cssi/SciSciGPT-SciSciNet huggingface dataset:
Numerical simulation of fine structure in the Io plasma torus produced by the centrifugal interchange instability

[1] The Io plasma torus as a whole has a radial width scale ∼1 RJ, much larger than the width of the localized Io plasma source (∼1 RIo ≈ RJ/39). One of the most prominent features of the Io torus observed by the Voyager spacecraft and Earth-based instruments is the “ribbon” structure near Io's orbit. The stability properties of this narrower ribbon structure embedded within the larger torus have been investigated by the Rice Convection Model for Jupiter. Four initial plasma distributions having different radial widths are each represented by 82 longitudinally symmetric edges establishing 41 levels of the flux tube mass content η with the peak η value at Io's orbit. The same initial perturbation is put on each of these edges and is subjected to centrifugal interchange. Our simulations produce regularly spaced long, thin fingers moving outward from the outer edges. It is shown that the azimuthal width of the interchange convection cells (the distance between outflowing fingers in the nonlinear stage of development) is proportional to the radial width scale of the initial distribution that produced them. The constant of proportionality is ≈0.5. Since the exponential growth rate is essentially proportional to the azimuthal wave number of the disturbance and hence is inversely proportional to its azimuthal width, the ribbon-scale interchange structures grow faster than torus-scale interchange structures.
The effect of rain on air-water gas exchange

The relationship between gas transfer velocity and rain rate was investigated at NASA's Rain-Sea Interaction Facility (RSIF) using several SF 6 evasion experiments. During each experiment, a water tank below the rain simulator was supersaturated with SF 6 , a synthetic gas, and the gas transfer velocities were calculated from the measured decrease in SF 6 concentration with time. The results from experiments with 18 different rain rates (7 to 110 mm h −1 ) and 1 of 2 dropsizes (2.8 or 4.2 mm diameter) confirm a significant and systematic enhancement of air-water gas exchange by rainfall. The gas transfer velocities derived from our experiment were related to the kinetic energy flux calculated from the rain rate and dropsize. The relationship obtained for mono-dropsize rain at the RSIF was extrapolated to natural rain using the kinetic energy flux of natural rain calculated from the Marshall-Palmer raindrop size distribution. Results of laboratory experiments at RSIF were compared to field observations made during a tropical rainstorm in Miami, Florida and show good agreement between laboratory and field data. DOI: 10.1034/j.1600-0889.49.issue2.3.x
Electrophile-induced ether transfer: a new approach to polyketide structural units.

A strategically novel approach to the formation of syn-1,3-diol mono- and diethers through electrophilic activation of homoallylic alkoxymethyl ethers has been developed. The resulting polyketide-like synthetic fragments are generated in good yield and with excellent stereocontrol. A chairlike transition state is proposed to account for the high stereoselectivity. Varying the conditions of the reaction workup results in the efficient generation of mono- and diether containing structural units common to polyketide natural products.
A formal system for the specification of the syntax and translation of computer languages

This paper presents two basic results: the use of established methods of recursive definition to present a single method to1. specify the syntax of computer languages (including context sensitive requirements, such as the restrictions implied by declaration statements),2. specify the translation of programs in one computer language into programs in another language.
Nonparametric regression under alternative data environments

Abstract This manuscript proposes a nonparametric regression estimator which can accommodate two empirically relevant data environments. The first data environment assumes that at least one of the explanatory variables is discrete. In such an environment a “cell” approach which consists of partitioning the data and estimating a separate regression for each discrete cell has usually been employed. The second data environment assumes that one needs to estimate a set of conditional mean functions that belong to different experimental units. In both environments the proposed estimator attempts to reduce estimation error by incorporating extraneous data from the other experimental units (or cells) when estimating the conditional mean function for a given experimental unit. Consistency and asymptotic normality of the proposed estimator are established. Its computational simplicity and simulation results demonstrate a strong potential for empirical application.
Preparation and electrochemical properties of glass-polymer composite electrolytes for lithium batteries

Electrochemical behavior of a new class of glass-polymer composites (GPC), consisting of (100−x) vol% (0.56Li2S·0.19B2S3·0.25LiI) glass and x vol% (P(EO)6·LiN(CF3SO2)2) polymer with x = 7, 13 and 25, has been investigated in cells with different electrodes. Results show that the addition of the polymer to the glass powder increases not only the mechanical flexibility but also the ionic conductivity. The combination of impedance spectroscopy and 4-probe dc measurements indicates that the GPC with x = 13 vol% polymer exhibits the highest lithium ion conductivity, varying from 3 × 10−4 Ω−1 cm−1 at room temperature to 1.4 × 10−3 Ω cm−1 at 80 °C. In addition, the GPC electrolytes with x = 13 vol% seem to be relatively stable against Li, LixMn2O4, and carbon electrodes, since interfacial impedances between the electrolyte and the electrode materials are relatively constant at 70 °C for up to 375 hours.
Series-specific Unit Root Tests with Panel Data*

