cssi/SciSciGPT-SciSciNet huggingface dataset:
Uniform test of algorithmic randomness over a general space

The algorithmic theory of randomness is well developed when the underlying space is the set of finite or infinite sequences and the underlying probability distribution is the uniform distribution or a computable distribution. These restrictions seem artificial. Some progress has been made to extend the theory to arbitrary Bernoulli distributions (by Martin-Lof) and to arbitrary distributions (by Levin). We recall the main ideas and problems of Levin's theory, and report further progress in the same framework. The issues are the following: • Allow non-compact spaces (like the space of continuous functions, underlying the Brownian motion). • The uniform test (deficiency of randomness) dp(x) (depending both on the outcome x and the measure P) should be defined in a general and natural way. • See which of the old results survive: existence of universal tests, conservation of randomness, expression of tests in terms of description complexity, existence of a universal measure, expression of mutual information as "deficiency of independence". • The negative of the new randomness test is shown to be a generalization of complexity in continuous spaces; we show that the addition theorem survives.The paper's main contribution is introducing an appropriate framework for studying these questions and related ones (like statistics for a general family of distributions).
String theory and noncommutative geometry

We extend earlier ideas about the appearance of noncommutative geometry in string theory with a nonzero B-field. We identify a limit in which the entire string dynamics is described by a minimally coupled (supersymmetric) gauge theory on a noncommutative space, and discuss the corrections away from this limit. Our analysis leads us to an equivalence between ordinary gauge fields and noncommutative gauge fields, which is realized by a change of variables that can be described explicitly. This change of variables is checked by comparing the ordinary Dirac-Born-Infeld theory with its noncommutative counterpart. We obtain a new perspective on noncommutative gauge theory on a torus, its T-duality, and Morita equivalence. We also discuss the D0/D4 system, the relation to M-theory in DLCQ, and a possible noncommutative version of the six-dimensional (2,0) theory.
Observer dependence of the quasi-local energy and momentum in Schwarzschild space–time

The observer dependence of the quasi-local energy (QLE) and momentum in the Schwarzschild geometry is illustrated. Using the Brown–York prescription, the QLE for families of non-geodesic and geodesic observers penetrating the event horizon is obtained. An explicit shell-building process is presented and the binding energy is computed in terms of the QLE measured by a static observer field at a radius outside the horizon radius. The QLE for a radially geodesic observer field freely falling from infinity is shown to vanish. Finally, a simple relation for the dynamics of the quasi-local momentum density for a geodesic observer field is noted.
Facial reanimation with microneurovascular free flaps.

Numerous options are available for rehabilitation of chronic facial nerve paralysis, ranging from simple slings to complex procedures such as microneurovascular tissue transfer. Microneurovascular muscle transfer is generally indicated: 1) if the patient desires dynamic facial reanimation, particularly restoration of involuntary emotional facial expressions; 2) in the absence of distal facial nerve fibers or motor endplate fucntion; 3) with an associated large soft tissue defect in the cheek; and 4) when other dynamic reanimation procedures have not been successful. The most commonly used free flaps for facial reanimation are gracilis, latissimus dorsi and inferior rectus abdominus muscle. When successfully performed free flaps yield excellent functional and aesthetic results in facial reanimation.
Brain stem norepinephrine: Behavioural and biochemical differentiation of responses to footshock in rats

Publisher Summary This chapter describes the behavioral and biochemical differentiation of responses to footshock in rats. Norepinephrine (NE) turnover and metabolism in the brain stem of male Long-Evans rats subjected to electric footshock either with or without another rat are studied. Turnover of brain stem norepinephrine was estimated over the one hour period after Shock, and Fighting rats were removed from the shock chamber. In contrast to the lack of change in fighting rats observed immediately following shock presentation, norepinephrine turnover over the subsequent hour was increased substantially. Conversely, 3H-norepinephrine turnover in brain stem of Shock rats, which increased during the shock period itself, was significantly slower than both Control and fighting group norepinephrine turnover. These results clearly differentiate the two groups exposed to electric footshock, whether on a biochemical, or a behavioral basis, and suggest that brain stem norepinephrine containing neurons participate actively in the behavioral responses evoked by electric footshock.
Monomeric Titanium(IV) Azides as a New Route to Titanium Nitride

