cssi/SciSciGPT-SciSciNet huggingface dataset:
Putty–clay technology and stock market volatility

Abstract Firms' first-order conditions imply that stock returns equal investment returns from the production technology. Much applied work uses the adjustment cost technology, which implies that the realized return is high when the investment-capital ratio is high. This paper derives, for an arbitrary stochastic discount factor, the investment return implied by the putty–clay technology. The combination of capital heterogeneity and irreversibility creates a novel channel for return volatility. The investment return is high when the ratio of investment to gross job creation is low. Empirically, the putty–clay feature helps account for U.S. stock market data.
Simulating human decision making for testing soft and hard/soft fusion algorithms

Current methods for evaluating the effects of human opinions in data fusion systems are often dependent on human testing (which is logistically hard and difficult to arrange for repeated tests of the same population). The alternative is to use hypothetical examples, which tend to be simplistic. To facilitate studies of data fusion architectures which integrate “soft” human-generated decisions, we have used a simulator of subjective beliefs. The simulator is based on the two-stage dynamic signal detection model of Pleskac and Busemeyer (2010). We use this scheme to simulate human opinions and combine them using belief fusion methods, including Bayes' Rule; Dempster's Rule of Combination (DRC); Yager's rule; the Proportional Conflict Redistribution Rule #5 (PCR5) from Dezert-Smarandache theory; and the consensus operator from subjective logic. In our simulations, the DRC and Bayes rule exhibited performance that was on par with, and in some cases better than PCR5 and the consensus operator (when used in conjunction with a measure of source reliability). In all simulated cases, Yager's rule exhibited inferior performance.
Rearranging data to maximize the efficiency of compression

Abstract We are concerned with rearranging the order in which data is stored in a database so as to maximize the amount of compression. We consider multi-attribute data defined over finite discrete domains (called categories ) and seek an optimal permutation of the categories for each attribute. We study both deterministic and probabilistic models of data distribution. We show that the deterministic category rearrangement problem is NP-complete (for run length encoding compression methods) via a reduction to the rectilinear traveling salesman problem. For the probabilistic model, we show that the optimal category rearrangement for each attribute has the form of a double pipe organ , which is a generalized version of the well-known pipe organ arrangement found in earlier work on record placement on disk cylinders. For k -dimensional data we obtain an algorithm for finding the optimal arrangement which is O ( n 2 ) for fixed k .
Reaction of Ketophosphonium Ylides with Dimethyl Acetylenedicarboxylate

Abstract The reaction of ketophosphonium ylides with dimethyl acetylenedicarboxylate in aprotic solvents gave mixtures of Z and E alkene products. Under protic conditions the initial Michael adduct was protonated and gave Z and E isomers of the alkene product as well. Depending on the alkyl group of the ketoylide, different product ratios were seen.
Effect of Disorder in the Periodic Anderson Model

We have studied the one-dimensional periodic, symmetric Anderson model at half filling in the presence of disorder using finite-temperature quantum Monte Carlo techniques. We have examined for the first time the disorder both in hybridization between the local f-orbitals and the conduction electrons and in the local f=site energy, using a uniform distribution. We find that the disorder in hybridization has a dramatic effect on the low-temperature magnetic properties giving rise to a non-Fermi-liquid behavior, and that the magnetic susceptibility can be scaled by a power law with an exponent that is comparable with recent experiments. On the other hand, disorder in the local f-orbital energy level does not show a non-Fermi liquid behavior.
New optical and electric-field-assisted fluidic pick-and-place technique

Electrophoresis is a classical electrochemical transport process, which is based on the migration of charged particles in a suspension by the influence of an electric field. One of the important applications of this technique is the study of DNA/RNA hybridization on bio-electronic chips. However, electrophoretic pick and place techniques are currently limited to the serial `pick' and `place' of individual devices or materials. There is a need for the rapid and parallel pick-and-place of individual devices to particular locations on a host substrate. In this paper, we present a novel electrochemical system for non-lithographic, field assisted, fluidic pick and place assembly of devices on a silicon substrate by means of electrical and optical addressing. The methodology presented here can be applied to massively parallel assembly of large semiconductor arrays (> 1000 X 1000) with fast (approximately a few seconds) and accurate positioning for a wide range of device sizes (0.8 - 100 micrometers ).
Computational geometry column 41

The recent results that n congruent balls in ℝd have at most 4 distinct geometric permutations is described.
Perspective on density functional theory

Density functional theory (DFT) is an incredible success story. The low computational cost, combined with useful (but not yet chemical) accuracy, has made DFT a standard technique in most branches of chemistry and materials science. Electronic structure problems in a dazzling variety of fields are currently being tackled. However, DFT has many limitations in its present form: too many approximations, failures for strongly correlated systems, too slow for liquids, etc. This perspective reviews some recent progress and ongoing challenges.
Invertibility of random matrices: Unitary and orthogonal perturbations

