@article{3731, abstract = {A cell's ability to regulate gene transcription depends in large part on the energy with which transcription factors (TFs) bind their DNA regulatory sites. Obtaining accurate models of this binding energy is therefore an important goal for quantitative biology. In this article, we present a principled likelihood-based approach for inferring physical models of TF-DNA binding energy from the data produced by modern high-throughput binding assays. Central to our analysis is the ability to assess the relative likelihood of different model parameters given experimental observations. We take a unique approach to this problem and show how to compute likelihood without any explicit assumptions about the noise that inevitably corrupts such measurements. Sampling possible choices for model parameters according to this likelihood function, we can then make probabilistic predictions for the identities of binding sites and their physical binding energies. Applying this procedure to previously published data on the Saccharomyces cerevisiae TF Abf1p, we find models of TF binding whose parameters are determined with remarkable precision. Evidence for the accuracy of these models is provided by an astonishing level of phylogenetic conservation in the predicted energies of putative binding sites. Results from in vivo and in vitro experiments also provide highly consistent characterizations of Abf1p, a result that contrasts with a previous analysis of the same data.}, author = {Kinney,Justin B and Gasper Tkacik and Callan,Curtis G}, journal = {PNAS}, number = {2}, pages = {501 -- 506}, publisher = {National Academy of Sciences}, title = {{Precise physical models of protein-DNA interaction from high-throughput data}}, doi = {10.1073/pnas.0609908104}, volume = {104}, year = {2007}, } @unpublished{3742, abstract = {Recent work has shown that probabilistic models based on pairwise interactions-in the simplest case, the Ising model-provide surprisingly accurate descriptions of experiments on real biological networks ranging from neurons to genes. Finding these models requires us to solve an inverse problem: given experimentally measured expectation values, what are the parameters of the underlying Hamiltonian? This problem sits at the intersection of statistical physics and machine learning, and we suggest that more efficient solutions are possible by merging ideas from the two fields. We use a combination of recent coordinate descent algorithms with an adaptation of the histogram Monte Carlo method, and implement these techniques to take advantage of the sparseness found in data on real neurons. The resulting algorithm learns the parameters of an Ising model describing a network of forty neurons within a few minutes. This opens the possibility of analyzing much larger data sets now emerging, and thus testing hypotheses about the collective behaviors of these networks.}, author = {Broderick,Tamara and Dudik,Miroslav and Gasper Tkacik and Schapire,Robert E and Bialek, William S}, booktitle = {ArXiv}, publisher = {ArXiv}, title = {{Faster solutions of the inverse pairwise Ising problem}}, volume = {q-bio.QM}, year = {2007}, } @inproceedings{3762, abstract = {In this paper, we present a simple method for animating natural phenomena such as erosion, sedimentation, and acidic corrosion. We discretize the appropriate physical or chemical equations using finite differences, and we use the results to modify the shape of a solid body. We remove mass from an object by treating its surface as a level set and advecting it inward, and we deposit the chemical and physical byproducts into simulated fluid. Similarly, our technique deposits sediment onto a surface by advecting the level set outward. Our idea can be used for off-line high quality animations as well as interactive applications such as games, and we demonstrate both in this paper.}, author = {Wojtan, Christopher J and Carlson, Mark and Mucha, Peter and Turk, Greg}, pages = {15 -- 22}, publisher = {Eurographics Association}, title = {{Animating corrosion and erosion}}, doi = {10.2312/NPH/NPH07/015-022}, year = {2007}, } @article{3765, abstract = {We present an extension to Lagrangian finite element methods to allow for large plastic deformations of solid materials. These behaviors are seen in such everyday materials as shampoo, dough, and clay as well as in fantastic gooey and blobby creatures in special effects scenes. To account for plastic deformation, we explicitly update the linear basis functions defined over the finite elements during each simulation step. When these updates cause the basis functions to become ill-conditioned, we remesh the simulation domain to produce a new high-quality finite-element mesh, taking care to preserve the original boundary. We also introduce an enhanced plasticity model that preserves volume and includes creep and work hardening/softening. We demonstrate our approach with simulations of synthetic objects that squish, dent, and flow. To validate our methods, we compare simulation results to videos of real materials.