Littérature scientifique sur le sujet « Transport and localization »

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Articles de revues sur le sujet "Transport and localization":

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Malakar, Bidhan, et Binoy Krishna Roy. « TRAIN LOCALIZATION USING AN ADAPTIVE MULTISENSOR DATA FUSION TECHNIQUE ». Transport 34, no 4 (16 octobre 2019) : 508–16. http://dx.doi.org/10.3846/transport.2019.11313.

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This work deals with the development of an adaptive multisensor data fusion technique for the accurate estimation of the trains position and velocity. The proposed technique will work with the Train Collision Avoidance System (TCAS) used in Indian railways during Global Positioning System (GPS) outages. The determination of accurate position of trains is a challenging task for the TCAS during GPS outages. The accuracy of the proposed Volterra Recursive Least Square (VRLS) based adaptive multisensor data fusion technique is evaluated by generating two kinematic profiles for a passenger train running between Silchar–Lumding broad gauge route in Indian railways. The effect of accelerometer bias is also considered during the analysis. It is observed that the developed technique can provide a better estimate of the position and velocity for the TCAS especially during GPS outages and without using any additional railway infrastructure. The simulation results indicate that the proposed technique is superior to the earlier works in terms of achieving better positional accuracy in presence of accelerometer bias.
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Suter, Beat. « RNA localization and transport ». Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms 1861, no 10 (octobre 2018) : 938–51. http://dx.doi.org/10.1016/j.bbagrm.2018.08.004.

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Gottlieb, E. « Messenger RNA transport and localization ». Current Opinion in Cell Biology 2, no 6 (décembre 1990) : 1080–86. http://dx.doi.org/10.1016/0955-0674(90)90159-c.

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Srivastava, Saurabh, Hiori Kino, Shu Nakaharai, Elisseos Verveniotis, Yuji Okawa, Shinichi Ogawa, Christian Joachim et Masakazu Aono. « Quantum transport localization through graphene ». Nanotechnology 28, no 3 (9 décembre 2016) : 035703. http://dx.doi.org/10.1088/1361-6528/28/3/035703.

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Mische, Sarah, Mingang Li, Madeline Serr et Thomas S. Hays. « Direct Observation of Regulated Ribonucleoprotein Transport Across the Nurse Cell/Oocyte Boundary ». Molecular Biology of the Cell 18, no 6 (juin 2007) : 2254–63. http://dx.doi.org/10.1091/mbc.e06-10-0959.

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In Drosophila, the asymmetric localization of specific mRNAs to discrete regions within the developing oocyte determines the embryonic axes. The microtubule motors dynein and kinesin are required for the proper localization of the determinant ribonucleoprotein (RNP) complexes, but the mechanisms that account for RNP transport to and within the oocyte are not well understood. In this work, we focus on the transport of RNA complexes containing bicoid (bcd), an anterior determinant. We show in live egg chambers that, within the nurse cell compartment, dynein actively transports green fluorescent protein-tagged Exuperantia, a cofactor required for bcd RNP localization. Surprisingly, the loss of kinesin I activity elevates RNP motility in nurse cells, whereas disruption of dynein activity inhibits RNP transport. Once RNPs are transferred through the ring canal to the oocyte, they no longer display rapid, linear movements, but they are distributed by cytoplasmic streaming and gradually disassemble. By contrast, bcd mRNA injected into oocytes assembles de novo into RNP particles that exhibit rapid, dynein-dependent transport. We speculate that after delivery to the oocyte, RNP complexes may disassemble and be remodeled with appropriate accessory factors to ensure proper localization.
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Jansen, Ralf-Peter, et Michael Kiebler. « Intracellular RNA sorting, transport and localization ». Nature Structural & ; Molecular Biology 12, no 10 (octobre 2005) : 826–29. http://dx.doi.org/10.1038/nsmb1005-826.

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Chartrand, Pascal, Robert H. Singer et Roy M. Long. « RNP Localization and Transport in Yeast ». Annual Review of Cell and Developmental Biology 17, no 1 (novembre 2001) : 297–310. http://dx.doi.org/10.1146/annurev.cellbio.17.1.297.

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Binenbaum, Jenia, Roy Weinstain et Eilon Shani. « Gibberellin Localization and Transport in Plants ». Trends in Plant Science 23, no 5 (mai 2018) : 410–21. http://dx.doi.org/10.1016/j.tplants.2018.02.005.

