TY - JOUR AB - We demonstrate the failure of the adiabatic Born-Oppenheimer approximation to describe the ground state of a quantum impurity within an ultracold Fermi gas despite substantial mass differences between the bath and impurity species. Increasing repulsion leads to the appearance of nonadiabatic couplings between the fast bath and slow impurity degrees of freedom, which reduce the parity symmetry of the latter according to the pseudo Jahn-Teller effect. The presence of this mechanism is associated to a conical intersection involving the impurity position and the inverse of the interaction strength, which acts as a synthetic dimension. We elucidate the presence of these effects via a detailed ground-state analysis involving the comparison of ab initio fully correlated simulations with effective models. Our study suggests ultracold atomic ensembles as potent emulators of complex molecular phenomena. AU - Becker, A. AU - Koutentakis, Georgios AU - Schmelcher, P. ID - 15181 IS - 1 JF - Physical Review Research SN - 2643-1564 TI - Synthetic dimension-induced pseudo Jahn-Teller effect in one-dimensional confined fermions VL - 6 ER - TY - JOUR AB - Thermoelectric materials convert heat into electricity, with a broad range of applications near room temperature (RT). However, the library of RT high-performance materials is limited. Traditional high-temperature synthetic methods constrain the range of materials achievable, hindering the ability to surpass crystal structure limitations and engineer defects. Here, a solution-based synthetic approach is introduced, enabling RT synthesis of powders and exploration of densification at lower temperatures to influence the material's microstructure. The approach is exemplified by Ag2Se, an n-type alternative to bismuth telluride. It is demonstrated that the concentration of Ag interstitials, grain boundaries, and dislocations are directly correlated to the sintering temperature, and achieve a figure of merit of 1.1 from RT to 100 °C after optimization. Moreover, insights into and resolve Ag2Se's challenges are provided, including stoichiometry issues leading to irreproducible performances. This work highlights the potential of RT solution synthesis in expanding the repertoire of high-performance thermoelectric materials for practical applications. AU - Kleinhanns, Tobias AU - Milillo, Francesco AU - Calcabrini, Mariano AU - Fiedler, Christine AU - Horta, Sharona AU - Balazs, Daniel AU - Strumolo, Marissa J. AU - Hasler, Roger AU - Llorca, Jordi AU - Tkadletz, Michael AU - Brutchey, Richard L. AU - Ibáñez, Maria ID - 15182 JF - Advanced Energy Materials SN - 1614-6832 TI - A route to high thermoelectric performance: Solution‐based control of microstructure and composition in Ag2Se ER - TY - JOUR AB - Current knowledge suggests a drought Indian monsoon (perhaps a severe one) when the El Nino Southern Oscillation and Pacific Decadal Oscillation each exhibit positive phases (a joint positive phase). For the monsoons, which are exceptions in this regard, we found northeast India often gets excess pre-monsoon rainfall. Further investigation reveals that this excess pre-monsoon rainfall is produced by the interaction of the large-scale circulation associated with the joint phase with the mountains in northeast India. We posit that a warmer troposphere, a consequence of excess rainfall over northeast India, drives a stronger monsoon circulation and enhances monsoon rainfall over central India. Hence, we argue that pre-monsoon rainfall over northeast India can be used for seasonal monsoon rainfall prediction over central India. Most importantly, its predictive value is at its peak when the Pacific Ocean exhibits a joint positive phase and the threat of extreme drought monsoon looms over India. AU - Goswami, Bidyut B ID - 15165 IS - 5 JF - Geophysical Research Letters SN - 0094-8276 TI - A pre-monsoon signal of false alarms of Indian monsoon droughts VL - 51 ER - TY - JOUR AB - 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. AU - Zens, Bettina AU - Fäßler, Florian AU - Hansen, Jesse AU - Hauschild, Robert AU - Datler, Julia AU - Hodirnau, Victor-Valentin AU - Zheden, Vanessa AU - Alanko, Jonna H AU - Sixt, Michael K AU - Schur, Florian KM ID - 15146 IS - 6 JF - Journal of