cssi/SciSciGPT-SciSciNet huggingface dataset:
A Two-Temperature Model for Solid-Liquid Phase Change in Metal Foams

Transient solid-liquid phase change occurring in a phase-change material (PCM) embedded in a metal foam is investigated. Natural convection in the melt is considered. Volume-averaged mass and momentum equations are employed, with the Brinkman-Forchheimer extension to the Darcy law to model the porous resistance. Owing to the difference in the thermal diffusivities between the metal foam and the PCM, local thermal equilibrium between the two is not assured. Assuming equilibrium melting at the pore scale, separate volume-averaged energy equations are written for the solid metal foam and the PCM and are closed using an interstitial heat transfer coefficient. The enthalpy method is employed to account for phase change. The governing equations are solved implicitly using the finite volume method on a fixed grid. The influence of Rayleigh, Stefan, and interstitial Nusselt numbers on the temporal evolution of the melt front location, wall Nusselt number, temperature differentials between the solid and fluid, and the melting rate is documented and discussed. The merits of incorporating metal foam for improving the effective thermal conductivity of thermal storage systems are discussed.
Catalytic Conjugate Additions of Carbonyl Anions under Neutral Aqueous Conditions

The conjugate addition of carbonyl anions catalyzed by thiazolium salts that is fully operative under neutral aqueous conditions has been accomplished. The combination of α-keto carboxylates and thiazolium-derived zwitterions produces reactive carbonyl anions in a buffered protic environment that readily undergo conjugate additions to substituted α,β-unsaturated 2-acyl imidazoles. The scope of the reaction has been examined and found to accommodate various α-keto carboxylates and β-aryl substituted unsaturated 2-acyl imidazoles. The optimal precatalyst for this process is the commercially available thiazolium salt 5, a simple analogue of thiamin diphosphate. In this process, no benzoin products from carbonyl anion dimerization are observed. The corresponding 1,4-dicarbonyl compounds can be efficiently converted into esters and amides by way of activation of the N-methylimidazole ring via alkylation.
AGAINST MANY WORLDS INTERPRETATIONS

This is a critical review of the literature on many-worlds interpretations, MWI, with arguments drawn partly from earlier critiques by Bell and Stein. The essential postulates involved in various MWI are extracted, and their consistency with the evident physical world is examined. Arguments are presented against MWI proposed by Everett, Graham and DeWitt. The relevance of frequency operators to MWI is examined; it is argued that frequency operator theorems of Hartle and Farhi-Goldstone-Gutmann do not in themselves provide a probability interpretation for quantum mechanics, and thus neither support existing MWI nor would be useful in constructing new MWI. Comments are made on papers by Geroch and Deutsch that advocate MWI. It is concluded that no plausible set of axioms exists for an MWI that describes known physics.
Effects and detection of intermittent failures in digital systems

A great deal has been written during the past few years on the subject of diagnostic test procedures for digital systems. Almost without exception, however, the investigators have limited their interest to the detection and location of solid faults, and their test procedures are usually based on the assumption that either the fault exists for the running time of the test procedure or the time interval between the fault occurrence is less than the required time to run the test.
Gross-Schoen cycles and dualising sheaves

The aim of this paper is to study the modified diagonal cycle in the triple product of a curve over a global field defined by Gross and Schoen. Our main result is an identity between the height of this cycle and the self-intersection of the relative dualising sheaf. We have some applications to the following problems in number theory and algebraic geometry.
The role of porphyrin chemistry in tumor imaging and photodynamic therapy

In recent years several review articles and books have been published on the use of porphyrin-based compounds in photodynamic therapy (PDT). This critical review is focused on (i) the basic concept of PDT, (ii) advantages of long-wavelength absorbing photosensitizers (PS), (iii) a brief discussion on recent advances in developing PDT agents, and (iv) the various synthetic strategies designed at the Roswell Park Cancer Institute, Buffalo, for developing highly effective long-wavelength PDT agents and their utility in constructing the conjugates with tumor-imaging and therapeutic potential (Theranostics). The clinical status of certain selected PDT agents is also summarized (205 references).
Artificial Intelligence -- A Personal View

The goal of Artificial Intelligence is to identify and solve tractable information processing problems. In so doing, two types of theory arise. Here, they are labelled Types 1 and 2, and their characteristics are outlined. This discussion creates a more than usually rigorous perspective of the subject, from which past work and future prospects are briefly reviewed.
Unanticipated retention of configuration in the DAST fluorination of deoxy-4′-thiopyrimidine nucleosides with “up” hydroxyl groups

Abstract Fluorination of 1-(5-O-trityl-3-deoxy-4-thio-β-D-threo-pentofuranosyl)uracil (17) and 1-(5-O-trityl-2-deoxy-4-thio-β-D-threo- pentofuranosyl)uracil (20) with DAST proceeded with exclusive retention of configuration. The structures of the products were confirmed by X-ray analysis.
Scheduling for Optimal Rate Allocation in Ad Hoc Networks With Heterogeneous Delay Constraints

