cssi/SciSciGPT-SciSciNet huggingface dataset:
How can we partner with electronic health record vendors on the complex journey to safer health care

The Office of the National Coordinator for Health Information Technology released the Safety Assurance Factors for EHR Resilience (SAFER) guides in 2014. Our group developed these guides covering key facets of both electronic health record (EHR) infrastructure (eg, system configuration, contingency planning for downtime, and system-to-system interfaces) and clinical processes (eg, computer-based provider order entry with clinical decision support, test result reporting, patient identification, and clinician-to-clinician communication). The SAFER guides encourage healthy relationships between EHR vendors and users. We conducted a qualitative study over 12 months. We visited 9 health care organizations ranging in size from 1-doctor outpatient clinics to large, multisite, multihospital integrated delivery networks. We interviewed and observed clinicians, IT professionals, and administrators. From the interview transcripts and observation field notes, we identified overarching themes: technical functionality, usability, standards, testing, workflow processes, personnel to support implementation and use, infrastructure, and clinical content. In addition, we identified health care organization-EHR vendor working relationships: marine drill sergeant, mentor, development partner, seller, and parasite. We encourage health care organizations and EHR vendors to develop healthy working relationships to help address the tasks required to design, develop, implement, and maintain EHRs required to achieve safer and higher quality health care.
Hybrid Systems Differential Dynamic Programming for Whole-Body Motion Planning of Legged Robots

This letter presents a Differential Dynamic Programming (DDP) framework for trajectory optimization (TO) of hybrid systems with state-based switching. The proposed Hybrid Systems DDP (HS-DDP) approach is considered for application to whole-body motion planning with legged robots. Specifically, HS-DDP incorporates three algorithmic advances: an impact-aware DDP step addressing the impact event in legged locomotion, an Augmented Lagrangian (AL) method dealing with the switching constraint, and a Switching Time Optimization (STO) algorithm that optimizes switching times by leveraging the structure of DDP. Further, a Relaxed Barrier (ReB) method is used to manage inequality constraints and is integrated into HS-DDP for locomotion planning. The performance of the developed algorithms is benchmarked on a simulation model of the MIT Mini Cheetah executing a bounding gait. We demonstrate the effectiveness of AL and ReB for handling switching constraints, friction constraints, and torque limits. By comparing to previous solutions, we show that the STO algorithm achieves 2.3 times more reduction of total switching times, demonstrating the efficiency of our method.
Caregiver Report of the Utilization of School-Based Services and Supports Among Clinically Anxious Youth:

Despite the high prevalence of and documented impairment associated with pediatric anxiety disorders, less than half of youth access mental health services. This study examined (a) the utilization ...
An immunohistochemical prostate cell identification key indicates that aging shifts procollagen 1A1 production from myofibroblasts to fibroblasts in dogs prone to prostate-related urinary dysfunction.

Background The identity and spatial distribution of prostatic cell types has been determined in humans but not in dogs, even though aging- and prostate-related voiding disorders are common in both species and mechanistic factors, such as prostatic collagen accumulation, appear to be shared between species. In this publication we characterize the regional distribution of prostatic cell types in the young intact dog to enable comparisons with human and mice and we examine how the cellular source of procollagen 1A1 changes with age in intact male dogs. Methods A multichotomous decision tree involving sequential immunohistochemical stains was validated for use in dog and used to identify specific prostatic cell types and determine their distribution in the capsule, peripheral, periurethral and urethral regions of the young intact canine prostate. Prostatic cells identified using this technique include perivascular smooth muscle cells, pericytes, endothelial cells, luminal, intermediate, and basal epithelial cells, neuroendocrine cells, myofibroblasts, fibroblasts, fibrocytes, and other hematolymphoid cells. To enhance rigor and transparency, all high resolution images (representative images shown in the figures and biological replicates) are available through the GUDMAP database at https://doi.org/10.25548/16-WMM4. Results The prostatic peripheral region harbors the largest proportion of epithelial cells. Aging does not change the density of hematolymphoid cells, fibroblasts, and myofibroblasts in the peripheral region or in the fibromuscular capsule, regions where we previously observed aging- and androgen-mediated increases in prostatic collagen abundance Instead, we observed aging-related changes the procollagen 1A1 positive prostatic cell identity from a myofibroblast to a fibroblast. Conclusions Hematolymphoid cells and myofibroblasts are often identified as sources of collagen in tissues prone to aging-related fibrosis. We show that these are not the likely sources of pathological collagen synthesis in older intact male dogs. Instead, we identify an aging-related shift in the prostatic cell type producing procollagen 1A1 that will help direct development of cell type and prostate appropriate therapeutics for collagen accumulation.
Difference potentials method for models with dynamic boundary conditions and bulk-surface problems

