cssi/SciSciGPT-SciSciNet huggingface dataset:
Free-water metrics in medial temporal lobe white matter tract projections relate to longitudinal cognitive decline.

Abstract Although hippocampal volume has served as a long-standing predictor of cognitive decline, diffusion magnetic resonance imaging studies of white matter have shown similar relationships. Still, it remains unclear if gray matter and white matter interact to predict cognitive impairment and longitudinal decline. Here, we investigate whether free-water (FW) and FW-corrected fractional anisotropy (FAT) within medial temporal lobe white matter tracts provides meaningful contribution to cognition and cognitive decline beyond hippocampal volume. Using data from the Vanderbilt Memory & Aging Project (n = 319), we found that FW was associated with baseline memory and executive function beyond that of hippocampal volume and other comorbidities. Longitudinal analyses demonstrated significant interactions of hippocampal volume and inferior longitudinal fasciculus (p = 0.043) and cingulum bundle (p = 0.025) FAT on memory decline and with fornix FAT (p = 0.025) on decline in executive function. Results suggest that FW metrics of white matter have a unique role in cognitive decline and should be included in theoretical models of aging, cerebrovascular disease, and Alzheimer’s disease.
Comparative analysis of authorship trends in the Journal of Hand Surgery European and American volumes: A bibliometric analysis.

Abstract Background The purpose of this study was to better understand the authorship publishing trends in the field of hand surgery. To accomplish this, a comparative analysis was completed between the European and American volumes of the Journal of Hand Surgery (JHSE and JHSA) over the past three decades. Well-established bibliometric methods were used to examine one representative year from each of the past three decades. The focus of the study was to examine changes in author gender over time as well as to compare authorship trends across the two volumes. Materials and methods All JHSA and JHSE publications from 1985, 1995, 2005, and 2015 were placed into a Microsoft Excel spreadsheet. Data was collected for each publication including the gender of first and corresponding authors, corresponding author position, corresponding author country of origin, number of credited institutions, authors, printed pages, and references. Countries were grouped by regions. Results A total of 450 and 763 manuscripts from JHSE and JHSA, respectively, met inclusion criteria. JHSE and JHSA both showed increases in most variables analyzed over time. Both journals showed an increase in female first and corresponding authors. JHSE and JHSA displayed a rise in collaboration between institutions and countries. Conclusions Both JHSE and JHSA display increasing female inclusion in the hand surgery literature, which has traditionally been a male dominated field. The observed increase in collaboration between institutions and countries is likely linked to advances in technology that allow sharing of information more conveniently and reliably than was previously possible. As further advances are made socially and technologically, hopefully these trends will continue, leading to faster and higher quality research being generated in the field of hand surgery.
On the Identifiability of the Influence Model for Stochastic Spatiotemporal Spread Processes

The influence model is a discrete-time stochastic model that succinctly captures the interactions of a network of interacting Markov chains. The model produces a reduced-order representation of stochastic networks, and can be used to describe and tractably analyze probabilistic spatiotemporal spread dynamics, and hence has found broad usage in network applications, such as social networks, traffic management, and failure cascades in power systems. This article provides sufficient and necessary conditions for the identifiability of the influence model, and also develops estimators for model structures through exploiting the model’s special properties. In addition, we analyze conditions for the identifiability of the partially observed influence model (POIM), for which not all of the sites can be measured. We develop an expectation-maximization (EM) algorithm-based estimator for POIMs.
Optical Non-Line-of-Sight Physics-Based 3D Human Pose Estimation

We describe a method for 3D human pose estimation from transient images (i.e., a 3D spatio-temporal histogram of photons) acquired by an optical non-line-of-sight (NLOS) imaging system. Our method can perceive 3D human pose by 'looking around corners' through the use of light indirectly reflected by the environment. We bring together a diverse set of technologies from NLOS imaging, human pose estimation and deep reinforcement learning to construct an end-to-end data processing pipeline that converts a raw stream of photon measurements into a full 3D human pose sequence estimate. Our contributions are the design of data representation process which includes (1) a learnable inverse point spread function (PSF) to convert raw transient images into a deep feature vector; (2) a neural humanoid control policy conditioned on the transient image feature and learned from interactions with a physics simulator; and (3) a data synthesis and augmentation strategy based on depth data that can be transferred to a real-world NLOS imaging system. Our preliminary experiments suggest that our method is able to generalize to real-world NLOS measurement to estimate physically-valid 3D human poses.
Mortgage market credit conditions and U.S. Presidential elections

Abstract Voters punish incumbent Presidential candidates for contractions in the county-level supply of mortgage credit during market-wide contractions of credit, but do not reward them for expansions in mortgage credit supply in boom times. Our primary focus is the Presidential election of 2008, which followed an unprecedented swing from very generous mortgage underwriting standards to a severe contraction of mortgage credit. Voters responded to the credit crunch by shifting their support away from the Republican Presidential candidate in 2008. That shift was large and particularly pronounced in states that typically vote Republican, and in swing states. Without it McCain would have received half the votes needed in nine crucial swing states to reverse the outcome of the election. We extend our analysis to the Presidential elections from 1996 to 2012 and find that voters only react to contractions, not expansions, of credit, and reactions are similar for Democratic and Republican incumbent parties.
Generation of Heart Organoids Modeling Early Human Cardiac Development Under Defined Conditions

