cssi/SciSciGPT-SciSciNet huggingface dataset:
Defining and Estimating Intervention Effects for Groups that will Develop an Auxiliary Outcome

It has recently become popular to define treatment effects for subsets of the target population characterized by variables not observable at the time a treatment decision is made. Characterizing and estimating such treatment effects is tricky; the most popular but naive approach inappropriately adjusts for variables affected by treatment and so is biased. We consider several appropriate ways to formalize the effects: principal stratification, stratification on a single potential auxiliary variable, stratification on an observed auxiliary variable and stratification on expected levels of auxiliary variables. We then outline identifying assumptions for each type of estimand. We evaluate the utility of these estimands and estimation procedures for decision making and understanding causal processes, contrasting them with the concepts of direct and indirect effects. We motivate our development with examples from nephrology and cancer screening, and use simulated data and real data on cancer screening to illustrate the estimation methods.
ENDPOINT BILINEAR RESTRICTION THEOREMS FOR THE CONE, AND SOME SHARP NULL FORM ESTIMATES

Recently Wolff [25] obtained a nearly sharp \(L^2\) bilinear restriction theorem for bounded subsets of the cone in general dimension. We obtain the endpoint of Wolff's estimate and generalize to the case when one of the subsets is large. As a consequence, we are able to deduce some nearly-sharp \(L^p\) null form estimates.
Network deconvolution as a general method to distinguish direct dependencies in networks

Recognizing direct relationships between variables connected in a network is a pervasive problem in biological, social and information sciences as correlation-based networks contain numerous indirect relationships. Here we present a general method for inferring direct effects from an observed correlation matrix containing both direct and indirect effects. We formulate the problem as the inverse of network convolution, and introduce an algorithm that removes the combined effect of all indirect paths of arbitrary length in a closed-form solution by exploiting eigen-decomposition and infinite-series sums. We demonstrate the effectiveness of our approach in several network applications: distinguishing direct targets in gene expression regulatory networks; recognizing directly interacting amino-acid residues for protein structure prediction from sequence alignments; and distinguishing strong collaborations in co-authorship social networks using connectivity information alone. In addition to its theoretical impact as a foundational graph theoretic tool, our results suggest network deconvolution is widely applicable for computing direct dependencies in network science across diverse disciplines.
HUBBLE SPACE TELESCOPE SURVEY OF INTERSTELLAR HIGH-VELOCITY SI III

We describe an ultraviolet spectroscopic survey of interstellar high-velocity cloud (HVC) absorption in the strong ?1206.500 line of Si III using the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. Because the Si III line is 4-5 times stronger than O VI ?1031.926, it provides a sensitive probe of ionized gas down to column densities N Si III 5 ? 1011 cm?2 at Si III equivalent width 10 m?. We detect high-velocity Si III over 91% ? 4% of the sky (53 of 58 sight lines); 59% of the HVCs show negative local standard of rest velocities. The mean HVC column density per sight line is log N Si III = 13.19 ? 0.45, while the mean for all 90 velocity components is 12.92 ? 0.46. Lower limits due to Si III line saturation are included in this average, so the actual mean/median values are even higher. The Si III appears to trace an extensive ionized component of Galactic halo gas at temperatures 104.0-4.5 K indicative of a cooling flow. Photoionization models suggest that typical Si III absorbers with 12.5 < log N Si III < 13.5 have total hydrogen column densities N H 1018-1019 cm?2 for gas of hydrogen density n H 0.1 cm?3 and 10% solar metallicity. With typical neutral fractions N H I /N H 0.01, these HVCs may elude even long-duration 21 cm observations at Arecibo, the EVLA, and other radio facilities. However, if Si III is associated with higher density gas, n H ? 1 cm?3, the corresponding neutral hydrogen could be visible in deep observations. This reservoir of ionized gas may contain 108 M ? and produce a mass infall rate of 1 M ? yr?1 to the Galactic disk.
HIV screening in health care settings: public health and civil liberties in conflict?

On September 22 2006 the Center for Control and Prevention (CDC) issued a sweeping revision of its guidelines for human immunodeficiency virus (HIV) screening in health care settings that reversed a decade-old approach to AIDS policy. Previous guidelines recommended HIV testing only for persons at high risk or in health care settings with high HIV prevalence which reflected a civil liberties approach that constrained testing with costly cumbersome procedures for pretest counseling and written informed consent. Health care professionals often did not perform HIV screening due to financial or administrative burdens or because conducting risk assessments or discovering HIV prevalence in their facilities was impractical. The new guidelines which apply to all health care institutions in the public and private sectors (eg emergency departments inpatient services public health and community clinics primary care and correctional health care) represent a radical departure. The CDC now recommends HIV screening for all individuals aged 13 to 64 years as a part of routine medical care irrespective of lifestyle perceived risk or local HIV prevalence. The recommendations incorporate a concept known as "opt-out" testing which notifies all patients that testing will be performed unless an individual explicitly declines. Although the CDC guidelines do not explicitly indicate how patients should be notified about testing separate written informed consent would no longer be required but rather general consent for medical care would be sufficient. Similarly counseling would not be required with HIV diagnostic testing or as part of HIV screening programs. (excerpt)
Eliminating the U.S. drug lag: Implications for drug safety

