@inproceedings{4462,
abstract = {A major hurdle in the algorithmic verification and control of systems is the need to find suitable abstract models, which omit enough details to overcome the state-explosion problem, but retain enough details to exhibit satisfaction or controllability with respect to the specification. The paradigm of counterexample-guided abstraction refinement suggests a fully automatic way of finding suitable abstract models: one starts with a coarse abstraction, attempts to verify or control the abstract model, and if this attempt fails and the abstract counterexample does not correspond to a concrete counterexample, then one uses the spurious counterexample to guide the refinement of the abstract model. We present a counterexample-guided refinement algorithm for solving ω-regular control objectives. The main difficulty is that in control, unlike in verification, counterexamples are strategies in a game between system and controller. In the case that the controller has no choices, our scheme subsumes known counterexample-guided refinement algorithms for the verification of ω-regular specifications. Our algorithm is useful in all situations where ω-regular games need to be solved, such as supervisory control, sequential and program synthesis, and modular verification. The algorithm is fully symbolic, and therefore applicable also to infinite-state systems.},
author = {Thomas Henzinger and Jhala, Ranjit and Majumdar, Ritankar S},
pages = {886 -- 902},
publisher = {Springer},
title = {{Counterexample-guided control}},
doi = {10.1007/3-540-45061-0_69},
volume = {2719},
year = {2003},
}
@inproceedings{4463,
abstract = {We present an algorithm called TAR (“Thread-modular Abstraction Refinement”) for model checking safety properties of concurrent software. The TAR algorithm uses thread-modular assume-guarantee reasoning to overcome the exponential complexity in the control state of multithreaded programs. Thread modularity means that TAR explores the state space of one thread at a time, making assumptions about how the environment can interfere. The TAR algorithm uses counterexample-guided predicate-abstraction refinement to overcome the usually infinite complexity in the data state of C programs. A successive approximation scheme automatically infers the necessary precision on data variables as well as suitable environment assumptions. The scheme is novel in that transition relations are approximated from above, while at the same time environment assumptions are approximated from below. In our software verification tool BLAST we have implemented a fully automatic race checker for multithreaded C programs which is based on the TAR algorithm. This tool has verified a wide variety of commonly used locking idioms, including locking schemes that are not amenable to existing dynamic and static race checkers such as ERASER or WARLOCK.},
author = {Thomas Henzinger and Jhala, Ranjit and Majumdar, Ritankar S and Qadeer,Shaz},
pages = {262 -- 274},
publisher = {Springer},
title = {{Thread-modular abstraction refinement}},
doi = {10.1007/978-3-540-45069-6_27},
volume = {2725},
year = {2003},
}
@inproceedings{4464,
abstract = {We introduce the paradigm of schedule-carrying code (SCC). A hard real-time program can be executed on a given platform only if there exists a feasible schedule for the real-time tasks of the program. Traditionally, a scheduler determines the existence of a feasible schedule according to some scheduling strategy. With SCC, a compiler proves the existence of a feasible schedule by generating executable code that is attached to the program and represents its schedule. An SCC executable is a real-time program that carries its schedule as code, which is produced once and can be revalidated and executed with each use. We evaluate SCC both in theory and practice. In theory, we give two scenarios, of nonpreemptive and distributed scheduling for Giotto programs, where the generation of a feasible schedule is hard, while the validation of scheduling instructions that are attached to the programs is easy. In practice, we implement SCC and show that explicit scheduling instructions can reduce the scheduling overhead up to 35% and can provide an efficient, flexible, and verifiable means for compiling Giotto programs on complex architectures, such as the TTA.},
author = {Thomas Henzinger and Kirsch, Christoph M and Matic, Slobodan},
pages = {241 -- 256},
publisher = {ACM},
title = {{Schedule-carrying code}},
doi = {10.1007/978-3-540-45212-6_16},
volume = {2855},
year = {2003},
}
@inbook{4465,
abstract = {Giotto is a principled, tool-supported design methodology for implementing embedded control systems on platforms of possibly distributed sensors, actuators, CPUs, and networks. Giotto is based on the principle that time-triggered task invocations plus time-triggered mode switches can form the abstract essence of programming real-time control systems. Giotto consists of a programming language with a formal semantics, and a retargetable compiler and runtime library. Giotto supports the automation of control system design by strictly separating platform-independent functionality and timing concerns from platform-dependent scheduling and communication issues. The time-triggered predictability of Giotto makes it particularly suitable for safety-critical applications with hard real-time constraints. We illustrate the platform independence and time-triggered execution of Giotto by coordinating a heterogeneous flock of Intel x86 robots and Lego Mindstorms robots.},
author = {Thomas Henzinger and Horowitz, Benjamin and Kirsch, Christoph M},
booktitle = {Software-Enabled Control: Information Technology for Dynamical Systems},
pages = {123 -- 146},
publisher = {Wiley-Blackwell},
title = {{Embedded control systems development with Giotto}},
doi = {10.1002/047172288X.ch8},
year = {2003},
}
@inproceedings{4466,
abstract = {One source of complexity in the μ-calculus is its ability to specify an unbounded number of switches between universal (AX) and existential (EX) branching modes. We therefore study the problems of satisfiability, validity, model checking, and implication for the universal and existential fragments of the μ-calculus, in which only one branching mode is allowed. The universal fragment is rich enough to express most specifications of interest, and therefore improved algorithms are of practical importance. We show that while the satisfiability and validity problems become indeed simpler for the existential and universal fragments, this is, unfortunately, not the case for model checking and implication. We also show the corresponding results for the alternationfree fragment of the μ-calculus, where no alternations between least and greatest fixed points are allowed. Our results imply that efforts to find a polynomial-time model-checking algorithm for the μ-calculus can be replaced by efforts to find such an algorithm for the universal or existential fragment.},
author = {Thomas Henzinger and Kupferman, Orna and Majumdar, Ritankar S},
pages = {49 -- 64},
publisher = {Springer},
title = {{On the universal and existential fragments of the mu-calculus}},
doi = {10.1007/3-540-36577-X_5},
volume = {2619},
year = {2003},
}
@inproceedings{4467,
