@article{2643, abstract = {Metabotropic γ-aminobutyric acid receptors (GABAB) are involved in pre- and postsynaptic inhibitory effects upon auditory neurons and have been implicated in different aspects of acoustic information processing. To understand better the mechanisms by which GABAB receptors mediate their inhibitory effects, we used pre-embedding immunocytochemical techniques combined with quantification of immunogold particles to reveal the precise subcellular distribution of the GABAB1 subunit in the rat dorsal cochlear nucleus. At the light microscopic level, GABAB1 was detected in all divisions of the cochlear complex. The most intense immunoreactivity for GABAB1 was found in the dorsal cochlear nucleus, whereas immunoreactivity in the anteroventral and posteroventral cochlear nuclei was very low. In the dorsal cochlear nucleus, a punctate labeling was observed in the superficial (molecular and fusiform cell) layers. At the electron microscopic level, GABAB1 was found at both post- and presynaptic locations. Postsynaptically, GABAB1 was localized mainly in the dendritic spines of presumed fusiform cells. Quantitative immunogold immunocytochemistry revealed that the highest concentration of GABA B1 in the plasma membrane was in dendritic spines, followed by dendritic shafts and somata. Thus, the most intense immunoreactivity for GABAB1 was observed in dendritic spines with a high density of immunogold particles at extrasynaptic sites, peaking around 300 nm from glutamatergic synapses. This is in contrast to GABAergic synapses, in which GABAB1 was only occasionally found. Presynaptically, receptor immunoreactivity was detected primarily in axospinous endings, probably from granule cells, in both the active zone and extrasynaptic sites. The localization of GABAB1 relative to synaptic sites in the DCN suggests a role for the receptor in the regulation of dendritic excitability and excitatory inputs.}, author = {Luján, Rafael and Ryuichi Shigemoto and Kulik, Ákos and Juíz, José M}, journal = {Journal of Comparative Neurology}, number = {1}, pages = {36 -- 46}, publisher = {Wiley-Blackwell}, title = {{Localization of the GABAB receptor 1a/b subunit relative to glutamatergic synapses in the dorsal cochlear nucleus of the rat}}, doi = {10.1002/cne.20160}, volume = {475}, year = {2004}, } @article{2638, abstract = {Among various types of low- and high-threshold calcium channels, the high voltage-activated P/Q-type channel is the most abundant in the cerebellum. These P/Q-type channels are involved in the regulation of neurotransmitter release and in the integration of dendritic inputs. We used an antibody specific for the α1A subunit of the P/Q-type channel in quantitative pre-embedding immunogold labelling combined with three-dimensional reconstruction to reveal the subcellular distribution of pre- and postsynaptic P/Q-type channels in the rat cerebellum. At the light microscopic level, immunoreactivity for the α1A protein was prevalent in the molecular layer, whereas immunostaining was moderate in the somata of Purkinje cells and weak in the granule cell layer. At the electron microscopic level, the most intense Immunoreactivity for the α1A subunit was found in the presynaptic active zone of parallel fibre varicosities. The dendritic spines of Purkinje cells were also strongly labelled with the highest density of immunoparticles detected within 180 nm from the edge of the asymmetrical parallel fibre-Purkinje cell synapses. By contrast, the immunolabelling was sparse in climbing fibre varicosities and axon terminals of GABAergic cells, and weak and diffuse in dendritic shafts of Purkinje cells. The association of the α1A subunit with the glutamatergic parallel fibre-Purkinje cell synapses suggests that presynaptic channels have a major role in the mediation of excitatory neurotransmission, whereas postsynaptic channels are likely to be involved in depolarization-induced generation of local calcium transients in Purkinje cells.