cssi/SciSciGPT-SciSciNet huggingface dataset:
Political Equality, the Internet, and Campaign Finance Regulation

Despite signs from the 2004 presidential election contest pointing to a larger role for “big money” in the 2008 season, the indicia so far suggest that there is much for egalitarians to cheer. Egalitarians believe that unequal distribution of wealth should play less of a role in determining presidential election outcomes and/or the policies of the president once elected. At this point in the 2008 election season, it appears that big money is beginning to matter less, rather than more, thanks in large part to the enhanced role of the Internet in campaigning and fundraising, and especially thanks to the viability of campaigns funded substantially by small donors. Such a shift is especially important given that the United States Supreme Court has grown increasingly hostile to campaign finance regulation. The promise of small donors, rather than regulation, stands the best chance of countering the role of big money in future presidential elections.
Atomic-scale images of charge ordering in a mixed-valence manganite

Transition-metal perovskite oxides exhibit a wide range of extraordinary but imperfectly understood phenomena. The best known examples are high-temperature superconductivity in copper oxides1, and colossal magnetoresistance in manganese oxides (‘manganites’)2,3. All of these materials undergo a range of order–disorder transitions associated with changes in charge, spin, orbital and lattice degrees of freedom. Measurements of such order are usually made by diffraction techniques, which detect the ionic cores and the spins of the conduction electrons. Unfortunately, because such techniques are only weakly sensitive to valence electrons and yield superpositions of signals from distinct submicrometre-scale phases, they cannot directly image phase coexistence and charge ordering, two key features of the manganites. Here we present scanning tunnelling microscope measurements of the manganite Bi1-xCaxMnO3. We show that charge ordering and phase separation can be resolved in real space with atomic-scale resolution. By taking together images and current–voltage spectroscopy data we find that charge order correlates with both structural order and the local conductive state (either metallic or insulating). These experiments provide an atomic-scale basis for descriptions4 of manganites as mixtures of electronically and structurally distinct phases.
Is the Falling Rate of Profit the Driving Force Behind Globalization

This paper examines critically the role of the law of the tendency of the falling rate of profit in the geographic expansion (globalization) of competitive capitalism. It contends that Marx did not believe there was an iron-clad connection between the falling rate of profit and globalization; in addition, it argues that Marx believed that the capitalists’ insatiable search for colonial markets was driven by their desire to overcome recurrent (and growing) realization problems in the home market arising from deficient aggregate demand on the part of both workers and capitalists. (This abstract was borrowed from another version of this item.)
2D Kac-Moody Symmetry of 4D Yang-Mills Theory

Scattering amplitudes of any four-dimensional theory with nonabelian gauge groupG may be recast as two-dimensional correlation functions on the asymptotic two-sphere at null innity. The soft gluon theorem is shown, for massless theories at the semiclassical level, to be the Ward identity of a holomorphic two-dimensionalG-Kac-Moody symmetry acting on these correlation functions. Holomorphic Kac-Moody current insertions are positive helicity soft gluon insertions. The Kac-Moody transformations are a CPT invariant subgroup of gauge transformations which act nontrivially at null innity and comprise the four-dimensional asymptotic symmetry group.
SHORTEST PATHS AMONG OBSTACLES IN THE PLANE

We give a subquadratic (O(n3/2+∊) time and O(n) space) algorithm for computing Euclidean shortest paths in the plane in the presence of polygonal obstacles; previous time bounds were at least quadratic in n, in the worst case. The method avoids use of visibility graphs, relying instead on the continuous Dijkstra paradigm. The output is a shortest path map (of size O(n)) with respect to a given source point, which allows shortest path length queries to be answered in time O(log n). The algorithm extends to the case of multiple source points, yielding a method to compute a Voronoi diagram with respect to the shortest path metric.
ROBUST PERMANENT INCOME AND PRICING WITH FILTERING

A planner and agent in a permanent-income economy cannot observe part of the state, regard their model as an approximation, and value decision rules that are robust across a set of models. They use robust decision theory to choose allocations. Equilibrium prices reflect the preference for robustness and so embody a “market price of Knightian uncertainty.” We compute market prices of risk and compare them with a model that assumes that the state is fully observed. We use detection error probabilities to constrain a single parameter that governs the taste for robustness.
Which protocol? mutual interaction of heterogeneous congestion controllers

