cssi/SciSciGPT-SciSciNet huggingface dataset:
Variability in stone composition and metabolic correlation between kidneys in patients with bilateral nephrolithiasis

To evaluate the clinical significance of discordant stone analyses in patients undergoing bilateral ureteroscopy. A retrospective chart review was performed for all patients undergoing stone extraction with bilateral ureteroscopy at our institution in an aim to identify patients who had bilateral stone analysis and 24-h urine chemistry data available. Stones were then classified based upon the dominant present (> 50%). Twenty-four hour urinalysis results were reviewed and statistical analysis performed comparing discordant and concordant patient populations, assessing significant differences that would potentially influence clinical management. We identified 79 patients (158 renal units) who had bilateral stones removed at the time of ureteroscopy. The majority of stones were classified as calcium oxalate (CaOx) (60.1%) followed by calcium phosphate (CaP) (27.8%), brushite (5.1%), uric acid (UA) (4.4%), and cystine (2.5%). Discrepancies in stone classifications were present 24% of the time. Evaluation of 24-h urinalysis results demonstrated that patients with CaOx:CaP stone discordance compared to CaOx:CaOx concordant stone formers were more likely to have an elevated pH (p = 0.02) and lower uric acid supersaturation (p = 0.01). Discrepancies in stone mineral content are common in patients with bilateral stone disease. A single stone analysis from one side in the setting of bilateral stone disease is insufficient for management of patients with bilateral renal stones, and may lead to mismanagement when this misrepresented information is utilized in addition to 24-h urinalysis results. At least one stone analysis should be performed from both sides during a bilateral stone extraction procedure.
Comparison of AC Motors to an Ideal Machine Part I—Conventional AC Machines

While comparison of the torque produced by the ac machines of a given topology is, today, a standard feature of the machine design process, comparison of machines from different families of machine types is less frequently undertaken. This two-part article compares the torque performance of 12 types of ac machines based on the same current density level, flux density level, and rotor dimensions. A new “tau” factor is introduced as means for a comparison of any ac machine with an “ideal” machine based upon Essen's equation.
Model Plasma Membrane Exhibits a Microemulsion in Both Leaves Providing a Foundation for "Rafts".

Abstract We consider a model lipid plasma membrane, one that describes the outer leaf as consisting of sphingomyelin, phosphatidylcholine, and cholesterol and the inner leaf of phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, and cholesterol. Their relative compositions are taken from experiment; the cholesterol freely interchanges between leaves. Fluctuations in local composition are coupled to fluctuations in the local membrane curvature, as in the Leibler-Andelman mechanism. Structure factors of components in both leaves display a peak at nonzero wavevector. This indicates that the disordered fluid membrane is characterized by structure of the corresponding wavelength. The scale is given by membrane properties: its bending modulus and its surface tension, which arises from the membrane’s connections to the cytoskeleton. From measurements on the plasma membrane, this scale is on the order of 100 nm. We find that the membrane can be divided into two different kinds of domains that differ not only in their composition but also in their curvature. The first domain in the outer, exoplasmic leaf is rich in cholesterol and sphingomyelin, whereas the inner, cytoplasmic leaf is rich in phosphatidylserine and phosphatidylcholine. The second kind of domain is rich in phosphatidylcholine in the outer leaf and in cholesterol and phosphatidylethanolamine in the inner leaf. The theory provides a tenable basis for the origin of structure in the plasma membrane and an illuminating picture of the organization of lipids therein.
Efficiently list-edge coloring multigraphs asymptotically optimally

We give polynomial time algorithms for the seminal results of Kahn [19, 20], who showed that the Goldberg-Seymour and List-Coloring conjectures for (list-)edge coloring multigraphs hold asymptotically. Kahn's arguments are based on the probabilistic method and are non-constructive. Our key insight is that we can combine sophisticated techniques due to Achlioptas, Iliopoulos and Kolmogorov [2] for the analysis of local search algorithms with correlation decay properties of the probability spaces on matchings used by Kahn in order to construct efficient edge-coloring algorithms.
The impacts of dimensionality, diffusion, and directedness on intrinsic universality in the abstract tile assembly model

