@article{1485,
abstract = {In this article the notion of metabolic turnover is revisited in the light of recent results of out-of-equilibrium thermodynamics. By means of Monte Carlo methods we perform an exact sampling of the enzymatic fluxes in a genome scale metabolic network of E. Coli in stationary growth conditions from which we infer the metabolites turnover times. However the latter are inferred from net fluxes, and we argue that this approximation is not valid for enzymes working nearby thermodynamic equilibrium. We recalculate turnover times from total fluxes by performing an energy balance analysis of the network and recurring to the fluctuation theorem. We find in many cases values one of order of magnitude lower, implying a faster picture of intermediate metabolism.},
author = {De Martino, Daniele},
journal = {Physical Biology},
number = {1},
publisher = {IOP Publishing Ltd.},
title = {{Genome-scale estimate of the metabolic turnover of E. Coli from the energy balance analysis}},
doi = {10.1088/1478-3975/13/1/016003},
volume = {13},
year = {2016},
}
@article{1486,
abstract = {We review recent results concerning the mathematical properties of the Bardeen-Cooper-Schrieffer (BCS) functional of superconductivity, which were obtained in a series of papers, partly in collaboration with R. Frank, E. Hamza, S. Naboko, and J. P. Solovej. Our discussion includes, in particular, an investigation of the critical temperature for a general class of interaction potentials, as well as a study of its dependence on external fields. We shall explain how the Ginzburg-Landau model can be derived from the BCS theory in a suitable parameter regime.},
author = {Hainzl, Christian and Seiringer, Robert},
journal = {Journal of Mathematical Physics},
number = {2},
publisher = {American Institute of Physics},
title = {{The Bardeen–Cooper–Schrieffer functional of superconductivity and its mathematical properties}},
doi = {10.1063/1.4941723},
volume = {57},
year = {2016},
}
@article{1487,
abstract = {Rhythms with time scales of multiple cycles per second permeate the mammalian brain, yet neuroscientists are not certain of their functional roles. One leading idea is that coherent oscillation between two brain regions facilitates the exchange of information between them. In rats, the hippocampus and the vibrissal sensorimotor system both are characterized by rhythmic oscillation in the theta range, 5–12 Hz. Previous work has been divided as to whether the two rhythms are independent or coherent. To resolve this question, we acquired three measures from rats—whisker motion, hippocampal local field potential (LFP), and barrel cortex unit firing—during a whisker-mediated texture discrimination task and during control conditions (not engaged in a whisker-mediated memory task). Compared to control conditions, the theta band of hippocampal LFP showed a marked increase in power as the rats approached and then palpated the texture. Phase synchronization between whisking and hippocampal LFP increased by almost 50% during approach and texture palpation. In addition, a greater proportion of barrel cortex neurons showed firing that was phase-locked to hippocampal theta while rats were engaged in the discrimination task. Consistent with a behavioral consequence of phase synchronization, the rats identified the texture more rapidly and with lower error likelihood on trials in which there was an increase in theta-whisking coherence at the moment of texture palpation. These results suggest that coherence between the whisking rhythm, barrel cortex firing, and hippocampal LFP is augmented selectively during epochs in which the rat collects sensory information and that such coherence enhances the efficiency of integration of stimulus information into memory and decision-making centers.},
author = {Grion, Natalia and Akrami, Athena and Zuo, Yangfang and Stella, Federico and Diamond, Mathew},
journal = {PLoS Biology},
number = {2},
publisher = {Public Library of Science},
title = {{Coherence between rat sensorimotor system and hippocampus is enhanced during tactile discrimination}},
doi = {10.1371/journal.pbio.1002384},
volume = {14},
year = {2016},
}
@article{1488,
abstract = {Branching morphogenesis of the epithelial ureteric bud forms the renal collecting duct system and is critical for normal nephron number, while low nephron number is implicated in hypertension and renal disease. Ureteric bud growth and branching requires GDNF signaling from the surrounding mesenchyme to cells at the ureteric bud tips, via the Ret receptor tyrosine kinase and coreceptor Gfrα1; Ret signaling up-regulates transcription factors Etv4 and Etv5, which are also critical for branching. Despite extensive knowledge of the genetic control of these events, it is not understood, at the cellular level, how renal branching morphogenesis is achieved or how Ret signaling influences epithelial cell behaviors to promote this process. Analysis of chimeric embryos previously suggested a role for Ret signaling in promoting cell rearrangements in the nephric duct, but this method was unsuited to study individual cell behaviors during ureteric bud branching. Here, we use Mosaic Analysis with Double Markers (MADM), combined with organ culture and time-lapse imaging, to trace the movements and divisions of individual ureteric bud tip cells. We first examine wild-type clones and then Ret or Etv4 mutant/wild-type clones in which the mutant and wild-type sister cells are differentially and heritably marked by green and red fluorescent proteins. We find that, in normal kidneys, most individual tip cells behave as self-renewing progenitors, some of whose progeny remain at the tips while others populate the growing UB trunks. In Ret or Etv4 MADM clones, the wild-type cells generated at a UB tip are much more likely to remain at, or move to, the new tips during branching and elongation, while their Ret−/− or Etv4−/− sister cells tend to lag behind and contribute only to the trunks. By tracking successive mitoses in a cell lineage, we find that Ret signaling has little effect on proliferation, in contrast to its effects on cell movement. Our results show that Ret/Etv4 signaling promotes directed cell movements in the ureteric bud tips, and suggest a model in which these cell movements mediate branching morphogenesis.},
author = {Riccio, Paul and Cebrián, Cristina and Zong, Hui and Hippenmeyer, Simon and Costantini, Frank},
journal = {PLoS Biology},
number = {2},
publisher = {Public Library of Science},
title = {{Ret and Etv4 promote directed movements of progenitor cells during renal branching morphogenesis}},
doi = {10.1371/journal.pbio.1002382},
volume = {14},
year = {2016},
}
@article{1489,
abstract = {We prove optimal local law, bulk universality and non-trivial decay for the off-diagonal elements of the resolvent for a class of translation invariant Gaussian random matrix ensembles with correlated entries. },
author = {Ajanki, Oskari H and Erdös, László and Krüger, Torben H},
journal = {Journal of Statistical Physics},
number = {2},
pages = {280 -- 302},
publisher = {Springer},
title = {{Local spectral statistics of Gaussian matrices with correlated entries}},
doi = {10.1007/s10955-016-1479-y},
volume = {163},
year = {2016},
}
@article{1480,
abstract = {Exponential varieties arise from exponential families in statistics. These real algebraic varieties have strong positivity and convexity properties, familiar from toric varieties and their moment maps. Among them are varieties of inverses of symmetric matrices satisfying linear constraints. This class includes Gaussian graphical models. We develop a general theory of exponential varieties. These are derived from hyperbolic polynomials and their integral representations. We compare the multidegrees and ML degrees of the gradient map for hyperbolic polynomials. },
author = {Michałek, Mateusz and Sturmfels, Bernd and Uhler, Caroline and Zwiernik, Piotr},
journal = {Proceedings of the London Mathematical Society},
number = {1},
pages = {27 -- 56},
publisher = {Oxford University Press},
title = {{Exponential varieties}},
doi = {10.1112/plms/pdv066},
volume = {112},
year = {2016},
}
@article{1478,
abstract = {We consider the Tonks-Girardeau gas subject to a random external potential. If the disorder is such that the underlying one-particle Hamiltonian displays localization (which is known to be generically the case), we show that there is exponential decay of correlations in the many-body eigenstates. Moreover, there is no Bose-Einstein condensation and no superfluidity, even at zero temperature.},
author = {Seiringer, Robert and Warzel, Simone},
journal = {New Journal of Physics},
number = {3},
publisher = {IOP Publishing Ltd.},
title = {{Decay of correlations and absence of superfluidity in the disordered Tonks-Girardeau gas}},
doi = {10.1088/1367-2630/18/3/035002},
volume = {18},
year = {2016},
}
@article{1445,
author = {Calatrava Moreno, Maria and Auzinger, Thomas and Werthner, Hannes},
journal = {Scientometrics},
number = {1},
pages = {233 -- 234},
publisher = {Springer},
