cssi/SciSciGPT-SciSciNet huggingface dataset:
The Evolution of Outflow-Envelope Interactions in Low-Mass Protostars

We present multiline and continuum observations of the circumstellar environment within 10to the 4th AU of a sample of protostars to investigate how the effects of outflows on their immediate environment change over time. 12CO (1–0) emission probes the high-velocity molecular outflows near the protostars and demonstrates that the outflow opening angle widens as the nascent star evolves. Maps of the 13CO (1–0) and HCO+ (1–0) outflow emission show that protostellar winds erode the circumstellar envelope through the entrainment of the outer envelope gas. The spatial and velocity distribution of the dense circumstellar envelope, as well as its mass, is traced by the C to the 18th O (1–0) emission and also displays evolutionary changes. We show that outflows are largely responsible for these changes and propose an empirical model for the evolution of outflow-envelope interactions. In addition, some of the outflows in our sample appear to affect the chemical composition of the surrounding environment, enhancing the HCO+ abundance. Overall, our results confirm that outflows play a major role in the star formation process through their strong physical and chemical impacts on the environments of the young protostars.
A subspace method for signature waveform estimation in synchronous CDMA systems

Synchronous code-division multiple-access (CDMA) techniques possess intrinsic protection against co-channel interference due to orthogonal codes employed and thus, offers higher capacity than existing frequency-division multiple-access (FDMA) or time-division multiple-access (TDMA) systems. In the presence of multipath, however, each signal is subject to frequency-selective fading and the orthogonality condition does not necessarily hold leading to increased cross correlation. In these scenarios, multiuser detection need to be performed to suppress interference and recover the message symbols. To implement such a technique, explicit knowledge of the (nonorthogonal) signature waveforms of all users is required. We propose a blind estimation scheme that provides closed-form estimates of the signature waveforms by exploiting the structure information of the data output. In particular, we show that the subspace of the data matrix contains sufficient information for unique determination of the signature waveforms. Based on this observation, a multiple signal classification (MUSIC)-like algorithm is derived. Performance analysis of the new approach is also presented.
Four-dimensional string-string-string triality

Abstract In six space-time dimensions, the heterotic string is dual to a Type IIA string. On further toroidal compactification to four space-time dimensions, the heterotic string acquires an SL(2, Z)s strong/weak coupling duality and an SL(2, Z)t × SL(2, Z)u target space duality acting on the dilaton/axion, complex Kahler form and the complex structure fields S, T, U respectively. Strong/weak duality in D = 6 interchanges the roles of S and T in D = 4 yielding a Type IIA string with fields T, S, U. This suggests the existence of a third string (whose six-dimensional interpretation is more obscure) that interchanges the roles of S and U. It corresponds in fact to a Type IIB string with fields U, T, S leading to a four-dimensional string/string/string triality. Since SL(2, Z)s is perturbative for the Type IIB string, this D = 4 triality implies S-duality for the heterotic string and thus fills a gap left by D = 6 duality. For all three strings the total symmetry is SL(2, Z)s × 0(6,22; Z)tu. The 0(6,22; Z) is perturbativefor the heterotic string but contains the conjectured non perturbative SL(2, Z)x, where X is the complex scalar of the D = 10 Type IIB string. Thus four-dimensional triality also provides a (post-compactification) justification for this conjecture. We interpret the N = 4 Bogomol'nyi spectrum from all three points of view. In particular we generalize the Sen-Schwarz formula for short multiplets to include intermediate multiplets also and discuss the corresponding black hole spectrum both for the N = 4 theory and for a truncated S-T-U symmetric N = 2 theory. Just as the first two strings are described by the four-dimensional elementary and dual solitonic solutions, so the third string is described by the stringy cosmic string solution. In three dimensions all three strings are related by 0(8,24; Z) transformations.
A freely available wide coverage morphological analyzer for English

This paper presents a morphological lexicon for English that handle more than 317000 inflected forms derived from over 90000 stems. The lexicon is available in two formats. The first can be used by an implementation of a two-level processor for morphological analysis (Karttunen and Wittenburg, 1983; Antworth, 1990). The second, derived from the first one for efficiency reasons, consists of a disk-based database using a UNIX hash table facility (Seltzer and Yigit, 1991). We also built an X Window tool to facilitate the maintenance and browsing of the lexicon. The package is ready to be integrated into an natural language application such as a parser through hooks written in Lisp and C.To our knowledge, this package is the only available free English morphological analyzer with very wide coverage.
Support vector machines in analysis of top quark production

Abstract The Support Vector Machine (SVM) learning algorithm is a new alternative to multivariate methods such as neural networks. Potential applications of SVMs in high energy physics include the common classification problem of signal/background discrimination as well as particle identification. A comparison of a conventional method and an SVM algorithm is presented here for the case of identifying top quark events in Run II physics at the CDF experiment.
Preparation and Transport Properties of New Oxide Ion Conductors KNb1-xMgxO3-δ by High Temperature and Pressure

