cssi/SciSciGPT-SciSciNet huggingface dataset:
Novel succinct routes to Quinoxalines and 2-Benzimidazolylquinoxalines via the Ugi reaction.

Abstract This Letter reveals a unique, user-friendly, concise two-step, one-pot protocol for the synthesis of highly substituted quinoxalines. Conducting the Ugi reaction with appropriately functionalized classical Ugi reagents with subsequent acid treatment of the Ugi adduct affords collections of diversified quinoxalines in good to excellent yields. The methodology exploits what may be viewed as a ‘convertible carboxylic acid’, which in addition may be captured in an intramolecular sense to generate structurally complex 2-benzimidazolylquinoxalines in a mere two steps.
On Free Conformal and Vertex Algebras

Vertex algebras and conformal algebras have recently attracted a lot of attention due to their connections with physics and Moonshine representations of the Monster. See, for example, [6], [10], [15], [17], [19]. In this paper we describe bases of free conformal and free vertex algebras (as introduced in [6], see also [20]). All linear spaces are over a field k of characteristic 0. Throughout this paper Z+ will stand for the set of non-negative integers. In §1 and §2 we give a review of conformal and vertex algebra theory. All statements is these sections are either in [9], [15], [16], [17], [18], [20] or easily follow from results therein. In §3 we investigate free conformal and vertex algebras.
Unavoidable subhypergraphs: a-clusters

One of the central problems of extremal hypergraph theory is the description of unavoidable subhypergraphs, in other words, the Turan problem. Let a=(a"1,...,a"p) be a sequence of positive integers, k=a"1+...+a"p. An a-partition of a k-set F is a partition in the form F=A"1@?...@?A"p with |A"i|=a"i for 1=p and sufficiently large n, if F is a k-uniform family on n vertices with |F| exceeding the Erdos-Ko-Rado bound (n-1k-1), then F contains an a-cluster. The only extremal family consists of all the k-subsets containing a given element.
Scaling multiple-source entity resolution using statistically efficient transfer learning

We consider a serious, previously-unexplored challenge facing almost all approaches to scaling up entity resolution (ER) to multiple data sources: the prohibitive cost of labeling training data for supervised learning of similarity scores for each pair of sources. While there exists a rich literature describing almost all aspects of pairwise ER, this new challenge is arising now due to the unprecedented ability to acquire and store data from online sources, interest in features driven by ER such as enriched search verticals, and the uniqueness of noisy and missing data characteristics for each source. We show on real-world and synthetic data that for state-of-the-art techniques, the reality of heterogeneous sources means that the number of labeled training data must scale quadratically in the number of sources, just to maintain constant precision/recall. We address this challenge with a brand new transfer learning algorithm which requires far less training data (or equivalently, achieves superior accuracy with the same data) and is trained using fast convex optimization. The intuition behind our approach is to adaptively share structure learned about one scoring problem with all other scoring problems sharing a data source in common. We demonstrate that our theoretically-motivated approach improves upon existing techniques for multi-source ER.
REVISED RATES OF STELLAR DISRUPTION IN GALACTIC NUCLEI

We compute rates of tidal disruption of stars by supermassive black holes in galactic nuclei, using downwardly revised black hole masses from the MBH-σ relation. In galaxies with steep nuclear density profiles, which dominate the overall event rate, the disruption frequency varies inversely with assumed black hole mass. We compute a total rate for nondwarf galaxies of ~10-5 yr-1 Mpc-3, about a factor of 10 higher than in earlier studies. Disruption rates are predicted to be highest in nucleated dwarf galaxies, assuming that such galaxies contain black holes. Monitoring of a rich galaxy cluster for a few years could rule out the existence of intermediate-mass black holes in dwarf galaxies.
Graph process specifications for hybrid networked systems

Many large-scale multi-agent missions consist of a sequence of subtasks, each of which can be accomplished separately by having agents execute appropriate decentralized controllers. However, many decentralized controllers have network topological prerequisites that must be satisfied in order to achieve the desired effect on a system. Therefore, one cannot always hope to accomplish the original mission by having agents naively switch through executing the controllers for each subtask. This paper extends the Graph Process Specification (GPS) framework, which was presented in previous work as a way to script decentralized control sequences for agents, while ensuring that network topological requirements are satisfied when each controller in the sequence is executed. Atoms, the fundamental building blocks in GPS, each explicitly state a network topological transition. Moreover, they specify the means to make that transition occur by providing a multi-agent controller, as well as a way to locally detect the transition. Scripting a control sequence in GPS therefore reduces to selecting a sequence of atoms from a library to satisfy network topological requirements, and specifying interrupt conditions for switching. As an example of how to construct an atom library, the optimal decentralization algorithm is used to generate atoms for agents to track desired multi-agent motions with when the network topology is static. The paper concludes with a simulation of agents performing a drumline-inspired dance using decentralized controllers generated by optimal decentralization and scripted using GPS.
9,10-Dimethylenetricyclo[5.3.0.02,8]deca-3,5-diene