In this work, we consider parabolic models with dynamic boundary conditions and parabolic bulk-surface problems in 3D. Such partial differential equations–based models describe phenomena that happen both on the surface and in the bulk/domain. These problems may appear in many applications, ranging from cell dynamics in biology, to grain growth models in polycrystalline materials. Using difference potentials framework, we develop novel numerical algorithms for the approximation of the problems. The constructed algorithms efficiently and accurately handle the coupling of the models in the bulk and on the surface, approximate 3D irregular geometry in the bulk by the use of only Cartesian meshes, employ fast Poisson solvers, and utilize spectral approximation on the surface. Several numerical tests are given to illustrate the robustness of the developed numerical algorithms.
Last Iterate is Slower than Averaged Iterate in Smooth Convex-Concave Saddle Point Problems

In this paper we study the smooth convex-concave saddle point problem. Specifically, we analyze the last iterate convergence properties of the Extragradient (EG) algorithm. It is well known that the ergodic (averaged) iterates of EG converge at a rate of O(1/T) (Nemirovski, 2004). In this paper, we show that the last iterate of EG converges at a rate of O(1/√T). To the best of our knowledge, this is the first paper to provide a convergence rate guarantee for the last iterate of EG for the smooth convex-concave saddle point problem. Moreover, we show that this rate is tight by proving a lower bound of Omega(1/√T) for the last iterate. This lower bound therefore shows a quadratic separation of the convergence rates of ergodic and last iterates in smooth convex-concave saddle point problems.
Change Detection in Complex Dynamical Systems Using Intrinsic Phase and Amplitude Synchronization

We present an approach for the detection of sharp change points (short-lived and persistent) in nonlinear and nonstationary dynamic systems under high levels of noise by tracking the local phase and amplitude synchronization among the components of a univariate time series signal. The signal components are derived via Intrinsic Time scale Decomposition (ITD)–a nonlinear, non-parametric analysis method. We show that the signatures of sharp change points are retained across multiple ITD components with a significantly higher probability as compared to random signal fluctuations. Theoretical results are presented to show that combining the change point information retained across a specific set of ITD components offers the possibility of detecting sharp transitions with high specificity and sensitivity. Subsequently, we introduce a concept of mutual agreement to identify the set of ITD components that are most likely to capture the information about dynamical changes of interest and define an InSync statistic to capture this local information. Extensive numerical, as well as real-world case studies involving benchmark neurophysiological processes and industrial machine sensor data, suggest that the present method can detect sharp change points, on an average 62% earlier (in terms of average run length) as compared to other contemporary methods tested.
Mod-two cohomology rings of alternating groups

We calculate the mod-two cohomology of all alternating groups together, with both cup and transfer product structures, which in particular determines the additive structure and ring structure of the cohomology of individual groups. We show that there are no nilpotent elements in the cohomology rings of individual alternating groups. We calculate the action of the Steenrod algebra and discuss individual component rings. A range of techniques is needed: an almost Hopf ring structure associated to the embeddings of products of alternating groups, the Gysin sequence relating the cohomology of alternating groups to that of symmetric groups, Fox-Neuwirth resolutions, and restriction to elementary abelian subgroups.
Log-Linear Bayesian Additive Regression Trees for Multinomial Logistic and Count Regression Models

We introduce Bayesian additive regression trees (BART) for log-linear models including multinomial logistic regression and count regression with zero-inflation and overdispersion. BART has been app...
Low Complexity Algorithms for Transmission of Short Blocks over the BSC with Full Feedback

Building on the work of Horstein, Shayevitz and Feder, and Naghshvar et al., this paper presents algorithms for low-complexity sequential transmission of a k-bit message over the binary symmetric channel (BSC) with full, noiseless feedback. To lower complexity, this paper shows that the initial k binary transmissions can be sent before any feedback is required and groups messages with equal posteriors to reduce the number of posterior updates from exponential in k to linear in k. Simulation results demonstrate that achievable rates for this full, noiseless feedback system approach capacity rapidly as a function of average blocklength, faster than known finite-blocklength lower bounds on achievable rate with noiseless active feedback and significantly faster than finite-blocklength lower bounds for a stop feedback system.
Moral hazard effects of supplemental private health insurance in Korea.

