cssi/SciSciGPT-SciSciNet huggingface dataset:
Arsenic geochemistry in geothermal systems

Arsenic is an important trace constituent in geothermal fluids, ranging in concentration from less than 0.1 to nearly 50 ppm. An evaluation of published fluid analyses from geothermal systems indicates that the As content of the reservoir fluids varies inversely with PH2S and directly with temperature. Aqueous As species occur in two oxidation states, AsIII and AsV. AsIII predominates in the reservoir fluids, where H3AsO3 is inferred to be the dominant aqueous species. Both ASIII and AsV occur in hot spring fluids. The concentration of As in high-temperature reservoir fluids is regulated by reactions involving pyrite. Concentrations up to 3.8 weight percent As have been measured in pyrite from two systems. The erratic distribution of As in the samples studied is interpreted as resulting from local fluctuations in redox conditions. Arsenopyrite and other As minerals are undersaturated with respect to the high temperature fluids found in most reservoirs. In contrast, orpiment, realgar, As-rich stibnite and marcasite, and iron oxides control the deposition of As in hot spring environments. These minerals become stable in response to decreasing temperature and pH and increasing PO2.
Mixed-integer bilinear programming problems

This paper addresses a class of problems called mixed-integer bilinear programming problems. These problems are identical to the well known bilinear programming problems with the exception that one set of variables is restricted to be binary valued, and they arise in various production, location—allocation, and distribution application contexts. We first identify some special cases of this problem which are relatively more readily solvable, even though their continuous relaxations are still nonconvex. For the more general case, we employ a linearization technique and design a composite Lagrangian relaxation-implicit enumeration-cutting plane algorithm. Extensive computational experience is provided to test the efficacy of various algorithmic strategies and the effects of problem data on the computational effort of the proposed algorithm.
STATISTICAL CHOICES IN INFANT TEMPERAMENT RESEARCH

Temperamental characteristics can be conceptualized as either continuous dimensions or qualitative categories. The distinction concerns the underlying temperamental characteristics rather than the measured variables, which can usually be recorded as either continuous or categorical variables. A finite mixture model captures the categorical view, and we apply such a model here to two sets of longitudinal observations of infants and young children. A measure of predictive efficacy is described for comparing the mixture model with competing models, principally a linear regression analysis. The mixture model performs mildly better than the linear regression model with respect to this measure of fit to the data; however, the primary advantage of the mixture model relative to competing approaches, is that, because it matches our a priori theory, it can be easily used to address improvements and corrections to the theory, and to suggest extensions of the research.
Aggregation and fibrillization of the recombinant human prion protein huPrP90-231.

According to the “protein-only” hypothesis, the critical step in the pathogenesis of prion diseases is the conformational transition between the normal (PrPC) and pathological (PrPSc) isoforms of prion protein. To gain insight into the mechanism of this transition, we have characterized the biophysical properties of the recombinant protein corresponding to residues 90−231 of the human prion protein (huPrP90−231). Incubation of the protein under acidic conditions (pH 3.6−5) in the presence of 1 M guanidine-HCl resulted in a time-dependent transition from an α-helical conformation to a β-sheet structure and oligomerization of huPrP90−231 into large molecular weight aggregates. No stable monomeric β-sheet-rich folding intermediate of the protein could be detected in the present experiments. Kinetic analysis of the data indicates that the formation of β-sheet structure and protein oligomerization likely occur concomitantly. The β-sheet-rich oligomers were characterized by a markedly increased resistance to pr...
Large-amplitude electron density and Hα fluctuations in the sustained spheromak physics experiment

New types of toroidally rotating fluctuations (toroidal mode numbers n = 1 and n = 2) of line-integrated electron density and Hα emission, with frequencies ranging from 10 to 100 kHz, are observed in the sustained spheromak physics experiment (SSPX). The rotating directions of these fluctuations are the same as the direction determined by E×B, while the E and B directions are determined by the gun voltage and gun magnetic flux polarities, respectively. These results take advantage of one distinctive signature of spheromaks, i.e. it is possible to observe toroidal MHD activity during decay and sustainment at any toroidal angle. A theoretical constraint on line-integrated measurement is proposed and is found to be consistent with experimental observations. Fluctuation analysis in the time and frequency domains indicates that the observed density and Hα fluctuations correlate with magnetic modes. Observation of Hα fluctuations correlating with magnetic fluctuations indicates that, at least in some cases, MHD n = 1 modes are due to the so-called `dough-hook' current paths that connect the coaxial gun to the flux conserver, rather than internal kink instabilities. These results also show that electron density and Hα emission diagnostics complement other tools for spheromak mode study.
Optics of photonic quasicrystals

The optical characteristics and applications of the quasicrystal, a special form of aperiodic engineered structure, are explored in this Review article.
Vacuum-ultraviolet photoionization and mass spectrometric characterization of lignin monomers coniferyl and sinapyl alcohols.

