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Sample records for apparent molal volumes

  1. Apparent Molal Volumes of Sodium Fluoride in Mixed Aqueous-Ethanol Solvents

    Directory of Open Access Journals (Sweden)

    E. Gomaa

    2010-09-01

    Full Text Available The densities of different molal concentrations of sodium fluoride at ethanol-water mixtures, as solvent, have been measured over the whole composition range at three different temperatures, 293.15, 303.15 and 313.15oK. From the measured densities, the apparent and limiting molal volumes of the electrolytes have been evaluated. The limiting molal volumes for sodium and fluoride ions were estimated by splitting the ionic contributions as an asymmetric assumption.

  2. Apparent molal volumes of symmetrical and asymmetrical isomers of tetrabutylammonium bromide in water at several temperatures

    International Nuclear Information System (INIS)

    Highlights: • Apparent molal volumes of five isomers of Bu4NBr in water have been measured. • The structural effect of branched and linear chains is discussed. • The structural contributions to the ionic volume were calculated. -- Abstract: Apparent molal volumes of a series of differently substituted quaternary ammonium bromides, namely tetra-iso-butyl-, tetra-sec-butyl-, tetra-n-butyl-, di-n-butyl-di-sec-butyl- and di-n-butyl-di-iso-butylammonium bromide have been determined as a function of molal concentration at (298.15, 303.15 and 308.15) K. Partial molar volumes at infinite dilution and ionic molar volumes of these quaternary ammonium cations were determined. Structural volume contributions to the ionic molar volume were also calculated. The symmetric and asymmetric quaternary ammonium cations are “structure making” ions. The contribution of the branched butyl chains predominates over the linear butyl chains in the asymmetric cations

  3. Study of apparent molal volume and viscosity of mutual citric acid and disodium hydrogen orthophosphate aqueous systems

    Indian Academy of Sciences (India)

    Man Singh

    2006-05-01

    Fundamental properties, density () and viscosity (), of citric acid (CA) and disodium hydrogen orthophosphate (DSP) at various strengths were obtained at different temperatures. The and values were used to determine apparent molal volumes and viscosity of systems. The , and values were regressed against molality for ρ0, 0 and $V^{0}_{\\phi}$f, the limiting constants at infinite dilution ( → 0) forionic and molecular interactions. The ρ0 and $V^{0}_{\\phi}$f of aq. acids are higher than those of aq. DSP and the viscosity of DSP is higher than that of aq. CA. Examination of ρ0 and $V^{0}_{\\phi}$ functions indicates that mutual compositions of CA and DSP counterbalance concentration and temperature effects on pH in bioprocesses.

  4. Apparent molar volumes of aqueous calcium chloride to 250{degrees}C, 400 bars, and from molalities of 0.242 to 6.150

    Energy Technology Data Exchange (ETDEWEB)

    Oakes, C.S.; Bodnar, R.J. [Virginia Polytechnic Inst. and Univ., Blacksburg, VA (United States); Simonson, J.M. [Univ. of California, Berkeley, CA (United States)

    1995-09-01

    Relative densities of CaCl{sub 2}(aq) with 0.242 {le} m/(mol-kg{sup {minus}1}) {le} 6.150 were measured with vibrating-tube densimeters between 25 and 250{degrees}C and near 70 and 400 bars. Apparent molar volumes V{sub {null}} calculated from the measured density differences were represented with the Pitzer ion-interaction treatment, with appropriate expressions chosen for the temperature and pressure dependence of the virial coefficients of the model. It was found that the partial molar volume at infinite dilution V{sub {null}}{sup o}, and the second and third virial coefficients B{sup v} and C{sup v}, were necessary to represent V{sub {null}} near the estimated experimental uncertainty. The ionic-strength dependent {Beta}{sup 1}{sup v} term in the B{sup v} coefficient was included in the fit. The representation for V{sub {null}} has been integrated with respect to pressure to establish the pressure dependence of excess free energies over the temperature range studied. The volumetric data indicate that the logarithm of the mean ionic activity coefficient, ln {gamma}{plus_minus}(CaCl{sub 2}), increases by a maximum of 0.3 at 400 bars, 250{degrees}C, and 6 mol-kg{sup {minus}1} as compared with its value at saturation pressure.

  5. The molal volumes of atropine and hyoscine in relation to their respective potencies.

    OpenAIRE

    Cohen, S.; Haberman, F.

    1984-01-01

    The partial molal volumes, V2, at infinite dilution of atropine and hyoscine were determined in each of eight different solvents having cohesive energy densities in the range 64 to 144 cal cm-3. V2 for hyoscine in a given solvent was invariably and significantly smaller than that of atropine in the same solvent. The difference being 1.58 cm3 mol-1 in the least polar solvent (n-propylbenzene) and 4.29 cm3 mol-1 in the most polar one (acetonitrile) in the series studied. It is proposed that the...

  6. The (p, ρ, T) properties and apparent molar volumes Vφ of (ZnBr2 + C2H5OH)

    International Nuclear Information System (INIS)

    The (p, ρ, T) properties and apparent molar volumes Vφ of ZnBr2 in ethanol at temperatures (293.15 to 393.15) K and pressures up to p = 40 MPa are reported. The measurements were made with a recently developed vibration-tube densimeter. The system was calibrated using double-distilled water, methanol, ethanol, and aqueous NaCl solutions. The experiments were carried out at molalities of m = (0.05681, 0.16958, 0.30426, 0.43835, 0.93055, 1.49016, and 1.88723) mol . kg-1 using zinc bromide. An empirical correlation for the density of (ZnBr2 + C2H5OH) with pressure, temperature, and molality has been derived. This equation of state was used to calculate other volumetric properties such as isothermal compressibility, isobaric thermal expansibility, the differences in specific heat capacities at constant pressures and volumes, apparent molar volumes of ZnBr2 in ethanol, and partial molar volumes of both components.

  7. Osmotic coefficients and apparent molar volumes of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid in alcohols

    International Nuclear Information System (INIS)

    Highlights: • Physical and osmotic properties of [HMim][TfO] in alcohols are reported. • Apparent molar properties and osmotic coefficients were obtained. • Apparent molar volumes were fitted using a Redlich–Meyer type equation. • The osmotic coefficients were modeled with the Extended Pitzer and the MNRTL models. -- Abstract: In this work, density for the binary mixtures of 1-hexyl-3-methylimidazolium trifluoromethanesulfonate in alcohols (1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol) was measured at T = 323.15 K and atmospheric pressure. From this property, the corresponding apparent molar volumes were calculated and fitted to a Redlich–Meyer type equation. For these mixtures, the osmotic and activity coefficients, and vapor pressures of these binary systems were also determined at the same temperature using the vapor pressure osmometry technique. The experimental osmotic coefficients were modeled by the Extended Pitzer model of Archer. The parameters obtained in this correlation were used to calculate the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures

  8. Thermodynamics on the Molality Scale

    Science.gov (United States)

    Canagaratna, Sebastian G.; Maheswaran, M.

    2013-01-01

    For physical measurements, the compositions of solutions, especially electrolyte solutions, are expressed in terms of molality rather than mole fractions. The development of the necessary thermodynamic equations directly in terms of molality is not common in textbooks, and the treatment in the literature is not very systematic. We develop a…

  9. Apparent molar volumes and compressibilities of selected electrolytes in dimethylsulfoxide

    International Nuclear Information System (INIS)

    Densities at T = (293.15, 298.15, 303.15, 313.15, 323.15, and 333.15) K and sound velocities at T = 298.15 K of tetraphenylphosphonium bromide, sodium tetraphenylborate, sodium bromide, and sodium perchlorate in dimethylsulfoxide have been measured over the composition range from (0 to 0.3) mol . kg-1. From these data, apparent molar volumes and apparent molar isentropic compressibilities at infinite dilution as well as the expansibilities have been evaluated. The results have been discussed in terms of employing tetraphenylphosphonium tetraphenylborate as a reference electrolyte in splitting the limiting apparent molar volumes and apparent molar isentropic compressibilities into ionic contributions.

  10. Apparent molar volumes and apparent molar heat capacities of aqueous D-lactose · H2O at temperatures from (278.15 to 393.15) K and at the pressure 0.35 MPa

    International Nuclear Information System (INIS)

    Apparent molar volumes Vphi and apparent molar heat capacities Cp,phi were determined for aqueous solutions of D-lactose · H2O at molalities (0.01 to 0.34) mol · kg-1 at temperatures (278.15 to 393.15) K, and at the pressure 0.35 MPa. Our Vphi values were calculated from densities obtained using a vibrating tube densimeter, and our Cp,phi values were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter. Our results for D-lactose(aq) and for D-lactcose · H2O were fitted to functions of m and T and compared with the literature results for aqueous D-glucose and D-galactose solutions. Infinite dilution partial molar volumes V2compfn and heat capacities Cp,2compfn are given over the range of temperatures

  11. (p, ρ, T) properties, and apparent molar volumes V φ of ZnBr2 in methanol at T = (298.15 to 398.15) K and pressures up to p = 40 MPa

    International Nuclear Information System (INIS)

    The (p, ρ, T) properties of pure methanol, the (p, ρ, T) properties and apparent molar volumes V φ of ZnBr2 in methanol at T (298.15 to 398.15) K and pressures up to p = 40 MPa are reported, and apparent molar volumes have been evaluated. The experimental (p, ρ, T, m) values were described by an equation of state. For the solutions the experiments were carried out at molalities m = (0.05772, 0.37852, 0.71585 and 1.95061) mol . kg-1 of zinc bromide

  12. Apparent molar volumes and compressibilities of selected electrolytes in dimethylsulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Warminska, Dorota, E-mail: dorota@chem.pg.gda.p [Department of Physical Chemistry, Chemical Faculty, Gdansk University of Technology, 80-233 Gdansk (Poland); Grzybkowski, Waclaw [Department of Physical Chemistry, Chemical Faculty, Gdansk University of Technology, 80-233 Gdansk (Poland)

    2010-12-15

    Densities at T = (293.15, 298.15, 303.15, 313.15, 323.15, and 333.15) K and sound velocities at T = 298.15 K of tetraphenylphosphonium bromide, sodium tetraphenylborate, sodium bromide, and sodium perchlorate in dimethylsulfoxide have been measured over the composition range from (0 to 0.3) mol . kg{sup -1}. From these data, apparent molar volumes and apparent molar isentropic compressibilities at infinite dilution as well as the expansibilities have been evaluated. The results have been discussed in terms of employing tetraphenylphosphonium tetraphenylborate as a reference electrolyte in splitting the limiting apparent molar volumes and apparent molar isentropic compressibilities into ionic contributions.

  13. Apparent molar volumes and apparent molar heat capacities of dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

    International Nuclear Information System (INIS)

    Apparent molar volumes Vphi and apparent molar heat capacities Cp,phi have been determined for dilute aqueous solutions of ethanol, 1-propanol, and 2-propanol at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa. The molalities investigated ranged from 0.05 mol·kg-1 to 1.0 mol·kg-1. We used a vibrating tube densimeter (DMA 512P, Anton PAAR, Austria) to determine the densities and volumetric properties. Heat capacities were obtained using a twin fixed-cell, power-compensation, differential-output, temperature-scanning calorimeter (NanoDSC 6100, Calorimetry Sciences Corporation, American Fork, UT, USA). The results were fit by regression to equations that describe the surfaces (Vphi,T,m) and (Cp,phi,T,m). Infinite dilution partial molar volumes V20 and heat capacities C0p,2 were obtained over the range of temperatures by extrapolation of these surfaces to m=0 mol·kg-1

  14. Apparent molar volumes and apparent molar heat capacities of aqueous nickel(II) nitrate, copper(II) nitrate, and zinc(II) nitrate at temperatures from (278.15 to 393.15) K at the pressure 0.35 MPa

    International Nuclear Information System (INIS)

    Apparent molar volumes Vphi and apparent molar heat capacities Cp,phi were determined for aqueous solutions of nickel(II) nitrate, copper(II) nitrate, and zinc(II) nitrate at molalities m=(0.01 to 0.5) mol · kg-1, and at the pressure p=0.35 MPa. Solution densities obtained using a vibrating-tube densimeter at T=(278.15 to 368.15) K were used to calculate Vphi values. Heat capacity measurements obtained with a twin fixed-cell, differential-output, power-compensating, temperature-scanning calorimeter at T=(278.15 to 393.15) K were used to calculate values of Cp,phi. Our results were then fitted to functions of m and T and compared to literature values

  15. Apparent molar volumes and compressibilities of alkaline earth metal ions in methanol and dimethylsulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Warminska, Dorota, E-mail: dorota@chem.pg.gda.p [Department of Physical Chemistry, Chemical Faculty, Gdansk University of Technology, 80-233 Gdansk (Poland); Wawer, Jaroslaw; Grzybkowski, Waclaw [Department of Physical Chemistry, Chemical Faculty, Gdansk University of Technology, 80-233 Gdansk (Poland)

    2010-09-15

    Temperature dependencies of density of magnesium (II), calcium (II), strontium (II), barium (II) perchlorates as well as beryllium (II), and sodium trifluoromethanesulfonates in methanol and dimethylsulfoxide have been determined over the composition range studied. From density data the apparent molar volumes and partial molar volumes of the salts at infinite dilution as well as the expansibilities have been evaluated. The apparent molar isentropic compressibilities of alkaline earth metal perchlorates and beryllium (II) and sodium triflates in methanol and DMSO have been calculated from sound speed data obtained at T = 298.15 K.

  16. Apparent molar volumes and compressibilities of alkaline earth metal ions in methanol and dimethylsulfoxide

    International Nuclear Information System (INIS)

    Temperature dependencies of density of magnesium (II), calcium (II), strontium (II), barium (II) perchlorates as well as beryllium (II), and sodium trifluoromethanesulfonates in methanol and dimethylsulfoxide have been determined over the composition range studied. From density data the apparent molar volumes and partial molar volumes of the salts at infinite dilution as well as the expansibilities have been evaluated. The apparent molar isentropic compressibilities of alkaline earth metal perchlorates and beryllium (II) and sodium triflates in methanol and DMSO have been calculated from sound speed data obtained at T = 298.15 K.

  17. Apparent molar volumes and compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates in dimethylsulfoxide

    International Nuclear Information System (INIS)

    Highlights: ► Sequence of volumes and compressibilities of Ln3+ ions in DMSO is: La3+ > Gd3+ 3+. ► Sequence of the partial molar volumes do not change with temperature. ► These results are the consequence of nature of the ion–solvent bonding. - Abstract: Temperature dependencies of the densities of dimethylsulfoxide solutions of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been determined over a wide range of concentrations. The apparent molar volumes and partial molar volumes of the salts at infinite dilution, as well as the expansibilities of the salts, have been calculated from density data. Additionally, the apparent molar isentropic compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been calculated from sound velocity data at 298.15 K. The data obtained have been interpreted in terms of ion−solvent interactions.

  18. Apparent molar volumes and apparent molar heat capacities of aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa

    International Nuclear Information System (INIS)

    Apparent molar volumes V φ were determined for aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa, and apparent molar heat capacities C p,φ of the same solutions were determined at temperatures from (278.15 to 363.15) K at the same pressure. Molalities m/(mol . kg-1) of the solutions were in the range (0.02 ≤ m ≤ 3.2) for adonitol, (0.02 ≤ m ≤ 0.15) for dulcitol, (0.02 ≤ m ≤ 5.0) for glycerol, (0.02 ≤ m ≤ 3.0) for meso-erythritol, (0.02 ≤ m ≤ 0.5) for myo-inositol, (0.02 ≤ m ≤ 2.0) for D-sorbitol, and (0.02 ≤ m ≤ 2.7) for xylitol. A vibrating tube densimeter was used to obtain solution densities and a fixed-cell temperature scanning calorimeter was used to obtain heat capacities. Values of V φ and C p,φ for these sugar alcohols are discussed relative to one another and compared to values from the literature, where available

  19. Apparent molar volumes and apparent molar heat capacities of aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Blodgett, M.B. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Ziemer, S.P. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Brown, B.R. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Niederhauser, T.L. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Woolley, E.M. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States)]. E-mail: earl_woolley@byu.edu

    2007-04-15

    Apparent molar volumes V {sub {phi}} were determined for aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa, and apparent molar heat capacities C {sub p,{phi}} of the same solutions were determined at temperatures from (278.15 to 363.15) K at the same pressure. Molalities m/(mol . kg{sup -1}) of the solutions were in the range (0.02 {<=} m {<=} 3.2) for adonitol, (0.02 {<=} m {<=} 0.15) for dulcitol, (0.02 {<=} m {<=} 5.0) for glycerol, (0.02 {<=} m {<=} 3.0) for meso-erythritol, (0.02 {<=} m {<=} 0.5) for myo-inositol, (0.02 {<=} m {<=} 2.0) for D-sorbitol, and (0.02 {<=} m {<=} 2.7) for xylitol. A vibrating tube densimeter was used to obtain solution densities and a fixed-cell temperature scanning calorimeter was used to obtain heat capacities. Values of V {sub {phi}} and C {sub p,{phi}} for these sugar alcohols are discussed relative to one another and compared to values from the literature, where available.

  20. Apparent volumes of distribution of 125I-lothalamate and inulin in chickens (38781)

    International Nuclear Information System (INIS)

    The suitability of utilizing 125I-iothalamate to estimate the volume of extracellular fluid was assessed in ureterally ligated chickens. Subsequent to intravenous administration the movement of labeled iothalamate from the plasma compartment follows closed two-compartment kinetics and equilibration between vascular and extravascular phases is attained in about 20 minutes. The volume of distribution of 125I-iothalamate prior to and following the infusion of 0.15 M NaCl (equal to 15 percent of the estimated ECFV) averaged 23.6 +- 0.61 and 28.4 +- 0.22 percent of the body weight, respectively. The observed postsaline labeled iothalamate space did not differ statistically from the expected value. When administered simultaneously inulin penetrates into an apparent volume that is 75 percent of the labeled iothalamate space after 60 minutes. The content of 125I-iothalamate is relatively high in liver and kidney tissue and suggests that these are major sites where removal of the indicator from plasma occur. It is suggested that 125I-iothalamate, under appropriate conditions, could be used to measure the plasma volume and the extravascular fluid with which plasma is in rapid diffusion equilibrium. (U.S.)

  1. Various estimates of Representative Volume Element sizes based on a statistical analysis of the apparent behavior of random linear composites

    OpenAIRE

    Salmi, Moncef; Auslender, François; Bornert, Michel; Fogli, Michel

    2012-01-01

    This article aims at proposing various estimates of the size of the Representative Volume Element (RVE) of random linear elastic matrix-inclusion composites. These estimates are derived from the computation of the apparent behavior of finite size volume elements (VE) by a new procedure presented in . [18] by Salmi et al. (2012) and briefly recalled. Two different points of view to define an RVE are considered: the RVE is defined as being the smallest VE required either to evaluate numerically...

  2. Apparent diffusion coefficients in GEC ESTRO target volumes for image guided adaptive brachytherapy of locally advanced cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Haack, Soeren (Dept. of Clinical Engineering, Aarhus Univ. Hospital (Denmark)), E-mail: Soeren.haack@stab.rm.dk; Morre Pedersen, Erik (Dept. of Radiology, Aarhus Sygehus, Aarhus Univ. Hospital (Denmark)); Jespersen, Sune N. (Center of Functionally Integrative Neuroscience, Aarhus Univ. Hospital (Denmark)); Kallehauge, Jesper F. (Dept. of Medical Physics, Aarhus Univ. Hospital (Denmark)); Lindegaard, Jacob Christian; Tanderup, Kari (Dept. of Oncology Aarhus Univ. Hospital (Denmark))

    2010-10-15

    Background and purpose. T2 weighted MRI is recommended for image guided adaptive brachytherapy (IGABT) in cervical cancer. Diffusion weighted imaging (DWI) and the derived apparent diffusion coefficient (ADC) may add additional biological information on tumour cell density. The purpose of this study was to evaluate the distribution of the ADC within target volumes as recommended by GEC-ESTRO: Gross Tumour Volume at BT (GTVBT), High-Risk Clinical Tumour Volume (HR-CTV) and Intermediate-Risk Clinical Target Volume (IR-CTV) and to evaluate the change of diffusion between fractions of IGABT. Material and methods. Fifteen patients with locally advanced cervical cancer were examined by MRI before their first (BT1) and second (BT2) fraction of IGABT, resulting in a total of 30 MR examinations including both T2 weighted and DWI sequences. The Apparent Diffusion Coefficient (ADC) was calculated by use of three levels of b-values (0, 600, 1000 s/mm2). ADC maps were constructed and fused with the GEC ESTRO target contours. The mean ADC value within each target volume was calculated. Furthermore, volumes of low diffusion (ADClow) were defined based on an ADC threshold of 1.2 x 10-3 mm2/s, and overlap with target volumes was evaluated. Change of ADC level in target volumes and change of ADClow volume from BT1 to BT2 was also evaluated. Results. The mean ADC was significantly lower in GTVBT than in HR-CTV (p<0.001) which again was significantly lower than in IR-CTV (p<0.001). There was no significant change of the ADClow volume or ADC level within each target structure between BT1 and BT2 (p=0.242). All three GEC-ESTRO volumes contained volumes with low diffusion. The GTVBT contained 37.2% volume of low diffusion, HR-CTV 20.3% and IR-CTV 10.8%. Conclusion. With DWI we were able to find a significant difference in ADC-values for the three different GEC ESTRO targets. This supports the assumption that the target volumes used for dose prescription in IGABT contain tissues with

  3. Why Size Matters: Differences in Brain Volume Account for Apparent Sex Differences in Callosal Anatomy

    OpenAIRE

    Luders, Eileen; Toga, Arthur W.; Thompson, Paul M.

    2013-01-01

    Numerous studies have demonstrated a sexual dimorphism of the human corpus callosum. However, the question remains if sex differences in brain size, which typically is larger in men than in women, or biological sex per se account for the apparent sex differences in callosal morphology. Comparing callosal dimensions between men and women matched for overall brain size may clarify the true contribution of biological sex, as any observed group difference should indicate pure sex effects. We thus...

  4. Estimating the apparent culm volume for Bambusa oldhamii and Bambusa vulgaris = Estimação do volume aparente de colmos de Bambusa oldhamii e Bambusa vulgaris.

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Sanquetta

    2015-06-01

    Full Text Available There is great potential in Brazil for the cultivation of indigenous and introduced species of bamboo. However, there is little scientific research on the biometric aspects of these plants, and this may limit their management and use. The aim of this article therefore, is to present options for estimating the total apparent volume of two species of the genus Bambusa: B. oldhami i and B. vulgaris, planted in an experiment set up in December of 2008 in Pinhais, in the state of Paraná, Brazil (PR. Twenty-four stems were cubed at 50 months using the Smalian method. Diameter at breast height (DAP ranged from 1.8 to 4.5 cm, and height from 3 to 7 m. The options being tested for estimating the apparent volume of the culms were: 1 Schumacher-Hall conventional volume model; 2 fifth-degree polynomial taper model; 3 fractional-power polynomial taper model; and 4 form factor. The options were examined statistically relative to the observed values for the target variable, for each species and for both species as a set. It was found that the four options give precise estimates. There was no statistical difference between the four approaches and the control (observed values by paired t-test. The residuals (estimated x observed values are shown to be homoscedastic with a maximum width of from -30 to 30%. It was concluded that the four methods under test can be used to estimate the target variable under the conditions of the experimental material. The Schumacher-Hall model represents the best compromise between simplicity and accuracy = O Brasil possui grande potencial de cultivo de espécies autóctones e introduzidas de bambu. Contudo, são poucos os trabalhos científicos que versam sobre aspectos biométricos dessas plantas, o que pode representar uma limitação para seu manejo e utilização. Assim, objetivou-se com esse artigo apresentar opções para estimativa do volume total aparente de duas espécies do gênero Bambusa: B. oldhamii e B. vulgaris

  5. Calculation of the Standard Molal Thermodynamic Properties of Crystalline, Liquid, and Gas Organic Molecules at High Temperatures and Pressures

    Science.gov (United States)

    Helgeson, Harold C.; Owens, Christine E.; Knox, Annette M.; Richard, Laurent

    1998-03-01

    Calculation of the thermodynamic properties of organic solids, liquids, and gases at high temperatures and pressures is a requisite for characterizing hydrothermal metastable equilibrium states involving these species and quantifying the chemical affinities of irreversible reactions of organic molecules in natural gas, crude oil, kerogen, and coal with minerals and organic, inorganic, and biomolecular aqueous species in interstitial waters in sedimentary basins. To facilitate calculations of this kind, coefficients for the Parameters From Group Contributions (PFGC) equation of state have been compiled for a variety of groups in organic liquids and gases. In addition, molecular weights, critical temperatures and pressures, densities at 25°C and 1 bar, transition, melting, and boiling temperatures ( Tt,Pr, Tm,Pr, and Tv,Pr, respectively) and standard molal enthalpies of transition (Δ H° t,Pr), melting (Δ H° m,Pr), and vaporization (Δ H° v,Pr) of organic species at 1 bar ( Pr) have been tabulated, together with an internally consistent and comprehensive set of standard molal Gibbs free energies and enthalpies of formation from the elements in their stable state at 298.15 K ( Tr) and Pr (Δ G° f and Δ H° f, respectively). The critical compilation also includes standard molal entropies ( S°) and volumes ( V°) at Tr and Pr, and standard molal heat capacity power function coefficients to compute the standard molal thermodynamic properties of organic solids, liquids, and gases as a function of temperature at 1 bar. These properties and coefficients have been tabulated for more than 500 crystalline solids, liquids, and gases, and those for many more can be computed from the equations of state group additivity algorithms. The crystalline species correspond to normal alkanes (C nH 2( n+1) ) with carbon numbers ( n, which is equal to the number of moles of carbon atoms in one mole of the species) ranging from 5 to 100, and 23 amino acids including glycine (C 2H 5NO

  6. Osmotic and apparent molar properties of binary mixtures alcohol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid

    International Nuclear Information System (INIS)

    Highlights: ► Osmotic and physical properties of binary mixtures {alcohol + [BMim][TfO]} were measured. ► From experimental data, apparent molar properties and osmotic coefficients were calculated. ► The apparent properties were fitted using a Redlich–Meyer type equation. ► The osmotic coefficients were correlated using the Extended Pitzer model. -- Abstract: In this work, physical properties (densities and speeds of sound) for the binary systems {1-propanol, or 2-propanol, or 1-butanol, or 2-butanol, or 1-pentanol + 1-butyl-3-methylimidazolium trifluoromethanesulfonate} were experimentally measured from T = (293.15 to 323.15) K and at atmospheric pressure. These data were used to calculate the apparent molar volume and apparent molar isentropic compression which were fitted to a Redlich–Meyer type equation. This fit was used to obtain the corresponding apparent molar properties at infinite dilution. On the other hand, the osmotic and activity coefficients and vapor pressures of these binary mixtures were also determined at T = 323.15 K using the vapor pressure osmometry technique. The Extended Pitzer model of Archer was employed to correlate the experimental osmotic coefficients. From the parameters obtained in the correlation, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures were calculated

  7. Temperature, pressure, and electrochemical constraints on protein speciation: Group additivity calculation of the standard molal thermodynamic properties of ionized unfolded proteins

    Directory of Open Access Journals (Sweden)

    J. M. Dick

    2006-01-01

    Full Text Available Thermodynamic calculations can be used to quantify environmental constraints on the speciation of proteins, such as the pH and temperature dependence of ionization state, and the relative chemical stabilities of proteins in different biogeochemical settings. These calculations depend in part on values of the standard molal Gibbs energies of proteins and their ionization reactions as a function of temperature and pressure. Because these values are not generally available, we calculated values of the standard molal thermodynamic properties at 25°C and 1 bar as well as the revised Helgeson-Kirkham-Flowers equations of state parameters of neutral and charged zwitterionic reference model compounds including aqueous amino acids, polypeptides, and unfolded proteins. The experimental calorimetric and volumetric data for these species taken from the literature were combined with group additivity algorithms to calculate the properties and parameters of neutral and ionized sidechain and backbone groups in unfolded proteins. The resulting set of group contributions enables the calculation of the standard molal Gibbs energy, enthalpy, entropy, isobaric heat capacity, volume, and isothermal compressibility of unfolded proteins in a range of proton ionization states to temperatures and pressures exceeding 100°C and 1000 bar. This approach provides a useful frame of reference for thermodynamic studies of protein folding and complexation reactions. It can also be used to assign provisional values of the net charge and Gibbs energy of ionized proteins as a function of temperature and pH. Using these values, an Eh-pH diagram for a reaction representing the speciation of extracellular proteins from Pyrococcus furiosus and Bacillus subtilis was generated. The predicted predominance limits of these proteins correspond with the different electrochemical conditions of hydrothermal vents and soils. More comprehensive calculations of this kind may reveal pervasive

  8. On the Relationship Between the Apparent Diffusion Coefficient and Extravascular Extracellular Volume Fraction in Human Breast Cancer

    OpenAIRE

    Arlinghaus, Lori R.; Xia LI; Rahman, A. Ridwan; Welch, E. Brian; Xu, Lei; Gore, John C.; Yankeelov, Thomas E.

    2011-01-01

    MRI techniques have been developed that can noninvasively probe the apparent diffusion coefficient (ADC) of water via diffusion weighted MRI (DW-MRI). These methods have found much application in cancer where it is often found that the ADC within tumors is inversely correlated with tumor cell density, so that an increase in ADC in response to therapy can be interpreted as an imaging biomarker of positive treatment response. Dynamic contrast enhanced MRI (DCE-MRI) methods have also been develo...

  9. Group additivity calculation of the standard molal thermodynamic properties of aqueous amino acids, polypeptides and unfolded proteins as a function of temperature, pressure and ionization state

    Directory of Open Access Journals (Sweden)

    J. M. Dick

    2005-10-01

    Full Text Available Thermodynamic calculation of the chemical speciation of proteins and the limits of protein metastability affords a quantitative understanding of the biogeochemical constraints on the distribution of proteins within and among different organisms and chemical environments. These calculations depend on accurate determination of the ionization states and standard molal Gibbs free energies of proteins as a function of temperature and pressure, which are not generally available. Hence, to aid predictions of the standard molal thermodynamic properties of ionized proteins as a function of temperature and pressure, calculated values are given below of the standard molal thermodynamic properties at 25°C and 1 bar and the revised Helgeson-Kirkham-Flowers equations of state parameters of the structural groups comprising amino acids, polypeptides and unfolded proteins. Group additivity and correlation algorithms were used to calculate contributions by ionized and neutral sidechain and backbone groups to the standard molal Gibbs free energy (Δ G°, enthalpy (Δ H°, entropy (S°, isobaric heat capacity (C°P, volume (V° and isothermal compressibility (κ°T of multiple reference model compounds. Experimental values of C°P, V° and κ°T at high temperature were taken from the recent literature, which ensures an internally consistent revision of the thermodynamic properties and equations of state parameters of the sidechain and backbone groups of proteins, as well as organic groups. As a result, Δ G°, Δ H°, S° C°P, V° and κ°T of unfolded proteins in any ionization state can be calculated up to T~-300°C and P~-5000 bars. In addition, the ionization states of unfolded proteins as a function of not only pH, but also temperature and pressure can be calculated by taking account of the degree of ionization of the sidechain and backbone groups present in the sequence. Calculations of this

  10. Apparent molar volumes and viscosity B-coefficients of caffeine in aqueous thorium nitrate solutions at T = (298.15, 308.15, and 318.15) K

    International Nuclear Information System (INIS)

    Apparent molar volumes φV and viscosity B-coefficients for caffeine in (0.00, 0.03, 0.05, and 0.07) mol . dm-3 aqueous thorium nitrate, Th(NO3)4, solutions were determined from solution density and viscosity measurements over the temperature range (298.15 to 318.15) K as function of concentration of caffeine and the relation: φV0=a0+a1T+a2T2, have been used to describe the temperature dependence of the standard partial molar volumes φV0. These results have been used to deduce the standard volumes of transfer ΔφV0 and viscosity B-coefficients of transfer ΔB for caffeine from water to aqueous Th(NO3)4 solutions for rationalizing various interactions in the ternary solutions. The structure-making or breaking ability of caffeine has been discussed in terms of the sign of (δ2φV0/δT2)P. The Friedman-Krishnan co-sphere model was used to explain the transfer volume of caffeine with increasing Th(NO3)4 molarity. The activation parameters of viscous flow for the ternary solutions were also discussed in terms of transition state theory.

  11. Apparent molar volumes and viscosity B-coefficients of caffeine in aqueous thorium nitrate solutions at T = (298.15, 308.15, and 318.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Biswajit, E-mail: biswachem@gmail.co [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India); Roy, Pran Kumar; Sarkar, Bipul Kumar; Brahman, Dhiraj [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India); Roy, Mahendra Nath, E-mail: mahendraroy2002@yahoo.co.i [Department of Chemistry, University of North Bengal, Darjeeling 734013 (India)

    2010-03-15

    Apparent molar volumes phi{sub V} and viscosity B-coefficients for caffeine in (0.00, 0.03, 0.05, and 0.07) mol . dm{sup -3} aqueous thorium nitrate, Th(NO{sub 3}){sub 4}, solutions were determined from solution density and viscosity measurements over the temperature range (298.15 to 318.15) K as function of concentration of caffeine and the relation: phi{sub V}{sup 0}=a{sub 0}+a{sub 1}T+a{sub 2}T{sup 2}, have been used to describe the temperature dependence of the standard partial molar volumes phi{sub V}{sup 0}. These results have been used to deduce the standard volumes of transfer DELTAphi{sub V}{sup 0} and viscosity B-coefficients of transfer DELTAB for caffeine from water to aqueous Th(NO{sub 3}){sub 4} solutions for rationalizing various interactions in the ternary solutions. The structure-making or breaking ability of caffeine has been discussed in terms of the sign of (delta{sup 2}phi{sub V}{sup 0}/deltaT{sup 2}){sub P}. The Friedman-Krishnan co-sphere model was used to explain the transfer volume of caffeine with increasing Th(NO{sub 3}){sub 4} molarity. The activation parameters of viscous flow for the ternary solutions were also discussed in terms of transition state theory.

  12. Molal Enthalpy of Solution of Ionic Liquid [C2mim][GaCl4

    Institute of Scientific and Technical Information of China (English)

    GUAN,Wei; LIU,Li; WANG,Caixia; YANG,Jiazhen

    2009-01-01

    An ionic liquid (IL),[C2mim][GaCl4](l-ethyl-3-methylimidazolium chlorogallate),was prepared by directly mixing 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]) and anhydrous GaCI3 with a molar ratio of 1/1 under dry argon.The molal enthalpies of solution,△sHm,of [C2mim][GaCl4],were measured over a molality range of about 0.008-0.1 mol·kg 1 by a solution reaction isoperibol calorimeter at 298.15 K.Considering the hydrolization of anion [GaCl4]- in dissolution process of the IL,a new method of determining the standard molal enthalpy of solution,△sH(⊙)m,was put forward on the basis of Pitzer's mixed electrolyte solution theory so that △sH(⊙)m = -132kJ·mol-1 and the sum of Pitzer's parameters;4β(0)GaCl + 4β(0)[C2mim].Cl + ΦGa,[C2mim]= -0.1373076,β(1)LGa,Cl + β(1)L[C2mim].C=0.3484209 were obtained.In terms of thermodynamic cycle and Glasser's theory of lattice energy for IL,the dissociation enthalpy of [GaCl4]-(g),△Hdis([GaCl4]-)≈5855 kJ·mol-1,that is enthalpy change for the reaction:[GaCl4]-(g)→Ga3+(g) +4Cl- (g),was estimated.

  13. (p, ρ, T) properties and apparent molar volumes V φ of CaCl2 in methanol at T = (298.15 to 398.15) K and pressure up to 40 MPa

    International Nuclear Information System (INIS)

    The (p, ρ, T) properties and apparent molar volumes V φ of CaCl2 in methanol at T = (298.15 to 398.15) K, at pressures up to 40 MPa are reported, and apparent molar volumes have been evaluated. The experimental (p, ρ, T) values were described by an equation of state. The experiments were carried out at m = (0.10819, 0.28529, 0.65879 and 2.39344) mol . kg-1 of calcium chloride

  14. Excess Molar Volume and Apparent Molar Volume of Binary Mixtures of 2—Methyl—3—buten—2—ol with 1—Alcohol at 298.15K

    Institute of Scientific and Technical Information of China (English)

    LIUDixia; LIHaoran; 等

    2002-01-01

    Excess molar volumes (VmE) of binary mixtures of 2-methyl-3-buten-2-ol[CH3C(OH)(CH3)CHCH2] with four 1-alcohols:methanol,ethanol,1-propanol and 1-butanol at 298.15K and atmospheric pressure are derived from density measurements with a vibrating-tube densimeter.All the excess volumes are negative in the systems over the entire composition range. The results are correlated with the Redlich-Kister equation.The effects of chain length of 1-alcohols on VmE are discussed.The apparent molar volumes of 2-methyl-3-buten-2-ol and 1-alcohols are calculated respectively.

  15. Solubility and hydrolysis of aluminum oxides and hydroxides at elevated temperatures from apparent molar heat capacity and volume measurements near 25 degree C

    International Nuclear Information System (INIS)

    Most metal oxides are so insoluble under neutral or basic conditions that direct solubility measurements over wide ranges of pH and temperature are very difficult. Extrapolations of room temperature data to elevated temperatures and pressures require standard partial molar heat capacity and volume functions for the aqueous metal species and all of its hydroxy complexes. Aluminum is one of the few metals whose solubility in alkaline solutions is high enough to permit the heat capacity function of one of the anionic hydroxy complexes, Al(OH)4-(aq), to be measured directly by calorimetry. This paper summarizes recent measurements leading to the apparent molar heat capacities and volumes of AlCl3(aq), Al(NO3)3(aq) and NaAl(OH)4(aq) which have led to standard partial molar heat capacity and volume functions for Al+3(aq) and Al(OH)4-(aq), from 10 to 55 degree C. The results at 25 degree C differ from the Criss-Cobble Entropy Correspondence predictions by more than 130 J K-1 mol-1. Because Al3+(aq) and Al(OH)4-(aq) are the end members of the hydrolysis sequence for aluminum, the thermodynamic functions for the intermediate species can be estimated by interpolation. We have used the Helgeson-Kirkham-Flowers model to extrapolate the experimental heat capacity and volume functions of both end member ions upward in temperature to 300 degree C. Values for the intermediate species, AI(OH)m3-m, were estimated by linear interpolation of the non-Born terms in the model. The Gibbs energies of formation calculated from this approach lead to solubility products for boehmite which agree with experimental results up to 250 degree C over the entire pH range

  16. Assessment of treatment response by total tumor volume and global apparent diffusion coefficient using diffusion-weighted MRI in patients with metastatic bone disease: a feasibility study.

    Directory of Open Access Journals (Sweden)

    Matthew D Blackledge

    Full Text Available We describe our semi-automatic segmentation of whole-body diffusion-weighted MRI (WBDWI using a Markov random field (MRF model to derive tumor total diffusion volume (tDV and associated global apparent diffusion coefficient (gADC; and demonstrate the feasibility of using these indices for assessing tumor burden and response to treatment in patients with bone metastases. WBDWI was performed on eleven patients diagnosed with bone metastases from breast and prostate cancers before and after anti-cancer therapies. Semi-automatic segmentation incorporating a MRF model was performed in all patients below the C4 vertebra by an experienced radiologist with over eight years of clinical experience in body DWI. Changes in tDV and gADC distributions were compared with overall response determined by all imaging, tumor markers and clinical findings at serial follow up. The segmentation technique was possible in all patients although erroneous volumes of interest were generated in one patient because of poor fat suppression in the pelvis, requiring manual correction. Responding patients showed a larger increase in gADC (median change = +0.18, range = -0.07 to +0.78 × 10(-3 mm2/s after treatment compared to non-responding patients (median change = -0.02, range = -0.10 to +0.05 × 10(-3 mm2/s, p = 0.05, Mann-Whitney test, whereas non-responding patients showed a significantly larger increase in tDV (median change = +26%, range = +3 to +284% compared to responding patients (median change = -50%, range = -85 to +27%, p = 0.02, Mann-Whitney test. Semi-automatic segmentation of WBDWI is feasible for metastatic bone disease in this pilot cohort of 11 patients, and could be used to quantify tumor total diffusion volume and median global ADC for assessing response to treatment.

  17. High-pressure densities and derived volumetric properties (excess, apparent, and partial molar volumes) of binary mixtures of {methanol (1) + [BMIM][BF4] (2)}

    International Nuclear Information System (INIS)

    The density of seven {(0.0087, 0.0433, 0.1302, 0.2626, 0.4988, 0.7501, and 0.9102) mole fraction of [BMIM][BF4]} binary {methanol (1) + [BMIM][BF4] (2)} (1-butyl-3-methylimidazolium tetrafluoroborate) mixtures has been measured with a vibrating-tube densimeter. Measurements were performed at temperatures from (298 to 398) K and at pressures up to 40 MPa. The total uncertainties of density, temperature, pressure, and concentration measurements was estimated to be less than 0.15 kg . m-3, 15 mK, 5 kPa, and 10-4, respectively. The uncertainties reported in this paper are expanded uncertainties at the 95% confidence level with a coverage factor of k = 2. The effect of temperature, pressure, and concentration on the density and derived volumetric properties such as excess, apparent, and partial molar volumes was studied. The measured densities were used to develop a Tait-type equation of state for the mixture. The structural properties such as direct and total correlation function integrals and cluster size were calculated using the Krichevskii function concept and the equation of state for the mixture at infinite dilution

  18. Tumour apparent diffusion coefficient is associated with depth of myometrial invasion and is negatively correlated to tumour volume in endometrial carcinomas

    International Nuclear Information System (INIS)

    Aim: To explore possible correlations between tumour apparent diffusion coefficient (ADC), morphological tumour volume, and clinical and histological characteristics in endometrial carcinomas and to evaluate interobserver agreement for preoperative staging by MRI and for ADC measurements. Materials and methods: Preoperative conventional MRI including diffusion-weighted imaging (DWI) was performed in 105 endometrial carcinoma patients. Three radiologists independently reviewed the images for the presence of deep myometrial invasion, cervical stromal invasion, and lymph node metastases, and measured tumour ADC in regions of interest (ROIs). ADC values were analysed in relation to histomorphological characteristics and tumour volume. Kappa coefficients (κ) and intraclass correlation coefficients (ICC) for interobserver agreement for MRI staging results and ADC measurements, respectively, were calculated, and receiver operating characteristic (ROC) curves for identification of deep of myometrial invasion were generated. Results: Mean tumour ADC was significantly lower in tumours with deep myometrial invasion (ADC = 0.75 × 10−3 mm2/s) compared to tumours with superficial or no myometrial invasion (ADC = 0.85 × 10−3 mm2/s; p < 0.001). ADC was negatively correlated to tumour size (p = 0.007). The interobserver agreement was fair (κ = 0.32) for depth of myometrial invasion, good for cervical stromal invasion (κ = 0.66), and moderate for lymph node metastases (κ = 0.54), and the interobserver variability for ADC value measurements was low (ICC = 0.60). Conclusion: Tumour ADC measurements may in the future provide an adjunct tool, aiding in the preoperative identification of high-risk patients with deep myometrial infiltration. - Highlights: • Low tumour ADC is associated with deep myometrial invasion in endometrial carcinomas. • Tumour ADC value is negatively correlated to tumour size. • Preoperative staging by MRI is prone to

  19. Partial molar volume of paracetamol in water, 0.1 M HCl and 0.154 M NaCl at T = (298.15, 303.15, 308.15 and 310.65) K and at 101.325 kPa

    International Nuclear Information System (INIS)

    The apparent molar volume of paracetamol (4-acetamidophenol) in water, 0.1 M HCl and 0.154 M NaCl as solvents at (298.15, 303.15, 308.15 and 310.65) K temperatures and at a pressure of 101.325 kPa were determined from the density data obtained with the help of a vibrating-tube Anton Paar DMA-48 densimeter. The partial molar volume, V m, of paracetamol in these solvents at different temperatures was evaluated by extrapolating the apparent molar volume versus molality plots to m = 0. In addition, the partial molar expansivity, E ., the isobaric coefficient of thermal expansion, α p, and the interaction coefficient, S v, have also been computed. The expansivity data show dependence of E . values on the structure of the solute molecules

  20. Partial molar volume of paracetamol in water, 0.1 M HCl and 0.154 M NaCl at T = (298.15, 303.15, 308.15 and 310.65) K and at 101.325 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Muhammad Javed [Department of Chemistry, Quaid-i-Azam University, Islamabad, Capital 54320 (Pakistan)]. E-mail: mjiqauchem@yahoo.com; Malik, Qaisar Mahmood [Department of Chemistry, Quaid-i-Azam University, Islamabad, Capital 54320 (Pakistan)]. E-mail: qaisar_@hotmail.com

    2005-12-15

    The apparent molar volume of paracetamol (4-acetamidophenol) in water, 0.1 M HCl and 0.154 M NaCl as solvents at (298.15, 303.15, 308.15 and 310.65) K temperatures and at a pressure of 101.325 kPa were determined from the density data obtained with the help of a vibrating-tube Anton Paar DMA-48 densimeter. The partial molar volume, V {sub m}, of paracetamol in these solvents at different temperatures was evaluated by extrapolating the apparent molar volume versus molality plots to m = 0. In addition, the partial molar expansivity, E {sup .}, the isobaric coefficient of thermal expansion, {alpha} {sub p}, and the interaction coefficient, S {sub v}, have also been computed. The expansivity data show dependence of E {sup .} values on the structure of the solute molecules.

  1. Apparent molar volumes and isentropic compressibilities of benzyltrialkylammonium chlorides in water at (293.15, 303.15, 313.15, 323.15, and 333.15) K

    International Nuclear Information System (INIS)

    Densities and ultrasound speeds of benzyltrialkylammonium chlorides (BTAACls) were measured accurately in aqueous solutions at five temperatures (293.15, 303.15, 313.15, 323.15, and 333.15) K. The data were utilized in determining apparent molar volumes, VΦ, and apparent molar isentropic compressibilities, KSΦ. Infinite dilution values of these apparent molar quantities, VΦ0andKSΦ0, were determined by extrapolation procedures. Contribution of CH2 groups, along the alkyl groups of BTAACls, to VΦ0andKSΦ0 values were derived from plots of these quantities as a function of number of additional CH2 groups in going from benzyltrimethylammonium chloride to benzyltributylammonium chloride. The temperature dependencies of VΦ0andKSΦ0 values were examined on the basis of isobaric expansivity. Apparent molar isobaric expansivities at infinite dilution, EΦ0, were obtained from the slopes of VΦ0versus temperature data. Concentration dependencies of VΦ and KSΦ were examined. A fair correlation was observed between VΦ0andKSΦ0 values of the three BTAACls.

  2. Hyperpolarized 3He apparent diffusion coefficient MRI of the lung: reproducibility and volume dependency in healthy volunteers and patients with emphysema

    DEFF Research Database (Denmark)

    Diaz, S.; Casselbrant, I.; Piitulainen, E.; Pettersson, G.; Magnusson, Stig Peter; Peterson, B.; Wollmer, P.; Leander, P.; Ekberg, O.; Åkeson, Per Arne Gustav; Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva; Pettersson, Goran; Magnusson, Peter; Peterson, Barry; Wollmer, Per; Leander, Peter; Ekberg, Olle; Akeson, Per

    2008-01-01

    -day period and received two different volumes (6% and 15% of total lung capacity [TLC]) of HP (3)He each day. ADC maps and histograms were calculated. The mean and standard deviation (SD) of the ADC at different days and volumes were compared. RESULTS: The reproducibility of the mean ADC and SD over several...... days was good in both healthy volunteers and patients (SD range of 0.003-0.013 cm(2)/second and 0.001-0.009 cm(2)/second at 6% and 15% of TLC for healthy volunteers, and a SD range of 0.001-0.041 cm(2)/second and 0.001-0.011 cm(2)/second, respectively, for patients). A minor but significant increase in...

  3. Subtleties in the calculation of the pressure and pressure tensor of anisotropic particles from volume-perturbation methods and the apparent asymmetry of the compressive and expansive contributions

    OpenAIRE

    Brumby, Paul E; Haslam, Andrew J.; de Miguel, Enrique; Jackson, George

    2010-01-01

    Abstract An effcient and versatile method to calculate the components of the pressure tensor for hard-body fluids of generic shape from the perspective of molecular simulation is presented. After due consideration of all the possible repulsive contributions exerted by molecules upon their surroundings during an anisotropic system expansion, it is observed that such a volume changevcan, for non-spherical molecules, give rise to configurations where overlaps occur. This feature of an...

  4. Measurement and COrrelation on Viscosity and Apparent Molar Volume of Ternary System for L—ascorbic Acid in Aqueous D—Glucose and Sucrose Solutions

    Institute of Scientific and Technical Information of China (English)

    赵长伟; 马沛生

    2003-01-01

    Visosities and densities at ,several temperatures from 293.15 K to 313.15K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations.The parameters of density,Viscosity coefficient B and partial molar volume are calculated by regression.The experimental results show that densities and viscositis decrease as temperature increases at the same solute and solvent (glucose and sucrose aueous solution)concentrations,and increase with concentration of glucose and sucrose at the same solute concentration and temperature,B increases with concentration of glucose and sucrose and temaperature,L-ascorbic acid is sturcture-breaker or structure-making for the glucose and sucrose aqueous solutions ,Furthermore,the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

  5. Apparent molar volumes and apparent molar heat capacities of aqueous N-acetyl-D-glucosamine at temperatures from 278.15 K to 368.15 K and of aqueous N-methylacetamide at temperatures from 278.15 K to 393.15 K at the pressure 0.35 MPa

    International Nuclear Information System (INIS)

    We determined apparent molar volumes V φ from densities measured with a vibrating-tube densimeter at 278.15 ≤ (T/K) ≤ 368.15 and apparent molar heat capacities C p,φ with a twin fixed-cell, differential, temperature-scanning calorimeter at 278.15 ≤ (T/K) ≤ 363.15 for aqueous solutions of N-acetyl-D-glucosamine at m from (0.01 to 1.0) mol . kg-1 and at p = 0.35 MPa. We also determined V φ at 278.15 ≤ (T/K) ≤ 368.15 and C p,φ at 278.15 ≤ (T/K) ≤ 393.15 for aqueous solutions of N-methylacetamide at m from (0.015 to 1.0) mol . kg-1 and at p = 0.35 MPa. Empirical functions of m and T for each compound were fitted to our results, which are then compared to those for N,N-dimethylacetamide. Estimated values of Δr V m(m, T) and Δr C p,m(m, T) for formation of aqueous N-acetyl-D-glucosamine from aqueous D-glucose and aqueous acetamide are calculated and discussed

  6. Partial molar volume and isentropic compressibility of symmetrical and asymmetrical quaternary ammonium bromides in aqueous solution

    International Nuclear Information System (INIS)

    Highlights: • Structural effects of the cations on surrounding water molecules are discussed. • Alkyl-chain geometry determines the hydration of Bu4N+ isomers. • The “compactness” in the hydration shells varies significantly among the isomers. - Abstract: Values of apparent molar volume and isentropic compressibility of symmetric and asymmetric isomers of tetrabutylammonium bromide, namely tetra-n-butylammonium bromide, tetra-iso-butylammonium bromide, tetra-sec-butylammonium bromide, di-n-butyl-di-iso-butylammonium bromide and di-n-butyl-di-sec-butylammonium bromide, in aqueous solution were determined from density and speed of sound measurements. These properties were obtained as a function of molal concentration within the range of 0.01 < m/mol · kg−1 < 0.1 covering temperatures from 278.15 ⩽ T/K ⩽ 293.15. The partial molar volumes and the apparent isentropic molar compressibility at infinite dilution were calculated and their dependence on temperature examined. The results show that cations with sec-butyl chains have larger structural volumes compared to those with iso-butyl chains. In addition, cations with sec-butyl chains induce smaller structural changes in their hydration shell than the others

  7. Molecular interaction studies of glycylglycine in aqueous sodium halide solutions at 303, 308 and 313k

    Directory of Open Access Journals (Sweden)

    R. Palani

    2010-12-01

    Full Text Available Ultrasonic velocity, density and viscosity have been measured for glycylglycine in aqueous sodium halide (NaF, NaCl, NaBr mixture (0.5m at 303, 308 and 313K. Using the experimental values, the adiabatic compressibility, hydration number, apparent molal compressibility, apparent molal volume, limiting apparent molal compressibility, limiting apparent molal volume and their constants (SK, SV, transfer volumes at infinite dilution and viscosity B-coefficient of Jones-Dole equation were calculated. These parameters have been interpreted the molecular interactions in terms of solute-co-solute and solute-solvent interaction present in the given solutions.

