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The calculated transition state structure of 1-iodobutane reacting with DABCO is shown. The kinetic rates of this reaction in several organic solvents and temperatures have been measured along with those of iodomethane reacting with DABCO.

Sustainable operation of pipeline networks for oil and gas transportation requires diagnostics capable of both detection and characterization of pipeline defects in particular corrosion defects. Current defect analysis techniques can identify and characterize the geometric features of metal loss defects or defect clusters such as peak depth, length, and width with limited accuracy. Probabilistic data driven models have also shown an ability to predict error bounds for individual defect characteristics as opposed to overall defect tolerance. The prediction accuracy of the health of a pipeline with metal loss defects such as corrosion can be improved with additional detail in the corrosion surface profile as this affects the burst pressure. This will enable operators to apply more accurate corrosion growth models and simulations that can forecast the reduction in pipeline capacity and facilitate more targeted diagnostic and mitigation plans. To this end, a data-driven workflow is proposed to automate the detection, classification, and surface prediction of external corrosion defects. This combines experimental MFL data and validated MFL simulations and leverages both image-based and physics-informed machine learning methodologies.

Graphical abstract, Highlights • Unique veterinary case involving stenosis and regurgitation of all heart valves. • First case report of quadrivalvular stenosis in veterinary medicine. • No infectious etiologic agents identified on histopathology. • Ultimately a definitive diagnosis was undetermined.

Optimization of thermal transport across the interface of two different materials is critical to micro-/nanoscale electronic, photonic, and phononic devices. Although several examples of compositional intermixing at the interfaces having a positive effect on interfacial thermal conductance (ITC) have been reported, an optimum arrangement has not yet been determined because of the large number of potential atomic configurations and the significant computational cost of evaluation. On the other hand, computation-driven materials design efforts are rising in popularity and importance. Yet, the scalability and transferability of machine learning models remain as challenges in creating a complete pipeline for the simulation and analysis of large molecular systems. In this work we present a scalable Bayesian optimization framework, which leverages dynamic spawning of jobs through the Message Passing Interface (MPI) to run multiple parallel molecular dynamics simulations within a parent MPI job to optimize heat transfer at the silicon and aluminum (Si/Al) interface. We found a maximum of 50% increase in the ITC when introducing a two-layer intermixed region that consists of a higher percentage of Si. Because of the random nature of the intermixing, the magnitude of increase in the ITC varies. We observed that both homogeneity/heterogeneity of the intermixing and the intrinsic stochastic nature of molecular dynamics simulations account for the variance in ITC.

Selective laser sintering methods are workhorses for additively manufacturing polymer-based components. The ease of rapid prototyping also means it is easy to produce illicit components. It is necessary to have a data-calibrated in-situ physical model of the build process in order to predict expected and defective microstructure characteristics that inform component provenance. Toward this end, sintering models are calibrated and characteristics such as component defects are explored. This is accomplished by assimilating multiple data streams, imaging analysis, and computational model predictions in an adaptive Bayesian parameter estimation algorithm. From these data sources, along with a phase-field model, bulk porosity distributions are inferred. Model parameters are constrained to physically-relevant search directions by sensitivity analysis, and then matched to predictions using adaptive sampling. Using this feedback loop, data-constrained estimates of sintering model parameters along with uncertainty bounds are obtained.

Algorithms that estimate the location and magnitude of an atmospheric release using remotely sampled air concentrations typically involve a single chemical or radioactive isotope. A new Bayesian algorithm is presented that makes discrimination between possible types of releases (e.g., nuclear explosion, nuclear power plant, or medical isotope production facility) an integral part of the analysis for samples that contain multiple isotopes. Algorithm performance is demonstrated using synthetic data and correctly discriminated between most release-type hypotheses, with higher accuracy when data are available on three or more isotopes.

