cssi/SciSciGPT-SciSciNet huggingface dataset:
Preparation of (−)-Nutlin-3 Using Enantioselective Organocatalysis at Decagram Scale

Chiral nonracemic cis-4,5-bis(aryl)imidazolines have emerged as a powerful platform for the development of cancer chemotherapeutics, stimulated by the Hoffmann-La Roche discovery that Nutlin-3 can restore apoptosis in cells with wild-type p53. The lack of efficient methods for the enantioselective synthesis of cis-imidazolines, however, has limited their more general use. Our disclosure of the first enantioselective synthesis of (−)-Nutlin-3 provided a basis to prepare larger amounts of this tool used widely in cancer biology. Key to the decagram-scale synthesis described here was the discovery of a novel bis(amidine) organocatalyst that provides high enantioselectivity at warmer reaction temperature (−20 °C) and low catalyst loadings. Further refinements to the procedure led to the synthesis of (−)-Nutlin-3 in a 17 g batch and elimination of all but three chromatographic purifications.
Transient response of a packed bed for thermal energy storage

Abstract An analysis, with experimental results, for the transient response of a packed bed thermal storage unit is presented. The analysis is in two spatial dimensions and considers the influence of both axial and radial thermal dispersion for arbitrary time and radial variations in the inlet fluid temperature. Both charging and recovery modes are included. Spatial variations in void fraction are found to have significant influence on the dynamic response of both fluid and solid temperatures. An unconditionally stable numerical model is developed that predicts the two-dimensional transient response of both solid and fluid phases. The influence of radial velocity variations, wall heat capacity and wall thermal losses are considered. The analysis is valid for fluids of various Prandtl numbers. Experimental measurements of temperature distributions in a randomly packed bed of uniform spheres, with air as the working fluid, compare favorably with the analytical results over a broad range of Reynolds numbers. Results are presented for full-size rock beds which indicate pronounced effects of void distribution in such systems.
Supernovae, Jets, and Collapsars

We continue our study of the possible production of supernovae and a variety of high-energy transients by black hole formation in massive stars endowed with rotation: the "collapsar model." The black hole may form either promptly, since a successful outgoing shock fails to be launched by the collapsed iron core (collapsar Type I), or, in a mild explosion, by fallback (collapsar Type II). In the latter case, the inner layers of the star initially move outward but lack adequate momentum to eject all the matter exterior to the young neutron star. Over a period of minutes to hours, ~0.1-5 M☉ falls back onto the collapsed remnant, turning it into a black hole and establishing an accretion disk. The accretion rate, ~0.001-0.01 M☉ s-1, is inadequate to produce a jet mediated by neutrino annihilation but is similar to what has been invoked in magnetohydrodynamic (MHD) models for gamma-ray bursts (GRBs). This fallback is modeled in detail for two 25 M☉ progenitors using two different one-dimensional hydrodynamics codes, one Lagrangian and one Eulerian. The production and consequences of jets are then explored in both sorts of collapsars. Justification is given for assuming that the jet power is a constant times the mass accretion rate, c2, and the consequences of = 0.001 and 0.01 are explored. Adopting an initial collimation half-angle of 10°, the opening of the jet as it propagates through the exploding star is strongly influenced not only by the jet's kinetic energy but also by its initial pressure and the stellar structure. Cold jets tend to stay collimated and become even more so, sometimes having an angle of only a few degrees when they reach the surface. Jets having higher internal pressure than the stellar material through which they pass, or less initial collimation, spread out and tend to make energetic, asymmetric supernovae accompanied, in helium stars, by weak GRBs. SN 1998bw may have been such an event, and other events having energies between that of ordinary GRBs and GRB 980425 await discovery. In supergiant stars, shock breakout also produces bright X-ray transients that might be a diagnostic of the model, but even the most powerful jets (equivalent isotropic energy 1054 ergs) will not produce a GRB in a red supergiant. For such Type II supernovae the limiting Lorentz factor is Γ ≈ 2. Type II collapsars should be more frequent than Type I and may power the most common form of gamma-ray transient in the universe. However, the GRBs seen by BATSE are, for the most part, too brief to be Type II collapsars. Those are still attributed to prompt black hole formation. Even there though, the diverse energies and time structure reflect chiefly the viewing angle and the variable collimation of the jet inside the star, not a highly variable "central engine." Indeed, collapsar-induced transients may all have a common total energy in the range 1051-1052 ergs.
Strong rotation of an erupting quiescent polar crown prominence

Abstract On 5–6 June 2007, a large quiescent polar crown prominence was observed to erupt by the two Solar Terrestrial Relations Observatory (STEREO) spacecraft. This eruption was particularly visible in the 304 A channel of the Extreme Ultraviolet Imager (EUVI) telescopes. A detailed analysis of the fine structures in the images allows the three-dimensional structure of the erupting prominence to be derived. The prominence is seen to undergo substantial rotation of at least 90 ∘ along the radial axis as it rises, with indications that additional rotation occurred before the prominence rose into the STEREO fields of view. Two temporary structures (“spurs”) are seen to form at an angle to the main spine of the prominence, and are interpreted as signs of reconnection. These reconnection events contribute to the overall rotation of the prominence. A significant fraction of the prominence material is drained through new field lines caused by one of the reconnection events, resulting in only a weak coronal mass ejection event observed by the STEREO and SOHO coronagraphs. The eruption is interpreted as being initiated by the helical kink instability, with subsequent modification by the reconnection events.
The presidential power of unilateral action

