cssi/SciSciGPT-SciSciNet huggingface dataset:
Biology and technology for photochemical fuel production

Sunlight is the ultimate energy source for the vast majority of life on Earth, and organisms have evolved elegant machinery for energy capture and utilization. Solar energy, whether converted to wind, rain, biomass or fossil fuels, is also the primary energy source for human-engineered energy transduction systems. This tutorial review draws parallels between biological and technological energy systems. Aspects of biology that might be advantageously incorporated into emerging technologies are highlighted, as well as ways in which technology might improve upon the principles found in biological systems. Emphasis is placed upon artificial photosynthesis, as well as the use of protonmotive force in biology.
BINARY PLANETESIMALS AND THEIR ROLE IN PLANET FORMATION

One of the main evolutionary stages of planet formation is the dynamical evolution of planetesimal disks. These disks are thought to evolve through gravitational encounters and physical collisions between single planetesimals. In recent years, many binary planetesimals (BPs) have been observed in the solar system, indicating that the binarity of planetesimals is high. However, current studies of planetesimal disk formation and evolution do not account for the role of binaries. Here, we point out that gravitational encounters of BPs can have an important role in the evolution of planetesimal disks. BPs catalyze close encounters between planetesimals and can strongly enhance their collision rate. Binaries may also serve as an additional heating source of the planetesimal disk, through the exchange of the binaries gravitational potential energy into the kinetic energy of planetesimals in the disk.
An Analysis of Closed‐end Fund Seasoned Equity Offerings

We examine the stock price reaction to seasoned equity offerings (SEOs) of closed-end funds and the determinants of the issuance decision. We find that sample funds have negative and significant average announcement-day returns that are less than the returns associated with industrial firm SEOs, most likely because funds have fewer information asymmetries. Issuing funds have higher pre-issue returns, higher premiums, lower betas, and lower three-year, post-issue returns than nonissuing funds. The results of the study are consistent with the argument that fund managers time issues to take advantage of mean reversion in fund returns.
NP-Completeness of st-orientations for plane graphs

An st-orientation or bipolar orientation of a 2-connected graph G is an orientation of its edges to generate a directed acyclic graph with a single source s and a single sink t. Given a plane graph G and two exterior vertices s and t, the problem of finding an optimum st-orientation, i.e., an st-orientation in which the length of a longest st-path is minimized, was first proposed indirectly by Rosenstiehl and Tarjan in and then later directly by He and Kao in . In this paper, we prove that, given a 2-connected plane graph G, two exterior vertices s, t, and a positive integer K, the decision problem of whether G has an st-orientation, where the maximum length of an st-path is @?K, is NP-Complete. This solves a long standing open problem on the complexity of optimum st-orientations for plane graphs. As a by-product, we prove that the NP-Completeness result holds for planar graphs as well.
A Simple Method of Protecting a Secondary Amine with Tert Butyloxycarbonyl (Boc) in the Presence of a Primary Amine

Abstract A simple method for chemically differentiating primary and secondary amines is described in which the primary amine is condensed with benzaldehyde to form an imine leaving the secondary amine available to be protected with BOC. The imine is then hydrolyzed to provide the free primary amine.
Synthesis and Thermal Expansion of MZr4P6O24 (M=Mg, Ca, Sr, Ba)

MZr4P6O24 (M=Mg, Ca, Sr, Ba), which belongs to a new, low-thermal-expansion family of materials known as [NZP] or [CTP], were synthesized by solid-state reaction (oxide mixing) and sol-gel methods, and their sinterability in two cases was investigated and compared. Thermal-expansion measurements were made on sintered samples by dilatometry, high-temperature X-ray diffractometry, and the laser speckle technique. An anisotropy in axial thermal-expansion coefficients was observed in these materials. CaZr4P6O24 and SrZ4P6O24 showed reverse anisotropy as well as opposite bulk thermal expansion; i.e., CaZr4P6O24 had negative bulk thermal expansion and SrZr4P6O24 positive bulk thermal expansion in the temperature range 25° to 500°C. The microstructure of the sintered samples was also examined by scanning electron microscopy.
Inpatient hysterectomy surveillance in the United States, 2000-2004

Objective The objective of the study was to examine recent trends in hysterectomy rates and indications in the United States. Study Design Data on hysterectomy hospitalizations during 2000-2004 were obtained from the National Hospital Discharge Survey, an annual nationally representative survey of inpatient hospitalization records. Results The hysterectomy rate decreased slightly from 5.4 per 1000 in 2000 to 5.1 per 1000 in 2004 ( P for trend P for trend P for trend Conclusions Continued monitoring is needed to determine whether the observed trends persist and to evaluate impact on women's health. In the future, information on both inpatient and outpatient procedures may be important for hysterectomy surveillance.
Variations of atmospheric properties with time and solar activity

