@unpublished{10821, abstract = {Rhythmical cortical activity has long been recognized as a pillar in the architecture of brain functions. Yet, the dynamic organization of its underlying neuronal population activity remains elusive. Here we uncover a unique organizational principle regulating collective neural dynamics associated with the alpha rhythm in the awake resting-state. We demonstrate that cascades of neural activity obey attenuation-amplification dynamics (AAD), with a transition from the attenuation regime—within alpha cycles—to the amplification regime—across a few alpha cycles—that correlates with the characteristic frequency of the alpha rhythm. We find that this short-term AAD is part of a large-scale, size-dependent temporal structure of neural cascades that obeys the Omori law: Following large cascades, smaller cascades occur at a rate that decays as a power-law of the time elapsed from such events—a long-term AAD regulating brain activity over the timescale of seconds. We show that such an organization corresponds to the "waxing and waning" of the alpha rhythm. Importantly, we observe that short- and long-term AAD are unique to the awake resting-state, being absent during NREM sleep. These results provide a quantitative, dynamical description of the so-far-qualitative notion of the "waxing and waning" phenomenon, and suggest the AAD as a key principle governing resting-state dynamics across timescales.}, author = {Lombardi, Fabrizio and Herrmann, Hans J. and Parrino, Liborio and Plenz, Dietmar and Scarpetta, Silvia and Vaudano, Anna Elisabetta and de Arcangelis, Lucilla and Shriki, Oren}, booktitle = {bioRxiv}, pages = {25}, title = {{Alpha rhythm induces attenuation-amplification dynamics in neural activity cascades}}, doi = {10.1101/2022.03.03.482657}, year = {2022}, } @inproceedings{12894, author = {Schlögl, Alois and Hornoiu, Andrei and Elefante, Stefano and Stadlbauer, Stephan}, booktitle = {ASHPC22 - Austrian-Slovenian HPC Meeting 2022}, isbn = {978-3-200-08499-5}, location = {Grundlsee, Austria}, pages = {7}, publisher = {EuroCC Austria}, title = {{Where is the sweet spot? A procurement story of general purpose compute nodes}}, doi = {10.25365/phaidra.337}, year = {2022}, } @inproceedings{17062, author = {Ibáñez, Maria and Liu, Yu and Calcabrini, Mariano}, booktitle = {Proceedings of the nanoGe Spring Meeting 2022}, location = {Spain/Virtual}, publisher = {Fundació de la comunitat valenciana SCITO}, title = {{The importance of surface adsorbates in solution-processed thermoelectric materials}}, doi = {10.29363/nanoge.nsm.2022.159}, year = {2022}, } @article{9469, abstract = {In this paper, we consider reflected three-operator splitting methods for monotone inclusion problems in real Hilbert spaces. To do this, we first obtain weak convergence analysis and nonasymptotic O(1/n) convergence rate of the reflected Krasnosel'skiĭ-Mann iteration for finding a fixed point of nonexpansive mapping in real Hilbert spaces under some seemingly easy to implement conditions on the iterative parameters. We then apply our results to three-operator splitting for the monotone inclusion problem and consequently obtain the corresponding convergence analysis. Furthermore, we derive reflected primal-dual algorithms for highly structured monotone inclusion problems. Some numerical implementations are drawn from splitting methods to support the theoretical analysis.}, author = {Iyiola, Olaniyi S. and Enyi, Cyril D. and Shehu, Yekini}, issn = {1029-4937}, journal = {Optimization Methods and Software}, number = {4}, pages = {1527--1565}, publisher = {Taylor & Francis}, title = {{Reflected three-operator splitting method for monotone inclusion problem}}, doi = {10.1080/10556788.2021.1924715}, volume = {37}, year = {2022}, } @article{9365, abstract = {In this paper, we propose a new iterative method with alternated inertial step for solving split common null point problem in real Hilbert spaces. We obtain weak convergence of the proposed iterative algorithm. Furthermore, we introduce the notion of bounded linear regularity property for the split common null point problem and obtain the linear convergence property for the new algorithm under some mild assumptions. Finally, we provide some numerical examples to demonstrate the performance and efficiency of the proposed method.