cssi/SciSciGPT-SciSciNet huggingface dataset:
Modulation of rat brain cytosolic phosphatidate phosphohydrolase: effect of cationic amphiphilic drugs and divalent cations

The effects of three cationic amphiphilic drugs on rat brain cytosolic phosphatidate phosphohydrolase and their mechanisms of action were studied utilizing membrane-bound, emulsified, and emulsified sonicated phosphatidate as substrates. With the membrane-bound substrate, chlorpromazine, desmethylimipramine, and propranolol inhibited the activity in a dose-dependent fashion with an IC50 of 30-50 microM. In the presence of the emulsified substrate, chlorpromazine was a more potent inhibitor than desmethylimipramine or propranolol but 200 microM was needed for 50% inhibition of activity. Addition of heat-inactivated microsomes to the emulsified substrate, to simulate the conditions with the membrane-bound substrate, did not alter this value. Both Mg2+ and Ca2+ stimulated the enzyme activity but only Ca2+ counteracted the effect of chlorpromazine. Kinetic studies indicate that chlorpromazine acts as a noncompetitive inhibitor of the enzyme. Emulsified sonicated phosphatidate was a good substrate at low (less than 10 microM) concentrations. It was a poor substrate at 1 mM, but at this concentration chlorpromazine stimulated the activity instead of inhibiting. This drug altered the integrity of phosphatidate vesicle membranes as visualized by electron microscopy. The different results obtained with the three types of substrate indicate the importance of the configuration of phosphatidate for the expression of enzyme activity and for its susceptibility to the action of cationic amphiphilic drugs.
Buried mine detection in airborne imagery using co-occurrence texture features

In recent years, airborne minefield detection has increasingly been explored due to its capability for low-risk standoff detection and quick turnaround time. Significant research efforts have focused on the detection of surface mines and few techniques have been proposed specifically for buried mine detection. The detection performance of current detectors, like RX, for buried mines is not satisfactory. In this paper, we explore a methodology for buried mine detection in multi-spectral imagery, based on texture information of the target signature. A systematic approach for the selection of co-occurrence texture features is presented. Bhattacharya coefficient is used for the initial selection of discriminatory texture features, followed by principal feature analysis of the selected features, to identify minimum number of features with mutually uncorrelated information. Finally, a detection method based on unsupervised clustering of mine features in the reduced feature space, is employed for generating the test statistic for detection. Because the proposed method is based on co-occurrence matrix features, it is largely invariant to illumination changes in the images. Results for the proposed method are presented, which show improvement in the detection performance vis-a-vis multi-band RX anomaly detection, and validate the proposed clustering-based detection method.
Conductivity and Hall effect measurements in doped polyacetylene

Abstract Conductivity and Hall effect measurements are reported for polyacetylene films heavily doped with AsF5. The Hall coefficient is anomalously small, however, it is p-type and relatively temperature insensitive in the range 4–300 K indicative of metallic conduction. The effects of film degration by heating and air exposure are also investigated.
Effects of carotenoids on aflatoxin B1-induced mutagenesis in S. typhimurium TA 100 and TA 98.

Abstract The effects of β‐carotene, canthaxanthin, and extracts of tomato paste (containing lycopene) and orange juice (containing cryptoxanthin) on aflatoxin B1 (AFB1)‐induced mutagenesis in S. typhimurium TA 100 and TA 98 were investigated. Inhibition of mutagenesis was studied during and following completion of AFB, metabolism (i.e., after the addition of menadione), thereby permitting separate examination of the metabolic activation and phenotypic expression phases. Each experimental carotenoid, except lycopene, inhibited AFB1‐induced mutagenesis in both tester strains. Cryptoxanthin was the most potent inhibitor, being at least an order of magnitude more potent than the other carotenoids. Inhibition by β‐carotene and canthaxanthin was more prominent during the activation phase, whereas cryptoxanthin was more effective during the subsequent phenotypic expression phase. These inhibitory effects were not dependent on conversion to retinol.
Impact of Physics Representations in the HWRFX on Simulated Hurricane Structure and Pressure–Wind Relationships

AbstractA series of idealized experiments with the NOAA Experimental Hurricane Weather Research and Forecasting Model (HWRFX) are performed to examine the sensitivity of idealized tropical cyclone (TC) intensification to various parameterization schemes of the boundary layer (BL), subgrid convection, cloud microphysics, and radiation. Results from all the experiments are compared in terms of the maximum surface 10-m wind (VMAX) and minimum sea level pressure (PMIN)—operational metrics of TC intensity—as well as the azimuthally averaged temporal and spatial structure of the tangential wind and its material acceleration.The conventional metrics of TC intensity (VMAX and PMIN) are found to be insufficient to reveal the sensitivity of the simulated TC to variations in model physics. Comparisons of the sensitivity runs indicate that (i) different boundary layer physics parameterization schemes for vertical subgrid turbulence mixing lead to differences not only in the intensity evolution in terms of VMAX and PM...
Characterization of Ultrafine Particles and Other Traffic Related Pollutants Near Roadways in Beijing