A unit root testing procedure is presented that exploits the well-established power advantages of panel estimation while rectifying a deficiency in other panel unit root tests. This test (called SURADF) is based on seemingly unrelated regressions applied to Augmented Dickey-Fuller (ADF) tests for a unit root. In contrast to extant panel unit root tests, our test allows for determination of which members of the panel reject the null hypothesis of a unit root and which ones do not. The power of the test is investigated with Monte Carlo simulation and demonstrated with application to several panels of real exchange rates. We find that when the contemporaneous cross-correlations of the residuals are high, our procedure has substantially more power to reject a unit root than the single equation Dickey-Fuller test. Copyright 2002 by Blackwell Publishing Ltd
Edge linking by sequential search

Edge detection is mainly a two-stage process: edge enhancement followed by edge linking. In this paper we develop a linking algorithm for the combination of edge elements enhanced by an optimal filter. The linking algorithm (LINK) is based on sequential search. From a starting node, transitions are made to the goal nodes based on a maximum likelihood metric. Results of our search algorithm are compared to the sequential edge linking algorithm (SEL) as well as to two common nonsequential algorithms based on tracing the zero-crossings loci in the convolution output of the ▿2G operators, and based on nonmaximal suppression and thresholding of the convolution output of the ▿G operator. It is shown that the LINK algorithm provides comparable results, require only local calculations, and can accommodate any a priori information in the path metric used to guide the search.
Introduction and tribute to S. Thomas Crough 1947–1982

Tom Crough's friends remember him as warm, shy, inspiring. He was slow to discover his flair for geophysics. He graduated in economics in 1969 from the Woodrow Wilson School at Princeton. After graduation, he and Faith, a zoology graduate of the University of Ohio, were married; Tom described meeting Faith as the best thing that ever happened to him.
Back to the future: 900 years of securitization

Purpose – Before the 2007 financial crisis, securitized products accounted for half the credit market. Once regarded as one of the biggest financial innovations of the last century, securitization is now viewed as a contributory factor to the crisis. Until recently research has focused on the post-1970s mortgage securitization market. In this paper, I trace the earlier origins of securitization, from the 12th century Genoese compera through to early 20th century efforts. The historical examples highlight unifying themes on risk allocation and complexity. As the future securitization market remains uncertain, it is important to consider lessons to be learned from these historical episodes. Design/methodology/approach – This is primarily a survey article that utilizes historical documents to compare/contrast features of securitization with the recent crisis. Findings – Improved disclosure is the key element to address recent securitization flaws, but disclosure does not really matter if the entire process i...
A Classification of certain finite Double Coset Collections in the Classical Groups

Let $G$ be a classical algebraic group, $X$ a maximal rank reductive subgroup and $P$ a parabolic subgroup. This paper classifies when $X\backslash G/P$ is finite. Finiteness is proven using geometric arguments about the action of $X$ on subspaces of the natural module for $G$ . Infiniteness is proven using a dimension criterion that involves root systems.
Fluctuating Membranes with Tilt Order

Thermal fluctuations are important for amphiphilic bilayer membranes since typical bending stiffnesses can be a few k B T. The rod-like constituent molecules are generically tilted with respect to the local normal for packing reasons. We study the effects of fluctuations on membranes with nematic order, a simplified idealization with the same novel features as realistic tilt order. We find that nematic membranes lie in the same universality class as hexatic membranes, i.e. the couplings that distinguish nematic from hexatic order are marginally irrelevant. Our calculation also illustrates the advantages of conformal gauge, which brings great conceptual and technical simplifications compared to the more popular Monge gauge.
Constructions of given-depth and optimal multirate rearrangeably nonblocking distributors

Rearrangeable multirate multicast switching networks are customarily called rearrangeable multirate distributors. It has been known for a long time that rearrangeable multirate distributors with cross-point complexity O(nlog?2 n) can be constructed, where n is the number of inputs (and outputs) of the switching network. The problem of constructing optimal distributors remains open thus far. This paper gives a general construction of rearrangeable multirate distributors with given depths. One byproduct is a rearrangeable multirate distributor with crosspoint complexity O(nlog?n). We also show that this cross-point complexity is optimal, settling the aforementioned open problem. One of the key ingredients of our new construction is the notion of multirate concentrators. The second ingredient is a multirate version of the Pippenger network. We show how to construct given-depth multirate concentrators and given-depth multirate Pippenger networks with small sizes. When the depth is chosen to optimize the size, we obtain the optimal O(nlog?n) cross-point complexity.
A realistic technicolor model from 150 TeV down

