cssi/SciSciGPT-SciSciNet huggingface dataset:
Analytical selenoamino acid studies by chromatography with interfaced atomic mass spectrometry and atomic emission spectral detection

Consumption of selenium enriched plants or yeast-based nutritional supplements has been reported to provide anticarcinogenic benefits which are selenium compound dependent. Separation and identification of these selenium compounds is critical to understand the activity. Plants and yeast convert inorganic selenium in the soil or growth media into organoselenium compounds, probably following a route similar to the sulfur assimilatory pathway. Non-volatile selenium compounds produced include selenoamino acids, some of which have shown anticarcinogenic activity. Volatile compounds produced by chemical reaction of involatile precursors have also been found. An ion pair chromatographic method with ICP-MS detection for the separation of selenoamino acid standards potentially present in real samples is given. The method allows separation of selenoamino acids including such analytes as the cis-trans isomers of Se-1-propenyl-dl-selenocysteine. The method also provides the capability of determining the presence of selenoxides and possibly selenones, and tracking of other functionalities and reactions by selective derivatization. Alternatively, selenoamino acids are treated with ethylchloroformate to produce stable volatile derivatives which are amenable to GC separation with element specific atomic emission detection (GC-AED). Results of total selenium determination and speciation of selenium enriched yeast-based nutritional supplements, selenium enriched allium vegetables and bioremediation samples are presented.
Prolactin production by explants of normal, luteal phase defective, and corrected luteal phase defective late secretory endometrium

The production of prolactin by explants of late secretory endometrium has been correlated with the extent of decidual differentiation. This correlation is strengthened by the observation that luteal phase defective endometrium produces less prolactin than normal control endometrium in a 24-hour in vitro culture system. In the present study the prolactin production by explants of normal, luteal phase defective, progesterone-corrected luteal phase defective, and clomiphene- or follicle-stimulating hormone/luteinizing hormone-corrected luteal phase defective late secretory endometrium was measured over 96 hours at 24-hour intervals. Progesterone in physiologic concentrations was added to the culture medium to maintain tissue integrity and prolactin synthesis. The prolactin production of normal late secretory endometrium rose over 96 hours under progesterone stimulation. The luteal phase defective endometrium produced significantly less prolactin under the same conditions. Histologically proven corrected luteal phase defective endometrium, regardless of treatment method, produced prolactin not different from the normal controls of the same dates. From these results it is concluded that histologic correction of luteal phase defective endometrium is associated with a corresponding biochemical correction with use of prolactin as a metabolic marker. The findings also strongly support timed endometrial biopsy as the method of diagnosis and evaluation of treatment of luteal phase defect.
Four-brane and six-brane interactions in M(atrix) theory

Abstract We discuss the proposed description of configurations with four-branes and six-branes in M(atrix) theory. Computing the velocity dependent potential between these configurations and gravitons and membranes, we show that they agree with the short distance string results computed in type IIA string theory. Due to the “closeness” of these configuration to a supersymmetric configuration the M(atrix) theory reproduces the correct long distance behavior.
Synthesis and activity of γ-(L-γ-azaglutamyl)-S-(p-bromobenzyl)-L-cysteinylglycine: A metabolically stable inhibitor of glyoxalase I

The inhibition of glyoxalase I enzyme to increase cellular levels of methylglyoxal has been developed as a rationale for the production of anticancer agents. Synthesis of a peptidomimetic analog of the previously prepared potent glyoxalase inhibitor, S-(p-bromobenzyl)glutathione (PBBG), was accomplished by inserting a urea linkage, NH-CO-NH, to replace the gamma-glutamyl peptide bond. Thus, the target compound, gamma-(L-gamma-azaglutamyl)-S-(p-bromobenzyl)-L-cysteinylglycine 6, was a potent inhibitor of glyoxalase I with almost no loss of activity when compared to PBBG. However, unlike PBBG, 6 was completely resistant to enzymatic degradation by kidney homogenate or by purified gamma-glutamyltranspeptidase enzyme.
Influence of interface sink strength on the reduction of radiation-induced defect concentrations and fluxes in materials with large interface area per unit volume

We use a reaction-diffusion model to demonstrate that buried interfaces in polycrystalline composites simultaneously reduce both the concentrations and the fluxes of radiation-induced defects. The steady-state radiation-induced defect concentrations, however, are highly sensitive to the interface sink strength {eta}. Materials containing a large volume fraction of interfaces may therefore be resistant to multiple forms of radiation-induced degradation, such as swelling and hardening, as well as to embrittlement by solute segregation, provided that the interfaces have suitable {eta} values.
Physiologic trend detection and artifact rejection: a parallel implementation of a multi-state Kalman filtering algorithm.