In this paper we present a series of results related to mathematical models of self-assembling systems of tiles and the impacts that three diverse properties have on their dynamics. In these self-assembling systems, initially unorganized collections of tiles undergo random motion and can bind together, if they collide and enough of their incident glues match, to form assemblies. Here we greatly expand upon a series of prior results which showed that (1) the abstract Tile Assembly Model (aTAM) is intrinsically universal (FOCS 2012), and (2) the class of directed aTAM systems is not intrinsically universal (FOCS 2016). Intrinsic universality (IU) for a model (or class of systems within a model) means that there is a universal tile set which can be used to simulate an arbitrary system within that model (or class). Furthermore, the simulation must not only produce the same resultant structures, it must also maintain the full dynamics of the systems being simulated and display the same behaviors modulo a scale factor. While the FOCS 2012 result showed that the standard, two-dimensional (2D) aTAM is IU, here we show that this is also the case for the three-dimensional (3D) version. Conversely, the FOCS 2016 result showed that the class of aTAM systems which are directed (a.k.a. deterministic, or confluent) is not IU, meaning that there is no universal simulator which can simulate directed aTAM systems while itself always remaining directed, implying that nondeterminism is fundamentally required for such simulations. Here, however, we show that, in 3D, the class of directed aTAM systems is actually IU, i.e. there is a universal directed simulator for them. This implies that the constraint of tiles binding only in the plane forced the necessity of nondeterminism for the simulation of 2D directed systems. This then leads us to continue to explore the impacts of dimensionality and directedness on simulation of tile-based self-assembling systems by considering the influence of more rigid notions of dimensionality. Namely, we introduce the Planar aTAM, where tiles are not only restricted to binding in the plane, but they are also restricted to traveling within the plane, and we prove that the Planar aTAM is not IU, and prove that the class of directed systems within the Planar aTAM also is not IU. Finally, analogous to the Planar aTAM, we introduce the Spatial aTAM, its 3D counterpart, and prove that the Spatial aTAM is IU. This paper adds to a broad set of results which have been used to classify and compare the relative powers of differing models and classes of self-assembling systems, and also helps to further the understanding of the roles of dimension and nondeterminism on the dynamics of self-assembling systems. Furthermore, to prove our positive results we have not only designed, but also implemented what we believe to be the first IU tile set ever implemented and simulated in any tile assembly model, and have made it, along with a simulator which can demonstrate it, freely available.
What does forecaster disagreement tell us about the state of the economy

This article shows in a simple model that the part of uncertainty measured by forecaster disagreement rises in advance of and during recessions. Subsequently, it is tested using the Survey of Profe...
Configuration interaction approaches for solving quantum impurity models

We develop several configuration interaction approaches for characterizing the electronic structure of an adsorbate on a metal surface (at least in model form). When one can separate the adsorbate from the substrate, these methods can achieve a reasonable description of adsorbate on-site electron-electron correlation in the presence of a continuum of states. While the present paper is restricted to the Anderson impurity model, there is hope that these methods can be extended to ab initio Hamiltonians and provide insight into the structure and dynamics of molecule-metal surface interactions.
Nanometer-Scale Deformations of Berea Sandstone under Moisture-Content Variations

Sandstone mechanical stability is of key concern in projects involving injections of ${\mathrm{CO}}_{2}$ in sandstone geological reservoirs, for the purpose of long-term storage. We develop a method to measure nanometer-scale deformations of sandstones in real time. We demonstrate that Berea sandstone, when hydrated, changes dimensions with a relative deformation of the order of ${10}^{\ensuremath{-}4}$. If the moisture content increases, sandstone samples exhibit an extension and if the moisture content decreases then the samples shrink. We also discover that, immediately after exposure to water, the sandstone temporarily shrinks, just for a few seconds, after which time a slow extension begins and continues until about half of the fluid evaporates. Such shrinkage followed by an extension is also observed when the sample is exposed to acetone, mineral spirits, or vacuum oil. The results are obtained using a high-resolution nanopositioner technique and, in independent experiments, confirmed using the technique of coda wave interferometry.
Insider Threat Detection via Hierarchical Neural Temporal Point Processes

Insiders usually cause significant losses to organizations and are hard to detect. Currently, various approaches have been proposed to achieve insider threat detection based on analyzing the audit data that record information of the employee’s activity type and time. However, the existing approaches usually focus on modeling the users’ activity types but do not consider the activity time information. In this paper, we propose a hierarchical neural temporal point process model by combining the temporal point processes and recurrent neural networks for insider threat detection. Our model is capable of capturing a general nonlinear dependency over the history of all activities by the two-level structure that effectively models activity times, activity types, session durations, and session intervals information. Experimental results on two datasets demonstrate that our model outperforms the models that only consider information of the activity types or time alone.
Analysis of Worst-Case Interference in Underlay Radar-Massive MIMO Spectrum Sharing Scenarios

In this paper, we consider an underlay radar- massive MIMO spectrum sharing scenario in which massive MIMO base stations (BSs) with elevation beamforming capabilities are allowed to operate outside a circular exclusion zone centered at the radar. Modeling the locations of the massive MIMO BSs as a homogeneous Poisson point process (PPP), we derive an analytical expression for a tight upper bound on the average interference at the radar due to cellular transmissions. The challenge lies in bounding the worst-case elevation angle for each massive MIMO BS, for which we devise a novel construction based on the circumradius distribution of a typical Poisson-Voronoi (PV) cell. While these worst-case elevation angles are correlated for neighboring BSs due to the structure of the PV tessellation, it does not explicitly appear in our analysis because of our focus on the average interference. We also provide an estimate of the nominal average interference by approximating each cell as a circle with area equal to the average area of the typical cell. Using these results, we demonstrate that the gap between the two results remains approximately constant with respect to the exclusion zone radius. Our analysis reveals useful trends in average interference power, as a function of key deployment parameters such as radar/BS antenna heights, number of antenna elements per radar/BS, BS density, and exclusion zone radius.
The effects of evolutionary adaptations on spreading processes in complex networks

