@article{11120, abstract = {The nuclear envelope (NE) is a highly specialized membrane that delineates the eukaryotic cell nucleus. It is composed of the inner and outer nuclear membranes, nuclear pore complexes (NPCs) and, in metazoa, the lamina. The NE not only regulates the trafficking of macromolecules between nucleoplasm and cytosol but also provides anchoring sites for chromatin and the cytoskeleton. Through these interactions, the NE helps position the nucleus within the cell and chromosomes within the nucleus, thereby regulating the expression of certain genes. The NE is not static, rather it is continuously remodeled during cell division. The most dramatic example of NE reorganization occurs during mitosis in metazoa when the NE undergoes a complete cycle of disassembly and reformation. Despite the importance of the NE for eukaryotic cell life, relatively little is known about its biogenesis or many of its functions. We thus are far from understanding the molecular etiology of a diverse group of NE-associated diseases.}, author = {HETZER, Martin W and Walther, Tobias C. and Mattaj, Iain W.}, issn = {1530-8995}, journal = {Annual Review of Cell and Developmental Biology}, keywords = {Cell Biology, Developmental Biology}, pages = {347--380}, publisher = {Annual Reviews}, title = {{Pushing the envelope: Structure, function, and dynamics of the nuclear periphery}}, doi = {10.1146/annurev.cellbio.21.090704.151152}, volume = {21}, year = {2005}, } @inproceedings{11698, abstract = {We give a short survey of the use of hyperlink analysis in web search engine ranking and sketch other applications of hyperlink analysis in the web space.}, author = {Henzinger, Monika H}, booktitle = {Proceedings of the 16th ACM conference on Hypertext and hypermedia}, isbn = {9781595931689}, keywords = {Hyperlink Analysis, World Wide Web}, location = {Salzburg, Austria}, pages = {1--3}, publisher = {Association for Computing Machinery}, title = {{Hyperlink analysis on the world wide web}}, doi = {10.1145/1083356.1083357}, year = {2005}, } @article{11904, abstract = {Many daily activities present information in the form of a stream of text, and often people can benefit from additional information on the topic discussed. TV broadcast news can be treated as one such stream of text; in this paper we discuss finding news articles on the web that are relevant to news currently being broadcast. We evaluated a variety of algorithms for this problem, looking at the impact of inverse document frequency, stemming, compounds, history, and query length on the relevance and coverage of news articles returned in real time during a broadcast. We also evaluated several postprocessing techniques for improving the precision, including reranking using additional terms, reranking by document similarity, and filtering on document similarity. For the best algorithm, 84–91% of the articles found were relevant, with at least 64% of the articles being on the exact topic of the broadcast. In addition, a relevant article was found for at least 70% of the topics.}, author = {Henzinger, Monika H and Chang, Bay-Wei and Milch, Brian and Brin, Sergey}, issn = {1573-1413}, journal = {World Wide Web}, number = {2}, pages = {101--126}, publisher = {Springer Nature}, title = {{Query-free news search}}, doi = {10.1007/s11280-004-4870-6}, volume = {8}, year = {2005}, } @article{11763, abstract = {We present the first polylog-competitive online algorithm for the general multicast admission control and routing problem in the throughput model. The ratio of the number of requests accepted by the optimum offline algorithm to the expected number of requests accepted by our algorithm is O((log n + log log M)(log n + log M) log n), where M is the number of multicast groups and n is the number of nodes in the graph. We show that this is close to optimum by presenting an Ω(log n log M) lower bound on this ratio for any randomized online algorithm against an oblivious adversary, when M is much larger than the link capacities. Our lower bound applies even in the restricted case where the link capacities are much larger than bandwidth requested by a single multicast. We also present a simple proof showing that it is impossible to be competitive against an adaptive online adversary. As in the previous online routing algorithms, our algorithm uses edge-costs when deciding on which is the best path to use. In contrast to the previous competitive algorithms in the throughput model, our cost is not a direct function of the edge load. The new cost definition allows us to decouple the effects of routing and admission decisions of different multicast groups.}, author = {Goel, Ashish and Henzinger, Monika H and Plotkin, Serge}, issn = {0196-6774}, journal = {Journal of Algorithms}, number = {1}, pages = {1--20}, publisher = {Elsevier}, title = {{An online throughput-competitive algorithm for multicast routing and admission control}}, doi = {10.1016/j.jalgor.2004.11.001}, volume = {55}, year = {2005}, } @article{12657, abstract = {An enhanced temperature-index glacier melt model, incorporating incoming shortwave radiation and albedo, is presented. The model is an attempt to combine the high temporal resolution and accuracy of physically based melt models with the lower data requirements and computational simplicity of empirical melt models, represented by the ‘degree-day’ method and its variants. The model is run with both measured and modelled radiation data, to test its applicability to glaciers with differing data availability. Five automatic weather stations were established on Haut Glacier d’Arolla, Switzerland, between May and September 2001. Reference surface melt rates were calculated using a physically based energy-balance melt model. The performance of the enhanced temperature-index model was tested at each of the four validation stations by comparing predicted hourly melt rates with reference melt rates. Predictions made with three other temperature-index models were evaluated in the same way for comparison. The enhanced temperature-index model offers significant improvements over the other temperature-index models, and accounts for 90–95% of the variation in the reference melt rate. The improvement is lower, but still significant, when the model is forced by modelled shortwave radiation data, thus offering a better alternative to existing models that require only temperature data input.}, author = {Pellicciotti, Francesca and Brock, Ben and Strasser, Ulrich and Burlando, Paolo and Funk, Martin and Corripio, Javier}, issn = {1727-5652}, journal = {Journal of Glaciology}, number = {175}, pages = {573--587}, publisher = {Cambridge University Press}, title = {{An enhanced temperature-index glacier melt model including the shortwave radiation balance: Development and testing for Haut Glacier d’Arolla, Switzerland}}, doi = {10.3189/172756505781829124}, volume = {51}, year = {2005}, } @article{1298, abstract = {Genetically encoded fluorescent probes of neural activity represent new promising tools for systems neuroscience. Here, we present a comparative in vivo analysis of 10 different genetically encoded calcium indicators, as well as the pH-sensitive synapto-pHluorin. We analyzed their fluorescence changes in presynaptic boutons of the Drosophila larval neuromuscular junction. Robust neural activity did not result in any or noteworthy fluorescence changes when Flash-Pericam, Camgaroo-1, and Camgaroo-2 were expressed. However, calculated on the raw data, fractional fluorescence changes up to 18% were reported by synapto-pHluorin, Yellow Cameleon 2.0, 2.3, and 3.3, Inverse-Pericam, GCaMP1.3, GCaMP1.6, and the troponin C-based calcium sensor TN-L15. The response characteristics of all of these indicators differed considerably from each other, with GCaMP1.6 reporting high rates of neural activity with the largest and fastest fluorescence changes. However, GCaMP1.6 suffered from photobleaching, whereas the fluorescence signals of the double-chromophore indicators were in general smaller but more photostable and reproducible, with TN-L15 showing the fastest rise of the signals at lower activity rates. We show for GCaMP1.3 and YC3.3 that an expanded range of neural activity evoked fairly linear fluorescence changes and a corresponding linear increase in the signal-to-noise ratio (SNR). The expression level of the indicator biased the signal kinetics and SNR, whereas the signal amplitude was independent. The presented data will be useful for in vivo experiments with respect to the selection of an appropriate indicator, as well as for the correct interpretation of the optical signals.