cssi/SciSciGPT-SciSciNet huggingface dataset:
Random variables with completely independent subcollections

We investigate the algebra and geometry of the independence conditions on discrete random variables in which we consider a collection of random variables and study the condition of independence of some subcollections. We interpret independence conditions as an ideal of algebraic relations. After a change of variables, this ideal is generated by generalized 2×2 minors of multi-way tables and linear forms. In particular, let Δ be a simplicial complex on some random variables and A be the table corresponding to the product of those random variables. If A is Δ-independent table then A can be written as the entrywise sum AI+A0 where AI is a completely independent table and A0 is identically 0 in its Δ-margins. We compute the isolated components of the original ideal, showing that there is only one component that could correspond to probability distributions, and relate the algebra and geometry of the main component to that of the Segre embedding. If Δ has fewer than three facets, we are able to compute generators for the main component, show that it is Cohen–Macaulay, and give a full primary decomposition of the original ideal.
Flip: A low-dissipation, particle-in-cell method for fluid flow

Abstract The FLIP (Fluid-Implicit-Particle) method uses fully Lagrangian particles to eliminate convective transport, the largest source of computational diffusion in calculations of fluid flow. FLIP is an adaptation to fluids of the implicit moment method for simulating plasmas, in which particles carry everything necessary to describe the fluid. Using the particle data, Lagrangian moment equations are solved on a grid. The solutions are then used to advance the particle variables from time step to time step. An adaptive grid and implicit time differencing extend the method to multiple time and space scale flows. Aspects of FLIP's properties are illustrated by modeling of a confined eddy, a Rayleigh-Taylor, an unstable subsonic stream, and a supersonic jet. The results demonstrate FLIP's instability applicability to hydrodynamic stability problems where low dissipation is crucial to correct modeling.
Ion implantation effects in glasses

Abstract Ion implantation can be used to introduce network damage and to alter the chemical composition in glasses. Structural changes can be inferred from IR measurements near 1000 cm−1 and by optical absorption near 2150 A. Implantation-induced damage decreases the implanted volume in fused silica with consequent changes in the refractive index, the near-surface hardness, and the tensile surface stress. Prior work in these areas is reviewed. Implantation into alkali silicate glasses depletes the alkali content in the implanted region. These changes allow preferential surface crystallization in Li2O-2SiO2 glasses. Crystallization of amorphous SiO2 can be induced by implantation of Li. Insight into the crystallization process is obtained by following the associated ion movement by elastic recoil detection (ERD) and optical techniques. Implantation of 20keV H shows that saturation of implanted H-sites in fused silica occurs at about 2.2 × 1021 H/cm3 in agreement with free volume estimates of the maximum nu...
Particle manipulation with nonadiabatic ponderomotive forces

Average, or ponderomotive potentials effectively seen by particles in oscillating fields allow advanced techniques of particle manipulation inaccessible with static potentials. In strongly inhomogeneous fields the ponderomotive force is phase dependent, and the particle dynamics resembles that of a quantum object in a conservative barrier. Probabilistic transmission through a ponderomotive potential is then possible and can be used for particle beam slicing. Resonant fields can also cool and trap particles exhibiting natural oscillations (e.g., Larmor rotation), as well as transmit them asymmetrically; hence, acting as one-way walls. An approximate integral of particle motion is found for this case and a new ponderomotive potential is introduced accordingly.
Protein kinase C activity as a potential marker for colorectal neoplasia.

Protein kinase C (PKC) is a mediator of transmembrane signal transduction, important in cell growth and differentiation. Cell activation by extracellular signals is associated with a translocation of PKC from the cytosol to the membrane. We measured and compared PKC activity in cytosol and membrane fractions of normal and neoplastic colorectal tissue. Total and membrane-associated PKC activity in normal colorectal tissue was greater in patients (N=16) with colorectal cancer compared to that from patients with a normal colonoscopy (N=16),P<0.01. A similar trend was noted in PKC activity of normal colorectal tissue from patients with adenomas compared to patients with a normal colonoscopy. PKC activity (total, membrane-associated, percent membrane) was not different in neoplastic colorectal tissue compared to that of adjacent normal tissue. However, there was a considerable range of PKC activity noted in all groups, which would limit the utility of PKC activity as a marker for colorectal neoplasia.
Torsion algebraic cycles and étale cobordism

We prove that the classical integral cycle class map from algebraic cycles to etale cohomology factors through a quotient of l-adic etale cobordism over an algebraically closed field of positive characteristic. This shows that there is a strong topological obstruction for cohomology classes to be algebraic and that examples of Atiyah, Hirzebruch and Totaro also work in positive characteristic.
Fact-based data analysis and design

Abstract By focusing on the facts to be maintained in a database, we obtain a methodology for data analysis and design which is at once simpler and more powerful than other methodologies.
The Hall Effect in Single Crystals of Barium Oxide

