cssi/SciSciGPT-SciSciNet huggingface dataset:
Nonlinear interaction of tearing modes: A comparison between the tokamak and the reversed field pinch configurations

The multiple helicity nonlinear interaction of resistive tearing modes is compared for the tokamak and reversed field pinch configurations using the magnetohydrodynamic equations. Unlike the case of the tokamak disruption, for which this interaction is destabilizing when islands overlap, the nonlinear coupling of the dominant helicities is shown to be a stabilizing influence in the reversed field pinch. The behavior of the coupled instabilities in the two configurations can be understood as a consequence of the stability properties of the nonlinearly driven modes. In the case of the tokamak disruption, quasilinear effects linearly destabilize the dominant driven mode, which then feeds energy to the driving mode. For the reversed field pinch the driven modes remain stable, acting as a brake on the growth of the dominant instabilities. Furthermore, for the reversed field pinch configuration, numerical results indicate that nonlinear coupling of different helicities results in noticeably more rapid saturation of the dominant instabilities than was observed in single helicity studies.
Integrating engineering and technical communications in Sophomore electrical engineering projects

Students in engineering courses can learn technical writing skills without having to spend large amounts of valuable class time. Given design-project handouts that contain a problem statement and a list of design specifications, students are asked to solve the problem and they are expected to write a report that includes a title page, abstract, table of contents, introduction, body, conclusion, and reference list. Handouts, which are provided at the beginning of the project, are models of the technical reports the students are expected to prepare.
The value relevance of pension accounting information: evidence from Fortune 200 firms

Purpose – The purpose of this paper is to examine, in the context of movement towards a fair‐value based pension accounting standard, the value relevance of both recognized and disclosed pension accounting information.Design/methodology/approach – Using hand‐collected data from Fortune 200 firms, this study includes both recognized and disclosed pension accounting measures (aggregated and disaggregated) in multivariate regression models. The investigation employs tests of relative and incremental value relevance in both equity and credit rating evaluation contexts.Findings – Findings indicate that pension information recognized under a fair‐value‐based accounting model is no more or less value relevant than pension information recognized under the SFAS 87 model. Also, the disclosed off‐balance sheet pension amount is incrementally value relevant for determining share prices. However, it is not value relevant for the credit rating decision.Research limitations/implications – This study tests the relevance ...
Mechanistic studies of the free-radical fragmentation of monoalkyl diazenes

Abstract Mechanistic studies of the deoxygenation of primary alcohols by Mitsunobu displacement with o -nitrobenzenesulfonylhydrazine (NBSH) reveal that the monoalkyl diazene intermediates formed in this process are exceedingly good hydrogen-atom donors toward alkyl radicals, exceeding tri- n -butyltin hydride in reactivity. Competition experiments are described wherein the radical intermediates are trapped by intra- and intermolecular addition to carbon-carbon double bonds, to dioxygen, and to the free radical 2,2,6,6-tetramethylpiperidine- N -oxyl (TEMPO).
Poverty, Development, and Ecological Services

The importance of ecosystem services to human welfare and economic livelihoods in low-income countries is now well recognized. Poor people in developing regions are particularly vulnerable to the deteriorating ecological values resulting from the loss of tropical forests, coral reefs, mangroves, and other ecosystems. Current efforts to reconcile development pressures with maintaining key ecosystem benefits focus on payment for environmental services and other incentives to protect critical ecosystems and habitat in developing countries. But geographical targeting and other means of tackling poverty more directly should be considered also.
When isomerisation is electron transfer: the intriguing story of the iso-halocarbons

This review examines recent studies of the spectroscopy, dynamics, reactivity and electronic structure of iso-halocarbons, which are isomers of organic halogens that are critically important reactive intermediates in the chemistry of these species. We approach this review from the viewpoint of isomerisation as electron transfer, in as much as the dominant resonance structure of the isomer is an ion pair of halocarbenium ion and halide anion. We show that this perspective is important in understanding the spectroscopy, dynamics and chemical reactivity of the iso-halocarbons. We examine experimental methods for study of the isomer, focusing on the complementary nature of steady state matrix isolation experiments and time-resolved studies, typically carried out in solution. We review experimental data concerning the solvent dependence of the isomer lifetime in solution, examine SN1 style nucleophilic reactions of the isomer with water and related solvents, discuss the role of the isomer as methylene transfer...
Congruences and relations for r-Fishburn numbers

Recently Andrews and Sellers proved some amazing congruences for the Fishburn numbers. We extend their results to a more general sequence of numbers. As a result we prove a new congruence mod 23 for the Fishburn numbers and prove their conjectured mod 5 congruence for a related sequence. We also extend and prove some unpublished conjectures of Garthwaite and Rhoades.
Optical vortex coronagraph

We describe a method to observe dim exoplanets that eliminates light from the parent star across the entire exit pupil without sacrificing light from the planet by use of a vortex mask of topological charge m=2.
Fractional vortex lattice structures in spin triplet superconductors

