cssi/SciSciGPT-SciSciNet huggingface dataset:
Reductive amine deallyl- and debenzylation with alkali metal in Silica Gel (M-SG)

Alkali metals in silica gel (the M-SG materials) are effective reagents for reductive deallylation, debenzylation, debenzhydrylation, and detritylation of amines. As such, these reagents provide a convenient alternative to traditional metal ammonia solutions for this class of deprotections.
Phase diagram of imperfect ferromagnetic/antiferromagnetic bilayers

Abstract The phase diagram for ferromagnetic/antiferromagnetic bilayers with imperfect interfaces is calculated, using an Ising spin-1/2 model which is solved numerically in the mean field approximation for finite temperatures. We identify three stable phases: (i) domains in the ferromagnet, (ii) domains in the antiferromagnet and (iii) domain walls near the interfaces with homogeneous order within the layers. Phase transitions between these phases occur as a function of temperature, relative film thicknesses and step density.
Configuration space integrals and Taylor towers for spaces of knots

Abstract We describe Taylor towers for spaces of knots arising from Goodwillie–Weiss calculus of the embedding functor and extend the configuration space integrals of Bott and Taubes from spaces of knots to the stages of the towers. We show that certain combinations of integrals, indexed by trivalent diagrams, yield cohomology classes of the stages of the tower, just as they do for ordinary knots.
Free energy of a hot gluon plasma and hard-thermal-loop resummation

In this talk I briefly discuss the thermodynamics of the quark-gluon plasma The calculation of the free energy of a hot gluon plasma to leading order in hard-thermal-loop perturbation theory is outlined. The HTL free energy is compared with the weak-coupling expansion and lattice results.
SUPERMASSIVE DARK STARS: DETECTABLE IN JWST

The first phase of stellar evolution in the history of the universe may be dark stars (DSs), powered by dark matter (DM) heating rather than by nuclear fusion. Weakly interacting massive particles (WIMPs), which may be their own antipartners, collect inside the first stars and annihilate to produce a heat source that can power the stars for millions to billions of years. In this paper, we show that these objects can grow to be supermassive dark stars (SMDSs) with masses {approx_gt}(10{sup 5}-10{sup 7}) M{sub sun}. The growth continues as long as DM heating persists, since DSs are large and cool (surface temperature {approx_lt}5 x 10{sup 4} K) and do not emit enough ionizing photons to prevent further accretion of baryons onto the star. The DM may be provided by two mechanisms: (1) gravitational attraction of DM particles on a variety of orbits not previously considered and (2) capture of WIMPs due to elastic scattering. Once the DM fuel is exhausted, the SMDS becomes a heavy main-sequence star; these stars eventually collapse to form massive black holes (BHs) that may provide seeds for supermassive BHs in the universe. SMDSs are very bright, with luminosities exceeding (10{sup 9}-10{sup 11}) L{sub sun}. Wemore » demonstrate that for several reasonable parameters, these objects will be detectable with the James Webb Space Telescope. Such an observational discovery would confirm the existence of a new phase of stellar evolution powered by DM.« less
Dissipative quantum theory: implications for quantum entanglement

Abstract Three inter-related topics are discussed here. (1) the Lindblad dynamics of quantum dissipative systems; (2) quantum entanglement in composite systems and its quantification based on the Tsallis entropy; and (3) robustness of entanglement under dissipation. After a brief review of the Lindblad theory of quantum dissipative systems and the idea of quantum entanglement in composite quantum systems illustrated by describing the three particle systems, the behavior of entanglement under the influence of dissipative processes is discussed. These issues are of importance in the discussion of quantum nanometric systems of current research.
Vapor-liquid equilibria for copolymer/solvent systems: Effect of “intramolecular repulsion”

Abstract The role intramolecular interactions in blend miscibility is well documented for polymer+copolymer mixtures (ten Brinke et al., 1983; Paul and Barlow, 1984). Some copolymer+polymer mixtures are miscible although their corresponding homopolymers are not miscible; for example, over a range of acrylonitrile content, styrene/acrylonitrile copolymers are miscible with poly(methyl methacrylate) but neither polystyrene nor polyacrylonitrile is miscible with poly(methyl methacrylate). Similarly, over a composition range, butadiene/acrylonitrile copolymers are miscible with poly(vinyl chloride) while none of the binary combinations of the homopolymers [polybutadiene, polyacrylonitrile, and poly(vinyl chloride)] are miscible. This behavior has been attributed to “intramolecular repulsion” between unlike copolymer segments. We have observed similar behavior in vapor-liquid equilibria (VLE) of copolymer+solvent systems. We find that acrylonitrile/butadiene copolymers have higher affinity for acetonitrile solvent than do polyacrylonitrile or polybutadiene. We attribute this non-intuitive behavior to “intramolecular repulsion” between unlike segments of the copolymer. This repulsive interaction is weakened when acetonitrile molecules are in the vicinity of unlike copolymer segments, favoring copolymer+solvent miscibility. We find similar behavior when acetonitrile is replaced by methyl ethyl ketone. To our best knowledge, this effect has not been reported previously for VLE. We have obtained VLE data for mixtures containing a solvent and a copolymer as a function of copolymer composition. It appears that, at a given solvent partial pressure, there may be copolymer composition that yields maximum absorption of the solvent. This highly non-ideal VLE phase behavior may be useful for optimum design of a membrane for a separation process.
More accurate tests for the statistical significance of result differences

