cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of laser-induced antidiffusion on phonon-assisted electron transitions in semiconductor Fokker-Planck equation

By using a first-order time-dependent perturbation theory and including the effect of energy drift from electron transport on the intraband transitions of electrons due to phonons, the kinetic Fokker-Planck equation for conduction electrons in semiconductors is systematically derived in the presence of a laser pulse. A contribution from the anti- diffusion current in the equation is found as a result of the coupling between the spontaneous-phonon emission and the energy drift of electrons due to joule heating by absorbing power from a laser. Analytical expressions for source terms of the equation are given simultaneously up to second-order in perturbation theory, including the stimulated interband optical transitions of electrons from single-photon laser- field absorption, impact ionization due to the Coulomb interaction between electrons and holes, and nonradiative recombination due to the phonon-mediated interaction. Some possible damage mechanisms in semiconductors including optical, electrical, and structural damage are explored. The energy spectra of the electron distribution function are studied and used to analyze the transient behavior of both the conduction electron density and the average kinetic energy of electrons (proportional to the electron temperature). The dynamical effects of anti-diffusion recombination, thermal diffusion and lattice temperature are all shown and explained. A new kink-like feature is observed around the edge of the conduction band in the electron distribution function due to anti-diffusion.
Oxidation at a Dimolybdenum(V) Sulfur Bridge. Formation of SO and SO2 Bridges. Facile Extrusion of SO from the SO2 Bridge

Peroxide oxygenation of μ-thiolate−μ-sulfide Mo(V) dimer complexes of the type [Mo2(NAr)2(S2P(OEt)2)2(μ-O2CMe)(μ-SR)(μ-S)] yielded Mo2(μ-SO) and Mo2(μ-SO2) complexes, demonstrating the reactivity sequence μ-S > μ-SO ≫ μ-SR. Inversion isomers of the pyramidal sulfur site in the μ-SO bridge were observed, and the pyramidicity was confirmed crystallographically. Visible light photolysis of the Mo2(μ-SO2) complex liberated SO from the SO2 bridge and produced Mo2(μ-O) compounds. Crystallography of analogous Mo2(μ-S), Mo2(μ-SO), Mo2(μ-SO2), and Mo2(μ-O) complexes provided structural comparisons related to variations in the bridge functionality. For 2, Mo2C31H44N2O6P2S6: a = 13.604(5) A, b = 15.280(4) A, c = 12.502(2) A, α = 93.36(2)°, β = 112.00 (2)°, γ = 76.01(2)°, triclinic, P1, Z = 2. For 3, Mo2C31H44N2O7P2S6: a = 12.535(2) A, b = 25.299(9) A, c = 13.989(5) A, β = 99.99(2)°, monoclinic, P21/n, Z = 4. For 4, Mo2C31H44N2O8P2S6: a = 12.591(9) A, b = 25.34(1) A, c = 14.048(3) A, β = 100.79(4)°, monoclinic, P...
Biochemical and genetic characterization of ChiA, the major enzyme component for the solubilization of chitin by Cellulomonas uda.

Cellulomonas uda efficiently solubilized chitinous substrates with a simple chitinase system composed of an endochitinase, designated ChiA, which hydrolyzed insoluble substrates into long-chain chitooligosaccharides, and an as yet uncharacterized exochitinase activity. ChiA, isolated from culture supernatant fluids, was found to be a glycosylated endochitinase with an apparent molecular mass of approximately 70 kDa and pI of 8.5. The gene encoding ChiA was cloned in Escherichia coli and sequenced, revealing an open reading frame of 1,716 bp encoding a 571-amino-acid protein with a predicted molecular mass of 59.2 kDa. The region upstream of chiA included a conserved −35 hexamer flanked by two direct repeats analogous to those found in many Streptomyces chitinase promoters, and thought to function as binding sequences for regulatory proteins. Analysis of the deduced amino acid sequence showed a modular protein consisting of a signal peptide at its N terminus, a family 2 carbohydrate-binding module (CBM2) that was closely related to the substrate-binding domains of glycosyl hydrolases from distantly related bacteria, and a family 18 glycosyl hydrolase catalytic module related to Streptomyces chitinases. In contrast to the fibronectin type III domains of Streptomyces chitinases, the linker region between modules in ChiA consisted of a long proline- and threonine-rich module, thought to contribute to the glycosylation and flexibility of the mature protein.
Deposit formation in liquid fuels. 1. Effect of coal-derived Lewis bases on storage stability of Jet A turbine fuel

The development of reasonably precise techniques for the measurement of storage stability of jet aviation fuel is described. Lewis bases, extracted by ligand-exchange from a coal-derived liquid, are shown to adversely affect storage stability (as determined by an accelerated storage test) when added to Jet A turbine fuel. JFTOT results suggesting slight decreases in thermal stability of fuel 'spiked' (i.e., contaminated with a measured quantity of reagent) with extract are reported. Addition to Jet A turbine fuel of individual heterocyclic nitrogen compounds is shown to produce comparable decreases in storage stability.
Tenotomy of the avian anterior latissimus dorsi muscle. II. Can regeneration from the stump occur in the pigeon

