cssi/SciSciGPT-SciSciNet huggingface dataset:
Facile syntheses of oxazolines and thiazolines with N-acylbenzotriazoles under microwave irradiation.

Microwave reactions of 2-amino-2-methyl-1-propanol (2) or 2-aminoethanethiol hydrochloride (4) with readily available N-acylbenzotriazoles 1a−j in the presence of SOCl2 produced 2-substituted 2-oxazolines 3a−j in 84−98% yields and 2-substituted thiazolines 5a−i in 85−97% yields, respectively. With use of this method chiral oxazoline 6, bisoxazoline 7, bisthiazoline 8, and 5,6-dihydro-4H-1,3-oxazines 9 or 10 have also been prepared in 82−96% yields. These results demonstrate a new application of N-acylbenzotriazoles in the preparation of oxazolines and thiazolines under mild conditions and short reaction times with microwave irradiation.
Strength Degradation of Soda‐Lime‐Silica Glass During Dynamic Loading

The strength degradation of soda-lime-silica glass during dynamic loading was studied by using a fracture-mechanics approach. The theoretical and experimental results indicate that subcritical flaw growth during loading causes the strength degradation.
Nonlinear Filtering of Diffusion Processes in Correlated Noise: Analysis by Separation of Variables

Abstract. An approximation to the solution of a stochastic parabolic equation is constructed using the Galerkin approximation followed by the Wiener chaos decomposition. The result is applied to the nonlinear filtering problem for the time-homogeneous diffusion model with correlated noise. An algorithm is proposed for computing recursive approximations of the unnormalized filtering density and filter, and the errors of the approximations are estimated. Unlike most existing algorithms for nonlinear filtering, the real-time part of the algorithm does not require solving partial differential equations or evaluating integrals. The algorithm can be used for both continuous and discrete time observations. \par
Coping With Ignorance: Unforeseen Contingencies and Non-Additive Uncertainty

In real-life decision problems, decision makers are never provided with the necessary background structure: the set of states of the world, the outcome space, the set of actions. They have to devise all these by themselves. I model the (static) choice problem of a decision maker (DM) who is aware that her perception of the decision problem is too coarse, as for instance when there might be unforeseen contingencies. I make a “bounded rationality'' assumption on the way the DM deals with this difficulty, and then I show that imposing standard subjective expected utility axioms on her preferences only implies that they can be represented by a (generalized) expectation with respect to a non-additive measure, called a belief function. However, the axioms do have strong implications for how the DM copes with the type of ignorance described above. Finally, I show that some decision rules that have been studied in the literature can be obtained as a special case of the model presented here (though they have to be interpreted differently).
Permutation Testing in the Presence of Polygenic Variation

This article discusses problems with and solutions to performing valid permutation tests for quantitative trait loci in the presence of polygenic effects. Although permutation testing is a popular approach for determining statistical significance of a test statistic with an unknown distribution--for instance, the maximum of multiple correlated statistics or some omnibus test statistic for a gene, gene-set, or pathway--naive application of permutations may result in an invalid test. The risk of performing an invalid permutation test is particularly acute in complex trait mapping where polygenicity may combine with a structured population resulting from the presence of families, cryptic relatedness, admixture, or population stratification. I give both analytical derivations and a conceptual understanding of why typical permutation procedures fail and suggest an alternative permutation-based algorithm, MVNpermute, that succeeds. In particular, I examine the case where a linear mixed model is used to analyze a quantitative trait and show that both phenotype and genotype permutations may result in an invalid permutation test. I provide a formula that predicts the amount of inflation of the type 1 error rate depending on the degree of misspecification of the covariance structure of the polygenic effect and the heritability of the trait. I validate this formula by doing simulations, showing that the permutation distribution matches the theoretical expectation, and that my suggested permutation-based test obtains the correct null distribution. Finally, I discuss situations where naive permutations of the phenotype or genotype are valid and the applicability of the results to other test statistics.
Leading Indicators of Regional Cotton Acreage Response: Structural and Time Series Modeling Results

Resurgent cotton production compels better acreage forecasts for planning seed, chemical, and other input requirements. Structural models describe leading acreage response indicators, and forecasts are compared to time-series models. Cotton price, loan rate, deficiency payments, lagged corn acreage, the PIK program, and previous cotton yield significantly influence cotton acreage response.
Thermal characterization of aerospace structures