This paper studies the problem of scheduling in single-hop wireless networks with real-time traffic, where every packet arrival has an associated deadline and a minimum fraction of packets must be transmitted before the end of the deadline. Using optimization and stochastic network theory we study the problem of scheduling to meet quality of service (QoS) requirements under heterogeneous delay constraints and time-varying channel conditions. Our analysis results in an optimal scheduling algorithm which fairly allocates data rates to all flows while meeting long-term delay demands. We also prove that under a simplified scenario our solution translates into a greedy strategy that makes optimal decisions with low complexity.
Genetic algorithms and artificial life

Genetic algorithms are computational models of evolution that play a central role in many artificial-life models. We review the history and current scope of research on genetic algorithms in artificial life, giving illustrative examples in which the genetic algorithm is used to study how learning and evolution interact, and to model ecosystems, immune system, cognitive systems, and social systems. We also outline a number of open questions and future directions for genetic algorithms in artificial-life research.
A New Class of High-Resolution Measurements of Arbitrary-Dispersion Fibers: Localization of Four-Photon Mixing Process

A new technique for dispersion mapping of low dispersion fibers is reported. A counter-colliding pump-probe power transfer is used to achieve localized four-photon mixing at arbitrary waveguide locations. By controlling the position and strength of the counter-colliding interaction, the entire waveguide length is scanned to obtain high-resolution dispersion map. The new technique is used to demonstrate meter-scale dispersion retrieval in highly nonlinear fibers for the first time.
Synthesis, properties and applications of colloidal germanium and germanium-based nanomaterials

Germanium nanoparticles have excited scientists and engineers because of their size-dependent optical properties and their potential applications in optoelectronics, biological imaging and therapeutics, flash memories, and lithium-ion batteries. In order to further develop these applications and to gain deeper insights into their size-dependent properties, robust and facile synthetic methods are needed to controllably synthesize Ge nanoparticles. However, when compared to other II–VI, IV–VI, and III–V semiconductor systems, colloidal routes to Ge NPs with uniform sizes and shapes are much less mature. In this Review Article, we highlight the progress that has been made in this field and provide insights into the strategies used for the colloidal synthesis of size and shape-controlled germanium nanomaterials. We also survey some of the potential applications of these materials in optoelectronics, biological imaging, and energy conversion and storage. Finally, we discuss the colloidal synthesis of other germanium-containing compounds, emphasizing technologically relevant germanium chalcogenides that include GeS, GeSe, and GeTe.
Hidden Markov Estimation of Bistatic Range From Cluttered Ultra-Wideband Impulse Responses

Ultra-wideband (UWB) multistatic radar can be used for target detection and tracking in buildings and rooms. Target detection and tracking relies on accurate knowledge of the bistatic delay. Noise, measurement error, and the problem of dense, overlapping multipath signals in the measured UWB channel impulse response (CIR) all contribute to make bistatic delay estimation challenging. It is often assumed that a calibration CIR, that is, a measurement from when no person is present, is easily subtracted from a newly captured CIR. We show this is often not the case. We propose modeling the difference between a current set of CIRs and a set of calibration CIRs as a hidden Markov model (HMM). Multiple experimental deployments are performed to collect CIR data and test the performance of this model and compare its performance to existing methods. Our experimental results show an RMSE of 2.85 ns and 2.76 ns for our HMM-based approach, compared to a thresholding method which, if the ideal threshold is known a priori, achieves 3.28 ns and 4.58 ns. By using the Baum-Welch algorithm, the HMM-based estimator is shown to be very robust to initial parameter settings. Localization performance is also improved using the HMM-based bistatic delay estimates.
Catalytic reactions and reactors: A surface science approach

Abstract An integrated analysis of surface chemical reactions and reactors is central to the rational design of a catalytic reactor. Developments have, however, proceeded along two different paths; and much of the interaction that has occurred has been through the analysis of the reaction-diffusion problem within a catalyst pellet, and of multistationarity and instability. It is only during the last 10–15 years that such studies have tended to include a major emphasis on surface reactions with all their nonidealities (such as heterogeneity and lateral interaction between adsorbed molecules), and their role in inducing multiplicity and instability. Basic to a consideration of reactions on nonideal surfaces is the formulation of the adsorption integral equation and its solution under various conditions, including the use of a nonideal local isotherm (such as the Fowler-Guggenheim or the quasichemical) as the local isotherm in the integral equation. In the present monographic review, various aspects of adsorption pertinent to the subject are considered, including the derivation and solution of the adsorption integral equation. Methods of modelling catalytic reactions are also discussed, with a brief overview of the latest statistical methods used. The concept of the statistical rate on a nonuniform (heterogeneous) surface is then introduced, and procedures for formulating expressions for these rates are presented both for simple and complex reactions involving single as well as multicomponent adsorption. This is followed by a brief discussion of the characterization of surface heterogeneity in which the use of information theory and fractal analysis is highlighted. The role of the catalyst surface in inducing multiple steady states is explained, and various situations under which this can happen are stressed. Multiplicity can also occur as a result of feedback of mass or energy within a pellet or reactor. Although the literature in this area is extensive, the use of some of the newer mathematical tools such as the catastrophe and singularity theories in dealing with this problem is discussed, though very selectively. And, finally, the effects of incorporating surface nonidealities on the performance of a fixed-bed catalytic reactor are explored, and it is shown how these can be quite dramatic under certain conditions. It has so far only been possible to incorporate some very rudimentary effects of nonideality in the analysis, such as the use of the Fowler-Guggenheim or the quasichemical isotherm. No attempt has yet been made to include surface heterogeneity also through the adsorption integral equation. With the increasing use of parallel computing, it should be possible to explore the surface space and its role in directing a reaction in greater detail (through Monte Carlo simulation), and possibly, within the foreseeable future, one can also hope to formally incorporate these effects in reactor design for simple reactions.
Methodology for Optimal In Situ Alignment and Setting of Bendable Optics for Diffraction-Limited Focusing of Soft X-Rays