The Hall effect has been measured as a function of temperature, between 400\ifmmode^\circ\else\textdegree\fi{}K and 800\ifmmode^\circ\else\textdegree\fi{}K, in single crystals of barium oxide using an ac system. Conduction was predominantly $N$-type. The value of $\frac{({{\ensuremath{\mu}}_{e}}^{2}\ensuremath{-}{{\ensuremath{\mu}}_{h}}^{2})}{({\ensuremath{\mu}}_{e}+{\ensuremath{\mu}}_{h})}$ was about 3 ${\mathrm{cm}}^{2}$/volt sec between 600\ifmmode^\circ\else\textdegree\fi{}K and 700\ifmmode^\circ\else\textdegree\fi{}K and varied only slightly with temperature over the entire range studied. ${\ensuremath{\mu}}_{e}$ is thought to lie between 3 and 9 ${\mathrm{cm}}^{2}$/volt sec. There was some evidence that conduction was intrinsic at the higher temperatures in the samples studied.
Assessment of voiding after sling: a randomized trial of 2 methods of postoperative catheter management after midurethral sling surgery for stress urinary incontinence in women

Objective The objective of this study was to compare the backfill standard voiding trial (SVT) that relies on the assessment of voided volume to subjective patients' evaluation of their voiding based on the assessment of the force of stream (FOS) after an outpatient midurethral sling surgery. Study Design This double-blinded randomized trial included patients undergoing an outpatient midurethral sling surgery without any other concomitant surgery. Participants were randomized to either the SVT group or to the FOS group. The primary outcome was the rate of catheterization any time up to 6 weeks after surgery. Both groups underwent the same backfill voiding trial protocol postoperatively. Measurements of the voided amount, postvoid residual, and the response to the FOS visual analog scale were collected. The criteria for passing the voiding trial in the SVT group was voiding at least two-thirds of the instilled amount; while the criteria for passing the trial in the FOS group was assessment of FOS at least 50% of the baseline, regardless of the voided volume. Participants were interviewed preoperatively and 2-4 days, 7-9 days, and 6 weeks postoperatively. All postoperative interviews included assessments of pain, tolerance of physical activity, urinary FOS, as well as satisfaction with the surgery. Validated questionnaires (Incontinence Severity Index and Urinary Distress Inventory, short form) before the surgery and 6 weeks after were used to evaluate urinary symptoms. Results A total of 108 patients were enrolled and randomized, and 6-week follow-up data were available for 102 participants (FOS 50, SVT 52). The 2 groups were similar with respect to demographic characteristics and urinary symptoms. The incidence of catheterization was also similar between the groups (FOS 13 [26%], SVT 13 [25.5%]; P = .95). Amount voided had a moderate correlation with FOS assessment (Spearman rho 0.5; P Conclusion Patient's subjective assessment of the urinary FOS correlated well with the measured voided amount and no difference in catheterization days was noted between the subjective and objective assessment of voiding. Thus subjective evaluation of the FOS is a reliable and safe method to use after outpatient midurethral surgery.
An expedient synthesis of isopropyl anisoles and veratroles

Abstract Isopropyl-substituted anisoles and veratroles were obtained in high yields (89–93 %) on the aqueous work-up of the reaction of 3-(methoxyphenyl)-2-oxopropanoic acids with iodomethane and potassium hydroxide in dimethyl sulfoxide.
Sequential self-assembly in metal-organic frameworks.

This perspective discusses the use of sequential self-assembly in the construction of metal–organic frameworks through the systematic insertion, replacement, and removal of organic structural building units. We review previous works that can be classified as such sequential self-assembly in multidimensional MOFs.
The structure of the gauge theory vacuum

Abstract The finite action Euclidean solutions of gauge theories are shown to indicate the existence of tunneling between topologically distinct vacuum configurations. Diagonalization of the Hamiltonian then leads to a continuum of vacua. The construction and properties of these vacua are analyzed. In non-abelian theories of the strong interactions one finds spontaneous symmetry breaking of axial baryon number without the generation of a Goldstone boson, a mechanism for chiral SU(N) symmetry breaking and a possible source of T violation.
A thermodynamic analysis of HYCSOS, a hydrogen conversion and storage system

Abstract A two metal hydride system for the storage, retrieval and conversion of thermal energy is described. The system functions—heating, cooling and power production—are discussed for solar energy applications. A thermodynamic analysis particularly of the conversion cycle is presented. It is concluded that solar concentrators providing heat transfer fluid temperatures of 140°C could give conversion efficiencies of 16.5%.
THE EXPRESSION OF THE FUTURE

