cssi/SciSciGPT-SciSciNet huggingface dataset:
On regret of parametric mismatch in minimum mean square error estimation

This paper studies the effect of parametric mis-match in minimum mean square error (MMSE) estimation. In particular, we consider the problem of estimating the input signal from the output of an additive white Gaussian channel whose gain is fixed, but unknown. The input distribution is known, and the estimation process consists of two algorithms. First, a channel estimator blindly estimates the channel gain using past observations. Second, a mismatched MMSE estimator, optimized for the estimated channel gain, estimates the input signal. We analyze the regret, i.e., the additional mean square error, that is raised in this process. We derive upper-bounds on both absolute and relative regrets. Bounds are expressed in terms of the Fisher information. We also study regret for unbiased, efficient channel estimators, and derive a simple trade-off between Fisher information and relative regret. This trade-off shows that the product of a certain function of relative regret and Fisher information equals the signal-to-noise ratio, independent of the input distribution. The trade-off relation implies that higher Fisher information results to smaller expected relative regret.
Identification of Post-Translational Modifications by Mass Spectrometry

Proteins are the effector molecules of many cellular and biological processes and are thus very dynamic and flexible. Regulation of protein activity, structure, stability, and turnover is in part controlled by their post-translational modifications (PTMs). Common PTMs of proteins include phosphorylation, glycosylation, methylation, ubiquitination, acetylation, and oxidation. Understanding the biology of protein PTMs can help elucidate the mechanisms of many pathological conditions and provide opportunities for prevention, diagnostics, and treatment of these disorders. Prior to the era of proteomics, it was standard to use chemistry methods for the identification of protein modifications. With advancements in proteomic technologies, mass spectrometry has become the method of choice for the analysis of protein PTMs. In this brief review, we will highlight the biochemistry of PTMs with an emphasis on mass spectrometry.
The Enrichment History of Hot Gas in Poor Galaxy Groups

We have analyzed the ASCA SIS and GIS data for 17 groups and determined the average temperature and abundance of the hot X-ray-emitting gas. For groups with gas temperatures less than 1.5 keV, we find that the abundance is correlated with the gas temperature and luminosity. We have also determined the abundance of the α-elements and iron independently for those groups with sufficient counts. We find that for the cool groups (i.e., kT<1.5 keV) the ratio of α-elements to iron is ~1, which is about half that seen in clusters. Spectral fits with the S, Si, and Fe abundances allowed to vary separately suggest the S/Fe ratio is similar to that seen in clusters, while the Si/Fe ratio in groups is half the value determined for richer systems. The mass of metals per unit of blue luminosity drops rapidly in groups as the temperature drops. There are two possible explanations for this decrease. One is that the star formation in groups is very different from that in rich clusters. The other explanation is that groups lose much of their enriched material via winds during the early evolution of ellipticals. If the latter is true, we find that poor groups will have contributed significantly (roughly one-third of the metals) to the enrichment of the intergalactic medium.
Compressing thin spheres in the complement of a link

Abstract Let L be a link in S 3 that is in thin position but not in bridge position and let P be a thin level sphere with compressing disk D . We introduce the idea of alternating level spheres for D and show that all such spheres are thin and their widths are monotone decreasing. This allows us to generalize a result of Wu by giving a bound on the number of disjoint irreducible compressing disks P can have in terms of the width of P , including identifying thin spheres with unique compressing disks. We also give conditions under which P must be incompressible on some side or be weakly incompressible. In particular we show that the thin level sphere of second lowest width is weakly incompressible. If P is strongly compressible we describe how a pair of compressing disks must lie relative to the link.
Omega-3 fatty acid supplementation to prevent recurrent preterm birth: a randomized controlled trial.

OBJECTIVE To assess whether the addition of an omega-3 long-chain polyunsaturated fatty acid supplement would reduce preterm birth in women with at least one prior spontaneous preterm birth receiving 17α-hydroxyprogesterone caproate.
PROCESSING AN OFFLINE INSERTION-QUERY SEQUENCE WITH APPLICATIONS

In this paper, we present techniques and algorithms for processing an offline sequence of update and query operations and for related problems. The update can be either all insertions or all deletions. The types of query include min-gap, max-gap, predecessor, and successor. Most problems we consider are solved optimally in linear time by our algorithms, which are based on new geometric modeling and interesting techniques. We also discuss some applications to which our algorithms and techniques can be applied to yield efficient solutions. These applications include an offline horizontal ray shooting problem and a shortest arc covering problem on a circle.
Big bounce from spin and torsion

