cssi/SciSciGPT-SciSciNet huggingface dataset:
Calibrations associated to Monge-Ampère equations

We show the volume maximizing property of the special Lagrangian submanifolds of a pseudo-Euclidean space. These special Lagrangian submanifolds arise locally as gradient graphs of solutions to Monge-Ampere equations.
Effect of environmental conditions on the stiction behavior of laser textured hard disk media

Abstract The effect of relative humidity and temperature on the stiction behavior of laser textured and mechanically textured hard disk media is investigated using contact–start–stop testing. The coefficient of stiction for mechanically textured media was found to increase dramatically at high humidity while it remained nearly unchanged for laser textured media. A physical model is used to explain the differences in the stiction behavior between laser textured and mechanically textured media as a function of relative humidity. The model suggests that the differences between laser textured and mechanically textured media are due to the different bearing characteristics of the two types of media. The effect of increasing temperature was found to reduce stiction at high humidity for mechanically textured media. The effect of temperature on stiction appears to be related to changes in lubricant properties with temperature.
On the topology of components of some Springer fibers and their relation to Kazhdan¿Lusztig theory

Abstract We describe the irreducible components of Springer fibers for hook and two-row nilpotent elements of gl n ( C ) as iterated bundles of flag manifolds and Grassmannians. We then relate the topology (in particular, the intersection homology Poincare polynomials) of the pairwise intersections of these components with the inner products of the Kazhdan–Lusztig basis elements of irreducible representations of the rational Iwahori–Hecke algebra of type A corresponding to the hook and two-row Young shapes.
Influence of substrate topography on the nucleation of diamond thin films

We have investigated the effect of substrate topography on nucleation behavior by producing a variety of substrate features on molybdenum and silicon substrates. The initial stages of nucleation on these substrates were studied by exposing them to similar conditions in a hot filament chemical vapor deposition reactor. For these materials, nucleation is favored on prominent features of the substrate; that is, features that protrude with sharp edges or apexes, as opposed to sharp valleys or flat regions. Several possible explanations are given for this behavior.
A Comparison of Transaction Cost, Agency, and Knowledge-Based Predictors of IT Outsourcing Decisions: A U.S.-Japan Cross-Cultural Field Study

As outsourcing evolves into a competitive necessity, managers must increasingly contend with the decision about which software development projects to outsource. Although a variety of theories have been invoked to study the initial outsourcing decision, much of this work has relied in isolation on one theoretical perspective. Therefore, the relative importance ascribed by managers to the factors from these theories is poorly understood. The majority of this work also masks interesting insights into outsourcing decisions by focusing on the information technology (IT) function rather than individual projects as the unit of analysis, where many of these decisions occur. In contrast, prior research at the project level has focused on predicting development performance in the postoutsourcing-decision phases of projects. The objective of this study is to examine the relative importance that IT managers ascribe to various factors from three complementary theories-transaction cost economics, agency theory, and knowledge-based theory-as they simultaneously consider them in their project outsourcing decisions. A secondary objective is to assess the cross-cultural robustness (United States versus Japan in this study) of such models in predicting project-level IT outsourcing decisions. We develop and test a multitheoretic model using data on 1,008 project-level decisions collected from 33 Japanese and 55 U.S. managers. Overall, our results provide novel insights into the relative importance that managers ascribe to the factors from these three theories, their complementarities and occasional contradictions, and offer new insights into the differences among U.S. and Japanese IT managers. Implications for theory and practice are also discussed.
Chandra X-Ray Sources in the Collapsed-Core Globular Cluster M30 (NGC 7099)

We report the detection of six discrete, low-luminosity (LX < 1033 ergs s-1) X-ray sources, located within 12'' of the center of the collapsed-core globular cluster M30 (NGC 7099), and a total of 13 sources within the half-mass radius, from a 50 ks Chandra ACIS-S exposure. Three sources lie within the very small upper limit of 1.9'' on the core radius. The brightest of the three core sources has a luminosity of LX(0.5-6 keV) ≈ 6 × 1032 ergs s-1 and a blackbody-like soft X-ray spectrum, which are both consistent with it being a quiescent low-mass X-ray binary (qLMXB). We have identified optical counterparts to four of the six central sources and a number of the outlying sources, using deep Hubble Space Telescope and ground-based imaging. While the two proposed counterparts that lie within the core may represent chance superpositions, the two identified central sources that lie outside of the core have X-ray and optical properties consistent with being cataclysmic variables (CVs). Two additional sources outside of the core have possible active binary counterparts. We discuss the X-ray source population of M30 in light of its collapsed-core status.
PSL(n|n) sigma model as a conformal field theory