Abstract The title compound (3), a molecule whose central cyclobutane ring is 1,3-bonded in hybrid fashion to two butadiene units, has been prepared and its thermal stability assessed relative to 1 and 2.
A Spurious Correlation Between Hospital Mortality and Complication Rates. The Importance of Severity Adjustment

Objectives. When two outcome measures, such as mortality and complication rates, are intended to measure the same underlying quantity (in this case hospital quality of care), one expects they will be highly correlated. In addition, as data quality improves, one expects the correlation will increase. The authors show that these expectations are, in a significant way, mistaken. Methods. The authors study two outcomes (hospital mortality and complication rates after surgery) using three predictive models that vary in adjustment for severity of illness. Results. Two hospital rankings, based on each of the two outcomes, are well correlated when not adjusted for severity. However, as clinical data are added to the models, the correlation tends to disappear. The authors explain this based on assumptions regarding the relative size of the partial correlations between mortality, complication rate, and severity covariates. Conclusions. Before claims of construct validity can be made, investigators must show that correlations between outcomes purporting to measure quality of care are sustained after adequate correction for severity. Most importantly, it should be recognized that inadequately controlled confounding variables may lead to a spurious high correlation between an accepted and a new outcome measure, and a false sense of adequate construct validity.
Reversibility and irreversibility in the packing of vibrated granular material

Abstract We report on the settling of loosely packed, cohesionless granular material under mechanical vibrations. Monodisperse spherical beads were confined to a long vertical cylinder that was driven by an electromagnetic vibration exciter. Under vibrations the bead packing evolves from an initial, low-density configuration towards higher density. Ramping the vibration intensity repeatedly up and back down again reveals the existence of both an irreversible and a reversible branch in the response. The reversible branch represents a steady state in which the packing density depends monotinically on the vibration intensity. We have investigated the bead size, depth, and ramp rate dependence of the compaction process. Our results indicate how the occupied volume fraction can be optimized by slowly reducing the vibration intensity along the reversible branch.
Iridium-catalyzed Arene ortho-Silylation by Formal Hydroxyl-directed C-H Activation

A strategy for the ortho-silylation of aryl ketone, benzaldehyde, and benzyl alcohol derivatives has been developed in which a hydroxyl group formally serves as the directing element for Ir-catalyzed arene C−H bond activation. One-pot generation of a (hydrido)silyl ether from the carbonyl compound or alcohol is followed by dehydrogenative cyclization at 80−100 °C in the presence of norbornene as a hydrogen acceptor and the combination of 1 mol % [Ir(cod)OMe]2 and 1,10-phenanthroline as a catalyst to form benzoxasiloles. The synthetic utility of the benzoxasilole products is demonstrated by conversion to phenol or biaryl derivatives by Tamao−Fleming oxidation or Hiyama cross-coupling. Both of these transformations of the C−H silylation products exploit the Si−O bond in the system and proceed by activation of the silyl moiety with hydroxide, rather than fluoride.
Diketones from ozonolysis of fused 3-phospholene oxides: Cyclizations to 3-phosphorinone and to 1,4-dihydro-1,4-azaphosphinine derivatives†

1-R-3-Methyl-2,4,5,6,7,7a-hexahydro-1(H)-phosphindole 1-oxide and 1-R-3-methyl-6-methoxy-2,8,9,9a-tetrahydro-1(H)-benzo[e]phosphindole 1-oxide (R = Me or Ph) were prepared and ozonized at −78°C to give diketones in good yield. The intramolecular aldol condensation was performed on certain of these ketones to give multicyclic 3-phosphorinone derivatives. In some cases, double-bond rearrangement into the ring-fusion position was encountered. The 1-phenyl derivative in the benzophosphindole series could not be cyclized due to ready displacement of the P fragment from the tetralone system. The diketones reacted with ammonium acetate to give multicyclic derivatives of the 1,4-dihydro-1,4-azaphosphinine ring system. 1,2,3,4,5,6,7,8-Octahydro-3-oxo-1-phenylphosphinoline 1-oxide was used to demonstrate the value of the bicyclic 3-phosphorinones as precursors of 1-phosphadecalone derivatives. The carbonyl group was protected as the ethylene ketal and the double bond (as well as the benzene ring) was hydrogenated with ease. Hydrolysis gave the 1-phospha-3-decalone derivative. Reduction of the same 3-phosphorinone with NaBH4 gave a mixture of diastereomeric alcohols.
An experiment in mechanical searching of research literature with RAMAC

A literature searching system which can store for retrieval information on 25,000 documents has been developed at the International Business Machines Corporation (IBM) Research Laboratory, San Jose, California. This was accomplished on an IBM 305 Random Access Memory Accounting Computer (RAMAC) in a research project aimed at gaining experience in information retrieval while providing functional aid to the technical library at the laboratory.
The CVD of Nanodiamond Materials

