TY - JOUR AB - Systems of three interacting particles are notorious for their complex physical behaviour. A landmark theoretical result in few-body quantum physics is Efimov\'s prediction1,2 of a universal set of bound trimer states appearing for three identical bosons with a resonant two-body interaction. Counterintuitively, these states even exist in the absence of a corresponding two-body bound state. Since the formulation of Efimov\'s problem in the context of nuclear physics 35 years ago, it has attracted great interest in many areas of physics3-8. However, the observation of Efimov quantum states has remained an elusive goal3,5. Here we report the observation of an Efimov resonance in an ultracold gas of caesium atoms. The resonance occurs in the range of large negative two-body scattering lengths, arising from the coupling of three free atoms to an Efimov trimer. Experimentally, we observe its signature as a giant three-body recombination loss9,10 when the strength of the two-body interaction is varied. We also detect a minimum 9,11,12 in the recombination loss for positive scattering lengths, indicating destructive interference of decay pathways. Our results confirm central theoretical predictions of Efimov physics and represent a starting point with which to explore the universal properties of resonantly interacting few-body systems7. While Feshbach resonances13,14 have provided the key to control quantum-mechanical interactions on the two-body level, Efimov resonances connect ultracold matter15 to the world of few-body quantum phenomena. AU - Kraemer, Tobias AU - Mark, Michael AU - Waldburger, Philipp AU - Danzl, Johann G AU - Chin, Cheng AU - Engeser, Bastian AU - Lange, Adam AU - Pilch, Karl AU - Jaakkola, Antti AU - Nägerl, Hanns AU - Grimm, Rudolf ID - 1033 IS - 7082 JF - Nature TI - Evidence for Efimov quantum states in an ultracold gas of caesium atoms VL - 440 ER - TY - CONF AB - Three interacting particles form a system which is well known for its complex physical behavior. A landmark theoretical result in few-body quantum physics is Efimov\'s prediction of a universal set of weakly bound trimer states appearing for three identical bosons with a resonant two-body interaction [1, 2]. Surprisingly, these states even exist in the absence of a corresponding two-body bound state and their precise nature is largely independent of the particular type of the two-body interaction potential. Efimov\'s scenario has attracted great interest in many areas of physics; an experimental test however has not been achieved. We report the observation of an Efimov resonance in an ultracold thermal gas of cesium atoms [3]. The resonance occurs in the range of large negative two-body scattering lengths and arises from the coupling of three free atoms to an Efimov trimer. We observe its signature as a giant three-body recombination loss when the strength of the two-body interaction is varied near a Feshbach resonance. This resonance develops into a continuum resonance at non-zero collision energies, and we observe a shift of the resonance position as a function of temperature. We also report on a minimum in the recombination loss for positive scattering lengths, indicating destructive interference of decay pathways. Our results confirm central theoretical predictions of Efimov physics and represent a starting point from which to explore the universal properties of resonantly interacting few-body systems. AU - Nägerl, Hanns AU - Kraemer, Tobias AU - Mark, Michael AU - Waldburger, Philipp AU - Danzl, Johann G AU - Engeser, Bastian AU - Lange, Adam AU - Pilch, Karl AU - Jaakkola, Antti AU - Chin, Cheng AU - Grimm, Rudolf ID - 1034 TI - Experimental evidence for Efimov quantum states VL - 869 ER - TY - CHAP AU - Harris, J. Robin AU - Almouzni, Geneviève AU - Kirschner, Doris AU - Dimitrova, Daniela AU - Nickerson, Jeffrey A. AU - Underwood, Jean AU - Wagner, Stefan AU - Korbei, Barbara AU - Foisner, Roland AU - Walther, Tobias C. AU - HETZER, Martin W AU - Peters, Reiner AU - Walev, Ivan AU - de Kroon, Anton I. P. M. AU - Staffhorst, Rutger W. H. M. AU - de Kruijff, Ben AU - Burger, Koert N. J. AU - Netto, Luis Eduardo Soares AU - Bertrand, Eric AU - Alimonti, Judie B. AU - Greenberg, Arnold H. AU - Xiao, Jinnan AU - Pradhan, Anuradha AU - Liu, Yuechueng AU - Paiement, Jacques AU - Young, Robin AU - Goñi, Félix M. AU - Villar, Ana-Victoria AU - Contreras, F.