cssi/SciSciGPT-SciSciNet huggingface dataset:
Towards an optimal reconstruction of baryon oscillations

The Baryon Acoustic Oscillations (BAO) in the large-scale structure of the universe leave a distinct peak in the two-point correlation function of the matter distribution. That acoustic peak is smeared and shifted by bulk flows and non-linear evolution. However, it has been shown that it is still possible to sharpen the peak and remove its shift by undoing the effects of the bulk flows. We propose an improvement to the standard acoustic peak reconstruction. Contrary to the standard approach, the new scheme has no free parameters, treats the large-scale modes consistently, and uses optimal filters to extract the BAO information. At redshift of zero, the reconstructed linear matter power spectrum leads to a markedly improved sharpening of the reconstructed acoustic peak compared to standard reconstruction.
Aircraft Design with Active Load Alleviation and Natural Laminar Flow

Maneuver load alleviation, gust load alleviation, and natural laminar flow are integrated into aircraft conceptual design. The concurrent design of the aircraft and its active load alleviation systems can yield significant gains. The simultaneous application of maneuver load alleviation and gust load alleviation to a short-haul aircraft leads to an 11% reduction in fuel burn and 7% reduction in direct operating cost. These savings are diminished if maneuver load alleviation and gust load alleviation are applied independently. The synergy between active load control and natural laminar flow is also explored. It is possible to invest some of the weight savings from load alleviation to achieve extensive laminar flow. The combination of load alleviation and natural laminar flow increases the fuel and cost savings to upwards of 18 and 11%, respectively. It is concluded that load alleviation can shift the transonic transport optimum toward low-sweep, natural laminar flow wings. Sensitivity studies finally demon...
Global Properties of Well-Behaved Demand Systems: A Generalized Logit Model Specification

Abstract Global negative semidefiniteness of the Hicks-Slutsky substitution matrix limits the range of the elasticities with respect to own-price (Eii), cross-price (Eii) and expenditure or income (EiI) for many standard demand systems. In a two-good model, the results for the translog and AIDS are qualitatively identical, namely, Eii is less than -1; Eii is greater than 0; and EiI equals 1 (homothetic preferences). The results for the generalized Leontief and minflex Laurent are also qualitatively identifical, namely, Eii is equal to the negative of the own expenditure share; Eij is equal to the negative of the expenditure share' of the other good; and EiI equals 1 (homothetic preferences and zero Hicksian substitutability). Thus, these standard flexible functional forms can be globally well behaved but at the expense of losing their flexibility property. The generalized logit model presented in this paper is also a flexible functional form and can be globally well behaved while retaining flexibility.
Reversible Electrowetting of Liquid-Metal Droplet

This paper reports experimental investigations on the electrowetting effect of liquid metals, e.g., mercury, on dielectric films. Largest contact angle change of 74 deg (from 141 deg to 67 deg) is achieved on top of a Parylene film. Highly reversible electrowetting with very low hysteresis (2-4 deg) is demonstrated on the Teflon@-coated surfaces. The actuation voltage for 30 deg contact angle change (from 148 deg to 118 deg) is largely reduced to 25 V by using a high-dielectric-constant tantalum oxide film as the dielectric layer. The effect of trapped charges in the dielectric film on the electrowetting is observed and measured. The rise and fall times of the electrowetting actuation are inversely proportional to the droplet diameter and as short as 0.1-0.2 ms for a 50 μm dia droplet. The actuation reliability is tested, and a long-time operation is achieved in an oil environment.
Recognizing moving faces: A psychological and neural synthesis

Information for identifying a human face can be found both in the invariant structure of features and in idiosyncratic movements and gestures. When both kinds of information are available, psychological evidence indicates that: (1) dynamic information contributes more to recognition under non-optimal viewing conditions, e.g. poor illumination, low image resolution, recognition from a distance; (2) dynamic information contributes more as a viewer's experience with the face increases; and (3) a structure-from-motion analysis can make a perceptually based contribution to face recognition. A recently proposed distributed neural system for face perception, with minor modifications, can accommodate the psychological findings with moving faces.
Asymmetric palladium-catalyzed carboamination reactions for the synthesis of enantiomerically enriched 2-(arylmethyl)- and 2-(alkenylmethyl)pyrrolidines.

The enantioselective synthesis of 2-(arylmethyl)- and 2-(alkenylmethyl)pyrrolidine derivatives via Pd-catalyzed alkene carboamination reactions is described. These transformations generate enantiomerically enriched products with up to 94% ee from readily available alkenyl or aryl bromides and N-boc-pent-4-enylamines. The application of this method to a concise asymmetric synthesis of (−)-tylophorine is also discussed.
Large-Format Ebsicon For Low Light Level Satellite Surveillance

"Ebsicon" is the generic name for any camera tube which contains a photoelectron-bombarded silicon diode array target. Following a description of the motivation for and the development of a large-format ebsicon (one containing an 80 mm photocathode and a 32 mm silicon target), the features of the device are presented. Emphasis is placed on the point-source performance of the tube in terms of the achieved point-source image cell density and the point-source response fall-off away from the center of the scanned area. Photocathode requirements are discussed in the context of the expected per-formance of the Air Force's upcoming Ground-based Electro-Optical Deep Space Surveillance (GEODSS) system. Then, field measurements for exposure times of 0.6 and 1/30 second, using G-type stars, are described and compared to the projected performance of a GEODSS electro-optical sensor. Finally, a list is presented of additional, important, and measured features of delivered, large-format ebsicons.
Experimental Investigation of Convective Melting of Granular Packed Bed Under Microgravity