}, author = {Kulik, Ákos and Nakadate, Kazuhiko and Hagiwara, Akari and Fukazawa, Yugo and Luján, Rafael and Saito, Hiromitsu and Suzuki, Noboru and Futatsugi, Akira and Mikoshiba, Katsuhiko and Frotscher, Michael and Ryuichi Shigemoto}, journal = {European Journal of Neuroscience}, number = {8}, pages = {2169 -- 2178}, publisher = {Wiley-Blackwell}, title = {{Immunocytochemical localization of the α1A subunit of the P/Q-type calcium channel in the rat cerebellum}}, doi = {10.1111/j.0953-816X.2004.03319.x}, volume = {19}, year = {2004}, } @article{2640, abstract = {Hyperpolarization-activated cation currents (Ih) contribute to various physiological properties and functions in the brain, including neuronal pacemaker activity, setting of resting membrane potential, and dendritic integration of synaptic input. Four subunits of the Hyperpolarization-activated and Cyclic-Nucleotide-gated nonselective cation channels (HCN1-4), which generate Ih, have been cloned recently. To better understand the functional diversity of Ih in the brain, we examined precise immunohistochemical localization of four HCNs in the rat brain. Immunoreactivity for HCN1 showed predominantly cortical distribution, being intense in the neocortex, hippocampus, superior colliculus, and cerebellum, whereas those for HCN3 and HCN4 exhibited subcortical distribution mainly concentrated in the hypothalamus and thalamus, respectively. Immunoreactivity for HCN2 had a widespread distribution throughout the brain. Double immunofluorescence revealed colocalization of immunoreactivity for HCN1 and HCN2 in distal dendrites of pyramidal cells in the hippocampus and neocortex. At the electron microscopic level, immunogold particles for HCN1 and HCN2 had similar distribution patterns along plasma membrane of dendritic shafts in layer I of the neocortex and stratum lacunosum moleculare of the hippocampal CA1 area, suggesting that these subunits could form heteromeric channels. Our results further indicate that HCNs are localized not only in somato-dendritic compartments but also in axonal compartments of neurons. Immunoreactivity for HCNs often occurred in preterminal rather than terminal portions of axons and in specific populations of myelinated axons. We also found HCN2-immunopositive oligodendrocytes including perineuronal oligodendrocytes throughout the brain. These results support previous electrophysiological findings and further suggest unexpected roles of Ih channels in the brain.}, author = {Notomi, Takuya and Ryuichi Shigemoto}, journal = {Journal of Comparative Neurology}, number = {3}, pages = {241 -- 276}, publisher = {Wiley-Blackwell}, title = {{Immunohistochemical localization of Ih channel subunits, HCN1-4, in the rat brain}}, doi = {10.1002/cne.11039}, volume = {471}, year = {2004}, } @article{2641, abstract = {The Na+-K+ pump current (Ip) and the h-current (Ih) flowing through hyperpolarization-activated channels (h-channels) participate in generating the resting potential. These two currents are thought to be produced independently. We show here bidirectional interactions between Na+-K+ pumps and h-channels in mesencephalic trigeminal neurons. Activation of Ih leads to the generation of two types of ouabain-sensitive Ip with temporal profiles similar to those of instantaneous and slow components of I h, presumably reflecting Na+ transients in a restricted cellular space. Moreover, the Ip activated by instantaneous I h can facilitate the subsequent activation of slow Ih. Such counteractive and cooperative interactions were also disclosed by replacing extracellular Na+ with Li+, which is permeant through h-channels but does not stimulate the Na+-K+ pump as strongly as Na+ ions. These observations indicate that the interactions are bidirectional and mediated by Na+ ions. Also after substitution of extracellular Na+ with Li+, the tail Ih was reduced markedly despite an enhancement of Ih itself, attributable to a negative shift of the reversal potential for I h presumably caused by intracellular accumulation of Li+ ions. This suggests the presence of a microdomain where the interactions can take place. Thus, the bidirectional interactions between Na+-K + pumps and h-channels are likely to be mediated by Na+ microdomain. Consistent with these findings, hyperpolarization-activated and cyclic nucleotide-modulated subunits (HCN1/2) and the Na+-K + pump α3 isoform were colocalized in plasma membrane of mesencephalic trigeminal neurons having numerous spines.