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Cao, G., V. Dobrosavljevic, S. McCall, J. E. Crow et R. P. Guertin. « Localization and transport in pseudoternary ruthenates ». Physica B : Condensed Matter 259-261 (janvier 1999) : 951–53. http://dx.doi.org/10.1016/s0921-4526(98)00891-6.

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Ponomarev, A. I., N. A. Babushkina, L. M. Belova, A. N. Ignatenkov, G. I. Harus, N. K. Lerinman, L. D. Sabirzyanova et N. G. Shelushinina. « Transport and localization in Nd1.82Ce0.18CuO4? ? film ». Journal of Low Temperature Physics 105, no 3-4 (novembre 1996) : 939–43. http://dx.doi.org/10.1007/bf00768503.

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Thèses sur le sujet "Transport and localization":

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Kuzovkov, Vladimir, et Niessen Wolfgang von. « Anderson localization and generalized diffusion ». Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-195390.

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Kuzovkov, Vladimir, et Niessen Wolfgang von. « Anderson localization and generalized diffusion ». Diffusion fundamentals 2 (2005) 26, S. 1-2, 2005. https://ul.qucosa.de/id/qucosa%3A14355.

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Fung, Alex Weng Pui. « Localization transport in granular and nanoporous carbon systems ». Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/34088.

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Bjorgaard, Josiah August. « Exciton Diffusion, Transport, and Localization in Conjugated Polymers ». Diss., North Dakota State University, 2013. https://hdl.handle.net/10365/27196.

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Conjugated polymers are wide bandgap semiconductors which have a series of conjugated π-orbitals that extend along the polymer ‘backbone’. The π-orbital conjugation can be disrupted by twisting of the polymer, affecting their optical properties. These materials are very useful for devices, where they are frequently found in semicrystalline thin films. In thin films, Frenkel excitons diffuse on a nanometer scale. However, measurement of the diffusion length of excitons in conjugated polymer films is currently very difficult. Disordered packing and twisting of polymers plays a significant role, but has not been examined in detail. This dissertation presents methods of measuring exciton diffusion length in polymer films and nanoparticles and explains the effect of nuclear disorder on the optical spectra and exciton diffusion in semicrystalline polymer films.
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Kurzidim, Jan, Daniele Coslovich et Gerhard Kahl. « Localization and glass formation of fluids confined in porous matrices ». Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-191691.

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Real, Elgueda Bastián Maximiliano. « Transport and driven-dissipative localization in exciton-polariton lattices ». Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR025.

