cssi/SciSciGPT-SciSciNet huggingface dataset:
A wave-envelope technique for wave propagation in non-uniform ducts

The method of variation of parameters is used to analyze wave propagation in variable area, plane ducts with no mean flow. The method has an explicit representation of the fast axial variation of the acoustic modes, and numerical integration is required only for the slower axial variations of the mode amplitudes and phases. Results are presented which demonstrate the numerical advantages of the method. Comparison of the results with those of a small perturbation theory are given. The relationship between this method and the method of weighted- residuals is discussed. 7 among others. Each approach has unique characteristics and advantages, as well as obvious limitations, either of a numerical or physical nature. For example, no tests have been made to establish the range of geometry variations for which the multiple-scale solutions remain valid; direct numerical analyses require small step sizes and large computation times for high frequencies and high-order modes because of the rapid axial and transverse oscillations; and weighted-residual analysis7 also requires a numerical integration over each axial oscillation of the signal although the transverse variations of high-order modes present no difficulty. The computation of these axial variations has been sim- plified in a direct numerical analysis of wave propagation in constant-area ducts by using an estimate of the harmonic axial variations of the fundamental mode.8 This procedure was reportedly advantageous even with estimates that were only moderately accurate. In the work reported here, acoustic propagation in variable- area ducts without mean flow is analyzed by the method of variation of parameters 9 in a manner that incorporates features of several previous investigations. To facilitate the study of high-order modes and multimodal interactions, the acoustic disturbance is represented as a superposition of parallel-duct eigenf unctions. Moreover, the fast axial variation is given explicitly, and numerical integration is required only for the slower axial variations of the amplitudes and the phases of the modes. We have borrowed the term 'wave-envelope method' as a description of this aspect of the method, although in most respects it bears little resemblance to the procedure used by Baumeister.8 Finally, the representation of the acoustic wave is required to satisfy an integrability constraint derived from the wave equation; this feature is similar to that used in the multiple-scale analysis by Nayfeh and Telionis,3 but does not have the small per- turbation limitation.
How Has the Basle Accord Affected Bank Portfolios

Abstract This paper investigates the extent to which the risk-based capital standards, which took effect in 1989, have affected commercial bank portfolios. The new standards give banks an incentive to substitute away from loans, which have a high risk weight, into less risky assets such as government securities. Time-series macro data is used to determine whether the risk-based guidelines have caused unusually large portfolio changes on bank balance sheets. Bank-level data are used to determine how successful banks have been in meeting their capital requirements and to explore the relationship between capital ratios and subsequent portfolio shifts. The principal conclusion of this paper is that both the timing of bank portfolio shifts and the strong relationship in the bank-level data between low risk-based capital ratios and portfolio adjustment (controlling for the ratio of bad loans to assets) are consistent with the view that the risk-based capital standards have significantly affected bank portfolios. During the 1990 and 1991 period, banks were quite successful in raising their capital ratios in order to meet the risk-based capital requirements. However, in order to raise capital ratios, banks decreased lending, particularly to businesses. The evidence suggests that commercial banks have reduced their loans by approximately $150 billion because of the risk-based capital guidelines. To the extent that a "credit crunch" has weakened economic activity since 1990, Basle-induced declines in lending may have been a major cause of this credit crunch. J. Japan. Int. Econ., December 1993, 7(4), pp. 408–440. Department of Economics, Harvard University, Cambridge, Massachusetts 02138.
A conjecture of Ax and degenerations of Fano varieties

James Ax conjectured that every pseudo algebraically closed field is C1. We prove this conjecture in characteristic 0 by relating it to degenerations of Fano varieties.
Development of Steam Generator Components for Open-Cycle MHD

The steam bottoming plant of a coal-fired MHD power station must operate under more severe and demanding conditions than a conventional plant and it must perform several additional functions, such as recovery of the seed material and preheating of pressurized combustion air. In addition, the high NO and CO concentrations, and the large numbers of submicron particles in the entering combustion gas result in unique control problems. Research programs in the United States are directed at the resolution of a number of areas where the operating conditions and requirements of the MHD steam plant differ significantly from those of conventional plants. The more important of these areas are 1) radiant furnace design, 2) secondary combustion, 3) heat exchangers with liquid, semisolid, and solid deposits of seed material, 4) materials of construction, 5) particulate control, 6) seed recovery and recycling, and 7) off-design operation. This paper presents recent experimental data and summarizes the status of the development program.
On twisted representations of vertex algebras

Abstract In this paper, we develop a formalism for working with representations of vertex and conformal algebras by generalized fields—formal power series involving non-integer powers of the variable. The main application of our technique is the construction of a large family of representations for the vertex superalgebra V Λ corresponding to an integer lattice Λ. For an automorphism σ : V Λ → V Λ coming from a finite-order automorphism σ : Λ→Λ we find the conditions for existence of twisted modules of V Λ . We show that the category of twisted representations of V Λ is semisimple with finitely many isomorphism classes of simple objects.
Thrombopoietin and the Hematopoietic Stem Cell

