the other hand, we propose a new architecture for neuronal devices that can bypass many limitations of previous realizations. Our devices are divided into several neuronal populations by the mean of compartmented microchips, individually acting as cohesive « switch-like » units. Between the compartments, axon tunnels of various geometries have been developed to precisely control the directions and strengths of the connections between units, thus defining the initial computational abilities of our devices.
The capacity of perceptrons to learn new computations on the fly by adjusting the strength of the connections between their units can also be implemented in such neuronal devices by exploiting synaptic plasticity, the natural ability of living neurons to change the strength of their connections when subjected to specific stimulations. Communication and learning are currently being investigated inside such devices, through a fully optical interface based on optogenetics and calcium imaging that can furthermore be implemented with off-the-shelf components.
These recent theoretical and technological developments lay a solid foundation for the study of communication, computation, plasticity and learning inside living neuronal devices, and their implementation in living neuronal computers and their applications.
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Date:28MondayDecember 2015Lecture
Emergent thermal dynamics in Darwinian evolution
More information Time 14:15 - 14:15Location Edna and K.B. Weissman Building of Physical SciencesLecturer Guy Bunin
MITOrganizer Department of Physics of Complex SystemsContact Abstract Show full text abstract about In the past years, the dynamics of a finite population under...» In the past years, the dynamics of a finite population undergoing mutations and selection have been mapped to those of a single system in contact with a heat bath. Here we argue that such thermal dynamics will hold much more generally when growth rate increases slowly, as will eventually happen in systems with rugged fitness landscapes. Many non-trivial suggestions from the physics of glasses may be thus applied to evolutionary systems. We discuss two examples: experimental probes for rugged landscapes, and faster-than-Darwinian evolution.
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Date:29TuesdayDecember 2015Lecture
How interactions and environments modulate strategies of microbial growth
More information Time 10:00 - 10:00Location Arthur and Rochelle Belfer Building for Biomedical ResearchOrganizer Department of Systems ImmunologyContact -
Date:29TuesdayDecember 2015Lecture
3D SUPERSYMMETRIC VECTOR MODELS, ACCIDENTAL SYMMETRIES, AND THE CONFORMAL BOOTSTRAP
More information Time 10:30 - 12:00Location Neve ShalomLecturer Ran Yacoby
PrincetonOrganizer Department of Particle Physics and AstrophysicsHomepage Contact Abstract Show full text abstract about I will discuss a particular class of theories, which form a ...» I will discuss a particular class of theories, which form a certain supersymmetric generalization of three-dimensional O(N) vector models. By combining tools of the conformal bootstrap with results obtained through supersymmetric localization, I will argue that theories in this class exhibit a symmetry enhancement at the infrared fixed point. This example is interesting because the putative infrared theory with no symmetry enhancement does not exhibit any obvious inconsistencies at first sight. Once the correct infrared theories have been identified, I will present a detailed numerical bootstrap analysis showing features (or "kinks") at positions that very nearly coincide with our expectation for these models. Moreover, I will present general numerical bounds in dimensions 3 -
Date:29TuesdayDecember 2015Lecture
Challenges and Solutions to Functional Nanoparticle Devices
More information Time 11:00 - 12:00Location Gerhard M.J. Schmidt Lecture HallLecturer Prof. Richard Robinson
Cornell University, NYOrganizer Department of Molecular Chemistry and Materials ScienceContact -
Date:29TuesdayDecember 2015Lecture
UNIVERSAL PROPERTIES OF CYLINDER PARTITION FUNCTIONS
More information Time 12:00 - 12:00Location Neve ShalomLecturer Lorenzo Di Pietro
Weizmann Institute of ScienceOrganizer Department of Particle Physics and AstrophysicsHomepage Contact Abstract Show full text abstract about We consider 4d N=1 superconformal theories on a cylinder. Th...» We consider 4d N=1 superconformal theories on a cylinder. The partition function on this geometry computes the superconformal index, and can be obtained via the path integral with time direction compactified on a circle and periodic conditions for fermions. We will use an effective field theory approach to derive formulas for the asymptotics of such partition functions in the limit of very large circle and of very small circle. These limits are completely fixed in terms of coefficients of the Weyl anomaly (a,c). We will explain why supersymmetry is a necessary condition in 4d to establish these higher dimensional analogues of classic results in 2d CFTs. Finally we will discuss the extension to 6d and some applications. -