An increase in new drugs first launched in the U.S. and shorter lags between first global drug launch and U.S. approval indicate that the U.S. drug lag has declined. This paper examines the impact of these changes on drug safety using adverse drug reaction data for FDA-approved drugs in 1990 to 2004. Results show two different effects. First, drugs having longer U.S. launch lags (more foreign market experience) have fewer post approval drug risks compared to drugs with shorter launch lags. This result implies that foreign market experience prior to U.S. entry provides information to help alleviate drug-related risks for U.S. patients. Second, drugs that are first launched in the U.S. have fewer serious drug reactions compared to those that were first launched abroad. This result is surprising, and may suggest that first U.S. drug launch signals information about unobserved application quality, which translates into lower post approval drug risks.
Inelastic neutron scattering from anisotropic superconductors

Abstract The magnetic fluctuation spectra are calculated for various phases of anisotropic superconductors. For small values of the Coulomb repulsion, the spectra show power law frequency dependencies due to the nodes in the superconducting order parameter. For larger strengths of the Coulomb interaction low energy critically damped collective excitations develop from the density of states in the gap. Both singlet and triplet superconducting phases can support anti-ferromagnetic fluctuations.
Effect of generic cigarettes on US cigarette demand and smuggling

Abstract This paper examines the effects of generic cigarettes on overall cigarette demand and smuggling, and studies influences of casual and organized smuggling for the United States. Generic cigarettes lower the price elasticity and diminish the effect of formal smuggling.
Einstein and the Early Theory of Superconductivity, 1919–1922

Einstein's early thoughts about superconductivity are discussed as a case study of how theoretical physics reacts to experimental findings that are incompatible with established theoretical notions. One such notion that is discussed is the model of electric conductivity implied by Drude's electron theory of metals, and the derivation of the Wiedemann-Franz law within this framework. After summarizing the experimental knowledge on superconductivity around 1920, the topic is then discussed both on a phenomenological level in terms of implications of Maxwell's equations for the case of infinite conductivity, and on a microscopic level in terms of suggested models for superconductive charge transport. Analyzing Einstein's manuscripts and correspondence as well as his own 1922 paper on the subject, it is shown that Einstein had a sustained interest in superconductivity and was well informed about the phenomenon. It is argued that his appointment as special professor in Leiden in 1920 was motivated to a considerable extent by his perception as a leading theoretician of quantum theory and condensed matter physics and the hope that he would contribute to the theoretical direction of the experiments done at Kamerlingh Onnes' cryogenic laboratory. Einstein tried to live up to these expectations by proposing at least three experiments on the phenomenon, one of which was carried out twice in Leiden. Compared to other theoretical proposals at the time, the prominent role of quantum concepts was characteristic of Einstein's understanding of the phenomenon. The paper concludes with comments on Einstein's epistemological reflections on the problem.
Extensions of homogeneous coordinate rings to $A_ \infty$-algebras

We study $A_\infty$-structures extending the natural algebra structure on the cohomology of $\oplus_{n\in\mathbb{Z}} L^n$, where $L$ is a very ample line bundle on a projective $d$-dimensional variety $X$ such that $H^i(X,L^n)=0$ for 0 > i > d and all $ n \in \mathbb{Z}$. We prove that there exists a unique such nontrivial$A_{\infty}$-structure up to a strict $A_{\infty}$-isomorphism (i.e., an $A_{\infty}$-isomorphism with the identity as the first structure map) and rescaling. In the case when $X$ is a curve we also compute the group of strict $A_{\infty}$-automorphisms of this $A_{\infty}$-structure.
Analytic solution for a cruising plane change maneuver

The analytical solution for a cruising plane change maneuver predicts the plane change during a constant altitude, velocity, and angle-of-attack turn. Thrust balances drag and bank angle varies with mass to provide inplane equilibrium. The solution predicts the impulsive plane change and corrections for finite arc length and noncircular velocity. Test cases show that inclination change predictions approximate numerically integrated results by 1%. The accuracy of predicting changes in longitude of the ascending node depends on the initial inclination, with prediction errors of 1% for polar orbits. The solution's derivatives provide the initial argument of latitude, velocity, and angle of attack that maximize the plane change.
A maximum likelihood method for latent class regression involving a censored dependent variable

The standard tobit or censored regression model is typically utilized for regression analysis when the dependent variable is censored. This model is generalized by developing a conditional mixture, maximum likelihood method for latent class censored regression. The proposed method simultaneously estimates separate regression functions and subject membership in K latent classes or groups given a censored dependent variable for a cross-section of subjects. Maximum likelihood estimates are obtained using an EM algorithm. The proposed method is illustrated via a consumer psychology application.
PAIR-STARVED PULSAR MAGNETOSPHERES

We propose a simple analytic model for the innermost (within the light cylinder of canonical radius, approx. c/Omega) structure of open-magnetic-field lines of a rotating neutron star (NS) with relativistic outflow of charged particles (electrons/positrons) and arbitrary angle between the NS spin and magnetic axes. We present the self-consistent solution of Maxwell's equations for the magnetic field and electric current in the pair-starved regime where the density of electron-positron plasma generated above the pulsar polar cap is not sufficient to completely screen the accelerating electric field and thus establish thee E . B = 0 condition above the pair-formation front up to the very high altitudes within the light cylinder. The proposed mode1 may provide a theoretical framework for developing the refined model of the global pair-starved pulsar magnetosphere.
The Interaction Between Chronic Stress and Pregnancy: Preterm Birth from A Biobehavioral Perspective