Motivated by recent interest in spin-triplet superconductors, we investigate the vortex lattice structures for this class of unconventional superconductors. We discuss how the order parameter symmetry can give rise to U(1)×U(1) symmetry in the same sense as in spinor condensates, making half-quantum vortices (HQVs) topologically stable. We then calculate the vortex lattice structure of HQVs, with particular attention on the roles of the crystalline lattice, the Zeeman coupling and Meissner screening, all absent in spinor condensates. Finally, we consider how spin–orbit coupling leads to a breakdown of the U(1)×U(1) symmetry in free energy and whether the HQV lattice survives this symmetry breaking. As examples, we examine simpler spin-triplet models proposed in the context of NaxCoO2·yH2O and Bechgaard salts, as well as the better known and more complex model for Sr2RuO4.
Experimental investigation of coannular jet flow with swirl along a centerbody

An experimental study was conducted in order to investigate the nature of incompressible coannular jet flow with swirl along an unconfined centerbody. Swirl was imparted to the inner stream upstream of the nozzle exit, and the ratio of the outer-to-inner stream mass flow rate ratio was fixed at unity.
Shock-induced volatile loss from a carbonaceous chondrite: implications for planetary accretion

Solid recovery impact-induced volatile loss experiments on the Murchison C2M meteorite indicate that for an impact of a given velocity, H2O and total volatiles are driven from the sample in the same proportion as present initially. The primitive surface volatile budget of a planet growing by accretion would have the same bulk elemental composition as the volatiles in the incident planetesimals. Incipient devolatilization of Murchison occurs at an initial shock pressure of about 11 GPa and complete devolatilization occurs at a pressure of about 30 GPa. For the Earth, incipient and complete devolatilization of accreting planetesimals would occur when the planet reached approximately 12% and 27%, respectively, of its present-day radius. Impact-induced devolatilization would profoundly affect the volatile distribution within the accreting planet. Prior to metallic core formation and internal differentiation the growing planet would have a very small core with the same volatile content as the incident material, a volatile depleted mantle, and an extremely volatile rich surface. In the case of the Earth, 99.4 wt% of the total incident volatile material would end up on or near the planetary surface.
An examination of entry and competitive performance in rural banking markets.

This article explores the change in the level of competition in rural banking markets after the deregulation that occurred following passage of the Riegle-Neal Act of 1994. Using an empirical model that utilizes both the number of banks and the value of deposits in a cross-section of 278 rural markets, we decompose the impact of the entry of new banks into resulting changes in per capita demand and the costs/profits of local banks in 1994 and 2004. The results support the view that local banking markets have become more competitive since the mid-1990s. The 1994 Riegle-Neal Act ushered forth a new era in banking deregulation. As noted by former Federal Reserve Chairman Alan Greenspan in a 2005 speech, deregulation resulted in a 50% decline in the number of banks due to industry consolidation. However, this decline did not necessarily indicate that the level of competition declined; Greenspan (2005) further notes that despite the decline in the number of banks, measures of local market banking competition remained relatively stable between 1990 and 2005. This article explores the nature of competition in rural banking markets over the decade following the 1994 Riegle-Neal Act. Using a recently developed empirical model that utilizes the number of banks as well as the value of deposits in a cross-section of rural markets, we decompose the impact of the entry of new banks into resulting changes in per capita demand and the costs/profits of local banks in 1994 and 2004. The results support Greenspan's claim that banking markets have become more competitive in the 10 years following passage of the Riegle-Neal Act.
Ovarian function in patients receiving adjuvant chemotherapy for breast cancer.

Abstract Plasma œstradiol-plus-oestrone (E 2 +E 1 ), follicle-stimulating hormone (F.S.H.), luteinising hormone (L.H.), androstenedione (A 2 ), and dehydroepiandrosterone sulphate (D.s.) were measured in 33 breast-cancer patients before and after adjuvant chemotherapy. Before treatment the plasma E 2 +E 1 , A 2 , and D.S. levels were significantly higher and the L.H. and F.S.H. lower in the 16 premenopausal patients than in the 17 postmenopausal patients. After 6 mo of adjuvant chemotherapy the premenopausal patients, 11 of whom had become amenorrhœic, showed striking reductions in plasma E 2 +E 1 and A 2 and elevations in plasma L.H. and F.S.H. Further changes were evident after 12 mo of treatment. Plasma-A 2 fell after chemotherapy in the postmenopausal group; the other hormones were unchanged. The beneficial effects of adjuvant chemotherapy for breast cancer may result, in part, from suppression of ovarian function.
Fleet purchase behavior: decision processes and implications for new vehicle technologies and fuels

Vehicle fleets are a poorly understood part of the economy. They are important, though, in that they purchase a large share of light-duty vehicles and are often targeted by governments as agents of change. We investigate fleet purchase behavior, using focus groups, interviews, and mail and telephone surveys. We categorize fleets into four different decision-making structures (autocratic, bureaucratic, hierarchic, and democratic), determine what share of the market sector each represents, describe salient features of each behavioral model, and explore implications of that behavior for industry investment and public policy.
New matter effects in neutrino oscillation experiments

