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  • Date:04MondayFebruary 2019

    Chemical and Biological Physics Guest Seminar

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    Time
    12:00
    Title
    Physics of the Nuclear Pore Complex: from phase separation to viral ‎infections
    Location
    Perlman Chemical Sciences Building
    Room 404
    Lecturer
    Prof. Anton Zilman
    University of Toronto
    Organizer
    Department of Chemical and Biological Physics
    Contact
    AbstractShow full text abstract about Nuclear Pore Complex (NPC) is a biomolecular “nanomachine” t...»
    Nuclear Pore Complex (NPC) is a biomolecular “nanomachine” that controls nucleocytoplasmic transport in eukaryotic cells. The key component of the functional architecture of the NPC is the assembly of the polymer-like intrinsically disordered proteins that line its passageway and play a central role in the NPC transport mechanism. Due to paucity of experimental methods capable to directly probe the morphology and the dynamics of this assembly in intact NPCs, much of our knowledge about its properties derives from /in vitro/ experiments interpreted through theoretical and computational modeling.
    Remarkably, despite their molecular complexity, much of the behavior of these assemblies and their selective permeability with respect to cargo-carrying transport proteins can be understood based on minimal complexity models relying on the statistical physics of molecular assemblies on the nanoscale. I will present the recent insights into the architecture and the dynamics of the NPC arising from the theoretical analysis of the wide range of experimental results.
    Lecture
  • Date:04MondayFebruary 2019

    Foundations of Computer Science Seminar

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    Time
    14:30 - 16:00
    Title
    The Power of Distributed Verifiers in Interactive Proofs
    Location
    Jacob Ziskind Building
    Room 155
    Lecturer
    Eylon Yogev
    Technion
    Organizer
    Faculty of Mathematics and Computer Science
    Faculty of Mathematical Sciences Seminar, Department of Computer Science and Applied Mathematics
    Faculty of Mathematical Sciences Seminar, Department of Mathematics
    Faculty of Mathematical Sciences Seminar
    Contact
    DetailsShow full text description of We explore the power of interactive proofs with a distribute...»
    We explore the power of interactive proofs with a distributed verifier. In this setting, the verifier consists of n nodes and a graph G that defines their communication pattern. The prover is a single entity that communicates with all nodes by short messages. The goal is to verify that the graph G belongs to some language in a small number of rounds, and with small communication bound, i.e., the proof size.

    This interactive model was introduced by Kol, Oshman and Saxena (PODC 2018) as a generalization of non-interactive distributed proofs. They demonstrated the power of interaction in this setting by constructing protocols for problems as Graph Symmetry and Graph Non-Isomorphism -- both of which require proofs of (n^2)-bits without interaction.

    In this work, we provide a new general framework for distributed interactive proofs that allows one to translate standard interactive protocols (i.e., with a centralized verifier) to ones where the verifier is distributed with a proof size that depends on the computational complexity of the verification algorithm run by the centralized verifier. We show the following:

    * Every (centralized) computation performed in time O(n) on a RAM can be translated into three-round distributed interactive protocol with O(log n) proof size. This implies that many graph problems for sparse graphs have succinct proofs (e.g., testing planarity).

    * Every (centralized) computation implemented by either a small space or by uniform NC circuit can be translated into a distributed protocol with O(1) rounds and O(log n) bits proof size for the low space case and polylog(n) many rounds and proof size for NC.

    * We show that for Graph Non-Isomorphism, one of the striking demonstrations of the power of interaction, there is a 4-round protocol with O(log n) proof size, improving upon the O(n*log n) proof size of Kol et al.

    * For many problems, we show how to reduce proof size below the seemingly natural barrier of log n. By employing our RAM compiler, we get a 5-round protocol with proof size O(loglog n) for a family of problems including Fixed Automorphism, Clique and Leader Election (for the latter two problems we actually get O(1) proof size).

    * Finally, we discuss how to make these proofs non-interactive {em arguments} via random oracles.

