cssi/SciSciGPT-SciSciNet huggingface dataset:
Abelian unipotent subgroups of reductive groups

Let G be a connected reductive group defined over an algebraically closed field k of characteristic p>0. The purpose of this paper is two-fold. First, when p is a good prime, we give a new proof of the “order formula” of Testerman for unipotent elements in G; moreover, we show that the same formula determines the p-nilpotence degree of the corresponding nilpotent elements in the Lie algebra of G. Second, if G is semisimple and p is sufficiently large, we show that G always has a faithful representation (ρ,V) with the property that the exponential of dρ(X) lies in ρ(G) for each p-nilpotent . This property permits a simplification of the description given by Suslin et al. of the (even) cohomology ring for the Frobenius kernels . The previous authors already observed that the natural representation of a classical group has the above property (with no restriction on p). Our methods apply to any Chevalley group and hence give the result also for quasisimple groups with “exceptional type” root systems. The methods give explicit sufficient conditions on p; for an adjoint semisimple G with Coxeter number h, the condition p>2h−2 is always good enough.
Closing schools in a shrinking district: Do student outcomes depend on which schools are closed?

Abstract In the last decade, many cities around the country have needed to close schools due to declining enrollments and low achievement. School closings raise concerns about the possible negative impacts on student achievement, neighborhoods, families, and teaching staff. This study examines an anonymous urban district that, faced with declining enrollment, chose to make student achievement a major criterion in determining which schools would be closed. The district targeted low-performing schools in its closure plan, and sought to move their students to higher-performing schools. We estimate the impact of school closures on student test scores and attendance rates by comparing the growth of these measures among students differentially affected by the closures. We use residential assignment to school as an instrument to address non-random sorting of students into new schools. We also statistically control for the contemporaneous effects of other reforms within the district. Results show that students displaced by school closures can experience adverse effects on test scores and attendance, but these effects can be minimized when students move to schools that are higher-performing (in value-added terms). Moreover, the negative effect on attendance disappears after the first year in the new school. Meanwhile, we find no adverse effects on students in the schools that are receiving the transferring students.
Support Vector Machine Classification with Indefinite Kernels

In this paper, we propose a method for support vector machine classification using indefinite kernels. Instead of directly minimizing or stabilizing a nonconvex loss function, our method simultaneously finds the support vectors and a proxy kernel matrix used in computing the loss. This can be interpreted as a robust classification problem where the indefinite kernel matrix is treated as a noisy observation of the true positive semidefinite kernel. Our formulation keeps the problem convex and relatively large problems can be solved efficiently using the analytic center cutting plane method. We compare the performance of our technique with other methods on several data sets.
Coupling of optical lumped nanocircuit elements and effects of substrates

We present here an analytical quasi-static circuit model for the coupling among small nanoparticles excited by an optical electric field in the framework of the optical lumped nanocircuit theory [N. Engheta, A. Salandrino, and A. Alu, Phys. Rev. Lett. 95, 095504 (2005)]. We derive how coupling effects may affect the corresponding nanocircuit model by adding lumped controlled sources that depend on the optical voltages applied on the coupled particles as coupled lumped elements. With the same technique, we may model the presence of a substrate located underneath the nanocircuit elements, relating its presence to the coupling with a properly modeled image nanoparticle. These results are of importance in the understanding and the design of complex optical nanocircuits at infrared and optical frequencies.
Palladium-Catalyzed Synthesis of 9-Fluorenylidenes through Aryne Annulation

The palladium-catalyzed annulation of arynes by substituted o-halostyrenes produces substituted 9-fluorenylidenes in good yields. This methodology provides this important carbocyclic ring system in a single step, which involves the generation of two new carbon−carbon bonds, occurs under relatively mild reaction conditions, and tolerates a variety of functional groups, including cyano, ester, aldehyde, and ketone groups.
On deriving lumped models for blood flow and pressure in the systemic arteries

Windkessel and similar lumped models are often used to represent blood flow and pressure in systemic arteries. The windkessel model was originally developed by Stephen Hales (1733) and Otto Frank (1899) who used it to describe blood flow in the heart. In this paper we start with the one-dimensional axisymmetric Navier-Stokes equations for time-dependent blood flow in a rigid vessel to derive lumped models relating flow and pressure. This is done through Laplace transform and its inversion via residue theory. Upon keeping contributions from one, two, or more residues, we derive lumped models of successively higher order. We focus on zeroth, first and second order models and relate them to electrical circuit analogs, in which current is equivalent to flow and voltage to pressure. By incorporating e ffects of compliance through addition of capacitors, windkessel and related lumped models are obtained. Our results show that given the radius of a blood vessel, it is possible to determine the order of the model that would be appropriate for analyzing the flow and pressure in that vessel. For instance, in small rigid vessels ($R <$ 0.2 cm) it is adequate to use Poiseuille's law to express the relation between flow and pressure, whereas for large vessels it might be necessary to incorporate spatial dependence by using a one-dimensional model accounting for axial variations.
Phase transition and absence of ghosts in rigid QED