The concept of time in relation to action finds expression in the verbal forms of a great many, although not all, languages. ‘In English we have made up our minds that all action must be conceived of in reference to three standard times’,’-the present, the past, and the future. Of these three, the devices for the expression of the future-their origin, development, and present use-receive from our grammarians the least satisfactory treatment. The common school grammars of modern English usually give as the one means of indicating future time the combination of shall and will with the infinitive form of the verb and name it the future tense.2 Some give two forms of the future tense: one for simple futurity and another for detern~imtion.~ As a matter of fact, however, the use of the auxiliaries shall and will with the infinitive is but one of several important methods of expressing the future and certainly does not deserve the title ‘the future tense’. Some other combinations having a claim to be included in an English future tense are: (a) the verb to be + prepositional infinitive. (He i s to go with the committee.) (b) the verb to be-about + prepositional infinitive. (The man is about to dive from the bridge.) (c) the verb to be + going + prepositional infinitive. (They are going to go by automobile.) Then too, the present form of the verb frequently refers to future time both in subordinate clauses and in independent sentences when some other word than the verb, or the context in general, indicates the time idea. (He returns from his trip tomorrow.) On the other hand, the use of shall and will to express determination (sometimes called ‘the emphatic future’, or ‘the colored future’, or ‘the (If it rains, I cannot go.)
THE DILEMMA OF ATTRIBUTION

I suspected that there were some members of the live audience who were somewhat apprehensive about sitting through the morning’s physics lectures. After all, there were three guys there to talk about one minus sign. If it were just two people and a plus sign, +, one could talk about the | and the other about the —. However, to my mind, this year’s awards represent or symbolize not just a minus sign but a large body of significant advances in our understanding of fundamental physics and are the work of not just three people but a great many scientists, stretching out over many years and many countries. This is really a prize for that whole community.
Origin of internal symmetry

The possibility that the internal-symmetry group is a consequence of the gauge invariance of a theory (rather than being phenomenologically chosen) is suggested. For a fully unified theory where all interactions are determined by the gauge invariance, this could come about as a consequence of spontaneous (or dynamical) breakdown. Thus the vacuum state after symmetry breakdown may preserve only a subgroup of a larger arbitrary group of the original unbroken equations. The above suggestion appears to be at least partly realized within the framework of gauge supersymmetry where the local gauge invariance determines all interactions via the field equations R/sub A B/ = lambdag/sub A B/, lambda = const. Starting with an arbitrary internal-symmetry group, we obtain general conditions to determine the remaining unbroken symmetry group when the gauge supersymmetry spontaneously breaks to a vacuum state that is invariant under a generalized global supersymmetry. For the case lambda not-equal 0, if one further assumes that the vacuum state preserves parity, these conditions uniquely determine the remaining unbroken internal-symmetry group to be the U(1) gauge group of Maxwell theory (as well as the Einstein general coordinate group). For the case lambda = 0, the internal-symmetry group is only partly determined. However,more » the condition that a spontaneous breakdown occurs automatically causes a violation of parity, and thus affords a natural origin of this phenomenon for weak interactions. The structure of the pseudo-Goldstone bosons of the theory (which are absorbed by the vector mesons of the broken gauge invariances) is determined.« less
Secular Evolution of Hierarchical Triple Star Systems

We derive octupole-level secular perturbation equations for hierarchical triple systems, using classical Hamiltonian perturbation techniques. Our equations describe the secular evolution of the orbital eccentricities and inclinations over timescales that are long compared to the orbital periods. By extending previous work done to leading (quadrupole) order to octupole level (i.e., including terms of order α3, where α ≡ a1/a2 < 1 is the ratio of semimajor axes), we obtain expressions that are applicable to a much wider range of parameters. In particular, our results can be applied to high-inclination as well as coplanar systems, and our expressions are valid for almost all mass ratios for which the system is in a stable hierarchical configuration. In contrast, the standard quadrupole-level theory of Kozai gives a vanishing result in the limit of zero relative inclination. The classical planetary perturbation theory, while valid to all orders in α, applies only to orbits of low-mass objects orbiting a common central mass, with low eccentricities and low relative inclinations. For triple systems containing a close inner binary, we also discuss the possible interaction between the classical Newtonian perturbations and the general relativistic precession of the inner orbit. In some cases we show that this interaction can lead to resonances and a significant increase in the maximum amplitude of eccentricity perturbations. We establish the validity of our analytic expressions by providing detailed comparisons with the results of direct numerical integrations of the three-body problem obtained for a large number of representative cases. In addition, we show that our expressions reduce correctly to previously published analytic results obtained in various limiting regimes. We also discuss applications of the theory in the context of several observed triple systems of current interest, including the millisecond pulsar PSR B1620-26 in M4, the giant planet in 16 Cygni, and the protostellar binary TMR-1.
Voting Behavior and Aggregate Policy Targets

The structure of the United States economy is generally thought to impose, in the short run, a trade-off between unemployment and price inflation. Regardless of the reasons for this social constraint (and opinion is widely varied on the structural relations underlying it), those who believe that monetary and fiscal policy can influence the performance of the economy along the price change and unemployment dimensions are confronted with the problem of choosing a single target. Voters are likely to have strong opinions on the matter. To the extent that these opinions systematically influence voting behavior, information regarding public preferences over unemployment-price-change targets is embedded in voting statistics.
Economic Mergers in Academe: A Discussion of Academic Mergers in Economics

