cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and biological evaluation of 4-deacetoxypaclitaxel

Abstract 4-Deacetoxypaclitaxel ( 9 ) has been prepared in seven steps from paclitaxel (Taxol ® ). It is significantly less active than paclitaxel in tubulin-assembly and cytotoxicity bioassays.
WHAT MAKES AN ACCRETION-POWERED MILLISECOND PULSAR?

We investigate the dependence of pulse amplitudes of accreting millisecond pulsars on the masses of the neutron stars. Because pulsation amplitudes are suppressed as neutron stars become more massive, the probability of detection of pulsations decreases in systems that have been accreting for a long time. However, the probability of detectable pulsations is higher in transient systems where mass accretion is sporadic and the neutron star is likely to have a low mass. We propose this mechanism as the explanation of the small number of millisecond X-ray pulsars found to date, as well as their emergence as fast pulsars mostly in transient, low- systems. This mechanism can also quantitatively explain the lack of pulsars in the majority of low-mass X-ray binaries.
Black-Hole Singularities: A New Critical Phenomenon

The singularity inside a spherical charged black hole, coupled to a spherical, massless scalar field is studied numerically. The profile of the characteristic scalar field was taken to be a power of advanced time with an exponent $\ensuremath{\alpha}g0$. A critical exponent ${\ensuremath{\alpha}}_{\mathrm{c}\mathrm{r}\mathrm{i}\mathrm{t}}$ exists. For exponents below the critical one ($\ensuremath{\alpha}l{\ensuremath{\alpha}}_{\mathrm{c}\mathrm{r}\mathrm{i}\mathrm{t}}$) the singularity is a union of spacelike and null sectors, as is also the case for data with compact support. For exponents greater than the critical one ($\ensuremath{\alpha}g{\ensuremath{\alpha}}_{\mathrm{c}\mathrm{r}\mathrm{i}\mathrm{t}}$) an all-encompassing, spacelike singularity evolves, which completely blocks the ``tunnel'' inside the black hole, preventing the use of the black hole as a portal for hyperspace travel.
RAP: An end-to-end rate-based congestion control mechanism for realtime streams in the Internet

End-to-end congestion control mechanisms have been critical to the robustness and stability of the Internet. Most of today's Internet traffic is TCP, and we expect this to remain so in the future. Thus, having "TCP-friendly" behavior is crucial for new applications. However, the emergence of non-congestion-controlled realtime applications threatens unfairness to competing TCP traffic and possible congestion collapse. We present an end-to-end TCP-friendly rate adaptation protocol (RAP), which employs an additive-increase, multiplicative-decrease (AIMD) algorithm. It is well suited for unicast playback of realtime streams and other semi-reliable rate-based applications. Its primary goal is to be fair and TCP-friendly while separating network congestion control from application-level reliability. We evaluate RAP through extensive simulation, and conclude that bandwidth is usually evenly shared between TCP and RAP traffic. Unfairness to TCP traffic is directly determined by how TCP diverges from the AIMD algorithm. Basic RAP behaves in a TCP-friendly fashion in a wide range of likely conditions, but we also devised a fine-grain rate adaptation mechanism to extend this range further. Finally, we show that deploying RED queue management can result in an ideal fairness between TCP and RAP traffic.
The effects of structure on the catalytic activity and selectivity of V2O5/TiO2 for the reduction of NO by NH3

Abstract An investigation of the effect of catalyst structure on the activity and selectivity of TiO2 (anatase)-supported V2O5 for the selective catalytic reduction of NO by NH3 has been carried out. The structure of the catalyst and the adsorbed species present on the surface was characterized by in situ laser Raman spectroscopy (LRS), and the interaction of NH3 was investigated using temperature-programmed desorption (TPD). At vanadia loadings corresponding to less than a theoretical monolayer, the vanadia is present in the form of monomeric vanadyl and polymeric vanadate species. When the vanadia coverage exceeds a monolayer, crystallites of V2O5 form at the expense of the polymeric species. Analysis of the catalytic activity shows that the specific activity of the polymeric vanadates species is about 10 times greater than that of the monomeric vanadyl species. Monomeric species produce N2 as the principle reaction product, independent of the presence or absence of O2 in the feed, whereas polymeric vanadates species produce both N2 and N2O, with the selectivity to N2 decreasing with increasing concentrations of O2 in the feed. LRS experiments reveal that in the absence of O2 in the feed stream, the catalyst undergoes reduction but that in the presence of O2, the catalyst remains in a nearly fully oxidized state. TPD experiments indicate that a crucial step in the catalytic reduction of NO is the activation of adsorbed NH3 to produce NHx (x = 0 − 2) species. The removal of H atoms from adsorbed NH3 occurs via reaction with V O groups present in clusters of monomeric vanadyl species and in polymeric vanadate species, the latter being more reactive than the former. The observations reported in this study are interpreted in terms of a reaction mechanism, which accounts for the effects of catalyst structure and oxidation state on the observed properties.
Measurement of hyperfine structure and isotope shifts in the Dy 421-nm transition