title = {{Erratum to: On the uncertainty of interdisciplinarity measurements due to incomplete bibliographic data}},
doi = {10.1007/s11192-016-1902-9},
volume = {107},
year = {2016},
}
@article{1490,
abstract = {To induce adaptive immunity, dendritic cells (DCs) migrate through afferent lymphatic vessels (LVs) to draining lymph nodes (dLNs). This process occurs in several consecutive steps. Upon entry into lymphatic capillaries, DCs first actively crawl into downstream collecting vessels. From there, they are next passively and rapidly transported to the dLN by lymph flow. Here, we describe a role for the chemokine CCL21 in intralymphatic DC crawling. Performing time-lapse imaging in murine skin, we found that blockade of CCL21-but not the absence of lymph flow-completely abolished DC migration from capillaries toward collecting vessels and reduced the ability of intralymphatic DCs to emigrate from skin. Moreover, we found that in vitro low laminar flow established a CCL21 gradient along lymphatic endothelial monolayers, thereby inducing downstream-directed DC migration. These findings reveal a role for intralymphatic CCL21 in promoting DC trafficking to dLNs, through the formation of a flow-induced gradient.},
author = {Russo, Erica and Teijeira, Alvaro and Vaahtomeri, Kari and Willrodt, Ann and Bloch, Joël and Nitschké, Maximilian and Santambrogio, Laura and Kerjaschki, Dontscho and Sixt, Michael K and Halin, Cornelia},
journal = {Cell Reports},
number = {7},
pages = {1723 -- 1734},
publisher = {Cell Press},
title = {{Intralymphatic CCL21 promotes tissue egress of dendritic cells through afferent lymphatic vessels}},
doi = {10.1016/j.celrep.2016.01.048},
volume = {14},
year = {2016},
}
@article{1491,
abstract = {We study the ground state of a trapped Bose gas, starting from the full many-body Schrödinger Hamiltonian, and derive the non-linear Schrödinger energy functional in the limit of a large particle number, when the interaction potential converges slowly to a Dirac delta function. Our method is based on quantitative estimates on the discrepancy between the full many-body energy and its mean-field approximation using Hartree states. These are proved using finite dimensional localization and a quantitative version of the quantum de Finetti theorem. Our approach covers the case of attractive interactions in the regime of stability. In particular, our main new result is a derivation of the 2D attractive non-linear Schrödinger ground state.},
author = {Lewin, Mathieu and Nam, Phan and Rougerie, Nicolas},
journal = {Transactions of the American Mathematical Society},
number = {9},
pages = {6131 -- 6157},
publisher = {American Mathematical Society},
title = {{The mean-field approximation and the non-linear Schrödinger functional for trapped Bose gases}},
doi = {10.1090/tran/6537},
volume = {368},
year = {2016},
}
@article{1492,
abstract = {To sustain a lifelong ability to initiate organs, plants retain pools of undifferentiated cells with a preserved prolif eration capacity. The root pericycle represents a unique tissue with conditional meristematic activity, and its tight control determines initiation of lateral organs. Here we show that the meristematic activity of the pericycle is constrained by the interaction with the adjacent endodermis. Release of these restraints by elimination of endo dermal cells by single-cell ablation triggers the pericycle to re-enter the cell cycle. We found that endodermis removal substitutes for the phytohormone auxin-dependent initiation of the pericycle meristematic activity. However, auxin is indispensable to steer the cell division plane orientation of new organ-defining divisions. We propose a dual, spatiotemporally distinct role for auxin during lateral root initiation. In the endodermis, auxin releases constraints arising from cell-to-cell interactions that compromise the pericycle meristematic activity, whereas, in the pericycle, auxin defines the orientation of the cell division plane to initiate lateral roots.},
author = {Marhavy, Peter and Montesinos López, Juan C and Abuzeineh, Anas and Van Damme, Daniël and Vermeer, Joop and Duclercq, Jérôme and Rakusova, Hana and Marhavá, Petra and Friml, Jirí and Geldner, Niko and Benková, Eva},
journal = {Genes and Development},
number = {4},
pages = {471 -- 483},
publisher = {Cold Spring Harbor Laboratory Press},
title = {{Targeted cell elimination reveals an auxin-guided biphasic mode of lateral root initiation}},
doi = {10.1101/gad.276964.115},
volume = {30},
year = {2016},
}
@article{1493,
abstract = {We introduce a new method for deriving the time-dependent Hartree or Hartree-Fock equations as an effective mean-field dynamics from the microscopic Schrödinger equation for fermionic many-particle systems in quantum mechanics. The method is an adaption of the method used in Pickl (Lett. Math. Phys. 97 (2) 151–164 2011) for bosonic systems to fermionic systems. It is based on a Gronwall type estimate for a suitable measure of distance between the microscopic solution and an antisymmetrized product state. We use this method to treat a new mean-field limit for fermions with long-range interactions in a large volume. Some of our results hold for singular attractive or repulsive interactions. We can also treat Coulomb interaction assuming either a mild singularity cutoff or certain regularity conditions on the solutions to the Hartree(-Fock) equations. In the considered limit, the kinetic and interaction energy are of the same order, while the average force is subleading. For some interactions, we prove that the Hartree(-Fock) dynamics is a more accurate approximation than a simpler dynamics that one would expect from the subleading force. With our method we also treat the mean-field limit coupled to a semiclassical limit, which was discussed in the literature before, and we recover some of the previous results. All results hold for initial data close (but not necessarily equal) to antisymmetrized product states and we always provide explicit rates of convergence.},
author = {Petrat, Sören P and Pickl, Peter},
journal = {Mathematical Physics, Analysis and Geometry},
number = {1},
publisher = {Springer},
title = {{A new method and a new scaling for deriving fermionic mean-field dynamics}},
doi = {10.1007/s11040-016-9204-2},
volume = {19},
year = {2016},
}
@article{1494,
abstract = {Turbulence is one of the most frequently encountered non-equilibrium phenomena in nature, yet characterizing the transition that gives rise to turbulence in basic shear flows has remained an elusive task. Although, in recent studies, critical points marking the onset of sustained turbulence have been determined for several such flows, the physical nature of the transition could not be fully explained. In extensive experimental and computational studies we show for the example of Couette flow that the onset of turbulence is a second-order phase transition and falls into the directed percolation universality class. Consequently, the complex laminar–turbulent patterns distinctive for the onset of turbulence in shear flows result from short-range interactions of turbulent domains and are characterized by universal critical exponents. More generally, our study demonstrates that even high-dimensional systems far from equilibrium such as turbulence exhibit universality at onset and that here the collective dynamics obeys simple rules.},
author = {Lemoult, Grégoire M and Shi, Liang and Avila, Kerstin and Jalikop, Shreyas V and Avila, Marc and Hof, Björn},
journal = {Nature Physics},
number = {3},
pages = {254 -- 258},
publisher = {Nature Publishing Group},
title = {{Directed percolation phase transition to sustained turbulence in Couette flow}},
doi = {10.1038/nphys3675},
volume = {12},
year = {2016},
}
@article{1496,
abstract = {The two-photon 1s2 2s 2p 3P0 1s22s2 1S0 transition in berylliumlike ions is theoretically investigated within a fully relativistic framework and a second-order perturbation theory. We focus our analysis on how electron correlation, as well as the negative-energy spectrum, can affect the forbidden E1M1 decay rate. For this purpose, we include the electronic correlation via an effective local potential and within a single configuration-state model. Due to its experimental interest, evaluations of decay rates are performed for berylliumlike xenon and uranium. We find that the negative-energy contribution can be neglected at the present level of accuracy in the evaluation of the decay rate. On the other hand, if contributions of electronic correlation are not carefully taken into account, it may change the lifetime of the metastable state by up to 20%. By performing a full-relativistic jj-coupling calculation, we found a decrease of the decay rate by two orders of magnitude compared to non-relativistic LS-coupling calculations, for the selected heavy ions.},
author = {Amaro, Pedro and Fratini, Filippo and Safari, Laleh and Machado, Jorge and Guerra, Mauro and Indelicato, Paul and Santos, José},
journal = {Physical Review A - Atomic, Molecular, and Optical Physics},
number = {3},