}, author = {Reiff, Dierk F and Ihring, Alexandra and Guerrero, Giovanna and Isacoff, Ehud Y and Maximilian Jösch and Nakai, Junichi and Borst, Alexander}, journal = {Journal of Neuroscience}, number = {19}, pages = {4766 -- 4778}, publisher = {Society for Neuroscience}, title = {{In vivo performance of genetically encoded indicators of neural activity in flies}}, doi = {10.1523/JNEUROSCI.4900-04.2005}, volume = {25}, year = {2005}, } @article{1447, abstract = {Building on a recent paper [8], here we argue that the combinatorics of matroids are intimately related to the geometry and topology of toric hyperkähler varieties. We show that just like toric varieties occupy a central role in Stanley’s proof for the necessity of McMullen’s conjecture (or g-inequalities) about the classification of face vectors of simplicial polytopes, the topology of toric hyperkähler varieties leads to new restrictions on face vectors of matroid complexes. Namely in this paper we will give two proofs that the injectivity part of the Hard Lefschetz theorem survives for toric hyperkähler varieties. We explain how this implies the g-inequalities for rationally representable matroids. We show how the geometrical intuition in the first proof, coupled with results of Chari [3], leads to a proof of the g-inequalities for general matroid complexes, which is a recent result of Swartz [20]. The geometrical idea in the second proof will show that a pure O-sequence should satisfy the g-inequalities, thus showing that our result is in fact a consequence of a long-standing conjecture of Stanley.}, author = {Tamas Hausel}, journal = {Open Mathematics}, number = {1}, pages = {26 -- 38}, publisher = {Central European Science Journals}, title = {{Quaternionic geometry of matroids}}, doi = {10.2478/BF02475653}, volume = {3}, year = {2005}, } @inbook{1444, abstract = {The paper surveys the mirror symmetry conjectures of Hausel-Thaddeus and Hausel-Rodriguez-Villegas concerning the equality of certain Hodge numbers of SL(n, ℂ) vs. PGL(n, ℂ) flat connections and character varieties for curves, respectively. Several new results and conjectures and their relations to works of Hitchin, Gothen, Garsia-Haiman and Earl-Kirwan are explained. These use the representation theory of finite groups of Lie-type via the arithmetic of character varieties and lead to an unexpected conjecture for a Hard Lefschetz theorem for their cohomology.}, author = {Tamas Hausel}, booktitle = {Geometric Methods in Algebra and Number Theory}, pages = {193 -- 217}, publisher = {Springer}, title = {{Mirror symmetry and Langlands duality in the non-Abelian Hodge theory of a curve}}, doi = {10.1007/0-8176-4417-2_9}, volume = {235}, year = {2005}, } @article{1463, abstract = {We study an integration theory in circle equivariant cohomology in order to prove a theorem relating the cohomology ring of a hyperkähler quotient to the cohomology ring of the quotient by a maximal abelian subgroup, analogous to a theorem of Martin for symplectic quotients. We discuss applications of this theorem to quiver varieties, and compute as an example the ordinary and equivariant cohomology rings of a hyperpolygon space.}, author = {Tamas Hausel and Proudfoot, Nicholas J}, journal = {Topology}, number = {1}, pages = {231 -- 248}, publisher = {Elsevier}, title = {{Abelianization for hyperkähler quotients}}, doi = {10.1016/j.top.2004.04.002}, volume = {44}, year = {2005}, } @article{1742, abstract = {The effects of substrate temperature, growth rate, and postgrowth annealing on the composition of Ge islands grown on Si(001) were investigated with a combination of selective wet chemical etching and atomic force microscopy. A simple kinetic model comprising only surface diffusion processes can explain all the experimentally observed compositional profiles for pyramid and dome islands grown in the 560-620°C range. From this model three-dimensional compositional maps were extracted. By performing annealing experiments a change in the composition of the domes was observed. This could be explained as the result of the islands' movement induced by alloying-driven energy minimization. Also in this case kinetically hindered bulk diffusion processes are not needed to explain the experimental observations.}, author = {Georgios Katsaros and Costantini, Giovanni and Stoffel, Mathieu and Esteban, Rubén and Bittner, Alexander M and Rastelli, Armando and Denker, Ulrich and Schmidt, Oliver G and Kern, Klaus}, journal = {Physical Review B - Condensed Matter and Materials Physics}, number = {19}, publisher = {American Physical Society}, title = {{Kinetic origin of island intermixing during the growth of Ge on Si (001)}}, doi = {10.1103/PhysRevB.72.195320}, volume = {72}, year = {2005}, } @article{1740, abstract = {A systematic study of the morphology of self-organized islands in the InAs/GaAs(0 0 1) and Ge/Si(0 0 1) systems is presented, based on high-resolution scanning tunneling microscopy measurements. We demonstrate that in both cases two main island families coexist: smaller pyramids bound by one type of shallow facets and larger multifaceted domes. Their structure and facet orientation are precisely determined, thus solving a highly debated argument in the case of InAs/GaAs(0 0 1). The comparison between the two material systems reveals the existence of striking similarities that extend even to the nature of island precursors and to the islands that form when depositing InGaAs or GeSi alloys. The implications of these observations on a possible universal description of the Stranski-Krastanow growth mode are discussed with respect to recent theoretical results.}, author = {Costantini, Giovanni and Rastelli, Armando and Manzano, Carlos and Acosta-Diaz, P and Georgios Katsaros and Songmuang, Rudeeson and Schmidt, Oliver G and Von Känel, Hans and Kern, Klaus}, journal = {Journal of Crystal Growth}, number = {1-4}, pages = {38 -- 45}, publisher = {Elsevier}, title = {{Pyramids and domes in the InAs/GaAs (0 0 1) and Ge/Si (0 0 1) systems}}, doi = {10.1016/j.jcrysgro.2004.12.047}, volume = {278}, year = {2005}, } @article{1743, abstract = {Laterally aligned multilayer GeSiSi islands grown on a patterned Si (001) substrate are disclosed by selective etching of Si in a KOH solution. This procedure allows us to visualize the vertical alignment of the islands in a three-dimensional perspective. Our technique reveals that partly coalesced double islands in the initial layer do not merge together, but instead gradually reproduce into well-separated double islands in upper layers. We attribute this effect to very thin spacer layers, which efficiently transfer the strain modulation of each island through the spacer layer to the surface. The etching rate of Si is reduced in tensile strained regions, which helps to preserve sufficient Si between the stacked islands to form a periodic array of freestanding and vertically modulated heterostructure pillars.}, author = {Zhong, Zheyang and Georgios Katsaros and Stoffel, Mathieu and Costantini, Giovanni and Kern, Klaus and Schmidt, Oliver G and Jin-Phillipp, Neng Y and Bauer, Günther}, journal = {Applied Physics Letters}, number = {26}, pages = {1 -- 3}, publisher = {American Institute of Physics}, title = {{Periodic pillar structures by Si etching of multilayer GeSi/Si islands}}, doi = {10.1063/1.2150278}, volume = {87}, year = {2005}, } @article{1744, abstract = {This paper presents optical duobinary and dicode signalling, as alternatives to the binary format, in order to improve the transmission performance in the presense of non-linear effects in a dense wavelength division multiplex (WDM) optical system. Duobinary signalling is applied to an optical system to explore the reduction of stimulated Brillouin scattering (SBS) effects. Duobinary signalling suppresses the SBS effects, and an eye-opening improvement of 0.25 to 1.2 dB is achieved relative to binary transmission over a range of input power levels. An experimental study demonstrates that duobinary modulation suppresses the four wave mixing (FWM) products of a dense WDM system by a maximum of 3 dB. The suppression is maintained over a range of channel spacings. An investigation of the impact of fibre dispersion on FWM products under binary, duobinary and dicode modulation in a dense WDM system is then performed, with interchannel spacing and optical power variation. This leads to the development of a set of guidelines for the application areas, in which it is appropriate to use duobinary or dicode modulation in WDM systems as a means of mitigating the impact of FWM.