cssi/SciSciGPT-SciSciNet huggingface dataset:
Evolution of the cluster abundance in non-Gaussian models

We carry out N-body simulations of several non-Gaussian structure formation models, including Peebles’ isocurvature cold dark matter model, cosmic string models, and a model with primordial voids. We compare the evolution of the cluster mass function in these simulations with that predicted by a modified version of the Press–Schechter formalism. We find that the Press–Schechter formula can accurately fit the cluster evolution over a wide range of redshifts for all of the models considered, with typical errors in the mass function of less than 25 per cent, considerably smaller than the amount by which predictions for different models may differ. This work demonstrates that the Press–Schechter formalism can be used to place strong model-independent constraints on non-Gaussianity in the Universe.
A new macrocycle demonstrates ditopic recognition properties

The synthesis and binding properties of a new macrocycle is reported. The host, comprised of three basic pyridines, four hydrogen bond accepting carbonyls, and two hydrogen bond donating amide groups, binds mono-alkyl ammonium salts in a manner that is dependent on the counter-ion of the ammonium guest.
Neural Random-Access Machines

Abstract: In this paper, we propose and investigate a new neural network architecture called Neural Random Access Machine. It can manipulate and dereference pointers to an external variable-size random-access memory. The model is trained from pure input-output examples using backpropagation. We evaluate the new model on a number of simple algorithmic tasks whose solutions require pointer manipulation and dereferencing. Our results show that the proposed model can learn to solve algorithmic tasks of such type and is capable of operating on simple data structures like linked-lists and binary trees. For easier tasks, the learned solutions generalize to sequences of arbitrary length. Moreover, memory access during inference can be done in a constant time under some assumptions.
Discrete Mathematical Physics and Particle Modeling

Publisher Summary This chapter explores the theory and the application of the arithmetic approach, which is motivated by and implemented through modern high speed digital computer technology. A conservative arithmetic formulation of the Hamiltonian approach is developed by a discrete calculus of variations by Newtonian mechanics. Other discrete models developed include classical cavity flow, conservative harmonic oscillations, discrete biological population dynamics, biological circularization and gastrulation, atmospheric streaming, ocean wave generation due to earthquakes, and conservative interactions in which the potentials are anisotropic. Radiative transfer on discrete spaces is also examined in the chapter. However, the discretization of certain integral relationships can lead to arithmetic formulations, which are conservative because they conserve discrete energy. However, this “discrete energy” is different from the energy of the continuous formulation. Modeled quantum mechanically, a three-bead-two-rod discrete classical approach, is developed for modeling macromolecules and is applied successfully to the study of polymers. Conservative computer logic and two types of sequential circuitry are already developed, while computer systems analysis theory is being developed for the discrete modeling of both natural and social systems.
EVALUATING INJURY PREVENTION PROGRAMS: THE OKLAHOMA CITY SMOKE ALARM PROJECT

Evaluation of injury prevention programs is critical for measuring program effects on reducing injury related morbidity and mortality or on increasing the adoption of safety practices. During the planning and implementation of injury prevention programs, evaluation data also can be used to test program strategies and to measure the program's penetration among the target population. The availability of this early data enables program managers to refine a program, increasing the likelihood of successful outcomes. The Oklahoma City Smoke Alarm Project illustrates how an evaluation was designed to inform program decisions by providing methodologically sound data on program processes and outcomes. This community intervention trial was instituted to reduce residential fire-related injuries and deaths in a geographic area of Oklahoma City that was disproportionately affected by this problem. The distribution of free smoke alarms in targeted neighborhoods was accompanied by written educational pamphlets and home-based follow-up to test whether the alarms were functioning correctly. Early evaluation during the planning and implementation phases of the program allowed for midcourse corrections that increased the program's impact on desired outcomes. During the six years following the project, the residential fire-related injury rate decreased 81% in the target population but only 7% in the rest of Oklahoma City. This dramatic decline in fire-related injuries in the target area is largely attributed to the free smoke alarm distribution as well as to educational efforts promoting awareness about residential fires and their prevention.
Computed tomography assessment of peripubertal craniofacial morphology in a sheep model of binge alcohol drinking in the first trimester