Author(s): Rudelson, Mark; Vershynin, Roman | Abstract: We show that a perturbation of any fixed square matrix D by a random unitary matrix is well invertible with high probability. A similar result holds for perturbations by random orthogonal matrices; the only notable exception is when D is close to orthogonal. As an application, these results completely eliminate a hard-to-check condition from the Single Ring Theorem by Guionnet, Krishnapur and Zeitouni.
Rhenium carbonyl clusters: synthesis, structure, reactivity

Cet article resume differents travaux concernant la preparation, la reactivite chimique, la caracterisation spectrometrique RMN et la caracterisation structurale des complexes carboxyles polynucleaires et heteronucleaires du rhenium. Les principaux coordinats organiques sont des phosphines tertiaires
Astrophysics of Dust in Cold Clouds

Nine lectures reviewing the astrophysics of dust in interstellar clouds. Topics include: (1) Summary of observational evidence concerning interstellar dust: broadband extinction, scattering of starlight, polarization of starlight, spectroscopy of dust, IR and FIR emission, and depletions of grain-forming elements. (2) Optics of interstellar dust grains: dielectric functions of nonconducting and conducting materials, calculational techniques, formulae valid in the Rayleigh limit, Kramers-Kronig relations, microwave emission mechanisms, and X-ray scattering. (3) IR and FIR emission: heating of interstellar dust, including single-photon heating, and resulting IR emission spectrum. (4) Charging of dust grains: collisional charging, photoelectric emission, and resulting charge distribution functions. (5) Dynamics: gas drag, Lorentz force, forces due to anisotropic radiation, and resulting drift velocities. (6) Rotational dynamics: brownian rotation, suprathermal rotation, and effects of starlight torques. (7) Alignment of interstellar dust: observations and theories. (8) Evolution of the grain population: dust formation in outflows, grain growth in the ISM, photodesorption, and grain destruction in shock waves. (9) Effects of dust grains: photoelectric heating, H2 formation, ion recombination, coupling of gas to magnetic fields, and dust grains as indicators of magnetic field direction.
Interply layer degradation effects on composite structural response

Recent research activities at NASA Lewis Research Center to computationally evaluate the effects of interply layer progressive weakening (degradation) on the structural response of a composite beam are summarized. The structural responses of interest include: (1) bending, (2) buckling, (3) free vibrations, (4) periodic excitation, and (5) impact. Finite element analysis was used for the computational evaluations. The interply layer degradation effects on the various structural responses were determined and assessed as a function of the interply layer modulus varying from 1 million psi down to 1000 psi and even lower for some limiting cases. The results obtained show that the interply layer degradation has generally negligible effectss on composite structural response and, therefore, structural integrity, unless the interply layer modulus degrades to about 10,000 psi or less.
An (N-1)-resilient algorithm for distributed termination detection

The paper presents a fault tolerant termination detection algorithm based on a previous fault sensitive scheme by Dijkstra and Scholten. The proposed algorithm can tolerate any number of crash failures. It runs as efficiently as its nonfault tolerant predecessor if no process actually fails during the computation, and otherwise incurs only a small amount of cost for each actual failure. It is assumed that the underlying communication network provides such services as reliable end to end communication, failure detection, and fail flush. >
Disrupting Demand for Commercial Seed: Input Subsidies in Malawi and Zambia

Summary This study uses nationally representative household-level panel data from Malawi and Zambia to identify the determinants of subsidized maize seed and fertilizer receipt, and to estimate how input subsidies affect households’ commercial purchases of improved maize seed varieties. In both countries we find that households in areas where the ruling party won the last presidential election acquire significantly more subsidized inputs than other households. Results also indicate that each additional kilogram of subsidized maize seed acquired by a household reduces its commercial improved maize seed purchases by 0.58 kg in Malawi and by 0.49 kg in Zambia on average.
Patient Preferences in Controlling Access to Their Electronic Health Records: a Prospective Cohort Study in Primary Care

Introduction Previous studies have measured individuals’ willingness to share personal information stored in electronic health records (EHRs) with health care providers, but none has measured preferences among patients when they are allowed to determine the parameters of provider access.
Achieving extensibility through product-lines and domain-specific languages: a case study

This is a case study in the use of product-line architectures (PLAs) and domain-specific languages (DSLs) to design an extensible command-and-control simulator for Army fire support. The reusable components of our PLA are layers or "aspects" whose addition or removal simultaneously impacts the source code of multiple objects in multiple, distributed programs. The complexity of our component specifications is substantially reduced by using a DSL for defining and refining state machines, abstractions that are fundamental to simulators. We present preliminary results that show how our PLA and DSL synergistically produce a more flexible way of implementing state-machine-based simulators than is possible with a pure Java implementation.
Collisional relaxation of transient vibrational energy distributions in a thermal unimolecular system. The variable encounter method

