cssi/SciSciGPT-SciSciNet huggingface dataset:
Tutte Polynomials and a Stronger Version of the Akiyama-Harary Problem

Can a non self-complementary graph have the same chromatic polynomial as its complement? The answer to this question of Akiyama and Harrary is positive and was given by J. Xu and Z. Liu. They conjectured that every such graph has the same degree sequence as its complement. In this paper we show that there are infinitely many graphs for which this conjecture does not hold. We then solve a more general variant of the Akiyama-Harary problem by showing that there exists infinitely many non self-complementary graphs having the same Tutte polynomial as their complements.
Fourier-Based Fast Multipole Method for the Helmholtz Equation

The fast multipole method (FMM) has had great success in reducing the computational complexity of solving the boundary integral form of the Helmholtz equation. We present a formulation of the Helmholtz FMM that uses Fourier basis functions rather than spherical harmonics. By modifying the transfer function in the precomputation stage of the FMM, time-critical stages of the algorithm are accelerated by causing the interpolation operators to become straightforward applications of fast Fourier transforms, retaining the diagonality of the transfer function, and providing a simplified error analysis. Using Fourier analysis, constructive algorithms are derived to a priori determine an integration quadrature for a given error tolerance. Sharp error bounds are derived and verified numerically. Various optimizations are considered to reduce the number of quadrature points and reduce the cost of computing the transfer function.
THE ELECTROMAGNETIC MODEL OF SHORT GRBs, THE NATURE OF PROMPT TAILS, SUPERNOVA-LESS LONG GRBs, AND HIGHLY EFFICIENT EPISODIC ACCRETION

Many short gamma-ray bursts (GRBs) show prompt tails lasting up to hundreds of seconds that can be energetically dominant over the initial sub-second spike. In this paper we develop an electromagnetic model of short GRBs that explains the two stages of the energy release, the prompt spike and the prompt tail. The key ingredient of the model is the recent discovery that an isolated black hole can keep its open magnetic flux for times much longer than the collapse time and thus can spin down electromagnetically, driving the relativistic wind. First, the merger is preceded by an electromagnetic precursor wind with total power , reaching 3 × 1044 erg s–1 for typical neutron star masses of 1.4 M ☉ and magnetic fields B ~ 1012 G. If a fraction of this power is converted into pulsar-like coherent radio emission, this may produce an observable radio burst of a few milliseconds (like the Lorimer burst). At the active stage of the merger, two neutron stars produce a black hole surrounded by an accretion torus in which the magnetic field is amplified to ~1015 G. This magnetic field extracts the rotational energy of the black hole and drives an axially collimated electromagnetic wind that may carry of the order of 1050 erg, limited by the accretion time of the torus, a few hundred milliseconds. For observers nearly aligned with the orbital normal this is seen as a classical short GRB. After the accretion of the torus, the isolated black hole keeps the open magnetic flux and drives the equatorially (not axially) collimated outflow, which is seen by an observer at intermediate polar angles as a prompt tail. The tail carries more energy than the prompt spike, but its emission is de-boosted for observers along the orbital normal. Observers in the equatorial plane miss the prompt spike and interpret the prompt tail as an energetic long GRB (the supernova-less long burst GRB060505 and GRB060614 may belong to this category). We also demonstrate that episodic accretion onto the black hole of magnetized clouds that carry non-zero magnetic flux can be highly efficient in extracting the spin energy of the black hole, producing the electromagnetic outflows with power exceeding the average accretion power and total energy exceeding the rest mass energy of the accreted mass. We identify the late time flares with such accretion events.
The Afterglow and the Host Galaxy of the Dark Burst GRB 970828

GRB 970828 was the first well-localized γ-ray burst (GRB) X-ray afterglow for which no optical afterglow was found despite a prompt, deep search down to Rlim ~ 24.5 mag. We report the discovery of a short-lived radio flare within the X-ray localization error circle of this burst. Such radio flares are seen in about 25% of GRB afterglows, and their origin is not well understood. The precise radio position enabled us to identify the likely host galaxy of this burst and to measure its redshift, z = 0.9578. The host appears to be an interacting/merging system. Under the assumption that the X-ray afterglow is mainly due to synchrotron mechanism, we infer the optical afterglow flux. The observed upper limits to the optical flux are easily explained by invoking an intervening dusty cloud within the host galaxy. These observations support the idea that GRBs with no detectable optical afterglows, or "dark GRBs," can be due to dust extinction within the host galaxies. The census of dark GRBs can then be used to constrain the fraction of the obscured star formation in the universe. We argue that the existing data already indicate that the obscured star formation rate is no more than one-half of that seen at UV and optical wavelengths.
Rate-Distortion Theory for Secrecy Systems

