@phdthesis{15020,
abstract = {This thesis consists of four distinct pieces of work within theoretical biology, with two themes in common: the concept of optimization in biological systems, and the use of information-theoretic tools to quantify biological stochasticity and statistical uncertainty.
Chapter 2 develops a statistical framework for studying biological systems which we believe to be optimized for a particular utility function, such as retinal neurons conveying information about visual stimuli. We formalize such beliefs as maximum-entropy Bayesian priors, constrained by the expected utility. We explore how such priors aid inference of system parameters with limited data and enable optimality hypothesis testing: is the utility higher than by chance?
Chapter 3 examines the ultimate biological optimization process: evolution by natural selection. As some individuals survive and reproduce more successfully than others, populations evolve towards fitter genotypes and phenotypes. We formalize this as accumulation of genetic information, and use population genetics theory to study how much such information can be accumulated per generation and maintained in the face of random mutation and genetic drift. We identify the population size and fitness variance as the key quantities that control information accumulation and maintenance.
Chapter 4 reuses the concept of genetic information from Chapter 3, but from a different perspective: we ask how much genetic information organisms actually need, in particular in the context of gene regulation. For example, how much information is needed to bind transcription factors at correct locations within the genome? Population genetics provides us with a refined answer: with an increasing population size, populations achieve higher fitness by maintaining more genetic information. Moreover, regulatory parameters experience selection pressure to optimize the fitness-information trade-off, i.e. minimize the information needed for a given fitness. This provides an evolutionary derivation of the optimization priors introduced in Chapter 2.
Chapter 5 proves an upper bound on mutual information between a signal and a communication channel output (such as neural activity). Mutual information is an important utility measure for biological systems, but its practical use can be difficult due to the large dimensionality of many biological channels. Sometimes, a lower bound on mutual information is computed by replacing the high-dimensional channel outputs with decodes (signal estimates). Our result provides a corresponding upper bound, provided that the decodes are the maximum posterior estimates of the signal.},
author = {Hledik, Michal},
issn = {2663-337X},
keywords = {Theoretical biology, Optimality, Evolution, Information},
pages = {158},
publisher = {Institute of Science and Technology Austria},
title = {{Genetic information and biological optimization}},
doi = {10.15479/at:ista:15020},
year = {2024},
}
@article{15024,
abstract = {Electrostatic correlations between ions dissolved in water are known to impact their transport properties in numerous ways, from conductivity to ion selectivity. The effects of these correlations on the solvent itself remain, however, much less clear. In particular, the addition of salt has been consistently reported to affect the solution’s viscosity, but most modeling attempts fail to reproduce experimental data even at moderate salt concentrations. Here, we use an approach based on stochastic density functional theory, which accurately captures charge fluctuations and correlations. We derive a simple analytical expression for the viscosity correction in concentrated electrolytes, by directly linking it to the liquid’s structure factor. Our prediction compares quantitatively to experimental data at all temperatures and all salt concentrations up to the saturation limit. This universal link between the microscopic structure and viscosity allows us to shed light on the nanoscale dynamics of water and ions under highly concentrated and correlated conditions.},
author = {Robin, Paul},
issn = {1089-7690},
journal = {Journal of Chemical Physics},
number = {6},
publisher = {AIP Publishing},
title = {{Correlation-induced viscous dissipation in concentrated electrolytes}},
doi = {10.1063/5.0188215},
volume = {160},
year = {2024},
}
@article{15025,
