cssi/SciSciGPT-SciSciNet huggingface dataset:
Detection of X-ray emission from the remnant of the supernova 1006 A.D.

Observations from OSO-7 identify SN 1006 as a weak X-ray source, with an intensity of 9 x 10/sup -11/ ergs cm/sup -2/ s/sup -1/ in the energy range 1--10 keV. The spectrum can be represented by a power law with energy index 1.3 or by thermal bremsstrahlung at kT = 4 keV. Interpretation of the observations as thermal X-ray emission from an adiabatic blast wave indicates that SN 1006 is about 1.2 kpc distant, and that its initial kinetic energy is of the order of 10/sup 50/ ergs. (auth)
Elastically Effective Strand Density in Polymer Networks

Abstract A new expression is derived which relates the density of elastically effective strands in a polymer network to the densities of random cross-links, main-chain scissions, and entanglements and to the molecular weight distribution of the initial linear polymer. Methods are recommended for characterizing the cross-link and scission densities from measurable sol fractions and for determining the entanglement density empirically. The strand density can be evaluated quite easily for the random and uniform initial molecular weight distributions. The new expression differs appreciably from that of Mullins and Bueche, owing principally to a new criterion for effectively trapping network entanglements. The statistical approach used to derive the strand density is also used in a new derivation of an existing implicit expression for the gel fraction.
The independent set sequence of regular bipartite graphs

Abstract Let i t ( G ) be the number of independent sets of size t in a graph G . Alavi, Erdős, Malde and Schwenk made the conjecture that if G is a tree then the independent set sequence { i t ( G ) } t ≥ 0 of G is unimodal; Levit and Mandrescu further conjectured that this should hold for all bipartite G . We consider the independent set sequence of finite regular bipartite graphs, and graphs obtained from these by percolation (independent deletion of edges). Using bounds on the independent set polynomial P ( G , λ ) ≔ ∑ t ≥ 0 i t ( G ) λ t for these graphs, we obtain partial unimodality results in these cases. We then focus on the discrete hypercube Q d , the graph on vertex set { 0 , 1 } d with two strings adjacent if they differ on exactly one coordinate. We obtain asymptotically tight estimates for i t ( d ) ( Q d ) in the range t ( d ) / 2 d − 1 > 1 − 1 / 2 , and nearly matching upper and lower bounds otherwise. We use these estimates to obtain a stronger partial unimodality result for the independent set sequence of Q d .
Approximation by Analytic Matrix Functions: The Four Block Problem

Abstract The four block problem is a generalization of Nehari's problem for matrix functions. It plays an important role in H ∞ -optimal control theory. It is well known that Nehari's problem for a continuous scalar function has a unique solution. However, in the matrix case the situation is quite different. V. V. Peller and N. J. Young (1994, J. Funct. Anal. 120 , 300–343) studied superoptimal solutions of Nehari's problem. They minimize not only the L ∞ -norm of the corresponding matrix function but also the essential suprema of all further singular values. It was shown that for H ∞ + C matrix functions Nehari's problem has a unique superoptimal solution. In this paper we study superoptimal solutions of the four block problem and we find a natural condition under which such a superoptimal solution is unique. Our result is new even in the case of Nehari's problem. We study some related problems such as thematic factorizations, invariance of indices, and inequalities between the singular values of the four block operator and the superoptimal singular values.
The morality of software piracy: a cross-cultural analysis

Software piracy is a damaging and important moral issue, which is widely believed to be unchecked in particular areas of the globe. This cross-cultural study examines differences in morality and behavior toward software piracy in Singapore versus the United States, and reviews the cultural histories of Asia versus the United States to explore why these differences occur. The paper is based upon pilot data collected in the U.S. and Singapore, using a tradeoff analysis methodology and analysis. The data reveal some fascinating interactions between the level of ethical transgression and the rewards or consequences which they produce.
Efficient touch based localization through submodularity

Many robotic systems deal with uncertainty by performing a sequence of information gathering actions. In this work, we focus on the problem of efficiently constructing such a sequence by drawing an explicit connection to submodularity. Ideally, we would like a method that finds the optimal sequence, taking the minimum amount of time while providing sufficient information. Finding this sequence, however, is generally intractable. As a result, many well-established methods select actions greedily. Surprisingly, this often performs well. Our work first explains this high performance - we note a commonly used metric, reduction of Shannon entropy, is submodular under certain assumptions, rendering the greedy solution comparable to the optimal plan in the offline setting. However, reacting online to observations can increase performance. Recently developed notions of adaptive submodularity provide guarantees for a greedy algorithm in this online setting. In this work, we develop new methods based on adaptive submodularity for selecting a sequence of information gathering actions online. In addition to providing guarantees, we can capitalize on submodularity to attain additional computational speedups. We demonstrate the effectiveness of these methods in simulation and on a robot.
Cosmological cosmic strings.

