cssi/SciSciGPT-SciSciNet huggingface dataset:
Pituitary self-priming actions of gonadotropin-releasing hormone: Kinetics of estradiol’s potentiating effects on gonadotropin-releasing hormone-facilitated luteinizing hormone and follicle-stimulating hormone release in healthy postmenopausal women

Abstract We examined the kinetically distinct characteristics of estradiol's effects upon pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release in response to pulses of exogenous gonadotropin-releasing hormone (GnRH) in healthy postmenopausal individuals. The putative self-priming actions of GnRH on LH and FSH release were tested by intravenous injections of equal paired doses of GnRH (10 micrograms) before and after 1, 5, 10, and 30 d of pure estradiol-17 beta delivery via an intravaginal silastic ring. Self-priming actions of GnRH, as defined by heightened gonadotropin release in response to the second pulse of GnRH compared with the first, were completely absent in the hypoestrogenemic state. However, estradiol administration unmasked GnRH self-priming in a time-dependent fashion, with maximal expression after 5 and 10 d of steroid replacement, followed by attenuation by 30 d. Since estradiol's modulation of GnRH action was expressed differentially on LH and FSH release, we suggest that such facilitation of GnRH-stimulated pituitary LH and FSH release may provide an additional mechanism for dissociated secretion of gonadotropic hormones in health or disease.
Numerical Simulation of the Actuation System for the ALDF's Propulsion Control Valve

A numerical simulation of the actuation system for the propulsion control valve (PCV) of the NASA Langley Aircraft Landing Dynamics Facility was developed during the preliminary design of the PCV and used throughout the entire project. The simulation is based on a predictive model of the PCV which is used to evaluate and design the actuation system. The PCV controls a 1.7 million-pound thrust water jet used in propelling a 108,000-pound test carriage. The PCV can open and close in 0.300 second and deliver over 9,000 gallons of water per sec at pressures up to 3150 psi. The numerical simulation results are used to predict transient performance and valve opening characteristics, specify the hydraulic control system, define transient loadings on components, and evaluate failure modes. The mathematical model used for numerically simulating the mechanical fluid power system is described, and numerical results are demonstrated for a typical opening and closing cycle of the PCV. A summary is then given on how the model is used in the design process.
Synthesis, Symmetry and Physical Properties of Cerium Pyrophosphate

CeP2O7, a close structural relative of ZrP2O7, and many other MIVX2O7 (X – P, V, As) phases, forms on heating Ce(HPO4)2·xH2O between ∼300 and 600 °C and decomposes by oxygen loss at higher temperatures. In-situ X-ray diffraction measurements showed, for some precursor batches, the formation of CeP2O7 in two distinct stages. At room temperature, CeP2O7 is pseudocubic, but probably triclinic, displaying positive thermal expansion below ∼115 °C. Above this temperature, there is a transition to cubic symmetry (Pa3) with the linear coefficient of thermal expansion going to zero at ∼450 °C and becoming negative at higher temperatures. CeP2O7 probably undergoes two phase transitions on compression below ∼10.5 GPa. The phase existing between 0.65 and ∼5 GPa is soft with an average bulk modulus of ∼18 GPa.
Fully radiative electroweak symmetry breaking

Models of Gauge-Higgs unification in extra dimensions offer a very elegant playground where one can study electroweak symmetry breaking. The Higgs potential is fully radiatively generated and the contribution of bulk fermions will induce a vacuum expectation value. A generic problem is that the quartic scalar coupling is too low, resulting in a Higgs VEV that is too close to the compactification scale, and a Higgs mass that is too light. In this paper we show that it is possible to solve these problems in a minimal scenario in flat space by cancellations in the Higgs potential between the contribution of different bulk fermions. A crucial role is played by antiperiodic fermions: the cancellation is not the result of a fine tuning, but rather dictated by the choice of representations and parities of the fermions. We also show that introducing a relatively large representation can help in achieving a sufficiently heavy top. In this case, the strong coupling scale is lowered to a marginally acceptable value, and a more careful analysis of two loop effects should decide if the theory remains under perturbative control.
Low-Mass X-Ray Binaries and Globular Clusters in Early-Type Galaxies. I. Chandra Observations

