cssi/SciSciGPT-SciSciNet huggingface dataset:
Free vortex and vortex-pair lifetimes in classical two-dimensional easy-plane magnets

We report numerical simulation results for free-vortex lifetimes in the critical region of classical two-dimensional easy-plane ferro- and antiferromagnets having three-component order parameters. The fluctuations in the vortex number density in a spin dynamics simulation were used to estimate the lifetimes. The observed lifetimes are of the same order of magnitude but smaller than the characteristic timescale above which a phenomenological ideal vortex-gas theory that has been used to account for the central peak in the dynamic structure factor is expected to be valid. For strong anisotropy, where the vortices are in-plane, the free vortex lifetimes for ferromagnets and antiferromagnets are the same, while for weak anisotropy, where the vortices have non-zero out-of-easy-plane components, the lifetimes in antiferromagnets are smaller than in ferromagnets. The dependence of the free-vortex and total vortex densities on the size dependent correlation length in the critical region is examined. We also determined the lifetimes of vortex-antivortex pairs for and well below . The observed timescales are very short, and the observed pair densities are extremely small. These results suggest that pair creation and annihilation are unlikely to play any role in the central peak in observed in computer simulations for the ferromagnetic model for .
Electrical and Optical Properties of a Novel Nonconjugated Conductive Polymer, Polynorbornene

We report electrical and optical properties of a novel nonconjugated conductive polymer, polynorbornene which has an isolated double bond in the repeat. Electrical conductivity of this polymer increases by twelve orders of magnitude to about 0.01 S/cm upon doping with iodine. Optical absorption measurements of the polymer film have been made at different dopant concentrations. For a lightly doped polymer, two absorption peaks: one corresponding to cation radicals and the other corresponding to charge transfer between the double bond and the dopant were observed at 4.20 eV (295 nm) and 3.13 eV (396 nm) respectively. FTIR spectroscopic measurements have shown reduction in the intensities of the C═C stretching and ═C─H bending vibration bands upon doping indicating formation of radical cations. Photoluminescence studies have shown an emission band with a major peak at ∼422 nm when excited at 280 nm. The peaks in the photoluminescence spectrum are consistent with the vibration bands observed in the FTIR spectrum.
The least squares fit of a hyperplane to uncertain data

Sensor based robotic systems are an important emerging technology. When robots are working in unknown or partially known environments, they need range sensors that will measure the Cartesian coordinates of surfaces of objects in their environment. Like any sensor, range sensors must be calibrated. The range sensors can be calibrated by comparing a measured surface shape to a known surface shape. The most simple surface is a plane and many physical objects have planar surfaces. Thus, an important problem in the calibration of range sensors is to find the best (least squares) fit of a plane to a set of 3D points. We have formulated a constrained optimization problem to determine the least squares fit of a hyperplane to uncertain data. The first order necessary conditions require the solution of an eigenvalue problem. We have shown that the solution satisfies the second order conditions (the Hessian matrix is positive definite). Thus, our solution satisfies the sufficient conditions for a local minimum. We have performed numerical experiments that demonstrate that our solution is superior to alternative methods.
PAIR INSTABILITY SUPERNOVAE: LIGHT CURVES, SPECTRA, AND SHOCK BREAKOUT

For the initial mass range (140 M ☉ < M < 260 M ☉) stars die in a thermonuclear runaway triggered by the pair-production instability. The supernovae they make can be remarkably energetic (up to ~1053 erg) and synthesize considerable amounts of radioactive isotopes. Here we model the evolution, explosion, and observational signatures of representative pair instability supernovae (PI SNe) spanning a range of initial masses and envelope structures. The predicted light curves last for hundreds of days and range in luminosity from very dim to extremely bright (L ~ 1044 erg s–1). The most massive events are bright enough to be seen at high redshift, but the extended light curve duration (~1 yr)—prolonged by cosmological time-dilation—may make it difficult to detect them as transients. A more promising approach may be to search for the brief and luminous outbreak occurring when the explosion shock wave first reaches the stellar surface. Using a multi-wavelength radiation-hydrodynamics code we calculate that, in the rest frame, the shock breakout transients of PI SNe reach luminosities of 1045-1046 erg s-1, peak at wavelengths ~30-170 A, and last for several hours. We discuss how observations of the light curves, spectra, and breakout emission can be used to constrain the mass, radius, and metallicity of the progenitor.
Choosing between fixed-and adjustable-rate mortgages: The case of commercial mortgages

This article reports on the determinants of the ARM choice for commercial real estate projects. The theoretical literature suggests that commercial real estate projects are more likely to be financed with an adjustable-rate mortgage (ARM) if the project's income stream or value is expected to rise with inflation over time. The empirical model estimated is a structural probit probability model of the ARM choice. Our results demonstrate that commercial borrowers typically place great emphasis on relative interest-rate differentials when deciding which mortgage is best. We also find that commercial mortgage borrowers will ordinarily be reluctant to issue an ARM when the fixed interest rate is low.
Effects of interplanetary transport on derived energetic particle source strengths

