cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of high intensity sound on electrical conduction in muscle

Studies carried out on the curarized, excised biceps muscle of the hind leg of frog (Rana Pipiens) demonstrate that under appropriate ultrasonic dosage (frequency of one megacycle) the action potential response of the muscle can be permanently reduced or completely blocked. This can be accomplished in the absence of a temperature level sufficient in itself to cause permanent suppression. Quantitative determination of the minimum dosage curve (reciprocal of exposure time vs acoustic pressure amplitude) required for a ten percent reduction of the action potential indicates that the shape of this curve is the same as the curve given by Fry for paralysis of the hind legs of frogs irradiated in the lumbar enlargement region of the spinal cord. Histological examination of stained tissue sections shows no gross tearing or vacuolization. Probe measurements made within the muscle also indicate that cavitation is absent.
Prebiotic organic synthesis under hydrothermal conditions: an overview

Abstract Organic compounds which are obviously synthesized from inorganic precursors (e.g., CO) by hydrothermal activity are currently a research topic in prebiotic chemistry leading to the origin of life. However, such de novo products would be overwhelmed in present Earth environments, by an excess of thermal alteration (pyrolysis) products formed from contemporary life (e.g., hydrocarbons, alkanoic acids, etc.). Thus, organic syntheses must be demonstrated and distinguished from organic matter alteration initially in the laboratory and then in the field. Organic synthesis under hydrothermal conditions is theoretically possible and various established industrial processes are used to synthesize organic compounds from inorganic substrates with the aid of catalysts. A set of Strecker-type synthesis experiments has been carried out under hydrothermal conditions (150 °C), producing various amino acids. The formation of lipid compounds during an aqueous organic synthesis (Fischer–Tropsch-type) reaction was reported, using solutions of oxalic acid (also formic acid) as the carbon and hydrogen sources, and heating at discrete temperatures (50° intervals) from 100 to 400 °C. The maximum lipid yield, especially for oxygenated compounds was in the window of 150–250 °C. The compounds range from C6 to >C33, including n-alkanols, n-alkanoic acids, n-alkyl formates, n-alkanones, and n-alkanes, all with no carbon number preferences. These lipid compounds, especially the acids, can form lipid bilayers or micelles, potential precursors for membranes. Reductive condensation (i.e., dehydration) reactions also occur under simulated hydrothermal conditions and form amide, nitrile and ester bonds. The chemistry and kinetics of the condensation reactions are under further study and have the potential for oligomerization of acid-amides in aqueous medium. Abiotic organic compounds are not biomarkers per se because they do not originate from biosynthesis. Thus, they should be regarded as a distinctly separate group, termed prebiotic or synthetic organic compounds, in explorations for evidence of life.
Computer Aided Manual Validation of Mass Spectrometry-based Proteomic Data

Advances in mass spectrometry-based proteomic technologies have increased the speed of analysis and the depth provided by a single analysis. Computational tools to evaluate the accuracy of peptide identifications from these high-throughput analyses have not kept pace with technological advances; currently the most common quality evaluation methods are based on statistical analysis of the likelihood of false positive identifications in large-scale data sets. While helpful, these calculations do not consider the accuracy of each identification, thus creating a precarious situation for biologists relying on the data to inform experimental design. Manual validation is the gold standard approach to confirm accuracy of database identifications, but is extremely time-intensive. To palliate the increasing time required to manually validate large proteomic datasets, we provide computer aided manual validation software (CAMV) to expedite the process. Relevant spectra are collected, catalogued, and pre-labeled, allowing users to efficiently judge the quality of each identification and summarize applicable quantitative information. CAMV significantly reduces the burden associated with manual validation and will hopefully encourage broader adoption of manual validation in mass spectrometry-based proteomics.
Low-energy effective theory in the bulk for transport in a topological phase

We construct a low-energy effective action for a two-dimensional nonrelativistic topological (i.e., gapped) phase of matter in a continuum, which completely describes all of its bulk electrical, thermal, and stress-related properties in the limit of low frequencies, long distances, and zero temperature, without assuming either Lorentz or Galilean invariance. This is done by generalizing Luttinger's approach to thermoelectric phenomena, via the introduction of a background vielbein (i.e., gravitational) field and spin connection a la Cartan, in addition to the electromagnetic vector potential, in the action for the microscopic degrees of freedom (the matter fields). Crucially, the geometry of spacetime is allowed to have timelike and spacelike torsion. These background fields make all natural invariances—under U(1) gauge transformations, translations in both space and time, and spatial rotations—appear locally, and corresponding conserved currents and the stress tensor can be obtained, which obey natural continuity equations. On integrating out the matter fields, we derive the most general form of a local bulk induced action to first order in derivatives of the background fields, from which thermodynamic and transport properties can be obtained. We show that the gapped bulk cannot contribute to low-temperature thermoelectric transport other than the ordinary Hall conductivity; the other thermoelectric effects (if they occur) are thus purely edge effects. The coupling to “reduced” spacelike torsion is found to be absent in minimally coupled models, and, using a generalized Belinfante stress tensor, the stress response to time-dependent vielbeins (i.e., strains) is the Hall viscosity, which is robust against perturbations and related to the spin current, as in earlier work.
The return of the Heliospheric 2-3 kHz radio emission during solar cycle 23