Abstract Variations of atmospheric properties with time and solar activity have been determined from results available at present. These are primarily densities derived from the variation of orbital decelerations which are due to atmospheric drag. For medium solar activity, the possible variation of density over 24 hr periods at 350 and 650 km is shown. For the same altitudes, the possible hourly variations which might occur during high and low solar activities have been studied. As a result of these investigations, it is shown that the density for the same altitude at night (about 2 hr before local sunrise), during minimum solar activity, may vary by a factor of 200 when compared with the density occurring during the day (about 2 hr after local noontime) during solar maximum activity. Pressure, scale height, molecular weight, temperature and thermal heat flow variations, which may occur during medium solar activity over a 24 hr period at 350 and 650 km, have been derived from maximum and minimum densities and molecular weights at these altitudes, which were accepted in the CIRA 1961 tables. The 24 hr temperature variations, which may occur at 650 km, are compared with experimental results obtained by other scientists. The theoretical values presented here agree fairly well with experimental results. The temperature difference between day and night is about 700°K.
Metal-free amidation of ether sp3 C–H bonds with sulfonamides using PhI(OAc)2

A selective protocol for the metal-free α-C–H amidation of ethers using sulfonamides and hypervalent iodine oxidants has been developed. The absence of precious metals and the conditions employed make the method environmentally attractive. A number of cyclic and acyclic, linear and branched ethers have been successfully amidated, and a broad sulfonamide scope has been demonstrated. Two unusual reactions, namely the amidation of an unactivated tert-butyl group and a tandem C–C coupling reaction, are also described.
Oxygen isotopes in shergotty

Abstract Oxygen isotopic fractionation among the major mineral phases of Shergotty corresponds to a temperature of last equilibration of about 1100°C. There are no large departures from equilibrium due to metamorphism, shock, or retrograde exchange. On the oxygen three-isotope plot, the shergottites, nakhlites, and chassignites form a unique group, consistent with their having originated in a common parent body. Too little is known about the spatial and temporal variation of oxygen isotope abundances in the early solar system to allow identification of the SNC meteorites with any particular parent body.
Supersonic, transverse jet from a rotating ogive cylinder in a hypersonic flow

Abstract : Numerical simulations were performed for a supersonic jet issuing from a blunt-nosed ogive cylinder into a Mach 12 cross stream. All calculations employed the finite differenced, mass-averaged Navier Stokes equations with an algebraic eddy viscosity model for turbulence closure. One portion of the present investigation was focused on the numerical resolution requirement for the three-dimensional separated flow field around the non-rotating body. For this purpose, four solutions were obtained using mesh systems with different numbers of grid points and clustering. The secondary separated flow field structure was resolved with moderately increased grid density. The major portion of the present study was devoted to the simulation of the flow field around the identical configuration with the added complexity of rotating motion about the principal axis of the body. Numerical solutions over a wide range of angular velocities were obtained in the rotating frame of reference. The effects of rotation on the global flow field structure and especially the jet plume formation were examined through a comparative study from the viewpoint of a stationary observer. At the low angular velocity of interest, the effects of body rotation on the flow field structure were significant.
Interaction techniques for ambiguity resolution in recognition-based interfaces

Because of its promise of natural interaction, recognition is coming into its own as a mainstream technology for use with computers. Both commercial and research applications are beginning to use it extensively. However the errors made by recognizers can be quite costly, and this is increasingly becoming a focus for researchers. We present a survey of existing error correction techniques in the user interface. These mediation techniques most commonly fall into one of two strategies, repetition and choice. Based on the needs uncovered by this survey, we have developed OOPS, a toolkit that supports resolution of input ambiguity through mediation. This paper describes four new interaction techniques built using OOPS, and the toolkit mechanisms required to build them. These interaction techniques each address problems not directly handled by standard approaches to mediation, and can all be re-used in a variety of settings.
Signaling Firm Performance Through Financial Statement Presentation: An Analysis Using Special Items

This paper investigates whether managers’ presentation of special items within the financial statements reflects economic performance or opportunism. Specifically, we assess special items presented as a separate line item on the income statement (income statement presentation) to those aggregated within another line item with disclosure only in the footnotes (footnote presentation). Our study is motivated by standard-setting interest in performance reporting and financial statement presentation, as well as prior research investigating managers’ presentation choices in other contexts. Empirical results reveal that special items receiving income statement presentation are less persistent relative to those receiving footnote presentation. These results are consistent across numerous alternative specifications. Overall, the findings are consistent with managers using the income statement versus footnote presentation to assist users in identifying those special items most likely to differ from other components of earnings — that is, for informational, as opposed to opportunistic, motivations.
Asymptotics of d-dimensional Kaluza-Klein black holes: Beyond the Newtonian approximation

