cssi/SciSciGPT-SciSciNet huggingface dataset:
Environment, corporate entrepreneurship, and financial performance: A taxonomic approach

Abstract This study examined the association between a firm's external environment, corporate entrepreneurship, and financial performance. The study emphasized three propositions: (1) perceived—rather than objective-characteristics of the environment significantly influenced entrepreneurship activities; (2) a multidimensional definition of a firm's environment was essential to unravel the interplay between the environment, orporate entrepreneurship activities, and financial performance; and (3) a taxonomic approach had the advantage of accounting for the interrelationships among the dimensions of the environment in classifying firms. Using data from 102 companies in six4-digit industrial classification codes (SIC),cluster analysis was used to distinguish four environmental settings: “dynamic growth,” “hostile and rivalrous but technologically rich,” “hospitable, product-driven growth,” and “static and impoverished” environments. These four environments varied in their characteristics. The four empirically derived environment clusters were then used to examine variations in corporate entrepreneurship—operationalized as corporate innovation and venturing, and corporate renewal activities. The first dimension—corporate innovation and venturing—had four components: new business creation, new product introduction, percent of revenue from new products, and technological entrepreneurship. The renewal dimension had three components: mission reformulation, reorganization, and system-wide change. The data were used to test six hypotheses: 1. H1: In dynamic or growth environments, companies will emphasize new business creation and innovation. 2. H2: Environmental hostility is positively associated with the redefinition of business through venturing activities. 3. H3: Hospitable business environments are positively associated with business venturing and renewal activities. 4. H4: Static environments are inversely associated with corporate venturing and renewal activities. 5. H5: Corporate entrepreneurship activities are positively associated with company financial performance. 6. H6: Corporate entrepreneurship activities emphasised in HI through H4 will be significantly and positively associated with company financial performance in their respective environmental clusters. The results provided general support for the six hypotheses. They showed that: (1) each environmental cluster had a distinct combination of activities relating to corporate innovation and venturing, and renewal; (2) corporate entrepreneurship activities varied in their associations with measures of company growth and profitability; and (3) the associations between corporate entrepreneurship and company financial performance varied among the four environment clusters. The results from this study can help executives in selecting specific entrepreneurial activities that match the demands of success in their business environment to improve their company's performance.
The Medicinal Applications of Imidazolium Carbene Metal Complexes

Ofele and Wanzlick reported the synthesis of the first N-heterocyclic carbene (NHC) metal complexes in 1968.1,2 The isolation of the first free carbene by Arduengo in 1991 set the scene for an ever-growing interest and advancement in the field of N-heterocyclic carbene chemistry.3 Shortly thereafter, the use of these ligands in organometallic chemistry, particularly in catalysis dramatically increased.4,5 N-heterocyclic carbenes are neutral 2-electron donors, with an ability to bond to both hard and soft metals making them more versatile ligands than phosphines.6 As an added advantage, not only are NHCs easier to synthesize and functionalize than phosphines but they also form a stronger bond to metals and therefore form more stable metal complexes than metal phosphine complexes.7,8 The N-heterocyclic carbene ligands interact with metal centers primarily through strong σ-donation and to a lesser degree through π-backdonation (Figure 1).9,10 Figure 1 Orbital diagram of NHC bonding to metal center. Ghosh and coworkers11,12,13,14,15,16 as well as others17,18,19 took special interest in the exceptional stability of several metal-NHC complexes and conducted in depth analyses in order to gain better insights into the structure and bonding. In particular, the metal-ligand donor-acceptor interactions were inspected using the charge decomposition analysis (CDA). CDA is a tool used to quantitatively estimate the degree of NHC → metal σ-donation, designated by d, and NHC ← metal π-back donation, designated by b.20,21 Thus a higher d/b ratio emphasizes the ability of NHC to function as an effective σ-donor, whereas a lower d/b ratio highlights the greater NHC ← metal π-back donation. Interestingly, in the studies conducted by Ghosh, greater NHC ← metal π-back donation was observed in Pd-NHC complexes exhibiting lower d/b ratios ranging between 2.59 – 3.9913,14 and Au-NHC complexes with d/b ratios ranging between 5.23 – 5.8815,16 as compared to the Ag-NHC complexes with d/b ratios ranging between 7.8 – 12.6811,12,16. This observation could attest to why silver-NHC complexes are particularly better transmetallating agents. The newly emerging interest in the medicinal applications of stable metal NHCs led us to examine the few accounts available in the literature dealing with this area of research. This review will discuss in detail the medicinal applications of various transition metal-NHC complexes including silver, gold, rhodium, ruthenium, and palladium. The antimicrobial, antitumor, and resistance properties, along with proposed mechanisms of action to suppress the bacterial growth or proliferation of tumor cells will be discussed.
Self-organized critical earthquake model with moving boundary