In this paper we report the detection of a new heliospheric 2–3 kHz radio emission event by the Voyager 1 spacecraft, the first to be observed during solar cycle 23. The new event started on Nov. 1, 2002, and is believed to be associated with a strong interplanetary shock that originated from a period of intense solar activity in early April 2001. Following previous interpretations of events of this type, we assume that the radio emission is produced when the interplanetary shock interacted with the heliopause, which is the boundary between the solar wind and the interplanetary medium. From the onset time of the radio emission and a simple model for the propagation speed of the interplanetary shock, the heliocentric radial distance to the nose of the heliopause can be calculated, and is about 153 to 158 AU, depending on the parameters used. From computer simulations that give the ratio of the radial distance to the termination shock to the radial distance to the heliopause, the distance to the termination shock can also be calculated and is estimated to be about 101 to 108 AU.
NASA/FAA General Aviation Crash Dynamics Program - A Status Report

The objective of the Langley Research Center general aviation crash dynamics program is to develop technology for improved crash safety and occupant survivability in general aviation aircraft. The program involves three basic areas of research: controlled full-scale crash testing, nonlinear structural analyses to predict large deflection elasto-plastic response, and load attenuating concepts for use in improved seat and subfloor structure. Both analytical and experimental methods are used to develop expertise in these areas. Analyses include simplified procedures for estimating energy dissipating capabilities and complex computerized procedures for predicting airframe response. These analyses are being developed to provide designers with methods for predicting accelerations, loads, and displacements of collapsing structure. Tests on typical full-scale aircraft and on full- and sub-scale structural components are being performed to verify the analyses and to demonstrate load attenuating concepts.
Eleven-dimensional origin of string-string duality: A One loop test

Abstract Membrane/ fivebrane duality in D = 11 implies Type IIA string/Type IIA fivebrane duality in D = 10, which in turn implies Type HA string/heterotic string duality in D = 6. To test the conjecture, we reproduce the corrections to the 3-form field equations of the D = 10 Type IIA string (a mixture of tree-level and one-loop effects) starting from the Chern-Simons corrections to the 7-form Bianchi identities of the D = 11 fivebrane (a purely tree-level effect). K3 compactification of the latter then yields the familiar gauge and Lorentz Chem-Simons corrections to 3-form Bianchi identities of the heterotic string. We note that the absence of a dilaton in the D = 11 theory allows us to fix both the gravitational constant and the fivebrane tension in terms of the membrane tension. We also comment on an apparent conflict between fundamental and solitonic heterotic strings and on the puzzle of a fivebrane origin of S -duality.
Non vanishing loci of Hodge numbers of local systems

We show that closures of families of unitary local systems on quasiprojective varieties for which the dimension of a graded component of Hodge filtration has a constant value can be identified with a finite union of polytopes. We also present a local version of this theorem. This yields the “Hodge decomposition” of the set of unitary local systems with a non-vanishing cohomology extending Hodge decomposition of characteristic varieties of links of plane curves studied by the author earlier. We consider a twisted version of the characteristic varieties generalizing the twisted Alexander polynomials. Several explicit calculations for complements to arrangements are made.
College performance predictions and the SAT

The methods used in most SAT validity studies cannot be justified by any sample selection assumptions and are uninformative about the source of the SAT's predictive power. A new omitted variables estimator is proposed; plausibly consistent estimates of the SAT's contribution to predictions of University of California freshman grade point averages are about 20% smaller than the usual methods imply. Moreover, much of the SAT's predictive power is found to derive from its correlation with high school demographic characteristics: The orthogonal portion of SAT scores is notably less predictive of future performance than is the unadjusted score.
Ruthenium- and palladium-catalyzed enyne cycloisomerizations: differentially stereoselective syntheses of bicyclic structures.