Statistical significance testing of differences in values of metrics like recall, precision and balanced F-score is a necessary part of empirical natural language processing. Unfortunately, we find in a set of experiments that many commonly used tests often underestimate the significance and so are less likely to detect differences that exist between different techniques. This underestimation comes from an independence assumption that is often violated. We point out some useful tests that do not make this assumption, including computationally-intensive randomization tests.
Critical Evaluation of the ISCCP Simulator Using Ground-Based Remote Sensing Data

Abstract Given the known shortcomings in representing clouds in global climate models (GCMs), comparisons with observations are critical. The International Satellite Cloud Climatology Project (ISCCP) diagnostic products provide global descriptions of cloud-top pressure and column optical depth that extend over multiple decades. Given the characteristics of the ISCCP product, the model output must be converted into what the ISCCP algorithm would diagnose from an atmospheric column with similar physical characteristics. This study evaluates one component of this so-called ISCCP simulator by comparing ISCCP results with simulated ISCCP diagnostics that are derived from data collected at the Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) Climate Research Facility. It is shown that if a model were to simulate the cloud radiative profile with the same accuracy as can be derived from the ARM data, the likelihood of that occurrence being classified with similar cloud-top pressure and ...
Bi73–: The Missing Family Member, Finally Isolated and Characterized

The synthesis and structure of Bi73–, the only missing member of the family of heptanuclear pnictogen cluster anions Pn73– (Pn = pnictogen, a group 15 element excluding the unique nitrogen), is reported. The new species is synthesized by oxidation of a solution of K5Bi4 by the solvent pyridine in the presence of (C6H6)Cr(CO)3. The existence of the species in solution is confirmed by electrospray mass spectrometry, while its structure is elucidated by single-crystal X-ray diffraction in the compound [K(2,2,2-crypt)]3Bi7·2py (monoclinic, P21/n, a = 13.8739(13) A, b = 24.878(2) A, c = 26.401(2) A, β = 96.353(4)°, V = 9056.5(14) A3, Z = 4, and R1/wR2 = 0.0636/0.1390 for the observed data and 0.0901/0.1541 for all data).
Oded Schramm: From Circle Packing to SLE

When I first met Oded Schramm in January 1991 at the University of California, San Diego, he introduced himself as a “Circle Packer”. This modest description referred to his Ph.D. thesis around the Koebe-Andreev-Thurston theorem and a discrete version of the Riemann mapping theorem, explained below. In a series of highly original papers, some joint with Zhen-Xu He, he created powerful new tools out of thin air, and provided the field with elegant new ideas. At the time of his deadly accident on September 1st, 2008, he was widely considered as one of the most innovative and influential probabilists of his time. Undoubtedly, he is best known for his invention of what is now called the Schramm-Loewner Evolution (SLE), and for his subsequent collaboration with Greg Lawler and Wendelin Werner that led to such celebrated results as a determination of the intersection exponents of two-dimensional Brownian frontier. But already his previous work bears witness to the brilliance of his mind, and many of his early papers contain both deep and beautifully simple ideas that deserve better knowing.
Modulated entanglement evolution via correlated noises

We study entanglement dynamics in the presence of correlated environmental noises. Specifically, we investigate the quantum entanglement DYNAMics of two spins in the presence of correlated classical white noises, deriving Markov master equation and obtaining explicit solutions for several interesting classes of initial states including Bell states and X form density matrices. We show how entanglement can be enhanced or reduced by the correlation between the two participating noises.
Radiative Properties of Rough Surfaces