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La simulation des Hamiltoniens de réseaux dans les plateformes photoniques a permis de mieux comprendre les nouvelles propriétés de transport et de localisation dans le contexte de la physique de l'état solide. En particulier, les exciton-polaritons constituent un système polyvalent permettant d'étudier ces propriétés dans des réseaux avec des structures de bande intrigantes en présence de pertes et de gains, et d'interactions entre particules. Les polaritons sont des quasi-particules hybrides lumière-matière résultant du couplage fort entre les photons et les excitons dans les microcavités semi-conductrices, dont les propriétés peuvent être directement accessibles dans les expériences de photoluminescence. Dans cette thèse, nous étudions premièrement les caractéristiques des réseaux en nid d'abeille déformés, composés de résonateurs de polaritons couplés, à haut contenu photonique. Dans un réseau déformé de façon critique, nous mettons en évidence à la fois un transport semi-Dirac et une localisation anisotrope des photons. Deuxièmement, nous montrons qu'un forçage judicieux dans des réseaux de résonateurs à pertes permet l'apparition de nouveaux modes localisés. En utilisant des réseaux de polaritons sous un forçage résonant par plusieurs faisceaux optiques, nous démontrons la possibilité de localiser la lumière sur différentes géométries, voir jusqu'à un seul site. Enfin, nous profitons de l'interaction de polaritons dépendant de la polarisation pour démontrer un effet optique de type Zeeman dans un seul micropilier. En combinant le couplage spin-orbite optique, inhérent aux microstructures semi-conductrices, avec l'effet Zeeman, induit par l'interaction, nous montrons l'émission de faisceaux de vortex avec une chiralité bien définie. Cette thèse met en lumière la puissance des plateformes de polaritons pour étudier les Hamiltoniens de réseaux avec des propriétés sans précédent. Elle apporte également un premier pas vers la génération, entièrement optique, de phases topologiques dans les réseaux
The simulation of lattice Hamiltonians in photonic platforms has been enlightening in the understanding of novel transport and localization properties in the context of solid-state physics. In particular, exciton-polaritons provide a versatile system to investigate these properties in lattices with intriguing band structures in the presence of gain and loss, and particle interactions. Polaritons are hybrid light-matter quasiparticles arising from the strong coupling between photons and excitons in semiconductor microcavities, whose properties can be directly accessed in photoluminescence experiments. In this thesis, we firstly study the features of strained honeycomb lattices made of coupled polariton resonators having high photonic content. In a critically strained lattice, we evidence both a semi-Dirac transport and an anisotropic localization of photons. Secondly, we show that a judicious driving in lattices of lossy resonators allows the appearance of novel localized modes. Using polariton lattices driven resonantly with several optical beams, we demonstrate the localization of light in at-will geometries down to a single site. Finally, we take advantage of the polarization-dependent polariton interaction to demonstrate an optical Zeeman-like effect in a single micropillar. In combination with optical spin-orbit coupling inherent to semiconductor microstructures, the interaction-induced Zeeman effect results in emission of vortex beams with a well-defined chirality. This thesis brings to light the power of polariton platforms to study lattice Hamiltonians with unprecedented properties and it also provides a first step towards the fully-optical generation of topological phases in lattices
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Gómez, Rivas Jaime. « Light in strongly scattering semiconductors diffuse transport and Anderson localization / ». [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/63879.

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Coslovich, Daniele, Dieter Schwanzer et Gerhard Kahl. « Diffusion-localization and liquid-glass transitions of a colloidal fluid in porous confinement ». Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-190390.

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Kurzidim, Jan, Daniele Coslovich et Gerhard Kahl. « Localization and glass formation of fluids confined in porous matrices ». Diffusion fundamentals 11 (2009) 105, S. 1-2, 2009. https://ul.qucosa.de/id/qucosa%3A14079.

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Chitale, Chaitanya S. « Spatial Characterization of Protein Localization Patterns ». The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1282088474.

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Livres sur le sujet "Transport and localization":

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Kramer, Bernhard, Gerd Bergmann et Yvan Bruynseraede, dir. Localization, Interaction, and Transport Phenomena. Berlin, Heidelberg : Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-82516-3.

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M, Soukoulis C., North Atlantic Treaty Organization. Scientific Affairs Division. et NATO Advanced Research Workshop on Localization and Propagation of Classical Waves in Random and Periodic Structures (1992 : Hagia Pelagia, Greece), dir. Photonic band gaps and localization. New York : Plenum Press, 1993.

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Silin̦š, E. Organic molecular crystals : Interaction, localization, and transport phenomena. New York : American Institute of Physics, 1994.

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Siliņš, E. Organic molecular crystals : Interaction,localization, and transport phenomena. New York : American Institute of Physics, 1994.

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NATO Advanced Research Workshop on Localization and Propagation of Classical Wavesin Random and Periodic Structures (1992 Aghia Pelaghia, Greece). Photonic band gaps and localization. New York : Plenum Press, 1993.

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Wan, Shibiao. Machine learning for protein subcellular localization prediction. Boston : De Gruyter, 2015.

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1942-, Kramer B., Bergmann G. 1938-, Bruynseraede Y. 1938- et International Conference on Localization, Interaction, and Transport Phenomena in Impure Metals (1984 : Braunschweig, Germany), dir. Localization, interaction, and transport phenomena : Proceedings of the International Conference, August 23-28, 1984, Braunschweig, Fed. Rep. of Germany. Berlin : Springer-Verlag, 1985.

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Kramer, Bernhard. Localization, Interaction, and Transport Phenomena : Proceedings of the International Conference, August 23-28, 1984 Braunschweig, Fed. Rep. of Germany. Berlin, Heidelberg : Springer Berlin Heidelberg, 1985.

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Lopatin, Anatoli, et Colin G. Nichols. Ion Channel Localization. Humana Press, 2010.

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Soukoulis, C. M. Photonic Band Gaps and Localization. Springer London, Limited, 2013.