}, author = {Kang, Youngnam and Notomi, Takuya and Saito, Mitsuru and Zhang, Wei and Ryuichi Shigemoto}, journal = {Journal of Neuroscience}, number = {14}, pages = {3694 -- 3702}, publisher = {Society for Neuroscience}, title = {{Bidirectional interactions between H-channels and Na+-K + pumps in mesencephalic trigeminal neurons}}, doi = {10.1523/JNEUROSCI.5641-03.2004}, volume = {24}, year = {2004}, } @misc{2636, author = {Momiyama, Akiko and Ryuichi Shigemoto}, booktitle = {Tanpakushitsu kakusan koso Protein nucleic acid enzyme}, number = {3 Suppl}, pages = {287 -- 294}, publisher = {Kyoritsu Shuppan}, title = {{Function and distribution of glutamate receptors in the central synapses}}, volume = {49}, year = {2004}, } @article{2645, abstract = {The globus pallidus (GP) is a critical component of the basal ganglia circuitry controlling motor behavior. Dysregulation of GP activity has been implicated in a number of psychomotor disorders, including Parkinson's disease (PD), in which a cardinal feature of the pathophysiology is an alteration in the pattern and synchrony of discharge in GP neurons. Yet the determinants of this activity in GP neurons are poorly understood. To help fill this gap, electrophysiological, molecular, and computational approaches were used to identify and characterize GABAergic GP neurons in tissue slices from rodents. In vitro, GABAergic GP neurons generate a regular, autonomous, single-spike pacemaker activity. Hyperpolarization-activated, cyclic nucleotide-gated cation (HCN) channels make an important contribution to this process: their blockade with ZD7288 significantly slowed discharge rate and decreased its regularity. HCN currents evoked by somatic voltage clamp had fast and slow components. Single-cell RT-PCR and immunohistochemical approaches revealed robust expression of HCN2 subunits as well as significant levels of HCN1 subunits in GABAergic GP neurons. Transient activation of striatal GABAergic input to GP neurons led to a resetting of rhythmic discharge that was dependent on HCN currents. Simulations suggested that the ability of transient striatal GABAergic input to reset pacemaking was dependent on dendritic HCN2/HCN1 channels. Together, these studies show that HCN channels in GABAergic GP neurons are key determinants of the regularity and rate of pacemaking as well as striatal resetting of this activity, implicating HCN channels in the emergence of synchrony in PD.}, author = {Chan, Savio and Ryuichi Shigemoto and Mercer, Jeff N and Surmeier, James D}, journal = {Journal of Neuroscience}, number = {44}, pages = {9921 -- 9932}, publisher = {Society for Neuroscience}, title = {{HCN2 and HCN1 channels govern the regularity of autonomous pacemaking and synaptic resetting in globus pallidus neurons}}, doi = {10.1523/JNEUROSCI.2162-04.2004}, volume = {24}, year = {2004}, } @article{2644, abstract = {The release of GABA in synapses is modulated by presynaptic metabotropic glutamate receptors (mGluRs). We tested whether GABA release to identified hippocampal neurons is influenced by group III mGluR activation using the agonist L-(+)-2-amino-4-phosphonobutyric acid (L-AP4) on inhibitory postsynaptic currents (IPSCs) evoked in CA1 interneurons and pyramidal cells. In interneurons, characterized with biocytin and immunolabelling for somatostatin, evoked IPSCs were depressed by 50 μM L-AP4 (activating mGluR4 and 8) to 68±6% of control, but they were rarely depressed in pyramidal cells (96±4% of control). At 300-500 μM concentration (activating mGluR4, 7 and 8), L-AP4 depressed IPSCs in both interneurons (to 70±6%) and pyramidal cells (to 67±4%). The change in trial-to-trial variability and in paired-pulse depression indicated a presynaptic action. In interneurons, the degree of IPSC depression was variable (to 9-87%), and a third of IPSCs were not affected by L-AP4. The L-AP4-evoked IPSC depression was blocked by LY341495. The depression of IPSCs was similar in O-LM cells and other interneurons. The lack of cell-type selectivity and the similar efficacy of different concentrations of L-AP4 suggest that several group III mGluRs are involved in the depression of IPSCs. Electron microscopic immunocytochemistry confirmed that mGluR4, mGluR7a and mGluR8a occur in the presynaptic active zone of GABAergic terminals on interneurons, but not on those innervating pyramidal cells. The high variability of L-AP4-evoked IPSC suppression is in line with the selective expression of presynaptic mGluRs by several distinct types of GABAergic neuron innervating each interneuron type.