Most studies on surface roughness effects are based on geometrical optics. This analytical investigation treats the surface roughness effects from wave optics considerations, thus accounting for the interference of waves. The rough surface is sinusoidal, infinite in extent and it is irradiated by plane monochromatic waves. The scattering of electromagnetic waves by the rough surface is determined by the direct solution of Maxwell's equations instead of the commonly used Huygens-Kirchhoff approximation (Beckmann's reflectance). Consequently, the solution is not restricted to small wavelength to roughness ratios; furthermore, polarization effects can be accounted for. The results indicate that the transmittance of the rough surface exhibits a maximum near the point where the wavelength of the surface roughness is the same as the wavelength of the radiation. The interval around this point is called transition region because the surface changes from specular to diffuse. The radiative properties are influenced by both the pitch and amplitude of the roughness. The results approach Fresnel's law when the pitch and amplitude of the surface become small compared to the wavelength of the radiation. Similarly, the surfaces become specular even at larger pitch if the amplitude of the roughness is small. It is also shown that Beckmann's reflectance relation is the limiting case of the reflectance obtained by the direct solution of Maxwell's equations. In addition, numerical results are presented on the effective properties of rough dielectric plates with various refractive indices and optical thicknesses.
Constraining the Nature of the Galactic Center X-Ray Source Population

We searched for infrared counterparts to the cluster of X-ray point sources discovered by Chandra in the Galactic center region (GCR). While the sources could be white dwarfs, neutron stars, or black holes accreting from stellar companions, their X-ray properties are consistent with magnetic cataclysmic variables (CVs), or high-mass X-ray binaries (HMXBs) at low accretion rates. A direct way to decide between these possibilities, and hence between alternative formation scenarios, is to measure or constrain the luminosity distribution of the companions. Using infrared (J, H, K, Brγ) imaging, we searched for counterparts corresponding to typical HMXB secondaries: spectral type B0 V with K < 15 at the GCR. We found no significant excess of bright stars in Chandra error circles, indicating that HMXBs are not the dominant X-ray source population and that they account for fewer than 10% of the hardest X-ray sources.
Cinchona Alkaloids as Organocatalysts in Enantioselective Halofunctionalization of Alkenes and Alkynes

Naturally occurring cinchona alkaloids include quinine, quinidine, cinchonine, and cinchonidine. Many of their derivatives are also readily available. This Focus Review summarizes recent applications of cinchona alkaloid derivatives, an important class of organocatalysts, in enantioselective halofunctionalization of alkenes and alkynes. Most successful examples in this area are intramolecular halofunctionalizations, where the nucleophile is tethered with the alkene or alkyne substrate. Only a few catalytic enantioselective intermolecular halofunctionalization of alkenes have been realized. Dimeric cinchona alkaloids are the most frequently used catalysts in asymmetric halofunctionalizations. Most other catalysts have an appended functional group on the C9 position of the cinchona alkaloids. These functional groups include (thio)urea, thiocarbamate, and sulfonamides.
Electronic Properties of Grain Boundaries in GaAs: A Study of Oriented Bicrystals Prepared by Epitaxial Lateral Overgrowth.

The electronic properties of tilt boundaries with misorientation angles ranging from 0 to 30° in n-type GaAs bicrystal layers have been investigated. The current-voltage and capacitance-voltage characteristics are consistent with a double-depletion-region model. The height of the grain boundary potential barrier remains constant while the density of grain boundary states varies with misorientation angle. Deep level transient spectroscopy has revealed the presence of two bands of grain boundary states at approximately 0.65 and 0.9 eV below the conduction band. These states are attributed to bond reconstruction at the grain boundary.
Why Has the Contemporaneous Linear Returns‐Earnings Relation Declined?

We investigate two explanations for the declining contemporaneous linear relation between annual stock returns and accounting earnings over the past 30 years: (1) earnings increasingly reflect news with a lag relative to stock prices and (2) earnings increasingly reflect good and bad news in an asymmetric fashion. We hypothesize and find that annual earnings have a weaker association with current price changes and a stronger association with lagged price changes over time. We hypothesize and find that annual earnings reflect current positive price changes less strongly and current negative price changes more strongly over time. We also find that asymmetry with respect to lagged price changes is increasingly important over time. Strikingly, we find that, since the mid‐1980s, the aggregation of earnings over a four‐year window increasingly does less to reduce the importance of lags and asymmetry.
Beyond location: data security in the 21st century

