cssi/SciSciGPT-SciSciNet huggingface dataset:
Waveform search for the innermost inner core

Abstract Waveforms of the PKIKP seismic phase are inconsistent with the effects of a sharp boundary at 300 km radius of an inner-most inner core. Seismograms synthesized for the distance range 150° to 180° in models having a discontinuity at 300 km radius in the inner core exhibit focused diffractions around the innermost sphere at antipodal range that are inconsistent with observed PKIKP waveforms. A few examples, however, can be found of PKIKP complexity near 165°, consistent with a triplication created by a 475 km radius discontinuity. A rapid change in the magnitude and variance of seismic attenuation of PKIKP whose rays turn between 400 and 600 km radius is also observed, consistent with an innermost sphere of low, regionally uniform, seismic attenuation. Models predicting waveforms in agreement with observed waveforms have either a transition in elastic and anelastic properties spread over a depth interval greater than 100 km or an innermost sphere of differing elastic properties that exceeds 450 km radius. The weak but suggestive evidence for an innermost inner core may simply represent a transition in fabric, spread over 100 km or more, centered near 500 km radius. This change may signify the end stage of solidification, flow and re-crystallization, resulting in the highest ordering and largest grain sizes of intrinsically anisotropic crystals.
Dilute Bose gases interacting via power-law potentials

Neutral atoms interact through a van der Waals potential which asymptotically falls off as ${r}^{\ensuremath{-}6}$. In ultracold gases, this interaction can be described to a good approximation by the atom-atom scattering length. However, corrections arise that depend on the characteristic length of the van der Waals potential. We parametrize these corrections by analyzing the energies of two- and few-atom systems under external harmonic confinement, obtained by numerically and analytically solving the Schr\"odinger equation. We generalize our results to particles interacting through a longer-ranged potential which asymptotically falls off as ${r}^{\ensuremath{-}4}$.
Photoluminescence-detected magnetic resonance (PLDMR) studies of matrix isolated molecules and films of C60 and C70

Abstract The X-band spin 1 2 photoluminescence-detected magnetic resonance (PLDMR) of C60 and C70 isolated in a toluene/polystyrene matrix and various films is reviewed. The fluorescence (F)-enhancing triplet resonances of the isolated molecules are attributed to ground-state repopulation by a nonradiative triplet state delocalized over the molecule. The phosphorescence-detected resonance of C70 glasses is due to the direct radiative decay of the long-lived triplets. Its strong temperature dependence results apparently from a dynamic Jahn-Teller effect. The PLDMR of C60 and C70 films is similar, and includes a narrow F-enhancing spin 1 2 resonance (ΔH 1 2 ∼8G) at g∼2.0025 and narrow and broad triplet patterns at full- and half-fields. The spin 1 2 resonance is discussed in relation to polaron recombination or a radical-triplet pair mechanism. The narrow triplet pattern, attributed to a triplet delocalized over the molecule, is slightly narrower than in C60, consistent with a slightly larger exciton. The broad pattern is similar to that observed in π-conjugated polymers and is believed to result from a triplet localized on a pentagon or hexagon adjacent to a neighboring molecule.
CONSTANT RADIAL THRUST ACCELERATION REDUX

The effect of a constant radial thrust acceleration on a spacecraft in circular orbit in the two-body problem is revisited. The critical value at which escape occurs is rederived using the concept of a potential energy well that includes the effects of both the gravitational force and the thrust. A new, closedform expression is obtained for the amplitude of the radial orbital oscillation if escape does not occur. The use of a constant radial thrust acceleration to shift the radius of a circular orbit of specified period is investigated. A solar sail is discussed as a possible source of this thrust acceleration.
Enantioselective Dichlorination of Allylic Alcohols

The development of an enantioselective allylic alcohol dichlorination catalyzed by dimeric cinchona alkaloid derivatives and employing aryl iododichlorides as chlorine sources is reported. Reaction optimization, exploration of the substrate scope, and a model for stereoinduction are presented.
Essentially all Gaussian two-party quantum states are a priori nonclassical but classically correlated

Duan et al (Duan L-M, Giedke G, Cirac J I and Zoller P 2000 Phys. Rev. Lett. 84 2722) and, independently, Simon (Simon R 2000 Phys. Rev. Lett. 84 2726) have recently found necessary and sufficient conditions for the separability (classical correlation) of the Gaussian two-party (continuous variable) states. Duan et al remark that their criterion is based on a `much stronger bound' on the total variance of a pair of Einstein-Podolsky-Rosen-type operators than is required simply by the uncertainty relation. Here, we seek to formalize and test this particular assertion in both classical and quantum-theoretic frameworks. We first attach to these states the classical a priori probability (Jeffreys' prior), proportional to the volume element of the Fisher information metric on the Riemannian manifold of Gaussian (quadrivariate normal) probability distributions. Then, numerical evidence indicates that more than 99% of the Gaussian two-party states do, in fact, meet the more stringent criterion for separability. We collaterally note that the prior probability assigned to the classical states, that is those having positive Glauber-Sudarshan P-representations, is less than 0.001%. We, then, seek to attach as a measure to the Gaussian two-party states the volume element of the associated (quantum-theoretic) Bures (minimal monotone) metric. Our several extensive analyses, then, persistently yield probabilities of separability and classicality that are, to very high orders of accuracy, unity and zero, respectively, so the two quite distinct (classical and quantum-theoretic) forms of analysis are rather remarkably consistent in their findings.
Impact on global warming of development and structural changes in the electricity sector of Guangdong Province, China☆