In this article we highlight a formal basis for presidential power that has gone largely unappreciated to this point, but has become so pivotal to presidential leadership and so central to an understanding of presidential power that it virtually defines what is distinctively modern about the modern presidency. This is the president’s formal capacity to act unilaterally and thus to make law on his own. Our central purpose is to set out a theory of this aspect of presidential power. We argue that the president’s powers of unilateral action are a force in American politics precisely because they are not specified in the Constitution. They derive their strength and resilience from the ambiguity of the contract. We also argue that presidents have incentives to push this ambiguity relentlessly to expand their own powers—and that, for reasons rooted in the nature of their institutions, neither Congress nor the courts are likely to stop them. We are currently in the midst of a research project to collect comprehensive data for testing this theory—data on what presidents have done, as well as on how Congress and the courts have responded. Here we provide a brief history of unilateral action, with special attention to the themes of our theoretical argument. We also make use of some early data to emerge from our project. For now it appears that the theory is well supported by the available evidence. This is a work in progress, however, and more is clearly needed before definitive conclusions can be justified. A few observations about politics are so widely accepted that virtually all political scientists have committed them to memory. One of these is Richard Neustadt’s (1960) famous dictum, “Presidential power is the power to persuade,” which expresses, in shorthand form, his view that the powers of the modern American presidency are rooted in the personal qualities of the individual occupying the office—in his skills, his temperament, and his experience. This notion of the personal presidency dominated the field for decades, but its influence is on the decline. The main reason is that it seems increasingly out of sync with the facts. The personal presidency became a popular theoretical notion just as the American presidency was experiencing tremendous growth c
Solute-Induced Photo-Ionization of Nonpolar Liquids

Transient dc conductivity measurements of anthracene solutions in cyclohexane have provided evidence for solvent ionization following irradiation with 248 nm excimer laser pulses. A mechanism resulting in a cyclohexane cation and an anthracene anion as near neighbors can explain the experimental observations: a high mobility species, 7 to 8 absorbed photons per solute molecule, intensity dependence, and absence of enhanced hydrogen generation. The nature of the high-mobility species is discussed and the contribution of geminate ions to transient dc conductivity measurements is analyzed. A photo-ionization apparatus with 20 ps time resolution is being developed to observe the transient ions spectroscopically. Such a system may enable observation of solute-induced ionization in solvents having normal mobility cations.
Careers and wages in the Dutch East India Company

Inter-continental trade brought a novel form of organizing business to early modern Europe: the multinational firm. Headquartered in Europe and operating in Asia, the success of the East India Companies depended largely on the management of overseas outposts and their corresponding labor force. Using a dataset of 115 individuals hired in Europe to work in Asia, I present the internal structure of the careers and wages of civil servants in the Dutch East India Company in the eighteenth century. There were stable career paths, fast tracks in promotions, and sizable returns to tenure. Despite the 300-year-old evidence, the VOC conforms rather well with present personnel practices and theories of internal labor markets.
Should the Upper Tracts be Imaged for Microscopic Haematuria

OBJECTIVE To determine the relative prevalence of various definitions of microscopic haematuria (MH) in patients with renal neoplasms and controls, and to predict the likely outcome of renal imaging for those definitions. PATIENTS AND METHODS In a retrospective case-control study 278 adult men and woman seen between 1998 and 2003 with untreated renal neoplasms were compared to controls matched for age and sex. All cases and controls had renal imaging within 6 months of a urine analysis. Patients were excluded for gross haematuria or other conditions associated with MH but not relevant to upper tract imaging. Adjusted odds ratios (OR) computed for 13 definitions of MH by conditional logistic regression were the primary outcome measures. Additional outcome measures were ORs in selected subsets. Hypothetical performance characteristics of a positive urine analysis were then derived to predict the likely results of detecting renal neoplasms for each definition of MH. RESULTS The OR (95% confidence interval) for the entire series of cases and controls, both symptomatic and asymptomatic, was 2.0 (1.02–3.92, P = 0.04) for MH defined as ≥ 4 red blood cells per high-power field (RBC/HPF) and 2.2 (1.09–4.52, P = 0.03) for ≥ 5 RBC/HPF. No significant OR was calculated for ≤ 3 RBC/HPF, nor for a subgroup of patients with MH in a routine urine analysis obtained during a periodic health examination. Symptomatic patients had an OR of 13.68 (1.6–117.1, P = 0.02) for MH defined as ≥ 5 RBC/HPF. The sensitivity of a positive test decreased from 24.8% to 5.04% as the definition for MH became more stringent. The theoretical positive predictive value (assuming a prevalence of renal cell neoplasms of 0.25%) of the most stringent definition of MH was 0.58%. CONCLUSIONS Patients with renal neoplasms have about twice the prevalence of MH with ≥ 4 or 5 RBC/HPF in a single urine sample compared with matched controls, but this difference has little impact on the hypothetical detection rate of renal cancer. Imaging the kidney for low-grade MH in a routine urine analysis discovered at a periodic health examination in an otherwise asymptomatic patient is tantamount to screening without cause, and can be deferred for selected patients. The clinical context is as important as the degree of MH when deciding to image the kidneys.
RADAR DETECTION OF PRECIPITATION