Abstract Supplemental private health insurance has gained popularity despite having a mandatory social health insurance program in Korea. Private insurance supplements the social insurance program by covering co-pays and services not covered by social insurance. Using longitudinal microdata from the 2008–2014 Korea Health Panel, this study finds evidence of favorable selection into supplemental private insurance. Results show that supplemental private insurance increases outpatient and hospitalization utilization. Private health insurance generates welfare benefits especially among the elderly and low-income individuals, though the coverage rate for these groups is low.
Heating Rates for Protons and Electrons in Polar Coronal Holes: Empirical Constraints from the Ultraviolet Coronagraph Spectrometer

Ultraviolet spectroscopy of the extended solar corona is a powerful tool for measuring the properties of protons, electrons, and heavy ions in the accelerating solar wind. The large coronal holes that expand up from the north and south poles at solar minimum are low-density collisionless regions in which it is possible to detect departures from one-fluid thermal equilibrium. An accurate characterization of these departures is helpful in identifying the kinetic processes ultimately responsible for coronal heating. In this paper, Ultraviolet Coronagraph Spectrometer (UVCS) measurements of the H I Lyman alpha line are analyzed to constrain values for the solar wind speed, electron density, electron temperature, proton temperature (parallel and perpendicular to the magnetic field) and Alfven-wave amplitude. The analysis procedure involves creating a large randomized ensemble of empirical models, simulating their Lyman alpha profiles, and building posterior probability distributions for only the models that agree with the UVCS data. The resulting temperatures do not exhibit a great deal of radial variation between heliocentric distances of 1.4 and 4 solar radii. Typical values for the electron, parallel proton, and perpendicular proton temperatures are 1.2, 1.8, and 1.9 MK, respectively. Resulting values for the "nonthermal" Alfven wave amplitude show evidence for weak dissipation, with a total energy-loss rate that agrees well with an independently derived total heating rate for the protons and electrons. The moderate Alfven-wave amplitudes appear to resolve some tension in the literature between competing claims of both higher (undamped) and lower (heavily damped) values.
ORBITAL MAGNETISM IN THE CUPRATES

The pseudogap phase of the cuprate superconductors is argued to be characterized by a hidden broken symmetry of d-wave character in the particle-hole channel that leads to staggered orbital magnetism. This proposal has many striking phenomenological consequences, but the most direct signature of this order should be visible in the neutron scattering experiments. The theoretical underpinning of these experiments is discussed.
Impact of Geographical Cohorting in the ICU: An Academic Tertiary Care Center Experience.

ICU is a multifaceted organization where multiple teams care for critically ill patients. In the current era, collaboration between teams and efficient workflows form the backbone of value-based care. Geographical cohorting is a widespread model for hospitalist rounding, but its role in ICUs is unclear. This study evaluates the outcomes of geographical cohorting in a large ICU of an Academic Health Center. Design This is a retrospective analysis of quality metrics collected 12 months pre- and post-implementation of geographical cohorting. Setting A total of 130 bedded ICU at tertiary academic health center in Midwest. Patients All patients admitted to the ICU. Interventions Our institution piloted the geographical cohorting model for critical care physician rounding on September 1, 2018. Measurements The quality metrics were categorized as ICU harm events and ICU hospital metrics. Team of critical care providers were surveyed 12 months after implementation. Main results The critical care utilization in the pre- and post-implementation numbers were similar for patient days (pre = 34,839, post = 35,155), central-line days (pre = 17,648, post = 19,224), and Foley catheter days (pre = 18,292, post = 17,364). The ICU length of stay was similar (4.9 d) in both pre- and post-intervention periods. Significant reduction in the incidence of Clostridium difficile infection (relative risk, -0.50; 95% CI, 0.25-0.96; p = 0.039), hospital-acquired pressure injury (relative risk, -0.60; 95% CI, 0.39-0.92; p = 0.020), central line-associated bloodstream infection incidence (relative risk, -0.19; 95% CI, 0.05-0.52; p = 0.008), and catheter-associated urinary tract infection (relative risk, -0.52; 95% CI, 0.29-0.93; p = 0.027). Healthcare providers perceived optimal utilization of their time, reduced interruptions, and improved coordination of care with geographical rounding. Conclusions Geographical cohorting improves coordination of care, physician workflow, and critical care quality metrics in very large ICUs.
Quantum group and magnetic translations. Bethe-Ansatz solution for bloch electrons in a magnetic field

We present a new approach to the problem of Bloch electrons in magnetic field, by making explicit a natural relation between magnetic translations and the quantum group U9(sl2). The approach allows to express the spectrum and the Bloch function as solutions of the Bethe-Ansatz equations typical for completely integrable quantum systems
Experimental demonstration of cascaded operation for two low-Bi NOLMs

Summary form only given. In summary, we experimentally verify cascadable operation of two low-birefringence nonlinear optical loop mirror (NOLM) logic gates pumped by an EDFL. We achieve a contrast ratio of 10.7:1 in the cascaded operation. The switching energy is 17 pJ, and the timing window is 2.7 pulse widths. We will also present simulation results that confirm and extend our experiments. This is an important first step toward cascading gates for header processing applications.
Ray tracing dynamic scenes using selective restructuring

