cssi/SciSciGPT-SciSciNet huggingface dataset:
Local-in-Time Existence and Uniqueness of Solutions to the Prandtl Equations by Energy Methods

We prove local existence and uniqueness for the two-dimensional Prandtl system in weighted Sobolev spaces under Oleinik's monotonicity assumption. In particular we do not use the Crocco transform or any change of variables. Our proof is based on a new nonlinear energy estimate for the Prandtl system. This new energy estimate is based on a cancellation property that is valid under the monotonicity assumption. To construct the solution, we use a regularization of the system that preserves this nonlinear structure. This new nonlinear structure may give some insight into the convergence properties from the Navier-Stokes system to the Euler system when the viscosity goes to 0. © 2015 Wiley Periodicals, Inc.
One-sided uncertainty and delay in reputational bargaining

A two-person infinite-horizon bargaining model where one of the players may have either of two discount factors, has a multiplicity of perfect Bayesian equilibria. Introducing the slightest possibility that either player may be one of a rich variety of stationary behavioral types singles out a particular solution and appears to support some axiomatic treatments in the early literature in their conclusion that there is a negligible delay to agreement. Perturbing the model with a slightly broader class of behavioral types that allows the informed player to delay making his initial demand still achieves powerful equilibrium refinement. But there is substantial delay to agreement, and predictions depend continuously on the ex ante probabilities of the patient and impatient types of the informed player, counter to what the literature suggests.
Convex-Ear Decompositions and the Flag h-Vector

We prove a theorem allowing us to find convex-ear decompositions for rank-selected subposets of posets that are unions of Boolean sublattices in a coherent fashion. We then apply this theorem to geometric lattices and face posets of shellable complexes, obtaining new inequalities for their h-vectors. Finally, we use the latter decomposition to give a new interpretation to inequalities satisfied by the flag h-vectors of face posets of Cohen-Macaulay complexes.
Homogeneous Spiking Neuromorphic System for Real-World Pattern Recognition

A neuromorphic chip that combines CMOS analog spiking neurons and memristive synapses offers a promising solution to brain-inspired computing, as it can provide massive neural network parallelism and density. Previous hybrid analog CMOS-memristor approaches required extensive CMOS circuitry for training, and thus eliminated most of the density advantages gained by the adoption of memristor synapses. Further, they used different waveforms for pre and post-synaptic spikes that added undesirable circuit overhead. Here we describe a hardware architecture that can feature a large number of memristor synapses to learn real-world patterns. We present a versatile CMOS neuron that combines integrate-and-fire behavior, drives passive memristors and implements competitive learning in a compact circuit module, and enables in situ plasticity in the memristor synapses. We demonstrate handwritten-digits recognition using the proposed architecture using transistor-level circuit simulations. As the described neuromorphic architecture is homogeneous, it realizes a fundamental building block for large-scale energy-efficient brain-inspired silicon chips that could lead to next-generation cognitive computing.
Keeping a beat on the heart

We have developed and benchmarked real-time collection methods that exploit digital, packet-switched telephony services available in metropolitan areas. The Arrhythmia monitoring system collects real-time electrocardiogram signals from a mobile or homebound patient, and combines them with GPS location data, and transmits this information to a remote station for display and monitoring.
Integer Circuit Evaluation Is PSPACE-Complete

K. W. Wagner (1984, Technical report N/84/52, Friedrich?Schiler-Universitat Jena) introduced the integer circuit evaluation problem. Informally, the problem concerns a circuit that takes singleton sets, each containing one integer, and combines them using three types of set operations: A?B, A ?B={a·b?a?A, b?B}, and A?B={a+b?a?A, b?B}. The problem is to determine whether the set output by the circuit contains a particular integer. In this paper we show that the integer circuit problem is PSPACE-complete, resolving an open problem posed by P. McKenzie, H. Vollmer, and K. W. Wagner (2000, in “Proceedings of the 2000 FSTTCS conference, New Delhi, India, December).
A LISA data-analysis primer

This paper is an introduction for the nonpractitioner to the ideas and issues of LISA data analysis, as reflected in the explorations and experiments of the participants in the Mock LISA Data Challenges. In particular, I discuss the methods and codes that have been developed for the detection and parameter estimation of supermassive black-hole binaries, extreme mass-ratio inspirals and galactic binaries.
A practical and scalable process to selectively monofunctionalize water-soluble α,ω-diols

Abstract A practical protocol for rapid and scalable synthesis of monofunctionalized α,ω-diols using a simple and inexpensive THP ether protection/deprotection strategy was described. Use of inexpensive DHP source and ease to remove excess water-soluble α,ω-diols and THP ether after deprotection render the process scale-friendly without need of column chromatographic separation. The application of present method was also illustrated in the preparation of heterobifunctional diols and well-defined extended oligo(ethylene glycol).
A MECHANICAL OYSTER HARVESTER FOR SOUTH CAROLINA ESTUARIES