The mass concentrations of PM2.5 (particles with aerodynamic diameter < 2.5 um), number concentration of ultrafine particles (UFP, particles with aerodynamic diameter < 100 nm), concentrations of carbon dioxide (CO2), as well as mass concentrations of black carbon (BC, results from incomplete combustion of fossil fuels and biomass, usually consists of several linked carbon atoms, commonly referred to as soot ) were measured near the Peking University (PKU) campus in Beijing from December 10th to December 23rd, 2011. Correlation between UFP number concentrations and PM2.5 mass concentrations, as well as PM2.5 mass concentrations and BC mass concentrations were determined while taking into consideration the local meteorological conditions and traffic densities determined from recorded video footage. Traffic emissions were calculated using ultrafine particle number concentration (PNC) and CO2 concentrations. The PM2.5 mass concentration, PNC, BC mass concentration as well as calculated traffic emission data were compared with existing data for the Los Angeles metropolitan region. The differences and similarities between the two data sets were compared and discussed.No correlation was found between PNC and PM2.5 mass concentrations. However, a high correlation between BC and PM2.5 mass concentrations was found. Also, correlations were identified between local meteorological conditions such as wind direction and PNC, PM2.5, and BC mass concentrations near roadways, especially when the site was downwind of local traffic. No correlation was found between wind speed and PNC, although strong correlations were found between wind speed and PM2.5, as well as BC mass concentrations. Days where both PM2.5 mass concentrations and PNC were higher at the control site were observed to be wind direction dependent, indicating the detection of regional emission sources. A strong correlation between PM2.5 mass concentrations and local visibility was also demonstrated. In terms of traffic, total traffic had almost no correlation with PNC. However, total diesel traffic was found to have some correlation to PNC, with higher diesel vehicle volume correlating to higher PNC. Finally, from the comparison between Los Angeles and Beijing data sets, Beijing tends to have higher emission factors, as well as near roadway PNC and PM2.5 mass concentrations, after controlling for wind direction.Data generated from this study could be used to model near roadway exposures to PM2.5 as well as UFP, especially from an occupational exposure standpoint for roadside workers such as food stand workers, traffic directing personnel, among others.
The scent of genetic compatibility: Sexual selection and the major histocompatibility complex

Individuals in some species prefer mates carrying dissimilar genes at the major histocompatibility complex (MHC), which may function to increase the MHC or overall heterozygosity of progeny. Here I review the evidence for MHC-dependent mating preferences from recent studies, including studies on the underlying olfactory mechanisms and evolutionary functions. Many studies indicate that MHC genes influence odour, and some work is beginning to examine the potential role of MHC-linked olfactory receptor genes in mating preferences. MHC-dependent mating preference increases the MHC-heterozygosity of progeny, which is suspected to confer resistance to infectious diseases. In humans, heterozygosity at MHC loci is associated with increased resistance to hepatitis and HIV infections, but experimental evidence for the heterozygote advantage hypothesis has been lacking. Here I re-analyse data from previously published experimental infection studies with mice. I show that although overdominance is rare, resistance is often dominant, suggesting that heterozygotes are often protected. A second (nonmutually exclusive) possibility is that MHC-disassortative mating preferences promotes inbreeding avoidance. This hypothesis is supported by recent evidence that MHC genes play a role in kin recognition, and that mating with close kin has rather deleterious fitness consequences. In conclusion, I discuss other ways that MHC genes might influence sexual selection. The research on MHC-mediated mating preferences is integrating the study of animal behaviour with other seemingly disparate fields, including sensory biology and immunogenetics.
IRON AND THE SEX DIFFERENCE IN HEART DISEASE RISK

Premenopausal women in affluent societies are protected from heart diseases which kill large numbers of men. The basis for this sex difference and the loss of protection with menopause is unknown. The hypothesis offered is that the greater incidence of heart diseases in men and postmenopausal women compared with the incidence in premenopausal women is due to higher levels of stored iron in these two groups. The hypothesis is supported by observations of (1) myocardial failure in iron strong disease, (2) accumulation of stored iron with age in men, and (3) accumulation of stored iron after menopause to levels found in men. In addition, the heart diseases of affluence are rare among impoverished peoples who are often iron deficient. The depletion of iron stores by regular phlebotomy could be the experimental system for testing this hypothesis, and a preventive therapy if the hypothesis is confirmed.
EVIDENCE THAT MICROCYSTIN IS A THIO‐TEMPLATE PRODUCT1