We present a novel algorithm to selectively restructure bounding volume hierarchies (BVHs) for ray tracing dynamic scenes. We derive two new metrics to evaluate the culling efficiency and restructuring benefit of any BVH. Based on these metrics, we perform selective restructuring operations that efficiently reconstruct small portions of a BVH instead of the entire BVH. Our approach is general and applicable to complex and dynamic scenes, including topological changes. We use the selective restructuring algorithm to improve the performance of ray tracing dynamic scenes that consist of hundreds of thousands of triangles. In our benchmarks, we observe up to an order of magnitude improvement over prior BVH-based ray tracing algorithms.
Bailouts, Inflation, and Risk-Sharing in Monetary Unions

This paper presents a new rationalization for bailouts of sovereign debt in monetary unions, such as those observed during the recent Euro crisis. It introduces a model where member countries of the monetary union are ex-ante identical, and each derives utility from consumption and disutility from the union-wide inflation rate. The union’s central bank is utilitarian and lacks commitment. Countries borrow or save in a market for nominal sovereign debt in response to idiosyncratic income shocks, with countries that receive positive income shocks saving and countries that receive negative income shocks borrowing. Ex post, the monetary union’s central bank will attempt to devalue sovereign debt through surprise inflation, as this will redistribute income from rich creditor countries to poor debtor countries. Creditor countries choose to bailout debtor countries because bailouts will weaken the redistributive motives of the central bank and forestall surprise inflation. As bailouts in this environment constitute a payment from lucky creditor countries to unlucky debtor countries, they mimic a risk-sharing arrangement that insures against income shocks. The payments made by creditor countries are incentive-compatible due to the shared currency and inflation rate in the monetary union. This ability of countries to provide each other with incentive-compatible insurance constitutes a novel theory of optimal currency areas. This insurance benefit of the monetary union is largest for countries with negatively correlated income shocks, in contrast to the classic Mundell-Friedman optimal currency area criterion.
Precision Inclusive Higgs Physics at e+e− Colliders With Tracking Detectors and Without Calorimetry

A primary goal of a future e+e− collider program will be the precision measurement of Higgs boson properties. For practical reasons it is of interest to determine the minimal set of detector specifications required to reach this and other scientific goals. Here we investigate the precision obtainable for the e+e− → Zh → μ+μ−X inclusive cross section and the Higgs boson mass using the di-muon recoil method, considering a detector that has only an inner tracking system within a solenoidal magnetic field, surrounded by many nuclear interaction lengths of absorbing material, and an outer muon identification system. We find that the sensitivity achievable in these measurements with such a tracking detector is only marginally reduced compared to that expected for a general purpose detector with additional electromagnetic and hadronic calorimeter systems. The difference results mainly from multi-photon backgrounds that are not as easily rejected with tracking detectors. We also comment on the prospects for an analogous measurement of the e+e− → Zh → e+e−X inclusive cross section. Finally, we study searches for light scalars utilizing the di-muon recoil method, estimating the projected reach with a tracking or general purpose detector.
Application of Natural Resources Property Theory to Hidden Resources

The visualization of property and resources is a defining foundation of the construction and application of a property rights framework. When humans encounter resources they cannot see— or hidden resources—, they have difficulties imagining an appropriate property regime. These hidden resources include subsurface resources (oil and gas reservoirs, groundwater, pore space), biological resources (migration paths, plant and animal dormancy cycles), informal and unrecognized land titles, and extraplanetary resources (asteroid mining and water). As a result, we often apply an existing two-dimensional property framework from visible resources to three and four-dimensional hidden resources. This article argues that lacking the ability to see resources—resource blindness—directly impacts our ability to use, manage, and conserve them. Conversely, resource sight—the ability to see resources—can tremendously aid the development of an effective and efficient property rights framework. This article also contends that hidden resources are best governed when owners and users understand the resource’s scientific properties. And those properties are likewise better gathered when the natural resource is visible to the human eye. Finally, if resource sight cannot be acquired, this article proposes avoiding resource conflicts by creating small groups of local and knowledgeable community property owners to advise in the resource’s management and encourage cooperative development.
GENIEx: A Generalized Approach to Emulating Non-Ideality in Memristive Xbars using Neural Networks

Memristive crossbars have been extensively explored for deep learning accelerators due to their high on-chip storage density and efficient Matrix Vector Multiplication (MVM) compared to digital CMOS. However, their analog nature of computing poses significant issues due to various non-idealities such as: parasitic resistances, non-linear I-V characteristics of the memristor device etc. The non-idealities can have a detrimental impact on the functionality i.e. computational accuracy of crossbars. Past works have explored modeling the non-idealities using analytical techniques. However, several non-idealities have data dependent behavior. This can not be captured using analytical (non data-dependent) models thereby, limiting their suitability in predicting application accuracy. To address this, we propose a Generalized Approach to Emulating Non-Ideality in Memristive Crossbars using Neural Networks (GENIEx), which accurately captures the data-dependent nature of non-idealities. First, we perform extensive HSPICE simulations of crossbars with different voltage and conductance combinations. Based on the obtained data, we train a neural network to learn the transfer characteristics of the non-ideal crossbar. Next, we build a functional simulator which includes key architectural facets such as tiling, and bit-slicing to analyze the impact of non-idealities on the classification accuracy of large-scale neural networks. We show that GENIEx achieves low root mean square errors (RMSE) of 0.25 and 0.7 for low and high voltages, respectively, compared to HSPICE. Additionally, the GENIEx errors are 7× and 12.8× better than an analytical model which can only capture the linear non-idealities. Further, using the functional simulator and GENIEx, we demonstrate that an analytical model can overestimate the degradation in classification accuracy by ≥ 10% on CIFAR-100 and 3.7% on ImageNet datasets compared to GENIEx.
Firm Dynamics and Trade