abstract = {BLAST (the Berkeley Lazy Abstraction Software verification Tool) is a verification system for checking safety properties of C programs using automatic property-driven construction and model checking of software abstractions. Blast implements an abstract-model check-refine loop to check for reachability of a specified label in the program. The abstract model is built on the fly using predicate abstraction. This model is then checked for reachability. If there is no (abstract) path to the specified error label, Blast reports that the system is safe and produces a succinct proof. Otherwise, it checks if the path is feasible using symbolic execution of the program. If the path is feasible, Blast outputs the path as an error trace, otherwise, it uses the infeasibility of the path to refine the abstract model. Blast short-circuits the loop from abstraction to verification to refinement, integrating the three steps tightly through “lazy abstraction” [5]. This integration can offer significant advantages in performance by avoiding the repetition of work from one iteration of the loop to the next. },
author = {Thomas Henzinger and Jhala, Ranjit and Majumdar, Ritankar S and Sutre, Grégoire},
pages = {235 -- 239},
publisher = {Springer},
title = {{Software verification with BLAST}},
doi = {10.1007/3-540-44829-2_17},
volume = {2648},
year = {2003},
}
@article{4468,
abstract = {Giotto is a high-level programming language for time-triggered control applications. The authors begin with a conceptual overview of its methodology, discuss the Giotto helicopter project, and summarize available Giotto implementations.},
author = {Thomas Henzinger and Kirsch, Christoph M and Sanvido, Marco A and Pree, Wolfgang},
journal = {IEEE Control Systems Magazine},
number = {1},
pages = {50 -- 64},
publisher = {IEEE},
title = {{From control models to real-time code using Giotto}},
doi = {10.1109/MCS.2003.1172829},
volume = {23},
year = {2003},
}
@article{4469,
abstract = {Giotto provides an abstract programmer's model for the implementation of embedded control systems with hard real-time constraints. A typical control application consists of periodic software tasks together with a mode-switching logic for enabling and disabling tasks. Giotto specifies time-triggered sensor readings, task invocations, actuator updates, and mode switches independent of any implementation platform. Giotto can be annotated with platform constraints such as task-to-host mappings, and task and communication schedules. The annotations are directives for the Giotto compiler, but they do not alter the functionality and timing of a Giotto program. By separating the platform-independent from the platform-dependent concerns, Giotto enables a great deal of flexibility in choosing control platforms as well as a great deal of automation in the validation and synthesis of control software. The time-triggered nature of Giotto achieves timing predictability, which makes Giotto particularly suitable for safety-critical applications.},
author = {Thomas Henzinger and Horowitz, Benjamin and Kirsch, Christoph M},
journal = {Proceedings of the IEEE},
number = {1},
pages = {84 -- 99},
publisher = {IEEE},
title = {{Giotto: A time-triggered language for embedded programming}},
doi = {10.1109/JPROC.2002.805825},
volume = {91},
year = {2003},
}
@inproceedings{4561,
abstract = {We present a formalism for specifying component interfaces that expose component requirements on limited resources. The formalism permits an algorithmic check if two or more components, when put together, exceed the available resources. Moreover, the formalism can be used to compute the quantity of resources necessary for satisfying the requirements of a collection of components. The formalism can be instantiated in several ways. For example, several components may draw power from the same source. Then, the formalism supports compatibility checks such as: can two components, when put together, achieve their tasks without ever exceeding the available amount of peak power? or, can they achieve their tasks by using no more than the initially available amount of energy (i.e., power accumulated over time)? The corresponding quantitative questions that our algorithms answer are the following: what is the amount of peak power needed for two components to be put together? what is the corresponding amount of initial energy? To solve these questions, we model interfaces with resource requirements as games with quantitative objectives. The games are played on state spaces where each state is labeled by a number (representing, e.g., power consumption), and a play produces an infinite path of labels. The objective may be, for example, to minimize the largest label that occurs during a play. We illustrate our approach by modeling compatibility questions for the components of robot control software, and of wireless sensor networks.},
author = {Chakrabarti, Arindam and de Alfaro, Luca and Thomas Henzinger and Stoelinga, Mariëlle},
pages = {117 -- 133},
publisher = {ACM},
title = {{Resource interfaces}},
doi = {10.1007/978-3-540-45212-6_9},
volume = {2855},
year = {2003},
}
@article{2990,
abstract = {Plant growth is marked by its adaptability to continuous changes in environment. A regulated, differential distribution of auxin underlies many adaptation processes including organogenesis, meristem patterning and tropisms. In executing its multiple roles, auxin displays some characteristics of both a hormone and a morphogen. Studies on auxin transport, as well as tracing the intracellular movement of its molecular components, have suggested a possible scenario to explain how growth plasticity is conferred at the cellular and molecular level. The plant perceives stimuli and changes the subcellular position of auxin-transport components accordingly. These changes modulate auxin fluxes, and the newly established auxin distribution triggers the corresponding developmental response.},
author = {Friml, Jirí},
journal = {Current Opinion in Plant Biology},
number = {1},
pages = {7 -- 12},
publisher = {Elsevier},
title = {{Auxin transport - Shaping the plant}},
doi = {10.1016/S1369526602000031},
volume = {6},
year = {2003},
}
@article{2992,
abstract = {Plants have many polarized cell types, but relatively little is known about the mechanisms that establish polarity. The orc mutant was identified originally by defects in root patterning, and positional cloning revealed that the affected gene encodes STEROL METHYLTRANSFERASE1, which is required for the appropriate synthesis and composition of major membrane sterols. smt1orc mutants displayed several conspicuous cell polarity defects. Columella root cap cells revealed perturbed polar positioning of different organelles, and in the smt1orc root epidermis, polar initiation of root hairs was more randomized. Polar auxin transport and expression of the auxin reporter DR5-β-glucuronidase were aberrant in smt1orc. Patterning defects in smt1orc resembled those observed in mutants of the PIN gene family of putative auxin efflux transporters. Consistently, the membrane localization of the PIN1 and PIN3 proteins was disturbed in smt1orc, whereas polar positioning of the influx carrier AUX1 appeared normal. Our results suggest that balanced sterol composition is a major requirement for cell polarity and auxin efflux in Arabidopsis.},
author = {Willemsen, Viola and Jirí Friml and Grebe, Markus and Van Den Toorn, Albert and Palme, Klaus and Scheres, Ben},
journal = {Plant Cell},
number = {3},
pages = {612 -- 625},
publisher = {American Society of Plant Biologists},
