cssi/SciSciGPT-SciSciNet huggingface dataset:
Growth Acceleration Following Renal Transplantation in Children Less Than 7 Years of Age

Of 110 consecutive renal allografts performed at Children9s Hospital Medical Center 12 were in 11 patients aged 3 to 7 years. Patient and graft survival and linear growth were evaluated in these 11 children. All 11 are surviving, seven (64%) with functioning allografts 12 to 92 months after transplant. Six of these seven have normal renal function (on alternate day prednisone dose
Management of Renovascular Problems During Aortic Operations

• Sixty patients who had primary aortic disease (aortic stenosis or aneurysm) and required simultaneous aortic and renal artery operations were divided according to the indications for renal artery repair as follows: group 1, renovascular hypertension (ten patients); group 2, kidney salvage (11 patients); group 3, improvement of renal function (three patients); and group 4, renal artery involvement in the diseased aorta (36 patients). Renal artery reimplantation and aortorenal grafting were usually employed. Two kidneys in the renal salvage group failed, and two main and three accessory arteries were found to be occluded on late follow-up. Three patients died after emergency surgery for aneurysm rupture (two patients) and infected false aneurysm (one patient). The mortality rate for combined operations is higher (5%) than for aortic or renal surgery alone, but simultaneous repair may be needed for technical reasons, or to treat renovascular disease. ( Arch Surg 1984;119:681-685)
Testicular Tumors in Infants and Children

Primary malignant tumors of the testis are uncommon in infants and children. Tumors of germ cell origin are identified most frequently. The clinical presentation is usually due to the presence of an enlarging scrotal mass. Determinations of the serum alpha fetoprotein (AFP) and beta subunit of human chorionic gonadotropin (beta-hCG) levels are helpful for diagnosis and management. All suspected testicular tumors should be surgically evaluated through a high inguinal incision. Postoperative chemotherapy is recommended for some patients with yolk sac tumor and all patients with embryonal rhabdomyosarcoma. Prolonged relapse-free survival is possible for most infants and children with malignant testicular tumors.
The riddle of high-energy baryon number violation

Abstract The exciting possibility that anomalous baryon and lepton number violation might be observable at the next generation of supercolliders is suggested by an instanton calculation due to Ringwald and Espinosa. In this review, the current controversial status of these claims is discussed, and several new technologies designed to analyze this question are reviewed. These technologies should contribute more generally to our understanding of weakly-coupled field theories in the nonperturbative regime where both energies and multiplicities are very large.
Visualization of Two-Phase Flow in Serpentine Heat Exchanger Passages With Microscale Pin Fins

Multiphase flow phenomena in single micro- and minichannels have been widely studied. Microchannel heat exchangers offer the potential for high heat transfer coefficients; however, implementation challenges must be addressed to realize this potential. Maldistribution of phases among the microchannels in the array and the changing phase velocities associated phase change present design challenges. Flow maldistribution and oscillatory instabilities can severely affect heat and mass transfer rates as well as pressure drops. In components such as condensers, evaporators, absorbers and desorbers, changing phase velocities can change prevailing flow regimes from favorable to unfavorable. Geometries with serpentine passages containing pin fins can be configured to maintain favorable flow regimes throughout the length of the component for diabatic phase-change heat and mass transfer applications. Due to the possibility of continuous redistribution of the flow across the pin fins along the flow direction, maldistribution can also be reduced. These features enable the potential of high heat transfer coefficients in microscale passages to be fully realized, thereby reducing the required transfer area, and achieving considerable compactness. The characteristics of two-phase flow through a serpentine passage with micro-pin fin arrays with diameters 350 μm and height 406 μm are investigated here. An air-water mixture is used to represent two-phase flow through the serpentine test section, and a variety of flow features are visually investigated using high-speed photography. Improved flow distribution is observed in the serpentine geometry. Distinct flow regimes, different from those observed in microchannels are also established. These observations are used to obtain void fraction and interfacial area along the length of the serpentine passages and compared with the corresponding values for straight microchannels. Models for the two-phase frictional pressure drops across this geometry are also developed.Copyright © 2016 by ASME
High order accurate finite difference schemes based on symmetry preservation