Abstract Using a parallel implementation of the multi-state Kalman filtering algorithm, we have developed an accurate method of reliably detecting and identifying trends, abrupt changes, and artifacts from multiple physiologic data streams in real-time. The Kalman filter algorithm was implemented within an innovative software architecture for parallel computation: a parallel trecess trellis. Examples, processed in real-time, of both simulated and actual data serve to illustrate the potential value of the Kalman filter as a tool in physiologic monitoring.
Grain Carriers of Isotopic Anomalies

The dynamics of grain motion through gas are examined in terms of the injection of isotopically anomalous (compared to solar abundances) material into the early solar nebula. Calculations indicate that the injected grains cannot penetrate to the center of any of a range of reasonable configurations, suggesting the formation of an edge region enriched in injected material. Furthermore, the dynamical behavior of grains in turbulent flows indicates that pockets of grains can have some resistance to turbulent diffusion. The constraints developed here are used to delineate a set of consistent, injected-grain models for the origin of the isotopic anomalies in meteorite inclusions.
STRUCTURE OF THE COMPRESSIBLE TURBULENT SHEAR LAYER

The large-scale structure of the turbulent compressible shear layer is investigated in a two-stream supersonic wind tunnel. Double-exposure schlieren photography reveals that the two convective Mach numbers, corresponding to each side of the shear layer, are very different: one is sonic or supersonic and the other is low subsonic. This contradicts the current isentropic large-scale-structure model, which predicts the convective Mach numbers to be equal or very close. It is speculated that effects of shock waves are responsible for these asymmetries.
THE MID-INFRARED LUMINOSITIES OF NORMAL GALAXIES OVER COSMIC TIME

Modern population synthesis models estimate that 50% of the rest-frame K-band light is produced by thermally pulsing asymptotic giant branch (TP-AGB) stars during the first Gyr of a stellar population, with a substantial fraction continuing to be produced by the TP-AGB over a Hubble time. Between 0.2 and 1.5 Gyr, intermediate-mass stars evolve into TP-AGB C stars which, due to significant amounts of circumstellar dust, emit half their energy in the mid-IR. We combine these results using published mid-IR colors of Galactic TP-AGB M and C stars to construct simple models for exploring the contribution of the TP-AGB to 24 μm data as a function of stellar population age. We compare these empirical models with an ensemble of galaxies in the Chandra Deep Field South from z = 0 to z = 2, and with high-quality imaging in M81. Within the uncertainties, the TP-AGB appears responsible for a substantial fraction of the mid-IR luminosities of galaxies from z = 0 to z = 2, the maximum redshift to which we can test our hypothesis, while, at the same time, our models reproduce much of the detailed structure observed in mid-IR imaging of M81. The mid-IR is a good diagnostic of star formation over timescales of ~1.5 Gyr, but this implies that ongoing star formation rates at z = 1 may be overestimated by factors of ~1.5-6, depending on the nature of star formation events. Our results, if confirmed through subsequent work, have strong implications for the star formation rate density of the universe and the growth of stellar mass over time.
Broadband Phase-Coherent Optical Frequency Synthesis With Actively Linked Ti:Sapphire and Cr:Forsterite Femtosecond Lasers

Extremely broadband femtosecond pulse sources with well defined carrier-envelope phase evolution have been a field of intense research over the past years [1–3]. The time-domain motivation for the push towards increased bandwidth is the generation of optical pulses that approach the single-cycle regime and can be used for phase-sensitive nonlinear experiments [4]. The frequency-domain motivation is the interest in extending the bandwidth over which optical frequencies can be precisely synthesized and subsequently used for absolute optical frequency measurements or comparisons [1, 5, 6]. Nonlinear frequency conversion is one route to overcome the bandwidth limitations of current systems based on one femtosecond laser. A second attractive route is linking two femtosecond lasers with overlapping emission spectra. Phase-locking the repetition rates of two femtosecond lasers with different gain media has recently been demonstrated. Here, we use a Ti:sapphire laser and a Cr:forsterite laser to extend this approach and additionally equalize the rate at which the carrier-waves move underneath their pulse envelopes. In other words, we link the absolute position of the two frequency combs, thereby establishing a true phase-coherence between all modes of their combined spectrum. The laser repetition rates are phase-locked by using a nonlinear cross-correlation technique.
Demonstration of a phosphazirconocene as a catalyst for the ring opening of epoxides with TMSCl.

In this study, it was demonstrated for the first time that a phosphazirconocene catalyzes the ring opening of epoxides with TMSCl. This reactivity leads to a facile preparation of chlorohydrins. The late transition metal Fe analogue was found to catalyze the reaction at rates and stereoselectivity comparable to those of the Zr complex.
A process-based, distributed hydrologic model based on a large-scale method for surface–subsurface coupling

Abstract Process-based watershed models are useful tools for understanding the impacts of natural and anthropogenic influences on water resources and for predicting water and solute fluxes exported from watersheds to receiving water bodies. The applicability of process-based hydrologic models has been previously limited to small catchments and short time frames. Computational demands, especially the solution to the three-dimensional subsurface flow domain, continue to pose significant constraints. This paper documents the mathematical development, numerical testing and the initial application of a new distributed hydrologic model PAWS (Process-based Adaptive Watershed Simulator). The model solves the governing equations for the major hydrologic processes efficiently so that large scale applications become relevant. PAWS evaluates the integrated hydrologic response of the surface–subsurface system using a novel non-iterative method that couples runoff and groundwater flow to vadose zone processes approximating the 3D Richards equation. The method is computationally efficient and produces physically consistent solutions. All flow components have been independently verified using analytical solutions and experimental data where applicable. The model is applied to a medium-sized watershed in Michigan (1169 km2) achieving high performance metrics in terms of streamflow prediction at two gages during the calibration and verification periods. PAWS uses public databases as input and possesses full capability to interact with GIS datasets. Future papers will describe applications to other watersheds and the development and application of fate and transport modules.
Understanding the effectiveness of computer graphics for decision support: a cumulative experimental approach