title = {{Cell polarity and PIN protein positioning in Arabidopsis require STEROL METHYLTRANSFERASE1 function}},
doi = {10.1105/tpc.008433},
volume = {15},
year = {2003},
}
@article{2993,
abstract = {Plant biology is currently experiencing a growing demand for easy and reliable mRNA and protein localisation techniques. Here, we present novel whole mount in situ hybridisation and immunolocalisation protocols, suitable to localise mRNAs and proteins in Arabidopsis seedlings. We demonstrate that these methods can be used in different organs of Arabidopsis seedlings as well as in other plant species. In order to achieve better reproducibility and higher throughput, we modified these protocols for automation to be performed by a liquid handling robot. In addition, we show that other procedures such as reporter enzyme assays and tissue clearing can be similarly automated. We present examples of application of our protocols including mRNA localisation and proteins and epitope tag (co)localisations which demonstrate that these methods provide reliable and versatile tools for expression, localisation and anatomical studies in plants.},
author = {Jirí Friml and Eva Benková and Mayer, Ulrike and Palme, Klaus and Muster, Gerhard},
journal = {Plant Journal},
number = {1},
pages = {115 -- 124},
publisher = {Wiley-Blackwell},
title = {{Automated whole mount localisation techniques for plant seedlings}},
doi = {10.1046/j.1365-313X.2003.01705.x},
volume = {34},
year = {2003},
}
@article{2994,
abstract = {The regular arrangement of leaves around a plant's stem, called phyllotaxis, has for centuries attracted the attention of philosophers, mathematicians and natural scientists; however, to date, studies of phyllotaxis have been largely theoretical. Leaves and flowers are formed from the shoot apical meristem, triggered by the plant hormone auxin. Auxin is transported through plant tissues by specific cellular influx and efflux carrier proteins. Here we show that proteins involved in auxin transport regulate phyllotaxis. Our data indicate that auxin is transported upwards into the meristem through the epidermis and the outermost meristem cell layer. Existing leaf primordia act as sinks, redistributing auxin and creating its heterogeneous distribution in the meristem. Auxin accumulation occurs only at certain minimal distances from existing primordia, defining the position of future primordia. This model for phyllotaxis accounts for its reiterative nature, as well as its regularity and stability.},
author = {Reinhardt, Didier and Pesce, Eva-Rachele and Stieger, Pia and Mandel, Therese and Baltensperger, Kurt and Bennett, Malcolm and Traas, Jan and Jirí Friml and Kuhlemeier, Cris},
journal = {Nature},
number = {6964},
pages = {255 -- 260},
publisher = {Nature Publishing Group},
title = {{Regulation of phyllotaxis by polar auxin transport}},
doi = {10.1038/nature02081},
volume = {426},
year = {2003},
}
@article{2995,
abstract = {Axis formation occurs in plants, as in animals, during early embryogenesis. However, the underlying mechanism is not known. Here we show that the first manifestation of the apical-basal axis in plants, the asymmetric division of the zygote, produces a basal cell that transports and an apical cell that responds to the signalling molecule auxin. This apical-basal auxin activity gradient triggers the specification of apical embryo structures and is actively maintained by a novel component of auxin efflux, PIN7, which is located apically in the basal cell. Later, the developmentally regulated reversal of PIN7 and onset of PIN1 polar localization reorganize the auxin gradient for specification of the basal root pole. An analysis of pin quadruple mutants identifies PIN-dependent transport as an essential part of the mechanism for embryo axis formation. Our results indicate how the establishment of cell polarity, polar auxin efflux and local auxin response result in apical-basal axis formation of the embryo, and thus determine the axiality of the adult plant.
},
author = {Jirí Friml and Vieten, Anne and Sauer, Michael and Weijers, Dolf and Schwarz, Heinz and Hamann, Thorsten and Offringa, Remko and Jürgens, Gerd},
journal = {Nature},
number = {6963},
pages = {147 -- 153},
publisher = {Nature Publishing Group},
title = {{Efflux dependent auxin gradients establish the apical basal axis of Arabidopsis}},
doi = {10.1038/nature02085},
volume = {426},
year = {2003},
}
@article{2996,
abstract = {Plants, compared to animals, exhibit an amazing adaptability and plasticity in their development. This is largely dependent on the ability of plants to form new organs, such as lateral roots, leaves, and flowers during postembryonic development. Organ primordia develop from founder cell populations into organs by coordinated cell division and differentiation. Here, we show that organ formation in Arabidopsis involves dynamic gradients of the signaling molecule auxin with maxima at the primordia tips. These gradients are mediated by cellular efflux requiring asymmetrically localized PIN proteins, which represent a functionally redundant network for auxin distribution in both aerial and underground organs. PIN1 polar localization undergoes a dynamic rearrangement, which correlates with establishment of auxin gradients and primordium development. Our results suggest that PIN-dependent, local auxin gradients represent a common module for formation of all plant organs, regardless of their mature morphology or developmental origin.
},
author = {Eva Benková and Michniewicz, Marta and Sauer, Michael and Teichmann, Thomas and Seifertová, Daniela and Jürgens, Gerd and Jirí Friml},
journal = {Cell},
number = {5},
pages = {591 -- 602},
publisher = {Cell Press},
title = {{Local, efflux-dependent auxin gradients as a common module for plant organ formation}},
doi = {10.1016/S0092-8674(03)00924-3},
volume = {115},
year = {2003},
}
@misc{3139,
abstract = {Significant advances have been made during the past few years in our understanding of how the spinal monosynaptic reflex develops. Transcription factors in the Neurogenin, Runt, ETS, and LIM families control sequential steps of the specification of various subtypes of dorsal root ganglia sensory neurons. The initiation of muscle spindle differentiation requires neuregulin 1, derived from Ia afferent sensory neurons, and signaling through ErbB receptors in intrafusal muscle fibers. Several retrograde signals from the periphery are important for the establishment of late connectivity in the reflex circuit. Finally, neurotrophin 3 released from muscle spindles regulates the strength of sensory-motor connections within the spinal cord postnatally.},
author = {Chen, Hsiao Huei and Simon Hippenmeyer and Arber, Silvia and Frank, Eric},
booktitle = {Current Opinion in Neurobiology},
number = {1},
pages = {96 -- 102},
publisher = {Elsevier},
title = {{Development of the monosynaptic stretch reflex circuit}},
doi = {10.1016/S0959-4388(03)00006-0},
volume = {13},
year = {2003},
}
@article{3150,