Abstract A realistic technicolor model is presented with the dynamics below 150 TeV treated explicitly. Electroweak symmetry is broken by the condensates of a “minimal” doublet of technifermions. The new feature of the model is that the third generation quarks are unified with the technifermions into multiplets of a walking gauge force down to a scale of 10 TeV. The remaining quarks and leptons are not involved in this unification however. The walking dynamics enhances the higher dimension interactions which give the ordinary fermions their masses and mixing, while leaving flavor-changing neutral currents suppressed. Because the third generation quarks actually feel the walking force their masses can be much larger than those of the other quarks and the leptons. The only non-standard particles with masses below several TeV are the single doublet of technifermions, so electroweak radiative corrections are estimable and within experimental limits. The tuning of couplings is mild.
Channels‐tidal flat sediment exchange: The channel spillover mechanism

[1] We analyze the hydrodynamics and sediment transport on a mudflat in Willapa Bay, Washington State, United States. Velocity profiles and suspended sediment concentrations were simultaneously measured for 46 days in a major flow-through channel, in a dead-end tributary channel, on the channel bank, and on the adjacent tidal flat, encompassing periods with and without wind waves. A lateral circulation, perpendicular to the direction of the main channel, is observed to be associated with high sediment discharge directed from the channel to the tidal flat at the beginning of flood. This sediment discharge is able to explain the turbid tidal edge, which is a common feature of many tidal flats. An analytical model describing the lateral circulation and a conceptual model describing the sediment spillover from the channel are proposed. According to the model, the tidal flat sediment dynamics are strongly influenced by the sediment input from the main channel during fair weather, a process that is often overlooked in simplified models of tidal flat morphodynamics.
Circular dichroism of some mononucleosides.

The circular dichroism (CD) and absorption spectra of uridine, thymidine, purine ribonucleoside, and the four adenine derivatives 2′-deoxyadenosine, adenosine, adenosine-3′,5′-cyclic phosphate, and arabinosyl adenine were measured in water at pH 7 and pH 2. The absorption and CD spectra of the pyrimidines were simultaneously fitted to four Gaussian bands, and the dipole and rotational strengths of the electronic transitions determined. Adenine-derivative CD spectra were determined by computer averaging six runs. The spectra showed CD bands at 268, 226, 209, and 195 nm. The band at 226 nm probably is an n–π* transition; the band at 209 nm cannot be detected without a computer. The CD and absorption spectra of purine ribonucleoside indicate three transitions in the 230–310-nm region.
Enantiomeric Separation of Sulfonium Ions by Capillary Electrophoresis Using Neutral and Charged Cyclodextrins

Capillary zone electrophoresis was successfully applied, for the first time, to the chiral separation of structurally related sulfonium ions, using sodium phosphate buffer pH 2.5 with β-cyclodextrin (β-CD) or sulfated-β-cyclodextrin (S-β-CD) as the chiral selector with tetrabutylammonium bromide (TBA). For this study, a series of structurally related sulfonium ions in which one of the alkyl chains varied in length were synthesized from a common sulfide. The resolution of the ions was found to be dependent on the type of cyclodextrin used, the presence or absence of TBA, and the structure of the sulfonium ion. β-CD was found to be effective only for ions containing two aromatic groups, while the S-β-CD was effective only for ions containing one aromatic group. The chiral separation of thiophenium ions was also studied under the conditions established. Chiral separation of sulfonium ions in a binary buffer system containing methanol was explored as well. Separations were achieved for all but one sulfonium i...
On the chiral rings in N=2 and N=4 superconformal algebras

We study the chiral primary rings of N=2 and N=4 superconformal algebras (SCA’s) constructed over triple systems. The chiral primary states of N=2 SCA’s realized over Hermitian Jordan triple systems are given. Their coset spaces G/H are Hermitian-symmetric and can be compact or noncompact. In the noncompact case under the requirement of unitarity of the representations of G, we find an infinite discrete set of chiral primary states associated with the holomorphic discrete series representations of G and their analytic continuation. A further requirement that the corresponding N=2 module be unitary truncates this infinite set to a finite subset. There are no chiral primary states associated with the other unitary representations of noncompact groups. Remarkably, the only noncompact groups G that admit holomorphic discrete series unitary representations are such that their quotients G/H with their maximal compact subgroups H are Hermitian-symmetric. The chiral primary states of N=2 SCA’s constructed over th...
Fault-tolerance in the borealis distributed stream processing system

Over the past few years, Stream Processing Engines (SPEs) have emerged as a new class of software systems, enabling low latency processing of streams of data arriving at high rates. As SPEs mature and get used in monitoring applications that must continuously run (e.g., in network security monitoring), a significant challenge arises: SPEs must be able to handle various software and hardware faults that occur, masking them to provide high availability (HA). In this article, we develop, implement, and evaluate DPC (Delay, Process, and Correct), a protocol to handle crash failures of processing nodes and network failures in a distributed SPE.Like previous approaches to HA, DPC uses replication and masks many types of node and network failures. In the presence of network partitions, the designer of any replication system faces a choice between providing availability or data consistency across the replicas. In DPC, this choice is made explicit: the user specifies an availability bound (no result should be delayed by more than a specified delay threshold even under failure if the corresponding input is available), and DPC attempts to minimize the resulting inconsistency between replicas (not all of which might have seen the input data) while meeting the given delay threshold. Although conceptually simple, the DPC protocol tolerates the occurrence of multiple simultaneous failures as well as any further failures that occur during recovery.This article describes DPC and its implementation in the Borealis SPE. We show that DPC enables a distributed SPE to maintain low-latency processing at all times, while also achieving eventual consistency, where applications eventually receive the complete and correct output streams. Furthermore, we show that, independent of system size and failure location, it is possible to handle failures almost up-to the user-specified bound in a manner that meets the required availability without introducing any inconsistency.
Fast Polyhedral Adaptive Conjoint Estimation