A total of 840 junior and senior-level undergraduate business students particpated in three experiments that compared computer-generated graphical forms of data presentation to traditional tabular reports. The first experiment compared tables and bar charts for their effects on readability, interpretation accuracy, and decision making. No differences in interpretation accuracy or decision quality were observed for the two groups, although tabular reports were rated as "easier to read and understand" than graphical reports. The second experiment compared line plots to tables for their effects on interpretation accuracy and decision quality. Subjects with graphical reports outperformed those with tables. There were no meaningful differences in interpretation accuracy across treatment groups. The third experiment compared graphical and tabular reports for their ability to convey a "message" to the reader. Only in situations in which a vast amount of information was presented and relatively simple impressions were to be made, did subjects given graphs outperform those using tables.This program of cumulative experiments indicates that generalized claims of superiority of graphic presentation are unsupported, at least for decision-related activities. In fact, the experiments suggest that the effectiveness of the data display format is largely a function of the characteristics of the task at hand, and that impressions gleaned from "one shot" studies of the effectiveness of the use of graphs may be nothing more than situationally dependent artifacts.
AGN-driven Convection in Galaxy-Cluster Plasmas

This paper describes how active galactic nuclei can heat galaxy-cluster plasmas by driving convection in the intracluster medium. A model is proposed in which a central supermassive black hole accretes intracluster plasma at the Bondi rate Bondi and powers a radio source. The central radio source produces cosmic rays, which mix into the thermal plasma. The cosmic-ray luminosity Lcr is ∝Bondic2. The cosmic-ray pressure gradient drives convection, which causes plasma heating. It is assumed that plasma heating balances radiative cooling. The plasma heating rate is self-regulating because Bondi is a decreasing function of the specific entropy near the cluster center s0; if heating exceeds cooling, then s0 increases, Bondi and Lcr decrease, and the convective heating rate is reduced. This paper focuses on the role of intracluster magnetic fields, which affect convection by causing heat and cosmic rays to diffuse primarily along magnetic field lines. A new stability criterion is derived for convection in a thermal-plasma/cosmic-ray fluid, and equations for the average fluid properties in a convective cluster are obtained with the use of a nonlocal two-fluid mixing-length theory. Numerical solutions of the model equations compare reasonably well with observations without requiring fine-tuning of the model parameters.
Galaxy harassment and the evolution of clusters of galaxies

NEARBY clusters of galaxies are filled with red elliptical 'E' and lenticular 'SO' galaxies1, while younger clusters (at redshifts of ≳ 0.4) contain substantial populations of blue spiral galaxies with morphological peculiarities2–7 (see Fig. 1). Thus, within the last 4–5 billion years, galaxies in clusters underwent strong evolution that completely changed their character. By contrast, galaxies that are not associated with clusters show far less morphological evolution8. Here we propose that multiple highspeed encounters between galaxies—'galaxy harassment'— drives the morphological evolution in clusters. Our simulations show that these encounters are very different from mergers; they transform small disk galaxies into dwarf elliptical or dwarf spheroidal galaxies. Harassment will leave detectable debris arcs and could provide fuel for quasars in sub-luminous host galaxies.
Structure of Pseudocerosine, an Indolic Azafulvene Alkaloid from the Flatworm Pseudoceros indicus

The rim of the tunic of the flatworm Pseudoceros indicus is characterized by blue dots on a white background. The isolation and structure elucidation of the blue pigment is reported. It is shown by extensive analysis of spectroscopic data to be an indolic azafulvene, which has been named pseudocerosine.
Shell Modeling of Fretting in Riveted Lap Joints

Fretting is a contact damage mechanism arising from microslip associated with small-scale oscillatory motion of nominally clamped structural members. Fretting has heen ohserved near aircraft skin fastener holes. Shell finite elements are used to model the contact at a typical skin/rivet interface, with emphasis on fretting as a crack nucleation mechanism. Contact elements implementing the Coulomh friction law keep track of contact status between interacting surfaces. The model accounts for bending, contact hetween the skin panels, and rivet head clamping pressure. Elastic supports control the load transferred and simulate various rivet configurations. No interference is considered, leading to loss of contact between the skin and rivet on loading. The distinct stick-slip zones, combined with high tensile stresses at the edge of contact, are indicative of fretting, resulting in crack nucleation at the edge of contact. Away from the edge of contact, the tensile stress decays rapidly. The slip displacement has values typically associated with fretting fatigue. The interface between the two skin panels is also a region of fretting damage. Crack nucleation lives are predicted using a multiaxial fatigue theory. The top row of rivets has the smallest predicted life. For low remote stresses, increase in friction coefficient increases life, whereas for high remote stresses, life decreases with increase in coefficient of friction. Increasing rivet head clamping pressure increases the life. Plasticity blunts the effects of friction coefficient and clamping pressure. An approximate solution that does not require finite element analysis estimates the crack nucleation life for any rivet configuration quickly.
Phase Current Reconstruction for AC Motor Drives Using a DC Link Single Current Sensor and Measurement Voltage Vectors

