cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of La3+-Promoted Co/SiO2Catalysts

Abstract In order to assess the distribution and the promotional effects of La 3+ , a characterization study has been performed on a series of La 3+ -promoted 20 wt% Co/SiO 2 catalysts of varying La : Co atomic ratios (0, 0.05, 0.1, 0.2, 0.3, 0.5, and 0.75) prepared by impregnation of prereduced and passivated Co/SiO 2 in order to minimize effects of promotion on Co particle size distribution. La 3+ was found to be well dispersed over the Co/SiO 2 catalyst. However, it did not appear to be evenly distributed on the Co metal surface. From temperature programmed reduction, low La 3+ loadings (La/Co ≤ 0.2) were found to moderate the strong Co–support interactions resulting from aqueous impregnation of Co/SiO 2 and to improve the reducibility of the Co oxide. [Aqueous impregnation of prereduced Co/SiO 2 has been shown earlier to result in the formation of Co silicates (Haddad, G. J., and Goodwin, J. G., Jr., J. Catal . 157, 25 (1995))]. On the other hand, high La 3+ loadings (La/Co ≥ 0.5) appeared to induce La–Co compound and/or nonreducible Co-silicate formation, possibly due to the higher pH of the impregnating solution. The results indicate the multiple effects that promoters may have on supported metal catalysts. In addition to possibly affecting reaction on the sites, they may act to modify significantly the structure of the metal catalyst, for example by moderating metal–support interactions. Obviously, one expects that promoted catalysts prepared directly from precursors may exhibit large differences in metal dispersion. However, even when promoted catalysts are prepared from a precalcined or prereduced supported metal catalyst, the act of adding a promoter may have as much an effect in modifying the catalyst as the final presence of the promoter.
Theory of spin-relaxation processes

Abstract The relaxation properties of a spin system weakly coupled to lattice degrees of freedom are described using an equation of motion for the spin density matrix. This equation is derived using a general weak coupling theory which has been previously developed. To second order in the weak coupling parameter, the results are in agreement with those obtained by Bloch, Wangsness and Redfield but the derivation does not make use of second order perturbation theory for short times. The derivation can be extended beyond second order and ensures that the spin density matrix relaxes to its exact equilibrium form to the appropriate order in the weak coupling parameter.
An electrostatic-surface stability interpretation of the ``hydrophobic'' force inferred to occur between mica plates in solutions of soluble surfactants

Abstract We analyse the data on the “hydrophobic” forces between mica surfaces immersed in solutions of the surfactant CTAB. For the particular regime where these “attractive” forces are not directly seen but are only inferred to exist because of a deviation from expected repulsive forces, we find that there is a strong correlation between the surface electrostatic potential that appears to be the source of electrostatic repulsion and the force at collapse that is used to infer the hypothetical attractive hydrophobic interaction. A simple phenomenological model is presented that takes note of this previously neglected internal correlation. From this model we suggest that, at least in the case of CTAB, the collapse is probably not due to the balance between electrostatic and Van der Waals or “hydrophobic” attractive forces; it is due rather to a shift in the balance between the inter- and intra-surface forces that govern surfactant deposition. Such a view, based on the critical desorption or rearrangement of lipids or other solutes, is consonant with recent reports that the earlier experimental results of Pashley and Israelachvili are not reproduced when one uses purified CTAB. Recognition of solute desorption and adsorption might provide a key to the puzzling data where very long-range net attractive forces are observed but where these forces change with the activity of solutes in the intervening solution.
Forced association between higher plant and bacterial cells in vitro

SYMBIOTIC associations with microorganisms enable many plant species to utilise molecular nitrogen1–3. In vitro systems have been developed to study some of these natural associations4–7, and here we have attempted to define an experimental system for investigating the possibility of extending the nitrogen-fixing symbiosis to additional crop species. We used tissue culture techniques to force an association between the free-living nitrogen-fixing bacterium, Azotobacter vinelandii and cells of a carrot, Daucus carota cv. Danver's Half Long. The resulting composite callus proliferates slowly on a defined synthetic medium lacking combined nitrogen. In these conditions carrot cells which have not formed an association with Azotobacter are unable to survive.
Prefrontal Neuronal Responses during Audiovisual Mnemonic Processing

