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April 27, 2017
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Date:18MondayDecember 2017Lecture
Turbulence in a Localized Puff in a Pipe
More information Time 14:15 - 14:15Location Edna and K.B. Weissman Building of Physical SciencesLecturer Prof. Alex Yakhot
Department of Mechanical Engineering Ben-Gurion UniversityOrganizer Department of Physics of Complex SystemsContact Abstract Show full text abstract about We have performed direct numerical simulations of transient ...» We have performed direct numerical simulations of transient turbulence in pipe flow for Re=2,250 which is established as a threshold of an equilibrium puff. We investigate the structure of an individual puff by considering three-dimensional snapshots across a long time-period. To assimilate the velocity data, we apply a conditional sampling based on the location of the maximum energy of the transverse (turbulent) motion. Specifically, at each time instance, we follow a turbulent puff by a three-dimensional moving-window centered at that location. We collected a snapshot-ensemble of the velocity fields acquired over 10,000 time instances (snapshots) inside the moving-window. The considered fow is intermittent and transitional. The velocity field inside the puff shows the dynamics of a developing turbulence. The localized puff is about of 12-15 pipe diameters long with almost laminar trailing and leading edges. In the puff core, despite the low Reynolds number, along the moving-window, it takes the downstream short distance of several pipe diameters to form the state of developed turbulence, when the turbulence statistics becomes similar to fully-developed turbulent pipe flow; the velocity profile becomes flat in the pipe core and logarithmic near the wall. It is shown that this “fully-developed turbulent slot” is very narrow, about two pipe diameters; it is localized and moves with a puff. -
Date:18MondayDecember 2017Academic Events
Life Sciences Faculties' Council
More information Time 15:00 - 18:00Location The David Lopatie Conference CentreContact -
Date:19TuesdayDecember 201721ThursdayDecember 2017Conference
Israel-Turkey meeting on nanoscale science
More information Time 08:00 - 08:00Location The David Lopatie Conference CentreChairperson Reshef TenneHomepage -
Date:19TuesdayDecember 2017Lecture
Frontiers in Systems Biology
More information Time 10:00 - 11:00Title Modulating TranslationLocation Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Prof. Mihaela Zavolan
Biozentrum, University of Basel, SwitzerlandOrganizer Azrieli Institute for Systems BiologyContact Abstract Show full text abstract about In yeast, the knock out of individual ribosomal protein (RP)...» In yeast, the knock out of individual ribosomal protein (RP) genes
leads to a wide range of life span phenotypes, some mutants having
significantly increased, other significantly decreased life span. In
this talk I would like to present our efforts in characterizing the
regulation of mRNA translation in relation to cellular states, from
yeast to man. I will describe our work on inferring determinants of
protein synthesis rates in yeast, where we found that the Gcn4
transcription factor, which is induced in many conditions that enhance
yeast lifespan (RP gene knockout, calorie restriction, mTOR
inhibition) not only activates transcription of amino acid
biosynthesis genes, but also represses protein biosynthesis. How much
variation in RP expression is expected in human tissues has been
largely unknown, but RP gene mutations have been described in
association with hematological disorders. Through a comprehensive
analysis of human RP mRNAs expression pattern across 28 tissues, over
300 primary cells and 16 tumor types, we identified many RPs which
exhibit tissue-specific expression. In the hematopoietic system, a
small number of RP genes, possible regulated by transcription factors
with tissue-specific expression, unequivocally discriminate cells of distinct
lineages and developmental stages. Different cancer types also show
dysregulated expression of individual RPs, some RPs having a relative
increase and other decrease in expression. Finally, I will discuss our efforts
in mapping sites of snoRNA-guided RNA modifications.
