cssi/SciSciGPT-SciSciNet huggingface dataset:
Microstate Geometries and Entropy Enhancement

In string theory, black-hole backgrounds are far from unique and there are large families of completely smooth, horizonless geometries with the same structure as a black hole from infinity down to the neighborhood of the black-hole horizon. These microstate geometries cap off in foam of topological bubbles. I review some of the recent progress in constructing these smooth horizonless geometries and discuss some of the physical implications.
NINETY-DAY COST OF TREATMENT FOR PROXIMAL HUMERUS FRACTURES: AN ACUTE AND 90-DAY COST EVALUATION

Background Operative treatment of complex proximal humerus fractures remains controversial. The transition to value-based health care demands a better understanding of the costs associated with surgery. The purpose of this study was to examine the 90-day costs of three common surgical treatments for proximal humerus fractures and non-operative treatment and compare the costs associated with the initial-day and subsequent 89-days of care. Methods A query of the Humana insurance claims database was performed through the PearlDiver Supercomputer (Warsaw, IN) from 2010 to 2014 using the diagnosis codes for proximal humerus fractures together with current procedural terminology codes (CPT) for hemiarthroplasties (HA), open reduction internal fixation (ORIF), reverse shoulder arthroplasty (RSA) and nonoperative treatment (NO). Reimbursement from the insurance claims database was used as a marker for costs. The same day, subsequent 89-day, and ninety day costs were analyzed trough the use of descriptive and comparative statistical analysis. Results RSA was the most costly procedure for the same-day and 90-day costs (p Conclusion The 90-day costs for the surgical treatment of proximal humerus fractures are driven by the initial-day costs. RSA was associated with the highest cost, followed by HA and ORIF. NO management incurred the lowest costs.
The role of confidence and noncognitive skills for post-baccalaureate academic and labor market outcomes

Increasingly researchers include information about noncognitive abilities in their analyses of similar people’s educational choices and subsequent labor market outcomes. We contribute to this literature by considering the dual roles of confidence in one’s abilities and noncognitive skills and characteristics in predicting several subsequent MBA program and employment outcomes among a sample of GMAT test takers, with a focus on identifying possible gender differences in these relationships. Self-reported noncognitive skills correlate similarly for men’s and women’s managerial, earnings and employment satisfaction outcomes. In contrast, though, distinct gender differences emerge regarding perceptions of one’s mathematical and verbal ability—with confidence in quantitative ability especially associated with men’s and confidence in verbal ability mainly associated with women’s outcomes. Non-linearity analysis reveals that lower earnings are correlated with men who have low confidence in their quantitative ability and with women who have high confidence in their verbal ability.
Estimating Uncertainty Online Against an Adversary.

Assessing uncertainty is an important step towards ensuring the safety and reliability of machine learning systems. Existing uncertainty estimation techniques may fail when their modeling assumptions are not met, e.g. when the data distribution differs from the one seen at training time. Here, we propose techniques that assess a classification algorithm's uncertainty via calibrated probabilities (i.e. probabilities that match empirical outcome frequencies in the long run) and which are guaranteed to be reliable (i.e. accurate and calibrated) on out-of-distribution input, including input generated by an adversary. This represents an extension of classical online learning that handles uncertainty in addition to guaranteeing accuracy under adversarial assumptions. We establish formal guarantees for our methods, and we validate them on two real-world problems: question answering and medical diagnosis from genomic data.
Persistent Spread Measurement for Big Network Data Based on Register Intersection

Persistent spread measurement is to count the number of distinct elements that persist in each network flow for predefined time periods. It has many practical applications, including detecting long-term stealthy network activities in the background of normal-user activities, such as stealthy DDoS attack, stealthy network scan, or faked network trend, which cannot be detected by traditional flow cardinality measurement. With big network data, one challenge is to measure the persistent spreads of a massive number of flows without incurring too much memory overhead as such measurement may be performed at the line speed by network processors with fast but small on-chip memory. We propose a highly compact Virtual Intersection HyperLogLog (VI-HLL) architecture for this purpose. It achieves far better memory efficiency than the best prior work of V-Bitmap, and in the meantime drastically extends the measurement range. Theoretical analysis and extensive experiments demonstrate that VI-HLL provides good measurement accuracy even in very tight memory space of less than 1 bit per flow.
Wealth Destruction Effects of Annual Management Forecasts

Exploiting staggered exogenous shocks to management guidance, I provide evidence that the practice of providing numerical annual earnings forecasts induces managerial short-termism and results in greater firm opacity. Specifically, I find that firms cut long-term investments in an attempt to meet earnings target set by their own forecasts. In addition, numerical annual forecasts lead to a reduction in analyst coverage and a deterioration in stock market liquidity. These adverse consequences manifest in a loss of shareholder value and a gradual decline in firm growth. The findings are robust to controlling for alternative explanations and a battery of falsification tests. Collectively, the evidence casts doubt on the desirability of numerical annual earnings guidance as a value-enhancing corporate practice.
Mill’s radical end of laissez-faire: A review essay of the political economy of progress: John Stuart Mill and modern radicalism