Abstract We discuss the sigma model on the PSL ( n | n ) supergroup manifold. We demonstrate that this theory is exactly conformal. The chiral algebra of this model is given by some extension of the Virasoro algebra, similar to the W algebra of Zamolodchikov. We also show that all group invariant correlation functions are coupling constant independent and can be computed in the free theory. The non-invariant correlation functions are highly non-trivial and coupling dependent. At the end we compare two- and three-point correlation functions of the PSL (1, 1|2) sigma model with the correlation functions in the boundary theory of AdS 3 × S 3 and find a qualitative agreement.
A study of detonation diffraction in the ignition-and-growth model

Heterogeneous high-energy explosives are morphologically, mechanically and chemically complex. As such, their ab initio modelling, in which well-characterized phenomena at the scale of the microstructure lead to a rationally homogenized description at the much larger scale of observation, is a subject of active research but not yet a reality. An alternative approach is to construct phenomenological models, in which forms of constitutive behaviour are postulated with an eye on the perceived picture of the micro-scale phenomena, and which are strongly linked to experimental calibration. Most prominent among these is the ignition-and-growth model conceived by Lee and Tarver. The model treats the explosive as a homogeneous mixture of two distinct constituents, the unreacted explosive and the products of reaction. To each constituent is assigned an equation of state, and a single reaction-rate law is prescribed for the conversion of the explosive to products. It is assumed that the two constituents are always ...
Update: Transmission of HIV-1 from mother to child

Mother-to-child transmission near the time of birth is the primary route of HIV-1 infection among infants and young children. Throughout the world, 1000 babies a day become infected with HIV, and cumulative global estimates are that 3 million children have been infected since the HIV pandemic began. Although major advances have been made in reducing mother-to-child transmission of HIV-1 in the USA and Europe through the use of an intensive regimen of zidovudine, many research questions remain unresolved. These include (1) viral and host characteristics which hinder or facilitate perinatal HIV transmission (i.e. the role played by viral load, the placenta and obstetric risk factors); (2) the proportion of transmission occurring in utero, intrapartum or during the breast feeding period; and (3) the mode of action of the successful zidovudine regimen. Studies published within the past year have shed light on several of these research topics. In 1996-1997 a number of important studies were published which support a general correlation between maternal viral load and infant HIV infection. The most recent studies do not, however, support the theory that there is a threshold below which transmission cannot occur, and also indicate that zidovudine, given according to the US Public Health Service guidelines, can significantly reduce the risk of transmission across all levels of maternal viral load. Analyses of viral load data from the successful clinical trial with zidovudine (AIDS Clinical Trial Group 076) suggest that its primary action is not by reducing the viral load, and raise the possibility that administering antiretroviral prophylaxis to the infant at the time of highest exposure may be another reason for the reduction in transmission. Obstetric risk factors for mother-to-child HIV transmission have been evaluated in several large cohort studies. A duration of membrane rupture of more than 4 h, and procedures such as amniocentesis, preterm labor, and the presence of sexually transmitted diseases during pregnancy were found to be significant risk factors. Still unresolved is the potential protective effect of cesarean section in reducing the risk of transmission. Likewise, the role played by the placenta in preventing or facilitating perinatal transmission is not well understood, and requires further research. This year did see the publication of consistent findings from diverse geographical regions regarding the probable timing of perinatal HIV transmission. On the basis of the timing of the first infant positive polymerase chain reaction or culture, most transmission would appear to occur around the intrapartum or very late prenatal period, and only approximately 12-14% is related to breast feeding. These advances should help focus and refine future research efforts to reduce mother-to-child HIV transmission worldwide.
Interactions between charged spheres in divalent counterion solution

Abstract We simulate model systems of charged spherical particles in their counterion solution and measure the thermodynamic pressure and the pair distribution function from which we derive effective potentials of mean force. For a system with only electrostatic and hard core interactions, we investigate the effective potential between two like-charged spheres in divalent counterion solution as a function of concentration. We find a strong attractive interaction for high concentration and a global repulsive effective interaction for dilute systems. The results indicate a first order phase transition in sphere–counterion density as a function of global concentration and the effective sphere–sphere potentials in the dilute (solvated) regime suggest significant density fluctuations due to short range local minima in the effective energy surface. Our results arise from a minimal approach model of several recent experiments on polystyrene latex particles in monovalent counterion solution.
The perils of peer effects