Abstract Ordinary QED formulated in the Feynman's space-time picture is equivalent to a one dimensional field theory. In the large N limit there is no phase transition in such a theory. In this letter, we show a phase transition does exist in a generalization of QED characterized by the addition of the curvature of the world line (rigidity) to the Feynman's space-time action. The large distance scale of the disordered phase essentially coincides with ordinary QED, while the ordered phase is strongly coupled. Although rigid QED exhibits the typical pathologies of higher derivative theories at the classical level, we show that both phases of the quantum theory are free of ghosts and tachyons. Quantum fluctuations prevent taking the naive classical limit and inserting the problems of the classical theory.
Concerning the causation of edema in chronic parenchymatous nephritis: Method for its alleviation

0 NE of the most striking clinical manifestations of chronic parenchymatous nephritis is the development of edema or anasarca. Its occurrence is intimately associated with a diminished elimination of salts and water, believed to he due to a reduced power of the kidneys to excrete these substances. Those who have had occasion to observe the condition know well the severe proportions which it may assume, the distress which it causes the patient, and the inadequacy of medicinal treatment or the usual dietetic restrictions. The present communication forms part of a larger study on nephritis begun a number of years ago. Its purpose is to put on record certain facts concerning the nature of the anasarca occurring in chronic parenchymatous nephritis which are of clinical importance and to suggest a new method of treatment which promises to be useful. The reason for selecting this particular phase of the subject is the conviction (gained in the study) that the edema, or anasarca, is one of the most important phenomena in the disease, and that by its alleviation and prevention great progress is made toward ultimate relief of the renal condition. Ever since Bright’s discovery of renal disease the opinion has prevailed that all the phenomena associated with it are attributable to the pathological changes and the disordered function of the kidneys. It is now conceded that the morbid manifestations of chronic parenchymatous nephritis differ from all other forms of renal disease. Its onset, progress, and duration, its tendency to subcutaneous and serous effusions, and the cardiovascular conditions and urinary findings-all differ from those observed in other varieties of renal disease. It is not the object, at present, to discuss the chemical and pathological features of chronic parenchymatous nephritis as a whole, but it is important to note (and the conclusion seems justifiable from the observations thus far made) that among the cases of parenchymatous nephritis there is a group with a constitutional disorder in which the renal and other manifestations are concomitant or secondary in point of development and importance. Much discussion has been indulged in concerning the origin of edema in nephritis, and many theories have been propounded concerning the mode of its production. Thus it was? believed that the edema was the result of a “hydremia” from the retention of water caused by the inability of the kidneys to excrete it. Cohnheim3 supposed that the edema was brought about by an increased permeability of the capillary vessels, induced by the malnutrition or poisoning incidental to the nephritis, which permitted fluid to filter through into the subcutaneous tissues and serous cavities. The hypothesis which has received the soundest clinical confirmation, and still retains man) adherents, is that of Widal” and his associates, which teaches that the kidneys in this disease have a deficient capacity to eliminate salt (sodium chlorid). The accumulation of salt in
Variable block-size interpolative vector quantization

The conventional fixed block-size vector quantization (VQ) usually copes with a small dimension data to alleviate computation load. This technique suffers from the blocking effect at low bit rates. To handle this problem, input data is arranged to form a variable dimension vector so that correlation between two vectors is weak. This paper uses quadtree partitioning to form variable block-size regions. Instead of taking all data of segmented area directly, only constant amount of pixels are selectively subsampled from each terminal node to form an input vector of VQ. With this improvement, only single universal codebook can take care of all kinds of image data. At the decoder, reduced dimension vector will be interpolated back to its full resolution information. Simulation results show that the reconstructed images preserve fine and pleasant qualities in both edge and background regions. The search time for VQ coder also reduces significantly. Furthermore, the comparison of the PSNR of the reconstructed images also reveals better performance of the proposed method than the traditional fixed block-size scheme at low bit rates.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
PRODUCTION NETWORKS AND THE OPEN MACROECONOMY

A key feature of globalization in the current era has been the rapid spread of cross-border production sharing in many regions of the world, including Europe, North America and Asia. The effects of these developments in the context of regional trade integration have been examined in the recent literature. This paper looks at their implications for regional monetary integration and exchange-rate policies. Cross-border production networks and the intra-industry trade associated with them affect exchange-rate behavior, balance of payments adjustment, and the transmission of shocks and disturbances. This paper examines the policy implications of regional production networks that (i) are confined to the countries of a given region, and (ii) involve a dominant extra-regional economy.
Dynamic viscosity of polymer solutions

