cssi/SciSciGPT-SciSciNet huggingface dataset:
THE R STARS: CARBON STARS OF A DIFFERENT KIND

After ~16 years of radial-velocity observations of a sample of 22 R-type carbon stars, no evidence for binary motion has been detected in any of them. This is surprising considering that approximately 20% of normal late-type giants are spectroscopic binaries, and the fraction is close to 100% in barium, CH, and subgiant/dwarf CH and barium stars. It is suggested, therefore, that a process that has caused the mixing of carbon to the surface of these stars cannot act in a wide binary system. Possibly, the R stars were once all binaries, but with separations that would not allow them to evolve completely up the giant and asymptotic giant branchs without coalescing. This coalescence may be the agent which causes carbon produced in the helium-core flash to be mixed outwards to a region where convection zones can bring it to the surface of the star.
Characterization of α-halo-imine intermediates derived from halogenation of dehydroamino acid derivatives

Abstract An efficient one-pot Erlenmeyer-Plochl reaction affords high yields of optically active aliphatic dehydroamino acid derivatives. Subsequent halogenation with NBS or NIS yields the α-halo-imine derivatives which undergo kinetically controlled tautomerization with Et 3 N, resulting in increased E selectivity. Isomerization of these derivatives in the presence of strong base (DABCO) results in exclusive formation of the more stable Z vinyl bromides. High yields of the β-halo-dehydroamino acids are obtained in all cases.
On testing for zero polynomials by a set of points with bounded precision

We consider a general methodology proposed by Chen and Kao for testing polynomial identities. We prove that the test cannot be completely derandomized by any specified set of rational approximations to algebraic numbers up to a polynomial number of bits. The proof is a direct application of Dirichlet's box principle. We also give some number theoretic estimates for the likelihood of a multiplicatively independent sequence of integers which can be used in their algorithm.
Zinc oxide nanostructures: from growth to application

Zinc oxide’s (ZnO) physical and chemical properties make it a viable and extremely attractive compound to use in a variety of nanotechnology applications. Some of these applications include biomedical, energy, sensors, and optics. As the research in ZnO nanostructures continue to grow, it has inspired a whole host of new innovative applications. Complementing its unique chemical qualities, it also has a simple crystal-growth technology and offers significantly lower fabrication costs when compared to other semiconductors used in nanotechnology. Several processes have been developed in order to synthesize high quality ZnO nanostructures—specifically in the case of nanowires. Here we offer a comprehensive review on the growth methods currently employed in research, industry, and academia to understand what protocols are available to meet specific needs in nanotechnology. Methods examined include: the vapor–liquid–solid, physical vapor deposition, chemical vapor deposition, metal–organic chemical vapor deposition, and the hydrothermal-based chemical approach. Each of these methods is discussed and their strengths and weaknesses are analyzed with objective comparison metrics. In addition, we study the current state-of-the-art applications employing ZnO nanostructures at their core. A historical perspective on the evolution of the field and the accompanying literature are also presented.
Design and synthesis of a series of facially coordinating tridentate ligands containing an N2O donor atom set

Abstract The preparation of a series of facially coordinating tridentate ligands is described. The N2O ligands contain a phenol and either two imidazole, two pyridine or two pyrazole donor atoms.
Gravitationally induced convection during directional solidification of off-eutectic Mn-Bi alloys

The effects of thermal and solute gradient, gravity induced convection during vertical directional solidification, on longitudinal macrosegregation of Bi and Mn rich off-eutectic starting compositions, has been studied as a function of composition, growth velocity and gravity vector orientation. Since the morphology of these alloys is characterized by an aligned, rodlike permanent magnet composite when grown cooperatively, the magnetic properties were used to measure composition segregation and the transition from dendritic to composite growth. Severe macrosegregation was observed in all cases studied and the degree of convection inferred by modeling the observed composition segregation using a stagnant film approach. Morphological stability was found to follow a constitutional supercooling-type law for both Bi and Mn rich compositions.
Lectures on Supersymmetry Breaking

We review the subject of spontaneous supersymmetry breaking. First we consider supersymmetry breaking in a semiclassical theory. We illustrate it with several examples, demonstrating different phenomena, including metastable supersymmetry breaking. Then we give a brief review of the dynamics of supersymmetric gauge theories. Finally, we use this dynamics to present various mechanisms for dynamical supersymmetry breaking. This paper is based on lectures given by the authors in 2007, at various schools.
Oxidation of indoles with pyridinium bromide perbromide: a simple and efficient synthesis of 7-azaoxindoles

Abstract Indoles and azaindoles on treatment with pyridinium bromide perbromide (PBPB) in t-butanol give 3,3-dibromooxindoles which, upon further reduction, yield the corresponding oxindoles.
Measurement of endogenous Leucine enkephalin in canine caudate nuclei and hypothalami with high-performance liquid chromatography and field-desorption mass spectrometry.