We demonstrate a comprehensive and broadly applicable methodology for the optimal in situ configuration of bendable soft x-ray Kirkpatrick-Baez mirrors. The mirrors used for this application are preset at the Advanced Light Source Optical Metrology Laboratory prior to beam- line installation. The in situ methodology consists of a new technique for simultaneously setting the height and pitch angle of each mirror. The benders of both mirrors were then optimally tuned in order to minimize ray aberrations to a level below the diffraction-limited beam waist size of 200 nm ðhorizontalÞ × 100 nm ðverticalÞ. After applying this methodol- ogy, we measured a beam waist size of 290 nm ðhorizontalÞ × 130 nm ðverticalÞ with 1 nm light using the Foucault knife-edge test. We also dis- cuss the utility of using a grating-based lateral shearing interferometer with quantitative wavefront feedback for further improvement of bendable optics. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attri- bution of the original publication, including its DOI. (DOI: 10.1117/1.OE.52.3.033603)
INSURANCE‐INDUCED MORAL HAZARD: A DYNAMIC MODEL OF WITHIN‐YEAR MEDICAL CARE DECISION MAKING UNDER UNCERTAINTY

Health insurance may lead individuals to overconsume medical care. Many studies explore this moral hazard using models that aggregate medical care decisions up to the annual level. Using employer-employee matched data from the Medical Expenditure Panel Survey (MEPS), I estimate moral hazard using a dynamic model of within-year medical care consumption that allows for endogenous health transitions, variation in medical care prices, and individual uncertainty within a health insurance year. I then estimate moral hazard under a second set of conditions that are consistent with the assumptions of most annual decision-making models. The within-year decision-making model produces a moral hazard estimate that is 19.2% larger than the alternative model. I highlight the importance of controlling for within-year dynamics in a model of medical care consumption using a counterfactual policy simulation that implements the individual mandate provision of the 2010 Patient Protection and Aordable Care Act. I nd that full implementation of the policy decreases the percentage of uninsured individuals in the population being analyzed from 11.8% to 6.0%. Furthermore, when all uninsured individuals are forced into coverage, their predicted annual medical care expenditure increases by 45.5%.
A problem-specific fault-tolerance mechanism for asynchronous, distributed systems

The idle computers on a local area, campus area, or even wide area network represent a significant computational resource-one that is, however, also unreliable, heterogeneous, and opportunistic. We describe an algorithm that allows branch-and-bound problems to be solved in such environments. In designing this algorithm, we faced two challenges: (1) scalability, to effectively exploit the variably sized pools of resources available, and (2) fault tolerance, to ensure the reliability of services. We achieve scalability through a fully decentralized algorithm, in which the dynamically available resources are managed through a membership protocol. We guarantee fault tolerance in the sense that the loss of up to all but one resource will not affect the quality of the solution. For propagating information reliably, we use epidemic communication for both the membership protocol and the fault-tolerance mechanism. We have developed a simulation framework that allows us to evaluate design alternatives. Results obtained in this framework suggest that our techniques can execute scalably and reliably.
Staples and Office Depot: An Event-Probability Case Study

Investors in financial markets bet their dollars on whether amerger will raise or lower prices. Below, we apply an event-probability methodology to the proposed merger between Staples and Office Depot, which was challenged by the FTC and eventually withdrawn. In addition to a time-series regression,we also look at the effect of the merger in specific event windows. We find highlysignificant returns to the only rival firm in the relevant market. We estimate theprice effect of the merger and find it highly consistent with independent estimates.
A ghost-cell immersed boundary method for flow in complex geometry

An efficient ghost-cell immersed boundary method (GCIBM) for simulating turbulent flows in complex geometries is presented. A boundary condition is enforced through a ghost cell method. The reconstruction procedure allows systematic development of numerical schemes for treating the immersed boundary while preserving the overall second-order accuracy of the base solver. Both Dirichlet and Neumann boundary conditions can be treated. The current ghost cell treatment is both suitable for staggered and non-staggered Cartesian grids. The accuracy of the current method is validated using flow past a circular cylinder and large eddy simulation of turbulent flow over a wavy surface. Numerical results are compared with experimental data and boundary-fitted grid results. The method is further extended to an existing ocean model (MITGCM) to simulate geophysical flow over a three-dimensional bump. The method is easily implemented as evidenced by our use of several existing codes.
PARTICLE ACCELERATION AND THE PRODUCTION OF RELATIVISTIC OUTFLOWS IN ADVECTION-DOMINATED ACCRETION DISKS WITH SHOCKS

