cssi/SciSciGPT-SciSciNet huggingface dataset:
Neutron reflectivity study of the density profile of a model end-grafted polymer brush: Influence of solvent quality

Neutron reflectivity measurements are made on a chemically end-grafted polymer brush swollen over a range of temperatures above and below the theta point. Good agreement between the brush profiles and recent self-consistent field calculations and numerical simulations is obtained for temperatures in the vicinity of the theta point and in a good solvent. The expansion of the main body of the brush resembles a swelling gel, while the brush tail expands similarly to a polymer in solution.
A White Shrimp Mark-Recapture Study

Abstract Marked sub-adult white shrimp were released in Galveston Bay in August 1963. Recoveries indicated there was no emigration from the bay between August and mid-October. Using the Bertalanffy growth function estimates of L∞ equals 214 mm, K = 0.09 (sexes combined). Shrimp increased rapidly in size, 98 to 133 mm in 4 wk and to 146 mm in 6 wk during the warm summer months. Reliable estimates of natural and fishing mortality could not be obtained. Several techniques were used to obtain estimates but they varied to such a degree that results were questionable. Probable causes of these inaccurate estimates are nonrandom distribution of the marked population, fishing effort, or a combination of both.
Capital flows and current account dynamics in Turkey: A nonlinear time series analysis☆

Abstract The paper offers an analysis of current account dynamics and its sustainability in Turkey using quarterly data. The focus is on the nonlinear characterization of the long run intertemporal budget constraint and the stationarity tests. Several well-known tests are applied to identify nonlinearity in the current account time series. The analysis reveals that while the classical unit root tests based on linear specification give rise to conflicting results as to the nonstationarity of the current account deficit series, a threshold unit root test due to Caner and Hansen (2001) fails to reject the null of nonstationarity, implying that the intertemporal budget constraint would not be satisfied in the long run.
Digestion in steers and lactational performance of Jersey cows fed diets varying in natural protein level continuously or on alternate days

Five crossbred beef steers (515 kg) were used in a Latin square experiment and 36 lactating Jersey cows (12 primiparous, 310 kg; 24 multiparous, 365 kg) were used in a completely randomized design study to determine effects on characteristics of digestion and lactational performance of daily alternation of the dietary level of natural protein (NP). In Experiment 1, steers were fed diets of 50% bermudagrass hay and 50% concentrate. Concentrate was approximately 18% crude protein (CP), formulated to be 60, 80 or 100% NP (varying proportions of soybean meal, urea and ground corn), and was fed at 1.5% body weight (dry matter basis). These concentrates were fed daily or ones with 60 and 100% NP were fed on alternate days. Alternate day feeding did not markedly affect characteristics of digestion, including ruminal escape of feed protein, and NP level of concentrate fed continuously had no effects either. In Experiment 2, cows were subjected to treatments similar to those in Experiment 1, and performance on d 20-40 of lactation was measured. Concentrate was given at 1 kg (as fed)/2.15 kg milk produced, yielding a dietary concentrate level of approximately 40% (dry matter basis). Alternate feeding depressed (P less than 0.05) overall milk fat percentage. Alternate feeding increased production of milk and protein and body weight of primiparous cows but caused little change with multiparous cows. Besides increasing the dietary level of concentrate, perhaps alternate feeding regimes have utility to lower milk fat level without impairing milk production. Level of NP in concentrate fed continuously did not affect performance by multiparous cows though primiparous cow performance was generally enhanced, possibly because CP intake was adequate for multiparous cows but marginal for primiparous cows. However, overall, efficiency of production of solids-corrected milk rose slightly with increasing NP.
Crystal rotation by mechanical interaction between plastically anisotropic crystals

Abstract In polycrystalline material, minerals with pronounced plastic anisotropy may experience inhomogeneous deformation and significant mechanical interaction between neighboring crystals. To study the effect of crystal interaction on preferred orientation, pure shear of a polycrystalline material with identical, orthogonal slip systems was modeled two-dimensionally by the finite-element method. Such a material is non-ductile in the formal von Mises sense because it lacks five independent slip systems. As a result, each crystal has highly anisotropic strength. Because a homogeneous, irrotational strain history in a two-dimensional crystal with identical, orthogonal slip systems does not cause lattice rotation, rotation caused by crystal interaction is readily observed. In the finite-element models, slip planes rotate toward a preferred orientation parallel to maximum shear stress (45° to shortening and extension directions). Mechanical interaction between neighboring crystals produces this preferred orientation by rigid-body rotation of crystals or parts of crystals not favorably oriented for slip.
A comparative study of sialic acid-rich proteins in rat bone and dentin.

