cssi/SciSciGPT-SciSciNet huggingface dataset:
Correlation decay and deterministic FPTAS for counting list-colorings of a graph

We propose a deterministic algorithm for approximately counting the number of list colorings of a graph. Under the assumption that the graph is triangle free, the size of every list is at least αΔ, where α is an arbitrary constant bigger than α = 2.8432 ..., the solution of αe-1/α = 2, and α is the maximum degree of the graph, we obtain the following results. For the case when the size of the each list is a large constant, we show the existence of a deterministic FPTAS for computing the total number of list colorings. The same deterministic algorithm has complexity 2O(log2n) without any assumptions on the sizes of the lists, where n is the size of the instance.Our results are not based on the most powerful existing counting technique - rapidly mixing Markov chain method. Rather we build upon concepts from statistical physics, in particular, the decay of correlation phenomena and its implication for the uniqueness of Gibbs measures in infinite graphs. This approach was proposed in two recent papers [BG06] and [Wei05]. The principle insight of the present work is that the correlation decay property can be established with respect to certain computation tree, as opposed to the conventional correlation decay property which is typically established with respect to graph theoretic neighborhoods of a given node. This allows truncation of computation at a logarithmic depth in order to obtain polynomial accuracy in polynomial time. While the analysis conducted in this paper is limited to the problem of counting list colorings, the proposed algorithm can be extended to an arbitrary constraint satisfaction problem in a straightforward way.
Life Is Not Easy: Mexico's Quest for Stability and Growth

In the wake of the debt crisis in 1982, Mexico adopted far reaching reforms but growth and stability remained elusive for many years. At present, the reforms and NAFTA seem to be finally paying off: inflation for 2000 is close to 10 percent and output per capita grew at an average of 5.4 percent during the last five years. However, altogether output per capita was only 9 percent higher in 1999 than in 1980, a great disappointment for particularly the 20 million Mexicans that live on less than $2 a day.
Unhiggsing the del Pezzo

We develop an unhiggsing procedure for finding the D-brane probe world volume gauge theory for blowups of geometries whose gauge theory data are known. As specific applications we unhiggs the well-studied theories for the cone over the third del Pezzo surface. We arrive at what we call pseudo del Pezzos and these will constitute a first step toward the understanding of higher, non toric del Pezzos. Moreover, our methods and results give further support for toric duality as well as obtaining superpotentials from global symmetry considerations.
Doppler Tomography of the Massive Compact Binary Stars in the Multiple Star Systems δ Orionis and HD 206267

Cross-correlation techniques were applied separately to 60 International Ultraviolet Exporer (IUE) ultraviolet spectra and 20 ground-based optical spectra of the massive close binary star in the triple system d Orionis A, producing the first double-lined spectroscopic orbital elements for this binary. The resulting masses are and 3 m sin i p 8.7 1.4 M 1 , . Existing photometric orbits and 3 m sin i p 4.4 0.3 M 2 , Hipparcos photometry limit the central binary’s orbital inclination to the range , resulting in spectroscopic 67 –77 masses of, at most, and (Harvin m p 11.2 M m p 5.6 M 1 , 2 , et al. 2002, ApJ, 565, 1216). These masses are shockingly low—about one-third of the masses that would be expected based on the nonrotating stellar models of Schaller (1992, A&AS, 96, 269), given the component MK types. These masses are also less than one-half of those predicted by the more recent rotating stellar models of Meynet & Maeder (2000, A&A, 361, 101). Subsequent cross-correlation analysis of the 36 IUE ultraviolet spectra of the massive close binary star in the triple system HD 206267 A found masses of 3 m sin i p 28.0 1 and (J. Harvin et al. 2004, 3 1.8 M m sin i p 15.3 1.5 M , 2 , in preparation) for that binary, in general agreement with both the masses expected from evolutionary models and the masses found by Burkholder et al. (1997, ApJ, 490, 328), based on optical spectra. Hipparcos detected photometric variations in HD 206267 A, but they could not be definitely classified as eclipses, constraining only the upper limit of HD 206267 A’s orbital inclination. In view of the magnitude of the mass discrepancy found, the components of the central binary in d Orionis A may turn out to be post-Roche Lobe overflow objects of the very early case A variety. In this scenario, repeated close passes by the tertiary star would have robbed the central binary of its orbital energy, bringing the components into Roche Lobe overflow and resulting in two stars that are overluminous for their masses by a factor of 10, but somewhat underluminous for their respective MK types. The ultraviolet spectra and the optical He i line prol6678 files of the components of d Orionis A and the ultraviolet spectra of the components of HD 206267 A were reconstructed using a version of the Doppler tomography algorithm from Bagnuolo et al. (1994, ApJ, 423, 446), based on the new radial velocity orbits described above. Analysis of the reconstructed spectra revealed the component stars’ spectral morphology, rotational velocities, and relative flux contributions.
Computer control of component insertion

IBM has successfully utilized computers to improve, monitor, and control actual production processes for many years and, as a result, has accumulated a large store of experience concerning their use as a manufacturing tool.
BOUNDARY LAYERS IN CATACLYSMIC VARIABLES: THE HEAO-1 X-RAY CONSTRAINTS

