cssi/SciSciGPT-SciSciNet huggingface dataset:
On Controller-Stopper Problems with Jumps and Their Applications to Indifference Pricing of American Options

We consider controller-stopper problems in which the controlled processes can have jumps. The global filtration is represented by the Brownian filtration, enlarged by the filtration generated by the jump process. We assume that there exists a conditional probability density function for the jump times and marks, given the filtration of the Brownian motion, and decompose the global controller-stopper problem into controller-stopper problems with respect to the Brownian filtration, which are determined by a backward induction. We apply our decomposition method to indifference pricing of American options under multiple default risk. The backward induction leads to a system of reflected backward stochastic differential equations (RBSDEs). We show that there exists a solution to this RBSDE system and that the solution provides a characterization of the value function.
Radio Frequency Spectra of 388 Bright 74 MHz Sources

As a service to the community, we have compiled radio frequency spectra from the literature for all sources within the VLA Low Frequency Sky Survey (VLSS) that are brighter than 15 Jy at 74 MHz. Over 160 references were used to maximize the amount of spectral data used in the compilation of the spectra, while also taking care to determine the corrections needed to put the flux densities from all reference on the same absolute flux density scale. With the new VLSS data, we are able to vastly improve on previous efforts to compile spectra of bright radio sources to frequencies below 100 MHz because (1) the VLSS flux densities are more reliable than those from some previous low-frequency surveys and (2) the VLSS covers a much larger area of the sky ( -->δ > − 30°) than many other low-frequency surveys (e.g., the 8C survey). In this paper, we discuss how the spectra were constructed and how parameters quantifying the shapes of the spectra were derived. Both the spectra and the shape parameters are made available here to assist in the calibration of observations made with current and future low-frequency radio facilities.
Approximation of Projections of Random Vectors

Let X be a d-dimensional random vector and Xθ its projection onto the span of a set of orthonormal vectors {θ1,…,θk}. Conditions on the distribution of X are given such that if θ is chosen according to Haar measure on the Stiefel manifold, the bounded-Lipschitz distance from Xθ to a Gaussian distribution is concentrated at its expectation; furthermore, an explicit bound is given for the expected distance, in terms of d, k, and the distribution of X, allowing consideration not just of fixed k but of k growing with d. The results are applied in the setting of projection pursuit, showing that most k-dimensional projections of n data points in ℝd are close to Gaussian, when n and d are large and k=clog (d) for a small constant c.
Analysis of Accelerated Motion in the Theory of Relativity

CONVENTIONAL treatments of accelerated motion in the theory of relativity have led to certain difficulties of interpretation. Thus, Crampin, McCrea and McNally1 mention the lack of uniformity in the correspondence of events as depicted by the transformation of Born and Biem. Again, Donahue and Leffert2 and Moller3 discuss certain reversals in the apparent gravitational field of an accelerated body. I have found4 that these difficulties may be avoided by simpler analysis based on the use of restricted conformal transformations. In the conformal theory the velocity of light remains constant even for experimenters in accelerated motion.
Quantitative nanostructure characterization using atomic pair distribution functions obtained from laboratory electron microscopes

Quantitatively reliable atomic pair distribution functions (PDFs) have been obtained from nanomaterials in a straightforward way from a standard laboratory transmission electron microscope (TEM). The approach looks very promising for making electron derived PDFs (ePDFs) a routine step in the characterization of nanomaterials because of the ubiquity of such TEMs in chemistry and materials laboratories. No special attachments such as energy filters were required on the microscope. The methodology for obtaining the ePDFs is described as well as some opportunities and limitations of the method.
Determinants of the Distribution of Congressional Earmarks Across States

Abstract This paper examines pork-barrel spending within states and finds that per capita earmarked funding is correlated with the inverse of a state's population, the presence of a Republican Congressional delegation, and the tenure of a state's senior Senator.
Reserve ratio, seigniorage and growth

A monetary endogenous growth model is developed by explicitly taking into account the growth-enhancing effects of reserve-augmented seigniorage. The seigniorage is generated by imposing a reserve requirement on the banking sector. The benevolent government then spends all the seigniorage revenue on the provision of a public input which has positive externality on the private sector's production. The growth effect of an increase in reserve requirement is then analyzed. An increase in reserve requirement has two opposing effects on growth. One is the well-known distortionary effect on the asset mix of the banks as well as the firm's input mix between intermediated and unintermediated capital. The other is a positive supply-side effect which arises due to the externality of public spending. A growth Laffer-curve type relationship is thus obtained between reserve ratio and growth. The model admits a second best reserve ratio.
A graph-theoretic analysis of the human protein-interaction network using multicore parallel algorithms