The fragmentation mechanisms of monolignols under various energetic processes are studied with jet-cooled thermal desorption molecular beam (TDMB) mass spectrometry (MS), 25 keV Bi3+ secondary ion MS (SIMS), synchrotron vacuum-ultraviolet secondary neutral MS (VUV-SNMS) and theoretical methods. Experimental and calculated appearance energies of fragments observed in TDMB MS indicate that the coniferyl alcohol photoionization mass spectra contain the molecular parent and several dissociative photoionization products. Similar results obtained for sinapyl alcohol are also discussed briefly. Ionization energies of 7.60 eV ± 0.05 eV for coniferyl alcohol and <7.4 eV for both sinapyl and dihydrosinapyl alcohols are determined. The positive ion SIMS spectrum of coniferyl alcohol shares few characteristic peaks (m/z = 137 and 151) with the TDMB mass spectra, shows extensive fragmentation, and does not exhibit clear molecular parent signals. VUV-SNMS spectra, on the other hand, are dominated by the parent ion and ...
Brand Choice Modeling: Identifying a Brands Optimal Positioning

-Using a Fishbein-type approach, the authors developed a Brand Choice Model. Conceptually very simple, this model identifies each consumer's unique determinants of brand choice. By simulating changes in beliefs about a brand, it is possible to identify that brand's optimal positioning, i.e., a perceptual positioning that will maximize the brand's share of the market. As a result of having carefully selected attributes for inclusion in the model, the identified optimal positioning can be readily implemented.
New terpene hydrocarbons from the alligatoridae (crocodylia, reptilia).

The contents of the paracloacal gland secretions of the alligatorids Alligator mississippiensis, A. sinensis, Paleosuchus palpebrosus, and P. trigonatus were investigated. Novel acyclic hydrocarbon terpenes with a rare trisubstituted 2,4-diene system were identified in the secretions of A. sinensis, P. palpebrosus, and P. trigonatus. The structures of the monoterpene (2E,4E)-3,7-dimethyl-2,4-octadiene (9) and the sesquiterpene (2E,4E,7S)-3,7,11-trimethyl-2,4-dodecadiene (14) were proven by synthesis and gas chromatography on a chiral phase. Several other new terpenes (11, 16, 17, 18, 19, and 20) related to these components also were present in the secretions, as well as the known compounds myrcene (6), (E)-β-farnesene (4), (E)-β-springene (3), squalene (5), cembrene A (1), and 11,12-dihydrocembren-10-one (2).
Weathering in Antarctic H and CR chondrites: Quantitative analysis through Mössbauer spectroscopy

Abstract— Mossbauer spectroscopy is a very useful tool for identifying ferric iron weathering products in meteorites because of the capability to quantify the relative amounts of ferric iron in them. Mossbauer measurements were made of 33 Antarctic H chondrites (predominately H5) and two paired Antarctic CR chondrites. The primary goals of this study are to determine if Mossbauer spectroscopy can be used to determine which phases are weathering in Antarctic meteorites and if the relative amounts of ferric iron correlate with terrestrial age. Determining which minerals are weathering in ordinary chondrites appears very difficult due to variations in composition for different ordinary chondrites of the same meteorite class and possible problems in preparing homogeneous samples. The analysis of the two paired CR chondrites appears to indicate that metallic iron is predominately weathering to produce ferric iron for this class of meteorite. No correlation is seen between the relative amounts of ferric iron and terrestrial age for ordinary chondrites. One Antarctic H5 chondrite (ALHA77294) with a short 14C age of 135 ± 200 years from the dating of interior carbonate weathering products does have a relatively low amount of ferric iron, which is consistent with this meteorite being exposed on the surface for a relatively short time.
Robustness in neural computation: random graphs and sparsity

An attempt is made to mathematically codify the belief that fully interconnected neural networks continue to function efficiently in the presence of component damage. Component damage is introduced in a fully interconnected neural network model of n neurons by randomly deleting the links between neurons. An analysis of the outer-product algorithm for this random graph model of sparse interconnectivity yields the following result: If the probability of losing any given link between two neurons is 1- , then the outer-product algorithm can store on the order of pn/log pn/sup 2/ stable memories correcting a linear number of random errors. In particular, the average degree of the interconnectivity graph dictates the memory storage capability, and functional storage of memories as stable states is feasible abruptly when the average number of neural interconnections retained by a neuron exceeds the order of log n links (of a total of n possible links) with other neurons. >
Shedding of viral hemorrhagic septicemia virus (Genotype IVb) by experimentally infected muskellunge (Esox masquinongy)