During communication we combine auditory and visual information. Neurophysiological research in nonhuman primates has shown that single neurons in ventrolateral prefrontal cortex (VLPFC) exhibit multisensory responses to faces and vocalizations presented simultaneously. However, whether VLPFC is also involved in maintaining those communication stimuli in working memory or combining stored information across different modalities is unknown, although its human homolog, the inferior frontal gyrus, is known to be important in integrating verbal information from auditory and visual working memory. To address this question, we recorded from VLPFC while rhesus macaques (Macaca mulatta) performed an audiovisual working memory task. Unlike traditional match-to-sample/nonmatch-to-sample paradigms, which use unimodal memoranda, our nonmatch-to-sample task used dynamic movies consisting of both facial gestures and the accompanying vocalizations. For the nonmatch conditions, a change in the auditory component (vocalization), the visual component (face), or both components was detected. Our results show that VLPFC neurons are activated by stimulus and task factors: while some neurons simply responded to a particular face or a vocalization regardless of the task period, others exhibited activity patterns typically related to working memory such as sustained delay activity and match enhancement/suppression. In addition, we found neurons that detected the component change during the nonmatch period. Interestingly, some of these neurons were sensitive to the change of both components and therefore combined information from auditory and visual working memory. These results suggest that VLPFC is not only involved in the perceptual processing of faces and vocalizations but also in their mnemonic processing.
PTH improves titanium implant fixation more than pamidronate or renutrition in osteopenic rats chronically fed a low protein diet.

Summary We evaluated the effects of parathyroid hormone (PTH), pamidronate, or renutrition on osseointegration of titanium implants in the proximal tibia of rats subject to prolonged low-protein diets. PTH improved mechanical fixation, microarchitecture, and increased pull-out strength. Pamidronate or renutrition had lesser effects. PTH can thus improve implant osseointegration in protein-malnourished rats.
Analyzing Optimization Techniques for Power Efficiency on Heterogeneous Platforms

Graphics processing units (GPUs) have become widely accepted as the computing platform of choice in many high performance computing domains. The availability of programming standards such as OpenCL are used to leverage the inherent parallelism offered by GPUs. Source code optimizations such as loop unrolling and tiling when targeted to heterogeneous applications have reported large gains in performance. However, given the power consumption of GPUs, platforms can exhaust their power budgets quickly. Better solutions are needed to effectively exploit the power-efficiency available on heterogeneous systems. In this work, we evaluate the power/performance efficiency of different optimizations used on heterogeneous applications. We analyze the power/performance trade-off by evaluating energy consumption of the optimizations. We compare the performance of different optimization techniques on 4 different Fast Fourier Transform implementations. Our study covers discrete GPUs and shared memory GPUs (APUs), and includes hardware from AMD (Llano APUs and the Southern Islands GPU), Nvidia (Kepler) and Intel (Ivy Bridge) as test platforms. The study identifies the architectural and algorithmic factors which can most impact power consumption. We explore arange of application optimizations which show an increase in power consumption by 27%, but result in more than a 1.8Xspeedup in performance. We observe a 11% variation in energy consumption among different optimizations. We highlight how different optimizations can improve the execution performance of a heterogeneous application, but also impact power efficiency of the application.
Extracellular matrix made by bone marrow cells facilitates expansion of marrow-derived mesenchymal progenitor cells and prevents their differentiation into osteoblasts

We cultured MSCs on an ECM made by bone marrow cells to attempt to reconstitute the MSC niche. This ECM promoted replication of mesenchymal progenitors and retention of their multipotentiality. We conclude that the marrow ECM facilitates expansion of mesenchymal progenitors and hypothesize that it plays an important role in the maintenance of MSC stemness. Introduction: Mesenchymal colony-forming cells of the bone marrow comprise mesenchymal stem cells (MSCs) and their transit amplifying progeny, which we term mesenchymal colony-forming units (MCFUs). These progenitors undergo self-renewal and can differentiate into many different cell types including osteoblasts. However, they lose their unique properties when cultured on tissue culture plastic. This indicates that a critical feature of the marrow microenvironment that facilitates retention of stem cell properties is missing in such culture systems. In other tissues, the extracellular matrix (ECM) forms part of the specialized niche that controls stem cell behavior. Therefore, we examined whether a marrow cell–derived ECM promotes retention of the stem cell characteristics of MCFUs in vitro. Materials and Methods: A cell-free ECM was prepared from cultured murine marrow adherent cells. The replication and multipotentiality of murine MCFUs maintained on this marrow cell–derived ECM were examined in vitro and in vivo and compared with the behavior of MCFUs maintained on plastic. Results: The marrow cell–derived ECM was made up of collagen types I, III, and V, syndecan-1, perlecan, fibronectin, laminin, biglycan, and decorin, similar to the composition of the marrow ECM. This ECM preparation promoted MCFU replication, restrained their “spontaneous” differentiation toward the osteoblast lineage, and preserved their ability to differentiate into osteoblasts or adipocytes. Moreover, transplantation of MCFUs expanded on the marrow cell–derived ECM into immunocompromised mice generated five times more bone and eight times more hematopoietic marrow compared with MCFUs expanded on plastic. Conclusions: The marrow ECM facilitates expansion of MCFUs in vitro while preserving their stem cell properties. We hypothesize that the ECM made by bone marrow cells plays an important role in the maintenance of MSC function.
Development of thin-film Si HYBRID solar module

