cssi/SciSciGPT-SciSciNet huggingface dataset:
Wilford Woodruff and the Changing Nature of Mormon Religious Experience

Virtually all would agree that the attraction and growth of Mormonism has been unusual. From a small group of communicants and six members in 1830, it had become the twenty-first largest denomination of 143 in the United States by 1890 and the twelfth largest by 1906. Of the principal religious groups founded in the United States, only the Disciples of Christ (the Christian Church) was larger. In the nineteenth century, then, it had left such other indigenous churches as the Seventh Day Adventists, the Spiritualists, the Christian Scientists, and the Shakers far in the rear.3 There are various ways in which the problem of Mormonism's attraction and meaning can be tackled. The historian could investigate the lives, experiences, and beliefs of a broad range of people who joined the movement. He could attempt a statistical study of the backgrounds of the members of the church and investigate
Localized Permeabilization of E. Coli Membranes by the Antimicrobial Peptide Cecropin A

Fluorescence microscopy enables detailed observation of the effects of the antimicrobial peptide Cecropin A on the outer membrane (OM) and cytoplasmic membrane (CM) of single E. coli cells with subsecond time resolution. Fluorescence from periplasmic GFP decays and cell growth halts when the OM is permeabilized. Fluorescence from the DNA stain Sytox Green rises when the CM is permeabilized and the stain enters the cytoplasm. The initial membrane disruptions are localized and stable. Septating cells are attacked earlier than nonseptating cells, and curved membrane surfaces are attacked in preference to cylindrical surfaces. Below a threshold bulk Cecropin A concentration, permeabilization is not observed over 30 min. Above this threshold, we observe a lag time of several minutes between Cecropin A addition and OM permeabilization and 30 s between OM and CM permeabilization. The long lag times and the existence of a threshold concentration for permeabilization suggest a nucleation mechanism. However, the roughly linear dependence of mean lag time on bulk peptide concentration is not easily reconciled with a nucleation step involving simultaneous insertion of multiple peptides into the bilayer. Monte Carlo simulations suggest that within seconds, the OM permeability becomes comparable to that of a pore of 100 nm diameter or of numerous small pores distributed over a similarly large area. Studies with fluorescently labeled Cecropin A provide information about the kinetics of peptide binding to the OM, and subsequent entry of peptide molecules into the periplasm and cytoplasm. Single molecule imaging of fluorescently labeled Cecropin A allows measurement of trajectory lengths and diffusion constants of the peptide on the outer membrane surface.
The education of Walter Kohn and the creation of density functional theory

The theoretical solid-state physicist Walter Kohn was awarded one-half of the 1998 Nobel Prize in Chemistry for his mid-1960s creation of an approach to the many-particle problem in quantum mechanics called density functional theory (DFT). In its exact form, DFT establishes that the total charge density of any system of electrons and nuclei provides all the information needed for a complete description of that system. This was a breakthrough for the study of atoms, molecules, gases, liquids, and solids. Before DFT, it was thought that knowledge of the vastly more complicated many-electron wave function was essential for a complete description of such systems. Today, 50 years after its introduction, DFT (in one of its approximate forms) is the method of choice used by most scientists to calculate the physical properties of materials of all kinds. In this paper, I present a biographical essay of Kohn’s educational experiences and professional career up to and including the creation of DFT. My account begins with Kohn’s student years in Austria, England, and Canada during World War II and continues with his graduate and postgraduate training at Harvard University and Niels Bohr’s Institute for Theoretical Physics in Copenhagen. I then study the research choices he made during the first 10 years of his career (when he was a faculty member at the Carnegie Institute of Technology and a frequent visitor to the Bell Telephone Laboratories) in the context of the theoretical solid-state physics agenda of the late 1950s and early 1960s. Subsequent sections discuss his move to the University of California, San Diego, identify the research issue which led directly to DFT, and analyze the two foundational papers of the theory. The paper concludes with an explanation of how the chemists came to award “their” Nobel Prize to the physicist Kohn and a discussion of why he was unusually well suited to create the theory in the first place.
The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background. I. Limits and Detections