Relativisticoutflows(jets)ofmatterare commonly observedfromsystemscontaining blackholes.Thestrongest outflows occur in the radio-loud systems, in which the accretion disk is likely to have an advection-dominated structure. In these systems, it is clear that the binding energy of the accreting gas is emitted primarily in the form of particlesratherthanradiation.However,no comprehensivemodelforthediskstructureand theassociated outflows has yet been produced. In particular, none of the existing models establish a direct physical connection between the presence of the outflows and the action of a microphysical acceleration mechanism operating in the disk. In this paper we explore the possibility that the relativistic protons powering the jet are accelerated at a standing, centrifugally supported shock in the underlying accretion disk via the first-order Fermi mechanism. The theoretical analysis employed here parallels the early studies of cosmic-ray acceleration in supernova shock waves, and the particle acceleration and disk structure are treated in a coupled, self-consistent manner based on a rigorous mathematical approach. We find that first-order Fermi acceleration at standing shocks in advection-dominated disks proves to be a very efficient means for accelerating the jet particles. Using physical parameters appropriate for M87 and Sgr A � , we verify that the jet kinetic luminosities computed using our model agree with estimates based on observations of the sources. Subject headingg accretion, accretion disks — black hole physics — galaxies: jets — hydrodynamics
State corroding federalism

Competition among local governments in a decentralized political system is often thought to discipline lazy or corrupt officials, improving public good provision and increasing welfare. Some scholars note possible distortions due to spillovers or a ‘race-to-the-bottom’, but suggest that central transfers or regulations can remedy these. Both arguments take for granted a framework of constitutional order in which the central government can collect taxes, allocate transfers, and enforce regulations autonomously. But what if it can’t? We show that if central enforcement capacity is endogenous, interjurisdictional competition may itself erode the center’s ability to channel competition in welfare-enhancing directions. Regional governments may compete for capital by shielding firms from central tax collectors, bankruptcy courts, or regulators. The equilibrium result is weaker central law enforcement and usually lower welfare: interjurisdictional competition corrodes the state. We illustrate with three examples—from Russia, China, and the US—of cases in which such competition apparently encouraged subnational politicians to help firms evade central taxes or regulations.
New PDMP analogues inhibit process outgrowth in an insect cell line

d-threo-1-Phenyl-2-aminodecanoyl-3-morpholinopropanol (d-threo-PDMP) has previously been shown to inhibit the biosynthesis of glycosphingolipids (GSLs) in mammals and mammalian cell lines by the inhibition of glucosylceramide synthase. New d-threo-PDMP analogues were synthesized from d-serine, and found to suppress neurite extension in an embryonic insect cell line from the moth Manduca sexta, and in explanted neural tissue from insect pupae. Inhibition occurred at lower concentrations than d-threo-PDMP. The observed suppression of neurite formation was found to be reversible after the removal of the compounds. Due to their small size and short life cycle, M. sexta is shown to be an ideal model organism for studies of GSL effects in cellular development, and for drug development studies.
Splitting spacetime and cloning qubits: linking no‐go theorems across the ER=EPR duality

We analyze the no-cloning theorem in quantum mechanics through the lens of the proposed ER=EPR (Einstein-Rosen = Einstein-Podolsky-Rosen) duality between entanglement and wormholes. In particular, we find that the no-cloning theorem is dual on the gravity side to the no-go theorem for topology change, violating the axioms of which allows for wormhole stabilization and causality violation. Such a duality between important no-go theorems elucidates the proposed connection between spacetime geometry and quantum entanglement.
Using Pseudo-Parabolic and Fractional Equations for Option Pricing in Jump Diffusion Models

In mathematical finance a popular approach for pricing options under some Levy model would be to consider underlying that follows a Poisson jump diffusion process. As it is well known this results in a partial integro-differential equation (PIDE) that usually does not allow an analytical solution, while a numerical solution also faces some problems. In this paper we develop a new approach on how to transform the PIDE into a class of so-called pseudo-parabolic equations which are well known in mathematical physics but are relatively new for mathematical finance. As an example we will discuss several jump-diffusion models which Levy measure allows such a transformation.
La jungla de la teoría administrativa