The device current–voltage (I–V) characteristics of thin-film silicon stacked tandem solar modules (HYBRID modules), consisting of a hydrogenated amorphous silicon (a-Si:H) cell and a thin-film crystalline silicon solar cell (mc-Si), have been investigated under various spectral irradiance distributions. The performance of the HYBRID module varied periodically in natural sunlight due to the current-limiting property of the HYBRID module and the environmental effects. The behavior based on the current-limiting property was demonstrated by the modelling of the I–V curves using the linear interpolation method for each component cell. The improvement of the performance for the HYBRID module in natural sunlight will also be discussed from the viewpoint of the device design of the component cells.
Business‐to‐business market making on the Internet

Explores the emergence of market‐making as a viable business model on the Internet. Exploratory field research suggests that business‐to‐business marketers with international audiences might find this environment most in need of the roles an electronic middleman can play. Examines the critical factors which influence success for these new market makers (MMs) and the trade‐offs they must make to ensure that they reach critical mass in the short‐term and create a sustainable position in the long term. Concludes with a set of recommendations to guide would‐be MMs in making these strategic choices.
Intraoperative ultrasonography improves identification of recurrent thyroid cancer

Abstract Background. Surgical resection is the only curative treatment option for locoregional recurrence of well-differentiated thyroid cancer that does not trap radioiodine. We hypothesized that intraoperative ultrasonography would aid in the localization of recurrent thyroid cancer and would enhance the ability to perform a complete resection. Methods. Between June 2000 and October 2001, 13 patients with recurrent, scan-negative, papillary thyroid cancer were explored by using intraoperative ultrasonography. Results. All patients had identification and resection of recurrent papillary thyroid cancer. Eleven patients had a complete resection, and 2 patients had incomplete resection as a result of local invasion. Ultrasound was required for identification of tumor in 7 patients and included all patients with a history of external beam radiotherapy. In 6 of these 7 patients, the tumor was paratracheal or invasive into the trachea or thyroid cartilage. In 11 patients with detectable serum thyroglobulin preoperatively, the level demonstrated a decline in 10 patients and became undetectable in 7 patients. Conclusions. Intraoperative ultrasonography is a useful method to identify nonpalpable, locoregional recurrences of thyroid cancer. Ultrasound was particularly helpful in patients who had previous external beam radiotherapy and in the identification of tumor nodules of 20 mm or less that were invasive or adherent to the airway. (Surgery 2002;132:924-9.)
Do Team Sports Matter for Black Males

AbstractThe purpose of this study is to explore Black males’ participation in team and individual sports at the high school level and the differential direct, indirect, and total effects on their college attendance using a large, nationally representative, longitudinal database (ELS: 2002). Previous studies (e.g. ; ) have claimed that the type of sport makes a significant difference in student outcomes such as social adjustment and social self-efficacy. While such outcomes may indirectly affect the college attendance behaviors of participants, it was not the goal of such studies to make such connections. This study, however, endeavors to make explicit the effect, if any, that the type of sport has on college attendance within the context of previously noted antecedents (e.g. socioeconomic status, academic achievement, and student educational expectations) to educational attainment. Two different hypotheses have emerged from the literature with regard to sports participation in general: 1) Sport-impedes-mo...
Organic thin films based sensor applications

Organic semiconductors, such as pentacene, are particularly interesting because of its potential for various applications including thin film transistors (TFTs), electronic papers, radio frequency identification cards (RFIDs), and sensors. In this paper, we review recent progress in organic electronics with emphasis on their applications for sensing devices, and investigate the morphologies of pentacene films deposited on SiO2 and Si surfaces at different substrate temperatures. Scanning electron microcopy (SEM) micrographs from a nominally 50nm-thick pentacene film on SiO2 indicate that the grain sizes of pentacene film increase with an increase in substrate temperature. In addition, the grain size on clean silicon grown at a substrate temperature of 100 degrees C is markedly larger that on SiO2, ranging 10~20μm. Based on this morphological investigation on pentacene films, various types of organic sensors and devices with conjunction with interdigitated, gated and ungated structures are presented.
Allied Health Students' Learning-Styles Identified with Two Different Assessments

This research identified and compared the learning styles of 154 ethnically diverse, upper division undergraduate and graduate students in Allied Health utilizing the Building Excellence (BE) (Rundle & Dunn, 2000) and the Productivity Environmental Preference Survey (PEPS) (Dunn, Dunn, & Price, 1996). Relationships among age, class standing, ethnicity, gender, and learning style also were examined. Correlation analyses indicated relationships between students' learning-style elements (p < .001), with large effect sizes for Sound, Light, Temperature, Seating Design, Intake, Time-of-day and Mobility, Auditory, Tactile, and Kinesthetic preferences. Gender related learning-style characteristics revealed female preferences for learning by listening and male preferences for cooler temperatures, frequent movement, and learning in a pair or team during instruction. Analyses of variance and follow-up post hoc tests revealed significant age-related learning-style differences for Structure, Intake, Mobility, Early-M...
Semiconductor-coated deep subwavelength spoof surface plasmonic waveguide for THz and MIR applications