We study the thermodynamics of small black holes in compactified spacetimes of the form Rd?1 ? S1. This system is analyzed with the aid of an effective field theory (EFT) formalism in which the structure of the black hole is encoded in the coefficients of operators in an effective worldline Lagrangian. In this effective theory, there is a small parameter ? that characterizes the corrections to the thermodynamics due to both the non-linear nature of the gravitational action as well as effects arising from the finite size of the black hole. Using the power counting of the EFT we show that the series expansion for the thermodynamic variables contains terms that are analytic in ?, as well as certain fractional powers that can be attributed to finite size operators. In particular our operator analysis shows that existing analytical results do not probe effects coming from horizon deformation. As an example, we work out the order ?2 corrections to the thermodynamics of small black holes for arbitrary d, generalizing the results in the literature.
A Kinship Parable

Author(s): Read, Dwight W | Abstract: The protagonist of the parable, Eager Graduate Student (EG), wants to apply the idea of cultural consensus and goes to the field and finds a set of terms the villagers use to refer to each other. EG elicits data by using triad questions and works out the semantic links among the terms. He finds that the semantic domain he has elicited is also a cultural domain based on consensus analysis. When he returns and talks with Prof. Silverback about his research, Prof. Silverback tells him he has been eliciting kin terms and he should go back and use a genealogical framework instead of the triad questions. EG suggests that they try a new program called Kinship Algebra Expert System and to their astonishment the program works out the logical structure for the semantic domain. Even more, it predicts the genealogical definitions of the kin terms even though EG had not asked his informants about the way kin terms relate to genealogy. Prof. Silverback is very disturbed as the computer program is able to predict the genealogical definition of the kin terms, which challenges longstanding assumptions in anthropology about the primacy of genealogy for understanding kinship. The enormity of what has happened slowly begins to sink in as he realizes that “this is telling us something fundamental about human cognition, perhaps something about culture … about what it means to be human!”
Constructing the Tree-Level Yang-Mills S-Matrix Using Complex Factorization

A remarkable connection between BCFW recursion relations and constraints on the S-matrix was made by Benincasa and Cachazo in 0705.4305, who noted that mutual consistency of different BCFW constructions of four-particle amplitudes generates non-trivial (but familiar) constraints on three-particle coupling constants — these include gauge invariance, the equivalence principle, and the lack of non-trivial couplings for spins > 2. These constraints can also be derived with weaker assumptions, by demanding the existence of four-point amplitudes that factorize properly in all unitarity limits with complex momenta. From this starting point, we show that the BCFW prescription can be interpreted as an algorithm for fully constructing a tree-level S-matrix, and that complex factorization of general BCFW amplitudes follows from the factorization of four-particle amplitudes. The allowed set of BCFW deformations is identified, formulated entirely as a statement on the three-particle sector, and using only complex factorization as a guide. Consequently, our analysis based on the physical consistency of the S-matrix is entirely independent of field theory. We analyze the case of pure Yang-Mills, and outline a proof for gravity. For Yang-Mills, we also show that the well-known scaling behavior of BCFW-deformed amplitudes at large z is a simple consequence of factorization. For gravity, factorization in certain channels requires asymptotic behavior ~ 1/z2.
Lightweight and high angular resolution x-ray optics for astronomy

Astronomical observation in the x-ray band (wavelength from ~100 - 0.1 Angstroms) must take place above the atmosphere on a space platform. The most effective means of collecting x-ray photons is with imaging optics. As such lightweight and high angular resolution optics are essential for continued success of x-ray astronomy in coming years and decades. In this paper, I will briefly review the development of x-ray optics for astronomy in the past few decades and outline the technical approaches that we have adopted at the Goddard Space Flight Center for developing lightweight and high resolution x-ray optics to enable small and medium missions that can be implemented in the current decade as well flagship missions that can be implemented in the 2020's.
Wave packet revivals and the energy eigenvalue spectrum of the quantum pendulum

Abstract The rigid pendulum, both as a classical and as a quantum problem, is an interesting system as it has the exactly soluble harmonic oscillator and the rigid rotor systems as limiting cases in the low- and high-energy limits, respectively. The energy variation of the classical periodicity (τ) is also dramatic, having the special limiting case of τ→∞ at the ‘top’ of the classical motion (i.e., the separatrix.) We study the time-dependence of the quantum pendulum problem, focusing on the behavior of both the (approximate) classical periodicity and especially the quantum revival and superrevival times, as encoded in the energy eigenvalue spectrum of the system. We provide approximate expressions for the energy eigenvalues in both the small and large quantum number limits, up to fourth order in perturbation theory, comparing these to existing handbook expansions for the characteristic values of the related Mathieu equation, obtained by other methods. We then use these approximations to probe the classical periodicity, as well as to extract information on the quantum revival and superrevival times. We find that while both the classical and quantum periodicities increase monotonically as one approaches the ‘top’ in energy, from either above or below, the revival times decrease from their low- and high-energy values until very near the separatrix where they increase to a large, but finite value.
NEAR-INFRARED PHOTOMETRY OF THE TYPE IIn SN 2005ip : THE CASE FOR DUST CONDENSATION