Abstract Studies of China's energy development and carbon trading opportunities under CDM using aggregate approaches often face two kinds of difficulties: regional variations and economic and institutional constraints faced by decision makers at the sub-national level that are hard to model. This study initiates research that disaggregates the recent development of the Chinese electricity industry in a case study of Guangdong Province. We highlight a bifurcated development of efficient and inefficient generation technologies in the past 10 years, and link it to the institutional arrangements for electricity supply, inadequate financial markets and specific policy incentives. We also find, using Guangdong data, that carbon emissions from the Guangdong electricity generation follows a declining trend from 0.29 million tons per TWh in 1990 to 0.24 in 1998, with a planned level of 0.20 million tons in 2010. An attempt to derive a shadow price of carbon by correlating heat rates with unit costs of generation shows some problems in the cost data. In light of the CDM baseline discussions, our study suggests that credible and cost-effective baselines in Chinese power will demand disaggregation along vectors of regions and technologies, and require an understanding of economic and institutional characteristics of energy decision making.
Use of organometallic complexes of ruthenium in the Lewis acid catalyzed hetero Diels-Alder reaction

Abstract The hetero Diels-Alder reaction between benzaldehyde and a functionalized diene can be catalyzed by the Lewis acid transition metal complexes, [CpRuLL′(CH2 CH2)]PF6 (L L′ PPh3, or LL′ = 1,2-bis-diphenylphosphinoethane, (−)-DIOP or (S,S)-CHIRAPHOS).
A finite mass based method for Vlasov-Poisson simulations

A method for the numerical simulation of plasma dynamics using discrete particles is introduced. The shape function kinetics (SFK) method is based on decomposing the mass into discrete particles using shape functions of compact support. The particle positions and shape evolve in response to internal velocity spread and external forces. Remapping is necessary in order to maintain accuracy and two strategies for remapping the particles are discussed. Numerical simulations of standard test problems illustrate the advantages of the method which include very low noise compared to the standard particle-in-cell technique, inherent positivity, large dynamic range, and ease of implementation.
Human polymorphonuclear-leukocyte inhibition of incorporation of chitin precursors into Mycelia of Coccidioides immitis

Human polymorphonuclear leukocytes (PMNLs), when added to arthroconidial suspensions of Coccidioides immitis, markedly inhibit fungal incorporation of the cell-wall precursor N-acetylglucosamine. This effect does not require serum but is facilitated by a heat-labile serum component(s), probably by promoting PMNL attachment to the arthroconidia. Inhibition is entirely reversible within 24 hr. In parallel with this finding, PMNLs exhibited virtually no killing of arthroconidia and (as determined by electron microscopy) did not produce damage to the fungal ultrastructure. PMNLs from a patient with chronic granulomatous disease suppressed fungal incorporation of N-acetyl-glucosamine by only 0%-22% under various conditions, as compared with 54%-85% suppression by PMNLs from normal donors. Our studies demonstrate that PMNLs can influence the metabolism of C immitis and raise the possibility that their presence in coccidioidal histopathology may be an important immediate host defense in limiting progression early after infection.
Universal deformation rings need not be complete intersections

We answer a question of M. Flach by showing that there is a linear representation of a profinite group whose (unrestricted) universal deformation ring is not a complete intersection. We show that such examples arise in arithmetic in the following way. There are infinitely many real quadratic fields F for which there is a mod 2 representation of the Galois group of the maximal unramified extension of F whose universal deformation ring is not a complete intersection. Finally, we discuss bounds on the singularities of universal deformation rings of representations of finite groups in terms of the nilpotency of the associated defect groups.
Association of severe vertebral fractures with reduced quality of life: reduction in the incidence of severe vertebral fractures by teriparatide.