We propose integrated waveguides for terahertz (THz) and mid-infrared (MIR) applications on wafer platform. Based on the prototype of spoof plasmonic waveguides consisting of textured metallic surface, we explore the possibility of coating periodic metallic pattern with silicon (at 0.6 THz) or germanium (at MIR region of 30 THz) to further shrink the relative mode size of propagation spoof plasmonic waves. Numerical modeling via 3D finite-difference time-domain (FDTD) has shown deep sub-wavelength mode confinement in transverse directions to smaller than λ/50 by λ/50, with an estimated propagation loss of less than 0.1 dB for each repetitive unit.
Russia's Energy Policy: A Framing Comment

A prominent specialist on the Russian economy provides a framing comment on two preceding papers entitled "Russia's Energy Policy" (by Vladimir Milov, Leonard Coburn, and Igor Danchenko) and "Russia's Energy Policy: A Divergent View" (by Matthew J. Sagers). The author argues that Russia's current energy policy should be viewed as an outcome of competition between three overlapping programs. In this context, he identifies three policy models—the old Soviet, the liberal or oligarchic, and the most recent state capitalist. The latter is currently supported by President Putin, who prioritizes diversification of the country's economy at the expense of diminished investments in the oil and gas sector. Journal of Economic Literature, Classification Numbers: L71, O13, Q40, Q48. 2 tables, 2 figures, 22 references.
An automated reasoning system

This paper is an introduction to an automated reasoning program developed at Northern Illinois University and Argonne National Laboratory over the past nine years. Recently the program has reached the stage where it can be considered a useful research tool in a variety of disciplines. It has solved open problems in mathematics and participated in the design of new electronic circuits. Here we describe the general types of capabilities provided to the user by the program and give examples of how they are currently being used in diverse areas of investigation.
High chromium contents in Tertiary coal deposits of northwestern Washington — A key to their depositional history

Abstract Chromium contents obtained from 20 coal and 5 associated rock samples collected from the basal part of the Eocene Chuckanut Formation, in Skagit and Whatcom counties, northwest Washington, range between 30 and 300 ppm (mean 120 ppm whole-coal basis). The lenticular coals, ranging in rank from subbituminous to anthracite, and with an ash content of 12–46%, crop out along the western flank of the Cascade Range. Results of X-ray diffraction analysis of low-temperature ash show that the mineral matter in the coal samples consists predominantly of quartz and clay (kaolinite, illite and chlorite group). However, accessory minerals, isolated from the coal samples and analyzed by X-ray diffraction, scanning electron microscope and optical methods, contain angular fragments and euhedral crystals of the spinel group (chromite, magnetite and trevorite ), kaolinite-serpentine group (antigorite and chrysotile), chlorite group, amphibole group and pyroxene group minerals (augite, diopside and enstatite), all of which are commonly enriched in chromium. Although associated primarily with the inorganic fraction of the coal, concentrations of chromium in the samples show no statistically significant correlation with ash content. Localized concentrations of chromium in the coal are the result of natural contamination from the alteration of detrital chromium-bearing mineral grains introduced into the peat-forming mires from nearby Jurassic ophiolite bodies. The coals formed in the early Eocene, in rapidly subsiding small basins that developed during the uplift and erosion of the pre-Tertiary ophiolite terrain. Scattered bodies of source rock, random distribution of chromium-bearing minerals within the coal and sample heterogeneity account for the variation in Cr contents of the samples.
The elements of candidate reputation: The effect of record and credibility on optimal spatial location

We build a model of two-candidate elections in which voters judge candidates on the basis of how well their announced campaign positions correspond with their records. Given different records, the candidates will adopt different campaign positions. Two types of reputational advantage are analyzed: proximity of the candidate's record to the median voter's ideal point, and the range of campaign positions that a candidate may adopt and still retain some credibility with the voters.
Principles of evolutionary educational psychology

Abstract Evolutionary educational psychology is the study of the relation between evolved systems of folk knowledge and inferential and attributional biases as these relate to academic learning in modern society. Following discussion and illustration of the mechanisms of natural selection and their application to human motivational, cognitive, and behavioral evolution, the basic premises and principles of evolutionary educational psychology are outlined. The gist is that the evolved cognitive systems and inferential biases that define folk knowledge are not sufficient for academic learning, but, at the same time, are the foundation from which academic competencies are built. A theoretical frame outlining the relation between folk knowledge and academic development is proposed and implications for motivational issues and instructional practices are detailed.
Satellite sweeping of electrons at Neptune and Uranus

Knowledge of satellite sweeping parameters at Neptune and Uranus, and of their functional dependences on particle energy and pitch angle, can be critical in the proper identification of parent absorbers for observed absorption signatures in regions where OTD (offset, tilted dipole) models are valid representations of the measured magnetic fields. In this paper, critical electron energies are calculated for longitudinal drift resonance, snowplow (i.e., strong) absorption, leapfrog, and corkscrew effects, using a reduced version of OTD that neglects nonaxial dipole offsets. Earlier analytic work on sweeping rates is extended to give the radial dependence of these rates within the minimum-L region and to set limits on diffusion of electrons with the simplifying approximation that leapfrog effects are ignored.
Measuring psychosocial distress and parenting concerns among adults with cancer: the Parenting Concerns Questionnaire.