We review the literature that studies the dynamics of firms in foreign markets, at both the intensive and extensive margins, and their aggregate implications. We first summarize a set of micro fact...
Identifying SARS-CoV-2 Entry Inhibitors through Drug Repurposing Screens of SARS-S and MERS-S Pseudotyped Particles

While vaccine development will hopefully quell the global pandemic of COVID-19 caused by SARS-CoV-2, small molecule drugs that can effectively control SARS-CoV-2 infection are urgently needed. Here, inhibitors of spike (S) mediated cell entry were identified in a high throughput screen of an approved drugs library with SARS-S and MERS-S pseudotyped particle entry assays. We discovered six compounds (cepharanthine, abemaciclib, osimertinib, trimipramine, colforsin, and ingenol) to be broad spectrum inhibitors for spike-mediated entry. This work could contribute to the development of effective treatments against the initial stage of viral infection and provide mechanistic information that might aid the design of new drug combinations for clinical trials for COVID-19 patients.
The voltage boost enabled by luminescence extraction in solar cells

A new physical principle has emerged to produce record voltages and efficiencies in photovoltaic cells, “luminescence extraction.” This is exemplified by the mantra “a good solar cell should also be a good LED.” Luminescence extraction is the escape of internal photons out of the front surface of a solar cell. Basic thermodynamics says that the voltage boost should be related to concentration ratio, C, of a resource by ΔV=(kT/q)ln{C}. In light trapping, (i.e. when the solar cell is textured and has a perfect back mirror) the concentration ratio of photons C={4n2}, so one would expect a voltage boost of Δν=Μ ln{4n2} over a solar cell with no texture and zero back reflectivity, where n is the refractive index. Nevertheless, there has been ambiguity over the voltage benefit to be expected from perfect luminescence extraction. Do we gain an open circuit voltage boost of ΔV=(kT/q)ln{n 2 }, ΔV=(kT/q)ln{2n 2 }, or ΔV=(kT/q)ln{4n2}? What is responsible for this voltage ambiguity ΔV=(kT/q)ln{4}=36mVolts? We show that different results come about, depending on whether the photovoltaic cell is optically thin or thick to its internal luminescence. In realistic intermediate cases of optical thickness the voltage boost falls in between; ln{n2}qΔV/kT)<ln{4n2}.
Blocking Adversarial Influence in Social Networks

While social networks are widely used as a media for information diffusion, attackers can also strategically employ analytical tools, such as influence maximization, to maximize the spread of adversarial content through the networks. We investigate the problem of limiting the diffusion of negative information by blocking nodes and edges in the network. We formulate the interaction between the defender and the attacker as a Stackelberg game where the defender first chooses a set of nodes to block and then the attacker selects a set of seeds to spread negative information from. This yields an extremely complex bi-level optimization problem, particularly since even the standard influence measures are difficult to compute. Our approach is to approximate the attacker’s problem as the maximum node domination problem. To solve this problem, we first develop a method based on integer programming combined with constraint generation. Next, to improve scalability, we develop an approximate solution method that represents the attacker’s problem as an integer program, and then combines relaxation with duality to yield an upper bound on the defender’s objective that can be computed using mixed integer linear programming. Finally, we propose an even more scalable heuristic method that prunes nodes from the consideration set based on their degree. Extensive experiments demonstrate the efficacy of our approaches.
Robust high dimensional expectation maximization algorithm via trimmed hard thresholding

In this paper, we study the problem of estimating latent variable models with arbitrarily corrupted samples in high dimensional space (i.e., $$d\gg n$$ ) where the underlying parameter is assumed to be sparse. Specifically, we propose a method called Trimmed (Gradient) Expectation Maximization which adds a trimming gradients step and a hard thresholding step to the Expectation step (E-step) and the Maximization step (M-step), respectively. We show that under some mild assumptions and with an appropriate initialization, the algorithm is corruption-proofing and converges to the (near) optimal statistical rate geometrically when the fraction of the corrupted samples $$\epsilon$$ is bounded by $${\tilde{O}}\bigg (\frac{1}{\sqrt{n}}\bigg )$$ . Moreover, we apply our general framework to three canonical models: mixture of Gaussians, mixture of regressions and linear regression with missing covariates. Our theory is supported by thorough numerical results.
A Computational Analysis of Polarization on Indian and Pakistani Social Media