publisher = {American Physical Society},
title = {{Relativistic evaluation of the two-photon decay of the metastable 1s22s2p3P0 state in berylliumlike ions with an effective-potential model}},
doi = {10.1103/PhysRevA.93.032502},
volume = {93},
year = {2016},
}
@article{1545,
abstract = {We provide general conditions for which bosonic quadratic Hamiltonians on Fock spaces can be diagonalized by Bogoliubov transformations. Our results cover the case when quantum systems have infinite degrees of freedom and the associated one-body kinetic and paring operators are unbounded. Our sufficient conditions are optimal in the sense that they become necessary when the relevant one-body operators commute.},
author = {Nam, Phan and Napiórkowski, Marcin M and Solovej, Jan},
journal = {Journal of Functional Analysis},
number = {11},
pages = {4340 -- 4368},
publisher = {Academic Press},
title = {{Diagonalization of bosonic quadratic Hamiltonians by Bogoliubov transformations}},
doi = {10.1016/j.jfa.2015.12.007},
volume = {270},
year = {2016},
}
@article{1552,
abstract = {Antibiotic resistance carries a fitness cost that must be overcome in order for resistance to persist over the long term. Compensatory mutations that recover the functional defects associated with resistance mutations have been argued to play a key role in overcoming the cost of resistance, but compensatory mutations are expected to be rare relative to generally beneficial mutations that increase fitness, irrespective of antibiotic resistance. Given this asymmetry, population genetics theory predicts that populations should adapt by compensatory mutations when the cost of resistance is large, whereas generally beneficial mutations should drive adaptation when the cost of resistance is small. We tested this prediction by determining the genomic mechanisms underpinning adaptation to antibiotic-free conditions in populations of the pathogenic bacterium Pseudomonas aeruginosa that carry costly antibiotic resistance mutations. Whole-genome sequencing revealed that populations founded by high-cost rifampicin-resistant mutants adapted via compensatory mutations in three genes of the RNA polymerase core enzyme, whereas populations founded by low-cost mutants adapted by generally beneficial mutations, predominantly in the quorum-sensing transcriptional regulator gene lasR. Even though the importance of compensatory evolution in maintaining resistance has been widely recognized, our study shows that the roles of general adaptation in maintaining resistance should not be underestimated and highlights the need to understand how selection at other sites in the genome influences the dynamics of resistance alleles in clinical settings.},
author = {Qi, Qin and Toll Riera, Macarena and Heilbron, Karl and Preston, Gail and Maclean, R Craig},
journal = {Proceedings of the Royal Society of London Series B Biological Sciences},
number = {1822},
publisher = {Royal Society, The},
title = {{The genomic basis of adaptation to the fitness cost of rifampicin resistance in Pseudomonas aeruginosa}},
doi = {10.1098/rspb.2015.2452},
volume = {283},
year = {2016},
}
@article{1408,
abstract = {The concept of well group in a special but important case captures homological properties of the zero set of a continuous map (Formula presented.) on a compact space K that are invariant with respect to perturbations of f. The perturbations are arbitrary continuous maps within (Formula presented.) distance r from f for a given (Formula presented.). The main drawback of the approach is that the computability of well groups was shown only when (Formula presented.) or (Formula presented.). Our contribution to the theory of well groups is twofold: on the one hand we improve on the computability issue, but on the other hand we present a range of examples where the well groups are incomplete invariants, that is, fail to capture certain important robust properties of the zero set. For the first part, we identify a computable subgroup of the well group that is obtained by cap product with the pullback of the orientation of (Formula presented.) by f. In other words, well groups can be algorithmically approximated from below. When f is smooth and (Formula presented.), our approximation of the (Formula presented.)th well group is exact. For the second part, we find examples of maps (Formula presented.) with all well groups isomorphic but whose perturbations have different zero sets. We discuss on a possible replacement of the well groups of vector valued maps by an invariant of a better descriptive power and computability status.},
author = {Franek, Peter and Krcál, Marek},
journal = {Discrete & Computational Geometry},
number = {1},
pages = {126 -- 164},
publisher = {Springer},
title = {{On computability and triviality of well groups}},
doi = {10.1007/s00454-016-9794-2},
volume = {56},
year = {2016},
}
@article{1518,
abstract = {The inference of demographic history from genome data is hindered by a lack of efficient computational approaches. In particular, it has proved difficult to exploit the information contained in the distribution of genealogies across the genome. We have previously shown that the generating function (GF) of genealogies can be used to analytically compute likelihoods of demographic models from configurations of mutations in short sequence blocks (Lohse et al. 2011). Although the GF has a simple, recursive form, the size of such likelihood calculations explodes quickly with the number of individuals and applications of this framework have so far been mainly limited to small samples (pairs and triplets) for which the GF can be written by hand. Here we investigate several strategies for exploiting the inherent symmetries of the coalescent. In particular, we show that the GF of genealogies can be decomposed into a set of equivalence classes that allows likelihood calculations from nontrivial samples. Using this strategy, we automated blockwise likelihood calculations for a general set of demographic scenarios in Mathematica. These histories may involve population size changes, continuous migration, discrete divergence, and admixture between multiple populations. To give a concrete example, we calculate the likelihood for a model of isolation with migration (IM), assuming two diploid samples without phase and outgroup information. We demonstrate the new inference scheme with an analysis of two individual butterfly genomes from the sister species Heliconius melpomene rosina and H. cydno.},
author = {Lohse, Konrad and Chmelik, Martin and Martin, Simon and Barton, Nicholas H},
journal = {Genetics},
number = {2},
pages = {775 -- 786},
publisher = {Genetics Society of America},
title = {{Efficient strategies for calculating blockwise likelihoods under the coalescent}},
doi = {10.1534/genetics.115.183814},
volume = {202},
year = {2016},
}
@article{1521,
abstract = {Complex I (NADH:ubiquinone oxidoreductase) plays a central role in cellular energy production, coupling electron transfer between NADH and quinone to proton translocation. It is the largest protein assembly of respiratory chains and one of the most elaborate redox membrane proteins known. Bacterial enzyme is about half the size of mitochondrial and thus provides its important "minimal" model. Dysfunction of mitochondrial complex I is implicated in many human neurodegenerative diseases. The L-shaped complex consists of a hydrophilic arm, where electron transfer occurs, and a membrane arm, where proton translocation takes place. We have solved the crystal structures of the hydrophilic domain of complex I from Thermus thermophilus, the membrane domain from Escherichia coli and recently of the intact, entire complex I from T. thermophilus (536. kDa, 16 subunits, 9 iron-sulphur clusters, 64 transmembrane helices). The 95. Å long electron transfer pathway through the enzyme proceeds from the primary electron acceptor flavin mononucleotide through seven conserved Fe-S clusters to the unusual elongated quinone-binding site at the interface with the membrane domain. Four putative proton translocation channels are found in the membrane domain, all linked by the central flexible axis containing charged residues. The redox energy of electron transfer is coupled to proton translocation by the as yet undefined mechanism proposed to involve long-range conformational changes. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.},
author = {Berrisford, John and Baradaran, Rozbeh and Sazanov, Leonid A},
journal = {Biochimica et Biophysica Acta - Bioenergetics},
number = {7},
pages = {892 -- 901},
publisher = {Elsevier},
title = {{Structure of bacterial respiratory complex I}},
doi = {10.1016/j.bbabio.2016.01.012},
volume = {1857},
year = {2016},
}
@article{1522,