PURPOSE We conducted a two phase, mixed methods study to develop a Parenting Concerns Questionnaire (PCQ) for adults with cancer. Limited information about this area of psychosocial distress highlights the need for a measurement tool that can identify adult oncology patients with heightened parenting concerns who could benefit from additional intervention.
African Origins of the Mandates Idea

As the Allied troops overran the German colonies the First World War British publicists began to debate whether these territories should be returned to Germany, placed under some sort of international control, or sliced up and annexed by the conquering powers. There was little support for the proposal to hand diem back to Germany. In part this was because of the widely held belief that the Germans were guilty of “atrocities” in Africa no less appalling than those committed in King Leopold's Congo Free State before it was annexed by Belgium in 1908. The real question was whether the German colonies should be annexed or “internationalized.” On the left of the political spectrum the Independent Labor Party urged international administration as a means of uprooting imperialism as a cause of war. On the right the conservative press advocated annexation pure and simple as a means of preventing war by strengthening the British Empire. The mandates system itself was a compromise between these opposing ideas. It was viewed by those on the left as a limited triumph in the cause of internationalization; and by those on the right as annexation in all but name.
Preexposure to the UCS affects avoidance conditioning

Four groups of hooded rats received 100 trials of avoidance training per day for 10 days in a four-way shuttlebox. The animals were assigned to experimental groups as follows: Group 1 received 25 escape trials immediately preceding avoidance training on Day 1. Group 2 were placed in the chamber on Day 1 for the equivalent time required for escape pretraining. Group 3 animals were exposed to the 25 escape trials on the day preceding the beginning of avoidance training. Group 4 received avoidance training only. All groups acquired the avoidance response to a similar level in the first two sessions. Significant group effects [F(3,20) = 14.36, p <.01] were seen, with the performance of Group 1 decreasing on Day 3 and remaining lower over the 10 days of the experiment. Thus, a delayed long-term interference effect was found when escape pretraining immediately preceded avoidance training.
The closed-loop stability of power converters with an integrating controller

A theory is developed to predict the stability characteristics of static converters as a function of the controlled-firing angle for closed-loop systems using an integrating controller. The controlled quantity can be either the output voltage or current. Revealed in the analysis was how the degree of stability is dependent on the operating point, the waveform and pulse number of the supply, the commutating reactance, and the method of modulating the firing angle. The factors that determine stability are related to the step change in the output voltage waveform at the instant of switching. In practical application of the theory, the closed-loop performance can be improved by suitably shaping the modulating function or `firing wave'. It is found that the optimum shape of the firing wave is not the same shape that produces a linear open-loop voltage gain.
Pandemonium and Babel : Architectural Hierarchy in Paradise Lost

L'organisation des sources du poeme de Milton : de Nemrod a Satan, de l'architecture babelienne a l'architecture du pandemonium
Does treatment of childhood congenital adrenal hyperplasia with prednisone adversely affect final height

Does treatment of childhood congenital adrenal hyperplasia with prednisone adversely affect final height?
Chronic urticaria: Review of nonsedating H1 antihistamines in treatment

Antihistamines are the drugs of choice in the symptomatic relief of chronic urticaria; however, the usefulness of classic antihistamines has been limited by side effects, especially daytime sedation. In the 1980s a new class of antihistamines has been developed that maintains effectiveness and produces less sedation. This review analyzes each of the new nonsedating antihistamines and evaluates its clinical efficacy, safety, and convenience in the treatment of chronic urticaria.
The Record of Impact Cratering on the Great Volcanic Shields of the Tharsis Region of Mars

The spatial density of impact craters larger than 100 m on the four great volcanic shields in the Tharsis region is analyzed, assuming that each observed crater population represents the total formed since the local surface was last renewed. Previous investigations of this type are reviewed, problems encountered in those studies are discussed, and an attempt is made to overcome these problems by applying explicit criteria for the separation of craters smaller than approximately 1 km in diameter according to their origin and by ignoring larger craters. Relative ages are determined by comparing crater populations at a common diameter, and such comparisons are carried out for six populations on Arsia Mons, one population on Pavonis Mons, several craters on Ascraeus Mons, and two populations on Olympus Mons. The results, presented in terms of 'crater ages', indicate that most dated surfaces on the great shields range in age from 0.5 to 1.2 billion years, that the eruption patterns of the volcanoes are similar to those of the Hawaiian basaltic shields, and that the most frequently renewed surfaces are on the middle-to-lower flanks as well as within the summit calderas. The youngest surfaces are estimated to date from the period between 0.5 billion years ago and the present; the oldest dated surfaces are shown to suggest that the volcanoes had attained essentially their present sizes over 1 billion years ago.
Recent advances in photorefractive two-beam coupling