We present a Chandra survey of LMXBs in 24 early-type galaxies. Correcting for detection incompleteness, the X-ray luminosity function (XLF) of each galaxy is consistent with a power law with negative logarithmic differential slope, β ~ 2.0. However, β strongly correlates with incompleteness, indicating the XLF flattens at low-LX. The composite XLF is well fitted by a power law with a break at (2.21+ 0.65−0.56) × 1038 ergs s−1 and β = 1.40+ 0.10−0.13 and 2.84+ 0.39−0.30 below and above it, respectively. The break is close to the Eddington limit for a 1.4 M☉ neutron star, but the XLF shape rules out its representing the division between neutron star and black hole systems. Although the XLFs are similar, we find evidence of some variation between galaxies. The high-LX XLF slope does not correlate with age, but may correlate with [α/Fe]. Considering only LMXBs with LX > 1037 ergs s−1, matching the LMXBs with globular clusters (GCs) identified in HST observations of 19 of the galaxies, we find the probability a GC hosts an LMXB is proportional to LαGCZγFe where α = 1.01 ± 0.19 and γ = 0.33 ± 0.11. Correcting for GC luminosity and color effects, and detection incompleteness, we find no evidence that the fraction of LMXBs with LX > 1037 ergs s−1 in GCs (40%), or the fraction of GCs hosting LMXBs (~6.5%) varies between galaxies. The spatial distribution of LMXBs resembles that of GCs, and the specific frequency of LMXBs is proportional to the GC specific luminosity, consistent with the hypothesis that all LMXBs form in GCs. If the LMXB lifetime is τL and the duty cycle is Fd, our results imply ~1.5(τL/108 yr )−1F−1d LMXBs are formed per gigayear per GC, and we place an upper limit of one active LMXB in the field per 3.4 × 109 L☉ of V-band luminosity.
Single-photon diode by exploiting the photon polarization in a waveguide

By exploiting unique polarizations in nano-photonic waveguides, a single-photon diode is implemented by coupling a quantum dot to the waveguide which possesses a locally planar, circular polarization. The contrast is >0.9, allowing practical applications.
Secondary instability mechanisms in compressible axisymmetric boundary layers

Secondary instability mechanisms in compressible, axisymmetric boundary layers are analyzed using spectrally-accurate mean-flow and stability codes. Results show that subharmonic disturbances are the most dangerous secondary disturbances in an environment with a low to moderate intensity of the primary disturbance. The relation between spatial and temporal analyses of the secondary disturbance is explored at Mach 1.6 along a flat plate and Mach 6.8 along a cone. Spatial direct numerical simulations are utilized to confirm the quantitative predictions from spatial secondary instability theory.
Aircraft terrain following based on a nonlinear continuous predictive control approach

This paper discusses aircraft terrain-following flight control law development based on a new nonlinear optimal predictive control method. The control law minimizes the predicted difference between the actual trajectory and a smooth open-loop reference trajectory that satisfies the aircraft dynamic model. A fixed-point algorithm is used to compute sequentially the tracking control commands from the implicit control law. Globally asymptotically stable tracking of the reference trajectory is proved in the absence of control saturation, and the influences of the controller parameters on the tracking dynamics are identified. Numerical simulations are presented for a supersonic fighter aircraft model over a standard test terrain. These simulations include the effects of initial condition errors, aerodynamic modeling inaccuracies, and vertical wind disturbances.
Mechanisms that enforce bounds on packet lifetimes

For reliable transport protocol operation the lifetime of packets should not exceed an assumed maximum packet lifetime (MPL). A packet's lifetime is spent in nodes and crossing links. Time spent in nodes and on simple links is easily found. Other links or logical links may lose, duplicate, delay, and reorder data and do not provide transittime information. We present a link-transit-time protocol for bounding the transit time of packets that cross such links.
Study of nucleon resonances with electromagnetic interactions

Recent developments in using electromagnetic meson production reactions to study the structure of nucleon resonances are reviewed. Possible future works are discussed.
Heat Transfer Analysis of Nuclear Waste Casks Stored in the Yucca Mountain Repository

A numerical model of the residual heat associated with stored nuclear waste casks proposed for long-term storage in Yucca Mountain has been developed. The Yucca Mountain Repository, located about 100 miles from Las Vegas, NV, is the proposed long-term geologic repository for high-level nuclear waste. STAR-CD, one of several commercial computational fluid dynamics packages being used for the assessment studies, was used to establish the numerical model. The model was developed to simulate the fluid flow and heat transfer within the drift tunnels generated by the waste casks over a 10,000-year time cycle. The model shows that the heat generated from within the casks is partially removed by ventilating air moving through the drifts and conduction through the drift walls. Thermal radiation was found to have little effect on overall cooling compared to the roles of natural convection adjacent to the casks and forced convection from the drift ventilation.
Allan Cox 1926”1987

More than 1000 friends, students, and colleagues from all over the country filled Stanford Memorial Chapel (Stanford, Calif.) on February 3, 1987, to join in “A Celebration of the Life of Allan Cox.” Allan died early on the morning of January 27 while bicycling, the sport he had come to love the most. Between pieces of his favorite music by Bach and Mozart, Stanford administrators and colleagues spoke in tribute of Allan's unique qualities as friend, scientist, teacher, and dean of the School of Earth Sciences. James Rosse, Vice President and Provost of Stanford University, struck a particularly resonant chord with his personal remarks: "Allan reached out to each person he knew with the warmth and attention that can only come from deep respect and affection for others. I never heard him speak ill of others, and I do not believe he was capable of doing anything that would harm another being. He cared too much to intrude where he was not wanted, but his curiosity about people and the loving care with which he approached them broke down reserve to create remarkable friendships. His enthusiasm and good humor made him a welcome guest in the hearts of the hundreds of students and colleagues who shared the opportunity of knowing Allan Cox as a person."
Room-Temperature Palladium-Catalyzed Amination of Aryl Bromides and Chlorides and Extended Scope of Aromatic C−N Bond Formation with a Commercial Ligand