}, author = {Georgios Katsaros and Darwazeh, Izzat Z and Lane, Phil M}, journal = {IEE Proceedings - Optoelectronics}, number = {6}, pages = {344 -- 352}, publisher = {Institute of Electrical Engineers}, title = {{Non linear transmission effects in duobinary and dicode optical systems}}, doi = {10.1049/ip-opt:20045067}, volume = {152}, year = {2005}, } @article{1741, abstract = {SiGe islands move laterally on a Si(001) substrate during in situ postgrowth annealing. This surprising behavior is revealed by an analysis of the substrate surface morphology after island removal using wet chemical etching. We explain the island motion by asymmetric surface-mediated alloying. Material leaves one side of the island by surface diffusion, and mixes with additional Si from the surrounding surface as it redeposits on the other side. Thus the island moves laterally while becoming larger and more dilute.}, author = {Denker, Ulrich and Rastelli, Armando and Stoffel, Mathieu and Tersoff, Jerry and Georgios Katsaros and Costantini, Giovanni and Kern, Klaus and Jin-Phillipp, Neng Y and Jesson, David E and Schmidt, Oliver G}, journal = {Physical Review Letters}, number = {21}, publisher = {American Physical Society}, title = {{Lateral motion of SiGe islands driven by surface-mediated alloying}}, doi = {10.1103/PhysRevLett.94.216103}, volume = {94}, year = {2005}, } @article{1795, abstract = {Background: Murine leukemia virus (MLV) vector particles can be pseudotyped with a truncated variant of the human immunodeficiency virus type 1 (HIV-1) envelope protein (Env) and selectively target gene transfer to human cells expressing both CD4 and an appropriate co-receptor. Vector transduction mimics the HIV-1 entry process and is therefore a safe tool to study HIV-1 entry. Results: Using FLY cells, which express the MLV gag and pol genes, we generated stable producer cell lines that express the HIV-1 envelope gene and a retroviral vector genome encoding the green fluorescent protein (GFP). The BH10 or 89.6 P HIV-1 Env was expressed from a bicistronic vector which allowed the rapid selection of stable cell lines. A codon-usage-optimized synthetic env gene permitted high, Rev-independent Env expression. Vectors generated by these producer cells displayed different sensitivity to entry inhibitors. Conclusion: These data illustrate that MLV/HIV-1 vectors are a valuable screening system for entry inhibitors or neutralizing antisera generated by vaccines.}, author = {Sandra Siegert and Thaler, Sonja and Wagner, Ralf and Schnierle, Barbara S}, journal = {AIDS Research and Therapy}, number = {1}, publisher = {BioMed Central}, title = {{Assessment of HIV-1 entry inhibitors by MLV/HIV-1 pseudotyped vectors}}, doi = {10.1186/1742-6405-2-7}, volume = {2}, year = {2005}, } @article{1962, abstract = { Complex I of respiratory chains plays a central role in bioenergetics and is implicated in many human neurodegenerative diseases. An understanding of its mechanism requires a knowledge of the organization of redox centers. The arrangement of iron-sulfur clusters in the hydrophilic domain of complex I from Thermus thermophilus has been determined with the use of x-ray crystallography. One binuclear and six tetranuclear clusters are arranged, maximally 14 angstroms apart, in an 84-angstrom-long electron transfer chain. The binuclear cluster N1a and the tetranuclear cluster N7 are not in this pathway. Cluster N1a may play a role in the prevention of oxidative damage. The structure provides a framework for the interpretation of the large amounts of data accumulated on complex I.}, author = {Hinchliffe, Philip and Leonid Sazanov}, journal = {Science}, number = {5735}, pages = {771 -- 774}, publisher = {American Association for the Advancement of Science}, title = {{Biochemistry: Organization of iron-sulfur clusters in respiratory complex I}}, doi = {10.1126/science.1113988}, volume = {309}, year = {2005}, } @book{210, abstract = {Harold Davenport was one of the truly great mathematicians of the twentieth century. Based on lectures he gave at the University of Michigan in the early 1960s, this book is concerned with the use of analytic methods in the study of integer solutions to Diophantine equations and Diophantine inequalities. It provides an excellent introduction to a timeless area of number theory that is still as widely researched today as it was when the book originally appeared. The three main themes of the book are Waring's problem and the representation of integers by diagonal forms, the solubility in integers of systems of forms in many variables, and the solubility in integers of diagonal inequalities. For the second edition of the book a comprehensive foreword has been added in which three prominent authorities describe the modern context and recent developments. A thorough bibliography has also been added.}, author = {Davenport, Harold and Browning, Timothy D}, pages = {140}, publisher = {Cambridge University Press}, title = {{Analytic Methods for Diophantine Equations and Diophantine Inequalities}}, doi = {10.1017/CBO9780511542893}, year = {2005}, } @article{211, abstract = {Let f ∈ ℤ[x] be a polynomial of degree d. The paucity of non-trivial positive integer solutions to the equation f(x1)+f(x 2)=f(x3)+f(x4) is established, provided that d ≤ 7$. Also the corresponding situation is investigated for equal sums of three like polynomials.}, author = {Timothy Browning}, journal = {Bulletin of the London Mathematical Society}, number = {6}, pages = {801 -- 808}, publisher = {John Wiley and Sons Ltd}, title = {{Equal sums of like polynomials}}, doi = {10.1112/S0024609305004741}, volume = {37}, year = {2005}, } @article{212, abstract = {For any n ≧ 2, let F ∈ ℤ [ x 1, … , xn ] be a form of degree d≧ 2, which produces a geometrically irreducible hypersurface in ℙn–1. This paper is concerned with the number N(F;B) of rational points on F = 0 which have height at most B. For any ε > 0 we establish the estimate N(F; B) = O(B n− 2+ ε ), whenever either n ≦ 5 or the hypersurface is not a union of lines. Here the implied constant depends at most upon d, n and ε.}, author = {Timothy Browning and Heath-Brown, Roger}, journal = {Journal fur die Reine und Angewandte Mathematik}, number = {584}, pages = {83 -- 115}, publisher = {Walter de Gruyter and Co }, title = {{Counting rational points on hypersurfaces}}, doi = {https://doi.org/10.1515/crll.2005.2005.584.83}, year = {2005}, } @article{214, abstract = {Given an absolutely irreducible ternary form F, the purpose of this paper is to produce better upper bounds for the number of integer solutions to the equation F=0, that are restricted to lie in very lopsided boxes. As an application of the main result, a new paucity estimate is obtained for equal sums of two like powers.}, author = {Timothy Browning and Heath-Brown, Roger}, journal = {Mathematische Zeitschrift}, number = {2}, pages = {233 -- 247}, publisher = {Unknown}, title = {{Plane curves in boxes and equal sums of two powers}}, doi = {10.1007/s00209-004-0719-z}, volume = {251}, year = {2005}, } @article{217, abstract = {We show that the number of nontrivial rational points of height at most B, which lie on the cubic surface x1 x2 x3 = x4 (x1 + x2 + x3)2, has order of magnitude B (log B)6. This agrees with Manin's conjecture.}, author = {Timothy Browning}, journal = {Journal of Number Theory}, number = {2}, pages = {242 -- 283}, publisher = {Elsevier}, title = {{The density of rational points on a certain singular cubic surface}}, doi = {10.1016/j.jnt.2005.11.007}, volume = {119}, year = {2005}, } @article{2307, abstract = {The human norepinephrine (NE) transporter (hNET) attenuates neuronal signaling by rapid NE clearance from the synaptic cleft, and NET is a target for cocaine and amphetamines as well as therapeutics for depression, obsessive-compulsive disorder, and post-traumatic stress disorder. In spite of its central importance in the nervous system, little is known about how NET substrates, such as NE, 1-methyl-4-tetrahydropyridinium (MPP+), or amphetamine, interact with NET at the molecular level. Nor do we understand the mechanisms behind the transport rate. Previously we introduced a fluorescent substrate similar to MPP+, which allowed separate and simultaneous binding and transport measurement (Schwartz, J. W., Blakely, R. D., and DeFelice, L. J. (2003) J. Biol. Chem. 278, 9768-9777). Here we use this substrate, 4-(4-(dimethylamino)styrl)-N-methyl-pyridinium (ASP+), in combination with green fluorescent protein-tagged hNETs to measure substrate-transporter stoichiometry and substrate binding kinetics. Calibrated confocal microscopy and fluorescence correlation spectroscopy reveal that hNETs, which are homo-multimers, bind one substrate molecule per transporter subunit. Substrate residence at the transporter, obtained from rapid on-off kinetics revealed in fluorescence correlation spectroscopy, is 526 μs. Substrate residence obtained by infinite dilution is 1000 times slower. This novel examination of substrate-transporter kinetics indicates that a single ASP + molecule binds and unbinds thousands of times before being transported or ultimately dissociated from hNET. Calibrated fluorescent images combined with mass spectroscopy give a transport rate of 0.06 ASP +/hNET-protein/s, thus 36,000 on-off binding events (and 36 actual departures) occur for one transport event. Therefore binding has a low probability of resulting in transport. We interpret these data to mean that inefficient binding could contribute to slow transport rates.