cssi/SciSciGPT-SciSciNet huggingface dataset:
Strong Imbalanced Turbulence

We consider stationary, forced, imbalanced, or cross helical MHD Alfvenic turbulence where the waves traveling in one direction have higher amplitudes than the opposite waves. This paper is dedicated to so-called strong turbulence, which cannot be treated perturbatively. Our main result is that the anisotropy of the weak waves is stronger than the anisotropy of strong waves. We propose that critical balance, which was originally conceived as a causality argument, has to be amended by what we call a propagation argument. This revised formulation of critical balance is able to handle the imbalanced case and reduces to the old formulation in the balanced case. We also provide a phenomenological model of energy cascading and discuss the possibility of self-similar solutions in a realistic setup of driven turbulence.
Photon antibunching from oriented conducting polymer nanostructures

It is shown in this paper that oriented nanostructures from single-molecules of a semiconducting polymer act as single-quantum emitters. The polymer system studied here is a cyano-substituted variant of polyphenylene vinylene (CN-PPV, H. W. Sands corp.) High-resolution fluorescence was used to image the polymer nanostructures. The modulation depth and 1/e rise time were found to be the same for varied pump intensity and are highly reproducible from particle to particle
Topological defects and cosmology

Many particle physics models of matter admit solutions corresponding to stable or long-lived topological defects. In the context of standard cosmology it is then unavoidable that such defects will form during phase transitions in the very early Universe. Certain types of defects lead to disastrous consequences for cosmology, others may play a useful role, as possible seeds for the formation of structure in the Universe, or in mediating baryon number violating processes. In all cases, topological defects lead to a fruitful interplay between particle physics and cosmology.
Soft Lithographic Fabrication of Microresonators

Using ultra-high-Q toroid microcavity masters, soft lithography is applied to fabricate polymer microcavity arrays with Q factors in excess of 106 . This technique produces resonators with material-limited quality factors.
M13-templated magnetic nanoparticles for targeted in vivo imaging of prostate cancer

Molecular imaging allows clinicians to visualize the progression of tumours and obtain relevant information for patient diagnosis and treatment. Owing to their intrinsic optical, electrical and magnetic properties, nanoparticles are promising contrast agents for imaging dynamic molecular and cellular processes such as protein-protein interactions, enzyme activity or gene expression. Until now, nanoparticles have been engineered with targeting ligands such as antibodies and peptides to improve tumour specificity and uptake. However, excessive loading of ligands can reduce the targeting capabilities of the ligand and reduce the ability of the nanoparticle to bind to a finite number of receptors on cells. Increasing the number of nanoparticles delivered to cells by each targeting molecule would lead to higher signal-to-noise ratios and would improve image contrast. Here, we show that M13 filamentous bacteriophage can be used as a scaffold to display targeting ligands and multiple nanoparticles for magnetic resonance imaging of cancer cells and tumours in mice. Monodisperse iron oxide magnetic nanoparticles assemble along the M13 coat, and its distal end is engineered to display a peptide that targets SPARC glycoprotein, which is overexpressed in various cancers. Compared with nanoparticles that are directly functionalized with targeting peptides, our approach improves contrast because each SPARC-targeting molecule delivers a large number of nanoparticles into the cells. Moreover, the targeting ligand and nanoparticles could be easily exchanged for others, making this platform attractive for in vivo high-throughput screening and molecular detection.
CATEGORIFICATIONS OF THE COLORED JONES POLYNOMIAL

The colored Jones polynomial of links has two natural normalizations: one in which the n-colored unknot evaluates to [n + 1], the quantum dimension of the (n + 1)-dimensional irreducible representation of quantum , and the other in which it evaluates to 1. For each normalization we construct a bigraded cohomology theory of links with the colored Jones polynomial as the Euler characteristic.
A sensitivity study of the clustering approach to workload modeling

If an adequate product-form model of an interactive system can be built, if the users' behaviors can be accurately modeled by probabilistic graphs, and if the workload and the model of it to be constructed are stationary, then a perfectly accurate workload model of a given workload can be constructed by grouping together all commands with identical characteristics. If a clustering technique that groups together commands with similar-characteristics is applied, is the workload model produced still acceptably accurate? This paper addresses this question (and other similar ones) by taking an experimental approach. The answer is that, in the case considered here, the accuracy is still acceptable if certain conditions are satisfied.
Holographic entropy and Calabi`s diastasis

The entanglement entropy for interfaces and junctions of two-dimensional CFTs is evaluated on holographically dual half-BPS solutions to six-dimensional Type 4b supergravity with m anti-symmetric tensor supermultiplets. It is shown that the moduli space for an N-junction solution projects to N points in the Kahler manifold SO(2;m)= (SO(2) SO(m)). For N = 2 the interface entropy is expressed in terms of the central charge and Calabi's diastasis function on SO(2;m)= (SO(2) SO(m)), thereby lending support from holography to a proposal of Bachas, Brunner, Douglas, and Rastelli. For N = 3, the entanglement entropy for a 3-junction decomposes into a sum of diastasis functions between pairs, weighed by combinations of the three central charges, provided the ux charges are all parallel to one another or, more generally,
Theory of polarographic maxima of the first kind

