cssi/SciSciGPT-SciSciNet huggingface dataset:
A Transmission Electron Microscopy Study of Presolar Hibonite

We report isotopic and microstructural data on five presolar hibonite grains (KH1, KH2, KH6, KH15, and KH21) identified in an acid residue of the Krymka LL3.1 ordinary chondrite. Isotopic measurements by secondary ion mass spectrometry (SIMS) verified a presolar circumstellar origin for the grains. Transmission electron microscopy (TEM) examination of the crystal structure and chemistry of the grains was enabled by in situ sectioning and lift-out with a focused-ion-beam scanning-electron microscope (FIB-SEM). Comparisons of isotopic compositions with models indicate that four of the five grains formed in low-mass stars that evolved through the red giant/asymptotic giant branches (RGBs/AGBs), whereas one grain formed in the ejecta of a Type II supernova. Selected-area electron-diffraction patterns show that all grains are single crystals of hibonite. Some grains contain minor structural perturbations (stacking faults) and small spreads in orientation that can be attributed to a combination of growth defects and mechanical processing by grain-grain collisions. The similar structure of the supernova grain to those from RGB/AGB stars indicates a similarity in the formation conditions. Radiation damage (e.g., point defects), if present, occurs below our detection limit. Of the five grains we studied, only one has the pure hibonite composition of CaAl{sub 12}O{sub 19}. Allmore » others contain minor amounts of Mg, Si, Ti, and Fe. The microstructural data are generally consistent with theoretical predictions, which constrain the circumstellar condensation temperature to a range of 1480-1743 K, assuming a corresponding total gas pressure between 1 x 10{sup -6} and 1 x 10{sup -3} atm. The TEM data were also used to develop a calibration for SIMS determination of Ti contents in oxide grains. Grains with extreme {sup 18}O depletions, indicating deep mixing has occurred in their parent AGB stars, are slightly Ti enriched compared with grains from stars without deep mixing, most likely reflecting differences in grain condensation conditions.« less
Novel unsymmetric chiral Schiff bases possessing two different donor moieties: unique tetradentate ligands from combination of salicylaldehyde and acetylacetone units

Abstract A new class of novel chiral Schiff base ligands has been developed using a stepwise approach. The key feature of these new ligands is that they possess two different donor units, one of them is aromatic while the other is non-aromatic.
Isogenies of abelian varieties over finite fields

In this paper we give conditions under which two abelian varieties that are defined over a finite field $$F$$F, and are isogenous over some larger field, are $$F$$F-isogenous. Further, we give conditions under which a given isogeny is defined over $$F$$F.
Ionospheric research from space vehicles.

Previous to the advent of artificial satellites, our knowledge of the ionosphere was limited principally to the interpretation of data from the classical ground-based ionosonde and a few rocket measurements of ionizing radiation, electron density and ion composition, all applicable to altitudes below the F2 peak. The early rocket results of Seddon and Jackson (1958) which have been summarized by Ratcliffe and Weekes (1960), show that the lower ionosphere is characterized by an electron density which increases monotonically with altitude and thus that the term “layer” is an incorrect nomenclature for the D-, E-, and F-regions. In more recent years, a wealth of data has been gathered on the temporal, spatial and energy distribution of the charged particles for the ionosphere. This has been accomplished at previously relatively unexplored altitudes well above the F2 peak. Concurrently but unfortunately not simultaneously, measurements have been made of the time dependence of corpuscular, ultraviolet and X-radiation. The most serious observational gap is in the structure of the neutral atmosphere where the most significant contribution has been the computation of the neutral density parameter from satellite drag observations.
A Methodology for Robust Multiproxy Paleoclimate Reconstructions and Modeling of Temperature Conditional Quantiles

Great strides have been made in the field of reconstructing past temperatures based on models relating temperature to temperature-sensitive paleoclimate proxies. One of the goals of such reconstructions is to assess if current climate is anomalous in a millennial context. These regression-based approaches model the conditional mean of the temperature distribution as a function of paleoclimate proxies (or vice versa). Some of the recent focus in the area has considered methods that help reduce the uncertainty inherent in such statistical paleoclimate reconstructions, with the ultimate goal of improving the confidence that can be attached to such endeavors. A second important scientific focus in the subject area is the area of forward models for proxies, the goal of which is to understand the way paleoclimate proxies are driven by temperature and other environmental variables. One of the primary contributions of this article is novel statistical methodology for (i) quantile regression (QR) with autoregressi...
Moral hazard, imperfect risk-sharing, and the behavior of asset returns

Abstract This paper develops a model of endogenous idiosyncratic risk in a simple two-period general equilibrium setting, and examines its implications for the behavior of asset returns. The model readily generates empirically plausible idiosyncratic risk in consumption and yields more realistic behavior of asset returns than comparable models with perfect insurance. The most dramatic effects of imperfect risk-sharing, however, are not on the spreads between asset returns but on their absolute levels. Overall the results suggest allowing for incomplete markets can contribute to a resolution of the equity premium puzzle.
Diffraction properties of fixed gratings in photorefractive media