Despite the sometimes intensely competitive environment in which American colleges and universities operate, relatively few institutions seem ever to go out of business. Fewer than one-half of 1% of four-year institutions disappear annually, and those few are usually absorbed into other institutions rather than liquidated. From 1965 through 1985, for example, an average of only six four-year colleges and universities (out of about 1,400) exited annually (Kwoka and Snyder). Optimal unit size in academe also has a dimension narrower than the institution, namely the department. Although biological science departments and foreign language departments occasionally combine into a larger unit or disperse themselves into smaller units, the structure of most academic departments is remarkably stable, probably much more so than comparable operating units within for-profit corporations. In view of the vast literature on the eco-
Adaptive motion mapping in pancreatic SBRT patients using Fourier transforms

Abstract Background and purpose Recent studies suggest that 4DCT is unable to accurately measure respiratory-induced pancreatic tumor motion. In this work, we assessed the daily motion of pancreatic tumors treated with SBRT, and developed adaptive strategies to predict and account for this motion. Materials and methods The daily motion trajectory of pancreatic tumors during CBCT acquisition was calculated using a model which reconstructs the instantaneous 3D position in each 2D CBCT projection image. We developed a metric (termed “Spectral Coherence,” SC) based on the Fourier frequency spectrum of motion in the SI direction, and analyzed the ability of SC to predict motion-based errors and classify patients according to motion characteristics. Results The amplitude of daily motion exceeded the predictions of pre-treatment 4DCT imaging by an average of 3.0 mm, 2.3 mm, and 3.5 mm in the AP/LR/SI directions. SC was correlated with daily motion differences and tumor dose coverage. In a simulated adaptive protocol, target margins were adjusted based on SC, resulting in significant increases in mean target D95, D99, and minimum dose. Conclusion Our Fourier-based approach differentiates between consistent and inconsistent motion characteristics of respiration and correlates with daily motion deviations from pre-treatment 4DCT. The feasibility of an SC-based adaptive protocol was demonstrated, and this patient-specific respiratory information was used to improve target dosimetry by expanding coverage in inconsistent breathers while shrinking treatment volumes in consistent breathers.
Airfoil Self-Noise Generated in a Cascade

Self-noise from fans and rotors is generated by blade boundary-layer turbulence interacting with the trailing edges of the blades. Previous theories describing this mechanism have considered only an isolated airfoil and have shown that acoustic scattering from the sharp trailing edge is responsible for the sound that propagates to the far e eld. In aeroengine applications, fans or stators have relatively high solidity, and there will be acoustic scattering from adjacent blades as well as the blade locally excited by the e ow. The theory is given for self-noise from a fan modeled as a linear cascade of semi-ine nite e at plates. The magnitude of the self-noise mechanism is compared with the e eld that would be generated by a single airfoil without adjacent blade scattering.
Coordinate families for the Schwarzschild geometry based on radial timelike geodesics

We explore the connections between various coordinate systems associated with observers moving inwardly along radial geodesics in the Schwarzschild geometry. Painleve–Gullstrand (PG) time is adapted to freely falling observers dropped from rest from infinity; Lake–Martel–Poisson (LMP) time coordinates are adapted to observers who start at infinity with non-zero initial inward velocity; Gautreau–Hoffmann time coordinates are adapted to observers dropped from rest from a finite distance from the black hole horizon. We construct from these an LMP family and a proper-time family of time coordinates, the intersection of which is PG time. We demonstrate that these coordinate families are distinct, but related, one-parameter generalizations of PG time, and show linkage to Lemaitre coordinates as well.
Laser-induced spin protection and switching in a specially designed magnetic dot: A theoretical investigation

Most laser-induced femtosecond magnetism investigations are done in magnetic thin films. Nanostructured magnetic dots, with their reduced dimensionality, present new opportunities for spin manipulation. Here we predict that if a magnetic dot has a dipole-forbidden transition between the lowest occupied molecular orbital (LUMO) and the highest unoccupied molecular orbital (HOMO), but a dipole-allowed transition between LUMO+1 and HOMO, electromagnetically induced transparency can be used to prevent ultrafast laser-induced spin momentum reduction, or spin protection. This is realized through a strong dump pulse to funnel the population into LUMO+1. If the time delay between the pump and dump pulses is longer than 60 fs, a population inversion starts and spin switching is achieved. These predictions are detectable experimentally.
An efficient synthesis of a class of heterobifunctional photo-reactive crosslinkers, labels, and probes

Abstract Aryl esters are selectively reduced with DIBAL-H in the presence of an azide functional group to provide access to 4-azido-2-alkoxybenzaldehydes in five steps with overall yields ranging from 72 to 78%. This methodology improves traditional approaches to this class of compounds, which suffer from poor overall yields (4–11%). Our approach can be used to synthesize a variety of new aryl azide cross-linkers, labels, and probes.
An ultrasonic analogue for a random laser

We describe electro-mechanical auto-oscillator which, when placed in contact with irregular acoustic cavity, can exhibit stimulated emission of ultrasound. Analytic model is constructed describing the device, which we propose as classical analogue of random laser.
Feasibility of Oral Topotecan in Previously Untreated Patients with Small-Cell Lung Cancer Ineligible for Standard Therapy