A globally driven self-organized critical model of earthquakes with conservative dynamics has been studied. An open but moving boundary condition has been used so that the origin (epicenter) of every avalanche (earthquake) is at the center of the boundary. As a result, all avalanches grow in equivalent conditions and the avalanche size distribution obeys excellent finite size scaling. Though the recurrence time distribution of the time series of avalanche sizes obeys well both the scaling forms recently observed in analysis of the real data of earthquakes, it is found that the scaling function decays only exponentially in contrast to a generalized gamma distribution observed in the real data analysis. The non-conservative version of the model shows periodicity even with open boundary.
Efficient Inverse Auger Recombination at Threshold in CdSe Nanocrystals

We apply the semiempirical nonlocal pseudopotential method to the investigation of prospects for direct carrier multiplication (DCM) in neutral and negatively charged CdSe nanocrystals. In this process, known in the bulk as impact ionization, a highly excited carrier transfers, upon relaxation to the band edge, its excess energy Δ to a valence electron, promoting it across the band gap and thus creating two excitons from one. For excess energies just a few meV above the energy gap Eg (the DCM threshold), we find the following: (i) DCM is much more efficient in quantum dots than in bulk materials, with rates of the order of 1010 s-1. In conventional bulk solids, comparable rates are obtained only for excess energies about 1 eV above Eg. (ii) Unlike the case in the bulk, in both neutral and charged nanocrystals the DCM rate is not an increasing function of the excess energy but oscillates as Δ moves in and out of resonance with the energy of the discrete spectrum of these 0D systems, (iii) The main contribution to the DCM rates is found to come from the dot surface, as in the case of Auger multiexciton recombination rates, (iv) Direct radiative recombination of excited electron-hole pairs and phonon-assisted decay are slower than DCM, but (v) the rate of Auger cooling (where the relaxation energy of an excited electron is used to excite a hole into deeper levels) can be of the same order of magnitude as that of the DCM process. Furthermore, for excess energies well above the DCM threshold, the presence of an energy gap within the hole manifold considerably slows DCM compared to Auger cooling (AC), which is not affected by it. Achieving competitive DCM processes will, therefore, require the suppression of Auger cooling, for example, by removing the hole from the dot or by trapping it at the surface.
THE FIRST TWO HOST GALAXIES OF X-RAY FLASHES: XRF 011030 AND XRF 020427

Given the paucity of empirical constraints, the nature of the newly recognized phenomena called X-ray flashes (XRFs) has been an open question. However, with the recent detections of radio and X-ray afterglow it is finally possible to study the large- and small-scale environments of XRFs. We present Chandra, Hubble Space Telescope (HST), and Keck observations of the fields of XRFs 011030 and 020427. Astrometric comparisons of the X-ray transient positions and the HST images reveal the XRFs to be associated with faint blue galaxies. Photometric evidence of these putative hosts suggests that these two XRFs originated from redshifts less than z ~ 3.5, and thus cannot be due to GRBs at very high redshifts. In both host-burst offsets and host properties, these XRFs could have been drawn from distributions similar to those measured of gamma-ray bursts (GRBs). We conclude with a discussion of the implications of this XRF-GRB host connection for the possible progenitors of XRFs.
An uncertainty principle for cyclic groups of prime order

Let $G$ be a finite abelian group, and let $f: G \to \C$ be a complex function on $G$. The uncertainty principle asserts that the support $\supp(f) := \{x \in G: f(x) \neq 0\}$ is related to the support of the Fourier transform $\hat f: G \to \C$ by the formula $$ |\supp(f)| |\supp(\hat f)| \geq |G|$$ where $|X|$ denotes the cardinality of $X$. In this note we show that when $G$ is the cyclic group $\Z/p\Z$ of prime order $p$, then we may improve this to $$ |\supp(f)| + |\supp(\hat f)| \geq p+1$$ and show that this is absolutely sharp. As one consequence, we see that a sparse polynomial in $\Z/p\Z$ consisting of $k+1$ monomials can have at most $k$ zeroes. Another consequence is a short proof of the well-known Cauchy-Davenport inequality.
TWIST LATTICES AND THE JONES–KAUFFMAN POLYNOMIAL FOR LONG VIRTUAL KNOTS

In this paper, we investigate twist sequences for Kauffman finite-type invariants and Goussarov–Polyak–Viro finite-type invariants. It is shown that one obtains a Kauffman or GPV type of degree ≤ n if and only if an invariant is a polynomial of degree ≤ n on every twist lattice of the right form. The main result of this paper is an application of this technique to the coefficients of the Jones–Kauffman polynomial. It is shown that the Kauffman finite-type invariants obtained from these coefficients are not GPV finite-type invariants of any degree by explicitly showing they can never be polynomials. This generalizes a result of Kauffman [8], where it is known for degree k = 2.
A transformation system for deductive database modules with perfect model semantics

Abstract We present a transformation system for deductive database (DDB) modules. We show that it preserves several data-dependency properties of a DDB and is correct for the “perfect model” semantics of DDBs. Perfect models are not directly amenable to logical reasoning since logically equivalent DDBs may have different perfect models. We develop an approach which involves using a condition on data dependencies in DDBs (stratification compatibility) to pass from a logical equivalence to equivalence under perfect model semantics. This is readily applicable to the transformation system.
Numerical Algorithms for Mapping Boundaries of Manipulator Workspaces