}, author = {Bargteil, Adam and Wojtan, Christopher J and Hodgins, Jessica and Turk, Greg}, journal = {ACM Transactions on Graphics}, number = {3}, publisher = {ACM}, title = {{A finite element method for animating large viscoplastic flow}}, doi = {10.1145/1276377.1276397}, volume = {26}, year = {2007}, } @article{3816, abstract = {Gamma frequency oscillations are thought to provide a temporal structure for information processing in the brain. They contribute to cognitive functions, such as memory formation and sensory processing, and are disturbed in some psychiatric disorders. Fast-spiking, parvalbumin-expressing, soma-inhibiting interneurons have a key role in the generation of these oscillations. Experimental analysis in the hippocampus and the neocortex reveals that synapses among these interneurons are highly specialized. Computational analysis further suggests that synaptic specialization turns interneuron networks into robust gamma frequency oscillators.}, author = {Bartos, Marlene and Vida, Imre and Peter Jonas}, journal = {Nature Reviews Neuroscience}, number = {1}, pages = {45 -- 56}, publisher = {Nature Publishing Group}, title = {{Synaptic mechanisms of synchronized gamma oscillations in inhibitory interneuron networks (Review)}}, doi = {10.1038/nrn2044 }, volume = {8}, year = {2007}, } @article{3819, abstract = {Voltage-gated Ca2+ channels in presynaptic terminals initiate the Ca2+ inflow necessary for transmitter release. At a variety of synapses, multiple Ca2+ channel subtypes are involved in synaptic transmission and plasticity. However, it is unknown whether presynaptic Ca2+ channels differ in gating properties and whether they are differentially activated by action potentials or subthreshold voltage signals. We examined Ca2+ channels in hippocampal mossy fiber boutons (MFBs) by presynaptic recording, using the selective blockers omega-agatoxin IVa, omega-conotoxin GVIa, and SNX-482 to separate P/Q-, N-, and R-type components. Nonstationary fluctuation analysis combined with blocker application revealed a single MFB contained on average approximately 2000 channels, with 66% P/Q-, 26% N-, and 8% R-type channels. Whereas both P/Q-type and N-type Ca2+ channels showed high activation threshold and rapid activation and deactivation, R-type Ca2+ channels had a lower activation threshold and slower gating kinetics. To determine the efficacy of activation of different Ca2+ channel subtypes by physiologically relevant voltage waveforms, a six-state gating model reproducing the experimental observations was developed. Action potentials activated P/Q-type Ca2+ channels with high efficacy, whereas N- and R-type channels were activated less efficiently. Action potential broadening selectively recruited N- and R-type channels, leading to an equalization of the efficacy of channel activation. In contrast, subthreshold presynaptic events activated R-type channels more efficiently than P/Q- or N-type channels. In conclusion, single MFBs coexpress multiple types of Ca2+ channels, which are activated differentially by subthreshold and suprathreshold presynaptic voltage signals.}, author = {Li, Liyi and Bischofberger, Josef and Peter Jonas}, journal = {Journal of Neuroscience}, number = {49}, pages = {13420 -- 9}, publisher = {Society for Neuroscience}, title = {{Differential gating and recruitment of P/Q-, N-, and R-type Ca(2+) channels in hippocampal mossy fiber boutons}}, doi = {10.1523/JNEUROSCI.1709-07.2007}, volume = {27}, year = {2007}, } @article{3820, abstract = {Synapses are the key elements for signal processing and plasticity in the brain. To determine the structural factors underlying the unique functional properties of the hippocampal mossy fiber synapse, the complete quantitative geometry was investigated, using electron microscopy of serial ultrathin sections followed by computer-assisted three-dimensional reconstruction. In particular, parameters relevant for transmitter release and synaptic plasticity were examined. Two membrane specializations were found: active zones (AZs), transmitter release sites, and puncta adherentia, putative adhesion complexes. Individual boutons had, on average, 25 AZs (range, 7-45) that varied in shape and size (mean, 0.1 microm2; range, 0.07-0.17 microm2). The mean distance between individual AZs was 0.45 microm. Mossy fiber boutons and their target structures were mostly ensheathed by astrocytes, but fine glial processes never reached the active zones. Two structural factors are likely to promote synaptic cross talk: the short distance between AZs and the absence of fine glial processes at AZs. Thus, synaptic cross talk may contribute to the efficacy of hippocampal mossy fiber synapses. On average, a bouton contained 20,400 synaptic vesicles; approximately 900 vesicles were located within 60 nm from the active zone, approximately 4400 between 60 and 200 nm, and the remaining beyond 200 nm, suggesting large readily releasable, recycling, and reserve pools. The organization of the different pools may be a key structural correlate of presynaptic plasticity at this synapse. Thus, the mossy fiber bouton differs fundamentally in structure and function from the calyx of Held and other central synapses.