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Date:19TuesdayDecember 2017Lecture
The control on Phosphatidylserine exposure during axonal degeneration
More information Time 10:00 - 10:30Location Nella and Leon Benoziyo Building for Biological SciencesLecturer Dr. Vered Shacham
Members - Dept. of Biomolecular Sciences-WISOrganizer Department of Biomolecular SciencesContact Abstract Show full text abstract about During developmental pruning or in response to injury, axona...» During developmental pruning or in response to injury, axonal remnants of degenerated axons are engulfed by local or professional phagocytes. While several engulfment receptors have been implicated in the recognition of axon remnants, the signal that marks degenerating axons for phagocytosis, as well as the intrinsic mechanism that controls its exposure, are poorly understood. We used a series of in vitro assays to show that Phosphatidylserine (PS), a known “eat me” signal, is exposed on axons undergoing pruning or Wallerian degeneration. Importantly, we demonstrate that PS exposure is spatially controlled on sub-axonal segments undergoing degeneration and masking PS hinders the engulfment of axonal debris. Our results also show that PS exposure is regulated by the upstream activators of axonal pruning and Wallerian degeneration. However, our investigation of signaling further downstream revealed divergence between axon degeneration and PS exposure. Overall, our results suggest that the levels of PS on the outer axonal membrane can be dissociated from the degeneration process and that PS serves as an axonal “eat me” signal for engulfment. -
Date:19TuesdayDecember 2017Lecture
T-cell immune suppression by the cytoplasmic tail of the HIV gp41 fusion protein
More information Time 10:30 - 11:00Location Nella and Leon Benoziyo Building for Biological SciencesLecturer Yoel A. Klug
Members - Dept. of Biomolecular Sciences-WISOrganizer Department of Biomolecular SciencesContact Abstract Show full text abstract about HIV enters its host cells by membrane fusion, initiated by t...» HIV enters its host cells by membrane fusion, initiated by the gp41 subunit of its envelope protein. In addition, gp41 has been shown to prevent T-cell activation. This is suggested to occur during the membrane fusion process and is attributed to various membrane binding regions of gp41. Although extensively studied, the cytosolic region of gp41, termed the cytoplasmic tail (CT), has not been examined in the context of immune suppression. Here we investigated whether the CT inhibits T-cell activation by utilizing gp41 derived peptides and full gp41 constructs expressed in human T-cells. We found that a conserved region of the CT specifically inhibits T-cell activation through a unique inhibitory mechanism able to take place post membrane fusion.
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Date:19TuesdayDecember 2017Lecture
SPACE OF FIELD THEORIES, UV COMPLETENESS, AND INTEGRABILITY
More information Time 10:30 - 10:30Location Newe ShalomLecturer A. ZAMOLODCHIKOV
(STONY BROOK)Organizer Department of Particle Physics and AstrophysicsContact -
Date:19TuesdayDecember 2017Lecture
Bacteria and the future of agriculture: from sequence to function
More information Time 11:30 - 11:30Location Nella and Leon Benoziyo Building for Biological SciencesLecturer Dr. Asaf Levy
Microbial Program The Lawrence Berkeley National Laboratory (LBL) US DOE (Department of Energy) Joint Genome Institute managed by University of California, USAOrganizer Department of Plant and Environmental SciencesContact -
Date:19TuesdayDecember 2017Lecture
AMPLITUDES AND HIDDEN SYMMETRIES IN N=2 CHERN-SIMONS MATTER THEORY
More information Time 12:00 - 12:00Location Newe ShalomLecturer KARTHIK INBASEKAR