A large number of congestion control protocols have been proposed in the last few years, with all having the same purpose--to divide available bandwidth resources among different flows in a fair manner. Each protocol operates on the paradigm of some conception of link price (such as packet losses or packet delays) that determines source transmission rates. Recent work on network utility maximization has brought forth the idea that the fundamental price or Lagrange multiplier for a link is proportional to the queue length at that link, and that different congestion metrics (such as delays or drops) are essentially ways of interpreting such a Lagrange multiplier. We thus ask the following question: Suppose that each flow has a number of congestion control protocols to choose from, which one (or combination) should it choose? We introduce a framework wherein each flow has a utility that depends on throughput and also has a disutility that is some function of the queue lengths encountered along the route taken. Flows must choose a combination of protocols that would maximize their payoffs. We study both the socially optimal, as well as the selfish cases to determine the loss of system-wide value incurred through selfish decision making, so characterizing the "price of heterogeneity." We also propose tolling schemes that incentivize flows to choose one of several different virtual networks catering to particular needs and show that the total system value is greater, hence making a case for the adoption of such virtual networks.
Aeroelastic coupling of geometrically nonlinear structures and linear unsteady aerodynamics: Two formulations

Two different time domain formulations of integrating commonly used frequency-domain unsteady aerodynamic models based on a modal approach with full order finite element models for structures with geometric nonlinearities are presented. Both approaches are tailored to flight vehicle configurations where geometric stiffness effects are important but where deformations are moderate, flow is attached, and linear unsteady aerodynamic modeling is adequate, such as low aspect ratio wings or joined-wing and strut-braced wings at small to moderate angles of attack. Results obtained using the two approaches are compared using both planar and non-planar wing configurations. Sub-critical and post-flutter speeds are considered. It is demonstrated that the two methods lead to the same steady solution for the sub-critical case after the transients subside. It is also shown that the two methods predict the amplitude and frequency of limit cycle oscillation (when present) with the same accuracy.
Mean and Covariance Structure Analysis: Theoretical and Practical Improvements

Abstract The most widely used multivariate statistical models in the social and behavioral sciences involve linear structural relations among observed and latent variables. In practice, these variables are generally nonnormally distributed; hence classical multivariate analysis, based on multinomial error-free variables having no simultaneous interrelations, is not adequate to deal with such data. A promising alternative, based on asymptotically distribution-free (ADF) covariance structure analysis, has been found to be virtually useless in practical model evaluation at finite sample sizes with nonnormal data. We take a new look at the basic statistical theory of structural models under arbitrary distributions, using the methodology of nonlinear regression and generalized least squares estimation. For example, we adopt the use of residual weight matrices from regression theory. We develop a series of estimators and tests based on arbitrary distribution theory. We obtain a type of probabilistic Bartlett co...
Immigrants, English Ability and the Digital Divide

This study examines the extent and causes of inequalities in information technology ownership and use between natives and immigrants in the United States, with particular focus on the role of English ability. The results indicate that, during the period 1997 2003, immigrants were significantly less likely to have access to or use a computer and the Internet. Moreover, the gap in IT usage widened during that period. Immigrants and natives who live in Spanish-speaking households are less likely than individuals living in English-speaking households to have access to or use IT. Estimates using a measure of predicted English ability show that English ability is positively associated with IT access and use. The results suggest that much of the immigrant-native gap in IT usage is attributable to differences in English ability.
The product/process distinction - an illusory basis for disciplining 'unilateralism' in trade policy

It has become conventional wisdom that internal regulations that distinguish between products on the basis of their production method are GATT-illegal, where applied to restrict imports (although possibly some such measures might be justified as 'exceptions' under Article XX). The aim of this article is to challenge this conventional wisdom, both from a jurisprudential and a policy perspective. First, we argue there is no real support in the text and jurisprudence of the GATT for the product/process distinction. The notion developed in the unadopted Tuna/Dolphin cases that processed-based measures are somehow excluded from the coverage of Article III (National Treatment) and are therefore violations of Article XI (quantitative restrictions) is inconsistent with the text of this provision and the basic structure of the GATT. The real question is whether, under the National Treatment standard of Article III, products may be considered 'unlike' due to process-based differences. We argue that regulatory distinctions objectively related to actual non-protectionist policies are consistent with Article III, whether product- or process-based. The second half of the article addresses a range of policy concerns about treating process-based measures similarly to product-based measures under Article III. One concern is based on the conflation of process-based measures with measures that distinguish products not according to how they are actually produced, but rather according to their country of origin. We believe that country-based measures are likely to be violations of Article III and/or Article I of the GATT,
The Phantom Bounce: A New Proposal for an Oscillating Cosmology

An oscillating universe cycles through a series of expansions and contractions. We propose a model in which phantom energy with a supernegative pressure (p) grows rapidly and dominates the late-time expanding phase. The universes energy density is then so large that the effects of quantum gravity are important at both the beginning and the end of each expansion (or contraction). The bounce can be caused by high energy modifications to the Friedmann equation governing the expansion of the universe, which make the cosmology nonsingular. The classic black hole overproduction of oscillating universes is resolved due to their destruction by the phantom energy.
Development of Friction Drive Transmission