The molecular mechanisms that underlie the favorable effects of thrombopoietin on stem cell survival, self-renewal, and expansion are unknown. On the basis of known effects of HoxB4, HoxA9, and vascular endothelial cell growth factor on stem cells, we explored whether TPO might affect these pathways. We found that TPO enhances the transcription of HoxB4, induces the nuclear localization of HoxA9, and upregulates VEGF expression by reducing the ubiquination of hypoxia inducible factor.
Effect of stiffness characteristics on the response of composite grid-stiffened structures

A study of the effect of stiffness discontinuities and structural parameters on the response of continuousfilament grid-stiffened flat panels is presented. The buckling load degradation due to manufacturing-introduced stiffener discontinuities associated with a filament cut-and-add approach at the stiffener intersections is investigated. For practical discontinuity sizes, the reduction in buckling load is negligible. The degradation of buckling resistance in isogrid flat panels subjected to uniaxial compression, combined axial compression, shear loading conditions, and induced damage, is quantified using finite element analysis. The combined loading case is the most critical one. The benefit of utilizing nonsolid stiffener cross sections is evaluated. Nonsolid stiffener cross sections, such as a foam-filled blade or hat with a 0-deg dominant cap, result in grid-stiffened structures that are structurally very efficient for wing and fuselage applications. The results of a study of the ability of gridstiffened structural concepts to enhance the effective Poisson's ratio of a panel is presented. Grid-stiffened concepts create a high effective Poisson's ratio which can produce large camber deformations for certain elastic tailoring applications.
New anabolic therapies in osteoporosis

Anabolic agents represent an important new advance in the therapy of osteoporosis. Their potential might be substantially greater than the anti-resorptives. Because the anti-resorptives and anabolic agents work by completely distinct mechanisms of action, it is possible that the combination of agents could be significantly more potent than either agent alone. Recent evidence suggests that a plateau in BMD might occur after prolonged exposure to PTH. Anti-resorptive therapy during or after anabolic therapy might prevent this skeletal adaptation. Protocols to consider anabolic agents as intermittent recycling therapy would be of interest. Of all the anabolics, PTH is the most promising. However, there are unanswered questions about PTH. More studies are needed to document an anabolic effect on cortical bone. More large-scale studies are needed to further determine the reduction in nonvertebral fractures with PTH, especially at the hip. In the future, PTH is likely to be modified for easier and more targeted delivery. Oral or transdermal delivery systems may become available. Recently, Gowen et al have described an oral calcilytic molecule that antagonizes the parathyroid cell calcium receptor, thus stimulating the endogenous release of PTH. This approach could represent a novel endogenous delivery system for intermittent PTH administration. Rising expectations that anabolic therapies for osteoporosis will soon play a major role in treating this disease are likely to fuel further studies and the development of even more novel approaches to therapy.
Mapping the mesoscale interface structure in polycrystalline materials.

Abstract A new experimental approach to the quantitative characterization of polycrystalline microstructure by scanning electron microscopy is described. Combining automated electron backscattering diffraction with conventional scanning contrast imaging and with calibrated serial sectioning, the new method (mesoscale interface mapping system) recovers precision estimates of the 3D idealized aggregate function G ( x ). This function embodies a description of lattice phase and orientation (limiting resolution∼1°) at each point x (limiting spatial resolution∼100 nm), and, therefore, contains a complete mesoscale description of the interfacial network. The principal challenges of the method, achieving precise spatial registry between adjacent images and adequate distortion correction, are described. A description algorithm for control of the various components of the system is also provided.
Rotor Power Losses in Planar Radial Magnetic Bearings—Effects of Number of Stator Poles, Air Gap Thickness, and Magnetic Flux Density

Rotor power losses in magnetic bearings cannot be accurately calculated at this time because of the complexity of the magnetic field distribution and several other effects. The losses are due to eddy currents, hysteresis, and windage. This paper presents measured results in radial magnetic bearing configurations with eight pole and 16 pole stators and two laminated rotors. Two different air gaps were tested. The rotor power losses were determined by measuring the rundown speed of the rotor after the rotor was spun up to speeds of approximately 30,000 rpm, DN + 2,670,000 mm-rpm, in atmospheric air. The kinetic energy of the rotor is converted to heat by magnetic and air drag power loss mechanisms during the run down. Given past publications and the opinions of researchers in the field, the results were quite unexpected. The measured power losses were found to be nearly independent of the number of poles in the bearing. Also, the overall measured rotor power loss increased significantly as the magnetic flux density increased and also increased significantly as the air gap thickness decreased. A method of separating the hysteresis, eddy current and windage losses is presented. Eddy current effect were found to be the most importantmore » loss mechanism in the data analysis, for large clearance bearings. Hysteresis and windage effects did not change much from one configuration to the other.« less
An explicit formula for differences between Laplacian-eigenvector components using coalesced graphs