Abstract For the first time, endogenous amounts of Leu-enkephalin are measured in brain tissue with a technique preserving integrity of the entire molecular structure of the neuropeptide. Field-desorption mass spectrometry enables measurement of picomole amounts of endogenous, chemically underivatized Leu-enkephalin in canine caudate nuclei and hypothalami. The optimal sensitivity and resolution of high-performance liquid chromatography is coupled with maximal molecular specificity of field-desorption mass spectrometry to measure enkephalins in caudate nuclei and hypothalami from dog brains. This novel combination of two recent instrumental methodologies provides a firm molecular basis for calibrating the radioimmunoassay measurement of endogenous levels of biologically active brain neuropeptides.
Design of multi-component structural systems for optimal layout topology and joint locations

Present day topology optimization techniques for continuum structures consider the design of single structural components, while most real life engineering design problems involve multiple components or structures. It is therefore necessary to have a methodology that can address the design of multi-component systems and generate designs for the optimal layouts of individual structures and locations for interconnections. The interconnections include supports provided by the ground, joints and rigid connections like rivets, bolts and welds between components. While topology optimization of structures has been extensively researched, relatively little work has been done on optimizing the locations of the interconnections. In this research, a method to model and define domains for the interconnections has been developed. The optimization process redistributes material in the component design domains and locates the connections optimally based on an energy criterion. Some practical design examples are used to illustrate the capability of this method.
Complexity and Empirical Economics

This article explores the state of interplay between recent efforts to introduce complex systems methods into economics and the understanding of empirical phenomena. The empirical side of economic complexity may be divided into three general branches: historical studies, the identification of power and scaling laws, and analyses of social interactions. I argue that, while providing useful ‘stylised facts’, none of these empirical approaches has produced compelling evidence that economic contexts exhibit the substantive microstructure or properties of complex systems. This failure reflects inadequate attention to identification problems. Identification analysis should therefore be at the centre of future work on the empirics of complexity.
Revenue maximization with a single sample

Abstract This paper pursues auctions that are prior-independent. The goal is to design an auction such that, whatever the underlying valuation distribution, its expected revenue is almost as large as that of an optimal auction tailored for that distribution. We propose the prior-independent Single Sample mechanism, which is essentially the Vickrey–Clarke–Groves (VCG) mechanism, supplemented with reserve prices chosen at random from participants' bids. We prove that under reasonably general assumptions, this mechanism simultaneously approximates all Bayesian-optimal mechanisms for all valuation distributions. Conceptually, our analysis shows that even a single sample from a distribution — some bidder's valuation — is sufficient information to obtain near-optimal expected revenue.
Women, Harm Reduction and HIV

Gender shapes the experience of drug use and its associated risks. In most parts of the world, however, harm reduction and drug treatment programmes that tailor their services to meet women's needs are rare or nonexistent. Many existing services inadvertently exclude women, and discriminatory policies and social stigma drive women drug users from care and expose them to human rights abuses. Women drug users often provide sex in exchange for housing, sustenance and protection, suffer violence from sexual partners and practise unsafe sex. This paper, drawing upon evidence from existing studies, examines ways in which gender-related factors can increase women drug users' vulnerability and decrease their access to harm reduction, drug treatment and sexual and reproductive health services. It recommends designing services with low-threshold access for women drug users that help them to become more independent, involving the women in designing services and policies, making programmes available for mothers, incorporating sexual and reproductive health into harm reduction services, providing gender-sensitive drug treatment and integrated harm reduction programmes for drug-using sex workers, connecting with domestic violence and rape prevention services and educating mainstream providers. Overall, investigating the circumstances women drug users face will help to formulate policies and programmes that better serve women who use drugs.
Large-Eddy Simulation of Separation Control for Flow over a Wall-Mounted Hump

This work describes an implicit large-eddy simulation (LES) for active control of flow over a wall-mounted hump. Both steady suction and oscillatory blowing and suction are compared to baseline conditions with no flow control. This simulation models an experiment conducted by NASA which was one of the test cases in their 2004 CFD Validation on Synthetic Jets and Turbulent Separation Control Workshop. A previous LES of the baseline case with the current scheme demonstrated significantly better agreement with the experimental flow physics than RANS in the separated region downstream of the hump. The current work concludes that this also holds for the cases using active control. The LES is accomplished using an implicit parallel flow solver that is based on an approximately-factored time-integration method using fourth-order spatial compact-dierence formulations and a high-order filtering strategy. To properly resolve the flow for this LES, the Reynolds number of 9.36 ◊ 10 5 used in the experiment was reduced to 2.0 ◊ 10 5 . Eects of lowering the Reynolds number were previously investigated using RANS. Flow features of the active control cases are compared with the baseline case, each other, and experimental data. The active control LES cases matches experimental data significantly better in the recirculation region than RANS. The baseline and steady suction LES separation reattachment lengths are within 2% and 4%, respectively, of the experimental locations. These simulations achieve very good agreement with the experimental surface pressure coecient, skin friction coefficient, mean velocity profiles, Reynolds stresses, and flow reattachment location. Because of the lower Reynolds number, the oscillatory blowing and suction flow control only has about 25% of the eectiveness of that observed in the experiment. The LES separation reattachment length is 10% longer than its experimental counterpart. Other flow quantities display favorable agreement with experimental data. Results demonstrate that both steady suction and oscillatory blowing and suction can be properly simulated by LES and eectively reduce the size of the separated flow region.
Generalized Fibonacci recurrences and the lex-least de Bruijn sequence