Abstract Detection of precipitation by radar is possible because of the scattering of high-frequency radio waves by precipitation forms. Radar echoes being thus directly related to precipitation may be classified in a simple manner according to meteorological origin. Precipitation echoes from thunderstorms, showers, cold fronts, and warm fronts are described, classified, and illustrated. Radar equipment suitable for meteorological use is briefly described, with suggestions for application in forecasting and research.
Inequality and Fractionalization

We present evidence that ethnic fragmentation explains variations in per capita income, institutions, and schooling better than income inequality when both are treated as endogenous. To do so, we identify instruments for ethnic fractionalization and income inequality based on historical experience. Using instrumental variables estimation, we find that ethnic fractionalization explains the level of income both when income inequality is included as a control in the estimation and when it is not. However, we find no evidence that income inequality affects the level of income when ethnic fractionalization is properly treated as an endogenous variable. We have similar findings when other development outcomes such as schooling or proxies for institutional quality are used as dependent variables. These results are robust to various controls and changes in the sample size and suggest that some of the previous findings regarding the effect of income inequality on development should be attributed to ethnic fractionalization.
Some Implications of a Scale Invariant Model of Statistical Mechanics to Classical and Relativistic Thermodynamics

Some implications of a scale invariant model of statistical mechanics to the mechanical theory of heat of Helmholtz and Clausius are described. Modified invariant definitions of heat and entropy are presented closing the gap between radiation and gas theory. Modified relativistic transformations of pressure, Boltzmann constant, entropy, and density are introduced leading to transformation of ideal gas law. Following Helmholtz the total thermal energy of thermodynamic system is decomposed into free heat U and latent heat p V and identified as modified form of the first law of thermodynamics Q = H = U + p V. Subjective versus objective aspects of Boltzmann thermodynamic entropy versus Shannon information entropy are discussed. Also, modified thermodynamic properties of ideal gas are presented. The relativistic thermodynamics being described is in accordance with Poincare - Lorentz dynamic theory of relativity as opposed to Einstein kinematic theory of relativity since the former theory that is based on compressible ether of Planck is causal as was emphasized by Pauli.
Use of portable monitoring for sleep-disordered breathing treated with an oral appliance

The potential use of a portable monitor to assess the outcome of treatment with an oral appliance would ideally be performed by the dentist who is managing the patient's sleep-disordered breathing. Portable monitoring is one of the most cost-effective ways to assess the response to the oral appliance, to determine if further adjustment to the appliance is needed, and to retest to determine the current status following any adjustment. This article emphasizes the use of portable monitors primarily for follow-up care and assessment as opposed to diagnosis or, as it is sometimes referred to, screening.
Primeras experiencias en anestesia para transplante hepático 1965–1980

Ongoing advances in anaesthesiology have kept the speciality young through implementing new technologies in managing patients, in the search for the safest anaesthetic technique and that which has the least secondary effects. Of course, this has been due to anaesthesia currently managing very narrow therapeutic ranges having a great probability of secondary effects occurring when using different anaesthetic techniques (1-3).
Temporary layoffs in the U.S. unemployment insurance system: A comparison of two experience rating methods

Abstract This study presents a comparison of temporary layoff behavior caused by the two most common methods of experience rating in the U.S. unemployment insurance system, the reserve ratio and the benefit ratio methods. Differences in layoff paths arise from different adjustment processes. Under the former, layoff rates adjust gradually to their optimal levels whereas under the latter, layoff rates adjust instantaneously. This leads to important differences in average layoff rates. However, neither method is judged to be superior in all circumstances.
Studies on isozymes of fructose-1,6-diphosphate aldolase during amphibian development. II. Characterization of isozymes in the egg of Rana pipiens.

Abstract 1. 1. The types of fructose-1,6-diphosphate aldolases (ketose-1-phosphate aldehyde-lyase, EC 4.1.2.7; fructose-1,6-diphosphate d -glyceraldehyde-3-phosphate-lyase, EC 4.1.2.13) found in the unfertilized frog egg, as well as in early stages of development, have been investigated to gain insight into the biological significance of aldolases of the A, B, and C types in early embryogenesis. 2. 2. The relative electrophoretic mobilities of the isozymes from egg and adult frog tissues indicated that five-membered hybrid sets of the AC types are present in the unfertilized egg. 3. 3. The five isozymes in egg and in brain have been separated by chromatographic procedures and their properties compared. The substrate specificities, electrophoretic mobilities, and immunological properties of the individual isozymes from both sources were comparable and differed significantly from those of frog liver aldolase (type B). Dissociation and reassociation of a given hybrid isozyme from egg led to the formation of the other four isozymes of aldolase. 4. 4. These studies show that A and C type aldolases, together with their hybrids, are present in the unfertilized frog egg. 5. 5. No marked changes in the relative proportions of the AC isozymes were observed in embryos up to hatching at which time muscle aldolase (type A) increased.
Interstellar Polarization in the Taurus Dark Clouds: Wavelength-dependent Position Angles and Cloud Structure near TMC-1