To improve the understanding of convective melting of packed solid particles in a fluid, an experimental investigation is conducted to study the melting characteristics of a packed bed by unmasking the buoyancy forces due to the density difference between the melt and solid particles. A close-loop apparatus, named the particle-melting-in-flow (PMF) module, is designed to allow a steady-state liquid flow at a specified temperature. The module is installed onboard NASA's KC-135 reduced gravity aircraft using ice particles of desired sizes and water as the test media. Experimentally determined melting rates are presented as a function of upstream flow velocity, temperature and initial average particle size of the packed bed
High minor ion outflow speeds in the inner corona and observed ion charge states in interplanetary space

The study carried out in order to demonstrate that high minor ion outflow speeds of the order of O(5+) outflow speed are consistent with charge state observations is presented. The calculations were based on atomic data, observational constraints concerning electron temperatures, electron densities and flow speeds. Minor ion charge state observations were used in order to place limits on solar wind acceleration and heating mechanisms. The charge states of C, O, Fe and Si ions measured in situ were compared to those calculated from two solar wind models. The use of the planned ultraviolet and charge state observations in order to constrain both the ion outflow speeds and electron temperature is discussed.
The Location of the Nucleus and the Morphology of Emission-Line Regions in NGC 1068

This Letter presents new Near-Infrared Camera and Multi-Object Spectrometer data on the location of the nucleus and the morphology of hydrogen and [Si VI] emission in NGC 1068. The peak of the emission at 2.2 μm is a strong point source that marks the location of the nucleus. The [Si VI] line emission region consists of two main components, a diffuse region of coronal emission to the north-northeast of the nucleus and a bright emission spot 16 from the nucleus along the direction of the radio jet. A similar but less intense emission spot also occurs in the hydrogen Paschen-α and Wide Field Planetary Camera 2 Hα images. The accurate determination of the nuclear position and its relation to the emission-line morphology produces a clearer picture of the nature of the interaction between the radio jet and its surroundings.
Thermal convection and boiling in a porous medium

Abstract Experimental observations of boiling in a water-saturated porous medium are reported. The porous medium is contained in a vertical circular cylinder of diameter D and height H which is heated from below and cooled from above. Single-cell thermal convection occurs prior to the onset of boiling. With the onset of boiling, an isothermal two-phase zone forms above the bottom in regions of ascending convection. The size of the two-phase zone increases with increasing heat flux. At high heat fluxes the cellular convertion flow disappears; a horizontal water layer is then observed to overlie a two-phase layer. A vertical countercurrent flow of liquid and vapor dominates heat transfer in the two-phase layer. In the layered state, an oscillatory boiling mode can develop which is attributed to the periodic formation of a vapor layer at the heating surface.
What Fraction of Gravitational Lens Galaxies Lie in Groups

We predict how the observed variations in galaxy populations with environment affect the number and properties of gravitational lenses in different environments. Two trends dominate: lensing strongly favors early-type galaxies, which tend to lie in dense environments, but dense environments tend to have a larger ratio of dwarf to giant galaxies than the field. The two effects nearly cancel, and the distribution of environments for lens and nonlens galaxies are not substantially different (lens galaxies are slightly less likely than nonlens galaxies to lie in groups and clusters). We predict that ~20% of lens galaxies are in bound groups (defined as systems with a line-of-sight velocity dispersion σ in the range 200 500 km s-1). Therefore, at least ~25% of lenses are likely to have environments that significantly perturb the lensing potential. If such perturbations do not significantly increase the image separation, we predict that lenses in groups have a mean image separation that is ~02 smaller than that for lenses in the field, and we estimate that 20-40 lenses in groups are required to test this prediction with significance. The tail of the distribution of image separations is already illuminating. Although lensing by galactic potential wells should rarely produce lenses with image separations θ 6'', two such lenses are seen among 49 known lenses, suggesting that environmental perturbations of the lensing potential can be significant. Further comparison of theory and data will offer a direct probe of the dark halos of galaxies and groups and reveal the extent to which they affect lensing estimates of cosmological parameters.
Structural diversity and thermochromic properties of iodobismuthate materials containing d-metal coordination cations: observation of a high symmetry [Bi3I11]2- anion and of isolated I- anions.