Abstract Maxima of the first kind involve streaming that arises from inequalities of the surface tension at different parts of the mercury drop. These inequalities arise from differences in the local interfacial potential and the latter arise from a non-uniform current-distribution. It is pointed out that the requisite differences in interfacial potential can arise only in the region of the rising part of the polarographic step, and only if the concentration of depolarizer exceeds some particular lower value. Thus, one expects quite narrow streaming maxima: contrary to previous ideas, it is negative maxima that are “normal” and positive ones that are anomalous. Positive maxima cover a wider range of potentials because the flux of depolarizer, induced by the streaming, prevents concentration polarization at the neck of the drop. Experiments with fine-tipped capillaries, designed to decrease the non-uniform current-distribution, have been inconclusive because the measured currents were at least partly controlled by the resistance and not solely by the extent of shielding.
Electrochromic Nanocrystal Quantum Dots

Incorporating nanocrystals into future electronic or optoelectronic devices will require a means of controlling charge-injection processes and an understanding of how the injected charges affect the properties of nanocrystals. We show that the optical properties of colloidal semiconductor nanocrystal quantum dots can be tuned by an electrochemical potential. The injection of electrons into the quantum-confined states of the nanocrystal leads to an electrochromic response, including a strong, size-tunable, midinfrared absorption corresponding to an intraband transition, a bleach of the visible interband exciton transitions, and a quench of the narrow band-edge photoluminescence.
Eccentricity evolution of giant planet orbits due to circumstellar disk torques

Abstract The extrasolar planets discovered to date possess unexpected orbital elements. Most orbit their host stars with larger eccentricities and smaller semi-major axes than similarly sized planets in our own Solar System do. It is generally agreed that the interaction between giant planets and circumstellar disks (Type II migration) drives these planets inward to small radii, but the effect of these same disks on orbital eccentricity, ϵ, is controversial. Several recent analytic calculations suggest that disk–planet interactions can excite eccentricity, while numerical studies generally produce eccentricity damping. This paper addresses this controversy using a quasi-analytic approach, drawing on several preceding analytic studies. This work refines the current treatment of eccentricity evolution by removing several approximations from the calculation of disk torques. We encounter neither uniform damping nor uniform excitation of orbital eccentricity, but rather a function d ϵ / d t that varies in both sign and magnitude depending on eccentricity and other Solar System properties. Most significantly, we find that for every combination of disk and planet properties investigated herein, corotation torques produce negative values of d ϵ / d t for some range in ϵ within the interval [0.1, 0.5]. If corotation torques are saturated, this region of eccentricity damping disappears, and excitation occurs on a short timescale of less than 0.08 Myr. Thus, our study does not produce eccentricity excitation on a timescale of a few Myr—we obtain either eccentricity excitation on a short time scale, or eccentricity damping on a longer time scale. Finally, we discuss the implications of this result for producing the observed range in extrasolar planet eccentricity.
Microfluidic technologies for accelerating the clinical translation of nanoparticles

Using nanoparticles for therapy and imaging holds tremendous promise for the treatment of major diseases such as cancer. However, their translation into the clinic has been slow because it remains difficult to produce nanoparticles that are consistent 'batch-to-batch', and in sufficient quantities for clinical research. Moreover, platforms for rapid screening of nanoparticles are still lacking. Recent microfluidic technologies can tackle some of these issues, and offer a way to accelerate the clinical translation of nanoparticles. In this Progress Article, we highlight the advances in microfluidic systems that can synthesize libraries of nanoparticles in a well-controlled, reproducible and high-throughput manner. We also discuss the use of microfluidics for rapidly evaluating nanoparticles in vitro under microenvironments that mimic the in vivo conditions. Furthermore, we highlight some systems that can manipulate small organisms, which could be used for evaluating the in vivo toxicity of nanoparticles or for drug screening. We conclude with a critical assessment of the near- and long-term impact of microfluidics in the field of nanomedicine.
Prediction of effective thermo-mechanical properties of particulate composites

A micromechanics-based model is developed to predict the effective thermo-mechanical properties of energetic materials, which are composite materials made from agglomeration of particles of a range of sizes. A random packing algorithm is implemented to construct a representative volume element for the heterogeneous material based on the experimentally determined particle diameter distribution. The effective mechanical properties of the material are then evaluated through finite element modeling, while its thermal properties are determined through a finite volume approach. The model is first carefully validated against results from the literature and is then used to estimate the thermo-mechanical properties of particular energetic materials. Good agreement is found between experimental results and predictions. The stress-bridging phenomenon in the particulate materials is captured by the model. Thermodynamic averaging is shown to be a poor representation for the estimation of thermo-mechanical properties of these heterogeneous materials.
Implementation of the Walrasian correspondence without continuous, convex, and ordered preferences

