TY - JOUR
AB - The third EMBO Conference on Plant Molecular Biology, which focused on ‘Plant development and environmental interactions’,was held in May 2012 in Matera, Italy. Here, we review some of the topics and themes that emerged from the various contributions; namely, steering technologies, transcriptional networks and hormonal regulation, small RNAs, cell and tissue polarity, environmental control and natural variation. We intend to provide the reader who might have missed this remarkable event with a glimpse of the recent progress made in this blossoming research field.
AU - Beeckman, Tom
AU - Friml, Jirí
ID - 2456
IS - 20
JF - Development
TI - Plant developmental biologists meet on stairways in Matera
VL - 139
ER -
TY - JOUR
AB - Initiation and successive development of organs induce mechanical stresses at the cellular level. Using the tomato shoot apex, a new study now proposes that mechanical strain regulates the plasma membrane abundance of the PIN1 auxin transporter, thereby reinforcing a positive feed-back loop between growth and auxin accumulation.
AU - Li, Hongjiang
AU - Friml, Jirí
AU - Grunewald, Wim
ID - 2458
IS - 16
JF - Current Biology
TI - Cell polarity: Stretching prevents developmental cramps
VL - 22
ER -
TY - JOUR
AB - Coordinated, subcellular trafficking of proteins is one of the fundamental properties of the multicellular eukaryotic organisms. Trafficking involves a large diversity of compartments, pathways, cargo molecules, and vesicle-sorting events. It is also crucial in regulating the localization and, thus, the activity of various proteins, but the process is still poorly genetically defined in plants. In the past, forward genetics screens had been used to determine the function of genes by searching for a specific morphological phenotype in the organism population in which mutations had been induced chemically or by irradiation. Unfortunately, these straightforward genetic screens turned out to be limited in identifying new regulators of intracellular protein transport, because mutations affecting essential trafficking pathways often lead to lethality. In addition, the use of these approaches has been restricted by functional redundancy among trafficking regulators. Screens for mutants that rely on the observation of changes in the cellular localization or dynamics of fluorescent subcellular markers enable, at least partially, to circumvent these issues. Hence, such image-based screens provide the possibility to identify either alleles with weak effects or components of the subcellular trafficking machinery that have no strong impact on the plant growth.
AU - Zwiewka, Marta
AU - Friml, Jirí
ID - 2459
IS - May
JF - Frontiers in Plant Science
TI - Fluorescence imaging-based forward genetic screens to identify trafficking regulators in plants
VL - 3
ER -
TY - JOUR
AB - Interneurons are critical for neuronal circuit function, but how their dendritic morphologies and membrane properties influence information flow within neuronal circuits is largely unknown. We studied the spatiotemporal profile of synaptic integration and short-term plasticity in dendrites of mature cerebellar stellate cells by combining two-photon guided electrical stimulation, glutamate uncaging, electron microscopy, and modeling. Synaptic activation within thin (0.4 μm) dendrites produced somatic responses that became smaller and slower with increasing distance from the soma, sublinear subthreshold input-output relationships, and a somatodendritic gradient of short-term plasticity. Unlike most studies showing that neurons employ active dendritic mechanisms, we found that passive cable properties of thin dendrites determine the sublinear integration and plasticity gradient, which both result from large dendritic depolarizations that reduce synaptic driving force. These integrative properties allow stellate cells to act as spatiotemporal filters of synaptic input patterns, thereby biasing their output in favor of sparse presynaptic activity. Stellate cells are critical sources of inhibition in the cerebellum, but how their dendrites integrate excitatory synaptic inputs is unknown. Abrahamsson et al. show that thin dendrites and passive membrane properties of SCs promote sublinear synaptic summation and distance-dependent short-term plasticity.
AU - Abrahamsson, Therese
AU - Cathala, Laurence
AU - Matsui, Ko
AU - Ryuichi Shigemoto
AU - DiGregorio, David A
ID - 2474
IS - 6
JF - Neuron
TI - Thin dendrites of cerebellar interneurons confer sublinear synaptic integration and a gradient of short-term plasticity
VL - 73
ER -
TY - JOUR
AB - Background: One of the best-characterized causative factors of Alzheimer's disease (AD) is the generation of amyloid-β peptide (Aβ). AD subjects are at high risk of epileptic seizures accompanied by aberrant neuronal excitability, which in itself enhances Aβ generation. However, the molecular linkage between epileptic seizures and Aβ generation in AD remains unclear. Results: X11 and X11-like (X11L) gene knockout mice suffered from epileptic seizures, along with a malfunction of hyperpolarization-activated cyclic nucleotide gated (HCN) channels. Genetic ablation of HCN1 in mice and HCN1 channel blockage in cultured Neuro2a (N2a) cells enhanced Aβ generation. Interestingly, HCN1 levels dramatically decreased in the temporal lobe of cynomolgus monkeys (Macaca fascicularis) during aging and were significantly diminished in the temporal lobe of sporadic AD patients. Conclusion: Because HCN1 associates with amyloid-β precursor protein (APP) and X11/X11L in the brain, genetic deficiency of X11/X11L may induce aberrant HCN1 distribution along with epilepsy. Moreover, the reduction in HCN1 levels in aged primates may contribute to augmented Aβ generation. Taken together, HCN1 is proposed to play an important role in the molecular linkage between epileptic seizures and Aβ generation, and in the aggravation of sporadic AD.
AU - Saito, Yuhki
AU - Inoue, Tsuyoshi
AU - Zhu, Gang
AU - Kimura, Naoki
AU - Okada, Motohiro
AU - Nishimura, Masaki
AU - Murayama, Shigeo
AU - Kaneko, Sunao
AU - Ryuichi Shigemoto
AU - Imoto, Keiji
AU - Suzuki, Toshiharu
ID - 2475
IS - 1
JF - Molecular Neurodegeneration
TI - Hyperpolarization-activated cyclic nucleotide gated channels: A potential molecular link between epileptic seizures and Aβ generation in Alzheimer's disease
VL - 7
ER -
TY - JOUR
AB - Recently developed pharmacogenetic and optogenetic approaches, with their own advantages and disadvantages, have become indispensable tools in modern neuroscience. Here, we employed a previously described knock-in mouse line (GABA ARγ2 77Ilox) in which the γ2 subunit of the GABA A receptor (GABA AR) was mutated to become zolpidem insensitive (γ2 77I) and used viral vectors to swap γ2 77I with wild-type, zolpidem-sensitive γ2 subunits (γ2 77F). The verification of unaltered density and subcellular distribution of the virally introduced γ2 subunits requires their selective labelling. For this we generated six N- and six C-terminal-tagged γ2 subunits, with which cortical cultures of GABA ARγ2 -/- mice were transduced using lentiviruses. We found that the N-terminal AU1 tag resulted in excellent immunodetection and unimpaired synaptic localization. Unaltered kinetic properties of the AU1-tagged γ2 ( AU1γ2 77F) channels were demonstrated with whole-cell patch-clamp recordings of spontaneous IPSCs from cultured cells. Next, we carried out stereotaxic injections of lenti- and adeno-associated viruses containing Cre-recombinase and the AU1γ2 77F subunit (Cre-2A- AU1γ2 77F) into the neocortex of GABA ARγ2 77Ilox mice. Light microscopic immunofluorescence and electron microscopic freeze-fracture replica immunogold labelling demonstrated the efficient immunodetection of the AU1 tag and the normal enrichment of the AU1γ2 77F subunits in perisomatic GABAergic synapses. In line with this, miniature and action potential-evoked IPSCs whole-cell recorded from transduced cells had unaltered amplitudes, kinetics and restored zolpidem sensitivity. Our results obtained with a wide range of structural and functional verification methods reveal unaltered subcellular distributions and functional properties of γ2 77I and AU1γ2 77F GABA ARs in cortical pyramidal cells. This transgenic-viral pharmacogenetic approach has the advantage that it does not require any extrinsic protein that might endow some unforeseen alterations of the genetically modified cells. In addition, this virus-based approach opens up the possibility of modifying multiple cell types in distinct brain regions and performing alternative recombination-based intersectional genetic manipulations.
