cssi/SciSciGPT-SciSciNet huggingface dataset:
Numerical Representation of Pitching and Nonpitching Airfoils Undergoing Linear Acceleration

A numerical approach is presented for computing unsteady aerodynamic effects on an airfoil that is undergoing independent pitching and/or plunging motion while attached to an accelerating body. The acceleration of the body may be at any angle to the horizontal axis. Grid speed terms are incorporated into a e rst-order e nite volume representation of the unsteady Euler equations, along with the appropriate acceleration terms for the boundary conditions. Unstructured grid methodology is utilized, along with a moving grid algorithm, to model the pitching/plunging of the airfoil within the grid. A NACA 0012 airfoil is considered for all work. Comparisons are made with nonaccelerating numerical and wind-tunnel data to demonstrate the validity of the methodology. Results are then presented for pitching and nonpitching airfoil, accelerated body cases to demonstrate the effects of the linear acceleration on the unsteady aerodynamics of the airfoil. The quantitative effect of the body acceleration on the aerodynamic coefe cients is seen to be a function of the type of motion (pitching/nonpitching ) imposed upon the airfoil.
Narrowing the generation gap between virtual machines and minicomputers

A virtual machine system has been defined by R. Goldberg as "A system ... which ... is a hardware-software duplicate of a real existing machine in which a non-trivial subset of the virtual machine's instructions execute directly on the host machine, ...".
Complex Aldol Reactions for the Construction of Dense Polyol Stereoarrays: Synthesis of the C33−C36 Region of Aflastatin A

Facial selectivity in the addition of boron enolates of α-oxygenated ketones to anti-disposed α,β-bisalkoxy aldehydes is controlled by the aldehyde vicinal diol protecting group. Protection of the diol as an acetonide results in the exclusive formation of the anti-syn-anti stereoarray found in the C33−C36 region of aflastatin A.
Transmission electron microscopy studies of the polycrystalline silicon-SiO2 interface

Abstract A transmission electron microscopy analysis has been made of the wet oxidation of polycrystalline silicon (poly-Si) films heavily doped with phosphorus in which the poly-SiSiO 2 interface has been given primary consideration. Using conventional and cross section transmission electron microscopy two distinct morphologies have been identified. Firstly, there is a region of enhanced oxidation at the poly-Si grain boundaries, with the concurrent formation of a new crystalline phase. Secondly, a significant roughening of the interface occurs, also associated with a crystalline phase. It is postulated that the formation of these features requires an inhomogenous distribution of the phosphorus dopant, which resulted from low temperature processing.
Measurement of electron impact collisional excitation cross sections of Ni to Ga-Like Gold

Abstract We are measuring the cross sections for the 3d → 4f and 3d → 5f excitations in Ni- to Ga-like Au in beam plasmas created in the Livermore electron beam ion trap EBIT-I. The measurements are possible by using the high-resolution broadband coverage of the Goddard Space Flight Center micro-calorimeter. The cross sections are determined from the ratio of the intensity of the collisionally excited lines to the intensity of the radiative recombination lines. The value of the excitation cross section of the 3d 3/2 → 5f 5/2 transition in Au 50+ (Cu-like) is presented and compared to distorted wave calculations.
Topological Hermitian cobordism

Extending our method for investigating Real cobordism (which was recently used by Hill, Hopkins and Ravenel in their solution of the Kervaire invariant 1 problem), we investigate the \(RO(G)\)-graded homotopy groups of a (non-complete) \(\mathbb {Z}/2\times \mathbb {Z}/2\)-equivariant spectrum called topological Hermitian cobordism. The methods of this paper may be useful in computing the homotopy groups of other \(G\)-equivariant spectra where \(G\ne \mathbb {Z}/2\).
Hilbert Transform Generalization of a Classical Random Vibration Integral

Integrals which represent the spectral moments of the stationary response of a linear and time-invariant system under random excitation are considered. It is shown that these integrals can be determined through the solution of linear algebraic equations. These equations are derived by considering differential equations for both the autocorrelation function of the system response and its Hilbert transform. The method can be applied to determine both even-order and odd-order spectral moments. Furthermore, it provides a potent generalization of a classical formula used in control engineering and applied mathematics. The applicability of the derived formula is demonstrated by considering random excitations with, among others, the white noise, “Gaussian,” and Kanai-Tajimi seismic spectra. The results for the classical problem of a randomly excited single-degree-of-freedom oscillator are given in a concise and readily applicable format.
Lefschetz type formulas for dg-categories

