cssi/SciSciGPT-SciSciNet huggingface dataset:
Fundamental limit of light trapping in grating structures.

We use a rigorous electromagnetic approach to analyze the fundamental limit of light-trapping enhancement in grating structures. This limit can exceed the bulk limit of 4n2, but has significant angular dependency. We explicitly show that 2D gratings provide more enhancement than 1D gratings. We also show the effects of the grating profile’s symmetry on the absorption enhancement limit. Numerical simulations are applied to support the theory. Our findings provide general guidance for the design of grating structures for light-trapping solar cells.
Salt intake, blood pressure and clinical outcomes.

Purpose of review Salt intake has long been known to influence blood pressure among hypertensive patients, but its effect among those without overt hypertension, as well as its effects on cardiovascular disease itself, have been disputed. This report reviews the evidence for an effect on both blood pressure and cardiovascular disease, particularly among normotensive participants, including recent data from randomized trials. Recent findings The Dietary Approaches to Stop Hypertension study provided clear evidence for a short-term effect of sodium on blood pressure among those with and without hypertension. Longer term trials among nonhypertensive particpants suggest more modest effects of lifestyle sodium reduction interventions on blood pressure. The recent Trials of Hypertension Prevention follow-up study found that, despite small changes in blood pressure, the risk of cardiovascular disease was reduced by 25% among those in the sodium reduction intervention. A study of potassium salt substitution among Taiwanese veterans supports this finding. Sodium and potassium may act jointly in the development of hypertension and cardiovascular disease. Summary Average sodium consumption in the US population is excessively high, and well above recommended limits. Because most sodium derives from processed and restaurant foods, a reduction of sodium in these sources, as recently called for by the American Medical Association, is necessary to reduce exposure.
Direct-sequence spread-spectrum parallel acquisition in a fading mobile channel

A parallel acquisition scheme for direct-sequence spread-spectrum systems is proposed, and its mean acquisition time performance is analyzed in both nonfading and Rayleigh-fading environments. An expression for the mean acquisition time is derived in terms of the probabilities of detection, missing, and false alarm. These parameters are first analyzed for a typical AWGN (additive white Gaussian noise) channel, then the Rayleigh-fading channel encountered in a typical UHF or microwave land mobile radio channel is studied. The channel is assumed frequency nonselective, and the effect of data modulation and code Doppler is not considered. The performance of the parallel system is compared to the corresponding serial system, and it is shown that a significant improvement can be achieved. >
Absence of phase transition for antiferromagnetic Potts models via the Dobrushin uniqueness theorem

We prove that theq-state Potts antiferromagnet on a lattice of maximum coordination numberr exhibits exponential decay of correlations uniformly at all temperatures (including zero temperature) wheneverq>2r. We also prove slightly better bounds for several two-dimensional lattices: square lattice (exponential decay forq≥7), triangular lattice (q≥11), hexagonal lattice (q≥4), and Kagome lattice (q≥6). The proofs are based on the Dobrushin uniqueness theorem.
Velocity analysis using nonhyperbolic moveout in transversely isotropic media

P-wave reflections from horizontal interfaces in transversely isotropic (TI) media have nonhyperbolic moveout. It has been shown that such moveout as well as all time-related processing in TI media with a vertical symmetry axis (VTI media) depends on only two parameters, V{sub nmo} and {eta}. These two parameters can be estimated from the dip-moveout behavior of P-wave surface seismic data. Alternatively, one could use the nonhyperbolic moveout for parameter estimation. The quality of resulting estimates depends largely on the departure of the moveout from hyperbolic and its sensitivity to the estimated parameters. The size of the nonhyperbolic moveout in TI media is dependent primarily on the anisotropy parameter {eta}. An effective version of this parameter provides a useful measure of the nonhyperbolic moveout even in v(z) isotropic media. Moreover, effective {eta}, {eta}{sub eff}, is used to show that the nonhyperbolic moveout associated with typical TI media (e.g., shales, with {eta} {approx_equal} 0.1) is larger than that associated with typical v(z) isotropic media. The departure of the moveout from hyperbolic is increased when typical anisotropy is combined with vertical heterogeneity. Although estimation of {eta} using nonhyperbolic moveouts is not as stable as using the dip-moveout method of Alkhalifah and Tsvankin, particularlymore » in the absence of large offsets, it does offer some flexibility. It can be applied in the absence of dipping reflectors and also may be used to estimate lateral {eta} variations. Application of the nonhyperbolic inversion to data from offshore Africa demonstrates its usefulness, especially in estimating lateral and vertical variations in {eta}.« less
The Role of Estrogen Replacement Therapy in the Management of Urinary Incontinence and Urinary Tract Infection in Postmenopausal Women

Urinary complaints such as urinary incontinence, urinary tract infections, nocturia, and urinary urgency are common in women. The prevalence of these urinary conditions increases with age. Factors which are related to a rise in urinary complaints include age-related changes in bladder and urethral function, comorbid medical conditions, medications, and changes in the hormonal milieu. In fact, some studies have shown a distinct rise in the prevalence of urinary incontinence after
Experiments with heavy ions

