cssi/SciSciGPT-SciSciNet huggingface dataset:
Yes Virginia, Diversification Is Still a Free Lunch

Recent financial market turbulence led many analysts to question the efficacy of diversification. This article uses changing correlations to show that diversification is still the tool that enhances risk-adjusted performance. Recent economic turbulence, however, makes it necessary to include more asset classes.
Halide promotion of the formation and carbonylation of μ3-imido ligands. Relevance to the halide promotion of nitroaromatic carbonylation catalysis

Abstract The individual reaction steps that are believed to occur during the catalytic carbonylation of nitroaromatics to form isocyanates, carbamates, amines, and ureas are reviewed with focus on stoichiometric organometallic reactions that model the proposed reaction steps. Especially emphasized are recent studies that show how halides dramatically promote both the formation and carbonylation of imido ligands. These results provide insight into the role that halides play in the known halide promoted Ru 3 (CO) 12 catalytic system for the formation of methyl N -phenylcarbamate from nitrobenzene, CO, and methanol [S. Cenini et al., J. Chem. Soc., Chem. Commun. 1984, 1286].
Synthesis, structure and physical properties of LnNi(Sn,Sb)3 (Ln=Pr, Nd, Sm, Gd, Tb)

Abstract Five new analogues of the β- CeNiSb 3 family have been synthesized and found to be Ln Ni(Sn,Sb) 3 and isostructural to the previously reported β -CeNiSb 3 . Ln Ni(Sn,Sb) 3 ( Ln =Pr, Nd, Sm, Gd, or Tb) crystallizes in the orthorhombic space group, Pbcm , with lattice parameters of a ∼12.9 A, b ∼6.1 A, c ∼12.0 A. The structure consists of layers of nearly square nets of X ( X =Sn/Sb) atoms and highly distorted Ni X 6 octahedra. Lanthanide atoms are located between layers of X and Ni X 6 octahedra. All analogues are metallic and experimental effective magnetic moments are in agreement with the respective Ln 3+ calculated moments.
Characterization of surface morphology in epitaxial growth

Abstract Simulated kinematic antiphase RHEED and HRLEED profiles are calculated along with the surface structure factor for a model of Fe Fe (100) deposition in order to clarify the interpretation of diffraction profiles in recent experiments on Fe Fe (100) growth. Similar calculations are also presented for a self-affine surface. While self-affine surfaces do not exhibit a characteristic RHEED peak, in the case of surfaces with a typical length scale the simulated RHEED profile exhibits a peak corresponding to the typical feature size, in agreement with recent experiments. The existence of this peak appears to be due to the large amount of shadowing present in low-angle RHEED, which limits the amount of destructive interference between layers. In contrast, simulated antiphase HRLEED patterns appear to approach an invariant profile for both self-affine and mound-like surface morphologies. For the case of small mounds, our results predict a HRLEED profile with a weak peak corresponding to the average terrace size which moves outward with increasing coverage, and eventually reaches an invariant form due to angle selection. The disappearance of the HRLEED peak for surfaces which have large mound structures is explained in terms of the antiphase condition and the range of variation of terrace sizes and provides an alternative explanation for the HRLEED results observed in Ref. [10].
Bound States and Impurity Averaging in Unconventional Superconductors

The question of anomalous transport due to a band of impurity states in unconventional superconductors is discussed. In general, the bound state energies are not in midgap, even in the unitarity limit. This implies that, generically, the states associated with impurities are broad resonances, not true bound states. There is no impurity band in the usual sense of the phrase. The wavefunctions of these resonances possess interesting anisotropies in real space, but this does not result in anomalous hopping between impurities. I conclude that the system of resonances produces no qualitative modifications to the T-matrix theory with impurity averaging which is normally used to treat the low-temperature transport of unconventional superconductors. However, users of this method often assume a density of states which is symmetric around the chemical potential. This is not normally the case. It is found that the non-crossing approximation is not valid in a strictly twodimensional system.
Computations of projectile Magnus effect at transonic velocities

Abstract : The Magnus effect has long been the nemesis of shell designers. Although very small in magnitude, on the order of 1/10th the normal force, this spin-induced side moment has a significant destabilizing effect on projectiles. A combined computational and experimental research program has been ongoing at BRL in recent years to develop a predictive capability for the Magnus effect in particular and for projectile aerodynamics in general. This effort has been very successful in the supersonic regime. The research to be reported in this paper is an extension of this effort into the transonic regime. Utilizing the time marching, thin-layer Navier-Stokes computational technique developed at NASA ames Research Center, solutions have been obtained for a spinning, 6-caliber long, ogive-cylinder-boattail shape at Mach = 0.91 and angle of attack = 2degrees. The computed results predict the correct development of the Magnus force along the body, and comparisons between the computation and experiment are very favorable. Details of the flow field solution such as turbulent boundary- layer velocity profiles and surface pressure distributions are presented. The components which contribute to the Magnus effect are determined and presented as a function of axial position. A complete set of aerodynamic coefficients have been determined from the flow field solutions. Those to be presented here and compared with experimental data include the normal force and Magnus force coefficients. The computations for this research effort were obtained both on a CDC 7600 computer and Cray 1S. (etc.)
Digital simulation of large-scale systems