Can John Stuart Mill’s radicalism achieve liberal egalitarian ends? Joseph Persky’s The Political Economy of Progress is a provocative and compelling discussion of Mill’s economic thought. It is also a defense of radical political economy. Providing valuable historical context, Persky traces Mill’s intellectual journey as an outspoken proponent of laissez-faire to a cautious supporter of co-operative socialism. I propose two problems with Persky’s optimistic take on radical social reform. First, demands for substantive equality have led past radicals to endorse exclusionary nationalist and eugenics policies. It pushes some contemporary radicals towards illiberal interventions into intimate social life. Second, the radical critique of capitalism relies on an account of profit that neglects the epistemic function of private-property markets. Once this is acknowledged, capitalism retains some progressive credentials against radical alternatives.
Linking Mastery Across the Life Course to Mobility Device Use in Later Life

Objectives Mastery in older ages is shaped by earlier-life experiences. Prior research has demonstrated that mastery is associated with health-promoting behaviors; however, little research has examined whether mastery histories influence health behaviors such as mobility device use in later life. Method Using 25 years of data from the Americans' Changing Lives Survey (N = 1,427), this research explores whether different trajectories of life course mastery influence the odds that an older adult will use a mobility device when experiencing functional impairment. We used growth mixture models with a distal outcome and examined the relationship between functional limitations and mobility device use as it varies across latent classes of life course mastery, controlling for social and health factors. Results The odds of device use in the face of functional limitations were significantly higher among those with a history of high life course mastery, relative to those with low life course mastery, all things being equal. Discussion Our findings suggest that mastery over the life course is a source of psychological human capital that is associated with health-promoting behaviors in later life among those with functional limitations.
Nutrition and High-Flow Nasal Cannula Respiratory Support in Children With Bronchiolitis.

OBJECTIVES: No guidelines are available regarding initiation of enteral nutrition in children with bronchiolitis on high-flow nasal cannula (HFNC) support. We hypothesized that the incidence of feeding-related adverse events (AEs) would not be associated with HFNC support. METHODS: This retrospective study included children ≤24 months old with bronchiolitis receiving HFNC in a PICU from September 2013 through April 2014. Data included demographics, respiratory support during feeding, and feeding-related AEs. Feeding-related AEs were extracted from nursing documentation and defined as respiratory distress or emesis. Feed route and maximum HFNC delivery were recorded in 8-hour shifts (6 am–2 pm, 2 pm–10 pm, and 10 pm–6 am). RESULTS: 70 children were included, with a median age of 5 (interquartile range [IQR] 2–10) months. HFNC delivery at feed initiation varied widely, and AEs related to feeding occurred rarely. Children were fed in 501 of 794 (63%) of nursing shifts, with AEs documented in only 29 of 501 (5.8%) of those shifts. The incidence of AEs at varying levels of respiratory support did not differ ( P = .092). Children in the “early feeding” (fed within first 2 shifts) group ( n = 22) had a shorter PICU length of stay (2.2 days [IQR 1.4–3.9] vs 3.2 [IQR 2.5–5.3], P = .006) and shorter duration of HFNC use (26.0 hours [IQR 15.8–57.0] vs 53.5 [IQR 37.0–84.8], P = .002), compared with children in the “late feeding” group ( n = 48). CONCLUSIONS: In this small, single-institution patient cohort, feeding-related AEs were rare and not related to the delivered level of respiratory support.
Child undernutrition in Pakistan : what do we know ?

Pakistan has an extraordinarily high and persistent level of child undernutrition. To effectively tackle the problem, the design of public policies and programs needs to be based on evidence. Toward this end, this paper presents a narrative review of the available empirical and qualitative literature on child undernutrition in Pakistan. It summarizes evidence for the country on, among other things, food consumption, spatial variation and trends in undernutrition rates, levels and effects of generally theorized determinants of undernutrition, and effects of various interventions on undernutrition. Based on patterns revealed in and insights gained from the cumulative evidence, the review lays out considerations and suggestions for further data collection and research, and for policy and practice.
Managerial Reliance on the Retail Shareholder Vote: Evidence from Proxy Delivery Methods

Recent studies document the increasing effectiveness of shareholder voting as a monitoring mechanism. Because both directors and the market respond to shareholder votes, management has stronger inc...
Human calprotectin affects the redox speciation of iron