We prove an analog of the holomorphic Lefschetz formula for endofunctors of smooth compact dg-categories. We deduce from it a generalization of the Lefschetz formula of Lunts (J Algebra 356:230–256, 2012) that takes the form of a reciprocity law for a pair of commuting endofunctors. As an application, we prove a version of Lefschetz formula proposed by Frenkel and Ngo (Bull Math Sci 1(1):129–199, 2011). Also, we compute explicitly the ingredients of the holomorphic Lefschetz formula for the dg-category of matrix factorizations of an isolated singularity $${\varvec{w}}$$ . We apply this formula to get some restrictions on the Betti numbers of a $${\mathbb Z}/2$$ -equivariant module over $$k[[x_1,\ldots ,x_n]]/({\varvec{w}})$$ in the case when $${\varvec{w}}(-x)={\varvec{w}}(x)$$ .
A conversation between conflict resolution and social movement scholars

There are scholars of conflict resolution and scholars of social movements, and rarely do the twain meet. Continuing an in-person dialogue, three scholars whose work touches both fields consider the lessons each has to contribute to the other. The paper explores power dynamics, activism solidarity, negotiation strategies, and more.
ALGAE AS A SOURCE OF RENEWABLE CHEMICALS: OPPORTUNITIES AND CHALLENGES

Algae are being explored as a sustainable energy feedstock, having potential to reduce dependence on petrofuels and offset greenhouse gas emissions. Economic considerations and principles of green design suggest that if algae-to-fuel technology is to be successful, biofuels must be produced simultaneously with value-added co-products. At present, the algae industry is centered around a limited number of products, such as low-volume/high-value speciality nutrients. New products for medium- and high-volume markets will be needed as biomass production increases in scale. This Perspective highlights non-fuel applications of algal biomass that have received relatively little attention to date but are promising for future development. It is our goal to draw attention to some of the unique opportunities that algae present with respect to biochemical composition as compared to lignocellulosic energy crops.
Incentive Contracts in Two-Sided Moral Hazards with Multiple Agents

Abstract The paper studies a contracting problem in which a principal enters in two-sided moral hazards withNindependent agents. There are no technological or informational linkages among theNagency problems. Despite this independence, optimal incentive schemes essentially eliminate the principal's incentive problem when team size is large enough. Reputation-like effects appear in a static setting through an improved aggregation of information about the actions of the principal. One implication of this result is that it is generally suboptimal to require an agent's compensation to depend only on his own outcome. Another implication is the existence of purely informational economies of scale to increasing team size. Thus, the concentration of otherwise unrelated transactions in a single “firm” creates wealth through a more efficient use of information about the Principal's actions. The paper also shows that extremely simple statistical contracts are approximately optimal in large teams. The outcome of such contracts is observationally indistinguishable from standard principal–agent contracts. This provides a theoretical justification for using standard principal–agent contracts in environments that involve two-sided hazard in a fundamental way.Journal of Economic LiteratureClassification Numbers: D21, D23.
DEPTHS AND COHEN-MACAULAY PROPERTIES OF PATH IDEALS

Given a tree T on n vertices, there is an associated ideal I of R(x1,...,xn) generated by all paths of a fixed length l of T. We show that such an ideal always satisfies the Konig property and classify all trees for which R/I is Cohen-Macaulay. More generally, we show that an ideal I whose generators correspond to any collection of subtrees of T satisfies the Konig property. Since the edge ideal of a simplicial tree has this form, this generalizes a result of Faridi. Moreover, every square-free monomial ideal can be represented (non-uniquely) as a subtree ideal of a graph, so this construction provides a new combinatorial tool for studying square-free monomial ideals. For a special class of trees, namely trees that are themselves a path of length at least l, a precise formula for the depth is given and it is shown that the proof extends to provide a lower bound on the Stanley depth of these ideals. Combining these results gives a new class of ideals for which the Stanley Conjecture holds.
A ‘Building Block’ Approach To Mixed-Colloid Systems Through Electrostatic Self-Organization

We have developed a highly modular electrostatically-mediated approach to colloid-colloid and polymer-colloid networks using ‘building block’ and ‘bricks and mortar’ self-assembly methodologies, respectively. The former approach involved functionalization of one type of nanoparticle building block with a primary amine and a counterpart building block with a carboxylic acid derivative. After combining these two systems, acid-base chemistry followed by immediate charge-pairing resulted in the spontaneous formation of electrostatically-bound mixed-nanoparticle constructs. The shape and size of these ensembles were controlled via variation of particle size and stoichiometries. In the ‘bricks and mortar’ approach, a functionalized polymer is combined with complementary nanoparticles to provide mixed polymer-nanoparticle networked structures. A notable feature is the inherent porosity resulting from the electrostatic assembly. The shape and size of these ensembles were controlled via variation of particle size, stoichiometries and the order in which they were added.
Primitive collections and toric varieties

This paper studies Batyrev’s notion of primitive collection. We use primitive collections to characterize the nef cone of a quasi-projective toric variety whose fan has convex support, a result stated without proof by Batyrev in the smooth projective case. When the fan is non-simplicial, we modify the definition of primitive collection and explain how our definition relates to primitive collections of simplicial subdivisons. The paper ends with an open problem.
CLASSICAL RADIATION OF ACCELERATED ELECTRONS. II. A QUANTUM VIEWPOINT