Systematic variations with wavelength in the position angle of interstellar linear polarization of starlight may be indicative of multiple cloud structure along the line of sight. We use polarimetric observations of two stars (HD 29647 and HD 283809) in the general direction of TMC-1 in the Taurus dark cloud to investigate grain properties and cloud structure in this region. We show the data to be consistent with a simple two-component model in which general interstellar polarization in the Taurus cloud is produced by a widely distributed cloud component with relatively uniform magnetic field orientation; light from stars close to TMC-1 suffers additional polarization arising in one (or more) subcloud(s) with larger average grain size and magnetic field directions different from the general trend. Toward HD 29647 in particular, we show that the unusually low degree of visual polarization relative to extinction is due to depolarization associated with the presence of distinct cloud components in the line of sight with markedly different magnetic field orientations. Stokes parameter calculations allow us to separate the polarization characteristics of the individual components. Results are fitted with the Serkowski empirical formula to determine the degree and wavelength of maximum polarization. Whereas λmax values in the widely distributed material are similar to the average (0.55 μm) for the diffuse interstellar medium, the subcloud in the line of sight to HD 283809, the most heavily reddened star in our study, has λmax ≈ 0.73 μm, indicating the presence of grains ~30% larger than this average. Our model also predicts detectable levels of circular polarization toward both HD 29647 and HD 283809.
On the variety of almost commuting nilpotent matrices

Let V be an n-dimensional vector space over an algebraically closed field and \(\mathcal{N}\) the nilcone of nilpotent endomorphisms of V. We study the variety \( \mathcal{A} = \left\{{(X, Y, i, j) \in \mathcal{N} \times \mathcal{N} \times V \times V^{\ast} \vert [X, Y] = ij}\right\} \) which is closely related to the variety of pairs of nilpotent n × n matrices with commutator of rank at most 1. We describe its irreducible components: two of them correspond to the pairs of commuting matrices, and n − 2 components of smaller dimension corresponding to the pairs of rank one commutator. In our proof we define a map to the zero fiber of the Hilbert scheme of points and study the image and the fibers.
Transverse momentum dependence of the Landau-Pomeranchuk-Migdal effect

We study the transverse momentum dependence of the Landau-Pomeranchuk-Migdal effect in QED, starting from the high energy expansion of the solution of the Dirac equation in the presence of an external field. The angular integrated energy loss formula differs from an earlier expression of Zakharov by taking finite kinematical boundaries into account. In an expansion in powers of the opacity of the medium, we derive explicit expressions for the radiation cross section associated with N = 1, 2 and 3 scatterings. We verify the Bethe-Heitler and the factorization limit, and we calculate corrections to the factorization limit proportional to the square of the target size. A closed form expression valid to arbitrary orders in the opacity is derived in the dipole approximation. The resulting radiation spectrum is non-analytic in the coupling constant which is traced back to the transverse momentum broadening of a hard parton undergoing multiple small angle Moliere scattering. In extending the results to QCD, we test a previously used dipole prescription by comparing to direct pQCD results for N = 1 and 2. For N = 1, the QCD dipole prescription reproduces exactly the Bertsch-Gunion radiation spectrum. For N = 2, we find a sizeable correction which reduces to a multiplicative factor 17/8 at large separation.
A prospectus on integrated electronics and computer architecture

In order to assess the impact of any technological breakthroughs on the computer user, it is first necessary to understand the nature of the computer user's problem in its present context. Indeed, it is a source of considerable disappointment to some that radical improvements in technology over the past several decades have resulted in noncommensurate impact on the user. The purpose of this paper is to examine the question: "What will be the impact of integrated circuits or integrated electronics on computer architecture?" In the first part of the paper we will study the present picture of computing and show that, if no changes are made from present operating procedures, the impact will be small. In the second part of the paper, we analyze several aspects of computing to find conditions which will enlarge the impact. The final part of the paper will list a number of open problems in computing for which integrated electronics may provide a solution.
Muon capture in the shell model

Abstract The Primakoff Hamiltonian is used in conjunction with the nuclear shell model to predict muon capture rates to the bound states of N16, O19 and H3. Central values obtained are for N16:Λ = 20 × 103 sec−1, for O19:Λ = 1350 sec−1 and for H3:Λ = 1250 sec−1.
Nonlinear effects on inviscid liquid column oscillations

