cssi/SciSciGPT-SciSciNet huggingface dataset:
A dynamic model of Venus's gravity field

Unlike Earth, long wavelength gravity anomalies and topography correlate well on Venus. Venus's admittance curve from spherical harmonic degree 2 to 18 is inconsistent with either Airy or Pratt isostasy, but is consistent with dynamic support from mantle convection. A model using whole mantle flow and a high viscosity near surface layer overlying a constant viscosity mantle reproduces this admittance curve. On Earth, the effective viscosity deduced from geoid modeling increases by a factor of 300 from the asthenosphere to the lower mantle. These viscosity estimates may be biased by the neglect of lateral variations in mantle viscosity associated with hot plumes and cold subducted slabs. The different effective viscosity profiles for Earth and Venus may reflect their convective styles, with tectonism and mantle heat transport dominated by hot plumes on Venus and by subducted slabs on Earth. Convection at degree 2 appears much stronger on Earth than on Venus. A degree 2 convective structure may be unstable on Venus, but may have been stabilized on Earth by the insulating effects of the Pangean supercontinental assemblage.
Harmonic map heat flow with rough boundary data

Abstract. Let B1 be the unit open disk in R2 and M be a closed Riemannian manifold. In this note, we first prove the uniqueness for weak solutions of the harmonic map heat flow in H1([0, T ]×B1,M) whose energy is non-increasing in time, given initial data u0 ∈ H(B1,M) and boundary data γ = u0|∂B1 . Previously, this uniqueness result was obtained by Riviere (when M is the round sphere and the energy of initial data is small) and Freire (when M is an arbitrary closed Riemannian manifold), given that u0 ∈ H(B1,M) and γ = u0|∂B1 ∈ H (∂B1). The point of our uniqueness result is that no boundary regularity assumption is needed. Second, we prove the exponential convergence of the harmonic map heat flow, assuming that energy is small at all times.
Is there methane on Mars

Abstract There have been several reports of methane on Mars at the 10–60 ppbv level. Most suggest that methane is both seasonally and latitudinally variable. Here we review why variable methane on Mars is physically and chemically implausible, and then we critically review the published reports. There is no known mechanism for destroying methane chemically on Mars. But if there is one, methane oxidation would deplete the O 2 in Mars’s atmosphere in less than 10,000 years unless balanced by an equally large unknown source of oxidizing power. Physical sequestration does not raise these questions, but adsorption in the regolith or condensation in clathrates ignore competition for adsorption sites or are inconsistent with clathrate stability, respectively. Furthermore, any mechanism that relies on methane’s van der Waals’ attraction is inconsistent with the continued presence of Xe in the atmosphere at the 60 ppbv level. We then use the HITRAN database and transmission calculations to identify and characterize the absorption lines that would be present on Earth or Mars at the wavelengths of the published observations. These reveal strong competing telluric absorption that is most problematic at just those wavelengths where methane’s signature seems most clearly seen from Earth. The competing telluric lines must be removed with models. The best case for martian methane was made for the 12 CH 4 ν 3 R0 and R1 lines seen in blueshift when Mars was approaching Earth in early 2003 (Mumma, M.J., Villanueva, G.L., Novak, R.E., Hewagama, T., Bonev, B.P., DiSanti, M.A., Mandell, A.M., Smith, M.D. [2009]. Science 323, 1041–1045). For these the Doppler shift moves the two martian lines into near coincidence with telluric 13 CH 4 ν 3 R1 and R2 lines that are 10–50× stronger than the inferred martian lines. By contrast, the 12 CH 4 ν 3 R0 and R1 lines when observed in redshift do not contend with telluric 13 CH 4 . For these lines, Mumma et al.’s observations and analyses are consistent with an upper limit on the order of 3 ppbv.
Palladium-catalyzed regio-, diastereo-, and enantioselective benzylic allylation of 2-substituted pyridines.

We report a new method for the highly regio-, diastereo-, and enantioselective palladium-catalyzed allylic alkylation of 2-substituted pyridines that allows for the formation of homoallylic stereocenters containing alkyl, aryl, heteroaryl, and nitrogen substituents. When the reaction is conducted with asymmetric acyclic electrophiles, both linear and branched products may be obtained exclusively by selecting the appropriate regioisomeric starting material and ligand, an example of the “memory effect.” Deuterium-labeling studies reveal that though no such phenomenon occurs with racemic cyclic electrophiles, the chiral ligand employed reacts kinetically faster with the enantiomer of the substrate for which it is “matched” and yet eventually converts all “mismatched” substrate to product.
Computing crossing numbers in quadratic time

We show that for every fixed k\ge 0 there is a quadratic time algorithm that decides whether a given graph has crossing number at most k and, if this is the case, computes a drawing of the graph in the plane with at most k crossings.
Gamma-Ray Burst Environments and Progenitors