The known classical radiation spectrum of a high-energy charged particle in a homogeneous magnetic field is rederived. The method applies, and illuminates, an exact (to order $\ensuremath{\alpha}$) expression for the inverse propagation function of a spinless particle in a homogeneous field. An erratum list for paper I is appended.
Characterization of hybrid molding and lithography for SU-8 micro-optical components

SU-8 is a very promising material for micro-optics. It is mechanically robust with high thermal and chemical resistance, has high transmission at visible and near-infrared wavelengths, and has relatively high refractive index after curing. While lithographic processing of SU-8 is relatively common, molding of SU-8 requires different processing parameters due to challenges with solvent removal and cross-linking. Understanding the effects of the molding process on SU-8 is necessary to optimize performance of molded micro-optical components and also to enable fabrication of more complex micro-optics through subsequent lithographic processing of molded structures. We examine properties of SU-8 as it undergoes the molding process. General characterization of SU-8 shrinkage and expansion is presented, and replication of sub-100-nm structures in SU-8 is demonstrated. Solvent content and refractive index as functions of processing parameters are also examined, along with analysis of SU-8's lithographic properties after undergoing the molding process. These characterizations further enable hybrid combinations of micromolding and lithographic processing to fabricate complex 3-D micro-optics and structures that are difficult or impossible to realize using conventional techniques.
Connectedness properties of the space of complete nonnegatively curved planes

We study the space of complete Riemannian metrics of nonnegative curvature on the plane equipped with the $$C^k$$ topology. If $$k$$ is infinite, we show that the space is homeomorphic to the separable Hilbert space. For any $$k$$ we prove that the space cannot be made disconnected by removing a finite dimensional subset. A similar result holds for the associated moduli space. The proof combines properties of subharmonic functions with results of infinite dimensional topology and dimension theory. A key step is a characterization of the conformal factors that make the standard Euclidean metric on the plane into a complete metric of nonnegative sectional curvature.
Local Economic Conditions and Wage Labor Decisions of Farm and Rural Nonfarm Couples

Effects of geographical differences in local economic conditions on wage labor demand and wage labor participation decisions of rural couples are examined for Current Population Survey households 1978–82. Wage premiums are shown to exist for localities anticipating labor demand growth, higher unemployment rates, larger share of employment in services, and higher costs of living. These effects are stronger for males than females. Effects of local economic conditions on the probability of wage work are consistent with expected market wage and reservation wage effects, and for farm households the probability of wage work increases when expected farm output prices decline or the wage increases.
Impact of FERC 661-A and IEEE 1547 on photovoltaic inverter design

Photovoltaic (PV) inverters may be subject to different standards and interconnection requirements, depending on their size and interconnection point. PV plants connected at transmission voltage levels may be expected to ride through faults and other disturbances, as expressed in FERC Order 661-A for wind power plants. Islanding detection is not necessary, because customers are not directly served from these plants. On the other hand, PV units connected to distribution feeders are expected to trip automatically during voltage and frequency excursions, as expressed in IEEE Std. 1547. Distribution-connected PV inverters have islanding detection that is designed to meet UL 1741. These conflicting requirements may appear as “wind vs. solar” or “transmission vs. distribution” viewpoints. The impacts on utility-scale PV inverter design and specification are discussed.
Dense analytic subspaces in fractal L 2 -spaces

We show that for certain self-similar measures μ with support in the interval 0≤x≤1, the analytic functions {ei2πnx:n=0,1,2, …} contain an orthonormal basis inL2 (μ). Moreover, we identify subsetsP ⊂ ℕ0 = {0,1,2,...} such that the functions {en:n ∈ P} form an orthonormal basis forL2 (μ). We also give a higher-dimensional affine construction leading to self-similar measures μ with support in ℝν, obtained from a given expansivev-by-v matrix and a finite set of translation vectors. We show that the correspondingL2 (μ) has an orthonormal basis of exponentialsei2πλ·x, indexed by vectors λ in ℝν, provided certain geometric conditions (involving the Ruelle transfer operator) hold for the affine system.
Frequency of spurious “intermediate resonances” in randomly generated cross sections

Abstract A program to generate cross sections with parameters chosen in a random fashion from preset distribution showed the existence of spurious “intermediate structures”. Calculations based on the model used and scanning of the cross section showed that in a sample of 25 Γcn there is 30% chance of finding a resonance 6 Γcn wide with σpeak = 1.4σaverage. Widths alone, therefore, are not reliable signatures of the real intermediate structures.
Response time in man-computer conversational transactions

The literature concerning man-computer transactions abounds in controversy about the limits of "system response time" to a user's command or inquiry at a terminal. Two major semantic issues prohibit resolving this controversy. One issue centers around the question of "Response time to what?" The implication is that different human purposes and actions will have different acceptable or useful response times.
Drug dealers' rational choices on which customers to rip-off.

