@article{14404, abstract = {A light-triggered fabrication method extends the functionality of printable nanomaterials}, author = {Balazs, Daniel and Ibáñez, Maria}, issn = {1095-9203}, journal = {Science}, number = {6665}, pages = {1413--1414}, publisher = {AAAS}, title = {{Widening the use of 3D printing}}, doi = {10.1126/science.adk3070}, volume = {381}, year = {2023}, } @inproceedings{14417, abstract = {Entropic risk (ERisk) is an established risk measure in finance, quantifying risk by an exponential re-weighting of rewards. We study ERisk for the first time in the context of turn-based stochastic games with the total reward objective. This gives rise to an objective function that demands the control of systems in a risk-averse manner. We show that the resulting games are determined and, in particular, admit optimal memoryless deterministic strategies. This contrasts risk measures that previously have been considered in the special case of Markov decision processes and that require randomization and/or memory. We provide several results on the decidability and the computational complexity of the threshold problem, i.e. whether the optimal value of ERisk exceeds a given threshold. In the most general case, the problem is decidable subject to Shanuel’s conjecture. If all inputs are rational, the resulting threshold problem can be solved using algebraic numbers, leading to decidability via a polynomial-time reduction to the existential theory of the reals. Further restrictions on the encoding of the input allow the solution of the threshold problem in NP∩coNP. Finally, an approximation algorithm for the optimal value of ERisk is provided.}, author = {Baier, Christel and Chatterjee, Krishnendu and Meggendorfer, Tobias and Piribauer, Jakob}, booktitle = {48th International Symposium on Mathematical Foundations of Computer Science}, isbn = {9783959772921}, issn = {1868-8969}, location = {Bordeaux, France}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Entropic risk for turn-based stochastic games}}, doi = {10.4230/LIPIcs.MFCS.2023.15}, volume = {272}, year = {2023}, } @article{12960, abstract = {Isomanifolds are the generalization of isosurfaces to arbitrary dimension and codimension, i.e., submanifolds of Rd defined as the zero set of some multivariate multivalued smooth function f:Rd→Rd−n, where n is the intrinsic dimension of the manifold. A natural way to approximate a smooth isomanifold M=f−1(0) is to consider its piecewise linear (PL) approximation M^ based on a triangulation T of the ambient space Rd. In this paper, we describe a simple algorithm to trace isomanifolds from a given starting point. The algorithm works for arbitrary dimensions n and d, and any precision D. Our main result is that, when f (or M) has bounded complexity, the complexity of the algorithm is polynomial in d and δ=1/D (and unavoidably exponential in n). Since it is known that for δ=Ω(d2.5), M^ is O(D2)-close and isotopic to M , our algorithm produces a faithful PL-approximation of isomanifolds of bounded complexity in time polynomial in d. Combining this algorithm with dimensionality reduction techniques, the dependency on d in the size of M^ can be completely removed with high probability. We also show that the algorithm can handle isomanifolds with boundary and, more generally, isostratifolds. The algorithm for isomanifolds with boundary has been implemented and experimental results are reported, showing that it is practical and can handle cases that are far ahead of the state-of-the-art. }, author = {Boissonnat, Jean Daniel and Kachanovich, Siargey and Wintraecken, Mathijs}, issn = {1095-7111}, journal = {SIAM Journal on Computing}, number = {2}, pages = {452--486}, publisher = {Society for Industrial and Applied Mathematics}, title = {{Tracing isomanifolds in Rd in time polynomial in d using Coxeter–Freudenthal–Kuhn triangulations}}, doi = {10.1137/21M1412918}, volume = {52}, year = {2023}, } @article{13134, abstract = {We propose a characterization of discrete analytical spheres, planes and lines in the body-centered cubic (BCC) grid, both in the Cartesian and in the recently proposed alternative compact coordinate system, in which each integer triplet addresses some voxel in the grid. We define spheres and planes through double Diophantine inequalities and investigate their relevant topological features, such as functionality or the interrelation between the thickness of the objects and their connectivity and separation properties. We define lines as the intersection of planes. The number of the planes (up to six) is equal to the number of the pairs of faces of a BCC voxel that are parallel to the line.