Consequences of a new force mediated by a light scalar particle for neutrino oscillation experiments are considered. Such a force could give rise to neutrino masses and mixings whose matter dependence for earth densities is much more significant than the MSW effect. We consider the effects of such a new force on the limits derived from oscillation experiments, and examine how the constraints on neutrino models are altered. Re-analysis of neutrino data, as well as new experiments in which large matter effects are systematically explored, is required to directly probe such physics beyond the standard model.
Ion-implanted hydrogen in gallium nitride

Abstract Hydrogen was ion-implanted into wurtzite-phase GaN, and its transport, bound states, and microstructural effects during annealing up to 980°C were investigated by nuclear-reaction profiling, ion-channeling analysis, transmission electron microscopy, and infrared (IR) spectroscopy. At implanted concentrations ≳1 at.%, faceted H2 bubbles formed, enabling identification of preferred surfaces, examination of passivating N–H states on these surfaces, and determination of the diffusivity–solubility product of the H. At concentrations below the threshold of bubble formation, H states characterized by N–H bonding and coherence with the host lattice were observed by IR spectroscopy and ion channeling.
The liability equivalence of unfunded nuclear decommissioning costs

Abstract For public health and safety reasons, a nuclear power plant needs to be decommissioned at the end of its useful life. In a recent report, the General Accounting Office (GAO, 1999, p. 16) has called into question the adequacy of funding for decommissioning. In the context of the ongoing deregulation of the electric utility industry, there is considerable uncertainty at this time as to how much of the unfunded decommissioning costs will be recovered from ratepayers. In this study, we utilize alternative current cost and present value estimates of unfunded decommissioning costs to investigate whether investors are cognizant of these potential claims on utility net assets. Our findings are largely consistent with the recent (Financial Accounting Standards Board (2000, ¶ 5) exposure draft which indicates that decommissioning costs should be recognized in the financial statements as a liability. However, the results suggest that unfunded decommissioning obligations have a smaller incremental negative effect on the stock price than other utility liabilities indicating that investors expect partial recovery of these unfunded costs from ratepayers. Given the uncertainty inherent in present value estimates and the uncertainty associated with the future recoverability of unfunded decommissioning costs from ratepayers, additional disclosures may mitigate uncertainty and facilitate investor assessment of these potential obligations.
Extramedullary Plasmacytoma of the Nasopharynx Treated with Surgery and Adjuvant Radiation: Case Report and Review of the Literature

Purpose: Extramedullary plasmacytoma (EMP) is a rare neoplasm of plasma cell origin. Although the head and neck is the most common location of EMP, there are only a handful of cases reported in the nasopharynx. Design: Case report and review of the literature Results: A 50 year-old healthy male presented with a year-long history of increasing bilateral nasal congestion unresponsive to medical therapy. Nasal endoscopy revealed a large exophytic mass filling both posterior nasal cavities. Imaging demonstrated a 3X3 cm mass arising from the nasopharynx and extending into the posterior nasal cavities bilaterally. A biopsy was performed, demonstrating extramedullary plasmacytoma. The patient underwent surgical debulking followed by radiation therapy to the primary site and bilateral necks. He has not recurred to date. Conclusions: Although surgery is usually considered second line treatment for EMP of the head and neck, this case demonstrates the utility of surgical debulking in symptom palliation before definitive treatment with radiation.
Buildup of Magnetic Shear and Free Energy during Flux Emergence and Cancellation

We examine a simulation of flux emergence and cancellation, which shows a complex sequence of processes that accumulate free magnetic energy in the solar corona essential for the eruptive events such as coronal mass ejections, filament eruptions, and flares. The flow velocity at the surface and in the corona shows a consistent shearing pattern along the polarity inversion line (PIL), which together with the rotation of the magnetic polarities, builds up the magnetic shear. Tether-cutting reconnection above the PIL then produces longer sheared magnetic field lines that extend higher into the corona, where a sigmoidal structure forms. Most significantly, reconnection and upward-energy-flux transfer are found to occur even as magnetic flux is submerging and appears to cancel at the photosphere. A comparison of the simulated coronal field with the corresponding coronal potential field graphically shows the development of non-potential fields during the emergence of the magnetic flux and formation of sunspots.
Organic and Organometallic Molecular Magnetic Materials—Designer Magnets