Abstract Cardiovascular-related disorders are a significant worldwide health problem. Cardiovascular disease (CVD) is the leading cause of death in developed countries, making up a third of the mortality rate in the US1. Congenital heart defects (CHD) affect ∼1% of all live births2, making it the most common birth defect in humans. Current technologies provide some insight into how these disorders originate but are limited in their ability to provide a complete overview of disease pathogenesis and progression due to their lack of physiological complexity. There is a pressing need to develop more faithful organ-like platforms recapitulating complex in vivo phenotypes to study human development and disease in vitro. Here, we report the most faithful in vitro organoid model of human cardiovascular development to date using human pluripotent stem cells (hPSCs). Our protocol is highly efficient, scalable, shows high reproducibility and is compatible with high-throughput approaches. Furthermore, our hPSC-based heart organoids (hHOs) showed very high similarity to human fetal hearts, both morphologically and in cell-type complexity. hHOs were differentiated using a two-step manipulation of Wnt signaling using chemical inhibitors and growth factors in completely defined media and culture conditions. Organoids were successfully derived from multiple independent hPSCs lines with very similar efficiency. hHOs started beating at ∼6 days, were mostly spherical and grew up to ∼1 mm in diameter by day 15 of differentiation. hHOs developed sophisticated, interconnected internal chambers and confocal analysis for cardiac markers revealed the presence of all major cardiac lineages, including cardiomyocytes (TNNT2+), epicardial cells (WT1+, TJP+), cardiac fibroblasts (THY1+, VIM+), endothelial cells (PECAM1+), and endocardial cells (NFATC1+). Morphologically, hHOs developed well-defined epicardial and adjacent myocardial regions and presented a distinct vascular plexus as well as endocardial-lined microchambers. RNA-seq time-course analysis of hHOs, monolayer differentiated iPSCs and fetal human hearts revealed that hHOs recapitulate human fetal heart tissue development better than previously described differentiation protocols3,4. hHOs allow higher-order interaction of distinct heart tissues for the first time and display biologically relevant physical and topographical 3D cues that closely resemble the human fetal heart. Our model constitutes a powerful novel tool for discovery and translational studies in human cardiac development and disease.
Novel color center platforms enabling fundamental scientific discovery

Color centers are versatile systems that generate quantum light, sense magnetic fields and produce spin-photon entanglement. We review how these properties have pushed the limits of fundamental knowledge in a variety of scientific disciplines, from rejecting local-realistic theories to sensing superconducting phase transitions. In the light of recent progress in material processing and device fabrication, we identify new opportunities for interdisciplinary fundamental discoveries in physics and geochemistry.
Cosmetic two-strand twists on fibered knots

Let $K$ be a knot in a rational homology sphere $M$. This paper investigates the question of when modifying $K$ by adding $m>0$ half-twists to two oppositely-oriented strands, while keeping the rest of $K$ fixed, produces a knot isotopic to $K$. Such a two-strand twist of order $m$, as we define it, is a generalized crossing change when $m$ is even and a non-coherent band surgery when $m=1$. A cosmetic two-strand twist on $K$ is a non-nugatory one that produces an isotopic knot. We prove that fibered knots in $M$ admit no cosmetic generalized crossing changes. Further, we show that if $K$ is fibered, then a two-strand twist of odd order $m$ that is determined by a separating arc in a fiber surface for $K$ can only be cosmetic if $m=\pm 1$. After proving these theorems, we further investigate cosmetic two-strand twists of odd orders. Through two examples, we find that the second theorem above becomes false if `separating' is removed, and that a key technical proposition fails when the order equals 1. A closer look at an order-one example, an instance of cosmetic band surgery on the unknot, reveals it to be nearly trivial in a sense that we name `weakly nugatory'. We correct the technical proposition to obtain a means of using double branched covers to show that certain band surgeries are weakly nugatory. As an application, we prove that every cosmetic band surgery on the unknot is of this type.
Individual Cell Fault Detection for Parallel-Connected Battery Cells Based on the Statistical Model and Analysis