The skew of a binary string is the difference between the number of zeroes and the number of ones, while the length of the string is the sum of these two numbers. We consider certain suffixes of the lexicographically-least de Bruijn sequence at natural breakpoints of the binary string. We show that the skew and length of these suffixes are enumerated by sequences generalizing the Fibonacci and Lucas numbers, respectively.
Iron-catalyzed cross-coupling of unactivated secondary alkyl thio ethers and sulfones with aryl Grignard reagents.

The first systematic investigation of unactivated aliphatic sulfur compounds as electrophiles in transition-metal-catalyzed cross-coupling are described. Initial studies focused on discerning the structural and electronic features of the organosulfur substrate that enable the challenging oxidative addition to the C(sp3)–S bond. Through extensive optimization efforts, an Fe(acac)3-catalyzed cross-coupling of unactivated alkyl aryl thio ethers with aryl Grignard reagents was realized in which a nitrogen “directing group” on the S-aryl moiety of the thio ether served a critical role in facilitating the oxidative addition step. In addition, alkyl phenyl sulfones were found to be effective electrophiles in the Fe(acac)3-catalyzed cross-coupling with aryl Grignard reagents. For the latter class of electrophile, a thorough assessment of the various reaction parameters revealed a dramatic enhancement in reaction efficiency with an excess of TMEDA (8.0 equiv). The optimized reaction protocol was used to evaluate t...
Safe to the last instruction: automated verification of a type-safe operating system

Typed assembly language (TAL) and Hoare logic can verify the absence of many kinds of errors in low-level code. We use TAL and Hoare logic to achieve highly automated, static verification of the safety of a new operating system called Verve. Our techniques and tools mechanically verify the safety of every assembly language instruction in the operating system, run-time system, drivers, and applications (in fact, every part of the system software except the boot loader). Verve consists of a "Nucleus" that provides primitive access to hardware and memory, a kernel that builds services on top of the Nucleus, and applications that run on top of the kernel. The Nucleus, written in verified assembly language, implements allocation, garbage collection, multiple stacks, interrupt handling, and device access. The kernel, written in C# and compiled to TAL, builds higher-level services, such as preemptive threads, on top of the Nucleus. A TAL checker verifies the safety of the kernel and applications. A Hoare-style verifier with an automated theorem prover verifies both the safety and correctness of the Nucleus. Verve is, to the best of our knowledge, the first operating system mechanically verified to guarantee both type and memory safety. More generally, Verve's approach demonstrates a practical way to mix high-level typed code with low-level untyped code in a verifiably safe manner.
NARROWBAND IMAGING OF ESCAPING LYMAN-CONTINUUM EMISSION IN THE SSA22 FIELD* , **

We present the results of an ultradeep, narrowband imaging survey for Lyman-continuum (LyC) emission at z ~ 3 in the SSA22a field. We employ a custom narrowband filter centered at λ = 3640 A (NB3640), which probes the LyC region for galaxies at z ≥ 3.06. We also analyze new and archival NB4980 imaging tuned to the wavelength of the Lyα emission line at z = 3.09, and archival broadband B, V, and R images of the non-ionizing UV continuum. Our NB3640 images contain 26 z ≥ 3.06 Lyman break galaxies (LBGs) as well as a set of 130 Lyα emitters (LAEs), identified by their excess NB4980 flux relative to the BV continuum. Six LBGs and 28 LAEs are detected in the NB3640 image. LBGs appear to span a range of NB3640-R colors, while LAEs appear bimodal in their NB3640-R properties. We estimate average UV-to-LyC flux density ratios, corrected for foreground contamination and intergalactic medium absorption, finding (F_(UV)/F_(LyC)^(LBG)_(corr) = 11.3^(+10.3)_(–5.4), which implies an LBG LyC escape fraction f^(LyC)_(esc) ~ 0.1, and (F_(UV)/F_(LyC)^(LAE)_(corr) = 2.2^(+0.9)_(–0.6). The strikingly blue LAE flux density ratios defy interpretation in terms of standard stellar population models. Assuming (F _(UV)/F_(LyC)^(LBG)_(corr) applies down to L = 0.1L^*, we estimate a galaxy contribution to the intergalactic hydrogen ionization rate that is consistent with independent estimates based on the Lyα forest opacity at z sime 3. If we assume that (F_(UV)/F_(LyC)^(LAE)_(corr) holds at the faintest luminosities, the galaxy contribution significantly exceeds that inferred from the Lyα forest. We interpret our results in terms of a model where LyC photons escape over only ~10%-20% of solid angle. When advantageously oriented, a galaxy will exhibit a low UV-to-LyC ratio, an effect enhanced for more compact galaxies. This model, however, does not adequately explain the extremely blue NB3640-R colors measured for some LAEs in our sample. Further follow-up study of these faint LAEs is crucial, given the potentially important contribution similar objects make to the process of reionization.
Remarks on the stack of coherent algebras