Abstract In this article, we review two approaches that we have taken to improve photorefractive two-beam coupling: (1) the enhancement of the effective trap density in a well-known inorganic photorefractive crystals (KNbO 3 :Fe) and (2) the improvement of a relatively new concept of organic–inorganic hybridized liquid crystal cells.
Sources of error in quantitative coronary angiography

Many studies have reported the accuracy of quantitative coronary angiography (QCA) based on experiments using moderated-size phantoms imaged under unrealistic radiographic conditions. However, these observations may not be generalizable to the setting of clinical angiography. To determine QCA accuracy in a realistic radiographic setting and evaluate the impact of the x-ray system line spread function, plexiglass phantoms were imaged inside and out of a human thorax. A realistic radiographic background was associated with a 38% increase in variability of results (p < 0.05). Low concentrations of contrast and large image intensifier input screens were associated with significantly larger errors and variability in results (p < 0.05). There was a systematic overestimation of diameter in the smallest phantom. A mathematical model of the x-ray line spread function was developed that explains the observed overestimation of the smallest phantom and provide a rational approach for correction of the line spread function for QCA. Many factors encountered in clinical coronary angiography such as nonuniform radiographic background, low concentrations of contrast, and small vessel diameters have a significant adverse impact on the accuracy and/or variability of gradient-based edge detection QCA systems. © 1993 Wiley-Liss, Inc.
Identification of low density lipoprotein receptor binding domains of human apolipoprotein B-100: a proposed consensus LDL receptor binding sequence of apoB-100.

Summary The human liver apoB-100 gene cloned in the λgt-11 expression vector expresses fusion proteins reacting with apoB antibodies. A fusion protein induced from a apoB-λgt-11 clone reacted with apoB-100 monoclonal antibodies known to block the binding of LDL to the LDL receptor. The fusion protein contains an amino acid sequence domain enriched in positively charged residues which is complementary to the negatively charged amino acids present in the consensus LDL receptor binding domain. This sequence of apoB-100 is proposed as a binding domain for the interaction with the LDL receptor. Comparison of derived amino acid sequences from the entire structure of apoB-100 molecule revealed several similar domains enriched in positively charged amino acids. A consensus sequence of the potential LDL binding domain was identified which contained positively charged amino acids at positions 1, 5 and 8 and a loop of 8–11 amino acids followed by two adjacent positively charged amino acids. These results are interpreted as indicating that there are several potential LDL receptor binding domains in apoB-100.
Refinements in the rapid isolation of glutamine synthetase from Escherichia coli.

Abstract In an earlier paper, we described a procedure for the isolation of glutamine synthetase and the protein product of the groE gene (p groE ) by polyethyleneimine precipitation and affinity chromatography on a Blue Dextran column ( Z. F. Burton and D. Eisenberg, 1980, Arch. Biochem. Biophys. 205 , 478–488 ). Subsequently we found that several of the steps can be omitted when isolating glutamine synthetase. Two procedures are described which are very rapid and quantitative for the recovery of glutamine synthetase activity and which are useful for handling quantities of cells at least up to 500 g.
Analysis of a new constitutive mutation at OL which deleteriously affects the bacteriophage λ lytic cycle

The OLc allele v2s described in this report limits the formation of progeny phage. The limitation of phage production is both cis and trans dominant and is expressed in homoimmune as well as heteroimmune infections. N operon expression is elevated and continuous throughout the period of the λv2s lytic cycle but total phage DNA synthesis is not significantly affected. The v2s allele is similar to the v2 allele in retaining partial sensitivity to cI repressor but is significantly less sensitive to Cro. The limited number of progeny phage produced in λv2s infections is due to residual cI repressor regulation in the relative absence of Cro control at OL. Normal burst sizes are observed in λv2sORc infections and λv2sλORC mixed infections suggesting the hypersynthesis of Cro accorded by ORc alleles allows a level of Cro accumulation sufficient to overcome the effects of the v2s allele. The similarities between λv2s and λcI−cro− infections indicate regulation of transcription originating at PL is essential for a successful lytic cycle.
Barriers Beyond the Partners: Bureaucraticand Political Constraints to Implementing Joint Forest Management in Tamil Nadu, India