This paper consideres the problem of designing “better” mechanisms whose Nash allocations coincide with constrained Walrasian allocations for non-neoclassical economies under the minimal possible assumptions. We show that no assumprions on preferences are needed for feasible and continuous implementation of the constrained Walraisan correspondence. Further, under the monotonicity assumption, we present a mechanism that is completely feasible and continuous. Hence, no continuity and convexity assumptions on preferences are required, and preferences may be nontotal or nontransitive. Thus, this paper gives a somewhat positive answer to the question raised in the literature by showing that, even for non-neoclassical economies, there are “incentive-compatible”, “privacy preserving”, and “well-behaved” mechanisms which yield Pareto-efficient and individually rational allocations at Nash equilibria.
ENERGY AND SYSTEM SIZE DEPENDENCE STUDY OF THE PERCOLATION PHASE TRANSITION

Multiparticle production at high energies is described in terms of color strings stretched between the projectile and target. As the string density increases, overlap in the transverse plane leads to cluster formation. At some critical density a macroscopic cluster appears, spanning the entire system. This marks the percolation phase transition. Data from p+p, d+Au and Au+Au collisions at RHIC has been analyzed using the STAR detector to obtain the percolation density parameter, η. The particle pT spectrum from 200 GeV p+p data is parametrized using a power law. Values of the fit parameters are used in the d+Au and Au+Au analysis. For 200 GeV Au+Au collisions, the value of η is found to lie above the critical percolation threshold, while for other collision systems and energies, it is below the critical value. This supports the idea of string percolation, which at high enough string density is a possible mechanism to explore the hadronic phase transition to a quark-gluon plasma.
The effect of rotation on the hydrodynamics of stellar collapse

Using values of d, γmin, and γmax that Van Riper (1978) has found most promising for a hydrodynamic envelope ejection, we have shown that even a small amount of rotation in the initial core can stop its collapse before nuclear densities are reached. We expected χi > 0.02 to produce significant deviations from a spherically symmetric collapse, but have found that χi as much as ten times smaller than this will not allow the core to reach densities as high as in the spherical collapse. In no case, however, does the core flatten very much, nor does the value of β become very large. Low final β's preclude the formation of an axisymmetric torus. They also indicate that deformation of an iron core into a triaxial configuration or fragmentation of the core during its collapse is an extremely unlikely event. (Note: Classically, β must exceed 0.27 before a dynamic instability to non-axisymmetric perturbations is encountered.)
Distance measures for dynamic citation networks

Abstract Acyclic digraphs arise in many natural and artificial processes. Among the broader set, dynamic citation networks represent an important type of acyclic digraph. For example, the study of such networks includes the spread of ideas through academic citations, the spread of innovation through patent citations, and the development of precedent in common law systems. The specific dynamics that produce such acyclic digraphs not only differentiate them from other classes of graphs, but also provide guidance for the development of meaningful distance measures. In this article, we develop and apply our sink distance measure together with the single-linkage hierarchical clustering algorithm to both a two-dimensional directed preferential attachment model as well as empirical data drawn from the first quarter-century of decisions of the United States Supreme Court. Despite applying the simplest combination of distance measure and clustering algorithm, analysis reveals that more accurate and more interpretable clusterings are produced by this scheme.
Sources for Metals in the Intergalactic Medium

We present a discussion of possible sources of C, O, and Si in the intergalactic medium (IGM) using the yields of very massive stars (VMSs) and Type II supernovae (SNe II). The chemical evolution of the IGM is considered on the basis of analytical phenomenological models of hierarchical structure formation and the required metal production rates. Two regimes are considered: one for gas expulsion by VMSs and SNe II in low-mass halos prior to dissociation of H_2 molecules and reionization, and the other for later SN II-driven outflows from intermediate-mass halos. We use recent data on the abundances of C, O, and Si in the IGM inferred from two UV background (UVB) models. We show that the values of [C/O]_(IGM) and [Si/C]_(IGM) inferred from the UVB model using quasars only cannot be explained by any existing stellar models. To account for the elemental ratios in the IGM by stellar models requires that a softer UVB model be used in calculating the elemental abundances from the data on ionic species. This then permits a solution using the yields of VMSs and SNe II. The results, in particular [Si/C]_(IGM), show that VMSs must provide ≳15% of the C in the IGM. The preferred scenario is that VMSs in low-mass halos provided between 15% and 60% of the C in the regime of very high redshift (z ≳15) and that galactic outflows provided the remainder during later epochs (4 < z ≾6). Thus, there is a large gap in z between metal production by VMSs very early in the chemical evolution of the IGM and subsequent contributions from galactic outflows. It is not possible to explain the observations by just SN II sources associated with galactic outflows. The observational estimate of [O/H]_(IGM) implies a high [Fe/H]_(IGM) ≥ -3 for all cases considered (including the case of a pure VMS source). This raises problems with regard to observations of metal-poor stars in the Galaxy. In addition, the [O/Fe] values for SN II models are in conflict with stellar observations, which indicate that the calculated average Fe yields of SNe II are a factor of ~2 too high. These issues and the general problem of relating abundances in the IGM to those in metal-poor stars remain to be investigated.
Tandem Chain Extension-Aldol Reaction: Syn Selectivity with a Zinc Enolate

A tandem chain extension-aldol reaction was developed in which beta-keto esters are transformed to alpha-substituted-gamma-keto esters in an efficient zinc-mediated, one-pot reaction. The diastereoselectivity of the reaction ranged from good to excellent with syn stereochemistry observed for beta-keto ester and amide substrates and anti-stereochemistry observed for a beta-keto imide. [reaction: see text]
Synthesis, Conformation, and Metabolism of a Selenium Bilirubin