Abstract We obtain an explicit formula for the absolute difference between two eigenvector components for a weighted graph’s Laplacian matrix, in terms of the Laplacian’s eigenvalues as well as the eigenvalues of matrices associated with certain coalesced graphs. We then briefly illustrate two uses of this formula, in analyzing graph modifications.
Delivery to the Customer's Door: Efficiency, Regulatory Policy, and Integrated Rail-Truck Operations, 1900–1938

During the first third of the twentieth century, U. S. railroad executives offered local collection and delivery trucking operations. Railroad managers claimed, with justification, that these services were necessary to reduce congestion at urban freight terminals, and to increase the operating efficiency. Yet, executives also employed collection and delivery practices to discriminate against shippers and communities, and to draw business away from rival carriers, in violation of the 1887 Interstate Commerce Act, the 1903 Elkins Act, and the Transportation Act of 1920. During the 1920s, as competition from independent truckers became more intense, railroad managers used their inherent advantage in line-haul service to cross-subsidize local delivery services, to the detriment of independent motor carriers—an issue of considerable concern to Interstate Commerce Commission (ICC) commissioners, following the passage of the 1935 Motor Carrier Act. The railroads' emphasis on the productive efficiency associated with local trucking operations conflicted with the allocative efficiency advocated by federal courts and by the ICC. Commissioner Joseph B. Eastman, in particular, emphasized both the potential benefits and the potential dangers associated with coordinated rail-truck service. More broadly, the status of that service, as one of the few forms of transportation that lay beyond the ICC's authority, stemmed from a complex interaction, over several decades, between all three branches of the federal government. By 1938, the ICC commissioners had concluded that the railroads' local delivery operations occupied a nebulous region between rail and truck regulation. While lawful, they did not serve as a model for post-1945 efforts to achieve integrated, multi-modal transportation services.
The assimilation of amino acids by respiring washed Staphylococci.

Abstract Washed staphylococcal cells, while oxidizing glucose, are able to perform certain coupled assimilative reactions which are presumably a part of the complex of reactions involved in bacterial growth. When potassium phosphate is the principal growth requirement provided, other than glucose and oxygen, inorganic phosphate is accumulated by the cells, in proportion to the amount of glucose oxidized. There is a general increase and isotopic exchange in most of the cell phosphate constitutents; the latter can happen, but more slowly, without the glucose at 37 °C. The most unique effect of the presence of glucose is an increase in net amount and possibly also exchange rate of some of the phosphorus associated with the trichloroacetic acid-insoluble nucleoprotein fraction. When various incomplete mixtures of amino acids are provided to the respiring cell suspensions, amino nitrogen is taken up by the cells, in amounts increasing with the complexity of the mixture. The amino acids are found in the trichloroacetic acid-insoluble fraction, from which they are in general recoverable by hydrolysis, so it is concluded that protein synthesis has occurred by combination of the added amino acids and those previously present. This synthesis is also closely coupled to the oxidation of glucose, and, as is the case for phosphate assimilation, s less effective when other substrates are used, deaminative degradation being the other alternative. That synthesis of protein by whole cells is connected with phosphorylative processes seems to be indicated by the interrelation of the phosphate and amino nitrogen assimilation. The net accumulation of phosphate in the cells and particularly in the nucleoprotein fraction is diminished, more or less characteristically in proportion to the success with which amino acids are being incorporated. Both gramicidin and 2,4-dinitrophenol block phosphate assimilation and amino acid oxidation, but only the latter markedly inhibits protein synthesis from amino acids. It is concluded that protein synthesis from amino acids is a preferential alternative to phosphate accumulation brought about by some phosphorylated intermediate common to both processes, and that for each phosphorus atom not incorporated approximately two atoms of amino nitrogen can be utilized for protein formation.
Prospects for Coal as a Direct Fuel and Its Potential Through Application of Liquefaction And Gasification Technology

Examination of the resource base for coal indicates that there will be no problem (other than man-made) in availability for legitimate domestic energy requirements within the next 20 years. As the more convenient forms of fossil energy (oil and gas) decline in domestic availability we will turn to coal out of necessity; provided that total energy growth remains below 3 percent, the coal industry will be able to fill the gap, though with great difficulty. Coal production will increase from 1975's likely production of 625 million tons to 1,025 million tons by 1985 and 1.7 billion tons by 1995. During the middle years of the 20-year forecast period, coal conversion plants, heavily subsidized either overtly or covertly, will be built to verify technology now available and to act as insurance against unforeseen failures of oil and gas supply.
An infeasible-start algorithm for linear programming whose complexity depends on the distance from the starting point to the optimal solution

This paper presents an algorithm for solving a linear program LP (to a given tolerance) from a given prespecified starting point. As such, the algorithm does not depend on any “bigM” initialization assumption. The complexity of the algorithm is sensitive to and is dependent on the quality of the starting point, as assessed by suitable measures of the extent of infeasibility and the extent of nonoptimality of the starting point. Two new measures of the extent of infeasibility and of nonoptimality of a starting point are developed. We then present an algorithm for solving LP whose complexity depends explicitly and only on how close the starting point is to the set of LP feasible and optimal solutions (using these and other standard measures), and also onn (the number of inequalities). The complexity results using these measures of infeasibility and nonoptimality appear to be consistent with the observed practical sensitivity of interior-point algorithms to certain types of starting points. The starting point can be any pair of primal and dual vectors that may or may not be primal and/or dual feasible, and that satisfies a simple condition that typically arises in practice or is easy to coerce.
Induction of eIF-4E phosphorylation by the addition of L-pyrroline-5-carboxylic acid to rabbit reticulocyte lysate