}, author = {Ogbuisi, Ferdinard U. and Shehu, Yekini and Yao, Jen Chih}, issn = {1029-4945}, journal = {Optimization}, number = {13}, pages = {3767--3795}, publisher = {Taylor & Francis}, title = {{Convergence analysis of new inertial method for the split common null point problem}}, doi = {10.1080/02331934.2021.1914035}, volume = {71}, year = {2022}, } @inproceedings{12536, abstract = {We consider the problem of estimating a rank-1 signal corrupted by structured rotationally invariant noise, and address the following question: how well do inference algorithms perform when the noise statistics is unknown and hence Gaussian noise is assumed? While the matched Bayes-optimal setting with unstructured noise is well understood, the analysis of this mismatched problem is only at its premises. In this paper, we make a step towards understanding the effect of the strong source of mismatch which is the noise statistics. Our main technical contribution is the rigorous analysis of a Bayes estimator and of an approximate message passing (AMP) algorithm, both of which incorrectly assume a Gaussian setup. The first result exploits the theory of spherical integrals and of low-rank matrix perturbations; the idea behind the second one is to design and analyze an artificial AMP which, by taking advantage of the flexibility in the denoisers, is able to "correct" the mismatch. Armed with these sharp asymptotic characterizations, we unveil a rich and often unexpected phenomenology. For example, despite AMP is in principle designed to efficiently compute the Bayes estimator, the former is outperformed by the latter in terms of mean-square error. We show that this performance gap is due to an incorrect estimation of the signal norm. In fact, when the SNR is large enough, the overlaps of the AMP and the Bayes estimator coincide, and they even match those of optimal estimators taking into account the structure of the noise.}, author = {Barbier, Jean and Hou, TianQi and Mondelli, Marco and Saenz, Manuel}, booktitle = {36th Conference on Neural Information Processing Systems}, isbn = {9781713871088}, issn = {1049-5258}, location = {New Orleans, LA, United States}, publisher = {Neural Information Processing Systems Foundation}, title = {{The price of ignorance: How much does it cost to forget noise structure in low-rank matrix estimation?}}, volume = {35}, year = {2022}, } @inproceedings{12775, abstract = {We consider the problem of approximating the reachability probabilities in Markov decision processes (MDP) with uncountable (continuous) state and action spaces. While there are algorithms that, for special classes of such MDP, provide a sequence of approximations converging to the true value in the limit, our aim is to obtain an algorithm with guarantees on the precision of the approximation. As this problem is undecidable in general, assumptions on the MDP are necessary. Our main contribution is to identify sufficient assumptions that are as weak as possible, thus approaching the "boundary" of which systems can be correctly and reliably analyzed. To this end, we also argue why each of our assumptions is necessary for algorithms based on processing finitely many observations. We present two solution variants. The first one provides converging lower bounds under weaker assumptions than typical ones from previous works concerned with guarantees. The second one then utilizes stronger assumptions to additionally provide converging upper bounds. Altogether, we obtain an anytime algorithm, i.e. yielding a sequence of approximants with known and iteratively improving precision, converging to the true value in the limit. Besides, due to the generality of our assumptions, our algorithms are very general templates, readily allowing for various heuristics from literature in contrast to, e.g., a specific discretization algorithm. Our theoretical contribution thus paves the way for future practical improvements without sacrificing correctness guarantees.