Abstract Individual outcomes are highly correlated with group average outcomes, a fact often interpreted as a causal peer effect. Without covariates, however, outcome-on-outcome peer effects are vacuous, either unity or, if the average is defined as a leave-out mean, determined by a generic intraclass correlation coefficient. When pre-determined peer characteristics are introduced as covariates in a model linking individual outcomes with group averages, the question of whether peer effects or social spillovers exist is econometrically identical to that of whether a 2SLS estimator using group dummies to instrument individual characteristics differs from OLS estimates of the effect of these characteristics. The interpretation of results from models that rely solely on chance variation in peer groups is therefore complicated by bias from weak instruments. With systematic variation in group composition, the weak IV issue falls away, but the resulting 2SLS estimates can be expected to exceed the corresponding OLS estimates as a result of measurement error and for other reasons unrelated to social effects. Research designs that manipulate peer characteristics in a manner unrelated to individual characteristics provide the most compelling evidence on the nature of social spillovers. As an empirical matter, designs of this sort have mostly uncovered little in the way of socially significant causal effects.
Runaway Heating by r-Modes of Neutron Stars in Low-Mass X-Ray Binaries

Recently Andersson et al. and Bildsten have independently suggested that an r-mode instability might be responsible for stalling the neutron star spin-up in strongly accreting low-mass X-ray binaries (LMXBs). We show that if this does occur, there are two possibilities for the resulting neutron star evolution. If the r-mode damping is a decreasing function of temperature, then the star undergoes a cyclic evolution: (1) accretional spin-up triggers the instability near the observed maximum spin rate; (2) the r-modes become highly excited through gravitational radiation reaction, and in a fraction of a year (0.13 yr in a particular model that we have considered) they viscously heat the star up to T~2.5 × 109 K; (3) r-mode gravitational radiation reaction then spins the star down in tspindown0.08(ffinal/130 Hz)−6 yr to a limiting rotational frequency ffinal, whose exact value depends on the not fully understood mechanisms of r-mode damping; (4) the r-mode instability shuts off; and (5) the neutron star slowly cools and is spun up by accretion for ~5 × 106 yr, until it once again reaches the instability point, closing the cycle. The shortness of the epoch of r-mode activity makes it unlikely that r-modes are currently excited in the neutron star of any galactic LMXBs, and unlikely that advanced LIGO interferometers will see gravitational waves from extragalactic LMXBs. Nevertheless, this cyclic evolution could be responsible for keeping the rotational frequencies within the observed LMXB frequency range. If, on the other hand, the r-mode damping is temperature independent, then a steady state with constant angular velocity and Tcore 4 × 108 K is reached, in which r-mode viscous heating is balanced by neutrino cooling and accretional spin-up torque is balanced by gravitational radiation reaction spin-down torque. In this case (as Bildsten and Andersson et. al. have shown) the neutron stars in LMXBs could be potential sources of periodic gravitational waves, detectable by enhanced LIGO interferometers.
MR Imaging in Congenital and Acquired Disorders of the Pediatric Upper Extremity

Various congenital and acquired disorders can affect the upper extremity in pediatric and adolescent patients. MR imaging can provide unique anatomic and diagnostic information in the evaluation of many of these disorders, including inflammatory, infectious, neoplastic, and arthritic conditions. This article rounds out the issue on pediatric musculoskeletal MR imaging. It focuses on the evaluation of more common congenital disorders, and mainly sports-related injuries of the shoulder, elbow, and wrist in children. MR imaging can be more challenging in diagnosis of some of these disorders. Features of overuse injuries in skeletally immature athletes are a unifying theme throughout the article.
HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES

We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T_(eff) > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.
Structures, function and applications of amphiphilic peptides

Major recent advances: Amphiphilic peptides, in other words, peptides that contain hydrophobic and hydrophilic regions along their lengths, have been molecularly designed and exploited in various ways. Most notable advancements in the past few years are their proposed use for scaffolds for nanometer structures such as molecular wires and mineralization of hydroxyapatite crystals in a particular orientation. Our group has also designed a new class of short and simple surfactant-like peptides that self-assemble into well-defined nanotubes and nanovesicles.
Large silicon clusters: confirmation of Phillips' conjecture

Abstract This paper attempts to verify the hypothesis put forward by Phillips that large silicon clusters are arranged in a cylindrical shape, as stacked quasigraphitic rings. It is shown that the periodic variations in reactivity can probably be explained by this hypothesis. A tight-binding calculation is employed, and the geometry and charge distribution of clusters ranging in size from 30 to 45 atoms is explored.
Microstructure development in high-temperature Mo-Si-B alloys

Mo-Si-B alloys are considered as potential high temperature structural materials due to their high melting points (above 2000°C) and excellent oxidation resistance attributed to their self-healing characteristics over an extended temperature range. In the current study, the effect of alloying additions to achieve lower weight density and microstructure stability has been examined. The critical factor to the alloying additions appears to be the stability of the high melting ternary-based T 2 borosilicide phase.
Sensitization versus tolerance to the dopamine turnover-elevating effects of haloperidol: the effect of regular/intermittent dosing