Predictingthethermalperformanceofcomplexaerospacestructuresrequiresaccurateknowledgeofthethermal properties associated with the structure. It is desired, in this case, to measure the in situ properties of a complex as-built structure, not only to capture the thermal properties of each component but also to capture interaction of components in the as-built structure. The overall goal of this study was, therefore, to develop and implement a nondestructive methodology to estimate the thermal properties associated with a complex aerospace structure. The structure considered was an outer wing subcomponent design for the high-speed civil transport made from four different materials, including a honeycomb blanket. The thermal properties sought included both effective and individual material through-the-thickness thermal conductivities and volumetric heat capacities (product of density and specie c heat ) and the in-plane thermal conductivities of each material in the structure. In the estimation procedureanobjectivefunctioncontaining boththeoreticalandexperimentaltemperaturehistorieswas minimizedusing ageneticalgorithm.One-dimensionalexperimentswereimplemented toestimatethethrough-thethicknessthermalconductivitiesand volumetricheatcapacities, andtwo-dimensionalexperimentswereconducted to estimate the in-plane conductivities. These properties were successfully estimated despite the high degree of correlation and low sensitivity evident for many of the properties.
Study of fluorocarbonyls for the Baylis-Hillman reaction

A study of the effect of fluorine substitution in Baylis-Hillman reactions of various fluorocarbonyl partners with acrolein, methyl vinyl ketone, ethyl acrylate, and acrylonitrile has been made.
The Wisdom of Competitive Crowds

When several individuals are asked to forecast an uncertain quantity, they often face implicit or explicit incentives to be the most accurate. Despite the desire to elicit honest forecasts, such competition induces forecasters to report strategically and nontruthfully. The question we address is whether the competitive crowd's forecast (the average of strategic forecasts) is more accurate than the truthful crowd's forecast (the average of truthful forecasts from the same forecasters). We analyze a forecasting competition in which a prize is awarded to the forecaster whose point forecast is closest to the actual outcome. Before reporting a forecast, we assume each forecaster receives two signals: one common and one private. These signals represent the forecasters' past shared and personal experiences relevant for forecasting the uncertain quantity of interest. In a set of equilibrium results, we characterize the nature of the strategic forecasts in this game. As the correlation among the forecasters' priva...
Development of a Long Life Triggered Spark Gap

In a wide variety of high voltage applications, a triggered spark gap is a critical component for the switching of capacitive energy. Whether it is for the purpose of equipment protection or as a series switch, the destructive nature of this application renders the spark gap a limited lifetime device. System parameters such as stored energy, peak current, and charge transfer can all play a significant role in limiting the lifetime of the spark gap; however, these parameters are often fixed for a specific application, thus setting a limit to the attainable life of the spark gap. The following paper discusses experimental results of a study to increase the operation lifetime of a gas filled sealed trigatron spark gap. Parameters such as electrode spacing, gas pressure, gas mixture, and electrode conditioning were examined to quantify improvements in the lifetime of the spark gap. Testing was performed at 45.5 kV with 10 kJ of stored energy discharged at a rate of 300 discharges per day. Conclusions are made as to the effect each design parameter has on extending the lifetime of the spark gap.
The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis.

Covering: 2010–2014 Following the turn of the millennium, the role of asymmetric covalent organocatalysis has developed into a scalable, synthetic paradigm galvanizing the synthetic community toward utilization of these methods toward more practical, metal-free syntheses of natural products. A myriad of reports on asymmetric organocatalytic modes of substrate activation relying on small, exclusively organic molecules are delineating what has now become the multifaceted field of organocatalysis. In covalent catalysis, the catalyst and substrate combine to first form a covalent, activated intermediate that enters the catalytic cycle. Following asymmetric bond formation, the chiral catalyst is recycled through hydrolysis or displacement by a pendant group on the newly formed product. Amine- and phosphine-based organocatalysts are the most common examples that have led to a vast array of reaction types. This Highlight provides a brief overview of covalent modes of organocatalysis and applications of scalable versions of these methods applied to the total synthesis of natural products including examples from our own laboratory.
Targeting microparticles to select tissue via radiation induced upregulation of endothelial cell adhesion molecules

The up-regulation of certain endothelial cell adhesion molecules in tissue that has been irradiated for therapeutic purposes provides a potential avenue for targeting drugs to select tissue. Microspheres were coated with a mAb to ICAM-1 and the level of adhesion of the anti-ICAM-1 microspheres to irradiated tissue in vitro and in vivo was quantified. Under in vitro flow conditions, the number of adherent microspheres on irradiated human umbilical vein endothelial cells (HUVEC) was 4.5/spl plusmn/0.9 times that of control; this ratio could be enhanced by increasing ligand density on the surface of the microspheres, adding RBC to the suspending media, or reducing shear rate. In vivo in a rat cranial window model, the number of adherent anti-ICAM-1 microspheres in irradiated cerebral tissue was 13 times that of IgG microspheres at 48 hr post-irradiation. In locally irradiated animals, the number of adhering microspheres in unirradiated tissue remained at the basal level.
Fat Tails and the Social Cost of Carbon