Six new inorganic−organic salts, all containing iodobismuthate anions and d-metal coordination cations, were synthesized solvothermally from reactions of bismuth iodide, a transition metal (M) nitrate salt (M = Co, Fe or Zn), and a heterocyclic, chelating organic ligand: 1,10-phenanthroline (1,10-phen), 3,4,7,8-tetramethyl-1,10-phenanthroline (TMphen), or 2,2′:6′,2′′-terpyridine (tpy). All six compounds were structurally analyzed by single crystal X-ray diffraction, including variable temperature crystallographic analysis to monitor for structural changes. Furthermore, those containing novel anions and achieved in high yield were additionally characterized by solid-state UV visible spectroscopy at room temperature. [Co(1,10-phen)3][Bi3I11] (1), [Fe(1,10-phen)3][Bi3I11] (2), and [Zn(1,10-phen)3][Bi3I11] (3) are isostructural. They crystallize in the monoclinic space group P21/n and contain the unprecedented iodobismuthate anion, [Bi3I11]2−, which exhibits near D3h symmetry and has an unusual arrangement of...
Maximizing throughput for optical burst switching networks

In optical burst switching (OBS) networks, a key problem is to schedule as many bursts as possible on wavelength channels so that the throughput is maximized and the burst loss is minimized. Most of the current research on OBS has been concentrated on reducing burst loss in an ldquoaverage-caserdquo sense, and little effort has been devoted to understanding the worst case performance. Since OBS itself is an open-loop control system, it may exhibit a worst case behavior when adversely synchronized. On the other hand, most commercial systems require an acceptable worst case performance. In this paper, we use competitive analysis to analyze the worst case performance of a large set of scheduling algorithms, called best-effort online scheduling algorithms, for OBS networks and establish a number of interesting upper and lower bounds on the performance of such algorithms. Our analysis shows that the performance of any best-effort online algorithm is closely related to a few factors, such as the range of offset time, maximum-to-minimum burst-length ratio, and the number of data channels. A surprising discovery is that the worst case performance of any best-effort online scheduling algorithm is primarily determined by the maximum-to-minimum burst-length ratio, followed by the range of offset time. Furthermore, if all bursts have the same burst length and offset time, all best-effort online scheduling algorithms generate the same optimal solution, regardless of how different they may look. Our analysis can also be extended to some non-best-effort online scheduling algorithms, such as the well-known Horizon algorithm, and establish similar bounds. Based on the analytic results, we give guidelines for several widely discussed OBS problems, including burst assembly, offset time setting, and scheduling algorithm design, and propose a new channel reservation protocol called virtual fixed offset-time (VFO) to improve the worst case performance. Our simulation shows that VFO can also reduce the average burst loss rate.
Determination of the antimony valence state in Eu10Mn6Sb13.

The antimony-121 Mossbauer spectra of Eu10Mn6Sb13 have been measured between 2 and 295 K. Although the Zintl formalism indicates that the nine crystallographically distinct antimony sites in Eu10Mn6Sb13 should have formal valence states of −2, −1, 0, and +1, the Mossbauer spectral isomer shifts reveal that the valence states of the different sites are all quite similar and correspond to an average electronic configuration for antimony of 5s1.75p4.0. This configuration corresponds to an excess of negative charge on the antimony of 0.7 or an average valence of −0.7, a valence which is rather consistent with the average antimony valence of −0.61 obtained from the Zintl formalism for the nine antimony sites in Eu10Mn6Sb13. The spectra obtained between 90 and 295 K are more consistent with the absence rather than the presence of any transferred magnetic hyperfine field at the antimony. In contrast, the spectra obtained at 2 and 5 K reveal the presence of an average transferred magnetic hyperfine field of ca. 8...
Circumstellar Disks in the IC 348 Cluster

We report the results of the first sensitive L-band (3.4 μm) imaging survey of the young IC 348 cluster in Perseus. In conjunction with previously acquired JHK (1.25, 1.65, and 2.2 μm) observations, we use L-band data to obtain a census of the circumstellar disk population to mK = mL ≤ 12.0 in the central ~110 arcmin2 region of the cluster. An analysis of the JHKL colors of 107 sources indicates that 65% ± 8% of the cluster membership possesses (inner) circumstellar disks. This fraction is lower than those (86% ± 8% and 80% ± 7%) obtained from similar JHKL surveys of the younger NGC 2024 and Trapezium clusters, suggesting that the disk fraction in clusters decreases with cluster age. Sources with circumstellar disks in IC 348 have a median age of 0.9 Myr, while the diskless sources have a median age of 1.4 Myr, for a cluster distance of 320 pc. Although the difference in the median ages between the two populations is only marginally significant, our results suggest that over a timescale of ~2–3 Myr more than a third of the disks in the IC 348 cluster disappear. Moreover, we find that at a very high confidence level the disk fraction is a function of spectral type. All stars earlier than G appear diskless, while stars with spectral types G and later have a disk fraction ranging between 50%–67%, with the latest-type stars having the higher disk fraction. This suggests that the disks around stars with spectral types G and earlier have evolved more rapidly than those with later spectral types. The L-band disk fraction for sources with similar ages in both IC 348 and Taurus is the same within the errors, suggesting that at least in clusters with no O stars the disk lifetime is independent of environment.
Strategic quotas on foreign investment and migration

A basic two-country, single commodity model is considered to formulate the interactive and retaliative policies with regard to restrictions on foreign investment and labor migration. We model quota retaliations using the contingent threat situation. Under three different strategic environments, we characterize the stable quotas on factor movements. Among other things, we illustrate that either one of the two countries may end up with welfare loss- Ramaswami trap, a concept we introduce in this paper.
Ultrasonic acoustic health monitoring of ball bearings using neural network pattern classification of power spectral density

