@article{8944, abstract = {Superconductor insulator transition in transverse magnetic field is studied in the highly disordered MoC film with the product of the Fermi momentum and the mean free path kF*l close to unity. Surprisingly, the Zeeman paramagnetic effects dominate over orbital coupling on both sides of the transition. In superconducting state it is evidenced by a high upper critical magnetic field đ”đ‘2, by its square root dependence on temperature, as well as by the Zeeman splitting of the quasiparticle density of states (DOS) measured by scanning tunneling microscopy. At đ”đ‘2 a logarithmic anomaly in DOS is observed. This anomaly is further enhanced in increasing magnetic field, which is explained by the Zeeman splitting of the Altshuler-Aronov DOS driving the system into a more insulating or resistive state. Spin dependent Altshuler-Aronov correction is also needed to explain the transport behavior above đ”đ‘2.}, author = {Zemlicka, Martin and Kopčík, M. and SzabĂł, P. and Samuely, T. and Kačmarčík, J. and Neilinger, P. and Grajcar, M. and Samuely, P.}, issn = {24699969}, journal = {Physical Review B}, number = {18}, publisher = {American Physical Society}, title = {{Zeeman-driven superconductor-insulator transition in strongly disordered MoC films: Scanning tunneling microscopy and transport studies in a transverse magnetic field}}, doi = {10.1103/PhysRevB.102.180508}, volume = {102}, year = {2020}, } @article{8949, abstract = {Development of the nervous system undergoes important transitions, including one from neurogenesis to gliogenesis which occurs late during embryonic gestation. Here we report on clonal analysis of gliogenesis in mice using Mosaic Analysis with Double Markers (MADM) with quantitative and computational methods. Results reveal that developmental gliogenesis in the cerebral cortex occurs in a fraction of earlier neurogenic clones, accelerating around E16.5, and giving rise to both astrocytes and oligodendrocytes. Moreover, MADM-based genetic deletion of the epidermal growth factor receptor (Egfr) in gliogenic clones revealed that Egfr is cell autonomously required for gliogenesis in the mouse dorsolateral cortices. A broad range in the proliferation capacity, symmetry of clones, and competitive advantage of MADM cells was evident in clones that contained one cellular lineage with double dosage of Egfr relative to their environment, while their sibling Egfr-null cells failed to generate glia. Remarkably, the total numbers of glia in MADM clones balance out regardless of significant alterations in clonal symmetries. The variability in glial clones shows stochastic patterns that we define mathematically, which are different from the deterministic patterns in neuronal clones. This study sets a foundation for studying the biological significance of stochastic and deterministic clonal principles underlying tissue development, and identifying mechanisms that differentiate between neurogenesis and gliogenesis.}, author = {Zhang, Xuying and Mennicke, Christine V. and Xiao, Guanxi and Beattie, Robert J and Haider, Mansoor and Hippenmeyer, Simon and Ghashghaei, H. Troy}, issn = {2073-4409}, journal = {Cells}, number = {12}, publisher = {MDPI}, title = {{Clonal analysis of gliogenesis in the cerebral cortex reveals stochastic expansion of glia and cell autonomous responses to Egfr dosage}}, doi = {10.3390/cells9122662}, volume = {9}, year = {2020}, } @misc{8951, abstract = {Gene expression levels are influenced by multiple coexisting molecular mechanisms. Some of these interactions, such as those of transcription factors and promoters have been studied extensively. However, predicting phenotypes of gene regulatory networks remains a major challenge. Here, we use a well-defined synthetic gene regulatory network to study how network phenotypes depend on local genetic context, i.e. the genetic neighborhood of a transcription factor and its relative position. We show that one gene regulatory network with fixed topology can display not only quantitatively but also qualitatively different phenotypes, depending solely on the local genetic context of its components. Our results demonstrate that changes in local genetic context can place a single transcriptional unit within two separate regulons without the need for complex regulatory sequences. We propose that relative order of individual transcriptional units, with its potential for combinatorial complexity, plays an important role in shaping phenotypes of gene regulatory networks.