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פברואר 01, 2010

  • Date:03שלישימאי 2011

    p53, a novel regulator of lipid metabolism pathways

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    שעה
    12:15 - 12:15
    מיקום
    בניין וולפסון למחקר ביולוגי
    מרצהIdo Goldstein
    מארגן
    המחלקה לביולוגיה מולקולרית של התא
    צרו קשר
    תקצירShow full text abstract about Maintaining normal lipid homeostasis is crucial for every bi...»
    Maintaining normal lipid homeostasis is crucial for every biological system. Although the transport of lipids in circulation in the form of lipoprotein complexes is an elaborate process orchestrated mainly by the liver, the molecular underpinnings of hepatic lipoprotein regulation are not entirely resolved. In this study, we identify a
    novel role for the p53 protein in regulating lipid and lipoprotein metabolism, a process not conceptually conceived as related to p53, which is known mainly in its tumor suppressive functions. Gene expression microarray analysis revealed a group of 341 genes whose expression was induced by p53 in the liver-derived cell line HepG2.
    Twenty of these genes encode proteins involved in many aspects of lipid homeostasis, especially lipoprotein metabolism. The mode of regulation of three representative genes (pltp, abca12 and cel) was further characterized. In addition to HepG2, the genes were induced in a p53-dependent manner in other cell types namely Hep3B cells, mouse hepatocytes, human liver cells and fibroblasts. Furthermore, p53 was found to bind to their promoter in designated p53 responsive elements (as measured by chromatin immunoprecipitation) and was able to increase the transcription of a reporter gene located downstream of the genes' promoters. Of note, p53 induced a significant elevation in the protein level of PLTP and CEL. Importantly, p53 augmented the activity of secreted PLTP, which plays a major role in lipoprotein biology and atherosclerosis pathology. These findings expose another layer of p53 functions unrelated to tumor suppression and render it a novel regulator of hepatic lipid metabolism and consequently of systemic lipid homeostasis and atherosclerosis development.
    הרצאה
  • Date:03שלישימאי 2011

    "Aristrocrats" - Cameri Theater

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    שעה
    20:30 - 20:30
    מיקום
    אודיטוריום מיכאל סלע
    צרו קשר
    אירועי תרבות
  • Date:04רביעימאי 2011

    Forum on Mathematical Principles in Biology

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    שעה
    10:00 - 11:00
    כותרת
    A design principle for protein promiscuity
    מיקום
    בניין ארתור ורושל בלפר למחקר ביורפואי
    מרצהDima Lukatsky
    מארגן
    המחלקה לביולוגיה מולקולרית של התא
    צרו קשר
    הרצאה
  • Date:04רביעימאי 2011

    Fast Spectral Algorithms for Graph Partitioning and Graph Decomposition

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    שעה
    11:00 - 11:00
    מיקום
    Ziskind Bldg.
    מרצהNisheeth Vishnoi
    Microsoft Research India
    מארגן
    הפקולטה למתמטיקה ומדעי המחשב
    הרצאה
  • Date:04רביעימאי 2011

    Predictive Sparse Coding:A Dynamical Circuit Model of Early Sensory Processing

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    שעה
    12:30 - 12:30
    מיקום
    אולם הרצאות ע"ש גרהרד שמידט
    מרצהProf. Dmitri Chklovskii
    Janelia Farm, HHMI, USA
    מארגן
    המחלקה למדעי המוח
    צרו קשר
    תקצירShow full text abstract about In early sensory systems, such as retina and olfactory bulb ...»
    In early sensory systems, such as retina and olfactory bulb in vertebrates or optic and antennal lobes in invertebrates, information about the world converges from a large number of receptors onto a much smaller number of projection neurons. Such bottleneck in the communication channel to the higher brain areas (Attneave, 1954, Barlow & Levick, 1976) can be overcome for sensory stimuli containing correlations by the predictive coding strategy (Srinivasan et al, 1982). In case of the retina, instantaneous subtraction of the least squares prediction compresses information and results in center-surround biphasic receptive fields. However, explaining variation of receptive fields with SNR (Srinivasan et al, 1982, Van Hateren, 1992, Atick & Redlich, 1990) would require circuit re-wiring which is unlikely on short time scales. Here we develop the predictive coding idea by proposing that a non-linear recurrent neuronal circuit can implement predictive coding adaptively: stimuli of different SNR result in different inhibitory surrounds. We solve the transient dynamics of this circuit in response to a step-like stimulus and demonstrate that it communicates a residual of the regularization path to higher brain areas. Thus, we are able to map a non-trivial computation on a concrete neuronal circuit and provide a theoretical framework to understand neural coding for many physiological experiments.
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  • Date:04רביעימאי 2011