Abstract A method has been developed, called the Variable Encounter Method, for the study of the relaxation of an initial vibrationally cold ensemble of molecules into a vibrationally hot distribution by a known and variable number of successive collisions with a hot wall. The theory of the experiment is presented. The system studied was the isomerization of 1,1-cyclopropane- d 2 with a fused quartz wall temperature of 800 K to 1175 K, and average number of collisions from 2.3 to 22.3. Various modified gaussian and exponential models of energy transfer were found to give agreement with the data. The average down-step size was found to decline from ≤ 3500 cm −1 at the lowest temperature to ≈ 2500 cm − at the highest on the basis of a gaussian model. A mathematical analysis of the relation between mean first passage times and incubation times is given. Incubation times increase from ≈ 7 to ≈ 12 collisions with increasing temperature. Transient population distributions and the sequential reaction probabilities as a function of collision number are calculated.
Phenotypic and genotypic diversity of similar serotypes of soybean bradyrhizobia from two soil populations

Abstract The physiological and genetic diversity within two major serotypic groups of bradyrhizobial isolates obtained from soybean (Glycine max L. Merr.) plants grown on a Dothan and a Cape Fear soil was examined. All isolates serotyped as 31 94 had large colonies with smooth borders and high resistances to erythromycin, streptomycin and spectinomycin with minimal inhibitory concentration values (MIC) ranging from 200 to 400 μg ml−1. Pulsed-field gel-electrophoresis (PFGE) separation of DNA fragments generated with the rarely cutting restriction endonuclease, Xba I, revealed six genotypes among 28 different 31 94 isolates. Four of these genotypes were common to both soils and only 21% of the isolates were classified as having high N2-fixation capacity. Leaf chlorosis was induced by 46% of the 31 94 isolates. Among the 122 124 isolates, MIC values were lower than for 31 94 isolates ranging from 122 124 isolates produced small colonies (50%) and large colonies with rough borders (50%) when plated on YEM. The genetic diversity of serotype 122 124 isolates differed with soil type as PFGE patterns revealed nine genotypes among the 16 isolates from the mineral organic (Cape Fear) soil and only three genotypes among the 14 isolates from the sandy mineral (Dothan) soil. Only two of the 12 genotypes were common to both soils. Sixty percent of the 122 124 isolates were classified as having high N2-fixation capacity and none induced foliar chlorosis. Pulsed-field gel-electrophoresis pattern was the only trait that generated groups of isolates that were similar with respect to other measured traits.
Isomorphisms preserving invariants

Let V and W be finite dimensional real vector spaces and let $${G \subset {\rm GL}(V)}$$ and $${H \subset {\rm GL}(W)}$$ be finite subgroups. Assume for simplicity that the actions contain no reflections. Let Y and Z denote the real algebraic varieties corresponding to $${\mathbb{R}[V]^G}$$ and $${\mathbb{R}[W]^H}$$ , respectively. If V and W are quasi-isomorphic, i.e., if there is a linear isomorphism L : V → W such that L sends G-orbits to H-orbits and L −1 sends H-orbits to G-orbits, then L induces an isomorphism of Y and Z. Conversely, suppose that f : Y → Z is a germ of a diffeomorphism sending the origin of Y to the origin of Z. Then we show that V and W are quasi-isomorphic, This result is closely related to a theorem of Strub [8], for which we give a new proof. We also give a new proof of a result of Kriegl et al. [3] on lifting of biholomorphisms of quotient spaces.
Mental Models at Work Cognitive Causes and Consequences of Conflict in Organizations

This research investigated the reciprocal relationship between mental models of conflict and various forms of dysfunctional social relations in organizations, including experiences of task and relationship conflicts, interpersonal hostility, workplace ostracism, and abusive supervision. We conceptualize individual differences in conflict construals as reflecting variation in people’s belief structures about conflict and explore how different elements in people’s associative networks—in particular, their beliefs about their best and worst strategy in conflict—relate to their personality, shape their experiences of workplace conflict, and influence others’ behavioral intentions toward them. Five studies using a variety of methods (including cross-sectional surveys, a 12-week longitudinal diary study, and an experiment) show that the best strategy beliefs relate in theoretically meaningful ways to individuals’ personality, shape social interactions and relationships significantly more than the worst strategy...
The Development and Meaning of Appropriateness Guidelines

Practice guidelines are important for high quality and economical patient care. As gatekeepers to health care, primary care physicians should refer to imaging guidelines when treating a patient with breast disease. The American College of Radiology (ACR) has undertaken the task of publishing guidelines for breast imaging in the hopes of avoiding a plethora of competing, possibly contradictory guidelines written by groups less qualified in imaging protocol than the ACR and with the goal of minimizing the dilemmas of interpretation and patient management often present in breast imaging.
Alopecia associated with unexpected leakage from electron cone

Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region.
Distributed nonlinear control of diffusion-reaction processes

In this work, we focus on distributed control of quasi-linear parabolic partial differential equations (PDEs) and address the problem of enforcing a prespecified spatio-temporal behaviour in the closed-loop system using nonlinear feedback control and a sufficiently large number of actuators and sensors. Under the assumption that the desired spatio-temporal behaviour is described by a ‘target parabolic PDE’, we use a combination of Galerkin's method and nonlinear control techniques to design nonlinear state and static output feedback controllers to address this problem. We use examples of diffusion–reaction processes to demonstrate the formulation of the control problem and the effectiveness of our systematic approach to creating prespecified spatio-temporal behaviour. Using these illustrative examples, we demonstrate that both (a) a sufficiently large number of actuators/sensors, and (b) nonlinear control laws are needed to achieve this goal. Copyright © 2004 John Wiley & Sons, Ltd.
Air Oxidation of N-Cyclopropylanilines