Enyne cycloisomerizations can provide an efficient means for forming carbon−carbon bonds. We describe stereoselectively dichotomous enyne cycloisomerizations, entirely dependent on the selection of catalytic manifold. Ruthenium catalysis provides trans-fused bicyclic systems, whereas palladium catalysis provides the analogous cis-fused bicycles. A number of substrates are investigated, and the outcomes ultimately offer a clear mechanistic rationale for these observations.
Baryons containing a heavy quark as solitons

The possibility of interpreting baryons containing a single heavy quark as bound states of solitons (that arise in the non-linear sigma model) and heavy mesons is explored. Particular attention is paid to the parity of the bound states and to the role of heavy quark symmetry.
Testing the halo model against the SDSS photometric survey

We present halo model predictions for the expected angular clustering and associated errors from the completed Sloan Digital Sky Survey (SDSS) photometric galaxy sample. These results are used to constrain halo model parameters under the assumption of a fixed ACDM cosmology using standard Fisher matrix techniques. Given the ability of the five-colour SDSS photometry to separate galaxies into subpopulations by intrinsic colour, we also use extensions of the standard halo model formalism to calculate the expected clustering of red and blue galaxy subpopulations as a further test of the galaxy evolution included in the semi-analytical methods for populating dark matter haloes with galaxies. The extremely small sample variance and Poisson errors from the completed SDSS should result in very impressive constraints (∼1-10 per cent) on the halo model parameters for a simple magnitude-limited sample and should provide an extremely useful check on the behaviour of current and future N-body simulations and semi-analytical techniques. We also show that similar constraints are possible using a narrow selection function, as would be possible using photometric redshifts, without making linear assumptions regarding the evolution of the underlying power spectra. In both cases, we explore the effects of uncertainty in the selection function on the resulting constraints and the degeneracies between various combinations of parameters.
Double Dipping in Environmental Markets

Abstract There is an increasing tendency to use markets to induce the provision of environmental services. As such markets increase in scope, potential market participants might sell multiple environmental services. The question we consider here is whether participants in such markets should be allowed to sell credits in more than one market simultaneously. Some have argued in favor of such “double-dipping”, because it would make the provision of environmental services more profitable. In practice however, most programs do not allow double-dipping. We show that if the optimal level of pollution abatement is sought, then double-dipping maximizes societal net benefits. However, if pollution policies are set in a piecemeal fashion, then the caps for each market are unlikely to be optimal and, in this second-best setting, a policy prohibiting double-dipping can lead to greater social net benefits. We explore conditions under which a single-market policy is preferred, or equivalently, where piecemeal policies are likely to yield particularly inefficient outcomes.
A Detailed Thermal Analysis of the Binospec Spectrograph

Refractive optics in astronomical instruments are potentially sensitive to temperature gradients and temperature transients. This sensitivity arises from thermally dependent refractive indices, lens spacings, and lens dimensions. In addition, thermal gradients in the instrument structure can cause undesirable image shifts at the detector that degrade instrument calibration. We have therefore undertaken a detailed thermal analysis of Binospec, a wide-field optical spectrograph under development for the converted Multiple Mirror Telescope (MMT). Our goals are to predict the temperature gradients that will be present in the Binospec optics and structure under realistic operating conditions and to determine how design choices affect these gradients. We begin our analysis by deriving thermal time constants for instrument subassemblies to estimate the magnitude of temperature gradients in the instrument and to determine where detailed thermal models are required. We then generate a low-resolution finite-difference model of the entire instrument and high-resolution models of sensitive subassemblies. This approach to thermal analysis is applicable to a variety of other instruments. We use measurements of the ambient temperature in the converted MMT's dome to model Binospec's thermal environment. In moderate conditions, the external temperature changes by up to 8C over 48 hr, while in extreme conditions the external temperature changes by up to 17C in 24 hr. During moderate conditions, we find that the Binospec lens groups develop ∼0.14C axial and radial temperature gradients and that lens groups of different mass develop ∼0.5C temperature differences; these numbers are doubled for the extreme conditions. Internal heat sources do not significantly affect these results; heat flow from the environment dominates. The instrument must be periodically opened to insert new aperture masks, but we find that the resulting temperature gradients and thermal stresses in the optics are small. Image shifts at the detector caused by thermal deflections of the Binospec optical bench structure are ∼0.1 pixel hr . We conclude that the proposed Binospec design has acceptable 1
On Galilean invariance and nonlinearity in electrodynamics and quantum mechanics

Abstract Recent experimental results such as those on slow light heighten interest in nonlinear Maxwell theories. We obtain Galilei covariant equations for electromagnetism by allowing special nonlinearities in the constitutive equations only, keeping Maxwell's equations unchanged. Combining these with linear or nonlinear Schrodinger equations, e.g., as proposed by Doebner and Goldin, yields a consistent, nonlinear, Galilean Schrodinger–Maxwell electrodynamics.
Discovery of the First Methanol (CH3OH) Maser in the Andromeda Galaxy (M31)

We present the first detection of a 6.7 GHz Class II methanol (CH3OH) maser in the Andromeda galaxy (M31). The CH3OH maser was found in a VLA survey during the fall of 2009. We have confirmed the methanol maser with the new EVLA, in operation since 2010 March, but were unsuccessful in detecting a water maser at this location. A direct application for this methanol maser is the determination of the proper motion of M31, such as was previously obtained with water masers in M33 and IC10. Unraveling the three-dimensional velocity of M31 would solve for the biggest unknown in the modeling of the dynamics and evolution of the Local Group of galaxies.
Aerodynamics of formation flight