This paper presents a generic passive non-contact based approach using ultrasonic acoustic emissions (UAE) to facilitate the neural network classification of bearing health, and more specifically the bearing operating condition. The acoustic emission signals used in this study are in the ultrasonic range (20-120 kHz). A direct benefit of microphones capable of measurements in this frequency range is their inherent directionality. Using selected bands from the UAE power spectrum signature, it is possible to pose the health monitoring problem as a multi-class classification problem, and make use of a single neural network to classify the ultrasonic acoustic emission signatures. Artificial training data, based on statistical properties of a significantly smaller experimental data set is used to train the neural network. This specific approach is generic enough to suggest that it is applicable to a variety of systems and components where periodic acoustic emissions exist.
Phase Slips and the Eckhaus Instability

We consider the Ginzburg-Landau equation, delta tu= delta x2u+u-u mod u mod 2, with complex amplitude u(x, t). We first analyse the phenomenon of phase slips as a consequence of the local shape of u. We next prove a global theorem about evolution from an Eckhaus unstable state, all the way to the limiting stable finite state, for periodic perturbations of Eckhaus unstable periodic initial data. Equipped with these results, we proceed to prove the corresponding phenomena for the fourth-order Swift-Hohenberg equation, of which the Ginzburg-Landau equation is the amplitude approximation. This sheds light on how one should deal with local and global aspects of phase slips for this and many other similar systems.
Flavonoids are scavengers of superoxide anions

Seven flavonoids and three non-flavonoid antioxidants, i.e. butylated hydroxyanisole, chlorpromazine and BW 755 C, were studied as potential scavengers of oxygen free radicals. Superoxide anions were generated enzymatically in a xanthine-xanthine oxidase system and non-enzymatically in a phenazine methosulphate-NADH system, and assayed by reduction of nitro blue tetrazolium. The generation of malonaldehyde (MDA) by the ascorbate-stimulated air-oxidised boiled rat liver microsomes was considered as an index of the non-enzymatic formation of hydroxyl radicals. Flavonoids but not non-flavonoid antioxidants lowered the concentration of detectable superoxide anions in both enzymic and non-enzymic systems which generated these SOD-sensitive radicals. The most effective inhibitors of superoxide anions were quercetin, myricetin and rutin. Four out of seven investigated flavonoids seemed also to suppress the activity of xanthine oxidase as measured by a decrease in uric acid biosynthesis. All ten investigated compounds inhibited the MDA formation by rat liver microsomes. Non-flavonoid antioxidants were more potent MDA inhibitors than flavonoids. It is concluded that antioxidant properties of flavonoids are effected mainly via scavenging of superoxide anions whereas non-flavonoid antioxidants act on further links of free radical chain reactions, most likely by scavenging of hydroxyl radicals.
The purpose of concurrent Pascal

This is the first of three papers that describe a new programming language for structured programming of computer operating systems [1, 2, 3]. It extends the sequential programming language Pascal with concurrent programming tools called processes and monitors. These concepts are explained informally by means of pictures that illustrate a hierarchical design of a simple spooling system. The main contribution of Concurrent Pascal is to extend the monitor concept with an explicit hierarchy of access rights to shared data structures that can be stated in the program text and checked by a compiler.[1]Brinch Hansen, P. The purpose of Concurrent Pascal. Information Science, California Institute of Technology, November 1974.[2]Brinch Hansen, P. The use of Concurrent Pascal. Information Science, California Institute of Technology, November 1974.[3]Brinch Hansen, P. Job control in Concurrent Pascal. Information Science, California Institute of Technology. November 1974.
Type Ia supernova-driven Galactic bulge wind

Stellar feedback in Galactic bulges plays an essential role in shaping the evolution of galaxies. To quantify this role and facilitate comparisons with X-ray observations, we conduct three-dimensional hydrodynamical simulations with the adaptive mesh refinement code, FLASH, to investigate the physical properties of hot gas inside a Galactic bulge, similar to that of our Galaxy or M 31. We assume that the dynamical and thermal properties of the hot gas are dominated by mechanical energy input from supernovae (SNe), primarily type Ia, and mass injection from evolved stars as well as iron enrichment from SNe. We study the bulge-wide outflow as well as the SN heating on scales down to ~4 pc. An embedding scheme that is devised to plant individual supernova remnant (SNR) seeds allows examining, for the first time, the effect of sporadic SNe on the density, temperature and iron ejecta distribution of the hot gas as well as the resultant X-ray morphology and spectrum. We find that the SNe produce a bulge wind with highly filamentary density structures and patchy ejecta. Compared with a one-dimensional (1D) spherical wind model, the non-uniformity of simulated gas density, temperature and metallicity substantially alters the spectral shape and increases the diffuse X-ray luminosity. The differential emission measure as a function of temperature of the simulated gas exhibits a lognormal distribution, with a peak value much lower than that of the corresponding 1D model. The X-ray luminosity depends sensitively on the mass-loss rate from evolved stars. The bulk of the X-ray emission comes from the relatively low-temperature and low-abundance gas shells associated with SN blastwaves. SN ejecta are not well mixed with the ambient medium, at least in the bulge region. These results, at least partly, account for the apparent lack of evidence for iron enrichment in the soft X-ray-emitting gas in Galactic bulges and intermediate-mass elliptical galaxies. The bulge wind helps to explain the 'missing' stellar feedback in such galaxies. But the resultant diffuse emission is more than one order of magnitude less than that observed in the Galactic and M 31 bulges, indicating that gas in these bulges is in a subsonic outflow state probably due to additional mass loading to the hot gas and/or due to energy input rate that is substantially lower than the current estimate.
Bilirubin as an inhibitor of cartilage metabolism: effect on avian chondrocyte proliferation in cell culture.