Fault diagnosis is extremely important to the safe operation of Lithium-ion batteries. To avoid severe safety issues (e.g., thermal runaway), initial faults should be timely detected and resolved. In this paper, we consider parallel-connected battery cells with only one voltage and one current sensor. The lack of independent current sensors makes it difficult to detect individual cell degradation. To this end, based on the high-frequency response of the battery, a simplified fault detection-oriented model is derived and validated by a physics-informed battery model. The resistance of the battery string, which is significantly influenced by the faulty cell, is estimated and used as the health indicator. The statistical resistance distribution of battery strings is first analyzed considering the distribution of fresh and aged cells. A fault diagnosis algorithm is proposed and the thresholds (i.e., 2 standard deviation interval) are obtained through statistical analysis. Monte Carlo simulation results show that the proposed fault diagnosis algorithm can balance false alarms and missed detections well. In addition, it is verified that the proposed algorithm is robust to the uniform parameter changes of individual battery cells.
Mean Field Game and Decentralized Intelligent Adaptive Pursuit Evasion Strategy for Massive Multi-Agent System under Uncertain Environment

In this paper, a novel decentralized intelligent adaptive optimal strategy has been developed to solve the pursuit-evasion game for massive Multi-Agent Systems (MAS) under uncertain environment. Existing strategies for pursuit-evasion games are neither efficient nor practical for large population multi-agent system due to the notorious "Curse of dimensionality" and communication limit while the agent population is large. To overcome these challenges, the emerging mean field game theory is adopted and further integrated with reinforcement learning to develop a novel decentralized intelligent adaptive strategy with a new type of adaptive dynamic programing architecture named the Actor-Critic-Mass (ACM). Through online approximating the solution of the coupled mean field equations, the developed strategy can obtain the optimal pursuit-evasion policy even for massive MAS under uncertain environment. In the proposed ACM learning based strategy, each agent maintains five neural networks, which are 1) the critic neural network to approximate the solution of the HJI equation for each individual agent; 2) the mass neural network to estimate the population density function (i.e., mass) of the group; 3) the actor neural network to approximate the decentralized optimal strategy, and 4) two more neural networks are designed to estimate the opponents' group mass as well as the optimal cost function. Eventually, a comprehensive numerical simulation has been provided to demonstrate the effectiveness of the designed strategy.
Fish predation on corals promotes the dispersal of coral symbionts

The microbiomes of foundation (habitat-forming) species such as corals and sponges underpin the biodiversity, productivity, and stability of ecosystems. Consumers shape communities of foundation species through trophic interactions, but the role of consumers in dispersing the microbiomes of such species is rarely examined. For example, stony corals rely on a nutritional symbiosis with single-celled endosymbiotic dinoflagellates (family Symbiodiniaceae) to construct reefs. Most corals acquire Symbiodiniaceae from the environment, but the processes that make Symbiodiniaceae available for uptake are not resolved. Here, we provide the first comprehensive, reef-scale demonstration that predation by diverse coral-eating (corallivorous) fish species promotes the dispersal of Symbiodiniaceae, based on symbiont cell densities and community compositions from the feces of four obligate corallivores, three facultative corallivores, two grazer/detritivores as well as samples of reef sediment and water. Obligate corallivore feces are environmental hotspots of Symbiodiniaceae cells: live symbiont cell concentrations in such feces are 5–7 orders of magnitude higher than sediment and water environmental reservoirs. Symbiodiniaceae community compositions in the feces of obligate corallivores are similar to those in two locally abundant coral genera (Pocillopora and Porites), but differ from Symbiodiniaceae communities in the feces of facultative corallivores and grazer/detritivores as well as sediment and water. Combining our data on live Symbiodiniaceae cell densities in feces with in situ observations of fish, we estimate that some obligate corallivorous fish species release over 100 million Symbiodiniaceae cells per 100 m2 of reef per day. Released corallivore feces came in direct contact with coral colonies in the fore reef zone following 91% of observed egestion events, providing a potential mechanism for the transfer of live Symbiodiniaceae cells among coral colonies. Taken together, our findings show that fish predation on corals may support the maintenance of coral cover on reefs in an unexpected way: through the dispersal of beneficial coral symbionts in corallivore feces. Few studies examine the processes that make symbionts available to foundation species, or how environmental reservoirs of such symbionts are replenished. This work sets the stage for parallel studies of consumer-mediated microbiome dispersal and assembly in other sessile, habitat-forming species.
A Better Bound Gives a Hundred Rounds: Enhanced Privacy Guarantees via f-Divergences

We derive the optimal differential privacy (DP) parameters of a mechanism that satisfies a given level of Renyi´ differential privacy (RDP). Our result is based on the joint range of two f-divergences that underlie the approximate and the Renyi variations of differential privacy. We apply our result to´ the moments accountant framework for characterizing privacy guarantees of stochastic gradient descent. When compared to the state-of-the-art, our bounds may lead to about 100 more stochastic gradient descent iterations for training deep learning models for the same privacy budget.
“Rugged individualism” and collective (In)action during the COVID-19 pandemic

Rugged individualism—the combination of individualism and anti-statism—is a prominent feature of American culture with deep roots in the country’s history of frontier settlement. Today, rugged individualism is more prevalent in counties with greater total frontier experience (TFE) during the era of westward expansion. While individualism may be conducive to innovation, it can also undermine collective action, with potentially adverse social consequences. We show that America’s frontier culture hampered the response to the COVID-19 pandemic. Across U.S. counties, greater TFE is associated with less social distancing and mask use as well as weaker local government effort to control the virus. We argue that frontier culture lies at the root of several more proximate explanations for the weak collective response to public health risks, including a lack of civic duty, partisanship, and distrust in science.
Where are we with light sterile neutrinos