The Diffuse Infrared Background Experiment (DIRBE) on the Cosmic Background Explorer (COBE) spacecraft was designed primarily to conduct a systematic search for an isotropic cosmic infrared background (CIB) in 10 photometric bands from 1.25 to 240 μm. The results of that search are presented here. Conservative limits on the CIB are obtained from the minimum observed brightness in all-sky maps at each wavelength, with the faintest limits in the DIRBE spectral range being at 3.5 μm (νIν < 64 nW m-2 sr-1, 95% confidence level) and at 240 μm (νIν < 28 nW m-2 sr-1, 95% confidence level). The bright foregrounds from interplanetary dust scattering and emission, stars, and interstellar dust emission are the principal impediments to the DIRBE measurements of the CIB. These foregrounds have been modeled and removed from the sky maps. Assessment of the random and systematic uncertainties in the residuals and tests for isotropy show that only the 140 and 240 μm data provide candidate detections of the CIB. The residuals and their uncertainties provide CIB upper limits more restrictive than the dark sky limits at wavelengths from 1.25 to 100 μm. No plausible solar system or Galactic source of the observed 140 and 240 μm residuals can be identified, leading to the conclusion that the CIB has been detected at levels of νIν = 25 ± 7 and 14 ± 3 nW m-2 sr-1 at 140 and 240 μm, respectively. The integrated energy from 140 to 240 μm, 10.3 nW m-2 sr-1, is about twice the integrated optical light from the galaxies in the Hubble Deep Field, suggesting that star formation might have been heavily enshrouded by dust at high redshift. The detections and upper limits reported here provide new constraints on models of the history of energy-releasing processes and dust production since the decoupling of the cosmic microwave background from matter.
A Deep Chandra Observation of Kepler’s Supernova Remnant: A Type Ia Event with Circumstellar Interaction

We present initial results of a 750 ks Chandra observation of the remnant of Kepler's supernova of AD 1604. The strength and prominence of iron emission, together with the absence of O-rich ejecta, demonstrate that Kepler resulted from a thermonuclear supernova, even though evidence for circumstellar interaction is also strong. We have analyzed spectra of over 100 small regions, and find that they fall into three classes. (1) The vast majority show Fe L emission between 0.7 and 1 keV and Si and S Kα emission; we associate these with shocked ejecta. A few of these are found at or beyond the mean blast wave radius. (2) A very few regions show solar O/Fe abundance ratios; these we associate with shocked circumstellar medium (CSM). Otherwise O is scarce. (3) A few regions are dominated by continuum, probably synchrotron radiation. Finally, we find no central point source, with a limit ~100 times fainter than the central object in Cas A. The evidence that the blast wave is interacting with CSM may indicate a Ia explosion in a more massive progenitor.
Asymmetric reductions using the chiral boronic ester TarB–H: a practical and inexpensive procedure for synthesizing chiral alcohols

Abstract Chiral alcohols are prepared in high enantiomeric excesses using an inexpensive and easily synthesized tartaric acid derived boronic ester (TarB–H) with sodium borohydride. The phenylboronic acid could be recovered quantitatively using a simple extraction with sodium hydroxide and diethyl ether. The optimized TarB–H system was used to reduce aromatic and aliphatic ketones in an open flask to chiral alcohols with enantiomeric excesses up to 99%.
Efficient Hierarchical Graph-Based Segmentation of RGBD Videos

We present an efficient and scalable algorithm for segmenting 3D RGBD point clouds by combining depth, color, and temporal information using a multistage, hierarchical graph-based approach. Our algorithm processes a moving window over several point clouds to group similar regions over a graph, resulting in an initial over-segmentation. These regions are then merged to yield a dendrogram using agglomerative clustering via a minimum spanning tree algorithm. Bipartite graph matching at a given level of the hierarchical tree yields the final segmentation of the point clouds by maintaining region identities over arbitrarily long periods of time. We show that a multistage segmentation with depth then color yields better results than a linear combination of depth and color. Due to its incremental processing, our algorithm can process videos of any length and in a streaming pipeline. The algorithm's ability to produce robust, efficient segmentation is demonstrated with numerous experimental results on challenging sequences from our own as well as public RGBD data sets.
Collisional pumping of water masers by species of particles at different temperatures

It has been reported that the extreme power of astrophysical water masers can be obtained from purely collisional pumping in environments with two kinetic temepratures. It is found that this pumping vanishes when the latest rates are utilized for the collisional excitation of H2O molecules by neutrals. Energetic ions must also be present under the conditions that have been proposed for such 'two-temperature' pumping, but they have been ignored in the past due to lack of information about the relevant cross sections. Quantal, multichannel calculations in the impact parameter approximation are performed to provide a basis for estimating these rates for the collisional excitation of H2O molecules by ions. Including the effects of these ions does not restore the inversion, but rather reduces the pumping for H2O masers in the proposed 'two-temperature' environments.
Quantum Drinfeld Orbifold Algebras

Quantum Drinfeld orbifold algebras are the generalizations of Drinfeld orbifold algebras, which are obtained by replacing polynomial rings by quantum polynomial rings. In [6], the authors give necessary and sufficient conditions on a defining parameters to obtain Drinfeld orbifold algebras. In this article we generalize their result. It also simultaneously generalizes the result of [5] about quantum Drinfeld Hecke algebras.
Effect of radiation on convection in a top-heated enclosure