The reaction of Ti(NMe(2))(4) with 2 equiv of Me(3)SiN(3) in toluene solution affords a dark red polymeric material of composition [Ti(NMe(2))(2)(N(3))(2)](n) (1). If the reaction is carried out in pyridine (py) solution, dark red, crystalline [Ti(NMe(2))(2)(N(3))(2)(py)(2)] (2) is formed. Analogous reactions of Ti(NMe(2))(4) with 2 or 1 equiv of Me(3)SiN(3) in the presence of 1 equiv of bipyridyl (bipy) in toluene solution afford brown crystals of [Ti(NMe(2))(2)(N(3))(2)(bipy)] (3) and dark red crystals of [Ti(NMe(2))(3)(N(3))(bipy)] (4), respectively. Crystallographic data for 2: orthorhombic, C222(1), a = 7.120(1) A, b = 15.899(3) A, c = 16.946(4) A, V = 1918.3(6) A(3), rho = 1.310 g/cm(3), Z = 4. Crystallographic data for 3: monoclinic, I2/a, a = 7.358(2) A, b = 16.808(4) A, c = 14.837(6) A, beta = 95.40(2) degrees, V = 1826.8(1) A(3), rho = 1.368 g/cm(3), Z = 4. Crystallographic data for 4: monoclinic, P2(1)/c, a = 15.682(2) A, b = 8.814(1) A, c = 15.128(1) A, beta = 108.39(1) degrees, V = 1984.2(4) A(3), rho = 1.267 g/cm(3), Z = 4. Compounds 1 and 2 deposit thin films of titanium nitride (TiN) on silica and/or nickel substrates in the temperature range 300-400 degrees C. The TiN films deposited from precursor 2 are superior to those deposited from 1.
Aminimides: III antimicrobial effect of various hexadecyl and quaternary derivatives

Aminimides, a new class of surfactants, have been screened for in vitro antimicrobial activity. Greatest activity against gram (+) and yeast organisms is achieved when a chain length of C16 is reached. This generalization is true whether or not the chain length is joined to the imide or amine group. The type of functional group associated with the surfactant is less important than chain length. Gram (-) organisms do not fit this generalization, since shorter (<C16) rather than longer chain derivatives are more active. The importance of surfactant chain length to biodegrad-ability is discussed.
A Humanistic Technology

"Humanistically viewed, technology is not an end in itself but a means to an end, the end being determined by man." So says Admiral Rickover in this speech which he gave at George town University's Symposium on Cybernetics and Society, November, 1964.
Molecular engineering of mechanophore activity for stress-responsive polymeric materials.

Force reactive functional groups, or mechanophores, have emerged as the basis of a potential strategy for sensing and countering stress-induced material failure. The general utility of this strategy is limited, however, because the levels of mechanophore activation in the bulk are typically low and observed only under large, typically irreversible strains. Strategies that enhance activation are therefore quite useful. Molecular-level design principles by which to engineer enhanced mechanophore activity are reviewed, with an emphasis on quantitative structure–activity studies determined for a family of gem-dihalocyclopropane mechanophores.
Shape estimation in computer tomography from minimal data

In computerized tomography, line integrals of the absorptivity are used to reconstruct the object. In some applications only the locations, sizes, and shapes of internal opacities or near-opacities are needed. For these applications it is unnecessary to reconstruct an image by convolution backprojection [O(N3)] or by direct Fourier methods [O(N2 log N)]. We propose an algorithm suitable for this problem that requires only O(N) operations (N is of the order of the number of views). We analyze and demonstrate the high performance of the algorithm but show that the performance of the algorithm depends strongly on an appropriate choice of system parameters. These parameters, the number of views Nθ, and the detector spacing Δs are shown to be linked, and a choice of Δs strongly constrains the choice of Nθ. We show how an optimum Nθ can be determined for a fixed Δs, including practical values of Δs. A series of experiments that reinforce the theory is simulated on a computer.
A Panel Unit Root Test with Good Power in Small Samples

We propose a new pooled panel unit root test allowing for serial and contemporaneous correlation. The test combines Elliott et al. (1996) local-to-unity transformation with a pooled panel ADF test, and accounts for contemporaneous correlation by estimating the residual covariance matrix. The critical values are bootstrapped and Monte Carlo simulations demonstrate enhanced performances, especially when the series are highly persistent and the panel cross-sectional and time series dimensions are relatively small. An application of the test to the real exchange rate convergence for the post Bretton–Woods period leads to strong and reliable rejections of the unit root.
Cage Breaking Threshold in DLPD of C60

Thin film patterns of desired shape or configuration made of about 15 µm - lines were directly written from a disk of C60 by employing a new laser technique called direct laser patterned deposition (DLPD). DLPD is an ambient technique, needing no special environment or material preparation. Since the ablation and deposition are very localized and deposition and patterning are done in one step this is a very cost efficient process. An energy density threshold was found. Above this density resistance of DLPD films dropped sharply indicating that the C60 cage was broken at least in part of the film.
The effect of strand configuration on the tensile properties of quadrupled tendon grafts

Abstract Purpose: To compare selected biomechanical properties of 4 different quadrupled tendon graft preparations applicable for anterior cruciate ligament reconstruction. Type of Study: Biomechanical investigation in a cadaver model. Methods: Graft strands were arranged in parallel, braided, bolo-plait, and twist configurations. Elongation of the graft was monitored during loading with an infrared optical measurement system, which measured the 3-dimensional position of twelve spherical reflective markers mounted within the camera field. Permanent elongation, stiffness, and ultimate strength of each graft configuration were determined. Results: Permanent graft strain after the first incremental loading cycle was 7.2% in braid, 6.6% in twist, 6.5% in bolo-plait, and 3.3% in parallel constructs ( P P =.0012). Braid and bolo-plait grafts were less stiff than twist or parallel grafts ( P P =.171). Conclusions: Variation in graft configuration from the conventional, parallel strand pattern lead to increased viscoelasticity and permanent elongation of grafts with repetitive loading. This deficit is expected to cause increased laxity of the reconstructed knee. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 2 (February), 2002: pp 194–200
Neurobiological applications of small molecule screening