Identification of facial dysmorphology is essential for the diagnosis of fetal alcohol syndrome (FAS); however, most children with fetal alcohol spectrum disorders (FASD) do not meet the dysmorphology criterion. Additional objective indicators are needed to help identify the broader spectrum of children affected by prenatal alcohol exposure. Computed tomography (CT) was used in a sheep model of prenatal binge alcohol exposure to test the hypothesis that quantitative measures of craniofacial bone volumes and linear distances could identify alcohol-exposed lambs. Pregnant sheep were randomly assigned to four groups: heavy binge alcohol, 2.5 g/kg/day (HBA); binge alcohol, 1.75 g/kg/day (BA); saline control (SC); and normal control (NC). Intravenous alcohol (BA; HBA) or saline (SC) infusions were given three consecutive days per week from gestation day 4-41, and a CT scan was performed on postnatal day 182. The volumes of eight skull bones, cranial circumference, and 19 linear measures of the face and skull were compared among treatment groups. Lambs from both alcohol groups showed significant reduction in seven of the eight skull bones and total skull bone volume, as well as cranial circumference. Alcohol exposure also decreased four of the 19 craniofacial measures. Discriminant analysis showed that alcohol-exposed and control lambs could be classified with high accuracy based on total skull bone volume, frontal, parietal, or mandibular bone volumes, cranial circumference, or interorbital distance. Total skull volume was significantly more sensitive than cranial circumference in identifying the alcohol-exposed lambs when alcohol-exposed lambs were classified using the typical FAS diagnostic cutoff of ≤10th percentile. This first demonstration of the usefulness of CT-derived craniofacial measures in a sheep model of FASD following binge-like alcohol exposure during the first trimester suggests that volumetric measurement of cranial bones may be a novel biomarker for binge alcohol exposure during the first trimester to help identify non-dysmorphic children with FASD.
TWO-WAY INDUCTION

General-to-specific learners like ID3 and CN2 perform well when the target concept descriptions are general, but often have difficulties when they are specific or mixed. This problem can be alleviated by combining them with a specific-to-general learning component, resulting in a two-way induction system. In this paper one design for such a component is proposed, as well as two methods for combining the two components. Experiments on artificial domains show the combined learner to match or outperform “pure” versions of C4.5 and CN2 across the entire generality spectrum, with the advantage increasing for greater concept specificity. Experiments on 24 real-world domains from the UCI repository confirm the utility of two-way induction: the combined learner achieves higher accuracy than C4.5 in 17 domains (at the 5% significance level in 12), and similar results are obtained with CN2. Closer observation of the system’s behavior leads to a better understanding of its ability to correct overly-general rules with specific ones, and shows that there is still room for improvement.
Optimal wire retiming without binary search

The problem of retiming over a netlist of macroblocks to achieve minimal clock period, where block internal structures may not be changed and flip-flops may not be inserted on some wire segments, is called the optimal wire retiming problem. This paper presents a new algorithm that solves the optimal wire retiming problem with polynomial-time worst case complexity. Since the new algorithm avoids binary search and is essentially incremental, it has the potential of being combined with other optimization techniques. Experimental results show that the new algorithm is very efficient in practice
Stereocontrolled Synthesis of Diene and Enyne Sugar-Modified Nucleosides and Their Interaction with S-Adenosyl-L-homocysteine Hydrolase

Conjugated diene 5–7 and enyne 8 analogs derived from adenosine and uridine were synthesized employing Pd-catalyzed cross-coupling reactions.
Microcomputers in Special Education: Implications for Instructional Design.

The development of computer-assisted and computer-managed instruction involves a number of instructional design issues. The implications of these instructional design issues for special education p...
Graphs with the fewest matchings

In recent years there has been increased interest in extremal problems for "counting" parameters of graphs. For example, the Kahn-Zhao theorem gives an upper bound on the number of independent sets in a d-regular graph. In the same spirit, the Upper Matching Conjecture claims an upper bound on the number of k-matchings in a d-regular graph. Here we consider both matchings and matchings of fixed sizes in graphs with a given number of vertices and edges. We prove that the graph with the fewest matchings is either the lex or the colex graph. Similarly, for fixed k, the graph with the fewest k-matchings is either the lex or the colex graph. To prove these results we first prove that the lex bipartite graph has the fewest matchings of all sizes among bipartite graphs with fixed part sizes and a given number of edges.
Skinning maps are finite-to-one

We show that Thurston’s skinning maps of Teichmuller space have finite fibers. The proof centers around a study of two subvarieties of the \({{\rm SL}_2(\mathbb{C})}\) character variety of a surface—one associated with complex projective structures, and the other associated with a 3-manifold. Using the Morgan–Shalen compactification of the character variety and author’s results on holonomy limits of complex projective structures, we show that these subvarieties have only a discrete set of intersections.
Calibrating the Human Mutation Rate via Ancestral Recombination Density in Diploid Genomes.

The human mutation rate is an essential parameter for studying the evolution of our species, interpreting present-day genetic variation, and understanding the incidence of genetic disease. Nevertheless, our current estimates of the rate are uncertain. Most notably, recent approaches based on counting de novo mutations in family pedigrees have yielded significantly smaller values than classical methods based on sequence divergence. Here, we propose a new method that uses the fine-scale human recombination map to calibrate the rate of accumulation of mutations. By comparing local heterozygosity levels in diploid genomes to the genetic distance scale over which these levels change, we are able to estimate a long-term mutation rate averaged over hundreds or thousands of generations. We infer a rate of 1.61 ± 0.13 × 10−8 mutations per base per generation, which falls in between phylogenetic and pedigree-based estimates, and we suggest possible mechanisms to reconcile our estimate with previous studies. Our results support intermediate-age divergences among human populations and between humans and other great apes.
Quality of Life Assessment in Spina Bifida for Children (QUALAS-C): Development and Validation of a Novel Health-related Quality of Life Instrument.