A mechanical oyster harvester has been developed for the intertidal oyster (Crassostrea virginica). The harvester is hydraulically powered and mounted on a 16 m steel hull vessel designed for its operation. The objective of this research was to produce a machine that would efficiently harvest oysters while doing minimum damage to the oysters and the fragile shell matrix that supports them. Results of three years' testing show harvest rates of 18 m3 /hour. Damage to the shell matrix was almost undetectable and damage to the harvested oysters was about 5%. The harvester can operate at depths of one to 3 m with the head controlled automatically. Bottom contact force is adjustable and regulated automatically during harvest to minimize bottom damage. The harvesting head can pitch or roll 0.35 rad to follow bottom contour. Future plans for the harvester include leasing to the L. P. Maggioni Oyster Company for commercial harvest during the 1982-83 season. Eventually the harvester will be used by the state of South Carolina for oyster bed management and transplanting of oysters from polluted areas to public shellfish grounds.
Nanoscale resonant-cavity-enhanced germanium photodetectors with lithographically defined spectral response for improved performance at telecommunications wavelengths

We demonstrate the use of a subwavelength planar metal-dielectric resonant cavity to enhance the absorption of germanium photodetectors at wavelengths beyond the material’s direct absorption edge, enabling high responsivity across the entire telecommunications C and L bands. The resonant wavelength of the detectors can be tuned linearly by varying the width of the Ge fin, allowing multiple detectors, each resonant at a different wavelength, to be fabricated in a single-step process. This approach is promising for the development of CMOS-compatible devices suitable for integrated, high-speed, and energy-efficient photodetection at telecommunications wavelengths.
A distribution-free nest survival model

In many nest survival studies, nests are not found until after incubation has begun and nests that fail are of unknown age while nests that succeed can be aged afterwards. Typically ornithologists have considered the survival time to be from first encounter and have used the Mayfield method (Mayfield, 1961, Wilson Bulletin 73, 255-261; Mayfield, 1975, Wilson Bulletin 87, 456-466) or variations of it. Here we consider a new discrete survival model that allows estimation of the survival distribution from the time of nest initiation. Nests that succeed are used to estimate the proportions of nests being found (encountered) in each time interval. Assuming that these encounter probabilities also apply to the nests that fail, it is possible to estimate a series of discrete failure time probabilities for all the nests. We present maximum likelihood estimators and computer programs to calculate them. Our methodology is illustrated and compared to other approaches using real data on mourning dove nests.
Stock market speculation and managerial myopia

Abstract This paper extends the analysis of managerial share price concerns by allowing informed trading in the stock market. It is shown that because they decrease the manager's information advantage vis-a-vis the stock market, individual investors who trade on private information improve the efficiency of corporate investment. This improvement does, however, fall short of first-best efficiency. Moreover, a stronger managerial share-price concern increases the expected profit from informed trading. Hence, by encouraging individual investors to collect information about corporate decisions and trade on it, managerial myopia tends to automatically bring forth a partial solution to the problems that it causes.
The Gromov invariants of Ruan-Tian and Taubes

Taubes has recently defined Gromov invariants for symplectic four-manifolds and related them to the Seiberg-Witten invariants. Independently, Ruan and Tian defined symplectic invariants based on ideas of Witten. In this note, we show that Taubes' Gromov invariants are equal to certain combinations of Ruan-Tian invariants. This link allows us to generalize Taubes' invariants. For each closed symplectic four-manifold, we define a sequence of symplectic invariants $Gr_{\delta}$, $\delta=0,1,2,...$. The first of these, $Gr_0$, generates Taubes' invariants, which count embedded J-holomorphic curves. The new invariants $Gr_{\delta}$ count immersed curves with $\delta$ double points. In particular, these results give an independent proof that Taubes' invariants are well-defined. They also show that some of the Ruan-Tian symplectic invariants agree with the Seiberg-Witten invariants.
Understanding the entanglement entropy and spectra of 2D quantum systems through arrays of coupled 1D chains

We describe an algorithm for studying the entanglement entropy and spectrum of two-dimensional (2D) systems, as a coupled array of $N$ one-dimensional chains in their continuum limit. Using the algorithm to study the quantum Ising model in 2D (both in its disordered phase and near criticality), we confirm the existence of an area law for the entanglement entropy and show that near criticality there is an additive piece scaling as ${c}_{\mathrm{eff}}\phantom{\rule{0.16em}{0ex}}\mathrm{log}(N)/6$ with ${c}_{\mathrm{eff}}\ensuremath{\approx}1$. Studying the entanglement spectrum, we show that entanglement gap scaling can be used to detect the critical point of the 2D model. When short-range (area law) entanglement dominates we find (numerically and perturbatively) that this spectrum reflects the energy spectrum of a single quantum Ising chain.
Processes regulating short-lived species in the tropical tropopause layer

[1] A one-dimensional model of vertical transport in the tropical tropopause layer (TTL) is developed. The model uses vertical advection, a convective source, and a chemical sink to simulate the profiles of very short lived substances in the TTL. The model simulates evanescent profiles of short-lived hydrocarbon species observed by satellite and is also used to simulate short-lived bromine species. Tracers with chemical lifetimes of 25 days or longer have significant concentrations in the stratosphere, and vertical advection is critical. Convection is important up to its peak altitude, nearly 19 km. Convection dominates the distribution of species with lifetimes less than 25 days. The annual cycle of species with lifetimes longer than 25 days is governed primarily by the variations of vertical velocity, not convection. This is particularly true for carbon monoxide, where a seasonal cycle in the lower stratosphere of the right phase is produced without variations in tropospheric emissions. An analysis of critical short-lived bromine species (CH 2 Br 2 and CHBr 3 ) indicates that substantial amounts of these tracers may get advected into the lower stratosphere as source gases at 18 km, and are estimated to contribute 2.8 pptv (1.1-4.1) to stratospheric bromine.
On the doubled tetrus