2.2.1. High-Throughput Screening in vitro 1778 2.2.2. Cell-Based Screening Methods 1779 2.2.3. Tissue-Explant-Based Screens 1780 2.2.4. Organismal Model Systems 1780 2.3. Assay Detection Methods 1781 2.3.1. Spectroscopic Methods 1781 2.3.2. High-Content Screening 1781 3. Target Validation 1782 3.1. Affinity Chromatography 1782 3.2. Protein and Small Molecule Microarrays 1782 3.3. Classical Genetic Screens 1783 3.4. Transcription and Proteomic Profiling 1783 3.5. RNA Interference 1783 4. Concluding Remarks 1783 5. Acknowledgments 1783 6. References 1783
Cooperation and signaling with uncertain social preferences

This paper investigates behavior in finitely repeated simultaneous and sequential-move prisoner’s dilemma games when there is one-sided incomplete information and signaling about players’ concerns for fairness, specifically, their preferences regarding “inequity aversion.” In this environment, we show that only a pooling equilibrium can be sustained, in which a player type who is unconcerned about fairness initially cooperates in order to disguise himself as a player type who is concerned about fairness. This disguising strategy induces the uninformed player to cooperate in all periods of the repeated game, including the final period, at which point the player type who is unconcerned about fairness takes the opportunity to defect, i.e., he “backstabs” the uninformed player. Despite such last-minute defection, our results show that the introduction of incomplete information can actually result in a Pareto improvement under certain conditions. We connect the predictions of this “backstabbing” equilibrium with the frequently observed decline in cooperative behavior in the final period of finitely repeated experimental games.
Advances in transmission x-ray optics☆

Abstract Recent developments in X-ray optics are reviewed. Specific advances in coded aperture imaging, zone plate lens fabrication, time and space resolved spectroscopy and CCD X-ray detection are discussed.
Flow-Birefringence and Stress

IN a recent communication1, Dr. A. S. Lodge proposed: (a) to equate the extinction angle χ in flow-birefringence with the direction of the principal tensile stress, and (b) that the degree of birefringence Dn is proportional to the magnitude of the difference of the principal tensile and compressive stresses ΔP. For plane simple shear, ΔP X sin 2x = 2τ or tan 2x = 2τ/(Σx–Σy), where τ is the measured shear stress, Σx –Σy the difference in ‘normal stresses’, both of which can be derived by various methods, for example, using Mohr's circle2.
Obstruction set isolation for the gate matrix layout problem

Abstract Gate matrix layout is a well-known NP -complete problem that arises at the heart of a number of VLSI layout styles. Despite its apparent general intractability, it has recently been shown that it can be solved in O(n2) time whenever the number of tracks is fixed. Curiously, the proof of this is nonconstructive, based on finite but unknown obstruction sets. What then are such sets, and what is their underlying structure? The main result we report in this paper is a proof that the obstruction set for three tracks contains exactly 110 elements. We also describe a number of methods for obstruction identification that extend to any number of tracks.
Pseudorandomness and Average-Case Complexity Via Uniform Reductions

Impagliazzo and Wigderson (1998) gave the first construction of pseudorandom generators from a uniform complexity assumption on EXP (namely EXP ≠ BPP). Unlike results in the nonuniform setting, their result does not provide a continuous trade-off between worst-case hardness and pseudorandomness, nor does it explicitly establish an average-case hardness result. In this paper:
Imitation dynamics in the repeated Prisoners’ Dilemma: an exploratory example

Abstract This paper investigates a deterministic evolutionary process governing the adoption of strategies for playing the Repeated Prisoners’ Dilemma (RPD). Agents playing unsuccessful strategies attempt to imitate the strategies of successful agents. Because agents’ strategies are unobservable, they must be inferred from a memory of pairwise play and a knowledge of the strategy space. As a result, winning strategies can be confused with other, inferior strategies, and this imperfect imitation can enhance the growth (or slow the decline) of under-performing strategies. In contrast to results obtained under payoff-monotonic dynamics such as the replicator dynamic or an analysis of Neutrally Stable Strategies (NSS), cooperation is eliminated in the long run; agents’ inability to observe the strategies of successful players can fundamentally change the evolutionary dynamics.
Carbon Nanotube Terahertz Polarizer

We describe a film of highly aligned single-walled carbon nanotubes that acts as an excellent terahertz linear polarizer. There is virtually no attenuation (strong absorption) when the terahertz polarization is perpendicular (parallel) to the nanotube axis. From the data, the reduced linear dichrosim was calculated to be 3, corresponding to a nematic order parameter of 1, which demonstrates nearly perfect alignment as well as intrinsically anisotropic terahertz response of single-walled carbon nanotubes in the film.
The Characteristic Treatment of Black Holes