Objective The association between vertebral fracture severity and health-related quality of life (HRQOL) was investigated in a subset of patients in the Fracture Prevention Trial. We sought to determine whether vertebral fracture severity was associated with HRQOL scores, and if so, to determine the effects of teriparatide (recombinant human parathyroid hormone 1-34) on vertebral fracture grades that most strongly impact HRQOL in postmenopausal women with osteoporosis. Methods Vertebral fracture severity was assessed by the visual semiquantitative (SQ) method. A subset of 444 patients with a baseline radiograph completed the Osteoporosis Assessment Questionnaire. Baseline HRQOL scores were modeled as a function of maximum baseline vertebral fracture grade, while controlling for age, bone mineral density, body mass index, and back pain. Results The effect of baseline vertebral fracture grade on baseline HRQOL was statistically significant, while interactions between vertebral fracture grade and the other variables were not statistically significant. SQ grade 3 (SQ3) vertebral fractures were associated with a significantly lower overall HRQOL score and with significantly lower physical function, symptoms, and emotional status dimension scores. After a median of 19 months of therapy, new or worsening SQ3 vertebral fractures occurred in 21 of 448 patients (4.7%) in the placebo group compared with 3 of 444 patients (0.7%) in the 20 μg/day teriparatide group. The risk of developing a new or worsened SQ3 vertebral fracture was reduced by 86% (P < 0.001) in patients treated with 20 μg/day teriparatide. Conclusion Compared with prevalent fractures of lesser severity, SQ3 vertebral fractures were associated with reduced HRQOL. Teriparatide treatment significantly reduced the risk of new or worsening SQ3 vertebral fractures. These findings suggest, but do not directly demonstrate, a benefit of teriparatide on HRQOL.
Prognostic Utility of Hyams Histological Grading and Kadish-Morita Staging Systems for Esthesioneuroblastoma Outcomes

Esthesioneuroblastoma (ENB) is derived from the specialized olfactory neuroepithelium. Hyams grading and Kadish staging have been used to prognosticate and to guide treatment decisions. In this study, we sought to validate the prognostic utility of these systems in a large ENB cohort. We retrospectively analyzed the records of patients with ENB who had been evaluated and treated at our institution. The association of grade and stage with prognostic outcome was assessed; the Kaplan–Meier estimator was used to generate 5-year OS and DFS curves. Out of 124 cases we identified, 121 were assessed for grading and 109 for staging. Review of the tissue samples revealed that 62 % of tumors were low grade (I/II) and 21 % were high grade (III/IV); 17 % of tumors were metastasis. The OS rate was 75 % at 5 years. The DFS was 60 % at 5 years. The OS was significantly worse for metastatic ENB (low-grade ENB vs metastatic ENB p = 0.01598); the DFS was significantly worse for high grade versus low grade ENB. Of the 109 cases that had been staged, 16 % were stage A, 33 % stage B, 43 % stage C, and 8 % stage D. In the A, B, and C groups, there were no significant differences between recurrence, distant metastasis, or 5-year survival rates. Statistical significance was not reached with the T, N, M and overall staging system. Age cutoff of 65 years reliably predicted OS. High grade of ENB was significantly associated with poor outcome, while advanced stage was not associated with poor outcome in this large cohort. Grading should certainly be considered in prognostication and treatment decisions for ENB.
Do Small Firms Benefit from Auditor Attestation of Internal Control Effectiveness

SUMMARY: While auditor attestation of the effectiveness of internal control over financial reporting (ICFR) is required for firms with a public float of at least $75 million (accelerated filers), the Securities and Exchange Commission (SEC) has delayed auditor attestation for non-accelerated filers several times. The Dodd-Frank Act of 2010 exempts non-accelerated filers from auditor attestation. We examine the relation between auditor attestation and revenue quality for a sample of non-accelerated filers and small accelerated filers. We find that discretionary (abnormal) revenues, our proxy for revenue quality, are lower by about 1.5 percent of total assets for accelerated filers relative to non-accelerated filers. This finding holds even among firms whose management has certified their ICFR to be effective. Overall, the findings support the notion that auditor attestation of the effectiveness of ICFR benefits small accelerated filers via higher revenue quality. We believe our findings are timely and pote...
Evaluating the availability of gallium, indium, and tellurium from recycled photovoltaic modules

The use of thin-film copper indium gallium (di)selenide (CIGS) and cadmium-telluride (CdTe) in solar technologies has grown rapidly in recent years, leading to an increased demand for gallium, indium, and tellurium. In the coming years, recycling these elements from end-of-life photovoltaic (PV) modules may be an important part of their overall supply, but little is known about the economic feasibility and the potential quantities available. This article investigates the future role of PV recycling in supplying gallium, indium, and tellurium. The authors evaluate both the quantities available from recycling over the next century and the associated costs for recycling modules and reusing each mineral in PV manufacturing. The findings indicate that, in terms of technical potential, there may be significant quantities of each mineral potentially available from recycling CIGS and CdTe modules. In terms of costs, recovering each element from end-of-life PV modules and reusing it in PV manufacturing is estimated to cost more than the current raw mineral costs. These findings help improve the understanding of recycling's role in enabling higher levels of CIGS and CdTe cell production.
Health and Human Rights

When the World Health Organisation redefined health as “a state of complete physical, mental and social well-being”1 it not only expanded health far beyond medicine, it openly acknowledged the vast accumulated knowledge about the central role of societal determinants of population health. Despite the public's belief to the contrary, medical care is a relatively minor, albeit important, contributor to health,2 far outweighed by societal factors, of which social class has been the most extensively studied.3 4 In 1988, a seminal report by the United States Institute of Medicine defined the mission of public health as “ensuring the conditions in which people can be healthy.”4 In turn, this required those working in public health to consider the societal nature of these essential conditions in which people could achieve the highest attainable standard of physical, mental, and social wellbeing. Paradoxically, the discipline of public health has generally ignored the societal roots of health in favour of medical interventions, which operate further downstream. For example, public health efforts at preventing and …
Design space for low sensitivity to size variations in [110] PMOS nanowire devices: the implications of anisotropy in the quantization mass.