A measurement of the hyperfine coefficients and isotope shifts for the atomic dysprosium 421.291 nm transition (4f106s2,J=8-->4f106s6p,J=9) using atomic beam laser-induced fluorescence spectroscopy is presented. A King plot analysis is performed to determine a specific mass shift of δνsms164-162=11(7) MHz for the 421 nm transition, confirming the pure 4f106s6p configuration of the excited state. This transition is currently being explored for laser cooling of an atomic beam of dysprosium used in a search for a temporal variation of the fine-structure constant.
A multi-item production planning model with setup times: algorithms, reformulations, and polyhedral characterizations for a special case

We study a special case of a structured mixed integer programming model that arises in production planning. For the most general case of the model, called PI, we have earlier identified families of facet–defining valid inequalities: (l, S) inequalities (introduced for the uncapacitated lot–sizing problem by Barany, Van Roy, and Wolsey), cover inequalities, and reverse cover inequalities. PI is 𝒩𝒫–hard; in this paper we focus on a special case, called PIC. We describe a polynomial algorithm for PIC, and we use this algorithm to derive an extended formulation of polynomial size for PIC. Projecting from this extended formulation onto the original space of variables, we show that (l, S) inequalities, cover inequalities, and reverse cover inequalities suffice to solve the special case PIC by linear programming. We also describe fast combinatorial separation algorithms for cover and reverse cover inequalities for PIC. Finally, we discuss the relationship between our results for PIC and a model studied previously by Goemans.
Supersymmetry, vacuum statistics, and the fundamental theorem of algebra

I give an interpretation of the fundamental theorem of algebra based on supersymmetry and the Witten index. The argument gives a physical explanation of why a real polynomial of degreen need not haven real zeroes, while a complex polynomial of degreen must haven complex zeroes. This paper also addresses in a general and model-independent way the statistics of the perturbative ground states (the states which correspond to classical vacua) in supersymmetric theories with complex and with real superfields.
Next-to-leading order QCD corrections to s-channel single top quark production and decay at the LHC.

We present a study of electroweak production of top and antitop quarks in the $s$-channel mode at the LHC, including next-to-leading order QCD corrections to the production and decay of the single (anti)top quark. The spin is preserved in production and decay by using the narrow width approximation for the (anti)top quark. We show the effect of different $O({\ensuremath{\alpha}}_{s})$ contributions on the inclusive cross section and various kinematic distributions at parton level after imposing relevant kinematic cuts to select $s$-channel single top quark events. We also discuss several possibilities for measuring the top quark polarization.
Determinants of the components of bid‐ask spreads on stocks

In this paper we show that George et al. (GKN, 1991) estimators of the adverse selection and order processing cost components of the bid-ask spread are biased due to intertemporal variations in the bid-ask spread. We use alternative estimators that correct this bias and that are applicable to individual securities, and estimate these cost components empirically using data on NYSE/AMEX stocks. As expected, our results indicate that on average adverse selection costs account for approximately 50% of the bid-ask spread, sharply higher than the estimates of 8-10% obtained by GKN for NASDAQ stocks and 21% that we obtain for NYSE/AMEX stocks using GKN's estimators. We then conduct cross-sectional regressions designed primarily to determine whether adverse selection costs vary across specialists after controlling for firm size and other factors. Consistent with previously established hypotheses, we find that adverse-selection costs vary across specialists, and that this variation is related to the number of securities that the specialist handles.
Adaptive perturbation theory: quantum mechanics and field theory

Adaptive perturbation is a new method for perturbatively computing the eigenvalues and eigenstates of quantum mechanical Hamiltonians that are widely believed not to be solvable by such methods. The novel feature of adaptive perturbation theory is that it decomposes a given Hamiltonian, H, into an unperturbed part and a perturbation in a way which extracts the leading non-perturbative behavior of the problem exactly. In this talk I will introduce the method in the context of the pure anharmonic oscillator and then apply it to the case of tunneling between symmetric minima. After that, I will show how this method can be applied to field theory. In that discussion I will show how one can non-perturbatively extract the structure of mass, wavefunction and coupling constant renormalization.
The static potential with hypercubic blocking

We measure the static potential from Wilson loops constructed using hypercubic blocked (HYP) links. The HYP potential agrees with the potential measured using thin links for distances r/a ≥ 2. We calculated the lowest order perturbative expansion of the lattice Coulomb potential of HYP links. These results are used in analyzing the static potential both on quenched and dynamical lattices. The statistical accuracy of the potential with HYP links improves by about an order of magnitude, giving a reliable scale even with limited statistics both on quenched and dynamical lattices.
Modeling of the channel-hopping anti-jamming defense in multi-radio wireless networks

Multi-radio (multi-interface, multi-channel) 802.11 and sensor networks have been proposed to increase network capacity and to reduce energy consumption, to name only a few of their applications. They are vulnerable, however, to jamming attacks, in which attackers block communication by radio interference or MAC-protocol violation. Two jamming countermeasures have been proposed, namely software-based channel hopping and error-correcting codes. In this paper, we introduce the problem of maximizing network goodput under jamming attacks through a combination of channel hopping and error-correction coding. We describe the solution space and investigate one point thereof, namely reactive defense against scanning attack. We develop a Markovian model of the reactive channel-hopping defense against the scanning jamming attack and validate it using simulation experiments. Our results suggest that an adaptive defense, based on our model, would improve the resiliency of multi-radio networks against jamming.
Adjoint-based optimization for understanding and suppressing jet noise