The characteristic initial value problem has been successfully implemented as a robust computational algorithm (the PITT NULL CODE) to evolve 4-dimensional vacuum spacetimes. It has been applied to the calculation of gravitational waveforms emitted by black holes and to the event horizon structure in the merger of black holes. The characteristic code also has potential application to the binary black hole problem via Cauchy-characteristic matching. Because the event horizon is itself a characteristic hypersurface, it can be analyzed by characteristic techniques as a stand-alone object. We have developed an analytic conformal model of null hypersurfaces which gives new insight into the intrinsic geometry of the pairof-pants horizon found in the numerical simulation of the head-on collision of black holes and into the initially toroidal horizon found in the simulation of a collapsing, rotating cluster. Most studies of black hole formation and merger have been restricted to axisymmetry. However, axisymmetric horizons, like the Schwarzschild horizon, are non-generic. When applied to a non-axisymmetric horizon, the characteristic approach reveals substantially new features. In particular, coalescing black holes generically go through a toroidal phase before they become spherical. The conformal structure of the event horizon supplies part of the data for a simulation of the exterior space-time. This provides a new way to calculate the post-merger waveforms from a binary black hole inspiral. §1. Null cone evolution A longterm project 1) to develop the pioneering work of Bondi 2) and Penrose 3) into a computational algorithm for the characteristic initial value problem has recently culminated in a highly accurate,efficient and robust code — the PITT NULL CODE. 4) Because the evolution proceeds on a space-time foliation by null cones which are generated by the characteristic rays of the theory,this approach offers several advantages for numerical work. I will describe here the fruits of these investigations relevant to black hole physics. In null cone coordinates,Einstein’s equations reduce to propagation equations along the radial light rays,which can be integrated in hierarchical order for one variable at a time. This leads to a highly efficient characteristic marching algorithm. There is one complex evolution variable which describes the free degrees of freedom of the gravitational field and four auxiliary variables. A compactified grid,based upon Penrose’s conformal description of null infinity,removes the necessity of an artificial outgoing radiation condition and makes possible a rigorous description of geometrical quantities such as the Bondi mass and news function. The news function supplies both the true waveform and polarization of the gravitational radiation incident on a distant antenna. Furthermore the grid domain is exactly the region in which waves propagate,which is ideally efficient for the purpose of radiation studies. Since each
Neighborhoods to Nations via Social Interactions

Abstract The paper examines decisions by individuals and firms in the presence of social interactions and then turns to cities as the units of analysis. The city-based analysis shows the critical role of intercity trade and its impact on urban sectoral and functional specialization. The paper also examines long-run economic growth in economies made up of cities and Zipf's law in that context. The paper synthesizes key aspects of the social interactions literature with Ioannides (2013) as a background, taking off from key concepts, as presented there and drawing attention to key recent contributions by other researchers.
Quantum feedback control: how to use verification theorems and viscosity solutions to find optimal protocols

While feedback control has many applications in quantum systems, finding optimal control protocols for this task is generally challenging. So-called ‘verification theorems’ and ‘viscosity solutions’ provide two useful tools for this purpose: together they give a simple method to check whether any given protocol is optimal, and provide a numerical method for finding optimal protocols. While treatments of verification theorems usually use sophisticated mathematical language, this is not necessary. In this article we give a simple introduction to feedback control in quantum systems, and then describe verification theorems and viscosity solutions in simple language. We also illustrate their use with a concrete example of current interest.
Transfinite element methodology towards a unified thermal/structural analysis

The paper describes computational developments towards thermal/structural modeling and analysis via a generalized common numerical methodology for effectively and efficiently interfacing interdisciplinary areas. The proposed formulations use transform methods in conjunction with finite element developments for each of the heat transfer and structural disciplines, respectively, providing avenues for obtaining the structural response due to thermal effects. An alternative methodology for unified thermal/structural analysis is presented. The potential of the approach is outlined in comparison with conventional schemes and existing practices. Highlights and characteristic features of the approach are described via general formulations and applications to several problems. Results obtained demonstrate excellent agreement in comparison with analytic and/or conventional finite element schemes accurately and efficiently.
Electroluminescent diodes from a single component emitting layer of dendritic macromolecules

Abstract : Electroluminescent devices have been constructed using luminescent dendritic materials as the organic emitting layer. These dendritic macromolecules consisted of triphenylamines as the hole trapping groups, phenylacetylene segments for energy transfer, and 9,10-bis(phenylethynyl)-anthracene as the luminophor. These highly ordered, three-dimensional, covalent structures allow a modular approach to the design and construction of electroluminescent materials. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) indicated that dendrimers of generation greater than 3 formed uniform, crack-free films of thickness 600-1200 A. Incorporation of triphenylamine units as hole trapping groups in dendrimer 2b increased the current density and lowered the turn on voltage as compared with its hydrocarbon analog 1c. Efficient energy transfer from phenylacetylene segments to the anthracene core is demonstrated by spectroscopic studies (absorption, emission, and excitation spectra). In the forward bias, these light emitting diodes (LEDs) radiate dim orange light. jg
Interaction of Nocturnal Low-Level Jets with Urban Geometries as seen in Joint URBAN 2003 Data