Previous experimental infection demonstrated that juvenile muskellunge (Esox masquinongy) can survive experimental infection of viral hemorrhagic septicemia virus, Genotype IVb (VHSV IVb) at a low concentration of exposure. Herein we report that survivors of experimental infection with VHSV IVb shed the virus into the surrounding environment for an extended period of time. When muskellunge were exposed to VHSV IVb by immersion at a concentration of 1,400 plaque forming units (PFU)/ml, VHSV IVb was detected in the water of surviving fish for up to 15 weeks postexposure (p.e.) with the highest levels of shedding occurring between weeks 1 and 5 p.e. We estimated that each juvenile muskellunge can shed upwards of 1.36×105 PFU/fish/h after initial exposure signifying the uptake and amplification of VHSV to several orders of magnitude above the original exposure concentration. Muskellunge surviving low concentration exposure were re-infected with VHSV IVb by immersion at week 22 p.e. at concentrations ranging from 0 to 106 PFU/ml. Viral shedding was detected in all re-exposed fish, including mock rechallenged controls up to 15 consecutive weeks. Rates of viral shedding were substantially higher following rechallenge in the first 5 weeks. The highest rate of viral shedding was approximately 4.6×106 PFU/fish/h and shedding did not necessarily correspond to the re-exposure VHSV concentration. The results of this study shed new light into the dynamics of VHSV IVb shedding in a highly susceptible host and provide useful insights to fishery managers to design effective control strategies to this deadly virus.
An integrated technique for the analysis of traffic lights and signs supported by the dual cable system

Abstract Due to failures of cable-supported traffic lights and signs under wind loading during Hurricane Andrew, a need for a comprehensive analysis method was identified. The computer program ATLAS satisfies this need and utilizes an integrated technique that consists of the extended force density method and the nonlinear direct stiffness method for large displacements. The integration of the two methods is essential for the analysis of such systems because of the numerical instabilities developed when using the direct stiffness method alone. The resulting analysis procedure proved to be stable. This paper provides a description as to how the two methods were integrated and implemented in ATLAS.
Knowledge Management: intellectual capital and social capital. An approach for Latin America

Considere la gestion des connaissances en tant que nouvelle logique et pratique organisationnelle emergente, basee sur les nouvelles technologies de l'information et de la communication. Presente une proposition de reconfiguration de la theorie en bibliotheconomie et sciences de l'information, et la situation pratique dans les pays d'Amerique Latine afin de promouvoir une approche systematique et integrale de la gestion des connaissances. Il faut developper et utiliser le capital intellectuel afin de promouvoir le developpement social. Propose un modele integral pour l'organisation de l'information et des connaissances, defini comme l'Architecture organisationnelle de l'information, un environnement d'apprentissage adapte aux besoins individuels, d'equipes et d'organisations. Introduit le concept du capital social en tant qu'aide a la conception de politiques, de programmes et d'actions d'information, et souligne son caractere strategique en tant que facteur du developpement social, economique, politique et culturel dans la region d'Amerique Latine. En conclusion : la conception organisationnelle basee sur la gestion des connaissances forme un outil pour le developpement humain et social au sein d'organisations et de pays. Les professionnels de l'information peuvent jouer un role dans la transformation des informations en connaissances, en fournissant du support aux processus decisionnels innovateurs, creatifs et productifs.
Allee effects and population regulation: a test for biotic resistance against an invasive leafroller by resident parasitoids

Resident natural enemies can impact invasive species by causing Allee effects, leading to a reduction in establishment success of small founder populations, or by regulating or merely suppressing the abundance of established populations. Epiphyas postvittana, the Light Brown Apple Moth, an invasive leafroller in California, has been found to be attacked by a large assemblage of resident parasitoids that cause relatively high rates of parasitism. Over a 4-year period, we measured the abundance and per capita growth rates of four E. postvittana populations in California and determined parasitism rates. We found that at two of the sites, parasitism caused a component Allee effect, a reduction in individual survivorship at lower E. postvittana population densities, although it did not translate into a demographic Allee effect, an impact on per capita population growth rates at low densities. Instead, E. postvittana populations at all four sites exhibited strong compensatory density feedback throughout the entire range of densities observed at each site. As we found no evidence for a negative relationship between per capita population growth rates and parasitism rates, we concluded that resident parasitoids were unable to regulate E. postvittana populations in California. Despite a lack of evidence for regulation or a demographic Allee effect, the impact of resident parasitoids on E. postvittana populations is substantial and demonstrates significant biotic resistance against this new invader.
Facile amine formation by intermolecular catalytic amidation of carbon-hydrogen bonds.

A simple copper-based catalytic system has been developed for the carbon−hydrogen amidation reaction. The copper−homoscorpionate complex TpBr3Cu(NCMe) catalyzes the transfer of the nitrene unit NTs (Ts = p-toluenesulfonyl) and its subsequent insertion into the sp3 C−H bonds of alkyl aromatic and cyclic ethers or the sp2 C−H bonds of benzene using PhINTs as the nitrene source, affording the corresponding trisubstitued NR1HTs amines in moderate to high yields. The use of the environmentally friendly chloramine-T has also proven effective, with the advantage that sodium chloride is formed as the only byproduct. A tandem, one-pot consecutive nitrene−carbene insertion system has been developed to yield amino acid derivatives.
Prospects for utilization of air liquefaction and enrichment system (ALES) propulsion in fully reusable launch vehicles

A concept is shown for a fully reusable, earth to orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high speed acceleration, both using LH2 fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90 percent pure LOX that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to Mach 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. The paper shows an approach and the corresponding technology needs for using ALES propulsion in a SSTO vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, is critical to meet the structure weight objective for SSTO. Configurations that utilize 'waverider' aerodynamics show great promise to reduce the vehicle weight.
Hypertrophic cardiomyopathy as a cause of massive cardiomegaly (>1,000 g)

