cssi/SciSciGPT-SciSciNet huggingface dataset:
Mortgage Market Design

This article explores the causes and consequences of cross-country variation in mortgage market structure. It draws on insights from several fields: urban economics, asset pricing, behavioral finance, financial intermediation, and macroeconomics. It discusses lessons from the credit boom, the challenges of mortgage modification in the aftermath of the boom, consumer financial protection, and alternative mortgage forms and funding models. The article argues that the USA has much to learn from mortgage finance in other countries, and specifically from the Danish implementation of the European covered bonds system.
A Theoretical and Empirical Analysis of the Decision to Locate on a University Research Park

University research parks constitute a potentially important mechanism for university technology transfer and regional economic development. Unfortunately, there is little theoretical or empirical evidence on the firm-level choice decision to locate on such a facility. We fill this gap by outlining and testing a theoretical model of this selection process. Our empirical results suggest that U.S. firms locating on university research parks are more research active and more diversified than the typical public firm reporting R&D activity. We discuss the managerial implications of these findings.
Experimental and Theoretical Observations of Aromaticity in Heterocyclic XAl3− (X=Si, Ge, Sn, Pb) Systems

1: [(Cp*2 ZrH3Li)3] (0.1 g, 0.27 mmol) was dissolved in THF (3 mL), PH2CH2CH2PH2 (1.0 g, 10.87 mmol) was added dropwise to the stirred, colorless solution which became green, then aquamarine, and finally blue, over a period of 30 min. The reaction was stirred for 72 h, until it became colorless. Solvent was removed in vacuo, leaving a white solid which was dissolved in hexane, filtered, and placed in a freezer (y35 8C). Colorless, X-ray quality crystals (0.86 g, 87% yield) precipitated from solution, over 24 h. 1H NMR (C6D6): d 3.65 (dt, 2H, 1JP,H 330, 3JH,H 10 Hz), 2.43 (m, 2H), 1.87 (m, 2H), 1.14 (m, 2H), 0.74 (m, 2H); 13C{1H} NMR (C6D6): d 38.36, 30.66; 31P NMR (C6D6): dy22.5 (P1: JP1,P1y237, JP1,P0y186, 2JP1,P0 20 Hz), y65.4 (P0: 1JP1,P1y237, 1JP1,P0y186, 2JP1,P0 20 Hz); elemental analysis (%) calcd for P4C4H10: C 26.39, H 5.54; found: C 26.18, H 5.42.
Anonymous Networking Amidst Eavesdroppers

The problem of security against packet timing based traffic analysis in wireless networks is considered in this work. An analytical measure of ldquoanonymityrdquo of routes in eavesdropped networks is proposed using the information-theoretic equivocation. For a physical layer with orthogonal transmitter directed signaling, scheduling and relaying techniques are designed to maximize achievable network performance for any desired level of anonymity. The network performance is measured by the total rate of packets delivered from the sources to destinations under strict latency and medium access constraints. In particular, analytical results are presented for two scenarios: For a single relay that forwards packets from users, relaying strategies are provided that minimize the packet drops when the source nodes and the relay generate independent transmission schedules. A relay using such an independent scheduling strategy is undetectable by an eavesdropper and is referred to as a covert relay. Achievable rate regions are characterized under strict and average delay constraints on the traffic, when schedules are independent Poisson processes. For a multihop network with an arbitrary anonymity requirement, the problem of maximizing the sum-rate of flows (network throughput) is considered. A randomized selection strategy to choose covert relays as a function of the routes is designed for this purpose. Using the analytical results for a single covert relay, the strategy is optimized to obtain the maximum achievable throughput as a function of the desired level of anonymity. In particular, the throughput-anonymity relation for the proposed strategy is shown to be equivalent to an information-theoretic rate-distortion function.
Identification of System, Observer, and Controller from Closed-Loop Experimental Data

This paper considers the identification problem of a system operating in a closed loop with an existing feedback controller. The closed-loop system is excited by a known excitation signal, and the resulting time histories of the closed-loop system response and the feedback signal are measured. From the time history data, the algorithm computes the Markov parameters of a closed-loop observer, from which the Markov parameters of the individual open-loop plant, observer, and controller are recovered. A state-space model of the open-loop plant and the gain matrices for the controller and the observer are then realized. The results of the paper are demonstrated by an example using wind tunnel aircraft flutter test data.
Luge track safety

