cssi/SciSciGPT-SciSciNet huggingface dataset:
Chiral Flavor Violation from Extended Gauge Mediation

Models of extended gauge mediation, in which large A-terms arise through direct messenger-MSSM superpotential couplings, are well-motivated by the discovery of the 125 GeV Higgs. However, since these models are not necessarily MFV, the flavor constraints could be stringent. In this paper, we perform the first detailed and quantitative study of the flavor violation in these models. To facilitate our study, we introduce a new tool called FormFlavor for computing precision flavor observables in the general MSSM. We validate FormFlavor and our qualitative understanding of the flavor violation in these models by comparing against analytical expressions. Despite being non-MFV, we show that these models are protected against the strongest constraints by a special flavor texture, which we dub chiral flavor violation (χFV). This results in only mild bounds from current experiments, and exciting prospects for experiments in the near future.
Better knowledge with social media? Exploring the roles of social capital and organizational knowledge management

Purpose – The purpose of this paper is to explore social media’s impact on organizational knowledge quality through the theoretical lens of social capital and resource exchange. Design/methodology/approach – This is a theory-confirming, quantitative study using panel data collected through a Web-based survey. Findings – The results show that while social media affects structural capital and cognitive capital directly, it only affects relational capital indirectly through structural and cognitive capital. Moreover, overall social media and the enhanced social capital do help promote organizational efforts in knowledge management, which subsequently leads to a higher level of organizational knowledge quality. Research limitations/implications – All survey respondents were from the USA, which may limit the generalizability of the findings. The authors also call for more research in establishing the time sequence in the proposed causal relations and in the individual-level mechanism through which social media...
Simulator Evaluation of the Final Approach Spacing Tool

This paper describes the design and simulator evaluation of an automation tool for assisting terminal radar approach controllers in sequencing and spacing traffic onto the final approach course. The automation tool, referred to as the Final Approach Spacing Tool (FAST), displays speed and heading advisories for arrivals as well as sequencing information on the controller's radar display. The main functional elements of FAST are a scheduler that schedules and sequences the traffic, a 4D trajectory synthesizer that generates the advisories, and a graphical interface that displays the information to the controller. FAST has been implemented on a high performance workstation. It can be operated standalone in the Terminal Radar Approach Control (TRACON) Facility or as an element of a system integrated with automation tools in the Air Route Traffic Control Center (ARTCC). FAST was evaluated by experienced TRACON controllers in a realtime air traffic control simulaton. Simulation results summarized in the paper show that FAST significantly reduced controller workload and demonstrated a potential for an increase in landing rate.
An Equilibrium Model of the Term Structure of Interest Rates: Recursive Preferences at Play

In this paper we analyze the performance of an equilibrium model of the term structure of the interest rate under Epstein-Zin/Weil preferences in which consumption growth and inflation follow a VAR process with logistic stochastic volatility. We find that the model can successfully reproduce the first moment of yields and their persistence, but fails to reproduce their standard deviation. The filtered stochastic volatility is a good indicator of crises and shows high persistence, but it is not enough to generate a slowly decaying volatility of yields with respect to maturity. Preference parameters are estimated to be about 4 for the coefficient of relative risk aversion and infinity for the elasticity of intertemporal substitution.
A Concave Pairwise Fusion Approach to Subgroup Analysis

ABSTRACTAn important step in developing individualized treatment strategies is correct identification of subgroups of a heterogeneous population to allow specific treatment for each subgroup. This article considers the problem using samples drawn from a population consisting of subgroups with different mean values, along with certain covariates. We propose a penalized approach for subgroup analysis based on a regression model, in which heterogeneity is driven by unobserved latent factors and thus can be represented by using subject-specific intercepts. We apply concave penalty functions to pairwise differences of the intercepts. This procedure automatically divides the observations into subgroups. To implement the proposed approach, we develop an alternating direction method of multipliers algorithm with concave penalties and demonstrate its convergence. We also establish the theoretical properties of our proposed estimator and determine the order requirement of the minimal difference of signals between g...
Exact Hybrid Covariance Thresholding for Joint Graphical Lasso

This paper studies precision matrix estimation for multiple related Gaussian graphical models from a dataset consisting of different classes, based upon the formulation of this problem as group graphical lasso. In particular, this paper proposes a novel hybrid covariance thresholding algorithm that can effectively identify zero entries in the precision matrices and split a large joint graphical lasso problem into many small subproblems. Our hybrid covariance thresholding method is superior to existing uniform thresholding methods in that our method can split the precision matrix of each individual class using different partition schemes and thus, split group graphical lasso into much smaller subproblems, each of which can be solved very fast. This paper also establishes necessary and sufficient conditions for our hybrid covariance thresholding algorithm. Experimental results on both synthetic and real data validate the superior performance of our thresholding method over the others.
Solvent-like ligand-coated ultrasmall cadmium selenide nanocrystals: strong electronic coupling in a self-organized assembly