Between February 14, 2019 and March 4, 2019, a terrorist attack in Pulwama, Kashmir followed by retaliatory airstrikes led to rising tensions between India and Pakistan, two nuclear-armed countries. In this work, we examine polarizing messaging on Twitter during these events, particularly focusing on the positions of Indian and Pakistani politicians. We use a label propagation technique focused on hashtag co-occurrences to find polarizing tweets and users. Our analysis reveals that politicians in the ruling political party in India (BJP) used polarized hashtags and called for escalation of conflict more so than politicians from other parties. Our work offers the first analysis of how escalating tensions between India and Pakistan manifest on Twitter and provides a framework for studying polarizing messages.
Cosemisimple Hopf algebras are faithfully flat over Hopf subalgebras

The question of whether or not a Hopf algebra $H$ is faithfully flat over a Hopf subalgebra $A$ has received positive answers in several particular cases: when $H$ (or more generally, just $A$) is commutative, or cocommutative, or pointed, or when $K$ contains the coradical of $H$. We prove the statement in the title, adding the class of cosemisimple Hopf algebras to those known to be faithfully flat over all Hopf subalgebras. We also show that the third term of the resulting "exact sequence" $A\to H\to C$ is always a cosemisimple coalgebra, and that the expectation $H\to A$ is positive when $H$ is a CQG algebra.
Manifest Duality for Partially Massless Higher Spins

In four dimensions, partially massless fields of all spins and depths possess a duality invariance akin to electric-magnetic duality. We construct metric-like gauge invariant curvature tensors for partially massless fields of all integer spins and depths, and show how the partially massless equations of motion can be recovered from first order field equations and Bianchi identities for these curvatures. This formulation displays duality in its manifestly local and covariant form, in which it acts to interchange the field equations and Bianchi identities.
Approximate solutions of functional equations

Approximate solutions to functional evolution equations are constructed through a combination of series and conjugation methods, and relative errors are estimated. The methods are illustrated, both analytically and numerically, by construction of approximate continuous functional iterates for , sin x, and λx(1 − x). Simple functional conjugation by these functions, and their inverses, substantially improves the numerical accuracy of formal series approximations for their continuous iterates.
On positivity of the CM line bundle on K-moduli spaces

In this paper, we consider the CM line bundle on the K-moduli space, i.e., the moduli space parametrizing K-polystable Fano varieties. We prove it is ample on any proper subspace parametrizing reduced uniformly K-stable Fano varieties which conjecturally should be the entire moduli space. As a corollary, we prove that the moduli space parametrizing smoothable K-polystable Fano varieties is projective. During the course of proof, we develop a new invariant for filtrations which can be used to test various K-stability notions of Fano varieties.
Resummation of Jet Shapes and Extracting Properties of the Quark-Gluon Plasma

Understanding the properties of the quark-gluon plasma (QGP) that is produced in ultra-relativistic nucleus-nucleus collisions has been one of the top priorities of the heavy ion program at the LHC. Energetic jets are produced and subsequently quenched in the collisions. Such jet quenching phenomena provide promising tools to probe the medium properties by studying the modification of jets due to the medium interactions. Significant modifications of jet shapes have been measured. In this talk we focus on the calculation of jet shapes in both proton-proton and lead-lead collisions using soft-collinear effective theory (SCET), with Glauber gluon interactions in the medium. Large logarithms in jet shapes are resummed at next-to-leading logarithmic (NLL) accuracy by the renormalization-group evolution between hierarchical jet scales. The medium interactions contribute as power corrections, and we calculate the modification of jet shapes at leading order in opacity with the static QGP model. Preliminary results are presented with good agreement with the recent CMS jet shape measurements.
On the girth of (3,L) quasi-cyclic LDPC codes based on complete protographs

We consider the problem of constructing (3,L) quasi-cyclic low-density parity-check (LDPC) codes from complete protographs. A complete protograph is a small bipartite graph with two disjoint vertex sets such that every vertex in the variable-node set is connected to every vertex in the check-node set by a unique edge. This paper analyzes the required lifting factor for achieving girths of six or eight in the resulting quasi-cyclic codes with constraints on lifting. The required lifting factors provide lower bounds on the block-length of such codes.
Laser frequency offset locking scheme for high-field imaging of cold atoms

We present a simple and flexible frequency offset locking scheme developed for high-field imaging of ultra-cold atoms which relies on commercially available RF electronics only. The main new ingredient is the use of the sharp amplitude response of a “home-made” RF filter to provide an error signal for locking the lasers. We were able to offset lock two independent diode lasers within a capture range of hundreds of MHz, and with a tuning range of up to 1.4 GHz. The beat-note residual fluctuations for offset locked lasers are below 2 MHz for integration times of several hundreds of seconds.
A COMPARISON OF X-RAY AND OPTICAL EMISSION IN CASSIOPEIA A