We consider the stack of coherent algebras with proper support, a moduli problem generalizing Alexeev and Knutson's stack of branchvarieties to the case of an Artin stack. The main results are proofs of the existence of Quot and Hom spaces in greater generality than is currently known and several applications to Alexeev and Knutson's original construction: a proof that the stack of branchvarieties is always algebraic, that limits of one-dimensional families always exist, and that the connected components of the stack of branchvarieties are proper over the base under certain hypotheses on the ambient stack.
Optimal Locations of Pseudolites for Differential GPS

Because of the announced DOD policy to degrade GPS accuracy, Differential GPS has assumed increasing importance. Furthermore, the delay in operational deployment of the NAVSTAR satellites has focused increased attention on the use of pseudo-satellites (pseudolites or PLs) to enhance accuracy and provide earlier operational capability. Pseudolites perform a double function: they both calibrate the local ranging errors and significantly improve the user’s geometry as measured by GDOP (Geometric Dilution of Precision). This paper examines the following problem: What is the best location for a PL when one considers the worst possible satellite outage in twenty-four hours? What is the resulting worst case GDOP? Both single and dual PL systems are considered, and the results are extrapolated to expected user receiver performance (horizontal and vertical errors). The results indicate that a dual PL system will outperform the satellite-only GPS system, even with a worst case satellite outage. In addition, there should be negligible degradation during periods when the military intentionally reduces ephemeris or clock accuracy. Furthermore, the accuracy of such a system would provide aircraft positioning very close to Category I FAA landing requirements.
Electron Backstreaming Determination for Ion Thrusters

Electron backstreaming in ion thrusters is caused by the random flux of beam electrons past a potential barrier established by the accel grid. A technique that integrates this flux over the radial extent of the barrier reveals important aspects of electron backstreaming phenomena for individual beamlets, across the thruster beam, and throughout thruster life. For individual beamlets it was found that over 99% of the electron backstreaming occurs in a small annulus at the center of the beamlet that is less than 20% the area of the beamlet at the potential barrier established by the accel grid. For the thruster beam it was found that over 99% of the backstreaming current occurs inside of r = 6 cm for the over 28 cm diameter NSTAR grid. Initial validation against ELT data shows that the technique provides the correct behavior and magnitude of electron backstreaming limit, V(sub ebs). From the sensitivity analyses it is apparent that accel grid chamfering may be the dominant mechanism contributing to the sharp rise in the absolute value of V(sub ebs) observed in the ELT but does not explain the rise in ion transparency. Grid gap change also contributes to the absolute value of V(sub ebs) rise and large rises in ion transparency with thruster life for the center gridlet. Screen grid erosion contributes generally to rises in the absolute value of V(sub ebs) and ion transparency, but for the assumptions used herein, it appears to not have as much of an effect chamfering or grid gap change. Overall, it is apparent that accel grid chamfering, grid gap change, and screen grid erosion are important to the increase in electron backstreaming observed during the ELT.
Estimating the speedup in parallel parsing

A method for estimating the speedup for asynchronous bottom-up parallel parsing is presented. Two models for bottom-up parallel parsing are proposed, and the speedup for each of the two models is estimated. The speedup obtained for model A is a very close to the simulation result already available in literature; however, the model is restrictive because it can only communicate with its immediate left and right neighbors. This increases the processor coordination and interprocessor communication times. Model B, while showing a greater speedup time, is expensive to construct when the number of processors is large. >
Theoretical Development for Depth Profiling of Stratified Layers Using Variable Angle ATR

The theory allowing depth profile information to be recovered from variable-angle attenuated total reflection spectroscopy is shown for both perpendicular and parallel polarizations. The errors invoked by the necessary approximations are evaluated by comparison with exact optical simulations using dispersion theory.
Ferromagnetism from localized deep impurities in magnetic semiconductors

We propose that localized defects in magnetic semiconductors act as deep impurities and can be described by the Anderson model. Within this model, hybridization of $d$ orbitals and $p$ orbitals gives rise to a non-Ruderman-Kittel-Kasuya-Yosida (RKKY) indirect exchange mechanism, when the localized $d$ electrons are exchanged through both conduction and valence bands. For semiconductors with indirect band gap the non-RKKY part of exchange integral is antiferromagnetic, which suppresses ferromagnetism. In case of direct band gap, this exchange mechanism can, under certain conditions, lead to enhancement of ferromagnetism. The indirect exchange integral is much stronger than RKKY, and can be sufficiently long range. Thus, a potentially new class of high-temperature magnetic semiconductors emerges, where doped carriers are not necessary to mediate ferromagnetism. Curie temperatures in such magnetic semiconductors are determined mostly by the interaction between localized impurities, not Zener mechanism. This effect could also be responsible for unusually high Curie temperatures in some magnetic semiconductors with direct band gap.
Inside the Supernova: A Powerful Convective Engine

