@misc{3814,
abstract = {The axon terminals (mossy fibers) of hippocampal dentate granule cells form characteristic synaptic connections with large spines or excrescences of both hilar mossy cells and CA3 pyramidal neurons. Interneurons of the hilar region and area CA3 are also prominent targets of mossy fibers. The tracing of biocytin-filled mossy fibers and immunolabeling of target cells with interneuron markers has revealed that the majority of mossy fiber synapses project to gamma aminobutyric acid (GABA)-ergic inhibitory interneurons rather than to excitatory principal cells, although the functional implications of these quantitative differences are unclear. Following a brief description of the "classical" mossy fiber synapse on excrescences of CA3 pyramidal cells, the present review focuses on the contacts formed between granule cells and GABAergic interneurons, both normally and after synaptic reorganization. In response to deafferentation of mossy cell target cells, which include both granule cells and interneurons, mossy fibers "sprout" new axon collaterals that form a band of supragranular mossy fibers in the inner molecular layer of the dentate gyrus. Although most newly formed recurrent mossy fibers establish synapses with granule cells, there is an apparently convergent input of new mossy fibers onto GABA-immunoreactive interneuron dendrites that traverse the inner molecular layer. These mossy fiber-interneuron synapses in the dentate gyrus are observed in chronically epileptic rats and may be the structural correlate of the granule cell hyperinhibition observed in these animals in vivo. Together, the findings reviewed here establish mossy fiber synapses as an important component of inhibitory circuits in the hippocampus.},
author = {Frotscher, Michael and Peter Jonas and Sloviter, Robert S},
booktitle = {Cell and Tissue Research},
number = {2},
pages = {361 -- 7},
publisher = {Springer},
title = {{Synapses formed by normal and abnormal hippocampal mossy fibers (Review)}},
doi = {10.1007/s00441-006-0269-2},
volume = {326},
year = {2006},
}
@inproceedings{3888,
abstract = {A stochastic graph game is played by two players on a game graph with probabilistic transitions. We consider stochastic graph games with omega-regular winning conditions specified as Rabin or Streett objectives. These games are NP-complete and coNP-complete, respectively. The value of the game for a player at a state s given an objective Phi is the maximal probability with which the player can guarantee the satisfaction of Phi from s. We present a strategy-improvement algorithm to compute values in stochastic Rabin games, where an improvement step involves solving Markov decision processes (MDPs) and nonstochastic Rabin games. The algorithm also computes values for stochastic Streett games but does not directly yield an optimal strategy for Streett objectives. We then show how to obtain an optimal strategy for Streett objectives by solving certain nonstochastic Streett games.},
author = {Krishnendu Chatterjee and Thomas Henzinger},
pages = {375 -- 389},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Strategy improvement for stochastic Rabin and Streett games}},
doi = {10.1007/11817949_25},
volume = {4137},
year = {2006},
}
@inproceedings{3890,
abstract = {We consider two-player infinite games played on graphs. The games are concurrent, in that at each state the players choose their moves simultaneously and independently, and stochastic, in that the moves determine a probability distribution for the successor state. The value of a game is the maximal probability with which a player can guarantee the satisfaction of her objective. We show that the values of concurrent games with w-regular objectives expressed as parity conditions can be decided in NP boolean AND coNP. This result substantially improves the best known previous bound of 3EXPTIME. It also shows that the full class of concurrent parity games is no harder than the special case of turn-based stochastic reachability games, for which NP boolean AND coNP is the best known bound. While the previous, more restricted NP boolean AND coNP results for graph games relied on the existence of particularly simple (pure memoryless) optimal strategies, in concurrent games with parity objectives optimal strategies may not exist, and epsilon-optimal strategies (which achieve the value of the game within a parameter epsilon > 0) require in general both randomization and infinite memory. Hence our proof must rely on a more detailed analysis of strategies and, in addition to the main result, yields two results that are interesting on their own. First, we show that there exist epsilon-optimal strategies that in the limit coincide with memoryless strategies; this parallels the celebrated result of Mertens-Neyman for concurrent games with limit-average objectives. Second, we complete the characterization of the memory requirements for epsilon-optimal strategies for concurrent games with parity conditions, by showing that memoryless strategies suffice for epsilon-optimality for coBachi conditions.},