Abstract Because accurate modeling of atmospheric flows in urban environments requires sophisticated representation of complex urban geometries, much work has been devoted to treatment of the urban surface. However, the importance of the larger-scale flow impinging upon the urban complex to the flow, transport, and dispersion within it and downwind has received less attention. Building-resolving computational fluid dynamics (CFD) models are commonly employed to investigate interactions between the flow and three-dimensional structures that make up the urban environment; however, such models are typically forced with simplified boundary conditions that fail to include important regional-scale phenomena that can strongly influence the flow within the urban complex and downwind. This paper investigates the interaction of an important and frequently occurring regional-scale phenomenon, the nocturnal low-level jet (LLJ), with urban-scale turbulence and dispersion in Oklahoma City, Oklahoma, using data from the...
Dimension Reduction by Random Hyperplane Tessellations

Given a subset K of the unit Euclidean sphere, we estimate the minimal number m=m(K) of hyperplanes that generate a uniform tessellation of K, in the sense that the fraction of the hyperplanes separating any pair x,y∈K is nearly proportional to the Euclidean distance between x and y. Random hyperplanes prove to be almost ideal for this problem; they achieve the almost optimal bound m=O(w(K)2) where w(K) is the Gaussian mean width of K. Using the map that sends x∈K to the sign vector with respect to the hyperplanes, we conclude that every bounded subset K of $\mathbb{R}^{n}$ embeds into the Hamming cube {−1,1} m with a small distortion in the Gromov–Haussdorff metric. Since for many sets K one has m=m(K)≪n, this yields a new discrete mechanism of dimension reduction for sets in Euclidean spaces.
What is the Value of Scientific Knowledge? An Application to Global Warming Using the PRICE Model

The question that this study addresses is: What is the value of the new knowledge about climate change? If natural and social scientists succeed in improving their understanding, what will be the payoff in terms of improved economic performance? For example, if the uncertainties are resolved in favor of those who argue that global warming will be minimal or beneficial, then this knowledge will allow countries to avoid expensive investments in non-carbon energy technologies or in expensive conservation efforts. On the other hand, if the worst fears prove correct, then the globe can mend its ways early so as to prevent later dislocations, famines, or inundations. To the extent that the investments are expensive or the consequences are grave, early information can be extremely valuable. 15 refs., 8 figs.
KINEMATICS AND STRUCTURE OF THE STARBURST GALAXY NGC 7673

The morphology and kinematics of the luminous blue starburst galaxy NGC 7673 are explored using the WIYN (Wisconsin-Indiana-Yale-NOAO) 3.5 m telescope. Signs of a past kinematic disturbance are detected in the outer galaxy; the most notable feature is a luminous ripple located from the center 1@ of NGC 7673. Subarcsecond imaging in B and R —lters also reveals red dust lanes and blue star clusters that delineate spiral arms in the bright inner disk, and narrowband Ha imaging shows that the luminous star clusters are associated with giant H II regions. The Ha kinematics measured with echelle imaging spectroscopy using the WIYN DensePak —ber array imply that these H II regions are con—ned to a smoothly rotating disk. The velocity dispersion in ionized gas in the disk is p D 24 km s~1, which sets an upper boundary on the dispersion of young stellar populations. Broad emission components with p D 63 km s~1 found in some regions are likely produced by mechanical power supplied by massive, young stars; a violent starburst is occurring in a kinematically calm disk. Although the asymmetric outer features point to a merger or interaction as the starburst trigger, the inner disk structure constrains the strength of the event to the scale of a minor merger or weak interaction that occurred at least an outer disk dynamical timescale in the past. Subject headings: galaxies: individual (NGC 7673) ¨ galaxies: ISM ¨ galaxies: kinematics and dynamicsgalaxies: starburstgalaxies: structure
Hypergraphs and a functional equation of Bouwkamp and de Bruijn

Let Φ(u,v=Σm=0∞Σn=0∞cmnnmvn. Bouwkamp and de Bruijn found that there exists a power series Ψ(u,v) satisfying the equation Ψ(tz,z)=log(Σk=0∞rk/k! exp(kΦ(kz,z))). We show that this result can be interpreted combinatorially using hypergraphs. We also explain some facts about φ(u,O) and Ψ(u,0).Shown by Bouwkamp and de Bruijn. by using hypertrees,and we use Lagrange inversion to count hypertress by number of vertices and number of edges of a specified size.
Derivation of coarse-grained potentials via multistate iterative Boltzmann inversion

In this work, an extension is proposed to the standard iterative Boltzmann inversion (IBI) method used to derive coarse-grained potentials. It is shown that the inclusion of target data from multiple states yields a less state-dependent potential, and is thus better suited to simulate systems over a range of thermodynamic states than the standard IBI method. The inclusion of target data from multiple states forces the algorithm to sample regions of potential phase space that match the radial distribution function at multiple state points, thus producing a derived potential that is more representative of the underlying interactions. It is shown that the algorithm is able to converge to the true potential for a system where the underlying potential is known. It is also shown that potentials derived via the proposed method better predict the behavior of n-alkane chains than those derived via the standard IBI method. Additionally, through the examination of alkane monolayers, it is shown that the relative weight given to each state in the fitting procedure can impact bulk system properties, allowing the potentials to be further tuned in order to match the properties of reference atomistic and/or experimental systems.
Theory of wing rock

