@inproceedings{609,
abstract = {Several cryptographic schemes and applications are based on functions that are both reasonably efficient to compute and moderately hard to invert, including client puzzles for Denial-of-Service protection, password protection via salted hashes, or recent proof-of-work blockchain systems. Despite their wide use, a definition of this concept has not yet been distilled and formalized explicitly. Instead, either the applications are proven directly based on the assumptions underlying the function, or some property of the function is proven, but the security of the application is argued only informally. The goal of this work is to provide a (universal) definition that decouples the efforts of designing new moderately hard functions and of building protocols based on them, serving as an interface between the two. On a technical level, beyond the mentioned definitions, we instantiate the model for four different notions of hardness. We extend the work of Alwen and Serbinenko (STOC 2015) by providing a general tool for proving security for the first notion of memory-hard functions that allows for provably secure applications. The tool allows us to recover all of the graph-theoretic techniques developed for proving security under the older, non-composable, notion of security used by Alwen and Serbinenko. As an application of our definition of moderately hard functions, we prove the security of two different schemes for proofs of effort (PoE). We also formalize and instantiate the concept of a non-interactive proof of effort (niPoE), in which the proof is not bound to a particular communication context but rather any bit-string chosen by the prover.},
author = {Alwen, Joel F and Tackmann, Björn},
editor = {Kalai, Yael and Reyzin, Leonid},
isbn = {978-331970499-9},
location = {Baltimore, MD, United States},
pages = {493 -- 526},
publisher = {Springer},
title = {{Moderately hard functions: Definition, instantiations, and applications}},
doi = {10.1007/978-3-319-70500-2_17},
volume = {10677},
year = {2017},
}
@article{610,
abstract = {The fact that the complete graph K5 does not embed in the plane has been generalized in two independent directions. On the one hand, the solution of the classical Heawood problem for graphs on surfaces established that the complete graph Kn embeds in a closed surface M (other than the Klein bottle) if and only if (n−3)(n−4) ≤ 6b1(M), where b1(M) is the first Z2-Betti number of M. On the other hand, van Kampen and Flores proved that the k-skeleton of the n-dimensional simplex (the higher-dimensional analogue of Kn+1) embeds in R2k if and only if n ≤ 2k + 1. Two decades ago, Kühnel conjectured that the k-skeleton of the n-simplex embeds in a compact, (k − 1)-connected 2k-manifold with kth Z2-Betti number bk only if the following generalized Heawood inequality holds: (k+1 n−k−1) ≤ (k+1 2k+1)bk. This is a common generalization of the case of graphs on surfaces as well as the van Kampen–Flores theorem. In the spirit of Kühnel’s conjecture, we prove that if the k-skeleton of the n-simplex embeds in a compact 2k-manifold with kth Z2-Betti number bk, then n ≤ 2bk(k 2k+2)+2k+4. This bound is weaker than the generalized Heawood inequality, but does not require the assumption that M is (k−1)-connected. Our results generalize to maps without q-covered points, in the spirit of Tverberg’s theorem, for q a prime power. Our proof uses a result of Volovikov about maps that satisfy a certain homological triviality condition.},
author = {Goaoc, Xavier and Mabillard, Isaac and Paták, Pavel and Patakova, Zuzana and Tancer, Martin and Wagner, Uli},
journal = {Israel Journal of Mathematics},
number = {2},
pages = {841 -- 866},
publisher = {Springer},
title = {{On generalized Heawood inequalities for manifolds: A van Kampen–Flores type nonembeddability result}},
doi = {10.1007/s11856-017-1607-7},
volume = {222},
year = {2017},
}
@article{611,
abstract = {Small RNAs (sRNAs) regulate genes in plants and animals. Here, we show that population-wide differences in color patterns in snapdragon flowers are caused by an inverted duplication that generates sRNAs. The complexity and size of the transcripts indicate that the duplication represents an intermediate on the pathway to microRNA evolution. The sRNAs repress a pigment biosynthesis gene, creating a yellow highlight at the site of pollinator entry. The inverted duplication exhibits steep clines in allele frequency in a natural hybrid zone, showing that the allele is under selection. Thus, regulatory interactions of evolutionarily recent sRNAs can be acted upon by selection and contribute to the evolution of phenotypic diversity.},
author = {Bradley, Desmond and Xu, Ping and Mohorianu, Irina and Whibley, Annabel and Field, David and Tavares, Hugo and Couchman, Matthew and Copsey, Lucy and Carpenter, Rosemary and Li, Miaomiao and Li, Qun and Xue, Yongbiao and Dalmay, Tamas and Coen, Enrico},
issn = {00368075},
journal = {Science},
number = {6365},
pages = {925 -- 928},
publisher = {American Association for the Advancement of Science},
title = {{Evolution of flower color pattern through selection on regulatory small RNAs}},
doi = {10.1126/science.aao3526},
volume = {358},
year = {2017},
}