Advanced simulation tools, particularly large-eddy simulation techniques, are becoming capable of making quality predictions of jet noise for realistic nozzle geometries and at engineering relevant flow conditions. Increasing computer resources will be a key factor in improving these predictions still further. Quality prediction, however, is only a necessary condition for the use of such simulations in design optimization. Predictions do not themselves lead to quieter designs. They must be interpreted or harnessed in some way that leads to design improvements. As yet, such simulations have not yielded any simplifying principals that offer general design guidance. The turbulence mechanisms leading to jet noise remain poorly described in their complexity. In this light, we have implemented and demonstrated an aeroacoustic adjoint-based optimization technique that automatically calculates gradients that point the direction in which to adjust controls in order to improve designs. This is done with only a single flow solutions and a solution of an adjoint system, which is solved at computational cost comparable to that for the flow. Optimization requires iterations, but having the gradient information provided via the adjoint accelerates convergence in a manner that is insensitive to the number of parameters to be optimized. This paper, which follows from a presentation at the 2010 IUTAM Symposium on Computational Aero-Acoustics for Aircraft Noise Prediction, reviews recent and ongoing efforts by the author and co-workers. It provides a new formulation of the basic approach and demonstrates the approach on a series of model flows, culminating with a preliminary result for a turbulent jet.
Characterization of the Critical Sets of Quantum Unitary Control Landscapes

This work considers various families of quantum control landscapes (i.e. objective functions for optimal control) for obtaining target unitary transformations as the general solution of the controlled Schrodinger equation. We examine the critical point structure of the kinematic landscapes J F (U) = ||(U - W)A|| 2 and J P (U) = ||A|| 4 - |Tr(AA † W † U)| 2 defined on the unitary group U(H) of a finite-dimensional Hilbert space H. The parameter operator A E (H) is allowed to be completely arbitrary, yielding an objective function that measures the difference in the actions of U and the target W on a subspace of state space, namely the column space of A. The analysis of this function includes a description of the structure of the critical sets of these kinematic landscapes and characterization of the critical points as maxima, minima, and saddles. In addition, we consider the question of whether these landscapes are Morse-Bott functions on U(H). Landscapes based on the intrinsic (geodesic) distance on U(H) and the projective unitary group PU(H) are also considered. These results are then used to deduce properties of the critical set of the corresponding dynamical landscapes.
Polycyclic aromatic hydrocarbons as universal bases in peptide nucleic acid

Abstract Polycyclic aromatic hydrocarbons were found to be promising universal bases in PNA·DNA double helices. Several of the arenes paired promiscuously with any of the four canonical bases. However, the stabilities of the duplexes depended on the size and shape of the arene.
Infrared synchrotron radiation instrumentation and applications

Abstract Infrared synchrotron radiation (IRSR) is a blossoming field which has three working beamlines, U41R at the National Synchrotron Light Source, Brookhaven National Laboratory, USA, and two at the Institute of Molecular Sciences in Okasaki, Japan, with extensive research projects. There are also several new beamlines in the planning and development stages, both in the United States and abroad. IRSR offers a unique way to access the far infrared (30 μm to ∼ 1mm), which is a notoriously difficult region to work in. In particular, experiments that demand high brightness are well suited to IRSR just as they are in the X-ray region. The central issue in all of the experiments to date has been good signal to noise, which has been the focus of the instrumentation improvements at the U41R beamline. A commercial Fourier transform instrument was the chosen spectrometer. Then modifications were made in order to expand the usable region of the existing experiments, in both the far and near infrared. As an example of the performance of this beamline, I will focus on the reflection absorption spectroscopy results for adsorbates on clean surfaces in ultrahigh vacuum.
Ion‐beam‐sputter modification of the surface morphology of biological implants

The surface chemistry and texture of materials used for biological implants may significantly influence their performance and biocompatibility. Recent interest in the microscopic control of implant surface texture has led to the evaluation of ion-beam sputtering as a potentially useful surface roughening technique. Ion sources, similar to electron-bombardment ion thrusters designed for propulsive applications, are used to roughen the surfaces of various biocompatible alloys or polymer materials. These materials are typically used for dental implants, orthopedic prostheses, vascular prostheses, and artificial heart components. Masking techniques and resulting surface textures are described along with progress concerning evaluation of the biological response to the ion-beam-sputtered surfaces.
Effect of autoreclosing circuit breakers on transient stability in e.h.v. transmission systems

The authors have made a quantitative assessment of the effect of two types of autoreclosing circuit breaker on power-system stability, using the Atlas digital computer at Manchester University.
On the submodularity of influence in social networks