Near-infrared photometric observations of the Type IIn supernova (SN) 2005ip in NGC 2906 reveal large fluxes (>1.3 mJy) in the Ks -band over more than 900 days. While warm dust can explain the late-time Ks -band emission of SN 2005ip, the nature of the dust heating source is ambiguous. Shock heating of pre-existing dust by post-shocked gas is unlikely because the forward shock is moving too slowly to have traversed the expected dust-free cavity by the time observations first reveal the Ks emission. While an infrared light echo model correctly predicts a near-infrared luminosity plateau, heating dust to the observed temperatures of ~ 1400-1600 K at a relatively large distance from the supernova (1018 cm) requires an extraordinarily high early supernova luminosity (~1 × 1011 L ☉). The evidence instead favors condensing dust in the cool, dense shell between the forward and reverse shocks. Both the initial dust temperature and the evolutionary trend toward lower temperatures are consistent with this scenario. We infer that radiation from the circumstellar interaction heats the dust. While this paper includes no spectroscopic confirmation, the photometry is comparable to other supernovae that do show spectroscopic evidence for dust formation. Observations of dust formation in supernovae are sparse, so these results provide a rare opportunity to consider supernovae Type IIn as dust sources.
Heavy ion collisions and AdS/CFT

We review some recent applications of the AdS/CFT correspondence to heavy ion collisions including a calculation of the jet quenching parameter in super-Yang?Mills theory and quarkonium suppression from velocity scaling of the screening length for a heavy quark?antiquark pair. We also briefly discuss differences and similarities between QCD and super-Yang?Mills theory.
Homogeneous genetic algorithms

A new type of genetic algorithm (GA) is developed to mitigate one or both of the following two major difficulties that traditional GAs may suffer: (1) when the number of 'active genes' needs to be held constant or kept within some prescribed range, and (2) when the set of genes is much larger than the set of active genes of feasible solutions under consideration. These homogeneous GAs use (unordered) sets to represent 'active genes' in chromosomes rather than strings, and a correspondingly natural crossover operator is introduced. 'Homogeneous' refers to the fact that, in contrast to traditional GAs where pairs of genes that are 'close' have better chances of being preserved under crossover, there is no notion of proximity between pairs of genes. Examples are provided that will demonstrate superior performance of these new GAs for some typical problems in which these difficulties arise.
Topographic mapping from interferometric synthetic aperture radar observations

The production of high-resolution topographic maps derived from interferometric synthetic aperture radar observations of the earth is reported. Topographic maps are typically determined from stereo-pair optical photographs. Vertical relief causes the same terrain to appear in a slightly different projection for differing look angles, and this shift in appearance is interpreted in terms of the height of the terrain. The radar interferometric approach is related to the stereo technique in that the terrain is viewed at two different angles; however, in this case, the angular separation of the antennas is extremely small, on the order of a milliradian or less, as compared to tens of degrees for the optical case. Thus, the geometrical distortion and subsequent rectification correction algorithms are much less severe in the reduction of interferometric data.
A Risk-Theory Model to Assess the Capital Requirement for Mortality and Longevity Risk

AbstractThere is considerable uncertainty regarding the future development of life expectancy that leads to significant change in many fields of the insurance market. Pricing annuity products and mortality-linked securities seem primary goals of actuarial literature. At the same time, the valuation of non-hedgeable liabilities (as technical provisions for contracts where risk is not entirely borne by the policyholders) and the estimation of capital requirement appear very important issues in Solvency II framework. In this context, we propose a model based on Risk Theory in order to evaluate the capital requirement for mortality and longevity risk. We assume a life portfolio characterized by traditional and with-profit products divided in several homogeneous generations of contracts. Each cohort includes equal contracts that differ only by the insured sum with the aim to consider the effect of variability coefficient. Some assumptions allow to obtain closed formulae for the exact characteristics of demogra...
New interpretations for noncrossing partitions of classical types

We interpret noncrossing partitions of type B and type D in terms of noncrossing partitions of type A. As an application, we get type-preserving bijections between noncrossing and nonnesting partitions of type B, type C and type D which are different from those in the recent work of Fink and Giraldo. We also define Catalan tableaux of type B and type D, and find bijections between them and noncrossing partitions of type B and type D respectively.
Synthesis of variants of 5‐benzylacyclouridine and 5‐benzyloxybenzylacyclouridine

A number of variations and derivatives of BAU (5-benzylacyclouridine) and BBAU (5-benzyloxybenzylacy-clouridine), potent inhibitors of uridine phosphorylase were synthesized for evaluation as potential cancer chemotherapeutic agents. (“Acyclo” = 2′-hydroxymethoxymethyl-). These included a modification of the methylene group at N-1, esters of the terminal hydroxyl of the acyclo group, and extension of the benzyl chain at position 5 of the uracil base. BBBAU was a very good potentiator of FUdR in cell culture.
An improved cathode ray tube storage system