Elevated levels of bilirubin and other tetrapyrroles are common to a number of chronic hematologic and liver diseases that can result in growth failure. This report establishes a cellular model system for the study of these endogenous growth inhibitors. Primary chondrocyte cultures were prepared from embryonic chick cartilage; cells were incubated (0.3 ± 105 cells per plate) in tissue culture medium containing 10% fetal bovine serum (FBS) with or without added bilirubin, 0.01-0.10 mM. Bilirubin caused profound, dose-dependent inhibition of chondrocyte proliferation: after 7 days, control incubations contained 11.45 ± 2.0 ± 105 cells per plate versus 4.92 ± 0.55 ± 105 cells per plate for wells with added 0.01 mM bilirubin and 1.76 ± 0.30 ± 105 for cultures with added 0.05 mM bilirubin. In chondrocytes cultured for 3 days, the addition of 0.05 mM bilirubin was associated with inhibition of [3H]thymidine incorporation into DNA (47 ± 5% of control), [3H]uridine incorporation into RNA (11 ± 0.05% of control), and [14C]leucine incorporation into proteins (16 ± 1% of control). The inhibition of chondrocyte proliferation induced by a range of bilirubin concentrations (0.01-0.10 mM) was in no way attenuated by the addition of physiologic concentrations of albumin (4 g/dl). After 3 days in media containing bilirubin or heme (at equimolar concentrations), chondrocytes were subsequently incubated in FBS alone for an additional 3 days; only partial reversal of the bilirubin (or heme)-induced inhibition was then observed. Our data show that bilirubin (and heme) produces profound, dose-dependent, partially reversible inhibition of chondrocyte proliferation in culture without affecting cell viability, supporting the concept that these endogenous tetrapyrroles are potent growth inhibitors. We also conclude that chick chondrocytes in cell culture are a suitable model for delineating the mechanisms of tetrapyrrole tissue action.
Quantum Error Correction of Time-correlated Errors

The complexity of the error correction circuitry forces us to design quantum error correction codes capable of correcting a single error per error correction cycle. Yet, time-correlated error are common for physical implementations of quantum systems; an error corrected during the previous cycle may reoccur later due to physical processes specific for each physical implementation of the qubits. In this paper, we study quantum error correction for a restricted class of time-correlated errors in a spin-boson model. The algorithm we propose allows the correction of two errors per error correction cycle, provided that one of them is time-correlated. The algorithm can be applied to any stabilizer code when the two logical qubits $$\mid {\rm 0}_L \rangle$$ and $$\mid {\rm 1}_L \rangle$$ are entangled states of 2 n basis states in $${\mathcal{H}}_{2^n}$$ .
On gauge bosons in the matrix model approach to M theory

Abstract We discuss the appearance of E8 × E8 gauge bosons in Banks, Fischler, Shenker, and Susskind's zero brane quantum mechanics approach to M theory, compactified on the interval S 1 Z 2 . The necessary bound states of zero branes are proven to exist by a straightforward application of T-duality and heterotic Spin(32)/Z2-Type I duality. We then study directly the zero brane Hamiltonian in Type I′ theory. This Hamiltonian includes couplings between the zero branes and background Dirichlet 8 branes licalized at the orientifold planes. We identify states, localized at the orientifold planes, with the requisite gauge boson quantum numbers. An interesting feature is that E8 gauge symmetry relates bound states of different numbers of zero branes.
Mesh and pyramid algorithms for iconic indexing

Abstract Parallel algorithms on meshes and pyramids for iconic indexing are presented. The algorithms are asymptotically superior to previously known parallel algorithms. Also presented are experimental results for these algorithms on the Connection Machine (CM-2).
Interpretation of FEL gain and magnetic-field errors on the SCA/FEL

Abstract Measurements confirm that, with external steering, wiggler errors (1.2% rms over 120 periods) do not appreciably broaden the spontaneous spectrum. Calculations indicate that larger errors could be tolerated if they did not cause steering errors. Efforts are made to reconcile the observed FEL gain with optical and electron-beam measurements.
Free Entry, Quasi‐Free Trade, and Strategic Export Policy

This paper analyzes governments’ choices between strategic export subsidies and free trade as a commitment when firms are free to enter or exit in response to these choices. Entry and exit is treated as a discrete process. Within the context of a four-stage game, two types of equilibria emerge: a quasi-free-trade equilibrium in which one of the two governments commits to free trade, while the other has a Nash equilibrium subsidy that is zero and bilateral export subsidies. Concerning welfare effects, if fixed costs are large enough, both countries achieve a welfare gain relative to free trade.
Melting ablation about decelerating spherical bodies.