The continued attention to data protection and the growth of cloud computing highlight tensions among data protection regulators, businesses, and the computer science communities. As new data protection laws are proposed, these groups have the chance to share insights and achieve their respective goals; but right now, with respect to data security, they may be passing by each other. Going forward, governments, companies, and computer scientists must work together to fashion security for the 21st century.In this short piece, I argue that data protection goals that focus on where data is located as a way to exert jurisdiction clash with best practices in security and networking. From a security perspective, location-based rules falter in a large area such as the EU; they fail in smaller markets. Uncoupling jurisdiction and data location will allow data protection to move forward. Jurisdictional interests are real. Governments want to be able to reach out and touch our data. They also want to enforce laws to protect their citizens and their data. At the same time the proposed General Data Protection Regulation (GDPR) seeks to prevent unauthorized access to and, by extension, use of data. It mandates using measures “to ensure a level of security appropriate to the risks represented by the processing and the nature of the personal data to be protected.” Those responsible for data must also “protect personal data against accidental or unlawful destruction or accidental loss and to prevent any unlawful forms of processing, in particular any unauthorized disclosure, dissemination or access, or alteration of personal data.” Meeting these interests requires embracing the latest in security, networking, and cloud computing practices. Many of the best systems rely on continual movement of data to achieve the specific goals the GDPR sets. Thus location-based security is a failing strategy. At the same time, the era when a company could stick its data-head in the sand of one country and reject other countries’ laws may be over precisely because of government needs, global computing services, and advances in data security and networking. If companies wish to have the flexibility to employ different data management methods and especially ones that involve continual movement of data, they cannot simultaneously argue that no law or method covers how and when a government may gain access to data. As such, I offer thoughts on how treaties, processes for access to data, improved data breach laws, and an increased ability for companies to challenge government requests for data could work together to improve data security in the future.
JIP: Java image processing on the Internet

In this paper, we present JIP - Java Image Processing on the Internet, a new Internet based application for remote education and software presentation. JIP offers an integrate learning environment on the Internet where remote users not only can share static HTML documents and lectures notes, but also can run and reuse dynamic distributed software components, without having the source code or any extra work of software compilation, installation and configuration. By implementing a platform-independent distributed computational model, local computational resources are consumed instead of the resources on a central server. As an extended Java applet, JIP allows users to selected local image files on their computers or specify any image on the Internet using an URL as input. Multimedia lectures such as streaming video/audio and digital images are integrated into JIP and intelligently associated with specific image processing functions. Watching demonstrations an practicing the functions with user-selected input data dramatically encourages leaning interest, while promoting the understanding of image processing theory. The JIP framework can be easily applied to other subjects in education or software presentation, such as digital signal processing, business, mathematics, physics, or other areas such as employee training and charged software consumption.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Information Theoretically Secure, Enhanced Johnson Noise Based Key Distribution over the Smart Grid with Switched Filters

We introduce a protocol with a reconfigurable filter system to create non-overlapping single loops in the smart power grid for the realization of the Kirchhoff-Law-Johnson-(like)-Noise secure key distribution system. The protocol is valid for one-dimensional radial networks (chain-like power line) which are typical of the electricity distribution network between the utility and the customer. The speed of the protocol (the number of steps needed) versus grid size is analyzed. When properly generalized, such a system has the potential to achieve unconditionally secure key distribution over the smart power grid of arbitrary geometrical dimensions.
Effect of finite plate length on supersonic turbulent boundary layerwith large distributed surface injection

The two-dimensional, supersonic, turbulent boundary layer on a finite length flat plate with large injection is analyzed using integral moment methods which include the interaction between the viscous and inviscid flows. Data obtained at Mm = 2.6 are presented and show agreement with the analysis. As injection is increased, the velocity profiles become inflected, the sonic line moves away from the wall and the flow becomes "subcritical." Under this condition, the effect of termination of injection can be felt upstream of the end of injection. In particular, as injection rates approaching the maximum value which can be entrained by a constant pressure mixing layer are approached, the analysis predicts that virtually the entire blowing region experiences a falling pressure due to the effect of finite length. It is postulated that this effect provides for a smooth transition from a boundary-layer flow to one where mixing is negligible, except in a thin layer near the streamline which divides the injected and freestream gas.
The Classical Atom: Stabilization of Electronic Trojan Wavepackets

This article demonstrates that coherent states in Rydberg atoms can be produced and stabilized by combining a circularly polarized microwave field with a static, perpendicular magnetic field. These electronic wavepackets owe their stability to atomic analogs of the Lagrange equilibria which confine Jupiter's Trojan asteroids. While these “Trojan” wavepackets may slowly decay due to tunneling, a more significant source of dispersion will arise if the tails of the wavepacket penetrate appreciably into the non-linear or chaotic parts of phase space. In the laboratory frame, if these dispersive factors can be minimized — and this may be accomplished using magnetic fields — the electronic wavepacket will travel along a circular Kepler orbit while remaining localized radially and angularly for a finite — but large — number of Kepler periods. In this sense, the system is a classical Bohr atom.
A refined performance characterization of longest-queue-first policy in wireless networks

One of the major challenges in wireless networking is how to optimize the link scheduling decisions under interference constraints. Recently, a few algorithms have been introduced to address the problem. However, solving the problem to optimality for general wireless interference models is known to be NP-hard. The research community is currently focusing on finding simpler suboptimal scheduling algorithms and on characterizing the algorithm performance. In this paper, we address the performance of a specific scheduling policy called Longest Queue First (LQF), which has gained significant recognition lately due to its simplicity and high efficiency in empirical studies. There has been a sequence of studies characterizing the guaranteed performance of the LQF schedule, culminating at the construction of the σ-local pooling concept by Joo et al. In this paper, we refine the notion of σ-local pooling and use the refinement to capture a larger region of guaranteed performance.
Conditional Hedging and Portfolio Performance