Several years have passed since Williams and Kilburn first described their method of storing digital information as charge patterns on the phosphor screens of common cathode ray tubes.
Explicit fibrant replacement for discrete $G$-spectra

If C is the model category of simplicial presheaves on a site with enough points, with fibrations equal to the global fibrations, then it is well-known that the fibrant objects are, in general, mysterious. Thus, it is not surprising that, when G is a profinite group, the fibrant objects in the model category of discrete G-spectra are also dicult to get a handle on. However, with simplicial presheaves, it is possible to construct an explicit fibrant model for an object in C, under certain finiteness conditions. Similarly, in this paper, we show that if G has finite virtual cohomological dimension and X is a discrete Gspectrum, then there is an explicit fibrant model for X. Also, we give several applications of this concrete model related to closed subgroups of G.
Asymmetric propargylation of ketones using allenylboronates catalyzed by chiral biphenols.

Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3′-Br2-BINOL as the catalyst and allenyldioxoborolane as the nucleophile, in the absence of solvent, and under microwave irradiation to afford the homopropargylic alcohol. The reaction products are obtained in good yields (60 – 98%) and high enantiomeric ratios (3:1 – 99:1). Diastereoselective propargylations using chiral racemic allenylboronates result in good diastereoselectivities (dr > 86:14) and enantioselectivities (er > 92:8) under the catalytic conditions.
A new neural framework for visuospatial processing

The division of cortical visual processing into distinct dorsal and ventral streams is a key framework that has guided visual neuroscience. The characterization of the ventral stream as a 'What' pathway is relatively uncontroversial, but the nature of dorsal stream processing is less clear. Originally proposed as mediating spatial perception ('Where'), more recent accounts suggest it primarily serves non-conscious visually guided action ('How'). Here, we identify three pathways emerging from the dorsal stream that consist of projections to the prefrontal and premotor cortices, and a major projection to the medial temporal lobe that courses both directly and indirectly through the posterior cingulate and retrosplenial cortices. These three pathways support both conscious and non-conscious visuospatial processing, including spatial working memory, visually guided action and navigation, respectively.
Area-Preserving Surface Diffeomorphisms

We prove some generic properties for C r , r = 1,2,. . .,∞, area-preserving diffeomorphism on compact surfaces. The main result is that the union of the stable (or unstable) manifolds of hyperbolic periodic points are dense in the surface. This extends the result of Franks and Le Calvez [10] on S 2 to general surfaces. The proof uses the theory of prime ends and Lefschetz fixed point theorem.
β-Peptides as inhibitors of protein–protein interactions

We became interested several years ago in exploring whether 14-helical β-peptide foldamers could bind protein surfaces and inhibit protein–protein interactions, and if so, whether their affinities and specificities would compare favorably with those of natural or miniature proteins. This exploration was complicated initially by the absence of a suitable β-peptide scaffold, one that possessed a well-defined 14-helical structure in water and tolerated the diverse sequence variation required to generate high-affinity protein surface ligands. In this perspective, we describe our approach to the design of adaptable β-peptide scaffolds with high levels of 14-helix structure in water, track the subsequent development of 14-helical β-peptide protein–protein interaction inhibitors, and examine the potential of this strategy for targeting other therapeutically important proteins.
Dynamic Scaling in Vacancy-Mediated Disordering

We consider the disordering dynamics of an interacting binary alloy with a small admixture of vacancies which mediate atom-atom exchanges. Starting from a perfectly phase-segregated state, the system is rapidly heated to a temperature in the disordered phase. A suitable disorder parameter, namely, the number of broken bonds, is monitored as a function of time. Using Monte Carlo simulations and a coarse-grained field theory, we show that the late stages of this process exhibit dynamic scaling, characterized by a set of scaling functions and exponents. We discuss the universality of these exponents and comment on some subtleties in the early stages of the disordering process.
Symmetry, direct measurement, and Torgerson's conjecture

Abstract Two forms of direct measurement are considered in the article: a strong form in which ratio productions named by number words are interpreted veridically as the numerical ratios they name; and a weak form in which the ratio productions named by number words may have interpretations as ratios that are different from numerical ratios they name. Both forms assume that the responses to instructions to produce ratios are represented numerically by ratios, and thus the word “ratio”—and supposedly the participants concept associated with it—is being “directly” represented. The strong form additionally “directly represents” the number mentioned in the instruction by itself. The article provides an axiomatic theory for the numerical representations produced by both forms. This theory eliminates the need for assuming anything is being “directly represented,” allowing for a purely behavioral approach to ratio production data. It isolates two critical axioms for empirical testing. An measurement-theoretic explanation is provided for the puzzling empirical phenomenon that subjects do not distinguish between ratios and differences in a variety of direct measurement tasks.
An Embodiment of Some Vertebrate Command and Control Principles