Abstract A method of producing small but usable numbers of very heavy ions in a tandem Van de Graaff accelerator, having energies up to 120 MeV, will be described in detail. Experiments with these ions have included studies of the responses of various types of Si detectors and studies of the stopping powers of several elements for heavy ions.
On the gradient estimate of Cheng and Yau

We improve the well known local gradient estimate of Cheng and Yau in the case when Ricci curvature has a negative lower bound.
Effective field theory and electroweak processes in nuclei

The accurate theoretical treatment of low-energy electroweak processes in lightest nuclei is of great current importance not only in the context of nuclear physics per se but also from the astrophysical and particle-physics viewpoints. I give a brief survey of the recent remarkable progress in this domain.
Positron annihilation in solid and liquid Ni

Analyses of the Doppler-broadening energy spectra for positrons annihilating in solid and liquid Ni are reported. Comparisons are made among the momentum distributions of positron-electron pairs annihilating in the essentially defect-free lattice, the vacancy and the liquid state of Ni. An interesting similarity in the distribution of momenta is reported for positrons annihilating in vacancies at high temperatures and those annihilating in liquid Ni.
Improved sustained response following treatment of chronic hepatitis C by gradual reduction in the interferon dose.

Abstract Interferon (IFN) treatment of chronic hepatitis C virus (HCV) is associated with a high rate of relapse. IFN is thought to exert its effect against HCV via direct viral inhibition and immune stimulation. We have hypothesized that relapse following termination of therapy results from the sudden withdrawal of this immune modulatory effect and that gradual reduction in the IFN dose may decrease the incidence of relapse. One hundred six patients with chronic HCV were enrolled into this 24-month controlled, randomized prospective trial. All were treated with 5 mU of interferon-alpha-2b three times a week for 6 months. Patients who achieved biochemical response were randomized to either stop or taper IFN gradually at monthly intervals as follows; 3 mU, 2 mU, 1 mU, and 0.5 mU (all three times a week). 0.5 mU twice weekly and then once weekly. Liver histology was assessed by Knodell index and HCV RNA was measured by a quantitative polymerase chain reaction (PCR) assay. Of the 92 patients who completed the initial 6 months of IFN treatment, 47 (51%) achieved biochemical response. Twenty-one of these patients were randomized to stop IFN treatment and 25 to taper (1 drop-out). At randomization patients were well matched with respect to age, sex, race, serum alanine transaminase (ALT), and liver histology. Biochemical relapse was observed in 19 of 21 (91%) patients who stopped IFN treatment compared with only 60% who tapered IFN (P= .04). Virological relapse occurred in 90% of patients who stopped and only 48% of persons who tapered IFN therapy. At completion of the 24-month study patients who achieved long-term sustained biochemical response had a significantly lower mean Knodell score (3.5 vs. 6.5) and a significantly greater number were HCV RNA negative in serum (85% vs. 18%) compared with relapsers. We conclude that gradual reduction in IFN dose is associated with a significant higher rate of sustained response and clearance of HCV RNA from serum compared with abruptly stopping treatment. This in turn is associated with a significant improvement in hepatic histology supporting the premise that response to IFN therapy can prevent progression to cirrhosis. (Hepatology 1996 Jul;24(1):21-6)
Plant specification of generic human-error data through a two-stage Bayesian approach

Expert judgement concerning human performance in nuclear power plants is quantitatively coupled with actuarial data on such performance in order to derive plant-specific human-error rate probability distributions. The coupling procedure consists of a two-stage application of Bayes' theorem to information which is grouped by type. The first information type contains expert judgement concerning human performance at nuclear power plants in general. Data collected on human performance at a group of similar plants forms the second information type. The third information type consists of data on human performance in a specific plant which has the same characteristics as the group members. The first and second information types are coupled in the first application of Bayes' theorem to derive a probability distribution for population performance. This distribution is then combined with the third information type in a second application of Bayes' theorem to determine a plant-specific human-error rate probability distribution. The two-stage Bayesian procedure thus provides a means to quantitatively couple sparse data with expert judgement in order to obtain a human performance probability distribution based upon available information. Example calculations for a group of like reactors are also given.
Sensitivity of CO2 migration estimation on reservoir temperature and pressure uncertainty

Abstract The density and viscosity of supercritical CO2 are sensitive to pressure and temperature (PT) while the viscosity of brine is sensitive primarily to temperature. Oil field PT data in the vicinity of WESTCARB’s Phase III injection pilot test site in the southern San Joaquin Valley, California, show a range of PT values, indicating either PT uncertainty or variability. Numerical simulation results across the range of likely PT indicate brine viscosity variation causes virtually no difference in plume evolution and final size, but CO2 density variation causes a large difference. Relative ultimate plume size is almost directly proportional to the relative difference in brine and CO2 density (buoyancy flow). The majority of the difference in plume size occurs during and shortly after the cessation of injection.
On the Role of Magnetic Fields in Abundance Determinations