The single-agent activity of intravenous (i.v.) topotecan has been established in small-cell lung cancer (SCLC), with overall tumor responses of 39% in previously untreated patients and 11–37% in rela
Software Caching and Computation Migration in Olden

Software caching and computation migration are mechanisms that satisfy remote references by either bringing a copy of the data to the computation or moving the computation to the data. We evaluate these mechanisms usingOlden, a system that, with minimal programmer annotations, provides parallelism for C programs that use recursively defined structures, such as trees, lists, and DAGs. We demonstrate that providing both software caching and computation migration can improve the performance of these programs, and provide a compile-time heuristic that selects between them for each pointer dereference. We have implemented the heuristic in Olden on the Thinking Machines CM-5. We describe our implementation and report on experiments with eleven benchmarks.
The Stony Brook/SMARTS Atlas of (mostly) Southern Novae

We introduce the Stony Brook/SMARTS Atlas of (mostly) Southern Novae. This atlas contains both spectra and photometry obtained since 2003. The data archived in this atlas will facilitate systematic studies of the nova phenomenon and correlative studies with other comprehensive data sets. It will also enable detailed investigations of individual objects. In making the data public we hope to engender more interest on the part of the community in the physics of novae. The atlas is online at http://www.astro.sunysb.edu/fwalter/SMARTS/NovaAtlas/.
PROPERTIES AND SPATIAL DISTRIBUTION OF DUST EMISSION IN THE CRAB NEBULA

Recent infrared (IR) observations of freshly formed dust in supernova remnants have yielded significantly lower dust masses than predicted by theoretical models and measured from high-redshift observations. The Crab Nebula's pulsar wind is thought to be sweeping up freshly formed supernova (SN) dust along with the ejected gas. The evidence for this dust was found in the form of an IR excess in the integrated spectrum of the Crab and in extinction against the synchrotron nebula that revealed the presence of dust in the filament cores. We present the first spatially resolved emission spectra of dust in the Crab Nebula acquired with the Infrared Spectrograph on board the Spitzer Space Telescope. The IR spectra are dominated by synchrotron emission and show forbidden line emission from S, Si, Ne, Ar, O, Fe, and Ni. We derived a synchrotron spectral map from the 3.6 and 4.5 μm images, and subtracted this contribution from our data to produce a map of the residual continuum emission from dust. The dust emission appears to be concentrated along the ejecta filaments and is well described by an amorphous carbon or silicate grain compositions. We find a dust temperature of 55 ± 4 K for silicates and 60 ± 7 K for carbon grains. The total estimated dust mass is (1.2-12) × 10–3 M ☉, well below the theoretical dust yield predicted for a core-collapse supernova. Our grain heating model implies that the dust grain radii are relatively small, unlike what is expected for dust grains formed in a Type IIP SN.
What They Came With: Carnival and the Persistence of African Performance Aesthetics in the Diaspora

This article identifies what was on the continent as festival and ritual performance forms before the Europeans arrived and what the Africans who survived the Atlantic sea crossing came with as “pe...
High-resolution rotation curves of low surface brightness galaxies

High-resolution Halpha rotation curves are presented for five low surface brightness galaxies. These Halpha rotation curves have shapes different from those previously derived from H i observations, probably because of the higher spatial resolution of the Halpha observations. The Halpha rotation curves rise more steeply in the inner parts than the H i rotation curves, and they reach a flat part beyond about two disk scale lengths. With radii expressed in optical disk scale lengths, the rotation curves of the low surface brightness galaxies presented here and those of the high surface brightness galaxies have almost identical shapes. Mass modeling shows that the contribution of the stellar component to the rotation curves may be scaled to explain most of the inner parts of the rotation curves, albeit with high stellar mass-to-light ratios. On the other hand, well-fitting mass models can also be obtained with lower contributions of the stellar disk. These observations suggest that the luminous mass density and the total mass density are coupled in the inner parts of these galaxies.
Orthonormal bases generated by Cuntz algebras

We show how some orthonormal bases can be generated by representations of the Cuntz algebra; these include Fourier bases on fractal measures, generalized Walsh bases on the unit interval and piecewise exponential bases on the middle third Cantor set.
Permanent Income, Liquidity, and Expenditure on Automobiles: Evidence from Panel Data

Several recent papers have tested the permanent income-cum-rational expectations hypothesis using data on nondurable or semidurable consumption. We show how this approach can be extended to the case of durables. An application to panel data on automobile expenditures reveals no evidence against the permanent income hypothesis. This result is unchanged in subsamples segregated by family holdings of liquid assets.
Stable Manifolds and Homoclinic Points Near Resonances in the Restricted Three-Body Problem