Abstract Air oxidation of N-cyclopropylanilines was shown to occur under either ambient conditions or accelerated conditions (warming or shining light) in an open container. A subsequent fragmentation resulted in formation of the corresponding acetamide. While potential mechanisms have been previously proposed, simple aerobic oxidation to β-hydroxy-propionamides in the absence of a radical promoter has not been previously reported.
Evolution of globular clusters including a degenerate component

Low mass X-ray sources observed in many globular clusters are usually interpreted as compact binaries with degenerate components (e.g., Hertz and Grindlay 1983). Degenerate stars can exist in globular clusters if the IMF contains a sufficiently large number of high mass stars. Since the main-sequence lifetime is a very steep function of stellar mass, most of degenerate stars can be regarded as primordial. If the typical mass of degenerate stars is higher than that of main-sequence stars, mass segregation makes the core crowded with degenerate stars. Tidally captured binaries between degenerates and main-sequence stars can abundantly form as the core density becomes very high.
The absolute configuration of trilobacin and trilobin, a novel highly potent acetogenin from the stem bark of Asimina triloba (Annonaceae)

Abstract Trilobacin ( 1 ) is the only previously reported Annonaceous acetogenin with the erythro relative configuration between the adjacent bis-tetrahydrofuran (THF) rings. The relative configuration in the adjacent bis-THF moiety of 1 was corrected to threo/trans/erythro/cis/threo from C-15 to C-24, and the absolute configuration was determined as 4 R , 15 R , 16 R , 19 R , 20 S , 23 R , 24 R and 36 S by advanced Mosher ester methodology and the COSY and NOESY spectral analyses of its 4,24-diacetate ( 1a ). Further investigation of the EtOH extract of the stem bark of the paw paw tree, Asimina triloba , monitoring for bioactivity by brine shrimp lethality, led to a novel acetogenin, trilobin ( 2 ). Spectral and chemical methods identified 2 as a 4-deoxy-10-hydroxy isomer of 1 . The absolute configuration of 2 was determined as 10 R , 15 R , 16 R , 19 R , 20 S , 23 R , 24 R , and 36 S by analyses of its Mosher ester derivatives. 2 was selectively cytotoxic among three human solid tumor cell lines with over a billion times the potency of adriamycin.
Single particle jumps in a binary Lennard-Jones system below the glass transition.

We study a binary Lennard-Jones system below the glass transition with molecular dynamics simulations. To investigate the dynamics we focus on events (jumps) where a particle escapes the cage formed by its neighbors. Using single particle trajectories we define a jump by comparing for each particle its fluctuations with its changes in average position. We find two kinds of jumps: “reversible jumps,” where a particle jumps back and forth between two or more average positions, and “irreversible jumps,” where a particle does not return to any of its former average positions, i.e., successfully escapes its cage. For all investigated temperatures both kinds of particles jump and both irreversible and reversible jumps occur. With increasing temperature, relaxation is enhanced by an increasing number of jumps and growing jump lengths in position and potential energy. However, the waiting time between two successive jumps is independent of temperature. This temperature independence might be due to aging, which is present in our system. We therefore also present a comparison of simulation data with three different histories. The ratio of irreversible to reversible jumps is also increasing with increasing temperature, which we interpret as a consequence of the increased likelihood of changes in the cages, i.e., a blocking of the “entrance” back into the previous cage. In accordance with this interpretation, the fluctuations both in position and energy are increasing with increasing temperature. A comparison of the fluctuations of jumping particles and nonjumping particles indicates that jumping particles are more mobile even when not jumping. The jumps in energy normalized by their fluctuations are decreasing with increasing temperature, which is consistent with relaxation being increasingly driven by thermal fluctuations. In accordance with subdiffusive behavior are the distributions of waiting times and jump lengths in position.
Solar Cycle Variation of the Sun’s Low-Order Magnetic Multipoles: Heliospheric Consequences

The Sun’s dipole and quadrupole components play a central role in the solar cycle evolution of the interplanetary magnetic field (IMF). The long-term variation of the radial IMF component approximately tracks that of the total dipole moment, with additional contributions coming near sunspot maximum from the quadrupole moment and from CMEs. The axial and equatorial components of the dipole vary out of phase with each other over the solar cycle. The equatorial dipole, whose photospheric sources are subject to rotational shearing, decays on a timescale of ∼1 yr and must be continually regenerated by new sunspot activity; its fluctuating strength depends not only on the activity level, but also on the longitudinal phase relationships among the active regions. During cycles 21–23, the equatorial dipole and IMF reached their peak strength ∼2 yrs after sunspot maximum; conversely, large dips or “Gnevyshev gaps” occurred when active regions emerged longitudinally out of phase with each other. The 10Be-inferred phase shift in the IMF variation during the Maunder Minimum may be explained by a decrease in the amplitude of the equatorial dipole relative to the axial dipole, due either to a systematic weakening of the emerging bipoles or to an increase in their tilt angles. In mid-2012, during the polarity reversal of cycle 24, the nonaxisymmetric quadrupole component became so dominant that the heliospheric current sheet (HCS) split into two cylindrical components. Hemispheric asymmetries in sunspot activity give rise to an axisymmetric quadrupole component, which has combined with the axial dipole to produce a systematic southward displacement of the HCS since cycle 20.
Ground-Coupled Heat and Moisture Transfer from Buildings Part 2–Application