    Our compilers capture many natural problems and demonstrate the difficulty in showing lower bounds in these regimes.
    Joint work with Moni Naor and Merav Parter.
    Lecture
  • Date:04MondayFebruary 2019

    Ph.D thesis defense: Electromechanical properties of Gd-doped ceria films free of mechanical constraints

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    Time
    15:00 - 16:30
    Location
    Perlman Chemical Sciences Building
    Room 404
    Lecturer
    Eran Mishuk
    Dept. Materials and Interfaces
    Organizer
    Department of Materials and Interfaces
    Contact
    AbstractShow full text abstract about Electrostriction is a second order electro-mechanical coupli...»
    Electrostriction is a second order electro-mechanical coupling that exists in all dielectrics. Classical electrostriction describes anharmonic perturbation of the chemical bonds in the lattice, which gives rise to changes in the average position of atoms. It was found that the mechanism of electrostriction in gadolinium doped ceria (CGO) is fundamentally different from that of classical electrostriction, in which high electrostriction goes together with a large dielectric constant. The mechanism of electrostriction in CGO is not known yet. However, the current hypothesis attributes it to rearrangement of local distortions in the fluorite lattice.
    This PhD thesis presents investigation of non-classical electrostriction effect in self-supported films of gadolinium doped ceria: dependence of the electrostriction strain coefficient on frequency and magnitude of the electric field and mechanical fatigue in thin films. Using self-supported Al/Ti/CGO/Ti/Al structure, I also identified electro-chemo-mechanical effect, which was previously considered unfeasible actuation mechanism at room temperature. The processes presented in this work provide a technological basis for integrating CGO as an active material in electro-active ceramic MEMS (microelectromechanical system)-actuation devices.
    Lecture
  • Date:05TuesdayFebruary 201907ThursdayFebruary 2019

    Soft semiconductors

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    Time
    08:00 - 08:00
    Location
    David Lopatie Conference Centre
    President's Auditorium
    Chairperson
    Omer Yaffe
    Contact
    Conference
  • Date:05TuesdayFebruary 2019

    Chaim Leib Pekeris 26th Memorial Lecture

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    Time
    10:30
    Location
    Dolfi and Lola Ebner Auditorium
    Lecturer
    Prof. Tim Roughgarden
    Columbia University
    Organizer
    Faculty of Mathematics and Computer Science
    Contact
    Lecture
  • Date:05TuesdayFebruary 2019

    The Chaim Leib Pekeris Memorial Lecture

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    Time
    11:00 - 12:30
    Title
    How Computer Science Informs Modern Auction Design
    Lecturer
    Tim Roughgarden
    Columbia University
    Organizer
    Faculty of Mathematics and Computer Science
    Faculty of Mathematical Sciences Seminar, Department of Computer Science and Applied Mathematics
    Faculty of Mathematical Sciences Seminar, Department of Mathematics
    Faculty of Mathematical Sciences Seminar
    Contact
    AbstractShow full text abstract about Over the last twenty years, computer science has relied on c...»
    Over the last twenty years, computer science has relied on concepts borrowed from game theory and economics to reason about applications ranging from internet routing to real-time auctions for online advertising. More recently, ideas have increasingly flowed in the opposite direction, with concepts and techniques from computer science beginning to influence economic theory and practice.
    In this lecture, Tim Roughgarden will illustrate this point with a detailed case study of the 2016-2017 Federal Communications Commission incentive auction for repurposing wireless spectrum. Computer science techniques, ranging from algorithms for NP-hard problems to nondeterministic communication complexity, have played a critical role both in the design of the reverse auction (with the government procuring existing licenses from television broadcasters) and in the analysis of the forward auction (when the procured licenses sell to the highest bidder).
    Lecture
  • Date:05TuesdayFebruary 2019

    The molecular mechanism of Respiratory Syncytial virus assembly

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    Time
    14:00 - 15:00
    Location
    Helen and Milton A. Kimmelman Building
    Dov Elad Room
    Lecturer
    Dr. Monika Bajorek
    from INRA, France
    Organizer
    Department of Structural Biology
    Contact
    Lecture
  • Date:06WednesdayFebruary 2019

    Developmental Club Series 2018-2019

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    Time
    10:00
    Location
    Arthur and Rochelle Belfer Building for Biomedical Research
    Botnar Auditorium
    Lecturer
    Prof. Oren Schuldiner
    Organizer
    Department of Molecular Genetics
    Developmental Club
    Contact
    Lecture
  • Date:06WednesdayFebruary 2019

    Field and Laboratory Studies of Ice Nucleation by Organic Aerosols: Insights on Phase Transitions and Glass Formation