Although there is considerable evidence supporting an ubiquitous magnetic field in solar/stellar photospheres, its impact in the determination of abundances has never been quantified. In this work we investigate whether the magnetic field plays a measurable role for this kind of study. To that end, we carry out simulations of spectral line formation in the presence of a magnetic field and then use those profiles to derive the abundance of several atomic species (Fe, Si, C, and O), neglecting the magnetic field. In this way, we find that the derived iron abundance can be significantly biased, with systematic errors of up to 0.1 dex. In the case of silicon, carbon, and oxygen, their role is very marginal (errors smaller than 0.02 dex). We also find that the effect of the magnetic field strongly depends on its inclination with respect to the observer. We show that fields that are aligned with the observer lead to an underestimation of the real abundance, whereas more inclined ones overestimate it. In the case of a mixture of fields with different inclinations, these effects are likely to partly cancel each other out, making the role of the magnetic field even less important. Finally, we derive a simple model that can be used to determine the suitability of a spectral line when we wish to avoid the bias introduced by the neglect of the magnetic field.
mb:Ms Screening Revisited for Large Events

Abstract Event screening of large‐magnitude events ( M w ≳5) based on m b : M s is revisited to account for the effect of the source corner frequency relative to the fixed frequencies of the long‐period M s and short‐period m b . For large events this source effect increases the slope of m b : M s relative to the 1:1 value expected for small events. The effect is demonstrated in the large earthquake m b : M s population and in the behavior of large theoretical explosions that are consistent with the more limited explosion population. The behavior is used to create a more conservative screening criterion that ensures large explosions are not inadvertently screened out by m b : M s , while not appreciably decreasing the number of screened earthquakes. This change also makes the variance of the earthquake and explosion populations more equal, which is of utility in statistical analysis. A slight trend in the explosion population and a case study of two large U.S. underground nuclear tests provide support for adopting a more conservative approach.
On a matrix method for the study of small perturbations in galaxies

A matrix method is formulated in a Lagrangian representation for the solution of the characteristic value problem governing modes of oscillation and instability in a collisionless stellar system. The underlying perturbation equations govern the Lagrangian displacement of a star in the six-dimensional phase space. This matrix method has a basis in a variational principle. The method is formulated here for modes with a discrete spectrum of frequencies, and it is developed in detail for radial oscillations of a spherical system with a finite radius. A set of basis vectors suitable for the representation of the Lagrangian displacement in this case is derived from solutions of the Lagrangian perturbation equations for radial perturbations in a homogeneous sphere. The basis vectors are made divergence free in the six-dimensional phase space in accordance with the requirement of Liouville's theorem that the flow of the system in the phase space must be incompressible. The basis vectors are made orthogonal with respect to a properly constructed set of adjoint vectors with the aid of a Gram-Schmidt procedure. Some basis vectors are null vectors in the sense that their inner products with their own adjoint vectors vanish. The characteristic frequencies of the lowest radial modes are calculated in several approximations for the stellar-dynamical counterparts of gaseous polytropes, which span a considerable range of central concentrations. The present formulation of the matrix method can be generalized, for example, for non-radial modes in spherical systems and for modes in axisymmetric systems, with the aid of other, suitably constructed sets of basis vectors.
Man in the public sector

This paper addresses the question of how to model government behavior. The central thought is that in principle the same behavioral model should apply to the behavior of individuals in the private sector as well as the public sector. The paper starts, therefore, with an outline of the contours of a general model of individual behavior. Use is thereby made of the so-called interest function approach that I developed inOn the Interaction Between State and Private Sector (Amsterdam, North-Holland, 1983) and which is somewhat further elaborated in this paper. The model is subsequently applied to the behavior of the individuals that make up the government organization, bureaucrats and politicians. The potential importance of the approach is indicated by a short survey of the theoretical and empirical results obtained with it so far.
Self-magnetization of the early Solar System matter

The remnant magnetization of chondrite type meteorite matter indicates the existence of 10−5–10−3 T magnetic fields in the early Solar System accretion disk. Taking into account parameter regimes being typical for this evolutionary stage of Sun and planets we consider the protosolar disk matter as partially ionized dusty plasma consisting of massive charged dust grains, neutral gas, electrons and ions. Results of systematic multifluid neutral gas–plasma–dust simulations show that shear flow driven collisional interactions yield a self-magnetization of the early Solar System matter which is able to explain the measured remnant magnetization of meteorite material.
Wetting Hysteresis at the Molecular Scale

The motion of a fluid-fluid-solid contact line on a rough surface is known to display hysteresis in the contact angle versus velocity relationship. To understand the phenomenon at the microscopic level, we have conducted molecular dynamics simulations of a Wilhelmy plate experiment in which a solid surface is dipped into a liquid bath, and the force-velocity characteristics are measured. We observe a systematic variation of force and contact angle with velocity, which is single valued for the case of an atomically smooth solid surface. If the surface is microscopically rough, however, we find a very irregular local interface shape, and an open hysteresis loop corresponding to a history-dependent force.
Suicide attempts and nonsuicidal self-injury in the treatment of resistant depression in adolescents: findings from the TORDIA study.