}, author = {Kogo, Naoki and Dalezios, Yannis and Capogna,Marco and Ferraguti, Francesco and Ryuichi Shigemoto and Somogyi, Péter}, journal = {European Journal of Neuroscience}, number = {10}, pages = {2727 -- 2740}, publisher = {Wiley-Blackwell}, title = {{Depression of GABAergic input to identified hippocampal neurons by group III metabotropic glutamate receptors in the rat}}, doi = {10.1111/j.0953-816X.2004.03394.x}, volume = {19}, year = {2004}, } @article{2646, abstract = {Metabotropic γ-aminobutyric acid receptors (GABAB) play modulatory roles in central synaptic transmission and are involved in controlling neuronal migration during development. We used immunohistochemical methods to elucidate the expression pattern as well as the cellular and the precise subcellular localization of the GABAB1a/b and GABAB2 subunits in the rat hippocampus during prenatal and postnatal development. At the light microscopic level, both GABABB1a/b and GABAB2 were expressed in the hippocampal primordium from embryonic day E14. During postnatal development, immunoreactivity for GABAB1a/b and GABAB2 was distributed mainly in pyramidal cells, with discrete GABABB1a/b-immunopositive cell bodies of interneurons present throughout the hippocampus. Using double immunofluorescence, we demonstrated that during the second week of postnatal development, GABAB1a/b but not GABAB2 was expressed in glial cells throughout the hippocampal formation. At the electron microscopic level, GABAB1a/b and GABAB2 showed a similar distribution pattern during postnatal development. Thus, at all ages the two receptor subunits were located postsynaptically in dendritic spines and shafts at extrasynaptic and perisynaptic sites in both pyramidal and nonpyramidal cells. We further demonstrated that the two subunits were localized presynaptically along the extrasynaptic plasma membrane of axon terminals and along the presynaptic active zone in both asymmetrical and, to a lesser extent, symmetrical synapses. These results suggest that GABAB receptors are widely expressed in the hippocampus throughout development and that GABABB1a/b and GABAB2 form both pre- and postsynaptic receptors.}, author = {López-Bendito, Guillermina and Ryuichi Shigemoto and Kulik, Ákos and Vida, Imre and Fairén, Alfonso and Luján, Rafael}, journal = {Hippocampus}, number = {7}, pages = {836 -- 848}, publisher = {Wiley-Blackwell}, title = {{ Distribution of metabotropic GABA receptor subunits GABAB1a/b and GABAB2 in the rat hippocampus during prenatal and postnatal development}}, doi = {10.1002/hipo.10221}, volume = {14}, year = {2004}, } @article{2706, abstract = {The Pauli operator describes the energy of a nonrelativistic quantum particle with spin in a magnetic field and an external potential. Bounds on the sum of the negative eigenvalues are called magnetic Lieb-Thirring (MLT) inequalities. The purpose of this paper is twofold. First, we prove a new MLT inequality in a simple way. Second, we give a short summary of our recent proof of a more refined MLT inequality(8) and we explain the differences between the two results and methods. The main feature of both estimates, compared to earlier results, is that in the large field regime they grow with the optimal (first) power of the strength of the magnetic field. As a byproduct of the method, we also obtain optimal upper bounds on the pointwise density of zero energy eigenfunctions of the Dirac operator.}, author = {László Erdös and Solovej, Jan P}, journal = {Journal of Statistical Physics}, number = {1-4}, pages = {475 -- 506}, publisher = {Springer}, title = {{Magnetic Lieb-Thirring inequalities with optimal dependence on the field strength}}, doi = {10.1023/B:JOSS.0000037216.45270.1d}, volume = {116}, year = {2004}, } @article{2707, abstract = {We give a nonrigorous derivation of the nonlinear Boltzmann equation from the Schrödinger evolution of interacting fermions. The argument is based mainly on the assumption that a quasifree initial state satisfies a property called restricted quasifreeness in the weak coupling limit at any later time. By definition, a state is called restricted quasifree if the four-point and the eight-point functions of the state factorize in the same manner as in a quasifree state.