Due to fundamental physical limitations and power constraints, we are witnessing a paradigm shift in commodity microprocessor architecture to multicore designs. Continued performance now requires the exploitation of concurrency at the algorithm level. In this article, we demonstrate the application of high performance computing techniques in systems biology and present multicore algorithms for the important research problem of protein-interaction network (PIN) analysis. PINs play an important role in understanding the functional and organizational principles of biological processes. Promising computational techniques for key systems biology research problems such as identification of signaling pathways, novel protein function prediction, and the study of disease mechanisms, are based on topological characteristics of the protein interactome. Several complex network models have been proposed to explain the evolution of protein networks, and these models primarily try to reproduce the topological features observed in yeast, the model eukaryote interactome. In this article, we study the structural properties of a high-confidence human interaction network, constructed by assimilating recent experimentally derived interaction data. We identify topological properties common to the yeast and human protein networks. Betweenness is a quantitative measure of centrality of an entity in a complex network, and is based on computing all-pairs shortest paths in the graph. A novel contribution of our work is the analysis of the degree-betweenness centrality correlation in the human PIN. Jeong et al. empirically showed that betweenness is positively correlated with the essentiality and evolutionary age of a protein. We observe that proteins with high betweenness, but low degree (or connectivity) are abundant in the human PIN. We have designed efficient and portable parallel implementations for the exact calculation of betweenness and other compute-intensive centrality metrics relevant to interactome analysis. For example, on the Sun Fire T2000 server with the UltraSparc T1 (Niagara) processor, we achieve a relative speedup of about 16 using 32 threads for a typical instance of betweenness centrality on a PIN, reducing the running time from nearly 312min to 13s.
Are All Proximity Effects Created Equal? Fast Food Near Schools and Body Weight Among Diverse Adolescents

Abstract Prior research has demonstrated that the proximity of fast-food restaurants to schools is related to higher youth body weight and also suggests that this relationship may be stronger in urban areas. Research also suggests that some segments of youth may be more vulnerable to this relationship than others. The authors investigate the relationship of fast-food proximity to middle and high schools and adolescent weight outcomes, with a focus on understanding intra-urban differences across groups defined by ethnicity and school income. Their results suggest that body weight associations with proximity to a fast-food restaurant from school are not equal for all youth. Black and Hispanic students at low-income and urban schools have higher associations between school–fast food distance and youth body weight, up to four times greater than general distance associations. The authors discuss their findings in light of the complexity of understanding the relationship between retail marketing proximity and w...
Some aspects of the Lewis base and ligand behavior of N-heterocyclic carbenes

Abstract The present article is primarily an overview of recent work from the author's laboratory on the chemistry of stable N -heterocyclic carbenes. The first section deals with complexes of stable N -heterocyclic carbenes with phosphinidenes and arsenidenes, the focal points being preparative methods, molecular structures, electronic structures, and patterns of reactivity. The second section is devoted to complexes of stable N -heterocyclic carbenes with d-block metallocenes. Two general approaches have been taken to the preparation of such complexes, namely the direct reaction of stable N -heterocyclic carbenes with metallocenes and the reaction of metallocenes with imidazolium chlorides. The molecular structures of several representative complexes have been determined by X-ray crystallography.
Using Game Theory and Strategic Reasoning Concepts to Prevent and Detect Fraud

This commentary examines academic research that can assist auditors in detecting and preventing fraudulent financial reporting. We review theoretical and empirical research from game theory, social psychology, judgment and decision making, and auditing to identify improvements in audit practice and promising areas for future research. This review focuses on the strategic fraud setting and suggests modifications in auditing standards that should facilitate auditors' use of strategic reasoning in this setting. We emphasize three critical audit tasks—fraud risk assessment, audit planning, and audit plan implementation—and recommend changes to current auditing standards and identify potential research questions for each task.
Spin waves in a spin-1 normal Bose gas

We present a theory of spin waves in a noncondensed gas of spin-1 bosons and provide both analytic calculations of the linear theory and full numerical simulations of the nonlinear response. We highlight the role of spin-dependent contact interactions in the dynamics of a thermal gas. Although these interactions are small compared to the thermal energy, they set the scale for low-energy, long-wavelength spin waves. In particular, we find that the polar state of {sup 87}Rb is unstable to collisional mixing of magnetic sublevels even in the normal state. We augment our analytic calculations by providing full numerical simulations of a trapped gas, explicitly demonstrating this instability. Further, we show that for strong antiferromagnetic interactions, the polar gas is unstable. Finally, we explore coherent population dynamics in a collisionless transversely polarized gas.
Electronic structure of silicide-silicon interfaces