Reported are the results of wind-tunnel tests conducted to evaluate aerodynamics characteristics of aircraft in formation flight. A vortex-lattice numerical scheme was used to investigate the effect of spatial offset (horizontal and vertical) between the leading and trailing wings. The wind-tunnel test configurations consisted of echelon, chevron, and in-line formations. Analysis of the data revealed that the spatial offset and the angle of attack of the leading wing had significant impact on the trailing aircraft. For some test conditions an increase in lift-to-drag ratio of the trailing aircraft was measured. Variation in C Lmax and/or α stall was observed as well. At higher angles of attack of the leading wing, the C L-α curve of the trailing aircraft was significantly altered.
Collective tree spanners of graphs

In this paper we introduce a new notion of collective tree spanners. We say that a graph G=(V,E)admits a system of $\mu$ collective additive tree r-spanners if there is a system T(G) of at most $\mu$ spanning trees of G such that for any two vertices x,y of G a spanning tree T\in \cT(G) exists such that d_T(x,y)\leq d_G(x,y)+r. Among other results, we show that any chordal graph, chordal bipartite graph or cocomparability graph admits a system of at most log2n collective additive tree 2-spanners. These results are complemented by lower bounds, which say that any system of collective additive tree 1-spanners must have $\Omega(\sqrt{n})$ spanning trees for some chordal graphs and $\Omega(n)$ spanning trees for some chordal bipartite graphs and some cocomparability graphs. Furthermore, we show that any c-chordal graph admits a system of at most log2n collective additive tree (2\lfloor c/2\rfloor)-spanners, any circular-arc graph admits a system of two collective additive tree 2-spanners. Towards establishing these results, we present a general property for graphs, called (\al,r)$-decomposition, and show that any $(\al,r)$-decomposable graph $G$ with $n$ vertices admits a system of at most $\log_{1/\al} n$ collective additive tree $2r$-spanners. We discuss also an application of the collective tree spanners to the problem of designing compact and efficient routing schemes in graphs. For any graph on n vertices admitting a system of at most $\mu$ collective additive tree r-spanners, there is a routing scheme of deviation r with addresses and routing tables of size $O(\mu \log^2n/\log \log n)$ bits per vertex. This leads, for example, to a routing scheme of deviation $(2\lfloor c/2\rfloor)$ with addresses and routing tables of size $O(\log^3n/\log \log n)$ bits per vertex on the class of c-chordal graphs.
Medical Malpractice Reform Measures and Their Effects

New rules and methods for medical injury dispute resolution have been launched in New Hampshire and New York, and demonstration projects are underway elsewhere. This article describes major medical malpractice reforms undertaken and proposed in recent years. Reforms are classified as (1) liability-limiting initiatives favoring health-care providers; (2) procedural innovations promoted as improving dispute resolution processes, such as patient compensation funds, "sorry" laws, disclosure and early offer laws, health courts, and safe harbor laws; and (3) major conceptual reforms to move liability away from physicians to hospitals or administrative no-fault compensation systems. Empirical evidence about the practical effects of already-implemented reforms, such as damage caps, is reviewed. In light of declining malpractice claim rates, heavier adverse impacts of damage caps on vulnerable groups (people who have severe injuries, who are elderly, and who are unemployed) and repeated findings of state law unconstitutionality, the rationale for nationwide damage caps is questioned. Attention to innovative reform proposals such as patient compensation funds, disclosure and early offer laws, safe harbor laws, enterprise insurance and no-fault compensation systems, is encouraged.
Lessons from patents: Using patents to measure technological change in environmental models

Abstract When studying solutions to long-term environmental problems such as climate change, it is important to consider the role that technological change may play. Nonetheless, to date few economic models of environmental policy explicitly model the link between policy and technological change. There is a growing body of evidence that the incentives offered by prices and environmental regulations have a strong influence on both the creation and adoption of new technologies. In several recent papers, I have used patent data to examine the links between environmental policy and technological change. In addition, I have used the results of this research to calibrate the ENTICE model (for ENdogenous Technological change) of climate change, which links energy-related R&D to changes in the price of carbon. Drawing on my experiences from empirical studies on innovation and from modeling the climate change problem, in this paper I review some of the key lessons from recent empirical work using patents to study environmental innovation and diffusion, and discuss its implications for modeling climate change policy. I conclude by offering suggestions for future research.
A Meshless Finite Difference Method for Conjugate Heat Conduction Problems

A meshless finite difference method is developed for solving conjugate heat transfer problems. Starting with an arbitrary distribution of mesh points, derivatives are evaluated using a weighted least-squares procedure. The resulting system of algebraic equations is sparse and is solved using an algebraic multigrid method. The implementation of the Neumann, Dirichlet, and mixed boundary conditions within this framework is described. For conjugate heat transfer problems, continuity of the heat flux and temperature are imposed on mesh points at multimaterial interfaces. The method is verified through application to classical heat conduction problems with known analytical solutions. It is then applied to the solution of conjugate heat transfer problems in complex geometries, and the solutions so obtained are compared with more conventional unstructured finite volume methods. The method improves on existing meshless methods for conjugate heat conduction by eliminating spurious oscillations previously observed. Metrics for accuracy are provided and future extensions are discussed.
The moon as a high temperature condensate