abstract = {Tripartite G-protein-coupled receptors (GPCRs) represent one of the largest groups of signal transducers, transmitting signals from hormones, neuropeptides, odorants, food and light. Ligand-bound receptors catalyse GDP/GTP exchange on the G-protein α-subunit (Gα), leading to α-GTP separation from the βγ subunits and pathway activation. Activating mutations in the receptors or G proteins underlie many human diseases, including some cancers, dwarfism and premature puberty. Regulators of G-protein signalling (RGS proteins) are known to modulate the level and duration of ligand-induced signalling by accelerating the intrinsic GTPase activity of the Gα subunit, and thus reformation of the inactive GDP-bound Gα. Here we find that even in the absence of receptor, mutation of the RGS family member Sst2 (refs 6-9) permits spontaneous activation of the G-protein-coupled mating pathway in Saccharomyces cerevisiae at levels normally seen only in the presence of ligand. Our work demonstrates the occurence of spontaneous tripartite G-protein signalling in vivo and identifies a requirement for RGS proteins in preventing such receptor-independent activation.},
author = {Daria Siekhaus and Drubin, David G},
journal = {Nature Cell Biology},
number = {3},
pages = {231 -- 235},
publisher = {Nature Publishing Group},
title = {{Spontaneous receptor-independent heterotrimeric G-protein signalling in an RGS mutant}},
doi = {10.1038/ncb941},
volume = {5},
year = {2003},
}
@article{3151,
abstract = {Biosynthesis of most peptide hormones and neuropeptides requires proteolytic excision of the active peptide from inactive proprotein precursors, an activity carried out by subtilisin-like proprotein convertases (SPCs) in constitutive or regulated secretory pathways. The Drosophila amontillado (amon) gene encodes a homolog of the mammalian PC2 protein, an SPC that functions in the regulated secretory pathway in neuroendocrine tissues. We have identified amon mutants by isolating ethylmethanesulfonate (EMS)-induced lethal and visible mutations that define two complementation groups in the amon interval at 97D1 of the third chromosome. DNA sequencing identified the amon complementation group and the DNA sequence change for each of the nine amon alleles isolated. amon mutants display partial embryonic lethality, are defective in larval growth, and arrest during the first to second instar larval molt. Mutant larvae can be rescued by heat-shock-induced expression of the amon protein. Rescued larvae arrest at the subsequent larval molt, suggesting that amon is also required for the second to third instar larval molt. Our data indicate that the amon proprotein convertase is required during embryogenesis and larval development in Drosophila and support the hypothesis that AMON acts to proteolytically process peptide hormones that regulate hatching, larval growth, and larval ecdysis.},
author = {Rayburn, Lowell Y and Gooding, Holly C and Choksi, Semil P and Maloney, Dhea and Kidd, Ambrose R and Daria Siekhaus and Bender, Michael},
journal = {Genetics},
number = {1},
pages = {227 -- 237},
publisher = {Genetics Society of America},
title = {{Amontillado, the Drosophila homolog of the prohormone processing protease PC2, is required during embryogenesis and early larval development}},
volume = {163},
year = {2003},
}
@inproceedings{3170,
abstract = {Geodesic active contours and graph cuts are two standard image segmentation techniques. We introduce a new segmentation method combining some of their benefits. Our main intuition is that any cut on a graph embedded in some continuous space can be interpreted as a contour (in 2D) or a surface (in 3D). We show how to build a grid graph and set its edge weights so that the cost of cuts is arbitrarily close to the length (area) of the corresponding contours (surfaces) for any anisotropic Riemannian metric. There are two interesting consequences of this technical result. First, graph cut algorithms can be used to find globally minimum geodesic contours (minimal surfaces in 3D) under arbitrary Riemannian metric for a given set of boundary conditions. Second, we show how to minimize metrication artifacts in existing graph-cut based methods in vision. Theoretically speaking, our work provides an interesting link between several branches of mathematics -differential geometry, integral geometry, and combinatorial optimization. The main technical problem is solved using Cauchy-Crofton formula from integral geometry.},
author = {Boykov, Yuri and Vladimir Kolmogorov},
pages = {26 -- 33},
publisher = {IEEE},
title = {{Computing geodesics and minimal surfaces via graph cuts}},
doi = {10.1109/ICCV.2003.1238310},
volume = {1},
year = {2003},
}
@inproceedings{3171,
abstract = {Reconstructing a 3-D scene from more than one camera is a classical problem in computer vision. One of the major sources of difficulty is the fact that not all scene elements are visible from all cameras. In the last few years, two promising approaches have been developed 11,12 that formulate the scene reconstruction problem in terms of energy minimization, and minimize the energy using graph cuts. These energy minimization approaches treat the input images symmetrically, handle visibility constraints correctly, and allow spatial smoothness to be enforced. However, these algorithm propose different problem formulations, and handle a limited class of smoothness terms. One algorithm 11 uses a problem formulation that is restricted to two-camera stereo, and imposes smoothness between a pair of cameras. The other algorithm 12 can handle an arbitrary number of cameras, but imposes smoothness only with respect to a single camera. In this paper we give a more general energy minimization formulation for the problem, which allows a larger class of spatial smoothness constraints. We show that our formulation includes both of the previous approaches as special cases, as well as permitting new energy functions. Experimental results on real data with ground truth are also included. },
author = {Vladimir Kolmogorov and Zabih, Ramin and Gortler, Steven},
pages = {501 -- 516},
publisher = {Springer},
title = {{Generalized multi camera scene reconstruction using graph cuts}},
doi = {10.1007/978-3-540-45063-4_32},
volume = {2683},
year = {2003},
}
@inproceedings{3174,
abstract = {We address visual correspondence problems without assuming that scene points have similar intensities in different views. This situation is common, usually due to non-lambertian scenes or to differences between cameras. We use maximization of mutual information, a powerful technique for registering images that requires no a priori model of the relationship between scene intensities in different views. However, it has proven difficult to use mutual information to compute dense visual correspondence. Comparing fixed-size windows via mutual information suffers from the well-known problems of fixed windows, namely poor performance at discontinuities and in low-texture regions. In this paper, we show how to compute visual correspondence using mutual information without suffering from these problems. Using 'a simple approximation, mutual information can be incorporated into the standard energy minimization framework used in early vision. The energy can then be efficiently minimized using graph cuts, which preserve discontinuities and handle low-texture regions. The resulting algorithm combines the accurate disparity maps that come from graph cuts with the tolerance for intensity changes that comes from mutual information.},
author = {Kim, Junhwan and Vladimir Kolmogorov and Zabih, Ramin},
pages = {1033 -- 1040},
publisher = {IEEE},
title = {{Visual correspondence using energy minimization and mutual information}},
doi = {10.1109/ICCV.2003.1238463},
volume = {2},
year = {2003},
}
@article{3209,