}, author = {Rollenhagen, Astrid and Satzler, Kurt and Rodriguez, E Patricia and Peter Jonas and Frotscher, Michael and Lubke, Joachim H}, journal = {Journal of Neuroscience}, number = {39}, pages = {10434 -- 44}, publisher = {Society for Neuroscience}, title = {{Structural determinants of transmission at large hippocampal mossy fiber synapses}}, doi = {10.1523/JNEUROSCI.1946-07.2007}, volume = {27}, year = {2007}, } @article{3821, abstract = {Although dendritic signal processing has been extensively investigated in hippocampal pyramidal cells, only little is known about dendritic integration of synaptic potentials in dentate gyrus granule cells, the first stage in the hippocampal trisynaptic circuit. Here we combined dual whole-cell patch-clamp recordings with high-resolution two-photon microscopy to obtain detailed passive cable models of hippocampal granule cells from adult mice. Passive cable properties were determined by direct fitting of the compartmental model to the experimentally measured voltage responses to short and long current pulses. The data are best fit by a cable model with homogenously distributed parameters, including an average specific membrane resistance (R(m)) of 38.0 kohms cm2, a membrane capacitance (C(m)) of 1.0 microF cm(-2), and an intracellular resistivity (R(i)) of 194 ohms cm. Computational analysis shows that signal propagation from somata into dendrites is more efficient in granule cells compared with CA1 pyramidal cells for both steady-state and sinusoidal voltage waveforms up to the gamma frequency range (f50% of 74 Hz). Similarly, distal synaptic inputs from entorhinal fibers can efficiently depolarize the somatic membrane of granule cells. Furthermore, the time course of distal dendritic synaptic potentials is remarkably fast, and temporal summation is restricted to a narrow time window in the range of approximately 10 ms attributable to the rapid dendritic charge redistribution during transient voltage signals. Therefore, the structure of the granule cell dendritic tree may be critically important for precise dendritic signal processing and coincidence detection during hippocampus-dependent memory formation and retrieval.}, author = {Schmidt-Hieber, Christoph and Peter Jonas and Bischofberger, Josef}, journal = {Journal of Neuroscience}, number = {31}, pages = {8430 -- 8441}, publisher = {Society for Neuroscience}, title = {{Subthreshold dendritic signal processing and coincidence detection in dentate gyrus granule cells}}, doi = {10.1523/JNEUROSCI.1787-07.2007}, volume = {27}, year = {2007}, } @inproceedings{3881, abstract = {We present Qualitative Randomized CTL (QRCTL), a qualitative version of pCTL, for specifying properties of Markov Decision Processes (MDPs). QRCTL formulas can express the fact that certain temporal properties hold with probability 0 or 1, but they do not distinguish other probabilities values. We present a symbolic, polynomial time model-checking algorithm for QRCTL on MDPs. Then, we study the equivalence relation induced by QRCTL, called qualitative equivalence. We show that for finite alternating MDPs, where nondeterministic and probabilistic choice occur in different states, qualitative equivalence coincides with alternating bisimulation, and can thus be computed via efficient partition-refinement algorithms. Surprisingly, the result does not hold for non-alternating MDPs. Indeed, we show that no local partition refinement algorithm can compute qualitative equivalence on non-alternating MDPs. Finally, we consider QRCTL*, that is the “star extension” of QRCTL. We show that QRCTL and QRCTL* induce the same qualitative equivalence on alternating MDPs, while on non-alternating MDPs, the equivalence, arising from QRCTL* can be strictly finer We also provide a full characterization of the relation between qualitative equivalence, bisimulation, and alternating bisimulation, according to whether the MDPs are finite, and to whether their transition relations are finite-branching.