}, author = {Schwartz, Joel W and Gaia Novarino and Piston, David W and DeFelice, Louis J}, journal = {Journal of Biological Chemistry}, number = {19}, pages = {19177 -- 19184}, publisher = {American Society for Biochemistry and Molecular Biology}, title = {{Substrate binding stoichiometry and kinetics of the norepinephrine transporter}}, doi = {10.1074/jbc.M412923200}, volume = {280}, year = {2005}, } @book{2335, abstract = {This book contains a unique survey of the mathematically rigorous results about the quantum-mechanical many-body problem that have been obtained by the authors in the past seven years. It addresses a topic that is not only rich mathematically, using a large variety of techniques in mathematical analysis, but is also one with strong ties to current experiments on ultra-cold Bose gases and Bose-Einstein condensation. The book provides a pedagogical entry into an active area of ongoing research for both graduate students and researchers. It is an outgrowth of a course given by the authors for graduate students and post-doctoral researchers at the Oberwolfach Research Institute in 2004. The book also provides a coherent summary of the field and a reference for mathematicians and physicists active in research on quantum mechanics.}, author = {Lieb, Élliott and Seiringer, Robert and Solovej, Jan and Yngvason, Jakob}, isbn = {978-3-7643-7336-8}, pages = {VIII, 203}, publisher = {Birkhäuser Verlag}, title = {{The Mathematics of the Bose gas and its Condensation}}, doi = {10.1007/b137508}, volume = {34}, year = {2005}, } @inbook{2336, abstract = { Now that the low temperature properties of quantum-mechanical many-body systems (bosons) at low density, ρ, can be examined experimentally it is appropriate to revisit some of the formulas deduced by many authors 4–5 decades ago, and to explore new regimes not treated before. For systems with repulsive (i.e. positive) interaction potentials the experimental low temperature state and the ground state are effectively synonymous — and this fact is used in all modeling. In such cases, the leading term in the energy/particle is 2πħ2 aρ/m where a is the scattering length of the two-body potential. Owing to the delicate and peculiar nature of bosonic correlations (such as the strange N 7/5 law for charged bosons), four decades of research failed to establish this plausible formula rigorously. The only previous lower bound for the energy was found by Dyson in 1957, but it was 14 times too small. The correct asymptotic formula has been obtained by us and this work will be presented. The reason behind the mathematical difficulties will be emphasized. A different formula, postulated as late as 1971 by Schick, holds in two dimensions and this, too, will be shown to be correct. With the aid of the methodology developed to prove the lower bound for the homogeneous gas, several other problems have been successfully addressed. One is the proof by us that the Gross-Pitaevskii equation correctly describes the ground state in the ‘traps’ actually used in the experiments. For this system it is also possible to prove complete Bose condensation and superfluidity as we have shown. On the frontier of experimental developments is the possibility that a dilute gas in an elongated trap will behave like a one-dimensional system; we have proved this mathematically. Another topic is a proof that Foldy’s 1961 theory of a high density Bose gas of charged particles correctly describes its ground state energy; using this we can also prove the N 7/5 formula for the ground state energy of the two-component charged Bose gas proposed by Dyson in 1967. All of this is quite recent work and it is hoped that the mathematical methodology might be useful, ultimately, to solve more complex problems connected with these interesting systems.}, author = {Lieb, Élliott H and Robert Seiringer and Solovej, Jan P and Yngvason, Jakob}, booktitle = {Perspectives in Analysis}, editor = {Benedicks, Michael and Jones, Peter W and Smirnov, Stanislav and Winckler, Björn}, pages = {97 -- 183}, publisher = {Springer}, title = {{The quantum-mechanical many-body problem: The Bose gas}}, doi = {10.1007/3-540-30434-7_9}, volume = {27}, year = {2005}, } @article{2359, abstract = {The validity of substituting a c-number z for the k = 0 mode operator a0 is established rigorously in full generality, thereby verifying one aspect of Bogoliubov's 1947 theory. This substitution not only yields the correct value of thermodynamic quantities such as the pressure or ground state energy, but also the value of |z|2 that maximizes the partition function equals the true amount of condensation in the presence of a gauge-symmetry-breaking term. This point had previously been elusive.}, author = {Lieb, Élliott H and Robert Seiringer and Yngvason, Jakob}, journal = {Physical Review Letters}, number = {8}, publisher = {American Physical Society}, title = {{Justification of c-number substitutions in bosonic hamiltonians}}, doi = {10.1103/PhysRevLett.94.080401}, volume = {94}, year = {2005}, } @article{2362, abstract = {Recent developments in the physics of low-density trapped gases make it worthwhile to verify old, well-known results that, while plausible, were based on perturbation theory and assumptions about pseudopotentials. We use and extend recently developed techniques to give a rigorous derivation of the asymptotic formula for the ground-state energy of a dilute gas of N fermions interacting with a short-range, positive potential of scattering length a. For spin-12 fermions, this is E∼E0+(22m)2πNa, where E0 is the energy of the noninteracting system and is the density. A similar formula holds in two dimensions (2D), with a replaced by ln(a2). Obviously this 2D energy is not the expectation value of a density-independent pseudopotential.}, author = {Lieb, Élliott H and Robert Seiringer and Solovej, Jan P}, journal = {Physical Review A - Atomic, Molecular, and Optical Physics}, number = {5}, publisher = {American Physical Society}, title = {{Ground state energy of the low density Fermi gas}}, doi = {10.1103/PhysRevA.71.053605}, volume = {71}, year = {2005}, } @article{2361, abstract = {The strong subadditivity of entropy plays a key role in several areas of physics and mathematics. It states that the entropy S[±]=- Tr(ϱlnϱ) of a density matrix ϱ123 on the product of three Hilbert spaces satisfies S[ϱ123]- S[ϱ12]≤S[ϱ23]-S[ϱ2]. We strengthen this to S[ϱ123]-S[ϱ12] ≤αnα(S[ϱ23α]-S[ϱ2α]), where the nα are weights and the ϱ23α are partitions of ϱ23. Correspondingly, there is a strengthening of the theorem that the map A|Trexp[L+lnA] is concave. As applications we prove some monotonicity and convexity properties of the Wehrl coherent state entropy and entropy inequalities for quantum gases.}, author = {Lieb, Élliott H and Robert Seiringer}, journal = {Physical Review A - Atomic, Molecular, and Optical Physics}, number = {6}, publisher = {American Physical Society}, title = {{Stronger subadditivity of entropy}}, doi = {10.1103/PhysRevA.71.062329}, volume = {71}, year = {2005}, } @inproceedings{2428, abstract = {We consider an online version of the conflict-free coloring of a set of points on the line, where each newly inserted point must be assigned a color upon insertion, and at all times the coloring has to be conflict-free, in the sense that in every interval I there is a color that appears exactly once in I. We present several deterministic and randomized algorithms for achieving this goal, and analyze their performance, that is, the maximum number of colors that they need to use, as a function of the number n of inserted points. We first show that a natural and simple (deterministic) approach may perform rather poorly, requiring Ω(√n) colors in the worst case. We then modify this approach, to obtain an efficient deterministic algorithm that uses a maximum of Θ(log 2 n) colors. Next, we present two randomized solutions. The first algorithm requires an expected number of at most O(log 2 n) colors, and produces a coloring which is valid with high probability, and the second one, which is a variant of our efficient deterministic algorithm, requires an expected number of at most O(log n log log n) colors but always produces a valid coloring. We also analyze the performance of the simplest proposed algorithm when the points are inserted in a random order, and present an incomplete analysis that indicates that, with high probability, it uses only O(log n) colors. Finally, we show that in the extension of this problem to two dimensions, where the relevant ranges are disks, n colors may be required in the worst case. The average-case behavior for disks, and cases involving other planar ranges, are still open.