Heat transfer and melting ablation about decelerating spherical bodies during planetary atmosphere entry
VIROLOGIC ASSISTANCE IN THE MANAGEMENT OF GERMAN MEASLES IN PREGNANCY.

During the current epidemic of rubella, it has been possible to make use of the newly discovered methods for isolation of the virus and for the serologic diagnosis of rubella in testing of specimens from pregnant women who had suffered rubella-like illness or who had been exposed to the disease. Nasopharyngeal swabs obtained during the first week after onset of the rash and especially during the first few days were often positive. Serologic diagnosis was quite feasible using acute and convalescent specimens and on occasion it was still possible to show a rising titer when the first serum had been obtained two weeks after the rash.
Belief Change in Branching Time: AGM-consistency and Iterated Revision

We study belief change in the branching-time structures introduced in Bonanno (Artif Intell 171:144–160, 2007). First, we identify a property of branching-time frames that is equivalent (when the set of states is finite) to AGM-consistency, which is defined as follows. A frame is AGM-consistent if the partial belief revision function associated with an arbitrary state-instant pair and an arbitrary model based on that frame can be extended to a full belief revision function that satisfies the AGM postulates. Second, we provide a set of modal axioms that characterize the class of AGM-consistent frames within the modal logic introduced in Bonanno (Artif Intell 171:144–160, 2007). Third, we introduce a generalization of AGM belief revision functions that allows a clear statement of principles of iterated belief revision and discuss iterated revision both semantically and syntactically.
Findings of the US research needs workshop on the topic of fusion power

The US Department of Energy, Office of Fusion Energy Sciences (OFES) conducted a Research Needs Workshop, referred to as ReNeW, in June 2009. The information developed at this workshop will help OFES develop a plan for US fusion research during the ITER era, roughly the next two decades. The workshop was organized in five Themes, one of which was Harnessing Fusion Power (or Fusion Power for short). The top level goal of the Fusion Power Theme was to identify the research needed to develop the knowledge to design and build, with high confidence, robust and reliable systems that can convert fusion products to useful forms of energy in a reactor environment, including a self-sufficient supply of tritium fuel. Each Theme was subsequently subdivided into Panels to address specific topics. The Fusion Power Panel topics were: Fusion Fuel Cycle; Power Extraction; Materials Science; Safety and Environment; and Reliability, Availability, Maintainability and Inspectability (RAMI). Here we present the key findings of the Fusion Power Theme.
Politics, Parents, and Prophylaxis — Mandating HPV Vaccination in the United States

R. Alta Charo writes that access to the HPV vaccines has already become more a political than a public health question. Though the more important focus might be on the high cost of the vaccines, concern has focused instead on a purported interference in family life and sexual mores. Professor Charo discusses the legal, political, ethical, and financial considerations surrounding the mandating of HPV vaccination in the United States. R. Alta Charo is a professor of law and bioethics at the University of Wisconsin, Madison.
Multi-unit auctions with uniform prices

Auctions in which individuals can purchase more than one unit of the good being sold differ in striking ways from multi-unit auctions in which individuals may purchase only one unit. The uniform price auction in particular frequently yields Nash equilibria in which bidders underbid for their second unit and therefore pay very low prices for the good. This paper characterizes equilibria for the uniform price auction.
Intermediate Jacobians and ADE Hitchin systems

Let $\Sigma$ be a smooth projective complex curve and $\mathfrak{g}$ a simple Lie algebra of type ${\sf ADE}$ with associated adjoint group $G$. For a fixed pair $(\Sigma, \mathfrak{g})$, we construct a family of quasi-projective Calabi-Yau threefolds parameterized by the base of the Hitchin integrable system associated to $(\Sigma,\mathfrak{g})$. Our main result establishes an isomorphism between the Calabi-Yau integrable system, whose fibers are the intermediate Jacobians of this family of Calabi-Yau threefolds, and the Hitchin system for $G$, whose fibers are Prym varieties of the corresponding spectral covers. This construction provides a geometric framework for Dijkgraaf-Vafa transitions of type ${\sf ADE}$. In particular, it predicts an interesting connection between adjoint ${\sf ADE}$ Hitchin systems and quantization of holomorphic branes on Calabi-Yau manifolds.
Bugbuster—survivability of living bacteria upon shock compression