Numerical algorithms for mapping boundaries of manipulator workspaces are developed and illustrated. Analytical criteria for boundaries of workspaces for both manipulators having the same number of input and output coordinates and redundantly controlled manipulators with a larger number of inputs than outputs are well known, but reliable numerical methods for mapping them have not been presented. In this paper, a numerical method is first developed for finding an initial point on the boundary. From this point, a continuation method that accounts for simple and multiple bifurcation of one-dimensional solution curves is developed. Second order Taylor expansions are derived for finding tangents to solution curves at simple bifurcation points of continuation equations and for characterizing barriers to control of manipulators. A recently developed method for tangent calculation at multiple bifurcation points is employed. A planar redundantly controlled serial manipulator is analyzed, determining both the exterior boundary of the accessible output set and interior curves that represent local impediments to motion control. Using these methods, more complex planar and spatial Stewart platform manipulators are analyzed in a companion paper.
Technical, organizational and political dynamics of the International Space Station program

Abstract This paper analyzes the dynamics of cooperation of the International Space Station (ISS) program from its inception in 1981 to the final Framework Agreements for cooperation concluded in 1998. These dynamics include technical and organizational arrangements, and policy preferences. Dynamics related to technical arrangements deal with technological and scientific resources, the former governed through mechanisms for control of technology transfer, the latter regulated through intellectual property rights provisions. The dynamics linked to organizational arrangements concern authority patterns—characterized by national and international responses—and bilateral and multilaterial decision-making patterns. The dynamics of policy preferences encompass functional and symbolic dimensions. Functional issues are structured through legal and political regimes that govern the ISS program. The symbolic dimension, which includes prestige, legitimacy, influence and international accountability, frames the nature of the cooperation realized for the ISS program. ISS cooperation has evolved through three stages: (1) coordination, where collaboration is engendered through institutional (International Coordinating Working Group) and ad hoc cooperative relationships (groups of scientists and engineers sharing information); (2) augmentation, which equates with technological enhancements of a national project that involve primarily bilateral arrangements; (3) interdependence, which deals with cooperation in enabling and critical path technologies that are arranged both bilaterally and multilaterally.
Experimental Evidence for a Dynamical Non-locality Induced Effect in Quantum Interference Using Weak Values

The quantum theoretical concepts of modular momentum and dynamical non-locality, which were introduced four decades ago, have recently been used to explain single particle quantum interference phenomena. Although the non-local exchange of modular momentum associated with such phenomena cannot be directly observed, it has been suggested that effects induced by this exchange can be measured experimentally using weak measurements of pre- and post-selected ensembles of particles. This paper reports on such an optical experiment that yielded measured weak values that were consistent with the theoretical prediction of an effect induced by a non-local exchange of modular momentum.
RECOVERING SINGULAR INTEGRALS FROM HAAR SHIFTS

We recover one-dimensional Calderon-Zygmund convolution operators with sufficiently smooth kernels by means of a properly chosen averaging of certain dyadic shift operators. As a corollary, a sharp A 2 inequality for these Calderon-Zygmund operators is derived from a corresponding inequality for dyadic shift operators.
An efficient synthesis of 1-phenyl-1-piperidino-trans-4-methylcyclohexane: Unanticipated total stereoselectivity in the catalytic hydrogenation of an olefin

Abstract A superior synthesis of the title compound, 1-phenyl-1-piperidino-trans-4-methylcyclohexane, is reported. The key step, the catalytic hydrogenation of 1-phenyl-1-piperidino-4-methylenecyclohexane hydrochloride, proceeds with unusual stereospecificity via addition of hydrogen trans to the axial phenyl substituent.
Extremal behavior of divisibility functions

In this short article, we study the extremal behavior \({{\mathrm{F}}}_\Gamma (n)\) of divisibility functions \({{\mathrm{D}}}_\Gamma \) introduced by the first author for finitely generated groups \(\Gamma \). These functions aim at quantifying residual finiteness and bounds give a measurement of the complexity in verifying a word is non-trivial. We show that finitely generated subgroups of \({{\mathrm{GL}}}(m,K)\) for an infinite field \(K\) have at most polynomial growth for the function \({{\mathrm{F}}}_\Gamma (n)\). Consequently, we obtain a dichotomy for the growth rate of \(\log {{\mathrm{F}}}_\Gamma (n)\) for finitely generated subgroups of \({{\mathrm{GL}}}(n,\mathbf {C})\). We also show that if \({{\mathrm{F}}}_\Gamma (n) \preceq \log \log n\), then \(\Gamma \) is finite. In contrast, when \(\Gamma \) contains an element of infinite order, \(\log n \preceq {{\mathrm{F}}}_\Gamma (n)\). We end with a brief discussion of some geometric motivation for this work.
Layered Ternary and Quaternary Metal Chalcogenides

The syntheses, crystal structures, and physical properties of some recently discovered layered ternary and quaternary chalcogenides are reviewed. One component of these systems is an alkali metal or thallium; another is a d-, f-, or p- block metal.
Asymptotics of Markov Kernels and the Tail Chain