We prove and extend a conjecture of Kempe, Kleinberg, and Tardos (KKT) on the spread of influence in social networks.A social network can be represented by a directed graph where the nodes are individuals and the edges indicate a form of social relationship. A simple way to model the diffusion of ideas, innovative behavior, or "word-of-mouth" effects on such a graph is to consider an increasing process of "infected" (or active) nodes: each node becomes infected once an activation function of the set of its infected neighbors crosses a certain threshold value. Such a model was introduced by KKT in [7,8] where the authors also impose several natural assumptions: the threshold values are (uniformly) random to account for our lack of knowledge of the true values; and the activation functions are monotone and submodular, i.e. have "diminishing returns." The monotonicity condition indicates that a node is more likely to become active if more of its neighbors are active, while the submodularity condition, indicates that the marginal effect of each neighbor is decreasing when the set of active neighbors increases.For an initial set of active nodes s, let σ(S) denote the expected number of active nodes at termination. Here we prove a conjecture of KKT: we show that the function σ(S) is submodular under the assumptions above. We prove the same result for the expected value of any monotone, submodular function of the set of active nodes at termination.In other words, our results demonstrate that "local" submodularity is preserved "globally" under diffusion processes. This is of natural computational interest, as many optimization problems have good approximation algorithms for submodular functions. In particular, our results coupled with an argument in [7] imply that a greedy algorithm gives an (1-1/e-e)-approximation algorithm for maximizing σ(S) among all sets s of a given size. This result has important practical implications for many social network analysis problems, notably viral marketing.
Empirical Spectral Model of Surface Pressure Fluctuations

An empirical model of the surface pressure spectrum beneath a two-dimensional, zero-pressure-gradient boundary layer is presented that is based on the experimental surface pressure spectra measured by seven research groups. The measurements cover a large range of Reynolds number, 1.4 × 10 3 < Reθ < 2.34 × × 10 4 . The model is a simple function of the ratio of the timescales of the outer to inner boundary layer. It incorporates the effect of Reynolds number through the timescale ratio and compares well to experimental data. It is proposed that the effect of Reynolds number is more aptly described as the effect of the range of relevant scales. Spectral features of the experimental data and the scaling behavior of the surface pressure spectrum are also discussed.
Asymmetric synthesis of 2-deoxy-2-fluoro-γ-aldonolactones and their conversion to 2-deoxy-2-fluoropentoses

Abstract 2-Fluoro-2-deoxy-γ-xylonic and -lyxonic lactones, 7a and 7b , were prepared via the diastereoselective fluorination of the α,β-unsaturated chiral imide 5 followed by dihydroxylation. Lactones 7a and 7b were converted to 2-deoxy-2-fluoro-xylo- d -pyranose ( 1 ) and 2-deoxy-2-fluoro-lyxo- l -pyranose ( 2 ) by reduction and deprotection.
Thermocapillary Convection in Liquid Bridges with Undeformable Curved Surfaces

Thermocapillary convection in differentially heated cylindrical liquid bridges is investigated by two- and threedimensional numerical simulations. The nondeformable free surface is either e at or curved as determined by the e uid volume and the Young ‐Laplace equation. With Prandtl numbers of 1 and 4 and a e at surface, our computed results for onset of oscillations are in good agreement with linear theory. Convection is steady and axisymmetric at sufe ciently low values of Reynolds number with either e at or curved interfaces. Only steady convection is possibleat all Reynoldsnumbersconsidered in strictly axisymmetriccomputations. Transition to oscillatory threedimensional motions occurs as the Reynolds number increases beyond a critical value, dependent on the Prandtl number and liquid volume. Rotating waves with wave numbers of 1 or 2 are observed. The critical wave number depends on the Biot number. Heat loss from the free surface stabilizes the e ow, and the critical Reynolds number increases with increasing Biot number. With nonzero Biot number, two different branches can exist in the stability diagram. The numerical results are in reasonable agreement with experiments.
Utilitarianism for infinite utility streams: A new welfare criterion and its axiomatic characterization☆

A definition of a utilitarian social welfare relation (SWR) for infinite utility streams is proposed. Such a relation is characterized in terms of the Pareto, Anonymity and Partial Unit Comparability Axioms. The merits of the utilitarian SWR, relative to the more restrictive SWR induced by the overtaking criterion, are examined.
Enantioselective intramolecular aldehyde α-alkylation with simple olefins: direct access to homo-ene products.

A highly selective method for the synthesis of asymmetrically substituted carbocycles and heterocycles from unactivated aldehyde–olefin precursors has been achieved via enantioselective SOMO-catalysis. Addition of a catalytically generated enamine radical cation across a pendent olefin serves to establish a general asymmetric strategy toward the production of a wide range of formyl-substituted rings with alkene transposition. Conceptually, this novel mechanism allows direct access to “homo-ene”-type products.
Biomimetic studies towards the C28–C40 polycyclic domain of the azaspiracids

Abstract An acyclic intermediate representing a putative biomimetic precursor of the C28–C40 domain of the novel marine toxin azaspiracid was constructed convergently from C28–C34 and C35–C40 fragments. In studying the assembly of the C28–C34 dioxabicyclo[3.3.1]nonane system via an intramolecular hetero-conjugate addition upon a C34–C36 enone, a stereoselective C -Michael addition intervened to provide a highly substituted cyclohexane.
Binding energies in nonrelativistic field theories