Abstract The normal adult human heart in women weighs ≤350 g and in men it weighs ≤400 g. The occurrence of heart weights in humans >1,000 g is exceedingly rare. During the past 30 years, approximately 10,000 human adult hearts with various types of cardiovascular diseases have been examined in this laboratory. Of that number, 30 weighed >1,000 g. 1 The most common (15 patients) cause of the massive cardiomegaly was aortic regurgitation with or without other volume lesions, such as mitral regurgitation or ventricular septal defect. Pressure lesions as the cause of massive cardiomegaly were far less common: 4 patients had aortic valve stenosis, but all also had associated aortic regurgitation or mitral regurgitation. Cardiomyopathy is a rare cause of massive cardiomegaly. Of >200 patients with idiopathic dilated cardiomyopathy studied at necropsy in this laboratory, none had hearts weighing > 1,000 g. Of 70 patients with cardiac amyloidosis extensive enough to cause cardiac dysfunction, none had massive cardiomegaly. During the past 30 years, we have studied at necropsy 220 patients with hypertrophic cardiomyopathy (HC) and 200 of them were >20 years of age. Of this latter number, 8 had hearts weighing >1,000 g. This report summarizes findings in these 8 patients and also describes the heart weights in 207 other patients with HC studied by us at necropsy.
Thermal decomposition of mixed calcium carboxylate salts: effects of lime on ketone yield.

Abstract The MixAlco™ process ferments lignocellulosic biomass to carboxylate salts that are concentrated by evaporation and chemically converted to a wide variety of chemicals and fuels. To avoid losses during evaporation, lime is used to convert residual carboxylic acids to their corresponding salts. If excess lime is present, it could adversely affect downstream processing. The dry carboxylate salts are thermally decomposed to produce ketones as primary products, with by-products of tars and heavy oils, hydrocarbons, synthesis gas, and other oxygenates. This study investigates the effects of lime on the product distribution during thermal decomposition of mixed calcium carboxylate salts. To predict product distribution, a random-pairing model and a Gibbs free energy minimization model were applied and assessed. Mixtures of reagent-grade calcium carboxylate salts – as well as calcium carboxylate salts from fermentation broth – were thermally decomposed at 450 °C. Low lime-to-salt ratios (g Ca(OH) 2 /g salt) of 0.00134 and less had a negligible effect on ketone yield. Salts with higher lime-to-salt ratios of 0.00461, 0.0190, and 0.272 showed 3.5, 4.6, and 9.4% loss in ketone yield, respectively. These losses were caused primarily by increases in tars and heavy oils; however, a three-fold increase in hydrocarbon production occurred as well.
Significance of Family Risk Factors in Development of Childhood Animal Cruelty in Adolescent Boys with Conduct Problems

The literature suggests that physical child abuse, sexual child abuse, paternal alcoholism, paternal unavailability, and domestic violence may be significant in development of childhood animal cruelty. Two groups of early- to late adolescent boys (CTA and N-CTA) in residential treatment for conduct disorder were compared in the current study on histories of these family risk factors. The adolescents in Group 1 were comprised of boys who had conduct problems with documented histories of animal cruelty (n = 50; CTA). Group 2 consisted of adolescent boys (n = 50; N-CTA) with conduct problems, but without documented histories of animal cruelty. Results showed that children in the CTA group had significantly greater histories of physical and/or sexual child abuse and domestic violence in comparison to children in the N-CTA group. These results suggest that physical and/or sexual abuse to a child, and exposure to domestic violence, may be significant in the development of childhood animal cruelty.
Modified Blalock shunts utilizing pericardial tube grafts

Abstract In the last decade, 14 patients underwent an aorticopulmonary shunt for cyanotic heart disease, at which time the subclavian artery was either deemed too small or too short to function satisfactorily as a Blalock shunt. In each case a rectangular piece of pericardium was excised, rolled into a tube, and sutured down one edge to create a tube graft. One end of the fraft was sutured to the stump of the subclavian artery near its takeoff and the other end was sutured end-to-side to the corresponding pulmonary artery. During the same period, 5 children had azygos vein grafts and 2 had Teflon grafts inserted to create a modifled Blalock shunt. This article will discuss the indications, techniques, and long term results of aorticopulmonary shunts of all types, and more specifically the complications and long term results in patients where these grafts were used.
Flame zone studies III—Techniques for the determination of composition profiles of flame fronts

Abstract The understanding of combustion processes can be greatly increased by a determination of the composition of a flame front as a function of position. This paper describes techniques for making such measurements. Aerodynamic and temperature profiles are available from other studies. The information can be used to determine reaction rates and to deduce reaction mechanisms and activation energies. The information available through this study and other experimental studies of flame fronts is equivalent to that obtained in the most extensive conventional reaction kinetic studies, and offers a fertile field for the study of many very fast reactions. Since these techniques are new, detailed consideration is given to the question of reliability and interpretation of the results. Critical experiments are cited to show the existence of a single set of composition profiles that uniquely describe a laminar flame front and to establish that they can be reproducibly and accurately determined by these techniques. It is concluded that composition profiles can be measured with useful precision.
A Comparative Study of Uncertainty Propagation Methods for Black-Box Type Functions