The top-heated enclosure is of considerable importance in many engineering situations, especially in crystal growth from vapor where it is used to minimize convection. In this work we present a combined numerical and experimental investigation of radiation induced convection to show that the convective stability of the top-heated enclosure is disrupted by heat transfer conditions at the wall. When the enclosure is not insulated, the thermal stratification of the fluid is modified by convective and radiative losses to the surrounding environment. This results in a double annular cell flow, which when cut by the laser sheet, shows a four-vortex pattern with a weak annular cell at the bottom and a large counter-rotating annular cell at the top. When the enclosure is insulated, the convective stability of the fluid is again disrupted; this time as a result of radiative heat transfer between the enclosing surfaces which drives two annular flow cells of relatively equal size. Excellent agreement was found between the numerical predictions and the experiment. Comparison between model and experiments show that radiation effects are important even at temperature levels as low as 300 C, and if these effects are not included, numerical predictions can be far removed from reality.
Exact Response of a Translating String With Arbitrarily Varying Length Under General Excitation

The exact response of a translating string with constant tension and arbitrarily varying length is determined under general initial conditions and external excitation. The governing equation is transformed to a standard hyperbolic equation using characteristic transformation. The domain of interest for the transformed equation is divided into groups of subdomains according to the properties of wave propagation. d'Alembert's solution for any point in the zeroth subdomain group is obtained by using the initial conditions. The solution is extended to the whole domain of interest by using the boundary conditions, and a recursive mapping is found for the solution in the second and higher groups of subdomains. The least upper bound of the displacement of the freely vibrating string is obtained for an arbitrary movement profile. The forced response of the string with nonhomogeneous boundary conditions is obtained using a transformation method and the direct wave method. A new method is used to derive the rate of change of the vibratory energy of the translating string from the system viewpoint. Three different approaches are used to derive and interpret the rate of change of the vibratory energy of the string within a control volume, and the energy growth mechanism of the string during retraction is elucidated. The solution methods are applied to a moving elevator cable with variable length. An interesting Parametric instability phenomenon in a translating string with sinusoidally varying length is discovered.
Rearrangement pathways in the bicyclo[4.4.1]undecane ring system

Abstract The readily available bicyclo[4.4.1]undecane ring system can be transformed into the isomeric bicyclo[5.3.1]undecane and bicyclo[5.4.0]undecane systems via related rearrangement pathways. The resultant products constitute the AB ring substructure of the taxane diterpenes and the BC ring substructure of the tigliane diterpenes, respectively.
The robustness of 'enemy-of-my-enemy-is-my-friend' alliances

We examine a three-player, three-stage game of alliance formation followed by multi-battle conflict. There are two disjoint sets of battlefields, each of which is associated with a player who competes only within that set. The common enemy competes in both sets of battlefields. An ‘enemy-of-my-enemy-is-my-friend’ alliance forms when the two players facing the common enemy agree on a pre-conflict transfer of resources among themselves. We examine the case in which the players may commit to binding ex post transfers (alliances with full commitment) and the case in which ex post transfers are not feasible (self-enforcing alliances). Models that utilize the lottery contest success function typically yield qualitatively different results from those arising in models with the auction contest success function. However, under both contest success functions, alliances with full commitment result in identical alliance transfers for all parameter configurations, and self-enforcing alliances yield identical transfers over a subset of the parameter space. Our results, thus, provide a partial robustness result for ‘enemy-of-my-enemy-is-my-friend’ alliances.
4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) Dyes Modified for Extended Conjugation and Restricted Bond Rotations

Five new, constrained, aryl-substituted 4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene (BODIPY) dyes (3f,g and 4h-j) were prepared and investigated to see if they have more favorable fluorescence characteristics than the unconstrained systems 2 that were prepared in previous studies. Dye types 3 and 4 have relatively rigid conformations caused by the heteroatom (3f and 3g) or ethylene bridge (4h-j) linkers that preclude free rotation of the substituted-benzene molecular fragments. In the event, the new dye types 3 and 4 have longer lambda(max abs) (620-660 nm) and lambda(max)(fluor) (630-680 nm) values than compounds 2. They also exhibit higher extinction coefficients (>100 000 M(-1) cm(-1), except for 3g). Their fluorescent quantum yields are high (up to 0.72 for 4j), with the exception of compound 3g, which has a quantum yield of only 0.05. The redox properties of dyes 3 and 4 have also been examined.
The broadband digital divide and the benefits of mobile broadband for minorities

This study sets out the facts regarding broadband deployment and usage in the US and the particular promise of mobile broadband for minorities. Fixed broadband is nearly ubiquitous and most people have access to four or more mobile broadband providers. Growth in fixed broadband usage is leveling off, while mobile broadband usage growth remains robust. Blacks and Hispanics generally have fewer fixed broadband options but more mobile broadband providers available. Gaps in broadband usage overall (fixed and mobile combined) for minorities persist and are quite large. Matching estimators show that lagging broadband adoption among minority groups is not fully accounted for by demographic and economic characteristics. Mobile broadband holds particular promise for minorities regarding healthcare and e-health, and these communities have relatively greater reliance on mobile forms of broadband. Two important findings are that 1) blacks are more likely to access the Internet using a mobile phone than whites (after controlling for demographic differences between the groups), and 2) there is no significant gap in mobile broadband usage between minorities and whites by either of the two measures of usage considered. Implications of the findings for policy toward spectrum allocation and wireless taxes are discussed.
Attribute-based on-demand multicast group setup with membership anonymity