The hepatotoxic cyclic heptapeptide toxins of cyanobacteria, collectively termed microcystins, are potent inhibitors of protein phosphatases PP1 and PP2A. The structure of microcystins resembles small, cyclic peptide secondary metabolites from fungi and eubacteria. Many of these metabolites are manufactured via a nonribosomal thio-template mechanism. We submit evidence that microcystin is synthesized by a similar mechanism. The organism used in this study was Microcystis aeruginosa PCC7820. Using the traditional ATP-32PPi exchange assay for thio-template activity, we found activity in the presence of the substrate d-amino acids occurring in microcystin. Thio-template mechanisms are known to be unaffected by protein synthesis inhibitors such as chloramphenicol. We subjected cultures in exponential and stationary growth to chloramphenicol and monitored culture health versus toxicity. Although the health of the treated cultures declined, the toxicity of the remaining cells increased. We developed an in vitro assay to measure microcystin synthesis in cell lysates in the presence of chloramphenicol. By supplementing the lysates with ATP and the substrate amino acids present in microcystin, we detected a fourfold increase in total microcystins over the course of 20 min.
Intensity, polarization, and phase information in optical disk systems

Digital information in optical data storage systems can be encoded in the intensity, in the polarization state, or in the phase of a carrier laser beam. Intensity modulation is achieved at the surface of the storage medium either through destructive interference from surface-relief features (e.g., CD or DVD pits) or through reflectivity variations (e.g., alteration of optical constants of phase-change media). Magneto-optical materials make use of the polar magneto-optical Kerr effect to produce polarization modulations of the focused beam reflected from the storage medium. Both surface-relief structures and material-property variations can create, at the exit pupil of the objective lens of the optical pickup, a phase modulation (this, in addition to any intensity or polarization modulation or both). Current optical data storage systems do not make use of this phase information, whose recovery could potentially increase the strength of the readout signal. We show how all three mechanisms can be exploited in a scanning optical microscope to reconstruct the recorded (or embedded) data patterns on various types of optical disk.
Deposition and Etching of Amorphous Carbon Films Prepared by ECR-Plasma-Enhanced Benzene Chemical Vapor Deposition

Amorphous hydrogenated carbon thin films have been deposited from benzene vapor in a microwave electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition (CVD) system. Plasma enhanced dissociation and reaction of benzene were monitored by mass spectrometry. Deposited films were characterized by Fourier transform infrared spectroscopy and fluorescence spectroscopy. The effect of the deposition rate on the film density and plasma etch resistance was also studied. The etch resistance of deposited carbon film is higher than the conventional resist Novolac.
Atmospheric chemistry: Quick cycling of quicksilver

Models predict that mercury undergoes rapid oxidation in the upper atmosphere. Aircraft measurements support this prediction and provide evidence for a previously unrecognized sink for stratospheric mercury.
An optimum organic treatment of nanoclay for PMR-15 nanocomposites

The present study examined ion exchange of layered silicate clay by ammonium ions and investigated thermal dissociation of ammonium ions and the presence of nadic endgroups in ammonium ions on the potential of clay exfoliation in nanocomposites of PMR-15 (an oligomer with molecular weight 1500). A novel method of organoclay exfoliation was used. It involved organoclay intercalation by lower molecular weight PMR-5 oligomer, dispersion of PMR-5/clay mixture in higher molecular weight PMR-15 resin, and curing of the resultant mixtures at approximately 315 °C. The PMR-5 resin residing inside the clay galleries underwent crosslinking during curing and produced higher elastic forces to facilitate clay platelets exfoliation against a slower rising viscous force in the matrix PMR-15 resin. It was found that the ammonium ions with nadic endgroups participated in intra-gallery PMR-5 resin crosslinking reactions and promoted better exfoliation compared to non-reactive ammonium ions. Improvements in thermal and mechanical properties were also observed.
Distributed and fractal pixel sensors

A CMOS active pixel sensor array with anti-aliasing using distributed photodiodes that exhibit a 2-D sinc-like function has been fabricated and tested. Unlike the traditional rectilinear photodiode shapes, the sinc-function diode configurations are interleaved with neighboring pixels. This passive form of focal plane signal processing requires no additional circuitry or power, and depends only on the shape of each pixels sensor. Two such distributed sensor arrays were implemented on a single chip, one with pixels including first-order orthogonal side lobes, and one with first and second-order orthogonal side lobes as well as 1st-order diagonal side lobes. For comparisons, a conventional array with rectangular photodiodes was implemented on the same chip, with the same total sensor area as the second distributed version. Simulations of the filtering effectiveness of various pixel shapes will be presented, as well as measurements of pixel performance including leakage and noise. Of interest, distributed pixel sensors have a relatively larger periphery and hence higher capacitance, increased well-capacity and decreased charge-to-voltage gain relative to equal-area square sensors. The larger periphery raises a concern about increased leakage and noise. However, measurements showed less than 2% increase in leakage current and similarly small differences in noise.
The dynamic mechanical behavior of some nylons