In this paper the effects of moisture on the heat transfer from two basic types of building foundations, a slab-on-grade and a basement, are examined. A two-dimensional finite element heat and moisture transfer program is used to show the effects of precipitation, soil type, foundation insulation, water table depth, and freezing on the heat transfer from the building foundation. Comparisons are made with a simple heat conduction model to illustrate the dependency of the soil thermal conductivity on moisture content.
Duality relations among topological effects in string theory

We explore two different problems in string theory in which duality relates an ordinary p-form field in one theory to a self-dual (p+1)-form field in another theory. One problem involves comparing D4-branes to M5-branes, and the other involves comparing the Ramond-Ramond forms in type-IIA and type-IIB superstring theory. In each case, a subtle topological effect involving the p-form can be recovered from a careful analysis of the quantum mechanics of the self-dual (p+1)-form.
An empirical model to predict the 1-AU arrival of interplanetary shocks

Abstract We extend the empirical coronal mass ejection (CME) arrival model of Gopalswamy et al. [Gopalswamy, N. et al. Predicting the 1-AU arrival times of coronal mass ejections, J. Geophys. Res. 106, 29207, 2001] to predict the 1-AU arrival of interplanetary (IP) shocks. A set of 29 IP shocks and the associated magnetic clouds observed by the Wind spacecraft are used for this study. The primary input to this empirical shock arrival model is the initial speed of white-light CMEs obtained using coronagraphs. We use the gas dynamic piston–shock relationship to derive the ESA model which provides a simple means of obtaining the 1-AU speed and arrival times of interplanetary shocks using CME speeds.
A convex polynomial that is not sos-convex

A multivariate polynomial p(x) = p(x 1, . . . , x n ) is sos-convex if its Hessian H(x) can be factored as H(x) = M T (x) M(x) with a possibly nonsquare polynomial matrix M(x). It is easy to see that sos-convexity is a sufficient condition for convexity of p(x). Moreover, the problem of deciding sos-convexity of a polynomial can be cast as the feasibility of a semidefinite program, which can be solved efficiently. Motivated by this computational tractability, it is natural to study whether sos-convexity is also a necessary condition for convexity of polynomials. In this paper, we give a negative answer to this question by presenting an explicit example of a trivariate homogeneous polynomial of degree eight that is convex but not sos-convex.
NOTES ON THE KINEMATIC STRUCTURE OF THE THREE-FLAVOR NEUTRINO OSCILLATION FRAMEWORK

These notes present a critique of the standard three-flavor neutrino oscillation framework. The design proposal of the MINOS at Fermilab based on a two-mass eigenstate framework may require serious reconsideration if there is strong mixing between all three flavors of neutrinos. For the LSND and KARMEN neutrino oscillation experiments, the amplitude of neutrino oscillation of the "one mass scale dominance" framework vanishes for certain values of mixing angles as a result of opposite signs of two equal and opposite contributions. Recent astronomical observations leave open the possibility that one of the neutrino mass eigenstates may be nonrelativistic in some instances. Neutrino oscillation phenomenology with a superposition of two relativistic, and one nonrelativistic, mass eigenstates is constructed. It is concluded that if the transition from the nonrelativistic to the relativistic regime happens for energies relevant to the reactor and the LSND neutrino oscillation experiments, then one must consider an ab initio analysis of the existing data.
Visible light-initiated interfacial thiol-norbornene photopolymerization for forming an islet surface conformal coating

A cytocompatible visible light-mediated interfacial thiol-norbornene photopolymerization scheme was developed for creating a hydrogel conformal coating on pancreatic islets. The step-growth thiol-norbornene reaction provides high consistency and tunability to gel coating thickness. Furthermore, isolated islets coated with thiol-norbornene gel maintained their viability and function in vitro.
The lifetime and evolution of fibrils

A detailed study was made of the lifetimes and evolution of fibrils in McMath 12417, using high resolution filtergrams in H alpha and CaII K made at Big Bear Solar Observatory. It was found that the lifetime of a fibril increases monotonically with its length. This relationship, together with the form of the variation of fibril lengths as a function of time, suggests that fibrils result from material being impulsively injected into magnetic field lines at approximately 30 km/sec, and returning under gravity. The lifetimes and apparent lengths of fibrils are then a function of the inclination of the field lines only. A study of wavelength scans through the H alpha line confirms that the apparent expansion and contraction of fibrils represents true mass motion.
Addressable Terminally-Linked DNA-CNT Nanowires

