cssi/SciSciGPT-SciSciNet huggingface dataset:
SEPARATION OF HYDROGEN AND CARBON DIOXIDE USING A NOVEL MEMBRANE REACTOR IN ADVANCED FOSSIL ENERGY CONVERSION PROCESS

Inorganic membrane reactors offer the possibility of combining reaction and separation in a single operation at high temperatures to overcome the equilibrium limitations experienced in conventional reactor configurations. Such attractive features can be advantageously utilized in a number of potential commercial opportunities, which include dehydrogenation, hydrogenation, oxidative dehydrogenation, oxidation and catalytic decomposition reactions. However, to be cost effective, significant technological advances and improvements will be required to solve several key issues which include: (a) permselective thin solid film, (b) thermal, chemical and mechanical stability of the film at high temperatures, and (c) reactor engineering and module development in relation to the development of effective seals at high temperature and high pressure. In this project, we are working on the development and application of palladium and palladium-silver alloy thin-film composite membranes in membrane reactor-separator configuration for simultaneous production and separation of hydrogen and carbon dioxide at high temperature. From our research on Pd-composite membrane, we have demonstrated that the new membrane has significantly higher hydrogen flux with very high perm-selectivity than any of the membranes commercially available. The steam reforming of methane by equilibrium shift in Pd-composite membrane reactor is being studied to demonstrate the potential application this new development. Tomore » have better understanding of the membrane reactor, during this reporting period, we developed a two-dimensional pseudo-homogeneous reactor model for steam reforming of methane by equilibrium shift in a tubular membrane reactor. In numerical solution of the reactor model equations, numerical difficulties were encountered and we seeking alternative solution techniques to overcome the problem.« less
INSTABILITY OF CHARGE ORDERED STATES IN DOPED ANTIFERROMAGNETS

We analyze the induced interactions between localized holes in weakly doped Heisenberg antiferromagnets due to the modification of the quantum zero point spin wave energy; i.e., the analog of the Casimir effect. We show that this interaction is uniformly attractive and falls off as ${r}^{\ensuremath{-}2d+1}$ in $d$ dimensions. For ``stripes,'' i.e., parallel $(d\ensuremath{-}1)$-dimensional hypersurfaces of localized holes, the interaction energy per unit hyperarea is attractive and falls, generically, like ${r}^{\ensuremath{-}d}$. We argue that, in the absence of a long-range Coulomb repulsion between holes, this interaction leads to an instability of any charge-ordered state in the dilute doping limit.
Giant Molecular Clouds in M33. I. BIMA All-Disk Survey

We present the first interferometric 12CO (J = 1 → 0) map of the entire Hα disk of M33. The 13'' diameter synthesized beam corresponds to a linear resolution of 50 pc, sufficient to distinguish individual giant molecular clouds (GMCs). From these data we generated a catalog of 148 GMCs with an expectation that no more than 15 of the sources are spurious. The catalog is complete down to GMC masses of 1.5 × 105 M⊙ and contains a total mass of 2.3 × 107 M⊙. Single-dish observations of CO in selected fields imply that our survey detects ~50% of the CO flux, hence that the total molecular mass of M33 is 4.5 × 107 M⊙, approximately 2% of the H I mass. The GMCs in our catalog are confined largely to the central region (R < 4 kpc). They show a remarkable spatial and kinematic correlation with overdense H I filaments; the geometry suggests that the formation of GMCs follows that of the filaments. The GMCs exhibit a mass spectrum dN/dM ∝ M-2.6±0.3, considerably steeper than that found in the Milky Way and in the LMC. Combined with the total mass, this steep function implies that the GMCs in M33 form with a characteristic mass of ~7 × 104 M⊙. More than 2/3 of the GMCs have associated H II regions, implying that the GMCs have a short quiescent period. Our results suggest the rapid assembly of molecular clouds from atomic gas, with prompt onset of massive star formation.
Chemoenzymatic synthesis of heparan sulfate and heparin

Heparan sulfate (HS) is a highly sulfated polysaccharide that plays essential physiological and pathophysiological functions. The biosynthesis of HS involves a series of specialised sulfotransferases, an epimerase and glycosyl transferases. The availability of these enzymes offers a promising method to prepare HS polysaccharides and structurally defined oligosaccharides. Given the fact that chemical synthesis of large HS oligosaccharides is extremely difficult, preparation of HS using a chemoenzymatic approach has gained momentum. This review article summarises recent progress on the development of a chemoenzymatic approach to prepare HS and HS oligosaccharides.
Enantioselective synthesis of an ent-trichothecene

Abstract A convergent route for the enantioselective synthesis of trichothecenes is described. A key step in the synthetic sequence is an Ireland-Claisen rearrangement that occurs with total facial selectivity and high diastereoselectivity. The relative stereochemistry about the vicinal quaternary centers of the major diastereomer is that of the trichothecene skeleton, but the absolute stereochemistry is opposite to that of the natural products.
Customer Satisfaction with Electronic Service Encounters