  8. Relation of Plasma Lipoprotein(a) to Subclinical Coronary Plaque Volumes, Three-Vessel and Left Main Coronary Disease, and Severe Coronary Stenoses in Apparently Healthy African-Americans With a Family History of Early-Onset Coronary Artery Disease.

    Science.gov (United States)

    Kral, Brian G; Kalyani, Rita R; Yanek, Lisa R; Vaidya, Dhananjay; Fishman, Elliot K; Becker, Diane M; Becker, Lewis C

    2016-09-01

    Serum lipoprotein(a) [Lp(a)] is a coronary artery disease (CAD) risk factor in persons of European ancestry. Levels are twofold to threefold higher in African-Americans (AAs), but reported associations with CAD have been inconsistent. The relation of Lp(a) with the extent and severity of subclinical coronary plaque has not been described in AAs. We screened 269 apparently healthy AAs for risk factors and coronary plaque using advanced coronary computed tomographic angiography. Total coronary plaque (TCP), noncalcified coronary plaque, and calcified coronary plaque volumes (mm(3)) were quantified using a validated automated method. Lp(a) was measured by ELISA. Multivariable modeling was performed with adjustment for traditional CAD risk factors and intrafamilial correlations. Mean age was 51 ± 11 years and 64% were female. Plaque was present in 41%. Lp(a) was independently associated with TCP volume [log(TCP + 1)] (p = 0.04), 3-vessel and/or left main involvement (p = 0.04), and at least 1 stenosis >50% (p = 0.006). Best-fit regression analyses showed that subjects with Lp(a) >40 mg/dl were threefold more likely to have 3-vessel and/or left main disease (95% confidence interval 1.4 to 6.8, p = 0.005) and fourfold more likely to have stenosis >50% (95% confidence interval 1.3 to 15.0, p = 0.02). In subjects with plaque (n = 110), multivariable models showed the Lp(a) level was significantly and independently associated with TCP (p = 0.009), noncalcified coronary plaque (p = 0.01), and calcified coronary plaque (p = 0.003) and affected vessel length (p = 0.01). In conclusion, high Lp(a) is strongly associated with coronary plaque volumes, extent, and severity in apparently healthy AAs. High levels of Lp(a) may be particularly important in the pathogenesis of CAD in AAs. PMID:27530333

  9. Thermodynamic Phase And Chemical Equilibrium At 0-110 C For The H+-K+-Na+-Cl--H2O System Up To 16 Molal And The HNO3-H2O System Up To 20 Molal Using An Association-Based Pitzer Model Compatible With ASPEN Plus

    Energy Technology Data Exchange (ETDEWEB)

    Nichols,T.T.; Taylor,D.D.

    2003-09-26

    A status is presented of the parameterization during FY2003 of an association-based Pitzer model to simulate chemical and phase equilibria of acid-chloride-nitrate-mercury aqueous electrolyte systems at 0-100 C within the industry-standard process simulator, ASPEN Plus. Compatibility with ASPEN Plus requires that the Pitzer model used be limited to the third virial coefficient and have the values of b and a1 as originally proposed by Pitzer. Two aqueous models for 0-110 C at atmospheric pressure were parameterized in FY03. The model for the aqueous H+-K+-Na+-Cl- system is applicable for 0-16 molal, and the HNO3-H2O for 0-20 molal. An association-based Pitzer activity coefficient model is combined with Henry's law to predict activity/osmotic coefficient and VLE. The chloride model also predicts KCl and NaCl solubility, while the nitric acid model has the unique capability of predicting extent of dissociation with an average absolute deviation of 1.43%. The association-based approach presented here extends the utility of the molality-based Pitzer model past 6 molal to predict activity/osmotic coefficients up to 16-20 molal. The association-based approach offers the additional benefits of predicting extent of dissociation and of allowing the Pitzer model to be fully utilized in commercial simulators, such as ASPEN Plus, that require accounting for association to implement Henry's law. The Pitzer models presented here provide the chemical process simulation engineer with a superior alternative to the Electrolyte NRTL model that can easily be used in ASPEN Plus.

  10. Remembering apparent behavior

    DEFF Research Database (Denmark)

    Wagoner, Brady

    2011-01-01

    The present experiment systematically investigates the role of narrative templates (Wertsch, 2002) in remembering. To stimulate the construction of a diversity of narratives I used Heider and Simmel’s (1944) celebrated “apparent behavior” film, in which geometric shapes moving around a screen are...

  11. Apparent Superluminal Behavior

    CERN Document Server

    Jackson, A D; Lautrup, B

    2000-01-01

    The apparent superluminal propagation of electromagnetic signals seen in recent experiments is shown to be the result of simple and robust properties of relativistic field equations. Although the wave front of a signal passing through a classically forbidden region can never move faster than light, an attenuated replica of the signal is reproduced ``instantaneously'' on the other side of the barrier. The reconstructed signal, causally connected to the forerunner rather than the bulk of the input signal, appears to move through the barrier faster than light.

  12. Dependences of molar volumes in solids, partial molal and hydrated ionic volumes of alkali halides on covalent and ionic radii and the golden ratio

    Czech Academy of Sciences Publication Activity Database

    Heyrovská, Raji

    2007-01-01

    Roč. 436, č. 1-3 (2007), s. 287-293. ISSN 0009-2614 R&D Projects: GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040702 Keywords : alkali halides * ionic hydration * golden ratio Subject RIV: BO - Biophysics Impact factor: 2.207, year: 2007

  13. The apparent Universe

    Science.gov (United States)

    Binétruy, P.; Helou, A.

    2015-10-01

    We exploit the parallel between dynamical black holes and cosmological spacetimes to describe the evolution of Friedmann-Lemaître-Robertson-Walker universes from the point of view of an observer in terms of the dynamics of the apparent horizon. Using the Hayward-Kodama formalism of dynamical black holes, we clarify the role of the Clausius relation to derive the Friedmann equations for a Universe, in the spirit of Jacobson’s work on the thermodynamics of spacetime. We also show how dynamics at the horizon naturally leads to the quantum-mechanical process of Hawking radiation. We comment on the connection of this work with recent ideas to consider our observable Universe as a Bose-Einstein condensate and on the corresponding role of vacuum energy.

  14. Apparent capitellar fractures.

    Science.gov (United States)

    Ring, David

    2007-11-01

    Isolated capitellar fractures are rare but are identified as such, even when they are more complex, because the displaced capitellar fracture is usually the most obvious and identifiable radiographic finding and because teaching has traditionally underemphasized the involvement of the trochlea in such fractures. The author prefers the term 'apparent capitellar fractures' and draws on his experience to explain why he favors three-dimensional CT for depicting fracture detail. This article discusses treatment options, emphasizing open reduction and internal fixation to restore the native elbow. Operative techniques, including extensile lateral exposure and olecranon osteotomy; fixation techniques; and elbow arthroplasty, are described. Complications, such as ulnar neuropathy and infection, are also covered. PMID:18054674

  15. Effects of structural isomerism on solution behaviour of solutes: Apparent molar volumes and isentropic compression of catechol, resorcinal, and hydroquinone in aqueous solution at T = (283.15, 293.15, 298.15, 303.15, and 313.15) K

    International Nuclear Information System (INIS)

    Effects of structural isomerism on solution behaviour of dihydroxybenzenes were examined through the determination of volumetric properties such as apparent molar volumes, apparent molar isentropic compressions, and isobaric expansions. The isomers were 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene (resorcinol), and 1,4-dihydroxybenzene (hydroquinone). The volumetric properties were determined from accurate density and speed of sound measurements at T = (283.15, 293.15, 298.15, 303.15, and 313.15) K and at various concentrations. Values at infinite dilution of these parameters were obtained by suitable extrapolation procedures. The results are discussed in terms of hydrophobic, hydrogen bonding, and dipole-dipole interactions between the three isomers and water. Catechol was found to have the strongest hydrophilic and the weakest hydrophobic interactions with water among the three isomers.

  16. Effects of structural isomerism on solution behaviour of solutes: Apparent molar volumes and isentropic compression of catechol, resorcinal, and hydroquinone in aqueous solution at T = (283.15, 293.15, 298.15, 303.15, and 313.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Bayram, Edip [Department of Chemistry, Akdeniz University, Antalya 07058 (Turkey); Ayranci, Erol, E-mail: eayranci@akdeniz.edu.t [Department of Chemistry, Akdeniz University, Antalya 07058 (Turkey)

    2010-09-15

    Effects of structural isomerism on solution behaviour of dihydroxybenzenes were examined through the determination of volumetric properties such as apparent molar volumes, apparent molar isentropic compressions, and isobaric expansions. The isomers were 1,2-dihydroxybenzene (catechol), 1,3-dihydroxybenzene (resorcinol), and 1,4-dihydroxybenzene (hydroquinone). The volumetric properties were determined from accurate density and speed of sound measurements at T = (283.15, 293.15, 298.15, 303.15, and 313.15) K and at various concentrations. Values at infinite dilution of these parameters were obtained by suitable extrapolation procedures. The results are discussed in terms of hydrophobic, hydrogen bonding, and dipole-dipole interactions between the three isomers and water. Catechol was found to have the strongest hydrophilic and the weakest hydrophobic interactions with water among the three isomers.

  17. Apparent Clustering and Apparent Background Earthquakes Biased by Undetected Seismicity

    CERN Document Server

    Sornette, D

    2005-01-01

    In models of triggered seismicity and in their inversion with empirical data, the detection threshold m_d is commonly equated to the magnitude m_0 of the smallest triggering earthquake. This unjustified assumption neglects the possibility of shocks below the detection threshold triggering observable events. We introduce a formalism that distinguishes between the detection threshold m_d and the minimum triggering earthquake m_0 < m_d. By considering the branching structure of one complete cascade of triggered events, we derive the apparent branching ratio n_a (which is the apparent fraction of aftershocks in a given catalog) and the apparent background source S_a that are observed when only the structure above the detection threshold m_d is known due to the presence of smaller undetected events that are capable of triggering larger events. If earthquake triggering is controlled in large part by the smallest magnitudes as several recent analyses have shown, this implies that previous estimates of the cluster...

  18. Molecular dynamics simulation study of ionic hydration and ion association in dilute and 1 molal aqueous sodium chloride solutions from ambient to supercritical conditions

    Science.gov (United States)

    Driesner, T.; Seward, T. M.; Tironi, I. G.

    1998-09-01

    The increasing demand for accurate equations of state of fluids under extreme conditions and the need for a detailed microscopic picture of aqueous fluids in some areas of geochemistry (e.g., mineral dissolution/precipitation kinetics) potentially make molecular dynamics (MD) simulations a powerful tool for theoretical geochemistry. We present MD simulations of infinitely dilute and 1 molal aqueous NaCl solutions that have been carried out in order to study the systematics of hydration and ion association over a wide range of conditions from ambient to supercritical and compare them to the available experimental data. In the dilute case, the hydration number of the Na + ion remains essentially constant around 5.5 from ambient to supercritical temperatures when the density is kept constant at 1 g cm -3 but decreases to below 5 along the liquid-vapor curve. In both cases, the average ion-first shell water distance decreases by about 0.03 Å from ambient to near critical temperatures. The Cl - ion shows a slight expansion of the first hydration shell by about 0.02 Å from ambient to near critical temperatures. The geometric definition of the first hydration shell becomes ambiguous due to a shift of the position of the first minimum of the Cl-O radial distribution function. In the case of the 1 molal solution, the contraction of the Na + first hydration shell is similar to that in the dilute case whereas the hydration number decreases drastically from 4.9 to 2.8 due to strong ion association. The released waters are replaced on a near 1:1 basis by chloride ions. Polynuclear clusters as predicted by Oelkers and Helgeson (1993b) are observed in the high temperature systems. The hydration shell of the Cl --ion shows significant deviation from the behavior in dilute systems, that is, at near vapor saturated conditions, the expansion of the hydration shell is significantly larger (0.12 Å from ambient to near critical temperatures). Due to a very large shift of the first

  19. Vapor pressures and isopiestic molalities of concentrated CaCl2(aq), CaBr2(aq), and NaCl(aq) to T = 523 K

    International Nuclear Information System (INIS)

    The Oak Ridge National Laboratory high-temperature isopiestic apparatus was outfitted with precise pressure gauges to allow for direct vapor pressure measurements. Vapor pressures over concentrated solutions of CaCl2(aq), and CaBr2(aq) were measured at temperatures between (380.15 and 523.15) K in the range of water activities between 0.2 and 0.85. Isopiestic molalities were used to determine osmotic coefficients at the conditions where NaCl reference standard solutions remained undersaturated. The main goal of this work was to improve the accuracy of isopiestic comparisons based on the calcium chloride reference standard. Osmotic coefficients for CaCl2(aq) and CaBr2(aq) calculated from both isopiestic and direct vapor pressure results were combined with the literature data and used to build general thermodynamic models based on a variant of extended Pitzer ion-interaction equations and valid at the saturation pressure of water. While these empirical models approach the accuracy of the experimental data in a wider range of concentrations and temperatures than any previously published equations, considerable amounts of accurate data and a substantial effort are required in order to obtain a satisfactory representation using power series-based virial equations. The effect of experimental uncertainties on the accuracy of the direct vapor pressure results is discussed, including in particular the error caused by the presence in the apparatus of a small amount of CO2. The substantial decrease of the solubility product of CaCO3 in concentrated chloride solutions at temperatures above 423 K is a serious defect of calcium chloride as a water activity reference standard

  20. Apparent Solar Tornado - Like Prominences

    CERN Document Server

    Panasenco, Olga; Velli, Marco

    2013-01-01

    Recent high-resolution observations from the Solar Dynamics Observatory (SDO) have reawakened interest in the old and fascinating phenomenon of solar tornado-like prominences. This class of prominences was first introduced by Pettit (1932), who studied them over many years. Observations of tornado prominences similar to the ones seen by SDO had already been documented by Secchi (1877) in his famous "Le Soleil". High resolution and high cadence multiwavelength data obtained by SDO reveal that the tornado-like appearance of these prominences is mainly an illusion due to projection effects. We discuss two different cases where prominences on the limb might appear to have a tornado-like behavior. One case of apparent vortical motions in prominence spines and barbs arises from the (mostly) 2D counterstreaming plasma motion along the prominence spine and barbs together with oscillations along individual threads. The other case of apparent rotational motion is observed in prominence cavities and results from the 3D ...

  1. Wormhole Thermodynamics at Apparent Horizons

    OpenAIRE

    Jamil, Mubasher; Akbar, M

    2009-01-01

    In this paper, we discuss the thermodynamic properties of the evolving Lorentzian wormhole. For the shape function $b(r) = r_{0}^2/r$, it is shown that the wormhole spacetime admits two apparent horizons, the inner and the outer one. The inner horizon expands while the outer contracts with the passage of time. Corresponding to these horizons, we have three types of wormholes, regular, extreme and the naked wormholes. Moreover, it is shown that the Einstein field equations can be rewritten as ...

  2. The densities of halite-saturated WIPP-A and NBT-6 brines and their NaCl contents in weight percent, molal, and molar units from 20 to 100 degrees C

    Science.gov (United States)

    Chou, I-Ming; Buizinga, B.; Clynne, M.A.; Potter, R.W.

    1982-01-01

    A series of density measurements has been performed at 30?, 50?, 70?, and 90?C for halite-undersaturated WIPP-A and NBT-6 brines with various NaCl contents approaching saturation. The densities of halite-saturated WIPP-A and NBT-6 brines were obtained by extrapolating these measured densities to halite saturation points. The maximum difference between the densities obtained in this Fashion and those calculated from the model of Potter and Haas is 0.015 g/cm3. The NaCl contents in halite-saturated WIPP-A and NBT-6 brines are reported in wt %, molal, and molar units from 20? to 100?C.

  3. Apparent diffusion coefficient of hippocampus in patients with hippocampal sclerosis: Correlation with the volume and MRS of hippocampus%海马硬化患者海马ADC值与海马体积及磁共振波谱的相关性

    Institute of Scientific and Technical Information of China (English)

    张泉; 张云亭; 冯凯琳; 张敬; 张权

    2011-01-01

    Objective To investigate the correlation of apparent diffusion coefficient (ADC) value of hippocampus with the volume and magnetic resonance spectroscopy (MRS) of hippocampus in patients with hippocampal sclerosis (HS), and to evaluate the diagnostic value of ADC value. Methods Thirteen HS patients (HS group) of unilateral temporal lobe epilepsy (TLE) and 20 age-matched healthy subjects (control group) were studied with hippocampal ADC maps, volume measurement of hippocampus and N-acetylaspartate to choline and creatine ratios [NAA/(Cho+Cr)]. The ADC values of bilateral hippocampi and asymmetry index (AI, including AIADC, AIVOLUME and AIMRS) were measured respectively, and the correlations of ADC value with other quantitative MR measurements, age at onset and duration of epilepsy were evaluated.Results The ADC value in ipsilateral hippocampus was higher than that in contralateral side and the control group (both P <0. 001 ), and AIADC in patients with HS was also higher than that in the control group (P<0. 001). Significant correlations were found between ADC value and the volume of ipsilateral hippocampus (r=-0.854, P<0. 001), also between AIADC and AIVPLUME (r=0. 611, P<0. 05). AIADC showed positive correlation with the duration of epilepsy in HS patients (r=0. 676, P<0. 05). Conclusion The ADC value of hippocampus is helpful for the preoperative diagnosis of HS and has certain correlation with volume measurement and duration of epilepsy.%目的 探讨海马硬化(HS)患者的海马表观扩散系数(ADC)值与海马体积及磁共振波谱的相关性,并评价ADC值在HS诊断中的价值.方法 对13例单侧颞叶癫痫HS患者(HS组)和20名健康志愿者(正常对照组)行常规MR及磁共振扩散加权成像(DWI)检查,并对HS患者进行海马体积测量和磁共振波谱(MRS)检查,计算双侧海马的ADC值、标准化体积、N-乙酰天门冬氨酸/(胆碱+肌酸)[NAA/(Cho+Cr)]及不对称指数(AI,包括AIADC、AIVOLUME及AIMRS),评

  4. Distribution of apparent stress in western China

    Institute of Scientific and Technical Information of China (English)

    吴忠良; 黄静; 林碧苍

    2002-01-01

    Distribution of apparent stress in Chinese mainland and its surrounding regions was presented using the NEIC broadband radiated energy catalogue and the Harvard CMT catalogue from January 1987 to December 1998. Due to the limitation on the number of samples, reliable results are only for the western China. It is observed that the average apparent stress in Chinese mainland is 0.8 MPa; The maximum apparent stress to the east of the Tibetan plateau is 2.6 MPa; And the average apparent stress in the north-south seismic belt is more than one time higher than its adjacent regions. Distribution pattern of apparent stress seems to have a large-scale correlation with the cumulative energy release level in the 20th century.

  5. Wilcox Group Apparent Thickness, Gulf Coast (wlcxthkg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Apparent Wilcox Group thickness maps are contoured from location and top information derived from the Petroleum Information (PI) Wells database. The Wilcox...

  6. Viscous Cosmology and Thermodynamics of Apparent Horizon

    OpenAIRE

    Akbar, M.

    2008-01-01

    It is shown that the differential form of Friedmann equations of FRW universe can be recast as a similar form of the first law, $T_{h}dS_{h} = dE + WdV$, of thermodynamics at the apparent horizon of FRW universe filled with the viscous fluid. It is also shown that the generalized second law of thermodynamics holds at the apparent horizon of FRW universe and preserves dominant energy condition.

  7. Traceable mean activity coefficients and osmotic coefficients in aqueous magnesium chloride solutions at T = 298.15 K up to a molality of 3.0 mol · kg−1

    International Nuclear Information System (INIS)

    Highlights: • This work reports new equations for thermodynamic activity quantities in aqueous MgCl2 solutions. • The new equations are functionally the same as those obtained previously solutions of CaCl2 and uni-univalent electrolytes. • The new activity and osmotic coefficients are fully traceable and transparent. • These new values were tested thoroughly with existing literature data. -- Abstract: The Hückel equation used in this study for the thermodynamic activity quantities in dilute MgCl2 solutions up to an ionic strength (=Im) of 1.5 mol · kg−1 contains two parameters being dependent on the electrolyte, i.e., those of B and b1. The former is linearly related to the ion-size parameter in the Debye–Hückel equation and the latter is the coefficient of the linear correction term with respect to the molality. For more concentrated solutions up to Im of 9.0 mol · kg−1, an extended Hückel equation was used. For it, the Hückel equation was extended with a quadratic term in molality, and the coefficient of this term is the third parameter b2. Parameters B and b1 for dilute MgCl2 solutions were obtained from the isopiestic data of Robinson and Stokes for solutions of this salt and KCl [Trans. Faraday Soc. 36 (1940) 733] by using the previous Hückel parameters for dilute KCl solutions [J. Chem. Eng. Data 54 (2009) 208]. The resulting parameters for MgCl2 solutions were successfully tested with all isopiestic data available in the literature for dilute solutions of this salt. For less dilute solutions, new values for parameters b1 and b2 were determined for the extended version of the Hückel equation of MgCl2 solutions from the isopiestic data of Rard and Miller [J. Chem. Eng. Data 26 (1981) 38] for NaCl and MgCl2 solutions but the dilute-solution value for parameter B was used. The previous extended Hückel equation for concentrated NaCl solutions was used in this estimation (see the KCl citation above). In the tests of the new parameter values

  8. Viscous Cosmology and Thermodynamics of Apparent Horizon

    Institute of Scientific and Technical Information of China (English)

    M. Akbar

    2008-01-01

    @@ It is shown that the differential form of Friedmann equations of Friedman-Robertson-Walker (FRW) universe can be recast as a similar form of the first law ThdSh=dE + W dV of thermodynamics at the apparent horizon of FRW universe filled with the viscous fluid.It is also shown that by employing the general expression of temperature Th=|k|/2π=1/2π(r)A(1-(r)A/2H(r)A) associated with the apparent horizon of an FRW universe and assumed that the temperature Tm of the energy inside the apparent horizon is proportional to the horizon temperature Tm = bTh,we are able to show that the generalized second law of thermodynamics holds in the Einstein gravity provided Th-Tm/(r)A≤(p+(P)).

  9. Superluminal apparent motions in distant radio sources

    CERN Document Server

    Chodorowski, Michal

    2004-01-01

    In this brief and pedagogical note, I derive a prediction of the standard model of superluminal radio sources for the apparent transverse velocity of a radio source located at a redshift z. The apparent velocity is reduced by a factor 1 + z, compared to that of a similar nearby source. The cause of this reduction is the recession velocity of the distant source. The apparent velocity of a source can be estimated from its redshift and proper motion, given the values of the Hubble constant and the mean densities of different energy components in the Universe. I provide a formula for the velocity valid for the currently favoured cosmological model: a flat universe with a non-zero cosmological constant.

  10. Application of BP neural network to semi-solid apparent viscosity simulation

    Institute of Scientific and Technical Information of China (English)

    罗中华; 张质良

    2003-01-01

    Two-layer BP neural network was designed for the semi-solid apparent viscosity simulation. The apparent viscosity simulations of Sn-15%Pb alloy and Al-4.5%Cu-1.5%Mg alloy stirred slurries were carried out. The trained BP neural network forecast the curve of the apparent viscosity versus solid volume fraction of Sn-15%Pb alloy, under the condition of shear rate, =150 s-1, and cooling rate of G=0.33 ℃/min. The simulation results are well agreement with the experimental values given in references The fitted mathematical formula of Sn-15%Pb alloy apparent viscosity, under the condition of the cooling rate of G=0.33 ℃/min, was obtained by optimization method. The results show that the precision of apparent viscosity simulation value by neural network is much better than that of its calculation value by fitted mathematical formula.

  11. Apparent Directional Scanning for DNA Repair

    OpenAIRE

    Zhao, Tong; Dinner, Aaron R.

    2007-01-01

    Recently it was observed that the DNA repair protein human O6-alkylguanine-DNA alkyltransferase repairs lesions at the 5′ ends of 70-nucleotide single-stranded DNA roughly threefold more frequently than lesions at the 3′ ends. Here, we introduce a coarse-grained model to show how a local asymmetry in binding kinetics (rather than thermodynamics) together with irreversible alkyl transfer can give rise to this apparent bias in sequence scanning. Exploration of the parameter space provides quant...

  12. Rotational Vicometry under Apparent Wall Slip

    Czech Academy of Sciences Publication Activity Database

    Večeř, M.; Wein, Ondřej

    Bratislava: Slovak Society of Chemical Engineering, 2011 - (Markoš, J.), s. 90 ISBN 978-80-227-3503-2. [International Conference of Slovak Society of Chemical Engineering /38./. Tatranské Matliare (SK), 23.05.2011-27.05.2011] R&D Projects: GA ČR GA104/09/0972 Institutional research plan: CEZ:AV0Z40720504 Keywords : rotational viscometry * polymer solution * apparent wall slip Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  13. Apparent Solar Tornado-Like Prominences

    Science.gov (United States)

    Panasenco, Olga; Martin, Sara F.; Velli, Marco

    2014-02-01

    Recent high-resolution observations from the Solar Dynamics Observatory (SDO) have reawakened interest in the old and fascinating phenomenon of solar tornado-like prominences. This class of prominences was first introduced by Pettit ( Astrophys. J. 76, 9, 1932), who studied them over many years. Observations of tornado prominences similar to the ones seen by SDO had already been documented by Secchi ( Le Soleil, 1877). High-resolution and high-cadence multiwavelength data obtained by SDO reveal that the tornado-like appearance of these prominences is mainly an illusion due to projection effects. We discuss two different cases where prominences on the limb might appear to have a tornado-like behavior. One case of apparent vortical motions in prominence spines and barbs arises from the (mostly) 2D counterstreaming plasma motion along the prominence spine and barbs together with oscillations along individual threads. The other case of apparent rotational motion is observed in a prominence cavity and results from the 3D plasma motion along the writhed magnetic fields inside and along the prominence cavity as seen projected on the limb. Thus, the "tornado" impression results either from counterstreaming and oscillations or from the projection on the plane of the sky of plasma motion along magnetic-field lines, rather than from a true vortical motion around an (apparent) vertical or horizontal axis. We discuss the link between tornado-like prominences, filament barbs, and photospheric vortices at their base.

  14. Gravitational energy as dark energy: Cosmic structure and apparent acceleration

    CERN Document Server

    Wiltshire, David L

    2011-01-01

    Below scales of about 100/h Mpc our universe displays a complex inhomogeneous structure dominated by voids, with clusters of galaxies in sheets and filaments. The coincidence that cosmic expansion appears to start accelerating at the epoch when such structures form has prompted a number of researchers to question whether dark energy is a signature of a failure of the standard cosmology to properly account, on average, for the distribution of matter we observe. Here I discuss the timescape scenario, in which cosmic acceleration is understood as an apparent effect, due to gravitational energy gradients that grow when spatial curvature gradients become significant with the nonlinear growth of cosmic structure. I discuss conceptual issues related to the averaging problem, and their impact on the calibration of local geometry to the solutions of the volume-average evolution equations corrected by backreaction, and the question of nonbaryonic dark matter in the timescape framework. I further discuss recent work on ...

  15. Apparent magnitude of earthshine: a simple calculation

    Science.gov (United States)

    Agrawal, Dulli Chandra

    2016-05-01

    The Sun illuminates both the Moon and the Earth with practically the same luminous fluxes which are in turn reflected by them. The Moon provides a dim light to the Earth whereas the Earth illuminates the Moon with somewhat brighter light which can be seen from the Earth and is called earthshine. As the amount of light reflected from the Earth depends on part of the Earth and the cloud cover, the strength of earthshine varies throughout the year. The measure of the earthshine light is luminance, which is defined in photometry as the total luminous flux of light hitting or passing through a surface. The expression for the earthshine light in terms of the apparent magnitude has been derived for the first time and evaluated for two extreme cases; firstly, when the Sun’s rays are reflected by the water of the oceans and secondly when the reflector is either thick clouds or snow. The corresponding values are -1.30 and -3.69, respectively. The earthshine value -3.22 reported by Jackson lies within these apparent magnitudes. This paper will motivate the students and teachers of physics to look for the illuminated Moon by earthlight during the waning or waxing crescent phase of the Moon and to reproduce the expressions derived here by making use of the inverse-square law of radiation, Planck’s expression for the power in electromagnetic radiation, photopic spectral luminous efficiency function and expression for the apparent magnitude of a body in terms of luminous fluxes.

  16. Apparent exchange rate imaging in anisotropic systems

    DEFF Research Database (Denmark)

    Sønderby, Casper Kaae; Lundell, Henrik M; Søgaard, Lise V; Dyrby, Tim B

    2014-01-01

    Double-wave diffusion experiments offer the possibility of probing correlation between molecular diffusion at multiple time points. It has recently been shown that this technique is capable of measuring the exchange of water across cellular membranes. The aim of this study was to investigate the ...... effect of macroscopic tissue anisotropy on the measurement of the apparent exchange rate (AXR) in multicompartment systems.......Double-wave diffusion experiments offer the possibility of probing correlation between molecular diffusion at multiple time points. It has recently been shown that this technique is capable of measuring the exchange of water across cellular membranes. The aim of this study was to investigate the...

  17. Apparent resistivity of azimuthal anisotropy layered media

    Institute of Scientific and Technical Information of China (English)

    阮爱国; 毛桐恩; 李清河; 葛双成

    2002-01-01

    The electric field, equations of boundary conditions and calculation formula of apparent resistivity are derived for azimuthal anisotropy layered media with DC method based on anisotropic Ohm(s law. Taking Schlumberger symmetric system as an example and using recurrence formula of nuclear function, the paper theoretically simulates a model of four layers with the same anisotropy coefficient for each layer. The deep sounding curves of resistivity and the pattern of contours are obtained for the model. The results shows the theoretical formula of this paper is correct, the deep sounding curves not only exhibit the difference of resistivity among layers but also indicate the anisotropy characteristics of layers.

  18. Association of early CT abnormalities, infarct size, and apparent diffusion coefficient reduction in acute ischemic stroke

    NARCIS (Netherlands)

    Somford, DM; Marks, MP; Thijs, VN; Tong, DC

    2004-01-01

    BACKGROUND AND PURPOSE: Diffusion-weighted (DW) imaging is more sensitive for early ischemia than CT, and apparent diffusion coefficient (ADC) mapping permits quantification of the severity of cytotoxic edema. We examined the relationship between early CT findings, ischemic lesion volume on DW image

  19. Apparent discordant redshift QSO-galaxy associations

    CERN Document Server

    Lopez-Corredoira, Martin

    2009-01-01

    An "exotic" idea proposed by Viktor Ambartsumian was that new galaxies are formed through the ejection from older active galaxies. Galaxies beget galaxies, instead of the standard scenario in which galaxies stem from the evolution of the seeds derived from fluctuations in the initial density field. This idea is in some way contained in the speculative proposal that some or all QSOs might be objects ejected by nearby galaxies, and that their redshift is not cosmological (Arp, G./M. Burbidge and others). I will discuss some of the arguments for and against this scenario; in particular, I shall talk about the existence of real physical connections in apparently discordant QSO-galaxy redshift associations. On the one hand, there are many statistical correlations of high-redshift QSOs and nearby galaxies that cannot yet be explained in terms of gravitational lensing, biases, or selection effects; and some particular configurations have very low probabilities of being a projection of background objects. Our underst...

  20. Cosmological and black hole apparent horizons

    CERN Document Server

    Faraoni, Valerio

    2015-01-01

    This book overviews the extensive literature on apparent cosmological and black hole horizons. In theoretical gravity, dynamical situations such as gravitational collapse, black hole evaporation, and black holes interacting with non-trivial environments, as well as the attempts to model gravitational waves occurring in highly dynamical astrophysical processes, require that the concept of event horizon be generalized. Inequivalent notions of horizon abound in the technical literature and are discussed in this manuscript. The book begins with a quick review of basic material in the first one and a half chapters, establishing a unified notation. Chapter 2 reminds the reader of the basic tools used in the analysis of horizons and reviews the various definitions of horizons appearing in the literature. Cosmological horizons are the playground in which one should take baby steps in understanding horizon physics. Chapter 3 analyzes cosmological horizons, their proposed thermodynamics, and several coordinate systems....

  1. Field signature for apparently superluminal particle motion

    CERN Document Server

    Land, Martin

    2016-01-01

    In the context of Stueckelberg's covariant symplectic mechanics, Horwitz and Aharonovich have proposed a simple mechanism by which a particle traveling below light speed almost everywhere may exhibit a transit time that suggests superluminal motion. This mechanism, which requires precise measurement of the particle velocity, involves a subtle perturbation affecting the particle's recorded time coordinate caused by virtual pair processes. The Stueckelberg framework is particularly well suited to such problems, because it permits pair creation/annihilation at the classical level. In this paper, we study a trajectory of the type proposed by Horwitz and Aharonovich, and derive the Maxwell 4-vector potential associated with the motion. We show that the resulting fields carry a signature associated with the apparent superluminal motion, providing an independent test for the mechanism that does not require direct observation of the trajectory, except at the detector.

  2. Distribution of apparent magnetization for Asia

    Institute of Scientific and Technical Information of China (English)

    徐元芳; 安振昌; 黄宝春; V.P.Golovkov; N.M.Rotanova; A.L.Kharitonov

    2000-01-01

    Magsat total field anomalies over Asia were used to construct an equivalent magnetization model, which represents the apparent magnetization distribution within an equivalent layer 40 km thick and correlates well with large-scale tectonics, for example, the Kazakhstan, Tarim, Yangtze, India, Sino-Korea and Indochina blocks. The basin, plain, sea basin, and islands are delineated by magnetization lows whereas the plateau and marine ridge correspond to magnetization highs. The boundary between Tibetan Plateau and India marked by a strong gradient along its length coincides with the Yarlung Zangbo River fault roughly. The Tanlu fault belt is the boundary between positive and negative anomalies. This boundary stretches in southwest direction and joins Sanjiang fault belt. The boundary between the Southeast China block and the Yangtze block is also clearly delineated by the magnetization anomalies. Generally, the magnetization boundaries are consistent with the collisional suture of blocks.

  3. Effect of molecular structure on the hydration of structurally related antidepressant drugs

    Science.gov (United States)

    Cheema, M. A.; Taboada, P.; Barbosa, S.; Siddiq, M.; Mosquera, V.

    Apparent molal volumes and adiabatic compressibilities of aqueous solutions of the amphiphilic cationic antidepressant drugs butriptyline and doxepin hydrochlorides have been determined from density and ultrasound velocity measurements in the temperature range 20-50°C. Critical concentrations for aggregation of these drugs were obtained from ultrasound velocity measurements. Negative deviations from the Debye-Hückel limiting law of the apparent molal volume were obtained from both drugs in all temperature ranges, except for doxepin at 50°C, which provides evidence of no pre-association at concentrations below the critical concentration. Apparent molal adiabatic compressibilities of the aggregates formed by these drugs were typical of those corresponding for an aggregate formed by a stacking process.

  4. Thermodynamics of the Apparent Horizon in FRW Universe with Massive Gravity

    International Nuclear Information System (INIS)

    Applying Clausius relation with energy-supply defined by the unified first law of thermodynamics formalism to the apparent horizon of a massive gravity model in cosmology proposed lately, the corrected entropic formula of the apparent horizon is obtained with the help of the modified Friedmann equations. This entropy-area relation, together with the identified Misner-Sharp internal energy, verifies the first law of thermodynamics for the apparent horizon with a volume change term for consistency. On the other hand, by means of the corrected entropy-area formula and the Clausius relation δQ = T d S, where the heat Bow δQ is the energy-supply of pure matter projecting on the vector ξ tangent to the apparent horizon and should be looked on as the amount of energy crossing the apparent horizon during the time interval dt and the temperature of the apparent horizon for energy crossing during the same interval is 1/(2πrA), the modified Friedmann equations governing the dynamical evolution of the universe are reproduced with the known energy density and pressure of massive graviton. The integration constant is found to correspond to a cosmological term which could be absorbed into the energy density of matter. Having established the correspondence of massive cosmology with the unified first law of thermodynamics on the apparent horizon, the validity of the generalized second law of thermodynamics is also discussed by assuming the thermal equilibrium between the apparent horizon and the matter field bounded by the apparent horizon. It is found that, in the limit Hc → 0, which recovers the Minkowski reference metric solution in the fiat case, the generalized second law of thermodynamics holds if α3 + 4α4 3 = α4 = 0, the generalized second law of thermodynamics could be violated. (general)

  5. Measurement and Correlation on Viscosity and Apparent Molar Volume of Ternary System for L-ascorbic Acid in Aqueous D-Glucose and Sucrose Solutions%L-抗坏血酸在葡萄糖和蔗糖溶液中的黏度及其热力学性质的研究

    Institute of Scientific and Technical Information of China (English)

    赵长伟; 马沛生

    2003-01-01

    Viscosities and densities at several temperatures from 293.15 K to 313.15 K are reported for L-ascorbic acid in aqueous glucose and sucrose solutions at different concentrations. The parameters of density, viscosity coefficient B and partial molar volume are calculated by regression. The experimental results show that densities and viscosities decrease as temperature increases at the same solute and solvent (glucose and sucrose aqueous solution) concentrations, and increase with concentration of glucose and sucrose at the same solute concentration and temperature. B increases with concentration of glucose and sucrose and temperature. L-ascorbic acid is structure-breaker or structure-making for the glucose and sucrose aqueous solutions. Furthermore, the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte are discussed.

  6. Discrimination of paediatric brain tumours using apparent diffusion coefficient histograms

    Energy Technology Data Exchange (ETDEWEB)

    Bull, Jonathan G.; Clark, Christopher A. [UCL Institute of Child Health, Imaging and Biophysics Unit, London (United Kingdom); Saunders, Dawn E. [Great Ormond Street Hospital for Children NHS Trust, Department of Radiology, London (United Kingdom)

    2012-02-15

    To determine if histograms of apparent diffusion coefficients (ADC) can be used to differentiate paediatric brain tumours. Imaging of histologically confirmed tumours with pre-operative ADC maps were reviewed (54 cases, 32 male, mean age 6.1 years; range 0.1-15.8 years) comprising 6 groups. Whole tumour ADC histograms were calculated; normalised for volume. Stepwise logistic regression analysis was used to differentiate tumour types using histogram metrics, initially for all groups and then for specific subsets. All 6 groups (5 dysembryoplastic neuroectodermal tumours, 22 primitive neuroectodermal tumours (PNET), 5 ependymomas, 7 choroid plexus papillomas, 4 atypical teratoid rhabdoid tumours (ATRT) and 9 juvenile pilocytic astrocytomas (JPA)) were compared. 74% (40/54) were correctly classified using logistic regression of ADC histogram parameters. In the analysis of posterior fossa tumours, 80% of ependymomas, 100% of astrocytomas and 94% of PNET-medulloblastoma were classified correctly. All PNETs were discriminated from ATRTs (22 PNET and 4 supratentorial ATRTs) (100%). ADC histograms are useful in differentiating paediatric brain tumours, in particular, the common posterior fossa tumours of childhood. PNETs were differentiated from supratentorial ATRTs, in all cases, which has important implications in terms of clinical management. (orig.)

  7. Evidence that a Highway Reduces Apparent Survival Rates of Squirrel Gliders

    Directory of Open Access Journals (Sweden)

    Silvana Cesarini

    2010-09-01

    Full Text Available Roads and traffic are prominent components of most landscapes throughout the world, and their negative effects on the natural environment can extend for hundreds or thousands of meters beyond the road. These effects include mortality of wildlife due to collisions with vehicles, pollution of soil and air, modification of wildlife behavior in response to noise, creation of barriers to wildlife movement, and establishment of dispersal conduits for some plant and animal species. In southeast Australia, much of the remaining habitat for the squirrel glider, Petaurus norfolcensis, is located in narrow strips of Eucalyptus woodland that is adjacent to roads and streams, as well as in small patches of woodland vegetation that is farther from roads. We evaluated the effect of traffic volume on squirrel gliders by estimating apparent annual survival rates of adults along the Hume Freeway and nearby low-traffic-volume roads. We surveyed populations of squirrel gliders by trapping them over 2.5 years, and combined these data with prior information on apparent survival rates in populations located away from freeways to model the ratio of apparent annual survival rates in both site types. The apparent annual survival rate of adult squirrel gliders living along the Hume Freeway was estimated to be approximately 60% lower than for squirrel gliders living near local roads. The cause of the reduced apparent survival rate may be due to higher rates of mortality and/or higher emigration rates adjacent to the Hume Freeway compared with populations near smaller country roads. Management options for population persistence will be influenced by which of these factors is the primary cause of a reduced apparent survival rate.

  8. Predicting the apparent viscosity and yield stress of digested and secondary sludge mixtures.

    Science.gov (United States)

    Eshtiaghi, Nicky; Markis, Flora; Zain, Dwen; Mai, Kiet Hung

    2016-05-15

    The legal banning of conventional sludge disposal methods such as landfill has led to a global movement towards achieving a sustainable sludge management strategy. Reusing sludge for energy production (biogas production) through the anaerobic digestion of sludge can provide a sustainable solution. However, for the optimum performance of digesters with minimal use of energy input, operating conditions must be regulated in accordance with the rheological characteristics of the sludge. If it is assumed that only secondary sludge enters the anaerobic digesters, an impact of variations to the solids concentration and volume fraction of each sludge type must be investigated to understand how the apparent viscosity and yield stress of the secondary and digested sludge mixture inside the digesters changes. In this study, five different total solids concentration of secondary and digested sludge were mixed at different digested sludge volume fractions ranging from 0 to 1. It was found that if secondary sludge was mixed with digested sludge at the same total solids concentration, the apparent viscosity and the yield stress of the mixture increased exponentially by increasing the volume fraction of digested sludge. However, if secondary sludge was added to digested sludge with a different solids concentration, the apparent viscosity and yield stress of the resulting mixed sludge was controlled by the concentrated sludge regardless of its type. Semi - empirical correlations were proposed to predict the apparent viscosity and yield stress of the mixed digested and secondary sludge. A master curve was also developed to predict the flow behaviour of sludge mixtures regardless of the total solid concentration and volume fraction of each sludge type within the studied solids concentration range of 1.4 and 7%TS. This model can be used for digesters optimization and design by predicting the rheology of sludge mixture inside digester. PMID:26994336

  9. Quasar Apparent Proper Motion Observed by Geodetic VLBI Networks

    OpenAIRE

    D. S. MacMillan

    2003-01-01

    In our standard geodetic VLBI solutions, we estimate the positions of quasars assuming that their positions do not vary in time. However, in solutions estimating proper motion, a significant number of quasars show apparent proper motion greater than 50 uas/yr. For individual quasars, there are source structure effects that cause apparent proper motion. To examine how coherent the pattern of apparent proper motion is over the sky, we have estimated the vector spherical harmonic components of t...

  10. Predicting the apparent viscosity and yield stress of mixtures of primary, secondary and anaerobically digested sewage sludge: Simulating anaerobic digesters.

    Science.gov (United States)

    Markis, Flora; Baudez, Jean-Christophe; Parthasarathy, Rajarathinam; Slatter, Paul; Eshtiaghi, Nicky

    2016-09-01

    Predicting the flow behaviour, most notably, the apparent viscosity and yield stress of sludge mixtures inside the anaerobic digester is essential because it helps optimize the mixing system in digesters. This paper investigates the rheology of sludge mixtures as a function of digested sludge volume fraction. Sludge mixtures exhibited non-Newtonian, shear thinning, yield stress behaviour. The apparent viscosity and yield stress of sludge mixtures prepared at the same total solids concentration was influenced by the interactions within the digested sludge and increased with the volume fraction of digested sludge - highlighted using shear compliance and shear modulus of sludge mixtures. However, when a thickened primary - secondary sludge mixture was mixed with dilute digested sludge, the apparent viscosity and yield stress decreased with increasing the volume fraction of digested sludge. This was caused by the dilution effect leading to a reduction in the hydrodynamic and non-hydrodynamic interactions when dilute digested sludge was added. Correlations were developed to predict the apparent viscosity and yield stress of the mixtures as a function of the digested sludge volume fraction and total solids concentration of the mixtures. The parameters of correlations can be estimated using pH of sludge. The shear and complex modulus were also modelled and they followed an exponential relationship with increasing digested sludge volume fraction. PMID:27243386

  11. Separating chemical and excluded volume interactions of polyethylene glycols with native proteins: Comparison with PEG effects on DNA helix formation.

    Science.gov (United States)

    Shkel, Irina A; Knowles, D B; Record, M Thomas

    2015-09-01

    Small and large PEGs greatly increase chemical potentials of globular proteins (μ2), thereby favoring precipitation, crystallization, and protein-protein interactions that reduce water-accessible protein surface and/or protein-PEG excluded volume. To determine individual contributions of PEG-protein chemical and excluded volume interactions to μ2 as functions of PEG molality m3 , we analyze published chemical potential increments μ23  = dμ2/dm3 quantifying unfavorable interactions of PEG (PEG200-PEG6000) with BSA and lysozyme. For both proteins, μ23 increases approximately linearly with the number of PEG residues (N3). A 1 molal increase in concentration of PEG -CH2 OCH2 - groups, for any chain-length PEG, increases μBSA by ∼2.7 kcal/mol and μlysozyme by ∼1.0 kcal/mol. These values are similar to predicted chemical interactions of PEG -CH2 OCH2 - groups with these protein components (BSA ∼3.3 kcal/mol, lysozyme ∼0.7 kcal/mol), dominated by unfavorable interactions with amide and carboxylate oxygens and counterions. While these chemical effects should be dominant for small PEGs, larger PEGS are expected to exhibit unfavorable excluded volume interactions and reduced chemical interactions because of shielding of PEG residues in PEG flexible coils. We deduce that these excluded volume and chemical shielding contributions largely compensate, explaining why the dependence of μ23 on N3 is similar for both small and large PEGs. PMID:25924886

  12. Thermodynamics of the Apparent Horizon in FRW Universe with Massive Gravity

    Institute of Scientific and Technical Information of China (English)

    LI Hui; ZHANG Yi

    2013-01-01

    Applying Clausius relation with energy-supply defined by the unified first law of thermodynamics formalism to the apparent horizon of a massive gravity model in cosmology proposed lately,the corrected entropic formula of the apparent horizon is obtained with the help of the modified Friedmann equations.This entropy-area relation,together with the identified Misner-Sharp internal energy,verifies the first law of thermodynamics for the apparent horizon with a volume change term for consistency.On the other hand,by means of the corrected entropy-area formula and the Clausius relation δQ =T dS,where the heat flow δQ is the energy-supply of pure matter projecting on the vector ξ tangent to the apparent horizon and should be looked on as the amount of energy crossing the apparent horizon during the time interval dt and the temperature of the apparent horizon for energy crossing during the same interval is 1/(2π(r)A),the modified Friedmann equations governing the dynamical evolution of the universe are reproduced with the known energy density and pressure of massive graviton.The integration constant is found to correspond to a cosmological term which could be absorbed into the energy density of matter.Having established the correspondence of massive cosmology with the unified first law of thermodynamics on the apparent horizon,the validity of the generalized second law of thermodynamics is also discussed by assuming the thermal equilibrium between the apparent horizon and the matter field bounded by the apparent horizon.It is found that,in the limit Hc → 0,which recovers the Minkowski reference metric solution in the flat case,the generalized second law of thermodynamics holds if α3 + 4α4 < 0.Without this condition,even for the simplest model of dRGT massive cosmology with α3 =α4 =0,the generalized second law of thermodynamics could be violated.

  13. Multiple weather factors affect apparent survival of European passerine birds.

    Directory of Open Access Journals (Sweden)

    Volker Salewski

    Full Text Available Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and

  14. Precursory specialties of apparent stresses in Yunnan earthquake series

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-gui; LIU Jie; DING Ye-ling; SUN Ye-jun; YU Xin

    2006-01-01

    On the basis of the assumption that ω2 model accords with source displacement spectra, we have obtained the mathematical expressions for calculating apparent stresses of moderate-small shocks from low-frequency flat level and comer frequency. By using digital seismic records, apparent stress values are calculated for 823 moderate-small shocks of 4 earthquake series in Yunnan area following corrections for instrument response, propagation influence and site effect. The results show that for the 4 earthquake series in Yunnan area, apparent stress hints precursory information, which means that if a moderate-small shock occurs with apparent stress larger than 1 MPa in an earthquake series, a moderate-strong earthquake will occur afterwards; and if there is not moderate-small shock with apparent stress larger than 1 MPa after a moderate-strong event in an earthquake series, strong aftershock will not occur. The research also indicates that the average apparent stress value is 0.8 MPa in Yunnan area, therefore, apparent stress is not obviously related to seismic magnitude.

  15. Volume Entropy

    OpenAIRE

    Astuti, Valerio; Christodoulou, Marios; Rovelli, Carlo

    2016-01-01

    Building on a technical result by Brunnemann and Rideout on the spectrum of the Volume operator in Loop Quantum Gravity, we show that the dimension of the space of the quadrivalent states --with finite-volume individual nodes-- describing a region with total volume smaller than $V$, has \\emph{finite} dimension, bounded by $V \\log V$. This allows us to introduce the notion of "volume entropy": the von Neumann entropy associated to the measurement of volume.

  16. Apparent Ionic Charge in Electrolyte and Polyelectrolyte Solutions

    Science.gov (United States)

    Magdelenat, H.; And Others

    1978-01-01

    Compares average displacements of charged particles under thermal motion alone with those obtained by the action of an external electric field to develop a concept of "apparent charge" to approximate actual structural charge in an electrolyte solution. (SL)

  17. Analysis of Apparent Elasticity Constants of Woven Fabrics

    Institute of Scientific and Technical Information of China (English)

    董侠; 张建春; 张燕

    2001-01-01

    The woven fabric can be defined as orthogonal elastomer if the extension force that puts on the fabric is very small. Based on the precondition, the apparent elasticity constants of a woven fabric were analyzed theoretically in the paper. The bias angle (which is between weft yarns and extension direction ) affects apparent elasticity modulus and elasticity coefficient of the fabric in the extension direction. And the experiment describes fluxes of elasticity constants going with the bias angle of the fabric.

  18. Finding Apparent Horizons in Dynamic 3D Numerical Spacetimes

    OpenAIRE

    Anninos, P.; Camarda, K.; Libson, J.; Masso, J.; Seidel, E; Suen, W.