At high enough greenhouse gas (GHG) concentrations, climate change might conceivably cause catastrophic damages with small but nonnegligible probabilities. Other things being equal, this should lower the discount rate used to evaluate mitigation-investment decisions and raise the social cost of carbon (SCC). If the bad tail of climate damages is sufficiently fat with probability, and if the utility function has relative risk aversion greater than one, then (at least in theory for at least some formulations) this insurance-like catastrophe-reducing aspect of mitigation investments can be very powerful. In the most extreme limit this tail-hedge insurance effect can be infinitely strong and can dominate the economic analysis by making the SCC infinite. This kind of extreme (and empirically unbelievable) limiting result is a version of what I have previously labeled the “dismal theorem.” 1 In this paper I use the simplest possible model to lay bare the basic structure of the argument. I then attempt to place the underlying issues in a balanced perspective. The “dismal theorem” of an infinite SCC is a theoretical limiting result, which relies on particular assumptions that may or may not have actual relevance for climatechange policy depending upon the interaction of a variety of empirical factors, functional forms, and parameter values. I argue that the main value of the “dismal theorem” is to serve as a warning flag that a credible economic analysis of climate change should seriously consider extreme tail values of damages and their associated probabilities because they may have the potential to increase the SCC significantly.
Performance-based regulation: Enterprise responsibility for reducing death, injury, and disease caused by consumer products

This article offers a bold new idea for confronting the staggering level of death, injury, and disease caused by five consumer products: cigarettes, alcohol, guns, junk food, and motor vehicles. Business leaders try to frame these negative out- comes as "collateral damage" that is someone else's problem. That framing not only is morally objectionable but also overlooks the possibility that, with proper prodding, industry could substantially lessen these public health disasters. I seek to reframe the public perception of who is responsible and propose to deploy a promising approach called "performance-based regulation" to combat the problem. Performance-based regulation would impose on manufacturers a legal obligation to reduce the negative social costs of their products. Rather than involving them in litigation or forcing them to operate differently (as "command-and-control" regimes do), performance-based regulation allows the firms to determine how best to decrease bad public health con - sequences. Like other public health strategies, performance-based regulation focuses on those who are far more likely than individual consumers to achieve real gains. Analogous to a tax on causing harm that exceeds a threshold level, performance- based regulation seeks to harness private initiative in pursuit of the public good. Postindustrial societies face a wide range of serious public health problems that arise from a combination of consumer-product characteristics and indi- vidual behavior. Products that cause great harm include cigarettes, alcohol, guns, junk food, and motor vehicles. These products often combine risks to users with risks to others. Together they account for a staggering number
Adiabatic Heating of Contracting Turbulent Fluids

Turbulence influences the behavior of many astrophysical systems, frequently by providing non-thermal pressure support through random bulk motions. Although turbulence is commonly studied in systems with constant volume and mean density, turbulent astrophysical gases often expand or contract under the influence of pressure or gravity. Here, we examine the behavior of turbulence in contracting volumes using idealized models of compressed gases. Employing numerical simulations and an analytical model, we identify a simple mechanism by which the turbulent motions of contracting gases "adiabatically heat," experiencing an increase in their random bulk velocities until the largest eddies in the gas circulate over a Hubble time of the contraction. Adiabatic heating provides a mechanism for sustaining turbulence in gases where no large-scale driving exists. We describe this mechanism in detail and discuss some potential applications to turbulence in astrophysical settings.
Stereodivergent total asymmetric synthesis of polyhydroxylated pyrrolidines via tandem allylic epoxidation and intramolecular cyclization reactions

Epoxidation of the allylic alcohols 10 and 11 using the VO(acac)2/t-BuOOH system followed by an intramolecular 5-exo cyclization of the resulting δ-epoxycarbamates 12, 13, 18, and 19 has been shown to provide a general and efficient solution for the asymmetric synthesis of polyhydroxy pyrrolidines. The requisite vicinal amino alcohol functionality was enantio-/regio-selectively installed by the Os-catalyzed asymmetric aminohydroxylation reaction of the designed achiral olefin 6.
A Hybrid Eulerian–Lagrangian Approach for Thickness, Correspondence, and Gridding of Annular Tissues

We present a novel approach to efficiently compute thickness, correspondence, and gridding of tissues between two simply connected boundaries. The solution of Laplace's equation within the tissue region provides a harmonic function whose gradient flow determines the correspondence trajectories going from one boundary to the other. The proposed method uses and expands upon two recently introduced techniques in order to compute thickness and correspondences based on these trajectories. Pairs of partial differential equations are efficiently computed within an Eulerian framework and combined with a Lagrangian approach so that correspondences trajectories are partially constructed when necessary. Examples are presented in order to compare the performance of this method with those of the pure Lagrangian and pure Eulerian approaches. Results show that the proposed technique takes advantage of both the speed of the Eulerian approach and the accuracy of the Lagrangian approach
Ternary expansions of powers of 2