Recent clinical research suggests that particular patterns of changes in presynaptic dopamine (DA) turnover accompany the therapeutic response to neuroleptics. We sought to determine whether daily versus weekly dosing of haloperidol for 3 weeks produced distinct effects on DA, dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) concentrations in multiple brain areas. Daily dosing favored the development of tolerance to the DA-turnover elevating effects of haloperidol in the striatum and nucleus accumbens. Weekly dosing favored the development of sensitization in the striatum, posterior olfactory tubercle, and ventral tegmental area. These results suggest that dosing schedules may determine, at least in part, the effects of chronic neuroleptic administration on presynaptic DA function.
Integrals of the Motion for Optimal Trajectories in Atmospheric Flight

The problem of optimizing the flight trajectory of a rocket vehicle moving in a resisting medium, in a general gravitational force field, is considered. Optimal laws for the modulation of the aerodynamic and propulsive forces are formulated in terms of the primer vector, the vector adjoint to the velocity. Relations for flight along an intermediate-thrust arc and integrals of the motion for several cases of practical interest are derived.
Legal Liability Coverage and Voluntary Disclosure

ABSTRACT: This paper examines whether legal liability coverage, as measured by excess Directors’ and Officers’ (D&O) liability insurance coverage and excess cash for indemnification, is associated with the quantity and the quality of a firm’s voluntary disclosures. Using Canadian firms whose D&O insurance data are publicly available, I find that firms with higher excess coverage are less likely to report bad news forecasts for the sample firms that are cross-listed in the U.S., and that the number of bad news forecasts decreases for large cross-listed sample firms having high litigation risk. The results are consistent with the litigation cost argument for the disclosure of bad news. I also find that higher excess liability coverage leads to disclosures of more precise bad news for the cross-listed sample firms and less timely disclosures of bad news for large cross-listed sample firms. Further, excess cash for indemnification is a more significant determinant of disclosure decisions.
The chemistry of 4‐pyrimidinones: Acetylation and ring‐opening reactions

4(3H)-Pyrimidinone, as well as its 5-acetoxy and 5-methoxy derivatives, undergoes selective acetylation at N-1 when treated with acetic anhydride. In the presence of water, these 1-acetylpyrimidines undergo spontaneous covalent hydration at C-2 and cleavage of the 1,2-bond to give crystalline cis-3-acetylamino-N-formyl-acrylamides, generally in good yield. In contrast, the 6-methyl derivative of 4(3H)-pyrimidinone forms an equilibrium mixture of acetylated products that undergo the ring opening process to only a very limited extent, the major product (11%) being the 3-formylamino-N-acetylacrylamide derivative formed via N-3 acetylation and cleavage of the 2,3-bond.
Extracting Web Data Using Instance-Based Learning

This paper studies structured data extraction from Web pages. Existing approaches to data extraction include wrapper induction and automated methods. In this paper, we propose an instance-based learning method, which performs extraction by comparing each new instance to be extracted with labeled instances. The key advantage of our method is that it does not require an initial set of labeled pages to learn extraction rules as in wrapper induction. Instead, the algorithm is able to start extraction from a single labeled instance. Only when a new instance cannot be extracted does it need labeling. This avoids unnecessary page labeling, which solves a major problem with inductive learning (or wrapper induction), i.e., the set of labeled instances may not be representative of all other instances. The instance-based approach is very natural because structured data on the Web usually follow some fixed templates. Pages of the same template usually can be extracted based on a single page instance of the template. A novel technique is proposed to match a new instance with a manually labeled instance and in the process to extract the required data items from the new instance. The technique is also very efficient. Experimental results based on 1,200 pages from 24 diverse Web sites demonstrate the effectiveness of the method. It also outperforms the state-of-the-art existing systems significantly.
Fullerenes C60 and C70 in flames.

THE fullerenes C60 and C70 were first identified1 in carbon vapour produced by laser irradiation of graphite, and have recently been produced in macroscopic quantities2–5 by vaporization of graphite with resistive heating. It has also been suggested6–9 that fullerenes might be formed in sooting flames, and indeed all-carbon ions with mass/charge ratios suggestive of fullerenes have been detected in flames10–12. These species were assumed to have the cage structures of fullerenes, but the mass spectroscopic evidence could not establish this conclusively. We have now collected samples of condensible compounds and soot from hydrocarbon combustion under a range of conditions, and analysed these using conventional techniques in an effort to detect fullerenes. Spectroscopic studies reveal the presence of C60 and C70 in yields and ratios that depend on temperature, pressure, carbon/oxygen ratio and residence time in the flame. Control of these conditions allows optimal yields of 3 g of fullerenes per kilogram of fuel carbon burned, and variation of the C70/C60 ratio over the range 0.26–5.7.
NGC 4138: A Case Study in Counterrotating Disk Formation