Strong inter-nanocrystal electronic coupling is a prerequisite for delocalization of exciton wave functions and high conductivity. We report 170 meV electronic coupling energy of short chain poly(ethylene glycol) thiolate-coated ultrasmall (<2.5 nm in diameter) CdSe semiconductor nanocrystals (SNCs) in solution. Cryo-transmission electron microscopy analysis showed the formation of a pearl-necklace assembly of nanocrystals in solution with regular inter-nanocrystal spacing. The electronic coupling was studied as a function of CdSe nanocrystal size where the smallest nanocrystals exhibited the largest coupling energy. The electronic coupling in spin-cast thin-film (<200 nm in thickness) of poly(ethylene glycol) thiolate-coated CdSe SNCs was studied as a function of annealing temperature, where an unprecedentedly large, ∼400 meV coupling energy was observed for 1.6 nm diameter SNCs, which were coated with a thin layer of poly(ethylene glycol) thiolates. Small-angle X-ray scattering measurements showed that CdSe SNCs maintained an order array inside the films. The strong electronic coupling of SNCs in a self-organized film could facilitate the large-scale production of highly efficient electronic materials for advanced optoelectronic device application.
The Three Characteristic Temperatures of Relaxor Dynamics and Their Meaning

In this report, we compare the temperature evolution of several physical properties of the relaxor systems, PZN, PMN and KTN. We show that three rather than two characteristic temperatures can be identified, T B , T* and T f , and discuss their meaning in light of dielectric, Raman and neutron scattering experimental results.
Analytic continuation for asymptotically AdS 3D gravity

We have previously proposed that asymptotically AdS 3D wormholes and black holes can be analytically continued to the Euclidean signature. The analytic continuation procedure was described for non-rotating spacetimes, for which a plane t = 0 of time symmetry exists. The resulting Euclidean manifolds turned out to be handlebodies whose boundary is the Schottky double of the geometry of the t = 0 plane. In the present paper we generalize this analytic continuation map to the case of rotating wormholes. The Euclidean manifolds we obtain are quotients of the hyperbolic space by a certain quasi-Fuchsian group. The group is the Fenchel–Nielsen deformation of the group of the non-rotating spacetime. The angular velocity of an asymptotic region is shown to be related to the Fenchel–Nielsen twist. This solves the problem of classification of rotating black holes and wormholes in (2 + 1) dimensions: the spacetimes are parametrized by the moduli of the boundary of the corresponding Euclidean spaces. We also comment on the thermodynamics of the wormhole spacetimes.
Synthesis and application of oxadiazines as chiral ligands for the enantioselective addition of diethylzinc to aldehydes

Abstract A series of oxadiazines derived from l -phenylalanine bearing phenolic substituents have been synthesized in a multistep, one pot process. This process involves the reaction of a mixed anhydride with a β-hydrazino alcohol, methanesulfonylation of the alcohol moiety, and base induced cyclization. The resultant oxadiazines were employed in the asymmetric addition of diethylzinc to aldehydes.
Calculation of the pulse-height response of NaI(Tl) scintillation counters

Abstract A Monte Carlo calculation to determine the pulse-height response of NaI(Tl) scintillation counters to gamma rays is described. Comparisons of several calculations with ecperiments using 3-in.-dia by 3-in.-high crystals for source energies from 0.32 to 7.48 MeV are presented and show good agreement at large pulse heights. At small pulse heights the calculations underestimate the experimental data and indicate that background radiation can contribute significantly to the experimental results. An extensive series of calculations are reported for a 3-in.-dia by 3-in.-high crystal using monoenergetic, point isotropic sources placed on the crystal axis 10 cm from one end. The source energy ranged from 0.1 to 6.0 MeV in this series of calculations.
HOW DO WE LOSE EXCITATION IN THE GREEN

Efficiency droop and green gap are terms that summarize performance limitations in GaInN/GaN high brightness light emitting diodes (LEDs). Here we summarize progress in the development of green LEDs and report on time resolved luminescence data of polar c-plane and non-polar m-plane material. We find that by rigorous reduction of structural defects in homoepitaxy on bulk GaN and V-defect suppression, higher efficiency at longer wavelengths becomes possible. We observe that the presence of donor acceptor pair recombination within the active region correlates with lower device performance. To evaluate the aspects of piezoelectric polarization we compare LED structures grown along polar and non-polar crystallographic axes. In contrast to the polar material we find single exponential luminescence decay and emission wavelengths that remain stable irrespective of the excitation density. Those findings render high prospects for overcoming green gap and droop in non-polar homoepitaxial growth.
Dynamics of Kicked and Accelerated Massive Black Holes in Galaxies

A study is made of the behavior of massive black holes in disk galaxies that have received an impulsive kick from a merger or a sustained acceleration from an asymmetric jet. The motion of the gas, stars, dark matter, and massive black hole are calculated using the GADGET-2 simulation code. The massive black hole escapes the galaxy for kick velocities above about 600 km s−1 or accelerations above about 4 × 10−8 cm s−2 over timescales of the order of 108 yr. For smaller velocity kicks or smaller accelerations, the black hole oscillates about the center of mass with a frequency that decreases as the kick velocity or acceleration increases. The black hole displacements may give rise to observable nonaxisymmetries in the morphology and dynamics of the stellar and gaseous disk of the galaxy. In some cases the dynamical center of the galaxy is seen to be displaced toward the direction of the BH acceleration with a characteristic tongue-shaped extension of the velocity contours on the side of the galaxy opposite the acceleration.
TEXES: A Sensitive High-Resolution Grating Spectrograph for the Mid-Infrared

