cssi/SciSciGPT-SciSciNet huggingface dataset:
Higher purpose, banking and stability

Abstract This paper provides survey evidence on higher purpose for individuals and organizations and develops a theoretical model consistent with the evidence. The survey of 1,019 individuals in the U.S. sought to learn about their commitment to and perceived value from personal and organizational higher purpose. One striking finding from the survey is that when an organization has a written statement of higher purpose, its employees tend to trust their leaders to not only be socially responsible, but also to make better business decisions, i.e. corporate governance is perceived to be better by the employees. We then develop a simple theoretical model that provides an economic rationale for this finding. In the model, an investment in higher purpose credibly signals the firm owner's ability/marginal productivity and elicits higher employee effort. When put in a banking context, the model shows that optimal contracting within a bank that pursues a higher purpose leads to higher wages for employees, higher monitoring effort and a lower probability of bank failure when the bank has more equity capital, even though the bank's capital does not affect the bank's higher purpose investment. Even absent a signaling motivation for investing in higher purpose, these results are qualitatively sustained if the bank's employees care about its purpose. Additionally, in this case, banks that invest more in higher purpose pay lower wages, elicit higher employee effort and have lower failure probabilities for any given capital ratio. Banks with higher capital ratios still pay higher wages, but the effect of capital on wages becomes weaker as the bank's higher purpose investment increases. The decrease in the exposure of the deposit insurer due to higher capital goes beyond the direct impact of capital on the bank's probability of failure.
Statistical analysis of a “cold fusion” experiment

Yagi et al recently have claimed that neutrons from the D+D reaction are emitted in Ti and in SiO2 systems in which D2 is trapped at ∼1 atm at liquid nitrogen temperature. A statistical analysis of the data shows that the background counts observed over 58 time intervals do not follow the expected Poisson distribution. This would invalidate the interpretation of the results.
Higher dose docosahexaenoic acid supplementation during pregnancy and early preterm birth: A randomised, double-blind, adaptive-design superiority trial.

Abstract Background Several meta analyses have concluded n-3 fatty acids, including docosahexaenoic acid (DHA), reduce early preterm birth (EPB, Methods This randomised, multicentre, double-blind, adaptive-design, superiority trial was conducted in three USA medical centres. Women with singleton pregnancies and 12 to 20 weeks gestation were eligible. randomization was generated in SAS® by site in blocks of 4. The planned adaptive design periodically generated allocation ratios favoring the better performing dose. Managing study personnel were blind to treatment until 30 days after the last birth. The primary outcome was EPB by dose and by enrolment DHA status (low/high). Bayesian posterior probabilities (pp) were determined for planned efficacy and safety outcomes using intention-to-treat. The study is registered with ClinicalTrials.gov (NCT02626299) and closed to enrolment. Findings Eleven hundred participants (1000 mg, n = 576; 200 mg, n = 524) were enrolled between June 8, 2016 and March 13, 2020 with the last birth September 5, 2020. 1032 (n = 540 and n = 492) were included in the primary analyses. The higher dose had a lower EPB rate [1.7% (9/540) vs 2.4% (12/492), pp=0.81] especially if participants had low DHA status at enrolment [2.0% (5/249) vs 4.1%, (9/219), pp=0.93]. Participants with high enrolment DHA status did not realize a dose effect [1000 mg: 1.4% (4/289); 200 mg: 1.1% (3/271), pp = 0.57]. The higher dose was associated with fewer serious adverse events (maternal: chorioamnionitis, premature rupture of membranes and pyelonephritis; neonatal: feeding, genitourinary and neurologic problems, all pp>0.90). Interpretation Clinicians could consider prescribing 1000 mg DHA daily during pregnancy to reduce EPB in women with low DHA status if they are able to screen for DHA. Funding The National Institutes of Health Child Health and Human Development (NICHD) funded the study. Life's DHA™-S oil, DSM Nutritional Products LLC, Switzerland provided all capsules.
A Modulation-Domain Loss for Neural-Network-Based Real-Time Speech Enhancement

We describe a modulation-domain loss function for deep-learning-based speech enhancement systems. Learnable spectro-temporal receptive fields (STRFs) were adapted to optimize for a speaker identification task. The learned STRFs were then used to calculate a weighted mean-squared error (MSE) in the modulation domain for training a speech enhancement system. Experiments showed that adding the modulation-domain MSE to the MSE in the spectro-temporal domain substantially improved the objective prediction of speech quality and intelligibility for real-time speech enhancement systems without incurring additional computation during inference.
Re-absorption and nonradiative energy transfer in vibronic laser gain media