A series of oxide ion conductors KNb_(1-x)Mg_xO_(3-δ) (x = 0.05−0.30) were prepared at a temperature of 870 °C and a pressure of 4.0 GPa. All samples were thermodynamically stable at ambient pressure and crystallized in an orthorhombic perovskite structure. The lattice volume enlarged with increment of dopant level, which was associated with the ionic substitution, variation of the relative content of oxygen vacancy Vo, and defect associations {Mg_(Nb)‘ ‘‘Vo}, as well as an increase of disorder in Mg^(2+)/Nb^(5+) distribution at B-sites of perovskite lattice. At higher temperatures, KNb_(1-x)Mg_xO_(3-δ) underwent phase transitions from orthorhombic to tetragonal, pseudocubic, and cubic in sequence, as confirmed by DTA and high-temperature Raman spectra. No thermal effects associated with the decomposition reactions were observed in KNb_(1-x)Mg_xO_(3-δ) during the successive heating process up to 1000 °C. The high-temperature phase had a relatively high structural stability. Impedance spectra of KNb_(1-x)Mg_xO_(3-δ) showed bulk and grain boundary conduction. The total conduction was determined to be predominately ionic, while the p-type electronic contribution was extremely small. KNb_(0.90)Mg_(0.10)O_(2.85) was found to provide a highly conductive phase with a conductivity of σ_(700°C) = 1.10 × 10^(-3) S·cm^(-1). Further, the ionic conductivity data for KNb_(1-x)Mg_xO_(3-δ) were separated into two linear ranges, corresponding to the pseudocubic and cubic phases, respectively. The variations of conductivity and activation energy for both pseudocubic and cubic phases can be explained in terms of the relative content of the oxygen vacancy and defect associations, delocalization of partial oxygen vacancies, and an order−disorder transition.
A rapid-scanning autocorrelation scheme for continuous monitoring of picosecond laser pulses

We describe a scheme for rapidly introducing a periodic linear time delay to a train of picosecond laser pulses. By incorporating this scheme in one arm of the Michelson interferometer of a conventional autocorrelator, the second order intensity autocorrelation function of a cw train of picosecond pulses is continuously displayed on an oscilloscope.
Intermediate Alcohol-Gasoline Blends, Fuels for Enabling Increased Engine Efficiency and Powertrain Possibilities

The present study experimentally investigates spark-ignited combustion with 87 AKI E0 gasoline in its neat form and in mid-level alcohol-gasoline blends with 24% vol./vol. iso-butanol-gasoline (IB24) and 30% vol./vol. ethanol-gasoline (E30). A single-cylinder research engine is used with a low and high compression ratio of 9.2:1 and 11.85:1 respectively. The engine is equipped with hydraulically actuated valves, laboratory intake air, and is capable of external exhaust gas recirculation (EGR). All fuels are operated to full-load conditions with =1, using both 0% and 15% external cooled EGR. The results demonstrate that higher octane number bio-fuels better utilize higher compression ratios with high stoichiometric torque capability. Specifically, the unique properties of ethanol enabled a doubling of the stoichiometric torque capability with the 11.85:1 compression ratio using E30 as compared to 87 AKI, up to 20 bar IMEPg at =1 (with 15% EGR, 18.5 bar with 0% EGR). EGR was shown to provide thermodynamic advantages with all fuels. The results demonstrate that E30 may further the downsizing and downspeeding of engines by achieving increased low speed torque, even with high compression ratios. The results suggest that at mid-level alcohol-gasoline blends, engine and vehicle optimization can offset the reduced fuel energy content of alcohol-gasoline more » blends, and likely reduce vehicle fuel consumption and tailpipe CO2 emissions. « less
A systematic, multidisciplinary approach to address the reproductive needs of HIV- seropositive women

Nearly 130,000 American women are human immunodeficiency virus (HIV) seropositive. The present study sought to establish a comprehensive programme to address their fertility needs in order to minimize infectious, medical and reproductive risks to prospective patients. Forty women, aged 27-42 years, were evaluated. HIV was diagnosed 7.2 +/- 0.7 years prior to their seeking care, and most women (n = 38) were on highly active antiretroviral therapy. Their prenatal CD4 counts were 712.2 +/- 56 cells/mm(3) (range 327-1881) and HIV-1 concentrations were undetectable in all cases prior to initiating treatment. HIV-seropositive women were statistically identical to their age-matched HIV-seronegative counterparts with respect to the IVF clinical outcome parameters measured. Throughout the pregnancies, maternal HIV-1 RNA concentrations remained undetectable and CD4 counts were stable. All infants, tested at birth and at 3 and 6 months of age, remained HIV negative. This is the first report of an institutional paradigm in the USA dedicated to evaluate and treat HIV-seropositive women. Using a multidisciplinary approach to care, HIV-seropositive women may be successfully managed in a programme of assisted reproduction.
POLAR-OPTICAL PHONON ENHANCEMENT OF HARMONIC GENERATION IN SCHOTTKY DIODES