It is an important step in deign under uncertainty to select an appropriate uncertainty propagation (UP) method considering the characteristics of the engineering systems at hand, the required level of UP associated with the probabilistic design scenario, and the required accuracy and efficiency levels. Many uncertainty propagation methods have been developed in various fields, however, there is a lack of good understanding of their relative merits. In this paper, a comparative study on the performances of several UP methods, including a few recent methods that have received growing attention, is performed. The full factorial numerical integration (FFNI), the univariate dimension reduction method (UDR), and the polynomial chaos expansion (PCE) are implemented and applied to several test problems with different settings of the performance nonlinearity, distribution types of input random variables, and the magnitude of input uncertainty. The performances of those methods are compared in moment estimation, tail probability calculation, and the probability density function (PDF) construction. It is found that the FFNI with the moment matching quadrature rule shows good accuracy but the computational cost becomes prohibitive as the number of input random variables increases. The accuracy and efficiency of the UDR method for moment estimations appear to be superior when there is no significant interaction effect in the performance function. Both FFNI and UDR are very robust against the non-normality of input variables. The PCE is implemented in combination with FFNI for coefficients estimation. The PCE method is shown to be a useful approach when a complete PDF description is desired. Inverse Rosenblatt transformation is used to treat non-normal inputs of PCE, however, it is shown that the transformation may result in the degradation of accuracy of PCE. It is also shown that in black-box type of system the performance and convergence of PCE highly depend on the method adopted to estimate its coefficients.© 2007 ASME
Growth factors regulate transin gene expression by c-fos-dependent and c-fos-independent pathways

The rapid induction of the proto-oncogene c-fos by growth factors and other bioactive agents, and the recent evidence that the c-fos protein (Fos) is associated with transcriptional complexes, suggests that Fos may represent an integral part of an intracellular messenger pathway that triggers changes in gene expression and ultimately phenotypic alterations. This report examines the role of c-fos in growth factor stimulation of transin, a matrix-degrading secreted metalloproteinase. Platelet-derived growth factor (PDGF) stimulation of transin RNA was blocked by a selective reduction in Fos synthesis with antisense c-fos mRNA, whereas epidermal growth factor (EGF) stimulation of transin occurred despite an equivalent inhibition of Fos levels. The stimulatory effect of both PDGF and EGF on transin transcription involved factors recognizing the sequence TGAGTCA, which is found in the transin promoter and is reported to be a binding site for the transcriptional factor Jun/AP-1 and for associated Fos and Fos-related complexes. Thus both Fos-dependent and Fos-independent pathways exist for growth factor regulation of gene expression, and both effects may be mediated through the same cis-acting transcription element.
Single-base deletion induced by benzo[a]pyrene diol epoxide at the adenine phosphoribosyltransferase locus in human fibrosarcoma cell lines

Benzo[a]pyrene diol epoxide (BPDE), a metabolic product of benzo[a]pyrene, is one of the most widely distributed environmental carcinogens. In this study, we demonstrate that BPDE produces a dose-dependent increase in the frequency of APRT gene reversion in the APRT-deficient cell line, HTD114, which contains single nucleotide insertions at different positions in each APRT allele. The highest reversion frequency observed after BPDE exposure was 3.3 +/- 0.9 x 10(-5), at least 10(3)-fold greater than the spontaneous frequency. Reversion of either mutant allele was observed to be a consequence of a frame-restoring loss of a single nucleotide. A similar frequency of BPDE-induced reversion at APRT also was observed in a cell line containing only one type of the mutant alleles of HTD114, thus eliminating the possibility that gene conversion plays a major role in APRT gene reversion in HTD114 cells. Therefore, the data demonstrate that BPDE can function as an effective frameshift mutagen in human cells.
Development Of A Flash X-Ray Scanner For Stereoradiography And CT

We are developing a flash x-ray scanner for stereoradiography and CT which will be able to produce a stereoradiograph in 30 to 70 ns and a complete CT scan in one microsecond. This type of imaging device will be valuable in studying high speed processes, high acceleration, and traumatic events. We have built a two channel flash x-ray system capable of producing stereo radiographs with stereo angles of from 15 to 165 degrees. The dynamic and static Miff 's for the flash x-ray system were measured and compared with similar MIT's measured for a conventional medical x-ray system. We have written and tested a stereo reconstruction algorithm to determine three dimensional space points from corresponding points in the two stereo images. To demonstrate the ability of the system to image traumatic events, a radiograph was obtained of a bone undergoing a fracture. The effects of accelerations of up to 600 g were examined on radiographs taken of human kidney tissue samples in a rapidly rotating centrifuge. Feasibility studies of CT reconstruction have been performed by making simulated Cr images of various phantoms for larger flash x-ray systems of from 8 to 29 flash x-ray tubes.
SPECTROSCOPIC INVESTIGATION OF REDUCED PROTOCATECHUATE 3,4-DIOXYGENASE : CHARGE-INDUCED ALTERATIONS IN THE ACTIVE SITE IRON COORDINATION ENVIRONMENT