We propose and test new adaptive question design and estimation algorithms for partial profile conjoint analysis. Polyhedral question design focuses questions to reduce a feasible set of parameters as rapidly as possible. Analytic center estimation uses a centrality criterion based on consistency with respondents' answers. Both algorithms run with no noticeable delay between questions. We evaluate the proposed methods relative to established benchmarks for question design random selection, D-efficient designs, adaptive conjoint analysis and estimation hierarchical Bayes. Monte Carlo simulations vary respondent heterogeneity and response errors. For low numbers of questions, polyhedral question design does best or is tied for best for all tested domains. For high numbers of questions, efficient fixed designs do better in some domains. Analytic center estimation shows promise for high heterogeneity and for low response errors; hierarchical Bayes for low heterogeneity and high response errors. Other simulations evaluate hybrid methods, which include self-explicated data. A field test 330 respondents compared methods on both internal validity holdout tasks and external validity actual choice of a laptop bag worth approximately $100. The field test is consistent with the simulation results and offers strong support for polyhedral question design. In addition, marketplace sales were consistent with conjoint-analysis predictions.
The IBM and Microsoft Cases: What's the Difference?

The Microsoft case has attracted more attention than perhaps any antitrust case in history - far more than the mammoth IBM case of the 1970's, with which it is sometimes compared. I was the chief economics witness for IBM in U.S. v. IBM and the chief economics witness for the United States in U.S. v. Microsoft. I did not "switch sides". Even though both cases involved "bundling" and charges of "monopoly leveraging", the facts were different, and the principles of economic analysis led to different outcomes. In particular, Microsoft's actions did what IBM's could not have done -- excluded competitors by protecting an important barrier to entry into the market in which it held monopoly power.
Quasiconvexity and Amalgams

We obtain a criterion for quasiconvexity of a subgroup of an amalgamated free product of two word hyperbolic groups along a virtually cyclic subgroup. The result provides a method of constructing new word hyperbolic group in class (Q), that is such that all their finitely generated subgroups are quasiconvex. It is known that free groups, hyperbolic surface groups and most 3-dimensional Kleinian groups have property (Q). We also give some applications of our results to one-relator groups and exponential groups.
Tandem Nucleophilic Addition/Fragmentation Reactions and Synthetic Versatility of Vinylogous Acyl Triflates

A thorough analysis of the chemistry of vinylogous acyl triflates provides insight into important chemical processes and opens new directions in synthetic technology. Tandem nucleophilic addition/C−C bond cleaving fragmentation reactions of cyclic vinylogous acyl triflates 1 yield a variety of acyclic acetylenic compounds. Full details are disclosed herein. A wide array of nucleophiles, such as organolithium and Grignard reagents, lithium enolates and their analogues, hydride reagents, and lithium amides, are applied. The respective reactions produce ketones 2, 1,3-diketones and their analogues 3, alcohols 4, and amides 5. The present reactions are proposed to proceed through a 1,2-addition of the nucleophile to the carbonyl group of starting triflates 1 to form tetrahedral alkoxide intermediates C, followed by Grob-type fragmentation, which effects C−C bond cleavage to yield acyclic acetylenic compounds 2−5 and 7. The potent nucleofugacity of the triflate moiety is channeled through the σ-bond framework ...
The use of reconsent in a national evaluation of adolescent reproductive health programs.

Abstract Purpose Reconsent involves asking research participants to reaffirm their consent for study participation when there have been significant changes in the study's procedures, risks, or benefits. We described the reconsent process, identified the reconsent rate, and examined the comparability of youths enrolled via consent and reconsent in a national evaluation of adolescent reproductive health programs. Methods Evaluation participants from five abstinence education projects (N = 2,176) and nine projects serving pregnant or parenting adolescents (N = 878) provided either parent or youth consent or reconsent to participate in the national evaluation. Participants completed surveys that included demographic characteristics; sexual intentions, norms and behaviors; and pregnancy history. Multivariate logistic regression was used to examine associations between consent status, demographic characteristics, and risk indicators. Results The reconsent rates in the abstinence education and pregnant or parenting samples were 45% and 58%, respectively. Participant's age was positively associated with reconsent. Hispanic adolescents (and, for abstinence education, other racial/ethnic minorities) were underrepresented among youth with reconsent. Among abstinence education study participants, risk indicators were not associated with consent status. Among pregnant or parenting teens, those who had experienced repeat pregnancy were less likely than those who had experienced only one pregnancy to have been enrolled via reconsent. Conclusions Reconsent can bolster sample size but may introduce bias by missing some racial/ethnic and age-groups. Among high-risk adolescents, reconsent may also yield a sample that differs from consented samples on risk characteristics, necessitating statistical adjustments when analyzing data.
The Destruction of Bars by Central Mass Concentrations