[1] We study the transport of solar energetic particles (SEPs) in the inner heliosphere in order to relate observations made by an observer at 1 AU to the number and total energy content of accelerated particles at the source, assumed to be near the Sun. We use a numerical simulation that integrates the trajectories of a large number of individual particles moving in the interplanetary magnetic field. We model pitch angle scattering and adiabatic cooling of energetic ions with energies from 50 keV nucleon−1 to 100 MeV nucleon−1. Among other things, we determine the number of times that particles of a given energy cross 1 AU and the average energy loss that they suffer because of adiabatic deceleration in the solar wind. We use a number of different forms of the interplanetary spatial diffusion coefficient and a wide range of scattering mean-free paths and consider a number of different ion species in order to generate a wide range of simulation results that can be applied to individual SEP events. We apply our simulation results to observations made at 1 AU of the 20 February 2002 solar energetic particle event, finding the original energy content of several species. We find that estimates of the source energy based on SEP measurements at 1 AU are relatively insensitive to the mean-free path and scattering scheme if adiabatic cooling and multiple crossings are taken into account.
Two-unicast two-hop interference network: Finite-field model

In this paper we present a novel framework to convert the K-user linear deterministic multiple access channel (MAC) over F pm into a K-user MAC over ground field F p with m multiple inputs/outputs (MIMO). This framework makes it possible to develop coding schemes for MIMO channels as done in symbol extension for time-varying channels. Using aligned network diagonalization based on this framework, we show that the sum-rate of (2m − 1)log p is achievable for a 2 × 2 × 2 interference channel over F pm , under certain conditions on channel coefficients. We also provide some interesting relation between field extension and symbol extension.
Confirmation of Eclipses in KPD 0422+5421, A Binary Containing a White Dwarf and a Subdwarf B Star

We report additional photometric CCD observations of KPD 0422+5421, a binary with an orbital period of 2.16 hours which contains a subdwarf B star (sdB) and a white dwarf. There are two main results of this work. First, the light curve of KPD 0422+5421 contains two distinct periodic signals, the 2.16 hour ellipsoidal modulation discovered by Koen, Orosz, & Wade (1998) and an additional modulation at 7.8 hours. This 7.8 hour modulation is clearly not sinusoidal: the rise time is about 0.25 in phase, whereas the decay time is 0.75 in phase. Its amplitude is roughly half of the amplitude of the ellipsoidal modulation. Second, after the 7.8 hour modulation is removed, the light curve folded on the orbital period clearly shows the signature of the transit of the white dwarf across the face of the sdB star and the signature of the occultation of the white dwarf by the sdB star. We used the Wilson-Devinney code to model the light curve to obtain the inclination, the mass ratio, and the potentials, and a Monte Carlo code to compute confidence limits on interesting system parameters. We find component masses of MsdB = 0.36 +0.37 −0.16 M⊙ and MWD = 0.47 +0.18 −0.16 M⊙ (Mtotal = 0.86 +0.52 −0.35 M⊙, 68 per cent confidence limits). If we impose an additional constraint and require the computed mass and radius of the white dwarf to be consistent with a theoretical mass-radius relation, we find MsdB = 0.511 +0.047 −0.050 M⊙ and MWD = 0.526 +0.033 −0.030 M⊙ (68 per cent confidence limits). In this case the total mass of the system is less than 1.4 M⊙ at the 99.99 per cent confidence level. We briefly discuss possible interpretations of the 7.8 hour modulation and the importance of KPD 0422+5421 as a member of a rare class of evolved binaries.
Fine structure of the zeros of orthogonal polynomials, II. OPUC with competing exponential decay

We present a complete theory of the asymptotics of the zeros of OPUC with Verblunsky coefficients αn = Σl=1L Cl bln + O((bΔ)n) where Δ < 1 and |bl| = b < 1.
P-20 Education Policy: School to College Transition Policy in Washington State

This study examines Washington State’s attempt to move toward an integrated, P-20 system of education that enhances student transitions from high school to college. In analyzing Washington as a single case study, a profile of the state is developed on key access related characteristics. Data for this study were gathered utilizing fundamental case study methods. In depth qualitative interviews were conducted with Washington State Legislators, legislative staff, key state education agency officials, and college and university representatives. Document analyses of agency records, public hearings, testimonies, position papers, reports, and public meeting records were also conducted. This study found that Washington has many key programs in place to enhance student transitions between the K-12 system and the higher education, but the state’s current approach lacks coherence and cohesion. This study also found that the state has developed a new and innovative model with the potential to solve many transition related issues, but it will require assessment to determine its actual effectiveness.
Almost Alternating Sums

as N -> oo is not transparent (here [x\ signifies the greatest integer not larger than x). The random walk J2n=\ wm where the wn are independent random variables taking the values 1 and ? 1 with equal probability, is known to have absolute value typically around c\f? for an appropriate constant c and large N [23]. Knowing this and know ing also that for irrational a the sequence \na\ is "random-ish" modulo 2, a natural guess is that |Sw(a)| is also around \//V. Contrary to this expectation, for almost all real numbers a
The Multiplexing Gain of MIMO X-Channels with Partial Transmit Side-Information