Chemical reduction of the mononuclear ferric active site in the bacterial intradiol cleaving catecholic dioxygenase protocatechuate 3,4-dioxygenase (3,4-PCD, Brevibacterium fuscum) produces a high-spin ferrous center. We have applied circular dichroism (CD), magnetic circular dichroism (MCD), variable-temperature-variable-field (VTVH) MCD, X-ray absorption (XAS) pre-edge, and extended X-ray absorption fine structure (EXAFS) spectroscopies to investigate the geometric and electronic structure of the reduced iron center. Excited-state ligand field CD and MCD data indicate that the site is six-coordinate where the 5Eg excited-state splitting is 2033 cm-1. VTVH MCD analysis of the ground state indicates that the site has negative zero-field splitting with a small rhombic splitting of the lowest doublet (δ = 1.6 ± 0.3 cm-1). XAS pre-edge analysis also indicates a six-coordinate site while EXAFS analysis provides accurate bond lengths. Since previous spectroscopic analysis and the crystal structure of oxidized ...
Measurement of relative output factors for the 8 and 4 mm collimators of Leksell Gamma Knife Perfexion by film dosimetry.

Three types of films, Kodak EDR2, Gafchromic EBT, and Gafchromic MD-V2-55, were used to measure relative output factors of 4 and 8 mm collimators of the Leksell Gamma Knife Perfexion. The optical density to dose calibration curve for each of the film types was obtained by exposing the films to a range of known doses. Ten data points were acquired for each of the calibration curves in the dose ranges from 0 to 4 Gy, 0 to 8 Gy, and 0 to 80 Gy for Kodak EDR2, Gafchromic EBT, and Gafchromic MD-V2-55 films, respectively. For the measurement of relative output factors, five films of each film type were exposed to a known dose. All films were scanned using EPSON EXPRESSION 10000 XL scanner with 200 dpi resolution in 16 bit gray scale for EDR2 film and 48 bit color scale for Gafchromic films. The scanned images were imported in the red channel for both Gafchromic films. The background corrections from an unexposed film were applied to all films. The output factors obtained from film measurements were in a close agreement both with the Monte Carlo calculated values of 0.924 and 0.805 for 8 and 4 mm collimators, respectively. These valuesmore » are provided by the vendor and used as default values in the vendor's treatment planning system. The largest differences were noted for the Kodak EDR 2 films (-2.1% and -4.5% for 8 and 4 mm collimators, respectively). The best agreement observed was for EBT Gafchromic film (-0.8% and +0.6% differences for 8 and 4 mm collimators, respectively). Based on the present values, no changes in the default relative output factor values were made in the treatment planning system.« less
Efficacy of a Computer-Assisted Voice Treatment Protocol

A voice treatment protocol using a computer-assisted biofeedback device for hyper-functional voice disorders was evaluated in two adults. The specific components of the treatment were assessed using a single-subject interaction design. The overall contribution of relaxation to the treatment package was also evaluated. The treatment package was effective in improving the voice, as demonstrated by elimination of the vocal nodules, subjective data (ratings of the voice by subjects and naive listeners), and objective data (changes in fundamental frequency, maximum phonation time, perturbation factor percentages, breathing errors, and slow rise in volume). It appeared that the effect of the combined relaxation and traditional voice protocol was cumulative in nature, and addition of therelaxation component was no more effective than the protocol without the relaxation component.
Hybrid restriction enzymes: zinc finger fusions to Fok I cleavage domain

A long-term goal in the field of restriction-modification enzymes has been to generate restriction endonucleases with novel sequence specificities by mutating or engineering existing enzymes. This will avoid the increasingly arduous task of extensive screening of bacteria and other microorganisms for new enzymes. Here, we report the deliberate creation of novel site-specific endonucleases by linking two different zinc finger proteins to the cleavage domain of Fok I endonuclease. Both fusion proteins are active and under optimal conditions cleave DNA in a sequence-specific manner. Thus, the modular structure of Fok I endonuclease and the zinc finger motifs makes it possible to create "artificial" nucleases that will cut DNA near a predetermined site. This opens the way to generate many new enzymes with tailor-made sequence specificities desirable for various applications.
Start-up from noise and high-gain regime of the free electron laser: A hamiltonian formulation

Abstract By using a hamiltonian formulation we develop a consistent set of equations for the motion of electrons in the field produced by radiation and the wiggler. We treat the coupled electron-field equations in the linear and high-gain regimes, both analytically and numerically, and investigate the start-up of the free electron laser from noise. Comparison with previous theories shows that the differences in lethargy times and gains can be as large as 30%.
Heat transfer and fluid flow in floating-zone crystal growth with a mostly covered melt surface