THE OBJECTIVE OF THIS PAPER IS TO MAKE A CRITICAL REVIEW OF THE TAX POLICY IN MEXICO, CONSIDERING OF TWO MAIN ISSUES: THE CHARACTERISTICS OF THE MAIN TAXES AND THE CHARACTERISTICS OF AN EFFICIENT TAX STRUCTURE. AS IT IS DESIGNED, THE TAX STRUCTURE OF THE COUNTRY IS CLEARLY INEFFICIENT IN ORDER TO REDUCE CLOSE THE GAP BETWEEN POTENTIAL INCOME AND THE REAL ONE. IN ADDITION TO ITS INCAPACITY TO OBTAIN THE DISTRIBUTION OF THE INCOME. UNDER THESE CIRCUMSTANCES IT HAS BEEN TRIED TO EXCHANGE THE TRIBUTES ON THE RENT FOR THOSE TARGETING CONSUMPTION AND THEIR GENERALIZATION. THIS IN WAY FISCAL EVASION IS PREVENTED. ALTHOUGH ONE GRANTS THAT IT CAN BE A REGRESSIVE TAX SYSTEM IT IS ASSUMED THAT IT CAN BE CORRECTED BY MEANS OF THE RIGHT APPLICATION OF THE COST.
AN INSTABILITY DUE TO THE NONLINEAR COUPLING OF p-MODES TO g-MODES: IMPLICATIONS FOR COALESCING NEUTRON STAR BINARIES

A weakly nonlinear fluid wave propagating within a star can be unstable to three-wave interactions. The resonant parametric instability is a well-known form of three-wave interaction in which a primary wave of frequency ωa excites a pair of secondary waves of frequency ωb + ωc ≃ ωa. Here we consider a nonresonant form of three-wave interaction in which a low-frequency primary wave excites a highfrequency p-mode and a low-frequency g-mode such that ωb + ωc ≫ ωa. We show that a p-mode can couple so strongly to a g-mode of similar radial wavelength that this type of nonresonant interaction is unstable even if the primary wave amplitude is small. As an application, we analyze the stability of the tide in coalescing neutron star binaries to p-g mode coupling. We find that the equilibrium tide and dynamical tide are both p-g unstable at gravitational wave frequencies fgw & 20 Hz and drive short wavelength p-g mode pairs to significant energies on very short timescales (much less than the orbital decay time due to gravitational radiation). Resonant parametric coupling to the tide is, by contrast, either stable or drives modes at a much smaller rate. We do not solve for the saturation of the p-g instability and therefore we cannot say precisely how it influences the evolution of neutron star binaries. However, we show that if even a single daughter mode saturates near its wave breaking amplitude, the p-g instability of the equilibrium tide will: (i) induce significant orbital phase errors (�φ & 1 radian) that accumulate primarily at low frequencies (fgw . 50 Hz) and (ii) heat the neutron star core to a temperature of T ∼ 10 10 K. Since there are at least ∼ 100 unstable p-g daughter pairs, �φ and T are potentially much larger than these values. Tides might therefore significantly influence the gravitational wave signal and electromagnetic emission from coalescing neutron star binaries at much larger orbital separations than previously thought.
Achronal Limits, Lorentzian Spheres, and Splitting

In the early 1980s Yau posed the problem of establishing the rigidity of the Hawking–Penrose singularity theorems. Approaches to this problem have involved the introduction of Lorentzian Busemann functions and the study of the geometry of their level sets—the horospheres. The regularity theory in the Lorentzian case is considerably more complicated and less complete than in the Riemannian case. In this paper, we introduce a broad generalization of the notion of horosphere in Lorentzian geometry and take a completely different (and highly geometric) approach to regularity. These generalized horospheres are defined in terms of achronal limits, and the improved regularity we obtain is based on regularity properties of achronal boundaries. We establish a splitting result for generalized horospheres, which when specialized to Cauchy horospheres yields new results on the Bartnik splitting conjecture, a concrete realization of the problem posed by Yau. Our methods are also applied to spacetimes with positive cosmological constant. We obtain a rigid singularity result for future asymptotically de Sitter spacetimes related to results in Andersson and Galloway (Adv Theor Math Phys 6:307–327, 2002), and Cai and Galloway (Adv Theor Math Phys 3:1769–1783, 2000).
Covering Spheres with Spheres

Given a sphere of any radius r in an n-dimensional Euclidean space, we study the coverings of this sphere with solid spheres of radius one. Our goal is to design a covering of the lowest covering density, which defines the average number of solid spheres covering a point in a bigger sphere. For growing dimension n, we design a covering that gives the covering density of order (nln n)/2 for a sphere of any radius r>1 and a complete Euclidean space. This new upper bound reduces two times the order nln n established in the classic Rogers bound.
Molecular clouds in the Carina arm