Because the chick's anterior latissimus dorsi muscle (ALD) regenerates a fast-twitch muscular connection after tenotomy, the pigeon's ALD was tenotomized, either at the origin or through the muscle 0.5 cm from the origin, to determine whether this muscle behaves similarly to the chick muscle. These procedures were compared in pigeons operated upon at 7 weeks, versus 5 to 9 months of age. The pigeon's ALD did not regenerate a new connection, and other differences were observed between the pigeon and chick ALD. The pigeon ALD has only a single slow muscle-fiber type, has fewer fast fibers, and transforms to a fast-twitch muscle more readily than the chick ALD after tenotomy. The transformation of muscle fiber types occurred more readily in the older pigeons than those tenotomized at 7 weeks of age. Tenotomy induced morphological alterations of the muscle fiber structure in all of the pigeons, which is in contrast to the absence of changes in the tenotomized chick ALD. Therefore the pigeon and chick ALD respond completely differently to tenotomy.
Herbicide and rotation effects on soil and rhizosphere microorganisms and crop yields

Abstract The effects of long-term use of the herbicides, trifluralin and alachlor, on crop yields and microbial populations were determined for continuous and rotated corn and soybeans under field conditions. Seven previous annual herbicide applications produced no lasting differences in populations of soil fungi, cellulolytic bacteria, pectinolytic bacteria, fluorescent Pseudomonas spp., or Gram-positive bacteria. Both herbicides caused temporary fluctuations in the populations of soil and rhizosphere bacteria. The effects of crop rotation on these microbial groups were confined to sampling times following crop residue incorporation. The average yield of rotated soybeans was 12% greater than that of continuous soybeans.
Cross Polarization of Maxwell-Gaussian Laser Beams with Orbital and Spin Angular Momentum

Effects of orbital and spin angular momentum of light beam on cross polarization and focusing properties of Maxwell-Gaussian beams are studied in terms of the solutions of paraxial wave equation.
Calculation of pH near the surface of an electrode covered with a porous film

Abstract The pH adjacent to the surface of a film-covered electrode is generally a difficult quantity to measure. Consequently, we have developed a model to calculate the concentration distribution of a reacting species in a porous film on an electrode surface. Reactions at both the electrode surface and at the film surface within the pore structure are considered. Effects of pore geometry, diffusion rate and reaction rate on concentration distribution are computed from a one-dimensional model. Use of the model in predicting hydroxide ion concentration near the surface of a passivating zinc electrode is demonstrated.
Scaling the microphysics equations and analyzing the variability of hydrometeor production rates in a controlled parameter space

A set of microphysics equations is scaled based on the convective length and velocity scales. Comparisons are made among the dynamical transport and various microphysical processes. From the scaling analysis, it becomes apparent which parameterized microphysical processes present off-scaled influences in the integration of the set of microphysics equations. The variabilities of the parameterized microphysical processes are also studied using the approach of a controlled parameter space. Given macroscopic dynamic and thermodynamic conditions in different regions of convective storms, it is possible to analyze and compare vertical profiles of these processes. Bulk diabatic heating profiles for a cumulus convective updraft and downdraft are also derived from this analysis. From the two different angles, the scale analysis and the controlled-parameter space approach can both provide an insight into and an understanding of microphysics parameterizations.
Lorentz lattice-gas and kinetic-walk model

The Ruijgrok-Cohen (RC) mirror model (Phys. Lett. A 133, 415 (1988)) of a Lorentz lattice gas, in which particles are reflected by left and right diagonally oriented mirrors randomly placed on the sites of a square lattice, is further investigated. Extensive computer simulations of individual trajectories up to 2{sup 24} steps in length, on a lattice of 65 536{times}65 536 sites, are carried out. This model generates particle trajectories that are related to a variety of kinetic growth and smart'' (nontrapping) walks, and provides a kinetic interpretation of them. When all sites are covered with mirrors of both orientations with equal probability, the trajectories are equivalent to smart kinetic walks that effectively generate the hulls of bond percolation clusters at criticality. For this case, 10{sup 6} trajectories were generated, yielding with unprecedented accuracy an orbit size-distribution exponent of {tau}=2.1423{plus minus}0.0003 and a fractal dimension of {ital d}{sub {ital f}}=1.750 47{plus minus}0.000 24 (without correcting for finite-size effects), compared with theoretical predictions of 15/7=2.142 857. . . and 7/4, respectively. When the total concentration of mirrors {ital C} is less than unity, so that the trajectories can cross, the size distribution of the closed orbits does not follow a power law,more » but appears to be described by a logarithmic function.« less
Mass-gathering medicine: a descriptive analysis of a range of mass-gathering event types