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Chapitres de livres sur le sujet "Transport and localization":

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Hall, M. N. « Considerations on the Mechanism of Nuclear Protein Localization in Yeast ». Dans Nucleocytoplasmic Transport, 247–52. Berlin, Heidelberg : Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71565-5_20.

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Sassetti, Maura, Alessandro Braggio et Fabio Cavaliere. « Spin Transport Properties of a Quantum Dot ». Dans Anderson Localization and Its Ramifications, 259–73. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-45202-7_18.

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Weinmann, Dietmar. « Spin Blockades in the Transport through Quantum Dots ». Dans Anderson Localization and Its Ramifications, 289–301. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-45202-7_20.

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Tip, A. « A Transport Equation for Random Electromagnetic Wave Propagation ». Dans Photonic Band Gaps and Localization, 459–64. Boston, MA : Springer US, 1993. http://dx.doi.org/10.1007/978-1-4899-1606-8_34.

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Mlynka, Michal, Peter Brida et Juraj Machaj. « Modular Localization System for Intelligent Transport ». Dans Recent Developments in Computational Collective Intelligence, 115–24. Cham : Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-01787-7_11.

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Halperin, B. I., S. Feng et P. N. Sen. « Transport Properties Near the Percolation Threshold of Continuum Systems ». Dans Localization and Metal-Insulator Transitions, 355–66. Boston, MA : Springer US, 1985. http://dx.doi.org/10.1007/978-1-4613-2517-8_29.

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Seiffge, Dirk, Eberhard Kremer, Volker Laux et Peter Reifert. « Investigations Concerning Localization of Induced Thrombus Formation at Arteriolar Branchings ». Dans Biomechanical Transport Processes, 339–46. Boston, MA : Springer US, 1990. http://dx.doi.org/10.1007/978-1-4757-1511-8_36.

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Snarskii, Andrei A., Igor V. Bezsudnov, Vladimir A. Sevryukov, Alexander Morozovskiy et Joseph Malinsky. « Anderson Localization in the Percolation Structure ». Dans Transport Processes in Macroscopically Disordered Media, 275–78. New York, NY : Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4419-8291-9_22.

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Schweitzer, Ludwig. « Frequency Dependent Electrical Transport in the Integer Quantum Hall Effect ». Dans Anderson Localization and Its Ramifications, 65–82. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-45202-7_6.

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Watson, George H., Paul M. Saulnier, İ. İnanç Tarhan et Martin P. Zinkin. « Factors That Influence Photon Transport Measurements in Dense Random Media ». Dans Photonic Band Gaps and Localization, 131–49. Boston, MA : Springer US, 1993. http://dx.doi.org/10.1007/978-1-4899-1606-8_9.

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Actes de conférences sur le sujet "Transport and localization":

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Mafi, Arash. « Image Transport through Anderson Localization ». Dans 2018 IEEE Photonics Society Summer Topical Meeting Series (SUM). IEEE, 2018. http://dx.doi.org/10.1109/phosst.2018.8456738.

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Kessel, David, et Elizabeth Sykes. « Transport, localization, and phototoxicity of m-THPC ». Dans BiOS '99 International Biomedical Optics Symposium, sous la direction de Thomas J. Dougherty. SPIE, 1999. http://dx.doi.org/10.1117/12.351504.

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Hsieh, P., C. Chung, J. F. McMillan, M. Lu, N. C. Panoiu et C. W. Wong. « Photon transport and localization in optical superlattices ». Dans CLEO : QELS_Fundamental Science. Washington, D.C. : OSA, 2014. http://dx.doi.org/10.1364/cleo_qels.2014.fm3c.3.

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Iordache, Valentin, Razvan Andrei Gheroghiu, Valentin Alexandru Stan et Madalina Tarla. « ZigBee localization system for public transport vehicles ». Dans 2019 11th International Conference on Electronics, Computers and Artificial Intelligence (ECAI). IEEE, 2019. http://dx.doi.org/10.1109/ecai46879.2019.9042022.

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Al-Eidani, Osama H., Aseel H. Al-Nakkash et Osama Abbas Hussein. « Evaluation fingerprint localization outdoor KNN SVM ANN using LoRa ». Dans TRANSPORT, ECOLOGY, SUSTAINABLE DEVELOPMENT : EKO VARNA 2023. AIP Publishing, 2024. http://dx.doi.org/10.1063/5.0191553.