In many applications, it is desired to dynamically establish temporary multicast groups for secure message delivery. It is also often the case that the group membership information itself is sensitive and needs to be well protected. However, existing solutions either fail to address the issue of membership anonymity or do not scale well for dynamically established groups. In this paper, we propose a highly scalable solution for dynamical multicast group setup with group membership anonymity. In the proposed solution, scalability and membership anonymity are achieved via a novel design that integrates techniques such as ciphertext-policy attribute-based encryption (CP-ABE). In our design, multicast groups are specified through group member attributes. As these attributes are potentially able to be shared by unlimited number of group members, our proposed scheme scales well. Also, high level of membership anonymity is guaranteed such that every group member knows nothing but his own group membership only. The complexity of our proposed scheme in terms of computational overhead and ciphertext size is O(n), where n is the number of attributes and independent to the group size.
Robust control by two chirped pulse trains in the presence of decoherence

We discuss a novel method to create maximum coherence in a two-level system that is selectively excited among many having similar frequencies by making use of two specifically chirped pulses in the Raman configuration. The feasibility of the method is analyzed in the presence of decoherence caused by vibrational energy relaxation and collisional dephasing. It has been demonstrated that a high value of coherence may be sustained by the implementation of two chirped pulse trains prepared in accordance with the proposed method and having the same period as the vibrational energy relaxation time.
Fabry-Perot measurements of the dynamics of globular cluster cores: M15 (NGC 7078)

We report the first use of the Rutgers Imaging Fabry-Perot Spectrophotometer to study the dynamics of the cores of globular clusters. We have obtained velocities for cluster stars by tuning the Fabry-Perot to take a series of narrow-band images at different wavelengths across one of the Na D (5890 AA) absorption lines. Measuring the flux in every frame yields a short portion of the spectrum for each star simultaneously. This proves to be a very efficient method for obtaining accurate stellar velocities; in crowded regions we are able to measure hundreds of velocities in 3-4 hours of observing time. We have measured velocities with uncertainties of less than 5 km/s for 216 stars within 1.5' of the center of the globular cluster M15 (NGC 7078). The paper is a uuencoded compressed postscript file.
Information Relaxation and Dual Formulation of Controlled Markov Diffusions

Information relaxation and duality in Markov decision processes have been studied recently by several researchers with the goal to derive dual bounds on the value function. In this paper we extend this dual formulation to controlled Markov diffusions: in a similar way we relax the constraint that the decision should be made based on the current information and impose a penalty to punish the access to the information in advance. We establish the weak duality, strong duality and complementary slackness results in a parallel way as those in Markov decision processes. We further explore the structure of the optimal penalties and expose the connection between the optimal penalties for Markov decision processes and controlled Markov diffusions. We demonstrate the use of this dual representation in a classic dynamic portfolio choice problem through a new class of penalties, which require little extra computation and produce small duality gap on the optimal value.
EFFICIENT SYNTHESIS OF 4-ETHOXYCARBONYL PYRAZOLIN-5-ONE DERIVATIVES

Concise and efficient methods for the preparation of 3-substituted 4-ethoxycarbonylpyrazolin-5-ones are described. The synthetic strategies involve carbon-acylation in the presence of base, followed by ring cyclization with hydrazine or hydrazine monohydrochloride.
The interaction of high-speed turbulence with flames: Turbulent flame speed

Direct numerical simulations of the interaction of a premixed flame with driven, subsonic, homogeneous, isotropic, Kolmogorov-type turbulence in an unconfined system are used to study the mechanisms determining the turbulent flame speed, S{sub T}, in the thin reaction zone regime. High intensity turbulence is considered with the r.m.s. velocity 35 times the laminar flame speed, S{sub L}, resulting in the Damkoehler number Da=0.05. The simulations were performed with Athena-RFX, a massively parallel, fully compressible, high-order, dimensionally unsplit, reactive-flow code. A simplified reaction-diffusion model, based on the one-step Arrhenius kinetics, represents a stoichiometric H{sub 2}-air mixture under the assumption of the Lewis number Le=1. Global properties and the internal structure of the flame were analyzed in an earlier paper, which showed that this system represents turbulent combustion in the thin reaction zone regime. This paper demonstrates that: (1) The flame brush has a complex internal structure, in which the isosurfaces of higher fuel mass fractions are folded on progressively smaller scales. (2) Global properties of the turbulent flame are best represented by the structure of the region of peak reaction rate, which defines the flame surface. (3) In the thin reaction zone regime, S{sub T} is predominantly determined by the increasemore » of the flame surface area, A{sub T}, caused by turbulence. (4) The observed increase of S{sub T} relative to S{sub L} exceeds the corresponding increase of A{sub T} relative to the surface area of the planar laminar flame, on average, by {approx}14%, varying from only a few percent to as high as {approx}30%. (5) This exaggerated response is the result of tight flame packing by turbulence, which causes frequent flame collisions and formation of regions of high flame curvature >or similar 1/{delta}{sub L}, or ''cusps,'' where {delta}{sub L} is the thermal width of the laminar flame. (6) The local flame speed in the cusps substantially exceeds its laminar value, which results in a disproportionately large contribution of cusps to S{sub T} compared with the flame surface area in them. (7) A criterion is established for transition to the regime significantly influenced by cusp formation. In particular, at Karlovitz numbers Ka >or similar 20, flame collisions provide an important mechanism controlling S{sub T}, in addition to the increase of A{sub T} by large-scale motions and the potential enhancement of diffusive transport by small-scale turbulence. (author)« less
Meteorological Infrared Instruments for Satellites