Over the past decade systems analysis teams have repeatedly demonstrated the feasibility of using general purpose digital computers to simulate the operation of large-scale real-world systems. BAG, DECAP, INCA, STAGE, TEFORM and TEMPER are all representative examples. However, the process of developing and using these system simulations has not always been entirely satisfying to the ultimate users. The purpose of this paper is to examine the process of simulating systems, and so to suggest some causes of dissatisfaction and their remedies. Because of the diversity of usage, it seems to be important to define the key words to be used.
Complexity in quantum field theory and physics beyond the standard model

Abstract Complex quantum field theory (abbreviated c-QFT) is introduced in this paper as an alternative framework for the description of physics beyond the energy range of the standard model. The mathematics of c-QFT is based on fractal differential operators that generalize the momentum operators of conventional quantum field theory (QFT). The underlying premise of our approach is that c-QFT contains the right analytical tools for dealing with the asymptotic regime of QFT. Canonical quantization of c-QFT leads to the following findings: (i) the Fock space of c-QFT includes fractional numbers of particles and antiparticles per state, (ii) c-QFT represents a generalization of topological field theory and (iii) classical limit of c-QFT is equivalent to field theory in curved space–time. The first finding provides a field-theoretic motivation for the transfinite discretization approach of El-Naschie’s e(∞) theory. The second and third findings suggest the dynamic unification of boson and fermion fields as particles with fractional spin, as well as the close connection between spin and space-time topology beyond the conventional physics of the standard model.
Optimal deadline scheduling with commitment

We consider an online preemptive scheduling problem where jobs with deadlines arrive sporadically. A commitment requirement is imposed such that the scheduler has to either accept or decline a job immediately upon arrival. The scheduler's decision to accept an arriving job constitutes a contract with the customer; if the accepted job is not completed by its deadline as promised, the scheduler loses the value of the corresponding job and has to pay an additional penalty depending on the amount of unfinished workload. The objective of the online scheduler is to maximize the overall profit, i.e., the total value of the admitted jobs completed before their deadlines less the penalty paid for the admitted jobs that miss their deadlines. We show that the maximum competitive ratio is 3 − √2 and propose a simple online algorithm to achieve this competitive ratio. The optimal scheduling includes a threshold admission and a greedy scheduling policies. The proposed algorithm has direct applications to the charging of plug-in hybrid electrical vehicles (PHEV) at garages or parking lots.
Three-dimensional turbulent flow code calculations of hot gas ingestion

The development of short takeoff, vertical landing (STOVL) aircraft has historically been an "experiencebased" endeavor. In this study, a three-dimensional turbulent flow computational fluid dynamics (CFD) code was used to calculate the hot gas environment around a STOVL aircraft operating in ground proximity. Preliminary calculations are reported herein for a typical STOVL aircraft configuration to identify key features of the flowfield and to demonstrate the capability of a current three-dimensional CFD code to calculate the temperature of the gases ingested at the engine inlet for typical flow and geometric conditions.
Optimal bank portfolio choice under fixed-rate deposit insurance

This paper analyzes the investment decisions of insured banks under fixed-rate deposit insurance. The model takes into account the charter value and allows banks to dynamically revise their asset portfolios. Trade-offs exist between preserving the charter and exploiting deposit insurance. The optimal bank portfolio problem is solved analytically for a constant charter value. In any audit period, banks maximize their risk exposure before some critical time and act cautiously thereafter. The corresponding deposit insurance is shown to be a put option that matures at this critical time rather than at the audit date.
Noise Maps for Acoustically Sensitive Navigation

More and more robotic applications are equipping robots with microphones to improve the sensory information available to them. However, in most applications the auditory task is very low-level, only processing data and providing auditory event information to higher-level navigation routines. If the robot, and therefore the microphone, ends up in a bad acoustic location, then the results from that sensor will remain noisy and potentially useless for accomplishing the required task. To solve this problem, there are at least two possible solutions. The first is to provide bigger and more complex filters, which is the traditional signal processing approach. An alternative solution is to move the robot in concert with providing better audition. In this work, the second approach is followed by introducing noise maps as a tool for acoustically sensitive navigation. A noise map is a guide to noise in the environment, pinpointing locations which would most likely interfere with auditory sensing. A traditional noise map, in an acoustic sense, is a graphical display of the average sound pressure level at any given location. An area with high sound pressure level corresponds to high ambient noise that could interfere with an auditory application. Such maps can be either created by hand, or by allowing the robot to first explore the environment. Converted into a potential field, a noise map then becomes a useful tool for reducing the interference from ambient noise. Preliminary results with a real robot on the creation and use of noise maps are presented.
Charged excitons of composite fermions in the fractional quantum Hall effect