A common theme among previously proposed models for network epidemics is the assumption that the propagating object (e.g., a pathogen [in the context of infectious disease propagation] or a piece of information [in the context of information propagation]) is transferred across network nodes without going through any modification or evolutionary adaptations. However, in real-life spreading processes, pathogens often evolve in response to changing environments and medical interventions, and information is often modified by individuals before being forwarded. In this article, we investigate the effects of evolutionary adaptations on spreading processes in complex networks with the aim of 1) revealing the role of evolutionary adaptations on the threshold, probability, and final size of epidemics and 2) exploring the interplay between the structural properties of the network and the evolutionary adaptations of the spreading process.
Connective Bieberbach groups

This document contains a proof that Bieberbach groups with finite abelianization are not connective (an E-theoretic property) and then uses this result to provide a characterization of connectivity in the case of Bieberbach groups.
Logarithmic concavity for morphisms of matroids

Abstract Morphisms of matroids are combinatorial abstractions of linear maps and graph homomorphisms. We introduce the notion of a basis for morphisms of matroids, and show that its generating function is strongly log-concave. As a consequence, we obtain a generalization of Mason's conjecture on the f-vectors of independent subsets of matroids to arbitrary morphisms of matroids. To establish this, we define multivariate Tutte polynomials of morphisms of matroids, and show that they are Lorentzian in the sense of [6] for sufficiently small positive parameters.
New Set of Indicators to Measure Population Remoteness and Dispersion : Estimates for 100 Countries, with Detailed Analysis of Pacific Island Countries

This paper defines three new indicators that capture the remoteness of local communities within a country context and the overall scale of population dispersion and settlement sparsity across a country. The paper also exploits the World Bank’s subnational geography database to estimate the geographical scale of population dispersion and dispersion-adjusted population sparsity for 100 countries around the world. The new indicators are evaluated and explored for several Pacific Island countries, which are often characterized as being remote (in a global context) and highly dispersed. However, within each Pacific Island country, there is enormous variation in the remoteness of individual communities and the extent to which communities are clustered or dispersed from one another, and these conditions can be related to communities' socioeconomic characteristics. The results reflect this. The paper empirically contextualizes the settlement patterns evident in the Pacific Island countries within a broader global context, highlighting the extreme degree of population sparsity in the Pacific, relative to all the other countries that are assessed.
Low costs of adaptation to dietary restriction

Dietary restriction (DR) is the most successful and widespread means of extending organismal lifespan. However, the evolutionary basis of life extension under DR remains uncertain. The traditional evolutionary explanation is that when organisms experience DR, they allocate endogenous resources to survival and postpone reproduction until conditions improve. However, this life-extension strategy should be maladaptive if DR continues for multiple generations due to trade-offs between longevity and reproduction. To test this prediction, we subjected the budding yeast Saccharomyces cerevisiae to 1800 generations of evolution on restricted versus non-restricted diets. Adaptation to a non-restricted diet improved reproductive fitness by 57%, but provided a much smaller (14%) advantage on a restricted diet. By contrast, adaptation to DR resulted in an approximately 35% increase in reproductive fitness on both restricted and non-restricted diets. Importantly, the life-extending effect of DR did not decrease following long-term evolution on the restricted diet. Thus, contrary to theoretical expectations, we found no evidence that the life-extending DR response became maladaptive during multigenerational DR. Together, our results suggest that the DR response has a low cost and that this phenomenon may have evolved as part of a generalist strategy that extends beyond the benefits of postponing reproduction.
Sequential Learning of CSI for MmWave Initial Alignment

MmWave communications aim to meet the demand for higher data rates by using highly directional beams with access to larger bandwidth. An inherent challenge is acquiring channel state information (CSI) necessary for mmWave transmission. We consider the problem of adaptive and sequential learning of the CSI during the mmWave initial alignment phase of communication. We focus on the single-user with a single dominant path scenario where the problem is equivalent to acquiring an optimal beamforming vector, where ideally, the resulting beams point in the direction of the angle of arrival with the desired resolution. We extend our prior by proposing two algorithms for adaptively and sequentially selecting beamforming vectors for learning of the CSI, and that formulate a Bayesian update to account for the time-varying fading model. Numerically, we analyze the outage probability and expected spectral efficiency of our proposed algorithms and demonstrate improvements over strategies that utilize a practical hierarchical codebook.
Homoeologous gene expression and co-expression network analyses and evolutionary inference in allopolyploids