Addition of L-pyrroline-5-carboxylic acid to reticulocyte lysates inhibits protein synthesis and induced phosphoproteins of 25 and 14 kDa. The 25 kDa phosphoprotein had the same Mr and pI as phosphorylated eIF-4E. Incubation of lysates with L-pyrroline-5-carboxylic acid did not alter the crosslinking of eIF-4E to reovirus mRNA caps. These results suggest that modifications of the translational apparatus other than eIF-4E phosphorylation may mediate the inhibitory effect seen with L-pyrroline-5-carboxylic acid and/or that phosphorylation of eIF-4E may effect functions subsequent to its interaction with the mRNA cap such as protein-protein interactions with other cap-specific translation factors.
Nonlinear waves in capillary electrophoresis.

Electrophoretic separation of a mixture of chemical species is a fundamental technique of great usefulness in biology, health care, and forensics. In capillary electrophoresis, the sample migrates in a microcapillary in the presence of a background electrolyte. When the ionic concentration of the sample is sufficiently high, the signal is known to exhibit features reminiscent of nonlinear waves including sharp concentration “shocks.” In this paper, we consider a simplified model consisting of a single sample ion and a background electrolyte consisting of a single coion and a counterion in the absence of any processes that might change the ionization states of the constituents. If the ionic diffusivities are assumed to be the same for all constituents the concentration of sample ion is shown to obey a one dimensional advection diffusion equation with a concentration dependent advection velocity. If the analyte concentration is sufficiently low in a suitable nondimensional sense, Burgers’ equation is recovered, and thus the time dependent problem is exactly solvable with arbitrary initial conditions. In the case of small diffusivity, either a leading edge or trailing edge shock is formed depending on the electrophoretic mobility of the sample ion relative to the background ions. Analytical formulas are presented for the shape, width, and migration velocity of the sample peak and it is shown that axial dispersion at long times may be characterized by an effective diffusivity that is exactly calculated. These results are consistent with known observations from physical and numerical simulation experiments.
Custom Networks-on-Chip Architectures With Multicast Routing

In this paper, we consider the problem of synthesizing custom networks-on-chip (NoC) architectures that are optimized for a given application. We consider both unicast and multicast traffic flows in the input specification. Multicast traffic flows are used in a variety of applications, and their direct support with only replication of packets at optimal bifurcation points rather than full end-to-end replication can significantly reduce network contention and resource requirements. Our problem formulation is based on the decomposition of the problem into the inter-related steps of finding good flow partitions, deriving a good physical network topology for each group in the partition, and providing an optimized network implementation for the derived topologies. Our solutions may be comprised of multiple custom networks, each interconnecting a subset of communicating modules. We propose several algorithms that can systematically examine different flow partitions, and we propose rectilinear-Steiner-tree (RST)-based algorithms for generating efficient network topologies. Our design flow integrates floorplanning, and our solutions consider deadlock-free routing. Experimental results on a variety of NoC benchmarks showed that our synthesis results can on average achieve a 4.82 times reduction in power consumption over different mesh implementations on unicast benchmarks and a 1.92 times reduction in power consumption on multicast benchmarks. Significant improvements in performance were also achieved, with an average of 2.92 times reduction in hop count on unicast benchmarks and 1.82 times reduction in hop count on multicast benchmarks. To further gauge the effectiveness of our heuristic algorithms, we also implemented an exact algorithm that enumerates all distinct set partitions. For the benchmarks where exact results could be obtained, our algorithms on average can achieve results within 3% of exact results, but with much shorter execution times.
Age constraints for the present fault configuration in the Imperial Valley, California: Evidence for northwestward propagation of the Gulf of California Rift System

Releveling and other geophysical data for the Imperial Valley of southern California suggest the northern section of the Imperial-Brawley fault system, which includes the Mesquite Basin and Brawley Seismic Zone, is much younger than the 4 to 5 million year age of the valley itself. A minimum age of 3000 years is calculated for the northern segment of the Imperial fault from correlations between surface topography and geodetically observed seismic/interseismic vertical movements. Calculations of a maximum age of 80,000 years is based upon displacements in the crystalline basement along the Imperial fault, inferred from seismic refraction surveys. This young age supports recent interpretations of heat flow measurements, which also suggest that the current patterns of seismicity and faults in the Imperial Valley are not long lived. The current fault geometry and basement morphology suggest northwestward growth of the Imperial fault and migration of the Brawley Seismic Zone. It is suggested that this migration is a manifestation of the propagation of the Gulf of California rift system into the North American continent.
Spectral bounds for the cutoff Coulomb potential

