cssi/SciSciGPT-SciSciNet huggingface dataset:
A dynamic mechanism for allosteric activation of Aurora kinase A by activation loop phosphorylation

The transfer of phosphate groups onto proteins (protein phosphorylation) is one of the most important methods used to send signals inside cells. The enzymes that catalyze this process, called protein kinases, are themselves controlled by the phosphorylation of a flexible region called the activation loop. For many years it had been thought that the purpose of activation loop phosphorylation was to clamp the otherwise flexible activation loop in an active state that allows molecules that need to be phosphorylated to bind to the kinase. This assumption was based on static pictures of protein kinases obtained by X-ray crystallography, in which individual states are trapped and visualized in a crystal lattice. However, new methods and approaches now mean it is possible to visualize how the position of the activation loop changes as it moves in solution. By applying these techniques, Ruff et al. show that the static model is incorrect in a protein kinase called Aurora A. In this enzyme, the phosphorylated activation loop continues to switch back and forth between active and inactive states. Phosphorylation instead enhances the catalytic activity of the active state. Aurora A regulates several important steps in cell division, and plays important roles in several kinds of cancer. The discovery that activated forms of Aurora A can have different dynamic properties raises the possibility that inhibitor molecules could be designed to exploit these differences and block specific activities of Aurora A in cancer cells. To realize this goal we need to better understand how a kinase switching between active and inactive states affects the ability of inhibitors to interact with it.
Validity and reliability of contingent valuation and life satisfaction measures of welfare: An application to the value of national Olympic success

The contingent valuation method (CV) has long been used to estimate nonmarket values of environmental and other public goods and amenities. Recently, life satisfaction (LS) measures have been used to estimate nonmarket values. This article empirically compares CV and LS measures of welfare. We elicit willingness‐to‐pay (WTP) estimates for medals won by Canadian athletes and LS measures using Canadian survey data collected before and after the 2010 Winter Olympic Games. These data permit comparative analyses of reliability and validity of CV and LS measures. Both exhibit econometric reliability. CV and LS WTP estimates for medals increase after the Olympics. CV measures of WTP exhibit temporal reliability but LS measures of welfare lack temporal reliability and are significantly greater than CV measures.
T-cell primary central nervous system lymphoma: A systematic literature analysis.

e13034 Background: Primary central nervous system lymphoma (PCNSL) is a rare form of extranodal non-Hodgkin’s lymphoma confined primarily to the central nervous system. T-cell PCNSLs comprise less ...
The Reach of Bicycling in Rural, Small, and Low-Density Places

Lessons derived from the urban experience of bicycling may not be broadly supportive of bicycling in rural, small, and low-density (RSLD) places because of differences in built environment, social, and political contexts. In this study, the hypothesis that bicycling was primarily an urban activity was investigated. Binary logistic regression was used to compare the frequency of bicycling and the population characteristics of bicyclists across urban and RSLD places. Multiple operational definitions of urban–rural continua were used to examine whether the results were sensitive to how RSLD places were defined. The data for bicycling were from the 2009 National Household Travel Survey, which was designed to represent the population of the United States. Bicycling was found to be primarily, but not exclusively, an urban activity. Moreover, women and youths were more likely to bicycle in RSLD places compared with urban places. These findings suggest that an urban perspective on bicycling could limit the succes...
ENTRY DETERRENCE AND STRATEGIC ALLIANCES

Researchers have written extensively on the impact that strategic alliances between airlines have on airfare, but little is known of the market entry deterrent impact of strategic alliances. Using a structural econometric model, this paper examines the market entry deterrent impact of codesharing, a form of strategic alliance, between incumbent carriers in domestic air travel markets. We find evidence of market entry deterrence, but deterrence impact depends on the specific type of codesharing between market incumbents as well as the identity of the potential entrant. We quantify the extent to which market incumbents’ codesharing influences potential entrants market entry cost and probability of market entry.
Deadlock on the Board

We develop a dynamic model of board decision-making. We show that a board could retain a policy all directors agree is worse than an available alternative. Thus, directors may retain a CEO they agree is bad—a deadlocked board leads to an entrenched CEO. We explore how to compose boards and appoint directors to mitigate deadlock. We find that board diversity and long director tenure can exacerbate deadlock. Moreover, we rationalize why CEOs and incumbent directors have power to appoint new directors: to avoid deadlock. Our model speaks to short-termism, staggered boards, and proxy access.
Inclined porous medium convection at large Rayleigh number