The effect of an infinite cosmic string on a cosmological background is investigated. It is found that the metric is approximately a scaled version of the empty space string metric, i.e., conical in nature. Results are used to place bounds on the amount of cylindrical gravitational radiation currently emitted by such a string. The gravitational radiation equations are then analyzed explicitly and it is shown that even initially large disturbances are rapidly damped as the expansion proceeds. The implications of the gravitational radiation background and the limitations of the quadrupole formula are discussed.
The Lichnerowicz–Obata Theorem on Sub-Riemannian Manifolds with Transverse Symmetries

We prove a lower bound for the first eigenvalue of the sub-Laplacian on sub-Riemannian manifolds with transverse symmetries. When the manifold is of \(H\)-type, we obtain a corresponding rigidity result: If the optimal lower bound for the first eigenvalue is reached, then the manifold is equivalent to a 1- or a 3-Sasakian sphere.
Optical beam steering using a multichannel lithium tantalate crystal.

A multichannel phase modulator is described which employs the electrooptic properties of lithium tantalate to achieve phase modulation. The modulator’s speed and 2π voltage are compatible with high speed microelectronics The beam steering properties of this one-dimensional optical phased array antenna are described, and the beam steering results for a forty-six-channel modulator are given.
Does hysteroscopy improve upon the sensitivity of dilatation and curettage in the diagnosis of endometrial hyperplasia or carcinoma

Abstract Objective. The objective of this study was to determine whether hysteroscopy improved upon the diagnostic sensitivity of dilatation and curettage (D+C) in the detection of endometrial hyperplasia and carcinoma. Methods. A retrospective chart review was conducted of all patients undergoing hysteroscopy/D+C for abnormal uterine bleeding between 1991 and 1995. Hysteroscopic impressions and D+C diagnoses were compared. Results. Three hundred seventy-three patients were included in the study. Of the 61 patients with D+C demonstrating hyperplasia, the hysteroscopic impression was hyperplasia in 32 (52%). Of the 10 patients with D+C demonstrating carcinoma, the hysteroscopic impression was hyperplasia in 8 (80%) and carcinoma in 2 (20%). Two additional cases of carcinoma were diagnosed within 6 months of hysteroscopy/D+C, and both had been missed on both hysteroscopy and D+C. Of 204 patients with a normal hysteroscopic impression, 23 (11%) had hyperplasia on D+C. Conclusions. Hysteroscopy did not improve upon the sensitivity of D+C in the detection of endometrial hyperplasia or carcinoma.
Refined upper bounds for the linear Diophantine problem of Frobenius

We study the Frobenius problem: given relatively prime positive integers a"1,...,a"d, find the largest value of t (the Frobenius numberg(a"1,...,a"d)) such that @?"k"="1^dm"ka"k=t has no solution in nonnegative integers m"1,...,m"d. We introduce a method to compute upper bounds for g(a"1,a"2,a"3), which seem to grow considerably slower than previously known bounds. Our computations are based on a formula for the restricted partition function, which involves Dedekind-Rademacher sums, and the reciprocity law for these sums.
Dense nuclear matter: Landau Fermi-liquid theory and chiral Lagrangian with scaling☆

Abstract The relation between the effective chiral Lagrangian whose parameters scale according to Brown and Rho scaling (“BR scaling”) and Landau Fermi-liquid theory for hadronic matter is discussed in order to make a basis to describe the fluctuations under the extreme condition relevant to neutron stars. It is suggested that BR scaling gives the background around which the fluctuations are weak. A simple model with BR-scaled parameters is constructed and reproduces the properties of the nuclear ground state at normal nuclear matter density successfully. It shows that the tree level in the model Lagrangian is enough to describe the fluctuations around BR-scaled background. The model Lagrangian is consistent thermodynamically and reproduces relativistic Landau Fermi-liquid properties. Such points are important for dealing with hadronic matter under extreme condition. On the other hand, it is shown that the vector current obtained from the chiral Lagrangian is the same as that obtained from Landau–Migdal approach. We can determine the Landau parameter in terms of BR-scaled parameter. However, these two approaches provide different results, when applied to the axial charge. The numerical difference is small. It shows that the axial response is not included properly in the Landau–Migdal approach.
Motivic L-Function Identities from Cft and Arithmetic Mirror Symmetry

Exactly solvable mirror pairs of Calabi–Yau threefolds of hypersurface type exist in the class of Gepner models that include nondiagonal affine invariants. Motivated by the string theoretic automorphy established previously for models in this class, it is natural to ask whether the arithmetic structure of mirror pairs varieties reflects the fact that as conformal field theories, they are isomorphic. Mirror symmetry in particular predicts that the L-functions of the Ω-motives of such pairs are identical. In this paper this prediction is confirmed by showing that the Ω-motives of exactly solvable mirror pairs are isomorphic. This follows as a corollary of the proof of a more general result establishing an isomorphism between nondiagonally and diagonally induced motives in this class of varieties. The motivic approach formulated here circumvents the difficulty that no mirror construction of the Hasse–Weil zeta function is known.
Labor market dynamics over the business cycle: evidence from Markov switching models