}, author = {Fiat, Amos and Levy, Meital B and Matoušek, Jiří and Pach, Elchanan M and Sharir, Micha and Smorodinsky, Shakhar and Uli Wagner and Welzl, Emo}, pages = {545 -- 554}, publisher = {SIAM}, title = {{Online conflict-free coloring for intervals}}, doi = {10.1137/S0097539704446682}, year = {2005}, } @article{2427, abstract = {Intersection graphs of disks and of line segments, respectively, have been well studied, because of both practical applications and theoretically interesting properties of these graphs. Despite partial results, the complexity status of the Clique problem for these two graph classes is still open. Here, we consider the Clique problem for intersection graphs of ellipses, which, in a sense, interpolate between disks and line segments, and show that the problem is APX-hard in that case. Moreover, this holds even if for all ellipses, the ratio of the larger over the smaller radius is some prescribed number. Furthermore, the reduction immediately carries over to intersection graphs of triangles. To our knowledge, this is the first hardness result for the Clique problem in intersection graphs of convex objects with finite description complexity. We also describe a simple approximation algorithm for the case of ellipses for which the ratio of radii is bounded.}, author = {Ambühl, Christoph and Uli Wagner}, journal = {Theory of Computing Systems}, number = {3}, pages = {279 -- 292}, publisher = {Springer}, title = {{The Clique problem in intersection graphs of ellipses and triangles}}, doi = {10.1007/s00224-005-1141-6}, volume = {38}, year = {2005}, } @article{2455, abstract = {Local accumulation of the plant growth regulator auxin mediates pattern formation in Arabidopsis roots and influences outgrowth and development of lateral root- and shoot-derived primordia. However, it has remained unclear how auxin can simultaneously regulate patterning and organ outgrowth and how its distribution is stabilized in a primordium-specif ic manner. Here we show that five PIN genes collectively control auxin distribution to regulate cell division and cell expansion in the primary root. Furthermore, the joint action of these genes has an important role in pattern formation by focusing the auxin maximum and restricting the expression domain of PLETHORA (PLT) genes, major determinants for root stem cell specification. In turn, PLT genes are required for PIN gene transcription to stabilize the auxin maximum at the distal root tip. Our data reveal an interaction network of auxin transport facilitators and root fate determinants that control patterning and growth of the root primordium.}, author = {Billou, Ikram and Xu, Jian and Wildwater, Marjolein and Willemsen, Viola and Paponov, Ivan A and Jirí Friml and Heldstra, Renze and Aida, Mitsuhiro and Palme, Klaus J and Scheres, Ben}, journal = {Nature}, number = {7021}, pages = {39 -- 44}, publisher = {Nature Publishing Group}, title = {{The PIN auxin efflux facilitator network controls growth and patterning in Arabidopsis roots}}, doi = {10.1038/nature03184}, volume = {433}, year = {2005}, } @inbook{2464, author = {Jirí Friml and Wiśniewska, Justyna}, booktitle = {Intercellular Communication in Plants}, editor = {Fleming, Andrew J.}, publisher = {Wiley-Blackwell}, title = {{Auxin as an intercellular signal}}, volume = {16}, year = {2005}, } @inbook{2463, author = {Dubová, J and Hejátko, Jan and Jirí Friml}, booktitle = {Encyclopedia of Molecular Cell Biology and Molecular Medicine}, editor = {Meyers, Robert A}, pages = {249 -- 295}, publisher = {Wiley-Blackwell}, title = {{Reproduction, plants}}, doi = {10.1002/3527600906}, volume = {12}, year = {2005}, } @article{2648, abstract = {Hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels are involved in the control of neuronal excitability and plasticity. In this study, we used immunoblotting and immunohistochemical techniques to reveal the developmental expression and subcellular distribution of the HCN1 subunit in the cerebellar cortex. During postnatal development, the spatio-temporal expression of HCN1 correlated well with the morphological events occurring during the ontogenesis of cerebellar interneurons. Using immunoblotting techniques, HCN1 was weakly detected during the first postnatal week and continued to increase throughout postnatal development, peaking at postnatal day (P)15. At the light-microscopic level, HCN1 immunoreactivity was very weak until P7 whereas from P10-12 to adulthood it was strongly detected in the lower third of the molecular layer and in the Purkinje cell layer. HCN1 was present in axons running through the molecular layer and in the pericellular basket around Purkinje cells at P12, but in the periaxonal plexus (the pinceau) surrounding their initial segment only after P15. Using immunofluorescence, HCN1 colocalized with GAD65 and synaptophysin, demonstrating that the subunit was present in inhibitory axons and axon terminals. At the electron-microscopic level, in adulthood, HCN1 immunoparticles were detected at postsynaptic sites in basket and Purkinje cells but most immunoparticles were found at presynaptic sites in basket cell axons and in terminals. In the axon terminals, the distribution of HCN1 was relatively uniform along the extrasynaptic plasma membrane; this was confirmed using quantitative techniques. The present findings suggest that HCN1 channels may provide a significant route for modulating co-ordinated cerebellar synaptic transmission through basket cells.}, author = {Luján, Rafael and Albasanz, José L and Ryuichi Shigemoto and Juíz, José M}, journal = {European Journal of Neuroscience}, number = {8}, pages = {2073 -- 2082}, publisher = {Wiley-Blackwell}, title = {{Preferential localization of the hyperpolarization-activated cyclic nucleotide-gated cation channel subunit HCN1 in basket cell terminals of the rat cerebellum}}, doi = {10.1111/j.1460-9568.2005.04043.x}, volume = {21}, year = {2005}, } @article{2650, abstract = {Septohippocampal cholinergic neurons play key roles in learning and memory processes, and in the generation of hippocampal theta rhythm. The range of receptors for endogenous modulators expressed on these neurons is unclear. Here we describe GABAB 1a/b receptor (GABABR) and type 1 cannabinoid receptor (CB1R) expression in rat septal cholinergic [i.e. choline acetyltransferase (ChAT)-positive] cells. Using double immunofluorescent staining, we found that almost two-thirds of the cholinergic cells in the rat medial septum were GABABR positive, and that these cells had significantly larger somata than did GABABR-negative cholinergic neurons. We detected CB1R labelling in somata after axonal protein transport was blocked by colchicine. In these animals about one-third of the cholinergic cells were CB1R positive. These cells again had larger somata than CB1R-negative cholinergic neurons. The analyses confirmed that the size of GABABR-positive and CB 1R-positive cholinergic cells were alike, and all CB 1R-positive cholinergic cells were GABABR positive as well. CB1R-positive cells were invariably ChAT positive. All retrogradely labelled septohippocampal cholinergic cells were positive for GABABR and at least half of them also for CB1R. These data shed light on the existence of at least two cholinergic cell types in the medial septum: one expresses GABABR and CB1R, has large somata and projects to the hippocampus, whereas the other is negative for GABABR and CB1R and has smaller somata. The results also suggest that cholinergic transmission in the hippocampus is fine-tuned by endocannabinoid signalling.