}, author = {Čomić, Lidija and Largeteau-Skapin, Gaëlle and Zrour, Rita and Biswas, Ranita and Andres, Eric}, issn = {0031-3203}, journal = {Pattern Recognition}, number = {10}, publisher = {Elsevier}, title = {{Discrete analytical objects in the body-centered cubic grid}}, doi = {10.1016/j.patcog.2023.109693}, volume = {142}, year = {2023}, } @article{13216, abstract = {Physical catalysts often have multiple sites where reactions can take place. One prominent example is single-atom alloys, where the reactive dopant atoms can preferentially locate in the bulk or at different sites on the surface of the nanoparticle. However, ab initio modeling of catalysts usually only considers one site of the catalyst, neglecting the effects of multiple sites. Here, nanoparticles of copper doped with single-atom rhodium or palladium are modeled for the dehydrogenation of propane. Single-atom alloy nanoparticles are simulated at 400–600 K, using machine learning potentials trained on density functional theory calculations, and then the occupation of different single-atom active sites is identified using a similarity kernel. Further, the turnover frequency for all possible sites is calculated for propane dehydrogenation to propene through microkinetic modeling using density functional theory calculations. The total turnover frequencies of the whole nanoparticle are then described from both the population and the individual turnover frequency of each site. Under operating conditions, rhodium as a dopant is found to almost exclusively occupy (111) surface sites while palladium as a dopant occupies a greater variety of facets. Undercoordinated dopant surface sites are found to tend to be more reactive for propane dehydrogenation compared to the (111) surface. It is found that considering the dynamics of the single-atom alloy nanoparticle has a profound effect on the calculated catalytic activity of single-atom alloys by several orders of magnitude.}, author = {Bunting, Rhys and Wodaczek, Felix and Torabi, Tina and Cheng, Bingqing}, issn = {1520-5126}, journal = {Journal of the American Chemical Society}, keywords = {Colloid and Surface Chemistry, Biochemistry, General Chemistry, Catalysis}, number = {27}, pages = {14894--14902}, publisher = {American Chemical Society}, title = {{Reactivity of single-atom alloy nanoparticles: Modeling the dehydrogenation of propane}}, doi = {10.1021/jacs.3c04030}, volume = {145}, year = {2023}, } @article{14426, abstract = {To meet the physiological demands of the body, organs need to establish a functional tissue architecture and adequate size as the embryo develops to adulthood. In the liver, uni- and bipotent progenitor differentiation into hepatocytes and biliary epithelial cells (BECs), and their relative proportions, comprise the functional architecture. Yet, the contribution of individual liver progenitors at the organ level to both fates, and their specific proportion, is unresolved. Combining mathematical modelling with organ-wide, multispectral FRaeppli-NLS lineage tracing in zebrafish, we demonstrate that a precise BEC-to-hepatocyte ratio is established (i) fast, (ii) solely by heterogeneous lineage decisions from uni- and bipotent progenitors, and (iii) independent of subsequent cell type–specific proliferation. Extending lineage tracing to adulthood determined that embryonic cells undergo spatially heterogeneous three-dimensional growth associated with distinct environments. Strikingly, giant clusters comprising almost half a ventral lobe suggest lobe-specific dominant-like growth behaviours. We show substantial hepatocyte polyploidy in juveniles representing another hallmark of postembryonic liver growth. Our findings uncover heterogeneous progenitor contributions to tissue architecture-defining cell type proportions and postembryonic organ growth as key mechanisms forming the adult liver.}, author = {Unterweger, Iris A. and Klepstad, Julie and Hannezo, Edouard B and Lundegaard, Pia R. and Trusina, Ala and Ober, Elke A.}, issn = {1545-7885}, journal = {PLoS Biology}, number = {10}, publisher = {Public Library of Science}, title = {{Lineage tracing identifies heterogeneous hepatoblast contribution to cell lineages and postembryonic organ growth dynamics}}, doi = {10.1371/journal.pbio.3002315}, volume = {21}, year = {2023}, } @inproceedings{14428, abstract = {Suppose we have two hash functions h1 and h2, but we trust the security of only one of them. To mitigate this worry, we wish to build a hash combiner Ch1,h2 which is secure so long as one of the underlying hash functions is. This question has been well-studied in the regime of collision resistance. In this case, concatenating the two hash function outputs clearly works. Unfortunately, a long series of works (Boneh and Boyen, CRYPTO’06; Pietrzak, Eurocrypt’07; Pietrzak, CRYPTO’08) showed no (noticeably) shorter combiner for collision resistance is possible. In this work, we revisit this pessimistic state of affairs, motivated by the