Objective To develop and validate a self-reported health-related QUAlity of Life Assessment in Spina bifida for Children (QUALAS-C). Methods We drafted a 27-question pilot instrument using a patient-centered comprehensive item generation and refinement process. It was administered to a sample of children 8-12 years old with spina bifida (SB) recruited online via social media and in person at an outpatient SB clinic (January 2013-September 2014). Healthy controls were recruited at routine pediatrician visits. Validation and final questions were determined based on clinical relevance, high loadings on factor analysis, and domain psychometrics. Children with SB also completed the validated generic Kidscreen-27 instrument. Results Median age of 150 participants was 9.6 years (60.7% male, 72.7% Caucasian), similar to 46 controls (P ≥ .10). There were 97 online and 53 clinic participants (89.0% and 84.2% of eligible, respectively). Face and content validities of the 2-domain, 10-question QUALAS-C were established by patients, parents, and experts. Internal consistency and test-retest reliability was high for the Esteem & Independence and Bladder & Bowel domains (Cronbach's alpha: 0.72-0.76, ICC: 0.74-0.77). Correlations between QUALAS-C domains were low (r = 0.51), indicating that QUALAS-C can differentiate between two distinct health-related quality of life components. Correlations between QUALAS-C and Kidscreen-27 were also low (r ≤ 0.44). QUALAS-C scores were significantly lower in children with SB than without (P Conclusion QUALAS-C is a short, valid health-related quality of life tool for children with SB. It will be useful in clinical and research settings.
National tax policies towards product-innovating multinational enterprises

Abstract This paper examines source and host country taxation towards multinational enterprises that engage in product development. National tax policies are interdependent as they influence the range of products that the multinational enterprise develops worldwide. For the case where private and public goods are perfect substitutes, the source country optimally provides a tax credit and does not capture any tax revenue from the multinational's host country operations. However, the source country still gains from the multinational's foreign operations, as they induce additional product development.
List Prices, Sale Prices and Marketing Time: An Application to U.S. Housing Markets

∗∗∗ ∗∗∗ ∗∗∗∗ Many goods are marketed after first stating a list price, with the expectation that the eventual sales price will differ. In this article, we first present a simple model of search behavior that includes the seller setting a list price. Holding constant the mean of the buyers’ distribution of potential offers for a good, we assume that the greater the list price, the slower the arrival rate of offers but the greater is the maximal offer. This trade-off determines the optimal list price, which is set simultaneously with the seller’s reservation price. Comparative statics are derived through a set of numerical sensitivity tests, where we show that the greater the variance of the distribution of buyers’ potential offers, the greater is the ratio of the list price to expected sales price. Thus, sellers of atypical goods will tend to set a relatively high list price compared with standard goods. We test this hypothesis using data from the Columbus, Ohio, housing market and find substantial support. We also find empirical support for another hypothesis of the model: atypical dwellings take longer to sell. Although the theory of how the seller of an asset searches for a buyer is well developed,ithasfocusedlessfrequentlyonhowlist(ask)pricesaredetermined. However, setting a list price that differs from the expected selling price is a common occurrence in the U.S. economy. One of the largest such examples is the housing market. In 2007, 6.43 million existing and new homes were sold, each having a seller-determined list price. 1 In the vast majority of cases, the list price exceeded the sales price. Setting a list price that differs from the expected sales price also is common for automobiles and the fine art market and it occurs in some Internet auctions.
TREATREW : a user-written Stata routine for estimating Average Treatment Effects by reweighting on propensity score

Reweighting is a popular statistical technique to deal with inference in presence of a non- random sample. In the literature, various reweighting estimators have been proposed. This paper presents the user-written STATA command treatrew implementing the reweighting on propensity score estimator as proposed by Rosenbaum and Rubin (1983) in their seminal article, where parameters' standard errors can be obtained either analytically or via bootstrapping. Since an implementation in STATA of this estimator with analytic standard errors was still missing, this paper (and the ADO-file and HELP-file accompanying it) aims at filling this gap by providing the community with an easy-to-use implementation of the reweighting on propensity score method, as a valuable tool for estimating treatment effects under selection on observables.
A Theory of Balance Sheet Recessions with Informational and Trading Frictions

I propose a novel theory to rationalize limited sharing of macroeconomic risk that drives balance sheet recessions as a result of informational and trading frictions in financial markets. I show that borrowers and creditors will find it costly to share macroeconomic risk in environments where creditors value the liquidity of financial claims but where information about the future states of the economy is dispersed and the secondary markets for financial claims feature search frictions. As a result, borrowers will optimally choose to retain disproportionate exposures to macroeconomic risk on their balance sheets, and adverse shocks will be amplified through the balance sheet channel. I show that the magnitude of this amplification becomes closely linked to the level of information dispersion and the severity of search frictions. In this setting, I study the implications of the theory for macro-prudential regulation and find that subsidizing contingent write-downs of borrowersâ€™ liabilities can be welfare improving.
A p-adic interpretation of some integral identities for Hall-Littlewood polynomials