A 20-band sp3d5s* spin−orbit-coupled, semiempirical, atomistic tight-binding model is used with a semiclassical, ballistic, field effect transistor (FET) model, to examine the ON-current variations to size variations of [110]-oriented PMOS nanowire devices. Infinitely long, uniform, rectangular nanowires of side dimensions from 3 to 12 nm are examined and significantly different behavior in width versus height variations are identified and explained. Design regions are identified, which show minor ON-current variations to significant width variations that might occur due to lack of line width control. Regions which show large ON-current variations to small height variations are also identified. The considerations of the full band model here show that ON-current doubling can be observed in the ON-state at the onset of volume inversion to surface inversion transport caused by structural side size variations. Strain engineering can smooth out or tune such sensitivities to size variations. The cause of variat...
Entitlements analysis : relating concepts and contexts

textabstractSen's entitlements approach has attracted much attention and imitation, including attempted extensions beyond its original context in the explanation of famines. It has evolved in various ways as it is applied to new regions, purposes and subjects - beyond South Asia, to policy design and to matters of routine hunger, environment, gender and overall intra-societal distributions. For analysis of famines, the approach provides a valuable set of concepts and questions in expanation and policy design; but it gives a general frame rather than a comprehensive theory or detailed explanatory model. For wider subjets, this general approach - a socially disaggregated, institutionally aware analysis of effective command over specific necessities - is again valuable. However, difficulties may arise with its concept of entitlement relations', and with confusions related to the label and the referent of the 'entitlement' concept and to the original 'exchange entitlement' label. Sen's concepts and labels reflected, naturally enough, the purposes in his study of the 1940's Bengal famine and its specific conditions. A modified set of concepts and labels may be more helpful, together with an underlining of the variety of contexts and of the limits to any one theoretical frame.
Round Robin Analysis of Variance via Maximum Likelihood

Abstract A class of two-way random-effects models is presented for analyzing data that arise in a large variety of round robin designs. Examples of such designs can be found in numerous games, tournaments, and social interactions. The proposed models provide information not only about individual differences but also about the mutual contingency of the behaviors of interaction dyads. The statistical inference of the linear effects is discussed and a converging algorithm based on the EM algorithm is proposed for obtaining the maximum likelihood estimates of the covariance components. A balanced data set is analyzed using the methodology developed.
A MODEL FOR THE CHROMOSPHERE/WIND OF 31 CYGNI AND ITS IMPLICATIONS FOR SINGLE STARS

I develop a detailed empirical model for the chromosphere and wind of 31 Cyg based on a previously published analysis of International Ultraviolet Explorer spectra from the 1993 eclipse and on the thermodynamics of how the wind must be driven. I then use this model to interpret observations of single supergiant stars and to assess the evidence that their winds are fundamentally different from those of supergiants in binary systems. This model naturally predicts a certain level of clumping of the gas to balance the pressure that drives the wind. It also predicts that anisotropic turbulence, such as would result from transverse displacements of Alfven waves directed along radial magnetic flux lines, would not give the roughly Gaussian profiles of emission lines seen in cool giant stars. Furthermore, it implies that C II] may not tell us much at all about general conditions in chromospheres. Finally, I speculate that chaotic magnetic fields, in dynamical equilibrium with the gas of the wind, are the actual driving mechanism.
Distributed algorithms for multicommodity flow problems via approximate steepest descent framework

We consider solutions for distributed multicommodity flow problems, which are solved by multiple agents operating in a cooperative but uncoordinated manner. We show first distributed solutions that allow (1 + e) approximation and whose convergence time is essentially linear in the maximal path length, and is independent of the number of commodities and the size of the graph. Our algorithms use a very natural approximate steepest descent framework, combined with a blocking flow technique to speed up the convergence in distributed and parallel environment. Previously known solutions that achieved comparable convergence time and approximation ratio required exponential computational and space overhead per agent.
Role of epidermal primary cilia in the homeostasis of skin and hair follicles

