TY - JOUR AB - Let U and V be two independent N by N random matrices that are distributed according to Haar measure on U(N). Let Σ be a nonnegative deterministic N by N matrix. The single ring theorem [Ann. of Math. (2) 174 (2011) 1189–1217] asserts that the empirical eigenvalue distribution of the matrix X:=UΣV∗ converges weakly, in the limit of large N, to a deterministic measure which is supported on a single ring centered at the origin in ℂ. Within the bulk regime, that is, in the interior of the single ring, we establish the convergence of the empirical eigenvalue distribution on the optimal local scale of order N−1/2+ε and establish the optimal convergence rate. The same results hold true when U and V are Haar distributed on O(N). AU - Bao, Zhigang AU - Erdös, László AU - Schnelli, Kevin ID - 6511 IS - 3 JF - Annals of Probability SN - 00911798 TI - Local single ring theorem on optimal scale VL - 47 ER - TY - JOUR AB - Branching morphogenesis is a prototypical example of complex three-dimensional organ sculpting, required in multiple developmental settings to maximize the area of exchange surfaces. It requires, in particular, the coordinated growth of different cell types together with complex patterning to lead to robust macroscopic outputs. In recent years, novel multiscale quantitative biology approaches, together with biophysical modelling, have begun to shed new light of this topic. Here, we wish to review some of these recent developments, highlighting the generic design principles that can be abstracted across different branched organs, as well as the implications for the broader fields of stem cell, developmental and systems biology. AU - Hannezo, Edouard B AU - Simons, Benjamin D. ID - 6559 JF - Current Opinion in Cell Biology SN - 09550674 TI - Multiscale dynamics of branching morphogenesis VL - 60 ER - TY - JOUR AB - Methodologies that involve the use of nanoparticles as “artificial atoms” to rationally build materials in a bottom-up fashion are particularly well-suited to control the matter at the nanoscale. Colloidal synthetic routes allow for an exquisite control over such “artificial atoms” in terms of size, shape, and crystal phase as well as core and surface compositions. We present here a bottom-up approach to produce Pb–Ag–K–S–Te nanocomposites, which is a highly promising system for thermoelectric energy conversion. First, we developed a high-yield and scalable colloidal synthesis route to uniform lead sulfide (PbS) nanorods, whose tips are made of silver sulfide (Ag2S). We then took advantage of the large surface-to-volume ratio to introduce a p-type dopant (K) by replacing native organic ligands with K2Te. Upon thermal consolidation, K2Te-surface modified PbS–Ag2S nanorods yield p-type doped nanocomposites with PbTe and PbS as major phases and Ag2S and Ag2Te as embedded nanoinclusions. Thermoelectric characterization of such consolidated nanosolids showed a high thermoelectric figure-of-merit of 1 at 620 K. AU - Ibáñez, Maria AU - Genç, Aziz AU - Hasler, Roger AU - Liu, Yu AU - Dobrozhan, Oleksandr AU - Nazarenko, Olga AU - Mata, María de la AU - Arbiol, Jordi AU - Cabot, Andreu AU - Kovalenko, Maksym V. ID - 6566 IS - 6 JF - ACS Nano KW - colloidal nanoparticles KW - asymmetric nanoparticles KW - inorganic ligands KW - heterostructures KW - catalyst assisted growth KW - nanocomposites KW - thermoelectrics SN - 1936-0851 TI - Tuning transport properties in thermoelectric nanocomposites through inorganic ligands and heterostructured building blocks VL - 13 ER - TY - JOUR AB - Acute myeloid leukemia (AML) is a heterogeneous disease with respect to its genetic and molecular basis and to patients´ outcome. Clinical, cytogenetic, and mutational data are used to classify patients into risk groups with different survival, however, within-group heterogeneity is still an issue. Here, we used a robust likelihood-based survival modeling approach and publicly available gene expression data to identify a minimal number of genes whose combined expression values were prognostic of overall survival. The resulting gene expression signature (4-GES) consisted of 4 genes (SOCS2, IL2RA, NPDC1, PHGDH), predicted patient survival as an independent prognostic parameter in several cohorts of AML patients (total, 1272 patients), and further refined prognostication based on the European Leukemia Net classification. An oncogenic role of the top scoring gene in this signature, SOCS2, was investigated using MLL-AF9 and Flt3-ITD/NPM1c driven mouse models of AML. SOCS2 promoted leukemogenesis as well as the abundance, quiescence, and activity of AML stem cells. Overall, the 4-GES represents a highly discriminating prognostic parameter in AML, whose clinical applicability is greatly enhanced by its small number