If one restricts an irreducible representation V λ of GL 2 n to the orthogonal group (respectively the symplectic group), the trivial representation appears with multiplicity one if and only if all parts of λ are even (resp. the conjugate partition λ ' is even). One can rephrase this statement as an integral identity involving Schur functions, the corresponding characters. Rains and Vazirani considered q , t -generalizations of such integral identities, and proved them using affine Hecke algebra techniques. In a recent paper, we investigated the q = 0 limit (Hall-Littlewood), and provided direct combinatorial arguments for these identities; this approach led to various generalizations and a finite-dimensional analog of a recent summation identity of Warnaar. In this paper, we reformulate some of these results using p-adic representation theory; this parallels the representation-theoretic interpretation in the Schur case. The nonzero values of the identities are interpreted as certain p-adic measure counts. This approach provides a p-adic interpretation of these identities (and a new identity), as well as independent proofs. As an application, we obtain a new Littlewood summation identity that generalizes a classical result due to Littlewood and Macdonald. Finally, our p-adic method also leads to a generalized integral identity in terms of Littlewood-Richardson coefficients and Hall polynomials.
The Impact of Tenant Diversification on Spreads and Default Rates for Mortgages on Retail Properties

We use an empirical model of commercial mortgage spreads to examine how tenant diversification impacts credit spreads for mortgages on retail properties. We find that mortgages on properties with a highly diversified tenant base have spreads that are up to 7.1 basis points higher than spreads on mortgages for single-tenant properties, but that mortgages on properties with moderate levels of tenant diversification have spreads that are up to 5.2 basis points lower than mortgages on single-tenant properties. The spread discount for mortgages on properties with moderate levels of tenant diversification disappears when the lease of the property’s largest tenant expires before the loan matures. Despite the spread discount that is given to properties with moderate levels of tenant diversification, we find that the likelihood with which a mortgage goes into default increases as tenant diversification increases.
Community Capitalism in China

Hou proposes to end the dichotomous view of the state and the market, and capitalism and communism, by examining the local institutional innovation in three villages in China and presents community capitalism as an alternative to the neoliberal model of development. Community is both the unit of redistribution and the entity that mobilizes resources to compete in the market; collectivism creates the boundary that sets the community apart from the outside and justifies and sustains the model. Community capitalism differs from Mao-era collectivism, when individual interests were buried in the name of collective interests and market competition was not a concern. This book demonstrates the embeddedness of the market in community, showing how social relations, group solidarity, power, honor, and other values play an important role in these villages' social and economic organization.
Superconvergent Two-Grid Methods for Elliptic Eigenvalue Problems

Some numerical algorithms for elliptic eigenvalue problems are proposed, analyzed, and numerically tested. The methods combine advantages of the two-grid algorithm (Xu and Zhou in Math Comput 70(233):17---25, 2001), the two-space method (Racheva and Andreev in Comput Methods Appl Math 2:171---185, 2002), the shifted inverse power method (Hu and Cheng in Math Comput 80:1287---1301, 2011; Yang and Bi in SIAM J Numer Anal 49:1602---1624, 2011), and the polynomial preserving recovery enhancing technique (Naga et al. in SIAM J Sci Comput 28:1289---1300, 2006). Our new algorithms compare favorably with some existing methods and enjoy superconvergence property.
Pharmacogenomically actionable medications in a safety net health care system.

Objective:Prior to implementing a trial to evaluate the economic costs and clinical outcomes of pharmacogenetic testing in a large safety net health care system, we determined the number of patients taking targeted medications and their clinical care encounter sites.Methods:Using 1-year electronic medical record data, we evaluated the number of patients who had started one or more of 30 known pharmacogenomically actionable medications and the number of care encounter sites the patients had visited.Results:Results showed 7039 unique patients who started one or more of the target medications within a 12-month period with visits to 73 care sites within the system.Conclusion:Findings suggest that the type of large-scale, multi-drug, multi-gene approach to pharmacogenetic testing we are planning is widely relevant, and successful implementation will require wide-scale education of prescribers and other personnel involved in medication dispensing and handling.
The Unreasonable Effectiveness of Noisy Data for Fine-Grained Recognition

Current approaches for fine-grained recognition do the following: First, recruit experts to annotate a dataset of images, optionally also collecting more structured data in the form of part annotations and bounding boxes. Second, train a model utilizing this data. Toward the goal of solving fine-grained recognition, we introduce an alternative approach, leveraging free, noisy data from the web and simple, generic methods of recognition. This approach has benefits in both performance and scalability. We demonstrate its efficacy on four fine-grained datasets, greatly exceeding existing state of the art without the manual collection of even a single label, and furthermore show first results at scaling to more than 10,000 fine-grained categories. Quantitatively, we achieve top-1 accuracies of \(92.3\,\%\) on CUB-200-2011, \(85.4\,\%\) on Birdsnap, \(93.4\,\%\) on FGVC-Aircraft, and \(80.8\,\%\) on Stanford Dogs without using their annotated training sets. We compare our approach to an active learning approach for expanding fine-grained datasets.
Relative susceptibility of red and green color forms of green peach aphid to insecticides