High-Rayleigh-number ( ) convection in an inclined two-dimensional porous layer is investigated using direct numerical simulations (DNS) and stability and variational upper-bound analyses. When the inclination angle of the layer satisfies , DNS confirm that the flow exhibits a three-region wall-normal asymptotic structure in accord with the strictly horizontal ( ) case, except that as is increased the time-mean spacing between neighbouring interior plumes also increases substantially. Both DNS and upper-bound analysis indicate that the heat transport enhancement factor (i.e. the Nusselt number) with a -dependent prefactor . When , however, where independently of , the columnar flow structure is completely broken down: the flow transitions to a large-scale travelling-wave convective roll state, and the heat transport is significantly reduced. To better understand the physics of inclined porous medium convection at large and modest inclination angles, a spatial Floquet analysis is performed, yielding predictions of the linear stability of numerically computed, fully nonlinear steady convective states. The results show that there exist two types of instability when : a bulk-mode instability and a wall-mode instability, consistent with previous findings for (Wen et al., J. Fluid Mech., vol. 772, 2015, pp. 197–224). The background flow induced by the inclination of the layer intensifies the bulk-mode instability during its subsequent nonlinear evolution, thereby favouring increased spacing between the interior plumes relative to that observed in convection in a horizontal porous layer.
Deterrence, Lawsuits, and Litigation Outcomes Under Court Errors

This article presents a strategic model of liability and litigation under court errors. Our framework allows for endogenous choice of level of care and endogenous likelihood of filing and disputes. We derive sufficient conditions for a unique universally divine mixed-strategy perfect Bayesian equilibrium under low court errors. In this equilibrium, some defendants choose to be grossly negligent; some cases are filed; and some lawsuits are dropped, some are resolved out of court, and some go to trial. We find that court errors in the size of the award, as well as damage caps and split awards, reduce the likelihood of trial but increase filing and reduce the deterrence effect of punitive damages. We derive conditions under which the adoption of the English rule for allocating legal costs reduces filing.
On the symmetry properties of a random passive scalar with and without boundaries, and their connection between hot and cold states

Abstract We consider the evolution of a decaying passive scalar in the presence of a Gaussian white noise fluctuating linear shear flow known as the Majda Model. We focus on deterministic initial data and establish the short, intermediate, and long time symmetry properties of the evolving point wise probability measure (PDF) for the random passive scalar. We identify, for the cases of both point source and line source initial data, regions in the x–yplane outside of which the PDF skewness is sign definite for all time, while inside these regions we observe multiple sign changes corresponding to exchanges in symmetry between hot and cold leaning states using exact representation formula for the PDF at the origin, and away from the origin, using numerical evaluation of the exact available Mehler kernel formulae for the scalar’s statistical moments. A new, rapidly convergent Monte-Carlo method is developed, dubbed Direct Monte-Carlo (DMC), using the available random Green’s functions which allows for the fast construction of the PDF for single point statistics, as well as multi-point statistics including spatially integrated quantities natural for full Monte-Carlo simulations of the underlying stochastic differential equations (FMC). This new method demonstrates the full evolution of the PDF from short times, to its long time, limiting and collapsing universal distribution at arbitrary points in the plane. Further, this method provides a strong benchmark for FMC and we document numbers of field realization criteria for the FMC to faithfully compute this complete dynamics. Armed with this benchmark, we apply the FMC to a channel with a no-flux boundary condition enforced on parallel planes and observe a dramatically different long time state resulting from the existence of the wall. In particular, the channel case collapsing invariant measure has negative skewness, with random states leaning heavily towards the hot state, in stark contrast to free space, where the limiting skewness is positive, with its states leaning heavily towards the cold state.
The route and timing of hydrogen sulfide therapy critically impacts intestinal recovery following ischemia and reperfusion injury.

Abstract Purpose Hydrogen sulfide (H 2 S) has many beneficial properties and may serve as a novel treatment in patients suffering from intestinal ischemia–reperfusion injury (I/R). The purpose of this study was to examine the method of delivery and timing of administration of H 2 S for intestinal therapy during ischemic injury. We hypothesized that 1) route of administration of hydrogen sulfide would impact intestinal recovery following acute mesenteric ischemia and 2) preischemic H 2 S conditioning using the optimal mode of administration as determined above would provide superior protection compared to postischemic application. Methods Male C57BL/6J mice underwent intestinal ischemia by temporary occlusion of the superior mesenteric artery. Following ischemia, animals were treated according to one of the following (N=6 per group): intraperitoneal or intravenous injection of GYY4137 (H 2 S-releasing donor, 50mg/kg in PBS), vehicle, inhalation of oxygen only, inhalation of 80ppm hydrogen sulfide gas. Following 24-h recovery, perfusion was assessed via laser Doppler imaging, and animals were euthanized. Perfusion and histology data were assessed, and terminal ileum samples were analyzed for cytokine production following ischemia. Once the optimal route of administration was determined, preischemic conditioning with H 2 S was undertaken using that route of administration. All data were analyzed using Mann–Whitney. P-values Results Mesenteric perfusion following intestinal I/R was superior in mice treated with intraperitoneal (IP) GYY4137 (IP vehicle: 25.6±6.0 vs. IP GYY4137: 79.7±15.1; p=0.02) or intravenous (IV) GYY4137 (IV vehicle: 36.3±5.9 vs. IV GYY4137: 100.7±34.0; p=0.03). This benefit was not observed with inhaled H 2 S gas (O2 vehicle: 66.6±11.4 vs. H 2 S gas: 81.8±6.0; p=0.31). However, histological architecture was only preserved with intraperitoneal administration of GYY4127 (IP vehicle: 3.4±0.4 vs. IP GYY4137: 2±0.3; p=0.02). Additionally, IP GYY4137 allowed for significant attenuation of inflammatory chemokine production of IL-6, IP-10 and MIP-2. We then analyzed whether there was a difference between pre- and postischemic administration of IP GYY4137. We found that preconditioning of animals with intraperitoneal GYY4137 only added minor improvements in outcomes compared to postischemic application. Conclusion Therapeutic benefits of H 2 S are superior with intraperitoneal application of an H 2 S donor compared to other administration routes. Additionally, while intraperitoneal treatment in both the pre- and postischemic period is beneficial, preischemic application of an H 2 S donor was found to be slightly better. Further studies are needed to examine long term outcomes and further mechanisms of action prior to widespread clinical application. Type of study Basic science. Level of evidence N/A
Is there a science to facilitate implementation of evidence-based practices and programs?