Objective To evaluate the clinical and prognostic significance of suicide attempts (SAs) and nonsuicidal self-injury (NSSI) in adolescents with treatment-resistant depression. Method Depressed adolescents who did not improve with an adequate SSRI trial ( N = 334) were randomized to a medication switch (SSRI or venlafaxine), with or without cognitive-behavioral therapy. NSSI and SAs were assessed at baseline and throughout the 24-week treatment period. Results Of the youths, 47.4% reported a history of self-injurious behavior at baseline: 23.9% NSSI alone, 14% NSSI+SAs, and 9.5% SAs alone. The 24-week incidence rates of SAs and NSSI were 7% and 11%, respectively; these rates were highest among youths with NSSI+SAs at baseline. NSSI history predicted both incident SAs (hazard ratio [HR]= 5.28, 95% confidence interval [CI] = 1.80–15.47, z = 3.04, p = .002) and incident NSSI (HR = 7.31, z = 4.19, 95% CI=2.88–18.54, p z = 2.29, p = .13). In the most parsimonious model predicting time to incident SAs, baseline NSSI history and hopelessness were significant predictors, adjusting for treatment effects. Parallel analyses predicting time to incident NSSI through week 24 identified baseline NSSI history and physical and/or sexual abuse history as significant predictors. Conclusions NSSI is a common problem among youths with treatment-resistant depression and is a significant predictor of future SAs and NSSI, underscoring the critical need for strategies that target the prevention of both NSSI and suicidal behavior. Clinical Trial Registration Information—Treatment of SSRI-Resistant Depression in Adolescents (TORDIA). URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00018902.
Tandem catalysis: generating multiple contiguous carbon-carbon bonds through a ruthenium-catalyzed ring-closing metathesis/Kharasch addition.

Tandem catalysis can offer unique and powerful strategies for converting simple starting materials into more complex products in a single reaction vessel while generating less waste and minimizing handling. In this regard, Grubbs' ruthenium alkylidene (Cy3P)2Cl2RuCHPh is shown to catalyze two mechanistically distinct transformations to offer a unique protocol that effects multiple bond changes in a single operation. A tandem ruthenium-catalyzed olefin ring-closing metathesis (RCM)/Kharasch addition allows for the facile preparation of bicyclic [3.3.0], [4.3.0], and [5.3.0] ring systems in one step from the appropriately functionalized acyclic precursors. For substrates where the intramolecular Kharasch addition fails, an intermolecular Kharasch addition is possible. By combining the intra- and intermolecular Kharasch additions with RCM, three new contiguous carbon−carbon bonds with multiple stereocenters can be generated by the ruthenium catalyst in a controlled fashion in one operation through two mechan...
Simulation of APLE photoinjector

Abstract This paper presents the PARMELA simulations of the photoinjector for the average power laser experiment. We modified the PARMELA code to include the misalignment of magnetic field coils. The effects on beam emittance from the combination of the misaligned coil and correction REC magnets are studied. The normalized four times rms emittance is calculated as 80π mm mrad at the end of photoinjector with the correction magnets.
The theory and simulation of relativistic jet formation: towards a unified model for micro- and macroquasars

Abstract I review recent progress in the theory of relativistic jet production, with special emphasis on unifying black hole sources of stellar and supermassive size. Observations of both classes of objects, as well as theoretical considerations, indicate that such jets may be launched with a spine/sheath flow structure, having a much higher Lorentz factor (∼50) near the axis and a lower speed (Γ∼10 or so) away from the axis. It has become clear that one can no longer consider models of accretion flows without also considering the production of a jet by that flow. Furthermore, the rotation rate of the black hole also must be taken into account. It provides a third parameter that should break the mass/accretion rate degeneracy and perhaps explain why some sources are radio-loud and some radio-quiet. Slow jet acceleration and collimation is expected theoretically, and can explain some of the observed features of AGN jet sources. Finally, relativistic jets launched by MHD/ED processes are Poynting flux dominated by nature, and are potentially unstable if there is significant entrainment of thermal material.
Thermonuclear Burning on the Accreting X-Ray Pulsar GRO J1744–28

We investigate the thermal stability of nuclear burning on the accreting X-ray pulsar GRO J1744-28. The neutron star's dipolar magnetic field is 3 × 1011 G if persistent spin-up implies that the magnetospheric radius is less than the corotation radius. Bildsten earlier noted that magnetic fields this weak might not quench the vigorous convection sometimes associated with thermonuclear instabilities, so that a convective burning front can propagate around the star in a few seconds and rapidly release the accumulated nuclear energy. After inferring the properties of the neutron star, we study the thermal stability of hydrogen/helium burning and show that thermonuclear instabilities are unlikely causes of the hourly bursts seen at very high accretion rates. Then we discuss how the stability of the thermonuclear burning depends on both the global accretion rate and the neutron star's magnetic field strength. If the accreted matter spreads over the star prior to ignition, then the burning will become unstable when the accretion rate is below 6 × 10-9 M☉ yr-1. We emphasize that the appearance of the instability (i.e., whether it looks like a type I X-ray burst or a flare lasting a few minutes) will yield crucial information on the neutron star's surface magnetic field and the role of magnetic fields in convection. We suggest that a thermal instability in the accretion disk is the origin of the long (~300 days) outburst and that the recurrence time of these outbursts is more than 50 yr. We also discuss the nature of the binary and point out that a velocity measurement of the stellar companion (most likely a Roche lobe filling giant with mK 17) will constrain the neutron star mass. This is of interest in this binary, where the inferred low mass of the companion implies that 0.5 M☉ of transfer occurred.
Vertical Integration and International Predation