In this paper, we obtain the scaling laws of the sum-rate capacity of a MIMO X-channel, a 2 independent sender, 2 independent receiver channel with messages from each transmitter to each receiver, at high signal to noise ratios (SNR). The X-channel has sparked recent interest in the context of cooperative networks and it encompasses the interference, multiple access, and broadcast channels as special cases. Here, we consider the case with partially cooperative transmitters in which asymmetric side-information (in the form of a codeword) is available at one of the transmitters. It is proved that when there are M antennas at all four nodes, the sum-rate scales like 2M log SNR which is in sharp contrast to lceillfloor4M/3rfloor, 4M/3rceil log SNR for non-cooperative X-channels [M. Maddah-Ali et al., 2006], [S.A. Jafar]. This further proves that, in terms of sum-rate scaling at high SNR, partial side-information at one of the transmitters and full side-information at both transmitters are equivalent in the MIMO X-channel.
The double Coxeter arrangement

Let V be Euclidean space. Let $ W \subset {\bf G L}(V) $ be a finite irreducible reflection group. Let $ \cal {A} $ be the corresponding Coxeter arrangement. Let S be the algebra of polynomial functions on V. For $ H \in \cal {A} $ choose $ \alpha_H \in V^* $ such that $ H = {\rm ker}(\alpha_H) $ . The arrangement $ {\cal A} $ is known to be free: the derivation module $ D({\cal A}) = \{ \theta \in {\rm Der}_S ~|~ \theta(\alpha_H) \in S \alpha_H \} $ is a free S-module with generators of degrees equal to the exponents of W. In this paper we prove an analogous theorem for the submodule $ E({\cal A}) $ of $ D({\cal A})$ defined by $ E({\cal A}) = \{\theta \in {\rm Der}_S ~|~ \theta(\alpha_H) \in S \alpha_H^2\} $ . The degrees of the basis elements are all equal to the Coxeter number. The module $ E({\cal A}) $ may be considered a deformation of the derivation module for the Shi arrangement, which is conjectured to be free. The proof is by explicit construction using a derivation introduced by K. Saito in his theory of flat generators.
Synthesis of Natural and Modified Trapoxins, Useful Reagents for Exploring Histone Deacetylase Function

Trapoxin, a cyclotetrapeptide isolated from the fungus Helicoma ambiens, profoundly affects mammalian cell growth and morphology. In this paper, we describe syntheses of trapoxin, [3H]trapoxin, and K-trap, a trapoxin-based affinity reagent. These reagents have allowed us to achieve the first molecular characterization of histone deacetylase, trapoxin's cellular target.
Regimes of thermocapillary migration of droplets under partial wetting conditions

We study the thermocapillary migration of two-dimensional droplets of partially wetting liquids on a non-uniform heated substrate. An equation for the thickness profile of the droplet is derived by employing lubrication approximations. The model includes the effect of a non-zero contact angle introduced through a disjoining― conjoining pressure term. Instead of assuming a fixed shape for the droplet, as in previous works, here we allow the droplet to change its profile with time. We identify and describe three different regimes of behaviour. For small contact angles, the droplet spreads into a long film profile with a capillary ridge near the leading edge, a behaviour that resembles the experiments on Marangoni films reported by Ludviksson & Lightfoot (Am. Inst. Chem. Eng. J., vol. 17, 1971, pp. 1166). For large contact angles, the droplet moves as a single entity, weakly distorted from its static shape. This regime is the usual one reported in experiments on thermocapillary migration of droplets. We also show some intriguing morphologies that appear in the transition between these two regimes. The occurrence of these three regimes and their dependence on various parameters is analysed.
A Stochastic Approach for Parameterizing Unresolved Scales in a System with Memory

Complex systems display variability over a broad range of spatial and temporal scales. Some scales are unresolved due to computational limitations. The impact of these unresolved scales on the resolved scales needs to be parameterized or taken into account. One stochastic parameterization scheme is devised to take the effects of unresolved scales into account, in the context of solving a nonlinear partial differential equation with memory (a time-integral term), via large eddy simulations. The obtained large eddy simulation model is a stochastic partial differential equation. Numerical experiments are performed to compare the solutions of the original system and of the stochastic large eddy simulation model.
Palladium-catalyzed amidation of 2-chloropyrimidines

Abstract A mild and efficient Pd-catalyzed coupling of amides with 2-chloropyrimidines is described. The use of bidentate phosphines, such as Xantphos ( 7 ), as supporting ligands was found to be crucial for providing high yields of 2-( N -acylamino)pyrimidine coupling products 1 .
The 12-month prevalence and trends in DSM-IV alcohol abuse and dependence: United States, 1991-1992 and 2001-2002.