The dynamic viscosity of different long chain polymers in Aroclor permits an easy extrapolation to zero concentration only in the limiting cases of Newtonian, i. e., constant viscosity at low and high frequency, respectively. The first intrinsic viscosity [η]0 is independent of any concept of the internal viscosity. In the case of polystyrene it is proportional toM 0,65 which shows that Aroclor is a good solvent for this polymer. The second intrinsic viscosity [η]∞ turns out to be independent ofM. It is best reproduced by the model where the internal viscosity resists only the deformation rate of the single link. The displacement rate of more distant beads is affected by the internal viscosity only in the case that it involves the deformation rate of the links. The angles between successive links may be changed at any rate. In the intermediate range of frequencies the extrapolation of the observed dynamic viscosity to the intrinsic value was never made. The experimental data are so much affected by the concentration, i. e., by the interaction of adjacent molecules, that no conclusion may be derived from them about the properties of the isolated macromolecule. A master curve independent ofM andc is obtained by plotting of (G″-ωη ∞)K/c overωτ 1. This means that the deformation mode in the whole molecular weight and concentration range investigated is the same. But this mode is different from that of the independent macromolecule in infinite dilution. The master curve may be described by the excess intrinsic viscosity of the Rouse model with the internal viscosity acting either between the beads on the same link only or between any distinct beads. As a consequence of the concentration effects, however, no conclusions about the properties of the single molecule can be derived from such an agreement.
Incidence and risk factors of bisphosphonate-associated osteonecrosis of the jaws.

Background Intravenous bisphosphonate therapy has been used for treatment of benign and malignant bone diseases and has been linked to osteonecrosis of the jaws. Methods Records of 638 patients treated with intravenous bisphosphonates were reviewed. Drug used, number of infusions, dosing interval, dosage, duration, and occasion of osteonecrosis, diagnosed by history and physical examination, were analyzed. Results The overall incidence of osteonecrosis was 0.94% (6/638). No significant relationship was observed between the incidence of osteonecrosis and demographic parameters, primary tumor, cumulative drug dose, or dosing interval. However, patients who developed osteonecrosis had a significantly greater mean number of infusions (p = .016) and significantly greater mean hours of infusion time (p = .0036). Conclusions The findings suggest positive correlation between the development of osteonecrosis and drug exposure as measured by number of infusions and total infusion hours. However, the relatively low incidence of osteonecrosis precluded definition of a direct dose–response relationship. © 2008 Wiley Periodicals, Inc. Head Neck, 2009
Managing periodically updated data in relational databases: a stochastic modeling approach

Recent trends in information management involve the periodic transcription of data onto secondary devices in a networked environment, and the proper scheduling of these transcriptions is critical for efficient data management. To assist in the scheduling process, we are interested in modeling data obsolescence, that is, the reduction of consistency over time between a relation and its replica. The modeling is based on techniques from the field of stochastic processes, and provides several stochastic models for content evolution in the base relations of a database, taking referential integrity constraints into account. These models are general enough to accommodate most of the common scenarios in databases, including batch insertions and lifespans both with and without memory. As an initial "proof of concept" of the applicability of our approach, we validate the insertion portion of our model framework via experiments with real data feeds. We also discuss a set of transcription protocols that make use of the proposed stochastic model.
Calix[4]pyrroles: versatile molecular containers with ion transport, recognition, and molecular switching functions

Over the last two decades, calix[4]pyrroles have attracted considerable attention as molecular containers. Used in this capacity, they have been exploited as strong and selective receptors and as extractants for both anions and ion pairs. More recently, calix[4]pyrroles have found application as carriers, systems capable of transporting ions and ion pairs across lipophilic membranes. The use of calix[4]pyrroles as building blocks for the preparation of stimulus-responsive material has also been demonstrated. In this latter context, as well as others, the conformational switching, from 1,3-alternate to cone upon anion binding has been exploited to control both structure and substrate binding. In this Review, we describe recent results involving the use of calix[4]pyrrole systems for ion transport. Also summarised is work devoted to the formation of higher order supramolecular aggregates and studies of their response to external stimuli. Taken together, these examples serve to highlight new uses of calix[4]pyrroles as molecular containers.
Primordial non-Gaussianity and Dark Energy constraints from Cluster Surveys

Galaxy cluster surveys will be a powerful probe of dark energy. At the same time, cluster abundance is sensitive to any non-Gaussianity of the primordial density field. It is therefore possible that non-Gaussian initial conditions might be misinterpreted as a sign of dark energy or at least degrade the expected constraints on dark energy parameters. To address this issue, we perform a likelihood analysis of an ideal cluster survey similar in size and depth to the upcoming South Pole Telescope survey and Dark Energy Survey. We analyze a model in which the strength of the non-Gaussianity is parameterized by the constant fNL; this model has been used extensively to derive cosmic microwave background (CMB) anisotropy constraints on non-Gaussianity, allowing us to make contact with those works. We find that the constraining power of the cluster survey on dark energy observables is not significantly diminished by non-Gaussianity, provided that cluster redshift information is included in the analysis. We also find that even an ideal cluster survey is unlikely to significantly improve current and future CMB constraints on non-Gaussianity. However, when all systematics are under control, such surveys could constitute a valuable cross-check on CMB observations.
The K-level crossings of a random algebraic polynomial with dependent coefficients

