cssi/SciSciGPT-SciSciNet huggingface dataset:
Tectonic development of the Samail ophiolite: High‐precision U‐Pb zircon geochronology and Sm‐Nd isotopic constraints on crustal growth and emplacement

[1] New high-precision single grain U-Pb zircon geochronology and whole rock Nd isotopic data provide insight into the magmatic and tectonic development of the Samail ophiolite. The analyzed rocks can be broadly divided into two groups based on their structural position, dates, and isotopic composition: an older group related to on-axis magmatism and a younger group of post-ridge dikes, sills, and stocks. On-axis gabbros, tonalites and trondhjemites yielded Th-corrected 206Pb/238U dates from 96.441 ± 0.062 to 95.478 ± 0.056 Ma. These dates, combined with dates from Rioux et al. (2012), suggest that most of the ophiolite crust formed at an oceanic spreading center in <1 Ma. The post-ridge intrusions come from all depths in the crust, the upper mantle, and the metamorphic sole. Post-ridge gabbros, tonalites, and trondhjemites from the crust and mantle yielded Th-corrected 206Pb/238U dates of 95.405 ± 0.062 to 95.077 ± 0.062 Ma. A small trondhjemitic pod from the metamorphic sole yielded younger Th-corrected 206Pb/238U dates of 94.90 ± 0.38 to 94.69 ± 0.12 Ma. Isotopic data suggest two distinct sources for the post-ridge magmas: five of the gabbros and tonalites from the crust have eNd(96 Ma) = 6.90 ± 0.12 to 7.88 ± 0.16, and two trondhjemites from the upper mantle and metamorphic sole have eNd(96 Ma) = −7.77 ± 0.08 and −7.01 ± 0.16. The negative eNd(t) and U-Pb dates from the mantle dike require that subduction or thrusting was established below the ophiolite ≤0.25–0.5 Ma after formation of the crust. The bimodal isotopic composition of post-ridge magmas may reflect coeval decompression and/or fluid fluxed melting of the mantle and melting, dehydration, or assimilation of sediment in the down going plate at this time. The new data place temporal constraints on mid-ocean ridge and supra-subduction zone models for ophiolite formation.
Energy subsidies reform in Jordan : welfare implications of different scenarios

Facing a fiscal crisis, Jordan initiated substantial petroleum subsidy reforms in 2012. The government has also long contemplated how to cut electricity subsidies, which surpass the fiscal burdens imposed by the petroleum subsidies. This paper estimates the impacts of the 2012 petroleum subsidies reform on household welfare and government revenues. It also simulates the distributional and fiscal impacts from ending subsidies in the electricity sector, where the pricing structure is more complex than petroleum prices. The paper looks at the direct and indirect impacts of reform. Moreover, the paper discusses the political economy considerations of reform. While the full removal of petroleum subsidies would have increased poverty, the compensatory cash transfer program the government instituted is estimated to have fully offset the negative impact for the poorer population. The impact of reforms in the electricity sector will depend significantly on the implementation method chosen. A flat increase of tariffs toward cost recovery will put a huge burden on the poorest households. However, a progressive increase in tariffs will generate substantial savings for the government, even with compensatory mechanisms to mitigate the strong negative impact on the vulnerable population. The immediate compensation of the losers from reform appears to be a crucial factor in the successful implementation of reforms in Jordan.
Using "Cheat Sheets" to Distinguish Ability from Knowledge: Evidence from a Randomized Control Trial in Chile

According to the existing evidence some higher education admission tests may be screening out students who, despite a relative lack of specific knowledge, possess as much intellectual ability as their peers. If this is the case, students from disadvantaged socioeconomic backgrounds are likely to be disproportionately affected, since they generally receive a primary and secondary education of worse quality than their better-off peers, often resulting in significant knowledge gaps. Also, although in some cases these formative shortcomings might be too large to be feasibly addressed at the time of enrollment in higher education, it is plausible to think that in some cases they may perhaps be relatively easy to remedy. In view of all this, in this paper I present a diagnostics experiment, aimed at helping to better understand this issue. In particular, I custom-designed a multiple-choice test, intended to measure an individual's mathematical ability, while minimizing the reliance on previously acquired knowledge. Also, I put together a two page "cheat sheet", which outlined all the necessary concepts to successfully complete the exam, without providing any explicit answers. This test was subsequently used to evaluate the candidates applying for admission into a special access program at one of the leading Chilean universities. A staged randomized control trial was used to measure the difference in academic performance (i.e. number of correctly answered questions) across the three parts of the exam between students who received a "cheat sheet" after the first or second parts of the test, respectively. As expected, "cheat sheets" improved the average performance of candidates on the exam, but their impact varied considerably across individuals. Most importantly, "cheat sheets" proved significantly more beneficial (in terms of improved test performance) to those students who were more likely to have had a secondary education of lower quality. This result has important implications for educational policies in Chile and elsewhere, suggesting that a transition to ability-focused admission tests would facilitate the access to higher education for talented students from disadvantaged backgrounds.
Depth Fields: Extending Light Field Techniques to Time-of-Flight Imaging