Abstract Charged excitons of composite fermions (CFs) are considered in the fractional quantum Hall effect. Energies of the charged CF excitons are computed at ν =1/3 as a function of the size of exciton. Our study suggests that the charged CF exciton with the size of a roton is lower in energy than the unbound state of a neutral roton and a lone charge. Therefore, we propose that the lowest-energy excitation of the fractional quantum Hall effect is in fact due to the charged excitons of composite fermions composed of two CF-particles and one CF-hole. The experimental relevance of the charged excitons of composite fermions is explored in the context of the resonant inelastic light scattering experiments.
PHYSICAL CONDITIONS IN THE INNER NARROW-LINE REGION OF THE SEYFERT 2 GALAXY MARKARIAN 573*

We have examined the physical conditions within a bright emission-line knot in the inner narrow-line region (NLR) of the Seyfert 2 galaxy Mrk 573 using optical spectra and photoionization models. The spectra were obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph, through the 02 ? 520 slit, at a position angle of ?712, with the G430L and G750M gratings. Comparing the spatial emission-line profiles, we found [Fe?X] ? 6734 barely resolved, [O III] ?5007 centrally peaked, but broader than [Fe?X], and [O II] ?3727 the most extended. Spectra of the central knot were extracted from a region 11 in extent, corresponding to the full width at zero intensity in the cross-dispersion direction, of the knot. The spectra reveal that [Fe?X] is broader in velocity width and blueshifted compared with lines from less ionized species. Our estimate of the bolometric luminosity indicates that the active galactic nucleus (AGN) is radiating at or above its Eddington luminosity, which is consistent with its identification as a hidden Narrow-Line Seyfert 1. We were able to successfully match the observed emission-line ratios with a three-component photoionization model. Two components, one to account for the [O III] emission and another in which the [Fe?X] arises, are directly ionized by the AGN, while [O II] forms in a third component, which is ionized by a heavily absorbed continuum. Based on our assumed ionizing continuum and the model parameters, we determined that the two directly ionized components are ~55 pc from the AGN. We have found similar radial distances for the central knots in the Seyfert 2 galaxies Mrk 3 and NGC 1068, but much smaller radial distances for the inner NLR in the Seyfert 1 galaxies NGC 4151 and NGC 5548. Although in general agreement with the unified model, these results suggest that the obscuring material in Seyfert galaxies extends out to at least tens of parsecs from the AGN.
A Comparative Study Of Tolerance Analysis Methods

This paper reviews four major methods for tolerance analysis and compares them. The methods discussed are (1) 1D tolerance charts, (2) variational analysis based on Monte Carlo simulation, (3) vector loop (or kinematic) based analysis, and (4) ASU T-Maps© based tolerance analysis. Tolerance charts deal with tolerance analysis in one direction at a time and ignore possible contributions from the other directions. Manual charting is tedious and error-prone, hence attempts have been made for automation. Monte Carlo simulation based tolerance analysis is based on parametric solid modeling; its inherent drawback is that simulation results highly depend on the user-defined modeling scheme, and its inability to obey all Y14.5 rules. The vector loop method uses kinematic joints to model assembly constraints. It is also not fully consistent with Y14.5 standard. ASU T-Maps based tolerance analysis method can model geometric tolerances and their interaction in truly 3-dimensional context. It is completely consistent with Y14.5 standard but its use by designers may be quite challenging. T-Maps based tolerance analysis is still under development. Despite the shortcomings of each of these tolerance analysis methods, each may be used to provide reasonable results under certain circumstances. No guidelines exist for such a purpose. Through a comprehensive comparison of these methods, this paper will develop some guidelines for selecting the best method to use for a given tolerance accumulation problem.Copyright © 2004 by ASME
Observations regarding eschenmoser sulfide contractions of β-oxygenated thiolactams

Abstract Application of an Eschenmoser sulfide contraction to a thiolactam bearing a β-acyloxy group was complicated by a competitive β-elimination reaction. Changing the β-substituent to an alkoxy group retarded the rate of elimination such that sulfide contraction products could be obtained.
The Drosophila of single-molecule magnetism: [Mn12O12(O2CR)16(H2O)4]

Single-molecule magnets (SMMs) are individual molecules that can function as nanoscale magnetic particles. The [Mn12O12(O2CR)16(H2O)4] (Mn12; R = Me, Et, etc.) family of SMMs was the first one discovered; it is also the one whose study has provided the majority of current knowledge on this interesting magnetic phenomenon, prompting its description here as the Drosophila of the field. This tutorial review will survey the various chemical studies that have been carried out to date on this family. This will include a discussion of methods that have been developed for their structural and redox transformation, and the effect of the latter on the magnetic and SMM properties.
Online Hierarchical Cooperative Caching