We present an extensive study of the inception of supernova explosions by following the evolution of the cores of two massive stars (15 and 25 Solar mass) in multidimension. Our calculations begin at the onset of core collapse and stop several hundred milliseconds after the bounce, at which time successful explosions of the appropriate magnitude have been obtained. Similar to the classical delayed explosion mechanism of Wilson, the explosion is powered by the heating of the envelope due to neutrinos emitted by the protoneutron star as it radiates the gravitational energy liberated by the collapse. However, as was shown by Herant, Benz, & Colgate, this heating generates strong convection outside the neutrinosphere, which we demonstrate to be critical to the explosion. By breaking a purely stratified hydrostatic equilibrium, convection moves the nascent supernova away from a delicate radiative equilibrium between neutrino emission and absorption, Thus, unlike what has been observed in one-dimensional calculations, explosions are rendered quite insensitive to the details of the physical input parameters such as neutrino cross sections or nuclear equation of state parameters. As a confirmation, our comparative one-dimensional calculations with identical microphysics, but in which convection cannot occur, lead to dramatic failures. Guided by our numerical results, we have developed a paradigm for the supernova explosion mechanism. We view a supernova as an open cycle thermodynamic engine in which a reservoir of low-entropy matter (the envelope) is thermally coupled and physically connected to a hot bath (the protoneutron star) by a neutrino flux, and by hydrodynamic instabilities. This paradigm does not invoke new or modified physics over previous treatments, but relies on compellingly straightforward thermodynamic arguments. It provides a robust and self-regulated explosion mechanism to power supernovae that is effective under a wide range of physical parameters.
A new blur kernel estimator and comparisons to state-of-the-art

This paper presents a simple, fast, and robust method to estimate the blur kernel model, support size, and its parameters directly from a blurry image. The edge profile method eliminates the need for searching the parameter space. In addition, this edge profile method is highly local and can provide a measure of asymmetry and spatial variation, which allows one to make an informed decision on whether to use a symmetric or asymmetric, spatially varying or non-varying blur kernel over an image. Furthermore, the edge profile method is relatively robust to image noise. We show how to utilize the concepts behind the statistical tools for fitting data distributions to analytically obtain an estimate of the blur kernel that incorporates blur from all sources, including factors inherent in the imaging system. Comparisons are presented of the deblurring results from this method to current common practices for real-world (VNIR, SWIR, MWIR, and active IR) imagery. The effect of image noise on this method is compared to the effect of noise on other methods.
Nickel-Containing Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase†,‡

This article reviews an enzyme with two important catalytic activities, carbon monoxide dehydrogenase (CODH) (reaction 1) and acetyl-CoA synthase (ACS) (reaction 2). These reactions are key to an autotrophic pathway that has become known as the reductive acetyl-CoA or the Wood/Ljungdahl pathway. ACS also catalyzes two exchange reactions that have been valuable in elucidating the mechanism of acetyl-CoA synthesis: an exchange reaction between CO and the carbonyl group of acetyl-CoA (reaction 3) and an exchange reaction between free CoA and the CoA moiety of acetyl-CoA (reaction 4). Ten years ago, one of the authors (Ragsdale) and Harland Wood, first proposed that the CODH from acetogenic bacteria catalyzes the final steps in acetyl-CoA synthesis and, therefore, should be renamed acetyl-CoA synthase. It was previously accepted that these steps occurred on a cobalt-containing corrinoid protein. This was a controversial proposal that required the existence of carbonyl, methyl, and acetyl enzyme adducts. Proof of this postulate was nontrivial since it required the characterization of enzyme-bound intermediates. With the goal of detecting and characterizing intermediates in the pathway, the authors` laboratory and others began to probe the enzyme in the resting state and at different stages of the catalytic cycle with sensitive spectroscopic methods.more » This review summarizes the fruits of the combined labor of the laboratories working on this interesting problem. 237 refs.« less
Three expressions of the need for variety1

This study aimed to measure three rationally distinct forms of the need for variety as expressed in thematic apperception, and to obtain the relatic ships among them and between each of them and other variables with which the should or should not be correlated. Sixty-two male subjects were tested fox all variables. The relationships among the three fantasy measures–novelty of productions, curiosity, and desire for novelty–were consistent with assuming that they represent different forms of the need for variety. In addition, novelty of productions correlated positively with complexity and internal exploration, and negatively with external exploration. Curiosity correlated positively with external exploration and n achievement, and negatively with nonverbal productivity. Evidence for discriminant validity was also obtained.
Novel Terphenyls as Selective Cyclooxygenase-2 Inhibitors and Orally Active Anti-inflammatory Agents

A novel series of terphenyl methyl sulfones and sulfonamides have been shown to be highly potent and selective cyclooxygenase-2 (COX-2) inhibitors. The sulfonamide analogs 17 and 21 were found to be much more potent COX-2 inhibitors and orally active anti-inflammatory agents than the corresponding methyl sulfone analogs 16 and 20, respectively, albeit with some decrease in COX-2 selectivity. Structure−activity relationship studies have determined that incorporation of two fluorine atoms in the central phenyl group, as in 20 and 21, is extremely advantageous for both in vitro COX-2 potency and selectivity as well as in vivo activity. Several noticeable examples in the 1,2-diaryl-4,5-difluorobenzenesulfonamide series are 21a−c,k,l,n (COX-2, IC50 = 0.002−0.004 μM), in which all have in vitro COX-1/COX-2 selectivity >1000. In addition, sulfonamides 21a,b,d,g,j,m,n,q were shown to have greatly enhanced oral activity with more than 90% inhibition of prostaglandin E2 production in the air pouch model of inflamma...
Hyperacute rejection of mouse lung by human blood: characterization of the model and the role of complement.