Abstract Background Drug dealers are infamous for overcharging customers and handing over less than owed. One reason rip-offs frequently occur is blackmarket participants have limited access to formal means of dispute resolution and, as such, are attractive prey. Yet drug dealers do not cheat every customer. Though this is implicitly understood in the literature, sparse theoretical attention has been given to which customers are ripped-off and why. Methods To address that lacuna, this paper uses the rationality perspective to analyze qualitative data obtained in interviews with 25 unincarcerated drug sellers operating in disadvantaged neighborhoods of St. Louis, Missouri. Results We find that dealers typically rip-off six types of customers: persons who are strangers, first-time or irregular customers; do not have sufficient money on hand to make a purchase; are uninformed about going market rates; are deemed unlikely to retaliate; are offensive; or are addicted to drugs. Dealers target these groups due to perceiving them as unlikely to be repeat business; not worth the hassle of doing business with; unlikely to realize they are being ripped-off; in the wrong and thus deserving of payback; and, unwilling to retaliate or take their money elsewhere. Conclusion Our findings are discussed in relation to their practical implications, including the importance of giving blackmarket participants greater access to law, and how customers may prevent being ripped-off.
Invariance Properties of Thematic Factorizations of Matrix Functions

Abstract We study the problem of invariance of indices of thematic factorizations. Such factorizations were introduced by V. V. Peller and N. J. Young (1994, J. Funct. Anal.120, 300–343) for studying superoptimal approximation by bounded analytic matrix functions. As shown by Peller and Young, the indices may depend on the choice of a thematic factorization. We introduce the notion of a monotone thematic factorization. The main result shows that under natural assumptions a matrix function that admits a thematic factorization also admits a monotone thematic factorization and the indices of a monotone thematic factorization are uniquely determined by the matrix function itself. We obtain similar results for so-called partial thematic factorizations.
Nearly Circular Connections of Elastic Half Spaces

In this paper we solve the elasticity problem of two elastic half spaces that are joined together over a region that does not differ much from a circle, i.e., the problem of an external planar crack leaving a nearly circular uncracked connection. The method we use is based on the perturbation technique developed by Rice (1985) for solving the elastic field of a crack whose front deviates slightly from some reference geometry. Quantities such as crack opening displacement and stress intensity factor are derived in detail to the first order of accuracy in the deviation of the shape of the connection from a circle. In addition, some results such as the crack face weight functions and Green's functions for a perfectly circular connection are also discussed under various boundary conditions at infinity. The formulae derived are used to study the configurational stability problem for quasistatic growth of an external circular crack. The results, derived when the crack front is perturbed from circular in a harmonic waveform and is subjected to axisymmetric loading, suggest that a perturbation of wavenumber higher than one is configurationally stable under all boundary conditions at infinity. The perturbation with wavenumber equal to one, which corresponds to a translational shift of the geometric center of the circular connection, turns out to be configurationally stable if any rotation in the remote field is suppressed and configurationally unstable if there is no such restraint.
The impact of the AIDS pandemic on health services in Africa: evidence from demographic and health surveys.

We document the impact of the AIDS crisis on non-AIDS-related health services in 14 sub-Saharan African countries. Using multiple waves of Demographic and Health Surveys (DHS) for each country, we examine antenatal care, birth deliveries, and rates of immunization for children born between 1988 and 2005. We find deterioration in nearly all these dimensions of health care over this period. The most recent DHS survey for each country collected data on HIV prevalence, which allows us to examine the association between HIV burden and health care. We find that erosion of health services is the largest in regions that have developed the highest rates of HIV. Regions of countries that have light AIDS burdens have witnessed small or no declines in health care, using the measures noted above, while those regions shouldering the heaviest burdens have seen the largest erosion in non-HIV-related health services for pregnant women and children. Using semiparametric techniques, we can date the beginning of the divergence in the use of antenatal care and in children’s immunizations between high- and low-HIV regions to the mid-1990s.
Diffraction of coherent light with sinusoidal amplitude by a thin-slit grid

Abstract We report on the experimental findings of a thin-slit grid diffraction of a coherent light beam with sinusoidal amplitude. We produce diffraction of a field with sinusoidal amplitude by placing a thin-slit grid at the center of the dark fringes of an interference pattern resulting from laser light passing through a dual pinhole. The experimental results show good agreement with diffraction calculations of a thin-slit grid placed at the center of the dark fringes produced by two coherent beams that intersect at small angle. The results are applied to wire-grid diffraction in the Afshar experiment.
What did we learn from gamma-ray burst 080319B?