The “tetrus” is a member of a family of hyperbolic 3-manifolds with totally geodesic boundary, described by Paoluzzi–Zimmerman, which also contains W.P. Thurston’s “tripus.” Each member of this family has a branched cover to B3 over a certain tangle T. This map on the tripus has degree three, and on the tetrus degree four. We describe a cover of the double of the tetrus, itself a double across a closed surface, which fibers over the circle.
Segmentation of the Farallon slab

Abstract Recent tomography images reveal a complex 3D mantle structure beneath western United States, with feature morphology varying rapidly with depth. By assimilating plate motion history, paleo-age of sea floor, and paleo-geography of plate boundaries in a 3-D numerical model, we simulate the Farallon–Juan de Fuca subduction during the past 40 Ma. We find that the highly segmented upper mantle structure of western U.S. is a direct result of the Farallon subduction. We show that the tilted ‘horseshoe’-shaped fast seismic anomaly beneath Nevada and Utah at 300–600 km depth range is in fact a segment of curled slab subducted since 15 Ma, and the shallower linear slab beneath the Cascades is younger than 5 Ma. The distinct morphology between these two parts of the subduction system indicates the strong influence of the fast trench rollback since 20 Ma, the northward migrating JF–PA–NA triple-junction, and the toroidal flow around slab edges. The observed mantle structures are used to constrain the rheology of the upper mantle through matching the shape, depth, and location of modeled subducted slab segments. The inferred viscosity for the asthenosphere is 5 × 10 19 Pa s and those for the transition zone and lower mantle are 1.5 × 10 21 Pa s and 2 × 10 22 Pa s, respectively. The slab is found to be about 2 orders of magnitude stronger than the ambient mantle above 410 km depth, but of similar order of magnitude viscosity in the transition zone.
Encapsulation by Janus spheroids

Micro/nano encapsulation technology has acquired considerable attention in the fields of drug delivery, biomaterial engineering, and materials science. Based on recent advances in chemical particle synthesis, we propose a primitive model of an encapsulation system produced by the self-assembly of Janus oblate spheroids, particles with oblate spheroidal bodies and two hemi-surfaces coded with dissimilar chemical properties. Using Monte Carlo simulation, we investigate the encapsulation system with spherical particles as encapsulated guests, for different densities. We study the anisotropic effect due to the encapsulating agent's geometric shape and chemical composition on the encapsulation morphology and efficiency. Given the relatively high encapsulation efficiency we find from the simulations, we believe that this method of encapsulation has potential practical value.
Inclusive photoproduction of lepton pairs in the parton model

In the framework of the QCD parton model, we study unpolarized scattering of high energy real photons from a proton target into lepton pairs and a system of hadrons. For a given parametrization of parton distributions in the proton, we calculate the cross section of this process and show the cancellation of the interference terms.
Enabling and disabling factors in implementation of Studer Group's Evidence-Based Leadership initiative: a qualitative case study

AbstractUp to two-thirds of organization change initiatives fail. Current management literature on successful change implementation offers some advice; however, the focus is on sectors other than healthcare. This case study provides new insights about the implementation of Studer Group's Evidence-Based Leadership (EBL) change initiative in a health system by identifying specific enabling and disabling factors associated with successful implementation. Furthermore, it demonstrates varying relevance of these factors at different stages of implementation. Qualitative research methodology was used in this single-case study design to analyze in-depth interviews with 30 healthcare leaders and managers within the system. Interview questions addressed enabling and disabling factors at three stages of implementation: initiation, implementation management, and maintenance. Four themes emerged in the assessment of the enabling and disabling factors of EBL implementation: (1) Leadership, (2) Organizational Processes,...
Seismic response of submarine slopes

The geological profile of submerged slopes on the continental shelf typically includes soft cohesive soils with thicknesses ranging from a few meters to tens or hundreds of meters. The response of these soils in simple shear tests is largely influenced by the presence of an initial consolidation shear stress, inducing anisotropic stress-strain-strength properties which depend also on the direction of shear. In this paper, a new simplified effective-stress-based model describing the behavior of normally to lightly overconsolidated cohesive soils is used in conjunction with a one-dimensional seismic site response analysis computer code to illustrate the importance of accounting for anisotropy and small strain nonlinearity. In particular, a simple example is carried out to compare results for different slope inclinations. Depth profiling of the maximum shear strains and permanent deformations provide insight into the mechanisms of deformation during a seismic event, and the effects of sloping ground conditions.Copyright © 2003 by ASME
Synthesis of Fused Indazole Ring Systems and Application to Nigeglanine Hydrobromide

The single-step synthesis of fused tricyclic pyridazino[1,2-a]indazolium ring systems is described. Structural details revealed by crystallography explain the unexpected reactivity. The method is applied to the gram scale synthesis of nigeglanine hydrobromide.
Dehydrogenative condensation of SiH and SH bonds. A metal-catalyzed protocol to stable thiopolysiloxanes