The growth and characteristics of nanocrystalline diamond thin films with thicknesses from 20 nm to less than 5 µm are reviewed. These materials contain between 95% and >99.9% diamond crystallites, the balance being made up from other forms of carbon. Within this class of materials there is a continuous range of composition, characteristics, and properties which depend on the nucleation and growth conditions. It is convenient to classify these films as either ultra-nanocrystalline-diamond (UNCD) or nanocrystalline-diamond (NCD) based on their microstructure, properties, and growth environment. In general, UNCD materials are composed of small particles of diamond ca. 2–5 nm in size with sp2-carbon bonding between the particles. UNCD is usually grown in argon-rich, hydrogen-poor CVD environments, and may contain up to 95–98% sp3-bonded carbon. NCD materials start with high density nucleation, initiating nanometer-sized diamond domains which grow in a columnar manner with the grain size coarsening with thickness. NCD is generally grown in carbon-lean and hydrogen-rich environments. NCD and UNCD exhibit an interesting range of physical properties which find use in X-ray windows and lithography, micro- and nanomechanical and optical resonators, tribological shaft seals and atomic force microscopy (AFM) probes, electron field emitters, platforms for chemical and DNA sensing, and many other applications.
On the Reionization of the Universe

I present first principle model calculations for the reionization of the Universe, that provide simple diagnostics to identify the reionization sources. Within this frame, I also discuss the results derived from the Hubble Ultra-Deep Field observations, and the possible need for future observations with JWST to provide the final answer.
The Galaxy Pairwise Velocity Dispersion as a Function of Local Density

The standard method of measuring the galaxy pairwise velocity dispersion on small scales via the anisotropy in the two-point correlation function in redshift space suffers from the fact that it is a pair-weighted statistic, and thus is heavily weighted by the densest regions in a way that is difficult to calibrate. We propose a new statistic, the redshift difference of close projected pairs of galaxies as a function of local density, which is designed to measure the small-scale velocity dispersion as an explicit function of density. Computing this statistic for a volume-limited subsample of the Optical Redshift Survey, we find that the small-scale velocity dispersion rises from 220 km s-1 in the lowest density bins to 760 km s-1 at high density. We calculate this statistic for a series of mock catalogs drawn from a hydrodynamic simulation of an Ωh = 0.5 cold dark matter universe (standard CDM) and find that the observed velocity distribution lies 1 σ below the simulations in each of eight density bins; this measurement formally rules out this model at the 7.4 σ level and quantifies the well-known problem that this model produces too high a velocity dispersion. This comparison is insensitive to the normalization of the power spectrum, although it is quite sensitive to the density and velocity bias of galaxies relative to dark matter on small scales.
Improving Authentication Performance of Distributed SIP Proxies

The performance of SIP proxies is critical for the robust operation of many applications. However, the use of even light-weight authentication schemes can significantly degrade throughput in these systems. In particular, systems in which multiple proxies share a remote authentication database can experience reduced performance due to latency. In this paper, we investigate how the application of parallel execution and batching can be used to maximize throughput while carefully balancing demands for bandwidth and call failure rates. Through the use of a modified version of OpenSER, a high-performance SIP proxy, we demonstrate that the traditional recommendation of simply launching a large number of parallel processes not only incurs substantial overhead and increases dropped calls, but can actually decrease call throughput. An alternative technique that we implement, request batching, similarly fails to achieve high proxy throughput. Through a carefully selected mix of batching and parallelization, we reduce the bandwidth required to maximize authenticated signaling throughput by the proxy by more than 75 percent. This mix also keeps the call loss rates below 1 percent at peak performance. In addition, we demonstrate that the delay introduced by batching is acceptable for VoIP applications. As a result, our technique significantly reduce the cost and increase the throughput of authentication for large-scale networks supporting SIP applications.
de Novo Purine Synthesis is Increased in the Fibroblasts of Purine Autism Patients

A number of cases have been reported in the medical literature over the past thirty years describing patients with autistic symptoms combined with prominent hyperurico-suria.1–3 A number of these patients exhibited other neurological symptoms as well, including seizures, ataxia, and spasticity. In some of these reports, the autistic and/or neurological symptoms seem to have been ameliorated by antihyperuricosuric metabolic therapy. Studies undertaken to determine the percentage of the autistic population which overproduces uric acid arrived at a figure of 22–29%, as compared to < 3% of the normal population.3,4
Student Ratings of Instruction and Their Relationship to Student Learning

Student ratings of instruction were correlated with examination performance in 72 sections of seven courses. In two of the courses, students had been randomly assigned to sections. The pattern of correlations across the courses indicated that the global ratings of teacher effectiveness and of the value of the course to students were most highly related to mean exam performance (12 out of 24 product-moment and partial correlations were 58 or above). Ratings of course objectives and organizations, and of the quality of lectures were also fairly well correlated with achievement. Ratings of other aspects of instruction, such as the teacher-student relationship or the difficulty/workload of the course, were not highly related to achievement scores.
Ultra-shallow p+-junction formation in silicon by excimer laser doping: a heat and mass transfer perspective