Abstract Over the past few years the electronic structure of transition metal-silicon and silicide-silicon interfaces (and of bul;k silicide compounds) has been revealed for the first time, using surface spectroscopies (photoemission and Auger) and theoretical calculations. These investigations, which have included palladium, platinum, nickel, vanadium, chromium, molybdenum and tungsten, have elucidated the important role played by the chemical bond between the transition metal d and the Si 3p electrons. They have also shown the high chemical reactivity of the atomically clean transition metal-silicon interface, which leads to interfacial silicide formation at relatively low temperatures (i.e. markedly below those needed for bulk silicide formation on chemically cleaned silicon surfaces). As a result, silicide-like chemical bonding dominates the interface electronic structure of such contacts under a wide variety of conditions. Detailed comparisons of interface spectra (observed at low metal coverages) with those of the bulk silicide reaction products give strong evidence for additional electronic states of relatively high density (about 0.1 states per interface atom) which lie in or near the silicon band gap region. These states are believed to be true interface states associated with localized bonding configurations unique to the atoms at the interface, and they could explain the silicon-rich silicide composition of a thin (about 3–5 A) interfacial region which has been observed by Auger composition analysis and suggested by chemical shifts in core and valence electron densities of states. Finally, metal atom diffusion into the silicon substrate has been observed in ion channeling studies and suggested from surface spectroscopy results; these impurity atoms should produce defect states localized near the interface and lying within the silicon band gap, although these electronic states have not yet been directly observed. As a whole these results present a fairly detailed picture of the electronic structure and chemistry of the silicide-silicon interface. However, correlations with the interface electrical properties are needed to ascertain which electronic features and chemical mechanisms in fact determine the Schottky barrier height of the contact.
ON THE ERUPTION OF CORONAL FLUX ROPES

We present three-dimensional MHD simulations of the evolution of the magnetic field in the corona where the emergence of a twisted magnetic flux tube is driven at the lower boundary into a pre-existing coronal potential arcade field. Through a sequence of simulations in which we vary the amount of twisted flux transported into the corona before the emergence is stopped, we investigate the conditions that lead to a dynamic eruption of the resulting coronal flux rope. It is found that the critical condition for the onset of eruption is for the center of the flux rope to reach a critical height at which the corresponding potential field declines with height at a sufficiently steep rate, consistent with the onset of the torus instability of the flux rope. In some cases, immediately after the emergence is stopped, the coronal flux rope first settles into a quasi-static rise with an underlying sigmoid-shaped current layer developing. Preferential heating of field lines going through this current layer may give rise to the observed quiescent X-ray sigmoid loops before eruption. Reconnections in the current layer during the initial quasi-static stage is found to add detached flux to the coronal flux rope, allowing it to rise quasi-statically to the critical height and dynamic eruption of the flux rope then ensues. By identifying field lines whose tops are in the most intense part of the current layer during the eruption, we deduce the evolution and morphology of the post-flare X-ray loops and the flare ribbons at their footpoints.
Bleeding events and other complications during pregnancy and childbirth in women with von Willebrand disease

Summary. Background: Case reports and case series suggest that women with von Willebrand disease (VWD) are at an increased risk of bleeding complications during pregnancy and delivery. Objectives: To estimate the incidence of bleeding events and other complications in women with VWD during pregnancy and childbirth. Methods: The United States Nationwide Inpatient Sample (NIS) from the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality for the years 2000–2003 was queried for all pregnancy-related discharges. Women with a diagnosis of VWD were compared with women without VWD. Data were analyzed based on the NIS sampling design. Logistic regression was used to compute odds ratios with 95% CI. Results: There were 4067 deliveries among women with VWD (1 in 4000 deliveries). Although women with VWD were more likely to experience antepartum bleeding [odds ratio (OR) 10.2, 95% CI: 7.1, 14.6], they were no more likely to experience premature labor, placental abruption, fetal growth restriction or intrauterine fetal demise. Women with VWD were more likely to experience a postpartum hemorrhage (OR, 1.5; 95% CI: 1.1, 2.0), and had a 5-fold increased risk of being transfused (OR, 4.7; 95% CI: 3.2, 7.0). Five of the 4067 women with VWD died, a maternal mortality rate 10 times higher than that for other women. Conclusions: Although women with VWD do not appear to be at an increased risk of poor fetal outcomes, they are at an increased risk of bleeding events and possibly death during pregnancy and childbirth.
Vacuum mass spectra for SU(N) self-dual Chern-Simons-Higgs systems☆

Abstract We study the SU(N) self-dual Chem-Simons-Higgs systems with adjoint matter coupling, and show that the sixth-order self-dual potential has p(N) gauge inequivalent degenerate minima, where p(N) is the number of partitions of N. We compute the masses of the gauge and scalar excitations in these different vacua, revealing an intricate mass structure which reflects the self-dual nature of the model.
Search for CP violation at CLEO

Abstract Recent results from CLEO on the search for CP violation in beauty and charm meson decays are reviewed.
High temperature adsorption isotherms on equilateral triangular terraces

Abstract Within the context of a lattice–gas model, the adsorption isotherms on infinitely long equilateral triangular terraces are obtained at high temperature using a recently developed transfer matrix method. The computations, using long double precision arithmetic, are conducted for semi-infinite terraces with two different orientations, an increasing number M of atomic sites in their width, and without a periodic boundary. Our general formulation recovers the known results of the statistical average of the coverage and the entropy per site divided by Boltzmann's constant, which is independent of M and given by the one-dimensional solution ( M = 1 ). We report as new results the values of θ ( M , θ 0 ) and β ( M , θ 0 ) , which are the statistical averages of the numbers of first- and second-neighbors per site, respectively, as functions of the width M and the coverage θ 0 . These functions, when scaled according to their maximum values obtained at full coverage, both reduce to θ 0 2 for all M . With this new information, we show that in the infinite- M limit, and at half coverage, the adsorbate occupational configuration exhibits repetitive hexagonal patterns.
An LIL for cover times of disks by planar random walk and Wiener sausage