The reactions of aryl bromides with amines occurs at room temperature when using Pd(0) and P(t-Bu)(3) in a 1:1 ratio, and the reactions of aryl chlorides occur at room temperature or 70 degrees C. The arylation of indoles and the new arylation of carbamates also occur when using P(t-Bu)(3) as ligand.
Formation of dwarf galaxies and small-scale problems of CDM

The concordance cosmological model based on cold dark matter makes definitive predictions for the growth of galaxies in the Universe, which are being actively studied using numerical simulations. These predictions appear to contradict the observations of dwarf galaxies. Dwarf dark matter halos are more numerous and have steeper central density profiles than the observed galaxies. The first of these small-scale problems, the “missing satellites problem”, can be resolved by accounting for the low efficiency of gas cooling and star formation in dwarf halos. A newly-discovered class of HyperVelocity Stars will soon allow us to test another generic prediction of CDM models, the triaxial shapes of dark matter halos. Measuring the proper motions of HVS will probe the gravitational potential out to 100 kpc and will constrain the axis ratios and the orientation of the Galactic halo.
Introduction to A Theory of the Allocation of Time by Gary Becker

Gary Becker's classic study, ‘A theory of the allocation of time’, laid the analytical foundations for the study of household production and the allocation of time within the household. It spawned a large literature and continues to influence economics and other social sciences. The article was written when Becker was in his mid-30s, teaching at Columbia University and conducting research at the National Bureau of Economic Research, then headquartered in New York. Over the period 1958–69, Becker, along with Jacob Mincer, organised the legendary Columbia Labour Economics Workshop. Becker, Mincer and their students applied price theory to study the economics of fertility, labour supply, income inequality, education, on-the-job training, crime and punishment and the theory of irrational behaviour, among other topics. The interplay between theory and data was the hallmark of that group. From this crucible emerged the modern theory of human capital (Becker, ,) and important components of the modern economics of the family that were distilled and extended in Becker's classic A Treatise on the Family (1981, enlarged in 1991). A generation of productive and influential scholars was trained at Columbia during this period (Heckman, 2014). In his introduction to this article, Becker discusses the body of research on the economics of time that was being conducted at Columbia, to which he contributed and from which he had drawn. This article is the analytical synthesis of a body of ideas developed in that intense intellectual climate. Many scholars have tried to disentangle the contributions of Jacob Mincer from those of Gary Becker during the period of their synergistic collaboration. Attempts to do so miss the highly interactive and mutually supportive intellectual environment of the Columbia group and the ability of Becker to create clean analytical insights from diverse bodies of empirical work and to stimulate all those around him.
Propagation of variances in belief networks

The belief network is a well-known graphical structure for representing independencies in a joint probability distribution. The methods, which perform probabilistic inference in belief networks, often treat the conditional probabilities which are stored in the network as certain values. However, if one takes either a subjectivistic or a limiting frequency approach to probability, one can never be certain of probability values. An algorithm should not only be capable of reporting the probabilities of the outcomes of remaining nodes when other nodes are instantiated; it should also be capable of reporting the uncertainty in these probabilities relative to the uncertainty in the probabilities which are stored in the network. In this paper a method for determining the variances in inferred probabilities is obtained under the assumption that a posterior distribution ont eh uncertainty variables can be approximated by the prior distribution. It is shown that this assumption is plausible if their is a reasonable amount of confidence in the probabilities which are stored in the network.
Determinant computations for some classes of Toeplitz-Hankel matrices

The purpose of this paper is to compute the asymptotics of determinants of finite sections of operators that are trace class perturbations of Toeplitz operators. For example, we consider the asymptotics in the case where the matrices are of the form (ai−j ± ai+j+1−k)i,j=0...N−1 with k is fixed. We will show that this example as well as some general classes of operators have expansions that are similar to those that appear in the Strong Szego Limit Theorem. We also obtain exact identitities for some of the determinants that are analogous to the one derived independently by Geronimo and Case and by Borodin and Okounkov for finite Toeplitz matrices. These problems were motivated by considering certain statistical quantities that appear in random matrix theory.
Stability of thermal convection in a vertical porous layer

Experiments were carried out to study the stability of thermal convection generated in a vertical porous layer by lateral heating in a tall, narrow tank. The porous medium, consisting of glass beads, was saturated with distilled water. It was found that the flow became unstable at a critical {Delta}T of 29.2C (critical Rayleigh number of 66.2). Linear stability analysis was applied to study the effects of the Brinkman term and of variable viscosity separately using a quadratic relationship between the density and temperature. It was found that with the Brinkman term, no instability could occur within the allowable temperature difference across the tank. With the effect of variable viscosity included, linear stability theory predicts a critical {Delta}T of 43.4C (Rayleigh number of 98.3).
Solar-Reflectance-Based Calibration of Spectral Radiometers