Abstract : An asymptotic model for extreme behavior of certain Markov chains is the tail chain''. Generally taking the form of a multiplicative random walk, it is useful in deriving extremal characteristics such as point process limits. We place this model in a more general context, formulated in terms of extreme value theory for transition kernels, and extend it by formalizing the distinction between extreme and non-extreme states. We make the link between the update function and transition kernel forms considered in previous work, and we show that the tail chain model leads to a multivariate regular variation property of the finite-dimensional distributions under assumptions on the marginal tails alone.
Tandem bis-aza-Michael addition reaction of amines in aqueous medium promoted by polystyrenesulfonic acid

Abstract An efficient and environmentally benign tandem bis-aza-Michael addition of amines catalyzed by polystyrenesulfonic acid (PSSA) is described. This operationally simple high yielding microwave assisted synthetic protocol proceeded in water in the absence of any organic solvent.
Discount rates, social judgments, individuals’ risk preferences, and uncertainty

The choice of the proper discount rate is important in the analysis of projects whose costs and benefits extend into the future, a particularly striking feature of policies directed at climate change. Much of the literature, including prominent work by Arrow et al. (1996), Stern (2007, 2008), and Dasgupta (2008), employs a reduced-form approach that conflates social value judgments and individuals’ risk preferences, the latter raising an empirical question about choices under uncertainty rather than a matter for ethical reflection. This article offers a simple, explicit decomposition that clarifies the distinction, reveals unappreciated difficulties with the reduced-form approach, and relates them to the literature. In addition, it explores how significant uncertainty about future consumption, another central factor in climate policy assessment, raises further complications regarding the relationship between social judgments and individuals’ risk preferences.
D-meson mixing in broken SU(3)

Abstract A fit of amplitudes to the experimental branching ratios to two mesons is used to construct a new estimate of neutral D mixing which includes SU (3) breaking. The result is dominated by the experimental uncertainties. This suggests that the charm sector may not be as sensitive to new physics as previously thought and that long-distance calculations may not be useful.
Determination of the boiling enhancement mechanism caused by surfactant addition to water

In the present investigation, boiling heat transfer coefficients are measured for an electrically heated 390-μm-dia, platinum wire immersed in saturated water, and in water mixed with three different concentrations of sodium dodecyl sulfate (an anionic surfactant). The addition of a surfactant to water is known to enhance boiling heat transfer. A recently developed photographic/laser-Doppler anemometry measurement technique is used to quantify the vapor volumetric flow rate departing from the wire during the boiling process. The volumetric flow rate data are used to calculate the latent heat and, indirectly, the convection heat transfer mechanisms that constitute the nucleate boiling heat flux. Comparisons are made to determine how the heat transfer mechanisms are affected by the surfactant addition, and thus, which mechanism promotes boiling enhancement. The present data are also compared with similar data taken for a 75-μm-dia wire immersed in saturated FC-72 (a highly wetting liquid) to provide increased insight into the nature of the boiling heat transfer mechanisms.
The Physician and the Sexual Revolution.

IN the field of sex education physicians have been lagging. They have not been exercising their influence to the fullest degree. Yet sexual and marital maladjustment is a major health problem. The development of healthy sex attitudes must begin with sound education in childhood. The object of this paper is to consider, from the standpoint of emotional health, the current sexual revolution, with its emphasis on freedom and permissiveness for the adolescent. At a recent meeting on planned parenthood an eminent physician is reported to have said, "Parents are becoming more sophisticated. They know, for example, that their son or . . .
Regularity and long-time behavior of nonlocal heat flows

This article considers nonlocal heat flows into a singular target space. The problem is the parabolic analogue of a stationary problem that arises as the limit of a singularly perturbed elliptic system. It also provides a gradient flow approach to an optimal eigenvalue partition problem that, in light of the work of Caffarelli and Lin, is equivalent to a constrained harmonic mapping problem. In particular, we show that weak solutions of our heat equation converge as time approaches infinity to stationary solutions of this mapping problem. For these weak solutions, we also prove Lipschitz continuity and regularity of free interfaces, making use of a parabolic Almgren-type monotonicity formula.
Elevated-Temperature Creep Buckling of Thermoplastic-Matrix Fiber Composites under Biaxial Loading:

An analytical study has been conducted to investigate the elevated- temperature creep buckling behavior of thermoplastic-matrix composite laminates sub jected to multiaxial loading. Anisotropic time-temperature dependent viscoelastic consti tutive equations of the composite are constructed first, using the experimental results and the modified Prony series expansion solution. Creep buckling loads and associated creep failure times are determined by a time-dependent bifurcation buckling analysis of the ther moplastic composite laminates under general loading in an elevated-temperature environ ment. Detailed solutions for high-temperature creep buckling and associated failure mode shapes of the AS4/J1 thermoplastic composite laminates with various fiber orientations are obtained. The creep buckling mode shape changes and the accompanying failure loads are studied for three commonly encountered loading modes: (1) pure shear, (2) biaxial compression with any arbitrary stress biaxiality ratios, and (3) combine...
Mouse Primary Uterine Cell Coculture System Revisited: Ovarian Hormones Mimic the Aspects of in Vivo Uterine Cell Proliferation