Abstract Objective To identify and evaluate the volume, nature, and severity of patient presentations encountered by emergency medical services (EMS) at all mass-gathering events held at or near a southeastern US university. In addition, to compare the existing literature base (single mass-gathering event held in large urban population centers) with a broader variety of events varying in crowd size and locations. Methods This was a retrospective review of all EMS records from mass-gathering patient presentations (individual-patient cases) between October 24, 2009, and August 27, 2011. All patrons seen by event-based EMS were included. Events categories included the following: football, concerts, public exhibitions, and nonfootball athletic events. Event volumes were defined as follows: low ( 15 000 patrons). Case presentation-management categories included the following: trauma, medical, and support (minimal medical intervention required, eg, minor dressing for abrasion, water, etc). Severity categories included the following: mild, moderate, and severe based on the following definitions using both provider assessment and the use of transport to a hospital: minor cases were considered non–life threats and did not result in a transport to a hospital; moderate cases were associated with transports to a hospital; and severe cases were life threats with transport to a hospital. Results We studied 79 events over the study period. Event volumes were 16.45% high, 79.75% medium, and 3.80% low. A total of 670 cases presented, with a mean of 8.48 cases/event. The football category had the highest mean number of cases with 37.09 cases/event, for a total of 408 cases. The nonfootball, athletic event category had the lowest mean number of cases at 1.83 cases/event. Most (81.82%) of the football events were classified as large volume. Support cases were the most common presentation (43.13%), followed closely by medical complaints (41.94%). Most cases were mild in severity (95.97%). There were 27 cases requiring transport to hospital, with 3 cases being life-threatening. The average patient age was 33 years, with 60.3% female sex. These features are similar to the published information on large event medical attendance. Conclusions In this retrospective, descriptive study of a broad range of event type, the most common patient presentations at mass-gathering events were mild in severity, requiring minimal medical intervention. Both transports from the event to a hospital and the occurrence of life threats were uncommon. Our findings are similar to the data found in the existing medical literature.
Biochemical and immunological characterization of the flagellar-associated regulatory subunit of a type II cyclic adenosine 5′-monophosphate-dependent protein kinase

Abstract We have shown previously that the regulatory subunit (RII) of a type II cyclic AMP (cAMP)-dependent protein kinase is tightly associated with mammalian sperm flagella (J. A. Horowitz et al. (1984) J. Biol. Chem.259, 832–838; J. A. Horowitz et al. (1988) J. Biol. Chem.263, 2098–2104). In the present study the flagellar RII was compared to other well-characterized RIIs using biochemical and immunological methods. Flagellar polypeptides were screened by immunoblot analysis with monoclonal antibodies directed against the RIIα and RIIβ isoforms. An RIIβ monoclonal antibody failed to cross-react with any flagellar polypeptide. In contrast, mAB 622, an RII α RII β monoclonal antibody, cross-reacted with a 57,000 Da polypeptide. However, another RII α RII β monoclonal antibody interacted weakly with the flagellar RII, suggesting that the epitope for this antibody is modified in flagellar RII. Partial peptide mapping of 8-azido-[32P]cAMP-labeled RIIs revealed that although heart and testis generated similar fragmentation patterns, there were differences in the maps from flagellar RII. Two-dimensional sodium dodecyl sulfate-gel electrophoresis of 8-azido-[32P]cAMP-labeled RII from rat flagella and bovine heart showed that the former possessed a considerably more acidic isoelectric point. Partial proteolysis of the flagellar RII by either endogenous or exogenous proteases resulted in the cleavage of RII to a 40,000 Mr fragment. Complete release of this fragment from the flagellum was achieved if proteolysis was performed in the presence of thiol reducing agents. In their absence, approximately 50% of the fragment remained bound to the flagellum. The soluble proteolytic fragment was shown to be monomeric by native high-resolution gel-permeation chromatography and contained a functional cAMP-binding site(s).
Mental disorder diagnostic theory and practical reality: an evolutionary perspective.

In the current legislative debate about mandating parity of insurance coverage for mental disorders, many question the use of DSM-IV diagnostic criteria to indicate benefit eligibility. Some have i...
China motorization trends: New directions for crowded cities

This paper examines two major emerging constraints on transport in fast-growing Chinese urban cities: oil supply and urban infrastructure. The research considers automobile technology, alternative fuels, and mobility choices, as well as policy measures that could be adopted to reduce the use of oil for transport and greenhouse gas emissions. Three transport energy scenarios, “Road Ahead,” “Oil Saved,” and “Integrated Transport,” illustrate potential motorization trends given different policy, vehicle technology, alternative fuels, and driving-behavior assumptions. In the Integrated Transport scenario, where congestion and space constraints favor small and vehicles moving at slower speeds, gasoline and electric cars are the highest in use. Oil consumption in the Integrated Transport scenario is only 12 percent of its value in Road Ahead by 2020, while carbon emission is 79 percent lower. Policies such as vehicle technology and fuel requirements, while important, are not as crucial as integrated land use development, taxation of vehicle use, road pricing, and the prioritization of public and non-motorized transport that could trigger a world of fewer, smaller and more efficient cars. According to experiences around the world, fuel and carbon dioxide concerns alone are not strong enough to promote a change in the path of individual motorization.
Bismuth: Annual survey covering the year 1986

Ce rapport est une synthese des etudes effectuees sur les composes organiques du bismuth en 1986
Increasing colorectal cancer screening among individuals in the carpentry trade: test of risk communication interventions.