Abstract The dynamic mechanical properties of 6-6 nylon, 6–10 nylon, and a nylon copolymer have been studied in the audio-frequency region over a temperature range extending from about 80°K. to near the melting point by driving rodlike samples in their first transverse mode of oscillation. In all nylon types tested, four dispersion regions are observed, the first three being at temperatures of approximately 170°, 250°, and 350°K. These dispersion regions appear both as peaks in the absorption curve and as relatively sharp drops in the resonance frequency curve. The magnitude and temperature positions of the damping maxima are dependent on the specific nylon type. Over parts of the temperature region the damping of 6-6 nylon depends on the thermal history and water content of the sample. Possible assignments for each of the observed dispersion regions in terms of molecular motion are given. Correlations between the dynamic mechanical data and the results of other physical measurements on the nylons are pointed out.
Making Healthcare Affordable for All: A Proposed Model for Transferring Technology Innovations Case Discussion: Aurolab

vision of its founder Dr. V, and its committed and talented senior management. A significant reason for its success is its large captive customer, the Aravind Eye Care System, which give it the scale needed to commercialize its innovations. With such a ready-made market, Aurolab’s entrepreneurial managers were able to re-engineer technologies available in the West to suit local conditions, and design manufacturing systems that allowed it to provide inexpensive lenses for Aravind’s low cost cataract surgery. Almost 60 percent of the nearly 200,000 surgeries that Aravind performs annually are highly subsidized—most patients pay a basic fee (about half the US$18 cost of surgery), and the other 40 percent, who are provided with additional service features (such as a private room or a hot meal), pay a market price of nearly US$50. The surplus margins gained from this 40 percent of the market provide the fuel for the scale and reach for Aravind’s charitable mission-to-provide eyesight for those in need, regardless of their ability to pay. The average income of an Indian citizen is US$600 and Aravind was able to provide cataract surgery for US$18(cost), or 3 percent of the average income. In the United States, where the average income is US$32,000, the cost of the surgery is US$1,800, or 6 percent. So Aravind’s system innovation is all the more impressive, the surgery is twice as affordable (using a cost benchmark) for the average Indian citizen than his or her U.S. counterpart. At 6 percent of annual income, an Indian surgery at about US$36 or so would still be affordable to the Indian poor. Even so, the price of the lens could not exceed about US$10 to be within the 40 percent cost of supplies for a cataract surgery in India, as shown in Figure 2 of the
Flow of thermoplastics in an annular die under orthogonal oscillations

Abstract Extrusion of several thermoplastics has been carried out through an annular die having the internal surface oscillating in the sound frequency range at different amplitudes. Oscillating shear flow has been imposed orthogonal to the main pressure flow. The die characteristics and average melt temperature at the exit from the die have been measured with and without imposition of oscillations. Modelling of orthogonal superposition of oscillations upon pressure flow has been performed by using the Leonov viscoelastic constitutive equation. Three cases are considered: (i) the process is considered to be isothermal and the change of pressure is only due to a nonlinear interaction of oscillatory and pressure flow; (ii) the process is assumed to be nonisothermal and adiabatic and pressure reduction is due to the nonlinear interaction and the dissipation of oscillatory energy leading to a temperature rise in a polymer melt; (iii) the process is considered to be nonisothermal with heat transfer due to transient heat conduction and the dissipation of oscillatory energy. Pressure reduction occurs due to both nonlinear interaction and temperature rise. It is found that case (i) cannot explain the observed die pressure reduction, while case (ii) does only at high flow rates. The predicted results for case (iii) are found to be in fair agreement with experimental data.
A Citizen-Candidate Model with Sequential Elections

This article develops a citizen-candidate model with sequential elections. The model highlights the strategic considerations associated with the primary process, which hinge on the preferences of party members, in particular the party medians and the party boundaries. It is shown that although electoral competition leads to convergence in platforms, the primary process limits such convergence. Intuitively, this results from candidates having to please two different sets of citizens in successive races (party members in the primary and the electorate as a whole in the general election).
Prolactin replacement must be continuous and initiated prior to 21 d of age to maintain hypothalamic dopaminergic neurons in hypopituitary mice

The prolactin (PRL) deficit in mice homozygous for the spontaneous Ames dwarf (df) mutation coincides with a marked reduction in the number of PRL-regulating tuberoinfundibular dopaminergic (TIDA) neurons. The TIDA deficit develops after 14–21 d postnatally and may be prevented by PRL replacement initiated at 12, but not at 60, d of age. The present study was designed to define further the developmental period during which PRL can prevent the deficit in the number of TIDA neurons in df/df mice, as well as to evaluate whether exposure to PRL neonatally affects the response to PRL by TIDA neurons in later development. To address the first aim, litters of df/df and normal (DF/df) mice were treated daily with ovine PRL (50 µg intraperitoneally), starting at 12, 21, or 30 d of age. To address the second aim, DF/df and df/df animals treated with PRL for 30 d starting at 12 d of age were subjected to PRL withdrawal (15 d of saline vehicle treatment), followed by PRL retreatment. All brains were evaluated using both catecholamine histofluorescence and tyrosine hydroxylase (TH) immunocytochemistry. Total numbers of TH-immunostained cells were counted in area A12 (TIDA neurons) and in A13 (medial zona incerta). Qualitatively, catecholamine fluorescence in A12 perikarya and terminals in df/df mice was enhanced by PRL treatment initiated at 12 or 21, but not at 30, d of age. TH immunostaining intensity was enhanced in all df/df PRL-treated groups, compared with saline treatment. However, total numbers of TH-positive TIDA neurons were reduced significantly in df/df mice treated with PRL beginning at 21 or 30 d, as well as with saline at 12 d, compared with similarly treated DF/df groups and with df/df animals treated with PRL beginning at 12 d (p<0.01 for all comparisons). Among dwarf mice treated with PRL beginning at 12 d, followed by PRL withdrawal, the numbers of TH-positive TIDA neurons were greater than those of saline-treated dwarfs, but less than those in DF/df mice (p<0.05 for both comparisons). In dwarfs retreated with PRL after withdrawal, the TIDA population was also smaller than that in normal animals (p<0.05), although it was larger than in vehicle-treated dwarfs of the same age (p<0.05). No effect of PRL treatment on TIDA cell numbers in normal mice, or of treatment or mouse phenotype on the number of TH-positive cells in zona incerta, occurred in either experiment. These results indicate that the effect of PRL on preventing the reduction in the TIDA population in df/df mice is limited to a developmental period prior to 21 d postnatally. In addition, this study provides evidence that continuous PRL feedback is required to maintain normal numbers of TIDA neurons. These findings extend the evidence for a critical role of PRL feedback in the differentiation and preservation of phenotype in TIDA neurons.
Stresses in Polyimide Films during Cure and Thermal Cycling