Abstract In this paper, we present a mathematical approach that is based on modified equations and the method of equivariant moving frames for construction of high order accurate invariant finite difference schemes that preserve Lie symmetry groups of underlying partial differential equations (PDEs). In the proposed approach, invariant (or symmetry preserving) numerical schemes with a desired (or fixed) order of accuracy are constructed from some non-invariant (base) numerical schemes. Modified forms of PDEs are used to improve the order of accuracy of existing schemes and these modified forms are obtained through addition of defect correction terms to the original forms of PDEs. These defect correction terms of modified PDEs that are noted from truncation error analysis are either completely removed from schemes or their representation is significantly simplified by considering convenient moving frames. This feature of the proposed method can especially be useful to avoid cumbersome numerical representations when high order schemes are developed from low order ones via the method of modified equations. The proposed method is demonstrated via construction of invariant numerical schemes with fixed (and higher) order of accuracy for some common linear and nonlinear problems (including the linear advection–diffusion equation in 1D and 2D, inviscid Burgers' equation, and viscous Burgers' equation) and the performance of these invariant numerical schemes is further evaluated. Our results indicate that such invariant numerical schemes obtained from existing base numerical schemes have the potential to significantly improve the quality of results not only in terms of desired higher order accuracy but also in the context of preservation of appropriate symmetry properties of underlying PDEs.
A data-driven distributionally robust bound on the expected optimal value of uncertain mixed 0-1 linear programming

This paper studies the expected optimal value of a mixed 0-1 programming problem with uncertain objective coefficients following a joint distribution. We assume that the true distribution is not known exactly, but a set of independent samples can be observed. Using the Wasserstein metric, we construct an ambiguity set centered at the empirical distribution from the observed samples and containing the true distribution with a high statistical guarantee. The problem of interest is to investigate the bound on the expected optimal value over the Wasserstein ambiguity set. Under standard assumptions, we reformulate the problem into a copositive program, which naturally leads to a tractable semidefinite-based approximation. We compare our approach with a moment-based approach from the literature on three applications. Numerical results illustrate the effectiveness of our approach.
Revisiting the effect of food aid on conflict : a methodological caution

A popular identification strategy in non-experimental panel data uses instrumental variables constructed by interacting exogenous but potentially spurious time series or spatial variables with endogenous exposure variables to generate identifying variation through assumptions like those of differences-in-differences estimators. Revisiting a celebrated study linking food aid and conflict shows that this strategy is susceptible to bias arising from spurious trends. Re-randomization and Monte Carlo simulations show that the strategy identifies a spurious relationship even when the true effect could be non-causal or causal in the opposite direction, invalidating the claim that aid causes conflict and providing a caution for similar strategies.
Nonvanishing of central L-values of Maass forms

Abstract With the method of moments and the mollification method, we study the central L-values of GL(2) Maass forms of weight 0 and level 1 and establish a positive-proportional nonvanishing result of such values in the aspect of large spectral parameter in short intervals, which is qualitatively optimal in view of Weyl's law. As an application of this result and a formula of Katok–Sarnak, we give a nonvanishing result on the first Fourier coefficients of Maass forms of weight 1 2 and level 4 in the Kohnen plus space.
Demand and supply curves in political markets : understanding the problem of public goods and why governments fail them

This paper brings the economic tools of demand and supply curves to better understand how political markets shape the selection of government policies. It does so to tackle a problem at the intersection of political science and economics: government failure to pursue policies on the basis of sound technical evidence. Too often, the leaders who wield policy-making power within governments deliberately and knowingly ignore sound technical advice, or are unable to pursue it despite the best of intentions, because of political constraints. The paper shows how the prevailing dominant explanation for suboptimal policies and weak institutions, of special interest and elite capture, can be understood as the selection of a point on the political demand curve by oligopolistic political competition. Further, it shows how elite capture is only one of many possible outcomes, and is endogenous to preferences and beliefs in society. Preferences in society for public goods (or the lack thereof), and beliefs about how others are behaving in the public sector, are the primitive or fundamental elements driving the shapes of political demand and supply curves and thence the selection of public policies and institutions. This framework highlights the need for future research to understand where political preferences and beliefs come from, which is essential to the design of institutions that address problems of public goods.
Keeping the bay in Glacier Bay National Park: Introducing glacier science to the United States Supreme Court

ABSTRACT In 2000, seventy-five years after the founding of Glacier Bay National Monument, the United States Supreme Court authorized the State of Alaska to begin legal proceedings related to the ownership of ‘certain marine submerged lands in southeast Alaska’ including the submerged lands contained within what is now Glacier Bay National Park. This narrative presents a summary of how glacier science (glacial geology and glaciology) became an integral part of the argument prepared and presented by the United States Government in response to the State of Alaska's Complaint.
Along-strike variability of primitive magmas (major and volatile elements) inferred from olivine-hosted melt inclusions, southernmost Andean Southern Volcanic Zone, Chile