Abstract Background Individuals in the carpentry trade, due to lifestyle habits and occupational exposures, may be at above-average risk for colorectal cancer (CRC). Based on the literature which suggests that increasing perceived risk motivates behavior change, we report on the effectiveness of four risk-communication interventions targeted to increase initial, yearly and repeat fecal occult screening (FOBT) among carpenters (N = 860) over a 3-year period. Methods Our 2 × 2 factorial design intervention study varied two dimensions of providing CRC risk factor information: (1) type of risk factor—one set of interventions emphasized three basic risk factors (age, family history and polyps); the other set emphasized a comprehensive set of risk factors including basic, lifestyle, and occupational factors, and (2) tailoring/not tailoring risk factor information. Participants were provided FOBTs. Outcomes were the proportion of returned FOBTs. Results Varying the amount and intensity of delivering CRC risk factors information affected neither risk perceptions nor initial, yearly, or repeat screening. However, yearly and repeat screening rates were greater among participants who received interventions addressing comprehensive set of risk factors, especially with increasing age. Conclusions Tailoring on several CRC risk factors appears insufficient to increase and sustain elevated perceptions of CRC risks to promote screening.
Multicell stage of the Munich storm of 12 July 1984: a numerical study

The multicell stage of the Munich hailstorm is investigated using a three-dimensional, non-hydrostatic mesoscale model. During this stage, the storm developed in a wind profile that had little directional shear yet an extensive series of two-dimensional numerical experiments could not produce a self-sustaining and realistic convective system. The modelled storm is a multicellular, three-dimensional system featuring right-flank development of new cells. It is constituted of two principal flow branches, namely, an intense updraught that travels at the speed of a mid-level steering current and a weak downdraught. A mid-level relative inflow overtakes the storm from the rear but undergoes unsaturated descent of only about 100 mb, fails to establish the classical downdraught associated with mid-latitude storms, and exits ahead of the storm. Weak, shallow downdraughts originate beneath an inversion and from ahead of the storm. Viewed in a cross section parallel to the direction of storm motion, trajectory analyses show that the cold pool is fed by two types of shallow downdraught, namely a gravity or solitary wave undergoes minimal vertical displacement and an overturning jump that causes substantial evaporative cooling despite its small vertical displacement. A density current circulation fails to form in this plane but one does develop in the perpendicalur section and its interaction with the convergence field and vertical shear causes secondary cell initiation at right angles to that found in multicell squall lines. DOI: 10.1034/j.1600-0870.1992.t01-3-00006.x
Does gum chewing help prevent impaired gastric motility in the postoperative period

Purpose To discuss the pathophysiology of postoperative ileus (POI) and the addition of gum chewing to a multimodal treatment plan. Data sources Review of current literature of the pathophysiology of POI, multimodal treatment options, and current research on gum chewing and its effects on the prevention of POI. Conclusions Studies have documented that gum chewing decreases time to flatus and first defecation after surgery. Studies indicate that gum chewing can decrease the length of hospital stay by 1 day. There were no documented adverse effects of gum chewing. The addition of gum chewing to a multimodal treatment program assists with increasing patient comfort, satisfaction, and decreasing healthcare expenditures. Implications for practice POI is a common complication of abdominal surgery. Research has indicated that gum chewing has assisted with increasing gastric motility, decreasing lengths of hospital stays, and decreasing healthcare expenditures. Gum chewing is an inexpensive and safe option to add to a multimodal program for the prevention of POI.
Production of fuel-cell grade hydrogen by thermal swing sorption enhanced reaction concept

Abstract The performance of a novel thermal swing sorption enhanced reaction (TSSER) concept for production of fuel-cell grade hydrogen ( 20 ppm CO ) by low temperature ( ∼ 490 ∘ C ) catalytic steam–methane reforming (SMR) is simulated. The process simultaneously carries out the SMR reaction and removal of CO 2 from the reaction zone by chemisorption on K 2 CO 3 promoted hydrotalcite in a single unit. The chemisorbent is periodically regenerated by steam purge at ∼ 590 ∘ C . The concept efficiently utilizes the CO 2 sorption capacity of the chemisorbent and requires a relatively low amount of steam for its regeneration. A compact, small foot-print H 2 generator can be designed for a residential or industrial hydrogen fuel-cell unit by the concept. Recently measured equilibrium isotherms and column dynamics for ad(de)sorption of CO 2 on the chemisorbent are reviewed and parametric evaluations of design variables like catalyst:sorbent ratio and feed gas conditions (pressure, temperature, and H 2 O : CH 4 ratio) are carried out.
Effectiveness and long–term results of laparoscopic common bile duct exploration

Background: Laparoscopic common bile duct exploration (LCBDE) is a cost-effective, efficient, and minimally invasive method of treating choledocholithiasis. We reviewed the long-term results and efficacy of LCBDE for the common bile duct (CBD) stones in patients undergoing laparoscopic cholecystectomy (LC). Methods: Medical charts were reviewed for all patients undergoing LCBDE at St. Vincent Hospital over 11 years (1990-2001). Demographic data, clinical features, laboratory data, radiologic and operative findings, and postoperative follow-up evaluation were analyzed. Results: A total of 346 LCBDE were performed during the study period. The mean operative time was 127 ± 3 min, and the length of hospital stay averaged 2.8 ± 0.1 days. In 8 patients (2.3%), LCBDE was converted to an open procedure. Complications were noted in 33 patients (9.5%), including patients (2.7%) with retained stones. No postoperative mortalities were recorded. No long-term strictures or biliary complications were noted over a mean follow-up period of 43 months (follow-up data available for 96%). Conclusion: A policy of routine cholangiography and LCBDE for CBD stones was effective in clearing the bile duct and avoiding further hepatobiliary instrumentation. The findings show that LCBDE can be performed successfully with low morbidity and mortality.
The Effects of Metropolitan Residence on the Off‐Farm Earnings of Farm Families in the United States1