The nonlinear corrections to the natural modes of oscillation of the finite length inviscid liquid column are determined via the method of domain perturbation and Poincare expansion. In this weakly non-linear analytical treatment a hierarchy of systems of governing equations with associated boundary and interface conditions are developed in the expansion parameter. At first order, linear results are recovered. At second order, the correction to the velocity potential and interface shape are determined. The correction to the interface shape is found to result in a modification of the mean shape. The structure of the velocity potential must be modified to include a source term. At third order, the solvability condition is obtained, and yields corrections to the oscillation frequency. The nonlinear effects are found to be of the softening type.
Spontaneous lepton-number violation and de-leptonization in stellar collapse

Abstract We consider core collapse in weak interaction models where global lepton-number invariance is spontaneously broken. We find that the initial neutrino number prevents finite temperature restoration of lepton-number conservation. Assuming the lepton-number violating reactions occur rapidly, we show that the neutrino number is driven to a sufficiently small value to allow electron capture reactions to de-leptonize the core, and lead to a high-entropy collapse.
A trial of 17 alpha-hydroxyprogesterone caproate to prevent prematurity in twins.

Background In singleton gestations, 17 alpha-hydroxyprogesterone caproate (17P) has been shown to reduce the rate of recurrent preterm birth. This study was undertaken to evaluate whether 17P would reduce the rate of preterm birth in twin gestations. Methods We performed a randomized, double-blind, placebo-controlled trial in 14 centers. Healthy women with twin gestations were assigned to weekly intramuscular injections of 250 mg of 17P or matching placebo, starting at 16 to 20 weeks of gestation and ending at 35 weeks. The primary study outcome was delivery or fetal death before 35 weeks of gestation. Results Six hundred sixty-one women were randomly assigned to treatment. Baseline demographic data were similar in the two study groups. Six women were lost to follow-up; data from 655 were analyzed (325 in the 17P group and 330 in the placebo group). Delivery or fetal death before 35 weeks occurred in 41.5% of pregnancies in the 17P group and 37.3% of those in the placebo group (relative risk, 1.1; 95% con...
Man-machine interaction for the discovery of high-level patterns

Social scientists are largely concerned with the discovery of patterns and relationships in multivariate data. The techniques used have been, for the most part, the standard tools of multivariate analysis---correlation, regression, factor analysis, and so forth. Unfortunately, the nature of these techniques has tended to impose implicit theoretical assumptions and constraints on the social sciences. The conceptualization of a variable as the weighted sum of other variables is methodologically unhealthy in the study of human beings and societies, in which it is precisely the complex interaction effects among variables which are of the most theoretical interest. In the social sciences it is especially prevalent, and especially significant, for the relationship between two variables to be dependent on the values of other variables---and for the nature of this dependence to be a function of still other variables. Traditional statistical methods are ill-suited for uncovering such hierarchies of interaction effects.
Treatment of recurrent glioblastoma multiforme with GliaSite brachytherapy.

Purpose: In this study, we assess the efficacy of GliaSite brachytherapy in the treatment of patients with recurrent glioblastoma multiforme (GBM). Methods and Materials: Between 1999 and 2004, 24 patients with recurrent glioblastoma multiforme were treated with the GliaSite Radiation Therapy System (RTS). The GliaSite is an inflatable balloon catheter that is placed in the resection cavity at the time of surgical resection. Low-dose-rate radiation is then delivered locally by temporarily inflating the balloon with an aqueous solution of organically bound 125 I (Iotrex [sodium 3-( 125 I)-iodo-4-hydroxybenzenesulfonate]). Patients at the Johns Hopkins Hospital with recurrent GBM, who were previously treated with surgery and external beam radiotherapy, underwent surgical resection followed by GliaSite balloon implantation. Subsequently, the patients received radiation therapy using the GliaSite to a mean dose of 53.1 Gy. Ten patients were male, and 14 patients were female. The mean age was 48.1 years. All patients had pathologically confirmed recurrent GBM. The median Karnofsky performance status (KPS) was 80. Median follow-up time was 21.8 months. Results: At the time of analysis, 18 patients (75%) had died; 6 patients (25%) were alive. Median survival from diagnosis for all patients was 23.3 months. Median survival after GliaSite brachytherapy was 9.1 months. Patients with a KPS ≥70 had a median survival of 9.3 months, whereas patients with a KPS p Conclusions: GliaSite radiotherapy confers a prolongation of survival in patients with recurrent glioblastoma multiforme compared to historical controls with recurrent GBM. GliaSite therapy leads to a favorable survival outcome of 9.3 months in patients with KPS ≥70, but only 3.1 months in patients with KPS
Elastic Properties of Hybrid Graphene/Boron Nitride Monolayer

Recently, hybridized monolayers consisting of hexagonal boron nitride (h-BN) phases inside a graphene layer have been synthesized and shown to be an effective way of opening band gap in graphene monolayers (Ci et al. in Nat Mater 9(5):430-435, 2010). In this paper, we report a first-principles density functional theory study of the h-BN domain size effect on the elastic properties of graphene/boron nitride hybrid monolayers (h-BNC). We found that both in-plane stiffness and longitudinal sound velocity of h-BNC linearly decrease with h-BN concentration. Our results could be used for the design of future graphene-based nanodevices of surface acoustic wave sensors and waveguides.
Implementation of Kumar's correspondence