of genes. The newly established role of SOCS2 in leukemia aggressiveness and stemness raises the possibility that the signature might even be exploitable therapeutically. AU - Nguyen, Chi Huu AU - Glüxam, Tobias AU - Schlerka, Angela AU - Bauer, Katharina AU - Grandits, Alexander M. AU - Hackl, Hubert AU - Dovey, Oliver AU - Zöchbauer-Müller, Sabine AU - Cooper, Jonathan L. AU - Vassiliou, George S. AU - Stoiber, Dagmar AU - Wieser, Rotraud AU - Heller, Gerwin ID - 6607 IS - 1 JF - Scientific Reports TI - SOCS2 is part of a highly prognostic 4-gene signature in AML and promotes disease aggressiveness VL - 9 ER - TY - JOUR AB - Mechanical systems facilitate the development of a hybrid quantum technology comprising electrical, optical, atomic and acoustic degrees of freedom1, and entanglement is essential to realize quantum-enabled devices. Continuous-variable entangled fields—known as Einstein–Podolsky–Rosen (EPR) states—are spatially separated two-mode squeezed states that can be used for quantum teleportation and quantum communication2. In the optical domain, EPR states are typically generated using nondegenerate optical amplifiers3, and at microwave frequencies Josephson circuits can serve as a nonlinear medium4,5,6. An outstanding goal is to deterministically generate and distribute entangled states with a mechanical oscillator, which requires a carefully arranged balance between excitation, cooling and dissipation in an ultralow noise environment. Here we observe stationary emission of path-entangled microwave radiation from a parametrically driven 30-micrometre-long silicon nanostring oscillator, squeezing the joint field operators of two thermal modes by 3.40 decibels below the vacuum level. The motion of this micromechanical system correlates up to 50 photons per second per hertz, giving rise to a quantum discord that is robust with respect to microwave noise7. Such generalized quantum correlations of separable states are important for quantum-enhanced detection8 and provide direct evidence of the non-classical nature of the mechanical oscillator without directly measuring its state9. This noninvasive measurement scheme allows to infer information about otherwise inaccessible objects, with potential implications for sensing, open-system dynamics and fundamental tests of quantum gravity. In the future, similar on-chip devices could be used to entangle subsystems on very different energy scales, such as microwave and optical photons. AU - Barzanjeh, Shabir AU - Redchenko, Elena AU - Peruzzo, Matilda AU - Wulf, Matthias AU - Lewis, Dylan AU - Arnold, Georg M AU - Fink, Johannes M ID - 6609 JF - Nature TI - Stationary entangled radiation from micromechanical motion VL - 570 ER - TY - JOUR AB - It is well known that many problems in image recovery, signal processing, and machine learning can be modeled as finding zeros of the sum of maximal monotone and Lipschitz continuous monotone operators. Many papers have studied forward-backward splitting methods for finding zeros of the sum of two monotone operators in Hilbert spaces. Most of the proposed splitting methods in the literature have been proposed for the sum of maximal monotone and inverse-strongly monotone operators in Hilbert spaces. In this paper, we consider splitting methods for finding zeros of the sum of maximal monotone operators and Lipschitz continuous monotone operators in Banach spaces. We obtain weak and strong convergence results for the zeros of the sum of maximal monotone and Lipschitz continuous monotone operators in Banach spaces. Many already studied problems in the literature can be considered as special cases of this paper. AU - Shehu, Yekini ID - 6596 IS - 4 JF - Results in Mathematics SN - 1422-6383 TI - Convergence results of forward-backward algorithms for sum of monotone operators in Banach spaces VL - 74 ER - TY - JOUR AB - There is increasing evidence that both mechanical and biochemical signals play important roles in development and disease. The development of complex organisms, in particular, has been proposed to rely on the feedback between mechanical and biochemical patterning events. This feedback occurs at the molecular level via mechanosensation but can also arise as an emergent property of the system at the cellular and tissue level. In recent years, dynamic changes in tissue geometry, flow, rheology, and cell fate specification have emerged as key platforms of mechanochemical feedback loops in multiple processes. Here, we review recent experimental and theoretical advances in understanding how these feedbacks function in development and disease. AU - Hannezo, Edouard B AU - Heisenberg, Carl-Philipp J ID - 6601 IS - 1 JF - Cell SN - 00928674 TI - Mechanochemical feedback loops in development and disease VL - 