Polar-optical phonons have an important influence on polar semiconductor device behavior, in polar crystals at very high frequency, because they directly perturb the effective material permittivity in the vicinity of the transverse polar-optical vibration frequency. This phenomenon leads to dramatic nonlinear effects on the resistive and the reactive physics at the Schottky barrier interface. Hence this physical effect provides a mechanism with the potential for producing significant levels of power at higher harmonics. We have established a simulator that combines the modified harmonic-balance circuit analysis technique with a polar-optical phonon hydrodynamic transport model to determine the maximum power generation and/or power efficiency in the second harmonic. An abrupt junction model that includes the polar-optical phonon dynamics in a depletion layer was developed and utilized in this study. Simulation results have revealed a dramatic influence on the second harmonic power of the Schottky diode at the transverse polar-optical frequency and in the vicinity of one-half of the transverse polar-optical frequency. The transverse polar-optical frequency in GaAs is 7.78 THz and this is a rather high for practical applications. Bismuth trisulfide (Bi2S3) has been identified as a polar material that has the transverse polar-optical frequency on the order of 300 GHz, which is in a range more suited to THz-frequency multiplier applications. The dependence of the second harmonic power of the Schottky diode on the frequency demonstrates two enhanced peaks in the vicinity of the transverse polar-optical frequency. These preliminary results suggest that Bi2S3 Schottky diode based multipliers have potential as enhanced sources within the terahertz regime.
Catalytic Enantioselective Peroxidation of α,β-Unsaturated Ketones

Despite the potential of chiral peroxides as biologically interesting or even clinically important compounds, no catalytic enantioselective peroxidation has been reported. With a chiral catalyst not only to induce enantioselectivity but also to convert a well established epoxidation pathway into a peroxidation pathway, the first efficient catalytic peroxidation has been successfully developed. Employing readily available α,β-unsaturated ketones and hydroperoxides and an easily accessible cinchona alkaloid catalyst, this novel reaction will open new possibilities in the asymmetric synthesis of chiral peroxides. Under different conditions a highly enantioselective epoxidation with the same starting materials, reagents, and catalyst has was also established.
Delay of finite-span excrescence-induced transition using plasma-based control

Direct numerical simulations are carried out to explore the use of flow control that delays transition generated by excrescence on a plate-like geometry in subsonic flow. Both forward-facing and rearward-facing steps of small roughness heights are considered in the investigation. These are representative of joints and other surface imperfections on wing sections that disrupt laminar flow, thereby increasing skin friction and configuration drag. Unlike previous studies, the steps have a finite lateral extent, such that sharp edges occur in both the spanwise and streamwise directions, and provide a more realistic characterisation of misaligned panels in aerodynamic configurations. The effect of spanwise corners upon transition is examined, and dielectric barrier discharge plasma-based flow control is applied to delay transition and increase the extent of the laminar flow region. Solutions are obtained to the Navier– Stokes equations that were augmented by source terms used to represent body forces imparted by plasma actuators on the fluid. A simple phenomenological model provided these forces resulting from the electric field generated by the plasma. The numerical method is based upon a high-fidelity scheme and an implicit time-marching approach, on an overset mesh system that is used to represent the finite-span steps. Very small-amplitude numerical forcing is employed to generate perturbations, which are amplified by the geometric disturbances and result in transition, similar to the physical situation. Both continuous and pulsed operations of actuators are considered, and the effectiveness of the control is quantified. Transition with the forward-facing step is considerably exacerbated by the presence of a spanwise edge. Plasma control is minimally effective, even with the use of multiple actuators and increased applied force. For the rearward-facing step, transition is substantially delayed by plasma control with small force application.
An analysis of minimum heat trajectories for entry at hyperbolic speeds.

Optimum trajectory control for minimum heating paths during manned vehicle reentry at hyperbolic speeds
Synthesis of N-substituted pyrrolin-2-ones

Abstract During studies towards the synthesis of microcolin analogues, an unexpected dehydration was observed when 1-benzyloxycarbonyl-4-hydroxy-5-methylpyrrolidin-2-one was treated with di- tert -butyl dicarbonate in the presence of 4-dimethylaminopyridine. This reaction was used for the stereospecific synthesis of several N-protected pyrrolin-2-ones.
Effect of environmental temperature upon rates and duration of hemolysis of squaliform erythrocytes

Abstract 1. 1. Squaliform erythrocytes hemolyze in isosmotic solutions of urea. 2. 2. The rate of hemolysis is dependent both upon the acclimation temperature and upon the temperature at which hemolysis is performed. 3. 3. The observed differences in hemolytic rate are not due to differences in initial erythrocyte volumes. 4. 4. A reduction in acclimation temperature caused nurse shark erythrocytes to become more resistant to hemolysis.
Pre-play communication in two-person sealed-bid double auctions

Allowing unmediated communication in a two-person double auction dramatically enlarges the set of equilibrium outcomes. It then consists of all allocation rules that are equilibrium outcomes of games in which all traders have the power at the end to veto proposed trades. All the allocation rules so characterized are equilibrium outcomes of a single game in which the traders exchange messages once before bidding in a double auction. These outcomes are all obtained by equilibria in which the traders truthfully tell each other their values. Adding a mediator achieves no further outcomes.
Plasma doping for ultra-shallow junctions