Several electronics packaging schemes involve polymer/inorganic interfaces, including: dual-in-line packages, tape automated bonding and multilayer interconnects. Typically, the thermal expansion coefficients are disparate, so these interfaces often cause high stress. Therefore, a phenomenological model describing transient stresses in spin-coated polyimide films was developed. The model is based on linear viscoelastic theory, and it accounts for shrinkage caused by solvent evaporation and imidization, viscoelastic relaxation, and thermal expansion mismatch. Strains have been defined from three mechanisms: thermal expansion mismatch, chemical curing, and solvent evaporation. Stress is, then, calculated by using the Classical Maxwell Model with one element. The concept of free volume is used throughout the model to estimate viscosity, modulus, and other quantities related to calculating strains. Model predictions for stress as a function of temperature during film cure and thermal cycling are fit with experimental data obtained from a bending beam apparatus. Stress has been estimated by using the thin film approximation of the Timoshenko bilayer stress equation. Experimental data agree well with wafer bowing stress measurements. Although the technique does not yet take into account changing polyimide thickness during curing, the results still show qualitative curing dynamics. This preliminary study revealed good agreement between predicted and observed effects of material properties on stresses developed during cure and thermal cycling. Specificially, an unexpected high in-cure stress was observed for a standard low CTE polyimide. High stresses during curing can be as detrimental to an electronics device as high stress during device operation, so this technique may be useful when screening polyimides and/or prescribing curing schedules. Future work will improve the predictive capability of the model.
How to obtain earthquake ground motions for engineering design

Abstract The earthquake ground motions that ultimately are selected for engineering design depend chiefly on the criticality of a site or structure and the engineering analyses that are to be performed. Several key steps are necessary in this selection process: They are (1) a reconnaissance to understand the hazards and obtain preliminary earthquake ground motions; (2) decisions on the application of deterministic or probabilistic methods; (3) selection of appropriate motions for requirements in design; (4) consideration of thresholds at which motions become significant for engineering; and (5) decisions on specifying appropriate earthquake ground motions for sizes of earthquakes, distances from sources, the structures, sites, and testing to be done. This paper presents five tables that show steps for evaluating these factors and for enabling the investigator to specify earthquake ground motions appropriate for engineering design.
Crockett Johnson's geometric paintings

Known as ‘Crockett Johnson’ to admirers of his cartoons and children's books, this talented artist spent the last ten years of his life on an odyssey in mathematics, beginning with the study of historic mathematical milestones, including the three ‘impossible’ construction problems of the classical Greeks. While documenting in abstract paintings the achievements of others, he embarked on his own mathematical investigations, concluding his work with an original solution of the construction of a regular heptagon, using a technique employed by both Archimedes and Newton. Crockett Johnson's abstract paintings present gems in a large body of mathematical knowledge: without symbols, equations, or words, these works of art depict the often hidden beauty of mathematics.
447 GENETIC ASSOCIATION AND LINKAGE IN CONGENITAL ADRENAL HYPERPLASIA DUE TO 21-HYDROXYLASE DEFICIENCY

Twenty-eight families of patients with congenital adrenal hyperplasia due to 21 hydroxylase deficiency (21 OH def.) were studied to evaluate specific HLA antigen association with the disease, & to further investigate the HLA linkage to 21 OH def. gene. The association of 21 OH def. & the HLA A3 antigen was established (p <0.01) in our 28 affected families, & in combined reports of 54 families of North American-West European descent. In 23 unaffected siblings of children with 21 OH def., there was a significant correlation (p <0.01) between the biochemical & HLA determined genotype assignments, providing further evidence of 21 OH def. gene linkage to the HLA complex. However, in one family, we detected the first case of recombination between the 21 OH def. gene & the HLA-B locus. Studies in this family suggest that the 21 OH def. gene is located between the HLA-B and glyoxylase loci. In addition, this suggests that in the genotype assignment of high risk families, both the hormonal and HLA methods of detection should be used.
Use of flow programming in paired-ion high-performance liquid chromatographic analysis of dosage forms containing dyphylline