The predictions of the boundary layer model for the X-ray emission from novae are summarized. A discrepancy between observations and theory in the X-ray observations is found. Constraints on the nature of the boundary layers in novae, based on the lack of detections of novae in the HEAO-1 soft X-ray survey are provided. Temperature and column densities for optically thick boundary layers in novae are estimated.
Finite temperature SU(2) gauge theory: Critical coupling and universality class

The authors esaqmine SU(2) gauge theory in 3 + 1 dimensions at finite temperature in the vicinity of critical point. for various lattice sizes in time direction (N{sub T} = 1,2,4,8) they extract high precision values of the inverse critical coupling and critical values of the 4th order cumulant of Polyakov loops (Binder cumulant). They check the universality class of the theory by comparing the cumulant values to that of the 3D Ising model and find very good agreement. The Polyakov loop correlators for the indicated lattices are also measured and the string tension values extracted. The high precision values of critical coupling and string tension allow them to study the scaling of dimensionless T{sub c}/{radical}{sigma} ratio. The violation of scaling by < 10% is observed as the coupling is varied from weak to strong coupling regime.
An efficient system for user extendible languages

The recent survey by Feldman and Gries on Translator Writing Systems devotes space to discussion of "extendible" compilers but fails to explain fully the motivation. The reasons for an extendible high level language (and hence for an extendible compiler) are as follows.
Chemical stereodynamics: retrospect and prospect

Thematic aspects of chemical stereodynamics are discussed that offer much scope for further development. Particularly emphasized are opportunities to exploit angular correlations to recover information usually presumed to be inaccessible; means to hybridize rotational angular momentum and thereby create spatially oriented or aligned pendular states in which molecular axes are confined to oscillate about the direction of an external field; the major role of atomic electronegativity differences in producing steric preferences in reactivity, by affecting the location of nodes and asymmetric composition in molecular orbitals; and some newly recognized stereodynamic aspects of DNA replication.
Zimmerman's contentious conjectures: describing the present and prescribing the future of empirical management accounting research

We provide a discussion of three of Zimmerman's (2001) conjectures about, and prescriptions for improving, the current unsatisfactory state of empirical management accounting research: its focus on describing practice instead of testing theories; its focus on decision-making instead of control; and reliance on social sciences other than economics. We suggest that these conjectures are based on inaccurate descriptions of current empirical management accounting research and the prescriptions offer potentially misleading guidance for future research. In contrast to Zimmerman (2001), we believe that the current research is guided by theory from a variety of social sciences (primarily economics, psychology and sociology) and that this diversity is appropriate for the applied field of management accounting. We argue that while economics provides a good basis for much empirical research in management accounting, other social sciences offer more potential to explain important features of management accounting suc...
Film Cooling Effectiveness Distribution on a Gas Turbine Blade Platform With Inclined Slot Leakage and Discrete Film Hole Flows

A five-blade, linear cascade is used to experimentally investigate turbine blade platform cooling. A 30 deg inclined slot upstream of the blades is used to model the seal between the stator and rotor, and 12 discrete film holes are located on the downstream half of the platform for additional cooling. The film cooling effectiveness is measured on the platform using pressure sensitive paint (PSP). Using PSP, it is clear that the film cooling effectiveness on the blade platform is strongly influenced by the platform secondary flow through the passage. Increasing the slot injection rate weakens the secondary flow and provides more uniform film coverage. Increasing the freestream turbulence level was shown to Increase film cooling effectiveness on the endwall, as the increased turbulence also weakens the passage vortex. However downstream, near the discrete film cooling holes, the increased turbulence decreases the film cooling effectiveness. Finally, combining upstream slot flow with downstream discrete film holes should be cautiously done to ensure coolant is not wasted by overcooling regions on the platform.
Elastodynamic Response of Hollow Balls

An elastodynamic stress and deformation analysis for the hollow ball is given. A computer program for the stress analysis, though not part of the paper, is available upon request. Presented as an American Society of Lubrication Engineers paper at the ASLE/ASME Lubrication Conference held in Montreal, Canada, October 8–10, 1974
An effective compactness theorem for Coxeter groups

Through highly non-constructive methods, works by Bestvina, Culler, Feighn, Morgan, Rips, Shalen, and Thurston show that if a finitely presented group does not split over a virtually solvable subgroup, then the space of its discrete and faithful actions on \({\mathbb{H}^n}\) , modulo conjugation, is compact for all dimensions. Although this implies that the space of hyperbolic structures of such groups has finite diameter, the known methods do not give an explicit bound. We establish such a bound for Coxeter groups. We find that either the group splits over a virtually solvable subgroup or there is a constant C and a point in \({\mathbb{H}^n}\) that is moved no more than C by any generator. The constant C depends only on the number of generators of the group, and is independent of the relators.
Interpreting mean reversion in stock returns