Reticular formation of central nervous system in vertebrates described as behavior controlling circuit of interconnected modules, proposing hybrid computer method for operational scheme
Ginsparg-Wilson games

Abstract I implement a set of tricks for constructing lattice fermion actions which approxximately realize the Ginsparg-Wilson relation, with very promising results from simulations.
Structures and Diagrammatics of Four Dimensional Topological Lattice Field Theories

Abstract Crane and Frenkel proposed a state sum invariant for triangulated 4-manifolds. They sketched the definition of a Hopf category that was to be used in their construction. Crane and Yetter studied Hopf categories and gave some examples using group cocycles that are associated to the Drinfeld double of a finite group. In this paper we define a state sum invariant of triangulated 4-manifolds using Crane–Yetter cocycles as Boltzmann weights. Our invariant is analogous to the 3-dimensional invariants defined by Dijkgraaf and Witten and the invariants that are defined via Hopf algebras. We present diagrammatic methods for the study of such invariants that illustrate connections between Hopf categories and moves to triangulations.
Spectral Tetris Fusion Frame Constructions

Spectral tetris is a flexible and elementary method to construct unit norm frames with a given frame operator, having all of its eigenvalues greater than or equal to two. One important application of spectral tetris is the construction of fusion frames. We first show how the assumption on the spectrum of the frame operator can be dropped and extend the spectral tetris algorithm to construct unit norm frames with any given spectrum of the frame operator. We then provide a sufficient condition for using this generalization of spectral tetris to construct fusion frames with prescribed spectrum for the fusion frame operator and with prescribed dimensions for the subspaces. This condition is shown to be necessary in the tight case of redundancy greater than or equal to two.
Soft gamma repeaters

The observational properties of the soft gamma repeaters are reviewed briefly, starting with the time histories and energy spectra of their bursts. The short bursts and giant flares are compared. Their quiescent emission is presented, and the context of the magnetar model is discussed.
A Natural Formalism for Microlensing

If the standard microlensing geometry is inverted so that the Einstein ring is projected onto the observer plane rather than the source plane, then the relations between the observables (θE,E) and the underlying physical quantities (M,πrel) become immediately obvious. Here θE and E are the angular and projected Einstein radii, M is the mass of the lens, and πrel is the lens-source relative parallax. I recast the basic formalism of microlensing in light of this more natural geometry and in terms of observables. I then find that the relations between observable and physical quantities assume an exceptionally simple form. In an appendix, I propose a set of notational conventions.
The measurement of efficiency in life insurance: Estimates of a mixed normal-gamma error model

Abstract This paper make three contributions to the literature on efficiency in financial services. First, it presents estimates of a mixed error cost frontier in which the variances of both the normal and gamma distributions can vary with firm size. Second, it extends the literature on life insurance scale and product mix economies by incorporating and measuring X-inefficiency. Estimates of X-inefficiency range from 35 to 50%; ray scale economies exist up to $15 billion in assets. Third, comparisons of normal-gamma estimates with other methods /3- thick frontier, weighted least squares, half-normal distributions /3- demonstrate some of their pitfalls.
Electrostatic potential analysis of the π regions of some naphthalene derivatives

Abstract We have carried out an electrostatic potential ( V ( r )) analysis of a series of 1-substituted 2,4-dinitronaphthalenes and some related naphthalene and benzene derivatives using an ab initio selfconsistent-field molecular-orbital approach. Our aim was to investigate the nature of V ( r ) above the planes of these systems and possibly to relate it to the formation of π complexes. Negative potentials of varying strengths are observed above the planes of naphthalene and its 1-halo derivatives and are interpreted as being due to the π electrons of the corresponding aromatic rings. The magnitudes of V ( r ) in these regions in the 1-halonaphthalenes decrease in the order 1-fluoro > 1-bromo > 1-chloro, indicating that chlorine is the most effective of these halogens in withdrawing electronic charge from the remainder of the naphthalene molecule. We attribute this trend to two opposing factors: electronegativity, which decreases in the order F > Cl > Br; and charge capacity, which increases in going from fluorine to bromine. The strong electron-withdrawing power of even one nitro group in the naphthalene derivatives suffices to eliminate the negative ring potentials. Positive potential regions are thus observed above the planes of all the nitro containing systems. These show a build up of positive potential above the C-NO 2 bond regions and, in some cases, above the aromatic portion of the molecule. In general, the V ( r ) maxima for the 1-substituted dinitronaphthalenes and trinitrobenzene increase in the same order as do experimentally observed equilibrium constants for the formation of their respective π-complexes with OH − . This is consistent with the interpretation of the potential maxima as reflecting relative susceptibilities for nucleophilic attack.
Preliminary heavy-light decay constants from the MILC collaboration