The use of paired-ion high-performance liquid chromatography (HPLC) for analyzing dosage forms containing dyphylline alone and in combination with other products is described. Liquid dosage forms were diluted and then injected without further treatment. Tablets required a simple extraction using the mobile phase or, in some cases, a modified mobile phase. Flow programming was utilized to hasten the analysis time for those products containing ephedrine and phenobarbital. Chromatographic conditions included a mobile phase consisting of 20 parts acetonitrile and 80 parts water which contained 4 · 10−3M octyl sodium sulfate and 1 % acetic acid. The flow-rate was 2 ml/min for the first 4.5 min and then 5 ml/min for the remaining 5 min. Sodium barbital was the internal standard. This procedure permitted the analysis of dyphylline, guaifenesin, ephedrine and phenobarbital. The HPLC results for dyphylline were compared with results obtained by ultraviolet spectrophotometry. There was no interference from dyes or preservatives.
ATTRIBUTE CONJUNCTIONS AND THE PART CONFIGURATION ADVANTAGE IN OBJECT CATEGORY LEARNING

Five experiments demonstrated that in object category learning people are particularly sensitive to conjunctions of part shapes and relative locations. Participants learned categories defined by a part's shape and color (part-color conjunctions) or by a part's shape and its location relative to another part (part-location conjunctions). The statistical properties of the categories were identical across these conditions, as were the salience of color and relative location. Participants were better at classifying objects defined by part-location conjunctions than objects defined by part-color conjunctions. Subsequent experiments revealed that this effect was not due to the specific color manipulation or the role of location per se. These results suggest that the shape bias in object categorization is at least partly due to sensitivity to part-location conjunctions and suggest a new processing constraint on category learning.
Maximizing in Jajmaniland: A Model of Caste Relations

Insofar as it may be regarded as a purely logicomathematical system, lacking empirical content, economic theory may, by appropriate empirical interpretation, be applied to domains quite apart from the market. Here such use yields a model of caste or jajmani relations. The chief assumptions of the model regarding the stability of a caste system are the following: (1) it requires a high concentration of political power; (2) it requires “prices” that do not change “freely” with supply and demands; (3) it requires consonance of political power, wealth, and ritual rank. These assumptions and various related deductions are tested statistically by data derived from village studies in India, Pakistan, and Ceylon. The evidence indicates that the model is generally plausible and may be applicable to hereditary hierarchies everywhere.
β-Carotene accumulation induced by the cauliflower Or gene is not due to an increased capacity of biosynthesis

The cauliflower (Brassica oleracea L. var. botrytis) Or gene is a rare carotenoid gene mutation that confers a high level of β-carotene accumulation in various tissues of the plant, turning them orange. To investigate the biochemical basis of Or-induced carotenogenesis, we examined the carotenoid biosynthesis by evaluating phytoene accumulation in the presence of norflurazon, an effective inhibitor of phytoene desaturase. Calli were generated from young seedlings of wild type and Or mutant plants. While the calli derived from wild type seedlings showed a pale green color, the calli derived from Or seedlings exhibited intense orange color, showing the Or mutant phenotype. Concomitantly, the Or calli accumulated significantly more carotenoids than the wild type controls. Upon treatment with norflurazon, both the wild type and Or calli synthesized significant amounts of phytoene. The phytoene accumulated at comparable levels and no major differences in carotenogenic gene expression were observed between the wild type and Or calli. These results suggest that Or-induced β-carotene accumulation does not result from an increased capacity of carotenoid biosynthesis.
Interaction of the gonococcal porin P.IB with G- and F-actin.

The invasion of epithelial cells by N. gonorrheae is accompanied by formation of a halo of actin filaments around the enveloped bacterium. The transfer of the bacterial major outer membrane protein, porin, to the host cell membrane during invasion makes it a candidate for a facilitator for the formation of this halo. Western analysis shows here that gonococcal porin P.IB associates with the actin cytoskeleton in infected cells. Using the pyrene-labeled Mg forms of yeast and muscle actins, we demonstrate that under low ionic strength conditions, P.IB causes formation of filamentous actin assemblies, although they, unlike F-actin, cannot be internally cross-linked with N,N'-4-phenylenedimaleimide (PDM). In F-buffer, low porin concentrations appear to accelerate actin polymerization. Higher P.IB concentrations lead to the formation of highly decorated fragmented F-actin-like filaments in which the actin can be cross-linked by PDM. Co-assembly of P.IB with a pyrene-labeled mutant actin, S265C, prevents formation of a pyrene excimer present with labeled S265C F-actin alone. Addition of low concentrations of porin to preformed F-actin results in sparsely decorated F-actin. Higher P.IB concentrations extensively decorate the filaments, thereby altering their morphology to a state like that observed when the components are copolymerized. With preformed labeled S265C F-actin, P.IB quenches the pyrene excimer. This decrease is prevented by the F-actin stabilizers phalloidin and to a lesser extent beryllium fluoride. P.IB's association with the actin cytoskeleton and its ability to interact with and remodel actin filaments support a direct role for porin in altering the host cell cytoskeleton during invasion.
14C as a tracer of labile organic matter in Antarctic benthic food webs