More than two-thirds of disk galaxies are barred to some degree. Many today harbor massive concentrations of gas in their centers, and some are known to possess supermassive black holes (SMBHs) and their associated stellar cusps. Previous theoretical work has suggested that a bar in a galaxy could be dissolved by the formation of a mass concentration in the center, although the precise mass and degree of central concentration required is not well established. We report an extensive study of the effects of central masses on bars in high-quality N-body simulations of galaxies. We have varied the growth rate of the central mass, its final mass, and its degree of concentration to examine how these factors affect the evolution of the bar. Our main conclusions are the following: (1) Bars are more robust than previously thought. The central mass has to be as large as several percent of the disk mass to completely destroy the bar on a short timescale. (2) For a given mass, dense objects cause the greatest reduction in bar amplitude, while significantly more diffuse objects have a lesser effect. (3) The bar amplitude always decreases as the central mass is grown and continues to decay thereafter on a cosmological timescale. (4) The first phase of bar weakening is due to the destruction by the central mass concentration (CMC) of lower energy, bar-supporting orbits, while the second phase is a consequence of secular changes to the global potential that further diminish the number of bar-supporting orbits. We provide detailed phase-space and orbit analysis to support this suggestion. Thus, current masses of SMBHs are probably too small, even when dressed with a stellar cusp, to affect the bars in their host galaxies. The molecular gas concentrations found in some barred galaxies are also too diffuse to affect the amplitude of the bar significantly. These findings reconcile the apparent high percentage of barred galaxies with the presence of CMCs and have important implications for the formation and survival of bars in such galaxies.
Reactions of alkynes with metallaboranes : Novel reactivities lead to new structure types

The reactions of alkynes with nido-dimetallaboranes containing monocyclopenta- dienyl metal fragments are highly dependent on metal identity. Typical metals from groups 6 and 7 do not react under mild conditions, Rh gives exclusively alkyne cyclotrimerization via a cluster-catalyzed reaction, and Ru reacts predominantly via insertion to give new ruthenacarborane clusters. The facile reaction observed for Ru permits the characterization of intermediates exhibiting novel structural features, e.g., external cluster-bridging mono- borane or alkylidene fragments. Despite the large differences in reactivity, circumstantial ev- idence suggests the alkyne adds to and opens the metallaborane to an arachno-structure. The metal present determines the character of the metallaborane, which in turn determines whether further reaction occurs. For Ru, it is the hydrogen-rich character fostered by the metal fragment that leads to the copious chemistry observed.
Electro-optic phase modulation in a silica channel waveguide

We report what is to our knowledge the first demonstration of electro-optic phase modulation in a fused-silica channel waveguide. The no linearity is induced through elevated temperature poling of an electron-beam-irradiated waveguide. A phase shift of 32 mrad was measured at λ = 633 nm for a device interaction length of 4.8 mm and an applied electric field of 7.3 V/μm.
Ionized Gas In The Galactic Center: New Observations And Interpretation

We present new observations of the [Ne II] emission from the ionized gas in Sgr A West with improved resolution and sensitivity. About half of the emission comes from gas with kinematics indicating it is orbiting in a plane tipped about 25? from the Galactic plane. This plane is consistent with that derived previously for the circumnuclear molecular disk and the northern arm and western arc ionized features. However, unlike most previous studies, we conclude that the ionized gas is not moving along the ionized features, but on more nearly circular paths. The observed speeds are close to, but probably somewhat less than expected for orbital motions in the potential of the central black hole and stars and have a small inward component. The spatial distribution of the emission is well fitted by a spiral pattern. We discuss possible physical explanations for the spatial distribution and kinematics of the ionized gas, and conclude that both may be best explained by a one-armed spiral density wave, which also accounts for both the observed low velocities and the inward velocity component. We suggest that a density wave may result from the precession of elliptical orbits in the potential of the black hole and stellar mass distribution.
Fast Neutrons: Generation, Dosimetry, and Applications

We have designed a neutron source based on the 7Li(p,n)7 Bereaction. We bombard a thick metallic lithium target with protons from the Lowell type CN Van-de Graaff accelerator, and we obtain neutrons in the 5 keV to 3 MeV range with fluences up to 2×1014 neutrons/ (cm2h). We discuss source design and neutron dosimetry and we give examples of applications.
An algorithm for haplotype analysis