Preliminary results from the MILC Collaboration for f{sub B}, f{sub B{sub s}}, f{sub D}, f{sub D{sub s}} and their ratios are presented. We compute in the quenched approximation at {beta} = 6.3, 6.0 and 5.7 with Wilson light quarks and static and Wilson heavy quarks. We attempt to quantify all systematic errors other than quenching.
The Abundance of Atomic Sulfur in the Atmosphere of Io

Observations with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope have been used to constrain the atomic sulfur column density in Io's atmosphere. The S I λ1479 dipole allowed and forbidden transition multiplets have been resolved for the first time at Io, enabling the study of both optically thick and thin transitions from a single atomic species. The allowed transitions contribute 62% ± 8% and the forbidden transitions 38% ± 8%, on average, to the total signal of the S I λ1479 multiplets. Using the optically thick and thin transitions of S I λ1479 observed near the limbs of Io, we derive a tangential atmospheric sulfur column abundance of 3.6 × 1012 cm-2 < NS < 1.7 × 1013 cm-2, which is independent of electron temperature and density. A low-density SO2 atmosphere, NSO2 ~ (5–10) × 1015 cm-2, consistent with that inferred from other recent observations, is most consistent with these bounds.
Transesterification of cholesteryl esters

The transesterification of cholesteryl stearate, oleate, linoleate, linolenate and arachidonate to the fatty acid methyl ester and free cholesterol under mild conditions is described. In adaptation of a published procedure the transesterification was carried out for two hr at room temperature in 1N NaOH in methanol:benzene (60:40, v/v). After addition of saturated sodium chloride solution the reaction mixture was extracted with ethyl acetate. The product mixture was checked for cholesterol oxides by HPLC fractionation followed by measurement of the oxides by direct on-column capillary GC. Although transesterification of cholesteryl stearate and oleate was complete (>99%) in 30 min, a uniform reaction period of two hr, required by the polyunsaturated esters, was used for all cholesteryl esters. 7-Ketocholesterol, a principal oxidation product, was unaffected by the reaction conditions.
Fetal magnetic resonance imaging.

Fast magnetic resonance imaging (MRI) has revolutionized our ability to image the fetus. Using fast scanning techniques, individual images are obtained in 300–400 ms, allowing for imaging of the fetus without sedation. MRI is most useful for evaluation of the anomalous fetal central nervous system, for further characterization of complex anomalies not fully elucidated by ultrasound and for evaluation of patients desiring fetal surgery. This review describes the history of fetal MRI, discusses current applications and mentions developments on the horizon.
Aeromedical evacuation of rural victims of nontraumatic cardiac arrest

Study objectives: To determine if the deployment of a helicopter-borne nurse/paramedic team contributed to survival of victims of nontraumatic cardiac arrest in a rural setting. Design: Retrospective chart review. Setting: A university hospital-based helicopter aeromedical program serving a primarily rural region with a volunteer basic life support/advanced life support ground emergency medical services system. Participants: Victims of nontraumatic cardiac arrest, older than 15 years, in cardiac arrest at the time of request for air evacuation. Measurements and main results: Eighty-four patients were identified who met the study inclusion criteria between January 1, 1986, and December 31, 1989. Basic life support care was always available before aeromedical crew arrival; advanced life support care was available in 58% of cases before helicopter arrival. Resuscitative efforts were terminated in the field in 55 cases; of 29 patients transported to the emergency department, only ten (12%) survived to hospital admission. Only one patient (1%) survived to hospital discharge; this patient was resuscitated by ground advanced life support providers before helicopter arrival. Conclusion: Despite providing improved availability of advanced life support care in some cases, deployment of aeromedical teams had a negligible effect on patient survival from nontraumatic cardiac arrest in a rural setting.
Plot of plots and selection glass

Modern dynamic data visualization environments often feature complex displays comprised of many interactive components, such as plots, axes, and others. These components typically contain attributes or properties that can be manipulated programmatically or interactively. Component property manipulation is usually a two-stage process. The user first selects or in some way identifies the component to be revised and then invokes some other technique or procedure to modify the property of interest. Until recently, components typically have been manipulated one at a time, even if the same property is being modified in each component. How to effectively select multiple components interactively in multiple-view displays remains an open issue. This paper proposes modeling the display components with conventional data sets and reusing simple dynamic graphics, such as a scatter plot or a bar chart, as the graphical user interface to select these elements. This simple approach, called plot of plots , provides a uniform, flexible, and powerful scheme to select multiple display components. In addition, another approach called selection glass is also presented. The selection glass is a tool glass with click-on and click-through selection tool widgets for the selection of components. The availability of the plot of plots and selection glass provides a starting point to investigate new techniques to simultaneously modify the same properties on multiple components.
Simulating BPP using a general weak random source

We show how to simulate BPP and approximation algorithms in polynomial time using the output from a δ-source. A δ-source is a weak random source that is asked only once forR bits, and must output anR-bit string according to some distribution that places probability no more than 2−δR on any particular string. We also give an application to the unapproximability of MAX CLIQUE.
Coordination and bargaining over the Gaussian interference channel