    1996-01-01

    We have developed a general method for finding apparent horizons in 3D numerical relativity. Instead of solving for the partial differential equation describing the location of the apparent horizons, we expand the closed 2D surfaces in terms of symmetric trace--free tensors and solve for the expansion coefficients using a minimization procedure. Our method is applied to a number of different spacetimes, including numerically constructed spacetimes containing highly distorted axisymmetric blac...

  19. Diurnal and seasonal trends in the apparent density of ambient fine and coarse particles in Los Angeles

    International Nuclear Information System (INIS)

    Diurnal and seasonal variations in the apparent density of ambient fine and coarse particulate matter (PM2.5 and CPM [PM2.5–10], respectively) were investigated in a location near downtown Los Angeles. The apparent densities, determined by particle mass-to-volume ratios, showed strong diurnal and seasonal variations, with higher values during the warm phase (June to August 2013) compared to cold phase (November 2012 to February 2013). PM2.5 apparent density showed minima during the morning and afternoon rush hours of the cold phase (1.20 g cm−3), mainly due to the increased contribution of traffic-emitted soot particles, and highest values were found during the midday in the warm phase (2.38 g cm−3). The lowest CPM apparent density was observed during the morning rush hours of the cold phase (1.41 g cm−3), while highest in early afternoon during the warm phase (2.91 g cm−3), most likely due to the increased wind-induced resuspension of road dust. - Highlights: • Hourly apparent density of ambient fine and coarse PM was measured in Los Angeles. • Apparent densities were higher during the warm season. • PM2.5 apparent density showed minima during the traffic rush hours. • Coarse PM apparent density showed a similar diurnal trend with wind speed in summer. - The apparent density of ambient particles, a direct tracer of chemical composition and morphology, shows strong seasonal and diurnal variability

  20. Tomographic method for evaluation of apparent activation energy of steady-state creep

    International Nuclear Information System (INIS)

    A new method for the evaluation of the apparent activation energy of steady-state creep in metals is presented. It is based on in situ monitoring by microtomography the geometry of a specimen subjected to uniaxial load and inhomogeneous temperature distribution. It is shown that microtomography acting as a three dimensional extensometer enables the evaluation of local strain-rates of small material volumes and is an adequate tool for characterization of inhomogeneously deforming specimens. Activation energies obtained with the new method for stainless steel agree within an error of 5% with values obtained according to the classical procedure.

  1. Total individual ion activity coefficients of calcium and carbonate in seawater at 25°C and 35%. salinity, and implications to the agreement between apparent and thermodynamic constants of calcite and aragonite

    Science.gov (United States)

    Plummer, L. Neil; Sundquist, Eric T.

    1982-01-01

    We have calculated the total individual ion activity coefficients of carbonate and calcium,  and , in seawater. Using the ratios of stoichiometric and thermodynamic constants of carbonic acid dissociation and total mean activity coefficient data measured in seawater, we have obtained values which differ significantly from those widely accepted in the literature. In seawater at 25°C and 35%. salinity the (molal) values of  and  are 0.038 ± 0.002 and 0.173 ± 0.010, respectively. These values of  and  are independent of liquid junction errors and internally consistent with the value . By defining  and  on a common scale (), the product  is independent of the assigned value of  and may be determined directly from thermodynamic measurements in seawater. Using the value  and new thermodynamic equilibrium constants for calcite and aragonite, we show that the apparent constants of calcite and aragonite are consistent with the thermodynamic equilibrium constants at 25°C and 35%. salinity. The demonstrated consistency between thermodynamic and apparent constants of calcite and aragonite does not support a hypothesis of stable Mg-calcite coatings on calcite or aragonite surfaces in seawater, and suggests that the calcite critical carbonate ion curve of Broecker and Takahashi (1978,Deep-Sea Research25, 65–95) defines the calcite equilibrium boundary in the oceans, within the uncertainty of the data.

  2. Hawking Radiation of Apparent Horizon in a FRW Universe

    CERN Document Server

    Cai, Rong-Gen; Hu, Ya-Peng

    2008-01-01

    Hawking radiation is an important quantum phenomenon of black hole, which is closely related to the existence of event horizon of black hole. The cosmological event horizon of de Sitter space is also of the Hawking radiation with thermal spectrum. By use of the tunneling approach proposed by Parikh and Wilczek, we show that there is indeed a Hawking radiation with temperature, $T=1/2\\pi \\tilde r_A$, for locally defined apparent horizon of Friedmann-Robertson-Walker universe with any spatial curvature, where $\\tilde r_A$ is the apparent horizon radius. Thus we fill in the gap existing in the literature investigating the relation between the first law of thermodynamics and Friedmann equations. In addition, we stress the implication of the Hawking temperature associated with the apparent horizon.

  3. Shape reconstruction from apparent contours theory and algorithms

    CERN Document Server

    Bellettini, Giovanni; Paolini, Maurizio

    2015-01-01

    Motivated by a variational model concerning the depth of the objects in a picture and the problem of hidden and illusory contours, this book investigates one of the central problems of computer vision: the topological and algorithmic reconstruction of a smooth three dimensional scene starting from the visible part of an apparent contour. The authors focus their attention on the manipulation of apparent contours using a finite set of elementary moves, which correspond to diffeomorphic deformations of three dimensional scenes. A large part of the book is devoted to the algorithmic part, with implementations, experiments, and computed examples. The book is intended also as a user's guide to the software code appcontour, written for the manipulation of apparent contours and their invariants. This book is addressed to theoretical and applied scientists working in the field of mathematical models of image segmentation.

  4. Volume-to-volume registration

    OpenAIRE

    Harg, Erik

    2005-01-01

    Implementation of automated volume-to-volume registration applications for three separate registration steps desired in enhancing neurosurgical navigation is considered. Prototype implementations for MRI-to-MRI registration, MRI-to-US registration and US-to-US registration have been made using registration methods available in the Insight Toolkit, with variants of the Mutual Information similarity metric. The obtained results indicate that automatic volume-to-volume registration using Normali...

  5. Prevalence of upper airway obstruction in patients with apparently asymptomatic euthyroid multi nodular goitre

    Directory of Open Access Journals (Sweden)

    Sunil K Menon

    2011-01-01

    Full Text Available Aims: To study the prevalence of upper airway obstruction (UAO in "apparently asymptomatic" patients with euthyroid multinodular goitre (MNG and find correlation between clinical features, UAO on pulmonary function test (PFT and tracheal narrowing on computerised tomography (CT. Materials and Methods: Consecutive patients with apparently asymptomatic euthyroid MNG attending thyroid clinic in a tertiary centre underwent clinical examination to elicit features of UAO, PFT, and CT of neck and chest. Statistical Analysis Used: Statistical analysis was done with SPSS version 11.5 using paired t-test, Chi square test, and Fisher′s exact test. P value of <0.05 was considered to be significant. Results: Fifty-six patients (52 females and four males were studied. The prevalence of UAO (PFT and significant tracheal narrowing (CT was 14.3%. and 9.3%, respectively. Clinical features failed to predict UAO or significant tracheal narrowing. Tracheal narrowing (CT did not correlate with UAO (PFT. Volume of goitre significantly correlated with degree of tracheal narrowing. Conclusions: Clinical features do not predict UAO on PFT or tracheal narrowing on CT in apparently asymptomatic patients with euthyroid MNG.

  6. Prevalence of upper airway obstruction in patients with apparently asymptomatic euthyroid multi nodular goitre

    Science.gov (United States)

    Menon, Sunil K.; Jagtap, Varsha S.; Sarathi, Vijaya; Lila, Anurag R.; Bandgar, Tushar R.; Menon, Padmavathy S; Shah, Nalini S.

    2011-01-01

    Aims: To study the prevalence of upper airway obstruction (UAO) in “apparently asymptomatic” patients with euthyroid multinodular goitre (MNG) and find correlation between clinical features, UAO on pulmonary function test (PFT) and tracheal narrowing on computerised tomography (CT). Materials and Methods: Consecutive patients with apparently asymptomatic euthyroid MNG attending thyroid clinic in a tertiary centre underwent clinical examination to elicit features of UAO, PFT, and CT of neck and chest. Statistical Analysis Used: Statistical analysis was done with SPSS version 11.5 using paired t-test, Chi square test, and Fisher's exact test. P value of <0.05 was considered to be significant. Results: Fifty-six patients (52 females and four males) were studied. The prevalence of UAO (PFT) and significant tracheal narrowing (CT) was 14.3%. and 9.3%, respectively. Clinical features failed to predict UAO or significant tracheal narrowing. Tracheal narrowing (CT) did not correlate with UAO (PFT). Volume of goitre significantly correlated with degree of tracheal narrowing. Conclusions: Clinical features do not predict UAO on PFT or tracheal narrowing on CT in apparently asymptomatic patients with euthyroid MNG. PMID:21966649

  7. Enhancement of apparent resistance to ethanol in Lactobacillus hilgardii

    OpenAIRE

    Couto, José António; Pina, Cristina; Hogg, Tim

    1997-01-01

    The survival of Lactobacillus hilgardii, a highly ethanol-tolerant organism, after an ethanol challenge at 25% (v/v) for 10 min, increased by several log cycles when cells, grown in the absence of ethanol, were pre-treated with 10% (v/v) ethanol, 15% (v/v) methanol or 2% (v/v) butanol for 4 h. A temperature upshift (25 to 40°C) before ethanol challenge demonstrated a similar enhancement of apparent resistance to ethanol. Ethanol shock enhanced apparent resistance to methanol, butanol and heat...

  8. Measurement of Temperature Dependent Apparent Specific Heat Capacity in Electrosurgery.

    Science.gov (United States)

    Karaki, Wafaa; Akyildiz, Ali; Borca Tasciuc, Diana-Andra; De, Suvranu

    2016-01-01

    This paper reports on the measurement of temperature dependent apparent specific heat of ex-vivo porcine liver tissue during radiofrequency alternating current heating for a large temperature range. The difference between spatial and temporal evolution of experimental temperature, obtained during electrosurgical heating by infrared thermometry, and predictions based on finite element modeling was minimized to obtain the apparent specific heat. The model was based on transient heat transfer with internal heat generation considering heat storage along with conduction. Such measurements are important to develop computational models for real time simulation of electrosurgical procedures. PMID:27046573

  9. Imaging malignant and apparent malignant transformation of benign gynaecological disease

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A.Y.; Poder, L.; Qayyum, A.; Wang, Z.J.; Yeh, B.M. [Department of Radiology, University of California San Francisco, San Francisco, CA (United States); Coakley, F.V., E-mail: Fergus.Coakley@radiology.ucsf.ed [Department of Radiology, University of California San Francisco, San Francisco, CA (United States)

    2010-12-15

    Common benign gynaecological diseases, such as leiomyoma, adenomyosis, endometriosis, and mature teratoma, rarely undergo malignant transformation. Benign transformations that may mimic malignancy include benign metastasizing leiomyoma, massive ovarian oedema, decidualization of endometrioma, and rupture of mature teratoma. The aim of this review is to provide a contemporary overview of imaging findings in malignant and apparent malignant transformation of benign gynaecological disease.

  10. Imaging malignant and apparent malignant transformation of benign gynaecological disease

    International Nuclear Information System (INIS)

    Common benign gynaecological diseases, such as leiomyoma, adenomyosis, endometriosis, and mature teratoma, rarely undergo malignant transformation. Benign transformations that may mimic malignancy include benign metastasizing leiomyoma, massive ovarian oedema, decidualization of endometrioma, and rupture of mature teratoma. The aim of this review is to provide a contemporary overview of imaging findings in malignant and apparent malignant transformation of benign gynaecological disease.

  11. CCD photometry of apparent dwarf galaxies in Fornax

    International Nuclear Information System (INIS)

    Blue and red CCD surface photometry of two apparent dwarf galaxies in the Fornax cluster region is presented. Luminosity profiles are derived and their form discussed. The fainter galaxy resembles an archetypal diffuse dwarf elliptical but the brighter of the pair is either an unusual red dwarf or a background galaxy in chance juxtaposition. (author)

  12. On the apparent horizon in fluid-gravity duality

    NARCIS (Netherlands)

    I. Booth; M.P. Heller; G. Plewa; M. Spalinski

    2011-01-01

    This article develops a computational framework for determining the location of boundary-covariant apparent horizons in the geometry of conformal fluid-gravity duality in arbitrary dimensions. In particular, it is shown up to second order and conjectured to hold to all orders in the gradient expansi

  13. Studying the cosmological apparent horizon with quasistatic coordinates

    Indian Academy of Sciences (India)

    Rui-Yan Yu; Towe Wang

    2013-02-01

    This article aims at a natural generalization of the static coordinates to the ( + 1)-dimensional Friedmann–Lemaître–Robertson–Walker (FLRW) Universe. After demonstrating a no-go theorem, we put forward the quasistatic coordinates for the FLRW Universe. Then, the quasistatic coordinates are utilized to study the unified first law and the scalar-type perturbations on the cosmological apparent horizon.

  14. Apparent mineralocorticoid excess: time of manifestation and complications despite treatment

    NARCIS (Netherlands)

    Knops, N.B.; Monnens, L.A.H.; Lenders, J.W.M.; Levtchenko, E.N.

    2011-01-01

    Here we describe the case of a patient followed from birth because of a positive family history for apparent mineralocorticoid excess (AME) in an older brother. The patient, a girl, had normal serum electrolyte and blood pressure measurements in the first months after birth. Not until the age of 11

  15. Apparently Ipsilateral Parkinsonism in a Patient with Chronic Subdural Hematoma

    Directory of Open Access Journals (Sweden)

    Tae Hwan Roh

    2012-05-01

    Full Text Available Symptomatic parkinsonism secondary to ipsilateral lesion is rarely reported. Although the contribution of the contralateral lesions was assumed in some cases, the pathomechanism remains undetermined. Herein we report a patient with a subdural hematoma, who developed parkinsonism in the ipsilateral hemibody. Structural and functional imaging suggests the contralateral dopaminergic dysfunction as the major culprit of apparently ipsilateral parkinsonism.

  16. Apparent Dissolution Kinetics of Diatomite in Alkaline Solution

    Institute of Scientific and Technical Information of China (English)

    DU Gaoxiang; L(U) Guocheng; HE Xuwen

    2013-01-01

    The dissolution kinetics of diatomite in alkaline solution is the theoretical basis for the process optimization of alkali-diatomite reaction and its applications.In this study,the dissolution kinetics of diatomite in NaOH solution is investigated.The results indicate that the dissolution reaction fits well the unreacted shrinking core model for solid-liquid heterogeneous reactions.The apparent reaction order for NaOH is 2 and the apparent activation energy for the reaction (Ea) is 28.06 kJ.mol-1.The intra-particle diffusion through the sodium silicate layer is the rate-controlling step.When the dissolution reaction occurs at the interface of unreacted diatomite solid core,the diffusion in the trans-layer (the liquid film around the wetted particle) reduces the rate of whole dissolution process.

  17. The Apparent and Intrinsic Shape of the APM Galaxy Clusters

    CERN Document Server

    Basilakos, S; Manolis, P; Basilakos, Spyros; Maddox, Steve; Plionis, Manolis

    2000-01-01

    We estimate the distribution of intrinsic shapes of APM galaxy clusters fromthe distribution of their apparent shapes. We measure the projected clusterellipticities using two alternative methods. The first method is based onmoments of the discrete galaxy distribution while the second is based onmoments of the smoothed galaxy distribution. We study the performance of bothmethods using Monte Carlo cluster simulations covering the range of APM clusterdistances and including a random distribution of background galaxies. We findthat the first method suffers from severe systematic biases, whereas the secondis more reliable. After excluding clusters dominated by substructure andquantifying the systematic biases in our estimated shape parameters, we recovera corrected distribution of projected ellipticities. We use the non-parametrickernel method to estimate the smooth apparent ellipticity distribution, andnumerically invert a set of integral equations to recover the correspondingdistribution of intrinsic ellipticiti...

  18. Rheometric Study of Apparent Wall Slip in Microdispersions

    Czech Academy of Sciences Publication Activity Database

    Večeř, M.; Pěnkavová, Věra; Wein, Ondřej

    Göteborg: Chalmers Reproservice, 2011 - (Sjoqvist, M.), s. 307-312 ISBN 978-952-15-2589-6. ISSN 1601-4057. [The Nordic Rheology Conference. Helsinki (FI), 08.06.2011-10.06.2011] R&D Projects: GA ČR GA104/09/0972; GA ČR GA104/07/1110 Institutional research plan: CEZ:AV0Z40720504 Keywords : apparent wall slip * microdispersion * rheology Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. Apparent Viscosity of Active Nematics in Poiseuille Flow

    Science.gov (United States)

    Cui, Zhenlu; Su, Jianbing; Zeng, Xiaoming

    2015-09-01

    A Leslie-Erickson continuum hydrodynamic for flowing active nematics has been used to characterize active particle systems such as bacterial suspensions. The behavior of such a system under a plane pressure-driven Poiseuille flow is analyzed. When plate anchoring is tangential and normal, we find the apparent viscosity formula indicating a significant difference between tangential anchoring and normal anchoring conditions for both active rodlike and discoid nematics.

  20. Definition of apparent activation energy on DTG curves

    Directory of Open Access Journals (Sweden)

    A. K. Serikbayeva

    2016-07-01

    Full Text Available The article gives the results of sulphidation oxidized copper ores and tailings with sulfur. Defined by the apparent activation energy in the conditions of heating the mixture of substances interacting with a constant speed by differential thermogravimetry (DTG. It was established that the sulfiding may occur in a kinetic mode , since the interaction is charged, in the presence of liquid and gaseous sulfur , i.e. transport of sulfur to the surface of the mineral is not a limiting process.

  1. Mass density at geostationary orbit and apparent mass refilling

    Science.gov (United States)

    Denton, R. E.; Takahashi, Kazue; Amoh, Justice; Singer, H. J.

    2016-04-01

    We used the inferred equatorial mass density ρm,eq based on measurements of Alfvén wave frequencies measured by the GOES satellites during 1980-1991 in order to construct a number of different models of varying complexity for the equatorial mass density at geostationary orbit. The most complicated models are able to account for 66% of the variance with a typical variation from actual values of a factor of 1.56. The factors that influenced ρm,eq in the models were, in order of decreasing importance, the F10.7 EUV index, magnetic local time, the solar wind dynamic pressure Pdyn, the phase of the year, and the solar wind BZ (GSM Z direction). During some intervals, some of which were especially geomagnetically quiet, ρm,eq rose to values that were significantly higher than those predicted by our models. For 10 especially quiet intervals, we examined long-term (>1 day) apparent refilling, the increase in ρm,eq at a fixed location. We found that the behavior of ρm,eq varies for different events. In some cases, there is significant apparent refilling, whereas in other cases ρm,eq stays the same or even decreases slightly. Nevertheless, we showed that on average, ρm,eq increases exponentially during quiet intervals. There is variation of apparent refilling with respect to the phase of the solar cycle. On the third day of apparent refilling, ρm,eq has on average a similar value at solar maximum or solar minimum, but at solar maximum, ρm,eq begins with a larger value and rises relatively less than at solar minimum.

  2. Information Limits on Identification of Natural Surfaces by Apparent Colour

    OpenAIRE

    Foster, David H.; Nascimento, Sérgio M. C.; Amano, Kinjiro

    2005-01-01

    By adaptational and other mechanisms, the visual system can compensate for moderate changes in the colour of the illumination on a scene. Although the colours of most surfaces are perceived to be constant (“colour constancy”), some are not. The effect of these residual colour changes on the ability of observers to identify surfaces by their apparent colour was determined theoretically from high-resolution hyperspectral images of natural scenes under different daylights with correlated colour ...

  3. Infants' perception of subjective contours from apparent motion.

    Science.gov (United States)

    Yamaguchi, Masami K; Kanazawa, So; Okamura, Hiromi

    2008-01-01

    We examined infants' perception of subjective contours in Subjective-Contour-from-Apparent-Motion (SCAM) stimuli [e.g., Cicerone, C. M., Hoffman, D. D., Gowdy, P. D., & Kim, J. S. (1995). The perception of color from motion. Perception & Psychophysics, 57, 761-777] using the preferential looking technique. The SCAM stimulus is composed of random dots which are assigned two different colors. Circular region assigned one color moved apparently, keeping all dots' location unchanged. In the SCAM stimulus, adults can perceive subjective color spreading and subjective contours in apparent motion (http://c-faculty.chuo-u.ac.jp/ approximately ymasa/okamura/ibd_demo.html). In the present study, we conducted two experiments by using this type of SCAM stimulus. A total of thirty-six 3-8-month-olds participated. In experiment 1, we presented two stimuli to the infants side by side: a SCAM stimulus consisting of different luminance, and a non-SCAM stimulus consisting of isoluminance dots. The results indicated that the 5-8-month-olds showed preference for the SCAM stimuli. In experiments 2 and 3, we confirmed that the infants' preference for the SCAM stimulus was not generated by the local difference and local change made by luminance of dots but by the subjective contours. These results suggest that 5-8-month-olds were able to perceive subjective contours in the SCAM stimuli. PMID:17727955

  4. Apparent directional spectral emissivity determination of semitransparent materials

    Science.gov (United States)

    Chun-Yang, Niu; Hong, Qi; Ya-Tao, Ren; Li-Ming, Ruan

    2016-04-01

    An inverse estimation method and corresponding measurement system are developed to measure the apparent spectral directional emissivities of semitransparent materials. The normal spectral emissivity and transmissivity serve as input for the inverse analysis. Consequently, the refractive index and absorption coefficient of the semitransparent material could be retrieved by using the pseudo source adding method as the forward method and the stochastic particle swarm optimization algorithm as the inverse method. Finally, the arbitrary apparent spectral directional emissivity of semitransparent material is estimated by using the pseudo source adding method given the retrieval refractive index and absorption coefficient. The present system has the advantage of a simple experimental structure, high accuracy, and excellent capability to measure the emissivity in an arbitrary direction. Furthermore, the apparent spectral directional emissivity of sapphire at 773 K is measured by using this system in a spectral range of 3 μm–12 μm and a viewing range of 0°–90°. The present method paves the way for a new directional spectral emissivity measurement strategy. Project supported by the National Natural Science Foundation of China (Grant Nos. 51476043 and 51576053) and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51421063).

  5. Volumetric properties of glucose in aqueous HCI solutions at temperatures from 278.15 to 318.15 K

    Institute of Scientific and Technical Information of China (English)

    ZHUO Kelei; ZHANG Qiufen; XUAN Xiaopeng; ZHANG Hucheng; WANG Jianji

    2007-01-01

    Densities have been measured for Glucose+HC1 +Water at 10-degree intervals from 278.15 to 318.15 K.The apparent molar volumes (Vφ,G) and standard partial molar volumes (V0φ,G) for Glucose in aqueous solution of 0.2,0.4,0.7,1.1,1.6,2.1 mol.kg-1 HCI have been calculated as well as volumetric interaction parameters (VEG) for Glucose-HC1 in water and standard partial molar expansion coefficients ((e)V0φ,G/(e)T)p.Results show that (1) the apparent molar volume for Glucose in aqueous HC1 solutions increases lineally with increasing molality of Glucose and HC1; (2) V0φ,Gfor Glucose in aqueous HC1 solutions increases lineally with increasing molality of HC1; (3) the volumetric interaction parameters for Glucose-HC1 pair in water are small positive and vary slightly with temperature; (4) the relation between V0φ,G and temperature exists as V0φ,G =α0+α1(T-273.15 K)2/3;(5)values of((e)V0φ,G/(e)T)p are positive and increase as temperatures rise,and at given temperatures decrease slightly with increasing molalities of HC1,indicating that the hydration of glucose decreases with increasing temperature and molality of HCI.These phenomena are interpreted successfully by the structure interaction model.

  6. Apparent faster than light propagation from light sterile neutrinos

    CERN Document Server

    Hannestad, Steen

    2011-01-01

    Recent data from the OPERA experiment seem to point to neutrinos propagating faster than light. One possible physics explanation for such a result is the existence of light sterile neutrinos which can propagate in a higher dimensional bulk and achieve apparent superluminal velocities when measured by an observer confined to the 4D brane of the standard model. Such a model has the advantage of easily being able to explain the non-observation of superluminal neutrinos from SN1987A. Here we discuss the phenomenological implications of such a model and show that it can provide an explanation for the observed faster than light propagation of neutrinos.

  7. Hjertestop associeret med syndrome of apparent mineralocorticoid excess

    DEFF Research Database (Denmark)

    Meldgaard-Nielsen, Anne; Laugesen, Esben; Poulsen, Per Løgstrup

    Ventricular fibrillation is an unknown complication to the syndrome of apparent mineralocorticoid excess (SAME). This case report describes a young woman admitted with hypo-kalaemia and hypertension. Concentrations of both P-renin and P-aldosterone were low and urinary steroid metabolites revealed...... an abnormal excretion pattern pointing to the diagnosis of SAME. Three years later the woman suffered from ventricular fibrillation due to the hypokalaemia caused by her disease. This case report demonstrates the need for increased attention on the potassium concentration in patients with SAME....

  8. Mechanical Components from Highly Recoverable, Low Apparent Modulus Materials

    Science.gov (United States)

    Padula, Santo, II (Inventor); Noebe, Ronald D. (Inventor); Stanford, Malcolm K. (Inventor); DellaCorte, Christopher (Inventor)

    2015-01-01

    A material for use as a mechanical component is formed of a superelastic intermetallic material having a low apparent modulus and a high hardness. The superelastic intermetallic material is conditioned to be dimensionally stable, devoid of any shape memory effect and have a stable superelastic response without irrecoverable deformation while exhibiting strains of at least 3%. The method of conditioning the superelastic intermetallic material is described. Another embodiment relates to lightweight materials known as ordered intermetallics that perform well in sliding wear applications using conventional liquid lubricants and are therefore suitable for resilient, high performance mechanical components such as gears and bearings.

  9. Apparent dose equivalents resulting from severe heating of film dosimeters

    International Nuclear Information System (INIS)

    Unusual reported dose equivalents due to high-energy photons for two individuals prompted the investigation of the effects of severe heating conditions expected in closed vehicles during southwestern summer months on commercial film dosimeters. A historical review of dosimetry records revealed several additional reported high-energy photon exposures for individuals using only beta-emitting radioisotopes during hot summer months. Between 20-100% of experimentally heated badges had apparent dose equivalents exceeding the minimal detectable dose equivalent that were not flagged as being heat damaged or having unusual exposure patterns by the dosimetry companies. Reported dose equivalents for these badges were as high as 2.1 mSv

  10. Downscaling Smooth Tomographic Models: Separating Intrinsic and Apparent Anisotropy

    Science.gov (United States)

    Bodin, Thomas; Capdeville, Yann; Romanowicz, Barbara

    2016-04-01

    In recent years, a number of tomographic models based on full waveform inversion have been published. Due to computational constraints, the fitted waveforms are low pass filtered, which results in an inability to map features smaller than half the shortest wavelength. However, these tomographic images are not a simple spatial average of the true model, but rather an effective, apparent, or equivalent model that provides a similar 'long-wave' data fit. For example, it can be shown that a series of horizontal isotropic layers will be seen by a 'long wave' as a smooth anisotropic medium. In this way, the observed anisotropy in tomographic models is a combination of intrinsic anisotropy produced by lattice-preferred orientation (LPO) of minerals, and apparent anisotropy resulting from the incapacity of mapping discontinuities. Interpretations of observed anisotropy (e.g. in terms of mantle flow) requires therefore the separation of its intrinsic and apparent components. The "up-scaling" relations that link elastic properties of a rapidly varying medium to elastic properties of the effective medium as seen by long waves are strongly non-linear and their inverse highly non-unique. That is, a smooth homogenized effective model is equivalent to a large number of models with discontinuities. In the 1D case, Capdeville et al (GJI, 2013) recently showed that a tomographic model which results from the inversion of low pass filtered waveforms is an homogenized model, i.e. the same as the model computed by upscaling the true model. Here we propose a stochastic method to sample the ensemble of layered models equivalent to a given tomographic profile. We use a transdimensional formulation where the number of layers is variable. Furthermore, each layer may be either isotropic (1 parameter) or intrinsically anisotropic (2 parameters). The parsimonious character of the Bayesian inversion gives preference to models with the least number of parameters (i.e. least number of layers, and

  11. Physiologic Basis for Improved Pulmonary Function after Lung Volume Reduction

    OpenAIRE

    Fessler, Henry E.; Scharf, Steven M; Ingenito, Edward P.; McKenna, Robert J.; Sharafkhaneh, Amir

    2008-01-01

    It is not readily apparent how pulmonary function could be improved by resecting portions of the lung in patients with emphysema. In emphysema, elevation in residual volume relative to total lung capacity reduces forced expiratory volumes, increases inspiratory effort, and impairs inspiratory muscle mechanics. Lung volume reduction surgery (LVRS) better matches the size of the lungs to the size of the thorax containing them. This restores forced expiratory volumes and the mechanical advantage...

  12. Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi, Tomoyoshi; Shuto, Kiyohiko; Okazumi, Shinichi; Hayano, Kohichi; Satoh, Asami; Saitoh, Hiroshige; Shimada, Hideaki; Nabeya, Yoshihiro; Matsubara, Hisahiro [Chiba University, Department of Frontier Surgery, Graduate School of Medicine, Chiba (Japan); Kazama, Toshiki [Chiba University, Department of Radiology, Graduate School of Medicine, Chiba (Japan)

    2012-06-15

    Because diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis. Seventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis. The ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = -0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026). Our results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer. circle Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen circle There is also negative correlation between ADCs and vascular endothelial growth factor circle ADC values may contribute to the treatment of oesophageal cancer. (orig.)

  13. Area Invariance of Apparent Horizons under Arbitrary Boosts

    CERN Document Server

    Akcay, Sarp

    2007-01-01

    It is a well known analytic result in general relativity that the 2-dimensional area of the horizon of a black hole remains invariant regardless of the motion of the observer, and in fact is independent of the $ t=constant $ slice, which can be quite arbitrary in general relativity. Nonetheless the explicit computation of horizon area is often substantially more difficult in some frames (complicated by the coordinate form of the metric), than in other frames. Here we give an explicit demonstration for very restricted metric forms of (Schwarzschild and Kerr) vacuum black holes. In the Kerr-Schild coordinate expression for these spacetimes they have an explicit Lorentz-invariant form. We consider {\\it boosted} versions with the black hole moving through the coordinate system. Since these are stationary black hole spacetimes, the apparent horizons are 2D crosssections of their event horizons, so we compute the areas of apparent horizons in the boosted space with (boosted) $ t = constant $, and obtain the same re...

  14. Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis

    International Nuclear Information System (INIS)

    Because diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis. Seventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis. The ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = -0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026). Our results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer. circle Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen circle There is also negative correlation between ADCs and vascular endothelial growth factor circle ADC values may contribute to the treatment of oesophageal cancer. (orig.)

  15. Prendre au sérieux les apparences

    Directory of Open Access Journals (Sweden)

    Mark Wynn

    2012-07-01

    Full Text Available Ce texte explore certaines implications de l'idée selon laquelle des pensées religieuses peuvent faire partie de l'apparence sensorielle des choses. Je commence par clarifier cette idée en utilisant des exemples exposés par Roger Scruton qui discute la phénoménologie de l'expérience architecturale. Ensuite, je considère, d'un point de vue pragmatique et épistémique, l'apport de cette idée pour l'argument pour les croyances religieuses. Plus précisément, j'explore comment l'idée d'une relation interne entre la pensée religieuse et les apparences sensorielles des choses peut être utilisée i pour formuler avec nuances l'argument de William James dans « La volonté de croire » et ii pour présenter un argument épistémique pour les croyances religieuses dont l'importance des affirmations centrales est assez couramment reconnue par les croyants mais qui n'a pas été beaucoup discutée par les philosophes.

  16. Apparent Yield Strength of Hot-Pressed SiCs

    Energy Technology Data Exchange (ETDEWEB)

    Daloz, William L [ORNL; Wereszczak, Andrew A [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville

    2008-01-01

    Apparent yield strengths (YApp) of four hot-pressed silicon carbides (SiC-B, SiC-N,SiC-HPN, and SiC-SC-1RN) were estimated using diamond spherical or Hertzian indentation. The von Mises and Tresca criteria were considered. The developed test method was robust, simple and quick to execute, and thusly enabled the acquisition of confident sampling statistics. The choice of indenter size, test method, and method of analysis are described. The compressive force necessary to initiate apparent yielding was identified postmortem using differential interference contrast (or Nomarski) imaging with an optical microscope. It was found that the YApp of SiC-HPN (14.0 GPa) was approximately 10% higher than the equivalently valued YApp of SiC-B, SiC-N, and SiC-SC-1RN. This discrimination in YApp shows that the use of this test method could be insightful because there were no differences among the average Knoop hardnesses of the four SiC grades.

  17. Energy Dissipation and Apparent Viscosity of Semi-solid Metal during Rheological Processes Part Ⅱ: Apparent Viscosity

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study investigated the rheological properties of semi-solid metal. An analytical model of apparent viscosity was built up based on analysis of energy dissipation during rheological processes such as slurry preparing,delivering and model filling. The rheological properties of SSM (semi-solid metal) slurry was described by an analytical model in terms of microstructural parameters, which consist of effective solid fraction, particle size and shape, and flow parameters such as mean velocity, fluctuant velocity and relative velocity between liquid and solid phase. The model was verified in the experiment of A356 alloys with a coaxial double-bucket rheometer. And the maximum relative error between the theoretical value and measured one is less than 10%.The results of experiment and theoretical calculation also indicate that the microstructural parameters and flow parameters are two major factors that affect the apparent viscosity of semi-solid alloys, and fluctuant velocity and relative velocity between liquid and solid phase are the key factors to distinguish between steady and transient rheological properties.

  18. Quantum volume

    Science.gov (United States)

    Ryabov, V. A.

    2015-08-01

    Quantum systems in a mechanical embedding, the breathing mode of a small particles, optomechanical system, etc. are far not the full list of examples in which the volume exhibits quantum behavior. Traditional consideration suggests strain in small systems as a result of a collective movement of particles, rather than the dynamics of the volume as an independent variable. The aim of this work is to show that some problem here might be essentially simplified by introducing periodic boundary conditions. At this case, the volume is considered as the independent dynamical variable driven by the internal pressure. For this purpose, the concept of quantum volume based on Schrödinger’s equation in 𝕋3 manifold is proposed. It is used to explore several 1D model systems: An ensemble of free particles under external pressure, quantum manometer and a quantum breathing mode. In particular, the influence of the pressure of free particle on quantum oscillator is determined. It is shown also that correction to the spectrum of the breathing mode due to internal degrees of freedom is determined by the off-diagonal matrix elements of the quantum stress. The new treatment not using the “force” theorem is proposed for the quantum stress tensor. In the general case of flexible quantum 3D dynamics, quantum deformations of different type might be introduced similarly to monopole mode.

  19. Apparent distribution coefficients of transuranium elements in UK coastal waters

    International Nuclear Information System (INIS)

    The authorized inputs of low-level radioactive waste into the Irish Sea from the British Nuclear Fuels plc reprocessing plant at Sellafield may be used to advantage to study the distribution and behaviour of artificial radionuclides in the marine environment. Apparent distribution coefficients (Ksub(d)) for the transuranium elements Np, Pu, Am and Cm have been determined by the analysis of environmental samples collected from UK coastal waters. The sampling methodology for obtaining suspended sediment-seawater Ksub(d)s by filtration is described and critically evaluated. Artefacts may be introduced in the sample collection stage. Ksub(d) values have also been determined for seabed sediment-interstitial waters and the precautions taken to preserve in-situ chemical conditions are described. Variations in Ksub(d) values are discussed in relation to distance from Sellafield, suspended load, redox conditions and oxidation state changes. (author)

  20. An Apparent Paradox in Verification of Rainfall Estimates.

    Science.gov (United States)

    Ciach, G. J.

    2009-05-01

    A problem that is a source of permanent cognitive confusion in comprehensive evaluations of different rainfall estimates is presented. The problem stems from the existence of two conditional biases (CB) inherent to the uncertainties of the estimates. The two CBs, called "CB type 1" and "CB type 2," are recognized by researchers familiar with the distribution-oriented framework for complete verification of hydrological and meteorological products. Although the mathematical definitions of the two CBs are clear, a reality check reveals that their meaningful interpretation is problematic. It can even result in self-contradictory conclusions suggesting both systematic overestimation and underestimation of strong rainfall by the same rainfall estimation products. A solution to this apparent paradox is discussed. This investigation is based on large data samples of different radar rainfall estimates and the corresponding highly accurate ground reference. Understanding the two CBs, their physical consequences and the fundamental inter-relations between them is essential for informed usage of these uncertainty characteristics.

  1. Apparent diffusion coefficient measurements in progressive supranuclear palsy

    Energy Technology Data Exchange (ETDEWEB)

    Ohshita, T.; Oka, M.; Imon, Y.; Yamaguchi, S.; Mimori, Y.; Nakamura, S. [Hiroshima Univ. (Japan). School of Medicine

    2000-09-01

    We measured the apparent diffusion coefficient (ADC), using diffusion-weighted imaging (DWI) and signal intensity on T2-weighted MRI in the cerebral white matter of patients with progressive supranuclear palsy (PSP) and age-matched normal subjects. In PSP, ADC in the prefrontal and precentral white matter was significantly higher than in controls. There was no significant difference in signal intensity on T2-weighted images. The ADC did correlate with signal intensity. The distribution of the elevation of ADC may be the consequence of underlying pathological changes, such as neurofibrillary tangles or glial fibrillary tangles in the cortex. Our findings suggest that ADC measurement might be useful for demonstrating subtle neuropathological changes. (orig.)

  2. Considerations about the apparent superluminal expansions in astrophysics

    International Nuclear Information System (INIS)

    The ortodox models devised to explain the apparent ''superluminal expansions'' observed in astrophysics, and here briefly summarized and discussed together with th experimental data, do not seem to be to much successful. Especially when confronted with the most recent observations, suggesting complicated expansion patterns, even with possible accelerations. At this point it may be, therefore, of some interest to explore the possible alternative models in which actual superluminal motion take place. To prepare the ground one starts from a variational principle, introduces the elements of a tachyon mechanics within special relativity, and argues about the expected behaviour of tachyonic objects when interacting (gravitationally, for instance) among themselves or with ordinary matter. Then the simplest ''superluminal models'', paying particular attention to the observations which they would give rise to are revie wed and developed. It is concluded that some of them appear to be physically acceptable and are statistically favoured with respect to the ortodox ones

  3. Considerations about the apparent 'superluminal expansions' in astrophysics

    International Nuclear Information System (INIS)

    The orthodox models devised to explain the apparent 'superluminal expansions' observed in astrophysics - and here briefly summarized and discussed together with the experimental data - do not seem to be too much succesful. Especially when confronted with the most recent observations, suggesting complicated expansion patterns, even with possible accelerations. At this point it may be, therefore, of some interest to explore the possible alternative models in which actual Superluminal motions take place. The ground is prepared starting from a variational principle, introducing the elements of a tachyon mechanics within special relativity, and arguing about the expected behaviour of tachyonic objects when interacting (gravitationally, for instance) among themselves or with ordinary matter. Then the simplest 'Superluminal models' are reviewed and developed, paying particular attention to the observations which they would give rise to. Itis concluded that some of them appear to be physically acceptable and are statistically favoured with respect to the orthodox ones. (Author)

  4. Deforestation and apparent extinctions of endemic forest beetles in Madagascar.

    Science.gov (United States)

    Hanski, Ilkka; Koivulehto, Helena; Cameron, Alison; Rahagalala, Pierre

    2007-06-22

    Madagascar has lost about half of its forest cover since 1953 with much regional variation, for instance most of the coastal lowland forests have been cleared. We sampled the endemic forest-dwelling Helictopleurini dung beetles across Madagascar during 2002-2006. Our samples include 29 of the 51 previously known species for which locality information is available. The most significant factor explaining apparent extinctions (species not collected by us) is forest loss within the historical range of the focal species, suggesting that deforestation has already caused the extinction, or effective extinction, of a large number of insect species with small geographical ranges, typical for many endemic taxa in Madagascar. Currently, roughly 10% of the original forest cover remains. Species-area considerations suggest that this will allow roughly half of the species to persist. Our results are consistent with this prediction. PMID:17341451

  5. Apparent diffusion coefficient measurements in progressive supranuclear palsy

    International Nuclear Information System (INIS)

    We measured the apparent diffusion coefficient (ADC), using diffusion-weighted imaging (DWI) and signal intensity on T2-weighted MRI in the cerebral white matter of patients with progressive supranuclear palsy (PSP) and age-matched normal subjects. In PSP, ADC in the prefrontal and precentral white matter was significantly higher than in controls. There was no significant difference in signal intensity on T2-weighted images. The ADC did correlate with signal intensity. The distribution of the elevation of ADC may be the consequence of underlying pathological changes, such as neurofibrillary tangles or glial fibrillary tangles in the cortex. Our findings suggest that ADC measurement might be useful for demonstrating subtle neuropathological changes. (orig.)

  6. A "fair sampling" perspective on an apparent violation of duality

    CERN Document Server

    Bolduc, Eliot; Miatto, Filippo M; Leuchs, Gerd; Boyd, Robert W

    2014-01-01

    In the event in which a quantum mechanical particle can pass from an initial state to a final state along two possible paths, the duality principle states that "the simultaneous observation of wave and particle behavior is prohibited". [M. O. Scully, B.-G. Englert, and H. Walther. Nature, 351:111-116, 1991.] emphasized the importance of additional degrees of freedom in the context of complementarity. In this paper, we show how the consequences of duality change when allowing for biased sampling, that is, postselected measurements on specific degrees of freedom of the environment of the two-path state. Our work contributes to the explanation of previous experimental apparent violations of duality [R. Menzel, D. Puhlmann, A. Heuer, and W. P. Schleich. Proc. Natl. Acad. Sci., 109(24):9314-9319, 2012.] and opens up the way for novel experimental tests of duality.

  7. Random variability explains apparent global clustering of large earthquakes

    Science.gov (United States)

    Michael, A.J.

    2011-01-01

    The occurrence of 5 Mw ≥ 8.5 earthquakes since 2004 has created a debate over whether or not we are in a global cluster of large earthquakes, temporarily raising risks above long-term levels. I use three classes of statistical tests to determine if the record of M ≥ 7 earthquakes since 1900 can reject a null hypothesis of independent random events with a constant rate plus localized aftershock sequences. The data cannot reject this null hypothesis. Thus, the temporal distribution of large global earthquakes is well-described by a random process, plus localized aftershocks, and apparent clustering is due to random variability. Therefore the risk of future events has not increased, except within ongoing aftershock sequences, and should be estimated from the longest possible record of events.

  8. Time course of the apparent diffusion coefficient after cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Ahlhelm, F.; Backens, M.; Reith, W.; Hagen, T. [Department of Neuroradiology, University of Saarland, 66424 Homburg/Saar (Germany); Schneider, G. [Department of Radiology, University of Saarland, 66424 Homburg/Saar (Germany)

    2002-09-01

    The purpose of this study was to evaluate quantitative apparent diffusion changes in the center of infarction by measurement of the apparent diffusion coefficient (ADC), and to investigate the influence of ischemia on the contralateral hemisphere. By diffusion echo-planar imaging (EPI) 52 patients showing cerebral infarction were studied within 5 h to >12 months after onset of clinical symptoms. Using three diffusion gradient strengths (b1=30 s/mm{sup 2}; b2=300 s/mm{sup 2}, b3=1100 s/mm{sup 2}) ADC maps were generated. After onset of ischemia, ADC in the center of infarction was lower than in the contralateral regions of human brain. At first ADC declined for approximately 28 h to a minimum of approximately 150 x 10{sup -8} cm{sup 2}/s. Then the ADC reincreased and reached a ''pseudonormalization'' after approximately 5 days. Chronic infarctions did show much higher ADC values (2000 x 10{sup -8} cm{sup 2}/s) than unaffected areas. Neither localization nor size of infarctions showed a significant influence on this time course. In the center of infarction diffusion is isotropic. Even brain regions of the contralateral hemisphere are influenced by cerebral ischemia. In these regions ADC is higher than for physiological conditions. The ADC also declines especially for the first 2-3 days after onset of symptoms, also followed by reincrease. The ADC calculation enables determination of the onset of infarction more exactly than is possible using only diffusion-weighted imaging. Diffusion in the center of infarction is isotropic; hence, orientation of the diffusion gradients has no significant influence on sensitivity of measurements. The calculation of the ADC ratio based on data derived from the center of infarction and the contralateral hemisphere seems to be critical because the ADC in the unaffected contralateral hemisphere also changes. (orig.)

  9. Time course of the apparent diffusion coefficient after cerebral infarction

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate quantitative apparent diffusion changes in the center of infarction by measurement of the apparent diffusion coefficient (ADC), and to investigate the influence of ischemia on the contralateral hemisphere. By diffusion echo-planar imaging (EPI) 52 patients showing cerebral infarction were studied within 5 h to >12 months after onset of clinical symptoms. Using three diffusion gradient strengths (b1=30 s/mm2; b2=300 s/mm2, b3=1100 s/mm2) ADC maps were generated. After onset of ischemia, ADC in the center of infarction was lower than in the contralateral regions of human brain. At first ADC declined for approximately 28 h to a minimum of approximately 150 x 10-8 cm2/s. Then the ADC reincreased and reached a ''pseudonormalization'' after approximately 5 days. Chronic infarctions did show much higher ADC values (2000 x 10-8 cm2/s) than unaffected areas. Neither localization nor size of infarctions showed a significant influence on this time course. In the center of infarction diffusion is isotropic. Even brain regions of the contralateral hemisphere are influenced by cerebral ischemia. In these regions ADC is higher than for physiological conditions. The ADC also declines especially for the first 2-3 days after onset of symptoms, also followed by reincrease. The ADC calculation enables determination of the onset of infarction more exactly than is possible using only diffusion-weighted imaging. Diffusion in the center of infarction is isotropic; hence, orientation of the diffusion gradients has no significant influence on sensitivity of measurements. The calculation of the ADC ratio based on data derived from the center of infarction and the contralateral hemisphere seems to be critical because the ADC in the unaffected contralateral hemisphere also changes. (orig.)

  10. On the apparent CO2 absorption by alkaline soils

    Directory of Open Access Journals (Sweden)

    X. Chen

    2014-02-01

    Full Text Available Alkaline soils in the Gubantonggut Desert were recently demonstrated socking away large quantities of CO2 in an abiotic form. This demands a better understanding of abiotic CO2 exchange in alkaline sites. Reaction of CO2 with the moisture or dew in the soil was conjectured as a potential mechanism. The main goal of this study is to determine the extent to which the dew deposition modulates Land–Atmosphere CO2 exchange at highly alkaline sites (pH ~ 10. Experiments were conducted at the most barren sites (canopy coverage 2 fluxes were measured using a micro-lysimeters and an automated flux system (LI-COR, Lincoln, Nebraska, USA, respectively. There is an evident increase of dew deposition in nocturnal colder temperatures and decrease in diurnal warmer temperatures. Variations of soil CO2 flux are almost contrary, but the increase in diurnal warmer temperatures is obscure. It was shown that the accumulation and evaporation of dew in the soil motivates the apparent absorption and release of CO2. It was demonstrated that dew amounts in the soil has an exponential relation with the part in Fc beyond explanations of the worldwide utilized Q10 model. Therefore dew deposition in highly alkaline soils exerted a potential CO2 sink and can partly explain the apparent CO2 absorption. This implied a crucial component in the net ecosystem carbon balance (NECB at alkaline sites which occupies approximately 5% of the Earth's land surface (7 million km. Further explorations for its mechanisms and representativeness over other arid climate systems have comprehensive perspectives in the quaternary research.

  11. Reduced central blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik; Bendtsen, Flemming; Sørensen, T I;

    1989-01-01

    was inversely correlated to the systemic vascular resistance (r = -0.49, p less than 0.001), the latter being significantly reduced in the patient group. Patients with cirrhosis apparently are unable to maintain a normal central blood volume. This may be due to arteriolar vasodilation, portosystemic collateral......The pathogenesis of ascites formation in cirrhosis is uncertain. It is still under debate whether the effective blood volume is reduced (underfilling theory) or whether the intravascular compartment is expanded (overflow theory). This problem has not yet been solved because of insufficient tools...... for measuring the central blood volume. We have developed a method that enables us to determine directly the central blood volume, i.e., the blood volume in the heart cavities, lungs, and central arterial tree. In 60 patients with cirrhosis and 16 control subjects the central blood volume was assessed according...

  12. Contribution of Chlorophyll Fluorescence to the Apparent Reflectance of Vegetation

    Science.gov (United States)

    Campbell, P. K. Entcheva; Middleton, E. M.; Kim, M. S.

    2007-01-01

    Current strategies for monitoring the physiologic status of terrestrial vegetation rely on remote sensing reflectance (R) measurements, whi ch provide estimates of relative vegetation vigor based primarily on chlorophyll content. Vegetation chlorophyll fluorescence (CF) offers a non-destructive alternative and a more direct approach for diagnosis of vegetation stress before a significant reduction in chlorophyll content has occurred. Thus, monitoring of vegetation vigor based on CF may allow earlier stress detection and more accurate carbon sequestra tion estimates, than is possible using R data alone. However, the observed apparent vegetation reflectance (Ra) in reality includes contrib utions from both the reflected and fluoresced radiation. The aim of t his study is to determine the relative R and CF fractions contributing to Ra from the vegetation in the red to near-infrared region of the spectrum. The practical objectives of the study are to: 1) evaluate t he relationship between CF and R at the foliar level for corn, soybean, maple; and 2) for corn, determine if the relationship established f or healthy (optimal N) vegetation changes under N defiiency. To obtai n generally applicable results, experimental measurements were conducted on unrelated crop and tree species (maple, soybean and corn), unde r controlled conditions and a gradient of inorganic N fertilization l evels. Optical R spectra and actively induced CF emissions were obtained on the same foliar samples, in conjunction with measurements of p hotosynthetic function, pigment levels, and C and N content. The comm on spectral trends or similarities were examined. On average, 10-20% of apparent R at 685 nm was actually due to CF. The spectral trends in steady and maximum F varied significantly, with Fs (especially red) showing higher ability for species and treatment separation. The relative contribution of ChF to R varied significantly among species, with maple emitting much higher F amounts, as

  13. Earth's Climate Sensitivity: Apparent Inconsistencies in Recent Assessments

    Science.gov (United States)

    Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph; Rodhe, Henning

    2014-12-01

    Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content. This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO2 given in AR5, 1.5-4.5 K/(3.7 W m-2) exceeds the range inferred from the assessed likely range of forcing, 1.2-2.9 K/(3.7 W m-2), where 3.7 W m-2 denotes the forcing for doubled CO2. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.