This paper explores the evolution of the U.S. labor market across the business cycle and specifically the relationship between the unemployment rate and the average duration of unemployment. Labor market recoveries have long been thought of as lagging recoveries in broad economic activity. In particular, the unemployment rate peaks several months after official business cycle troughs and the average duration of unemployment lags further behind. Using estimates from Markov switching models of the unemployment rate, average duration of unemployment, jobless claims, and the exhaustion rate of regular unemployment insurance, this paper dates contractionary and expansionary phases of various aspects of the labor market and their relationship to the official phases of the business cycle. Evidence from these models suggests that inflows into unemployment recover almost contemporaneously with broad economic activity, while outflows recover almost a year after the end of official recessions. The differential timing in the recoveries of unemployment inflows and outflows, which is not a characteristic of most macro models of the labor market, accounts for the observed pattern between the unemployment rate and average duration of unemployment. Finally, when comparing the phases of the labor market to periods where Congress extends unemployment insurance benefits, it appears that policymakers target periods where the job finding rate is low, rather than periods where the stock of unemployed workers is high.
On the threshold of chaos in random Boolean cellular automata

A random boolean cellular automaton is a network of boolean gates where the inputs, the boolean function, and the initial state of each gate are chosen randomly. In this article, each gate has two inputs. Let a (respectively c) be the probability that the gate is assigned a constant function (respectively a noncanalyzing function, i.e., EQUIVALENCE or EXCLUSIVE OR). Previous work has shown that when a>c, with probability asymptotic to 1, the random automaton exhibits very stable behavior: Almost all of the gates stabilize, almost all of them are weak, i.e., they can be perturbed without affecting the state cycle that is entered, and the state cycle is bounded in size. This article gives evidence that the condition a = c is a threshold of chaotic behavior: with probability asymptotic to 1, almost all of the gates are still stable and weak, but the state cycle size is unbounded. In fact, the average state cycle size is superpolynomial in the number of gates. © 1995 Wiley Periodicals, Inc.
X-ray Time Lags in TeV Blazars

We use Monte Carlo/Fokker–Planck simulations to study the X-ray time lags. Our results show that soft lags will be observed as long as the decay of the flare is dominated by radiative cooling, even when acceleration and cooling time scales are similar. Hard lags can be produced in the presence of a competitive achromatic particle energy loss mechanism if the acceleration process operates on a time scale such that particles are slowly moved towards higher energy while the flare evolves. In this type of scenario, the γ-ray/X-ray quadratic relation is also reproduced.
Class, Race, and Higher Education in America

Class, Race, and Higher Education in America Martin Trow Goldman School of Public Policy University of California, Berkeley Social Class and Higher Education Mass higher education in the United States, with universal access in many places, has many functions that it shares with similar institutions around the world. However, it has one function which is perhaps unique to us: it is the central instrument for the legitimation of a society around the principle of broad (and in principle, equal), opportunities open to all individuals, opportunities to improve themselves and to make their careers and lives through their own efforts and talents. Our 3,500 accredited colleges and universities, offering course work at every level of standard and difficulty to an enormously diverse student body, serve a wide variety of functions for the students and for the society at large. While most of them offer some liberal and general studies, they serve as the chief avenue of entry to middle class occupations--even to quite modest lower-middle class occupations, which in most countries would not require or reward exposure to post-secondary education. These institutions, without the kinds of educational ceilings common in European non-university forms of post-secondary schooling, encourage students to raise their aspirations through further study, full or part- time, and provide the possibility of transfer to advanced studies elsewhere if they do not have such provisions themselves. They thus reflect and reinforce the radical individualism of American values, a set of values deeply opposed to socialist principles which center on cooperative efforts at group advancement, and on the common effort to create a society whose members all profit (more or less equally) from the common effort. American higher education, as a system, both serves and celebrates the American Dream of individual careers open to talents, a dream given much of its institutional reality in the contemporary world precisely by America's system of mass higher education offering a clear alternative to socialist principles of class identification and horizontal loyalty. The contrast between these competitive visions is captured in the stirring appeal of Eugene Debs, the last socialist leader in the United States with any significant following (he gained nearly a million votes Published in Gary Marks and Larry Diamond, eds., Reexamining Democracy, London, Sage Publications, 1992, pp. 275-293.
Phonons in a nanoparticle mechanically coupled to a substrate

The discrete nature of the vibrational modes of an isolated nanometer-scale solid dramatically modifies its low-energy electron and phonon dynamics from that of a bulk crystal. However, nanocrystals are usually coupled\char22{}even if only weakly so\char22{}to an environment consisting of other nanocrystals, a support matrix, or a solid substrate, and this environmental interaction will modify the vibrational properties at low frequencies. In this paper we investigate the modification of the vibrational modes of a spherical insulating nanoparticle caused by a weak mechanical coupling to a semi-infinite substrate. The phonons of the bulk substrate act as a bath of harmonic oscillators, and the coupling to this reservoir shifts and broadens the nanoparticle's modes. The vibrational density of states in the nanoparticle is obtained by solving the Dyson equation for the phonon propagator, and we show that environmental interaction is especially important at low frequencies. As a probe of the modified phonon spectrum, we consider nonradiative energy relaxation of a localized electronic impurity state in the nanoparticle, for which good agreement with a recent experiment is found.
Optical properties of cesium iodide