}, author = {Nagy-Staron, Anna A}, keywords = {Gene regulatory networks, Gene expression, Escherichia coli, Synthetic Biology}, publisher = {Institute of Science and Technology Austria}, title = {{Sequences of gene regulatory network permutations for the article "Local genetic context shapes the function of a gene regulatory network"}}, doi = {10.15479/AT:ISTA:8951}, year = {2020}, } @article{8955, abstract = {Skeletal muscle activity is continuously modulated across physiologic states to provide coordination, flexibility and responsiveness to body tasks and external inputs. Despite the central role the muscular system plays in facilitating vital body functions, the network of brain-muscle interactions required to control hundreds of muscles and synchronize their activation in relation to distinct physiologic states has not been investigated. Recent approaches have focused on general associations between individual brain rhythms and muscle activation during movement tasks. However, the specific forms of coupling, the functional network of cortico-muscular coordination, and how network structure and dynamics are modulated by autonomic regulation across physiologic states remains unknown. To identify and quantify the cortico-muscular interaction network and uncover basic features of neuro-autonomic control of muscle function, we investigate the coupling between synchronous bursts in cortical rhythms and peripheral muscle activation during sleep and wake. Utilizing the concept of time delay stability and a novel network physiology approach, we find that the brain-muscle network exhibits complex dynamic patterns of communication involving multiple brain rhythms across cortical locations and different electromyographic frequency bands. Moreover, our results show that during each physiologic state the cortico-muscular network is characterized by a specific profile of network links strength, where particular brain rhythms play role of main mediators of interaction and control. Further, we discover a hierarchical reorganization in network structure across physiologic states, with high connectivity and network link strength during wake, intermediate during REM and light sleep, and low during deep sleep, a sleep-stage stratification that demonstrates a unique association between physiologic states and cortico-muscular network structure. The reported empirical observations are consistent across individual subjects, indicating universal behavior in network structure and dynamics, and high sensitivity of cortico-muscular control to changes in autonomic regulation, even at low levels of physical activity and muscle tone during sleep. Our findings demonstrate previously unrecognized basic principles of brain-muscle network communication and control, and provide new perspectives on the regulatory mechanisms of brain dynamics and locomotor activation, with potential clinical implications for neurodegenerative, movement and sleep disorders, and for developing efficient treatment strategies.}, author = {Rizzo, Rossella and Zhang, Xiyun and Wang, Jilin W.J.L. and Lombardi, Fabrizio and Ivanov, Plamen Ch}, issn = {1664042X}, journal = {Frontiers in Physiology}, publisher = {Frontiers}, title = {{Network physiology of cortico–muscular interactions}}, doi = {10.3389/fphys.2020.558070}, volume = {11}, year = {2020}, } @article{8957, abstract = {Global tissue tension anisotropy has been shown to trigger stereotypical cell division orientation by elongating mitotic cells along the main tension axis. Yet, how tissue tension elongates mitotic cells despite those cells undergoing mitotic rounding (MR) by globally upregulating cortical actomyosin tension remains unclear. We addressed this question by taking advantage of ascidian embryos, consisting of a small number of interphasic and mitotic blastomeres and displaying an invariant division pattern. We found that blastomeres undergo MR by locally relaxing cortical tension at their apex, thereby allowing extrinsic pulling forces from neighboring interphasic blastomeres to polarize their shape and thus division orientation. Consistently, interfering with extrinsic forces by reducing the contractility of interphasic blastomeres or disrupting the establishment of asynchronous mitotic domains leads to aberrant mitotic cell division orientations. Thus, apical relaxation during MR constitutes a key mechanism by which tissue tension anisotropy controls stereotypical cell division orientation.