Abstract Dehydrocoupling of polyhydrosiloxanes with thiols proceeded smoothly in the presence of Wilkinson's catalyst to furnish polythioethers in high yields under mild conditions. The process is free of rearrangement and cross-linking reactions.
Multicomponent Reaction Discovery: Three-Component Synthesis of Spirooxindoles

The Lewis acid-catalyzed, three-component reaction of isatin and two 1,3-dicarbonyl compounds is reported. Reactions proceed with high efficiency under mild reaction conditions and with good functional group tolerance to afford spirooxindole pyranochromenedione derivatives.
Banding together for bandwidth: An analysis of survey results from wireless community network participants

Using a resource mobilization framework, this study attempts to better understand the factors motivating people to join wireless community networks that enable members to share bandwidth. In addition, the research illuminates ties between this kind of peer-to-peer networking and civic engagement at a broader level. An in depth survey completed by 43 respondents from throughout Europe and North America found that participants in this movement felt a stronger sense of community, as well as were more likely to help elect local politicians and to work on local issue campaigns, after joining WiFi sharing initiatives. The study concludes with proposed policy recommendations—geared toward regulators, legislators and Internet service providers in the United States.
KCd2[N(CN)2]5(H2O)4: an enmeshed honeycomb grid.

The title compound, poly[potassium [diaqua­penta-μ2-dicyan­amido-dicadmium(II)] dihydrate], {K[Cd2(C2N3)5(H2O)2]·2H2O}n, contains two-dimensional anionic sheets of {[Cd2{N(CN)2}(H2O)2]−}n with a modified (6,3)-net (layer group cm2m, No. 35). Two sets of equivalent sheets inter­penetrate orthogonally to form a tetragonal enmeshed grid.
LIMITING DISTRIBUTION OF LAST PASSAGE PERCOLATION MODELS

Given a realization of the process, an up/right path from (0, 0) to (t, t) is a piecewise linear curve starting from (0, 0) to (t, t) joining Poisson points such that the slope, where defined, is positive. The length of an up/right path is defined by the number of points on it. Let L(t) be the length of the longest up/right path from (0, 0) to (t, t), making it a random variable. See Fig. 1 for an example of a last longest up/rigth path. This is a type of last passage
Generalized Collapse Solutions with Nonzero Initial Velocities for Star Formation in Molecular Cloud Cores

Motivated by recent observations that show that starless molecular cloud cores exhibit subsonic inward velocities, we revisit the collapse problem for polytropic gaseous spheres. In particular, we provide a generalized treatment of protostellar collapse in the spherical limit and find semianalytic (self-similar) solutions, corresponding numerical solutions, and purely analytic calculations of the mass infall rates (the three approaches are in good agreement). This study focuses on collapse solutions that exhibit nonzero inward velocities at large radii, as observed in molecular cloud cores, and extends previous work in four ways: (1) the initial conditions allow nonzero initial inward velocity, (2) the starting states can exceed the density of hydrostatic equilibrium so that the collapse itself can provide the observed inward motions, (3) we consider different equations of state, especially those that are softer than isothermal, and (4) we consider dynamic equations of state that are different from the effective equation of state that produces the initial density distribution. This work determines the infall rates over a wide range of parameter space, as characterized by four variables: the initial inward velocity v∞, the overdensity Λ of the initial state, the index Γ of the static equation of state, and the index γ of the dynamic equation of state. For the range of parameter space applicable to observed cores, the resulting infall rate is about a factor of 2 larger than that found in previous theoretical studies (those with hydrostatic initial conditions and v∞ = 0).
Recent investigations with the Harvard-Smithsonian cryogenic hydrogen maser

Abstract We have developed a hydrogen maser that operates near 0.5 K, using a high-cooling-power3He refrigerator. We are using this cryogenic hydrogen maser to study low temperature atomic hydrogen spin-exchange collisions and hydrogen-helium interactions, and to investigate the performance of cryogenic hydrogen masers as possibly improved frequency standards. We report recent measurements on these topics.
Chaos and chaotic phase mixing in cuspy triaxial potentials

This paper continues an investigation of chaos and chaotic phase mixing in triaxial generalizations of the Dehnen potential which have been proposed to describe realistic elliptical galaxies that have a strong density cusp and manifest significant deviations from axisymmetry. Earlier work is extended in three important ways, namely by exploring systematically the effects of (1) variable axis ratios, (2) ‘graininess’ associated, for example, with stars and bound substructures, idealized as friction and white noise, and (3) large-scale organized motions within a galaxy and a dense cluster environment, each presumed to induce near-random forces idealized as coloured noise with a finite autocorrelation time. The effects of varying the axis ratio were studied in detail by considering two sequences of models with cusp exponent γ = 1 and, respectively, axis ratios a : b : c = 1.00 : 1.00 − � : 0.50 and a : b : c = 1.00 : 1.00 − � : 1.00 − 2� for variable �. Three important conclusions are that (1) not all the chaos can be attributed to the presence of the cusp, (2) significant chaos can persist even for axisymmetric systems, and (3) the introduction of a supermassive black hole can induce both moderate increases in the relative number of chaotic orbits and substantial increases in the size of the largest Lyapunov exponent. In the absence of any perturbations, the coarse-grained distribution function associated with an initially localized ensemble of chaotic orbits evolves exponentially towards a
The Conserved PFT1 Tandem Repeat is Crucial for Proper Flowering in Arabidopsis thaliana