The method of potential envelopes is used to analyse the bound-state spectrum of the Schrodinger Hamiltonian H = -Δ - v/(r + b), where v and b are positive. We established simple formulas yielding upper and lower energy bounds for all the energy Eigenvalues.
Polyhedral results for the precedence-constrained knapsack problem

Abstract A problem characteristic common to a number of important integer programming problems is that of precedence constraints: a transitive collection of constraints of the form xj ≤ xi with 0 ≤ xi ≤ 1, 0 ≤ xj ≤ 1, xi, xj integer. Precedence constraints are of interest both because they arise frequently in integer programming applications and because the convex hull of feasible integer points is the same as the region obtained by relaxing the integrality restrictions. This paper investigates the polyhedral structure of the convex hull of feasible integer points when the precedence constraints are complicated by an additional constraint or, more generally, by additional constraints defining an independence system. Sequential lifting for independence systems with precedence constraints is discussed and extensions of the cover and 1-configuration inequalities known for the knapsack polytope are presented. A general procedure for inducing facets called rooting is introduced and a variety of facets based on rooting are developed. The paper concludes by discussing a procedure for coalescing constraints related to minimal covers into facets.
Neonatal and maternal outcomes associated with elective term delivery.

Objective To quantify adverse neonatal and maternal outcomes associated with elective term delivery at less than 39 completed weeks of gestation. Study Design Prospective observational study conducted in 27 hospitals over the course of 3 months in 2007. Results Of 17,794 deliveries, 14,955 (84%) occurred at 37 weeks or greater. Of term deliveries, 6562 (44%) were planned, rather than spontaneous. Among the planned deliveries, 4645 (71%) were purely elective; 17.8% of infants delivered electively without medical indication at 37-38 weeks and 8% of those delivered electively at 38-39 weeks required admission to a newborn special care unit for an average of 4.5 days, compared with 4.6% of infants delivered at 39 weeks or beyond ( P Conclusion Elective delivery before 39 weeks' gestation is associated with significant neonatal morbidity. Initial cervical dilatation is highly correlated with cesarean delivery among women undergoing induction of labor in both nulliparous and parous women. Elective delivery before 39 completed weeks' gestation is inappropriate. Women contemplating elective induction at or beyond 39 weeks' gestation with an unfavorable cervix should be counseled regarding an increased rate of cesarean delivery.
Multilevel public funding for small business innovation: a review of US state SBIR match programs

US State governments invest in early-stage innovative activity as an economic development strategy. Nevertheless, attention directed at the public sector’s role in this capacity has been placed on federal policy actions overlooking the growing role of states. The primary aims of this paper are two-fold: (1) to articulate the motivations for multilevel public support for small business innovative activity, placing emphasis on state level incentives directed towards entrepreneurial activity; and (2) to empirically evaluate the State Match Phase I (SMP-I) program. The SMP-I program is a diffuse state level policy designed to complement the federal Small Business Innovation Research (SBIR) program by offering noncompetitive matching funds to the state’s successful SBIR Phase I recipients. This offers an opportunity to examine the marginal impact of public R&D given the state intervention. This paper employs a state and year fixed effects model and considers two outcome variables—SBIR Phase II success rates and SBIR Phase I application activity. To account for industrial heterogeneity, the data are stratified by the federal mission agencies. Results from the empirical analysis indicate that the state match increases the Phase II success rates for firms participating in the National Science Foundation SBIR program.
Robinson's landmark synthesis of tropinone

The 1917 total synthesis of tropinone by Sir Robert Robinson represents a landmark achievement in organic synthesis. Decades ahead of its time in terms of its retrosynthetic logic and biomimetic approach, the elegant combination of these two elements in this synthesis continues to serve as an inspiration for the development of new and efficient strategies for complex molecule synthesis.
An adaptively refined Cartesian mesh solver for the Euler equations

A method for adaptive refinement of a Cartesian mesh for the solution of the steady Euler equations is presented. The algorithm creates an initial uniform mesh and cuts the body out of that mesh. The mesh is then refined based on body curvature. Next, the solution is converged to a steady state using a linear reconstruction and Roe's approximate Riemann solver. Solution-adaptive refinement of the mesh is then applied to resolve high-gradient regions of the flow. The numerical results presented show the flexibility of this approach and the accuracy attainable by solution-based refinement.
Enthalpy damping for high Mach number Euler solutions

An improvement on the enthalpy damping procedure currently in use in solving supersonic flow fields is described. A correction based on entropy values is shown to produce a very efficient scheme for simulation of high Mach number three-dimensional flows. Substantial improvements in convergence rates have been achieved by incorporating this enthalpy damping scheme in a finite-volume Runge-Kutta method for solving the Euler equations. Results obtained for blended wing-body geometries at very high Mach numbers are presented.
Coulomb's Law Modification in Nonlinear and in Noncommutative Electrodynamics