Abstract Glass compositions of melt inclusions in olivine phenocrysts found in tephras derived from explosive eruptions of the four volcanoes along the volcanic front of the southernmost Andean Southern Volcanic Zone (SSVZ) are used to constrain primitive magma compositions and melt generation parameters. Primitive magmas from Hudson, Maca, and Melimoyu have similar compositions and are formed by low degrees (8–18%) of partial melting. Compared to these other three centers, primitive magmas from Mentolat have higher Al2O3 and lower MgO, TiO2 and other incompatible minor elements, and are generated by somewhat higher degrees (12–20%) of partial melting. The differences in the estimated primitive parental magma compositions between Mentolat and the other three volcanic centers are consistent with difference in the more evolved magmas erupted from these centers, Mentolat magmas having higher Al2O3 and lower MgO, TiO2 and other incompatible minor element contents, suggesting that these differences are controlled by melting processes in the mantle source region above the subducted oceanic plate. Parental magma S = 1430–594 and Cl = 777–125 (μg/g) contents of Hudson, Maca, and Melimoyu are similar to other volcanoes further north in the SVZ. However, Mentolat primitive magmas have notably higher concentrations of S = 2656–1227 and Cl = 1078–704 (μg/g). The observed along-arc changes in parental magma chemistry may be due to the close proximity below Mentolat of the subducted Guamblin Fracture Zone that could efficiently transport hydrous mineral phases, seawater, and sediment into the mantle, driving enhanced volatile fluxed melting beneath this center compared to the others.
Role of tear anti-acanthamoeba IgA in Acanthamoeba keratitis

Acanthamoeba keratitis is a sight-threatening corneal disease caused by pathogenic free-living amoebae.1The organisms have been isolated from a wide variety of environments and from nasopharyngeal washes of asymptomatic individuals. 1Contact lens wear, practiced by over 25 million individuals in the United States, is the leading risk factor. Over 85% of the cases of Acanthamoeba keratitis occurred in contact lens wearers.2 Antibodies against Acanthamoeba spp. were detected in 52-100% of normal subjects tested in two serological surveys.3,4 In spite of the ubiquity of Acanthamoeba spp., the large number of contact lens wearers, and the apparent frequency of exposure to Acanthamoeba antigens, Acanthamoeba keratitis is rare. We hypothesized that frequent environmental exposure to Acanthamoeba antigens induces an immunity that protects against corneal infection in most contact lens wearers.
BPM for the Masses: Empowering Participants of Cognitive Business Processes

Authoring, developing, monitoring, and analyzing business processes has required both domain and IT expertise since Business Process Management tools and practices have focused on enterprise applications and not end users. There are trends, however, that can greatly lower the bar for users to author and analyze their own processes. One emerging trend is the attention on blockchains as a shared ledger for parties collaborating on a process. Transaction logs recorded in a standard schema and stored in the open significantly reduces the effort to monitor and apply advanced process analytics. A second trend is the rapid maturity of machine learning algorithms, in particular deep learning models, and their increasing use in enterprise applications. These cognitive technologies can be used to generate views and processes customized for an end user so they can modify them and incorporate best practices learned from other users’ processes.
Prescriptive modeling and compensation of in-plane shape deformation for 3-D printed freeform products

Although 3D printing or additive manufacturing (AM) holds great promise as a direct manufacturing technology, the geometric accuracy of AM built products remains a critical issue, especially for freeform products with complex geometric shapes. Efforts have long been attempted to improve the accuracy of AM built freeform products. But there is a lack of generic and prescriptive methodology transparent to specific designs and AM processes. This study fills the gap by establishing the methodology to predict and compensate the in-plane (x — y plane) geometric deformation of AM built freeform products using a limited number of simple trial shapes. Built upon our previous predictive model and optimal compensation study for cylinder and polyhedron shapes, this work makes a breakthrough by directly controlling arbitrary freeform shape deformation from CAD design. Experimental investigation using stereolithography process successfully validates the proposed prescriptive modeling and compensation methodology. The study provides the prospect of proactively improving printing accuracy of arbitrary products built by a varieties of AM processes.
'Unfinished Business': Historic Complementarities, Political Competition and Ethnic Violence in Gujarat

Abstract I examine how the historical legacies of inter-ethnic complementarity and competition interact with contemporary electoral competition in shaping patterns of ethnic violence. Using local comparisons within Gujarat, a single Indian state known for both its non-violent local traditions and for widespread ethnic pogroms in 2002, I provide evidence that where political competition was focused upon towns where ethnic groups have historically competed, there was a rise in the propensity for ethnic rioting and increased electoral support for the incumbent party complicit in the violence. However, where political competition was focused in towns that historically enjoyed inter-ethnic complementarities, there were fewer ethnic riots, and these towns also voted against the incumbent. These historic legacies proved to be important predictors of the identity of the winner even in very close electoral races. I argue that these results reflect the role local inter-ethnic economic relations can play in altering the nature and the benefits of political campaigns that encourage ethnic violence.
“At Sea”: Reversibility in Teaching and Learning