Erd.os asked how frequently 2n has a ternary expansion that omits the digit 2. He conjectured that this holds only for finitely many values of n.We generalize this question to consider iterates of two discrete dynamical systems. The first considers truncated ternary expansions of real sequences xn(�E) = �E2n, where �E > 0 is a real number, along with its untruncated version, whereas the second considers 3-adic expansions of sequences yn(�E) = �E2n, where �E is a 3-adic integer. We show in both cases that the set of initial values having infinitely many iterates that omit the digit 2 is small in a suitable sense. For each nonzero initial value we obtain an asymptotic upper bound as k�¨�� on the number of the first k iterates that omit the digit 2. We also study auxiliary problems concerning the Hausdorff dimension of intersections of multiplicative translates of 3-adic Cantor sets.
Time-stretched short-time Fourier transform

The authors propose and demonstrate the time-stretched short-time Fourier transform (TS-STFT) technique to overcome the limitation of an analog-digital converter (ADC) in the time-frequency analysis of ultrafast signals. Experimentally, the time-frequency analysis of highly chirped RF signals, with a chirp rate as high as 350 GHz/ns, is demonstrated. An effective real-time sampling rate of 320 GSa/s is achieved. Time stretching enhances the analog bandwidth and the effective sampling rate of the ADC and enables measurement of the instantaneous behavior of highly nonstationary ultrawideband signals.
Introduction to modeling of transformers and coupled inductors

A tutorial paper is presented on modeling and design of transformers and coupled inductors. Beginning with a brief review of electromagnetic laws and magnetic circuit models, the magnetic and electric models of transformers and coupled inductors are developed, including both magnetizing and leakage effects. It is shown that while the voltage waveforms on the windings are primarily related by the turns ratio for both devices, the winding currents of transformers and coupled inductors are determined by very different mechanisms. An integrated structure with both transformer and coupled inductor on the same core is also discussed, as well as the special case of the coupled inductor used on a multiple-output transformer-isolated converter. >
Review Essay: The Working Papers of the Socio‐Behavioral Group, Mental Retardation Research Center, UCLA

Researchers at the Socio-Behavioral Group of the Mental Retardation Research Center at the University of California, Los Angeles, have completed 25 working papers in which they discuss life experiences of mentally retarded individuals from a cultural perspective. Many of the papers contain insights pertinent to anthropologists investigating school settings. In this article, I will present a history and review of the work of the Socio-Behavioral Group and discuss the papers most directly pertinent to educational researchers. The roots of the research reviewed here go back to the early 1960s with anthropologist Robert Edgerton's two-year study of mentally retarded individuals (1967). At the time, mental health practitioners in California had begun a process of "deinstitutionalization" of the retarded, releasing inmates from their institutions into smaller community facilities or homes. A follow-up study conducted by Edgerton 12 years later indicated the individuals were functioning competently and showed little dependence on benefactors. In the early 1970s, Edgerton and others established the Socio-Behavioral Group to conduct long-term studies of mentally retarded individuals. They also began a new study of the experiences of retarded individuals living in community residential facilities. The results of this research indicated that the lives of mentally retarded individuals in these small scale institutions were "unnecessarily restricted":
A New Type of Heteropolyoxometalates formed from Lacunary Polyoxotungstate Ions and Europium or Yttrium Cations.

Four lacunary PW9 O349- ions (blue polyhedra) are held together by eight MIII (M = Y, Eu) ions and seven W atoms that form a [M8 W7 O30 ]6+ network (center) in the novel heteropolyoxometalates [(PM2 W10 O38 )4 (W3 O14 )]30- . In the solid state, the anions interact strongly with K+ countercations, which thus play a role in the formation of this particular structure.
Catalytic intermolecular reductive coupling of enones and alkynes

A nickel-catalyzed intermolecular reductive coupling of enones and alkynes has been developed as a novel entry to γ,δ-unsaturated ketones. The process does not require formation of a vinyl organometallic, and a variety of functional groups including free hydroxyls and esters are tolerated. A number of features that complement existing copper-mediated processes are highlighted.
1,2-Shifts of Hydrogen Atoms in Aryl Radicals

An energy barrier on the order of 60 kcal/mol is predicted for the 1,2-shift of hydrogen atoms in aryl radicals. Such rearrangements are, therefore, not expected to occur under ordinary laboratory conditions, but they should be prevalent in the aryl radicals formed during combustion, flash vacuum pyrolysis, and other high-temperature gas-phase processes. As a demonstration of this rearrangement, the 2-benzo[c]phenanthryl radical (1) was generated by flash vacuum pyrolysis of the corresponding aryl bromide (9). A 1,2-shift of hydrogen out of the sterically congested cove region of 1, followed by cyclization and rearomatization of the resulting radical (Scheme 1), is proposed to explain the observation of benzo[ghi]fluoranthene (4) as the dominant monomeric product formed. Under the same conditions, [1,3,4,5-2H4]-2-bromobenzo[c]phenanthrene (13) gives [1,2,3,4-2H4]-benzo[ghi]fluoranthene (15) as the dominant monomeric product (Scheme 6), in accord with the expectation of a deuterium atom 1,2-shift.
The Standing Pool of Genomic Structural Variation in a Natural Population of Mimulus guttatus