It is widely appreciated that short tandem repeat (STR) variation underlies substantial phenotypic variation in organisms. Some propose that the high mutation rates of STRs in functional genomic regions facilitate evolutionary adaptation. Despite their high mutation rate, some STRs show little to no variation in populations. One such STR occurs in the Arabidopsis thaliana gene PFT1 (MED25), where it encodes an interrupted polyglutamine tract. Although the PFT1 STR is large (∼270 bp), and thus expected to be extremely variable, it shows only minuscule variation across A. thaliana strains. We hypothesized that the PFT1 STR is under selective constraint, due to previously undescribed roles in PFT1 function. We investigated this hypothesis using plants expressing transgenic PFT1 constructs with either an endogenous STR or synthetic STRs of varying length. Transgenic plants carrying the endogenous PFT1 STR generally performed best in complementing a pft1 null mutant across adult PFT1-dependent traits. In stark contrast, transgenic plants carrying a PFT1 transgene lacking the STR phenocopied a pft1 loss-of-function mutant for flowering time phenotypes and were generally hypomorphic for other traits, establishing the functional importance of this domain. Transgenic plants carrying various synthetic constructs occupied the phenotypic space between wild-type and pft1 loss-of-function mutants. By varying PFT1 STR length, we discovered that PFT1 can act as either an activator or repressor of flowering in a photoperiod-dependent manner. We conclude that the PFT1 STR is constrained to its approximate wild-type length by its various functional requirements. Our study implies that there is strong selection on STRs not only to generate allelic diversity, but also to maintain certain lengths pursuant to optimal molecular function.
First quantized electrodynamics

Abstract The parametrized Dirac wave equation represents position and time as operators, and can be formulated for many particles. It thus provides, unlike field-theoretic Quantum Electrodynamics (QED), an elementary and unrestricted representation of electrons entangled in space or time. The parametrized formalism leads directly and without further conjecture to the Bethe–Salpeter equation for bound states. The formalism also yields the Uehling shift of the hydrogenic spectrum, the anomalous magnetic moment of the electron to leading order in the fine structure constant, the Lamb shift and the axial anomaly of QED.
Tree Modules and Counting Polynomials

We give a formula for counting tree modules for the quiver S g with g loops and one vertex in terms of tree modules on its universal cover. This formula, along with work of Helleloid and Rodriguez-Villegas, is used to show that the number of d-dimensional tree modules for S g is polynomial in g with the same degree and leading coefficient as the counting polynomial $A_{S_g}(d, q)$ for absolutely indecomposables over $\mathbb{F}_q$ , evaluated at q = 1.
EXPLORING THE ENERGETICS OF INTRACLUSTER GAS WITH A SIMPLE AND ACCURATE MODEL

The state of the hot gas in clusters of galaxies is investigated with a set of model clusters, created by assuming a polytropic equation of state ({gamma} = 1.2) and hydrostatic equilibrium inside gravitational potential wells drawn from a dark matter (DM) simulation. Star formation, energy input, and nonthermal pressure support are included. To match the gas fractions seen in nonradiative hydrodynamical simulations, roughly 5% of the binding energy of the DM must be transferred to the gas during cluster formation; the presence of nonthermal pressure support increases this value. In order to match X-ray observations, scale-free behavior must be broken. This can be due to either variation of the efficiency of star formation with cluster mass M{sub 500}, or the input of additional energy proportional to the formed stellar mass M{sub F} . These two processes have similar effects on X-ray scalings. If 9% of the gas is converted into stars, independent of cluster mass, then feedback energy input of 1.2 x 10{sup -5} M{sub F}c{sup 2} (or {approx}1.0 keV per particle) is required to match observed clusters. Alternatively, if the stellar mass fraction varies as {proportional_to}M {sup -0.26}{sub 500} then a lower feedback of 4 x 10{sup -6}more » M{sub F}c{sup 2} is needed, and if the stellar fraction varies as steeply as {proportional_to}M {sup -0.49}{sub 500} then no additional feedback is necessary. The model clusters reproduce the observed trends of gas temperature and gas mass fraction with cluster mass, as well as observed entropy and pressure profiles; thus they provide a calibrated basis with which to interpret upcoming Sunyaev-Zeldovich surveys. One consequence of the increased gas energy is that the baryon fraction inside the virial radius is {approx}<90% of the cosmic mean, even for the most massive clusters.« less
Discovering authorities and hubs in different topological Web graph structures