Abstract Relativistic corrections communicate the binding energy of a bound state to its kinetic mass. This mechanism is reviewed and used to explain anomalous results of Collins, Edwards, Heller, and Sloan (hep-lat/9512026), which compared rest and kinetic masses of heavy-light mesons and quarkonia.
Distortion free pulse delay system using a pair of tunable white light cavities

Recently, a tunable bandwidth white light cavity (WLC) was demonstrated by using an anomalously dispersive intra-cavity medium to adjust a cavity linewidth without reducing the cavity buildup factor [G.S. Pati et al., Phys. Rev. Lett. 99, 133601 (2007)]. In this paper, we show theoretically how such a WLC can be used to realize a distortion-free delay system for a data pulse. The system consists of two WLCs placed in series. Once the pulse has passed through them, the fast-light media in both WLCs are deactivated, so that each of these now acts as a very high reflectivity mirror. The data pulse bounces around between these mirrors, undergoing negligible attenuation per pass. The trapped pulse can be released by activating the fast-light medium in either WLC. Numerical simulations show that such a system can far exceed the delay-bandwidth constraint encountered in a typical data buffer employing slow light. We also show that the pulse remains virtually undistorted during the process.
Ena/VASP proteins regulate cortical neuronal positioning.

Abstract Development of the multilayered cerebral cortex involves extensive regulated migration of neurons arising from the deeper germinative layers of the mammalian brain [1]. The anatomy and formation of the cortical layers has been well characterized; however, the underlying molecular mechanisms that control the migration and the final positioning of neurons within the cortex remain poorly understood [2, 3]. Here, we report evidence for a key role of Ena/VASP proteins, a protein family implicated in the spatial control of actin assembly [4] and previously shown to negatively regulate fibroblast cell speeds [5], in cortical development. Ena/VASP proteins are highly expressed in the developing cortical plate in cells bordering Reelin-expressing Cajal-Retzius cells and in the intermediate zone through which newly born cells migrate. Inhibition of Ena/VASP function through retroviral injections in utero led to aberrant placement of early-born pyramidal neurons in the superficial layers of both the embryonic and the postnatal cortex in a cell-autonomous fashion. The abnormally placed pyramidal neurons exhibited grossly normal morphology and polarity. Our results are consistent with a model in which Ena/VASP proteins function in vivo to control the position of neurons in the mouse neocortex.
On observing the absence of an atom

An atom is confined to a box in its ground state. An attempt is made to observe it in the left half of the box by scattering photons out of a photon wave packet passing through this half of the box. If no photons are scattered, the atom is missing. It is located on the right side of the box and its wave function is changed. The expectation value of the combined atom and photon energy is increased. For the other alternative, that the atom is found on the left side, the expectation value is decreased. By including both alternatives, it is shown that the mean energy is conserved.
Gold(I)-Catalyzed Dynamic Kinetic Enantioselective Intramolecular Hydroamination of Allenes

Treatment of benzyl 6-methyl-2,2-diphenyl-4,5-octadienyl carbamate (2a) with a catalytic 1:2 mixture of [(S)-3,5-t-Bu-4-MeO-MeOBIPHEP]Au2Cl2 [(S)-1] and AgClO4 (5 mol %) led to isolation of a 3.1:1 mixture of (R,Z)-3a and (R,E)-3a in 94% combined yield with 96 and 76% ee, respectively. Analyses of concentration versus time and/or conversion plots for the reaction of both racemic and enantiomerically enriched 2a with 1 were consistent with conversion of (R)-2a to (R,Z)-3a in the matched reaction manifold and conversion of (S)-2a to (R,E)-3a in the mismatched reaction manifold via the net anti-addition of Au and N across the internal CC bond of 2a.
Lidar measurements of tropospheric gases

Measurements of pollutants and water vapor in the troposphere using the differential absorption lidar (DIAL) technique are described. Measurements are made of sulfur dioxide in power plant plumes with a mobile DIAL system operated near 300 nm. Comparisons of sulfur dioxide concentrations determined with the DIAL system and in-stack monitors are found to be in agreement to within 18%. Vertical water vapor profiles with a ground-based lidar system are measured using the water vapor absorption line at 724.3 nm. Rawinsonde and DIAL water vapor profile data are shown to agree within 10% to an altitude of 2.5 km. Simulations are discussed for airborne DIAL measurements of sulfur dioxide, water vapor, and nitrogen dioxide.
Comparison of techniques for bonding VCSELS directly to ICs

This paper reports the successful bonding of 8 x 8 and 4 x 4 VCSEL arrays to Si CMOS and GaAs MESFET integrated circuits and to GaAs substrates. Three different bonding techniques are demonstrated and their electrical, optical and mechanical characteristics are compared. All three techniques remove the substrate from the VCSEL wafer, leaving individual VCSELs bonded directly to locations within the integrated circuit.
Contrast effects at grooved interfaces