The Sa(r) galaxy NGC 4138 has been recently found to contain an extensive counterrotating disk that appears to be still forming. Up to one-third of the stars in the disk system may be on retrograde orbits. A counterrotating ring of H II regions, along with extended counterrotating H I gas, suggests that the retrograde material has been recently acquired in the gas phase and is still trickling in. Using numerical simulations, we have attempted to model the process by which the counterrotating mass has been accreted by this galaxy. We investigate two possibilities: continuous retrograde infall of gas and a retrograde merger with a gas-rich dwarf galaxy. Both processes are successful in producing a counterrotating disk of the observed mass and dimensions without heating up the primary disk significantly. Contrary to our experience with a fiducial cold, thin primary disk, the gas-rich merger works well for the massive, compact primary disk of NGC 4138 even though the mass of the dwarf galaxy is a significant fraction of the mass of the primary disk. Although we have restricted ourselves mainly to coplanar infall and mergers, we report on one inclined infall simulation as well. We also explore the possibility that the Hα ring seen in the inner half of the disk is a consequence of counterrotating gas clouds colliding with corotating gas already present in the disk and forming stars in the process.
Transition metal tetrahydridoborates as models of methane activation: synthesis and structure of Ti(BH4)3(PMe3)2

The X-ray crystal structure of Ti(BH4)3(PMe3)2 shows that two of the BH4– groups possess unusual geometries involving interaction of the titanium centre with one B–H bond in a ‘side-on’ manner; this geometry resembles one proposed transition state for the approach of a molecule of methane to a transition metal leading to C–H bond cleavage.
Spillover Effects of Inclusion of Classmates with Emotional Problems on Test Scores in Early Elementary School.

Over the last decade, the federal government has directed schools to provide educational instruction for students with special needs in general education settings to the extent possible. While there is mixed evidence on the effects of these inclusion policies on the students with special needs, research examining potential spillovers of inclusion on non-disabled classmates has been scarce. There is particularly little research on the effects of inclusion policies on classmates during early elementary grades. This paper begins to fill in this gap by using a nationally representative, longitudinal survey of kindergartners. Cross-sectional results suggest that having a classmate with an emotional problem decreases reading and math scores at the end of kindergarten and first grade by over 10 percent of a standard deviation, which is one-third to one-half of the minority test score gap. To control for nonrandom sorting of students to schools, as well as students to classrooms, this paper uses school-level and then student-level fixed effects. Results from the preferred empirical models suggest a decrease of approximately 5 percent of a standard deviation in math and reading scores, though the reading results are less robust. The results also indicate moderate racial and gender differences in the effects. © 2010 by the Association for Public Policy Analysis and Management.
A new consistent spatial differencing scheme for the transonic full-potential equation

A new spatial differencing scheme for the transonic full-potential equation in conservative form has been developed. Three consistency conditions for the full-potential equations are derived and are satisifed by the new scheme. This scheme guarantees zero truncation error on any curvilinear mesh for freestream flows in either two- or three-space dimensions. Solutions obtained with this new differencing scheme, away from freestream regions, exhibit greatly improved accuracy, especially for nonsmooth or singular meshes. The computing times associated with the new scheme are approximately the same as the less accurate old scheme when computations are performed on the same mesh.
Functional Upregulation of Ca2+ -Activated K+ Channels in the Development of Substantia Nigra Dopamine Neurons

Many connections in the basal ganglia are made around birth when animals are exposed to a host of new affective, cognitive, and sensori-motor stimuli. It is thought that dopamine modulates cortico-striatal synapses that result in the strengthening of those connections that lead to desired outcomes. We propose that there must be a time before which stimuli cannot be processed into functional connections, otherwise it would imply an effective link between stimulus, response, and reward in uterus. Consistent with these ideas, we present evidence that early in development dopamine neurons are electrically immature and do not produce high-frequency firing in response to salient stimuli. We ask first, what makes dopamine neurons immature? and second, what are the implications of this immaturity for the basal ganglia? As an answer to the first question, we find that at birth the outward current is small (3nS-V), insensitive to Ca(2+), TEA, BK, and SK blockers. Rapidly after birth, the outward current increases to 15nS-V and becomes sensitive to Ca(2+), TEA, BK, and SK blockers. We make a detailed analysis of the kinetics of the components of the outward currents and produce a model for BK and SK channels that we use to reproduce the outward current, and to infer the geometrical arrangement of BK and Ca(2+) channels in clusters. In the first cluster, T-type Ca(2+) and BK channels are coupled within distances of ~20 nm (200 A). The second cluster consists of L-type Ca(2+) and BK channels that are spread over distances of at least 60 nm. As for the second question, we propose that early in development, the mechanism of action selection is in a "locked-in" state that would prevent dopamine neurons from reinforcing cortico-striatal synapses that do not have a functional experiential-based value.
Continued enhancements to the commercial atlas launch system