We address a hierarchical generalization of the well-known disk paging problem. In the hierarchical cooperative caching problem, a set of n machines residing in an ultrametric space cooperate with one another to satisfy a sequence of read requests to a collection of read-only files. A seminal result in the area of competitive analysis states that the "least recently used" (LRU) paging algorithm is constant-competitive if it is given a constant-factor blowup in capacity over the offline algorithm. Does such a constant-competitive deterministic algorithm, with a constant-factor blowup in the machine capacities, exist for the hierarchical cooperative caching problem? In this paper we present a deterministic hierarchical generalization of LRU that is constant-competitive when the capacity blowup is linear in d, the depth of the cache hierarchy. Furthermore, we exhibit an infinite family of depth-d hierarchies such that any randomized hierarchical cooperative caching algorithm with capacity blowup b has competitive ratio Ω(log(d/b)) against an oblivious adversary. Thus, our upper and lower bounds imply a tight bound of Θ(d) on the capacity blowup required to achieve constant competitiveness.
Effects Of Scattering On X-Ray Imaging

Very high spatial frequency irregularities with small amplitude on a polished surface that usually cause wide-angle scattering in conventional optical systems produce narrow-angle scattering in x-ray systems. Yet, even this small amount of scattering degrades the imaging properties of x-ray systems. Statistical surface perturbations and their effects on x-ray image quality are discussed. A model of surface roughness that is reasonably consistent with surface profile measurements and visible scatter profile measurement is discussed. This model is then used to evaluate the image profile of an x-ray system.
The evolution of reciprocity in sizable groups

Recently, several authors have investigated the evolution of reciprocal altruism using the repeated prisoner's dilemma game. These models suggest that natural selection is likely to favor behavioral strategies leading to reciprocal cooperation when pairs of individuals interact repeatedly in potentially cooperative situations. Using the repeated n-person prisoner's dilemma game, we consider whether reciprocal altruism is also likely to evolve when social interactions involve more individuals. We show that the conditions that allow the evolution of reciprocal cooperation become extremely restrictive as group size increases.
Suboptimal command generation for control moment gyroscopes and feedback control of spacecraft

This paper presents a suboptimal gimbal-angle command generation technique and a Lyapunov-based tracking control law for control moment gyroscopes. The formulation of the open-loop maneuver problem exploits the principle of conservation of angular momentum. This allows for a reduction in the dimensionality of the problem— only the kinematics need be considered. The gimbal rates are parametrized as polynomial functions of time, and the parameters are optimized. The objective function of the optimization is the singularity measure. The optimal null motion used is determined after computing the open-loop gimbal-rate profiles. A feedback strategy is used to track the open-loop reference attitude and angular velocity profiles. Null motion is also used to allow the closedloop gimbal angles to follow the open-loop gimbal-angle histories. This procedure avoids neighboring singularities and also provides repeatability. Simulation results are presented for rest-to-rest maneuvers using a model of a ground-based test article. The results show that a wide domain of singularity-free operation around the reference solution can be provided with this approach.
Online comparison shopping behavior of travel consumers.

This article examines the extent of pre-purchase comparison search activity, in terms of comparison search duration and dispersion (number of alternative vendors examined) and its impact on purchase propensity for flight, car rental and hotel reservations. Click stream data and transactions from the Comscore panel of travelers between March and September 2008 are used to examine our hypotheses. Results show that comparison dispersion has an inverted-U relationship on purchase probability for flight and rental cars but does not significantly impact hotel purchases. Further, comparison search dispersion and duration differ for households of different sizes and income. These findings can help travel website managers develop appropriate online search marketing strategies to increase purchase conversion among different demographic segments.
Enantioselective Addition of Thioacetic Acid to Nitroalkenes via N-Sulfinyl Urea Organocatalysis

The highly enantioselective addition of thioacetic acid to nitroalkenes using a new sulfinyl urea organocatalyst is described. The addition of thioacetic acid proceeds in high yields and enantioselectivities for a variety of aromatic and aliphatic nitroalkene substrates. This new method is useful for preparing chiral 1,2-aminothiol derivatives, as demonstrated by the first enantioselective synthesis of the clinically used antifungal drug sulconazole.
A G1-like Globular Cluster in NGC 1023

The structure of a very bright (MV = -10.9) globular cluster in NGC 1023 is analyzed on two sets of images taken with the Hubble Space Telescope. From careful modeling of King profile fits to the cluster image, a core radius of rc = 0.55 ± 0.1 pc, effective radius Re = 3.7 ± 0.3 pc, and a central surface brightness of μ0(V) = 12.9 ± 0.5 mag arcsec-2 are derived. This makes the cluster much more compact than ω Cen, but very similar to the brightest globular cluster in M31, G1 (= Mayall II). The cluster in NGC 1023 appears to be very highly flattened with an ellipticity of ≈ 0.37, even higher than for ω Cen and G1, and similar to the most flattened clusters in the Large Magellanic Cloud.
Single photon frequency up-conversion and its applications