    "Aristrocrats" - Camari Theater

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    שעה
    20:30 - 20:30
    מיקום
    אודיטוריום מיכאל סלע
    צרו קשר
    אירועי תרבות
  • Date:05חמישימאי 2011

    Uniqueness and non-uniqueness for stochastic heat equations with H"older continuous coefficients

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    שעה
    11:00 - 11:00
    מיקום
    Ziskind Bldg.
    מרצהLeonid Mytnik
    Technion
    מארגן
    הפקולטה למתמטיקה ומדעי המחשב
    הרצאה
  • Date:05חמישימאי 2011

    TBA

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    שעה
    11:15 - 12:30
    מיקום
    בניין הפיזיקה ע"ש עדנה וק.ב. וייסמן
    מרצהProf. Elad Schneidman
    Department of Neurobiology
    מארגן
    הפקולטה לפיזיקה
    צרו קשר
    הרצאה
  • Date:05חמישימאי 2011

    Optimal population coding by noisy spiking neurons

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    שעה
    11:15 - 12:30
    מיקום
    בניין הפיזיקה ע"ש עדנה וק.ב. וייסמן
    מרצהProf. Elad Schneidman
    Weizmann
    מארגן
    הפקולטה לפיזיקה
    צרו קשר
    תקצירShow full text abstract about The In different neural systems, the collective activity of...»
    The In different neural systems, the collective activity of populations of neurons responding to natural-istic stimuli is well described by second order “maximum entropy” or Ising models. We asked, how should such interactions in the network be organized to maximize the amount of information represent-ed in population responses about the stimulus it was presented with? To this end, we extended the line-ar-nonlinear Poisson model of single neurons to include pairwise interactions, yielding a stimulus de-pendent, pairwise maximum entropy model. We found that as we varied the noise level in single neurons and the distribution of network inputs, the optimal pairwise interactions smoothly interpolated to achieve network functions that are usually regarded as discrete – stimulus decorrelation, error correc-tion, and independent encoding. These functions reflected a tradeoff between efficient consumption of finite neural bandwidth, and the use of redundancy to mitigate noise. Spontaneous activity in the optimal network reflected stimulus induced activity patterns, and single neuron response variability overes-timated network noise. Our analysis suggests that rather than having a single coding principle hardwired in their architecture, networks in the brain should adapt their function to changing noise and stimulus correlations. Initial results from the vertebrate retina indeed show how it relies on the network’s ‘ground states’ to encode information about the stimulus to the brain.
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  • Date:05חמישימאי 2011

    A Universal and Exact Linear Framework for Estimation Registration and Recognition of Deformable Objects

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    שעה
    12:00 - 12:00
    מיקום
    Ziskind Bldg.
    מרצהJoseph M. Francos
    Ben-Gurion University
    מארגן
    הפקולטה למתמטיקה ומדעי המחשב
    הרצאה
  • Date:05חמישימאי 2011

    Modeling the early steps of viral infection and analysis of cytoplasmic viral trajectories

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    שעה
    14:15 - 14:15
    כותרת
    Astro Room
    מיקום
    בניין הפיזיקה ע"ש עדנה וק.ב. וייסמן
    מרצהDavid Holcman
    Ecole Normale Superieure, France
    מארגן
    המחלקה לפיזיקה של מערכות מורכבות
    צרו קשר
    תקצירShow full text abstract about Most viruses enter the cell through an endocytic pathway and...»
    Most viruses enter the cell through an endocytic pathway and subsequently travel through the cytoplasm inside an endosomal compartment before reaching the nucleus. To pursue their fate, viruses have to escape the endosome and deliver their genetic payload in the cytoplasm before being degraded. Although the escape process relies on the conformational changes of glycoproteins involved in membrane fusion, the details are still missing. To examine the escape dynamics, we first present a biophysical model and mathematical analysis to study cytoplasmic trafficking and the mean first passage time to reach any nuclear pores. Using Markov Jump processes, we then estimate the time for glycoproteins to change conformation and reach their fusogenic state, leading to fusion and viral escape from an endosome. We shall study separately the case of enveloped (influenza) and non-enveloped viruses (Adeno-Associated Virus). Finally, we will present a preliminary analysis to discriminate binding from crowding of recent acquired viral trajectories and we will finish by presenting some simulations of stochastic viral trajectories in a reconstituted EM picture of a cell.
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  • Date:08ראשוןמאי 2011