We report that the metal-sequestering human host-defense protein calprotectin (CP, S100A8/S100A9 oligomer) affects the redox speciation of iron (Fe) in bacterial growth media and buffered aqueous solution. Under aerobic conditions and in the absence of an exogenous reducing agent, CP-Ser (S100A8(C42S)/S100A9(C3S) oligomer) depletes Fe from three different bacterial growth media preparations over a 48 h timeframe (T = 30 °C). The presence of the reducing agent β-mercaptoethanol accelerates this process and allows CP-Ser to deplete Fe over a ≈1 h timeframe. Fe-depletion assays performed with metal-binding-site variants of CP-Ser show that the hexahistidine (His6) site, which coordinates Fe(ii) with high affinity, is required for Fe depletion. An analysis of Fe redox speciation in buffer containing Fe(iii) citrate performed under aerobic conditions demonstrates that CP-Ser causes a time-dependent increase in the [Fe(ii)]/[Fe(iii)] ratio. Taken together, these results indicate that the hexahistidine site of CP stabilizes Fe(ii) and thereby shifts the redox equilibrium of Fe to the reduced ferrous state under aerobic conditions. We also report that the presence of bacterial metabolites affects the Fe-depleting activity of CP-Ser. Supplementation of bacterial growth media with an Fe(iii)-scavenging siderophore (enterobactin, staphyloferrin B, or desferrioxamine B) attenuates the Fe-depleting activity of CP-Ser. This result indicates that formation of Fe(iii)-siderophore complexes blocks CP-mediated reduction of Fe(iii) and hence the ability of CP to coordinate Fe(ii). In contrast, the presence of pyocyanin (PYO), a redox-cycling phenazine produced by Pseudomonas aeruginosa that reduces Fe(iii) to Fe(ii), accelerates Fe depletion by CP-Ser under aerobic conditions. These findings indicate that the presence of microbial metabolites that contribute to metal homeostasis at the host/pathogen interface can affect the metal-sequestering function of CP.
Concurrent Channel Probing and Data Transmission in Full-duplex MIMO Systems

An essential step for achieving multiplexing gain in MIMO downlink systems is to collect accurate channel state information (CSI) from the users. Traditionally, CSIs have to be collected before any data can be transmitted. Such a sequential scheme incurs a large feedback overhead, which substantially limits the multiplexing gain especially in a network with a large number of users. In this paper, we propose a novel approach to mitigate the feedback overhead by leveraging the recently developed Full-duplex radios. Our approach is based on the key observation that using Full-duplex radios, when the base-station (BS) is collecting CSI of one user through the uplink channel, it can use the downlink channel to simultaneously transmit data to other (non-interfering) users for which CSIs are already known. By allowing concurrent channel probing and data transmission, our scheme can potentially achieve a higher throughput compared to traditional schemes using Half-duplex radios. The new flexibility introduced by our scheme, however, also leads to fundamental challenges in achieving throughout optimal scheduling. In this paper, we make an initial effort to this important problem by considering a simplified group interference model. We develop a throughput optimal scheduling policy with complexity O((N/I)I), where N is the number of users and I is the number of user groups. To further reduce the complexity, we propose a greedy policy with complexity O(N log N) that not only achieves at least 2/3 of the optimal throughput region, but also outperforms any feasible Half-duplex solutions. We derive the throughput gain offered by Full-duplex under different system parameters and show the advantage of our algorithms through numerical studies.
A Lyapunov Approach to Stabilize Feedback Linearized Nonlinear Systems with Disturbances

Abstract This paper investigates the problem of designing stabilizing controllers for nonlinear systems perturbed with disturbances. The nonlinear systems studied are feedback linearizable to controllable linear systems (e.g. the Brunovsky Canonical Form) in the absence of perturbations and to Quasi Linear Systems otherwise. A method using Lyapunov stability approach is presented to obtain a linear state feedback controller stabilizing the Quasi Linear System and henceforth the perturbed nonlinear system. A sufficient condition based on the knowledge of the upper bound of the magnitude of the disturbance(s) gives stabilizing gains guaranteeing ultimate boundedness of the states of the original nonlinear system. The solution of an Algebraic Riccati Equation is used to generate the feedback gains. The conservatism of designing a stabilizing controller is also investigated.
Reflected Stochastic Differential Equation Models for Constrained Animal Movement

Movement for many animal species is constrained in space by barriers such as rivers, shorelines, or impassable cliffs. We develop an approach for modeling animal movement constrained in space by considering a class of constrained stochastic processes, reflected stochastic differential equations. Our approach generalizes existing methods for modeling unconstrained animal movement. We present methods for simulation and inference based on augmenting the constrained movement path with a latent unconstrained path and illustrate this augmentation with a simulation example and an analysis of telemetry data from a Steller sea lion (Eumatopias jubatus) in southeast Alaska.
Systems Engineering Laboratory Experiments at Washington University

Abstract An upper-division instructional laboratory, the Systems Engineering Laboratory, in the Department of Systems Science and Mathematics at Washington University offers five experiments for the program of the B.S. in Systems Science and Engineering. These experiments are for (1) computer control of a model train, (2) computer control of a robot (3) feedback control of a ball on a beam, (4) digital image processing on a chip, and (5) digital control signal transmission over a control network. In this short paper described are these as well as the principles to be taught in the laboratory and the knowledge and experience that the students receive in the course.
Analytical investigation and parametric study of lateral impact behavior of pressurized pipelines and influence of internal pressure