Abstract This paper presents an investigation, based on computer simulations, of the Fresnel-fringe effects associated with surface grooving at grain boundaries. Three models are considered, corresponding to (a) a grooved surface without an interfacial film, (b) a non-grooved glassy interface, and (c) a combination of the two. It is shown that under certain circumstances the intersection of a grain boundary with a surface can cause contrast effects similar to those produced by the presence of a glassy layer within the grain boundary.
Financial Development and Income in North Africa

We explore the short-run dynamics and long-run relationship between income and financial development in Algeria, Egypt, and Morocco. We use co-integration and VECM models and four indicators of financial development. The empirical results indicate that there is a long-run relationship between income and each financial development indicator, except credit to the private sector in Algeria. On the other hand, Granger-causality test results indicate that the evidence on the direction of causality is mixed.
Origins of Cometary Materials

In this introductory presentation, material is categorized according to our state of knowledge: What do we know, what do we think we know but don’t know certainly, and what do we not know but often describe it as if it were a well-established fact about comets, their nuclei, their composition, and processes within comets and their nuclei. The material is presented not with the intend to criticize laboratory work simulating condition in comet nuclei, or observers analyzing their observations, nor modelers using data from both these sources to improve our understanding and make predictions. The intent is to provoke discussion and dialog between these groups to avoid overstating the results.
The structure of the Bern-Kosower integrand for the $N$-gluon amplitude

An ambiguity inherent in the partial integration procedure leading to the Bern-Kosower rules is fixed in a way which preserves the complete permutation symmetry in the scattering states. This leads to a canonical version of the Bern-Kosower representation for the one-loop $N$ -photon/gluon amplitudes, and to a natural decomposition of those amplitudes into permutation symmetric gauge invariant partial amplitudes. This decomposition exhibits a simple recursive structure.
Two experiments for the price of one? The role of the second oscillation maximum in long baseline neutrino experiments

We investigate the quantitative impact that data from the second oscillation maximum has on the performance of wide band beam neutrino oscillation experiments. We present results for the physics sensitivities to standard three flavor oscillation, as well as results for the sensitivity to non-standard interactions. The quantitative study is performed using an experimental setup similar to the Fermilab to DUSEL Long Baseline Neutrino Experiment (LBNE). We find that, with the single exception of sensitivity to the mass hierarchy, the second maximum plays only a marginal role due to the experimental difficulties to obtain a statistically significant and sufficiently background-free event sample at low energies. This conclusion is valid for both water Cerenkov and liquid argon detectors. Moreover, we confirm that non-standard neutrino interactions are very hard to distinguish experimentally from standard three-flavor effects and can lead to a considerable loss of sensitivity to θ 13, the mass hierarchy and CP violation.
Spy vs. Spy: Rumor Source Obfuscation

Anonymous messaging platforms, such as Secret, Yik Yak and Whisper, have emerged as important social media for sharing one's thoughts without the fear of being judged by friends, family, or the public. Further, such anonymous platforms are crucial in nations with authoritarian governments; the right to free expression and sometimes the personal safety of the author of the message depend on anonymity. Whether for fear of judgment or personal endangerment, it is crucial to keep anonymous the identity of the user who initially posted a sensitive message. In this paper, we consider an adversary who observes a snapshot of the spread of a message at a certain time. Recent advances in rumor source detection shows that the existing messaging protocols are vulnerable against such an adversary. We introduce a novel messaging protocol, which we call adaptive diffusion, and show that it spreads the messages fast and achieves a perfect obfuscation of the source when the underlying contact network is an infinite regular tree: all users with the message are nearly equally likely to have been the origin of the message. Experiments on a sampled Facebook network show that it effectively hides the location of the source even when the graph is finite, irregular and has cycles.
Development of Chiral Sulfoxide Ligands for Asymmetric Catalysis

Nitrogen-, phosphorus-, and oxygen-based ligands with chiral backbones have been the historic workhorses of asymmetric transition-metal-catalyzed reactions. On the contrary, sulfoxides containing chirality at the sulfur atom have mainly been used as chiral auxiliaries for diastereoselective reactions. Despite several distinct advantages over traditional ligand scaffolds, such as the proximity of the chiral information to the metal center and the ability to switch between S and O coordination, these compounds have only recently emerged as a versatile class of chiral ligands. In this Review, we detail the history of the development of chiral sulfoxide ligands for asymmetric catalysis. We also provide brief descriptions of metal–sulfoxide bonding and strategies for the synthesis of enantiopure sulfoxides. Finally, insights into the future development of this underutilized ligand class are discussed.
A non-canonical role for the C. elegans dosage compensation complex in growth and metabolic regulation downstream of TOR complex 2