We discuss the design and performance of TEXES, the Texas Echelon Cross Echelle Spectrograph. TEXES is a mid-infrared (5-25 μm) spectrograph with several operating modes: high resolution, cross-dispersed with a resolving power of R =λ/δλ ≈ 100,000, 0.5% spectral coverage, and a ~15 × 8'' slit; medium resolution, long-slit with R ≈ 15,000, 0.5% coverage, and a ~15 × 45'' slit; low-resolution, long-slit with δλ ≈ 0.004 μm, 0.25 μm coverage, and a ~ 15 × 45'' slit; and source acquisition imaging with 033 pixels and a 25'' × 25'' field of view on a 3 m telescope. TEXES has been used at the McDonald Observatory 2.7 m and the NASA Infrared Telescope Facility 3 m telescopes and has proved to be both sensitive and versatile.
A communication mechanism supporting actions

Abstract Many systems provide mechanisms for defining groups of logically related operations. For example, atomic transactions are the basic grouping concept in database systems and office activities in office information systems. In this paper, we will represent a mechanism for interprocess communication, which supports grouping of operations and forms a suitable base for developing a wide range of distributed systems. Operations can be grouped into so-called actions, where an action may represent an arbitrary (atomic or non-atomic) unit of work. Since actions are known at this level, rather complex mapping functions can be realized as part of the communication mechanism. It will be shown that providing those functions by the communication mechanism instead of implementing them in the application can improve system efficiency, simplicity, and modularity. Besides introducing the underlying system model, our communication mechanism is described in detail, and several examples demonstrating its use are given. Furthermore, the presented mechanism is compared with other communication schemes described in the literature.
Framework for power network analysis

Abstract The proposed framework for the analysis of electric power networks is motivated by the emerging concepts of power system security. Quantitative measures of system security can be derived within this framework on the basis of regions of operation in the space of system variables and parameters. Probabilistic aspects of load fluctuations and random faults in the network are included in the derivation of the probability number characterizing the level of security of each operating point. Additional research will be required for the practical application of this framework in planning and operating power systems.
Detection of coronal mass ejections in V471 Tauri with the Hubble Space Telescope

V471 Tauri, an eclipsing system consisting of a hot DA white dwarf (WD) and a dK2 companion in a 12.5 hr orbit, is the prototype of the precataclysmic binaries. The late-type component is magnetically active, due to its being constrained to rotate synchronously with the short orbital period. During a program of ultraviolet spectroscopy of V471 Tau, carried out with the Goddard High Resolution Spectrograph (GHRS) on board the Hubble Space Telescope, we serendipitously detected two episodes in which transient absorptions in the Si III 1206 A resonance line appeared suddenly, on a timescale of 2 minutes. The observations were taken in a narrow spectral region around Lyα and were all obtained near the two quadratures of the binary orbit, i.e., at maximum projected separation (~3.3 R☉) of the WD and K star. We suggest that these transient features arise when coronal mass ejections (CMEs) from the K2 dwarf pass across the line of sight to the WD. Estimates of the velocities, densities, and masses of the events in V471 Tau are generally consistent with the properties of solar CMEs. Given our detection of two events during 6.8 hr of GHRS observing, along with a consideration of the restricted range of latitudes and longitudes on the K star's surface that can give rise to trajectories passing in front of the WD as seen from Earth, we estimate that the active V471 Tau dK star emits some 100-500 CMEs day-1, as compared to ~1-3 day-1 for the Sun. The K dwarf's mass-loss rate associated with CMEs is at least (5-25) × 10-14 M☉ yr-1, but it may well be orders of magnitude higher if most of the silicon is in ionization states other than Si III.
Specially tailored transfinite-element formulations for hyperbolic heat conduction involving non-Fourier effects

The phenomenon of hyperbolic heat conduction in contrast to the classical (parabolic) form of Fourier heat conduction involves thermal energy transport that propagates only at finite speeds, as opposed to an infinite speed of thermal energy transport. To accommodate the finite speed of thermal wave propagation, a more precise form of heat flux law is involved, thereby modifying the heat flux originally postulated in the classical theory of heat conduction. As a consequence, for hyperbolic heat conduction problems, the thermal energy propagates with very sharp discontinuities at the wave front. Accurate solutions are found for a class of one-dimensional hyperbolic heat conduction problems involving non-Fourier effects that can be used effectively for representative benchmark tests and for validating alternate schemes. Modeling/analysis formulations via specially tailored hybrid computations are provided for accurately modeling the sharp discontinuities of the propagating thermal wave front. Comparative numerical test models are presented for various hyperbolic heat conduction models involving non-Fourier effects to demonstrate the present formulations.
Harnack estimate for the Endangered Species Equation