[1] A method by which to calibrate a spectral radiometer using the sun as the illumination source is discussed. The procedure is simple, requiring only a calibrated reflectance panel, relatively low aerosol optical depth, and accurate measurements of atmospheric transmittance. Solar-based calibrations eliminate several uncertainties associated with applying a lamp-based calibration to field measurements and may be performed with a comparable uncertainty. A solar-reflectance-based calibration (SRBC), by removing the need for extraterrestrial irradiance spectra, further reduces calibration uncertainty to approximately 2.2%. This calibration may be applied to radiometric measurements of any system illuminated by the sun, such as the atmosphere or ocean, with associated reduction of uncertainty in properties derived from such measurements (e.g., aerosol single_scattering albedo). The procedure is ideal for on_site calibration of long_term field instruments, mitigating the logistics and costs associated with transport to a calibration facility.
Arma models for earthquake ground motions

This paper outlines the use of discrete, autoregressive/moving-average (ARMA) models for identification and estimation of parameters in models derived from analysis of uniformly digitized earthquake ground motion acceleration data. Such models are of equal generality as compared to continuous-time models and have a number of significant advantages for purposes of digital analysis and simulation. The structure of ARMA models is briefly described, their relation to continuous models noted, and results of their application to a number of recorded accelerograms summarized.
DEFINING AN SU(3)-CASSON/U(2)-SEIBERG–WITTEN INTEGER INVARIANT FOR INTEGRAL HOMOLOGY 3-SPHERES

An open question is the possibility of defining an integer valued SU(3)-Casson invariant for integral homology 3-spheres which involves counting the irreducible portion of the non-degenerate (perturbed) moduli space of flat SU(3)-connections plus counter-terms associated to only the non-degenerate (perturbed) reducible portion of the moduli space. The obstruction to this is the non-trivial spectral flow of a family of twisted signature operators in 3-dimensions. The parallel U(2)-Seiberg–Witten theory also has a similiar obstruction but arising from the non-trivial spectral flow of a family of twisted Dirac operators. By taking the SU(3)-flat and U(2)-Seiberg–Witten equations simultaneously the obstructions can be made to cancel and an integer invariant is obtained.
Detection of new and persistent Streptococcus uberis and Streptococcus dysgalactiae intramammary infections by polymerase chain reaction-based DNA fingerprinting

Polymerase chain reaction-based DNA fingerprinting was used as a tool to differentiate new and persistent Streptococcus uberis and Streptococcus dysgalactiae intramammary infections (IMI) in dairy cows. The same subtype of S. uberis or S. dysgalactiae was detected from some infected mammary glands from one lactation to the next documenting the persistence of these infections. Conversely, some streptococci isolated from mammary glands during a lactation or from one lactation to the next were different subtypes suggesting that a new IMI occurred. These new streptococcal IMI would never have been detected using phenotypic methods of streptococcal identification. Results of this study indicate that PCR-based DNA fingerprinting can be used as an effective procedure to differentiate new and persistent S. uberis and S. dysgalactiae IMI in dairy cows. This technique will be useful in epidemiological investigations, and drug and vaccine efficacy studies when attempting to delineate new and persistent IMI.
Status and problems of semiconductor detectors

Abstract A brief review is given of the types of silicon and germanium detectors used or presently being developed for nuclear experiments. Large-area silicon and germanium detector telescopes for use in long-range particle detection and identification are emphasized. Large area position-sensitive detectors are also described. Some results are presented regarding radiation damage and damage repair by annealing. Evidence is also presented for the importance of producing large area silicon crystals of adequate quality to reduce trapping problems to negligible proportions.
Were British cotton entrepreneurs technologically backward? Firm-level evidence on the adoption of ring spinning

I study the slow adoption of ring-spinning in Great Britain's cotton industry at the end of the 19th century, which has been used as evidence of British entrepreneurs' declining efficiency and conservatism (Musson [1959], Aldcroft, [1964], Lazonick [1981, 1981b]). To this purpose I use firm-level data from all of Lancashire's cotton firms over several years. The data are from the Worrall's Cotton Spinners' and Manufacturers' Directories for the years 1885, 1886-1887, 1890, 1894, 1902, and 1910. First, I show that the vertical organization of the industry, with its firms specializing in spinning or weaving, did not act as an impediment to the adoption of the ring-spinning technology, as was argued by Lazonick. In particular, I show the following: i) non-integrated firms were the first to adopt rings in Great Britain; ii) the large majority of firms that adopted rings were incumbents; iii) vertically integrated firms that were spinning only either twist or weft yarn were still in existence in 1910; and iv) only a negligible number of firms changed their organizational structure upon adopting ring spinning. I also show that a large fraction of firms installed very small numbers of ring spindles upon the adoption of ring spinning, suggesting that firms were slowly adopting ring spindles to replace old mule spindles rather than transitioning over to ring spinning at a single point in time. Then, I show that the rate at which vertically integrated firms adopted rings suddenly accelerated after 1902. I interpret this as evidence that British entrepreneurs were fully aware of the technological complementarities between rings and automatic looms. These complementarities could only be fully exploited by vertically integrated firms.
Solubility of refractory oxides in soda-lime glass