}, author = {Godard, Benoit G and Dumollard, RĂ©mi and Munro, Edwin and Chenevert, Janet and Hebras, CĂ©line and Mcdougall, Alex and Heisenberg, Carl-Philipp J}, issn = {18781551}, journal = {Developmental Cell}, number = {6}, pages = {695--706}, publisher = {Elsevier}, title = {{Apical relaxation during mitotic rounding promotes tension-oriented cell division}}, doi = {10.1016/j.devcel.2020.10.016}, volume = {55}, year = {2020}, } @phdthesis{8958, abstract = {The oft-quoted dictum by Arthur Schawlow: ``A diatomic molecule has one atom too many'' has been disavowed. Inspired by the possibility to experimentally manipulate and enhance chemical reactivity in helium nanodroplets, we investigate the rotation of coupled cold molecules in the presence of a many-body environment. In this thesis, we introduce new variational approaches to quantum impurities and apply them to the Fröhlich polaron - a quasiparticle formed out of an electron (or other point-like impurity) in a polar medium, and to the angulon - a quasiparticle formed out of a rotating molecule in a bosonic bath. With this theoretical toolbox, we reveal the self-localization transition for the angulon quasiparticle. We show that, unlike for polarons, self-localization of angulons occurs at finite impurity-bath coupling already at the mean-field level. The transition is accompanied by the spherical-symmetry breaking of the angulon ground state and a discontinuity in the first derivative of the ground-state energy. Moreover, the type of symmetry breaking is dictated by the symmetry of the microscopic impurity-bath interaction, which leads to a number of distinct self-localized states. For the system containing multiple impurities, by analogy with the bipolaron, we introduce the biangulon quasiparticle describing two rotating molecules that align with respect to each other due to the effective attractive interaction mediated by the excitations of the bath. We study this system from the strong-coupling regime to the weak molecule-bath interaction regime. We show that the molecules tend to have a strong alignment in the ground state, the biangulon shows shifted angulon instabilities and an additional spectral instability, where resonant angular momentum transfer between the molecules and the bath takes place. Finally, we introduce a diagonalization scheme that allows us to describe the transition from two separated angulons to a biangulon as a function of the distance between the two molecules.}, author = {Li, Xiang}, issn = {2663-337X}, pages = {125}, publisher = {Institute of Science and Technology Austria}, title = {{Rotation of coupled cold molecules in the presence of a many-body environment}}, doi = {10.15479/AT:ISTA:8958}, year = {2020}, } @article{8971, abstract = {The actin-related protein (Arp)2/3 complex nucleates branched actin filament networks pivotal for cell migration, endocytosis and pathogen infection. Its activation is tightly regulated and involves complex structural rearrangements and actin filament binding, which are yet to be understood. Here, we report a 9.0 Å resolution structure of the actin filament Arp2/3 complex branch junction in cells using cryo-electron tomography and subtomogram averaging. This allows us to generate an accurate model of the active Arp2/3 complex in the branch junction and its interaction with actin filaments. Notably, our model reveals a previously undescribed set of interactions of the Arp2/3 complex with the mother filament, significantly different to the previous branch junction model. Our structure also indicates a central role for the ArpC3 subunit in stabilizing the active conformation.}, author = {FĂ€ĂŸler, Florian and Dimchev, Georgi A and Hodirnau, Victor-Valentin and Wan, William and Schur, Florian KM}, issn = {2041-1723}, journal = {Nature Communications}, keywords = {General Biochemistry, Genetics and Molecular Biology, General Physics and Astronomy, General Chemistry}, publisher = {Springer Nature}, title = {{Cryo-electron tomography structure of Arp2/3 complex in cells reveals new insights into the branch junction}}, doi = {10.1038/s41467-020-20286-x}, volume = {11}, year = {2020}, } @article{8973, abstract = {We consider the symmetric simple exclusion process in Zd with quenched bounded dynamic random conductances and prove its hydrodynamic limit in path space. The main tool is the connection, due to the self-duality of the process, between the invariance principle for single particles starting from all points and the macroscopic behavior of the density field. While the hydrodynamic limit at fixed macroscopic times is obtained via a generalization to the time-inhomogeneous context of the strategy introduced in [41], in order to prove tightness for the sequence of empirical density fields we develop a new criterion based on the notion of uniform conditional stochastic continuity, following [50]. In conclusion, we show that uniform elliptic dynamic conductances provide an example of environments in which the so-called arbitrary starting point invariance principle may be derived from the invariance principle of a single particle starting from the origin. Therefore, our hydrodynamics result applies to the examples of quenched environments considered in, e.g., [1], [3], [6] in combination with the hypothesis of uniform ellipticity.