Fe:ZnSe and other transition metals have broad upper and lower energy manifolds that give rise to broad absorption and fluorescence bands in the mid-infrared spectral region. Energy transfer between Fe2 + ions via re-absorption of fluorescence (due to the spectral overlap of these bands) and phonon-assisted energy transfer (due to the lattice dynamics of ZnSe) becomes more probable with increasing Fe2 + concentration. Here, we treat these processes as additional terms in the rate equations that govern the spontaneous decay of the Fe2 + ion. This treatment gives insight into anomalous behavior seen in the thermal lifetime of the Fe:ZnSe system. We also apply the model to other transition metal-doped II–VI materials.
Vacuum chamber pressure effects on thrust measurements of low Reynolds number nozzles

Tests were conducted to investigate the effect of vacuum facility pressure on the performance of small thruster nozzles. Thrust measurements of two converging-diverging nozzles with an area ratio of 140 and an orifice plate flowing unheated nitrogen and hydrogen were taken over a wide range of vacuum facility pressures and nozzle throat Reynolds numbers. In the Reynolds number range of 2200 to 12,000 there was no discernable viscous effect on thrust below an ambient to total pressure ratio of 1000. In nearly all cases, flow separation occurred at a pressure ratio of about 1000. This was the upper limit for obtaining an accurate thrust measurement for a conical nozzle with an area ratio of 140.
Clubs, Coase, and the role of government

As Ronald Coase and others have shown, deducing the appropriate role of the government in the economy requires a comparative institutions approach. Trying to generalize from oversimplified specifications regarding transaction costs, according to whether exclusion is possible or not, is a futile exercise. An alternative to the Ostrom matrix is to distinguish private, club, and collective consumption goods according to their technical characteristics, specifically their degree of congestabiilty. The other box of the Ostrom matrix, “common pool” resources, can also be usefully analyzed from a club perspective. Spillover goods are spatial clubs. Lastly, a version of the Coase theorem is offered, which provides the foundation of comparative institutional analysis. JEL: H4
The Implicit Bias for Adaptive Optimization Algorithms on Homogeneous Neural Networks

Despite their overwhelming capacity to overfit, deep neural networks trained by specific optimization algorithms tend to generalize well to unseen data. Recently, researchers explained it by investigating the implicit regularization effect of optimization algorithms. A remarkable progress is the work (Lyu&Li, 2019), which proves gradient descent (GD) maximizes the margin of homogeneous deep neural networks. Except GD, adaptive algorithms such as AdaGrad, RMSProp and Adam are popular owing to their rapid training process. However, theoretical guarantee for the generalization of adaptive optimization algorithms is still lacking. In this paper, we study the implicit regularization of adaptive optimization algorithms when they are optimizing the logistic loss on homogeneous deep neural networks. We prove that adaptive algorithms that adopt exponential moving average strategy in conditioner (such as Adam and RMSProp) can maximize the margin of the neural network, while AdaGrad that directly sums historical squared gradients in conditioner can not. It indicates superiority on generalization of exponential moving average strategy in the design of the conditioner. Technically, we provide a unified framework to analyze convergent direction of adaptive optimization algorithms by constructing novel adaptive gradient flow and surrogate margin. Our experiments can well support the theoretical findings on convergent direction of adaptive optimization algorithms.
Representation Matters: Offline Pretraining for Sequential Decision Making

The recent success of supervised learning methods on ever larger offline datasets has spurred interest in the reinforcement learning (RL) field to investigate whether the same paradigms can be translated to RL algorithms. This research area, known as offline RL, has largely focused on offline policy optimization, aiming to find a return-maximizing policy exclusively from offline data. In this paper, we consider a slightly different approach to incorporating offline data into sequential decision-making. We aim to answer the question, what unsupervised objectives applied to offline datasets are able to learn state representations which elevate performance on downstream tasks, whether those downstream tasks be online RL, imitation learning from expert demonstrations, or even offline policy optimization based on the same offline dataset? Through a variety of experiments utilizing standard offline RL datasets, we find that the use of pretraining with unsupervised learning objectives can dramatically improve the performance of policy learning algorithms that otherwise yield mediocre performance on their own. Extensive ablations further provide insights into what components of these unsupervised objectives -- e.g., reward prediction, continuous or discrete representations, pretraining or finetuning -- are most important and in which settings.
Electromyography Recordings Detect Muscle Activity Before Observable Contractions in Acute Stroke Care