Four sialic acid-rich (SA-rich) proteins found in bone and dentin, osteopontin (OPN), bone sialoprotein (BSP), bone acidic glycoprotein-75 (BAG-75), and dentin matrix protein 1 (DMP1), share some common features. We used SDS-PAGE and Western immunoblots to analyze and compare SA-rich proteins in bone and dentin extracts from rats with a single chromatographic procedure. OPN was detected in dentin extracts, with a relative level less than one-seventieth of that in bone. Both bone and dentin BSP demonstrated an extremely broad distribution pattern, probably due to a high degree of heterogeneity in post-translational modifications. BAG-75 in both bone and dentin was detected as an 83 kDa band, dramatically distinct from that of DMP1. Using a polyclonal antibody raised against a purified bone 57 kDa protein (a portion of DMP1), we detected 150 kDa protein bands in bone fraction; the same bands were recognized by anti-recombinant rat DMP1 antibody. Bands from dentin migrating at about 150 kDa in earlier fractions and progressing to 200 kDa in later fractions showed a clear immunoreactivity to the anti-57 kDa antibody. We conclude that the majority of DMP1 in rat bone is processed into fragments, whereas that in dentin remains intact.
Current political dynamics in Asia: Issues, developments and threats

The author examines the current political dynamics in Asia and the potential threat situations jeopardizing the regional security. The article looks at proliferation of nuclear weapons and the North Korean and the Iranian nuclear cases. It studies the international pressures, diplomacy moves and the Iranian reaction and the EU and American perceptions. The Taiwan issue and territorial dispute of the South China Sea and the problem of Kashmir between Pakistan and India are discussed. The regional radical terrorism networks under the Islamic guise are also examined.
Stress/strain/time relations for ice under uniaxial compression

Abstract Results of mechanical tests involving uniaxial compression of isotropic ice at −5°C were analysed and interpreted. Constant load (CL) creep tests were made for applied stresses in the range 0.8 to 3.8 MPa, and “strength” tests under constant displacement rate (CD) were made for applied strain rates in the range 10 −7 to 10 −3 s −1 . Results from CL tests and CD tests corresponded closely, giving much the same information about failure strains, strength, creep rates, time to failure, stress/strain-rate relations, and suchlike. Empirical stress/strain-rate relations were developed for three distinct states of strain: (1) for the initial yield point, where axial strains are typically of the order of 0.1%, (2) for the ductile yield point, where axial strains are typically of the order of 1%, (3) for an axial strain of 10%. Stress/strain-rate relations and stress/strain relations for constant duration of CL loading were examined for load durations up to half an hour. The elapsed time up to the ductile yield point (∼1% strain) was related to stress and to strain rate for CL tests and CD tests, and correspondence of the results was demonstrated both for interrelationship between CL and CD tests and for compatibility with the appropriate stress/strain-rate relations. The elapsed time up to the initial yield point was also considered. It was shown that CD stress/strain curves can be constructed from a suitable family of CL creep curves, and vice versa. The characteristics of CL creep curves and CD stress/strain curves were examined in some detail, considering relations between strain rates for certain identifiable points on creep curves, and relations between stresses for certain identifiable parts of stress/strain curves. Effective values for quasi-elastic moduli were considered. The strains for various critical points were compared with each other and with the strains at which rates of acoustic emissions reach maximum values.
Health-related quality of life measurement in adult systemic lupus erythematosus: Lupus Quality of Life (LupusQoL), Systemic Lupus Erythematosus-Specific Quality of Life Questionnaire (SLEQOL), and Systemic Lupus Erythematosus Quality of Life Questionnaire (L-QoL).

Throughout the course of their disease, individuals with systemic lupus erythematosus (SLE) face considerable physical, psychological and social challenges. The disease has profound effects on health-related quality-of-life (HRQoL), which have been documented extensively in the literature (1). Capturing decrements and improvements in HRQoL has therefore become important in clinical research in SLE, and is advocated by both the U.S. Food and Drug Administration (FDA) in providing guidance to SLE clinical trialists as well as the Outcome Measures in Rheumatology Clinical Trials (OMERACT) group (2, 3). Here I review three measures designed to ascertain HRQoL in SLE, the Lupus Quality of Life (LupusQoL), SLE-specific Quality of Life questionnaire (SLEQoL) and SLE Quality of Life Questionnaire (L-QoL) (Table 1). These measures were chosen because they were developed and specifically designed as patient-reported outcome measures to assess quality of life in SLE and have all had some published validation testing to date. Table 1 Characteristics of disease-specific health-related quality-of-life measures in adult systemic lupus erythematosus.
FEDERAL TAXATION OF LIFE INSURANCE COMPANIES: THE SAVINGS INSTITUTION APPROACH*

s of Doctoral Dissertations 425 protection-selling businesses and institutions of deposit, (2) difficulties involved in determining underwriting gains and losses on a year-to-year basis, and (3) competitive issues arising from the mutual-stock division within the industry. This paper rejects the traditional approaches as useful measures for resolving these issues. This rejection has led to the formulation of the "savings institution" approach-centralized about the theory that the proper method of taxation must proceed from the savings-institution characteristics of life insurance companies. Basically, this system permits the underwriting function to be exercised without tax consequence, contending that tax laws should not penalize this unique and socially desirable contribution of insurance. However, to the extent that insurance companies operate as savings institutions, taxes would be imposed in a manner substantially similar to other savings institutions,-notably mutual savings banks and savings and loan associations. Moreover, the individual who elects to save in one-rather than in another-of these institutions would also be accorded equal tax treatment. Following guideposts established for taxing savings banks and savings associations, life insurance companies would (1) report to policyholders the interest element in the annual increment in the cash value of policies (this interest would be taxable income to policyholders); (2) be permitted to create a tax-free contingency reserve equal to 10 per cent of statutory policy reserves; (3) pay taxes at corporate rates on profits retained in excess of this reserve. Formally, stock and mutual insurers would be taxed alike; effectively, stock insurers would be taxed more severely. Reporting would conform essentially to the industry-wide uniform accounting system established by the state insurance departments. Consequently, all income-premiums, investment income, and net capital gainswould be included in the tax base, and all operating expenses, reserve interest requirements, and policyholder dividends would be deducted before deriving net operating gain. Several minor modifications are also proposed based upon considerations of equity and administrative simplicity. This content downloaded from 40.77.167.21 on Wed, 05 Jul 2017 18:04:18 UTC All use subject to http://about.jstor.org/terms
Using Molecular Modeling To Understand Some of the More Subtle Aspects of Aromaticity and Antiaromaticity