This paper proposes an algorithm for haplotype analysis based on a Monte Carlo method. Haplotype configurations are generated according to the distribution of joint haplotypes of individuals in a pedigree given their phenotype data, via a Markov chain Monte Carlo algorithm. The haplotype configuration which maximizes this conditional probability distribution can thus be estimated. In addition, the set of haplotype configurations with relatively high probabilities can also be estimated as possible alternatives to the most probable one. This flexibility enables geneticists to choose the haplotype configurations which are most reasonable to them, allowing them to include their knowledge of the data under analysis. 18 refs., 2 figs., 1 tab.
GEOMETRICALLY INDUCED NONLINEAR DYNAMICS IN ONE-DIMENSIONAL LATTICES

We present a simple lattice model consisting of a chain of coupled oscillators, where their masses are interconnected by linear springs and allowed to move along a common axis, as in a monorail. In the transverse direction each mass is also attached to two other springs, one on each side of the mass. The ends of these springs are kept at fixed positions. The nonlinearity in the model arises from the geometric constraints imposed on the motion of the masses, as well as from the configuration of the springs, where in the transverse directions the springs are either in the extended or compressed state depending on the position of the mass. Under these conditions we show that solitary waves (domain walls) are present in the system. In the long wavelength limit an analytical solution for these nonlinear waves is found. Numerical integrations of the equations of motion in the full discrete system are also performed to analyze the stability of the domain wall solution. Nonlinear supratransmission is also shown to exist in the model and a discussion of mechanism is presented.
Mean and Fluctuating Electron Density in Equilibrium Turbulent Boundary Layers

A simplified analysis is used to predict the mean and fluctuating electron density profiles in equilibrium high-speed turbulent boundary layers. The analysis is based on the application of nonlinear statistics to equilibrium chemistry and experimentally determined turbulence characteristics. Closed-form solutions of the electron density fluctuations are obtained for typical statistical distribution functions of the gas temperature fluctuations. The temperature dependence of the electron density is determined from complete thermochemical equilibrium calculations and the results are fit to a form of the Saha equation. Results are presented for reacting turbulent boundary layers consisting of clean air, Teflon/air mixtures, and phenolic carbon/air mixtures. It is shown that the true mean electron density can be orders-of-magnitude greater than the value computed at the local mean temperature. In addition, the root-mean-square electron density fluctuation can greatly exceed the true mean value.
Conceptual Design of a Lift Fan Plus Lift/Cruise Fighter Aircraft

Results of a design synthesis and mission analysis of a supersonic VTOL fighter aircraft are presented. Propulsive lift is provided by a single turbotip-driven lift fan and deflected thrust from a high performance turbofan cruise engine fitted with an afterburner for supersonic flight. The inlet and thrust diverter in the main engine tail-pipe are seen to be the principal design problems. V/STOL and supersonic design tradeoffs are addressed in lift fan sizing and placement, reaction and aerodynamic control sizing, fuselage volume requirements, and area ruling. Range and turn rate are used as figures of merit.-
Equine Metabolic Syndrome

The concept of an equine metabolic syndrome (EMS) was first proposed in 2002. This concept has developed over time, and EMS was recently described in a consensus statement released by the American College of Veterinary Internal Medicine. In human medicine, metabolic syndrome (MetS) refers to a set of risk factors that predict the risk of cardiovascular disease, including obesity, glucose intolerance and insulin resistance (IR), dyslipidemia, microalbuminuria, and hypertension. EMS shares some of the features of MetS, including increased adiposity, hyperinsulinemia, IR, but differs in that laminitis is the primary disease of interest.
Why geoengineering is not a ‘global public good’, and why it is ethically misleading to frame it as one

In early policy work, climate engineering is often described as a global public good. This paper argues that the paradigm example of geoengineering—stratospheric sulfate injection (hereafter ‘SSI’)—does not fit the canonical technical definition of a global public good, and that more relaxed versions are unhelpful. More importantly, it claims that, regardless of the technicalities, the public good framing is seriously misleading, in part because it arbitrarily marginalizes ethical concerns. Both points suggest that more clarity is needed about the aims of geoengineering policy—and especially governance—and that this requires special attention to ethics.
Differential modulation based on quasi-orthogonal codes

This paper proposes a differential modulation scheme based on quasi-orthogonal space-time block codes (STBCs) when neither the transmitter nor the receiver has knowledge of the channel. A system with four transmit antennas is considered and divided into two subsystems. Each subsystem is equivalent to a system with two transmit antennas and uses differential STBC modulation. Based on the encoding and decoding for the two subsystems, the overall encoding and decoding algorithm for the original system is derived. We also compare the performance of our differential detection with that of the corresponding coherent detection in terms of achieved signal-to-noise ratio (SNR) for a given transmission power and propose a quantitative measure to estimate the performance difference between the coherent quasi-orthogonal code and our differential detection. Furthermore, we show that our differential modulation scheme can be extended to a system with more than four transmit antennas. Compared with the existing differential modulation schemes for four and eight transmit antennas, the proposed scheme has a lower bit-error rate (BER) and provides full diversity and pair-wise decoding complexity.
Real and imagined barriers to college entry: Perceptions of cost