Simple geometric models of ice surface shapes and equations of motion of objects on these surfaces can be used to explain ejection of sliders from ice tracks. Simulations employing these explain why certain design features can be viewed as proximate causes of ejection from the track and hence design flaws. This paper studies the interaction of a particle model for the luge sled (or its right runner) with the ice fillet commonly connecting inside vertical walls in turns to the flat track bottom. A numerical example analyzes the 2010 luge accident at the Vancouver Olympics. It shows that this runner-fillet interaction, and specifically the fillet’s positive curvature up the inside wall, can cause a vertical velocity more than sufficient to clear the outside exit wall. In addition the negative curvature of the fillet along the track and the large vertical velocity, explain loss of fillet or wall contact and slider ejection. This exposes the fillet along inside walls as a track design flaw. A more transparent track design and review process could provide more complete and thorough design and verification scrutiny by competent scientists and engineers without financial involvement or conflicts of interest and potentially lead to safer future designs.
A time-domain surface integral technique for mixed electromagnetic and circuit simulation

This paper presents a coupled simulation approach in the time domain for modeling nonlinear circuits, electromagnetic components, and electromagnetic interference (EMI) interactions together in one integrated methodology. The approach is based on a rigorous coupling of circuit simulation and time-domain integral equation simulation. The method obviates the need for circuit realizations of electromagnetic interactions, and can be considered complementary to the partial element equivalent circuits, for cases where surface-based modeling is preferable such as complex connectors and packages, and for Green's function based modeling of skin effects.
Impedance spectroscopy of PZT ceramics- measuring diffusion coefficients, mixed conduction, and Pb loss

Sintering of lead zirconate titanate (PZT) at high temperatures results in loss of Pb unless an ambient Pb activity is maintained. The tell-tale sign of Pb loss is an increased conductivity, usually manifested in unacceptably high values of tan ?. The conductivity is caused by oxygen vacancies and/or electron holes which are a byproduct of Pb evaporation. In the first part of this paper, it is shown how impedance spectroscopy can be used to separate ionic and electronic conductivity in a properly designed sample by selection of appropriate boundary conditions. Subsequently, impedance is used to probe defect concentrations in PZT during prolonged annealing at 700°C. It is found that oxygen vacancies are generated during annealing in air but the rate of generation actually decreases upon lowering the ambient pO2. These results are explained by a model of Pb evaporation which, in this case, leads predominantly to oxygen vacancy generation. In principle, this effect could be used to generate a specific vacancy concentration in similar Pb-based oxides.
Diverse and widespread contamination evident in the unmapped depths of high throughput sequencing data.

Trace quantities of contaminating DNA are widespread in the laboratory environment, but their presence has received little attention in the context of high throughput sequencing. This issue is highlighted by recent works that have rested controversial claims upon sequencing data that appear to support the presence of unexpected exogenous species. I used reads that preferentially aligned to alternate genomes to infer the distribution of potential contaminant species in a set of independent sequencing experiments. I confirmed that dilute samples are more exposed to contaminating DNA, and, focusing on four single-cell sequencing experiments, found that these contaminants appear to originate from a wide diversity of clades. Although negative control libraries prepared from ‘blank’ samples recovered the highest-frequency contaminants, low-frequency contaminants, which appeared to make heterogeneous contributions to samples prepared in parallel within a single experiment, were not well controlled for. I used these results to show that, despite heavy replication and plausible controls, contamination can explain all of the observations used to support a recent claim that complete genes pass from food to human blood. Contamination must be considered a potential source of signals of exogenous species in sequencing data, even if these signals are replicated in independent experiments, vary across conditions, or indicate a species which seems a priori unlikely to contaminate. Negative control libraries processed in parallel are essential to control for contaminant DNAs, but their limited ability to recover low-frequency contaminants must be recognized.
MCC/SNAr methodology. Part 2: Novel three-step solution phase access to libraries of benzodiazepines

Abstract New developments in the search for novel pharmacological agents over the last decade have focused on the preparation of chemical libraries as sources for new leads for drug discovery. To aid this search a plethora of personal synthesizers and new automation technologies have emerged to help fuel the lead discovery engines of drug discovery organizations. In fact, multi-step solid-phase syntheses of diverse libraries in excess of 10,000 products are now feasible via split and mix techniques. At the same time, a multitude of more efficient, diversity or target oriented solution phase chemical methodologies have appeared in the chemical literature, which have enabled the relatively facile construction of successful lead generation libraries with low FTE input and little capital expenditure. This communication reveals a further application of N -BOC-α-aminoaldehydes in the Ugi condensation reaction, followed by a secondary S N Ar cyclization, accessing arrays of biologically relevant benzodiazepines in good yield and overall purity.
Investigation of the Critical Velocity Required for a Gravity-Stable Surfactant Flood