Heat and mass transfer at the nanosecond time scale and the nanometer length scale in pulsed laser fabrication of ultra-shallow p+-junctions is studied in this work. A new technique is developed to fabricate the ultra-shallow p÷-junctions with pulsed laser doping of crystalline silicon with a solid spin-on- glass (SOG) dopant, through the nanosecond pulsed laser heating, melting, and boron mass diffusion in the 100 nm thin silicon layer close to the surface. High boron concentration of 1020 atoms cc -1 and the 'box-like' junction profile are achieved. The key mechanism determining the 'box-like' junction shape is found to be the melt-solid interface limited diffusion. The ultra-shallow p+-junctions with the depth from 30 to 400 nm are successfully made by the excimer laser. The optimal laser fluence condition for SOG doping is found about 0.6-0.8 J cm -2 by studying the ultra-shallow p+-junction boron profiles measured by the secondary ion mass spectroscopy (SIMS) vs the laser fluence and the pulse number. The one- dimensional numerical analysis agrees reasonably with the experiment, within the available physical picture. Possible mechanisms such as boron diffusivity dependence on the dopant concentration in the molten silicon are proposed. Copyright © 1996 Elsevier Science Ltd.
STRUCTURE-ENHANCED YIELD SHEAR STRESS IN ELECTRORHEOLOGICAL FLUIDS

A new technology, compression-assisted aggregation, is developed to enhance the strength of electrorheological (ER) fluids. The yield shear stress of ER fluids depends on the fluid microstructure. The unassisted electric-field induced ER structure mainly consists of single chains, whose weak points are at their ends. This new technology produces a structure consisting of robust thick columns with strong ends. As the weak points of the original ER structure are greatly enforced, the new structure makes ER fluids super-strong: At a moderate electric field and moderate pressure the yield shear stress of ER fluids at 35% volume fraction exceeds 100 kPa, well above any requirement for major industrial applications.
Room temperature zinc chloride-catalyzed cycloisomerization of Alk-3-yn-1-ones: synthesis of substituted furans.

5-Endo-dig cycloisomerization of 1,4-di- and 1,2,4-trisubstituted but-3-yn-1-ones in the presence of a catalytic amount of zinc chloride (10 mol %) in dichloromethane at room temperature (22 °C) provides 2,5-di- and 2,3,5-trisubstituted furans in high yields (85−97%).
Spontaneously broken supersymmetry and Poincaré invariance

Abstract It is argued that the spontaneous breakdown of global supersymmetry is consistent with unbroken Poincare invariance if and only if the supersymmetry algebra “ A =0” is understood to mean the invariance of the dynamical variables o under the transformations generated by the algebra, i.e. [ A ,o]=0 rather than as an operator equation. It is further argued that this “weakining” of the algebra does not alter any of the conclusions about supersymmetry quantum field theories that have been obtained using the original (stronger) form of the algebra.
Blind Consent? A Social Psychological Investigation of Non-Readership of Click-Through Agreements

Across two studies we aimed to measure empirically the extent of non-readership of click-through agreements (CTAs), identify the dominant beliefs about CTAs contributing to non-readership, and experimentally manipulate these beliefs to decrease automatic non-reading behavior and enhance contract efficiency. In our initial questionnaire study (Study 1), as predicted, the vast majority of participants reported not reading CTAs and the most prevalent beliefs about CTAs contributing to non-readership included: they are too long and time-consuming, they are all the same, they give one no choice but to agree, they are irrelevant, and vendors are generally reputable. Manipulating these beliefs on a simulated music website (Study 2) revealed an increase in readership. In addition, CTA comprehension and CTA rejection rates were both increased significantly by manipulating the length of the CTA. These results demonstrate support for the influence of widely held beliefs about CTAs on contract readership, provide evidence against the common “limited cognition” perspective on non-readership, and suggest that presenting CTAs in a short, readable format can increase CTA readership and comprehension as well as shopping of CTA terms.
Chaos in the Kepler system

The long-term dynamical evolution of a Keplerian binary orbit due to the emission and absorption of gravitational radiation is investigated. This work extends our previous results on transient chaos in the planar case to the three-dimensional Kepler system. Specifically, we consider the nonlinear evolution of the relative orbit due to gravitational radiation damping as well as external gravitational radiation that is obliquely incident on the initial orbital plane. The variation of orbital inclination, especially during resonance capture, turns out to be very sensitive to the initial conditions. Moreover, we discuss the novel phenomenon of chaotic transition.
Numerical simulation of the solar granulation

The solar granulation has been simulated by numerical solution of the multidimensional, time-dependent, nonlinear Navier-Stokes equations applied to the solar atmosphere. Granules may be explained as buoyantly rising bubbles created at the level where T = 8000 K, and which have collapsed into vortex rings. The calculation is in quantitative agreement with observations and has a number of implications for solar physics and convection theory.
The molybdenum-mediated tandem Pauson-Khand reaction. High yield entry into (5.5.5.5)tetracyclic systems

Abstract The [5.5.5.5]tetracyclic ring systems 1 and 2 were synthesized in high yield via a molybdenum carbonyl-mediated Pauson–Khand (type) reaction which is much easier to execute than the previous cobalt carbonyl mediated process.
Component selection and smoothing in multivariate nonparametric regression