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Zhao, Jinyuan, Prakash Ishwar et Janusz Konrad. « Privacy-preserving indoor localization via light transport analysis ». Dans 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 2017. http://dx.doi.org/10.1109/icassp.2017.7952773.

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Real, B., O. Jamadi, M. Milicevic, N. Pernet, P. St-Jean, T. Ozawa, G. Montambaux et al. « Semi-Dirac transport and localization in polaritonic graphene ». Dans 2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). IEEE, 2021. http://dx.doi.org/10.1109/cleo/europe-eqec52157.2021.9542044.

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Verma, Rohit, Aviral Shrivastava, Bivas Mitra, Sujoy Saha, Niloy Ganguly, Subrata Nandi et Sandip Chakraborty. « UrbanEye : An outdoor localization system for public transport ». Dans IEEE INFOCOM 2016 - IEEE Conference on Computer Communications. IEEE, 2016. http://dx.doi.org/10.1109/infocom.2016.7524393.

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Fuhrer, M. S., U. Varadarajan, W. Holmes, P. L. Richards, P. Delaney, S. G. Louie et A. Zettl. « Transport and localization in single-walled carbon nanotubes ». Dans The 12th international winterschool on electronic properties of novel materials : progress in molecular nanostructures. AIP, 1998. http://dx.doi.org/10.1063/1.56501.

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Schwartz, Tal, Guy Bartal, Shmuel Fishman et Mordechai Segev. « Transport and Anderson Localization in 2-Dimensional Photonic Lattices ». Dans Photonic Metamaterials : From Random to Periodic. Washington, D.C. : OSA, 2006. http://dx.doi.org/10.1364/meta.2006.wa6.

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Rapports d'organisations sur le sujet "Transport and localization":

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Spencer, Thomas. Localization and Transport in Random Media. Fort Belvoir, VA : Defense Technical Information Center, février 1993. http://dx.doi.org/10.21236/ada264640.

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Allen, S. J. High Electric Field Quantum Transport : Submillimeter Wave AC Stark Localization in Vertical and Lateral Superlattices. Fort Belvoir, VA : Defense Technical Information Center, mars 1996. http://dx.doi.org/10.21236/ada313811.

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Izhar, Shamay, Maureen Hanson et Nurit Firon. Expression of the Mitochondrial Locus Associated with Cytoplasmic Male Sterility in Petunia. United States Department of Agriculture, février 1996. http://dx.doi.org/10.32747/1996.7604933.bard.

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The main goal of the proposed research was to continue the mutual investigations into the molecular basis of CMS and male fertility restoration [MRF], with the ultimate goal of understanding these phenomena in higher plants. The experiments focused on: (1) dissecting apart the complex CMS - specific mitochondrial S-Pcf locus, in order to distinguish its essential parts which cause sterility from other parts and study its molecular evolution. (2) Studying the expression of the various regions of the S-Pcf locus in fertile and sterile lines and comparing the structure and ultrastructure of sterile and fertile tissues. (3) Determine whether alteration in respiration is genetically associated with CMS. Our mutual investigations further substantiated the association between the S-Pcf locus and CMS by the findings that the fertile phenotype of a population of unstable petunia somatic hybrids which contain the S-Pcf locus, is due to the presence of multiple muclear fertility restoration genes in this group of progenies. The information obtained by our studies indicate that homologous recombination played a major role in the molecular evolution of the S-Pcf locus and the CMS trait and in the generation of mitochondrial mutations in general. Our data suggest that the CMS cytoplasm evolved by introduction of a urs-s containing sublimon into the main mitochondrial genome via homologous recombination. We have also found that the first mutation detected so far in S-Pcf is a consequence of a homologous recombination mechanism involving part of the cox2 coding sequence. In all the cases studied by us, at the molecular level, we found that fusion of two different cells caused mitochondrial DNA recombination followed by sorting out of a specific mtDNA population or sequences. This sequence of events suggested as a mechanism for the generation of novel mitochondrial genomes and the creation of new traits. The present research also provides data concerning the expression of the recombined and complex CMS-specific S-Pcf locus as compared with the expression of additional mitochondrial proteins as well as comparative histological and ultrastructural studies of CMS and fertile Petunia. Evidence is provided for differential localization of mitochondrially encoded proteins in situ at the tissue level. The similar localization patterns of Pcf and atpA may indicate that Pcf product could interfere with the functioning of the mitochondrial ATPase in a tissue undergoing meiosis and microsporogenesis. Studies of respiration in CMS and fertile Petunia lines indicate that they differe in the partitioning of electron transport through the cytochrome oxidase and alternative oxidase pathways. The data indicate that the electron flux through the two oxidase pathways differs between mitochondria from fertile and sterile Petunia lines at certain redox states of the ubiquinone pool. In summary, extensive data concerning the CMS-specific S-Pcf locus of Petunia at the DNA and protein levels as well as information concerning different biochemical activity in CMS as compared to male fertile lines have been accumulated during the three years of this project. In addition, the involvement of the homologous recombination mechanism in the evolution of mt encoded traits is emphasized.
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Alfano, James, Isaac Barash, Thomas Clemente, Paul E. Staswick, Guido Sessa et Shulamit Manulis. Elucidating the Functions of Type III Effectors from Necrogenic and Tumorigenic Bacterial Pathogens. United States Department of Agriculture, janvier 2010. http://dx.doi.org/10.32747/2010.7592638.bard.