}, author = {László Erdös and Salmhofer, Manfred and Yau, Horng-Tzer}, journal = {Journal of Statistical Physics}, number = {1-4}, pages = {367 -- 380}, publisher = {Springer}, title = {{On the quantum Boltzmann equation}}, doi = {10.1023/B:JOSS.0000037224.56191.ed}, volume = {116}, year = {2004}, } @article{2741, abstract = {The Pauli operator describes the energy of a nonrelativistic quantum particle with spin 1/2 in a magnetic field and an external potential. A new Lieb-Thirring type inequality on the sum of the negative eigenvalues is presented. The main feature compared to earlier results is that in the large field regime the present estimate grows with the optimal (first) power of the strength of the magnetic field. As a byproduct of the method, we also obtain an optimal upper bound on the pointwise density of zero energy eigenfunctions of the Dirac operator. The main technical tools are: (i) a new localization scheme for the square of the resolvent of a general class of second order elliptic operators; (ii) a geometric construction of a Dirac operator with a constant magnetic field that approximates the original Dirac operator in a tubular neighborhood of a fixed field line. The errors may depend on the regularity of the magnetic field but they are uniform in the field strength.}, author = {László Erdös and Solovej, Jan P}, journal = {Annales Henri Poincare}, number = {4}, pages = {671 -- 741}, publisher = {Birkhäuser}, title = {{Uniform Lieb-Thirring inequality for the three-dimensional Pauli operator with a strong non-homogeneous magnetic field}}, doi = {10.1007/s00023-004-0180-x}, volume = {5}, year = {2004}, } @article{2742, abstract = {We consider a system of N weakly interacting fermions with a real analytic pair interaction. We prove that for a general class of initial data there exists a fixed time T such that the difference between the one particle density matrix of this system and the solution of the nonlinear Hartree equation is of order N−1 for any time t⩽T.}, author = {Elgart, Alexander and László Erdös and Schlein, Benjamin and Yau, Horng-Tzer}, journal = {Journal de Mathématiques Pures et Appliquées}, number = {10}, pages = {1241 -- 1273}, publisher = {Elsevier}, title = {{Nonlinear Hartree equation as the mean field limit of weakly coupled fermions}}, doi = {10.1016/j.matpur.2004.03.006}, volume = {83}, year = {2004}, } @article{2787, abstract = {The results of experimental and numerical investigations of the onset of oscillatory convection in a sidewall heated rectangular cavity of molten gallium are reported. Detailed comparisons are made between experimental observations and calculations from numerical simulations of a three-dimensional Boussinesq model. The onset of time-dependence takes place through supercritical Hopf bifurcations and the loci of critical points in the (Gr, Pr)-plane are qualitatively similar with excellent agreement between the frequencies of the oscillatory motion. This provides a severe test of the control of the experiment since the mode of oscillation is extremely sensitive to imperfections. Detailed numerical investigations reveal that there are a pair of Hopf bifurcations which exist on two asymmetric states which themselves arise at a subcritical pitchfork from the symmetric state. There is no evidence for this in the experiment and this qualitative difference is attributed to non-Boussinesq perturbations which increase with Gr. However, the antisymmetric spatial structure of the oscillatory state is robust and is present in both the experiment and the numerical model. Moreover, the detailed analysis of the numerical results reveals the origins of the oscillatory instability.}, author = {Björn Hof and Juel, Anne and Zhao, Li and Henry, Daniel and Ben Hadid, Hamda and Mullin, Tom P}, journal = {Journal of Fluid Mechanics}, pages = {391 -- 413}, publisher = {Cambridge University Press}, title = {{On the onset of oscillatory convection in molten gallium}}, doi = {10.1017/S0022112004000527}, volume = {515}, year = {2004}, } @article{2786, abstract = {Transition to turbulence in pipe flow is one of the most fundamental and longest- standing problems in fluid dynamics. Stability theory suggests that the flow remains laminar for all flow rates, but in practice pipe flow becomes turbulent even at moderate speeds. This transition drastically affects the transport efficiency of mass, momentum, and heat. On the basis of the recent discovery of unstable traveling waves in computational studies of the Navier-Stokes equations and ideas from dynamical systems theory, a model for the transition process has been suggested. We report experimental observation of these traveling waves in pipe flow, confirming the proposed transition scenario and suggesting that the dynamics associated with these unstable states may indeed capture the nature of fluid turbulence.