The restricted three-body problem describes the motion of a massless particle under the influence of two primaries of masses 1 − µ and µ that circle each other with period equal to 2π . For small µ, a resonant periodic motion of the massless particle in the rotating frame can be described by relatively prime integers p and q, if its period around the heavier primary is approximately 2πp/q, and by its approximate eccentricity e. We give a method for the formal development of the stable and unstable manifolds asso- ciated with these resonant motions. We prove the validity of this formal development and the existence of homoclinic points in the resonant region. In the study of the Kirkwood gaps in the asteroid belt, the separatrices of the averaged equations of the restricted three-body problem are commonly used to derive analytical approximations to the boundaries of the resonances. We use the unaveraged equations to find values of asteroid eccentricity below which these approximations will not hold for the Kirkwood gaps with q/p equal to 2/1, 7/3, 5/2, 3/1, and 4/1. Another application is to the existence of asymmetric librations in the exterior resonances. We give values of asteroid eccentricity below which asymmet- ric librations will not exist for the 1/7, 1/6, 1/5, 1/4, 1/3, and 1/2 resonances for any µ however small. But if the eccentricity exceeds these thresholds, asymmetric librations will exist for µ small enough in the unaveraged restricted three-body problem.
Honest iteration schemes of randomizing algorithms

This paper further studies Blass and Gurevich's iteration schemes of randomizing algorithms for randomized reductions [BG91]. An iteration scheme of a randomizing algorithm is honest if it passes a bit to a process independently of its value. We show that if a fair iteration scheme is honest, then it is independent. This implies the previous known sufficient condition for independence in [BG91]. On the other hand, we show that for independence, honesty is not necessary.
Homogeneous pd-catalyzed enantioselective decarboxylative protonation.

General homogeneous conditions for the palladium-catalyzed synthesis of carbonyl compounds with tertiary carbon stereocenters at the α-position are reported. The highly reactive catalyst tolerates a variety of substrate substitution and functionality, and generates enantioenriched cyclic ketones from racemic allyl β-ketoester starting materials.
A Wave Theory for Non-imaging Concentrators

Abstract An expression is found for the propagation of the radiance function for light in any state of coherence through a concentrator which can be represented by a linear, stationary optical system. For light from a quasi-homogeneous source this expression can be somewhat simplified by an approximation. It is shown that the radiance function is invariant for a large class of optical systems. Finally it is shown that fundamental limitations for the concentration of light follow from the uncertainty principle and the second law of thermodynamics, which apply quite generally. These relations show why quasi-homogeneous light (i.e. light from thermal sources) cannot be concentrated as well as light from some other sources (such as light from a laser).
Spin‐Center Shift (SCS) – A Versatile Concept in Biological and Synthetic Chemistry

Reactions involving radical intermediates are nowadays an inherent part of organic chemistry and the impressive progress in this area in recent decades has contributed to the understanding of many biological processes and provided many valuable methods for preparative chemists. By analyzing the mechanism of some biochemical transformations involving radical intermediates a common principle emerges. If at the atom adjacent to an α-hydroxy or α-alkoxy radical a leaving group is tethered a rapid elimination takes place and the spin density is shifted by one atom. This concept, called the spin-center shift (SCS), considerably extends the scope of some radical reactions. This microreview provides an overview of both biochemical examples of the SCS concept and synthetic applications. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Persistent current in metals with a large dephasing rate

In a weakly disordered metal electron interactions are responsible for both decoherence of the quasi-particles as well as for quantum corrections to thermodynamic properties. We consider electrons which are interacting with two-level-systems. We show that the two-level-systems enhance the average equilibrium (“persistent”) current in an ensemble of mesoscopic rings. The result supports the recent suggestion that two puzzles in mesoscopic physics may be related: The low temperature saturation of the dephasing time and the high persistent current in rings.
Enantioselective parallel synthesis using polymer-supported chiral Co(salen) complexes.

The kinetic resolution of epoxides with phenols catalyzed by a polymer-supported Co(salen) complex is applied to the first enantioselective catalytic synthesis of parallel libraries. The corresponding 1-aryloxy-2-alcohols are obtained in high yield, purity, and enantiomeric excess. Further elaboration with diversity elements provides highly efficient access to important classes of pharmacologically active compounds.
Selective reduction of alkynes to Z-alkenes using hydrosilane functions immobilized on silica gel

Abstract A solid reagent consisting of hydrosilane functions immobilized on the surface of silica gel was used in conjunction with a acetic acid and tetrakis(triphenylphosphine)palladium(0) catalyst to effect the reduction of alkynes to Z-olefins. Simple filtration provides a convenient means for the reaction workup and isolation of products.
Treating Opportunistic Infections among HIV-Exposed and Infected Children: Recommendations from CDC, the National Institutes of Health, and the Infectious Diseases Society of America