Classical stability theory predicts the critical velocity for a miscible fluid to be stabilized by gravity forces. This theory was tested for surfactant floods with ultralow interfacial tension (IFT) and was found to be optimistic compared with both laboratory displacement experiments and fine-grid simulations. The inaccurate prediction of instabilities on the basis of available analytical models is because of the complex physics of surfactant floods. First, we simulated vertical sandpack experiments to validate the numerical model. Then, we performed systematic numerical simulations in two and three dimensions to predict formation of instabilities in surfactant floods and to determine the velocity required to prevent instabilities by taking advantage of buoyancy. The 3D numerical grid was refined until the numerical results converged. A third-order total-variation-diminishing (TVD) finite-difference method was used for these simulations. We investigated the effects of dispersion, heterogeneity, oil viscosity, relative permeability, and microemulsion viscosity. These results indicate that it is possible to design a very efficient surfactant flood without any mobility control if the surfactant solution is injected at a low velocity in horizontal wells at the bottom of the geological zone and the oil is captured in horizontal wells at the top of the zone. This approach is practical only if the vertical permeability of the geological zone is high. These experiments and simulations have provided new insight into how a gravity-stable, low-tension displacement behaves and in particular the importance of the microemulsion phase and its properties, especially its viscosity. Numerical simulations show high oil-recovery efficiencies on the order of 60% of waterflood residual oil saturation (ROS) for gravity-stable surfactant floods by use of horizontal wells. Thus, under favorable reservoir conditions, gravity-stable surfactant floods are very attractive alternatives to surfactant/polymer floods. Some of the world’s largest oil reservoirs are deep, high-temperature, high-permeability, light-oil reservoirs, and thus candidates for gravity-stable surfactant floods.
U.S. research joint ventures with international partners

In the United States, as in most industrialized nations, aggregate technological advancement declined during the 1970s and early 1980s. The U.S. Congress was quick to respond to this down turn by passing a number of technology- and innovation-related initiatives, one of which was the National Cooperative Research Act (NCRA) of 1984. It has been argued that this policy response is an example of government acting as entrepreneur because the enabling legislation was both innovative and characterized by entrepreneurial risk. In this paper we examine empirically covariates with the trend in the formation of research joint ventures (RJVs) promulgated by the NCRA and with the probability that a RJV will have an international research partner. We find that RJV formations seem to increase in times when industrial investments in research and development (R&D) decrease, and we conclude that RJVs might thus be a substitute for internal R&D activity. We also find that the probability of a RJV having an international research partner increases as the membership size of the RJV increases. We conclude that as membership size increases, the ability of any one member to appropriate the collective research contributions from the other members, and thus gain a competitive advantage, decreases. Thus, the cost of including in the RJV an international partner, which we argue could represent a potential intellectual capital leakage, decreases.
SELECTIVE CYCLOOXYGENASE INHIBITORS : NOVEL 4-SPIRO 1,2-DIARYLCYCLOPENTENES ARE POTENT AND ORALLY ACTIVE COX-2 INHIBITORS

Abstract Novel 4,5-diarylspiro[2.4]hept-5-enes, 6,7-diarylspiro[3.4]oct-6-enes, and 2,3-diarylspiro[4.4]non-2-enes have been synthesized and shown to be very potent inducible cyclooxygenase (COX-2) inhibitors with inhibition (IC 50 ) in the low nanomolar range and enzyme selectivity ratios as high as four orders of magnitude. The methyl sulfone spiro[2.4]hept-5-ene 1 (SC-58451) was found to be orally active (ED 50 = 0.3 mpk) in the rat adjuvant-induced arthritis model with no gastric lesions observed at 200 mpk.
Perfectly Elastic Axisymmetric Sinusoidal Surface Asperity Contact

This work presents a finite element (FE) study of a perfectly elastic axisymmetric sinusoidal-shaped asperity in contact with a rigid flat for different amplitude to wavelength ratios and a wide range of material properties. This includes characterizing the pressure required to cause complete contact between the surfaces. Complete contact is defined as when there is no gap remaining between two contacting surfaces. The model is designed in such a way that its axisymmetric and interaction with the adjacent asperities are considered by the effect of geometry at the base of the asperity. The numerical results are compared to the model of curved point contact for the perfectly elastic case (known as Hertz contact) and Westergaard's solution. Once properly normalized, the nondimensional contact area does not vary with nondimensional load. The critical pressure required to cause complete contact is found. The results are also curve fitted to provide an expression for the contact area as a function of load over a wide range of cases for use in practical applications, such as to predict contact resistance. This could be a stepping stone to more complex models.
Reading Keynes in Buenos Aires: Prebisch and the Dynamics of Capitalism.