}, author = {Björn Hof and van Doorne, Casimir W and Westerweel, Jerry and Nieuwstadt, Frans T and Faisst, Holger and Eckhardt, Bruno and Wedin, Håkan and Kersweli, Richard R and Waleffe, Fabian}, journal = {Science}, number = {5690}, pages = {1594 -- 1598}, publisher = {American Association for the Advancement of Science}, title = {{Experimental observation of nonlinear traveling waves in turbulent pipe flow}}, doi = {10.1126/science.1100393}, volume = {305}, year = {2004}, } @article{2998, abstract = {The packaging of the genomic DNA into chromatin in the cell nucleus requires machineries that facilitate DNA-dependent processes such as transcription in the presence of repressive chromatin structures. Using co-immunoprecipitation we have identified in Arabidopsis thaliana cells the FAcilitates Chromatin Transcription (FACT) complex, consisting of the 120-kDa Spt16 and the 71-kDa SSRP1 proteins. Indirect immunofluorecence analyses revealed that both FACT subunits co-localize to nuclei of the majority of cell types in embryos, shoots and roots, whereas FACT is not present in terminally differentiated cells such as mature trichoblasts or cells of the root cap. In the nucleus, Spt16 and SSRP1 are found in the cytologically defined euchromatin of interphase cells independent of the status of DNA replication, but the proteins are not associated with heterochromatic chromocentres and condensed mitotic chromosomes. FACT can be detected by chromatin immunoprecipitation over the entire transcribed region (5′-UTR, coding sequence, 3′-UTR) of actively transcribed genes, whereas it does not occur at transcriptionally inactive heterochromatic regions and intergenic regions. FACT localizes to inducible genes only after induction of transcription, and the association of the complex with the genes correlates with the level of transcription. Collectively, these results indicate that FACT assists transcription elongation through plant chromatin.}, author = {Duroux, Meg and Houben, Andreas and Růžička, Kamil and Jirí Friml and Grasser, Klaus D}, journal = {Plant Journal}, number = {5}, pages = {660 -- 671}, publisher = {Wiley-Blackwell}, title = {{The chromatin remodelling complex FACT associates with actively transcribed regions of the Arabidopsis genome}}, doi = {10.1111/j.1365-313X.2004.02242.x}, volume = {40}, year = {2004}, } @article{2997, abstract = {Polar transport-dependent local accumulation of auxin provides positional cues for multiple plant patterning processes. This directional auxin flow depends on the polar subcellular localization of the PIN auxin efflux regulators. Overexpression of the PINOID protein kinase induces a basal-to-apical shift in PIN localization, resulting in the loss of auxin gradients and strong defects in embryo and seedling roots. Conversely, pid loss of function induces an apical-to-basal shift in PIN1 polar targeting at the inflorescence apex, accompanied by defective organogenesis. Our results show that a PINOID-dependent binary switch controls PIN polarity and mediates changes in auxin flow to create local gradients for patterning processes.}, author = {Jirí Friml and Yang, Xiong and Michniewicz, Marta and Weijers, Dolf and Quint, Ab and Tietz, Olaf and Benjamins, René and Ouwerkerk, Pieter B and Ljung, Karin and Sandberg, Göran and Hooykaas, Paul J and Palme, Klaus and Offringa, Remko}, journal = {Science}, number = {5697}, pages = {862 -- 865}, publisher = {American Association for the Advancement of Science}, title = {{A PINOID-dependent binary switch in apical-basal PIN polar targeting directs auxin efflux}}, doi = {10.1126/science.1100618}, volume = {306}, year = {2004}, } @article{2999, abstract = {Embryogenesis of flowering plants establishes a basic body plan with apical-basal, radial and bilateral patterns from the single-celled zygote. Arabidopsis embryogenesis exhibits a nearly invariant cell division pattern and therefore is an ideal system for studies of early plant development. However, plant embryos are difficult to access for experimental manipulation, as they develop deeply inside maternal tissues. Here