Abstract We review the status of searches for sterile neutrinos in the ∼ 1 eV range, with an emphasis on the latest results from short baseline oscillation experiments and how they fit within sterile neutrino oscillation models. We present global fit results to a three-active-flavor plus one-sterile-flavor model (3+1), where we find an improvement of Δ χ 2 = 35 for 3 additional parameters compared to a model with no sterile neutrino. This is a 5 σ improvement, indicating that an effect that is like that of a sterile neutrino is highly preferred by the data. However we note that separate fits to the appearance and disappearance oscillation data sets within a 3+1 model do not show the expected overlapping allowed regions in parameter space. This “tension” leads us to explore two options: 3+2, where a second additional mass state is introduced, and a 3+1+decay model, where the ν 4 state can decay to invisible particles. The 3+1+decay model, which is also motivated by improving compatibility with cosmological observations, yields the larger improvement, with a Δ χ 2 = 8 for 1 additional parameter beyond the 3+1 model, which is a 2 . 6 σ improvement. Moreover the tension between appearance and disappearance experiments is reduced compared to 3+1, although disagreement remains. In these studies, we use a frequentist approach and also a Bayesian method of finding credible regions. With respect to this tension, we review possible problems with the global fitting method. We note multiple issues, including problems with reproducing the experimental results, especially in the case of experiments that do not provide adequate data releases. We discuss an unexpected 5 MeV excess, observed in the reactor flux energy spectrum, that may be affecting the oscillation interpretation of the short baseline reactor data. We emphasize the care that must be taken in mapping to the true neutrino energy in the case of oscillation experiments that are subject to multiple interaction modes and nuclear effects. We point to problems with the “Parameter-Goodness-of-Fit test” that is used to quantify the tension. Lastly, we point out that analyses presenting limits often receive less scrutiny that signals. While we provide a snapshot of the status of sterile neutrino searches today and global fits to their interpretation, we emphasize that this is a fast-moving field. We briefly review experiments that are expected to report new data in the immediate future. Lastly, we consider the 5-year horizon, where we propose that decay-at-rest neutrino sources are the best method of finally resolving the confusing situation.
SYSTEMIC RISK: THE EFFECT OF MARKET CONFIDENCE

In a crisis, when faced with insolvency, banks can sell stock in a dilutive offering in the stock market and borrow money in order to raise funds. We propose a simple model to find the maximum amou...
CEO Influence on Funds from Operations (FFO) Adjustment for Real Estate Investment Trusts (REITs)

This paper investigates the non-GAAP performance measures of the REIT industry, specifically the difference (FFO adjustment) between concurrent FFO and Net Income (NI). Using the U.S. Equity REIT data from 1993 to 2018, we first find evidence that both NI and FFO are associated with REIT market-adjusted stock returns, suggesting both contain information that is valuable to investors. Second, we document a significant and positive relationship between contemporaneous FFO adjustment and NI, indicating a possible “selective” and “intentional” inclusion and/or omission of “good” vs. “bad” news in FFO reporting. Third, we find direct evidence that more powerful CEOs are indeed associated with higher FFO adjustments, suggesting CEOs’ involvement in hiding subpar performance. Finally, we focus our attention on a more recent period, when the National Association of Real Estate Investment Trusts (NAREIT) provided additional clarifications and guidelines, and the U.S. Securities and Exchange Commission (SEC) increased scrutiny on FFO reporting. Our results show a diminished “manipulation” for the majority of the REITs, suggesting these guidelines and scrutiny have achieved their intended purposes. While non-GAAP performance measures might supply additional information to investors, our results indicate that providing continuous guidance and monitoring is essential.
Membrane orientation and oligomerization of the melanocortin receptor accessory protein 2.

The melanocortin receptor accessory protein 2 (MRAP2) plays a pivotal role in the regulation of several G protein–coupled receptors that are essential for energy balance and food intake. MRAP2 loss-of-function results in obesity in mammals. MRAP2 and its homolog MRAP1 have an unusual membrane topology and are the only known eukaryotic proteins that thread into the membrane in both orientations. In this study, we demonstrate that the conserved polybasic motif that dictates the membrane topology and dimerization of MRAP1 does not control the membrane orientation and dimerization of MRAP2. We also show that MRAP2 dimerizes through its transmembrane domain and can form higher-order oligomers that arrange MRAP2 monomers in a parallel orientation. Investigating the molecular details of MRAP2 structure is essential for understanding the mechanism by which it regulates G protein–coupled receptors and will aid in elucidating the pathways involved in metabolic dysfunction.
Fundamental Results on $s$-Closures