Abstract Optical frequency up-conversion is a technique, based on sum frequency generation in a non-linear optical medium, in which signal light from one frequency (wavelength) is converted to another frequency. By using this technique, near infrared light can be converted to light in the visible or near visible range and therefore detected by commercially available visible detectors with high efficiency and low noise. The National Institute of Standards and Technology (NIST) has adapted the frequency up-conversion technique to develop highly efficient and sensitive single photon detectors and a spectrometer for use at telecommunication wavelengths. The NIST team used these single photon up-conversion detectors and spectrometer in a variety of pioneering research projects including the implementation of a quantum key distribution system; the demonstration of a detector with a temporal resolution beyond the jitter limitation of commercial single photon detectors; the characterization of an entangled photon pair source, including a direct spectrum measurement for photons generated in spontaneous parametric down-conversion; the characterization of single photons from quantum dots including the measurement of carrier lifetime with escalated high accuracy and the demonstration of the converted quantum dot photons preserving their non-classical features; the observation of 2nd, 3rd and 4th order temporal correlations of near infrared single photons from coherent and pseudo-thermal sources following frequency up-conversion; a study on the time-resolving measurement capability of the detectors using a short pulse pump and; evaluating the modulation of a single photon wave packet for better interfacing of independent sources. In this article, we will present an overview of the frequency up-conversion technique, introduce its applications in quantum information systems and discuss its unique features and prospects for the future.
Impact of a global warming on biospheric sources of methane and its climatic consequences

Most of atmospheric methane originates by bacterial processes in anaerobic environments withinthe soil which are found to become more productive with increases in ambient temperature. Awarming of climate, due to increasing levels of industrial gases resulting from fossil fuel burning,is thus likely to increase methane abundance within the atmosphere. This may lead to furtherheating of the atmosphere, since both methane and ozone (which is generated in the tropospherefrom reactions of methane) have greenhouse effects. We have explored this feedback mechanismusing a coupled climate-chemical model of the troposphere, by calculating the impact of thepredicted global warming due to iricreased emissions of carbon dioxide and other industrial gaseson the biospheric sources of methane. Although we find this climate feedback to be, by itself,relatively minor, it can produce measurable increases in atmospheric CH 4 , concentration, aquantity which should additionally increase as a consequence of increasing anthropogenicemissions of CO and CH 4 , itself. It would thus seem useful to carefully monitor futureatmospheric CH 4 , concentrations. DOI: 10.1111/j.1600-0889.1983.tb00001.x
Foreign currency debt in emerging markets: firm-level evidence from Mexico ☆

Abstract Using a database of over 500 Mexican companies, we examine the determinants of the share of foreign-currency denominated debt in total debt, finding that it is positively correlated with imports, exports, and the size of the firm.
Lipid-like nanomaterials for simultaneous gene expression and silencing in vivo.

New lipid-like nanomaterials were developed to simultaneously regulate expression of multiple genes. Self-assembled nanoparticles are capable of efficiently encapsulating pDNA and siRNA. These nanoparticles were shown to induce simultaneous gene expression and silencing both in vitro and in vivo.
Tau Appearance In Atmospheric Neutrino Interactions

Abstract If the correct interpretation of the Super-Kamiokande atmospheric neutrino data is ν μ → ν τ oscillation, the contained data sample should already have more than 10 τ appearance events. We study the challenging task of detecting the τ , focussing on the decay chain τ ± → ρ ± → π ± π 0 in events with quasi-elastic τ production. The background level, which is currently quite uncertain because of a lack of relevant neutral current data, can be measured by the near detector in the K2K experiment. Our estimates of the background suggest that it may be possible to detect τ appearance in Super-Kamiokande with 5–10 years of running.
At-most-once semantics in asynchronous shared memory

This paper investigates the feasibility of implementing at-most-once access semantics in a model where a collection of actions is to be performed by failure-prone, asynchronous shared-memory processes. We introduce the At-Most-Once problem for performing a set of n jobs using m processors, and we define the notion of efficiency for such protocols, called effectiveness, that allows the classification of algorithms solving the problem. The effectiveness for an at-most-once implementation is the number of jobs safely completed by the implementation, expressed as a function of the number of jobs n, the number of processes m, and the number of process crashes f. We prove a lower bound of n--f on the effectiveness of any algorithm. We then present two process solutions that offer a trade off between work and space complexity. Finally, we generalize a two-process solution for the multi-process setting using a hierarchical algorithm that achieves effectiveness of n--log m†o(n), coming reasonably close, asymptotically, to the corresponding lower bound.
Generating fuzzy rules by learning from examples