Broadband optical and narrowband Si XIII X-ray images of the young Galactic supernova remnant Cassiopeia A (Cas A) obtained over several decades are used to investigate spatial and temporal emission correlations on both large and small angular scales. The data examined consist of optical and near-infrared ground-based and Hubble Space Telescope images taken between 1951 and 2011, and of X-ray images from Einstein, ROSAT, and Chandra taken between 1979 and 2013. We find weak spatial correlations between the remnant's X-ray and optical emission features on large scales, but several cases of good optical/X-ray correlations on small scales for features which have brightened due to recent interactions with the reverse shock. We also find instances (1) where a time delay is observed between the appearance of a feature's optical and X-ray emissions, (2) of displacements of several arcseconds between a feature's X-ray and optical emission peaks, and (3) of regions showing no corresponding X-ray or optical emissions. To explain this behavior, we propose a highly inhomogeneous density model for Cas A's ejecta consisting of small, dense optically emitting knots (n ∼10{sup 2-3} cm{sup –3}) and a much lower density (n ∼0.1-1 cm{sup –3}) diffuse X-ray emitting component often spatially associated withmore » optical emission knots. The X-ray emitting component is sometimes linked to optical clumps through shock-induced mass ablation generating trailing material leading to spatially offset X-ray/optical emissions. A range of ejecta densities can also explain the observed X-ray/optical time delays since the remnant's ≈5000 km s{sup –1} reverse shock heats dense ejecta clumps to temperatures around 3 × 10{sup 4} K relatively quickly, which then become optically bright while more diffuse ejecta become X-ray bright on longer timescales. Highly inhomogeneous ejecta as proposed here for Cas A may help explain some of the X-ray/optical emission features seen in other young core-collapse supernova remnants.« less
Realizing spin Hamiltonians in nanoscale active photonic lattices.

Spin models arise in the microscopic description of magnetic materials and have been recently used to map certain classes of optimization problems involving large degrees of freedom. In this regard, various optical implementations of such Hamiltonians have been demonstrated to quickly converge to the global minimum in the energy landscape. Yet, so far, an integrated nanophotonic platform capable of emulating complex magnetic materials is still missing. Here, we show that the cooperative interplay among vectorial electromagnetic modes in coupled metallic nanolasers can be utilized to implement certain types of spin Hamiltonians. Depending on the topology/geometry of the arrays, these structures can be governed by a classical XY Hamiltonian that exhibits ferromagnetic and antiferromagnetic couplings, as well as geometrical frustration. Our results pave the way towards a scalable nanophotonic platform to study spin exchange interactions and could address a variety of optimization problems. Vectorial electromagnetic modes in coupled metallic nanolasers are used to emulate the behaviour of complex magnetic materials, providing an integrated nanophotonic platform to study spin exchange interactions and map large-scale optimization problems.
Spin, statistics, orientations, unitarity

A topological quantum field theory is Hermitian if it is both oriented and complex-valued, and orientation-reversal agrees with complex-conjugation. A field theory satisfies spin-statistics if it is both spin and super, and $360^\circ$-rotation of the spin structure agrees with the operation of flipping the signs of all fermions. We set up a framework in which these two notions are precisely analogous. In this framework, field theories are defined over $\mathrm{Vect}_{\mathbb R}$, but rather than being defined in terms of a single tangential structure, they are defined in terms of a bundle of tangential structures over $\mathrm{Spec}(\mathbb R)$. Bundles of tangential structures may be etale-locally equivalent without being equivalent, and Hermitian field theories are nothing but the field theories controlled by the unique nontrivial bundle of tangential structures that is etale-locally equivalent to Orientations. This bundle owes its existence to the fact that $\pi_1^{et}(\mathrm{Spec}(\mathbb R)) = \pi_1{BO}$. We interpret Deligne's "existence of super fiber functors" theorem as implying that in a categorification of algebraic geometry in which symmetric monoidal categories replace commutative rings, $\pi_2^{et}(\mathrm{Spec}(\mathbb R)) = \pi_2{BO}$. There are eight bundles etale-locally equivalent to Spins, one of which is distinguished; upon unpacking the meaning of that distinguished tangential structure, one arrives at field theories that are both Hermitian and satisfy spin-statistics. Finally, we formulate a notion of "reflection-positivity" and prove that if an etale-locally-oriented field theory is reflection-positive then it is necessarily Hermitian, and if an etale-locally-spin field theory is reflection-positive then it necessarily both satisfies spin-statistics and is Hermitian. The latter result is a topological version of the famous Spin-Statistics Theorem.
Finding elementary formulas for theta functions associated to even sums of squares