Despite many advances in carbon nanotube (CNT) research, several issues continue to plague the field with regard to the construction of well-defined hybrid CNT materials. Regiospecific covalent functionalization, nonspecific surface absorption, and carbon nanotube aggregation/bundling present major difficulties when working with these materials. In this communication, we circumvent these problems and report a new addressable hybrid material composed of single-walled carbon nanotubes terminally linked by oligonucleotides into a nanowire motif. We show that the oligonucleotide junctions are addressable and can be targeted by gold nanoparticles.
Assessing tropical cyclone trends in the context of potential sampling biases

[1] Recently observed trends in the tropical cyclone record are assessed in the context of potential sampling biases. Multi-member syntheses of the hurricane record are created and subjected to time-varying sampling rates and intensity-specific biases to assess the biases' ability to induce spurious trends. While simple linear trends in sampling frequency can be imposed that account for the observed trends in major storms, the same biases result in trends in weaker storms that are significantly at odds with observations. Moreover, it is found that intensity specific biases, which must invariably contribute to prolonged storm durations for weaker categories, are inconsistent with observations. It is concluded therefore that the proposed sampling deficiencies are unable to account fully for recently reported trends, either individually or when considered in tandem. The finding of positive trends must therefore either be robust or result from complex, and as of yet unexplained, sampling biases.
A tight characterization of the performance of static solutions in two-stage adjustable robust linear optimization

In this paper, we study the performance of static solutions for two-stage adjustable robust linear optimization problems with uncertain constraint and objective coefficients and give a tight characterization of the adaptivity gap. Computing an optimal adjustable robust optimization problem is often intractable since it requires to compute a solution for all possible realizations of uncertain parameters (Feige et al. in Lect Notes Comput Sci 4513:439---453, 2007). On the other hand, a static solution is a single (here and now) solution that is feasible for all possible realizations of the uncertain parameters and can be computed efficiently for most dynamic optimization problems. We show that for a fairly general class of uncertainty sets, a static solution is optimal for the two-stage adjustable robust linear packing problems. This is highly surprising in view of the usual perception about the conservativeness of static solutions. Furthermore, when a static solution is not optimal for the adjustable robust problem, we give a tight approximation bound on the performance of the static solution that is related to a measure of non-convexity of a transformation of the uncertainty set. We also show that our bound is at least as good (and in many case significantly better) as the bound given by the symmetry of the uncertainty set (Bertsimas and Goyal in Math Methods Oper Res 77(3):323---343, 2013; Bertsimas et al. in Math Oper Res 36(1):24---54, 2011).
A Model for a Thermally Induced Polymer Coil-to-Globule Transition

A semiquantitative mean-field model for the thermally induced (heating-induced) polymer coil-to-globule transition (HCGT) is developed with no adjustable parameters. The transition temperature Θ is given for a long chain by the equation Θ = 2Tp*[1 − ρB(Θ)], where Tp* is the characteristic temperature of the polymer and ρB(Θ) is the bulk solvent density at the transition temperature. The variables ρB and Tp* are obtained by invoking the Sanchez−Lacombe (S−L) equation of state. Calculated HCGT temperatures show good agreement with experimental lower critical solution temperatures (LCSTs). The predicted globular state is characterized by the dominance of attractive polymer self-interactions over excluded volume interactions. There is a critical value of the ratio of polymer to solvent S−L characteristic temperature below which no HCGT transition is predicted for an infinite chain. This model can be easily generalized to treat cross-linked gels and their contraction−expansion characteristics.
Peridinin--Chlorophyll a Proteins from the Symbiotic Dinoflagellate Symbiodinium (= Gymnodinium) microadriaticum, Freudenthal

The conformers of peridinin--chorophyll a proteins (PCP), isolated from various strains of the symbiotic dinoflagellate Symbiodinium (= Gymnodinium) microadriaticum and analysed by isoelectric focusing in polyacrylamide gels, exhibited different patterns. In most instances the same pattern of conformers was found in each strain when freshly isolated from their respective hosts, after culture, and in two instances also after cloning. These observations suggest that characteristic patterns of PCP are diagnostic of particular strains of S. microadriaticum. Evidence is presented that generally the patterns do not change with environment. Analysis of PCP could potentially serve as a tool for the identification of strains of S. microadriaticum and could also serve as a marker for the empirical analysis of sexual recombination.
Multi-dimensional solidification with internal radiation and temperature dependent properties

Abstract In this study, a two-dimensional radial and axial analytical model was developed and solved to determine the transient temperature distribution and interface location of a semi-transparent, gray, absorbing, emitting and isotropically scattering phase change medium bounded by two finite concentric cylinders when internal energy transfer occurs simultaneously by conduction and thermal radiation. The phase change medium employed in this study was a fluoride salt with a weight composition of LiF — 41.27%, MgF 2 — 48.76% and KF — 8.95%. The principle of conservation of energy where enthalpy and temperature are the dependent variables was coupled with a set of moment equations that were derived from radiative transfer equations and Marshak type boundary conditions by applying the spherical harmonics or P-1 differential approximation. An iterative finite difference numerical scheme was used to solve the non-linear difference equations. Results that show the effects of internal radiation on the temperature distribution, the rate of solidification and the heat extracted are presented. It is seen that internal radiation tends to accelerate the solidification process.
Chemical evolution XXIX. Pyrimidines from hydrogen cyanide.