Abstract Since the October 1988 update on the Commercial Atlas Launch System presented to the IAF, additional enhancements have been incorporated into the launch vehicles offered. Previous papers have dealt with performance and configuration details of the Atlas I, II, IIA launch vehicles. This paper discusses the latest addition to the line of Atlas launch vehicles, namely the Atlas IIAS, and other enhancements that have been made across the board. Discussion of the Atlas IIAS configuration includes details about structural upgrades made to the booster stage, the basic configuration of the solid rocket motors (SRMs) used, upgrades made to the launch facility, effects of the configuration change on spacecraft environments, and overall performance enhancement. By selective incorporation of the enhancement available, the performance of Atlas launch vehicles can be tailored to the specified requirements of particular missions. These capability enhancements include minimum residual shutdown of the Centaur upper stage, transverse spin separation, and small payload accommodations (SPA). When matched with existing capabilities of in-flight retargeting and precision pointing and injection accuracies, these improvements lead to the availability of a launch vehicle that can be tailored to a spacecraft's unique requirements. Finally, a review of performance capabilities for the entire line of Atlas launch vehicles is presented, capping a comprehensive view of the current state of the Atlas launch vehicle.
s‐tetrazine: Coupling of the S0 to the S1 electronic state by two out‐of‐plane b3u vibrations

Large effects of vibronic coupling upon vibrational levels of the ground and first excited singlet states of s‐tetraazabenzene‐d0 and d2 are successfully modelled. The model is used also in discussing observed large radiationless transition probabilities and some anomalous infrared and visible transition probabilities.
Muscle length and myonuclear position are independently regulated by distinct Dynein pathways

Various muscle diseases present with aberrant muscle cell morphologies characterized by smaller myofibers with mispositioned nuclei. The mechanisms that normally control these processes, whether they are linked, and their contribution to muscle weakness in disease, are not known. We examined the role of Dynein and Dynein-interacting proteins during Drosophila muscle development and found that several factors, including Dynein heavy chain, Dynein light chain and Partner of inscuteable, contribute to the regulation of both muscle length and myonuclear positioning. However, Lis1 contributes only to Dynein-dependent muscle length determination, whereas CLIP-190 and Glued contribute only to Dynein-dependent myonuclear positioning. Mechanistically, microtubule density at muscle poles is decreased in CLIP-190 mutants, suggesting that microtubule-cortex interactions facilitate myonuclear positioning. In Lis1 mutants, Dynein hyperaccumulates at the muscle poles with a sharper localization pattern, suggesting that retrograde trafficking contributes to muscle length. Both Lis1 and CLIP-190 act downstream of Dynein accumulation at the cortex, suggesting that they specify Dynein function within a single location. Finally, defects in muscle length or myonuclear positioning correlate with impaired muscle function in vivo, suggesting that both processes are essential for muscle function.
A space efficient streaming algorithm for triangle counting using the birthday paradox

We design a space efficient algorithm that approximates the transitivity (global clustering coefficient) and total triangle count with only a single pass through a graph given as a stream of edges. Our procedure is based on the classic probabilistic result, the birthday paradox. When the transitivity is constant and there are more edges than wedges (common properties for social networks), we can prove that our algorithm requires O(√n) space (n is the number of vertices) to provide accurate estimates. We run a detailed set of experiments on a variety of real graphs and demonstrate that the memory requirement of the algorithm is a tiny fraction of the graph. For example, even for a graph with 200 million edges, our algorithm stores just 60,000 edges to give accurate results. Being a single pass streaming algorithm, our procedure also maintains a real-time estimate of the transitivity/number of triangles of a graph, by storing a miniscule fraction of edges.
Synthesis of the antitumor antibiotic FR-66979: Dmitrienko oxidative expansion of a fully functional core structure

Abstract A stereocontrolled synthesis of the pentacyclic ring system 18 , a projected advanced intermediate in the synthesis of FR-66979 ( 2 ), has been achieved. Key steps in the assembly of 18 include a copper(I) mediated cylization-oxidation of diazoketone 6 to mitosene 16 followed by an oxidative expansion of 16 to 18 . The latter transformation proceeds via N-oxidation of diol 17 .
AN INTRINSIC DESCRIPTION OF UNSTEADY SHOCK WAVES

Abstract : In this paper the intent is to obtain, insofar as possible, an intrinsic description of shock propagation, that is to say, a description such that the motion and the evolution of the amplitude of the shock are determined by quantities known on the shock itself. Such a description would parallel the results of geometrical acoustics, but with significant differences.
A WISE VIEW OF STAR FORMATION IN LOCAL GALAXY CLUSTERS