Let be the radius of the largest disk covered after steps of a simple random walk. We prove that almost surely where denotes 3 iterations of the function. This is motivated by a question of Erdos and Taylor. We also obtain the analogous result for the Wiener sausage, refining a result of Meyre and Werner.
Total syntheses of squamocin A and squamocin D

Abstract The total syntheses of two acetogenins, squamocin A and squamocin D, have been achieved. The adjacent bis-THF subunit was constructed by a multiple Williamson reaction. The left and the right side chain were added by addition of organomagnesium compounds to aldehyde functions. The conversion of a carboxylic acid into the butenolide moiety concluded both syntheses.
Dioxygen-copper reactivity. Reversible binding of O2 and CO to a phenoxo-bridged dicopper(I) complex

[Cu 2 (XYL-O−)]PF 6 cristallise dans le systeme monoclinique avec le groupe d'espace P2 1 /n (R=0,0587). [Cu 2 (XYL-O−)(PPh 3 ) 2 ]PF 6 cristallise dans le systeme triclinique avec le groupe d'espace P1 (R=0,0968)
Ordering of rare gas films on a decagonal Al-Ni-Co quasicrystal

This paper reviews recent progress in the study of rare gas films on quasicrystalline surfaces. The adsorption of Xe on the 10-fold surface of decagonal Al–Ni–Co was studied using low-energy electron diffraction (LEED). The results of these studies prompted the development of a theoretical model, which successfully reproduced the thermodynamic parameters found in the experiment. Grand canonical Monte Carlo (GCMC) simulations for Xe-produced structures that agreed with the experimental observations of the adsorption structures and provided a deeper insight into the nature of the ordering. A first-order commensurate–incommensurate transition, which involves a transition from a quasicrystalline five-fold structure to a periodic hexagonal structure, was discovered and characterized for the Xe monolayer. The five rotational domains of the hexagonal structure observed in the LEED study were shown in the GCMC study to be mediated by pentagonal defects, which are entropic in nature, and not by substrate defects. ...
Asymptotic valuations of sequences satisfying first order recurrences

Let t n be a sequence that satisfies a first order homogeneous recurrence t n = Q(n)t n-1 , where Q is a polynomial with integer coefficients. We describe the asymptotic behavior of the p-adic valuation of t n .
Highly enantioselective formal aza-Diels-Alder reactions with acylhydrazones and Danishefsky's diene promoted by a silicon Lewis acid

Abstract Silicon Lewis acid 3 is effective for the promotion of highly enantioselective cycloaddition reactions of acylhydrazones with Danishefsky's diene (formal aza-Diels–Alder reactions). The reactions are conducted at ambient temperature for 15 min, and produce the products in good yield and with high levels of enantioselectivity. A remarkable solvent-dependent reversal in the sense of absolute stereochemical induction has been observed. The method has been applied to an efficient and stereoselective synthesis of the neurokinin 1 receptor antagonist casopitant.
Broken ergodicity and the geometry of rugged landscapes.

We study the nature and mechanisms of broken ergodicity (BE) in specific random walk models corresponding to diffusion on random potential surfaces, in both one dimension and high dimension. Using both rigorous results and nonrigorous methods, we confirm several aspects of the standard BE picture and show that others apply in one dimension, but need to be modified in higher dimensions. These latter aspects include the notions that a fixed temperature confining barriers increase logarithmically with time, that ``components'' are necessarily bounded regions of state space which depend on the observational time scale, and that the system continually revisits previously traversed regions of state space. We examine our results in the context of several experiments, and discuss some implications of our results for the dynamics of disordered and/or complex systems.
No Prejudice in Space

We present a summary of recent results obtained from a scan of the 19-dimensional parameter space of the pMSSM and its implications for dark matter searches. We have generated a large set of points in parameter space (which we call 'models') for the 19-parameter CP-conserving pMSSM, where MFV has been assumed. We subjected these models to numerous experimental and theoretical constraints to obtain a set of {approx}68 K models which are consistent with existing data. We attempted to be somewhat conservative in our implementation of these constraints; in particular we only demanded that the relic density of the LSP not be greater than the measured value of {Omega}H{sup 2} for non-baryonic dark matter, rather than assuming that the LSP must account for the entire observed relic density. Examining the properties of the neutralinos in these models, we find that many are relatively pure gauge eigenstates with Higgsinos being the most common, followed by Winos. The relative prevalence of Higgsino and Wino LSPs leads many of our models to have a chargino as nLSP, often with a relatively small mass splitting between this nLSP and the LSP; this has important consequences in both collider and astroparticle phenomenology. We find that, inmore » general, the LSP in our models provides a relatively small ({approx} 4%) contribution to the dark matter, however there is a long tail to this distribution and a substantial number of models for which the LSP makes up all or most of the dark matter. Typically these neutralinos are mostly Binos. Examining the signatures of our models in direct and indirect dark matter detection experiments, we find a wide range of signatures for both cases. In particular, we find a much larger range of WIMP-nucleon cross sections than is found in any particular model of SUSY-breaking. As these cross sections also enter the regions of parameter space suggested by non-SUSY models, it appears that the discovery of WIMPs in direct detection experiments might not be sufficient to determine the correct model of the underlying physics. As a first look at the signatures of these models in indirect detection experiments, we examined whether our models could explain the PAMELA excess in the positron to electron ratio at high energies. We find that there are models which fit the PAMELA data rather well, and some of these have significantly smaller boost factors than generally assumed for a thermal relic. The study of the pMSSM presents exciting new possibilities for SUSY phenomenology. The next few years will hopefully see important discoveries both in colliders and in satellite or ground-based astrophysical experiments. It is important that we follow the data and not our existing prejudices; hopefully this sort of relatively model-independent approach to collider and astrophysical phenomenology can be useful in this regard.« less
Futures Versus Share Contracting as Means of Diversifying Output Risk