We study the lowest-order modifications of the static potential for Born–Infeld electrodynamics and for the θ-expanded version of the noncommutative U(1) gauge theory, within the framework of the gauge-invariant but path-dependent variables formalism. The calculation shows a long-range correction (1/r5-type) to the Coulomb potential in Born–Infeld electrodynamics. However, the Coulomb nature of the potential (to order e2) is preserved in noncommutative electrodynamics.
Diphoton production in gluon fusion at small transverse momentum

Abstract We discuss the production of photon pairs in gluon–gluon scattering in the context of the position-space resummation formalism at small transverse momentum. We derive the remaining unknown coefficients that arise at O (α S ) , as well as the remaining O (α S 2 ) coefficient that occurs in the Sudakov factor. We comment on the impact of these coefficients on the normalization and shape of the resummed transverse momentum distribution of photon pairs, which comprise an important background to Higgs boson production at the LHC.
Quantum field theory and the Jones polynomial

It is shown that 2+1 dimensional quantum Yang-Mills theory, with an action consisting purely of the Chern-Simons term, is exactly soluble and gives a natural framework for understanding the Jones polynomial of knot theory in three dimensional terms. In this version, the Jones polynomial can be generalized fromS 3 to arbitrary three manifolds, giving invariants of three manifolds that are computable from a surgery presentation. These results shed a surprising new light on conformal field theory in 1+1 dimensions.
Supermembranes with fewer supersymmetries

Abstract The usual supermembrane solution of D = 11 supergravity interpolates between R11 and AdS4 × round R7, has symmetry P3 × SO(8) and preserves 1 2 of the spacetime supersymmetries for either orientation of the round S7. Here we show that more general supermembrane solutions may be obtained by replacing the round S7 by any seven-dimensional Einstein space M7. These have symmetry P3 × G, where G is the isometry group of M7. For example, G = SO(5) × SO(3) for the squashed S7. For one orientation of M7, they preserve N 16 spacetime supersymmetries where 1 ≤ N ≤ 8 is the number of Killing spinors on M7; for the opposite orientation they preserve no supersymmetries since then M7 has no Killing spinors. For example N = 1 for the left-squashed S7 owing to its G2 Weyl holonomy, whereas N = 0 for the right-squashed S7. All these solutions saturate the same Bogomol'nyi bound between the mass and charge. Similar replacements of SD-p-2 by Einstein spaces MD-p-2 yield new super p-brane solutions in other spacetime dimensions D ≤ 11. In particular, simultaneous dimensional reduction of the above D = 11 supermembranes on S1 leads to a new class of D = 10 elementary string solutions which also have fewer supersymmetries.
Application of Unnatural Amino Acids to the De Novo Design of Selective Antibiotic Peptides

Because of their unique mechanism of cytotoxicity against bacteria and other microorganisms, antimicrobial peptides have received a great deal of attention as possible therapeutic agents. Incorporation of unnatural amino acids into the peptide sequences has the potential to improve the organism selectivity and potency of these peptides as well as increase their metabolic stability. This protocol outlines the logic used to selectively incorporate unnatural amino acid into a peptide sequence in an attempt to obtain peptides with increased therapeutic potential as antibiotic agents.
Morphology of amorphous polymers

Abstract It has been suggested that amorphous polymers consist of small domains (30 to 100 A) in which there is local ordering or alignment of neighboring segments. Although free volume remains the primary physical parameter useful in characterizing the properties of amorphous polymers (as percent crystallinity for crystalline polymers), the distribution of the free volume, as determined by the size, interconnection, internal order, etc. of the domains is proposed to also be of importance. The paper reviews electron microscope and electron diffraction evidence for the presence of the domain structure, while also pointing out significant remaining problems.
Infrared spectra and crystal chemistry of scapolites: Implications for Martian mineralogy

Near-infrared and midinfrared spectra of a wide range of scapolite compositions were studied to determine the cause of the 2.36-μm features that have been correlated with similar features in the near-IR spectrum of Mars. We attribute the 2.36−μm features to vibrations caused by HCO3− and HSO4− in the anion sites of scapolite. The 2.36-μm absorption complex consists of four overlapping bands with the following assignments: absorptions at 2.33 and 2.35 μm are attributed to combinations of hydroxyl stretches and a O-H … O bend from HCO3−, absorptions at 2.39 and 2.41 μm are attributed to combinations of hydroxyl stretches and a O-H ··· O bend from HSO4−. The relative intensities of all four bands vary according to the HCO3−/HSO4− ratio and disordered anion site occupancy. Oriented single-crystal polarized spectra of a bicarbonate-bisulfate bearing scapolite show that the 3.9-μm hydrogen bond stretch, from HCO3−, is polarization controlled. This verifies that HCO3− is an intimate part of the scapolite crystal structure and that hydrogen in HCO3− is forming hydrogen bonds with T1 framework oxygens. The association of yellow fluorescence, attributed to S2− in the anion site, with vibrational features of HCO3− and HSO4− in the rims and fractures of scapolite grains suggests that some common geochemical process is incorporating these ions into the crystal structure during later stage alteration of scapolite. The positional disorder of HCO3− and HSO4− in the low-symmetry anion site of scapolite gives the 2.36-μm band complex a unique spectral signature not likely to be duplicated in any other mineral.
Landowner Willingness to Engage in Long-Term Timber Leases in West Virginia, USA