Keynes had a profound influence on Prebisch in terms of the diagnosis about the main failures of market economies and the need to pursue pro-active and anti-cyclical policies. However, Prebisch was critical of some aspects of Keynes’s General Theory of Employment, Interest and Money, in particular on the theory of interest and the multiplier. His attitude can be explained by a difference in the object and method of analysis. Prebisch’s interests focussed on dynamics and the cycle, themes that were peripheral to Keynes’s central message. Prebisch’s Keynesian influence and his rejection of some aspects of Keynes’s magnum opus explains why at the same time that Prebisch is often described as the Latin American Keynes, he is portrayed as concerned mainly with the long-run development problem of Latin America and without proper consideration to demand factors as fundamental determinants of output and employment.
How to Share "A Really Good Secret": Managing Sharing/Secrecy Tensions Around Scientific Knowledge Disclosure

The diffusion of scientific knowledge is critical for innovation, entrepreneurship, and economic growth. Yet scientists face a fundamental dilemma when it comes to sharing such knowledge: sharing can simultaneously advance and challenge both academic and commercial interests. Although several studies explore the different reasons that scientists may or may not share, along with their overall propensity to do so, we have much less insight into how researchers who confront sharing/secrecy tensions attempt to manage them. In turn, our understanding of the ways in which scientists enable cumulative innovation through sharing, even as they attend to their private interests, remains limited. Based on qualitative analysis of 46 interviews and 58 oral histories with researchers in biotechnology and digital audio, I identify 4 tactics that researchers use to manage sharing/secrecy tensions—leveraging trust, strategic withholding, delaying, and patenting—and I analyze how the use of these tactics is tied to particular sharing practices, organizational environments (e.g., universities versus firms), and scientific fields. I then theorize how these tactics address different dimensions of sharing/secrecy tensions, working together as part of an integrated repertoire. Finally, I tie my findings to broader considerations around sharing, including managerial and policy initiatives aimed at promoting cumulative innovation.
On Packing Densities of Set Partitions

We study packing densities for set partitions, which is a generalization of packing words. We use results from the literature about packing densities for permutations and words to provide packing densities for set partitions. These results give us most of the packing densities for partitions of the set {1, 2, 3}. In the final section we determine the packing density of the set partition {{1, 3}, {2}}.
Long-Term Effects of Access to Health Care: Medical Missions in Colonial India

Abstract Health outcomes in India vary substantially across regions. Motivated by mounting evidence of the historical persistence of institutions and behavior, this paper studies the historical origins of this health variation. We examine the long-term consequences of the Protestant medical missionary enterprise that spread throughout India in the nineteenth century. Protestant mission medicine sought to place itself within non-European social and institutional milieus, contributing to the diffusion of Western medicine among the local population. We construct a novel fully geocoded dataset that combines contemporary individual-level data with historical information on missionary activities. We document a robust positive association between proximity to a Protestant medical mission and current individuals' health outcomes. Our analysis indicates that this long-run link is not driven by religious conversion or persistence of infrastructure, but possibly by improvements in individuals' health potential and changes in hygiene and health habits.
The Relationship Between Working Conditions and Musculoskeletal/Ergonomic Disorders in a Manufacturing Facility – A Longitudinal Research Study

Abstract This research investigates the relationship between working conditions and musculoskeletal/ergonomic disorders in a manufacturing facility. I believe that the biomechanical and psychosocial aspects of work have a significant influence on the individual worker's health and well-being. The work organization at which I have evaluated the employee's health and well-being and collected a large amount of data was at a large manufacturing facility. This research is based upon the Balance Theory Model of Smith & Carayon-Sainfort [1] , [2] . The overall purpose of this research study was to identify the stressful working conditions and control them. The overall aim of this research is to improve the long term health and well-being of workers in a manufacturing facility.
Whose and what chatter matters? The effect of tweets on movie sales

Social broadcasting networks such as Twitter in the U.S. and ''Weibo'' in China are transforming the way online word of mouth (WOM) is disseminated and consumed in the digital age. In the present study, we investigated whether and how Twitter WOM affects movie sales by estimating a dynamic panel data model using publicly available data and well-known machine learning algorithms. We found that chatter on Twitter does matter; however, the magnitude and direction of the effect depend on whom the WOM is from and what the WOM is about. Incorporating the number of followers the author of each WOM message had into our study, we found that the effect of WOM from users followed by more Twitter users is significantly larger than those followed by less Twitter users. In support of some recent findings about the importance of WOM valence on product sales, we also found that positive Twitter WOM is associated with higher movie sales, whereas negative WOM is associated with lower movie sales. Interestingly, we found that the strongest effect on movie sales comes from those tweets in which the authors expressed their intention to watch a certain movie. We attribute this finding to the dual effects of such intention tweets on movie sales: the direct effect through the WOM author's own purchase behavior, and the indirect effect through either the awareness effect or the persuasive effect of the WOM on its recipients. Our findings provide new perspectives to understand the effect of WOM on product sales and have important managerial implications. For example, our study reveals the potential values of monitoring people's intentions and sentiments on Twitter and identifying influential users for companies wishing to harness the power of social broadcasting networks.
Pragmatic router FIB caching