The study of meteorology deals with measurements of such parameters as pressure, temperature, humidity, wind, cloud cover, cloud altitude, and precipitation. Until the advent of weather satellites adequate coverage on a global basis was not feasible. However, since the satellite moves in an orbit which is outside the atmosphere, spacecraft measurements of meteorological parameters must be limited to those that can be sensed by electro-magnetic radiation. In some cases as we shall see later, it is possible to infer some meteorological parameters by indirect methods.
Transient Solutions for One-Dimensional Problems With Strain Softening

Closed-form solutions are presented for the transient response of rods in which strain softening occurs and the stress-strain laws exhibit nonvanishing stresses after the strain-softening regime. It is found that the appearance of any strain softening results in an infinite strain rate if the material is inviscid. For a stress-strain law with a monotonically decreasing stress the strains are infinite also. If the stress increases after the strain-softening portion, the strains remain finite and the strain-softening point moves through the rod.
A general approach to the synthesis of dideoxy and trideoxyiminoalditols from β-d-glycosides

Abstract Imino sugars (also called azasugars), a class of compounds of which the 1,5-dideoxy and 1,5,6-trideoxyiminoalditols are members, are important glycosidase inhibitors with very high potential as drugs. Their potential therapeutic applications range from the treatment of diabetes to cancer and AIDS. We present here a general method for the preparation of such compounds with the d -gluco and d -galacto configurations starting from β- d -glycosides. The procedure is especially appealing because of its high stereoselectivity and straightforwardness. The key steps are the selective oxidation of the glycosides to hexulosonic acids and reduction of the oxime derivatives to lactams, which are further reduced to the target compounds. The C-6 position can be deoxygenated during the reduction if it bears an acetoxy group. Trideoxy imino sugars are then produced. Deacetylation prior to oxime reduction gives dideoxy compounds.
Management of acute leukemia in adults

The treatment of acute leukemia in adults, while not yet as successful as that in children with regard to either remission rate or prolongation of life, can now regularly result in at least 50% responses in acute myelocytic leukemia and 70-80% in acute lymphocytic leukemia. Intensive specific chemotherapy and supportive therapy throughout the resultant period of myelo and immuno-suppression are necessary to achieve these remission rates. Further investigations aimed at both prolonging the remissions so obtained and at improving the response rate further are essential.
How to throw the race to the bottom: revisiting signals for ethical and legal research using online data

With research using data available online, researcher conduct is not fully prescribed or proscribed by formal ethical codes of conduct or law because of ill-fitting "expectations signals" -- indicators of legal and ethical risk. This article describes where these ordering forces breakdown in the context of online research and suggests how to identify and respond to these grey areas by applying common legal and ethical tenets that run across evolving models. It is intended to advance the collective dialogue work-in-progress toward a path that revisits and harmonizes more appropriate ethical and legal signals for research using online data between and among researchers, oversight entities, policymakers and society.
Flight Evaluation of Augmented Controls for Approach and Landing of Powered-Lift Aircraft

Flight experiments were conducted with Ames Research Center's Quiet Short-Haul Research Aircraft to evaluate the influence of highly augmented control modes on the ability of pilots to execute precision instrument flight operations in the terminal area, particularly approaches to and landings on a short runway. The aircraft is a powered-lift, short-takeoff and landing configuration that is equipped with a modern digital fly-by-wire flight control system, a head-up display, and a solar head-down display that make it possible to investigate control concepts and display format and content for full envelope, powered-lift operations. Considerable attention has been devoted in this flight program to assessing flightpath and airspeed command and stabilization modes developed using nonlinear, inverse model-following methods. The primary benefit of this control concept was realized when the pilot was required to execute a complex transition and approach under instrument conditions and in the presence of a wide range of wind and turbulence conditions.
Exact partition functions for Potts antiferromagnets on cyclic lattice strips

Abstract We present exact calculations of the zero-temperature partition function of the q -state Potts antiferromagnet on arbitrarily long strips of the square, triangular, and kagome lattices with width L y =2 or 3 vertices and with periodic longitudinal boundary conditions. From these, in the limit of infinite length, we obtain the exact ground-state entropy S 0 =k B ln W . These results are of interest since this model exhibits nonzero ground-state entropy S 0 >0 for sufficiently large q and hence is an exception to the third law of thermodynamics. We also include results for homeomorphic expansions of the square lattice strip. The analytic properties of W ( q ) are determined and related to zeros of the chromatic polynomial for long finite strips.
Self-referenced characterization of optical frequency combs and arbitrary waveforms using a simple, linear, zero-delay implementation of spectral shearing interferometry.