Abstract Objective To evaluate muscle activity in the arms of adult stroke survivors with limited or no arm movement during acute care. Design Prospective observational study. Setting Acute care regional stroke center. Participants We recruited adults (N=21) who had a stroke within the previous 5 days who were admitted to a level 1 trauma hospital and had a National Institutes of Health Stroke Scale score >1 for arm function at the time of recruitment. A total of 21 adults (13 men, 8 women) with an average age of 60±15 years were recruited an average of 3±1 days after their stroke. Eleven (7 men, 4 women; age, 56±11y) had no observable or palpable arm muscle activity (Manual Muscle Test [MMT]=0) and 10 (6 men, 4 women; age, 64±1y) had detectable activity (MMT>0). Interventions Dual mode sensors (electromyography and accelerometry) were placed on the anterior deltoid, biceps, triceps, wrist extensors, and wrist flexors of the impaired arm. Main Outcome Measures The number of muscle contractions, as well as average duration, amplitude, and co-contraction patterns were evaluated for each participant. Results Muscle contractions were observed in all 5 muscles for all participants using electromyography (EMG) recordings. Contractions were easily identified from 30 minutes of monitoring for participants with an MMT >0, but up to 3 hours of monitoring was required for participants with an MMT=0 to detect contractions in all 5 muscles during standard care. Only the wrist extensors demonstrated significantly larger amplitude contractions for participants with an MMT>0 than those with an MMT=0. Co-contraction was rare, involving less than 10% of contractions. Co-contraction of 2 muscles most commonly aligned with the flexor synergy pattern commonly observed after stroke. For participants with an MMT=0, the number of contractions and maximum amplitude were moderately correlated with MMT scores at follow-up. Conclusions Muscle activity was detected with surface EMG recordings during standard acute care, even for individuals with no observable activity by clinical examination. Wearable sensors may be useful for monitoring early muscle activity and movement after stroke.
On the Distribution of "Simple Stupid Bugs" in Unit Test Files: An Exploratory Study

A key aspect of ensuring the quality of a software system is the practice of unit testing. Through unit tests, developers verify the correctness of production source code, thereby verifying the system’s intended behavior under test. However, unit test code is subject to issues, ranging from bugs in the code to poor test case design (i.e., test smells). In this study, we compare and contrast the occurrences of a type of single-statement-bug-fix known as "simple stupid bugs" (SStuBs) in test and non-test (i.e., production) files in popular open-source Java Maven projects. Our results show that SStuBs occur more frequently in non-test files than in test files, with most fix-related code associated with assertion statements in test files. Further, most test files exhibiting SStuBs also exhibit test smells. We envision our findings enabling tool vendors to better support developers in improving the maintenance of test suites.
On the application of Chimera/unstructured hybrid grids for conjugate heat transfer

A method is presented that computes the conjugate heat transfer problem using a hybrid overset grid system. The hybrid grids for theuid and solid structure regions use Chimera overset structured grids and unstructured grids, respectively. The numerical analyses require theow® eld solution and material thermal response to be obtained simultaneously. A continuous transfer of temperature and heatux is enforced at the interface, which combines the solid structure and theuidow regions into an integral system. Numerical results are compared with analytical and experimental data for aat plate and a C3X cooled turbine cascade. A simpli® ed drum-disk system is also simulated to show the effectiveness of this hybrid grid system.
Shape Sensitivity Analysis of Flutter Response of a Laminated Wing

An approach is presented for calculating the shape sensitivity of a wing flutter response with respect to changes in geometric shape. Three methods are used to calculate the sensitivity of the flutter eigenvalue.
RNAseq studies reveal distinct transcriptional response to vitamin A deficiency in small intestine versus colon, uncovering novel vitamin A-regulated genes

Vitamin A (VA) deficiency remains prevalent in resource limited areas. Using Citrobacter rodentium infection in mice as a model for diarrheal diseases, previous reports showed reduced pathogen clearance and survival due to vitamin A deficient (VAD) status. To characterize the impact of preexisting VA deficiency on gene expression patterns in the intestines, and to discover novel target genes in VA-related biological pathways, VA deficiency in mice were induced by diet. Total mRNAs were extracted from small intestine (SI) and colon, and sequenced. Differentially Expressed Gene (DEG), Gene Ontology (GO) enrichment, and co-expression network analyses were performed. DEGs compared between VAS and VAD groups detected 49 SI and 94 colon genes. By GO information, SI DEGs were significantly enriched in categories relevant to retinoid metabolic process, molecule binding, and immune function. Three co-expression modules showed significant correlation with VA status in SI; these modules contained four known retinoic acid targets. In addition, other SI genes of interest (e.g., Mbl2, Cxcl14, and Nr0b2) in these modules were suggested as new candidate genes regulated by VA. Furthermore, our analysis showed that markers of two cell types in SI, mast cells and Tuft cells, were significantly altered by VA status. In colon, "cell division" was the only enriched category and was negatively associated with VA. Thus, these data suggested that SI and colon have distinct networks under the regulation of dietary VA, and that preexisting VA deficiency could have a significant impact on the host response to a variety of disease conditions.
Engaging the opioid epidemic head on: Improving proper disposal of unused opioid medications after surgery.