Simple conditional currency-hedging rules often increase risk-adjusted portfolio returns and are thus of interest to investors. Several researchers have reported successful application of a “forward hedge rule” (FHR) in which one hedges whenever the foreign currency trades at a forward premium. An alternative strategy, a “real-interest-rate hedge rule” (RIR), is based on hedging when the domestic real interest rate exceeds the foreign rate. As an extension, we propose a combination of these rules—a “real forward hedge rule” (RFHR). We evaluate the performance of the rules for various currency, stock, and bond portfolios from the developed countries. In tests of risk-adjusted returns for 1976–1997, the RFHR significantly outperformed standard benchmarks and often beat the FHR and the RIR. Moreover, results of a simple dominance test for rolling 5- and 10-year periods suggest that the RFHR consistently improves portfolio performance for a U.S. investor.
Oxidative palladium(II) catalysis: A highly efficient and chemoselective cross-coupling method for carbon-carbon bond formation under base-free and nitrogenous-ligand conditions

We report herein the development of a general and mild protocol of oxygen-promoted Pd(II) catalysis resulting in the selective cross-couplings of alkenyl- and arylboron compounds with various olefins. Unlike most cross-coupling reactions, this new methodology works well even in the absence of bases, consequently averting undesired homo-couplings. Nitrogen-based ligands including dimethyl-phenanathroline enhance reactivities and offer a highly efficient and stereoselective methodology to overcome challenging substrate limitations. For instance, oxidative palladium(II) catalysis is effective with highly substituted alkenes and cyclic alkenes, which are known to be incompatible with other known catalytic conditions. Most examined reactions progressed smoothly to completion at low temperatures and in short times. These interesting results provide mechanistic insights and utilities for a new paradigm of palladium catalytic cycles without bases.
DagStream: locality aware and failure resilient peer-to-peer streaming

Live peer to peer (P2P) media streaming faces many challenges such as peer unreliability and bandwidth heterogeneity. To effectively address these challenges, general "mesh" based P2P streaming architectures have recently been adopted. Mesh-based systems allow peers to aggregate bandwidth from multiple neighbors, and dynamically adapt to changing network conditions and neighbor failures. However, a drawback of mesh-based overlays is that it is difficult to guarantee network connectivity in a distributed fashion, especially when network locality needs to be optimized. This paper introduces a new P2P streaming framework called DagStream, which (1) organizes peers into a directed acyclic graph (DAG) where each node maintains at least k parents, thus has provable network connectivity (and hence failure resilience), and (2) enables peers to quickly achieve locality awareness in a distributed fashion, thus ensures efficient network resource usage. Our experiment results in both simulation and wide area environment show that with our DagStream protocol, peers can quickly self-organize into a locality aware DAG. Further, by selecting additional parents as needed, peers can achieve good streaming quality commensurate with their downlink bandwidth.
Geodesics, distance, and the CAT(0) property for the manifold of Riemannian metrics

Given a fixed closed manifold M, we exhibit an explicit formula for the distance function of the canonical L 2 Riemannian metric on the manifold of all smooth Riemannian metrics on M. Additionally, we examine the (metric) completion of the manifold of metrics with respect to the L 2 metric and show that there exists a unique minimal path between any two points. This path is also given explicitly. As an application of these formulas, we show that the metric completion of the manifold of metrics is a CAT(0) space.
Evidence for a Disk-Jet Interaction in the Microquasar GRS 1915+105

We report simultaneous X-ray and infrared (IR) observations of the Galactic microquasar GRS 1915+105 using the Rossi X-Ray Timing Explorer and the Palomar 5 m telescope on 1997 August 13-15 UTC. During the last two nights, the microquasar GRS 1915+105 exhibited quasi-regular X-ray/IR flares with a spacing of ~30 minutes. While the physical mechanism triggering the flares is currently unknown, the one-to-one correspondence and consistent time offset between the X-ray and IR flares establish a close link between the two. At late times in the flares, the X-ray and IR bands appear to "decouple," with the X-ray band showing large-amplitude fast oscillations while the IR shows a much smoother, more symmetrical decline. In at least three cases, the IR flare has returned to near its minimum while the X-rays continue in the elevated oscillatory state, ruling out thermal reprocessing of the X-ray flux as the source of the IR flares. Furthermore, observations of similar IR and radio flares by Fender et al. imply that the source of the IR flux in such flares is synchrotron emission. The common rise and subsequent decoupling of the X-ray and IR flux and probable synchrotron origin of the IR emission are consistent with a scenario wherein the IR flux originates in a relativistic plasma that has been ejected from the inner accretion disk. In that case, these simultaneous X-ray/IR flares from a black hole/relativistic jet system are the first clear observational evidence revealing the time-dependent interaction of the jet and the inner disk in decades of quasar and microquasar studies.
Isolating Triggered Star Formation

Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding the importance of triggered star formation in a cosmological context.
Modifying MOFs: new chemistry, new materials

The postsynthetic modification (PSM) of metal–organic frameworks (MOFs) has grown substantially in the past few years. In this minireview, recent progress in the area of PSM is highlighted, with an emphasis on several recent advancements. The scope and limitations of PSM are described and future prospects are discussed.
The Dynamic Behavior of the Real Exchange Rate in Sticky Price Models

Since the breakdown of the Bretton Woods system of fixed exchange rates, the real exchange rates of the world's largest economies have been highly volatile. Furthermore, swings in these real exchange rates have been highly persistent. A large recent literature has studied whether the volatility and persistence of real exchange rates can be understood in the context of sticky price models with staggered price setting. This literature was pioneered by V. V. Chari, Patrick J. Kehoe, and Ellen R. McGrattan (2002). They concluded that such models can explain the volatility of the real exchange rate but that they cannot match its persistence. A number of sub? sequent papers have sought to address this "persistence anomaly" by introducing various forms of strategic complementarity and asymmetry, as well as sticky wages and persistent monetary
Reversing the Erosion of Editorial Diversity: How the Newspaper Preservation Act Has Failed and What Can Be Done

The Newspaper Preservation Act of 1970 (NPA) was ostensibly designed to protect editorial and reportorial diversity. From 1991 to 2006, however, twelve of twenty-two Joint-Operating Agreements have disappeared, including two in 2005. Another expires in 2007. Along with publishers' desires to monopolize markets for their own fiscal gain, the NPA can be blamed as failed policy that does not include penalties for violating the act's provisions or stipulations for how JOAs should be dissolved. This article considers why newspaper diversity is a valuable commodity worth preserving, traces the history and application of the NPA, and examines recent developments in related court cases and the newspaper business market. The article concludes that the federal government should consider amending or revising the NPA as a means of salvaging editorial diversity in JOA markets.
HIV Status and the Risk of Post-extraction Complications

Tooth extraction is commonly performed for patients infected with the human immunodeficiency virus (HIV). We undertook a prospective study to determine if HIV-positive patients had an increased risk for complications following tooth extraction. The study sample was composed of patients who presented for tooth extraction to the outpatient oral/maxillofacial surgery clinic at Grady Memorial Hospital, Atlanta, GA. The predictor variable was HIV status (positive or negative). The outcome variable was the presence or absence of a post-extraction complication. Other study variables were grouped into the following sets: (1) demographic, (2) past medical and social history, (3) clinical, (4) laboratory values, and (5) treatment. Between 11/93 and 4/96, 166 patients were enrolled. The study sample was composed of the 151 patients who completed the study protocol and consisted of 76 HIV-positive and 75 HIV-negative patients. The post-extraction complication rates were 22.3 and 13.3% for the HIV-positive and -negative groups, respectively (relative risk = 1.68, 95% confidence interval = 0.82 to 3.42, p = 0.15). The types of complications that occurred were similar in both groups. While the data suggest an increased rate of post-extraction complications in the HIV-positive group, the difference in complication rates between the two groups was not statistically significant. In addition, the complications were minor, self-limiting, and readily treated. Based on these findings, we believe that tooth extraction is a low-risk procedure in HIV-positive patients. Treatment may be rendered routinely to patients who present on an outpatient basis without the need for an extensive pre-operative work-up, unless otherwise indicated by relevant history.
Synthesis of Neoglycoconjugates by the Desulfurative Rearrangement of Allylic Disulfides

Two series of neoglycosyl donors are prepared on the basis of connection of an allylic disulfide motif to the anomeric center via a simple O-glycosyl linkage or N-glycosyl amide unit. Conjugation of both sets of donors to cysteine in peptides is demonstrated through classical disulfide exchange followed by the phosphine-mediated desulfurative allylic rearrangement resulting in neoglycopeptides characterized by a simple thioether spacer. The conjugation reaction functions in the absence of protecting groups on both the neoglycosyl donor and peptide in aqueous media at room temperature.
A threshold varying bisection method for cost sensitive learning in neural networks

We propose a bisection method for varying classification threshold value for cost sensitive neural network learning. Using simulated data and different misclassification cost asymmetries, we test the proposed threshold varying bisection method and compare it with the traditional fixed-threshold method based neural network and a probabilistic neural network. The results of our experiments illustrate that the proposed threshold varying bisection method performs better than the traditional fixed-threshold method based neural network. However, when compared to probabilistic neural network, the proposed method works well only when the misclassification cost asymmetries are low.
A software framework for non-repudiation service in electronic commerce based on the Internet