abstract = {We show that the fixed alphabet shortest common supersequence (SCS) and the fixed alphabet longest common subsequence (LCS) problems parameterized in the number of strings are W[1]-hard. Unless W[1]=FPT, this rules out the existence of algorithms with time complexity of O(f(k)nα) for those problems. Here n is the size of the problem instance, α is constant, k is the number of strings and f is any function of k. The fixed alphabet version of the LCS problem is of particular interest considering the importance of sequence comparison (e.g. multiple sequence alignment) in the fixed length alphabet world of DNA and protein sequences.},
author = {Krzysztof Pietrzak},
journal = {Journal of Computer and System Sciences},
number = {4},
pages = {757 -- 771},
publisher = {Elsevier},
title = {{On the parameterized complexity of the fixed alphabet shortest common supersequence and longest common subsequence problems}},
doi = {10.1016/S0022-0000(03)00078-3},
volume = {67},
year = {2003},
}
@inproceedings{3210,
abstract = {Luby and Rackoff showed how to construct a (super-)pseudo-random permutation {0,1}2n→ {0,1}2n from some number r of pseudo-random functions {0,1}n → {0,1}n. Their construction, motivated by DES, consists of a cascade of r Feistel permutations. A Feistel permutation 1for a pseudo-random function f is defined as (L, R) → (R,L ⊕ f (R)), where L and R are the left and right part of the input and ⊕ denotes bitwise XOR or, in this paper, any other group operation on {0,1}n. The only non-trivial step of the security proof consists of proving that the cascade of r Feistel permutations with independent uniform random functions {0,1}n → {0,1}n, denoted Ψ2nr is indistinguishable from a uniform random permutation {0,1}2n → {0,1}2n by any computationally unbounded adaptive distinguisher making at most O(2cn) combined chosen plaintext/ciphertext queries for any c < α, where a is a security parameter. Luby and Rackoff proved α = 1/2 for r = 4. A natural problem, proposed by Pieprzyk is to improve on α for larger r. The best known result, α = 3/4 for r = 6, is due to Patarin. In this paper we prove a = 1 -O(1/r), i.e., the trivial upper bound α = 1 can be approached. The proof uses some new techniques that can be of independent interest. },
author = {Maurer, Ueli M and Krzysztof Pietrzak},
pages = {544 -- 561},
publisher = {Springer},
title = {{The security of many round Luby Rackoff pseudo random permutations}},
doi = {10.1007/3-540-39200-9_34},
volume = {2656},
year = {2003},
}
@inproceedings{3425,
author = {Bollenbach, Mark Tobias and Strother, T. and Bauer, Wolfgang},
pages = {277 -- 288},
publisher = {Springer},
title = {{3D supernova collapse calculations}},
doi = {10.1007/978-1-4020-2705-5_21},
volume = {166},
year = {2003},
}
@inbook{3458,
author = {Peter Jonas and Unsicker, Klaus},
booktitle = {Lehrbuch Vorklinik},
editor = {Schmidt, R. F.},
pages = {3 -- 26},
publisher = {Deutscher Ärzte Verlag},
title = {{Molekulare und zelluläre Grundlagen des Nervensystems.}},
volume = {B},
year = {2003},
}
@article{3526,
abstract = {Neurons can produce action potentials with high temporal precision(1). A fundamental issue is whether, and how, this capability is used in information processing. According to the `cell assembly' hypothesis, transient synchrony of anatomically distributed groups of neurons underlies processing of both external sensory input and internal cognitive mechanisms(2-4). Accordingly, neuron populations should be arranged into groups whose synchrony exceeds that predicted by common modulation by sensory input. Here we find that the spike times of hippocampal pyramidal cells can be predicted more accurately by using the spike times of simultaneously recorded neurons in addition to the animals location in space. This improvement remained when the spatial prediction was refined with a spatially dependent theta phase modulation(5-8). The time window in which spike times are best predicted from simultaneous peer activity is 10-30 ms, suggesting that cell assemblies are synchronized at this timescale. Because this temporal window matches the membrane time constant of pyramidal neurons(9), the period of the hippocampal gamma oscillation(10) and the time window for synaptic plasticity(11), we propose that cooperative activity at this timescale is optimal for information transmission and storage in cortical circuits.},
author = {Harris, Kenneth D and Jozsef Csicsvari and Hirase, Hajima and Dragoi, George and Buzsáki, György},
journal = {Nature},
number = {6948},
pages = {552 -- 556},
publisher = {Nature Publishing Group},
title = {{Organization of cell assemblies in the hippocampus}},
doi = {0.1038/nature01834},
volume = {424},
year = {2003},
}
@article{3528,
abstract = {Gamma frequency oscillations (30-100 Hz) have been suggested to underlie various cognitive and motor functions. Here, we examine the generation of gamma oscillation currents in the hippocampus, using two-dimensional, 96-site silicon probes. Two gamma generators were identified, one in the dentate gyrus and another in the CA3-CA1 regions. The coupling strength between the two oscillators varied during both theta and nontheta states. Both pyramidal cells and interneurons were phase-locked to gamma waves. Anatomical connectivity, rather than physical distance, determined the coupling strength of the oscillating neurons. CA3 pyramidal neurons discharged CA3 and CA1 interneurons at latencies indicative of monosynaptic connections. Intrahippocampal gamma oscillation emerges in the CA3 recurrent system, which entrains the CA1 region via its interneurons.},
author = {Jozsef Csicsvari and Jamieson, Brian G and Wise, Kensall D and Buzsáki, György},
journal = {Neuron},
number = {2},
pages = {311 -- 322},
publisher = {Elsevier},
title = {{Mechanisms of gamma oscillations in the hippocampus of the behaving rat}},
doi = {10.1016/S0896-6273(02)01169-8},
volume = {37},
year = {2003},
}
@article{3529,
abstract = {Parallel recording of neuronal activity in the behaving animal is a prerequisite for our understanding of neuronal representation and storage of information. Here we describe the development of micro-machined silicon microelectrode arrays for unit and local field recordings. The two-dimensional probes with 96 or 64 recording sites provided high-density recording of unit and field activity with minimal tissue displacement or damage. The on-chip active circuit eliminated movement and other artifacts and greatly reduced the weight of the headgear. The precise geometry of the recording tips allowed for the estimation of the spatial location of the recorded neurons and for high-resolution estimation of extracellular current source density. Action potentials could be simultaneously recorded from the soma and dendrites of the same neurons. Silicon technology is a promising approach for high-density, high-resolution sampling of neuronal activity in both basic research and prosthetic devices.},
author = {Jozsef Csicsvari and Henze, Darrell A and Jamieson, Brian G and Harris, Kenneth D and Sirota, Anton M and Bartho, Peter and Wise, Kensall D and Buzsáki, György},
journal = {Journal of Neurophysiology},
number = {2},
pages = {1314 -- 1323},
publisher = {American Physiological Society},
title = {{Massively parallel recording of unit and local field potentials with silicon-based electrodes}},
doi = {10.1152/jn.00116.2003},
volume = {90},
year = {2003},
}
@article{3536,