  14. Massively parallel implementations of theories for apparent motion.

    Science.gov (United States)

    Grzywacz, N M; Yuille, A L

    1988-01-01

    Two solutions for the correspondence problem for long-range motion are investigated. The first is a modification of the Minimal Mapping Theory (S. Ullman: The Interpretation of Visual Motion, MIT Press, Cambridge, 1979) that is implemented by a massively parallel network. In this network, every two units are interconnected, and thus, its convergence is fast and relatively independent of the number of image features. Computer simulations show that our method accounts as well as the Minimal Mapping Theory for apparent-motion phenomena, although some differences exist. Mathematical proofs provide conditions for the convergence of the network. The second 'solution' for the correspondence problem is called the Structural Theory. This theory assumes that the three-dimensional structure of viewed objects does not change fast in time. Then, the theory looks for the correspondence and three-dimensional structure that best fulfill this assumption. A massively parallel network implementation of this theory is also possible. However, its performance is poor due to the high complexity of its solution space. This supports Ullman's (1979) suggestion that the visual system separates the structure-from-motion process into two stages. First, a stage for motion measurement, and then a stage for structure recovery. PMID:3153661

  15. Short-duration radio bursts with apparent extragalactic dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Saint-Hilaire, P. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Benz, A. O.; Monstein, C., E-mail: shilaire@ssl.berkeley.edu [Institute for Astronomy, ETH Zurich, 8093 Zurich (Switzerland)

    2014-11-01

    We present the results of the longest yet undertaken search for apparently extragalactic radio bursts at the Bleien Radio Observatory covering 21,000 hr (898 days). The data were searched for events of less than 50 ms FWHM duration showing a ν{sup –2} drift in the spectrogram characteristic of the delay of radio waves in plasma. We have found five cases suggesting dispersion measures between 350 and 400 cm{sup –3} pc while searching in the range of 75-2000 cm{sup –3} pc. Four of the five events occurred between 10:27 and 11:24 a.m. local civil time. The only exception occurred at night with the full Moon in the beam. It was an event that poorly fits plasma dispersion, but had the characteristics of a solar Type III burst. However, we were not able to confirm that it was a lunar reflection. All events were observed with a log-periodic dipole within 6800 hr, but none with a more directional horn antenna observing the rest of the time. These properties suggest a terrestrial origin of the 'peryton' type reported before. However, the cause of these events remains ambiguous.

  16. Apparent diffusion coefficients of breast tumors. Clinical application

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the usefulness of apparent diffusion coefficient (ADC) for the differential diagnosis of breast tumors and to determine the relation between ADC and tumor cellularity. One hundred and thirty-six female patients (age range, 17-83 years; average age, 51.7 years) with 140 histologically proven breast tumors underwent diffusion-weighted magnetic resonance (MR) imaging (DWI) using the spin-echo echo-planar technique, and the ADCs of the tumors were calculated using 3 different b values, 0, 500, and 1000 s/mm2. The diagnoses consisted of fibroadenoma (FA, n=16), invasive ductal carcinoma, not otherwise specified (IDC, n=117), medullary carcinoma (ME, n=3) and mucinous carcinoma (MU, n=4). Tumor cellularity was calculated from surgical specimens. The ADCs of breast tumors and cellularity were compared between different histological types by analysis of variance and Scheffe's post hoc test. The correlation between tumor cellularity and ADC was analyzed by Pearson correlation test. Significant differences were observed in ADCs between FA and all types of cancers (P2=0.451). The ADC may potentially help in differentiating benign and malignant breast tumors. Tumor ADC correlates inversely with tumor cellularity. (author)

  17. Apparent wavelength dependence of v sin i for Zeta Tauri

    Science.gov (United States)

    Heap, S. R.

    1977-01-01

    It was previously reported that the derived projected rotational velocity (v sin i) of the B shell star, Zeta Tau, appeared to depend on the wavelength of the line used in the analysis. This letter documents the apparent wavelength dependence of v sin i for Zeta Tau in order to provide an observational basis against which quantitative explanations can be tested. A value of 300 km/s is adopted for v sin i on the basis of an examination of the visual line spectrum, particularly the lines of He I at 4026 and 4471 A and Mg II at 4481 A. Analysis of the far-UV resonance lines of Si III at 1206 A and Si IV at 1393 and 1463 A in Copernicus spectrograms of Zeta Tau yields a representative value of no more than 150 km/s for v sin i. Gravity darkening of the star's atmosphere and distention of the atmosphere by rapid differential rotation are considered as possible explanations for the discrepancy between the v sin i values determined from the UV and visual lines.

  18. Isotropic apparent diffusion coefficient mapping of postnatal cerebral development

    International Nuclear Information System (INIS)

    Diffusion-weighted imaging (DWI) allows us to image the motion of tissue water. This has been used to demonstrate acute ischaemia. Diffusion imaging is also sensitive to water movement along neuronal tracts. Our objective was to map brain maturation in vivo using maps of apparent diffusion coefficient (ADC). We studied 22 children without neurological disease aged between 2 and 720 days. MRI was performed at 1.5 tesla. Multislice single-shot echoplanar DWI was performed at b 0 and 1000 s/mm2. ADC maps were generated automatically and measurements were performed in the basal ganglia, frontal and temporal white matter and the pons. There was a decrease over time in water diffusion in the areas examined, most marked in the frontal (0.887-1.898 x 10-3 mm2/s) and temporal (1.077-1.748 x 10-3 mm2/s)lobes. There was little change, after an initial decrease, in the basal ganglia (0.690-1.336 x 10-3 mm2/s). There was a difference in water diffusion between the anterior (0.687-1.581 x 10-3 mm2/s) and posterior (0.533-1.393 x 10-3 mm2/s) pons. These changes correlate well with those observed in progressive myelination: the increased water content probably reflects incomplete myelination and the decrease with time in water motion reflects the increase in myelinated brain. (orig.)

  19. Two Qatari siblings with cystic fibrosis and apparent mineralocorticoid excess

    Directory of Open Access Journals (Sweden)

    Khalid Zahraldin

    2015-01-01

    Full Text Available Cystic fibrosis (CF and apparent mineralocorticoid excess (AME syndrome are both autosomal recessive disorders that result from mutations of specific identified genes for each condition. CF is caused by defects in the Cystic fibrosis trans membrane conductance regulator (CFTR gene which encodes for a protein that functions as a chloride channel and regulates the flow of other ions across the apical surface of epithelial cells. AME is due to the deficiency of 11β-hydroxysteroid dehydrogenase type 2 enzyme (11βHSD2, which is responsible for the peripheral inactivation of cortisol to cortisone. Cortisol excess stimulates the mineralocoritoid receptors (MR resulting in intense sodium retention, hypokalemia and hypertension. We report on a consanguineous Arab family, in which two sibs inherited both CF and AME. Gene testing for AME revealed previously unreported mutation in the 11βHSD2 gene. This report draws attention to the importance of recognizing the possibility of two recessive disorders in the same child in complex consanguineous families. Moreover, it provides a unique opportunity to highlight the implications of the coexistence of two genetic disorders on patient care and genetic counseling of the family.

  20. Apparent thermal conductivity measurements by an unguarded technique

    Science.gov (United States)

    Graves, R. S.; Yarbrough, D. W.; McElroy, D. L.

    An unguarded longitudinal heat flow apparatus for measuring the apparent thermal conductivity (lambda/sub a) of insulations was tested. Heat flow is provided by a horizontal electrically heated Nichrome screen sandwiched between test samples that are bounded by temperature controlled copper plates and 9 cm of mineral fiber insulation. A determinate error analysis shows lambda/sub a/ measurement uncertainty to be less than + or - 1.7% for insulating materials as thin as 3 cm. Three-dimensional thermal modeling indicates negligible error in lambda/sub a/ due to edge loss for insulations up to 7.62 cm thick when the temperature difference across the sample is measured at the screen center. System repeatability and reproducibility were determined to be + or - 0.2%. Differences of lambda/sub a/ results from the screen tester and results from the National Bureau of Standards were 0.1% for a 10-kg/m(3) Calibration Transfer Standard and 0.9% for 127-kg/m(3) fibrous glass board (SRM 1450b). Measurements on fiberglass and rock wool batt insulations showed the dependence of lambda/sub a/ on density, temperature, temperature difference, plate emittance, and heat flow direction. Results obtained for lambda/sub a/ as a function of density at 240C differed by less than 2% from values obtained with a guarded hot plate. It is demonstrated that this simple technique has the accuracy and sensitivity needed for useful lambda/sub a/ measurements on thermal insulating materials.

  1. Age dependence of the renal apparent diffusion coefficient in children

    International Nuclear Information System (INIS)

    Diffusion imaging has proved to be a powerful tool for diagnosing ischemic lesions in the brain, and the technique is now being applied to other organs, including the kidneys. For quantitative studies it is important to define the normal values of the apparent diffusion coefficient (ADC), given the important physiological changes that occur in the kidney during early childhood it is likely that the ADC changes markedly during this period. To evaluate the age dependent changes in the ADC of normal kidneys in the pediatric population. The whole kidney ADC was calculated for 62 pediatric patients on a 1.5-T system using a respiratory-triggered, single-shot diffusion tensor imaging sequence with b values of 50, 200, and 350 mm2/s. The ADC was found to increase with age with the largest increase being in the first year of life, the rate of change being described by a constant plus a power function, specifically 1349+{358.5*{age0.34}}, (P < 0.001). The renal ADC changes significantly during childhood. (orig.)

  2. Severe cytomegalovirus infection in apparently immunocompetent patients: a systematic review

    Directory of Open Access Journals (Sweden)

    Varbobitis Ioannis C

    2008-03-01

    Full Text Available Abstract Background The morbidity and mortality associated with cytomegalovirus (CMV infection in immunocompromised patients (especially in HIV-infected patients and transplant recipients, as well as with congenital CMV infection are well known. In contrast, relatively little attention has been paid to the morbidity and mortality that CMV infection may cause in immunocompetent patients. Methods We reviewed the evidence associated with severe manifestations of CMV infection in apparently immunocompetent patients and the potential role of antiviral treatment for these infections. We searched in PubMed, Scopus, and the Cochrane Library for the period of 1950–2007 to identify relevant articles. Results We retrieved 89 articles reporting on severe CMV infection in 290 immunocompetent adults. Among these reports, the gastrointestinal tract (colitis and the central nervous system (meningitis, encephalitis, transverse myelitis were the most frequent sites of severe CMV infection. Manifestations from other organ-systems included haematological disorders (haemolytic anaemia, thrombocytopenia, thrombosis of the venous or arterial vascular system, ocular involvement (uveitis, and lung disease (pneumonitis. The clinical practice reported in the literature has been to prescribe antiviral treatment for the most severe manifestations of monophasic meningoencephalitis (seizures and coma, ocular involvement, and lung involvement due to CMV. Conclusion Severe life-threatening complications of CMV infection in immunocompetent patients may not be as rare as previously thought.

  3. Image statistics and the perception of apparent motion.

    Science.gov (United States)

    Gilden, D L; Bertenthal, B I; Othman, S

    1990-11-01

    The short- and long-range apparent motion processes are discussed in terms of the statistical properties of images. It is argued that the short-range process, exemplified by the random-dot kinematogram, is primarily sensitive to the dipole statistics, whereas the long-range process, exemplified by illusory occlusion, is treated by the visual system primarily in terms of the tripole and higher statistical correlation functions. The studies incorporate the balanced dot, which is a unique stimulus element that permits high pass filtering while preserving detailed positional information. Low spatial frequencies are shown to be critical for texture segregation in random-dot kinematograms, independent of the grain size or number density of texture elements. Illusory path perception in the long-range process is shown not to require low spatial frequencies, but is sensitive rather to global temporal phase coherency. These results are interpreted in terms of the respective roles of the power and phase spectra in perceptual organization. The construction of balanced dots is discussed in detail. PMID:2148586

  4. Age- and direction-related adaptations of lumbar vertebral trabecular bone with respect to apparent stiffness and tissue level stress distribution

    Institute of Scientific and Technical Information of China (English)

    He Gong; Yubo Fan; Ming Zhang; Ling Qin

    2009-01-01

    The objective of this study was to study the age-related adaptation of lumbar vertebral trabecular bone at the apparent level, as well as the tissue level in three orthog-onal directions. Ninety trabecular specimens were obtained from six normal L4 vertebral bodies of six male cadavers in two age groups, three aged 62 years and three aged 69 years, and were scanned using a high-resolution micro-computed tomography (micro-CT) system, then converted to micro-finite element models to do micro-finite element analyses. The relationship between apparent stiffness and bone volume fraction, and the tissue level von Mises stress distribution for each trabecular specimen when compressed separately in the longitudinal direction, medial-lateral and anterior-posterior directions (transverse directions) were derived and compared between two age groups. The results showed that at the appar-ent level, trabecular bones from 69-year group had stiffer bone structure relative to their volume fractions in all three directions, and in both age groups, changes in bone volume fraction could explain more variations in apparent stiffness in the longitudinal direction than the transverse directions; at the tissue level, aging had little effect on the tissue von Mises stress distributions for the compressions in all the three directions. The novelty of the present study was that it provided quantitative assessments on the age and direction-related adaptation of Chinese male lumbar vertebral trabec-ular bone from two different levels: stiffness at the apparent level and stress distribution at the tissue level. It may help to understand the failure mechanisms and fracture risks of vertebral body associated with aging and direction for the prevention of fracture risks in elder individuals.

  5. Apparent resistivity and spectral induced polarization in the submarine environment

    Directory of Open Access Journals (Sweden)

    HERCULES DE SOUZA

    2001-09-01

    Full Text Available Relatively few investigations have employed electrical methods in the submarine environment, which may be promising for mineral deposits or threatened by environmental problems. We have measured the electric field using both disk and bar electrodes in the sea water at three different levels: sea surface, seven meters deep, and sea bottom at a depth of ten meters, employing a 2 m spacing dipole-dipole array with 7 array spacings of investigation, and 13 values of frequencies at steps of (2N hertz, N = -2, -1, 0, 1, 2,.....10. The measurement allowed the analysis of the electric field as a function of frequency and spacing, and of the spectral induced polarization. Modelling and interpretation of the apparent resistivity yielded a good fit with previous drilling data. Analysis of the spectrum of the complex apparent resistivity and the comparison with equivalent circuits, provided information about the grain size, the mineral composition and the major induced polarization phenomenon occurring below the sea. Therefore the result of the present research show the feasibility of measuring the variation of seawater resistivity in situ, as well as the resistivity of sea bottom sediments.Relativamente poucas investigações têm empregado métodos elétricos no ambiente submarino, o qual pode ser promissor para depósitos minerais ou ameaçado por problemas ambientais. Nós medimos o campo elétrico usando eletrodos em forma de disco e de barra na água do mar, em três níveis distintos: superfície, sete metros de profundidade, e fundo do mar a dez metros de profundidade, empregando um dispositivo dipolo-dipolo com 2m de afastamento, 7 níveis de investigação e 13 valores de freqüência a intervalos de (2N hertz, N = -2, -1, 0, 1, 2, ... 10. A medida permitiu a análise do campo elétrico como uma função de freqüência e afastamento, e da polarização induzida espectral. A modelagem e a interpretação da resistividade aparente se ajustaram bem

  6. Apparent rotation and jazzing in Leviant's Enigma illusion.

    Science.gov (United States)

    Hamburger, Kai

    2007-01-01

    In 1981 Leviant devised Enigma, a figure that elicits perceived rotary motion in the absence of real motion. However, despite its striking appearance there is no good explanation for this motion illusion to date. Gregory (1993 Proceedings of the Royal Society of London B 253 123) pointed out a similarity to MacKay's 'complementary' afterimage in his ray pattern and suggested accommodative fluctuations and small eye movements as a potential origin for these phenomena. Furthermore, Zeki et al (1993 Proceedings of the Royal Society of London B 252 215-222) found PET-activation in response to Enigma in visual area V5 and immediately surrounding areas (called V5 complex) suggesting that the illusory motion could be mediated by the same neurons as real motion. In the experiments reported here, I show that the rotary motion is perceived on coloured as well as achromatic annuli intercepting the radial lines. More importantly, the illusory streaming motion continues to be seen with a cycloplegic lens as well as through a pinhole (ie ruling out transient changes of accommodation), and in the positive after-image (ie in the absence of eye movements). Apparent rotation is strongest with radial inducers impinging at right angles onto the annuli, but persist, although to a lesser degree, when the inducing lines are tilted in opposite directions, non-collinear, or replaced by dotted lines or lines with rounded terminators. For an explanation, the Enigma illusion requires a neural mechanism that uses lines abutting an empty annulus to elicit orthogonal streaming motion in one or the other direction. PMID:17718359

  7. The apparent charge of nanoparticles trapped at a water interface.

    Science.gov (United States)

    Bossa, Guilherme Volpe; Roth, Joseph; Bohinc, Klemen; May, Sylvio

    2016-05-14

    Charged spherical nanoparticles trapped at the interface between water and air or water and oil exhibit repulsive electrostatic forces that contain a long-ranged dipolar and a short-ranged exponentially decaying component. The former are induced by the unscreened electrostatic field through the non-polar low-permittivity medium, and the latter result from the overlap of the diffuse ion clouds that form in the aqueous phase close to the nanoparticles. The magnitude of the long-ranged dipolar interaction is largely determined by the residual charges that remain attached to the air- (or oil-) exposed region of the nanoparticle. In the present work we address the question to what extent the charges on the water-immersed part of the nanoparticle provide an additional contribution to the dipolar interaction. To this end, we model the electrostatic properties of a spherical particle - a nanoparticle or a colloid - that partitions equatorially to the air-water interface, thereby employing nonlinear Poisson-Boltzmann theory in the aqueous solution and accounting for the propagation of the electric field through the interior of the particle. We demonstrate that the apparent charge density on the air-exposed region of the particle, which determines the dipole potential, is influenced by the electrostatic properties in the aqueous solution. We also show that this electrostatic coupling through the particle can be reproduced qualitatively by a simple analytic planar capacitor model. Our results help to rationalize the experimentally observed weak but non-vanishing salt dependence of the forces that stabilize ordered two-dimensional arrays of interface-trapped nanoparticles or colloids. PMID:27049110

  8. Gene Tree Discordance Causes Apparent Substitution Rate Variation.

    Science.gov (United States)

    Mendes, Fábio K; Hahn, Matthew W

    2016-07-01

    Substitution rates are known to be variable among genes, chromosomes, species, and lineages due to multifarious biological processes. Here, we consider another source of substitution rate variation due to a technical bias associated with gene tree discordance. Discordance has been found to be rampant in genome-wide data sets, often due to incomplete lineage sorting (ILS). This apparent substitution rate variation is caused when substitutions that occur on discordant gene trees are analyzed in the context of a single, fixed species tree. Such substitutions have to be resolved by proposing multiple substitutions on the species tree, and we therefore refer to this phenomenon as Substitutions Produced by ILS (SPILS). We use simulations to demonstrate that SPILS has a larger effect with increasing levels of ILS, and on trees with larger numbers of taxa. Specific branches of the species trees are consistently, but erroneously, inferred to be longer or shorter, and we show that these branches can be predicted based on discordant tree topologies. Moreover, we observe that fixing a species tree topology when performing tests of positive selection increases the false positive rate, particularly for genes whose discordant topologies are most affected by SPILS. Finally, we use data from multiple Drosophila species to show that SPILS can be detected in nature. Although the effects of SPILS are modest per gene, it has the potential to affect substitution rate variation whenever high levels of ILS are present, particularly in rapid radiations. The problems outlined here have implications for character mapping of any type of trait, and for any biological process that causes discordance. We discuss possible solutions to these problems, and areas in which they are likely to have caused faulty inferences of convergence and accelerated evolution. PMID:26927960

  9. Solid focal liver lesion characterisation with apparent diffusion coefficient ratios

    International Nuclear Information System (INIS)

    Non-invasive characterisation of focal liver lesions using diffusion-weighted imaging (DWI) has been heavily investigated and has shown substantial overlap between benign and malignant lesions. We have calculated a ratio of lesion to normal liver to determine if it improves accuracy for correct categorisation. All hepatic MRI studies performed between 1st April 2009 and 26th September 2011 were retrospectively reviewed. Patients with solid focal liver lesions in whom a diagnosis could be established and had lesions over 10mm were included. Haemangiomas, cysts and patients with chronic liver disease were excluded. Apparent diffusion coefficient (ADC) values were calculated for each lesion and adjacent normal liver on breath hold DWI. Two hundred fifty-eight studies were performed and 206 were excluded leaving 52 scans and 58 lesions of which 47 were benign and 11 were malignant. The mean ADC value for benign lesions was 1196.6 (two standard deviations (2SD)=±399.9) and of benign liver 1101.5 (2SD=±329.8) with a ratio of benign lesion to benign liver of 1.1005 (2SD=±0.3783). The mean ADC of malignant lesions was 1153.0 (2SD=±604.9) and malignant liver of 1080.7 (2SD=±533.4) giving a malignant lesion to malignant liver ratio of 1.0890 (2SD=±0.4975). None of these results were statistically significant (all P>0.5). DWI is unable to reliably differentiate solid benign lesions from solid malignant lesions.

  10. Infantile Apparent Life-Threatening Events, an Educational Review

    Directory of Open Access Journals (Sweden)

    Hamed Aminiahidashti

    2015-01-01

    Full Text Available Many physicians have received a frantic call from anxious parents stating that their child had stopped breathing, become limp, or turned blue but then had recovered quickly. An apparent life-threatening event (ALTE is defined as “an episode that is frightening to the observer, and is characterized by some combination of apnea, color change, marked change in muscle tone, choking, gagging, or coughing”. The incidence of ALTE is reported to be 0.05% to 6%. The knowledge about the most common causes and factors associated with higher risk of ALTE could be resulted in a more purposeful approach, improving the decision making process, and benefiting both children and parents. The aim of this review article was to report the epidemiology, etiology, evaluation, management, and disposition of ALTE. Infants with an ALTE might present no signs of acute illness and are commonly managed in the emergency settings that often require significant medical attention; hence, the emergency medicine personnel should be aware of the its clinical importance. There is no specific treatment for ALTE; therefore, the clinical evaluations should be focused on the detection of the underlying causes, which will define the outcomes and prognosis. ALTE is a confusing entity, representing a constellation of descriptive symptoms and signs; in other words, it is not a diagnosis. There are multiple possible etiologies and difficulties in evaluating and managing infants with these events, which are challenges to primary care physicians, emergency medicine specialists, and subspecialty pediatricians. The evaluation of these events in infants includes a detailed history, appropriate physical examination, diagnostic tests guided by obtained clues from the history and physical examination, and observation in the emergency department.

  11. Site Environmental Report for 2009, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Suying

    2010-08-19

    Volume II of the Site Environmental Report for 2009 is provided by Ernest Orlando Lawrence Berkeley National Laboratory as a supplemental appendix to Volume I, which contains the body of the report. Volume II contains the environmental monitoring and sampling data used to generate summary results of routine and nonroutine sampling at the Laboratory, except for groundwater sampling data, which may be found in the reports referred to in Chapter 4 of Volume I. The results from sample collections are more comprehensive in Volume II than in Volume I: for completeness, all results from sample collections that began or ended in calendar year (CY) 2009 are included in this volume. However, the samples representing CY 2008 data have not been used in the summary results that are reported in Volume I. (For example, although ambient air samples collected on January 6, 2009, are presented in Volume II, they represent December 2008 data and are not included in Table 4-2 in Volume I.) When appropriate, sampling results are reported in both conventional and International System (SI) units. For some results, the rounding procedure used in data reporting may result in apparent differences between the numbers reported in SI and conventional units. (For example, stack air tritium results reported as < 1.5 Bq/m3 are shown variously as < 39 and < 41 pCi/m3. Both of these results are rounded correctly to two significant digits.)

  12. Sonographic Quantification of Ovarian Volumes in an adult Nigeria population

    OpenAIRE

    Dr. Nzotta Christian; Ugwu Anthony Chukwuka; Mr. Eze Joseph

    2009-01-01

    This study was conducted to establish the normal values of ovarian volumes in this locality. A convenience sample of 141 apparently and gynecologically healthy and non pregnant females was studied using transabdominal sonography. The length, width and anteroposterior dimensions of both the right and left ovaries were measured. Volumes of the ovaries were determined using the prolate ellipsoid formula. The mean ovarian volumes were found to be a 9.5cm3 and 10.cm3 for the right and left ovari...

  13. The apparency hypothesis applied to a local pharmacopoeia in the Brazilian northeast

    OpenAIRE

    Lozano, Alejandro; de Araújo, Elcida Lima; Medeiros, Maria Franco Trindade; Albuquerque, Ulysses Paulino

    2014-01-01

    Background Data from an ethnobotanical study were analyzed to see if they were in agreement with the biochemical basis of the apparency hypothesis based on an analysis of a pharmacopeia in a rural community adjacent to the Araripe National Forest (Floresta Nacional do Araripe - FLONA) in northeastern Brazil. The apparency hypothesis considers two groups of plants, apparent and non-apparent, that are characterized by conspicuity for herbivores (humans) and their chemical defenses. Methods This...

  14. Phase-Contrast MRI and CFD Modeling of Apparent 3He Gas Flow in Rat Pulmonary Airways

    International Nuclear Information System (INIS)

    Phase-contrast (PC) magnetic resonance imaging (MRI) with hyperpolarized 3He is potentially useful for developing and testing patient-specific models of pulmonary airflow. One challenge, however, is that PC-MRI provides apparent values of local 3He velocity that not only depend on actual airflow but also on gas diffusion. This not only blurs laminar flow patterns in narrow airways but also introduces anomalous airflow structure that reflects gas-wall interactions. Here, both effects are predicted in a live rat using computational fluid dynamics (CFD), and for the first time, simulated patterns of apparent 3He gas velocity are compared with in-vivo PC-MRI. Results show (1) that correlations (R2) between measured and simulated airflow patterns increase from 0.23 to 0.79 simply by accounting for apparent 3He transport, and that (2) remaining differences are mainly due to uncertain airway segmentation and partial volume effects stemming from relatively coarse MRI resolution. Higher-fidelity testing of pulmonary airflow predictions should therefore be possible with future imaging improvements.

  15. Phase-Contrast MRI and CFD Modeling of Apparent 3He Gas Flow in Rat Pulmonary Airways

    Energy Technology Data Exchange (ETDEWEB)

    Minard, Kevin R.; Kuprat, Andrew P.; Kabilan, Senthil; Jacob, Rick E.; Einstein, Daniel R.; Carson, James P.; Corley, Richard A.

    2012-08-01

    Phase-contrast (PC) magnetic resonance imaging (MRI) with hyperpolarized 3He is potentially useful for developing and testing patient-specific models of pulmonary airflow. One challenge, however, is that PC-MRI provides apparent values of local 3He velocity that not only depend on actual airflow but also on gas diffusion. This not only blurs laminar flow patterns in narrow airways but also introduces anomalous airflow structure that reflects gas-wall interactions. Here, both effects are predicted in a live rat using computational fluid dynamics (CFD), and for the first time, simulated patterns of apparent 3He gas velocity are compared with in-vivo PC-MRI. Results show (1) that correlations (R2) between measured and simulated airflow patterns increase from 0.23 to 0.79 simply by accounting for apparent 3He transport, and that (2) remaining differences are mainly due to uncertain airway segmentation and partial volume effects stemming from relatively coarse MRI resolution. Higher-fidelity testing of pulmonary airflow predictions should therefore be possible with future imaging improvements.

  16. Contribution of chlorophyll fluorescence to the apparent vegetation reflectance

    International Nuclear Information System (INIS)

    Current strategies for monitoring the physiologic status of terrestrial vegetation rely on remote sensing reflectance data, which provide estimates of vigor based primarily on chlorophyll content. Chlorophyll fluorescence (ChlF) measurements offer a non-destructive alternative and a more direct approach for diagnosis of vegetation stress before a significant reduction in chlorophyll content has occurred. Thus, technology based on ChlF may allow more accurate carbon sequestration estimates and earlier stress detection than is possible when using reflectance data alone. However, the observed apparent vegetation reflectance (Ra) in reality includes contributions from both the reflected and fluoresced radiation. The aim of this study is to determine the relative contributions of reflectance and ChlF fractions to Ra in the red to near-infrared region (650-800 nm) of the spectrum. The practical objectives of the study are to: 1) evaluate the relationship between ChlF and reflectance at the foliar level for corn, soybean and maple; and 2) for corn, determine if the relationship established for healthy vegetation changes under nitrogen (N) deficiency. To obtain generally applicable results, experimental measurements were conducted on unrelated crop and tree species (corn, soybean and maple) under controlled conditions and a gradient of inorganic N fertilization levels. Optical reflectance spectra and actively induced ChlF emissions were collected on the same foliar samples, in conjunction with measurements of photosynthetic function, pigment levels, and carbon (C) and N content. The spectral trends were examined for similarities. On average, 10-20% of Ra at 685 nm was actually due to ChlF. The spectral trends in steady state and maximum fluorescence varied significantly, with steady state fluorescence (especially red, 685 nm) showing higher ability for species and treatment separation. The relative contribution of ChlF to Ra varied significantly among species, with maple

  17. Renormalized Volume

    CERN Document Server

    Gover, A Rod

    2016-01-01

    For any conformally compact manifold with hypersurface boundary we define a canonical renormalized volume functional and compute an explicit, holographic formula for the corresponding anomaly. For the special case of asymptotically Einstein manifolds, our method recovers the known results. The anomaly does not depend on any particular choice of regulator, but the coefficients of divergences do. We give explicit formulae for these divergences valid for any choice of regulating hypersurface; these should be relevant to recent studies of quantum corrections to entanglement entropies. The anomaly is expressed as a conformally invariant integral of a local Q-curvature that generalizes the Branson Q-curvature by including data of the embedding. In each dimension this canonically defines a higher dimensional generalization of the Willmore energy/rigid string action. We show that the variation of these energy functionals is exactly the obstruction to solving a singular Yamabe type problem with boundary data along the...

  18. Effects of formoterol in apparently poorly reversible chronic obstructive pulmonary disease.

    Science.gov (United States)

    Maesen, B L; Westermann, C J; Duurkens, V A; van den Bosch, J M

    1999-05-01

    This randomized, double-blind, placebo-controlled, crossover study was designed to investigate the effects of the long-acting beta2-adrenoreceptor agonist formoterol fumarate in 12 current or exsmokers having chronic obstructive pulmonary disease, with a mean forced expiratory volume in one second (FEV1) 47% of predicted, poorly reversible (5.1% pred) after terbutaline sulphate inhalation. After inhaling a single dose of formoterol (6 or 24 microg), or placebo via Turbuhaler, FEV1 and pulmonary function parameters measured during quiet breathing (work of breathing (WoB) and airway resistance (Raw)) were recorded over 12 h on three test days. Immediate changes in FEV1 were modest, although each dose of formoterol caused a response >12% pred within 10 min in one subject. Compared to placebo, both doses of formoterol induced a clinically and statistically relevant improvement in WoB (>25%) and Raw (>20%), which occurred within 10 min and lasted over a period of 12 h (p < or = 0.02, analysis of variance). Thus, inhaled formoterol causes long-lasting lung functional improvements in apparently poorly reversible chronic obstructive pulmonary disease. Additional lung function measurements during quiet breathing after forced expiration tests may be useful in such patients to assess beneficial effects of bronchodilators. PMID:10414411

  19. Improvised Levelset method for segmentation and grading of brain tumors in dynamic contrast susceptibility and apparent diffusion coefficient magnetic resonance images

    Directory of Open Access Journals (Sweden)

    Vijayakumar Chinnadurai

    2010-05-01

    Full Text Available A novel Neuro – level set algorithm is proposed and evaluated for simultaneous segmentation and grading of brain tumors. The algorithm utilizes vascular and cellular information provided by the reconstructed images of dynamic contrast susceptibility magnetic resonance images and apparent diffusion coefficient images. The reconstructed images are relative cerebral blood volume (rCBV image, time to peak (TTP image and percentage of base at peak (PBP image along with apparent diffusion coefficient (ADC maps. The proposed neural - levelset algorithm utilizes a neural block to provide the speed image for the levelset methods. In this study, two different architectures of levelset method have been implemented and their results are compared. The results show that the proposed Neuro- Levelset method performs better in differentiating the tumor, edema,necrosis in reconstructed images of dynamic contrast susceptibility magnetic resonance images and apparent diffusion coefficient MR images.

  20. Direct Volume Rendering of Curvilinear Volumes

    Science.gov (United States)

    Vaziri, Arsi; Wilhelms, J.; Challinger, J.; Alper, N.; Ramamoorthy, S.; Kutler, Paul (Technical Monitor)

    1998-01-01

    Direct volume rendering can visualize sampled 3D scalar data as a continuous medium, or extract features. However, it is generally slow. Furthermore, most algorithms for direct volume rendering have assumed rectilinear gridded data. This paper discusses methods for using direct volume rendering when the original volume is curvilinear, i.e. is divided into six-sided cells which are not necessarily equilateral hexahedra. One approach is to ray-cast such volumes directly. An alternative approach is to interpolate the sample volumes to a rectilinear grid, and use this regular volume for rendering. Advantages and disadvantages of the two approaches in terms of speed and image quality are explored.

  1. On the volume inside old black holes

    CERN Document Server

    Christodoulou, Marios

    2016-01-01

    Black holes that have nearly evaporated are often thought of as small objects, due to their tiny exterior area. However, the horizon bounds large spacelike hypersurfaces. A compelling geometric perspective on the evolution of the interior geometry was recently shown to be provided by a generally covariant definition of the volume inside a black hole using maximal surfaces. In this article, we expand on previous results and show that finding the maximal surfaces in an arbitrary spherically symmetric spacetime is equivalent to a 1+1 geodesic problem. We then study the effect of Hawking radiation on the volume by computing the volume of maximal surfaces inside the apparent horizon of an evaporating black hole as a function of time at infinity: while the area is shrinking, the volume of these surfaces grows monotonically with advanced time, up to when the horizon has reached Planckian dimensions. The physical relevance of these results for the information paradox and the remnant scenarios are discussed.

  2. Nano Reviews in its 4th Volume

    OpenAIRE

    Biju, Vasudevanpillai

    2013-01-01

    Nano Reviews - now in its 4th volume - is a unique Open Access international journal which publishes articles in the fields of nanoscience, nanotechnology, nanobiotechnology, and single-molecule research, and has successfully published cutting-edge research results and reviews in these areas over the past three years (vols. 1-3). The importance of nanoscience and nanotechnology for future technology and health care is now well recognized, which is apparent from the ever-accelerating growth of...

  3. Apparent diffusion coefficient of hyperpolarized (3)He with minimal influence of the residual gas in small animals.

    Science.gov (United States)

    Carrero-González, L; Kaulisch, T; Ruiz-Cabello, J; Pérez-Sánchez, J M; Peces-Barba, G; Stiller, D; Rodríguez, I

    2012-09-01

    The apparent diffusion coefficient (ADC) of hyperpolarized (HP) gases is a parameter that reflects changes in lung microstructure. However, ADC is dependent on many physiological and experimental variables that need to be controlled or specified in order to ensure the reliability and reproducibility of this parameter. A single breath-hold experiment is desirable in order to reduce the amount of consumed HP gas. The application of a positive end-expiratory pressure (PEEP) causes an increase in the residual gas volume. Depending on the applied PEEP, the ratio between the incoming and residual gas volumes will change and the ADC will vary, as long as both gases do not have the same diffusion coefficient. The most standard method for human applications uses air for breathing and a bolus of pure HP (3)He for MRI data acquisition. By applying this method in rats, we have demonstrated that ADC values are strongly dependent on the applied PEEP, and therefore on the residual gas volume in the lung. This outcome will play an important role in studies concerning certain diseases, such as emphysema, which is characterized by an increase in the residual volume. Ventilation with an oxygen-helium mixture (VOHeM) is a proposed single breath-hold method that uses two different gas mixtures (O(2)-(4)He for ventilation and HP (3)He-N(2) for imaging). The concentration of each gas in its respective mixture was calculated in order to obtain the same diffusion coefficient in both mixtures. ADCs obtained from VOHeM are independent of PEEP, thus minimizing the effect of the different residual volumes. PMID:22275333

  4. Functional Apparent Moduli (FAMs) as Predictors of Oral Implant Osseointegration Dynamics

    OpenAIRE

    Chang, Po-Chun; Seol, Yang-Jo; Kikuchi, Noboru; Goldstein, Steven A.; Giannobile, William V.

    2010-01-01

    At present, limited functional data exists regarding the application and use of biomechanical and imaging technologies for oral implant osseointegration assessment. The objective of this investigation was to determine the functional apparent moduli (FAMs) that could predict the dynamics of oral implant osseointegration. Using an in vivo dental implant osseous healing model, two FAMs, functional bone apparent modulus (FBAM) and composite tissue apparent modulus (FCAM), of the selected peri-imp...

  5. Volumes in Hyperbolic Space

    OpenAIRE

    Laternser, Christina

    2011-01-01

    This paper focuses on the investigation of volumes of large Coxeter hyperbolic polyhedron. First, the paper investigates the smallest possible volume for a large Coxeter hyperbolic polyhedron and then looks at the volume of pyramids with one vertex at infinity.

  6. Cosmological thermodynamics with Hawking temperature on the apparent horizon and Unruh temperature of the fluid: Some interesting consequences

    Science.gov (United States)

    Saha, Subhajit

    2016-06-01

    Thermodynamics on the cosmological apparent horizon of a flat Friedmann-Lemaitre-Robertson-Walker metric has been investigated with Bekenstein entropy and Hawking temperature on the horizon, and Unruh temperature for the fluid inside the horizon. This temperature is experienced by a radial comoving observer infinitesimally close to the horizon due to the pressure exerted by the fluid bounded by the horizon. An expression for the entropy of the fluid has been obtained which is found to be proportional to the volume of the thermodynamic system which implies that the Unruh temperature of the fluid is inconsistent with the holographic principle. Further, we have been able to find an expression for the effective entropy of the system. Finally, assuming a barotropic equation of state p=wρ (w constant) for the fluid, it has been shown that the generalized second law holds good for a non-phantom w, while thermodynamic equilibrium is never possible for such a scenario.

  7. Cosmological thermodynamics with Hawking temperature on the apparent horizon and Unruh temperature of the fluid: Some interesting consequences

    CERN Document Server

    Saha, Subhajit

    2016-01-01

    Thermodynamics on the cosmological apparent horizon of a flat Friedmann-Lemaitre-Robertson-Walker metric has been investigated with Bekenstein entropy and Hawking temperature on the horizon, and Unruh temperature for the fluid inside the horizon. This temperature is experienced by a radial comoving observer infinitesimally close to the horizon due to the pressure exerted by the fluid bounded by the horizon. An expression for the entropy of the fluid has been obtained which is found to be proportional to the volume of the thermodynamic system which implies that the Unruh temperature of the fluid is inconsistent with the holographic principle. Further, we have been able to find an expression for the effective entropy of the system. Finally, assuming a barotropic equation of state $p=w\\rho$ ($w$ constant) for the fluid, it has been shown that the generalized second law holds good for a non-phantom w, while thermodynamic equilibrium is never possible for such a scenario.

  8. Financial Barriers for Students with Non-Apparent Disabilities within Canadian Postsecondary Education

    Science.gov (United States)

    Chambers, Tony; Bolton, Melissa; Sukhai, Mahadeo A.

    2013-01-01

    This study examined the education-related debt, sources of debt, and the process of acquiring accommodations for students with non-apparent (such as learning disabilities and mental health disabilities) and apparent disabilities in Canadian postsecondary education. A third group emerged during analyses, students with medical disabilities, which…

  9. Equipartition of energy and the first law of thermodynamics at the apparent horizon

    OpenAIRE

    Shu, Fu-Wen; Gong, Yungui

    2010-01-01

    We apply the holographic principle and the equipartition law of energy to the apparent horizon of a Friedmann-Robertson-Walker universe and derive the Friedmann equation describing the dynamics of the universe. We also show that the equipartition law of energy can be interpreted as the first law of thermodynamics at the apparent horizon.

  10. Pattern of lung volumes in patients with sighing breathing.

    OpenAIRE

    Aljadeff, G.; Molho, M; I. Katz; Benzaray, S.; Yemini, Z.; Shiner, R. J.

    1993-01-01

    BACKGROUND--Sighing breathing is observed in subjects suffering from anxiety with no apparent organic disease. METHODS--Lung volumes and expiratory flow rates were measured in 12 patients with a sighing pattern of breathing and in 10 normal subjects matched for age, gender, and anthropometric data. In both groups the measurements were made by spirographic and plethysmographic techniques. In normal subjects functional residual capacity (FRC) and residual volume (RV) were measured during normal...

  11. Anomalous volume change of gramicidin A in ethanol solutions

    Science.gov (United States)

    Derechin, M.; Hayashi, D. M.; Jordan, B. E.

    1975-01-01

    Results of studies aimed at clarifying the failure of gramicidin A (GA) to sediment in early experiments are analyzed. In the present work, no sedimentation was observed in pure pentanol or ethanol, while normal sedimentation was observed in ethanol-water mixtures. It is concluded that GA exists in two conformations that differ in volume. Since the apparent specific volume in absolute ethanol sinks to its lowest values on increasing concentration, the GA molecule probably unfolds completely in conditions favorable for dimerization.

  12. On temporal and spatial distribution of seismic apparent stresses in Yunnan area

    Institute of Scientific and Technical Information of China (English)

    QIN Jia-zheng; QIAN Xiao-dong

    2006-01-01

    motion is applied to a detailed study on the temporal and spatial distribution of the seismic apparent stresses (σa)for the moderate and small earthquakes and two aftershock sequences in Yunnan area. The results show that there exists an obvious non-homogeneity for the seismic apparent stresses in the spatial distribution. The concentrated regions of the high apparent stresses are related to the active places of the moderate and small earthquakes. Before the Dayao M=6.2 earthquake, there was a period in which the apparent stresses were high and the value was 5times of the average value, 0.25 MPa. The relatively high values of apparent stresses distribute around the epicentral area of the major shock and nearby. It indicates that the variation characteristics of the apparent stresses can be taken as a new kind of criterion for the earthquake-risk forecast. Usually the ratio of the apparent stresses of the aftershock sequence σaA to the ones σaM of main shock is less than 1.0.

  13. Studies on the interactions of diglycine and triglycine with polyethylene glycol 400 in aqueous solutions by density and ultrasound speed measurements

    International Nuclear Information System (INIS)

    Highlights: ► Di- and tri-glycine in aqueous PEG400 solutions were investigated thermodynamically. ► Density and ultrasound speed of glycine oligomer-PEG400-water systems were measured. ► Apparent molar volumes and isentropic compressions were calculated. ► Apparent molar isobaric expansions were derived. ► Results were interpreted in terms of water–glycine oligomer-PEG400 interactions. -- Abstract: Density and ultrasound speed were measured accurately for diglycine + water, triglycine + water, diglycine + water-polyethylene glycol 400 (PEG400) and triglycine + water-PEG400 solutions at T = (293.15, 298.15, 303.15 and 308.15) K. The results were used in evaluating thermodynamic properties as apparent molar volumes (VØ) and apparent molar isentropic compressions (KSΦ) of diglycine and triglycine in water and in PEG400 solutions. Infinite dilution values of these parameters, VoØ, and KoSΦ, were obtained from their plots as a function of molality by extrapolation and have been utilized in obtaining transfer volumes and transfer compressions at infinite dilution. All transfer volumes and transfer compressions were found to increase with increasing molality of PEG400. Apparent molar isobaric expansions were derived from the temperature dependence of VØ values at infinite dilution and at finite concentrations. All the results were interpreted in terms of solute (diglycine or triglycine) and co-solute (PEG400) and solvent (H2O) interactions

  14. Isometric stress in cardiovascular magnetic resonance - a simple and easily replicable method of assessing cardiovascular differences not apparent at rest

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, Kristian H.; Jones, Alexander; Steeden, Jennifer A.; Taylor, Andrew M.; Muthurangu, Vivek [UCL Centre for Cardiovascular MR, UCL Institute of Cardiovascular Science, Level 6 Old Nurses Home, Cardiorespiratory Unit, Great Ormond Street Hospital for Children, London (United Kingdom)

    2016-04-15

    Isometric exercise may unmask cardiovascular disease not evident at rest, and cardiovascular magnetic resonance (CMR) imaging is proven for comprehensive resting assessment. This study devised a simple isometric exercise CMR methodology and assessed the hemodynamic response evoked by isometric exercise. A biceps isometric exercise technique was devised for CMR, and 75 healthy volunteers were assessed at rest, after 3-minute biceps exercise, and 5-minute of recovery using: (1) blood pressure (BP) and (2) CMR measured aortic flow and left ventricular function. Total peripheral resistance (SVR) and arterial compliance (TAC), cardiac output (CO), left ventricular volumes and function (ejection fraction, stroke volume, power output), blood pressure (BP), heart rate (HR), and rate pressure product were assessed at all time points. Image quality was preserved during stress. During exercise there were increases in CO (+14.9 %), HR (+17.0 %), SVR (+9.8 %), systolic BP (+22.4 %), diastolic BP (+25.4 %) and mean BP (+23.2 %). In addition, there were decreases in TAC (-22.0 %) and left ventricular ejection fraction (-6.3 %). Age and body mass index modified the evoked response, even when resting measures were similar. Isometric exercise technique evokes a significant cardiovascular response in CMR, unmasking physiological differences that are not apparent at rest. (orig.)

  15. Apparent linear attenuation coefficients in phase contrast X-ray tomography

    International Nuclear Information System (INIS)

    In the inline phase contrast X-ray tomography the reconstructed apparent linear attenuation coefficient values may be greatly larger than sample's linear attenuation coefficients or even be negative. In this work we present a general formula to quantitatively relate the apparent linear attenuation coefficient values in cone-beam phase contrast tomography to sample's linear attenuation coefficients and refractive indices. This formula overcomes the gross inaccuracy of the existing formula in the literature in analyzing high-resolution phase contrast tomography, and it will be useful for correctly interpreting and quantifying the apparent linear attenuation coefficients in cone-beam X-ray phase contrast tomography.

  16. Tritium/Helium-3 Apparent Ages of Shallow Ground Water, Portland Basin, Oregon, 1997-98

    Science.gov (United States)

    Hinkle, Stephen R.

    2009-01-01

    Water samples for tritium/helium-3 age dating were collected from 12 shallow monitoring wells in the Portland basin, Oregon, in 1997, and again in 1998. Robust tritium/helium-3 apparent (piston-flow) ages were obtained for water samples from 10 of the 12 wells; apparent ages ranged from 1.1 to 21.2 years. Method precision was demonstrated by close agreement between data collected in 1997 and 1998. Tritium/helium-3 apparent ages generally increase with increasing depth below the water table, and agree well with age/depth relations based on assumptions of effects of recharge rate on vertical ground-water movement.

  17. Apparent size contrasts of retinal images and size constancy as determinants of the moon illusion.

    Science.gov (United States)

    Smith, O W; Smith, P C; Geist, C C; Zimmermann, R R

    1978-06-01

    Kaufman and Rock (1962) and Rock and Kaufman (1962) concluded that the moon illusion is a function of and attributable to apparent distance. They also reported a large framing effect as an exception. Analysis of the effect suggests two components which can account for the illusion independently of apparent distance. These are apparent size contrasts of visual images of discriminable features or objects of the earth with the moon's image and size constancy of the features or objects plus the interactions of the two. Apparent distances to horizons are always a consequence of the necessary conditions for the illusion. They are related to the illusion but are not a determinant of it. PMID:673635

  18. An apparent inconsistency between the Dyson and renormalization group equations in QCD

    International Nuclear Information System (INIS)

    We show that there is an apparent inconsistency between the renormalization group and Dyson equations for the fermion propagator in QCD except in the special QED-like gauge. This has some bearing on the electromagnetic mass shift problem. (author)

  19. The apparent fine-tuning of the cosmological, gravitational and fine structure constants

    Science.gov (United States)

    Eaves, Laurence

    2016-02-01

    A numerical coincidence relating the values of the cosmological, gravitational and electromagnetic fine structure constants is presented and discussed in relation to the apparent anthropic fine-tuning of these three fundamental constants of nature.

  20. A Self-Alignment Algorithm for SINS Based on Gravitational Apparent Motion and Sensor Data Denoising

    OpenAIRE

    Yiting Liu; Xiaosu Xu; Xixiang Liu; Yiqing Yao; Liang Wu; Jin Sun

    2015-01-01

    Initial alignment is always a key topic and difficult to achieve in an inertial navigation system (INS). In this paper a novel self-initial alignment algorithm is proposed using gravitational apparent motion vectors at three different moments and vector-operation. Simulation and analysis showed that this method easily suffers from the random noise contained in accelerometer measurements which are used to construct apparent motion directly. Aiming to resolve this problem, an online sensor data...

  1. Prevalence of upper airway obstruction in patients with apparently asymptomatic euthyroid multi nodular goitre

    OpenAIRE

    Menon, Sunil K.; Jagtap, Varsha S.; Vijaya Sarathi; Lila, Anurag R.; Bandgar, Tushar R.; Menon, Padmavathy S; Nalini S. Shah

    2011-01-01

    Aims: To study the prevalence of upper airway obstruction (UAO) in "apparently asymptomatic" patients with euthyroid multinodular goitre (MNG) and find correlation between clinical features, UAO on pulmonary function test (PFT) and tracheal narrowing on computerised tomography (CT). Materials and Methods: Consecutive patients with apparently asymptomatic euthyroid MNG attending thyroid clinic in a tertiary centre underwent clinical examination to elicit features of UAO, PFT, and CT of neck an...

  2. Apparent Contact Angle and Contact Angle Hysteresis on Liquid Infused Surfaces

    OpenAIRE

    Semprebon, Ciro; McHale, Glen; Kusumaatmaja, Halim

    2016-01-01

    We theoretically investigate the apparent contact angle and contact angle hysteresis of a droplet placed on a liquid infused surface. We show that the apparent contact angle is not uniquely defined by material parameters, but also has a strong dependence on the relative size between the droplet and its surrounding wetting ridge formed by the infusing liquid. We derive a closed form expression for the contact angle in the limit of vanishing wetting ridge, and compute the correction for small b...

  3. Apparent Linear Attenuation Coefficients in Phase Contrast X-Ray Tomography

    OpenAIRE

    Yan, Aimin; Wu, Xizeng

    2011-01-01

    In the inline phase contrast x-ray tomography the reconstructed apparent linear attenuation coefficient values may be greatly larger than sample’s linear attenuation coefficients or even be negative. In this work we present a general formula to quantitatively relate the apparent linear attenuation coefficient values in cone-beam phase contrast tomography to sample’s linear attenuation coefficients and refractive indices. This formula overcomes the gross inaccuracy of the existing formula in t...

  4. Comparison between apparent viscosity related to irradiation dose for corn starch and black pepper

    OpenAIRE

    Oprita N.; Ferdes O.S.; Casandroiu T.

    1999-01-01

    Dose-effect relationship was studied in the rheoviscometric behaviour of geliffied suspensions of irradiated corn starch and black pepper, as the variation of the apparent viscosity and the shear stress related to the dose. Irradiation has been performed up to 16 kGy. Black pepper was ground and sieved to three particle sizes to analyse also the influence of particle size on the apparent viscosity variation by dose. The rheoviscometric measu- rements have been carried out by a rotationary vis...

  5. Apparent viscosity of human blood in a high static magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Haik, Yousef E-mail: haik@eng.fsu.edu; Pai, Vinay; Chen Chingjen

    2001-07-01

    This study investigates the apparent additive viscosity due to magnetic effects on the human blood. Experimental results show that blood flow rate under gravity decreases by 30% when subjected to a high magnetic field of 10 T. The decrease in the flow rate is due to an increase in the apparent viscosity of the blood due to the magnetic field. A correlation describing the viscosity of blood under these conditions is introduced which depends on the Langevin function and parameters.

  6. Ovarian volume throughout life

    DEFF Research Database (Denmark)

    Kelsey, Thomas W; Dodwell, Sarah K; Wilkinson, A Graham;

    2013-01-01

    cancer. To date there is no normative model of ovarian volume throughout life. By searching the published literature for ovarian volume in healthy females, and using our own data from multiple sources (combined n=59,994) we have generated and robustly validated the first model of ovarian volume from...... to about 2.8 mL (95% CI 2.7-2.9 mL) at the menopause and smaller volumes thereafter. Our model allows us to generate normal values and ranges for ovarian volume throughout life. This is the first validated normative model of ovarian volume from conception to old age; it will be of use in the...

  7. Multivariate volume rendering

    Energy Technology Data Exchange (ETDEWEB)

    Crawfis, R.A.