Shock recovery experiments were conducted on suspensions of 10^6/ml E. coli bacteria contained in a water-based medium that is emplaced within stainless steel containers. The water is shocked and recovered. These experiments simulate the environment of bacteria residing either in surface bodies of water or in subsurface water-filled cracks in rocks. Early Earth life is likely to have existed in such environments. However, the E. coli are not believed to be representative of early life and are merely used here for initial experiments. Some 10^(− 2) to 10^(− 4) of the bacteria population survived initial (800 ns duration) shock pressures in water of 220 and 260 MPa. TEM images of shock recovered bacteria indicate cell wall rupture and delamination. This appears to be the mortality mechanism. The TEM images indicate cell wall indentations may be occurring as would be consistent with Rayleigh–Taylor or Richtmyer–Meshkov fluid instabilities. In the present case, we consider the experiments as representing three layers of fluids: (1) The water-based medium, a stronger and possibly denser cell wall medium, and the interior of the cell cytoplasm. Variations of only 10–15% are expected in density. (2) A second mechanism that may cause cell wall failure is the multiple shock (nearly isentropic) compression freezing of liquid water medium into ice VI or ice VII high pressure phase that are 20% to 25% denser than the liquid. The decrease in volume associated with the transformation is expected to induce overpressures in the still liquid cell cytoplasm. Cell dynamic tensile wall strength thus appears to be a critical parameter from either of the above failure modes. Because the strain rate dependence of cell wall tensile strength is unstudied, we utilize the Grady and Lipkin [D.E. Grady, L. Lipkin, Criteria for impulsive rock fracture, Geophys. Res. Lett. 7 (1980) 255–258] model of tensile failure versus time scale (strain rate). Our single datum is fit to this law and we assume that at low strain rates, overpressures exceeding the cell Turgor pressure require on the order of ∼10^3 s. This model which has been applied to brittle media and metals for describing failure may permit application of short duration laboratory experiments as in the present ones to infer responses of organisms to much lower shock pressures, but for longer time scales (10^0 to 10^3 s) of planetary impacts. Using the present data for E. coli and applying the Grady and Lipkin model, we find that a 1.5 km diameter impactor will cause mortality of bacteria within a radius of 10^2 km but upon stress related attenuation the subsurface bacteria outside of this radius should survive.
Designing efficient aberration-free holographic lenses in the presence of a construction–reconstruction wavelength shift

We have derived an analytic procedure for recording a flat, volume-phase-transmission holographic optical element at a wavelength different from that at which it is to be used. The procedure guarantees that the resulting element will have diffraction-limited aberration performance. Furthermore it guarantees, to a first order, that the Bragg condition for high diffraction efficiency will be satisfied. The technique gives simple analytic expressions for the required object and reference construction-beam phases at the element. In general, the object and reference construction beams must be realized by using computer-generated holograms in conjunction with conventional refractive or reflective optics.
Massless Dirac Fermions, Gauge Fields, and Underdoped Cuprates

We study 2+1 dimensional massless Dirac fermions and bosons coupled to a U(1) gauge field as a model for underdoped cuprates. We find that the uniform susceptibility and the specific heat coefficient are logarithmically enhanced (compared to linear-in-T behavior) due to the fluctuation of a transverse gauge field which is the only massless mode at finite boson density. We analyze existing data, and find good agreement in the spin gap phase. Within our picture, the drop of the susceptibility below the superconducting T{sub c} arises from the suppression of gauge fluctuations. {copyright} {ital 1997} {ital The American Physical Society}
Synthesis of 4-amino 3,4-dideoxy-d-arabino-heptulosonic acid 7-phosphate, the biosynthetic precursor of C7N units in ansamycin antibiotics

Abstract The synthesis of 4-amino-3,4-dideoxy- d -arabino-heptulosonic acid 7-phosphate (15), the first committed intermediate in a new branch of the shikimate pathway of aromatic biosynthesis, is reported from 2-deoxy- d -glucose in 14 steps in 10–12% overall yield.
Using Auxiliary Sensors for Pairwise Key Establishment in WSN

Many techniques have been developed recently for establishing pairwise keys in sensor networks. However, some of them are vulnerable to a few compromised sensor nodes, while others could involve expensive protocols for establishing keys. This article introduces a much better alternative that can achieve both high resilience to node compromises and high efficiency in key establishment. The main idea is to deploy a small number of additional sensor nodes, called assisting nodes, to help key establishment between sensor nodes. The proposed approach has many advantages over existing approaches. In particular, a sensor node only needs to make a few local communications and perform a few efficient hash operations to setup a key with any other sensor node in the network at a very high probability. The majority of sensor nodes only need to store a single key. Besides, it also provides high resilience to node compromises. The theoretical analysis, simulation studies, and experiments on TelosB sensor motes also demonstrate the advantages of this key establishment protocol in sensor networks.
On the J-anti-invariant cohomology of almost complex 4-manifolds

For a compact almost complex 4-manifold $(M,J)$, we study the subgroups $H^{\pm}_J$ of $H^2(M, \mathbb{R})$ consisting of cohomology classes representable by $J$-invariant, respectively, $J$-anti-invariant 2-forms. If $b^+ =1$, we show that for generic almost complex structures on $M$, the subgroup $H^-_J$ is trivial. Computations of the subgroups and their dimensions $h^{\pm}_J$ are obtained for almost complex structures related to integrable ones. We also prove semi-continuity properties for $h^{\pm}_J$.
Weak semistable reduction in characteristic 0

Let X->B be a morphism of varieties in characteristic zero. Semistable reduction has been proved for dim(B)=1 (Kempf, Knudsen, Mumford, Saint-Donat), dim(X)=dim(B)-1 (de Jong) and dim(X)=dim(B)+2 (Alexeev, Kollar, Shepherd-Barron). In this paper we consider the general case. First we define what we mean by a semistable morphism in terms of toroidal embeddings. Then we reduce the varieties to toroidal embeddings and solve a slightly weaker version of semistable reduction. We also state the full semistable reduction problem in terms of combinatorics of the associated polyhedral complexes.
Dynamical Outcomes of Planet-Planet Scattering