Abstract Background : Alcohol abuse and dependence can be disabling disorders, but accurate information is lacking on the prevalence of current DSM-IV alcohol abuse and dependence and how this has changed over the past decade. The purpose of this study was to present nationally representative data on the prevalence of 12-month DSM-IV alcohol abuse and dependence in 2001–2002 and, for the first time, to examine trends in alcohol abuse and dependence between 1991–1992 and 2001–2002. Methods : Prevalences and trends of alcohol abuse and dependence in the United States were derived from face-to-face interviews in the National Institute on Alcohol Abuse and Alcoholism’s (NIAAA) 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC: n =43,093) and NIAAA’s 1991–1992 National Longitudinal Alcohol Epidemiologic Survey (NLAES: n =42,862). Results : Prevalences of DSM-IV alcohol abuse and dependence in 2001–2002 were 4.65 and 3.81%. Abuse and dependence were more common among males and among younger respondents. The prevalence of abuse was greater among Whites than among Blacks, Asians, and Hispanics. The prevalence of dependence was higher in Whites, Native Americans, and Hispanics than Asians. Between 1991–1992 and 2001–2002, abuse increased while dependence declined. Increases in alcohol abuse were observed among males, females, and young Black and Hispanic minorities, while the rates of dependence rose among males, young Black females and Asian males. Conclusions : This study underscores the need to continue monitoring prevalence and trends and to design culturally sensitive prevention and intervention programs.
SEMICONDUCTOR RADIATION DETECTORS.

The past decade has seen the rapid development and exploitation of one of the most significant tools of nuclear physics, the semiconductor radiation detector. Applications of the device to the anal...
Facile Synthesis of Lipophilic δ-Amino Acid Conjugates from 4-Alkoxy-dithionaphthoic Acids

Abstract Novel 4-alkoxy-dithionaphthoic acids were prepared and shown to be valuable synthons for δ-amino acid conjugates. These dithioacids are efficiently synthesized and purified, stable to storage, and easily derivatized to facilitate thioacylation chemistry. To this end, we have demonstrated dithionaphthoic acids (6) to successfully undergo coupling with both protected and unprotected amino acids, giving rise to stable thioamide conjugates (8 and 9).
The equality of solutions in vacuum string field theory

Abstract We analytically prove that the matter solution of vacuum string field theory constructed by Kostelecky and Potting is the matter sliver state. We also give an analytical proof that the ghost solution by Hata and Kawano is the sliver state in the twisted ghost CFT. It is also proved that the candidate state for the tachyon proposed by Hata and Kawano can be identified with the state constructed by Rastelli, Sen and Zwiebach using CFT. Our proofs are based on the techniques recently developed by Okuyama.
Solar and atmospheric neutrinos.

Possible explanations of solar neutrino and atmospheric neutrino anomalies are summarized and future tests discussed.
Conditional event studies, anticipation, and asymmetric information: the case of seasoned equity issues and pre-issue information releases

Abstract Information disclosed before equity issue announcements could reduce the price drops at the announcements by (1) reducing uncertainty about managers' private information, and/or (2) helping investors to anticipate the equity issues. To distinguish between these effects, we examine the determinants of firms' decisions to issue equity, and develop a conditional event-study procedure, based on Acharya [Acharya, S., 1988, A generalized econometric model and tests of a signaling hypothesis with two discrete signals, Journal of Finance, 43, 413–429.], that distinguishes between anticipation and asymmetric information. After controlling for differences in uncertainty across firms, we present evidence that stock split declarations, dividend announcements and earnings releases help investors to anticipate equity issues, but do not reduce asymmetric information.
Do Moral Communities Play a Role in Criminal Sentencing? Evidence From Pennsylvania

Religion and social control have been a sociological concern since Durkheim and Weber, and the relationship between religion and punishment has long been the subject of speculation. However, surprisingly little empirical research exists on the role of religion or religious context in criminal justice, and almost no research on the role of religious context on actual sentencing practices. We conceptualize the potential relationships between religious context and sentencing severity by drawing from the focal concerns and court community perspectives in the sentencing literature and moral communities theory developed by Rodney Stark. We suspect that Christian moral communities might shape notions of perceived blameworthiness for court community actors. Such moral communities might also affect notions of community protection - affecting perceptions of dangerousness, or perhaps rehabilitation, and might influence practical constraints/consequences (e.g., local political ramifications of harsh or lenient sentences). We examine these questions using a set of hierarchical models using sentencing data from Pennsylvania county courts and data on the religious composition of Pennsylvania counties from the Associated Religion Data Archives. We find that county Christian religious homogeneity increases the likelihood of incarceration. In addition, Christian homogeneity as well as the prevalence of civically engaged denominations in a county condition the effects of important legally relevant determinants of incarceration. Furthermore, we find evidence that Christian homogeneity activates the effect of local Republican electoral dominance on incarceration. We argue that Christian homogeneity effects sentencing practices primarily through local political processes that shape the election of judges and prosecutors.
Solar Dynamics Observatory and Hinode Observations of a Blowout Jet in a Coronal Hole