    1996-03-01

    This paper presents a new technique for representing multivalued data sets defined on an integer lattice. It extends the state-of-the-art in volume rendering to include nonhomogeneous volume representations. That is, volume rendering of materials with very fine detail (e.g. translucent granite) within a voxel. Multivariate volume rendering is achieved by introducing controlled amounts of noise within the volume representation. Varying the local amount of noise within the volume is used to represent a separate scalar variable. The technique can also be used in image synthesis to create more realistic clouds and fog.

  8. Communication speaks volumes.

    Science.gov (United States)

    Wixey, Amy

    2016-07-20

    As a learning disability nursing student, it became apparent during formal and informal learning that those studying adult nursing had misconceptions about nursing people with a learning disability. PMID:27440359

  9. Layered volume splatting

    OpenAIRE

    Schlegel, P.; Pajarola, R.

    2009-01-01

    We present a new layered, hardware-accelerated splatting algorithm for volume rendering. Layered volume splatting features the speed benefits of fast axis-aligned pre-classified sheet-buffer splatting while at the same time exhibiting display quality comparable to high-quality post-classified view-aligned sheet-buffer splatting. Additionally, we enhance the quality by using a more accurate approximation of the volume rendering integral. Commonly, the extinction coefficient of the volume r...

  10. CELL VOLUME CONFERENCES

    OpenAIRE

    V. Štrbák

    2016-01-01

    This mini-review describes the history of cell volume conferences with the emphasis on the research of cell volume sensitive peptide exocytosis initiated by Prof. Monte A. Greer as well as the recent achievements on the study of the mechanisms of cell volume adjustment and their implications in the regulation of metabolism, gene expression, cell proliferation and death.

  11. The apparent contact angle of water droplet on the micro-structured hydrophobic surface

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The apparent contact angle of Cassie-Baxter state water droplets can be calculated by the existing theoretical formula, but due to the defects of the micro-structured hydrophobic surface and some inevitable tiny disturbances in the experiment, Cassie-Baxter state water droplets will appear partly in Wenzel state, that is, the mixed state water droplets. In this paper, apparent contact angles of Cassie-Baxter state and mixed state water droplets on micro-structured hydrophobic surfaces are compared. The research shows that if the projected area fraction of water-solid F in the Cassie-Baxter formula is replaced by the local projected area fraction of water-solid F′, the apparent contact angles of water droplets in both Cassie-Baxter state and the mixed state can be calculated. Further experimental results indicate that the contact state of water droplets nearby the outermost three-phase contact line plays a more important role in determining the apparent contact angle. This conclusion is significant to the understanding of the apparent contact angle and wetting property.

  12. Correlation between apparent electrical conductivity and chemical and physical attributes of a Rhodic Hapludox

    Directory of Open Access Journals (Sweden)

    Eduardo Leonel Bottega

    2015-07-01

    Full Text Available Precision agriculture has been used as an important technique for localized management of soil fertility. Therefore, it is essential to characterize the spatial variability of chemical and physical attributes of the soil by sampling can represent such variations. This study aimed to analyze the correlation between the apparent electrical conductivity with the chemical and physical attributes of an Rhodic Hapludox. The work was performed on a property located in the Brazilian Cerrado. In an area of 90 hectare were collected 181 georeferenced soil samples at depths from 0.00 to 0.20 meters. The same sites and removal of samples were made apparent electrical conductivity of the soil. The samples were sent to the laboratory to perform the physical and chemical analysis. Were selected randomly sampling 30 points and calculated the Pearson correlation coefficient between the variable physical, chemical and apparent soil electrical conductivity. There was no significant correlation between the apparent electrical conductivity with the soil physical attributes. There was a significant positive correlation of apparent electrical conductivity of the soil at a depth of 0.20 m with the chemical attributes match, remaining phosphorus and zinc.

  13. Assessing the temporal stability of spatial patterns of soil apparent electrical conductivity using geophysical methods

    Science.gov (United States)

    De Caires, Sunshine A.; Wuddivira, Mark N.; Bekele, Isaac

    2014-10-01

    Cocoa remains in the same field for decades, resulting in plantations dominated with aging trees growing on variable and depleted soils. We determined the spatio-temporal variability of key soil properties in a (5.81 ha) field from the International Cocoa Genebank, Trinidad using geophysical methods. Multi-year (2008-2009) measurements of apparent electrical conductivity at 0-0.75 m (shallow) and 0.75-1.5 m (deep) were conducted. Apparent electrical conductivity at deep and shallow gave the strongest linear correlation with clay-silt content (R = 0.67 and R = 0.78, respectively) and soil solution electrical conductivity (R = 0.76 and R = 0.60, respectively). Spearman rank correlation coefficients ranged between 0.89-0.97 and 0.81- 0.95 for apparent electrical conductivity at deep and shallow, respectively, signifying a strong linear dependence between measurement days. Thus, in the humid tropics, cocoa fields with thick organic litter layer and relatively dense understory cover, experience minimal fluctuations in transient properties of soil water and temperature at the topsoil resulting in similarly stable apparent electrical conductivity at shallow and deep. Therefore, apparent electrical conductivity at shallow, which covers the depth where cocoa feeder roots concentrate, can be used as a fertility indicator and to develop soil zones for efficient application of inputs and management of cocoa fields.

  14. Automatic Detection and Quantification of Acute Cerebral Infarct by Fuzzy Clustering and Histographic Characterization on Diffusion Weighted MR Imaging and Apparent Diffusion Coefficient Map

    Directory of Open Access Journals (Sweden)

    Jang-Zern Tsai

    2014-01-01

    Full Text Available Determination of the volumes of acute cerebral infarct in the magnetic resonance imaging harbors prognostic values. However, semiautomatic method of segmentation is time-consuming and with high interrater variability. Using diffusion weighted imaging and apparent diffusion coefficient map from patients with acute infarction in 10 days, we aimed to develop a fully automatic algorithm to measure infarct volume. It includes an unsupervised classification with fuzzy C-means clustering determination of the histographic distribution, defining self-adjusted intensity thresholds. The proposed method attained high agreement with the semiautomatic method, with similarity index 89.9 ± 6.5%, in detecting cerebral infarct lesions from 22 acute stroke patients. We demonstrated the accuracy of the proposed computer-assisted prompt segmentation method, which appeared promising to replace the laborious, time-consuming, and operator-dependent semiautomatic segmentation.

  15. Apparent Multi-Decadal Trend in Shortwave Cloud Forcing Over the Tropical Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, R C J; Potter, G L; Kanamitsu, M; Hnilo, J J; Woolen, J

    2000-10-03

    The NCEP/NCAR reanalysis (Kalnay et al. 1996) of atmospheric data beginning in 1948 has provided an opportunity to study a consistent half-century record of assimilated weather observations. Through the examination of several fields, we find an apparent long-term decrease in relative humidity, and hence a decrease in inferred cloud amount, in a large region in the central tropical Pacific. As a result, the apparent short-wave cloud radiative forcing in that region decreased by nearly 15 Wm{sup -2} Over the duration of the period. Two major questions arise from these preliminary results. The first question involves the extent to which the apparent trend over the 50-year period is a real phenomenon rather than an artifact, either of the reanalysis methodology or of observing system evolution. The second question is, if the phenomenon is not entirely an artifact, but is at least partially real, what is its cause?

  16. APPARENT DIGESTIBILTY EXPERIMENT WITH NILE TILAPIA (OREOCHROMIS NILOTICUS FED DIETS CONTAINING CITRULLUS LANATUS SEEDMEAL

    Directory of Open Access Journals (Sweden)

    Wasiu Adeyemi JIMOH

    2015-12-01

    Full Text Available Apparent digestibility coefficients of nutrients in Citrullus lanatus based diets were determined for Nile tilapia (Oreochromis niloticus using AIA as marker or indicator. 150 tilapia fingerlings of average weight 6.12±0.05g were acclimatized for a week, weighed and allotted into five dietary treatments; CTR, DT2, DT3, DT4 and DT5 containing 0, 15, 30, 45 and 60% Citrullus lanatus respectively. The diets were isonitrogenous, isocaloric and isolipidic. Each treatment was replicated three times with ten fish per replicate. Fish were fed 5% body weight on two equal proportions per day. The results from the study indicated that there was no significant variation (p>0.05 in the apparent organic matter and gross energy digestibility coefficients of the diets; that there was significant (p0.05 in the apparent digestibility coefficients of nutrients (protein, energy, lipid and carbohydrates between the diets up to 30% replacement levels for tilapia.

  17. Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer

    Science.gov (United States)

    Green, C.T.; Böhlke, J.K.; Bekins, B.A.; Phillips, S.P.

    2010-01-01

    Gradients in contaminant concentrations and isotopic compositions commonly are used to derive reaction parameters for natural attenuation in aquifers. Differences between field-scale (apparent) estimated reaction rates and isotopic fractionations and local-scale (intrinsic) effects are poorly understood for complex natural systems. For a heterogeneous alluvial fan aquifer, numerical models and field observations were used to study the effects of physical heterogeneity on reaction parameter estimates. Field measurements included major ions, age tracers, stable isotopes, and dissolved gases. Parameters were estimated for the O2 reduction rate, denitrification rate, O 2 threshold for denitrification, and stable N isotope fractionation during denitrification. For multiple geostatistical realizations of the aquifer, inverse modeling was used to establish reactive transport simulations that were consistent with field observations and served as a basis for numerical experiments to compare sample-based estimates of "apparent" parameters with "true" (intrinsic) values. For this aquifer, non-Gaussian dispersion reduced the magnitudes of apparent reaction rates and isotope fractionations to a greater extent than Gaussian mixing alone. Apparent and true rate constants and fractionation parameters can differ by an order of magnitude or more, especially for samples subject to slow transport, long travel times, or rapid reactions. The effect of mixing on apparent N isotope fractionation potentially explains differences between previous laboratory and field estimates. Similarly, predicted effects on apparent O2 threshold values for denitrification are consistent with previous reports of higher values in aquifers than in the laboratory. These results show that hydrogeological complexity substantially influences the interpretation and prediction of reactive transport. ?? 2010 by the American Geophysical Union.

  18. Preparation of NaTaO3 by Spray Pyrolysis and Evaluation of Apparent Photocatalytic Activity for Hydrogen Production from Water

    Directory of Open Access Journals (Sweden)

    Hyun Woo Kang

    2008-01-01

    Full Text Available NaTaO3 photocatalyst was prepared by spray pyrolysis process and tested as photocatalyst for water splitting under UV light. Precursor solution was prepared from NaNO3 and Ta(OC2H55 in nitric acid solution and spray-pyrolyzed in air at between 973 and 1273 K. Considerable enhancement of photocatalytic activity was achieved by loading 0.05∼0.2 wt% of NiO on the surface of NaTaO3. The NiO loading was more effective on the NaTaO3 synthesized by spray pyrolysis in comparison with that synthesized by solid-state reaction. The quantum yield (QY of NiO/NaTaO3 photocatalyst was measured by chemical actinometry using potassium ferrioxalate and compared with the apparent photocatalytic activities (APA which would be more useful for the purpose of photocatalytic reactor design than the quantum yield. The apparent photocatalytic activity (APA was defined by the rate of hydrogen production divided by weight of catalyst, volume of reactant mixture, duration of irradiation, and power of UV lamp. The validity of the apparent photocatalytic activity (APA was discussed based on our results and reported activities of NaTaO3 photocatalyst loaded with or without NiO.

  19. Interacting entropy-corrected holographic dark energy with apparent horizon as an infrared cutoff

    OpenAIRE

    Khodam-Mohammadi, A.; Malekjani, M.

    2011-01-01

    In this work we consider the entropy-corrected version of interacting holographic dark energy (HDE), in the non-flat universe enclosed by apparent horizon. Two corrections of entropy so-called logarithmic 'LEC' and power-law 'PLEC' in HDE model with apparent horizon as an IR-cutoff are studied. The ratio of dark matter to dark energy densities $u$, equation of state parameter $w_D$ and deceleration parameter $q$ are obtained. We show that the cosmic coincidence is satisfied for both interacti...

  20. Ablative radioactive iodine therapy for apparently localized thyroid carcinoma. A decision analytic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Wong, J.B.; Kaplan, M.M.; Meyer, K.B.; Pauker, S.G. (Tufts Univ. School of Medicine, Boston, MA (USA))

    1990-09-01

    Adjuvant therapy with ablative radioiodine after surgical resection of apparently localized thyroid carcinoma remains controversial because of the favorable prognosis of thyroid carcinoma and the risk of leukemia from the radioiodine. No controlled trials have been performed to examine this issue. We constructed a decision analytic model to examine whether patients with apparently localized thyroid carcinoma should receive radioiodine. Our analysis suggests that radioiodine modestly improves life expectancy by 2 to 15 months, depending on the patient's age and sex. This model predicts that the benefit of a reduction in the likelihood of recurrence outweighs the risk of leukemia from radioiodine.

  1. Prestanda av användargränssnitt i cross-platform-appar

    OpenAIRE

    Lygnebrandt, Emil; Holm, Jonathan

    2016-01-01

    Syftet med denna studie är att undersöka fördröjningsskillnader inom användargränssnitt mellan native­utvecklade appar (utveckling till varje plattform) och appar av typen generated apps. Eftersom arbetet syftar till att bidra med information om prestanda ansågs en experimentell metod vara det bästa valet. Mätning av laddningstider gjordes med hjälp av en videokamera som filmade utförandet av experimenten vilket gjorde metoden simpel och liknar det som en användare kommer att uppleva. Avgräns...

  2. Two-dimensional modeling of apparent resistivity pseudosections in the Cerro Prieto region

    Energy Technology Data Exchange (ETDEWEB)

    Vega, R.; Martinez, M.

    1981-01-01

    Using a finite-difference program (Dey, 1976) for two-dimensional modeling of apparent resistivity pseudosections obtained by different measuring arrays, four apparent resistivity pseudosections obtained at Cerro Prieto with a Schlumberger array by CFE personnel were modeled (Razo, 1978). Using geologic (Puente and de la Pena, 1978) and lithologic (Diaz, et al., 1981) data from the geothermal region, models were obtained which show clearly that, for the actual resistivity present in the zone, the information contained in the measured pseudosections is primarily due to the near-surface structure and does not show either the presence of the geothermal reservoir or the granitic basement which underlies it.

  3. Apparently persistent weakness after recurrent hypokalemic paralysis: a tale of two disorders.

    Science.gov (United States)

    Ramachandiran, Nandhagopal

    2008-09-01

    A 19-year-old woman presented with recurrent hypokalemic paralysis, followed by apparently persistent symptoms due to coexisting osteomalacia. Distal renal tubular acidosis type 1 (dRTA1) linked the metabolic abnormalities and occurred as an extraglandular feature of Sjögren syndrome (SS). This case highlights the fact that in the setting of recurrent hypokalemia, apparently progressive weakness should be distinguished from primary hypokalemic paralysis and evaluated for dRTA1, as the metabolic alterations are potentially treatable. Further dRTA1 may precede the occurrence of sicca syndrome in SS. PMID:18708979

  4. Study of the measurement about the apparent heat transfer coefficient of solid uranium hexafluoride

    International Nuclear Information System (INIS)

    In order to provide the conditions for designing the congealed accept container of uranium hexafluoride, a set of experiment system of measuring apparent heat transfer coefficient in which the small-sized congealed accept container was considered as main equipment was set up. Then the experiments of loading and unloading uranium hexafluoride were carried out. The process of loading and unloading uranium hexafluoride in small-sized congealed accept container were simulated by the barrel model of steady heat transfer in this paper, and the apparent heat transfer coefficient of solid uranium hexafluoride was obtained. (authors)

  5. The generalized second law of gravitational thermodynamics on the apparent and event horizons in FRW cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Karami, K; Ghaffari, S; Soltanzadeh, M M, E-mail: KKarami@uok.ac.i [Department of Physics, University of Kurdistan, Pasdaran St, Sanandaj (Iran, Islamic Republic of)

    2010-10-21

    We investigate the validity of the generalized second law (GSL) of gravitational thermodynamics on the apparent and event horizons in a non-flat Friedmann-Robertson-Walker (FRW) universe containing dark energy interacting with dark matter. We show that for the dynamical apparent horizon, the GSL is always satisfied throughout the history of the universe for any spatial curvature and it is independent of the equation of state parameter of the interacting dark energy model. On the other hand, for the cosmological event horizon, the validity of the GSL depends on the equation of state parameter of the model.

  6. The generalized second law of gravitational thermodynamics on the apparent and event horizons in FRW cosmology

    International Nuclear Information System (INIS)

    We investigate the validity of the generalized second law (GSL) of gravitational thermodynamics on the apparent and event horizons in a non-flat Friedmann-Robertson-Walker (FRW) universe containing dark energy interacting with dark matter. We show that for the dynamical apparent horizon, the GSL is always satisfied throughout the history of the universe for any spatial curvature and it is independent of the equation of state parameter of the interacting dark energy model. On the other hand, for the cosmological event horizon, the validity of the GSL depends on the equation of state parameter of the model.

  7. Influence of fluid-attenuated inversion-recovery on stroke apparent diffusion coefficient measurements and its clinical application

    International Nuclear Information System (INIS)

    Background and purpose: The application of a fluid-attenuated inversion-recovery pulse with a conventional diffusion-weighted MRI sequence (FLAIR DWI) decreases the partial volume effects from cerebrospinal fluid on apparent diffusion coefficient (ADC) measurements. For this reason, FLAIR DWI may be more useful in the evaluation of ischemic stroke, but few studies have looked at the effect of FLAIR on ADC measurements in this setting. This study quantitatively compares FLAIR DWI and conventional DWI in ischemic stroke of varying ages to assess the potential advantages of this technique. Methods: We respectively analyzed 139 DWI studies in patients with ischemic stroke with and without FLAIR at varying time points ranging from hyperacute to chronic. ADC values were measured in each lesion, as well as in the contralateral normal side. Comparisons were made between the ADC values obtained from the DWI sequences with and without FLAIR for both the lesion and the normal contralateral side. Results: The ADC measurements within the ischemic lesion were very similar on FLAIR DWI and conventional DWI for lesions less than 14 days old (p > 0.05), but were significantly decreased on FLAIR DWI for lesions between 15 and 30 days old and in lesions >31 days old (chronic stage) (p < 0.01). The contralateral ADC values were all significantly decreased on the FLAIR DWI sequence compared with conventional DWI (p < 0.01). Conclusions: The application of an inversion pulse does not significantly affect the ADC values for early stage ischemic stroke (less than 14 days from symptom onset), but results in a more accurate relative ADC measurement by reducing the cerebrospinal fluid partial volume effects of the normal contralateral side. In addition, combined with the conventional DWI, FLAIR DWI may be helpful in determining the age of ischemic lesions.

  8. Relationships between brain water content and diffusion tensor imaging parameters (apparent diffusion coefficient and fractional anisotropy) in multiple sclerosis

    International Nuclear Information System (INIS)

    Fifteen multiple sclerosis patients were examined by diffusion tensor imaging (DTI) to determine fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in a superventricular volume of interest of 8 x 8 x 2 cm3 containing gray matter (GM) and white matter (WM) tissue. Point resolved spectroscopy 2D-chemical shift imaging of the same volume was performed without water suppression. The water contents and DTI parameters in 64 voxels of 2 cm3 were compared. The water content was increased in patients compared with controls (GM: 244±21 vs. 194±10 a.u.; WM: 245±32 vs. 190±11 a.u.), FA decreased (GM: 0.226±0.038 vs. 0.270±0.020; WM: 0.337±0.044 vs. 0.402±0.011) and ADC increased [GM: 1134±203 vs. 899±28 (x 10-6 mm2/s); WM: 901±138 vs. 751±17 (x 10-6 mm2/s)]. Correlations of water content with FA and ADC in WM were strong (r=-0.68, P<0.02; r=0.75; P<0.01, respectively); those in GM were weaker (r=-0.50, P<0.05; r=0.45, P<0.1, respectively). Likewise, FA and ADC were more strongly correlated in WM (r=-0.88; P<0.00001) than in GM (r=-0.69, P<0.01). The demonstrated relationship between DTI parameters and water content in multiple sclerosis patients suggests a potential for therapy monitoring in normal-appearing brain tissue. (orig.)

  9. Effects of concentration and temperature on molar volumes of L-serine, L-isoleucine, and L-glutamine in aqueous NaCl and NaNO3 solutions

    Science.gov (United States)

    Riyazuddeen; Kumar, Dheeraj; Afrin, Sadaf

    2014-01-01

    Densities of L-serine, L-isoleucine, L-glutamine in 1.5 mol kg-1 aqueous NaCl, and NaNO3 solutions have been measured for several molal concentrations of amino acids at temperatures from 298.15 to 323.15 K. The partial molar volumes (ϕ{/v 0}) of L-serine, L-isoleucine, and L-glutamine in 1.5 mol kg-1 aqueous NaCl/NaNO3 solutions have been computed using density data. The transfer partial molar volumes (Δtrϕ{/v 0}) of L-serine, L-isoleucine, and L-glutamine from water to 1.5 mol kg-1 aqueous NaCl/1.5 mol kg-1 aqueous NaNO3 solutions have been determined at 298.15 K. The trends of variation of ϕ{/v 0} and Δtrϕ{/v 0} with change in temperature have been discussed in terms of ion-ion, ion-hydrophilic, and ion-hydrophobic interactions operative in solutions.

  10. Apparent viscosity and particle pressure of a concentrated suspension of non-Brownian hard spheres near the jamming transition.

    Science.gov (United States)

    Mills, P; Snabre, P

    2009-11-01

    We consider the steady shear flow of a homogeneous and dense assembly of hard spheres suspended in a Newtonian viscous fluid. In a first part, a mean-field approach based on geometric arguments is used to determine the viscous dissipation in a dense isotropic suspension of smooth hard spheres and the hydrodynamic contribution to the suspension viscosity. In a second part, we consider the coexistence of transient solid clusters coupled to regions with free flowing particles near the jamming transition. The fraction of particles in transient clusters is derived through the Landau-Ginzburg concepts for first-order phase transition with an order parameter corresponding to the proportion of "solid" contacts. A state equation for the fraction of particle-accessible volume is introduced to derive the average normal stresses and a constitutive law that relates the total shear stress to the shear rate. The analytical expression of the average normal stresses well accounts for numerical or experimental evaluation of the particle pressure and non-equilibrium osmotic pressure in a dense sheared suspension. Both the friction level between particles and the suspension dilatancy are shown to determine the singularity of the apparent shear viscosity and the flow stability near the jamming transition. The model further predicts a Newtonian behavior for a concentrated suspension of neutrally buoyant particles and no shear thinning behavior in relation with the shear liquefaction of transient solid clusters. PMID:19856003

  11. A COMPARATIVE EVALUATION OF PULMONARY PARAMETERS IN DIABETES MELLITUS PATIENTS AND NON DIABETES MELLITUS APPARENTLY HEALTHY VOLUNTEER AS CONTROL

    Directory of Open Access Journals (Sweden)

    Qazi Rais Ahmed

    2012-10-01

    Full Text Available The best early evidence of a description of the symptoms of diabetes in the world's literature is recorded in the Ebers Papyrus that Diabetes Mellitus is characterized by chronic hyperglycemia with disturbances of carbohydrate, fat, and protein metabolism result in from defects in insulin secretion, insulin action, or both which affect the respiratory system also. So we decided to study the effects of diabetes mellitus on pulmonary parameters. In this study a group of 50 apparently healthy control subject of both gender and 50 Diabetic patients of both gender were randomly selected with age ranging from 19-68 years. The Diabetic patients were matched with control group in terms of age, height, weight and BSA and BMI. Spirometry was performed on an electronic spirometer (spiro exel according to American Thoracic Society and results were compared by a student t-test (2-tailed. Diabetic patients showed a significant decrement in the Forced Vital Capacity (FVC % and Peak Expiratory Flow Rate (PEFR % relative to their matched controls. However, there were no significant difference in the Forced Expiratory Volume in one Second (FEV1% and Forced Expiratory Ratio (FEV1 / FVC % between the groups We conclude that pulmonary parameters in diabetic patients there is decrement in FVC% and PEFR%, as compared to controls. which indicate restrictive pattern of lung function impairment.

  12. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    - serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...... of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume......, controlled cell death and cellular migration. Volume regulatory mechanisms has long been in focus for regulating cellular proliferation and my thesis work have been focusing on the role of Cl- channels in proliferation with specific emphasis on ICl, swell. Pharmacological blockage of the ubiquitously...

  13. Volume Regulation in Epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Hoffmann, Else Kay

    2016-01-01

    We review studies on regulatory volume decrease (RVD) and regulatory volume increase (RVI) of major ion and water transporting vertebrate epithelia. The rate of RVD and RVI is faster in cells of high osmotic permeability like amphibian gallbladder and mammalian proximal tubule as compared to...... amphibian skin and mammalian cortical collecting tubule of low and intermediate osmotic permeability. Crosstalk between entrance and exit mechanisms interferes with volume regulation both at aniso-osmotic and iso-osmotic volume perturbations. It has been proposed that cell volume regulation is an intrinsic...... function of iso-osmotic fluid transport that depends on Na+ recirculation. The causative relationship is discussed for a fluid-absorbing and a fluid-secreting epithelium of which the Na+ recirculation mechanisms have been identified. A large number of transporters and ion channels involved in cell volume...

  14. Profile Method for Measuring Apparent Optical Parameters (AOP)in Class-Ⅱ Waters

    Institute of Scientific and Technical Information of China (English)

    李铜基; 陈清莲

    2004-01-01

    The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly,then modifies the applied algorithm in the light of the properties of the class- Ⅱ waters and lastly, analyses the effect of application.

  15. 45 CFR 73.735-904 - Resolution of apparent or actual conflicts of interest.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Resolution of apparent or actual conflicts of interest. 73.735-904 Section 73.735-904 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL... activity giving rise to the problem: (1) Bears a direct or indirect relationship to...

  16. Analytical criteria for predicting apparent digestibility of soybean protein in preruminant calves.

    Science.gov (United States)

    Lalles, J P; Tukur, H M; Toullec, R; Miller, B G

    1996-03-01

    A series of experiments on the use of soybean as a protein source in milk replacers for veal calves was undertaken to determine the relationships between the physicochemical and antinutritional properties and apparent digestibilities of nine soybean products. Soybean provided between 58 and 71% of dietary CP, and skim milk or whey powder provided the remainder. Soybean products were analyzed for CP, native protein, aggregated protein, carbohydrate-linked protein, peptides, antitryptic activity, and immunoreactivity of lectin, glycinin, alpha-conglycinin, and beta-conglycinin. The apparent digestibility of N calculated for soybean protein varied between 59 and 84%. Simple linear correlations were significant between apparent digestibility of soybean N and concentrations of native protein, antitryptic activity, glycinin, alpha-conglycinin, and beta-conglycinin. However, only variation in antitryptic activity, alpha-conglycinin, and beta-conglycinin contributed significantly to an explanation for the variation in apparent digestibility of soybean N in a multiple linear equation. Under our experimental conditions, beta-conglycinin was the best predictor of digestibility of soybean N. Antitryptic activity became the best predictor when soybean products had no detectable beta-conglycinin. PMID:8708110

  17. Dermatophytes from Apparently Healthy Toe-webs of Service Personnel Stationed in Northeastren Region of India

    OpenAIRE

    R. R. Mattada; Das, T. K.; K. Zachariah

    1982-01-01

    Apparently healthy toe-webs of 230 individuals belonging to various Army units stationed India were studied for dermatophytes. 35 were found positive. This revealed the presence of 28 Trichophyton mentagrophytes, 4 Epidermophyton floccosum, 2 Microsporum gypseum and 1 T. rubrum.

  18. The effect of interaural-time-difference fluctuations on apparent source width

    DEFF Research Database (Denmark)

    Käsbach, Johannes; May, Tobias; Oskarsdottir, Gudrun;

    2014-01-01

    For the perception of spaciousness, the temporal fluctuations of the interaural time differences (ITDs) and interaural level differences (ILDs) provide important binaural cues. One major characteristic of spatial perception is apparent source width (ASW), which describes the perceived width of a ...

  19. Gamow's bicycle: The Appearance of Bodies at Relativistic Speeds and Apparent Superluminal Velocities

    CERN Document Server

    Nowojewski, A

    2005-01-01

    A human creates an image basing on the information delivered by photons that arrived at his retina simultaneously. Due to finite and constant velocity of light these photons left the moving body at different times, since not all points of the body are equidistant. In other words its image represents the body as it was in several different times i.e. it is distorted and does not correspond to its real appearance. The useful experimental arrangement is set and then used to derive the general expression that transforms two-dimensional stationary shapes to their apparent forms, which could be photographed once they are set in motion. It is then used to simulate the so-called Gamow's bicycle combined out of circles and straight lines. The simulation outlines two important aspects of bike's motion: apparent distance of two points and apparent velocity which are then discussed thoroughly. It is found that the approaching body is elongated and its apparent speed is greater than its real one (under certain conditions ...

  20. Primary School Students' Ideas Concerning the Apparent Movement of the Moon

    Science.gov (United States)

    Starakis, John; Halkia, Krystallia

    2010-01-01

    In the present study, primary school students' ideas concerning the apparent movement of the Moon are investigated. The research was carried out in five primary schools of Athens (Greece) with a sample of forty (40), fifth and sixth grade students. Semistructured interviews were used to gather scientific data and students had the opportunity to…

  1. [Effect of drought stress on apparent resource utilization efficiency of Quercus mongolica].

    Science.gov (United States)

    Wang, Miao; Dai, Limin; Ji, Lanzhu

    2002-03-01

    To study the effect of drought stress on the physiological characteristics and resource utilization efficiency of Quercus mongolica, a dominant species in the Korean pine broad-leaved forest in Changbai Mountain, a comparative experiment was carried out under three soil moisture gradients as 85%-100% (high water, CK), 65%-85% (Medium water, MW), and 45%-65% (low water, LW) of field water-bolding capacity. The results showed that net photosynthetic rate, stomatal conduction, transpiration rate, water utilization efficiency, apparent CO2 utilization efficiency and apparent light utilization efficiency of the seedlings of Quercus mongolica were all significantly influenced by simulated drought stress. Stomatal conduction, water utilization efficiency and net photosynthetic rate of large tress of Quercus mongolica were affected by the soil drought stress, while transpiration rate, apparent CO2 utilization efficiency, and apparent light utilization efficiency were not influenced. Moderate soil water condition could greatly increase gas exchange and water utilization efficiency. These results indicated that the responses of gas exchange and resource utilization efficiency to various water stresses were different. Quercus mongolica was a species with variable resistance to drought stress, and the resistance would be improved by drought stress, especially moderate water stress. PMID:12132152

  2. The apparent influence of climatic change on recent changes of range by European insects (Lepidoptera, Orthoptera)

    NARCIS (Netherlands)

    Burton, J.F.

    2003-01-01

    The apparent influence of climatic change on recent changes of range by European insects (Lepidoptera, Orthoptera) For several years I have been collecting data concerning changes in the ranges of European insects, especially Lepidoptera and Orthoptera. The vast majority of those species which have

  3. In vivo measurement of apparent diffusion coefficients of hyperpolarized 13C‐labeled metabolites

    DEFF Research Database (Denmark)

    Søgaard, Lise Vejby; Schilling, Franz; Janich, Martin A.; Menzel, Marion I.; Ardenkjær-Larsen, Jan Henrik

    2014-01-01

    The combination of hyperpolarized MRS with diffusion weighting (dw) allows for determination of the apparent diffusion coefficient (ADC), which is indicative of the intra‐ or extracellular localization of the metabolite. Here, a slice‐selective pulsed‐gradient spin echo sequence was implemented t...

  4. Unified first law and the thermodynamics of the apparent horizon in the FRW universe

    International Nuclear Information System (INIS)

    In this paper we revisit the relation between the Friedmann equations and the first law of thermodynamics. We find that the unified first law first proposed by Hayward to treat the outertrapping horizon of a dynamical black hole can be used to the apparent horizon (a kind of inner trapping horizon in the context of the FRW cosmology) of the FRW universe. We discuss three kinds of gravity theorties: Einstein theory, Lovelock thoery, and scalar-tensor theory. In Einstein theory, the first law of thermodynamics is always satisfied on the apparent horizon. In Lovelock theory, treating the higher derivative terms as an effective energy-momentum tensor, we find that this method can give the same entropy formula for the apparent horizon as that of black hole horizon. This implies that the Clausius relation holds for the Lovelock theory. In scalar-tensor gravity, we find, by using the same procedure, the Clausius relation no longer holds. This indicates that the apparent horizon of the FRW universe in the scalar-tensor gravity corresponds to a system of nonequilibrium thermodynamics. We show this point by using the method developed recently by Eling et al. for dealing with the f(R) gravity

  5. Effect of Soil Water on Apparent Soil Electrical Conductivity and Texture Relationships in a Dryland Field.

    Science.gov (United States)

    Precision farming (PF) research has shown that when high salinity levels are not present, apparent soil electrical conductivity (ECa) is usually strongly correlated with soil texture. Mapping ECa has been promoted as a means for identifying management zones that are needed for variable application ...

  6. Apparent-contact-angle model at partial wetting and evaporation: Impact of surface forces

    Science.gov (United States)

    Janeček, V.; Nikolayev, V. S.

    2013-01-01

    This theoretical and numerical study deals with evaporation of a fluid wedge in contact with its pure vapor. The model describes a regime where the continuous wetting film is absent and the actual line of the triple gas-liquid-solid contact appears. A constant temperature higher than the saturation temperature is imposed at the solid substrate. The fluid flow is solved in the lubrication approximation. The introduction of the surface forces in the case of the partial wetting is discussed. The apparent contact angle (the gas-liquid interface slope far from the contact line) is studied numerically as a function of the substrate superheating, contact line velocity, and parameters related to the solid-fluid interaction (Young and microscopic contact angles, Hamaker constant, etc.). The dependence of the apparent contact angle on the substrate temperature is in agreement with existing approaches. For water, the apparent contact angle may be 20∘ larger than the Young contact angle for 1 K superheating. The effect of the surface forces on the apparent contact angle is found to be weak.

  7. Measuring the unevenness of yarn apparent diameter from yarn sequence images

    Science.gov (United States)

    Li, Zhongjian; Pan, Ruru; Zhang, Jie; Li, Bianbian; Gao, Weidong; Bao, Wei

    2016-01-01

    This article presents a novel method for measuring the unevenness of yarn apparent diameter based on yarn sequence images captured from a moving yarn. A dynamic threshold module was designed to gain the global threshold for segmenting yarns in the sequence images. In the module, a K-means clustering algorithm was employed to classify the pixels of each frame in the sequence into two clusters—yarn and background. The cluster center of the current frame was used as the initial value of the cluster center for the next frame in the sequence to expedite the segmentation process. From the segmented yarn image, the yarn core was further extracted utilizing the characteristics of yarn hairiness, and two judgment templates were adopted to remove burrs, isolated points and unrelated small areas in the images. The yarn apparent diameter was measured on the yarn core at a given interval. The same kind of yarns were tested by using this method and Uster Evenness Tester 5. The experimental results show that the proposed method can accurately detect the unevenness of yarn apparent diameter and provide new useful information about yarn unevenness, such as the short-term, the long-term, and the periodic variations of yarn apparent diameters.

  8. The reductive decomposition of calcium sulphate I. Kinetics of the apparent solid-solid reaction

    NARCIS (Netherlands)

    Kamphuis, B.; Potma, A.W.; Prins, W.; Swaaij, van W.P.M.

    1992-01-01

    The reductive decomposition of calcium sulphate by hydrogen is used for the regeneration of calcium-based atmospheric fluidized bed combustion (AFBC) SO2 sorbents. The apparent solid¿solid reaction between CaS and CaSO4, one of the steps involved in the reaction mechanism of the reductive decomposit

  9. Irreversible thermodynamics of dark energy on the entropy-corrected apparent horizon

    Energy Technology Data Exchange (ETDEWEB)

    Karami, K; Sahraei, N [Department of Physics, University of Kurdistan, Pasdaran Street, Sanandaj (Iran, Islamic Republic of); Jamil, M, E-mail: KKarami@uok.ac.i, E-mail: mjamil@camp.nust.edu.p [Center for Advanced Mathematics and Physics (CAMP), National University of Sciences and Technology (NUST), Islamabad (Pakistan)

    2010-10-15

    We study the irreversible (non-equilibrium) thermodynamics of the Friedmann-Robertson-Walker (FRW) universe containing only dark energy. Using the modified entropy-area relation that is motivated by loop quantum gravity, we calculate the entropy-corrected form of the apparent horizon of the FRW universe.

  10. Apparent Temperature and Cause-Specific Mortality in Copenhagen, Denmark: A Case-Crossover Analysis

    DEFF Research Database (Denmark)

    Wichmann, Janine; Jovanovic Andersen, Zorana; Ketzel, Matthias; Ellermann, Thomas; Loft, Steffen

    2011-01-01

    Temperature, a key climate change indicator, is expected to increase substantially in the Northern Hemisphere, with potentially grave implications for human health. This study is the first to investigate the association between the daily 3-hour maximum apparent temperature (Tapp(max)), and...

  11. Constraints on dark energy from H II starburst galaxy apparent magnitude versus redshift data

    International Nuclear Information System (INIS)

    In this Letter we use H II starburst galaxy apparent magnitude versus redshift data from Siegel et al. (2005) to constrain dark energy cosmological model parameters. These constraints are generally consistent with those derived using other data sets, but are not as restrictive as the tightest currently available constraints.

  12. Definition of management zones in coffee production fields based on apparent soil electrical conductivity

    Directory of Open Access Journals (Sweden)

    Domingos Sárvio Magalhães Valente

    2012-06-01

    Full Text Available Fertilizer application at variable rates requires dense sampling to determine the resulting field spatial variability. Defining management zones is a technique that facilitates the variable-rate application of agricultural inputs. The apparent electrical conductivity of the soil is an important factor in explaining the variability of soil physical-chemical properties. Thus, the objective of this study was to define management zones for coffee (Coffea Arabica L. production fields based on spatial variability of the apparent electrical conductivity of the soil. The resistivity method was used to measure the apparent soil electrical conductivity. Soil samples were collected to measure the chemical and physical soil properties. The maps of spatial variability were generated using ordinary kriging method. The fuzzy k-means algorithm was used to delimit the management zones. To analyze the agreement between the management zones and the soil properties, the kappa coefficients were calculated. The best results were obtained for the management zones defined using the apparent electrical conductivity of the soil and the digital elevation model. In this case, the kappa coefficient was 0.45 for potassium, which is an element that is associated with quality coffee. The other variable that had a high kappa coefficient was remaining phosphorous; the coefficient obtained was 0.49. The remaining phosphorus is an important parameter for determining which fertilizers and soil types to study.

  13. Apparent violation of thermodynamics second law under Van der Waals gas expansion in vacuum

    OpenAIRE

    Koksharov, Yury A.

    2006-01-01

    Examining textbooks of thermodynamics we have not able to find a proof of increasing of entropy under free adiabatic expansion in vacuum based on the state equation of the Van der Waals gas. This communication remedies the situation. During proving we faced with an amusing example of apparent violation of thermodynamics second law.

  14. Structure of Gamma-Ray Burst jets: intrinsic versus apparent properties

    CERN Document Server

    Salafia, O S; Pescalli, A; Ghirlanda, G; Nappo, F

    2015-01-01

    With this paper we introduce the concept of apparent structure of a GRB jet, as opposed to its intrinsic structure. The latter is customarily defined specifying the functions epsilon(theta) (the energy emitted per jet unit solid angle) and Gamma(theta) (the Lorentz factor of the emitting material); the apparent structure is instead defined by us as the isotropic equivalent energy E_iso(theta_v) as a function of the viewing angle theta_v. We show how to predict the apparent structure of a jet given its intrinsic structure. We find that a Gaussian intrinsic structure yields a power law apparent structure: this opens a new viewpoint on the Gaussian (which can be understood as a proxy for a realistic narrow, well collimated jet structure) as a possible candidate for a quasi-universal GRB jet structure. We show that such a model (a) is consistent with recent constraints on the observed luminosity function of GRBs; (b) implies fewer orphan afterglows with respect to the standard uniform model; (c) can break out the...

  15. Bacteriophage T4 genes sp and 40 apparently are the same.

    OpenAIRE

    Obringer, J; McCreary, P.; Bernstein, H

    1988-01-01

    The bacteriophage T4 spackle gene, which maintains host membrane integrity, mapped at the same position as gene 40 (head morphogenesis). The cloned spackle gene complemented and cross-reactivated a gene 40 mutant. Like the spackle mutant, gene 40 mutants were defective in genetic exclusion. Apparently, genes spackle and 40 are the same gene.

  16. Linseed dietary fibers reduce apparent digestibility of energy and fat and weight gain in growing rats

    DEFF Research Database (Denmark)

    Kristensen, M.; Knudsen, K. E. B.; Jørgensen, H.;

    2013-01-01

    Dietary fibers (DF) may affect energy balance, an effect often ascribed to the viscous nature of some water soluble DF, which affect luminal viscosity and thus multiple physiological processes. We have tested the hypothesis that viscous linseed DF reduce apparent nutrient digestibility, and limit...

  17. Dietary factors associated with plasma high molecular weight and total adiponectin levels in apparently healthy women

    NARCIS (Netherlands)

    Yannakoulia, Mary; Yiannakouris, Nikos; Melistas, Labros; Fappa, Evaggelia; Vidra, Nikoletta; Kontogianni, Meropi D; Mantzoros, Christos S

    2008-01-01

    OBJECTIVE: Our aim was to investigate associations between dietary factors and high molecular weight (HMW) as well as total adiponectin in a sample of apparently healthy adult Mediterranean women. DESIGN AND METHODS: Two hundred and twenty women were enrolled in this study. Anthropometric and body c

  18. The apparent solubility of aluminum (III) in Hanford high-level waste.

    Science.gov (United States)

    Reynolds, Jacob G

    2012-01-01

    The solubility of aluminum in Hanford nuclear waste impacts on the processability of the waste by a number of proposed treatment options. For many years, Hanford staff has anecdotally noted that aluminum appears to be considerably more soluble in Hanford waste than the simpler electrolyte solutions used as analogues. There has been minimal scientific study to confirm these anecdotal observations, however. The present study determines the apparent solubility product for gibbsite in 50 tank samples. The ratio of hydroxide to aluminum in the liquid phase for the samples is calculated and plotted as a function of total sodium molarity. Total sodium molarity is used as a surrogate for ionic strength, because the relative ratios of mono-, di- and trivalent anions are not available for all of the samples. These results were compared to the simple NaOH-NaAl(OH)(4)-H(2)O system, and the NaOH-NaAl(OH)(4)-NaCl-H(2)O system data retrieved from the literature. The results show that gibbsite is apparently more soluble in the samples than in the simple systems whenever the sodium molarity is greater than 2M. This apparent enhanced solubility cannot be explained solely by differences in ionic strength. The change in solubility with ionic strength in simple systems is small compared to the difference between aluminum solubility in Hanford waste and the simple systems. The reason for the apparent enhanced solubility is unknown, but could include kinetic or thermodynamic factors that are not present in the simple electrolyte systems. Any kinetic explanation would have to explain why the samples are always supersaturated whenever the sodium molarity is above 2M. Real waste characterization data should not be used to validate thermodynamic solubility models until it can be confirmed that the apparent enhanced gibbsite solubility is a thermodynamic effect and not a kinetic effect. PMID:22934992

  19. Evaluating apparent competition in limiting the recovery of an endangered ungulate.

    Science.gov (United States)

    Johnson, Heather E; Hebblewhite, Mark; Stephenson, Thomas R; German, David W; Pierce, Becky M; Bleich, Vernon C

    2013-01-01

    Predation can disproportionately affect endangered prey populations when generalist predators are numerically linked to more abundant primary prey. Apparent competition, the term for this phenomenon, has been increasingly implicated in the declines of endangered prey populations. We examined the potential for apparent competition to limit the recovery of Sierra Nevada bighorn sheep (Ovis canadensis sierrae), an endangered subspecies under the US Endangered Species Act. Using a combination of location, demographic, and habitat data, we assessed whether cougar (Puma concolor) predation on endangered bighorn sheep was a consequence of their winter range overlap with abundant mule deer (Odocoileus hemionus). Consistent with the apparent competition hypothesis, bighorn sheep populations with higher spatial overlap with deer exhibited higher rates of cougar predation which had additive effects on adult survival. Bighorn sheep killed by cougars were primarily located within deer winter ranges, even though those areas constituted only a portion of the bighorn sheep winter ranges. We suspect that variation in sympatry between bighorn sheep and deer populations was largely driven by differences in habitat selection among bighorn sheep herds. Indeed, bighorn sheep herds that experienced the highest rates of predation and the greatest spatial overlap with deer also exhibited the strongest selection for low elevation habitat. Although predator-mediated apparent competition may limit some populations of bighorn sheep, it is not the primary factor limiting all populations, suggesting that the dynamics of different herds are highly idiosyncratic. Management plans for endangered species should consider the spatial distributions of key competitors and predators to reduce the potential for apparent competition to hijack conservation success. PMID:22791131

  20. The Apparent Solubility Of Aluminum(III) In Hanford High-Level Waste Tanks

    International Nuclear Information System (INIS)

    The solubility of aluminum in Hanford nuclear waste impacts on the process ability of the waste by a number of proposed treatment options. For many years, Hanford staff has anecdotally noted that aluminum appears to be considerably more soluble in Hanford waste than the simpler electrolyte solutions used as analogues. There has been minimal scientific study to confirm these anecdotal observations, however. The present study determines the apparent solubility product for gibbsite in 50 tank samples. The ratio of hydroxide to aluminum in the liquid phase for the samples is calculated and plotted as a function of total sodium molarity. Total sodium molarity is used as a surrogate for ionic strength, because the relative ratios of mono, di and trivalent anions are not available for all of the samples. These results were compared to the simple NaOH-NaAl(OH4)H2O system, and the NaOH-NaAl(OH4)NaCl-H2O system data retrieved from the literature. The results show that gibbsite is apparently more soluble in the samples than in the simple systems whenever the sodium molarity is greater than two. This apparent enhanced solubility cannot be explained solely by differences in ionic strength. The change in solubility with ionic strength in simple systems is small compared to the difference between aluminum solubility in Hanford waste and the simple systems. The reason for the apparent enhanced solubility is unknown, but could include. kinetic or thermodynamic factors that are not present in the simple electrolyte systems. Any kinetic explanation would have to explain why the samples are always supersaturated whenever the sodium molarity is above two. Real waste characterization data should not be used to validate thermodynamic solubility models until it can be confirmed that the apparent enhanced gibbsite solubility is a thermodynamic effect and not a kinetic effect.

  1. Climate control of decadal-scale increases in apparent ages of eogenetic karst spring water

    Science.gov (United States)

    Martin, Jonathan B.; Kurz, Marie J.; Khadka, Mitra B.

    2016-09-01

    Water quantity and quality in karst aquifers may depend on decadal-scale variations in recharge or withdrawal, which we hypothesize could be assessed through time-series measurements of apparent ages of spring water. We tested this hypothesis with analyses of various age tracers (3H/3He, SF6, CFC-11, CFC-12, CFC-113) and selected solute concentrations [dissolved oxygen (DO), NO3, Mg, and SO4] from 6 springs in a single spring complex (Ichetucknee springs) in northern Florida over a 16-yr period. These springs fall into two groups that reflect shallow short (Group 1) and deep long (Group 2) flow paths. Some tracer concentrations are altered, with CFC-12 and CFC-113 concentrations yielding the most robust apparent ages. These tracers show a 10-20-yr monotonic increase in apparent age from 1997 to 2013, including the flood recession that followed Tropical Storm Debby in mid-2012. This increase in age indicates most water discharged during the study period recharged the aquifer within a few years of 1973 for Group 2 springs and 1980 for Group 1 springs. Inverse correlations between apparent age and DO and NO3 concentrations reflect reduced redox state in older water. Positive correlations between apparent age and Mg and SO4 concentrations reflect increased water-rock reactions. Concentrated recharge in the decade around 1975 resulted from nearly 2 m of rain in excess of the monthly average that fell between 1960 and 2014, followed by a nearly 4 m deficit to 2014. This excess rain coincided with two major El Niño events during the maximum cool phase in the Atlantic Multidecadal Oscillation. Although regional water withdrawal increased nearly 5-fold between 1980 and 2005, withdrawals represent only 2-5% of Ichetucknee River flow and are less important than decadal-long variations in precipitation. These results suggest that groundwater management should consider climate cycles as predictive tools for future water resources.

  2. The apparent solubility of aluminum (III) in Hanford high-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Jacob G.

    2012-12-01

    The solubility of aluminum in Hanford nuclear waste impacts on the process ability of the waste by a number of proposed treatment options. For many years, Hanford staff has anecdotally noted that aluminum appears to be considerably more soluble in Hanford waste than the simpler electrolyte solutions used as analogues. There has been minimal scientific study to confirm these anecdotal observations, however. The present study determines the apparent solubility product for gibbsite in 50 tank samples. The ratio of hydroxide to aluminum in the liquid phase for the samples is calculated and plotted as a function of total sodium molarity. Total sodium molarity is used as a surrogate for ionic strength, because the relative ratios of mono, di and trivalent anions are not available for all of the samples. These results were compared to the simple NaOH-NaAl(OH{sub 4})H{sub 2}O system, and the NaOH-NaAl(OH{sub 4})NaCl-H{sub 2}O system data retrieved from the literature. The results show that gibbsite is apparently more soluble in the samples than in the simple systems whenever the sodium molarity is greater than two. This apparent enhanced solubility cannot be explained solely by differences in ionic strength. The change in solubility with ionic strength in simple systems is small compared to the difference between aluminum solubility in Hanford waste and the simple systems. The reason for the apparent enhanced solubility is unknown, but could include. kinetic or thermodynamic factors that are not present in the simple electrolyte systems. Any kinetic explanation would have to explain why the samples are always supersaturated whenever the sodium molarity is above two. Real waste characterization data should not be used to validate thermodynamic solubility models until it can be confirmed that the apparent enhanced gibbsite solubility is a thermodynamic effect and not a kinetic effect.

  3. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.;

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125) and...

  4. Postoperative volume balance

    DEFF Research Database (Denmark)

    Frost, H; Mortensen, C.R.; Secher, N H;

    2016-01-01

    In healthy humans, stroke volume (SV) and cardiac output (CO) do not increase with expansion of the central blood volume by head-down tilt or administration of fluid. Here, we exposed 85 patients to Trendelenburg's position about one hour after surgery while cardiovascular variables were determined...

  5. Influence of the high-affinity growth hormone (GH)-binding protein on plasma profiles of free and bound GH and on the apparent half-life of GH. Modeling analysis and clinical applications.

    OpenAIRE

    Veldhuis, J D; Johnson, M.L.; Faunt, L M; MERCADO, M.; Baumann, G

    1993-01-01

    The discovery of a specific high-affinity growth hormone (GH) binding protein (GH-BP) in plasma adds complexity to the dynamics of GH secretion and clearance. Intuitive predictions are that such a protein would damp sharp oscillations in GH concentrations otherwise caused by bursts of GH secretion into the blood volume, prolong the apparent half-life of circulating GH, and contribute a reservoir function. To test these implicit considerations, we formulated an explicit mathematical model of p...

  6. Statistical effects related to low numbers of reacting molecules analyzed for a reversible association reaction A + B = C in ideally dispersed systems: An apparent violation of the law of mass action

    Science.gov (United States)

    Szymanski, R.; Sosnowski, S.; Maślanka, Ł.