abstract = {We classify smooth Brunnian (i.e., unknotted on both components) embeddings (S2 × S1) ⊔ S3 → ℝ6. Any Brunnian embedding (S2 × S1) ⊔ S3 → ℝ6 is isotopic to an explicitly constructed embedding fk,m,n for some integers k, m, n such that m ≡ n (mod 2). Two embeddings fk,m,n and fk′ ,m′,n′ are isotopic if and only if k = k′, m ≡ m′ (mod 2k) and n ≡ n′ (mod 2k). We use Haefliger’s classification of embeddings S3 ⊔ S3 → ℝ6 in our proof. The relation between the embeddings (S2 × S1) ⊔ S3 → ℝ6 and S3 ⊔ S3 → ℝ6 is not trivial, however. For example, we show that there exist embeddings f: (S2 ×S1) ⊔ S3 → ℝ6 and g, g′ : S3 ⊔ S3 → ℝ6 such that the componentwise embedded connected sum f # g is isotopic to f # g′ but g is not isotopic to g′.},
author = {Avvakumov, Serhii},
journal = {Moscow Mathematical Journal},
number = {1},
pages = {1 -- 25},
publisher = {Independent University of Moscow},
title = {{The classification of certain linked 3-manifolds in 6-space}},
volume = {16},
year = {2016},
}
@article{1523,
abstract = {For random graphs, the containment problem considers the probability that a binomial random graph G(n, p) contains a given graph as a substructure. When asking for the graph as a topological minor, i.e., for a copy of a subdivision of the given graph, it is well known that the (sharp) threshold is at p = 1/n. We consider a natural analogue of this question for higher-dimensional random complexes Xk(n, p), first studied by Cohen, Costa, Farber and Kappeler for k = 2. Improving previous results, we show that p = Θ(1/ √n) is the (coarse) threshold for containing a subdivision of any fixed complete 2-complex. For higher dimensions k > 2, we get that p = O(n−1/k) is an upper bound for the threshold probability of containing a subdivision of a fixed k-dimensional complex.},
author = {Gundert, Anna and Wagner, Uli},
journal = {Proceedings of the American Mathematical Society},
number = {4},
pages = {1815 -- 1828},
publisher = {American Mathematical Society},
title = {{On topological minors in random simplicial complexes}},
doi = {10.1090/proc/12824},
volume = {144},
year = {2016},
}
@inproceedings{1524,
abstract = {When designing genetic circuits, the typical primitives used in major existing modelling formalisms are gene interaction graphs, where edges between genes denote either an activation or inhibition relation. However, when designing experiments, it is important to be precise about the low-level mechanistic details as to how each such relation is implemented. The rule-based modelling language Kappa allows to unambiguously specify mechanistic details such as DNA binding sites, dimerisation of transcription factors, or co-operative interactions. Such a detailed description comes with complexity and computationally costly executions. We propose a general method for automatically transforming a rule-based program, by eliminating intermediate species and adjusting the rate constants accordingly. To the best of our knowledge, we show the first automated reduction of rule-based models based on equilibrium approximations.
Our algorithm is an adaptation of an existing algorithm, which was designed for reducing reaction-based programs; our version of the algorithm scans the rule-based Kappa model in search for those interaction patterns known to be amenable to equilibrium approximations (e.g. Michaelis-Menten scheme). Additional checks are then performed in order to verify if the reduction is meaningful in the context of the full model. The reduced model is efficiently obtained by static inspection over the rule-set. The tool is tested on a detailed rule-based model of a λ-phage switch, which lists 92 rules and 13 agents. The reduced model has 11 rules and 5 agents, and provides a dramatic reduction in simulation time of several orders of magnitude.},
author = {Beica, Andreea and Guet, Calin C and Petrov, Tatjana},
location = {Madrid, Spain},
pages = {173 -- 191},
publisher = {Springer},
title = {{Efficient reduction of kappa models by static inspection of the rule-set}},
doi = {10.1007/978-3-319-26916-0_10},
volume = {9271},
year = {2016},
}
@inproceedings{1526,
abstract = {We present the first study of robustness of systems that are both timed as well as reactive (I/O). We study the behavior of such timed I/O systems in the presence of uncertain inputs and formalize their robustness using the analytic notion of Lipschitz continuity: a timed I/O system is K-(Lipschitz) robust if the perturbation in its output is at most K times the perturbation in its input. We quantify input and output perturbation using similarity functions over timed words such as the timed version of the Manhattan distance and the Skorokhod distance. We consider two models of timed I/O systems — timed transducers and asynchronous sequential circuits. We show that K-robustness of timed transducers can be decided in polynomial space under certain conditions. For asynchronous sequential circuits, we reduce K-robustness w.r.t. timed Manhattan distances to K-robustness of discrete letter-to-letter transducers and show PSpace-completeness of the problem.},
author = {Henzinger, Thomas A and Otop, Jan and Samanta, Roopsha},
location = {St. Petersburg, FL, USA},
pages = {250 -- 267},
publisher = {Springer},
title = {{Lipschitz robustness of timed I/O systems}},
doi = {10.1007/978-3-662-49122-5_12},
volume = {9583},
year = {2016},
}
@article{1289,
abstract = {Aiming at the automatic diagnosis of tumors using narrow band imaging (NBI) magnifying endoscopic (ME) images of the stomach, we combine methods from image processing, topology, geometry, and machine learning to classify patterns into three classes: oval, tubular and irregular. Training the algorithm on a small number of images of each type, we achieve a high rate of correct classifications. The analysis of the learning algorithm reveals that a handful of geometric and topological features are responsible for the overwhelming majority of decisions.},
author = {Dunaeva, Olga and Edelsbrunner, Herbert and Lukyanov, Anton and Machin, Michael and Malkova, Daria and Kuvaev, Roman and Kashin, Sergey},
journal = {Pattern Recognition Letters},
number = {1},
pages = {13 -- 22},
publisher = {Elsevier},
title = {{The classification of endoscopy images with persistent homology}},
doi = {10.1016/j.patrec.2015.12.012},
volume = {83},
year = {2016},
}
@article{1592,
abstract = {A modular approach to constructing cryptographic protocols leads to simple designs but often inefficient instantiations. On the other hand, ad hoc constructions may yield efficient protocols at the cost of losing conceptual simplicity. We suggest a new design paradigm, structure-preserving cryptography, that provides a way to construct modular protocols with reasonable efficiency while retaining conceptual simplicity. A cryptographic scheme over a bilinear group is called structure-preserving if its public inputs and outputs consist of elements from the bilinear groups and their consistency can be verified by evaluating pairing-product equations. As structure-preserving schemes smoothly interoperate with each other, they are useful as building blocks in modular design of cryptographic applications. This paper introduces structure-preserving commitment and signature schemes over bilinear groups with several desirable properties. The commitment schemes include homomorphic, trapdoor and length-reducing commitments to group elements, and the structure-preserving signature schemes are the first ones that yield constant-size signatures on multiple group elements. A structure-preserving signature scheme is called automorphic if the public keys lie in the message space, which cannot be achieved by compressing inputs via a cryptographic hash function, as this would destroy the mathematical structure we are trying to preserve. Automorphic signatures can be used for building certification chains underlying privacy-preserving protocols. Among a vast number of applications of structure-preserving protocols, we present an efficient round-optimal blind-signature scheme and a group signature scheme with an efficient and concurrently secure protocol for enrolling new members.},
author = {Abe, Masayuki and Fuchsbauer, Georg and Groth, Jens and Haralambiev, Kristiyan and Ohkubo, Miyako},
journal = {Journal of Cryptology},
number = {2},
pages = {363 -- 421},
publisher = {Springer},
title = {{Structure preserving signatures and commitments to group elements}},
doi = {10.1007/s00145-014-9196-7},
volume = {29},
year = {2016},
}
@article{1599,
abstract = {The addition of polysialic acid to N- and/or O-linked glycans, referred to as polysialylation, is a rare posttranslational modification that is mainly known to control the developmental plasticity of the nervous system. Here we show that CCR7, the central chemokine receptor controlling immune cell trafficking to secondary lymphatic organs, carries polysialic acid. This modification is essential for the recognition of the CCR7 ligand CCL21. As a consequence, dendritic cell trafficking is abrogated in polysialyltransferase-deficient mice, manifesting as disturbed lymph node homeostasis and unresponsiveness to inflammatory stimuli. Structure-function analysis of chemokine-receptor interactions reveals that CCL21 adopts an autoinhibited conformation, which is released upon interaction with polysialic acid. Thus, we describe a glycosylation-mediated immune cell trafficking disorder and its mechanistic basis.