Whereas past research has treated co-management of common pool resources as if villagers and project implementing authorities were the only relevant actors, numerous external factors beyond the control of these two partners create barriers to successful co-management. This paper draws on discussions with Forest Department officials to examine the influence of these forces on the outcomes of Joint Forest Management (JFM) in Tamil Nadu, India. An empirical inquiry into the operational aspects of JFM indicates the important roles of political parties, powerful people, and other state institutions and functionaries as well as the flow of foreign funding. Further, the strong demand by local people for socio-economic development interventions as opposed to improvement of degraded forests belittles the role of the Forest Department relative to other departments. Numerous other conditioning factors and relationships are explored. The authors call for reforms in public governance to allow better participation of all the actors involved for this participatory management approach to succeed and sustain.
A fast Bayesian reconstruction algorithm for emission tomography with entropy prior converging to feasible images

The development and tests of an iterative reconstruction algorithm for emission tomography based on Bayesian statistical concepts are described. The algorithm uses the entropy of the generated image as a prior distribution, can be accelerated by the choice of an exponent, and converges uniformly to feasible images by the choice of one adjustable parameter. A feasible image has been defined as one that is consistent with the initial data (i.e. it is an image that, if truly a source of radiation in a patient, could have generated the initial data by the Poisson process that governs radioactive disintegration). The fundamental ideas of Bayesian reconstruction are discussed, along with the use of an entropy prior with an adjustable contrast parameter, the use of likelihood with data increment parameters as conditional probability, and the development of the new fast maximum a posteriori with entropy (FMAPE) Algorithm by the successive substitution method. It is shown that in the maximum likelihood estimator (MLE) and FMAPE algorithms, the only correct choice of initial image for the iterative procedure in the absence of a priori knowledge about the image configuration is a uniform field. >
Worth the Hype? The Relevance of Paid-For Analyst Research for the Buy-and-Hold Investor

The SEC Advisory Committee on Smaller Public Companies recommends paid-for research to fill the void created by declining sell-side coverage. Potential conflicts of interest inherent in paid-for research challenge this recommendation. We evaluate whether paid-for research provides value to investors or merely reflects hype. Analyses of one- and two-year ahead paid-for earnings forecasts fail to identify significant bias. Using a portfolio approach, favorable (unfavorable) paid-for recommendations yield positive (negative) stock returns at release, with upward (downward) drift over the following year. Regressing future stock returns on recommendations and valuation estimates using paid-for analysts’ forecasts yields similar results. Further, results fail to indicate significant differences in paid-for and matched sell-side research. Overall, our evidence suggests that paid-for research provides relevant information for the buy-and-hold investor that is comparable to that of matched sell-side research, providing empirical support for the SEC Advisory Committee recommendation.
Edge And Line Detection in Multidimensional Noisy Imagery Data

Detection of edges and lines in multidimensional data is an important operation in a number of image processing applications. The multidimensional picture function is a sampling of the underlying reflectance function of the objects in the scene with the noise added to the true function values. Edges and lines refer to places in the image where there are jumps in the values of the function or its derivatives. The multidimensional greytone surface is expanded as a weighted sum of basis functions. Using multidimensional orthogonal polynomial basis functions, expressions are developed for the coefficients of the fitted quadrautic and cubic surfaces. The parameters of the fitted surfaces are obtained when there is a rotation in the coordinate system. Assuming the noise is Gaussian, statistical tests are devised for the detection of significant edges and lines. Direction isotropic properties of the fitted surfaces are described. For computational efficiency, recursive relations are obtained between the parameters of the fitted surfaces of successive neighborhoods. Furthermore, experimental results are presented by applying the developed theory to multiband Landsat-Imagery Data.
A noise-reduction neural network as a preprocessing stage in the SVD based method of harmonic retrieval

A noise-reduction neural network is proposed as a preprocessing stage in the singular value decomposition (SVD)-based state-space approach to harmonic retrieval. By performing noise-reduction on the data set, the performance is improved of the various criteria available in the literature for identifying the significant singular values in the SVD of the estimated covariance matrix. Computer simulations performed using sampled sinusoids in white noise show that the network is capable of learning to perform noise reduction. >
Characterizing the departure process from a two server Markovian queue: a non-renewal approach

For large queueing network analysis the general computational approach is to utilize decomposition to facilitate computational tractability. To accomplish this individual analysis the input and output streams must be characterized. This usually is done via two-parameter characterizations: the process mean and a variance measure (most commonly the squared coefficient of variation SCV). In most approaches independent and identically distributed (i.i.d.) approximations are used. For multiple input streams and/or multiple (identical) servers, the assumptions of i.i.d. times between arrivals and, similarly, i.i.d. times between departures are particularly theoretically and computationally inaccurate. In this paper we develop a generator for the background multidimensional continuous time Markov chain associated with the inter-departure times for the associated multi-stream and multi-server Markovian queues (where inter-arrival times and service times are Coxian). This generator allows for the computation of the moments of the departure process and the lag-k correlations between successive k-separated departures.
AdDressing Missing Nodes as Missing Data in Dynamic Causal Modeling