Background: Currently, in the United States, there is an epidemic of opioid abuse. While this problem is well known to the public due to significant media and political attention, patients are poorly educated on the proper handling and disposal of unused opioids. Instead, the onus has fallen on the healthcare provider to minimize the number of opioids prescribed. Study objective: To improve proper opioid disposal rates after gynecologic surgery by providing educational materials along with a disposal bag. Study design: We performed a prospective study evaluating baseline understanding of medication disposal using a questionnaire given to the patients during their preoperative visit. Subsequently, patients were provided written information on proper disposal of their medications and an activated charcoal medication disposal bag. Study patients completed a survey about disposal of their unused opioids at their last post-operative visit. The success of education and proper disposal of opioid medications were evaluated. Results: Thirty-five patients, average age of 45 (range 20-77), were enrolled, and 31 patients successfully completed both surveys. The surgeries performed included hysterectomy 23 percent (n = 7), laparoscopic excision of endometriosis 32 percent (n = 10), laparoscopic ovarian cystectomy 23 percent (n = 7), prolapse repair 3 percent (n = 1), and midurethral sling procedures 19 percent (n = 6). Chronic pelvic pain was identified in 39 percent (n = 12) of our patient population. Prior to education, 52 percent (n = 16) of patients did not dispose of their opioids. Furthermore, 71 percent (n = 22) of patients stated they had never been educated by a medical provider regarding appropriate disposal. Nineteen percent (n = 6) confirmed they have used an opioid medication prescribed to someone else. Demographic data show 65 percent (n = 20) of these patients had completed a college degree or greater. After education and being given a reliable option for medication disposal with the Deterra ® bag, 94 percent (n = 29) of patients properly disposed of their opioids after surgery, demonstrating a 45 percent (p < 0.001) increase in proper disposal. In our study alone, 491 tablets of 5mg oxycodone were properly disposed. The majority of patients, 77 percent (n = 24) used the drug disposal bag, and when queried, stated they would be willing to pay on average $7.70 (range 0-20) per bag. Without education and a simple option for disposal, 422 tablets prescribed may have been subject to inappropriate diversion. Conclusion: This study clearly shows that patient education, coupled with a reliable option for opioid disposal, is effective. We strongly encourage other surgical institutions to implement similar practices not only for our surgical patients’ safety, but also for the tens of thousands of patients who died of opioid abuse in the last year.
Variational Combinatorial Sequential Monte Carlo Methods for Bayesian Phylogenetic Inference

Bayesian phylogenetic inference is often conducted via local or sequential search over topologies and branch lengths using algorithms such as random-walk Markov chain Monte Carlo (MCMC) or Combinatorial Sequential Monte Carlo (CSMC). However, when MCMC is used for evolutionary parameter learning, convergence requires long runs with inefficient exploration of the state space. We introduce Variational Combinatorial Sequential Monte Carlo (VCSMC), a powerful framework that establishes variational sequential search to learn distributions over intricate combinatorial structures. We then develop nested CSMC, an efficient proposal distribution for CSMC and prove that nested CSMC is an exact approximation to the (intractable) locally optimal proposal. We use nested CSMC to define a second objective, VNCSMC which yields tighter lower bounds than VCSMC. We show that VCSMC and VNCSMC are computationally efficient and explore higher probability spaces than existing methods on a range of tasks.
Relative precision of the sibship and LD methods for estimating effective population size with genomics-scale datasets

Computer simulations were used to compare relative precision of 2 widely used single-sample methods for estimating effective population size (Ne)-the sibship method and the linkage disequilibrium (LD) method. Emphasis is on performance when thousands of gene loci are used, which now can easily be achieved even for nonmodel species. Results show that unless Ne is very small, if at least 500-2000 diallelic loci are used, precision of the LD method is higher than the maximum possible precision for the sibship method, which occurs when all sibling relationships have been correctly identified. Results also show that when precision is high for both methods, their estimates of Ne are highly and positively correlated, which limits additional gains in precision that might be obtained by combining information from the 2 estimators.
High-Throughput Discovery of Novel Cubic Crystal Materials Using Deep Generative Neural Networks

High-throughput screening has become one of the major strategies for the discovery of novel functional materials. However, its effectiveness is severely limited by the lack of sufficient and diverse materials in current materials repositories such as the open quantum materials database (OQMD). Recent progress in deep learning have enabled generative strategies that learn implicit chemical rules for creating hypothetical materials with new compositions and structures. However, current materials generative models have difficulty in generating structurally diverse, chemically valid, and stable materials. Here we propose CubicGAN, a generative adversarial network (GAN) based deep neural network model for large scale generative design of novel cubic materials. When trained on 375 749 ternary materials from the OQMD database, the authors show that the model is able to not only rediscover most of the currently known cubic materials but also generate hypothetical materials of new structure prototypes. A total of 506 such materials have been verified by phonon dispersion calculation. Considering the importance of cubic materials in wide applications such as solar panels, the GAN model provides a promising approach to significantly expand existing materials repositories, enabling the discovery of new functional materials via screening. The new crystal structures discovered are freely accessible at www.carolinamatdb.org.
The Gorin-Shkolnikov identity and its random tree generalization