The accretion during condensation mechanism, if it occurs during the early over-luminous stage of the Sun, can explain the differences in composition of the terrestrial planets and the Moon. An important factor is the variation of pressure and temperature with distance from the Sun, and in the case of the Moon and captured satellites of other planets, with distance from the median plane. Current estimates of the temperature and pressure in the solar nebula suggest that condensation will not be complete in the vicinity of the terrestrial planets, and that depending on location, iron, magnesium silicates and the volatiles will be at least partially held in the gaseous phase and subject to separation from the dust by solar wind and magnetic effects associated with the transfer of angular momentum just before the Sun joins the Main Sequence.
Magnetic Photon Splitting: Computations of Proper-Time Rates and Spectra

The splitting of photons γ → γγ in the presence of an intense magnetic field has recently found astrophysical applications in polar cap models of γ-ray pulsars and in "magnetar" (i.e., neutron stars with extremely high fields) scenarios for soft gamma repeaters. Numerical computation of the polarization-dependent rates of this third-order QED process for arbitrary field strengths and energies below pair creation threshold is difficult; thus, early analyses focused on analytic developments and simpler asymptotic forms. The recent astrophysical interest spurred the use of the S-matrix approach by Mentzel, Berg, and Wunner to determine splitting rates. In this paper, we present numerical computations of a full proper-time expression for the rate of splitting that was obtained by Stoneham and is exact up to the pair creation threshold. While the numerical results derived here are in accord with the earlier asymptotic forms that are due to Adler, our computed rates still differ by as much as a factor of 3 from the S-matrix reevaluation of Wilke and Wunner, reflecting the extreme difficulty of generating accurate S-matrix numerics for fields below about 4.4 × 1013 G. We find that our proper-time rates appear to be very accurate and exceed Adler's asymptotic specializations significantly only for photon energies just below pair threshold and for supercritical fields, but always by less than a factor of ~2.6. We also provide a useful analytic series expansion for the scattering amplitude valid at low energies.
Notes on the bulk viscosity of holographic gauge theory plasmas

A novel technique is used to compute the bulk viscosity of high temperature holographic gauge theory plasmas with softly broken conformal symmetry. Working in a black hole background which corresponds to a non-trivial solution to the Navier-Stokes equation, and using a Ward identity for the trace of the stress-energy tensor, it is possible to obtain an analytic expression for the bulk viscosity. This can be used to verify the high temperature limit of a conjectured bound on the bulk viscosity for these theories. The bound is saturated when the conformal symmetry-breaking operator becomes marginal.
Social Network Analysis: A case study of the Islamist terrorist network

Social Network Analysis is a compilation of methods used to identify and analyze patterns in social network systems. This article serves as a primer on foundational social network concepts and analyses and builds a case study on the global Islamist terrorist network to illustrate the use and usefulness of these methods. The Islamist terrorist network is a system composed of multiple terrorist organizations that are socially connected and work toward the same goals. This research utilizes traditional social network, as well as small-world, and scale-free analyses to characterize this system on individual, network and systemic levels. Leaders in the network are identified based on their positions in the social network and the network structure is categorized. Finally, two vital nodes in the network are removed and this version of the network is compared with the previous version to make implications of strengths, weaknesses and vulnerabilities. The Islamist terrorist network structure is found to be a resilient and efficient structure, even with important social nodes removed. Implications for counterterrorism are given from the results of each analysis.
International Public Goods and Agency Problems in Treaty Organizations

This paper analyzes the extent to which international public goods and agency problems are present in international organizations. A noncooperative model of the funding choices of donor countries and the subsequent policy choices of an international agency is used to develop hypotheses about the behavior of ideal and problematic international agencies. The analysis suggests that international agencies are likely to be underfunded and undermonitored relative to that which maximizes the joint interest of signatory countries. The funding and policy implications of the model are tested using data from the Global Environment Facility (GEF). The statistical results suggest that (i) treaty obligations affect behavior of Annex 1 and non-Annex 1 countries, (ii) GEF’s allocation of grants generally advances the international environmental agenda, and (iii) significant free-riding and agency problems exist in GEF as it is presently organized. Overall, the empirical results suggest that treaty organizations may be relatively effective, if not perfect, instruments of international public policy.
The Treatment of Posterior Compartment Vaginal Defects