Secrecy in communication systems is measured herein by the distortion that an adversary incurs. The transmitter and receiver share secret key, which they use to encrypt communication and ensure distortion at an adversary. A model is considered in which an adversary not only intercepts the communication from the transmitter to the receiver, but also potentially has side information. In particular, the adversary may have causal or noncausal access to a signal that is correlated with the source sequence or the receiver's reconstruction sequence. The main contribution is the characterization of the optimal tradeoff among communication rate, secret key rate, distortion at the adversary, and distortion at the legitimate receiver. It is demonstrated that causal side information at the adversary plays a pivotal role in this tradeoff. It is also shown that measures of secrecy based on normalized equivocation are a special case of the framework.
Public domain rank: identifying notable individuals with the wisdom of the crowd

Identifying literary, scientific, and technical works of enduring interest is challenging. Few are able to name significant works across more than a handful of domains or languages. This paper introduces an automatic method for identifying authors of notable works throughout history. Notability is defined using the record of which works volunteers have made available in public domain digital editions. A significant benefit of this bottom-up approach is that it also provides a novel and reproducible index of notability for all individuals with Wikipedia pages. This method promises to supplement the work of cultural organizations and institutions seeking to publicize the availability of notable works and prioritize works for preservation and digitization.
The Starburst in the Abell 1835 Cluster Central Galaxy: A Case Study of Galaxy Formation Regulated by an Outburst from a Supermassive Black Hole

We present an analysis of the starburst in the Abell 1835 cluster's cD galaxy. The dense gas surrounding the galaxy is radiating X-rays at a rate of ~1045 ergs s-1, which is consistent with a cooling rate of ~1000-2000 M☉ yr-1. However, Chandra and XMM-Newton observations found less than 200 M☉ yr-1 of cooling below ~2 keV, a level that is consistent with the cD's current star formation rate of 100-180 M☉ yr-1. One or more heating agents (feedback) must then be replenishing the remaining radiative losses. Supernova explosions and thermal conduction are unable to do so. However, the active galactic nucleus (AGN) is pumping 1.4 × 1045 ergs s-1into the hot gas, which is enough power to offset most of the radiative cooling losses. The AGN jet power exceeds the radio synchrotron power by ~4000 times, making this one of the most radiatively inefficient radio sources known. The jet power implies that the supermassive black hole has accreted at a mean rate of ~0.3 M☉ yr-1 over the last 40 Myr or so, which is a small fraction of the Eddington accretion rate for a ~109 M☉ black hole. The ratio of black hole growth rate by accretion to bulge growth by star formation is consistent with the slope of the (Magorrian) relationship between bulge and central black hole mass in nearby quiescent galaxies. The starburst follows the Schmidt-Kennicutt parameterizations, indicating that the local environment is not substantially altering the IMF and other conditions leading to the onset of star formation. The consistency between net cooling, heating (feedback), and the cooling sink (star formation) in this system resolves the primary objection to traditional cooling flow models.
Chiral Magnesium BINOL Phosphate-Catalyzed Phosphination of Imines: Access to Enantioenriched α-Amino Phosphine Oxides

A new method to synthesize chiral α-amino phosphine oxides is reported. The reaction combines N-substituted imines and diphenylphosphine oxide and is catalyzed by a chiral magnesium phosphate salt. A wide variety of aliphatic and aromatic aldimines substituted by electron-neutral benzhydryl or dibenzocycloheptene groups were excellent substrates for the addition reaction. The dibenzocycloheptene protected imines afforded improved enantioselectivity in the resulting products. Substituted diphenylphosphine oxide nucleophiles also showed good reactivity.
Collective variables of fermions and bosonization

Abstract We first present a general method for extracting collective variables out of non-relativistic fermions by extending the gauge theory of collective coordinates to fermionic systems. We then apply the method to a system of non-interacting flavored fermions confined in a one-dimensional flavor-independent potential. In the limit of a large number of particles we obtain a Lagrangian with the Wess-Zumino-Witten term, which is the well-known Lagrangian describing the non-Abelian bosonization of chiral fermions on a circle. The result is universal and does not depend on the details of the confining potential.
Opioid growth factor inhibits intimal hyperplasia in balloon-injured rat carotid artery.

Abstract Objective: The endogenous opioid [Met 5 ]-enkephalin (opioid growth factor [OGF]) is a tonically active, receptor-mediated inhibitory growth peptide in developing and adult vasculature. This study was designed to determine the role of OGF in neointimal hyperplasia. Methods: The carotid artery in adult male Sprague-Dawley rats was denuded with balloon catheterization. OGF (10 mg/kg), the opioid antagonist naltrexone (NTX; 30 mg/kg), or saline solution (0.2 mL) was injected intraperitoneally daily for 28 days into the rats, and restenosis of the carotid artery was examined with morphometric analysis using Optimas software. Proliferation of the neointima and media was measured by radioactive thymidine incorporation over 3 hours. The presence of OGF and its receptor, OGFr, were examined with immunofluorescence microscopy. Results: OGF depressed DNA synthesis in the intima and media from 16% to 78% of control levels in the first 2 weeks after deendothelialization, whereas NTX exposure elevated DNA synthesis by 21% to 89%. OGF action was receptor-mediated. In the month after injury the thickness of the intima in OGF-treated rats was decreased by 18% to 31% from control values, whereas intimal thickness was increased in the NTX group by 10% to 31%. Luminal area was almost 25% greater than control values in the OGF group, but was reduced 17% by NTX. OGF and the OGF receptor were detected in the carotid artery with immunohistochemistry. Conclusions: These results demonstrate for the first time that a native opioid system modulates repair of vascular injury. OGF is a constitutively active peptide that has a receptor-mediated action in the negative regulation of neointimal growth, a major cause of restenosis. (J Vasc Surg 2003;37:636-43.)
V344 LYRAE: A TOUCHSTONE SU UMa CATACLYSMIC VARIABLE IN THE KEPLER FIELD