Likely progenitors for gamma-ray bursts (GRBs) are the mergers of compact objects or the explosions of massive stars. These two cases have distinctive environments for the GRB afterglow: the compact object explosions occur in the interstellar medium (ISM) and those of massive stars occur in the preburst stellar wind. We calculate the expected afterglow for a burst in a Wolf-Rayet star wind and compare the results with those for constant, interstellar density. The optical afterglow for the wind case is generally expected to decline more steeply than in the constant density case, but this effect may be masked by variations in electron spectral index, and the two cases have the same evolution in the cooling regime. Observations of the concurrent radio and optical/X-ray evolution are especially useful for distinguishing between the two cases. The different rates of decline of the optical and X-ray afterglows of GRB 990123 suggest constant density interaction for this case. We have previously found strong evidence for wind interaction in SN 1998bw/GRB 980425 and here present a wind model for GRB 980519. We thus suggest that there are both wind-type GRB afterglows with massive star progenitors and ISM-type afterglows with compact binary star progenitors. The wind-type bursts are likely to be accompanied by a supernova, but not the ISM type.
Fluctuations in solidification

We present an analytical treatment of (i) the incorporation of thermal noise in the basic continuum models of solidification, (ii) fluctuations about nonequilibrium steady states, and (iii) the amplification of noise near the onset of morphological instability. In (i), we find that the proper Langevin formalism, consistent with both bulk and interfacial equilibrium fluctuations, consists of the usual bulk forces and an extra stochastic force on the interface associated with its local kinetics. At sufficiently large solidification rate, this force affects interfacial fluctuations on scales where they are macroscopically amplified and, thus, becomes relevant. An estimate of this rate is given. In (ii), we extend the Langevin formalism outside of equilibrium to characterize the fluctuations of a stationary and a directionally solidified planar interface in a temperature gradient. Finally, in (iii), we derive an analytic expression for the linear growth of the mean-square amplitude of fluctuations slightly above the onset of morphological instability. The amplitude of the noise is found to be determined by the small parameter ${\mathit{k}}_{\mathit{B}}$${\mathit{T}}_{\mathit{E}}$${\mathit{d}}_{0}^{\mathit{c}}$${\mathit{l}}_{\mathit{T}}$/\ensuremath{\gamma}${\ensuremath{\lambda}}_{\mathit{c}}^{4}$ where \ensuremath{\gamma} is the surface energy, ${\mathit{d}}_{0}^{\mathit{c}}$ is the chemical capillary length, ${\mathit{l}}_{\mathit{T}}$ is the thermal length, and ${\ensuremath{\lambda}}_{\mathit{c}}$ is the critical wavelength. Possible applications to experiment are discussed.
SUPERDENSE MATTER IN STARS

After the nuclear evolution of stellar cores has ended stars rapidly approach their final superdense state. The regime of central densities encompassed in such objets extends from 105 g cm-3 in the lighter white dwarts, to 1015 g cm-3 and more, in canonical neutron stars, or stars indefinitely collapsing toward their Schwarzschild surface. Such dense matter generally consists of a highly degenerate (relativistic) electron sea in which are imbedded conventional nuclei for white dwarfs, and mainly neutrons (or hyperons) with a small proton and electron component in the center of typical neutron stars. The very high momentum of the degenerate electrons so greatly reduces their dielectric polarizability that protons, neutrons and nuclei move in an essentially uniform background sea. Such matter has calculable properties for very dense stars : some white dwarts will be crystalline. The heavier (smaller) ones will have a T3 Debye heat capacity and will consequently cool rapidly as is suggested by observations. The outer regions of a neutron star will also be crystalline since the melting temperature exceeds 3 x 108 °K. Below the solid mantle the neutrons and protons form quantum superfluids with a BCS type gap of order one MeV. The gap is isotropic balow nuclear densities and probably anisotropic above. In the center where fhe density can exceed that within a nucleus the pressure is no longer negligible next to the total relativistic energy density and the nature of such matter is very uncertain. Some fundamental aspects of this regime are discussed.
Synthesis of Glycoconjugate Vaccines against Shigella dysenteriae Type 1.

Syntheses of a hexadecasaccharide and smaller fragments corresponding to one−four repeating units of the O-specific polysaccharide of Shigella dysenteriae type 1 are reported in a reactive aglycon-...
Inflation targeting during asset and commodity price booms

The recent global economic crisis originated in the midst of a commodity price boom that had triggered sharp increases in inflation in many world countries. The crisis also came in the context of a rally in asset prices and large domestic imbalances in the United States. This paper uses a small open-economy dynamic stochastic general equilibrum (DSGE) model to design the correct monetary policy response to a protracted supply shock, and examines how that response would change when many become credit constrained--like in a credit crunch--and when spending of those who can still borrow becomes very sensitive to the interest rates because of overleveraging. Using a version of the model with Kalman learning, the paper also evaluates the implications of a loss of target credibility, showing how rules must be adjusted when the authorities' commitment to the inflation target has been eroded. The appropriate response to future evolutions of the price of oil, including to large downward corrections from the current level, is also evaluated. Copyright 2010, Oxford University Press.
Transformation-based learning in the fast lane