Magnets composed of molecular species or polymers and prepared by relatively low-temperature organic synthetic methodologies are a focus of contemporary materials science research. The anticipated properties of such molecular-species-based magnetic materials, particularly in combination with other properties associated with molecules and polymers, may enable their use in future generations of electronic, magnetic, and/or photonic/photronic devices ranging from information storage and magnetic imaging to static and low-frequency magnetic shielding. A tutorial of typical magnetic behavior of molecular materials is presented. The three distinct models (intramolecular spin coupling through orthogonal orbitals in the same spatial region within a molecule/ion, intermolecular spin coupling through pairwise “configuration interaction” between spin-containing moieties, and dipole—dipole, through-space interactions) which enable the design of new molecular-based magnetic materials are discussed. To achieve the required spin couplings for bulk ferro- or ferrimagnetic behavior it is crucial to prepare materials with the necessary primary, secondary, and tertiary structures akin to proteins. Selected results from the worldwide effort aimed at preparing molecular-based magnetic materials by these mechanisms are described. Some organometallic solids comprised of linear chains of alternating metallocenium donors (D) and cyanocarbon acceptors (A) that is, …D•+ A•− D•+ A•−…, exhibit cooperative magnetic phenomena. Bulk ferromagnetic behavior was first observed below the critical (Curie) temperature Tc of 4.8 K for [FeIII(C5Me5)2]•+ [TCNE]•− (Me = methyl; TCNE = tetracyanoethylene). Replacement of FeIII with MnIII leads to a ferromagnet with a Tc of 8.8 K in agreement with mean-field models developed for this class of materials. Replacement with CrIII, however, leads to a ferromagnet with a Tc lowered to 3.65 K which is at variance with this model. Extension to the reaction of a vanadium(o) complex with TCNE leads to the isolation of a magnet with a Tc ≈ 400 K, which exceeds the thermal decomposition temperature of the material. This demonstrates that a magnetic material with a Tc substantially above room temperature is achievable in a molecule/organic/polymeric material. Finally, a new class of one-dimensional ferrimagnetic materials based on metalloporphins is discussed.
Effect of Out-of-Roundness on the Performance of a Diesel Engine Connecting-Rod Bearing

In this paper, the dynamic performance of the Ruston and Hornsby VEB diesel engine connecting-rod bearing with circular and out-of-round profiles is analyzed. The effect of cavitation is considered by using a cavitation algorithm, which mimics JFO boundary conditions. The effect of mass inertia is accounted for by solving coupled nonlinear equations of motion. The journal profiles considered are circular, elliptical, semi-elliptical, and three lobe epicycloid. The predicted journal trajectory and other performance parameters for one complete load cycle are presented for all of the out-of-round profiles and are also compared with the predictions for the circular bearing.
Radiologic Evaluation of Penile Arterial Anatomy in Arteriogenic Impotence

Functional and anatomic evaluation of penile arterial blood flow is essential in the work up of erectile dysfunction. Duplex ultrasonography is an ideal screening modality with cavernosal mean peak systolic blood flow velocity being the most sensitive predictor of arterial disease. Arterial variability of the penis may affect sonographic evaluation leading to frequent misinterpretation and therefore pudendal arteriography remains the current gold standard for penile arterial evaluation. Appreciation of the type and frequency of anatomic variants and potential collateral routes is important in interpreting penile arteriograms and in evaluating the hemodynamic significance of suspected arterial disease.
Approximating loops in a shortest homology basis from point data

Inference of topological and geometric attributes of a hidden manifold from its point data is a fundamental problem arising in many scientific studies and engineering applications. In this paper we present an algorithm to compute a set of loops from a point data that presumably sample a smooth manifold M ⊂ Rd. These loops approximate a shortest basis of the one dimensional homology group H1(M) over coefficients in finite field Z2. Previous results addressed the issue of computing the rank of the homology groups from point data, but there is no result on approximating the shortest basis of a manifold from its point sample. In arriving our result, we also present a polynomial time algorithm for computing a shortest basis of H1 (Κ) for any finite simplicial complex Κ whose edges have non-negative weights.
Dual roles for PARP1 during heat shock: transcriptional activator and posttranscriptional inhibitor of gene expression.

In this issue of Molecular Cell, Di Giammartino et al. (2012) identify a new function for PARP1 in the post-transcriptional regulation of mRNAs via ADP-ribosylation of poly(A) polymerase, a mRNA 3′ processing enzyme.
Performance testing of medical echo/Doppler equipment.

This paper describes the methods applied in a software package developed by the authors for use in a performance testing protocol for medical ultrasound equipment. The history of performance testing of medical ultrasound equipment is briefly reviewed. This paper is confined to the testing of performance of usage aspects, i.e. imaging performance and Doppler velocity estimation performance. Simple test objects are used which have a long life expectancy. The tests performed both in fundamental and in (tissue) harmonic modes when applicable are spatial resolution, contrast sensitivity, and clutter. The concept of a computational observer is used to define the lesion signal-to-noise ratio and the tissue-to-clutter ratio. Further imaging performance features are penetration depth, slice thickness and geometric conformity of display. Pulsed Doppler velocity measurement features tested are: sensitivity, depth and 3D size of the sample volume, velocity measurement, channel separation. The whole performance measurement protocol as well as the quantitative measurements in the digitized images are implemented in software, together with the graphs and data obtained from the measurements.
Monophasic Catalytic System for the Selective Semireduction of Alkynes

A highly efficient semireduction of alkynes has been developed. Using 0.5–2 mol % of a copper catalyst, semireduction can be accomplished with a wide range of substrates, including both internal and terminal alkynes without over-reduction. The new method has excellent chemoselectivity, and the semireduction can be accomplished even in the presence of nitro and aryl iodo groups. Finally, commercial availability of a catalyst precursor adds to the appeal of the new catalytic system.
Bounds on the lightest Higgs boson mass with three and four fermion generations