The Einstein-Cartan-Sciama-Kibble theory of gravity naturally extends general relativity to account for the intrinsic spin of matter. Spacetime torsion, generated by spin of Dirac fields, induces gravitational repulsion in fermionic matter at extremely high densities and prevents the formation of singularities. Accordingly, the big bang is replaced by a bounce that occurred when the energy density \({\epsilon \propto gT^4}\) was on the order of \({n^2/m_{\rm Pl}^2}\) (in natural units), where \({n \propto gT^3}\) is the fermion number density and g is the number of thermal degrees of freedom. If the early Universe contained only the known standard-model particles (g ≈ 100), then the energy density at the big bounce was about 15 times larger than the Planck energy. The minimum scale factor of the Universe (at the bounce) was about 1032 times smaller than its present value, giving ≈ 50 μm. If more fermions existed in the early Universe, then the spin-torsion coupling causes a bounce at a lower energy and larger scale factor. Recent observations of high-energy photons from gamma-ray bursts indicate that spacetime may behave classically even at scales below the Planck length, supporting the classical spin-torsion mechanism of the big bounce. Such a classical bounce prevents the matter in the contracting Universe from reaching the conditions at which a quantum bounce could possibly occur.
Synthesis and Structure of Technetium Trichloride

Technetium trichloride has been synthesized by reaction of Tc2(O2CCH3)4Cl2 with HCl(g) at 300 °C. The mechanism of formation mimics the one described earlier in the literature for rhenium. Tc2(O2CCH3)2Cl4 [P1; a = 6.0303(12) A, b = 6.5098(13) A, c = 8.3072(16) A, α = 112.082(2)°, β = 96.667(3)°, γ = 108.792(3)°; Tc−Tc = 2.150(1) A] is formed as an intermediate in the reaction at 100 °C. Technetium trichloride is formed above 250 °C and is isostructural with its rhenium homologue. The structure consists of Tc3Cl9 clusters [R3m; a = b = 10.1035(19) A, c = 20.120(8) A], and the Tc−Tc separation is 2.444(1) A. Calculations on TcX3 (X = Cl, Br) have confirmed the stability of TcCl3 and suggest the existence of a polymorph of TcBr3 with the ReBr3 structure.
Design Analysis and Performance Evaluation of a Two Dimensional Camera for Accelerated Positron Emitter Beam Injection by Computer Simulation

The characteristics and design of a high-accuracy and high-sensitivity 2-dimensional camera for the measurement of the end-point of the trajectory of accelerated heavy ion beams of positron emitter isotopes are described. Computer simulation methods have been used in order to insure that the design would meet the demanding criteria of ability to obtain the location of the centroid of a point source in the X-Y plane with errors smaller than 1 mm, with an activity of 100 nanoCi, in a counting time of 5 sec or less. A computer program which can be developed into a 'general purpose' analysis tool for a large number of positron emitter camera configurations is described in its essential parts. The validation of basic simulation results with simple measurements is reported, and the use of the program to generate simulated images which include important second order effects due to detector material, geometry, septa, etc. is demonstrated. Comparison between simulated images and initial results with the completed instrument shows that the desired specifications have been met.
LOGICAL ANALYSIS OF THE BOHR COMPLEMENTARITY PRINCIPLE IN AFSHAR'S EXPERIMENT UNDER THE NAFL INTERPRETATION

The NAFL (non-Aristotelian finitary logic) interpretation of quantum mechanics requires that no "physical" reality can be ascribed to the wave nature of the photon. The NAFL theory QM, formalizing quantum mechanics, treats the superposed state (S) of a single photon taking two or more different paths at the same time as a logical contradiction that is formally unprovable in QM. Nevertheless, in a nonclassical NAFL model for QM in which the law of noncontradiction fails, S has a meaningful metamathematical interpretation that the classical path information for the photon is not available. It is argued that the existence of an interference pattern does not logically amount to a proof of the self-interference of a single photon. This fact, when coupled with the temporal nature of NAFL truth, implies the logical validity of the retroactive assertion of the path information (and the logical superfluousness of the grid) in Afshar's experiment. The Bohr complementarity principle, when properly interpreted with t...
Venture Capital, High Technology and Regional Development∗

FLORIDA R. L. and Kenney M. (1988) Venture capital, high technology and regional development, Reg. Studies 22, 33–48. This paper explores the role of venture capital in technological innovation and regional development. Both aggregate data and a unique firm level data base are employed to determine the location of major centres of venture capital, flows of venture capital investments, and patterns of investment syndication or coinvestment among venture capital firms. Three major centres of venture capital are identified: California (San Francisco–Silicon Valley); New York; and New England (Massachusetts–Connecticut): as well as three minor venture capital centres: Illinois (Chicago); Texas; and Minnesota. Venture capital firms are found to cluster in areas with high concentrations of financial institutions and those with high concentrations of technology-intensive enterprises. Venture capital firms which are based in financial centres are typically export-oriented, while those in technology centres tend t...
Necessary Conditions for Optimality for Paths Lying on a Corner