The diffraction properties of fixed volume gratings, including the effect of additional photorefractive energy coupling between the incident wave and the diffracted wave, are considered. Both transmission gratings and reflection gratings are treated. Analytical solutions for phase gratings are derived, and numerical solutions for absorption gratings are also obtained. The results are presented and discussed.
Vive La Différence: Paxos vs. Viewstamped Replication vs. Zab

Paxos, Viewstamped Replication, and Zab are replication protocols for high-availability in asynchronous environments with crash failures. Claims have been made about their similarities and differences. But how does one determine whether two protocols are the same, and if not, how significant are the differences? We address these questions using refinement mappings. Protocols are expressed as succinct specifications that are progressively refined to executable implementations. Doing so enables a principled understanding of the correctness of design decisions for implementing the protocols. Additionally, differences that have a significant impact on performance are surfaced by this exercise.
A Comparison of Methods of Repairing the Symphysis Pubis in Bladder Exstrophy by Tensile Testing

Objective To compare the efficacy of several fixation techniques in the reconstruction of diastasis of the symphysis pubis in bladder exstrophy. Materials and methods The symphyses of 32 pelves removed from piglets about 1 month old were disrupted and repaired using one of eight methods. After repair, each pelvis was tested biomechanically for load-to-failure, stiffness and energy-to-failure. The various repair techniques were compared with one another and to a group of six pelves tested intact. Results Four of the methods tested, including a #2 nylon suture placed through bone in a horizontal mattress arrangement, several loops of #2 nylon suture tied around the pubes, Mersilene tape tied around the pubes, and Mitek G-II suture anchors placed into the superior pubic rami, showed the highest stiffness and load-to-failure. All methods were very weak compared with the intact symphysis; the best load-to-failure (#2 nylon horizontal mattress suture) was less than half of that for intact bone, and the best stiffness (mersilene tape) was less than one-third that for the intact symphysis. Conclusion The repairs varied greatly in the variables tested and those which are most promising merit further investigation to assess methods of improving their performance.
The polyubiquitin gene Ubi-p63E is essential for male meiotic cell cycle progression and germ cell differentiation in Drosophila

The ubiquitin proteasome system (UPS) regulates many biological pathways by post-translationally ubiquitylating proteins for degradation. Although maintaining a dynamic balance between free ubiquitin and ubiquitylated proteins is key to UPS function, the mechanisms that regulate ubiquitin homeostasis in different tissues through development are not clear. Here we show, via analysis of the magellan (magn) complementation group, that loss of function of the Drosophila polyubiquitin Ubi-p63E results specifically in meiotic arrest sterility in males. Ubi-p63E contributes predominantly to maintaining the free ubiquitin pool in testes. The function of Ubi-p63E is required cell-autonomously for proper meiotic chromatin condensation, cell cycle progression and spermatid differentiation. magn mutant germ cells develop normally to the spermatocyte stage but arrest at the G2/M transition of meiosis I, with lack of protein expression of the key meiotic cell cycle regulators Boule and Cyclin B. Loss of Ubi-p63E function did not strongly affect the spermatocyte transcription program regulated by the testis TBP-associated factor (tTAF) or meiosis arrest complex (tMAC) genes. Knocking down proteasome function specifically in spermatocytes caused a different meiotic arrest phenotype, suggesting that the magn phenotype might not result from general defects in protein degradation. Our results suggest a conserved role of polyubiquitin genes in male meiosis and a potential mechanism leading to meiosis I maturation arrest.
On the geometric interpretation of N=2 superconformal theories

Abstract We clarify certain important issues relevant for the geometric interpretation of a large class of N= 2 superconformal theories. By fully exploiting the phase structure of these theories (discovered in earlier works) we are able to clearly identify their geometric content. One application is to present a simple and natural resolution to the question of what constitutes the mirror of a rigid Calabi-Yau manifold. We also discuss some other models with unusual phase diagrams that highlight some subtle features regarding the geometric content of conformal theories.
Simulating a Random Walk with Constant Error

We analyse Jim Propp's $P$-machine, a simple deterministic process that simulates a random walk on ${\mathbb Z}^d$ to within a constant. The proof of the error bound relies on several estimates in the theory of simple random walks and some careful summing. We mention three intriguing conjectures concerning sign-changes and unimodality of functions in the linear span of $\{p(\cdot,{\bf x}) : {\bf x} \in {\mathbb Z}^d\}$, where $p(n,{\bf x})$ is the probability that a walk beginning from the origin arrives at ${\bf x}$ at time $n$.
A Riemann-Hilbert approach to some theorems on Toeplitz operators and orthogonal polynomials

In this paper, the authors show how to use Riemann-Hilbert techniques to prove various results, some old, some new, in the theory of Toeplitz operators and orthogonal polynomials on the unit circle (OPUCs). There are four main results: the first concerns the approximation of the inverse of a Toeplitz operator by the inverses of its finite truncations. The second concerns a new proof of the 'hard' part of Baxter's theorem, and the third concerns the Born approximation for a scattering problem on the lattice Z"+. The fourth and final result concerns a basic proposition of Golinskii-Ibragimov arising in their analysis of the Strong Szego Limit Theorem.
Propagation through endogenous investment-specific technological change