    2016-03-01

    Theoretical analysis and computer simulations (Monte Carlo and numerical integration of differential equations) show that the statistical effect of a small number of reacting molecules depends on a way the molecules are distributed among the small volume nano-reactors (droplets in this study). A simple reversible association A + B = C was chosen as a model reaction, enabling to observe both thermodynamic (apparent equilibrium constant) and kinetic effects of a small number of reactant molecules. When substrates are distributed uniformly among droplets, all containing the same equal number of substrate molecules, the apparent equilibrium constant of the association is higher than the chemical one (observed in a macroscopic—large volume system). The average rate of the association, being initially independent of the numbers of molecules, becomes (at higher conversions) higher than that in a macroscopic system: the lower the number of substrate molecules in a droplet, the higher is the rate. This results in the correspondingly higher apparent equilibrium constant. A quite opposite behavior is observed when reactant molecules are distributed randomly among droplets: the apparent association rate and equilibrium constants are lower than those observed in large volume systems, being the lower, the lower is the average number of reacting molecules in a droplet. The random distribution of reactant molecules corresponds to ideal (equal sizes of droplets) dispersing of a reaction mixture. Our simulations have shown that when the equilibrated large volume system is dispersed, the resulting droplet system is already at equilibrium and no changes of proportions of droplets differing in reactant compositions can be observed upon prolongation of the reaction time.

  7. Event and Apparent Horizon Finders for 3+1 Numerical Relativity

    Directory of Open Access Journals (Sweden)

    Thornburg Jonathan

    2007-06-01

    Full Text Available Event and apparent horizons are key diagnostics for the presence and properties of black holes. In this article I review numerical algorithms and codes for finding event and apparent horizons in numerically-computed spacetimes, focusing on calculations done using the 3+1 ADM formalism. The event horizon of an asymptotically-flat spacetime is the boundary between those events from which a future-pointing null geodesic can reach future null infinity and those events from which no such geodesic exists. The event horizon is a (continuous null surface in spacetime. The event horizon is defined nonlocally in time: it is a global property of the entire spacetime and must be found in a separate post-processing phase after all (or at least the nonstationary part of spacetime has been numerically computed.There are three basic algorithms for finding event horizons, based on integrating null geodesics forwards in time, integrating null geodesics backwards in time, and integrating null surfaces backwards in time. The last of these is generally the most efficient and accurate.In contrast to an event horizon, an apparent horizon is defined locally in time in a spacelike slice and depends only on data in that slice, so it can be (and usually is found during the numerical computation of a spacetime. A marginally outer trapped surface (MOTS in a slice is a smooth closed 2-surface whose future-pointing outgoing null geodesics have zero expansion Theta. An apparent horizon is then defined as a MOTS not contained in any other MOTS. The MOTS condition is a nonlinear elliptic partial differential equation (PDE for the surface shape, containing the ADM 3-metric, its spatial derivatives, and the extrinsic curvature as coefficients. Most “apparent horizon” finders actually find MOTSs.There are a large number of apparent horizon finding algorithms, with differing trade-offs between speed, robustness, accuracy, and ease of programming. In axisymmetry, shooting

  8. Kidney Function Decline and Apparent Treatment-Resistant Hypertension in the Elderly

    Science.gov (United States)

    Kaboré, Jean; Metzger, Marie; Helmer, Catherine; Berr, Claudine; Tzourio, Christophe; Massy, Ziad A.; Stengel, Bénédicte

    2016-01-01

    Background Cross-sectional studies show a strong association between chronic kidney disease and apparent treatment-resistant hypertension, but the longitudinal association of the rate of kidney function decline with the risk of resistant hypertension is unknown. Methods The population-based Three-City included 8,695 participants older than 65 years, 4265 of them treated for hypertension. We estimated the odds ratios (OR) of new-onset apparent treatment-resistant hypertension, defined as blood pressure ≥ 140/90 mmHg despite use of 3 antihypertensive drug classes or ≥ 4 classes regardless of blood pressure, associated with the mean estimated glomerular filtration rate (eGFR) level and its rate of decline over 4 years, compared with both controlled hypertension and uncontrolled nonresistant hypertension with ≤ 2 drugs. GFR was estimated with three different equations. Results Baseline prevalence of apparent treatment-resistant hypertension and of controlled and uncontrolled nonresistant hypertension, were 6.5%, 62.3% and 31.2%, respectively. During follow-up, 162 participants developed apparent treatment-resistant hypertension. Mean eGFR decline with the MDRD equation was 1.5±2.9 mL/min/1.73 m² per year: 27.7% of the participants had an eGFR ≥3 and 10.1% ≥ 5 mL/min/1.73 m² per year. After adjusting for age, sex, obesity, diabetes, and cardiovascular history, the ORs for new-onset apparent treatment-resistant hypertension associated with a mean eGFR level, per 15 mL/min/1.73m² drop, were 1.23 [95% confidence interval 0.91–1.64] compared to controlled hypertension and 1.10 [0.83–1.45] compared to uncontrolled nonresistant hypertension; ORs associated with a decline rate ≥ 3 mL/min/1.73m² per year were 1.89 [1.09–3.29] and 1.99 [1.19–3.35], respectively. Similar results were obtained when we estimated GFR with the CKDEPI and the BIS1 equations. ORs tended to be higher for an eGFR decline rate ≥ 5 mL/min/1.73m² per year. Conclusion The speed of

  9. Kidney Function Decline and Apparent Treatment-Resistant Hypertension in the Elderly.

    Directory of Open Access Journals (Sweden)

    Jean Kaboré

    Full Text Available Cross-sectional studies show a strong association between chronic kidney disease and apparent treatment-resistant hypertension, but the longitudinal association of the rate of kidney function decline with the risk of resistant hypertension is unknown.The population-based Three-City included 8,695 participants older than 65 years, 4265 of them treated for hypertension. We estimated the odds ratios (OR of new-onset apparent treatment-resistant hypertension, defined as blood pressure ≥ 140/90 mmHg despite use of 3 antihypertensive drug classes or ≥ 4 classes regardless of blood pressure, associated with the mean estimated glomerular filtration rate (eGFR level and its rate of decline over 4 years, compared with both controlled hypertension and uncontrolled nonresistant hypertension with ≤ 2 drugs. GFR was estimated with three different equations.Baseline prevalence of apparent treatment-resistant hypertension and of controlled and uncontrolled nonresistant hypertension, were 6.5%, 62.3% and 31.2%, respectively. During follow-up, 162 participants developed apparent treatment-resistant hypertension. Mean eGFR decline with the MDRD equation was 1.5±2.9 mL/min/1.73 m² per year: 27.7% of the participants had an eGFR ≥3 and 10.1% ≥ 5 mL/min/1.73 m² per year. After adjusting for age, sex, obesity, diabetes, and cardiovascular history, the ORs for new-onset apparent treatment-resistant hypertension associated with a mean eGFR level, per 15 mL/min/1.73 m² drop, were 1.23 [95% confidence interval 0.91-1.64] compared to controlled hypertension and 1.10 [0.83-1.45] compared to uncontrolled nonresistant hypertension; ORs associated with a decline rate ≥ 3 mL/min/1.73 m² per year were 1.89 [1.09-3.29] and 1.99 [1.19-3.35], respectively. Similar results were obtained when we estimated GFR with the CKDEPI and the BIS1 equations. ORs tended to be higher for an eGFR decline rate ≥ 5 mL/min/1.73 m² per year.The speed of kidney function decline is

  10. Temporal trends in liver transplant centre volume in the USA

    Science.gov (United States)

    Tracy, Elisabeth T; Bennett, Kyla M; Aviki, Emeline M; Pappas, Theodore N; Collins, Bradley H; Tuttle-Newhall, Janet E; Marroquin, Carlos E; Kuo, Paul C; Scarborough, John E

    2009-01-01

    Background: Although prior studies have suggested an inverse association between liver transplant centre volume and postoperative patient mortality, more recent analyses have failed to confirm this association. To date, all studies of the relationship between centre volume and outcomes in liver transplantation have been cross-sectional in design. Objective: The objective of our study was to examine temporal trends in the volume–outcomes relationship for liver transplantation. Methods: We used information obtained from the Scientific Registry of Transplant Recipients (SRTR) programme-specific data reports to examine the outcomes of adult liver transplant recipients stratified by annual centre volume. This relationship between centre volume and patient outcomes was assessed over three consecutive time periods from 2000 through 2007. Results: The overall 25% increase in adult liver transplant volume in the USA from 2000 to 2007 appeared to be distributed fairly equally among existing transplant centres. In the earliest time period of our analysis, high-volume centres achieved superior risk-adjusted 1-year patient outcomes compared with low-volume centres. By the third and most recent time period of the analysis, this discrepancy between the outcomes of high- and low-volume centres was no longer statistically apparent. Conclusions: The relationship between centre volume and patient outcomes for liver transplantation in the USA has become less pronounced over time, suggesting that the use of procedure volume as a marker of liver transplant centre quality cannot be justified. The performance-based review process currently utilized in the USA may have contributed to this diminishing influence of centre volume on liver transplant recipient outcomes. This type of review process should be considered as a potential alternative to the volume-based referral initiatives that have been developed for other non-transplant, complex surgical procedures. PMID:19768146

  11. Micromechanical characterization of small volumes by means of nanoindentation

    OpenAIRE

    Cuadrado Lafoz, Núria

    2013-01-01

    Mechanical characterization of micro-volume systems, as thin films or micro-sized phases embedded in multiphase materials, has attracted special interest in the last decades since different micromechanical techniques have been developed to characterize microdevices and materials at the micro and nano scale and it has become apparent that mechanical properties may depend on the analysis scale. An example is the way a crack grows in a bulk material that is likely to be different from crack ...

  12. A historical estimate of apparent survival of American oystercatcher (Haematopus palliatus) in Virginia

    Science.gov (United States)

    Nol, Erica; Murphy, Sean P.; Cadman, Michael D.

    2012-01-01

    Using mark-recapture models, apparent survival was estimated from older banding and re-sighting data (1978–1983) of American Oystercatchers (Haematopus palliatus) nesting on beaches and in salt marshes of coastal Virginia, USA. Oystercatchers nesting in salt marshes exhibited higher apparent survival (0.94 ±0.03) than birds nesting on beaches (0.81 ±0.06), a difference due to variation in mortality, permanent emigration, or both. Nesting on exposed barrier beaches may subject adults and young to higher risk of predation. These early estimates of adult survival for a species that is heavily monitored along the Atlantic and Gulf Coasts can be used to (1) develop demographic models to determine population stability, (2) compare with estimates of adult survival from populations that have reached carrying capacity, and (3) compare with estimates of survival from other oystercatcher populations and species.

  13. Apparent competition drives community-wide parasitism rates and changes in host abundance across ecosystem boundaries.

    Science.gov (United States)

    Frost, Carol M; Peralta, Guadalupe; Rand, Tatyana A; Didham, Raphael K; Varsani, Arvind; Tylianakis, Jason M

    2016-01-01

    Species have strong indirect effects on others, and predicting these effects is a central challenge in ecology. Prey species sharing an enemy (predator or parasitoid) can be linked by apparent competition, but it is unknown whether this process is strong enough to be a community-wide structuring mechanism that could be used to predict future states of diverse food webs. Whether species abundances are spatially coupled by enemy movement across different habitats is also untested. Here, using a field experiment, we show that predicted apparent competitive effects between species, mediated via shared parasitoids, can significantly explain future parasitism rates and herbivore abundances. These predictions are successful even across edges between natural and managed forests, following experimental reduction of herbivore densities by aerial spraying of insecticide over 20 hectares. This result shows that trophic indirect effects propagate across networks and habitats in important, predictable ways, with implications for landscape planning, invasion biology and biological control. PMID:27577948

  14. Line tension and reduction of apparent contact angle associated with electric double layers

    CERN Document Server

    Dörr, Aaron

    2014-01-01

    The line tension of an electrolyte wetting a non-polar substrate is computed analytically and numerically. The results show that, depending on the value of the apparent contact angle, positive or negative line tension values may be obtained. Furthermore, a significant difference between Young's contact angle and the apparent contact angle measured several Debye lengths remote from the three-phase contact line occurs. When applying the results to water wetting highly charged surfaces, line tension values of the same order of magnitude as found in recent experiments can be achieved. Therefore, the theory presented may contribute to the understanding of line tension measurements and points to the importance of the electrostatic line tension. Being strongly dependent on the interfacial charge density, electrostatic line tension is found to be tunable via the pH value of the involved electrolyte. As a practical consequence, the stability of nanoparticles adsorbed at fluid-fluid interfaces is predicted to be depend...

  15. Improved measurements of the apparent resistivity for small depths in Vertical Electrical Soundings

    Science.gov (United States)

    Faleiro, E.; Asensio, G.; Moreno, J.

    2016-08-01

    In this work, a full simulation of a Vertical Electrical Sounding of a multilayer soil using a Wenner array is performed when both the active and the measurement electrodes consist of bare rod length L buried vertically at ground level. The apparent resistivity is calculated for a wide range of values of the separation between the electrodes using the values of the potential between the measuring electrode and a proposed function that characterizes the behavior of the electrodes used which substantially improves the measurements for small depths. The results allow comparing the values of apparent resistivity obtained by known calculation expressions with the results found by using a characteristic function of the electrodes, which is proposed in this paper. In order to obtain a complete vertical sounding of the soil, the convenience of using adapted methods to the type of electrode used in the sounding is discussed.

  16. A simple expression for the apparent reaction rate of large wood char gasification with steam.

    Science.gov (United States)

    Umeki, Kentaro; Roh, Seon-Ah; Min, Tai-Jin; Namioka, Tomoaki; Yoshikawa, Kunio

    2010-06-01

    A simple expression for the apparent reaction rate of large wood char gasification with steam is proposed. Large char samples were gasified under steam atmosphere using a thermo-balance reactor. The apparent reaction rate was expressed as the product of the intrinsic rate and the effective factor. The effective factor was modified to include the effect of change in char diameter and intrinsic reaction rate during the reaction. Assuming uniform conversion ratio throughout a particle, the simplified reaction scheme was divided into three stages. In the initial stage, the local conversion ratio increases without particle shrinkage. In the middle stage, the particle shrinks following the shrinking core model without change in the local conversion ratio. In the final stage, the local conversion ratio increases without particle shrinkage. The validity of the modified effective value was confirmed by comparison with experimental results. PMID:20144863

  17. Influence of surface conductivity on the apparent zeta potential of calcite

    CERN Document Server

    Li, Shuai; Heberling, Frank; Devau, Nicolas; Jougnot, Damien; Chiaberge, Christophe

    2016-01-01

    Zeta potential is a physicochemical parameter of particular importance in describing the surface electrical properties of charged porous media. However, the zeta potential of calcite is still poorly known because of the difficulty to interpret streaming potential experiments. The Helmholtz-Smoluchowski (HS) equation is widely used to estimate the apparent zeta potential from these experiments. However, this equation neglects the influence of surface conductivity on streaming potential. We present streaming potential and electrical conductivity measurements on a calcite powder in contact with an aqueous NaCl electrolyte. Our streaming potential model corrects the apparent zeta potential of calcite by accounting for the influence of surface conductivity and flow regime. We show that the HS equation seriously underestimates the zeta potential of calcite, particularly when the electrolyte is diluted (ionic strength < 0.01 M) because of calcite surface conductivity. The basic Stern model successfully predicted ...

  18. Thermodynamics of apparent horizon and Friedmann equations in big bounce universe

    Science.gov (United States)

    Liu, Molin; Yang, Yuling; Lu, Jianbo; Xu, Lixin

    2016-05-01

    In this paper, we study a big bounce universe typified by a non-singular big bounce, as opposed to a singular big bang. This cosmological model can describe radiation dominated early universe and matter dominated late universe in FRW model. The connections between thermodynamics and gravity are observed here. In the early stage of both cold and hot universes, we find there is only one geometry containing a 4D de Sitter universe with a general state parameter. We also find the form of the apparent horizon in the early universe strongly depends on the extra dimension, which suggests that the influence of the extra dimension could in principle be found in the early universe. Moreover, we show that in the late stages of both cold and hot universes, the moment when the apparent horizon begins to bounce keeps essentially in step with the behavior of the cosmological scalar factor.

  19. Prediction of Apparent Equivalent Thickness Using the Spontaneous Potential Method and Its Application to Oilfield Development

    Institute of Scientific and Technical Information of China (English)

    Wang Junheng; Pan Zhuping; Sun Shuwen; Guo Lei

    2007-01-01

    The upper spontaneous potential produced by oil and gas accumulation is of a stable potential field, and its intensity is directly proportional to the content of the source and inversely proportional to the radius apart from the source. Theoretical research and practical results show that anomalies of spontaneous potential can indicate oil-bearing sandstone bodies and locate the areas of oil and gas accumulation. In oil areas which have fewer reservoir beds, the petroleum reservoir thickness can be predicted by determining the linear relationship between potential intensity and apparent apparent equivalent thickness can be predicted by the linear equation h= -0.19x+0.74. On the basis of geological research, we use the spontaneous potential method to predict the equivalent thickness, helping in the selection of the most appropriate drill sites to enhance the probability of successful well boring so as to serve the next round development of the oilfield.

  20. A Non-Mainstream Viewpoint on Apparent Superluminal Phenomena in AGN Jet

    Indian Academy of Sciences (India)

    Wen-Po Liu; Li-Yan Liu; Chun-Cheng Wang

    2014-09-01

    The group velocity of light in material around the AGN jet is acquiescently one ( as a unit), but this is only a hypothesis. Here, we re-derive apparent superluminal and Doppler formulas for the general case (it is assumed that the group velocity of light in the uniform and isotropic medium around a jet (a beaming model) is not necessarily equal to one, e.g., Araudo et al. (2010) thought that there may be dense clouds around AGN jet base), and show that the group velocity of light close to one could seriously affect apparent superluminal phenomena and Doppler effect in the AGN jet (when the viewing angle and Lorentz factor take some appropriate values).

  1. Origin of apparent period variations in eclipsing post-common-envelope binaries

    CERN Document Server

    Zorotovic, M

    2012-01-01

    Apparent period variations detected in several eclipsing, close-compact binaries are frequently interpreted as being caused by circumbinary giant planets. This interpretation raises the question of the origin of the potential planets that must have either formed in the primordial circumbinary disk, together with the host binary star, and survived its evolution into a close-compact binary or formed in a post-common-envelope circumbinary disk that remained bound to the post-common-envelope binary (PCEB). Here we combine current knowledge of planet formation and the statistics of giant planets around primordial and evolved binary stars with the theory of close-compact binary star evolution aiming to derive new constraints on possible formation scenarios. We compiled a comprehensive list of observed eclipsing PCEBs, estimated the fraction of systems showing apparent period variations, reconstructed the evolutionary history of the PCEBs, and performed binary population models of PCEBs to characterize their main se...

  2. Avian influenza virus infection in apparently healthy domestic birds in Sokoto, Nigeria

    Directory of Open Access Journals (Sweden)

    Innocent Okwundu Nwankwo

    2012-09-01

    Full Text Available The study was conducted among apparently healthy birds brought from different local government areas, neighbouring states and across international boundaries to the Sokoto central live bird market between October 2008 and March 2009. Tracheal and cloacal swabs were collected from 221 apparently healthy birds comprising 182 chickens, 3 turkeys, 11 guineafowl, 17 ducks and 8 pigeons. These samples were analysed using nested polymerase chain reaction (nPCR to check for the presence of avian influenza virus. An overall prevalence of 1.4% (3 positive cases was detected with two cases observed in chickens and one in a pigeon. The findings indicate the circulation of avian influenza in the study area. This raises concern for human and animal health due to zoonotic and economic implications of this virus.

  3. Priming with real motion biases visual cortical response to bistable apparent motion.

    Science.gov (United States)

    Zhang, Qing-fang; Wen, Yunqing; Zhang, Deng; She, Liang; Wu, Jian-young; Dan, Yang; Poo, Mu-ming

    2012-12-11

    Apparent motion quartet is an ambiguous stimulus that elicits bistable perception, with the perceived motion alternating between two orthogonal paths. In human psychophysical experiments, the probability of perceiving motion in each path is greatly enhanced by a brief exposure to real motion along that path. To examine the neural mechanism underlying this priming effect, we used voltage-sensitive dye (VSD) imaging to measure the spatiotemporal activity in the primary visual cortex (V1) of awake mice. We found that a brief real motion stimulus transiently biased the cortical response to subsequent apparent motion toward the spatiotemporal pattern representing the real motion. Furthermore, intracellular recording from V1 neurons in anesthetized mice showed a similar increase in subthreshold depolarization in the neurons representing the path of real motion. Such short-term plasticity in early visual circuits may contribute to the priming effect in bistable visual perception. PMID:23188797

  4. Pseudomagnitudes and Differential Surface Brightness: Application to the apparent diameter of stars

    CERN Document Server

    Chelli, Alain; Bourgès, Laurent; Mella, Guillaume; Lafrasse, Sylvain; Bonneau, Daniel; Chesneau, Olivier

    2016-01-01

    The diameter of a star is a major observable that serves to test the validity of stellar structure theories. It is also a difficult observable that is mostly obtained with indirect methods since the stars are so remote. Today only ~600 apparent star diameters have been measured by direct methods: optical interferometry and lunar occultations. Accurate star diameters are now required in the new field of exoplanet studies, since they condition the planets' sizes in transit observations, and recent publications illustrate a visible renewal of interest in this topic. Our analysis is based on the modeling of the relationship between measured angular diameters and photometries. It makes use of two new reddening-free concepts: a distance indicator called pseudomagnitude, and a quasi-experimental observable that is independent of distance and specific to each star, called the differential surface brightness (DSB). The use of all the published measurements of apparent diameters that have been collected so far, and a c...

  5. Structure and apparent dispersion of ballistic plasma wave echoes of second order

    International Nuclear Information System (INIS)

    The spatial structure of electron plasma wave echoes is investigated with special regard to the apparent dispersion, i.e. the relation between echo wavelength and frequency. The apparent dispersion is obtained by separately recording echo phase and amplitude, using an r.f.-interferometer combined with a network analyzer. Comparison with theory reveals the ballistic nature of the second order echoes investigated; due to the dispersion as a quantitative measure of the velocity diffusion, it yields furthermore a velocity-independent diffusion coefficient D2 = (1.5 +- 0.5) x 1017 m2 s-3, two orders of magnitude larger than expected from equilibrium theory. The enhanced velocity diffusion can be related to non-equilibrium fluctuations due to ion-acoustic turbulence present in the target plasma. (author)

  6. Relationship between Rice Yield and Apparent Electrical Conductivity of Paddy Soils

    OpenAIRE

    M. H. Ezrin; M. S. M. Amin; A. R. Anuar; Aimrun, W.

    2010-01-01

    Problem statement: Understanding the relationships between rice yield and soil properties such as bulk electrical conductivity is of critical importance in precision farming. The apparent Electrical Conductivity of soil (ECa) is influenced by a combination of physico-chemical properties including soluble salts, clay content and mineralogy, soil water content, bulk density, organic matter and soil temperature. Accordingly, ECa is considered as the most reliable and frequently used tools in pre...

  7. Apparent Temperature and Air Pollution vs. Elderly Population Mortality in Metro Vancouver

    OpenAIRE

    Krstić, Goran

    2011-01-01

    Background Meteorological conditions and air pollution in urban environments have been associated with general population and elderly mortality, showing seasonal variation. Objectives This study is designed to evaluate the relationship between apparent temperature (AT) and air pollution (PM2.5) vs. mortality in elderly population of Metro Vancouver. Methods Statistical analyses are performed on moving sum daily mortality rates vs. moving average AT and PM2.5 in 1-, 2-, 3-, 5-, and 7-day model...

  8. Apparent formation constants of actinide complexes with humic substances determined by solvent extraction

    International Nuclear Information System (INIS)

    Apparent formation constants of Pu(IV) with two kinds of humic substances (HSs) were determined in 0.1M NaClO4 at 25°C using a back-solvent extraction method. The effect of solution conditions, such as the pH, the initial metal and HS concentrations, and the ionic strength, on the formation constants was investigated. The obtained data were compared with the other actinide series. (author)

  9. Clinically apparent eating disorders in young diabetic women: associations with painful neuropathy and other complications.

    OpenAIRE

    Steel, J M; R. J. Young; Lloyd, G G; Clarke, B F

    1987-01-01

    Of 208 young women with insulin dependent diabetes, 15 (7%) had a clinically apparent eating disorder (anorexia nervosa or bulimia), a much higher prevalence than reported in non-diabetic women. Most, but not all, of these patients had a long history of poor glycaemic control. In contrast with previous suggestions, control did not deteriorate after the onset of the eating disorder. There was a high incidence and an early onset of diabetic complications. Eleven of the 15 patients had retinopat...

  10. Apparent digestibility coefficients and consumption of corn silage with and without Bt gene in sheep

    OpenAIRE

    Camila Memari Trava; Mauro Sartori Bueno; Geraldo Balieiro

    2012-01-01

    Corn silage is the most important preserved food for ruminants. The transgenic corn was inserted into the genetic code Bt gene (Bacillus thuringiensis) that expresses a toxic protein to caterpillars pests of maize, reducing production costs. To evaluate the varieties of plant corn silage DKB and AG with or without the Bt gene on the voluntary intake of DM (g/day) and apparent digestibility coefficients (CDA) of nutrients in sheep, the experiment was conducted at the Institute of Animal Scienc...

  11. Discrete fragment model for apparent formation constants of actinide ions with humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takayuki; Yoshida, Hatsumi; Aoyama, Shunsuke; Kobayashi, Taishi; Takagi, Ikuji [Kyoto Univ. (Japan). Dept. of Nuclear Engineering; Moriyama, Hirotake [Kyoto Univ., Osaka (Japan). Research Reactor Inst.

    2015-09-01

    A semi-empirical thermodynamic model was applied to estimate the apparent formation constants of actinide ions, i.e., Th(IV), Pu(IV) and Np(V), with humic substances (HSs), including humic and fulvic acids, over a wide range of solution conditions, i.e., pH, ionic strength, and HS and metal concentrations. The hypothetical HSs consist of humic and fulvic acids with nine types of simple organic ligands, which include aromatic and aliphatic carboxyl groups and phenol groups, as binding sites. The abundance of each binding site in the hypothetical HSs was determined via a fitting analysis using an acid-dissociation dataset for several HSs. To determine the apparent formation constant of a given metal ion with HSs, 54 specific binding sites were considered, including nine monodentate sites (1:1 metal/ligand complexes) and 45 bidentate sites (1:2 metal/ligand complexes). The formation constant of each monodentate binding was determined from the experimental data, while those of the bidentate bindings were determined by considering two monodentate bindings and the chelating effect, for which one of the adjustable parameters was introduced in the model. Introduction of the other parameter, which is related to the fraction of monodentate to bidentate sites (i.e., the heterogeneity), afforded the parameter values with good correlation with the apparent formation constant data. The present model with adjusted parameter values well reproduced the experimental apparent complex formation constants for actinide ion interaction with HSs in a wide range of solution conditions except for those obtained at trace concentrations.

  12. Impact of calcium on salivary α-amylase activity, starch paste apparent viscosity and thickness perception

    OpenAIRE

    Morris, Cecile

    2011-01-01

    Thickness perception of starch-thickened products during eating has been linked to starch viscosity and salivary amylase activity. Calcium is an essential cofactor for α-amylase and there is anecdotal evidence that adding extra calcium affects amylase activity in processes like mashing of beer. The aims of this paper were to (1) investigate the role of salivary calcium on α-amylase activity and (2) to measure the effect of calcium concentration on apparent viscosity and thic...

  13. Effects of apparent temperature on daily mortality in Lisbon and Oporto, Portugal

    OpenAIRE

    Casimiro Elsa; Almeida Sofia P; Calheiros José

    2010-01-01

    Abstract Background Evidence that elevated temperatures can lead to increased mortality is well documented, with population vulnerability being location specific. However, very few studies have been conducted that assess the effects of temperature on daily mortality in urban areas in Portugal. Methods In this paper time-series analysis was used to model the relationship between mean apparent temperature and daily mortality during the warm season (April to September) in the two largest urban a...

  14. Viscometric Flow under Apparent Wall Slip in Parallel-Plate Geometry

    Czech Academy of Sciences Publication Activity Database

    Wein, Ondřej

    2005-01-01

    Roč. 126, 2-3 (2005), s. 105-114. ISSN 0377-0257 R&D Projects: GA ČR(CZ) GA104/01/0545; GA ČR(CZ) GA104/04/0826 Institutional research plan: CEZ:AV0Z40720504 Keywords : apparent wall slip * viscometry * parallel-plate viscometer Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.268, year: 2005

  15. Percentage of apparent sucrose and productive potential of sugar in cane cultivars

    OpenAIRE

    Hélio Francisco Da Silva Neto; Fernando Abackerli De Pauli; Luiz Carlos Tasso Junior; Marcos Omir Marques

    2014-01-01

    The percentage of saccharose apparent "POL" is an important variable for the determination of sugar production, and its value differs among the cultivars, plant parts and growth seasons. The study aimed to compare values of POL and estimate productive potential of sugar in juice extracted from nodes and internodes of the sugarcane cultivars sugar during the 2010/2011 crop season. We used the experimental design of randomized blocks in factorial scheme 3x2x6, with four replications. The main t...

  16. Invasive orbital aspergillosis in an apparently immunocompetent host without evidence of sinusitis

    OpenAIRE

    Jennifer Primeggia; George Cyriac; Princy Kumar

    2012-01-01

    Invasive aspergillosis is uncommon in healthy individuals. We report a case of Aspergillus fumigatus orbital cellulitiswith intracranial extension in an apparently immunocompetent patient with a history of benign lymphoid hyperplasiaof the lacrimal gland. A 68 year-old man with no significant past medical history underwent orbitotomy and biopsy of alacrimal gland mass. Pathology showed benign lymphoid hyperplasia of the lacrimal gland and he completed radiationtherapy. Three months after orbi...

  17. Invasive orbital aspergillosis in an apparently immunocompetent host without evidence sinusitis

    OpenAIRE

    Primeggia, Jennifer; Cyriac, George; Kumar, Princy

    2012-01-01

    Jennifer Primeggia, George Cyriac, Princy Kumar Invasive aspergillosis is uncommon in healthy individuals. We report a case of Aspergillus fumigatus orbital cellulitis with intracranial extension in an apparently immunocompetent patient with a history of benign lymphoid hyperplasia of the lacrimal gland. A 68 year-old man with no signiicant past medical history underwent orbitotomy and biopsy of a lacrimal gland mass. Pathology showed benign lymphoid hyperplasia of ...

  18. Switching between apparently redundant iron-uptake mechanisms benefits bacteria in changeable environments

    OpenAIRE

    Dumas, Z; Ross-Gillespie, A; Kümmerli, Rolf

    2013-01-01

    Bacteria often possess multiple siderophore-based iron uptake systems for scavenging this vital resource from their environment. However, some siderophores seem redundant, because they have limited iron-binding efficiency and are seldom expressed under iron limitation. Here, we investigate the conundrum of why selection does not eliminate this apparent redundancy. We focus on Pseudomonas aeruginosa, a bacterium that can produce two siderophores— the highly efficient but metabolically expensiv...

  19. THE COMPLEX, YET SMALL WORLD OF GLOBAL MULTINATIONALS – INSIGHTS ON SOME APPARENT PARADOXES

    OpenAIRE

    OGREAN Claudia; Herciu, Mihaela

    2013-01-01

    Globalization, as it is today, shapes a complex, networked world – that embeds all the features (both vantages and liabilities) of a complex adaptive system. Being one of the biggest networks that define this world, the system of international business – characterized by diversity, (nondeterministic) interconnectivity and uncertainty – is also characterized by the small-world syndrome. Global multinationals are the best supporting agents in order to dismantle the apparent paradox of the compl...

  20. The effect of measuring procedure on the apparent rheological properties of self-compacting concrete

    DEFF Research Database (Denmark)

    Geiker, Mette Rica; Bradl, M.; Thrane, L.N.;

    2002-01-01

    Torque versus time during testing of the rheological properties of fresh concrete has been investigated. The testing was performed in a BML viscometer and on a self-compacting concrete (w/c = 0.45, 70% rapid hardening Portland cement, 3% silica fume, 27% fly ash, third generation superplasticizer....... Furthermore, lack of steady state may explain the apparent shear-thickening behaviour of self-compacting concrete reported elsewhere. (C) 2002 Elsevier Science Ltd. All rights reserved....

  1. The Correlation between Apparent Diffusion Coefficient and Tumor Cellularity in Patients: A Meta-Analysis

    OpenAIRE

    Chen, Lihua; Liu, Min; Bao, Jing; XIA, YUNBAO; Zhang, Jiuquan; Zhang, Lin; Huang, Xuequan; Jian WANG

    2013-01-01

    Objective To perform a meta-analysis exploring the correlation between the apparent diffusion coefficient (ADC) and tumor cellularity in patients. Materials and Methods We searched medical and scientific literature databases for studies discussing the correlation between the ADC and tumor cellularity in patients. Only studies that were published in English or Chinese prior to November 2012 were considered for inclusion. Summary correlation coefficient (r) values were extracted from each study...

  2. Moisture content effect in the relationship between apparent electrical conductivity and soil attributes

    OpenAIRE

    Marcelo Marques Costa; Daniel Marçal Queiroz; Francisco de Assis de Carvalho Pinto; Elton Fialho dos Reis; Nerilson Terra Santos

    2014-01-01

    To map the spatial variability of a field to define the variable rate application, an intensive sampling of the soil-plant system is necessary. The apparent soil electrical conductivity (ECa) has been used for soil mapping because it correlates well with soil attributes, allows for dense sampling and can be obtained at low cost. However, ECa is influenced by soil moisture content, and the variability of this attribute can reduce the reliability of the ECa maps to explain the physical and chem...

  3. Ureteral Dilatation with No Apparent Cause on Intravenous Urography: Normal or Abnormal? A Pilot Study

    OpenAIRE

    Vinita Rathi; Sachin Agrawal; Shuchi Bhatt; Naveen Sharma

    2015-01-01

    A pilot study was done in 18 adults to assess the significance of ureteral dilatation having no apparent cause seen on Intravenous Urography (IVU). A clinicoradiological evaluation was undertaken to evaluate the cause of ureteral dilatation, including laboratory investigations and sonography of the genitourinary tract. This was followed, if required, by CT Urography (using a modified technique). In 9 out of 18 cases, the cause of ureteral dilatation on laboratory investigations was urinary tr...

  4. Discrete fragment model for apparent formation constants of actinide ions with humic substances

    International Nuclear Information System (INIS)

    A semi-empirical thermodynamic model was applied to estimate the apparent formation constants of actinide ions, i.e., Th(IV), Pu(IV) and Np(V), with humic substances (HSs), including humic and fulvic acids, over a wide range of solution conditions, i.e., pH, ionic strength, and HS and metal concentrations. The hypothetical HSs consist of humic and fulvic acids with nine types of simple organic ligands, which include aromatic and aliphatic carboxyl groups and phenol groups, as binding sites. The abundance of each binding site in the hypothetical HSs was determined via a fitting analysis using an acid-dissociation dataset for several HSs. To determine the apparent formation constant of a given metal ion with HSs, 54 specific binding sites were considered, including nine monodentate sites (1:1 metal/ligand complexes) and 45 bidentate sites (1:2 metal/ligand complexes). The formation constant of each monodentate binding was determined from the experimental data, while those of the bidentate bindings were determined by considering two monodentate bindings and the chelating effect, for which one of the adjustable parameters was introduced in the model. Introduction of the other parameter, which is related to the fraction of monodentate to bidentate sites (i.e., the heterogeneity), afforded the parameter values with good correlation with the apparent formation constant data. The present model with adjusted parameter values well reproduced the experimental apparent complex formation constants for actinide ion interaction with HSs in a wide range of solution conditions except for those obtained at trace concentrations.

  5. Non-equilibrium thermodynamics of dark energy on the power-law entropy corrected apparent horizon

    OpenAIRE

    Farooq, M. Umar; Jamil, Mubasher(School of Natural Sciences (SNS), National University of Science and Technology (NUST), H-12, Islamabad, Pakistan)

    2011-01-01

    We investigate the Friedmann-Robertson-Walker (FRW) universe (containing dark energy) as a non-equilibrium (irreversible) thermodynamical system by considering the power-law correction to the horizon entropy. By taking power-law entropy area law which appear in dealing with the entanglement of quantum fields in and out the horizon, we determine the power-law entropy corrected apparent horizon of the FRW universe.

  6. Apparent ghosts and spurious degrees of freedom in non-local theories

    Energy Technology Data Exchange (ETDEWEB)

    Foffa, Stefano; Maggiore, Michele; Mitsou, Ermis

    2014-06-02

    Recent work has shown that non-local modifications of the Einstein equations can have interesting cosmological consequences and can provide a dynamical origin for dark energy, consistent with existing data. At first sight these theories are plagued by ghosts. We show that these apparent ghost-like instabilities do not describe actual propagating degrees of freedom, and there is no issue of ghost-induced quantum vacuum decay.

  7. Directional Characteristics of Multisegment ED Probes under Apparent Wall-slip (AWS) Effect

    Czech Academy of Sciences Publication Activity Database

    Wein, Ondřej

    Praha: Process Engineering Publisher, 2008, s. 921. ISBN 978-80-02-02050-9. [18th International Congress of Chemical and Process Engineering CHISA 2008. Praha (CZ), 24.08.2008-28.08.2008] R&D Projects: GA ČR GA104/08/0428 Institutional research plan: CEZ:AV0Z40720504 Keywords : apparent wall-slip * a constant wall shear rate Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  8. Apparent plasticity in functional traits determining competitive ability and spatial distribution: a case from desert

    OpenAIRE

    Jiang-Bo Xie; Gui-Qing Xu; G. Darrel Jenerette; Yong-fei Bai; Zhong-Yuan Wang; Yan Li

    2015-01-01

    Species competitive abilities and their distributions are closely related to functional traits such as biomass allocation patterns. When we consider how nutrient supply affects competitive abilities, quantifying the apparent and true plasticity in functional traits is important because the allometric relationships among traits are universal in plants. We propose to integrate the notion of allometry and the classical reaction norm into a composite theoretical framework that quantifies the appa...

  9. Detection of Yersinia spp and Salmonella spp. in apparently healthy cats and dogs in Tehran, Iran

    OpenAIRE

    shabnam hashemi; mohamadreza mahzounieh; mahvash ghorbani

    2016-01-01

    Introduction: Companion animals, such as cat and dog, are potential sources of transmissible diseases to humans, especially children. They harbor zoonotic agents in gastrointestinal tracts as carriers which are capable of infecting their owners. Salmonella and Yersinia bacteria are considered as frequent causes of illness in children. This study was aimed at finding out the prevalence rate of infection in apparently healthy dogs and cats in Tehran, Iran. Materials and methods: A tota...

  10. Exfoliation, cholestasis, and apparent biliary sepsis in a woman with adult-onset diabetes.

    OpenAIRE

    Heiman, D. F.; Levine, R A; Bia, F. J.

    1985-01-01

    In consultation the authors were requested to evaluate a middle-aged diabetic woman for an apparent episode of biliary sepsis. The patient had been admitted to the dermatology service with a four-day history of rash and pruritus. This was initially thought to represent an allergic reaction to dicloxacillin in someone with a previous history of penicillin hypersensitivity. Persistent right upper quadrant pain, fevers, elevations of serum alkaline phosphatase, and a radionuclide scan which did ...

  11. Clinically apparent and occult metastasized seminoma: almost indistinguishable on the transcriptional level.

    Directory of Open Access Journals (Sweden)

    Christian G Ruf

    Full Text Available PURPOSE: The aim of the present study was to examine the biological differences between seminomas with occult and clinically apparent metastases at the time of diagnosis of the primary tumor to gain insight into the biology of these tumors and facilitate the identification of novel predictors of seminoma metastasis. MATERIALS AND METHODS: Total RNA including small RNAs was isolated from testicular tumors of patients with pure seminoma presenting with lymphogenic metastasis (n = 5, clinical stage IIb/c and occult metastasis (n = 5, clinical stage I. The regulation of biological processes was examined (1 throughout the mRNA transcriptome (whole genome microarrays, 8×60 K Array, Agilent with 4 samples/group and (2 the miRNA transcriptome employing small RNA next generation sequencing (SOLID, Life Technologies with 5 samples/group. Protein coding genes (mRNAs and small RNAs showing a significant (≥2-fold difference between the groups were identified. Finally (3, we examined 95 candidate miRNAs in 36 apparent metastasized and another 5 occult metastasized seminoma using logistic regression analysis. RESULTS: Among 19,596 genes, on average 12,894 mRNAs appeared expressed (65.8%, SD+/-2.4; range, 62.0-69.3% and 16.99×106/13.94×106 small RNA reads were identified for apparent/occult metastasized seminoma. These reads on average convert into 9,901/9,675 small RNAs including 422/404 mature microRNAs. None of these mRNAs/small RNAs met our selection criteria for candidate genes. From 95 candidate miRNAs 44 appeared expressed, with 3 of them showing weak but significant (p = 0.05 differences among both groups. CONCLUSIONS: Occult and apparent metastasized seminomas are biologically almost indistinguishable and probably represent no separate tumor entities. These findings may simplify future research on seminoma metastasis.

  12. Definition of management zones in coffee production fields based on apparent soil electrical conductivity

    OpenAIRE

    Domingos Sárvio Magalhães Valente; Daniel Marçal Queiroz; Francisco de Assis de Carvalho Pinto; Nerilson Terra Santos; Fábio Lúcio Santos

    2012-01-01

    Fertilizer application at variable rates requires dense sampling to determine the resulting field spatial variability. Defining management zones is a technique that facilitates the variable-rate application of agricultural inputs. The apparent electrical conductivity of the soil is an important factor in explaining the variability of soil physical-chemical properties. Thus, the objective of this study was to define management zones for coffee (Coffea Arabica L.) production fields based on spa...

  13. On the apparent saturation of the average disorientation angle with plastic deformation

    DEFF Research Database (Denmark)

    Pantleon, W.

    2005-01-01

    Contradictory results have been concluded from transmission electron microscopy studies of disorientations evolving during plastic deformation: whereas saturation of the average disorientation angles across all dislocation boundaries was reported, a continued increase was observed, if different b...... boundary types were distinguished. The apparent saturation is traced to a nontrivial artifact of the evaluation procedure. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved....

  14. Kinetic evidence of an apparent negative activation enthalpy in an organocatalytic process

    KAUST Repository

    Han, Xiao

    2013-08-30

    A combined kinetic and computational study on our tryptophan-based bifunctional thiourea catalyzed asymmetric Mannich reactions reveals an apparent negative activation enthalpy. The formation of the pre-transition state complex has been unambiguously confirmed and these observations provide an experimental support for the formation of multiple hydrogen bonding network between the substrates and the catalyst. Such interactions allow the creation of a binding cavity, a key factor to install high enantioselectivity.

  15. Apparent superluminal advancement of a single photon far beyond its coherence length

    OpenAIRE

    Cialdi, S; Boscolo, I.; CASTELLI, F.; Petrillo, V.

    2008-01-01

    We present experimental results relative to superluminal propagation based on a single photon traversing an optical system, called 4f-system, which acts singularly on the photon's spectral component phases. A single photon is created by a CW laser light down{conversion process. The introduction of a linear spectral phase function will lead to the shift of the photon peak far beyond the coherence length of the photon itself (an apparent superluminal propagation of the photon). Superluminal gro...

  16. The Relationship of Body Composition and Coronary Artery Calcification in Apparently Healthy Korean Adults

    OpenAIRE

    Yu, Jung-Hee; Yim, Seo Hyoung; Yu, Su Hyeon; Lee, Ji Yong; Kim, Jong Dae; Seo, Mi Hae; Jeon, Won Seon; Park, Se-Eun; Park, Cheol-Young; Lee, Won-Young; Oh, Ki-Won; Park, Sung-Woo; Rhee, Eun-Jung

    2013-01-01

    Background We investigated the association of coronary artery calcium score (CACS) with body composition and insulin resistance in apparently healthy Korean adults. Methods Nine hundred forty-five participants (mean age, 48.9 years; 628 men) in a medical check-up program were selected for analysis. Body composition was assessed by bioelectrical impedance analysis (BIA). Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR). The CACS was assess...

  17. The apparent elastic modulus of the juxtarticular subchondral bone of the femoral head.

    Science.gov (United States)

    Brown, T D; Vrahas, M S

    1984-01-01

    An experiment was undertaken to obtain approximate values for the intrinsic elastic modulus of subchondral bone. Shallow spherical caps, with uniform and incrementally controlled thickness, were machined from subchondral bone in the weight-bearing regions of 11 fresh-frozen normal femoral head autopsy specimens. Under application of polar point loads, the measured deflections were compared with a corresponding analytical shell solution, thus allowing back-calculation of the apparent modulus. Analogous tests were performed on similarly shaped specimens of stock Plexiglas of known modulus in order to estimate the precision of the testing method. The aggregate results for subchondral bone showed that its intrinsic stiffness correlated inversely with nominal shell thickness, but even the thinnest (1.0 mm thick) of these shells had an apparent modulus (mean = 1.372 GN/m2, SD = 414 MN/m2) well below that generally accepted for "pure" cortical bone (about 14 GN/m2). This stiffness deficit was very likely due to the presence of histologically evident marrow spaces. However, the low apparent modulus values measured in this study may not be fully representative of complex in vivo behavior, because in the testing of excised shells there is no radial compressive stress transfer to underlying cancellous bone. PMID:6491796

  18. Design of a gonio-spectro-photometer for optical characterization of gonio-apparent materials

    International Nuclear Information System (INIS)

    Gonio-apparent surfaces, characterized by large variations in optical properties with small variations in detection or illuminating directions, have a huge appeal for industrial product for aesthetic reasons. This work is dedicated to the design of a gonio-spectrophotometer (OptiMines goniometer) adequate for analyzing the light reflecting behavior of these challenging surface aspects. Such optical characterizations are useful data for realistic rendering of such surfaces in computer graphics but also for new product development and quality control in industrial manufacturing. To reach the four degrees of freedom necessary to cover the entire reflecting hemisphere, the designed geometrical setup favors movements of the sample so that illuminating and detection arms only carry one degree of freedom each. Having only one degree of freedom on each optical arm enables an easy installation of precise optical systems that leads to a very high directional accuracy for small arm dimensions. High directional accuracy is essential for fine analysis of gonio-apparent surfaces in order to prevent signal averaging with out-of-direction beam, in particular when the property change is abrupt. The analysis of both diffuse and gonio-apparent materials demonstrates the performance in surface metrology provided by this new device. (paper)

  19. Interacting entropy-corrected holographic dark energy with apparent horizon as an infrared cutoff

    Science.gov (United States)

    Khodam-Mohammadi, A.; Malekjani, M.

    2012-05-01

    In this work we consider the entropy-corrected version of interacting holographic dark energy (HDE), in the non-flat universe enclosed by apparent horizon. Two corrections of entropy so-called logarithmic `LEC' and power-law `PLEC' in HDE model with apparent horizon as an IR-cutoff are studied. The ratio of dark matter to dark energy densities u, equation of state parameter w D and deceleration parameter q are obtained. We show that the cosmic coincidence problem is solved for interacting models. By studying the effect of interaction in EoS parameter of both models, we see that the phantom divide may be crossed and also understand that the interacting models can drive an acceleration expansion at the present and future, while in non-interacting case, this expansion can happen only at the early time. The graphs of deceleration parameter for interacting models, show that the present acceleration expansion is preceded by a sufficiently long period deceleration at past. Moreover, the thermodynamical interpretation of interaction between LECHDE and dark matter is described. We obtain a relation between the interaction term of dark components and thermal fluctuation in a non-flat universe, bounded by the apparent horizon. In limiting case, for ordinary HDE, the relation of interaction term versus thermal fluctuation is also calculated.

  20. An Apparent Descriptive Method for Judging the Synchronization of Rotation of Binary Stars

    Indian Academy of Sciences (India)

    Li Lin-sen

    2004-09-01

    The problem of the synchronous rotation of binary stars is judged by using a synchronous parameter introduced in an apparent descriptive method. The synchronous parameter is defined as the ratio of the rotational period to the orbital period. The author suggests several apparent phenomenal descriptive methods for judging the synchronization of rotation of binary stars. The first method is applicable when the orbital inclination is well-known. The synchronous parameter is defined by using the orbital inclination and the observable rotational velocity (1,2 sin ). The method is mainly suitable for eclipsing binary stars. Several others are suggested for the cases when the orbital inclination is unknown. The synchronous parameters are defined by using 1,2 sin , 1,2 sin3 , the mass function () and semi-amplitudes of the velocity curve, 1,2 given in catalogue of parameters of spectroscopic binary systems and (1,2 sin ). These methods are suitable for spectroscopic binary stars including those that show eclipses and visual binary stars concurrently. The synchronous parameters for fifty-five components in thirty binary systems are calculated by using several methods. The numerical results are listed in Tables 1 and 2. The statistical results are listed in Table 3. In addition, several apparent descriptive methods are discussed.

  1. Correlation functions quantify super-resolution images and estimate apparent clustering due to over-counting

    CERN Document Server

    Veatch, Sarah; Shelby, Sarah; Chiang, Ethan; Holowka, David; Baird, Barbara

    2011-01-01

    We present an analytical method to quantify clustering in super-resolution localization images of static surfaces in two dimensions. The method also describes how over-counting of labeled molecules contributes to apparent self-clustering and how the effective lateral resolution of an image can be determined. This treatment applies to clustering of proteins and lipids in membranes, where there is significant interest in using super-resolution localization techniques to probe membrane heterogeneity. When images are quantified using pair correlation functions, the magnitude of apparent clustering due to over-counting will vary inversely with the surface density of labeled molecules and does not depend on the number of times an average molecule is counted. Over-counting does not yield apparent co-clustering in double label experiments when pair cross-correlation functions are measured. We apply our analytical method to quantify the distribution of the IgE receptor (Fc{\\epsilon}RI) on the plasma membranes of chemi...

  2. Apparent cross-field superslow propagation of magnetohydrodynamic waves in solar plasmas

    CERN Document Server

    Kaneko, T; Soler, R; Terradas, J; Van Doorsselaere, T; Yokoyama, T; Wright, A N

    2015-01-01

    In this paper we show that the phase mixing of continuum Alfv\\'{e}n waves and/or continuum slow waves in magnetic structures of the solar atmosphere as, e.g., coronal arcades, can create the illusion of wave propagation across the magnetic field. This phenomenon could be erroneously interpreted as fast magnetosonic waves. The cross-field propagation due to phase mixing of continuum waves is apparent because there is no real propagation of energy across the magnetic surfaces. We investigate the continuous Alfv\\'{e}n and slow spectra in 2D Cartesian equilibrium models with a purely poloidal magnetic field. We show that apparent superslow propagation across the magnetic surfaces in solar coronal structures is a consequence of the existence of continuum Alfv\\'{e}n waves and continuum slow waves that naturally live on those structures and phase mix as time evolves. The apparent cross-field phase velocity is related to the spatial variation of the local Alfv\\'{e}n/slow frequency across the magnetic surfaces and is ...