A symmetrical C(10)-selena-bilirubin analog, 8,12-bis(2-carboxyethyl)-7,13-dimethyl-2,3,17,18-tetraethyl-10-selenabiladiene-ac-1,19(21H,24H)-dione was synthesized from 8-(2-carboxyethyl)-2,3-diethyl-7-methyl-(10H)-dipyrrin-1-one in one step by reaction with diselenyl dichloride. The selena-rubin exhibited UV-vis and NMR spectroscopic properties similar to those of the parent mesobilirubin, and like bilirubin and mesobilirubin, it adopts an intramolecularly hydrogen-bonded conformation, shaped like a ridge-tile but with a steeper pitch. The longer C–Se bond lengths (2.2 A) and smaller bond angles at C–Se–C (88°), as compared to C–CH2–C (∼1.5 A, ∼106°), lead to an interplanar angle between the two dipyrrinones of only 72°, which is considerably less than that of bilirubin (∼100°) and close to that (74°) of its 10-thia-rubin analog. Despite the conformational distortion, the sensitivity of Se toward oxidation and the typically weak C–Se bond, the selena-rubin is metabolized in normal rats, like bilirubin, to acyl glucuronides, which are secreted into bile. In mutant (Gunn) rats lacking bilirubin glucuronosyl transferase (UGT1A1), glucuronide or other metabolites of the selena-rubin were not detected in bile, demonstrating the importance of hepatic glucuronidation for its biliary excretion.
Asymptotic Beam Theory for Planar Deformation of Initially Curved Isotropic Strips

The Variational Asymptotic Method (VAM) is used to develop a beam theory for the planar deformation of isotropic strips with initial in-plane curvature. This VAM-based theory provides asymptotically exact expressions for the strain energy per unit length and the cross-sectional stress and strain in terms of 1D generalized strain variables. It is rst linearized and successfully veried by comparison with elasticity solutions in the literature. It is then used to carry out verication for certain aspects of the computer program VABS (Variational Asymptotic Beam Section). In particular, the comparison shows that variations of cross-sectional stinesses versus initial curvature obtained from VABS 3.3 are in error, and that corrections embodied in VABS 3.4 capture the correct behavior. Finally, two dierent methodologies are proposed, both of which can be implemented in VABS in the future to improve the results: a partial transformation to generalized Timoshenko theory and evaluation of the second-order warping.
Syntheses of 1-thio-D-xylose and D-ribose esters of diorganoarsinous acids and their anticancer activity

Several thio-D-xylose and D-ribose esters of dialkylarsinous acids have been synthesized. The crystal structure of 1-S-dimethylarsino-β-D-xylopyranose, 7a, has been obtained. Growth inhibition studies of about 60 strains of human cancer cells have been obtained in vitro for compounds 6a, 7a, 13, and 14. The results reveal that these compounds display a strong inhibition to subpanels of leukemia cells in vitro and high selectivity in inhibiting the growth of cancer cells. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:199–206, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20388
Bo. G Malmström (1927–2000)

We lost a great scientist and a dear friend on 9 February this year. Bo Malmstrom (see Photograph) was a very special person: he was passionate about everything he did, and he did many things. I can only cover a few of his activities in this tribute. Note that Bo himself wrote a much more thorough account in his article ‘A Life with the Metals of Life’ – it is a good read.
A Two-Dimensional Drift Chamber

A two-dimensional drift chamber with a thin printed-circuit tape delay line positioned between two close sense wires was built and tested in a muon beam at Fermilab. A special resolution of ? = 1 mm in the coarse dimension is obtained with a collimated Fe55 source and ? = 3 mm in the muon beam.
Discovery of an Obscured Broad-Line Region in the High-Redshift Radio Galaxy MRC 2025-218.

This Letter presents infrared spectra taken with the newly commissioned near-infrared spectrometer (NIRSPEC) on the Keck II telescope of the high-redshift radio galaxy MRC 2025-218 (z = 2.63). These observations represent the deepest infrared spectra of a radio galaxy to date and have allowed for the detection of Hβ, [O III] λλ4959, 5007, [O I] λ6300, Hα, [N II] λλ6548, 6583, and [S II] λλ6716, 6713. The Hα emission is very broad (FWHM = 9300 km s-1) and luminous (2.6 × 1044 ergs s-1), and it is very comparable to the line widths and strengths of radio-loud quasars at the same redshift. This strongly supports active galactic nucleus unification models linking radio galaxies and quasars, although we discuss some of the outstanding differences. The line [O III] λ5007 is extremely strong and has extended emission with large relative velocities toward the nucleus. We also derive that if the extended emission is due to star formation, each knot has a star formation rate comparable to a Lyman-break galaxy at the same redshift.
Competition between insertion and conjugate addition in nickel-catalyzed couplings of enones with unsaturated functional groups