We prove a differential Harnack inequality for the Endangered Species Equation, a nonlinear parabolic equation. Our derivation relies on an idea related to the parabolic maximum principle. As an application of this inequality, we will show that positive solutions to this equation must blowup in finite time. We also use this inequality to partially answer a question of Hamilton, 2011.
Exogenous gonadotropin stimulation is associated with increases in serum androgen levels in in-vitro fertilization-embryo transfer cycles☆☆☆

Abstract Objective: To examine serum androgen profiles in women undergoing ovarian stimulation with exogenous gonadotropins in the setting of IVF-ET. Design: Prospective study. Setting: University hospital IVF-ET program. Patient(s): Seventeen ovulatory women undergoing IVF-ET for endometriosis, male factor infertility, or tubal disease. Intervention(s): A standard long protocol of GnRH agonist (GnRH-a) pretreatment (1 mg of leuprolide acetate SC for 10 days) was administered before ovulation induction with a urinary gonadotropin preparation. Main Outcome Measure(s): After 10 days of GnRH-a treatment and on the day of hCG administration, serum concentrations of LH, T, androstenedione (A), sex hormone-binding globulin (SHBG), and DHEAS; the free androgen index (T/SHBG); and the number of follicles, oocytes, and embryos were assessed. Result(s): Serum samples after 10 days of GnRH-a treatment showed incomplete LH suppression. While continuing the agonist during ovarian stimulation, LH values were suppressed further. However, serum T and A concentrations and the free androgen index showed a significant increase (samples drawn just before hCG administration). Serum T levels after 10 days of GnRH-a (before the administration of exogenous gonadotropins) were correlated negatively with the subsequent number of embryos. Conclusion(s): Serum LH suppression with a conventional regimen of GnRH-a is incomplete in this heterogeneous group of ovulatory women. Exogenous gonadotropin stimulation results in a marked increase in ovarian androgen secretion.
Family-Level Predictors and Correlates of the Duration of Untreated Psychosis in African American First-Episode Patients

Background Little is known about how family-level factors are associated with duration of untreated psychosis (DUP), especially in ethnic/racial minority groups, such as African Americans. This study involved African American first-episode patients and their family members who initiated evaluation and treatment for them. It was hypothesized that a longer DUP would be predicted by family members' endorsement of: (1) less knowledge about schizophrenia, (2) greater perceptions of stigma, (3) lower levels of insight, (4) fewer family strengths, (5) more limited family coping capacity, and (6) lower levels of caregiver strain.
Hybrid theory and calculation of e-N2 scattering

A theory of electron-molecule scattering was developed which was a synthesis of close coupling and adiabatic-nuclei theories. The theory is shown to be a close coupling theory with respect to vibrational degrees of freedom but is a adiabatic-nuclei theory with respect to rotation. It can be applied to any number of partial waves required, and the remaining ones can be calculated purely in one or the other approximation. A theoretical criterion based on fixed-nuclei calculations and not on experiment can be given as to which partial waves and energy domains require the various approximations. The theory allows all cross sections (i.e., pure rotational, vibrational, simultaneous vibration-rotation, differential and total) to be calculated. Explicit formulae for all the cross sections are presented.
Overview of the Beta II Two-Stage-To-Orbit vehicle design

A study of a near-term, low risk two-stage-to-orbit (TSTO) vehicle was undertaken. The goal of the study was to assess a fully reusable TSTO vehicle with horizontal takeoff and landing capability that could deliver 10,000 pounds to a 120 nm polar orbit. The configuration analysis was based on the Beta vehicle design. A cooperative study was performed to redesign and refine the Beta concept to meet the mission requirements. The vehicle resulting from this study was named Beta II. It has an all-airbreathing first stage and a staging Mach number of 6.5. The second stage is a conventional wing-body configuration with a single SSME.
Conditional accounting conservatism and future negative surprises: An empirical investigation

Abstract We investigate whether conditional accounting conservatism has informational benefits to shareholders. We find some evidence that higher current conditional conservatism is associated with lower probability of future bad news, proxied by missing analyst forecasts, earnings decreases, and dividend decreases. Second, we find weak evidence that the stock market reacts stronger (weaker) to good (bad) earnings news of more conditionally conservative firms. Thus, we provide additional evidence that conditional conservatism affects stock prices.
Cyclizations of ω-allenyl organometallic reagents

Abstract Allenyl organometallic reagents of type R2C C CH(CH2)nCH2M undergo cyclization at the central allenic carbon for n = 2 (M = Li) and at the near allenic carbon for n = 3 (M = CuCNLi) to provide cyclopentane systems; little cyclization, was observed for the n = 4 systems (M = Li, CuCNLi).
Molecular Systems Biology and Control