Previous research on the effects of urbanization on farming and farm families has focused on the consequences of urban expansion on farming practice rather than on the well-being of farm families. Proximity to urban areas has been found to alter the way farm families utilize the nonfarm labor market. In this study, the off-farm earnings of husbands and wives in farm families are compared across metropolitan (metro) and nonmetropolitan (nonmetro) areas using data from the March supplement to the 1989 Current Population Survey. Censored regression models (tobit) and decomposition are used to demonstrate the effects of nonfarm labor market differences on off-farm labor force participation and earnings. The analysis reveals that farm family members, as expected, have significantly higher rates of participation and earnings in metropolitan areas. But this analysis also reveals that increases in off-farm participation are likely to have a larger effect on total off-farm earnings in nonmetropolitan areas than returns to those already working off-farm. The potential for increases in off-farm earnings will be underestimated in nonmetro areas when changes in participation in the off-farm labor market are not taken into account.
Relation et responsabilité : Vers un processus de réconciliation

Qu’est-ce qui constitue une reponse ethique au devoilement de la verite qui s’est passe dans le contexte des auditions de la Commission de verite et reconciliation au Quebec et au Canada ? En utilisant l’autoethnographie et la structure de la theologie contextuelle, l’auteur se faufile a travers l’exemple de l’histoire de sa famille a Gespe’gewa’gi (Gaspe). L’article montre comment l’identite coloniale des colons et leur blancheur sont liees a la theologie chretienne Euro-centrique et informent celle-ci. Apres avoir considere l’experience autochtone de la terre et des enseignements ancestraux sur la relation, la responsabilite et les protocoles, l’article se base sur des exemples hermeneutiques ecologiques et la theologie feministe postcoloniale pour recuperer au coeur des Ecritures chretiennes de la responsabilite et de la reciprocite, a la fois dans l’Alliance et les traditions radicales de don. L’article invite les lecteurs a entamer un processus de decolonisation d’eux-memes et de leurs traditions pour aller de l’avant sur le chemin de la reconciliation, sur un pied d’egalite avec les peuples autochtones, leurs partenaires.
Dihydrogen/Dihydride or Tetrahydride? An Experimental and Computational Investigation of Pincer Iridium Polyhydrides

The iridium pincer complexes (PCP)IrH(4) (1; PCP = [kappa(3)-1,3-(CH(2)P(t)Bu(2))(2)C(6)H(3)]) and (POCOP)IrH(4) (2; POCOP = [kappa(3)-1,3-(OP(t)Bu(2))(2)C(6)H(3)]) have proven to be effective catalyst precursors for dehydrogenation of alkanes. The complex (POCOP)IrH(2) has also been applied successfully as a catalyst for release of H(2) from ammonia borane. Investigation of the "tetrahydride" forms of these complexes by solution NMR methods suggests their formulation as dihydrogen/dihydride species. This is in contrast to the solid state structure of 1, determined by neutron diffraction (at 100 K), which indicates a compressed tetrahydride structure with only weak H-H interactions. Complex 1 (C(24)H(47)IrP(2)) crystallizes in the space group P4(2), tetragonal, (Z = 2) with a = 11.7006 (19) A, c = 9.7008(27) A, and V = 1328.1(5) A(3). Electronic structure calculations on 1 and 2 indicate that the global minima on the potential energy surfaces in the gas phase are tetrahydride structures; however, the dihydrogen/dihydride forms are only slightly higher in energy (1-3 kcal/mol). A dihydrogen/dihydride species is calculated to be the global minimum for 2 when in solution. The barriers to interconversion between the tetrahydride and dihydrogen/dihydride species are almost negligible.
The effects of restricted food access upon locomotor activity in rats with suprachiasmatic nucleus lesions.

Abstract The purpose of the study was to investigate the ability of rats with suprachiasmatic nucleus (SCN) lesions to anticipate restricted food access (RFA). The sham operated controls demonstrated entrainment of locomotor activity to a LD 12:12 cycle with ad libitum food and water, while the lesioned animals were arrhythmic in their running behavior. When exposed to constant light (LL) and presentation of food once every 24 hours, anticipatory wheel running was observed in both groups. A return to ad lib food and the previous LD 12:12 schedule produced a slow re-entrainment of running in the controls and arrhythmic activity in the SCN animals. The results suggest that the SCN is not necessary for the appearance of locomotor rhythms in the rat.
Effects of counter-ions on the performance of IPMCs

Ionic Polymer-Metal Composites (IPMCs) are materials capable of exhibiting large motion sensing and actuation capabilities in an electric field produced by a small voltage. Laboratory observations on the behavior of IPMC in an electric field strongly establish the presence, of water movement due to electrophoretic migration of hydrated counter-ions or simply cations. In this paper, the effects of counter-ions on the performance of IPMCs in sensing and actuation are discussed. Samples of IPMCs were carefully prepared in a standard size of 0.25 x 1 inch strip containing various monovalent and divalent metal cations including Na + , Li + , K + , H + , Ca ++ , Mg ++ , and Ba ++ . Given a sinusoidal wave input of 1.2 volts with Hz, the IPMC having Li + shows the best performance in terms of force generation. Such results strongly indicate that sulfonate exchange sites are the relatively low charge sites and therefore the hydration process (rather than electrostatic field interaction) plays a much more important role. It is noted that water absorptivity and the phenomenon of exchange site clustering depend on the type of cations. Furthermore, the experimental results strongly indicate the importance of the hydration process. Muscle performance characteristics are reported and a simple phenomenological model for forces and fluxes is also presented.
Racial and Ethnic Differences in the Home Food Environment Explain Disparities in Dietary Practices of Middle School Children in Texas