ABSTRACTThis article provides a combined computational and analytical study to investigate the lateral impact behavior of pressurized pipelines and inspect all the parameters such as the outside diameter and internal pressure and evaluate how they affect such behavior. In this study, quartic polynomial functions are applied to formulate the maximum crushing force (Fmax), maximum permanent displacement (W), and absorbed energy (E) of the pressurized pipelines during the impact problem. The effects of the diameter and pressure on Fmax, W, and E are therefore illustrated through analyzing these functions. Response surfaces are also plotted based on the generated quartic polynomial functions and the quality (accuracy) of these functions are verified through several techniques.
Numerical Drag Prediction of NASA Common Research Models Using Different Turbulence Models

Abstract This paper describes the results of 3D turbulent flow simulations to predict the drag of Wing-Body-Tail (WBT) and Wing-Body-Nacelle-Pylon (WBNP) aircraft configurations from NASA Common Research Models. These configurations were part of the 4th and 6th AIAA Drag Prediction Workshops in which CFD modelers participated worldwide. The computations are performed using CFD solver ANSYS FLUENT. The compressible Reynolds-Averaged Navier-Stokes (RANS) equations are solved using two turbulence models – the Spalart-Allmaras (SA) and SST k-ω. Drag polar and drag rise curves are obtained by performing computations at different angles of attack at a constant Mach number. Pressure distributions and flow separation analysis are presented at different angles of attack. Comparisons of computational results for WBT and WBNP models are made with the experimental data using the two turbulence models; good agreements are obtained. For WBNP, an aero-elastically deformed model of the wing is also considered at an angle of attack of 2.75°; the computations again are in reasonable agreement with the experiment. The computed WBNP results are compared with WB results for the drag increment study.
Sponsorship Disclosure and Consumer Deception: Experimental Evidence from Native Advertising in Mobile Search

An innovative large-scale field experiment studying advertising disclosure and consumer deception in mobile search.
Building Hegemony: Perón, Gramsci and Political Strategy in the Age of the Masses

The signs and symbols of authority in Peronism were deeply ambiguous from the beginning. October 17, 1945, both in myth and historiography, presents a dual and contradictory notion of authority. On the one hand, the great rally of October 17 represents the power of the masses, dirty and ill-clothed, seizing the initiative, while on the other, it also represents the authority and centrality of a single man, the leader whose imprisonment spurred those masses to action—Juan Peron. In its deeply ambiguous message about power, the image of October 17 vividly crystallizes a key dynamic of Peronism. In many ways, Peronism can be viewed as the story of the tension between popular sovereignty and the authority of the leader. Born in an explosion of popular force, Peronism sees the ultimate decline of popular sovereignty, moving, sometimes steadily, sometimes more erratically, towards an increasingly authoritarian, leader-centered model of power.
COSMOS: Coordination of High-Level Synthesis and Memory Optimization for Hardware Accelerators

Hardware accelerators are key to the efficiency and performance of system-on-chip (SoC) architectures. With high-level synthesis (HLS), designers can easily obtain several performance-cost trade-off implementations for each component of a complex hardware accelerator. However, navigating this design space in search of the Pareto-optimal implementations at the system level is a hard optimization task. We present COSMOS, an automatic methodology for the design-space exploration (DSE) of complex accelerators, that coordinates both HLS and memory optimization tools in a compositional way. First, thanks to the co-design of datapath and memory, COSMOS produces a large set of Pareto-optimal implementations for each component of the accelerator. Then, COSMOS leverages compositional design techniques to quickly converge to the desired trade-off point between cost and performance at the system level. When applied to the system-level design (SLD) of an accelerator for wide-area motion imagery (WAMI), COSMOS explores the design space as completely as an exhaustive search, but it reduces the number of invocations to the HLS tool by up to 14.6×.
Stochastic primal-dual coordinate method for regularized empirical risk minimization

We consider a generic convex optimization problem associated with regularized empirical risk minimization of linear predictors. The problem structure allows us to reformulate it as a convex-concave saddle point problem. We propose a stochastic primal-dual coordinate (SPDC) method, which alternates between maximizing over a randomly chosen dual variable and minimizing over the primal variables. An extrapolation step on the primal variables is performed to obtain accelerated convergence rate. We also develop a mini-batch version of the SPDC method which facilitates parallel computing, and an extension with weighted sampling probabilities on the dual variables, which has a better complexity than uniform sampling on unnormalized data. Both theoretically and empirically, we show that the SPDC method has comparable or better performance than several state-of-the-art optimization methods.
Effects of group II metabotropic glutamate receptor modulation on ethanol- and sucrose-seeking and consumption in the rat.