AU - Sümegi, Máté
AU - Fukazawa, Yugo
AU - Matsui, Ko
AU - Lörincz, Andrea
AU - Eyre, Mark D
AU - Nusser, Zoltán
AU - Ryuichi Shigemoto
ID - 2476
IS - 7
JF - Journal of Physiology
TI - Virus-mediated swapping of zolpidem-insensitive with zolpidem-sensitive GABA A receptors in cortical pyramidal cells
VL - 590
ER -
TY - JOUR
AB - Dynamic activity of glia has repeatedly been demonstrated, but if such activity is independent from neuronal activity, glia would not have any role in the information processing in the brain or in the generation of animal behavior. Evidence for neurons communicating with glia is solid, but the signaling pathway leading back from glial-to-neuronal activity was often difficult to study. Here, we introduced a transgenic mouse line in which channelrhodopsin-2, a light-gated cation channel, was expressed in astrocytes. Selective photostimulation of these astrocytes in vivo triggered neuronal activation. Using slice preparations, we show that glial photostimulation leads to release of glutamate, which was sufficient to activate AMPA receptors on Purkinje cells and to induce long-term depression of parallel fiber-to-Purkinje cell synapses through activation of metabotropic glutamate receptors. In contrast to neuronal synaptic vesicular release, glial activation likely causes preferential activation of extrasynaptic receptors that appose glial membrane. Finally, we show that neuronal activation by glial stimulation can lead to perturbation of cerebellar modulated motor behavior. These findings demonstrate that glia can modulate the tone of neuronal activity and behavior. This animal model is expected to be a potentially powerful approach to study the role of glia in brain function.
AU - Sasaki, Takuya
AU - Beppu, Kaoru
AU - Tanaka, Kenji F
AU - Fukazawa, Yugo
AU - Ryuichi Shigemoto
AU - Matsui, Ko
ID - 2477
IS - 50
JF - PNAS
TI - Application of an optogenetic byway for perturbing neuronal activity via glial photostimulation
VL - 109
ER -
TY - JOUR
AB - Visual information must be relayed through the lateral geniculate nucleus before it reaches the visual cortex. However, not all spikes created in the retina lead to postsynaptic spikes and properties of the retinogeniculate synapse contribute to this filtering. To understand the mechanisms underlying this filtering process, we conducted electrophysiology to assess the properties of signal transmission in the Long-Evans rat. We also performed SDS-digested freeze-fracture replica labeling to quantify the receptor and transporter distribution, as well as EM reconstruction to describe the 3D structure. To analyze the impact of transmitter diffusion on the activity of the receptors, simulations were integrated. We identified that a large contributor to the filtering is the marked paired-pulse depression at this synapse, which was intensified by the morphological characteristics of the contacts. The broad presynaptic and postsynaptic contact area restricts transmitter diffusion two dimensionally. Additionally, the presence of multiple closely arranged release sites invites intersynaptic spillover, which causes desensitization of AMPA receptors. The presence of AMPA receptors that slowly recover from desensitization along with the high presynaptic release probability and multivesicular release at each synapse also contribute to the depression. These features contrast with many other synapses where spatiotemporal spread of transmitter is limited by rapid transmitter clearance allowing synapses to operate more independently. We propose that the micrometer-order structure can ultimately affect the visual information processing.
AU - Budisantoso, Timotheus
AU - Matsui, Ko
AU - Kamasawa, Naomi
AU - Fukazawa, Yugo
AU - Ryuichi Shigemoto
ID - 2514
IS - 7
JF - Journal of Neuroscience
TI - Mechanisms underlying signal filtering at a multisynapse contact
VL - 32
ER -
TY - JOUR
AB - We investigated the temporal and spatial expression of SK2 in the developing mouse hippocampus using molecular and biochemical techniques, quantitative immunogold electron microscopy, and electrophysiology. The mRNA encoding SK2 was expressed in the developing and adult hippocampus. Western blotting and immunohistochemistry showed that SK2 protein increased with age. This was accompanied by a shift in subcellular localization. Early in development (P5), SK2 was predominantly localized to the endoplasmic reticulum in the pyramidal cell layer. But by P30 SK2 was almost exclusively expressed in the dendrites and spines. The level of SK2 at the postsynaptic density (PSD) also increased during development. In the adult, SK2 expression on the spine plasma membrane showed a proximal-to-distal gradient. Consistent with this redistribution and gradient of SK2, the selective SK channel blocker apamin increased evoked excitatory postsynaptic potentials (EPSPs) only in CA1 pyramidal neurons from mice older than P15. However, the effect of apamin on EPSPs was not different between synapses in proximal or distal stratum radiatum or stratum lacunosum-moleculare in adult. These results show a developmental increase and gradient in SK2-containing channel surface expression that underlie their influence on neurotransmission, and that may contribute to increased memory acquisition during early development.
AU - Ballesteros-Merino, Carmen
AU - Lin, Michael
AU - Wu, Wendy W
AU - Ferrándiz-Huertas, Clotilde
AU - Cabañero, María José
AU - Watanabe, Masahiko
AU - Fukazawa, Yugo
AU - Ryuichi Shigemoto
AU - Maylie, James G
AU - Adelman, John P
AU - Luján, Rafael
ID - 2515
IS - 6
JF - Hippocampus
TI - Developmental profile of SK2 channel expression and function in CA1 neurons
VL - 22
ER -
TY - JOUR
AB - Carbon has been used widely as the basis of porous cathodes for nonaqueous Li–O2 cells. However, the stability of carbon and the effect of carbon on electrolyte decomposition in such cells are complex and depend on the hydrophobicity/hydrophilicity of the carbon surface. Analyzing carbon cathodes, cycled in Li–O2 cells between 2 and 4 V, using acid treatment and Fenton’s reagent, and combined with differential electrochemical mass spectrometry and FTIR, demonstrates the following: Carbon is relatively stable below 3.5 V (vs Li/Li+) on discharge or charge, especially so for hydrophobic carbon, but is unstable on charging above 3.5 V (in the presence of Li2O2), oxidatively decomposing to form Li2CO3. Direct chemical reaction with Li2O2 accounts for only a small proportion of the total carbon decomposition on cycling. Carbon promotes electrolyte decomposition during discharge and charge in a Li–O2 cell, giving rise to Li2CO3 and Li carboxylates (DMSO and tetraglyme electrolytes). The Li2CO3 and Li carboxylates present at the end of discharge and those that form on charge result in polarization on the subsequent charge. Li2CO3 (derived from carbon and from the electrolyte) as well as the Li carboxylates (derived from the electrolyte) decompose and form on charging. Oxidation of Li2CO3 on charging to ∼4 V is incomplete; Li2CO3 accumulates on cycling resulting in electrode passivation and capacity fading. Hydrophilic carbon is less stable and more catalytically active toward electrolyte decomposition than carbon with a hydrophobic surface. If the Li–O2 cell could be charged at or below 3.5 V, then carbon may be relatively stable, however, its ability to promote electrolyte decomposition, presenting problems for its use in a practical Li–O2 battery. The results emphasize that stable cycling of Li2O2 at the cathode in a Li–O2 cell depends on the synergy between electrolyte and electrode; the stability of the electrode and the electrolyte cannot be considered in isolation.