Polyploidy is a widespread phenomenon throughout eukaryotes. Due to the coexistence of duplicated genomes, polyploids offer unique challenges for estimating gene expression levels, which is essential for understanding the massive and various forms of transcriptomic responses accompanying polyploidy. Although previous studies have explored the bioinformatics of polyploid transcriptomic profiling, the causes and consequences of inaccurate quantification of transcripts from duplicated gene copies have not been addressed. Using transcriptomic data from the cotton genus (Gossypium) as an example, we present an analytical workflow to evaluate a variety of bioinformatic method choices at different stages of RNA-seq analysis, from homoeolog expression quantification to downstream analysis used to infer key phenomena of polyploid expression evolution. In general, EAGLE-RC and GSNAP-PolyCat outperform other quantification pipelines tested, and their derived expression dataset best represents the expected homoeolog expression and co-expression divergence. The performance of co-expression network analysis was less affected by homoeolog quantification than by network construction methods, where weighted networks outperformed binary networks. By examining the extent and consequences of homoeolog read ambiguity, we illuminate the potential artifacts that may affect our understanding of duplicate gene expression, including an overestimation of homoeolog co-regulation and the incorrect inference of subgenome asymmetry in network topology. Taken together, our work points to a set of reasonable practices that we hope are broadly applicable to the evolutionary exploration of polyploids.
On the thermodynamics of nonlinear single integral representations for thermoviscoelastic materials with applications to one-dimensional wave propagation

Thermodynamic theory is used to develop single integral constitutive relations for the nonlinear thermoviscoelastic response to arbitrary stress and temperature histories; the thermomechanically coupled energy equation is also obtained. The thermorheologically simple material, modified superposition and the isotropic stress power law are discussed in detail. A modified Fourier heat conduction law is employed to ensure that the propagation of thermal disturbances takes place at a finite velocity. Using the nonlinear thermoviscoelastic stress power law along with the linearized energy equation and modified Fourier law, one-dimensional wave front solutions are obtained.
The Third and Fatal Shock: How Pandemic Killed the Millennial Paradigm.

This millennium began with widespread acceptance of a governing paradigm emphasizing small government, free markets and open borders. Three crises - the 9/11 attacks, the 2008 financial crisis, and the 2020 COVID-19 pandemic - forced American policymakers to diverge from this paradigm. At the time, these divergences were described as temporary departures from normalcy. In retrospect, it would be more accurate to regard the millennial paradigm itself as the abnormality: as a model of governance designed for rare moments of calm. In the last two decades, a different paradigm has emerged. American government has become the ultimate bearer of societal risks. Repeatedly, it has adopted extraordinary measures to protect public safety and the economy. However, the American state lacks the capacity to anticipate and manage these massive risks competently. New capabilities are required, along with a new mentality about governing. Domestic politics will complicate the task of building these capabilities. This article is protected by copyright. All rights reserved.
A Reversibly Induced CRISPRi System Targeting Photosystem II in the Cyanobacterium Synechocystis sp. PCC 6803.

The cyanobacterium Synechocystis sp. PCC 6803 is used as a model organism to study photosynthesis, as it can utilize glucose as the sole carbon source to support its growth under heterotrophic conditions. CRISPR interference (CRISPRi) has been widely applied to repress the transcription of genes in a targeted manner in cyanobacteria. However, a robust and reversible induced CRISPRi system has not been explored in Synechocystis 6803 to knock down and recover the expression of a targeted gene. In this study, we built a tightly controlled chimeric promoter, PrhaBAD-RSW, in which a theophylline responsive riboswitch was integrated into a rhamnose-inducible promoter system. We applied this promoter to drive the expression of ddCpf1 (DNase-dead Cpf1 nuclease) in a CRISPRi system and chose the PSII reaction center gene psbD (D2 protein) to target for repression. psbD was specifically knocked down by over 95% of its native expression, leading to severely inhibited photosystem II activity and growth of Synechocystis 6803 under photoautotrophic conditions. Significantly, removal of the inducers rhamnose and theophylline reversed repression by CRISPRi. Expression of PsbD recovered following release of repression, coupled with increased photosystem II content and activity. This reversibly induced CRISPRi system in Synechocystis 6803 represents a new strategy for study of the biogenesis of photosynthetic complexes in cyanobacteria.
Estimation of highway maintenance marginal cost under multiple maintenance activities

This paper focuses on the estimation of highway maintenance marginal costs. Highway maintenance marginal cost has been estimated in the literature using the perpetual overlay indirect approach. This approach assumes that pavement overlay costs dominate maintenance costs and ignores other maintenance activities. This paper focuses on two questions. First, is it acceptable to ignore the less costly activities? Second, if multiple maintenance activities are to be considered, is it acceptable to ignore their interdependence? The results show that less costly maintenance activities cannot be ignored. Furthermore, if multiple activities are to be considered, their interdependence should be taken into account.
Do Anti-Poverty Programs Sway Voters? Experimental Evidence from Uganda