A method for measuring the solubility limit of refractory oxides in glass is presented, and the solubilities of Al2O3, ZrO2, SnO2, and Cr2O3 in soda-lime glass are given as a function of temperature. The order of solubility in soda-lime glass is Al2O3ZrO2SnO2Cr2O3 at 1300° to 16Q0°C. The solubility of ZrO2 in Al2O3-saturated soda-lime glass is much lower than that in pure soda-lime glass.
Information-theoretic inequalities on unimodular Lie groups

Classical inequalities used in information theory such as those of de Bruijn, Fisher, Cramer, Rao, and Kullback carry over in a natural way from Euclidean space to unimodular Lie groups. These are groups that possess an integration measure that is simultaneously invariant under left and right shifts. All commutative groups are unimodular. And even in noncommutative cases unimodular Lie groups share many of the useful features of Euclidean space. The rotation and Euclidean motion groups, which are perhaps the most relevant Lie groups to problems in geometric mechanics, are unimodular, as are the unitary groups that play important roles in quantum computing. The extension of core information theoretic inequalities defined in the setting of Euclidean space to this broad class of Lie groups is potentially relevant to a number of problems relating to information gathering in mobile robotics, satellite attitude control, tomographic image reconstruction, biomolecular structure determination, and quantum information theory. In this paper, several definitions are extended from the Euclidean setting to that of Lie groups (including entropy and the Fisher information matrix), and inequalities analogous to those in classical information theory are derived and stated in the form of fifteen small theorems. In all such inequalities, addition of random variables is replaced with the group product, and the appropriate generalization of convolution of probability densities is employed. An example from the field of robotics demonstrates how several of these results can be applied to quantify the amount of information gained by pooling different sensory inputs.
Dispersed excess demands, the weak axiom and uniqueness of equilibrium

Abstract This paper introduces an economically interpretable hypothesis that implies that mean excess demand satisfies the weak axiom and that competitive equilibrium is unique. The hypothesis requires, roughly, that the consumers' excess demand vectors spread apart on average as their wealth increases. The hypothesis is potentially testable using cross-section data on consumer expenditures and endowments. It is satisfied in a robust class of economies, including those with suitable types of consumer heterogeneity. However, it implies stringent restrictions on the consumers' Engel curves if it is required to hold for every distribution of collinear consumer endowments.
1,2-Asymmetric induction in radical reactions. Deuteration and allylation reactions of β-oxy-o-Iodoanilides.

Abstract Chiral radicals were generated by radical translocation reactions of β-oxy-o-iodoanilides and their asymmetric deuteration and allylation reactions were studied.
Torsionally Constrained DNA for Single-Molecule Assays: An Efficient, Ligation-Free Method

Controlled twisting of individual, double-stranded DNA molecules provides a unique method to investigate the enzymes that alter DNA topology. Such twisting requires a single DNA molecule to be torsionally constrained. This constraint is achieved by anchoring the opposite ends of the DNA to two separate surfaces via multiple bonds. The traditional protocol for making such DNA involves a three-way ligation followed by gel purification, a laborious process that often leads to low yield both in the amount of DNA and the fraction of molecules that is torsionally constrained. We developed a simple, ligation-free procedure for making torsionally constrained DNA via polymerase chain reaction (PCR). This PCR protocol used two “megaprimers,” 400-base-pair long double-stranded DNA that were labelled with either biotin or digoxigenin. We obtained a relatively high yield of gel-purified DNA (∼500 ng per 100-µl PCR reaction). The final construct in this PCR-based method contains only one labelled strand in contrast to the traditional construct in which both strands of the DNA are labelled. Nonetheless, we achieved a high yield (84%) of torsionally constrained DNA when measured using an optical-trap-based DNA-overstretching assay. This protocol significantly simplifies the application and adoption of torsionally constrained assays to a wide range of single-molecule systems.
HEADACHES AND ANISEIKONIA

SUMMARY AND CONCLUSION It has been recognised that headaches are a symptom, not a disease, and while this may be a consolation to the doctor, it is not to the patient, who feels that the “symptom” is as uncomfortable as if it were a “disease.” Furthermore, while it is freely admitted in the literature on headaches that ocular anomalies are the cause of many headaches, nevertheless there are also many other causes. The recognition that ocular anomalies are the cause of some headaches includes, usually, the well-known pathological conditions of the eyes; the ametropic errors and the abnormalities of the muscle balance and fusion faculty, but does not include the recently investigated anomaly of binocular vision known as aniseikonia. Statistics and a sampling of individual case reports show that the condition of aniseikonia deserves to be considered in the etiology and therapeutics of patients who complain of headaches.
Reverse engineering module networks by PSO-RNN hybrid modeling.