Several recent studies have shown that router FIB caching offers excellent hit rates with cache sizes that are an order of magnitude smaller than the original forwarding table. However, hit rate alone is not sufficient - other performance metrics such as memory accesses, robustness to cache attacks, queuing delays from cache misses, etc., should be considered before declaring FIB caching viable.In this paper we tackle several pragmatic questions about FIB caching. We characterize cache performance in terms of memory accesses and delay due to cache misses. We study cache robustness to pollution attacks and show that in order to evict the most popular prefixes an attacker must sustain packet rates higher than the link capacity. We show that caching was robust even during a recent flare of NTP attacks. We carry out a longitudinal study of cache hit rates over four years and show the hit rate is unchanged over that duration. We characterize cache misses to determine which services are impacted by FIB caching. We conclude that FIB caching is viable by several metrics, not just impressive hit rates.
Removal of TcO4− ions from solution: materials and future outlook

Technetium mainly forms during artificial nuclear fission; it exists primarily as TcO4− in nuclear waste, and it is among the most hazardous radiation-derived contaminants because of its long half-life (t1/2 = 2.13 × 105 years) and environmental mobility. The high water solubility of TcO4− (11.3 mol L−1 at 20 °C) and its ability to readily migrate within the upper layer of the Earth's crust make it particularly hazardous. Several types of materials, namely resins, molecular complexes, layered double hydroxides, and pure inorganic and metal–organic materials, have been shown to be capable of capturing TcO4− (or other oxoanions) from solution. In this review, we give a brief description about the types of materials that have been used to capture TcO4− and closely related oxyanions so far and discuss the possibility of using metal–organic frameworks (MOFs) as next-generation ion-exchange materials for the stated application. In particular, with the advent of ultra-stable MOF materials, in conjunction with their chemical tunability, MOFs can be applied to capture these oxyanions under real-life conditions.
Gossip PCA

Eigenvectors of data matrices play an important role in many computational problems, ranging from signal processing to machine learning and control. For instance, algorithms that compute positions of the nodes of a wireless network on the basis of pairwise distance measurements require a few leading eigenvectors of the distances matrix. While eigenvector calculation is a standard topic in numerical linear algebra, it becomes challenging under severe communication or computation constraints, or in absence of central scheduling. In this paper we investigate the possibility of computing the leading eigenvectors of a large data matrix through gossip algorithms.The proposed algorithm amounts to iteratively multiplying a vector by independent random sparsification of the original matrix and averaging the resulting normalized vectors. This can be viewed as a generalization of gossip algorithms for consensus, but the resulting dynamics is significantly more intricate. Our analysis is based on controlling the convergence to stationarity of the associated Kesten-Furstenberg Markov chain.
Prospectively-collected, tooth-specific dosimetry correlated with adverse dental outcomes.

Objectives To correlate radiation dose to specific tooth-bearing portions of bone with adverse dental outcomes. Study Design Eighty-nine patients treated with intensity-modulated radiation therapy with or without chemotherapy had radiation dose to specific tooth-bearing portions of the mandible and the maxilla. Data were collected prospectively during treatment planning, which resulted in 2490 data points. These patients underwent a comprehensive dental intake evaluation that included measurement of pocket depths and were then followed up with serial dental evaluations for a median of 2.5 years (range 0.2–6.9 years). Results At the patient level, the 3-year risks of osteoradionecrosis (ORN) and periodontal disease were 2.5% and 36.6%, respectively. For any individual tooth, the risks of ORN and periodontal disease were 0.1% and 5.1%, respectively, at 3 years. Radiation dose to individual tooth–bearing portions of bone was correlated with ORN development (P = .0165). Periodontal disease also demonstrated a significant, but more gradual, dose response (P = .0395). Conclusions Adverse dental outcomes directly correlate with increased tooth-specific doses.
Pulmonary Morbidity in Infancy after Exposure to Chorioamnionitis in Late Preterm Infants

Rationale: Chorioamnionitis is an important cause of preterm birth, but its impact on postnatal outcomes is understudied.Objectives: To evaluate whether fetal exposure to inflammation is associated with adverse pulmonary outcomes at 6 to 12 months’ chronological age in infants born moderate to late preterm.Methods: Infants born between 32 and 36 weeks’ gestational age were prospectively recruited (N = 184). Chorioamnionitis was diagnosed by placenta and umbilical cord histology. Select cytokines were measured in samples of cord blood. Validated pulmonary questionnaires were administered (n = 184), and infant pulmonary function testing was performed (n = 69) between 6 and 12 months’ chronological age by the raised volume rapid thoracoabdominal compression technique.Measurements and Main Results: A total of 25% of participants had chorioamnionitis. Although infant pulmonary function testing variables were lower in infants born preterm compared with historical normative data for term infants, there were no d...
Stability and spectroscopic properties of singly and doubly charged anions.