We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations, SM(3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and four generations, MSSM(3,4). Our analysis utilizes the SM(3,4) renormalization-group-improved one-loop effective potential of the Higgs boson to find the upper bounds on the Higgs mass in the MSSM(3,4), while the lower bounds in the SM(3,4) are derived from considerations of vacuum stability. All the bounds increase as the degenerate fourth generation mass increases, providing more room in theory space that respects the increasing experimental lower limit of the Higgs mass.
“ACQUIRED” ADRENAL HYPERPLASIA WITH 21-HYDROXYLASE DEFICIENCY IS NOT THE SAME GENETIC DISORDER AS CONGENITAL ADRENAL HYPERPLASIA

Abstract Hormonal studies and HLA genotyping were performed on the family of a patient with “acquired” adrenal hyperplasia (AAH) due to 21-hydroxylase deficiency. The results of these studies suggest that “AAH”, is not the same genetic disease as CAH.
3D heliospheric simulations of cosmic rays in the light of Ulysses.

Recent Ulysses observations in the polar regions of the heliosphere have provided fundamental new insights into the modes of cosmic-ray transport in the heliosphere. Ulysses discovered variations in the magnetic field which are large enough to produce significant cosmic-ray effects, and which are consistent with a previous prediction. In addition to impeding the inward, radial diffusive and drift access of cosmic rays over the poles as discussed previously, the magnetic fluctuations imply a significantly larger latitudinal diffusion. These effects directly lead to both a much reduced latitudinal gradient and significant 27-day time variations near the pole. We conclude that the general picture of cosmic-ray transport and modulation developed over the past decade, with reasonable parameters, can account for most of the observed global, large-scale phenomena.
Symmetrical multilevel diversity coding with an all-access encoder

Symmetrical Multilevel Diversity Coding (SMDC) is a network compression problem introduced by Roche (1992) and Yeung (1995). This paper considers a generalization of SMDC for which, in addition to the randomly accessible encoders, there is also an all-access encoder. It is shown that a simple separate coding strategy known as superposition coding is optimal in terms of achieving the entire admissible rate region of the problem. Key to our proof is to identify the supporting hyperplanes that define the boundary of the admissible rate region and then builds on the result of Yeung and Zhang on a generalization of Han's subset inequality.
Molecular behavior in small spaces.

The study of physical organic chemistry in solution is a mature science, over a century old, but over the last 10 years or so, reversible encapsulation has changed the way researchers view molecular interactions. It is now clear that the behavior of molecules in dilute solution is really quite different from their behavior in capsules. Molecules isolated from bulk media in spaces barely large enough to accommodate them and a few neighbors show new phenomena: their activities resemble those of molecules inside biochemical structures—pockets of enzymes, interiors of chaperones, or the inner space of the ribosome—rather than conventional behavior in solution. In this Account, we recount the behavior of molecules in these small spaces with emphasis on structures and reactivities that have not been, and perhaps cannot be, seen in conventional solution chemistry. The capsules self-assemble through a variety of forces, including hydrogen bonds, metal−ligand interactions, and hydrophobic effects. Their lifetimes ...
Addition of diphenylphosphine to Michael-type olefins: the preparation of phosphine-nitrile and phosphine-ester ligands

Abstract The reactions of five Michael-type olefins with diphenylphosphine have been carried out. 1-Cyanocyclopentene, 1-cyanocyclohexene, and 4-t-butyl-1-cyanocyclohexene all provide the corresponding 2-diphenylphosphino-1-cyanocycloalkanes, and both methyl acrylate and ethyl methacrylate yield the corresponding 2-diphenylphosphinopropionates. For the products from 1-cyanocyclopentene and 1-cyanocyclohexene, 13C and 31P NMR data are consistent with the formation of both trans (Ph2P equatorial and CN axial) and cis (both Ph2P and CN equatorial) isomers. The morpholine amide of 3-diphenylphosphinopropionic acid has been obtained by treatment of methyl-3-diphenylphosphinopropionate with the dimethylaluminum adduct of morpholine. This phosphine, Ph2Pmorph, has been isolated as its palladium(II) complex, (Ph2Pmorph)2PdCl2. A phosphine-benzaldimine, Ph2P(CH2)3NC(H)C6H5, has been obtained by reacting Ph2P(CH2)3NH2, from the reduction of PhP(CH2)2CN, with benzaldehyde in the presence of molecular sieves.
Dark-matter in gravity-mediated supersymmetry breaking

Abstract In R parity conserving supersymmetric theories, the lightest superpartner (LSP) is stable. The LSPs may comprise a large fraction of the energy density of the current universe, which would lead to dramatic astrophysical consequences. In this talk, I will discuss some of the main points we have learned about supersymmetric models from relic abundance considerations of the LSP.
Reflecting on the history of astronomy education research to plan for the future