The optical and gamma-ray observations of GRB 080319B allow us to provide a broad-brush picture for this remarkable burst. The data indicate that the prompt optical and gamma-ray photons were possibly produced at the same location but by different radiation processes: synchrotron and synchrotron self-Compton, respectively (but we note that this interpretation of the gamma-ray data faces some difficulties). We find that the burst prompt optical emission was produced at a distance of 10 16.3 cm by an ultrarelativistic source moving at Lorentz factor of ∼500. A straightforward inference is that about 10 times more energy must have been radiated at tens of GeV than that released at 1 MeV. Assuming that the GRB outflow was baryonic and the gamma-ray source was shock-heated plasma, the collimation-corrected kinetic energy of the jet powering GRB 080319B was larger than 10 52.3 erg. The decay of the early afterglow optical emission (up to 1 ks) is too fast to be attributed to the reverse-shock crossing the GRB ejecta but is consistent with the expectations for the ‘large-angle’ emission released during the burst. The pure power-law decay of the optical afterglow flux from 1 ks to 10 d is most naturally identified with the (synchrotron) emission from the shock propagating into a wind-like medium. However, the X-ray afterglow requires a departure from the standard blast-wave model.
Nongray radiating flow about smooth symmetric bodies

Nongray absorption and radiation cooling on smooth symmetric blunt bodies included in modified Maslen flow field method for radiation and large blowing
The Effects of Unanticipated Macroeconomic News on Debt Markets

We examine the effects of unanticipated macroeconomic news on two interest rate futures using intraday data. The surprises are identified on the basis of their potential effects on debt markets (positive or negative) and by their size (large, medium, or small). The results show distinct ex-post return patterns associated with different categories of news surprises. For example, large surprises have the strongest immediate effects whereas negative surprises have the longest persisting effects. Tests that examine the separate effects of each announcement suggest that debt responses vary with the size and potential effect of the news surprise in each announcement.
Localized temporal profile of surveillance video

Surveillance videos are recorded pervasively and their retrieval currently still relies on human operators. As an intermediate representation, this work develops a new temporal profile of video to convey accurate temporal information in the video while keeping certain spatial characteristics of targets of interest for recognition. The profile is obtained at critical positions where major target flow appears. We set a sampling line crossing the motion direction to profile passing targets in the temporal domain. In order to add spatial information to the temporal profile to certain extent, we integrate multiple profiles from a set of lines with blending method to reflect the target motion direction and position in the temporal profile. Different from mosaicing/montage methods for video synopsis in spatial domain, our temporal profile has no limit on the time length, and the created profile significantly reduces the data size for brief indexing and fast search of video.
Hypokalemia promotes late phase 3 early afterdepolarization and recurrent ventricular fibrillation during isoproterenol infusion in Langendorff perfused rabbit ventricles

Background Hypokalemia and sympathetic activation are commonly associated with electrical storm (ES) in normal and diseased hearts. The mechanisms remain unclear. Objective The purpose of this study was to test the hypothesis that late phase 3 early afterdepolarization (EAD) induced by I KATP activation underlies the mechanisms of ES during isoproterenol infusion and hypokalemia. Methods Intracellular calcium (Ca i ) and membrane voltage were optically mapped in 32 Langendorff-perfused normal rabbit hearts. Results Repeated episodes of electrically induced ventricular fibrillation (VF) at baseline did not result in spontaneous VF (SVF). During isoproterenol infusion, SVF occurred in 1 of 15 hearts (7%) studied in normal extracellular potassium ([K + ] o, 4.5 mmol/L), 3 of 8 hearts (38%) in 2.0 mmol/L [K + ] o , 9 of 10 hearts (90%) in 1.5 mmol/L [K + ] o , and 7 of 7 hearts (100%) in 1.0 mmol/L [K + ] o ( P i transient duration (Ca i TD) and heterogeneously shortened action potential duration (APD) after defibrillation, leading to late phase 3 EAD and SVF. I KATP blocker (glibenclamide, 5 μmol/L) reversed the post-defibrillation APD shortening and suppressed recurrent SVF in all hearts studied despite no evidence of ischemia. Nifedipine reliably prevented recurrent VF when given before, but not after, the development of VF. I Kr blocker (E-4031) and small-conductance calcium-activated potassium channel blocker (apamin) failed to prevent recurrent SVF. Conclusion Beta-adrenergic stimulation and concomitant hypokalemia could cause nonischemic activation of I KATP, heterogeneous APD shortening, and prolongation of Ca i TD to provoke late phase 3 EAD, triggered activity, and recurrent SVF. I KATP inhibition may be useful in managing ES during resistant hypokalemia.
Energetics and Stability of Translating Media with an Arbitrarily Varying Length

The linear dynamics of a class of translating media with an arbitrarily varying length is investigated. The tension in the media arising from their longitudinal accelerations is incorporated. The dynamic stability of the continuous media relative to the inertial and moving coordinate systems is studied from the energy standpoint. The exact expressions for the rates of change of energies of media are derived and interpreted from both control volume and system viewpoints. The stability analyses relative to the inertial and moving coordinate systems result in the same predictions. Examples including a robotic arm through a prismatic joint and an elevator cable in a high-rise building illustrate the analysis. In particular, the results explain an inherent unstable shortening cable behavior encountered in elevator industry.
Successful completion of the femtosecond slicing upgrade at the ALS

