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Academic circles : the celebratory typography of graduation pamphlets in Finland, 1700-1760
Get PDFThis article examines an extraordinary set of eighteenth-century pamphlets published to celebrate magisterial promotions at the Royal Academy of Turku, a university established in 1640 on the Finnish peninsula. The works are unusual in their deployment of an eye-catching typographical motif. Over a 60-year period encompassing 16 promotion ceremonies, we find 26 booklets upon which graduands’ names appear as part of visually striking radial designs. This circumvents the need to list students in linear fashion, as was the practice elsewhere in Europe. This study challenges the notion that radial typography was adopted in a bid to suggest candidates’ equality of status. Instead, it demonstrates how these ‘academic circles’ structure and advertise intra-institutional student networks and consolidate corporate identity. With up to eight pamphlets per promotion, each work was part of a festive flurry of celebratory print: the design was an integral part of the spectacle and ritual of academic promotion.Peer reviewe
Finite Froude and Rossby number baroclinic vortex pairs
Get PDFWe study the evolution of baroclinically-unstable pairs of opposite-signed vortices in a three-dimensional, continuously-stratified, rotating fluid at finite Froude and Rossby numbers. We explore how ageostophic motions affect the evolution of the vortex pairs, in particular the dynamical asymmetry these motions induce in their evolution. To set the stage, we first consider the quasi-geostrophic limit of vanishingly-small Froude and Rossby numbers, conducting a linear stability analysis of two equal-volume, vertically aligned, equal-and-opposite uniform potential vorticity vortices lying at different depths. We also briefly address their nonlinear evolution. In the quasi-geostrophic limit, there is no dynamical asymmetry: cyclonic and anticyclonic vortices (hereafter “cyclones” and “anticyclones”) are identical apart from their sense of rotation. Next, the evolution of equivalent (in isopycnal coordinates) vortex pairs, at finite Froude and Rossby number is explored. In this case, an cyclone/anticyclone asymmetry arises in the evolution of the vortex pair, due to ageostrophic effects. We show that the anticyclone typically deforms less than the cyclone. Moreover, increasing the Froude and Rossby numbers tends to favour baroclinic instabilities with lower azimuthal wavenumbers. The origin of this asymmetry is traced to two contributing factors. First, the displacement of isopycnals means that two vortices, identical in isopycnal coordinates, enclose different volumes, the anticyclone being larger. Second, ageotrophic effects intensify the anticyclone relative to the cyclone. The combination of the two effects implies that the evolution of the baroclinic pair of vortices is dominated by the anticyclone.Peer reviewe
Advances in approximate Bayesian inference for models in epidemiology
Get PDFFunding: The authors thank the University of St Andrews and the China Scholarship Council for their financial support, which made this research possible.Bayesian inference methods are useful in infectious diseases modeling due to their capability to propagate uncertainty, manage sparse data, incorporate latent structures, and address high-dimensional parameter spaces. However, parameter inference through assimilation of observational data in these models remains challenging. While asymptotically exact Bayesian methods offer theoretical guarantees for accurate inference, they can be computationally demanding and impractical for real-time outbreak analysis. This review synthesizes recent advances in approximate Bayesian inference methods that aim to balance inferential accuracy with scalability. We focus on four prominent families: Approximate Bayesian Computation, Bayesian Synthetic Likelihood, Integrated Nested Laplace Approximation, and Variational Inference. For each method, we evaluate its relevance to epidemiological applications, emphasizing innovations that improve both computational efficiency and inference accuracy. We also offer practical guidance on method selection across a range of modeling scenarios. Finally, we identify hybrid exact approximate inference as a promising frontier that combines methodological rigor with the scalability needed for the response to outbreaks. This review provides epidemiologists with a conceptual framework to navigate the trade-off between statistical accuracy and computational feasibility in contemporary disease modeling.Peer reviewe
A comparison of diving behavior of goose-beaked and dense-beaked whales from tagging studies in multiple ocean basins