  3. Comparison between apparent viscosity related to irradiation dose for corn starch and black pepper

    International Nuclear Information System (INIS)

    Dose-effect relationship was studied in the rheoviscometric behaviour of geliffied suspensions of irradiated corn starch and black pepper, as the variation of the apparent viscosity and the shear stress related to the dose. Irradiation has been performed up to 16 kGy. Black pepper was ground and sieved to three particle sizes to analyse also the influence of particle size on the apparent viscosity variation by dose. The rheoviscometric measurements have been carried out by a rotationary viscometer on geliffied suspensions of starch and black pepper, into equivalent starch concentration and alkalinised suspensions for pepper. For starch, shear stress variation by dose is exponential, where the coefficients depend on the shear rate. For black pepper, the curves of apparent viscosity relation to dose also fit an exponential equation and the influence of particle size is discussed, too. Viscometric behaviour similar to irradiation of both corn starch and black pepper could be attributed to starch degradation at relatively high doses and should be used to develop an identification and control method for the ionizing treatment of starch-based food materials. (author)

  4. Ion mobility imaging and contrast mechanism of apparent conductivity in MREIT.

    Science.gov (United States)

    Oh, Tong In; Kim, Young Tae; Minhas, Atul; Seo, Jin Keun; Kwon, Oh In; Woo, Eung Je

    2011-04-01

    Magnetic resonance electrical impedance tomography (MREIT) aims to produce high-resolution cross-sectional images of conductivity distribution inside the human body. Injected current into an imaging object induces a distribution of internal magnetic flux density, which is measured by using an MRI scanner. We can reconstruct a conductivity image based on its relation with the measured magnetic flux density. In this paper, we explain the contrast mechanism in MREIT by performing and analyzing a series of numerical simulations and imaging experiments. We built a stable conductivity phantom including a hollow insulating cylinder with holes. Filling both inside and outside the hollow cylinder with the same saline, we controlled ion mobilities to create a conductivity contrast without being affected by the ion diffusion process. From numerical simulations and imaging experiments, we found that slopes of induced magnetic flux densities change with hole diameters and therefore conductivity contrasts. Associating the hole diameter with apparent conductivity of the region inside the hollow cylinder with holes, we could experimentally validate the contrast mechanism in MREIT. Interpreting reconstructed apparent conductivity images of the phantom as ion mobility images, we discuss the meaning of the apparent conductivity seen by a certain probing method. In designing MREIT imaging experiments, the ion mobility imaging method using the proposed stable conductivity phantom will enable us to estimate a distinguishable conductivity contrast for a given set of imaging parameters. PMID:21411866

  5. Apparent digestibility of three diets in the Amiata breed donkey during lactation

    Directory of Open Access Journals (Sweden)

    Gian Battista Liponi

    2010-01-01

    Full Text Available The aim of the trial was to evaluate the apparent digestibility of three isonitrogenous and isocaloric diets for lactating donkeys: a diet with 8 kg of hay and 1.5 kg of commercial flaked mixed feed (CM (Diet 1; a diet with 7 kg of hay and a 2.2 kg of CM (Diet 2 and a diet with 7 kg of hay, 1.5 kg of CM, 200 ml of corn oil and 0.2 kg of soybean meal (Diet 3. Four pluriparous donkeys (309±12 kg BW at approximately 2-4 months of lactation were used. The trial was conducted according to a 3x3 Latin Square design with 1 or 2 subject per each cell. Feed and faeces samples were analysed for DM, OM, CP, EE, CF, NDF, ADF and gross energy. Acid insoluble ash was used as marker to calculate the apparent digestibility. The apparent digestibility of the main dietary components showed not significant differences among the three diets but generally they were lower in Diet 3. DM intakes of every diet exceeded the esti- mated energy requirement, whereas protein requirements were not significantly satisfied by Diet 1.

  6. THE APPARENT VISCOSITY OF SEMI-SOLID AZ91D ALLOY AT STEADY STATE

    Institute of Scientific and Technical Information of China (English)

    Z.S. Zhen; W.M. Mao; S.J. Yan; A.M. Zhao; C.L. CuI; X.Y. Zhong

    2002-01-01

    The Rheological behavior of semi-solid AZ91D at steady state is studied using a Couettetype viscometer in the present paper. The results show that the apparent viscosity ofsemi-solid AZ91D at the steady state increases with the solid fraction increasing, andgoes up sharply when the solid fraction reaches a certain value, which is called criticalfraction. In addition, the apparent viscosity of semi-solid AZ91D at the steady statetakes on a distinct downtrend with the shearing rate increasing, which indicates astrong shear thinning property. In addition, the critical solid fraction becomes higherunder larger shearing rate, owing to the more globular shape of the solid particles.Based on the present experiment results, an empirical equation is built as that, relatingthe steady state apparent viscosity of semi-solid AZ91D with the solid fraction fs andshearing rate γ at the same time: ηapp=10. 74exp(6.95fs)γ-0.86.

  7. Most apparent distortion: full-reference image quality assessment and the role of strategy

    Science.gov (United States)

    Larson, Eric C.; Chandler, Damon M.

    2010-01-01

    The mainstream approach to image quality assessment has centered around accurately modeling the single most relevant strategy employed by the human visual system (HVS) when judging image quality (e.g., detecting visible differences, and extracting image structure/information). In this work, we suggest that a single strategy may not be sufficient; rather, we advocate that the HVS uses multiple strategies to determine image quality. For images containing near-threshold distortions, the image is most apparent, and thus the HVS attempts to look past the image and look for the distortions (a detection-based strategy). For images containing clearly visible distortions, the distortions are most apparent, and thus the HVS attempts to look past the distortion and look for the image's subject matter (an appearance-based strategy). Here, we present a quality assessment method [most apparent distortion (MAD)], which attempts to explicitly model these two separate strategies. Local luminance and contrast masking are used to estimate detection-based perceived distortion in high-quality images, whereas changes in the local statistics of spatial-frequency components are used to estimate appearance-based perceived distortion in low-quality images. We show that a combination of these two measures can perform well in predicting subjective ratings of image quality.

  8. Effects of inhomogeneities on apparent cosmological observables: ''fake'' evolving dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Antonio Enea [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); National Taiwan University, Leung Center for Cosmology and Particle Astrophysics, Taipei, Taiwan (China); The University of Tokyo, Research Centre for the Early Universe (RESCEU), Graduate School of Science, Tokyo (Japan); Starobinsky, Alexei A. [L. D. Landau Institute for Theoretical Physics, Moscow (Russian Federation); The University of Tokyo, Research Centre for the Early Universe (RESCEU), Graduate School of Science, Tokyo (Japan); Sasaki, Misao [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan)

    2012-12-15

    Using the exact Lemaitre-Bondi-Tolman solution with a non-vanishing cosmological constant {Lambda}, we investigate how the presence of a local spherically symmetric inhomogeneity can affect apparent cosmological observables, such as the deceleration parameter or the effective equation of state of dark energy (DE), derived from the luminosity distance under the assumption that the real space-time is exactly homogeneous and isotropic. The presence of a local underdensity is found to produce apparent phantom behavior of DE, while a locally overdense region leads to apparent quintessence behavior. We consider relatively small large scale inhomogeneities which today are not linear and could be seeded by primordial curvature perturbations compatible with CMB bounds. Our study shows how observations in an inhomogeneous {Lambda}CDM universe with initial conditions compatible with the inflationary beginning, if interpreted under the wrong assumption of homogeneity, can lead to the wrong conclusion about the presence of ''fake'' evolving dark energy instead of {Lambda}. (orig.)

  9. Blood parameters and apparent digestibility of concentrate with rice oil for horses

    Directory of Open Access Journals (Sweden)

    Helio Alberto Cumani Garcia

    2013-10-01

    Full Text Available Apparent digestibility coefficients and serum parameters were measured to evaluate the effect of supplementing feed concentrates with rice bran oil in horses. Twelve horses (6 males and 6 females with a mean age of 18 ± 4 months old and mean live weight of 306 ± 22.6 kg were used. Treatments consisted of increasing rice bran oil concentrate levels of 0, 3.5, 7.0, 10.5, 14.0 and 17.5%, considering a daily intake of 2.25% live weight on a dry matter basis. A dietary effect of supplementation on the apparent digestibility of gross energy (y = 64.55 - 0.58x was observed (P0.05. Supplementation did not affect serum glucose levels (P>0.05, but cholesterol was affected (P0.05. A dietary effect on the triglyceride (y = 15.73 - 0.96x + 0.0524x² and HDL (high-density lipoprotein (y = 45.24 + 1.0499x parameters was observed (P<0.01. While the use of rice bran oil does affect blood parameters associated with lipid metabolism, rice bran oil levels up to 17.5% concentrate do not negatively affect the apparent digestibility of dietary nutrients.

  10. Vaccination Programs for Endemic Infections: Modelling Real versus Apparent Impacts of Vaccine and Infection Characteristics

    Science.gov (United States)

    Ragonnet, Romain; Trauer, James M.; Denholm, Justin T.; Geard, Nicholas L.; Hellard, Margaret; McBryde, Emma S.

    2015-10-01

    Vaccine effect, as measured in clinical trials, may not accurately reflect population-level impact. Furthermore, little is known about how sensitive apparent or real vaccine impacts are to factors such as the risk of re-infection or the mechanism of protection. We present a dynamic compartmental model to simulate vaccination for endemic infections. Several measures of effectiveness are calculated to compare the real and apparent impact of vaccination, and assess the effect of a range of infection and vaccine characteristics on these measures. Although broadly correlated, measures of real and apparent vaccine effectiveness can differ widely. Vaccine impact is markedly underestimated when primary infection provides partial natural immunity, when coverage is high and when post-vaccination infectiousness is reduced. Despite equivalent efficacy, ‘all or nothing’ vaccines are more effective than ‘leaky’ vaccines, particularly in settings with high risk of re-infection and transmissibility. Latent periods result in greater real impacts when risk of re-infection is high, but this effect diminishes if partial natural immunity is assumed. Assessments of population-level vaccine effects against endemic infections from clinical trials may be significantly biased, and vaccine and infection characteristics should be considered when modelling outcomes of vaccination programs, as their impact may be dramatic.

  11. Detection and apparent survival of PIT-tagged stream fish in winter.

    Science.gov (United States)

    Weber, Christine; Scheuber, Hannes; Nilsson, Christer; Alfredsen, Knut T

    2016-04-01

    Environmental fluctuations exert strong control on behavior, survival, and fitness of stream biota. Technical improvements increasingly allow for tracking the response of large numbers of individuals to environmental fluctuations, for instance, by remote detection of animals equipped with PIT (passive integrated transponder) tags. PIT tags were implanted into 393 juvenile and adult brown trout Salmo trutta L. and European sculpin Cottus gobio L. in a boreal stream subjected to considerable ice formation. With weekly trackings over 6 months, we quantified apparent survival and detection probability in relation to biological, environmental, and methodological factors. Individuals with a higher physical condition in autumn showed a higher apparent survival; this pattern was consistent across all species and age classes. Detection probability decreased with increasing thickness of the surface ice layer; this effect was most pronounced for juvenile trout and benthic-living sculpin, both tagged with smaller-sized tags. Detection probability was reduced in structurally complex habitats. Our study demonstrates that apparent survival and particularly detection probability may show pronounced spatiotemporal variation. In order to compare results from different sampling occasions and sites, a good knowledge of the study site and of the regulating factors is crucial. PMID:27066238

  12. Determination of Apparent Amylose Content in Rice by Using Paper-Based Microfluidic Chips.

    Science.gov (United States)

    Hu, Xianqiao; Lu, Lin; Fang, Changyun; Duan, Binwu; Zhu, Zhiwei

    2015-11-11

    Determination of apparent amylose content in rice is a key function for rice research and the rice industry. In this paper, a novel approach with paper-based microfluidic chip is reported to determine apparent amylose content in rice. The conventional color reaction between amylose and iodine was employed. Blue color of amylose-iodine complex generated on-chip was converted to gray and measured with Photoshop after the colored chip was scanned. The method for preparation of the paper chip is described. In situ generation of iodine for on-chip color reaction was designed, and factors influencing color reaction were investigated in detail. Elimination of yellow color interference of excess iodine by exploiting color removal function of Photoshop was presented. Under the optimized conditions, apparent amylose content in rice ranging from 1.5 to 26.4% can be determined, and precision was 6.3%. The analytical results obtained with the developed approach were in good agreement with those with the continuous flow analyzer method. PMID:26495809

  13. Bronchoscopic lung volume reduction

    Directory of Open Access Journals (Sweden)

    M. I. Polkey

    2006-12-01

    Full Text Available Surgical lung volume reduction can improve exercise performance and forced expiratory volume in one second in patients with emphysema. However, the procedure is associated with a 5% mortality rate and a nonresponse rate of 25%. Accordingly, interest has focused on alternative ways of reducing lung volume. Two principle approaches are used: collapse of the diseased area using blockers placed endobronchially and the creation of extrapulmonary pathways. Preliminary data from the former approach suggest that it can be successful and that the magnitude of success is related to reduction in dynamic hyperinflation.

  14. Effects of surface and volume production on emittance in a volume type negative ion source

    International Nuclear Information System (INIS)

    A volume-type negative ion source has been modeled using a version of the Negative Ion Injector Design Analysis Program (NIIDeAP). The purpose of the study was to investigate the relative effects of surface-produced ions and volume-produced ions on the emittance of the total extracted beam. The differences between the two types of ion production can be expected to influence energy and emittance distributions for several reasons. Even though the fundamental physics of ion production in the source imply a low temperature, the effects of magnetic field, internal surface geometry, plasma potential, and superposition of two different populations can result in a significant increase of the apparent temperature. A high precision ion trajectory integrator was used. (Author) 5 figs., 5 refs

  15. The apparent diffusion coefficient of a primary lesion correlates with local failure of head and neck squamous cell carcinoma treated with radiotherapy. President award proceedings

    International Nuclear Information System (INIS)

    We prospectively investigated whether the value of the apparent diffusion coefficient (ADC) of a primary lesion prior to treatment correlated with local failure of head and neck squamous cell carcinoma (HNSCC) following radiotherapy. In 17 patients who underwent radiotherapy for primary HNSCC, we compared variables considered to affect local failure, including parameters related to magnetic resonance (MR) imaging, such as ADC and its alteration ratio, between cases of local failure and controls and analyzed survival among those patients in whom the variables differed or demonstrated association with local failure. We also retrospectively analyzed variables in a validation study of 40 patients. In the prospective study, pretreatment values of ADChigh (calculated with b-values of 300, 500, 750, and 1000 s/mm2) alone showed significant association with local failure (P=0.0186). In the validation study, pretreatment values of tumor volume (P=0.0217) and ADChigh (P=0.0001) were significantly associated with local failure. Pretreatment ADChigh was superior to pretreatment tumor volume regarding association with local failure. These results suggest that pretreatment values of both ADC obtained using high b-values and tumor volume correlate with local failure of HNSCC treated with radiotherapy. (author)

  16. The Effect of the Operating Conditions on the Apparent Viscosity of Crude Palm Oil During Oil Clarification

    OpenAIRE

    2012-01-01

    This paper discusses the apparent viscosity of crude palm oil, using rotary viscometer, under different boundary conditions. It was experimentally shown that the apparent viscosity of palm oil drops with increasing of the shear rate and the temperature.  However, the effect of temperature on the viscosity tends to fade at temperatures beyond 80 oC.  A correlation between the apparent viscosity of crude palm oil and the operating conditions was developed. This correlation can be used...

  17. Integers annual volume 2013

    CERN Document Server

    Landman, Bruce

    2014-01-01

    ""Integers"" is a refereed online journal devoted to research in the area of combinatorial number theory. It publishes original research articles in combinatorics and number theory. This work presents all papers of the 2013 volume in book form.

  18. Cooking the volumes

    OpenAIRE

    Sparavigna, Amelia Carolina

    2012-01-01

    Cooking possesses a system of units of measurement, that includes measures of volumes based on pre-metric units. This paper discusses the cooking measures and compares their features with those of the ancient Roman measures of capacity.

  19. Environmental chemistry: Volume A

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.

    1999-08-01

    This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.

  20. New volume and inverse volume operators for loop quantum gravity

    OpenAIRE

    Yang, Jinsong; Ma, Yongge

    2016-01-01

    A new alternative volume operator is constructed for loop quantum gravity by using the so-called co-triad operators as building blocks. It is shown that the new volume operator shares the same qualitative properties with the standard volume operator. Moreover, a new alternative inverse volume operator is also constructed in the light of the construction of the alternative volume operator, which is possessed of the same qualitative properties as those of the alternative volume operator. The ne...

  1. Towards the amplituhedron volume

    OpenAIRE

    Ferro, Livia; Lukowski, Tomasz; Orta, Andrea; Parisi, Matteo

    2016-01-01

    It has been recently conjectured that scattering amplitudes in planar N = 4 $$ \\mathcal{N}=4 $$ super Yang-Mills are given by the volume of the (dual) amplituhedron. In this paper we show some interesting connections between the tree-level amplituhedron and a special class of differential equations. In particular we demonstrate how the amplituhedron volume for NMHV amplitudes is determined by these differential equations. The new formulation allows for a straightforward geometric description,...

  2. Volume anomaly in ferrimagnetism

    OpenAIRE

    Pascard, H.; Globus, A.

    1981-01-01

    The volume anomaly ΔV/V due to the magnetic energy corresponding to the exchange interactions is experimentally determined for YIG. The experimental values (from 77 K to Tc) agree with the values deduced from the theoretical expression based on the Néel's theories of volume anomaly and of ferrimagnetism. These results are compared with those obtained by other authors on ferromagnetic and antiferromagnetic materials with localized magnetic moments : a reduced curve is obtained.

  3. Volume holographic memory

    OpenAIRE

    Cornelia Denz; K. O. Muller; F. Visinka; Berger, G; T. Tschudi

    2000-01-01

    Volume holography represents a promising alternative to existing storage technologies. Its parallel data storage leads to high capacities combined with short access times and high transfer rates. The design and realization of a compact volume holographic storage demonstrator is presented. The technique of phase-coded multiplexing implemented to superimpose many data pages in a single location enables to store up to 480 holograms per storage location without any moving parts. Results of analog...

  4. The tissue volume factor in radiation oncology

    International Nuclear Information System (INIS)

    The concept of radiation injury as a randomly distributed quantal event arising in one or more volume elements, each reacting independently of its neighbors, is unfamiliar to radiotherapists. Nevertheless, the model does provide a realistic estimate of the risk of late effects in many situations and is apparently compatible with the observed dependence on field size. On the other hand there is evidence that this model is not applicable to acute reactions, which appear in the entire irradiated volume diffusely and are markedly dependent upon the inclusion of adjacent tissues. A ''reciprocal vicinity effect'' has been demonstrated in which the observed skin reaction was intensified by irradiation of adjacent fields. Similarly, separating contiguous irradiated areas by shielded zones (using grids or sieves) increased the tolerance of large skin portals, presumably because of replenishment of the depleted cell populations by proliferation and migration of surrounding unaffected cells. There appears to be a reasonable concordance between a statistical model relating normal tissue tolerance to treated volume and the empirical parameters derived from clinical observation of tolerance limits in irradiated normal tissues and organs. There is no obvious mathematical link between the stochastic and empirical models, and the concordance between them may be coincidental. However, the stochastic model may be useful for estimating the risks of complication and recurrence and could provide an algorithm for minimizing the total risk of failure

  5. Reachable volume RRT

    KAUST Repository

    McMahon, Troy

    2015-05-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  6. Sonographic Quantification of Ovarian Volumes in an adult Nigeria population

    Directory of Open Access Journals (Sweden)

    Dr. Nzotta Christian

    2009-01-01

    Full Text Available This study was conducted to establish the normal values of ovarian volumes in this locality. A convenience sample of 141 apparently and gynecologically healthy and non pregnant females was studied using transabdominal sonography. The length, width and anteroposterior dimensions of both the right and left ovaries were measured. Volumes of the ovaries were determined using the prolate ellipsoid formula. The mean ovarian volumes were found to be a 9.5cm3 and 10.cm3 for the right and left ovaries respectively. A mean ovarian volume (Right and left was 9.9cm3. A mean (right and left range of 5.3cm3 to 13.9cm3 was also established. Significant correlations were noted between ovarian volumes and age (r=0.93, p<0.05 and between ovarian volumes and body weight (r=0.73, p<0.05. This study has established a nomogram for ovarian sizes in this locality which would offer a valid method of evaluating ovarian volumes in clinical practice.

  7. Temperature and depth mediate resource competition and apparent competition between Mysis diluviana and kokanee.

    Science.gov (United States)

    Schoen, Erik R; Beauchamp, David A; Buettner, Anna R; Overman, Nathanael C

    2015-10-01

    In many food webs, species in similar trophic positions can interact either by competing for resources or boosting shared predators (apparent competition), but little is known about how the relative strengths of these interactions vary across environmental gradients. Introduced Mysis diluviana shrimp interact with planktivorous fishes such as kokanee salmon (lacustrine Oncorhynchus nerka) through both of these pathways, and effective management depends on understanding which interaction is more limiting under different conditions. An "environmental matching" hypothesis predicts the ecological impacts of Mysis are maximized under cool conditions near its thermal optimum. In addition, we hypothesized Mysis is more vulnerable to predation by lake trout in relatively shallow waters, and therefore Mysis enhances lake trout density and limits kokanee through apparent competition more strongly in shallower habitats. We tested whether these hypotheses could explain food web differences between two connected lake basins, one relatively shallow and the other extremely deep. The shallower basin warmed faster, thermally excluded Mysis from surface waters for 75% longer, and supported 2.5-18 times greater seasonal production of cladoceran zooplankton than the deeper basin, standardized by surface area. Mysis consumed 14-22% less zooplankton in the shallower basin, and lower ratios of total planktivore consumption to zooplankton production (C:P) indicated less potential for resource competition with kokanee, consistent with environmental matching. Lake trout diets contained more Mysis in the shallower basin and at shallower sampling sites within both basins. The catch rate of lake trout was seven times greater and the predation risk for kokanee was 4-5 times greater in the shallower basin than in the deeper basin, consistent with stronger apparent competition in shallower habitats. Understanding how the strengths of these interactions are mediated by temperature and depth would

  8. Effects of apparent temperature on daily mortality in Lisbon and Oporto, Portugal

    Directory of Open Access Journals (Sweden)

    Casimiro Elsa

    2010-03-01

    Full Text Available Abstract Background Evidence that elevated temperatures can lead to increased mortality is well documented, with population vulnerability being location specific. However, very few studies have been conducted that assess the effects of temperature on daily mortality in urban areas in Portugal. Methods In this paper time-series analysis was used to model the relationship between mean apparent temperature and daily mortality during the warm season (April to September in the two largest urban areas in Portugal: Lisbon and Oporto. We used generalized additive Poisson regression models, adjusted for day of week and season. Results Our results show that in Lisbon, a 1°C increase in mean apparent temperature is associated with a 2.1% (95%CI: 1.6, 2.5, 2.4% (95%CI: 1.7, 3.1 and 1.7% (95%CI: 0.1, 3.4 increase in all-causes, cardiovascular, and respiratory mortality, respectively. In Oporto the increase was 1.5% (95%CI: 1.0, 1.9, 2.1% (95%CI: 1.3, 2.9 and 2.7% (95%CI: 1.2, 4.3 respectively. In both cities, this increase was greater for the group >65 years. Conclusion Even without extremes in apparent temperature, we observed an association between temperature and daily mortality in Portugal. Additional research is needed to allow for better assessment of vulnerability within populations in Portugal in order to develop more effective heat-related morbidity and mortality public health programs.

  9. Increasing nitrogen rates in rice and its effect on plant nutrient composition and nitrogen apparent recovery

    Directory of Open Access Journals (Sweden)

    Juan Hirzel

    2013-12-01

    Full Text Available Rice (Oryza sativa L. is one of the essential foods of the human diet; advances in agronomic crop management can improve productivity and profitability as well as reduce adverse environmental impacts. Nitrogen rates in Chile are generally based on crop yield without considering other agronomic factors. The objective of this experiment was to determine the effect of increasing N rates on plant nutrient composition and N apparent recovery in rice cultivated in five different locations in Chile. The five sites located in central Chile belong to one of the following soil orders: Inceptisol, Alfisol, and Vertisol; they were cropped in field conditions with 'Zafiro-INIA' rice fertilized with 0, 80, and 160 kg N ha-1. Whole-plant total DM, macronutrient composition, and N apparent recovery efficiency (NARE were determined at grain harvest. Results indicate that all evaluated parameters, with the exception of K concentration, were affected by the soil used. Nitrogen rates only affected total DM production and P, K, and Mg concentrations in plants. Phosphorus and K response decreased when N was added to some soils, which is associated with its chemical properties. Magnesium concentration exhibited an erratic effect, but it was not affected by the N rate in most soils. Nitrogen apparent recovery efficiency was not affected by the N rate and accounted for approximately 49% and 41% for 80 and 160 kg N ha-1, respectively. Macronutrient composition was 5.1-7.7 g N, 1.3-1.8 g P, 5.4-10.8 g K, 1.68-2.57 g Ca, and 0.81-1.45 g Mg kg-1 of total DM.

  10. Distribution of CD4 lymphocyte cells among apparently healthy HIV seropositive and seronegative populations

    Directory of Open Access Journals (Sweden)

    Abdulazeez A Abubakar

    2012-01-01

    Full Text Available Background: CD4 lymphocyte cells are often used as prognostic markers for monitoring the progression of immunosupression such as HIV infection. Aim: This study was conducted to assess the distribution of CD4 lymphocytes among apparently healthy human immunodeficiency virus (HIV seronegative and seropositive populations in a Nigerian state. Materials and Methods: A total of 1520 apparently healthy subjects aged 18-64 years, composed of 800 males and 720 females attending some selected health institutions in the state, participated in the study. Ten milliliters of blood was collected from each subject; 5 ml of this was used for HIV antibodies sero-typing while the remaining 5 ml was anticoagulated and used for CD4 lymphocytes level determination. Only samples tested positive both with Capillus and Determine HIV test kits were further differentiated into sero-types with a standard diagnostic HIV test kit. The CD4 lymphocyte levels of all the sample were determined; mean CD4 levels of 205.1±0.09 and 287.4±0.3 cells/μl were recorded among females seropositives and seronagatives respectively. Statistical analysis by the Student t-test showed a significant difference in the mean CD4 lymphocyte count by gender. Results: Findings showed a mean CD4 level of 311.7±1.2 cells/μl among seropositive males while 399.3±0.6 cells/μl was recorded among seronegatives (t=5.86. The study also recorded a CD4 lymphocyte range of 232-464 cells/μl among apparently healthy seronegative population in this locality. Conclusion: The findings showed a significantly higher mean CD4 lymphocyte count among adult male HIV seronegatives (χ2= 9.22 and seropositives (χ2=15.07 than their female counterparts. Further research work using the automation technique is suggested to confirm this new range for monitoring HIV subjects on antiretroviral therapy.

  11. Origin of apparent period variations in eclipsing post-common-envelope binaries

    Science.gov (United States)

    Zorotovic, M.; Schreiber, M. R.

    2013-01-01

    Context. Apparent period variations detected in several eclipsing, close-compact binaries are frequently interpreted as being caused by circumbinary giant planets. This interpretation raises the question of the origin of the potential planets that must have either formed in the primordial circumbinary disk, together with the host binary star, and survived its evolution into a close-compact binary or formed in a post-common-envelope circumbinary disk that remained bound to the post-common-envelope binary (PCEB). Aims: Here we combine current knowledge of planet formation and the statistics of giant planets around primordial and evolved binary stars with the theory of close-compact binary star evolution aiming to derive new constraints on possible formation scenarios. Methods: We compiled a comprehensive list of observed eclipsing PCEBs, estimated the fraction of systems showing apparent period variations, reconstructed the evolutionary history of the PCEBs, and performed binary population models of PCEBs to characterize their main sequence binary progenitors. We reviewed the currently available constraints on the fraction of PCEB progenitors that host circumbinary giant planets. Results: We find that the progenitors of PCEBs are very unlikely to be frequent hosts of giant planets (≲10 per cent), while the frequency of PCEBs with observed apparent period variations is very high (~90 per cent). Conclusions: The variations in eclipse timings measured in eclipsing PCEBs are probably not caused by first-generation planets that survived common-envelope evolution. The remaining options for explaining the observed period variations are second-generation planet formation or perhaps variations in the shape of a magnetically active secondary star. We suggest observational tests for both options. Appendix A is available in electronic form at http://www.aanda.org

  12. ASSESSING THE SIGNIFICANCE OF APPARENT CORRELATIONS BETWEEN RADIO AND GAMMA-RAY BLAZAR FLUXES

    International Nuclear Information System (INIS)

    Whether or not a correlation exists between the radio and gamma-ray flux densities of blazars is a long-standing question, and one that is difficult to answer confidently because of various observational biases, which may either dilute or apparently enhance any intrinsic correlation between radio and gamma-ray luminosities. We introduce a novel method of data randomization to evaluate quantitatively the effect of these biases and to assess the intrinsic significance of an apparent correlation between radio and gamma-ray flux densities of blazars. The novelty of the method lies in a combination of data randomization in luminosity space (to ensure that the randomized data are intrinsically, and not just apparently, uncorrelated) and significance assessment in flux space (to explicitly avoid Malmquist bias and automatically account for the limited dynamical range in both frequencies). The method is applicable even to small samples that are not selected with strict statistical criteria. For larger samples we describe a variation of the method in which the sample is split in redshift bins, and the randomization is applied in each bin individually; this variation is designed to yield the equivalent to luminosity-function sampling of the underlying population in the limit of very large, statistically complete samples. We show that for a smaller number of redshift bins, the method yields a worse significance, and in this way it is conservative: although it may fail to confirm an existing intrinsic correlation in a small sample that cannot be split into many redshift bins, it will not assign a stronger, artificially enhanced significance. We demonstrate how our test performs as a function of number of sources, strength of correlation, and number of redshift bins used, and we show that while our test is robust against common-distance biases and associated false positives for uncorrelated data, it retains the power of other methods in rejecting the null hypothesis of no

  13. ASSESSING THE SIGNIFICANCE OF APPARENT CORRELATIONS BETWEEN RADIO AND GAMMA-RAY BLAZAR FLUXES

    Energy Technology Data Exchange (ETDEWEB)

    Pavlidou, V.; Richards, J. L.; Max-Moerbeck, W.; King, O. G.; Pearson, T. J.; Readhead, A. C. S.; Reeves, R.; Stevenson, M. A. [California Institute of Technology, Owens Valley Radio Observatory, Pasadena, CA 91125 (United States); Angelakis, E.; Fuhrmann, L.; Zensus, J. A. [Max-Planck-Institut fuer Radioastronomie, Bonn 53121 (Germany); Giroletti, M. [INAF Istituto di Radioastronomia, Bologna (Italy); Reimer, A. [Institut fuer Astro- und Teilchenphysik and Institut fuer Theoretische Physik, Leopold-Franzes-Universitaet Innsbruck, Innsbruck,Austria (Austria); Healey, S. E.; Romani, R. W.; Shaw, M. S. [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305 (United States)

    2012-06-01

    Whether or not a correlation exists between the radio and gamma-ray flux densities of blazars is a long-standing question, and one that is difficult to answer confidently because of various observational biases, which may either dilute or apparently enhance any intrinsic correlation between radio and gamma-ray luminosities. We introduce a novel method of data randomization to evaluate quantitatively the effect of these biases and to assess the intrinsic significance of an apparent correlation between radio and gamma-ray flux densities of blazars. The novelty of the method lies in a combination of data randomization in luminosity space (to ensure that the randomized data are intrinsically, and not just apparently, uncorrelated) and significance assessment in flux space (to explicitly avoid Malmquist bias and automatically account for the limited dynamical range in both frequencies). The method is applicable even to small samples that are not selected with strict statistical criteria. For larger samples we describe a variation of the method in which the sample is split in redshift bins, and the randomization is applied in each bin individually; this variation is designed to yield the equivalent to luminosity-function sampling of the underlying population in the limit of very large, statistically complete samples. We show that for a smaller number of redshift bins, the method yields a worse significance, and in this way it is conservative: although it may fail to confirm an existing intrinsic correlation in a small sample that cannot be split into many redshift bins, it will not assign a stronger, artificially enhanced significance. We demonstrate how our test performs as a function of number of sources, strength of correlation, and number of redshift bins used, and we show that while our test is robust against common-distance biases and associated false positives for uncorrelated data, it retains the power of other methods in rejecting the null hypothesis of no

  14. Effects of forage family on apparent ruminal synthesis of B vitamins in lactating dairy cows.

    Science.gov (United States)

    Castagnino, D S; Seck, M; Beaudet, V; Kammes, K L; Linton, J A Voelker; Allen, M S; Gervais, R; Chouinard, P Y; Girard, C L

    2016-03-01

    Effects of forage family (legume vs. grass) on apparent ruminal synthesis (ARS) and postruminal supply of B vitamins were evaluated in 2 experiments. Diets containing either alfalfa (AL) or orchardgrass (OG) silages as the sole forage were offered to ruminally and duodenally cannulated lactating Holstein cows in crossover design experiments. Experiment 1 compared diets containing AL and OG [~23% forage neutral detergent fiber (NDF) and ~27% total NDF] offered to 8 cows in two 15-d treatment periods. Experiment 2 compared diets containing AL and OG (~25% forage NDF and ~30% total NDF) offered to 13 cows in two 18-d treatment periods. Thiamin, riboflavin, niacin, vitamin B6, folates, and vitamin B12 were analyzed in feeds and duodenal digesta. Apparent ruminal synthesis was calculated as the duodenal flow of each vitamin minus its intake. Forage family affected B vitamin intakes, duodenal flow, and ARS. In both experiments, AL diets increased vitamin B6 and decreased folate intakes. In experiment 1, riboflavin and niacin intakes were greater with the OG diet, whereas in experiment 2 thiamin intake was greater but riboflavin intake was smaller with the OG diet. In spite of the low contribution of either silage to the dietary folate content, folate intake was greater with OG diets than AL due to the difference in soybean meal contribution between diets. Niacin and folate ARS were not affected by the forage family. Duodenal microbial nitrogen flow was positively correlated with ARS of riboflavin, niacin, vitamin B6, folates, and vitamin B12, but tended to be negatively correlated with thiamin ARS. Apparent ruminal synthesis of folates and vitamin B12 appear to be related to microbial biomass activity. Changes in nutrient composition of the diets likely affected the microbial population in the rumen and their B vitamin metabolism. PMID:26774713

  15. Tortoise Coordinate Transformation on Apparent Horizon of a Dynamical Black Hole

    Science.gov (United States)

    Liu, Xianming; Zhao, Zheng; Liu, Wenbiao

    Thinking of Hawking radiation calculation from a Schwarzschild black hole using Damour-Ruffini method, some key requirements of the tortoise coordinate transformation are pointed out. Extending these requirements to a dynamical black hole, a dynamical tortoise coordinate transformation is proposed. Under this new dynamical tortoise coordinate transformation, Hawking radiation from a Vaidya black hole can be got successfully using Damour-Ruffini method. Moreover, we also find that the radiation should be regarded as originating from the apparent horizon rather than the event horizon at least from the viewpoint of the first law of thermodynamics.

  16. Apparent Places with an Ellipsoidal Geometry of Refraction in the Earth's Atmosphere

    CERN Document Server

    Mathar, Richard J

    2009-01-01

    The displacement of star images by atmospheric refraction observed by an Earth-bound telescope is dominated by a familiar term proportional to the tangent of the zenith angle and proportional to the refractivity at the ground. The manuscript focuses on the torsion of the ray path through the atmosphere in a model of ellipsoidal atmospheric layers above the Earth surface, induced by the two slightly different principal curvatures along N-S and E-W pointing directions, depending on the geodetic latitude of the telescope site. This symmetry breaking effects apparent places in the sub-milliarcsecond range at optical and infrared wavelengths.

  17. Hawking-like radiation from the apparent horizon in an FRW Universe : Quantum Corrections

    CERN Document Server

    Biswas, Ritabrata; Chakraborty, Subenoy

    2011-01-01

    In this paper we study Hawking-like radiation in a FRW-Universe using semi-classical tunnelling approach and the Hamilton-Jacobi method. Radial null geodesics are used to picture the process as a "tunnelling" of particles from behind the apparent horizon and Hawking -like temperature has been calculated. Quantum corrections have been evaluated in the Hamilton-Jacobi Method by solving Klein-Gordan wave equation and the temperature agrees at the semiclassical level. Also it is found that Hamilton-Jacobi formalism does not depend on the choice of the coordinate system. Finally, leading order corrections to entropy has been calculated.

  18. Hawking-like radiation from the apparent horizon in an FRW Universe : Quantum Corrections

    OpenAIRE

    Biswas, Ritabrata; Mazumder, Nairwita; Chakraborty, Subenoy

    2011-01-01

    In this paper we study Hawking-like radiation in a FRW-Universe using semi-classical tunnelling approach and the Hamilton-Jacobi method. Radial null geodesics are used to picture the process as a "tunnelling" of particles from behind the apparent horizon and Hawking -like temperature has been calculated. Quantum corrections have been evaluated in the Hamilton-Jacobi Method by solving Klein-Gordan wave equation and the temperature agrees at the semiclassical level. Also it is found that Hamilt...

  19. Apparent change of Rhesus blood group typing in a case of ulcerative colitis.

    Science.gov (United States)

    Tien, S L; Ong, Y W; Ng, H S

    1991-08-01

    An interesting case of ulcerative colitis with an apparent change of Rhesus blood group typing is described. To our knowledge, this has not been reported before. We postulate that during the initial active phase of ulcerative colitis, an unknown D-like antigen, possibly bacterial in origin, could temporarily give rise to a Rhesus D-positive blood group typing in a patient with Rhesus D-negative blood type. Interestingly, with continuous immunosuppressive therapy for ulcerative colitis, the patient did not develop anti-D antibodies despite multiple transfusions with D-positive blood. PMID:1776013

  20. Biosynthesis of Xanthan Gum from Fermenting Shrimp Shell: Yield and Apparent Viscosity

    OpenAIRE

    Larissa Alves de Sousa Costa; Márcio Inomata Campos; Janice Izabel Druzian; Ana Maria Oliveira; Enio Nazaré de Oliveira Junior

    2014-01-01

    With the aim of producing xanthan gum, the effects of an aqueous shrimp shell extract (SSAE) as the source of carbon and nitrogen on the yield and apparent viscosity of the gums produced by fermentation using three native strains of Xanthomonas campestris were studied. It was found that the SSAE contained 89.75% moisture, 0.054% ash, 8.069% protein, 0.787 lipids, and 1.337% carbohydrates. Media containing different concentrations of SSAE and supplemented with urea (0.01%) and phosphate (0.1%)...

  1. Apparent viscosity by irradiation dose-effect relationship for starch-based materials

    International Nuclear Information System (INIS)

    There are analysed and presented, in terms of dose-effect relationship, the experimental results on the investigation of the rheological behaviour of gelatinized suspensions of irradiated starch and starch-based materials, as well as the variation with the dose value of the apparent viscosity and the shear stress. Irradiation has been performed using a linear accelerator, with the following parameters: electron mean energy, ∼6 MeV; mean bean current, 10 μA ; pulse period, 3.5 μs and repetition rate, 100 Hz. The main experimental parameters were: irradiation dose in the range of 0-25 kGy; dose rate 1.5-2.0 kGy/min and dose uniformity less than 10 %. Doses were checked by standard procedures for electron beam dosimetry. Some starch-based materials were ground and sieved to obtain similar particle sizes, necessary to eliminate the influence of particle size on the apparent viscosity variation with the dose. The rheoviscometric measurements have been carried out using a rotationally viscometer on gelatinised suspensions of starch-based materials, into equivalent starch concentration and alkalinised suspensions for pepper. For the considered materials the variation of apparent viscosity by irradiation dose is described by exponential equations and the apparent viscosity decreases with the dose. These equations fit very well the experimental data for starch and starch-based materials, the correlation coefficient values being, r ≥ 0.93 for all cases of dose-effect relationships for starch suspensions. The coefficients of these equations could also be obtained by analyzing the data from viscometric measurements and they strongly depend on the shear rate values, Dr. The starches and starch-based materials obviously present the same rheological behaviour under irradiation and this fact should be attributed to starch degradation and depolymerization due to the ionising radiation action and confirms one of this study main assumption. This property should be used to

  2. Upper extremity deep vein thrombosis in a 25 years old apparently healthy man

    Directory of Open Access Journals (Sweden)

    Fitsum Habte

    2010-01-01

    Full Text Available This case of upper extremity deep vein thrombosis is selected for case report as it is a rare form of deep vein thrombosis without a very well established treatment modality and prognosis. The objective of this study was to report the outcome of a 25 years old male patient with idiopathic upper extremity deep vein thrombosis treated conservatively with low molecular weight heparin (LMWH and oral warfarin. The data sources used were patient interview, laboratory and radiology investigation results and patient charts. The patient had no apparent recurrence or complication for 3 years except the presence of occasional dull pain over the affected left upper extremity

  3. Hysteresis contributions to the apparent gate pulse refreshing of carbon nanotube based sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ervin, Matthew H; Dorsey, Andrew M; Salaets, Natalie M, E-mail: MErvin@ARL.Army.mi [US Army Research Laboratory, AMSRD-ARL-SE-RL, 2800 Powder Mill Road, Adelphi, MD 20783-1197 (United States)

    2009-08-26

    We have fabricated back-gated carbon nanotube (CNT) field effect transistors (FET) and used them to sense NH{sub 3} (ammonia) gas. After observing the long time required for the sensor to recover after being exposed to NH{sub 3}, we attempted to accelerate the sensor recovery by pulsing the gate electrode for a period of time at an appropriate bias. We have found that most, if not all, of the apparent sensor refreshing due to the gate pulse is actually a measurement artifact resulting from device hysteresis.

  4. Dynamic aspects of apparent attenuation and wave localization in layered media

    Science.gov (United States)

    Haney, M.M.; Van Wijk, K.

    2008-01-01

    We present a theory for multiply-scattered waves in layered media which takes into account wave interference. The inclusion of interference in the theory leads to a new description of the phenomenon of wave localization and its impact on the apparent attenuation of seismic waves. We use the theory to estimate the localization length at a CO2 sequestration site in New Mexico at sonic frequencies (2 kHz) by performing numerical simulations with a model taken from well logs. Near this frequency, we find a localization length of roughly 180 m, leading to a localization-induced quality factor Q of 360.

  5. Apparent beam size definition of focused ion beams based on scanning electron microscopy images of nanodots

    OpenAIRE

    Vladov, Nikola; Segal, Joel; Ratchev, Svetan

    2015-01-01

    In this paper the new term apparent beam size of Focused Ion Beam (FIB) is introduced and an original method of its evaluation is demonstrated. Traditional methods of measuring the beam size, like the knife edge method, provide information about the quality of the beam itself but practically they do not give information on the FIB sputtering resolution. To do this, it is necessary to take into account the material dependant interaction of the beam with the specimen and the gas precursor in th...

  6. Ventricular Arrhythmias in Apparently Normal Hearts: Who Needs an Implantable Cardiac Defibrillator?

    Science.gov (United States)

    Tan, Alex Y; Ellenbogen, Kenneth

    2016-09-01

    Idiopathic ventricular tachycardia is often considered a benign form of ventricular arrhythmia in patients without apparent structural heart disease. However, a subset of patients may develop malignant ventricular arrhythmias and present with syncope and sudden cardiac arrest. Survivors of cardiac arrest are candidates for implantable cardiac defibrillators (ICDs). The indications for ICDs in patients with less than a full-blown cardiac arrest presentation but with electrocardiographically high-risk ectopy features remain uncertain. This article addresses some of the uncertainties and pitfalls in ICD risk stratification in this patient group and explores potential mechanisms for malignant conversion of benign premature ventricular complexes to sustained arrhythmia. PMID:27521094

  7. Entropy spectrum of the apparent horizon of Vaidya black holes via adiabatic invariance

    Science.gov (United States)

    Chen, Ge-Rui; Huang, Yong-Chang

    2016-01-01

    The spectroscopy of the apparent horizon of Vaidya black holes is investigated via adiabatic invariance. We obtain an equally spaced entropy spectrum with its quantum equal to the one given by Bekenstein [J. D. Bekenstein, Phys. Rev. D 7, 2333 (1973)]. We demonstrate that the quantization of entropy and area is a generic property of horizon, not only for stationary black holes, and the results also exit in a dynamical black hole. Our work also shows that the quantization of black hole is closely related to the tunneling formalism for deriving the Hawking effect, which is interesting.

  8. Decline of Pulmonary Function Is Associated With the Presence of Rheumatoid Factor in Korean Health Screening Subjects Without Clinically Apparent Lung Disease: A Cross-Sectional Study.

    Science.gov (United States)

    Hwang, Jiwon; Song, Jae-Uk; Ahn, Joong Kyong

    2016-05-01

    Although higher-than-normal levels of rheumatoid factor (RF) are often observed in subjects without specific medical problems, little is known about the influence of RF on pulmonary function in health screening subjects. This study aimed to determine the association between the presence of RF and decreased pulmonary function in Korean health screening subjects without any history of joint disease or clinically apparent lung disease.A total of 115,641 study subjects (age range, 18-88 years) participated in the health checkup program. We excluded subjects who did not have pulmonary function test, as well as those with abnormal chest radiographs. Subjects with medical history of arthritis including rheumatoid arthritis, and lung disease based on the self-reported questionnaire. Final analysis was performed on 94,438 Koreans (41,261 women).RF-positive subjects had a lower forced vital capacity (FVC) predicted value and forced expiratory volume in 1 s (FEV1) predicted value than RF-negative subjects (82.8 ± 11.5% vs 83.8 ± 11.4% for FVC% predicted and 83.5 ± 13.0% vs 85.1 ± 12.9% for FEV1% predicted, P pulmonary function in apparently healthy subjects. A follow-up study to investigate serial changes in pulmonary function may reveal the actual influence of raised RF titers. PMID:27175698

  9. The origin of a large apparent tortuosity factor for the Knudsen diffusion inside monoliths of a samaria-alumina aerogel catalyst: a diffusion NMR study.

    Science.gov (United States)

    Mueller, R; Zhang, S; Klink, M; Bäumer, M; Vasenkov, S

    2015-11-01

    Pulsed field gradient (PFG) NMR was applied to measure tortuosity factors for carbon dioxide diffusion in the Knudsen and gas regimes inside monoliths of a samaria-alumina aerogel catalyst, a high porosity material containing micropores in addition to meso- and macropores. The apparent tortuosity factor obtained from PFG NMR measurements for the Knudsen diffusion in the meso- and macropores of the catalyst has an unexpectedly large value of approximately 6 if carbon dioxide adsorption in the micropores and other types of surface adsorption sites of the catalyst is ignored. At the same time, the corresponding apparent tortuosity factor in the gas regime was found to be around 2. Application of a proposed model which describes fast molecular exchange between the surface adsorption sites and the main pore volume of the catalyst yields corrected tortuosity factors which depend only on the pore system geometry. Using this model, the corrected tortuosity factors were found to be around 2 for both diffusion regimes, in agreement with the expectations based on a high porosity of the studied catalyst. PMID:26426141

  10. Volumetric properties of binary mixtures of ionic liquid 1-butyl-3-methylimidazolium octylsulfate with water or propanol in the temperature range of 278.15K to 328.15K

    International Nuclear Information System (INIS)

    Densities of 1-butyl-3-methylimidazolium octylsulfate ([bmim][OcOSO3]) solutions in water and 1-propanol have been measured with an oscillating-tube densimeter at temperatures from 278.15K to 328.15K. From these densities, apparent molar volumes Vφ of [bmim][OcOSO3] in both solvents have been calculated, and its dependence on the molality has been treated with the Redlich and Meyer equation. Debye-Huckel limiting slopes for 1-propanol at working temperatures have been calculated, and apparent molar volumes of [bmim][OcOSO3] at infinite dilution Vφo in both solvents have been evaluated. The partial molar volume at infinite dilution of [bmim][OcOSO3] in water is higher than in 1-propanol and augments when the temperature augments. On the other hand, the partial molar volume at infinite dilution of [bmim][OcOSO3] in 1-propanol decreases when the temperature augments

  11. STUDIES OF ULTRASONIC AND VISCOMETRIC BEHAVIOR OF AZITHROMYCIN WITH DIFFERENT SOLVENT SYSTEMS DIOXANE-WATER AND METHANOL-WATER MIXTURE AT 305.15 K

    Directory of Open Access Journals (Sweden)

    S.A.Quazi

    2015-01-01

    Full Text Available Antibiotic drug Azithromycin is mainly used for treatments of infectious disease caused by bacteria such as respiratory,skin,ear and sexually transmitted diseases such great importance of azithromycine in human life the densities, ultrasonic velocities and viscosities of azithromycine have been evaluated in different concentrations in 70% dioxane-water and 70% methanol-water mixtures at 305.15 K. Experimental data of sound velocities and densities of solutions in 70% dioxane-water helps to determine the various acoustical parameters such as adiabatic compressibility, apparent molal volumes, intermolecular free length, specific acoustic impedance, relative association etc. for evaluating the molecular interactions present in different solutions were studied.

  12. INCIDENCE OF SUB - CLINICAL AIRFLOW OBSTRUCTION IN APPARENTLY HEALTHY MEDICAL PERSONNEL; DIAGNOSIS AND COMPARISION BY SPIROMETRY AND PEAK FLOW METRY

    OpenAIRE

    Subba Rao; Aruna; Sateesh Kumar; Neethi Chandra

    2015-01-01

    AIM & OBJE CTIVES OF THE STUDY: To diagnose sub - clinical airflow obstruction in apparently healthy medical personnel, and to compare Peak Expiratory Flow Rate (PEFR) by using Spirometry and by Wright’s peak flow meter. METHODOLOGY: About 80 apparently healthy medical students including Post Graduates, internees and medical technicians were taken in ...

  13. A geometry-preserving finite volume method for conservation laws on curved geometries

    OpenAIRE

    Beljadid, Abdelaziz; LeFloch, Philippe G.; Mohammadian, Abdolmajid

    2013-01-01

    We consider nonlinear hyperbolic equations posed on curved geometries and investigate a geometry-preserving, second-order accurate, finite volume method. For definiteness, we study the so-called class of ''geometric Burgers equations'' posed on the sphere and defined from a prescribed potential function. Despite its apparent simplicity, this model exhibits very complex wave phenomena that are not observed in absence of geometrical effects. Our method is based on second-order finite volume app...

  14. Apparent digestibility of nutrients, energy, and amino acid of nontoxic and detoxified physic nut cakes for Nile tilapia

    Directory of Open Access Journals (Sweden)

    Hamilton Hisano

    2015-09-01

    Full Text Available Abstract:The objective of this work was to evaluate the apparent digestibility coefficients of nutrients, energy, and amino acids of nontoxic and detoxified physic nut cakes treated with solvent plus posterior extrusion, for Nile tilapia. The apparent digestibility coefficients of crude protein and gross energy were higher for detoxified than for nontoxic physic nut cake. However, the apparent digestibility coefficient of ether extract of the nontoxic physic nut cake was higher than that of the detoxified one. The apparent digestibility coefficient of amino acids of both feed ingredients was superior to 80%, except for glycine, for the nontoxic psychic nut cake, and for threonine, for the detoxified one. Nontoxic and detoxified physic nut cakes show apparent digestibility coefficient values equivalent to those of the other evaluated oilseeds and potential for inclusion in Nile tilapia diets.