Abstract This research attempts to distinguish between two competing economic explanations of mean reversion in stock returns: (1) mispricing in irrational markets versus and (2) predictable time variation in security risk premia. Excess portfolio returns are decomposed into “explained” and “unexplained” components using the CAPM. if one restricts the market risk premium to be constant over time, then mean reversion could be interpreted as a manifestation of mispricing in irrational markets. But changing the assumption about the time-series behavior of the market risk premium dramatically alters the test results. If one permits the conditional market risk premium to vary and to differ from the unconditional market risk premium, then mean reversion in stock returns is consistent with rational pricing in the framework of the CAPM. This suggests one need not abandon models based on rationality to explain this puzzling return behavior.
Power Aware Wireless File Downloading: A Constrained Restless Bandit Approach

This paper treats power-aware throughput maximization in a multi-user file downloading system. Each user can receive a new file only after its previous file is finished. The file state processes for each user act as coupled Markov chains that form a generalized restless bandit system. First, an optimal algorithm is derived for the case of one user. The algorithm maximizes throughput subject to an average power constraint. Next, the one-user algorithm is extended to a low complexity heuristic for the multi-user problem. The heuristic uses a simple online index policy and its effectiveness is shown via simulation. For simple 3-user cases where the optimal solution can be computed offline, the heuristic is shown to be near-optimal for a wide range of parameters.
A Lack of Resolved Near-Infrared Polarization Across the Face of M51

The galaxy M51 was observed using the Mimir instrument on the Perkins Telescope to constrain the resolved H-band (1.6 ?m) polarization across the galaxy. These observations place an upper limit of P H < 0.05% on the H-band polarization across the face of M51, at 0.6?arcsec pixel sampling. Even with smoothing to coarser angular resolutions, to reduce polarization uncertainty, the H-band polarization remains undetected. The polarization upper limit at H band, when combined with previous resolved optical polarimetry, rules out a Serkowski-like polarization dependence on wavelength. Other polarization mechanisms cannot account for the observed polarization ratio (P H/P VRI 0.05) across the face of M51.
Go for broke or play it safe? Dynamic competition with choice of variance

We consider a differential game in which the joint choices of the two players influence the variance, but not the mean, of the one-dimensional state variable. We show that a pure strategy perfect equilibrium in stationary Markov strategies (ME) exists and has the property that patient players choose to play it safe when sufficiently ahead and to take risks when sufficiently behind. We also provide a simple condition that implies both players choose risky strategies when neither one is too far ahead, a situation that ensures a dominant player emerges "quickly."
Classical Electrodynamic Equations of Motion with Radiative Reaction

The current status of classical description of radiating bodies is summarized and classical equations of motion are presented for the motion of charged bodies. The general physical solutions for the case of force as an explicit function of time and the exact solutions for many different force fields are given for relativistic, nonrelativistic, one-dimensional, and three- dimensional motion. It is concluded that these equations provide an exact classical description of a radiating body. (D.L.C.)
Far-Infrared Emission From E and E/S0 Galaxies

Early-type galaxies are filled with hot X-ray-emitting gas, but the study of the less plentiful cold gaseous component has been more challenging. Studies of cold material through IRAS 60 and 100 μm observations indicated that half of ordinary E and E/S0 galaxies were detected above the 3 σ level, indicating that cold gas is common, although no correlation was found between the optical and far-infrared fluxes. Most detections were near the instrumental threshold, and given an improved understanding of detection confidence, we reconsider the 60 and 100 μm detection rate. After excluding active galactic nuclei, peculiar systems, and background contamination, only 15 nonpeculiar E and E/S0 galaxies from the RSA catalog are detected above the 98% confidence level, about 12% of the sample. An unusually high percentage of these 15 galaxies possess cold gas (H I CO) and optical emission lines (Hα), supporting the presence of gas cooler than 104 K. The 60-100 μm flux ratios imply a median dust temperature for the sample of 30 K, with a range of 23-28 K. These detections define the upper envelope of the optical to far-infrared relationship, F${r fir}$ -->F$0.24{±}0.08B$ -->, showing that optically bright objects are also brighter in the infrared, although with considerable dispersion. A luminosity correlation is present wth L${r fir}$ -->L$1.65{±}0.28B$ -->, but the dust temperature is uncorrelated with luminosity. The dust masses inferred from the far-infrared measurements are 1 order of magnitude greater than those from extinction observations, except for the recent merger candidate NGC 4125, where they are equal. We suggest that the ratio of the far-infrared dust mass to the extinction dust mass may be an indicator of the time since the last spiral-spiral merger. These results are compared to the model in which most of the dust comes from stellar mass loss and the heating is primarily by stellar photons. Models that contain large dust grains composed of amorphous carbon plus silicates come close to reproducing the typical 60-100 μm flux ratios, the far-infrared luminosity, and the Lfir-LB relationship.
Aging-related expression of inducible nitric oxide synthase and markers of tissue damage in the rat penis

Aging-related expression of inducible nitric oxide synthase and markers of tissue damage in the rat penis
On stochastic gradient and subgradient methods with adaptive steplength sequences