@article{613,
abstract = {Bacteria in groups vary individually, and interact with other bacteria and the environment to produce population-level patterns of gene expression. Investigating such behavior in detail requires measuring and controlling populations at the single-cell level alongside precisely specified interactions and environmental characteristics. Here we present an automated, programmable platform that combines image-based gene expression and growth measurements with on-line optogenetic expression control for hundreds of individual Escherichia coli cells over days, in a dynamically adjustable environment. This integrated platform broadly enables experiments that bridge individual and population behaviors. We demonstrate: (i) population structuring by independent closed-loop control of gene expression in many individual cells, (ii) cell-cell variation control during antibiotic perturbation, (iii) hybrid bio-digital circuits in single cells, and freely specifiable digital communication between individual bacteria. These examples showcase the potential for real-time integration of theoretical models with measurement and control of many individual cells to investigate and engineer microbial population behavior.},
author = {Chait, Remy P and Ruess, Jakob and Bergmiller, Tobias and Tkacik, Gasper and Guet, Calin C},
issn = {20411723},
journal = {Nature Communications},
number = {1},
publisher = {Nature Publishing Group},
title = {{Shaping bacterial population behavior through computer interfaced control of individual cells}},
doi = {10.1038/s41467-017-01683-1},
volume = {8},
year = {2017},
}
@article{614,
abstract = {Moths and butterflies (Lepidoptera) usually have a pair of differentiated WZ sex chromosomes. However, in most lineages outside of the division Ditrysia, as well as in the sister order Trichoptera, females lack a W chromosome. The W is therefore thought to have been acquired secondarily. Here we compare the genomes of three Lepidoptera species (one Dytrisia and two non-Dytrisia) to test three models accounting for the origin of the W: (1) a Z-autosome fusion; (2) a sex chromosome turnover; and (3) a non-canonical mechanism (e.g., through the recruitment of a B chromosome). We show that the gene content of the Z is highly conserved across Lepidoptera (rejecting a sex chromosome turnover) and that very few genes moved onto the Z in the common ancestor of the Ditrysia (arguing against a Z-autosome fusion). Our comparative genomics analysis therefore supports the secondary acquisition of the Lepidoptera W by a non-canonical mechanism, and it confirms the extreme stability of well-differentiated sex chromosomes.},
author = {Fraisse, Christelle and Picard, Marion A and Vicoso, Beatriz},
issn = {20411723},
journal = {Nature Communications},
number = {1},
publisher = {Nature Publishing Group},
title = {{The deep conservation of the Lepidoptera Z chromosome suggests a non canonical origin of the W}},
doi = {10.1038/s41467-017-01663-5},
volume = {8},
year = {2017},
}
@article{615,
abstract = {We show that the Dyson Brownian Motion exhibits local universality after a very short time assuming that local rigidity and level repulsion of the eigenvalues hold. These conditions are verified, hence bulk spectral universality is proven, for a large class of Wigner-like matrices, including deformed Wigner ensembles and ensembles with non-stochastic variance matrices whose limiting densities differ from Wigner's semicircle law.},
author = {Erdös, László and Schnelli, Kevin},
issn = {02460203},
journal = {Annales de l'institut Henri Poincare (B) Probability and Statistics},
number = {4},
pages = {1606 -- 1656},
publisher = {Institute of Mathematical Statistics},
title = {{Universality for random matrix flows with time dependent density}},
doi = {10.1214/16-AIHP765},
volume = {53},
year = {2017},
}
@article{6196,
abstract = {PMAC is a simple and parallel block-cipher mode of operation, which was introduced by Black and Rogaway at Eurocrypt 2002. If instantiated with a (pseudo)random permutation over n-bit strings, PMAC constitutes a provably secure variable input-length (pseudo)random function. For adversaries making q queries, each of length at most l (in n-bit blocks), and of total length σ ≤ ql, the original paper proves an upper bound on the distinguishing advantage of Ο(σ2/2n), while the currently best bound is Ο (qσ/2n).In this work we show that this bound is tight by giving an attack with advantage Ω (q2l/2n). In the PMAC construction one initially XORs a mask to every message block, where the mask for the ith block is computed as τi := γi·L, where L is a (secret) random value, and γi is the i-th codeword of the Gray code. Our attack applies more generally to any sequence of γi’s which contains a large coset of a subgroup of GF(2n). We then investigate if the security of PMAC can be further improved by using τi’s that are k-wise independent, for k > 1 (the original distribution is only 1-wise independent). We observe that the security of PMAC will not increase in general, even if the masks are chosen from a 2-wise independent distribution, and then prove that the security increases to O(q<2/2n), if the τi are 4-wise independent. Due to simple extension attacks, this is the best bound one can hope for, using any distribution on the masks. Whether 3-wise independence is already sufficient to get this level of security is left as an open problem.},