A class of optimization problems is investigated in which some of the functions, continuous in all their arguments, have continuous right-and left-hand derivatives but are not equal at a point called the corner. For this nonclassical problem, a set of first order necessary conditions for stationarity is determined for an optimal path which may have arcs lying on a corner for a nonzero length of time. Enough conditions are provided to construct an extremal path. This, in part, is achieved by noting that the corner defines a manifold in which the derivatives of all the functions are uniquely defined. Three examples, two of which represent possible aggregate production and employment planning models, illustrate the theory.
Pauli-Villars regularization of supergravity coupled to chiral and Yang-Mills matter

Abstract It is shown that the one-loop quadratic divergences of standard supergravity can be regulated by the introduction of heavy Pauli-Villars fields belonging to chiral and abelian gauge multiplets. The resulting one-loop correction can be interpreted as a renormalization of the Kahler potential. Regularization of the dilaton couplings to the Yang-Mills sector requires special care, and may shed some light on chiral/linear multiplet duality of the dilaton supermultiplet.
The Evolution of Voids in the Expanding Universe

We examine the growth and nonlinear evolution of spherically symmetric, negative density perturbations in an otherwise uniform Friedmann cosmology. In general, the cavity expands and its density relative to the background decreases. In certain cases, the cavity comes to be surrounded by a narrow shell of matter with a density substantially greater than the mean cosmological value; we show that such an overdense shell can form even when no overdense region is present anywhere in the initial density profile. These ''walled-in'' cavities may be identified with recently observed, large-scale holes in the galaxy distribution, and the shells themselves with the superclusters which define the boundaries of such holes. However, we also show that there exist choices for the initial density profile which lead to the formation of deep cavities which are not surrounded by any overdense shells. We examine the behavior of the shell-growth phenomenon under various assumptions about the background universe and the initial density perturbation, and find that shell growth is enhanced for high values of the density parameter ..cap omega.., positive (repulsive) cosmological constant, steep density profile of the initial perturbation, large-amplitude perturbation, and/or early origin of the perturbation. We derive analytic criteria for classifying arbitrary initiallymore » negative density profiles to determine (a) whether shell crossing with formally infinite density will eventually occur for any given comoving mass coordinate, and (b) whether matter at adjacent mass coordinates will form a shell of finite overdensity which persists indefinitely.« less
On Injectivity of Quasiregular Mappings

We give sufficient conditions for a planar quasiregular mapping to be injective in terms of the range of the differential matrix.
Consistent Modeling of Rotating Timoshenko Shafts Subject to Axial Loads

The equations of motion of a flexible rotating shaft have been typically derived by introducing gyroscopic moments, in an inconsistent manner, as generalized work terms in a Lagrangian formulation or as external moments in a Newtonian approach. This paper presents the consistent derivation of a set of governing differential equations describing the flexural vibration in two orthogonal planes and the torsional vibration of a straight rotating shaft with dissimilar lateral principal moments of inertia and subject to a constant compressive axial load. The coupling between flexural and torsional vibration due to mass eccentricity is not considered. In addition, a new approach for calculating correctly the effect of an axial load for a Timoshenko beam is presented based on the change in length of the centroidal line. It is found that the use of either a floating frame approach with the small strain assumption or a finite strain beam theory is necessary to obtain a consistent derivation of the terms corresponding to gyroscopic moments in the equations of motion. However, the virtual work of an axial load through the geometric shortening appears consistently in the formulation only when using a finite strain beam theory.
Theory of Itinerant Ferromagnets Exhibiting Localized-Moment Behavior above the Curie Point

By using a functional integral formulation of the theory of itinerant ferromagnets above the Curie point, we show that for strong Coulomb interaction $U$, there are localized moments exhibiting a characteristic Curie-law susceptibility with the correct free spin-\textonehalf{} limiting value of the Curie constant. For weak $U$ the same formulation gives a Pauli-like susceptibility, again with the proper limit, while for intermediate values the theory gives a smooth interpolation between the extreme cases.
Dynamic Control of Centrifugal Compressor Surge Using Tailored Structures

A new method for dynamic control of centrifugal compressor surge is presented. The approach taken is to suppress surge by modifying the compression system dynamic behavior using structural feedback. More specifically, one wall of a downstream volume, or plenum, is constructed so as to move in response to small perturbations in pressure. This structural motion provides a means for absorbing the unsteady energy perturbations produced by the compressor, thus extending the stable operating range of the compression system. In the paper, a lumped parameter analysis is carried out to define the coupled aerodynamic and structural system behavior and the potential for stabilization. First-of-a-kind experiments are then conducted to examine the conclusions of the analysis. As predicted by the model and demonstrated by experiment, a movable plenum wall lowered the mass flow at which surge occurred in a centrifugal compression system by roughly 25 percent for a range of operating conditions. In addition, because the tailored dynamics of the structure acts to suppress instabilities in their initial stages, this control was achievable with relatively little power being dissipated by the movable wall system, and with no noticeable decrease in steady-state performance. Although designed on the basis of linear system considerations, the structural control is shown to be capable of suppressing existing large-amplitude limit cycle surge oscillations.
Domino Tilings with Barriers

In this paper, we continue the study of domino-tilings of Aztec diamonds. In particular, we look at certain ways of placing “barriers” in the Aztec diamond, with the constraint that no domino may cross a barrier. Remarkably, the number of constrained tilings is independent of the placement of the barriers. We do not know of a simple combinatorial explanation of this fact; our proof uses the Jacobi?Trudi identity.
Metadata and the Future of Cataloging.