Date:29TuesdayDecember 2015Lecture
Systemic spread of antiviral RNAi immunity in insects through extracellular vesicles
More information Time 12:15 - 12:15Location Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Prof. Carla Saleh
Institut Pasteur, Virology DepartmentOrganizer Department of Molecular GeneticsContact -
Date:29TuesdayDecember 2015Lecture
Understanding the roles of amygdala-prefrontal connections through targeted optogenetic perturbation
More information Time 12:30 - 12:30Location Gerhard M.J. Schmidt Lecture HallLecturer Prof. Ofer Yizhar
Department of Neurobiology, WISOrganizer Department of Brain SciencesContact Abstract Show full text abstract about Fear-related disorders are thought to reflect strong and per...» Fear-related disorders are thought to reflect strong and persistent learned fear associations resulting from aberrant synaptic plasticity mechanisms. The basolateral amygdala (BLA) and the medial prefrontal cortex (mPFC) play a key role in the acquisition and extinction of fear memories. Strong reciprocal synaptic connections between these two regions are believed to play a role in the encoding of fear memories, but the contribution of these projection pathways to memory formation and maintenance remains elusive. We evaluated several optogenetic approaches for silencing presynaptic terminals. Surprisingly, we found that sustained activation of Arch, a light-gated proton pump that is commonly used for optogenetic silencing, paradoxically causes presynaptic calcium influx and neurotransmitter release. This increase in neurotransmission was mediated by presynaptic alkalization and calcium influx, and resulted in recruitment of local-circuit feed-forward inhibition, potentially confounding the interpretation of such experiments. We therefore established an optogenetic stimulation protocol that evokes long-term depression in BLA-mPFC synapses. Using this approach, we explored the role of the BLA-mPFC pathway in fear learning. We found that attenuation of synaptic strength in this pathway prior to fear conditioning leads to impaired learning. In mice that have already acquired the cued fear association, depotentiation of BLA-mPFC inputs prior to extinction training facilitated the extinction process. Our findings suggest a new role for the BLA-mPFC pathway not only in the in the acquisition but also the maintenance of learned associations and provide a framework for functional analysis of long-range projections. -
Date:29TuesdayDecember 2015Cultural Events
Masha & the bear - Russian children's theatre
More information Time 18:00 - 20:00Location Michael Sela AuditoriumContact -
Date:30WednesdayDecember 2015Lecture
Oxytocin and the ontogeny of social behaviour
More information Time 10:00 - 10:00Location Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Prof. Gil Levkowitz
Dept. of Molecular Cell Biology, WISContact -
Date:30WednesdayDecember 2015Lecture
How to resolve the proton radius puzzle?
More information Time 11:00 - 12:30Location Technion, Lidow 502Lecturer Gil Paz
Wayne State UniversityOrganizer Department of Particle Physics and AstrophysicsContact -
Date:30WednesdayDecember 2015Lecture
Exotic Scenarios for Diphoton Excess
More information Time 13:30 - 13:30Location Technion, Lidow 502Lecturer Ryosuke Sato
Weizmann InstituteOrganizer Department of Particle Physics and AstrophysicsHomepage Contact -
Date:30WednesdayDecember 2015Lecture
Chemical Physics Department Guest Seminar
More information Time 14:30 - 14:30Title Relaxometry and dephasing imaging of superparamagnetic magnetite nanoparticles at ambient conditionsLocation Perlman Chemical Sciences BuildingLecturer Dr. Amit Finkler
University of StuttgartOrganizer Department of Chemical and Biological PhysicsContact Abstract Show full text abstract about We present a novel technique to image superparamagnetic iron...» We present a novel technique to image superparamagnetic iron oxide nanoparticles via their fluctuating magnetic fields. The detection is based on the nitrogen-vacancy (NV) color center in diamond, which allows optically detected magnetic resonance (ODMR) measurements on its electron spin structure. In combination with an atomic-force-microscope, this atomic-sized color center maps ambient magnetic fields in a wide frequency range from DC up to several GHz [1], while retaining a high spatial resolution in the sub-nanometer range
[2]. We demonstrate imaging of single 10 nm sized magnetite nanoparticles using this spin noise detection technique. By fitting simulations (Ornstein-Uhlenbeck process) to the data, we are able to infer additional information on such a particle and its dynamics, like the attempt frequency and the anisotropy constant [3]. This is of high interest to the proposed application of magnetite nanoparticles as an alternative MRI contrast agent or to the field of particle-aided tumor hyperthermia.