Using density functional theory and hybrid B3LYP exchange-correlation energy functional we have studied the structure, stability, and spectroscopic properties of singly and doubly charged anions composed of simple metal atoms (Na, Mg, Al) decorated with halogens such as Cl and pseudohalogens such as CN. Since pseudohalogens mimic the chemistry of halogen atoms, our objective is to see if pseudohalogens can also form superhalogens much as halogens do and if the critical size for a doubly charged anion depends upon the ligand. The electron affinities of MCln (M = Na, Mg, Al) exceed the value of Cl for n ≥ (k + 1), where k is the normal valence of the metal atom. However, for M(CN)n complexes this is only true when n = k + 1. In addition, while the electron affinities and vertical detachment energies of MCln complexes are close to each other, they are markedly different when Cl is replaced by pseudohalogen, CN. The origin of these anomalous results is found to be due to the large binding energy of cyanogen, ...
“Passing the Buck”: Incongruence Between Gender Role and Topic Leads to Avoidance of Negotiation

Avoidance of negotiation is rarely investigated, and the implicit assumption guiding much of the current negotiation research is that engagement is inevitable. In addition, compensation is typically examined, although topics related to both employment and family life are also negotiated in organizations. Two experimental studies tested hypotheses about how incongruence between gender role and negotiation topic influences the likelihood of passing off the negotiation, i.e., ‘‘passing the buck.’’ In study 1, women were significantly more likely to avoid a negotiation about compensation than men, and aversion partially mediated this gender difference. Study 2 revealed a significant two-way interaction between gender and negotiation topic on avoidance. Women were significantly more likely to avoid negotiation about compensation than men; conversely, there was a trend for men to avoid negotiation about access to a lactation room, with the interaction mediated by aversion. The findings underscore the importance of both negotiation topics and avoidance.
Cannibalization and option value effects of secondary markets: : Evidence from the US concert industry

We examine how reducing search frictions in secondary markets affects the value appropriated by firms in primary markets. We characterize two effects on primary-market firms caused by intermediaries entering secondary markets: the “cannibalization” and “option value” effects. Separation between primary and secondary markets can drive which of the two effects dominates. Firms selling valuable and scarce products are more likely to have separate primary and secondary markets, and will therefore appropriate more value when secondary markets thicken. Firms selling products that are not valuable and scarce will be hurt. Further, we hypothesize that firms have incentives to engineer scarcity by limiting supply when secondary markets thicken to separate primary and secondary markets. We find support for these hypotheses in the U.S. concert ticket industry. Copyright © 2014 John Wiley & Sons, Ltd.
Silica sulfuric acid as a highly efficient catalyst for the synthesis of diarylacetic acids

ABSTRACTAn efficient heterogeneous method for the synthesis of diarylacetic acids was developed utilizing silica sulfuric acid as a catalyst. The reaction is highly efficient with a small amount of catalyst for the combination of a variety of electron-neutral to electron-rich arenes with glyoxylic acid. The reaction can also be utilized to synthesize unsymmetric derivatives from activated mandelic acids in good to excellent yields.
A Representation Theorem for General Revealed Preference

Following Richter (1966), we provide criteria under which a preference relation implied by a finite set of choice observations has a complete extension that can in turn be represented by a utility function. These criteria rely on a mapping over preference relations, the rational closure, which is a generalization of the transitive closure and is employed to construct the complete extension. We illustrate this approach by revisiting the problem of rationalizing incomplete preferences revealed by a sequence of consumption decisions under different budget sets. Our result relaxes the usual assumptions about the consumption space and the structure of budgets generating the observed choices, and allows for a new interpretation of classical revealed preference axioms.
Leaking modes and the PL phase

ABSTRACT The PL phase is a normally dispersed train of waves of periods greater than about 10 seconds beginning at or near the time of the initial P wave and sometimes continuing at least to the time of the beginning of the Rayleigh-wave train. With adequate instrumentation the PL phase is commonly observed at distances less than about 25° from shallow shocks. In general, surface particle motion is elliptical and progressive, and amplitudes are not greater than about one-quarter those of Rayleigh waves of the same period. Comparison of PL- and Rayleigh-wave dispersion shows that both waves propagate in roughly the same near-surface wave guide. Whereas Rayleigh waves correspond to normal- (nonleaking-) mode propagation, PL waves appear to correspond to leakingmode propagation within this wave guide.
Technological Change and Reallocation

This paper considers a technological change that can be utilized only by production units adapting to the new technology. A simple firm dynamics model is used to show such an innovation enhances reallocation, whereas a technological advance that is available to all production units does not. This implication is used in structural vector autoregressions to study the driving force behind cyclical movements in reallocation and the rival/nonrival nature of technology. This paper finds that technology shocks fostering an ongoing reallocation are responsible for a large portion of economic fluctuations, confirming a rival or Schumpeterian nature of technological progress.
Perceptual Regression In Schizophrenia An Hypothesis Suggested By the Use of the Rorschach Test

(1953). Perceptual Regression In Schizophrenia An Hypothesis Suggested By the Use of the Rorschach Test. Journal of Projective Techniques: Vol. 17, No. 2, pp. 171-185.
The universal ureteral stent.