Dynamic Causal Modeling (DCM) uses dynamical systems to represent the high-level neural processing strategy for a given cognitive task. The logical network topology of the model is specified by a combination of prior knowledge and statistical analysis of the neuro-imaging signals. Parameters of this a-priori model are then estimated and competing models are compared to determine the most likely model given experimental data. Inter-subject analysis using DCM requires considerable judgement on the part of the experimenter to decide on the validity of assumptions used in the modeling and statistical analysis; in particular, the dropping of subjects with insufficient activity in a region of the model and ignoring activations not included in the model. This manual data filtering is required so that the model's network size is consistent across subjects. A solution to this problem would ease using DCM in population studies and reduce potential sources of experimental bias. The paper describes and compares three different approaches to allow inter-subject comparisons by treating variation in the network size as a missing data problem. These approaches are compared with respect to accuracy in classifying and predicting subject DCMs using simulated data.
Response of a double-wedge base-isolation device

A novel base-isolation device is described and its performance is compared with that of a friction pendulum bearing. In its simplest form, the device consists of two wedges sliding on a horizontal plane in opposite directions and constrained from retreating by ratchets or bilinear dampers. The superstructure rests at the intersection of the two wedges. For a sufficiently large horizontal acceleration of the base, the structure starts to move up the inclined plane of one of the wedges, which remains fixed while the second wedge is slaved to follow the structure. As the direction of the base acceleration reverses, the process is reversed and the structure starts to climb on the second inclined plane while the first wedge follows. The overall result is that the horizontal acceleration of the structure is reduced with respect to that of the base and that kinetic energy associated with horizontal velocities is systematically transformed into potential energy. In the case of motion in a vertical plane, the device has the following advantages over a friction pendulum: (i) the sliding surface is linear instead of curved, (ii) kinetic energy is systematically transformed into potential energy during the strong ground motion, and (iii) the device is slowly self-centering. Copyright © 2004 John Wiley & Sons, Ltd.
Age at First Birth, Parity, and Post-Reproductive Mortality among White and Black Women in the US, 1982–2002

We investigate the relationship between the timing of first birth, parity, and women's risk of post-reproductive mortality over twenty-one years (1982-2002), among representative samples of black and white women in the United States. Data are taken from the National Longitudinal Survey of Mature Women. We find early childbearing to be associated with higher mortality among whites, while later childbearing is associated with higher mortality among blacks. The effect of age at first birth on white women's mortality is explained by background and mediating social, economic, and health related factors, but this effect remains robust for black women. In addition, childless white women have a higher risk of post-reproductive mortality than those with 2-3 children. High parity (6+ children) has a significant protective effect for blacks, though the effect is reduced with age. A similar protective effect of high parity becomes apparent among whites only after controlling for background and mediating characteristics. Findings are interpreted in light of the weathering hypothesis and from a life course framework that views women's fertility as adaptive to particular social and historical contexts.
The Private and Government Sides of Tanzanian Journalists

This article presents the evolution of Tanzania’s media with particular focus on the period of indigenous government control before the recent shift from such control to private ownership. While the history of the media is interesting in and of itself, it is presented to establish the journalistic ideology into which Tanzanian media practitioners were socialized as the result of the country’s adoption, upon receiving independence, of a one-party political system and a socialist economic system. This media history serves as a backdrop for the empirical portion of this paper. Using type of ownership (government, party, and private) as a classifying variable, the empirical study then captures Tanzanian journalists’ opinion profile with regard to private and government media traits. The journalistic ideology of the controlled period, wherein media played a role in national development, is apparent particularly in journalists’ attribution of traits to government and private media: The former will unify and dev...
The deterministic EPQ with partial backordering: A new approach

Several authors have developed models for the EOQ when only a percentage of stockouts will be backordered. Most of these models are complicated, with equations unlike those for the EOQ with full backordering. In this paper we extend work by Pentico and Drake [The deterministic EOQ with partial backordering: a new approach. European Journal of Operational Research 2008; in press] that developed equations for the EOQ with partial backordering that are more like those for the EOQ with full backordering to develop a comparable model for the EPQ with partial backordering.
Viscosity of nonpolar gaseous mixtures at normal pressures

The relationship between μ*ξ and TR for nonpolar gases at normal pressures is used to predict the viscosity for their mixtures. For such mixtures, pseudocritical temperatures are used to obtain TR. To establish ξm for a mixture, a binary interaction model has been applied that utilizes composition and the ξ values of the pure components. Viscosities have been calculated for twenty binary systems which include helium and hydrogen. These calculated values produce an average deviation of 1.97% for 148 compositions. This method was also applied to the helium-neon-argon ternary system at 100°C. to obtain for four mixtures examined an average deviation of 2.2%.