In 2001, CDC, the National Institutes of Health, and the Infectious Diseases Society of America convened a working group to develop guidelines for therapy of human immunodeficiency virus (HIV)-associated opportunistic infections to serve as a companion to the Guidelines for Prevention of Opportunistic Infections Among HIV-Infected Persons. In recognition of unique considerations related to HIV infection among infants, children, and adolescents, a separate pediatric working group was established. Because HIV-infected women coinfected with opportunistic pathogens might be more likely to transmit these infections to their infants than women without HIV infection, guidelines for treating opportunistic pathogens among children should consider treatment of congenitally acquired infections among both HIV-exposed but uninfected children and those with HIV infection. In addition, the natural history of opportunistic infections among HIV-infected children might differ from that among adults. Compared with opportunistic infections among HIV-infected adults, which are often caused by reactivation of pathogens acquired before HIV infection when host immunity was intact, opportunistic infections among children often reflect primary acquisition of the pathogen and, among children with perinatal HIV infection, infection acquired after HIV infection has been established and begun to compromise an already immature immune system. Laboratory diagnosis of opportunistic infections can be more difficult with children. Finally, treatment recommendations should consider differences between adults and children in terms of drug pharmacokinetics, dosing, formulations, administration, and toxicities. This report focuses on treatment of opportunistic infections that are common in HIV-exposed and infected infants, children, and adolescents in the United States.
The token-skipping channel access scheme for bus networks

Abstract A major disadvantage of the standard token-bus network architecture is the delay involved in passing the token through idle stations. A modified token-passing scheme is described that minimizes this overhead by bypassing idle stations. This scheme requires very little additional hardware over the proposed IEEE 802.4 channel-access protocol and has this proposed standard protocol as one of its limiting cases. Simulation studies of this scheme show significant improvement of delay-throughput characteristics for practical load ranges. For example, for throughputs up to about 65%, a network with 100 nodes with Poisson arrivals and symmetric load distribution among nodes has a mean delay of less than half that of a similar network using the conventional token-passing scheme. Under asymmetric load distribution among nodes, even higher speedup factors can be achieved.
Stereochemistry of directed lithiation of 1,1′-bis(methoxymethyl)ferrocene

Abstract 1,1′-Bis(methoxymethyl)ferrocene undergoes stereoselective directed dilithiation in the presence of t -butyllithium. Evidence is presented to establish the stereochemistry of the products.
Improved mixing time bounds for the thorp shuffle

E. Thorp introduced the following card shuffling model. Suppose the number of cards is even. Cut the deck into two equal piles, then interleave them as follows. Choose the first card from the left pile or from the right pile according to the outcome of a fair coin flip. Then choose from the other pile. Continue this way, flipping an independent coin for each pair, until both piles are empty. We prove an upper bound of Od3 for the mixing time of the Thorp shuffle with 2d cards, improving on the best known bound of Od4. As a consequence, we obtain an improved bound on the time required to encrypt a binary message of length d using the Thorp shuffle.
OutSMarTing the Social Security Crisis

We present a rule-of-thumb consumption model with participation in a ``Save More TomorrowTM'' (SMarT) plan, and we analytically derive the fraction of life-cycle wage increases that must be saved to offset a reduction in social security benefits resulting from an aging population (holding taxes fixed and maintaining a balanced social security budget). We find that this ``critical'' SMarT rate is quite low, and much lower than the rate that participants actually used in real-world pilot implementations. This finding generally continues to hold even if wage growth is slow, even if the real return on private saving is low or extremely volatile, and even if enrollment in a SMarT plan is delayed until late in the life cycle. Moreover, we show that participation in a SMarT plan can improve lifetime utility.
A new reaction in organosilicon chemistry: the oxidative ring closure of allylsilanes with ceric ammonium nitrate

Abstract Allylsilanes containing heteroatom nucleophiles yield cyclic products when treated with (NH 4 ) 2 Ce(NO 3 ) 6 . For example, hydroxy and amido-containing allylsilanes yield the corresponding tetrahydrofuran, tetrahydropyran, and piperidine analogs. These reactions and their application to natural product synthesis will be discussed.
Posttraumatic stress disorder: A state-of-the-science review

This article reviews the state-of-the-art research in posttraumatic stress disorder (PTSD) from several perspectives: (1) Sex differences: PTSD is more frequent among women, who tend to have different types of precipitating traumas and higher rates of comorbid panic disorder and agoraphobia than do men. (2) Risk and resilience: The presence of Group C symptoms after exposure to a disaster or act of terrorism may predict the development of PTSD as well as comorbid diagnoses. (3) Impact of trauma in early life: Persistent increases in CRF concentration are associated with early life trauma and PTSD, and may be reversed with paroxetine treatment. (4) Imaging studies: Intriguing findings in treated and untreated depressed patients may serve as a paradigm of failed brain adaptation to chronic emotional stress and anxiety disorders. (5) Neural circuits and memory: Hippocampal volume appears to be selectively decreased and hippocampal function impaired among PTSD patients. (6) Cognitive behavioral approaches: Prolonged exposure therapy, a readily disseminated treatment modality, is effective in modifying the negative cognitions that are frequent among PTSD patients. In the future, it would be useful to assess the validity of the PTSD construct, elucidate genetic and experiential contributing factors (and their complex interrelationships), clarify the mechanisms of action for different treatments used in PTSD, discover ways to predict which treatments (or treatment combinations) will be successful for a given individual, develop an operational definition of remission in PTSD, and explore ways to disseminate effective evidence-based treatments for this condition.
Palladium-catalyzed α-arylation of benzylic phosphine oxides.