abstract = {We consider quadratic forms of deterministic matrices A evaluated at the random eigenvectors of a large N×N GOE or GUE matrix, or equivalently evaluated at the columns of a Haar-orthogonal or Haar-unitary random matrix. We prove that, as long as the deterministic matrix has rank much smaller than √N, the distributions of the extrema of these quadratic forms are asymptotically the same as if the eigenvectors were independent Gaussians. This reduces the problem to Gaussian computations, which we carry out in several cases to illustrate our result, finding Gumbel or Weibull limiting distributions depending on the signature of A. Our result also naturally applies to the eigenvectors of any invariant ensemble.},
author = {Erdös, László and McKenna, Benjamin},
issn = {1050-5164},
journal = {Annals of Applied Probability},
number = {1B},
pages = {1623--1662},
publisher = {Institute of Mathematical Statistics},
title = {{Extremal statistics of quadratic forms of GOE/GUE eigenvectors}},
doi = {10.1214/23-AAP2000},
volume = {34},
year = {2024},
}
@article{15033,
abstract = {The GNOM (GN) Guanine nucleotide Exchange Factor for ARF small GTPases (ARF-GEF) is among the best studied trafficking regulators in plants, playing crucial and unique developmental roles in patterning and polarity. The current models place GN at the Golgi apparatus (GA), where it mediates secretion/recycling, and at the plasma membrane (PM) presumably contributing to clathrin-mediated endocytosis (CME). The mechanistic basis of the developmental function of GN, distinct from the other ARF-GEFs including its closest homologue GNOM-LIKE1 (GNL1), remains elusive. Insights from this study largely extend the current notions of GN function. We show that GN, but not GNL1, localizes to the cell periphery at long-lived structures distinct from clathrin-coated pits, while CME and secretion proceed normally in gn knockouts. The functional GN mutant variant GNfewerroots, absent from the GA, suggests that the cell periphery is the major site of GN action responsible for its developmental function. Following inhibition by Brefeldin A, GN, but not GNL1, relocates to the PM likely on exocytic vesicles, suggesting selective molecular associations en route to the cell periphery. A study of GN-GNL1 chimeric ARF-GEFs indicates that all GN domains contribute to the specific GN function in a partially redundant manner. Together, this study offers significant steps toward the elucidation of the mechanism underlying unique cellular and development functions of GNOM.},
author = {Adamowski, Maciek and Matijevic, Ivana and Friml, Jiří},
issn = {2050-084X},
journal = {eLife},
keywords = {General Immunology and Microbiology, General Biochemistry, Genetics and Molecular Biology, General Medicine, General Neuroscience},
publisher = {eLife Sciences Publications},
title = {{Developmental patterning function of GNOM ARF-GEF mediated from the cell periphery}},
doi = {10.7554/elife.68993},
volume = {13},
year = {2024},
}
@article{15045,
abstract = {Coupling of orbital motion to a spin degree of freedom gives rise to various transport phenomena in quantum systems that are beyond the standard paradigms of classical physics. Here, we discuss features of spin-orbit dynamics that can be visualized using a classical model with two coupled angular degrees of freedom. Specifically, we demonstrate classical ‘spin’ filtering through our model and show that the interplay between angular degrees of freedom and dissipation can lead to asymmetric ‘spin’ transport.},
author = {Varshney, Atul and Ghazaryan, Areg and Volosniev, Artem},
issn = {1432-5411},
journal = {Few-Body Systems},
keywords = {Atomic and Molecular Physics, and Optics},
publisher = {Springer Nature},
title = {{Classical ‘spin’ filtering with two degrees of freedom and dissipation}},
doi = {10.1007/s00601-024-01880-x},
volume = {65},
year = {2024},
}
@article{15047,
abstract = {Tropical precipitation extremes and their changes with surface warming are investigated using global storm resolving simulations and high-resolution observations. The simulations demonstrate that the mesoscale organization of convection, a process that cannot be physically represented by conventional global climate models, is important for the variations of tropical daily accumulated precipitation extremes. In both the simulations and observations, daily precipitation extremes increase in a more organized state, in association with larger, but less frequent, storms. Repeating the simulations for a warmer climate results in a robust increase in monthly-mean daily precipitation extremes. Higher precipitation percentiles have a greater sensitivity to convective organization, which is predicted to increase with warming. Without changes in organization, the strongest daily precipitation extremes over the tropical oceans increase at a rate close to Clausius-Clapeyron (CC) scaling. Thus, in a future warmer state with increased organization, the strongest daily precipitation extremes over oceans increase at a faster rate than CC scaling.},