}, author = {Grover, Kush and Kretinsky, Jan and Meggendorfer, Tobias and Weininger, Maimilian}, booktitle = {33rd International Conference on Concurrency Theory}, issn = {1868-8969}, location = {Warsaw, Poland}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{Anytime guarantees for reachability in uncountable Markov decision processes}}, doi = {10.4230/LIPIcs.CONCUR.2022.11}, volume = {243}, year = {2022}, } @inproceedings{12508, abstract = {We explore the notion of history-determinism in the context of timed automata (TA). History-deterministic automata are those in which nondeterminism can be resolved on the fly, based on the run constructed thus far. History-determinism is a robust property that admits different game-based characterisations, and history-deterministic specifications allow for game-based verification without an expensive determinization step. We show yet another characterisation of history-determinism in terms of fair simulation, at the general level of labelled transition systems: a system is history-deterministic precisely if and only if it fairly simulates all language smaller systems. For timed automata over infinite timed words it is known that universality is undecidable for Büchi TA. We show that for history-deterministic TA with arbitrary parity acceptance, timed universality, inclusion, and synthesis all remain decidable and are ExpTime-complete. For the subclass of TA with safety or reachability acceptance, we show that checking whether such an automaton is history-deterministic is decidable (in ExpTime), and history-deterministic TA with safety acceptance are effectively determinizable without introducing new automata states.}, author = {Henzinger, Thomas A and Lehtinen, Karoliina and Totzke, Patrick}, booktitle = {33rd International Conference on Concurrency Theory}, isbn = {9783959772464}, issn = {1868-8969}, location = {Warsaw, Poland}, pages = {14:1--14:21}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik}, title = {{History-deterministic timed automata}}, doi = {10.4230/LIPIcs.CONCUR.2022.14}, volume = {243}, year = {2022}, } @article{12236, abstract = {High-entropy materials offer numerous advantages as catalysts, including a flexible composition to tune the catalytic activity and selectivity and a large variety of adsorption/reaction sites for multistep or multiple reactions. Herein, we report on the synthesis, properties, and electrocatalytic performance of an amorphous high-entropy boride based on abundant transition metals, CoFeNiMnZnB. This metal boride provides excellent performance toward the oxygen evolution reaction (OER), including a low overpotential of 261 mV at 10 mA cm–2, a reduced Tafel slope of 56.8 mV dec–1, and very high stability. The outstanding OER performance of CoFeNiMnZnB is attributed to the synergistic interactions between the different metals, the leaching of Zn ions, the generation of oxygen vacancies, and the in situ formation of an amorphous oxyhydroxide at the CoFeNiMnZnB surface during the OER.}, author = {Wang, Xiang and Zuo, Yong and Horta, Sharona and He, Ren and Yang, Linlin and Ostovari Moghaddam, Ahmad and Ibáñez, Maria and Qi, Xueqiang and Cabot, Andreu}, issn = {1944-8252}, journal = {ACS Applied Materials and Interfaces}, keywords = {General Materials Science}, number = {42}, pages = {48212--48219}, publisher = {American Chemical Society}, title = {{CoFeNiMnZnB as a high-entropy metal boride to boost the oxygen evolution reaction}}, doi = {10.1021/acsami.2c11627}, volume = {14}, year = {2022}, } @article{17076, abstract = {Introduction: The levels of many blood proteins are associated with Alzheimer's disease (AD) or its pathological hallmarks. Elucidating the molecular factors that control circulating levels of these proteins may help to identify proteins associated with disease risk mechanisms. Methods: Genome-wide and epigenome-wide studies (nindividuals ≤1064) were performed on plasma levels of 282 AD-associated proteins, identified by a structured literature review. Bayesian penalized regression estimated contributions of genetic and epigenetic variation toward inter-individual differences in plasma protein levels. Mendelian randomization (MR) and co-localization tested associations between proteins and disease-related phenotypes. Results: Sixty-four independent genetic and 26 epigenetic loci were associated with 45 proteins. Novel findings included an association between plasma triggering receptor expressed on myeloid cells 2 (TREM2) levels and a polymorphism and cytosine-phosphate-guanine (CpG) site within the MS4A4A locus. Higher plasma tubulin-specific chaperone A (TBCA) and TREM2 levels were significantly associated with lower AD risk. Discussion: Our data inform the regulation of biomarker levels and their relationships with AD.