Skin and hair follicle morphogenesis and homeostasis require the integration of multiple signaling pathways, including Hedgehog (Hh) and Wingless (Wnt), and oriented cell divisions, all of which have been associated with primary cilia. Although studies have shown that disrupting dermal cilia causes follicular arrest and attenuated Hh signaling, little is known about the role of epidermal cilia. Here, epidermal cilia function was analyzed using conditional alleles of the ciliogenic genes Ift88 and Kif3a . At birth, epidermal cilia mutants appeared normal, but developed basaloid hyperplasia and ingrowths into the dermis of the ventrum with age. In addition, follicles in the tail were disorganized and had excess sebaceous gland lobules. Epidermal cilia mutants displayed fewer long-term label-retaining cells, suggesting altered stem cell homeostasis. Abnormal proliferation and differentiation were evident from lineage-tracing studies and showed an expansion of follicular cells into the interfollicular epidermis, as is seen during wound repair. These phenotypes were not associated with changes in canonical Wnt activity or oriented cell division. However, nuclear accumulation of the ΔNp63 transcription factor, which is involved in stratification, keratinocyte differentiation and wound repair, was increased, whereas the Hh pathway was repressed. Intriguingly, the phenotypes were not typical of those associated with loss of Hh signaling but exhibited similarities with those of mice in which ΔNp63 is overexpressed in the epidermis. Collectively, these data indicate that epidermal primary cilia may function in stress responses and epidermal homeostasis involving pathways other than those typically associated with primary cilia.
On Intersections of Cantor Sets: Hausdorff Measure

We establish formulas for bounds on the Haudorff measure of the intersection of certain Cantor sets with their translates. As a consequence we obtain a formula for the Hausdorff dimensions of these intersections.
TECHNICAL ANALYSIS IN COMMODITY MARKETS: RISK, RETURNS, AND VALUE

Although there is little academic research that supports the usefulness of technical analysis, its use remains widespread in commodity markets. Much prior research into technical analysis suffered from data-snooping biases. Using genetic programming, ex ante optimal technical trading strategies are identified. Because they are mechanically generated from simple arithmetic operators, they are free of the data-snooping bias common in technical analysis research. These rules are clearly capable of forecasting periods of high and low volatility, but rules generated for corn and soybeans cannot consistently generate profits in the presence of transactions costs. Rules generated for wheat futures produce profits that are weakly significant, both statistically and economically.
SEXUAL MORALITY AND THE DILEMMA OF THE COLLEGES.

Three sexual moralities are being intensely debated in colleges—the “new morality,” amorality, and traditional morality. College administrators have no consistent mandate for policy from faculty, students, parents or alumni. Their dilemma and possible ways of solving it are here presented. Understanding of issues rather than proliferation of rules is stressed.
Optimal auditing and insurance in a dynamic model of tax compliance

We study the optimal auditing of a taxpayer’s income in a dynamic principalagent model of hidden income. Taxpayers in our model initially have low income and stochastically transit to high income that is an absorbing state. A low-income taxpayer who transits to high income can underreport his true income and evade his taxes. With a constant absolute risk-aversion utility function and a costly and imperfect auditing technology, we show that the optimal auditing mechanism in our model consists of cycles. Within each cycle, a low-income taxpayer is initially unaudited, but if the duration of low-income reports exceeds a threshold, then the auditing probability becomes positive. That is, the tax authority guarantees that the taxpayer will not be audited until the threshold duration is reached. We also find that auditing becomes less frequent if the auditing cost is higher or if the variance of income is lower.
Central bank communication and expectations stabilization

The value of communication in monetary policy is analyzed in a model in which expectations need not be consistent with central bank policy –and, therefore, “unanchored” –because agents face di¢ cult forecasting problems. When the central bank implements optimal policy without communication, the Taylor principle is not su¢ cient for macroeconomic stability: expectations are unanchored and self-ful…lling expectations are possible. To mitigate this instability, three communication strategies are contemplated to ensure consistency between private forecasts and monetary policy strategy: i) communicating the precise details of the monetary policy — that is, the variables and coe¢ cients; ii) communicating only the variables on which monetary policy decisions are conditioned; and iii) communicating the in‡ation target. The …rst two strategies restore the Taylor principle as a su¢ cient condition for anchoring expectations. In contrast, in economies with persistent shocks, communicating the in‡ation target fails to protect against expectations driven ‡uctuations. These results underscore the importance of communicating the systematic component of monetary policy strategy: announcing an in‡ation target is not enough to stabilize expectations — one must also announce how this target will be achieved.
A thermodynamic model for the system SiO2–H2O near the upper critical end point based on quartz solubility experiments at 500–1100 °C and 5–20 kbar