Transformation-based learning has been successfully employed to solve many natural language processing problems. It achieves state-of-the-art performance on many natural language processing tasks and does not overtrain easily. However, it does have a serious drawback: the training time is often intorelably long, especially on the large corpora which are often used in NLP. In this paper, we present a novel and realistic method for speeding up the training time of a transformation-based learner without sacrificing performance. The paper compares and contrasts the training time needed and performance achieved by our modified learner with two other systems: a standard transformation-based learner, and the ICA system (Hepple, 2000). The results of these experiments show that our system is able to achieve a significant improvement in training time while still achieving the same performance as a standard transformation-based learner. This is a valuable contribution to systems and algorithms which utilize transformation-based learning at any part of the execution.
Temperature Dependence of Conductivity and Isotope Effect in the Colossal Magnetoresistance

The diffusion of electrons in a disordered metal, by means of the perturbation approach, is considered in the presence of a magnetic field. It is shown that the multiple backward scattering of electrons on the randomly oriented or distributed magnetic moments of atoms significantly reduces the diffusion of electrons. Thus, in the diffusive but nearly localized electron system localized magnetic moments appear and a transition into the ferromagnetic phase occurs. The isotope effect in T C , the Curie temperature, is obtained, as first observed in La 1-x (Ca,Sr) x MnO 3+y experiments by Zhao and coworkers. Both a relatively weak classical magnetic field (ω c τ 0 < 1, where ω c is the cyclotron frequency, and τ 0 is the elastic collision time) and a molecular field, appearing as result of the spin polarization or spontaneous magnetization in the system, are found to be able to completely suppress the interference effect in the diffusion. It is shown that the giant magnetoresistance is extramely large near the mobility edge. The effect of magnetic field on the magnetic susceptibility is also considered. The application of the results to a layered 2D case is discussed as well.
Halo Stars near the Hydrogen-burning Limit: The M/L Subdwarf Transition*

We present the first far-red spectra of the L subdwarf 2MASS J16262034+3925190 and the late-M/early-L subdwarf 2MASS J16403197+1231068. We confirm the ultracool subdwarf nature of these objects. Like an L4 dwarf, 2M 1626+3925 shows strong K I absorption and is very similar to, but hotter than, the late-L subdwarf 2MASS J05325346+8246465. It is unambiguously an L subdwarf. 2M 1640+1231 is very similar to SSSPM J1444-2019, which has been classified as sdM9 or early sdL. In contrast to the hotter M subdwarfs, L subdwarfs are characterized by not only enhanced hydrides but also strong TiO. Progress in a classification system requires identification of more subdwarfs to map out their variations.
Transition-zone observations of rapid flare events as observed by OSO-8

The rapid dissipation of flare energy has been observed in the transition-zone line of C IV at 1548.2 A using the University of Colorado spectrometer aboard OSO-8. Impulsive brightenings have been resolved with characteristic rise times as low as 3.5s. One event is analyzed in detail, and it is inferred that the electron density is greater than 2 x 10 to the 11th/cu cm at a temperature of 60,000 K, and that the flare energy is deposited at a rate of 2 ergs/cu cm per sec or greater. The temporal behavior of the intensity at the center of the C IV line is consistent with a nonequilibrium ionization of C III through C V. If this event is a result of the multiple tearing mode instability as the primary energy release mechanism, then the observations indicate a preflare magnetic field of about 175 G.
Weight constraints as nested expressions

We compare two recent extensions of the answer set (stable model) semantics of logic programs. One of them, due to Lifschitz, Tang and Turner, allows the bodies and heads of rules to contain nested expressions. The other, due to Niemela and Simons, uses weight constraints. We show that there is a simple, modular translation from the language of weight constraints into the language of nested expressions that preserves the program's answer sets. Nested expressions can be eliminated from the result of this translation in favor of additional atoms. The translation makes it possible to compute answer sets for some programs with weight constraints using satisfiability solvers, and to prove the strong equivalence of programs with weight constraints using the logic of here-and-there.
Post-Shot Radiation Environment Following Low-Yield Shots inside the National Ignition Facility

A detailed model of the Target Bay (TB) at the National Ignition Facility (NIF) has been developed to estimate the post-shot radiation environment inside the facility. The model includes large numb...
The Tchebyshev Transforms of the First and Second Kind

An in-depth study of the Tchebyshev transforms of the first and second kind of a poset is taken. The Tchebyshev transform of the first kind is shown to preserve desirable combinatorial properties, including EL-shellability and nonnegativity of the cd-index. When restricted to Eulerian posets, it corresponds to the Billera, Ehrenborg, and Readdy omega map of oriented matroids. The Tchebyshev transform of the second kind U is a Hopf algebra endomorphism on the space of quasisymmetric functions which, when restricted to Eulerian posets, coincides with Stembridge’s peak enumerator. The complete spectrum of U is determined, generalizing the work of Billera, Hsiao, and van Willigenburg. The type B quasisymmetric function of a poset is introduced and, like Ehrenborg’s classical quasisymmetric function of a poset, it is a comodule morphism with respect to the quasisymmetric functions QSym. Finally, similarities among the omega map, Ehrenborg’s r-signed Birkhoff transform, and the Tchebyshev transforms motivate a general study of chain maps which occur naturally in the setting of combinatorial Hopf algebras.
Bispectral KP solutions and linearization of Calogero-Moser particle systems