We discuss a simple, linear, zero-delay implementation of spectral shearing interferometry for amplitude and phase characterization of optical frequency comb sources and arbitrary waveforms. We demonstrate this technique by characterizing two different high repetition rate (~10 GHz) frequency comb sources, generated respectively by strong external and intracavity phase modulation of a continuous-wave laser. This technique is easy to implement, requiring only an intensity modulator and an optical spectrum analyzer (OSA), and is demonstrated to work at average power levels down to 100nW (10aJ/pulse at 10 GHz). By exploiting the long coherence lengths of these frequency combs and the self-referenced nature of the measurement, we also demonstrate a simple single-ended measurement of dispersion and dispersion slope in long lengths of fiber (>25km).
Mobile source emission control cost-effectiveness: Issues, uncertainties, and results

Abstract Government agencies and private organizations often use cost-effectiveness, calculated in dollars per ton of emissions reduced for various control measures, to determine which control measures should be implemented to meet emission reduction requirements. Different studies may, however, yield significantly different, sometimes contradicting, results for the same control measures. The results differ because of the various calculation methodologies used and assumptions made about the values of costs and emission reductions. This paper examines some important methodological issues involved in calculating the cost-effectiveness of mobile source control measures and proposes appropriate methods for calculating cost-effectiveness. Included are such issues as using user costs or societal costs, using costs at the manufacturer or the consumer level, determining baseline emissions, using emission reductions in nonattainment or in both nonattainment and attainment areas, using annual or pollution-season emission reductions, considering multiple-pollutant emission reductions, and applying emission discounting. This paper then reviews methodologies used in 11 studies recently completed in the United States on the cost effectiveness of mobile source control measures. On the basis of the methods proposed here for addressing the above issues, the original estimates in each study are modified to correct inconsistent or inappropriate methods so that the studies are comparable. From the adjusted results, the paper presents relative cost-effectiveness of 19 mobile source emission control measures.
Pyrolysis of Sunnyside (Utah) tar sand: Characterization of volatile compound evolution

ABSTRACT Sunnyside (Utah) tar sand was subjected to programmed temperature pyrolysis and the volatile products were detected by tandem on-line mass spectrometry (MS/MS) in real time analyses. A heating rate of 4°C/min from room temperature to 900°C was employed. Evolution of hydrogen, light hydrocarbons, nitrogen-, sulfur-, and oxygen-containing compounds was monitored by MS or MS/MS detection. Evolution of volatile organic compounds occurred in two regimes: 1) low temperature (maximum evolution at 150 to 175°C), corresponding to entrained organics, and 2) high temperature (maximum evolution at 440 to 460°C), corresponding to cracking of large organic components. Alkanes and alkenes of two carbons and higher had temperatures of maximum evolution at approximately 440°C, and methane at approximately 474°C. Aromatic hydrocarbons had temperatures of maximum evolution slightly higher, at approximately 450° C. Some nitrogen-, sulfur-, and oxygen-'ccntaining compounds were also detected in the volatile products....
Isolating Red Giant Stars in M31's Elusive Outer Spheroid

Deep UBRI images of a 15' × 15' field in the outer spheroid of the galaxy M31 obtained using the Kitt Peak National Observatory's 4 m telescope and I-band images obtained with the Keck 10 m telescope and Low Resolution Imaging Spectrograph are used to isolate a sample of candidate red giant branch stars located at a projected radial distance of 19 kpc along the minor axis. These stars are distinguished from the more numerous distant field galaxies on the basis of broadband U - B, B - R, and R - I colors and image morphology; we isolate objects whose colors are consistent with the long, but relatively narrow, locus occupied by red giants in UBRI color space (as observed in Galactic globular cluster giants and predicted by models spanning a wide range of metallicities and ages), and those whose angular sizes are consistent with the stellar point-spread function, FWHM = 06–09 (Keck) and FWHM = 09–15 (Kitt Peak). We carry out the same analysis of data on a comparison field with a Galactic latitude similar to the M31 halo field. The color-magnitude diagram of objects in the comparison field is well described by a superposition of foreground Galactic dwarf stars (in keeping with a standard empirical model of the Galaxy) against a backdrop of contaminating faint blue field galaxies (I 21, B - I ~ 1–2.5), while the M31 halo field contains a clear excess of faint red objects (I ~ 20–23, B - I ~ 2–3.5) in addition to these two components. The location of this population of faint red objects in the color-magnitude diagram is as would be expected for red giant stars at the distance of M31. The surface density of RGB candidates in the R = 19 kpc M31 halo field is consistent with the findings of two recent Hubble Space Telescope (HST) studies. The data indicate that M31's halo is much denser and/or larger than that of the Galaxy: (ρ/ρ)(Λ/1.5)-ν ~ 10 , where Λ is the ratio of the radial scale lengths of M31 and the Galaxy and ν = -3.8 is the assumed power-law index of the density profile; in fact, M31's profile may be steeper than this (ν < -3.8). The color and slope of the red giant branch in M31's outer halo are suggestive of a relatively metal-rich population, [Fe/H] -1, in agreement with the HST measurements.
The Interactive Digital Entertainment (IDE) Unification Framework: Creating a Taxonomy of IDE and Lifestyle Computing