π-Electron delocalization exerts one of the most significant structure or energy influences in organic chemistry. Apart from determining the shapes of alkenes and alkynes, the planarity of aromatic molecules is a hallmark of π-electron delocalization. Huckel’s rules for aromaticity are easily applied in the teaching of undergraduates, but occasionally, some interesting discussions arise when questions are asked about some potentially aromatic nonbenzenoid molecules and antiaromaticity. Molecular modeling, using the X-ray crystallographic coordinate data for a representative sample of these interesting molecules, will lead to a greater understanding of just how these π-systems achieve stability.
Lower bounds on entropy via the Conley index with application to time series

Abstract A proof of a localized version of the proven entropy conjecture for C ∞ smooth maps is given. This allows for computational methods for bounding topological entropy through properties of the Conley index. Chaos can then be determined by a non-global index calculation robust under possibly large (and noisy) perturbations. In addition, a proof of a Wazewski's Principle for time series analysis is given which allows for lifting of entropy to the observed dynamical system under certain conditions.
Cyclospora: an overview.

Popularization of the acid-fast stain in the early 1980s for detecting Cryptosporidium species in stool specimens set the stage for recognition of Cyclospora species. Between 1986 and 1993, there were nine reports linking diarrheal illness in more than 200 immunocompetent and immunocompromised children and adults to an unidentified, acid-fast organism resembling a "large Cryptosporidium" [2-10]. On the basis of electron microscopic studies in 1990 that revealed photosynthesizing organelles within the organism, similar to those of blue-green algae, Long et al. suggested that it was a cyanobacterium similar to Chlorella species [7]. Thus, in addition to being called a large Cryptosporidium, the organism has been called a coccidian-like body or a cyanobacterium-like body (CLB), a bluegreen alga, a Cryptosporidium muris-like cyst, a fungal spore, and a species of Blastocystis. In 1993, Ortega et al. [11] succeeded in inducing Cyclospora to sporulate and showed that, when mature, it has two sporocysts, each containing two sporozoites. Thus, the organism is the oocyst stage of the coccidian parasite Cyclospora [11]. Detailed electron microscopic studies, which revealed that the Cyclospora sporozoites possess a membrane-bound nucleus and micronemes that are characteristic of the phylum Apicomplexa, provided additional evidence that the organism is a coccidian [11]. With use of molecular phylogenetic analysis, Relman [12] recently confirmed that Cyclospora is a coccidian related to Eimeria species and possibly most closely related to Isospora species [12]. It is of interest that the first report of human cyclospora infection (which had largely gone unnoticed until 1993) came from Papua New Guinea in 1979, before the popularization of acid-fast stained stool smears and the advent of molecular phylogenetic analysis [2, 13]. In that report, Ashford [2] detailed the morphological characteristics of a coccidian-like or-
Explosive consolidation of (Bi, Pb)-Sr-Ca-Cu-O superconductor powders

Superconducting (2212 phase) Bi-Sr-Ca-Cu-0 (BSCCO) and BSCCO-Ag composites were explosively consolidated in silver tubing and then drawn and rolled into tapes. These silver-sheathed tapes were then subjected to repeated cycles of pressing and heat treatment, which resulted in enhanced texturing and grain growth and a subsequent increase in critical current density (Jc). The effect of Ag powder additions to the superconducting powder further increased texturing and Jc, with optimal properties occurring with 10 vol.% silver powder additions. Scanning electron microscopy indicated that grain alignment increased and grain structure became refined after the thermomechanical treatment. X-ray diffraction studies indicated that grain orientation and conversion of 2212 phase to 2223 phase are improved when explosive consolidation is introduced before the drawing step in the powder-in-tube process.
The Fast Collisionless Reconnection Condition and the Self-Organization of Solar Coronal Heating