Background Inferring a gene regulatory network (GRN) from high throughput biological data is often an under-determined problem and is a challenging task due to the following reasons: (1) thousands of genes are involved in one living cell; (2) complex dynamic and nonlinear relationships exist among genes; (3) a substantial amount of noise is involved in the data, and (4) the typical small sample size is very small compared to the number of genes. We hypothesize we can enhance our understanding of gene interactions in important biological processes (differentiation, cell cycle, and development, etc) and improve the inference accuracy of a GRN by (1) incorporating prior biological knowledge into the inference scheme, (2) integrating multiple biological data sources, and (3) decomposing the inference problem into smaller network modules.
Room Temperature Copper(II)-Catalyzed Oxidative Cyclization of Enamides to 2,5-Disubstituted Oxazoles via Vinylic C–H Functionalization

A copper(II)-catalyzed oxidative cyclization of enamides to oxazoles via vinylic C–H bond functionalization at room temperature is described. Various 2,5-disubstituted oxazoles bearing aryl, vinyl, alkyl, and heteroaryl substituents could be synthesized in moderate to high yields. This reaction protocol is complementary to our previously reported iodine-mediated cyclization of enamides to afford 2,4,5-trisubstituted oxazoles.
Mesoscopic tunneling magnetoresistance

We study spin-dependent transport through ferromagnet/normal-metal/ferromagnet double tunnel junctions in the mesoscopic Coulomb-blockade regime. We calculate the conductance in the absence or presence of spin-orbit interaction and for arbitrary orientation of the lead magnetizations. The tunneling magnetoresistance (TMR), defined at the Coulomb-blockade conductance peaks, is calculated and its probability distribution presented. We show that mesoscopic fluctuations can lead to the optimal value of the TMR and that the conductance in noncollinear configurations gives information about how the spin rotates inside the grain.
The long-run relationship between inflation and real stock prices

Abstract In this paper, we use recent developments in the testing of long-run neutrality propositions to measure the long-run response of real stock prices to a permanent inflation shock for 16 individual industrialized countries. The estimation results provide considerable support for long-run inflation neutrality with respect to real stock prices. Ranges of plausible identifying parameter values are also consistent with a positive long-run real stock price response to a permanent inflation shock. There is little plausible evidence for a negative long-run real stock price response to a permanent inflation shock. Overall, our results indicate that inflation does not erode the long-run real value of stocks.
On the norm closure problem for complex symmetric operators

We prove that the set of all complex symmetric operators on a separable, infinite-dimensional Hilbert space is not norm closed.
Foil x-ray mirrors for astronomical observations: still an evolving technology

Foil X-ray mirrors, introduced by the Goddard X-ray Group in the late 1970s, were envisioned as an interim and complementary approach toward increased sensitivity for small inexpensive astronomical instruments. The extreme light weight nature of these mirrors dovetailed beautifully with Japan's small payload missions, leading to several collaborative, earth orbiting observatories, designed primarily for spectroscopy, of which SUZAKU is still in earth orbit. ASTRO-H is the latest joint instrument with Japan, presently in the implementation phase. At Goddard, some 30 years after we introduced them, we are involved with four separate flight instruments utilizing foil X-ray mirrors, a good indication that this technology is here to stay. Nevertheless, an improved spatial resolution will be the most welcomed development by all. The task of preparing upwards of 1000 reflectors, then assembling them into a single mirror with arcmin resolution remains a formidable one. Many, performance limiting approximations become necessary when converting commercial aluminum sheets into 8 quadrant segments, each with ~200 nested conical, ~4A surface reflectors, which are then assembled into a single mirror. In this paper we will dscribe the mirror we are presently involved with, slated for the Goddard high resolution imaging X-ray spectrometer (SXS) onboard ASTRO-H. Improved spatial resolution will be an important enhancement to the science objectives from this instrument. We are accordingly pursuing and will briefly describe in this paper several design and reflector assembly modifications, aimed toward that goal.
Multidisciplinary cognitive content of nanoscience and nanotechnology

This article examines the cognitive evolution and disciplinary diversity of nanoscience/nanotechnology (nano research) as expressed through the terminology used in titles of nano journal articles. The analysis is based on the NanoBank bibliographic database of 287,106 nano articles published between 1981 and 2004. We perform multifaceted analyses of title words, focusing on 100 most frequent words or phrases (terms). Hierarchical clustering of title terms reveals three distinct time periods of cognitive development of nano research: formative (1981–1990), early (from 1991 to 1998), and current (after 1998). Early period is characterized by the introduction of thin film deposition techniques, while the current period is characterized by the increased focus on carbon nanotube and nanoparticle research. We introduce a method to identify disciplinary components of nanotechnology. It shows that the nano research is being carried out in a number of diverse parent disciplines. Currently, only 5% of articles are published in dedicated nano-only journals. We find that some 85% of nano research today is multidisciplinary. The case study of the diffusion of several nano-specific terms (e.g., “carbon nanotube”) shows that concepts spread from the initially few disciplinary components to the majority of them in a time span of around a decade. Hierarchical clustering of disciplinary components reveals that the cognitive content of current nanoscience can be divided into nine clusters. Some clusters account for a large fraction of nano research and are identified with such parent disciplines as the condensed matter and applied physics, materials science, and analytical chemistry. Other clusters represent much smaller parts of nano research, but are as cognitively distinct. In the decreasing order of size, these fields are: polymer science, biotechnology, general chemistry, surface science, and pharmacology. Cognitive content of research published in nano-only journals is the closest to nano research published in condensed matter and applied physics journals.
Chiral Koszul Duality