Abstract Many real business cycle models lack a significant propagation mechanism. Consequently, most of the serial correlation in output is inherited from the serial correlation in the exogenous shocks. A simple model is presented to show there need not be any relationship between the serial correlation of the exogenous shocks, and that of output. This is accomplished by incorporating the well-documented fact that research spending has generated changes in the real price of capital.
The control theory of motion-based communication: Problems in teaching robots to dance

The paper describes results on two components of a research program focused on motion-based communication mediated by the dynamics of a control system. Specifically we are interested in how mobile agents engaged in a shared activity such as dance can use motion as a medium for transmitting certain types of messages. The first part of the paper adopts the terminology of motion description languages and deconstructs an elementary form of the well-known popular dance, Salsa, in terms of four motion primitives (dance steps). Several notions of dance complexity are introduced. We describe an experiment in which ten performances by an actual pair of dancers are evaluated by judges and then compared in terms of proposed complexity metrics. An energy metric is also defined. Values of this metric are obtained by summing the lengths of motion segments executed by wheeled robots replicating the movements of the human dancers in each of the ten dance performances. Of all the metrics that are considered in this experiment, energy is the most closely correlated with the human judges' assessments of performance quality. The second part of the paper poses a general class of dual objective motion control problems in which a primary objective (artistic execution of a dance step or efficient movement toward a specified terminal state) is combined with a communication objective. Solutions of varying degrees of explicitness can be given in several classes of problems of communicating through the dynamics of finite dimensional linear control systems. In this setting it is shown that the cost of adding a communication component to motions that steer a system between prescribed pairs of states is independent of those states. At the same time, the optimal encoding problem itself is shown to be a problem of packing geometric objects, and it remains open. Current research is aimed at solving such communication-through-action problems in the context of the motion control of mobile robots.
The tuning of heterocyclic isomerization: additional routes to extended donors

Tetrathianaphthalene: A precursor easily synthesized in bulk, is utilized in the synthesis of tetrathiafulvalene, and extended chalcogenated tetrathianaphthalenes and tetrathiafulvalenes. The donor syntheses dependant upon core heterocycle configuration retention or isomerization are controlled via the use of novel solvent systems and new classes of disulfide building blocks.
Effect of Prehydrolysis on the Textural and Catalytic Properties of Titania-Silica Aerogels

Abstract When applied to the preparation of mixed oxides, sol-gel chemistry affords considerable control over the extent of component mixing: well-mixed oxides result from a preparation in which precursor reactivities are evenly matched. In this work, we describe the preparation and characterization of two sets of mixed titania-silica aerogels covering the entire composition range, one set prepared using prehydrolysis of the silicon precursor to promote homogeneous component mixing and a second set prepared without prehydrolysis. Compared to the prehydrolyzed mixed aerogels, samples prepared without prehydrolysis of the silicon precursor exhibit low 1-butene isomerization activities, low acid site densities, and low fractional Bronsted site populations. These results suggest that the silica and titania components are segregated in the nonprehydrolyzed samples, with inactive silica-rich clusters obscuring much of the surface of a titania-enriched "core." The dependence of important catalytic properties upon composition and homogeneity are explained in terms of the relative number and location of M-O-M′ (cation-oxygen-cation) linkages that exist in a given sample.
Non-perturbative renormalisation with domain wall fermions

Abstract We present results from a study of the renormalisation of both quark bilinear and four-quark operators for the domain wall fermion action, using the non-perturbative renormalisation technique of the Rome-Southampton group. These results are from a quenched simulation, on a 16 3 × 32 lattice, with β = 6.0 and L s = 16.
Infrared renormalization in non-relativistic QED and scaling criticality

Abstract We consider a spin- 1 2 electron in the framework of non-relativistic Quantum Electrodynamics (QED). Let H ( p → , σ ) denote the fiber Hamiltonian corresponding to the conserved total momentum p → ∈ R 3 of the electron and the photon field, regularized by a fixed ultraviolet cutoff in the interaction term, and an infrared regularization parametrized by 0 σ ≪ 1 . Ultimately, our goal is to remove the latter by taking σ ↘ 0 . We prove that there exists a constant 0 α 0 ≪ 1 independent of σ > 0 such that for all | p → | 1 3 and all values of the finestructure constant 0 α α 0 , there exists a ground state eigenvalue of multiplicity two at the bottom of the essential spectrum. Moreover, we prove that the renormalized electron mass satisfies 1 m ren ( p → , σ ) 1 + c α , uniformly in σ ⩾ 0 , in units where the bare mass has the value 1, and we prove the existence of the renormalized mass in the limit σ ↘ 0 . Our analysis uses the isospectral renormalization group method of Bach, Frohlich, Sigal introduced in [V. Bach, J. Frohlich, I.M. Sigal, Quantum electrodynamics of confined non-relativistic particles, Adv. Math. 137 (2) (1998) 299–395; V. Bach, J. Frohlich, I.M. Sigal, Renormalization group analysis of spectral problems in quantum field theory, Adv. Math. 137 (1998) 205–298] and further developed in [V. Bach, T. Chen, J. Frohlich, I.M. Sigal, Smooth Feshbach map and operator-theoretic renormalization group methods, J. Funct. Anal. 203 (1) (2003) 44–92; V. Bach, T. Chen, J. Frohlich, I.M. Sigal, The renormalized electron mass in non-relativistic QED, J. Funct. Anal. 243 (2) (2007) 426–535]. The limit σ ↘ 0 determines a scaling-critical (or endpoint type) renormalization group problem, in which the interaction is strictly marginal (of scale-independent size). A main result of this paper is the development of a method that provides rigorous control of the renormalization of a strictly marginal quantum field theory characterized by a non-trivial scaling limit. The key ingredients entering this analysis include a hierarchy of exact algebraic cancelation identities exploiting the spatial and gauge symmetries of the model, and a combination of the isospectral renormalization group method with the strong induction principle.
Data clustering: 50 years beyond K-means