This article is a survey of representative metadata efforts comparing them to MARC 21 metadata in order to determine if new electronic formats require the development of a new set of standards. This study surveys the ongoing metadata projects in order to identify what types of metadata exist and how they are used and also compares and analyzes selected metadata elements in an attempt to illustrate how they are related to MARC 21 metadata format elements.
Aspects of Organoselenium Chemistry

Monoselenophosphate, SePO3H3-n n-, has been chemically synthesized and characterized. It has been shown to be identical with the biological selenium donor SePX. Hydrolysis of selenophosphate is pH dependent and maximal at about pH 7. The dianion is the species which hydrolyzes fastest. The hydrolysis occurs via a dissociative monomeric metaphosphate-like transition state. Alcohols and amines are phosphorylated by monoselenophosphate. The sensitivity of detection of both 77Se and 125Te by NMR spectroscopy has been greatly increased by inverse proton detection using multiple-quantum 1H-{77Se} and 1H-{125Te} correlation spectroscopy. One- and two-dimensional HMQC spectra have been obtained for a variety of organoselenium and tellurium compounds. The signal enhancement obtained by such methods are comparable to the theoretical values.
Rapid X-Ray Declines and Plateaus in Swift GRB Light Curves Explained by a Highly Radiative Blast Wave

GRB X-ray light curves display rapid declines followed by a gradual steepening or plateau phase in 30% of GRBs in the Swift sample. Treating the standard relativistic blast wave model in a uniform circumburst medium, it is shown that if GRBs accelerate ultra-high-energy cosmic rays through a Fermi mechanism, then the hadronic component can be rapidly depleted by means of photopion processes on timescales ~102-104 s after the GRB explosion. While discharging the hadronic energy in the form of ultra-high-energy cosmic-ray neutrals and escaping cosmic-ray ions, the blast wave goes through a strongly radiative phase, causing the steep declines observed with Swift. Following the discharge, the blast wave recovers its adiabatic behavior, forming the observed plateaus or slow declines. These effects are illustrated by calculations of model bolometric light curves. The results show that steep X-ray declines and plateau features occur when GRB sources take place in rather dense media, with n 102 cm-3 out to 1017 cm.
Does the cost of capital differ across countries? An agency perspective*

In this keynote speech, I ask the question: Does the cost of capital differ for firms located in different countries? I argue that there are two ways to look at the cost of capital. First, there is the neoclassical perspective, which assumes that there are no agency problems. In integrated markets, the neoclassical cost of capital is the same in every country. Second, there is the agency perspective. Agency costs increase the cost of capital understood as the expected rate of return necessary for an investment to leave the value of the firm unaffected. Adjusting the cost of capital for agency costs, I argue that it differs across countries because of differences in corporate governance. I then provide a comparison of the agency-adjusted cost of capital between Japan and the US.
New physics models of direct CP violation in charm decays

In view of the recent LHCb measurement of ΔA CP, the difference between the time-integrated CP asymmetries in D → K + K − and D → π+π− decays, we perform a comparative study of the possible impact of New Physics degrees of freedom on the direct CP asymmetries in singly Cabibbo suppressed D meson decays. We systematically discuss scenarios with a minimal set of new degrees of freedom that have renormalizable couplings to the SM particles and that are heavy enough such that their effects on the D meson decays can be described by local operators. We take into account both constraints from low energy flavor observables, in particular D 0 − $ {\overline D^0} $ mixing, and from direct searches. While models that explain the large measured value for ΔA CP with chirally enhanced chromomagnetic penguins are least constrained, we identify a few viable models that contribute to the D meson decays at tree level or through loop induced QCD penguins. We emphasize that such models motivate direct searches at the LHC.
Input Force Reconstruction Using a Time Domain Technique

A time domain method is presented for estimating the discrete input forces acting on a structure based upon its measured response. The structure is essentially transformed into its own loads transducer. A set of inverse system Markov parameters, in which the roles of input and output are reversed, is estimated from forward system Markov parameters using a linear predictive scheme. Inputs and acceleration outputs are assumed to be collocated to maintain minimum phase. Subsequently, any set of measured operational sensor data of any time duration can be convolved with the inverse Markov parameters to produce estimates of the input forces. This problem is ill-posed, so a regularization technique is employed to stabilize computations. A stability analysis is performed to illustrate the effects of the regularization. Predicted pseudo-forces qualitatively approximate the actual input forces and, when applied back to the structure, produce accelerations which accurately match the measured operational sensor data.
What have we learned about chronic kidney disease-mineral bone disorder from the EVOLVE and PRIMO trials?