I propose that solar coronal heating is a self-regulating process that keeps the coronal plasma roughly marginally collisionless. The proposed self-regulating mechanism is based on the interplay of two effects. First, plasma density controls coronal energy release via the transition between the slow collisional Sweet-Parker regime and the fast collisionless reconnection regime. This transition takes place when the Sweet-Parker layer becomes thinner than the characteristic collisionless reconnection scale. I present a simple criterion for this transition in terms of the upstream plasma density (ne), the reconnecting (B0) and guide (Bz) magnetic field components, and the global length (L) of the reconnection layer: L ≲ 6 × 109 cm (ne/1010 cm-3)-3(B0/30G)4(B0/Bz)2. Next, coronal energy release by reconnection raises the ambient plasma density via chromospheric evaporation, and this in turn temporarily inhibits subsequent reconnection involving the newly reconnected loops. Over time, however, radiative cooling gradually lowers the density again below the critical value and fast reconnection again becomes possible. As a result, the density is highly inhomogeneous and intermittent but, statistically, does not deviate strongly from the critical value, which is comparable with the observed coronal density. Thus, in the long run the coronal heating process can be represented by repeating cyclesmore » that consist of fast reconnection events (i.e., nanoflares), followed by rapid evaporation episodes, followed by relatively long periods ( 1 hr) during which magnetic stresses build up and the plasma simultaneously cools down and precipitates.« less
Methacycline Compared with Ampicillin in Acute Bacterial Exacerbations of Chronic Bronchitis: A Double-Blind Crossover Study

In order to objectively document the accepted clinical efficacy of ampicillin in treating bacterial exacerbations of chronic bronchitis, as well as to evaluate the efficacy of methacycline, a double-blind crossover study was designed. Twenty patients with chronic bronchial disease were treated for two separate acute bacterial exacerbations, once with 2 gm of ampicillin daily, and once with 600 mg of methacycline daily, for 14 days. There were a few significant differences when comparing the efficacy of the antimicrobials. For example, the daily volume of sputum significantly went from 35.6 ml initially to 20.5 ml at the end of treatment with methacycline, and from 37.4 to 18.0 ml with ampicillin. Sputum neutrophils excreted per day went from 446 to 147 million with methacycline and from 433 to 94 million with ampicillin. Gram-positive diplococci and cocci on gram stains of sputum significantly decreased from 10.6 to 3.3 with methacycline and from 16.8 to 2.1 with ampicillin. This investigation objectively documents the accepted clinical efficacy of ampicillin and proves methacycline to be an equally effective agent.
End-Group Effects on the Structure and Spectroscopy of Oligoazines

Oligoazines with three different types of end groups, ketone, hydrazone, and 2-pyridine, are studied in solution. When the end groups are ketone or 2-pyridine, the 1H and 13C NMR spectra are simple and show that the oligomers maintain 2-fold symmetry up to the longest chain lengths investigated (five azine units for the 2-pyridine end groups). In contrast, when the end groups are hydrazones, the 1H NMR spectra show evidence for as many as five conformers present in solution for each oligomer while the 13C NMR spectra are still simple, indicative of a single compound. Semiempirical AM1 calculations suggest that all of the oligoazines should be severely twisted but give no insight about the origin of the large number of conformers found for the materials with hydrazone end groups. The end groups have a significant effect on the UV spectra. All the oligoazines show two absorptions close in energy, but the relative intensities change depending upon the end group. For ketone end groups the higher energy transi...
Innate Immunology of Bovine Respiratory Disease

There are a variety of factors and conditions that predispose cattle to pneumonia. Cattle have anatomic and cellular differences from humans and other species and are managed in groups/herds, all of which can increase susceptibility to microbial pathogens. This article highlights the basic innate immune response of the respiratory tract and newer developments in the understanding of adaptive immune responses of the bovine respiratory tract, placing special emphasis on features unique to cattle.
Intragenic complementation and oligomerization of the L subunit of the Sendai virus RNA polymerase

Abstract The RNA-dependent RNA polymerase of Sendai virus consists of two subunits, the L and P proteins, where L is thought to be responsible for all the catalytic activities necessary for viral RNA synthesis. Sequence alignment of the L proteins of a variety of negative-stranded RNA viruses revealed six regions of good conservation, designated domains I–VI, which are thought to correspond to functional domains of the protein. Analysis of a number of site-directed mutants within the six domains of L allowed us to conclude that the activities of the polymerase are not simply compartmentalized and that each domain contributes to multiple steps in viral RNA synthesis. Nevertheless these domains can function in trans since we demonstrate here that intragenic complementation between pairs of coexpressed inactive L mutants can restore viral RNA synthesis on an added template. Although intragenic complementation is typically very inefficient, complementation to restore leader RNA synthesis was surprisingly very efficient for some pairs and complementation of mRNA synthesis and genome replication was less, but still significant. Complementation occurred with L mutants in five of the six domains, the exception being a domain III mutant, and required the cotranslation of the two L mutants. C-terminal truncations deleting up to half of L were capable of restoring transcription of an inactive domain I L mutant at amino acid 379. Oligomerization of L in the polymerase complex was demonstrated directly by the co-immunoprecipitation of differentially epitope-tagged full-length and truncated L proteins. These data are consistent with L protein being an oligomer with multiple independent domains each of which exhibits several functions.
Adenomatous polyposis coli plays a key role, in vivo, in coordinating assembly of the neuronal nicotinic postsynaptic complex