Customer relationship management is an integral component of business strategy for on-line service providers. This paper investigates the aspects of on-line transactions in electronic retailing that are most likely to satisfy or dissatisfy customers, thereby increasing or decreasing the likelihood of building and maintaining relationships with them. For this study, 513 respondents reported behaviors, perceptions, beliefs, events, features, characteristics, attributes, and situations that expressed their satisfaction or dissatisfaction with electronic service encounters. Content analysis of these encounters yielded three meta-categories, six categories, and 33 subcategories of customer satisfaction or dissatisfaction with on-line service providers. The findings suggested that three major categories are robust even in the electronic context of the Internet. The antecedents identified were relevant both to product-related services (e.g., books, apparel) and to pure services (e.g., on-line banking, on-line stock trading). The study found that the characteristics and behaviors of customer-contact employees play an important role in on-line service encounters. It also revealed a percentage decrease in satisfactory incidents, a percentage increase in unsatisfactory incidents, and a percentage increase in unsatisfactory incidents involving employee characteristics and behaviors as service encounters move from a bricks-and-mortar environment to an electronic context. This suggests that customer-contact employees may not be well equipped to deal with on-line customers.
Programs to reduce teen pregnancy sexually transmitted infections and associated sexual risk behaviors: a systematic review.

Abstract Purpose This systematic review provides a comprehensive, updated assessment of programs with evidence of effectiveness in reducing teen pregnancy, sexually transmitted infections (STIs), or associated sexual risk behaviors. Methods The review was conducted in four steps. First, multiple literature search strategies were used to identify relevant studies released from 1989 through January 2011. Second, identified studies were screened against prespecified eligibility criteria. Third, studies were assessed by teams of two trained reviewers for the quality and execution of their research designs. Fourth, for studies that passed the quality assessment, the review team extracted and analyzed information on the research design, study sample, evaluation setting, and program impacts. Results A total of 88 studies met the review criteria for study quality and were included in the data extraction and analysis. The studies examined a range of programs delivered in diverse settings. Most studies had mixed-gender and predominately African-American research samples (70% and 51%, respectively). Randomized controlled trials accounted for the large majority (87%) of included studies. Most studies (76%) included multiple follow-ups, with sample sizes ranging from 62 to 5,244. Analysis of the study impact findings identified 31 programs with evidence of effectiveness. Conclusions Research conducted since the late 1980s has identified more than two dozen teen pregnancy and STI prevention programs with evidence of effectiveness. Key strengths of this research are the large number of randomized controlled trials, the common use of multiple follow-up periods, and attention to a broad range of programs delivered in diverse settings. Two main gaps are a lack of replication studies and the need for more research on Latino youth and other high-risk populations. In addressing these gaps, researchers must overcome common limitations in study design, analysis, and reporting that have negatively affected prior research.
Sharp thresholds For monotone properties in random geometric graphs

Random geometric graphs result from taking n uniformly distributed points in the unit cube, [0,1]d, and connecting two points if their Euclidean distance is at most r, for some prescribed r. We show that monotone properties for this class of graphs have sharp thresholds by reducing the problem to bounding the bottleneck matching on two sets of $n$ points distributed uniformly in [0,1]d. We present upper bounds on the threshold width, and show that our bound is sharp for d = 1 and at most a sublogarithmic factor away for d ≥ 2. Interestingly, the threshold width is much sharper for random geometric graphs than for Bernoulli random graphs. Further, a random geometric graph is shown to be a subgraph, with high probability, of another independently drawn random geometric graph with a slightly larger radius; this property is shown to have no analogue for Bernoulli random graphs.
How Bad Are Twins? Output Costs of Currency and Banking Crises

We investigate the output effects of banking and currency crises in emerging markets, focusing on whether “twin crises” entail especially large losses. Recent literature emphasizes the costs of financial crises, and suggests that twin crises are particularly damaging to the real economy. Using a panel data set for 1975–97, we find that currency (banking) crises are very costly, reducing output by about 5%–8% (8%–10%) over a 2–4 year period. The cumulative loss of both types of crises is therefore very large. We do not find, however, additional feedbacks or interactive effects associated with twin crises further damaging the economy.
Access to Justice and Legal Empowerment: A Review of World Bank Practice

This paper reviews the World Bank's existing work in access to justice and suggests directions for further Bank engagement in this area. Accesses to justice efforts are grouped here into six categories: court reforms, legal aid, information dissemination and education, alternative dispute resolution, public sector accountability, and research. The paper is motivated in part by recent discussions of 'legal empowerment;' a thread of inquiry that runs through the review is: how do World Bank efforts to increase access to justice affect the agency of poor people? The paper concludes with insights and recommendations that emerge from the Bank's experience. All justice reform interventions should attend to particularities of sociolegal context, should consider the specific justice needs of poor people, and should be planned not in isolation, but from a system wide perspective. Legal services and legal aid interventions should confront the challenge of scale, should consider alternative methods of service delivery, and should in some cases take care to maintain at least partial independence from the state. The use of non-court dispute resolution mechanisms should be guided by the benefits achieved in cost, time, harmony, and fairness. Evaluations of access to justice programs should go beyond 'headcounts' to demonstrate impact on users of justice services as well as on society at large and to weigh opportunity cost.
Population, projections, and policy: A cautionary perspective