Previously, the uterine epithelial-stromal coculture system had limited success mimicking in vivo ovarian hormone-dependent cell-specific proliferation. Here, we established a mouse primary uterine coculture system, in which cells collected in pseudopregnancy specifically on d 4 are conducive to supporting hormone-induced cell-specific proliferation. When two cell types are placed in coculture without direct contact via cell culture inserts (nonadjacent), as opposed to with contact (adjacent), epithelial cells exhibit significant proliferation by estradiol-17β (E2), whereas progesterone in combination with E2 caused inhibition of epithelial cell proliferation and a major shift in proliferation from epithelial to stromal cells. Epithelial cell integrity, with respect to E-cadherin expression, persisted in nonadjacent, but not adjacent, conditions. In subsequent studies of nonadjacent cocultures, localization of estrogen receptor (ER)α and progesterone receptor (PR), but not ERβ, appeared to be abundant, presumably indicating that specific ER or PR coregulator expression might be responsible for this difference. Consistently, an agonist of ERα, but not ERβ, was supportive of proliferation, and antagonists of ER or PR totally eliminated cell-specific proliferation by hormones. RT-PCR analyses also revealed that hormone-responsive genes primarily exhibit appropriate regulation. Finally, suppression of immunoglobulin heavy chain binding protein, a critical regulator of ERα signaling, in epithelial and/or stromal cells caused dramatic inhibition of E2-dependent epithelial cell proliferation, suggesting that a molecular perturbation approach is applicable to mimic in vivo uterine control. In conclusion, our established coculture system may serve as a useful alternative model to explore in vivo aspects of cell proliferation via communication between the epithelial and stromal compartments under the direction of ovarian hormones.
Raman spectroscopy of carbon overcoats for magnetic disks

Abstract The magnetic thin film media in disk drives are usually covered with hard protective overcoats. Carbon thin films are often used for this purpose but their properties can vary widely. Tough amorphous carbon films are a subject of great interest but their complete characterization requires a wide range of measurements, many of which are not easily accessible. We have found that Raman spectroscopy can serve as a convenient non-destructive technique for examining the carbon films on magnetic disks. Here we review the use of Raman spectroscopy in view of the extensive work that has been done recently on hard carbon films which have been called by a variety of names: amorphous “diamond-like carbon”, “i-carbon” or “amorphous hydrogenated carbon”.
Gravitation, Electromagnetism and Cosmological Constant in Purely Affine Gravity

The Ferraris-Kijowski purely affine Lagrangian for the electromagnetic field, that has the form of the Maxwell Lagrangian with the metric tensor replaced by the symmetrized Ricci tensor, is dynamically equivalent to the metric Einstein-Maxwell Lagrangian, except the zero-field limit, for which the metric tensor is not well-defined. This feature indicates that, for the Ferraris-Kijowski model to be physical, there must exist a background field that depends on the Ricci tensor. The simplest possibility, supported by recent astronomical observations, is the cosmological constant, generated in the purely affine formulation of gravity by the Eddington Lagrangian. In this paper we combine the electromagnetic field and the cosmological constant in the purely affine formulation. We show that the sum of the two affine (Eddington and Ferraris-Kijowski) Lagrangians is dynamically inequivalent to the sum of the analogous (ΛCDM and Einstein-Maxwell) Lagrangians in the metric-affine/metric formulation. We also show that such a construction is valid, like the affine Einstein-Born-Infeld formulation, only for weak electromagnetic fields, on the order of the magnetic field in outer space of the Solar System. Therefore the purely affine formulation that combines gravity, electromagnetism and cosmological constant cannot be a simple sum of affine terms corresponding separately to these fields. A quite complicated form of the affine equivalent of the metric Einstein-Maxwell-Λ Lagrangian suggests that Nature can be described by a simpler affine Lagrangian, leading to modifications of the Einstein-Maxwell-ΛCDM theory for electromagnetic fields that contribute to the spacetime curvature on the same order as the cosmological constant.
Investigation of laminar dispersion with optical coherence tomography and optical Doppler tomography

As the imaging speed of Optical Coherence Tomography (OCT) and Optical Doppler Tomography (ODT) increases, a new horizon to access dynamical systems with fast transients will be open near future. The objective of this research is to demonstrate its potential to measure simultaneously the structure and velocity information of dynamical systems. Transient two-fluid mixing in microfluidic devices are good examples to display clearly the advantages of ODT over other techniques. Laminar dispersion in a serpentine microchannel with a Y-shape inlet was investigated using OCT and ODT. It was shown that OCT/ODT is not only a visualization method but also a methodology to characterize important physics: streamwise velocity, secondary streamline, sedimentation time scale, shear dispersion. To demonstrate the capability of OCT/ODT, transient mixing was observed and three-dimensional imaging was performed.
Fisher waves in the diffusion-limited coalescence process A + A ⇄ A