AU - Ottakam Thotiyl, Muhammed M.
AU - Freunberger, Stefan Alexander
AU - Peng, Zhangquan
AU - Bruce, Peter G.
ID - 7308
IS - 1
JF - Journal of the American Chemical Society
SN - 0002-7863
TI - The carbon electrode in nonaqueous Li–O2 cells
VL - 135
ER -
TY - JOUR
AB - Energy‐storage technologies, including electrical double‐layer capacitors and rechargeable batteries, have attracted significant attention for applications in portable electronic devices, electric vehicles, bulk electricity storage at power stations, and “load leveling” of renewable sources, such as solar energy and wind power. Transforming lithium batteries and electric double‐layer capacitors requires a step change in the science underpinning these devices, including the discovery of new materials, new electrochemistry, and an increased understanding of the processes on which the devices depend. The Review will consider some of the current scientific issues underpinning lithium batteries and electric double‐layer capacitors.
AU - Choi, Nam-Soon
AU - Chen, Zonghai
AU - Freunberger, Stefan Alexander
AU - Ji, Xiulei
AU - Sun, Yang-Kook
AU - Amine, Khalil
AU - Yushin, Gleb
AU - Nazar, Linda F.
AU - Cho, Jaephil
AU - Bruce, Peter G.
ID - 7309
IS - 40
JF - Angewandte Chemie International Edition
SN - 1433-7851
TI - Challenges facing Lithium batteries and electrical double-layer capacitors
VL - 51
ER -
TY - JOUR
AB - The rechargeable nonaqueous lithium-air (Li-O2) battery is receiving a great deal of interest because, theoretically, its specific energy far exceeds the best that can be achieved with lithium-ion cells. Operation of the rechargeable Li-O2 battery depends critically on repeated and highly reversible formation/decomposition of lithium peroxide (Li2O2) at the cathode upon cycling. Here, we show that this process is possible with the use of a dimethyl sulfoxide electrolyte and a porous gold electrode (95% capacity retention from cycles 1 to 100), whereas previously only partial Li2O2 formation/decomposition and limited cycling could occur. Furthermore, we present data indicating that the kinetics of Li2O2 oxidation on charge is approximately 10 times faster than on carbon electrodes.
AU - Peng, Z.
AU - Freunberger, Stefan Alexander
AU - Chen, Y.
AU - Bruce, P. G.
ID - 7310
IS - 6094
JF - Science
SN - 0036-8075
TI - A reversible and higher-rate Li-O2 battery
VL - 337
ER -
TY - JOUR
AB - Stability of the electrolyte toward reduced oxygen species generated at the cathode is a crucial challenge for the rechargeable nonaqueous Li–O2 battery. Here, we investigate dimethylformamide as the basis of an electrolyte. Although reactions at the O2 cathode on the first discharge–charge cycle are dominated by reversible Li2O2 formation/decomposition, there is also electrolyte decomposition, which increases on cycling. The products of decomposition at the cathode on discharge are Li2O2, Li2CO3, HCO2Li, CH3CO2Li, NO, H2O, and CO2. Li2CO3 accumulates in the electrode with cycling. The stability of dimethylformamide toward reduced oxygen species is insufficient for its use in the rechargeable nonaqueous Li–O2 battery.
AU - Chen, Yuhui
AU - Freunberger, Stefan Alexander
AU - Peng, Zhangquan
AU - Bardé, Fanny
AU - Bruce, Peter G.
ID - 7311
IS - 18
JF - Journal of the American Chemical Society
SN - 0002-7863
TI - Li–O2 battery with a dimethylformamide electrolyte
VL - 134
ER -
TY - JOUR
AB - Female mate choice acts as an important evolutionary force, yet the influence of the environment on both its expression and the selective pressures acting upon it remains unknown. We found consistent heritable differences between females in their choice of mate based on ornament size during a 25‐year study of a population of collared flycatchers. However, the fitness consequences of mate choice were dependent on environmental conditions experienced whilst breeding. Females breeding with highly ornamented males experienced high relative fitness during dry summer conditions, but low relative fitness during wetter years. Our results imply that sexual selection within a population can be highly variable and dependent upon the prevailing weather conditions experienced by individuals.
AU - Robinson, Matthew Richard
AU - Sander van Doorn, G.
AU - Gustafsson, Lars
AU - Qvarnström, Anna
ID - 7748
IS - 6
JF - Ecology Letters
SN - 1461-023X
TI - Environment-dependent selection on mate choice in a natural population of birds
VL - 15
ER -
TY - JOUR
AB - Although studies on laboratory species and natural populations of vertebrates have shown reproduction to impair later performance, little is known of the age‐specific associations between reproduction and survival, and how such findings apply to the ageing of large, long‐lived species. Herein we develop a framework to examine population‐level patterns of reproduction and survival across lifespan in long‐lived organisms, and decompose those changes into individual‐level effects, and the effects of age‐specific trade‐offs between fitness components. We apply this to an extensive longitudinal dataset on female semi‐captive Asian timber elephants (Elephas maximus) and report the first evidence of age‐specific fitness declines that are driven by age‐specific associations between fitness components in a long‐lived mammal. Associations between reproduction and survival are positive in early life, but negative in later life with up to 71% of later‐life survival declines associated with investing in the production of offspring within this population of this critically endangered species.
AU - Robinson, Matthew Richard
AU - Mar, Khyne U
AU - Lummaa, Virpi
ID - 7749
IS - 3
JF - Ecology Letters
SN - 1461-023X
TI - Senescence and age-specific trade-offs between reproduction and survival in female Asian elephants
VL - 15
ER -
TY - JOUR
AB - We present an analysis of finite-size effects in jammed packings of N soft, frictionless spheres at zero temperature. There is a 1/N correction to the discrete jump in the contact number at the transition so that jammed packings exist only above isostaticity. As a result, the canonical power-law scalings of the contact number and elastic moduli break down at low pressure. These quantities exhibit scaling collapse with a nontrivial scaling function, demonstrating that the jamming transition can be considered a phase transition. Scaling is achieved as a function of N in both two and three dimensions, indicating an upper critical dimension of 2.