Abstract This research is a part of ongoing study to better understand citation analysis on the Web. It builds on Kleinberg's research (J. Kleinberg, R. Kumar, P. Raghavan, P. Rajagopalan, A. Tomkins, Invited survey at the International Conference on Combinatorics and Computing, 1999) that hyperlinks between web pages constitute a web graph structure and tries to classify different web graphs in the new coordinate space: out-degree, in-degree. The out-degree coordinate is defined as the number of outgoing web pages from a given web page. The in-degree coordinate is the number of web pages that point to a given web page. In this new coordinate space a metric is built to classify how close or far are different web graphs. Kleinberg's web algorithm (J. Kleinberg, Proceedings of the ACM-SIAM Symposium on Discrete Algorithms, 1998, pp. 668–677) on discovering “hub web pages” and “authorities web pages” is applied in this new coordinate space. Some very uncommon phenomenon has been discovered and new interesting results interpreted. This study does not look at enhancing web retrieval by adding context information. It only considers web hyperlinks as a source to analyze citations on the web. The author believes that understanding the underlying web page as a graph will help design better web algorithms, enhance retrieval and web performance, and recommends using graphs as a part of visual aid for search engine designers.
Thermophysical properties of Devonian shales

Abstract A detailed study of the thermophysical properties of Devonian shales from the central and eastern United States has been carried out. Thermal conductivity, thermal diffusivity, specific heat and dielectric constant data are presented. A Michigan shale sample with an oil yield of 28 litres per metric ton (1 t−1) and a Kentucky shale (oil yield: 52 l t−1) were selected. The specific heats of these shales are in the range 0.20–0.30 cal gm−1 °C−1, and increase with increasing temperature. The thermal conductivity (κ) of the two shale samples are comparable (ca. 1 W m−1 °C−1). The κ values show only a weak temperature dependance. The thermal diffusivity (α) of these shales range from 0.3–0.5 × 10−2 cm2 s−1 and tend to decrease with increasing temperature. The dielectric constants show anomalously high values at temperatures above 200 °C. This effect is indicative of interfacial polarization mechanisms presumably arising from loss of water and onset of pyrolysis of the shale organic matter. Comparison of the trends in thermophysical behaviour of Devonian shales with data obtained previously on Green River oil shales is presented. The importance of thermophysical measurements in on-field applications in oil shale technology is highlighted.
Phenytoin loading in chronic alcoholic patients

Controversy exists concerning the appropriate loading dose of phenytoin in chronic alcoholic patients. Chronic alcoholics are frequently assumed to have low albumin levels secondary to malnutrition and liver disease. Phenytoin is bound to albumin, and therefore the usual loading dose of phenytoin might result in a higher percentage of unbound drug and increased toxicity in these patients. Thirty-six chronic alcoholic patients were given a 15-mg/kg loading dose of phenytoin by constant intravenous infusion. After the infusion, patients were evaluated for clinical signs of phenytoin toxicity. At 1 hour after infusion, blood was sent for determination of total phenytoin, free phenytoin, and albumin levels. Fifteen patients were hypoalbuminemic (mean, 3.4 g/dL); 21 patients had albumin levels within the normal range (mean, 4.3 g/dL). In the hypoalbuminemic group, the mean free phenytoin level was 1.1 micrograms/mL, and the mean total phenytoin level was 13.6 micrograms/mL. In patients with normal albumin levels, the mean free phenytoin level was 1.3 micrograms/mL, and the mean total phenytoin level was 15.7 micrograms/mL. There were no statistically significant differences in total phenytoin or free phenytoin levels between either groups. No patient had a postinfusion phenytoin level (either free or total) within the toxic range. Although our sample size was small, our results suggest that a 15-mg/kg loading dose of phenytoin does not produce toxic levels in chronic alcoholics.
Calculation of Multipolar Exchange Interactions in Spin-Orbital Coupled Systems

A new method of computing multipolar exchange interaction in spin-orbit coupled systems is developed using multipolar tensor expansion of the density matrix in local density $\text{approximation}+\mathrm{U}$ electronic structure calculation. Within the mean field approximation, exchange constants can be mapped into a series of total energy calculations by the pair-flip approximation technique. The application to uranium dioxide shows an antiferromagnetic superexchange coupling in dipoles but a ferromagnetic one in quadrupoles which is very different from past studies. Further calculation of the spin-lattice interaction indicates it is of the same order with the superexchange and characterizes the overall behavior of the quadrupolar part as a competition between them.
Effect of sulfur segregation and hydrogen charging on intergranular fracture of iron

Abstract The effect of sulfur segregation and hydrogen charging on the grain boundary strength of iron was investigated by a slow strain-rate tensile test at 77 K. The amount of sulfur segregation at grain boundaries was controlled by varying the initial purity of specimens and quenching temperature and was determined by Auger electron spectroscopy after in situ fracture under ultra-high vacuum. The effect of hydrogen on grain boundary strength was examined at various grain boundary sulfur and/or hydrogen contents. The deleterious effects of sulfur and hydrogen on grain boundary strength were found to be independent and additive. The reversible effect of hydrogen is attributed to the reduction in the cohesive strength of grain boundaries due to atomic hydrogen whereas the irreversible effect is attributed to the damage due to molecular hydrogen precipitation.
Normality in Products

Abstract If P is a paracompact p -space, P × X is collectionwise normal, and Y is a closed image of X , then P × Y is collectionwise normal. If M is metric, X shrinking, and M × X is normal, then M × X is shrinking.
Proton decay and realistic models of quark and lepton masses