A variety of techniques such as light field, structured illumination, and time-of-flight (TOF) are commonly used for depth acquisition in consumer imaging, robotics and many other applications. Unfortunately, each technique suffers from its individual limitations preventing robust depth sensing. In this paper, we explore the strengths and weaknesses of combining light field and time-of-flight imaging, particularly the feasibility of an on-chip implementation as a single hybrid depth sensor. We refer to this combination as depth field imaging. Depth fields combine light field advantages such as synthetic aperture refocusing with TOF imaging advantages such as high depth resolution and coded signal processing to resolve multipath interference. We show applications including synthesizing virtual apertures for TOF imaging, improved depth mapping through partial and scattering occluders, and single frequency TOF phase unwrapping. Utilizing space, angle, and temporal coding, depth fields can improve depth sensing in the wild and generate new insights into the dimensions of light's plenoptic function.
Steep-Spectrum Radio Emission from the Low-Mass Active Galactic Nucleus GH 10

GH 10 is a broad-lined active galactic nucleus (AGN) energized by a black hole of mass 800,000 M☉. It was the only object detected by Greene et al. in their Very Large Array (VLA) survey of 19 low-mass AGNs discovered by Greene & Ho. New VLA imaging at 1.4, 4.9, and 8.5 GHz reveals that GH 10's emission has an extent of less than 320 pc, has an optically thin synchrotron spectrum with a spectral index α = − 0.76 ± 0.05 (Sν ∝ ν+ α), is less than 11% linearly polarized, and is steady—although poorly sampled—on timescales of weeks and years. Circumnuclear star formation cannot dominate the radio emission, because the high inferred star formation rate, 18 M☉ yr−1, is inconsistent with the rate of less than 2 M☉ yr−1 derived from narrow Hα and [O II] λ3727 emission. Instead, the radio emission must be mainly energized by the low-mass black hole. GH 10's radio properties match those of the steep-spectrum cores of Palomar Seyfert galaxies, suggesting that, like those galaxies, the emission is outflow-driven. Because GH 10 is radiating close to its Eddington limit, it may be a local analog of the starting conditions, or seeds, for supermassive black holes. Future imaging of GH 10 at higher linear resolution thus offers an opportunity to study the relative roles of radiative versus kinetic feedback during black hole growth.
Heterojunctions: Definite breakdown of the electron affinity rule

We performed a simple and straightforward synchrotron-radiation photoemission test of the electron affinity rule, the oldest and most widely used model to predict semiconductor-semiconductor band lineups. The results show, beyond any experimental uncertainty, that the rule is incorrect. The elimination of the rule and of all models related to it considerably simplifies the theoretical situation of this fundamental area of solid-state physics.
Accurate multigrid solution of the Euler equations on unstructured and adaptive meshes

A method for accurately solving inviscid compressible flow in the subcritical and supercritical regimes about complex configurations is presented. The method is based on the use of unstructured triangular meshes in two dimensions, and special emphasis is placed on the accuracy and efficiency of the solutions. High accuracy is achieved by careful scaling of the artificial dissipation terms, and by reformulating the inner and outer boundary conditions for both the convective and dissipative operators. An adaptive grid refinement strategy is presented which enhances the solution accuracy for complex flows. When coupled with an unstructured multigrid algorithm, this method is shown to produce an efficient solver for flows about arbitrary configurations.
CROWELL'S DERIVED GROUP AND TWISTED POLYNOMIALS

The derived group of a permutation representation, introduced by Crowell, unites many notions of knot theory. We survey Crowell's construction, and offer new applications. The twisted Alexander group of a knot is defined. Using it, we obtain twisted Alexander polynomials. Also, we extend a well-known theorem of Neuwirth and Stallings giving necessary and sufficient conditions for a knot to be fibered. Virtual Alexander polynomials provide obstructions for a virtual knot that must vanish if the knot has a diagram with an Alexander numbering. The extended group of a virtual knot is defined, and using it a more sensitive obstruction is obtained.
ON surrogate loss functions and f-divergences

The goal of binary classification is to estimate a discriminant function y from observations of covariate vectors and corresponding binary labels. We consider an elaboration of this problem in which the covariates are not available directly but are transformed by a dimensionality-reducing quantizer Q. We present conditions on loss functions such that empirical risk minimization yields Bayes consistency when both the discriminant function and the quantizer are estimated. These conditions are stated in terms of a general correspondence between loss functions and a class of functionals known as Ali-Silvey or /-divergence functionals. Whereas this correspondence was established by Blackwell [Proc. 2nd Berkeley Symp. Probab. Statist. 1 (1951) 93-102. Univ. California Press, Berkeley] for the 0-1 loss, we extend the correspondence to the broader class of surrogate loss functions that play a key role in the general theory of Bayes consistency for binary classification. Our result makes it possible to pick out the (strict) subset of surrogate loss functions that yield Bayes consistency for joint estimation of the discriminant function and the quantizer.
The synthesis of substituted saccharins through the o-lithiative sulfonamidation of N,N-diethylbenzamides