Posterior compartment prolapse can be thought of as a relaxation or separation of the tissues of the rectovaginal septum and perineal body. This article reviews the pathophysiology, diagnosis, and surgical management of rectoceles and relaxed vaginal outlet. With proper treatment, a continued active lifestyle and improved quality of life usually can be restored; however, this result requires a thorough understanding of pelvic anatomy and pathophysiology and experience in performing the appropriate surgical procedures.
Young core collapse supernova remnants and their supernovae

Massive star supernovae can be divided into four categories, depending on the amount of mass loss from the progenitor star and the star's radius: red supergiant stars with most of the H envelope intact (SN IIP), stars with some H but most lost (IIL and IIb), stars with all H lost (Ib and Ic), and blue supergiant stars with a massive H envelope (SN 1987A-like). Various aspects of the immediate aftermath of the supernova are expected to develop in different ways, depending on the supernova category: mixing in the supernova, fallback on the central compact object, expansion of any pulsar wind nebula, interaction with circumstellar matter, and photoionization by shock breakout radiation. The observed properties of young supernova remnants allow many of them to be placed in one of the supernova categories; all the categories are represented except for the SN 1987A-like type. Of the remnants with central pulsars, the pulsar properties do not appear to be related to the supernova category. There is no evidence that the supernova categories form a mass sequence, as would be expected in a single-star scenario for the evolution. Models for young pulsar wind nebulae expanding into supernova ejecta indicate initial pulsar periods of 10-100 ms and approximate equipartition between particle and magnetic energies. Ages are obtained for pulsar nebulae, including an age of 2400 ± 500 yr for 3C 58, which is not consistent with an origin in SN 1181. There is no evidence that mass fallback plays a role in neutron star properties.
Blind Network Revenue Management

We consider a general class of network revenue management problems, where mean demand at each point in time is determined by a vector of prices, and the objective is to dynamically adjust these prices so as to maximize expected revenues over a finite sales horizon. A salient feature of our problem is that the decision maker can only observe realized demand over time but does not know the underlying demand function that maps prices into instantaneous demand rate. We introduce a family of “blind” pricing policies that are designed to balance trade-offs between exploration demand learning and exploitation pricing to optimize revenues. We derive bounds on the revenue loss incurred by said policies in comparison to the optimal dynamic pricing policy that knows the demand function a priori, and we prove that asymptotically, as the volume of sales increases, this gap shrinks to zero.
Parameter Variation-An Insight to V/STOL Design

Dimensional stability derivatives gathered from a simulator during the development of the XV-4B aircraft have been varied one and two at a time in a computer program for extracting the roots of the lateral-directional characteristic equation. These roots have been used to provide complex plane plots indicating the effect of derivative variation on the dynamic characteristics of the vehicle. Secondary plots have been used to show the breakdown of the elements making up each derivative. The sources for these elements and factors affecting their prediction have been examined, along with changes required to modify the vehicle's dynamic characteristics. Some comparisons are made with other vehicles.
Power Engineering Education and the Internet: Motivation and Instructional Tools

Alternatives in the application of the Internet are applied to power engineering education. Because the student perception of power engineering is often that this is an old technology, new ways to effectively present the challenges, and the opportunities as well, are needed. The Internet and innovative graphic and textural materials are suggested to effectively present the case for power engineering as a valuable career. This is suggested to build on student interest in these computer technologies. The contents of web sites for this purpose are described, and the educational pedagogy of the method is discussed.
Why was Asia Resilient? Lessons from the Past and for the Future

Asia proved to be remarkably resilient in the face of the global financial crisis, but why was its output performance stronger than that of other regions? The paper shows that better initial conditions — in the form of lower external and financial vulnerabilities — contributed significantly to Asia's resilience. Key pre-crisis factors included moderate credit expansion, reliance on deposit funding, enhanced bank asset quality, reduced external financing, and improved current accounts. These improvements reflected the lessons from the Asian financial crisis in the late 1990s, which helped to reshape both public policies and private sector behavior. Looking ahead, Asia is in the process of adjusting to more volatile external conditions and higher risk premiums. By drawing the right lessons from its pre-crisis experiences, Asia's economies will be better equipped to address new risks associated with increased cross-border capital flows and greater integration with the rest of the world.
Rapid Access to Chroman-3-ones through Gold-Catalyzed Oxidation of Propargyl Aryl Ethers

Only two steps? Chroman-3-ones are important intermediates for organic synthesis and medicinal chemistry. However, their syntheses require multiple steps and are not efficient. By using gold-catalyzed alkyne oxidation, this versatile heterocycle can be prepared in only two steps from readily available phenols and with mostly high efficiencies.
Conversion of Some Siloxane Polymers to Silicon Oxide by UV/Ozone Photochemical Processes