This paper, prepared for a tutorial at the 2005 IEEE Conference on Decision and Control, presents an introduction to molecular systems biology and some associated problems in control theory. It provides an introduction to basic biological concepts, describes several questions in dynamics and control that arise in the field, and argues that new theoretical problems arise naturally in this context. A final section focuses on the combined use of graph-theoretic, qualitative knowledge about monotone building-blocks and steadystate step responses for components.
Ribosomal Peptide Natural Products: Bridging the Ribosomal and Nonribosomal Worlds

Covering: up to July 2008 Ribosomally synthesized bacterial natural products rival the nonribosomal peptides in their structural and functional diversity. The last decade has seen substantial progress in the identification and characterization of biosynthetic pathways leading to ribosomal peptide natural products with new and unusual structural motifs. In some of these cases, the motifs are similar to those found in nonribosomal peptides, and many are constructed by convergent or even paralogous enzymes. Here, we summarize the major structural and biosynthetic categories of ribosomally synthesized bacterial natural products and, where applicable, compare them to their homologs from nonribosomal biosynthesis.
∗-Trek: the one-loop N=4 noncommutative SYM action

Abstract We investigate N =4 noncommutative super-Yang–Mills (SYM) theory. We compute the one-loop four gauge boson scattering amplitude on parallel Dp-branes, and find the corresponding contribution to the noncommutative SYM one-loop action in a momentum expansion. The result is somewhat surprising. We find that while the planar diagram can be written using the usual ∗ -product, the contributions from nonplanar diagrams in general involve additional structure beyond the ∗ -product, arising from the nontrivial worldsheet correlations surviving the field theory limit. To each nonplanar diagram, depending on the number n of external vertex operator insertions on each boundary, there is a corresponding ∗ n n-ary operation. We further find that it is no longer possible to write down an off-shell gauge invariant one-loop effective action using the noncommutative field strength defined at tree-level.
Artificial Immune System – Based Aircraft Failure Evaluation over Extended Flight Envelope

This paper describes the design, development, and flight-simulation testing of an artificial-immune-system-based approach for the evaluation of different aircraft subsystem failures/damages. The evaluation consists of the estimation of the magnitude/severity of the failure and the prediction of the achievable states, leading to an overall assessment of the effects of the failure on reducing the flight envelope. A supersonic fighter model is used, which includes model-following adaptive control laws based on nonlinear dynamic inversion and artificial neural network augmentation. Data collected from a motion-based flight simulator were used to define the self for a wide area of the flight envelope and to test and validate the proposed approach. Example results are presented for failure-magnitude evaluation and flight-envelope-reduction prediction for abnormal conditions affecting sensors, actuators, engine, and wing structure. Successful failure detection and identification are assumed before evaluation. The results show the capabilities of the artificial-immune-system-based scheme to evaluate the severity of the failure and to predict the reduction of the flight envelope in a general manner.
United States emergency department visits for vaginal bleeding during early pregnancy, 1993-2003

Objective The purpose of this study was to describe the epidemiology of emergency department (ED) visits for vaginal bleeding during early pregnancy (VBEP). Study Design We analyzed data from the National Hospital Ambulatory Medical Care Survey, 1993-2003. Cases presented with a complaint of vaginal bleeding and had diagnoses consistent with presentation during early pregnancy. Results Over the 11-year period, there were 5.4 million visits for VBEP, which represents 1.6% of all ED visits or almost 500,000 visits/year. ED visits for VBEP increased from 5.6-7.8 visits per 1000 US population ( P for trend Conclusion ED visits for VBEP are rising, particularly among younger and Hispanic women. Programs that ensure primary obstetric care would help decrease reliance on the ED for this important condition.
Regioselective benzoylation of sugars mediated by excessive Bu2SnO: observation of temperature promoted migration

Abstract Regioselective benzoylation of carbohydrates using an excess of dibutyltin oxide (Bu 2 SnO) at increased reaction temperatures has been developed for the synthesis of several glycoside benzoates with one or two free hydroxyl groups, including galactosides, glucosides, mannosides and lactosides in high yields. These compounds are useful as building blocks for the synthesis of complex saccharides and derivatives.
Stormy Weather and Cluster Radio Galaxies

Abstract New adaptive mesh refinement N-body+hydrodynamics numerical simulations are used to illustrate the complex and changing cluster environments in which many radio galaxies live and evolve. Groups and clusters of galaxies form at the intersections of filaments where they continue to accrete gas and dark matter to the present day. The accretion process produces shocks, turbulence, and transonic bulk flows forming a kind of stormy weather within the intracluster medium (ICM). Radio sources embedded within the stormy ICM form distorted, complex morphologies as observed in recent VLA cluster surveys. We show that the bending of wide-angle tailed radio sources can be understood as the result of recent cluster–subcluster mergers. We use new MHD simulations to illustrate how cluster radio halos can be formed by the shocks and turbulence produced during cluster mergers. Finally, we discuss new observations of distant Abell clusters that reveal a class of weak radio sources, probably starbursts, likely produced during the formation of the clusters as they accrete material from the supercluster environment.
Black hole evaporation in 1+1 dimensions