An upgraded femtosecond slicing facility has been commissioned successfully at the Advanced Light Source. In contrast to the original facility at the ALS which pioneered the concept, the new beamline uses an undulator (the first in-vacuum undulator at the ALS) as the radiator producing the user photon beam. To spatially separate the femtosecond slices in the radiator, a local vertical dispersion bump produced with 12 skew quadrupoles is used. The facility was successfully commissioned during the last 1.5 years and is now used in routine operation.
Bifurcations in a Mathieu equation with cubic nonlinearities: Part II

Abstract In a previous paper [Chaos Solitons Fract. 14(2) (2002) 173], the authors investigated the dynamics of the equation: d 2 x d t 2 +(δ+ϵ cos t)x+ϵ Ax 3 +Bx 2 d x d t +Cx d x d t 2 +D d x d t 3 =0 We used the method of averaging in the neighborhood of the 2:1 resonance in the limit of small forcing and small nonlinearity. We found that a degenerate bifurcation point occurs in the resulting slow flow and some of the bifurcations near this point were looked at. In this work we present additional results concerning the bifurcations around this point using analytic techniques and AUTO. An analytic approximation for a heteroclinic bifurcation curve is obtained. Additional results on the bifurcations of periodic orbits in the slow flow are also presented.
Twisted quandle homology theory and cocycle knot invariants

The quandle homology theory is generalized to the case when the coecient groups admit the structure of Alexander quandles, by includ- ing an action of the innite cyclic group in the boundary operator. Theories of Alexander extensions of quandles in relation to low dimensional cocycles are developed in parallel to group extension theories for group cocycles. Ex- plicit formulas for cocycles corresponding to extensions are given, and used to prove non-triviality of cohomology groups for some quandles. The cor- responding generalization of the quandle cocycle knot invariants is given, by using the Alexander numbering of regions in the denition of state- sums. The invariants are used to derive information on twisted cohomology groups. AMS Classication 57N27, 57N99; 57M25, 57Q45, 57T99
Conditional Sparse Coding and Grouped Multivariate Regression

We study the problem of multivariate regression where the data are naturally grouped, and a regression matrix is to be estimated for each group. We propose an approach in which a dictionary of low rank parameter matrices is estimated across groups, and a sparse linear combination of the dictionary elements is estimated to form a model within each group. We refer to the method as conditional sparse coding since it is a coding procedure for the response vectors Y conditioned on the covariate vectors X. This approach captures the shared information across the groups while adapting to the structure within each group. It exploits the same intuition behind sparse coding that has been successfully developed in computer vision and computational neuroscience. We propose an algorithm for conditional sparse coding, analyze its theoretical properties in terms of predictive accuracy, and present the results of simulation and brain imaging experiments that compare the new technique to reduced rank regression.
When Worlds Collide: Quantum Probability from Observer Selection?

In Everett's many worlds interpretation, quantum measurements are considered to be decoherence events. If so, then inexact decoherence may allow large worlds to mangle the memory of observers in small worlds, creating a cutoff in observable world size. Smaller world are mangled and so not observed. If this cutoff is much closer to the median measure size than to the median world size, the distribution of outcomes seen in unmangled worlds follows the Born rule. Thus deviations from exact decoherence can allow the Born rule to be derived via world counting, with a finite number of worlds and no new fundamental physics.
The Effects of Revenue Changes on NCAA Athletic Departments’ Expenditures

This study uses a panel of National Collegiate Athletic Association (NCAA) Division I athletic department revenue and expenditure data from 225 public colleges and universities to empirically investigate the behavior of athletic departments over the period 2006-2011. Three empirical relationships were explored: (a) how changes in total revenue affect disaggregated expenditure categories, (b) how disaggregated revenue streams influence total expenditures, and (c) whether changes in revenue categories change the size of the athletic department’s subsidy. The results show that additional athletic revenue increases expenditures for coaches 7.5 times more than direct expenditures for student-athletes, a ratio that increases for schools in power conferences. For every US$1 increase in ticket sale revenue, total expenditures can rise by US$0.83 and reduce a school’s athletic subsidy by US$0.19.
Ultrafast electro-absorption at the transition between classical and quantum response

We have made the first observation of induced absorption extending /spl sim/1 eV below the band edge in semiconductors strongly driven by intense ultrafast mid-infrared laser pulses, which we attribute to the dynamical Franz-Keldysh effect.
A New Reynolds Stress Algebraic Equation Model