}, author = {Nyíri, Gábor and Szabadits, Eszter and Cserép, Csaba and Mackie, Ken P and Ryuichi Shigemoto and Freund, Tamás F}, journal = {European Journal of Neuroscience}, number = {11}, pages = {3034 -- 3042}, publisher = {Wiley-Blackwell}, title = {{GABAB and CB1 cannabinoid receptor expression identifies two types of septal cholinergic neurons}}, doi = {10.1111/j.1460-9568.2005.04146.x}, volume = {21}, year = {2005}, } @misc{2647, abstract = {Our understanding of the role played by neurotransmitter receptors in the developing brain has advanced in recent years. The major excitatory and inhibitory neurotransmitters in the brain, glutamate and GABA, activate both ionotropic (ligand-gated ion channels) and metabotropic (G protein-coupled) receptors, and are generally associated with neuronal communication in the mature brain. However, before the emergence of their role in neurotransmission in adulthood, they also act to influence earlier developmental events, some of which occur prior to synapse formation: such as proliferation, migration, differentiation or survival processes during neural development. To fulfill these actions in the constructing of the nervous system, different types of glutamate and GABA receptors need to be expressed both at the right time and at the right place. The identification by molecular cloning of 16 ionotropic glutamate receptor subunits, eight metabotropic glutamate receptor subtypes, 21 ionotropic and two metabotropic GABA receptor subunits, some of which exist in alternatively splice variants, has enriched our appreciation of how molecular diversity leads to functional diversity in the brain. It now appears that many different types of glutamate and GABA receptor subunits have prominent expression in the embryonic and/or postnatal brain, whereas others are mainly present in the adult brain. Although the significance of this differential expression of subunits is not fully understood, it appears that the change in subunit composition is essential for normal development in particular brain regions. This review focuses on emerging information relating to the expression and role of glutamatergic and GABAergic neurotransmitter receptors during prenatal and postnatal development.}, author = {Luján, Rafael and Ryuichi Shigemoto and López-Bendito, Guillermina}, booktitle = {Neuroscience}, number = {3}, pages = {567 -- 580}, publisher = {Elsevier}, title = {{Glutamate and GABA receptor signalling in the developing brain}}, doi = {10.1016/j.neuroscience.2004.09.042}, volume = {130}, year = {2005}, } @article{2651, abstract = {The GABAergic system, a major inhibitory regulator in the central nervous system, may also play important roles in peripheral nonneuronal tissues and cells. Recent studies showed that GABAB receptor is expressed in testis and sperm. To understand the role of the GABAergic system in spermiogenesis, we examined cellular localization of GABA and GABAB receptor subunits in rat spermatids by immunocytochemistry. Immunoreactivity for GABA was detected around acrosomal granules of spermatids during the Golgi and cap phases. GABAB(1) immunoreactivity was observed in the acrosomal vesicle of spermatids in Golgi phase, and during cap phase, this reactivity expanded to the entire region of the acrosome covering the nuclear membrane. The level of reactivity decreased gradually with maturation of spermatids. In contrast, GABAB(2) immunoreactivity was not observed in spermatids during Golgi phase but was detected in the equatorial region during cap phase. Both GABA immunoreactivity and GABAB(2) immunoreactivity were transferred to the residual cytoplasm during the release of spermatozoa. Electron microscopic immunocytochemistry revealed that, during cap phase, GABA and GABAB(1) were distributed within the whole acrosomal vesicle but not in the acrosomal granule. GABAB(2) immunoreactivity was observed in the narrow space between the inner acrosomal and nuclear membrane and was limited to the equatorial region of the spermatid head. These results indicate that the GABAergic system might be involved in regulation of spermiogenesis.}, author = {Kanbara, Kiyoto and Okamoto, Keiko and Nomura, Sakashi and Kaneko, Takeshi and Ryuichi Shigemoto and Azuma, Haruhito and Katsuoka, Yoji and Watanabe, Masahiko}, journal = {Journal of Andrology}, number = {4}, pages = {485 -- 493}, publisher = {American Society of Andrology}, title = {{Cellular localization of GABA and GABAB receptor subunit proteins during spermiogenesis in rat testis}}, doi = {10.2164/jandrol.04185}, volume = {26}, year = {2005}, } @article{2649, abstract = {The number of ionotropic receptors in synapses is an essential factor for determining the efficacy of fast transmission. We estimated the number of functional AMPA receptors at single postsynaptic sites by a combination of two-photon uncaging of glutamate and the nonstationary fluctuation analysis in immature rat Purkinje cells (PCs), which receive a single type of excitatory input from climbing fibers. Areas of postsynaptic membrane specialization at the recorded synapses were measured by reconstruction of serial ultrathin sections. The number of functional AMPA receptors was proportional to the synaptic area with a density of ∼ 1280 receptors/μm 2. Moreover, highly sensitive freeze-fracture replica labeling revealed a homogeneous density of immunogold particles for AMPA receptors in synaptic sites (910 ± 36 particles/μm 2) and much lower density in extrasynaptic sites (19 ± 2 particles/μm 2) in the immature PCs. Our results indicate that in this developing synapse, the efficacy of transmission is determined by the synaptic area.}, author = {Tanaka, Junichi and Matsuzaki, Masanori and Tarusawa, Etsuko and Momiyama, Akiko and Molnár, Elek and Kasai, Haruo and Ryuichi Shigemoto}, journal = {Journal of Neuroscience}, number = {4}, pages = {799 -- 807}, publisher = {Society for Neuroscience}, title = {{Number and density of AMPA receptors in single synapses in immature cerebellum}}, doi = {10.1523/JNEUROSCI.4256-04.2005}, volume = {25}, year = {2005}, } @article{2654, abstract = {Presynaptic metabotropic glutamate receptors (mGluRs) show a highly selective expression and subcellular location in nerve terminals modulating neurotransmitter release. We have demonstrated that alternatively spliced variants of mGluR8, mGluR8a and mGluR8b, have an overlapping distribution in the hippocampus, and besides perforant path terminals, they are expressed in the presynaptic active zone of boutons making synapses selectively with several types of GABAergic interneurons, primarily in the stratum oriens. Boutons labeled for mGluR8 formed either type I or type II synapses, and the latter were GABAergic. Some mGluR8-positive boutons also expressed mGluR7 or vasoactive intestinal polypeptide. Interneurons strongly immunopositive for the muscarinic M2 or the mGlu1 receptors were the primary targets of mGluR8-containing terminals in the stratum oriens, but only neurochemically distinct subsets were innervated by mGluR8-enriched terminals. The majority of M2-positive neurons were mGluR8 innervated, but a minority, which expresses somatostatin, was not. Rare neurons coexpressing calretinin and M2 were consistently targeted by mGluR8-positive boutons. In vivo recording and labeling of an mGluR8-decorated and strongly M2-positive interneuron revealed a trilaminar cell with complex spike bursts during theta oscillations and strong discharge during sharp wave/ripple events. The trilaminar cell had a large projection from the CA1 area to the subiculum and a preferential innervation of interneurons in the CA1 area in addition to pyramidal cell somata and dendrites. The postsynaptic interneuron type-specific expression of the high-efficacy presynaptic mGluR8 in both putative glutamatergic and in identified GABAergic terminals predicts a role in adjusting the activity of interneurons depending on the level of network activity.}, author = {Ferraguti, Francesco and Klausberger,Thomas and Cobden, Philip M and Baude, Agnès and Roberts, John D and Szűcs, Péter and Kinoshita, Ayae and Ryuichi Shigemoto and Somogyi, Péter and Dalezios, Yannis}, journal = {Journal of Neuroscience}, number = {45}, pages = {10520 -- 10536}, publisher = {Society for Neuroscience}, title = {{ Metabotropic glutamate receptor 8-expressing nerve terminals target subsets of GABAergic neurons in the hippocampus}}, doi = {10.1523/JNEUROSCI.2547-05.2005}, volume = {25}, year = {2005}, } @article{2658, abstract = {Enhanced glutamatergic neurotransmission via the subthalamopallidal or subthalamonigral projection seems crucial for developing parkinsonian motor signs. In the present study, the possible changes in the expression of metabotropic glutamate receptors (mGluRs) were examined in the basal ganglia of a primate model for Parkinson's disease. When the patterns of immunohistochemical localization of mGluRs in monkeys administered systemically with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were analysed in comparison with normal controls, we found that expression of mGluR1α, but not of other subtypes, was significantly reduced in the internal and external segments of the globus pallidus and the substantia nigra pars reticulata. To elucidate the functional role of mGluR1 in the control of pallidal neuron activity, extracellular unit recordings combined with intrapallidal microinjections of mGluR1-related agents were then performed in normal and parkinsonian monkeys. In normal awake conditions, the spontaneous firing rates of neurons in the pallidal complex were increased by DHPG, a selective agonist of group I mGluRs, whereas they were decreased by AIDA, a selective antagonist of group I mGluRs, or LY367385, a selective antagonist of mGluR1. These electrophysiological data strongly indicate that the excitatory mechanism of pallidal neurons by glutamate is mediated at least partly through mGluR1. The effects of the mGluR1-related agents on neuronal firing in the internal pallidal segment became rather obscure after MPTP treatment. Our results suggest that the specific down-regulation of pallidal and nigral mGluR1 ot in the parkinsonian state may exert a compensatory action to reverse the overactivity of the subthalamic nucleus-derived glutamatergic input that is generated in the disease.