--- _id: '7775' abstract: - lang: eng text: As a function of packing fraction at zero temperature and applied stress, an amorphous packing of spheres exhibits a jamming transition where the system is sensitive to boundary conditions even in the thermodynamic limit. Upon further compression, the system should become insensitive to boundary conditions provided it is sufficiently large. Here we explore the linear response to a large class of boundary perturbations in 2 and 3 dimensions. We consider each finite packing with periodic-boundary conditions as the basis of an infinite square or cubic lattice and study properties of vibrational modes at arbitrary wave vector. We find that the stability of such modes can be understood in terms of a competition between plane waves and the anomalous vibrational modes associated with the jamming transition; infinitesimal boundary perturbations become irrelevant for systems that are larger than a length scale that characterizes the transverse excitations. This previously identified length diverges at the jamming transition. article_number: '11000' article_processing_charge: No article_type: original author: - first_name: Samuel S. full_name: Schoenholz, Samuel S. last_name: Schoenholz - first_name: Carl Peter full_name: Goodrich, Carl Peter id: EB352CD2-F68A-11E9-89C5-A432E6697425 last_name: Goodrich orcid: 0000-0002-1307-5074 - first_name: Oleg full_name: Kogan, Oleg last_name: Kogan - first_name: Andrea J. full_name: Liu, Andrea J. last_name: Liu - first_name: Sidney R. full_name: Nagel, Sidney R. last_name: Nagel citation: ama: 'Schoenholz SS, Goodrich CP, Kogan O, Liu AJ, Nagel SR. Stability of jammed packings II: The transverse length scale. Soft Matter. 2013;9(46). doi:10.1039/c3sm51096d' apa: 'Schoenholz, S. S., Goodrich, C. P., Kogan, O., Liu, A. J., & Nagel, S. R. (2013). Stability of jammed packings II: The transverse length scale. Soft Matter. Royal Society of Chemistry. https://doi.org/10.1039/c3sm51096d' chicago: 'Schoenholz, Samuel S., Carl Peter Goodrich, Oleg Kogan, Andrea J. Liu, and Sidney R. Nagel. “Stability of Jammed Packings II: The Transverse Length Scale.” Soft Matter. Royal Society of Chemistry, 2013. https://doi.org/10.1039/c3sm51096d.' ieee: 'S. S. Schoenholz, C. P. Goodrich, O. Kogan, A. J. Liu, and S. R. Nagel, “Stability of jammed packings II: The transverse length scale,” Soft Matter, vol. 9, no. 46. Royal Society of Chemistry, 2013.' ista: 'Schoenholz SS, Goodrich CP, Kogan O, Liu AJ, Nagel SR. 2013. Stability of jammed packings II: The transverse length scale. Soft Matter. 9(46), 11000.' mla: 'Schoenholz, Samuel S., et al. “Stability of Jammed Packings II: The Transverse Length Scale.” Soft Matter, vol. 9, no. 46, 11000, Royal Society of Chemistry, 2013, doi:10.1039/c3sm51096d.' short: S.S. Schoenholz, C.P. Goodrich, O. Kogan, A.J. Liu, S.R. Nagel, Soft Matter 9 (2013). date_created: 2020-04-30T11:43:58Z date_published: 2013-10-08T00:00:00Z date_updated: 2021-01-12T08:15:27Z day: '08' doi: 10.1039/c3sm51096d extern: '1' intvolume: ' 9' issue: '46' language: - iso: eng month: '10' oa_version: None publication: Soft Matter publication_identifier: issn: - 1744-683X - 1744-6848 publication_status: published publisher: Royal Society of Chemistry quality_controlled: '1' status: public title: 'Stability of jammed packings II: The transverse length scale' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9 year: '2013' ... --- _id: '7774' abstract: - lang: eng text: In 2005, Wyart et al. [Europhys. Lett., 2005, 72, 486] showed that the low frequency vibrational properties of jammed amorphous sphere packings can be understood in terms of a length scale, called