Traditionally, stochastic approximation (SA) schemes have been popular choices for solving stochastic optimization problems. However, the performance of standard SA implementations can vary significantly based on the choice of the steplength sequence, and in general, little guidance is provided about good choices. Motivated by this gap, we present two adaptive steplength schemes for strongly convex differentiable stochastic optimization problems, equipped with convergence theory, that aim to overcome some of the reliance on user-specific parameters. The first scheme, referred to as a recursive steplength stochastic approximation (RSA) scheme, optimizes the error bounds to derive a rule that expresses the steplength at a given iteration as a simple function of the steplength at the previous iteration and certain problem parameters. The second scheme, termed as a cascading steplength stochastic approximation (CSA) scheme, maintains the steplength sequence as a piecewise-constant decreasing function with the reduction in the steplength occurring when a suitable error threshold is met. Then, we allow for nondifferentiable objectives but with bounded subgradients over a certain domain. In such a regime, we propose a local smoothing technique, based on random local perturbations of the objective function, that leads to a differentiable approximation of the function. Assuming a uniform distribution on the local randomness, we establish a Lipschitzian property for the gradient of the approximation and prove that the obtained Lipschitz bound grows at a modest rate with problem size. This facilitates the development of an adaptive steplength stochastic approximation framework, which now requires sampling in the product space of the original measure and the artificially introduced distribution.
New coating materials for IR laser optical components

Abstract Concepts of reactive atmosphere processing are applied to the preparation, purification, and thermal characterization of three rare-earth fluorides (LaF3, CeF3, and PrF3) and BiF3, BiI3, and KGaF4. The rare-earth fluorides have optical absorption coefficients between 0.6 and 0.9 cm−1 at 9.27 μm; of the rare-earth fluorides, only LaF3 is a good coating material at 3.8 μm. BiF3 and KGaF4 appear to have low absorption at 9.27 μm and 3.8 μm. BiI3 shows a flat response between 2.5 and 20 μm.
Time resolved reflectivity measurements in Pb-implanted SrTiO3

Time resolved optical reflectivity (TRR) is a simple and elegant technique for dynamically monitoring the interface motion that occurs during crystallization of thin films and amorphous layers on crystalline substrates. This in situ technique has enabled measurements of the solid-phase epitaxial regrowth rate of amorphous silicon layers produced by ion implantation to be extended by over five orders of magnitude to rates in excess of 10/sup 6/ /angstrom//s. TRR is also well suited to measurements of crystallization kinetics in ion-implanted ceramic oxides. In the present work, the technique is used to directly monitor the regrowth during thermal annealing of amorphous layers produced by ion implantation in the crystalline ceramic oxide SrTiO/sub 3/. In particular, the effect of ambient water vapour on the epitaxial regrowth rate of amorphous layers in these materials has been examined. This study provides new insight into the role of water in regrowth of materials of this nature and clearly illustrates the utility of TRR in measurements of crystallization rates in ceramic oxides. 11 refs., 5 figs.
Milliwatt power AlGaN quantum well deep ultraviolet light emitting diodes

We report on the development of deep ultraviolet AlGaN multiple quantum well light emitting diodes on sapphire with peak emission wavelength from 278 nm to 340 nm. The high quality of the n+-AlGaN buffer layer was achieved using a new pulsed atomic layer epitaxy growth technique to deposit a high quality AlN buffer layers followed by a strain relief AlN/AlGaN superlattice. These devices exhibited pulsed powers as high as 3 mW, 10 mW and 13 mW for 1 A of pumping current. Under pulsed pumping, the external quantum efficiencies of about 0.1% (278 nm), 0.45% (325 nm) and 0.55% (340 nm) represent record high values and the shortest LED emission wavelengths to date. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Global Regularity for the Viscous Boussinesq Equations

The global regularity for the viscous Boussinesq equations is proved. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of 1,2-Benzisoxazole 2-Oxides

Abstract A series of 2-hydroxyaryl ketoximes were converted to the corresponding 1,2-benzisoxazole 2-oxides by treatment with iodobenzene diacetate (in acetic acid or methanol) or N-chlorosuccinimide in water. Both methods gave moderate to excellent yields for a variety of substituted oximes under mild conditions within short reaction times. The latter method has the advantages of an aqueous solvent and lack of halogenated organic by-products.
A concise synthesis of highly substituted imidazoles via copper-mediated oxidative C–H functionalization

We herein report a simple and concise route for the synthesis of highly substituted imidazole derivatives via copper-mediated oxidative C–H functionalization in good to high yields. The advantage of the reaction lies in its mild reaction conditions and readily available starting materials.
Group descent algorithms for nonconvex penalized linear and logistic regression models with grouped predictors

Penalized regression is an attractive framework for variable selection problems. Often, variables possess a grouping structure, and the relevant selection problem is that of selecting groups, not individual variables. The group lasso has been proposed as a way of extending the ideas of the lasso to the problem of group selection. Nonconvex penalties such as SCAD and MCP have been proposed and shown to have several advantages over the lasso; these penalties may also be extended to the group selection problem, giving rise to group SCAD and group MCP methods. Here, we describe algorithms for fitting these models stably and efficiently. In addition, we present simulation results and real data examples comparing and contrasting the statistical properties of these methods.
Met expression is associated with poor outcome in patients with axillary lymph node negative breast carcinoma