Abstract For a random polynomial with standard normal coefficients, two cases of the K -level crossings have been considered by Farahmand. For independent coefficients, Farahmand derived an asymptotic value for the expected number of level crossings, even if K grows to infinity. Alternatively, he showed that coefficients with a constant covariance have half as many crossings. Given these results, the purpose of this paper is to study the behavior for dependent standard normal coefficients where the covariance is decaying. Using similar techniques to Farahmand, we will show that for a wide range of covariance functions behavior similar to the independent case can be expected.
SkyDOT (Sky Database for Objects in the Time Domain): a virtual observatory for variability studies at LANL

The mining of Virtual Observatories (VOs) is becoming a powerful new method for discovery in astronomy. Here we report on the development of SkyDOT (Sky Database for Objects in the Time domain), a new Virtual Observatory, which is dedicated to the study of sky variability. The site will confederate a number of massive variability surveys and enable exploration of the time domain in astronomy. We discuss the architecture of the database and the functionality of the user interface. An important aspect of SkyDOT is that it is continuously updated in near real time so that users can access new observations in a timely manner. The site will also utilize high level machine learning tools that will allow sophisticated mining of the archive. Another key feature is the real time data stream provided by RAPTOR (RAPid Telescopes for Optical Response), a new sky monitoring experiment under construction at Los Alamos National Laboratory (LANL).
Inflation and stabilization in Latvia: 1918–1922

Abstract The central European stabilization efforts of the interwar period, based on fiscal cuts coupled with the adoption of a pegged exchange rate and external support are often portrayed as prototypes defining the necessary conditions for successful stabilizations. While prevalent, the orthodox package was not universal in the period. We examine one exception, the Latvian stabilization of 1921–1922. Commencing from a background of multiple circulating currencies, the stabilization program was money-based, implemented without external assistance and followed rather than accompanied by exchange rate stabilization.
Inoculation strategies for victims of viruses and the sum-of-squares partition problem

We propose a simple game for modeling containment of the spread of viruses in a graph of n nodes. Each node must choose to either install anti-virus software at some known cost C, or risk infection and a loss L if a virus that starts at a random initial point in the graph can reach it without being stopped by some intermediate node. We prove many game theoretic properties of the model, including an easily applied characterization of Nash equilibria, culminating in our showing that a centralized solution can give a much better total cost than an equilibrium solution. Though it is NP-hard to compute such a social optimum, we show that the problem can be reduced to a previously unconsidered combinatorial problem that we call the sum-of-squares partition problem. Using a greedy algorithm based on sparse cuts, we show that this problem can be approximated to within a factor of O(log1.5 n).
Development of an objective tool for the diagnosis of myxedema coma.

Myxedema coma, a rare entity, with a reported 25%–65% mortality had no objective criteria for making the diagnosis when we began our study. We developed an objective screening tool for myxedema coma to more easily identify patients and examine the best treatment method in future prospective studies to reduce the mortality of this entity. We conducted a retrospective chart review to find all patients aged ≥18 years admitted with myxedema coma from January 1, 2005 through June 13, 2010 at Indiana University Health Methodist Hospital. On the basis of both our retrospective chart review and on literature accounts, we identified 6 criteria to diagnose myxedema coma. We identified 10 patients initially diagnosed with myxedema coma and established a control group consisting of 13 patients identified with altered mental status and increased thyroid-stimulating hormone (TSH) levels. The 6 variables we created for the screening tool were heart rate, temperature, Glasgow coma scale, TSH, free thyroxine, and precipitating factors. The screening tool has a sensitivity and specificity of about 80%. We ran a logistic regression model using the 10 study patients and 13 controls with the 6 variables. No variables alone significantly contributed to the model. However, the overall model was highly significant ( P = 0.012), providing strong support for a scoring system that uses these variables simultaneously. This screening tool enables physicians to rapidly diagnose myxedema coma to expedite treatment. A more refined diagnostic tool may be used in future clinical studies designed to determine the optimal treatment.
Old Technology Meets New Technology: Complementarities, Similarities, and Alliance Formation