Abstract Fisher waves have been studied recently in the specific case of diffusion-limited reversible coalescence, A + A ⇄: A , on the line. An exact analysis of the particles concentration showed that waves propagate from a stable region to an unstable region at constant speed, just as in Fisher's “mean-field” theory; but also that the wave front fails to retain its initial shape and instead it broadens with time. Our present analysis encompasses the full hierarchy of multiple-point density correlation functions, and thus it provides a complete exact description of the same system. We find that as the wave propagates, the particles in the stable phase remain distributed exactly as in their initial (equilibrium) state. On the other hand, the leading particle — the one at the edge of the wave-advances as a biased random walk, rather than simply linearly with time. Thus the shape of the wave remains actually constant, but it is the “noisy” propagation of the wave's edge that causes its apparent broadening.
Highly Enantioselective Copper−Bisoxazoline-Catalyzed Allylic Oxidation of Cyclic Olefins with tert-Butyl p-nitroperbenzoate

Catalytic asymmetric allylic oxidation of cyclic olefins ocurrs for the first time in very high (94−99% ee) enantioselectivity using copper(I) complexes of malonyl derived bisoxazolines and tert-butyl p-nitroperbenzoate giving allyl benzoates in moderate yield. The copper complex, 15 mol %, was used in acetonitrile at −20 °C over an extended period, 5−12 d, with excess olefin together with one equivalent of perester. The S-esters were generated in accord with the model proposed previously for the (S,S)-bisoxazoline ligand. An η2 intermediate was ruled out using low-temperature 13C NMR with the complex in the presence of olefin.
Spectator interactions in soft-collinear effective theory

Abstract Soft-collinear effective theory is generalized to include soft massless quarks in addition to collinear fields. This extension is necessary for the treatment of interactions with the soft spectator quark in a heavy meson. The power counting of the relevant fields and the construction of the effective Lagrangian are discussed at leading order in Λ / m b . Several novel effects occur in the matching of full-theory amplitudes onto effective-theory operators containing soft light quarks, such as the appearance of an intermediate mass scale and large non-localities of operators on scales of order 1/ Λ . Important examples of effective-theory operators with soft light quarks are studied and their renormalization properties explored. The formalism presented here forms the basis for a systematic analysis of factorization and power corrections for any exclusive B -meson decay into light particles.
The trial translator: an automatic programming system for experimental Russian-English machine translation

Grammatical and syntactic rules designed for the production of "smooth" automatic translations between human languages will be called translation algorithms. Because of the rigid constraints imposed by automatic machines, the formulation of translation algorithms involves unprecedented problems of a linguistic nature. Much of the existing literature in the field of machine translation consists of theoretical treatments of these problems, or of appropriately simplified abstractions from these problems. Several specific algorithms for the machine translation of Russian to English have been proposed, but none have been tested on a large scale. These rules are apparently based on the intuition and linguistic backgrounds of the individual writers, sometimes aided by the manual analysis of short text samples. Until very recently the use of automatic machines has been confined to the application of ad-hoc computer programs, tailored to the processing of particular sentences or carefully selected texts.
What determines the stock market's reaction to monetary policy statements?

Abstract We find that information communicated through monetary policy statements has important business cycle dependent implications for stock prices. For example, during periods of economic expansion, stocks tend to respond negatively to announcements of higher rates ahead. In recessions, however, we find a strong positive reaction of stocks to seemingly similar signals of future monetary tightening. We provide evidence that the state dependence in the stock market's response is explained by information about the expected equity premium and future corporate cash flows contained in monetary policy statements. We also show state dependence in the average stock returns on days of scheduled FOMC meetings and in the impact of monetary policy statements on stock and bond return volatility.
Three-dimensional shear-driven boundary-layer flow with streamwise adverse pressure gradient

The effects of adverse pressure gradient on a three-dimensional turbulent boundary layer are studied in an axisymmetric forward-facing step geometry. Velocity measurements made using a three-component laser Doppler velocimeter include mean flow as Reynolds stresses and velocity triple-product correlations. Turbulent Prandtl mixing lengths are extracted from the data, showing the effects of curvature
Synthesis and characterization of A3Na10Sn23 (A = Cs, Rb, K) with a new clathrate-like structure and of the chiral clathrate Rb5Na3Sn25.

Four new compounds Cs17.4(1)Na60.6(1)Sn138 (1), Rb19.1(1)Na58.9(1)Sn138 (2), K21.3(1)Na56.7(1)Sn138 (3), and Rb20Na12Sn100 (4) were synthesized by fusion of the corresponding elements. The structures were determined by single-crystal X-ray diffraction. Compounds 1−3 are isostructural and crystallize in a new structure type (rhombohedral, R3m, Z = 1, a = 12.4567(9) A, c = 51.533(3) A for 1; a = 12.465(1) A, c = 51.085(3) A for 2; a = 12.456(2) A, c = 50.559(4) A for 3). The structure contains layers of fused pentagonal dodecahedra of tin that alternate with layers of isolated tin tetrahedra. It is an intergrowth between the structure of clathrate-II (A24Sn136) with the same layers of pentagonal dodecahedra and the Zintl phase ASn with Sn44- tetrahedra. Compound 4 is a new chiral clathrate (cubic, P4132, Z = 1; a = 16.4127(7) A) with stoichiometry that corresponds to an electronically balanced Zintl phase.
Energetic-Particle Populations and Cosmic-Ray Entry