-Xabier AU - Alonso, Alicia AU - Peter, Brian J. AU - Mills, Ian G. AU - Higgins, Matthew K. AU - Brown, William J. AU - Chambers, K. AU - Doody, A. AU - Cheng, C. Yan AU - Mruk, Dolores D. AU - Yang, Chunhong AU - Kirchhoff, Helmut AU - Haase, Winfried AU - Boggasch, Stephanie AU - Paulsen, Harald AU - Benesova, Julie AU - Liffers, Sven-T. AU - Rögner, Matthias AU - Gao, Ya-sheng AU - Sztul, Elizabeth AU - Thiemann, Meinolf AU - Fahimi, H. Dariush AU - Gniadecki, Robert AU - Gajkowska, Barbara AU - Bane, Susan L. AU - Hess, John F. AU - Voss, John C. AU - Fitzgerald, Paul G. AU - Hisanaga, Shin-ichi AU - Sasaki, Takahiro AU - Uéda, Kenji AU - Town, Terrence AU - Tan, Jun AU - Milton, Nathaniel G. N. AU - Chi, Richard AU - Keller, Thomas C. S. AU - Kriajevska, Marina AU - Bronstein, Igor AU - Lukanidin, Eugene AU - Holmes, David F. AU - Kadler, Karl E. ED - Harris, Robin ED - Graham, John ED - Rickwood, David ID - 11119 SN - 9780470847589 T2 - Cell Biology Protocols TI - In Vitro Techniques ER - TY - JOUR AB - Over the last years it has become evident that the nuclear envelope (NE) is more than a passive membrane barrier that separates the nucleus from the cytoplasm. The NE not only controls the trafficking of macromolecules between the nucleoplasm and the cytosol, but also provides anchoring sites for chromosomes and cytoskeleton to the nuclear periphery. Targeting of chromatin to the NE might actually be part of gene expression regulation in eukaryotes. Mutations in certain NE proteins are associated with a diversity of human diseases, including muscular dystrophy, neuropathy, lipodistrophy, torsion dystonia and the premature aging condition progeria. Despite the importance of the NE for cell division and differentiation, relatively little is known about its biogenesis and its role in human diseases. It is our goal to provide a comprehensive view of the NE and to discuss possible implications of NE-associated changes for gene expression, chromatin organization and signal transduction. AU - D’Angelo, M. A. AU - HETZER, Martin W ID - 11117 IS - 3 JF - Cellular and Molecular Life Sciences KW - Cell Biology KW - Cellular and Molecular Neuroscience KW - Pharmacology KW - Molecular Biology KW - Molecular Medicine SN - 1420-682X TI - The role of the nuclear envelope in cellular organization VL - 63 ER - TY - JOUR AB - Nuclear pore complexes are multiprotein channels that span the double lipid bilayer of the nuclear envelope. How new pores are inserted into the intact nuclear envelope of proliferating and differentiating eukaryotic cells is unknown. We found that the Nup107-160 complex was incorporated into assembly sites in the nuclear envelope from both the nucleoplasmic and the cytoplasmic sides. Nuclear pore insertion required the generation of Ran guanosine triphosphate in the nuclear and cytoplasmic compartments. Newly formed nuclear pore complexes did not contain structural components of preexisting pores, suggesting that they can form de novo. AU - D'Angelo, Maximiliano A. AU - Anderson, Daniel J. AU - Richard, Erin AU - HETZER, Martin W ID - 11118 IS - 5772 JF - Science KW - Multidisciplinary SN - 0036-8075 TI - Nuclear pores form de novo from both sides of the nuclear envelope VL - 312 ER - TY - CONF AB - Broder et al.'s [3] shingling algorithm and Charikar's [4] random projection based approach are considered "state-of-the-art" algorithms for finding near-duplicate web pages. Both algorithms were either developed at or used by popular web search engines. We compare the two algorithms on a very large scale, namely on a set of 1.6B distinct web pages. The results show that neither of the algorithms works well for finding near-duplicate pairs on the same site, while both achieve high precision for near-duplicate pairs on different sites. Since Charikar's algorithm finds more near-duplicate pairs on different sites, it achieves a better precision overall, namely 0.50 versus 0.38 for Broder et al.'s algorithm. We present a combined algorithm which achieves precision 