}, author = {Kaneda, Katsuyuki and Tachibana, Yoshihisa and Imanishi, Michiko and Kita, Hitoshi and Ryuichi Shigemoto and Nambu, Atsushi and Takada, Masahiko}, journal = {European Journal of Neuroscience}, number = {12}, pages = {3241 -- 3254}, publisher = {Wiley-Blackwell}, title = {{Down-regulation of metabotropic glutamate receptor 1α in globus pallidus and substantia nigra of parkinsonian monkeys}}, doi = {10.1111/j.1460-9568.2005.04488.x}, volume = {22}, year = {2005}, } @article{2652, abstract = {We studied neurogliaform neurons in the stratum lacunosum moleculare of the CA1 hippocampal area. These interneurons have short stellate dendrites and an extensive axonal arbor mainly located in the stratum lacunosum moleculare. Single-cell reverse transcription-PCR showed that these neurons were GABAergic and that the majority expressed mRNA for neuropeptide Y. Most neurogliaform neurons tested were immunoreactive for α-actinin-2, and many stratum lacunosum moleculare interneurons coexpressed α-actinin-2 and neuropeptide Y. Neurogliaform neurons received monosynaptic, DNQX-sensitive excitatory input from the perforant path, and 40 Hz stimulation of this input evoked EPSCs displaying either depression or initial facilitation, followed by depression. Paired recordings performed between neurogliaform neurons showed that 85% of pairs were electrically connected and 70% were also connected via GABAergic synapses. Injection of sine waveforms into neurons during paired recordings resulted in transmission of the waveforms through the electrical synapse. Unitary IPSCs recorded from neurogliaform pairs readily fatigued, had a slow decay, and had a strong depression of the synaptic response at a 5 Hz stimulation frequency that was antagonized by the GABA B antagonist (2S)-3-[[(1S)-1-(3,4-dichlorophenyl)ethyl]amino-2-hydroxypropyl](phenylmethyl) phosphinic acid (CGP55845). The amplitude of the first IPSC during the 5 Hz stimulation was also increased by CGP55845, suggesting a tonic inhibition of synaptic transmission. A small unitary GABA B-mediated IPSC could also be detected, providing the first evidence for such a component between GABAergic interneurons. Electron microscopic localization of the GABA B1 subunit at neurogliaform synapses revealed the protein in both presynaptic and postsynaptic membranes. Our data disclose a novel interneuronal network well suited for modulating the flow of information between the entorhinal cortex and CA1 hippocampus.}, author = {Price, Christopher J and Cauli, Bruno and Kovács, Endre R and Kulik, Ákos and Lambolez, Bertrand and Ryuichi Shigemoto and Capogna,Marco}, journal = {Journal of Neuroscience}, number = {29}, pages = {6775 -- 6786}, publisher = {Society for Neuroscience}, title = {{Neurogliaform neurons form a novel inhibitory network in the hippocampal CA1 area}}, doi = {10.1523/JNEUROSCI.1135-05.2005}, volume = {25}, year = {2005}, } @article{2655, abstract = {Input-dependent left-right asymmetry of NMDA receptor ε2 (NR2B) subunit allocation was discovered in hippocampal Schaffer collateral (Sch) and commissural fiber pyramidal cell synapses (Kawakami et al., 2003). To investigate whether this asymmetrical ε2 allocation is also related to the types of the postsynaptic cells, we compared postembedding immunogold labeling for ε2 in left and right Sch synapses on pyramidal cells and interneurons. To facilitate the detection of ε2 density difference, we used ε1 (NR2A) knock-out (KO) mice, which have a simplified NMDA receptor subunit composition. The labeling density for ε2 but not ζ1 (NR1) and subtype 2/3 glutamate receptor (GluR2/3) in Sch-CA1 pyramidal cell synapses was significantly different between the left and right hippocampus with opposite directions in strata oriens and radiatum; the left to right ratio of ε2 labeling density was 1:1.50 in stratum oriens and 1.44:1 in stratum radiatum. No significant difference, however, was detected in CA1 stratum radiatum between the left and right Sch-GluR4-positive (mostly parvalbumin-positive) and Sch-GluR4-negative interneuron synapses. Consistent with the anatomical asymmetry, the amplitude ratio of NMDA EPSCs to non-NMDA EPSCs in pyramidal cells was approximately two times larger in right than left stratum radiatum and vice versa in stratum oriens of ε1 KO mice. Moreover, the amplitude of long-term potentiation in the Sch-CA1 synapses of left stratum radiatum was significantly larger than that in the right corresponding synapses. These results indicate that the asymmetry of ε2 distribution is target cell specific, resulting in the left-right difference in NMDA receptor content and plasticity in Sch-CA1 pyramidal cell synapses in ε1 KO mice.}, author = {Wu, Yue and Kawakami, Ryosuke and Shinohara, Yoshiaki and Fukaya, Masahiro and Sakimura, Kenji and Mishina, Masayoshi and Watanabe, Masahiko and Ito, Isao and Ryuichi Shigemoto}, journal = {Journal of Neuroscience}, number = {40}, pages = {9213 -- 9226}, publisher = {Society for Neuroscience}, title = {{Target-cell-specific left-right asymmetry of NMDA receptor content in Schaffer collateral synapses in ε1/NR2A knock-out mice}}, doi = {10.1523/JNEUROSCI.2134-05.2005}, volume = {25}, year = {2005}, } @article{2653, abstract = {Synaptic vesicle release occurs at a specialized membrane domain known as the presynaptic active zone (AZ). Several membrane proteins are involved in the vesicle release processes such as docking, priming, and exocytotic fusion. Cytomatrix at the active zone (CAZ) proteins are structural components of the AZ and are highly concentrated in it. Localization of other release-related proteins including target soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (t-SNARE) proteins, however, has not been well demonstrated in the AZ. Here, we used sodium dodecyl sulfate-digested freeze-fracture replica labeling (SDS-FRL) to analyze quantitatively the distribution of CAZ and t-SNARE proteins in the hippocampal CA3 area. The AZ in replicated membrane was identified by immunolabeling for CAZ proteins (CAZ-associated structural protein [CAST] and Bassoon). Clusters of immunogold particles for these proteins were found on the P-face of presynaptic terminals of the mossy fiber and associational/commissural (AJC) fiber. Co-labeling with CAST revealed distribution of the t-SNARE proteins syntaxin and synaptosomal-associated protein of 25 kDa (SNAP-25) in the AZ as well as in the extrasynaptic membrane surrounding the AZ (SZ). Quantitative analysis demonstrated that the density of immunoparticles for CAST in the AZ was more than 100 times higher than in the SZ, whereas that for syntaxin and SNAP-25 was not significantly different between the AZ and SZ in both the A/C and mossy fiber terminals. These results support the involvement of the t-SNARE proteins in exocytotic fusion in the AZ and the role of CAST in specialization of the membrane domain for the AZ.}, author = {Hagiwara, Akari and Fukazawa, Yugo and Deguchi-Tawarada, Maki and Ohtsuka, Toshihisa and Ryuichi Shigemoto}, journal = {Journal of Comparative Neurology}, number = {2}, pages = {195 -- 216}, publisher = {Wiley-Blackwell}, title = {{Differential distribution of release-related proteins in the hippocampal CA3 area as revealed by freeze-fracture replica labeling}}, doi = {10.1002/cne.20633}, volume = {489}, year = {2005}, } @article{2656, abstract = {Previous studies have shown that neurons in the sacral dorsal commissural nucleus (SDCN) express neurokinin-1 receptor (NK1R) and can be modulated by the co-release of GABA and glycine (Gly) from single presynaptic terminal. These results raise the possibility that GABA/Gly-cocontaining terminals might make synaptic contacts with NK1R-expressing neurons in the SDCN. In order to provide morphological evidence for this hypothesis, the triple-immunohistochemical studies were performed in the SDCN. Triple-immunofluorescence histochemical study showed that some axon terminals in close association with NK1R-immunopositive (NK1R-ip) neurons in the SDCN were immunopositive for both glutamic acid decarboxylase (GAD) and glycine transporter 2 (GlyT2). In electron microscopic dual- and triple-immunohistochemistry for GAD/GlyT2, GAD/NK1R, GlyT2/NK1R, or GAD/GlyT2/NK1R also revealed dually labeled (GAD/GlyT2-ip) synaptic terminals upon SDCN neurons, as well as GAD- and/or GlyT2-ip axon terminals in synaptic contact with NK1R-ip SDCN neurons. These results suggested that some synaptic terminals upon NK1R-expressing SDCN neurons co-released both GABA and Gly.