},
author = {Kiermaier, Eva and Moussion, Christine and Veldkamp, Christopher and Gerardy Schahn, Rita and De Vries, Ingrid and Williams, Larry and Chaffee, Gary and Phillips, Andrew and Freiberger, Friedrich and Imre, Richard and Taleski, Deni and Payne, Richard and Braun, Asolina and Förster, Reinhold and Mechtler, Karl and Mühlenhoff, Martina and Volkman, Brian and Sixt, Michael K},
journal = {Science},
number = {6269},
pages = {186 -- 190},
publisher = {American Association for the Advancement of Science},
title = {{Polysialylation controls dendritic cell trafficking by regulating chemokine recognition}},
doi = {10.1126/science.aad0512},
volume = {351},
year = {2016},
}
@article{1597,
abstract = {Chemokines are the main guidance cues directing leukocyte migration. Opposed to early assumptions, chemokines do not necessarily act as soluble cues but are often immobilized within tissues, e.g., dendritic cell migration toward lymphatic vessels is guided by a haptotactic gradient of the chemokine CCL21. Controlled assay systems to quantitatively study haptotaxis in vitro are still missing. In this chapter, we describe an in vitro haptotaxis assay optimized for the unique properties of dendritic cells. The chemokine CCL21 is immobilized in a bioactive state, using laser-assisted protein adsorption by photobleaching. The cells follow this immobilized CCL21 gradient in a haptotaxis chamber, which provides three dimensionally confined migration conditions.},
author = {Schwarz, Jan and Sixt, Michael K},
journal = {Methods in Enzymology},
pages = {567 -- 581},
publisher = {Elsevier},
title = {{Quantitative analysis of dendritic cell haptotaxis}},
doi = {10.1016/bs.mie.2015.11.004},
volume = {570},
year = {2016},
}
@inproceedings{1164,
abstract = {A drawing of a graph G is radial if the vertices of G are placed on concentric circles C1, … , Ck with common center c, and edges are drawn radially: every edge intersects every circle centered at c at most once. G is radial planar if it has a radial embedding, that is, a crossing-free radial drawing. If the vertices of G are ordered or partitioned into ordered levels (as they are for leveled graphs), we require that the assignment of vertices to circles corresponds to the given ordering or leveling. A pair of edges e and f in a graph is independent if e and f do not share a vertex. We show that a graph G is radial planar if G has a radial drawing in which every two independent edges cross an even number of times; the radial embedding has the same leveling as the radial drawing. In other words, we establish the strong Hanani-Tutte theorem for radial planarity. This characterization yields a very simple algorithm for radial planarity testing.},
author = {Fulek, Radoslav and Pelsmajer, Michael and Schaefer, Marcus},
location = {Athens, Greece},
pages = {468 -- 481},
publisher = {Springer},
title = {{Hanani-Tutte for radial planarity II}},
doi = {10.1007/978-3-319-50106-2_36},
volume = {9801},
year = {2016},
}
@article{1608,
abstract = {We show that the Anderson model has a transition from localization to delocalization at exactly 2 dimensional growth rate on antitrees with normalized edge weights which are certain discrete graphs. The kinetic part has a one-dimensional structure allowing a description through transfer matrices which involve some Schur complement. For such operators we introduce the notion of having one propagating channel and extend theorems from the theory of one-dimensional Jacobi operators that relate the behavior of transfer matrices with the spectrum. These theorems are then applied to the considered model. In essence, in a certain energy region the kinetic part averages the random potentials along shells and the transfer matrices behave similar as for a one-dimensional operator with random potential of decaying variance. At d dimensional growth for d>2 this effective decay is strong enough to obtain absolutely continuous spectrum, whereas for some uniform d dimensional growth with d<2 one has pure point spectrum in this energy region. At exactly uniform 2 dimensional growth also some singular continuous spectrum appears, at least at small disorder. As a corollary we also obtain a change from singular spectrum (d≤2) to absolutely continuous spectrum (d≥3) for random operators of the type rΔdr+λ on ℤd, where r is an orthogonal radial projection, Δd the discrete adjacency operator (Laplacian) on ℤd and λ a random potential. },
author = {Sadel, Christian},
journal = {Annales Henri Poincare},
number = {7},
pages = {1631 -- 1675},
publisher = {Birkhäuser},
title = {{Anderson transition at 2 dimensional growth rate on antitrees and spectral theory for operators with one propagating channel}},
doi = {10.1007/s00023-015-0456-3},
volume = {17},
year = {2016},
}
@article{1620,
abstract = {We consider the Bardeen–Cooper–Schrieffer free energy functional for particles interacting via a two-body potential on a microscopic scale and in the presence of weak external fields varying on a macroscopic scale. We study the influence of the external fields on the critical temperature. We show that in the limit where the ratio between the microscopic and macroscopic scale tends to zero, the next to leading order of the critical temperature is determined by the lowest eigenvalue of the linearization of the Ginzburg–Landau equation.},
author = {Frank, Rupert and Hainzl, Christian and Seiringer, Robert and Solovej, Jan},
journal = {Communications in Mathematical Physics},
number = {1},
pages = {189 -- 216},
publisher = {Springer},
title = {{The external field dependence of the BCS critical temperature}},
doi = {10.1007/s00220-015-2526-2},
volume = {342},
year = {2016},
}
@article{1622,
abstract = {We prove analogues of the Lieb–Thirring and Hardy–Lieb–Thirring inequalities for many-body quantum systems with fractional kinetic operators and homogeneous interaction potentials, where no anti-symmetry on the wave functions is assumed. These many-body inequalities imply interesting one-body interpolation inequalities, and we show that the corresponding one- and many-body inequalities are actually equivalent in certain cases.},
author = {Lundholm, Douglas and Nam, Phan and Portmann, Fabian},
journal = {Archive for Rational Mechanics and Analysis},
number = {3},
pages = {1343 -- 1382},
publisher = {Springer},
title = {{Fractional Hardy–Lieb–Thirring and related Inequalities for interacting systems}},
doi = {10.1007/s00205-015-0923-5},
volume = {219},
year = {2016},
}
@article{1631,
abstract = {Ancestral processes are fundamental to modern population genetics and spatial structure has been the subject of intense interest for many years. Despite this interest, almost nothing is known about the distribution of the locations of pedigree or genetic ancestors. Using both spatially continuous and stepping-stone models, we show that the distribution of pedigree ancestors approaches a travelling wave, for which we develop two alternative approximations. The speed and width of the wave are sensitive to the local details of the model. After a short time, genetic ancestors spread far more slowly than pedigree ancestors, ultimately diffusing out with radius ## rather than spreading at constant speed. In contrast to the wave of pedigree ancestors, the spread of genetic ancestry is insensitive to the local details of the models.},
author = {Kelleher, Jerome and Etheridge, Alison and Véber, Amandine and Barton, Nicholas H},
journal = {Theoretical Population Biology},
pages = {1 -- 12},
publisher = {Academic Press},
title = {{Spread of pedigree versus genetic ancestry in spatially distributed populations}},
doi = {10.1016/j.tpb.2015.10.008},
volume = {108},
year = {2016},
}
@article{1612,
abstract = {We prove that whenever A is a 3-conservative relational structure with only binary and unary relations,then the algebra of polymorphisms of A either has no Taylor operation (i.e.,CSP(A)is NP-complete),or it generates an SD(∧) variety (i.e.,CSP(A)has bounded width).},
author = {Kazda, Alexandr},
journal = {Algebra Universalis},
number = {1},
pages = {75 -- 84},
publisher = {Springer},
title = {{CSP for binary conservative relational structures}},
doi = {10.1007/s00012-015-0358-8},
volume = {75},
year = {2016},
}
@article{1613,
abstract = {In the last decade, induced pluripotent stem (iPS) cells have revolutionized the utility of human in vitro models of neurological disease. The iPS-derived and differentiated cells allow researchers to study the impact of a distinct cell type in health and disease as well as performing therapeutic drug screens on a human genetic background. In particular, clinical trials for Alzheimer's disease (AD) have been often failing. Two of the potential reasons are first, the species gap involved in proceeding from initial discoveries in rodent models to human studies, and second, an unsatisfying patient stratification, meaning subgrouping patients based on the disease severity due to the lack of phenotypic and genetic markers. iPS cells overcome this obstacles and will improve our understanding of disease subtypes in AD. They allow researchers conducting in depth characterization of neural cells from both familial and sporadic AD patients as well as preclinical screens on human cells.