An equal-armed balance at equilibrium—the bar is horizontal—tips into disequilibrium upon displacing a weight. Equilibrium is restored by reversing that move—putting the weight back where it was, or doing the same on the other side. Piaget adopted the idea of equilibration to describe how the intellect, in relating to the world, develops. Equilibrium arises as: our mind adjusts its structures in response to the outer world (accommodation), so our internalized views can take in this outer world (assimilation). That is the process Piaget calls equilibration. Upon undergoing disequilibrium, the intellect employs these equilibrating moves, changing its structures in the process. When the intellect resolves a disturbing problem no matter how it is encountered, the intellect tries to reverse the disturbing feature: how did the familiar situation get to this disturbing one; how might that change be reversed? These equilibrating processes are encouraged as means of teaching and learning in this paper’s math and science examples. The clinical interviewing methodology of Piaget and Inhelder, as adapted by Eleanor Duckworth in the research pedagogy of clinical exploration in the classroom, provides the neutral, safe conditions requisite for these learners and teachers in undergoing disequilibrium, struggling with uncertainty, and constructing new understandings. In beginning to teach through exploration, the author and an undergraduate experimented with free fall motion. Experiencing disequilibrium, the student reconstructed her understanding of time as concurrently continuous and divisible. Seeking to enact methods of Piaget and Duckworth while engaging her, the teacher also experienced disequilibrium.
Fast Core Pricing for Rich Advertising Auctions

As online ad offerings become increasingly complex, with multiple size configurations and layouts available to advertisers, the sale of web advertising space increasingly resembles a combinatorial auction with complementarities. Standard ad auction formats do not immediately extend to these settings, and truthful combinatorial auctions, such as the Vickrey-Clarke-Groves auction, can yield unacceptably low revenue. Core selecting auctions, which apply to combinatorial markets, boost revenue by setting prices so that no group of agents, including the auctioneer, can jointly improve their utilities by switching to a different allocation and payments. Among outcomes in the core, bidder-optimal core points have been the most widely studied due to their incentive properties, such as being implementable at natural equilibria.Prior work in economics has studied heuristics and algorithms for computing approximate bidder-optimal core points, given oracle access to the welfare optimization problem. Relative to prior work, our goal is to develop an algorithm with asymptotically fewer oracle calls while maintaining theoretical performance guarantees. Our main result is a combinatorial algorithm that finds an approximate bidder-optimal core point with almost linear number of calls to the welfare maximization oracle. Our algorithm is faster than previously-proposed heuristics, it has theoretical guarantees, and it reveals some useful structural properties of the core polytope.We take a two-pronged approach to evaluating our core-pricing method. We first consider a theoretical treatment of the problem of finding a bidder-optimal core point in a general combinatorial auction setting. We then consider an experimental treatment of deploying our algorithm in a highly time-sensitive advertising auction platforms.
The Monomeric G Proteins AGS1 and Rhes Selectively Influence Gαi-dependent Signaling To Modulate N-type (CaV2.2) Calcium Channels

∗To whom correspondence should be addressed. E-mail: brett@biology.usu.edu.Activator of G protein Signaling 1 (AGS1) and Ras homologue enriched in striatum (Rhes) define a new group of Ras-like monomeric G proteins whose signaling properties and physiological roles are just beginning to be understood. Previous results suggest that AGS1 and Rhes exhibit distinct preferences for heterotrimeric G proteins, with AGS1 selectively influencing Gαi and Rhes selectively influencing Gαs. Here, we demonstrate that AGS1 and Rhes trigger nearly identical modulation of N-type Ca2+ channels (CaV2.2) by selectively altering Gαi-dependent signaling. Whole-cell currents were recorded from HEK293 cells expressing CaV2.2 and Gαi- or Gαs-coupled receptors. AGS1 and Rhes reduced basal current densities and triggered tonic voltage-dependent (VD) inhibition of CaV2.2. Furthermore, each protein attenuated agonist-initiated channel inhibition through Gαi-coupled receptors without reducing channel inhibition through a Gαs-coupled receptor. The above effects of AGS1 and Rhes were blocked by pertussis toxin (PTX) or by expression of a Gβγ-sequestering peptide (masGRK3ct). Transfection with HRas, KRas2, Rap1A-G12V, Rap2B, Rheb2 or Gem failed to mimic the effects of AGS1 and Rhes on CaV2.2. Our data provide the first demonstration that AGS1 and Rhes exhibit similar if not identical signaling properties since both trigger tonic Gβγ signaling and both attenuate receptor-initiated signaling by the Gβγ subunits of PTX-sensitive G proteins. These results are consistent with the possibility that AGS1 and Rhes modulate Ca2+ influx through CaV2.2 channels under more physiological conditions and thereby influence Ca2+-dependent events such as neurosecretion.
Rethinking performance based parking pricing: A case study of SFpark