}, author = {Redig, Frank and Saada, Ellen and Sau, Federico}, issn = {1083-6489}, journal = {Electronic Journal of Probability}, publisher = { Institute of Mathematical Statistics}, title = {{Symmetric simple exclusion process in dynamic environment: Hydrodynamics}}, doi = {10.1214/20-EJP536}, volume = {25}, year = {2020}, } @article{8978, abstract = {Mosaic analysis with double markers (MADM) technology enables concomitant fluorescent cell labeling and induction of uniparental chromosome disomy (UPD) with single-cell resolution. In UPD, imprinted genes are either overexpressed 2-fold or are not expressed. Here, the MADM platform is utilized to probe imprinting phenotypes at the transcriptional level. This protocol highlights major steps for the generation and isolation of projection neurons and astrocytes with MADM-induced UPD from mouse cerebral cortex for downstream single-cell and low-input sample RNA-sequencing experiments. For complete details on the use and execution of this protocol, please refer to Laukoter et al. (2020b).}, author = {Laukoter, Susanne and Amberg, Nicole and Pauler, Florian and Hippenmeyer, Simon}, issn = {2666-1667}, journal = {STAR Protocols}, number = {3}, publisher = {Elsevier}, title = {{Generation and isolation of single cells from mouse brain with mosaic analysis with double markers-induced uniparental chromosome disomy}}, doi = {10.1016/j.xpro.2020.100215}, volume = {1}, year = {2020}, } @phdthesis{8983, abstract = {Metabolic adaptation is a critical feature of migrating cells. It tunes the metabolic programs of migrating cells to allow them to efficiently exert their crucial roles in development, inflammatory responses and tumor metastasis. Cell migration through physically challenging contexts requires energy. However, how the metabolic reprogramming that underlies in vivo cell invasion is controlled is still unanswered. In my PhD project, I identify a novel conserved metabolic shift in Drosophila melanogaster immune cells that by modulating their bioenergetic potential controls developmentally programmed tissue invasion. We show that this regulation requires a novel conserved nuclear protein, named Atossa. Atossa enhances the transcription of a set of proteins, including an RNA helicase Porthos and two metabolic enzymes, each of which increases the tissue invasion of leading Drosophila macrophages and can rescue the atossa mutant phenotype. Porthos selectively regulates the translational efficiency of a subset of mRNAs containing a 5’-UTR cis-regulatory TOP-like sequence. These 5’TOPL mRNA targets encode mitochondrial-related proteins, including subunits of mitochondrial oxidative phosphorylation (OXPHOS) components III and V and other metabolic-related proteins. Porthos powers up mitochondrial OXPHOS to engender a sufficient ATP supply, which is required for tissue invasion of leading macrophages. Atossa’s two vertebrate orthologs rescue the invasion defect. In my PhD project, I elucidate that Atossa displays a conserved developmental metabolic control to modulate metabolic capacities and the cellular energy state, through altered transcription and translation, to aid the tissue infiltration of leading cells into energy demanding barriers.}, author = {Emtenani, Shamsi}, issn = {2663-337X}, pages = {141}, publisher = {Institute of Science and Technology Austria}, title = {{Metabolic regulation of Drosophila macrophage tissue invasion}}, doi = {10.15479/AT:ISTA:8983}, year = {2020}, } @article{8986, abstract = {Flowering plants display the highest diversity among plant species and have notably shaped terrestrial landscapes. Nonetheless, the evolutionary origin of their unprecedented morphological complexity remains largely an enigma. Here, we show that the coevolution of cis-regulatory and coding regions of PIN-FORMED (PIN) auxin transporters confined their expression to certain cell types and directed their subcellular localization to particular cell sides, which together enabled dynamic auxin gradients across tissues critical to the complex architecture of flowering plants. Extensive intraspecies and interspecies genetic complementation experiments with PINs from green alga up to flowering plant lineages showed that PIN genes underwent three subsequent, critical evolutionary innovations and thus acquired a triple function to regulate the development of three essential components of the flowering plant Arabidopsis: shoot/root, inflorescence, and floral organ. Our work highlights the critical role of functional innovations within the PIN gene family as essential prerequisites for the origin of flowering plants.