This paper investigates the interrelationship between a firm's incentive to engage in international predatory pricing and its domestic vertical industry ties in the context of the deep-pockct theory of predation. The deep pocket stems from a vertically integrated firm's ability to shift funds between its upstream and downstream divisions. enabling it to prey on vertically unintegrated upstream competitors. Vertical integration is shown to function as a cause of and a deterrent to foreign predatory behavior.
A fully nonlinear version of the Yamabe problem and a Harnack type inequality

Abstract We present some results on a fully nonlinear version of the Yamabe problem and a Harnack type inequality for general conformally invariant fully nonlinear second order elliptic equations. To cite this article: A. Li, Y.Y. Li, C. R. Acad. Sci. Paris, Ser. I 336 (2003).
Salivary gland tumors

Abstract One hundred twenty-three cases of salivary gland tumors treated at Grace-New Haven Community Hospital from 1922 to 1952 have been reviewed, and the findings are as follows. 1. 1. The parotid gland was the most frequent tumor site. 2. 2. Malignant and recurrent tumors were found most often in the parotid gland. 3. 3. All biopsied tumors recurred, with three exceptions. 4. 4. The tumor-free survival period of surgically treated recurrent tumors was low. 5. 5. Treatment was generally by surgery. X-ray therapy sometimes was used after surgery, but it was seldom used alone. 6. 6. A small group of patients with histologic benign tumors presented a problem from the point of therapy because of repeated recurrence. 7. 7. Standardization of histologic criteria would simplify and contribute much in comparative studies of these tumors.
The Special Library on Campus: A Model for Library Orientations Aimed at Academic Administration, Faculty, and Support Staff

Abstract A library and media center orientation program was developed for administrators, faculty, and support staff after examining their information seeking behaviors, prior research, and demographics of this group. The goal of the orientation was to promote the library's and media center's services and resources; to encourage this user group to make use of them; and to teach the basic skills needed to address their information needs. This article includes a literature review; explanation of the processes involved in creating a library orientation program for this group; and discussion including ideas and thoughts as to where further research about this user group or library orientation programs might be beneficial.
Examples of different minimal diffeomorphisms giving the same C*-algebras

We give examples of minimal diffeomorphisms of compact connected manifolds which are not topologically orbit equivalent, but whose transformation group C*-algebras are isomorphic. The examples show that the following properties of a minimal diffeomorphism are not invariants of the transformation group C*-algebra: having topologically quasidiscrete spectrum; the action on singular cohomology (when the manifolds are diffeomorphic); the homotopy type of the manifold (when the manifolds have the same dimension); and the dimension of the manifold. These examples also give examples of nonconjugate isomorphic Cartan subalgebras, and of nonisomorphic Cartan subalgebras, of simple separable nuclear unital C*-algebras with tracial rank zero and satisfying the Universal Coefficient Theorem.
The problem of measuring the absolute yield of 14-MeV neutrons by means of an alpha counter

Abstract The assumptions used to derive the total neutron yield per detected alpha particle (from the D-T reaction) which were derived in an earlier report are re-examined in the light of additional experimental information. It is concluded that, for an alpha counter at 90° to the incident beam direction, the assumptions introduce practically no difficulties. Therefore, for precise monitoring in the absence of certain target information, it is recommended that this configuration be used. For counters at angles different from 90°, non-uniformity of target loading contributes the most serious error to the computed yield.
Deriving Empirical Definitions of Spatial Labor Markets: The Roles of Competing versus Complementary Growth

If economic growth elsewhere raises an individual’s earning prospects relative to his present location, then the individual will move. However, if the individual can exploit economic growth elsewhere by commuting, he will not need to move to gain from the expansion. County-level data from eight states in the Midwest over the period 1969–1994 are used to show that local county population responds positively to own-county economic growth, economic growth in the adjacent county, and economic growth two counties away. The magnitude of the effect decreases as distance from the county increases, and turns negative beyond a three county radius.
Cu-catalyzed aerobic oxidative three-component coupling route to N-sulfonyl amidines via an ynamine intermediate.