Women's health care providers are increasingly aware that chronic stressors—such as poverty, ongoing perceived stress and anxiety, intimate partner violence, and experiences of racism—are associated with an increased incidence of preterm birth in the United States. It is important to increase our understanding of the explanatory pathways involved in these associations. This article discusses the concepts of stress, chronic stress response, allostatic load, the physiology of labor initiation, and the pathophysiologic interactions that may contribute to the occurrence of chronic stress-related preterm birth. Implications for future research and interventions are explored.
The synthetic potential of graphite-catalyzed alkylation

Unmodified graphite is introduced as a mild catalyst for alkylation of aromatic compounds and primary alcohols, applicable when utilization of strong Lewis acids is not feasible. The electrophilic intermediate has a significant carbocationic character and can be formed on a partially rate-limiting step.
Macroeconomic changes and mortality in Mexico

While previous studies examine how the business cycle affects mortality in developed countries, less is known about this relationship in developing countries. In this paper, we investigate whether the procyclical nature of mortality in developed countries found by Ruhm (Q J Econ 115(2):617–650, 2000) and others is also present in Mexico. We assemble a unique panel data set that contains state-level data on mortality rates by age and cause of death, GDP per capita, and socioeconomic status. We find that for Mexico total mortality rates are procyclical, with the largest impact on those aged 20–49. While these findings are similar to those in Ruhm (Q J Econ 115(2):617–650, 2000), the effects of business cycles on mortality rates differ for several specific causes of death. These results suggest that whereas total mortality may be procyclical in both developed and developing countries, significant differences may exist for some causes of death.
Quantum manifestations of classical chaos in a Fermi accelerating disk

Abstract We study the classical and quantum mechanics of a two-dimensional version of a Fermi accelerator. The model consists of a free particle that collides elastically with the walls of a circular disk with the radius varying periodically in time. A complete quantum mechanical solution of the problem is possible for a specific choice of the time-periodic oscillating radius. The quasi-energy spectral properties of the model are obtained from direct evaluation of finite-dimensional approximations to the time evolution operator. As the scaled ħ is changed from large to small the statistics of the Quasienergy Eigenvalues (QEE) change from Poisson to circular orthogonal ensemble (COE). Different statistical tests are used to characterize this transition. The transition of the Quasienergy Eigenfunctions (QEF) is also studied using the χ2 test with ν degrees of freedom. The Porter-Thomas distribution is shown to apply in the COE regime, while the Poisson regime does not fit the χ2 test with ν = 0. We find that the Poisson regime is associated with exponentially localized QEF whereas the eigenfunctions are extended in the COE regime. To make a direct comparison between the classical and quantum solutions we change the representation of the model to one in which the boundary is fixed and the Hamiltonian acquires a quadratic term with a time-periodic frequency. We then carry out a successful comparison between specific classical phase space surface-of-section solutions and their corresponding quasi-energy eigenfunctions in the Husimi representation.
Resolving ambiguities to create a natural computer-based sketching environment

Current computer-based design tools for mechanical engineers are not tailored to the early stages of design. Most designs start as pencil and paper sketches, and are entered into CAD systems only when nearly complete. Our goal is to create a kind of "magic paper" capable of bridging the gap between these two stages. We want to create a computer-based sketching environment that feels as natural as sketching on paper, but unlike paper, understands a mechanical engineer's sketch as it is drawn. One important step toward realizing this goal is resolving ambiguities in the sketch--- determining, for example, whether a circle is intended to indicate a wheel or a pin joint---and doing this as the user draws, so that it doesn't interfere with the design process. We present a method and an implemented program that does this for freehand sketches of simple 2-D mechanical devices.
SYNTHESIS OF POLYMERIZED N-UNDECYLENYL-L-AMINOACID AND N-UNDECYLENYL-L-PEPTIDE DERIVATIVES

Abstract Micelle forming polymerized N-Undecylenyl-L-aminoacid and N-Undecylenyl-L-peptide derivatives have been obtained. These compounds are effective as pseudostationary phases in electrokinetic capillary electrophoresis for racemate resolution. Synthetic procedures are described in detail, as well as preliminary analytical data comparing aminoacid derivatives and an aminoacid derivative with a peptide derivative.
JAPANESE CONSUMERS: WHAT FOREIGN MARKETERS SHOULD KNOW

Through a synthesis of research results on Japanese consumer behaviour, this paper offers conclusions about the Japanese marketplace. Insights provided on Japanese consumers may prove useful to marketers contemplating entry into Japan.
Testing scalar-tensor gravity using space gravitational-wave interferometers