A general method is developed to generate fuzzy rules from numerical data. The method consists of five steps: divide the input and output spaces of the given numerical data into fuzzy regions; generate fuzzy rules from the given data; assign a degree of each of the generated rules for the purpose of resolving conflicts among the generated rules; create a combined fuzzy rule base based on both the generated rules and linguistic rules of human experts; and determine a mapping from input space to output space based on the combined fuzzy rule base using a defuzzifying procedure. The mapping is proved to be capable of approximating any real continuous function on a compact set to arbitrary accuracy. Applications to truck backer-upper control and time series prediction problems are presented. >
Stochastic Loewner evolution in multiply connected domains

Abstract We construct radial stochastic Loewner evolution in multiply connected domains, choosing the unit disk with concentric circular slits as a family of standard domains. The natural driving function or input is a diffusion on the associated moduli space. The diffusion stops when it reaches the boundary of the moduli space. We show that for this driving function the family of random growing compacts has a phase transition for κ = 4 and κ = 8 , and that it satisfies locality for κ = 6 . To cite this article: R.O. Bauer, R.M. Friedrich, C. R. Acad. Sci. Paris, Ser. I 339 (2004).
Intricate Knots in Proteins: Function and Evolution

Our investigation of knotted structures in the Protein Data Bank reveals the most complicated knot discovered to date. We suggest that the occurrence of this knot in a human ubiquitin hydrolase might be related to the role of the enzyme in protein degradation. While knots are usually preserved among homologues, we also identify an exception in a transcarbamylase. This allows us to exemplify the function of knots in proteins and to suggest how they may have been created.
Ruthenium on chitosan: a recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides

Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride, and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which proceeds exclusively in aqueous medium under neutral conditions.
Discrete torsion and shift orbifolds

Abstract In this paper we make two observations related to discrete torsion. First, we observe that an old obscure degree of freedom (momentum/translation shifts) in (symmetric) string orbifolds is related to discrete torsion. We point out how our previous derivation of discrete torsion from orbifold group actions on B fields includes these momentum lattice shift phases, and discuss how they are realized in terms of orbifold group actions on D-branes. Second, we describe the M-theory dual of IIA discrete torsion. We show that IIA discrete torsion is encoded in analogues of the shift orbifolds above for the M-theory C field.
Experiments with a program timing tool based on source-level timing schema

Analytic methods are employed at the source-language level, using formal timing schema that include control costs, handle interferences such as interrupts, and produce guaranteed best- and worst-case bounds. The timing tool computes the deterministic execution times for programs that are written in a subset of C and run on a bare machine. Two versions of the tool were written, using two granularity extremes for the atomic elements of the timing schema. All overview of the tool is given, timing schema and code prediction are discussed, and machine analysis and timing tool design are examined. Experimental and validation results are reported. It was found that all the predicted times are consistent, and most are safe. Some predictions are fairly tight, while others are a little loose. There are clear technical reasons that explain the differences between measured and predicted times, and technical solutions that should minimize these differences within the timing schema framework are seen. >
Analytic calculation of properties of holographic superconductors

We calculate analytically properties of holographic superconductors in the probe limit. We analyze the range 1/2 3/2. We also obtain the frequency dependence of the conductivity by solving analytically the wave equation of electromagnetic perturbations. We show that the real part of the DC conductivity behaves as e −Δg/T and estimate the gap Δ g analytically. Our results are in good agreement with numerical results.
Magnetic monopoles as the highest energy cosmic ray primaries

Abstract We suggest that the highest energy ≳ 10 20 eV cosmic ray primaries may be relativistic magnetic monopoles. Motivations for this hypothesis are that conventional primaries are problematic, while monopoles are naturally accelerated to E ∼ 10 20 eV by galactic magnetic fields. By matching the cosmic monopole production mechanism to the observed highest energy cosmic ray flux we estimate the monopole mass to be ≲ 10 10 GeV.
Radiative energy and momentum transfer for various spherical shapes: A single sphere, a bubble, a spherical shell, and a coated sphere

We use fluctuational electrodynamics to determine spectral emissivity and van der Waals contribution to surface energy for various spherical shapes, such as a sphere, a bubble, a spherical shell, and a coated sphere, in a homogeneous and isotropic medium. The dyadic Green's function formalism of radiative energy and fluctuation-induced van der Waals stress for different spherical configurations has been developed. We show (1) emission spectra of micro- and nano-sized single and coated spheres display several emissivity sharp peaks as the size of object reduces and (2) surface energy becomes size dependent due to van der Waals phenomena when size of object is reduced to a nanoscopic length scale.
Trapped fermions across a Feshbach resonance with population imbalance

We investigate the phase separation of resonantly interacting fermions in a trap with imbalanced spin populations, both at zero and at finite temperatures. We directly minimize the thermodynamical potential under the local density approximation instead of using the gap equation, as the latter may give unstable solutions. On the BEC side of the resonance, one may cross three different phases from the trap center to the edge; while on the BCS side or at resonance, typically only two phases show up. We compare our results with the recent experiment, and the agreement is remarkable.
Fate, Transport, and Biodegradation of Natural Estrogens in the Environment and Engineered Systems