Abstract Patterns of postsecondary attendance in the United States continue to be stratified by socioeconomic background and race/ethnicity. We suggest that inequalities in knowledge of the costs of going to college contribute to persistent patterns of stratification. We hypothesize that disadvantaged parents who believe their child will attend college are less certain of the costs of college attendance than more advantaged parents. As a result, they are less able or willing to provide an estimate of the costs of college attendance, more likely to over-estimate those costs if they do provide an estimate, and more likely to make larger errors in estimation than comparable middle-class or white parents. Using nationally representative data, we find mixed support for these hypotheses. Socioeconomically disadvantaged parents and minority parents are less likely to provide estimates of college tuition and, when they provide estimates, tend to make larger errors. On average, though, parents provide upwardly biased estimates of cost that are uniform across race, ethnicity and socioeconomic status. We discuss implications of these findings for sociological theory and for inequality in postsecondary education.
Status of the MiniBooNE Experiment

The MiniBooNE E–898 experiment at Fermilab has been designed to confirm or dismiss the LSND result by looking for ν e appearance in a ν μ beam. The experiment began taking beam in September 2002. Here we describe the experiment, the first neutrino candidate events, and our expected sensitivity to a neutrino oscillation signal.
Python Unleashed on Systems Biology

Researchers at Cornell University have built an open source software system to model biomolecular reaction networks. SloppyCell is written in Python and uses third-party libraries extensively, but it also does some fun things with on-the-fly code generation and parallel programming.
A CHARACTERISTIC DIVISION BETWEEN THE FUELING OF QUASARS AND SEYFERTS: FIVE SIMPLE TESTS

Given the existence of the M BH-σ relation, models of self-regulated black hole (BH) growth require both a fuel supply and concomitant growth of the host bulge to deepen the central potential, or else the system will either starve or immediately self-regulate without any sustained activity. This leads to a generic prediction that the brightest quasars must be triggered in major mergers: a large fraction of the galaxy mass must be added/converted to new bulge mass and a galactic supply of gas must lose angular momentum in less than a dynamical time. Low-luminosity active galactic nuclei, in contrast, require little bulge growth and small gas supplies, and could be triggered in more common nonmerger events. This leads to the expectation of a characteristic transition to merger-induced fueling around the traditional quasar-Seyfert luminosity division (growth of BH masses above/below ~107 M ☉). We compile and survey a number of observations in order to test several predictions of such a division, including (1) a transition to bulge-dominated hosts (which any major merger remnant, regardless of difficult-to-observe tidal features, should be). (2) A transition between pseudobulges and classical bulges hosting the remnant BHs: pseudobulges are formed in secular processes and minor mergers, whereas classical bulges are relics of major mergers. (3) An increase in the amplitude of small-scale clustering (increased halo occupation of small group environments) where mergers are more efficient. (4) Different redshift evolution, with gas-rich merger rates rising to redshifts z > 2 while secular processes are relatively constant in time. (5) An increasing prominence of post-starburst features in more luminous systems. Our compilation of observations in each of these areas provides tentative evidence for the predicted division around the Seyfert-quasar threshold, and we discuss how future observations can improve these constraints and, in combination with the tests here, break degeneracies between different fueling models.
Car ownership and welfare-to-work

This study examines the role of car ownership in facilitating employment among recipients under the current welfare-to-work law. Because of a potential problem with simultaneity, the analysis uses an instrumental variable constructed from insurance premiums and population density for car ownership. The data comes from a 1999-2000 survey of TANF recipients in the Los Angeles metropolitan area. The empirical results show a significant independent contribution of car ownership on employment. The presence of an observed ownership is associated with 12 percentage point increase in the odds of being employed. Moreover, the results indicate that lowering insurance premiums by $100 can increase the odds of employment by 4 percentage points.
Next linear collider test accelerator injector upgrade

Abstract The Next Linear Collider Test Accelerator (NLCTA) being built at SLAC will integrate the new technologies of X-band accelerator structures and RF systems for the next linear collider, demonstrate multibranch beam-loading energy compensation and suppression of higher-order deflecting modes, and measure the dark current generated by RF field emission in the accelerator [NLC Test Accelerator Conceptual Design Report, SLAC Report 411, August 1993]. The current injector being constructed for phase 1 of the NLCTA tests is a simple injector consisting of a gun with a 150 ns long pulse and X-band bunching and accelerating system [A.D. Yeremian, R.H. Miller and J.W. Wang, Proc. LINAC 94 Conf. Tsukuba, Japan, 1994, p. 89]. While the injector will provide average currents comparable to what is needed for NLC it will not provide the bunch structure since every X-band RF bucket will be filled. The injector upgrade will produce a similar bunch train as planned for NLC, mainly a train of bunches 1.4 ns apart with 3 nC in each bunch. The current design for this injector is discussed.
Safety belt effectiveness in preventing driver fatalities versus a number of vehicular, accident, roadway, and environmental factors