Abstract Objective To examine racial and ethnic differences among middle school children in the home food environment (HFE) and the extent to which associations of healthy and unhealthy eating with the HFE differ by race and ethnicity. Design Cross-sectional secondary analyses of baseline data from Coordinated Approach to Child Health Middle School, a school-based intervention targeting obesity and obesogenic behaviors among middle school children in Austin, TX. Participants A total of 2,502 children (mean age, 13.9 years; 58% Hispanic, 28% white, and 14% black). Variables Measured Availability and accessibility of healthy foods, and parental support of healthy eating, and family meals. Consumption of both healthy and unhealthy foods was examined. Analysis Differences across racial and ethnic groups in aspects of HFE were estimated using linear regression. Models also examined racial and ethnic differences in consumption of healthy and unhealthy foods. If adjusting for HFE, such differences were accounted for. Results White children had significantly better HFEs than Hispanic and black children with greater availability and accessibility of healthy foods ( P Conclusions and Implications Improved HFE may increase healthy eating among ethnic minorities but is unlikely to reduce unhealthy eating.
Effect of establishment date and crop competition on burcucumber fecundity

Abstract An experiment examining the effect of burcucumber emergence date and corn competition on burcucumber fecundity was conducted in 1997 and 1998 in central Pennsylvania. Burcucumber seedlings were transplanted in the field in approximately 10-d intervals starting in late May through mid-August with or without competition from corn. Burcucumber plants grown without competition from corn produced 716 g dry matter and 4,500 seeds plant−1 in 1997 and 607 g dry matter and 1,800 seeds plant−1 in 1998. Biomass was greatest for plants established in late May, whereas seed production was greatest for plants established in mid-June. Although seed numbers were reduced in comparison to the May and June establishment periods, plants established as late as August still produced seed. Burcucumber established in corn produced 96% less dry matter and seed than the plants in a noncompetitive environment in both years of the study. Although the growth and seed production of burcucumber grown in corn was drastically re...
Halocarbon measurements in the Alaskan troposphere and lower stratosphere

Abstract Halocarbon measurements were made over Alaska in May 1975 from onboard a Learjet and subsequently in the laboratory on captured air samples. The data sets demonstrate two phenomena: 1. (1) a rapid decrease in the halocarbon concentrations across the tropopause into the lower stratosphere, and 2. (2) variable concentration gradients either decreasing or increasing upward from the tropopause depending upon day-to-day meteorological conditions. An air mass transport mechanism through the tropopause into the stratosphere is proposed to explain the temporal and spatial variations observed.
Synthesis and Characterization of (2,6-iPrNCN)HfCl2- and (3,5-MeNCN)2Hf2- (where NCN = 2,6-bis[phenylazanidyl]methylphenyl): New Trianionic Pincer Ligands

The synthesis, isolation, and metalation of the trianionic NCN-pincer ligand [2,6-iPrNCNLi3]2 (2) is described. The terdentate coordination ability of 2 is demonstrated in the synthesis of the hafn...
Signaling Profiling at the Single-Cell Level Identifies a Distinct Signaling Signature in Murine Hematopoietic Stem Cells†‡§

Hematopoietic stem cell (HSC) function is tightly regulated by cytokine signaling. Although phospho-flow cytometry allows us to study signaling in defined populations of cells, there has been tremendous hurdle to carry out this study in rare HSCs due to unrecoverable critical HSC markers, low HSC number, and poor cell recovery rate. Here, we overcame these difficulties and developed a "HSC phospho-flow" method to analyze cytokine signaling in murine HSCs at the single-cell level and compare HSC signaling profile to that of multipotent progenitors (MPPs), a cell type immediately downstream of HSCs, and commonly used Lin(-) cKit(+) cells (LK cells, enriched for myeloid progenitors). We chose to study signaling evoked from three representative cytokines, stem cell factor (SCF) and thrombopoietin (TPO) that are essential for HSC function and granulocyte macrophage-colony-stimulating factor (GM-CSF) that is dispensable for HSCs. HSCs display a distinct TPO and GM-CSF signaling signature from MPPs and LK cells, which highly correlates with receptor surface expression. In contrast, although majority of LK cells express lower levels of cKit than HSCs and MPPs, SCF-evoked ERK1/2 activation in LK cells shows a significantly increased magnitude for a prolonged period. These results suggest that specific cellular context plays a more important role than receptor surface expression in SCF signaling. Our study of HSC signaling at the homeostasis stage paves the way to investigate signaling changes in HSCs under conditions of stress, aging, and hematopoietic diseases.
Immunologic Studies of Poisonous Anacardiaceae: I. Production of Tolerance and Desensitization to Poison Ivy and Oak Urushiols Using Esterified Urushiol Derivatives in Guinea Pigs