A cylindrical friction drive was developed for electric oil pump applications. It was comprised of an outer ring a sun roller, a loading planet two supporting planets, and a stationary carrier. The sun roller was set eccentric to the outer ring to generate a wedge gap that facilitates a torque actuated loading mechanism for the friction drive. The loading planet was properly assembled in the wedge gap and elastically supported to the carrier. By altering the stiffness ratio of the elastic support to contact, the actual operating friction coefficient of the friction drive can be changed regardless of the wedge angle to suit for performance requirement. This provided a greater freedom for design and performance optimization. Design analysis was presented and a FE model was developed to quantify design parameters. Prototypes of the friction drive were fabricated and extensive testing was conducted to evaluate its performance. Results indicated the performance of the friction drive for exceeded the design specifications in speed, torque. and power ratings. The friction drive offered a consistent smooth and quiet performance over a wide range of operating conditions. It was capable of operating at an elevated speed of up to 12 000 rpm with adequate thermal characteristics. The friction drive demonstrated a peak efficiency above 97%. Results confirmed that the stiffness of the elastic support has an important impact on performance. The elastic support stiffness, in conjunction with the contact stiffness, determines the actual operating friction coefficient at the frictional contacts.
Contractual form and market thickness in trucking

A central proposition of the transaction costs literature is that firms will substitute more complicated contractual arrangements for simple spot arrangements when transactions involve relationship-specific investments. I investigate this proposition by testing whether simple spot arrangements are less common when local trucking markets are thin. I find that doubling the thickness of the market increases the likelihood that simple spot arrangements govern transactions by about 30% for long hauls. I find weaker evidence of relationships between local market thickness and contractual form for short hauls—hauls for which quasi-rents are particularly small. Contracts protect quasi-rents over a surprisingly large range, but they play a less important role as quasi-rents decrease.
Cypiripi: exact genotyping of CYP2D6 using high-throughput sequencing data.

Motivation: CYP2D6 is highly polymorphic gene which encodes the (CYP2D6) enzyme, involved in the metabolism of 20–25% of all clinically prescribed drugs and other xenobiotics in the human body. CYP2D6 genotyping is recommended prior to treatment decisions involving one or more of the numerous drugs sensitive to CYP2D6 allelic composition. In this context, high-throughput sequencing (HTS) technologies provide a promising time-efficient and cost-effective alternative to currently used genotyping techniques. To achieve accurate interpretation of HTS data, however, one needs to overcome several obstacles such as high sequence similarity and genetic recombinations between CYP2D6 and evolutionarily related pseudogenes CYP2D7 and CYP2D8, high copy number variation among individuals and short read lengths generated by HTS technologies. Results: In this work, we present the first algorithm to computationally infer CYP2D6 genotype at basepair resolution from HTS data. Our algorithm is able to resolve complex genotypes, including alleles that are the products of duplication, deletion and fusion events involving CYP2D6 and its evolutionarily related cousin CYP2D7. Through extensive experiments using simulated and real datasets, we show that our algorithm accurately solves this important problem with potential clinical implications. Availability and implementation: Cypiripi is available at http://sfu-compbio.github.io/cypiripi. Contact: cenk@sfu.ca.
Percutaneous Angioscopy: Methodological Considerations

The development of angioscopy has resulted in a variety of approaches and equipment, all with the fundamental purpose of looking inside the cardiovascular system. In this paper, the variations in design of commercially available angioscopes are discussed, along with the differences in methods of introduction into the patient, balloon placement, and steering capabilities. Finally, suggestions are made for the design of future angioscopic devices that would provide more usable units for clinical studies.
Cancer in the older person

The incidence and mortality rate of cancer increases with age. With a worldwide increase in life expectancy, the clinical problems associated with cancer and old age are becoming more and more widespread. The clinical questions relating to cancer and old age can be divided into three main areas: 1) Why does the incidence and prevalence of cancer increase with age? 2) Does age affect the biology of cancer? 3) Is the prevention and treatment of cancer beneficial to elderly patients? 4) What are the psychosocial consequences of treating elderly patients with cancer?
An oxidatively releasable caging group that senses lipid peroxidation.

Abstract A new radical-sensitive caging technique releases a caged molecule under lipid peroxidation conditions. In a competitive oxidation study with a model lipid, methyl linoleate, the oxidatively releasable xanthenyl caging groups is found to be 1.93 ± 0.55 times more reactive than the lipid model compound.
Synthesis and crystal structure of barium thioborate Ba7(BS3)4S.