A variety of linear and cross-linked polysiloxanes are transformed into silicon oxide (SiOx) through the application of a recently developed room-temperature UV/ozone conversion process. Ozone and atomic oxygen, produced by exposure of atmospheric oxygen to ultraviolet radiation, remove organic portions of the polymers as volatile products and leave a thin silicon oxide surface film. The conversion rates differ for each polysiloxane studied and are related to differences in their chemical structures. X-ray photoelectron spectroscopy (XPS) measurements of atomic ratios indicate that UV/ozone treatment removes up to 89% of the carbon from the resultant surface film, leading to an overall stoichiometry close to that of SiO2. The binding energy of Si(2p) core level photoelectrons shifts from 101.5 eV for the polymer precursors to about 103.5 eV after UV exposure, consistent with the formation of silicon that is coordinated to four oxygen atoms. Ellipsometry measurements of apparent thickness changes during co...
A Note on the Unsteady Cavity Flow in a Tunnel

The unsteady internal cavitating flow such as the one observed in a pump or a turbine is studied for a simple two-dimensional model of a base-cavitating wedge in an infinite tunnel and it is shown how the cavitation compliance can be calculated using the linearized free streamline theory. Numerical values are obtained for the limiting case of a free jet. Two important features are: First, the cavitation compliance is found to be of complex form, having additional resistive and reactive terms beyond the purely inertial oscillation of the whole channel in "slug flow." Second, the compliance has a strong dependence on frequency.
Modes of growth in dynamic systems

Regardless of a system's complexity or scale, its growth can be considered to be a spontaneous thermodynamic response to a local convergence of down-gradient material flows. Here it is shown how sy...
Distance measures for reduced ordering-based vector filters

Reduced ordering-based vector filters have proved successful in removing long-tailed noise from colour images while preserving edges and fine image details. These filters commonly utilise variants of the Minkowski distance to order the colour vectors with the aim of distinguishing between noisy and noise-free vectors. In this study, the authors review various alternative distance measures and evaluate their performance on a large and diverse set of images using several effectiveness and efficiency criteria. The results demonstrate that there are in fact strong alternatives to the popular Minkowski metrics.
Distribution of Eigenvalues of Highly Palindromic Toeplitz Matrices

Consider the ensemble of real symmetric Toeplitz matrices whose entries are i.i.d. random variables chosen from a fixed probability distribution p of mean 0, variance 1, and finite higher moments. Previous work (Bryc et al., Ann. Probab. 34(1):1–38, 2006; Hammond and Miller, J. Theor. Probab. 18(3):537–566, 2005) showed that the spectral measures (the density of normalized eigenvalues) converge almost surely to a universal distribution almost that of the Gaussian, independent of p. The deficit from the Gaussian distribution is due to obstructions to solutions of Diophantine equations and can be removed (see Massey et al., J. Theor. Probab. 20(3):637–662, 2007) by making the first row palindromic. In this paper we study the case where there is more than one palindrome in the first row of real symmetric Toeplitz matrices. Using the method of moments and an analysis of the resulting Diophantine equations, we show that the spectral measures converge almost surely to a universal distribution. Assuming a conjecture on the resulting Diophantine sums (which is supported by numerics and some theoretical arguments), we prove that the limiting distribution has a fatter tail than any previously seen limiting spectral measure.
A practical buchwald-hartwig amination of 2-bromopyridines with volatile amines

A practical Buchwald-Hartwig amination of 2-bromopyridines with volatile amines is developed in sealed tubes. The method provides an expedient entry to a variety of secondary and tertiary aminopyridines that are otherwise not readily synthesized.
THRESHOLD COINTEGRATION AND NONLINEAR ADJUSTMENT TO THE LAW OF ONE PRICE

Previous studies investigating threshold behavior in real-exchange-rate and price difference data have used rather ad hoc statistical methods and have focused on univariate threshold models for relative prices. We utilize a general multivariate threshold cointegration model and develop a systematic testing and estimation strategy for this model, building on the work of others. Using Monte Carlo experiments, we systematically compare the use of univariate and multivariate techniques for testing threshold cointegration, estimating various threshold models, and testing specifications. We apply our methodology to a large set of U.S. disaggregated CPI data. We find evidence of threshold cointegration mainly for tradable goods. However, the type of threshold nonlinearity that we find generally does not support the transaction-cost view of commodity arbitrage.
Comparison with a standard via fully sequential procedures

We develop fully sequential procedures for comparison with a standard. The goal is to find systems whose expected performance measures are larger or smaller than a single system referred to as a standard and, if there is any, to find the one with the largest or smallest performance. The general formulation of comparison with a standard gives the standard a special status and tries to protect it when its performance is better than or even equal to performance measures of all the other alternatives. Therefore, the problem cannot be formulated as the selection of the best and a specialized procedure is required. Our procedures allow for unequal variances across systems, the use of common random numbers, and known or unknown expected performance of the standard. Experimental results are provided to compare the efficiency of the procedure with other existing procedures.
Hierarchical assembly may be a way to make large information-rich structures