author = {Krishnendu Chatterjee and de Alfaro, Luca and Thomas Henzinger},
pages = {678 -- 687},
publisher = {SIAM},
title = {{The complexity of quantitative concurrent parity games}},
doi = {10.1145/1109557.1109631},
year = {2006},
}
@article{3908,
abstract = {It is commonly believed that both the average length and the frequency of microsatellites correlate with genome size. We have estimated the frequency and the average length for 69 perfect dinucleotide microsatellites in an insect with an exceptionally large genome: Chorthippus biguttulus (Orthoptera, Acrididae). Dinucleotide microsatellites are not more frequent in C. biguttulus, but repeat arrays are 1.4 to 2 times longer than in other insect species. The average repeat number in C. biguttulus lies in the range of higher vertebrates. Natural populations are highly variable. At least 30 alleles per locus were found and the expected heterozygosity is above 0.95 at all three loci studied. In contrast, the observed heterozygosity is much lower (≤0.51), which could be caused by long null alleles.},
author = {Ustinova, Jana and Achmann, Roland and Cremer, Sylvia and Mayer, Frieder},
journal = {Journal of Molecular Evolution},
number = {2},
pages = {158 -- 167},
publisher = {Springer},
title = {{Long repeats in a huge gemome: microsatellite loci in the grasshopper Chorthippus biguttulus}},
doi = {10.1007/s00239-005-0022-6},
volume = {62},
year = {2006},
}
@article{3934,
abstract = {T cells develop in the thymus in a highly specialized cellular and extracellular microenvironment. The basement membrane molecule, laminin-5 (LN-5), is predominantly found in the medulla of the human thymic lobules. Using high-resolution light microscopy, we show here that LN-5 is localized in a bi-membranous conduit-like structure, together with other typical basement membrane components including collagen type IV, nidogen and perlecan. Other interstitial matrix components, such as fibrillin-1 or -2, tenascin-C or fibrillar collagen types, were also associated with these structures. Three-dimensional (3D) confocal microscopy suggested a tubular structure, whereas immunoelectron and transmission electron microscopy showed that the core of these tubes contained fibrillar collagens enwrapped by the LN-5-containing membrane. These medullary conduits are surrounded by thymic epithelial cells, which in vitro were found to bind LN-5, but also fibrillin and tenascin-C. Dendritic cells were also detected in close vicinity to the conduits. Both of these stromal cell types express major histocompatibility complex (MHC) class II molecules capable of antigen presentation. The conduits are connected to blood vessels but, with an average diameter of 2 mum, they are too small to transport cells. However, evidence is provided that smaller molecules such as a 10 kDa dextran, but not large molecules (>500 kDa), can be transported in the conduits. These results clearly demonstrate that a conduit system, which is also known from secondary lymphatic organs such as lymph nodes and spleen, is present in the medulla of the human thymus, and that it might serve to transport small blood-borne molecules or chemokines to defined locations within the medulla.},
author = {Drumea-Mirancea, Mihaela and Wessels, Johannes T and Müller, Claudia A and Essl, Mike and Eble, Johannes A and Tolosa, Eva and Koch, Manuel and Reinhardt, Dieter P and Michael Sixt and Sorokin, Lydia and Stierhof, York-Dieter and Schwarz, Heinz and Klein, Gerd},
journal = {Journal of Cell Science},
number = {Pt 7},
pages = {1396 -- 1405},
publisher = {Company of Biologists},
title = {{Characterization of a conduit system containing laminin-5 in the human thymus: a potential transport system for small molecules}},
doi = {10.1242/jcs.02840},
volume = {119},
year = {2006},
}