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Many phytopathogenic bacteria use a type III protein secretion system (T3SS) to inject type III effectors into plant cells. In the experiments supported by this one-year feasibility study we investigated type III effector function in plants by using two contrasting bacterial pathogens: Pseudomonas syringae pv. tomato, a necrotrophic pathogen and Pantoea agglomerans, a tumorigenic pathogen. The objectives are listed below along with our major conclusions, achievements, and implications for science and agriculture. Objective 1: Compare Pseudomonas syringae and Pantoea agglomerans type III effectors in established assays to test the extent that they can suppress innate immunity and incite tumorigenesis. We tested P. agglomerans type III effectors in several innate immunity suppression assays and in several instances these effectors were capable of suppressing plant immunity, outputs that are suppressed by P. syringae effectors. Interestingly, several P. syringae effectors were able to complement gall production to a P. agglomerans pthGmutant. These results suggest that even though the disease symptoms of these pathogens are dramatically different, their type III effectors may function similarly. Objective 2: Construct P. syringae mutants in different combinations of type III-related DNA clusters to reduce type III effector redundancy. To determine their involvement in pathogenicity we constructed mutants that lack individual and multiple type III-related DNA clusters using a Flprecombinase-mediated mutagenesis strategy. The majority of single effector mutants in DC3000 have weak pathogenicity phenotypes most likely due to functional redundancy of effectors. Supporting this idea, Poly-DNAcluster deletion mutants were more significantly reduced in their ability to cause disease. Because these mutants have less functional redundancy of type III effectors, they should help identify P. syringae and P. agglomerans effectors that contribute more significantly to virulence. Objective 3: Determine the extent that P. syringae and P. agglomerans type III effectors alter hormone levels in plants. Inhibition of auxin polar transport by 2,3,5-triiodobenzoic acid (TIBA) completely prevented gall formation by P. agglomerans pv. gypsophilae in gypsophila cuttings. This result supported the hypothesis that auxin and presumably cytokinins of plant origin, rather than the IAA and cytokinins secreted by the pathogen, are mandatory for gall formation. Transgenic tobacco with pthGshowed various phenotypic traits that suggest manipulation of auxin metabolism. Moreover, the auxin levels in pthGtransgenic tobacco lines was 2-4 times higher than the control plants. External addition of auxin or cytokinins could modify the gall size in gypsophila cuttings inoculated with pthGmutant (PagMx27), but not with other type III effectors. We are currently determining hormone levels in transgenic plants expressing different type III effectors. Objective 4: Determine whether the P. agglomerans effectors HsvG/B act as transcriptional activators in plants. The P. agglomerans type III effectors HsvG and HsvB localize to the nucleus of host and nonhost plants and act as transcription activators in yeast. Three sites of adjacent arginine and lysine in HsvG and HsvB were suspected to act as Nuclear localization signals (NLS) domains. A nuclear import assay indicated two of the three putative NLS domains were functional NLSs in yeast. These were shown to be active in plants by fusing HsvG and HsvB to YFP. localization to the nucleus was dependent on these NLS domains. These achievements indicate that our research plan is feasible and suggest that type III effectors suppress innate immunity and modulate plant hormones. This information has the potential to be exploited to improve disease resistance in agricultural crops.
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Meidan, Rina, et Joy Pate. Roles of Endothelin 1 and Tumor Necrosis Factor-A in Determining Responsiveness of the Bovine Corpus Luteum to Prostaglandin F2a. United States Department of Agriculture, janvier 2004. http://dx.doi.org/10.32747/2004.7695854.bard.