author = {Bao, Jiawei and Stevens, Bjorn and Kluft, Lukas and Muller, Caroline J},
issn = {2375-2548},
journal = {Science Advances},
number = {8},
publisher = {American Association for the Advancement of Science},
title = {{Intensification of daily tropical precipitation extremes from more organized convection}},
doi = {10.1126/sciadv.adj6801},
volume = {10},
year = {2024},
}
@article{15053,
abstract = {Atom-based quantum simulators have had many successes in tackling challenging quantum many-body problems, owing to the precise and dynamical control that they provide over the systems' parameters. They are, however, often optimized to address a specific type of problem. Here, we present the design and implementation of a 6Li-based quantum gas platform that provides wide-ranging capabilities and is able to address a variety of quantum many-body problems. Our two-chamber architecture relies on a robust combination of gray molasses and optical transport from a laser-cooling chamber to a glass cell with excellent optical access. There, we first create unitary Fermi superfluids in a three-dimensional axially symmetric harmonic trap and characterize them using in situ thermometry, reaching temperatures below 20 nK. This allows us to enter the deep superfluid regime with samples of extreme diluteness, where the interparticle spacing is sufficiently large for direct single-atom imaging. Second, we generate optical lattice potentials with triangular and honeycomb geometry in which we study diffraction of molecular Bose-Einstein condensates, and show how going beyond the Kapitza-Dirac regime allows us to unambiguously distinguish between the two geometries. With the ability to probe quantum many-body physics in both discrete and continuous space, and its suitability for bulk and single-atom imaging, our setup represents an important step towards achieving a wide-scope quantum simulator.},
author = {Jin, Shuwei and Dai, Kunlun and Verstraten, Joris and Dixmerias, Maxime and Al Hyder, Ragheed and Salomon, Christophe and Peaudecerf, Bruno and de Jongh, Tim and Yefsah, Tarik},
issn = {2643-1564},
journal = {Physical Review Research},
keywords = {General Physics and Astronomy},
number = {1},
publisher = {American Physical Society},
title = {{Multipurpose platform for analog quantum simulation}},
doi = {10.1103/physrevresearch.6.013158},
volume = {6},
year = {2024},
}
@article{15083,
abstract = {Direct reciprocity is a powerful mechanism for cooperation in social dilemmas. The very logic of reciprocity, however, seems to require that individuals are symmetric, and that everyone has the same means to influence each others’ payoffs. Yet in many applications, individuals are asymmetric. Herein, we study the effect of asymmetry in linear public good games. Individuals may differ in their endowments (their ability to contribute to a public good) and in their productivities (how effective their contributions are). Given the individuals’ productivities, we ask which allocation of endowments is optimal for cooperation. To this end, we consider two notions of optimality. The first notion focuses on the resilience of cooperation. The respective endowment distribution ensures that full cooperation is feasible even under the most adverse conditions. The second notion focuses on efficiency. The corresponding endowment distribution maximizes group welfare. Using analytical methods, we fully characterize these two endowment distributions. This analysis reveals that both optimality notions favor some endowment inequality: More productive players ought to get higher endowments. Yet the two notions disagree on how unequal endowments are supposed to be. A focus on resilience results in less inequality. With additional simulations, we show that the optimal endowment allocation needs to account for both the resilience and the efficiency of cooperation.},
author = {Hübner, Valentin and Staab, Manuel and Hilbe, Christian and Chatterjee, Krishnendu and Kleshnina, Maria},
issn = {1091-6490},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = {10},
publisher = {National Academy of Sciences},
title = {{Efficiency and resilience of cooperation in asymmetric social dilemmas}},