The refractive indices of CsI were determined at three temperatures near 15, 24, and 34°C for wavelengths from 0.29 micron in the ultraviolet to 53 microns in the infrared. The thermal coefficients of index were determined for each wavelength and all data were reduced to 24°C. A dispersion equation of the Sellmeier type having five terms was fitted to these data. Four of the terms contained absorption wavelengths which were either known experimentally or had been computed from the lattice constants of the crystal. The fifth was adjusted to fit the data and has a value of about 0.02 micron. The formula was extrapolated to infinite wavelength, and the value of n∞2 agreed with the known dielectric constant at 30 cm. The dispersion of CsI for infrared wavelengths from about 30 to 40 microns is less than that of CsBr but only by a factor of about 2. At 50 microns the dispersion of CsI is practically equal to the 40-micron dispersion of CsBr.
Null propagation of partially massless higher spins in (A)dS and cosmological constant speculations

We show explicitly that all partially and strictly massless fields with spins s⩽3 in (A)dS have null propagation. Assuming that this property holds also for s>3, we derive the mass-cosmological constant tunings required to yield all higher spin partially massless theories. As s increases, the unitarily allowed region for massive spins is squeezed around Λ=0, so that an infinite tower of massive particles forces vanishing Λ. We also speculate on the relevance of this result to string theory and supergravity in (A)dS backgrounds.
Coupling of 3,8-Dibromo-1,10-phenanthroline with 3,5-Diethynylheptyloxybenzene: A Suzuki/Miyaura Versus a Sonogashira Perspective

We report a new application of the Suzuki-Miyaura reaction whereas two bifunctional reactants, 3,8-dibromo-1,10-phenanthroline and 3,5-diethynylheptyloxylbenzene (9), yield 3,8-bis (3-ethynyl-5-heptyloxyphenylethynyl)-1,10-phenanthroline (2) efficiently (74% yield) without polymerization. This was achieved by reacting a stoichiometric amount of 9 and (Me3Si)2NLi to obtain quantitatively the monoacetylide anion of 9 (10). The latter was activated with B-methoxy-9-BBN and reacted in analogy to the alkynyl copper complex of a Sonogashira route. However, in the Sonogashira reaction, the alkynyl copper complex is present in small equilibrium concentrations and polymerization takes place even when reagents are mixed slowly. Actually the Sonogashira route gave no desired product 2, as the latter polymerizes easily via homo-coupling in the presence of air and Cu(I). Sonogashira coupling involves the palladium(0) catalyzed reaction of terminal alkynes.
A study of scalar compilation techniques for pipelined supercomputers

This paper studies two compilation techniques for enhancing scalar performance in high-speed scientific processors: software pipelining and loop unrolling. We study the impact of the architecture (size of the register file) and of the hardware (size of instruction buffer) on the efficiency of loop unrolling. We also develop a methodology for classifying software pipelining techniques. For loop unrolling, a straightforward scheduling algorithm is shown to produce near-optimal results when not inhibited by recurrences or memory hazards. Our study indicates that the performance produced with a modified CRAY-1S scalar architecture and a code scheduler utilizing loop unrolling is comparable to the performance achieved by the CRAY-1S with a vector unit and the CFT vectorizing compiler.Finally, we show that the combination of loop unrolling and dynamic software pipelining, as implemented by a decoupled computer, substantially outperforms the vector CRAY-1S.
Free energy surfaces from nonequilibrium processes without work measurement

Recent developments in statistical mechanics have allowed the estimation of equilibrium free energies from the statistics of work measurements during processes that drive the system out of equilibrium. Here a different class of processes is considered, wherein the system is prepared and released from a nonequilibrium state, and no external work is involved during its observation. For such "clamp-and-release" processes, a simple strategy for the estimation of equilibrium free energies is offered. The method is illustrated with numerical simulations and analyzed in the context of tethered single-molecule experiments.
Dual Functional Polyelectrolyte Multilayer Coatings for Implants: Permanent Microbicidal Base with Controlled Release of Therapeutic Agents

Here we present a new bifunctional layer-by-layer (LbL) construct made by combining a permanent microbicidal polyelectrolyte multilayered (PEM) base film with a hydrolytically degradable PEM top film that offers controlled and localized delivery of therapeutics. Two degradable film architectures are presented: (1) bolus release of an antibiotic (gentamicin) to eradicate initial infection at the implant site, or (2) sustained delivery of an anti-inflammatory drug (diclofenac) to cope with inflammation at the site of implantation due to tissue injury. Each degradable film was built on top of a permanent base film that imparts the implantable device surface with microbicidal functionality that prevents the formation of biofilms. Controlled-delivery of gentamicin was demonstrated over hours and that of diclofenac over days. Both drugs retained their efficacy upon release. The permanent microbicidal base film was biocompatible with A549 epithelial cancer cells and MC3T3-E1 osteoprogenitor cells, while also pre...
Optical Hall conductivity of systems with gapped spectral nodes

We calculate the optical Hall conductivity within the Kubo formalism for systems with gapped spectral nodes, where the latter have a power-law dispersion with exponent n. The optical conductivity is proportional to n and there is a characteristic logarithmic singularity as the frequency approaches the gap energy. The optical Hall conductivity is almost unaffected by thermal fluctuations and disorder for n = 1, whereas disorder has a stronger effect on transport properties if n = 2.
Scale effects in buckling, postbuckling and crippling of graphite-epoxy Z-section stiffeners

Variables adressed are flange and web widths, flange-to-web corner radii, thickness, and stacking sequence. Analytical, numerical, and experimental results are discussed. Nondimensional parameters have been obtained from an analytical model which effectively normalize the initial local buckling data reported herein and in the literature
Advanced Electron Optics for Vibrational Spectroscopy.