    "Biomineralization strategies in the acorn barnacle Balanus amphitrite"

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    שעה
    10:00 - 12:00
    מיקום
    המשכן ללימודי מוסמכים על-שם דוד לופאטי
    מרצהGal Mor Khalifa
    M.Sc. student of Prof. Lia Addadi & Prof. Stephen Weiner Department of Structural Bioloy, WIS
    מארגן
    המחלקה לביולוגיה מבנית וכימית
    צרו קשר
    הרצאה
  • Date:08ראשוןמאי 2011

    Property Testing Lower Bounds via Communication Complexity

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    שעה
    11:00 - 11:00
    מיקום
    Ziskind Bldg.
    מרצהKevin Matulef
    IIIS, Tsinghua University
    מארגן
    הפקולטה למתמטיקה ומדעי המחשב
    הרצאה
  • Date:08ראשוןמאי 2011

    The geological input of the Japan happenings and a look at our region

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    שעה
    11:00 - 11:00
    מיקום
    בניין משפחת זוסמן
    מרצהProf. Emanuel Mazor
    Weizmann Institute of Science Environmental Sciences Dept.
    מארגן
    המחלקה למדעי כדור הארץ וכוכבי הלכת
    צרו קשר
    הרצאה
  • Date:08ראשוןמאי 2011

    Journal club - A discussion on selected articles

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    שעה
    12:30 - 14:00
    מיקום
    מעבדה על-שם דני נ. היינמן
    מרצהDr. Nir Sapir
    מארגן
    מרכז לאסטרופיסיקה עש נלה וליאון בנוזיו
    צרו קשר
    הרצאה
  • Date:08ראשוןמאי 2011

    To be announced

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    שעה
    13:00 - 13:00
    מיקום
    בניין ארתור ורושל בלפר למחקר ביורפואי
    מרצהEfrat Dvash
    Menachem Rubinstein's group Dept. of Molecular Genetics, WIS
    מארגן
    המחלקה לגנטיקה מולקולרית
    צרו קשר
    הרצאה
  • Date:08ראשוןמאי 2011

    Sphingosine-1-phosphate: frpom insipid lipid to a regulator of cancer and inflammation

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    שעה
    14:00 - 14:00
    מיקום
    בניין ע"ש מקס ולילאן קנדיוטי
    מרצהProf. Sarah Spiegel
    Dept. Biochemistry and Molecular Biology Virginia Commonwealth University School of Medicine Richmond, VA. USA
    מארגן
    המחלקה לאימונולוגיה ורגנרציה ביולוגית
    צרו קשר
    הרצאה
  • Date:09שנימאי 2011

    טקס יום הזיכרון לחללי מערכות ישראל ולנפגעי פעולות האיבה

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    שעה
    11:00 - 12:45
    מיקום
    בניין הלן ומילטון קימלמן
    צרו קשר
    אירועי תרבות
  • Date:11רביעימאי 2011

    Lumen formation in the Drosophila heart

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    שעה
    10:00 - 10:00
    מיקום
    בניין ארתור ורושל בלפר למחקר ביורפואי
    מרצהProf. Talila Volk
    Dept. of Molecular Genetics, WIS
    צרו קשר
    הרצאה
  • Date:11רביעימאי 2011