Computer simulation was conducted to study a modified floating-zone crystal growth process, in which the melt surface is mostly covered with a heated ring. The growth of 6-mm diameter single crystals of NaNO3 was considered, and the effects of the following parameters were studied: (1) temperature of the ring, (2) growth rate, (3) surface tension-temperature coefficient of the melt, (4) thermal expansion coefficient of the melt, and (5) gravity. It was demonstrated that thermocapillary convection in the melt zone is reduced significantly in this modified process. The model was checked against the measured lengths of the meniscus near the growth front and axial temperature distribution in a growing crystal, and the agreement was good.
Bamboo: a data-centric, object-oriented approach to many-core software

Traditional data-oriented programming languages such as dataflow languages and stream languages provide a natural abstraction for parallel programming. In these languages, a developer focuses on the flow of data through the computation and these systems free the developer from the complexities of low-level, thread-oriented concurrency primitives. This simplification comes at a cost --- traditional data-oriented approaches restrict the mutation of state and, in practice, the types of data structures a program can effectively use. Bamboo borrows from work in typestate and software transactions to relax the traditional restrictions of data-oriented programming models to support mutation of arbitrary data structures.We have implemented a compiler for Bamboo which generates code for the TILEPro64 many-core processor. We have evaluated this implementation on six benchmarks: Tracking, a feature tracking algorithm from computer vision; KMeans, a K-means clustering algorithm; MonteCarlo, a Monte Carlo simulation; FilterBank, a multi-channel filter bank; Fractal, a Mandelbrot set computation; and Series, a Fourier series computation. We found that our compiler generated implementations that obtained speedups ranging from 26.2x to 61.6x when executed on 62 cores.
La importancia del acuerdo entre codificadores para el análisis de contenido

Normal 0 21 false false false MicrosoftInternetExplorer4 Content analysis is a widely utilized technique by researchers on mass media. Generally, researchers in quantitative content analysis rely on several coders to enter the data. A key question they face is whether it is possible to assure that the coders’ decisions are consistent across the analysis. It is expected for different people to have different interpretations of the texts, which threatens the reliability of the obtained results and the study’s conclusions. In order to avoid this threat, researchers must evaluate and report intercoder agreement. In this essay, arguments for this practice are presented and a reflection about its use on an empirical case study is offered. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}
Renal Ultrasound Changes After Pyeloplasty in Children With Ureteropelvic Junction Obstruction: Long-term Outcome in 47 Renal Units

AbstractPurpose: We evaluated the use of renal ultrasound for monitoring pyelocaliectasis after pyeloplasty in children.Materials and Methods: Changes in pyelocaliceal dilatation following pyeloplasty were assessed by serial ultrasound. Of 104 children 0 to 12 years old who underwent pyeloplasty between 1982 and 1992, 44 (47 renal units) were monitored with serial ultrasound for at least 2 years (range 2 to 9, mean 3.8). Patient ages at pyeloplasty were 0 to 3 months (17), 4 to 12 months (8), 1 to 6 years (13) and 7 to 12 years (6). Preoperative and postoperative ultrasound was reviewed by a single pediatric radiologist blinded to the date of surgery. The degree of pyelocaliectasis was graded as 0 to 4 according to the classification of the Society for Fetal Urology.Results: Preoperative ultrasound revealed grade 4 pyelocaliectasis in 26 kidneys (55 percent) and grade 3 disease in 21 (45 percent). Grade was the same or worse 1 month after pyeloplasty in the majority of kidneys (92 percent) studied at this...
Evaluation of Urine Aquaporin-1 and Perilipin-2 Concentrations as Biomarkers to Screen for Renal Cell Carcinoma: A Prospective Cohort Study

Importance Historically, early detection of small asymptomatic kidney tumors presages better patient outcome. Screening for asymptomatic renal tumors by abdominal imaging is not cost-effective and cannot reliably distinguish benign from malignant tumors. Objective This investigation evaluated the clinical utility, sensitivity, and specificity of urine aquaporin-1 (AQP1) and perilipin-2 (PLIN2) concentrations as unique, noninvasive biomarkers to diagnose malignant clear cell or papillary renal cell carcinoma (RCC) in a screening paradigm. Design, Setting, and Participants From February through December 2012, urine samples were obtained from 720 patients undergoing routine abdominal computed tomography (CT) (screening population), 80 healthy controls, and 19 patients with pathologically confirmed RCC. Main Outcomes and Measures Urine AQP1 and PLIN2 concentrations were measured by sensitive and specific enzyme-linked immunosorbent assay and Western blot procedures, respectively, in all groups. In the otherwise asymptomatic screening population, the absence or presence of a renal mass and RCC were verified by abdominal CT and by postnephrectomy pathologic diagnosis, respectively. Results Urine AQP1 and PLIN2 concentrations were significantly higher (all P Conclusions and Relevance These results demonstrate the clinical utility, specificity, and sensitivity of urine AQP1 and PLIN2 to diagnose RCC. These tumor-specific proteins have high clinical validity and substantial potential as specific diagnostic and screening biomarkers for clear cell or papillary RCC and in the differential diagnosis of imaged renal masses.
Estradiol regulates responsiveness of the dorsal premammillary nucleus of the hypothalamus and affects fear‐ and anxiety‐like behaviors in female rats