abstract = {Genetic engineering of the mouse brain allows investigators to address novel hypotheses in vivo. Because of the paucity of information on the network patterns of the mouse hippocampus, we investigated the electrical patterns in the behaving animal using multisite silicon probes and wire tetrodes. Theta (6-9 Hz) and gamma (40-100 Hz) oscillations were present during exploration and rapid eye movement sleep. Gamma power and theta power were comodulated and gamma power varied as a function of the theta cycle. Pyramidal cells and putative interneurons were phase-locked to theta oscillations. During immobility, consummatory behaviors and slow-wave sleep, sharp waves were present in cornu ammonis region CA1 of the hippocampus stratum radiatum associated with 140-200-Hz “ripples” in the pyramidal cell layer and population burst of CA1 neurons. In the hilus, large-amplitude “dentate spikes” occurred in association with increased discharge of hilar neurons. The amplitude of field patterns was larger in the mouse than in the rat, likely reflecting the higher neuron density in a smaller brain. We suggest that the main hippocampal network patterns are mediated by similar pathways and mechanisms in mouse and rat. },
author = {Buzsáki, György and Buhl, Derek L and Harris, Kenneth D and Jozsef Csicsvari and Czéh, Boldizsár and Morozov, Alexei},
journal = {Neuroscience},
number = {1},
pages = {201 -- 211},
publisher = {Elsevier},
title = {{Hippocampal network patterns of activity in the mouse}},
doi = {10.1016/S0306-4522(02)00669-3},
volume = {116},
year = {2003},
}
@article{3543,
abstract = {Both neocortical and hippocampal networks organize the firing patterns of their neurons by prominent oscillations during sleep, but the functional role of these rhythms is not well understood. Here, we show a robust correlation of neuronal discharges between the somatosensory cortex and hippocampus on both slow and fine time scales in the mouse and rat. Neuronal bursts in deep cortical layers, associated with sleep spindles and delta waves/slow rhythm, effectively triggered hippocampal discharges related to fast (ripple) oscillations. We hypothesize that oscillation-mediated temporal links coordinate specific information transfer between neocortical and hippocampal cell assemblies. Such a neocortical-hippocampal interplay may be important for memory consolidation.},
author = {Sirota, Anton M and Jozsef Csicsvari and Buhl, Derek L and Buzsáki, György},
journal = {PNAS},
number = {4},
pages = {2065 -- 2069},
publisher = {National Academy of Sciences},
title = {{Communication between neocortex and hippocampus during sleep in rodents}},
doi = {10.1073/pnas.0437938100},
volume = {100},
year = {2003},
}
@inproceedings{3556,
abstract = {We define the Morse-Smale complex of a Morse function over a 3-manifold as the overlay of the descending and as- cending manifolds of all critical points. In the generic case, its 3-dimensional cells are shaped like crystals and are sepa- rated by quadrangular faces. In this paper, we give a combi- natorial algorithm for constructing such complexes for piece- wise linear data.},
author = {Herbert Edelsbrunner and Harer, John and Natarajan, Vijay and Pascucci, Valerio},
pages = {361 -- 370},
publisher = {ACM},
title = {{Morse-Smale complexes for piecewise linear 3-manifolds}},
doi = {10.1145/777792.777846},
year = {2003},
}
@inbook{3573,
abstract = {Given a finite point set in R, the surface reconstruction problem asks for a surface that passes through many but not necessarily all points. We describe an unambigu- ous definition of such a surface in geometric and topological terms, and sketch a fast algorithm for constructing it. Our solution overcomes past limitations to special point distributions and heuristic design decisions.},
author = {Herbert Edelsbrunner},
booktitle = {Discrete & Computational Geometry},
pages = {379 -- 404},
publisher = {Springer},
title = {{Surface reconstruction by wrapping finite sets in space}},
doi = {10.1007/978-3-642-55566-4_17},
year = {2003},
}
@article{3584,
abstract = {We develop fast algorithms for computing the linking number of a simplicial complex within a filtration.We give experimental results in applying our work toward the detection of non-trivial tangling in biomolecules, modeled as alpha complexes.},
author = {Edelsbrunner, Herbert and Zomorodian, Afra},
journal = {Homology, Homotopy and Applications},
number = {2},
pages = {19 -- 37},
publisher = {International Press},
title = {{Computing linking numbers of a filtration}},
volume = {5},
year = {2003},
}
@article{3593,
abstract = {Temporal logics such as Computation Tree Logic (CTL) and Linear Temporal Logic (LTL) have become popular for specifying temporal properties over a wide variety of planning and verification problems. In this paper we work towards building a generalized framework for automated reasoning based on temporal logics. We present a powerful extension of CTL with first-order quantification over the set of reachable states for reasoning about extremal properties of weighted labeled transition systems in general. The proposed logic, which we call Weighted Quantified Computation Tree Logic (WQCTL), captures the essential elements common to the domain of planning and verification problems and can thereby be used as an effective specification language in both domains. We show that in spite of the rich, expressive power of the logic, we are able to evaluate WQCTL formulas in time polynomial in the size of the state space times the length of the formula. Wepresent experimental results on the WQCTL verifier.},
author = {Krishnendu Chatterjee and Dasgupta, Pallab and Chakrabarti, Partha P},
journal = {Journal of Automated Reasoning},
number = {2},
pages = {205 -- 232},
publisher = {Springer},
title = {{A branching time temporal framework for quantitative reasoning}},
doi = {10.1023/A:1023217515688},
volume = {30},
year = {2003},
}
@article{3618,
abstract = {There are several analyses in evolutionary ecology which assume that a family of offspring has come from only two parents. Here, we present a simple test for detecting when a batch involves two or more subfamilies. It is based on the fact that the mixing of families generates associations amongst unlinked marker loci. We also present simulations illustrating the power of our method for varying numbers of loci, alleles per locus and genotyped individuals.},
author = {Vines, Timothy H and Nicholas Barton},
journal = {Molecular Ecology},
number = {7},
pages = {1999 -- 2002},
publisher = {Wiley-Blackwell},
title = {{A new approach to detecting mixed families}},
doi = {10.1046/j.1365-294X.2003.01867.x},
volume = {12},
year = {2003},
}
@article{3619,
abstract = {What is the chance that some part of a stretch of genome will survive? In a population of constant size, and with no selection, the probability of survival of some part of a stretch of map length y<1 approaches View the MathML source for View the MathML source. Thus, the whole genome is certain to be lost, but the rate of loss is extremely slow. This solution extends to give the whole distribution of surviving block sizes as a function of time. We show that the expected number of blocks at time t is 1+yt and give expressions for the moments of the number of blocks and the total amount of genome that survives for a given time. The solution is based on a branching process and assumes complete interference between crossovers, so that each descendant carries only a single block of ancestral material. We consider cases where most individuals carry multiple blocks, either because there are multiple crossovers in a long genetic map, or because enough time has passed that most individuals in the population are related to each other. For species such as ours, which have a long genetic map, the genome of any individual which leaves descendants (∼80% of the population for a Poisson offspring number with mean two) is likely to persist for an extremely long time, in the form of a few short blocks of genome.},