Purpose of Review The treatment of CKD-MBD (Chronic Kidney Disease-Mineral Bone Disorder) has traditionally focused on improvement in biochemical parameters of the disease. However, studies evaluating hard clinical end points or surrogate end points are limited.
Can a fluorous biphase solvent system improve a polymer immobilized heterogeneous hydrogenation catalyst

When diphosphine rhodium(I) hydrogenation catalysts are incorporated into organic polymers that contain a permanent pore structure, they can be utilized in fluorous biphase solvent systems, where reaction rates increase with the fluorous content of the solvent.
Jets and Parton Energy Loss at RHIC: Experimental Status

Experimental evidence from RHIC indicates that matter having an energy density far in excess of the value required for the creation of a deconfined phase is produced in ultrarelativistic Au+Au collisions at OsNN=200 GeV. This matter thermalizes rapidly, is strongly interacting, and displays hydrodynamic properties akin to a fluid with very low viscosity. Studies of the interaction of hard scattered partons with this matter provide an important probe of its properties. In fact, studies of the suppression of high-pT hadrons have been one of the key arguments used by the RHIC experiments that the matter created is something fundamentally new and exciting. I review the current experimental picture that has emerged from the data collected at RHIC, with an emphasis on the effort to extract quantitative measurements from the suppression of high-pT hadrons.
The pattern of correlated X-ray timing and spectral behavior in GRS 1915+105

From data obtained from the proportional counter array in the 2-11 keV and 11-30.5 keV energy ranges, GRS 1915+105 is seen during Rossi X-Ray Timing Explorer observations between 1996 May and October on two separate branches in a hardness-intensity diagram. On the hard branch, GRS 1915+105 exhibits narrow quasi-periodic oscillations (QPOs) ranging from 0.5 to 6 Hz with Δν/ν ~ 0.2. The QPOs are observed over intensities ranging from about 6000 to 20,000 counts s-1 in the 2-12.5 keV energy band, indicating a strong dependence on source intensity. Strong harmonics are seen, especially at lower frequencies. As the QPO frequency increases, the harmonic feature weakens and disappears. On the soft branch, narrow QPOs are absent and the low-frequency component of the power density spectrum is approximated by a power law, with index of about -1.25 for low count rates and -1.5 for high count rates (18,000 counts s-1). Occasionally, a broad, peaked feature in the 1-6 Hz frequency range is also observed on this branch. The source was probably in a very high state similar to those of other black hole candidates. Thermal-viscous instabilities in accretion disk models do not predict the correlation of the narrow QPO frequency and luminosity unless the fraction of luminosity from the disk decreases with the total luminosity.
Structure of Silicate Glasses and Melts at High Pressure: Quantum Chemical Calculations and Solid-State NMR

Despite their strong implications for magmatic processes in the earth's interior and pressure-induced structural changes in other amorphous, covalent oxide materials, little is known, beyond the coordination numbers of the framework cations, about the structures of silicate melts and glasses at high pressure. Here, we use multinuclear (27Al and 17O) solid-state NMR and quantum chemical calculations to study the structures of silicate glasses quenched from melts at pressures up to 10 GPa in a multianvil apparatus. The pressure-induced changes in atomic configurations in the silicate melts include the formation of highly coordinated framework units such as [5,6]Al and [5,6]Si and bridging oxygens linking these framework units and the presence of nonbridging oxygens coordinated by network-modifying cations and [5,6]Si. The proportion of high-pressure configurations such as [5,6]Al−O−[4]Si increases with pressure, but the fraction of nonbridging oxygen (Na−O−[4]Si) decreases with pressure, leading to an incre...
Berry–Esseen for Free Random Variables

An analogue of the Berry–Esseen inequality is proved for the speed of convergence of free additive convolutions of bounded probability measures. The obtained rate of convergence is of the order n−1/2, the same as in the classical case. An example with binomial measures shows that this estimate cannot be improved without imposing further restrictions on convolved measures.
THE REAPPEARANCE OF THE TRANSIENT LOW-MASS X-RAY BINARY X1658(298

In April 1999 the transient low-mass X-ray binary X1658-298 resumed its strong and persistent X-ray emission after a 21 yr interval of quiescence. We present RXTE data obtained soon after the reappearance, including four eclipses with a mean duration of 901.9 ± 0.8 s and ingress/egress times of 6-13 s. Our updated ephemeris for the source indicates that the 7.1 hr orbital period of the system is decreasing with a timescale of 107 yr. Contemporaneous optical observations provide the first ever light curve of V2134 Oph, the optical counterpart of X1658-298. The optical modulation is highly variable from night to night and exhibits a distinct, narrow eclipse feature of about 0.2 mag superposed on a gradual brightness variation with ~0.7-0.8 mag amplitude. Our data indicate that there is no significant offset between the time of mideclipse in the X-ray and optical and that the narrow optical eclipse feature is of the same duration as the X-ray eclipse. This implies an accretion disk structure characterized by enhanced optical emission coincident with the central X-ray-emitting area.
The Distribution of Stellar Mass in the Pleiades