}, author = {Zhang, Yuzhou and Rodriguez Solovey, Lesia and Li, Lanxin and Zhang, Xixi and Friml, Jiƙí}, issn = {2375-2548}, journal = {Science Advances}, number = {50}, publisher = {AAAS}, title = {{Functional innovations of PIN auxin transporters mark crucial evolutionary transitions during rise of flowering plants}}, doi = {10.1126/sciadv.abc8895}, volume = {6}, year = {2020}, } @inproceedings{8987, abstract = {Currently several projects aim at designing and implementing protocols for privacy preserving automated contact tracing to help fight the current pandemic. Those proposal are quite similar, and in their most basic form basically propose an app for mobile phones which broadcasts frequently changing pseudorandom identifiers via (low energy) Bluetooth, and at the same time, the app stores IDs broadcast by phones in its proximity. Only if a user is tested positive, they upload either the beacons they did broadcast (which is the case in decentralized proposals as DP-3T, east and west coast PACT or Covid watch) or received (as in Popp-PT or ROBERT) during the last two weeks or so. Vaudenay [eprint 2020/399] observes that this basic scheme (he considers the DP-3T proposal) succumbs to relay and even replay attacks, and proposes more complex interactive schemes which prevent those attacks without giving up too many privacy aspects. Unfortunately interaction is problematic for this application for efficiency and security reasons. The countermeasures that have been suggested so far are either not practical or give up on key privacy aspects. We propose a simple non-interactive variant of the basic protocol that (security) Provably prevents replay and (if location data is available) relay attacks. (privacy) The data of all parties (even jointly) reveals no information on the location or time where encounters happened. (efficiency) The broadcasted message can fit into 128 bits and uses only basic crypto (commitments and secret key authentication). Towards this end we introduce the concept of “delayed authentication”, which basically is a message authentication code where verification can be done in two steps, where the first doesn’t require the key, and the second doesn’t require the message.}, author = {Pietrzak, Krzysztof Z}, booktitle = {Progress in Cryptology}, isbn = {9783030652760}, issn = {16113349}, location = {Bangalore, India}, pages = {3--15}, publisher = {Springer Nature}, title = {{Delayed authentication: Preventing replay and relay attacks in private contact tracing}}, doi = {10.1007/978-3-030-65277-7_1}, volume = {12578}, year = {2020}, } @article{9000, abstract = {In prokaryotes, thermodynamic models of gene regulation provide a highly quantitative mapping from promoter sequences to gene-expression levels that is compatible with in vivo and in vitro biophysical measurements. Such concordance has not been achieved for models of enhancer function in eukaryotes. In equilibrium models, it is difficult to reconcile the reported short transcription factor (TF) residence times on the DNA with the high specificity of regulation. In nonequilibrium models, progress is difficult due to an explosion in the number of parameters. Here, we navigate this complexity by looking for minimal nonequilibrium enhancer models that yield desired regulatory phenotypes: low TF residence time, high specificity, and tunable cooperativity. We find that a single extra parameter, interpretable as the “linking rate,” by which bound TFs interact with Mediator components, enables our models to escape equilibrium bounds and access optimal regulatory phenotypes, while remaining consistent with the reported phenomenology and simple enough to be inferred from upcoming experiments. We further find that high specificity in nonequilibrium models is in a trade-off with gene-expression noise, predicting bursty dynamics—an experimentally observed hallmark of eukaryotic transcription. By drastically reducing the vast parameter space of nonequilibrium enhancer models to a much smaller subspace that optimally realizes biological function, we deliver a rich class of models that could be tractably inferred from data in the near future.}, author = {Grah, Rok and Zoller, Benjamin and Tkačik, GaĆĄper}, issn = {10916490}, journal = {PNAS}, number = {50}, pages = {31614--31622}, publisher = {National Academy of Sciences}, title = {{Nonequilibrium models of optimal enhancer function}}, doi = {10.1073/pnas.2006731117}, volume = {117}, year = {2020}, } @inproceedings{9001, abstract = {Quantum illumination is a sensing technique that employs entangled signal-idler beams to improve the detection efficiency of low-reflectivity objects in environments with large thermal noise. The advantage over classical strategies is evident at low signal brightness, a feature which could make the protocol an ideal prototype for non-invasive scanning or low-power short-range radar. Here we experimentally investigate the concept of quantum illumination at microwave frequencies, by generating entangled fields using a Josephson parametric converter which are then amplified to illuminate a room-temperature object at a distance of 1 meter. Starting from experimental data, we simulate the case of perfect idler photon number detection, which results in a quantum advantage compared to the relative classical benchmark. Our results highlight the opportunities and challenges on the way towards a first room-temperature application of microwave quantum circuits.