Funding agencies, such as National Institutes of Health and the Institute of Education Science have recognized the need to improve the uptake of empirically supported practices into everyday servic...
Plasma Medicine: A Brief Introduction

This mini review is to introduce the readers of Plasma to the field of plasma medicine. This is a multidisciplinary field of research at the intersection of physics, engineering, biology and medicine. Plasma medicine is only about two decades old, but the research community active in this emerging field has grown tremendously in the last few years. Today, research is being conducted on a number of applications including wound healing and cancer treatment. Although a lot of knowledge has been created and our understanding of the fundamental mechanisms that play important roles in the interaction between low temperature plasma and biological cells and tissues has greatly expanded, much remains to be done to get a thorough and detailed picture of all the physical and biochemical processes that enter into play.
Animal movement models for migratory individuals and groups

Animals often exhibit changes in their behavior during migration. Telemetry data provide a way to observe geographic position of animals over time, but not necessarily changes in the dynamics of the movement process. Continuous-time models allow for statistical predictions of the trajectory in the presence of measurement error and during periods when the telemetry device did not record the animal's position. However, continuous-time models capable of mimicking realistic trajectories with sufficient detail are computationally challenging to fit to large data sets and basic models lack realism in their ability to capture nonstationary dynamics. We present a unified class of animal movement models that are computationally efficient and provide a suite of approaches for accommodating nonstationarity in continuous trajectories due to migration and interactions among individuals. We show how to nest convolution models to incorporate interactions among migrating individuals to account for nonstationarity and provide inference about dynamic migratory networks. We demonstrate these approaches in two case studies involving migratory birds. Specifically, we used process convolution models with temporal deformation to account for heterogeneity in individual greater white-fronted goose migrations in Europe and Iceland and we used nested process convolutions to model dynamic migratory networks in sandhill cranes in North America. The approach we present accounts for various forms of temporal heterogeneity in animal movement and is not limited to migratory applications. Furthermore, our models rely on well-established principles for modeling dependent data and leverage modern approaches for modeling dynamic networks to help explain animal movement and social interaction.
Asymptotics of multivariate contingency tables with fixed marginals

Abstract We consider the asymptotic distribution of a cell in a 2 × ⋯ × 2 contingency table as the fixed marginal totals tend to infinity. The asymptotic order of the cell variance is derived and a useful diagnostic is given for determining whether the cell has a Poisson limit or a Gaussian limit. There are three forms of Poisson convergence. The exact form is shown to be determined by the growth rates of the two smallest marginal totals. The results are generalized to contingency tables with arbitrary sizes and are further complemented with concrete examples.
Quench dynamics across topological quantum phase transitions

We study the dynamics of systems quenched through topological quantum phase transitions and investigate the behavior of the bulk and edge excitations with various quench rates. Specifically, we consider the Haldane model and checkerboard model in slow quench processes with distinct band-touching structures leading to topology changes. The generation of bulk excitations is found to obey the power-law relation Kibble-Zurek and Landau-Zener theories predict. However, an anti-Kibble-Zurek behavior is observed in the edge excitations. The mechanism of excitation generation on edge states is revealed, which explains the anti-Kibble-Zurek behavior.
Specific oxylipins enhance vertebrate hematopoiesis via the receptor GPR132