Predicting source or background radionuclide emissions is limited by the effort needed to run gas/aerosol atmospheric transport models (ATMs). A high-performance surrogate model is developed for the HYSPLIT4 (NOAA) ATM to accelerate transport simulation through model reduction, code optimization, and improved scaling on high performance computing systems. The surrogate model parameters are a grid of short-duration transport simulations stored offline. The surrogate model then predicts the path of a plume of radionuclide particles emitted from a source, or the field of sources which may have contributed to a detected signal, more efficiently than direct simulation by HYSPLIT4. Termed the Atmospheric Transport Model Surrogate (ATaMS), this suite of capabilities forms a basis to accelerate workflows for probabilistic source prediction and estimation of the radionuclide atmospheric background.

State and parameter estimation of power transmission networks is important for monitoring power grid operating conditions and analyzing transient stability. Wind power generation depends on fluctuating input power levels, which are correlated in time and contribute to uncertainty in turbine dynamical models. The ensemble Kalman filter (EnKF), a standard state estimation technique, uses a deterministic forecast and does not explicitly model time-correlated noise in parameters such as mechanical input power. However, this uncertainty affects the probability of fault-induced transient instability and increased prediction bias. A novel approach is to model input power noise with time-correlated stochastic fluctuations and integrate them with the network dynamics during the forecast. While the EnKF has been used to calibrate constant parameters in turbine dynamical models, the calibration of a statistical model for a time-correlated parameter has not been investigated. In this study, twin experiments on a standard transmission network test case are used to validate our time-correlated noise model framework for state estimation of unsteady operating conditions and transient stability analysis, and a methodology is proposed for the inference of the mechanical input power time-correlation length parameter using time-series data from PMUs monitoring power dynamics at generator buses.

The Koopman operator provides a way to transform a (potentially) nonlinear finite-dimensional dynamical system into an infinite-dimensional linear system by lifting the nonlinear state dynamics into a functional space of observables, where the dynamics are linear. Previous literature has claimed that it is not possible to represent nonlinear dynamics with multiple isolated critical points if the set of observables is finite and contains the state; more precisely, such a set cannot be invariant under the Koopman operator. In this paper, we investigate this claim in more detail and provide an analytical counterexample to disprove it. We also consider the convergence of discrete-time Koopman approximation error to the continuous-time error: we show both how this convergence occurs in general and how it can fail for systems with multiple isolated critical points. In particular, discontinuities in Koopman observables at the boundaries of basins of attraction may cause the continuoustime error to diverge; the discrete-time error also suffers from this as the sampling time step goes to zero.

Laser sintering (LS) is widely used to produce functional polymeric parts; however, the resulting parts are often limited by their porous structure, and performance of the part may be strongly anisotropic. Relating the structural features of parts to build process conditions or powder feedstock has been explored previously. In contrast, little is known regarding how the unique internal structures of LS parts evolve and relate to their performance later in their life cycle, for example, after use in a real-world operating environment. Here, a tightly controlled LS build process and measurement campaign by standard X-ray computed tomography (XCT), supported by high-resolution synchrotron XCT, was used to benchmark the internal microstructure (e.g. porosity) as a function of four different build orientations in printed polyamide-12 (PA-12) parts. The initial performance of the parts after printing was characterized by tensile testing and dynamic mechanical analysis (DMA). Arrays of PA-12 parts in different build orientations were exposed to steam (under pressure) and air across multiple temperature and time points for the purposes of accelerated aging through oxidative and hydrolytic breakdown. Exposing parts to steam dramatically altered the internal microstructure and functional properties such as the glass transition temperature, tensile properties, and damping behavior. Notably, post-aging XCT revealed large microstructural changes after only 40 h of steam treatment relative to the as-printed specimens. Furthermore, pore reorganization and changes in crystallinity occurred regardless of whether the steam temperature was aggressive enough to induce a significant loss in mechanical properties. The build orientation dependence on the aging rate was minimal with the relative trend in performance persisting across most metrics among the different orientations even after aging.