The neuronal nicotinic synapse plays a central role in normal cognitive and autonomic function. Molecular mechanisms that direct the assembly of this synapse remain poorly defined, however. We show here that adenomatous polyposis coli (APC) organizes a multi-molecular complex that is essential for targeting alpha3(*)nAChRs to synapses. APC interaction with microtubule plus-end binding protein EB1 is required for alpha3(*)nAChR surface membrane insertion and stabilization. APC brings together EB1, the key cytoskeletal regulators macrophin and IQGAP1, and 14-3-3 adapter protein at nicotinic synapses. 14-3-3, in turn, links the alpha3-subunit to APC. This multi-molecular APC complex stabilizes the local microtubule and F-actin cytoskeleton and links postsynaptic components to the cytoskeleton--essential functions for controlling the molecular composition and stability of synapses. This work identifies macrophin, IQGAP1 and 14-3-3 as novel nicotinic synapse components and defines a new role for APC as an in vivo coordinator of nicotinic postsynaptic assembly in vertebrate neurons.
On the history and progress of sampled-data systems

Historical highlights and a progress review of sampled-data systems are presented herein. Recent emergence of digital signal processing and digital filters as an aftermath of sampled-data systems is brought into focus as well as the technological developments that aided in this new emergence. Recent advances made in multidimensional discrete theory and its applications are also discussed. The paper concludes with a critical view of the past achievements in this field as well as indications of possible future developments.
Toward a unified theory of disease: Understanding the aging process

Abstract Medicine is complex and multi-disciplined with each speciality trying to cure specific illness in their fields of interest. Research would be more productive if there was a common denominator applicable to all medical specialities — i.e., a unified theory of disease. Of the seventy-two leading causes of death in the United States in 1980, there was a direct relationship with age, after age four, for virtually all causes of death per 100, 000 population. Understanding the genetics of the aging process and developing capacities to manipulate such factors could revolutionize medicine by giving it a working unified theory applicable to all its disciplines.
Quantum optics of two-level atoms in a dielectric: comparison of macroscopic and microscopic quantizations of the dielectric

Abstract We obtain Langevin–Bloch equations of motion for optically resonant atoms embedded in a dielectric host using both the conventional macroscopic quantization of the field in a dielectric and the microscopic quantization of the Lorentz model of enumerated oscillators embedded in the vacuum. The two sets of equations of motion exhibit substantial differences in their dependence on the index of refraction of the host dielectric medium. We compare and contrast the essential conceptual features of the macroscopic and microscopic theories, relating the inconsistency of the results to differences in the underlying Maxwellian and Lorentzian descriptions of the interaction of the radiation with the vacuum and matter. We invoke the correspondence principle to discriminate between the two results and demonstrate that quantization of the macroscopic Maxwell equations leads to incorrect equations of motion for embedded two-level atoms while the microscopic result is consistent with the correspondence principle.
El Salvador:: A Bibliography on Its History and Current Civil War

Agee, Philip. White Paper Whitewash: Interviews with Philip Agee on the CIA and El Salvador. Edited by Werner Poelchau. New York: Deep Cover Books (Box 677, New York 10013), 1981. $8.00. Written by a former CIA agent, author of Inside the Company. Critique of Communist Interference in El Salvador, cited below.
The Impact of Farmland Price Changes on Farm Size and Financial Structure

A modified Vickers model is used to show that farmland capital gains provide incentive to increase farm acreage and debt use. Farmland capital losses have the opposite effect. The model indicates that part of the current financial vulnerability of the U.S. farm sector can be traced to management decisions made in response to the farmland capital gains of the 1970s. The effects are not purely tax driven, though taxes can affect the magnitude of incentives. The Vickers model is modified to allow a finite horizon, taxes, and the recognition of unrealized capital gain or loss.
Trauma in Pregnancy

The treatment of pregnant patients with traumatic injuries requires knowledge of the fundamentals of general trauma management as well as the specific anatomic and physiologic changes brought about by pregnancy. This article provides a review of the spectrum of trauma prevention and treatment in pregnant women, from counseling strategies that can be used during any emergency department visit to a step-by-step evaluation protocol for patients with trauma during pregnancy and the severe injuries that might be encountered by providers during the treatment of these women, including maternal cardiopulmonary arrest and the perimortem cesarean section. Language: en
Self-Organizing Liquid Crystal Perylene Diimide Thin Films: Spectroscopy, Crystallinity, and Molecular Orientation

Three different liquid crystal (LC) perylene diimides were investigated with respect to the optical and physical characteristics of their thin films. Films were prepared by spin-coating, vacuum evaporation, and Langmuir−Blodgett (LB) techniques on substrates such as microscope glass, indium−tin oxide-coated glass and highly oriented pyrolytic graphite. Films were characterized by polarized optical microscopy, absorption and fluorescence emission spectroscopy, and X-ray diffraction. The self-organizing ability of the LC perylene diimides allows them to rapidly reach a stable, low-energy configuration, unlike many thin film materials, and reveals that they are driven to organize and orient in a highly specific fashion, independent of substrate or deposition method. The molecules tend to form a slipped stack arrangement that maximizes attractive π−π electronic interactions, with the π−π stacking axis oriented parallel to the substrate. Relative to the substrate plane, the LC 1 perylene cores are tilted ∼47° ...
Sensor validation and process fault diagnosis for FCC units under MPC feedback