Three-phase current measurement using only a single current sensor in the inverter dc link is appealing for ac motor drives because it minimizes the number of current sensors, thereby reducing sensor cost, weight, and volume. However, the basic dc link single current sensor technique poses special challenges because the duration of the active voltage vectors must be long enough to measure the dc link current reliably during every pulsewidth modulation switching interval. A new single current sensor algorithm for reconstructing the phase currents called the measurement vector insertion method (MVIM) is presented that overcomes this problem using active voltage vectors that are applied for brief measurement intervals only when needed during each fundamental frequency cycle. The insertion of measurement vectors makes it possible to reconstruct the output phase currents with minimum impact on the machine's performance and operating envelope. A combination of analytical and experimental results is provided to confirm that the MVIM algorithm offers attractive phase current reconstruction performance in comparison to alternative dc link single current sensor algorithms
Nearly-second-order nematic-isotropic phase transition in a cyclic thermotropic liquid crystal

Kerr measurements are reported for a cyclic trimeric liquid crystal above the uniaxial nematic-isotropic phase transition temperature ${\mathit{T}}_{\mathit{N}\mathit{I}}$. The inverse of the order-parameter susceptibility is found to be linear in temperature, such that the quantity ${\mathit{T}}_{\mathit{N}\mathit{I}}$-${\mathit{T}}^{\mathrm{*}}$ is less than 200 mK, where ${\mathit{T}}^{\mathrm{*}}$ is the supercooling limit of the isotropic phase. Well below ${\mathit{T}}_{\mathit{N}\mathit{I}}$ we observe textures consistent with a biaxial nematic phase.
New hysteresis operators with applications to counterterrorism

Abstract We define two models of hysteresis that generalize the Preisach model. The first model is deterministic, the second model is stochastic and it utilizes discontinuous transition probabilities that satisfy impulsive differential equations. For the first model we prove, among other things, a local version of the “wiping out” property; for the stochastic model, we give methods for the construction of solutions of impulsive differential equations that determine the discontinuous transition probabilities. We also present a game-theoretic problem utilizing a generalized hysteresis operator. These hysteresis operators are motivated by questions of modelling the dynamics of decision making processes of networks of loosely knit terrorist groups.
Some remarks about induced QCD

Abstract Migdal and Kazakov have suggested that lattice QCD with an adjoint representation scalar in the infinite coupling limit could induce QCD. I find an exact saddlepoint of this theory for infinite N in the case of a quadratic scalar potential. I discuss some aspects of this solution and also show how the continuum D = 1 matrix model with an arbitrary potential can be reproduced through this approach.
Effects of Strong Magnetic Fields in Strange Baryonic Matter

Abstract We investigate the effects of very strong magnetic fields upon the equation of state of dense baryonic matter in which hyperons are present. In the presence of a magnetic field, the equation of state above nuclear density is significantly affected both by Landau quantization and magnetic moment interactions, but only for field strengths B >5×10 18 G. The former tends to soften the EOS and increase proton and lepton abundances, while the latter produces an overall stiffening of the EOS. Each results in a suppression of hyperons relative to the field-free case. The structure of a neutron star is, however, primarily determined by the magnetic field stress. We utilize existing general relativistic magneto-hydrostatic calculations to demonstrate that maximum average fields within a stable neutron are limited to values B ⩽1–3×10 18 G. This is not large enough to significantly influence particle compositions or the matter pressure, unless fluctuations dominate the average field strengths in the interior or configurations with significantly larger field gradients are considered.
Testing limits to policy reversal: Evidence from Indian privatizations.

Abstract We examine the effect of regime change on privatization. In the 2004 Indian election, the pro-reform BJP was unexpectedly defeated by a less reformist coalition. Stock prices of government-controlled companies that had been slated for privatization by the BJP dropped 3.5% relative to private firms. Government-controlled companies that were under study for possible privatization fell 7.5% relative to private firms. This is consistent with investor belief of a “point of no return,” where advanced reforms are more difficult to reverse. Further analysis suggests that layoffs, combined with the privatization announcement, served as a credible commitment to privatize.
The broadband digital divide and the economic benefits of mobile broadband for rural areas

Broadband is becoming increasingly important to national economies and the personal lives of users. However, broadband availability and adoption are not diffusing in rural and urban areas at the same rates. This article updates the rural broadband digital divide, with special attention paid to mobility. Empirical estimations of broadband provision and usage in the US show that rural areas have fewer high-speed fixed and mobile providers but more slower-speed fixed providers than urban areas. While rural availability of mobile broadband is lower than in urban areas, it still helps fill in gaps in fixed broadband coverage in rural areas. The rural gap in fixed broadband usage remains, but the mobile broadband usage gap disappears after controlling for household demographics. The raw broadband usage gaps between rural and urban households are proportionally greater for low-income households. The potential for mobile broadband to benefit rural areas through economic development is also examined.
String unification and leptophobic Z′ in flipped SU(5)