BACKGROUND The pathophysiology of hyperacute lung rejection (HALR) is not fully understood. A mouse model of HALR by human blood would be valuable to efficiently dissect the molecular mechanisms underlying this complex process, but it has not been described. METHODS We developed a xenogenic mouse lung-perfusion model. Perfusion with heparinized autologous blood (n=3) was compared with human blood unmodified (n=7) or pretreated with C1 inhibitor (n=5) or soluble complement receptor type 1 (n=6) at unchanged flow conditions. RESULTS Perfusion with autologous blood was associated with stable physiologic parameters and no overt evidence of lung injury for up to 2 hr. Pulmonary artery perfusion pressure increased rapidly after introduction of unmodified human blood, plasma anti-Gal(alpha)1,3Gal antibodies declined (90% immunoglobulin [Ig]M, 80% IgG), and lungs reliably met survival endpoints within 11 min (median 10 min, confidence interval [CI]: 9-11). Human Ig and neutrophils were rapidly sequestered in the lung. Survival was significantly prolonged in the soluble complement receptor type 1 group (36 min, CI: 26-46) (P<0.01) and in the C1 inhibitor group (23 min, CI: 21-25) (P<0.05), and pulmonary vascular resistance elevation and complement activation were significantly attenuated but not prevented. CONCLUSIONS Hyperacute rejection of mouse lung by human blood occurs with kinetics, physiology, and histology closely analogous to the pig-to-human model. In addition, as in that model, neither of two potent soluble-phase complement inhibitors prevented complement activation or HALR. We conclude that the mouse lung model is relevant to dissect the cellular and molecular mechanisms governing HALR.
On some conformally invariant fully nonlinear equations

We will report some results concerning the Yaniabe problem and the Niren­ berg problem. Related topics will also be discussed. Such studies have led to new results on some conformally invariant fully nonlinear equations arising from geometry. We will also present these results which include some Liouville type theorems, Harnack type inequalities, existence and compactness of solutions to some nonlinear version of the Yamabe problem.
Salt weathering on Mars

Mariner 9 photographs of Mars indicate that significant erosion has occurred on that planet. Although several possible erosion mechanisms have been proposed, most terrestrial weathering mechanisms cannot function in the present Martian environment. Salt weathering, believed to be active in the Antarctic dry valleys, is especially suited to Mars, given the presence of salts and small amounts of water. Volcanic salts are probably available, and the association of salts and water is likely from both thermodynamic and geologic considerations.
Evaluation of remote backup algorithms for transaction-processing systems

A remote backup is a copy of a primary database maintained at a geographically separate location and is used to increase data availability. Remote backup systems are typically log-based and can be classified into 2-safe and 1-safe, depending on whether transactions commit at both sites simultaneously or first commit at the primary and are later propagated to the backup. We have built an experimental database system on which we evaluated the performance of the epoch and the dependency reconstruction algorithms, two 1-safe algorithms we have developed. We compared the 1-safe with the 2-safe approach under various conditions.
CYTOCHEMISTRY OF GOLGI FRACTIONS PREPARED FROM RAT LIVER

Cytochemical tests for several marker enzymes were applied to liver tissue and to the three Golgi fractions (GF1, GF2, GF3) separated by the procedure of Ehrenreich et al. from liver homogenates of alcohol-treated rats. 5'-Nucleotidase (AMPase) reaction product was found in all three fractions but in different locations: It occurred along the inside of the membrane of VLDL-filled vacuoles in GF1 and GF2, and along the outside of the cisternal membranes in GF3. In the latter it was restricted to the dilated cisternal rims and was absent from the cisternal centers. The AMPase activity found in the fractions by biochemical assay is therefore indigenous to Golgi components and is not due to contamination by plasma membrane. Acid phosphatase (AcPase) reaction product was detected within lysosomal contaminants in GF1 and within many VLDL-filled vacuoles in GF1 and GF2, indicating that AcPase activity is due not only to contaminating lysosomes, but also to enzyme indigenous to Golgi secretory vacuoles. G-6-Pase reaction product was present in GF3 and within contaminating endoplasmic reticulum fragments, but not in other fractions. Thiamine pyrophosphatase (TPPase) was localized to some of the VLDL-filled vacuoles and cisternae in GF1 and GF2, and was not found in the cisternae in GF3. The results demonstrate the usefulness of cytochemical methods in monitoring the fractionation procedure: They have (a) allowed a reliable identification of contaminants, (b) made possible a distinction between indigenous and contaminating activities, and (c) shown, primarily by the results of the TPPase test, that the procedure achieves a meaningful subfractionation of Golgi elements, with GF1 and GF3, representing primarily trans-Golgi elements from the secretory Golgi face, and GF3 consisting largely of cis-Golgi components from the opposite face.
Power-law estimates for the central limit theorem for convex sets