Alliance formation is commonplace in many high-technology industries experiencing radical technological change, where established firms use alliances with new entrants to adapt to technological change, while new entrants benefit from the ability of established players to commercialize the new technology. Despite the prevalence of these alliances, we know little about how these firms choose to ally with specific firms given the range of possible partners they may choose from. This study explores factors that lead to alliance formation between pharmaceutical and biotechnology companies. We focus on the alliance tie as the unit of analysis and argue that dyadic complementarities and similarities directly influence alliance formation. We then introduce a contingency model in which the positive effect of complementarities and similarities on alliance formation is moderated by the age of the new technology firm. We draw theoretical attention to the intersection between levels of analysis, in particular, the intersection between dyadic and firm-level constructs. We find that a pharmaceutical and a biotechnology firm are more likely to enter an alliance based on complementarities when the biotechnology firm is younger. Another noteworthy contribution is the finding that proxies for broad capabilities appear to be at least as, if not more, effective in predicting alliance formation compared to fine-grained science and technology-related indicators, like patent cross citations or patent common citations. We conclude by suggesting that future studies on alliance formation need to take into account interactions across levels; for example, how dyadic capabilities interact with firm-level factors.
Motility during fertilization

Until recently, almost all studies of cell motility at fertilization focused on the activity of the sperm. However, an elaborate and rapidly changing array of cytoskeletal components has been discovered in eggs, leading to speculations regarding the active participation of the egg at fertilization. In addition to answering fundamental questions regarding the mechanisms of fertilization, the egg cytoskeleton during fertilization is proving to be a unique model in which to investigate cellular motility and the molecular characteristics of the cytoskeleton.
Natural history of hepatitis C

It is now widely accepted that 85% or more of individuals with acute hepatitis C virus (HCV) infection progress to chronic hepatitis, and chronic hepatitis C is a known risk factor for cirrhosis and hepatocellular carcinoma (HCC). However, there has been much controversy about the inevitability of developing cirrhosis and HCC and the time frames in which they are likely to occur. Natural history studies have provided varying estimates of the risk of progression in chronic hepatitis C. Part of this variation may be a result of viral-specific, host, and/or environmental factors, but much of it undoubtedly is a result of the difficulties of doing natural history studies in this disease: acute onset is rarely identified, chronic infection is often asymptomatic, and the duration of disease is prolonged. Three types of studies--prospective, retrospective, and retrospective-prospective (nonconcurrent prospective)--have attempted to determine the clinical outcomes of chronic HCV infection and have provided widely varying estimates. The combined population data indicate that the disease progresses slowly over approximately 30 years, on average. Approximately 20% of infected individuals will progress to fibrosis and cirrhosis. Of these, approximately 20% will progress to HCC. The likelihood of progression appears to be independent of genotype or viral load but increases with alcohol intake, male sex, age over 40 years at infection, and coinfection with human immunodeficiency virus (HIV) or hepatitis B virus (HBV). Results of ongoing nonconcurrent studies are needed to determine disease progression in the third, fourth, and fifth decades of infection and to better define the factors that affect progression.
Effects of random phase changes on the formation of synthetic aperture radar imagery

The effects of Gaussian random and linear phase change on the response of the matched azimuth processor of a synthetic aperture imaging radar is analyzed numerically.
Calculating the topography of a differentiated Vesta

[1] Previous examination of the topography of a homogenous Vesta revealed an immense, seemingly abnormal impact crater near the south pole of the asteroid. The crater appeared anomalously shallow, with an extremely tall central peak, suggesting an unusual formation or subsequent modification. Conversely, Vesta is almost certainly differentiated, and we incorporate this notion to reexamine its topography. We find that the central peak is well below the crater rim and that the overall depth of the crater increases, giving it a more ordinary profile. The large density contrast between the metallic core and the overlying silicate layers has the strongest control on the topography. As previously discussed, the location of the crater at the south pole suggests polar wander, necessitating a mechanical structure that allows reorientation of Vesta's large rotational bulge yet preserves the crater's shape, a possibly restrictive scenario. NASA's Dawn spacecraft may observe tectonics consistent with polar wander.
Contract and Game Theory: Basic Concepts for Settings with Finite Horizons

This paper examines a general model of contract in multi-period settings with both external and self-enforcement. In the model, players alternately engage in contract negotiation and take individual actions. A notion of contractual equilibrium, which combines a bargaining solution and individual incentive constraints, is proposed and analyzed. The modeling framework helps identify the relation between the manner in which players negotiate and the outcome of the long-term contractual relationship. In particular, the model shows the importance of accounting for the self-enforced component of contract in the negotiation process. Examples and guidance for applications are provided, along with existence results and a result on a monotone relation between “activeness of contracting” and contractual equilibrium values.
Reactions of Ir(CO)(H)(P(p-tolyl)3)3 with SO2 and O2 Mixtures and with H2SO4, Formation of a Sulfate-Bridged Dimer, and Crystal and Molecular Structure of Ir(CO)(H)(SO2)(P(p-tolyl)3)2

Reactions of HIr(CO)(P(p-tolyl)3)3 with SO2, O2, mixtures of SO2 and O2, and H2SO4 are described. Reactions with mixtures of SO2/O2 and with H2SO4 lead to a common product, Ir2H4(μ-SO4)(P(p-tolyl)3...
A Fourier-Analytic Approach to Reed–Muller Decoding