The thioborate phase Ba7(BS3)4S was synthesized from solid state reaction and its crystal structure determined by single crystal X-ray diffraction analysis. It crystallizes in the monoclinic space ...
The World Trade Organization and Participatory Democracy: The Historical Evidence

Although the World Trade Organization (WTO) is one of the most significant international institutions, its function, domain, and legitimacy are still heavily contested. The Author examines the history of the founding of the General Agreement on Tariffs and Trade (GATT), the WTO's predecessor, to see what history reveals about the role that GATT was originally expected to fulfill. The Author's interpretive examination shows that GATT's founders recognized that trade policy must be internationalized in order to give one country an opportunity to participate in the policy-mahing of other countries; otherwise, a county can impose costs on other countries without representation from those countries. This review therefore supports the vision of the WTO as an institution of international participatory democracy; suggests that the WTO is a political, not just an economic institution; and rebuts the notion that the domain of the WTO is limited to helping countries overcome protectionist interests at home. * Professor of Law, Case Western Reserve University School of Law. The Author thanks Rick Gambs, '06, for his valuable research assistance and advice.
Time-Space Tradeoffs for Counting NP Solutions Modulo Integers

We prove the first time-space tradeoffs for counting the number of solutions to an NP problem modulo small integers, and also improve upon known time-space tradeoffs for Sat. Let m > 0 be an integer, and define MOD m -Sat to be the problem of determining if a given Boolean formula has exactly km satisfying assignments, for some integer k. We show for all primes p except for possibly one of them, and for all c 0 such that MOD p -Sat is not solvable in n c time and n d space by general algorithms. That is, there is at most one prime p that does not satisfy the tradeoff. We prove that the same limitation holds for Sat and MOD 6-Sat, as well as MOD m -Sat for any composite m that is not a prime power. Our main tool is a general method for rapidly simulating deterministic computations with restricted space, by counting the number of solutions to NP predicates modulo integers. The simulation converts an ordinary algorithm into a "canonical" one that consumes roughly the same amount of time and space, yet canonical algorithms have nice properties suitable for counting.
Classifying characteristic functions giving Weyl-Heisenberg frames

We examine the question of which characteristic functions yield Weyl-Heisenberg frames for various values of the parameters. We also give numerous applications of frames of characteristic functions to the general case (g, a, b).
DNA-guided establishment of nucleosome patterns within coding regions of a eukaryotic genome

A conserved hallmark of eukaryotic chromatin architecture is the distinctive array of well-positioned nucleosomes downstream from transcription start sites (TSS). Recent studies indicate that trans-acting factors establish this stereotypical array. Here, we present the first genome-wide in vitro and in vivo nucleosome maps for the ciliate Tetrahymena thermophila. In contrast with previous studies in yeast, we find that the stereotypical nucleosome array is preserved in the in vitro reconstituted map, which is governed only by the DNA sequence preferences of nucleosomes. Remarkably, this average in vitro pattern arises from the presence of subsets of nucleosomes, rather than the whole array, in individual Tetrahymena genes. Variation in GC content contributes to the positioning of these sequence-directed nucleosomes and affects codon usage and amino acid composition in genes. Given that the AT-rich Tetrahymena genome is intrinsically unfavorable for nucleosome formation, we propose that these "seed" nucleosomes--together with trans-acting factors--may facilitate the establishment of nucleosome arrays within genes in vivo, while minimizing changes to the underlying coding sequences.
Torquewhirl - A theory to explain nonsynchronous whirling failures of rotors with high load torque

Numerous unexplained failures of rotating machinery by nosynchronous shaft whirling point to a possible driving mechanism or source of energy not identified by previously existing theory. A majority of these failures have been in machines characterized by overhung disks (or disks located close to one end of a bearing span) and/or high horse power and load torque. This paper gives exact solutions to the nonlinear differential equations of motion for a rotor having both of these characteristics, and shows that high ratios of driving torque to damping can produce nonsynchronous whirling with destructively large amplitudes. Solutions are given for two cases: (1) viscous load torque and damping, and (2) load torque and damping proportional to the second power of velocity (aerodynamic case). Linearized coefficients for stability analyses are derived for a special case. Criteria are given for avoiding the torquewhirl condition.
Optical loss analysis of monolithic perovskite/Si tandem solar cell

Coupling perovskite and silicon solar cells in a tandem configuration is considered an attractive method to increase conversion efficiency beyond the single-junction Shockley-Queisser limit. While a mechanically-stacked perovskite/silicon tandem solar cell has been demonstrated, a method to electrically couple perovskite and silicon solar cell in a monolithic configuration has not been demonstrated. In this contribution, we design and demonstrate a working monolithic perovskite/silicon tandem solar cell, enabled by a silicon tunnel junction, with a VOC of 1.58 V. We further discuss possible efficiency loss mechanisms and mitigation strategies.
Combinations of coupled cluster, density functionals, and the random phase approximation for describing static and dynamic correlation, and van der Waals interactions

ABSTRACTContrary to standard coupled cluster doubles (CCD) and Brueckner doubles (BD), singlet-paired analogues of CCD and BD (denoted here as CCD0 and BD0) do not break down when static correlation is present, but neglect substantial amounts of dynamic correlation. In fact, CCD0 and BD0 do not account for any contributions from multielectron excitations involving only same-spin electrons at all. We exploit this feature to add – without introducing double counting, self-interaction, or increase in cost – the missing correlation to these methods via meta-GGA (generalised gradient approximation) density functionals (Tao–Perdew–Staroverov–Scuseria and strongly constrained and appropriately normed). Furthermore, we improve upon these CCD0+DFT blends by invoking range separation: the short- and long-range correlations absent in CCD0/BD0 are evaluated with density functional theory and the direct random phase approximation, respectively. This corrects the description of long-range van der Waals forces. Comprehe...
Hawking from Catalan