Abstract This paper establishes the fundamental properties of the s-closures, a recently introduced family of closure operations on ideals of rings of positive characteristic. The behavior of the s-closure of homogeneous ideals in graded rings is studied, and criteria are given for when the s-closure of an ideal can be described exactly in terms of its tight closure and rational powers. Sufficient conditions are established for the weak s-closure to equal to the s-closure. A generalization of the Briancon-Skoda theorem is given which compares any two different s-closures applied to powers of the same ideal.
Lifting heptagon symbols to functions

Seven-point amplitudes in planar $$ \mathcal{N} $$ = 4 super-Yang-Mills theory have previously been constructed through four loops using the Steinmann cluster bootstrap, but only at the level of the symbol. We promote these symbols to actual functions, by specifying their first derivatives and boundary conditions on a particular two-dimensional surface. To do this, we impose branch-cut conditions and construct the entire heptagon function space through weight six. We plot the amplitudes on a few lines in the bulk Euclidean region, and explore the properties of the heptagon function space under the coaction associated with multiple polylogarithms.
Use of machine learning in geriatric clinical care for chronic diseases: a systematic literature review.

Objectives Geriatric clinical care is a multidisciplinary assessment designed to evaluate older patients' (age 65 years and above) functional ability, physical health, and cognitive well-being. The majority of these patients suffer from multiple chronic conditions and require special attention. Recently, hospitals utilize various artificial intelligence (AI) systems to improve care for elderly patients. The purpose of this systematic literature review is to understand the current use of AI systems, particularly machine learning (ML), in geriatric clinical care for chronic diseases. Materials and methods We restricted our search to eight databases, namely PubMed, WorldCat, MEDLINE, ProQuest, ScienceDirect, SpringerLink, Wiley, and ERIC, to analyze research articles published in English between January 2010 and June 2019. We focused on studies that used ML algorithms in the care of geriatrics patients with chronic conditions. Results We identified 35 eligible studies and classified in three groups: psychological disorder (n = 22), eye diseases (n = 6), and others (n = 7). This review identified the lack of standardized ML evaluation metrics and the need for data governance specific to health care applications. Conclusion More studies and ML standardization tailored to health care applications are required to confirm whether ML could aid in improving geriatric clinical care.
Partial Reconfiguration for Design Optimization

FPGA designers have traditionally shared a similar design methodology with ASIC designers. Most notably, at design time, FPGA designers commit to a fixed allocation of logic resources to modules in a design. At runtime, some of the occupied resources could be left under-utilized due to hard-to-avoid sources of inefficiencies (e.g., operation dependencies, unbalanced pipelines). With partial reconfiguration (PR), FPGA resources can be re-allocated over time. Therefore, using PR, a designer can attempt to reduce under-utilization with better area-time scheduling. In this paper, we offer definitions, insights, and equations to explain when, how, and why PR-style designs can improve over the performance-area Pareto front of ASIC-style designs (without PR). We first introduce the concept of area-time volume to explain why PR-style designs can improve upon ASIC-style designs. We identify resource under-utilization as an opportunity that can be exploited by PR-style designs. We then present a first-order analytical model to help a designer decide if a PR-style design can be beneficial. When it is the case, the model points to the most suitable PR execution strategy and provides an estimate of the improvement. The model is validated in a case study.
Simplified landscapes for optimization of shaken lattice interferometry

Motivated by recent results using shaken optical lattices to perform atom interferometry, we explore the splitting of an atom cloud trapped in a phase-modulated ('shaken') optical lattice. Using a simple analytic model we are able to show that we can obtain the simplest case of ±2k L splitting via single-frequency shaking. This is confirmed both via simulation and experiment. Furthermore, we are able to split with a relative phase θ between the two split arms of 0 or π depending on our shaking frequency. Addressing higher-order splitting, we determine that ±6k L splitting is sufficient to be able to accelerate the atoms in counterpropagating lattices. Finally, we show that we can use a genetic algorithm to optimize ±4k L and ±6k L splitting to within ≈0.1% by restricting our optimization to the resonance frequencies corresponding to single- and two-photon transitions between Bloch bands. As a proof-of-principle, an experimental demonstration of simplified optimization of 4k L splitting is presented.
Vanishing theorems and conjectures for the, $\ell ^2$--homology of right-angled Coxeter groups

Associated to any nite flag complex L there is a right-angled Coxeter group WL and a cubical complex L on which WL acts properly and cocompactly. Its two most salient features are that (1) the link of each vertex of L is L and (2) L is contractible. It follows that if L is a triangulation of S n 1 ,t hen L is a contractible n{manifold. We describe a program for proving the Singer Conjecture (on the vanishing of the reduced ‘ 2 {homology except in the middle dimension) in the case of L where L is a triangulation of S n 1 . The program succeeds when n 4. This implies the Charney{Davis Conjecture on flag triangulations ofS 3 . It also implies the following special case of the Hopf{Chern Conjecture: every closed 4{manifold with a nonpositively curved, piecewise Euclidean, cubical structure has nonnegative Euler characteristic. Our methods suggest the following generalization of the Singer Conjecture.
Subcompletions of representable relation algebras