BACKGROUND Activation of Met, the receptor for scatter factor/hepatocyte growth factor, is associated with mitogenesis, motogenesis, and decreased cell adhesion. Elevated expression of Met has been shown in advanced cases of carcinoma of the prostate, stomach, pancreas, and thyroid. The authors previously demonstrated that Met expression is an independent prognostic marker associated with decreased survival in patients with breast carcinoma. METHODS Expression of Met in 113 archival breast carcinoma specimens from patients with axillary lymph node negative invasive ductal carcinoma was evaluated using a standard immunoperoxidase technique. Cases were scored by two pathologists using an H-score algorithm and then analyzed for correlation with known prognostic factors and survival. RESULTS Expression of Met showed a bimodal distribution with 25% of cases showing high levels of expression. In contrast to previous studies, the results of the current study showed a significant association between Met expression and nuclear and histologic grade. The 5-year survival rate for Met negative patients with tumors with low Met expression was 95% in this cohort, compared with 80% for patients with tumors showing high Met expression. Patients whose tumors had a high level of Met expression were found to have a 5-year relative risk (RR) of dying of metastatic disease of 5.05 (P = 0.03) independent of patient age and tumor size. Combined analysis of Met and nuclear grade resulted in a marked increase in independent predictive value (RR = 33.4; P < 0.01). CONCLUSIONS The results of the current study found that high levels of Met expression were associated with death due to metastatic disease in patients with axillary lymph node negative breast carcinoma. Expression of Met may be a useful prognostic indicator of more aggressive disease in patients whose prognosis is not easily stratified by current histopathologic markers. Cancer 1999;86:2259–65. © 1999 American Cancer Society.
Selective area growth of GaN on SiC substrate by ammonia-source MBE

The feasibility of selective area growth of GaN by ammonia-MBE has been demonstrated on SiC substrates. Under typical growth conditions for ammonia-MBE, GaN was unable to nucleate on the bare SiC surface. However, GaN nucleation could occur instantly if the SiC surface was first seeded with a thin (300 A) AlN layer prepared by magnetron sputter epitaxy. Thus, GaN growth could occur selectively from a patterned, pre-deposited thin AlN seed layer, and effectively utilizing the exposed SiC surface as a pseudo mask. Evidence of lateral overgrowth was observed by scanning electron microscopy and X-ray diffraction studies. The selectively grown GaN patterns exhibited a strong tendency to form {1011} or {1012} type of facets with excellent smoothness.
Preparation and evaluation of 1,3-diaminocyclopentane-linked dihydropyrimidinone derivatives as selective α1a-receptor antagonists

Abstract Several 1,3-diaminocyclopentane linked α 1a -receptor antagonists were prepared using a divergent chemical strategy that allows for rapid analysis of all stereochemical permutations for their effect on α 1 -receptor binding.
Kinetic density functional theory of freezing

A theory of freezing of a dense hard sphere gas is presented. Starting from a revised Enskog theory, hydrodynamic equations that account for non-local variations in the density but local variations in the flow field are derived using a modified Chapman Enskog procedure. These hydrodynamic equations, which retain structural correlations, are shown to be effectively a time dependent density functional theory. The ability of this theory to capture the solid liquid phase transition is established through analysis and numerical simulations.
The space of complete quotients

We introduce complete quotients over the projective line and prove that they form smooth projective varieties. The resulting parameter spaces coincide with the varieties constructed in [HLS11] and [Shao11]. Hence they provide modular smooth compactifications with normal crossing boundaries of the spaces of algebraic maps from the projective line to Grassmannian varieties.
Heavy quark production

We provide a brief overview of some current experimental and theoretical issues of heavy quark production.
On the heterogeneity of dowry motives

Dowries have been modeled as pre-mortem bequests to daughters or as groom-prices paid to in-laws. These two classes of models yield mutually exclusive predictions, but empirical tests of these predictions have been mixed. We draw from historical evidence that suggests a bifurcated marriage market, in which some households use dowries as a bequest and others use dowries as a price. The competing theories of dowry allow us to structure an exogenous switching regression that places households in the price or bequest regime. The empirical strategy allows for multiple checks on the validity of regime assignment. Using retrospective marriage data from rural Bangladesh, we find evidence of heterogeneity in dowry motives; that bequest dowries have declined in prevalence and amount over time; and that bequest households are better off compared to price households on a variety of welfare measures.
Model-mediated Telemanipulation

This paper presents a user-centered, model-mediated approach to bilateral telemanipulation under large communication delays. Assuming that the environment is only slowly or infrequently changing, it mitigates user perception difficulties and allows stable motion and force interactions with the remote environment. Rather than directly sending slave sensory data to the user, the method abstracts the data to form a very simple model of the environment. The model is transmitted to the master, where it is haptically rendered for user feedback without any lag. In return, the slave only executes force or motion commands consistent with the model. This effectively mediates the master—slave interaction. Particular attention is placed on the system behavior as it adjusts to unexpected environment interactions and as the model updates. The basic principles of the approach are demonstrated on a simple one degree-of-freedom telerobotic system operating with four seconds of round-trip delay.
The Ehrhart Polynomial of the Birkhoff Polytope