Two means by which commodity producers can reduce their exposure to quantity risk are share contracting and futures hedging. This paper explains the coexistence of these arrangements by showing that these will normally be complementary means of transferring risk. Share contracting by a purchaser with many producers can help diversify imperfectly correlated quantity risks. Futures contracts, on the other hand, hedge the systematic but not the idiosyncratic components of output risk. Thus, futures hedging helps to ameliorate the main disadvantage of multiple share contracting, an excessive loading of systematic risk on the purchaser. Copyright 1993 by Royal Economic Society.
Optimally squeezed spin states

We consider optimally spin-squeezed states that maximize the sensitivity of the Ramsey spectroscopy, and for which the signal-to-noise ratio scales as the number of particles N. Using the variational principle we prove that these states are eigensolutions of the Hamiltonian $H(\ensuremath{\lambda})=\ensuremath{\lambda}{S}_{z}^{2}\ensuremath{-}{S}_{x},$ and that, for large N, the states become equivalent to the quadrature squeezed states of the harmonic oscillator. We present numerical results that illustrate the validity of the equivalence.
Synthesis of coatings with hardness exceeding 40 GPa by magnetron sputtering

Single- and dual-cathode DC magnetron sputtering was used to produce TiB 2 coatings and CN x /ZrN multilayers, respectively, with hardness exceeding 40 GPa. The composition, structure, topography, and mechanical properties were determined by various techniques, including Auger electron spectroscopy, X-ray diffraction, high-resolution electron microscopy, atomic force microscopy, and nanoindentation. An optimum combination of the sputtering pressure and substrate bias results in the production of ultrasmooth TiB 2 coatings with hardness up to 50 GPa and excellent wetting properties. The rationale for studying the CN x /ZrN system is that ZrN(111) provides excellent lattice match to the hypothetical β-C 3 N 4 (0001) face (β-C 3 N 4 was predicted to have mechanical properties comparable to diamond). Using a dual-cathode sputtering system, we produced crystalline multilayers of CN x /ZrN with bilayer thickness of 1-2 nm. Using various combinations of nitrogen partial pressure, target powers, and substrate bias, we found that the hardness of these coatings correlates very strongly with the occurrence of (111) texture of ZrN, consistent with the lattice-match strategy. Even with a ZrN volume fraction of 70 percent, such multilayer coatings have been synthesized with hardness in the 50 GPa regime.
The X-Ray Binary Population in M33. I. Source List and Luminosity Function

In this paper we present the source list for three Chandra observations of the Local Group galaxy M33. The observations are centered on the nucleus and on the star-forming region NGC 604. We detect a total of 261 sources in an area of ~0.2 deg2 down to a flux limit of 3 × 10-16 ergs s-1 cm-2, which corresponds to a luminosity of ~2 × 1034 ergs s-1 at a distance of 840 kpc. From the source list we construct the luminosity functions of sources observed in M33. If we take into account background contamination, the luminosity functions are consistent with those of other star-forming galaxies. In addition, the combination of X-ray color analysis and the existence of "blue" optical counterparts strongly indicates that the X-ray point-source population in M33 consists of young objects. Above 3 × 1035 ergs s-1 there are few X-ray sources in the locus of the X-ray hardness ratio diagram that is generally populated by low-mass X-ray binaries.
Shifted L-BFGS systems

We investigate fast direct methods for solving systems of the form (B+G)x=y, where B is a limited-memory Broyden-Fletcher-Goldfarb-Shanno matrix and G is a symmetric positive-definite matrix. These systems, which we refer to as shifted L-BFGS systems, arise in several settings, including trust-region methods and preconditioning techniques for interior-point methods. We show that under mild assumptions, the system (B+G)x=y can be solved in an efficient manner that mitigates instability via a recursion that requires only vector inner products. We consider various shift matrices G and demonstrate the effectiveness and accuracy of the recursion method in numerical experiments.
Chemistry of Polyvalent Iodine