We propose a new method for model selection and model fitting in multivariate nonparametric regression models, in the framework of smoothing spline ANOVA. The "COSSO" is a method of regularization with the penalty functional being the sum of component norms, instead of the squared norm employed in the traditional smoothing spline method. The COSSO provides a unified framework for several recent proposals for model selection in linear models and smoothing spline ANOVA models. Theoretical properties, such as the existence and the rate of convergence of the COSSO estimator, are studied. In the special case of a tensor product design with periodic functions, a detailed analysis reveals that the COSSO does model selection by applying a novel soft thresholding type operation to the function components. We give an equivalent formulation of the COSSO estimator which leads naturally to an iterative algorithm. We compare the COSSO with MARS, a popular method that builds functional ANOVA models, in simulations and real examples. The COSSO method can be extended to classification problems and we compare its performance with those of a number of machine learning algorithms on real datasets. The COSSO gives very competitive performance in these studies.
Leveling the informational Playing Field

This study uses experimental data to compare the information generated by professional and nonprofessional investors when both groups receive access to the same financial disclosures. We also manipulate the disclosure level for both subject groups. Using the method developed by Barron, Kim, Lim and Stevens (1998), we then analyze the information contained in stock price forecasts that were made by the experimental subjects. Professionals on average inferred more information than nonprofessionals. The higher level of disclosure did not affect the information possessed by the professional investors. However, we find that a higher level of disclosure is associated with more private information being produced (or inferred) by nonprofessional investors. As a result, these subjects realized a significant improvement in the accuracy of their mean forecasts relative to their individual forecasts. This finding suggests that the enhanced capacity of firms to widely disclose information to all market participants via the Internet, together with the SEC's new “Fair Disclosure (FD)” regulation, has the potential to produce a significant increase in privately inferred information for on‐line nonprofessionals, potentially resulting in the aggregation of more diverse information into share prices.
Corestrictions of algebras and splitting fields

Given a field F, an etale extension L/F and an Azumaya algebra A/L, one knows that there are extensions E/F such that A ⊗ F E is a split algebra over L ⊗ F E. In this paper we bound the degree of a minimal splitting field of this type from above and show that our bound is sharp in certain situations, even in the case where L/F is a split extension. This gives in particular a number of generalizations of the classical fact that when the tensor product of two quaternion algebras is not a division algebra, the two quaternion algebras must share a common quadratic splitting field. In another direction, our constructions combined with results of Karpenko (1995) also show that for any odd prime number p, the generic algebra of index p n and exponent p cannot be expressed nontrivially as the corestriction of an algebra over any extension field if n < p 2 .
Module categories, weak Hopf algebras and modular invariants

We develop a theory of module categories over monoidal categories (this is a straightforward categorization of modules over rings). As applications we show that any semisimple monoidal category with finitely many simple objects is equivalent to the category of representations of a weak Hopf algebra (theorem of T. Hayashi) and we classify module categories over the fusion category of sl(2) at a positive integer level where we meet once again the ADE classification pattern.
Cash Balance Pension Plan Conversions and the New Economy

Many firms that sponsor traditional defined benefit pensions have converted these plans to cash balance plans in the last en years. Cash balance plans in the last ten years combine features of defined benefit and defined contribution plans, and yet their introduction has proven considerably more controversial than has the increasing popularity of defined contribution plans. The goal of this study is to estimate a hierarchy of the influences on the decision of a firm to convert its traditional defined benefit pension plan to a cash balance plan. Our results indicate that cash balance conversions have been undertaken in competitive industries with tight labor markets and thus can be viewed at least in part as a response to better compensate a more mobile labor force. Indeed, many firms appear to increase their pension liabilities through such conversions.
Preparation, chemical reactions, and some physical properties of neptunium pentafluoride

Abstract The preparation of NpF 5 by reacting a solution containing NpF 6 − with the Lewis acid BF 3 in anhydrous HF is reported. The purity of NpF 5 was established by its Mossbauer spectrum, which showed only the presence of Np 5+ . Thermal decomposition and some chemical reactions of NpF 5 are described. Debye-Scherrer powder data from NpF 5 appear similar to those obtained from α-UF 5 , indexing as tetragonal with cell constants a = 6.5358(18) A and c = 4.4562(14) A . Photochemical irradiation of NpF 6 produced an amorphous material believed, but not confirmed, to be NpF 5 .
Investigating omitted variable bias in regression parameter estimation: A genetic algorithm approach

Bias in regression estimates resulting from the omission of a correlated relevant variable is a well-known phenomenon. In this study, we apply a genetic algorithm to estimate the missing variable and, using that estimated variable, demonstrate that significant bias in regression estimates can be substantially corrected with relatively high confidence in effective models. Our interest is restricted to the case of a missing binary indicator variable and the analytical properties of bias and MSE dominance of the resulting dependent error generated vector process. These findings are compared to prior results for the independent error proxy process. Simulations are run for medium sample sizes and the method is shown to produce substantial reduction in estimation bias and often renders useful estimates of the missing vector. Limited simulations for the continuous variable case are reported and indicate some potential for the method and future research.
Imaging and Radiologic Management of Upper Urinary Tract Infections