In a recent pair of papers, Gorin and Shkolnikov (Ann Probab 46: 2287–2344, 2018) and Hariya (Electron Commun Probab 21: 6, 2016) have shown that the area under normalized Brownian excursion minus one half the integral of the square of its total local time is a centered normal random variable with variance $$\frac{1}{12}$$ . Lamarre and Shkolnikov generalized this to Brownian bridges (Lamarre and Shkolnikov in Ann Inst Henri Poincare Probab Stat 55: 1402–1438, 2019) and ask for a combinatorial interpretation. We provide a combinatorial interpretation using random forests on n vertices. In particular, we show that there is a process level generalization for a certain infinite forest model. We also show analogous results for a variety of other related models using stochastic calculus.
MFNets: data efficient all-at-once learning of multifidelity surrogates as directed networks of information sources

We present an approach for constructing a surrogate from ensembles of information sources of varying cost and accuracy. The multifidelity surrogate encodes connections between information sources as a directed acyclic graph, and is trained via gradient-based minimization of a nonlinear least squares objective. While the vast majority of state-of-the-art assumes hierarchical connections between information sources, our approach works with flexibly structured information sources that may not admit a strict hierarchy. The formulation has two advantages: (1) increased data efficiency due to parsimonious multifidelity networks that can be tailored to the application; and (2) no constraints on the training data—we can combine noisy, non-nested evaluations of the information sources. Numerical examples ranging from synthetic to physics-based computational mechanics simulations indicate the error in our approach can be orders-of-magnitude smaller, particularly in the low-data regime, than single-fidelity and hierarchical multifidelity approaches.
Attitudes towards globalization barriers and implications for voting: Evidence from Sweden

Abstract Using six waves of the Swedish National Election Studies (SNES) survey data, we investigate the determinants of attitudes towards globalization barriers (trade and immigration) and how important these attitudes are in how people vote. In line with the existing results in the literature, we find that more educated and richer voters support freer trade and more immigration. We also find that conservative voters in Sweden are more likely to prefer freer trade but higher immigration barriers. Once various economic and demographic determinants of globalization barrier preferences along with voters’ ideologies on a liberal-conservative spectrum are controlled for in the analysis of voting behavior, trade barrier preferences lose their statistical significance while attitudes towards immigration barriers remain significant. This suggests that immigration attitudes affect voting behavior through channels involving identity-driven factors that are different from the channels through which more traditional electoral issues, such as trade barriers, work. Focusing on the anti-globalization Swedish Democrats, we confirm that voters with a greater preference for barriers to immigration were more likely to switch their votes to this party from the 2014 to the 2018 election.
Maximizing Cohesion and Separation in Graph Representation Learning: A Distance-aware Negative Sampling Approach.

The objective of unsupervised graph representation learning (GRL) is to learn a low-dimensional space of node embeddings that reflect the structure of a given unlabeled graph. Existing algorithms for this task rely on negative sampling objectives that maximize the similarity in node embeddings at nearby nodes (referred to as "cohesion") by maintaining positive and negative corpus of node pairs. While positive samples are drawn from node pairs that co-occur in short random walks, conventional approaches construct negative corpus by uniformly sampling random pairs, thus ignoring valuable information about structural dissimilarity among distant node pairs (referred to as "separation"). In this paper, we present a novel Distance-aware Negative Sampling (DNS) which maximizes the separation of distant node-pairs while maximizing cohesion at nearby node-pairs by setting the negative sampling probability proportional to the pair-wise shortest distances. Our approach can be used in conjunction with any GRL algorithm and we demonstrate the efficacy of our approach over baseline negative sampling methods over downstream node classification tasks on a number of benchmark datasets and GRL algorithms. All our codes and datasets are available at \url{this https URL}.
Isospectrality and matrices with concentric circular higher rank numerical ranges

Abstract We characterize under what conditions n × n Hermitian matrices A 1 and A 2 have the property that the spectrum of cos ⁡ t A 1 + sin ⁡ t A 2 is independent of t (thus, the trigonometric pencil cos ⁡ t A 1 + sin ⁡ t A 2 is isospectral). One of the characterizations requires the first ⌈ n 2 ⌉ higher rank numerical ranges of the matrix A 1 + i A 2 to be circular disks with center 0. Finding the unitary similarity between cos ⁡ t A 1 + sin ⁡ t A 2 and, say, A 1 involves finding a solution to Lax's equation.
Root Radii and Subdivision for Polynomial Root-Finding

We depart from our approximation of 2000 of all root radii of a polynomial, which has readily extended Schonhage’s efficient algorithm of 1982 for a single root radius. We revisit this extension, advance it, based on our simple but novel idea, and yield significant practical acceleration of the known near optimal subdivision algorithms for complex and real root-finding of user’s choice. We achieve this by means of significant saving of exclusion tests and Taylor’s shifts, which are the bottleneck of subdivision root-finders. This saving relies on our novel recipes for the initialization of root-finding iterations of independent interest. We demonstrate our practical progress with numerical tests, provide extensive analysis of the resulting algorithms, and show that, like the preceding subdivision root-finders, they support near optimal Boolean complexity bounds.
HPS meets AMPS: How Soft Hair Dissolves the Firewall