Starting from the early 1990’s, the chemistry of polyvalent iodine organic compounds has experienced an explosive development. This surging interest in iodine compounds is mainly due to the very useful oxidizing properties of polyvalent organic iodine reagents, combined with their benign environmental character and commercial availability. Iodine(III) and iodine(V) derivatives are now routinely used in organic synthesis as reagents for various selective oxidative transformations of complex organic molecules. Several areas of hypervalent organoiodine chemistry have recently attracted especially active interest and research activity. These areas, in particular, include the synthetic applications of 2-iodoxybenzoic acid (IBX) and similar oxidizing reagents based on the iodine(V) derivatives, the development and synthetic use of polymer-supported and recyclable polyvalent iodine reagents, the catalytic applications of organoiodine compounds, and structural studies of complexes and supramolecular assemblies of polyvalent iodine compounds. The chemistry of polyvalent iodine has previously been covered in four books1–4 and several comprehensive review papers.5–17 Numerous reviews on specific classes of polyvalent iodine compounds and their synthetic applications have recently been published.18–61 Most notable are the specialized reviews on [hydroxy(tosyloxy)iodo]benzene,41 the chemistry and synthetic applications of iodonium salts,29,36,38,42,43,46,47,54,55 the chemistry of iodonium ylides,56–58 the chemistry of iminoiodanes,28 hypervalent iodine fluorides,27 electrophilic perfluoroalkylations,44 perfluoroorgano hypervalent iodine compounds,61 the chemistry of benziodoxoles,24,45 polymer-supported hypervalent iodine reagents,30 hypervalent iodine-mediated ring contraction reactions,21 application of hypervalent iodine in the synthesis of heterocycles,25,40 application of hypervalent iodine in the oxidation of phenolic compounds,32,34,50–53,60 oxidation of carbonyl compounds with organohypervalent iodine reagents,37 application of hypervalent iodine in (hetero)biaryl coupling reactions,31 phosphorolytic reactivity of o-iodosylcarboxylates,33 coordination of hypervalent iodine,19 transition metal catalyzed reactions of hypervalent iodine compounds,18 radical reactions of hypervalent iodine,35,39 stereoselective reactions of hypervalent iodine electrophiles,48 catalytic applications of organoiodine compounds,20,49 and synthetic applications of pentavalent iodine reagents.22,23,26,59 The main purpose of the present review is to summarize the data that appeared in the literature following publication of our previous reviews in 1996 and 2002. In addition, a brief introductory discussion of the most important earlier works is provided in each section. The review is organized according to the classes of organic polyvalent iodine compounds with emphasis on their synthetic application. Literature coverage is through July 2008.
Media streaming via TFRC: An analytical study of the impact of TFRC on user-perceived media quality

TCP-Friendly Rate Control (TFRC) is being adopted in Internet standards for congestion control of streaming media applications. In this paper, we consider the transmission of prerecorded media from a server to a client by using TFRC, and analytically study the impact of TFRC on user-perceived media quality, which is roughly measured by calculating the rebuffering probability. A rebuffering probability is defined to be the probability that the total duration of all rebuffering events experienced by a user is longer than a certain threshold. Several approaches are presented to help an application determine an appropriate initial buffering delay and media playback rate in order to achieve a certain rebuffering probability under a given network condition. First, we derive a closed-form expression to approximate the average TFRC sending rate, which could be used as the maximum allowed playback rate of a media stream. Second, we develop a queueing model for a TFRC client buffer with the traffic described by a Markov-Renewal-Modulated Deterministic Process (MRMDP), which captures the fundamental behavior of TFRC that predicts the immediate future TCP sending rate based on the history of past loss intervals. We present a closed-form solution and a more accurate iterative method to solve the queueing model and calculate the rebuffering probability.
Application of a Stereospecific Intramolecular Allenylsilane Imino Ene Reaction to Enantioselective Total Synthesis of the 5,11-Methanomorphanthridine Class of Amaryllidaceae Alkaloids

Enantioselective total syntheses of the pentacyclic 5,11-methanomorphanthridine Amaryllidaceae alkaloids (−)-montanine (1), (−)-coccinine (2), and (−)-pancracine (3) were accomplished using an intramolecular concerted pericyclic allenylsilane imino ene cycloaddition as a key step. These complex natural products were constructed starting from readily available enantiomerically pure epoxy alcohol 15 which was converted to allenylsilane aldehyde 28 via an efficient nine-step sequence. The imine generated from aldehyde 28 and iminophosphorane 47 underwent a stereospecific thermal imino ene reaction to afford key intermediate cis aminoalkyne 49. It was possible to transform this compound via Lindlar hydrogenation followed by an intramolecular Heck reaction to seven-membered ring tetracycle 51. This olefinic intermediate could be functionalized through its epoxide to yield α-hydroxymethyl intermediate 54, and then pentacyclic alcohol 64. Procedures were then developed to convert this material to the enantiomeri...
On the swirling flow between rotating coaxial disks: Existence and nonuniqueness