This work considers coordination and bargaining between two selfish users over a Gaussian interference channel using game theory. The usual information theoretic approach assumes full cooperation among users for codebook and rate selection. In the scenario investigated here, each selfish user is willing to coordinate its actions only when an incentive exists and benefits of cooperation are fairly allocated. To improve communication rates, the two users are allowed to negotiate for the use of a simple Han-Kobayashi type scheme with fixed power split and conditions for which users have incentives to cooperate are identified. The Nash bargaining solution (NBS) is used as a tool to get fair information rates. The operating point is obtained as a result of an optimization problem and compared with a TDM-based one in the literature.
Low‐Temperature Synthesis Route to MgNb2O6

A solution-derived precursor may be calcined at temperatures >500°C to yield MgNb2O6. Calcining temperatures 800°C result in the familiar, cation-ordered columbite structure type. Calcining temperatures <800°C result in a previously unobserved, cation-disordered α-PbO2 structure type. The low-temperature form of MgNb2O6 is a more reactive material than is obtained by conventional solid-state reaction as evidenced by its small particle size and its ability to react with PbO to form lead magnesium niobate at lower temperatures.
Stress-wave attenuation in thin structures by ultrasonic through-transmission

The steady-state amplitude of the output of an ultrasonic through-transmission measurement is analyzed and the result is given in closed form. Provided that the product of the input and output transduction ratios, the specimen-transducer reflection coefficient, the specimen-transducer phase-shift parameter, and the material phase velocity are known, this analysis gives a means for determining the through-thickness attenuation of an individual thin sample. Multiple stress-wave reflections are taken into account, and so signal echoes do not represent a difficulty. An example is presented for a graphite fiber epoxy composite (Hercules AS/3501-6). Thus, the technique provides a direct method for continuous or intermittent monitoring of through-thickness attenuation of plate structures which may be subject to service structural degradation.
Accuracy of slow-roll inflation given current observational constraints

We investigate the accuracy of slow-roll inflation in light of current observational constraints, which do not allow for a large deviation from scale invariance. We investigate the applicability of the first and second order slow-roll approximations for inflationary models, including those with large running of the scalar spectral index. We compare the full numerical solutions with those given by the first and second order slow-roll formulas. We find that even first order slow roll is generally accurate; the largest deviations arise in models with large running where the error in the power spectrum can be at the level of 1%-2%. Most of this error comes from inaccuracy in the calculation of the slope and not of the running or higher order terms. Second order slow roll does not improve the accuracy over first order. We also argue that in the basis {epsilon}{sub 0}=1/H, {epsilon}{sub n+1}=dln|{epsilon}{sub n}|/dN, introduced by Schwarz et al. (2001), slow roll does not require all of the parameters to be small. For example, even a divergent {epsilon}{sub 3} leads to finite solutions which are accurately described by a slow-roll approximation. Finally, we argue that power spectrum parametrization recently introduced by Abazaijan, Kadota and Stewart does not workmore » for models where spectral index changes from red to blue, while the usual Taylor expansion remains a good approximation.« less
Structural analysis of science prose: can we increase problem-solving performance?

This chapter explores techniques for analyzing the structure and improving the understandability of science prose. Structure refers to a distinction between idea units that explain the mechanisms underlying a rule (explanative information) and idea units that do not (non-explanative information). Understandability is measured by tests of creative problem solving based on information in the passage. Science prose refers to a passage that contains a functional rule among two or more variables and an explanation of the underlying mechanisms. Three techniques are described for distinguishing explanative and non-explanative information: structural method, logical method, and empirical method. Then, research is provided concerning techniques that increase the subject's recall of explanative information, and thus the subject's problem-solving performance. These techniques include manipulating the reading strategy, such as by encouraging reflective or elaborative processing, and manipulating the text design, such as by organizing the text around key ideas or including a concrete model. Finally, some recommendations are suggested for improving science textbooks, with hopes that such recommendations will stimulate further research.
A typology of interdisciplinary education in gerontology and geriatrics: Are we really doing what we say we are?

Gerontology and geriatrics are inherently multidisciplinary fields, incorporating a variety of perspectives, yet little systematic thought has been devoted to exploring the implications of this div...
New Methodology for the Deoxygenative Difluoromethylenation of Aldehydes and Ketones; Unexpected Formation of Tetrafluorocyclopropanes

Generation of difluoromethylene phosphorus ylides in the presence of aldehydes and ketones results in Wittig-type reactions to give gem-difluoroalkenes. Subsequent in situ addition of difluorocarbene (carbenoid) can occur (increased with triphenylphosphine and decreased with tributylphosphine) to give tetrafluorocyclopropanes.
A recursive relation for the determinant of a pentadiagonal matrix

A recursive relation, relating leading principal minors, is developed for the determinant of a pentadiagonal matrix. A numerical example is included to indicate its use in calculating eigenvalues.