We report on the analysis of the Kepler short-cadence (SC) light curve of V344 Lyr obtained during 2009 June 20 through 2010 Mar 19 (Q2-Q4). The system is an SU UMa star showing dwarf nova outbursts and superoutbursts, and promises to be a touchstone for CV studies for the foreseeable future. The system displays both positive and negative super humps with periods of 2.20 and 2.06-hr, respectively, and we identify an orbital period of 2.11-hr. The positive super humps have a maximum amplitude of approximately 0.025-mag, the negative super humps a maximum amplitude of approximately 0.8 mag, and the orbital period at quiescence has an amplitude of approximately 0.025 mag. The quality of the Kepler data is such that we can test vigorously the models for accretion disk dynamics that have been emerging in the past several years. The SC data for V344 Lyr are consistent with the model that two physical sources yield positive superhumps: early in the superoutburst. the superhump signal is generated by viscous dissipation within the periodically flexing disk. but late in the superoutburst, the signal is generated as the accretion stream bright spot sweeps around the rim of the non-axisymmetric disk. The disk super humps are roughly anti-phased with the stream/late superhumps. The V344 Lyr data also reveal negative super humps arising from accretion onto a tilted disk precessing in the retrograde direction, and suggest that negative superhumps may appear during the decline of DN outbursts. The period of negative superhumps has a positive P(raised dot) in between outbursts.
Normative engineering risk management systems

This paper describes a normative system design that incorporates diagnosis, dynamic evolution, decision making, and information gathering. A single influence diagram demonstrates the design's coherence, yet each activity is more effectively modeled and evaluated separately. Application to offshore oil platforms illustrates the design. For this application, the normative system is embedded in a real-time expert system.
Detailed product and kinetic analysis for the low-pressure selective oxidation of isobutane over phosphomolybdic acid

The selective oxidation of isobutane over phosphomolybdic acid has been analyzed using a low-pressure steady-state technique. Observed products are methacrolein, 3-methyl-2-oxetanone (a lactone), acetic acid, carbon dioxide and water. These products form in two distinct fashions designated Categories 1 and 2. Category 1 is exclusively observed with methacrolein and is consistent with a Bulk- type (II) process. The lactone and acetic acid are Category 2 products and these form by the Bulk-type (I) mechanism. A kinetic analysis of the distributions shows that the activation energy for Category 1 production (methacrolein) increases with experiment number (varying from 56.9 ± 1.5 to 149 ± 4 kJ mol -1 ) and indicates a temperature-induced structural degradation of phosphomolybdic acid. The Category 2 products are not similarly affected and this suggests that the structural degradation is restricted to the surface of phosphomolybdic acid.
Experimental Investigation of MR Squeeze Mounts

Based on results obtained from testing MR fluid in a squeeze mode rheometer, a novel compression-adjustable element has been fabricated and tested, which utilizes MR fluid in the squeeze mode. While shear and valve modes have been used exclusively for MR fluid damping applications, recent modeling and testing with MR fluid has revealed that much larger adjustment ranges are achievable in the squeeze mode. Utilizing the squeeze mode, an MR squeeze mount was developed and tested. Test results show that the device was capable of varying the compression force from less than 8 lb 35.6 N to greater than 800 lb 3560 N, when the pole plates were 0.050 in. 1.3 mm apart. Test results showed that the mount tends to achieve higher forces after each repeat of test. This behavior, called ‘clumping’, was studied and solutions to minimize this effect are discussed.
Boc Groups as Protectors and Directors for Ir-Catalyzed C–H Borylation of Heterocycles

Ir-catalyzed C−H borylation is found to be compatible with Boc protecting groups. Thus, pyrroles, indoles, and azaindoles can be selectively functionalized at C−H positions β to N. The Boc group can be removed on thermolysis or left intact during subsequent transformations.
Heavy particle content in QCD jets

We calculate the multiplicity of heavy quark pairs in gluon jets in lowest order QCD, along with the non-perturbative correction related to the gluon condensate 〈(α/π)F2〉. The value of the non-perturbative correction is where M is the mass of the heavy quark, N is the number of colors, and CF and CA are the values of the Casimir operators in the fundamental and adjoint representation respectively. α(M) is the running coupling constant at the scale of the heavy quark, and 〈F2〉 is the gluon condensate, usually determined to be 〈α/πF2〉 ∼ 0.012 GeV4. The non-perturbative correction is extremely small.
Hessenberg pairs of linear transformations