In 1997, N.M. Kumar published a paper which introduced a new tool of use in the construction of algebraic vector bundles. Given a vector bundle on projective n-space, a well known theorem of Quillen-Suslin guarantees the existence of sections which generate the bundle on the complement of a hyperplane in projective n-space. Kumar used this fact to give a correspondence between vector bundles on projective n-space and vector bundles on projective (n−1)-space satisfying certain conditions. He then applied this correspondence to establish the existence of many, previously unknown, rank two bundles on projective fourspace in positive characteristic. The goal of the present paper is to give an explicit homological description of Kumar's correspondence in a setting appropriate for implementation in a computer algebra system.
Enantioselective Friedel−Crafts Alkylations of α,β-Unsaturated 2-Acyl Imidazoles Catalyzed by Bis(oxazolinyl)pyridine−Scandium(III) Triflate Complexes

An enantioselective Friedel−Crafts alkylation with α,β-unsaturated 2-acyl imidazoles and electron-rich aromatic nucleophiles catalyzed by bis(oxazolinyl)pyridine−scandium(III) triflate complexes has been accomplished. These α,β-unsaturated 2-acyl imidazoles are effective electrophiles for the Friedel−Crafts reaction. The resulting adduct 2-acyl imidazole is easily converted to amides, esters, carboxylic acids, ketones, and aldehydes by methylation and subsequent displacement of the imidazole residue.
Computing CHEMKIN Sensitivities Using Complex Variables

This paper discusses an accurate numerical approach based on complex variables for the computation of the Jacobian matrix of complex chemical reaction mechanisms. The Jacobian matrix is required in the calculation of low dimensional manifolds during kinetic chemical mechanism reduction. The approach is suitable for numerical computations of large-scale problems and is more accurate than the finite difference approach of computing Jacobians. The method is demonstrated via a nonlinear reaction mechanism for the synthesis of Bromide acid and a H 2 /Air mechanism using a modified CHEMKIN package. The Bromide mechanism consisted of five species participating in six elementary chemical reactions and the H 2 /Air mechanism consisted of II species and 23 reactions. In both cases it is shown that the method is superior to the finite difference approach of computing derivatives with an arbitrary computational step size h.
Structural breaks and consumer credit: Is consumption smoothing finally a reality?

Abstract Has structural change in consumer credit made consumption smoother? Given recent empirical analysis the consumer’s inability to smooth consumption appears as prevalent as ever. In this paper, however, I show that structural change in consumer credit appears to have made consumption smoothing a reality. First, using the statistical methods of Bai and Perron [Bai, J., Perron, P., 1998. Estimating and testing linear models with multiple structural changes. Econometrica 66(1), 47–78; Bai, J., Perron, P., 2003. Computation and analysis of multiple structural change models. Journal of Applied Econometrics 18(1), 1–22], I find structural breaks in the series for consumer credit and consumption at various points from 1959 to 2005. Most notably, structural breaks occur in total consumer credit and revolving consumer credit in the 1990s. Based on the break date estimates, I estimate a structural equation of consumption growth in line with previous empirical tests of the permanent-income hypothesis. Consumption smoothing is evident in the data after the mid-1980s and into the 2000s. The findings of this paper have important implications for a variety of economic research. The evidence for consumption smoothing bears directly on the efficacy of monetary policy and fiscal policy, as well as on the recent discussion of the decline in macroeconomic volatility since the 1980s.
Fuel–oxidizer mixtures: their stabilities and burn characteristics

A survey of the stability and performance of eleven solid oxidizers and thirteen fuels was performed by differential scanning calorimetry, simultaneous differential thermolysis, and hot-wire ignition. Sugars, alcohols, hydrocarbons, benzoic acid, sulfur, charcoal, and aluminum were used as fuels; all fuels except charcoal and aluminum melted at or below 200 °C. It was found that the reaction between the oxidizer and the fuel was usually triggered by a thermal event, i.e., melt, phase change, or decomposition. Although the fuel usually underwent such a transition at a lower temperature than the oxidizer, the phase change of the fuel was not always the triggering event. When sugars or sulfur were the fuels, their phase change usually triggered their oxidation. However, three oxidizers, KNO3, KClO4, and NH4ClO4, tended to react only after they underwent a phase change or began to decompose, which meant that their oxidization reaction, regardless of the fuel, was usually above 400 °C. KClO4–fuel mixtures decomposed at the highest temperatures, often over 500 °C, with the ammonium salt decomposing almost 100 °C lower. Mixtures with ammonium nitrate (AN) also decomposed at much lower temperatures than those with the corresponding potassium salt. With the exception of the oxidizers triggered to react by the phase changes of the polyols and sulfur, the oxidizer–fuel mixtures generally decomposed between 230 and 300 °C, with AN formulations generally decomposing at the lowest temperature. In terms of heat release, potassium dichromate–fuel mixtures were the least energetic, generally releasing less than 200 J g−1. Most of the mixtures released 1000–1500 J g−1, with potassium chlorate, ammonium perchlorate, and AN releasing significantly more heat, around 2000 J g−1. When the fuel was aluminum, most of the oxidizers decomposed below 500 °C leaving the aluminum to oxidize at over 800 °C. Only two oxidizers reduced the temperature of the aluminum exotherm—chlorate and potassium nitrite. To go to temperatures above 500 °C, unsealed crucibles were necessary, and with these containers, the endothermic volatilization of reactants and products effectively competed against the exothermic decomposition so that heat release values were artificially low.
ELECTROWEAK SYMMETRY BREAKING CIRCA 2005