In this review, we briefly outline the status quo of iPS cell research in neurological diseases along with the general advantages and pitfalls of these models. We summarize how genome-editing techniques such as CRISPR/Cas will allow researchers to reduce the problem of genomic variability inherent to human studies, followed by recent iPS cell studies relevant to AD. We then focus on current techniques for the differentiation of iPS cells into neural cell types that are relevant to AD research. Finally, we discuss how the generation of three-dimensional cell culture systems will be important for understanding AD phenotypes in a complex cellular milieu, and how both two- and three-dimensional iPS cell models can provide platforms for drug discovery and translational studies into the treatment of AD.},
author = {Mungenast, Alison and Siegert, Sandra and Tsai, Li},
journal = {Molecular and Cellular Neuroscience},
pages = {13 -- 31},
publisher = {Academic Press},
title = {{Modeling Alzheimer's disease with human induced pluripotent stem (iPS) cells}},
doi = {doi:10.1016/j.mcn.2015.11.010},
volume = {73},
year = {2016},
}
@article{1616,
abstract = {The hippocampus plays a key role in learning and memory. Previous studies suggested that the main types of principal neurons, dentate gyrus granule cells (GCs), CA3 pyramidal neurons, and CA1 pyramidal neurons, differ in their activity pattern, with sparse firing in GCs and more frequent firing in CA3 and CA1 pyramidal neurons. It has been assumed but never shown that such different activity may be caused by differential synaptic excitation. To test this hypothesis, we performed high-resolution whole-cell patch-clamp recordings in anesthetized rats in vivo. In contrast to previous in vitro data, both CA3 and CA1 pyramidal neurons fired action potentials spontaneously, with a frequency of ∼3–6 Hz, whereas GCs were silent. Furthermore, both CA3 and CA1 cells primarily fired in bursts. To determine the underlying mechanisms, we quantitatively assessed the frequency of spontaneous excitatory synaptic input, the passive membrane properties, and the active membrane characteristics. Surprisingly, GCs showed comparable synaptic excitation to CA3 and CA1 cells and the highest ratio of excitation versus hyperpolarizing inhibition. Thus, differential synaptic excitation is not responsible for differences in firing. Moreover, the three types of hippocampal neurons markedly differed in their passive properties. While GCs showed the most negative membrane potential, CA3 pyramidal neurons had the highest input resistance and the slowest membrane time constant. The three types of neurons also differed in the active membrane characteristics. GCs showed the highest action potential threshold, but displayed the largest gain of the input-output curves. In conclusion, our results reveal that differential firing of the three main types of hippocampal principal neurons in vivo is not primarily caused by differences in the characteristics of the synaptic input, but by the distinct properties of synaptic integration and input-output transformation.},
author = {Kowalski, Janina and Gan, Jian and Jonas, Peter M and Pernia-Andrade, Alejandro},
journal = {Hippocampus},
number = {5},
pages = {668 -- 682},
publisher = {John Wiley and Sons Inc.},
title = {{Intrinsic membrane properties determine hippocampal differential firing pattern in vivo in anesthetized rats}},
doi = {10.1002/hipo.22550},
volume = {26},
year = {2016},
}
@article{1617,
abstract = {We study the discrepancy of jittered sampling sets: such a set P⊂ [0,1]d is generated for fixed m∈ℕ by partitioning [0,1]d into md axis aligned cubes of equal measure and placing a random point inside each of the N=md cubes. We prove that, for N sufficiently large, 1/10 d/N1/2+1/2d ≤EDN∗(P)≤ √d(log N) 1/2/N1/2+1/2d, where the upper bound with an unspecified constant Cd was proven earlier by Beck. Our proof makes crucial use of the sharp Dvoretzky-Kiefer-Wolfowitz inequality and a suitably taylored Bernstein inequality; we have reasons to believe that the upper bound has the sharp scaling in N. Additional heuristics suggest that jittered sampling should be able to improve known bounds on the inverse of the star-discrepancy in the regime N≳dd. We also prove a partition principle showing that every partition of [0,1]d combined with a jittered sampling construction gives rise to a set whose expected squared L2-discrepancy is smaller than that of purely random points.},
author = {Pausinger, Florian and Steinerberger, Stefan},
journal = {Journal of Complexity},
pages = {199 -- 216},
publisher = {Academic Press},
title = {{On the discrepancy of jittered sampling}},
doi = {10.1016/j.jco.2015.11.003},
volume = {33},
year = {2016},
}
@article{1641,
abstract = {The plant hormone auxin (indole-3-acetic acid) is a major regulator of plant growth and development including embryo and root patterning, lateral organ formation and growth responses to environmental stimuli. Auxin is directionally transported from cell to cell by the action of specific auxin influx [AUXIN-RESISTANT1 (AUX1)] and efflux [PIN-FORMED (PIN)] transport regulators, whose polar, subcellular localizations are aligned with the direction of the auxin flow. Auxin itself regulates its own transport by modulation of the expression and subcellular localization of the auxin transporters. Increased auxin levels promote the transcription of PIN2 and AUX1 genes as well as stabilize PIN proteins at the plasma membrane, whereas prolonged auxin exposure increases the turnover of PIN proteins and their degradation in the vacuole. In this study, we applied a forward genetic approach, to identify molecular components playing a role in the auxin-mediated degradation. We generated EMS-mutagenized Arabidopsis PIN2::PIN2:GFP, AUX1::AUX1:YFP eir1aux1 populations and designed a screen for mutants with persistently strong fluorescent signals of the tagged PIN2 and AUX1 after prolonged treatment with the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D). This approach yielded novel auxin degradation mutants defective in trafficking and degradation of PIN2 and AUX1 proteins and established a role for auxin-mediated degradation in plant development.},
author = {Zemová, Radka and Zwiewka, Marta and Bielach, Agnieszka and Robert, Hélène and Friml, Jirí},
journal = {Journal of Plant Growth Regulation},
number = {2},
pages = {465 -- 476},
publisher = {Springer},
title = {{A forward genetic screen for new regulators of auxin mediated degradation of auxin transport proteins in Arabidopsis thaliana}},
doi = {10.1007/s00344-015-9553-2},
volume = {35},
year = {2016},
}
@inproceedings{1653,
abstract = {A somewhere statistically binding (SSB) hash, introduced by Hubáček and Wichs (ITCS ’15), can be used to hash a long string x to a short digest y = H hk (x) using a public hashing-key hk. Furthermore, there is a way to set up the hash key hk to make it statistically binding on some arbitrary hidden position i, meaning that: (1) the digest y completely determines the i’th bit (or symbol) of x so that all pre-images of y have the same value in the i’th position, (2) it is computationally infeasible to distinguish the position i on which hk is statistically binding from any other position i’. Lastly, the hash should have a local opening property analogous to Merkle-Tree hashing, meaning that given x and y = H hk (x) it should be possible to create a short proof π that certifies the value of the i’th bit (or symbol) of x without having to provide the entire input x. A similar primitive called a positional accumulator, introduced by Koppula, Lewko and Waters (STOC ’15) further supports dynamic updates of the hashed value. These tools, which are interesting in their own right, also serve as one of the main technical components in several recent works building advanced applications from indistinguishability obfuscation (iO).