l*, that diverges as the system becomes marginally unstable. Despite the tremendous success of this theory, it has been difficult to connect the counting argument that defines l* to other length scales that diverge near the jamming transition. We present an alternate derivation of l* based on the onset of rigidity. This phenomenological approach reveals the physical mechanism underlying the length scale and is relevant to a range of systems for which the original argument breaks down. It also allows us to present the first direct numerical measurement of l*. article_number: '10993' article_processing_charge: No article_type: original author: - first_name: Carl Peter full_name: Goodrich, Carl Peter id: EB352CD2-F68A-11E9-89C5-A432E6697425 last_name: Goodrich orcid: 0000-0002-1307-5074 - first_name: Wouter G. full_name: Ellenbroek, Wouter G. last_name: Ellenbroek - first_name: Andrea J. full_name: Liu, Andrea J. last_name: Liu citation: ama: 'Goodrich CP, Ellenbroek WG, Liu AJ. Stability of jammed packings I: The rigidity length scale. Soft Matter. 2013;9(46). doi:10.1039/c3sm51095f' apa: 'Goodrich, C. P., Ellenbroek, W. G., & Liu, A. J. (2013). Stability of jammed packings I: The rigidity length scale. Soft Matter. Royal Society of Chemistry. https://doi.org/10.1039/c3sm51095f' chicago: 'Goodrich, Carl Peter, Wouter G. Ellenbroek, and Andrea J. Liu. “Stability of Jammed Packings I: The Rigidity Length Scale.” Soft Matter. Royal Society of Chemistry, 2013. https://doi.org/10.1039/c3sm51095f.' ieee: 'C. P. Goodrich, W. G. Ellenbroek, and A. J. Liu, “Stability of jammed packings I: The rigidity length scale,” Soft Matter, vol. 9, no. 46. Royal Society of Chemistry, 2013.' ista: 'Goodrich CP, Ellenbroek WG, Liu AJ. 2013. Stability of jammed packings I: The rigidity length scale. Soft Matter. 9(46), 10993.' mla: 'Goodrich, Carl Peter, et al. “Stability of Jammed Packings I: The Rigidity Length Scale.” Soft Matter, vol. 9, no. 46, 10993, Royal Society of Chemistry, 2013, doi:10.1039/c3sm51095f.' short: C.P. Goodrich, W.G. Ellenbroek, A.J. Liu, Soft Matter 9 (2013). date_created: 2020-04-30T11:43:42Z date_published: 2013-10-08T00:00:00Z date_updated: 2021-01-12T08:15:27Z day: '08' doi: 10.1039/c3sm51095f extern: '1' intvolume: ' 9' issue: '46' language: - iso: eng month: '10' oa_version: None publication: Soft Matter publication_identifier: issn: - 1744-683X - 1744-6848 publication_status: published publisher: Royal Society of Chemistry quality_controlled: '1' status: public title: 'Stability of jammed packings I: The rigidity length scale' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 9 year: '2013' ... --- _id: '8030' abstract: - lang: eng text: While the plasticity of excitatory synaptic connections in the brain has been widely studied, the plasticity of inhibitory connections is much less understood. Here, we present recent experimental and theoretical findings concerning the rules of spike timing-dependent inhibitory plasticity and their putative network function. This is a summary of a workshop at the COSYNE conference 2012. article_number: '119' article_processing_charge: No article_type: original author: - first_name: Tim P full_name: Vogels, Tim P id: CB6FF8D2-008F-11EA-8E08-2637E6697425 last_name: Vogels orcid: 0000-0003-3295-6181 - first_name: R. C. full_name: Froemke, R. C. last_name: Froemke - first_name: N. full_name: Doyon, N. last_name: Doyon - first_name: M. full_name: Gilson, M. last_name: Gilson - first_name: J. S. full_name: Haas, J. S. last_name: Haas - first_name: R. full_name: Liu, R. last_name: Liu - first_name: A. full_name: Maffei, A. last_name: Maffei - first_name: P. full_name: Miller, P. last_name: Miller - first_name: C. J. full_name: Wierenga, C. J. last_name: Wierenga - first_name: M. A. full_name: Woodin, M. A. last_name: Woodin - first_name: F. full_name: Zenke, F. last_name: Zenke - first_name: H. full_name: Sprekeler, H. last_name: Sprekeler citation: ama: 'Vogels TP, Froemke RC, Doyon N, et al. Inhibitory synaptic plasticity: Spike timing-dependence and putative network function. Frontiers in Neural Circuits. 