Recent progress in both the experimental and theoretical explorations of electroweak symmetry breaking is surveyed.
The Common Law Power of the Legislature: Insurer Conversions and Charitable Funds

New York's Empire Blue Cross and Blue Shield conversion from nonprofit to for-profit form has considerable legal significance. Three aspects of the conversion make the case unique: the role of the state legislature in directing the disposition of the conversion assets, the fact that it made itself the primary beneficiary of those assets, and the actions of the state attorney general defending the state rather than the public interest in the charitable assets. Drawing on several centuries of common law rejecting the legislative power to direct the disposition of charitable funds, this article argues that the legislature lacked power to control the conversion and direct the disposition of its proceeds and that its actions not only undermined the nonprofit form but also raised constitutional concerns.
Anomalous diffusion in quantum Brownian motion with colored noise

Anomalous diffusion is discussed in the context of quantum Brownian motion with colored noise. It is shown that earlier results follow simply and directly from the fluctuation-dissipation theorem. The limits on the long-time dependence of anomalous diffusion are shown to be a consequence of the second law of thermodynamics. The special case of an electron interacting with the radiation field is discussed in detail. We apply our results to wave-packet spreading.
Discovery of scandium, titanium, mercury, and einsteinium isotopes

Currently, 23 scandium, 25 titanium, 40 mercury, and 17 einsteinium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.
Synthesis and Characterization of Bimagnetic Bricklike Nanoparticles

Bimagnetic FePt/CoFe2O4 nanoparticles having a bricklike morphology were synthesized by growing a soft magnetic CoFe2O4 phase on FePt cubic nanoparticle seeds. The size of the soft phase could be controlled by tuning the material ratio of the FePt seeds to the CoFe2O4 component. To obtain magnetic hardening, the as-synthesized bricklike nanoparticles were annealed at elevated temperatures under a reductive atmosphere to convert the disordered face-centered cubic FePt phase into the ordered L10 phase having high magnetic anisotropy. When the particles were annealed, a gradual change was observed in morphology from bricklike particles to spherical polycrystalline nanocomposite particles because of diffusion. Meanwhile, the magnetic energy density was enhanced as a result of the exchange coupling between the hard and soft phases. The enhancement was dependent on the ratio of the volumes of the soft phase and the hard phase.
How typical are pathological foliations in partially hyperbolic dynamics: An example

We show that for a large space of volume preserving partially hyperbolic diffeomorphisms of the 3-torus with non-compact central leaves the central foliation generically is non-absolutely continuous.
Uncertainty in the Output of Artificial Neural Networks

The goal for artificial neural networks (ANNs) in two-class classification problems is to predict the class membership accurately. Performance evaluation of ANNs focuses usually on the collective accuracy over a large number of cases in the prediction of the class membership, often measured by receiver operating characteristic (ROC) curve and area under the ROC curve (AUC). We show that with finite number of training cases, the output value of the ANN is a statistical random variable that exhibits uncertainty. We show that this uncertainty in the ANN output can be studied by training multiple ANNs of identical structure on a single set of training cases but with different random initialization, thereby causing the ANNs to arrive at not-necessarily-identical weight values at the conclusion of satisfactory training. We found that this variability in the ANN output is small but not negligible and that it can be important in CAD applications in which the ANN output is to be interpreted by a human observer rather than to be compared with a fixed threshold value in fully automated machine classification.
Neutrino oscillation workshop 2000: Conference summary

Abstract The NOW2000 Workshop summarized the present status and future possibilities for all aspects of neutrino physics and astrophysics. Neutrino oscillation physics has truly come of age in the last few years. It is now data driven (analogous to cosmology and much of high energy physics in general). Experimental techniques and the theoretical interpretation have developed dramatically. An example of the latter includes the more realistic analysis of neutrino oscillations in the framework of 3 or more mass eigenstates. The phenomenological emphasis has shifted from degenerate to hierarchical neutrino spectra.
Integrable and proper actions on C*-algebras, and square-integrable representations of groups

Abstract We propose a definition of what should be meant by a proper action of a locally compact group on a C *-algebra. We show that when the C *-algebra is commutative this definition exactly captures the usual notion of a proper action on a locally compact space. We then discuss how one might define a generalized fixed-point algebra . The goal is to show that the generalized fixed-point algebra is strongly Morita equivalent to an ideal in the crossed product algebra, as happens in the commutative case. We show that one candidate gives the desired algebra when the C *-algebra is commutative. But very recently Exel has shown that this candidate is too big in general. Finally, we consider in detail the application of these ideas to actions of a locally compact group on the algebra of compact operators (necessarily coming from unitary representations), and show that this gives an attractive view of the subject of square-integrable representations.
Synthesis of fluorine-18 functionalized nanoparticles for use as in vivo molecular imaging agents.