The Virasoro algebra determines all ‘graviton’ matrix elements in AdS3/CFT2. We study the explicit exchange of any number of Virasoro gravitons between heavy and light CFT2 operators at large central charge. These graviton exchanges can be written in terms of new on-shell tree diagrams, organized in a perturbative expansion in h H /c, the heavy operator dimension divided by the central charge. The Virasoro vacuum conformal block, which is the sum of all the tree diagrams, obeys a differential recursion relation generalizing that of the Catalan numbers. We use this recursion relation to sum the on-shell diagrams to all orders, computing the Virasoro vacuum block. Extrapolating to large h H /c determines the Hawking temperature of a BTZ black hole in dual AdS3 theories.
In search of ideas: Technological innovation and executive pay inequality

Abstract We develop a general equilibrium model that delivers realistic fluctuations in pay inequality as a result of changes in the technology frontier. In our model, executives add value to the firm not only by participating in production decisions, as do other workers in the economy, but also by identifying new investment opportunities. Improvements in technology that are specific to new vintages of capital raise the return to managers’ skills for discovering new growth projects and, thus, increase the compensation of executives relative to workers and disparities in pay across executives. Our model implies that, controlling for firm size, compensation is higher in fast-growing firms and that pay inequality increases as investment opportunities in the economy improve. Both predictions are consistent with the data.
The Covering Radius of Randomly Distributed Points on a Manifold

We derive fundamental asymptotic results for the expected covering radius ρ(XN) for N points that are randomly and independently distributed with respect to surface measure on a sphere as well as on a class of smooth manifolds. For the unit sphere Sd ⊂Rd+1, we obtain the precise asymptotic that Eρ(XN)[N/ log N]1/d has limit [(d+ 1)υd+1/υd] as N →∞, where υd is the volume of the d-dimensional unit ball. This proves a recent conjecture of Brauchart et al. as well as extends a result previously known only for the circle. Likewise, we obtain precise asymptotics for the expected covering radius of N points randomly distributed on a d-dimensional ball, a d-dimensional cube, as well as on a three-dimensional polyhedron (where the points are independently distributed with respect to volume measure). More generally, we deduce upper and lower bounds for the expected covering radius of N points that are randomly and independently distributed on a compact metric measure space, provided the measure satisfies certain regularity assumptions.
A 3.4 V Layered VOPO4 Cathode for Na-Ion Batteries

Vanadyl phostate (VOPO4) with a layered structure was successfully prepared by chemical delithiation of the tetragonal αI-LiVOPO4 at room temperature. X-ray diffraction (XRD) studies show the resulting VOPO4 has a crystal structure similar to αI-LiVOPO4. The V4+/V5+ redox couple exhibits a discharge plateau around 3.5 V vs Na/Na+ in sodium cells. The sample offers a capacity of ∼110 mAh g–1 (0.67 Na+) without any conductive coating and ∼150 mAh g–1 (0.90 Na+) with a preliminary optimization with reduced graphene oxide (rGO) nanosheets. The electrochemically sodiated VOPO4 electrodes show XRD patterns similar to the chemically sodiated VOPO4, indicating the formation of the same product by the two sodiation processes. Bond valence sum (BVS) map calculations suggest that sodium ions likely take the sites between two adjacent VOPO4 sheets. Rietveld refinement of the chemically sodiated Na0.8VOPO4 indicate that the sodium ions could take the 8j sites similar to the lithium ions in αI-LiVOPO4. This new layered...
An Automaton Learning Approach to Solving Safety Games over Infinite Graphs

We propose a method to construct finite-state reactive controllers for systems whose interactions with their adversarial environment are modeled by infinite-duration two-player games over possibly infinite graphs. The method targets safety games with infinitely many states or with such a large number of states that it would be impractical--if not impossible--for conventional synthesis techniques that work on the entire state space. We resort to constructing finite-state controllers for such systems through an automata learning approach, utilizing a symbolic representation of the underlying game that is based on finite automata. Throughout the learning process, the learner maintains an approximation of the winning region represented as a finite automaton and refines it using different types of counterexamples provided by the teacher until a satisfactory controller can be derived if one exists. We present a symbolic representation of safety games inspired by regular model checking, propose implementations of the learner and teacher, and evaluate their performance on examples motivated by robotic motion planning.
Emerging Frontiers in Drug Delivery