Abstract It is shown that in realistic SUSY GUT models of quark and lepton masses both the proton decay rate and branching ratios differ in general from those predicted in the minimal SU (5) supersymmetric model. The observation of proton decay, and in particular the branching ratio B[ (p → π + ν ) (p → K + ν ) ] , would thus allow decisive tests of these fermion mass schemes. It is shown that the charged lepton decay mode p → K 0 μ + arising through gluino dressing diagrams is significant and comparable to the neutrino modes in large tanβ models. Moreover, it is found that in certain classes of models the higgsino-mediated proton decay amplitudes are proportional to a model-dependent group-theoretical factor which in some cases can be quite small. There is thus a natural suppression mechanism which can explain without adjustment of parameters why in the context of SUSY GUTs proton decay has not yet been seen. The most interesting such class consists of SO (10) models in which the dominant flavor-symmetric contribution to the up-quark mass matrix comes from an effective operator of the form 16 i 16 j 10 H 45 H , where 〈 45 H 〉 points approximately in the I 3 R -direction. This class includes a recent model of quark and lepton masses proposed by the authors.
SoC Feedback Control for Wind and ESS Hybrid Power System Frequency Regulation

With increased penetration of wind generation, the traditional control scheme of the wind turbine (WT), which is designed for maximum wind power extraction, is no longer suitable to meet emerging grid requirements for wind farms to participate in frequency regulation. The control scheme of the WT with respect to grid frequency regulation is proposed in many studies, such as those on pitch control. Also, energy storage technologies have drawn much attention in recent years because, as technology matures and costs decrease, they present themselves as a potential solution for the challenge brought about by the uncertainty of renewable energy generation with regard to power system stability. A power system consisting of a high penetration of wind generation and energy storage systems (ESS) is investigated in this paper for the regulation of grid frequency. A new strategy called state of charge (SoC) feedback control is proposed, and the performance of the grid frequency deviation response and the SoC of the battery are presented. The model of the power system studied in this paper is established on the MATLAB/SIMULINK platform.
Vitamin D regulating TGF-β induced epithelial-mesenchymal transition

Subepithelial fibrosis is a characteristic hallmark of airway remodeling in asthma. A critical regulator of fibrosis, transforming growth factor β (TGF-β), can induce airway remodeling in epithelial cells through induction of epithelial-mesenchymal transition (EMT). Vitamin D has immunomodulatory functions, however, its effect on controlling subepithelial fibrosis is not known. Human bronchial epithelial cells (BEAS-2B) were exposed to calcitriol followed by stimulation with TGF-β1 or TGF-β2. The protein expression and mRNA transcripts for E-cadherin, Snail, vimentin, and N-cadherin were analyzed by Western blot and qPCR. An invasion assay and scratch wound assay were performed to identify the migratory properties of the cells following treatments. TGF-β1 decreased E-cadherin expression and increased protein expression and mRNA transcripts of Snail, vimentin, and N-cadherin together with increased cell invasion and migration. TGF-β2 elicited migratory response similar to TGF-β1 but induced the expression of EMT markers differently from that by TGF-β1. Calcitriol attenuated TGF-β1- and TGF-β2-induced cell motility. Also, calcitriol inhibited the expression of EMT markers in TGF-β1-treated epithelial cells with less effect on TGF-β2. These data suggest that calcitriol inhibits both migration and invasion induced by TGF-β1 and TGF-β2 in human airway epithelial cells. However, the regulatory effect of vitamin D in epithelial-mesenchymal transition was more effective to TGF-β1-induced changes. Thus, calcitriol could be a potential therapeutic agent in the prevention and management of subepithelial fibrosis and airway remodeling.
Quantifying Capsid Peptide:MHC I Complexes Following Adeno-Associated Virus (AAV) Transduction

Recent data from a clinical trial of adeno-associated virus (AAV) 2-mediated hepatic gene transfer of factor IX into hemophilia B subjects demonstrated the presence of AAV2-capsid-specific CD8+ T cells and identified an immunodominant AAV2 epitope. The expansion and contraction of this CD8+ T cell population coincided with the rise and fall of an asymptomatic elevation in liver transaminases, and correlated with the expression and subsequent loss of factor IX expression. These observations suggest that CD8+ T cells directed against AAV capsid antigen clear the transduced hepatocytes. Indeed, others in our laboratory have directly shown the lysis of AAV-transduced hepatocytes by CD8+ T cells in vitro . However, the stoichiometry and kinetics of AAV capsid degradation and processing for MHC class I presentation are presently unknown. We now report the generation of soluble AAV capsid-specific T cell receptor (TCR) tetramers and their use in quantifying capsid peptide:MHC I complexes presented on cell surfaces. CD8+ T cell clones specific for AAV2-derived peptide 74 (VPQYGYLTL) presented in the context of HLA-B*0702 were isolated and used to generate TCR cDNA. This cDNA was transfected into CHO cells to produce soluble TCR α and β chain fusion proteins. The soluble TCR was biotinylated, then tetramerized to streptavidin-conjugated fluorochrome for use in flow cytometric analyses. Cell lines expressing HLA-B*0702 were loaded with cognate AAV2 peptide, a cross-reactive AAV1 peptide (IPQYGYLTL), or irrelevant HLA-B*0702 epitopes derived from HIV-1 gp120 (IPRRIRGGL) or EBV nuclear antigen (RPPIFIRRL). Staining with TCR-tetramers reveals that this reagent binds AAV-derived peptides specifically. In addition, this reagent exhibits HLA-specificity, as cognate peptide loaded onto cells which express alternate HLA alleles was not detected. These results demonstrate that TCR-tetramers retain their antigen and MHC context specificities. Capsid peptide titration experiments using HLA-B*0702-bearing JYA2B7 and SK-MES-1 cell lines reveal that TCR-tetramers exhibit a limit of detection of approximately 105 cell surface peptide:MHC I complexes. Efficiency of detection is estimated at 1 peptide:MHC I complex for every 1010 peptide molecules added to cell culture. Preliminary studies indicate that the number of presenting complexes wanes by 48 hours following peptide loading. In contrast, AAV1-mediated transduction experiments demonstrate that capsid peptide:MHC I complexes are detectable after 48 hrs. In conclusion, these results are in agreement with our central hypothesis that AAV capsid is degraded upon transduction and gains access to MHC Class I antigen presentation pathways. Studies with the TCR-tetramers will allow definition of kinetics and capsid dose-dependence of antigen presentation, defining parameters of cell vulnerability to host immune-mediated clearance of transduced cells.
Enhancement of stereoselectivity in catalytic cyclopropanation reactions