Abstract Requirements for a “next generation” high resolution electron energy loss spectrometer for probing surface vibrations are proposed based on several specific applications in which the performance of present generation instruments is marginal or totally inadequate. Prospects of achieving significant improvements are explored and found to be very good for applications which involve studies of impact scattering phenomena. Results of zoom lens ray tracing studies, analysis of electron trajectories and exit plane images in a hemispherical analyzer in relation to multichannel energy detection and studies of electron trajectories near various field terminators are presented. A prototype analyzer / monochromator design is described which will be used to test the model calculations and to extend the applications of EELS to more detailed studies of impact scattering.
Cosmic rays in the heliosphere

This is a rapporteur paper for the XXIV International Cosmic-Ray Conference covering topics of anomalous cosmic rays, shock acceleration, modulation and transport theory, cosmic-ray gradients, corotating interaction regions, coronal-mass ejections, and solar neutrinos. Among the highlights of the meeting are —conclusive proof that most anomalous cosmic rays are singly charged,—undisputed detection of anomalous cosmic-ray hydrogen,—discovery of unexpectedly large anisotropies of pickup ions,—observation of pronounced solar rotational modulation of cosmic-ray fluxes to the highest heliolatitudes (∼80°) probed by the Ulysses spacecraft, and—new measurements of modulation effects sensitive to particle charge sign.
A New and Efficient Conversion of Alkylphenols into the Corresponding Substituted Salicylic Acids

Abstract A three-step sequence suitable for the synthesis of alkyl substituted salicylic acids from the corresponding alkylphenols involves ortho-directed lithiation of the methoxymethyl aryl ethers followed by quenching with carbon dioxide and deprotection under acidic conditions.
Quasar Outflow Contribution to AGN Feedback: Observations of QSO SDSS J0838+2955

We present a detailed analysis of the Astrophysical Research Consortium 3.5 m telescope spectrum of QSO SDSS J0838+2955. The object shows three broad absorption line (BAL) systems at 22,000, 13,000, and 4900 km s{sup -1} blueshifted from the systemic redshift of z = 2.043. Of particular interest is the lowest velocity system that displays absorption from low-ionization species such as Mg II, Al II, Si II, Si II*, Fe II, and Fe II*. Accurate column densities were measured for all transitions in this lowest velocity BAL using an inhomogeneous absorber model. The ratio of column densities of Si II* and Fe II* with respect to their ground states gave an electron number density of log n{sub e} (cm{sup -3}) = 3.75 +- 0.22 for the outflow. Photoionization modeling with careful regards to chemical abundances and the incident spectral energy distribution predicts an ionization parameter of log U{sub H} = -1.93 +- 0.21 and a hydrogen column density of log N{sub H} (cm{sup -2}) = 20.80 +- 0.28. This places the outflow at 3.3{sup +1.5}{sub -1.0} kpc from the central active galactic nucleus (AGN). Assuming that the fraction of solid angle subtended by the outflow is 0.2, these values yield amore » kinetic luminosity of (4.5{sup +3.1}{sub -1.8}) x 10{sup 45} erg s{sup -1}, which is (1.4{sup +1.1}{sub -0.6})% the bolometric luminosity of the QSO itself. Such large kinetic luminosity suggests that QSO outflows are a major contributor to AGN feedback mechanisms.« less
CUSPIDAL REPRESENTATIONS OF sl(n + 1)

Abstract In this paper we study the subcategory of cuspidal modules of the category of weight modules over the Lie algebra sl ( n + 1 ) . Our main result is a complete classification and an explicit description of indecomposable cuspidal modules.
Ultrafast optical response of YBCO superconductors

Picosecond voltage pulses were generated in YBCO microstriplines by irradiation with a picosecond laser. An autocorrelation method was proposed and applied to measure the temporal decay of these ultrafast voltage pulses. It was also ascertained that these pulses were generated in the superconducting state. Using a 40 ps laser, voltage pulses with fast components < 40 ps were obtained. This fast decay was dependent on the bias current. There were also significant thermal components in these pulses. Methods of generating even shorter pulses are discussed.
The galactic magnetic field

With this Letter, we complete our model of the Galactic magnetic field (GMF), by using the WMAP7 22 GHz total synchrotron intensity map and our earlier results to obtain a 13-parameter model of the Galactic random field, and to determine the strength of the striated random field. In combination with our 22-parameter description of the regular GMF, we obtain a very good fit to more than 40,000 extragalactic Faraday rotation measures and the WMAP7 22 GHz polarized and total intensity synchrotron emission maps. The data call for a striated component to the random field whose orientation is aligned with the regular field, having zero mean and rms strength Almost-Equal-To 20% larger than the regular field. A noteworthy feature of the new model is that the regular field has a significant out-of-plane component, which had not been considered earlier. The new GMF model gives a much better description of the totality of data than previous models in the literature.
Compressive deformation and yielding mechanisms in cellular Al alloys determined using X-ray tomography and surface strain mapping