Field populations of green peach aphid, Myzus persicae (Sulzer), were collected from five produce fields near Yuma, Arizona. Three of the fields sampled contained both red and greencolored forms, while the remaining two fields contained only greencolored green peach aphids. Red -colored aphids were consistently more resistant to dimethoate and lambda -cyhalothrin, and usually more resistant to endosulfan than greencolored aphids collected from the same field. Slight differences in susceptibility to imidacloprid suggest that development of resistance is a possibility and justifies close resistance monitoring. Susceptibility to imidacloprid was not influenced by color form. We detected little or no differences in susceptibility to acephate, mevinphos or bifenthrin.
A Trotter-Suzuki approximation for Lie groups with applications to Hamiltonian simulation

We present a product formula to approximate the exponential of a skew-Hermitian operator that is a sum of generators of a Lie algebra. The number of terms in the product depends on the structure factors. When the generators have large norm with respect to the dimension of the Lie algebra, or when the norm of the effective operator resulting from nested commutators is less than the product of the norms, the number of terms in the product is significantly less than that obtained from well-known results. We apply our results to construct product formulas useful for the quantum simulation of some continuous-variable and bosonic physical systems, including systems whose potential is not quadratic. For many of these systems, we show that the number of terms in the product can be sublinear or even subpolynomial in the dimension of the relevant local Hilbert spaces, where such a dimension is usually determined by the energy scale of the problem. Our results emphasize the power of quantum computers for the simulation of various quantum systems.
Sixty years of stochastic linearization technique

Stochastic linearization technique is a versatile method of solving nonlinear stochastic boundary value problems. It allows obtaining estimates of the response of the system when exact solution is unavailable; in contrast to the perturbation technique, its realization does not demand smallness of the parameter; on the other hand, unlike the Monte Carlo simulation it does not involve extensive computational cost. Although its accuracy may be not very high, this is remedied by the fact that the stochastic excitation itself need not be known quite precisely. Although it was advanced about six decades ago, during which several hundreds of papers were written, its foundations, as exposed in many monographs, appear to be still attracting investigators in stochastic dynamics. This study considers the methodological and pedagogical aspects of its exposition.
Mirrlees meets Diamond-Mirrlees

We show that the Diamond and Mirrlees (1971) linear tax model contains the Mirrlees (1971) nonlinear tax model as a special case. In this sense, the Mirrlees model is an application of Diamond-Mirrlees. We also provide a simple derivation of the Mirrleesian optimal income tax formula from the Diamond-Mirrlees commodity tax formula. In the Mirrlees model, the relevant compensated cross-price elasticities are zero, providing a situation where an inverse elasticity rule holds. We provide four extensions that illustrate the power and ease of our approach, based on Diamond-Mirrlees, to study nonlinear taxation. First, we consider annual taxation in a lifecycle context. Second, we include human capital investments. Third, we incorporate more general forms of heterogeneity into the basic Mirrlees model. Fourth, we consider an extensive margin labor force participation decision, alongside the intensive margin choice. In all these cases, the relevant optimality condition is easily obtained as a direct application of the general Diamond-Mirrlees linear tax formula.
Monetary Policy and Stock Prices: Does the “Fed Put” Work When It Is Most Needed?

Most studies of the effect of monetary policy on asset prices use the event study methodology with daily data. The resulting estimates suffer from bias due to omitted variables and endogeneity of policy decisions. We provide evidence that this bias becomes so large during the 2007–2008 financial crisis that it reverses the sign of the estimated stock market response to monetary news, leading to an erroneous conclusion that interest rate cuts are bad news for stocks. We also examine the stock market reaction to monetary policy during the zero lower bound period. The results show a significant bias in daily event study estimates of the stock market response to news about the future path of monetary policy. © 2016 Wiley Periodicals, Inc. Jrl Fut Mark 36:1210–1230, 2016
Learning executable semantic parsers for natural language understanding

For building question answering systems and natural language interfaces, semantic parsing has emerged as an important and powerful paradigm. Semantic parsers map natural language into logical forms, the classic representation for many important linguistic phenomena. The modern twist is that we are interested in learning semantic parsers from data, which introduces a new layer of statistical and computational issues. This article lays out the components of a statistical semantic parser, highlighting the key challenges. We will see that semantic parsing is a rich fusion of the logical and the statistical world, and that this fusion will play an integral role in the future of natural language understanding systems.
Tukey’s transformational ladder for portfolio management