A general turbulent constitutive relation is directly applied to propose a new Reynolds stress algebraic equation model. In the development of this model, the constraints based on rapid distortion theory and realizability (i.e. the positivity of the normal Reynolds stresses and the Schwarz' inequality between turbulent velocity correlations) are imposed. Model coefficients are calibrated using well-studied basic flows such as homogeneous shear flow and the surface flow in the inertial sublayer. The performance of this model is then tested in complex turbulent flows including the separated flow over a backward-facing step and the flow in a confined jet. The calculation results are encouraging and point to the success of the present model in modeling turbulent flows with complex geometries.
Supporting Independence in Adolescents on the Autism Spectrum

The development of independent behavior is a critical, challenging process for all youth as they pass through the high school environment into adulthood. Although most high school students gain skills related to independence, the independent behaviors of their peers with autism spectrum disorder (ASD) plateau and decline. These skill deficits and resulting poor post-secondary outcomes for students with ASD highlight the great need for programming in this area. This article begins by defining independence and the influence of independence on post-secondary outcomes, and explores the factors that contribute to the difficulties in independence for individuals with ASD. Then, a review of school-wide positive behavior support and focused evidence-based practices (EBPs) related to independence is presented. Recommendations are made for practitioners and caregivers implementing interventions intended to support student independence, and recommendations for future research and practice are offered.
Variable Angle of Incidence Spectroscopic Ellipsometric Study of Semiconductor Multilayer Structures

The sensitivity of spectroscopic ellipsometry data to multilayer model parameters is shown to be a strong function of the angle of incidence. A quantitative study for a GaAs-AlxGa1-xAs-GaAs structure shows that maximum sensitivity to layer thicknesses and ternary composition occurs near the wavelength-dependent principal angle. These results are verified by experimental measurements on two MBE-grown samples. Moderately high doping levels in the ternary layers are also found to strongly affect the data at photon energies below the ternary bandgap. Null ellipsometry measurements at only two wavelengths are sufficient to determine layer thicknesses.
Pro-poor growth : A primer

These days it seems that almost everyone in the development community is talking about "pro-poor growth." What exactly is it, and how can we measure it? Is ordinary economic growth always "pro-poor growth" or is that some special kind of growth? And if it is something special, what makes it happen? Ravallion first reviews alternative approaches to defining and measuring "pro-poor growth." He then analyzes evidence on whether growth is pro-poor, what factors make it more pro-poor (including the role played by both initial inequality and changing inequality), and whether the factors that make the distribution of the gains from growth pro-poor come at a cost to growth. The author identifies some priorities for future research. This paper - a product of the Poverty Team, Development Research Group - is part of a larger effort in the group to contribute to knowledge about the link between economic growth and poverty reduction.
Efficient computational tool for ramjet combustor research

A multigrid-base d calculation procedure is presented for the efficient solution of the time-averaged equations of a turbulent, elliptic-reacting flow. The equations are solved on a nonorthogonal curvilinear coordinate system. The physical models currently incorporated are a two-equation A-e turbulence model, a four-step chemical kinetics mechanism, and a Lagrangian particle-tracking procedure applicable to dilute sprays. Demonstration calculations are presented to illustrate the performance of the calculation procedure for a ramjet dump combustor configuration.
The Hippo-YAP signaling pathway and contact inhibition of growth

The Hippo-YAP pathway mediates the control of cell proliferation by contact inhibition as well as other attributes of the physical state of cells in tissues. Several mechanisms sense the spatial and physical organization of cells, and function through distinct upstream modules to stimulate Hippo-YAP signaling: adherens junction or cadherin–catenin complexes, epithelial polarity and tight junction complexes, the FAT-Dachsous morphogen pathway, as well as cell shape, actomyosin or mechanotransduction. Soluble extracellular factors also regulate Hippo pathway signaling, often inhibiting its activity. Indeed, the Hippo pathway mediates a reciprocal relationship between contact inhibition and mitogenic signaling. As a result, cells at the edges of a colony, a wound in a tissue or a tumor are more sensitive to ambient levels of growth factors and more likely to proliferate, migrate or differentiate through a YAP and/or TAZ-dependent process. Thus, the Hippo-YAP pathway senses and responds to the physical organization of cells in tissues and coordinates these physical cues with classic growth-factor-mediated signaling pathways. This Commentary is focused on the biological significance of Hippo-YAP signaling and how upstream regulatory modules of the pathway interact to produce biological outcomes.
Practical Verifiable Encryption and Decryption of Discrete Logarithms

This paper addresses the problem of designing practical protocols for proving properties about encrypted data. To this end, it presents a variant of the new public key encryption of Cramer and Shoup based on Paillier’s decision composite residuosity assumption, along with efficient protocols for verifiable encryption and decryption of discrete logarithms (and more generally, of representations with respect to multiple bases). This is the first verifiable encryption system that provides chosen ciphertext security and avoids inefficient cut-and-choose proofs. The presented protocols have numerous applications, including key escrow, optimistic fair exchange, publicly verifiable secret and signature sharing, universally composable commitments, group signatures, and confirmer signatures.
The general circulation of the atmosphere: A numerical experiment