We present a Fourier-analytic approach to list-decoding Reed-Muller codes over arbitrary finite fields. We use this to show that quadratic forms over any field are locally list-decodable up to their minimum distance. The analogous statement for linear polynomials was proved in the celebrated works of Goldreich Previously, tight bounds for quadratic polynomials were known only for q = 2 and 3; the best bound known for other fields was the Johnson radius. Departing from previous work on Reed-Muller decoding which relies on some form of self-corrector, our work applies ideas from Fourier analysis of Boolean functions to low-degree polynomials over finite fields, in conjunction with results about the weight-distribution. We believe that the techniques used here could find other applications, we present some applications to testing and learning.
On the asymptotic performance of iterative decoders for product codes

We consider hard-decision iterative decoders for product codes over the erasure channel, which employ repeated rounds of decoding rows and columns alternatingly. We derive the exact asymptotic probability of decoding failure as a function of the error-correction capabilities of the row and column codes, the number of decoding rounds, and the channel erasure probability. We examine both the case of codes capable of correcting a constant amount of errors, and the case of codes capable of correcting a constant fraction of their length
Carbonylation of dialkylcyanocuprates with carbon monoxide: Synthesis of α-hydroxyketones

Dialkylcyanocuprates, prepared from copper(l) cyanide and the corresponding alkyllithium or Gringard reagents, readily react with carbon monoxide in the presence of tri-n-butylphosphine at −78 °C in THF to give α-hydroxyketones in high yields (65–85%).
Travel and the emergence of infectious diseases.

Travel is a potent force in the emergence of disease. Migration of humans has been the pathway for disseminating infectious diseases throughout recorded history and will continue to shape the emergence, frequency, and spread of infections in geographic areas and populations. The current volume, speed, and reach of travel are unprecedented. The consequences of travel extend beyond the traveler to the population visited and the ecosystem. When they travel, humans carry their genetic makeup, immunologic sequelae of past infections, cultural preferences, customs, and behavioral patterns. Microbes, animals, and other biologic life also accompany them. Today’s massive movement of humans and materials sets the stage for mixing diverse genetic pools at rates and in combinations previously unknown. Concomitant changes in the environment, climate, technology, land use, human behavior, and demographics converge to favor the emergence of infectious diseases caused by a broad range of organisms in humans, as well as in plants and animals. Many factors contribute to the emergence of infectious diseases. Those frequently identified include microbial adaptation and change, human demographics and behavior, environmental changes, technology and economic development, breakdown in public health measures and surveillance, and international travel and commerce (1-4). This paper will examine the pivotal role of global travel and movement of biologic life in the emergence of infectious diseases. It will also examine the ways in which travel and movement are inextricably tied at multiple levels to other processes that influence the emergence of disease. Travel is a potent force in disease emergence and spread (5). The current volume, speed, and reach of travel are unprecedented. The consequences of migration extend beyond the traveler to the population visited and the ecosystem (6). Travel and trade set the stage for mixing diverse genetic pools at rates and in combinations previously unknown. Massive movement and other concomitant changes in social, political, climatic, environmental, and technologic factors converge to favor the emergence of infectious diseases. Disease emergence is complex. Often several events must occur simultaneously or sequentially for a disease to emerge or reemerge (Table 1) (6). Travel allows a potentially pathogenic microbe to be introduced into a new geographic area; however, to be established and cause disease a microbe must survive, proliferate, and find a way to enter a susceptible host. Any analysis of emergence must look at a dynamic process, a sequence of events, a milieu, or ecosystem. Movement, changing patterns of resistance and vulnerability, and the emergence of infectious diseases also affect plants, animals, and insect vectors.
Ion-implantation doping of strained-layer superlattices

Abstract Strained-layer superlattices (SLSs) are a novel class of electronic materials whose bandgap and transport properties can be tailored during growth by the selection of appropriate layer thickness and chemical composition. Localized doping of III–V compound semiconductor SLSs can be achieved by masked ion implantation followed by controlled atmosphere annealing. Electrical activation of the implanted species and survival of the host superlattice can be detected by Raman spectroscopy; these conclusions are reinforced by a variety of complementary measurements. Values for dopant electrical activation and mobilities in the implantation-doped SLSs are consistent with those obtained for similar implants and anneals in the nearest binary compounds semiconductors. These results reflect favorably on the stability of strained-layer superlattices and allow exploitation of the unique properties of strained-layer superlattices in novel electronic devices.
Boron and boron carbide by vapor deposition