The prior constructions of SSB hashing and positional accumulators required fully homomorphic encryption (FHE) and iO respectively. In this work, we give new constructions of these tools based on well studied number-theoretic assumptions such as DDH, Phi-Hiding and DCR, as well as a general construction from lossy/injective functions.},
author = {Okamoto, Tatsuaki and Pietrzak, Krzysztof Z and Waters, Brent and Wichs, Daniel},
location = {Auckland, New Zealand},
pages = {121 -- 145},
publisher = {Springer},
title = {{New realizations of somewhere statistically binding hashing and positional accumulators}},
doi = {10.1007/978-3-662-48797-6_6},
volume = {9452},
year = {2016},
}
@inproceedings{1225,
abstract = {At Crypto 2015 Fuchsbauer, Hanser and Slamanig (FHS) presented the first standard-model construction of efficient roundoptimal blind signatures that does not require complexity leveraging. It is conceptually simple and builds on the primitive of structure-preserving signatures on equivalence classes (SPS-EQ). FHS prove the unforgeability of their scheme assuming EUF-CMA security of the SPS-EQ scheme and hardness of a version of the DH inversion problem. Blindness under adversarially chosen keys is proven under an interactive variant of the DDH assumption. We propose a variant of their scheme whose blindness can be proven under a non-interactive assumption, namely a variant of the bilinear DDH assumption. We moreover prove its unforgeability assuming only unforgeability of the underlying SPS-EQ but no additional assumptions as needed for the FHS scheme.},
author = {Fuchsbauer, Georg and Hanser, Christian and Kamath Hosdurg, Chethan and Slamanig, Daniel},
location = {Amalfi, Italy},
pages = {391 -- 408},
publisher = {Springer},
title = {{Practical round-optimal blind signatures in the standard model from weaker assumptions}},
doi = {10.1007/978-3-319-44618-9_21},
volume = {9841},
year = {2016},
}
@article{1148,
abstract = {Continuous-time Markov chain (CTMC) models have become a central tool for understanding the dynamics of complex reaction networks and the importance of stochasticity in the underlying biochemical processes. When such models are employed to answer questions in applications, in order to ensure that the model provides a sufficiently accurate representation of the real system, it is of vital importance that the model parameters are inferred from real measured data. This, however, is often a formidable task and all of the existing methods fail in one case or the other, usually because the underlying CTMC model is high-dimensional and computationally difficult to analyze. The parameter inference methods that tend to scale best in the dimension of the CTMC are based on so-called moment closure approximations. However, there exists a large number of different moment closure approximations and it is typically hard to say a priori which of the approximations is the most suitable for the inference procedure. Here, we propose a moment-based parameter inference method that automatically chooses the most appropriate moment closure method. Accordingly, contrary to existing methods, the user is not required to be experienced in moment closure techniques. In addition to that, our method adaptively changes the approximation during the parameter inference to ensure that always the best approximation is used, even in cases where different approximations are best in different regions of the parameter space. © 2016 Elsevier Ireland Ltd},
author = {Schilling, Christian and Bogomolov, Sergiy and Henzinger, Thomas A and Podelski, Andreas and Ruess, Jakob},
journal = {Biosystems},
pages = {15 -- 25},
publisher = {Elsevier},
title = {{Adaptive moment closure for parameter inference of biochemical reaction networks}},
doi = {10.1016/j.biosystems.2016.07.005},
volume = {149},
year = {2016},
}
@article{1662,
abstract = {We introduce a modification of the classic notion of intrinsic volume using persistence moments of height functions. Evaluating the modified first intrinsic volume on digital approximations of a compact body with smoothly embedded boundary in Rn, we prove convergence to the first intrinsic volume of the body as the resolution of the approximation improves. We have weaker results for the other modified intrinsic volumes, proving they converge to the corresponding intrinsic volumes of the n-dimensional unit ball.},
author = {Edelsbrunner, Herbert and Pausinger, Florian},
journal = {Advances in Mathematics},
pages = {674 -- 703},
publisher = {Academic Press},
title = {{Approximation and convergence of the intrinsic volume}},
doi = {10.1016/j.aim.2015.10.004},
volume = {287},
year = {2016},
}
@article{1705,
abstract = {Hybrid systems represent an important and powerful formalism for modeling real-world applications such as embedded systems. A verification tool like SpaceEx is based on the exploration of a symbolic search space (the region space). As a verification tool, it is typically optimized towards proving the absence of errors. In some settings, e.g., when the verification tool is employed in a feedback-directed design cycle, one would like to have the option to call a version that is optimized towards finding an error trajectory in the region space. A recent approach in this direction is based on guided search. Guided search relies on a cost function that indicates which states are promising to be explored, and preferably explores more promising states first. In this paper, we propose an abstraction-based cost function based on coarse-grained space abstractions for guiding the reachability analysis. For this purpose, a suitable abstraction technique that exploits the flexible granularity of modern reachability analysis algorithms is introduced. The new cost function is an effective extension of pattern database approaches that have been successfully applied in other areas. The approach has been implemented in the SpaceEx model checker. The evaluation shows its practical potential.},
author = {Bogomolov, Sergiy and Donzé, Alexandre and Frehse, Goran and Grosu, Radu and Johnson, Taylor and Ladan, Hamed and Podelski, Andreas and Wehrle, Martin},
journal = {International Journal on Software Tools for Technology Transfer},
number = {4},
pages = {449 -- 467},
publisher = {Springer},
title = {{Guided search for hybrid systems based on coarse-grained space abstractions}},
doi = {10.1007/s10009-015-0393-y},
volume = {18},
year = {2016},
}
@inproceedings{1707,
abstract = {Volunteer supporters play an important role in modern crisis and disaster management. In the times of mobile Internet devices, help from thousands of volunteers can be requested within a short time span, thus relieving professional helpers from minor chores or geographically spread-out tasks. However, the simultaneous availability of many volunteers also poses new problems. In particular, the volunteer efforts must be well coordinated, or otherwise situations might emerge in which too many idle volunteers at one location become more of a burden than a relief to the professionals.
In this work, we study the task of optimally assigning volunteers to selected locations, e.g. in order to perform regular measurements, to report on damage, or to distribute information or resources to the population in a crisis situation. We formulate the assignment tasks as an optimization problem and propose an effective and efficient solution procedure. Experiments on real data of the Team Österreich, consisting of over 36,000 Austrian volunteers, show the effectiveness and efficiency of our approach.},
author = {Pielorz, Jasmin and Lampert, Christoph},
location = {Rennes, France},
publisher = {IEEE},
title = {{Optimal geospatial allocation of volunteers for crisis management}},
doi = {10.1109/ICT-DM.2015.7402041},
year = {2016},
}
@article{173,
abstract = {We calculate admissible values of r such that a square-free polynomial with integer coefficients, no fixed prime divisor and irreducible factors of degree at most 3 takes infinitely many values that are a product of at most r distinct primes.},
author = {Browning, Timothy D and Booker, Andrew},
journal = {Discrete Analysis},
pages = {1 -- 18},
title = {{Square-free values of reducible polynomials}},
doi = {10.19086/da.732},
volume = {8},
year = {2016},
}
@article{1833,
abstract = {Relational models for contingency tables are generalizations of log-linear models, allowing effects associated with arbitrary subsets of cells in the table, and not necessarily containing the overall effect, that is, a common parameter in every cell. Similarly to log-linear models, relational models can be extended to non-negative distributions, but the extension requires more complex methods. An extended relational model is defined as an algebraic variety, and it turns out to be the closure of the original model with respect to the Bregman divergence. In the extended relational model, the MLE of the cell parameters always exists and is unique, but some of its properties may be different from those of the MLE under log-linear models. The MLE can be computed using a generalized iterative scaling procedure based on Bregman projections. },
author = {Klimova, Anna and Rudas, Tamás},
journal = {Journal of Multivariate Analysis},
pages = {440 -- 452},
publisher = {Elsevier},
title = {{On the closure of relational models}},
doi = {10.1016/j.jmva.2015.10.005},
volume = {143},
year = {2016},
}
@article{1881,