Abstract We investigate the rate of convergence in the central limit theorem for convex sets established in [B. Klartag, A central limit theorem for convex sets, Invent. Math., in press. [8] ]. We obtain bounds with a power-law dependence on the dimension. These bounds are asymptotically better than the logarithmic estimates which follow from the original proof of the central limit theorem for convex sets.
Noncommutative Instantons Revisited

We find a new gauge in which U(1) noncommutative instantons are explicitly non-singular on noncommutative R4. We also present a pedagogical introduction into noncommutative gauge theories.
Holomorphic disks and topological invariants for closed three-manifolds

The aim of this article is to introduce certain topological invariants for closed, oriented three-manifolds Y, equipped with a Spiny structure. Given a Heegaard splitting of Y = U 0o U Σ U 1 , these theories are variants of the Lagrangian Floer homology for the g-fold symmetric product of Σ relative to certain totally real subspaces associated to U 0 and U 1 .
Inhibition of the Crevice Corrosion of Iron in Chloride Solutions by Chromate

The crevice corrosion of iron in neutral solutions is promoted by chloride ions and inhibited by chromate. For any given concentration of chloride in the range investigated , the crevice corrosion of iron can be inhibited by using a sufficient amount of chromate, with the concentration of chromate required decreasing with the concentration of chloride. A linear relationship is observed between the logarithm of the chloride ion activity and the logarithm of the minimum activity of chromate ion required for protection against crevice corrosion. This relationship is explained on the basis of competitive adsorption between aggressive (Cl−) and inhibitive ions within the crevice, with each ion adsorbing according to a Temkin isotherm. The steady‐state electrode potential of corroding iron within crevices is −620 to −660 mV vs. , independent of bulk solution composition and in reasonable agreement with the thermodynamic value calculated for an iron crevice or pit.
A lower bound for average values of dynamical Green’s functions

We provide a Mahler/Elkies-style lower bound for the average values of dynamical Green's functions on the projective line over an arbitrary valued field, and give some dynamical and arithmetic applications.
Multicomponent cycloadditions: the four-component [5+1+2+1] cycloaddition of vinylcyclopropanes, alkynes, and CO.

Prompted by the view that intermediates of transition metal-catalyzed reactions could be intercepted by one or more additional components, studies in our laboratory have led to the design and development of new three-component [5+2+1], [4+2+1], and [2+2+1] cycloadditions. These continuing studies have now led to the identification of a fundamentally new four-component [5+1+2+1] cycloaddition reaction of vinylcyclopropanes, alkynes and CO, yielding hydroxyindanone products in generally good yields. Terminal alkynes bearing aryl or alkyl groups are tolerated well. Substitution at any position of the VCP leads predictably to substituted hydroxyindanone products. Using a bis-alkynyl substrate, the reaction can be carried out bi-directionally, forming 10 C−C bonds and four new rings from seven components in a single, operationally simple process.
Multiepoch radial velocity observations of L dwarfs

We report on the development of a technique for precise radial velocity measurements of cool stars and brown dwarfs in the near infrared. Our technique is analogous to the iodine (I2) absorption cell method that has proven so successful in the optical regime. We rely on telluric CH4 absorption features to serve as a wavelength reference, relative to which we measure Doppler shifts of the CO and H2O features in the spectra of our targets. We apply this technique to high-resolution (R ≈ 50,000) spectra near 2.3 μm of nine L dwarfs taken with the Phoenix instrument on Gemini South and demonstrate a typical precision of 300 m s-1. We conduct simulations to estimate our expected precision and show that our performance is currently limited by the signal-to-noise ratio (S/N) of our data. We present estimates of the rotational velocities and systemic velocities of our targets. With our current data we are sensitive to companions with M sin i > 2 MJ in orbits with periods less than 3 days. We identify no companions in our current data set. Future observations with improved S/N should result in radial velocity precision of 100 m s-1 for L dwarfs.
Bhc-diol as a photolabile protecting group for aldehydes and ketones.