The mechanisms of compressive deformation that occur in both closed and open cell Al alloys have been established. This has been achieved by using X-ray computed tomography (CT) and surface strain mapping to determine the deformation modes and the cell morphologies that control the onset of yielding. The deformation is found to localize in narrow bands having widths of order of a cell diameter. Outside the bands, the material remains elastic. The cells within the bands that experience large permanent strains are primarily elliptical. A group of cells work collectively to allow large localized deformation. Size does not appear to be the initiator of the deformation bands. Equiaxed cells remain elastic. The implications for manufacturing materials with superior mechanical properties are discussed.
SigFree: A Signature-Free Buffer Overflow Attack Blocker

We propose SigFree, an online signature-free out-of-the-box application-layer method for blocking code-injection buffer overflow attack messages targeting at various Internet services such as Web service. Motivated by the observation that buffer overflow attacks typically contain executables whereas legitimate client requests never contain executables in most Internet services, SigFree blocks attacks by detecting the presence of code. Unlike the previous code detection algorithms, SigFree uses a new data-flow analysis technique called code abstraction that is generic, fast, and hard for exploit code to evade. SigFree is signature free, thus it can block new and unknown buffer overflow attacks; SigFree is also immunized from most attack-side code obfuscation methods. Since SigFree is a transparent deployment to the servers being protected, it is good for economical Internet-wide deployment with very low deployment and maintenance cost. We implemented and tested SigFree; our experimental study shows that the dependency-degree-based SigFree could block all types of code-injection attack packets (above 750) tested in our experiments with very few false positives. Moreover, SigFree causes very small extra latency to normal client requests when some requests contain exploit code.
Reel Latinas? Race, gender, and asymmetric recognition in contemporary film

This article argues that idealized portrayals of immigrants prevalent in political discourse must be scrutinized for their support of gender and racial nationalism and the effects they have on our understanding of (Latina/o) immigrant inclusion and democracy. Through the examination of three contemporary films with Latina leads – Real Women Have Curves, Spanglish, and Quinceanera – the article argues that these discourses rely on an asymmetric recognition of Latina/os. This form of recognition involves the denial by dominant groups of their inter-dependency with other groups and the imposition on Latina/os of an identity that does not threaten their privileged standing. The films offer views of Latina/o culture as overtly traditional; a “culture” that must either be abandoned or appropriated by anti-feminist (postfeminist) agendas in order to assuage anxieties regarding the transformations of the heteronormative middle-class family. The article concludes by drawing parallels between the positive portrayal...
How Did the 2003 Dividend Tax Cut Affect Stock Prices

We test the hypothesis that the 2003 dividend tax cut boosted US stock prices and thereby lowered the cost of equity capital. Using an event-study methodology, we attempt to identify an aggregate stock market effect by comparing the behavior of US common stock prices with that of foreign equities and the equities of real estate investment trusts (REITs). We also examine the relative cross-sectional response of prices of high- and low-dividend-paying stocks. We do not find any imprint of the dividend tax cut news on the value of the aggregate US stock market. On the other hand, high-dividend stocks outperformed low-dividend stocks by a few percentage points over the event windows, suggesting that the tax cut may have induced asset reallocation within equity portfolios. Finally, the positive abnormal return on nondividend paying US stocks in 2003 does not appear to be tied to tax cut news.
pH-Sensitive exciton chirality chromophore. Solvatochromic effects on circular dichroism spectra

Abstract Diesters ( 1 and 3 ) of (1 S ,2 S ) and (1 R ,2 R )-cyclohexanediol and diamides ( 2 and 4 ) of (1 S ,2 S ) and (1 R ,2 R )-diaminocyclohexane with p -hydroxycinnamic acid exhibit intense bisignate circular dichroism spectra in CH 3 OH: 1 Δɛ +55 (323 nm), −34 (287 nm); 2 Δɛ +75 (318 nm), −55 (281 nm) and in (CH 3 ) 2 SO: 1 Δɛ +53 (328 nm), −33 (292 nm); 2 Δɛ +65 (319 nm), −50 (280 nm). Added NaOH causes a bathochromic shift of ∼50 nm in CH 3 OH and ∼80 – 90 nm in (CH 3 ) 2 SO.
Analysis of Bimodality in Histograms Formed from GALLEX and GNO Solar Neutrino Data

A histogram display of the solar neutrino capture-rate measurements made by the GALLEX experiment appears to be bimodal, but that of the follow-on GNO experiment does not. To assess the significance of these results, we introduce a “bimodality index” based on the probability-transform procedure. This confirms that the GALLEX measurements are indeed bimodal (at the 99.98% confidence level) and that the GNO measurements are not. Tracking the bimodality index as a function of time shows that the strongest contribution to bimodality comes from runs 42 to 62 (i.e., from the time interval 1995.1 to 1996.9). The bimodality index for the first half (runs 1 through 33) is 2.56, whereas that for the second half (runs 33 through 65) is 7.05. A power-spectrum analysis shows a similar distinction: The peaks in the power spectrum formed from the second half are stronger than those in the power spectrum formed from the first half, suggesting that bimodality and rotational modulation are related.
Ring inversion in 5,5-disubstituted 1,3-dioxanes