Abstract Previous studies suggest that group II metabotropic glutamate receptors (mGluR2/3) are involved in regulating ethanol-seeking and consumption. The mGluR2/3 agonist LY379268 (LY37) and selective mGluR2 positive allosteric modulator biphenyl‑indanone A (BINA) were used to investigate the relative contribution of mGlu2 and mGlu3 receptors on ethanol- and sucrose-seeking and consumption. A microinjection study was then performed to examine the role of nucleus accumbens (NAc) core mGluR2/3 on ethanol-seeking. For the systemic experiments, separate groups of male Wistar rats [LY37 (0–2.0 mg/kg); BINA (0–20 mg/kg)] were trained to complete a response requirement (RR) resulting in access to 10% ethanol or 2% sucrose (in separate groups) for a 20‑min drinking period. Animals then underwent consummatory testing (weekly drug injections with RR1) followed by appetitive testing (weekly drug injections followed by extinction session). A separate group of male Wistar rats was surgically implanted with bilateral guide cannulae directed toward the NAc core and had weekly microinjections followed by an extinction session. Systemic administration of the mGluR2/3 agonist LY37 significantly reduced ethanol- and sucrose-seeking. The same treatment also reduced sucrose consumption and body weight (24‑h post injection). Systemic administration of the selective mGluR2 PAM BINA, however, had no effect on either seeking or consumption of ethanol or sucrose. Intra-accumbens core LY37 significantly reduced ethanol-seeking. These findings suggest that systemic mGluR2/3 agonism, but not allosteric modulation of mGluR2, reduces reinforcer-seeking. In particular, NAc core group II mGluR may be involved in regulating ethanol-seeking.
A parsimonious neutral model suggests Neanderthal replacement was determined by migration and random species drift

Most hypotheses in the heated debate about the Neanderthals’ replacement by modern humans highlight the role of environmental pressures or attribute the Neanderthals’ demise to competition with modern humans, who occupied the same ecological niche. The latter assume that modern humans benefited from some selective advantage over Neanderthals, which led to the their extinction. Here we show that a scenario of migration and selectively neutral species drift predicts the Neanderthals’ replacement. Our model offers a parsimonious alternative to those that invoke external factors or selective advantage, and represents a null hypothesis for assessing such alternatives. For a wide range of parameters, this hypothesis cannot be rejected. Moreover, we suggest that although selection and environmental factors may or may not have played a role in the inter-species dynamics of Neanderthals and modern humans, the eventual replacement of the Neanderthals was determined by the repeated migration of modern humans from Africa into Eurasia. The replacement of Neanderthals by modern humans is thought to have been due to environmental factors, a selective advantage of modern humans, or both. Here, Kolodny and Feldman develop a neutral model of species drift showing that rapid Neanderthal replacement can be explained parsimoniously by simple migration dynamics.
Index Fund Entry and Financial Product Market Competition

The active money management industry is characterized by both strong competitive pressure from passive investment vehicles and high fees. This paper investigates how the introduction of low-cost in...
Multiple sources in a reverberant environment: The “cocktail party effect”

Acoustics and electromagnetics have many parallels based on similar equations describing propagation, reflection, and reverberation. This paper considers one example, the “cocktail party effect”, that describes speech comprehension in the presence of multiple background conversations. An electromagnetic equivalent is developed that may have application to describing the quality of a wireless communications link in the presence of multiple and similar background signals.
A computational study of the mechanisms of growth-driven folding patterns on shells, with application to the developing brain

Abstract We consider the mechanisms by which folds, or sulci (troughs) and gyri (crests), develop in the brain. This feature, common to many gyrencephalic species including humans, has attracted recent attention from soft matter physicists. It occurs due to inhomogeneous, and predominantly tangential, growth of the cortex, which causes circumferential compression, leading to a bifurcation of the solution path to a folded configuration. The problem can be framed as one of buckling in the regime of linearized elasticity. However, the brain is a very soft solid, which is subject to large strains due to inhomogeneous growth. As a consequence, the morphomechanics of the developing brain demonstrates an extensive post-bifurcation regime. Nonlinear elasticity studies of growth-driven brain folding have established the conditions necessary for the onset of folding, and for its progression to configurations broadly resembling gyrencephalic brains. The reference, unfolded, configurations in these treatments have a high degree of symmetry—typically, ellipsoidal. Depending on the boundary conditions, the folded configurations have symmetric or anti-symmetric patterns. However, these configurations do not approximate the actual morphology of, e.g., human brains, which display unsymmetric folding. More importantly, from a neurodevelopmental standpoint, many of the unsymmetric sulci and gyri are notably robust in their locations. Here, we initiate studies on the physical mechanisms and geometry that control the development of primary sulci and gyri. In this preliminary communication we carry out computations with idealized geometries, boundary conditions and parameters, seeking a pattern resembling one of the first folds to form: the Central Sulcus.
Changing the Police—The Impossible Dream?:

A. C. Germann, D.P.A. is Professor of Criminology, California State College at Long Beach. Dr. Germann is responsible for the development of the Police Science Program at Long Beach State College. He had served for a number of years as a member of the Los Angeles Police Department and subsequently as a member of the faculty of the School of Public Administration, Michigan State University, prior to coming to Long Beach State College in 1957. He is a coauthor of the well known Introduction to Law Enforcement, and a frequent contributor to professional journals. His present paper is adapted from a commentary prepared for the National Conference on Police-Community Relations, Western Center on Law and Poverty, Los Angeles, California, November 1970.
Differential Adaptive Stress Testing of Airborne Collision Avoidance Systems