High-yield bond benchmarks are often the major factor considered when evaluating the performance of high-yield bond managers. Levine, Drucker, and Rosenthal show that major indices are sometimes hard to beat and at other times easy to beat, and offer several reasons in support of their contention. The authors discuss the structural differences between the high-yield bond and equity markets as well as the properties of high-yield bond indices that make appropriate benchmarking in the high-yield bond market very challenging. The authors also provide a summary of the inclusion rules of several primary indices used as high-yield bond benchmarks. The conclusion reached by the authors is that the limitations of benchmarks, especially of high-yield benchmarks, should be kept in mind when a high-yield bond fund is compared to a high-yield bond index, and that high-yield bond fund performance is best judged within the context of the investor’s investment guidelines. Because plan sponsors often rely on benchmarks in compensating managers who “beat the benchmark,” in 2009 very few high-yield bond management professionals likely received bonuses despite great performance because they did not beat their benchmarks. In 2008, however, many managers received bonuses despite the high-yield bond market’s 26% loss, because the majority of funds outperformed their benchmarks. Something seems to be amiss. Beating major high-yield bond indices is sometimes difficult and sometimes easy, and plan sponsors should be aware of this phenomenon when compensating managers based upon their performance relative to their benchmarks.

Two of the most important statistical tools for analysis of macroeconomics and growth are the national accounts (encompassing gross domestic product, or GDP) and the multifactor productivity (MFP) statistics, which measure output per unit of combined inputs. Although they share a common accounting framework, in the United States these statistics are compiled by separate agencies—the national accounts by the Bureau of Economic Analysis (BEA) and the productivity statistics by the Bureau of Labor Statistics (BLS). Dale W. Jorgenson and J. Steven Landefeld (2006) identified the expansion and improved integration of the nation’s national accounts and productivity statistics as a high priority of their “new architecture” for the US national accounts. Barbara M. Fraumeni, et al. (2006) developed the first steps toward integrating the national accounts with the productivity statistics by describing the conceptual framework, developing illustrative accounts, and describing differences in source data and methods that require resolution. Our paper builds on that work; we develop a prototype integrated production account for the private business sector. We also discuss the issues that arise in extending the integrated production account to the total US economy, including nonmarket government and nonprofit sectors, and provide illustrative accounts for these sectors. Integration of the national accounts with the MFP statistics will provide data users with a Integrated GDP-Productivity Accounts

We show that modifying a Bayesian data assimilation scheme by incorporating kinematically-consistent displacement corrections produces a scheme that is demonstrably better at estimating partially observed state vectors in a setting where feature information important. While the displacement transformation is not tied to any particular assimilation scheme, here we implement it within an ensemble Kalman Filter and demonstrate its effectiveness in tracking stochastically perturbed vortices., Comment: 26 Pages, 9 figures, 5 tables

The ICP34.5 gene from HSV-2 strain 333 was cloned and, when expressed in Vero cells, enhanced the efficiency and extent of glycoprotein processing of glycoprotein C (gC1), a representative viral glycoprotein, during infection with HSV-1 SP7. The ICP34.5 from HSV-1 SP7 limits the extent and efficiency of viral glycoprotein processing. The ability of the HSV-2 ICP34.5 protein to enhance the efficiency and extent of HSV-1 SP7 glycoprotein processing indicates that modulation of viral glycoprotein processing is also a property of the HSV-2 ICP34.5 protein.