AU - Goodrich, Carl Peter
AU - Liu, Andrea J.
AU - Nagel, Sidney R.
ID - 7776
IS - 9
JF - Physical Review Letters
SN - 0031-9007
TI - Finite-size scaling at the jamming transition
VL - 109
ER -
TY - JOUR
AB - Background: Characterizing root system architecture (RSA) is essential to understanding the development and function of vascular plants. Identifying RSA-associated genes also represents an underexplored opportunity for crop improvement. Software tools are needed to accelerate the pace at which quantitative traits of RSA are estimated from images of root networks.Results: We have developed GiA Roots (General Image Analysis of Roots), a semi-automated software tool designed specifically for the high-throughput analysis of root system images. GiA Roots includes user-assisted algorithms to distinguish root from background and a fully automated pipeline that extracts dozens of root system phenotypes. Quantitative information on each phenotype, along with intermediate steps for full reproducibility, is returned to the end-user for downstream analysis. GiA Roots has a GUI front end and a command-line interface for interweaving the software into large-scale workflows. GiA Roots can also be extended to estimate novel phenotypes specified by the end-user.Conclusions: We demonstrate the use of GiA Roots on a set of 2393 images of rice roots representing 12 genotypes from the species Oryza sativa. We validate trait measurements against prior analyses of this image set that demonstrated that RSA traits are likely heritable and associated with genotypic differences. Moreover, we demonstrate that GiA Roots is extensible and an end-user can add functionality so that GiA Roots can estimate novel RSA traits. In summary, we show that the software can function as an efficient tool as part of a workflow to move from large numbers of root images to downstream analysis.
AU - Galkovskyi, Taras
AU - Mileyko, Yuriy
AU - Bucksch, Alexander
AU - Moore, Brad
AU - Symonova, Olga
AU - Price, Charles
AU - Topp, Chrostopher
AU - Iyer Pascuzzi, Anjali
AU - Zurek, Paul
AU - Fang, Suqin
AU - Harer, John
AU - Benfey, Philip
AU - Weitz, Joshua
ID - 492
JF - BMC Plant Biology
TI - GiA Roots: Software for the high throughput analysis of plant root system architecture
VL - 12
ER -
TY - JOUR
AB - The BCI competition IV stands in the tradition of prior BCI competitions that aim to provide high quality neuroscientific data for open access to the scientific community. As experienced already in prior competitions not only scientists from the narrow field of BCI compete, but scholars with a broad variety of backgrounds and nationalities. They include high specialists as well as students.The goals of all BCI competitions have always been to challenge with respect to novel paradigms and complex data. We report on the following challenges: (1) asynchronous data, (2) synthetic, (3) multi-class continuous data, (4) sessionto-session transfer, (5) directionally modulated MEG, (6) finger movements recorded by ECoG. As after past competitions, our hope is that winning entries may enhance the analysis methods of future BCIs.
AU - Tangermann, Michael
AU - Müller, Klaus
AU - Aertsen, Ad
AU - Birbaumer, Niels
AU - Braun, Christoph
AU - Brunner, Clemens
AU - Leeb, Robert
AU - Mehring, Carsten
AU - Miller, Kai
AU - Müller Putz, Gernot
AU - Nolte, Guido
AU - Pfurtscheller, Gert
AU - Preissl, Hubert
AU - Schalk, Gerwin
AU - Schlögl, Alois
AU - Vidaurre, Carmen
AU - Waldert, Stephan
AU - Blankertz, Benjamin
ID - 493
JF - Frontiers in Neuroscience
TI - Review of the BCI competition IV
VL - 6
ER -
TY - JOUR
AB - We solve the longstanding open problems of the blow-up involved in the translations, when possible, of a nondeterministic Büchi word automaton (NBW) to a nondeterministic co-Büchi word automaton (NCW) and to a deterministic co-Büchi word automaton (DCW). For the NBW to NCW translation, the currently known upper bound is 2o(nlog n) and the lower bound is 1.5n. We improve the upper bound to n2n and describe a matching lower bound of 2ω(n). For the NBW to DCW translation, the currently known upper bound is 2o(nlog n). We improve it to 2 o(n), which is asymptotically tight. Both of our upper-bound constructions are based on a simple subset construction, do not involve intermediate automata with richer acceptance conditions, and can be implemented symbolically. We continue and solve the open problems of translating nondeterministic Streett, Rabin, Muller, and parity word automata to NCW and to DCW. Going via an intermediate NBW is not optimal and we describe direct, simple, and asymptotically tight constructions, involving a 2o(n) blow-up. The constructions are variants of the subset construction, providing a unified approach for translating all common classes of automata to NCW and DCW. Beyond the theoretical importance of the results, we point to numerous applications of the new constructions. In particular, they imply a simple subset-construction based translation, when possible, of LTL to deterministic Büchi word automata.
AU - Boker, Udi
AU - Kupferman, Orna
ID - 494
IS - 4
JF - ACM Transactions on Computational Logic (TOCL)
TI - Translating to Co-Büchi made tight, unified, and useful
VL - 13
ER -
TY - CONF
AB - An automaton with advice is a finite state automaton which has access to an additional fixed infinite string called an advice tape. We refine the Myhill-Nerode theorem to characterize the languages of finite strings that are accepted by automata with advice. We do the same for tree automata with advice.
AU - Kruckman, Alex
AU - Rubin, Sasha
AU - Sheridan, John
AU - Zax, Ben
ID - 495
T2 - Proceedings GandALF 2012
TI - A Myhill Nerode theorem for automata with advice
VL - 96
ER -
TY - CONF
AB - We study the expressive power of logical interpretations on the class of scattered trees, namely those with countably many infinite branches. Scattered trees can be thought of as the tree analogue of scattered linear orders. Every scattered tree has an ordinal rank that reflects the structure of its infinite branches. We prove, roughly, that trees and orders of large rank cannot be interpreted in scattered trees of small rank. We consider a quite general notion of interpretation: each element of the interpreted structure is represented by a set of tuples of subsets of the interpreting tree. Our trees are countable, not necessarily finitely branching, and may have finitely many unary predicates as labellings. We also show how to replace injective set-interpretations in (not necessarily scattered) trees by 'finitary' set-interpretations.
AU - Rabinovich, Alexander
AU - Rubin, Sasha
ID - 496
TI - Interpretations in trees with countably many branches
ER -
TY - CONF
AB - One central issue in the formal design and analysis of reactive systems is the notion of refinement that asks whether all behaviors of the implementation is allowed by the specification. The local interpretation of behavior leads to the notion of simulation. Alternating transition systems (ATSs) provide a general model for composite reactive systems, and the simulation relation for ATSs is known as alternating simulation. The simulation relation for fair transition systems is called fair simulation. In this work our main contributions are as follows: (1) We present an improved algorithm for fair simulation with Büchi fairness constraints; our algorithm requires O(n 3·m) time as compared to the previous known O(n 6)-time algorithm, where n is the number of states and m is the number of transitions. (2) We present a game based algorithm for alternating simulation that requires O(m2)-time as compared to the previous known O((n·m)2)-time algorithm, where n is the number of states and m is the size of transition relation. (3) We present an iterative algorithm for alternating simulation that matches the time complexity of the game based algorithm, but is more space efficient than the game based algorithm. © Krishnendu Chatterjee, Siddhesh Chaubal, and Pritish Kamath.