As part of an effort to understand the origin of open clusters, we present a statistical analysis of the currently observed Pleiades. Starting with a photometric catalog of the cluster, we employ a maximum likelihood technique to determine the mass distribution of its members, including single stars and both components of binary systems. We find that the overall binary fraction for unresolved pairs is 68%. Extrapolating to include resolved systems, this fraction climbs to about 76%, significantly higher than the accepted field star result. Both figures are sensitive to the cluster age, for which we have used the currently favored value of 125 Myr. The primary and secondary masses within binaries are correlated, in the sense that their ratios are closer to unity than under the hypothesis of random pairing. We map out the spatial variation of the cluster's projected and three-dimensional mass and number densities. Finally, we revisit the issue of mass segregation in the Pleiades. We find unambiguous evidence of segregation, and introduce a new method for quantifying it.
Microlensing of Lensed Supernovae

Given the number of recently discovered galaxy-galaxy lens systems, we anticipate that a gravitationally lensed supernova will be observed within the next few years. We explore the possibility that stars in the lens galaxy will produce observable microlensing fluctuations in lensed supernova light curves. For typical parameters, we predict that ~70% of lensed SNe will show microlensing fluctuations of >0.5 mag, while ~25% will have fluctuations of >1 mag. Thus, microlensing of lensed supernova will be both ubiquitous and observable. In addition, we show that microlensing fluctuations will complicate measurements of time delays from multiply imaged supernovae: time delays accurate to better than a few days will be difficult to obtain. We also consider prospects for extracting the lens galaxy's stellar mass fraction and mass function from microlensing fluctuations via a new statistical measure, the time-weighted light-curve derivative.
When impediments make you jump rather than stumble: Regulatory nonfit, implementation intentions, and goal attainment

This paper examines the relative effectiveness of forming implementation intentions (i.e., making specific plans regarding how to go about achieving a goal) for increasing goal attainment under regulatory fit vs. nonfit. We discuss and empirically test the proposition that regulatory nonfit increases the effectiveness of implementation intentions. Extant research contrasts goals of differing difficulty (e.g., buying a textbook vs. finding an apartment) in order to test the relative effectiveness of implementation intentions. In contrast, the present study focuses on identifying the change in implementation intention effectiveness for the same goal (i.e., collecting and turning in receipts for a reward) under conditions of fit vs. nonfit. We empirically demonstrate that when faced with the same goal, people who experience regulatory nonfit perceive the task to be more difficult to complete than people who experience regulatory fit. In turn, when the task is perceived as being more difficult, implementation intentions prove more effective to enhance goal attainment. Our study provides insight into the interaction between regulatory fit and implementation intentions and subsequent effects on goal attainment.
Soliton excitations in polyacetylene

A theoretical analysis of the excitation spectrum of long-chain polyenes is presented. Because of the twofold degeneracy of the ground state of the dimerized chain, elementary excitations corresponding to topological solitons are obtained. The solitons can have three charge states $Q=0$. $\ifmmode\pm\else\textpm\fi{}e$. The neutral soliton has spin one-half while the charged solitons have spin zero. One electronic state is localized at the gap center for each soliton or antisoliton present. The soliton's energy of formation, length, mass, activation energy for motion, and electronic properties are calculated. These results are compared with experiment.
Strain Gradient Solution for the Eshelby-Type Polyhedral Inclusion Problem

Abstract The Eshelby-type problem of an arbitrary-shape polygonal inclusion embedded in an infinite homogeneous isotropic elastic material is analytically solved using a simplified strain gradient elasticity theory (SSGET) that contains one material length scale parameter. The Eshelby tensor for a plane strain inclusion with an arbitrary polygonal cross section is derived in a general form in terms of three potential functions, two of which have the same definitions as the ones involved in the counterpart Eshelby tensor based on classical elasticity. These potential functions, as area integrals over the polygonal cross section, are first converted to three line (contour) integrals using Green’s theorem, which are then evaluated analytically by direct integration. The newly derived Eshelby tensor is separated into a classical part and a gradient part. The former contains Poisson’s ratio only, while the latter includes the material length scale parameter additionally, thereby enabling the interpretation of the inclusion size effect. For homogenization applications, the area average of the new Eshelby tensor over the polygonal cross section is also provided in a general form. To illustrate the newly obtained Eshelby tensor and its area average, three types of polygonal inclusions are quantitatively studied by directly using the general formulas derived. The numerical results show that the components of the SSGET-based Eshelby tensor for all inclusion shapes considered vary with both the position and the inclusion size. It is also observed that the components of the averaged Eshelby tensor based on the SSGET change with the inclusion size. By applying the newly derived solution, a homogenization analysis of a composite reinforced by polygon-shaped fibers is performed. The induced strain in the composite is evaluated, and the effective stiffness of the composite is predicted. It is found that the values of the induced strain components approach from below those in a corresponding composite reinforced by circular fibers when the fiber size or the number of sides of the polygonal fiber increases. Also, the analysis reveals that the components of the effective stiffness tensor vary slightly with the fiber shape, and thus the simpler solution for the circular inclusion problem may be used to estimate the effective stiffness of a composite reinforced by regular polygon-shaped fibers.
Components and interfaces of a process management system for parallel programs