The next-generation Airborne Collision Avoidance System (ACAS X) is currently being developed and tested to replace the Traffic Alert and Collision Avoidance System (TCAS) as the next international standard for collision avoidance. To validate the safety of the system, stress testing in simulation is one of several approaches for analyzing near mid-air collisions (NMACs). Understanding how NMACs can occur is important for characterizing risk and informingdevelopment of the system. Recently, adaptive stress testing (AST) has been proposed as a way to find the most likely path to a failure event. The simulation-based approach accelerates search by formulating stress testing as a sequential decision process then optimizing it using reinforcement learning. The approach has been successfully applied to stress test a prototype of ACAS Xin various simulated aircraft encounters. In some applications, we are not as interestedin the system's absolute performance as its performance relative to another system. Such situations arise, for example, during regression testing or when deciding whether a new system should replace an existing system. In our collision avoidance application, we are interested in finding cases where ACAS X fails but TCAS succeeds in resolving a conflict. Existing approaches do not provide an efficient means to perform this type of analysis. This paper extends the AST approach to differential analysis by searching two simulators simultaneously and maximizing the difference between their outcomes. We call this approach differential adaptive stress testing (DAST). We apply DAST to compare a prototype of ACAS X against TCAS and show examples of encounters found by the algorithm.
MEMS-tunable dielectric metasurface lens

We report a micro-electromechanically tunable metasurface doublet composed of a moving metasurface on a membrane and a stationary one. The doublet provides more than 180 diopters change in the optical power.
cisTEM, user-friendly software for single-particle image processing

We have developed new open-source software called cisTEM (computational imaging system for transmission electron microscopy) for the processing of data for high-resolution electron cryo-microscopy and single-particle averaging. cisTEM features a graphical user interface that is used to submit jobs, monitor their progress, and display results. It implements a full processing pipeline including movie processing, image defocus determination, automatic particle picking, 2D classification, ab-initio 3D map generation from random parameters, 3D classification, and high-resolution refinement and reconstruction. Some of these steps implement newly-developed algorithms; others were adapted from previously published algorithms. The software is optimized to enable processing of typical datasets (2000 micrographs, 200 k - 300 k particles) on a high-end, CPU-based workstation in half a day or less, comparable to GPU-accelerated processing. Jobs can also be scheduled on large computer clusters using flexible run profiles that can be adapted for most computing environments. cisTEM is available for download from cistem.org.
Student loan debt, educational attainment, and tenure choice

Using the Educational Longitudinal Study of 2002 (ELS 2002), a unique survey that tracks High School sophomores to young adulthood, we estimate the relationship between student loan debt, educational attainment, and tenure choice. We improve upon prior studies by matching pre-treatment characteristics through coarsened exact matching (CEM) and jointly modelling the decision to leave the parental home and tenure choice. Our analysis suggests effects are large in magnitude and robust for degree non-completers that incurred student loan debt. Non-completers that incurred student loan debt are nearly 7.8 percentage points less likely to own a home than otherwise similar bachelor degree holders.
A Unified Moisture Mode Framework for Seasonality of the Madden–Julian Oscillation

AbstractThe Madden–Julian oscillation (MJO) exhibits pronounced seasonality. While it is largely characterized by equatorially eastward propagation during the boreal winter, MJO convection undergoes marked poleward movement over the Asian monsoon region during summer, producing a significant modulation of monsoon rainfall. In classical MJO theories that seek to interpret the distinct seasonality in MJO propagation features, the role of equatorial wave dynamics has been emphasized for its eastward propagation, whereas coupling between MJO convection and the mean monsoon flow is considered essential for its northward propagation. In this study, a unified physical framework based on the moisture mode theory, is offered to explain the seasonality in MJO propagation. Moistening and drying caused by horizontal advection of the lower-tropospheric mean moisture by MJO winds, which was recently found to be critical for the eastward propagation of the winter MJO, is also shown to play a dominant role in operating t...
DOWN FEATHER STRUCTURE VARIES BETWEEN LOW‐ AND HIGH‐ALTITUDE TORRENT DUCKS (MERGANETTA ARMATA) IN THE ANDES