Population projections depend on censuses, vital statistics and sample surveys, all of which have deficiencies that are most marked in the less developed countries (LDCs). Long-range projections by international agencies have recently undergone major revisions, while forecasts of the U.S. population have changed drastically over the past four years. The United Nations typically prepares “high,” “medium” and “low” projections. Even the high projection contains optimistic assumptions about fertility decline, while assumptions of constant or increasing fertility receive no serious attention. The paper suggests that high and constant fertility projections should receive more attention from policy makers, with medium estimates treated more as targets achievable only through considerable programmatic effort. At the same time, economic and social plans should be laid for dealing with the population sizes implied by the “high” variants.
FermiKit: assembly-based variant calling for Illumina resequencing data

Summary: FermiKit is a variant calling pipeline for Illumina whole-genome germline data. It de novo assembles short reads and then maps the assembly against a reference genome to call SNPs, short insertions/deletions and structural variations. FermiKit takes about one day to assemble 30-fold human whole-genome data on a modern 16-core server with 85 GB RAM at the peak, and calls variants in half an hour to an accuracy comparable to the current practice. FermiKit assembly is a reduced representation of raw data while retaining most of the original information. Availability and implementation: https://github.com/lh3/fermikit Contact: gro.etutitsnidaorb@ilgneh
Structure and Electronic Transport in Graphene Wrinkles

Wrinkling is a ubiquitous phenomenon in two-dimensional membranes. In particular, in the large-scale growth of graphene on metallic substrates, high densities of wrinkles are commonly observed. Despite their prevalence and potential impact on large-scale graphene electronics, relatively little is known about their structural morphology and electronic properties. Surveying the graphene landscape using atomic force microscopy, we found that wrinkles reach a certain maximum height before folding over. Calculations of the energetics explain the morphological transition and indicate that the tall ripples are collapsed into narrow standing wrinkles by van der Waals forces, analogous to large-diameter nanotubes. Quantum transport calculations show that conductance through these “collapsedwrinkle” structures is limited mainly by a density-of-states bottleneck and by interlayer tunneling across the collapsed bilayer region. Also through systematic measurements across large numbers of devices with wide “foldedwrink...
Exact reconstruction analysis/synthesis filter banks with time-varying filters

The authors examine some of the analysis/synthesis issues associated with FIR (finite impulse response) time-varying filter banks where the filter bank coefficients are allowed to change in response to the input signal. Several issues are identified as being important for realizing performance gains from time-varying filter banks in image coding applications. These issues relate to the behavior of the filters as transition from one set of filter banks to another occurs. Lattice structure formulations for the time-varying filter bank problems are introduced and discussed in terms of their properties and transition characteristics. >
Supply chain performance measurement: the case of the traditional food sector in the EU

The objective of this study is to develop a sound measurement instrument of traditional food supply chain performance integrating the perspectives of different stakeholders. Therefore first, stakeholders' goals are generalized via focus groups and individual interviews. Second, stakeholders' goals are consolidated, based on their specificity and conflicting/divergent nature and as a result, supply chain goals are developed. Third, potential performance indicators are listed, supporting the developed supply chain goals. Fourth, key performance indicators (KPIs) are selected. As a result, five main supply chain goals are formulated (traditionalism, efficiency, responsiveness, quality and chain balance) together with their supporting performance indicators. Future research should focus on validating the instrument in other food and non-food sectors.
Enhancing Heterogeneous Catalysis through Cooperative Hybrid Organic–Inorganic Interfaces

Active-site/surface cooperativity can enhance heterogeneous organic and organometallic catalysis. We review the powerful role of the solid surface in this context for generating local acidity and, as an inner-sphere ligand, for stabilizing immobilized supramolecular assemblies and unsaturated organometallic complexes that are often unstable in solution.
Physicians and the (Woman's) Body Politic

Alicia Beltran's Kafka-esque pregnancy experience is part of an ongoing struggle in which pregnant women and their physicians are marked for intense attention by legislators and judges acting as arbiters of medical knowledge despite a lack of expertise or detachment.
Pseudo-centrosymmetric matrices, with applications to counting perfect matchings