Abstract The formation and quantum mechanical evaporation of black holes in two spacetime dimensions can be studied using effective classical field equations, recently introduced by Callan et al. We find that gravitational collapse always leads to a curvature singularity, according to these equations, and that the region where the quantum corrections introduced by Callan et al. could be expected to dominate is on the unphysical side of the singularity. The model can be successfully applied to study the back-reaction of Hawking radiation on the geometry of large mass black holes, but the description breaks down before the evaporation is complete.
Disjoining Pressure Effects in Ultra-Thin Liquid Films in Micropassages—Comparison of Thermodynamic Theory With Predictions of Molecular Dynamics Simulations

The concept of disjoining pressure, developed from thermodynamic and hydrodynamic analysis, has been widely used as a means of modeling the liquid-solid molecular force interactions in an ultra-thin liquid film on a solid surface. In particular, this approach has been extensively used in models of thin film transport in passages in micro evaporators and micro heat pipes. In this investigation, hybrid μPT molecular dynamics (MD) simulations were used to predict the pressure field and film thermophysics for an argon film on a metal surface. The results of the simulations are compared with predictions of the classic thermodynamic disjoining pressure model and the Born-Green-Yvon (BGY) equation. The thermodynamic model provides only a prediction of the relation between vapor pressure and film thickness for a specified temperature. The MD simulations provide a detailed prediction of the density and pressure variation in the liquid film, as well as a prediction of the variation of the equilibrium vapor pressure variation with temperature and film thickness. Comparisons indicate that the predicted variations of vapor pressure with thickness for the three models are in close agreement. In addition, the density profile layering predicted by the MD simulations is in qualitative agreement with BGY results, however the exact density profile is dependent upon simulation parameters. Furthermore, the disjoining pressure effect predicted by MD simulations is strongly influenced by the allowable propagation time of injected molecules through the vapor region in the simulation domain. A modified thermodynamic model is developed that suggests that presence of a wall-affected layer tends to enhance the reduction of the equilibrium vapor pressure. However, the MD simulation results imply that presence of a wall layer has little effect on the vapor pressure. Implications of the MD simulation predictions for thin film transport in micro evaporators and heat pipes are also discussed.
Dynamics of component separation in a binary mixture of Bose-Einstein condensates

We describe the first experiments that study in a controlled way the dynamics of distinguishable and interpenetrating bosonic quantum fluids. We work with a two-component system of Bose-Einstein condensates in the $|{F\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1,m}_{f}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}1〉$ and $|2,1〉$ spin states of ${}^{87}\mathrm{Rb}$. The two condensates are created with complete spatial overlap, and in subsequent evolution they undergo complex relative motions that tend to preserve the total density profile. The motions quickly damp out, leaving the condensates in a steady state with a non-negligible (and adjustable) overlap region.
SERT II Hollow Cathode Multiple Restarts in Space

Future missions, both station keeping and primary electric propulsion, will require multiple thruster restarts after periods of inactivity from a few hours to over one year. Although not a part of the original SERT II (Space Electric Rocket Test) flight objective, the opportunity to demonstrate multiple cathode restarts in space became available following completion of thruster running. Both neutralizer and main cathodes of each flight thruster have been restarted repeatedly following storage periods up to 490 days. No deterioration of cathode heaters has been noted nor has any change been required in starting voltages or currents.
Small volume link orbifolds

This paper proves lower bounds on the volume of a hyperbolic 3-orbifold whose singular locus is a link. We identify the unique smallest volume orbifold whose singular locus is a knot or link in the 3-sphere, or more generally in a Z6 homology sphere. We also prove more general lower bounds under mild homological hypotheses.
PHOTOMETRIC ABUNDANCES FOR G DWARFS: A CAUTIONARY TALE

Analysis of cluster and field star uvby data demonstrates the existence of a previously undetected discrepancy in a widely used photometric metallicity calibration for G dwarfs. The discrepancy is systematic and strongly color dependent, reducing the estimated [Fe/H] for stars above [Fe/H] ~ -0.2 by between +0.1 and +0.4 dex and creating a deficit of metal-rich stars among dwarfs of mid G and later spectral type. The source of the problem, triggered for stars with b-y greater than about 0.47, appears to be an enhanced metallicity dependence for the c1 index that increases as temperature declines. The link between c1, normally a surface gravity indicator, and metallicity produces two secondary effects. The deficit in the photometric abundance for a cool dwarf is partially compensated by some degree of evolution off the main sequence, and cool dwarfs with metallicities significantly above the Hyades are found to have c1 indices that classify them as giants. The potential impact of the problem on stellar population studies is discussed.
Rapid synthesis of Sn-Beta for the isomerization of cellulosic sugars

Sn-Beta, a tin-containing molecular sieve with the zeolite beta topology, was rapidly synthesized in two days through a modified seeding method, and its high catalytic activity for the isomerization of cellulosic sugars was demonstrated.
Effects of Cycle Operating Conditions on Combustor Performance