Abstract High-impact policies may not lead to support for the political party that introduces them. In 2008, Uganda’s government encouraged groups of youth to submit proposals to start enterprises....
Chapter 15 – Caecilians

Caecilians are wormlike amphibians that occur worldwide in the tropics, except for Madagascar and Oceania. Only 189 species are known, distributed among 35 genera and 10 families. Most caecilians are fossorial, living in moist soils usually adjacent to streams, lakes, and swamps; a few species are aquatic. Conservation status of caecilians is summarized. An up-to-date phylogeny details approximate time periods during which divergences occurred during the evolutionary history of caecilians and shows evolutionary relationships among the families as we now know them. Taxonomic accounts provide information on generic content, distribution, characteristics, and biology of each family.
Fibromyalgia: present to future.

There has been a dramatic increase in our understanding of fibromyalgia throughout the past 14 years since the publica-tion of the 1990 American College of Rheumatology classi-fication criteria. Before 1990, and for most of the 20th century, fibromyalgia was considered to be predominantly a muscle disorder; now the critical abnormality is described as "central sensitization." However, central sensitization has to have an initial genesis and nociceptive stimuli from painful foci in muscle are increasingly recognized as being relevant to the development of fibromyalgia. Clinicians also recognize an association between the initiation of fibromy-algia and chronic psychologic stressors and inflammatory disorders. It has been more difficult to understand how two such apparently diverse events could affect central pain physiology. However, some clues are emerging from the role of diverse stimuli in activating glial cells and the role of disordered cytokine networks. Some predictions about future developments in fibromyalgia are ventured based on the current state of knowledge.
A note on conditional expanders over prime fields

Abstract Let F p be a prime field of order p , and A be a set in F p with | A | ≤ p 1 ∕ 2 . In this note, we show that max { | A + A | , | f ( A , A ) | } ≳ | A | 6 5 + 4 305 , where f ( x , y ) is a non-degenerate quadratic polynomial in F p [ x , y ] . This improves a recent result given by Koh, Mojarrad, Pham, Valculescu (2018).
Player-compatible learning and player-compatible equilibrium

Abstract Player-Compatible Equilibrium (PCE) imposes cross-player restrictions on the magnitudes of the players' “trembles” onto different strategies. These restrictions capture the idea that trembles correspond to deliberate experiments by agents who are unsure of the prevailing distribution of play. PCE selects intuitive equilibria in a number of examples where trembling-hand perfect equilibrium ( Selten, 1975 ) and proper equilibrium ( Myerson, 1978 ) have no bite. We show that rational learning and weighted fictitious play imply our compatibility restrictions in a steady-state setting.
Twenty years of exceptional success: The molecular education and research consortium in undergraduate computational chemistry (MERCURY)

The MERCURY consortium, established in 2000, has contributed greatly to the scientific development of faculty and undergraduates. The MERCURY faculty peer review publication rate from 2001-2019 of 1.7 papers/faculty/year is 3.4 times the rate of physical science faculty at primarily undergraduate institutions. We have worked with over 1000 students on research projects since 2001, and 75% of our undergraduate research students have been underrepresented in chemistry, either female or students of color. Approximately half of our alumni attend graduate school for the purpose of obtaining advanced degrees in STEM fields and 2/3 are female and/or students of color. We have had more than 1600 attendees at the 18 MERCURY conferences, including 111 invited speakers, 61 of whom have been female and/or faculty of color. In this paper the research accomplishments, transformational outcomes, and scientific productivity of the MERCURY faculty are highlighted.
Merger policy in digital industries

Abstract I present a cautionary note on the proposal to tighten merger policy in the high-tech space. The discouragement effect on innovation could be significant. This is not to say that increased policy enforcement is not called for. On the contrary. My point is that it should primarily take the form of checking for abuses of dominant position, tightening consumer protection, and directly regulating dominant firms.
An EM Approach to Non-autoregressive Conditional Sequence Generation

Autoregressive (AR) models have been the dominating approach to conditional sequence generation, but are suffering from the issue of high inference latency. Non-autoregressive (NAR) models have been recently proposed to reduce the latency by generating all output tokens in parallel but could only achieve inferior accuracy compared to their autoregressive counterparts, primarily due to a difficulty in dealing with the multi-modality in sequence generation. This paper proposes a new approach that jointly optimizes both AR and NAR models in a unified Expectation-Maximization (EM) framework. In the E-step, an AR model learns to approximate the regularized posterior of the NAR model. In the M-step, the NAR model is updated on the new posterior and selects the training examples for the next AR model. This iterative process can effectively guide the system to remove the multi-modality in the output sequences. To our knowledge, this is the first EM approach to NAR sequence generation. We evaluate our method on the task of machine translation. Experimental results on benchmark data sets show that the proposed approach achieves competitive, if not better, performance with existing NAR models and significantly reduces the inference latency.
Israeli Compliance with Legal Guidelines for Targeted Killing