We calculate the bounds which could be placed on scalar-tensor theories of gravity of the Jordan, Fierz, Brans and Dicke type by measurements of gravitational waveforms from neutron stars (NS) spiraling into massive black holes (MBH) using LISA, the proposed space laser interferometric observatory. Such observations may yield significantly more stringent bounds on the Brans-Dicke coupling parameter $\ensuremath{\omega}$ than are achievable from solar system or binary pulsar measurements. For NS-MBH inspirals, dipole gravitational radiation modifies the inspiral and generates an additional contribution to the phase evolution of the emitted gravitational waveform. Bounds on $\ensuremath{\omega}$ can therefore be found by using the technique of matched filtering. We compute the Fisher information matrix for a waveform accurate to second post-Newtonian order, including the effect of dipole radiation, filtered using a currently modeled noise curve for LISA, and determine the bounds on $\ensuremath{\omega}$ for several different NS-MBH canonical systems. For example, observations of a ${1.4M}_{\ensuremath{\bigodot}}$ NS inspiraling to a ${10}^{3}{M}_{\ensuremath{\bigodot}}$ MBH with a signal-to-noise ratio of 10 could yield a bound of $\ensuremath{\omega}g240000,$ substantialy greater than the current experimental bound of $\ensuremath{\omega}g3000.$
The influence of the formative dental organs on the growth of the bones of the face

Abstract In comparing the results of these experiments on the rodent, the carnivora, and the omnivorous animals, one is struck with the fact that there is one common factor which applies to all these induced deformations. It is that there is an arrest in the growth of the facial bones on the side and in the direction in which the experimented-on teeth would normally grow. In the rat, the persistently growing incisor grows in the forward direction, and the resulting deformity is in the horizontal plane. In the cat, the permanent maxillary teeth grow in a downward direction and the arrest was in a vertical plane; while in the pig, the growth direction of the experimented-on molars would have been both forward and downward and the arrest in growth was in both the horizontal and vertical plane. These studies furthermore show that the erupting teeth play an important part in the building of their own scaffold—the bones of the face. It must also be appreciated that the same underlying principles apply to the higher animals including man. Indeed, these experiments point to the fact that the developing dentition, regarded as a unit, is a center of growth of the facial skeleton and influences to no small degree the growth of the base of the eranium. It is hoped that the student of growth will regard this growth power which we have isolated and studied apart from the other growth influences of enough importance as to open up a new chapter in the study of the mechanism which transforms the face of the child to the adult. Be this as it may, throughout these investigations, though essentially of a biologic nature, a diligent search has nevertheless been going on for the hidden causes of the deformities of these bony structures. It must be realized that any influence which retards the power we are studying has a deforming influence on the facial skeleton. One, therefore, can more clearly appreciate how the pernicious influence of deficiency diseases, the endocrine disturbances or other serious diseases which attack the child, retard the growth influence of the twenty temporary and thirty-two developing permanent teeth as they journey from their crypts to their normal place in the dental arches. Thus we are continuing our search for the causes of the arrest in the growth of these bony structures with an enlarged vision.
Exploring the Spectrum of QCD Using a Space-Time Lattice

Some past and ongoing explorations of the spectrum of QCD using Monte Carlo simulations on a space-time lattice are described. Glueball masses in the pure-gauge theory are reviewed, and the energies of gluonic excitations in the presence of a static quark-antiquark pair are discussed. Current efforts to compute the baryon spectrum using extended three-quark operators are also presented, emphasizing the need to use irreducible representations of the cubic point group to identify spin quantum numbers in the continuum limit.
A near-infrared analysis of the submillimeter background and the cosmic star-formation history

We use new deep NIR and MIR observations to analyze the 850 ?m image of the GOODS-N region. We show that much of the submillimeter background is picked out by sources with H(AB) or 3.6 ?m(AB) < 23.25 (1.8 ?Jy). These sources contribute an 850 ?m background of 24 ? 2 Jy deg-2. This is a much higher fraction of the measured background (31-45 Jy deg-2) than is found with current 20 cm or 24 ?m samples. Roughly one-half of these NIR-selected sources have spectroscopic identifications, and we can assign robust photometric redshifts to nearly all of the remaining sources using their UV to MIR SEDs. We use the redshift and spectral type information to show that a large fraction of the 850 ?m background light comes from sources with z = 0-1.5 and that the sources responsible have intermediate spectral types. Neither the elliptical galaxies, which have no star formation, nor the bluest galaxies, which have little dust, contribute a significant amount of 850 ?m light, despite the fact that together they comprise approximately half of the galaxies in the sample. The redshift distribution of the NIR-selected 850 ?m light lies well below that of the much smaller amount of light traced by the more luminous, radio-selected submillimeter sources. We therefore require a revised star formation history with a lower star formation rate at high redshifts. We use a stacking analysis of the 20 cm light in the NIR sample to show that the star formation history is relatively flat down to z ~ 1 and that half of the total star formation occurs at z < 1.4.
A simplified routine assay for urinary 3-methoxy-4-hydroxyphenylglycol

