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April 29, 2015

  • Date:28MondayDecember 2015

    Population networks : the promised land of wet computing

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    Time
    13:15 - 13:15
    Location
    Edna and K.B. Weissman Building of Physical Sciences
    LecturerDr. Renaud Renault
    Institut Curie and Institut Pierre-Gilles de Gennes (IPGG)
    Organizer
    Clore Center for Biological Physics
    Contact
    AbstractShow 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.
    Lecture
  • Date:28MondayDecember 2015

    Emergent thermal dynamics in Darwinian evolution

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    Time
    14:15 - 14:15
    Location
    Edna and K.B. Weissman Building of Physical Sciences
    LecturerGuy Bunin
    MIT
    Organizer
    Department of Physics of Complex Systems
    Contact
    AbstractShow 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.


    Lecture
  • Date:29TuesdayDecember 2015

    How interactions and environments modulate strategies of microbial growth

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    Time
    10:00 - 10:00
    Location
    Arthur and Rochelle Belfer Building for Biomedical Research
    Organizer
    Department of Systems Immunology
    Contact
    Lecture
  • Date:29TuesdayDecember 2015

    3D SUPERSYMMETRIC VECTOR MODELS, ACCIDENTAL SYMMETRIES, AND THE CONFORMAL BOOTSTRAP

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    Time
    10:30 - 12:00
    Location
    Neve Shalom
    LecturerRan Yacoby
    Princeton
    Organizer
    Department of Particle Physics and Astrophysics
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    AbstractShow 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
    Lecture
  • Date:29TuesdayDecember 2015

    Challenges and Solutions to Functional Nanoparticle Devices

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    Time
    11:00 - 12:00
    Location
    Gerhard M.J. Schmidt Lecture Hall
    LecturerProf. Richard Robinson
    Cornell University, NY
    Organizer
    Department of Molecular Chemistry and Materials Science
    Contact
    Lecture
  • Date:29TuesdayDecember 2015

    UNIVERSAL PROPERTIES OF CYLINDER PARTITION FUNCTIONS

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    Time
    12:00 - 12:00
    Location
    Neve Shalom
    LecturerLorenzo Di Pietro
    Weizmann Institute of Science
    Organizer
    Department of Particle Physics and Astrophysics
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    AbstractShow 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.
    Lecture
  • Date:29TuesdayDecember 2015

    Systemic spread of antiviral RNAi immunity in insects through extracellular vesicles

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    Time
    12:15 - 12:15
    Location
    Arthur and Rochelle Belfer Building for Biomedical Research
    LecturerProf. Carla Saleh
    Institut Pasteur, Virology Department
    Organizer
    Department of Molecular Genetics
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    Lecture
  • Date:29TuesdayDecember 2015

    Understanding the roles of amygdala-prefrontal connections through targeted optogenetic perturbation

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    Time
    12:30 - 12:30
    Location
    Gerhard M.J. Schmidt Lecture Hall
    LecturerProf. Ofer Yizhar
    Department of Neurobiology, WIS
    Organizer
    Department of Brain Sciences
    Contact
    AbstractShow 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.
    Lecture
  • Date:29TuesdayDecember 2015

    Masha & the bear - Russian children's theatre

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    Time
    18:00 - 20:00
    Location
    Michael Sela Auditorium
    Contact
    Cultural Events
  • Date:30WednesdayDecember 2015

    Oxytocin and the ontogeny of social behaviour

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    Time
    10:00 - 10:00
    Location
    Arthur and Rochelle Belfer Building for Biomedical Research
    LecturerProf. Gil Levkowitz
    Dept. of Molecular Cell Biology, WIS
    Contact
    Lecture
  • Date:30WednesdayDecember 2015

    How to resolve the proton radius puzzle?

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    Time
    11:00 - 12:30
    Location
    Technion, Lidow 502
    LecturerGil Paz
    Wayne State University
    Organizer
    Department of Particle Physics and Astrophysics
    Contact
    Lecture
  • Date:30WednesdayDecember 2015

    Exotic Scenarios for Diphoton Excess

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    Time
    13:30 - 13:30
    Location
    Technion, Lidow 502
    LecturerRyosuke Sato
    Weizmann Institute
    Organizer
    Department of Particle Physics and Astrophysics
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    Lecture
  • Date:30WednesdayDecember 2015

    Chemical Physics Department Guest Seminar

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    Time
    14:30 - 14:30
    Title
    Relaxometry and dephasing imaging of superparamagnetic magnetite nanoparticles at ambient conditions
    Location
    Perlman Chemical Sciences Building
    LecturerDr. Amit Finkler
    University of Stuttgart
    Organizer
    Department of Chemical and Biological Physics
    Contact
    AbstractShow 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.
    Lecture
  • Date:30WednesdayDecember 2015

    Molecular Neuroscience Forum Seminar

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    Time
    15:00 - 16:00
    Title
    Negative regulation of oligodendrocyte differentiation and myelination
    Location
    Wolfson Building for Biological Research
    LecturerHyunjeong Yang
    WIS
    Organizer
    Department of Biomolecular Sciences
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    Lecture
  • Date:31ThursdayDecember 2015

    A synthetic, single-cell approach to mammalian signaling, memory, and cell fate transition circuits

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    Time
    10:00 - 10:00
    Location
    Arthur and Rochelle Belfer Building for Biomedical Research
    LecturerProf. Michael Elowitz
    California Institute of Technology, Pasadena, USA
    Organizer
    Department of Molecular Genetics
    Contact
    Lecture
  • Date:31ThursdayDecember 2015

    Perplexing dynamics of unentangled polymers

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    Time
    11:15 - 12:30
    Location
    Edna and K.B. Weissman Building of Physical Sciences
    LecturerGuy Bunin
    MIT
    Organizer
    Faculty of Physics
    Contact
    AbstractShow 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.
    Colloquia
  • Date:31ThursdayDecember 2015

    Microglia development follows a stepwise program to support the developing brain

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    Time
    14:00 - 14:30
    Title
    THE OFER LIDER RESEARCH-IN-PROGRESS SEMINAR 2015
    Location
    Wolfson Building for Biological Research
    LecturerDr. Deborah Winter
    Organizer
    Department of Systems Immunology
    Contact
    Lecture
  • Date:31ThursdayDecember 2015

    Immunometabolism and obesity: the money is in the ATM

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    Time
    14:30 - 15:00
    Title
    THE OFER LIDER RESEARCH-IN-PROGRESS SEMINAR 2015
    Location
    Wolfson Building for Biological Research
    LecturerDr. Hagit Shapiro
    Organizer
    Department of Systems Immunology
    Contact
    Lecture
  • Date:31ThursdayDecember 2015

    Strong tW scattering at the LHC

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    Time
    16:00 - 16:00
    Location
    Edna and K.B. Weissman Building of Physical Sciences
    LecturerJeff Asaf Dror
    Cornell
    Organizer
    Department of Particle Physics and Astrophysics
    Contact
    AbstractShow 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."
    Lecture
  • Date:01FridayJanuary 2016

    Nostalgic show

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    Time
    19:00 - 19:00
    Location
    Michael Sela Auditorium
    Contact
    Cultural Events

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