We extend the theory of chiral and factorization algebras, developed for curves by Beilinson and Drinfeld (American Mathematical Society Colloquium Publications, 51. American Mathematical Society, Providence, RI, 2004), to higher-dimensional varieties. This extension entails the development of the homotopy theory of chiral and factorization structures, in a sense analogous to Quillen’s homotopy theory of differential graded Lie algebras. We prove the equivalence of higher-dimensional chiral and factorization algebras by embedding factorization algebras into a larger category of chiral commutative coalgebras, then realizing this interrelation as a chiral form of Koszul duality. We apply these techniques to rederive some fundamental results of Beilinson and Drinfeld (American Mathematical Society Colloquium Publications, 51. American Mathematical Society, Providence, RI, 2004) on chiral enveloping algebras of \({\star}\) -Lie algebras.
Contract enforcement in the early transition of an unstable economy

Abstract How were contracts among firms enforced in the early phase of a transition economy when firms lacked experience with commercial contracts or legal procedures? What were their views of their new business environment? We interviewed a sample of Bulgarian firms, including private, state-owned and cooperative firms in 1994. Consistent with Williamson's [Williamson, O., 1994. Institutions of economic development and reform. In: Bruno, M., Pleskovic, B. (Eds.), Proceedings of the World Bank Annual Bank Conference on Development Economics, World Bank, Washington, DC, pp. 171–197] theories, complex contracts were quite limited, sometimes implying the breakdown of important markets, but we also found that even spot-market contracts had severe problems of bilateral dependency. Having been “burned” in previous transactions, firms were very cautious in dealing with new potential trading partners and tried to work closely with trustworthy counterparts. These results are consistent with Klein et al. [Klein, B., Crawford, R., Alchian, A., 1978. Vertical integration, appropriable rents, and the competitive contracting process. J. Law Econ. 21, 297–326] theory.
On the sum of superoptimal singular values

In this paper, we study the following extremal problem and its relevance to the sum of the so-called superoptimal singular values of a matrix function: Given an m×n matrix function Φ, when is there a matrix function Ψ∗ in the set Akn,m such that ∫Ttrace(Φ(ζ)Ψ∗(ζ))dm(ζ)=supΨ∈Akn,m|∫Ttrace(Φ(ζ)Ψ(ζ))dm(ζ)|? The set Akn,m is defined by Akn,m=def{Ψ∈H01(Mn,m):‖Ψ‖L1(Mn,m)⩽1,rankΨ(ζ)⩽k a.e. ζ∈T}. To address this extremal problem, we introduce Hankel-type operators on spaces of matrix functions and prove that this problem has a solution if and only if the corresponding Hankel-type operator has a maximizing vector. The main result of this paper is a characterization of the smallest number k for which ∫Ttrace(Φ(ζ)Ψ(ζ))dm(ζ) equals the sum of all the superoptimal singular values of an admissible matrix function Φ (e.g. a continuous matrix function) for some function Ψ∈Akn,m. Moreover, we provide a representation of any such function Ψ when Φ is an admissible very badly approximable unitary-valued n×n matrix function.
Mixings, lifetimes, spectroscopy and production of heavy flavor at the Tevatron

The Fermilab Tevatron offers unique opportunities to perform measurements of the heavier B hadrons that are not accessible at the ϒ(4S) resonance. In this summary, we describe some recent heavy flavor results from the DO and CDF collaborations and discuss prospects for future measurements.
Discovery of the silver isotopes

Thirty-eight silver isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.
Wigner crystal physics in quantum wires.

The physics of interacting quantum wires has attracted a lot of attention recently. When the density of electrons in the wire is very low, the strong repulsion between electrons leads to the formation of a Wigner crystal. We review the rich spin and orbital properties of the Wigner crystal, in both the one-dimensional and the quasi-one-dimensional regimes. In the one-dimensional Wigner crystal the electron spins form an antiferromagnetic Heisenberg chain with exponentially small exchange coupling. In the presence of leads, the resulting inhomogeneity of the electron density causes a violation of spin–charge separation. As a consequence the spin degrees of freedom affect the conductance of the wire. Upon increasing the electron density, the Wigner crystal starts deviating from the strictly one-dimensional geometry, forming a zigzag structure instead. Spin interactions in this regime are dominated by ring exchanges, and the phase diagram of the resulting zigzag spin chain has a number of unpolarized phases as well as regions of complete and partial spin polarization. Finally we address the orbital properties in the vicinity of the transition from a one-dimensional to a quasi-one-dimensional state. Due to the locking between chains in the zigzag Wigner crystal, only one gapless mode exists. Manifestations of Wigner crystal physics at weak interactions are explored by studying the fate of the additional gapped low-energy mode as a function of interaction strength.
Lagrangian Subcategories and Braided Tensor Equivalences of Twisted Quantum Doubles of Finite Groups