Organizing data into sensible groupings is one of the most fundamental modes of understanding and learning. As an example, a common scheme of scientific classification puts organisms into a system of ranked taxa: domain, kingdom, phylum, class, etc. Cluster analysis is the formal study of methods and algorithms for grouping, or clustering, objects according to measured or perceived intrinsic characteristics or similarity. Cluster analysis does not use category labels that tag objects with prior identifiers, i.e., class labels. The absence of category information distinguishes data clustering (unsupervised learning) from classification or discriminant analysis (supervised learning). The aim of clustering is to find structure in data and is therefore exploratory in nature. Clustering has a long and rich history in a variety of scientific fields. One of the most popular and simple clustering algorithms, K-means, was first published in 1955. In spite of the fact that K-means was proposed over 50 years ago and thousands of clustering algorithms have been published since then, K-means is still widely used. This speaks to the difficulty in designing a general purpose clustering algorithm and the ill-posed problem of clustering. We provide a brief overview of clustering, summarize well known clustering methods, discuss the major challenges and key issues in designing clustering algorithms, and point out some of the emerging and useful research directions, including semi-supervised clustering, ensemble clustering, simultaneous feature selection during data clustering, and large scale data clustering.
Structure and mobility of cyclohexane as a solvent for trans-polyisoprene

Solutions of trans–polyisoprene in cyclohexane are investigated in atomistic detail at different compositions at two different temperatures. We investigate the influence of polymer concentration on the dynamics of the solvent molecules and the structure of the solvation shell. The double bonds along the polymer backbone are preferentially approached by the solvent molecules. The mobility of cyclohexane molecules decreases with increasing polymer concentration in ambient conditions. The reorientation of molecules becomes more anisotropic with concentration as the polymer hinders the reorientation of the molecular plane. At elevated temperatures the influence of the polymer is weaker and the reorientation of the solvent is more isotropic. Additionally, a fast and efficient way to set up atomistic simulations is shown in detail in which the initial simulations increase in length and in the simulation time-step. The excess energy from initial overlaps is removed by resetting the velocities at regular intervals.
On the symmetries of equilibrium stellar models

The equilibrium states of isolated self-gravitating fluids (i.e. stellar models) always have a high degree of spatial symmetry. This paper reviews the current understanding of these symmetries in both the newtonian and the general relativistic theories. The arguments that establish (under various appropriate conditions) the necessity of spherical symmetry, axisymmetry, and reflection symmetry are summarized. The limitations of the present results and suggestions for further progress are outlined in the concluding remarks.
A Report On the "International Academic Conference On Religion," Beijing, April 6-10, 1992

The International Association for the History of Religions (1AHR) was especially pleased to hold a conference for the first time in China—the second time in Asia (as an IAHR International Congress was held in Tokyo in 1958). The IAHR aims to be a truly international organization and has been very supportive in recent years of the nascent discipline of Religious Studies in the People's Republic of China (PRC). In this report, I would like to introduce the conference's organizers and participants, its academic content, and its overall nature.
A multiple criteria decision making approach for the assembly line balancing problem

In practice, measuring total profit for a given assembly line balancing (ALB) problem is an involved process that is sometimes impossible because of much uncertainty and unavailability of data. In this paper, ALB is formulated as a multiple criteria problem where several easily quantifiable criteria (objectives) and constraints are defined. Objective functions include number of stations, cycle time, and operations cost, all to be minimized. After a discussion of applications and an overview of multiple criteria decision making (MCDM) approaches for ALB, the MCDM-ALB problem is formulated. Basic definitions and properties of MCDM for ALB are outlined and then an interactive MCDM approach is developed for solving the MCDM-ALB problem. To solve the problem, the decision maker (DM) interactively responds to paired comparisons of multicriteria alternatives. Through a limited number of interactions with the DM, the most preferred alternative is obtained. Many unexplored alternatives are eliminated by using a on...
Confirmation of the 62 Day X-Ray Periodicity from M82