Cu-catalyzed aerobic oxidative three-component coupling of a terminal alkyne, secondary amine, and sulfonamide enables efficient synthesis of amidines. The use of Cu(OTf)2 (5 mol %) produces amidines selectively without Glaser–Hay alkyne homocoupling products. Preliminary studies suggest that the reaction pathway involves initial oxidative coupling of the terminal alkyne with the secondary amine, followed by hydroamidation of the ynamine intermediate with the sulfonamide.
Arquitectura y virtualidad: Hacia una nueva condición material

Resumen es: La naturaleza meramente formal de buena parte de la llamada produccion arquitectonica digital la ha alejado de otras discusiones, muchas de ellas central...
Acquiring Knowledge From Encyclopedic Texts

A computational model for the acquisition of knowledge from encyclopedic texts is described. The model has been implemented in a program, called SNOWY, that reads unedited texts from The World Book Encyclopedia, and acquires new concepts and conceptual relations about topics dealing with the dietary habits of animals, their classifications and habitats. The program is also able to answer an ample set of questions about the knowledge that it has acquired. This paper describes the essential components of this model, namely semantic interpretation, inferences and representation, and ends with an evaluation of the performance of the program, a sample of the questions that it is able to answer, and its relation to other programs of similar nature.
The Mode-separated Pulse Profiles of Pulsar Radio Emission

Two modes of orthogonal polarization are generally observed in the radio emission from pulsars. Essentially all attempts to calculate the average profiles of the individual modes have assumed that the modes occur separately. We have presented evidence, however, that the modes occur simultaneously. Therefore, we believe that "mode-separated" pulse profiles that have been published to date reveal little about the polarization properties of the individual modes. Calculating mode-separated pulse profiles for superposed orthogonal modes is complicated by the unknown polarization properties of the individual modes. However, the simplest model of pulsar radio emission that can explain the wide variety in the emission's polarization is one in which the individual modes are completely polarized. We argue that the orthogonal modes in PSR B0525+21 and PSR B2020+28 are highly polarized and use our simple model to compute the average profiles of their orthogonal modes. For both pulsars, the total intensity of the two mode profiles resembles the overall pulse profile, and each profile is highly linearly polarized.
Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets

The spins of ten stellar black holes have been measured using the continuum-fitting method. These black holes are located in two distinct classes of X-ray binary systems, one that is persistently X-ray bright and another that is transient. Both the persistent and transient black holes remain for long periods in a state where their spectra are dominated by a thermal accretion disk component. The spin of a black hole of known mass and distance can be measured by fitting this thermal continuum spectrum to the thin-disk model of Novikov and Thorne; the key fit parameter is the radius of the inner edge of the black hole’s accretion disk. Strong observational and theoretical evidence links the inner-disk radius to the radius of the innermost stable circular orbit, which is trivially related to the dimensionless spin parameter a ∗ of the black hole (|a ∗|<1). The ten spins that have so far been measured by this continuum-fitting method range widely from a ∗≈0 to a ∗>0.95. The robustness of the method is demonstrated by the dozens or hundreds of independent and consistent measurements of spin that have been obtained for several black holes, and through careful consideration of many sources of systematic error. Among the results discussed is a dichotomy between the transient and persistent black holes; the latter have higher spins and larger masses. Also discussed is recently discovered evidence in the transient sources for a correlation between the power of ballistic jets and black hole spin.
Timing of retrogressive thaw slump initiation in the Noatak Basin, northwest Alaska, USA

In the North American low arctic, increased retrogressive thaw slump frequency and headwall retreat rates have been linked with climate warming trends since the midtwentieth century, but specific weather drivers of slump initiation timing are less clear. We examined relationships among retrogressive thaw slump initiation and annual air temperature, precipitation, and snow cover using time series of satellite imagery and weather station data in northwest Alaska. Synthetic aperture RADAR and optical imagery were used to examine retrogressive thaw slump initiation between 1997 and 2010. Over 80% of the slump features examined in this study first appear within a 13 month span from late June 2004 to July 2005. Remote weather station data show that 2004 and 2005 are among several years exhibiting above average thawing indices and average summer temperatures between 1992 and 2011. However, 2004 is distinct from the rest of the record, with unusually warm temperatures primarily occurring early in the thaw season between April and early June, and including two intense precipitation events in May. Regional weather reported by the NOAA National Weather Service also reflects these local findings. Snowmelt timing in 2004 corresponded with warmer air temperatures and precipitation between April and May, exposing the ground surface more than 2 weeks earlier than average for 2001–2012 within the Noatak Basin. Future rates of thaw slump initiation may be linked with changing trends in the timing of weather, in addition to general climate warming.
A Complete Assessment of the Emissions Performance of Ethanol Blends and Iso-Butanol Blends from a Fleet of Nine PFI and GDI Vehicles

Author(s): Karavalakis, George; Short, Daniel; Vu, Diep; Russell, Robert; Asa-Awuku, Akua; Durbin, Thomas
Rotor wake characteristics relevant to rotor-stator interaction noise generation