Medicine relies on the use of pharmacologically active agents (drugs) to manage and treat disease. However, drugs are not inherently effective; the benefit of a drug is directly related to the manner by which it is administered or delivered. Drug delivery can affect drug pharmacokinetics, absorption, distribution, metabolism, duration of therapeutic effect, excretion, and toxicity. As new therapeutics (e.g., biologics) are being developed, there is an accompanying need for improved chemistries and materials to deliver them to the target site in the body, at a therapeutic concentration, and for the required period of time. In this Perspective, we provide an historical overview of drug delivery and controlled release followed by highlights of four emerging areas in the field of drug delivery: systemic RNA delivery, drug delivery for localized therapy, oral drug delivery systems, and biologic drug delivery systems. In each case, we present the barriers to effective drug delivery as well as chemical and mater...
Future of Federal-Sector Labor-Management Relations

Since the inception of the federal-sector labor-management program in 1963 with the issuance of Executive Order 10988, the program has experienced sixteen years of trending toward collaboration and thirty-five years of adversarial labor-management relations. Adversarial labor-management relationships are antithetical to collaborative labor-management relationships. Notwithstanding the fact that collaborative labor-management relations can satisfy the interests of managers and employees through their unions to create better delivery of public service, the confluence of presidential, managerial, and union leader support is hard to create and maintain.
Addressing Complex and Subjective Product-Related Queries with Customer Reviews

Online reviews are often our first port of call when considering products and purchases online. When evaluating a potential purchase, we may have a specific query in mind, e.g. `will this baby seat fit in the overhead compartment of a 747?' or `will I like this album if I liked Taylor Swift's 1989?'. To answer such questions we must either wade through huge volumes of consumer reviews hoping to find one that is relevant, or otherwise pose our question directly to the community via a Q/A system. In this paper we hope to fuse these two paradigms: given a large volume of previously answered queries about products, we hope to automatically learn whether a review of a product is relevant to a given query. We formulate this as a machine learning problem using a mixture-of-experts-type framework---here each review is an `expert' that gets to vote on the response to a particular query; simultaneously we learn a relevance function such that `relevant' reviews are those that vote correctly. At test time this learned relevance function allows us to surface reviews that are relevant to new queries on-demand. We evaluate our system, Moqa, on a novel corpus of 1.4 million questions (and answers) and 13 million reviews. We show quantitatively that it is effective at addressing both binary and open-ended queries, and qualitatively that it surfaces reviews that human evaluators consider to be relevant.
Determining the Nature of Dependency between Agribusiness and Non-Agribusiness Stocks

During the financial downturn of 2008, asset classes that investors traditionally found to have low correlation with U.S. stocks became more highly correlated at the most inopportune time. Post-downturn, investors increasingly looked for alternative assets that offer diversification benefits, one of which being farmland. One of the challenges of investing in farmland is that the asset is not a securitized, low-cost investment. The current research investigates the whether exposure to farmland via an index of agribusiness stocks provides significant diversification benefits. We estimated the dependence between daily returns of the S&P 500 and an index of agribusiness stocks from 1970 through 2008 using copulas. We find significant evidence that agribusiness stocks have strong lower tail dependence with large U.S. stocks and are actually less correlated in the upper tail of the distribution. Meaning, the agribusiness index moves in near lockstep with U.S. stocks in downturns and more independently in large upswings. This provides little evidence to support the investment strategy of purchasing agribusiness stocks broadly to gain exposure to farmland.
Quantitative myocardial perfusion PET parametric imaging at the voxel-level

1518 Objectives To assess performance of a novel approach to obtain quantitative parametric images in cardiac PET. Methods We have proposed a parametric PET image formation method utilizing spatial constraints via what we term physiological clustering (PC): this iterative kinetic-driven-clustering method observes that ideal clustering depends on underlying physiology of functional regions, and in turn, physiological processes are quantified by kinetic parameter estimation. 30 noise-realizations of Rb-82 datasets were generated based on realistic kinetic parameters and input function. Transmural/non-transmural perfusion defects were simulated. We also validated our approach on n=5 Rb-82 patient studies. Voxel-wise kinetic parameters were obtained using (i) conventional post-smoothing (PS) on reconstructed images (Butterworth, order 4, cut-off 0.2-1 cycles/cm), and (ii) PC, where regression was performed on non-smoothed images via a quadratic penalty that penalizes deviations from mean kinetics as computed using PC of dynamic images. Results Enhanced noise-bias performance was obtained for both transmural (T) and non-transmural (NT) defects. Specifically, for T, at optimal performance (minimum RMSE), PS reduced noise by 27% with 3.9% increase in bias (38% RMSE reduction). PC reduced noise by 33% with 1.2% increase in bias (46% RMSE reduction). For NT, PS reduced noise by 28% with 4.7% increase in bias (37% RMSE reduction). PC reduced noise by 33.4% with 3.0% increase in bias (47% RMSE reduction). PC, compared to PS, resulted in higher CNR (13.7 as opposed to 7.2 for T; and 11.3 as opposed to 5.7 for NT) at optimal performance. In patient studies, PC resulted in significantly higher CNR at matched K1 value (x 2 improvement at converged values). Conclusions Parametric imaging based on PC clearly outperformed conventional estimation method in transmural and non-transmural perfusion defects. Research Support 2014 Bradley-Alavi Fellowship, SNMMI
Dynamics of inert spheres in active suspensions of micro-rotors