Observations in the past decade have revealed extrasolar planets with a wide range of orbital semimajor axes and eccentricities. Based on the present understanding of planet formation via core accretion and oligarchic growth, we expect that giant planets often form in closely packed configurations. While the protoplanets are embedded in a protoplanetary gas disk, dissipation can prevent eccentricity growth and suppress instabilities from becoming manifest. However, once the disk dissipates, eccentricities can grow rapidly, leading to close encounters between planets. Strong planet-planet gravitational scattering could produce both high eccentricities and, after tidal circularization, very short period planets, as observed in the exoplanet population. We present new results for this scenario based on extensive dynamical integrations of systems containing three giant planets, both with and without residual gas disks. We assign the initial planetary masses and orbits in a realistic manner following the core accretion model of planet formation. We show that, with realistic initial conditions, planet-planet scattering can reproduce quite well the observed eccentricity distribution. Our results also make testable predictions for the orbital inclinations of short-period giant planets formed via strong planet scattering followed by tidal circularization.
On the failure of spin–statistics connection in quantum gravity

Abstract Many years ago Friedman and Sorkin [Phys. Rev. Lett. 44 (1980) 1100; Gen. Rel. Grav. 14 (1982) 615] established the existence of certain topological solitonic excitations in quantum gravity called (topological) geons. Geons can have quantum numbers like charge and can be tensorial or spinorial having integer or half-odd integer spin. A striking result is that geons can violate the canonical spin–statistics connection. Such violation induces novel physical effects at low energies. The latter will be small since the geon mass is expected to be of the order of Planck mass. Nevertheless, these effects are very striking and include CPT and causality violations and distortion of the cosmic microwave spectrum. Interesting relations of geon dynamics to supersymmetry are also discussed.
Self-healing by means of runtime execution profiling

A self-healing application brings itself into a stable state after a failure put the software into an unstable state. For such self-healing software application, finding fix for a previously unseen fault is a grand challenge. Asking the user to provide fixes for every fault is bad for productivity, especially when the users are non-savvy in technical aspect of computing. If failure scenarios come into existence, the user wants the runtime environment to handle those situations autonomically. This paper presents a new technique of finding self-healing actions by matching a fault scenario to already established fault models. By profiling and capturing runtime parameters and execution pathways, stable execution models are established and later are used to match with an unstable execution scenario. Experimentation and results are presented that showed that even with additional overheads; this technique can prove beneficial for autonomically healing faults and reliving system administrators from mundane troubleshooting situations.
Building models of gauge-mediated supersymmetry breaking without a messenger sector

Abstract We propose a general scheme for constructing models in which the Standard Model (SM) gauge interactions are the mediators of supersymmetry breaking to the fields in the supersymmetric SM, but where the SM gauge groups couple directly to the sector which breaks supersymmetry dynamically. Despite the direct coupling, the models preserve perturbative unification of the SM gauge coupling constants. Furthermore, the supergravity contributions to the squark and slepton masses can be naturally small, typically being much less than 1% of the gauge-mediated (GM) contributions. Both of these goals can be achieved without need of a fine-tuning or a very small coupling constant. This scheme requires run-away directions at the renormalizable level which are only lifted by non-renormalizable terms in the superpotential. To study the proposed scheme in practice, we develop a modified class of models based on SU ( N ) × SU ( N − 1) which allows us to gauge an SU ( N − 2) global symmetry. However, we point out a new problem which can exist in models where the dynamical supersymmetry breaking sector and the ordinary sector are directly coupled - the two-loop renormalization group has contributions which can induce negative (mass) 2 for the squarks and sleptons. We clarify the origin of the problem and argue that it is likely to be surmountable. We give a recipe for a successful model.
Using Field Experiments to Change the Template of How We Teach Economics

In this article, the author explains why field experiments can improve what we teach and how we teach economics. Economists no longer operate as passive observers of economic phenomena. Instead, they participate actively in the research process by collecting data from field experiments to investigate the economics of everyday life. This change can be shown to students by presenting them with evidence from field experiments. Field experiments related to factor markets, behavioral economics, and discrimination are presented to explain how this approach works across different economic content. The three questions that are highlighted are the following: (1) Why do women get paid less than men in labor markets? (2) How can we use behavioral economics to motivate teachers? (3) What seven words can end third-degree price discrimination?
Multiple limit cycles in laser interference transduced resonators

Nanoscale resonators whose motion is measured through laser interferometry are known to exhibit stable limit cycle motion. Motion of the resonator through the interference field modulates the amount of light absorbed by the resonator and hence the temperature field within it. The resulting coupling of motion and thermal stresses can lead to self-oscillation, i.e. a limit cycle. In this work the coexistence of multiple stable limit cycles is demonstrated in an analytic model. Numerical continuation and direct numerical integration are used to study the structure of the solutions to the model. The effect of damping is discussed as well as the properties that would be necessary for physical devices to exhibit this behavior.