Abstract : Consider solutions G(x,epsilon), H(x,epsilon) of the von Karman equations for the swirling flow between two rotating coaxial disks (1.1) epsilonH superscript iv + HH''' + GG' equal 0 and (1.2) epsilonG' + HG' - H'G equal 0 with boundary conditions (1.3 H(0,epsilon) equal H' (0,epsilon) equal H(1, epsilon) equal H'(1, epsilon) equal 0 (1.4) G(0, epsilon) equal s, G(1, epsilon) equal 1, s 1. In this work we establish the existence of solutions for epsilon small enough. In fact, if n is a given positive integer with sign s equal (-1 to the n power) then there is - for epsilon greater than 0 sufficiently small - a solution with the additional property: G(x, epsilon) has n interior zeros. If n 1 there are at least two such solutions. If s equal 0 there is at least one such solution for every positive integer n. The asymptotic shape of these solutions is described.
Upregulation of eosinophil adhesion to conjunctival epithelial cells by allergic tears is inhibited by treatment with olopatadine

Abstract Rationale The mechanism by which eosinophils adhere to the ocular surface during allergic inflammation is unknown. This study examined whether tears from allergic subjects upregulate the ability of human conjunctival epithelial cells (HCE) to promote eosinophil adhesion and the effect of the anti-allergic drug olopatadine on this process. Methods Allergic subjects were treated for 48 hrs with olopatadine in one eye. Tears were collected 24 hrs prior to allergen challenge (both eyes) and 30 min and 90 min post-challenge. HCE were pre-incubated with tears (diluted 1:125 in media) or controls (TNFα, IFNγ) for 24 hrs after which peripheral blood eosinophil adhesion to HCE was measured using an eosinophil peroxidase assay. Blocking antibodies to β2 integrins on eosinophils (A-β2), and ICAM-1 on HCE (A-ICAM-1), examined integrin specificity. Results Both pre and post-challenge tears activated HCE resulting in upregulated eosinophil adhesion (equivalent to levels of adhesion to TNFα, IFNγ stimulated HCE). Olopatadine treatment completely inhibited the ability of both pre and post-challenge tears to upregulate eosinophil adhesion (equivalent to levels of adhesion to unstimulated HCE). Blocking antibodies demonstrated that eosinophil adhesion to conjunctival epithelial cells in vitro was mediated by β2 integrins on eosinophils (completely inhibited by A-β2) but not via ICAM-1 on HCE (not inhibited by A-ICAM-1). Conclusions Olopatadine treatment inhibits the pro-inflammatory effect of allergic tears on eosinophil adhesion to HCE in vitro. In vivo, an effect of this magnitude (3–6×102 less eosinophils/cm2) could result in a significant decrease in the numbers of eosinophils maintained on the ocular surface in allergic inflammation.
The Path Resistance Method for Bounding the Smallest Nontrivial Eigenvalue of a Laplacian

We introduce the path resistance method for lower bounds on the smallest nontrivial eigenvalue of the Laplacian matrix of a graph. The method is based on viewing the graph in terms of electrical circuits: it uses clique embeddings to produce lower bounds on λ2 and star embeddings to produce lower bounds on the smallest Rayleigh quotient when there is a zero Dirichlet boundary condition. The method assigns priorities to the paths in the embedding; we show that, for an unweighted tree T, using uniform priorities for a clique embedding produces a lower bound on λ2 that is off by at most an O(log diameter(T)) factor. We show that the best bounds this method can produce for clique embeddings are the same as for a related method that uses clique embeddings and edge lengths to produce bounds.
Transition temperature in QCD with physical light and strange quark masses

We present results from a calculation of the transition temperature in QCD with two light (up, down) and one heavier (strange) quark mass as well as for QCD with three degenerate quark masses. Furthermore, we discuss first results from an ongoing calculation of the QCD equation of state with almost realistic light and strange quark masses.
The Margulis region and screw parabolic elements of bounded type

Given a discrete subgroup of the isometries of n-dimensional hyperbolic space there is always a region kept precisely invariant under the stabilizer of a parabolic fixed point, called the Margulis region. While in dimensions 2 and 3 this region is a horoball, it has in general a more complicated shape due to the existence of screw parabolic elements in higher dimensions. In fact, P. Susskind has shown that in a discrete group acting on hyperbolic 4-space containing a screw parabolic element with irrational rotation, the corresponding Margulis region does not contain a horoball. In this paper we describe the asymptotic behavior of the boundary of the Margulis region when the irrational screw parabolic is of bounded type. As a corollary we show that the region is quasi-isometric to a horoball. Although Y. Kim has shown that two screw parabolic isometries with irrational rotation are not conjugate by any quasi-isometry of hyperbolic 4-space, this corollary implies that their corresponding Margulis regions (in the bounded type case) are quasi-isometric.
Assessment of environmental implications of abandoned oil and gas wells