author = {Baird, Stuart J and Nicholas Barton and Etheridge, Alison M},
journal = {Theoretical Population Biology},
number = {4},
pages = {451 -- 471},
publisher = {Academic Press},
title = {{The distribution of surviving blocks of an ancestral genome}},
doi = {10.1016/S0040-5809(03)00098-4},
volume = {64},
year = {2003},
}
@article{3620,
abstract = {Stable hybrid zones in which ecologically divergent taxa give rise to a range of recombinants are natural laboratories in which the genetic basis of adaptation and reproductive isolation can be unraveled. One such hybrid zone is formed by the fire-bellied toads Bombina bombina and B. variegata (Anura: Discoglossidae). Adaptations to permanent and ephemeral breeding habitats, respectively, have shaped numerous phenotypic differences between the taxa. All of these are, in principle, candidates for a genetic dissection via QTL mapping. We present here a linkage map of 28 codominant and 10 dominant markers in the Bombina genome. In an F2 cross, markers that were mainly microsatellites, SSCPs or allozymes were mapped to 20 linkage groups. Among the 40 isolated CA microsatellites, we noted a preponderance of compound and frequently interleaved CA-TA repeats as well as a striking polarity at the 5′ end of the repeats.},
author = {Nürnberger, Beate and Hofman, Sebastian and Förg-Brey, Bqruni and Praetzel, Gabriele and Maclean, Alan W and Szymura, Jacek M and Abbott, Catherine M and Nicholas Barton},
journal = {Heredity},
number = {2},
pages = {136 -- 142},
publisher = {Nature Publishing Group},
title = {{A linkage map for the hybridising toads Bombina bombina and B. variegata (Anura: Discoglossidae)}},
doi = {10.1038/sj.hdy.6800291},
volume = {91},
year = {2003},
}
@phdthesis{3678,
author = {Christoph Lampert},
booktitle = {Bonner Mathematische Schriften},
pages = {1 -- 165},
publisher = {Universität Bonn, Fachbibliothek Mathematik},
title = {{The Neumann operator in strictly pseudoconvex domains with weighted Bergman metric }},
volume = {356},
year = {2003},
}
@article{9455,
abstract = {Proteins of the ARGONAUTE family are important in diverse posttranscriptional RNA-mediated gene-silencing systems as well as in transcriptional gene silencing in Drosophila and fission yeast and in programmed DNA elimination in Tetrahymena. We cloned ARGONAUTE4 (AGO4) from a screen for mutants that suppress silencing of the Arabidopsis SUPERMAN(SUP) gene. The ago4-1 mutant reactivated silentSUP alleles and decreased CpNpG and asymmetric DNA methylation as well as histone H3 lysine-9 methylation. In addition,ago4-1 blocked histone and DNA methylation and the accumulation of 25-nucleotide small interfering RNAs (siRNAs) that correspond to the retroelement AtSN1. These results suggest that AGO4 and long siRNAs direct chromatin modifications, including histone methylation and non-CpG DNA methylation.},
author = {ZILBERMAN, Daniel and Cao, Xiaofeng and Jacobsen, Steven E.},
issn = {1095-9203},
journal = {Science},
keywords = {Multidisciplinary},
number = {5607},
pages = {716--719},
publisher = {American Association for the Advancement of Science},
title = {{ARGONAUTE4 control of locus-specific siRNA accumulation and DNA and histone methylation}},
doi = {10.1126/science.1079695},
volume = {299},
year = {2003},
}
@article{9495,
abstract = {RNA interference is a conserved process in which double-stranded RNA is processed into 21–25 nucleotide siRNAs that trigger posttranscriptional gene silencing. In addition, plants display a phenomenon termed RNA-directed DNA methylation (RdDM) in which DNA with sequence identity to silenced RNA is de novo methylated at its cytosine residues. This methylation is not only at canonical CpG sites but also at cytosines in CpNpG and asymmetric sequence contexts. In this report, we study the role of the DRM and CMT3 DNA methyltransferase genes in the initiation and maintenance of RdDM. Neither drm nor cmt3 mutants affected the maintenance of preestablished RNA-directed CpG methylation. However, drm mutants showed a nearly complete loss of asymmetric methylation and a partial loss of CpNpG methylation. The remaining asymmetric and CpNpG methylation was dependent on the activity of CMT3, showing that DRM and CMT3 act redundantly to maintain non-CpG methylation. These DNA methyltransferases appear to act downstream of siRNAs, since drm1 drm2 cmt3 triple mutants show a lack of non-CpG methylation but elevated levels of siRNAs. Finally, we demonstrate that DRM activity is required for the initial establishment of RdDM in all sequence contexts including CpG, CpNpG, and asymmetric sites.},
author = {Cao, Xiaofeng and Aufsatz, Werner and ZILBERMAN, Daniel and Mette, M.Florian and Huang, Michael S. and Matzke, Marjori and Jacobsen, Steven E.},
issn = {1879-0445},
journal = {Current Biology},
number = {24},
pages = {2212--2217},
publisher = {Elsevier},
title = {{Role of the DRM and CMT3 methyltransferases in RNA-directed DNA methylation}},
doi = {10.1016/j.cub.2003.11.052},
volume = {13},
year = {2003},
}
@inbook{2338,
author = {Lieb, Élliott H and Solovej, Jan P and Robert Seiringer and Yngvason, Jakob},
booktitle = {Current Developments in Mathematics, 2001},
pages = {131 -- 178},
publisher = {International Press},
title = {{The ground state of the Bose gas}},
doi = {http://arxiv.org/abs/math-ph/0204027},
year = {2002},
}
@inproceedings{2339,
author = {Robert Seiringer},
editor = {Weder, Richardo and Exner, Pavel and Grébert, Benoit},
pages = {281 -- 286},
publisher = {World Scientific Publishing},
title = {{Symmetry breaking in a model of a rotating Bose gas}},
doi = {10.1090/conm/307},
volume = {307},
year = {2002},
}
@article{2349,
abstract = {The Bose-Einstein condensation (BEC) of the ground state of bosonic atoms in a trap was discussed. The BEC was proved for bosons with two-body repulsive interaction potentials in the dilute limit, starting from the basic Schrodinger equation. The BEC was 100% into the state which minimized the Gross-Pitaevskii energy functional. The analysis also included rigorous proof of BEC in a physically realistic, continuum model.},
author = {Lieb, Élliott H and Robert Seiringer},
journal = {Physical Review Letters},
number = {17},
pages = {1704091 -- 1704094},
publisher = {American Physical Society},
title = {{Proof of Bose-Einstein condensation for dilute trapped gases}},
doi = {10.1103/PhysRevLett.88.170409},
volume = {88},
year = {2002},
}
@article{2350,
abstract = {Using the Pauli-Fierz model of non-relativistic quantum electrodynamics, we calculate the binding energy of an electron in the field of a nucleus of charge Z and in presence of the quantized radiation field. We consider the case of small coupling constant α, but fixed Zα and ultraviolet cut-off Λ. We prove that after renormalizing the mass the binding energy has, to leading order in α, a finite limit as Λ goes to infinity; i.e., the cut-off can be removed. The expression for the ground state energy shift thus obtained agrees with Bethe's formula for small values of Zα, but shows a different behavior for bigger values.},