Over the past half-century, the empirical finance community has produced vast literature on the advantages of the equally weighted Standard and Poor (SP DeMiguel et al. in Rev Financ Stud 22(5):1915–1953, 2009; Jacobs et al. in J Financ Mark 19:62–85, 2014; Treynor in Financ Anal J 61(5):65–69, 2005). However, portfolio allocation based on Tukey’s transformational ladder has, rather surprisingly, remained absent from the literature. In this work, we consider the S&P 500 portfolio over the 1958–2015 time horizon weighted by Tukey’s transformational ladder (Tukey in Exploratory data analysis, Addison-Wesley, Boston, 1977): $$1/x^2,\,\, 1/x,\,\, 1/\sqrt{x},\,\, \text {log}(x),\,\, \sqrt{x},\,\, x,\,\, \text {and} \,\, x^2$$ , where x is defined as the market capitalization weighted S&P 500 portfolio. Accounting for dividends and transaction fees, we find that the 1/ $$x^2$$ weighting strategy produces cumulative returns that significantly dominate all other portfolio returns, achieving a compound annual growth rate of 18% over the 1958–2015 horizon. Our story is furthered by a startling phenomenon: both the cumulative and annual returns of the $$1/x^2$$ weighting strategy are superior to those of the 1 / x weighting strategy, which are in turn superior to those of the $$1/\sqrt{x}$$ weighted portfolio, and so forth, ending with the $$x^2$$ transformation, whose cumulative returns are the lowest of the seven transformations of Tukey’s transformational ladder. The order of cumulative returns precisely follows that of Tukey’s transformational ladder. To the best of our knowledge, we are the first to discover this phenomenon.
Shallow versus Deep Nature of Mg Acceptors in Nitride Semiconductors

We investigate the properties of Mg acceptors in nitride semiconductors with hybrid functional calculations. We find that although the thermodynamic transition level is relatively close to the valence band in GaN (260 meV), Mg(Ga) exhibits key features of a deep acceptor: the hole is localized on a N atom neighboring the Mg impurity, inducing a large local lattice distortion and giving rise to broad blue luminescence. We show that the ultraviolet photoluminescence peak attributed to Mg acceptors in GaN is likely related to Mg-H complexes, explaining the results of photoluminescence and electron paramagnetic resonance experiments. Predictions for Mg acceptors in AlN and InN are also presented.
Adhesion and Wetting of Soft Nanoparticles on Textured Surfaces: Transition between Wenzel and Cassie–Baxter States

We use a combination of the molecular dynamics simulations and scaling analysis to study interactions between gel-like nanoparticles and substrates covered with rectangular shape posts. Our simulations have shown that nanoparticles in contact with substrate undergo a first-order transition between the Cassie–Baxter and Wenzel states, which depends on nanoparticle shear modulus, the strength of nanoparticle–substrate interactions, height of the substrate posts, and nanoparticle size, Rp. There is a range of system parameters where these two states coexist such that the average indentation δ produced by substrate posts changes with nanoparticle shear modulus, Gp. We have developed a scaling model that describes deformation of nanoparticle in contact with patterned substrate. In the framework of this model, the effect of the patterned substrate can be taken into account by introducing an effective work of adhesion, Weff, which describes the first-order transition between Wenzel and Cassie–Baxter states. Ther...
X-Ray Diffraction Study of Some Synthetic Rubbers at Low Temperatures

Abstract A certain amount of ordering has been found in “noncrystalline” synthetic rubbers, which were studied by the use of the technique of cooling the raw polymer before it is elongated and freezing it immediately after stretching to prevent relaxation. Polybutadiene and polydimethylbutadiene, whose monomer units were structurally symmetrical, displayed the greatest degree of ordering. The presence of a high percentage of 1,2-units in sodium-polymerized butadiene destroyed almost all of the ordering observed in the emulsion polymer. GR-S and emulsion polybutadiene showed the presence of small amounts of crystallites, presumably of 1,4-addition polybutadiene, probably the trans-form. Polydimethylbutadiene showed the presence of crystallites presumably of 1,4-addition in the cis-form. The intermolecular distance between the extended chains increased with increasing amounts of side groups. The departure of the Bragg angle spacing of the amorphous halo from the corresponding quantity for the liquid monomer...
A More Efficient Approach for Monte Carlo Simulation of Deeply-Channeled Implanted Profiles in Single-Crystal Silicon

In this paper is reported a new approach for the Monte Carlo simulation of deeply-channeled implanted profiles in single-crystal silicon which has greatly improved efficiency. This approach has been successfully implemented in the UT Monte Carlo code (UT-MARLOWE). A time savings of up to 212X has been observed with a 4-stage simulation. A simulation of arsenic implants with 15 keV implant energy typically takes about 12 minutes on a workstation.
Arsenic-containing chalcophosphate molecular anions.