Abstract Plasma doping (PD) processes utilizing PH3/He and B2H6/He plasmas to fabricate CMOS devices are presented. The applications of PD in ultra-shallow junctions are discussed. Low contamination levels and good device characteristics have been achieved. Based on its superior features such as low cost, high throughput, very low implant energy, low contamination, etc., this novel doping technique has been demonstrated as a good candidate for the next generation microelectronics.
HLA-DR-positive dendritic cells of the normal human choroid plexus: A potential reservoir of HIV in the central nervous system☆

In a previous study of choroid plexus (CPx) from patients with the acquired immunodeficiency syndrome (AIDS), we found a population of stromal cells infected with the human immunodeficiency virus (HIV). To determine whether these represented antigen-presenting dendritic cells, we examined the phenotype of normal human choroid plexus by light and electron microscopy (EM) and established the HIV-infected cell type by immunohistochemistry in AIDS cases with HIV-infected CPx. Monoclonal antibodies were used to detect class II major histocompatibility antigens (MHC), S-100 and S-100beta protein, lymphocytes, monocytes/macrophages, and HIV glycoprotein. A variable number of stromal cells had slightly elongated nuclei and long branching processes that were strongly immunoreactive for class II MHCs, rarely reactive for S-100 and S-100beta and immunonegative for monocyte/macrophage markers. Phagocytic activity was absent by EM and immunomarkers. They were numerous in the subepithelial region, and their processes occasionally extended toward the stromal capillaries or between the CPx epithelial cells. The HIV-infected cells were intensely immunoreactive for class II MHC markers and often displayed a dendritic morphology. These results document the presence of dendritic cells in the normal human CPx whose morphology and immunophenotype closely resemble those of DCs elsewhere in the body. They also show that these immunoreactive MHC class II cells are the cell type infected by HIV. We suggest that the functional activity of the CPx DCs is similar to that of antigen-presenting dendritic cells elsewhere in the body. This includes the potential to harbor HIV during the prolonged period of clinical latency, acting as a central nervous system reservoir of infection before the onset of AIDS.
Simpler Computation of Single-Source Shortest Paths in Linear Average Time

Meyer as well as Goldberg recently described algorithms that solve the single-source shortest-paths problem in linear average time on graphs with random edge lengths drawn from the uniform distribution on [0,1]. This note points out that the same result can be obtained through simple combinations of standard data structures and with a trivial probabilistic analysis.
PROTECT: proximity-based trust-advisor using encounters for mobile societies

Many interactions between network users rely on trust, which is becoming particularly important given the security breaches in the Internet today. These problems are further exacerbated by the dynamics in wireless mobile networks. In this paper we address the issue of trust advisory and establishment in mobile networks, with application to ad hoc networks, including DTNs. We utilize encounters in mobile societies in novel ways, noticing that mobility provides opportunities to build proximity, location and similarity based trust. Four new trust advisor filters are introduced - including encounter frequency, duration, behavior vectors and behavior matrices - and evaluated over an extensive set of real-world traces collected from a major university. Two sets of statistical analyses are performed; the first examines the underlying encounter relationships in mobile societies, and the second evaluates DTN routing in mobile peer-to-peer networks using trust and selfishness models. We find that for the analyzed trace, trust filters are stable in terms of growth with time (3 filters have close to 90% overlap of users over a period of 9 weeks) and the results produced by different filters are noticeably different. In our analysis for trust and selfishness model, our trust filters largely undo the effect of selfishness on the unreachability in a network. Thus improving the connectivity in a network with selfish nodes.We hope that our initial promising results open the door for further research on proximity-based trust.
Entropy production rates of bistochastic strictly contractive quantum channels on a matrix algebra

We derive, for a bistochastic strictly contractive quantum channel on a matrix algebra, a relation between the contraction rate and the rate of entropy production. We also sketch some applications of our result to the statistical physics of irreversible processes and to quantum information processing.
Catalytic, Regiospecific End‐Functionalization of Alkanes: Rhenium‐Catalyzed Borylation under Photochemical Conditions

Approaching a Holy Grail? A regioselective functionalization of alkanes occurs with commercially available rhenium catalysts and borane reagents under photochemical conditions [Eq. (1)]. Mechanistic studies indicate that the regioselectivity results from a direct thermal reaction of a photochemically generated 16–electron boryl complex with alkane.
SHARPENING THE TIP OF THE RED GIANT BRANCH

We introduce a modified detection method for measuring the luminosity of the tip of the red giant branch (TRGB) by introducing the composite magnitude T ≡ I – β[(V – I) – 1.50], where β is the slope of the tip magnitude as a function of color (or metallicity). The method is specifically designed to account for known systematics due to metallicity. In doing so, this simple transformation does away with arbitrary color selections in measuring the tip, and thereby significantly boosts the population of resolved stars that go into defining the TRGB distance. Moreover, this method coincidentally reduces the impact of reddening on the true modulus as well as its final uncertainty.
A preliminary comparison of Landsat Thematic Mapper and SPOT-1 HRV multispectral data for estimating coniferous forest volume