Epoxyeicosatrienoic acids (EETs) are lipid-derived signaling molecules with cardioprotective and vasodilatory actions. We recently showed that 11,12-EET enhances hematopoietic induction and engraftment in mice and zebrafish. EETs are known to signal via G protein-coupled receptors, with evidence supporting the existence of a specific high-affinity receptor. Identification of a hematopoietic-specific EET receptor would enable genetic interrogation of EET signaling pathways, and perhaps clinical use of this molecule. We developed a bioinformatic approach to identify an EET receptor based on the expression of G protein-coupled receptors in cell lines with differential responses to EETs. We found 10 candidate EET receptors that are expressed in three EET-responsive cell lines, but not expressed in an EET-unresponsive line. Of these, only recombinant GPR132 showed EET-responsiveness in vitro, using a luminescence-based β-arrestin recruitment assay. Knockdown of zebrafish gpr132b prevented EET-induced hematopoiesis, and marrow from GPR132 knockout mice showed decreased long-term engraftment capability. In contrast to high-affinity EET receptors, GPR132 is reported to respond to additional hydroxy-fatty acids in vitro, and we found that these same hydroxy-fatty acids enhance hematopoiesis in the zebrafish. We conducted structure–activity relationship analyses using both cell culture and zebrafish assays on diverse medium-chain fatty acids. Certain oxygenated, unsaturated free fatty acids showed high activation of GPR132, whereas unoxygenated or saturated fatty acids had lower activity. Absence of the carbon-1 position carboxylic acid prevented activity, suggesting that this moiety is required for receptor activation. GPR132 responds to a select panel of oxygenated polyunsaturated fatty acids to enhance both embryonic and adult hematopoiesis.
Nested Stochastic Valuation of Large Variable Annuity Portfolios: Monte Carlo Simulation and Synthetic Datasets

Dynamic hedging has been adopted by many insurance companies to mitigate the financial risks associated with variable annuity guarantees. To simulate the performance of dynamic hedging for variable annuity products, insurance companies rely on nested stochastic projections, which is highly computationally intensive and often prohibitive for large variable annuity portfolios. Metamodeling techniques have recently been proposed to address the computational issues. However, it is difficult for researchers to obtain real datasets from insurance companies to test metamodeling techniques and publish the results in academic journals. In this paper, we create synthetic datasets that can be used for the purpose of addressing the computational issues associated with the nested stochastic valuation of large variable annuity portfolios. The runtime used to create these synthetic datasets would be about three years if a single CPU were used. These datasets are readily available to researchers and practitioners so that they can focus on testing metamodeling techniques.
High Fidelity Semantic Shape Completion for Point Clouds Using Latent Optimization

Semantic shape completion is a challenging problem in 3D computer vision where the task is to generate a complete 3D shape using a partial 3D shape as input. We propose a learning-based approach to complete incomplete 3D shapes through generative modeling and latent manifold optimization. Our algorithm works directly on point clouds. We use an autoencoder and a GAN to learn a distribution of embeddings for point clouds of object classes. An input point cloud with missing regions is first encoded to a feature vector. The representations learnt by the GAN are then used to find the best latent vector on the manifold using a combined optimization that finds a vector in the manifold of plausible vectors that is close to the original input (both in the feature space and the output space of the decoder). Experiments show that our algorithm is capable of successfully reconstructing point clouds with large missing regions with very high fidelity without having to rely on exemplar based database retrieval.
Flat energy bands within antiphase and twin boundaries and at open edges in topological materials

A model for two-dimensional electronic, photonic, and mechanical metamaterial systems is presented, which has flat one-dimensional zero-mode energy bands and stable localized states of a topological origin confined within twin boundaries, antiphase boundaries, and at open edges. Topological origins of these flatbands are analyzed for an electronic system as a specific example, using a two-dimensional extension of the Su-Schrieffer-Heeger Hamiltonian with alternating shift of the chains. It is demonstrated that the slow group velocities of the localized flat band states are sensitively controlled by the distance between the boundaries and the propagation can be guided through designed paths of these boundaries. We also discuss how to realize this model in metamaterials.
Electrical Signatures of Corrosion and Solder Bond Failure in c-Si Solar Cells and Modules

Moisture- and temperature-activated corrosion of metal fingers, mechanical stress induced delamination, and failure of solder bonds rank among the leading failure mechanisms of solar modules. The physics of moisture ingress, diffusion, and reaction have been explored in detail, but the electrical implications of corrosion and delamination on specific front-surface grid geometry is not fully understood. In this paper, we show that the module efficiency loss due to corrosion, delamination, and solder bond failure (CDS) involves a complex interplay of voltage/current redistribution, reflected as a loss in photocurrent, as well as decrease/increase in shunt/series resistances. The analysis presented in this paper will redefine the interpretation of experimental I–V characteristic features due to degradation mechanisms, integrate a variety of scattered and counter-intuitive experimental results within a common theoretical framework, and inform CDS-resistant grid design for solar modules.
Hypertension Screening in the Follow-Up of Premature Infants

Results of hypertension screening using the Doppler technique in a group of premature infants following discharge from an intensive care nursery are reported. Systolic blood pressure (BP) was measured at follow-up in 79/99 premature infants who were cared for in the special care nursery over a 9-month period. The mean BP was 99.3 +/- 2.0 (SEM) mm Hg at a mean age of 14.7 +/- 1.3 weeks; mean age corrected for 40 weeks of gestation was 7.4 +/- 1.3 weeks. Seven infants (8.9%) with BP greater than 113 on three separate occasions were identified as hypertensive. Three of these hypertensive infants were found to have a specific etiology requiring treatment: neuroblastoma, coarctation of the aorta, and unilateral ureteropelvic junction obstruction. No difference was found between the hypertensive and normotensive infants for a variety of perinatal and neonatal factors, including the presence or duration of an umbilical arterial catheter. These data suggest that the premature infant may be at risk for the development of hypertension. In the future, neonatal follow-up programs may find hypertension screening a useful part of their evaluation.
Patient Perceptions of Surgeon Reimbursement for Rotator Cuff Repair.