Abstract This article discusses the classical problem of how to calculate r n ( m ) , the number of ways to represent an integer m by a sum of n squares from a computational efficiency viewpoint. Although this problem has been studied in great detail, there are very few formulas given for the purpose of computing r n ( m ) quickly. More precisely, for fixed n , we want a formula for r n ( m ) that computes in log-polynomial time (with respect to m ) when the prime factorization of m is given. Restricting to even n , we can view θ n ( q ) , the theta function associated to sums of n squares, as a modular form of weight n / 2 on Γ 1 ( 4 ) . In particular, we show that for only a small finite list of n can θ n be written as a linear combination consisting entirely of Eisenstein series and cusp forms with complex multiplication. These are the only n that give rise to “elementary” formulas for r n ( m ) , i.e. formulas such that for a prime p , r n ( p ) can be calculated in O ( log ( p ) ) -time. Viewing θ n ( q ) as one of the simpler examples of modular forms that are not strictly Eisenstein, this result motivates the necessity of a log-polynomial time algorithm that directly calculates the Fourier coefficients of modular forms in the generic situation when there is no such formula, as described in Couveignes and Edixhoven’s forthcoming book (for level 1 cases) and Peter Bruin’s Ph.D. thesis (for higher level, including 4).
Perturbation Formulas for Traces on Normed Ideals

We prove perturbation results for traces on normed ideals in semifinite von Neumann algebra factors. This includes the case of Dixmier traces. In particular, we establish existence of spectral shift measures with initial operators being dissipative or bounded, and show that these measures can have singular components in the case of Dixmier traces. We also establish a linearization formula for a Dixmier trace applied to perturbed operator functions, a result that does not typically hold for normal traces.
Various Condensed Matter Hamiltonians in Terms of U(2/2) Operators and Their Symmetry Structures

We rewrite various lattice Hamiltonians in condensed matter physics in terms of U(2/2) operators that we introduce. In this representation the symmetry structure of the models becomes clear. Especially, the Heisenberg, the supersymmetric t-J and a newly proposed high-Tc superconducting Hamiltonian reduce to the same form . This representation also gives us a systematic way of searching for the symmetries of the system.
TOWARD A NEUTRINO MASS MATRIX

One may identify the general properties of the neutrino mass matrix by generating many random mass matrices and testing them against the results of the neutrino experiments.
On Dirichlet-to-Neumann Maps, Nonlocal Interactions, and Some Applications to Fredholm Determinants

We consider Dirichlet-to-Neumann maps associated with (not necessarily self-adjoint) Schrodinger operators describing nonlocal interactions in \({L^2(\Omega; d^n x)}\) , where \({\Omega \subset \mathbb{R}^n}\) , \({n\in\mathbb{N}}\) , \({n\geq 2}\) , are open sets with a compact, nonempty boundary \({\partial\Omega}\) satisfying certain regularity conditions. As an application we describe a reduction of a certain ratio of Fredholm perturbation determinants associated with operators in \({L^2(\Omega; d^{n} x)}\) to Fredholm perturbation determinants associated with operators in \({L^2(\partial\Omega; d^{n-1} \sigma)}\) , \({n\in\mathbb{N}}\) , \({n\geq 2}\) . This leads to an extension of a variant of a celebrated formula due to Jost and Pais, which reduces the Fredholm perturbation determinant associated with a Schrodinger operator on the half-line \({(0,\infty)}\) , in the case of local interactions, to a simple Wronski determinant of appropriate distributional solutions of the underlying Schrodinger equation.
A Study of a Mini-Drift GEM Tracking Detector

A GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a 1.6 cm drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing the chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with $400~\mu \mathrm {m}$ pitch XY strips and the other consisted of $2\,\times \,10\mathrm {mm}^{2}$ chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Applications for large angle tracking detectors at RHIC and EIC are also discussed.
New perspectives on the Erlang-A queue

The nonstationary Erlang-A queue is a fundamental queueing model that is used to describe the dynamic behavior of large-scale multiserver service systems that may experience customer abandonments, such as call centers, hospitals, and urban mobility systems. In this paper we develop novel approximations to all of its transient and steady state moments, the moment generating function, and the cumulant generating function. We also provide precise bounds for the difference of our approximations and the true model. More importantly, we show that our approximations have explicit stochastic representations as shifted Poisson random variables. Moreover, we are also able to show that our approximations and bounds also hold for nonstationary Erlang-B and Erlang-C queueing models under certain stability conditions.
Knot Floer homology and the four-ball genus

We use the knot ltration on the Heegaard Floer complex d to dene an integer invariant (K) for knots. Like the classical signature, this invariant gives a homomorphism from the knot concordance group to Z. As such, it gives lower bounds for the slice genus (and hence also the unknotting number) of a knot; but unlike the signature, gives sharp bounds on the four-ball genera of torus knots. As another illustration, we calculate the invariant for several ten-crossing knots.