We summarize recent developments in the prediction for α s ( M z ), self-consistent string unification and the dynamical determination of mass scales, and leptophobic Z′ gauge bosons in the context of stringy flipped SU(5).
Slow, intermediate and fast dynamics in condensed matter

Abstract As is well-known, in gas dynamics there are three levels of descriptions: microscopic, mesoscopic and macroscopic. The corresponding equations are: Liouville, Boltzmann, and hydrodynamic equations, respectively. The difficulty of condensed matter such as classical liquids is general absence of well-defined mesoscopic level of description which is a scaffold so to speak enabling us to jump from microscopic to macroscopic descriptions. However, there are certain circumstances in which this is possible as we illustrate for critical dynamics and phase ordering kinetics.
Scope of the Suzuki−Miyaura Cross-Coupling Reaction of Potassium Trifluoroboratoketohomoenolates

Potassium trifluoroboratoketohomoenolates were prepared in good yields from either the corresponding α,β-unsaturated compounds or methyl ketones. These organoboron reagents were effectively cross-coupled with various aryl and heteroaryl chlorides.
Dynamical Masses for Low-Mass Pre-Main-Sequence Stars: A Preliminary Physical Orbit for HD 98800 B

We report on Keck Interferometer observations of the double-lined binary (B) component of the quadruple pre-main-sequence (PMS) system HD 98800. With these interferometric observations, combined with astrometric measurements made by the Hubble Space Telescope (HST) Fine Guidance Sensors (FGS) and published radial velocity observations, we have estimated preliminary visual and physical orbits of the HD 98800 B subsystem. Our orbit model calls for an inclination of 668 ± 32 and allows us to infer the masses and luminosities of the individual components. In particular we find component masses of 0.699 ± 0.064 and 0.582 ± 0.051 M☉ for the Ba (primary) and Bb (secondary) components, respectively. Spectral energy distribution (SED) modeling of the B subsystem suggests that the B circumstellar material is a source of extinction along the line of sight to the B components. This seems to corroborate a conjecture by Tokovinin that the B subsystem is viewed through circumbinary material, but it raises important questions about the morphology of that circumbinary material. Our modeling of the subsystem component SEDs finds temperatures and luminosities in agreement with previous studies, and coupled with the component mass estimates allows for comparison with PMS models in the low-mass regime with few empirical constraints. Solar abundance models seem to underpredict the inferred component temperatures and luminosities, while assuming slightly subsolar abundances brings the models and observations into better agreement. The current preliminary orbit does not yet place significant constraints on existing PMS stellar models, but prospects for additional observations improving the orbit model and component parameters are very good.
Diffusion of 2,2,6,6-tetramethylpiperidine 1-oxyl derivatives of variable hydrophobicity in tropocollagen I solution.

Abstract Electrochemical time-of-flight was used to measure the diffusion coefficients of 2,2,6,6-tetramethylpiperidine 1-oxyl derivatives, C n TPA, (3 to 7 CH 2 groups), in tropocollagen I solution, as a function of the chain length and the cross-linking with glutaraldehyde. The values of the diffusion coefficient of C n TPA in pure aqueous electrolyte follow the Stokes–Einstein law, i.e. the diffusion coefficient is inversely proportional to the size of the redox probe. Different behavior is observed in 0.5% (w/v) tropocollagen solution where the molecules with longer alkyl chains show larger diffusion coefficients than the smaller molecules. This behavior is explained in terms of electrostatic interactions between tropocollagen chains and the C n TPA molecules. The measurements of the diffusion coefficients of C n TPA in 0.5% tropocollagen cross-linked with glutaraldehyde indicate that while the C 7 TPA and C 5 TPA probes exhibit lower diffusion coefficients upon addition of 0.05% GA and 0.1% (v/v) GA respectively, the other C n TPA molecules exhibit either unchanged or increased diffusion coefficients under the same conditions thus indicating the presence of hydrophobic pockets selectively interacting with C n TPAs. These results demonstrate the utility of electrochemical time-of-flight in measurements of diffusion coefficients in complex biopolymeric media.
First total synthesis of isoprostane IPF2α-III

Abstract The first total synthesis of IPF2α-III, a type III isoprostane is described using a syn-anti-syn lactone 34 prepared from D-glucose and a novel iodohydrin synthon 30. This is first synthesis of a representative of type III isoprostane which is anticipated to be formed in vivo from arachidonic acid by free-radical mechanism. This synthetic material will help elucidate the formation in vivo of type III isoprostanes.
A Standing-Wave Microstrip Array Antenna

The design and analysis of a single-layer standing-wave microstrip array antenna are presented. No quarter-wave transformers or power dividers are present in the design. The main emphasis of this paper is on the multiple reflections in the feedline causing a standing-wave of a higher-order mode. As in the radiating patches of the array, the feedline resonates as well. So the array is treated as an arbitrarily-shaped microstrip antenna and the generalized cavity model is applied for analysis due to its simplicity and physical insight. The accuracy of the model is verified by simulation and experiment. Spurious radiations and manufacturing difficulties can be minimized in such single-layer standing-wave designs when compared to corporate-fed traveling-wave structures. The scheme offers good potential for building large arrays for high-gain applications.
Primer Vector Theory Applied to Global Low-Thrust Trade Studies