The variety of representable relation algebras is closed under canonical extensions but not closed under completions. What variety of relation algebras is generated by completions of representable relation algebras? Does it contain all relation algebras? It contains all representable finite relation algebras, and this paper shows that it contains many non-representable finite relation algebras as well. For example, every Monk algebra with six or more special elements (called “colors”) is a subalgebra of the completion of an atomic symmetric integral representable relation algebra whose finitely-generated subalgebras are finite.
A representation-theoretic proof of the branching rule for Macdonald polynomials

We give a new representation-theoretic proof of the branching rule for Macdonald polynomials using the Etingof-Kirillov Jr. expression for Macdonald polynomials as traces of intertwiners of $U_q(gl_n)$. In the Gelfand-Tsetlin basis, we show that diagonal matrix elements of such intertwiners are given by application of Macdonald's operators to a simple kernel. An essential ingredient in the proof is a map between spherical parts of double affine Hecke algebras of different ranks based upon the Dunkl-Kasatani conjecture.
Modular orbits at higher genus

We extend the modular orbits method of constructing a two-dimensional orbifold conformal field theory to higher genus Riemann surfaces. We find that partition functions on surfaces of arbitrary genus can be constructed by a straightforward generalization of the rules that one would apply to the torus. We demonstrate how one can use these higher genus objects to compute correlation functions and OPE coefficients in the underlying theory. In the case of orbifolds of free bosonic theories by subgroups of continuous symmetries, we can give the explicit results of our procedure for symmetric and asymmetric orbifolds by cyclic groups.
Provably positive high-order schemes for ideal magnetohydrodynamics: analysis on general meshes

This paper proposes and analyzes arbitrarily high-order discontinuous Galerkin (DG) and finite volume methods which provably preserve the positivity of density and pressure for the ideal magnetohydrodynamics (MHD) on general meshes. Unified auxiliary theories are built for rigorously analyzing the positivity-preserving (PP) property of numerical MHD schemes with a Harten–Lax–van Leer (HLL) type flux on polytopal meshes in any space dimension. The main challenges overcome here include establishing certain relation between the PP property and a discrete divergence of magnetic field on general meshes, and estimating proper wave speeds in the HLL flux to ensure the PP property. In the 1D case, we prove that the standard DG and finite volume methods with the proposed HLL flux are PP, under a condition accessible by a PP limiter. For the multidimensional conservative MHD system, the standard DG methods with a PP limiter are not PP in general, due to the effect of unavoidable divergence error in the magnetic field. We construct provably PP high-order DG and finite volume schemes by proper discretization of the symmetrizable MHD system, with two divergence-controlling techniques: the locally divergence-free elements and suitably discretized Godunov–Powell source term. The former technique leads to zero divergence within each cell, while the latter controls the divergence error across cell interfaces. Our analysis reveals in theory that a coupling of these two techniques is very important for positivity preservation, as they exactly contribute the discrete divergence terms which are absent in standard multidimensional DG schemes but crucial for ensuring the PP property. Several numerical tests further confirm the PP property and the effectiveness of the proposed PP schemes. Unlike the conservative MHD system, the exact smooth solutions of the symmetrizable MHD system are proved to retain the positivity even if the divergence-free condition is not satisfied. Our analysis and findings further the understanding, at both discrete and continuous levels, of the relation between the PP property and the divergence-free constraint.
Conv-TasNet: Surpassing Ideal Time–Frequency Magnitude Masking for Speech Separation

Single-channel, speaker-independent speech separation methods have recently seen great progress. However, the accuracy, latency, and computational cost of such methods remain insufficient. The majority of the previous methods have formulated the separation problem through the time–frequency representation of the mixed signal, which has several drawbacks, including the decoupling of the phase and magnitude of the signal, the suboptimality of time–frequency representation for speech separation, and the long latency in calculating the spectrograms. To address these shortcomings, we propose a fully convolutional time-domain audio separation network Conv-TasNet, a deep learning framework for end-to-end time-domain speech separation. Conv-TasNet uses a linear encoder to generate a representation of the speech waveform optimized for separating individual speakers. Speaker separation is achieved by applying a set of weighting functions masks to the encoder output. The modified encoder representations are then inverted back to the waveforms using a linear decoder. The masks are found using a temporal convolutional network consisting of stacked one-dimensional dilated convolutional blocks, which allows the network to model the long-term dependencies of the speech signal while maintaining a small model size. The proposed Conv-TasNet system significantly outperforms previous time–frequency masking methods in separating two- and three-speaker mixtures. Additionally, Conv-TasNet surpasses several ideal time–frequency magnitude masks in two-speaker speech separation as evaluated by both objective distortion measures and subjective quality assessment by human listeners. Finally, Conv-TasNet has a significantly smaller model size and a shorter minimum latency, making it a suitable solution for both offline and real-time speech separation applications. This study, therefore, represents a major step toward the realization of speech separation systems for real-world speech processing technologies.
Limit Shape of Subpartition-Maximizing Partitions