Abstract The readily available N,N-diethylbenzamides 2 are converted in two reaction steps to a variety of substituted saccharins 4 in good overall yields.
CO‐Ligandenaustausch in Carbonylmetallverbindungen und seine Frequenz in Fe(CO)5

Temperaturabhangige NMR-Experimente haben vielfach qualitativ erwiesen, das den meisten Carbonylmetallverbindungen keine starre Struktur zukommt. Die quantitative Bestimmung der Ligandenaustauschfrequenz ve ist oft durch Linienformanalyse des NMR-Absorptionsspektrums oder durch Messung der transversalen Relaxationszeit T2 nach der Carr-Purcell-Methode moglich. Im Falle eines sehr schnellen Austausches versagen jedoch beide Methoden. In diesem Beitrag wird gezeigt, das durch simultane Anpassung der IR- oder Raman-Spektren einerseits und der NMR-Spektren andererseits die Bestimmung von ve auch fur „sehr schnellen” Austausch gelingt und in Fallen eines „langsamen” sowie „schnellen” Austausches betrachtlich erleichtert wird. Die so fur flussiges Fe(CO)5 gefundene Ligandenaustauschfrequenz 1.1 · 1010 S−1 ist unerwartet hoch; ein Vergleich mit temperaturabhangigen Messungen an festem Fe(CO)5 ergibt ahnliche Energieschwellen. Es wird ein Austauschmechanismus vorgeschlagen, der dem Berry-Mechanismus eng verwandt ist. Schlieslich werden die Konsequenzen dieser uberraschend hohen Ligandenaustauschfrequenz im Hinblick auf die Zuordnung von IR-Banden fur molekulare „Fragmente” M(CO)x (M Ubergangsmetall, typisches Lanthanoid oder Actinoid; x Koordinationszahl) erortert.
The effect of certain modular design principles on testability

This paper is a nonprogrammers view of design principles which are considered essential to testability of complex structures. The principles are related to the programming problem.The basic problems in verifying the function of any complex structure derive from: inadequate specification of function, the very large number of possible structures (most of which are “mistakes”) and the very large number of possible outputs for specified and unspecified inputs.Present trends in programming techniques are towards various forms of controlled modularity. If modularity is controlled so that the function of a module is independent of the source of its input, the destination of its output, and the past history of use of the module, the difficulty of testing the modules and structures assembled from the modules is greatly reduced. Multilevel modularity also powerfully reduces the complexity of modules and structures. Controlled modularity requires that the separation of certain variables be rigorously maintained. Controlled branching also reduces complexity and testing requirements. These are examined with mathematical examples and it is concluded that if the proper principles of controlled modularity are observed, it should be technically feasible to design software to achieve specified function and that under certain conditions it should be economically feasible to test software so designed to practical levels of accuracy and reliability.
Photon and gluon emission in relativistic plasmas

We recently derived, using diagrammatic methods, the leading-order hard photon emission rate in ultra-relativistic plasmas. This requires a correct treatment of multiple scattering effects which limit the coherence length of emitted radiation (the Landau-Pomeranchuk-Migdal effect). In this paper, we provide a more physical derivation of this result, and extend the treatment to the case of gluon radiation.
Apparent Mass of Parafoils with Spanwise Camber

For an arbitrarily shaped body, there may be more than one center of apparent mass. The apparent mass of a parafoil shape for motions along various axes is computed using potential flow analysis. From this, the 6 x 6 apparent mass matrix about some reference point is computed. Parametric forms for estimating the terms are given. The existence of multiple mass centers results in off-diagonal terms in this matrix that couple the translational and rotational motions. It is shown how the nondiagonal 6 x 6 apparent inertia matrix about a certain reference point can be used to compute the corresponding apparent mass matrix at any other reference point. Dynamic equations including nonlinear terms are presented.
What We Mean by Social Determinants of Health

This article analyzes the changes in health conditions and quality of life in the populations of developed and developing countries over the past 30 years, resulting from neoliberal policies developed by many governments and promoted by the World Bank, International Monetary Fund, World Health Organization, and other international agencies. It challenges interpretations by the analysts of “globalization,” including the common assumption that states are disappearing. The author shows that what has been happening is not a reduction of state interventions but a change in the nature and character of those interventions, resulting from major changes in class (and race and gender) power relations in each country, with establishment of an alliance between the dominant classes of developed and developing countries—a class alliance responsible for the promotion of its ideology, neoliberalism. This is the cause of the enormous health inequalities in the world today. The article concludes with a critical analysis of...
Evolution of Fairness in the Not Quite Ultimatum Game

The Ultimatum Game (UG) is an economic game where two players (proposer and responder) decide how to split a certain amount of money. While traditional economic theories based on rational decision making predict that the proposer should make a minimal offer and the responder should accept it, human subjects tend to behave more fairly in UG. Previous studies suggested that extra information such as reputation, empathy, or spatial structure is needed for fairness to evolve in UG. Here we show that fairness can evolve without additional information if players make decisions probabilistically and may continue interactions when the offer is rejected, which we call the Not Quite Ultimatum Game (NQUG). Evolutionary simulations of NQUG showed that the probabilistic decision making contributes to the increase of proposers' offer amounts to avoid rejection, while the repetition of the game works to responders' advantage because they can wait until a good offer comes. These simple extensions greatly promote evolution of fairness in both proposers' offers and responders' acceptance thresholds.
Cluster Algebras of Finite Type via Coxeter Elements and Principal Minors