Abstract Significant enhancement of trans(anti) stereoselectivity is achieved in rhodium(II) acetamide catalyzed cyclopropanation reactions of 2,3,4-trimethyl-3-pentyl diazoacetate (ODA) and diazoacetamides.
Investigation of the near-infrared spectral character of putative Martian chloride deposits

[1] Putative chloride salt deposits observed throughout the southern highlands of Mars by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) display featureless red slopes in near-infrared ratio spectra. It is hypothesized that the admixture of anhydrous chlorides or unoxidized sulfides with silicate rocks or minerals could imitate this spectral behavior. Three different sets of spectra were collected: (1) simple mixtures of halite with labradorite and flood basalt at multiple concentrations, (2) halite crusts formed on both labradorite and flood basalt, and (3) simple mixtures of 25 and 50 wt % acid-washed pyrite with labradorite and flood basalt. In all three instances, multiple grain sizes were used to evaluate the effect of particle size on spectral results. Spectra of the mixtures and crusts were divided by pure labradorite and flood basalt spectra of the same grain size to produce ratio spectra comparable to the CRISM ratio spectra. Our study rules out pyrite as a possible component of these deposits, whereas flood basalt mixtures with halite reproduced the observed red slope under some conditions. This allows us to place some broad constraints on halite proportions and the effective grain sizes of these deposits.
The Market for Mergers and the Boundaries of the Firm

Mergers are the mechanisms that redraw the boundaries of the firm. In this paper, we relate incomplete contracts, upon which much of our understanding of firm boundaries is based, to empirical regularities in the market for mergers and acquisitions. We begin by empirically challenging conventional wisdom about mergers and acquisitions: high M/B acquirers typically do not purchase low M/B targets. Instead, mergers typically pair together firms with similar M/B ratios. To show why this occurs, we build a continuous time model of investment and merger activity that combines search, relative scarcity, and asset complementarity. Our model shows that the ‘like buys like’ empirical finding is a natural consequence of a prediction from the property rights theory of the firm; namely, that complementary assets should be placed under common control. A number of new empirical predictions emerge from our analysis. First, if asset complementarity is important, then we should see small dierences in the M/B of targets and acquirers. It also predicts that the dierence in M/B ratios should increase when discount rates are high and valuations are low. In additional tests, we show that both of these predictions are borne out by the data. Our findings suggest that the incomplete contracts theory of the firm is central to understanding the empirical regularities of the market for mergers and acquisitions.
Activation of C-F bonds using Cp*2ZrH2: a diversity of mechanisms

The activation of several types of carbon–fluorine bonds in alkanes, arenes and olefins, using the early transition metal complex Cp*2ZrH2, are described. Fluoroalkanes are reduced to alkanes. Alkyl and and even aryl adducts containing β-fluorines undergo β-fluorine elimination. Evidence is presented that α-fluorine elimination is also possible, and occurs in Cp*2Zr(CF3)H. The studies include mechanistic investigations, which show evidence for a variety of pathways depending on the specific substrate.
Phase equilibria in stratified thin liquid films stabilized by colloidal particles

Phase equilibria between regions of different thickness in thin liquid films stabilized by colloidal particles are investigated using a quasi–two-dimensional thermodynamic formalism. Appropriate equilibrium conditions for the film tension, normal pressure, and chemical potential of the particles in the film are formulated, and it is shown that the relaxation of these parameters occurs consecutively on three distinct time scales. Film stratification is described quantitatively for a hard-sphere suspension using a Monte Carlo method to evaluate thermodynamic equations of state. Coexisting phases are determined for systems in constrained- and full-equilibrium states that correspond to different stages of film relaxation.
Hyperfine splittings of baryons containing a heavy quark in the Skyrme model

Abstract The Σ c ∗ − Σ c and Σ b ∗ − Σ b hyperfine mass splittings are computed in the Skyrme model. The hyperfine splitting are suppressed by both 1 N c and by 1 m Q , where Nc is the number of colors and mQ is the mass of the heavy quark. The Σc, Σc∗, Σb, Σb∗, and Λb masses are predicted in terms of the known values of the Λc, D, D∗, B B and B∗ masses.