}, author = {Barzanjeh, Shabir and Pirandola, Stefano and Vitali, David and Fink, Johannes M}, booktitle = {IEEE National Radar Conference - Proceedings}, isbn = {9781728189420}, issn = {1097-5659}, location = {Florence, Italy}, number = {9}, publisher = {IEEE}, title = {{Microwave quantum illumination with a digital phase-conjugated receiver}}, doi = {10.1109/RadarConf2043947.2020.9266397}, volume = {2020}, year = {2020}, } @article{9007, abstract = {Motivated by a recent question of Peyre, we apply the Hardy–Littlewood circle method to count “sufficiently free” rational points of bounded height on arbitrary smooth projective hypersurfaces of low degree that are defined over the rationals.}, author = {Browning, Timothy D and Sawin, Will}, issn = {14208946}, journal = {Commentarii Mathematici Helvetici}, number = {4}, pages = {635--659}, publisher = {European Mathematical Society}, title = {{Free rational points on smooth hypersurfaces}}, doi = {10.4171/CMH/499}, volume = {95}, year = {2020}, } @article{9011, abstract = {Distributed ledgers provide high availability and integrity, making them a key enabler for practical and secure computation of distributed workloads among mutually distrustful parties. Many practical applications also require strong confidentiality, however. This work enhances permissioned and permissionless blockchains with the ability to manage confidential data without forfeiting availability or decentralization. The proposed Calypso architecture addresses two orthogonal challenges confronting modern distributed ledgers: (a) enabling the auditable management of secrets and (b) protecting distributed computations against arbitrage attacks when their results depend on the ordering and secrecy of inputs. Calypso introduces on-chain secrets, a novel abstraction that enforces atomic deposition of an auditable trace whenever users access confidential data. Calypso provides user-controlled consent management that ensures revocation atomicity and accountable anonymity. To enable permissionless deployment, we introduce an incentive scheme and provide users with the option to select their preferred trustees. We evaluated our Calypso prototype with a confidential document-sharing application and a decentralized lottery. Our benchmarks show that transaction-processing latency increases linearly in terms of security (number of trustees) and is in the range of 0.2 to 8 seconds for 16 to 128 trustees.}, author = {Kokoris Kogias, Eleftherios and Alp, Enis Ceyhun and Gasser, Linus and Jovanovic, Philipp and Syta, Ewa and Ford, Bryan}, issn = {2150-8097}, journal = {Proceedings of the VLDB Endowment}, number = {4}, pages = {586--599}, publisher = {Association for Computing Machinery}, title = {{CALYPSO: Private data management for decentralized ledgers}}, doi = {10.14778/3436905.3436917}, volume = {14}, year = {2020}, } @article{9039, abstract = {We give a short and self-contained proof for rates of convergence of the Allen--Cahn equation towards mean curvature flow, assuming that a classical (smooth) solution to the latter exists and starting from well-prepared initial data. Our approach is based on a relative entropy technique. In particular, it does not require a stability analysis for the linearized Allen--Cahn operator. As our analysis also does not rely on the comparison principle, we expect it to be applicable to more complex equations and systems.}, author = {Fischer, Julian L and Laux, Tim and Simon, Theresa M.}, issn = {10957154}, journal = {SIAM Journal on Mathematical Analysis}, number = {6}, pages = {6222--6233}, publisher = {Society for Industrial and Applied Mathematics}, title = {{Convergence rates of the Allen-Cahn equation to mean curvature flow: A short proof based on relative entropies}}, doi = {10.1137/20M1322182}, volume = {52}, year = {2020}, } @inproceedings{9040, abstract = {Machine learning and formal methods have complimentary benefits and drawbacks. In this work, we address the controller-design problem with a combination of techniques from both fields. The use of black-box neural networks in deep reinforcement learning (deep RL) poses a challenge for such a combination. Instead of reasoning formally about the output of deep RL, which we call the wizard, we extract from it a decision-tree based model, which we refer to as the magic book. Using the extracted model as an intermediary, we are able to handle problems that are infeasible for either deep RL or formal methods by themselves. First, we suggest, for the first time, a synthesis procedure that is based on a magic book. We synthesize a stand-alone correct-by-design controller that enjoys the favorable performance of RL. Second, we incorporate a magic book in a bounded model checking (BMC) procedure. BMC allows us to find numerous traces of the plant under the control of the wizard, which a user can use to increase the trustworthiness of the wizard and direct further training.