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The corpus luteum (CL) is a transient endocrine gland that has a vital role in the regulation of the estrous cycle, fertility and the maintenance of pregnancy. In the absence of appropriate support, such as occurs during maternal recognition of pregnancy, the CL will regress. Prostaglandin F2a (PGF) was first suggested as the physiological luteolysin in ruminants several decades ago. Yet, the cellular mechanisms by which PGF causes luteal regression remain poorly defined. In recent years it became evident that the process of luteal regression requires a close cooperation between steroidogenic, endothelial and immune cells, all resident cells of this gland. Changes in the population of these cells within the CL closely consort with the functional changes occurring during various stages of CL life span. The proposal aimed to gain a better understanding of the intra-ovarian regulation of luteolysis and focuses especially on the possible reasons causing the early CL (before day 5) to be refractory to the luteolytic actions of PGF. The specific aims of this proposal were to: determine if the refractoriness of the early CL to PGF is due to its inability to synthesize or respond to endothelin–1 (ET-1), determine the cellular localization of ET, PGF and tumor necrosis factor a (TNF a) receptors in early and mid luteal phases, determine the functional relationships among ET-1 and cytokines, and characterize the effects of PGF and ET-1 on prostaglandin production by luteal cell types. We found that in contrast to the mature CL, administration of PGF2a before day 5 of the bovine cycle failed to elevate ET-1, ETA receptors or to induce luteolysis. In fact, PGF₂ₐ prevented the upregulation of the ET-1 gene by ET-1 or TNFa in cultured luteal cells from day 4 CL. In addition, we reported that ECE-1 expression was elevated during the transitionof the CL from early to mid luteal phase and was accompanied by a significant rise in ET-1 peptide. This coincides with the time point at which the CL gains its responsiveness to PGF2a, suggesting that ability to synthesize ET-1 may be a prerequisite for luteolysis. We have shown that while ET-1 mRNA was exclusively localized to endothelial cells both in young and mature CL, ECE-1 was present in the endothelial cells and steroidogenic cells alike. We also found that the gene for TNF receptor I is only moderately affected by the cytokines tested, but that the gene for TNF receptor II is upregulated by ET-1 and PGF₂ₐ. However, these cytokines both increase expression of MCP-1, although TNFa is even more effective in this regard. In addition, we found that proteins involved in the transport and metabolism of PGF (PGT, PGDH, COX-2) change as the estrous cycle progresses, and could contribute to the refractoriness of young CL. The data obtained in this work illustrate ET-1 synthesis throughout the bovine cycle and provide a better understanding of the mechanisms regulating luteal regression and unravel reasons causing the CL to be refractory to PGF2a.
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Granot, David, Richard Amasino et Avner Silber. Mutual effects of hexose phosphorylation enzymes and phosphorous on plant development. United States Department of Agriculture, janvier 2006. http://dx.doi.org/10.32747/2006.7587223.bard.