Abstract Model predictive control (MPC) has been widely applied in industry, especially in the refining industry. As all feedback controllers require correct sensor measurements, unreliable sensors can cause the MPC controller to move the process in an erroneous manner. Data validation of sensor measurements is a prerequisite in applying advanced control, particularly multivariable control which depends on many sensors. However, little research work is available on how feedback controllers like MPC complicate the task of sensor validation and process fault diagnosis. In theory, a controller can transfer the effect of a sensor fault in a controlled variable to the manipulated variables. In this paper, principal component analysis (PCA) is applied to detect, identify and reconstruct faulty sensors in a simulated FCC unit. A base PCA model is generated by perturbing the process throughout the operating region. Performance of MPC with and without data validation is compared. The same base PCA model is applied to detect and identify dynamic process faults. We demonstrate that process faults can be detected and diagnosed at an early stage.
The optimization of single mode basis functions for polyatomic vibrational problems with application to the water molecule

We consider the optimization of the wave functions for coupled vibrations represented by linear combinations of products of functions depending only on a single vibrational coordinate. The functions themselves are optimized as well as the configuration list. For the H2O molecule, highly accurate results are obtained for the lowest 15 levels using significantly shorter expansions than would otherwise be possible.
REGIONAL COMPETITIVE ADVANTAGE AND GROWTH IN NATIONAL INTERINDUSTRY MARKETS

A region's producing sectors compete in national markets with other regions, and its output growth therefore depends on changes in the region's sectoral input costs relative to those in other regions. In this model, production costs are taken as dependent upon wages and other payments to local factors and upon costs of interindustry inputs, the producers of which pay wages and other factor costs locally or, if the inputs are imported, in other regions. After consideration of conditions by which regional commodity supply functions can be aggregated, sectoral commodity prices and the regional production of national and local goods are endogenously determined in a computable equilibrium system within a balanced regional model framework.
Racial differences in gait velocity in an urban elderly cohort.

Objectives: To investigate whether there are racial differences in gait velocity in elderly adults. Design: Cross-sectional analysis. Setting: Bronx, New York. Participants: Two hundred thirteen participants of the Einstein Aging Study (157 Caucasian, 56 African American), a longitudinal study of community-residing elderly adults recruited using Medicare and voter registration records. Measurements: Demographic characteristics, medical history, Geriatric Depression Scale, Blessed Information�Memory�Concentration Test, Total Pain Index, gait velocity. Results: Caucasians were older (median 79.9 vs 75.5, P = .002) and more educated (median 14 vs 12 years, P = .007) and had lower body mass index (mean 26.9 ± 4.3 vs 28.9 ± 6.4, P = .03). African Americans were more likely to be female (80.4% vs 59.9%, P = .006) and to have diabetes mellitus (28.6% vs 13.4%, P = .01). Pain levels were not significantly different between Caucasians and African Americans. African Americans had a significantly slower gait velocity (mean 90.2 ± 17.9 vs 99.1 ± 20.1 cm/s, P = .004). This difference persisted after adjusting for multiple covariates. Differences in common factors known to influence gait did not explain a 7.79-cm/s slower gait speed in African Americans than Caucasians. Conclusion: Differences in gait velocity persist between African Americans and Caucasians despite adjusting for many confounders. Increases of just 10 cm/s are associated with lower mortality. Further studies are needed to evaluate whether there are modifiable risk factors that may explain this difference and whether an intervention could reduce the discrepancy between the groups.
Multiple optimal solutions in linear programming models: Comment

Paris recently authored a Journal note dealing with linear-programming multiple-alternative optimal solutions, validation, and programming-econometric interrelationships. We agree with Paris' fundamental theme that linear program multiple solutions requires more attention. However, there are several items which we believe merit comment. Specifically, we discuss Paris' presentations of multiple optimal solutions, validation, and identification. We also briefly comment on some generalizations drawn by Paris.
Defining Molecular and Domain Boundaries in the Bacteriophage ϕ29 DNA Packaging Motor

Summary Cryo-electron microscopy (cryo-EM) studies of the bacteriophage ϕ29 DNA packaging motor have delineated the relative positions and molecular boundaries of the 12-fold symmetric head-tail connector, the 5-fold symmetric prohead RNA (pRNA), the ATPase that provides the energy for packaging, and the procapsid. Reconstructions, assuming 5-fold symmetry, were determined for proheads with 174-base, 120-base, and 71-base pRNA; proheads lacking pRNA; proheads with ATPase bound; and proheads in which the packaging motor was missing the connector. These structures are consistent with pRNA and ATPase forming a pentameric motor component around the unique vertex of proheads. They suggest an assembly pathway for the packaging motor and a mechanism for DNA translocation into empty proheads.
Stock market rationality and price volatility: Tests using Japanese data

Abstract This paper tests the stock market rationality hypothesis, which implies that a stock price is determined as the discounted sum of optimally forecasted future dividends. Mankiw-Romer-Shapiro volatility tests and new volatility tests which do not use the unobservable “ex post rational price” are applied to the data from a stock market in Japan. A Hausman type specification test of the market rationality hypothesis is also developed and applied to the data. The results suggest that we cannot reject the hypothesis that the Japanese stock market is rational. A couple of variance inequalities are violated by the data but the violation does not seem to be significant. J. Japan. Int. Econ. , December 1987, 1 (4), pp. 441–462. Massachusetts Institute of Technology, Cambridge, MA 02139.
A functional polymorphism in renalase (Glu37Asp) is associated with cardiac hypertrophy, dysfunction, and ischemia: data from the heart and soul study.