The nth Birkhoff polytope is the set of all doubly stochastic n × n matrices, that is, those matrices with nonnegative real coefficients in which every row and column sums to one. A wide open problem concerns the volumes of these polytopes, which have been known for n $\leq$ 8. We present a new, complex-analytic way to compute the Ehrhart polynomial of the Birkhoff polytope, that is, the function counting the integer points in the dilated polytope. One reason to be interested in this counting function is that the leading term of the Ehrhart polynomial is—up to a trivial factor—the volume of the polytope. We implemented our methods in the form of a computer program, which yielded the Ehrhart polynomial (and hence the volume) of the ninth Birkhoff polytope, as well as the volume of the tenth Birkhoff polytope.
Supersymmetric hybrid inflation redux

Abstract We discuss the important role played during inflation by one of the soft supersymmetry breaking terms in the inflationary potential of supersymmetric hybrid inflation models. With minimal Kahler potential, the inclusion of this term allows the prediction for the scalar spectral index to agree with the value n s = 0.963 − 0.015 + 0.014 found by WMAP5. In the absence of this soft term, and by taking into account only radiative and supergravity corrections, it is well known that n s ⩾ 0.985 . This same soft term has previously been shown to play a key role in resolving the MSSM μ problem. The tensor to scalar ratio r is quite small in these models, taking on values r ⩽ 10 − 5 in the WMAP5 2σ range of n s .
The effect of ciprofloxacin on tendon, paratenon, and capsular fibroblast metabolism

The pathologic mechanisms underlying fluoroquinolone-induced tendinopathy are poorly understood. The observed incidence of tendinitis and tendon rupture in patients treated with ciprofloxacin hydrochloride suggests that the fluoroquinolone antibiotics alter tendon fibroblast metabolism. The purpose of this study was to examine the effect of ciprofloxacin on fibroblast metabolism in vitro. Canine Achilles tendon, paratenon, and shoulder capsule specimens were maintained in culture with ciprofloxacin (5, 10, or 50 microg/ml). Fibroblast proliferation, collagen synthesis, proteoglycan synthesis, and matrix-degrading activity were analyzed. Incubation of Achilles tendon, Achilles paratenon, and shoulder capsule fibroblasts with ciprofloxacin resulted in a statistically significant 66% to 68% decrease in cell proliferation compared with control cells at day 3 in culture. Ciprofloxacin caused a statistically significant 36% to 48% decrease in collagen synthesis compared with controls in all fibroblast cultures. Ciprofloxacin caused a statistically significant 14% to 60% decrease in proteoglycan synthesis in all fibroblast cell lines. Compared with unstimulated control fibroblasts, culture media from Achilles tendon, paratenon, and shoulder capsule cells that were exposed to ciprofloxacin demonstrated statistically significant increases in matrix-degrading proteolytic activity after 72 hours in culture. This study demonstrates that ciprofloxacin stimulates matrix-degrading protease activity from fibroblasts and that it exerts an inhibitory effect on fibroblast metabolism. The increase in protease activity and the inhibition of both cell proliferation and the synthesis of matrix ground substance may contribute to the clinically described tendinopathies associated with ciprofloxacin therapy.
Detecting and resolving policy misconfigurations in access-control systems

Access-control policy misconfigurations that cause requests to be erroneously denied can result in wasted time, user frustration, and, in the context of particular applications (e.g., health care), very severe consequences. In this article we apply association rule mining to the history of accesses to predict changes to access-control policies that are likely to be consistent with users' intentions, so that these changes can be instituted in advance of misconfigurations interfering with legitimate accesses. Instituting these changes requires the consent of the appropriate administrator, of course, and so a primary contribution of our work is how to automatically determine from whom to seek consent and how to minimize the costs of doing so. We show using data from a deployed access-control system that our methods can reduce the number of accesses that would have incurred costly time-of-access delays by 43p, and can correctly predict 58p of the intended policy. These gains are achieved without impacting the total amount of time users spend interacting with the system.
On gravitational description of Wilson lines

We study solutions of Type IIB supergravity, which describe the geometries dual to supersymmetric Wilson lines in = 4 super-Yang-Mills. We show that the solutions are uniquely specified by one function which satisfies a Laplace equation in two dimensions. We show that if this function obeys a certain Dirichlet boundary condition, the corresponding geometry is regular, and we find a simple interpretation of this boundary condition in terms of D3 and D5 branes which are dissolved in the geometry. While all our metrics have AdS5 × S5 asymptotics, they generically have nontrivial topologies, which can be uniquely specified by a set of non-contractible three- and five-spheres.
Constant Price of Anarchy in Network-Creation Games via Public-Service Advertising