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    Time
    11:00
    Location
    Sussman Family Building for Environmental Sciences
    M. Magaritz Seminar Room
    Lecturer
    Prof. Daniel Cziczo
    Earth, Atmospheric and Planetary Sciences Civil and Environmental Engineering Massachusetts Institute of Technology
    Organizer
    Department of Earth and Planetary Sciences
    Contact
    Lecture
  • Date:06WednesdayFebruary 2019

    Extension of in-situ nanoindentation results by (S)TEM graphical data processing

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    Time
    11:00 - 12:00
    Location
    Perlman Chemical Sciences Building
    Room 404
    Lecturer
    Dr. Vasily A. Lebedev
    Lomonosov Moscow State University, Moscow
    Organizer
    Department of Materials and Interfaces
    Contact
    AbstractShow full text abstract about Nanomechanical measurements allow us to determine mechanic...»

    Nanomechanical measurements allow us to determine mechanical characteristics of nano- and microobjects, which is required for further calculations of the mechanical parameters of the structures based on them. At the same time, in-situ measurements are carried out in the SEM and TEM chambers. Thus, it is possible to acquire graphic information that can supplement the indentation data.
    In this work, indentation of titania microspheres with different phase composition was tested by MEMS-based Hysitron PI-95 at Zeiss Libra 200MC TEM. Evaluation of the mechanical properties of microspheres in the elastic region was made according to the Hertz model. It turned out that annealing of the amorphous titania leads to an increase in the Young modulus, whereas the hydrothermal treatment reduces it from 27 to 4 Gpa. The differences in the destruction process was demonstrated for these kinds of particles. It has been shown, that hydrothermal treatment of titania microspheres leads to the formation of a reticular internal structure, whereas annealing results in sintering of the internal structure of microspheres.
    In the process of indentation, corresponding videos were also recorded, including the probe approach, indentation, and destruction of the microspheres. In order to process the videos we coded the program based on free Python packages. Using the Digital Image Correlation (DIC) algorithm, relative probe displacements were measured during indentation (Fig. 1a). The results obtained allowed us to clarify the calibration of the movement of the indenter in free sample tests, as well as to determine the drift function in real measurements. These results are important for long-term measurements, in particular creep tests.
    Based on graphical data we were able to determine the evolution of the shape of indented microspheres. During the video processing, areas of individual objects were determined, sizes of contact areas were calculated, and changes in linear dimensions of the deformed objects were determined (Fig. 1b). Therefore, a large amount of quantitative data was obtained from electron microscopy images.


    Fig.1 Illustration of probe displacement determination (a) and the shape evolution analysis
    Lecture
  • Date:07ThursdayFebruary 2019

    Chemical and Biological Physics Guest Seminar

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    Time
    11:00
    Title
    Interactions of hydrophobic nanoparticles with biological membrane
    Location
    Perlman Chemical Sciences Building
    Room 404
    Lecturer
    Prof. Matej Daniel
    Czech Technical University, Prague
    Organizer
    Department of Chemical and Biological Physics
    Contact
    AbstractShow full text abstract about Small hydrophobic gold nanoparticles with a diameter lower t...»
    Small hydrophobic gold nanoparticles with a diameter lower than the membrane thickness can form clusters or uniformly distribute within the hydrophobic core of the bilayer. The coexistence of two stable phases (clustered and dispersed) indicates the energy barrier between nanoparticles. It could be shown, that the forces between the nanoparticles embedded in the biological membrane could be either attractive or repulsive, depending on the mutual distance between them.
    Lecture
  • Date:07ThursdayFebruary 2019

    Frustrations in the treatment of Ovarian Cancer

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    Time
    14:00 - 15:00
    Title
    Special Guest Seminar
    Location
    Max and Lillian Candiotty Building
    Auditorium
    Lecturer
    Prof. Uziel Beller
    Shaare Zedek Medical Center Jerusalem & Assuata Ashdod
    Organizer
    Department of Biological Regulation
    Contact
    Lecture
  • Date:07ThursdayFebruary 2019

    Pelletron meeting - by invitation only

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    Time
    16:00 - 17:45
    Contact
    Lecture
  • Date:10SundayFebruary 2019

    Recovering exact conditions at semi-local DFT cost to mitigate energy and density errors for transition metal chemistry