AU - Chatterjee, Krishnendu
AU - Chaubal, Siddhesh
AU - Kamath, Pritish
ID - 497
TI - Faster algorithms for alternating refinement relations
VL - 16
ER -
TY - JOUR
AB - Understanding patterns and correlates of local adaptation in heterogeneous landscapes can provide important information in the selection of appropriate seed sources for restoration. We assessed the extent of local adaptation of fitness components in 12 population pairs of the perennial herb Rutidosis leptorrhynchoides (Asteraceae) and examined whether spatial scale (0.7-600 km), environmental distance, quantitative (QST) and neutral (FST) genetic differentiation, and size of the local and foreign populations could predict patterns of adaptive differentiation. Local adaptation varied among populations and fitness components. Including all population pairs, local adaptation was observed for seedling survival, but not for biomass, while foreign genotype advantage was observed for reproduction (number of inflorescences). Among population pairs, local adaptation increased with QST and local population size for biomass. QST was associated with environmental distance, suggesting ecological selection for phenotypic divergence. However, low FST and variation in population structure in small populations demonstrates the interaction of gene flow and drift in constraining local adaptation in R. leptorrhynchoides. Our study indicates that for species in heterogeneous landscapes, collecting seed from large populations from similar environments to candidate sites is likely to provide the most appropriate seed sources for restoration.
AU - Pickup, Melinda
AU - Field, David
AU - Rowell, David
AU - Young, Andrew
ID - 498
IS - 8
JF - Evolutionary Applications
TI - Predicting local adaptation in fragmented plant populations: Implications for restoration genetics
VL - 5
ER -
TY - JOUR
AU - Sixt, Michael K
ID - 506
IS - 3
JF - Journal of Cell Biology
TI - Cell migration: Fibroblasts find a new way to get ahead
VL - 197
ER -
TY - GEN
AB - Two-player games on graphs are central in many problems in formal verification and program analysis such as synthesis and verification of open systems. In this work we consider solving recursive game graphs (or pushdown game graphs) that can model the control flow of sequential programs with recursion. While pushdown games have been studied before with qualitative objectives, such as reachability and ω-regular objectives, in this work we study for the first time such games with the most well-studied quantitative objective, namely, mean-payoff objectives. In pushdown games two types of strategies are relevant: (1) global strategies, that depend on the entire global history; and (2) modular strategies, that have only local memory and thus do not depend on the context of invocation, but only on the history of the current invocation of the module. Our main results are as follows: (1) One-player pushdown games with mean-payoff objectives under global strategies are decidable in polynomial time. (2) Two- player pushdown games with mean-payoff objectives under global strategies are undecidable. (3) One-player pushdown games with mean-payoff objectives under modular strategies are NP- hard. (4) Two-player pushdown games with mean-payoff objectives under modular strategies can be solved in NP (i.e., both one-player and two-player pushdown games with mean-payoff objectives under modular strategies are NP-complete). We also establish the optimal strategy complexity showing that global strategies for mean-payoff objectives require infinite memory even in one-player pushdown games; and memoryless modular strategies are sufficient in two- player pushdown games. Finally we also show that all the problems have the same complexity if the stack boundedness condition is added, where along with the mean-payoff objective the player must also ensure that the stack height is bounded.
AU - Chatterjee, Krishnendu
AU - Velner, Yaron
ID - 5377
SN - 2664-1690
TI - Mean-payoff pushdown games
ER -
TY - GEN
AB - One central issue in the formal design and analysis of reactive systems is the notion of refinement that asks whether all behaviors of the implementation is allowed by the specification. The local interpretation of behavior leads to the notion of simulation. Alternating transition systems (ATSs) provide a general model for composite reactive systems, and the simulation relation for ATSs is known as alternating simulation. The simulation relation for fair transition systems is called fair simulation. In this work our main contributions are as follows: (1) We present an improved algorithm for fair simulation with Büchi fairness constraints; our algorithm requires O(n3 · m) time as compared to the previous known O(n6)-time algorithm, where n is the number of states and m is the number of transitions. (2) We present a game based algorithm for alternating simulation that requires O(m2)-time as compared to the previous known O((n · m)2)-time algorithm, where n is the number of states and m is the size of transition relation. (3) We present an iterative algorithm for alternating simulation that matches the time complexity of the game based algorithm, but is more space efficient than the game based algorithm.
AU - Chatterjee, Krishnendu
AU - Chaubal, Siddhesh
AU - Kamath, Pritish
ID - 5378
SN - 2664-1690
TI - Faster algorithms for alternating refinement relations
ER -
TY - GEN
AB - We consider the problem of inference in agraphical model with binary variables. While in theory it is arguably preferable to compute marginal probabilities, in practice researchers often use MAP inference due to the availability of efficient discrete optimization algorithms. We bridge the gap between the two approaches by introducing the Discrete Marginals technique in which approximate marginals are obtained by minimizing an objective function with unary and pair-wise terms over a discretized domain. This allows the use of techniques originally devel-oped for MAP-MRF inference and learning. We explore two ways to set up the objective function - by discretizing the Bethe free energy and by learning it from training data. Experimental results show that for certain types of graphs a learned function can out-perform the Bethe approximation. We also establish a link between the Bethe free energy and submodular functions.
AU - Korc, Filip
AU - Kolmogorov, Vladimir
AU - Lampert, Christoph
ID - 5396
SN - 2664-1690
TI - Approximating marginals using discrete energy minimization
ER -
TY - GEN
AB - This document is created as a part of the project “Repository for Research Data on IST Austria”. It summarises the actual state of research data at IST Austria, based on survey results. It supports the choice of appropriate software, which would best fit the requirements of their users, the researchers.
AU - Porsche, Jana
ID - 5398
TI - Actual state of research data @ ISTAustria
ER -
TY - CHAP
AU - Gupta, Ashutosh
ID - 5745
SN - 0302-9743
T2 - Automated Technology for Verification and Analysis
TI - Improved Single Pass Algorithms for Resolution Proof Reduction
VL - 7561
ER -
TY - JOUR
AB - Canny's edge detection algorithm is a classical and robust method for edge detection in gray-scale images. The two
significant features of this method are introduction of NMS (Non-Maximum Suppression) and double thresholding of
the gradient image. Due to poor illumination, the region boundaries in an image may become vague, creating
uncertainties in the gradient image. In this paper, we have proposed an algorithm based on the concept of type-2 fuzzy sets to handle uncertainties that automatically selects the threshold values needed to segment the gradient image using classical Canny’s edge detection algorithm. The results show that our algorithm works significantly well on different benchmark images as well as medical images (hand radiography images).