Abstract We propose a software framework for a non-repudiation security service in e-commerce (electronic commerce) on the Internet. The proposed software framework is a security framework for the non-repudiation security service. In the framework, we propose a systematic design methodology that provides a security class concept. Our framework can be differentiated from others. First, unlike other frameworks, it is interested in a successful completion of e-commerce transactions by supporting a non-repudiation security service. Second, the proposed framework is based on a dynamic mapping mechanism that improves the performance of e-commerce transactions. We made a set of experiments to measure the performance of three software frameworks—SSL, SET, and our NA framework. The experimental results show that our framework improves the performance of e-commerce transactions while providing a high quality of security services for desired e-commerce transactions.
The ATLAS zero degree calorimeter

Abstract In May of 2009 the ATLAS zero degree calorimeter was installed in its initial configuration and integrated into the ATLAS trigger/daq. The detector was designed to measure Global characteristics of events—particulary in PbPb collisions—through the measurement of energy and position of very forward neutral particles. Here we discuss the design and tests—particularly of radiation hardness.
Unexpected Dynamical Instabilities in Differentially Rotating Neutron Stars

A one-armed spiral instability has been found to develop in differentially rotating stellar models that have a relatively stiff, n = 1 polytropic equation of state and a wide range of rotational energies. This suggests that such instabilities can arise in neutron stars that are differentially, although not necessarily rapidly, rotating. The instability seems to be directly triggered by the presence of a corotation resonance inside the star. Our analysis also suggests that a resonant cavity resulting from a local minimum in the radial vortensity profile of the star plays an important role in amplifying the unstable mode. Hence, it appears as though this instability is closely related to the so-called Rossby wave instability (see work of Lovelace et al.) that has been found to arise in accretion disks. In addition to the one-armed (m = 1) spiral mode, we have found that higher order (m = 2 and 3) nonaxisymmetric modes also can become unstable if corotation points that resonate with the eigenfrequencies of these higher order modes also appear inside the star. The growth rate of each mode seems to depend on the location of its corotation radius with respect to the vortensity profile (or on the depth of its corotation radius inside the vortensity well). The existence of such instabilities makes the stability criterion for differentially rotating neutron stars nonunique. Also, the gravitational waves emitted from such unstable systems generally will not have a monochromatic frequency spectrum.
A Versatile Cyclodehydration Reaction for the Synthesis of Isoquinoline and β-Carboline Derivatives

The direct conversion of various amides to isoquinoline and β-carboline derivatives via mild electrophilic amide activation, with trifluoromethanesulfonic anhydride in the presence of 2-chloropyridine, is described. Low-temperature amide activation followed by cyclodehydration upon warming provides the desired products with short overall reaction times. The successful use of nonactivated and halogenated phenethylene derived amides, N-vinyl amides, and optically active substrates is noteworthy.
Regular and chaotic motion in softened gravitational systems

The stability of the dynamical trajectories of softened spherical gravitational systems is examined, both in the case of the full N-body problem and that of trajectories moving in the gravitational field of non-interacting background particles. In the latter case, for N ≥ 10 000, some trajectories, even if unstable, had exceedingly long diffusion times, which correlated with the characteristic e-folding time-scale of the instability. For trajectories of N 100 000 systems this time-scale could be arbitrarily large - and thus appear to correspond to regular orbits. For centrally concentrated systems, low angular momentum trajectories were found to be systematically more unstable. This phenomenon is analogous to the well-known case of trajectories in generic centrally concentrated non-spherical smooth systems, where eccentric trajectories are found to be chaotic. The exponentiation times also correlate with the conservation of the angular momenta along the trajectories. For N up to a few hundred, the instability time-scales of N-body systems and their variation with particle number are similar to those of the most chaotic trajectories in inhomogeneous non-interacting systems. For larger N (up to a few thousand) the values of the these time-scales were found to saturate, increasing significantly more slowly with N. We attribute this to collective effects in the fully self-gravitating problem, which are apparent in the time variations of the time-dependent Liapunov exponents. The results presented here go some way towards resolving the longstanding apparent paradoxes concerning the local instability of trajectories. This now appears to be a manifestation of mechanisms driving evolution in gravitational systems and their interactions - and may thus be a useful diagnostic of such processes.
The causes of Africa's food crisis.