Digital Landsat Thematic Mapper (TM) and SPOT high-resolution visible (HRV) images of coniferous forest canopies were compared in their relationship to forest wood volume using correlation and regression analyses. Significant inverse relationships were found between softwood volume and the spectral bands from both sensors (P less than 0.01). The highest correlations were between the log of softwood volume and the near-infrared bands.
Effects of kinks on DNA elasticity

We study the elastic response of a wormlike polymer chain with reversible kinklike structural defects. This is a generic model for (a) the double-stranded DNA with sharp bends induced by binding of certain proteins, and (b) effects of trans-gauche rotations in the backbone of the single-stranded DNA. The problem is solved both analytically and numerically by generalizing the well-known analogy to the quantum rotator. In the small stretching force regime, we find that the persistence length is renormalized due to the presence of the kinks. In the opposite regime, the response to the strong stretching is determined solely by the bare persistence length with exponential corrections due to the "ideal gas of kinks." This high-force behavior changes significantly in the limit of high bending rigidity of the chain. In that case, the leading corrections to the mechanical response are likely to be due to the formation of multikink structures, such as kink pairs.
QUANTUM MATTERS: PHYSICS BEYOND LANDAU'S PARADIGMS

Central to our understanding of quantum many particle physics are two ideas due to Landau. The first is the notion of the electron as a well-defined quasiparticle excitation in the many body state. The second is that of the order parameter to distinguish different states of matter. Experiments in a number of correlated materials raise serious suspicions about the general validity of either notion. A growing body of theoretical work has confirmed these suspicions, and explored physics beyond Landau's paradigms. This article provides an overview of some of these theoretical developments.
Diffusion in Amorphous Polymers

Diffusion and solubility coefficients are presented for He, Ne, Ar, and N2 in three ethylene-propylene copolymers, two styrene-butadiene copolymerg and a cis-poly-butadiene for five temperature levels in the range 0–50°C. The data were obtained by using a slightly modified Dow Gas Transmission Cell and analyzed by a new modified time-lag technique which properly accounts for the increase in pressure on the downstream side of the cell. Activation energies were calculated for the twenty-four diffusion systems and correlated with the polymer intermolecular forces and the gas molecule sizes by using ii cell theory for amorphous polymers which employs a potential energy depth parameter, ϵ*, a range parameter, p*, the number of degrees of freedom per structural unit (center), 3Cm, and the number of centers per unit cell, n. The first three parameters were evaluated from thermodynamic data, while n was evaluated from the diffusion data. It is believed that n is an indication of the number of backbone carbon atoms active in polymer segmental motion. The values obtained here (5–9) agree well with existing values estimated from polymer viscous flow data. A correlation for the solubility data is shown and a linear free energy relationship is discussed.
Black holes and quantum coherence

We attempt to gain some insight into the issue of whether pure states evolve to density matrices in the black hole evaporation process by examining the mode functions of the particles entering the black hole which are correlated with the particles which escape to infinity. We show that these particles enter the black hole singularity at relatively early times. This tends to support the view that pure states evolve to density matrices, i.e., that in this process quantum coherence is lost.
Does observation of others affect learning in strategic environments? An experimental study

This paper presents experimental results from an analysis of two similar games, the repeated ultimatum game and the repeated best-shot game. The experiment examines whether the amount and content of information given to players aects the evolution of play in the two games. In one experimental treatment, subjects in both games observe not only their own actions and payos, but also those of one randomly chosen pair of players in the just-completed round of play. In the other treatment, subjects in both games observe only their own actions and payos. We present evidence sug- gesting that observation of other players' actions and payos may aect the evolution of play relative to the case of no observation.
Synchronization transformations for parallel computing

As parallel machines become part of the mainstream computing environment, compilers will need to apply synchronization optimizations to deliver efficient parallel software. This paper describes a new framework for synchronization optimizations and a new set of transformations for programs that implement critical sections using mutual exclusion locks. These transformations allow the compiler to move constructs that acquire and release locks both within and between procedures and to eliminate acquire and release constructs.The paper also presents a new synchronization algorithm, lock elimination, for reducing synchronization overhead. This optimization locates computations that repeatedly acquire and release the same lock, then uses the transformations to obtain equivalent computations that acquire and release the lock only once. Experimental results from a parallelizing compiler for object-based programs illustrate the practical utility of this optimization. For three benchmark programs the optimization dramatically reduces the number of times the computations acquire and release locks, which significantly reduces the amount of time processors spend acquiring and releasing locks. For one of the three benchmarks, the optimization always significantly improves the overall performance. Depending on the number of processors executing the computation, the optimized version runs between 2.11 and 1.83 times faster than the unoptimized version. For one of the other benchmarks, the optimized version runs between 1.13 and 0.96 times faster than the unoptimized version, with a mean of 1.08 times faster. For the final benchmark, the optimization reduces the overall performance.
Mild and selective reductions of aryl halides catalyzed by low-valent nickel complexes