Using 400 days of new X-ray monitoring of M82, we confirm the 62 day periodicity previously reported. In the full data set spanning 1124 days, we find a period of 62.0 ± 0.3 days and a coherence, Q = 22.3, that is consistent with a strictly periodic signal. We estimate that the probability of chance occurrence of our observed signal is 6 × 10-7. The light curve folded at this period is roughly sinusoidal and has a peak-to-peak amplitude of (0.99 ± 0.10) × 10-11 erg cm-2 s-1. Confirmation of the periodicity strengthens our previous suggestion that the 62 day modulation is due to orbital motion within an X-ray binary.
On the energy saved by interlayer interactions in the superconducting state of cuprates

A Ginzburg-Landau–like functional is proposed reproducing the main low-energy features of various possible high-Tc superconducting mechanisms involving energy savings due to interlayer interactions. The functional may be used to relate these savings to experimental quantities. Two examples are given, involving the mean-field specific-heat jump at Tc and the superconducting fluctuations above Tc. Comparison with existing data suggests, e.g., that the increase of Tc due to the so-called interlayer tunneling (ILT) mechanism of interlayer kinetic-energy savings is negligible in optimally doped Bi2Sr2CaCu2O8 + x.
A Generic Surface Sampler for Monte Carlo Simulations

We present a Monte Carlo algorithm that generates points randomly and uniformly on a set of arbitrary surfaces. The algorithm is completely general and only requires the geometry modeling software to provide the intersection points of an arbitrary line with the surface being sampled. We demonstrate the algorithm using the Geant4 Monte Carlo simulation toolkit. The efficiency of the sampling algorithm is discussed, along with various options in the implementation and example applications.
Characteristics of Solar Flare Doppler-Shift Oscillations Observed with the Bragg Crystal Spectrometer on Yohkoh

This paper reports the results of a survey of Doppler-shift oscillations measured during solar flares in emission lines of S XV and Ca XIX with the Bragg Crystal Spectrometer (BCS) on Yohkoh. Data from 20 flares that show oscillatory behavior in the measured Doppler shifts have been fitted to determine the properties of the oscillations. Results from both BCS channels show average oscillation periods of 5.5 ± 2.7 minutes, decay times of 5.0 ± 2.5 minutes, amplitudes of 17.1 ± 17.0 km s-1, and inferred displacements of 1070 ± 1710 km, where the listed errors are the standard deviations of the sample means. For some of the flares, intensity fluctuations are also observed. These lag the Doppler-shift oscillations by 1/4 period, strongly suggesting that the oscillations are standing slow-mode waves. The relationship between the oscillation period and the decay time is consistent with conductive damping of the oscillations.
Mean-field bounds and correlation inequalities

I prove a new correlation inequality for a class ofN-component classical ferromagnets (1⩽N⩽4). This inequality implies that the correlation functions decay exponentially and the spontaneous magnetization is zero, above the mean-field critical temperature.
Extrasolar Trojans: The Viability and Detectability of Planets in the 1:1 Resonance

We explore the possibility that extrasolar planets might be found in the 1 : 1 mean motion resonance, in which a pair of planets share a time-averaged orbital period. There are a variety of stable co-orbital configurations, and we specifically examine three different versions of the 1 : 1 resonance. In the first configuration, the two planets and the star participate in tadpole-type librations about the vertices of an equilateral triangle. The dynamics of this situation resemble the orbits of Jupiter's Trojan asteroids. We show analytically that an equilateral configuration consisting of a star and two equal-mass planets is linearly stable for mass ratios μ = 2mpl/(2mpl + M*) < 0.03812. When the equilateral configuration is subjected to larger perturbations, a related 1 : 1 resonance occurs. In this second family of configurations, the planet pair executes horseshoe-type orbits in which the librating motion in the corotating frame is symmetric about a 180° separation. The Saturnian satellites Janus and Epimetheus provide a solar system example of this phenomenon. In the case of equal-mass planets, a numerical survey indicates that horseshoe configurations are stable over long periods for mass ratios μ < 0.0004, indicating that a pair of Saturn-mass planets can exist in this resonance. The third configuration that we examine is more exotic and involves a pair of planets that exchange angular momentum in a manner that allows them to indefinitely avoid close encounters. An illustrative example of this resonance occurs when one planet has a highly eccentric orbit while the other planet moves on a nearly circular orbit; the periapses are in alignment, and conjunctions occur near periapse. All three of these resonant configurations can be stable over timescales comparable to or longer than stellar lifetimes. We show that pairs of planets in 1 : 1 resonance yield characteristic radial velocity signatures that are not prone to the sin i degeneracy. Indeed, Keplerian fits to the radial velocities cannot reveal the presence of two planets in the 1 : 1 resonance. We discuss a dynamical fitting method for such systems and illustrate its use with a simulated data set. Finally, we argue that hydrodynamic simulations and torqued three-body simulations indicate that 1 : 1 resonant pairs might readily form and migrate within protostellar disks.
Regioselectivity in nickel(0)/phosphine catalyzed cycloadditions of alkynes and isocyanates