observation that collision-resistance is insufficient for many interesting applications of cryptographic hash functions anyway. We argue the right formulation of the “hash combiner” is to build what we call random oracle (RO) combiners, utilizing stronger assumptions for stronger constructions. Indeed, we circumvent the previous lower bounds for collision resistance by constructing a simple length-preserving RO combiner C˜h1,h2Z1,Z2(M)=h1(M,Z1)⊕h2(M,Z2),where Z1,Z2 are random salts of appropriate length. We show that this extra randomness is necessary for RO combiners, and indeed our construction is somewhat tight with this lower bound. On the negative side, we show that one cannot generically apply the composition theorem to further replace “monolithic” hash functions h1 and h2 by some simpler indifferentiable construction (such as the Merkle-Damgård transformation) from smaller components, such as fixed-length compression functions. Finally, despite this issue, we directly prove collision resistance of the Merkle-Damgård variant of our combiner, where h1 and h2 are replaced by iterative Merkle-Damgård hashes applied to a fixed-length compression function. Thus, we can still subvert the concatenation barrier for collision-resistance combiners while utilizing practically small fixed-length components underneath.}, author = {Dodis, Yevgeniy and Ferguson, Niels and Goldin, Eli and Hall, Peter and Pietrzak, Krzysztof Z}, booktitle = {43rd Annual International Cryptology Conference}, isbn = {9783031385445}, issn = {1611-3349}, location = {Santa Barbara, CA, United States}, pages = {514--546}, publisher = {Springer Nature}, title = {{Random oracle combiners: Breaking the concatenation barrier for collision-resistance}}, doi = {10.1007/978-3-031-38545-2_17}, volume = {14082}, year = {2023}, } @inbook{13052, abstract = {Imaging of the immunological synapse (IS) between dendritic cells (DCs) and T cells in suspension is hampered by suboptimal alignment of cell-cell contacts along the vertical imaging plane. This requires optical sectioning that often results in unsatisfactory resolution in time and space. Here, we present a workflow where DCs and T cells are confined between a layer of glass and polydimethylsiloxane (PDMS) that orients the cells along one, horizontal imaging plane, allowing for fast en-face-imaging of the DC-T cell IS.}, author = {Leithner, Alexander F and Merrin, Jack and Sixt, Michael K}, booktitle = {The Immune Synapse}, editor = {Baldari, Cosima and Dustin, Michael}, isbn = {9781071631348}, issn = {1940-6029}, pages = {137--147}, publisher = {Springer Nature}, title = {{En-Face Imaging of T Cell-Dendritic Cell Immunological Synapses}}, doi = {10.1007/978-1-0716-3135-5_9}, volume = {2654}, year = {2023}, } @article{12406, abstract = {Let X be a sufficiently large positive integer. We prove that one may choose a subset S of primes with cardinality O(logX) such that a positive proportion of integers less than X can be represented by x2+py2 for at least one p∈S.}, author = {Diao, Yijie}, issn = {1730-6264}, journal = {Acta Arithmetica}, keywords = {Algebra, Number Theory}, pages = {1--17}, publisher = {Instytut Matematyczny}, title = {{Density of the union of positive diagonal binary quadratic forms}}, doi = {10.4064/aa210830-24-11}, volume = {207}, year = {2023}, } @article{13200, abstract = {Recent quantum technologies have established precise quantum control of various microscopic systems using electromagnetic waves. Interfaces based on cryogenic cavity electro-optic systems are particularly promising, due to the direct interaction between microwave and optical fields in the quantum regime. Quantum optical control of superconducting microwave circuits has been precluded so far due to the weak electro-optical coupling as well as quasi-particles induced by the pump laser. Here we report the coherent control of a superconducting microwave cavity using laser pulses in a multimode electro-optical device at millikelvin temperature with near-unity cooperativity. Both the stationary and instantaneous responses of the microwave and optical modes comply with the coherent electro-optical interaction, and reveal only minuscule amount of excess back-action with an unanticipated time delay. Our demonstration enables wide ranges of applications beyond quantum transductions, from squeezing and quantum non-demolition measurements of microwave fields, to entanglement generation and hybrid quantum networks.}, author = {Qiu, Liu and Sahu, Rishabh and Hease, William J and Arnold, Georg M and Fink, Johannes M}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Nature Research}, title = {{Coherent optical control of a superconducting microwave cavity via electro-optical dynamical back-action}}, doi = {10.1038/s41467-023-39493-3}, volume = {14}, year = {2023}, }