We present results from a systematic study of star formation in local galaxy clusters using 22 μm data from the Wide-field Infrared Survey Explorer (WISE). The 69 systems in our sample are drawn from the Cluster Infall Regions Survey, and all have robust mass determinations. The all-sky WISE data enable us to quantify the amount of star formation, as traced by 22 μm, as a function of radius well beyond R_(200), and investigate the dependence of total star formation rate upon cluster mass. We find that the fraction of star-forming galaxies increases with cluster radius but remains below the field value even at 3R_(200). We also find that there is no strong correlation between the mass-normalized total specific star formation rate and cluster mass, indicating that the mass of the host cluster does not strongly influence the total star formation rate of cluster members.
The structure of aniline

Abstract The fully optimized equilibrium structure of aniline has been evaluated by Hartree—Fock gradient calculations using a 4–21 split valence shell basis set augmented by a set of d functions on the nitrogen atom. The optimization was repeated with two sets of d functions on nitrogen and single-point calculations have been made with d functions on all heavy atoms and with the latter set supplemented by a second set of polarization functions on nitrogen. Full geometry optimizations have also been made at the transition states for rotation and for inversion of the amine group. The small ring asymmetries deduced from analysis of the microwave spectrum are confirmed and compared with generalizations about variation of ring asymmetry with electronegativity of the substituent group. The angle between the amine group and the benzene ring is found to be approximately 52–55°, in contrast to the experimentally reported 37.6 ± 2.0°, and possible explanations for this major discrepancy are considered. Energy barriers for inversion and amine group rotation, dipole moments, and vertical ionization potentials are given.
The Hubble expansion is isotropic in the epoch of dark energy

The isotropy of the universal Hubble expansion is a fundamental tenet of physical cosmology, but it has not been precisely tested during the current epoch, when dark energy is dominant. Anisotropic expansion will produce a shearing velocity field, causing objects to stream toward directions of faster expansion and away from directions of slower expansion. This work tests the basic cosmological assumption of isotropic expansion and thus the isotropy of dark energy. The simplest anisotropy will manifest as a quadrupolar curl-free proper motion vector field. We derive this theoretical signature using a tri-axial expanding metric with a flat geometry (Bianchi I model), generalizing and correcting previous work. We then employ the best current data, the Titov & Lambert (2013) proper motion catalog of 429 objects, to measure the isotropy of universal expansion. We demonstrate that the Hubble expansion is isotropic to 7% (1 $\sigma$), corresponding to streaming motions of 1 microarcsecond/yr, in the best-constrained directions (-19% and +17% in the least-constrained directions) and does not significantly deviate from isotropy in any direction. The Gaia mission, which is expected to obtain proper motions for 500,000 quasars, will likely constrain the anisotropy below 1%.
An M-Theory Perspective on Heterotic K3 Orbifold Compactifications

We analyze the structure of heterotic M-theory on K3 orbifolds by presenting a comprehensive sequence of M-theoretic models constructed on the basis of local anomaly cancellation. This is facilitated by extending the technology developed in our previous papers to allow one to determine "twisted" sector states in nonprime orbifolds. These methods should naturally generalize to four-dimensional models, which are of potential phenomenological interest.
The large coil task and results of testing U.S. coils

The United States, EURATOM, Japan, and Switzerland have collaborated since 1978 in development of superconducting toroidal field coils for fusion reactor applications. The United States provided a test facility and three coils; the other participants, one coil each. All coils have the same interface dimensions and performance requirements (stable at 8 T), but internal design was decided by each team. Two U.S. coil teams chose bath-cooled NbTi, 10-kA conductors. One developed a Nb 3 Sn conductor, cooled by internal flow, rated at 18 kA. All U.S. coils have diagnostic instrumentation and imbedded heaters that enable stability tests and simulated nuclear heating experiments. In single-coil tests, each coil operated at full current in self-field (6.4 T). In six-coil tests that began in July 1986, one U.S. coil and the Japanese coil have been successfully operated at full current at 8 T. The other coils have operated as background coils while awaiting their turn as test coil. Coil tests have been informative and results gratifying. The facility has capably supported coil testing and its operation has provided information that will be useful in designing future fusion systems. Coil capabilities beyond nominal design points will be determined.
The Radio Quiescence of Active Galaxies with High Accretion Rates

We present 6 cm Very Large Array observations of the Greene & Ho sample of 19 low-mass active galaxies with high accretion rates. This is one of the only studies of a uniform sample of narrow-line Seyfert 1 (NLS1) galaxies with such high sensitivity and resolution. Although we detect only one source, the entire sample is very radio quiet down to strong limits. GH 10 was found to have a radio power of 8.5 × 1021 W Hz-1 and a ratio R ≡ f6 cm/f4400 A of 2.8. The 3 σ upper limits for the remaining nondetections correspond to radio powers from 3 × 1020 to 8 × 1021 W Hz-1 and 0.47 < R < 9.9. Stacking all nondetections yields an even stronger upper limit of R ≤ 0.27. An assessment of existing observations in the literature confirms our finding that NLS1s are consistently radio-quiet, with a radio-loud fraction of 0%-6%, which is significantly lower than the 10%-20% observed in the general quasar population. By analogy with stellar mass black holes, we argue that AGNs undergo a state transition at Lbol/LEdd ≈ 0.01. Below this value a radiatively inefficient accretion flow effectively drives an outflow, which disappears when the flow turns into an optically thick, geometrically thin disk, or a radiation pressure-dominated slim disk at still higher Lbol/LEdd.
Machine Characterization Based on an Abstract High-level Language Machine