A theory is developed for predicting wing rock characteristics. From available data, it can be concluded that wing rock is triggered by flow asymmetries, developed by negative or weakly positive roll damping, and sustained by nonlinear aerodynamic roll damping. A new nonlinear aerodynamic model that includes all essential aerodynamic nonlinearities is developed. The Beecham-Titchener method is applied to obtain approximate analytic solutions for the amplitude and frequency of the limit cycle based on the three degree-of-freedom equations of motion. An iterative scheme is developed to calculate the average aerodynamic derivatives and dynamic characteristics at limit cycle conditions. Good agreement between theoretical and experimental results is obtained.
Synthesis of novel ring-substituted histidines and histamines

Abstract Synthesis of novel 2-cycloalkyl-L-histidines and 2-cycloalkylhistamines via radical alkylation with cycloalkylcarboxylic acids and silver nitrate in the presence of 10% H2SO4 by ammonium persulfate is described. The method is also extended to the synthesis of 1,2-dialkyl-L-histidines and 1,2-dialkylhistamines.
Shock Persistence and Stochastic Trends in Australian Aggregate Output and Consumption

The distinction between transitory and permanent shocks is at the centre of the debate on which class of models is best suited to represent economic variables: stationary models around a deterministic trend, or stationary models around a stochastic trend The debate u here focused on the Australian case. It is found that both aggregate output and consumption are characterized by stochastic trends, but without a transitory component This corresponds to a measure of shock persistence equal to one for both variables. For the specific case of aggregate output, this result may be interpreted as indicating the absence of business cycles
Valuing intangible assets: newark and beyond.

A controversial topic in US courts has been the tax treatment of purchased intangible assets, which affects the market value of many agribusinesses. The Supreme Court ruled in 1993 that intangible assets, such as sales forces, customer lists, patents, etc., were depreciable if there were reasonable methods for determining the economic life and value of those assets. This article outlines and evaluates some alternative procedures for analyzing economic life and value. In addition, the impact of recent changes in applicable tax law is considered, © 1995 John Wiley & Sons, Inc.
Aziridine mediated asymmetric synthesis of α-benzylserine and α-n-butylserine

Abstract Regioselective hydrogenolysis of enantiopure 2-benzyloxyaziridine 2-carboxylates represents a general method for the asymmetric synthesis of α-substituted serines. The aziridines are readily prepared via an aza-Darzens reaction of the enolate of methyl 3-benzyloxy-2-bromopropanoate with an enantiopure sulfinimine (N-sulfinyl imine).
Remyelination in multiple sclerosis

Chronic plaques in central nervous system tissue fixed by in situ perfusion for electron microscopy were examined for evidence of remyelination in 2 patients with multiple sclerosis (MS). Fibers with abnormal central myelin sheaths of several types were found at the margins of most of the plaques studied. The most common of these were: (1) the presence of bare stretches of axon between contiguous internodes, (2) the presence of thin paranodes, (3) internodes which changed markedly in thickness along their length due to premature termination of superficial or deep myelin lamellae that ended as hypertrophic lateral loops, and (4) abnormally thin internodes which were of uniform thickness along their length, which were shorter than normal, and which terminated in the form of normal nodal complexes. The finding of internodes of the last type at the edges of many plaques indicates that remyelination by oligodendrocytes can occur in the adult human CNS and that it is common in some cases of MS, although limited in its extent.
Modeling and Simulation of Hose-Paradrogue Aerial Refueling Systems

A dynamic modeling and simulation analysis of hose-paradrogue aerial refueling systems is presented. A set of governing equations of motion is derived using a finite-segment approach that describes the dynamics of the hose-paradrogue assembly under a prescribed motion of the tanker. The hose is modeled by a series of ball-and-socket-connected rigid links subject to gravitational and aerodynamic loads that account for the effects of tanker wake, steady wind, and atmospheric turbulence. Numerical simulations show a good correlation of the model's steady-state characteristics with previously reported flight-test data. Also investigated are the dynamic characteristics of the paradrogue assembly resulting from atmospheric turbulence and a typical pitch doublet maneuver of the tanker. Finally, the dynamic motion resulting from an in-flight adjustment of the paradrogue drag associated with strut-angle changes is studied.
Mechanisms of lesion formation in high intensity focused ultrasound therapy

The lesions generated by high intensity ultrasound were studied in transparent tissue phantoms premixed with and without ultrasound contrast agents (UCA) at 1.1- and 3.5-MHz acoustic waves. Generation of small bubbles was observed at the very beginning of exposure, whereas cigar-shaped thermal lesions began to form at the focus after a delay. After further heating, boiling occurred and changed the lesion to tadpole-shape, with advancement toward the transducer. Broadband noise was detected in phantoms with UCA initially. UCA also lowered the pressure threshold and enlarged the lesion. Although thermal and cavitation effects are believed to be both important in lesion formation, tadpole-shaped transformation results from boiling activity.
Braided symmetric and exterior algebras