The target of rapamycin complex 2 (TORC2) pathway is evolutionarily conserved and regulates cellular energetics, growth and metabolism. Loss of function of the essential TORC2 subunit Rictor (RICT-1) in Caenorhabditis elegans results in slow developmental rate, reduced brood size, small body size, increased fat mass and truncated lifespan. We performed a rict-1 suppressor RNAi screen of genes encoding proteins that possess the phosphorylation sequence of the AGC family kinase SGK, a key downstream effector of TORC2. Only RNAi to dpy-21 suppressed rict-1 slow developmental rate. DPY-21 functions canonically in the ten-protein dosage compensation complex (DCC) to downregulate the expression of X-linked genes only in hermaphroditic worms. However, we find that dpy-21 functions outside of its canonical role, as RNAi to dpy-21 suppresses TORC2 mutant developmental delay in rict-1 males and hermaphrodites. RNAi to dpy-21 normalized brood size and fat storage phenotypes in rict-1 mutants, but failed to restore normal body size and normal lifespan. Further dissection of the DCC via RNAi revealed that other complex members phenocopy the dpy-21 suppression of rict-1 , as did RNAi to the DCC effectors set-1 and set-4 , which methylate histone 4 on lysine 20 (H4K20). TORC2/ rict-1 animals show dysregulation of H4K20 mono- and tri-methyl silencing epigenetic marks, evidence of altered DCC, SET-1 and SET-4 activity. DPY-21 protein physically interacts with the protein kinase SGK-1, suggesting that TORC2 directly regulates the DCC. Together, the data suggest non-canonical, negative regulation of growth and reproduction by DPY-21 via DCC, SET-1 and SET-4 downstream of TORC2 in C. elegans .
Interfacial temperature measurements, high-speed visualization and finite-element simulations of droplet impact and evaporation on a solid surface

Abstract The objective of this work is to investigate the coupling of fluid dynamics, heat transfer and mass transfer during the impact and evaporation of droplets on a heated solid substrate. A laser-based thermoreflectance method is used to measure the temperature at the solid–liquid interface, with a time and space resolution of 100 μs and 20 μm, respectively. Isopropanol droplets with micro- and nanoliter volumes are considered. A finite-element model is used to simulate the transient fluid dynamics and heat transfer during the droplet deposition process, considering the dynamics of wetting as well as Laplace and Marangoni stresses on the liquid–gas boundary. For cases involving evaporation, the diffusion of vapor in the atmosphere is solved numerically, providing an exact boundary condition for the evaporative flux at the droplet–air interface. High-speed visualizations are performed to provide matching parameters for the wetting model used in the simulations. Numerical and experimental results are compared for the transient heat transfer and the fluid dynamics involved during the droplet deposition. Our results describe and explain temperature oscillations at the drop–substrate interface during the early stages of impact. For the first time, a full simulation of the impact and subsequent evaporation of a drop on a heated surface is performed, and excellent agreement is found with the experimental results. Our results also shed light on the influence of wetting on the heat transfer during evaporation.
Molecular-beam optothermal spectrum of the OH stretching band of methanol

Abstract The OH stretching fundamental band, ν1, of CH3OH has been recorded with sub-Doppler resolution using a molecular-beam optothermal spectrometer. The low effective temperature (∼6 K) of the molecular beam greatly reduces the spectral congestion from hot torsional vibrations and high rotational levels seen at room temperature, permitting an essentially complete assignment. a fit to a global hindered internal-rotor Hamiltonian, and identification of several perturbations and their likely perturbers. The observed linewidths are ∼15 MHz yielding an upper limit to any intramolecular vibrational relaxation rate.
Fast comparisons of circuit implementations

Digital designs can be mapped to different implementations using diverse approaches, with varying cost criteria. Post-processing transforms, such as transistor sizing, can significantly improve circuit performance by optimizing critical paths to meet timing specifications. However, most transistor sizing tools have high execution times, and the possible delay gains due to sizing, and the associated costs are not known prior to sizing. In this paper, we present two metrics for comparing different implementations-the minimum achievable delay and the cost of achieving a target delay-and show how these can be estimated without running a sizing tool. Using these fast and accurate performance estimators, a designer can determine the tradeoffs between multiple functionally identical implementations, and size only the selected implementation.
Low-bit-rate video coding using an adaptive partially connected motion model

Current video coding standards use simple translational motion models in predefined blocks to reduce temporal redundancy. Although this approach is quite effective, artifacts are produced by the simplistic motion model used and the fixed motion boundaries. The motion compensation algorithm presented in this paper uses a new partially connected motion model that removes the constraint of fixed block sizes and translational motion. The resulting motion field is guaranteed to be smooth and generally provides a good approximation to the true motion in the scene. The parameters of this motion model are optimized using a previously described algorithm that provides an efficient method for updating several motion vectors simultaneously. The complete motion estimation/compensation algorithm is incorporated into a transform based coder and compared to an existing H.263 codec. SInce the transmitted motion field provides a good approximation to the true motion in the scene, an additional advantage of the partially connected motion model is demonstrated by using the transmitted motion parameters to interpolate skipped frames at the receiver.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Reducing the dimensionality of linear quadratic control problems

Abstract In linear-quadratic control (LQC) problems with singularities in the control cost and/or the transition matrices, we derive a reduction of the dimension of the Riccati matrix, simplifying iteration and solution. Employing a novel transformation, we show that, under a certain rank condition, the matrix of optimal feedback coefficients is linear in the reduced Riccati matrix. For a substantive class of problems, our technique permits scalar iteration, leading to simple analytical solution.
Antiarrhythmic Activity of 3‐Amino‐3‐methyloxindoles