We give a uniform geometric realization for the cluster algebra of an arbitrary finite type with principal coefficients at an arbitrary acyclic seed. This algebra is realized as the coordinate ring of a certain reduced double Bruhat cell in the simply connected semisimple algebraic group of the same Cartan–Killing type. In this realization, the cluster variables appear as certain (generalized) principal minors.
Obtaining low bottomhole pressures in deep wells with hydraulic jet pumps

Maximizing production in a well requires reducing the bottomhole pressure (BHP) to the lowest practical minimum by artificial lift. This task is particularly difficult in deep wells because of the need to transmit power a long distance to the bottom of the well and because of the high temperatures encountered at depth. Reciprocating hydraulic pumps have historically been used for this purpose in deep wells, especially those deeper than 10,000 ft (3048 m). for more than a decade, the hydraulic jet pump has successfully produced deep wells. In a number of cases, jet pumps have produced deep wells to less than 10% submergence. This paper identifies the hydraulic jet pump as a reasonable method to produce deep wells to low BHP's with predictable performance. A number of examples and well tests illustrate the performance of jet-pumped production systems.
Direct and Cross-Polarized Backscatter Radar Cross Sections of a Turbulent Plasma

E this paper, the backscattered RCS (radar cross sec3n) from a turbulent plasma is calculated. The computation is restricted to a single scattering in the plasma. However, no total internal reflection of the incident radiation gives rise to a depolarization of the backscattered return. The RCS is calculated as a function of the size and electron density of the plasma, the frequency, and the incident angle of the radiation.
Process logic: Expressiveness, decidability, completeness

Abstract A process logic (PL) is defined that subsumes Pratt's process logic, Parikh's SOAPL, Nishimura's process logic, and Pnueli's Temporal Logic in expressiveness. The language of PL is an extension of the language of Propositional Dynamic Logic (PDL). A deductive system for PL is given which includes the Segerberg axioms for PDL and it is proved that it is complete. It is also shown that PL is decidable.
Centrality dependence of azimuthal anisotropy of strange hadrons in 200 GeV Au + Au collisions

Measurements of azimuthal anisotropy for strange and multi-strange hadrons are presented for the first time in their centrality dependence. The high statistics results of ν 2 (p T ) allow for a more detailed comparison to hydrodynamical model calculations. Number-of-constituent-quark scaling was tested for different centrality classes separately. Higher order anisotropies like ν 4 (p T ) are measured for multi-strange hadrons. While we observe agreement between measured data and models, a deeper understanding and refinement of the models seem to be necessary in order to fully understand the details of the data.
A new min‐cut problem with application to electric power network partitioning

The problem of partitioning a graph into two or more subgraphs that satisfies certain conditions is encountered in many different domains. Accordingly, graph partitioning problem has been studied extensively in the last 50 years. The most celebrated result among this class of problems is the max flow = min cut theorem due to Ford and Fulkerson. Utilizing the modifications suggested by Edmonds and Karp, it is well known that the minimum capacity cut in the directed graph with edge weights can be computed in polynomial time. If the partition divides the node set V into subsets V1 and V2, where V1 contains one of the specified nodes s and V2 contains the other specified node t, the capacity of a cut is defined as the sum of the edge weights going from V1 to V2. In electrical power distribution networks, a slow-coherency-based islanding strategy is used as a prevention against the cascading failures. In this paper, we concentrate on the graph partition problems which are encountered in electric power distribution networks. In this environment, two different definitions of capacity of a cut are used. In the first definition, capacity of a cut is taken to be the difference of the edge weights going from V1 to V2 and from V2 to V1. In the second definition, the capacity of a cut is taken to be the maximum of sum of the edge weights going from V1 to V2 and from V2 to V1. Surprisingly, with slight change of the definition of the capacity of a cut, the computational complexity of the problem changes significantly. In this paper, we show that with the new definitions of the capacity of a cut, the minimum cut computation problem becomes NP-complete. We provide an optimal solution to the problems using mathematical programming techniques. In addition, we also provide heuristic solutions and compare the performance with that of the optimal solution. Copyright © 2008 John Wiley & Sons, Ltd.
ACCURATE SCALE DETERMINATIONS FOR THE WILSON GAUGE ACTION

Accurate determinations of the physical scale of a lattice action are required to check scaling and take the continuum limit. We present a high statistics study of the static potential for the SU(3) Wilson gauge action on coarse lattices (5.54 ⩽ β ⩽ 6.0). Using an improved analysis procedure we determine the string tension and the Sommer scale ro (and related quantities) to I% accuracy, including all systematic errors. Combining our results with earlier ones on finer lattices, we present parameterizations of these quantities that should be accurate to about 1 % for 5.6 ⩽ β S 6.5. We estimate the A-parameter of quenched QCD to be ΛGMs = 247(16) MeV.
Corneal nerve alterations in acute Acanthamoeba and fungal keratitis: an in vivo confocal microscopy study.