Abstract 14C measurements were made on surface plankton, particle-trap material, surface sediment, benthic invertebrate gut contents, and body tissue samples to assess the effectiveness of this radioisotope as a tracer of labile organic carbon in Antarctic benthic food webs. Samples were collected on five cruises to the West Antarctic Peninsula (WAP) shelf between November 1999 and March 2001 as part of the Food for Benthos on the ANtarctic Continental-Shelf (FOODBANCS) Project. The 14C contents of the body tissues from a variety of deposit feeders (−126±13 per mil) were substantially enriched relative to the surface sediment (−234±13 per mil) and statistically similar to the organic matter collected in plankton tows (−135±10 per mil), indicating that recently produced marine plankton are the primary source of nutrition for these deposit feeders on the West Antarctic shelf. Selective ingestion was the primary feeding strategy used by echiuran worms and certain holothurians (i.e. Peniagone vignoni) for incorporating labile organic carbon into their tissues as demonstrated by the large differences (105±13 per mil) between surface sediment and gut content 14C activities. In contrast, digestive and/or assimilatory selection was the predominant strategy used by an irregular urchin (Amphipneustes lorioli) and several other holothurians (Protelpidia murrayi, Bathyplotes fuscivinculum and the head-down conveyor belt feeder, Molpadia musculus), as demonstrated by large differences (42±7 per mil) between the 14C activities of their foregut or whole-gut organic contents and their body tissues. Despite large fluctuations in carbon export from the euphotic zone, benthic feeding strategies remained essentially constant over the 15-month sampling period. No seasonal variation was evident in either the 14C abundance of the deposit-feeder body tissues, or in the 14C abundance of their gut contents. The mean 14C abundance in the body tissues of the two sub-surface deposit feeders (A. lorioli and M. musculus; mean=−136.2±8.5 per mil) was distinct (p=0.0008) from the mean 14C abundance in the body tissues of the four surface deposit feeders (echiuran worm, P. vignoni, P. murrayi, and B. fusciviculum; −122.6±12.3 per mil). The mean 14C abundance of the gut contents from the sub-surface deposit feeders (−178.0±18.6 per mil) also was significantly depleted (p=0.0009) relative to that of the surface deposit feeders (−149.5±26.6 per mil). The 14C measurements proved to be a much more sensitive tracer for tracking labile organic carbon during ingestive and assimilatory processes than the stable isotopes of carbon or nitrogen.
Microstructure and mechanical properties of a Mg-4Y-3RE alloy processed by thermo-mechanical treatment

Abstract Thermo-mechanical treatments consisting of hot extrusion at 573 or 673 K and artificial aging at 473 K were carried out on a Mg-4Y-3RE alloy. The material extruded at 573 K, followed by aging for 2 h, showed fine needle-like precipitates and the high density of a dislocation cell. This material exhibited a high strength of 370 MPa at room temperature. The material extruded at 673 K exhibited a very small grain size of 1.5 μm and fine spherical precipitates. This material showed not only a high strength of about 300 MPa from room temperature to 473 K, but also superplastic behavior at a high strain-rate of 4×10−1 s−1 and at 673 K. Furthermore, a good combination of high strength and high ductility at room temperature was attained for the material extruded at 673 K. These qualities can likely be attributed to the very small grain size.
Nonalcoholic fatty liver disease in patients with hepatitis C is associated with features of the metabolic syndrome

Abstract Objectives The objectives of this study were to determine the following: 1) whether chronic hepatitis C virus (HCV) infection was specifically associated with nonalcoholic fatty liver disease (NAFLD); 2) the factors associated with NAFLD in patients with HCV; and 3) the clinical and histological spectrum of NAFLD occurring together with HCV. Methods A retrospective analysis of 3826 biopsies was performed to compare the prevalence of NAFLD in those with HCV versus that in other liver diseases, e.g., hepatitis B, primary biliary cirrhosis, and α1-antitrypsin deficiency. Patients with HCV and NAFLD were also compared with an age- and gender-matched control group with HCV and Results The prevalence of NAFLD in patients with HCV was similar to that in hepatitis B, primary biliary cirrhosis, or α1-antitrypsin deficiency. The risk of having NAFLD in patients with HCV correlated with body weight (r = 0.7, p Conclusions The presence of NAFLD in patients with HCV is strongly associated with features of the metabolic syndrome and is a risk factor for advanced fibrosis. Advanced fibrosis in such patients is related to weight, presence of diabetes, and presence and degree of cytological ballooning.
Reduction of axial kinetic energy induced perturbations on observed cyclotron frequency