Abstract ∙ Feathers are one of the defining characteristics of birds and serve a critical role in thermal insulation and physical protection against the environment. Feather structure is known to vary among individuals, and it has been suggested that populations exposed to different environmental conditions may exhibit different patterns in feather structure. We examined both down and contour feathers from two populations of male Torrent Ducks ( Merganetta armata ) from Lima, Peru, including one high‐altitude population from the Chancay‐Huaral River at approximately 3500 m a.s.l. and one low‐altitude population from the Chillon River at approximately 1500 m a.s.l.. Down feather structure differed significantly between the two populations. Ducks from the high‐altitude population had longer, denser down compared with low‐altitude individuals. Contour feather structure varied greatly among individuals but showed no consistent difference between populations. These results suggest that the innermost, insulative layer of plumage (the down), may have developed in response to lower ambient temperatures at high elevations. The lack of observable differences in the contour feathers may be due to the fact that this outer plumage layer is more important as waterproofing than insulation. Resumen ∙ La estructura del plumon del Pato de los Torrentes ( Merganetta armata ) varia entre bajas y grandes altitudes en los Andes El plumaje es una caracteristica que define a las aves y cumple roles criticos en el aislamiento termico y proteccion fisica del ambiente. Se sabe que la estructura de las plumas varia entre individuos, y se ha sugerido que poblaciones expuestas a diferentes condiciones ambientales pueden exhibir diferentes patrones en la estructura de las plumas. En este estudio se examinaron tanto el plumon como las plumas de contorno de machos adultos del Pato de los Torrentes ( Merganetta armata ) de dos poblaciones, una en el rio Chancay‐Huaral a 3500 m s.n.m. y otra en el rio Chillon a 1500 m s.n.m., ubicadas en Lima, Peru. La estructura de plumon difiere significativamente entre las dos poblaciones. Los patos de la poblacion a mayor altitud presentan un plumon mas largo, y denso que sus congeneres de menor altitud. La estructura de las plumas de contorno varia ampliamente entre individuos, pero no muestra diferencias significativas entre poblaciones. Estos resultados sugieren que las diferencias entre las capas interiores de aislamiento del plumaje (plumon), pueden haberse desarrollado como respuesta en ambientes de bajas temperaturas a grandes elevaciones. En cambio, la ausencia de diferencias detectables en las plumas de contorno puede deberse al hecho de que esta capa externa es mas importante en la impermeabilizacion que en el aislamiento.
Measurement of the fine-structure constant as a test of the Standard Model

Measurements of the fine-structure constant α require methods from across subfields and are thus powerful tests of the consistency of theory and experiment in physics. Using the recoil frequency of cesium-133 atoms in a matter-wave interferometer, we recorded the most accurate measurement of the fine-structure constant to date: α = 1/137.035999046(27) at 2.0 × 10 −10 accuracy. Using multiphoton interactions (Bragg diffraction and Bloch oscillations), we demonstrate the largest phase (12 million radians) of any Ramsey-Borde interferometer and control systematic effects at a level of 0.12 part per billion. Comparison with Penning trap measurements of the electron gyromagnetic anomaly g e − 2 via the Standard Model of particle physics is now limited by the uncertainty in g e − 2; a 2.5σ tension rejects dark photons as the reason for the unexplained part of the muon’s magnetic moment at a 99% confidence level. Implications for dark-sector candidates and electron substructure may be a sign of physics beyond the Standard Model that warrants further investigation.
Spherical conic metrics and realizability of branched covers

Branched covers between Riemann surfaces are associated with certain combinatorial data, and Hurwitz existence problem asks whether given data satisfying those combinatorial constraints can be realized by some branched cover. We connect recent development in spherical conic metrics to this old problem, and give a new method of finding exceptional (unrealizable) branching data. As an application, we find new infinite sets of exceptional branched cover data on the Riemann sphere.
Are High-Quality PhD Programs at Universities Associated with More Undergraduate Students Pursuing PhD Study?

ABSTRACTUsing restricted-access Survey of Earned Doctorates data, we investigate which attributes of a doctoral institution predict the share of its undergraduate BAs that will earn a PhD. We use t...
ClusterEnG: an interactive educational web resource for clustering and visualizing high-dimensional data.

Summary Clustering is one of the most common techniques used in data analysis to discover hidden structures by grouping together data points that are similar in some measure into clusters. Although there are many programs available for performing clustering, a single web resource that provides both state-of-the-art clustering methods and interactive visualizations is lacking. ClusterEnG (acronym for Clustering Engine for Genomics) provides an interface for clustering big data and interactive visualizations including 3D views, cluster selection and zoom features. ClusterEnG also aims at educating the user about the similarities and differences between various clustering algorithms and provides clustering tutorials that demonstrate potential pitfalls of each algorithm. The web resource will be particularly useful to scientists who are not conversant with computing but want to understand the structure of their data in an intuitive manner. Availability ClusterEnG is part of a bigger project called KnowEnG (Knowledge Engine for Genomics) and is available at http://education.knoweng.org/clustereng. Contact songi@illinois.edu.
Besting the status quo: the effect of abstract versus concrete mindsets on emotional trade-off difficulty and avoidant coping behavior

Building on past emotional trade-off difficulty and construal level research, we investigate the conditions under which consumers engage in avoidant coping behavior to reduce negative emotions that arise from trading off valued attributes (e.g., quality and price). Results from three studies offer evidence that an abstract (vs. concrete) mindset systematically decreases avoidant coping behavior (e.g., the selection of a status quo option) by reducing the intensity of the negative emotion consumers experience. This effect replicates across construal level manipulations and product categories. Thus, in addition to the harmful effects of negative emotions and coping behavior on consumer choice identified in past research, we find that an abstract (vs. concrete) mindset can help consumers make better (i.e., more normative) choices. Together, these findings have implications for marketers of new or unfamiliar products as well as products that are not incumbents or category leaders (i.e., status quo options) when consumers face difficult trade-offs.
Effects of Exogenous and Endogenous Attention on Metacontrast Masking.