Author(s): Farzaneh-Far, Ramin; Desir, Gary V; Na, Beeya; Schiller, Nelson B; Whooley, Mary A | Abstract: BackgroundRenalase is a soluble enzyme that metabolizes circulating catecholamines. A common missense polymorphism in the flavin-adenine dinucleotide-binding domain of human renalase (Glu37Asp) has recently been described. The association of this polymorphism with cardiac structure, function, and ischemia has not previously been reported.MethodsWe genotyped the rs2296545 single-nucleotide polymorphism (Glu37Asp) in 590 Caucasian individuals and performed resting and stress echocardiography. Logistic regression was used to examine the associations of the Glu37Asp polymorphism (C allele) with cardiac hypertrophy (LV massg100 g/m2), systolic dysfunction (LVEFl50%), diastolic dysfunction, poor treadmill exercise capacity (METSl5) and inducible ischemia.ResultsCompared with the 406 participants who had GG or CG genotypes, the 184 participants with the CC genotype had increased odds of left ventricular hypertrophy (OR = 1.43; 95% CI 0.99-2.06), systolic dysfunction (OR = 1.72; 95% CI 1.01-2.94), diastolic dysfunction (OR = 1.75; 95% CI 1.05-2.93), poor exercise capacity (OR = 1.61; 95% CI 1.05-2.47), and inducible ischemia (OR = 1.49, 95% CI 0.99-2.24). The Glu37Asp (CC genotype) caused a 24-fold decrease in affinity for NADH and a 2.3-fold reduction in maximal renalase enzymatic activity.ConclusionsA functional missense polymorphism in renalase (Glu37Asp) is associated with cardiac hypertrophy, ventricular dysfunction, poor exercise capacity, and inducible ischemia in persons with stable coronary artery disease. Further studies investigating the therapeutic implications of this polymorphism should be considered.
Haemophilus influenzae Rd Lacks a Stringently Conserved Fatty Acid Biosynthetic Enzyme and Thermal Control of Membrane Lipid Composition

The organization of the fatty acid synthetic genes of Haemophilus influenzae Rd is remarkably similar to that of the paradigm organism, Escherichia coli K-12, except that no homologue of the E. coli fabF gene is present. This finding is unexpected, since fabF is very widely distributed among bacteria and is thought to be the generic 3-ketoacyl-acyl carrier protein (ACP) synthase active on long-chain-length substrates. However, H. influenzae Rd contains a homologue of the E. coli fabB gene, which encodes a 3-ketoacyl-ACP synthase required for unsaturated fatty acid synthesis, and it seemed possible that the H. influenzae FabB homologue might have acquired the functions of FabF. E. coli mutants lacking fabF function are unable to regulate the compositions of membrane phospholipids in response to growth temperature. We report in vivo evidence that the enzyme encoded by the H. influenzae fabB gene has properties essentially identical to those of E. coli FabB and lacks FabF activity. Therefore, H. influenzae grows without FabF function. Moreover, as predicted from studies of the E. coli fabF mutants, H. influenzae is unable to change the fatty acid compositions of its membrane phospholipids with growth temperature. We also demonstrate that the fabB gene of Vibrio cholerae El Tor N16961 does not contain a frameshift mutation as was previously reported.
Guided wave absorption and fluorescence in epitaxial Er:BaTiO3 on MgO

We report on the observation of ,1.54 mm guided wave absorption and fluorescence in channel waveguides fabricated in erbium-doped thin-film epitaxial BaTiO3. Luminescence transient measurements indicate that the relaxation of the excited Er ions is dominantly radiative. q 2000 Elsevier Science S.A. All rights reserved.
The Hispanic Community as a Resource for a Practical Spanish Program

The present article explains in detail how a Spanish Practicum course was conceived and functions at Lewis and Clark College. The purpose of the course is to use students of Spanish as English tutors for Spanish-speaking individuals on campus and in the community. The latter is achieved by working with several agencies which provide services to Hispanics. Besides receiving credit, the participating students benefit culturally and linguistically from their intercultural experience. The Spanish curriculum is also enhanced by the addition of a practical course which establishes links between the department, the school, and a sector of the community.
Imminence of peak in US coal production and overestimation of reserves