There are many manifestations of infectious disease within the upper urinary tract—from acute to chronic, from those requiring no radiologic imaging to those requiring the expertise of an interventional radiologist, from those treated medically to those processes where surgical intervention is necessary. This overview of upper urinary tract infections (UTI) emphasizes imaging and radiologic intervention in a variety of complex and uncommon processes.
Circuit size relative to pseudorandom oracles

Circuit-size complexity is compared with deterministic and nondeterministic time complexity in the presence of pseudorandom oracles. The following separations are shown to hold relative to every pspace-random oracle A, and relative to almost every oracle A∈ESPACE. (i) NPA is not contained in SIZEA(2αn) for any real α < 13. (ii) EA is not contained in SIZEA(2nn). Thus, neither NPA nor EA is contained in PA/Poly. In fact, these separations are shown to hold for almost every n. Since a randomly selected oracle is pspace-random with probability one, (i) and (ii) immediately imply the corresponding random oracle separations, thus improving a result of Bennett and Gill (1981) and answering open questions of Wilson (1985).
Radiation-induced amorphization of crystalline ice

Abstract We study radiation-induced amorphization of crystalline ice, analyzing the results of three decades of experiments with a variety of projectiles, irradiation energy, and ice temperature, finding a similar trend of increasing resistance of amorphization with temperature and inconsistencies in results from different laboratories. We discuss the temperature dependence of amorphization in terms of the ‘thermal spike’ model. We then discuss the common use of the 1.65 μm infrared absorption band of water as a measure of degree of crystallinity, an increasingly common procedure to analyze remote sensing data of astronomical icy bodies. The discussion is based on new, high quality near-infrared reflectance absorption spectra measured between 1.4 and 2.2 μm for amorphous and crystalline ices irradiated with 225 keV protons at 80 K. We found that, after irradiation with 10 15 protons cm −2 , crystalline ice films thinner than the ion range become fully amorphous, and that the infrared absorption spectra show no significant changes upon further irradiation. The complete amorphization suggests that crystalline ice observed in the outer Solar System, including trans-neptunian objects, may results from heat from internal sources or from the impact of icy meteorites or comets.
Effect of vanadium on oxygen diffusivity in niobium

Abstract The effect on the diffusivity of oxygen of vanadium additions to niobium was investigated by a diffusion couple technique. The addition of vanadium to niobium results in an increase of the activation energy for oxygen diffusion from 107 kJ mol −1 for oxygen in niobium to 176 ± 9 kJ mol −1 for the Nb-0.5at.%V alloy and to 194 ± 9 kJ mol −1 for the Nb-10at.%V alloy. This increase in the activation energy is attributed to the trapping of oxygen by vanadium atoms. Applying Kirchheim's trapping model and the results of internal friction measurements, trapping energies of about −64 and −49 kJ mol −1 were obtained for the Nb-0.5at.%V and the Nb-10at.%V alloys respectively.
α-(Benzotriazolyl)methyl phenyl thioethers: Convenient reagents for α-phenylthioalkylation of silylated nucleophiles

Abstract Stable, crystalline α-(benzotriazolyl)methyl phenyl thioethers ( 1 ), easily prepared from carbonyl compounds, thiophenol and benzotriazole, are convenient reagents for the phenylthiomethylation of trimethylsilyl cyanide, trimethylallylsilane, and trimethylsilyl enol ethers to afford the corresponding substituted thioethers and β-phenylthioalkylketones ( 3 ) in good yields.
ORDERLY SPECTRA FROM RANDOM INTERACTIONS

We investigate the low-lying spectra of many-body systems with random two-body interactions, specifying that the ensemble be invariant under particle-hole conjugation. Surprisingly we find patterns reminiscent of more orderly interactions, such as a predominance of J=0 ground states separated by a gap from the excited states, and evidence of phonon vibrations in the low-lying spectra. {copyright} {ital 1998} {ital The American Physical Society}
A Knowledge-Based Approach to Design

A framework is presented for constructing knowledge-based aids for design problems. In particular, we describe the organization of an interactive knowledge-based consultant for VLSI design (called VEXED?an acronym for VLSI expert editor), and a prototype implementation of VEXED. The paper focuses on the principles underlying the design of VEXED, and on several lessons and research issues that have arisen from implementing and experimenting with this prototype.
A multigram chemical synthesis of the γ-secretase inhibitor LY411575 and its diastereoisomers

An improved chemical synthesis of N-2((2S)-2-(3,5-difluorophenyl)-2-hydroxyethanoyl)-N1-((7S)-5-methyl-6-oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl)-l-alaninamide (LY411,575, 9a), a known gamma-secretase inhibitor, is described. The key synthetic steps, which used no chiral chromatography in the entire sequence, involved (1) improved microwave-assisted synthesis of a seven-membered lactam (+/-)-(5,7-dihydro-6H-dibenz-[b,d]azepin-6-one 2, and (2) convenient isolation of pure LY411575 from a mixture of four diastereomers by simple flash silica gel chromatography. Starting from the resolved aminolactams 5a and 5b, all four diastereomers were produced in enantiomerically pure form.
On Approximation of Continuous Functions by Entire Functions on Subsets of the Real Line

We generalize the classical Bernstein theorem concerning the constructive description of classes of functions uniformly continuous on the real line. Approximation of continuous bounded functions by entire functions of exponential type on unbounded closed proper subsets of the real line is studied.
The relationship between the distribution of common carp and their environmental DNA in a small lake.