As global competition increases for wood-based products, the need for more efficient supply chains becomes increasingly important. In the forest products sector, these supply chains involve individuals and firms ranging from private forestland owners with standing timber to factories producing final finished products. Long-term timber leases are one mechanism that can be used to develop access to timber supplies for companies unable or unwilling to purchase land outright for growing timber. To investigate private forest owner opinions and attitudes regarding long-term timber leases, we conducted a survey of landowners from Wetzel county, West Virginia. No long-term leases were reported by respondents, but 24% claimed they would enter a lease under certain conditions. The most frequently listed concern related to long-term timber leases was for the “loss of control”. Results of this survey are discussed in the light of forest management efforts that might be used to improve the social, financial, and environmental benefits for private forest owners.
R&D Subsidies and Climate Policy: Is There a “Free Lunch”?

Because of the long-term nature of the climate problem, technological advances are often seen as an important component of any solution. However, when considering the potential for technology to help solve the climate problem, two market failures exist which lead to underinvestment in climate-friendly R&D: environmental externalities and the public goods nature of new knowledge. As a result, government subsidies to climate-friendly R&D projects are often proposed as part of a policy solution. Using the ENTICE model, I analyze the effectiveness of such subsidies, both with and without other climate policies, such as a carbon tax. While R&D subsidies do lead to significant increases in climate-friendly R&D, this R&D has little impact on the climate itself. Subsidies address the problem of knowledge as a public good, but they do not address the environmental externality, and thus offer no additional incentive to adopt new technologies. Moreover, high opportunity costs to R&D limit the potential role that subsidies can play. While R&D subsidies can improve efficiency, policies that directly affect the environmental externality have a much larger impact on both atmospheric temperature and economic welfare.
Fluorescence spectroscopy and imaging for noninvasive diagnostics: applications to early cancer detection in the lung

Tissue fluorescence spectroscopy and imaging are being investigated as potential methods for non-invasive detection of pre-neoplastic change in the lung and other organ systems. A substantial contribution to tissue fluorescence is known to arise from endogenous cellular fluorophores. Using steady-state and time-resolved fluorescence spectroscopy and imaging, we characterized the endogenous fluorescence properties of immortalized and carcinogen transformed human bronchial epithelial cells. Non-invasive sensing of endogenous molecular biomarkers associated with human bronchial pre-neoplasia will be discussed.
Towards a Definition of an Algorithm

We define an algorithm to be the set of programs that implement or express that algorithm. The set of all programs is partitioned into equivalence classes. Two programs are equivalent if they are essentially the same program. The set of equivalence classes forms the category of algorithms. Although the set of programs does not even form a category, the set of algorithms form a category with extra structure. The conditions we give that describe when two programs are essentially the same turn out to be coherence relations that enrich the category of algorithms with extra structure. Universal properties of the category of algorithms are proved.
Episodic X-Ray Emission Accompanying the Activation of an Eruptive Prominence: Evidence of Episodic Magnetic Reconnection

We present an X-ray imaging and spectroscopic study of a partially occulted (N16W93) C7.7 flare on 2003 April 24 observed by Reuven Ramaty High Energy Solar Spectroscopy Imager that accompanied a prominence eruption observed by Transition Region and Coronal Explorer. (1) The activation and rise of the prominence occurs during the preheating phase of the flare. The initial X-ray emission appears as a single coronal source at one leg of the prominence and it then splits into a double source. Such a source splitting happens three times, each coinciding with an increased X-ray flux and plasma temperature, suggestive of fast reconnection in a localized current sheet and an enhanced energy-release rate. In the late stage of this phase, the prominence displays a helical structure. These observations are consistent with the tether-cutting and/or kink-instability model for triggering solar eruptions. (2) The eruption of the prominence takes place during the flare impulsive phase. Since then, there appear signatures predicted by the classical model of two-ribbon flares occurring in a vertical current sheet trailing an eruption. These signatures include an extreme-ultraviolet (EUV) cusp and current-sheet-like feature (or ridge) above it. There is also X-ray emission along the EUV ridge both below and above the cusp, which in both regions appears closer to the cusp at higher energies in the thermal regime (20 keV). This trend is reversed in the nonthermal regime. (3) Spectral analysis indicates thermal X-rays from all sources throughout the flare, while during the impulsive phase there is additional nonthermal emission which primarily comes from the coronal source below the cusp. This source also has a lower temperature (T = 20 ? 1 vs. 25 ? 1 MK), a higher emission measure (EM = (3.3 ? 0.4) vs. (1.2 ? 0.4) ? 1047 cm?3), and a harder nonthermal spectrum (electron power-law index ? = 5.4 ? 0.4 vs. 8 ? 1) than the upper sources.
The synthesis of disperse and cationic dyes from acid dye structures