Abstract: The universal ureteral stent is an 8F soft silicone rubber tube 90cm. long with a zone of side holes marked with radiopaque material. This stent does not cause the discomfort associated with other ureteral stents and can provide immediate nephrostomy drainage if obstruction occurs. The universal stent is reasonably priced, and because only 1 size stent is needed, which has several applications, the size and cost of hospital stent inventories should be decreased.
Distributed feedback oscillation in ordered colloidal suspensions of polystyrene microspheres

Previous experiments on the transmission properties of ordered nondispersive suspensions of negatively charged latex spheres in water suggested the use of such host materials for the realization of distributed feedback laser emission in these novel systems.1
Differentially private grids for geospatial data

We tackle the problem of constructing a differentially private synopsis for two-dimensional datasets such as geospatial datasets. The current state-of-the-art methods work by performing recursive binary partitioning of the data domains, and constructing a hierarchy of partitions. We show that the key challenge in partition-based synopsis methods lies in choosing the right partition granularity to balance the noise error and the nonuniformity error. We study the uniform-grid approach, which applies an equi-width grid of a certain size over the data domain and then issues independent count queries on the grid cells. This method has received no attention in the literature, probably due to the fact that no good method for choosing a grid size was known. Based on an analysis of the two kinds of errors, we propose a method for choosing the grid size. Experimental results validate our method, and show that this approach performs as well as, and often times better than, the state-of-the-art methods. We further introduce a novel adaptive-grid method. The adaptive grid method lays a coarse-grained grid over the dataset, and then further partitions each cell according to its noisy count. Both levels of partitions are then used in answering queries over the dataset. This method exploits the need to have finer granularity partitioning over dense regions and, at the same time, coarse partitioning over sparse regions. Through extensive experiments on real-world datasets, we show that this approach consistently and significantly outperforms the uniform grid method and other state-of-the-art methods.
Understanding Jupiter's interior

This article provides an overview of how models of giant planet interiors are constructed. We review measurements from past space missions that provide constraints for the interior structure of Jupiter. We discuss typical three-layer interior models that consist of a dense central core and an inner metallic and an outer molecular hydrogen-helium layer. These models rely heavily on experiments, analytical theory, and first-principle computer simulations of hydrogen and helium to understand their behavior up to the extreme pressures ∼10 Mbar and temperatures ∼10 000 K. We review the various equations of state used in Jupiter models and compare them with shock wave experiments. We discuss the possibility of helium rain, core erosion and double diffusive convection may have important consequences for the structure and evolution of giant planets. In July 2016 the Juno spacecraft entered orbit around Jupiter, promising high-precision measurements of the gravitational field that will allow us to test our understanding of gas giant interiors better than ever before.
Estimation of Signal Parameters via Rotational Invariance Techniques- ESPRIT

A new approach to the general problem of signal parameter estimation is described. Though the technique ESPRIT is discussed in the context of direction-of arrival estimation, it can be applied to a wide variety of problems including spectral estimation. ESPRIT exploits an underlying rotational invariance among signal subspaces induced by an array of sensors with a translational in variance structure (e.g., pairwise matched and co-directional antenna element doublets) and has several advantages over earlier techniques such as MUSIC including improved performance, reduced computational load, freedom from array characterization calibration, and reduced sensitivity to array perturbations. Results of computer simulations carried out to evaluate the new algorithm arc presented.
The Dynamics of Domestic Gray Markets and Its Impact on Supply Chains

Gray markets are created by unauthorized retailers selling manufacturer's branded products. Similar to international gray markets, domestic gray markets are a growing phenomenon whose impact on supply chains is not clear. We consider a supply chain with one manufacturer and several authorized retailers who face a newsvendor problem and a domestic gray market. While a gray market provides an opportunity for retailers to clear their excess inventory (inventory-correction effect), it also can be a threat to their demand (demand-cannibalization effect). We first characterize the emerging equilibrium by assuming an MSRP environment. Comparing a decentralized and centralized system, we show that a wholesale pricing contract is quite efficient in a gray market environment; we explain the underlying mechanism and note some of the operational decisions that could hurt that efficiency. We show that the gray market price determines the degree of both the negative effects of demand-cannibalization and the positive effects of inventory correction, which in turn determines the net impact of gray markets on the retailer's stocking choice and, ultimately, the manufacturer's profit. We then study the authorized retailers’ problem as a price-setting newsvendor. We observe that the gray market creates price competition between the authorized and unauthorized retailers, causing a drop in the primary market price. However, this price competition can be counteracted by the authorized retailers’ stocking decision. Finally, we extend our model to consider the cases where the demand can be correlated across retailers. This article is protected by copyright. All rights reserved.
Supporting Mathematical Discussions: the Roles of Comparison and Cognitive Load