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Date:30WednesdayDecember 2015Lecture
Molecular Neuroscience Forum Seminar
More information Time 15:00 - 16:00Title Negative regulation of oligodendrocyte differentiation and myelinationLocation Wolfson Building for Biological ResearchLecturer Hyunjeong Yang
WISOrganizer Department of Biomolecular SciencesHomepage Contact -
Date:31ThursdayDecember 2015Lecture
A synthetic, single-cell approach to mammalian signaling, memory, and cell fate transition circuits
More information Time 10:00 - 10:00Location Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Prof. Michael Elowitz
California Institute of Technology, Pasadena, USAOrganizer Department of Molecular GeneticsContact -
Date:31ThursdayDecember 2015Colloquia
Perplexing dynamics of unentangled polymers
More information Time 11:15 - 12:30Location Edna and K.B. Weissman Building of Physical SciencesLecturer Guy Bunin
MITOrganizer Faculty of PhysicsContact Abstract Show full text abstract about When a polymer is quickly compressed it reaches a crumpled s...» When a polymer is quickly compressed it reaches a crumpled state that has attracted much attention as a model for DNA organization in the nucleus, conjectured to have a fractal struc-ture that has so far remained elusive. We will describe the relations between topology of knots, slow relaxation and the fast crumpling of the polymer, and propose a model for the col-lapse as a process similar to water drops condensing on a surface. Our model reproduces fea-tures of this state quantitatively, suggesting that the slow approach to scaling is related to a large dispersion in the sizes of ‘water drops’. Time permitting, we will present a model of unentangled directed polymers, whose universal properties are found to differ significantly from predictions of the best available theories. This suggests new directions in treating non-local topological constraints in polymer systems, a major open theoretical challenge. -
Date:31ThursdayDecember 2015Lecture
Microglia development follows a stepwise program to support the developing brain
More information Time 14:00 - 14:30Title THE OFER LIDER RESEARCH-IN-PROGRESS SEMINAR 2015Location Wolfson Building for Biological ResearchLecturer Dr. Deborah Winter Organizer Department of Systems ImmunologyContact -
Date:31ThursdayDecember 2015Lecture
Immunometabolism and obesity: the money is in the ATM
More information Time 14:30 - 15:00Title THE OFER LIDER RESEARCH-IN-PROGRESS SEMINAR 2015Location Wolfson Building for Biological ResearchLecturer Dr. Hagit Shapiro Organizer Department of Systems ImmunologyContact -
Date:31ThursdayDecember 2015Lecture
Strong tW scattering at the LHC
More information Time 16:00 - 16:00Location Edna and K.B. Weissman Building of Physical SciencesLecturer Jeff Asaf Dror
CornellOrganizer Department of Particle Physics and AstrophysicsContact Abstract Show full text abstract about "Deviations of the top electroweak couplings from their...» "Deviations of the top electroweak couplings from their Standard Model values imply that certain scattering amplitudes of third generation fermions and longitudinally polarized vector bosons and/or Higgses grow with energy. In this talk I will demonstrate how to use the high energies accessible at the LHC to enhance the sensitivity to non-standard top-Z couplings, which are currently very weakly constrained. I demonstrate the effectiveness of the approach by performing a detailed analysis of tW -> tW scattering, which can be probed at the LHC via pp -> ttWj. I will also present other scattering processes in the same class that could provide further tests of the top sector." -
Date:01FridayJanuary 2016Cultural Events
Nostalgic show
More information Time 19:00 - 19:00Location Michael Sela AuditoriumContact