Rational and soliton solutions of the KP hierarchy in the subgrassmannianGr1 are studied within the context of finite dimensional dual grassmannians. In the rational case, properties of the tau function, τ, which are equivalent to bispectrality of the associated wave function, ψ, are identified. In particular, it is shown that there exists a bound on the degree of all time, variables in τ if and only if ψ is a rank one bispectral wave function. The action of the bispectral involution, β, in the generic rational case is determined explicitly in terms of dual grassmannian parameters. Using the correspondence between rational solutions, and particle systems, it is demonstrated that β is a linearizing map of the Calogero-Moser particle system and is essentially the map σ introduced by Airault, McKean and Moser in 1977 [2].
Spectroscopy of gauge theories based on exceptional Lie groups

We generate by computer a basis of invariants for the fundamental representations of the exceptional Lie groups E6 and E7, up to degree 18. We discuss the relevance of this calculation for the study of supersymmetric gauge theories, and revisit the self-dual exceptional models. We study the chiral ring of G2 to degree 13, as well as a few classical groups. The homological dimension of a ring is a natural estimator of its complexity and provides a guideline for identifying theories that have a good chance to be amenable to a solution.
Accelerated backpressure algorithm

We develop an Accelerated Back Pressure (ABP) algorithm using Accelerated Dual Descent (ADD), a distributed approximate Newton-like algorithm that only uses local information. Our construction is based on writing the backpressure algorithm as the solution to a network feasibility problem solved via stochastic dual subgradient descent. We apply stochastic ADD in place of the stochastic gradient descent algorithm. We prove that the ABP algorithm guarantees stable queues. Our numerical experiments demonstrate a significant improvement in convergence rate, especially when the packet arrival statistics vary over time.
Structured youth dialogue to empower peacebuilding and leadership

Through structured dialogue during Youth Peacebuilding and Leadership Programs, high school and college students from Cyprus, Iraq, Serbia, Armenian, Azerbaijan, Denmark, the U.K., and the United States developed expressive, relational, intercultural, and analytical skills, plus a sense of personal transformation. Well-facilitated peer dialogue promotes self-awareness, compassion, diverse perspectives on current issues, and capacities for social action. Facilitators structure process and content for sessions, creating a mood of safety and openness, focusing topics for appropriate risk and relevance, reconciliation, and empowerment. Participants practice communication skills essential for shared leadership: listening and speaking effectively, recognizing cross-cultural difference, analyzing issues cooperatively, and making decisions collaboratively.
Unique 11b‐Substituted Indeno[2,1‐c]quinolin‐6‐one Ring System

Abstract A unique 11b‐substituted indeno[2,1‐c]quinolin‐6‐one ring system was prepared in good yield and the structure of the product was unequivocally determined by X‐ray crystallography.
PHYSICAL PROPERTIES OF FOUR SZE-SELECTED GALAXY CLUSTERS IN THE SOUTHERN COSMOLOGY SURVEY

We present the optical and X-ray properties of four clusters recently discovered by the South Pole Telescope (SPT) using the Sunyaev-Zel'dovich effect (SZE). The four clusters are located in one of the common survey areas of the southern sky that is also being targeted by the Atacama Cosmology Telescope (ACT) and imaged by the CTIO Blanco 4 m telescope. Based on publicly available griz optical images and XMM-Newton and ROSAT X-ray observations, we analyze the physical properties of these clusters and obtain photometric redshifts, luminosities, richness, and mass estimates. Each cluster contains a central elliptical whose luminosity is consistent with SDSS cluster studies. Our mass estimates are well above the nominal detection limit of the SPT and ACT; the new SZE clusters are very likely massive systems with M 5 × 1014 M ☉.
New constraints on SO(10) model building from string theory

Abstract A recent analysis of the methods by which higher-level gauge symmetries are realized in string theory has made it possible to systematically obtain new constraints on string GUT model-building. In this paper, we perform such a study for the case of SO(10) free-field string GUT models, and find a number of significant new results. First, we show that within the conventional string models using the so-called “diagonal” embeddings, all representations larger than the 16 must always transform as singlets under all gauge symmetries beyond SO(10). This includes the 45 and 54 representations, and holds regardless of the affine level at which SO(10) is realized. Furthermore, we show that such constructions can never give rise to the 120, 126, or 144 representations of SO(10) — again regardless of the affine level. We also perform a similar analysis for E6, and find that the adjoint 78 representation must always transform as a singlet under all gauge symmetries beyond E6; moreover, all representations beyond the 78 representation are prohibited. Taken together, these results thus severely limit the types of phenomenologically realistic fieldtheoretic SO(10) and E6 models that can be obtained using such string constructions. Finally, we also explore the possibility of using non-diagonal free-field embeddings, and show that in the SO(10) case such embeddings may have improved phenomenological prospects.
Observations of Solar Flare Doppler Shift Oscillations with the Bragg Crystal Spectrometer on Yohkoh