The low-thrust spacecraft trajectory problem can be reduced to only a few parameters using calculus of variations and the well-known primer vector theory. This low dimensionality combined with the extraordinary speed of modern computers allows for rapid exploration of the parameter space and invites opportunities for global optimization. Accordingly, a general low-thrust trade analysis tool is developed based on a global search for local indirect method solutions. An efficient propagator is implemented with an implicit "bang-bang" thrusting structure that accommodates an a priori unknown number of switching times. An extension to the standard adjoint control transformation is introduced that provides additional physical insight and control over the anticipated evolution of the thrust profile. The uniformly random search enjoys a perfect linear speedup for parallel implementation. The method is applied specifically on multi revolution transfers in the Jupiter-Europa and Earth-moon restricted three body problems. In both cases, thousands of solutions are found in a single parallel run. The result is a global front of Pareto optimal solutions across the competing objectives of flight time and final mass.
Subgroups of Inertia Groups Arising from Abelian Varieties

Abstract Given an abelian variety over a field with a discrete valuation, Grothendieck defined a certain open normal subgroup of the absolute inertia group. This subgroup encodes information on the extensions over which the abelian variety acquires semistable reduction. We study this subgroup, and use it to obtain information on the extensions over which the abelian variety acquires semistable reduction.
Chemical Inhomogeneities in the Milky Way Stellar Halo

We have compiled a sample of 699 stars from the recent literature with detailed chemical abundance information (spanning ?4.2 [Fe/H] +0.3), and we compute their space velocities and Galactic orbital parameters. We identify members of the inner and outer stellar halo populations in our sample based only on their kinematic properties and then compare the abundance ratios of these populations as a function of [Fe/H]. In the metallicity range where the two populations overlap (?2.5 [Fe/H] ?1.5), the mean [Mg/Fe] of the outer halo is lower than the inner halo by ?0.1 dex. For [Ni/Fe] and [Ba/Fe], the star-to-star abundance scatter of the inner halo is consistently smaller than in the outer halo. The [Na/Fe], [Y/Fe], [Ca/Fe], and [Ti/Fe] ratios of both populations show similar means and levels of scatter. Our inner halo population is chemically homogeneous, suggesting that a significant fraction of the Milky Way stellar halo originated from a well-mixed interstellar medium. In contrast, our outer halo population is chemically diverse, suggesting that another significant fraction of the Milky Way stellar halo formed in remote regions where chemical enrichment was dominated by local supernova events. We find no abundance trends with maximum radial distance from the Galactic center or maximum vertical distance from the Galactic disk. We also find no common kinematic signature for groups of metal-poor stars with peculiar abundance patters, such as the ?-poor stars or stars showing unique neutron-capture enrichment patterns. Several stars and dwarf spheroidal systems with unique abundance patterns spend the majority of their time in the distant regions of the Milky Way stellar halo, suggesting that the true outer halo of the Galaxy may have little resemblance to the local stellar halo.
Affine descents and the Steinberg torus

Let [email protected]?L be an irreducible affine Weyl group with Coxeter complex @S, where W denotes the associated finite Weyl group and L the translation subgroup. The Steinberg torus is the Boolean cell complex obtained by taking the quotient of @S by the lattice L. We show that the ordinary and flag h-polynomials of the Steinberg torus (with the empty face deleted) are generating functions over W for a descent-like statistic first studied by Cellini. We also show that the ordinary h-polynomial has a nonnegative @c-vector, and hence, symmetric and unimodal coefficients. In the classical cases, we also provide expansions, identities, and generating functions for the h-polynomials of Steinberg tori.
Identifying isotropic events using a regional moment tensor inversion

[1] We calculate the deviatoric and isotropic source components for 17 explosions at the Nevada Test Site, as well as 12 earthquakes and 3 collapses in the surrounding region of the western United States, using a regional time domain full waveform inversion for the complete moment tensor. The events separate into specific populations according to their deviation from a pure double-couple and ratio of isotropic to deviatoric energy. The separation allows for anomalous event identification and discrimination between explosions, earthquakes, and collapses. Confidence regions of the model parameters are estimated from the data misfit by assuming normally distributed parameter values. We investigate the sensitivity of the resolved parameters of an explosion to imperfect Earth models, inaccurate event depths, and data with low signal-to-noise ratio (SNR) assuming a reasonable azimuthal distribution of stations. In the band of interest (0.02–0.10 Hz) the source-type calculated from complete moment tensor inversion is insensitive to velocity model perturbations that cause less than a half-cycle shift (<5 s) in arrival time error if shifting of the waveforms is allowed. The explosion source-type is insensitive to an incorrect depth assumption (for a true depth of 1 km), and the goodness of fit of the inversion result cannot be used to resolve the true depth of the explosion. Noise degrades the explosive character of the result, and a good fit and accurate result are obtained when the signal-to-noise ratio is greater than 5. We assess the depth and frequency dependence upon the resolved explosive moment. As the depth decreases from 1 km to 200 m, the isotropic moment is no longer accurately resolved and is in error between 50 and 200%. However, even at the most shallow depth the resultant moment tensor is dominated by the explosive component when the data have a good SNR.
Two-qubit separabilities as piecewise continuous functions of maximal concurrence