Natural steroidal estrogen hormones, e.g., estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-estradiol (17α), are released by humans and livestock in the environment and are the most potent endocrine disrupters even at nanogram per liter levels. Published studies broadly conclude that conventional wastewater treatment is efficient in the removal of 17β-estradiol (85−99%), but estrone removal is relatively poor (25−80%). The removal occurs mainly through sorption by sludge and subsequent biodegradation. The long solids retention time in wastewater treatment systems enhances estrogen removal due to longer exposure and the presence of a diverse microbial community, particularly nitrifiers. In spite of the treatment, the effluent from conventional biological wastewater treatment systems still contains estrogenic compounds at a level that may cause disruption of endocrine systems in some species. Advanced wastewater treatment systems such as membrane processes remove the estrogen compounds mainly through...
Synthesis of diketopiperazine-based carboline homodimers and in vitro growth inhibition of human carcinomas.

Abstract Starting from d - or l -tryptophan, we have synthesized and characterized six compounds 2.29 – 2.31a and b that belong to a class of nitrogen heterocycles: the carboline-based homodimers. Each individual homodimer features a 1,3- trans relationship on each side of the central diketopiperazine core, but differs in absolute stereochemistry and also in substitution on the 4′ and 4″ oxygens (–Bn, –CH 3 , or –H). The in vitro cytotoxicity of the six compounds was evaluated by measuring the growth inhibition in NCI–H520 and PC-3 human carcinoma cells. Phenol 2.30a inhibited cancer cell growth approximately three times better than its enantiomer 2.30b and possessed a GI 50 comparable to the clinically used agent etoposide in both cell lines. We have concluded that both the stereochemistry imparted by l -tryptophan and the presence of hydroxy substituents at the 4′ and 4″ positions are necessary to generate cytotoxic properties in the homodimer class. We are now employing 2.30a as a new lead compound in our efforts to discover improved indole-based cancer chemotherapeutics.
TURBULENCE AND PARTICLE HEATING IN ADVECTION-DOMINATED ACCRETION FLOWS

We extend and reconcile recent work on turbulence and particle heating in advection-dominated acc- retion —ows. For approximately equipartition magnetic —elds, the turbulence primarily heats the elec- trons. For weaker magnetic —elds, the protons are primarily heated. The division between electron and proton heating occurs between b D 5 and b D 100 (b is the ratio of gas to magnetic pressure), depending on unknown details of how waves are converted into whistlers on scales of the proton Larmor Alfvec n radius. We also discuss the possibility that magnetic reconnection could be a signi—cant source of elec- tron heating. Subject headings: accretion, accretion disksMHDplasmasturbulence
THE DISK POPULATION OF THE CHAMAELEON I STAR-FORMING REGION

We present a census of circumstellar disks in the Chamaeleon I star-forming region. Using the Infrared Array Camera and the Multiband Imaging Photometer on board the Spitzer Space Telescope, we have obtained images of Chamaeleon I at 3.6, 4.5, 5.8, 8.0, and 24 ?m. To search for new disk-bearing members of the cluster, we have performed spectroscopy on objects that have red colors in these data. Through this work, we have discovered four new members of Chamaeleon I with spectral types of M4, M6, M7.5, and L0. The first three objects are highly embedded ( -->AJ ~ 5) and reside near known protostars, indicating that they may be among the youngest low-mass sources in the cluster ( -->? M 1 M? is significantly higher in Chamaeleon I than in IC 348 (65% vs. 20%), indicating longer disk lifetimes in Chamaeleon I for this mass range. Thus, low-density star-forming regions like Chamaeleon I may offer more time for planet formation around solar-type stars than denser clusters.
Modeling of a Hollow-Cone Liquid Spray Including Droplet Collisions

A spray model is used to determine the characteristics of a hollow-cone water spray injected from a pressure jet-swirl atomizer into uniform airflow traveling through a vertical wind tunnel. The model simulates droplets stochastically and accounts for "drop-drop" effects by permitting droplet collisions that result in coalescence or breakup. This investigation's objective is to study the model's droplet tracking capabilities with special emphasis placed on the effects of droplet collisions. It is concluded that the collision model's results for droplet velocities agree well with experimental measurements but that droplet trajectory angles are overpredicted. Droplet sizes that are underpredicted by the model when collisions are neglected are still underpredicted when collisions are included although some improvement is noted.
Team-Triggered Coordination for Real-Time Control of Networked Cyber-Physical Systems

This paper studies the real-time implementation of distributed controllers on networked cyber-physical systems. We build on the strengths of event- and self-triggered control to synthesize a unified approach, termed team-triggered, where agents make promises to one another about their future states and are responsible for warning each other if they later decide to break them. The information provided by these promises allows individual agents to autonomously schedule information requests in the future and sets the basis for maintaining desired levels of performance at lower implementation cost. We establish provably correct guarantees for the distributed strategies that result from the proposed approach and examine their robustness against delays, packet drops, and communication noise. The results are illustrated in simulations of a multi-agent formation control problem.
Prospective Changes in Attributions of Self-Blame and Social Reactions to Women's Disclosures of Adult Sexual Assault