Results from the first large-scale survey in the CO(J = 1 to 0) line of the Vela-Carina-Centaurus region of the Southern Milky Way are reported. The observations, made with the Columbia University 1.2 m millimeter-wave telescope at Cerro Tololo, were spaced every beamwidth (0.125 deg) in the range 270 deg is less than or = l is less than or = 300 deg and -1 deg less than or = b less then or = 1 deg, with latitude extensions to cover all Carina arm emission beyond absolute b = 1 deg. In a concurrent survey made with the same telescope, every half-degree in latitude and longitude was sampled. Both surveys had a spectral coverage of 330 km/s with a resolution of 1.3 km/s. The Carina arm is the dominant feature in the data. Its abrupt tangent at l is approx. = 280 deg and characteristic loop in the l,v diagram are unmistakable evidence for CO spiral structure. When the emission is integrated over velocity and latitude, the height of the step seen in the tangent direction suggests that the arm-interarm contrast is at least 13:1. Comparison of the CO and H I data shows close agreement between these two species in a segment of the arm lying outside the solar circle. The distribution of the molecular layer about the galactic plane in the outer Galaxy is determined. Between R = 10.5 and 12.5 kpc, the average CO midplane dips from z = -48 to -167 pc below the b = 0 deg plane, following a similar well-known warping of the H I layer. In the same range of radii the half-thickness of the CO layer increases from 112 to 182 pc. Between l = 270 deg and 300 deg, 27 molecular clouds are identified and cataloged along with heliocentric distances and masses. An additional 16 clouds beyond 300 deg are cataloged from an adjoining CO survey made with the same telescope. The average mass for the Carina arm clouds is 1.4x 10(6)M (solar), and the average intercloud spacing along the arm is 700 pc. Comparison of the distribution of the Carina arm clouds with that of similarly massive molecular clouds in the first and second quadrants strongly suggests that the Carina and Sagittarius arms form a single spiral arm approx. 40 kpc long wrapping two-thirds of the way around the Galaxy.
Thompson’s group F and uniformly finite homology

This paper demonstrates the uniformly nite homology developed by Block and Weinberger and its relationship to amenable spaces via applica- tions to the Cayley graph of Thompson's Group F. In particular, a certain class of subgraph of F is shown to be non-amenable (in the Flner sense). This shows that if F is amenable, these subsets (which include every nitely gener- ated submonoid of the positive monoid of F ) must necessarily have measure zero.
Preoperative cardiac risk assessment for noncardiac surgery

Coronary artery disease (CAD) represents an important risk in patients undergoing elective noncardiac surgical procedures, in whom the stress of surgery and postoperative recovery can represent a significant ischemic burden. Population considerations: Preoperative cardiac assessment should be based on the prevalence of CAD (if known) in the population undergoing the procedure and the institutional event rate for the procedure. Procedures considered high-risk are vascular, intra-abdominal or thoracic, major orthopedic, and any emergency procedures. Individual considerations: Clinical history : A history of angina, congestive heart failure, diabetes mellitus, prior myocardial infarction, ventricular ectopy, and/or elderly (age > 70) are clinical parameters of increased risk. Functional capacity : Good functional capacity is the ability of a 50–70-year-old patient to achieve 6–8 METS of activity without significant symptoms of dyspnea on exertion. Further noninvasive testing : Preoperative testing may include routine treadmill exercise testing, ambulatory ECG monitoring, echocardiographic stress testing with dobutamine or exercise, and/or thallium perfusion imaging. Strategy for high risk patients : Assessing the severity of an abnormality (e.g., with thallium) results in a small percentage of positive test results yielding a high positive predictive value for events. Therefore, more aggressive interventions should be reserved for the most abnormal noninvasive test results, and the severity of the risk assessment should impact the timing of any coronary revascularization procedure, not the decision to proceed to more invasive testing and therapies. In summary, it is important to realize that most of the patients being screened, even vascular surgery patients (with high prevalence of CAD and procedural risk), will be found suitable to go to surgery without additional invasive intervention and cardiac revascularization. Thus good functional capacity and absence of cardiac risk factors should direct 30–40% of this population to elective surgery without further evaluation. The finding of high-risk perfusion scan abnormalities appears to be limited to 15–20% of those patients being recommended for further noninvasive testing.
Residual Income Compensation Plans and Deferred Taxes

ABSTRACT: Residual income is a popular performance metric that is often calculated from financial accounting numbers. Practitioners argue that financial accounting earnings and book value suffer from various biases and should be adjusted prior to the residual income calculation so that the resulting residual income metric will have better incentive properties, but they often disagree about what the adjustments should be. Using the criterion that a residual income performance metric should align owner and managerial investment incentives, I develop a simple investment model to show how financial accounting choices and adjustments must be chosen jointly to achieve incentive alignment. In particular, I examine conflicting recommendations from the practitioner literature about the proper adjustment for deferred taxes and show that more than one adjustment method can achieve incentive alignment if paired with the correct depreciation schedule. Further, I show that relationships among accounting variables intro...
Sociallink: utilizing social network and transaction links for effective trust management in P2P file sharing systems

Current reputation systems for peer-to-peer (P2P) file sharing systems either fail to utilize existing trust within social networks or suffer from certain attacks (e.g., free-riding and collusion). To handle these problems, we introduce a trust management system, called SocialLink, that utilizes social network and historical transaction links. SocialLink manages file transactions through both the social network and a novel weighted transaction network, which is built based on previous file transaction history. First, SocialLink exploits the trust among friends in social networks by enabling two friends to share files directly. Second, the weighted transaction network is utilized to 1) deduce the trust of the client on a server in reliably providing the requested file and 2) check the fairness of the transaction. In this way, SocialLink prevents potential misbehaving transactions (i.e., providing faulty files), encourages nodes to contribute file resources to non-friends, and avoids free-riding. Furthermore, the weighted transaction network helps SocialLink resist whitewashing, collusion and Sybil attacks. Extensive simulation demonstrates that SocialLink can efficiently ensure trustable and fair P2P file sharing and resist the aforementioned attacks.
Stellar sources for heavy r-process nuclei