A detailed study was made of the potential for abandoned oil and gas wells in the Lower Tuscaloosa sand of Mississippi and Louisiana to act as conduits for movement of saline water from the Lower Tuscaloosa into underground sources of drinking water (USDW's). Finite-difference numerical modeling determined the extent that water might be forced from the Lower Tuscaloosa sand into a USDW as a result of injection into the Lower Tuscaloosa. Within the range of conditions modeled, water from the Lower Tuscaloosa never traveled into a USDW. On the basis of the modeling, the authors concluded that it is unlikely that abandoned oil and gas wells in the Lower Tuscaloosa would serve as conduits for water movement from the trend into a USDW. The procedures developed in this study should be readily applicable to analysis of the potential for abandoned wells to act as pathways for contaminant flow into USDW's in other oil and gas producing areas of the country.
Koszul configurations of points in projective spaces

Abstract We prove a new criterion for the homogeneous coordinate ring of a finite set of points in P n to be Koszul. Like the well-known criterion due to Kempf [G. Kempf, Syzygies for points in projective space, J. Algebra 145 (1992) 219–223] it involves only incidence conditions on linear spans of subsets of a given set. We also give a sufficient condition for the Koszul property to be preserved when passing to a subset of a finite set of points in P n .
Field theoretical description of quantum Hall edge reconstruction

We propose a generalization of the chiral Luttinger liquid theory to allow for a unified description of quantum Hall edges with or without edge reconstruction. Within this description edge reconstruction is found to be a quantum phase transition in the universality class of a one-dimensional dilute Bose gas transition, whose critical behavior can be obtained exactly. At principal filling factors v = l/m, we show the additional edge mode due to edge reconstruction modifies the point contact tunneling exponent in the low-energy limit, by a small and nonuniversal amount.
On the Polarization of Closed Strings by Ramond-Ramond Fluxes

In the Green-Schwarz formalism, the closed string worldsheet of the IIB theory couples to Ramond-Ramond (RR) fluxes through spinor bilinears. We study the effect of such fluxes by analyzing the supersymmetry transformation of the worldsheet in general backgrounds. We show that, in the presence RR fields, the closed string can get `polarized', as the spinors acquire non-zero vevs in directions correlating with the orientation of close-by D-branes. Reversing the argument, this may allow for worldsheet configurations—with non-trivial spinor structure—that source RR moments.
A NEW CORRELATION BETWEEN GRB X-RAY FLARES AND THE PROMPT EMISSION

From a sample of gamma-ray bursts (GRBs) detected by the Fermi and Swift missions, we have extracted the minimum variability timescales for temporal structures in the light curves associated with the prompt emission and X-ray flares. A comparison of this variability timescale with pulse parameters such as rise times, determined via pulse-fitting procedures, and spectral lags, extracted via the cross-correlation function, indicates a tight correlation between these temporal features for both the X-ray flares and the prompt emission. These correlations suggest a common origin for the production of X-ray flares and the prompt emission in GRBs.
Fluorescent Ca+2 analogs in nerve: Rare-earth ions

To probe the Ca+2 ion-nerve membrane interaction, rare-earth ions were used as analogs of Ca+2 in the bathing solution of garfish olfactory nerve trunk. We observed the chemically sensitive fluorescence of Eu+3 and Tb+3 as a measure of rare-earth binding to nerve, both resting and firing, and subjected to treatments with various enzymes, chemical agents, and abnormal salt concentrations. The main results are: 1) rare-earth ions bind to nerve proteins, NADH, and possibly other sites; 2) fractional changes of rare-earth fluorescence synchronous with firing are less than 0.02%; 3) most of the observed binding is a slow, continual uptake of rare-earth ion into the axoplasm, rate-limited by permeation through the axon membrane.
Particles and Sources

It is proposed that the phenomenological theory of particles be based on the source concept, which is abstracted from the physical possibility of creating or annihilating any particle in a suitable collision. The source representation displays both the momentum and the space-time characteristics of particle behavior. Topics discussed include: spin and statistics, charge and the Euclidean postulate, massless particles, and $S{U}_{3}$ and spin. It is emphasized that the source description is logically independent of hypotheses concerning the fundamental nature of particles.
Synthesis of Optically Active 4-Substituted 2-Cyclohexenones

Recently, Nicolaou and Baran independently synthesized optically active 4-substituted 2-cyclohexenones via an efficient LiOH-mediated intramolecular aldol condensation. Thus far, application of their cyclization approach has been limited to ketoaldehydes where the R-group is branched. It is demonstrated that the LiOH-mediated cyclization, when applied to substrates containing unbranched R-groups, results in significant erosion of optical purity. A mechanistic justification is provided, and a set of neutral, organocatalyzed conditions is identified that enables cyclization with little loss in optical purity.
Value-relevance of banks' derivatives disclosures

Abstract This paper investigates the value-relevance of banks' derivatives disclosures provided under SFAS 119. The findings suggest that the fair value estimates for derivatives help explain cross-sectional variation in bank share prices and that the fair values have incremental explanatory power over and above notional amounts of derivatives. I also conduct cross-sectional tests to provide preliminary evidence on the usefulness of derivatives disclosures in examining banks' risk-management strategies. While I find that banks, on average, are reducing their risk exposures using derivatives, further analysis reveals that only 47% of the sample banks appear to use derivatives to reduce risk.