We build on the observation by Hawking, Perry and Strominger that a global black hole space-time supports a large number of soft hair degrees of freedom to shed new light on the firewall argument by Almheiri, Marolf, Polchinski, and Sully. We propose that the soft hair Goldstone mode is encoded in a classical transition function that connects the asymptotic and near horizon region. The entropy carried by the soft hair is part of the black hole entropy and encoded in the outside geometry. We argue that the infalling observer automatically measures the classical value of the soft mode before reaching the horizon and that this measurement implements a code subspace projection that enables the reconstruction of interior operators. We use the soft hair dynamics to introduce an observer dependent notion of the firewall and show that for an infalling observer it recedes inwards into the black hole interior: the observer never encounters a firewall before reaching the singularity. Our results indicate that the HPS black hole soft hair plays an essential role in dissolving the AMPS firewall.
On Sizes of 1-Cross Intersecting Set Pair Systems

Let $ \{(A_{i},B_{i})\}_{i=1}^{m} $ be a set pair system. Furedi, Gyarfas, and Kiraly called it $ 1 $ -cross intersecting if $ |A_{i}\cap B_{j}| $ is $ 1 $ when $ i\neq j $ and $ 0 $ if $ i=j $ . They studied the systems and their generalizations and, in particular, considered $ m(a,b,1) $ , the maximum size of a $ 1 $ -cross intersecting set pair system in which $ |A_{i}|\leq a $ and $ |B_{i}|\leq b $ for all $ i $ . Furedi, Gyarfas, and Kiraly proved that $ m(n,n,1)\geq 5^{(n-1)/2} $ and asked whether there are upper bounds on $ m(n,n,1) $ significantly better than the classical bound $ {2n\choose n} $ of Bollobas for cross intersecting set pair systems. Answering one of their questions, Holzman proved recently that if $ a,b\geq 2 $ , then $ m(a,b,1)\leq\frac{29}{30}\binom{a+b}{a} $ . He also conjectured that the factor $ \frac{29}{30} $ in his bound can be replaced by $ \frac{5}{6} $ . Our goal is to prove this bound.
Profit margins in U.S. domestic airline routes

Abstract This paper estimates profit margins in the U.S. airline industry at the domestic route level. The dynamic estimation methodology used not only is robust to any simultaneity/endogeneity bias by construction but also results in profit margin estimates that are highly consistent with actual profit data from the U.S. airline industry. Estimated annual profit margins have an average of about 13.3%, with a range between 2.7% and 42.9% across routes. A cross-route analysis further suggests that annual profit margins increase with the market share of the largest airline serving the route, whereas they decrease with airfare. Important policy suggestions follow.
Isthmocele Endometriosis- the Relationship between Cesarean Section and Endometriosis.

Study Objective We present a unique case of diffuse peritoneal endometriosis following cesarean section, involving the cesarean scar isthmocele and associated with secondary infertility, failed embryo transfers, and progressive pelvic pain. Design Case report of endometriosis within an isthmocele membrane and concomitant peritoneal endometriosis. Setting A combined hysteroscopic and laparoscopic approach in lithotomy position. Patients or Participants A 44-year-old patient with three prior cesarean-sections and a laparoscopic appendectomy, in none of which, endometriosis was visualized. She presented with dysmenorrhea, dyspareunia, and recurrent embryo transfer failures. The progressively debilitating symptoms started 14 years ago, shortly after her last cesarean-section. MRI and ultrasound demonstrated a retroverted uterus and a prominent, thin, fluid filled, cesarean scar defect. Interventions A combined hysteroscopic and laparoscopic approach was performed. Indocyanine green dye was used to identify the bladder borders and methylene blue was added to the hysteroscopy irrigation solution to create contrast. A wide excision of the isthmocele was performed followed by a three-layer closure and excision of all apparent peritoneal lesions using the AquaBlue contrast technique (ABCt™). Measurements and Main Results In the pathological assessment, multiple foci of endometriosis were identified within the isthmocele membrane, clearly differentiated from intrauterine endometrial tissue. Additionally, all seven excised peritoneal specimens contained peritoneal endometriosis. Two weeks following the procedure, transvaginal sonographic scan confirmed thick anterior uterine wall, and the patient reported only minor discomfort with almost complete resolution of her symptoms. Conclusion This case demonstrates endometriosis within the isthmocele membrane, with concomitant symptomatic peritoneal endometriosis. We propose a laparoscopic isthmocele excision technique with three-layer reconstruction, and peritoneal endometriosis excision using methylene blue contrast. We suggest a possible link between isthmocele and endometriosis and emphasize the need for wide excision of the isthmocele margins and maintaining clean borders, given the possibility of endometriosis within the isthmocele, which might be a cause or a contributor to the tissue weakness and isthmocele formation.
Does double-blind peer review reduce bias? Evidence from a top computer science conference