Although environmental DNA (eDNA) has been used to infer the presence of rare aquatic species, many facets of this technique remain unresolved. In particular, the relationship between eDNA and fish distribution is not known. We examined the relationship between the distribution of fish and their eDNA (detection rate and concentration) in a lake. A quantitative PCR (qPCR) assay for a region within the cytochrome b gene of the common carp (Cyprinus carpio or ‘carp’), an ubiquitous invasive fish, was developed and used to measure eDNA in Lake Staring (MN, USA), in which both the density of carp and their distribution have been closely monitored for several years. Surface water, sub-surface water, and sediment were sampled from 22 locations in the lake, including areas frequently used by carp. In water, areas of high carp use had a higher rate of detection and concentration of eDNA, but there was no effect of fish use on sediment eDNA. The detection rate and concentration of eDNA in surface and sub-surface water were not significantly different (p≥0.5), indicating that eDNA did not accumulate in surface water. The detection rate followed the trend: high-use water > low-use water > sediment. The concentration of eDNA in sediment samples that were above the limit of detection were several orders of magnitude greater than water on a per mass basis, but a poor limit of detection led to low detection rates. The patchy distribution of eDNA in the water of our study lake suggests that the mechanisms that remove eDNA from the water column, such as decay and sedimentation, are rapid. Taken together, these results indicate that effective eDNA sampling methods should be informed by fish distribution, as eDNA concentration was shown to vary dramatically between samples taken less than 100 m apart.
Jets and Partons

Jet production in high energy hadron-hadron collisions can serve as a probe for new physics. I review recent data from CDF and DO on the high ET jet cross section. Reporting on recent work of the CTEQ collaboration, I argue that the apparent excess seen in the CDF data may be due to the gluon distribution function used in the theoretical calculation being too large at large x. I discuss data on the dijet angular distribution, which shows no sign of a new physics signal.
Radiation therapy of malignant melanomas: an evaluation of clinically used fractionation schemes

To assess the importance of radiation dose fraction size in the treatment of malignant melanomas, the records of 48 patients (83 sites) treated at Tufts-New England Medical Center from 1971 to 1979 have been retrospectively reviewed. During this period, the dose fractionation schemes evolved from standard fraction size to large-dose techniques. Radiation fraction size was observed to be the major factor in the clinical response of melanoma. Fractions of 600-800 rad resulted in the best overall response (80%). The rapid fractionation scheme of 800-400-400 rad on successive days resulted in intermediate response (58%) and may be useful for the palliative treatment of selected patients.
Axisymmetric Breakdown of a Q-Vortex in a Pipe

Necessary and sufficient conditions for the axisymmetric breakdown of a Q-vortex in a pipe are presented. These unique calculations are guided by a recent rigorous theoretical approach on this subject (Wang, S., and Rusak, Z.). The fundamental characteristics that lead to vortex instability and breakdown in high-Reynolds-number swirling flows are computed from the solutions of a single, nonlinear, reduced-order, ordinary differential equation, representing a columnar flow problem. The breakdown criteria for the Q-vortex for various core radii and jet/wake axial flow profiles are described. Results show good agreement with available experimental data of axisymmetric breakdown in swirling flows in a pipe. The correlation between the present results and other criteria for vortex breakdown is also discussed
Stress transfer modeling in viscoelastic polymer matrix composites

Abstract A viscoelastic analysis of a single fiber unidirectional composite model is carried out to investigate the time-dependent stress transfer between an elastic fiber and a viscoelastic matrix for loading in the axial direction. The stress state in the composite is solved at incremental time intervals to obtain the stabilized solution, and the time required to reach a stable state. The results obtained from a linear viscoelastic analysis are compared with the corresponding result obtained by using a non-linear “clock” model for the viscoelastic matrix. It is found that the non-linear analysis predicts a significantly lower stabilization time to reach the same final stress state.
Energy management in mobile devices with the cinder operating system

We argue that controlling energy allocation is an increasingly useful and important feature for operating systems, especially on mobile devices. We present two new low-level abstractions in the Cinder operating system, reserves and taps, which store and distribute energy for application use. We identify three key properties of control -- isolation, delegation, and subdivision -- and show how using these abstractions can achieve them. We also show how the architecture of the HiStar information-flow control kernel lends itself well to energy control. We prototype and evaluate Cinder on a popular smartphone, the Android G1.
Development of a High-Speed Three-Dimensional Flow Visualization Technique