A blowout jet occurred within the south coronal hole on 9 February 2011 at 09:00 UT and was observed by the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory, and by the EUV Imaging Spectrometer (EIS) and X-Ray Telescope (XRT) onboard the Hinode spacecraft during coronal-hole monitoring performed as part of Hinode Operations Program No. 177. Images from AIA show expanding hot and cold loops from a small bright point with plasma ejected in a curtain up to 30 Mm wide. The initial intensity front of the jet had a projected velocity of 200 km s−1, and the line-of-sight (LOS) velocities measured by EIS are between 100 and 250 km s−1. The LOS velocities increased along the jet, implying that an acceleration mechanism operates within the body of the jet. The jet plasma had a density of 2.7×108 cm−3 and a temperature of 1.4 MK. During the event a number of bright kernels were seen at the base of the bright point. The kernels have sizes of ≈ 1000 km, are variable in brightness, and have lifetimes of 1 – 15 minutes. An XRT filter ratio yields temperatures of 1.5 – 3.0 MK for the kernels. The bright point existed for at least ten hours, but disappeared within two hours after the jet, which lasted for 30 minutes. HMI data reveal converging photospheric flows at the location of the bright point, and the mixed-polarity magnetic flux canceled over a period of four hours on either side of the jet.
Spectrum of the Hermitian Wilson Dirac operator

Abstract Recent results on the spectral properties of the Hermitian Wilson-Dirac operator are presented.
RIGHT-ANGLED ARTIN GROUPS AND A GENERALIZED ISOMORPHISM PROBLEM FOR FINITELY GENERATED SUBGROUPS OF MAPPING CLASS GROUPS

Consider the mapping class group Mod g,p of a surface Σ g,p of genus g with p punctures, and a finite collection {f1, . . . , fk} of mapping classes, each of which is either a Dehn twist about a simple closed curve or a pseudo-Anosov homeomorphism supported on a connected subsurface. In this paper we prove that for all sufficiently large N, the mapping classes $${\{f_1^N,\ldots,f_k^N\}}$$ generate a right-angled Artin group. The right-angled Artin group which they generate can be determined from the combinatorial topology of the mapping classes themselves. When {f1, . . . , fk} are arbitrary mapping classes, we show that sufficiently large powers of these mapping classes generate a group which embeds in a right-angled Artin group in a controlled way. We establish some analogous results for real and complex hyperbolic manifolds. We also discuss the unsolvability of the isomorphism problem for finitely generated subgroups of Mod g,p , and recover the fact that the isomorphism problem for right-angled Artin groups is solvable. We thus characterize the isomorphism type of many naturally occurring subgroups of Mod g,p .
Chandra Observation of the Radio Source/X-Ray Gas Interaction in the Cooling Flow Cluster Abell 2052

We present a Chandra observation of Abell 2052, a cooling flow cluster with a central cD galaxy that hosts the complex radio source 3C 317. The data reveal "holes" in the X-ray emission that are coincident with the radio lobes. The holes are surrounded by bright "shells" of X-ray emission. The data are consistent with the radio source displacing and compressing, and at the same time being confined by, the X-ray gas. The compression of the X-ray shells appears to have been relatively gentle and, at most, slightly transonic. The pressure in the X-ray gas (the shells and surrounding cooler gas) is approximately an order of magnitude higher than the minimum pressure derived for the radio source, suggesting that an additional source of pressure is needed to support the radio plasma. The compression of the X-ray shells has speeded up the cooling of the shells, and optical emission-line filaments are found coincident with the brightest regions of the shells.
Synthesis of N-substituted pyrrolo[3,4-b]indoles from 2,3-dimethylindole

Pyrrolo[3,4-b]indoles 8 are conveniently synthesized from 2,3-dimethylindole (4) in four steps, the last of which is DDQ oxidation of dihydropyrrolo[3,4-b]indoles 7 (85–98% yield).
Formation, Isolation, and Spectroscopic Properties of Some Isomers of C60H38, C60H40, C60H42, and C60H44 − Analysis of the Effect of the Different Shapes of Various Helium‐Containing Hydrogenated Fullerenes on Their 3He Chemical Shifts

A complex mixture of C60H38 to C60H44 has been prepared by a much milder procedure (Benkeser reduction) than the hydrogenation procedures that have frequently been used to produce such highly hydrogenated derivatives of C60. 1H and 13C NMR spectra of fractions isolated by HPLC showed that more highly hydrogenated fullerenes exhibited signals that were shifted upfield. The opposite trend appears to hold in 3He NMR spectra of the corresponding endohedral helium compounds. The changes in the 1H, 13C, and 3He chemical shifts are reasonable for fullerenes hydrogenated to different extents. In particular, previously reported substantial changes in the shapes of the various hydrogenated fullerenes can reasonably account for the interesting trends apparent both in the 3He chemical shifts of He@C60Hx (x = 0−44) and in the HPLC retention times of the corresponding non-helium-containing species. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Stellar Bar Evolution in Cuspy and Flat-cored Triaxial CDM Halos