178 ER - TY - JOUR AB - The effective large-scale properties of materials with random heterogeneities on a small scale are typically determined by the method of representative volumes: a sample of the random material is chosen—the representative volume—and its effective properties are computed by the cell formula. Intuitively, for a fixed sample size it should be possible to increase the accuracy of the method by choosing a material sample which captures the statistical properties of the material particularly well; for example, for a composite material consisting of two constituents, one would select a representative volume in which the volume fraction of the constituents matches closely with their volume fraction in the overall material. Inspired by similar attempts in materials science, Le Bris, Legoll and Minvielle have designed a selection approach for representative volumes which performs remarkably well in numerical examples of linear materials with moderate contrast. In the present work, we provide a rigorous analysis of this selection approach for representative volumes in the context of stochastic homogenization of linear elliptic equations. In particular, we prove that the method essentially never performs worse than a random selection of the material sample and may perform much better if the selection criterion for the material samples is chosen suitably. AU - Fischer, Julian L ID - 6617 IS - 2 JF - Archive for Rational Mechanics and Analysis SN - 0003-9527 TI - The choice of representative volumes in the approximation of effective properties of random materials VL - 234 ER - TY - JOUR AB - Cell polarity is crucial for the coordinated development of all multicellular organisms. In plants, this is exemplified by the PIN-FORMED (PIN) efflux carriers of the phytohormone auxin: The polar subcellular localization of the PINs is instructive to the directional intercellular auxin transport, and thus to a plethora of auxin-regulated growth and developmental processes. Despite its importance, the regulation of PIN polar subcellular localization remains poorly understood. Here, we have employed advanced live-cell imaging techniques to study the roles of microtubules and actin microfilaments in the establishment of apical polar localization of PIN2 in the epidermis of the Arabidopsis root meristem. We report that apical PIN2 polarity requires neither intact actin microfilaments nor microtubules, suggesting that the primary spatial cue for polar PIN distribution is likely independent of cytoskeleton-guided endomembrane trafficking. AU - Glanc, Matous AU - Fendrych, Matyas AU - Friml, Jiří ID - 6611 IS - 6 JF - Biomolecules TI - PIN2 polarity establishment in arabidopsis in the absence of an intact cytoskeleton VL - 9 ER - TY - JOUR AB - This paper establishes an asymptotic formula with a power-saving error term for the number of rational points of bounded height on the singular cubic surface of ℙ3ℚ given by the following equation 𝑥0(𝑥21+𝑥22)−𝑥33=0 in agreement with the Manin-Peyre conjectures. AU - De La Bretèche, Régis AU - Destagnol, Kevin N AU - Liu, Jianya AU - Wu, Jie AU - Zhao, Yongqiang ID - 6620 IS - 12 JF - Science China Mathematics SN - 16747283 TI - On a certain non-split cubic surface VL - 62 ER - TY - JOUR AB - The environment changes constantly at various time scales and, in order to survive, species need to keep adapting. Whether these species succeed in avoiding extinction is a major evolutionary question. Using a multilocus evolutionary model of a mutation‐limited population adapting under strong selection, we investigate the effects of the frequency of environmental fluctuations on adaptation. Our results rely on an “adaptive‐walk” approximation and use mathematical methods from evolutionary computation theory to investigate the interplay between fluctuation frequency, the similarity of environments, and the number of loci contributing to adaptation. First, we assume a linear additive fitness function, but later generalize our results to include several types of epistasis. We show that frequent environmental changes prevent populations from reaching a fitness peak, but they may also prevent the large fitness loss that occurs after a single environmental change. Thus, the population can survive, although not thrive, in a wide range of conditions. Furthermore, we show that in a frequently changing environment, the similarity of threats that a population faces affects the level of adaptation that it is able to achieve. We check and supplement our analytical results with simulations. AU - Trubenova, Barbora AU - Krejca, Martin AU - Lehre, Per Kristian AU - Kötzing, Timo ID - 6637 IS - 7 JF - Evolution TI - Surfing on the seascape: Adaptation in a changing environment VL - 73 ER - TY - JOUR