}, author = {Hillary, Robert F. and Gadd, Danni A. and McCartney, Daniel L. and Shi, Liu and Campbell, Archie and Walker, Rosie M. and Ritchie, Craig W. and Deary, Ian J. and Evans, Kathryn L. and Nevado‐Holgado, Alejo J. and Hayward, Caroline and Porteous, David J. and McIntosh, Andrew M. and Lovestone, Simon and Robinson, Matthew Richard and Marioni, Riccardo E.}, issn = {2352-8729}, journal = {Alzheimer's & Dementia}, number = {1}, publisher = {Wiley}, title = {{Genome‐ and epigenome‐wide studies of plasma protein biomarkers for Alzheimer's disease implicate TBCA and TREM2 in disease risk}}, doi = {10.1002/dad2.12280}, volume = {14}, year = {2022}, } @article{11705, abstract = {The broad implementation of thermoelectricity requires high-performance and low-cost materials. One possibility is employing surfactant-free solution synthesis to produce nanopowders. We propose the strategy of functionalizing “naked” particles’ surface by inorganic molecules to control the nanostructure and, consequently, thermoelectric performance. In particular, we use bismuth thiolates to functionalize surfactant-free SnTe particles’ surfaces. Upon thermal processing, bismuth thiolates decomposition renders SnTe-Bi2S3 nanocomposites with synergistic functions: 1) carrier concentration optimization by Bi doping; 2) Seebeck coefficient enhancement and bipolar effect suppression by energy filtering; and 3) lattice thermal conductivity reduction by small grain domains, grain boundaries and nanostructuration. Overall, the SnTe-Bi2S3 nanocomposites exhibit peak z T up to 1.3 at 873 K and an average z T of ≈0.6 at 300–873 K, which is among the highest reported for solution-processed SnTe.}, author = {Chang, Cheng and Liu, Yu and Lee, Seungho and Spadaro, Maria and Koskela, Kristopher M. and Kleinhanns, Tobias and Costanzo, Tommaso and Arbiol, Jordi and Brutchey, Richard L. and Ibáñez, Maria}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, number = {35}, publisher = {Wiley}, title = {{Surface functionalization of surfactant-free particles: A strategy to tailor the properties of nanocomposites for enhanced thermoelectric performance}}, doi = {10.1002/anie.202207002}, volume = {61}, year = {2022}, } @article{11451, abstract = {The precursor conversion chemistry and surface chemistry of Cu3N and Cu3PdN nanocrystals are unknown or contested. Here, we first obtain phase-pure, colloidally stable nanocubes. Second, we elucidate the pathway by which copper(II) nitrate and oleylamine form Cu3N. We find that oleylamine is both a reductant and a nitrogen source. Oleylamine is oxidized by nitrate to a primary aldimine, which reacts further with excess oleylamine to a secondary aldimine, eliminating ammonia. Ammonia reacts with CuI to form Cu3N. Third, we investigated the surface chemistry and find a mixed ligand shell of aliphatic amines and carboxylates (formed in situ). While the carboxylates appear tightly bound, the amines are easily desorbed from the surface. Finally, we show that doping with palladium decreases the band gap and the material becomes semi-metallic. These results bring insight into the chemistry of metal nitrides and might help the development of other metal nitride nanocrystals.}, author = {Parvizian, Mahsa and Duràn Balsa, Alejandra and Pokratath, Rohan and Kalha, Curran and Lee, Seungho and Van Den Eynden, Dietger and Ibáñez, Maria and Regoutz, Anna and De Roo, Jonathan}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, number = {31}, publisher = {Wiley}, title = {{The chemistry of Cu₃N and Cu₃PdN nanocrystals}}, doi = {10.1002/anie.202207013}, volume = {61}, year = {2022}, } @misc{11695, abstract = {Data underlying the figures in the publication "The chemistry of Cu3N and Cu3PdN nanocrystals" }, author = {Parvizian, Mahsa and Duran Balsa, Alejandra and Pokratath, Rohan and Kalha, Curran and Lee, Seungho and Van den Eynden, Dietger and Ibáñez, Maria and Regoutz, Anna and De Roo, Jonathan}, publisher = {Zenodo}, title = {{Data for "The chemistry of Cu3N and Cu3PdN nanocrystals"}}, doi = {10.5281/ZENODO.6542908}, year = {2022}, } @article{10652, abstract = {Finding a feasible scheme for testing the quantum mechanical nature of the gravitational interaction has been attracting an increasing level of attention. Gravity mediated entanglement generation