We report five new discrete molecular arsenic-based chalcophosphates, K7As3(P2Se6)4 (1), K6As2(P2Se6)3 (2), Cs6As2(P2Se6)3 (3), and Cs5As(P2Q6)2 [Q = Se (4a) and S (4b)]. Each of the compounds contains unique complex anions comprised of common building blocks that have condensed to produce these anions. Phosphorus forms well-known [P2Q6]4− moieties in all of the compounds that are bridged by arsenic trigonal pyramids in 1 and 2 and distorted octahedra in 3, 4a, and 4b. Although 2 and 3 have the same molecular formula, the structural difference between the two salts is attributed to the size of the alkali metal. The influence of flux basicity also seems to play a role in the formation of the molecular anion in 4a and 4b, which has been observed with other trivalent main-group elements at the octahedral position but only with the highly basic cesium alkali metal as the counterion. All structures were determined by single-crystal X-ray diffraction and are discussed along with phase-purity powder X-ray diffra...
Persistence and Potential Effects of Complex Organic Contaminant Mixtures in Wastewater-Impacted Streams

Natural and synthetic organic contaminants in municipal wastewater treatment plant (WWTP) effluents can cause ecosystem impacts, raising concerns about their persistence in receiving streams. In this study, Lagrangian sampling, in which the same approximate parcel of water is tracked as it moves downstream, was conducted at Boulder Creek, Colorado and Fourmile Creek, Iowa to determine in-stream transport and attenuation of organic contaminants discharged from two secondary WWTPs. Similar stream reaches were evaluated, and samples were collected at multiple sites during summer and spring hydrologic conditions. Travel times to the most downstream (7.4 km) site in Boulder Creek were 6.2 h during the summer and 9.3 h during the spring, and to the Fourmile Creek 8.4 km downstream site times were 18 and 8.8 h, respectively. Discharge was measured at each site, and integrated composite samples were collected and analyzed for >200 organic contaminants including metal complexing agents, nonionic surfactant degrada...
Enantioselective Catalytic Transannular Ketone–Ene Reactions

Highly enantio- and diastereoselective transannular ketone–ene reactions are catalyzed by a new chromium(III) triflate tridentate Schiff base complex. Electronically unactivated keto-olefins undergo heteroene reactions at ambient temperature to afford enantioenriched bicyclic alcohols, common structural motifs in natural products. The kinetic resolution of a configurationally stable planar-chiral cyclodecenone is also described.
Palladium(II)-Catalyzed Enantioselective C(sp3)–H Activation Using a Chiral Hydroxamic Acid Ligand

An enantioselective method for Pd(II)-catalyzed cross-coupling of methylene β-C(sp3)–H bonds in cyclobutanecarboxylic acid derivatives with arylboron reagents is described. High yields and enantioselectivities were achieved through the development of chiral mono-N-protected α-amino-O-methylhydroxamic acid (MPAHA) ligands, which form a chiral complex with the Pd(II) center. This reaction provides an alternative approach to the enantioselective synthesis of cyclobutanecarboxylates containing α-chiral quaternary stereocenters. This new class of chiral catalysts also show promises for enantioselective β-C(sp3)–H activation of acyclic amides.
Real people in surreal environments

The emergence of virtual reality (VR) is dramatically changing the way we communicate. It is redefining the role of computers and telephony to provide compelling virtual environments (VEs) that help mediate collaboration, conversation and social interaction between people.
Propagation of Ultrasonic Bulk Waves in High Polymers

The propagation of supersonic waves in bulk rubbers has been studied from 40 kc/sec. to 10 Mc/sec. and from −60°C to 60°C. The wave velocity was found to increase with decreasing temperature, leveling off both at high and low temperatures, and was found to increase slightly with frequency. Peaks in attenuation as a function of either temperature or frequency were observed, the peaks occurring at lower temperatures for lower frequencies. The peaks for butyl, a high loss rubber, are broader and higher than those for GR‐S and Hevea, which are lower loss rubbers. The results are in qualitative agreement with data obtained by strip methods at audiofrequencies. However, for bulk waves the real and imaginary parts of two elastic constants, the bulk and shear moduli, determine wave velocity and attenuation; hence, independent measurements of shear wave properties are necessary to evaluate these constants. A three constant theory is discussed, assuming a shear viscosity only, so that an effective modulus K+4μ/3 is...
Examination of tourism undergraduates’ industry commitment, in the context of China

ABSTRACTGrounded in the Social Cognitive Career Theory (SCCT), this study developed a comprehensive research framework that encapsulated both personal and contextual factors in terms of tourism undergraduates’ commitment to career choice in the context of China’s social and vocational contexts. Applying structural equation modeling (SEM) to the data collected from 446 undergraduate students studying tourism in China, this study shows that “self-interest,” “others’ support,” “social status,” “outcome expectation” and “nature of work” exert significant effects on students’ commitment to career choice. Implications of the findings include suggested interventions in attracting tourism students to persist in their career path.
Wide bandwidth and high resolution planar filter array based on DBR-metasurface-DBR structures.