Abstract The intra- and intermolecular couplings of enones with alkynes or enones in the presence of organozincs under Ni(COD) 2 catalysis resulted in three general reaction pathways: direct conjugate addition, cyclization with alkylation, and cyclization with reduction. The effects of substrate structural variations on selectivities among these three pathways were investigated.
Protostellar Outflow Evolution in Turbulent Environments

The link between turbulence in star-forming environments and protostellar jets remains controversial. To explore issues of turbulence and fossil cavities driven by young stellar outflows, we present a series of numerical simulations tracking the evolution of transient protostellar jets driven into a turbulent medium. Our simulations show both the effect of turbulence on outflow structures and, conversely, the effect of outflows on the ambient turbulence. We demonstrate how turbulence will lead to strong modifications in jet morphology. More importantly, we demonstrate that individual transient outflows have the capacity to re-energize decaying turbulence. Our simulations support a scenario in which the directed energy/momentum associated with cavities is randomized as the cavities are disrupted by dynamical instabilities seeded by the ambient turbulence. Consideration of the energy power spectra of the simulations reveals that the disruption of the cavities powers an energy cascade consistent with Burgers'-type turbulence and produces a driving scale length associated with the cavity propagation length. We conclude that fossil cavities interacting either with a turbulent medium or with other cavities have the capacity to sustain or create turbulent flows in star-forming environments. In the last section, we contrast our work and its conclusions with previous studies which claim that jets cannot be the source of turbulence.
Vertex operator algebras, generalized doubles and dual pairs

Let V be a simple vertex operator algebra and G a finite automorphism group. Then there is a natural right G-action on the set of all inequivalent irreducible V-modules. Let \({\cal S}\) be a finite set of inequivalent irreducible V-modules which is closed under the action of G. There is a finite dimensional semisimple associative algebra \(A_{\alpha}(G,{\cal S})\) for a suitable 2-cocycle \(\alpha\) naturally determined by the G-action on \({\cal S}\) such that \(A_{\alpha}(G,{\cal S})\) and the vertex operator algebra \(V^G\) form a dual pair on the sum of V-modules in \({\cal S}\) in the sense of Howe. In particular, every irreducible V-module is completely reducible \(V^G\)-module.
Toeplitz matrix based sparse error correction in system identification: Outliers and random noises

In this paper, we consider robust system identification under sparse outliers and random noises. In our problem, system parameters are observed through a Toeplitz matrix. All observations are subject to random noises and a few are corrupted with outliers. We reduce this problem of system identification to a sparse error correcting problem using a Toeplitz structured real-numbered codingmatrix. We prove the performance guarantee of Toeplitz structured matrix in sparse error correction. Thresholds on the percentage of correctable errors for Toeplitz structured matrices are also established. When both outliers and observation noise are present, we have shown that the estimation error goes to 0 asymptotically as long as the probability density function for observation noise is not “vanishing” around 0.
The rational cohomology ring of the moduli space of abelian 3-folds

The rational cohomology ring of A_3, the moduli space of abelian 3-folds is computed. This is isomorphic to the the rational cohomology ring of the group Sp_3(Z) of 6x6 integral symplectic matrices. The main ingredients in the computation are (1) Looijenga's computation of the rational cohomology ring of M_3, the moduli space of smooth projective curves of genus 3, and (2) the stratified Morse theory of Goresky and MacPherson, which we use to compute the homology of the jacobian locus (in the rank 3 Siegel upper half plane), or equivalently of the extended Torelli group in genus 3. In the revised version, we also compute the rational cohomology of the Satake compactification of A_3.
Taxicabs and sums of two cubes

Our story begins in 1913, when the distinguished British mathematician G. H. Hardy received a bulky envelope from India full of page after page of equations. Every famous mathematician periodically receives letters from cranks who claim to have proven the most wonderous results. Sometimes the proofs, incorrect or incoherent, are included. At other times the writer solicits a reward in return for revealing his discoveries. Now this letter to Hardy, which was from a poor clerk in Madras by the name of Ramanujan, was filled with equations, all given without any sort of proof. Some of the formulas were well-known, mere exercises; while many of the others looked preposterous to Hardy's trained eye. Who would have blamed Hardy if he had returned this missive to the sender, unread? And in fact, Ramanujan had previously sent his results to two other British mathematicians, each of whom had done just that! But instead Hardy gave some thought to these "wild theorems. Theorems such as he had never seen before, nor imagined."' And together, he and J. E. Littlewood, another eminent mathematician with whom Hardy often worked, succeeded in proving some of Ramanujan's amazing identities. At this point Hardy realized that this letter was from a true mathematical genius, and he became determined that Ramanujan should come to England to pursue his mathematical researches. Using travel money provided by Hardy's college, Ramanujan arrived in 1914. Over the next several years he continued to produce and publish highly original material, and he also collaborated with Hardy on a number of outstanding papers. In 1918, at the age of 30, Ramanujan was elected a Fellow of the Royal Society and also of Trinity College, both signal honors which he richly deserved. Unfortunately, in the colder climate of England he contracted tuberculosis. He returned to his native Madras and died, in 1920, at the age of 33. During all of Ramanujan's life, he considered numbers to be his personal friends. To illustrate, Hardy tells the story of how one day he visited Ramanujan in the hospital. At a loss for something to say, Hardy remarked that he had arrived at the hospital in taxicab number 1729. "It seemed to me," he continued, "a rather dull number." To which Ramanujan replied "No, Hardy! It is a very interesting number. It is the smallest number expressible as a sum of two cubes in two different ways:"2
Inhibitors of an AdoMet-dependent 3-amino-3-carboxypropyl transferase and their use as ligands for protein affinity chromatography