AU - Biswas, Ranita
AU - Sil, Jaya
ID - 5839
JF - Procedia Technology
SN - 2212-0173
TI - An Improved Canny Edge Detection Algorithm Based on Type-2 Fuzzy Sets
VL - 4
ER -
TY - JOUR
AB - The human Mediator complex controls RNA polymerase II (pol II) function in ways that remain incompletely understood. Activator-Mediator binding alters Mediator structure, and these activator-induced structural shifts appear to play key roles in regulating transcription. A recent cryo-electron microscopy (EM) analysis revealed that pol II adopted a stable orientation within a Mediator-pol II-TFIIF assembly in which Mediator was bound to the activation domain of viral protein 16 (VP16). Whereas TFIIF was shown to be important for orienting pol II within this assembly, the potential role of the activator was not assessed. To determine how activator binding might affect pol II orientation, we isolated human Mediator-pol II-TFIIF complexes in which Mediator was not bound to an activator. Cryo-EM analysis of this assembly, coupled with pol II crystal structure docking, revealed that pol II binds Mediator at the same general location; however, in contrast to VP16-bound Mediator, pol II does not appear to stably orient in the absence of an activator. Variability in pol II orientation might be important mechanistically, perhaps to enable sense and antisense transcription at human promoters. Because Mediator interacts extensively with pol II, these results suggest that Mediator structural shifts induced by activator binding help stably orient pol II prior to transcription initiation.
AU - Bernecky, Carrie A
AU - Taatjes, Dylan
ID - 596
IS - 5
JF - Journal of Molecular Biology
TI - Activator-mediator binding stabilizes RNA polymerase II orientation within the human mediator-RNA polymerase II-TFIIF assembly
VL - 417
ER -
TY - JOUR
AB - Tonic receptors convey stimulus duration and intensity and are implicated in homeostatic control. However, how tonic homeostatic signals are generated and how they reconfigure neural circuits and modify animal behavior is poorly understood. Here we show that Caenorhabditis elegans O2-sensing neurons are tonic receptors that continuously signal ambient [O2] to set the animal's behavioral state. Sustained signaling relied on a Ca2+ relay involving L-type voltage-gated Ca2+ channels, the ryanodine and the inositol-1,4,5-trisphosphate receptors. Tonic activity evoked continuous neuropeptide release, which helps elicit the enduring behavioral state associated with high [O2]. Sustained O2 receptor signaling was propagated to downstream neural circuits, including the hub interneuron RMG. O2 receptors evoked similar locomotory states at particular O2 concentrations, regardless of previous d[O2]/dt. However, a phasic component of the URX receptors' response to high d[O2]/dt, as well as tonic-to-phasic transformations in downstream interneurons, enabled transient reorientation movements shaped by d[O2]/dt. Our results highlight how tonic homeostatic signals can generate both transient and enduring behavioral change.
AU - Busch, Karl Emanuel
AU - Laurent, Patrick
AU - Soltesz, Zoltan
AU - Murphy, Robin Joseph
AU - Faivre, Olivier
AU - Hedwig, Berthold
AU - Thomas, Martin
AU - Smith, Heather L
AU - de Bono, Mario
ID - 6136
IS - 4
JF - Nature Neuroscience
SN - 1097-6256
TI - Tonic signaling from O2 sensors sets neural circuit activity and behavioral state
VL - 15
ER -
TY - JOUR
AB - Left-right asymmetry of human brain function has been known for a century, although much of molecular and cellular basis of brain laterality remains to be elusive. Recent studies suggest that hippocampal CA3-CA1 excitatory synapses are asymmetrically arranged, however, the functional implication of the asymmetrical circuitry has not been studied at the behavioral level. In order to address the left-right asymmetry of hippocampal function in behaving mice, we analyzed the performance of "split-brain" mice in the Barnes maze. The "split-brain" mice received ventral hippocampal commissure and corpus callosum transection in addition to deprivation of visual input from one eye. In such mice, the hippocampus in the side of visual deprivation receives sensory-driven input. Better spatial task performance was achieved by the mice which were forced to use the right hippocampus than those which were forced to use the left hippocampus. In two-choice spatial maze, forced usage of left hippocampus resulted in a comparable performance to the right counterpart, suggesting that both hippocampal hemispheres are capable of conducting spatial learning. Therefore, the results obtained from the Barnes maze suggest that the usage of the right hippocampus improves the accuracy of spatial memory. Performance of non-spatial yet hippocampus-dependent tasks (e.g. fear conditioning) was not influenced by the laterality of the hippocampus.
AU - Shinohara, Yoshiaki
AU - Hosoya, Aki
AU - Yamasaki, Nobuyuki
AU - Ahmed, Hassan
AU - Hattori, Satoko
AU - Eguchi, Megumi
AU - Yamaguchi, Shun
AU - Miyakawa, Tsuyoshi
AU - Hirase, Hajime
AU - Ryuichi Shigemoto
ID - 2687
IS - 2
JF - Hippocampus
TI - Right-hemispheric dominance of spatial memory in split-brain mice
VL - 22
ER -
TY - JOUR
AB - To gain insights into structure-function relationship of excitatory synapses, we revisit our quantitative analysis of synaptic AMPAR by highly sensitive freeze-fracture replica labeling in eight different connections. All of these connections showed linear correlation between synapse size and AMPAR number indicating a common intra-synapse-type relationship in CNS synapses. On the contrary, inter-synapse-type relationship is unexpected indicating no correlation between averages of synapse size and AMPAR number. Interestingly, connections with large average synapse size and low AMPAR density showed high variability of AMPAR number and mosaic distribution within the postsynaptic membrane. We propose an idea that these connections may quickly exhibit synaptic plasticity by modifying AMPAR density/number whereas those with high AMPAR density change their efficacy by modifying synapse size.
AU - Fukazawa, Yugo
AU - Ryuichi Shigemoto
ID - 2688
IS - 3
JF - Current Opinion in Neurobiology
TI - Intra-synapse-type and inter-synapse-type relationships between synaptic size and AMPAR expression
VL - 22
ER -
TY - JOUR
AB - R-type calcium channels (RTCCs) are well known for their role in synaptic plasticity, but little is known about their subcellular distribution across various neuronal compartments. Using subtype-specific antibodies, we characterized the regional and subcellular localization of Ca v2.3 in mice and rats at both light and electron microscopic levels. Ca v2.3 immunogold particles were found to be predominantly presynaptic in the interpeduncular nucleus, but postsynaptic in other brain regions. Serial section analysis of electron microscopic images from the hippocampal CA1 revealed a higher density of immunogold particles in the dendritic shaft plasma membrane compared with the pyramidal cell somata. However, the labeling densities were not significantly different among the apical, oblique, or basal dendrites. Immunogold particles were also observed over the plasma membrane of dendritic spines, including both synaptic and extrasynaptic sites. Individual spine heads contained <20 immunogold particles, with an average density of ~260 immunoparticles per μm 3 spine head volume, in accordance with the density of RTCCs estimated using calcium imaging (Sabatini and Svoboda, 2000). The Ca v2.3 density was variable among similar-sized spine heads and did not correlate with the density in the parent dendrite, implying that spines are individual calcium compartments operating autonomously from their parent dendrites.