Abstract Let K denote a field and V denote a nonzero finite-dimensional vector space over K . We consider an ordered pair of linear transformations A : V → V and A ∗ : V → V that satisfy (i)–(iii) below. 1. [(i)]Each of A , A ∗ is diagonalizable on V . 2. [(ii)]There exists an ordering { V i } i = 0 d of the eigenspaces of A such that A ∗ V i ⊆ V 0 + V 1 + ⋯ + V i + 1 ( 0 ⩽ i ⩽ d ) , where V - 1 = 0 , V d + 1 = 0 . 3. [(iii)]There exists an ordering { V i ∗ } i = 0 δ of the eigenspaces of A ∗ such that AV i ∗ ⊆ V 0 ∗ + V 1 ∗ + ⋯ + V i + 1 ∗ ( 0 ⩽ i ⩽ δ ) , where V - 1 ∗ = 0 , V δ + 1 ∗ = 0 . We call such a pair a Hessenberg pair on V . In this paper we obtain some characterizations of Hessenberg pairs. We also explain how Hessenberg pairs are related to tridiagonal pairs.
Pyruvate as a pivot point for oncogene-induced senescence.

Regulation of pyruvate fate is an important determinant of anabolic versus catabolic metabolism. A new report in the journal Nature by Kaplon et al. suggests that driving pyruvate oxidation can thwart tumor growth in BRAF-driven melanoma by inducing oncogene-induced senescence, a finding that might be exploited therapeutically.
Dust settling in magnetorotationally-driven turbulent discs - II. The pervasiveness of the streaming instability and its consequences

We present a series of simulations of turbulent stratified protostellar discs with the goal of characterizing the settling of dust throughout a minimum-mass solar nebula. We compare the evolution of both compact spherical grains, as well as highly fractal grains. Our simulations use a shearing-box formulation to study the evolution of dust grains locally within the disc, and collectively our simulations span the entire extent of a typical accretion disc. The dust is stirred by gas that undergoes magnetorotational instability-driven turbulence. The turbulence tends to lift the dust above the disc's mid-plane, while gravity tends to draw it back to the mid-plane. This establishes a steady state scaleheight for the dust that is different for dust of different sizes. This sedimentation of dust is an important first step in planet formation and we predict that the Atacama Large Millimeter Array (ALMA) should be able to observationally verify its existence. When significant sedimentation occurs, the dust will participate in a streaming instability that significantly enhances the dust density. We show that the streaming instability is pervasive at many of the outer radial stations in a disc. We characterize the scaleheights of dust whose size ranges from a few micrometres all the way up to a few centimetres. We find that for spherical grains, a power-law relationship develops for the scaleheight with grain size, with a slope that is slightly steeper than −1/2. The sedimentation is strongest in the outer disc and increases for large grains. The results presented here show that direct measurements of grain settling can be made by ALMA and we present favourable conditions for observability. The streaming instability should also be directly observable and we provide conditions for directly observing it. We calculate collision rates and growth rates for the dust grains in our simulations of various sizes colliding with other grains, and find that these rates are significantly enhanced through the density enhancement arising from the streaming instability.
The pitting corrosion of sputtered Fe base alloy films

Abstract Predominantly single phase Fe base alloy films were prepared by a DC sputtering method. The compositions of the alloy films, as determined by Auger electron spectroscopy (AES) were Fe-7 at% Cr and Fe-18 at% Cr, Fe-11 at% W and Fe-19 at% W, Fe-9, −13 and −27 at% Ta. The pitting potential of the sputtered alloys determined in chloride solutions was found to be strongly dependent on the nature and the concentration of the alloying element. The pitting potential of sputtered Fe-18 at% Cr and Fe-27 at% Ta alloy films were approximately 0.9 V higher than that of bulk Fe and 0.6 V higher than that of Fe-19 at% W alloy film. A very good correlation was found between the pitting potential of Fe alloy films and the solubility of an alloying element oxide in acidic solutions with a pH corresponding to that within the stable pits of pure Fe (pH = 2). The pitting potential of the Fe alloy was found to increase with a decrease in the solubility of the alloying element oxide in acidic solutions. The pitting potentials of the sputtered Fe-7 at% Cr and Fe-18 at% Cr alloy films were were significantly higher than those of the bulk materials with the same composition. The higher pitting potentials of these alloy films are tentatively attributed to the presence of very fine particles of the oxide phase that are homogeneously distributed in the sputtered alloys.
Weak Extinction Limits of Turbulent Heterogeneous Fuel/Air Mixtures

Experimental and theoretical studies are made of the factors governing the weak extinction limits of stabilized flames supplied with flowing mixtures of liquid fuel drops and air. The test program includes wide variations in inlet air pressure, velocity and turbulence level, and also covers wide ranges of fuel volatility and mean drop size. The influence of flameholder size and blockage is also examined. An equation is derived for predicting weak extinction limits which shows good agreement with the corresponding experimental values. Paper No. 79-GT-157.
FIRST INTRAMOLECULAR BENZYNE DIELS-ALDER REACTION WITH AN ACYCLIC DIENE. UNUSUAL EFFECT OF DIENE GEOMETRY ON THE COURSE OF THE REACTION