We propose and experimentally demonstrate a planar array of optical bandpass filters composed of low loss dielectric metasurface layers sandwiched between two distributed Bragg reflectors (DBRs). The two DBRs form a Fabry-Perot resonator whose center wavelength is controlled by the design of the transmissive metasurface layer which functions as a phase shifting element. We demonstrate an array of bandpass filters with spatially varying center wavelengths covering a wide range of operation wavelengths of 250nm around λ = 1550nm (Δλ/λ = 16%). The center wavelengths of each filter are independently controlled only by changing the in-plane geometry of the sandwiched metasurfaces, and the experimentally measured quality factors are larger than 700. The demonstrated filter array can be directly integrated on top of photodetector arrays to realize on-chip high-resolution spectrometers with free-space coupling.
Structure from Motion on a Sphere

We describe a special case of structure from motion where the camera rotates on a sphere. The camera’s optical axis lies perpendicular to the sphere’s surface. In this case, the camera’s pose is minimally represented by three rotation parameters. From analysis of the epipolar geometry we derive a novel and efficient solution for the essential matrix relating two images, requiring only three point correspondences in the minimal case. We apply this solver in a structure-from-motion pipeline that aggregates pairwise relations by rotation averaging followed by bundle adjustment with an inverse depth parameterization. Our methods enable scene modeling with an outward-facing camera and object scanning with an inward-facing camera.
Influences of Neighborhood Characteristics and Personal Attitudes on University Commuters’ Public Transit Use

This study examined the links between attitudes, the built environment, and travel behavior on the basis of data from the Ohio State University’s 2012 Campus Transportation Survey. The analysis results indicated that attitudes might have explained travel behavior better than the built environment. Survey respondents were asked questions about their attitudes on public transit use, and their answers were grouped into new attitudinal factors by using principal component analysis. Then, new neighborhood categories were created by K-means cluster analysis by means of built-environment and land use variables (population density, employment density, housing density, median age of structures, percentage of single-family housing, and intersection density). As a result of this analysis, discrete neighborhood categories, such as urban high-density and residential neighborhoods, and urban low-density and mixed-use neighborhoods, were created. Then, differences in attitudes toward public transit were analyzed across ...
Decentralized Stochastic Optimal Power Flow in Radial Networks With Distributed Generation

This paper develops a power management scheme that jointly optimizes the real power consumption of programmable loads and reactive power outputs of photovoltaic (PV) inverters in distribution networks. The premise is to determine the optimal demand response schedule that accounts for the stochastic availability of solar power, as well as to control the reactive power generation or consumption of PV inverters adaptively to the real power injections of all PV units. These uncertain real power injections by PV units are modeled as random variables taking values from a finite number of possible scenarios. Through the use of second order cone relaxation of the power flow equations, a convex stochastic program is formulated. The objectives are to minimize the negative user utility, cost of power provision, and thermal losses, while constraining voltages to remain within specified levels. To find the global optimum point, a decentralized algorithm is developed via the alternating direction method of multipliers that results in closed-form updates per node and per scenario, rendering it suitable to implement in distribution networks with a large number of scenarios. Numerical tests and comparisons with an alternative deterministic approach are provided for typical residential distribution networks that confirm the efficiency of the algorithm.
Measurement-Based Real-Time Voltage Stability Monitoring for Load Areas

This paper proposes a measurement-based voltage stability monitoring method for a load area fed by N tie lines. Compared to a traditional Thevenin equivalent based method, the new method adopts an N $+1$ buses equivalent system so as to model and monitor individual tie lines. For each tie line, the method solves the power transfer limit against voltage instability analytically as a function of all parameters of that equivalent, which are online identified from real-time synchronized measurements on boundary buses of the load area. Thus, this new method can directly calculate the real-time power transfer limit on each tie line. The method is first compared with a Thevenin equivalent based method using a 4-bus test system and then demonstrated by case studies on the Northeast Power Coordinating Council (NPCC) 48-machine, 140-bus power system.
Investment scaling up and the role of government

ABSTRACTThis article studies the fiscal and welfare implications of a scaling up of public investment when the government is subject to inefficiencies on the spending and on the tax collection side. In our simulations, the scaling up of public investments results in higher long-run output and consumption levels but requires a fiscal stabilization package in order to preserve fiscal sustainability. The effects on consumers’ welfare after the fiscal adjustment are nontrivial. Our welfare analysis shows that consumers’ welfare is increased when the government smooths the fiscal adjustment via higher borrowing and not through an increase in taxation. Moreover, the comparison between several stabilization packages via tax adjustment shows that higher welfare is achieved when the government relies mostly on taxation of capital as this allows higher levels of consumption. Lower fiscal costs that do not undermine fiscal sustainability can however be achieved if the government manages to reduce inefficiency in tax...
Diseases of medical progress

Because of its well-founded and penetrating significance, the publication of “Diseases of Medical Progress” in the New England Journal of Medicine in 1956 attracted a great deal of attention in well-informed medical circles. A monograph which surveyed the growing and increasingly serious subject was published by the author in 1959 (Charles C Thomas, Publisher). The present review brings the subject up to date. How long it will remain so is an open question. In any event, it was considered that the subject is of sufficient importance to devote half of an entire issue of this journal to it.