AU - Parajuli, Laxmi K
AU - Nakajima, Chikako
AU - Kulik, Ákos
AU - Matsui, Ko
AU - Schneider, Toni
AU - Ryuichi Shigemoto
AU - Fukazawa, Yugo
ID - 2689
IS - 39
JF - Journal of Neuroscience
TI - Quantitative regional and ultra structural localization of the Ca v2 3 subunit of R type calcium channel in mouse brain
VL - 32
ER -
TY - GEN
AU - László Erdös
ID - 2696
T2 - ArXiv
TI - Universality for random matrices and log-gases
ER -
TY - CONF
AU - László Erdös
ID - 2700
TI - Lecture notes on quantum Brownian motion
VL - 95
ER -
TY - CONF
AB - We consider Markov decision processes (MDPs) with specifications given as Büchi (liveness) objectives. We consider the problem of computing the set of almost-sure winning vertices from where the objective can be ensured with probability 1. We study for the first time the average case complexity of the classical algorithm for computing the set of almost-sure winning vertices for MDPs with Büchi objectives. Our contributions are as follows: First, we show that for MDPs with constant out-degree the expected number of iterations is at most logarithmic and the average case running time is linear (as compared to the worst case linear number of iterations and quadratic time complexity). Second, for the average case analysis over all MDPs we show that the expected number of iterations is constant and the average case running time is linear (again as compared to the worst case linear number of iterations and quadratic time complexity). Finally we also show that given that all MDPs are equally likely, the probability that the classical algorithm requires more than constant number of iterations is exponentially small.
AU - Chatterjee, Krishnendu
AU - Joglekar, Manas
AU - Shah, Nisarg
ID - 2715
TI - Average case analysis of the classical algorithm for Markov decision processes with Büchi objectives
VL - 18
ER -
TY - JOUR
AB - Consider N × N Hermitian or symmetric random matrices H where the distribution of the (i, j) matrix element is given by a probability measure ν ij with a subexponential decay. Let σ ij 2 be the variance for the probability measure ν ij with the normalization property that Σ iσ i,j 2 = 1 for all j. Under essentially the only condition that c ≤ N σ ij 2 ≤ c -1 for some constant c > 0, we prove that, in the limit N → ∞, the eigenvalue spacing statistics of H in the bulk of the spectrum coincide with those of the Gaussian unitary or orthogonal ensemble (GUE or GOE). We also show that for band matrices with bandwidth M the local semicircle law holds to the energy scale M -1.
AU - László Erdös
AU - Yau, Horng-Tzer
AU - Yin, Jun
ID - 2767
IS - 1-2
JF - Probability Theory and Related Fields
TI - Bulk universality for generalized Wigner matrices
VL - 154
ER -
TY - JOUR
AB - We consider a two dimensional magnetic Schrödinger operator with a spatially stationary random magnetic field. We assume that the magnetic field has a positive lower bound and that it has Fourier modes on arbitrarily short scales. We prove the Wegner estimate at arbitrary energy, i. e. we show that the averaged density of states is finite throughout the whole spectrum. We also prove Anderson localization at the bottom of the spectrum.
AU - László Erdös
AU - Hasler, David G
ID - 2768
IS - 2
JF - Communications in Mathematical Physics
TI - Wegner estimate and Anderson localization for random magnetic fields
VL - 309
ER -
TY - JOUR
AB - We present a generalization of the method of the local relaxation flow to establish the universality of local spectral statistics of a broad class of large random matrices. We show that the local distribution of the eigenvalues coincides with the local statistics of the corresponding Gaussian ensemble provided the distribution of the individual matrix element is smooth and the eigenvalues {X J} N j=1 are close to their classical location {y j} N j=1 determined by the limiting density of eigenvalues. Under the scaling where the typical distance between neighboring eigenvalues is of order 1/N, the necessary apriori estimate on the location of eigenvalues requires only to know that E|x j - γ j| 2 ≤ N-1-ε on average. This information can be obtained by well established methods for various matrix ensembles. We demonstrate the method by proving local spectral universality for sample covariance matrices.
AU - László Erdös
AU - Schlein, Benjamin
AU - Yau, Horng-Tzer
AU - Yin, Jun
ID - 2769
IS - 1
JF - Annales de l'institut Henri Poincare (B) Probability and Statistics
TI - The local relaxation flow approach to universality of the local statistics for random matrices
VL - 48
ER -
TY - JOUR
AB - Consider N×N Hermitian or symmetric random matrices H with independent entries, where the distribution of the (i,j) matrix element is given by the probability measure vij with zero expectation and with variance σ ιj 2. We assume that the variances satisfy the normalization condition Σiσij2=1 for all j and that there is a positive constant c such that c≤Nσ ιj 2 ιc -1. We further assume that the probability distributions νij have a uniform subexponential decay. We prove that the Stieltjes transform of the empirical eigenvalue distribution of H is given by the Wigner semicircle law uniformly up to the edges of the spectrum with an error of order (Nη) -1 where η is the imaginary part of the spectral parameter in the Stieltjes transform. There are three corollaries to this strong local semicircle law: (1) Rigidity of eigenvalues: If γj=γj,N denotes the classical location of the j-th eigenvalue under the semicircle law ordered in increasing order, then the j-th eigenvalue λj is close to γj in the sense that for some positive constants C, c P{double-struck}(∃j:|λ j-γ j|≥(logN) CloglogN[min(j,N-j+1)] -1/3N -2/3)≤ C exp[-(logN) cloglogN] for N large enough. (2) The proof of Dyson's conjecture (Dyson, 1962 [15]) which states that the time scale of the Dyson Brownian motion to reach local equilibrium is of order N -1 up to logarithmic corrections. (3) The edge universality holds in the sense that the probability distributions of the largest (and the smallest) eigenvalues of two generalized Wigner ensembles are the same in the large N limit provided that the second moments of the two ensembles are identical.
AU - László Erdös
AU - Yau, Horng-Tzer
AU - Yin, Jun
ID - 2770
IS - 3
JF - Advances in Mathematics
TI - Rigidity of eigenvalues of generalized Wigner matrices
VL - 229
ER -
TY - JOUR
AB - We consider a magnetic Schrödinger operator in two dimensions. The magnetic field is given as the sum of a large and constant magnetic field and a random magnetic field. Moreover, we allow for an additional deterministic potential as well as a magnetic field which are both periodic. We show that the spectrum of this operator is contained in broadened bands around the Landau levels and that the edges of these bands consist of pure point spectrum with exponentially decaying eigenfunctions. The proof is based on a recent Wegner estimate obtained in Erdos and Hasler (Commun. Math. Phys., preprint, arXiv:1012.5185) and a multiscale analysis.