Abstract This paper examines the causes of Africa's food crisis by examining patterns of food imports. The econometric results indicate that the rise in food imports during 1970-87 can be explained by a combination of demographic, policy, and economic factors which have raised domestic demand for imported food. These factors include urban migration, peaks in income (especially during commodity booms), lower international prices of food, and distorted exchange rates. After accounting for these factors, the residual trend in food imports per capita is negative over this period. Evidence is also presented showing that, in Ghana, policy reforms have led to reverse migration from urban to rural areas.
Some Koszul rings from geometry

Abstract We give examples of Koszul rings that arise naturally in algebraic geometry. In the first part, we prove a general result on Koszul property associated to an ample line bundle on a projective variety. Specifically, we show how Koszul property of multiples of a base point free ample line bundle depends on its Castelnuovo–Mumford regularity. In the second part, we give examples of Koszul rings that come from adjoint line bundles on minimal irregular surfaces of general type.
Turbulent flow around a wing/fuselage-type juncture

The flow over a 58-mm-thick uniform-thickness winglike body having a 1.5:1 elliptical leading edge and joined to a large flat plate (representing an aircraft fuselage) is characterized experimentally at freestream velocity 15 m/s, corresponding to Reynolds number 940,000/m, using hot-wire anemometry. The results are presented graphically, and it is found that the horseshoe vortex formed by the separation of the fuselage boundary layer ahead of the wing leading edge is effective in transporting turbulence and modifying the mean-flow characteristics and the turbulent-stress distribution. It is suggested that the slenderness ratio of the leading edge is the dominant factor affecting the strength and location of the vortex.
Effect of oral methyl-t-butyl ether (MTBE) on the male mouse reproductive tract and oxidative stress in liver

MTBE is found in water supplies used for drinking and other purposes. These experiments follow up on earlier reports of reproductive tract alterations in male mice exposed orally to MTBE and explored oxidative stress as a mode of action. CD-1 mice were gavaged with 400-2000 mg/kg MTBE on days 1, 3, and 5, injected i.p. with hCG (2.5 IU/g) on day 6, and necropsied on day 7. No effect was seen in testis histology or testosterone levels. Using a similar dosing protocol, others had initially reported disruption of seminiferous tubules in MTBE-gavaged mice, although later conclusions published were consistent with our findings. Another group had also reported testicular and other reproductive system abnormalities in male BALB/c mice exposed for 28 days to 80-8000 microg/ml MTBE in drinking water. We gave these MTBE concentrations to adult mice for 28 days and juvenile mice for 51 days through PND 77. Evidence of oxidative stress was examined in liver homogenates from the juvenile study using MDA, TEAC and 8OH2hG as endpoints. MTBE exposures at the levels examined indicated no significant changes in the male mouse reproductive tract and no signs of hepatic oxidative stress. This appears to be the first oral MTBE exposure of juvenile animals, and also the first to examine potential for MTBE to cause oxidative stress in vivo using a typical route of human exposure.
Metastable Synthesis of Diamond

Diamond can be grown metastably at subatmospheric pressures and moderate temperatures from hydrocarbon gases in the presence of atomic hydrogen. Atomic hydrogen can be generated by various methods, each of which generally leads to new chemical vapor deposition (CVD) diamond growth processes. Atomic hydrogen serves several critical roles in CVD diamond growth, namely: 1) stabilization of the diamond surface; 2) reduction of the size of the critical nucleus; 3) “dissolution” of carbon in the gas; 4) production of carbon solubility minimum; 5) generation of condensable carbon radicals in the gas; 6) abstraction of hydrogen from hydrocarbons attached to surface; 7) production of vacant surface sites; and 8) etching of graphite. Atomic hydrogen can carry out these functions because of favorable relationships between energies for carbon-carbon, carbon-hydrogen and hydrogen-hydrogen bonds. A direct substitute for atomic hydrogen has not been found although potential substitutes have been used to increase diamond growth rates. Potential substitutes have also been used indirectly to develop new methods of CVD diamond growth.
Methylphenylborohydride salts and methylphenylborane: New reagents for preparing methylphenylborane derivatives

Abstract A new metal borohydride, lithium methylphenylborohydride, was prepared, characterized and used to prepare methylphenylboranes of the type MePhBR.
Using existing systems to supplement small amounts of annotated grammatical relations training data

Grammatical relationships (GRs) form an important level of natural language processing, but different sets of GRs are useful for different purposes. Therefore, one may often only have time to obtain a small training corpus with the desired GR annotations. To boost the performance from using such a small training corpus on a transformation rule learner, we use existing systems that find related types of annotations.
Silicon-functionalized silyl enol ethers: A novel dialkylchlorosilyl enol ether and its conversion to alkoxy- and aminosilyl enol ethers

Abstract The lithium enolate derived from 3,3-dimethyl-2-butanone (pinacolone) reacted with dichlorodimethylsilane to yield a chlorosilyl enol ether, 3,3-dimethyl-2-(chlorodimethylsilyloxy)-1-butene, which reacts with numerous oxygen and nitrogen nucleophiles to yield silicon-functionalized silyl enol ethers.