6-Bromo-4-(1,2-dihydroxyethyl)-7-hydroxycoumarin (Bhc-diol) can be used under simulated physiological conditions as a photoremovable protecting group for aldehydes and ketones. The single- and two-photon-induced release of benzaldehyde, piperonal, acetophenone, and cyclohexanone is demonstrated.
Optical Emission Band Morphologies of the Red Rectangle

We present narrowband images of the Red Rectangle (RR) Nebula that reveal the distinct morphologies of this intriguing nebula in different optical emission bands. The morphology of the RR nebula in blue luminescence (BL) and extended red emission (ERE) are almost mutually exclusive. We also present the optical detection of the circumbinary disk of the RR in the light of the BL. The total intensities from the two optical band emissions (BL and ERE) when summed over the nebula are of comparable magnitude. Their spatial distributions with respect to the embedded illumination sources lead us to suggest that they may be attributed to different ionization stages of the same family of carriers.
Countervailing Power and Chain Stores

The countervailing power of large buyers subdues the market power of sellers, but price concessions won by large buyers in upstream markets may or may not translate into lower prices downstream as Galbraith (American capitalism: The concept of countervailing power. Houghton Mifflin, Boston, 1952, Am Econ Rev 44:1–6, 1954) once contended. This paper presents a model that formalizes certain previously neglected elements of Galbraith’s argument, and shows that upstream price concessions may lead to lower downstream prices. In this model, a large retail chain store with countervailing power plays one large supplier off against another to win lower prices. An indirect effect of these interactions is that small retailers also pay lower prices, although not as low as the chain. Finally, competition among the retailers drives retail prices lower. The retail-price-restraining effect of the chain is stronger than the effect that is produced by the entry of an additional supplier.
Stability estimates in stationary inverse transport

We study the stability of the reconstruction of the scattering and absorption coefficients in a stationary linear transport equation from knowledge of the full albedo operator in dimension $n\geq3$. The albedo operator is defined as the mapping from the incoming boundary conditions to the outgoing transport solution at the boundary of a compact and convex domain. The uniqueness of the reconstruction was proved in [2, 3] and partial stability estimates were obtained in [12] for spatially independent scattering coefficients. We generalize these results and prove an $L^1$-stability estimate for spatially dependent scattering coefficients.
Linear functions on the classical matrix groups

Let M be a random matrix in the orthogonal group On, distributed according to Haar measure, and let A be a fixed n x n matrix over R such that Tr(AA t ) = n. Then the total variation distance of the random variable Tr(AM) to a standard normal random variable is bounded by 2√3 n-1 and this rate is sharp up to the constant. Analogous results are obtained for M a random unitary matrix and A a fixed n x n matrix over C. The proofs are applications of a new abstract normal approximation theorem which extends Stein's method of exchangeable pairs to situations in which continuous symmetries are present.
A Highly Doppler Blueshifted Fe-K Emission Line in the High-Redshift Qso Pks 2149-306

We report the results from an ASCA observation of the high-luminosity, radioloud quasar PKS 2149-306 (redshift 2.345), covering the approximately 1.7 - 30 keV band in the quasar-frame. We find the source to have a luminosity of approximately 6 x 10(exp 47) ergs/s in the 2 - 10 keV band (quasar frame). We detect an emission line centered at approximately 17 keV in the quasar frame. Line emission at this energy has not been observed in any other active galaxy or quasar to date. We present evidence rejecting the possibility that this line is the result of instrumental artifacts, or a serendipitous source. The most likely explanation is blueshifted Fe-K emission (the equivalent width, is EW approximately 300 +/- 200 eV, quasar frame). Bulk velocities of the order of 0.75c are implied by the data. We show that Fe-K line photons originating in an accretion disk and Compton-scattering off a leptonic jet aligned along the disk axis can account for the emission line. Curiously. if the emission-line feature recently discovered in another quasar (PKS 0637-752, z = 0.654) at 1.6 keV in the quasar frame, is due to blueshifted OVII emission, the Doppler blueshifting factor in both quasars is similar (approximately 2.7 - 2.8).
MR head manufacturing sensitivity analysis using transmission line model

Transmission line based equations are developed to describe the operation of MR heads. An analytical solution for magnetic flux in MR films is derived for linear operation. This transmission line method is used to analyze the design center of shielded dual stripe, soft adjacent layer and barberpole MR heads. Error propagation analysis is used to analyze the manufacturing tolerance sensitivity of these various heads. Finally, a Monte Carlo simulation is used to investigate the expected distribution in performance of manufactured MR heads. >
Tests of perturbative QCD and jet physics

The author was selective, and organized this presentation by final state: jets, photons, weak bosons and heavy flavor.
The peaceful settlement of disputes among African states, 1963–1983: Some conceptual issues and practical trends

(1989). The peaceful settlement of disputes among African states, 1963–1983: Some conceptual issues and practical trends. Commonwealth Law Bulletin: Vol. 15, No. 4, pp. 1505-1523.
Turbulence and random processes in fluid mechanics

Fluid flow turbulence is a phenomenon of great importance in many fields of engineering and science. Turbulence and related areas have continued to be subjects of intensive research over the last century. In this second edition of their successful textbook Professors Landahl and Mollo-Christensen have taken the opportunity to include recent developments in the field of chaos and its applications to turbulent flow. This timely update continues the original theme of the book: presenting the fundamental concepts and basic methods of fluid flow turbulence which enable the reader to follow the literature and understand current research. The emphasis upon the dynamic processes that create and maintain turbulent flows gives this book an original approach. This book should be useful to graduate students and researchers in fluid dynamics and, in particular, turbulence and related fields.