To study sub-basal corneal nerve alterations in patients with acute Acanthamoeba keratitis (AK) and fungal keratitis (FK), using laser in vivo confocal microscopy (IVCM). A retrospective analysis of IVCM (Heidelberg Retina Tomograph 3/Rostock Cornea Module) images of 10 AK corneas and 4 FK corneas was performed, and the results compared with those of 10 normal and 12 acute herpetic keratitis (HK) corneas. Sub-basal corneal nerves were analyzed with respect to total number of nerves, main nerve trunks, branching pattern and total length of nerves per image, as well as tortuosity. For each variable, results for three frames were averaged and analyzed using analysis of variance. Total corneal nerve length was significantly (P<0.0001) reduced in patients with AK (193.4±124.5 μm) and FK (268.6±257.4 μm) when compared with normal controls (3811.84±911.4 μm). Total nerve counts in patients with AK (3.9±1.2) and FK (3.6±3.2) were significantly (P<0.0001) decreased in comparison with normal controls (24.7±5.5). The number of main nerve trunks and nerve branching was found to be significantly lower in AK and FK corneas, when compared with controls. There was a statistically significant decrease in the above parameters when compared with HK controls. The sub-basal corneal nerve plexus is significantly diminished in eyes with AK and FK, as demonstrated by IVCM. These results are more profound than previously reported findings of a diminished nerve plexus in HK.
Microscale permeability predictions of porous fibrous media

A good understanding of woven fiber preform permeabilities is critical in the design and optimization of the composite molding processes encountered in resin transfer molding (RTM); yet these issues remain unresolved in the literature. Many have attempted to address permeability predictions for flat undeformed fiber preform, but few have investigated permeability variations for complex geometries of porous fibrous media. In this study, the objectives are to: (i) provide a brief review of existing methods for the prediction of the fiber mat permeability; (ii) postulate a more realistic representation of a unit cell to account for such fabric structures as crimp, tow spacing and the like; and (iii) apply computational approximations to predict effective permeabilities for use in modeling of structural composites manufacturing processes. The Stokes equation is used to model the flow in the inter-tow region of the unit cell, and in the intra-tow region, the Brinkman's equation is used. Initial permeability calculations are performed for a three-dimensional unit cell model representative of the PET-61 woven fabric composite. The results show good agreement with experimental data published in the literature.
Speculative histories of the Uranian satellite system

The hypothetical histories presently considered for the Uranian satellite system are very sensitive to the assumed satellite masses, within the errors of their determinations, as well as to the Uranian tidal effective dissipation function. A determination is made of the resonances that could have been encountered in these histories, and of the orbital eccentricity constraints that would have led to certain capture. It is found that if the mass of Miranda were of the upper extreme value, it would have been locked in a long-term 2/1 orbital resonance with Ariel to form a Laplacelike, three-body resonance that encompassed Umbriel.
266 E+A galaxies selected from the Sloan Digital Sky Survey Data Release 2: the origin of E+A galaxies

E+A galaxies are characterized as galaxies with strong Balmer absorption lines but without any [O ii] or Hα emission lines. The existence of strong Balmer absorption lines indicates that E+A galaxies have experienced starburst within the past one gigayear. However, the lack of [O ii] and Hα emission lines indicates that E+A galaxies do not have any on-going star formation. Therefore, E+A galaxies are interpreted as post-starburst galaxies. For many years, however, it has been a mystery why E+A galaxies started starburst and why they quenched star formation abruptly. Using one of the largest samples of 266 E+A galaxies carefully selected from the Sloan Digital Sky Survey Data Release 2, we have investigated the environment of E+A galaxies from 50 kpc to 8 Mpc scale, i.e. from a typical distance to satellite galaxies to the scale of large-scale structures. We found that E+A galaxies have an excess of local galaxy density only at a scale of <100 kpc (with a 2σ significance), but not at the cluster scale (∼1.5 Mpc) nor at the scale of large-scale structure (∼8 Mpc). These results indicate that E+A galaxies are not created by the physical mechanisms associated with galaxy clusters or the large-scale structure, but are likely to be created by dynamical interaction with closely accompanying galaxies at a <100 kpc scale. The claim is also supported by the morphology of E+A galaxies. We have found that almost all E+A galaxies have a bright compact core, and that ∼30 per cent of E+A galaxies have dynamically disturbed signatures or tidal tails, which quite strongly suggest the morphological appearance of merger/interaction remnants.
National, independent oversight: reinforcing the safety net for human subjects research.