With Fourier transform ion cyclotron resonance (FTICR) mass spectrometry one determines the mass-to-charge ratio of an ion by measuring its cyclotron frequency. However, the need to confine ions to the trapping region of the ion cyclotron resonance (ICR) cell with electric fields induces deviations from the unperturbed cyclotron frequency. Additional perturbations to the observed cyclotron frequency are often attributed to changes in space charge conditions. This study presents a detailed investigation of the observed ion cyclotron frequency as a function of ion z-axis kinetic energy. In a perfect three-dimensional quadrupolar field, cyclotron frequency is independent of position within the trap. However, in most ICR cell designs, this ideality is approximated only near the trap center and deviations arise from this ideal quadrupolar field as the ion moves both radially and axially from the center of the trap. To allow differentiation between deviations in observed cyclotron frequency caused from changes in space charge conditions or differences in oscillation amplitude, ions with identical molecular weights but different axial kinetic energy, and thus amplitude of z-axis motion, were simultaneously trapped within the ICR cell. This allows one to attribute deviations in observed cyclotron frequency to differences in the average force from the radial electric field experienced by ions of different axial amplitude. Experimentally derived magnetron frequency is compared with the magnetron frequency calculated using SIMION 7.0 for ions of different axial amplitude. Electron promoted ion coherence, or EPIC, is used to reduce the differences in radial electric fields at different axial positions. Thus with the application of EPIC, the differences in observed cyclotron frequencies are minimized for ions of different axial oscillation amplitudes.
Service failures and customer defection: a closer look at online shopping experiences

This study attempts to understand certain aspects of the online shopping experience from a consumer’s perspective. In particular, this study investigates the interaction between service failure and online shops’ readiness for service recovery and the resulting impact on customer defection. The findings of the present study suggest that some online shops have severely breached a few fundamental business principles, resulting in lost customers. Specifically, this study finds that failure to institute adequate complaint management and service recovery systems contributed to customer defection. Hence, service recovery and customer retention need to be given due importance during the service design phase, and appropriate management decisions have to be made upfront rather than after service failures occur when it may be too late.
Risk assessment of oxidant gases and particulate air pollutants: uncertainties and research needs.

Abstract The assessment of risks to human health associated with exposure to oxidant air pollutants has not received adequate attention despite the recognized public health threat posed by the ubiquitous presence of these compounds in the environment. In this article, research needs and uncertainties at each of the steps in the risk assessment of oxidant air pollutants are identified: hazard identification, dose-response assessment, exposure assessment, and risk characterization. Many of these limitations and uncertainties arise at the interface between the laboratory and the regulatory arenas. Therefore, as a case study, relevant methodologic problems associated with the application of experimental findings to the risk assessment of respirable dusts are also discussed. These issues include the extrapolation of animal data to the human case and extrapolation from high-dose to environmentally relevant, low-level exposures.
Both the stimulation and inhibition of root hair growth induced by extracellular nucleotides in Arabidopsis are mediated by nitric oxide and reactive oxygen species

Root hairs secrete ATP as they grow, and extracellular ATP and ADP can trigger signaling pathways that regulate plant cell growth. In several plant tissues the level of extracellular nucleotides is limited in part by ectoapyrases (ecto-NTPDases), and the growth of these tissues is strongly influenced by their level of ectoapyrase expression. Both chemical inhibition of ectoapyrase activity and suppression of the expression of two ectoapyrase enzymes by RNAi in Arabidopsis resulted in inhibition of root hair growth. As assayed by a dose-response curve, different concentrations of the poorly hydrolysable nucleotides, ATPγS and ADPβS, could either stimulate (at 7.5–25 μM) or inhibit (at ≥ 150 μM) the growth rate of root hairs in less than an hour. Equal amounts of AMPS, used as a control, had no effect on root hair growth. Root hairs of nia1nia2 mutants, which are suppressed in nitric oxide (NO) production, and of atrbohD/F mutants, which are suppressed in the production of H2O2, did not show growth responses to applied nucleotides, indicating that the growth changes induced by these nucleotides in wild-type plants were likely transduced via NO and H2O2 signals. Consistent with this interpretation, treatment of root hairs with different concentrations of ATPγS induced different accumulations of NO and H2O2 in root hair tips. Two mammalian purinoceptor antagonists also blocked the growth responses induced by extracellular nucleotides, suggesting that they were initiated by a receptor-based mechanism.
Testing New Submersible Pumps for Proper Sizing and Reduced Costs

This paper describes an ongoing program to improve overall submersible pump performance by Thums Long Beach Company, acting as Contractor of the City of Long Beach, Operator of the Long Beach Unit. Thums Long Beach Company currently operates 700 submersible pump installations located on four man-made islands and one land fill pier location. The program began with spot testing of submersible pumps for Thums' use. It has evolved to 100 percent pump testing and the stipulation that only pumps with newly manufactured parts are acceptable. The primary goals of this program are to increase well production and lower lifting costs. Critical to these goals is increasing the average length of run by using accurate pump performance data to design equipment and by rejecting defective pumps before they are run. Increased production is realized from better designs. Lower lifting costs result from utilizing higher efficiency pumps and a reduced frequency of pulling submersible equipment.