doi = {10.1073/pnas.2315558121},
volume = {121},
year = {2024},
}
@inproceedings{15093,
abstract = {We present a dynamic data structure for maintaining the persistent homology of a time series of real numbers. The data structure supports local operations, including the insertion and deletion of an item and the cutting and concatenating of lists, each in time O(log n + k), in which n counts the critical items and k the changes in the augmented persistence diagram. To achieve this, we design a tailor-made tree structure with an unconventional representation, referred to as banana tree, which may be useful in its own right.},
author = {Cultrera di Montesano, Sebastiano and Edelsbrunner, Herbert and Henzinger, Monika H and Ost, Lara},
booktitle = {Proceedings of the 2024 Annual ACM-SIAM Symposium on Discrete Algorithms (SODA)},
editor = {Woodruff, David P.},
location = {Alexandria, VA, USA},
pages = {243 -- 295},
publisher = {Society for Industrial and Applied Mathematics},
title = {{Dynamically maintaining the persistent homology of time series}},
doi = {10.1137/1.9781611977912.11},
year = {2024},
}
@article{15097,
abstract = {Global storm-resolving models (GSRMs) use strongly refined horizontal grids compared with the climate models typically used in the Coupled Model Intercomparison Project (CMIP) but employ comparable vertical grid spacings. Here, we study how changes in the vertical grid spacing and adjustments to the integration time step affect the basic climate quantities simulated by the ICON-Sapphire atmospheric GSRM. Simulations are performed over a 45 d period for five different vertical grids with between 55 and 540 vertical layers and maximum tropospheric vertical grid spacings of between 800 and 50 m, respectively. The effects of changes in the vertical grid spacing are compared with the effects of reducing the horizontal grid spacing from 5 to 2.5 km. For most of the quantities considered, halving the vertical grid spacing has a smaller effect than halving the horizontal grid spacing, but it is not negligible. Each halving of the vertical grid spacing, along with the necessary reductions in time step length, increases cloud liquid water by about 7 %, compared with an approximate 16 % decrease for halving the horizontal grid spacing. The effect is due to both the vertical grid refinement and the time step reduction. There is no tendency toward convergence in the range of grid spacings tested here. The cloud ice amount also increases with a refinement in the vertical grid, but it is hardly affected by the time step length and does show a tendency to converge. While the effect on shortwave radiation is globally dominated by the altered reflection due to the change in the cloud liquid water content, the effect on longwave radiation is more difficult to interpret because changes in the cloud ice concentration and cloud fraction are anticorrelated in some regions. The simulations show that using a maximum tropospheric vertical grid spacing larger than 400 m would increase the truncation error strongly. Computing time investments in a further vertical grid refinement can affect the truncation errors of GSRMs similarly to comparable investments in horizontal refinement, because halving the vertical grid spacing is generally cheaper than halving the horizontal grid spacing. However, convergence of boundary layer cloud properties cannot be expected, even for the smallest maximum tropospheric grid spacing of 50 m used in this study.},
author = {Schmidt, Hauke and Rast, Sebastian and Bao, Jiawei and Cassim, Amrit and Fang, Shih Wei and Jimenez-De La Cuesta, Diego and Keil, Paul and Kluft, Lukas and Kroll, Clarissa and Lang, Theresa and Niemeier, Ulrike and Schneidereit, Andrea and Williams, Andrew I.L. and Stevens, Bjorn},
issn = {1991-9603},
journal = {Geoscientific Model Development},
number = {4},
pages = {1563--1584},
publisher = {European Geosciences Union},
title = {{Effects of vertical grid spacing on the climate simulated in the ICON-Sapphire global storm-resolving model}},
doi = {10.5194/gmd-17-1563-2024},
volume = {17},
year = {2024},
}
@article{15098,
abstract = {The paper is devoted to the analysis of the global well-posedness and the interior regularity of the 2D Navier–Stokes equations with inhomogeneous stochastic boundary conditions. The noise, white in time and coloured in space, can be interpreted as the physical law describing the driving mechanism on the atmosphere–ocean interface, i.e. as a balance of the shear stress of the ocean and the horizontal wind force.},