We classify Lagrangian subcategories of the representation category of a twisted quantum double D ω (G), where G is a finite group and ω is a 3-cocycle on it. In view of results of [DGNO] this gives a complete description of all braided tensor equivalent pairs of twisted quantum doubles of finite groups. We also establish a canonical bijection between Lagrangian subcategories of Rep(D ω (G)) and module categories over the category $${\rm Vec}_{G} ^{\omega}$$ of twisted G-graded vector spaces such that the dual tensor category is pointed. This can be viewed as a quantum version of V. Drinfeld’s characterization of homogeneous spaces of a Poisson-Lie group in terms of Lagrangian subalgebras of the double of its Lie bialgebra [D]. As a consequence, we obtain that two group-theoretical fusion categories are weakly Morita equivalent if and only if their centers are equivalent as braided tensor categories.
Drag Prediction of Engine-Airframe Interference Effects with CFX-5

The commercial computational fluid dynamics (CFD) code CFX-5 of ANSYS, Inc., has been used to compute the engine installation drag for the German Aerospace Center (DLR) F6 aircraft configuration as part of the Second AIAA Drag Prediction Workshop. The computations were performed with the standard hexahedral meshes provided by ICEM.CFD to the workshop. The full drag polar for the DLR-F6 configuration has been computed. For all cases, good agreement between the experiment and the predictions were obtained for lift, drag, and pitching moment coefficients. All simulations where based on the shear stress transport turbulence model, and additional computations have indicated that turbulence modeling issues are largely responsible for the overprediction of the lift curve slope that was observed by many of the workshop participants.
An adaptive actuator failure compensation scheme for a cooperative manipulator system

This paper develops a new adaptive actuator failure compensation algorithm for the control of a cooperative robotic system subject to uncertain actuator failures. The benchmark robotic system has two manipulators to balance a rigid platform, and the right-side manipulator contains one actuator and the left-side manipulator has two actuators (one of which may fail during system operation, but it is uncertain how much, when and which actuator may fail). The developed adaptive actuator failure compensation scheme, based on adaptive integration of three individual failure compensators and direct adaptation of controller parameters, is capable of ensuring desired closed-loop stability and asymptotic output tracking, despite the failure uncertainties. Such an adaptive actuator failure compensation method is extended to control of a general cooperative robotic system. Simulation results are shown to verify the desired adaptive failure compensation control performance.
Electrochemical Oxidation of Alpha Amino and Alpha Hydrazino Phosphinic Acids

Abstract In the electrochemical oxidations of phosphinic acids substituted at the alpha carbon with amine or hydrazine groups cleavage of the phosphorus-carbon bond occurred. The site of oxidation appears to be at nitrogen, even though the reactions were carried out in strongly acidic aqueous solutions.
Indestructibility and the level-by-level agreement between strong compactness and supercompactness

Can a supercompact cardinalbe Laver indestructible when there is a level-by-level agreement between strong compactness and supercompactness? In this article, we show that if there is a sufficiently large cardinal above�, then no, it cannot. Conversely, if one weakens the requirement either by demanding less indestructibility, such as requiring only indestructibility by stratified posets, or less level-by-level agreement, such as requiring it only on measure one sets, then yes, it can.
Detection and measurement of ice grains and gas distribution in the Enceladus plume by Cassini's Ion Neutral Mass Spectrometer

[1] We report on the measurements of the Cassini Ion Neutral Mass Spectrometer (INMS) of the density and structure of Enceladus' south polar plume during the E3 and E5 flybys on 12 March and 9 October 2008. Using a Monte Carlo simulation, we analyze the dependence of the INMS gas inlet transmittance on spacecraft pointing and the effect on the measurements at E3. We apply a finite element analysis to correct for water physisorption in the inlet and obtain a maximum plume density almost twice that suggested by the raw INMS data. The results indicate uniform spreading of the plume vapor from the source with a source rate of at least 100 kg/s. We also analyze the detection of ice grains by the INMS and find that, in contrast to the plume's vapor component, the grains are concentrated within the plume jets seen in Cassini imaging, supporting the suggestion that the jets are composed of fine-grained ice.
Learning from Failure

Failures may lead to ultimate success in both nature and business. Just as dynamic ecosystems depend on death to replace senescent organisms with vigorous growth, the termination of uneconomic activities is essential to wealth creation. This paper explores the benefits of failures, and uses aspects of the analogy between death and business failure to analyze how failures in business economize upon resources and lead to better firms and greater efficiencies. A distinguishing feature of our work is the analytic use of competitive markets to provide insights into the processes of success and failure. Recognizable patterns of business failures are discussed in an effort to provide entrepreneurs and managers with a basis for understanding and acting upon changing circumstances.
Numerical Prediction of Exhaust Fan-Tone Noise from High-Bypass Aircraft Engines

The ability to accurately predict fan noise is important in designing and optimizing aircraft engine turbofans for low noise emissions. In this paper, a prediction methodology for exhaust fan tone noise analysis is described and validated against various canonical test cases and NASA Source Diagnostic Test (SDT) 1,2 data. The prediction process consists of solving Reynolds-Averaged Navier-Stokes (RANS) equations to compute the fan wake, and calculating the acoustic response of the outlet guide vanes (OGV) to the fan wake using linearized Euler equations. Very good agreement is observed between numerical predictions and semi-analytical results for canonical cases. Detailed comparisons against SDT data are presented for unsteady vane pressure and integrated in-duct exhaust noise power levels. Geometric trends for dierent OGV configurations at various operating conditions are also analyzed.