AB - In this paper we prove several new results around Gromov's waist theorem. We give a simple proof of Vaaler's theorem on sections of the unit cube using the Borsuk-Ulam-Crofton technique, consider waists of real and complex projective spaces, flat tori, convex bodies in Euclidean space; and establish waist-type results in terms of the Hausdorff measure. AU - Akopyan, Arseniy AU - Hubard, Alfredo AU - Karasev, Roman ID - 6634 IS - 2 JF - Topological Methods in Nonlinear Analysis TI - Lower and upper bounds for the waists of different spaces VL - 53 ER - TY - JOUR AB - The crossing number of a graph G is the least number of crossings over all possible drawings of G. We present a structural characterization of graphs with crossing number one. AU - Silva, André AU - Arroyo Guevara, Alan M AU - Richter, Bruce AU - Lee, Orlando ID - 6638 IS - 11 JF - Discrete Mathematics SN - 0012-365X TI - Graphs with at most one crossing VL - 342 ER - TY - JOUR AB - The spatiotemporal organization of cell divisions constitutes an integral part in the development of multicellular organisms, and mis-regulation of cell divisions can lead to severe developmental defects. Cell divisions have an important morphogenetic function in development by regulating growth and shape acquisition of developing tissues, and, conversely, tissue morphogenesis is known to affect both the rate and orientation of cell divisions. Moreover, cell divisions are associated with an extensive reorganization of the cytoskeleton and adhesion apparatus in the dividing cells that in turn can affect large-scale tissue rheological properties. Thus, the interplay between cell divisions and tissue morphogenesis plays a key role in embryo and tissue morphogenesis. AU - Godard, Benoit G AU - Heisenberg, Carl-Philipp J ID - 6631 JF - Current Opinion in Cell Biology SN - 0955-0674 TI - Cell division and tissue mechanics VL - 60 ER - TY - JOUR AB - Commercially available full-color 3D printing allows for detailed control of material deposition in a volume, but an exact reproduction of a target surface appearance is hampered by the strong subsurface scattering that causes nontrivial volumetric cross-talk at the print surface. Previous work showed how an iterative optimization scheme based on accumulating absorptive materials at the surface can be used to find a volumetric distribution of print materials that closely approximates a given target appearance. In this work, we first revisit the assumption that pushing the absorptive materials to the surface results in minimal volumetric cross-talk. We design a full-fledged optimization on a small domain for this task and confirm this previously reported heuristic. Then, we extend the above approach that is critically limited to color reproduction on planar surfaces, to arbitrary 3D shapes. Our method enables high-fidelity color texture reproduction on 3D prints by effectively compensating for internal light scattering within arbitrarily shaped objects. In addition, we propose a content-aware gamut mapping that significantly improves color reproduction for the pathological case of thin geometric features. Using a wide range of sample objects with complex textures and geometries, we demonstrate color reproduction whose fidelity is superior to state-of-the-art drivers for color 3D printers. AU - Sumin, Denis AU - Weyrich, Tim AU - Rittig, Tobias AU - Babaei, Vahid AU - Nindel, Thomas AU - Wilkie, Alexander AU - Didyk, Piotr AU - Bickel, Bernd AU - Křivánek, Jaroslav AU - Myszkowski, Karol ID - 6660 IS - 4 JF - ACM Transactions on Graphics SN - 0730-0301 TI - Geometry-aware scattering compensation for 3D printing VL - 38 ER - TY - JOUR AB - New genes are a major source of novelties, and a disproportionate amount of them are known to show testis expression in later phases of male gametogenesis in different groups such as mammals and plants. Here, we propose that this enhanced expression is a consequence of haploid selection during the latter stages of male gametogenesis. Because emerging adaptive mutations will be fixed faster if their phenotypes are expressed by haploid rather than diploid genotypes, new genes with advantageous functions arising during this unique stage of development have a better chance to become fixed. To test this hypothesis, expression levels of genes of differing evolutionary age were examined at various stages of Drosophila spermatogenesis. We found, consistent with a model based on haploid selection, that new Drosophila genes are both expressed in later haploid phases of spermatogenesis and harbor a significant enrichment of adaptive mutations. Additionally, the observed overexpression of new genes in the latter phases of spermatogenesis was limited to the autosomes. Because all male cells exhibit