Abstract Boron trichloride can be reduced by hydrogen at 1,300°C with a recovery of approximately 85% as elemental boron. The optimum H2 to BCl3 molar ratio was 30 under the test conditions used. No reaction between tungsten substrates and the boron deposits could be detected. Other substrate materials tested, in order of increasing reactivity with the depositing boron, were fused silica, mullite, graphite, titanium and nickel. Alumina reacted extensively with the chloride gases to form aluminum chloride. BBr3 can be reduced by hydrogen at slightly lower temperatures than can BCl3, but this advantage is probably outweighed by the lower boron content, lower volatility and higher cost of BBr3. When stoichiometric amounts of BCl3 and CH4 were reacted with an excess of H2 at 1,300°C, B4C deposits were obtained. An excess of CH4 in the reaction mixture resulted in the codeposition of B4C and free carbon. B4C deposits contained 74.7 to 76.0% boron, compared with 78.3% for pure B4C. The specific gravity of the B4C was 2.32, which is 90% or more of the theoretical value. The Knoop microhardness of one B4C deposit on a mullite substrate was 3,472. A method of etching B4C was developed and used. Etching revealed that the B4C deposits had a columnar microstructure with the columns perpendicular to the substrate. When BCl3 was reduced with H2 at 1,500°C with a graphite substrate, the depositing boron reacted with the graphite to produce uniform, strongly adherent coatings of B4C on graphite. The Knoop microhardness of two of these B4C coatings was 3,065 and 3,195, which corresponds to a Mohs hardness of approximately 9. Graphite coated with B4C has many physical and chemical properties that would be desirable in rocket nozzle applications.
Macro-to-Micro Interface for the Control of Cellular Organization

The spatial organization of cellular communities plays a fundamental role in determining intercellular communication and emergent behavior. Few tools, however, exist to modulate tissue organization at the scale of individual cells, particularly in the case of dynamic manipulation. Micromechanical reconfigurable culture achieves dynamic control of tissue organization by culturing adherent cells on microfabricated plates that can be shifted to reorganize the arrangement of the cells. Although biological studies using this approach have been previously reported, this paper focuses on the engineering of the device, including the mechanism for translating manual manipulation to precise microscale position control, fault-tolerant design for manufacture, and the synthetic-to-living interface.
MODELING SOLVENT EXTRACTION SYSTEMS WITH SXFIT

SXFIT is the latest in a series of programs designed to model solvent extraction systems of increasing complexity. Unlike its predecessors, SXFIT permits the user complete freedom to define the constituents from which the composition of each phase is to be specified in the data and from which all species of a model for a system are to be formed. This paper describes the manner in which the physical chemistry of the nonaqueous and aqueous solutions involved has come to be treated in this modelling effort. Included are: (1) solute activity coefficients and solvent activity in the nonaqueous phase, estimated by the Scatchard-Hildebrand-Scott treatment; (2) the effect of ionization on these quantities; (3) solute activity coefficients and water activity in the aqueous phase, estimated by the Pitzer treatment; (4) the effect of non ideal behavior on the total concentration of nonaqueous solute species as rendered by a vapor pressure osmometer; (5) a similar treatment of heats of mixing of nonaqueous solutions;...
Simulation of the 1980 eruption of Mount St. Helens using the ash-tracking model PUFF

Abstract The dispersal of volcanic ash from the May 18, 1980 eruption of Mount St. Helens (MSH) has been simulated using the Lagrangian ash-tracking model PUFF. Previous applications of the model were limited to smaller, short-lived eruptions with ash dispersal occurring mainly within the troposphere. Two high-resolution atmospheric reanalysis datasets (ERA-40 and NCEP/NCAR-40) allowed MSH ash cloud dispersal to be simulated up to 30 km elevation. The 1980 eruption was divided into two distinct eruptive phases, (1) an initial, relatively short-lived blast/surge phase that injected ash up to 30 km and (2) a subsequent nine-hour plinian phase that maintained an average eruption column height of 16 km. Using PUFF, the two phases of the MSH eruption were modeled separately based on a range of individual input parameters and then combined to produce an integrated simulation of the entire eruption. The trajectory and areal extent of the modeled atmospheric ash cloud best match the actual distribution of MSH ash when input parameters are set to values inferred from satellite and radar data collected on May 18, 1980. The prevailing wind field exerts the strongest control on the advection and ultimate position of the modeled ash cloud, making the maximum column height and the vertical distribution of ash the most sensitive of the PUFF input parameters for this event. The results indicate that the PUFF model works well at simulating the dispersal of ash injected well into the lower stratosphere from a moderate, relatively long-lived eruption, such as MSH. However, attempts to use PUFF to recreate some granulometric aspects of the MSH fallout deposit, such as the maximum particle size as a function of distance from source, were not successful. PUFF consistently predicts much greater fallout distances for small ash particles (
Density and completeness of subvarieties of moduli spaces of curves or Abelian varieties