Background Previous studies in the arthroplasty, spine, and shoulder and elbow literature have shown that patients perceive Medicare reimbursement to surgeons to be much higher than current reimbursement schedules. Purpose To evaluate patient perceptions of surgeon reimbursement for various rotator cuff repair (RCR) procedures. Study Design Cross-sectional study. Methods We surveyed 153 patients who presented to a single surgeon's orthopaedic sports medicine clinic between October 2016 and March 2017. Patients with a new complaint of hip or knee pain, those with a new complaint of shoulder pain, or those who had undergone shoulder surgery 1 year or more prior to their current visit were included. Patients were asked how much they thought surgeons should be reimbursed for RCR procedures, including arthroscopic repair of a simple tear and a massive tear as well as open repair of an acute tear and a chronic tear. They were also asked to estimate how much they thought surgeons were reimbursed by Medicare for these procedures. They were then given actual Medicare reimbursement rates for these procedures and asked whether they believed surgeons should be reimbursed that amount. Results For arthroscopic repair of a rotator cuff tear, patients believed that surgeons should receive a mean (±SEM) reimbursement of US$5645 ± $442. This was significantly more than their estimate of what surgeons were actually reimbursed by Medicare ($3644 ± $408; P = .001). Patients also believed that surgeons should be reimbursed more than their estimate of what surgeons were actually reimbursed for arthroscopic repair of a massive tear ($8066 ± $708 vs $4694 ± $476; P = .0001), open repair of an acute tear ($8428 ± $768 vs $4549 ± $396; P = .00001), and open repair of a chronic tear ($8902 ± $844 vs $4639 ± $438; P = .00001). Both types of patient perceptions were higher than the actual state Medicare reimbursement data for all procedures surveyed (P < .001). Conclusion Consistent with previous literature, patients perceive Medicare reimbursement for RCR to be higher than what surgeons are actually reimbursed. As the United States health care system enters a bundled care environment, price transparency is increasingly important. This study indicates a need for patient education on how their health care costs are allocated.
A Prospective Program to Reduce the Clinical Incidence of Clostridium Difficile Colitis Infection after Cystectomy

Purpose:The development of Clostridium difficile infection after cystectomy is associated with significant morbidity and mortality. We implemented a prospective screening program to identify asympt...
The Lack of Consensus of International Contouring Guidelines for the Dorsal Border of the Chest Wall Clinical Target Volume: What is the Impact on Organs at Risk and Relationships to Patterns of Recurrence in the Modern Era?

Purpose Variation exists in cooperative group recommendations for the dorsal border for the chest wall clinical target volume (CTV). We aimed to quantify the impact of this variation on doses to critical organs and examine patterns of chest wall recurrence relative to the pectoralis muscle. Methods and Materials We retrospectively assessed patterns of chest wall recurrence quantified to the recommended CTV borders for women treated between 2005 and 2017. We compared treatment plans for 5 women who were treated with left postmastectomy radiation therapy, with the chest wall contoured using varying dorsal borders for CTV: (1) Anterior pleural surface (Radiation Therapy Oncology Group), (2) anterior surface of pectoralis major (European Society for Radiotherapy and Oncology), and (3) anterior rib surface (institutional practice). Treatment plans were generated for 50 Gy in 25 fractions. Doses to organs-at-risk were compared using paired-sample t tests. Results Institutional patterns of chest wall recurrence were 64.7% skin and subcutaneous tissue, 23.5% both anterior to and between the pectoralis muscles, and 11.8% isolated to the tissue between the pectoralis major and minor. No chest wall recurrences were noted deep to pectoralis minor. When comparing the plans generated per the Radiation Therapy Oncology Group versus European Society for Radiotherapy and Oncology contouring guidelines, the mean lung V20Gy, heart mean dose, and left anterior descending artery mean dose were 33.5% versus 29.4% (P Conclusions The recommended variations in the dorsal chest wall CTV border have significant impact on doses to the heart and lungs. Although our study was limited by small numbers, our institutional patterns of recurrence would support a more anterior dorsal border for the chest wall CTV consistent with older literature.
Boosted Attention: Leveraging Human Attention for Image Captioning