abstract = {We consider random matrices of the form H=W+λV, λ∈ℝ+, where W is a real symmetric or complex Hermitian Wigner matrix of size N and V is a real bounded diagonal random matrix of size N with i.i.d.\ entries that are independent of W. We assume subexponential decay for the matrix entries of W and we choose λ∼1, so that the eigenvalues of W and λV are typically of the same order. Further, we assume that the density of the entries of V is supported on a single interval and is convex near the edges of its support. In this paper we prove that there is λ+∈ℝ+ such that the largest eigenvalues of H are in the limit of large N determined by the order statistics of V for λ>λ+. In particular, the largest eigenvalue of H has a Weibull distribution in the limit N→∞ if λ>λ+. Moreover, for N sufficiently large, we show that the eigenvectors associated to the largest eigenvalues are partially localized for λ>λ+, while they are completely delocalized for λ<λ+. Similar results hold for the lowest eigenvalues. },
author = {Lee, Jioon and Schnelli, Kevin},
journal = {Probability Theory and Related Fields},
number = {1-2},
pages = {165 -- 241},
publisher = {Springer},
title = {{Extremal eigenvalues and eigenvectors of deformed Wigner matrices}},
doi = {10.1007/s00440-014-0610-8},
volume = {164},
year = {2016},
}
@article{1243,
abstract = {Restriction-modification (RM) systems represent a minimal and ubiquitous biological system of self/non-self discrimination in prokaryotes [1], which protects hosts from exogenous DNA [2]. The mechanism is based on the balance between methyltransferase (M) and cognate restriction endonuclease (R). M tags endogenous DNA as self by methylating short specific DNA sequences called restriction sites, whereas R recognizes unmethylated restriction sites as non-self and introduces a double-stranded DNA break [3]. Restriction sites are significantly underrepresented in prokaryotic genomes [4-7], suggesting that the discrimination mechanism is imperfect and occasionally leads to autoimmunity due to self-DNA cleavage (self-restriction) [8]. Furthermore, RM systems can promote DNA recombination [9] and contribute to genetic variation in microbial populations, thus facilitating adaptive evolution [10]. However, cleavage of self-DNA by RM systems as elements shaping prokaryotic genomes has not been directly detected, and its cause, frequency, and outcome are unknown. We quantify self-restriction caused by two RM systems of Escherichia coli and find that, in agreement with levels of restriction site avoidance, EcoRI, but not EcoRV, cleaves self-DNA at a measurable rate. Self-restriction is a stochastic process, which temporarily induces the SOS response, and is followed by DNA repair, maintaining cell viability. We find that RM systems with higher restriction efficiency against bacteriophage infections exhibit a higher rate of self-restriction, and that this rate can be further increased by stochastic imbalance between R and M. Our results identify molecular noise in RM systems as a factor shaping prokaryotic genomes.},
author = {Pleska, Maros and Qian, Long and Okura, Reiko and Bergmiller, Tobias and Wakamoto, Yuichi and Kussell, Edo and Guet, Calin C},
journal = {Current Biology},
number = {3},
pages = {404 -- 409},
publisher = {Cell Press},
title = {{Bacterial autoimmunity due to a restriction-modification system}},
doi = {10.1016/j.cub.2015.12.041},
volume = {26},
year = {2016},
}
@phdthesis{1125,
abstract = {Natural environments are never constant but subject to spatial and temporal change on
all scales, increasingly so due to human activity. Hence, it is crucial to understand the
impact of environmental variation on evolutionary processes. In this thesis, I present
three topics that share the common theme of environmental variation, yet illustrate its
effect from different perspectives.
First, I show how a temporally fluctuating environment gives rise to second-order
selection on a modifier for stress-induced mutagenesis. Without fluctuations, when
populations are adapted to their environment, mutation rates are minimized. I argue
that a stress-induced mutator mechanism may only be maintained if the population is
repeatedly subjected to diverse environmental challenges, and I outline implications of
the presented results to antibiotic treatment strategies.
Second, I discuss my work on the evolution of dispersal. Besides reproducing
known results about the effect of heterogeneous habitats on dispersal, it identifies
spatial changes in dispersal type frequencies as a source for selection for increased
propensities to disperse. This concept contains effects of relatedness that are known
to promote dispersal, and I explain how it identifies other forces selecting for dispersal
and puts them on a common scale.
Third, I analyse genetic variances of phenotypic traits under multivariate stabilizing
selection. For the case of constant environments, I generalize known formulae of
equilibrium variances to multiple traits and discuss how the genetic variance of a focal
trait is influenced by selection on background traits. I conclude by presenting ideas and
preliminary work aiming at including environmental fluctuations in the form of moving
trait optima into the model.},
author = {Novak, Sebastian},
pages = {124},
publisher = {IST Austria},
title = {{Evolutionary proccesses in variable emvironments}},
year = {2016},
}
@phdthesis{1123,
abstract = {Motivated by topological Tverberg-type problems in topological combinatorics and by classical
results about embeddings (maps without double points), we study the question whether a finite
simplicial complex K can be mapped into Rd without triple, quadruple, or, more generally, r-fold points (image points with at least r distinct preimages), for a given multiplicity r ≤ 2. In particular, we are interested in maps f : K → Rd that have no global r -fold intersection points, i.e., no r -fold points with preimages in r pairwise disjoint simplices of K , and we seek necessary and sufficient conditions for the existence of such maps.
We present higher-multiplicity analogues of several classical results for embeddings, in particular of the completeness of the Van Kampen obstruction for embeddability of k -dimensional
complexes into R2k , k ≥ 3. Speciffically, we show that under suitable restrictions on the dimensions(viz., if dimK = (r ≥ 1)k and d = rk \ for some k ≥ 3), a well-known deleted product criterion (DPC ) is not only necessary but also sufficient for the existence of maps without global r -fold points. Our main technical tool is a higher-multiplicity version of the classical Whitney trick , by which pairs of isolated r -fold points of opposite sign can be eliminated by local modiffications of the map, assuming codimension d – dimK ≥ 3.
An important guiding idea for our work was that suffciency of the DPC, together with an old
result of Özaydin's on the existence of equivariant maps, might yield an approach to disproving the remaining open cases of the the long-standing topological Tverberg conjecture , i.e., to construct maps from the N -simplex σN to Rd without r-Tverberg points when r not a prime power and
N = (d + 1)(r – 1). Unfortunately, our proof of the sufficiency of the DPC requires codimension d – dimK ≥ 3, which is not satisfied for K = σN .
In 2015, Frick [16] found a very elegant way to overcome this \codimension 3 obstacle" and
to construct the first counterexamples to the topological Tverberg conjecture for all parameters(d; r ) with d ≥ 3r + 1 and r not a prime power, by a reduction1 to a suitable lower-dimensional skeleton, for which the codimension 3 restriction is satisfied and maps without r -Tverberg points exist by Özaydin's result and sufficiency of the DPC.
In this thesis, we present a different construction (which does not use the constraint method) that yields counterexamples for d ≥ 3r , r not a prime power. },
author = {Mabillard, Isaac},
pages = {55},
publisher = {IST Austria},
title = {{Eliminating higher-multiplicity intersections: an r-fold Whitney trick for the topological Tverberg conjecture}},
year = {2016},
}
@article{1411,
abstract = {We consider two systems (α1, …, αm) and (β1, …,βn) of simple curves drawn on a compact two-dimensional surface M with boundary. Each αi and each βj is either an arc meeting the boundary of M at its two endpoints, or a closed curve. The αi are pairwise disjoint except for possibly sharing endpoints, and similarly for the βj. We want to “untangle” the βj from the ai by a self-homeomorphism of M; more precisely, we seek a homeomorphism φ:M→M fixing the boundary of M pointwise such that the total number of crossings of the ai with the φ(βj) is as small as possible. This problem is motivated by an application in the algorithmic theory of embeddings and 3-manifolds. We prove that if M is planar, i.e., a sphere with h ≥ 0 boundary components (“holes”), then O(mn) crossings can be achieved (independently of h), which is asymptotically tight, as an easy lower bound shows. In general, for an arbitrary (orientable or nonorientable) surface M with h holes and of (orientable or nonorientable) genus g ≥ 0, we obtain an O((m + n)4) upper bound, again independent of h and g. The proofs rely, among other things, on a result concerning simultaneous planar drawings of graphs by Erten and Kobourov.},
author = {Matoušek, Jiří and Sedgwick, Eric and Tancer, Martin and Wagner, Uli},
journal = {Israel Journal of Mathematics},
number = {1},
pages = {37 -- 79},
publisher = {Springer},
title = {{Untangling two systems of noncrossing curves}},
doi = {10.1007/s11856-016-1294-9},
volume = {212},
year = {2016},
}