We consider square matrices A that commute with a fixed square matrix K, both with entries in a field F not of characteristic 2. When K 2 = I, Tao and Yasuda defined A to be generalized centrosymmetric with respect to K. When K 2 = I, we define A to be pseudo-centrosymmetric with respect to K; we show that the determinant of every even-order pseudo-centrosymmetric matrix is the sum of two squares over F, as long as 1 is not a square in F. When a pseudo-centrosymmetric matrix A contains only integral entries and is pseudo-centrosymmetric with respect to a matrix with rational entries, the determinant of A is the sum of two integral squares. This result, when specialized to when K is the even-order alternating exchange matrix, applies to enumerative combinatorics. Using solely matrix-based methods, we reprove a weak form of Jockusch’s theorem for enumerating perfect matchings of 2-even symmetric graphs. As a corollary, we reprove that the number of domino tilings of regions known as Aztec diamonds and Aztec pillows is a sum of two integral squares.
A nash approach to planning merchant transmission for renewable resource integration

Summary form only given. Major transmission projects are needed to integrate and to deliver renewable energy (RE) resources. Cost recovery is a serious impediment to transmission investment. A negotiation methodology is developed in this study to guide transmission investment for RE integration. Built on Nash bargaining theory, the methodology models a negotiation between an RE generation company and a transmission company for the cost sharing and recovery of a new transmission line permitting delivery of RE to the grid. Findings from a six-bus test case demonstrate the Pareto efficiency of the approach as well as its fairness, in that it is consistent with one commonly used definition of fairness in cooperative games, the Nash cooperative solution. Hence, the approach could potentially be used as a guideline for RE investors. The study also discusses the possibility of using RE subsidies to steer the negotiated solution towards a system-optimal transmission plan that maximizes total net benefits for all market participants. The findings suggest that RE subsidies can be effectively used to achieve system optimality when RE prices are fixed through bilateral contracts but have limited ability to achieve system optimality when RE prices are determined through locational marginal pricing. This limitation needs to be recognized in the design of RE subsidies.
A Study of Multiscale Density Fluctuation Measurements

Intriguing parallels between density fluctuation power versus wavenumber on small (in millimeter) and large (in megaparsec) scales are presented. The comparative study is carried out between fusion plasma measurements and cosmological data. Based on predictions from classical fluid turbulence theory, we argue that our observations are consistent with 2-D turbulence. The similar dependencies of density fluctuations on these disparate scales might indicate that primordial turbulence has been expanded to cosmological proportions.
On the design of international environmental agreements for identical and heterogeneous developing countries

I analyze the problem faced by an imperfectly informed supra-national governmental authority (SNGA) that wishes to design an International Environmental Agreement (IEA). The SNGA cannot contract directly with polluting firms in the developing countries (DCs), and it must deal with such firms through their governments. I find that the transfers necessary to induce optimal behavior by governments and firms are sensitive to the timing of the underlying game and to the existence of collusion. This analysis suggests that IEAs are not doomed due to a monitoring and enforcement problem arising from national sovereignty. However, the success of IEAs is contingent on the funds available for environmental protection. Copyright 2000 by Oxford University Press.
Thin film transfer process for low cost MCM-D fabrication

This paper describes a unique, highly flexible cost competitive method to fabricate microelectronic packages that require thin film interconnections. The method involves fabricating thin film metal/polymer structures multi-up on a reusable temporary glass carrier; the thin film stack is transferred later onto product substrates of choice. The final product substrate can be silicon, co-fired alumina or glass-ceramic, aluminum nitride, diamond, or a printed wiring board. Optionally, one can also use the released thin film decal as a flexible high wireability interconnect by itself, as an interposer, or in applications like wafer level testing for known good die (KGD). The thin film wiring structure can be fabricated multi-up on a standardized form factor carrier (independent of the characteristics of the final product substrate) in a thin film interconnect foundry, thus significantly reducing cost both from the economies of scale and full utilization of the thin film factory for a variety of customer needs. >
Planning Aims for a Network of Horizontal and Overhead Sensors

This paper considers the problem of planning sensor observations for a network of overhead sensors which will resolve ambiguities in the output of a horizontal sensor network. Specifically, we address the problem of counting the number of objects detected by the horizontal sensor network, using the overhead network to aim at specific areas to improve the count. The main theme of our results is that, even though observation planning is intractable for such a network, a simple, greedy algorithm for controlling the overhead sensors guarantees performance with bounded and reasonable suboptimality. Our results are general and make few assumptions about the specific sensors used. The techniques described in this paper can be used to plan sensor aims for a wide variety of sensor types and counting problems.
Delivery horizon and grain market volatility

We study the difference in the volatility dynamics of CBOT corn, soybeans, and oats futures prices across different delivery horizons via a smoothed Bayesian estimator. We find that futures price volatilities in these markets are affected by inventories, time to delivery, and the crop progress period and that there are important differences in the effects across delivery horizons. We also find that price volatility is higher before the harvest starts in most cases compared to the volatility during the planting period. These results have implications for hedging, options pricing, and the setting of margin requirements. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark 30:846–873, 2010
Mechanism of Posterior Semicircular Canal Stimulation in Patients with Benign Paroxysmal Positional Vertigo