Let $V$ be a subvariety of codimension $\leq g$ of the moduli space $\cA_g$ of principally polarized abelian varieties of dimension $g$ or of the moduli space $\tM_g$ of curves of compact type of genus $g$. We prove that the set $E_1(V)$ of elements of $V$ which map onto an elliptic curve is analytically dense in $V$. From this we deduce that if $V \subset \cA_g$ is complete, then $V$ has codimension equal to $g$ and the set of elements of $V$ isogenous to a product of $g$ elliptic curves is countable and analytically dense in $V$. We also prove a technical property of the conormal sheaf of $V$ if $V \subset \tM_g$ (or $\cA_g$) is complete of codimension $g$.
A modular approach to shared-memory consensus, with applications to the probabilistic-write model

We show that consensus can be solved by an alternating sequence of adopt-commit objects (Gafni in Proceedings of the seventeenth annual ACM symposium on principles of distributed computing, pp 143–152, 1998; Alistarh et al. in ISAAC, Lecture notes in computer science, vol 5878. Springer, Berlin, pp 943–953, 2009), which detect agreement, and conciliators, which ensure agreement with some probability. We observe that most known randomized consensus algorithms have this structure. We give a deterministic implementation of an m-valued adopt-commit object for an unbounded number of processes that uses lg m + Θ(log log m) space and individual work. We also give a randomized conciliator for any number of values in the probabilistic-write model with n processes that guarantees agreement with constant probability while using one multi-writer register, O(log n) expected individual work, and Θ(n) expected total work. Combining these objects gives a consensus protocol for the probabilistic-write model that uses O(log m + log n) individual work and O(n log m) total work. No previous protocol in this model uses sublinear individual work or linear total work for constant m.
MCM-41-supported Co-Mo catalysts for deep hydrodesulfurization of light cycle oil

Abstract Light cycle oil (LCO), a by-product of the fluid catalytic cracking (FCC) process in a petroleum refinery, can be used as a blendstock for the production of diesel and jet fuels. Regulatory and operational issues result in need for new and more active catalysts for the deep hydrodesulfurization (HDS) of diesel feedstocks, such as LCO. This paper reports the activity of a mesoporous molecular sieve MCM-41-supported Co-Mo catalyst in comparison to a commercial γ-alumina (Al2O3)-supported Co-Mo catalyst for the desulfurization of a LCO with a sulfur content of 2.19 wt.%. The HDS of dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene—polyaromatic sulfur compounds present in LCO—and their relative reactivities in terms of conversion were examined as a function of time on stream in a fixed-bed flow reactor. The MCM-41-supported catalyst demonstrates consistently higher activity for the HDS of the refractory dibenzothiophenic sulfur compounds, particularly 4,6-dimethyldibenzothiophene. The presence of a large concentration of aromatics in LCO appears to inhibit the HDS of the substituted dibenzothiophenes.
Magnification ratio of the fluctuating light in gravitational lens 0957 + 561

Radio observations establish the B/A magnification ratio of gravitational lens 0957+561 at about 0.75. Yet, for more than 15 years, the optical magnification ratio has been between 0.9 and 1.12. The accepted explanation is microlensing of the optical source. However, this explanation is mildly discordant with (1) the relative constancy of the optical ratio and (2) recent data indicating possible nonachromaticity in the ratio. To study these issues, we develop a statistical formalism for separately measuring, in a unified manner, the magnification ratio of the fluctuating and constant parts of the light curve. Applying the formalism to the recently published data of Kundic and coworkers, we find that the magnification ratios of fluctuating parts in both the g and r colors agrees with the magnification ratio of the constant part in g band, and tends to disagree with the r-band value. One explanation could be about 0.1 mag of consistently unsubtracted r light from the lensing galaxy G1, which seems unlikely. Another could be that 0957+561 is approaching a caustic in the microlensing pattern.
Application of external fixators for management of charcot deformities of the foot and ankle

External fixators have been used effectively for a variety of traumatic, congenital, and neuromuscular conditions of the lower extremity for many decades. The transition to management of Charcot foot and ankle deformities in the diabetic neuropathic patient is a logical application. External fixation can address the unique challenges in the Charcot foot, including osteoporosis, osteomyelitis, wound healing, and compliance issues. The author's experience has lead to abandoning other methods of fixation in favor of external fixation for most infected and noninfected Charcot deformities of the foot and ankle.
Scalable performance of system S for extract-transform-load processing

ETL (Extract-Transform-Load) processing is filling an increasingly critical role in analyzing business data and in taking appropriate business actions based on the results. As the volume of business data to be analyzed increases and quick responses are more critical for business success, there are strong demands for scalable high-performance ETL processors. In this paper, we evaluate a distributed data stream processing engine called System S for those purposes. Based on the original motivation of building System S as a data stream processing engine, we first perform a qualitative study to see if the programming model of System S is suitable for representing an ETL workflow. Second we did performance studies with a representative ETL scenario. Through our series of experiments, we found that the SPADE programming model and its runtime environment naturally fits the requirements of handling massive amounts of ETL data in a highly scalable manner.