Parallel jobs are different from sequential jobs and require a different type of process management. We present here a process management system for parallel programs such as those written using MPI. A primary goal of the system, which we call MPD (for multipurpose daemon), is to be scalable. By this we mean that startup of interactive parallel jobs comprising thousands of processes is quick, that signals can be quickly delivered to processes, and that stdin, stdout, and stderr are managed intuitively. Our primary target is parallel machines made up of clusters of SMPs, but the system is also useful in more tightly integrated environments. We describe how MPD enables much faster startup and better runtime management of parallel jobs. We show how close control of stdio can support the easy implementation of a number of convenient system utilities, even a parallel debugger. We describe a simple but general interface that can be used to separate any process manager from a parallel library, which we use to keep MPD separate from MPICH.
Site-specific X-ray photoelectron spectroscopy using X-ray standing waves

We describe how X-ray photoelectron spectroscopy (XPS) measurements when conjoined with dynamical X-ray Bragg diffraction can determine site-specific electronic structure information. This result depends on the dipole approximation for the valence photo-excitation process in the low-energy X-ray limit that we validate through angle-integrated X-ray standing-wave (XSW) measurements of single-crystal Cu. We demonstrate the site-specific XPS technique for the single-crystal rutile TiO2 valence band and extract the individual Ti and O photoelectron partial density of states. First principles density functional calculations agree with our data after the angular-momentum-dependent photo-ionization cross-sections are properly accounted for.
Insider Ownership, Risk, and Leverage in REITs

We investigate the relative importance of managerial entrenchment and incentive alignment as indicated by REIT risk-taking. The two theories make contradictory predictions about the sign of the relation between insider ownership and risk. We test for the possibility of diminishing entrenchment returns to insider ownership. Empirical results for equity and asset betas soundly reject linear models in favor of nonmonotonic relations with reversals at insider ownership of 36%. Up to that point, increasingly entrenched insiders mitigate their own risk aversion. Above 36%, incentive alignment emerges as managers become more substantial owners. Leverage declines at an accelerating rate above 20% insider ownership. Together these results suggest a shift in the composition of risk, from leverage risk to asset risk, reflecting comparative advantage and a crossover in the relative monitoring costs of debt and equity. Problematically for linear models, the coefficient of insider ownership is not significant for most risk measures, producing the misleading appearance of no relation between insider ownership and risk. Institutional ownership is significantly negatively related to leverage. Thus incentives are aligned between insiders and institutional owners at insider ownership above 20%.
A Review of the Efficacy of Silicon Carbide Hot-Gas Filters in Coal Gasification and Pressurized Fluidized Bed Combustion Environments

Reviews of relevant literature and interviews with individuals cognizant of the state of the art in ceramic filters for hot-gas cleaning were conducted. Thermodynamic calculations of the stability of various ceramic phases were also made. Based on these calculations, reviews, and interviews, conclusions were reached regarding the use of silicon carbide-based ceramics as hot-gas filter media. Arguments are presented that provide the basis for our conclusion that high-purity silicon carbide is a viable material in the integrated coal gasification combined cycle (IGCC) and pressurized fluidized-bed combustion (PFBC) environments we examined. Clay-bonded materials are, we concluded, suspect for these applications, their extensive use notwithstanding. Operations data we reviewed focused primarily on clay-bonded filters, for which a great deal of experience exists. We used the clay-bonded filter experience as a point of reference for our review and analysis.
Intramolecular Dehydro-Diels–Alder Reaction Affords Selective Entry to Arylnaphthalene or Aryldihydronaphthalene Lignans

Intramolecular dehydro-Diels–Alder (DDA) reactions are performed affording arylnaphthalene or aryldihydronaphthalene lactones selectively as determined by choice of reaction solvent. This constitutes the first report of an entirely selective formation of arylnaphthalene lactones utilizing DDA reactions of styrene-ynes. The synthetic utility of the DDA reaction is demonstrated by the synthesis of taiwanin C, retrohelioxanthin, justicidin B, isojusticidin B, and their dihydronaphthalene derivatives. Computational methods for chemical shift assignment are presented that allow for regioisomeric lignans to be distinguished.
Chiral metal phosphate catalysis: highly asymmetric hetero-Diels–Alder reactions