A linear performance model decomposes program execution into n distinct operations, such as adds, multiplies, loads, and stores. A program is characterized as an n-vector of operation counts, and a machine is characterized as an n-vector of operation times. The dot-product of the two is the time required for the machine to execute the program. A linear performance model has several uses:1. Once every machine and program is characterized, the performance of each program on each machine can be predicted without having to run them.2. Two machines (or programs) can be compared by comparing corresponding elements of their parameter vectors. The influence of individual parameters on overall performance can be used to predict the effect of design changes.3. Machines (and programs) can be classified by the similarity of their parameter vectors.
Is FDI Integrating the World Economy

FDI's spectacular growth, in diverse forms, during the past two decades represented an important force generating greater economic integration. FDI increased substantially in relation to global productive capacity, cross border mergers and acquisitions component of FDI put domestic corporate laggards on notice, and the spread of FDI to non-tradable service sectors generated the possibility that these traditionally low productivity sectors would be brought closer to the standards of international efficiency. Yet, FDI did not perform an integrating role in a more fundamental sense. There is little evidence that FDI served to speed up income convergence across countries. This was the case for two reasons. First, FDI flows remained highly concentrated. Second, the benefits from FDI appear to have accrued principally where conditions were already conducive to investment and growth. Hence, though cross-country disciplines through bilateral, regional and multilateral efforts are important in reducing the distortions that lead to misallocation of capital, domestic efforts to raise absorptive capacity will ultimately be critical. Efforts to increase labour mobility, as foreseen, for example, under GATS, could have a significant effect in raising the benefits from FDI as the more mobile labour serves to bridge the cultural, institutional and contractual differences across nations.
A synthesis of (R)-mevalonolactone

Abstract An enantioselective synthesis of (R)-mevalonolactone (1) has been accomplished starting from known epoxide 2, prepared with ⪢95% ee by asymmetric epoxidation of nerol. Functional group manipulation of 2 and ozonolysis afforded intermediate 8, which was converted to 11 via phenylselenoxide formation, followed by appropriate oxidations and deprotection, to afford 1.
Testing monotone high-dimensional distributions

A monotone distribution P over a (partially) ordered domain has P(y) ≥ P(x) if y ≥ x in the order. We study several natural problems of testing properties of monotone distributions over the n-dimensional Boolean cube, given access to random draws from the distribution being tested. We give a poly(n)-time algorithm for testing whether a monotone distribution is equivalent to or e-far (in the L1 norm) from the uniform distribution. A key ingredient of the algorithm is a generalization of a known isoperimetric inequality for the Boolean cube. We also introduce a method for proving lower bounds on testing monotone distributions over the n-dimensional Boolean cube, based on a new decomposition technique for monotone distributions. We use this method to show that our uniformity testing algorithm is optimal up to polylog(n) factors, and also to give exponential lower bounds on the complexity of several other problems (testing whether a monotone distribution is identical to or e-far from a fixed known monotone product distribution and approximating the entropy of an unknown monotone distribution). © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2009 A preliminary version of this work appeared in the 2005 ACM Symposium on Theory of Computing (STOC) (see 12). Any opinions, findings, and conclusions or recommendations expressed in this article are those of the authors and do not necessarily reflect the views of the National Science Foundation.
The gomberg-bachmann reaction of purines

The reaction of adenine derivatives with isoamyl nitrite in anisole solution was re-investigated. The arylated products are a mixture of ortho, meta, and para-methoxyphenyl isomers with the ortho predominating. It is concluded that this is a typical free-radical arylation and that the 6-purinyl radical is a normal, well behaved aromatic radical.
Agglomeration and job matching among college graduates

Abstract We examine job matching as a potential source of urban agglomeration economies. Focusing on college graduates, we construct two direct measures of job matching based on how well an individual's job corresponds to their college education. Consistent with matching-based theories of urban agglomeration, we find evidence that larger and thicker local labor markets increase both the likelihood and quality of a job match for college graduates. We then assess the extent to which better job matching of college-educated workers increases individual-level wages and thereby contributes to the urban wage premium. We find that college graduates with better job matches do indeed earn higher wages on average, though the contribution of such job matching to aggregate urban productivity appears to be relatively modest.