The present longitudinal study examined relationships between self-blame attributions and social reactions to disclosure in a community sample of adult sexual assault victims ( N = 555). Cross-lagged panel analyses showed that neither characterological self-blame nor behavioral self-blame related to negative social reactions over the 1-year follow-up period. In contrast, characterological but not behavioral self-blame predicted fewer positive reactions over time. Although positive reactions did not reduce self-blame, negative reactions led to greater characterological, but not behavioral, self-blame during the course of the study. Thus, relationships between self-blame and social reactions were not reciprocal but rather quite complex. The effects of victims’ coping strategies and sexual revictimization were also assessed.
Historical changes in lake ice-out dates as indicators of climate change in New England, 1850-2000

Various studies have shown that changes over time in spring ice-out dates can be used as indicators of climate change. Ice-out dates from 29 lakes in New England (USA) with 64 to 163 years of record were assembled and analysed for this study. Ice-out dates have become significantly earlier in New England since the 1800s. Changes in ice-out dates between 1850 and 2000 were 9 days and 16 days in the northern/mountainous and southern regions of New England respectively. The changes in the ice-out data over time were very consistent within each of the two regions of New England, and more consistent than four air-temperature records in each region. The ice-out dates of the two regions had a different response to changes in air temperature. The inferred late winter–early spring air-temperature warming in both regions of New England since 1850, based on linear regression analysis, was about 1.5°C. Published in 2002 by John Wiley & Sons, Ltd.
The pricing of discretionary accruals

Abstract This paper examines if the stock market prices discretionary accruals. Evidence reveals that, on average, the market attaches value to discretionary accruals. This evidence is consistent with two alternative scenarios: (1) managerial discretion improves the ability of earnings to reflect economic value, and (2) discretionary accruals are opportunistic and value-irrelevant but priced by an inefficient market. Further evidence is consistent with the former explanation. There is evidence of pervasive income smoothing, which improves the persistence and predictability of reported earnings. There is also evidence that discretionary accruals predict future profitability and dividend changes. Despite several sensitivity checks, measurement error in the discretionary accruals proxy is an alternative explanation for the results.
Enantioenriched N-(2-chloroalkyl)-3-acetoxypiperidines as potential cholinotoxic agents. Synthesis and preliminary evidence for spirocyclic aziridinium formation

Abstract The syntheses of six enantioenriched analogs representing cyclic forms of acetylcholine are reported. (S)- and (R)-N-(2-chloroethyl)-3-acetoxypiperidine and (R,R)-, (R,S)-, (S,R)-, and (S,S)-N-(2-chloropropyl)-3-acetoxypiperidine have been synthesized from (R)- or (S)-3-hydroxypiperidine in five steps. (R)- and (S)-3-hydroxypiperidine were accessed via parallel stereospecific routes from d- and 1-glutamic acid, and through fractional recrystallization of diastereomeric tartranilic acid salts. ( (S)-N-(2-Chloroethyl)-3-acetoxypiperidine was reacted with silver perchlorate to form a spirocyclic aziridinium analog of acetylcholine as evidenced by a characteristic 1H NMR shift for the aziridinium methylene groups.
Bad news and bank performance during the 2008 financial crisis

The article investigates market reaction to negative reports published by analysts and auditors for a sample of investment, commercial and savings banks during the 2008 financial crisis and compares the results to noncrisis periods. The results show that during 2008, analysts’ downgrades and underperformance reports resulted in stronger negative returns than during noncrisis periods and that investment banks experienced the worst stock price declines. The market reaction to auditors’ issues and going concern flags is different during the crisis as well. In noncrisis periods no reaction to auditors’ bad news is reported, while during the crisis there is a negative and significant reaction for investment banks only. Overall, the type of bank, investment versus commercial, significantly contributes to explaining the variability in returns during the financial crisis.
Biomass torrefaction: modeling of reaction thermochemistry.

Abstract Based on the evolution of volatile and solid products predicted by a previous model for willow torrefaction ( Bates and Ghoniem, 2012 ) a thermochemical model has been developed to describe their thermal, chemical, and physical properties as well as the rates of heat release. The first stage of torrefaction, associated with hemicellulose decomposition, is exothermic releasing between 40 and 280 kJ/kginitial. The second stage is associated with the decomposition of the remaining lignocellulosic components, completes over a longer period, and is predicted to be either endothermic or exothermic depending on the temperature and assumed solid properties. Cumulative heat release increases with the degree of torrefaction quantified by the mass loss. The rate of mass loss and rate of heat release increase with higher temperatures. The higher heating value of volatiles produced during torrefaction was estimated to be between 4.4 and 16 MJ/kg increasing with the level of mass loss.