Abstract Dilute (0.1 M) solutions of HCN condense to oligomers at pH 8–9. Hydrolysis of these oligomers at pH 8.5 or with 6 N HCl yields 4,5-dihydroxypyrimidine, as the most abundant pyrimidine product along with orotic acid and 5-hydroxyuracil. These results, together with the earlier data, demonstrate that the three major nitrogen-containing classes of biomolecules could have originated from HCN on the primitive earth. The observation of the formation of orotic acid and 4-aminoimidazole-5-carboxamide by the hydrolysis of the HCN oligomers suggests that once the initially formed pyrimidines and purines were consumed, those life forms persisted which evolved enzymes for the conversion of these intermediates to the pyrimidines and purines present in contemporary RNA.
Quark correlations and single spin asymmetries

We analyze the Sivers asymmetry in the light-cone gauge. The average transverse momentum of the quark distribution is related to the correlation between the quark distribution and the transverse component of the gauge field at ${x}^{\ensuremath{-}}=\ifmmode\pm\else\textpm\fi{}\ensuremath{\infty}.$ We then use finiteness conditions for the light-cone Hamiltonian to relate the transverse gauge field at ${x}^{\ensuremath{-}}=\ifmmode\pm\else\textpm\fi{}\ensuremath{\infty}$ to the color density integrated over ${x}^{\ensuremath{-}}.$ This result allows us to relate the average transverse momentum of the active quark to color charge correlations in the transverse plane.
Lipschitz minimality of the multiplication maps of unit complex, quaternion and octonion numbers

We prove that the multiplication maps S n S n ! S n (nD 1;3;7) for unit complex, quaternion and octonion numbers are, up to isometries of domain and range, the unique Lipschitz constant minimizers in their homotopy classes. Other geometrically natural maps, such as projections of Hopf fibrations, have already been shown to be, up to isometries, the unique Lipschitz constant minimizers in their homotopy classes, and it is suspected that this may hold true for all Riemannian submersions of compact homogeneous spaces. Using a counterexample, we also show that being a Riemannian submersion alone without further assumptions (like homogeneity) does not guarantee the map to be the unique Lipschitz constant minimizer in its homotopy class up to isometries, even when the receiving space is just a circle. 53C23; 53C30, 55R25, 53C43
Use of photodetectors for the measurement of carrier velocities in wide-bandgap semiconductors

We present an optically-detected time-of-flight technique with femtosecond resolution that monitors the change in the electroabsorption due to charge transport in a p-i-n diode, and show how it may be used to determine the electron transit time, velocity-field characteristic, and transient electron velocity overshoot in GaN at room temperature. In a GaN homojunction p-i-n diode, the peak electron velocity of 1.9x10 7 cm/s , corresponding to a transit time of ~2.5 ps across the 0.53 micrometers depletion region, is attained at ~ 225 kV/cm. The steady-state velocity-field characteristic is in qualitative agreement with theoretical calculations. A measurement of the high field transient electron velocity overshoot was also performed using a semi-transparent p-contact AlGaN/GaN heterojunction p-i-n diode. Transient electron velocity overshoot is observed at fields as low as ~100 kV/cm, with the peak transient electron velocity becoming larger with increasing electric field until a maximum of 7.25x10 7 cm/s is observed within the first 200 fs after photoexcitation at a field of 320 kV/cm. At higher fields, the measurement of the peak velocity is limited by the 80 fs duration of the pulses, but the increase in transit time with increasing field suggests the onset of negative differential resistance. Theoretical Monte Carlo calculations incorporating a GaN full-zone band structure show that although the peak steady-state velocity occurs at ~200 kV/cm, the ensuing negative differential resistance region of the velocity-field curve is not initially associated with intervalley transfer, as the majority of electrons do not attain sufficient energy to effect this transfer until they are subjected to much higher fields (>325kV/cm). Insight into this behavior can be gleaned from the band nonparabolicity deduced from the constant energy surfaces in the (Gamma) valley, which shows that the effective mass in the c-direction can be viewed as becoming larger at high k-values. This larger effective mass may play a role in velocity overshoot by reducing the velocity and momentum relaxation time at high k-values in the (Gamma) valley. Theoretical calculations employing a semiclassical transport model in the collisionless regime confirm the importance of this nonparabolicity for the determination of the temporal shape of the transient velocity overshoot curves.
High pressure study of 1,3,5-trimethylbenzene oxidation