Get PDFFunding: This analysis of beaked whale tagging data was funded by NOAA's Pacific Islands Fisheries Science Center. Individual tagging studies were funded by multiple sources: the U.S. National Oceanic and Atmospheric Administration (NOAA Fisheries' Pacific Islands Fisheries Science Center, Southwest Fisheries Science Center, Office of Science and Technology, and Ocean Acoustics Program), the U.S. Navy (Office of Naval Research, Living Marine Resources Program (N45/LMR), Pacific Fleet, Chief of Naval Operations' Environmental Readiness Division, US Fleet Forces Command, and Naval Facilities Engineering Command), the Strategic Environmental Research and Development Program, the Sound and Marine Life Joint Industry Programme of the International Association of Oil and Gas Producers, the Marine Alliance for Science and Technology for Scotland (funded by the Scottish Funding Council), the Dutch Research Council, and the Spanish government via grant CETOCAN funded by MICIU/AEI/ 10.13039/501100011033 and FEDER, UE.Studies of cetacean diving behavior in multiple locations in different ocean basins allow for an assessment of variability within and among populations. We examine foraging dive behaviors of goose-beaked whales (Ziphius cavirostris) and dense-beaked whales (Mesoplodon densirostris) using data from 132 tagged whales in seven locations in the Pacific and Atlantic Oceans and the Mediterranean Sea. Acoustic recording tags are used to identify foraging dives by the presence of echolocation. For other tag types, foraging dives are identified based on maximum dive depth. Five parameters are used to characterize foraging dives: maximum dive depth, foraging dive duration, dive cycle duration, and the mean and standard deviation of echolocation depths. We find that differences among dives within one tagged individual are typically larger than the differences among individuals or among locations, and that differences among individuals are typically similar in magnitude to differences among locations. Regression is used to estimate the mean and standard deviation of echolocation depths from maximum dive depth for dives without acoustic data. Composite values of foraging dive parameters (and standard deviations) are estimated as the average of all study locations.Peer reviewe
Induced superconducting correlations in a quantum anomalous Hall insulator
Get PDFFunding: This project has received funding from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 741121) and was also funded by the German Research Foundation under Germany’s Excellence Strategy – Cluster of Excellence Matter and Light for Quantum Computing EXC 2004/1 (Project No. 390534769) and by the German Research Foundation under CRC 1238 Subprojects A04 and B01 (Project No. 277146847). G.L. acknowledges support from KU Leuven’s special research fund and the Research Foundation – Flanders, Belgium (File Nos. 27531 and 52751). K.M. acknowledges support from the Bavarian Ministry of Economic Affairs, Regional Development and Energy within Bavaria’s High-Tech Agenda Project ‘Bausteine für das Quantencomputing auf Basis topologischer Materialien mit experimentellen und theoretischen Ansätzen’ (Grant Allocation No. 07 02/686 58/1/21 1/22 2/23), the QuantERA grant MAGMA and the German Research Foundation (Grant No. 491798118). H.F.L. acknowledges support from the Georg H. Endress Foundation.Thin films of ferromagnetic topological insulator materials can host the quantum anomalous Hall effect without the need for an external magnetic field. Inducing Cooper pairing in such a material is a promising way to realize topological superconductivity with the associated chiral Majorana edge states. However, finding evidence of the superconducting proximity effect in such a state has remained a considerable challenge due to inherent experimental difficulties. Here we demonstrate crossed Andreev reflection across a narrow superconducting Nb electrode that is in contact with the chiral edge state of a quantum anomalous Hall insulator. In the crossed Andreev reflection process, an electron injected from one terminal is reflected out as a hole at the other terminal to form a Cooper pair in the superconductor. This is a compelling signature of induced superconducting pair correlation in the chiral edge state. The characteristic length of the crossed Andreev reflection process is found to be much longer than the superconducting coherence length in Nb, which suggests that the crossed Andreev reflection is, indeed, mediated by superconductivity induced on the quantum anomalous Hall insulator surface. Our results will invite future studies of topological superconductivity and Majorana physics, as well as for the search for non-abelian zero modes.Peer reviewe
Tunable superconducting diode effect in a topological nano-SQUID
Get PDFFunding: This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 741121) and was also funded by the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation) under Germany’s Excellence Strategy - Cluster of Excellence Matter and Light for Quantum Computing (ML4Q) EXC 2004/1 - 390534769, as well as by the DFG under CRC 1238 - 277146847 (subprojects A04 and B01). E.N. acknowledges support by the Studienstiftung des deutschen Volkes. This work was completed in part with resources provided by the Research Computing Data Core at the University of Houston. M.G. acknowledges support from the German Research Foundation under the Walter Benjamin program (grant agreement no. 526129603). L.F. is partly supported by a Simons Investigator Award from the Simons Foundation.A Josephson diode passes current with zero resistance in one direction but is resistive in the other direction. While such an effect has been observed in several platforms, a large and tunable Josephson