Network creation games have been studied in many different settings recently. These games are motivated by social networks in which selfish agents want to construct a connection graph among themselves. Each node wants to minimize its average or maximum distance to the others, without paying much to construct the network. Many generalizations have been considered, including non-uniform interests between nodes, general graphs of allowable edges, bounded budget agents, etc. In all of these settings, there is no known constant bound on the price of anarchy. In fact, in many cases, the price of anarchy can be very large, namely, a constant power of the number of agents. This means that we have no control on the behavior of network when agents act selfishly. On the other hand, the price of stability in all these models is constant, which means that there is chance that agents act selfishly and we end up with a reasonable social cost.
P(PhCH2NCH2CH2)3N: An Efficient Lewis Base Catalyst for the Synthesis of Propargylic Alcohols and Morita−Baylis−Hillman Adducts via Aldehyde Alkynylation

Proazaphosphatrane P(PhCH2NCH2CH2)3N (1a) is an efficient catalyst for the addition of aryl trimethylsilyl alkynes to a variety of aromatic, aliphatic, and heterocyclic aldehydes in THF at room temperature. The reaction conditions are mild and employ a low catalyst loading (ca. 5 mol %). Only propargylic alcohols were isolated in good to excellent isolated yields when electron-rich, electron-neutral, heterocyclic, and aliphatic aldehydes were employed, whereas β-branched Morita−Baylis−Hillman (MBH) type adducts were isolated with electron-deficient aromatic aldehydes after conventional acid hydrolysis of the TMS ether products. Alkynes containing heterocyclic and aromatic groups bearing electron-withdrawing or -donating substituents underwent clean addition to cyclohexanecarboxaldehyde and to electron-rich aromatic aldehydes to give propargylic alcohols in excellent isolated yields. β-Branched Morita−Baylis−Hillman (MBH) type adducts were isolated when electron-deficient aromatic aldehydes were employed. ...
Materials technology applied to nuclear accelerator targets

Modification of the crystal structure of physical vapor deposited (PVD) thin films and foils by the introduction of various lamellar constituents makes possible the production of very strong, stress free, metallurgical structures. Foils
WAVELENGTHS OF THE 3p-3d TRANSITIONS OF THE Co- AND Fe-LIKE IONS : THE EFFECTS OF ELECTRON CORRELATION

The experimental observations of the 3p/sup 6/ 3d/sup 9/ /sup 2/D - 3p/sup 5/ 3d/sup 10/ /sup 2/p transitions of the Co-like ions and 3p/sup 6/ 3d/sup 8/ /sup 3/F/sub 4/ - 3p/sup 5/ 3d/sup 9/ /sup 3/F/sub 3/ of the Fe-like ions have recently been extended to highly charged ions of heavy elements up to uranium (Z = 92). A comparison between the observed energies and calculated values from the Dirac-Fock model indicated persistent discrepancies of 3 to 4 eV for all ions. Systematic multiconfiguration Dirac-Fock calculations for these transitions have been carried out with emphases on the effects of electron correlation. The previously found discrepancies theory and experiment have mostly removed after the inclusion of the electron-electron correlation effects in the theoretical calculations. 13 refs.
On sparse oracles separating feasible complexity classes

This note clarifies which oracles separate NP from P and which do not. In essence, we are changing our research paradigm from the study of which problems can be relativized in two conflicting ways to the study and characterization of the class of oracles achieving a specified relativization. Results of this type have the potential to yield deeper insights into the nature of relativization problems and focus our attention on new and interesting classes of languages.
Feasibility study of minor actinide transmutation in light-water reactors with various AM/CM separation efficiencies

Abstract A study was conducted to evaluate the feasibility of minor actinide (MA) transmutation in light water reactors (LWR). The purpose of this work was to provide a guide for future investigations into MA transmutation in LWR. This work considered the effects of various Am/Cm separation efficiencies as well as homogeneous and heterogeneous MA bearing fuel assemblies. The MA content was introduced into the reactor as mixed oxide plus minor actinide (MOX + MA) fuel. Three Am/Cm separation efficiencies were independently considered: 99.9%, 99.0%, and 90.0%. In order to evaluate the feasibility of MA transmutation, the fuel performance of the various assemblies and core designs, as well as their respective safety related parameters, were calculated. The reduction of the burden of high level waste (HLW) motivated the investigation of MA transmutation. It was found that the MA bearing fuel assemblies and their subsequent core designs were able to perform within the safety limits required as well as achieving similar burnups to a UO 2 core. The Am transmutation rates were ∼40% for the homogeneous assemblies and up to 68% for the MA targets in the heterogeneous assemblies after the described burnup, however, there was a significant amount of Cm produced during burnup. This Cm production was due to the more favorable neutron capture reaction over fission for Am in the thermal spectrum. Future work should examine the benefits of Am transmutation at the expense of large Cm production rates.
Lateral Motion of Free Rolling Tail Rockets in Free Flight

A study of the dynamics of free-rolling tail configurations is presented. The linearized theory of symmetric missiles motion is extended to free-rolling tail configurations to define a dynamically equivalent fixed-tail rocket. The asymmetries effect is introduced by small forcing functions at body and tail roll rate frequencies. Finally, Magnus effects and conditions at resonance and resonance lock-in are discussed.
Nonlinear Inverse Bremsstrahlung and Heated-Electron Distributions