In this paper, we create a taxonomy of interactive digital entertainment (IDE), which can be used to guide future research in IDE and direct the design of interactive entertainment. We start by defining and explaining the differences between IDE and lifestyle computing. We then review the major taxonomies on gaming that can illuminate research and practice with IDE. Given this review, we propose an overarching taxonomy called the IDE unification framework. Based on this framework, we then propose promising areas for future research
The Dirichlet problem for superdegenerate differential operators

Abstract Let L be an infinitely degenerate second-order linear operator defined on a bounded smooth Euclidean domain. Under weaker conditions than those of Hormander, we show that the Dirichlet problem associated with L has a unique smooth classical solution. The proof uses the Malliavin calculus. At present, there appears to be no proof of this result using classical analytic techniques.
Symmetry relations in viscoplastic drag laws

The following note shows that the symmetry of various resistance formulae, often based on Lorentz reciprocity for linearly viscous fluids, applies to a wide class of nonlinear viscoplastic fluids. This follows from Edelen's nonlinear generalization of the Onsager relation for the special case of strongly dissipative rheology, where constitutive equations are derivable from his dissipation potential. For flow domains with strong dissipation in the interior and on a portion of the boundary, this implies strong dissipation on the remaining portion of the boundary, with strongly dissipative traction–velocity response given by a dissipation potential. This leads to a nonlinear generalization of Stokes resistance formulae for a wide class of viscoplastic fluid problems. We consider the application to nonlinear Darcy flow and to the effective slip for viscoplastic flow over textured surfaces.
Orbit design concepts for Jupiter orbiter missions

Advanced mission and orbit planning efforts are currently in progress for a Mariner-class Jupiter orbiter. Baseline spacecraft and orbit design criteria are the goals of a NASA effort to define such a mission. Orbit design concepts that have been discovered during the early stages of mission planning are both challenging and exciting. A description is given of several such concepts that may greatly increase the flexibility and scientific return of orbiters designed for close study of the Galilean satellites and exploration of the Jovian system. Some new jargon is introduced in discussions to describe the exploitation of gravity-assist trajectories using the giant satellites for orbit control. Orbit 'pumping' and 'cranking' and 'resonance hopping' are defined and shown to be dynamically feasible means of controlling the orbit and, thus, the scientific return. A candidate encounter sequence is presented for an equatorial tour of the Galilean moons.
A Model for the Moving “Wisps” in the Crab Nebula

I propose that the moving "wisps" near the center of the Crab Nebula result from nonlinear Kelvin-Helmholtz instabilities in the equatorial plane of the shocked pulsar wind. Recent observations suggest that the wisps trace out circular wave fronts in this plane, expanding radially at speeds c/3. Instabilities could develop if there is sufficient velocity shear between a faster moving equatorial zone and a slower moving shocked pulsar wind at higher latitudes. The development of shear could be related to the existence of a neutral sheet—with a weak magnetic field—in the equatorial zone, and could also be related to a recent suggestion in the literature that the magnetic field in the Crab pulsar wind is much stronger than had been thought. I show that plausible conditions could lead to the growth of instabilities at the radii and speeds observed, and that their nonlinear development could lead to the appearance of sharp wisplike features.
Biogenetically inspired syntheses of alkaloid natural products

Since the synthesis of tropinone in the early 20th century, generations of chemists have looked to nature for inspiration in developing elegant syntheses of natural products. Analyzing molecules in their native context greatly enriches the chemist’s understanding of nature’s solution to the rapid generation of molecular complexity. In this tutorial review, we examine select examples from the alkaloid literature to highlight ways in which the close interplay of chemistry and biology have resulted in the development of elaborate biosynthetic hypotheses as well as strikingly beautiful syntheses. In addition, we present a case study on this topic through the lens of our total synthesis of (+)-11,11′-dideoxyverticillin A.
Link scheduling with power control for throughput enhancement in multihop wireless networks