Inert particles suspended in active fluids of self-propelled particles are known to often exhibit enhanced diffusion and novel coherent structures. Here we numerically investigate the dynamical behavior and self-organization in a system consisting of passive and actively rotating spheres of the same size. The particles interact through direct collisions and the fluid flows generated as they move. In the absence of passive particles, three states emerge in a binary mixture of spinning spheres depending on particle fraction: a dilute gas-like state where the rotors move chaotically, a phase-separated state where like-rotors move in lanes or vortices, and a jammed state where crystals continuously assemble, melt and move (K. Yeo, E. Lushi, and P. M. Vlahovska, Phys. Rev. Lett., 2015, 114, 188301). Passive particles added to the rotor suspension modify the system dynamics and pattern formation: while states identified in the pure active suspension still emerge, they occur at different densities and mixture proportions. The dynamical behavior of the inert particles is also non-trivially dependent on the system composition.
Negative urgency and emotion regulation predict positive smoking expectancies in non-smoking youth.

Abstract Introduction The purpose of the study was to better understand early risk for positive smoking expectancies, which have been shown to be consistent predictors of smoking initiation among youth. Two affect-based risk factors—negative urgency and emotion dysregulation—associated with smoking behaviors among youth, were examined for unique and interactive effects on positive smoking expectancies among substance-naive youth. Methods Participants were 61 10–14-year-old children with virtually no drug use (less than 5 substance use incidents across the lifetime), who were drawn from the community. Results Both negative urgency and emotion dysregulation were significantly associated with positive social facilitation smoking expectancies. Further, negative urgency was significantly related to positive social facilitation smoking expectancies at higher levels of emotion dysregulation ( b = .09, p = .001). Conclusion The findings provide evidence that both emotion dysregulation and negative urgency are positively associated with positive social-related smoking expectancies among a sample of 10–14-year-olds. Children who are emotionally dysregulated and who act rashly in response to negative emotions appear more likely to endorse beliefs regarding the socially enhancing effects of smoking, suggesting that these youth may be at high risk for smoking initiation.
Evaluating computational models of explanation using human judgments

We evaluate four computational models of explanation in Bayesian networks by comparing model predictions to human judgments. In two experiments, we present human participants with causal structures for which the models make divergent predictions and either solicit the best explanation for an observed event (Experiment 1) or have participants rate provided explanations for an observed event (Experiment 2). Across two versions of two causal structures and across both experiments, we find that the Causal Explanation Tree and Most Relevant Explanation models provide better fits to human data than either Most Probable Explanation or Explanation Tree models. We identify strengths and shortcomings of these models and what they can reveal about human explanation. We conclude by suggesting the value of pursuing computational and psychological investigations of explanation in parallel.
Out of the Blue! Azuliporphyrins and Related Carbaporphyrinoid Systems.

ConspectusFirst reported in 1997, azuliporphyrins have proven to be a truly remarkable family of porphyrin analogues. In this system, although the porphyrin framework is retained, one of the pyrrolic moieties has been replaced by an azulene unit. Azulene favors electrophilic substitution at the 1,3-positions, which are structurally analogous to the α-positions in pyrrole, and this property facilitates the construction of azulene-containing porphyrinoid systems. Azuliporphyrins were first prepared from tripyrranes and 1,3-azulenedicarbaldehyde using a “3 + 1” variant on the MacDonald reaction. Subsequently, azulenes were shown to react with acetoxymethylpyrroles under acidic conditions to generate azulitripyrranes that could be utilized in a back-to-front “3 + 1” methodology to form azuliporphyrins and related heteroporphyrinoids. In addition, the favorability of azulenes toward 1,3-substitution was applied to one-pot syntheses of tetraarylazuliporphyrins and calix[4]azulenes.Azuliporphyrins have significa...
A direct approach to amines with remote stereocentres by enantioselective CuH-catalysed reductive relay hydroamination

Single operation transformations that enantioselectively install a stereogenic centre while introducing a distal functional group are synthetically valuable but rare processes. Now, a copper-catalysed reductive relay hydroamination process that simultaneously creates a remote chiral centre is described. The resulting γ- and δ-chiral amines are important structural elements in many pharmaceutical agents and natural products.
A two-level approach to large mixed-integer programs with application to cogeneration in energy-efficient buildings