A long-period numerical forecast is made with a two-level quasi-geostrophic model, starting with an atmosphere in relative rest. Both friction and non-adiabatic effects are included in the equations, the latter as a linear function of latitude. Principal empirical elements in the experiment are the intensity of the heating, the value of the vertical stability, and the type of frictional dissipation. The flow patterns which develop are quite realistic, including a jet and zonal surface westerlies in middle latitudes, and the growth of a large disturbance. The associated energy transformations are investigated, and demonstrate the important role of the disturbance in the development of the zonal currents. The meridional circulation is also studied, together with its contribution to the zonal momentum budgets of the lower and upper halves of the atmosphere. Truncation errors eventually put an end to the forecast by producing a large fictitious increase in energy.
Preparation of High-Tc Superconducting Oxides by the Amorphous Citrate Process

The high-Tc superconducting oxide Yba2Cu3O7–y has been prepared by the amorphous citrate process. A citrate-nitrate solution was prepared at room temperature and dehydrated at around 80°C to yield a solid precursor material. The precursor was fired to high temperature to form the desired compound. The decomposition mechanism was studied with thermogravimetric analysis and X-ray diffraction. Intermediate products were formed during the decomposition reactions. Nearly phase-pure Yba2Cu3O7-y powders were obtained by firing the precursor in air to 900°Cfor2 h. Sintered samples were typically over 90% dense and exhibited good superconducting properties.
Oxygen‐atom transfer chemistry of α‐AZO hydroperoxides: Effect of competitive intramolecular hydrogen bonding and α‐methyl substitution

1-(Phenylazo)-1-(2-pyridyl)ethyl hydroperoxide, 1, 1-(phenylazo)-1-(2-furyl)ethyl hydroperoxide, 2, phenylazo(2-furyl)methyl hydroperoxide, 3, 1-(phenylazo)-1-(4-anisyl)ethyl hydroperoxide, 4, were synthesized in moderate yield by autoxidation of the phenylhydrazones in benzene. The ionic oxidation of benzyl methyl sulfide in benzene by 1-4 yielded the sulfoxide and the metastable α-azo hydroxides in essentially quantitative yield. The reaction was of the first order in α-azo hydroperoxide and sulfide, respectively. The relative reactivity series found was: 1(1.0) <4(1.4) < phenylazo(4-anisyl)methyl hydroperoxide 5 (2·9) <2 (3·8) < 3 (9·6). α-Methyl substitution was found to slow the rate of oxygen-atom trasfer by a factor of 2 to 2.5. The low relative reactivity of 1 was opposite that expected based on electronic effects. Competitive intramolecular hydrogen bonding of the hydroperoxy proton to the pyridyl nitrogen in 1 accounted for the observed result.
Electron–Phonon Interactions in Polyacene Organic Transistors

We present a simple model for the electron-phonon interactions between the energy subbands in polyacene field-effect transistors and the vibrations of the crystal. We introduce a generalized SuSchrieffer-Heeger model, arguing that the strongest electron-phonon interactions in these systems originate from the dependence of inter-molecule hopping amplitudes on collective molecular motion. We compute the electron-phonon spectral function α 2 F(ω) as a function of two-dimensional hole density and the coupling strength constant. Our results are in agreement with the sharp onset of superconductivity near half-filling discovered in recent experiments by Schon et al. [1] and predict an increase of T c with pressure. We further speculate on the implications that the observation of the quantum Hall effect in these systems has on the effective band mass in the low carrier density regime.
Spacing and capacity evaluations for different AHS concepts

The inter-vehicle separation during vehicle following is one of the most critical parameters of the automated highway system (AHS), as it affects both safety and highway capacity. The trade-off between capacity and safety gives rise to a variety of different AHS concepts and architectures. In this study we consider a family of AHS operational concepts. For each concept we calculate the minimum inter-vehicle spacing that could be used for collision-free vehicle following, under different road conditions. For architectures involving platoons we also use the alternative constraint of bounded energy collisions to calculate the minimum spacing that can be applied if we allowed collisions at a limited relative velocity in case of emergency stopping. The minimum spacing is used to calculate the maximum possible capacity that could be achieved for each operational concept.
From nanodevices to nanosystems: The N3XT information technology

Next-generation information technologies will process unprecedented amounts of loosely-structured data, including streaming video and audio, natural languages, real-time sensor readings, and contextual environments. These newly available data far exceed the processing capacity of existing computing architectures.
Five decades of mechanistic and exploratory organic photochemistry

This exposition summarizes a personal perspective on past and current develop- ments in organic photochemistry. It comprises three portions. The first section describes the beginnings of our photochemical studies and how it was possible to relate photochemical re- activity to excited-state electronic structures. The second selectively relates some of the re- actions and concepts developed in the intermediate years. Finally, the third portion describes our recent research.