We analyze the formation and evolution of stellar bars in galactic disks embedded in mildly triaxial cold dark matter (CDM) halos that have density distributions ranging from large flat cores to cuspy profiles. We have applied tailored numerical simulations of analytical and live halos that include the feedback from disk/bar system onto the halo in order to test and extend earlier work by El-Zant and Shlosman. The latter employed the method of Liapunov exponents to analyze the fate of bars in analytical asymmetric halos. We find the following: (1) The bar growth is very similar in all rigid axisymmetric and triaxial halos. (2) Bars in live models experience vertical buckling instability and the formation of a pseudobulge with a boxy/peanut shape, while bars in rigid halos do not buckle. (3) In live axisymmetric halos, the bar strength varies by a factor of 2, in growth or decay, during the secular evolution following the buckling. The bar pattern speed evolution (i.e., deceleration) anticorrelates with the halo core size. In such halos, the bar strength is larger for smaller disk-to-halo mass ratios (D/H) within disk radii, the bar size correlates with the halo core sizes, and the bar pattern speeds correlate with the halo central mass concentration. In contrast, bars embedded in live triaxial halos have a starkly different fate: they dissolve on a timescale of ~1.5-5 Gyr due to the onset of chaos over continuous zones, sometimes leaving behind a weak oval distortion. The onset of chaos is related to the halo triaxiality, the fast-rotating bar, and the halo cuspiness. Before the bar dissolves, the region outside it develops strong spiral structures, especially in the live triaxial halos. (4) More angular momentum is absorbed (fractionally) by the triaxial halos than in the axisymmetric models. The disk-halo angular momentum exchange is mediated by the lower resonances in the latter models. (5) Cuspy halos are more susceptible than flat-core halos to having their prolateness washed out by the action of the bar. The subsequent evolution is then similar to the case of cuspy axisymmetric halos. We analyze the above results on disk and bar evolution in terms of the stability of trajectories and development of chaos in the system. We set important constraints on the triaxiality of dark matter (DM) halos by comparing our predictions to recent observational results on the properties of bars out to intermediate redshifts z ~ 1.
Characterization of tunable FGF-2 releasing polyelectrolyte multilayers

Fibroblast growth factor 2 (FGF-2) is a potent mediator of stem cell differentiation and proliferation. Although FGF-2 has a well-established role in promoting bone tissue formation, flaws in its delivery have limited its clinical utility. Polyelectrolyte multilayer films represent a novel system for FGF-2 delivery that has promise for local, precisely controlled, and sustained release of FGF-2 from surfaces of interest, including medical implants and tissue engineering scaffolds. In this work, the loading and release of FGF-2 from synthetic hydrolytically degradable multilayer thin films of various architectures is explored; drug loading was tunable using at least three parameters (number of nanolayers, counterpolyanion, and type of degradable polycation) and yielded values of 7-45 ng/cm(2) of FGF-2. Release time varied between 24 h and approximately five days. FGF-2 released from these films retained in vitro activity, promoting the proliferation of MC3T3 preosteoblast cells. The use of biologically derived counterpolyanions heparin sulfate and chondroitin sulfate in the multilayer structures enhanced FGF-2 activity. The control over drug loading and release kinetics inform future in vivo bone and tissue regeneration models for the exploration of clinical relevance of LbL growth factor delivery films.
Products of Floer Cohomology of Torus Fibers in Toric Fano Manifolds

We compute the ring structure of Floer cohomology groups of Lagrangian torus fibers in some toric Fano manifolds continuing the study of [CO]. Related A∞-formulas hold for a transversal choice of chains. Two different computations are provided: a direct calculation using the classification of holomorphic discs by Oh and the author in [CO], and another method by using an analogue of divisor equation in Gromov-Witten invariants to the case of discs. Floer cohomology rings are shown to be isomorphic to Clifford algebras, whose quadratic forms are given by the Hessians of functions W, which turn out to be the superpotentials of Landau-Ginzburg mirrors. In the case of Open image in new window, this proves the prediction made by Hori, Kapustin and Li by B-model calculations via physical arguments. The latter method also provides correspondence between higher derivatives of the superpotential of LG mirror with the higher products of the A∞(or L∞)-algebra of the Lagrangian submanifold.
Universality in Random Matrix Theory for orthogonal and symplectic ensembles

We give a proof of the Universality Conjecture for orthogonal and symplectic ensembles of random matrices in the scaling limit for a class of weights w(x)=exp(-V(x)) where V is a polynomial, V(x)=kappa_{2m}x^{2m}+..., kappa_{2m}>0. For such weights the associated equilibrium measure is supported on a single interval. The precise statement of our results is given in Theorem 1.1 below. For a proof of the Universality Conjecture for unitary ensembles, for the same class of weights, see [DKMVZ2]. Our starting point is Widom's representation [W] of the orthogonal and symplectic correlation kernels in terms of the kernel arising in the unitary case plus a correction term which is constructed out of derivatives and integrals of orthonormal polynomials (OP's) {p_j(x)}, j=0,1,..., with respect to the weight w(x). The calculations in [W] in turn depend on the earlier work of Tracy and Widom [TW2]. It turns out (see [W] and also Theorems 2.1 and 2.2 below) that only the OP's in the range j=N+O(1), N->infinity, contribute to the correction term. In controlling this correction term, and hence proving Universality for both the orthogonal and symplectic cases, the uniform Plancherel--Rotach type asymptotics for the OP's found in [DKMVZ2] play an important role, but there are significant new analytical difficulties that must be overcome which are not present in the unitary case. We note that we do not use skew orthogonal polynomials.
THE SUN'S PREFERRED LONGITUDES AND THE COUPLING OF MAGNETIC DYNAMO MODES