This is an expository note answering a question posed to us by Richard Stanley, in which we prove a limit shape theorem for partitions of n which maximize the number of subpartitions. The limit shape and the growth rate of the number of subpartitions are explicit. The key ideas are to use large deviations estimates for random walks, together with convex analysis and the Hardy–Ramanujan asymptotics. Our limit shape coincides with Vershik’s limit shape for uniform random partitions.
Normal-mode-based analysis of electron plasma waves with second-order Hermitian formalism

The classic problem of the dynamic evolution and Landau damping of linear Langmuir electron waves in a collisionless plasma with Maxwellian background is cast as a second-order, self-adjoint problem with a continuum spectrum of real and positive squared frequencies. The corresponding complete basis of singular normal modes is obtained, along with their orthogonality relation. This yields easily the general expression of the time-reversal-invariant solution for any initial-value problem. Examples are given for specific initial conditions that illustrate different behaviors of the Landau-damped macroscopic moments of the perturbations.
The Besicovitch–Federer projection theorem is false in every infinite-dimensional Banach space

We construct a purely unrectifiable set of finite H 1-measure in every infinite-dimensional separable Banach space X whose image under every 0 ≠ x* ∈ X* has positive Lebesgue measure. This demonstrates completely the failure of the Besicovitch–Federer projection theorem in infinitedimensional Banach spaces.
Transit Target Selection Using Reduced Proper Motions

In searches for planetary transits in the field, well over half of the survey stars are typically giants or other stars that are too large to permit straightforward detection of planets. For all-sky searches of bright V d11 stars, the fraction is � 90%. We show that the great majority of these contaminants can be removed from the sample by analyzing their reduced proper motions (RPMs); giants have much lower RPMs than dwarfs of the same color. We use Hipparcos data to design a RPM selection function that eliminates most evolved stars, while rejecting only 9% of viable transit targets. Our method can be applied using existing or soon-to-bereleased all-sky data to stars V < 12:5 in the northern hemisphere and V < 12 in the southern hemisphere. The method degrades at fainter magnitudes, but does so gracefully. For example, at V ¼ 14 it can still be used
DEFORMATION QUANTIZATION: QUANTUM MECHANICS LIVES AND WORKS IN PHASE-SPACE

Wigner's quasi-probability distribution function in phase-space is a special (Weyl) representation of the density matrix. It has been useful in describing quantum transport in quantum optics; nuclear physics; decoherence (e.g. quantum computing); quantum chaos; "Welcher Weg" discussions; semiclassical limits. It is also of importance in signal processing. Nevertheless, a remarkable aspect of its internal logic, pioneered by Moyal, has only emerged in the last quarter-century: It furnishes a third, alternative, formulation of Quantum Mechanics, independent of the conventional Hilbert Space, or Path Integral formulations. In this logically complete and self-standing formulation, one need not choose sides — coordinate or momentum space. It works in full phase-space, accommodating the uncertainty principle. This is an introductory overview of the formulation with simple illustrations.
Constant symplectic 2-groupoids

We propose a definition of symplectic 2-groupoid which includes integrations of Courant algebroids that have been recently constructed. We study in detail the simple but illustrative case of constant symplectic 2-groupoids. We show that the constant symplectic 2-groupoids are, up to equivalence, in one-to-one correspondence with a simple class of Courant algebroids that we call constant Courant algebroids. Furthermore, we find a correspondence between certain Dirac structures and Lagrangian sub-2-groupoids.
Measurement Techniques for Thermal Conductivity and Interfacial Thermal Conductance of Bulk and Thin Film Materials

Thermal conductivity and interfacial thermal conductance play crucial roles in the design of engineering systems where temperature and thermal stress are of concerns. To date, a variety of measurement techniques are available for both bulk and thin film solid-state materials with a broad temperature range. For thermal characterization of bulk material, the steady-state absolute method, laser flash diffusivity method, and transient plane source method are most used. For thin film measurement, the 3{\omega} method and transient thermoreflectance technique including both frequency-domain and time-domain analysis are employed widely. This work reviews several most commonly used measurement techniques. In general, it is a very challenging task to determine thermal conductivity and interface contact resistance with less than 5% error. Selecting a specific measurement technique to characterize thermal properties need to be based on: 1) knowledge on the sample whose thermophysical properties is to be determined, including the sample geometry and size, and preparation method; 2) understanding of fundamentals and procedures of the testing technique and equipment, for example, some techniques are limited to samples with specific geometrics and some are limited to specific range of thermophysical properties; 3) understanding of the potential error sources which might affect the final results, for example, the convection and radiation heat losses.
$a$-Points of the Riemann zeta-function on the critical line