Mean and turbulence wake properties at three axial locations behind the rotor of an aerodynamically loaded 1.2 pressure ratio fan were measured using a stationary cross film anemometer in an anechoic wind tunnel. Wake characteristics at four radial immersions across the duct at four different fan speeds were determined utilizing a signal enhancement technique. The shapes of the waveforms of the mean rotor relative and mean upwash velocities were shown to change significantly across the span of the blades. In addition, an increase in fan rotational speed caused an increase in the maximum wake turbulence intensity levels near the hub and tip. Spectral analysis was used to describe the complex nature of the rotor wake.
Using Astrometry to Deblend Microlensing Events

We discuss the prospect of deblending microlensing events by observing astrometric shifts of the lensed stars. Since microlensing searches are generally performed in very crowded fields, it is expected that stars will be confusion limited rather than limited by photon statistics. By performing simulations of events in crowded fields, we find that if we assume a dark lens and that the lensed star obeys a power-law luminosity function, n(L) ∝ L-β, over half the simulated events show a measurable astrometric shift. Our simulations included 20,000 stars in a 256 × 256 Nyquist-sampled CCD frame. For β = 2, we found that 58% of the events were significantly blended (F*/Ftot ≤ 0.9), and of those, 73% had a large astrometric shift (≥0.5 pixels). Likewise, for β = 3, we found that 85% of the events were significantly blended and that 85% of those had large shifts. Moreover, since the shift may be used to determine the true position of a source star with respect to the observed point-spread function, a high-resolution follow-up survey may be used to identify the source star and determine the blending fraction directly.
The direct observation of atomic surface structure and inclined planar defects in Au(111) films

Abstract With a high resolution electron microscope it is possible to image directly the atomic surface lattice of vapor-deposited Au(111) films. The contrast of the surface atoms can be either black or white relative to the background which is characteristic of close-packed planes of atoms in the stacking sequence ABCABC…. An analysis of these images was performed using multislice dynamical diffraction computations of 256 × 256 = 65 536 reciprocal space points and subsequent image simulations. The effects of top and bottom surface roughness, different termination layers and the contrast compared with single-atom imaging are considered. The identification of atomic structure detail at incoherent double-position boundaries in these (111) films was also achieved. Surface layer terminations, variations in the choice of every third matching plane and the possibility that twinning planes produce boundaries with jogs were investigated. Multislice computer programs were designed to calculate the diffraction effects from these inclined boundaries using two-dimensional fast Fourier transform and shift techniques of the projected potential. This is the first time that inclined planar defects have been analyzed in this manner.
The Phase Coherence of Light from Extragalactic Sources: Direct Evidence against First-Order Planck-Scale Fluctuations in Time and Space

We present a method of directly testing whether time continues to have its usual meaning on scales of ≤tP = (G/c5)1/2 ≈ 5.4 × 10-44 s, the Planck time. According to quantum gravity, the time t of an event cannot be determined more accurately than a standard deviation of the form σt/t = a0(tP/t)α, where a0 and α are positive constants ~1; likewise, distances are subject to an ultimate uncertainty cσt, where c is the speed of light. As a consequence, the period and wavelength of light cannot be specified precisely; rather, they are independently subject to the same intrinsic limitations in our knowledge of time and space, so that even the most monochromatic plane wave must in reality be a superposition of waves with varying ω and , each having a different phase velocity ω/k. For the entire accessible range of the electromagnetic spectrum this effect is extremely small, but it can cumulatively lead to a complete loss of phase information if the emitted radiation propagated a sufficiently large distance. Since, at optical frequencies, the phase coherence of light from a distant point source is a necessary condition for the presence of diffraction patterns when the source is viewed through a telescope, such observations offer by far the most sensitive and uncontroversial test. We show that the Hubble Space Telescope detection of Airy rings from the active galaxy PKS 1413+135, located at a distance of 1.2 Gpc, excludes all first-order (α = 1) quantum gravity fluctuations with an amplitude a0 > 0.003. The same result may be used to deduce that the speed of light in vacuo is exact to a few parts in 1032.
Spherical gauge fields

Abstract We introduce the spherical field formalism for free gauge fields. We discuss the structure of the spherical Hamiltonian for both general covariant gauge and radial gauge and point out several new features not present in the scalar field case. We then use the evolution equations to compute gauge-field and field-strength correlators.
p63 and p73 transcriptionally regulate genes involved in DNA repair.

The p53 family activates many of the same genes in response to DNA damage. Because p63 and p73 have structural differences from p53 and play distinct biological functions in development and metastasis, it is likely that they activate a unique transcriptional network. Therefore, we performed a genome-wide analysis using cells lacking the p53 family members after treatment with DNA damage. We identified over 100 genes involved in multiple pathways that were uniquely regulated by p63 or p73, and not p53. Further validation indicated that BRCA2, Rad51, and mre11 are direct transcriptional targets of p63 and p73. Additionally, cells deficient for p63 and p73 are impaired in DNA repair and p63+/−;p73+/− mice develop mammary tumors suggesting a novel mechanism whereby p63 and p73 suppress tumorigenesis.
Economic and Quality Of Life Impact of Dry Eye Symptoms in Women with Sjögren’s Syndrome