The development of contact sensitivity to poison ivy urushiol in Hartley guinea pigs was inhibited by i.v. injection of the diacetate esters of poison ivy and oak urushiols into guinea pigs 2weeks prior to attempted sensitization with homologous antigen. immune tolerance to urushiols of poison ivy and oak developed in 80% or more of the treated animals and persisted for the duration of the study, 8weeks. The tolerance was immunologically specific for urushiols since the tolerant animals were sensitizable to the unrelated sensitizer 2,4-dinitrochlorobenzene. Guinea pigs already sensitive to urushiol were also desensitized or hyposensitizied by i.v. injection of urushiol acetates in successively increasing doses. After receiving the equivalent of 16mg of poison ivy and oak urushiols in the acetate form over a period of 12weeks, 54% of a group of guinea pigs were desensitized to poison ivy. All of the remaining 46% of the guinea pigs still sensitive to poison ivy were substantially hyposensitized (no longer responded to 1.5 or 0.80 μ g test doses of PDC). A control group of guinea pigs was not hyposensitized by injections of vehicle, and remained highly sensitive throughout the 15week study. The majority of treated animals (>80%) were also hyposensitized to poison sumac and cashew nut shell liquid allergens.
Genetic activity of allyl chloride.

Abstract Allyl chloride (3-chloroprene) is mutagenic for Salmonella typhimurium and it induces gene conversions in Saccharomyces cereuisiae . It also displays DNA-modifying activity for E. coli . This is in contrast to a recent study which reported its lack of genetic activity for Salmonella typhimurium .
Age-Related Differences in Locus of Control Orientation in Three Behavior Domains

Age-correlated differences in locus of control (LOC) orientation were examined for 306 persons age 13 to 90 in three areas of activity: intellectual, social, and physical. On the scales measuring LOC
Measuring electrophysiological changes in transgenic mouse models of cardiovascular disease.

See article by Eloff et al. [19] (pages 681–690) in this issue. The ability to remove selected genes within the mouse genome has proven to be an invaluable tool in the study of vertebrate biology. Many genetically modified ‘knockout’ mice possess significant morphological abnormalities that have provided substantial insights into the function of individual genes. However, the severity of the phenotype is often the drawback to using knockout mice as disease models, since many human diseases are due to subtle genetic defects. This is especially true for genetic alterations that manifest as electrophysiological disturbances in the heart, as cardiac conduction defects, substrates for arrhythmias, and susceptibility to sudden cardiac arrest may arise without any obvious morphological abnormalities. Cardiac function requires the organized contractility of billions of myocytes. Propagation of electrical current from cell-to-cell is mediated by gap junctions, which are membrane channels that allow the transfer of ions, metabolites and other signaling molecules between neighboring cells [1–3]. In the heart, this chemical exchange permits the rapid conduction of action potentials [3–5]. The protein components of gap junctions are referred to as connexins. These proteins transverse the membrane four times and interact with connexins on adjacent cells by homophilic binding of the extracellular domains [1–3,6]. Three distinct connexin genes are known to be expressed within the adult myocardium: Connexin40 (Cx40), Cx43 and Cx45. Cx40 is preferentially exhibited in atrial tissue and the His-Purkinje system [7,8]. The distribution of Cx45 is restricted to the atrioventricular conduction system in a pattern that is similar, although not identical, to that of Cx40 [9]. The predominant connexin of the mammalian heart is Cx43, which is expressed at … *Corresponding author. Tel.: +1-843-792-6502; fax: +1-843-792-0664
TEACHING EVIDENCE-BASED PRACTICE AT THE BSW LEVEL: AN EFFECTIVE CAPSTONE PROJECT

Developing student competencies related to evidence-based practice (EBP) is becoming increasingly important as an evidence-based approach to practice becomes more salient in the field. Although there has been significant discussion in the literature about how to teach EBP at the master's level, there is far less discussion about such instruction in baccalaureate programs. This article describes an undergraduate senior capstone project, which, in partnership with internship activities, developed students' familiarity with EBP concepts and improved their abilities to search for and use interventions from the professional literature. Findings from a survey study of the project indicated that students felt better prepared to use best practices and that the project enhanced their overall sense of competence as practitioners.
A software environment for simultaneous dynamic optimization

We describe a software environment for dynamic optimization using the simultaneous approach. Over the past few years, there has been significant development in the formulation of simultaneous dynamic optimization problems, using collocation on finite elements, and in the solution of the resulting large-scale nonlinear programming problem, using powerful barrier NLP solvers. Here we describe the background of the simultaneous approach as well as the components that make up the formulation and modeling environment, which we call DynoPC. DynoPC incorporates state-of-the-art NLP and DAE solvers along with a powerful automatic differentiation package. Moreover, it has a number of advanced features including model reduction and moving finite elements. Finally, we describe how DynoPC can be interfaced to other environments using Equation Set Objects (ESO) and the MINLP CAPE-OPEN object. All of these concepts are illustrated with three dynamic optimization examples including a large-scale industrial case study.
STATUS OF JOINT GENERAL ELECTRIC-MARITIME ADMINISTRATION HEAVY DUTY GAS TURBINE DEVELOPMENT PROGRAM

The United States Maritime Administration and the Gas Turbine Products Division of the General Electric Company have joined in a five-year, cost-sharing program to promote the domestic maritime industry using improved concepts of heavy duty gas turbine design. This paper describes the elements of that program and reports on the progress at its midpoint, two and one-half years following its inception. The status of project development goals and technical attainments to date indicate that the contractual objectives of both parties are being attained.Copyright © 1973 by ASME
Universal coverage one head at a time--the risks and benefits of individual health insurance mandates.