Abstract Despite astronomy’s widespread inclusion in curricula prior to the 20th century, educational research in astronomy is a relatively new endeavor. To date there are no dedicated paper journals for astronomy education research, although the electronic Astronomy Education Review (http:// aer.noao.edu ) has recently released its first issue. As the field of astronomy education research grows, many may find it useful to know what has been done so far. The new SABER database represents an ongoing, collaborative attempt for the astronomy education community to collect and summarize the highly dispersed literature on astronomy education research, although it is not yet complete. Starting with and expanding beyond this database, a systematic review and classification of the literature was performed. Some of the research themes that emerged include: student beliefs and misconceptions; collaborative learning; and the Astronomy Diagnostic Test. Key studies in these areas are described and a bibliography is presented.
Observations on the Burning of Droplets in the Absence of Buoyancy

Experimental results are reported on the burning of free droplets of heptane and decane in oxygen-nitrogen atmospheres. The burning occurred in a freely falling chamber providing 2.2 sec of negligible gravity. Enhanced burning rates and a phenomenon of flash extinction were observed and attributed to thermophoretic buildup and ignition of carbon near the droplet surface.
Anodic cyclization reactions: the total synthesis of alliacol a.

An anodic cyclization−Friedel Crafts alkylation strategy has been used to rapidly assemble the core ring system of alliacol A and to complete a formal total synthesis of the natural product. The anodic cyclization reaction was used to effect the coupling of a nucleophilic furan ring to the normally nucleophilic carbon of a silyl enol ether. The substrate for this initial cyclization reaction contained all of the carbons needed for completing the total synthesis. The electrolysis proceeded in high yield and could be accomplished with the use of a 6 V lantern battery.
Applying dispersive changes to Lagrangian particles in groundwater transport models.

Method-of-characteristics groundwater transport models require that changes in concentrations computed within an Eulerian framework to account for dispersion be transferred to moving particles used to simulate advective transport. A new algorithm was developed to accomplish this transfer between nodal values and advecting particles more precisely and realistically compared to currently used methods. The new method scales the changes and adjustments of particle concentrations relative to limiting bounds of concentration values determined from the population of adjacent nodal values. The method precludes unrealistic undershoot or overshoot for concentrations of individual particles. In the new method, if dispersion causes cell concentrations to decrease during a time step, those particles in the cell having the highest concentration will decrease the most, and those with the lowest concentration will decrease the least. The converse is true if dispersion is causing concentrations to increase. Furthermore, if the initial concentration on a particle is outside the range of the adjacent nodal values, it will automatically be adjusted in the direction of the acceptable range of values. The new method is inherently mass conservative.
A class of quadrature-based moment-closure methods with application to the Vlasov-Poisson-Fokker-Planck system in the high-field limit

Quadrature-based moment-closure methods are a class of approximations that replace high-dimensional kinetic descriptions with lower-dimensional fluid models. In this work we investigate some of the properties of a sub-class of these methods based on bi-delta, bi-Gaussian, and bi-B-spline representations. We develop a high-order discontinuous Galerkin (DG) scheme to solve the resulting fluid systems. Finally, via this high-order DG scheme and Strang operator splitting to handle the collision term, we simulate the fluid-closure models in the context of the Vlasov-Poisson-Fokker-Planck system in the high-field limit. We demonstrate numerically that the proposed scheme is asymptotic-preserving in the high-field limit.
Mapping properties of analytic functions on the disk

. There is a universal constant 0 0 so that the Euclidean area, counting multiplicity, of the portion of f(D) which lies over the disk D(f(0), M), centered at f(0) and of radius M, is strictly less than the area of D(f(0), M). Then f must send r 0 D into D(f(0),M). This answers a conjecture of Don Marshall.
The multi-way relay channel

The multi-user communication channel, in which multiple users exchange information with the help of a single relay terminal, called the multi-way relay channel, is considered. In this model, multiple interfering clusters of users communicate simultaneously, where the users within the same cluster wish to exchange messages among themselves. It is assumed that the users cannot receive each other's signals directly, and hence the relay terminal is the enabler of communication. A relevant metric to study in this scenario is the symmetric rate achievable by all users, which we identify for amplify-and-forward (AF), decode-and-forward (DF) and compress-and-forward (CF) protocols. We also present an upper bound for comparison. The two extreme cases, namely full data exchange, in which every user wants to receive messages of all other users, and pairwise data exchange, consisting of multiple two-way relay channels, are investigated and presented in detail.
Usoi Dam Wave Overtopping and Flood Routing in the Bartang and Panj Rivers, Tajikistan

The Usoi dam was created in the winter of 1911 after an enormous seismogenic rock slide completely blocked the valley of the Bartang River in the Pamir Mountains of southeastern Tajikistan. At present the dam impounds 17 million cubic meters of water in Lake Sarez. Flood volume and discharge estimates were made for several landslide generated floods that could overtop the dam. For landslide volumes of 200, 500, and 1,000 million cubic meters, estimated overtopping flood volumes were 2, 22, and 87 million cubic meters of water, respectively. Estimated peak discharge at the dam for these three flood scenarios were 57,000, 490,000, and 1,580,000 m3/s, based on triangular hydrographs of 70-, 90-, and 110-s durations, respectively. Flood-routing simulations were made for the three landslide-induced overtopping floods over a 530-km reach of the Bartang and Panj Rivers below the Usoi dam. A one-dimensional flow model using a Riemann numerical solution technique was selected for the analysis. For the 87 million cubic meter volume overtopping flood scenario, the peak flows were approximately 1, 100, 800, and 550 m3/s at locations 50, 100, and 150 km downstream of the dam respectively.
A new technique for accurately measuring two-phase relative permeability under non-Darcy flow conditions