A novel approach to prepare diarylmethyl phosphine oxides from benzyl phosphine oxides via deprotonative cross-coupling processes (DCCP) is reported. The optimization of the reaction was guided by High-Throughput Experimentation (HTE) techniques. The Pd(OAc)2/Xantphos-based catalyst enabled the reaction between benzyl diphenyl or dicyclohexyl phosphine oxide derivatives and aryl bromides in good to excellent yields (51–91%).
Experimental Study of Surface and Interior Combustion Using Composite Porous Inert Media

Combustion using silicon carbide coated, carbon-carbon composite porous inert media (PIM) was investigated. Two combustion modes, surface and interior, depending upon the location of flame stabilization, were considered. Combustion performance was evaluated by measurements of pressure drop across the PIM, emissions of NO x and CO, and the lean blow-off limit. Data were obtained for the two combustion modes at identical conditions for a range of reactant flowrates, equivalence ratios, and pore sizes of the PIM. Results affirm PIM combustion as an effective method to extend the blow-off limit in lean premixed combustion.
Acyclic 1,4-stereocontrol via reductive 1,3-transpositions.

One-pot reduction/allylic diazene rearrangement of lactic acid- and mandelic acid-derived α,β-unsaturated tosyl hydrazones leads to 1,4-syn- or 1,4-anti-E-2-alkenyl arrays in high yield and diastereoselectivity. Either the syn or the anti diastereomer can be prepared by choosing the appropriate alkene stereoisomer of the hydrazone. The E-alkenes led to the 1,4-syn isomers, while the Z-alkenes led to the 1,4-anti isomers, both with ≥20:1 diastereoselectivity.
An Examination of the Scope and Stereochemistry of the Ireland–Claisen Rearrangement of Boron Ketene Acetals

The Ireland-Claisen rearrangement of boron ketene acetals is described. The boron ketene acetal intermediates are formed through a soft enolization that obviates the use of strong bases and the intermediacy of alkali metal enolates. Yields and diastereoselectivities of these rearrangements are very sensitive to the choice of boron reagent, even among those that have been shown to effect quantitative formation of boron ketene acetals from esters. The rearrangement occurs at room temperature for all substrates with generally high levels of stereoselectivity. In contrast to previous reports using boron triflates, the use of a commercially available boron iodide reagent allows for a wider substrate scope that extends to propionates and arylacetates, as well as the previously described α-oxygenated esters. This work also provides insight into the dynamic nature of boron ketene acetals and the ramifications of this behavior for reactions in which they are intermediates.
Computational Investigation of Circular-to-Rectangular Transition Ducts

A study demonstrating that flows inside transition ducts with unusual geometry can be analyzed by employing proper selections of a Navier-Stokes code, grid topology, and turbulence modeling is presented. Based on comparison between existing experimental data and the computed results for the same configurations, reasonable agreements were obtained for wall static pressure in the transition duct. Static pressure comparisons in the supersonic nozzle section were excellent, as well as agreement between computed and measured mass flow and thrust performance.
LIMIT CYCLE OSCILLATIONS OF DELTA WING MODELS IN LOW SUBSONIC FLOW

A nonlinear, aeroelastic analysis of a low aspect, delta wing modeled as a plate of constant thickness demonstrates that limit cycle oscillations (LCO) of the order of the plate thickness are possible. The structural nonlinearity arises from double bending in both the chordwise and spanwise directions. The present results using a vortex lattice aerodynamic model for a low Mach number flow complement earlier studies for rectangular wing platforms that showed similar qualitative results. The theoretical results for the flutter boundary (beyond which LCO occurs) have been validated by comparison to the experimental data reported by other investigators for low aspect ratio delta wings. Also the limit cycle oscillations found experimentally by previous investigators (but not previously quantified prior to the present work) are consistent with the theoretical results reported here. Reduced order aerodynamic and structural models are used to substantially decrease computational cost with no loss in accuracy. Without the use of reduced order models, calculations of the LCO would be impractical. A wind tunnel model is tested to provide a quantitative experimental correlation with the theoretical results for the LCO response itself.
Interpretation of Data Obtained with Spectrophotometers of the Polarizing Type

Many spectrophotometers utilize polarizing prisms and determine the reflection factor of the sample by plane polarized light. In general, the reflection factor of the sample is independent of the azimuth of the plane of polarization but there are some materials, notably textiles, for which the reflection factor depends upon the azimuth. It can be shown mathematically that, if the reflection factor is determined for two azimuths at right angles to one another, the arithmetic average of the two values is the reflection factor for ordinary, or unpolarized light. This is true regardless of the azimuths selected. Experimental data are presented which indicate the applicability of this principle to the measurement of the color of textile fabrics.