The goal of the paper is to introduce and study symmetric and exterior algebras in certain braided monoidal categories such as the category O for quantum groups. We relate our braided symmetric algebras and braided exterior algebras with their classical counterparts.
Aromatase inhibitor-induced modulation of breast density: Clinical and genetic effects

Change in breast density may predict outcome of women receiving adjuvant hormone therapy for breast cancer. We performed a prospective clinical trial to evaluate the impact of inherited variants in genes involved in oestrogen metabolism and signalling on change in mammographic percent density (MPD) with aromatase inhibitor (AI) therapy. Postmenopausal women with breast cancer who were initiating adjuvant AI therapy were enrolled onto a multicentre, randomised clinical trial of exemestane vs letrozole, designed to identify associations between AI-induced change in MPD and single-nucleotide polymorphisms in candidate genes. Subjects underwent unilateral craniocaudal mammography before and following 24 months of treatment. Of the 503 enrolled subjects, 259 had both paired mammograms at baseline and following 24 months of treatment and evaluable DNA. We observed a statistically significant decrease in mean MPD from 17.1 to 15.1% (P<0.001), more pronounced in women with baseline MPD ⩾20%. No AI-specific difference in change in MPD was identified. No significant associations between change in MPD and inherited genetic variants were observed. Subjects with higher baseline MPD had a greater average decrease in MPD with AI therapy. There does not appear to be a substantial effect of inherited variants in biologically selected candidate genes.
Electroweak baryogenesis using baryon number carrying scalars

Abstract We describe a new mechanism for the generation of the baryon asymmetry of the universe during a first-order electroweak phase transition. The mechanism requires the existence of two (or more) baryon number carrying scalar fields with masses and CP-violating mixing which vary with the Higgs field expectation value. This mechanism can be implemented using squarks in supersymmetric theories or using leptoquarks. Our central observation is that reflection of these scalars from a bubble wall can yield a significant net baryon number flux into the symmetric phase, balanced by a flux of opposite sign into the broken phase. For generic parameter choices, scalars with incident energies in a specific, but not narrow, range yield order one reflection asymmetries (between the probability of reflection of the scalars and of their antiparticles). The interesting energies are those for which there are two propagating scalars in the symmetric phase but only one in the broken phase. Electroweak sphaleron processes drive the baryon number in the symmetric phase toward zero, but do not act in the broken phase. Our estimate of the resulting baryon asymmetry is consistent with cosmological observations for a range of mass parameters and CP-violating phases in a supersymmetric implementation, as long as the bubble walls are not too fast and not too thick.
Poverty, inequality, and populist politics in Iran

Despite nearly three decades of revolutionary government rule, poverty and inequality remain the central issues of political debate in Iran. The unexpected electoral victory of Ahmadinejad, the populist candidate in the 2005 presidential election, has been widely attributed to rising poverty and inequity. Using household survey data, I examine the trends in poverty and inequality for the last three decades and show that this thesis is not grounded in facts. Survey data show that poverty has substantially declined in recent years, and is low by international standards and in comparison with pre-revolution years. This finding is consistent with pro-poor policies of the Islamic government, mainly in provision of basic infrastructure such as electricity, safe drinking water, and health. However, the same policies have not been as effective in reducing inequality, which, after an initial decline following the Revolution, has remained basically constant in the post-Revolution period.
Dynamics of localized Kaluza?Klein black holes in a collapsing universe

The Clayton Antitrust Act of 1914 prohibits corporate mergers that would result in certain highly undesired end states. We study an exact solution of the Einstein equations describing localized, charged Kaluza?Klein black holes in a collapsing de Sitter universe and seek to demonstrate that a similar effect holds, preventing a potentially catastrophic black hole merger. As the collapse proceeds, it is natural to expect that the black hole undergoes a topological transition, wrapping around the shrinking compact dimension to merge with itself and form a black string. However, the putative uniform charged black string end state is singular and such a transition would violate (a reasonable notion of) cosmic censorship. We present analytic and numerical evidence that strongly suggests the absence of such a transition. Based on this evidence, we expect that the Kaluza?Klein black hole horizon stays localized, despite the increasingly constraining size of the compact dimension. On the other hand, the de Sitter horizon does change between spherical and cylindrical topologies in a simple way.
SCIENCE AND HUMAN PROSPECTS.