[1] In this study we tested upland hillslope evolution models and constrained the rates of regolith production, colluvial transport, and eolian deposition over geologic time scales in a dated volcanic landscape in northern New Mexico using field measurements of regolith thickness; geochemical analyses of regolith, bedrock, and regional dust; numerical modeling of regolith production and transport; and quantitative analyses of airborne light detection and ranging (lidar) digital elevation models (DEMs). Within this volcanic landscape, many topographically closed basins exist as a result of compressional folding and explosion pitting during eruption. The landscape has evolved from an initial state of no regolith cover at 40 ± 5 ka to its modern state, which has highly weathered regolith ranging from 0 to 3+ m, with local thickness values controlled primarily by topographic position. Our models constrain the maximum rate of regolith production in the study area to be in the range of 0.02 to 0.12 m kyr ! 1 and the rate of colluvial transport per unit slope gradient to be in the range of 0.2 to 2.7 m 2 kyr ! 1 , with higher values in areas with more aboveground biomass. We conclude that a depth! dependent colluvial transport model better predicts the observed spatial distribution of regolith thickness compared to a model that has no depth dependence. This study adds to the database of estimates for rates of regolith production and transport in the western United States and shows how dated landscapes can be used to improve our understanding of the coevolution of landscapes and regolith cover.

This study presents our preliminary experience in multiplanar transesophageal echocardiography. In addition, an attempt was made in one patient to reconstruct the left ventricle in three dimensions using the sequential planes obtained from the multiplanar approach.

Objective: To determine the impact of the introduction of acellular pertussis vaccine for the fourth and fifth doses of the diphtheria and tetanus toxoids and pertussis vaccine series in children on rates of reported vaccine-associated adverse events in the United States. Design: Analysis of postmarketing vaccine adverse event data from the Vaccine Adverse Event Reporting System during the years 1991 to 1993. Population Studied: Approximately 27 million doses of diphtheria and tetanus toxoids and pertussis vaccine and 5 million doses of diphtheria and tetanus toxoids and acellular pertussis vaccine were distributed from 1991 to 1993 to children 15 months to 7 years of age. Main Outcome Measures: Rates of reported fever, seizures, and hospitalizations after pertussis vaccination. Results: Rates of reported adverse events per 100 000 vaccinations were significantly lower after administration of diphtheria and tetanus toxoids and acellular pertussis vaccine than diphtheria and tetanus toxoids and pertussis vaccine for the following outcomes: all reports, 2.9 vs 9.8; fever, 1.9 vs 7.5; seizures, 0.5 vs 1.7; and hospitalizations, 0.2 vs 0.9. Conclusions: These results confirm that minor adverse events are less frequent after administration of the acellular pertussis vaccine. In addition, these data suggested that seizures and hospitalizations associated with pertussis vaccination are less frequent after administration of the acellular pertussis vaccine in age groups for which it is now recommended. (Arch Pediatr Adolesc Med. 1996;150:457-460)

To evaluate the role of adults in the transmission of pertussis during an epidemic, persons presenting with unexplained cough to ambulatory care clinics were evaluated for evidence of pertussis infection. Nasopharyngeal specimens for culture and serum samples for IgG and IgA antibodies to filamentous hemagglutinin and pertussis toxin antigens of Bordetella pertussis were obtained. Thirty-eight adults were enrolled in the study ; 10 (26%) had serologic evidence of B. pertussis infection. Clinical findings were not significantly different among persons with and without evidence of pertussis infection. Pertussis should be considered in the differential diagnosis of persistent cough in all age groups. Future use of new acellular pertussis vaccines in adults may substantially impact the control of the infection.