Visual attention has shown usefulness in image captioning, with the goal of enabling a caption model to selectively focus on regions of interest. Existing models typically rely on top-down language information and learn attention implicitly by optimizing the captioning objectives. While somewhat effective, the learned top-down attention can fail to focus on correct regions of interest without direct supervision of attention. Inspired by the human visual system which is driven by not only the task-specific top-down signals but also the visual stimuli, we in this work propose to use both types of attention for image captioning. In particular, we highlight the complementary nature of the two types of attention and develop a model (Boosted Attention) to integrate them for image captioning. We validate the proposed approach with state-of-the-art performance across various evaluation metrics.
Measures and votes: Party performance under free list proportional representation with evidence from Ecuador

Abstract Free list proportional representation is an electoral system that gives voters as many votes as there are seats, and allows the voter to distribute them anywhere on the ballot. Computing party support under this system can be complicated, since different electors possess and use different numbers of votes. As a result, national election results and derivatives thereof (e.g. electoral volatility) may be calculated incorrectly. Using a stylized illustration, we describe obstacles to vote aggregation under the free list and develop four approaches for counting votes. The first two, “naive aggregationˮ and the “fictional voterˮ technique, have known applications. We propose the third, which we call “weighted votesˮ, to deal with missing data about the number of voters. The last, “weighted preferencesˮ, has been used intermittently, and we offer a generalization for a broad range of applications. Applying these methods to Ecuadorian elections, our results reveal biases in certain approaches and inform the question of which method to use and under which circumstances. Lastly, we make publicly available a definitive set of district- and national-level election results for Ecuador over six elections from 1998 to 2017, thereby making it possible for the case to re-enter comparative cross-national research.
Managerial ability, forecasting quality, and open-market repurchase program completion

Prior research suggests that managers often fail to complete announced open market repurchase (OMR) plans due to uncertainty in the firm’s future cash flows. Although high-ability managers should manage cash flows more effectively to complete share reacquisitions, there is little evidence to support this idea. This paper investigates whether CEOs with superior ability to efficiently manage corporate resources are associated with higher OMR completion rates. Our main findings are that OMR program completion rates increase with managerial ability and that the association is further moderated by the quality of management earnings forecasts. Cross-sectional analyses indicate that the positive associations are more pronounced in firms with higher cash flow volatility and fewer rent extraction opportunities. Our results imply that the repurchase completion rate is potentially an observable signal of managers’ broader ability to forecast and adapt to uncertain cash flows during the repurchase period.
Rising Proportion of Young Individuals With Rectal and Colon Cancer

Abstract Background Recent trends have identified increasing number of young individuals with rectal and colon cancers. These individuals, who are younger than 50 years old, in most instances would not meet screening guidelines. We aimed to report the characteristics and trend of the rising proportion of young individuals being diagnosed with rectal and colon cancers at our institutions. Patients and Methods This study included 3381 rectal and colon cancer patients from the Mayo Clinic cancer registry from 1972 to 2017 who were diagnosed with rectal or colon cancer and who were Results The percentage of patients diagnosed with rectal or colon cancer in different age categories over the years showed a rising trend for individuals aged P Conclusion Our study affirms the rising proportion of colorectal cancers found in young individuals, with a linear ongoing rise of rectal cancers in particular. This may have implications for the current screening recommendations for colorectal cancers, which are already being revised.
Phonon diffraction and dimensionality crossover in phonon-interface scattering

Thermal resistance at interfaces and grain boundaries is important in a range of fields from microelectronics to energy materials. Standard models treat interfaces as structureless even though at the nanoscale they are often better described as arrays of linear defects. Here, we examine several characteristics of heat transport that arise when considering such a structure at the interface. When heat carrying phonons scatter off linear defect arrays, diffraction of phonons occurs. Furthermore, a dimensionality crossover is observed in diffusive transport. Phonons transition from seeing a structureless planar defect when their wavelength is longer than the defect spacing, $$\lambda \gtrsim D$$ , to seeing the interface as a collection of independently scattering linear defects when $$\lambda \lesssim D$$ . By applying this theory to grain boundary strain-field scattering, we show that this dimensionality crossover can explain the frequency dependence of grain boundary scattering and transmissivity, which results in the T2 temperature dependence observed in the low-T thermal conductivity of poly/nanocrystalline materials. Grain boundaries, the interfaces between individual crystallites which together make up a material, play a fundamental role in its physical properties. The authors develop a theory to understand the physics of thermal transport, which can be strongly influenced by grain boundaries, by considering the nanoscale structure of interfaces.
A theory on the absence of spurious solutions for nonconvex and nonsmooth optimization

We study the set of continuous functions that admit no spurious local optima (i.e. local minima that are not global minima) which we term global functions. They satisfy various powerful properties for analyzing nonconvex and nonsmooth optimization problems. For instance, they satisfy a theorem akin to the fundamental uniform limit theorem in the analysis regarding continuous functions. Global functions are also endowed with useful properties regarding the composition of functions and change of variables. Using these new results, we show that a class of non-differentiable nonconvex optimization problems arising in tensor decomposition applications are global functions. This is the first result concerning nonconvex methods for nonsmooth objective functions. Our result provides a theoretical guarantee for the widely-used $\ell_1$ norm to avoid outliers in nonconvex optimization.
Imprints of primordial non-Gaussianity on gravitational wave spectrum