Mathematical discussions in which students compare alternative solutions to a problem can be powerful modes for students to engage and refine their misconceptions into conceptual understanding, as well as to develop understanding of the mathematics underlying common algorithms. At the same time, these discussions are challenging to lead effectively, in part because they involve complex cognitive acts of identifying structural relationships within multiple solutions and comparing between these sets of relationships. While many of the considerations in leading such discussions have been described elsewhere, we highlight the cognitive challenges for students and the core role of relational reasoning that underpins student learning from these interactions. We review the literature on children’s development of relational reasoning and learning from comparisons to highlight particular challenges for students. We also review literature that suggests pedagogical practices for maximizing the likelihood that children will notice the intended relationships among solutions while minimizing overload to their cognitive resources. These practices include providing explicit comparison cues and labels, sequencing comparison before explicit instruction, using spatially aligned visual representations, and capitalizing on teacher gestures.
Fusion Ignition Research Experiment System Integration

This paper describes the current status of the FIRE (Fusion Ignition Research Experiment) configuration and the integration of the major subsystem components. FIRE has a major radius of 2 m, a field on axis of 10T, a plasma current of 6.4 MA. It is capable of 18-second pulses when operated with DT and 26 s when operated with DD. The general arrangement consists of sixteen wedged TF (toroidal field) coils that surround a free standing central solenoid, a double wall vacuum vessel and internal plasma facing components that are segmented for maintenance through horizontal ports. Large rings located outside the TF coils are used to obtain a load balance between wedging of the intercoil case structure and wedging at the upper/lower inboard corners of the TF coil winding. The magnets are liquid nitrogen cooled and the entire device is surrounded by a thermal enclosure. The double wall vacuum vessel integrates cooling and shielding in a shape that maximizes shielding of ex-vessel components. Within the vacuum vessel, plasma-facing components frame the plasma. First wall tiles are attached directly to inboard and outboard vacuum vessel walls. The divertor is designed for a high triangularity, double-null plasma with a short inner null point-to-wall distance and near vertical outer divertor flux line. The FIRE configuration has been developed to meet the physics objectives and subsystem requirements in an arrangement that allows remote maintenance of in-vessel components and hands-on maintenance of components outside the TF boundary.
Development of destination choice models for pedestrian travel

Abstract Most research on walking behavior has focused on mode choice or walk trip frequency. In contrast, this study is one of the first to analyze and model the destination choice behaviors of pedestrians within an entire region. Using about 4500 walk trips from a 2011 household travel survey in the Portland, Oregon, region, we estimated multinomial logit pedestrian destination choice models for six trip purposes. Independent variables included terms for impedance (walk trip distance), size (employment by type, households), supportive pedestrian environments (parks, a pedestrian index of the environment variable called PIE), barriers to walking (terrain, industrial-type employment), and traveler characteristics. Unique to this study was the use of small-scale destination zone alternatives. Distance was a significant deterrent to pedestrian destination choice, and people in carless or childless households were less sensitive to distance for some purposes. Employment (especially retail) was a strong attractor: doubling the number of jobs nearly doubled the odds of choosing a destination for home-based shopping walk trips. More attractive pedestrian environments were also positively associated with pedestrian destination choice after controlling for other factors. These results shed light on determinants of pedestrian destination choice behaviors, and sensitivities in the models highlight potential policy-levers to increase walking activity. In addition, the destination choice models can be applied in practice within existing regional travel demand models or as pedestrian planning tools to evaluate land use and transportation policy and investment scenarios.
ARTHROSCOPY OF THE PAINFUL THA: OF ANY VALUE?

Unexplained pain after hip arthroplasty is frustrating for patients and surgeons. The purpose of this study was 1. to describe the use of hip arthroscopy in management of the painful hip arthroplasty, 2. to critically evaluate the outcomes these patients, and 3. to help define indications for hip arthroscopy in this setting. We retrospectively reviewed 14 patients (16 hips) who underwent hip arthroscopy after joint replacement. One patient had suspected septic arthritis despite negative aspiration and one had known septic arthritis but was not a candidate for open arthrotomy; two had intra-articular migration of hardware. The remaining 10 patients (11 hips) had persistent pain despite negative diagnostic studies. The two patients (two hips) with infection were successfully treated with arthroscopic lavage and debridement plus intravenous antibiotics. Intra-articular metal fragments and a loose acetabular screw were successfully removed in two patients (three hips). Findings in remaining the 11 hips included a loose acetabular component (one); corrosion at the head-neck junction of a metal-on-metal articulation (one); soft tissue-scar impingement at the head cup interface (four); synovitis with associated scar tissue (four); and capsular scarring with adhesions (one). Arthroscopy represented a successful treatment or directly led to a successful treatment in 12 of 16 hips. We observed no complications as a result of the arthroscopy. Arthroscopy may be of value in selected patients