Abstract The first intramolecular benzyne Diets-Alder reaction with an acyclic diene is reported. The course of the reaction is dependent on the diene geometry. Trans dienes afford [4+2] cycloadducts; cis dienes apparently give [2+2 ] cycloadducts followed by further rearrangement, a mechanistic course which is supported by deuterium labeling experiments.
SIMULTANEOUS PLACEMENT OF ACTUATORS AND SENSORS

A placement of actuator and sensors for flexible structures is studied using the H 2 , H∞, and Hankel modal norms. The norm of a flexible structure with multiple actuators and sensors is a root-mean-square sum of norms of structures equipped with single sensor and single actuator. This property allows for the evaluation of the importance of a combination of sensors and actuator, in terms of their participation in the overall structural dynamics. This simple and powerful tool is applicable for structures only, since in a general case, a system norm cannot be decomposed into a combination of single-input-single-output norms, and consequently complex searching techniques need to be used. The algorithm consists of the determination either H 2 , or H∞, or Hankel norms for the rth mode, jth actuator, and kth sensor. Using the norms, the sensor and actuator placement matrices are generated for each considered mode. The matrices are used to evaluate each sensor and actuator combination, and to determine the simultaneous actuator and sensor locations such that the norm of the each mode is maximized. The approach is illustrated with the truss example that includes the physical interpretation of the selection.
On the Mechanism of Genetic Recombination between DNA Molecules

A two-factor cross was performed between bacteriophages labeled with heavy isotopes. Recombinants were found with chromosomes formed entirely or almost entirely of parental DNA. This and other features of the distribution of parental DNA among recombinant phages and among their descendants show that genetic recombination occurs by breakage and joining of double-stranded DNA molecules. Also, there is some indication that a small amount of DNA is removed and resynthesized in the formation of recombinant molecules.
Exitus: Agent-Based Evacuation Simulation for Individuals with Disabilities in a Densely Populated Sports Arena

Emergency evacuation of critical infrastructure assets such as sports arenas is an important consideration given the continuing threat of terrorist attacks which inordinately affect them. In this paper, the authors present an agent-based evacuation model which may be used to support private sector organizations with capabilities-based planning efforts surrounding likely terrorist attack scenarios. The model is distinguished by its explicit consideration of individuals with disabilities in respect to the characteristics influencing their ability to negotiate surroundings. The results of an experiment simulating the truck bombing of an intermountain west sports arena reveal special areas of concern for arena managers and identify those who are most at risk or individuals with lower stamina. Ultimately, the model can be used to inform policymakers of more effective, evidence-based evacuation planning methods based on a better understanding of the behavior of heterogeneous populations during emergency situations.
Coordination chemistry of halocarbons

Revue synthetique de travaux concernant la reactivite de complexes de metaux divers avec des derives halogenes. Synthese bibliographique jusqu'a mars 1989
DISTANCE, GROWTH FACTOR, AND DARK ENERGY CONSTRAINTS FROM PHOTOMETRIC BARYON ACOUSTIC OSCILLATION AND WEAK LENSING MEASUREMENTS

Baryon acoustic oscillations (BAOs) and weak lensing (WL) are complementary probes of cosmology. We explore the distance and growth factor measurements from photometric BAO and WL techniques, and investigate the roles of the distance and growth factor in constraining dark energy. We find for WL that the growth factor has a great impact on dark energy constraints, but is much less powerful than the distance. Dark energy constraints from WL are concentrated in considerably fewer distance eigenmodes than those from BAO, with the largest contributions from modes that are sensitive to the absolute distance. Both techniques have some well-determined distance eigenmodes that are not very sensitive to the dark energy equation-of-state parameters w0 and wa, suggesting that they can accommodate additional parameters for dark energy and for the control of systematic uncertainties. A joint analysis of BAO and WL is far more powerful than either technique alone, and the resulting constraints on the distance and growth factor will be useful for distinguishing dark energy and modified gravity models. The Large Synoptic Survey Telescope (LSST) will yield both WL and angular BAO over a sample of several billion galaxies. Joint LSST BAO and WL can yield 0.5% level precision on ten comoving distances evenly spaced in log(1 + z) between redshift 0.3 and 3 with cosmic microwave background priors from Planck. In addition, since the angular diameter distance, which directly affects the observables, is linked to the comoving distance solely by the curvature radius in the Friedmann-Robertson-Walker metric solution, the LSST can achieve a pure metric constraint of 0.017 on the mean curvature parameter Ω k of the universe simultaneously with the constraints on the comoving distances.
Spectral Lines from Rotating Neutron Stars

The line profiles from rotating neutron stars are affected by a number of relativistic processes such as Doppler boosts, strong self-lensing, frame dragging, and the differential gravitational redshift arising from the stellar oblateness. In this Letter, we calculate line profiles, taking into account the first two effects; this approach is accurate for rotation rates less than the breakup frequency. We show that the line profiles are not only broadened and weakened but are also significantly asymmetric, and allow for an independent measurement of both the mass and the radius of the neutron star. Furthermore, we investigate the case when a fraction of the neutron star surface contributes to the emission and find that the line profiles are typically doubly peaked. We discuss the implications of our results for searches for line features in the spectra of isolated neutron stars and X-ray bursters. We finally assess the systematic uncertainties introduced by the line asymmetry in inferring the compactness of neutron stars from the detection of redshifted lines.
Immunologic cytofluorometric studies in adolescents with anorexia nervosa.