author = {Hainzl, Christian and Robert Seiringer},
journal = {Advances in Theoretical and Mathematical Physics},
number = {5},
pages = {847 -- 871},
publisher = {International Press},
title = {{Mass renormalization and energy level shift in non-relativistic QED}},
volume = {6},
year = {2002},
}
@article{2351,
abstract = {We study the Gross-Pitaevskii functional for a rotating two-dimensional Bose gas in a trap. We prove that there is a breaking of the rotational symmetry in the ground state; more precisely, for any value of the angular velocity and for large enough values of the interaction strength, the ground state of the functional is not an eigenfunction of the angular momentum. This has interesting consequences on the Bose gas with spin; in particular, the ground state energy depends non-trivially on the number of spin components, and the different components do not have the same wave function. For the special case of a harmonic trap potential, we give explicit upper and lower bounds on the critical coupling constant for symmetry breaking.},
author = {Robert Seiringer},
journal = {Communications in Mathematical Physics},
number = {3},
pages = {491 -- 509},
publisher = {Springer},
title = {{Gross-Pitaevskii theory of the rotating Bose gas}},
doi = {10.1007/s00220-002-0695-2},
volume = {229},
year = {2002},
}
@article{2352,
abstract = {We present a generalization of the Fefferman-de la Llave decomposition of the Coulomb potential to quite arbitrary radial functions V on ℝn going to zero at infinity. This generalized decomposition can be used to extend previous results on N-body quantum systems with Coulomb interaction to a more general class of interactions. As an example of such an application, we derive the high density asymptotics of the ground state energy of jellium with Yukawa interaction in the thermodynamic limit, using a correlation estimate by Graf and Solovej.},
author = {Hainzl, Christian and Robert Seiringer},
journal = {Letters in Mathematical Physics},
number = {1},
pages = {75 -- 84},
publisher = {Springer},
title = {{General decomposition of radial functions on ℝn and applications to N-body quantum systems}},
doi = {10.1023/A:1020204818938},
volume = {61},
year = {2002},
}
@article{2353,
abstract = {A commonly used theoretical definition of superfluidity in the ground state of a Bose gas is based on the response of the system to an imposed velocity field or, equivalently, to twisted boundary conditions in a box. We are able to carry out this program in the case of a dilute interacting Bose gas in a trap, and we prove that a gas with repulsive interactions is 100% superfluid in the dilute limit in which the Gross-Pitaevskii equation is exact. This is the first example in an experimentally realistic continuum model in which superfluidity is rigorously verified.},
author = {Lieb, Élliott H and Robert Seiringer and Yngvason, Jakob},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {13},
publisher = {American Physical Society},
title = {{Superfluidity in dilute trapped Bose gases}},
doi = {10.1103/PhysRevB.66.134529},
volume = {66},
year = {2002},
}
@article{2420,
abstract = {A corner cut in dimension d is a finite subset of N0d that can be separated from its complement in N0d by an affine hyperplane disjoint from N0d. Corner cuts were first investigated by Onn and Sturmfels [Adv. Appl. Math. 23 (1999) 29-48], their original motivation stemmed from computational commutative algebra. Let us write (Nd0k)cut for the set of corner cuts of cardinality k; in the computational geometer's terminology, these are the k-sets of N0d. Among other things, Onn and Sturmfels give an upper bound of O(k2d(d-1)/(d+1)) for the size of (Nd0k)cut when the dimension is fixed. In two dimensions, it is known (see [Corteel et al., Adv. Appl. Math. 23 (1) (1999) 49-53]) that #(Nd0k)cut = Θ(k log k). We will see that in general, for any fixed dimension d, the order of magnitude of #(Nd0k)cut is between kd-1 log k and (k log k)d-1. (It has been communicated to me that the same bounds have been found independently by G. Rémond.) In fact, the elements of (Nd0k)cut correspond to the vertices of a certain polytope, and what our proof shows is that the above upper bound holds for the total number of flags of that polytope.},
author = {Uli Wagner},
journal = {Advances in Applied Mathematics},
number = {2},
pages = {152 -- 161},
publisher = {ACM},
title = {{On the number of corner cuts}},
doi = {10.1016/S0196-8858(02)00014-3},
volume = {29},
year = {2002},
}
@inproceedings{2421,
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 disc and ellipses, and show that it 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. To our knowledge, this is the first hardness result for the Clique problem in intersection graphs of 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},
pages = {489 -- 500},
publisher = {Springer},
title = {{On the Clique problem in intersection graphs of ellipses}},
doi = {10.1007/3-540-36136-7_43},
volume = {2518},
year = {2002},
}
@article{2613,
abstract = {In this investigation, we report identification and characterization of a 95 kDa postsynaptic density protein (PSD-95)/discs-large/ ZO-1 (PDZ) domain-containing protein termed tamalin, also recently named GRP1-associated scaffold protein (GRASP), that interacts with group 1 metabotropic glutamate receptors (mGluRs). The yeast two-hybrid system and in vitro pull-down assays indicated that the PDZ domain-containing, amino-terminal half of tamalin directly binds to the class I PDZ-binding motif of group 1 mGluRs. The C-terminal half of tamalin also bound to cytohesins, the members of guanine nucleotide exchange factors (GEFs) specific for the ADP-ribosylation factor (ARF) family of small GTP-binding proteins. Tamalin mRNA is expressed predominantly in the telencephalic region and highly overlaps with the expression of group 1 mGluR mRNAs. Both tamalin and cytohesin-2 were enriched and codistributed with mGluR1a in postsynaptic membrane fractions. Importantly, recombinant and native mGluR1a/tamalin/cytohesin-2 complexes were coimmunoprecipitated from transfected COS-7 cells and rat brain tissue, respectively. Transfection of tamalin and mutant tamalin lacking a cytohesin-binding domain caused an increase and decrease in cell-surface expression of mGluR1a in COS-7 cells, respectively. Furthermore, adenovirus-mediated expression of tamalin and dominant-negative tamalin facilitated and reduced the neuritic distribution of endogenous mGluR5 in cultured hippocampal neurons, respectively. The results indicate that tamalin plays a key role in the association of group 1 mGluRs with the ARF-specific GEF proteins and contributes to intracellular trafficking and the macromolecular organization of group 1 mGluRs at synapses.},
author = {Kitano, Jun and Kimura, Kouji and Yamazaki, Yoshimitsu and Soda, Takeshi and Ryuichi Shigemoto and Nakajima, Yoshiaki and Nakanishi, Shigetada},
journal = {Journal of Neuroscience},
number = {4},
pages = {1280 -- 1289},
publisher = {Society for Neuroscience},
title = {{Tamalin, a PDZ domain-containing protein, links a protein complex formation of group 1 metabotropic glutamate receptors and the guanine nucleotide exchange factor cytohesins}},
volume = {22},
year = {2002},
}