To efficiently use its finite resources, the visual system selects for further processing only a subset of the rich sensory information. Visual masking and spatial attention control the information transfer from visual sensory-memory to visual short-term memory. There is still a debate whether these two processes operate independently or interact, with empirical evidence supporting both arguments. However, recent studies pointed out that earlier studies showing significant interactions between common-onset masking and attention suffered from ceiling and/or floor effects. Our review of previous studies reporting metacontrast-attention interactions revealed similar artifacts. Therefore, we investigated metacontrast-attention interactions by using an experimental paradigm, in which ceiling/floor effects were avoided. We also examined whether metacontrast masking is differently influenced by endogenous and exogenous attention. We analyzed mean absolute-magnitude of response-errors and their statistical distribution. When targets are masked, our results support the hypothesis that manipulations of the levels of metacontrast and of endogenous/exogenous attention have largely independent effects. Moreover, statistical modeling of the distribution of response-errors suggests weak interactions modulating the probability of “guessing” behavior for some observers in both types of attention. Nevertheless, our data suggest that any joint effect of attention and metacontrast can be adequately explained by their independent and additive contributions.
Algorithmic polynomials

The approximate degree of a Boolean function f(x1,x2,…,xn) is the minimum degree of a real polynomial that approximates f pointwise within 1/3. Upper bounds on approximate degree have a variety of applications in learning theory, differential privacy, and algorithm design in general. Nearly all known upper bounds on approximate degree arise in an existential manner from bounds on quantum query complexity. We develop a first-principles, classical approach to the polynomial approximation of Boolean functions. We use it to give the first constructive upper bounds on the approximate degree of several fundamental problems: (i) O(n3/4−1/(4(2k−1))) for the k-element distinctness problem; (ii) O(n1−1/(k+1)) for the k-subset sum problem; (iii) O(n1−1/(k+1)) for any k-DNF or k-CNF formula; (iv) O(n3/4) for the surjectivity problem. In all cases, we obtain explicit, closed-form approximating polynomials that are unrelated to the quantum arguments from previous work. Our first three results match the bounds from quantum query complexity. Our fourth result improves polynomially on the Θ(n) quantum query complexity of the problem and refutes the conjecture by several experts that surjectivity has approximate degree Ω(n). In particular, we exhibit the first natural problem with a polynomial gap between approximate degree and quantum query complexity.
Nonfouling, Encoded Hydrogel Microparticles for Multiplex MicroRNA Profiling Directly from Formalin-Fixed, Paraffin-Embedded Tissue

MicroRNAs (miRNA) are short, noncoding RNAs that have been implicated in many diseases, including cancers. Because miRNAs are dysregulated in disease, miRNAs show promise as highly stable biomarkers. Formalin-fixed, paraffin-embedded (FFPE) tissue is a valuable sample type to assay for biomolecules because it is a convenient storage method and is often used by pathologists for histological staining. However, extracting biomolecules from FFPE tissue is challenging because of the presence of cellular and extracellular proteins, formaldehyde cross-links, and paraffin. Moreover, most protocols to measure miRNA in FFPE tissue are time-consuming and laborious. Here, we report a simple protocol to directly measure miRNA from formalin-fixed cells, FFPE tissue sections after paraffin is removed, and FFPE tissue sections using encoded hydrogel microparticles fabricated using stop flow lithography. Measurements by these particles show agreement between formalin-fixed cells and fresh cells, and measurement of FFPE tissue with paraffin is 10% less than FFPE tissue when paraffin is removed before the assay. When normal and tumor FFPE tissue are compared using this microparticle assay, we observe differential miRNA signal for oncogenic miRNAs and tumor suppressing miRNAs. This approach reduces assay times, reduces the use of hazardous chemicals to remove paraffin, and provides a sensitive, quantitative, and multiplexed measurement of miRNA in FFPE tissue.
Network optimization for unified packet and circuit switched networks

Internet traffic continues to grow relentlessly, driven largely by increasingly high resolution video content. Although studies have shown that the majority of packets processed by Internet routers are pass-through traffic, they nonetheless have to be queued and routed at every hop in current networks, which unnecessarily adds substantial delays and processing costs. Such pass-through traffic can be better circuit-switched through the underlying optical transport network by means of pre-established circuits, which is possible in a unified packet and circuit switched network. In this paper, we propose a novel convex optimization framework based on a new destination-based multicommodity flow formulation for the allocation of circuits in such unified networks. In particular, we consider two deployment settings, one based on real-time traffic monitoring, and the other relying upon history-based traffic predictions. In both cases, we formulate global network optimization objectives as concave functions that capture the fair sharing of network capacity among competing traffic flows. The convexity of our problem formulations ensures globally optimal solutions.