TAUOrganizer Department of Particle Physics and AstrophysicsContact Abstract Show full text abstract about Abstract: Chern-Simons theories coupled to matter have a wid...» Abstract: Chern-Simons theories coupled to matter have a wide variety of applications ranging from anyonic physics to quantum gravity via the AdS/CFT correspondence. These theories enjoy a strong-weak duality that has been tested to a very good accuracy via large N computations. Scattering amplitudes are some of the most basic observables in QFT's. S matrices computed to all orders in the 't Hooft coupling serve as important testing grounds for the strong-weak duality. Although beginning with 4 point amplitudes this is doable, the complexity of the problem increases with the number of external legs. As a first step towards computing all loop arbitrary n point amplitudes, we address the problem of computing arbitrary n point tree level amplitudes. We show that BCFW recursion relations can be used to compute all tree level scattering amplitudes in terms of $2
ightarrow2$ scattering amplitude in $U(N)$ ${mathcal N}=2$ Chern-Simons (CS) theory coupled to matter in fundamental representation. As a byproduct, we also obtain a recursion relation for the CS theory coupled to regular fermions, even though in this case standard BCFW deformations do not have a good asymptotic behavior. We then proceed to take the first steps towards all loop computations of arbitrary n point amplitudes. As a first step we explain the result of arXiv:1505.06571, where it was shown that the $2
ightarrow 2$ scattering is tree level exact to all orders except in the anyonic channel, where it gets renormalized by a simple function of 't Hooft coupling. We show that tree level $2 o 2$ scattering amplitudes in 3d ${cal N}=2$ Chern-Simons theory coupled to a fundamental chiral multiplet are dual superconformal invariant. We further show that the large $N$ all loop exact amplitude also has dual superconformal symmetry, which implies dual superconformal symmetry is all loop exact which is in contrast to other known highly supersymmetric examples such as ${cal N}=4$ SYM and ABJM where the dual superconformal symmetry is in general anomalous. The presence of superconformal and dual superconformal symmetry indicate the existence of a Yangian symmetry, further providing indications that the N=2 theory may be integrable. -
Date:19TuesdayDecember 2017Lecture
"How changes to the cellular environment modulate protein structure, function, and interaction"
More information Time 14:00 - 15:00Location Helen and Milton A. Kimmelman BuildingLecturer Dr. Shahar Sukenik
University of IllinoisOrganizer Department of Chemical and Structural BiologyContact -
Date:20WednesdayDecember 2017Lecture
Developmental Club Series 2017-2018
More information Time 10:00 - 11:00Title "How a key interface between the brain’s neuro-hormonal and vascular systems is assembled"Location Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Prof. Gil Levkowitz Organizer Department of Molecular GeneticsContact -
Date:21ThursdayDecember 2017Lecture
The Dipole Polarizability of a Water Molecule in the Condensed Phase
More information Time 10:00 - 11:00Location Michael Sela AuditoriumLecturer Prof. Robert DiStasio Jr.
Dept. of Chemistry and Chemical Biology, Cornell UniversityOrganizer Department of Molecular Chemistry and Materials ScienceContact -
Date:21ThursdayDecember 2017Colloquia
Quantization of heat flow in the fractional quantum Hall regime
More information Time 11:15 - 12:30Location Edna and K.B. Weissman Building of Physical SciencesLecturer TBA Organizer Faculty of PhysicsContact Abstract Show full text abstract about Quantum mechanics sets an upper bound on the amount of charg...» Quantum mechanics sets an upper bound on the amount of charge flow as well as on the amount of heat flow in ballistic one-dimensional channels. The two relevant upper bounds, which combine only fundamental constants, are the quantum of the electrical conductance, Ge=e2/h, and the quantum of the thermal conductance, Gth=0T=(π2kB2/3h)T. Remarkably, the latter does not depend on the particles charge, particles exchange statistics, and is expected also to be insensitive to the interaction strength among the particles. However, unlike the relative ease in observing the quantization of the electrical conductance, measuring accurately the thermal conductance is more challenging.