National, independent oversight is vital to resolve the problems and inconsistencies in oversight of human subjects research. Three key functions that must be considered in any proposal for such a mechanism are (1) issue spotting, (2) guidance on identified issues, and (3) sampling and follow‐up. The 1998 report and recommendations of the National Bioethics Advisory Commission concerning research involving persons with mental disorders that may affect decisionmaking capacity address these functions in part, but application is limited to a small segment of the research population. Incorporation of these three key functions in a formal, national, independent oversight process is necessary in order to ensure accountability and maintain public trust in research.
Microphthalmia transcription factor: a sensitive and specific marker for malignant melanoma in cytologic specimens

BACKGROUND The diagnosis of melanoma can be difficult because of shared cytomorphology with other malignant neoplasms. The most commonly used melanocytic markers, anti-S-100 protein and HMB-45 antigen, have limited specificity and sensitivity, respectively. Microphthalmia transcription factor (Mitf) is a nuclear transcription factor critical for the development and survival of melanocytes and has been shown as a sensitive and specific marker for melanoma in histologic specimens. METHODS To evaluate the efficacy of Mitf as a marker for melanoma in cytologic preparations, 81 cell blocks from 44 patients with melanoma and 37 patients with nonmelanoma malignancies (29 patients with carcinoma, 4 patients with mesotheliomas, 2 patients with lymphoma, and 2 patients with islet cell tumors) were stained with monoclonal antibodies against Mitf (clone D5), S-100 protein, and HMB-45 antigen. The staining was evaluated blindly by three independent observers. The presence of nuclear staining for Mitf and cytoplasmic staining for S-100 protein or HMB-45 antigen in > 10% of tumor cells was considered positive staining for each antigen. RESULTS Forty-four melanomas (100%), including all 3 spindle-cell melanomas, were positive for Mitf. All nonmelanoma neoplasms were negative with only one exception: One mammary carcinoma showed rare (< 10%), weak nuclear staining with Mitf. The sensitivity and specificity of Mitf as a marker for melanoma were both 100%, whereas the sensitivity of HMB-45 antigen was 90.4%, and the specificity of S-100 protein was 70.3%. CONCLUSIONS Mitf is a sensitive and specific marker for malignant melanoma, including the spindle-cell variant, in cytologic specimens and may be superior to the current standard melanocytic markers, S-100 protein and HMB-45 antigen. Cancer (Cancer Cytopathol) 2001;93:337–343. © 2001 American Cancer Society.
Teaching problem solving and structured programming in FORTRAN

Abstract This paper describes an approach to teaching problem solving in an introductory programming course using the FORTRAN language. The course is oriented around a set of problems which are used to illustrate a problem solving methodology. Three pedagogic aids (data table, flow diagram, and program system chart) and two control structure extensions to the FORTRAN language are used in order to provide a more convenient framework in which students can practice good problem solving and programming techniques. The control structure extensions facilitate structured programming in FORTRAN. The use of the control structures and the pedagogic aids is illustrated in the solution of a simple statistics problem: the benefits derived from using these aids are also discussed.
A High Performance Spectral Code for Nonlinear MHD Stability

A new spectral code, NSTAB, has been developed to do nonlinear stability and equilibrium calculations for the magnetohydrodynamic (MHD) equations in three-dimensional toroidal geometries. The code has the resolution to test nonlinear stability by calculating bifurcated equilibria directly. These equilibria consist of weak solutions with current sheets near rational surfaces and other less localized modes. Bifurcated equilibria with a pronounced current sheet where the rotational transform crosses unity are calculated for the international thermonuclear experimental reactor (ITER). Bifurcated solutions with broader resonances are found for a model of the LHD stellarator currently being built in Japan and an optimized configuration like the Wendelstein VII-X proposed for construction in Germany. The code is able to handle the many harmonics required to capture the high mode number of these instabilities. NSTAB builds on the highly successful BETAS code, which applies the spectral method to a flux coordinate formulation of the variational principle associated with the MHD equilibrium equations. A new residue condition for the location of the magnetic axis has been developed and implemented. This condition is based on the weak formulation of the equations and imposes no constraints on the inner flux surfaces.
A continental‐scale analysis of tree cover in African savannas

Aim We present a continental-scale analysis that explores the processes controlling woody community structure in tropical savannas. We analyse how biotic and abiotic factors interact to promote and modify tree cover, examine alternative ecological hypotheses and quantify disturbance effects using satellite estimates of tree cover. Location African savannas. Methods Tree cover is represented as a resource-driven potential cover related to rainfall and soil characteristics perturbed by natural and human factors such as fire, cattle grazing, human population and cultivation. Within this framework our approach combines semi-empirical modelling and information theory to identify the best models. Results Woody community structure across African savannas is best represented by a sigmoidal response of tree cover to mean annual precipitation (MAP), with a dependency on soil texture, which is modified by the separate effects of fire, domestic livestock, human population density and cultivation intensity. This model explains c. 66% of the variance in tree cover and appears consistent across the savanna regions of Africa. Main conclusions The analysis provides a new understanding of the importance and interaction of environmental and disturbance factors that create the broad spatial patterns of tree cover observed in African savannas. Woody cover increases with rainfall, but is modified by disturbances. These ‘perturbation’ effects depend on MAP regimes: in arid savannas (MAP < 400 mm) they are generally small (< 1% decrease in cover), while in semi-arid and mesic savannas (400–1600 mm), perturbations result in an average 2% (400 mm) to 23% (1600 mm) decrease in cover; fire frequency and human population have more influence than cattle, and cultivation appears, on average, to lead to small increases in woody cover. Wet savannas (1600–2200 mm) are controlled by perturbations that inhibit canopy closure and reduce tree cover by, on average, 24–34%. Full understanding of the processes determining savanna structure requires consideration of resource limitation and disturbance dynamics.
Solidification of hazardous substances — A TGA and FTIR study of Portland cement containing metal nitrates