A quantitative study of the stimuli and vestibulo-ocular response associated with benign paroxysmal positional vertigo (BPPV) was made to test and further develop the canalithiasis theory of BPPV. The angular velocities of the head in the planes of the semicircular canals during the Dix-Hallpike test were measured in four healthy subjects using electromagnetic sensors to record the position of the head in a six degrees of freedom paradigm. Next, the nystagmus reactions in seven patients diagnosed with idiopathic BPPV were recorded with video-oculography. The characteristics of the vestibulo-ocular reflex (VOR) response were analyzed using three-dimensional vector techniques. The angular velocity of the head was primarily, but not exclusively, in the plane of the posterior semicircular canal (PSC) in question. Both the anterior and horizontal canals were also stimulated by a lesser degree. The duration of the motion stimulus in the PSC was <1.3 s with peak angular velocities of 150 deg/s. The eye respon...
Observations of Coronal Mass Ejections with the Coronal Multichannel Polarimeter

The Coronal Multichannel Polarimeter (CoMP) measures not only the polarization of coronal emission, but also the full radiance profiles of coronal emission lines. For the first time, CoMP observations provide high-cadence image sequences of the coronal line intensity, Doppler shift, and line width simultaneously over a large field of view. By studying the Doppler shift and line width we may explore more of the physical processes of the initiation and propagation of coronal mass ejections (CMEs). Here we identify a list of CMEs observed by CoMP and present the first results of these observations. Our preliminary analysis shows that CMEs are usually associated with greatly increased Doppler shift and enhanced line width. These new observations provide not only valuable information to constrain CME models and probe various processes during the initial propagation of CMEs in the low corona, but also offer a possible cost-effective and low-risk means of space-weather monitoring.
The Relation of Cumulative Demographic Risk to Mothers' Responsivity and Control: Examining the Role of Toddler Temperament.

The relations of cumulative demographic risk and children's temperament to mothers' parenting behaviors were examined when children were 18 (T1, n = 247) and 30 (T2, n = 216) months of age. Mothers...
Higgs Production in Association with Bottom Quarks at Hadron Colliders

We review the present status of the QCD corrected cross-sections and kinematic distributions for the production of a Higgs boson in association with bottom quarks at the Fermilab Tevatron and CERN Large Hadron Collider. Results are presented for the Minimal Supersymmetric Standard Model where, for large tan β, these production modes can be greatly enhanced compared to the Standard Model case. The next-to-leading order QCD results are much less sensitive to the renormalization and factorization scales than the lowest order results, but have a significant dependence on the choice of the renormalization scheme for the bottom quark Yukawa coupling. We also investigate the uncertainties coming from the Parton Distribution Functions and find that these uncertainties can be comparable to the uncertainties from the remaining scale dependence of the next-to-leading order results. We present results separately for the different final states depending on the number of bottom quarks identified.
A compact inverse velocity solution for redundant robots

A compact inverse rate kinematics solution for serial-chain, redundant, n-jointed robots is presented. The serial-chain inverse rate kinematics problem is dual to the inverse statics problem in in-parallel systems such as cooperating robots, in which the task of distributing the load wrench between multiple subsystems is typically underspecified. Therefore, methods for obtaining the wrench distribution in an in-parallel system can be applied to the underconstrained inverse kinematics problem for serial-chain manipulators. In particular, a solution that minimizes a weighted-norm of the joint rates vector is derived in this article. The advantages of this method are the ability to accommodate any type of joint and the availability of analytical, closed-form solutions for the joint rates. Finally, a geometric interpretation of the solution is provided using screw system theory.
GENERALIZED SUPERMARTINGALE DEFLATORS UNDER LIMITED INFORMATION

We undertake a study of markets from the perspective of a financial agent with limited access to information. The set of wealth processes available to the agent is structured with reasonable economic properties, instead of the usual practice of taking it to consist of stochastic integrals against a semimartingale integrator. We obtain the equivalence of the boundedness in probability of the set of terminal wealth outcomes (which in turn is equivalent to the weak market viability condition of absence of arbitrage of the first kind) with the existence of at least one strictly positive deflator that makes the deflated wealth processes have a generalized supermartingale property.
Dyson Indices and Hilbert-Schmidt Separability Functions and Probabilities

A confluence of numerical and theoretical results leads us to conjecture that the Hilbert-Schmidt separability probabilities of the 15- and 9-dimensional convex sets of complex and real two
Perturbation analysis and optimization of multiclass multiobjective Stochastic Flow Models