Abstract The regioselectivity of Ni(0)-catalyzed cycloadditions of various isocyanates and asymmetrical alkynes to afford pyridones was explored. The use of PEt 3 provided, in most cases, two of the four possible pyridone regioisomers in high overall yields. Mechanistic rationale for the product distribution is provided.
Implications of a Modified Higgs to Diphoton Decay Width

Motivated by recent results from Higgs searches at the Large Hadron Collider, we consider possibilities to enhance the diphoton decay width of the Higgs boson over the Standard Model expectation, without modifying either its production rate or the partial widths in the WW and ZZ channels. Studying effects of new charged scalars, fermions and vector bosons, we find that significant variations in the diphoton width may be possible if the new particles have light masses of the order of a few hundred GeV and sizeable couplings to the Higgs boson. Such couplings could arise naturally if there is large mass mixing between two charged particles that is induced by the Higgs vacuum expectation value. In addition, there is generically also a shift in the Zγ partial width, which in the case of new vector bosons tends to be of similar magnitude as the shift in the diphoton partial width, but smaller in other cases. Therefore simultaneous measurements in these two channels could reveal properties of new charged particles at the electroweak scale.
The Weyl Quantization and the Quantum Group Quantization of the Moduli Space of Flat SU(2)-Connections on the Torus are the Same

We prove that, for the moduli space of flat SU(2)-connections on the 2-dimensional torus, the Weyl quantization and the quantization performed using the quantum group of SL(2,C) are the same. This is done by comparing the matrices of the operators associated through the two quantizations to cosine functions. We also discuss the *-product of the Weyl quantization and show that it satisfies the product-to-sum formula for noncommutative cosines on the noncommutative torus.
Reactions of N-chloro β-lactams

Abstract N -Chloro β-lactam 4 was prepared to explore its potential for a methoxy transfer to the C3 position of the β-lactam. Methoxy addition to C3 of β-lactam 4 with concomitant loss of chloride to give α-methoxy β-lactam 5 occurred under mild alkaline conditions but was accompanied by methanolysis of the β-lactam ring as the major reaction pathway. Reaction of 4 with AgNO 3 promoted methoxy addition to C4 of the β-lactam followed by subsequent reactions.
HIV Infection in Women

Abstract Human immunodeficiency virus (HIV) infection is caused by an RNA retrovirus that is trophic for CD 4 lymphocytes. By attacking and ultimately destroying these cells, the virus causes a severe deficiency in cell-mediated immunity, rendering the host susceptible to a myriad of opportunistic infections and malignancies. HIV infection occurs in a continuum, ranging from the initial, acute retroviral illness to florid acquired immunodeficiency syndrome (AIDS). At the present time, more than 500,000 Americans have been afflicted with AIDS. More than one million Americans are in pre-AIDS stages of their illness. In the United States, 15 to 20% of patients with HIV infection are women. Among women, the two most important risk factors for infection are IV drug use and heterosexual contact with a high-risk male. Factors that increase the risk of sexual transmission of HIV infection include multiple partners, receptive anal intercourse, concurrent use of IV drugs or crack cocaine, other STDs, intercourse during menses or in the presence of ulcerative genital lesions, and contact with an uncircumcised male. More than 90% of all cases of HIV infection in children result from direct perinatal transmission from an infected mother. Transplacental dissemination and intrapartum transmission are the two most important mechanisms of perinatal infection. HIV infection can also be transmitted by breastfeeding and by close personal contact following delivery. The risk of vertical transmission can be reduced significantly by treating HIV-infected patients and their neonates with antiviral chemotherapy. Because HIV infection is such a severe, and usually, fatal illness, great emphasis should be placed on preventive measures. Mental health professionals can play a pivotal role in the management of HIV-infected patients, particularly in helping them cope with the terminal stages of their illness.
Impact of prototyping resource environments and timing of awareness of constraints on idea generation in product design

Abstract Research and development laboratories in universities and firms around the world try to maximize innovation with a limited set of resources. However, questions remain about the influence of resource constraints on idea generation in early-stage product design. Multiple embedded case studies were conducted with engineering students and faculty at two university campuses in Mexico. Students developed sketches for products that would satisfy an open-ended design problem in a constrained-resource setting, where the variables were the timing of when information about these constraints was revealed, and the regular prototyping environment of the student. The evidence suggests that the timing of awareness of constraints can have an impact on design outcomes, but that this effect varies depending on the designer's regular prototyping resource environment.
Diastereoselective Chelation-Controlled Additions to β-Silyloxy Aldehydes

A general diastereoselective method for the addition of dialkylzincs and (E)-di- and (E)-trisubstituted vinylzinc reagents to β-silyloxy aldehydes is presented. This method employs alkyl zinc triflate and nonaflate Lewis acids and affords chelation-controlled products (6:1 to > 20:1 dr).
When product designers use perceptually based color tools