Objective : To assess lymphocyte stimulation and lymphocyte phenotype evaluation in adolescent patients with anorexia nervosa (AN). Method : In vitro lymphocyte stimulation and flow cytometric phenotype studies were done on 26 hospitalized patients with AN receiving nutritional rehabilitation. The laboratory assessment consisted of lymphocyte subset analysis and in vitro lymphoproliferative responses to mitogens and antigens. Results : Flow cytometric phenotype analysis showed that only a minority of the patients had abnormal phenotype and immune responses, moreover their immune systems were not significantly impaired. Discussion : The cytofluorometric study of immune function does not show significant alterations in adolescents hospitalized for anorexia nervosa.
On the radius of injectivity of null hypersurfaces

We investigate the regularity of past (future) boundaries of points in regular, Einstein vacuum spacetimes. We provide conditions, expressed in terms of a space-like foliation and which imply, in particular, uniform bounds for the curvature tensor, sufficient to ensure the local nondegeneracy of these boundaries. More precisely we provide a uniform lower bound on the radius of injectivity of the null boundaries of the causal past (future) sets . Such lower bounds are essential in understanding the causal structure and the related propagation properties of solutions to the Einstein equations. They are particularly important in construction of an effective Kirchoff-Sobolev type parametrix for solutions of wave equations on . Such parametrices are used by the authors in a forthcoming paper to prove a large data break-down criterion for solutions of the Einstein vacuum equations
Trade Liberalization and Rural Poverty

work. Trade affects aggregate income and relative prices; it alters investment and savings decisions and thus has intertemporal effects. It may also alter tax revenues and public spending; and its effects are conditioned by transport costs and location-specific phenomena. This makes simple measurement of the effects of trade very difficult and the attribution of causality almost impossible, a problem that has long plagued the literature on trade and growth (see Baldwin for a survey). Attempts to measure the effects of trade on poverty in developing countries face additional challenges in that most of the poor are found in rural areas, in farming, and frequently outside of the formal economy, with the consequence that their activities and incomes can be measured only very approximately. The poor also reveal a frustrating (to data gatherers, at least) tendency to move around in pursuit of job opportunities. Rigorous answers to important and controversial empirical questions, such as whether trade liberalization reduces poverty, have proved elusive.
Ring-Closing Metathesis in Methanol and Water

The ring-closing metathesis (RCM) of acyclic dienes in both methanol and water has been achieved through the use of water-soluble ruthenium alkylidenes. These alkylidenes react readily with acyclic olefins in protic solvents, but they do not cyclize α,ω-dienes because of the instability of the resulting methylidene. Successful cyclization has been achieved through simple substrate modificationincorporation of an olefin substituent allows cyclization to proceed in good yield. A methyl-substituted substrate was cyclized in 60% conversion in methanol, and the incorporation of a phenyl substituent resulted in nearly quantitative cyclization. Phenyl-substituted substrates are best suited for the reaction, as a more stable, active catalyst is regenerated upon each catalyst turnover. Using this methodology, 90% conversion of a water-soluble substrate to a substituted cyclopentene has been achieved in aqueous solution. This methodology has also been successfully applied to increase RCM yields in organic solvents.
Local Well-Posedness of Periodic Fifth-Order KdV-Type Equations

In this paper, the local well-posedness of periodic fifth-order dispersive equations with nonlinear term P 1(u)∂ x u+P 2(u)∂ x u∂ x u is established. Here P 1(u) and P 2(u) are polynomials of u. We also get some new Strichartz estimates.
Policy Change and Venue Choices: Field Burning in Idaho and Washington

Grass seed farmers have burned their fields in Idaho and Washington State for decades. Field burning, however, creates small particulate matter air pollution, thus engendering a growing public backlash by the 1990s that manifested itself in new clean air advocacy groups. The new groups’ push for policy change eventually met with significant success in both cases. How did each set of advocates approach the challenge of policy change? More specifically, what kinds of policy venues did each group choose and why? This research uses the cases to explore and explain each clean air group's choices vis-a-vis hypotheses of venue choice. Three hypotheses are tested—Schattschneider's (1960) “expanded scope of conflict” thesis, ACF's (Sabatier and Jenkins-Smith 1999) contention that groups strategically apply their resources in order to increase the likelihood of achieving their primary goal(s), and Pralle's (2003, 2010) thesis that internal group constraints deter groups from moving into new venues.
HIGHLY VARIABLE EXTINCTION AND ACCRETION IN THE JET-DRIVING CLASS I-TYPE YOUNG STAR PTF 10nvg (V2492 Cyg, IRAS 20496+4354)