The universality of the Gth quantization in 1D ballistic channels was demonstrated for weakly interacting particles: phonons [1], photons [2], and in an electronic Fermi-liquid [3]. I will describe our recent experiments with heat flow in a strongly interacting system of 2D electrons in the fractional quantum Hall regime. In the lowest Landau level we studied particle-like states (v -
Date:21ThursdayDecember 2017Lecture
"Gender in practice: the user’s guide"
More information Time 11:30 - 13:00Location Gerhard M.J. Schmidt Lecture HallLecturer Dr. Zeev Lehrer Contact Abstract Show full text abstract about Dr. Zeev Lehrer presents a different, practical point of vie...» Dr. Zeev Lehrer presents a different, practical point of view on the confluence between gender and organizations. Suspending questions of justice, responsibility and blame, Lehrer supplies simple and practical tools to manage and solve real gender problems in real life situations. -
Date:24SundayDecember 2017Conference
From perception to action: imaging human brain function
More information Time 08:30 - 13:30Location The David Lopatie Conference CentreChairperson Alon ChenOrganizer Department of Brain SciencesHomepage -
Date:24SundayDecember 2017Lecture
Looking for the right approach of renewable energy utilization
More information Time 13:00 - 13:00Title SAERI: Sustainability And Energy Research InitiativeLocation Gerhard M.J. Schmidt Lecture HallLecturer Prof. Jacob Karni
Department of Earth and Planetary Sciences, The Weizmann Institute of ScienceOrganizer Weizmann School of ScienceContact -
Date:24SundayDecember 2017Lecture
Departmental Seminar
More information Time 13:00 - 14:00Title Discovering a cancer-associated mutation in autophagy and deciphering its functional implicationLocation Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Gal Nuta Organizer Department of Molecular GeneticsContact -
Date:25MondayDecember 2017Colloquia
"Organic Semiconductors: from Small Molecules to 2D Polymers"
More information Time 11:00 - 12:15Location Gerhard M.J. Schmidt Lecture HallLecturer Prof. Dmitrii Perepichka
McGill UniversityOrganizer Faculty of ChemistryContact -
Date:25MondayDecember 2017Lecture
Cell-free circulating tumour DNA as a non-invasive tool for cancer diagnostics and research
More information Time 14:00 - 15:00Title Cancer Research ClubLocation Max and Lillian Candiotty BuildingLecturer Prof. Nitzan Rosenfeld
Cancer Research UK, Cambridge Institute University of Cambridge, UKOrganizer Department of Immunology and Regenerative BiologyContact Abstract Show full text abstract about Cancer is driven by genomic alterations, and can evolve in r...» Cancer is driven by genomic alterations, and can evolve in response to selective pressures. Sampling of tumour material however is a limiting factor for both diagnostics and research. Blood plasma contains cell-free fragments of circulating tumour DNA (ctDNA) that can be collected non-invasively. With advanced genomic techniques this becomes an effective source of information. “Liquid biopsy” assays are now entering clinical use for non-invasive molecular profiling of advanced cancers to guide targeted therapy. Serially-collection plasma samples can be used to track response to treatment, cancer progression and emergence of known or new resistance mechanisms. Methods that can detect minute amounts of ctDNA are being used to study early-stage cancer and for detection of minimal residual disease after initial definitive treatment. -
Date:25MondayDecember 2017Lecture
The QTY Code: A simple tool for membrane protein engineering. Subtitle: (Can you convert a hydrophobic alpha helix into a hydrophilic one?)
More information Time 14:00 - 15:00Location Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Prof. Shuguang Zhang
Center for Biomedical Engineering, MITOrganizer Department of Chemical and Structural BiologyContact Abstract Show full text abstract about Structure and function studies of membrane proteins, particu...» Structure and function studies of membrane proteins, particularly G protein-coupled receptors (GPCRs) and multiple segment transmembrane proteins, require detergents. Without detergents these integral membrane proteins aggregate and are nearly impossible to analyze. We have devised a useful tool, the QTY Code, for engineering hydrophobic domains to become detergent-free, namely water-soluble, without significantly altering protein structure and function. Here we report using the QTY Code (glutamine, threonine and tyrosine) to systematically replace the hydrophobic amino acids leucine, valine, isoleucine and phenylalanine in the four chemokine receptors CCR5, CXCR4, CCR10 and CXCR7. Our simple QTY Code is a useful tool and has implications for engineering water-soluble variants of previously water-insoluble and perhaps aggregated proteins including amyloids.