author = {Gazi, Peter and Pietrzak, Krzysztof Z and Rybar, Michal},
issn = {2519-173X},
journal = {IACR Transactions on Symmetric Cryptology},
number = {2},
pages = {145--161},
publisher = {Ruhr University Bochum},
title = {{The exact security of PMAC}},
doi = {10.13154/TOSC.V2016.I2.145-161},
volume = {2016},
year = {2017},
}
@article{621,
abstract = {The mammalian cerebral cortex is responsible for higher cognitive functions such as perception, consciousness, and acquiring and processing information. The neocortex is organized into six distinct laminae, each composed of a rich diversity of cell types which assemble into highly complex cortical circuits. Radial glia progenitors (RGPs) are responsible for producing all neocortical neurons and certain glia lineages. Here, we discuss recent discoveries emerging from clonal lineage analysis at the single RGP cell level that provide us with an inaugural quantitative framework of RGP lineage progression. We further discuss the importance of the relative contribution of intrinsic gene functions and non-cell-autonomous or community effects in regulating RGP proliferation behavior and lineage progression.},
author = {Beattie, Robert J and Hippenmeyer, Simon},
issn = {00145793},
journal = {FEBS letters},
number = {24},
pages = {3993 -- 4008},
publisher = {Wiley-Blackwell},
title = {{Mechanisms of radial glia progenitor cell lineage progression}},
doi = {10.1002/1873-3468.12906},
volume = {591},
year = {2017},
}
@inbook{623,
abstract = {Genetic factors might be largely responsible for the development of autism spectrum disorder (ASD) that alone or in combination with specific environmental risk factors trigger the pathology. Multiple mutations identified in ASD patients that impair synaptic function in the central nervous system are well studied in animal models. How these mutations might interact with other risk factors is not fully understood though. Additionally, how systems outside of the brain are altered in the context of ASD is an emerging area of research. Extracerebral influences on the physiology could begin in utero and contribute to changes in the brain and in the development of other body systems and further lead to epigenetic changes. Therefore, multiple recent studies have aimed at elucidating the role of gene-environment interactions in ASD. Here we provide an overview on the extracerebral systems that might play an important associative role in ASD and review evidence regarding the potential roles of inflammation, trace metals, metabolism, genetic susceptibility, enteric nervous system function and the microbiota of the gastrointestinal (GI) tract on the development of endophenotypes in animal models of ASD. By influencing environmental conditions, it might be possible to reduce or limit the severity of ASD pathology.},
author = {Hill Yardin, Elisa and Mckeown, Sonja and Novarino, Gaia and Grabrucker, Andreas},
booktitle = {Translational Anatomy and Cell Biology of Autism Spectrum Disorder},
editor = {Schmeisser, Michael and Boekers, Tobias},
isbn = {978-3-319-52496-2},
issn = {03015556},
pages = {159 -- 187},
publisher = {Springer},
title = {{Extracerebral dysfunction in animal models of autism spectrum disorder}},
doi = {10.1007/978-3-319-52498-6_9},
volume = {224},
year = {2017},
}
@article{624,
abstract = {Bacteria adapt to adverse environmental conditions by altering gene expression patterns. Recently, a novel stress adaptation mechanism has been described that allows Escherichia coli to alter gene expression at the post-transcriptional level. The key player in this regulatory pathway is the endoribonuclease MazF, the toxin component of the toxin-antitoxin module mazEF that is triggered by various stressful conditions. In general, MazF degrades the majority of transcripts by cleaving at ACA sites, which results in the retardation of bacterial growth. Furthermore, MazF can process a small subset of mRNAs and render them leaderless by removing their ribosome binding site. MazF concomitantly modifies ribosomes, making them selective for the translation of leaderless mRNAs. In this study, we employed fluorescent reporter-systems to investigate mazEF expression during stressful conditions, and to infer consequences of the mRNA processing mediated by MazF on gene expression at the single-cell level. Our results suggest that mazEF transcription is maintained at low levels in single cells encountering adverse conditions, such as antibiotic stress or amino acid starvation. Moreover, using the grcA mRNA as a model for MazF-mediated mRNA processing, we found that MazF activation promotes heterogeneity in the grcA reporter expression, resulting in a subpopulation of cells with increased levels of GrcA reporter protein.},
author = {Nikolic, Nela and Didara, Zrinka and Moll, Isabella},
issn = {21678359},
journal = {PeerJ},
number = {9},
publisher = {PeerJ},
title = {{MazF activation promotes translational heterogeneity of the grcA mRNA in Escherichia coli populations}},
doi = {10.7717/peerj.3830},
volume = {2017},
year = {2017},
}