Urinary 3-methoxy-4-hydroxyphenylglycol (MHPG) level may provide us with a biochemical index for central noradrenergic activity. Previous methods for assaying MHPG in urine often lacked specificity, sensitivity, cost-effectiveness or convenience. We now describe a simplified routine assay for urinary MHPG by high-pressure liquid chromatography using electrochemical detection. For convenience and cost-effectiveness within a typical batch assay of total MHPG, 0.5 mL of urine sample, 50 μL of glusulase and 4 μg iso-vanillyl alcohol (internal standard) were used to hydrolyze conjugated MHPG at 37 °C overnight. Alternatively, for a same-day operation, it is efficient to hydrolyze the sample at 50 °C for 3 hours. Each sample was separated isocratically on a reversed-phase column (Ultracarb 5 ODS) at 25 °C with the flow rate at 1 mL/min. Intra- and inter-assay coefficients of variation were found to be 4.0% (n=10) and 5.0% (n=27), respectively, for MHPG at a mean concentration of 1.9 mg/L. Sulfatase or glucuronidase can be substituted for glusulase to obtain either sulfate- or glucuronide-conjugated MHPG. This procedure requires smaller sample amounts and less preparation time without compromising sensitivity and reproducibility.
The Chandra Deep Field North Survey. XV. Optically Bright, X-Ray-Faint Sources*

We have analyzed optically bright, X-ray?faint [OBXF; i.e., log (fX/fR)-2] sources identified in an 178.9 arcmin2 area having high exposure (greater than 1500 ks) within the Chandra Deep Field North 2 Ms survey. We find 43 OBXF sources in this area, making up ?15% of the X-ray sources above a 0.5?2 keV flux of ?2.3 ? 10-17 ergs cm-2 s-1. We present spectroscopic identifications for 42 of the OBXF sources and optical spectra for 25, including five previously unpublished redshifts. Deep optical imaging data (either Hubble Space Telescope [HST] or ground-based) are presented for all the OBXF sources; we measure the optical morphologies of the 20 galaxies having HST imaging data. The OBXF population consists mainly of normal and starburst galaxies detected out to cosmologically significant distances (i.e., to a median redshift of z = 0.297 and a full redshift range z = 0.06?0.845). This is notable since these distances equate to look-back times of up to ?8 Gyr; we are thus provided with a window on the X-ray emission from galaxies at redshifts much closer to the cosmic star formation peak than was possible prior to the Chandra X-Ray Observatory. The X-ray luminosity distribution of OBXF sources extends to higher luminosity than does that of normal galaxies, indicating that a significant fraction are likely dominated by low-luminosity active galactic nuclei or vigorous star formation. The lowest redshift galaxies (z ? 0.06?0.2) have very low X-ray?to?optical flux ratios [i.e., log (fX/fR) -3], which are consistent with those of normal galaxies in the local universe. By combining the detected X-ray counts, we find the average OBXF X-ray spectrum to be consistent with a ? ? 2.0 power law. The 0.5?2 keV log N?log S for the OBXF galaxies is much steeper (? ? -1.7) than for the general X-ray source population. Indeed, the number of OBXF sources has doubled between the 1 and 2 Ms surveys, rising sharply in numbers at faint fluxes. The extragalactic OBXF sources are found to contribute ?1%?2% of the soft extragalactic X-ray background. We report on the discovery of five candidate off-nuclear ultraluminous X-ray sources (LX 1039 ergs s-1) with z ? 0.1?0.2 within the OBXF population. These sources are ultraluminous in that they are typically more X-ray luminous than, e.g., Eddington-limited accretion onto stellar-mass black holes; these sources are found to dominate the X-ray emission of their host galaxies.
The Lower Main Sequence and the Orbital Period Distribution of Cataclysmic Variable Stars

The color-magnitude diagram of the lower main sequence, as measured from a volume-limited sample of nearby stars, shows an abrupt downward jump between MV ~ 12 and 13. This jump indicates that the observed mass-radius relationship steepens between 0.3 and 0.2 M☉, but theoretical models show no such effect. It is difficult to isolate the source of this disagreement: the observational mass-radius relationship relies upon transformations that may not be sufficiently accurate, while the theoretical relationship relies upon stellar models that may not be sufficiently complete, particularly in their treatment of the complex physics governing the interior equation of state. If the features in the observationally derived mass-radius relationship are real, their existence provides a natural explanation for the well-known gap in the orbital period distribution of cataclysmic variables. This explanation relies only upon the observed mass-radius relationship of low-mass stars and does not require ad hoc changes in magnetic braking or in the structure of cataclysmic variable secondaries. If correct, it will allow broader application of cataclysmic variable observations to problems of basic stellar physics.
Bi-maximal mixing of three neutrinos

Abstract We show that if the solar and atmospheric data are both described by maximal vacuum oscillations at the relevant mass scales then there exists a unique mixing matrix for three neutrino flavors. The solution necessarily conserves CP and automatically implies that there is no disappearance of atmospheric ν e , consistent with indications from the Super-Kamiokande experiment. We also investigate the consequences for three-neutrino mixing if the solar and atmospheric oscillations exhibit mixing that is large but not maximal. For non-maximal mixing ν e ↔ ν τ and ν e ↔ ν μ oscillations are predicted that may be observable in future long-baseline experiments.
F-theory orientifolds, M-theory orientifolds, and twisted strings

Abstract Orientifolds of the type 11B superstring that descend from F-theory and M-theory orbifolds are studied perturbatively. One finds strong evidence that a previously ignored twisted open string is required in these models. An attempt is made to interpret the J-type torsion in F-theory where one finds a realization of Gimon and Johnson's models which does not require these twisted strings. S -duality also provides evidence for these strings.
Preparation of enediyne-crosslinked networks and their reactivity under thermal and mechanical conditions