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    Time
    14:00 - 15:00
    Location
    Perlman Chemical Sciences Building
    Room 404
    Lecturer
    Prof. Heather Kulik
    Dept. Chemical Engineering, MIT
    Organizer
    Department of Materials and Interfaces
    Contact
    AbstractShow full text abstract about Accurate prediction of electronic properties of open-shell t...»
    Accurate prediction of electronic properties of open-shell transition metal complexes is essential for materials design and catalysis. Nevertheless, the properties that make these materials and molecules so compelling also make them extremely challenging to study accurately with any computational model. Although density functional theory (DFT) remains the method of choice for its balance of speed and accuracy in computational screening, semi-local approximations in density functional theory (DFT), such as the generalized gradient approximation (GGA), suffer from many electron self-interaction errors that causes them to predict erroneous spin states and geometries, barrier heights and dissociation energies, and orbital energies, to name a few. I will outline our recent efforts to both understand and correct these errors with a focus on predictive modeling of transition metal chemistry : i) We describe how common approximations to recover the derivative discontinuity (i.e., DFT+U and global or range separated hybrids) affect the density properties of transition metal complexes and correlated solids with respect to exact references, ii) We demonstrate recovery of the flat-plane condition that is a union of the requirement of piecewise linearity with electron removal or addition as well as unchanged energy when changing the spin of an electron in isoenergetic orbitals. We accomplish this at no computational cost over semi-local DFT by building from scratch our judiciously-modified DFT (jmDFT) functionals designed to oppose errors inherent in semi-local functionals. We show the connection to but divergence of these functional forms from hybrid expressions and standard DFT+U explain why both common approximations increase static correlation errors. We also present fundamental expressions for determining these parameters, mitigating any empiricism in the method. iii) Finally, time permitting, I will describe our efforts to overcome DFT inaccuracies through the development of data-driven structure-method relationships, including in artificial neural networks that can predict sensitivity of spin-state ordering in transition metal complexes to changes in the exchange-correlation functional.



    Lecture
  • Date:11MondayFebruary 2019

    "Bio-organic systems for Electrocatalytic CO2 recycling"

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    Time
    11:00 - 12:15
    Location
    Camelia Botnar Building
    Lecturer
    Prof. Serdar Sariciftci
    Linz-Organic Photovoltaic Cells institute in thy Johannes Kepler University of Linz
    Organizer
    Faculty of Chemistry
    Contact
    Colloquia
  • Date:11MondayFebruary 2019

    To be announced

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    Time
    14:00 - 15:00
    Location
    Perlman Chemical Sciences Building
    Room 404
    Lecturer
    Prof. Yonatan Dubi
    Department of Chemistry & The Ilze-Katz Institute for Nano-Scale Science and Technology, BGU
    Organizer
    Department of Materials and Interfaces
    Contact
    Lecture
  • Date:12TuesdayFebruary 2019

    To be announced

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    Time
    10:00 - 10:30
    Location
    Nella and Leon Benoziyo Building for Biological Sciences
    Auditorium
    Lecturer
    Urmila Sehrawat
    Department of Biomolecular Sciences-WIS
    Organizer
    Department of Biomolecular Sciences
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    Lecture
  • Date:12TuesdayFebruary 2019

    To be announced

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    Time
    10:30 - 11:00
    Location
    Nella and Leon Benoziyo Building for Biological Sciences
    Auditorium
    Lecturer
    Ayelet Vardi
    Department of Biomolecular Sciences-WIS
    Organizer
    Department of Biomolecular Sciences
    Contact
    Lecture
  • Date:12TuesdayFebruary 2019

    Posing a contortionist E3 ubiquitin ligase for stepwise regulation of cell division

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    Time
    14:00 - 15:00
    Location
    Wolfson Building for Biological Research
    Lecturer
    Prof. Brenda Schulman
    Organizer
    Department of Structural Biology
    Contact
    Lecture
  • Date:13WednesdayFebruary 2019

    River Restoration – Regulatory point of view

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    Time
    13:00 - 14:00
    Title
    SAERI- Sustainability and Energy Research Initiative
    Location
    Nella and Leon Benoziyo Building for Biological Sciences
    Room 690
    Lecturer
    Alon Zask
    Senior Deputy Director General for Natural Resources Israel Ministry of Environmental Protection
    Organizer
    Feinberg Graduate School
    Alternative Sustainable Energy Research Initiative (AERI)
    Contact
    DetailsShow full text description of Host: Prof. Ron Milo light refreshments will be served at 1...»
    Host: Prof. Ron Milo
    light refreshments will be served at 12:40
    Lecture

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