The conformational mobility was studied by dynamic PMR and the free energies of activation of the conformational transitions of 5,5-bis(chloromethyl)-, 5,5-bis(iodomethyl)- and 2,3-pentamethylene-bis-5,5-bis(chloromethyl)-1,3-dioxanes were determined.
Surface ablation in the impingement region of a liquid jet

A theoretical and experimental investigation of a water jet impinging on a melting solid surface has been carried out. Ice, octane, p-xylene, and olive oil served as the meltable solid materials, comprising a Prandtl number range of 5 to 2800. An available laminar stagnation flow model was utilized to describe melting heat transfer in the jet impingement region. Melting rate measurements were found to agree quite well with the values predicted with this model.
Measuring agreement in medical informatics reliability studies

Agreement measures are used frequently in reliability studies that involve categorical data. Simple measures like observed agreement and specific agreement can reveal a good deal about the sample. Chance-corrected agreement in the form of the kappa statistic is used frequently based on its correspondence to an intraclass correlation coefficient and the ease of calculating it, but its magnitude depends on the tasks and categories in the experiment. It is helpful to separate the components of disagreement when the goal is to improve the reliability of an instrument or of the raters. Approaches based on modeling the decision making process can be helpful here, including tetrachoric correlation, polychoric correlation, latent trait models, and latent class models. Decision making models can also be used to better understand the behavior of different agreement metrics. For example, if the observed prevalence of responses in one of two available categories is low, then there is insufficient information in the sample to judge raters' ability to discriminate cases, and kappa may underestimate the true agreement and observed agreement may overestimate it.
Grid evolution in time asymptotic problems

The selection of the proper coordinate system in solving any fluid flow or heat transfer problem is a very important consideration. A new technique of moving mesh points in physical space is introduced so as to reduce the error in a computed asymptotic solution relative to that obtained using a fixed mesh. The technique has been used to solve the simple viscous Burgers' equation in one and two dimensions. Substantial error reductions are demonstrated. The treatment of boundary points and the effect of using different error criteria in generating grids are discussed.
Effective Limiting Absorption Principles, and Applications

The limiting absorption principle asserts that if H is a suitable Schrodinger operator, and f lives in a suitable weighted L2 space (namely \({H^{0, 1/2 + \sigma}}\) for some \({\sigma > 0}\)), then the functions \({R(\lambda + i \varepsilon) f := (H - \lambda - i \varepsilon)^{-1} f}\) converge in another weighted L2 space \({H^{0, -1/2 - \sigma}}\) to the unique solution u of the Helmholtz equation \({(H - \lambda) u = f}\) which obeys the Sommerfeld outgoing radiation condition. In this paper, we investigate more quantitative (or effective) versions of this principle, for the Schrodinger operator on asymptotically conic manifolds with short-range potentials, and in particular consider estimates of the form $$\| R(\lambda + i \varepsilon) f \|_{H^{0, -1/2 - \sigma}} \leq C(\lambda, H) \| f \|_{H^{0, 1/2 + \sigma}}.$$ We are particularly interested in the exact nature of the dependence of the constants \({C(\lambda, H)}\) on both \({\lambda}\) and H. It turns out that the answer to this question is quite subtle, with distinctions being made between low energies \({\lambda \ll 1}\), medium energies \({\lambda \sim 1}\), and large energies \({\lambda \gg 1}\), and there is also a non-trivial distinction between “qualitative” estimates on a single operator H (possibly obeying some spectral condition such as non-resonance, or a geometric condition such as non-trapping), and “quantitative” estimates (which hold uniformly for all operators H in a certain class). Using elementary methods (integration by parts and ODE techniques), we give some sharp answers to these questions. As applications of these estimates, we present a global-in-time local smoothing estimate and pointwise decay estimates for the associated time-dependent Schrodinger equation, as well as an integrated local energy decay estimate and pointwise decay estimates for solutions of the corresponding wave equation, under some additional assumptions on the operator H.
Do physical neighborhood characteristics matter in predicting traffic stress and health outcomes

This study examines whether social, and physical environment characteristics related to urban design interact with individual perceptions of traffic stress to influence individual well-being. The Chinese American Psychiatric Epidemiologic Study data, the US census data, and the Geographic Information System (GIS) data are employed. Analyses used hierarchical linear modeling. The results indicate that perceived traffic stress was associated with lower health status and higher depression. More importantly, higher density of major streets and greater vehicular burden in the neighborhood pose potential harm to health by reinforcing the negative impacts of perceived traffic stress. On the other hand, more park land in the neighborhood could alleviate the damage of traffic stress on individual’s well-being. The implications of the results for future research are discussed.
A geometrical construction of rational boundary states in linear sigma models

Abstract Starting from the geometrical construction of special Lagrangian submanifolds of a toric variety, we identify a certain subclass of A-type D-branes in the linear sigma model for a Calabi–Yau manifold and its mirror with the A- and B-type Recknagel–Schomerus boundary states of the Gepner model, by reproducing topological properties such as their labeling, intersection, and the relationships that exist in the homology lattice of the D-branes. In the non-linear sigma model phase these special Lagrangians reproduce an old construction of 3-cycles relevant for computing periods of the Calabi–Yau, and provide insight into other results in the literature on special Lagrangian submanifolds on compact Calabi–Yau manifolds. The geometrical construction of rational boundary states suggests several ways in which new Gepner model boundary states may be constructed.
First-Order Approach to Principal-Agent Problems: A Generalization