Abstract Type I Portland cement samples containing the soluble nitrates of the priority pollutant metals chromium, lead, barium, mercury, cadmium and zinc have been investigated by using thermogravimetric and fourier-transform infrared techniques (including diffuse reflectance). The major vibrational bands and thermal stability of the carbonate, sulfate, silicate, water and nitrate species are tabulated and discussed in comparison to uncontaminated Portland cement. The solubility and volatility of mercury in cement and the effect of metal nitrate concentration on the silicate condensation process is discussed. Although results suggest that retardation of cement setting by Zn and Pb salts occurs by limiting hydration, the chemistry of the two processes is distinctly different.
Device for measuring bronchodilator delivery and response in resource-limited settings

Effective delivery of aerosolized bronchodilators for patients with asthma is crucial for adequate therapy in critical care and emergent settings. Often administered with pressure-metered dose inhalers (pMDIs), bronchodilator delivery depends on the correct patient technique during administration [1] and the ability to measure treatment response, which are difficult to monitor at the point of care and particularly so in resource-poor settings where standard in-hospital monitoring is unavailable [2].
Biphasic amyloidosis: link between macular and lichenoid forms.

SUMMARY A woman manifested lichen amyloidosus of the right lower limb and macular amyloidosis of her left leg with congenitally impaired cutaneous sensation. Another patient had bilateral lichenoid amyloidosis of her legs. Unilateral triamcinolone injections produced the picture of macular amyloidosis in the treated leg. Light and electron microscopic studies of biopsies from both patients showed similar amyloid deposits in the papillae; the significant difference was epidermal hyperplasia in the lichenoid lesions. We suggest the term biophasic for the existence of both macular and lichenoid amyloidosis in the same patient.
Three Quantitative Management Problems in Public Procurement and Decision Procedures for their Analysis and Solving

Abstract Three management problems that a state (or a public administration acting on its behalf) faces in procuring goods and/or services are considered: a) choosing the type of a contract to be awarded and the type of a competitive bidding to determine the winning bid, b) setting the initial price for a contract being the subject of the bidding, and c) designing (or choosing) a set of rules for determining the winning bid by means of the chosen competitive bidding. Mathematical models and decision procedures for analyzing and solving these problems are discussed.
Galactic civilizations - Population dynamics and interstellar diffusion

The interstellar diffusion of galactic civilizations is reexamined by potential theory; both numerical and analytical solutions are derived for the nonlinear partial differential equations which specify a range of relevant models, drawn from blast wave physics, soil science, and, especially, population biology. An essential feature of these models is that, for all civilizations, population growth must be limited by the carrying capacity of the environment. Dispersal is fundamentally a diffusion process; a density-dependent diffusivity describes interstellar emigration. Two models are considered: the first describing zero population growth (ZPG), and the second which also includes local growth and saturation of a planetary population, and for which an asymptotic traveling wave solution is found.
Predicting quark and lepton masses and mixings

Abstract A model is presented that fits the quark and lepton masses and mixings wherein five dimensionless parameters and a phase account for fifteen dimensionless observables. Among these are the Wolfenstein parameters ρ and η , the ν e − ν μ and ν e − ν τ mixing angles which are predicted to be small and comparable while the ν μ − ν τ mixing angle is predicted to be large. The model is based on supersymmetric SO (10) with the form of the mass matrices motivated by simplicity at the level of grand unification.
Noncommutative Determinant is Hard: A Simple Proof Using an Extension of Barrington's Theorem

We show that, for many noncommutative algebras A, the hardness of computing the determinant of matrices over A follows almost immediately from Barrington's Theorem. Barrington showed how to express a NC^1 circuit as a product program over any non-solvable group. We construct a simple matrix directly from Barrington's product program whose determinant counts the number of solutions to the product program. This gives a simple proof that computing the determinant over algebras containing a non-solvable group is #P-hard or Mod_pP-hard, depending on the characteristic of the algebra. To show that computing the determinant is hard over noncommutative matrix algebras whose group of units is solvable, we construct new product programs (in the spirit of Barrington) that can evaluate 3SAT formulas even though the algebra's group of units is solvable. The hardness of noncommutative determinant is already known, it was recently proven by retooling Valiant's (rather complex) reduction of #3SAT to computing the permanent. Our emphasis here is on obtaining a conceptually simpler proof.
Catalytic enantioselective Diels-Alder reactions using titanium complexes of cis-N-sulfonyl-2-amino-1-indanols

Abstract A titanium complex derived from (1R, 2S)-N-(2,4,6-trimethylbenzenesulfonyl)-2-amino-1-indanol catalyzes the Diels-Alder reaction of 2-bromoacrolein and cyclopentadiene with 96.5:3.5 enantioselectivity. A new and efficient synthesis of 2-amino-1-indanol ( 6 ) contributes to the potential of this methodology.
Correlation between Emission, Electric, and Flow Properties of Arc Filament Plasma Actuators