In December 2006 the Israeli High Court of Justice delivered its ruling in the Targeted Killing case (HCJ 769/02). The Court laid out four criteria that must be met for operations conducted as part of Israel's targeted killing policy to be performed legally, and imposed on the state two safeguards to ensure that each operation complies with these criteria. This research examines whether Israel has complied with the ruling in its post-2006 targeted killing operations. The article presents strong evidence which suggests that Israel complies with the Court's four requirements, although there is insufficient information to render a definitive conclusion regarding requirement 3, the principle of proportionality. However, the evidence also casts doubt on Israel's conformity with the two safeguards. The most significant issues revolve around Israel's implementation of and compliance with safeguard 1, the independent ex post facto investigative committee, which should review operations that cause civilian casualties. These concerns include the composition of the committee, its objectivity and independence. In addition, Israel's evolving understanding of the legal status of terrorists has significantly narrowed the jurisdiction of the committee and the HCJ's ruling more generally. These issues are exacerbated by the absence of evidence that safeguard 2, judicial oversight, has occurred.
Online Policies for Efficient Volunteer Crowdsourcing

Nonprofit crowdsourcing platforms such as food recovery organizations rely on volunteers to perform time-sensitive tasks. Thus, their success crucially depends on efficient volunteer utilization and engagement. To encourage volunteers to complete a task, platforms use nudging mechanisms to notify a subset of volunteers with the hope that at least one of them responds positively. However, since excessive notifications may reduce volunteer engagement, the platform faces a trade-off between notifying more volunteers for the current task and saving them for future ones. Motivated by these applications, we introduce the online volunteer notification problem, a generalization of online stochastic bipartite matching where tasks arrive following a known time-varying distribution over task types. Upon arrival of a task, the platform notifies a subset of volunteers with the objective of minimizing the number of missed tasks. To capture each volunteer's adverse reaction to excessive notifications, we assume that a notification triggers a random period of inactivity, during which she will ignore all notifications. However, if a volunteer is active and notified, she will perform the task with a given pair-specific match probability that captures her preference for the task. We develop two online randomized policies that achieve constant-factor guarantees which are close to the upper-bounds we establish for the performance of any online policy. Our policies as well as hardness results are parameterized by the minimum discrete hazard rate of the inter-activity time distribution. The design of our policies relies on two modifications of an ex-ante feasible solution: (1) properly scaling down the notification probability prescribed by the ex-ante solution, and (2) sparsifying that solution. Further, in collaboration with Food Rescue U.S., a volunteer-based food recovery platform, we demonstrate the effectiveness of our policies by testing them on the platform's data from various locations across the U.S.
PCH-2 collaborates with CMT-1 to proofread meiotic homolog interactions

The conserved ATPase, PCH-2/TRIP13, is required during both the spindle checkpoint and meiotic prophase. However, its specific role in regulating meiotic homolog pairing, synapsis and recombination has been enigmatic. Here, we report that this enzyme is required to proofread meiotic homolog interactions. We generated a mutant version of PCH-2 in C. elegans that binds ATP but cannot hydrolyze it: pch-2E253Q. In vitro, this mutant can bind a known substrate but is unable to remodel it. This mutation results in some non-homologous synapsis and impaired crossover assurance. Surprisingly, worms with a null mutation in PCH-2's adapter protein, CMT-1, the ortholog of p31comet, localize PCH-2 to meiotic chromosomes, exhibit non-homologous synapsis and lose crossover assurance. The similarity in phenotypes between cmt-1 and pch-2E253Q mutants suggest that PCH-2 can bind its meiotic substrates in the absence of CMT-1, in contrast to its role during the spindle checkpoint, but requires its adapter to hydrolyze ATP and remodel them.
Fly wing evolution explained by a neutral model with mutational pleiotropy.

To what extent the speed of mutational production of phenotypic variation determines the rate of long-term phenotypic evolution is a central question. Houle et al. recently addressed this question by studying the mutational variances, additive genetic variances, and macroevolution of locations of vein intersections on fly wings, reporting very slow phenotypic evolution relative to the rates of mutational input, high phylogenetic signals, and a strong, linear relationship between the mutational variance of a trait and its rate of evolution. Houle et al. found no existing model of phenotypic evolution to be consistent with all these observations, and proposed the improbable scenario of equal influence of mutational pleiotropy on all traits. Here, we demonstrate that the purported linear relationship between mutational variance and evolutionary divergence is artifactual. We further show that the data are explainable by a simple model in which the wing traits are effectively neutral at least within a range of phenotypic values but their evolutionary rates are differentially reduced because mutations affecting these traits are purged owing to their different pleiotropic effects on other traits that are under stabilizing selection. Thus, the evolutionary patterns of fly wing morphologies are explainable under the existing theoretical framework of phenotypic evolution.
Model-Based Manipulation of Linear Flexible Objects with Visual Curvature Feedback