hemizygous expression for X-linked genes (and therefore effectively haploid), there is no expectation that selection acting on late spermatogenesis will have a different effect on X-linked genes in comparison to initial diploid phases. Together, our proposed hypothesis and the analyzed data suggest that natural selection in haploid cells elucidates several aspects of the origin of new genes by explaining the general prevalence of their testis expression, and a parsimonious solution for new alleles to avoid being lost by genetic drift or pseudogenization. AU - Raices, Julia AU - Otto, Paulo AU - Vibranovski, Maria ID - 6658 IS - 7 JF - Genome Research TI - Haploid selection drives new gene male germline expression VL - 29 ER - TY - JOUR AB - We propose a novel technique for the automatic design of molds to cast highly complex shapes. The technique generates composite, two-piece molds. Each mold piece is made up of a hard plastic shell and a flexible silicone part. Thanks to the thin, soft, and smartly shaped silicone part, which is kept in place by a hard plastic shell, we can cast objects of unprecedented complexity. An innovative algorithm based on a volumetric analysis defines the layout of the internal cuts in the silicone mold part. Our approach can robustly handle thin protruding features and intertwined topologies that have caused previous methods to fail. We compare our results with state of the art techniques, and we demonstrate the casting of shapes with extremely complex geometry. AU - Alderighi, Thomas AU - Malomo, Luigi AU - Giorgi, Daniela AU - Bickel, Bernd AU - Cignoni, Paolo AU - Pietroni, Nico ID - 6650 IS - 4 JF - ACM Transactions on Graphics SN - 0730-0301 TI - Volume-aware design of composite molds VL - 38 ER - TY - JOUR AB - With the recent publication by Silpe and Bassler (2019), considering phage detection of a bacterial quorum-sensing (QS) autoinducer, we now have as many as five examples of phage-associated intercellular communication (Table 1). Each potentially involves ecological inferences by phages as to concentrations of surrounding phage-infected or uninfected bacteria. While the utility of phage detection of bacterial QS molecules may at first glance appear to be straightforward, we suggest in this commentary that the underlying ecological explanation is unlikely to be simple. AU - Igler, Claudia AU - Abedon, Stephen T. ID - 6717 JF - Frontiers in Microbiology TI - Commentary: A host-produced quorum-sensing autoinducer controls a phage lysis-lysogeny decision VL - 10 ER - TY - JOUR AB - This paper analyzes how partial selfing in a large source population influences its ability to colonize a new habitat via the introduction of a few founder individuals. Founders experience inbreeding depression due to partially recessive deleterious alleles as well as maladaptation to the new environment due to selection on a large number of additive loci. I first introduce a simplified version of the Inbreeding History Model (Kelly, 2007) in order to characterize mutation‐selection balance in a large, partially selfing source population under selection involving multiple non‐identical loci. I then use individual‐based simulations to study the eco‐evolutionary dynamics of founders establishing in the new habitat under a model of hard selection. The study explores how selfing rate shapes establishment probabilities of founders via effects on both inbreeding depression and adaptability to the new environment, and also distinguishes the effects of selfing on the initial fitness of founders from its effects on the long‐term adaptive response of the populations they found. A high rate of (but not complete) selfing is found to aid establishment over a wide range of parameters, even in the absence of mate limitation. The sensitivity of the results to assumptions about the nature of polygenic selection are discussed. AU - Sachdeva, Himani ID - 6680 IS - 9 JF - Evolution SN - 0014-3820 TI - Effect of partial selfing and polygenic selection on establishment in a new habitat VL - 73 ER - TY - JOUR AB - Sexual dimorphism in morphology, physiology or life history traits is common in dioecious plants at reproductive maturity, but it is typically inconspicuous or absent in juveniles. Although plants of different sexes probably begin to diverge in gene expression both before their reproduction commences and before dimorphism becomes readily apparent, to our knowledge transcriptome-wide differential gene expression has yet to be demonstrated for any angiosperm species. AU - Cossard, Guillaume AU - Toups, Melissa A AU - Pannell, John ID - 6710 IS - 7 JF - Annals of botany SN - 0305-7364 TI - Sexual dimorphism and rapid turnover in gene expression in pre-reproductive seedlings of a dioecious herb VL - 123 ER -