Abstract The screening of potential affinity ligands and the development of a two-stage affinity purification of an S -adenosylmethionine-dependent 3-amino-3-carboxypropyl transferase involved in the biosynthesis of the β-lactam antibiotic nocardicin A is described from a cell-free extract of Nocardia uniformis subsp. tsuyamanesis . This protein is particularly sensitive to ion exchange and salt effects necessitating a pair of neutral ligands to be used in the final purification.
Relaxation of hypotheses in LaSalle-Krasovskii type invariance results

The usual invariance results for asymptotic stability for continuous autonomous finite-dimensional dynamical systems involve a positive definite Lyapunov function whose time derivative along the system motions is negative semi-definite (along with certain invariance conditions). This is equivalent to requiring that along the system motions, the Lyapunov function is non-increasing at all time with increasing time. In this paper we establish an invariance result for asymptotic stability for continuous and discontinuous non-autonomous finite-dimensional dynamical systems, which requires a positive definite Lyapunov function which when evaluated along the system motions is non-increasing only on certain unbounded discrete time sets E with increasing time. This allows that between the time instants determined by E, the Lyapunov function may increase (i.e., over some finite time intervals, the system may exhibit unstable behavior). We also show that the usual invariance theorem for asymptotic stability reduces to the invariance theorem for continuous dynamical systems presented herein. In addition, we establish a variant to the above result involving estimates of the asymptotic behavior of the system's motions. We apply our results to two examples. One of these involves the stabilization of conservative mechanical systems using energy dissipation intermittently.
Hypercovers and simplicial presheaves

We use hypercovers to study the homotopy theory of simplicial presheaves. The main result says that model structures for simplicial presheaves involving local weak equivalences can be constructed by localizing at the hypercovers. One consequence is that the fibrant objects can be explicitly described in terms of a hypercover descent condition, and the fibrations can be described by a relative descent condition. We give a few applications for this new description of the homotopy theory of simplicial presheaves.
GAS-PHASE OXYGEN GRADIENTS IN STRONGLY INTERACTING GALAXIES. I. EARLY-STAGE INTERACTIONS

A consensus is emerging that interacting galaxies show depressed nuclear gas metallicities compared to isolated star-forming galaxies. Simulations suggest that this nuclear underabundance is caused by interaction-induced inflow of metal-poor gas and that this inflow concurrently flattens the radial metallicity gradients in strongly interacting galaxies. We present metallicities of over 300 H II regions in a sample of 16 spirals that are members of strongly interacting galaxy pairs with mass ratio near unity. The deprojected radial gradients in these galaxies are about half of those in a control sample of isolated, late-type spirals. Detailed comparison of the gradients with simulations shows remarkable agreement in gradient distributions, the relationship between gradients and nuclear underabundances, and the shape of profile deviations from a straight line. Taken together, this evidence conclusively demonstrates that strongly interacting galaxies at the present day undergo nuclear metal dilution due to gas inflow, as well as significant flattening of their gas-phase metallicity gradients, and that current simulations can robustly reproduce this behavior at a statistical level.
Beyond Civil Society: An Organizational Perspective on State–NGO Relations in the People's Republic of China

In the last two decades, the People's Republic of China has witnessed an explosion of NGOs. What will the implications be for state–society relations? This article, drawing upon research conducted at seven Chinese NGOs, critiques two approaches to analysing this problem: the civil society framework and the privatization perspective. It then proffers a third way: an approach based on organizational analysis. Both the civil society and privatization perspectives assume a zero-sum game between a monolithic state and NGOs/citizens. Yet empirical evidence reveals that Chinese NGOs are often much more interested in building alliances with state agencies and actors than in autonomy from the government. From an organizational perspective, this makes sense. As organizations, both NGOs and state agencies need to ensure a constant supply of necessary resources for the firm to survive, and their strategies for achieving this goal will be constrained by their actors' own institutional experiences and the cultural fram...
International integration: a hope for a greener China?

Purpose – In recent years, “trade up” argument has gained momentum. It argues that international integration can benefit developing countries' environments by fostering the adoption of voluntary environmental standards, such as International Organization for Standardization (ISO) 14001 certification. Based on this argument, a social marketing program that encourages greenness among buyers, especially downstream industrial buyers (for example, auto industry) in developed countries could motivate firms in developing countries go green. The purpose of this paper is to provide an investigation on whether “trade up” is a real hope, and what is required to make it real.Design/methodology/approach – Theoretical modeling and case studies.Findings – This paper finds that international trade does gear up the adoption of ISO 14001 standards in China through increasing pressures from international green customers. However, our analyses suggest that the adoption of ISO 14001 certification does not necessarily improve ...
REGIME-SENSITIVE COINTEGRATION WITH AN APPLICATION TO INTEREST-RATE PARITY