On facing the duty of preparing the customary Presidential address for this year, I gave some thought to the question of what contribution I could best make. Having been for many years a field geologist and at times even an explorer, I might have gathered up the results of many local studies and generalized them. Being engaged more recently in studying desert physiography and the Pleistocene history of the Western States, I might have chosen one of those subjects—and indeed they are well worth considering. However, in such a fateful year as 1940, it seemed to me that the occasion called for a subject of greater importance and one that has a more direct relation to the welfare of this nation; and so I decided to ask your attention this evening to a subject that has long been one of my chief concerns—namely, education in Science and its . . .
Interpretation of Ultrasound

This content is designed to acquaint the clinician with some of the more common ultrasonographic manifestations of clinical conditions that the otolaryngologist is likely to encounter in a general practice. The clinician requires a thorough knowledge of head and neck anatomy to best interpret the variations from normal structures demonstrated on ultrasound. A knowledge of sonographic artifacts may assist the examiner in properly identifying the process under review. Ultrasonography may be the best imaging study for certain organs. In many instances it is the first clinical study that directs further imaging. By providing the clinician with clues as to the underlying pathology, it allows a more efficient direction in determining which aspiration techniques to use.
Toward a new history and geography of human genes informed by ancient DNA

Genetic information contains a record of the history of our species, and technological advances have transformed our ability to access this record. Many studies have used genome-wide data from populations today to learn about the peopling of the globe and subsequent adaptation to local conditions. Implicit in this research is the assumption that the geographic locations of people today are informative about the geographic locations of their ancestors in the distant past. However, it is now clear that long-range migration, admixture, and population replacement subsequent to the initial out-of-Africa expansion have altered the genetic structure of most of the world's human populations. In light of this we argue that it is time to critically reevaluate current models of the peopling of the globe, as well as the importance of natural selection in determining the geographic distribution of phenotypes. We specifically highlight the transformative potential of ancient DNA. By accessing the genetic make-up of populations living at archaeologically known times and places, ancient DNA makes it possible to directly track migrations and responses to natural selection.
Structural conditions for full MHD equations

In this paper, we investigate the characteristic structure of the full equations of magnetohydrodynamics (MHD) and show that it satisfies the hypotheses of a general variable-multiplicity stability framework introduced by Metivier and Zumbrun, thereby extending to the general case various results obtained by Metivier and Zumbrun for the isentropic equations of MHD.
Neutron-streak- and framing-camera diagnostics for ICF implosions

Abstract Detailed measurements of the time dependence of the neutron flux from the implosion of DT- and /or DD-filled targets are required to better our understanding of intertial confinement fusion (ICF). Past efforts at developing fast neutron detectors have generally suffered from a lack of sensitivity and/or insufficient time resolution. In this paper we report on a new streak-camera diagnostic for directly time-resolving the neutron burnwidth for ICF implosions. The technique uses elastic scattering of the neutrons in CH 2 to convert the neutron signal to a recoil-proton signal, which is proximity coupled to a CsI secondary-electron emitter. The proton-generated, low-energy, secondary electron emission is subsequently recorded with a standard X-ray streak camera. An X-ray signal is recorded on the streak camera simultaneously with the neutron-produced signal and provides an accurate timing fiducial for burn-time measurements. We have recorded usable signals from the implosion of DT-filled targets producing yields of 3×10 10 neutrons, with a target to photocathode distance of 30 cm. The calculated time resolution is better than 20 ps for the 14.1-MeV DT neutrons and 10 ps for the 2.45-MeV DD neutrons. Our technique for recording the neutron flux can also be extended to high-speed framing cameras, currently capable of 35-ps-duration gate times. The framing cameras may be used to record the burnwidth and/or the neutron energy spectrum. Also, time-resolved neutron imaging of the core should be possible for neutron yields 10 12 .
Aza-Piancatelli Rearrangement Initiated by Ring Opening of Donor–Acceptor Cyclopropanes

The development of a new platform to initiate the cascade rearrangement of furans for the formation of functionalized cyclopentenone building blocks is reported. This methodology allows the creation of congested vicinal stereogenic centers with high diastereoselectivity through a 4π-electrocyclization process.
Preparation of unsaturated α,α-dichloro acid chlorides and intramolecular [2 + 2] cycloadditions of the α-chloroketenes reductively generated from them. Effect of double bond geometry on the cycloaddition

Abstract Reduction of unsaturated α,α-dichloracid chlorides with zinc dust in THF at reflux generates an unsaturated α-chloroketene which undergoes an intramolecular [2 + 2] cycloaddition in good yield. This reaction can be used with three carbon tethers to prepare 5-chlorobicyclo[3.2.0]heptan-6-ones and 1-chlorobicyclo[3.1.1]heptan-6-ones but fails with larger tethers. Unsaturated ketenes 18 and 28, with a trans-double bond, react stereospecifically to give bicyclo[3.1.1]heptanones 21 and 29 in good yield. Unsaturated ketene 12, with a cis-double bond, reacts with loss of stereochemistry to give a 2:1 mixture of 19 and 21 in poor yield. The greater reactivity of trans- than cis-double bonds in intramolecular [2 + 2] cycloadditions of ketenes contrasts to intermolecular cycloadditions in which cis-double bonds are more reactive. Adducts 41 and 42 containing both a chlorine and exomethylene group can be prepared readily. Reductive dechlorination of adducts can be achieved with either (n-Bu)3SnH or CrCl2. Ring contraction to give acids 48 and 49 occurs readily on base treatment.