Abstract In an effort to reduce circling and cruising in cities’ central business districts (CBDs), a number of cities have begun implementing pricing programs that modify parking rates based on observed occupancy levels. We improve on this pricing mechanism by developing a forward-looking policy instrument. The instrument employs a two-stage panel data regression and optimization model that influences demand for parking spaces by changing parking rates via computed price elasticities of parking demand measures. Coefficient estimates that include the elasticity measures from the panel data regression are used to fit a linear prediction model that is the primary input to the optimization model. An application of the approach is presented using SFpark, a federal government-funded demonstration program in San Francisco as a case study. We evaluate the effectiveness of the modified pricing mechanism by comparing actual occupancy and parking rate tuples with the optimized result to ascertain the potential improvement in SFpark’s performance. Policy scenarios are subsequently explored by carrying out sensitivity analysis primarily through SFpark pricing rules. Relative to SFpark’s figures, our model yielded approximately 16% improvement in systems performance when measured by the number of blocks that deviate from the 60 to 80% occupancy target. Our findings highlight the importance of moving towards a predictive regime that allows for proactively managing the parking program compared to a reactive approach based on observed parking occupancy.
Acute drug effects on habitual and non-habitual responding in crossed high alcohol preferring mice

Drug reward plays a central role in acquiring drug-seeking behavior. However, subjects may continue using drugs despite negative consequences because self-administration becomes habitual, and divorced from outcome values. Although a history of drug and alcohol use expedite habit acquisition, and in spite of the fact that self-administration leads to intoxication, the acute effects of drugs on habitual responding are not well understood. We sought to observe how acute ethanol and amphetamine affect the balance between habitual and goal-directed behavior, as measured by a fluid-reinforced operant conditioning task. Selectively bred crossed high-alcohol-preferring (cHAP) mice were trained on an operant conditioning task reinforced on a variable interval schedule with 1% banana solution, which was subsequently devalued via LiCl pairing in half the animals. Ethanol (1.0 g/kg), amphetamine (2.0 mg/kg), or saline was administered prior to a post-devaluation test. Overall, mice showed habitual behavior, but when divided into high- or low-responding groups based on training response rates, saline-treated, low-responding animals devalued, while saline-treated high-responding animals did not. Furthermore, amphetamine elicited devaluation even in high-responding animals, while ethanol prevented devaluation even in low-responding animals. These data show that ethanol shifts animals toward behaving habitually. This may illuminate why alcohol-intoxicated individuals display impaired judgment about the relative merits of drinking, and potentially serve as a mechanism by which intoxicated subjects resume previously devalued behaviors, such as comorbid drug use. These findings also show that high variable interval response rates facilitate a shift from goal-directed to habitual behavior.
The Effect of Pet Therapy and Artist Interactions on Quality of Life in Brain Tumor Patients: A Cross-Section of Art and Medicine in Dialog.

With the evolution of modern medical treatment strategies, there also comes the realization that many times we reach a point where traditional goals of medical care, such as overall survival or disease-free survival, are not realistic goals for many patients facing devastating illnesses. One such disease is malignant primary brain tumors, known as malignant glioma (MG). With median survival of only 20.9 months following best available standard of care treatment strategies, including surgery, chemotherapy, radiation, and tumor treating fields, MG is one of the deadliest malignancies of the modern era. Along the course of treating patients with MG, clinicians often realize that traditional treatment therapies can at best provide incremental benefit of symptom management without any survival benefit. However, even in these difficult situations, it is possible to make significant positive changes in patients’ health-related quality of life (HRQoL) using creative, non-traditional interventions. In this paper, we describe the initial findings from our project that takes a unique approach to studying the intersections of clinical care and art by using pet therapy and art-making as interventions for patients diagnosed with brain tumors. Our preliminary findings suggest that pet therapy and the ability to reflect as well as speak about their journey through a life-altering disease significantly increases patients’ overall feeling of wellbeing and reduces anxiety about future uncertainty.
Do Properly Anticipated Prices Fluctuate Randomly? Evidence from VIX Futures Markets

The VIX index is not traded on the spot market. Hence, in contrast to other futures markets, the VIX futures contract and spot index are not linked by a no-arbitrage condition. The authors examine (1) whether predictability in the VIX index carries over to the futures market and (2) whether there is independent time-series predictability in VIX futures prices. The answer to both questions is no. Samuelson was right: VIX futures prices properly anticipate predictability in volatility and are themselves unpredictable. TOPICS:Futures and forward contracts, volatility measures Key Findings • The authors examine (1) whether predictability in the VIX generates predictability in VIX futures and (2) whether time-series momentum in VIX futures is profitable. • Aside from the obvious importance for understanding price formation, these questions are important for practitioners given the recent spike in VIX, the large and active market in trading volatility and volatility insurance strategies, and the demand for investment advice on what to do. • The short answer to both questions is no, especially after adjusting for risk and realistic transactions costs.
The impact of client information technology capability on audit pricing