The stellar sites and the complete mechanism of r-process nucleosynthesis are still unresolved issues. From consideration of the observed abundances in metal-poor stars, it is proposed that the production of heavy r-process nuclei (r-nuclei with mass numbers A > 130) is not related to the production of Fe group elements or of elements with lower atomic numbers: Na, Mg, Al, Si, Ca, Sc, and Ti. This requires that the production of heavy r-nuclei not occur in supernovae with extended shell structure but be associated with either bare neutron stars or Type II supernovae (SNe II) in the mass range 8 M_☉ < M < 10 M_☉. From the observations of stars with [Fe/H] ~ -3 but with high abundances of r-elements, it is clear that these r-process enrichments cannot represent the composition of the interstellar medium from which the stars were formed but must represent very local contamination from binary companions. Further evidence for very high enrichments of s-process elements in metal-poor stars also requires binary systems for explanation. We propose that the accretion-induced collapse (AIC) of a white dwarf into a neutron star in a binary system may be associated with the production of heavy r-nuclei and may provide occasional coupling of high r-process and high s-process enrichments in the envelopes of low-mass stars with low [Fe/H]. If we assume that the bulk of the heavy r-nuclei are produced in AIC events, then these events would have produced ~1.6 × 109 neutron stars in the Galaxy. A much larger number of white dwarf binaries would have resulted from the evolution of other binary systems. The AIC scenario removes the assignment in our earlier model that SNe II provide the bulk of heavy r-nuclei and relegates r-process production in SNe II to light r-nuclei with A ≾ 130. This new assignment gives Fe yields that are in accord with the observed values for most SNe II.
Does trade raise income? Evidence from the twentieth century

Efforts to estimate the effects of international trade on a country's real income have been hampered by the failure to account for the endogeneity of trade. Frankel and Romer recently use a country's geographic attributes — notably its distance from potential trading partners — to construct an instrument to identify the effects of trade on income in 1985. Using data from the pre-World War I, the interwar, and the post-war periods, we find that the main result of Frankel and Romer is confirmed throughout the whole century: countries that trade more as a proportion of their GDP have higher incomes even after controlling for the endogeneity of trade. We also find that the OLS estimate of trade's effect on income is biased downwards in almost every sample year. However, this result is not robust to the inclusion of distance from equator (latitude). © 2002 Elsevier Science B.V. All rights reserved.
Tailorable stimulated Brillouin scattering in nanoscale silicon waveguides

Exploiting photon–phonon coupling in nanoscale silicon waveguides could enable a host of powerful features in photonic devices. Using a hybrid photonic–phononic waveguide structure, Shin et al. show stimulated Brillouin scattering nonlinearities and gain, which offers new on-chip signal-processing abilities.
Cycle-induced flow and transport in a model of alveolar liquid lining

A simplified model is developed for an alveolar liquid lining undergoing cyclic stretching which mimics breathing motions. A thin, viscous film coats an extensible alveolar wall with small aspect ratio, $\varepsilon$ . Scaling analysis and asymptotic theory are used to describe the interface profile and surfactant distribution during the oscillation cycle for either insoluble or soluble surfactants. The flow consists of two distinct regimes: an outer region away from the rigid endwalls where flow is near-parallel and a boundary-layer region at the rigid endwalls where flow is non-parallel. The system is solved asymptotically in the limit of $\varepsilon\ll 1$ and small strain amplitudes, $\Delta \ll 1$ . For leading order in $\varepsilon$ , steady streaming vortical flows are found at $O(\Delta^2)$ and their size, number and flow direction depend on the system parameter values. This preliminary model can be useful for understanding alveolar transport characteristics for slowly diffusing molecules with large Peclet number, such as endogenous surfactants and proteins as well as delivered surfactants, drugs and genetic material that may occur in various therapies or partial liquid ventilation. The flow pattern also provides a pathway for cell–cell signalling within the alveolus.
Using program synthesis for social recommendations

This paper presents a new approach to select events of interest to users in a social media setting where events are generated from mobile devices. We argue that the problem is best solved by inductive learning, where the goal is to first generalize from the users' expressed "likes" and "dislikes" of specific events, then to produce a program that can be used to collect only data of interest. The key contribution of this paper is a new algorithm that combines machine learning techniques with program synthesis technology to learn users' preferences. We show that when compared with the more standard approaches, our new algorithm provides up to order-of-magnitude reductions in model training time, and significantly higher prediction accuracies for our target application.1
Multi-robot Simultaneous Localization and Mapping using Particle Filters

This paper describes an on-line algorithm for multi-robot simultaneous localization and mapping (SLAM). The starting point is the single-robot Rao-Blackwellized particle filter described by Hahnel et al., and three key generalizations are made. First, the particle filter is extended to handle multi-robot SLAM problems in which the initial pose of the robots is known (such as occurs when all robots start from the same location). Second, an approximation is introduced to solve the more general problem in which the initial pose of robots is not known a priori (such as occurs when the robots start from widely separated locations). In this latter case, it is assumed that pairs of robots will eventually encounter one another, thereby determining their relative pose. This relative attitude is used to initialize the filter, and subsequent observations from both robots are combined into a common map. Third and finally, a method is introduced to integrate observations collected prior to the first robot encounter, using the notion of a virtual robot travelling backwards in time. This novel approach allows one to integrate all data from all robots into a single common map.
Dantrolene sodium suspension in treatment of spastic cerebral palsy.