Abstract A new steady-state technique for determining gas–water relative permeability curves for proppant packs under high confining stress conditions is presented. In this technique, a time domain reflectometry (TDR) device that can measure the saturation inside the proppant pack instantly and efficiently is introduced. De-aired water and nitrogen gas are simultaneously injected into the proppant pack under a desired confining stress, and the pressure drop and saturation are measured when steady-state conditions are reached. Two different proppant mesh sizes, 12/18 and 20/40, have been tested under four confining stresses ranging from 1000 to 4000 psi with repeatable and accurate results. In the majority of published techniques, two-phase relative permeability curves are determined by using Darcy׳s law. This might be accurate enough for low permeability formations under low flow rate conditions, but in high permeability fracture proppant packs, the non-Darcy flow effects, or inertial effects, cannot be neglected. Thus relative permeability curves neglecting inertial effects may lead to inaccurate predictions. In this paper, three flow models: the classic generalized Darcy׳s Law, the generalized Forchheimer flow model, and the two-phase Barree and Conway model ( Barree and Conway, 2007 ) are employed to calculate and compare the relative permeability results. The experimental results show that the non-Darcy flow effects on gas relative permeability are higher than those calculated using Darcy׳s Law. In addition, the various confining stress effects on water and gas relative permeability curves are also presented. A significant decrease in gas relative permeability and minor effects on water relative permeability occur as the confining stress increases. These results help to further understand the effects of multiphase flow in porous media.
Concurrent games with tail objectives

We study infinite stochastic games played by two players over a finite state space, with objectives specified by sets of infinite traces. The games are concurrent (players make moves simultaneously and independently), stochastic (the next state is determined by a probability distribution that depends on the current state and chosen moves of the players) and infinite (proceed for an infinite number of rounds). The analysis of concurrent stochastic games can be classified into: quantitative analysis, analyzing the optimum value of the game and @e-optimal strategies that ensure values within @e of the optimum value; and qualitative analysis, analyzing the set of states with optimum value 1 and @e-optimal strategies for the states with optimum value 1. We consider concurrent games with tail objectives, i.e., objectives that are independent of the finite-prefix of traces, and show that the class of tail objectives is strictly richer than that of the @w-regular objectives. We develop new proof techniques to extend several properties of concurrent games with @w-regular objectives to concurrent games with tail objectives. We prove the positive limit-one property for tail objectives. The positive limit-one property states that for all concurrent games if the optimum value for a player is positive for a tail objective @F at some state, then there is a state where the optimum value is 1 for the player for the objective @F. We also show that the optimum values of zero-sum (strictly conflicting objectives) games with tail objectives can be related to equilibrium values of nonzero-sum (not strictly conflicting objectives) games with simpler reachability objectives. A consequence of our analysis presents a polynomial time reduction of the quantitative analysis of tail objectives to the qualitative analysis for the subclass of one-player stochastic games (Markov decision processes).
Experiments with a symbolic evaluation system

Symbolic evaluation techniques can be used to determine the cumulative effects of a program's calculations on the branching predicates and output variables in the program. If the evaluation techniques are carefully and selectively applied, they can be used to generate revealing symbolic representations of the computations carried out by the paths in a program, and of the systems of predicates that describe the input data that causes program paths to be executed. A symbolic evaluation system called DISSECT is described which can be used to analyze FORTRAN programs. The system includes a sophisticated command language that allows the user to selectively apply symbolic evaluation techniques to different program paths and subpaths. The command language allows the user to carry out different levels of symbolic testing of a program and to construct systems of predicates that can be used to automate the generation of numeric test data. Experiments with the system which illustrate its advantages and limitations are included. DISSECT can be used to carry out a systematic, documented reliability analysis of a program. The paper concludes with a discussion of the potential use of systems like DISSECT as the basic software certification tool in the software development process.
Nothing for branes

Recent work on closed string tachyon condensation suggests the existence of a 'nothing state' where closed strings and space itself vanish. We consider the evolution of D-branes in such condensation processes, focusing on what happens in the condensate itself. We find evidence that the branes exist in the region; although, generically their apparent mass grows exponentially with time. However, there exist specific branes whose boundary state is unaltered by the tachyon.
The prospects for constraining dark energy with future X-ray cluster gas mass fraction measurements