Abstract This paper is concerned with the conversion of some mono- and di-sulfonated naphthol azo dyes to disperse dyes suitable for poly(ethyleneterephthalate) fibers, and cationic dyes for cationic dyeable polyester and acrylic fibers. The chemical structure of these new dyes has been confirmed by 1H-NMR, FAB or DCI mass spectrometry, and in some cases by elemental analysis. Some fastness properties and absorption spectral data of both types of dyes are also reported, as well as an interesting limitation in the naphthalene-based acid dyes suitable for the described conversion.
A stereoselective concise synthesis of C2- and meso-aminodiols from (R)-phenylglycinol

Abstract Oxazolidines derived from (R)-phenylglycinol can undergo diastereoselective vinyl- and aryl addition to give, after oxidative cleavage, meso- and C 2 -diethanol amines.
One dimensional hydrodynamics of asteroid-neutron star collisions

Results are presented of simplified one-dimensional hydrodynamic-radiation diffusion calculations of the tidal breakup of a solid body approaching a neutron star in central impact. (GHT)
Vortex Shedding From Struts in an Annular Exhaust Diffuser

Results from scale-model experiments and industrial gas turbine tests show that strut vortex shedding in an annular exhaust diffuser can effectively be modified by adding tapered chord to the struts. The struts are bluff bodies at full-speed, no-load conditions, when inlet swirl is close to 60 deg. Data from wind tunnel tests show that wake Strouhal number is 0.47, larger than that expected for an isolated cylinder wake. This value of Strouhal number agrees with those measured in full-scale exhaust diffusers. Wind tunnel tests showed that a strut with tapered chord most effectively reduced wake amplitudes and shifted shedding frequency. The tapered strut was also effective in reducing shedding amplitude in a scale-model diffuser. Finally, gas turbine tests employing a tapered strut showed significant reductions in unsteady pressure and noise. A major benefit of strut taper is a reduction of noise by uncoupling of vortex shedding from acoustic resonant response.
Crop Insurance Savings Accounts: A Viable Alternative to Crop Insurance?

This research explores the viability of an alternative design for crop insurance based upon farmer-owned savings accounts that are regulated, monitored, and marginally assisted by the government. Such accounts could be an effective risk management tool for many farmers and could operate without major government subsidization. Relative to the current program, the proposed design should exhibit minimal moral hazard and adverse selection problems, and since farm-level risk does not have to be priced, the proposed design eliminates the premium rating difficulties that weaken actuarial soundness and trigger the need for substantial external subsidies. In addition, administrative costs should be considerably lower.
The Effects of Licensing on the Wages of Radiologic Technologists

We analyze the effect that state licensing of radiologic technologists (RTs) has had upon RT wages with a unique dataset that allows us to control for place of work and job specialization. Using OLS and several measures of licensing, we find evidence that RTs working in states with licensing statutes earn as much as 3.3% more than RTs working in states without licensing. When we control for endogeneity using instrumental variables (IV) estimation, our estimate of the licensing premium doubles (6.9%). Our results provide further support for existing theories of the effects of occupational licensing on the wages of practitioners.
Critical Role of Smad and AP-1 Complexes in TGF-β-Dependent Apoptosis.

INTRODUCTION. Transforming growth factor-β1 (TGF-β1) induces not only cell growth inhibition but also apoptosis in hepatocytes, myeloid cells, and epithelial cells. Smad complexes (Smad2-Smad4 and Smad3-Smad4) are identified as key signaling molecules which transmit TGF-β1 signal for growth inhibition from the TGF-β receptors to the nucleus (1, 2). However, their roles are unclear in the induction of apoptosis. Our results show here that both Smad and AP-1 complexes play a critical role in TGF-β1 signaling for apoptosis.
What is a virtual link

Several authors have recently studied virtual knots and links because they admit invariants arising from R-matrices. We prove that every virtual link is uniquely represented by a link L SI in a thickened, compact, oriented surface S such that the link complement (SI)nL has no essential vertical cylinder. AMS Classication 57M25; 57M27 57M15
Human β-galactoside α-2,3-sialyltransferase (ST3Gal III) attenuated Taxol-induced apoptosis in ovarian cancer cells by downregulating caspase-8 activity

Taxol triggers apoptosis in a variety of cancer cells, but it also upregulates cytoprotective proteins and/or pathways that compromise its therapeutic efficacy. In this report, we found that Taxol treatment resulted in caspase-8-dependent apoptosis in SKOV3 human ovarian cancer cells. Moreover, Taxol-induced apoptosis was associated with caspase-3 activation. Interestingly, Taxol treatment upregulated α-2,3-sialyltransferase (ST3Gal III) expression and forced expression of ST3Gal III attenuated Taxol-induced apoptosis. Furthermore, ST3Gal III overexpression inhibited Taxol-triggered caspase-8 activation, indicating that ST3Gal III upregulation produces cellular resistance to Taxol and hence reduces the efficacy of Taxol therapy.