Abstract Coal is the bulwark of US energy production making up about a third of all energy produced and about half of its electricity generation capacity, over the last decade. Current energy policy in the Unites States assumes that there is at least a century of coal remaining within the nation that can be produced at the current rate of consumption. This assumption is based on the large reported coal reserves and resources. We show that, in coal-producing regions and nations, historically reported reserves are generally overestimated by a substantial magnitude. We demonstrate that a similar situation currently exists with US reserves. We forecast future US coal production, in both raw tonnage and energy, using a multi-cyclic logistic model fit to historical production data. Robustness of the model is validated using production data from regions within the US, as well as outside, that have completed a full production cycle. Results from the model indicate maximum raw tonnage coal production will occur in a time window between the years 2009 and 2023, with 2010 being the most likely year of such a maximum. Similarly, energy production from coal will reach a maximum in the years between 2003 and 2018, with 2006 being the most likely year of maximum occurrence. The estimated energy ultimate recoverable reserves (URR) from the logistic model is 2750 quadrillion BTU (2900 EJ) with 1070 quadrillion BTU (1130 EJ) yet to be mined, while the estimated raw tonnage URR is 124 billion short tons (112 Gt) with 52 billion short tons yet (47 Gt) to be mined. This latter value is merely a fifth of the long held estimate of 259 billion short tons (235 Gt).
An Adaptive Index Structure for High-Dimensional Similarity Search

A practical method for creating a high dimensional index structure that adapts to the data distribution and scales well with the database size, is presented. Typical media descriptors are high dimensional and are not uniformly distributed in the feature space. The performance of many existing methods degrade if the data is not uniformly distributed. The proposed method offers an efficient solution to this problem. First, the data's marginal distribution along each dimension is characterized using a Gaussian mixture model. The parameters of this model are estimated using the well known Expectation-Maximization (EM) method. These model parameters can also be estimated sequentially for on-line updating. Using the marginal distribution information, each of the data dimensions can be partitioned such that each bin contains approximately an equal number of objects. Experimental results on a real image texture data set are presented. Comparisons with existing techniques, such as the VA-File, demonstrate a significant overall improvement.
simpleIO: a Java package for novice interactive and graphics programming

This paper describes how to incorporate user interactivity and graphics into a first course in computer science. Problems and alternative solutions are discussed. A Java package called simpleIO that we developed is presented. It allows novice programmers to build simple GUI -based programs while maintaining good design principles. The package includes methods for requesting data from the user including integers, reals, string and Booleans. It also supports simple menus, graphics displays and text file handling.
Accurate Thermal Analysis Considering Nonlinear Thermal Conductivity

The increase in packing density has led to a higher power density in the chip which in turn has led to an increase in temperature on the chip. Temperature affects reliability, performance and power directly, motivating the need to accurately simulate the thermal profile of a chip. In literature, thermal conductivity is assumed to be a constant in order to obtain a linear system of equations which can be solved efficiently. But thermal conductivity is a nonlinear function of temperature and for silicon it varies by 22% over the range 27-80/spl deg/ C (McConnell et al., 2001). If the nonlinearity of the thermal conductivity is ignored the thermal profile might be off by 10/spl deg/ C. Thus to get an accurate thermal profile it is important to consider the nonlinear dependence of the thermal conductivity on temperature. In this paper the nonlinear system arising out of considering the nonlinear thermal conductivity is solved efficiently using a variant of Newton-Raphson. In this paper we also study the abstraction levels under which the approximation of a periodic source by a DC source is valid.
Composite Microstructure of Spider ( Nephila Clavipes ) Dragline

Dragline fibers collected at a controlled silking rate from Nephila clavipes spiders were studied by analytical transmission electron microscopy (TEM). The physical microstructure consists of irregularly-shaped β-sheet crystallites (approx. 70–100 nm in diameter, and comprising approx. 50 volume per cent) in an amorphous matrix. Electron diffraction from single crystallites indicates an orthogonal unit cell with space group P21; the lattice parameters are a = 13.31 A (inter-sheet repeat), b = 9.44 A (inter-chain repeat within β-sheets) and c = 20.88 A (intra-chain repeat). The crystallites are not truly periodic structures having long range positional order, but are better described as non-periodic layered structures, similar to the ordered structures formed when liquid crystalline random copolymers solidify. Electron energy loss spectroscopy (EELS) reveals chemical microstructure in the fibers. The matrix contains bands (approx. 200 nm wide) of alternately higher and lower nitrogen content. This variation cannot be explained in terms of known protein domains alone, and may reflect the presence of retained small-molecule species from secretory granules. Calcium is localized uniquely to the crystallites (at a concentration of approx. one calcium atom per 120 amino acid residues, as measured by inductively coupled plasma spectroscopy). Varying the calcium content may be one mechanism by which the spider can tailor the evolution of the microstructure, and hence the physical properties of the silk fiber.
Tapping the near-infrared spectral region with bacteriochlorin arrays

Bacteriochlorophylls—natural pigments for absorption of near-infrared (NIR) light—underlie light-absorption and energy transduction in photosynthetic bacteria. Capturing and utilizing NIR light is valuable in fields ranging from artificial photosynthesis to photomedicine (photodynamic therapy, imaging, and diagnostics). The desired photochemical features may be best elicited with multicomponent architectures that support efficient excited-state energy and/or electron transfer, yet few such arrays containing bacteriochlorins (the core chromophore of bacteriochlorophylls) are known. This review outlines three synthetic approaches toward bacteriochlorins, surveys all known bacteriochlorin arrays, and compares molecular design strategies for light-harvesting arrays containing bacteriochlorinsversus (the better known) porphyrins.