}, author = {de Alfaro, Luca and Krishnendu Chatterjee and Faella, Marco and Legay, Axel}, pages = {237 -- 248}, publisher = {IEEE}, title = {{Qualitative logics and equivalences for probabilistic systems}}, doi = {10.1109/QEST.2007.15}, year = {2007}, } @article{3882, abstract = {We study infinite stochastic games played by two players over a finite state space, with objectives specified by sets of infinite traces. The games are concurrent (players make moves simultaneously and independently), stochastic (the next state is determined by a probability distribution that depends on the current state and chosen moves of the players) and infinite (proceed for an infinite number of rounds). The analysis of concurrent stochastic games can be classified into: quantitative analysis, analyzing the optimum value of the game and epsilon-optimal strategies that ensure values within epsilon of the optimum value; and qualitative analysis, analyzing the set of states with optimum value 1 and epsilon-optimal strategies for the states with optimum value 1. We consider concurrent games with tail objectives, i.e., objectives that are independent of the finite-prefix of traces, and show that the class of tail objectives is strictly richer than that of the omega-regular objectives. We develop new proof techniques to extend several properties of concurrent games with omega-regular objectives to concurrent games with tail objectives. We prove the positive limit-one property for tail objectives. The positive limit-one property states that for all concurrent games if the optimum value for a player is positive for a tail objective Phi at some state, then there is a state where the optimum value is 1 for the player for the objective Phi. We also show that the optimum values of zero-sum (strictly conflicting objectives) games with tail objectives can be related to equilibrium values of nonzerosum (not strictly conflicting objectives) games with simpler reachability objectives. A consequence of our analysis presents a polynomial time reduction of the quantitative analysis of tail objectives to the qualitative analysis for the subclass of one-player stochastic games (Markov decision processes). }, author = {Krishnendu Chatterjee}, journal = {Theoretical Computer Science}, number = {1-3}, pages = {181 -- 198}, publisher = {Elsevier}, title = {{Concurrent games with tail objectives}}, doi = {10.1016/j.tcs.2007.07.047}, volume = {388}, year = {2007}, } @inproceedings{3883, abstract = {We consider games where the winning conditions are disjunctions (or dually, conjunctions) of parity conditions; we call them generalized parity games. These winning conditions, while omega-regular, arise naturally when considering fair simulation between parity automata, secure equilibria for parity conditions, and determinization of Rabin automata. We show that these games retain the computational complexity of Rabin and Streett conditions; i.e., they are NP-complete and co-NP-complete, respectively. The (co-) NP-hardness is proved for the special case of a conjunction/disjunction of two parity conditions, which is the case that arises in fair simulation and secure equilibria. However, considering these games as Rabin or Streett games is not optimal. We give an exposition of Zielonka's algorithm when specialized to this kind of games. The complexity of solving these games for k parity objectives with d priorities, n states, and m edges is O(n(2kd) (.) m) (.) (k(.)d)!/ d!(k), as compared to O(n(2kd .) m) - (k (.) d)! when these games are solved as Rabin/Streett games. We also extend the subexponential algorithm for solving parity games recently introduced by Jurdzinski, Paterson, and Zwick to generalized parity games. The resulting complexity of solving generalized parity games is n(O(root n)) (.) (k(.)d)!/d!(k). As a corollary we obtain an improved ald!k gorithm for Rabin and Streett games with d pairs, with time complexity n(O(root n)) (.) d!.}, author = {Krishnendu Chatterjee and Thomas Henzinger and Piterman, Nir}, pages = {153 -- 167}, publisher = {Springer}, title = {{Generalized parity games}}, doi = {10.1007/978-3-540-71389-0_12}, volume = {4423}, year = {2007}, } @inproceedings{3884, abstract = {We introduce strategy logic, a logic that treats strategies in two-player games as explicit first-order objects. The explicit treatment of strategies allows us to specify properties of nonzero-sum games in a simple and natural way. We show that the one-alternation fragment of strategy logic is strong enough to express the existence of Nash equilibria and secure equilibria, and subsumes other logics that were introduced to reason about games, such as ATL, ATL*, and game logic. We show that strategy logic is decidable, by constructing tree automata that recognize sets of strategies. While for the general logic, our decision procedure is nonelementary, for the simple fragment that is used above we show that the complexity is polynomial in the size of the game graph and optimal in the size of the formula (ranging from polynomial to 2EXPTIME depending on the form of the formula).