Manipulation of deformable objects is a desired skill in making robots ubiquitous in manufacturing, service, healthcare, and security. Deformable objects are common in our daily lives, e.g., wires, clothes, bed sheets, etc., and are significantly more difficult to model than rigid objects. In this study, we investigate vision-based manipulation of linear flexible objects such as cables. We propose a geometric modeling method that is based on visual feedback to develop a general representation of the linear flexible object that is subject to gravity. The model characterizes the shape of the object by combining the curvatures on two projection planes. In this approach, we achieve tracking of the position and orientation (pose) of a cable-like object, the pose of its tip, and the pose of the selected grasp point on the object, which enables closed-loop manipulation of the object. We demonstrate the feasibility of our approach by completing the Plug Task used in the 2015 DARPA Robotics Challenge Finals, which involves unplugging a power cable from one socket and plugging it into another. Experiments show that we can successfully complete the task autonomously within 30 seconds.
Lockdown 101: Managing economic lockdowns in an epidemic

Countries worldwide have implemented lockdown measures to contain the covid-19 pandemic. After more than three months of restrictions to economic activities in many countries, the question has turned to the best ways to lift lockdowns while keeping the epidemic in check. Here I use basic economic principles to shed light on the key tradeoffs. A central message is that there is no “health vs. economics” dichotomy. Rather, some degree of lockdown is typically optimal in crisis like this, balancing its economic costs against its health benefits. Moreover, the optimal lockdown is dynamic, changes over time and eventually becomes more lenient, although the path is not necessarily monotonic.
Secure Transmission in MIMO-NOMA Networks

This letter focuses on the physical layer security over two-user multiple-input multiple-output (MIMO) non-orthogonal multiple access (NOMA) networks. A linear precoding technique is designed to ensure the confidentiality of the message of each user from its counterpart. This technique first splits the base station power between the two users and, based on that, decomposes the secure MIMO-NOMA channel into two MIMO wiretap channels, and designs the transmit covariance matrix for each channel separately. The proposed method substantially enlarges the secrecy rate compared to existing linear precoding methods and strikes a balance between performance and computation cost. Simulation results verify the effectiveness of the proposed method.
Creative destruction: Sparse activity emerges on the mammal connectome under a simulated communication strategy with collisions and redundancy.

Signal interactions in brain network communication have been little studied. We describe how nonlinear collision rules on simulated mammal brain networks can result in sparse activity dynamics char...
What Can Islamic Law Practice Tell Us about the Peaceful Resolution of International Disputes

Emilia Powell’s ambitious study of Islamic and international law successfully examines how receptive Islamic law states (ILS) are to international law's tools and forums for the peaceful resolution of disputes. This question is important for institutions such as the International Court of Justice (ICJ), specifically created to adjudicate international disputes across legal systems and cultures. Understanding receptivity can help us assess a state’s preferences in choosing among alternative forums for dispute resolution, ranging from the ICJ to ad hoc arbitration.
Does innovation explain the performance gap between privatized and private firms

Abstract In this study, using a unique firm-level survey database, I investigate innovation for privatized former state-owned enterprises (SOEs) versus originally private firms (private at inception) in 30 Eastern European and Central Asian (ECA) countries. Besides using an invention-based narrow definition of innovation, I use an imitation and adaptation-based broad definition of innovation. I find that origin of the firm matters for its innovativeness; privatized former SOEs in transition economies are less innovative than originally private firms. The results hold after controlling for important firm and country characteristics affecting firm innovativeness. Using alternative, patent-based innovation measures provides support to the main findings of the study. These findings on the relation between firm origin and innovation provide a possible explanation for the underperformance of privatized firms compared to private firms.
The dynamics of the broad-line region in NGC 3227

Archival Hubble Space Telescope (HST) observations of the Seyfert 1 nucleus of NGC 3227 obtained with the Space Telescope Imaging Spectrograph (STIS) are re-examined in order to constrain a viable photoionization model for the broad-line region (BLR). The results imply that the BLR is a partially ionized, dust-free, spherical shell that is collapsing, supersonically, at the free-fall velocity due to its proximity to a supermassive black hole. The BLR is ionization bounded at the outer radius, coincident with the dust reverberation radius, and transforms into an X-ray emitting plasma inside the Balmer reverberation radius as the central UV--X-ray source is approached. Only 40 M_Sun of Hydrogen are required to explain the Balmer emission line luminosity, but it is compressed by gravity into a column measuring 5.5 x 10^24 atoms/cm^2. Assuming radiatively inefficient accretion, the X-ray luminosity requires ~ 10^-2 M_sun/yr. However, the mass inflow rate required to explain the luminosity of the broad H-alpha emission line is ~1 M_sun/yr. The very large disparity between these two estimates indicates that 99% of the inflowing gas must be re-directed into an outflow, and on a very short timescale corresponding to ~40 years. Alternatively, the radiative efficiency of the inflow has been overestimated, or the X-ray luminosity has been underestimated; a distinct possibility if the BLR is indeed Compton thick.
Structure of a comprehensive solar radiation dataset