Abstract A thermodynamic model of SiO 2 – H 2 O mixing in sub- and supercritical fluids has been developed based on new and existing experimental data on the solubility of quartz in H 2 O . To supplement previously published data, we conducted new solubility experiments at 15 and 20 kbar and 900–1100 °C using hydrothermal piston–cylinder methods. At concentrations below ∼ 10 mol% SiO 2 , solubility was measured by single-crystal weight loss. At higher concentrations, solubility was determined by bracketing the presence and absence of quartz in quenched charges using multiple isothermal and isobaric runs with varying SiO 2 – H 2 O ratios. These data were combined with previously published results to construct a thermodynamic model of SiO 2 – H 2 O mixing. Following studies of silicate melts, the model takes oxygen in the fluid to be in three forms: free, molecular H 2 O , Si-bridging oxygens ( O br 2 - ) , and the terminal hydroxyls ( OH tm - ) of silanol groups. The equilibrium exchange of oxygen between these forms can be written 1 2 H 2 O + 1 2 O br 2 - = OH tm - . The standard Gibbs free energy change of this reaction ( Δ G ∘ ) was incorporated into a subregular solution model for mixing of SiO 2 liquid and H 2 O fluid. The P–T dependences of Δ G ∘ and interchange energies were derived by an error minimization algorithm, producing thirteen independent fit parameters. The model is applicable from 5 to 20 kbar and 500 °C to the dry melting curve of quartz. It reproduces experimentally derived quartz solubility data to 3.8% on average (1 σ = 5.3%). The model also predicts hydrous melting of quartz, critical melt–vapor mixing, activity–concentration relations, partial molar volume and entropy of aqueous silica, water speciation, and the thermal expansivity, isothermal compressibility, and isobaric heat capacity of a fluid in equilibrium with quartz. The model predicts a critical end point in the SiO 2 – H 2 O system at 1067 °C and 9.33 kbar, in very good agreement with the accepted location at ∼ 1080 °C and 9.5–10 kbar. The model is also in good agreement with previous estimates of the extent of silica polymerization. The results of this study clearly demonstrate that there is an explicit link between polymerization chemistry and critical mixing of silicate– H 2 O solutions.
Simulations of relativistic collisionless shocks: shock structure and particle acceleration

We discuss 3D simulations of relativistic collisionless shocks in electron-positron pair plasmas using the particle-in-cell (PIC) method. The shock structure is mainly controlled by the shock's magnetization (''sigma'' parameter). We demonstrate how the structure of the shock varies as a function of sigma for perpendicular shocks. At low magnetizations the shock is mediated mainly by the Weibel instability which generates transient magnetic fields that can exceed the initial field. At larger magnetizations the shock is dominated by magnetic reflections. We demonstrate where the transition occurs and argue that it is impossible to have very low magnetization collisionless shocks in nature (in more than one spatial dimension). We further discuss the acceleration properties of these shocks, and show that higher magnetization perpendicular shocks do not efficiently accelerate nonthermal particles in 3D. Among other astrophysical applications, this may pose a restriction on the structure and composition of gamma-ray bursts and pulsar wind outflows.
Who Should Be Responsible for Software Security? A Comparative Analysis of Liability Policies in Network Environments

In recent years, vendor liability for software security vulnerabilities has been the center of an important debate in the software community and a topic gaining government attention in legislative committees and hearings. The importance of this question surrounding vendor security liability is amplified when one considers the increasing emergence of zero-day attacks where hackers take advantage of vulnerabilities before the software vendor has a chance to release protective patches. In this paper, we compare the effectiveness of three software liability policies: vendor liability for damages, vendor liability for patching costs, and government imposed security standards. We find that vendor liability for losses is not effective in improving social welfare in the short run, while liability for patching costs can be effective if either patching costs are large and the likelihood of a zero-day attack is low, or patching costs are small and zero-day likelihood is high. In the long run, when the vendor can invest in reducing the likelihood of security vulnerabilities, loss liability is still ineffective when the zero-day attack probability is high but can increase both vendor investment in security and social welfare when zero-day attack likelihood is sufficiently low. When the zero-day attack probability is high, patch liability is ineffective if user patching costs are large, but partial patch liability can boost vendor investment and improve welfare when patching costs are small. In contrast, in an environment with low zero-day attack probability, full vendor patch liability can be optimal. Finally, comparing the effectiveness of the three liability policies under study, we find that government imposed standards on software security investment can be preferable to both patching and loss liability on the vendor, if zero-day attack likelihood is sufficiently low. However, if zero-day attacks are a common occurrence and patching costs are not too high, partial patch liability is the most effective policy. This paper was accepted by Sandra Slaughter, information systems.
A model of inflation in Taiwan

The model of Chow (1987) for inflation in China is applied to explain inflation in Taiwan. A cointegration relation linear in the log of a price index and the log of the ratio of money supply to output is estimated. Inflation is explained by the change in this log ratio, lagged inflation and the lagged residual of the cointegration relation as an error correction. The model explains Taiwan?s inflation well except during the oil crises of 1973 and 1979-80.
A New Multidimensional Scaling Methodology for the Analysis of Asymmetric Proximity Data in Marketing Research

This paper presents a new multidimensional scaling MDS methodology which operationalizes the Krumhansl 1978 distance-density model for the analysis of asymmetric proximity data. In Krumhansl's conceptualization, the symmetric Euclidean interbrand distances typically associated with the traditional MDS model are augmented by the spatial density around the brands in the derived space. This modification allows the distance-density model to accommodate many of the empirically observed violations of the metric axioms such as asymmetry. An operationalization of the distance-density model is particularly attractive to marketers who often work with asymmetric brand switching data to investigate market structure and competition. We describe this new MDS procedure which is sufficiently flexible to fit a number of competing hypotheses of proximity. The algorithm employed for estimation is technically presented together with various program options. An analysis of an asymmetric brand switching matrix for automobiles is presented to illustrate the methodology. The results of this analysis are also compared with the solutions obtained from several of the currently available procedures for handling asymmetric proximity data. Finally, technical extensions to three-way analyses, hybrid models, etc., are discussed.
DECIPHERING THE SEESAW NATURE OF NEUTRINO MASS FROM UNITARITY VIOLATION