Abstract : This report constitutes a review of recent progress in the study of charged-particle access, transport, and loss with respect to the earth's magnetosphere. A major objective of studying particle access is to identify the sources of trapped and quasi-trapped radiation. Important progress in this area involves the measurement of comparative ionic abundances in the radiation belts. The historic problem of accounting for cosmic-ray cut-off latitudes as a function of particle energy is being solved by the adoption of increasingly realistic and accurate models of the magnetospheric B field. Progress in the estimation of particle-transport coefficients (mainly diffusion coefficients) involves the measurement of fluctuating electric and magnetic fields on the ground, at balloon altitudes, and in space. The importance of particle interactions with discrete waveforms (as distinguished from broad-banded spectral noise) is increasingly being recognized. For example, the unsteady magnetospheric convection associated with substorms contributes importantly to radial diffusion, whereas cyclotron resonance with chorus elements and other discrete excitations may contribute importantly to pitch-angle diffusion and (thus) to the loss of energetic particles from the magnetosphere. The role of man-made signals such as radio transmissions and power-line harmonics in this latter process remains uncertain and continues to be debated. (Author)
Culture and the Historical Process

This article discusses the importance of accounting for cultural values and beliefs when studying the process of historical economic development. A notion of culture as heuristics or rules of thumb that aid in decision making is described. Because cultural traits evolve based upon relative fitness, historical shocks can have persistent effects if they alter the costs and benefits of different traits. A number of empirical studies confirm that culture is an important mechanism that helps explain why historical shocks can have persistent impacts; these are reviewed here. As an example, I discuss the colonial origins hypothesis (Acemoglu, Johnson, and Robinson 2001), and show that our understanding of the transplantation of European legal and political institutions during the colonial period remains incomplete unless the values and beliefs brought by European settlers are taken into account. It is these cultural beliefs that formed the foundation of the initial institutions that in turn were key for long-term economic development.
Current Status of Simulations

As the title suggests, the purpose of this chapter is to review the current status of numerical simulations of black hole accretion disks. This chapter focuses exclusively on global simulations of the accretion process within a few tens of gravitational radii of the black hole. Most of the simulations discussed are performed using general relativistic magnetohydrodynamic (MHD) schemes, although some mention is made of Newtonian radiation MHD simulations and smoothed particle hydrodynamics. The goal is to convey some of the exciting work that has been going on in the past few years and provide some speculation on future directions.
Deciphering deconfinement in correlations of conserved charges

Diagonal and off-diagonal flavour and conserved charge susceptibilities reveal the prevalent degrees of freedom of heated strongly-interacting matter. Results obtained from lattice simulations are compared with various model estimates in an effort to weed down various possible pictures of a quark–gluon plasma. We argue that the vanishing of the off-diagonal quark flavour susceptibility and its derivatives with respect to chemical potential, at temperatures above 1.5 Tc, can only be understood in a picture of a gas or liquid composed of quasiparticles which carry the same quantum numbers as quarks and antiquarks. A new potential observable, blind to neutral and non-strange particles, is introduced and related via isospin symmetry to the ratio of susceptibilities of baryonic strangeness to strangeness generated in the excited matter created at the Relativistic Heavy Ion Collider.
Superconducting accelerometers for the study of gravitation and gravitational radiation

Abstract Two superconducting accelerometers have been developed as sensors for the gravity wave experiment. Both accelerometers consist of radio frequency resonant circuits whose parameters are modulated by acceleration. The first accelerometer possesses a free floating proofmass and can therefore respond to extremely low level, long period accelerations. It is well suited for measurements and G and G . The second accelerometer, a bound-mass system, has unique design features that make it particularly well suited for sensing the vibrations of a gravity wave detector. The ultimate sensitivities of these two systems, limited by phase noise in the master oscillator that drives them, is 10−17 cm for the free-mass accelerometer and 10−19 cm for the bound-mass accelerometer.
Biorobotic insights into how animals swim

SUMMARY Many animals maneuver superbly underwater using their pectoral appendages. These animals range from sunfish, which have flexible, low aspect ratio fins, to penguins, which have relatively stiff, high aspect ratio wings. Biorobotics is a means of gaining insight into the mechanisms these animals use for maneuvering. In this study, experiments were carried out with models of abstracted penguin wings, and hydrodynamic characteristics – in particular, efficiency – were measured directly. A cross-flow vortex model of the unsteady force mechanism was developed that can compute instantaneous lift and drag forces accurately. This makes use of the steady characteristics of the fin and proposes that cross-flow drag vortices of bluff bodies in steady flow are analogous to dynamic stall vortices and that fin oscillation is a means for keeping the vortices attached to the fin. From what has been reported for sunfish with pectoral fins to our current measurements for single abstracted penguin wings, we infer that the maximum hydrodynamic efficiency has remained largely unchanged. A selection algorithm was used to rapidly find the fin oscillation parameters for optimum efficiency. Finally, we compared the measurements on the penguin-like relatively stiff fins and the reported flow visualization of flexible sunfish pectoral fins. The flexible pectoral fins of station-keeping sunfish exhibit a rich repertoire of capability such as the formation of dynamic stall vortices simultaneously on two leading edges during part of the cycle, changes in projected area in different planes, and the vectoring of jets. However, such fins may not be scalable to larger biorobotic vehicles and relatively stiff fins appear to be better suited instead, albeit with somewhat limited station-keeping ability.
Community-Based Risk Management Arrangements: A Review