author = {Agresti, Antonio and Luongo, Eliseo},
issn = {1432-1807},
journal = {Mathematische Annalen},
pages = {2727--2766},
publisher = {Springer Nature},
title = {{Global well-posedness and interior regularity of 2D Navier-Stokes equations with stochastic boundary conditions}},
doi = {10.1007/s00208-024-02812-0},
volume = {390},
year = {2024},
}
@article{15099,
abstract = {Speciation is a key evolutionary process that is not yet fully understood. Combining population genomic and ecological data from multiple diverging pairs of marine snails (Littorina) supports the search for speciation mechanisms. Placing pairs on a one-dimensional speciation continuum, from undifferentiated populations to species, obscured the complexity of speciation. Adding multiple axes helped to describe either speciation routes or reproductive isolation in the snails. Divergent ecological selection repeatedly generated barriers between ecotypes, but appeared less important in completing speciation while genetic incompatibilities played a key role. Chromosomal inversions contributed to genomic barriers, but with variable impact. A multidimensional (hypercube) approach supported framing of questions and identification of knowledge gaps and can be useful to understand speciation in many other systems.},
author = {Johannesson, Kerstin and Faria, Rui and Le Moan, Alan and Rafajlović, Marina and Westram, Anja M and Butlin, Roger K. and Stankowski, Sean},
issn = {1362-4555},
journal = {Trends in Genetics},
number = {4},
pages = {337--351},
publisher = {Elsevier},
title = {{Diverse pathways to speciation revealed by marine snails}},
doi = {10.1016/j.tig.2024.01.002},
volume = {40},
year = {2024},
}
@misc{15108,
abstract = {in the research article "Efficiency and resilience of cooperation in asymmetric social dilemmas" (by Valentin Hübner, Manuel Staab, Christian Hilbe, Krishnendu Chatterjee, and Maria Kleshnina).
We used different implementations for the case of two and three players, both described below.},
author = {Hübner, Valentin and Kleshnina, Maria},
publisher = {Zenodo},
title = {{Computer code for "Efficiency and resilience of cooperation in asymmetric social dilemmas"}},
doi = {10.5281/ZENODO.10639167},
year = {2024},
}
@article{15114,
abstract = {As a key liquid organic hydrogen carrier, investigating the decomposition of formic acid (HCOOH) on the Pd (1 1 1) transition metal surface is imperative for harnessing hydrogen energy. Despite a multitude of studies, the major mechanisms and key intermediates involved in the dehydrogenation process of formic acid remain a great topic of debate due to ambiguous adsorbate interactions. In this research, we develop an advanced microkinetic model based on first-principles calculations, accounting for adsorbate–adsorbate interactions. Our study unveils a comprehensive mechanism for the Pd (1 1 1) surface, highlighting the significance of coverage effects in formic acid dehydrogenation. Our findings unequivocally demonstrate that H coverage on the Pd (1 1 1) surface renders formic acid more susceptible to decompose into H2 and CO2 through COOH intermediates. Consistent with experimental results, the selectivity of H2 in the decomposition of formic acid on the Pd (1 1 1) surface approaches 100 %. Considering the influence of H coverage, our kinetic analysis aligns perfectly with experimental values at a temperature of 373 K.},
author = {Yao, Zihao and Liu, Xu and Bunting, Rhys and Wang, Jianguo},
issn = {0009-2509},
journal = {Chemical Engineering Science},
publisher = {Elsevier},
title = {{Unravelling the reaction mechanism for H2 production via formic acid decomposition over Pd: Coverage-dependent microkinetic modeling}},
doi = {10.1016/j.ces.2024.119959},
volume = {291},
year = {2024},
}
@article{15116,
abstract = {Water is known to play an important role in collagen self-assembly, but it is still largely unclear how water–collagen interactions influence the assembly process and determine the fibril network properties. Here, we use the H2O/D2O isotope effect on the hydrogen-bond strength in water to investigate the role of hydration in collagen self-assembly. We dissolve collagen in H2O and D2O and compare the growth kinetics and the structure of the collagen assemblies formed in these water isotopomers. Surprisingly, collagen assembly occurs ten times faster in D2O than in H2O, and collagen in D2O self-assembles into much thinner fibrils, that form a more inhomogeneous and softer