The generic real (β = 1) and complex (β = 2) two-qubit states are 9-dimensional and 15-dimensional in nature, respectively. The total volumes of the spaces they occupy with respect to the Hilbert-Schmidt and Bures metrics are obtainable as special cases of formulae of Źyczkowski and Sommers. We claim that if one could determine certain metric-independent three-dimensional 'eigenvalue-parameterized separability functions' (EPSFs), S (1,β) 4 (λ 1 ... λ 4 ), then these formulae could be readily modified so as to yield the Hilbert-Schmidt and Bures volumes occupied by only the separable two-qubit states (and hence associated separability probabilities). Motivated by analogous earlier analyses of 'diagonal-entry-parameterized separability functions', we further explore the possibility that such three-dimensional EPSFs might, in turn, be expressible as univariate functions of some special relevant variable-which we hypothesize to be the maximal concurrence (0 ≤ C ≤ 1) over spectral orbits. Extensive numerical results that we obtain are rather closely supportive of this hypothesis. Both the real and complex estimated EPSFs exhibit clearly pronounced jumps of magnitude roughly 50% at C = 1/2, as well as a number of additional matching discontinuities.
RULING OUT POSSIBLE SECONDARY STARS TO EXOPLANET HOST STARS USING THE CHARA ARRAY

Of the over 450 exoplanets known to date, more than 420 of them have been discovered using radial velocity studies, a method that tells nothing about the inclination of the planet's orbit. Because it is more likely that the companion is a planetary-mass object in a moderate- to high-inclination orbit than a low-mass stellar object in a nearly face-on orbit, the secondary bodies are presumed to be planets. Interferometric observations allow us to inspect the angular diameter fit residuals to calibrated visibilities in order to rule out the possibility of a low-mass stellar companion in a very low-inclination orbit. We used the Center for High Angular Resolution Astronomy Array interferometer to observe 20 exoplanet host stars and considered five potential secondary spectral types: G5 V, K0 V, K5 V, M0 V, and M5 V. If a secondary star is present and is sufficiently bright, the effects of the added light will appear in interferometric observations where the planet will not. All secondary types could be eliminated from consideration for seven host stars and no secondary stars of any spectral type could be ruled out for seven more. The remaining six host stars showed a range of possible secondary types.
Octupole excitations in O(6) nuclei

Abstract The coupling is discussed of an octupole boson to an O(6) core in the interacting boson approximation, and the results are applied to several platinum isotopes.
Worlds as a unifying element of knowledge representation

Abstract Computational systems with the abilities of human biological intelligence must be able to reason about the beliefs of others, hypothetical and future situations, quantifiers, probabilities, and counterfactuals. While each of these deals in some way with reasoning about alternative states of reality, no single knowledge representation framework deals with them in a unified and scalable manner. As a consequence it is difficult to build cognitive systems for domains that require each of these abilities to be used together. To enable this integration we propose a representational framework based on synchronizing beliefs between worlds. This framework is consistent with evidence that performing mental simulations of the world is a ubiquitous aspect of human intelligence. Using this framework, each of these tasks can be reformulated into a reasoning problem involving worlds. This demonstrates that the notions of worlds and inheritance can bring significant parsimony and broad new abilities to knowledge representation.
Response to marijuana as a function of potency and breathhold duration.

The present study examined the effects of systematic manipulation of breathhold duration (0 and 20 s) on the physiological and subjective response to active (M; 2.3% delta-9-THC) and placebo (P; 0.0% delta-9-THC) marijuana in a group of ten regular marijuana smokers. During the eight-session experiment, subjects were exposed twice to each of four experimental conditions (P0, P20, M0, M20), scheduled according to a randomized block design. A controlled smoking procedure was used in which the number of puffs and puff volume were held constant. Expired-air carbon monoxide (CO) levels were used to monitor smoke intake. Breathhold duration affected CO absorption; significantly more CO was absorbed from both P and M smoke after 20 s of breathholding (mean CO boost=6.9 ppm) than after no breathholding (mean=4.4 ppm). Heart rate was minimally affected by the breathhold manipulation. Effects of marijuana on mood were not consistently affected by breathhold duration. The results confirm previous findings that prolonged breathholding does not substantially enhance the effects of inhaled marijuana smoke.
A Future High Statistics Charm Mixing Experiment Using the Fermilab Tevatron

We present an idea for a future D 0 – D ¯ 0 mixing and CP violation experiment to run at the Fermilab Tevatron. We estimate that in three years of running, such an experiment could reconstruct an order of magnitude more flavor-tagged D 0 → K + π − decays than will be reconstructed by the B -factory experiments with their full data sets. The resulting sensitivity to CP -violating parameters | q / p | and Arg ( q / p ) is calculated from a global fit to CP -violating observables, and it is found to be much greater than current world sensitivity.
Characterization of nuclear physics targets using Rutherford backscattering and particle induced X-ray emission