Abstract The COGEF technique (COnstrained Geometries simulating External Force) was used to investigate the effects of macroscopic forces on cyclic enediynes, which can undergo Bergman Cyclization (BC). Because the forces needed to activate BC were found to be less than the forces needed for chain scission in polymer backbones, the calculations suggest that enediynes are potentially useful mechanophores. Three enediynes studied computationally were synthesized. The thermal BC reactions for these compounds were studied by DSC and found to be consistent with the predicted thermal sensitivity based on known substituent effects. However, upon incorporation of the enediynes into a polymer matrix as crosslinks, no definitive mechanical activation was observed, and conclusions about the stress-sensitivity of enediynes were unable to be drawn. Model studies suggest that insufficient force was applied to the crosslinks for mechanical activation to be observable by DSC.
Synthesis of heterocyclic β-amino acids. A convenient preparation of β-amino-5-pyrimidinepropanoic acid and derivatives.

Abstract The novel (2E)-1,1-dimethylethyl-3-(5-pyrimidinyl)-2-propenoate 3 , obtained by Heck coupling between 5-bromopyrimidine and tert-butyl acrylate undergoes nearly quantitative Michael addition in t-butanol saturated with ammonia to the hitherto unknown β-amino-5-pyrimidinepropanoic ester 4 . The synthetic utility of this reactions sequence is demonstrated by preparation of 4 on a multigram scale. The transformation of the ester to the free amino acid 5 and to the Cbz-N-protected amino acid 7 is described. The tert-butyl ester 4 and the N-protected β-amino acid 7 are useful in peptide and peptidomimic synthesis.
PHENOMENOLOGY OF GOLDSTINO COUPLINGS

A general coupling of the Goldstino to the matter field and the weak gravitational field is constructed based on the standard and nonlinear Volkov–Akulov realization of SUSY. The resulting Lagrangian, which is invariant under SUSY transformations, can give rise to explicit interactions which couple the helicity ±1/2 states of the gravitino with the gravitational field as well as the matter field.
Asymmetric synthesis of α-alkylated α-amino acids: azepane-2-carboxylic acids

Abstract The synthesis of optically active α-alkylated azepane-2-carboxylic acid esters 3 was achieved via Schmidt rearrangement of optically active ethyl 2-oxo-1-alkyl-cyclohexanecarboxylates 1 followed by selective reduction of the amide carbonyl group.
Application of an Ultrasonic Phase Insensitive Receiver to Material Measurements

The theory of a phase insensitive receiver based on acousto-electric effect is presented along with experimental characteristics of a CdS acousto-electric converter (AEC). Since the AEC is nearly phase insensitive, it is ideal for measurements in inhomogeneous materials and/or materials with irregular flatness and parallelism. Through transmission ultrasonic C-scan data of phantom flaws demonstrates a significant improvement in flaw characterization with an AEC over that of a conventional transducer. In addition, measurements with conventional transducers in anisotropically stressed metal samples are shown to lead to grossly inaccurate results due to phase sensitivity. Various other measurements are presented with data contrasting conventional transducers with an AEC in specific NDE applications.
The Impact on Housing Values of Restrictions on Rights of Ownership: The Case of an Occupant's Age

With the exception of anecdotal information, little is known about the specific effects on the value of a house because its ownership is restricted to people older than a certain age. This article provides an empirically-derived assessment of the impact on the selling price of single-family residences when their ownership is age restricted. To determine the effect on the sales price of age-restricted houses, a standard hedonic pricing model is applied to a sample of 371 sales transactions drawn from a suburban area of a large city. The results indicate that an age restriction placed on houses decreases their value by 6%. This finding may be of interest to local land-use regulators, developers who are considering developing age-restricted houses and appraisers who wish to make value adjustments to these homes.
The study of the intramolecular heavy atom effect in 9,10-dichlorophenanthrene and 1,2,3,4-tetrachloronaphthalene using PMDR techniques

Abstract Using PMDR techniques, the top two zero-field triplet levels in 9,10-dichlorophenanthrene and 1,2,3,4-tetrachloronaphthalene are shown to be most favoured by S1 → T1 ISC and T1 → S0 phosphorescence. Spin—orbit vibronic coupling via CCl out-of-plane modes and static distortions of the heavy atom are responsible for such behaviour respectively.
Complex polynomials and circuit lower bounds for modular counting

We study the power of constant-depth circuits containing negation gates, unbounded fan-in AND and OR gates, and a small number of MAJORITY gates. It is easy to show that a depth 2 circuit of sizeO(n) (wheren is the number of inputs) containingO(n) MAJORITY gates can determine whether the sum of the input bits is divisible byk, for any fixedk>1, whereas it is known that this requires exponentialsize circuits if we have no MAJORITY gates. Our main result is that a constant-depth circuit of size $$2^{n^{o(1)} } $$ containingn o(1) MAJORITY gates cannot determine if the sum of the input bits is divisible byk; moreover, such a circuit must give the wrong answer on a constant fraction of the inputs. This result was previously known only fork=2. We prove this by obtaining an approximate representation of the behavior of constant-depth circuits by multivariate complex polynomials.
Optimal Portfolios of External Debt in Developing Countries: The Potential Role of Commodity-Linked Bonds