Major unresolved questions in evolutionary genetics include determining the contributions of different mutational sources to the total pool of genetic variation in a species, and understanding how these different forms of genetic variation interact with natural selection. Recent work has shown that structural variants (SVs) (insertions, deletions, inversions, and transpositions) are a major source of genetic variation, often outnumbering single nucleotide variants in terms of total bases affected. Despite the near ubiquity of SVs, major questions about their interaction with natural selection remain. For example, how does the allele frequency spectrum of SVs differ when compared with single nucleotide variants? How often do SVs affect genes, and what are the consequences? To begin to address these questions, we have systematically identified and characterized a large set of submicroscopic insertion and deletion (indel) variants (between 1 and 200 kb in length) among ten inbred lines from a single natural population of the plant species Mimulus guttatus. After extensive computational filtering, we focused on a set of 4,142 high-confidence indels that showed an experimental validation rate of 73%. All but one of these indels were less than 200 kb. Although the largest were generally at lower frequencies in the population, a surprising number of large indels are at intermediate frequencies. Although indels overlapping with genes were much rarer than expected by chance, approximately 600 genes were affected by an indel. Nucleotide-binding site leucine-rich repeat (NBS-LRR) defense response genes were the most enriched among the gene families affected. Most indels associated with genes were rare and appeared to be under purifying selection, though we do find four high-frequency derived insertion alleles that show signatures of recent positive selection.
C2-Symmetric Copper(II) Complexes as Chiral Lewis Acids. Scope and Mechanism of the Catalytic Enantioselective Aldol Additions of Enolsilanes to Pyruvate Esters

The C2-symmetric (S,S)-tert-butyl-bis(oxazolinyl)Cu(OTf)2 complex (1a) has been shown to catalyze the enantioselective aldol reaction between α-keto esters and silylketene acetals or enolsilanes with enantioselectivities ranging from 93 to 99%. With substituted silylketene acetals, syn reaction diastereoselection ranging from 90:10 to 98:2 and enantioselectivities ranging from 93 to 98% are observed. High levels of carbonyl regioselectivity (98:2), diastereoselectivity (93:7), and enantioselectivity (97% ee) are also observed in the aldol addition to 2,3-pentanedione. In all instances, the aldol adducts are generated in high yield and in excellent enantiomeric excess using as little as 1 mol % of the chiral complex 1a. Mechanistic insight into the pyruvate aldol reaction has also been gained. Silyl crossover experiments demonstrate that the silyl-transfer step is intermolecular. Based upon these results, TMSOTf has been identified as an addend to accelerate these reactions. Furthermore, solvent was shown ...
Kalman Filter-Based Integration of DGPS and Vehicle Sensors for Localization

We present a position estimation scheme for cars based on the integration of global positioning system (GPS) with vehicle sensors. The aim is to achieve enough accuracy to enable in vehicle cooperative collision warning, i.e., systems that provides warnings to drivers based on information about the motions of neighboring vehicles obtained by wireless communications from those vehicles, without use of ranging sensors. The vehicle sensors consist of wheel speed sensors, steering angle encoder, and a fiber optic gyro. We fuse these in an extended Kalman filter. The process model is a dynamic bicycle model. We present data from about 60 km of driving in urban environments including stops, intersection turns, U-turns, and lane changes, at both low and high speeds. The data show the filter estimates position, speed, and heading with the accuracies required by cooperative collision warning in all except two kinds of settings. The data also shows GPS and vehicle sensor integration through a bicycle model compares favorably with position estimation by fusing GPS and inertial navigation system (INS) through a kinematic model.
Partial Distributional Policy Effects

In this paper, we propose a method to evaluate the effect of a counterfactual change in the unconditional distribution of a single covariate on the unconditional distribution of an outcome variable of interest. Both fixed and infinitesimal changes are considered. We show that such effects are point identified under general conditions if the covariate affected by the counterfactual change is continuously distributed, but are typically only partially identified if its distribution is discrete. For the latter case, we derive informa tive bounds, making use of the available information. We also discuss estimation and inference.
Electrical conductivity of pure and doped nanocrystalline cerium oxide

The authors have previously shown that dense nanocrystalline CeO{sub 24} of approximately 10 nm grain size exhibits enhanced electrical conductivity ad an enthalpy of reduction that is more than 2.4 eV lower than that for conventional ceria. These effects were attributed to preferential interface reduction. In this work, the authors investigated the relationship between interfacial area, heat treatment conditions, and conductivity by varying the grain size of dense samples through annealing at various temperatures. It is shown that the conductivity does not scale in direct proportion to interfacial area. Moderate temperature (700 C) anneals which change the grain size by only a few nanometers reduce the conductivity by three orders of magnitude. It is suggested that atomistic relaxation occurs at the interfaces, and eliminates many low energy defect sites.
Sampling algebraic sets in local intrinsic coordinates