SUMMARY A double-blind study was carried out on 20 children with spasticity secondary to cerebral palsy, in order to compare the effects of dantrolene sodium suspension and a placebo. The drug was found to be physiologically active in reducing the force of muscle contraction, but objective functional improvement, as measured by multiple performance tests, was irregular and probably not significant. RESUME Suspension de dantrolene sodium dans le traitement de l'infirmite motrice cerebrale Une etude en double aveugle a ete entreprise chez 20 enfants IMC spastiques, pour comparer une suspension de dantrolene et un placebo. Le medicament s'est revele physiologiquement actif en reduisant la force de la contraction musculaire, mais l'ameloration fonctionnelle objective, mesuree par de multiples epreuves de performance, a ete irreguliere et probablement non significative. ZUSAMMENFASSUNG Dantrolen Sodium Suspension zur Behandlung der spastischen Cerebralparese Bei 20 Kindern mit einer Spastik aufgrund einer Cerebralparese wurde eine Doppelblindstudie durchgefuhrt, urn die Wirkung von Dantrolen Suspension mit der eines Placebo zu vergleichen. Es stellte sich heraus, das das Medikament physiologisch wirksam war, indem es die Muskelverspannung reduzierte, eine. objektive funktionelle Besserung dagegen war irregular und wahrscheinlich nicht signifikant, was anhand von verschiedenen Tests festgestellt wurde. RESUMEN Suspension de dantrolene sodico en el tratamiento de la paralisis espastica cerebral Se realizo un estudio doble-ciego en 20 ninos con espasticidad secundaria a paralisis cerebral, con el objeto de comparar los efectos de una suspension de dantrolene y un placebo. Se hallo que el farmaco era fisiologicamente activo para reducir la fuerza de la contraction muscular, pero la mejoria funcional objetiva medida por medio de diversos tests, de realization, era irregular y probablemente no significativa.
Application of the tandem thionium/N-acyliminium ion cascade toward heterocyclic synthesis

Many structurally diverse heterocyclic compounds can be easily accessed via the domino Pummerer/cycloaddition/N-acyliminium ion cyclization cascade.
A large scale prediction of bacteriocin gene blocks suggests a wide functional spectrum for bacteriocins

Bacteriocins are peptide-derived molecules produced by bacteria, whose recently-discovered functions include virulence factors and signaling molecules as well as their better known roles as antibiotics. To date, close to five hundred bacteriocins have been identified and classified. Recent discoveries have shown that bacteriocins are highly diverse and widely distributed among bacterial species. Given the heterogeneity of bacteriocin compounds, many tools struggle with identifying novel bacteriocins due to their vast sequence and structural diversity. Many bacteriocins undergo post-translational processing or modifications necessary for the biosynthesis of the final mature form. Enzymatic modification of bacteriocins as well as their export is achieved by proteins whose genes are often located in a discrete gene cluster proximal to the bacteriocin precursor gene, referred to as context genes in this study. Although bacteriocins themselves are structurally diverse, context genes have been shown to be largely conserved across unrelated species. Using this knowledge, we set out to identify new candidates for context genes which may clarify how bacteriocins are synthesized, and identify new candidates for bacteriocins that bear no sequence similarity to known toxins. To achieve these goals, we have developed a software tool, Bacteriocin Operon and gene block Associator (BOA) that can identify homologous bacteriocin associated gene blocks and predict novel ones. BOA generates profile Hidden Markov Models from the clusters of bacteriocin context genes, and uses them to identify novel bacteriocin gene blocks and operons. We provide a novel dataset of predicted bacteriocins and context genes. We also discover that several phyla have a strong preference for bacteriocin genes, suggesting distinct functions for this group of molecules. https://github.com/idoerg/BOA
Semi-global stabilization of minimum phase nonlinear systems in special normal form via linear high-and-low-gain state feedback

We provide an alternative solution to the problem of semi-global stabilization of a class of minimum phase nonlinear systems which is considered in Reference 17. Our method yields a stabilizing linear state feedback law in contrast to a nonlinear state feedback law proposed in Reference 17. We eliminate the peaking phenomenon by inducing a specific time-scale structure in the linear part of the closed-loop system. This time-scale structure consists of a very slow and a very fast time scale. The crucial component in our method is the relation between the slow and the fast time scales. Our proposed linear state feedback control law has a single tunable gain parameter that allows for local asymptotic stability and regulation to the origin for any initial condition in some a priori given (arbitrarily large) bounded set.