Research suggests a causal link between estrogens and mood. Here, we began by examining the effects of estradiol (E2 ) on rat innate and conditioned defensive behaviors in response to cat odor. Second, we utilized whole-cell patch clamp electrophysiological techniques to assess noradrenergic effects on neurons within the dorsal premammillary nucleus of the hypothalamus (PMd), a nucleus implicated in fear reactivity, and their regulation by E2 . Our results show that E2 increased general arousal and modified innate defensive reactivity to cat odor. When ovariectomized females treated with E2 as opposed to oil were exposed to cat odor, they showed elevations in risk assessment and reductions in freezing, indicating a shift from passive to active coping. In addition, animals previously exposed to cat odor showed clear cue + context conditioning 24 h later. However, although E2 persisted in its effects on general arousal in the conditioning task, its effects on fear disappeared. In the patch clamp experiments noradrenergic compounds that typically induce fear clearly excited PMd neurons, producing depolarizations and action potentials. E2 treatment shifted some excitatory effects of noradrenergic agonists to inhibitory, possibly by differentially affecting α- and β-adrenoreceptors. In summary, our results implicate E2 in general arousal and fear reactivity, and suggest these may be governed by changes in noradrenergic responsivity in the PMd. These effects of E2 may have ethological relevance, serving to promote mate seeking even in contexts of ambiguous threat and shed light on the involvement of estrogen in mood and its associated disorders.
Welfare and Market Impacts of Food Safety Measures in China: Results from Urban Consumers' Valuation of Product Attributes

This study provides an economics assessment of various food safety measures in China. A choice experiment approach is used to elicit Chinese consumer preferences for various food safety attributes using data from a 2008 urban consumer survey. An alternative welfare calculation is used to model aggregate market impacts of select food safety measures. Our results show that the largest welfare gains are found in the current government-run certification program. The implementation of a third-party certification system, a traceability network and a product label would generate significant value and would help reduce current system inefficiencies in China. This study builds on previous research and provides an alternative approach for calculating consumer valuation of safety and quality attributes that can be used to estimate aggregate economic and welfare impacts.
Kinetics of the low pH decolorization of azurin

Reaction rates were measured for the low pH-induced Cu ligand modification of azurins from Pseudomonas aeruginosa and Alcaligenes faecalis. Loss of the intense absorption band at 625 nm obeyed a rate law: where Az is the concentration of azurin in its native oxidized form possessing the 625 nm band. For Pseudomonas aeruginosa at 25°C, n = 1 and k = 4.0 × 10-2 sec-1 M-1 in citrate buffer but 1.2 × 10-2 sec-1 M-1 in phosphate buffer. For Alcaligenes faecalis, n = 3 and k = 1.5 × 104 sec-1 M-3 in citrate and 2.6 × 103 sec-1 M-3 in phosphate. In equilibrium experiments on Alcaligenes faecalis azurin in citrate buffer, the pH-dependent change to the low pH form exhibited an apparent transition pK of 3.1. The form of the rate law implies a mechanistic scheme that contains fast equilibrium protonation steps prior to a rate limiting ligand rearrangement.
Gestational trophoblastic disease: another cause of nausea and vomiting in pregnancy.

To the Editor: We read with interest the Residents’ Clinic by Ramsey and Ramin describing the case of a 34-year-old pregnant woman with thyrotoxic vomiting, an uncommon but important and underrecognized cause of persistent vomiting in both pregnant and nonpregnant states. Thyroid function tests demonstrated suppressed thyroid-stimulating hormone (TSH) and elevated free thyroxine (T 4 ). Several diagnoses were discussed, including Graves disease, hyperemesis gravidarum, Hashimoto thyroiditis, toxic multinodular goiter, and triiodothyronine thyrotoxicosis. However, gestational trophoblastic disease (GTD), a recognized cause of hyperthyroidism and hyperemesis during pregnancy, was not mentioned. The 2 forms of GTD, hydatidiform mole and choriocarcinoma, complicate 1 in 1000 and 1 in 50,000 pregnancies, respectively. In both conditions, human chorionic hormone (hCG) is produced in high concentrations. A glycoprotein hormone, hCG shares a common α subunit with TSH but has a different β subunit. At high concentrations, hCG can stimulate the TSH receptor to induce hyperthyroidism. Thyroid function tests demonstrate suppressed TSH and elevated free T 4 identical to the findings in Graves disease, but thyroid-stimulating immunoglobulin or TSHreceptor antibody levels are negative. It is postulated that hCG plays a role in the pathogenesis of hyperemesis gravidarum, although hyperthyroidism itself can also be a potent stimulus for nausea. Gestational trophoblastic disease should be included in the differential diagnosis of patients with hyperemesis gravidarum or with thyrotoxicosis during pregnancy.
A Review of “Writing the Love of Boys: Origins of Bishōnen Culture in Modernist Japanese Literature”

Many things changed with Japan's transition to modernity, but surely one of the most stunning and consequential of the Meiji transformations was the shift in perceptions of male same-sex sexuality ...