Peer review is widely regarded as essential for advancing scientific research. However, reviewers may be biased by authors' prestige or other characteristics. Double-blind peer review, in which the authors' identities are masked from the reviewers, has been proposed as a way to reduce reviewer bias. Although intuitive, evidence for the effectiveness of double-blind peer review in reducing bias is limited and mixed. Here, we examine the effects of double-blind peer review on prestige bias by analyzing the peer review files of 5027 papers submitted to the International Conference on Learning Representations (ICLR), a top computer science conference that changed its reviewing policy from single-blind peer review to double-blind peer review in 2018. We find that after switching to double-blind review, the scores given to the most prestigious authors significantly decreased. However, because many of these papers were above the threshold for acceptance, the change did not affect paper acceptance decisions significantly. Nevertheless, we show that double-blind peer review may have improved the quality of the selections by limiting other (non-author-prestige) biases. Specifically, papers rejected in the single-blind format are cited more than those rejected under the double-blind format, suggesting that double-blind review better identifies poorer quality papers. Interestingly, an apparently unrelated change - the change of rating scale from 10 to 4 points - likely reduced prestige bias significantly, to an extent that affected papers' acceptance. These results provide some support for the effectiveness of double-blind review in reducing prestige bias, while opening new research directions on the impact of peer review formats.
Racial Disparities in the Use of Palliative Radiotherapy for Black Patients With Multiple Myeloma in the United States.

PURPOSE/OBJECTIVE(S) Multiple myeloma (MM) is a hematologic malignancy that disproportionately affects African Americans (AA) and has a natural history that is often characterized by painful osseous lesions that are amenable to palliative radiotherapy (RT). There are known racial disparities in the definitive treatment of MM and pain management in general in the AA community compared to other racial groups. We sought to determine if racial disparities also exist in use of palliative RT for MM in the United States. MATERIALS/METHODS The National Cancer Database was queried for patients 18 years and older who were diagnosed with MM from 2004-2016 and received radiation. RT dose was limited to between (and including) 4Gy to 30Gy to exclude non-standard doses, incomplete courses, and patients treated for plasmacytoma. The main independent variable under investigation was race/ethnicity, defined as non-Hispanic white (NHW), non-Hispanic black (AA), Hispanic, and other race. Outcomes of interest included receipt of palliative RT within 12 months of MM diagnosis and death within 30 days of initiation of palliative RT. Additional covariates included socioeconomic factors, underlying health, and treatment factors. Multivariable logistic regression analyses were performed to measure the associations of patient race/ethnicity with the odds receiving radiation within 12 months of diagnosis and odds of death within 30 days of receiving the first course of RT. RESULTS Of 23,728 NCDB multiple myeloma patients receiving palliative RT within 12 months of diagnosis, 15.5% of NHW patients, 14.3% of AA patients, 15.8% of Hispanic patients, and 14.4% of other racial/ethnic group patients received palliative RT. The odds of receiving RT were 13% less for AAs compared to NHWs (OR = 0.87, CI = 0.83-0.90, P < 0.0001). Of those receiving radiation, the odds of dying within 30 days of RT were 18% less for AAs compared to NHWs (OR = 0.82, 95% CI = 0.67-1.00, P = 0.046). CONCLUSION This study of the NCDB demonstrates that in addition to previously documented disparities in definitive management of MM, AA patients are also less likely to receive palliative RT within 12 months of diagnosis and at the end of life.
HTF: Homogeneous Tree Framework for Differentially-Private Release of Location Data

Mobile apps that use location data are pervasive, spanning domains such as transportation, urban planning and healthcare. Important use cases for location data rely on statistical queries, e.g., identifying hotspots where users work and travel. Such queries can be answered efficiently by building histograms. However, precise histograms can expose sensitive details about individual users. Differential privacy (DP) is a mature and widely-adopted protection model, but most approaches for DP-compliant histograms work in a data-independent fashion, leading to poor accuracy. The few proposed data-dependent techniques attempt to adjust histogram partitions based on dataset characteristics, but they do not perform well due to the addition of noise required to achieve DP. We identify density homogeneity as a main factor driving the accuracy of DP-compliant histograms, and we build a data structure that splits the space such that data density is homogeneous within each resulting partition. We show through extensive experiments on large-scale real-world data that the proposed approach achieves superior accuracy compared to existing approaches.
Occupational vs. non-occupational equestrians: Differences in demographics and injury patterns.