Oscillations in solar coronal loops appear to be a common phenomenon. Transverse and longitudinal oscillations have been observed with both the Transition Region and Coronal Explorer and Extreme ultraviolet Imaging Telescope imaging experiments. Damped Doppler shift oscillations have been observed in emission lines from ions formed at flare temperatures with the Solar Ultraviolet Measurements of Emitted Radiation spectrometer. These observations provide valuable diagnostic information on coronal conditions and may help refine our understanding of coronal heating mechanisms. I have initiated a study of the time dependence of Doppler shifts measured during flares with the Bragg Crystal Spectrometer (BCS) on Yohkoh. This Letter reports the detection of oscillatory behavior in Doppler shifts measured as a function of time in the emission lines of S XV and Ca XIX. For some flares, both lines exhibit damped Doppler shift oscillations with amplitudes of a few kilometers per second and periods and decay times of a few minutes. The observations appear to be consistent with transverse oscillations. Because the BCS observed continuously for almost an entire solar cycle, it provides numerous flare data sets, which should permit an excellent characterization of the average properties of the oscillations.
STUDYING CLUSTERS WITH PLANCK

We use mock Sunyaev-Zeldovich effect maps to investigate how well the Planck mission might find and characterize clusters of galaxies. We discuss different combinations of frequency maps and different methods for identifying cluster candidates. For the simplest methods, the catalogs are not complete, even for relatively high mass thresholds, but the all-sky nature of the mission ensures a large sample of massive, high-z clusters that will be ideal for many studies. We make a preliminary attempt to identify the X-ray, optical, and weak-lensing properties of the Planck sample.
Platinum-Catalyzed Intramolecular Alkylation of Indoles with Unactivated Olefins

Reaction of 1-methy-2-(4-pentenyl)indole (1) with a catalytic amount of PtCl2 (2 mol %) in dioxane that contained a trace of HCl (5 mol %) at 60 °C for 24 h led to the isolation of 4,9-dimethyl-2,3,4,9-tetrahydro-1H-carbazole (2) in 92% yield. Platinum-catalyzed cyclization of 2-(4-pentenyl)indoles tolerated substitution at each position of the 4-pentenyl chain. Furthermore, the protocol was applicable to the synthesis of tetrahydro-β-carbolinones and was effective for cyclization of unprotected indoles. 2-(3-Butenyl)indoles underwent platinum-catalyzed cyclization with exclusive 6-endo-trig regioselectivity. Mechanistic studies established a mechanism for the platinum-catalyzed cyclization of 2-alkenyl indoles involving nucleophilic attack of the indole on a platinum-complexed olefin.
Turán's theorem inverted

In this note we complete an investigation started by Erdos in 1963 that aims to find the strongest possible conclusion from the hypothesis of Turan's theorem in extremal graph theory. Let K"r^+(s"1,...,s"r) be the complete r-partite graph with parts of sizes s"1>=2,s"2,...,s"r with an edge added to the first part. Letting t"r(n) be the number of edges of the r-partite Turan graph of order n, we prove that: For all r>=2 and all sufficiently small c>0, every graph of sufficiently large order n with t"r(n)+1 edges contains a K"r^+(@[email protected]?,...,@[email protected]?,@?n^1^-^[email protected]?). We also give a corresponding stability theorem and two supporting results of wider scope.
Seismic data mapping and reconstruction

Seismic data mapping uses data at source and receiver locations one actually has to create or simulate data at the locations one desires to have. The process is similar to seismic migration, though less demanding in that only data relatively near to the desired output point need be employed. Basic data mapping adjusts phase and amplitude of the data to conform to the geometry at the output location under the assumption that reflectivity does not change with angle of incidence. Full seismic data reconstruction goes beyond basic data mapping by also allowing reflection coefficients to change with incident angle. In the straight-raypath approximation, both data mapping and full data reconstruction are Kirchhoff-like operations of small integration aperture, with data mapping the simpler of the two. Operating on moveout-corrected data, they are (up to a point) velocity independent. The operators can map or continue data from one offset to another [dip moveout (DMO) being a special case of data mapping] or from one source or receiver location to another. Both 2-D and 3-D versions of the operators can be constructed. The 2-D mapping and reconstruction operators apply when input and output offset azimuths are aligned. The 3-D operators are equivalent, at least in principle, to two passes of the corresponding 2-D operators: the first pass a DMO to zero offset, the second an inverse DMO to the desired location. Potential uses for data mapping and reconstruction include filling in missing data, regularizing a data set, consolidating to a smaller data set, removing acquisition footprints, and so on.
Geminal Alkene–Alkyne Cross Metathesis Using a Relay Strategy

A relay strategy was employed to achieve an intermolecular ene–yne metathesis between 1,1-disubstituted alkenes and alkynes. The relay serves to activate an unreactive alkene which will not participate in ene-yne metathesis. The new relay cross ene–yne metathesis gives rise to 1,1,3-trisubstituted-1,3-dienes previously inaccessible by direct ene–yne metathesis methods.
Band anticrossing in highly mismatched group II-VI semiconductor alloys

We have successfully synthesized highly mismatched Cd1-yMnyOxTe1-x alloys by high-dose implantation of O ions into Cd1-yMnyTe crystals. In crystals with y > 0.02, incorporation of O causes a large decrease in the bandgap. The bandgap reduction increases with y; the largest value observed is 190 meV in O+-implanted Cd0.38Mn0.62Te. The results are consistent with the band anticrossing (BAC) model, which predicts that a repulsive interaction between localized states of O located above the conduction-band edge and the extended states of the conduction band causes the bandgap reduction. A best fit of the measured bandgap energies of the O-ion-synthesized Cd1-yMnyOxTe1-x alloys using the BAC model for y < 0.55 suggests an activation efficiency of only ∼5% for implanted O in Cd1-yMnyTe.
Amino Alcohols as Ligands for Nickel-Catalyzed Suzuki Reactions of Unactivated Alkyl Halides, Including Secondary Alkyl Chlorides, with Arylboronic Acids