Much of the spectacular growth in external borrowing by developing countries during the 1970s was in the form of general obligation loans denominated in U.S. dollars at floating interest rates. It is now well understood that this strategy involved substantial risks. An unexpected deterioration in a country's terms of trade can quickly erode its ability to service large debts. In turn, this may induce restricted access to new external credit and a period of forced adjustment in domestic consumption and investment. These risks have become all
Characterization of a freezing/melting transition in a vibrated and sheared granular medium

We describe experiments on monodisperse spherical particles in an annular cell geometry, vibrated from below and sheared from above. This system shows a freezing/melting transition such that under sufficient vibration a crystallized state is observed, which can be melted by sufficient shear. We characterize the hysteretic transition between these two states, and observe features reminiscent of both a jamming transition and critical phenomena.
Using the Galactic Dynamics of M7 Dwarfs to Infer the Evolution of Their Magnetic Activity

We present a spectroscopic study and dynamical analysis of ~2600 M7 dwarfs. We confirm our previous finding that the fraction of magnetically active stars decreases with vertical distance from the Galactic plane. We also show that the mean luminosity of the Hα emission has a small but statistically significant decrease with distance. Using space motions for ~1300 stars and a simple one-dimensional dynamical simulation, we demonstrate that the drop in the activity fraction of M7 dwarfs can be explained by thin disk dynamical heating and a rapid decrease of magnetic activity at a mean stellar age of ~6-7 Gyr.
Inhibition of mast cell mediator release by 5-amino-4-imidazolecarboxamide riboside.

Abstract Stimulated mast cells produce and release adenosine, and the release of mast cell mediators is potentiated by adenosine, yet very little is known regarding mast cell purine metabolism. Because 5-amino-4-imidazolecarboxamide riboside (AICA riboside) has been shown to alter adenosine metabolism and accelerate the repletion of ATP pools in other tissues, its effects on mast cell function were examined. Neither simultaneous addition of A23187 and AICA riboside nor a 1-hr preincubation with AICA riboside altered mast cell β-hexosaminidase release to an appreciable degree. However, mouse bone marrow-derived mast cells cultured for 2 or more days in the presence of 1–100 μM AICA riboside exhibited a markedly attenuated mediator release response to A23187 compared to control cells with or without the additional presence of adenosine. IgE-mediated leukotriene C4 generation from AICA riboside-exposed mast cells was even more profoundly inhibited without affecting cell viability or resting mediator content. An unusual ribonucleotide triphosphate previously identified in folate-depleted cells, 5-aminoimidazole-4-carboxamide-1-β- d -ribofuranosyl 5′-triphosphate (ZTP), has been identified in AICA riboside-treated mast cells as well. Although the mechanism of this global inhibition of mast cell mediator release by chronic AICA riboside treatment is not clear, alterations in mast cell purine metabolism may prove to be important in the treatment of allergic diseases.
Performance of polymer electrolyte cells at +25 to +100°C

Abstract Solid state rechargeable polymer electrolyte batteries utilizing lithium anodes and V6O13 composite cathodes were investigated at 100°C. The polymer electrolyte was a complex formed between polyethylene oxide (PEO) and LiCF3SO3. Over a hundred cycles were obtained at the C/5 rate (45% depth of discharge) with greater than 75% of the initial capacity of V6O13 being maintained at cycle number one hundred. Cells made with propylene carbonate (PC) doped polymer electrolyte also showed good performance at room temperature.
A Frobenius theorem for Cartan geometries, with applications

The classical result on local orbits in geometric manifolds is Singer’s homogeneity theorem for Riemannian manifolds [1]: given a Riemannian manifold M , there exists k, depending on dimM , such that if every x, y ∈ M are related by an infinitesimal isometry of order k, thenM is locally homogeneous. An open subset U ⊆ M of a geometric manifold is locally homogeneous if for every x, x ∈ U , there is a local automorphism f in U with f(x) = x. Such a local automorphism is a diffeomorphism from a neighborhood V of x in U to a neighborhood of x in U , with f an isomorphism between the geometric structures restricted to V and f(V ).
Cord transfusions in newborn infants

Summary 1. A total of 189 cord transfusions were done during 1944 with 174 living babies. 2. Ninety-nine premature babies received cord transfusions of mother's blood, with fourteen deaths. Six of these weighed less than 3 pounds; nine were twenty-eight weeks' gestation. 3. Twenty-one babies were transfused following long labors or difficultdeliveries, with no deaths. 4. The blood was grouped and the Rh factor determined in 1,910 women.Of these, 294 were found to be Rh-negative and 137 were delivered in 1944 with the loss of four infants, two in the group of seventy-eight receiving cord transfusions, two in the group of fifty-nine not receiving such transfusions. 5. The babies of seventy-eight Rh-negative mothers received cord transfusionsof mother's blood. There were two deaths, both premature infants. Three cases of erythroblastosis were diagnosed in the group, with recovery. 6. Of fifty-nine babies of Rh-negative mothers not given cord transfusions,there were five cases of erythroblastosis, with two deaths. One of the babies was very jaundiced, with no normoblasts; the other had 158 normoblasts to 100 white cells. 7. A study was made of 601 cord smears; 288 contained no normoblasts,thirty-four more than 15. Among these thirty-four infants there were five deaths and one stillbirth. Five of the six mothers were Rh positive; one Rh negative. Of the eleven infants of Rh-negative mothers in the group of thirty-four, nine received a cord transfusion, with one death, a premature infant. 8. A case is reported in which 90 c.c. of blood from an Rh-negative mother of high titer, 1:80, was given to her baby for marked jaundice with definite improvement in the baby's condition.
Yielding and microstructure in a 2D jammed material under shear deformation