Stochastic Flow Models (SFMs) are stochastic hybrid systems that abstract the dynamics of complex discrete event systems involving the control of sharable resources. SFMs have been used to date to study systems with a single user class or some multiclass settings in which performance metrics are not class-dependent. In this paper, we develop a SFM framework for multiple classes and class-dependent performance objectives in which we can analyze new, occasionally counterintuitive, phenomena and give rise to a new type of “induced” events that capture delays in the SFM dynamics. In the case of two classes, we derive Infinitesimal Perturbation Analysis (IPA) estimators for their derivatives and use them as the basis for on-line optimization algorithms that apply to the underlying discrete event system (not the SFM). This allows us for the first time in the use of SFMs to contrast system-centric and user-centric objectives.
The Menu of Features that Define Primary MicroRNAs and Enable De Novo Design of MicroRNA Genes

MicroRNAs (miRNAs) are small regulatory RNAs processed from stem-loop regions of primary transcripts (pri-miRNAs), with the choice of stem loops for initial processing largely determining what becomes a miRNA. To identify sequence and structural features influencing this choice, we determined cleavage efficiencies of >50,000 variants of three human pri-miRNAs, focusing on the regions intractable to previous high-throughput analyses. Our analyses revealed a mismatched motif in the basal stem region, a preference for maintaining or improving base pairing throughout the remainder of the stem, and a narrow stem-length preference of 35 ± 1 base pairs. Incorporating these features with previously identified features, including three primary-sequence motifs, yielded a unifying model defining mammalian pri-miRNAs in which motifs help orient processing and increase efficiency, with the presence of more motifs compensating for structural defects. This model enables generation of artificial pri-miRNAs, designed de novo, without reference to any natural sequence yet processed more efficiently than natural pri-miRNAs.
Synthesis of substituted hexacyclo[5.4.1.02,6.03,10.05,9.08,11]dodecanes. A novel method for bridging across the 8,11-positions of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione and related diketones

Reaction of pentcylco[5.4.0.02.6.03,10.05.9]undecane-8,11-dione mono(ketene dithioacetal), 2, with hydrogen at 50 psig over palladized charcoal catalyst results in reductive cyclization, thereby affording the corresponding bridged dithioketal, 3. The results of similar reactions with other cage and noncage 1,4-dione systems point to the need for spatial proximity between reacting centers in order to achieve ring formation via this process.
Clinical Effectiveness of Mechanical Ventricular Bypass in Treating Postoperative Heart Failure

Summary: Our group has designed an air-powered, sac-type ventricular assist pump (VAP) that has a smooth polyurethane surface and Bjork-Shiley-type valves. This VAP has undergone extensive testing in calves and has been available for clinical use during the last 5 years. When properly employed, the circulatory support permitted immediate separation of the patient from bypass. Definite hemodynamic evidence of improved ventricular function has been observed during the period of unloading of the deranged ventricle by the VAP. However, during the first 3 years of our experience, the VAP was used in 11 patients with 1 survivor. During the last 2 years, specific attention has been directed to use of right, left, or biventricular assistance as indicated, to prompt application of the VAP when required, and to use of atrial rather than ventricular cannulation for VAP inflow. Accordingly, the survival rate over this 2-year period has increased to 50% (four of eight patients). The short-term assist pump is an important adjuvant for the surgeon who operates on seriously ill cardiac patients.
Co-design of software and hardware to implement remote sensing algorithms

Both for offline searches through large data archives and for onboard computation at the sensor head, there is a growing need for ever-more rapid processing of remote sensing data. For many algorithms of use in remote sensing, the bulk of the processing takes place in an ``inner loop'' with a large number of simple operations. For these algorithms, dramatic speedups can often be obtained with specialized hardware. The difficulty and expense of digital design continues to limit applicability of this approach, but the development of new design tools is making this approach more feasible, and some notable successes have been reported. On the other hand, it is often the case that processing can also be accelerated by adopting a more sophisticated algorithm design. Unfortunately, a more sophisticated algorithm is much harder to implement in hardware, so these approaches are often at odds with each other. With careful planning, however, it is sometimes possible to combine software and hardware design in such a way that each complements the other, and the final implementation achieves speedup that would not have been possible with a hardware-only or a software-only solution. We will in particular discuss the co-design of software and hardware to achieve substantial speedup of algorithms for multispectral image segmentation and for endmember identification.
On the Correlation of Torque and Luminosity in GX 1+4

Over 5 years of daily hard X-ray (>20 keV) monitoring of the 2 minute accretion-powered pulsar GX 1+4 with the Compton Gamma Ray Observatory/BATSE large-area detectors has found nearly continuous rapid spin-down, interrupted by a bright 200 day spin-up episode. During spin-down, the torque becomes more negative as the luminosity increases (assuming that the 20-60 keV pulsed flux traces bolometric luminosity), the opposite of what is predicted by standard accretion torque theory. No changes in the shape of the 20-100 keV pulsed energy spectrum were detected, so that a very drastic change in the spectrum below 20 keV or the pulsed fraction would be required to make the 20-60 keV pulsed flux a poor luminosity tracer. These are the first observations that flatly contradict standard magnetic disk accretion theory, and they may have important implications for understanding the spin evolution of X-ray binaries, cataclysmic variables, and protostars. We briefly discuss the possibility that GX 1+4 may be accreting from a retrograde disk during spin-down, as previously suggested.
Biomarkers of Aging