The first-order approach (FOA) to principal agent problems is very convenient and mathematically tractable. However, existing results show that the FOA is valid only for additively separable utility functions. This is somewhat limiting. In this article sufficient conditions are identified that extend the validity of the FOA to nonseparable cases. The additional conditions involve restrictions on the agent's preferences, particularly interactions between action and the wage contract. These conditions imply that leisure is normal and the agent's absolute risk aversion increases with action. Comparative static results regarding the wage contract and its gradient are also discussed.
The Calkin algebra has outer automorphisms

Assuming the continuum hypothesis, we show that the Calkin algebra has 2^{aleph_1} outer automorphisms.
A convenient in situ procedure for effecting inter- and intramolecular Diels-Alder reactions of N-sulfonyl imines

Abstract Treatment of an aldehyde and a 1,3-diene with N-sulfinyl-p-toluenesulfonamide/boron trifluoride etherate leads to products of an imino Diels-Alder reaction via an N-sulfonyl imine produced in situ.
Dual fast-cycling superconducting synchrotron at Fermilab and a possible path to the future of high energy particle physics

We briefly outline shorter and longer term physics motivation for constructing a dual, fast-cycling superconducting synchrotron accelerator (DSFMR — Dual Super-Ferric Main Ring) in the Tevatron tunnel at Fermilab. We discuss using this accelerator as a high-intensity dual neutrino beam source for the long-baseline neutrino oscillation search experiments, and also as a fast, dual pre-injector accelerator for the VLHC (Very Large Hadron Collider).
Effects of Dopamine and Metoclopramide in Polycystic Ovary Syndrome

A relative deficiency in dopamine has been suggested to explain the inappropriate gonadotropin secretion and postulated increased GnRH secretion characteristic of polycystic ovary syndrome (PCO). Previous studies demonstrated an exaggerated decrement in serum LH after large iv doses of dopamine (DA, 4-5 µg/kg-min). Normoplactinemic patients with PCO and weight- and estrogen-matched normal women received iv infusions of DA in two doses (0.5 and 4 µg/kg-min). After A, each subject also received iv metoclopramide (MCP; 10 mg). Serum LH decreased (P < 0.05) during DA infusion to a similar degree in PCO [23 ± 3% (±SE)] and normal women (20 ± 2%). In PCO patients, the decrease in LH was similar with both DA doses. Serum PRL and TSH responses to DA were also similar in PCO and normal women. After MCP treatment, serum LH did not change, but serum PRL increased more in PCO (801 ± 100%) than in normal women (467 ± 73%; P ± 0.05), as did serum TSH. These data suggest that the sensitivity of LH to DA in patients with...
On achievable rate regions for half-duplex causal cognitive radio channels

Coding for the causal cognitive radio channel, with the cognitive source subjected to a half-duplex constraint, is studied. A discrete memoryless channel model incorporating the half-duplex constraint is presented, and a new achievable rate region is derived for this channel. It is proved that this rate region contains the previously known causal achievable rate region of [1] for Gaussian channels.
From confrontation to collaboration: collegial accountability and the expanding role of pharmacists in the management of chronic pain.

Federal and state laws create a tightly controlled system for distribution of those drugs that have recognized value in therapy, but also have the potential for abuse. The challenges pharmacists face in keeping controlled substances within the closed system are many and complex. Drug abusers and drug dealers have at times seen pharmacists as easy marks for access to abusable drugs. Unfortunately, pharmacists often find themselves in a game with criminals, who use both sophisticated and dangerous methods of inducing pharmacists to divert controlled substances. The effects of this problem on the health-care system have been judicially noted: The frequency of these crimes has terrorized the community of dispensing pharmacists. Some pharmacists have ceased to carry drugs that are highly desired on the black market, although this interferes with their patients’ ability to obtain necessary medicine. This has a serious potential to impede the delivery of health care in many communities around the nation.
In Situ Scanning Tunneling Microscopic Study of the Corrosion of Type 304L Stainless Steel in Aqueous Chloride Media

Demonstration de la possibilite d'utilisation d'un microscope tunnel a balayage pour l'etude de la corrosion de l'acier inoxydable type 304 dans une solution aqueuse de NaCl. Description des effets d'un inhibiteur organique de corrosion, de la concentration en chlorure et du pH sur les images obtenues par microscopie tunnel a balayage.
Preparation of nitronium tetrafluoroborate free of nitrosonium ions

Preparation par reaction d'acide nitrique anhydre, HF anhydre et BF 3 anhydre; on obtient un rendement de 95% sans NOBF 4 . Determination de la teneur en NO +
Radiation fields for semilinear wave equations

We define the radiation fields of solutions to critical semilinear wave equations in R^3 and use them to define the scattering operator. We also prove a support theorem for the radiation fields with radial initial data. This extends the well known support theorem for the Radon transform to this setting and can also be interpreted as a Paley-Wiener theorem for the distorted nonlinear Fourier transform of radial functions.