If neutrino masses are obtained via the canonical seesaw mechanism, based on an underlying 2 ×2 mass matrix, unitarity violation of the neutrino mixing matrix is unavoidable, but its effect is extremely small. On the other hand, in the inverse (and linear) seesaw mechanisms, based on an underlying 3 ×3 mass matrix, it can be significant and possibly observable. This 3 ×3 matrix is examined in more detail, and a new variation (the lopsided seesaw) is proposed which has features of both mechanisms. A concrete example based on U(1)N is discussed.
Restricted isometry of fourier matrices and list decodability of random linear codes

@q, with probability arbitrarily close to 1, is list decodable at radius 1--1/q -- e with list size L = O(1/e2) and rate R = Ωq(e2/(log3(1/e))). Up to the polylogarithmic factor in 1/e and constant factors depending on q, this matches the lower bound L = Ωq(1/e2) for the list size and upper bound R = Oq(e2) for the rate. Previously only existence (and not abundance) of such codes was known for the special case q = 2 (Guruswami, Hastad, Sudan and Zuckerman, 2002).In order to obtain our result, we employ a relaxed version of the well known Johnson bound on list decoding that translates the average Hamming distance between codewords to list decoding guarantees. We furthermore prove that the desired average-distance guarantees hold for a code provided that a natural complex matrix encoding the codewords satisfies the Restricted Isometry Property with respect to the Euclidean norm (RIP-2). For the case of random binary linear codes, this matrix coincides with a random submatrix of the Hadamard-Walsh transform matrix that is well studied in the compressed sensing literature.Finally we improve the analysis of Rudelson and Vershynin (2008) on the number of random frequency samples required for exact reconstruction of k-sparse signals of length N. Specifically we improve the number of samples from O(k log (N) log2 (k)(log k+log log N)) to O(k log(N) log3(k)). The proof involves bounding the expected supremum of a related Gaussian process by using an improved analysis of the metric defined by the process. This improvement is crucial for our application in list decoding.
RXTE observations of 4U 1630-47 during the peak of its 1998 outburst

We present an analysis of the RXTE observations of 4U 1630−47 during its 1998 outburst. The light curve and the spectral evolution of the outburst were significantly different from the outbursts of the same source in 1996 and 1999. Special emphasis was placed on observations taken during the initial rise and during the maximum of the outburst. The maximum of the outburst was divided into three plateaux, with almost constant flux within each plateau, and fast jumps between them. The spectral and timing parameters are stable for each individual plateau, but significantly different between the plateaux. The variability detected on the first plateau is of special interest. During these observations the source exhibits quasi-regular oscillations with a period of ∼10–20 s. Our analysis revealed a difference in temporal behaviour of the source at high and low fluxes during this period of time. The source behaviour can be generally explained in the framework of the two-phase model of accretion flow, involving a hot inner Comptonization region and surrounding optically thick disc. The variability and spectral evolution of the source were similar to what was observed earlier for other X-ray novae. We show that 4U 1630−47 resembles, in several aspects, other transient and persistent black hole binaries.
Validation and Operation of a Wake Vortex/Shear Interaction Model

A vortex method model developed previously for studying the mechanisms in vortex/shear-layer interactions has been validated with large-eddy turbulence simulations by Proctor et al. (Proctor, F. H., Hinton, D. A., Han, J., Schowalter, D. G., and Lin, Y. L.) and field measurement data. A shear-detection algorithm used to incorporate meteorological wind data is developed. Operational issues are also explored. The shear-thickness effects and the wind measurement resolution requirement and its sensitivity to the prediction algorithm are discussed. The objective of this work is to develop a computational method that is both accurate enough for the intended purpose and rapid enough to be of use in an operational setting at airports
On Multiterminal Source Code Design

Multiterminal (MT) source coding refers to separate lossy encoding and joint decoding of multiple correlated sources. Recently, the rate region of both direct and indirect MT source coding in the quadratic Gaussian setup with two encoders was determined. We are thus motivated to design practical MT source codes that can potentially achieve the entire rate region. In this paper, we present two practical MT coding schemes under the framework of Slepian-Wolf coded quantization (SWCQ) for both direct and indirect MT problems. The first, asymmetric SWCQ scheme relies on quantization and Wyner-Ziv coding, and it is implemented via source splitting to achieve any point on the sum-rate bound. In the second, conceptually simpler scheme, symmetric SWCQ, the two quantized sources are compressed using symmetric Slepian-Wolf coding via a channel code partitioning technique that is capable of achieving any point on the Slepian-Wolf sum-rate bound. Our practical designs employ trellis-coded quantization and turbo/low-density parity-check (LDPC) codes for both asymmetric and symmetric Slepian-Wolf coding. Simulation results show a gap of only 0.139-0.194 bit per sample away from the sum-rate bound for both direct and indirect MT coding problems.
1-Bromo-1-lithioethene: A Practical Reagent in Organic Synthesis