Summary Risk and its consequences pose a formidable threat to poverty reduction efforts. This article reviews a plethora of community-based risk management arrangements across the developing world. These types of arrangements are garnering greater interest in light of the growing recognition of the relative prominence of household- or individual-specific idiosyncratic risk as well as the increasing shift towards community-based development funding. The article discusses potential advantages (such as targeting, cost and informational) and disadvantages (such as exclusion and inability to manage correlated risk) of these arrangements, and their implications for the design of community-based social protection programs and policies.
Jet tomography of Au+Au reactions including multi-gluon fluctuations

Abstract Jet tomography is the analysis of the attenuation pattern of high transverse momentum hadrons to determine certain line integral transforms of the density profile of the QCD matter produced in ultra-relativistic nuclear collisions. In this Letter, we calculate the distortion of jet tomography due to multi-gluon fluctuations within the GLV radiative energy loss formalism. We find that fluctuations of the average gluon number, 〈 N g 〉∼3 for RHIC initial conditions, reduce the attenuation of pions by approximately a factor Z ≈0.4–0.5. Therefore the plasma density inferred from jet tomography without fluctuations must be enhanced by a factor 1/ Z ∼2.
Antimatter-gravity couplings, and Lorentz symmetry

Implications of possible CPT and Lorentz violation for antimatter-gravity experiments as well as other antimatter tests are considered in the context of the general field-theory-based framework of the Standard-Model Extension (SME).
A homophonic cipher for computational cryptography

Computational cryptography deals with the storage and processing of sensitive information in computer systems by enciphering. Sensitive information is information that for one reason or another must be protected from being disclosed to individuals without proper authorization. The need for systems to be secure from unauthorized access to sensitive information has been well documented. Cyrptographic techniques appear to be one of the most simple and secure methods of providing this much needed protection.
A new sensitivity analysis for structural optimization of composite rotor blades

This paper presents the mathematical details of the formulation for the sensitivity derivatives for the structural dynamic, aeroelastic stability, and response characteristics of a rotor blade in hover and forward flight. The formulation is denoted by the term semi-analytical approach, because certain derivatives are evaluated by a finite difference scheme. Using this formulation, sensitivity derivatives for structural dynamic and aeroelastic stability characteristics were evaluated for a composite rotor blade. Useful conclusions regarding the relative merits of the semi-analytical approach, when compared to a pure finite difference approach, are obtained. In addition, influence of ply orientation angles on the vibratory hub loads in forward flight is also considered.
Domain walls are diamagnetic

Abstract It is shown that contrary to a recent claim in the literature by Iwazaki [Ferromagnetic Domain Wall and Primeval Magnetic Field, Nishogakusha Univ. report Nisho-96/4 (August 1996), hep-ph/9608448], the domain walls made of scalar field are diamagnetic due to presence of massless fermionic modes on the wall. The diamagnetism vanishes at high temperature. Thus the domain walls could produce no effect on a primordial magnetic field in the early universe.
Piecing the solar neutrino puzzle together at SNO

Abstract We perform an oscillation parameter-independent analysis of solar neutrino flux measurements from which we predict the charged-current rate at SNO relative to Standard Solar Model to be R SNO CC =0.35 +0.16 −0.09 0.46 +0.13 −0.11 for oscillations to active (sterile) neutrinos. By alternately considering the 8 B flux normalization fixed and free, we find that the flux measured by Super-Kamiokande (SK) not being a result of oscillations is strongly disfavored for oscillations to active neutrinos. SNO will determine the best-fit value of the 8 B flux normalization β (equal to the neutral-current rate), without recourse to neutral-current measurements, from the derived relation β=R SNO NC =5.85 R SK −4.85 R SNO CC . Using a simple parameterization of the fraction of high, intermediate, and low energy solar neutrinos starting above resonance, we reproduce the results of global analyses to good accuracy; we find that the LMA solution with a normal mass hierarchy is clearly favored. With β free, our analysis for oscillations to active neutrinos gives R SNO NC = β =1.34±0.34, which corresponds to R SNO CC =0.28±0.07.
The scope and mechanism of rearrangement of 4,6-dialkoxy-2-pyrones☆

Abstract The scope and mechanism of a remarkably facile interconversion between 4,6-dialkoxy-3-alkyl-2-pyrones and their corresponding 5-alkyl isomers is described. The preponderance of the latter over the former is rationalized by the stereoelectronic conformational preference of the C4-alkoxy group.