A B ST R A C T W eexam inetheability ofafutureX-rayobservatory,with capabilitiessim ilartothose plannedfortheConstellation-X orX-rayEvolvingUniverseSpectroscopy(XEUS)m is- sions,to constrain dark energy via m easurem entsofthe clusterX-ray gasm assfrac- tion, fgas.W end that fgas m easurem entsfora sam ple of � 500 hot(kT & 5keV), X-ray bright,dynam ically relaxed clusters,to a precision of � 5 percent,can beused toconstrain darkenergywith aDarkEnergyTask Force(DETF;Albrechtetal.2006) �gureofm eritof15 40,with thepossibility ofboosting thesevaluesby 40 percent or m ore by optim izing the redshift distribution oftarget clusters.Such constraints are com parable to those predicted by the DETF for other leading,planned 'Stage IV'dark energy experim ents.A future fgas experim ent willbe preceded by a large X-ray orSZ survey thatwillnd hot,X-ray lum inousclustersoutto high redshifts. Short'snapshot'observationswith thenew X-ray observatory should then beableto identify a sam ple of � 500 suitably relaxed system s.The redshift,tem perature and X-ray lum inosity rangeofinteresthasalready been partially probed by existingX-ray clustersurveyswhich allow reasonable estim atesofthe fraction ofclustersthatwill besuitably relaxed for fgas work to bem ade;thesesurveysalso show thatX-rayux contam ination from pointsourcesislikely to be sm allforthem ajority ofthetargets ofinterest.Ouranalysisusesa M arkov Chain M onte Carlo m ethod which fully cap- turesthe relevantdegeneraciesbetween param etersand facilitatesthe incorporation ofpriorsand system atic uncertaintiesin the analysis.W e explore the eectsofsuch uncertaintiesfor scenariosranging from optim istic to pessim istic.W e conclude that the fgas experim ent oers a com petitive and com plem entary approach to the best otherlarge,planned dark energy experim ents.In particular,the fgas experim entwill providetightconstraintson the m ean m atterand dark energy densities,with a peak sensitivity fordark energy work atredshiftsm idway between thoseofsupernovaeand baryon acousticoscillation/weak lensing/clusternum bercountsexperim ents.In com - bination,these experim entsshould enable a precise m easurem entofthe evolution of dark energy. K ey w ords: cosm ology:observations{ cosm ology:cosm ologicalparam eters{ cosm ol- ogy:theory { x-ray clusters{ dark energy
Assessing Systemic Risk Exposure from Banks and GSEs Under Alternative Approaches to Capital Regulation

A key function of capital regulation is to mitigate the potential for systemic financial risk by maintaining public confidence in the ability of regulated market participants to honor their financial obligations in times of market stress. While it is well known that the portfolios of banks and non-banks, especially those intermediaries specializing in mortgage securitization or in specialized mortgage lending, differ in important respects, debate over alternative capital regulations has yet to recognize the implications of these differences, despite the increasing importance of non-bank intermediaries in risk-sharing markets. This paper uses a simple two-date discrete state space exchange economy with opportunities for moral hazard on the part of financial intermediaries to investigate the design of capital regulations to control systemic risk. Holding constant asset risks, we show that intermediaries that issue contingent liabilities may exhibit low or no risk of insolvency while holding significantly less capital than deposit-taking institutions because banks primarily issue claims that promise fixed payments in all states of nature. We also show that, rather than raising capital requirements, the control of systemic risk may involve lowering capital requirements and extending guarantees to liability-holders, without a necessary increase in expected subsidy payments, if such requirements account for shareholder incentives. Specifically, we analyze an example of regulatory policy in which lower capital requirements and an ex post penalty schedule reduce systemic risk by increasing the volume of tradable securities exchanged and by offering a credible mechanism by which intermediaries can signal the true riskiness of their portfolios to liability-holders.
The Supply Side of the Digital Divide: Is There Equal Availability in the Broadband Internet Access Market?

The newest dimension of the digital divide is access to broadband (high-speed) Internet service. Using comprehensive U.S. data covering all forms of access technology (chiefly DSL and cable modem), I look for evidence of unequal broadband availability in areas with high concentrations of poor, minority, or rural households. There is little evidence of unequal availability based on income or on black or Hispanic concentration. There is mixed evidence concerning availability based on Native American or Asian concentration. Other findings: Rural location decreases availability; market size, education, Spanish language use, commuting distance, and Bell presence increase availability.
Three-Dimensional Quantitative Structure-Permeability Relationship Analysis for a Series of Inhibitors of Rhinovirus Replication

Multiple three-dimensional quantitative structure−activity relationship (3D-QSAR) approaches were applied to predicting passive Caco-2 permeability for a series of 28 inhibitors of rhinovirus replication. Catalyst, genetic function approximation (GFA) with MS-WHIM descriptors, CoMFA, and VolSurf were all used for generating 3D-quantitative structure permeability relationships utilizing a training set of 19 molecules. Each of these approaches was then compared using a test set of nine molecules not present in the training set. Statistical parameters for the test set predictions (r2 and leave-one-out q2) were used to compare the models. It was found that the Catalyst pharmacophore model was the most predictive (test set of predicted versus observed permeability, r2 = 0.94). This model consisted of a hydrogen bond acceptor, hydrogen bond donor, and ring aromatic feature with a training set correlation of r2 = 0.83. The CoMFA model consisted of three components with an r2 value of 0.96 and produced good predi...