Abstract A new, comprehensive, file format has been developed for solar and other meteorological data from the University of Oregon’s Solar Radiation Monitoring (UO SRML) network in the Pacific Northwest. In an effort to provide essential information that would enable users to assess the quality and uncertainty in the data, a more comprehensive file format was developed that contains significantly more information about the station and the various instruments used to make the measurements. The file format utilizes month blocks and starts with a header containing detailed information about the site location, instruments used, calibration values utilized, and uncertainties in the calibration values. The second region of the file contains daily metadata for the instruments and useful information about the extraterrestrial irradiance and average nighttime offsets. After the metadata come the short-term data values and associated flags that help describe the status of the data. In addition, a variety of time stamps are used to facilitate the use of the data. The format also contains room for comments about the data, intended to help users see what was done to the data during the analysis process. Data in this comprehensive format is available on the UO SRML website at. ( http://solardat.uoregon.edu/SelectArchivalUpdatedFormat.html ).
Robust inertial sensing with point-source atom interferometry for interferograms spanning a partial period

Point source atom interferometry (PSI) uses the velocity distribution in a cold atom cloud to simultaneously measure one axis of acceleration and two axes of rotation from the spatial distribution of interferometer phase in an expanded cloud of atoms. Previously, the interferometer phase has been found from the phase, orientation, and period of the resulting spatial atomic interference fringe images. For practical applications in inertial sensing and precision measurement, it is important to be able to measure a wide range of system rotation rates, corresponding to interferograms with far less than one full interference fringe to very many fringes. Interferogram analysis techniques based on image processing used previously for PSI are challenging to implement for low rotation rates that generate less than one full interference fringe across the cloud. We introduce a new experimental method that is closely related to optical phase-shifting interferometry that is effective in extracting rotation values from signals consisting of fractional fringes as well as many fringes without prior knowledge of the rotation rate. The method finds the interferometer phase for each pixel in the image from four interferograms, each with a controlled Raman laser phase shift, to reconstruct the underlying atomic interferometer phase map without image processing.
Variability in multimodality treatment influences survival in non-metastatic gastric cancer patients

Background While gastric cancer is a leading cause of cancer-related mortality in Eastern Europe and Asia, it is less common in the USA. Recommendations regarding optimal treatment of non-metastatic gastric cancer (nmGC) with regard to type and extent of surgery, choice and sequence of chemotherapeutic agents, and use of radiation therapy vary across geographic locations. To determine how variability in treatment practices affects patient outcomes, we conducted a retrospective study to evaluate clinical outcomes in nmGC patients treated at four high-volume academic institutions. Methods California Cancer Registry data were collected for nmGC patients who underwent gastrectomy with curative intent from 2010 to 2018. We conducted chart reviews of the patients' electronic health records to validate clinical factors and outcomes. We performed multivariable Cox regressions to determine prognostic factors for outcomes. Results Demographics of study cohort (n=326): mean age 66 years; 64% male; 44% Caucasian, 35% Asian, 16% Latino. Tumor stage: 48% loco-regional (pT4 or pN1+) vs. 52% localized (pT1-3, pN0). Histology: 47% intestinal, 30% diffuse, 8% mixed, 15% unknown. Surgery: 34% open gastrectomy, 48% laparoscopic, 18% unknown; number of recovered lymph nodes varied from 0 to 60 in any tumor stage. Chemotherapy: 20% neoadjuvant alone, 25% adjuvant alone, 16% perioperative, 39% none. Multimodality therapy: 44% surgery only, 31% chemotherapy, 25% chemotherapy and radiation. With a median post-surgical follow-up of 6 years, 24% of patients developed recurrence and 40% had died. Compared to open surgery, laparoscopic surgeries were associated with fewer recovered lymph nodes (mean =18 vs. 25, P=0.0042). Fewer recovered lymph nodes were associated with a significant decrease in 5-year overall survival [hazard ratio (HR) =1.9, 95% confidence interval (CI): 1.3-2.8]. Timing of chemotherapy and addition of radiation therapy to chemotherapy did not confer further improvements in survival; in contrast, greater lymph node recovery plus chemotherapy were associated with a significant increase in survival (HR =0.3, 95% CI: 0.1-0.6). Conclusions This study highlights major practice differences in the management of nmGC patients across providers and institutions. Further efforts should be made to standardize the use of chemotherapy and adequate recovery and assessment of lymph nodes in this patient population.