so far appears to be the key ingredient for a potential experiment. In a recent proposal [D. Carney et al., PRX Quantum 2, 030330 (2021)] combining an atom interferometer with a low-frequency mechanical oscillator, a coherence revival test is proposed for verifying this entanglement generation. With measurements performed only on the atoms, this protocol bypasses the need for correlation measurements. Here, we explore formulations of such a protocol, and specifically find that in the envisioned regime of operation with high thermal excitation, semiclassical models, where there is no concept of entanglement, also give the same experimental signatures. We elucidate in a fully quantum mechanical calculation that entanglement is not the source of the revivals in the relevant parameter regime. We argue that, in its current form, the suggested test is only relevant if the oscillator is nearly in a pure quantum state, and in this regime the effects are too small to be measurable. We further discuss potential open ends. The results highlight the importance and subtleties of explicitly considering how the quantum case differs from the classical expectations when testing for the quantum mechanical nature of a physical system.}, author = {Hosten, Onur}, issn = {2643-1564}, journal = {Physical Review Research}, number = {1}, publisher = {American Physical Society}, title = {{Constraints on probing quantum coherence to infer gravitational entanglement}}, doi = {10.1103/PhysRevResearch.4.013023}, volume = {4}, year = {2022}, } @article{11438, abstract = {Lasers with well-controlled relative frequencies are indispensable for many applications in science and technology. We present a frequency-offset locking method for lasers based on beat-frequency discrimination utilizing hybrid electronic LC filters. The method is specifically designed for decoupling the tightness of the lock from the broadness of its capture range. The presented demonstration locks two free-running diode lasers at 780 nm with a 5.5-GHz offset. It displays an offset frequency instability below 55 Hz for time scales in excess of 1000 s and a minimum of 12 Hz at 10-s averaging. The performance is complemented with a 190-MHz lock-capture range, a tuning range of up to 1 GHz, and a frequency ramp agility of 200kHz/μs.}, author = {Li, Vyacheslav and Diorico, Fritz R and Hosten, Onur}, issn = {2331-7019}, journal = {Physical Review Applied}, keywords = {General Physics and Astronomy}, number = {5}, publisher = {American Physical Society}, title = {{Laser frequency-offset locking at 10-Hz-level instability using hybrid electronic filters}}, doi = {10.1103/physrevapplied.17.054031}, volume = {17}, year = {2022}, } @article{22160, abstract = {Motivated by higher vanishing multiplicity generalizations of Alon's Combinatorial Nullstellensatz and its applications, we study the following problem: for fixed and large with respect to , what is the minimum possible degree of a polynomial with such that has zeroes of multiplicity at least at all points in ? For , a classical theorem of Alon and Füredi states that the minimum possible degree of such a polynomial equals . In this paper, we solve the problem for all , proving that the answer is . As an application, we improve a result of Clifton and Huang on configurations of hyperplanes in such that each point in is covered by at least hyperplanes, but the point is uncovered. Surprisingly, the proof of our result involves Catalan numbers and arguments from enumerative combinatorics.}, author = {Sauermann, Lisa and Wigderson, Yuval}, issn = {1469-7750}, journal = {Journal of the London Mathematical Society}, number = {3}, pages = {2379--2402}, publisher = {Wiley}, title = {{Polynomials that vanish to high order on most of the hypercube}}, doi = {10.1112/jlms.12637}, volume = {106}, year = {2022}, } @article{12573, abstract = {Supraglacial debris strongly modulates glacier melt rates and can be decisive for ice dynamics and mountain hydrology. It is ubiquitous in High-Mountain Asia, yet because its thickness and supply rate from local topography are poorly known, our ability to forecast regional glacier change and streamflow is limited. Here we combined remote sensing and numerical modelling to resolve supraglacial debris thickness by altitude for 4689 glaciers in High-Mountain Asia, and debris-supply rate to 4141 of those glaciers. Our results reveal extensively thin supraglacial debris and high spatial variability in both debris thickness and supply rate. Debris-supply rate increases with the temperature and slope of debris-supply slopes regionally, and debris thickness increases as ice flow decreases locally. Our centennial-scale estimates of debris-supply rate are typically an order of magnitude or more lower than millennial-scale estimates of headwall-erosion rate from Beryllium-10 cosmogenic nuclides, potentially reflecting episodic debris supply to the region’s glaciers.