We report a highly enantioselective hetero-Diels–Alder reaction of α-keto esters and isatins catalyzed by chiral calcium BINOL-derived phosphates. The structure of the catalyst is detailed by X-ray crystal structure analysis.
Twisted Whittaker Model and Factorizable Sheaves

Let G be a reductive group. The geometric Satake equivalence realized the category of representations of the Langlands dual group Ğ in terms of spherical perverse sheaves (or D-modules) on the affine Grassmannian GrG = G((t))/G[[t]] of the original group G. In the present paper we perform a first step in realizing the category of representations of the quantum group corresponding to Ğ in terms of the geometry of GrG. The idea of the construction belongs to Jacob Lurie.
The Impact of Military Forts on Agricultural Investments on the Great Plains in 1880

We empirically investigate the relationship between agricultural development and proximity to military forts in Kansas, Nebraska, and Colorado in 1880. Agricultural investments are substantially higher in counties where a military fort is present, suggesting that military forts stimulated agricultural development on the Great Plains. However, the reverse is not true; there is no statistical support for the notion that forts necessarily located in counties where substantial development was already occurring. Moreover, we found that while the presence of a military fort has the effect of increasing agricultural development, there is no evidence that such a presence sustained agricultural development.
Explicit subspace designs

A subspace design is a collection {H1, H2, ...,HM} of subspaces of $$\mathbb{F}_q^m$$ with the property that no low-dimensional subspace W of $$\mathbb{F}_q^m$$ intersects too many subspaces of the collection. Subspace designs were introduced by Guruswami and Xing (STOC 2013) who used them to give a randomized construction of optimal rate list-decodable codes over constant-sized large alphabets and sub-logarithmic (and even smaller) list size. Subspace designs are the only non-explicit part of their construction. In this paper, we give explicit constructions of subspace designs with parameters close to the probabilistic construction, and this implies the first deterministic polynomial time construction of list-decodable codes achieving the above parameters. Our constructions of subspace designs are natural and easily described, and are based on univariate polynomials over finite fields. Curiously, the constructions are very closely related to certain good list-decodable codes (folded RS codes and univariate multiplicity codes). The proof of the subspace design property uses the polynomial method (with multiplicities): Given a target low-dimensional subspace W, we construct a nonzero low-degree polynomial PW that has several roots for each Hi that non-trivially intersects W. The construction of PW is based on the classical Wronskian determinant and the folded Wronskian determinant, the latter being a recently studied notion that we make explicit in this paper. Our analysis reveals some new phenomena about the zeroes of univariate polynomials, namely that polynomials with many structured roots or many high multiplicity roots tend to be linearly independent.
STABILITY OF RELATIVISTIC FORCE-FREE JETS

We consider a two-parameter family of cylindrical force-free equilibria, modeled to match numerical simulations of relativistic force-free jets. We study the linear stability of these equilibria, assuming a rigid impenetrable wall at the outer cylindrical radius R{sub j}. Equilibria in which the Lorentz factor {gamma}(R) increases monotonically with increasing radius R are found to be stable. On the other hand, equilibria in which {gamma}(R) reaches a maximum value at an intermediate radius and then declines to a smaller value {gamma}{sub j} at R{sub j} are unstable. A feature of these unstable equilibria is that poloidal field line curvature plays a prominent role in maintaining transverse force balance. The most rapidly growing mode is an m = 1 kink instability which has a growth rate {approx}(0.4/{gamma} {sub j})(c/R{sub j}). The e-folding length of the equivalent convected instability is {approx}2.5{gamma} {sub j} R{sub j}. For a typical jet with an opening angle {theta}{sub j} {approx} few/{gamma}{sub j}, the mode amplitude grows only weakly with increasing distance from the base of the jet. The growth is much slower than one might expect from a naive application of the Kruskal-Shafranov stability criterion.
Index coding problem with side information repositories

To tackle the expected enormous increase in mobile video traffic in cellular networks, an architecture involving base station along with caching femto stations (referred to as helpers), storing popular files near users, has been proposed [1]. The primary benefit of caching is the enormous increase in downloading rate when a popular file is available at helpers near a user requesting that file. In this work, we explore a secondary benefit of caching in this architecture through the lens of index coding. We assume a system with n users and k caching helpers. Only helpers store files i.e., have side information. We investigate the following scenario: Each user requests for a distinct file that is not found in its set of neighboring helpers. Users are served coded packets (through an index code) by an omniscient base station. Every user decodes the desired packet from the coded packets and the side information from helpers nearby. We assume that users can obtain any file stored in their neighboring helpers without incurring transmission costs. With respect to the index code employed, we investigate an achievable scheme based on graph coloring (referred to as XOR coloring). We show that the general problem reduces to a canonical problem where every user is connected to exactly one helper. For the canonical problem, with constant number of helpers (k), we show that the complexity of computing the best XOR coloring scheme is polynomial in the number of users n. The result exploits a special complete bi-partite structure that the side information graphs exhibit for any finite k.