Cell Biology SN - 0021-9525 TI - Lift-out cryo-FIBSEM and cryo-ET reveal the ultrastructural landscape of extracellular matrix VL - 223 ER - TY - JOUR AB - We prove an upper bound on the ground state energy of the dilute spin-polarized Fermi gas capturing the leading correction to the kinetic energy resulting from repulsive interactions. One of the main ingredients in the proof is a rigorous implementation of the fermionic cluster expansion of Gaudin et al. (1971) [15]. AU - Lauritsen, Asbjørn Bækgaard AU - Seiringer, Robert ID - 14931 IS - 7 JF - Journal of Functional Analysis SN - 0022-1236 TI - Ground state energy of the dilute spin-polarized Fermi gas: Upper bound via cluster expansion VL - 286 ER - TY - CHAP AB - The mammary gland consists of a bilayered epithelial structure with an extensively branched morphology. The majority of this epithelial tree is laid down during puberty, during which actively proliferating terminal end buds repeatedly elongate and bifurcate to form the basic structure of the ductal tree. Mammary ducts consist of a basal and luminal cell layer with a multitude of identified sub-lineages within both layers. The understanding of how these different cell lineages are cooperatively driving branching morphogenesis is a problem of crossing multiple scales, as this requires information on the macroscopic branched structure of the gland, as well as data on single-cell dynamics driving the morphogenic program. Here we describe a method to combine genetic lineage tracing with whole-gland branching analysis. Quantitative data on the global organ structure can be used to derive a model for mammary gland branching morphogenesis and provide a backbone on which the dynamics of individual cell lineages can be simulated and compared to lineage-tracing approaches. Eventually, these quantitative models and experiments allow to understand the couplings between the macroscopic shape of the mammary gland and the underlying single-cell dynamics driving branching morphogenesis. AU - Hannezo, Edouard B AU - Scheele, Colinda L.G.J. ED - Margadant, Coert ID - 12428 SN - 9781071628867 T2 - Cell Migration in Three Dimensions TI - A Guide Toward Multi-scale and Quantitative Branching Analysis in the Mammary Gland VL - 2608 ER - TY - JOUR AB - Brownian motion of a mobile impurity in a bath is affected by spin-orbit coupling (SOC). Here, we discuss a Caldeira-Leggett-type model that can be used to propose and interpret quantum simulators of this problem in cold Bose gases. First, we derive a master equation that describes the model and explore it in a one-dimensional (1D) setting. To validate the standard assumptions needed for our derivation, we analyze available experimental data without SOC; as a byproduct, this analysis suggests that the quench dynamics of the impurity is beyond the 1D Bose-polaron approach at temperatures currently accessible in a cold-atom laboratory—motion of the impurity is mainly driven by dissipation. For systems with SOC, we demonstrate that 1D spin-orbit coupling can be gauged out even in the presence of dissipation—the information about SOC is incorporated in the initial conditions. Observables sensitive to this information (such as spin densities) can be used to study formation of steady spin polarization domains during quench dynamics. AU - Ghazaryan, Areg AU - Cappellaro, Alberto AU - Lemeshko, Mikhail AU - Volosniev, Artem ID - 12534 IS - 1 JF - Physical Review Research SN - 2643-1564 TI - Dissipative dynamics of an impurity with spin-orbit coupling VL - 5 ER - TY - JOUR AB - Post-translational histone modifications modulate chromatin activity to affect gene expression. How chromatin states underlie lineage choice in single cells is relatively unexplored. We develop sort-assisted single-cell chromatin immunocleavage (sortChIC) and map active (H3K4me1 and H3K4me3) and repressive (H3K27me3 and H3K9me3) histone modifications in the mouse bone marrow. During differentiation, hematopoietic stem and progenitor cells (HSPCs) acquire active chromatin states mediated by cell-type-specifying transcription factors, which are unique for each lineage. By contrast, most alterations in repressive marks during differentiation occur independent of the final cell type. Chromatin trajectory analysis