Numerical data structures for positive dimensional solution sets of polynomial systems are sets of generic points cut out by random planes of complementary dimension. We may represent the linear spaces defined by those planes either by explicit linear equations or in parametric form. These descriptions are respectively called extrinsic and intrinsic representations. While intrinsic representations lower the cost of the linear algebra operations, we observe worse condition numbers. In this paper we describe the local adaptation of intrinsic coordinates to improve the numerical conditioning of sampling algebraic sets. Local intrinsic coordinates also lead to a better step size control. We illustrate our results with Maple experiments and computations with PHCpack on some benchmark polynomial systems.
Light sterile neutrinos and short baseline neutrino oscillation anomalies

We study two possible explanations for short baseline neutrino oscillation anomalies, such as the LSND and MiniBooNE anti-neutrino data, and for the reactor anomaly. The first scenario is the mini-seesaw mechanism with two eV-scale sterile neutrinos. We present both analytic formulas and numerical results showing that this scenario could account for the short baseline and reactor anomalies and is consistent with the observed masses and mixings of the three active neutrinos. We also show that this scenario could arise naturally from an effective theory containing a TeV-scale VEV, which could be related to other TeV-scale physics. The minimal version of the mini-seesaw relates the active-sterile mixings to five real parameters and favors an inverted hierarchy. It has the interesting property that the effective Majorana mass for neutrinoless double beta decay vanishes, while the effective masses relevant to tritium beta decay and to cosmology are respectively around 0.2 and 2.4 eV. The second scenario contains only one eV-scale sterile neutrino but with an effective non-unitary mixing matrix between the light sterile and active neutrinos. We find that though this may explain the anomalies, if the non-unitarity originates from a heavy sterile neutrino with a large (fine-tuned) mixing angle, this scenario is highly constrained by cosmological and laboratory observations.
Environment and Process Adaptive Low Power Wireless Baseband Signal Processing Using Dual Real-Time Feedback

As technology scales below the 45nm CMOS technology node, RF front ends and baseband processors will need to be aggressively overdesigned to work reliably under worst case channel (environment) conditions as well as worst case manufacturing variations. In this paper, a new dual feedback based design approach is proposed that allows the baseband unit of a wireless OFDM system to adapt dynamically to channel conditions as well as manufacturing process variations. Two nested feedback control loops are used. The first allows the baseband SNR to increase when channel conditions are good and vice versa by modulating system wordlength. The second modulates the system supply voltage in response to the resulting changing wordlength values. Both feedback loops are designed to allow the processor to operate at the minimum power consumption possible without exceeding a specified overall bit error rate across all channel noise and process variability conditions.
Qualitative spatial reasoning about sketch maps

Sketch maps are an important spatial representation used in many geospatial-reasoning tasks. This article describes techniques we have developed that enable software to perform humanlike reasoning about sketch maps. We illustrate the utility of these techniques in the context of nuSketch Battlespace, a research system that has been successfully used in a variety of experiments. After an overview of the nuSketch approach and nuSketch Battlespace, we outline the representations of glyphs and sketches and the nuSketch spatial reasoning architecture. We describe the use of qualitative topology and Voronoi diagrams to construct spatial representations, and explain how these facilities are combined with analogical reasoning to provide a simple form of enemy intent hypothesis generation.
Highly Oriented Molecular Ag Nanocrystal Arrays

Orientational ordering of faceted nanocrystals in nanocrystal arrays has been directly observed for the first time, by use of transmission electron microscopy imaging and diffraction to resolve the structure of thin molecular-crystalline films of silver nanocrystals passivated by alkylthiolate self-assembled monolayers. The type of ordering found is determined by the nanocrystal’s faceted morphology, as mediated by the interactions of surfactant groups tethered to the facets on neighboring nanocrystals. Orientational ordering is crucial for the understanding of the fundamental properties of quantum-dot arrays, as well as for their optimal utilization in optical and electronic applications.
Catalytic Diastereo- and Enantioselective Annulations between Transient Nitrosoalkenes and Indoles

Caught in transition: an efficient catalytic system is the key to the successful development of the first highly diastereo- and enantioselective annulation reaction between indoles and transient nitrosoalkenes. This robust reaction affords structurally unique architectures with up to three new chiral centers. The products can be readily elaborated into other indoline-based chiral heterocyclic motifs, including those of pyrrolidinoindoline alkaloids.
Flows and joins of metric spaces