Abstract Treatment of aryl chlorides with catalytic amounts of (PPh3)2NiCl2+PPh3 in the presence of an equivalent of Me2NH·BH3 and either K2CO3 or Cs2CO3 in CH3CN under mild conditions leads to the corresponding product of reduction. Aryl bromides and iodides can also be reduced, selectively, using this reagent combination.
Little miracles of supersymmetric evolution of gauge couplings

The invention of supersymmetry, almost exactly 25 years ago,1 changed the face of high energy physics. The idea that the observed low energy gauge groups appear due to the process of spontaneous breaking of a single unifying group G is also quite popular. The synthesis of these two elements results in supersymmetric grand unification. I present (perturbatively) exact results regarding the supersymmetric evolution of the gauge couplings from the scale of their unification to lower scales. In particular, it is shown how the heavy mass thresholds can be properly taken into account to all orders.
Tidal Spin-up of Stars in Dense Stellar Cusps around Massive Black Holes

We show that main-sequence stars in dense stellar cusps around massive black holes are likely to rotate at a significant fraction of the centrifugal breakup velocity as a result of spin-up by hyperbolic tidal encounters. We use realistic stellar structure models to calculate analytically the tidal spin-up in soft encounters and extend these results to close and penetrating collisions using smoothed particle hydrodynamics simulations. We find that the spin-up effect falls off only slowly with distance from the black hole because the increased tidal coupling in slower collisions at larger distances compensates for the decrease in the stellar density. We apply our results to the stars near the massive black hole in the Galactic center. Over their lifetime, ~1 M☉ main-sequence stars in the inner 0.3 pc of the Galactic center are spun-up on average to ~10%-30% of the centrifugal breakup limit. Such rotation is ~20-60 times higher than is usual for such stars and may affect their subsequent evolution and their observed properties.
Supersymmetry and strongly coupled gauge theories

Abstract I briefly review how supersymmetry helps in the extraction of exact nonperturbative information from field theories, and then discuss some open problems in strongly coupled gauge theories.
JONES POLYNOMIALS, VOLUME AND ESSENTIAL KNOT SURFACES: A SURVEY

This paper is a brief overview of recent results by the authors relating colored Jones polynomials to geometric topology. The proofs of these results appear in the papers (18, 19), while this survey focuses on the main ideas and examples. Introduction. To every knot in S 3 there corresponds a 3-manifold, namely the knot complement. This 3-manifold decomposes along tori into geometric pieces, where the most typical scenario is that all of S 3 r K supports a complete hyperbolic metric (43). Incompressible surfaces embedded in S 3 r K play a crucial role in understanding its
Sunspot Equilibria and Efficiency in Economies with Incomplete Financial Markets: A Remark

I consider economies with incomplete financial markets and nominal assets. I construct an economy where some sunspot equilibria strictly Pareto dominate a subset of nonsunspot equilibria and are not Pareto dominated by any nonsunspot equilibrium. Equilibria in the nonsunspot economy are not Pareto ranked. Journal of Economic Literature Classification Number: D52.
Chemical Approaches To Perturb, Profile, and Perceive Glycans

Glycosylation is an essential form of post-translational modification that regulates intracellular and extracellular processes. Regrettably, conventional biochemical and genetic methods often fall short for the study of glycans, because their structures are often not precisely defined at the genetic level. To address this deficiency, chemists have developed technologies to perturb glycan biosynthesis, profile their presentation at the systems level, and perceive their spatial distribution. These tools have identified potential disease biomarkers and ways to monitor dynamic changes to the glycome in living organisms. Still, glycosylation remains the underexplored frontier of many biological systems. In this Account, we focus on research in our laboratory that seeks to transform the study of glycan function from a challenge to routine practice. In studies of proteins and nucleic acids, functional studies have often relied on genetic manipulations to perturb structure. Though not directly subject to mutation...
A self-avoiding walk with attractive interactions

A self-avoiding walk with small attractive interactions is described here. The existence of the connective constant is established, and the diffusive behavior is proved using the method of the lace expansion.
Biosynthesis of the bicyclic depsipeptide salinamide A in Streptomyces sp. CNB-091: Origin of the carbons☆

Abstract The biosynthesis of the bicyclic depsipeptide salinamide A, a potent anti-inflammatory agent, in the marine bacterium Streptomyces sp. CNB-091 has been examined through feeding experiments with 13 C-labeled intermediates.
Catalytic, Enantioselective Alkylations of N,O- and N, N-Acetals and Hemiacetals

Abstract We report the first examples of catalytic, enantioselective alkylation of N,O-acetals to produce useful amino acid derivatives 5 in high yield (73–93%) and enantioselectivity (70–96%). We have extended the utility of our reaction to include a simple one-pot procedure from readily available starting materials. We also provide several different N-based protecting groups that greatly increase the flexibility of the reaction. In addition, we have elucidated novel mechanistic information including the discovery of unique transilylations that start off the catalytic reactions of enol silane nucleophiles with N,O-acetals. These details will guide us in further explorations of the reaction's scope and utility.
On the effects of parameterized Mediterranean overflow on North Atlantic ocean circulation and climate