shows that lineage choice at the chromatin level occurs at the progenitor stage. Joint profiling of H3K4me1 and H3K9me3 demonstrates that cell types within the myeloid lineage have distinct active chromatin but share similar myeloid-specific heterochromatin states. This implies a hierarchical regulation of chromatin during hematopoiesis: heterochromatin dynamics distinguish differentiation trajectories and lineages, while euchromatin dynamics reflect cell types within lineages. AU - Zeller, Peter AU - Yeung, Jake AU - Viñas Gaza, Helena AU - de Barbanson, Buys Anton AU - Bhardwaj, Vivek AU - Florescu, Maria AU - van der Linden, Reinier AU - van Oudenaarden, Alexander ID - 12158 JF - Nature Genetics KW - Genetics SN - 1061-4036 TI - Single-cell sortChIC identifies hierarchical chromatin dynamics during hematopoiesis VL - 55 ER - TY - CONF AB - Turn-based stochastic games (aka simple stochastic games) are two-player zero-sum games played on directed graphs with probabilistic transitions. The goal of player-max is to maximize the probability to reach a target state against the adversarial player-min. These games lie in NP ∩ coNP and are among the rare combinatorial problems that belong to this complexity class for which the existence of polynomial-time algorithm is a major open question. While randomized sub-exponential time algorithm exists, all known deterministic algorithms require exponential time in the worst-case. An important open question has been whether faster algorithms can be obtained parametrized by the treewidth of the game graph. Even deterministic sub-exponential time algorithm for constant treewidth turn-based stochastic games has remain elusive. In this work our main result is a deterministic algorithm to solve turn-based stochastic games that, given a game with n states, treewidth at most t, and the bit-complexity of the probabilistic transition function log D, has running time O ((tn2 log D)t log n). In particular, our algorithm is quasi-polynomial time for games with constant or poly-logarithmic treewidth. AU - Chatterjee, Krishnendu AU - Meggendorfer, Tobias AU - Saona Urmeneta, Raimundo J AU - Svoboda, Jakub ID - 12676 SN - 9781611977554 T2 - Proceedings of the 2023 Annual ACM-SIAM Symposium on Discrete Algorithms TI - Faster algorithm for turn-based stochastic games with bounded treewidth ER - TY - CONF AB - Asynchronous programming has gained significant popularity over the last decade: support for this programming pattern is available in many popular languages via libraries and native language implementations, typically in the form of coroutines or the async/await construct. Instead of programming via shared memory, this concept assumes implicit synchronization through message passing. The key data structure enabling such communication is the rendezvous channel. Roughly, a rendezvous channel is a blocking queue of size zero, so both send(e) and receive() operations wait for each other, performing a rendezvous when they meet. To optimize the message passing pattern, channels are usually equipped with a fixed-size buffer, so sends do not suspend and put elements into the buffer until its capacity is exceeded. This primitive is known as a buffered channel. This paper presents a fast and scalable algorithm for both rendezvous and buffered channels. Similarly to modern queues, our solution is based on an infinite array with two positional counters for send(e) and receive() operations, leveraging the unconditional Fetch-And-Add instruction to update them. Yet, the algorithm requires non-trivial modifications of this classic pattern, in order to support the full channel semantics, such as buffering and cancellation of waiting requests. We compare the performance of our solution to that of the Kotlin implementation, as well as against other academic proposals, showing up to 9.8× speedup. To showcase its expressiveness and performance, we also integrated the proposed algorithm into the standard Kotlin Coroutines library, replacing the previous channel implementations. AU - Koval, Nikita AU - Alistarh, Dan-Adrian AU - Elizarov, Roman ID - 12735 SN - 9798400700156 T2 - Proceedings of the ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming TI - Fast and scalable channels in Kotlin Coroutines ER -