AU - László Erdös
AU - Hasler, David G
ID - 2771
IS - 5
JF - Journal of Statistical Physics
TI - Anderson localization at band edges for random magnetic fields
VL - 146
ER -
TY - JOUR
AB - We consider the semiclassical asymptotics of the sum of negative eigenvalues of the three-dimensional Pauli operator with an external potential and a self-generated magnetic field B. We also add the field energy β ∫ B 2 and we minimize over all magnetic fields. The parameter β effectively determines the strength of the field. We consider the weak field regime with βh 2 ≥ const > 0, where h is the semiclassical parameter. For smooth potentials we prove that the semiclassical asymptotics of the total energy is given by the non-magnetic Weyl term to leading order with an error bound that is smaller by a factor h 1+e{open}, i. e. the subleading term vanishes. However for potentials with a Coulomb singularity, the subleading term does not vanish due to the non-semiclassical effect of the singularity. Combined with a multiscale technique, this refined estimate is used in the companion paper (Erdo{double acute}s et al. in Scott correction for large molecules with a self-generated magnetic field, Preprint, 2011) to prove the second order Scott correction to the ground state energy of large atoms and molecules.
AU - László Erdös
AU - Fournais, Søren
AU - Solovej, Jan P
ID - 2772
IS - 4
JF - Annales Henri Poincare
TI - Second order semiclassics with self generated magnetic fields
VL - 13
ER -
TY - JOUR
AB - Recently we proved [3, 4, 6, 7, 9, 10, 11] that the eigenvalue correlation functions of a general class of random matrices converge, weakly with respect to the energy, to the corresponding ones of Gaussian matrices. Tao and Vu [15] gave a proof that for the special case of Hermitian Wigner matrices the convergence can be strengthened to vague convergence at any fixed energy in the bulk. In this article we show that this theorem is an immediate corollary of our earlier results. Indeed, a more general form of this theorem also follows directly from our work [2].
AU - László Erdös
AU - Yau, Horng-Tzer
ID - 2773
JF - Electronic Journal of Probability
TI - A comment on the Wigner-Dyson-Mehta bulk universality conjecture for Wigner matrices
VL - 17
ER -
TY - JOUR
AB - We consider a large neutral molecule with total nuclear charge Z in non-relativistic quantum mechanics with a self-generated classical electromagnetic field. To ensure stability, we assume that Zα 2 ≤ κ 0 for a sufficiently small κ 0, where α denotes the fine structure constant. We show that, in the simultaneous limit Z → ∞, α → 0 such that κ = Zα 2 is fixed, the ground state energy of the system is given by a two term expansion c 1Z 7/3 + c 2(κ) Z 2 + o(Z 2). The leading term is given by the non-magnetic Thomas-Fermi theory. Our result shows that the magnetic field affects only the second (so-called Scott) term in the expansion.
AU - László Erdös
AU - Fournais, Søren
AU - Solovej, Jan P
ID - 2774
IS - 3
JF - Communications in Mathematical Physics
TI - Scott correction for large atoms and molecules in a self-generated magnetic field
VL - 312
ER -
TY - JOUR
AB - The Wigner-Dyson-Gaudin-Mehta conjecture asserts that the local eigenvalue statistics of large random matrices exhibit universal behavior depending only on the symmetry class of the matrix ensemble. For invariant matrix models, the eigenvalue distributions are given by a log-gas with potential V and inverse temperature β = 1, 2, 4, corresponding to the orthogonal, unitary and symplectic ensembles. For β ∉ {1, 2, 4}, there is no natural random matrix ensemble behind this model, but the statistical physics interpretation of the log-gas is still valid for all β > 0. The universality conjecture for invariant ensembles asserts that the local eigenvalue statistics are independent of V. In this article, we review our recent solution to the universality conjecture for both invariant and non-invariant ensembles. We will also demonstrate that the local ergodicity of the Dyson Brownian motion is the intrinsic mechanism behind the universality. Furthermore, we review the solution of Dyson's conjecture on the local relaxation time of the Dyson Brownian motion. Related questions such as delocalization of eigenvectors and local version of Wigner's semicircle law will also be discussed.
AU - László Erdös
AU - Yau, Horng-Tzer
ID - 2775
IS - 3
JF - Bulletin of the American Mathematical Society
TI - Universality of local spectral statistics of random matrices
VL - 49
ER -
TY - JOUR
AB - We consider the ensemble of adjacency matrices of Erdős-Rényi random graphs, i.e. graphs on N vertices where every edge is chosen independently and with probability p ≡ p(N). We rescale the matrix so that its bulk eigenvalues are of order one. Under the assumption pN≫N2/3 , we prove the universality of eigenvalue distributions both in the bulk and at the edge of the spectrum. More precisely, we prove (1) that the eigenvalue spacing of the Erdős-Rényi graph in the bulk of the spectrum has the same distribution as that of the Gaussian orthogonal ensemble; and (2) that the second largest eigenvalue of the Erdős-Rényi graph has the same distribution as the largest eigenvalue of the Gaussian orthogonal ensemble. As an application of our method, we prove the bulk universality of generalized Wigner matrices under the assumption that the matrix entries have at least 4 + ε moments.
AU - László Erdös
AU - Knowles, Antti
AU - Yau, Horng-Tzer
AU - Yin, Jun
ID - 2776
IS - 3
JF - Communications in Mathematical Physics
TI - Spectral statistics of Erdős-Rényi graphs II: Eigenvalue spacing and the extreme eigenvalues
VL - 314
ER -
TY - JOUR
AB - We consider a large neutral molecule with total nuclear charge Z in a model with self-generated classical magnetic field and where the kinetic energy of the electrons is treated relativistically. To ensure stability, we assume that Zα < 2/π, where α denotes the fine structure constant. We are interested in the ground state energy in the simultaneous limit Z → ∞, α → 0 such that κ = Zα is fixed. The leading term in the energy asymptotics is independent of κ, it is given by the Thomas-Fermi energy of order Z7/3 and it is unchanged by including the self-generated magnetic field. We prove the first correction term to this energy, the so-called Scott correction of the form S(αZ)Z2. The current paper extends the result of Solovej et al. [Commun. Pure Appl. Math.LXIII, 39-118 (2010)] on the Scott correction for relativistic molecules to include a self-generated magnetic field. Furthermore, we show that the corresponding Scott correction function S, first identified by Solovej et al. [Commun. Pure Appl. Math.LXIII, 39-118 (2010)], is unchanged by including a magnetic field. We also prove new Lieb-Thirring inequalities for the relativistic kinetic energy with magnetic fields.
AU - László Erdös
AU - Fournais, Søren
AU - Solovej, Jan P
ID - 2777
IS - 9
JF - Journal of Mathematical Physics
TI - Relativistic Scott correction in self-generated magnetic fields
VL - 53
ER -
TY - JOUR
AB - We prove the bulk universality of the β-ensembles with non-convex regular analytic potentials for any β > 0. This removes the convexity assumption appeared in the earlier work [P. Bourgade, L. Erdös, and H.-T. Yau, Universality of general β-ensembles, preprint arXiv:0907.5605 (2011)]. The convexity condition enabled us to use the logarithmic Sobolev inequality to estimate events with small probability. The new idea is to introduce a "convexified measure" so that the local statistics are preserved under this convexification.
AU - Bourgade, Paul
AU - László Erdös
AU - Yau, Horng-Tzer
ID - 2778
IS - 9
JF - Journal of Mathematical Physics
TI - Bulk universality of general β-ensembles with non-convex potential
VL - 53
ER -