A high-speed three-dimensional flow visualization system has been developed and is described. The technique is based on the high-speed scanning and subsequent imaging of a two-dimensional laser sheet through the flowfield. A three-dimensional image is then reconstructed from the stack of two-dimensional slices. The technique achieves high speeds using a home-built megahertz-rate pulse-burst laser system, a galvanometric scanning mirror, and a high-speed intensified charge-coupled-device camera capable of 500,000 frames per second. These components allow for the acquisition of three-dimensional image data with a resolution of 220 x 220 x 68 volumetric elements (voxels) in 136 μs. The speed of the technique is limited by the available camera speed and can be increased substantially using a higher-speed camera. The technique is demonstrated through three-dimensional visualization a turbulent round jet (Re = 6700) seeded with small water droplets for light scattering. Three-dimensional flow visualization images display numerous three-dimensional features of the jet, including ring vortices, azimuthal modes and counterrotating streamwise vortex pairs. Future work will focus on the development of a high-speed three-dimensional laser-induced fluorescence technique.
Intramolecular radical cyclization reactions. An approach to the indole alkaloids

Abstract The intramolecular radical cyclization reaction of N-allyl substituted derivatives of o-bromoacetanilide provides a short and effective route to a variety of dihydroindole systems.
Macroscopic parity violation and supernova asymmetries

Abstract Core collapse supernovae are dominated by weakly interacting neutrinos. This provides a unique opportunity for macroscopic parity violation. We speculate that parity violation in a strong magnetic field can lead to an asymmetry in the explosion and a recoil of the newly formed neutron star. We estimate the size of this asymmetry from neutrino polarized-neutron elastic scattering, polarized electron capture and neutrino-nucleus elastic scattering in a (partially) polarized electron gas.
Turbine Efficiency for Unsteady, Periodic Flows

The definition of turbine efficiency for a machine subjected to unsteady periodic inflows is studied. Since mass and energy are conserved quantities over a period, there is no ambiguity in calculating the actual work output of the turbine over a period. The main difficulty lies in calculating the isentropic work output of an ideal turbine operating under the “same” conditions. Two definitions of ideal work output are presented. In the first, the ideal turbine is assumed to operate under the same time traces of inlet and exit total pressures as the actual turbine. The expression for the efficiency that results involves no averages of total pressure. In the second approach, the ideal turbine is assumed to operate under the same average conditions as the actual turbine. Total pressure averages that preserve the isentropic work output are derived and used to calculate an efficiency of the turbine. The two expressions are calculated explicitly for the case of a turbine blade row downstream of a pulse detonation tube. It is found that the definition of efficiency using averages is approximately 10 points lower than the first definition.
Purity of Aluminum Hydroxide Derived from Triethylaluminum

Aluminum hydroxide obtained by hydrolysis of triethylaluminum is free of uranium and thorium at detection limits of 1 to 9 parts per billion (ppb). Other impurities commonly associated with aluminum oxides are present at low levels (Fe, ∼ 1 ppm; Si, 3 to 6 ppm). When the organoaluminum is intentionally contaminated with an iron salt, purity is restored by a simple distillation.
Shock Wave/Turbulent Boundary-Layer Interactions in Rectangular Channels

Interaction regions created by the impingement of full span, externally generated, shock waves on a nozzle wall boundary layer were investigated. Incident shock strength was varied to produce unseparated, incipient, and fully separated flow fields. Significant departures from two-dimensionality were observed over the entire range of shock strengths tested and were identified with sidewall and corner boundary layer effects. However, comparisons of present centerline results with published two-dimensional data, obtained under similar test conditions and geometrical constraints, showed excellent agreement (e.g., incipient separation pressure levels, wall pressure distributions, free-interaction, and scale of the interaction region). This raises some question concerning the degree of two-dimensionality achieved in these previous investigations.
Ridges and scarps in the equatorial belt of Mars

The morphology and distribution of ridges and scarps on Mars in the ± 30° latitude belt were investigated. Two distinct types of ridges were recognized. The first is long and linear, resembling mare ridges on the Moon; it occurs mostly in plains areas. The other is composed of short, anastomosing segments and occurs mostly in ancient cratered terrain and intervening plateaus. Where ridges are eroded, landscape configurations suggest that they are located along regional structures. The age of ridges is uncertain, but some are as young as the latest documented volcanic activity on Mars. The origins of ridges are probably diverse-they may result from wrinkling due to compression or from buckling due to settling over subsurface structures. The similar morphologic expressions of ridge types of various origins may be related to a similar deformation mechanism caused by two main factors: (1) most ridges are developed in thick layers of competent material and (2) ridges formed under stresses near a free surface.
Localization for discrete one-dimensional random word models☆

We consider Schrodinger operators in l2(Z) whose potentials are obtained by randomly concatenating words from an underlying set W according to some probability measure ν on W. Our assumptions allow us to consider models with local correlations, such as the random dimer model or, more generally, random polymer models. We prove spectral localization and, away from a finite set of exceptional energies, dynamical localization for such models. These results are obtained by employing scattering theoretic methods together with Furstenberg's theorem to verify the necessary input to perform a multiscale analysis.