ABSTRACT Introduction : Nineteen million people participate in horseback riding activities in the US, and the horse industry employs more than 460,000 full-time workers. Emergency department data suggest young female amateurs and male professionals are most at risk of death from horse-related injuries. However, there has been no investigation into factors that may increase severe injury and mortality risk in these populations. This study investigates demographics and injury pattern differences between occupational and non-occupational horse-related injuries in the US. Methods : The 2017 American College of Surgeons National Trauma Databank (ACS NTDB) was analyzed for horse-related injury using ICD 10 codes. Demographics, injury data, protective device use, and hospital procedures were analyzed. Occupational versus non-occupational injuries based on incident location (farm, sports, recreational, residential) were compared using ANOVA or Pearson's Chi-squared test. Results : Of 3,911 incidents, the most common injury mechanism was falling from the horse, but occupational and non-occupational farm injuries showed higher incidence of being struck by a horse. One-third required surgery. Upper extremity injuries were most common. Occupational injuries more often affected upper extremities of working age, minority males with commercial insurance. Non-occupational injuries most often affected heads of women at the extremes of age. Helmet use was higher in occupational sports, non-occupational sports, and non-occupational recreation injuries, and severe head injury incidence was decreased in these groups. Complications and discharge dispositions were not different across groups. Conclusions : In the largest trauma center study to date, we have shown equine-related trauma to be common and affect a predictable demographic that may permit injury prevention initiatives. Helmets may reduce severe head injury, but the efficacy of protective clothing remains to be validated.
Scalable Zonotopic Under-Approximation of Backward Reachable Sets for Uncertain Linear Systems

Zonotopes are widely used for over-approximating forward reachable sets of uncertain linear systems for verification purposes. In this letter, we use zonotopes to achieve more scalable algorithms that under-approximate backward reachable sets of uncertain linear systems for control design. The main difference is that the backward reachability analysis is a two-player game and involves Minkowski difference operations, but zonotopes are not closed under such operations. We under-approximate this Minkowski difference with a zonotope, which can be obtained by solving a linear optimization problem. We further develop an efficient zonotope order reduction technique to bound the complexity of the obtained zonotopic under-approximations. The proposed approach is evaluated against existing approaches using randomly generated instances and illustrated with several examples.
Experimental violation of the Leggett-Garg inequality using the polarization of classical light

In contrast to Bell's inequalities, which test the correlations between multiple spatially separated systems, the Leggett-Garg inequalities test the temporal correlations between measurements of a single system. We experimentally demonstrate the violation of the Leggett-Garg inequality in a classical optical system using only the polarization degree of freedom of a laser beam. Our results show maximal violations of the Leggett-Garg inequality.
Progress toward steady-state high-efficiency vircators

The resonance at which high-efficiency operation of virtual cathode oscillators is obtained occurs when the beam frequency equals the reflex frequency to within 2%. This tolerance limit in the frequency ratio implies that cathode closure in the anode-cathode gap is not acceptable. The authors have developed and tested a 6-cm2 cathode that will operate longer than 1 microsecond(s) at 300 A/cm2 without significant closure. As yet, the full-scale (>80 cm2) cathode has not worked quite as well. In many tests, the cathode will operate in the emission-limited temperature/field (T/F) mode for approximately 300 ns, and then transition into explosive emission with a relatively slow ($OM0.5 cm/microsecond(s) ) closure rate. The current density was 45 to 90 A/cm2. High-power rf-emission tests have not been run under conditions where the diode stays open and in resonance for the duration of the rf pulse at a current density of 250 A/cm2, which is required for 3-GHz operation; that test remains the focus of continuing research. Long (600-ns) duration rf pulses have been obtained at low power. The data base on microwave generation at lower power also has been extended and has shown that high-efficiency resonances will occur when a multiple of the reflex frequency equals the beam frequency. This allows greater flexibility in the design and scaling of microwave device.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Equivariant elliptic cohomology, gauged sigma models, and discrete torsion

For $G$ a finite group, we show that functions on fields for the 2-dimensional supersymmetric sigma model with background $G$-symmetry determine cocycles for complex analytic $G$-equivariant elliptic cohomology. Similar structures in supersymmetric mechanics determine cocycles for equivariant K-theory with complex coefficients. The path integral for gauge theory with a finite group constructs wrong-way maps associated to group homomorphisms. When applied to an inclusion of groups, we obtain the induced character formula of Hopkins, Kuhn, and Ravenel. For the homomorphism $G\to *$ we obtain Vafa's formula for gauging with discrete torsion. The image of equivariant Euler classes under gauging constructs modular form-valued invariants of representations that depend on a choice of string structure. We illustrate nontrivial dependence on the string structure for a 16-dimensional representation of the Klein 4-group.
Invertibility of adjacency matrices for random $d$-regular graphs

Let d≥3 be a fixed integer, and let A be the adjacency matrix of a random d-regular directed or undirected graph on n vertices. We show that there exists a constant d>0 such that P(A is singular in R)≤n−d, for n sufficiently large. This answers an open problem by Frieze and Vu. The key idea is to study the singularity probability over a finite field Fp. The proof combines a local central limit theorem and a large deviation estimate.