Palette synthesis and analysis tools have been built based upon a model of color experience. This model adjusts formal compositional elements such as hue, value, chroma, and their contrasts, as well as size and proportion. Clothing and household product designers were given these tools to guide their selection of seasonal palettes in the production of the private-label merchandise in a large retail chain. The designers chose base palettes. Accents to these palettes were generated with and without the aid of the color tools. These palettes are compared by using perceptual metrics and interviews. The results are presented.
Dynamic Load Estimation for Heavy Trucks on Bridge Structures

As part of a system for structural health monitoring, it is required to determine the spatial and temporal distributions of vertical loads arising from heavy trucks driven on flexible bridge structures. An instrumented truck is used to generate the input loads and estimate the load time histories. The truck can carry a range of sensors; however direct measurement of vertical tire loads between the tires and the structure is not considered realistic. The dynamic loads are to be estimated from the sensor outputs. These are affected by both truck and bridge dynamics and these must be accounted for within the load estimation process. Estimation may be susceptible to many factors including static mass distribution, vehicle longitudinal motion, variations in lateral position on the bridge, as well as any surface unevenness. The focus of this paper is on using high fidelity simulation models to develop appropriate methodologies for load estimation which optimize the use of sensors on the truck. The estimation methods are evaluated in the context of any loss of accuracy in the predicted bridge response and in particular the coherency between inputs and outputs. It is proposed that using only static tire load data, GPS satellite data, string-potentiometers and accelerometer measurements, a robust measurement system can be constructed. The goal is to use near real-time processing of truck sensor data so that dynamic truck loads are available; when combined with data from separate bridge-mounted sensors, the structural performance of the structure can be evaluated. Â© 2013 SAE International.
A geometric formulation of the law of Aboav?Weaire in two and three dimensions

The law of Aboav–Weaire is a simple mathematical expression deriving from empirical observations that the number of sides of a grain is related to the average number of sides of the neighboring grains, and is usually restricted to natural two-dimensional microstructures. Numerous attempts have been made to justify this relationship theoretically, or to derive an analogous relation in three dimensions. This paper provides several exact geometric results with expressions similar to that of the usual law of Aboav–Weaire, though with additional terms that may be used to establish when the law of Abaov–Weaire is a suitable approximation. Specifically, we derive several local relations that apply to individual grain clusters, and a corresponding global relation that is identical in two and three dimensions except for a single parameter ζ. The derivation requires the definition and investigation of the average excess curvature, a previously unconsidered physical quantity. An approximation to our exact result is compared to the results of extensive simulations in two and three dimensions, and we provide a compact expression that strikes a balance between complexity and accuracy.
A fast solver for multi-particle scattering in a layered medium

In this paper, we consider acoustic or electromagnetic scattering in two dimensions from an infinite three-layer medium with thousands of wavelength-size dielectric particles embedded in the middle layer. Such geometries are typical of microstructured composite materials, and the evaluation of the scattered field requires a suitable fast solver for either a single configuration or for a sequence of configurations as part of a design or optimization process. We have developed an algorithm for problems of this type by combining the Sommerfeld integral representation, high order integral equation discretization, the fast multipole method and classical multiple scattering theory. The efficiency of the solver is illustrated with several numerical experiments.
Optoelectronic Properties of Single-Wall Carbon Nanotubes

Single-wall carbon nanotubes (SWCNTs), with their uniquely simple crystal structures and chirality-dependent electronic and vibrational states, provide an ideal laboratory for the exploration of novel 1D physics, as well as quantum engineered architectures for applications in optoelectronics. This article provides an overview of recent progress in optical studies of SWCNTs. In particular, recent progress in post-growth separation methods allows different species of SWCNTs to be sorted out in bulk quantities according to their diameters, chiralities, and electronic types, enabling studies of ( n , m )dependent properties using standard macroscopic characterization measurements. Here, a review is presented of recent optical studies of samples enriched in ‘armchair’ ( n = m ) species, which are truly metallic nanotubes but show excitonic interband absorption. Furthermore, it is shown that intense ultrashort optical pulses can induce ultrafast bandgap oscillations in SWCNTs, via the generation of coherent phonons, which in turn modulate the transmission of a delayed probe pulse. Combined with pulse-shaping techniques, coherent phonon spectroscopy provides a powerful method for studying exciton-phonon coupling in SWCNTs in a chirality-selective manner. Finally, some of the basic properties of highly aligned SWCNT fi lms are highlighted, which are particularly well-suited for optoelectronic applications including terahertz polarizers with nearly perfect extinction ratios and broadband photodetectors.
Competitive equality as a criterion for financial reform

Abstract Many arguments about financial reform appeal to competitive equality among types of institutions. But this is irrelevant; what matters is equitable treatment, not of institutions, but of their owners and customers, and economic efficiency. There are two rival definitions of the former, avoidance of unexpected regulatory changes, and changing regulations to maintain markets. If no externalities exist, equity to customers requires imposing the same burden on customers of all institutions. So does the efficiency criterion. These criteria are applied to three problems: permitting demand deposits in thrifts, imposing a reserve requirement on such deposits, and eliminating Regulation Q.
Unusual conformational effects on the regioselectivity of olefin insertion in the rhodium-catalyzed hydroformylation of 4-methylene-1,3-dioxanes