network, with a fourfold reduction in elastic modulus when compared to H2O. Combining spectroscopic measurements with atomistic simulations, we show that collagen in D2O is less hydrated than in H2O. This partial dehydration lowers the enthalpic penalty for water removal and reorganization at the collagen–water interface, increasing the self-assembly rate and the number of nucleation centers, leading to thinner fibrils and a softer network. Coarse-grained simulations show that the acceleration in the initial nucleation rate can be reproduced by the enhancement of electrostatic interactions. These results show that water acts as a mediator between collagen monomers, by modulating their interactions so as to optimize the assembly process and, thus, the final network properties. We believe that isotopically modulating the hydration of proteins can be a valuable method to investigate the role of water in protein structural dynamics and protein self-assembly.},
author = {Giubertoni, Giulia and Feng, Liru and Klein, Kevin and Giannetti, Guido and Rutten, Luco and Choi, Yeji and Van Der Net, Anouk and Castro-Linares, Gerard and Caporaletti, Federico and Micha, Dimitra and Hunger, Johannes and Deblais, Antoine and Bonn, Daniel and Sommerdijk, Nico and Šarić, Anđela and Ilie, Ioana M. and Koenderink, Gijsje H. and Woutersen, Sander},
issn = {1091-6490},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = {11},
publisher = {National Academy of Sciences},
title = {{Elucidating the role of water in collagen self-assembly by isotopically modulating collagen hydration}},
doi = {10.1073/pnas.2313162121},
volume = {121},
year = {2024},
}
@article{15117,
abstract = {The hippocampal mossy fiber synapse, formed between axons of dentate gyrus granule cells and dendrites of CA3 pyramidal neurons, is a key synapse in the trisynaptic circuitry of the hippocampus. Because of its comparatively large size, this synapse is accessible to direct presynaptic recording, allowing a rigorous investigation of the biophysical mechanisms of synaptic transmission and plasticity. Furthermore, because of its placement in the very center of the hippocampal memory circuit, this synapse seems to be critically involved in several higher network functions, such as learning, memory, pattern separation, and pattern completion. Recent work based on new technologies in both nanoanatomy and nanophysiology, including presynaptic patch-clamp recording, paired recording, super-resolution light microscopy, and freeze-fracture and “flash-and-freeze” electron microscopy, has provided new insights into the structure, biophysics, and network function of this intriguing synapse. This brings us one step closer to answering a fundamental question in neuroscience: how basic synaptic properties shape higher network computations.},
author = {Vandael, David H and Jonas, Peter M},
issn = {1095-9203},
journal = {Science},
number = {6687},
pages = {eadg6757},
publisher = {AAAS},
title = {{Structure, biophysics, and circuit function of a "giant" cortical presynaptic terminal}},
doi = {10.1126/science.adg6757},
volume = {383},
year = {2024},
}
@article{15118,
abstract = {Cell division in all domains of life requires the orchestration of many proteins, but in Archaea most of the machinery remains poorly characterized. Here we investigate the FtsZ-based cell division mechanism in Haloferax volcanii and find proteins containing photosynthetic reaction centre (PRC) barrel domains that play an essential role in archaeal cell division. We rename these proteins cell division protein B 1 (CdpB1) and CdpB2. Depletions and deletions in their respective genes cause severe cell division defects, generating drastically enlarged cells. Fluorescence microscopy of tagged FtsZ1, FtsZ2 and SepF in CdpB1 and CdpB2 mutant strains revealed an unusually disordered divisome that is not organized into a distinct ring-like structure. Biochemical analysis shows that SepF forms a tripartite complex with CdpB1/2 and crystal structures suggest that these two proteins might form filaments, possibly aligning SepF and the FtsZ2 ring during cell division. Overall our results indicate that PRC-domain proteins play essential roles in FtsZ-based cell division in Archaea.},
author = {Nußbaum, Phillip and Kureisaite-Ciziene, Danguole and Bellini, Dom and Van Der Does, Chris and Kojic, Marko and Taib, Najwa and Yeates, Anna and Tourte, Maxime and Gribaldo, Simonetta and Loose, Martin and Löwe, Jan and Albers, Sonja Verena},
issn = {2058-5276},
journal = {Nature Microbiology},