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Research objectives 1) Analyze the combined effects of hexose phosphorylation and P level in tomato and Arabidopsis plants 2) Analyze the combined effects of hexose phosphorylation and P level in pho1 and pho2 Arabidopsis mutants 3) Clone and analyze the PHO2 gene 4) Select Arabidopsis mutants resistant to high and low P 5) Analyze the Arabidopsis mutants and clone the corresponding genes 6) Survey wild tomato species for growth characteristics at various P levels Background to the topic Hexose phosphorylating enzymes, the first enzymes of sugar metabolism, regulate key processes in plants such as photosynthesis, growth, senescence and vascular transport. We have previously discovered that hexose phosphorylating enzymes might regulate these processes as a function of phosphorous (P) concentration, and might accelerate acquisition of P, one of the most limiting nutrients in the soil. These discoveries have opened new avenues to gain fundamental knowledge about the relationship between P, sugar phosphorylation and plant development. Since both hexose phosphorylating enzymes and P levels affect plant development, their interaction is of major importance for agriculture. Due to the acceleration of senescence caused by the combined effects of hexose phosphorylation and P concentration, traits affecting P uptake may have been lost in the course of cultivation in which fertilization with relatively high P (30 mg/L) are commonly used. We therefore intended to survey wild tomato species for high P-acquisition at low P soil levels. Genetic resources with high P-acquisition will serve not only to generate a segregating population to map the trait and clone the gene, but will also provide a means to follow the trait in classical breeding programs. This approach could potentially be applicable for other crops as well. Major conclusions, solutions, achievements Our results confirm the mutual effect of hexose phosphorylating enzymes and P level on plant development. Two major aspects of this mutual effect arose. One is related to P toxicity in which HXK seems to play a major role, and the second is related to the effect of HXK on P concentration in the plant. Using tomato plants we demonstrated that high HXK activity increased leaf P concentration, and induced P toxicity when leaf P concentration increases above a certain high level. These results further support our prediction that the desired trait of high-P acquisition might have been lost in the course of cultivation and might exist in wild species. Indeed, in a survey of wild species we identified tomato species that acquired P and performed better at low P (in the irrigation water) compared to the cultivated Lycopersicon esculentum species. The connection between hexose phosphorylation and P toxicity has also been shown with the P sensitive species VerticordiaplumosaL . in which P toxicity is manifested by accelerated senescence (Silber et al., 2003). In a previous work we uncovered the phenomenon of sugar induced cell death (SICD) in yeast cells. Subsequently we showed that SICD is dependent on the rate of hexose phosphorylation as determined by Arabidopsis thaliana hexokinase. In this study we have shown that hexokinase dependent SICD has many characteristics of programmed cell death (PCD) (Granot et al., 2003). High hexokinase activity accelerates senescence (a PCD process) of tomato plants, which is further enhanced by high P. Hence, hexokinase mediated PCD might be a general phenomena. Botrytis cinerea is a non-specific, necrotrophic pathogen that attacks many plant species, including tomato. Senescing leaves are particularly susceptible to B. cinerea infection and delaying leaf senescence might reduce this susceptibility. It has been suggested that B. cinerea’s mode of action may be based on induction of precocious senescence. Using tomato plants developed in the course of the preceding BARD grant (IS 2894-97) and characterized throughout this research (Swartzberg et al., 2006), we have shown that B. cinerea indeed induces senescence and is inhibited by autoregulated production of cytokinin (Swartzberg et al., submitted). To further determine how hexokinase mediates sugar effects we have analyzed tomato plants that express Arabidopsis HXK1 (AtHXK1) grown at different P levels in the irrigation water. We found that Arabidopsis hexokinase mediates sugar signalling in tomato plants independently of hexose phosphate (Kandel-Kfir et al., submitted). To study which hexokinase is involved in sugar sensing we searched and identified two additional HXK genes in tomato plants (Kandel-Kfir et al., 2006). Tomato plants have two different hexose phosphorylating enzymes; hexokinases (HXKs) that can phosphorylate either glucose or fructose, and fructokinases (FRKs) that specifically phosphorylate fructose. To complete the search for genes encoding hexose phosphorylating enzymes we identified a forth fructokinase gene (FRK) (German et al., 2004). The intracellular localization of the four tomato HXK and four FRK enzymes has been determined using GFP fusion analysis in tobacco protoplasts (Kandel-Kfir et al., 2006; Hilla-Weissler et al., 2006). One of the HXK isozymes and one of the FRK isozymes are located within plastids. The other three HXK isozymes are associated with the mitochondria while the other three FRK isozymes are dispersed in the cytosol. We concluded that HXK and FRK are spatially separated in plant cytoplasm and accordingly might play different metabolic and perhaps signalling roles. We have started to analyze the role of the various HXK and FRK genes in plant development. So far we found that LeFRK2 is required for xylem development (German et al., 2003). Irrigation with different P levels had no effect on the phenotype of LeFRK2 antisense plants. In the course of this research we developed a rapid method for the analysis of zygosity in transgenic plants (German et al., 2003).

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