We report extensive new photometry and spectroscopy of the highly variable young stellar object PTF 10nvg (also known as IRAS 20496+4354 and V2492 Cyg), including optical and near-infrared time-series data as well as mid-infrared and millimeter data. Following the previously reported 2010 rise to R_(PTF)≾13^m.5 and subsequent fade, during 2011 and 2012 the source underwent additional episodes of brightening, followed by several magnitude dimming events including prolonged faint states at R_(PTF)≳20^m. The observed high-amplitude variations are largely consistent with extinction changes (ΔA_V up to 30 mag) having a ~220 day quasi-periodic signal. However, photometry measured when the source was near maximum brightness in mid-2010 as well as in late-2012 does not phase well to this period. Spectral evolution includes not only changes in the spectral slope but also correlated variation in the prominence of TiO/VO/CO bands and atomic line emission, as well as anti-correlated variation in forbidden line emission which, along with H_2, dominates optical and infrared spectra at faint epochs. Notably, night-to-night variations in several forbidden doublet strengths and ratios are observed. High-dispersion spectra were obtained in a variety of photometric states and reveal time-variable line profiles. Neutral and singly ionized atomic species are likely formed in an accretion flow and/or impact while the origin of zero-velocity atomic Li I λ6707 in emission is unknown. Forbidden lines, including several rare species, exhibit blueshifted emission profiles and likely arise from an outflow/jet. Several of these lines are also seen spatially offset from the continuum source position, presumably in a shocked region of an extended jet. Blueshifted absorption components of the Na I D doublet, K I λλ7665, 7669 doublet, and the O I 7774 triplet, as well as blueshifted absorption components seen against the broad Hα and Ca II triplet emission lines, similarly are formed in the outflow. CARMA maps resolve on larger scales a spatially extended outflow in millimeter-wavelength CO. We attribute the recently observed photometric and spectroscopic behavior to rotating circumstellar disk material located at separation ɑ ≈ 0.7(M_*/M_☉)^(1/3) AU from the continuum source, causing the semi-periodic dimming. Occultation of the central star as well as the bright inner disk and the accretion/outflow zones renders shocked gas in the inner part of the jet amenable to observation at the faint epochs. We discuss PTF 10nvg as a source exhibiting both accretion-driven (perhaps analogous to V1647 Ori) and extinction-driven (perhaps analogous to UX Ori or GM Cep) high-amplitude variability phenomena.
Gravitational lensing by point masses on regular grid points

It is shown that gravitational lensing by point masses arranged in an infinitely extended regular lattice can be studied (semi-)analytically. In particular, we draw the critical curves and the caustic networks for the lenses arranged in regular-polygonal - square, equilateral triangle, regular hexagon - grids. From this, the mean number of positive parity images as a function of the average optical depth is derived and compared to the case of the infinitely extended field of randomly distributed lenses. We find that the high degree of the symmetry in the lattice arrangement leads to a significant bias towards cancelling of the shear caused by the neighbouring lenses on a given lens position and lensing behaviour that is qualitatively distinct from the random star field. We also discuss some possible connections to more realistic lensing scenarios.
A global photometric analysis of 2MASS calibration data

We present results from the application of a global photometric calibration (GPC) procedure to calibration data from the first 2 years of the Two Micron All Sky Survey (2MASS). The GPC algorithm uses photometry of both primary standards and moderately bright "tracer" stars in 35 2MASS calibration fields. During the first 2 years of the survey, each standard was observed on approximately 50 nights, with about 900 individual measurements. Based on the photometry of primary standard stars and secondary tracer stars and under the assumption that the nightly zero-point drift is linear, the GPC ties together all calibration fields and all survey nights simultaneously, producing a globally optimized solution. Calibration solutions for the Northern and Southern Hemisphere observatories are found separately and are tested for global consistency based on common fields near the celestial equator. Several results from the GPC are presented, including establishing candidate secondary standards, monitoring of near-infrared atmospheric extinction coefficients, and verification of the global validity of the standards. The solution gives long-term averages of the atmospheric extinction coefficients (in magnitudes per air mass), AJ = 0.096, AH = 0.026, A = 0.066 (north) and AJ = 0.092, AH = 0.031, A = 0.065 (south), with formal error of 0.001. The residuals show small seasonal variations, most likely due to changing atmospheric content of water vapor. Extension of the GPC to ~100 field stars in each of the 35 calibration fields yields a catalog of more than 2000 photometric standards ranging from the 10th to 14th magnitude, with photometry that is globally consistent to ~1%.
A surface intersection algorithm based on loop detection