Observations show that solar activity is distributed nonaxisymmetrically, concentrating at preferred longitudes.
UNDERSTANDING, MEASURING AND UTILIZING SOCIAL CAPITAL: CLARIFYING CONCEPTS AND PRESENTING A FIELD APPLICATION FROM INDIA

Abstract Social capital has been defined as a resource, a propensity for mutually beneficial collective action, that communities possess to different extents. Communities with high levels of social capital are able to act together collectively for achieving diverse common objectives. While the concept of social capital is valid universally, the measure of social capital will vary by context. It must be related in each case to aspects of social relations that assist mutually beneficial collective action within that particular cultural context. A locally-relevant scale of social capital was developed to assess whether and how social capital mattered for development performance in 69 north Indian villages. Variables corresponding to other bodies of explanation, including extent of commercialisation, relative stratification, and relative need were also examined, but a combination of high social capital and capable agency was found to associate most closely with high development performance. Agency is important particularly in situations where institutions are not available that enable citizens to connect with the state and with markets. The productivity of social capital is considerably reduced on account of this institutional gap. Development performance can be improved in these situations by adding to the stock of social capital and also through enhancing agency capacity.
Localized States and resultant band bending in graphene antidot superlattices.

We fabricated dye sensitized graphene antidot superlattices with the purpose of elucidating the role of the localized edge state density. The fluorescence from deposited dye molecules was found to strongly quench as a function of increasing antidot filling fraction, whereas it was enhanced in unpatterned but electrically backgated samples. This contrasting behavior is strongly indicative of a built-in lateral electric field that accounts for fluorescence quenching as well as p-type doping. These findings are of great interest for light-harvesting applications that require field separation of electron−hole pairs.
Pattern formation and coarsening dynamics in three-dimensional convective mixing in porous media

Geological carbon dioxide (CO2) sequestration entails capturing and injecting CO2 into deep saline aquifers for long-term storage. The injected CO2 partially dissolves in groundwater to form a mixture that is denser than the initial groundwater. The local increase in density triggers a gravitational instability at the boundary layer that further develops into columnar plumes of CO2-rich brine, a process that greatly accelerates solubility trapping of the CO2. Here, we investigate the pattern-formation aspects of convective mixing during geological CO2 sequestration by means of high-resolution three-dimensional simulation. We find that the CO2 concentration field self-organizes as a cellular network structure in the diffusive boundary layer at the top boundary. By studying the statistics of the cellular network, we identify various regimes of finger coarsening over time, the existence of a non-equilibrium stationary state, and a universal scaling of three-dimensional convective mixing.
The Valuation Effect of Accounting Standard 158 on Firms with High and Low Financial Risk

SFAS 158 mandated balance sheet disclosure of the funded status of firms’ Defined Benefit Pension Plan using the Projected Benefit Obligation (PBO) to estimate the pension liability. SFAS 158 caused a market phenomenon because the use of the PBO engendered dramatically higher estimates of pension liability and hence the perception of risk. Our work focuses on two aspects of this change in pension accounting: first, how will industry firms change their accounting strategy in light of the new rules, and second, how will firms’ stock prices be affected by the new allegedly better estimate of pension liability? Our research suggests that firms’ accounting strategies changed in that they use higher discount rates to estimate pension liability which offset the dramatic impact of using the PBO. In addition, we find that high financial risk firms’ tendencies to use higher discount rates increase with the firms’ leverage and decrease with liquidity. To test the market reaction we utilize standard event study methodology to investigate the effects of SFAS 158 on stock returns. Our findings suggest that firms with high (low) financial risk earn negative (positive) abnormal returns on and around relevant event dates preceding the implementation of SFAS 158.
What's interesting about strangeness production? An overview of recent results

In this paper, I highlight a few selected topics on strange particle production in heavy-ion collisions. By studying the yield and spectra of strange particles we hope to gain understanding of the conditions reached in, and the ensuing dynamics of, the systems produced when ultra-relativistic heavy ions are collided.
INFECTION OF GUINEA PIGS BY APPLICATION OF VIRUS OF LYMPHOCYTIC CHORIOMENINGITIS TO THEIR NORMAL SKINS