2013;7. doi:10.3389/fncir.2013.00119' apa: 'Vogels, T. P., Froemke, R. C., Doyon, N., Gilson, M., Haas, J. S., Liu, R., … Sprekeler, H. (2013). Inhibitory synaptic plasticity: Spike timing-dependence and putative network function. Frontiers in Neural Circuits. Frontiers Media. https://doi.org/10.3389/fncir.2013.00119' chicago: 'Vogels, Tim P, R. C. Froemke, N. Doyon, M. Gilson, J. S. Haas, R. Liu, A. Maffei, et al. “Inhibitory Synaptic Plasticity: Spike Timing-Dependence and Putative Network Function.” Frontiers in Neural Circuits. Frontiers Media, 2013. https://doi.org/10.3389/fncir.2013.00119.' ieee: 'T. P. Vogels et al., “Inhibitory synaptic plasticity: Spike timing-dependence and putative network function,” Frontiers in Neural Circuits, vol. 7. Frontiers Media, 2013.' ista: 'Vogels TP, Froemke RC, Doyon N, Gilson M, Haas JS, Liu R, Maffei A, Miller P, Wierenga CJ, Woodin MA, Zenke F, Sprekeler H. 2013. Inhibitory synaptic plasticity: Spike timing-dependence and putative network function. Frontiers in Neural Circuits. 7, 119.' mla: 'Vogels, Tim P., et al. “Inhibitory Synaptic Plasticity: Spike Timing-Dependence and Putative Network Function.” Frontiers in Neural Circuits, vol. 7, 119, Frontiers Media, 2013, doi:10.3389/fncir.2013.00119.' short: T.P. Vogels, R.C. Froemke, N. Doyon, M. Gilson, J.S. Haas, R. Liu, A. Maffei, P. Miller, C.J. Wierenga, M.A. Woodin, F. Zenke, H. Sprekeler, Frontiers in Neural Circuits 7 (2013). date_created: 2020-06-25T13:23:50Z date_published: 2013-07-18T00:00:00Z date_updated: 2021-01-12T08:16:38Z day: '18' ddc: - '570' doi: 10.3389/fncir.2013.00119 extern: '1' external_id: pmid: - '23882186' file: - access_level: open_access checksum: 9c321cb12977d84048712eefa7f0c497 content_type: application/pdf creator: cziletti date_created: 2020-07-16T11:23:40Z date_updated: 2020-07-16T11:23:40Z file_id: '8123' file_name: 2013_FrontNeurCirc_Vogels.pdf file_size: 1530469 relation: main_file success: 1 file_date_updated: 2020-07-16T11:23:40Z has_accepted_license: '1' intvolume: ' 7' language: - iso: eng license: https://creativecommons.org/licenses/by/3.0/ month: '07' oa: 1 oa_version: Published Version pmid: 1 publication: Frontiers in Neural Circuits publication_identifier: eissn: - 1662-5110 publication_status: published publisher: Frontiers Media quality_controlled: '1' status: public title: 'Inhibitory synaptic plasticity: Spike timing-dependence and putative network function' tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/3.0/legalcode name: Creative Commons Attribution 3.0 Unported (CC BY 3.0) short: CC BY (3.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 7 year: '2013' ... --- _id: '811' abstract: - lang: eng text: Cell migration is commonly accompanied by protrusion of membrane ruffles and lamellipodia. In two-dimensional migration, protrusion of these thin sheets of cytoplasm is considered relevant to both exploration of new space and initiation of nascent adhesion to the substratum. Lamellipodium formation can be potently stimulated by Rho GTPases of the Rac subfamily, but alsoby RhoG or Cdc42. Here we describe viable fibroblast cell lines geneticallydeficient for Rac1 that lack detectable levels of Rac2 and Rac3. Rac-deficient cells were devoid