Abstract This article presents a conceptual discussion of some aspects involved in biomarkers in aging. A biomarker of aging is a biological parameter of an organism that either alone or in some multivariate composite will, in the absence of disease, better predict functional capability at some late age than will chronological age. The reasons for undertaking biomarker research, criteria for putative biomarkers, measurement and assessment of putative biomarkers, and the new initiative by the National Institute on Aging in biomarker research are discussed.
A Machine That Knows Its Own Code

We construct a machine that knows its own code, at the price of not knowing its own factivity.
AN INTERPRETATION OF INDUCED ELECTRIC CURRENTS IN LONG PIPELINES CAUSED BY NATURAL GEOMAGNETIC SOURCES OF THE UPPER ATMOSPHERE

Electric currents in long pipelines can contribute to corrosion effects that limit the pipe's lifetime. One cause of such electric currents is the geomagnetic field variations that have sources in the Earth's upper atmosphere. Knowledge of the general behavior of the sources allows a prediction of the occurrence times, favorable locations for the pipeline effects, and long-term projections of corrosion contributions. The source spectral characteristics, the Earth's conductivity profile, and a corrosion-frequency dependence limit the period range of the natural field changes that affect the pipe. The corrosion contribution by induced currents from geomagnetic sources should be evaluated for pipelines that are located at high and at equatorial latitudes. At midlatitude locations, the times of these natural current maxima should be avoided for the necessary accurate monitoring of the pipe-to-soil potential.
Exact permutation tests for non-nested non-linear regression models

Abstract This paper proposes exact distribution-free permutation tests for the specification of a non-linear regression model against one or more possibly non-nested alternatives. The new tests may be validly applied to a wide class of models, including models with endogenous regressors and lag structures. These tests build on the well-known J test developed by Davidson and MacKinnon [1981. Several tests for model specification in the presence of alternative hypotheses. Econometrica 49, 781–793] and their exactness holds under broader assumptions than those underlying the conventional J test. The J -type test statistics are used with a randomization or Monte Carlo resampling technique which yields an exact and computationally inexpensive inference procedure. A simulation experiment confirms the theoretical results and also shows the performance of the new procedure under violations of the maintained assumptions. The test procedure developed is illustrated by an application to inflation dynamics.
Investment Analysis Under Uncertainty

Investment projects are described in this paper as a pattern of uncertain cash flows over time; i.e., as a cash flow pattern over an event tree. Whereas the portfolio problem of selecting projects generally requires simultaneous consideration of all available projects, here we seek sufficient conditions for accepting and rejecting individual projects. These conditions are formulated as mathematical programming problems which are amenable to routine application at subordinate levels of an organization. “Investment is, in essence, present sacrifice for future benefit. But the present is relatively well known, whereas the future is always an enigma. Investment is also, therefore, certain sacrifice for uncertain benefit.”1
Digital Correlation Microwave Polarimetry: Analysis and Demonstration

The design, analysis, and demonstration of a digital-correlation microwave polarimeter for use in Earth remote sensing is presented. The authors begin with an analysis of a three-level digital correlator and develop the correlator transfer function and radiometric sensitivity. A fifth-order polynomial regression is derived for inverting the digital correlation coefficient into the analog statistic. In addition, the effects of quantizer threshold asymmetry and hysteresis are discussed. A two-look unpolarized calibration scheme is developed for identifying correlation offsets. The developed theory and calibration method are verified using a 10.7 GHz and a 37.0 GHz polarimeter. The polarimeters are based upon 1-GS/s three-level digital correlators and measure the first three Stokes parameters. Through experiment, the radiometric sensitivity is shown to approach the theoretical as derived earlier in the paper and the two-look unpolarized calibration method is successfully compared with results using a polarimetric scheme. Finally, sample data from an aircraft experiment demonstrates that the polarimeter is highly useful for ocean wind-vector measurement.
Follow-up after acute asthma episodes: What improves future outcomes?

Emergency departments (EDs) are commonly used for the acute and chronic management needs of patients with asthma in the United States and account for nearly 2 million visits each year. Traditionally, the role of emergency physicians in caring for patients with acute asthma has been to provide emergency treatment and then to suggest follow-up visits with the primary care provider for ongoing preventive care. However, rates of follow-up with primary care providers are often low. Effective and timely outpatient care of asthma can prevent adverse asthma outcomes, specifically ED visits and hospitalizations. For example, Ford et al assessed the effect of an asthma education program on African American and white adults with asthma and found patients who received an asthma education intervention demonstrated a decrease in ED visits after the education intervention versus patients who did not receive the educational intervention, with the most significant period of improvement observed in the first 4 months of receiving the educational intervention program. A case-control study on children ages 0 to 14 years was conducted to identify outpatient management practices associated with increased or decreased risk of adverse outcomes. It was noted that patients with written asthma management plans were half as likely to have a hospitalization or an ED visit as those who lacked a plan.
Radiative-convective instability