To address problems with universal coverage, some reform models incorporate an individual mandate, a legal requirement that every person obtain insurance coverage. Sherry Glied writes that the individual mandate in the U.S. plans, however, has become a flash point for controversy. Professor Sherry Glied discusses individual health insurance mandates, the difficulties of enforcement, and recent experience in Massachusetts and California.
Evidence for a rapid in vivo effect on estradiol-17 beta on prolactin secretion in ovariectomized rats.

Repeated intraarterial injections of synthetic thryrotropin releasing hormone (TRH, 1 ug/rat) increased plasma prolactin levels 4 hours, after a single subcutaneous injection of 10 ug estradiol-17β (E2-17β) in rats ovariectomized 1, 2 or 4 weeks and at 2 hours after E2-17β injection in rats ovariectomized for 6 weeks. The effect of TRH was still present at 24 but not 48 hours after estradiol treatment. TRH-induced increases in plasma prolactin were similar in groups of rats treated with 10 ug E2-17β (s.c.) or implanted with 0.5 cm Silastic capsules of crystalline E2-17β (s.c.) wheareas smaller, yet significan, TRH-induced increases in plasma prolactin were observed in rats injected s.c. with 1.0 ug E2-17β. Single intraarterial injections of TRH at 4 or 8 hours after E2-17β treatment induced increases in plasma prolactin similar in magnitude to those observed at the same times after E2-17β in rats given repeated TRH injections. No effect of TRH was observed in ovariectomized rats given sesame oil and E2-17...
Myosin ATP turnover rate is a mechanism involved in thermogenesis in resting skeletal muscle fibers.

Thermogenesis by resting muscle varies with conditions and plays an active role in homeostasis of body weight. The low metabolic rate of living resting muscles requires that ATP turnover by myosin be inhibited relative to the purified protein in vitro. This inhibition has not been previously seen in in vitro systems. We used quantitative epifluorescence microscopy of fluorescent nucleotides to measure single nucleotide turnovers in relaxed, permeable skeletal muscle fibers. We observed two lifetimes for nucleotide release by myosin: a fast component with a lifetime of ≈20 s, similar to that of purified myosin, and a slower component with a lifetime of 230 ± 24 s. We define the latter component to be the “super relaxed state.” The fraction of myosins in the super relaxed state was decreased at lower temperatures, by substituting GTP for ATP or by increased levels of myosin phosphorylation. All of these conditions have also been shown to cause increased disorder in the structure of the thick filament. We propose a model in which the structure of the thick filament modulates the nucleotide turnover rates of myosin in relaxed fibers. Modulation of the relative populations of the super relaxed and conventional relaxed states could have a profound effect on muscle thermogenesis, with the capacity to also significantly alter whole-body metabolic rate.
The synaptic organization of the prepacemaker nucleus in weakly electric knifefish, Eigenmannia: a quantitative ultrastructural study.

Weakly electric knifefish (Eigenmannia sp.) produce continuous electric organ discharges at very constant frequencies. Modulations of the discharges occur during social interactions and are under control of the diencephalic prepacemaker nucleus. Abrupt frequency modulations, or ‘chirps’, which are observed predominantly during the breeding season, can be elicited by stimulation of neurons in a ventro-lateral portion of the prepacemaker nucleus, the so-called PPn-C. The PPn-C consists of approximately 100 loosely scattered large multipolar neurons which send dendrites into three territories, called ‘dorso-medial’, ‘dorso-lateral’, and ‘Ventral’. In the present ultrastructural investigation, the synaptic organization of these neurons, identified by retrograde labelling with horseradish peroxidase, was studied quantitatively.
A People of Migrants: Ethnicity, State and Religion in Karachi

A People of Migrants: Ethnicity, State and Religion in Karachi. OSKAR VERKAAIK. Amsterdam: Free University Press, 1994. 89 pp., references, notes.
Sonographic demonstration of calculi within a urethral diverticulum

A case in which sonography demonstrated that calculi may arise in female urethral diverticula is presented. The diagnosis of female urethral diverticula is reviewed.
Contact Potentials of Reversible Soluble Films of Lauric Acid

WHEN a nearly saturated solution of lauric acid in distilled water is placed in an Adam-Jessop film-pressure trough, the soluble adsorbed film may be compressed or swept in the same manner as an in soluble film of a higher fatty acid. However, the surface is rapidly replenished by diffusion from below, after sweeping, or the compressed film diffuses down-ward. In either case the reading of the film-balance returns to zero, in a period of about thirty minutes at 25° C. Similar effects have been noticed with benzopurpurin solutions1 and with soap solutions2. Since the contact potential of solutions is proportional to the concentration of the surface-active solute, simultaneous contact potential measurements with a polonium-covered silver electrode on the above surfaces might be expected to yield potential-time curves nearly parallel to the force-time curves. Such proved to be the case, with the following notable differences.
Veil of Dishonour: Sexual jealousy and suicide on Fiji plantations ∗

(1985). Veil of Dishonour: Sexual jealousy and suicide on Fiji plantations. The Journal of Pacific History: Vol. 20, No. 3, pp. 135-155.