Abstract This paper explores the question: “How does a client's information technology (IT) capability influence audit pricing?” Company data for the years 2004 through 2012 are employed. Firms appearing on the InformationWeek 500 (IW500) annual list of U.S. organizations with superior IT functions serve as a proxy for companies with superior IT capability. Our findings suggest that companies with superior IT capabilities incur higher levels of audit fees. In addition, as client size increases, the audit fees of firms with advanced IT capabilities increase at a greater rate than firms without such capabilities. These findings contrast with prior research by Chen et al. (2014) that found in the immediate post-Sarbanes-Oxley Act (SOX) period for the years 2004 through 2007, client IT capability reduced audit fee increases. In addition, we replicate the Chen et al. (2014) results and find that IT capability did not influence audit fee increases during the subsequent recession and recovery periods. Further, superior capability clients see smaller audit fee increases when exogenous shocks such as SOX regulations occur. These results suggest a revised interpretation of Chen et al. (2014) may be warranted. This study contributes to the literature by providing a more complete picture of how a client's IT capability affects audit fees.
Network Global Testing by Counting Graphlets

Consider a large social network with possibly severe degree heterogeneity and mixed-memberships. We are interested in testing whether the network has only one community or there are more than one communities. The problem is known to be non-trivial, partially due to the presence of severe degree heterogeneity. We construct a class of test statistics using the numbers of short paths and short cycles, and the key to our approach is a general framework for canceling the effects of degree heterogeneity. The tests compare favorably with existing methods. We support our methods with careful analysis and numerical study with simulated data and a real data example.
DO ANALYSTS WHO MOVE MARKETS HAVE BETTER CAREERS

In this article I investigate the association between analystsâ€™ ability to issue influential recommendations and their career outcomes. The fraction of recommendations that are defined as influential are linked to a higher probability of an analyst moving to a higher status brokerage house, and a lower probability of either being demoted to a lower status brokerage house or leaving the profession. Analysts who more often issue influential recommendations also have a higher chance of being ranked by Institutional Investor Allâ€ America, having longer careers, and experiencing lower job turnover compared to peers.
Temporal logic can be more expressive

It is first proved that there are properties of sequences that are not expressible in temporal logic, even though they are easily expressible using, for instance, regular expressions. Then, it is shown how temporal logic can be extended to express any property definable by a right-linear grammar and hence a regular expression. Finally, a complete axiomatization and a decision procedure for the extended temporal logic are given and the complexity of the extended logic is examined.
Multiple Instance Learning for Heterogeneous Images: Training a CNN for Histopathology

Multiple instance (MI) learning with a convolutional neural network enables end-to-end training in the presence of weak image-level labels. We propose a new method for aggregating predictions from smaller regions of the image into an image-level classification by using the quantile function. The quantile function provides a more complete description of the heterogeneity within each image, improving image-level classification. We also adapt image augmentation to the MI framework by randomly selecting cropped regions on which to apply MI aggregation during each epoch of training. This provides a mechanism to study the importance of MI learning. We validate our method on five different classification tasks for breast tumor histology and provide a visualization method for interpreting local image classifications that could lead to future insights into tumor heterogeneity.
Spatial distribution of pressure resonance in compressible cavity flow

The development of the unsteady pressure field on the floor of a rectangular cavity was studied at Mach 0.9 using high-frequency pressure-sensitive paint. Power spectral amplitudes at each cavity resonance exhibit a spatial distribution with a streamwise-oscillatory pattern; additional maxima and minima appear as the mode number is increased. This spatial distribution also appears in the propagation velocity of modal pressure disturbances. This behaviour was tied to the superposition of a downstream-propagating shear-layer disturbance and an upstream-propagating acoustic wave of different amplitudes and convection velocities, consistent with the classical Rossiter model. The summation of these waves generates a net downstream-travelling wave whose amplitude and phase velocity are modulated by a fixed envelope within the cavity. This travelling-wave interpretation of the Rossiter model correctly predicts the instantaneous modal pressure behaviour in the cavity. Subtle spanwise variations in the modal pressure behaviour were also observed, which could be attributed to a shift in the resonance pattern as a result of spillage effects at the edges of the finite-width cavity.
Systemic centrality and systemic communities in financial networks

A systemically important firm could be too-connected-to-fail and/or too-important-to-fail,two properties which centrality measures and community detection methods can capture respectively.This paper examines the performance of these measures in a variance decomposition global financialnetwork. Too-connected-to-fail risk and vulnerability rankings are quite robust to the choice ofcentrality measure. The PageRank centrality measure, however, does not seem as suitable for assessingvulnerabilities. Two community identification methods, edge betweenness and the map equation(Infomap) were used to identify systemic communities, which in turn capture the too-important-tofaildimension of systemic risk. The first method appears more robust to di erent weighting schemesbut tends to isolate too many firms. The second method exhibits the opposite characteristics. Overall,the analysis suggests that centrality measures and community identification methods complement eachother for assessing systemic risk in financial networks.
The Dynamics of Peer-Produced Political Information During the 2016 U.S. Presidential Campaign.