Abstract A mechanistic model for the rhodium-catalyzed hydroformylation of 4-methylene-1,3-dioxanes is described. As part of a study aimed at an anti -diastereoselective hydroformylation, unusual conformational effects on the regioselectivity of the reaction were discovered. This discovery has led to the proposal that the product mixtures are governed by classical Curtin-Hammett kinetics.
The Use and Abuse of Mutual Fund Expenses

Prior research shows that mutual fund investors are often aware of up-front charges like sales loads, but they are less mindful of annual operating expenses, even though both types of fees lower overall performance. This study documents the historical trend and recent abuse of annual mutual fund expenses. As the industry becomes more adept at segmenting customers by level of investment sophistication, we claim that load mutual fund companies take advantage of this ability and charge higher expenses to their target customer: the less-knowledgeable investor. No-load fund companies, which tend to attract the more sophisticated investor, offer lower expenses. For example, over 2000–2004 the average annual expense ratio of load equity funds was 50 basis points higher than no-load equity funds. We show evidence of this widening cost disparity since the early 1990s among new and existing equity, bond, and index funds. We also document a growing abuse of sales distribution or 12b-1 fees among funds that are closed to new investors, almost all of which are load funds. Thus, load fund investors are more susceptible to paying higher expenses and receiving lower returns over time.
Intraoperative electron irradiation in the management of pediatric malignancies.

BACKGROUND External beam irradiation (EBRT), especially in children, is limited by the radiosensitivity of normal tissues. Local control remains a problem in abdominopelvic childhood malignancies. Intraoperative electron irradiation (IOERT) has the potential to increase the dose to the tumor, thereby improving local control, without increasing treatment morbidity. METHODS Between February 1983 and October 1990, 11 children received IOERT as part of a multidisciplinary treatment program for locally advanced primary or recurrent abdominopelvic malignancies. The 7 boys and 4 girls ranged in age from 2-18 years. Tumor histologies included four neuroblastomas, two desmoid tumors, and one each of the following: embryonal rhabdomyosarcoma, synovial cell sarcoma, neurofibrosarcoma, malignant fibrous histiocytoma, and paraganglioma. Single radiation doses of 10-25 grays were delivered using 6-15-megaelectron volt electron beams to 1-5 IOERT fields. All patients also underwent EBRT and six received chemotherapy. RESULTS Eight patients (73%) were alive and disease free at a median follow-up of 99 months (range, 37-126 months). All eight patients who underwent gross total resection were locally controlled. Three patients required surgical intervention for IOERT-related complications and two patients developed neuropathies. CONCLUSIONS IOERT as part of a multidisciplinary treatment approach in patients with locally advanced pediatric malignancies appears to enhance local control in those patients in whom a gross total resection is possible. The long term survival rate was encouraging. Further study, with a larger number of patients, appears warranted to more carefully delineate the efficacy and tolerance of IOERT in the pediatric population. Cancer 1997; 79:2251-6. © 1997 American Cancer Society.
Altitude dependence of atmospheric temperature trends: Climate models versus observation

[1] As a consequence of greenhouse forcing, all state-of-the-art general circulation models predict a positive temperature trend that is greater for the troposphere than the surface. This predicted positive trend increases in value with altitude until it reaches a maximum ratio with respect to the surface of as much as 1.5 to 2.0 at about 200–400 hPa. However, the temperature trends from several independent observational data sets show decreasing as well as mostly negative values. This disparity indicates that the three models examined here fail to account for the effects of greenhouse forcings.
Is Fiscal Policy More Effective During Cyclical Downturns

Using a panel data set of 61 countries for the 1952–2007 period, the paper shows that fiscal policy is more potent during downturns than during expansions, and that the difference is substantial: the fiscal multiplier is twice as large when output is below its long-term trend. In particular, the empirical results suggest that during expansions the output ‘multiplier’ is less than one, private consumption is crowded out, and the response of investment is weak; whereas during downturns the output multiplier is greater than one, private consumption is not crowded out, and the response of investment is strong. Differences between expansion and downturn multipliers are found to be greater in low-income countries.
Warped entanglement entropy

We study the applicability of the covariant holographic entanglement entropy proposal to asymptotically warped AdS3 spacetimes with an SL(2, ℝ) × U(1) isometry. We begin by applying the proposal to locally AdS3 backgrounds which are written as an ℝ1 fibration over AdS2. We then perturb away from this geometry by considering a warping parameter a = 1 + δ to get an asymptotically warped AdS3 spacetime and compute the dual entanglement entropy perturbatively in δ. We find that for large separation in the fiber coordinate, the entanglement entropy can be computed to all orders in δ and takes the universal form appropriate for two-dimensional CFTs. The warping-dependent central charge thus identified exactly agrees with previous calculations in the literature. Performing the same perturbative calculations for the warped BTZ black hole again gives universal two-dimensional CFT answers, with the left-moving and right-moving temperatures appearing appropriately in the result.