Safety belt effectiveness in preventing fatalities to drivers is examined versus a number factors (vehicle, accident, and environmental) by applying the double-pair comparison method to appropriate subsets of the Fatal Accident Reporting System (FARS) data. For each of 13 factors studied, safety belt effectiveness (the percent of fatally injured unbelted drivers who would not have been killed if they had been wearing safety belts) is estimated, as is an associated standard error of the estimate. The results, which are presented graphically, provide no evidence that safety belt effectiveness is systematically influenced by most of the factors investigated, including car mass and model year. The absence of any systematic relationship with car mass is in agreement with an earlier finding based on the pedestrian fatality exposure method; this agreement adds plausibility to the assumptions used for both the earlier and the present methods. Safety belt effectiveness is greater for single-car crashes (62 ± 5) % than for crashes involving two cars (30 ± 8) % , this difference being statistically significant at p<.02. The results suggest weakly that safety belt effectiveness is greater for two-door (48 ± 6) % than for four-door (38 ± 10) % cars, and is greater for striking (44 ± 6) % cars than for struck (27 ± 12)% cars. The above differences probably reflect higher effectiveness in frontal (or rollover) crashes than in side impacts.
Do states optimize? Public capital and economic growth

This paper develops a non-linear theoretical relationship between public capital and economic growth in order to obtain estimates of the growth-maximizing ratio of public capital to private capital. The model is empirically implemented using data on the 48 contiguous U.S. states over the period 1970 to 1990. The empirical results provide evidence that (i) the relationship between public capital and economic growth is non-linear, (ii) the growth-maximizing public capital stock is approximately 60% to 80% as large as the private (tangible) capital stock, and (iii) permanent changes in public capital are associated with permanent changes in economic growth.
The strange case of eugenics: A subject's ontogeny in a long-lived classification scheme and the question of collocative integrity

This article introduces the problem of collocative integrity present in long-lived classification schemes that undergo several changes. A case study of the subject “eugenics” in the Dewey Decimal Classification is presented to illustrate this phenomenon. Eugenics is strange because of the kinds of changes it undergoes. The article closes with a discussion of subject ontogeny as the name for this phenomenon and describes implications for information searching and browsing. © 2012 Wiley Periodicals, Inc.
Are X-ray clusters cooled by heat conduction to the surrounding intergalactic medium?

Abstract We show that X-ray clusters would have cooled substantially over a Hubble time by transport of heat from their hot interior to the their envelope, if the heat conductivity had not been heavily suppressed relative to the Spitzer value due to magnetic fields. The suppression is required in order for the observed abundance of hot X-ray clusters to be consistent with predictions from popular cosmological models. If a similar or stronger suppression factor applies to cluster cores, then thermal conduction cannot be the mechanism that prevents cooling flows there.
Thermoremanent magnetization (TRM) of lunar samples

The TRM of the lunar breccia 10048-55 and the crystalline rocks 12053-47 and 14053-48 have been investigated. TRM is acquired linearly by 12053-47 and 10048-55 in fields of 100γ to 1 oe. In contrast, the TRM of 14053-48 departs from linearity in the same range of fields. The AF stability of TRM acquired by the samples varies markedly. 10048-55 and 12053-47 are of intermediate hardness, such as would be expected for a TRM carried at least in part by fine grain particles of iron having high coercivity. 14053-48 has extremely soft TRM which is most probably carried predominantly by multidomain iron. Thermal demagnetization of the TRM of 10048-55 revealed well distributed blocking temperatures, but the TRM of 14053-48 has markedly bimodal blocking temperatures. Comparison of the characteristics of the NRM and the TRM of the three samples suggest that only the NRM of 14053-48 is likely to be primarily thermal in origin.
On the Rapid Collapse and Evolution of Molecular Clouds

Stars generally form faster than the ambipolar diffusion time, suggesting that several processes short-circuit the delay and promote a rapid collapse. These processes are considered here, including turbulence compression in the outer parts of giant molecular cloud (GMC) cores and GMC envelopes, GMC core formation in an initially supercritical state, and compression-induced triggering in dispersing GMC envelopes. The classical issues related to star formation timescales are addressed: high molecular fractions, low efficiencies, long consumption times for CO and HCN, rapid GMC core disruption and the lack of a stable core, long absolute but short relative timescales with accelerated star formation, and the slow motions of protostars. We consider stimuli to collapse from changes in the density dependence of the ionization fraction, the cosmic ray ionization rate, and various dust properties at densities above ~105 cm-3. We favor the standard model of subcritical GMC envelops and suggest they would be long-lived if not for disruption by rapid star formation in GMC cores. The lifecycle of GMCs is illustrated by a spiral arm section in the Hubble Heritage image of M51, showing GMC formation, star formation, GMC disruption with lingering triggered star formation, and envelope dispersal. There is no delay between spiral arm dust lanes and star formation; the classical notion results from heavy extinction in the dust lane and triggered star formation during cloud dispersal. Differences in the IMF for the different modes of star formation are considered.