Abstract A parameterized Mediterranean overflow, based on the marginal sea boundary condition of [Price, J., Yang, J., 1998. Marginal sea overflows for climate simulations. In: Chassignet, E.P., Verron, J., (Eds.), Ocean Modeling and Parameterization, Kluwer Academic, pp. 155–170], has been implemented in the ocean component of the Community Climate System Model to represent exchanges through the Strait of Gibraltar, associated entrainment and intrusion of overflow product water into the Atlantic. Previously, in coarse resolution model versions with a closed Strait, this physics has been either missing in uncoupled configurations or only partially and unphysically treated as a surface salt exchange when fully coupled. Parameter choices are evaluated by comparing climatologically forced solutions to observations and process model results. The two major criteria satisfied by the implementation in a fully coupled climate model and an uncoupled global ocean model are stable solutions and projection of the overflow signal across the Atlantic basin at about 1000 m depth. Both of these configurations are low resolution, and in both the transports of inflow, source and entrainment water are all within the range of observed estimates, but there is too little product water. This bias is attributed to inadequate modeling of water masses in the Mediterranean source region. Nevertheless, the properties of the product water differ little from observed estimates and both the uncoupled and coupled models develop a Mediterranean salt tongue that spreads west and south from the Strait with a signature reminiscent of the observed hydrography. The improvements relative to either blocking the Strait, or excavating a too wide channel are presented. In the coupled solution, the impact of the improved overflow physics on the global climate is minimal, with North Atlantic sea surface temperatures and heat fluxes changing generally by less than 1 °C and 15 W m −2 , respectively. However, there is interesting spatial variability in the coupling strength, which ranges between ±20 W m −2 °C −1 in the coupled case.
Bogoliubov dispersion relation for a `photon fluid': Is this a superfluid?

Abstract We discuss the possibility that photons, which are bosons, can form a 2D superfluid due to Bose–Einstein condensation inside a nonlinear Fabry–Perot cavity filled with atoms in their ground states. A `photon fluid' forms inside the cavity as a result of multiple photon–photon collisions mediated by the atoms during a cavity ring-down time. The effective mass and chemical potential for a photon inside this fluid are nonvanishing. This implies the existence of a Bogoliubov dispersion relation for the low-lying elementary excitations of the photon fluid, and in particular, that sound waves exist for long-wavelength, low-frequency disturbances of this fluid. Possible experiments to test for the superfluidity of the photon fluid based on the Landau critical-velocity criterion will be discussed.
Humble and Hopeful: Welcoming First-Generation Poor and Working-Class Students to College:

Students who are the first in their family to enter higher education join a rarified and often mystifying culture of rules, rites, and rituals. A first-generation working-class college student who became a faculty member offers his insights and recommendations after forty years in the academy.
Direct Liquid Coating of Chalcopyrite Light-Absorbing Layers for Photovoltaic Devices

Liquid deposition approaches for chalcopyrite films used in thin-film photovoltaic devices are reviewed. Most of the targeted materials are based on Cu-In or Cu-In-Ga sulfides and selenides (i.e., CIS or CIGS, respectively), although recently related alternative materials based on abundant and nontoxic elements such as the kesterite Cu 2 ZnSnS 4 have been actively investigated. By direct liquid coating we refer collectively to a variety of techniques characterized by distributing a liquid or a paste to the surface of a substrate, followed by necessary thermal/chemical treatments to achieve the desired phase. The deposition media used are solutions or particle (usually submicrometer size) suspensions of metal oxide, organic and inorganic compounds, including metal chalcogenide species. The deposition techniques used are mainly printing and spin-coating, although any standard process such as spraying, dip-coating or slit casting can be applied. In contrast to other widely investigated liquid-coating methods such as chemical bath and electrodeposition, in which relatively slower solid film growth occurs during the actual deposition step, the techniques discussed in this Microreview are mainly sequential, featuring rapid formation of a precursor film with well-defined metal stoichiometry. The precursor film is then transformed by a thermal treatment, generally in a chalcogen-containing atmosphere, to the final crystalline layer. This approach permits the use of low-cost and high-throughput equipment and the deployment of large-scale production facilities with lower capital investment. Although many of the methods discussed are under laboratory development, there are already industrial start-ups employing these promising methods for future large-scale photovoltaic production.
Chemistry and properties of novel niobium cluster compounds

Abstract Low-dimensional niobium chalcogenide halides provide interesting candidates for catalysis owing in part to their morphologies and electronic configuration. The synthesis, structures, properties, and electronic structures of novel compounds based on Nb3 triangles and Nb2 dimers are presented in this brief review. In addition, attempts at low temperature synthesis using organometallic precursors are discussed.
Hysteresis effect in floating-body partially depleted SOI CMOS domino circuits