There exist a variety of reasons for the failure to find a unique cointegrating relationship between economic time series where one would normally be expected on the basis of economic theory. Among these are the testing procedure, the span of the data set, the choice of lag length in generating the test statistic, the presence of structural breaks, and the presence of cointegration only beyond some threshold. We propose the concept of regime-sensitive cointegration whereby the underlying series need not be cointegrated at all times. We show that cointegration can be switched off when a common stochastic trend is added. Alternatively, cointegration can be switched on or off because series normally believed to contain a unit actually do not. This implies that a linear combination of such variables need not be cointegrated. To illustrate the concept empirically, we test the hypothesis of interest-rate parity, and related hypotheses, using daily Eurorates for the United States and Canada.
Custodial isospin violation in the Lee-Wick standard model

We analyze the tension between naturalness and isospin violation in the Lee-Wick standard model (LW SM) by computing tree-level and fermionic one-loop contributions to the post-LEP electroweak parameters ($\stackrel{^}{S}$, $\stackrel{^}{T}$, $W$, and $Y$) and the $Z{b}_{L}{\overline{b}}_{L}$ coupling. The model is most natural when the LW partners of the gauge bosons and fermions are light, but small partner masses can lead to large isospin violation. The post-LEP parameters yield a simple picture in the LW SM: the gauge sector contributes to $Y$ and $W$ only, with leading contributions arising at tree level, while the fermion sector contributes to $\stackrel{^}{S}$ and $\stackrel{^}{T}$ only, with leading corrections arising at one loop. Hence, $W$ and $Y$ constrain the masses of the LW gauge bosons to satisfy ${M}_{1}$, ${M}_{2}\ensuremath{\gtrsim}2.4\text{ }\text{ }\mathrm{TeV}$ at 95% C.L. Likewise, experimental limits on $\stackrel{^}{T}$ reveal that the masses of the LW fermions must satisfy ${M}_{q}$, ${M}_{t}\ensuremath{\gtrsim}1.6\text{ }\text{ }\mathrm{TeV}$ at 95% C.L. if the Higgs mass is light and tend to exclude the LW SM for any LW fermion masses if the Higgs mass is heavy. Contributions from the top-quark sector to the $Z{b}_{L}{\overline{b}}_{L}$ coupling can be even more stringent, placing a lower bound of 4 TeV on the LW fermion masses at 95% C.L.
Nicotinamide treatment in a murine model of familial tumoral calcinosis reduces serum Fgf23 and raises heart calcium

Mutations in the GALNT3 gene result in familial tumoral calcinosis, characterized by persistent hyperphosphatemia and ectopic calcific masses in soft tissues. Since calcific masses often recur after surgical removal, a more permanent solution to the problem is required. Nicotinamide is reported to lower serum phosphate by decreasing sodium-dependent phosphate co-transporters in the gut and kidney. However, its effectiveness in tumoral calcinosis remains unknown. In this study, we investigated nicotinamide as a potential therapy for tumoral calcinosis, using a murine model of the disease-Galnt3 knockout mice. Initially, five different doses of nicotinamide were given to normal heterozygous mice intraperitoneally or orally. Treatment had no effect on serum phosphate levels, but serum levels of a phosphaturic hormone, fibroblast growth factor 23 (Fgf23), decreased in a dose-dependent manner. Subsequently, high-dose nicotinamide (40mM) was tested in Galnt3 knockout mice fed a high phosphate diet. The radiographic data pre- and post-treatment showed that nicotinamide did not reverse the calcification. However, the treatment retarded calcification growth after 4weeks, while in the untreated animals, calcifications increased in size. The therapy did not affect serum phosphate levels, but intact Fgf23 decreased in the treated mice. The treated mice also had increased calcium in the heart. In summary, nicotinamide did not alter serum phosphate levels, likely due to compensatory decrease in Fgf23 to counteract the phosphate lowering effect of nicotinamide. Although increased calcium accumulation in the heart is a concern, the therapy appears to slow down the progression of ectopic calcifications.
Extending Bauer's corollary to fractional derivatives

We comment on the method of Dreisigmeyer and Young J. Phys. A: Math. Gen.368297 to model nonconservative systems with fractional derivatives. It was previously hoped that using fractional derivatives in an action would allow us to derive a single retarded equation of motion using a variational principle. It is proven that, under certain reasonable assumptions, the method of Dreisigmeyer and Young fails.
Aeroelastic Analysis of Wings Using the Euler Equations with a Deforming Mesh

Modifications to the CFL3D three-dimensional unsteady Euler/Navier-Stokes code for the aeroelastic analysis of wings are described. The modifications involve including a deforming mesh capability that can move the mesh to continuously conform to the instantaneous shape of the aeroelastically deforming wing and also including the structural equations of motion for their simultaneous time integration with the governing flow equations. Calculations were performed using the Euler equations to verify the modifications to the code and as a first step toward aeroelastic analysis using the Navier-Stokes equations. Results are presented for the NACA 0012 airfoil and a 45-deg sweptback wing to demonstrate applications of CFL3D for generalized force computations and aeroelastic analysis. Comparisons are made with published Euler results for the NACA 0012 airfoil and with experimental flutter data for the 45-deg sweptback wing to access the accuracy of the present capability. These comparisons show good agreement and, thus, the CFL3D code may be used with confidence for aeroelastic analysis of wings. The paper describes the modifications that were made to the code and presents results and comparisons that assess the capability.
Nonlinear dynamics of wind waves: multifractal phase/time effects