Suzuki cross-coupling reactions of an unprecedented array of unactivated primary and secondary alkyl halides (including challenging alkyl chlorides) can be accomplished through the use of nickel/amino alcohol-based catalysts. Both the nickel precatalyst and the amino alcohols (prolinol or trans-2-aminocyclohexanol) are commercially available and air-stable. In view of the remarkable diversity of amino alcohols that are readily accessible, this discovery may open the door to the rapid development of versatile catalysts for a wide range of cross-coupling processes.
Ultrasound findings of the elbow posterior fat pad in children with radial head subluxation

Background In young children with a non-mobile elbow, it can be difficult to differentiate radial head subluxation (RHS) from elbow fracture by history and examination alone. Data demonstrate that an elevated posterior fat pad (PFP) or lipohemarthrosis (LH) of the PFP on ultrasound is highly sensitive for fracture at the elbow, but it is not known whether these findings are present in children with RHS. Objective To determine if elbow ultrasound findings of the PFP are present in patients with the diagnosis of RHS. Patients and methods This was a prospective study of children presenting to an urban pediatric emergency department diagnosed clinically with RHS. Physicians received a one-hour training session on musculoskeletal ultrasound including the elbow. Prior to performing reduction for RHS, physicians performed a brief, point-of-care elbow ultrasound using a high-frequency linear transducer probe in both longitudinal and transverse views to evaluate for PFP elevation and LH. Successful clinical reduction with spontaneous movement of the injured extremity served as the gold standard for RHS. Clinical telephone follow up was performed to ascertain outcomes. Results 42 patients were enrolled with a mean age of 22.3 (± 11.8) months. The mean time to presentation was 7.0 (± 9.2) hours, and 9/42 (21%) children had a prior history of RHS. The majority of patients (35/42, 83%, 95% confidence interval (CI) 69-92%) had a normal elbow ultrasound. 6/42 (14%, 95% CI 6-28%) patients had an elevated PFP and 2/42 (5%, 95% CI 0.5-17%) had LH. Clinical reduction was successful in 100% of patients, and there were no complications reported on follow-up. Conclusion The majority of children with RHS have a normal PFP on elbow ultrasound, but elevated PFP and LH are possible findings. Reduction maneuvers for RHS should be attempted in the setting of a normal elbow ultrasound when RHS or elbow fracture is uncertain, but with abnormal ultrasound findings, X-rays may be considered.
Continuous combined estrogen/progestin hormone replacement therapy

Women entering menopause should be informed of the benefits and risks of hormone replacement therapy and of the variety of regimens available. One option, a continuous combined regimen of conjugated equine estrogen 0.625 mg and medroxyprogesterone acetate 2.5 mg, maintains the beneficial effects of estrogen on cardiovascular risk factors, although its effects on high-density lipoprotein cholesterol levels are less pronounced than with estrogen alone. The addition of progestin does not affect carbohydrate metabolism except for a slight decline in glucose tolerance. Blood coagulation factors and blood pressure showed no clinically significant changes different from those resulting from unopposed estrogen. Bone mineral density is increased more with the continuous combined regimen than with a cyclical regimen of the same hormones. The incidence of endometrial hyperplasia is substantially less than that observed with unopposed estrogen. The overall frequency of irregular bleeding is lower than with estrogen alone and diminishes with continuation of therapy, whereas the incidence of amenorrhea increases from 52.1% to 75.1% between cycles 2 and 11. Epidemiologic evidence linking any hormonal therapy with breast cancer remains inconsistent, possibly because the risk, if any, is small. The relative risk of breast cancer for the continuous regimen has not been extensively studied in large-scale studies.
Symmetry-aware marginal density estimation

The Rao-Blackwell theorem is utilized to analyze and improve the scalability of inference in large probabilistic models that exhibit symmetries. A novel marginal density estimator is introduced and shown both analytically and empirically to outperform standard estimators by several orders of magnitude. The developed theory and algorithms apply to a broad class of probabilistic models including statistical relational models considered not susceptible to lifted probabilistic inference.
Detecting and Correcting Speech Repairs

Interactive spoken dialog provides many new challenges for spoken language systems. One of the most critical is the prevalence of speech repairs. This paper presents an algorithm that detects and corrects speech repairs based on finding the repair pattern. The repair pattern is built by finding word matches and word replacements, and identifying fragments and editing terms. Rather than using a set of prebuilt templates, we build the pattern on the fly. In a the fair test, our method, when combined with a statistical model to filter possible repairs, was successful at detecting and correcting 80% of the repairs, without using prosodic information or a parser.
Thermal and reverse base current effects on heterojunction bipolar transistors and circuits