}, author = {Alamdari, Par Alizadeh and Avni, Guy and Henzinger, Thomas A and Lukina, Anna}, booktitle = {Proceedings of the 20th Conference on Formal Methods in Computer-Aided Design}, isbn = {9783854480426}, issn = {2708-7824}, location = {Online Conference}, pages = {138--147}, publisher = {TU Wien Academic Press}, title = {{Formal methods with a touch of magic}}, doi = {10.34727/2020/isbn.978-3-85448-042-6_21}, year = {2020}, } @article{9054, abstract = {The fundamental and practical importance of particle stabilization has motivated various characterization methods for studying polymer brushes on particle surfaces. In this work, we show how one can perform sensitive measurements of neutral polymer coating on colloidal particles using a commercial zetameter and salt solutions. By systematically varying the Debye length, we study the mobility of the polymer-coated particles in an applied electric field and show that the electrophoretic mobility of polymer-coated particles normalized by the mobility of non-coated particles is entirely controlled by the polymer brush and independent of the native surface charge, here controlled with pH, or the surface–ion interaction. Our result is rationalized with a simple hydrodynamic model, allowing for the estimation of characteristics of the polymer coating: the brush length L, and the Brinkman length Ο, determined by its resistance to flows. We demonstrate that the Debye layer provides a convenient and faithful probe to the characterization of polymer coatings on particles. Because the method simply relies on a conventional zetameter, it is widely accessible and offers a practical tool to rapidly probe neutral polymer brushes, an asset in the development and utilization of polymer-coated colloidal particles.}, author = {Youssef, Mena and Morin, Alexandre and Aubret, Antoine and Sacanna, Stefano and Palacci, JĂ©rĂ©mie A}, issn = {1744-6848}, journal = {Soft Matter}, keywords = {General Chemistry, Condensed Matter Physics}, number = {17}, pages = {4274--4282}, publisher = {Royal Society of Chemistry }, title = {{Rapid characterization of neutral polymer brush with a conventional zetameter and a variable pinch of salt}}, doi = {10.1039/c9sm01850f}, volume = {16}, year = {2020}, } @article{9059, abstract = {From rock salt to nanoparticle superlattices, complex structure can emerge from simple building blocks that attract each other through Coulombic forces1-4. On the micrometre scale, however, colloids in water defy the intuitively simple idea of forming crystals from oppositely charged partners, instead forming non-equilibrium structures such as clusters and gels5-7. Although various systems have been engineered to grow binary crystals8-11, native surface charge in aqueous conditions has not been used to assemble crystalline materials. Here we form ionic colloidal crystals in water through an approach that we refer to as polymer-attenuated Coulombic self-assembly. The key to crystallization is the use of a neutral polymer to keep particles separated by well defined distances, allowing us to tune the attractive overlap of electrical double layers, directing particles to disperse, crystallize or become permanently fixed on demand. The nucleation and growth of macroscopic single crystals is demonstrated by using the Debye screening length to fine-tune assembly. Using a variety of colloidal particles and commercial polymers, ionic colloidal crystals isostructural to caesium chloride, sodium chloride, aluminium diboride and K4C60 are selected according to particle size ratios. Once fixed by simply diluting out solution salts, crystals are pulled out of the water for further manipulation, demonstrating an accurate translation from solution-phase assembly to dried solid structures. In contrast to other assembly approaches, in which particles must be carefully engineered to encode binding information12-18, polymer-attenuated Coulombic self-assembly enables conventional colloids to be used as model colloidal ions, primed for crystallization. }, author = {Hueckel, Theodore and Hocky, Glen M. and Palacci, JĂ©rĂ©mie A and Sacanna, Stefano}, issn = {1476-4687}, journal = {Nature}, keywords = {Multidisciplinary}, number = {7804}, pages = {487--490}, publisher = {Springer Nature}, title = {{Ionic solids from common colloids}}, doi = {10.1038/s41586-020-2205-0}, volume = {580}, year = {2020}, }