Abstract A series of 3‐amino‐3‐methyloxindoles was synthesized from indoles by modification of previously described procedures. All compounds showed activity against chloroform‐induced arrhythmias in mice. One member of the series, 3‐methyl‐3‐piperi‐dinooxindole, displayed activity equal to that of lidocaine while showing only one‐third the acute toxicity.
Optimum distortion-invariant filter for detecting a noisy distorted target in nonoverlapping background noise

An optimal distortion-invariant filter for detecting a distorted target in input noise is designed. The input noise consists of two sources of noise, overlapping additive noise and non-overlapping background noise. We obtain the filter function by statistically maximizing the peak-to-energy ratio criterion, which is defined as the ratio of the expected value squared of the output signal at the target location to the expected value of the average output energy. This results in a filter output with a well defined output peak at the target location and low output noise floor. The filter is designed to take into account the effects of both overlapping additive noise and non-overlapping background noise, the finite size of the input data, and the target distortion. Computer simulation results are provided to show the performance of the filter.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
New measurements of the rigidity of rocks at high pressure

Dynamical measurements of rigidity and velocity of distortional waves are presented for a few igneous rocks at pressures up to 9,000 kg/cm2 and for a group of schists, gneisses, and sedimentary rocks from the Boston area at pressures up to 4,000 kg/cm2. The effect of temperatures up to 150°C upon the velocity was determined at pressures of 4,300 kg/cm2 and 8,600 kg/cm2. The average temperature-coefficients of velocity between 30° and 150°C vary from −30 × 10−6 to to −160 × 10−6, with the acid rocks usually showing the smallest changes. The velocities of shear-waves in quartz-muscovite schists, in chlorite-schist, and in a compact argillite are found to be as high as or higher than the velocity in the average granite; the velocity in a dolomite is as high as in gabbro or diabase. The measurements are discussed with reference to the problem of identification of materials by seismic methods.
Direct synthesis of B-allyl and B-allenyldiisopinocampheylborane reagents using allyl or propargyl halides and indium metal under Barbier-type conditions.

We report the first one-pot process for the asymmetric addition of allyl, methallyl, and propargyl groups to aldehydes and ketones using B-chlorodiisopinocampheylborane (dDIP-Cl) and indium metal. Under Barbier-type conditions, indium metal was used to generate allyl- and allenylindium intermediates, and subsequent reaction with dDIP-Cl successfully promoted the transfer of these groups to boron forming the corresponding chiral borane reagents. The newly formed borane reagents were reacted with aldehydes and ketones to produce the corresponding alcohol products in high yields and up to excellent enantioselectivity (98% ee). This method produced excellent enantioenriched secondary homoallylic alcohols from the allylation and methallylation of benzaldehyde. Using this method, the methallylation and cinnamylation of ketones afforded the highest enantioselectivities, while the propargylation of both aldehydes and ketones provided low enantiomeric excesses. In addition, this procedure provided the first synthe...
Sliding mode control of a permanent magnet synchronous generator for variable speed wind energy conversion systems

Difficulties in achieving the maximum level of efficiency in power extraction from available wind resources warrant the collective attention of modern control and power systems engineers. A strong movement towards sustainable energy resources, and advances in control system methodologies, make previously unattainable levels of efficiency possible. One such promising method is sliding mode control. This control method, touted for its robustness given un-modeled dynamics present in the system, provides ideal characteristics for application in the control of permanent magnet synchronous generators employed in variable speed wind energy conversion systems. Application of this method for control using dynamic models of the d-axis and q-axis currents, as well as those of the high speed shaft rotational speed show a high level of efficiency in power extraction from a varying wind resource.
The enemy you can’t see: An investigation of the disruption of dark networks

Abstract We examine the optimal disruption of dark (covert and illegal) networks. Of central importance is that an interventionist will generally have incomplete information about the dark network's architecture. We derive the optimal disruption strategy in a stylized model of dark network intervention with incomplete information and show how it combines features of two types of disruption considered in the literature: random failure and targeted attacks. In particular, the optimal disruption strategy encourages greater risk as less of the architecture is observed. A laboratory experiment finds that subjects tasked with disrupting a dark network qualitatively mimic the theoretical predictions.
Ion beam sputtering of fluoropolymers

Etching and deposition of fluoropolymers are of considerable industrial interest for applications dealing with adhesion, chemical inertness, hydrophobicity, and dielectric properties. This paper describes ion beam sputter processing rates as well as pertinent characteristics of etched targets and films. An argon ion beam source was used to sputter etch and deposit the fluoropolymers PTFE, FEP, and CTFE. Ion beam energy, current density, and target temperature were varied to examine effects on etch and deposition rates. The ion etched fluoropolymers yield cone‐ or spirelike surface structures which vary depending upon the type of polymer, ion beam power density, etch time, and target temperature. Also presented are sputter target and film characteristics which were documented by spectral transmittance measurements, x‐ray diffraction, ESCA, and SEM photomicrographs.