Abstract. In addition to the bispectral coherence method, phase/time analysis of analytic signals is another promising avenue for the investigation of phase effects in wind waves. Frequency spectra of phase fluctuations obtained from both sea and laboratory experiments follow an F-β power law over several decades, suggesting that a fractal description is appropriate. However, many similar natural phenomena have been shown to be multifractal. Universal multifractals are quantified by two additional parameters: the Levy index 0 α 2 for the type of multifractal and the co-dimension 0 C1 1 for intermittence. The three parameters are a full statistical measure the nonlinear dynamics. Analysis of laboratory flume data is reported here and the results indicate that the phase fluctuations are 'hard multifractal' (α > 1). The actual estimate is close to the limiting value α = 2, which is consistent with Kolmogorov's lognormal model for turbulent fluctuations. Implications for radar and sonar backscattering from the sea surface are briefly considered.
Vaporization and Layering of Alkanols at the Oil/water Interface

This study of adsorption of normal alkanols at the oil/water interface with x-ray reflectivity and tensiometry demonstrates that the liquid to gas monolayer phase transition at the hexane/water interface is thermodynamically favourable only for long-chain alkanols. As the alkanol chain length is decreased, the change in excess interfacial entropy per area ΔSaσ decreases to zero. Systems with small values of ΔSaσ form multi-molecular layers at the interface instead of the monolayer formed by systems with much larger ΔSaσ. Substitution of n-hexane by n-hexadecane significantly alters the interfacial structure for a given alkanol surfactant, but this substitution does not fundamentally change the phase transition behaviour of the monolayers. These data show that the critical alkanol carbon number, at which the change in excess interfacial entropy per area decreases to zero, is approximately six carbons larger than the number of carbons in the alkane solvent molecules.
Outer Versus Inner Halo Globular Clusters: NGC 7492 Abundances

We have carried out a detailed abundance analysis for 21 elements in a sample of four RGB stars in the outer halo globular cluster NGC 7492 (RGC 25 kpc); we find [Fe/H] = -1.82 dex inferred from Fe I lines (-1.79 from Fe II) using high-dispersion (R = λ/Δλ = 35,000) spectra obtained with HIRES at the Keck Observatory. Most elements show no sign of star-to-star variation within our limited sample. We have, however, detected an anticorrelation between O and Na abundances similar to that seen in our previous analyses of inner halo GCs as well as in studies of relatively nearby GCs by others. We compare the abundance ratios in NGC 7492 with those we previously determined for the much closer old halo GCs M3 and M13. After making corrections for trends of abundance ratio with metallicity characteristic of halo stars, we find that for these three GCs, for each of the elements in common we deduce identical abundance ratios with respect to Fe to within the probable measurement uncertainties. Thus, the chemical history of the outer halo as exemplified by the metal-poor outer halo globular cluster NGC 7492 is indistinguishable from that of the inner halo, exemplified by M3 and M13, at least through the epoch of formation of these old globular clusters. This applies to the neutron capture processes as well.
Chemistry of an acyloxyiodinane, the intermediate in iodosobenzoate catalyzed cleavage of active esters

Abstract The 1-acetoxy-1,2-benziodoxol-3(1H)-one intermediate in the o -iodosobenzoate cleavage of p -nitrophenyl acetate can be directly observed in dimethyl sulfoxide.
The Nimbus III Michelson Interferometer

Michelson IR interferometer spectrometer /IRIS/ design calibration and performance onboard Nimbus 3 satellite, demonstrating data reduction and inflight calibration
Do Prehospital Trauma Center Triage Criteria Identify Major Trauma Victims

Objective: To evaluate anatomic, physiologic, and mechanism-of-injury prehospital triage criteria as well as the subjective criterion of provider "gut feeling." Design: Prospective analysis. Setting: A state without a trauma system or official trauma center designation. Patients: Patients treated by emergency medical services personnel statewide over a 1-year period who were injured and met at least one prehospital triage criterion for treatment at a trauma center. Main Outcome Measures: Outcome was analyzed for injury severity using the Injury Severity Score and mortality rates. A major trauma victim (MTV) was defined as a patient having an Injury Severity Score of 16 or greater. The yield of MTV and mortality associated with each criterion was determined. Results: Of 5028 patients entered into the study, 3006 exhibited a singular entry criterion. Triage criteria tended to stratify into high-, intermediate-, and low-yield groups for MTV identification. Physiologic criteria were high yield and anatomic criteria were intermediate yield. Provider gut feeling alone was a low-yield criterion but served to enhance the yield of mechanism of injury criteria when the two criteria were applied in the same patient. Conclusions: A limited set of high-yield prehospital criteria are acceptable indicators of MTV. Isolated low- and intermediate-yield criteria may not be useful for initiating trauma center triage or full activation of hospital trauma teams. (Arch Surg. 1995;130:171-176)