Echocardiography is an important clinical method for identification and assessment of the entire spectrum of cardiac diseases. Visual assessment of the echocardiograms is tedious and subjective, but on the other hand, owing to the poor quality of the data, the automatic techniques are unreliable. One can minimize these drawbacks through collaborative processing. The authors describe a collaborative method to extract the myocardium from a sequence of two-dimensional echocardiograms. Initially, a morphologically adaptive thresholding scheme generates a rough estimate of the myocardium, and then a collaborative scheme refines the estimate. The threshold is computed at each pixel as a function of the local morphology and a default threshold. The points that have echodensities greater than the threshold form a rough estimate of the myocardium. This is collaboratively refined in accordance with the corrections specified by the operator, through mouse gestures. The gestures are mapped on to an image processing scheme that decides the precise boundaries of the intended regions that are to be added to or deleted from the estimated myocardium.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Integrated machine vision software that combines the ease-of-use of a menu-driven interface with the power of a programming environment enables engineers scientists doctors and other laboratory professionals to prototype and implement full-featured image processing and analysis systems with a minimum investment in time and money. A menu-driven interface permits rapid prototyping with a minimum investment in either machine vision or computer training adding a programming environment permits the flexibility to adapt when necessary. In addition such software runs on a standard hardware platform provides tools for analyzing images both interactively and automatically and offers data gathering and accessibility. New Approach to Machine Vision Application Development Application implementation of machine vision has finally come of age. No longer is it necessary for each application to require a highly trained vision expert to develop and install machine vision and imaging systems. Also gone are the months of software development for implementing even the simplest of applications. All this has been changed by the advent of standard computer machine vision platforms and easy-to-use yet fully functional integrated software tools which allow engineers scientists doctors and other professionals to define prototype and implement complete applications. This development of easy-to-use software tools running on standard platform hardware benefits engineering medical and other scientific professionals in two ways. First standard platform hardware provides them with a familiar environment and a multitude of available peripheral hardware to simplify© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In a rich and stimulating article Professor Gabriel Baer has compared early municipal reform in Alexandria with that in Istanbul.' Both cities were distinguished by a European and Europeanized merchant population familiar with and desirous of Western municipal institutions, services and amenities. While a municipality enjoying a large measure of autonomy was inaugurated in the foreign section of Istanbul in 1858, a similar institution was not introduced in the Egyptian city until 1890. Professor Baer attributes this disparity in municipal development to the difference in 'the response of the diplomatic community in each city to the possible foundation of a municipality. In Alexandria the European consuls perceived municipal reform as a threat to their treaty rights. 'In contrast with other parts of the Ottoman Empire, it was the customary privilege of foreigners in Egypt that no tax whatever could be imposed on them unless it was sanctioned by a specific international convention.'2 Hence the diplomatic community of Alexandria was unwilling to concede the taxing privilege which was a prerequisite to the successful functioning of the new municipality. In addition the consuls feared that since foreigners made up less than one third of the population, 'there would be no guarantee for an adequate representation of the European community.'3 For both these reasons the consular authorities refused to sanction the development of municipal institutions in Alexandria. In Istanbul, according to Professor Baer, the situation was different. Internal taxes could be levied upon Europeans and the area in which municipal reform first took place was inhabited primarily by foreigners. The diplomatic corps could not object to a new internal tax and was presumably less fearful of losing control of a municipality located in a predominantly European area.4 Thus the foreign consuls voiced no objection to the experimental municipality which was inaugurated in the Galata section of Istanbul in July, 1858. In the absence of extensive data dealing with the municipality of Galata, Professor Baer wisely uses the example of municipal reform in Istanbul primarily to set off and contrast his much more extensive data on Alexandria. Recent research in the British and Ottoman Archives and in contemporary journals has produced evidence which demonstrates that the views of municipal reform in Istanbul presented by Professor Baer call for some modification. The difference in municipal development between Alexandria and the Ottoman capital cannot be explained merely by diplomatic opposition in the former and diplomatic acquiescence in the latter. The attitude of the foreign consuls toward municipalities in both cities had much more in common than has hitherto been suspected. In any case both the impetus behind the formation of the experimental municipality and the determina

Ever since it had been recognized that the decay of the Ottoman Empire could not be arrested by traditional methods, foreigners and non-Muslims had played a significant part in the Empire's modernization. The Compte de Bonneval and Baron de Tott were only the most famous of a group of foreign advisers who were employed by the Ottoman government to help reform the military establishment during the eighteenth century. During the Tanzimat era, 1839–1876, when the Porte became irrevocably committed to modernization, foreigners and non-Muslims were employed in a multitude of capacities. They ranged from the Prussian Von Moltke who was to advise on the vital problem of reorganizing the army, to Giuseppe Donnizetti, brother of the composer, who was charged with the somewhat less important task of organizing a Western-style military band.