Renewed interest in flow-control devices using various forms of plasmas has motivated the design and systematic investigation of localized arc-filament plasma actuators. This newly constructed system creates electric arcs by generating electric fields in the range of 20 kV/cm between two pin-type electrodes. The potential of the actuator to influence surrounding quiescent air when placed in a 5×2×1.6 mm cavity was investigated using emission imaging, particle image velocimetry, and current and voltage measurements. The emission imaging showed both temporal and spatial variation. The emission was most intense and variable in the first microsecond after breakdown. The particle-image-velocimetry data were acquired for several plasma currents, on times, and actuation frequencies. The data showed characteristic features of a hot gas expansion from a cavity, such as rapid gas dilatation exemplified through a blast wave, and cavity refilling from postdischarge cooling. The electric measurements were correlated...
The boundary sine-Gordon theory: Classical and semi-classical analysis

We consider the sine-Gordon model on a half-line, with an additional potential term of the form −M cos[12β(ϕ − ϕ0)] at the boundary. We compute the classical time delay for general values of M, β and ϕ0 using τ-function methods and show that in the classical limit the method of images still works, despite the non-linearity of the problem. We also perform a semi-classical analysis, and find agreement with the exact quantum S-matrix conjectured by Ghoshal and Zamolodchikov.
Free-Vibration Analysis of Rotating Beams by a Variable-Order Finite-Element Method

The free vibration of rotating beams is analyzed by means of a finite-element method of variable order. This method entails displacement functions that are a complete power series of a variable number of terms. The terms are arranged so that the generalized coordinates are composed of displacements and slopes at the element extremities and, additionally, displacements at certain points within the element. The displacement is assumed to be analytic within an element and thus can be approximated to any degree of accuracy desired by a complete power series. Numerical results are presented for uniform beams with zero and nonzero hub radii, tapered beams, and a nonuniform beam with discontinuities. Since the present method reduces to a conventional beam finite-element method for a cubic displacement function, the results are compared and found to be superior to the conventional results in terms of accuracy for a given number of degrees of freedom. Indeed, essentially exact eigenvalues and eigenvectors are obtained with this technique, which is far more rapidly convergent than other approaches in the literature.
The scattering mean free path in the Uranian atmosphere

New measurements of the equivalent widths of the 4.0 S(0) and S(1) H2 quadrupole lines in the Uranian spectrum have been obtained using high dispersion (4.12 A/mm) image-tube spectrography. The measured equivalent widths are 62 plus or minus 19 mA and 58 plus or minus 13 mA for the S(0) and S(1) lines, respectively. Curve-of-growth analysis in terms of a reflecting layer model yields an H2 column density of 780 (+940 or -330) km amagat and a temperature of 78 (+80 or -24) K. Interpretation using a semiinfinite, homogeneous, isotropically scattering model for line formation yields a scattering mean free path at 6400 A of 550 plus or minus 250 km amagat. Quoted errors for both the H2 column density and the scattering mean free path include the effect of uncertainty in the choice of atmospheric temperature. The results are discussed in terms of current models for the Uranian atmosphere.
Exact Inference for Contingency Tables with Ordered Categories

Abstract This article proposes an efficient numerical algorithm for small-sample exact inferences in contingency tables having ordinal classifications. The inferences, which apply conditional on the observed marginal totals, also provide an exact analysis for the log-linear model of linear-by-linear association for cell probabilities. An exact test of independence has a one-sided P value equal to the null probability that model-based maximum likelihood estimates of odds ratios are at least as large as the observed estimates. The conditional nonnull distribution yields confidence intervals for odds ratios having a linear-by-linear structure. The computations utilize an extension of the network algorithm proposed by Mehta and Patel (1983).
Biodendrimers: new polymeric biomaterials for tissue engineering.

Dendrimers composed entirely of building blocks known to be biocompatible or degradable in vivo to natural metabolites were synthesized using a high yield divergent approach. This synthesis is amenable to the design and development of new biomaterials that are of interest for a variety of medical applications, including tissue engineering. In a novel application, photocrosslinkable dendrimers are used to seal large corneal lacerations.
Optimal monetary policy in an economy with inflation persistence

Abstract This paper studies optimal monetary policy in a model where inflation is persistent. Two types of price setters are assumed to exist. One acts rationally given Calvo-type constraints on price setting. The other type sets prices according to a rule-of-thumb. This results in a Phillips curve with both a forward-looking term and a backward-looking term. The Phillips curve nests a standard purely forward-looking Phillips curve as well as a standard purely backward-looking Phillips curve as special cases. A cost push supply shock is derived from microfoundations by adding a time varying income tax and by making the elasticity of substitution between goods stochastic. A central bank loss function for this model is derived from a second-order Taylor approximation of the household's welfare function. Optimal monetary policy for different relative values of the forward- and backward-looking terms is then analyzed for both the commitment case and the case of discretion.