Nanoparticles containing fluorine-18 were prepared from block co-polymers made by ring-opening metathesis polymerization (ROMP). Using the fast initiating ruthenium metathesis catalyst (H2IMes)(pyr)2(Cl)2RuCHPh, narrow polydispersity, amphiphilic block copolymers were prepared from a cinnamoyl-containing, hydrophobic norbornene monomer and a mesylate-terminated, PEG-containing hydrophilic norbornene monomer. Self-assembly into micelles and subsequent crosslinking of the micelle cores by light-activated dimerization of the cinnamoyl groups yielded stable nanoparticles. Incorporation of fluorine-18 was achieved by nucleophilic displacement of the mesylates with the radioactive fluoride ion with 31% incorporation of radioactivity. The resulting positron-emitting nanoparticles are to be used as in vivo molecular imaging agents in tumor imaging.
A Kalman-PDA approach to soft-decision equalization for frequency-selective MIMO channels

This paper develops a low-complexity soft-decision equalization approach for frequency selective multi-input multi-output (MIMO) communication systems. With the help of iterative processing, two detection and estimation schemes based on second-order statistics are harmoniously put together to yield a two-part receiver structure: local multiuser detection (MUD) using soft-decision Probabilistic Data Association (PDA) detection and dynamic noise-interference tracking using Kalman filtering. The proposed Kalman-PDA detector performs local MUD within a subblock of the received data instead of over the entire data set to reduce the computational load. At the same time, all the interference affecting the local subblock, including both multiple access and intersymbol interference (ISI), is properly modeled as the state vector of a linear system and dynamically tracked by Kalman filtering. Two types of Kalman filters are designed, both of which are able to track a finite impulse response (FIR) MIMO channel of any memory length. The overall algorithms enjoy low complexity that is only polynomial in the number of information-bearing bits to be detected, regardless of the data block size. Furthermore, we introduce two optional performance-enhancing techniques: Kalman-PDA with cross-layer automatic repeat request (ARQ) for uncoded systems and code-aided Kalman-PDA for coded systems. Simulations show that both techniques can render error performance that is better than Kalman-PDA alone and competitive to sphere decoding.
Effects of multifunctional crosslinking agents on the thermomechanical properties of polyimide films

The potential of high temperature resistant polymers such as polyimides (PI) and polyphenylquinoxalines (PPQ) as matrix resins in fiber-reinforced composites has not been fully realized to date. One of the problems associated with these resins is that they exhibit creep, or thermoplastic yielding under load at temperatures approaching 316 C (600 F). The purpose of this investigation was to further reduce thermoplastic behavior of polyimide resins by substituting a controlled amount of the diamine monomer with crosslinking agents having a higher amine functionality. The knowledge gained from a study of the thermomechanical properties of the crosslinked resins would then be used in the fabrication of fiber-reinforced polyimide composites. This report describes the synthesis and characterization of three new polyfunctional amines. Polyimide films containing varying amounts of the cross-linking agents were prepared, and their properties compared with those of control samples prepared with difunctional amines. The effect of crosslink density on isothermal weight loss, polymer softening, and glass transition temperatures is discussed.
P-partition products and fundamental quasi-symmetric function positivity

We show that certain differences of productsK"Q"@?"R","@qK"Q"@?"R","@q-K"Q","@qK"R","@q of P-partition generating functions are positive in the basis of fundamental quasi-symmetric functions L"@a. This result interpolates between recent Schur positivity and monomial positivity results of the same flavor. We study the case of chains in detail, introducing certain ''cell transfer'' operations on compositions and a related ''L-positivity'' poset. We introduce and study quasi-symmetric functions called wave Schur functions and use them to establish, in the case of chains, that K"Q"@?"R","@qK"Q"@?"R","@q-K"Q","@qK"R","@q is itself equal to a single generating function K"P","@q for a labeled poset (P,@q). In the course of our investigations we establish some factorization properties of the ring QSym of quasi-symmetric functions.
Spectrally Dispersed K-Band Interferometric Observations of Herbig Ae/Be Sources: Inner Disk Temperature Profiles

We use spectrally dispersed near-IR interferometry data to constrain the temperature profiles of sub-AU-sized regions of 11 Herbig Ae/Be sources. We find that a single-temperature ring does not reproduce the data well. Rather, models incorporating radial temperature gradients are preferred. These gradients may arise in a dusty disk, or may reflect separate gas and dust components with different temperatures and spatial distributions. Comparison of our models with broadband spectral energy distributions suggests the latter explanation. The data support the view that the near-IR emission of Herbig Ae/Be sources arises from hot circumstellar dust and gas in sub-AU-sized disk regions. Intriguingly, our derived temperature gradients appear systematically steeper for disks around higher mass stars. It is not clear, however, whether this reflects trends in relative dust/gas contributions or gradients within individual components.