To mitigate the environmental impact of next-generation gas turbine combustors, the emission performance at each condition throughout the load duty cycle must be optimized. Achieving this with a single combustor geometry may not be possible. Rather, the mixing processes and air flow splits must likely be modified as a function of load in order to (1) abate the emission of oxides of nitrogen, (2) maintain combustion efficiency, and (3) preclude lean blow-out over the entire duty cycle. The present study employs a model combustor to evaluate combustor performance as a function of load and explore the application of variable geometry to optimize performance at each condition. A parametric variation of flow splits is conducted at each load condition by independently adjusting the primary jet area and swirler choke area. The resultant impact on combustor performance is measured and quantified in in terms of a cost function. The cost function is defined to increase with improving combustor performance (e.g., improving combustion efficiency and/or declining NO x emissions). Cycle operating conditions are found to alter the response mappings of efficiency and NO x . As a result, the optimal configuration of the combustor changes as the load is varied over the duty cycle. The results provide guidance on the application of active control.
Channeling analysis of strain in superlattices

Abstract We review recent ion channeling methods for the analysis of the strain in epitaxially grown structures known as strained-layer superlattices (SLSs). These strain measurements have primarily utilized inclined-direction axial dechanneling or angular scans. More recently, a new channeling phenomenon, which involves a resonance between the planar channeling trajectory wavelength and the superlattice period, has been discovered in superlattices. Resonant conditions leading to both catastrophic dechanneling and resonant channeling are demonstrated for inclined planar directions in SLSs. Catastrophic dechanneling is shown to be the most sensitive of the channeling techniques for strain analysis. Comparison with detailed theoretical calculations shows that a simple modified-harmonic model can be used to extract the strain with relatively good accuracy from angular measurements of the catastrophic dechanneling.
Bounds on microscopic physics from P and T violation in atoms and molecules

Abstract Atomic and molecular electric dipole moments are calculated within the minimal supersymmetric standard model. Present experiments already provide strong bounds on the combination of phases responsible for the dipole moments of the neutron and closed shell atoms. For a supersymmetry breaking scale of 100 GeV, these phases must be smaller than ∼10 −2 .
Recent advances in high oxidation state Mo and W imido alkylidene chemistry.

In 1956 Eleuterio invoked what is now known as an olefin metathesis reaction in order to explain how certain heterogeneous Mo catalysts could produce polyethylene from propylene; he proposed that propylene was converted into 2-butene and ethylene and that ethylene was then selectively polymerized.i An intense interest in the catalytic olefin metathesis reaction developed in the 1970's as a consequence of the ability to synthesize various polymers from cyclic olefins using tungsten, molybdenum, and rhenium catalysts (prepared using a variety of recipes) and as people became aware of potential applications of olefin metathesis in organic chemistry. The accepted mechanism of the olefin metathesis reaction, the basic version of which is shown in equation 1, was proposed in 1971 by Herrison and Chauvin (equation 2),ii but no 2RCH=CHR′⇄RCH=CHR+R′CH=CHR′.(cis and trans equilibrated also) (1) (2) M=CHR complexes were known at that time that would react with olefins catalytically in a metathesis-like fashion. Therefore a search began for M=C complexes that would carry out the metathesis reaction rapidly and catalytically, could be isolated and studied, could be varied in great detail, and could tolerate various functional groups of interest in catalytic organic transformations.
Stochastic combined heat and power dispatch based on multi-objective particle swarm optimization

Conventional economic power dispatch problem uses deterministic models, which are however not able to reflect some real situations in practical applications. Since certain inaccurate and uncertain factors are normally involved in system operations, stochastic models are more suited for investigating some of the power dispatch problems. In this paper, the stochastic model for combined heat and power (CHP) dispatch is first formulated, and then an improved particle swarm optimization (PSO) method is developed to deal with the economic CHP dispatch by simultaneously considering multiple conflicting objectives. Based on the proposed optimization method, the impact of different problem formulations including stochastic and deterministic models on power dispatch results is investigated and analyzed. Furthermore, a comparative study is carried out with respect to genetic algorithm (GA) in terms of solution quality and computational expense.
Iron-Catalyzed Intermolecular Hydroamination of Styrenes

An iron-catalyzed formal hydroamination of alkenes has been developed. It features O-benzoyl-N,N-dialkylhydroxylamines as the electrophilic nitrogen source and cyclopentylmagnesium bromide as the reducing agent for intermolecular hydroamination of styrene and derivatives with good yield and excellent Markovnikov regioselectivity. The reaction presumably proceeds through the iron-catalyzed hydrometalation of styrene followed by electrophilic amination with the electrophilic O-benzoylhydroxylamine.
Synthesis of o-indan[1.1.1]cyclophane and potential indanyl subunits of the fullerenes

Treatment of indane-5-carbinol with aqueous acid gave among other products the cyclic trimer cyclo[3]CH2-[3]indane 7, which was also formed fro
Mild, selective deprotection of PMB ethers with triflic acid/1,3-dimethoxybenzene

An efficient method for the cleavage of the p-methoxybenzyl protecting group of several alcohols in the presence of 0.5 equiv of trifluoromethanesulfonic acid and 1,3-dimethoxybenzene in dichloromethane at room temperature is described.
Tumor suppressor genes