Wikipedia plays a crucial role for online information seeking and its editors have a remarkable capacity to rapidly revise its content in response to current events. How did the production and consumption of political information on Wikipedia mirror the dynamics of the 2016 U.S. Presidential campaign? Drawing on systems justification theory and methods for measuring the enthusiasm gap among voters, this paper quantitatively analyzes the candidates' biographical and related articles and their editors. Information production and consumption patterns match major events over the course of the campaign, but Trump-related articles show consistently higher levels of engagement than Clinton-related articles. Analysis of the editors' participation and backgrounds show analogous shifts in the composition and durability of the collaborations around each candidate. The implications for using Wikipedia to monitor political engagement are discussed.
Explainable Neural Computation via Stack Neural Module Networks

In complex inferential tasks like question answering, machine learning models must confront two challenges: the need to implement a compositional reasoning process, and, in many applications, the need for this reasoning process to be interpretable to assist users in both development and prediction. Existing models designed to produce interpretable traces of their decision-making process typically require these traces to be supervised at training time. In this paper, we present a novel neural modular approach that performs compositional reasoning by automatically inducing a desired sub-task decomposition without relying on strong supervision. Our model allows linking different reasoning tasks though shared modules that handle common routines across tasks. Experiments show that the model is more interpretable to human evaluators compared to other state-of-the-art models: users can better understand the model’s underlying reasoning procedure and predict when it will succeed or fail based on observing its intermediate outputs.
Bipedal Hopping: Reduced-Order Model Embedding via Optimization-Based Control

This paper presents the design and validation of controlling hopping on the 3D bipedal robot Cassie. A spring-mass model is identified from the kinematics and compliance of the robot. The spring stiffness and damping are encapsulated by the leg length, thus actuating the leg length can create and control hopping behaviors. Trajectory optimization via direct collocation is performed on the spring-mass model to plan jumping and landing motions. The leg length trajectories are utilized as desired outputs to synthesize a control Lyapunov function based quadratic program (CLF-QP). Centroidal angular momentum, taking as an addition output in the CLF-QP, is also stabilized in the jumping phase to prevent whole body rotation in the underactuated flight phase. The solution to the CLF-QP is a nonlinear feedback control law that achieves dynamic jumping behaviors on bipedal robots with compliance. The framework presented in this paper is verified experimentally on the bipedal robot Cassie.
Stock Market Returns and GDP News

What is the link between stock returns and news about economic growth? Using consensus forecasts from the Philadelphia Fed’s Survey of Professional Forecasters, I find that the univariate associati...
Ultimatum game bargaining in a partially directed search market

Abstract We investigate a partially directed search and bargaining market with a laboratory experiment. First, sellers post intervals of possible surplus splits (i.e. the payoffs that would result from posting possible prices) that direct buyers to approach them. Second, after matching occurs, final surpluses are determined by ultimatum game bargaining. We investigate the interaction between bargaining and competition in the preliminary search stage, with a focus on how preferences for fair bargaining outcomes affect search. The main results confirm that behavior in the ultimatum game is consistent with preferences for fair outcomes, and the main effect on search is to drive up the posted buyer surplus lower bounds above the competitive equilibrium towards more equal surplus splits. Our main treatment variable is the number of buyers in the market, and when the number of buyers is increased, lower bounds and ultimatum offers to buyers decrease. This is consistent with fairness perceptions being influenced by competition.
Linked Causal Variational Autoencoder for Inferring Paired Spillover Effects

Modeling spillover effects from observational data is an important problem in economics, business, and other fields of research. It helps us infer the causality between two seemingly unrelated set of events. For example, if consumer spending in the United States declines, it has spillover effects on economies that depend on the U.S. as their largest export market. In this paper, we aim to infer the causation that results in spillover effects between pairs of entities (or units); we call this effect as paired spillover. To achieve this, we leverage the recent developments in variational inference and deep learning techniques to propose a generative model called Linked Causal Variational Autoencoder (LCVA). Similar to variational autoencoders (VAE), LCVA incorporates an encoder neural network to learn the latent attributes and a decoder network to reconstruct the inputs. However, unlike VAE, LCVA treats the latent attributes as confounders that are assumed to affect both the treatment and the outcome of units. Specifically, given a pair of units u and $\baru $, their individual treatment and outcomes, the encoder network of LCVA samples the confounders by conditioning on the observed covariates of u, the treatments of both u and $\baru $ and the outcome of u. Once inferred, the latent attributes (or confounders) of u captures the spillover effect of $\baru $ on u. Using a network of users from job training dataset (LaLonde (1986)) and co-purchase dataset from Amazon e-commerce domain, we show that LCVA is significantly more robust than existing methods in capturing spillover effects.
Pathways to formalization: Going beyond the formality dichotomy. The case of Peru