we present a method for the culture of zygotic Arabidopsis embryos in vitro. The technique omits excision of the embryo by culturing the entire ovule, thus greatly facilitating the time and effort involved. It enables external manipulation of embryo development and culture from the earliest developmental stages up to maturity. Administration of various chemical treatments as well as the use of different molecular markers is demonstrated together with standard techniques for visualizing gene expression and protein localization in in vitro cultivated embryos. The presented set of techniques allows for so far unavailable molecular physiology approaches in the study of early plant development.}, author = {Sauer, Michael and Jirí Friml}, journal = {Plant Journal}, number = {5}, pages = {835 -- 843}, publisher = {Wiley-Blackwell}, title = {{In vitro culture of Arabidopsis embryos within their ovules}}, doi = {10.1111/j.1365-313X.2004.02248.x}, volume = {40}, year = {2004}, } @inproceedings{3208, abstract = {A new technique for proving the adaptive indistinguishability of two systems, each composed of some component systems, is presented, using only the fact that corresponding component systems are non-adaptively indistinguishable. The main tool is the definition of a special monotone condition for a random system F, relative to another random system G, whose probability of occurring for a given distinguisher D is closely related to the distinguishing advantage ε of D for F and G, namely it is lower and upper bounded by ε and (1+ln1), respectively. A concrete instantiation of this result shows that the cascade of two random permutations (with the second one inverted) is indistinguishable from a uniform random permutation by adaptive distinguishers which may query the system from both sides, assuming the components’ security only against non-adaptive one-sided distinguishers. As applications we provide some results in various fields as almost k-wise independent probability spaces, decorrelation theory and computational indistinguishability (i.e., pseudo-randomness).}, author = {Maurer, Ueli M and Krzysztof Pietrzak}, pages = {410 -- 427}, publisher = {Springer}, title = {{Composition of random systems: When two weak make one strong}}, doi = {10.1007/978-3-540-24638-1_23}, volume = {2951}, year = {2004}, } @inbook{3587, author = {Ulrich, Florian and Heisenberg, Carl-Philipp J}, booktitle = {Fish development and genetics : the zebrafish and medaka models}, editor = {Korzh, Vladimir and Gong, Zhiyuan}, pages = {39 -- 86}, publisher = {World Scientific Publishing}, title = {{Gastrulation in zebrafish}}, volume = {2}, year = {2004}, } @article{3617, abstract = {The coalescent process can describe the effects of selection at linked loci only if selection is so strong that genotype frequencies evolve deterministically. Here, we develop methods proposed by Kaplan, Darden, and Hudson to find the effects of weak selection. We show that the overall effect is given by an extension to Price's equation: the change in properties such as moments of coalescence times is equal to the covariance between those properties and the fitness of the sample of genes. The distribution of coalescence times differs substantially between allelic classes, even in the absence of selection. However, the average coalescence time between randomly chosen genes is insensitive to the current allele frequency and is affected significantly by purifying selection only if deleterious mutations are common and selection is strong (i.e., the product of population size and selection coefficient, Ns > 3). Balancing selection increases mean coalescence times, but the effect becomes large only when mutation rates between allelic classes are low and when selection is extremely strong. Our analysis supports previous simulations that show that selection has surprisingly little effect on genealogies. Moreover, small fluctuations in allele frequency due to random drift can greatly reduce any such effects. This will make it difficult to detect the action of selection from neutral variation alone.}, author = {Nicholas Barton and Etheridge, Alison M}, journal = {Genetics}, number = {2}, pages = {1115 -- 1131}, publisher = {Genetics Society of America}, title = {{The effect of selection on genealogies}}, doi = {10.1534/genetics.166.2.1115}, volume = {166}, year = {2004}, }