of apparent lamellipodia, but these structures were restored by expression of either Rac subfamily member, but not by Cdc42 or RhoG. Cells deficient in Rac showed strong reduction in wound closure and random cell migration and a notable loss of sensitivity to a chemotactic gradient. Despite these defects, Rac-deficient cells were able to spread, formed filopodia and established focal adhesions. Spreading in these cells was achieved by the extension of filopodia followed by the advancement of cytoplasmic veils between them. The number and size of focal adhesions as well as their intensity were largely unaffected by genetic removal of Rac1. However, Rac deficiency increased the mobility of different components in focal adhesions, potentially explaining how Rac - although not essential - can contribute to focal adhesion assembly. Together, our data demonstrate that Rac signaling is essential for lamellipodium protrusion and for efficient cell migration, but not for spreading or filopodium formation. Our findings also suggest that Rac GTPases are crucial to the establishment or maintenance of polarity in chemotactic migration. acknowledgement: |- This work was supported in part by the Deutsche Forschungsgemeinschaft [grants within programs SFB621 to K.R., and FOR629 and SFB629 to T.E.B.S.]. Deposited in PMC for immediate release. We thank Brigitte Denker and Gerd Landsberg for excellent technical assistance. We are grateful to Robert Geffers (HZI Braunschweig, Germany) for microarray analyses and to Mirko Himmel (UKE Hamburg, Germany) for valuable advice on FRAP analysis. author: - first_name: Anika full_name: Steffen, Anika last_name: Steffen - first_name: Markus full_name: Ladwein, Markus last_name: Ladwein - first_name: Georgi A full_name: Georgi Dimchev id: 38C393BE-F248-11E8-B48F-1D18A9856A87 last_name: Dimchev - first_name: Anke full_name: Hein, Anke last_name: Hein - first_name: Lisa full_name: Schwenkmezger, Lisa last_name: Schwenkmezger - first_name: Stefan full_name: Arens, Stefan last_name: Arens - first_name: Kathrin full_name: Ladwein, Kathrin I last_name: Ladwein - first_name: J. full_name: Holleboom, J. Margit last_name: Holleboom - first_name: Florian full_name: Florian Schur id: 48AD8942-F248-11E8-B48F-1D18A9856A87 last_name: Schur orcid: 0000-0003-4790-8078 - first_name: John full_name: Small, John V last_name: Small - first_name: Janett full_name: Schwarz, Janett last_name: Schwarz - first_name: Ralf full_name: Gerhard, Ralf last_name: Gerhard - first_name: Jan full_name: Faix, Jan last_name: Faix - first_name: Theresia full_name: Stradal, Theresia E last_name: Stradal - first_name: Cord full_name: Brakebusch, Cord H last_name: Brakebusch - first_name: Klemens full_name: Rottner, Klemens last_name: Rottner citation: ama: Steffen A, Ladwein M, Dimchev GA, et al. Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation. Journal of Cell Science. 2013;126(20):4572-4588. doi:10.1242/jcs.118232 apa: Steffen, A., Ladwein, M., Dimchev, G. A., Hein, A., Schwenkmezger, L., Arens, S., … Rottner, K. (2013). Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation. Journal of Cell Science. Company of Biologists. https://doi.org/10.1242/jcs.118232 chicago: Steffen, Anika, Markus Ladwein, Georgi A Dimchev, Anke Hein, Lisa Schwenkmezger, Stefan Arens, Kathrin Ladwein, et al. “Rac Function Is Crucial for Cell Migration but Is Not Required for Spreading and Focal Adhesion Formation.” Journal of Cell Science. Company of Biologists, 2013. https://doi.org/10.1242/jcs.118232. ieee: A. Steffen et al., “Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation,” Journal of Cell Science, vol. 126, no. 20. Company of Biologists, pp. 4572–4588, 2013. ista: Steffen A, Ladwein M, Dimchev GA, Hein A, Schwenkmezger L, Arens S, Ladwein K, Holleboom J, Schur FK, Small J, Schwarz J, Gerhard R, Faix J, Stradal T, Brakebusch C, Rottner K. 2013. Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation. Journal of Cell Science. 126(20), 4572–4588. mla: Steffen, Anika, et al. “Rac Function Is Crucial for Cell Migration but Is Not Required for Spreading and Focal Adhesion Formation.” Journal of Cell Science, vol. 126, no. 20, Company of Biologists, 2013, pp. 4572–88, doi:10.1242/jcs.118232. short: A. Steffen, M. Ladwein, G.A. Dimchev, A. Hein, L. Schwenkmezger, S. Arens, K. Ladwein, J. Holleboom, F.K. Schur, J. Small, J. Schwarz, R. Gerhard, J. Faix, T. Stradal, C. Brakebusch, K. Rottner, Journal of Cell Science 126 (2013) 4572–4588. date_created: 2018-12-11T11:48:38Z date_published: 2013-01-01T00:00:00Z date_updated: 2021-01-12T08:16:57Z day: '01' doi: 10.1242/jcs.118232 extern: 1 intvolume: ' 126' issue: '20' license: https://creativecommons.org/licenses/by/4.0/ month: '01' page: 4572 - 4588 publication: Journal of Cell Science publication_status: published publisher: Company of Biologists publist_id: '6840' quality_controlled: 0 status: public title: Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article volume: 126 year: '2013' ... --- _id: '812' abstract: - lang: eng text: Lamellipodia are sheet-like protrusions formed during migration or phagocytosis and comprise a network of actin filaments. Filament formation in this network is initiated by nucleation/branching through the actin-related protein 2/3 (Arp2/3) complex downstream of its activator, suppressor of cAMP receptor/WASP-family verprolin homologous (Scar/WAVE), but the relative relevance of Arp2/3-mediated branching versus actin filament elongation is unknown. Here we use instantaneous interference with Arp2/3 complex function in live fibroblasts with established lamellipodia. This allows direct examination of both the fate of elongating filaments upon instantaneous suppression of Arp2/3 complex activity and the consequences of this treatment on the dynamics of other lamellipodial regulators. We show that Arp2/3 complex is an essential organizer of treadmilling actin filament arrays but has little effect on the net rate of actin filament turnover at the cell periphery. In addition, Arp2/3 complex serves as key upstream factor for the recruitment of modulators of lamellipodia formation such as capping protein or cofilin. Arp2/3 complex is thus decisive for filament organization and geometry within the network not only by generating branches and novel filament ends, but also by directing capping or severing activities to the lamellipodium. Arp2/3 complex is also crucial to lamellipodia-based migration of keratocytes. acknowledgement: "This work was supported in part by Deutsche Forschungsgemeinschaft Grants RO2414/3-1 (to K.R.) and FA330/6-1 (to J.F.), Austrian \nScience Fund Projects FWF 1516-B09 and FWF P21292-B09 (to J.V.S.), the Vienna Science and Technology \ Fund (WWTF, to \nJ.V.S. and C.S.), and Australian National Health and \ Medical \nResearch Council Grant APP1004175 (to P.W.G.). We thank J. Adams, \nR. Chisholm, A. Hall, L. Machesky, H. G. Mannherz, D. Schafer, and \nR. Wedlich-Söldner \ for expression constructs and B. Denker, \nP. Hagendorff, and G. Landsberg for technical assistance." author: - first_name: Stefan full_name: Koestler, Stefan A last_name: Koestler - first_name: Anika full_name: Steffen, Anika last_name: Steffen - first_name: Maria full_name: Maria Nemethova id: 34E27F1C-F248-11E8-B48F-1D18A9856A87 last_name: Nemethova - first_name: Moritz full_name: Winterhoff, Moritz last_name: Winterhoff - first_name: Ningning full_name: Luo, Ningning last_name: Luo - first_name: J. full_name: Holleboom, J. Margit last_name: Holleboom - first_name: Jessica full_name: Krupp, Jessica last_name: Krupp - first_name: Sonja full_name: Jacob, Sonja last_name: Jacob - first_name: Marlene full_name: Vinzenz, Marlene last_name: Vinzenz - first_name: Florian full_name: Florian Schur id: 48AD8942-F248-11E8-B48F-1D18A9856A87 last_name: Schur orcid: 0000-0003-4790-8078 - first_name: Kai full_name: Schlüter, Kai last_name: Schlüter - first_name: Peter full_name: Gunning, Peter W last_name: Gunning - first_name: Christoph full_name: Winkler, Christoph last_name: Winkler - first_name: Christian full_name: Schmeiser, Christian last_name: Schmeiser - first_name: Jan full_name: Faix, Jan last_name: Faix - first_name: Theresia full_name: Stradal, Theresia E last_name: Stradal - first_name: John full_name: Small, John V last_name: Small - first_name: Klemens full_name: Rottner, Klemens last_name: Rottner citation: ama: Koestler S, Steffen A, Nemethova M, et al. Arp2/3 complex is essential for actin network treadmilling as well as for targeting of capping protein and cofilin. Molecular Biology of the Cell. 2013;24(18):2861-2875. doi:10.1091/mbc.E12-12-0857 apa: Koestler, S., Steffen, A., Nemethova, M., Winterhoff, M., Luo, N., Holleboom, J., … Rottner, K. (2013). Arp2/3 complex is essential for actin network treadmilling as well as for targeting of capping protein and cofilin. Molecular Biology of the Cell. American Society for Biology. https://doi.org/10.1091/mbc.E12-12-0857 chicago: Koestler, Stefan, Anika Steffen, Maria Nemethova, Moritz Winterhoff, Ningning Luo, J. Holleboom, Jessica Krupp, et al. “Arp2/3 Complex Is Essential for Actin Network Treadmilling as Well as for Targeting of Capping Protein and Cofilin.” Molecular Biology of the Cell. American Society for Biology, 2013. https://doi.org/10.1091/mbc.E12-12-0857. ieee: S. Koestler et al., “Arp2/3 complex is essential for actin network treadmilling as well as for targeting of capping protein and cofilin,” Molecular Biology of the Cell, vol. 24, no. 18. American Society for Biology, pp. 2861–2875, 2013. ista: Koestler S, Steffen A, Nemethova M, Winterhoff M, Luo N, Holleboom J, Krupp J, Jacob S, Vinzenz M, Schur FK, Schlüter K, Gunning P, Winkler C, Schmeiser C, Faix J, Stradal T, Small J, Rottner K. 2013. Arp2/3 complex is essential for actin network treadmilling as well as for targeting of capping protein and cofilin. Molecular Biology of the Cell. 24(18), 2861–2875. mla: Koestler, Stefan, et al. “Arp2/3 Complex Is Essential for Actin Network Treadmilling as Well as for Targeting of Capping Protein and Cofilin.” Molecular Biology of the Cell, vol. 24, no. 18, American Society for Biology, 2013, pp. 2861–75, doi:10.1091/mbc.E12-12-0857. short: S. Koestler, A. Steffen, M. Nemethova, M. Winterhoff, N. Luo, J. Holleboom, J. Krupp, S. Jacob, M. Vinzenz, F.K. Schur, K. Schlüter, P. Gunning, C. Winkler, C. Schmeiser, J. Faix, T. Stradal, J. Small, K. Rottner, Molecular Biology of the Cell 24 (2013) 2861–2875. date_created: 2018-12-11T11:48:38Z date_published: 2013-09-15T00:00:00Z date_updated: 2021-01-12T08:17:00Z day: '15' doi: 10.1091/mbc.E12-12-0857 extern: 1 intvolume: ' 24' issue: '18' month: '09' page: 2861 - 2875 publication: Molecular Biology of the Cell publication_status: published publisher: American Society for Biology publist_id: '6841' quality_controlled: 0 status: public title: Arp2/3 complex is essential for actin network treadmilling as well as for targeting of capping protein and cofilin type: journal_article volume: 24 year: '2013' ...