For the past two decades, oncogenes have captured the lion’s share of attention among those interested in the molecular and genetic bases of cell transformation. These genes have presented a powerful paradigm of how cell transformation takes place when triggered by viral infections or somatic mutation. Yet we now realize that there is an equally important second side of the coin, presented by a distinct class of genes known variously as tumor suppressor genes or anti-oncogenes. The existence of tumor suppressor genes could have been predicted from first principles, but few had the temerity to do so. The logic of their function is simple and straightforward. Cellular oncogenes represent deregulated, hyperactive forms of normal cellular growth-promoting genes (proto-oncogenes). The activation of an oncogene in the genome of a normal cell results in the release of a steady stream of mitogenie signals that forces a cell and its descendants through unrelenting rounds of division. Logic dictates an equally elaborate array of growthconstraining elements in the cell’s signaling circuitry that serve as a counterweight to the growth-promoting proto-oncogenes. Their loss through mutational inactivation might lead to runaway cell growth. We now know that tumor cell growth often depends on the confluence of both types of genetic change, yielding hyperactivegrowth-promotinggenes(oncogenes) on the one hand and inactive versions of the growthconstraining genes (tumor suppressors) on the other. The very existence of such suppressor genes becomes apparent only when they are lost from the cell genome. This experimental difficulty has kept progress in the field studying these genes a decade behind that devoted to research on oncogenes. But this substantial inconvenience has been swept aside by new and powerful means of detecting tumor suppressor genes and isolating them through molecular cloning. We now have a collection of more than a half dozen of these genes in cloned form. Inactivated versions of each can be found in the genomes of a variety of tumor cell types (see Table 1).
A pair of non-homeomorphic product measures on the Cantor set

For r ∈ [0, 1] let μ r be the Bernoulli measure on the Cantor set given as the infinite power of the measure on {0, 1} with weights r and 1 − r . For r , s ∈ [0, 1] it is known that the measure μ r is continuously reducible to μ s (that is, there is a continuous map sending μ r to μ s ) if and only if s can be written as a certain kind of polynomial in r ; in this case s is said to be binomially reducible to r . In this paper we answer in the negative the following question posed by Mauldin: Is it true that the product measures μ r and μ s are homeomorphic if and only if each is a continuous image of the other , or , equivalently , each of the numbers r and s is binomially reducible to the other ?
Internal Promotion Competitions in Firms

Using a sample of skilled workers from a cross section of establishments in four metropolitan areas of the United States, I present evidence suggesting that promotions are determined by relative worker performance. I then estimate a structural model of promotion tournaments (treating as endogenous promotions, worker performance, and the wage spread from promotion) that simultaneously accounts for worker and firm behavior and how the interaction of these behaviors gives rise to promotions. The results are consistent with the predictions of tournament theory that employers set wage spreads to induce optimal performance levels, and that workers are motivated by larger spreads.
On the power of parity polynomial time

This paper proves that the complexity class ⊕P, parity polynomial time [PZ], contains the class of languages accepted byNP machines with few accepting paths. Indeed, ⊕P contains a broad class of languages accepted by path-restricted nondeterministic machines. In particular, ⊕P contains the polynomial accepting path versions ofNP, of the counting hierarchy, and of Mod m NP form>1. We further prove that the class of nondeterministic path-restricted languages is closed under bounded truth-table reductions.
A new catalytic enantioselective reducing reagent system from (−)-α,α-diphenylpyrrolidinemethanol and 9-borabicyclo[3.3.1]nonane, especially effective for hindered and substituted aralkylketones

Abstract New catalytic enantioselective reduction systems were prepared from aminoalcohols and dialkylboranes, for the enantioselective reductions of prochiral aromatic ketones. Among these, the system prepared from (−)-α,α-diphenylpyrrolidinemethanol with 9-borabicyclo[3.3.1]nonane proved especially promising for such reductions. This complex catalyzes the reduction of prochiral aralkyl ketones to the corresponding alcohols with BH 3 –THF, with enantioselectivities 82–99.2%. Also, this catalyst is particularly effective for the more hindered and substituted aralkyl ketones. Various modifications in this new catalytic reduction system, such as changing reaction conditions, reducing agent and dialkylborane, were also examined.
A Note on the Minimax Solution for the Two-Stage Group Testing Problem.

Group testing is an active area of current research and has important applications in medicine, biotechnology, genetics, and product testing. There have been recent advances in design and estimation, but the simple Dorfman procedure introduced by R. Dorfman in 1943 is widely used in practice. In many practical situations, the exact value of the probability p of being affected is unknown. We present both minimax and Bayesian solutions for the group size problem when p is unknown. For unbounded p, we show that the minimax solution for group size is 8, while using a Bayesian strategy with Jeffreys’ prior results in a group size of 13. We also present solutions when p is bounded from above. For the practitioner, we propose strong justification for using a group size of between 8 and 13 when a constraint on p is not incorporated and provide useable code for computing the minimax group size under a constrained p.