[1] Radiative-moist-convective equilibrium (RCE) is a simple paradigm for the statistical equilibrium the earth's climate would exhibit in the absence of lateral energy transport. It has generally been assumed that for a given solar forcing and long-lived greenhouse gas concentration, such a state would be unique, but recent work suggests that more than one stable equilibrium may be possible. Here we show that above a critical specified sea surface temperature, the ordinary RCE state becomes linearly unstable to large-scale overturning circulations. The instability migrates the RCE state toward one of the two stable equilibria first found by Raymond and Zeng (2000). It occurs when the clear-sky infrared opacity of the lower troposphere becomes so large, owing to high water vapor concentration, that variations of the radiative cooling of the lower troposphere are governed principally by variations in upper tropospheric water vapor. We show that the instability represents a subcritical bifurcation of the ordinary RCE state, leading to either a dry state with large-scale descent, or to a moist state with mean ascent; these states may be accessed by finite amplitude perturbations to ordinary RCE in the subcritical state, or spontaneously in the supercritical state. As first suggested by Raymond (2000) and Sobel et al. (2007), the latter corresponds to the phenomenon of self-aggregation of moist convection, taking the form of cloud clusters or tropical cyclones. We argue that the nonrobustness of self-aggregation in cloud system resolving models may be an artifact of running such models close to the critical temperature for instability.
Plasma-filled radial acceletron

Recent experimental studies have shown that the presence of plasma in the high-power microwave sources using intense charged beams, when properly introduced, may enhance the efficiency of the source. These findings have been confirmed by numerical simulations for some high-power microwave sources. The enhancement has been partly attributed to the neutralizing effect of the positively charged plasma on lowering the disruptive space charge effects of the electron beam used to generate the RF, and partly to a modification of the dispersion relation leading to higher group velocities for the traveling radio frequency (RF) waves. Mode selection may also be favorably affected by the presence of plasma in the source. We present the results of numerical simulations carried out to study the effect of plasma on an acceletron device. Both neutral as well as positively charged plasmas have been explored. The acceletron device is run in transverse magnetic TM/sub 001/ mode and generates a 3.2-GHz steady oscillation without any competing modes. The effect of the plasma at several different densities has been explored. Our results indicate a significant enhancement of the acceletron operation due to the plasma. Other plasma densities are being studied. The PIC code used in our simulations was the MRC 2 1/2-dimensional code MAGIC.
Duals for SU(N) SUSY Gauge Theories with an Antisymmetric Tensor: Five Easy Flavors

I consider N = 1 supersymmetric SU(Nc) gauge theories with matter fields consisting of one antisymmetric representation, five flavors, and enough antifundamental representations to cancel the gauge anomaly. Previous analyses are extended to the case of even Nc with no superpotential. Using holomorphy I show that the theory has an interacting infrared fixed point for sufficiently large Nc. These theories are interesting due to the fact that in going from five to four flavors the theory goes from a non-trivial infrared fixed point to confinement, in contradistinction to SUSY QCD, but in analogy to the behavior expected in non-SUSY QCD.
Construction of Vicinal Tertiary and All-Carbon Quaternary Stereocenters via Ir-Catalyzed Regio-, Diastereo-, and Enantioselective Allylic Alkylation and Applications in Sequential Pd Catalysis

Highly congested vicinal stereocenters comprised of tertiary and all-carbon quaternary centers were generated via Ir-catalyzed asymmetric allylic alkylation of β-ketoesters. These catalytic reactions proceed in excellent yields with a broad scope on either reaction partner and with outstanding regio-, diastereo-, and enantiocontrol. Implementation of a subsequent Pd-catalyzed alkylation affords dialkylated products with pinpoint stereochemical control of both chiral centers.
Electrophile-induced ether transfer: stereoselective synthesis of 2,4,6-trisubstituted tetrahydropyrans.

Stereoselective synthesis of trans-2,6-disubstituted-3,4-dihydropyrans has been achieved from a simple homoallylic alkoxyether via a three-step sequence: electrophile-induced ether transfer, cyclization, and functionalization, which is highlighted by a rare example of Ferrier rearrangement of allylic ether. This methodology was successfully implemented for the asymmetric synthesis of a C7−C17 fragment of swinholide A.
Taxol: The chemistry and structure-activity relationships of a novel anticancer agent

Taxol is an exciting new anticancer drug, showing clinical activity against ovarian and breast cancer. Its development as a clinically useful drug has involved major efforts to overcome the supply problem; this has now been done, and the focus of interest has moved to the development of improved analogs of the drug. Recent notable achievements include the first total synthesis of taxol, and the first indications of its binding site on tubulin.