When $\frac{Z{{v}_{0}}^{2}}{{{v}_{e}}^{2}}\ensuremath{\gtrsim}1$, inverse bremsstrahlung results in a non-Maxwellian velocity distribution for which the absorption is reduced by up to a factor of 2 compared with the Maxwellian distribution usually assumed. Transport and atomic processes are also altered. Especially in materials with $Z\ensuremath{\gg}1$, this is significant at lower intensities than for the well-known nonlinearity for which the measure is $\frac{{{v}_{0}}^{2}}{{{v}_{e}}^{2}}$.
Experimental status of exotic mesons and the GlueX experiment

One of the unanswered and most fundamental questions in physics regards the nature of the confinement mechanism of quarks and gluons in QCD. Exotic hybrid mesons manifest gluonic degrees of freedom and their spectroscopy will provide the data necessary to test assumptions in lattice QCD and the specific phenomenology leading to confinement. Within the past two decades a number of experiments have put forth tantalizing evidence for the existence of exotic hybrid mesons in the mass range below 2 GeV. This talk represents an overview of the available data and what has been learned. In looking toward the future, the GlueX experiment at Jefferson Laboratory represents a new initiative that will perform detailed spectroscopy of the light-quark meson spectrum. This experiment and its capabilities will be reviewed.
A Unique Route to Tetrasubstituted Propargylic Amines by Catalytic Markovnikov Hydroamination–Alkynylation

The method allows the direct access to the title compounds from an amine and alkynes via an unusual route involving no carbonyl compounds.
The Effect of Exchange Rate Volatility on Trade in Durables

Because durable goods have the quality of an asset, risk-averse consumers wan to pay a lower price for durable than for nondurable goods so that they are compensated for the risk of price changes; they require risk premium. Since the exchange rate is a strong source of uncertainty in import prices, exchange rate volatility has a negative effect on the demand for imported durables. In an imperfectly competitive market, the volatility of the exchange rate is predicted to reduce the relative price of imported durables. The prediction is supported by an empirical investigation of US imports.
Is It Worth Looking? Abdominal Imaging After Pancreatic Cancer Resection: a National Study

Abdominal imaging is often performed after pancreatic cancer resection. We attempted to quantify the volume and estimate the cost of complex imaging after pancreatectomy nationwide, and to determine whether their frequent use confers benefit. Patients with pancreatic adenocarcinoma who underwent resection were identified in Surveillance, Epidemiology and End Results–Medicare (1991–2005). Claims for abdominal imaging ≤5 years after resection were analyzed. Patients receiving annual CT scans were identified. Univariate and multivariate analyses were performed. To assess frequency of annual CT scanning in patients with superior survival, the top decile was further analyzed. Eleven thousand eight hundred fifty studies were performed on 2,217 patients. Ten thousand five hundred forty-two (89%) were CT scans. The median number of scans doubled from three in 1991 to six in 2005 (p < 0.0001). Among patients with sufficient survival to allow for analysis, 51.3% received annual CT scans, while only 32.4% of top-performing patients received annual scans. Univariate analysis of the 10% of patients with superior survival did not reveal any significant benefit associated with annual imaging. Utilization of complex imaging after pancreatic cancer resection has increased substantially among Medicare beneficiaries, driven primarily by an increasing number of CT scans. Our study demonstrated no significant survival benefit among patients who received scans on a routine basis.
A Methodology for Object Identification and Tracking in Construction Based on Spatial Modeling and Image Matching Techniques

: Understanding the motion characteristics of on-site objects is desirable for the analysis of construction work zones, especially in problems related to safety and productivity studies. This article presents a methodology for rapid object identification and tracking. The proposed methodology contains algorithms for spatial modeling and image matching. A high-frame-rate range sensor was utilized for spatial data acquisition. The experimental results indicated that an occupancy grid spatial modeling algorithm could quickly build a suitable work zone model from the acquired data. The results also showed that an image matching algorithm is able to find the most similar object from a model database and from spatial models obtained from previous scans. It is then possible to use the matched information to successfully identify and track objects.
Experiments with program locality

For many years, there has been interest in "program locality" as a phenomenon to be considered in storage allocation. This notion arises from the empirical observation that it is possible to run a program efficiently with only some fraction of its total instruction and data code in main storage at any given time. That virtual memory systems can be made to run at all demonstrates that program locality can be used to advantage; and though it is certainly possible to write a program which violates the principles of locality, it seems one must go out of one's way to do so.
Complex Chern-Simons from M5-branes on the squashed three-sphere

We derive an equivalence between the (2,0) superconformal M5-brane field theory dimensionally reduced on a squashed three-sphere, and Chern-Simons theory with complex gauge group. In the reduction, the massless fermions obtain an action which is second order in derivatives and are reinterpreted as ghosts for gauge fixing the emergent non-compact gauge symmetry. A squashing parameter in the geometry controls the imaginary part of the complex Chern-Simons level.