}, author = {Feng, Yu-Peng and Li, Yun-Qing and Wang, Wen and Wu, Sheng-Xi and Chen, Tao and Ryuichi Shigemoto and Mizuno, Noboru}, journal = {Neuroscience Letters}, number = {3}, pages = {144 -- 148}, publisher = {Elsevier}, title = {{Morphological evidence for GABA/glycine-cocontaining terminals in synaptic contact with neurokinin-1 receptor-expressing neurons in the sacral dorsal commissural nucleus of the rat}}, doi = {10.1016/j.neulet.2005.06.068}, volume = {388}, year = {2005}, } @article{2744, abstract = {We study the long time evolution of a quantum particle interacting with a random potential in the Boltzmann-Grad low density limit. We prove that the phase space density of the quantum evolution defined through the Husimi function converges weakly to a linear Boltzmann equation. The Boltzmann collision kernel is given by the full quantum scattering cross-section of the obstacle potential.}, author = {Eng, David and László Erdös}, journal = {Reviews in Mathematical Physics}, number = {6}, pages = {669 -- 743}, publisher = {World Scientific Publishing}, title = {{The linear Boltzmann equation as the low density limit of a random Schrödinger equation}}, doi = {10.1142/S0129055X0500242X}, volume = {17}, year = {2005}, } @article{2743, abstract = {We consider the supersymmetric quantum mechanical system which is obtained by dimensionally reducing d = 6, N = 1 supersymmetric gauge theory with gauge group U(1) and a single charged hypermultiplet. Using the deformation method and ideas introduced by Porrati and Rozenberg [1], we present a detailed proof of the existence of a normalizable ground state for this system.}, author = {László Erdös and Hasler, David G and Solovej, Jan P}, journal = {Annales Henri Poincare}, number = {2}, pages = {247 -- 267}, publisher = {Birkhäuser}, title = {{Existence of the D0-D4 bound state: A detailed proof}}, doi = {10.1007/s00023-005-0205-0}, volume = {6}, year = {2005}, } @article{2788, abstract = {We present the results of an experimental investigation into the nature and structure of turbulent pipe flow at moderate Reynolds numbers. A turbulence regeneration mechanism is identified which sustains a symmetric traveling wave within the flow. The periodicity of the mechanism allows comparison to the wavelength of numerically observed exact traveling wave solutions and close agreement is found. The advection speed of the upstream turbulence laminar interface in the experimental flow is observed to form a lower bound on the phase velocities of the exact traveling wave solutions. Overall our observations suggest that the dynamics of the turbulent flow at moderate Reynolds numbers are governed by unstable nonlinear traveling waves.}, author = {Björn Hof and van Doorne, Casimir W and Westerweel, Jerry and Nieuwstadt, Frans T}, journal = {Physical Review Letters}, number = {21}, publisher = {American Physical Society}, title = {{Turbulence regeneration in pipe flow at moderate reynolds numbers}}, doi = {10.1103/PhysRevLett.95.214502}, volume = {95}, year = {2005}, } @article{2790, abstract = {We present the results of an experimental investigation of the effect of a magnetic field on the stability of convection in a liquid metal. A rectangular container of gallium is subjected to a horizontal temperature gradient and a uniform magnetic field is applied separately in three directions. The magnetic field suppresses the oscillation most effectively when it is applied in the vertical direction and is least efficient when applied in the direction of the temperature gradient. The critical temperature difference required for the onset of oscillations is found to scale exponentially with the magnitude of the magnetic field for all three orientations. Comparisons are made with available theory and qualitative differences are discussed.}, author = {Björn Hof and Juel, Anne and Mullin, Tom P}, journal = {Journal of Fluid Mechanics}, pages = {193 -- 201}, publisher = {Cambridge University Press}, title = {{Magnetohydrodynamic damping of oscillations in low-Prandtl-number convection}}, doi = {10.1017/S0022112005006762}, volume = {545}, year = {2005}, } @article{2789, abstract = {Transitional pipe flow is investigated in two different experimental set-ups. In the first the stability threshold and the initial growth of localized perturbations are studied. Good agreement is found with an earlier investigation of the transition threshold. The measurement technique applied in the last part of this study allows the reconstruction of the streamwise vorticity in a turbulent puff.}, author = {Björn Hof}, journal = {Fluid Mechanics and its Applications}, pages = {221 -- 231}, publisher = {Springer}, title = {{Transition to turbulence in pipe flow}}, doi = {10.1007/1-4020-4049-0_12}, volume = {77}, year = {2005}, } @article{2867, abstract = {The plant hormone auxin elicits many specific context-dependent developmental responses. Auxin promotes degradation of Aux/IAA proteins that prevent transcription factors of the auxin response factor (ARF) family from regulating auxin-responsive target genes. Aux/IAAs and ARFs are represented by large gene families in Arabidopsis. Here we show that stabilization of BDL/IAA12 or its sister protein IAA13 prevents MP/ARF5-dependent embryonic root formation whereas stabilized SHY2/IAA3 interferes with seedling growth. Although both bdl and shy2-2 proteins inhibited MP/ARF5-dependent reporter gene activation, shy2-2 was much less efficient than bdl to interfere with embryonic root initiation when expressed from the BDL promoter. Similarly, MP was much more efficient than ARF16 in this process. When expressed from the SHY2 promoter, both shy2-2 and bdl inhibited cell elongation and auxin-induced gene expression in the seedling hypocotyl. By contrast, gravitropism and auxin-induced gene expression in the root, which were promoted by functionally redundant NPH4/ARF7 and ARF19 proteins, were inhibited by shy2-2, but not by bdl protein. Our results suggest that auxin signals are converted into specific responses by matching pairs of coexpressed ARF and Aux/IAA proteins.}, author = {Weijers, Dolf and Eva Benková and Jäger, Katja E and Schlereth, Alexandra and Hamann, Thorsten and Kientz, Marika and Wilmoth, Jill C and Reed, Jason W and Jürgens, Gerd}, journal = {EMBO Journal}, number = {10}, pages = {1874 -- 1885}, publisher = {Wiley-Blackwell}, title = {{Developmental specificity of auxin response by pairs of ARF and Aux/IAA transcriptional regulators}}, doi = {10.1038/sj.emboj.7600659}, volume = {24}, year = {2005}, } @article{2895, abstract = {One of the fundamental properties of the immune system is its capacity to avoid autoimmune diseases. The mechanism underlying this process, known as self-tolerance, is hitherto unresolved but seems to involve the control of clonal expansion of autoreactive lymphocytes. This article reviews mathematical modeling of self-tolerance, addressing two specific hypotheses. The first hypothesis posits that self-tolerance is mediated by tuning of activation thresholds, which makes autoreactive T lymphocytes reversibly "anergic" and unable to proliferate. The second hypothesis posits that the proliferation of autoreactive T lymphocytes is instead controlled by specific regulatory T lymphocytes. Models representing the population dynamics of autoreactive T lymphocytes according to these two hypotheses were derived. For each model we identified how cell density affects tolerance, and predicted the corresponding phase spaces and bifurcations. We show that the simple induction of proliferative anergy, as modeled here, has a density dependence that is only partially compatible with adoptive transfers of tolerance, and that the models of tolerance mediated by specific regulatory T cells are closer to the observations.}, author = {Carneiro, Jorge and Tiago Paixao and Milutinovic, Dejan and Sousa, João and Leon, Kalet and Gardner, Rui and Faro, Jose}, journal = {Journal of Computational and Applied Mathematics}, number = {1}, pages = {77 -- 100}, publisher = {Elsevier}, title = {{Immunological self tolerance: Lessons from mathematical modeling}}, doi = {10.1016/j.cam.2004.10.025}, volume = {184}, year = {2005}, }