diode effect has been rare. Here, we report that a simple device consisting of a topological-insulator (TI) nanowire side-contacted by superconductors to form a lateral Josephson junction presents a large diode effect with the efficiency η reaching 0.3 when a parallel magnetic field B|| is applied. The sign and the magnitude of η are tunable not only by B|| but also by the back-gate voltage. This diode effect can be understood by modeling the system as a nano–superconducting quantum interference device (SQUID), in which the top and bottom surfaces of the TI nanowire each form a line junction and B|| creates a magnetic flux to thread the SQUID loop. This model further shows that the observed diode effect marks the emergence of topological superconductivity in TI nanowire–based Josephson junction.Peer reviewe
The formation of glacier dirt cones
Get PDFFunding: This work was funded by a 2020 Geological Society of America Graduate Student Research Grant.Glacier dirt cones are meter-scale cones of ice covered with sediment and rock. The cones develop through a process known as differential melt, whereby ice underlying thick debris melts more slowly than bare ice. We report observations of dirt cones on the Kuskulana Glacier, Alaska and develop a model that simulates the growth of dirt cones from debris-filled pits in the ice. With this model, we vary ice melt rates, hillslope debris diffusion rates and pit geometry. Cone heights scale with the square root of debris volume and growth occurs in three distinct stages: emergence, flux-controlled growth and melt-controlled growth. Using dimensional analysis, we derive a characteristic length composed of the ratio of the debris diffusion rate (D) and the bare ice melt rate (b0). Shorter characteristic lengths produce taller, steeper cones. The characteristic length (ℓ = D/b0) determines, in part, the relative duration of each growth stage because it controls debris flux as relief increases. These experiments suggest increasing melt rates and low-mobility debris increase relief on hummocky debris-covered glaciers. Furthermore, the modeling approach demonstrates a method for handling debris transport over an irregular ice surface and could serve as a component in more comprehensive debris-covered glacier models.Peer reviewe
Large language models surpass human experts in predicting neuroscience results
Get PDFFunding: This work was supported the ESRC (ES/W007347/1), Microsoft (Accelerate Foundation Models Research Program) and a Royal Society Wolfson Fellowship (18302) to B.C.L.Scientific discoveries often hinge on synthesizing decades of research, a task that potentially outstrips human information processing capacities. Large language models (LLMs) offer a solution. LLMs trained on the vast scientific literature could potentially integrate noisy yet interrelated findings to forecast novel results better than human experts. Here, to evaluate this possibility, we created BrainBench, a forward-looking benchmark for predicting neuroscience results. We find that LLMs surpass experts in predicting experimental outcomes. BrainGPT, an LLM we tuned on the neuroscience literature, performed better yet. Like human experts, when LLMs indicated high confidence in their predictions, their responses were more likely to be correct, which presages a future where LLMs assist humans in making discoveries. Our approach is not neuroscience specific and is transferable to other knowledge-intensive endeavours.Peer reviewe
OGLE-2011-BLG-0462 : an isolated stellar-mass black hole confirmed using new HST astrometry and updated photometry
Get PDFThe long-duration Galactic-bulge microlensing event OGLE-2011-BLG-0462 produced relativistic astrometric deflections of the source star, which we measured using Hubble Space Telescope (HST) observations taken at eight epochs over ∼6 yr. Analysis of the microlensing light curve and astrometry led our group (followed by other independent groups) to conclude that the lens is an isolated stellar-mass black hole (BH)—the first and only one unambiguously discovered to date. There have now been three additional epochs of HST observations, increasing the astrometric time baseline to 11 yr. Additionally, the ground-based OGLE data have been updated. We have reanalyzed the data, including the new HST astrometry, and photometry obtained with 16 different telescopes. The source lies only 0.̋4 from a bright neighbor, making it crucial to perform precise subtraction of its point-spread function (PSF) in the astrometric measurements of the source. Moreover, we show that it is essential to perform a separate PSF subtraction for each individual HST frame as part of the reductions. Our final solution yields a lens mass of 7.15 ± 0.83 M⊙. Combined with the lack of detected light from the lens at late HST epochs, the BH nature of the lens is conclusively verified. The BH lies at a distance of 1.52 ± 0.15 kpc, and it is moving with a space velocity of 51.1 ± 7.5 km s−1 relative to the stars in the neighborhood. We compare our results with those of other studies and discuss reasons for the differences. We also searched for binary companions of the BH at a range of separations, but found no evidence for any.Peer reviewe
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