A reliable preparative scale synthesis of 1-bromo-1-lithioethene is reported. This reagent undergoes clean 1,2-addition with a range of aldehydes and ketones at −110 °C to afford the corresponding 2-bromo-1-alken-3-ols in moderate to excellent yield. Trapping with other electrophiles (acylsilanes, chlorosilanes, tributyltin chloride, iodine) cleanly provides practically useful yields of various 1-substituted 1-bromoethene products. Unexpectedly high diastereoselectivities were observed during the addition of 1-bromo-1-lithioethene to α-siloxy aldehydes (typically 10:1, Felkin−Ahn control) and protected ketopyranose and ketofuranose sugars (≥10:1, addition from the less-hindered face). The title organolithium reagent possesses relatively low basicity at low temperature, and is compatible with a variety of common protecting groups. We believe that these unusual properties of 1-bromo-1-lithioethene may originate from the specific crystalline structure of the reagent in which lithium is coordinatively saturat...
Interference Mitigation Through Limited Transmitter Cooperation

Interference limits performance in wireless networks and cooperation among receivers or transmitters can help mitigate interference by forming distributed MIMO systems. Earlier work shows how limited receiver cooperation helps mitigate interference. The scenario with transmitter cooperation, however, is more difficult to tackle. In this paper we study the two-user Gaussian interference channel with conferencing transmitters to make progress towards this direction. We characterize the capacity region to within 6.5 bits/s/Hz, regardless of channel parameters. Based on the bounded-gap-to-optimality result, we show that there is an interesting reciprocity between the scenario with conferencing transmitters and the scenario with conferencing receivers and their capacity regions are within a bounded gap to each other. Hence, in the interference-limited regime, the behavior of the benefit brought by transmitter cooperation is the same as that by receiver cooperation.
Pragmatic aspects of reusable program generators

When writing a program generator requires considerable intellectual effort, it is valuable to amortize that effort by using the generator to build more than one application. When a program generator serves multiple clients, however, the implementor must address pragmatic questions that implementors of single-use program generators can ignore. In how many languages should generated code be written? How should code be packaged? What should the interfaces to the client code look like? How should a user control variations? This paper elaborates on these questions by means of case studies of the New Jersey Machine-Code Toolkit, the $\lambda$-RTL Translator, and the ASDL program generator. It is hoped that the paper will stimulate the development of better techniques. Most urgently needed are a standard way to support multiple target languages and a simple, clear way to control interfaces to generated code.
Worst-Case and Average-Case Analysis of n-Detection Test Sets

Test sets that detect each target fault n times (n-detection test sets) are typically generated for restricted values of n due to the increase in test set size with n. We perform both a worst-case analysis and an average-case analysis to check the effect of restricting n on the unmodeled fault coverage of an (arbitrary) n-detection test set. Our analysis is independent of any particular test set or test generation approach. It is based on a specific set of target faults and a specific set of untargeted faults. It shows that, depending on the circuit, very large values of n may be needed to guarantee the detection of all the untargeted faults. We discuss the implications of these results.
Gross and Histologic Lesions of Adenovirus Group I in Guinea Fowl

Avian species show distinct differences in pathologic presentations due to avian adenovirus infections. The role of adenoviruses as pathogens is well documented in certain diseases but not as well documented in other clinical conditions. Quail bronchitis and inclusion body hepatitis due to group I adenovirus affect primarily the trachea and liver, respectively . 5,9 Group II adenovirus in marble spleen disease (MSD) of pheasants and hemorrhagic enteritis of turkeys affects primarily the respiratory and digestive systems, respectively. 2,5
Unparticle self-interactions

We develop techniques for studying the effects of self-interactions in the conformal sector of an unparticle model. Their physics is encoded in the higher n-point functions of the conformal theory. We study inclusive processes and argue that the inclusive production of unparticle stuff in standard model processes due to the unparticle self-interactions can be decomposed using the conformal partial wave expansion and its generalizations into a sum over contributions from the production of various kinds of unparticle stuff, corresponding to different primary conformal operators. Such processes typically involve the production of unparticle stuff associated with operators other than those to which the standard model couples directly. Thus just as interactions between particles allow scattering processes to produce new particles in the final state, so unparticle self-interactions cause the production of various kinds of unparticle stuff. We discuss both inclusive and exclusive methods for computing these processes. The resulting picture, we believe, is a step towards understanding what unparticle stuff “looks like” because it is quite analogous to way we describe the production and scattering of ordinary particles in quantum field theory, with the primary conformal operators playing the role of particles and the coefficients in the conformal partial wave expansion (and its generalization to include more fields) playing the role of amplitudes. We exemplify our methods in the 2D toy model that we discussed previously in which the Banks-Zaks theory is exactly solvable.