We introduce the functor ◦ which assigns to every metric space X its symmetric join ◦X. As a set, ◦X is a union of intervals connecting ordered pairs of points in X. Topologically, ◦X is a natural quotient of the usual join of X with itself. We define an Isom(X)–invariant metric d∗ on ◦X. Classical concepts known for H n and negatively curved manifolds are defined in a precise way for any hyperbolic complex X, for example for a Cayley graph of a Gromov hyperbolic group. We define a double difference, a cross-ratio and horofunctions in the compactification ¯ X = X ⊔ ∂X. They are continuous, Isom(X)–invariant, and satisfy sharp identities. We characterize the translation length of a hyperbolic isometry g ∈ Isom(X). For any hyperbolic complex X, the symmetric join ◦ ¯ X of ¯ X and the (generalized) metric d∗ on it are defined. The geodesic flow space F(X) arises as a part of ◦ ¯ X. (F(X), d∗) is an analogue of (the total space of) the unit tangent bundle on a simply connected negatively curved manifold. This flow space is defined for any hyperbolic complex X and has sharp properties. We also give a construction of the asymmetric join X ◦ Y of two metric spaces. These concepts are canonical, i.e. functorial in X, and involve no “quasi”-language. Applications and relation to the Borel conjecture and others are discussed. AMS Classification numbers Primary: 20F65, 20F67, 37D40, 51F99, 57Q05 Secondary: 57M07, 57N16, 57Q91, 05C25
A genetically targeted optical sensor to monitor calcium signals in astrocyte processes.

Calcium signaling is studied as a potential form of astrocyte excitability that may control astrocyte involvement in synaptic and cerebrovascular regulation. Fundamental questions remain unanswered about astrocyte calcium signaling, as current methods can not resolve calcium in small volume compartments, such as near the cell membrane and in distal cell processes. We modified the genetically encoded calcium sensor GCaMP2 with a membrane-tethering domain, Lck, increasing the level of Lck-GCaMP2 near the plasma membrane tenfold as compared with conventional GCaMP2. Using Lck-GCaMP2 in rat hippocampal astrocyte-neuron cocultures, we measured near-membrane calcium signals that were evoked pharmacologically or by single action potential– mediated neurotransmitter release. Moreover, we identified highly localized and frequent spontaneous calcium signals in astrocyte somata and processes that conventional GCaMP2 failed to detect. Lck-GCaMP2 acts as a genetically targeted calcium sensor for monitoring calcium signals in previously inaccessible parts of astrocytes, including fine processes.
Assessing Learning-Centered Leadership: Connections to Research, Professional Standards, and Current Practices

Effective school leadership is key to students' academic success. But the development of effective school leadership has been seriously hampered by the lack of technically sound tools to assess and monitor leaders' performance. This article presents the research base and conceptual framework for a leadership assessment instrument under development.
New Rotation-Balance Apparatus for Measuring Airplane Spin Aerodynamics in the Wind Tunnel

An advanced rotation-balance apparatus has been developed for the Ames 12-ft Pressure Wind Tunnel to study the effects of spin rate, angles of attack and sideslip, and, particularly, Reynolds number on the aerodynamics of fighter and general aviation aircraft in a steady spin. Angles of attack to 100 deg and angles of sideslip to 30 deg are possible with spin rates to 42 rad/s (400 rpm) and Reynolds numbers to 30x 106/m on fighter models with wing spans that are typically 0.7 m. A complete description of the new rotation-balance apparatus, the sting/balance/model assembly, and the operational capabilities is given. Nomenclature A = body reference area, ird214 b = wing span (0.457 m for Figs. 3-6) Cy = body side force/qA d = diameter of centerbody (0.0762 m for Figs. 3-6) M = freestream Mach number q — freestream dynamic pressure Rd — Reynolds number based on d V — freestream velocity as — sting angle (Figs. 11 and 12) a =angle of attack /3 = angle of sideslip a = angle between freestream velocity vector and body longitudinal axis
Unsteady Thin Airfoil Theory for Transonic Flows with Embedded Shocks

A simple modification of classical unsteady thin airfoil theory is presented which accounts for the presence and induced motion of the embedded partial chord shock waves which appear at supercritical transonic Mach numbers. The basic model is found to be divergent at zero frequency because of an unbounded growth of the shock excursion amplitude. This behavior is eliminated by introducing a term associated with the mean flow Mach number gradient near the shock. Numerical results are given for the loads induced by an oscillating flap. LASSICAL unsteady thin airfoil theory fails for low frequencies at the subsonic freestream Mach number at which local supersonic flow first occurs. The main cause of this sudden failure is the formation of a shock wave, which shields the forward region of the airfoil from aft generated disturbances. In the present study,l a simple modification of classical thin airfoil theory is given which accounts for the presence and induced motion of such shocks. Predicted airloads are shown to be in favorable agreement with both experimental observations and finite difference calculations. We assume that the unsteady flow is generated by in- finitesimal harmonic oscillations of an airfoil which is suf- ficiently thin and at sufficiently small mean angles of attack that the transonic small disturbance approximation is valid. The unsteady problem can then be linearized about the steady flow, taking due account of the (small amplitude) displacement of any embedded shocks. The linearized un- steady problem has been formulated for an arbitrary three dimensional planar lifting surface in an earlier paper.2 The linearized equations of motion depend through various coefficients on the steady local Mach number M0 (jc), which in general varies in some complicated way throughout the flowfield. Unless the functional form of M0 is very simple, the boundary value problem for the unsteady flow field must be solved by purely numerical techniques. This has been attempted using finite difference methods by Weatherill et al.3 and Traci et al. 4 However, neither of these studies properly accounted for the interaction between the embedded shocks and the unsteady disturbance field. (Of course, this issue does not arise in nonlinear formulations of the unsteady problem, in which the "interaction" is implicit; flow with oscillating shocks has been successfully computed from the nonlinear small disturbance equation by, for example, Ballhaus and Goor jian.5) An alternative to direct numerical methods is to ap- proximate the steady Mach number distribution M0(x) in such a way that analytical or semianalytica l methods can be applied. Classical theory, where M0 is set equal to the freestream Mach number M^, is, of course, one example. The
Reconstructing uniformly attenuated rotating slant-hole SPECT projection data using the DBH method