An empirical model of a heterojunction bipolar transistor is presented. The model expands the Gummel-Poon equations to account for device self-heating, base current reversal, and the collector-emitter offset voltage. It is shown that self-heating has implications for the cutoff frequency of the HBT, for the frequency response of a small-signal amplifier, and also for the thermal stability of a current mirror circuit. >
Combinatorics of the free Baxter algebra

We study the free (associative, non-commutative) Baxter algebra on one generator. The first explicit description of this object is due to Ebrahimi-Fard and Guo. We provide an alternative description in terms of a certain class of trees, which form a linear basis for this algebra. We use this to treat other related cases, particularly that in which the Baxter map is required to be quasi-idempotent, in a unified manner. Each case corresponds to a different class of trees. Our main focus is on the underlying combinatorics. In several cases, we provide bijections between our various classes of trees and more familiar combinatorial objects including certain Schroder paths and Motzkin paths. We calculate the dimensions of the homogeneous components of these algebras (with respect to a bidegree related to the number of nodes and the number of angles in the trees) and the corresponding generating series. An important feature is that the combinatorics is captured by the idempotent case; the others are obtained from this case by various binomial transforms. We also relate free Baxter algebras to Loday's dendriform trialgebras and dialgebras. We show that the free dendriform trialgebra (respectively, dialgebra) on one generator embeds in the free Baxter algebra with a quasi-idempotent map (respectively, with a quasi-idempotent map and an idempotent generator). This refines results of Ebrahimi-Fard and Guo.
Green and Brown? Globalization and the environment

Globalization--viewed as a process of economic integration that embraces governance as well as markets--could lead to worldwide convergence toward higher or lower environmental quality, or to environmental polarization in which the 'greening' of the global North is accompanied by the 'browning' of the global South. The outcome will not be dictated by an inexorable logic. Rather it will depend on how the opportunities created by globalization alter balances of power within countries and among them. Copyright 2004, Oxford University Press.
Stuck-free conformance

We present a novel refinement relation (stuck-free conformance) for CCS processes, which satisfies the substitutability property: If I conforms to S, and P is any environment such that P | S is stuck-free, then P | I is stuck-free. Stuck-freedom is related to the CSP notion of deadlock, but it is more discriminative by taking orphan messages in asynchronous systems into account. We prove that conformance is a precongruence on CCS processes, thereby supporting modular refinement. We distinguish conformance from the related preorders, stable failures refinement in CSP and refusal preorder in CCS. We have implemented conformance checking in a new software model checker, zing, and we report on how we used it to find errors in distributed programs.
Approaches to the Definition of Comparable Worth

Comparable worth is both a social and legal issue. Yet the issue of comparable worth is not new. It has been addressed in more basic terms in previous years. Different approaches to the definition of comparable worth are reviewed and compared as a background for the current social and political debate over the issue.
Winning Alone: The Electoral Fate of Independent Candidates Worldwide

Independent candidates are widely believed to influence the quality of representation through issues as fundamental to democracy as government accountability, responsiveness, and electoral turnout. Their impact, however, hinges on their electoral strength, which varies widely within and across countries. In order to explain this variation, this study examines which aspects of electoral systems affect independents the most and why. Based on a statistical analysis of 34 countries around the world between 1945 and 2003, this study finds that electoral systems influence the electoral strength of independent candidates by defining the opportunities for independents to compete for office (i.e., ballot access requirements), the degree to which politics is candidate centered versus partisan driven (i.e., majority/plurality rule, district magnitude, open-list PR, and democratic transitions), and the extent to which small vote getters win seats (i.e., district size and electoral thresholds). Accordingly, not only do independents influence the nature of representation, but so too do the ways in which electoral systems influence independent candidates.
The wisdom of the minority

We consider a simple variant of the canonical model of social learning and show that in many situations it is optimal for an agent to abandon her own information and follow the minority rather than the majority. This possibility depends on two economically meaningful requirements: agents are differentially informed and observe only the number of agents having chosen each option, such as consumers observing only market shares. We show that minority wisdom arises when information is sufficiently heterogeneous and the well informed are not overly abundant, yet the conditions necessary are not overly restrictive. In fact, it is possible for the minority to be wise even when the minority consists of a lone dissenter and a majority of citizens are well informed.
Scientific quality of original research articles on environmental tobacco smoke

OBJECTIVE: To evaluate the scientific quality of original research articles on the health effects of environmental tobacco smoke; to determine whether poor article quality is associated with publication in non-peer-reviewed symposium proceedings or with other article characteristics. DESIGN: Cross sectional study of original research articles on the health effects of environmental tobacco smoke published in peer reviewed journals and non-peer-reviewed symposium proceedings from 1980 to 1994. Article quality was assessed by two independent reviewers who used a valid and reliable instrument, were unaware of study hypotheses, were blinded to identifying characteristics of articles, and had no disclosed conflicts of interest. PARTICIPANTS: All symposium articles (n = 68) and a random sample of peer reviewed journal articles (n = 68) that satisfied inclusion/exclusion criteria. MAIN OUTCOME MEASURE: Mean quality scores, which could range from 0 (lowest quality) to 1 (highest quality). RESULTS: Using multivariate regression analysis, symposium articles were of poorer scientific quality than peer reviewed journal articles when controlling simultaneously for the effects of study design, article conclusion, article topic, and source of funding acknowledged (P = 0.027). Article quality was not associated with either source of funding acknowledged or article conclusion in multivariate analyses. CONCLUSIONS: In published reports on environmental tobacco smoke, non-peer-reviewed symposium articles tend to be of poor quality. These articles should not be used in scientific, legal, or policy settings unless their quality has been independently assessed.
Structure of yeast Argonaute with guide RNA