As shown in Table I, 97 guinea pigs were used in this study. Fifty-seven were exposed by placing a virus suspension on their normal skins. Of this number, 34 had screw-top capsules attached to them. Thirteen were exposed by spreading the virus suspension on their feed and cage litter. Ten were inoculated intracerebrally to establish the potency of the virus. The remaining 17 were not exposed artificially to the virus and were employed as controls to detect cross infection. Twenty-two guinea pigs, to which capsules were attached, died as a result of virus infection; 1 died of unknown causes and 11 survived without showing any clinical signs of the infection. Sixteen of the animals without the capsules died of virus infection and 7 did not become infected. The 10 guinea pigs that were inoculated intracerebrally became infected and died. None of the animals that were exposed by spreading the virus on the feed and the litter in the cages, or those used as unexposed controls, developed any clinical signs of infection with lymphocytic choriomeningitis. It is realized that minute abrasions, not visible with a hand lens, may have been present in the skins of these guinea pigs. However, any condition of this nature would be a factor encountered in any normal skin. In view of these facts, it is believed that these results indicate that the virus of lymphocytic choriomeningitis may infect guinea pigs through the normal, apparently intact, skin.
Numerical evolution of squeezed and non-Gaussian states in loop quantum cosmology

In recent years, numerical simulations with Gaussian initial states have demonstrated the existence of a quantum bounce in loop quantum cosmology in various models. A key issue pertaining to the robustness of the bounce and the associated physics is to understand the quantum evolution for more general initial states, which may depart significantly from Gaussianity and may have no well defined peakedness properties. The analysis of such states, including squeezed and highly non-Gaussian states, has been computationally challenging until now. In this paper, we overcome these challenges by using the Chimera scheme for the spatially flat, homogeneous and isotropic model sourced with a massless scalar field. We demonstrate that the quantum bounce in this model occurs even for states that are highly squeezed or are non-Gaussian with multiple peaks and with little resemblance to semi-classical states. The existence of the bounce is found to be robust, being independent of the properties of the states. The evolution of squeezed and non-Gaussian states turns out to be qualitatively similar to that of Gaussian states, and satisfies strong constraints on the growth of the relative fluctuations across the bounce. We also compare the results from the effective dynamics and find that, although it captures the qualitative aspects of the evolution for squeezed and highly non-Gaussian states, it always underestimates the bounce volume. We show that various properties of the evolution, such as the energy density at the bounce, are in excellent agreement with the predictions from an exactly solvable loop quantum cosmological model for arbitrary states.
Black hole non-formation in the matrix model

The leading classical low-energy effective actions for two-dimensional string theories have solutions describing the gravitational collapse of shells of matter into a black hole. It is shown that string loop corrections can be made arbitrarily small up to the horizon, but α' corrections cannot. The matrix model is used to show that typical collapsing shells do not form black holes in the full string theory. Rather, they backscatter out to infinity just before the horizon forms. The matrix model is also used to show that the naively expected particle production induced by the collapsing shell vanishes to leading order. This agrees with the string theory computation. From the point of view of the effective low energy field theory this result is surprising and involves a delicate cancellation between various terms.
Enantioselective alkene radical cations reactions

The reaction of enantiomerically enriched 2-methyl-2-nitro-3-(diphenylphosphatoxy)alkyl radicals with tributyltin hydride and AIBN in benzene at reflux results in the formation of alkene radical cation/anion pairs, which are trapped intramolecularly by amine nucleophiles, leading to pyrrolidine and piperidine systems with memory of stereochemistry. The scope and limitations of the system are explored with respect to nucleophile, leaving group, and substituents within the substrate backbone.
The Influence of Outer Solar System Architecture on the Structure and Evolution of the Oort Cloud

We study the influence of outer solar system architecture on the structural evolution of the Oort Cloud (OC) and the flux of Earth-crossing comets. In particular, we seek to quantify the role of the giant planets as planetary protectors. To do so, we have run simulations in each of four different planetary mass configurations to understand the significance of each of the giant planets. Because the outer planets modify the structure of the OC throughout its formation, we integrate each simulation over the full age of the solar system. Over this time, we follow the evolution of cometary orbits from their starting point in the protoplanetary disk to their injection into the OC to their possible re-entry into the inner planetary region. We find that the overall structure of the OC, including the location of boundaries and the relative number of comets in the inner and outer parts, does not change significantly between configurations; however, as planetary mass decreases, the trapping efficiency (TE) of comets into the OC and the flux of comets into the observable region increases. We determine that those comets that evolve onto Earth-crossing orbits come primarily from the inner OC but show no preference for initial protoplanetary disk location. We also find that systems that have at least a Saturn-mass object are effective at deflecting possible Earth-crossing comets but the difference in flux between systems with and without such a planet is less than an order of magnitude. We conclude by discussing the individual roles of the planets and the implications of incorporating more realistic planetary accretion and migration scenarios into simulations, particularly on existing discrepancies between low TE and the mass of the protoplanetary disk and on determining the structural boundaries of the OC.
Crop residue decomposition in Minnesota biochar-amended plots

Abstract. Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different plant-based feedstocks and pyrolysis platforms in the fall of 2008. Litterbags containing wheat straw material were buried in July of 2011 below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a uncharred wood-pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Overall, these findings indicate that no significant alteration in the microbial dynamics of the soil decomposer communities occurred as a consequence of the application of plant-based biochars evaluated here.