}, author = {Krishnendu Chatterjee and Thomas Henzinger and Piterman, Nir}, pages = {59 -- 73}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Strategy logic}}, doi = {10.1007/978-3-540-74407-8_5}, volume = {4703}, year = {2007}, } @inproceedings{3885, abstract = {The theory of graph games with ω-regular winning conditions is the foundation for modeling and synthesizing reactive processes. In the case of stochastic reactive processes, the corresponding stochastic graph games have three players, two of them (System and Environment) behaving adversarially, and the third (Uncertainty) behaving probabilistically. We consider two problems for stochastic graph games: the qualitative problem asks for the set of states from which a player can win with probability 1 (almost-sure winning); and the quantitative problem asks for the maximal probability of winning (optimal winning) from each state. We consider ω-regular winning conditions formalized as Müller winning conditions. We present optimal memory bounds for pure almost-sure winning and optimal winning strategies in stochastic graph games with Müller winning conditions. We also present improved memory bounds for randomized almost-sure winning and optimal strategies.}, author = {Krishnendu Chatterjee}, pages = {138 -- 152}, publisher = {Springer}, title = {{Optimal strategy synthesis in stochastic Müller games}}, doi = {10.1007/978-3-540-71389-0_11}, volume = {4423}, year = {2007}, } @inproceedings{3886, abstract = {The theory of graph games with ω-regular winning conditions is the foundation for modeling and synthesizing reactive processes. In the case of stochastic reactive processes, the corresponding stochastic graph games have three players, two of them (System and Environment) behaving adversarially, and the third (Uncertainty) behaving probabilistically. We consider two problems for stochastic graph games: the qualitative problem asks for the set of states from which a player can win with probability 1 (almost-sure winning); and the quantitative problem asks for the maximal probability of winning (optimal winning) from each state. We consider ω-regular winning conditions formalized as Müller winning conditions. We show that both the qualitative and quantitative problem for stochastic Müller games are PSPACE-complete. We also consider two well-known sub-classes of Müller objectives, namely, upward-closed and union-closed objectives, and show that both the qualitative and quantitative problem for these sub-classes are coNP-complete.}, author = {Krishnendu Chatterjee}, pages = {436 -- 448}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Stochastic Müller games are PSPACE-complete}}, doi = {10.1007/978-3-540-77050-3_36}, volume = {4855}, year = {2007}, } @inproceedings{3887, abstract = {We consider Markov decision processes (MDPs) with multiple long-run average objectives. Such MDPs occur in design problems where one wishes to simultaneously optimize several criteria, for example, latency and power. The possible trade-offs between the different objectives are characterized by the Pareto curve. We show that every Pareto optimal point can be epsilon-approximated by a memoryless strategy, for all epsilon > 0. In contrast to the single-objective case, the memoryless strategy may require randomization. We show that the Pareto curve can be approximated (a) in polynomial time in the size of the MDP for irreducible MDPs; and (b) in polynomial space in the size of the MDP for all MDPs. Additionally, we study the problem if a given value vector is realizable by any strategy, and show that it can be decided in polynomial time for irreducible MDPs and in NP for all MDPs. These results provide algorithms for design exploration in MDP models with multiple long-run average objectives.}, author = {Krishnendu Chatterjee}, pages = {473 -- 484}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Markov decision processes with multiple long-run average objectives}}, doi = {10.1007/978-3-540-77050-3_39}, volume = {4855}, year = {2007}, } @article{3909, abstract = {Social insect colonies have evolved collective immune defences against parasites. These ‘social immune systems’ result from the cooperation of the individual group members to combat the increased risk of disease transmission that arises from sociality and group living. In this review we illustrate the pathways that parasites can take to infect a social insect colony and use these pathways as a framework to predict colony defence mechanisms and present the existing evidence. We find that the collective defences can be both prophylactic and activated on demand and consist of behavioural, physiological and organisational adaptations of the colony that prevent parasite entrance, establishment and spread. We discuss the regulation of collective immunity, which requires complex integration of information about both the parasites and the internal status of the insect colony. Our review concludes with an examination of the evolution of social immunity, which is based on the consequences of selection at both the individual and the colony level.