This paper investigates in detail the basic mechanisms of hysteretic delay and noise margin variations for floating-body partially depleted SOI CMOS domino circuits. We first consider the ‘clock cycling scenario’, which completely eliminates (or isolates) the hysteresis effect of the output inverter, thus allowing one to observe and understand the hysteresis effect of the front-end domino logic stage. Three cases, based on whether the input signals are domino input signals, from other domino circuits, static input signals, from static circuits or latches; or a combination of domino and static input signals, are examined and differentiated. It is shown that hysteretic delay variation is the largest and the noise margin worst for the case with mixed domino and static input signals. Although the delay and noise margin disparities among the three types of input signals are significant at the beginning of the clock cycles, they converge as the circuit approaches steady state. The ‘data cycling scenario’ with t...
Laser radar development

This paper discusses the trends in laser radar development. Applications include reconnaissance and targeting from airborne and spaceborne platforms. A multifunction airborne sensor system, which includes a laser radar function with many modes, is defined. A multidiscriminant space borne laser radar is also described and its feasibility is assessed. A number proposed and existing Air Force programs to develop laser radar technology are described.
Thermodynamic perturbation theory: Sticky chains and square-well chains

We extend Wertheim's first-order thermodynamic perturbation theory [J. Chem. Phys. 87, 7323 (1987)] to sticky chains and square-well chains. The predicted compressibility factors for square-well chains are found to agree with Monte Carlo data. We demonstrate that the effect of chain connectivity is to reduce the attraction contributions to the compressibility factor and to the critical temperatures.
Novel failure analysis techniques using photon probing with a scanning optical microscope

Three new failure analysis techniques for integrated circuits (ICs) have been developed using localized photon probing with a scanning optical microscope (SOM). The first two are light-induced voltage alteration (LIVA) imaging techniques that (1) localize open-circuited and damaged junctions and (2) image transistor logic states. The third technique uses the SOM to control logic states optically from the IC backside. LIVA images are produced by monitoring the voltage fluctuations of a constant current power supply as a laser beam is scanned over the IC. High selectivity for localizing defects has been demonstrated using the LIVA approach. Logic state mapping results, similar to previous work using biased optical beam induced current (OBIC) and laser probing approaches, have also been produced using LIVA. Application of the two LIVA based techniques to backside failure analysis has been demonstrated using an infrared laser source. Optical logic state control is based upon earlier work examining transistor response to photon injection. The physics of each method and their applications for failure analysis are described. >
Synthesis of tetrahydropyridazino[1,2‐a][1,2,4] benzotriazin‐6‐one derivatives. A novel heterocyclic system

Synthesis of pyridazino[1,2-a][1,2,4]benzotriazin-6-one derivatives involving reaction of either 1,2,3,6-tetra-hydropyridazine (9) or hexahydropyridazine 14 with 2-fluoro-5-nitrophenylisocyanate (5) to give, via intramolecular cyclization, 3a and 16 respectively is described. Compound 3a was converted to 18 via methylation and hydroxylation to give 20 followed by conversion to the acetonide derivative 18. Both 16 and 18 were reduced to the amino derivatives 17 and 19 respectively.
Neighboring Extremal Control Design Using Error Compensation

Error compensation, which has been used to improve the performance of approximate analytical optimal controls, is extended to neighboring extremal control. The optimal control problem with error compensation is de ned, the  rst variation conditions are linearized about an optimal path to account for perturbations in the initial state and the  nal constraint manifold, and the neighboring extremal control is derived. A vehicle guidance example demonstrates that the tuning procedure inherent in error compensation moves the performance of the derived control toward that of a numerically determined piecewise-linear optimal control.
Large cardinals with few measures

We show, assuming the consistency of one measurable cardinal, that it is consistent for there to be exactly κ + many normal measures on the least measurable cardinal K. This answers a question of Stewart Baldwin. The methods generalize to higher cardinals, showing that the number of A strong compactness or A supercompactness measures on P κ (λ) can be exactly λ + if λ > K is a regular cardinal. We conclude with a list of open questions. Our proofs use a critical observation due to James Cummings.
Geothermal characteristics of the colorado plateau

New heat-flow measurements in the Colorado Plateau varying in depth from 400 to 1900 m suggest that the heat flux throughout the region is 1.5 HFU and greater (1 HFU = 41.8 mW/m2). Along the eastern and southern boundaries of the Plateau, near the San Juan volcanic field and the Mogollon Slope respectively, high heat flows ($2.2 HFU) are observed to intrude 50–100 km into the Plateau. It is believed that the high heat flows are associated with the sources of the volcanics in those areas. In the interior areas of the Plateau, away from the major volcanic phenomena along its boundary (e.g., the Black Mesa—Kaiparowits synclinorium, the Four Corners area, and the Piceance and Uinta basins) heat flows are generally between 1.5 and 1.8 HFU, and appear to be rather uniform over large areas. This uniform heat-flow characteristic over large areas of the interior Plateau suggests the lack of large-scale, widespread, crustal thermal sources as in the Basin and Range or along the Rio Grande rift. It is possible that lithospheric temperatures within the Colorado Plateau were once similar to lithospheric temperatures within the Stable Interior. Present heat-flow differences between the two provinces (~0.4 HFU) may define the temperature change occurring in the lithosphere of the Colorado Plateau over the past 200 m.y. This temperature change may have contributed significantly to the uplifting of the Colorado Plateau by the process of thermal expansion.