This work applies a previously developed analytical algorithm to the reconstruction problem in a rotating multi-segment slant-hole (RMSSH) SPECT system. The RMSSH collimator has greater detection efficiency than the parallel-hole collimator with comparable spatial resolution at the expense of limited common volume-of-view (CVOV) and is therefore suitable for detecting low-contrast lesions in breast, cardiac and brain imaging. The absorption of gamma photons in both the human breast and brain can be assu- med to follow an exponential rule with a constant attenuation coefficient. In this work, the RMSSH SPECT data of a digital NCAT phantom with breast attachment are modeled as the uniformly attenuated Radon transform of the activity distribution. These data are reconstructed using an analytical algorithm called the DBH method, which is an acronym for the procedure of differentiation backprojection followed by a finite weighted inverse Hilbert transform. The projection data are first differentiated along a specific direction in the projection space and then backprojected to the image space. The result from this first step is equal to a one-dimensional finite weighted Hilbert transform of the object; this transform is then numerically inverted to obtain the reconstructed image. With the limited CVOV of the RMSSH collimator, the detector captures gamma photon emissions from the breast and from parts of the torso. The simulation results show that the DBH method is capable of exactly reconstructing the activity within a well-defined region-of-interest (ROI) within the breast if the activity is confined to the breast or if the activity outside the CVOV is uniformly attenuated for each measured projection, while a conventional filtered backprojection algorithm only reconstructs the high frequency components of the activity function in the same geometry.
Financing Public Investment through Foreign Aid: Consequences for Economic Growth and Welfare

The paper develops a theoretical framework for understanding the mechanism through which foreign aid affects macroeconomic performance. The authors find that the long-run impact of an aid program and the nature of the transitional dynamics it generates depend crucially on (i) the elasticity of substitution in production, (ii) whether the aid flow is tied to investment activity or not, (iii) how the recipient government chooses to react to the flow of external assistance, and (iv) whether the aid program is permanent or temporary. Structural characteristics of the recipient are important in determining the extent to which external assistance can aid growth and welfare.
Manifold-theoretic compactifications of configuration spaces

We present new definitions for and give a comprehensive treatment of the canonical compactification of configuration spaces due to Fulton–MacPherson and Axelrod–Singer in the setting of smooth manifolds, as well as a simplicial variant of this compactification initiated by Kontsevich. Our constructions are elementary and give simple global coordinates for the compactified configuration space of a general manifold embedded in Euclidean space. We stratify the canonical compactification, identifying the difieomorphism types of the strata in terms of spaces of configurations in the tangent bundle, and give completely explicit local coordinates around the strata as needed to define a manifold with corners. We analyze the quotient map from the canonical to the simplicial compactification, showing it is a homotopy equivalence. Using global coordinates we define projection maps and diagonal maps, which for the simplicial variant satisfy cosimplicial identities.
High contrast imaging testbed for the Terrestrial Planet Finder coronagraph

One of the architectures under consideration for Terrestrial Planet Finder (TPF) is a visible coronagraph. To achieve TPF science goals, the coronagraph must have extreme levels of wavefront correction (less than 1 /spl Aring/ rms over controllable spatial frequencies) and stability to get the necessary suppression of diffracted starlight (10/sup -10/ contrast). The High Contrast Imaging Testbed is the TPF platform for laboratory validation of key coronagraph technologies, as well as demonstration of a flight-traceable approach to coronagraph implementation. Various wavefront sensing approaches are under investigation on the testbed, with wavefront control provided by a precision high actuator density deformable mirror. Diffracted light control is achieved through a combination of an occulting or apodizing mask and stop; many concepts exist for these components and are explored. Contrast measurements on the testbed establishes the technical feasibility of TPF requirements, while model and error budget validation are demonstrate implementation viability. This paper describes the current testbed design and preliminary experimental results.
World Oil: Market or Mayhem?

The world oil market is regarded by many as a puzzle. Why are oil prices so volatile? What is OPEC and what does OPEC do? Where are oil prices headed in the long run? Is “peak oil” a genuine concern? Why did oil prices spike in the summer of 2008, and what role did speculators play? Any attempt to answer these questions must be informed and disciplined by economics. Such is the purpose of this essay: to illuminate recent developments in the world oil market from the perspective of economic theory.