}, author = {Cremer, Sylvia and Armitage, Sophie and Schmid Hempel, Paul}, journal = {Current Biology}, number = {16}, pages = {R693 -- R702}, publisher = {Cell Press}, title = {{Social immunity}}, doi = {10.1016/j.cub.2007.06.008}, volume = {17}, year = {2007}, } @article{3910, author = {Hughes, David and Cremer, Sylvia}, journal = {Animal Behaviour}, number = {5}, pages = {1593 -- 1599}, publisher = {Elsevier}, title = {{Plasticity in anti-parasite behaviours and its suggested role in invasion biology}}, doi = {10.1016/j.anbehav.2006.12.025}, volume = {74}, year = {2007}, } @article{3911, abstract = {Life in a social group increases the risk of disease transmission. To counteract this threat, social insects have evolved manifold antiparasite defenses, ranging from social exclusion of infected group members to intensive care. It is generally assumed that individuals performing hygienic behaviors risk infecting themselves, suggesting a high direct cost of helping. Our work instead indicates the opposite for garden ants. Social contact with individual workers, which were experimentally exposed to a fungal parasite, provided a clear survival benefit to nontreated, naive group members upon later challenge with the same parasite. This first demonstration of contact immunity in Social Hymenoptera and complementary results from other animal groups and plants suggest its general importance in both antiparasite and antiherbivore defense. In addition to this physiological prophylaxis of adult ants, infection of the brood was prevented in our experiment by behavioral changes of treated and naive workers. Parasite-treated ants stayed away from the brood chamber, whereas their naive nestmates increased brood-care activities. Our findings reveal a direct benefit for individuals to perform hygienic behaviors toward others, and this might explain the widely observed maintenance of social cohesion under parasite attack in insect societies.}, author = {Ugelvig, Line V and Cremer, Sylvia}, journal = {Current Biology}, number = {22}, pages = {1967 -- 1971}, publisher = {Cell Press}, title = {{Social prophylaxis: group interaction promotes collective immunity in ant colonies}}, doi = {10.1016/j.cub.2007.10.029}, volume = {17}, year = {2007}, } @article{3937, abstract = {Lymphocyte motility in lymph nodes is regulated by chemokines, but the contribution of integrins to this motility remains obscure. Here we examined lymphocyte migration over CCR7-binding chemokines that 'decorate' lymph node stroma. In a shear-free environment, surface-bound lymph node chemokines but not their soluble counterparts promoted robust and sustained T lymphocyte motility. The chemokine CCL21 induced compartmentalized clustering of the integrins LFA-1 and VLA-4 in motile lymphocytes, but both integrins remained nonadhesive to ligands on lymphocytes, dendritic cells and stroma. The application of shear stress to lymphocytes interacting with CCL21 and integrin ligands promoted robust integrin-mediated adhesion. Thus, lymph node chemokines that promote motility and strongly activate lymphocyte integrins under shear forces fail to stimulate stable integrin adhesiveness in extravascular shear-free environments.}, author = {Woolf, Eilon and Grigorova, Irina and Sagiv, Adi and Grabovsky, Valentin and Feigelson, Sara W and Shulman, Ziv and Hartmann, Tanja and Michael Sixt and Cyster, Jason G and Alon, Ronen}, journal = {Nature Immunology}, number = {10}, pages = {1076 -- 1085}, publisher = {Nature Publishing Group}, title = {{Lymph node chemokines promote sustained T lymphocyte motility without triggering stable integrin adhesiveness in the absence of shear forces}}, doi = {10.1038/ni1499}, volume = {8}, year = {2007}, } @article{3938, abstract = {RhoH is a small GTPase expressed only in the hematopoietic system. With the use of mice with targeted disruption of the RhoH gene, we demonstrated that RhoH is crucial for thymocyte maturation during DN3 to DN4 transition and during positive selection. Furthermore, the differentiation and expansion of DN3 and DN4 thymocytes in vitro were severely impaired. These defects corresponded to defective TCR signaling. Although RhoH is not required for TCR-induced activation of ZAP70 and ZAP70-mediated activation of p38, it is crucial for the tyrosine phosphorylation of LAT, PLCgamma1, and Vav1 and for the activation of Erk and calcium influx. These data suggest that RhoH is important for pre-TCR and TCR signaling because it allows the efficient interaction of ZAP70 with the LAT signalosome, thus regulating thymocyte development.}, author = {Dorn, Tatjana and Kuhn, Ursula and Bungartz, Gerd and Stiller, Sebastian and Bauer, Martina and Ellwart, Joachim and Peters, Thorsten and Scharffetter-Kochanek, Karin and Semmrich, Monika and Laschinger, Melanie and Holzmann, Bernhard and Klinkert, Wolfgang E and Straten, Per Thor and Køllgaard, Tania and Michael Sixt and Brakebusch, Cord}, journal = {Blood}, number = {6}, pages = {2346 -- 2355}, publisher = {American Society of Hematology}, title = {{RhoH is important for positive thymocyte selection and T-cell receptor signaling}}, doi = {10.1182/blood-2006-04-019034}, volume = {109}, year = {2007}, }