}, author = {McCarthy, Michael and Miles, Evan and Kneib, Marin and Buri, Pascal and Fugger, Stefan and Pellicciotti, Francesca}, issn = {2662-4435}, journal = {Communications Earth and Environment}, keywords = {General Earth and Planetary Sciences, General Environmental Science}, publisher = {Springer Nature}, title = {{Supraglacial debris thickness and supply rate in High-Mountain Asia}}, doi = {10.1038/s43247-022-00588-2}, volume = {3}, year = {2022}, } @article{22174, abstract = {The book graph B (k) n consists of n copies of Kk+1 joined along a common Kk. The Ramsey numbers of B (k) n are known to have strong connections to the classical Ramsey numbers of cliques. Recently, the first author determined the asymptotic order of these Ramsey numbers for fixed k, thus answering an old question of Erd˝os, Faudree, Rousseau, and Schelp. In this paper, we first provide a simpler proof of this theorem. Next, answering a question of the first author, we present a different proof that avoids the use of Szemer´edi’s regularity lemma, thus providing much tighter control on the error term. Finally, we prove a conjecture of Nikiforov, Rousseau, and Schelp by showing that all extremal colorings for this Ramsey problem are quasirandom}, author = {Conlon, David and Fox, Jacob and Wigderson, Yuval}, issn = {1439-6912}, journal = {Combinatorica}, number = {3}, pages = {309--363}, publisher = {Springer Nature}, title = {{Ramsey numbers of books and quasirandomness}}, doi = {10.1007/s00493-021-4409-9}, volume = {42}, year = {2022}, } @article{22193, abstract = {Gross and Smith have put forward generalizations of Hardy–Littlewood twin prime conjectures for algebraic number fields. We estimate the behaviour of sums of a singular series that arises in these conjectures, up to lower-order terms. More exactly, where S(η) is the singular series, we find asymptotic formulas for smoothed sums of S(η)−1. Based upon Gross and Smith’s conjectures, we use our result to suggest that for large enough ‘short intervals’ in an algebraic number field K, the variance of counts of prime elements in a random short interval deviates from a Cramér model prediction by a universal factor, independent of K. The conjecture over number fields generalizes a classical conjecture of Goldston and Montgomery over the integers. Numerical data are provided supporting the conjecture.}, author = {Kuperberg, Vivian Zieve and Rodgers, Brad and Roditty-Gershon, Edva}, issn = {1572-9303}, journal = {The Ramanujan Journal}, keywords = {Primes, Short intervals, Ramanujan sums, Singular series, Number fields}, number = {2}, pages = {291--317}, publisher = {Springer Nature}, title = {{Sums of singular series and primes in short intervals in algebraic number fields}}, doi = {10.1007/s11139-022-00561-9}, volume = {58}, year = {2022}, } @article{22194, abstract = {In [J. P. Keating, B. Rodgers, E. Roditty-Gershon and Z. Rudnick, Sums of divisor functions in 𝔽𝑞⁢[𝑡] and matrix integrals, Math. Z. 288 2018, 1–2, 167–198], the authors established relationships of the mean-square of sums of the divisor function 𝑑𝑘⁢(𝑓) over short intervals and over arithmetic progressions for the function field 𝔽𝑞⁢[𝑇] to certain integrals over the ensemble of unitary matrices. We consider similar problems leading to distributions over the ensemble of symplectic matrices. We also consider analogous questions involving convolutions of the von Mangoldt function.}, author = {Kuperberg, Vivian Zieve and Lalín, Matilde}, issn = {1435-5337}, journal = {Forum Mathematicum}, number = {3}, pages = {711--747}, publisher = {De Gruyter}, title = {{Sums of divisor functions and von Mangoldt convolutions in 𝔽q[T] leading to symplectic distributions}}, doi = {10.1515/forum-2021-0171}, volume = {34}, year = {2022}, }