We investigate the proportion of the nontrivial roots of the equation $\zeta (s)=a$, which lie on the line $\Re s=1/2$ for $a \in \mathbb C$ not equal to zero. We show that at most one-half of these points lie on the line $\Re s=1/2$. Moreover, assuming a spacing condition on the ordinates of zeros of the Riemann zeta-function, we prove that zero percent of the nontrivial solutions to $\zeta (s)=a$ lie on the line $\Re s=1/2$ for any nonzero complex number $a$.
Transport coefficients in high temperature gauge theories (I): leading-log results

Leading-log results are derived for the shear viscosity, electrical conductivity and flavor diffusion constants in both abelian and non-abelian high temperature gauge theories with various matter field content.
Effects of medium range order on propagon thermal conductivity in amorphous silicon

We discuss the dependence of the propagon contribution to thermal conductivity on the medium range order (MRO) in amorphous silicon. Three different amorphous structures with the same size of 3.28 nm were studied. Among these three structures, two structures were constructed with experimentally observed MRO [M. M. J. Treacy and K. B. Borisenko, Science 335, 950 (2012)], and the other structure is from continuous random network (CRN), which lacks MRO and thus represents a randomized amorphous structure [G. Barkema and N. Mousseau, Phys. Rev. B 62, 4985 (2000)]. Using the simulated fluctuation electron microscopy and dihedral angle distribution, we confirm that the first two structures contain MRO in the length scale of 10–20 A while the CRN structure does not. The transport of propagons in the MRO and CRN structures is compared using the dynamic structural factor calculation and normal mode decomposition of the molecular dynamics simulation data, showing noticeably longer lifetime of propagons in MRO structures than in the CRN structure. The propagon thermal conductivity in MRO structures is estimated to be 50% larger than that in the CRN structure.
Dirac operator as a random matrix and the quenched limit of QCD with chemical potential

The behavior of quenched QCD at nonzero chemical potential μ has been a long-standing puzzle. An explicit solution is found using the random matrix approach to chiral symmetry breaking. At nonzero μ the quenched QCD is not a simple n → 0 limit of a theory with n quarks; a naive ‘replica trick’ fails. A limit that leads to the quenched QCD is that of a theory with 2n quarks: n quarks with original action and n quarks with conjugate action.
Fusion Rings of Loop Group Representations

We compute the fusion rings of positive energy representations of the loop groups of the simple, simply connected Lie groups.
Investigating the Role of Model-Based Reasoning While Troubleshooting an Electric Circuit.

Troubleshooting a malfunctioning apparatus engages students in the core scientific practice of modeling.
Singular set of a Levi-flat hypersurface is Levi-flat

We study the singular set of a singular Levi-flat real-analytic hypersurface. We prove that the singular set of such a hypersurface is Levi-flat in the appropriate sense. We also show that if the singular set is small enough, then the Levi-foliation extends to a singular codimension one holomorphic foliation of a neighborhood of the hypersurface.
All-mechanical quantum noise cancellation for accelerometry: broadband with momentum measurements, narrow band without

We show that the ability to make direct measurements of momentum, in addition to the usual direct measurements of position, allows a simple configuration of two identical mechanical oscillators to be used for broadband back-action-free force metrology. This would eliminate the need for an optical reference oscillator in the scheme of Tsang and Caves (2010 Phys. Rev. Lett. 105 123601), along with its associated disadvantages. We also show that if one is restricted to position measurements alone then two copies of the same two-oscillator configuration can be used for narrow-band back-action-free force metrology.
Proximity‐Induced Topological Transition and Strain‐Induced Charge Transfer in Graphene/MoS2 Bilayer Heterostructures

Graphene/MoS2 heterostructures are formed by combining the nanosheets of graphene and monolayer MoS2. The electronic features of both constituent monolayers are rather well-preserved in the resultant heterostructure due to the weak van der Waals interaction between the layers. However, the proximity of MoS2 induces strong spin orbit coupling effect of strength ~1 meV in graphene, which is nearly three orders of magnitude larger than the intrinsic spin orbit coupling of pristine graphene. This opens a bandgap in graphene and further causes anticrossings of the spin-nondegenerate bands near the Dirac point. Lattice incommensurate graphene/MoS2 heterostructure exhibits interesting moire' patterns which have been observed in experiments. The electronic bandstructure of heterostructure is very sensitive to biaxial strain and interlayer twist. Although the Dirac cone of graphene remains intact and no charge-transfer between graphene and MoS2 layers occurs at ambient conditions, a strain-induced charge-transfer can be realized in graphene/MoS2 heterostructure. Application of a gate voltage reveals the occurrence of a topological phase transition in graphene/MoS2 heterostructure. In this chapter, we discuss the crystal structure, interlayer effects, electronic structure, spin states, and effects due to strain and substrate proximity on the electronic properties of graphene/MoS2 heterostructure. We further present an overview of the distinct topological quantum phases of graphene/MoS2 heterostructure and review the recent advancements in this field.