A robust and efficient surface intersection algorithm that is implementable in floating point arithmetic, accepts surfaces algebraic or otherwise and which operates without human supervision is critical to boundary representation solid modeling. To the author's knowledge, no such algorithms has been developed. All tolerance-based subdivision algorithms will fail on surfaces with sufficiently small intersections. Algebraic techniques, while promising robustness, are presently too slow to be practical and do not accept non-algebraic surfaces. Algorithms based on loop detection hold promise. They do not require tolerances except those associated with machine associated with machine arithmetic, and can handle any surface for which there is a method to construct bounds on the surface and its Gauss map. Published loop detection algorithms are, however, still too slow and do not deal with singularities. We present a new loop detection criterion and discuss its use in a surface intersection algorithms. The algorithm, like other loop detection based intersection algorithms, subdivides the surfaces into pairs of sub-patches which do not intersect in any closed loops. This paper presents new strategies for subdividing surfaces in a way that causes the algorithms to run quickly even when the intersection curve(s) contain(s) singularities.
Lens Design Using Group Indices of Refraction

Abstract An approach to lens design is described in which the ratio of the group velocity to the speed of light (the group index) in glass is used, in conjunction with the more familiar phase index of refraction, to control certain chromatic properties of a system of thin lenses in contact. It is shown that, at the wavelength of a maximum or minimum (where the phase power of a lens is locally independent of wavelength), the group power is equal to the phase power. It is further shown that, in a lens consisting of three or more elements, the phase and group powers can be constrained to be both equal and independent of wavelength (achromatic) at one or more wavelengths. In the neighbourhood of such wavelengths, both the first and the second derivatives of phase power with respect to wavelength are zero, giving this type of lens (in principle) an exceptionally high degree of achromatism not previously described, herein called group achromatism. The first-order design of thin-lens systems is illustrated by ex...
Cimiracemates A-D, phenylpropanoid esters from the rhizomes of Cimicifuga racemosa

Four phenylpropanoid esters, cimiracemates A-D (1-4), along with three known compounds, isoferulic acid, ferulic acid and methyl caffeate were isolated from the EtOAc fraction of the rhizome of Cimicifuga racemosa. The structures of the esters were elucidated by means of spectral data, including 2D NMR spectroscopy.
Diversity reservation ALOHA

A multiaccess protocol suitable for packet satellite broadcast channels is introduced in this paper. The proposed protocol, called diversity reservation ALOHA (DRA) combines the essential features of announced retransmission random access (ARRA). diversity ALOHA, and a reservation scheme with a slotted ALOHA reservation channel to achieve the goals of improved delay-throughput characteristics and high channel utilization. Two versions of DRA protocols are analyzed. In scheme 1, called DRA with reservation cleared (DRA-RC), no global queue information is required for a user to access the channel. In this version, even a successful transmission of reservation requests will be cleared from the system if it causes overflow. The second scheme, called DRA with reservation delayed (DRA-RD), establishes a global queue distributed at users' terminals, so that users with successful transmission of reservation requests are assured of access rights although transmission may be delayed to later fames. Important system performance measures, such as activity-factor-throughput characteristics, for DRA-RC and DRA-RD are compared with those of ARRA. Examples of numerical results show that with system parameters properly chosen, substantial increases in attainable channel utilization are possible. Furthermore, the use of diversity for reservation allows a smaller packet delay especially under light traffic conditions. The analysis is validated in light of the simulation results.
Line emission from galaxies at high redshift.

The results of a multifaceted search for spectral-line emission from galaxies at high redshift are presented. Deep two-dimensional spectra of four blank sky fields were taken at the Muliple Mirror Telescope (MMT) at wavelengths corresponding to redshifted Lyman alpha emission in the range 2.7 < z < 4.7, and the resulting nondetections are used to place upper limits on the space density of randomly distributed Ly-alpha emitters. Although the predictions of a conservative model of galaxy formation incorporating cold dark matter are not excluded in a statistical sense, the search would have detected star-forming dwarf galaxies comparable to the Magellanic Clouds at z = 3, given minimal extinction by dust. The Goddard Fabry-Perot Imager, a piezoelectrically controlled tuneable narrow-band filter system with a stand-alone CCD, was developed and tested, and used a the Kitt Peak National Observatory (KPNO) 4-m telescope to image the damped Ly-alpha absorbing clouds toward three high-redshift QSOs in the light of redshifted Ly-alpha. A companion galaxy to one of the damped systems was discovered, confirmed with follow-up spectroscopy, and its properties are presented and discussed. The companion exhibits strong Ly-alpha and weak C IV lambda-1550 and He II lambda-1640 emission lines, and is apparently producing stars at a rate of 5-10 solar mass yr-1. The implications of the companion's proximity to the damped cloud are analyzed in view of the previous nondetections, and a lower limit to the spatial correlation function of the damped Ly-alpha systems with galaxies is given. Spectroscopic limits on Ly-alpha emission from seven damped systems, including some known to have low chemical and dust abundances, imply levels of star formation lt 1 solar mass yr-1, but extinction by dust in some cases may cause an underestimation of these rates. With near-infrared spectrographs at the MMT and the KPNO 4-m telescope, eight damped Ly-alpha systems were searched for spectral lines characteristic of star-formation regions but redshifted from the optical into the near infrared. A possible detection of [O III] lambda-3727 and H-beta from one system implies a star-formation rate on the order of 100 solar mass yr-1, though the remainder of the observations produced nondetections. The implications for galaxy formation and evolution at high redshift are discussed.