Abstract The high pressure and high temperature kinetics of the 1,3,5-trimethylbenzene oxidation were investigated in the High Pressure Single Pulse Shock Tube at University of Illinois at Chicago. Experiments were performed at nominal reflected shock pressures of 20 and 50 atm, for three different equivalence ratios (Ф = 0.51, 0.95 and 1.86) and for a temperature range of 1017–1645 K. A variety of stable species ranging from aliphatic hydrocarbons to single ring and polycyclic aromatic hydrocarbons were sampled from the shock tube and analyzed using standard gas chromatographic techniques. A detailed chemical kinetic model was developed to simulate the fuel and oxygen decay and the stable intermediate species profiles as obtained from the high pressure oxidation experiments. The model shows satisfactory predictions for the formation and consumption of most of the major intermediates.
A Pilot Study to Develop a Diagnostic Test for Pancreatic Ductal Adenocarcinoma Based on Differential Expression of Select miRNA in Plasma and Bile

A Pilot Study to Develop a Diagnostic Test for Pancreatic Ductal Adenocarcinoma Based on Differential Expression of Select miRNA in Plasma and Bile
Unified formalism for calculating polarization, magnetization, and more in a periodic insulator

In this paper, we propose a unified formalism, using Green's functions, to integrate out the electrons in an insulator under uniform electromagnetic fields. We derive a perturbative formula for the Green's function in the presence of uniform magnetic or electric fields. By applying the formula, we derive the formula for the polarization, the orbital magnetization, and the orbital magnetopolarizability, without assuming time-reversal symmetry. Specifically, we realize that the terms linear in the electric field can only be expressed in terms of the Green's functions in one extra dimension. This observation directly leads to the result that the coefficient of the $\ensuremath{\theta}$ term in any dimensions is given by a Wess-Zumino-Witten--type term, integrated in the extended space, interpolating between the original physical Brillouin zone and a trivial system, with the group element replaced by the Green's function. This generalizes an earlier result for the case of time-reversal invariance [see Z. Wang, X.-L. Qi, and S.-C. Zhang, Phys. Rev. Lett. 105, 256803 (2010)].
Strain and resonance energies in main-group homoatomic rings and clusters

Abstract A summary of recent progress in the estimation of strian and resonance energy parameters that apply to structures composed of representative elements other than carbon, including silicon, nitrogen, phosphorus, oxygen, sulfur and, to a limited extent, arsenic.
Limit theorems for a Cox-Ingersoll-Ross process with Hawkes jumps

In this paper we propose a stochastic process, which is a Cox-Ingersoll-Ross process with Hawkes jumps. It can be seen as a generalization of the classical Cox-Ingersoll-Ross process and the classical Hawkes process with exponential exciting function. Our model is a special case of the affine point processes. We obtain Laplace transforms and limit theorems, including the law of large numbers, central limit theorems, and large deviations.
The investment opportunity set and corporate financing, dividend, and compensation policies☆

Abstract We examine explanations for corporate financing-, dividend-, and compensation-policy choices. We document robust empirical relations among corporate policy decisions and various firm characteristics. Our evidence suggests contracting theories are more important in explaining cross-sectional variation in observed financial, dividend, and compensation policies than either tax-based or signaling theories.
Iterative-deepening search with on-line tree size prediction

The memory requirements of best-first graph search algorithms such as A* often prevent them from solving large problems. The best-known approach for coping with this issue is iterative deepening, which performs a series of bounded depth-first searches. Unfortunately, iterative deepening only performs well when successive cost bounds visit a geometrically increasing number of nodes. While it happens to work acceptably for the classic sliding tile puzzle, IDA* fails for many other domains. In this paper, we present an algorithm that adaptively chooses appropriate cost bounds on-line during search. During each iteration, it learns a model of the search tree that helps it to predict the bound to use next. Our search tree model has three main benefits over previous approaches: (1) it will work in domains with real-valued heuristic estimates, (2) it can be trained on-line, and (3) it is able to make more accurate predictions with only a small number of training examples. We demonstrate the power of our improved model by using it to control an iterative-deepening A* search on-line. While our technique has more overhead than previous methods for controlling iterative-deepening A*, it can give more robust performance by using its experience to accurately double the amount of search effort between iterations.
The First Applications of Carbene Ligands in Cross-Couplings of Alkyl Electrophiles: Sonogashira Reactions of Unactivated Alkyl Bromides and Iodides

A Pd/N-heterocyclic carbene-based catalyst achieves the Sonogashira coupling of an array of functionalized, β-hydrogen-containing alkyl bromides and iodides under mild conditions. By furnishing the first example of a nonphosphine-based palladium catalyst for cross-coupling unactivated alkyl electrophiles, this study provides an impetus for future efforts at catalyst development that extend beyond phosphine ligands.
Charge stripes and antiferromagnetism in insulating nickelates and superconducting cuprates

Abstract Neutron and X-ray scattering studies have provided strong evidence for coupled spatial modulations of charge and spin densities in layered nickelates and cuprates. The accumulated results for La 2− x Sr ix NiO 4+δ are consistent with the strongly modulated topological-stripe concept. Clues from Nd-doped La 2− x Sr x CuO 4 suggest similar behavior for the cuprates. The experimental results are summarized, and features that conflict with an interpretation based on a Fermi-surface instability are emphasized. A rationalization for the differences in transport properties between the cuprates and nickelates is given.