The question of how a disordered material's microstructure translates into macroscopic mechanical response is central to understanding and designing materials like pastes, foams and metallic glasses. Here, we examine a 2D soft jammed material under cyclic shear, imaging the structure of ∼5 × 104 particles. Below a certain strain amplitude, the structure becomes conserved at long times, while above, it continually rearranges. We identify the boundary between these regimes as a yield strain, defined without rheological measurement. Its value is consistent with a simultaneous but independent measurement of yielding by stress-controlled bulk rheometry. While there are virtually no irreversible rearrangements in the steady state below yielding, we find a largely stable population of plastic rearrangements that are reversed with each cycle. These results point to a microscopic view of mechanical properties under cyclic deformation.
The Quantum Collective Field Method and Its Application to the Planar Limit

Abstract We formulate a general method of collective fields in quantum theory, which represents a direct generalization of the Bohm-Pines treatment of plasma oscillations. The present method provides a complete procedure for reformulating a given quantum system in terms of a most general (overcomplete) set of commuting operators. We point out and exemplify how this formalism offers a new powerful method for studying the large- N limit. For illustration we discuss the collective motions of N identical harmonic oscillators. As a much more important application, we show how, based on the present formalism, one solves the planar limit of a non-trivial SU( N ) symmetric quantum theory.
On polymorphic types of untyped terms

Abstract Let S be a finite set of β normal closed terms and M and N a pair of β normal, η distinct, closed terms. Then there exist polymorphic types a , b such that every member of S can be typed as a , and M and N have η expansions which can be typed as b ; where, in the resulting typings, the members of S can be simultaneously consistently identified, and the η expansions of M and N are βη inconsistent (no model with more than one element of any type). A similar result holds in the presence of surjective pairing.
Glucose Modulation of Glucokinase Activation by Small Molecules

Small molecule activators of glucokinase (GK) were used in kinetic and equilibrium binding studies to probe the biochemical basis for their allosteric effects. These small molecules decreased the glucose K0.5 (∼1 mM vs ∼8 mM) and the glucose cooperativity (Hill coefficient of 1.2 vs 1.7) and lowered the kcat to various degrees (62–95% of the control activity). These activators relieved GK’s inhibition from glucokinase regulatory protein (GKRP) in a glucose-dependent manner and activated GK to the same extent as control reactions in the absence of GKRP. In equilibrium binding studies, the intrinsic glucose affinity to the activator-bound enzyme was determined and demonstrated a 700-fold increase relative to the apoenzyme. This is consistent with a reduction in apparent glucose KD and the steady-state parameter K0.5 as a result of enzyme equilibrium shifting to the activator-bound form. The binding of small molecules to GK was dependent on glucose, consistent with the structural evidence for an allosteric b...
Stiffness of smart composites with shape memory alloy fibers in the presence of matrix cracks

The paper presents a methodology for evaluating the effective stiffness of unidirectional composite materials with shape memory alloy (SMA) fibers in the presence of matrix cracks. The solution is obtained for the case where SMA fibers in the intact composite are in the austenitic phase. However, elevated stresses in the sections of SMA fibers adjacent to the crack planes cause the martensitic transformation affecting the stiffness of the material. The solution has to account for thermal residual stresses in SMA and "ordinary" fibers and in the matrix. The order of magnitude of these stresses is calculated in the paper for two representative composite systems. As follows from the numerical examples, thermal residual stresses in the SMA fibers increase proportionally to their volume fraction but remain relatively small. However, thermal stresses in the matrix may reach rather high values reducing the strength of the matrix by a significant factor.
Time-Resolved Reflectivity Studies of Carrier Dynamics as a Function of Al Content in AlGaN Alloys

We have used intensity dependent pump-probe reflectivity measurements to investigate the carrier dynamics in AlGaN alloys with Al content ranging from ∼0.15 to 0.4. For the Al 0.15 Ga 0.85 N sample the intensity dependence of the ΔR decay suggests that at high intensity the shallow traps are saturated and ultrafast nonradiative recombination dominates the carrier dynamics. For the Al 0.25 Ga 0.75 N and Al 0.4 Ga 0.6 N samples AR decays faster with decreasing intensity and changes sign. Moreover, the decays are faster for a given intensity in the higher Al content sample. This behavior suggests that in these cases the dynamics are governed by trapping at localized states that become deeper and more numerous as the Al content increases. Within this context the sign change in AR may reflect the onset of photoinduced absorption associated with the excitation of carriers from the localized states to the bands.