Too often, academics and policy makers interpret formality as a binary choice and formalization as an irreversible process. Yet, formalization has many facets and shades on the business and labor fronts, and firms may not be able or willing to formalize all at once. This paper explores the joint process of business and labor formalization, using a unique panel data set of Peruvian micro enterprises. The paper finds that business formality does not imply labor formality, and vice versa. Further, there is significant churning in and out of different dimensions of formality within a relatively short period. Using an instrumental variable approach, the paper infers that business formalization affects labor formalization but not the other way around, and that enforcement is a key driver of formalization. Overall, the analysis shows that formalization is a gradual and reversible process, with small entrepreneurs weighing their possibilities in each pathway to business (often) or labor (less often) formalization, but rarely both at the same time.
Solving Directed Laplacian Systems in Nearly-Linear Time through Sparse LU Factorizations

In this paper, we show how to solve directed Laplacian systems in nearly-linear time. Given a linear system in an n × n Eulerian directed Laplacian with m nonzero entries, we show how to compute an e-approximate solution in time O(m log^O(1) (n) log (1/e)). Through reductions from [Cohen et al. FOCS'16], this gives the first nearly-linear time algorithms for computing e-approximate solutions to row or column diagonally dominant linear systems (including arbitrary directed Laplacians) and computing e-approximations to various properties of random walks on directed graphs, including stationary distributions, personalized PageRank vectors, hitting times, and escape probabilities. These bounds improve upon the recent almost-linear algorithms of [Cohen et al. STOC'17], which gave an algorithm to solve Eulerian Laplacian systems in time O((m+n2^O(√ log n log log n))log^O(1)(n e^-1)). To achieve our results, we provide a structural result that we believe is of independent interest. We show that Eulerian Laplacians (and therefore the Laplacians of all strongly connected directed graphs) have sparse approximate LU-factorizations. That is, for every such directed Laplacian there are lower upper triangular matrices each with at most O(n) nonzero entries such that there product spectrally approximates the directed Laplacian in an appropriate norm. This claim can be viewed as an analog of recent work on sparse Cholesky factorizations of Laplacians of undirected graphs. We show how to construct such factorizations in nearly-linear time and prove that once constructed they yield nearly-linear time algorithms for solving directed Laplacian systems.
Sales Force and Competition in Financial Product Markets: The Case Of Mexico’s Social Security Privatization

This paper examines how sales force impacts competition and equilibrium prices in the context of a privatized pension market. We use detailed administrative data on fund manager choices and worker characteristics at the inception of Mexico's privatized social security system, where fund managers had to set prices (management fees) at the national level, but could select sales force levels by local geographic areas. We develop and estimate a model of fund manager choice where sales force can increase or decrease customer price sensitivity. We find exposure to sales force lowered price sensitivity, leading to inelastic demand and high equilibrium fees. We simulate oft proposed policy solutions: a supply‐side policy with a competitive government player and a demand‐side policy that increases price elasticity. We find that demand‐side policies are necessary to foster competition in social safety net markets with large segments of inelastic consumers.
Dynamic regulation of dynein localization revealed by small molecule inhibitors of ubiquitination enzymes

Cytoplasmic dynein is a minus-end-directed microtubule-based motor that acts at diverse subcellular sites. During mitosis, dynein localizes simultaneously to the mitotic spindle, spindle poles, kinetochores and the cell cortex. However, it is unclear what controls the relative targeting of dynein to these locations. As dynein is heavily post-translationally modified, we sought to test a role for these modifications in regulating dynein localization. We find that dynein rapidly and strongly accumulates at mitotic spindle poles following treatment with NSC697923, a small molecule that inhibits the ubiquitin E2 enzyme, Ubc13, or treatment with PYR-41, a ubiquitin E1 inhibitor. Subsets of dynein regulators such as Lis1, ZW10 and Spindly accumulate at the spindle poles, whereas others do not, suggesting that NSC697923 differentially affects specific dynein populations. We additionally find that dynein relocalization induced by NSC697923 or PYR-41 can be suppressed by simultaneous treatment with the non-selective deubiquitinase inhibitor, PR-619. However, we did not observe altered dynein localization following treatment with the selective E1 inhibitor, TAK-243. Although it is possible that off-target effects of NSC697923 and PYR-41 are responsible for the observed changes in dynein localization, the rapid relocalization upon drug treatment highlights the highly dynamic nature of dynein regulation during mitosis.