The RNA-induced silencing complex, comprising Argonaute and guide RNA, mediates RNA interference. Here we report the 3.2 A crystal structure of Kluyveromyces polysporus Argonaute (KpAGO) fortuitously complexed with guide RNA originating from small-RNA duplexes autonomously loaded by recombinant KpAGO. Despite their diverse sequences, guide-RNA nucleotides 1-8 are positioned similarly, with sequence-independent contacts to bases, phosphates and 2'-hydroxyl groups pre-organizing the backbone of nucleotides 2-8 in a near-A-form conformation. Compared with prokaryotic Argonautes, KpAGO has numerous surface-exposed insertion segments, with a cluster of conserved insertions repositioning the N domain to enable full propagation of guide-target pairing. Compared with Argonautes in inactive conformations, KpAGO has a hydrogen-bond network that stabilizes an expanded and repositioned loop, which inserts an invariant glutamate into the catalytic pocket. Mutation analyses and analogies to ribonuclease H indicate that insertion of this glutamate finger completes a universally conserved catalytic tetrad, thereby activating Argonaute for RNA cleavage.
Impedance-matched absorbers and optical pseudo black holes

We investigate the design of metamaterial blueprints for impedance-matched (reflectionless) absorbers over nonplanar surfaces in connection with optical pseudo black holes. The presence of some fundamental constraints on the existence of reflectionless absorber media at nonplanar surfaces are discussed based on analytical properties of the associated constitutive tensors on the complex ω (angular frequency) plane. In view of such constraints, some new metamaterial blueprints of near-reflectionless absorbers are suggested for integration into optical pseudo black hole devices.
LiBF4: A mild lewis acid for intramolecular diels-alder reactions.

Abstract The lithium salts, LiClO 4 and LiBF 4 , have been investigated for their potential use as Lewis acid catalysts in the intramolecular Diels-Alder reaction. No cycloaddition of the trienone, 1 , is observed when LiClO 4 is used. LiBF 4 provides quantitative yield of the cis -fused cycloadduct in 72 hours at room temperature. The catalysis is ascribed to the slow release of BF 3 rather than to the lithium cation.
The limit of a Stanley-Wilf sequence is not always rational, and layered patterns beat monotone patterns

We show the first known example for a pattern q for which L(q)=limn-∞ √Sn(q) is not an integer. where Sn(q) denotes the number of permutations of length n avoiding the pattern q. We find the exact value of the limit and show that it is irrational, but algebraic. Then we generalize our results to an infinite sequence of patterns. We provide further generalizations that start explaining why certain patterns are easier to avoid than others. Finally, we show that if q is a layered pattern of length k. Then L(q)≥(k-1)2 holds.
Where is the Land of Opportunity? The Geography of Intergenerational Mobility in the United States*

We use administrative records on the incomes of more than 40 million children and their parents to describe three features of intergenerational mobility in the United States. First, we characterize the joint distribution of parent and child income at the national level. The conditional expectation of child income given parent income is linear in percentile ranks. On average, a 10 percentile increase in parent income is associated with a 3.4 percentile increase in a child’s income. Second, intergenerational mobility varies substantially across areas within the U.S. For example, the probability that a child reaches the top quintile of the national income distribution starting from a family in the bottom quintile is 4.4% in Charlotte but 12.9% in San Jose. Third, we explore the factors correlated with upward mobility. High mobility areas have (1) less residential segregation, (2) less income inequality, (3) better primary schools, (4) greater social capital, and (5) greater family stability. While our descriptive analysis does not identify the causal mechanisms that determine upward mobility, the publicly available statistics on intergenerational mobility developed here can facilitate research on such mechanisms. The opinions expressed in this paper are those of the authors alone and do not necessarily reect
REDUCTIVE DECYANATION vs ADDITION OF GRIGNARD REAGENTS WITH HINDERED NITRILES

(1992). REDUCTIVE DECYANATION vs ADDITION OF GRIGNARD REAGENTS WITH HINDERED NITRILES. Organic Preparations and Procedures International: Vol. 24, No. 1, pp. 7-12.
Peter Berger and the Comedic Drama of Political, Economic and Social Life

Peter L. Berger’s work offers his readers a window into the human drama in all its dimension: political, economic and social. He invites his readers to think intensely, endlessly, and shamelessly about the doings of man. Through a comparative analysis of Invitation to Sociology this paper discusses Berger’s contributions to the sciences of man in terms of methodological individualism, the theory of unintended consequences, spontaneous sociability, institutional analysis, and freedom. In so doing, I hope to show that Berger’s work demonstrates the intellectual power of spontaneous order analysis and the link between the humanistic project in sociology and our understanding of the human condition in general and the freedom of the individual in society in particular.