We study a two-stage mixed-integer linear program (MILP) with more than 1 million binary variables in the second stage. We develop a two-level approach by constructing a semi-coarse model that coarsens with respect to variables and a coarse model that coarsens with respect to both variables and constraints. We coarsen binary variables by selecting a small number of prespecified on/off profiles. We aggregate constraints by partitioning them into groups and taking convex combination over each group. With an appropriate choice of coarsened profiles, the semi-coarse model is guaranteed to find a feasible solution of the original problem and hence provides an upper bound on the optimal solution. We show that solving a sequence of coarse models converges to the same upper bound with proven finite steps. This is achieved by adding violated constraints to coarse models until all constraints in the semi-coarse model are satisfied. We demonstrate the effectiveness of our approach in cogeneration for buildings. The coarsened models allow us to obtain good approximate solutions at a fraction of the time required by solving the original problem. Extensive numerical experiments show that the two-level approach scales to large problems that are beyond the capacity of state-of-the-art commercial MILP solvers.
Sexuality in Aging: Implications for Nursing Facility Staff

Sexuality is an area that is frequently overlooked by staff who work with the elderly in nursing facilities. The nursing literature supports a need for education of nursing facility staff about sexual issues and concerns of facility residents. This article describes the effect of an educational intervention on one sample of facility staff and recommends strategies for the education and practice of staff members employed in nursing facilities.
LOCAL u'g'r'i'z' STANDARD STARS IN THE CHANDRA DEEP FIELD SOUTH

Because several observing programs are under way in various spectral regimes to explore the Chandra Deep Field South (CDF-S), the value of local photometric standards is obvious. As part of an NOAO Survey Program to establish u'g'r'i'z' standard stars in the southern hemisphere, we have observed the central region of the CDF-S to create local standards for use by other investigators using these filters. As a courtesy, we present the CDF-S standards to the public now, although the main program will not finish until mid-2005.
Three-point functions in duality-invariant higher-derivative gravity

Here, doubled α'-geometry is the simplest higher-derivative gravitational theory with exact global duality symmetry. We use the double metric formulation of this theory to compute on-shell three-point functions to all orders in α'. A simple pattern emerges when comparing with the analogous bosonic and heterotic three-point functions. As in these theories, the amplitudes factorize. The theory has no Gauss-Bonnet term, but contains a Riemann-cubed interaction to second order in α'.
To reveal the quark structure of matter

Abstract I present a overview of some central issues facing strong interaction physics today, with an emphasis on questions that will be addressed in concert by CEBAF at Jefferson Lab and by the new DAPHNE machine at Frascati Lab.
Hopes, fears, and software obfuscation

I survey some of the recent progress on software obfuscation spurred by the exciting paper of Garg, Gentry, Halevi, Raykova, Sahai and Waters [GGH13]. This is a preprint version of a review article [Bar16] appearing in the Communications of the ACM. That article was written for a general computing audience, and is also not up to date on the latest research in this fast-moving field since it was mostly written in 2014. Nevertheless, I thought it might still be of interest to cryptographers. Computer programs are arguably the most complex objects ever constructed by humans. Even understanding a 10-line program such as the one depicted in Figure 1 can be extremely difficult. The complexity of programs has been the bane (as well as the boon) of the software industry, and taming it has been the objective of many efforts in industry and academia. Given this, it is not surprising that both theoreticians and practitioners have been trying to “harness this complexity for good” and use it to protect sensitive information and computation. In its most general form this is known as software obfuscation, and it is the topic of this survey. In a certain sense, any cryptographic tool such as encryption or authentication can be thought of harnessing complexity for security, but with software obfuscation people have been aiming for something far more ambitious: a way to transform arbitrary programs into an “inscrutable” or obfuscated form. By this we don’t mean that reverse engineering the program should be cumbersome but rather that it should be infeasible, in the same way that recovering the plaintext of a secure encryption cannot be performed using any reasonable amount of resources. ∗Harvard John A. Paulson School of Engineering and Applied Sciences, b@boazbarak.org. This article was written while the author was at Microsoft Research
Inequity-averse preferences in general equilibrium

Abstract We study the stability with respect to the introduction of opportunity-based inequity aversion a la Dufwenberg et al. (2011) of three welfare properties satisfied by competitive equilibria in self-regarding economies: (i) Pareto efficiency may not be a stable property; (ii) undomination with respect to income redistribution is a stable property whenever the marginal indirect utility of income has no extreme variations; and (iii) generically (endowment-wise) market-constrained efficiency is a stable property.
Vision-based Event Detection of the Sit-to-Stand Transition

Sit-to-stand (STS) motions are one of the most important activities of daily living as they serve as a precursor to mobility and walking. However, there exist no standard method of segmenting STS motions. This is partially due to the variety of different sensors and modalities used to study the STS motion such as force plate, vision, and accelerometers, each providing different types of data, and the variability of the STS motion in video data. In this work, we present a method using motion capture to detect events in the STS motion by estimating ground reaction forces, thereby eliminating the variability in joint angles from visual data. We illustrate the accuracy of this method with 10 subjects with an average difference of 16.5ms in event times obtained via motion capture vs force plate. This method serves as a proof of concept for detecting events in the STS motion via video which are comparable to those obtained via force plate.