number = {3},
pages = {698--711},
publisher = {Springer Nature},
title = {{Proteins containing photosynthetic reaction centre domains modulate FtsZ-based archaeal cell division}},
doi = {10.1038/s41564-024-01600-5},
volume = {9},
year = {2024},
}
@article{15122,
abstract = {Quantum computers are increasing in size and quality but are still very noisy. Error mitigation extends the size of the quantum circuits that noisy devices can meaningfully execute. However, state-of-the-art error mitigation methods are hard to implement and the limited qubit connectivity in superconducting qubit devices restricts most applications to the hardware's native topology. Here we show a quantum approximate optimization algorithm (QAOA) on nonplanar random regular graphs with up to 40 nodes enabled by a machine learning-based error mitigation. We use a swap network with careful decision-variable-to-qubit mapping and a feed-forward neural network to optimize a depth-two QAOA on up to 40 qubits. We observe a meaningful parameter optimization for the largest graph which requires running quantum circuits with 958 two-qubit gates. Our paper emphasizes the need to mitigate samples, and not only expectation values, in quantum approximate optimization. These results are a step towards executing quantum approximate optimization at a scale that is not classically simulable. Reaching such system sizes is key to properly understanding the true potential of heuristic algorithms like QAOA.},
author = {Sack, Stefan and Egger, Daniel J.},
issn = {2643-1564},
journal = {Physical Review Research},
number = {1},
publisher = {American Physical Society},
title = {{Large-scale quantum approximate optimization on nonplanar graphs with machine learning noise mitigation}},
doi = {10.1103/PhysRevResearch.6.013223},
volume = {6},
year = {2024},
}
@article{15146,
abstract = {The extracellular matrix (ECM) serves as a scaffold for cells and plays an essential role in regulating numerous cellular processes, including cell migration and proliferation. Due to limitations in specimen preparation for conventional room-temperature electron microscopy, we lack structural knowledge on how ECM components are secreted, remodeled, and interact with surrounding cells. We have developed a 3D-ECM platform compatible with sample thinning by cryo-focused ion beam milling, the lift-out extraction procedure, and cryo-electron tomography. Our workflow implements cell-derived matrices (CDMs) grown on EM grids, resulting in a versatile tool closely mimicking ECM environments. This allows us to visualize ECM for the first time in its hydrated, native context. Our data reveal an intricate network of extracellular fibers, their positioning relative to matrix-secreting cells, and previously unresolved structural entities. Our workflow and results add to the structural atlas of the ECM, providing novel insights into its secretion and assembly.},
author = {Zens, Bettina and Fäßler, Florian and Hansen, Jesse and Hauschild, Robert and Datler, Julia and Hodirnau, Victor-Valentin and Zheden, Vanessa and Alanko, Jonna H and Sixt, Michael K and Schur, Florian KM},
issn = {1540-8140},
journal = {Journal of Cell Biology},
number = {6},
publisher = {Rockefeller University Press},
title = {{Lift-out cryo-FIBSEM and cryo-ET reveal the ultrastructural landscape of extracellular matrix}},
doi = {10.1083/jcb.202309125},
volume = {223},
year = {2024},
}
@article{15163,
abstract = {For some k∈Z≥0∪{∞}, we call a linear forest k-bounded if each of its components has at most k edges. We will say a (k,ℓ)-bounded linear forest decomposition of a graph G is a partition of E(G) into the edge sets of two linear forests Fk,Fℓ where Fk is k-bounded and Fℓ is ℓ-bounded. We show that the problem of deciding whether a given graph has such a decomposition is NP-complete if both k and ℓ are at least 2, NP-complete if k≥9 and ℓ=1, and is in P for (k,ℓ)=(2,1). Before this, the only known NP-complete cases were the (2,2) and (3,3) cases. Our hardness result answers a question of Bermond et al. from 1984. We also show that planar graphs of girth at least nine decompose into a linear forest and a matching, which in particular is stronger than 3-edge-colouring such graphs.},
author = {Campbell, Rutger and Hörsch, Florian and Moore, Benjamin},
issn = {0012-365X},
journal = {Discrete Mathematics},
number = {6},
publisher = {Elsevier},
title = {{Decompositions into two linear forests of bounded lengths}},
doi = {10.1016/j.disc.2024.113962},
volume = {347},
year = {2024},
}