Self-assembly in the laboratory can now yield ‘information-rich’ nanostructures in which each component is of a distinct type and has a defined spatial position. Ensuring the thermodynamic stability of such structures requires inter-component interaction energies to increase logarithmically with structure size, in order to counter the entropy gained upon mixing component types in solution. However, self-assembly in the presence of strong interactions results in general in kinetic trapping, so suggesting a limit to the size of an (equilibrium) structure that can be self-assembled from distinguishable components. Here we study numerically a two-dimensional hierarchical assembly scheme already considered in experiment. We show that this scheme is immune to the kinetic traps associated with strong ‘native’ interactions (interactions designed to stabilize the intended structure), and so, in principle, offers a way to make large information-rich structures. In this scheme the size of an assembled structure scales exponentially with the stage of assembly, and assembly can continue as long as random motion is able to bring structures into contact. The resulting superstructure could provide a template for building in the third dimension. The chief drawback of this scheme is that it is particularly susceptible to kinetic traps that result from ‘non-native’ interactions (interactions not required to stabilize the intended structure); the scale on which such a scheme can be realized therefore depends upon how effectively this latter kind of interaction can be suppressed.
Biphenyl‐Derived Phosphepines as Chiral Nucleophilic Catalysts: Enantioselective [4+1] Annulations To Form Functionalized Cyclopentenes

Because of the frequent occurrence of cyclopentane subunits in bioactive compounds, the development of efficient catalytic asymmetric methods for their synthesis is an important objective. Introduced herein is a new family of chiral nucleophilic catalysts, biphenyl-derived phosphepines, and we apply them to an enantioselective variant of a useful [4+1] annulation. A range of one-carbon coupling partners can be employed, thereby generating cyclopentenes which bear a fully substituted stereocenter [either all-carbon or heteroatom-substituted (sulfur and phosphorus)]. Stereocenters at the other four positions of the cyclopentane ring can also be introduced with good stereoselectivity. An initial mechanistic study indicates that phosphine addition to the electrophilic four-carbon coupling partner is not the turnover-limiting step of the catalytic cycle.
The Loop Group of E8 and Targets for Spacetime

The dimensional reduction of the E8 gauge theory in 11 dimensions leads to a loop bundle in ten-dimensional type IIA string theory. We show that the restriction to the Neveu–Schwarz sector leads naturally to a sigma model with target space E8 with the ten-dimensional spacetime as the source. The corresponding bundle has a structure group: the group of based loops, whose classifying space we study. We explore some consequences of this proposal such as possible Lagrangians and existence of flat connections.
Collective action and individual choice: rethinking how we regulate narcotics and antibiotics

Governments across the globe have squandered treasure and imprisoned millions of their own citizens by criminalising the use and sale of recreational drugs. But use of these drugs has remained relatively constant, and the primary victims are the users themselves. Meanwhile, antimicrobial drugs that once had the power to cure infections are losing their ability to do so, compromising the health of people around the world. The thesis of this essay is that policymakers should stop wasting resources trying to fight an unwinnable and morally dubious war against recreational drug users, and start shifting their attention to the serious threat posed by our collective misuse of antibiotics.
Electronic and thermoelectric properties of CoSbS and FeSbS

We present a combined theoretical and experimental study of the potential thermoelectric performance of three transition metal antimonide sulfides, CoSbS, FeSbS, and NiSbS. From theory we find that NiSbS is metallic and hence of little interest regarding thermoelectric performance. CoSbS and FeSbS are both semiconductors with rather heavy valence and conduction bands, whose thermopower can exceed 200 $\ensuremath{\mu}$V/K at temperatures of 900 K and carrier concentrations of 10${}^{21}$cm${}^{\ensuremath{-}3}$, which is similar to the $n$-type high performance thermoelectric filled skutterudites. The experimental results on several non-optimized $n$-type CoSbS samples confirm its semiconducting nature and indicate a potential for good high temperature thermoelectric performance, finding a $ZT$ for two of the samples of 0.35 at 773 K. Substantially higher $ZT$ values may be possible if the lattice thermal conductivity can be reduced by alloying and the effects of extrinsic scattering, which appear to be substantial in the experimental results, are reduced.
Econometric Issues in Education Finance

Several econometric issues within the field of education finance that have not been fully explored to date are addressed. Focusing on demographic factors and per-pupil expenditures in the United States, an econometric model that incorporates spatial analysis is developed and a unique framework for analyzing the impact of demographics on local public demand is introduced. The results show that ethnic diversity has a negative impact on per-pupil spending, while the elderly have a positive impact.
Allocation of initial public offerings and flipping activity

Abstract There is a general perception that the large trading volume in initial public offerings is mostly due to “flippers” that are allocated shares in the offering and immediately resell them. On average, however, flipping accounts for only 19% of trading volume and 15% of shares offered during the first two days of trading. Institutions do more flipping than retail customers and hot IPOs are flipped much more than cold IPOs. Institutions do not quickly flip cold IPOs to take advantage of price support activities by the underwriter. Explicit penalty bids are rarely assessed against flippers.