Sjogren’s syndrome is one of the leading causes of dry eye syndromes in the world. The purpose of this investigation was to determine the economic and quality of life impact of dry eye symptoms in women with this autoimmune disorder.
Studies of silicon–nitrogen ring formation from tetrachlorodisilanes†

The addition of n equiv of MesNHLi (n = 1, 2, 3, 4) and m equiv of 12-crown-4 (m = 0.1, 1, 2, 3, 4) to (RsiCl2)2 (R = Mesityl; t-Butyl) in THF at −78°C resulted in higher yields and improved selectivities of cyclodisilazanes and azadisilacyclopropanes. The reaction of 2 equiv of MesNDLi with (MesSiCl2)2 (I) yielded cis-2-chloro-1,2,3,4-tetramestylcyclodisilazane (2a) with 95% SiH deuteration. 2a was quantitatively chlorinated with retention of stereochemistry by N-chlorosuccinimide to give the cis dichlorocyclodisilazane (3). Variable-temperature 1H NMR studies from −70°C to 25°C in d8-THF were performed on 1, 2a, 2b, and 3. 1 exhibited little variation throughout the temperature range, whereas 2a, 2b, and 3 showed several rotational isomers. trans-2,3-Bis(mesitylamino)-1,2,3-trimesitylazadisilacyclopropane was shown to isomerize to the cis isomer in the presence of n-BuLi or MesNHLi. The molecular structures of 1 and 3 were determined by X-ray crystallography. Compound 1 crystallized in the monoclinic space group P21/c, with cell parameters a = 16.599(2) A b = 14.633(2) A, c = 16.945(2) A, β = 92.044(13)°, V = 4113.1(8) A3, Z = 8, d (calcd) = 1.409 g/cm3, and R = 6.88%. Compound 3 ° C6H6 crystallized in the orthorhombic space group Pbca, with cell parameters a = 17.906(4) A, b = 13.918(3) A, c = 31.700(6) A, V = 7900(3) A3, Z = 8, d (calcd) = 1.194 g/cm3, and R = 7.52%.
GSE Impact on Rural Mortgage Markets

Abstract This paper examines the spatial integration of the rural mortgage market with the larger national market. It does this by asking three key questions. First, does a jumbo/conforming loan rate differential exist in the rural mortgage market? Second, to what extent are rural and urban mortgage markets integrated? Third, what risk factors contribute to changes in rural and urban mortgage spreads? The results confirm that the rural and urban conforming markets are closely tied, while rural and urban jumbo rural markets are less closely tied. We interpret this as evidence that Government-Sponsored Enterprises (GSE) involvement in the rural market provide rural conforming mortgage borrowers, as compared to rural jumbo borrowers, with improved access to credit.
Measuring SWNT Depth in Electroactive Polymer Nanocomposite Films using Electric Force Microscopy

Although a number of hypotheses have been presented to explain the enhanced electromechanical performance observed in electroactive polymer nanocomposite materials, many of the underlying mechanisms responsible for this behavior remain unclear. In this report, electric force microscopy (EFM) is used to investigate the near surface morphology of an electroactive polyimide-based nanocomposite film containing SWNTs in an effort to gain insight into the electrical interactions occurring at the polymer-electrode interface. As a means of measuring the proximity of SWNTs to this interface, the depths of SWNTs buried beneath a processing-induced polymer skin layer are determined using EFM measurements derived from a sample standard. In this way, evaluation of the ability for embedded SWNT structures to behave as extensions of surface electrodes is possible, a scenario that could potentially reduce the applied field required to elicit electromechanical actuation.
Scattering and thermodynamics of fractionally-charged supersymmetric solitons

Abstract We show that there are solitons with fractional fermion number in integrable N = 2 supersymmetric models. We obtain the soliton S -matrix for the minimal, N = 2 supersymmetric theory perturbed in the least relevant chiral primary field, the φ (1,3) superfield. The perturbed theory has a nice Landau-Ginzburg description with a Chebyshev polynomial superpotential. We show that the S -matrix is a tensor product of an associated ordinary ADE minimal model S -matrix with a supersymmetric part. We calculate the ground-state energy in these theories and in the analogous N = 1 case and SU(2) coset models. In all cases, the ultraviolet limit is in agreement with the conformal field theory.
WHO BENEFITS FROM PENSION ENHANCEMENTS

During the late 1990s public pension funds across the United States accrued large actuarial surpluses. The seemingly flush conditions of the pension funds led legislators in most states to substantially improve retirement benefits for public workers, including teachers. In this study we examine the benefit enhancements to the teacher pension system in Missouri. The enhancements resulted in large windfall gains for teachers who were close to retirement when the legislation was enacted. By contrast, novice teachers, and teachers who had not yet entered the labor force, were made worse off. The reason is that front-end contribution rates have been raised for current teachers to offset past liabilities accrued from the enhancements. Total teacher retirement compensation, net of contribution costs, is lower for young teachers today as a result of the enhancement legislation. Given sharp increases in pension costs in other states, this finding may generalize to young teachers in many other plans.