    Faculty of Chemistry Colloquium- Prof. Harold Kroto

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    שעה
    11:00 - 12:30
    כותרת
    CARBON IN NANO AND OUTER SPACE
    מיקום
    אולם הרצאות ע"ש גרהרד שמידט
    מרצהProf. Harold Kroto
    Nobel Laureate for the discovery of the C60 Dept. of Chemistry & Biochemistry The Florida State University
    מארגן
    הפקולטה לכימיה
    צרו קשר
    תקצירShow full text abstract about The age-old awe that man has had for the heavens has driven ...»
    The age-old awe that man has had for the heavens has driven almost all aspects of human culture and knowledge and resulted in technologies with generally positive, though occasionally negative effect. Arguably the most positive have taken place since Galileo recognized that the phases of Venus provided the evidence that confirmed the Copernican heliocentric system and cemented his position firmly as the “Father of Science”. From this moment on we had, at long last, a straightforward philosophical construct and language which enabled mankind to determine what is and is not “True”. Particularly important truths have resulted from the curiosity that humans have had for a detailed understanding of the way Universe works. This led to the development of astrophysics and the associated technologies that have been spun-off. Not least of these has been the telescope – from Galileo’s beautiful original design to the fantastic satellite-born devices put up by NASA. These have not only enabled us to observe the planets and stars more clearly but we have been able to see to the very edge of the Universe and make a plethora of discoveries about all aspects of the Universe from the occupants of the space between stars to the processes occurring deep inside stars. Perhaps the most fundamental advance based on space observations led to the development of Classical Mechanics in order to understand the motions of the planets and comets and concommitantly the development Calculus, one of the greatest of Mathematical achievements. As Quantum Mechanics developed along with Spectroscopy it was inevitable that we should start to study the atomic and molecular composition of heavenly bodies - first hot stars as well as cool comets. With the development of radiotelescopes, the very cold interstellar medium was found to be a veritable Pandora's Box, full to the brim with fascinating and exotic molecules, dust particles and also some highly puzzling material responsible for some as yet unidentified spectroscopic features. These latter are known as the Diffuse Interstellar Bands (DIBs) first observed in the 1920s.

    Particularly fascinating, curious and crucial has been the role that the element carbon has played in almost every aspect of the development of our understanding of both the physical and natural sciences. The fact that the element is at all abundant is due to a curious set of coincidences involving its nucleosynthesis from helium in stars. If one furthermore adds into the overall carbon equation its uniquely profuse chemistry, ie Organic Chemistry, it is hard to conceive that life could be based on any other element. The most recent big surprise that the element had up its sleeve was the existence of C60, Buckminsterfullerene, the third well-defined form of carbon. The discovery was made serendipitously in 1985 during laboratory experiments which attempted to explain the chemical synthesis of some unusually long linear carbon chain molecules detected in the interstellar medium in the 1970’s. A second aim of these experiments involved curiosity as to whether the carriers of the DIBs might be long linear carbon chains. Interestingly the extraction of C60 in 1990 by Kraetschmer and Huffman resulted from experiments aimed at understanding another mysterious feature known as the 217nm hump and conjectured to also involve carbon – perhaps carbonaceous dust particles. The fact that this third, well-defined, form of carbon had been hiding in the shadows since time immemorial brings to mind the mysterious character lurking in the dark streets of Vienna, made famous by Orson Welles in the classic movie “The Third Man”. In fact we now know that the molecule forms fleetingly within sooting flames but is immediately destroyed as it passes through the flame barrier into an oxygen atmosphere. On the basis of such revelations the suggestion that C60 might exist in space and be responsible for the DIBs (Kroto & Jura) seemed an as good, if not a better, possibility than most other ideas that had heretofore been proposed. Especially compelling support for the idea that C60 existed in space lay in the fact that the original discovery was made serendipitously during laboratory experiments designed to simulate the atmospheric conditions in cool red giant carbon stars. This conjecture has just been confirmed by Cami et al who have found infra red bands in the spectra obtained by NASA’s Spitzer satellite telescope. The discovery also makes some recent work here at FSU on endohedral fullerenes, in which atoms are trapped inside the carbon cage, extremely relevant to certain anomalous isotope ratios observed in meteorites, in particular carbonaceous chondrites. This is yet another example of the remarkably synergistic relationship between terrestrial and space science. In these difficult times it lends useful support for the fundamental value of "Blue Skies" or perhaps more accurately “Black Skies” cross-disciplinary research. All these results taken together suggest that the 90 year-old mystery of the carrier of the DIBs might be close to being resolved at long last.
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