Although cosmic microwave background and large scale structure probe the largest scales of our Universe with ever-increasing precision, our knowledge about the smaller scales is still very limited other than the bounds on primordial black holes (PBHs). We show that the statistical properties of the small scale quantum fluctuations can be probed via the stochastic gravitational wave (GW) background, which is induced as the scalar modes reenter the horizon. We found that even if scalar curvature fluctuations have a subdominant non-Gaussian component, these non-Gaussian perturbations can source a dominant portion of the induced GWs. Moreover, the GWs sourced by non-Gaussian scalar fluctuations peak at a higher frequency and this can result in distinctive observational signatures. If the induced GW background is detected, but not the signatures arising from the non-Gaussian component, $\ensuremath{\zeta}={\ensuremath{\zeta}}_{G}+{f}_{\mathrm{NL}}{\ensuremath{\zeta}}_{G}^{2}$, this translates into bounds on ${f}_{\mathrm{NL}}$ depending on the amplitude and the width of the GW signal. The results are independent of the fact that whether PBHs are dark matter or a completely negligible part of the current energy density.
Endoscopic control of polyp burden and expansion of surveillance intervals in serrated polyposis syndrome.

Background and Aims Serrated polyposis syndrome (SPS) increases colorectal cancer risk. We describe the numbers of colonoscopies and polypectomies performed to achieve and maintain low polyp burdens, and the feasibility of expanding surveillance intervals in patients who achieve endoscopic control. Methods We retrospectively evaluated a prospectively collected database on 115 patients with SPS undergoing surveillance at Indiana University Hospital between June 2005 and May 2018. The endoscopist provided surveillance interval recommendations based on polyp burden. Endoscopic control was considered successful if surveillance examinations exhibited fewer polyps and if no or only an occasional polyp ≥1 cm in size was present at follow-up. Initial control was designated as the clearing phase and the maintenance phase was surveillance after control was established. Results In total, 87 patients (75.7%) achieved endoscopic control, with some others currently in the clearing phase. Achieving control required a mean of 2.84 colonoscopies (including the baseline) over 20.4 months and a mean total of 27.9 polyp resections. After establishing control, 71 patients were recommended to receive ≥24-month follow-up. Of those, 60 patients (69.0% of patients with initial control) continued surveillance at our center. The mean interval between colonoscopies during maintenance was 19.3 months with 6.74 mean polypectomies per procedure on polyps primarily Conclusion Most patients achieved control of polyp burden with 2 to 3 colonoscopies over 1 to 2 years. After reaching control, 60 patients returned at intervals up to 24 months with no incident cancers and no surgeries required. Expansion of surveillance intervals to 24 months is effective and safe for many patients with SPS who reach control of polyp burden.
Optimal Resource Allocation over Networks via Lottery-Based Mechanisms

We show that, in a resource allocation problem, the ex ante aggregate utility of players with cumulative-prospect-theoretic preferences can be increased over deterministic allocations by implementing lotteries. We formulate an optimization problem, called the system problem, to find the optimal lottery allocation. The system problem exhibits a two-layer structure comprised of a permutation profile and optimal allocations given the permutation profile. For any fixed permutation profile, we provide a market-based mechanism to find the optimal allocations and prove the existence of equilibrium prices. We show that the system problem has a duality gap, in general, and that the primal problem is NP-hard. We then consider a relaxation of the system problem and derive some qualitative features of the optimal lottery structure.
Organizing principles of pulvino-cortical functional coupling in humans

The pulvinar influences communication between cortical areas. We use fMRI to characterize the functional organization of the human pulvinar and its coupling with cortex. The ventral pulvinar is sensitive to spatial position and moment-to-moment transitions in visual statistics, but also differentiates visual categories such as faces and scenes. The dorsal pulvinar is modulated by spatial attention and is sensitive to the temporal structure of visual input. Cortical areas are functionally coupled with discrete pulvinar regions. The spatial organization of this coupling reflects the functional specializations and anatomical distances between cortical areas. The ventral pulvinar is functionally coupled with occipital-temporal cortices. The dorsal pulvinar is functionally coupled with frontal, parietal, and cingulate cortices, including the attention, default mode, and human-specific tool networks. These differences mirror the principles governing cortical organization of dorsal and ventral cortical visual streams. These results provide a functional framework for how the pulvinar facilitates and regulates cortical processing. The pulvinar is involved in vision and attention, but its interactions with other brain regions are little-studied. Here, using fMRI the authors show that the human pulvinar has widespread functional coupling with cortical areas that reflects its intrinsic organization and the topographic layout of cortex.
The politics of technology bans: Industrial policy competition and green goals for the auto industry