Joint scheduling and power control schemes have previously been proposed to reduce power dissipation in wireless ad hoc networks. However, instead of power consumption, throughput is a more important performance concern for some emerging multihop wireless networks, such as wireless mesh networks. This paper examines joint link scheduling and power control with the objective of throughput improvement. The MAximum THroughput link Scheduling with Power Control (MATH-SPC) problem is first formulated and then a mixed integer linear programming (MILP) formulation is presented to provide optimal solutions. However, simply maximizing the throughput may lead to a severe bias on bandwidth allocation among links. To achieve a good tradeoff between throughput and fairness, a new parameter called the demand satisfaction factor (DSF) to characterize the fairness of bandwidth allocation and formulate the MAximum Throughput fAir link Scheduling with Power Control (MATA-SPC) problem is defined. An MILP formulation and an effective polynomial-time heuristic algorithm, namely, the serial linear programming rounding (SLPR) heuristic, to solve the MATA-SPC problem are also presented. Numerical results show that bandwidth can be fairly allocated among all links/flows by solving the MILP formulation or by using the heuristic algorithm at the cost of a minor reduction of network throughput. In addition, extensions to end-to-end throughput and fairness and multiradio wireless multihop networks are discussed
A self-tuning cache architecture for embedded systems

Memory accesses can account for about half of a microprocessor system's power consumption. Customizing a microprocessor cache's total size, line size and associativity to a particular program is well known to have tremendous benefits for performance and power. Customizing caches has until recently been restricted to core-based flows, in which a new chip will be fabricated. However, several configurable cache architectures have been proposed recently for use in pre-fabricated microprocessor platforms. Tuning those caches to a program is still however a cumbersome task left for designers, assisted in part by recent computer-aided design (CAD) tuning aids. We propose to move that CAD on-chip, which can greatly increase the acceptance of configurable caches. We introduce on-chip hardware implementing an efficient cache tuning heuristic that can automatically, transparently, and dynamically tune the cache to an executing program. We carefully designed the heuristic to avoid any cache flushing, since flushing is power and performance costly. By simulating numerous Powerstone and MediaBench benchmarks, we show that such a dynamic self-tuning cache can reduce memory-access energy by 45% to 55% on average, and as much as 97%, compared with a four-way set-associative base cache, completely transparently to the programmer.
Substrate Trafficking and Dioxygen Activation in Bacterial Multicomponent Monooxygenases

Non-heme carboxylate-bridged diiron centers in the hydroxylase components of the bacterial multicomponent monooxygenases process four substrates during catalysis: electrons, protons, dioxygen, and hydrocarbons. Understanding how protein–protein interactions mediate the transport of these substrates to the diiron center to achieve the selective oxidation of the hydrocarbon is a significant challenge. In this Account, we summarize our current knowledge of these processes with a focus on the methane monooxygenase system. We also describe recent results for the toluene/o-xylene monooxygenase and phenol hydroxylase systems from Pseudomonas sporium OX1. The observation in these latter systems of a diiron(III) oxygenated intermediate having different Mossbauer parameters from analogous species in other carboxylate-bridged diiron proteins is discussed. The results indicate that the ability of the protein framework to tune the reactivity of the diiron center at structurally similar active sites is substantially mo...
Combinatorial and computational challenges for biocatalyst design

Nature provides a fantastic array of catalysts extremely well suited to supporting life, but usually not so well suited for technology. Whether biocatalysis will have a significant technological impact depends on our finding robust routes for tailoring nature's catalysts or redesigning them anew. Laboratory evolution methods are now used widely to fine-tune the selectivity and activity of enzymes. The current rapid development of these combinatorial methods promises solutions to more complex problems, including the creation of new biosynthetic pathways. Computational methods are also developing quickly. The marriage of these approaches will allow us to generate the efficient, effective catalysts needed by the pharmaceutical, food and chemicals industries and should open up new opportunities for producing energy and chemicals from renewable resources.
Sweeping preconditioner for the Helmholtz equation: Hierarchical matrix representation

The paper introduces the sweeping preconditioner, which is highly efficient for iterative solutions of the variable-coefficient Helmholtz equation including very-high-frequency problems. The first central idea of this novel approach is to construct an approximate factorization of the discretized Helmholtz equation by sweeping the domain layer by layer, starting from an absorbing layer or boundary condition. Given this specific order of factorization, the second central idea is to represent the intermediate matrices in the hierarchical matrix framework. In two dimensions, both the construction and the application of the preconditioners are of linear complexity. The generalized minimal residual method (GMRES) solver with the resulting preconditioner converges in an amazingly small number of iterations, which is essentially independent of the number of unknowns. This approach is also extended to the three-dimensional case with some success. Numerical results are provided in both two and three dimensions to demonstrate the efficiency of this new approach.
Luminescent Metal–Organic Frameworks

Metal–organic frameworks (MOFs) display a wide range of luminescent behaviors resulting from the multifaceted nature of their structure. In this critical review we discuss the origins of MOF luminosity, which include the linker, the coordinated metal ions, antenna effects, excimer and exciplex formation, and guest molecules. The literature describing these effects is comprehensively surveyed, including a categorization of each report according to the type of luminescence observed. Finally, we discuss potential applications of luminescent MOFs. This review will be of interest to researchers and synthetic chemists attempting to design luminescent MOFs, and those engaged in the extension of MOFs to applications such as chemical, biological, and radiation detection, medical imaging, and electro-optical devices (141 references).