Abstract Rutherford backscattering and particle induced X-ray emission have been utilized to precisely characterize targets used in nuclear fission experiments. The method allows for a fast and non-destructive determination of target thickness, homogeneity and element composition.
Galaxy-scale star formation on the red sequence: The continued growth of S0s and the quiescence of ellipticals

This paper examines star formation (SF) in relatively massive, primarily early-type galaxies (ETGs) at z {approx} 0.1. A sample is drawn from bulge-dominated Galaxy Evolution Explorer/Sloan Digital Sky Survey (GALEX/SDSS) galaxies on the optical red sequence with strong UV excess and yet quiescent SDSS spectra. High-resolution far-UV imaging of 27 such ETGs using Hubble Space Telescope Advanced Camera for Surveys/Solar Blind Channel (ACS/SBC) reveals structured UV morphology in 93% of the sample, consistent with low-level ongoing SF ({approx}0.5 M{sub Sun} yr{sup -1}). In 3/4 of the sample the SF is extended on galaxy scales (25-75 kpc), while the rest contains smaller (5-15 kpc) SF patches in the vicinity of an ETG-presumably gas-rich satellites being disrupted. Optical imaging reveals that all ETGs with galaxy-scale SF in our sample have old stellar disks (mostly S0 type). None is classified as a true elliptical. In our sample, galaxy-scale SF takes the form of UV rings of varying sizes and morphologies. For the majority of such objects we conclude that the gas needed to fuel current SF has been accreted from the intergalactic medium, probably in a prolonged, quasi-static manner, leading in some cases to additional disk buildup. The remaining ETGs with galaxy-scale SFmore » have UV and optical morphologies consistent with minor merger-driven SF or with the final stages of SF in fading spirals. Our analysis excludes that all recent SF on the red sequence resulted from gas-rich mergers. We find further evidence that galaxy-scale SF is almost exclusively an S0 phenomenon ({approx}20% S0s have SF) by examining the overall optically red SDSS ETGs. Conclusion is that significant number of field S0s maintain or resume low-level SF because the preventive feedback is not in place or is intermittent. True ellipticals, on the other hand, stay entirely quiescent even in the field.« less
Practical asymmetric syntheses of all four 2,3-methanoleucine stereoisomers

Abstract All four stereoisomers of the 2,3-methanoamino acids BOC-E-cyclo-Leu and BOC-Z-cyclo-Leu were prepared from the optically active diol 4 (and its enantiomer) derived from valine. The challenges associated with introducing protected amine functionalities cis to the side chain were overcome by using the vinylogous malonate synthon, dimethyl gluconate.
Methods to enable the design of bioactive small molecules targeting RNA

RNA is an immensely important target for small molecule therapeutics or chemical probes of function. However, methods that identify, annotate, and optimize RNA-small molecule interactions that could enable the design of compounds that modulate RNA function are in their infancies. This review describes recent approaches that have been developed to understand and optimize RNA motif-small molecule interactions, including structure-activity relationships through sequencing (StARTS), quantitative structure-activity relationships (QSAR), chemical similarity searching, structure-based design and docking, and molecular dynamics (MD) simulations. Case studies described include the design of small molecules targeting RNA expansions, the bacterial A-site, viral RNAs, and telomerase RNA. These approaches can be combined to afford a synergistic method to exploit the myriad of RNA targets in the transcriptome.
APPLICATION OF LUMPED-SYSTEM ANALYSIS TO LAYERED POROUS CAVITIES HEATED FROM BELOW

A numerical study has been performed to further investigate the flow and temperature fields in layered porous cavity. The geometry considered is a square cavity with 2 or 4 sublayers and is heated from below. The results obtained are usetl to further evaluate the feasibility of using the 1umpec.-system analysis for heat transfer in layered porous cavities as proposed in the previous study. To this end, the effective permeabilities based on the arithmetic and harmonic averaging schemes are examined for their use in the conjunction with the lumped-system analy5,is. Nomenclature aspect ratio, A = H/L heat capacity, [J/kg.K] gravitational acceleraticw [rn/s2] height of cavity, [m] location of the interface of horizontal sublayers, [ml permeability, [m2] permeability ratio, K = K2/KI effective permeability of horizontal layers, [m2] effective permeability of vertical layers, [m2] effective thermal condu:tivity of porous medium, [W/m.K] width of cavity, [m] location of the interfaze of vertical sublayers,
Solid phase synthesis of complex natural products and libraries thereof.

Natural products have served as an important source of medicinal compounds and pharmaceutical leads over the last century. Within the last 10 years, significant interest has developed in applying combinatorial chemistry techniques to the study of natural products and their biological activities. In this review, we examine several representative efforts wherein natural product skeletons have been constructed or immobilized on solid support and subsequently derivatized, giving rise to analog libraries useful in understanding the structure-activity relationships of the parent natural product. Issues such as target selection, library design, linker development, automation, and library characterization are addressed.