Abstract After decades of failure to reduce greenhouse gas emissions in the transport sector, several jurisdictions have in rapid succession announced future goals to phase out sales of internal combustion engine vehicles. This article argues that these announcements are predominantly a form of political signaling in a green industrial policy competition for alternative transport technologies, notably electric vehicles. We show that such signaling games in green industrial policy are likely to emerge when market growth for alternative technologies initiates industrial policy competition, which explains the clustered timing of political signals. A country’s position in the global auto industry, however, shapes the domestic political economy for announcing a phaseout goal. Countries with aspirations to develop export-oriented EV industries seek industrial upgrading; countries with existing export-oriented auto industries promote industrial renewal to maintain international competitiveness; and importing countries pursue phaseout goals primarily for environmental reasons. Our findings suggest that industrial upgraders can induce incumbent producer countries to participate in green industrial policy competition, leading to the “trading up” of energy technology policy goals. This contrasts with classic patterns of environmental policy competition, in which advanced industrialized nations are the pacesetters.
Effects of temperature and pressure on the glass transitions of plastic bonded explosives

Abstract Various plastic bonded explosives (PBXs) contain about 5 wt.% polymer, plasticizer, and stabilizer as binder. The glass-transition temperature (Tg) determines, in part, if the binder will reduce or increase the sensitivity of the PBX to impact. A soft binder reduces the impact sensitivity; however, too soft a binder compromises the mechanical strength below that desirable for dimensional stability. Glass transitions were measured by temperature modulated DSC for PBXs before and after pressing. Pressing temperature was 90°C. The Tg of Estane, a polyester/polyurethane used in some PBX binders, was investigated. Only small changes were observed in the low temperature Tg of the soft segments but larger changes were seen in the higher temperature transitions due to the relaxation of the hard segments. The Tg of Kel F 800, a binder used in insensitive PBX 9502, was observed near ambient temperature. The PBX 9502 had a lower Tg than the neat polymer. Mechanical strength was measured for the samples of PBX 9502.
Arbitrage vs. informed short selling: Evidence from convertible bond issuers

Abstract Prior literature examines the effect of either informed or arbitrage short selling on equity markets. We test the relative importance of informed and uninformed short selling around convertible bond issues and earnings announcements for the same firms over the same time period. Convertible arbitrage short selling is associated with temporary price pressure, consistent with downward sloping demand curves. Earnings announcement short selling is consistent with informed traders who anticipate future returns. Firm-specific characteristics related to the cost of short selling similarly affect both informed and arbitrage short selling. Deal-specific characteristics capturing hedging demand also strongly determine convertible arbitrage short selling.
Thermodynamics, structure, and transport properties of the MgO–Al 2 O 3 liquid system

Seven liquids along the MgO–Al2O3 join were simulated at zero pressure in temperature (T) range 2000–6000 K using the first-principles molecular dynamics method. The simulation results show continuous changes in various physical properties with composition (molar fraction of alumina, X). They suggest that the binary mixing tends to be nearly ideal with no immiscibility along the entire join. The calculated mean coordination numbers of MgO and AlO polyhedra gradually increase with increasing X, for example, their respective values are 4.6 and 4.3 at/near the MgO end, 5.2 and 4.6 for MgAl2O4 spinel composition, and 5.5 and 4.8 at/near the alumina end. The mean O–O coordination number remains almost unchanged along the join at ≥ 12 implying a closely packed arrangement. In contrast, all other coordination types including O–Mg and O–Al change dramatically along the join. The calculated self-diffusion and viscosity coefficients vary much less with composition (by a factor of 4 or less along the entire join) than with temperature (by two orders of magnitudes over the T range considered). Their T–X variations can be well described by the respective Arrhenius equations with composition-dependent activation energies and pre-exponential parameters. While the alumina and silica components are considered to play a similar role with regard to the structural polymerization of amorphous aluminosilicates, our results show that they influence the melt transport properties very differently. Therefore, the general notion that these two oxide components play an equivalent role in multicomponent magmatic melts is not unambiguous.
Visceral Machines: Risk-Aversion in Reinforcement Learning with Intrinsic Physiological Rewards.

As people learn to navigate the world, autonomic nervous system (e.g., “ﬁght or ﬂight”) responses provide intrinsic feedback about the potential consequence of action choices (e.g., becoming nervous when close to a cliff edge or driving fast around a bend.) Physiological changes are correlated with these biological preparations to protect one-self from danger. We present a novel approach to reinforcement learning that leverages a task-independent intrinsic reward function trained on peripheral pulse measurements that are correlated with humana autonomic nervous system responses. Our hypothesis is that such reward functions can circumvent the challenges associated with sparse and skewed rewards in reinforcement learning settings and can help improve sample efﬁciency. We test this in a simulated driving environment and show that it can increase the speed of learning and reduce the number of collisions during the learning stage.