0.79 with 79% of the recall of the other algorithms. AU - Henzinger, Monika H ID - 11929 T2 - 29th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval TI - Finding near-duplicate web pages: A large-scale evaluation of algorithms ER - TY - JOUR AB - A Fourier transform technique is introduced for counting the number of solutions of holomorphic moment map equations over a finite field. This technique in turn gives information on Betti numbers of holomorphic symplectic quotients. As a consequence, simple unified proofs are obtained for formulas of Poincaré polynomials of toric hyperkähler varieties (recovering results of Bielawski-Dancer and Hausel-Sturmfels), Poincaré polynomials of Hubert schemes of points and twisted Atiyah-Drinfeld-Hitchin-Manin (ADHM) spaces of instantons on ℂ2 (recovering results of Nakajima-Yoshioka), and Poincaré polynomials of all Nakajima quiver varieties. As an application, a proof of a conjecture of Kac on the number of absolutely indecomposable representations of a quiver is announced. AU - Tamas Hausel ID - 1462 IS - 16 JF - PNAS TI - Betti numbers of holomorphic symplectic quotients via arithmetic Fourier transform VL - 103 ER - TY - JOUR AB - This note proves combinatorially that the intersection pairing on the middle-dimensional compactly supported cohomology of a toric hyperkähler variety is always definite, providing a large number of non-trivial L 2 harmonic forms for toric hyperkähler metrics on these varieties. This is motivated by a result of Hitchin about the definiteness of the pairing of L 2 harmonic forms on complete hyperkähler manifolds of linear growth. AU - Tamas Hausel AU - Swartz, Edward ID - 1461 IS - 8 JF - Proceedings of the American Mathematical Society TI - Intersection forms of toric hyperkähler varieties VL - 134 ER - TY - JOUR AB - Background: Cell-to-cell communication at the synapse involves synaptic transmission as well as signaling mediated by growth factors, which provide developmental and plasticity cues. There is evidence that a retrograde, presynaptic transforming growth factor-β (TGF-β) signaling event regulates synapse development and function in Drosophila. Results: Here we show that a postsynaptic TGF-β signaling event occurs during larval development. The type I receptor Thick veins (Tkv) and the R-Smad transcription factor Mothers-against-dpp (Mad) are localized postsynaptically in the muscle. Furthermore, Mad phosphorylation occurs in regions facing the presynaptic active zones of neurotransmitter release within the postsynaptic subsynaptic reticulum (SSR). In order to monitor in real time the levels of TGF-β signaling in the synapse during synaptic transmission, we have established a FRAP assay to measure Mad nuclear import/export in the muscle. We show that Mad nuclear trafficking depends on stimulation of the muscle. Conclusions: Our data suggest a mechanism linking synaptic transmission and postsynaptic TGF-β signaling that may coordinate nerve-muscle development and function. AU - Dudu, Veronika AU - Bittig, Thomas AU - Entchev, Eugeni AU - Kicheva, Anna AU - Julicher, Frank AU - González Gaitán, Marcos ID - 1715 IS - 7 JF - Current Biology TI - Postsynaptic mad signaling at the Drosophila neuromuscular junction VL - 16 ER - TY - JOUR AB - SiGe islands grown by deposition of 10 monolayers of Ge on Si(0 0 1) at 740 °C were investigated by using a combination of selective wet chemical etching and atomic force microscopy. The used etchant, a solution consisting of ammonium hydroxide and hydrogen peroxide, shows a high selectivity of Ge over SixGe1-x and is characterized by relatively slow etching rates for Si-rich alloys. By performing successive etching experiments on the same sample area, we are able to gain a deeper insight into the lateral displacement the islands undergo during post growth annealing. AU - Georgios Katsaros AU - Rastelli, Armando AU - Stoffel, Mathieu AU - Isella, Giovanni AU - Von Känel, Hans AU - Bittner, Alexander M AU - Tersoff, Jerry AU - Denker, Ulrich AU - Schmidt, Oliver G AU - Costantini, Giovanni AU - Kern, Klaus ID - 1745 IS - 12 JF - Surface Science TI - Investigating the lateral motion of SiGe islands by selective chemical etching VL - 600 ER -