  15. Chewing sandpaper: grit, plant apparency, and plant defense in sand-entrapping plants.

    Science.gov (United States)

    LoPresti, Eric F; Karban, Richard

    2016-04-01

    Sand entrapment on plant surfaces, termed psammophory or sand armor, is a phylogenetically and geographically widespread trait. The functional significance of this phenomenon has been poorly investigated. Sand and soil are nonnutritive and difficult for herbivores to process, as well as visually identical to the background. We experimentally investigated whether this sand coating physically protected the plant from herbivores or increased crypsis (e.g., decreased apparency to herbivores). We tested the former hypothesis by removing entrapped sand from stems, petioles, and leaves of the sand verbena Abronia latifolia and by supplementing natural sand levels in the honeyscented pincushion plant Navarretia mellita. Consistent with a physical defensive function, leaves with sand present or supplemented suffered less chewing herbivory than those with sand removed or left as is. To test a possible crypsis effect, we coated some sand verbena stems with green sand, matching the stem color, as well as others with brown sand to match the background color. Both suffered less chewing herbivory than controls with no sand and herbivory did not significantly differ between the colors, suggesting crypsis was not the driving resistance mechanism. Strong tests of plant apparency are rare; this experimental approach may be possible in other systems and represents one of few manipulative tests of this long-standing hypothesis. PMID:27220199

  16. Apparent [O III] variability in the narrow line Seyfert I Mrk142

    Science.gov (United States)

    Zhang, Xue-Guang; Feng, Long-Long

    2016-03-01

    In this Letter, we checked spectral properties of the well-known narrow line Seyfert I Mrk142, in order to try to find effects of narrow line variability on BLR radius of Mrk142 which is an outlier in the R-L plane. Although, no improvement can be found on BLR radius, apparent narrow line variability can be confirmed in Mrk142. Using the public spectra collected from the Lick AGN Monitoring Project, the spectral scaling method based on assumption of constant [O III] line is first checked by examining broad and narrow emission line properties. We find that with the application of the spectral scaling method, there is a strong correlation between the [O III] line flux and the [O III] line width, but weaker correlations between the broad Hα flux and the broad Hβ flux, and between the broad Hα flux and the continuum emission at 5100 Å. The results indicate that the assumption of constant [O III] line is not preferred, and caution should be exercised when applying the spectral scaling calibration method. And then, we can find a strong correlation between the [O III] line flux and the continuum emission at 5100 Å, which indicates apparent short-term variability of the [O III] line in Mrk142 over about two months.

  17. Intake and total apparent digestibility in lambs fed six maize varieties in the Brazilian Semiarid

    Directory of Open Access Journals (Sweden)

    Rafael Dantas dos Santos

    2011-12-01

    Full Text Available The objective of this study was to evaluate the daily intake and total apparent digestibility of dry matter, organic matter, crude protein, gross energy, ether extract, neutral detergent fiber, acid detergent fiber, total and non-fibrous carbohydrates, total digestible nutrients, energy intake and nitrogen balance of silages of six maize varieties with early or super early cycles recommended to Northeast Brazil. Twenty-four male castrated lambs were lodged in metabolic cages. A completely randomized design with six treatments and four replications was used, with means compared by Tukey test at 5%. There were no differences among varieties for any of the evaluated variables regarding intake and apparent digestibility. Concerning the intake of digestible energy, metabolizable energy and the ratio content of digestible and metabolizable energy, significant differences were observed between varieties and BRS Assum Preto showed highest values of metabolizable energy (2.650,8 kcal/day. All of the treatments presented positive nitrogen balance and did not differ among themselves. The varieties asessed can be an additional option to the semiarid regions in Brazil.

  18. Interacting entropy-corrected holographic dark energy with apparent horizon IR-Cutoff and thermodynamical description

    CERN Document Server

    Khodam-Mohammadi, A

    2011-01-01

    The interacting entropy-corrected holographic dark energy (ECHDE), created by both logarithmic correction and power-law corrected of entropy, so-called "ECHDE" and "power-law ECHDE (PLECHDE)" respectively, with apparent horizon as an IR-Cutoff (AH-IR-Cutoff) are studied in a non-flat universe enclosed by apparent horizon. The ECHDE model with AH-IR-cutoff may be considered as a generalization of ordinary HDE, presented by Sheykhi [A. Sheykhi, Class. Quant. Grav., \\textbf{27}, 025007 (2010)]. We show that in both models, the phantom divide may be crossed in a model with or without interaction. Also the effect of interaction are studied in both models. it is found that in both models, for large horizon radius, the accelerated expanding universe can be driven only by interacting case. We also show that the coincidence problem can be solved in both models. The thermodynamical description of dark energy is studied only in ECHDE model. Based on the first law of thermodynamics for dark energy sector in the nonintera...

  19. Spherically symmetric systems of fields and black holes. I. Definition and properties of apparent horizon

    International Nuclear Information System (INIS)

    We investigate three model field theories: a minimally coupled charged scalar field together with gravity and electromagnetism, a minimally coupled SO(3) Yang-Mills field and gravity, and the Callan-Coleman-Jackiw scalar field. We restrict ourselves to spherically symmetric configurations; the corresponding dimensional reduction leads to an action functional on a two-dimensional spacetime which contains a metric, a neutral scalar, a charged scalar, and an electromagnetic field. The action is written in the second-order, covariant and gauge-invariant form. We generalize the definition of the future and past apparent horizon so that it will not be visible from the future and past null infinity, respectively, and will form a nontimelike surface, both also in the case of the Callan-Coleman-Jackiw model. We prove an inequality relating the surface area and the charges of the apparent horizon. We study the boundary conditions for the fields at the horizon, at the regular center, and at infinity. Finally, we speculate on the existence of static spherically symmetric solutions, where a black hole is surrounded by a matter shell; in two-dimensional spacetime, this looks like a kink

  20. Impact of Apparent Reactance Injected by TCSR on Distance Relay in Presence Phase to Earth Fault

    Directory of Open Access Journals (Sweden)

    Mohamed Zellagui

    2013-01-01

    Full Text Available This research paper presents the impact study of apparent reactance injected by series Flexible AC Transmission System (FACTS i.e. Thyristor Controlled Series Reactor (TCSR on the measured impedance of a 400 kV single electrical transmission line in the presence of phase to earth fault with fault resistance. The study deals with an electrical transmission line of Eastern Algerian transmission networks at Group Sonelgaz (Algerian Company of Electrical compensated by TCSR connected at midpoint of the transmission line. This compensator used to inject voltage and reactive power is controlled by TCSR. The simulations results investigate the three impacts of the apparent reactance injected by TCSR (XTCSR on transmission line protected by distance relay protection. The impacts concern the active and reactive power, the line impedance (reactance and resistance, and the short circuit parameters (symmetrical currents, line currents, symmetrical voltages and line voltages as well as the measured impedance by relay (resistance and reactance in the presence of earth fault These impacts are investigated in order to improve the performances of distance relay protection. More the impact of XTCSR by three TCSR for cases studies is presented.

  1. Assessment of the apparent activation energies for gas/solid reactions-carbonate decomposition

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The guidelines for assessing the apparent activation energies of gas/solid reactions have been proposed based on the ex-perimental results from literatures. In CO2 free inlet gas flow, CaCO3 decomposition between 950 and 1250 K with thin sample layercould be controlled by the interfacial chemical reaction with apparent activation energy E = (215+10) kJ/mol and E = (200±10)kJ/mol at T = 813 to 1020 K, respectively. With relatively thick sample layer between 793 and 1273 K, the CaCO3 decompositioncould be controlled by one or more steps involving self-cooling, nucleation, intrinsic diffusion and heat transfer of gases, and E couldvary between 147 andl90 kJ/mol. In CO2 containing inlet gas flow (5%-100% of CO2), E was determined to be varied from 949 to2897 kJ/mol. For SrCO3 and BaCO3 decompositions controlled by the interfacial chemical reaction, E was (213+15) kJ/mol (1000-1350 K) and (305+15) kJ/mol (1260-1400 K), respectively.

  2. Why does the apparent mass of a coronal mass ejection increase?

    CERN Document Server

    Feng, Li; Shen, Fang; Shen, Chenglong; Inhester, Bernd; Lu, Lei; Gan, Weiqun

    2015-01-01

    Mass is one of the most fundamental parameters characterizing the dynamics of a coronal mass ejection (CME). It has been found that CME apparent mass measured from the brightness enhancement in coronagraph images shows an increasing trend during its evolution in the corona. However, the physics behind it is not clear. Does the apparent mass gain come from the mass outflow from the dimming regions in the low corona, or from the pileup of the solar wind plasma around the CME when it propagates outwards from the Sun? We analyzed the mass evolution of six CME events. Their mass can increase by a factor of 1.6 to 3.2 from 4 to 15 Rs in the field of view (FOV) of the coronagraph on board the Solar Terrestrial Relations Observatory (STEREO). Over the distance about 7 to 15 Rs, where the coronagraph occulting effect can be negligible, the mass can increase by a factor of 1.3 to 1.7. We adopted the `snow-plough' model to calculate the mass contribution of the piled-up solar wind in the height range from about 7 to 15 ...

  3. Cardiovascular Response to Manual Acupuncture Needle Stimulation among Apparently Healthy Nigerian Adults.

    Science.gov (United States)

    Sokunbi, Ganiyu; Maduagwu, Stanley; Jaiyeola, Olabode; Gambo, Hassan; Blasu, Cephas

    2016-06-01

    This study investigated experience with acupuncture needle stimulation of apparently healthy adult Nigerians and the responses of the systolic blood pressure (SBP), diastolic blood pressure, heart rate (HR), and rate pressure products (RPP) to acupuncture at both real acupuncture points relevant to the treatment of cardiovascular disorder and sham acupuncture points not relevant to the treatment of cardiovascular disorder. Seventy-eight participants were randomly placed into three groups: the real acupuncture group (RAG); the sham acupuncture group (SAG); and the control group, with 26 participants per group. Data were collected preintervention, 15 minutes into acupuncture stimulation, postintervention, and 15 minutes after intervention. Changes (postintervention - preintervention scores) in the SBP, HR, and RPP were statistically lower in the RAG than in the SAG. Changes in the DBP showed a significant difference between the SAG and the RAG (p > 0.05). Findings from this study showed that among apparently healthy Nigerian adults, acupuncture needle stimulation at acupoints relevant to cardiovascular disorders was more effective than sham intervention in reducing the SBP, HR, and RPP. Participants reported heaviness, numbness, and increasing pain, but no dizziness, fainting and/or life-threatening side effects, during and after the acupuncture needle stimulation. PMID:27342888

  4. Predicting apparent slip at liquid-liquid interfaces without an interface slip condition

    Science.gov (United States)

    Poesio, Pietro; Damone, Angelo; Matar, Omar

    2015-11-01

    We show that if we include a density-dependent viscosity into the Navier-Stokes equations then we can describe, naturally, the velocity profile in the interfacial region, as we transition from one fluid to another. This requires knowledge of the density distribution (for instance, via Molecular Dynamics [MD] simulations, a diffuse-interface approach, or Density Functional Theory) everywhere in the fluids, even at liquid-liquid interfaces where regions of rapid density variations are possible due to molecular interactions. We therefore do not need an artificial interface condition that describes the apparent velocity slip. If the results are compared with the computations obtained from MD simulations, we find an almost perfect agreement. The main contribution of this work is to provide a simple way to account for the apparent slip at liquid-liquid interfaces without relying upon an additional boundary condition, which needs to be calculated separately using MD simulations. Examples are provided involving two immiscible fluids of varying average density ratios, undergoing simple Couette and Poisseuille flows. MIUR through PRIN2012-NANOBridge; Royal Society International Exchange Scheme (IE141486).

  5. Effect of N Fertilization on Grain Yield of Winter Wheat and Apparent N Losses

    Institute of Scientific and Technical Information of China (English)

    CUI Zhen-Ling; CHEN Xin-Ping; LI Jun-Liang; XU Jiu-Fei; SHI Li-Wei; ZHANG Fu-Suo

    2006-01-01

    Excessive nitrogen (N) fertilizer application to winter wheat is a common problem on the North China Plain. To determine the optimum fertilizer N rate for winter wheat production while minimizing N losses, field experiments were conducted for two growing seasons at eight sites, in Huimin County, Shandong Province, from 2001 to 2003. The optimum N rate for maximum grain yield was inversely related to the initial soil mineral N content (Nmin) in the top 90 cm of the soil profile before sowing. There was no yield response to the applied N at the three sites with high initial soil mineral N levels (average 212 kg N ha-1). The average optimum N rate was 96 kg N ha-1 for the five sites with low initial soil Nmin (average 155 kg N ha-1) before sowing. Residual nitrate N in the top 90 cm of the soil profile after harvest increased with increasing fertilizer N application rate. The apparent N losses during the wheat-growing season also increased with increasing N application rate. The average apparent N losses with the optimum N rates were less than 15 kg N ha-1,whereas the farmers' conventional N application rate resulted in losses of more than 100 kg N ha-1. Therefore, optimizing N use for winter wheat considerably reduced N losses to the environment without compromising crop yields.

  6. Apparent temperature anisotropies due to wave activity in the solar wind

    Directory of Open Access Journals (Sweden)

    E. Marsch

    2011-05-01

    Full Text Available The fast solar wind is a collisionless plasma permeated by plasma waves on many different scales. A plasma wave represents the natural interplay between the periodic changes of the electromagnetic field and the associated coherent motions of the plasma particles. In this paper, a model velocity distribution function is derived for a plasma in a single, coherent, large-amplitude wave. This model allows one to study the kinetic effects of wave motions on particle distributions. They are by in-situ spacecraft measured by counting, over a certain sampling time, the particles coming from various directions and having different energies. We compare our results with the measurements by the Helios spacecraft, and thus find that by assuming high wave activity we are able to explain key observed features of the measured distributions within the framework of our model. We also address the recent discussions on nonresonant wave–particle interactions and apparent heating. The applied time-averaging procedure leads to an apparent ion temperature anisotropy which is connected but not identical to the intrinsic temperature of the underlying distribution function.

  7. Apparent diffusion coefficient parametric response mapping MRI for follow-up of glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ra Gyoung [Catholic Kwandong University International St. Mary' s Hospital, Catholic Kwandong University College of Medicine, Department of Radiology, Seo-gu, Incheon (Korea, Republic of); Kim, Ho Sung; Hong, Gil Sun; Kim, Sang Joon [Asan Medical Center, University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Songpa-Gu, Seoul (Korea, Republic of); Kim, Dae Yoon [Bundang Jesaeng Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of)

    2016-04-15

    To determine the diagnostic superiority of parametric response mapping of apparent diffusion coefficient (ADCPR) for predicting glioblastoma treatment response, compared to single time point measurement. Fifty post-treatment glioblastoma patients were enrolled. ADCPR was calculated from serial apparent diffusion coefficient (ADC) maps acquired before and at the time of first detection of an enlarged contrast-enhancing lesion on voxel-by-voxel basis. The percentage-decrease in ADCPR and tenth percentile histogram cutoff value of ADC (ADC10) were compared at subsequent 3-month and 1-year follow-ups. The percentage-decrease in ADCPR was significantly higher in the progression group (mean = 33.2-38.3 %) than in the stable-response group (mean = 9.7 %) at 3 months follow-up (corrected p < 0.001 for both readers). ADCPR significantly improved area under the receiver operating characteristic curve from 0.67 to 0.88 (corrected p = 0.037) and from 0.70 to 0.92 (corrected p = 0.020) for both readers, respectively, compared to ADC10 at 3-month follow-up, but did not significantly improve at 1-year follow-up. The inter-reader agreement was higher for ADCPR than ADC10 (intraclass correlation coefficient, 0.93 versus 0.86). Voxel-based ADCPR appears to be a superior imaging biomarker than ADC, particularly for predicting early tumour progression in patients with glioblastoma. (orig.)

  8. Global oscillations of the Sun: observed as oscillations in the apparent solar limb darkening function

    International Nuclear Information System (INIS)

    Analysis of the 1973 solar oblateness observations made at SCLERA has indicated that most of the oscillatory power found in observations of the apparent solar diameter is statistically significant and that it is produced by fluctuations in the limb darkening function rather than by a simple displacement of the solar limb. The differential refractive effects in the Earth's atmosphere may be ruled out as operative mechanisms for generating the observed oscillations. Solar and non-solar mechanisms for producing changes in the apparent limb darkening function are considered as possible sources of the observed oscillatory effects; it is concluded that acoustic and gravity modes of oscillation are the only viable mechanisms capable of producing these phenomena. This interpretation necessitates the imposition of certain constraints on modelling of the solar interior and on solar pulsation theory. The conclusion that the oscillations are detected through changes in the limb darkening function leads to a new constraint on the photospheric boundary conditions used in pulsation theory. The identification of two of the oscillations as being high-order gravity modes also necessitates the formulation of a new constraint on the Brunt-Vaisalai frequency in the solar interior and, in addition, may place a constraint depth on the convection zone. Application of the constraint on the Brunt-Vaisalai frequency permits discrimination between current models while the first constraint, if correct, may further complicate studies of the outer envelope of the Sun. (author)

  9. Apparent diffusion coefficient parametric response mapping MRI for follow-up of glioblastoma

    International Nuclear Information System (INIS)

    To determine the diagnostic superiority of parametric response mapping of apparent diffusion coefficient (ADCPR) for predicting glioblastoma treatment response, compared to single time point measurement. Fifty post-treatment glioblastoma patients were enrolled. ADCPR was calculated from serial apparent diffusion coefficient (ADC) maps acquired before and at the time of first detection of an enlarged contrast-enhancing lesion on voxel-by-voxel basis. The percentage-decrease in ADCPR and tenth percentile histogram cutoff value of ADC (ADC10) were compared at subsequent 3-month and 1-year follow-ups. The percentage-decrease in ADCPR was significantly higher in the progression group (mean = 33.2-38.3 %) than in the stable-response group (mean = 9.7 %) at 3 months follow-up (corrected p < 0.001 for both readers). ADCPR significantly improved area under the receiver operating characteristic curve from 0.67 to 0.88 (corrected p = 0.037) and from 0.70 to 0.92 (corrected p = 0.020) for both readers, respectively, compared to ADC10 at 3-month follow-up, but did not significantly improve at 1-year follow-up. The inter-reader agreement was higher for ADCPR than ADC10 (intraclass correlation coefficient, 0.93 versus 0.86). Voxel-based ADCPR appears to be a superior imaging biomarker than ADC, particularly for predicting early tumour progression in patients with glioblastoma. (orig.)

  10. LUNG DIFFUSION CAPACITY CAN PREDICT MAXIMAL EXERCISE IN APPARENTLY HEALTHY HEAVY SMOKERS

    Directory of Open Access Journals (Sweden)

    Alfredo Chetta

    2008-06-01

    Full Text Available Chronic exposure to tobacco smoking may damage lung and heart function. The aim of this study was to assess maximal exercise capacity and its relationship with lung function in apparently healthy smokers. We recruited 15 heavy smokers (age 47 years ± 7, BMI 25 kg/m2 ± 3, pack/years 32 ± 9 without any cardiovascular or pulmonary signs and symptoms. Fifteen healthy non smoking subjects were enrolled as a control group. All subjects underwent pulmonary function tests, electrocardiograms at rest and graded cycle exercise tests. In smokers and controls, resting lung and cardiac function parameters were in the normal range, apart from diffusing lung capacity (TLCO values which were significantly lower in smokers (p < 0.05. As compared to controls, smokers presented lower maximal exercise capacity with lower values at peak of exercise of oxygen uptake (peak VO2, workload, oxygen uptake/watt ratio and oxygen pulse (p < 0.05 and higher dyspnoea perception (p < 0.05. Moreover, peak VO2, maximal workload and oxygen pulse at peak exercise were related to and predicted by TLCO (p < 0. 05. Our study confirms that maximal exercise capacity is reduced in apparently healthy heavy smokers, and shows that TLCO explains some of the variance in maximal exercise

  11. A novel RET gene mutation in a patient with apparently sporadic pheochromocytoma.

    Science.gov (United States)

    Scollo, Claudia; Russo, Marco; De Gregorio, Laura; Terranova, Rosa; Mangione, Erika; Castoro, Carlotta; Squatrito, Sebastiano; Pellegriti, Gabriella

    2016-01-01

    Pheochromocytoma (Pheo) is a chromaffin tumor arising from the adrenal medulla. The recent discovery of new germline mutations in RET, SDHA, SDHB, SDHC, SDHD, VHL, NF1, TMEM127, MAX genes, increased the rate of genetic disease from 10% to 28% in patients with apparently sporadic tumor. RET germline mutations cause multiple endocrine neoplasia type 2 syndrome (MEN 2A) characterized by complete penetrance of medullary thyroid cancer (MTC), and lower prevalence of Pheo and hyperparathyroidism. We describe the genetic etiology of an apparently sporadic case of monolateral Pheo in a 42-year-old male patient. A new (not previously reported) MEN 2A-associated germline RET mutation located in exon 11 (Glu632Gly, caused by an A>G point mutation at position 1895 of the RET cDNA) was found in the patient but not in his living first-degree relatives. This observation increases the number of possible germline RET mutations. Genotype-phenotype correlation of this new genetic alteration is unknown, but this rare mutation is probably associated with a low risk for MTC (usually the first tumor diagnosed in MEN 2A syndrome) and with the development of Pheo before the onset of MTC. Since we expect MTC to occur in our patient, strict follow-up is mandatory. Our findings emphasize the relevance of genetic testing in patients with Pheo, especially when the clinical presentation (family history, young age at diagnosis, multiple locations, malignant lesions, and bilateralism) is suggestive. PMID:26497911

  12. Effect of organometallic clamp properties on the apparent diversity of tensile response of nanowires

    International Nuclear Information System (INIS)

    The influence of the experimental boundary conditions used for tensile testing of individual nanowires on the measured apparent mechanical response is reported. Using a microelectromechanical platform designed for in situ tensile testing, in combination with digital image correlation of sequences of scanning electron microscope images, the mechanical behavior of single crystalline Si, Pd, and Ge2Sb2Te5 nanowires was measured during load–unload cycles. In situ testing enables direct determination of the nanowire strain. Comparison of the direct strain with common metrics for apparent strain that include any compliance or slipping of the clamping materials (electron-beam induced Pt-containing deposits) highlights several different artifacts that may be manifested. Calculation of the contact stiffness is thus enabled, providing guidelines for both proper strain measurement and selection of clamping materials and geometries that facilitate elucidation of intrinsic material response. Our results suggest that the limited ability to tailor the stiffness of electron-beam induced deposits results from the predominance of the organic matrix in controlling its mechanical properties owing to relatively low Pt content and sparse morphology. (paper)

  13. Pseudomagnitudes and differential surface brightness: Application to the apparent diameter of stars

    Science.gov (United States)

    Chelli, Alain; Duvert, Gilles; Bourgès, Laurent; Mella, Guillaume; Lafrasse, Sylvain; Bonneau, Daniel; Chesneau, Olivier

    2016-05-01

    The diameter of a star is a major observable that serves to test the validity of stellar structure theories. It is also a difficult observable that is mostly obtained with indirect methods since the stars are so remote. Today only ~600 apparent star diameters have been measured by direct methods: optical interferometry and lunar occultations. Accurate star diameters are now required in the new field of exoplanet studies, since they condition the planets' sizes in transit observations, and recent publications illustrate a visible renewal of interest in this topic. Our analysis is based on the modeling of the relationship between measured angular diameters and photometries. It makes use of two new reddening-free concepts: a distance indicator called pseudomagnitude, and a quasi-experimental observable that is independent of distance and specific to each star, called the differential surface brightness (DSB). The use of all the published measurements of apparent diameters that have been collected so far, and a careful modeling of the DSB allow us to estimate star diameters with a median statistical error of 1.1%, knowing their spectral type and, in the present case, the VJHKs photometries. We introduce two catalogs, the JMMC Measured Diameters Catalog (JMDC), containing measured star diameters, and the second version of the JMMC Stellar Diameter Catalog (JSDC), augmented to about 453 000 star diameters. Finally, we provide simple formulas and a table of coefficients to quickly estimate stellar angular diameters and associated errors from (V, Ks) magnitudes and spectral types.

  14. Hematologic and serum biochemical parameters of apparently healthy rescued formosan pangolins (Manis pentadactyla pentadactyla).

    Science.gov (United States)

    Chin, Shih-chien; Lien, Chen-yah; Chan, Yating; Chen, Chun-lin; Yang, Yi- ching; Yeh, Lih-seng

    2015-03-01

    Natural habitats of pangolins are rapidly deteriorating because of extensive farming, logging, and human construction activities. In addition, the illegal trading of pangolins substantially accelerated the decline of the pangolins' population in southeastern Asia. The maintenance of confiscated pangolins in rescue centers is currently a daunting task for veterinarians and conservation biologists. There is limited information in the literature about the reference values regarding the physiology of pangolins. The purpose of this study is to establish reliable hematologic and serum biochemical reference values for the Formosan pangolin (Manis pentadactyla pentadactyla). Blood samples were collected from 51 apparently healthy pangolins from a population of 117 rescued pangolins at the Taipei Zoo. Sex-related differences were observed in platelet count, alanine aminotransferase level, mean corpuscular hemoglobin concentration, and total protein level. Age-related differences were also noted; juveniles have significantly higher platelet counts and alkaline phosphatase levels than their adult counter parts. The hematologic and serum biochemical reference values for the Formosan pangolin presented in this study can be applied in the medical care of this important species during rescue attempts. It is the first systematic report of blood parameters of apparently healthy pangolins and provides a basis for future investigation of this species. The reference values reported in this study may also be applicable to other pangolin species in the genus Manis. PMID:25831578

  15. The determination of bulk (apparent) density of plant fibres by density method

    International Nuclear Information System (INIS)

    The absolute density of plant fibres excludes all pores and lumen and therefore is a measure of the solid matter of the fibres. On the other hand the bulk density, which is being discussed here, includes all the solid matter and the pores of the fibres. In this work, the apparent density of the fibre was measured by using the Archimedes principle, which involves the immersion of a known weight of fibre into a solvent of lower density than the fibre. Toluene with a density of about 860 kg/m3 was chosen as a solvent. A tuft of fibre was weighed and recorded as Wfa. The fibre was then immersed in toluene, which wetted the fibre, and made to rest on the weighing pan submerged in the solvent and the weight of the immersed fibre was recorded as Wfs. The apparent density was then calculated using the equation. All the measurements were taken at room temperature. The fibre samples were not oven dried prior to measurement. (Author)

  16. Automated high-temperature guarded-hot-plate apparatus for measuring apparent thermal conductivity

    International Nuclear Information System (INIS)

    An automated guarded-hot-plate apparatus was designed and built to meet the requirements of ASTM Standard Test Method C-177 for measuring the thermal conductance of thermal insulation. Apparent thermal conductivity was measured with this apparatus in the range from 40 to 100 mW/(m.K) at mean temperatures from 300 to 750 K, in environments of air and helium, at pressures ranging from atmospheric pressure to roughing-pump vacuum. The apparatus is controlled by a desk-top computer. A thermocouple device of novel design more accurately senses the average temperature over the surface of each heater plate. An improved algorithm for the control sequence leads to more-stable heater powers and specimen temperatures. Overall uncertainties of apparent thermal conductivities at atmospheric pressure are 2% at 300 K and 5% at 750 K when measuring conductivities in the range from 40 to 100 mW/(m.K). The apparatus will be valuable in development of new Standard Reference Materials of low conductivity and for higher-temperature ranges, and is being used in comparative interlaboratory measurement programs

  17. Volumes of chain links

    CERN Document Server

    Kaiser, James; Rollins, Clint

    2011-01-01

    Agol has conjectured that minimally twisted n-chain links are the smallest volume hyperbolic manifolds with n cusps, for n at most 10. In his thesis, Venzke mentions that these cannot be smallest volume for n at least 11, but does not provide a proof. In this paper, we give a proof of Venzke's statement. The proof for n at least 60 is completely rigorous. The proof for n between 11 and 59 uses a computer calculation, and can be made rigorous for manifolds of small enough complexity, using methods of Moser and Milley. Finally, we prove that the n-chain link with 2m or 2m+1 half-twists cannot be the minimal volume hyperbolic manifold with n cusps, provided n is at least 60 or |m| is at least 8, and we give computational data indicating this remains true for smaller n and |m|.

  18. Aperiodic Volume Optics

    Science.gov (United States)

    Gerke, Tim D.

    Presented in this thesis is an investigation into aperiodic volume optical devices. The three main topics of research and discussion are the aperiodic volume optical devices that we call computer-generated volume holograms (CGVH), defects within periodic 3D photonic crystals, and non-periodic, but ordered 3D quasicrystals. The first of these devices, CGVHs, are designed and investigated numerically and experimentally. We study the performance of multi-layered amplitude computer-generated volume holograms in terms of efficiency and angular/frequency selectivity. Simulation results show that such aperiodic devices can increase diffraction efficiency relative to periodic amplitude volume holograms while maintaining angular and wavelength selectivity. CGVHs are also designed as voxelated volumes using a new projection optimization algorithm. They are investigated using a volumetric diffraction simulation and a standard 3D beam propagation technique as well as experimentally. Both simulation and experiment verify that the structures function according to their design. These represent the first diffractive structures that have the capacity for generating arbitrary transmission and reflection wave fronts and that provide the ability for multiplexing arbitrary functionality given different illumination conditions. Also investigated and discussed in this thesis are 3D photonic crystals and quasicrystals. We demonstrate that these devices can be fabricated using a femtosecond laser direct writing system that is particularly appropriate for fabrication of such arbitrary 3D structures. We also show that these devices can provide 3D partial bandgaps which could become complete bandgaps if fabricated using high index materials or by coating lower index materials with high index metals. Our fabrication method is particularly suited to the fabrication of engineered defects within the periodic or quasi-periodic systems. We demonstrate the potential for fabricating defects within

  19. Volume holographic memory

    Directory of Open Access Journals (Sweden)

    Cornelia Denz

    2000-05-01

    Full Text Available Volume holography represents a promising alternative to existing storage technologies. Its parallel data storage leads to high capacities combined with short access times and high transfer rates. The design and realization of a compact volume holographic storage demonstrator is presented. The technique of phase-coded multiplexing implemented to superimpose many data pages in a single location enables to store up to 480 holograms per storage location without any moving parts. Results of analog and digital data storage are shown and real time optical image processing is demonstrated.

  20. Correlation between 3 T apparent diffusion coefficient values and grading of invasive breast carcinoma

    International Nuclear Information System (INIS)

    Highlights: • Apparent diffusion coefficient is a quantitative parameter which reflects molecular water movement. • Grading is an independent prognostic factor which correlates with other histopathological features. • Apparent diffusion coefficient values were significantly different between G1 and G3 classes. - Abstract: Purpose: The aim of this study was to evaluate whether the apparent diffusion coefficient (ADC) provided by 3.0 T (3 T) magnetic resonance diffusion-weighted imaging (DWI) varied according to the grading of invasive breast carcinoma. Materials and methods: A total of 92 patients with 96 invasive breast cancer lesions were enrolled; all had undergone 3 T magnetic resonance imaging (MRI) for local staging. All lesions were confirmed by histological analysis, and tumor grade was established according to the Nottingham Grading System (NGS). MRI included both dynamic contrast-enhanced and DWI sequences, and ADC value was calculated for each lesion. ADC values were compared with NGS classification using the Mann–Whitney U and the Kruskal–Wallis H tests. Grading was considered as a comprehensive prognostic factor, and Rho Spearman test was performed to determine correlation between grading and tumor size, hormonal receptor status, HER2 expression and Ki67 index. Pearson's Chi square test was carried out to compare grading with the other prognostic factors. Results: ADC values were significantly higher in G1 than in G3 tumors. No significant difference was observed when G1 and G3 were compared with G2. Tumor size, hormonal receptor status, HER2 expression and Ki67 index correlated significantly with grading but there was a significant difference only between G1 and G3 related to the ER and PR status, HER2 expression and Ki67 index. There was no statistically significant difference in lesion size between the two groups. Conclusion: ADC values obtained on 3 T DWI correlated with low-grade (G1) and high-grade (G3) invasive breast carcinoma. 3

  1. Correlation between 3 T apparent diffusion coefficient values and grading of invasive breast carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cipolla, Valentina, E-mail: valentina.cipolla@yahoo.it [Department of Radiological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy); Santucci, Domiziana; Guerrieri, Daniele; Drudi, Francesco Maria [Department of Radiological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy); Meggiorini, Maria Letizia [Department of Gynaecological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy); Felice, Carlo de [Department of Radiological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy)

    2014-12-15

    Highlights: • Apparent diffusion coefficient is a quantitative parameter which reflects molecular water movement. • Grading is an independent prognostic factor which correlates with other histopathological features. • Apparent diffusion coefficient values were significantly different between G1 and G3 classes. - Abstract: Purpose: The aim of this study was to evaluate whether the apparent diffusion coefficient (ADC) provided by 3.0 T (3 T) magnetic resonance diffusion-weighted imaging (DWI) varied according to the grading of invasive breast carcinoma. Materials and methods: A total of 92 patients with 96 invasive breast cancer lesions were enrolled; all had undergone 3 T magnetic resonance imaging (MRI) for local staging. All lesions were confirmed by histological analysis, and tumor grade was established according to the Nottingham Grading System (NGS). MRI included both dynamic contrast-enhanced and DWI sequences, and ADC value was calculated for each lesion. ADC values were compared with NGS classification using the Mann–Whitney U and the Kruskal–Wallis H tests. Grading was considered as a comprehensive prognostic factor, and Rho Spearman test was performed to determine correlation between grading and tumor size, hormonal receptor status, HER2 expression and Ki67 index. Pearson's Chi square test was carried out to compare grading with the other prognostic factors. Results: ADC values were significantly higher in G1 than in G3 tumors. No significant difference was observed when G1 and G3 were compared with G2. Tumor size, hormonal receptor status, HER2 expression and Ki67 index correlated significantly with grading but there was a significant difference only between G1 and G3 related to the ER and PR status, HER2 expression and Ki67 index. There was no statistically significant difference in lesion size between the two groups. Conclusion: ADC values obtained on 3 T DWI correlated with low-grade (G1) and high-grade (G3) invasive breast carcinoma. 3

  2. Variance of volume estimators

    Czech Academy of Sciences Publication Activity Database

    Janáček, Jiří

    Jena : Friedrich-Schiller-Universität, 2007. s. 23-23. [Workshop on Stochastic Geometry, Stereology and Image Analysis /14./. 23.09.2007-28.09.2007, Neudietendorf] R&D Projects: GA AV ČR(CZ) IAA100110502 Institutional research plan: CEZ:AV0Z50110509 Keywords : spr2 * stereology * volume * variance Subject RIV: EA - Cell Biology

  3. Volume measuring system

    Science.gov (United States)

    Oele, J. S.

    1975-01-01

    Chamber is designed to be airtight; it includes face mask for person to breathe outside air so that he does not disturb chamber environment. Chamber includes piston to vary air volume inside. Also included are two microphone transducers which record pressure information inside chamber.

  4. Overview of the Volume

    Science.gov (United States)

    Dennis, Brian R.; Emslie, A. G.; Hudson, H. S.

    2011-01-01

    In this introductory chapter, we provide a brief summary of the successes and remaining challenges in understanding the solar flare phenomenon and its attendant implications for particle acceleration mechanisms in astrophysical plasmas. We also provide a brief overview of the contents of the other chapters in this volume, with particular reference to the well-observed flare of 2002 July 23.

  5. Is Quantum Suicide Painless? On an Apparent Violation of The Principal Principle

    CERN Document Server

    Cirkovic, M M

    2004-01-01

    The experimental setup of the self-referential quantum measurement, jovially known as the "quantum suicide" or the "quantum Russian roulette" is analyzed from the point of view of the Principal Principle of David Lewis. It is shown that the apparent violation of this principle--relating objective probabilities and subjective chance--in this type of thought experiment is just an illusion due to the usage of some terms and concepts ill-defined in the quantum context. We conclude that even in the case that Everett's (or some other "no-collapse") theory is a correct description of reality, we can coherently believe in equating subjective credence with objective chance in quantum-mechanical experiments. This is in agreement with results of the research on personal identity in the quantum context by Parfit and Tappenden.

  6. The influence of actual and apparent geoid error on ocean analysis and prediction

    Science.gov (United States)

    Thompson, J. D.

    1984-01-01

    The radar altimeter is the only satellite remote sensor with a proven capability for synoptically measuring an integral property of the dynamic ocean on a near global, all weather basis. Because acquisition of global, in situ ocean data with space/time resolution adequate to describe dynamically important ocean features is practically impossible, any attempt to develop a global ocean monitoring and forecasting system will rely heavily on altimetric data for initialization and updating. Maximizing useful information from the altimeter while minimizing error sources and developing methods for assimilating altimeter data into dynamical models are, therefore, vital areas for research and development. The limits imposed on ocean prediction by errors in the geoid or apparent errors associated with ground track variations near strong geopotential gradients are examined.

  7. Measurement of Apparent Thermal Conductivity and Laser Absorptivity of Individual Carbon Fibers

    Science.gov (United States)

    Liu, Jin-hui; Wang, Hai-dong; Hu, Yu-dong; Ma, Wei-gang; Zhang, Xing

    2015-11-01

    The apparent thermal conductivity (ATC) and laser absorptivity (α ) are important properties of miro/nano materials but a challenge to measure due to their small size. In this paper, a simple and effective method employing Raman spectroscopy together with electrical heating is developed to measure thermal properties of micro/nano wires. The sample used in the experiment is very simple and easy to fabricate. The ATC is obtained by measuring the temperature difference induced by changing the electrical heating power; the laser heating power is neither neglected nor needed. Using the laser heating temperature rise and the measured ATC, the absorbed laser power can be calculated. Three individual carbon fibers were studied using the presented method.

  8. The sopite syndrome revisited: Drowsiness and mood changes during real or apparent motion

    Science.gov (United States)

    Lawson, B. D.; Mead, A. M.

    The sopite syndrome is a poorly understood response to motion. Drowsiness and mood changes are the primary characteristics of the syndrome. The sopite syndrome can exist in isolation from more apparent symptoms such as nausea, can last long; after nausea has subsided, and can debilitate some individuals. It is most likely a distinct syndrome from "regular" motion sickness or common fatigue, and is of potential concern in a variety of situations. The syndrome may be particularly hazardous in transportation settings where other performance challenges (e.g., sleep deprivation) are already present. It is also a potential concern in cases where illnesses such as sleep disorders or depression may interact with the syndrome and confuse diagnosis.

  9. The Apparent Lack of Lorentz Invariance in Zero-Point Fields with Truncated Spectra

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2009-01-01

    Full Text Available The integrals that describe the expectation values of the zero-point quantum-field- theoretic vacuum state are semi-infinite, as are the integrals for the stochastic electro- dynamic vacuum. The unbounded upper limit to these integrals leads in turn to infinite energy densities and renormalization masses. A number of models have been put for- ward to truncate the integrals so that these densities and masses are finite. Unfortunately the truncation apparently destroys the Lorentz invariance of the integrals. This note ar- gues that the integrals are naturally truncated by the graininess of the negative-energy Planck vacuum state from which the zero-point vacuum arises, and are thus automati- cally Lorentz invariant.

  10. The Apparent Lack of Lorentz Invariance in Zero-Point Fields with Truncated Spectra

    Directory of Open Access Journals (Sweden)

    Daywitt W. C.

    2009-01-01

    Full Text Available The integrals that describe the expectation values of the zero-point quantum-field-theoretic vacuum state are semi-infinite, as are the integrals for the stochastic electrodynamic vacuum. The unbounded upper limit to these integrals leads in turn to infinite energy densities and renormalization masses. A number of models have been put forward to truncate the integrals so that these densities and masses are finite. Unfortunately the truncation apparently destroys the Lorentz invariance of the integrals. This note argues that the integrals are naturally truncated by the graininess of the negative-energy Planck vacuum state from which the zero-point vacuum arises, and are thus automatically Lorentz invariant.

  11. Distribution of Aspergillus species among apparently healthy birds in poultry farms in Kaduna state, Nigeria

    Directory of Open Access Journals (Sweden)

    Clara N Kwanashie

    2013-03-01

    Full Text Available The study wasconducted to determine the prevalence and distribution of Aspergilllus species among apparently healthy birds in poultryfarms. Trachea swabs from 1500 birds in 52 commercial (10% of birds in eachpoultry farm visited poultry farms were collected for this study. Six speciesof Aspergillus were isolated wasisolated from 718 (47.87% of the birds viz: A. fumigatus made up 52.37% (376 of the Aspergillus isolates followed by A. flavus 21.87% (157, A.niger 11.42% (82, A. terreus8.64% (62, A. restrictus 2.79% (20and A. ochraceous 2.92% (21. Aspergillus species was found to occurthroughout the year in the farms though with a higher incidence during therainy season compared to the dry season.

  12. Evaluation of apparent standard potentials of curium in LiCl-KCl eutectic melt

    International Nuclear Information System (INIS)

    Electrochemical properties of curium (Cm-244) dissolved in LiCl-KCl eutectic melt were studied in the temperature range of 718 - 823 K. A small electrochemical cell used in the present study was designed to measure electrochemical properties of highly radioactive Cm-244, the maximum handling amount of which is 30 mg in our hot cells, dissolved in molten salts. Apparent standard potentials of Cm3+/Cm couple obtained in the present study, E°* (Cm3+/Cm) = (-3.236 ± 0.011) + (4.86 ± 0.14) × 10-4 T, reasonably agree with Osipenko's data (2011) and are lower than Martinot's data (1975). The validity of the data obtained in the present study was discussed by comparing with the reported data of other transuranic elements. (author)

  13. [Severe apparent life-threatening event during "skin-to-skin": treatment with hypothermia].

    Science.gov (United States)

    Marin, N; Valverde, E; Cabañas, F

    2013-10-01

    'Skin-to-skin' in healthy newborn infants is currently routine practice in Spanish maternity wards. This practice has shown benefits in increasing the duration of breast-feeding and maternal bonding behaviour with no significant adverse events. Early sudden deaths and severe apparent life-threatening events (ALTE) during the first 24 hours of life are infrequent, but well recognised. Risk factors during 'skin to skin' have been established. These events can lead to high neonatal morbidity and mortality. Hypothermia is now the standard of care for moderate to severe hypoxic-ischaemic encephalopathy and has shown to reduce mortality and neurological morbidity in children with hypoxic-ischaemic brain injury. Although there are no clinical trials that evaluate hypothermia after a severe ALTE, neonates who suffer it should be considered for this treatment. We present a case of a healthy newborn who had an ALTE during skin-to-skin with his mother and was treated with hypothermia. PMID:24051185

  14. Dark Energy or Apparent Acceleration Due to a Relativistic Cosmological Model More Complex than FLRW?

    CERN Document Server

    Ishak, Mustapha; Whittington, Delilah; Garred, David

    2007-01-01

    We use the Szekeres inhomogeneous relativistic models in order to fit supernova combined data sets. We show that with a choice of the spatial curvature function that is guided by current observations, the models fit the supernova data as well as the LCDM model without requiring any dark energy component. The Szekeres models were originally derived as an exact solution to Einstein's equations with a general metric that has no symmetries and are regarded in the field as good candidates to represent the true lumpy universe that we observe. The best fit model found is also consistent with the requirement of spatial flatness at CMB scales. While more work remains, the result presented in this first paper appears to support the possibility of apparent acceleration.

  15. Impact of Hygrothermal and Loading Conditions on Apparent Diffusivity of GFRP Composites

    Directory of Open Access Journals (Sweden)

    Sushma SINGH

    2014-02-01

    Full Text Available Glass fibre-reinforced polymer (GFRP has been used as an alternative to steel in concrete due to high strength-to-weight ratio, high stiffness-to-weight ratio, and corrosion and fatigue resistance. The main environmental factors for the deterioration of GFRP sandwich composites are temperature, sunshine, water/moisture, alkalinity and load. Most of the early durability tests were carried out with reference to application of FRP (Fibre Reinforced Polymer in aerospace industries. Hygrothermal behaviour of preloaded sandwich structure immersed in water is examined herein. Moisture uptake was monitored for 50 days yielding percentage weight gain curves for samples of matrix (epoxy and sandwich structure with different core thickness. The apparent diffusivity values extracted from the weight gain are significantly greater for initial days for greater core thickness sandwich structures.

  16. Hawking Radiation of Apparent Horizon in a FRW Universe as Tunneling Beyond Semiclassical Approximation

    Science.gov (United States)

    Jiang, Ke-Xia; Feng, Tsun; Peng, Dan-Tao

    2009-07-01

    An analysis of Hawking radiation about apparent horizon in a FRW universe is performed by using the method developed in the paper (Banerjee, Majhi in JHEP 06:095 2008), in which the Hawking radiation of a black hole is treated as the quantum tunneling by Hamilton-Jacobi method beyond semiclassical approximation and then all the higher order quantum corrections can be given out. In our analysis, the Kodama vector instead of the Killing vector to define the energy of the particle plays a key role. We present our analysis under the Friedmann-Robertson-Walker like coordinate system and the much-like to Painlevé coordinate system respectively. The result show that the formulized procedure can be extended to fully analyse the Hawking radiation of a dynamical system.

  17. Isolation and characterization of Clostridium perfringens from apparently healthy animals of the Shandong province of China.

    Science.gov (United States)

    Chai, T; Wang, L; Wang, H; Duan, H; Müller, W; Zucker, B A

    2007-10-01

    In a pilot study the presence and frequency of Clostridium (C.) perfringens was investigated among apparently healthy farm animals in the Shandong province of China. 748 faecal samples were collected from 9 pig-, 4 sheep-, 7 cattle- and 5 rabbit farms. C. perfringens was isolated from 124 samples (16.6%). The isolates were classified into major toxin types by using PCR analysis detecting the genes encoding these toxins. All isolates were identified as C perfringens toxin type A. There are also some reports from different regions in China linking C. perfringens toxin type A strains to gastrointestinal diseases. Therefore further investigations about the epidemiologic role of C perfringens toxin type A strains in the Shandong region are necessary. Currently, cases of enterotoxemia from this region are investigated for the presence of C perfringens. PMID:17970339

  18. Apparent Temperature and Cause-Specific Emergency Hospital Admissions in Greater Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Wichmann, Janine; Andersen, Zorana; Ketzel, Matthias;

    2011-01-01

    One of the key climate change factors, temperature, has potentially grave implications for human health. We report the first attempt to investigate the association between the daily 3-hour maximum apparent temperature (Tapp(max)) and respiratory (RD), cardiovascular (CVD), and cerebrovascular (CBD...... IQR (8°C) increase in the 5-day cumulative average of Tapp(max), a 7% (95% CI: 1%, 13%) increase in the RD admission rate was observed in the warm period whereas an inverse association was found with CVD (-8%, 95% CI: -13%, -4%), and none with CBD. There was no association between the 5-day cumulative...... average of Tapp(max) during the cold period and any of the cause-specific admissions, except in some susceptible groups: a negative association for RD in the oldest age group and a positive association for CVD in men and the second highest SES group. In conclusion, an increase in Tapp(max) is associated...

  19. Dr Brasilia and Mr. Nacala: the apparent duality behind the Brazilian state-capital nexus

    Directory of Open Access Journals (Sweden)

    TOMASO FERRANDO

    2015-06-01

    Full Text Available In August 2010 Brazil decided to limit foreign direct investments (FDIs in land, and attracted the attention of politicians as much as the fears of businessmen. However, few months before, in September 2009, it had concluded a trilateral agreement with Japan and Mozambique to implement agribusiness and contract farming on an area of ten million hectares in the Mozambican region of Nacala. In light of that, the paper analyses the apparent duality of the Brazilian politics, and concludes that, exactly like in the case of the novel by Robert Louis Stevenson, it is not a matter of pathology, but a voluntarily induced double personality which is strategic in positioning Brazil at the core of the global capitalist system.

  20. Radiographic and manometric correlation in achalasia with apparent lower esophageal sphincter relaxation

    International Nuclear Information System (INIS)

    The authors compared the clinical, radiographic, and manometric findings in ten patients with atypical achalasia showing complete but short-duration lower esophageal sphincter (LES) relaxation with findings in 39 patients with classic achalasia. Patients with atypical achalasia were younger, had dysphagia and weight loss of shorter duration, and had less esophageal dilation than patients with classic achalesia. LES pressure and esophagogastric junction caliber, however, were similar in the two groups. The majority of patients in both groups responded well to pneumatic dilation. They conclude that achalasia with apparent LES relaxation may represent an early form of this motor disorder and that the radiographic findings remain characteristic except for less dilation of the esophagus

  1. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    International Nuclear Information System (INIS)

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies (3H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound (3H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the (3H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand

  2. Apparent rate constant mapping using hyperpolarized [1-(13) C]pyruvate

    DEFF Research Database (Denmark)

    Khegai, O.; Schulte, R. F.; Janich, M. A.;

    2014-01-01

    Hyperpolarization of [1-13C]pyruvate in solution allows real-time measurement of uptake and metabolism using MR spectroscopic methods. After injection and perfusion, pyruvate is taken up by the cells and enzymatically metabolized into downstream metabolites such as lactate, alanine, and bicarbonate...... the build-up of downstream metabolites from the pyruvate substrate) and (ii) an effective decay rate (summarizing signal depletion due to repetitive excitation, T1-relaxation and backward conversion). The presented spectral and kinetic quantification were experimentally verified in vitro and in vivo...... shift frequencies are automatically estimated using a matching pursuit algorithm. Second, a time-discretized formulation of the two-site exchange kinetic model is used to quantify metabolite signal dynamics by two characteristic rate constants in the form of (i) an apparent build-up rate (quantifying...

  3. Apparent diffusion coefficient ratio correlates significantly with prostate cancer gleason score at final pathology

    DEFF Research Database (Denmark)

    Boesen, Lars; Chabanova, Elizaveta; Løgager, Vibeke; Balslev, Ingegerd; Thomsen, Henrik S

    2015-01-01

    PURPOSE: To evaluate the correlation between apparent diffusion coefficient measurements (ADCtumor and ADCratio ) and the Gleason score from radical prostatectomy specimens. MATERIALS AND METHODS: Seventy-one patients with clinically localized prostate cancer scheduled for radical prostatectomy...... correlated with the Gleason score from the prostatectomy specimens. RESULTS: The association between ADC measurements and Gleason score showed a significant negative correlation (P < 0.001) with Spearman's rho for ADCtumor (-0.421) and ADCratio (-0.649). There was a statistically significant difference...... ) and 0.90 (ADCratio ) when discriminating Gleason score ≤7(3+4) from Gleason score ≥7(4+3). CONCLUSION: ADC measurements showed a significant correlation with tumor Gleason score at final pathology. The ADCratio demonstrated the best correlation compared to the ADCtumor value and radically improved...

  4. The effect of age on apparent diffusion coefficient values in normal spleen: A preliminary study

    International Nuclear Information System (INIS)

    Aim: To investigate and characterize the effect of age on apparent diffusion coefficient (ADC) values in normal spleen. Materials and methods: A population of 127 patients (age range 10–79 years, mean age 44.4 years) without magnetic resonance imaging findings in abdominal scans, was selected over a 5-year period. The ADC values of the spleen were analysed in all ages, and dependency of ADC values on age was characterized using Spearman's correlation coefficient test. Results: A reduction of ADC values with ageing was found in the spleen (r = −0.702, p < 0.001). Conclusions: The ADC values of the spleen decline with age. This should be taken into consideration when disease is diagnosed

  5. Congestive Heart Failure With Apparently Preserved Left Ventricular Systolic Function: A 10-Year Observational Study.

    Science.gov (United States)

    El-Menyar, Ayman; Shabana, Adel; Arabi, Abdulrahman; Al-Thani, Hassan; Asaad, Nidal; AlBinALi, Hajar; Singh, Rajvir; Gomaa, Mohammed; Gehani, A

    2015-09-01

    We analyzed the clinical presentation and outcomes (from 2003 to 2013) of heart failure (HF) with apparently normal systolic function (HFPEF). Based on the echocardiographic left ventricular ejection fraction (LVEF), patients were divided into 2 groups, group 1 (<50%) and group 2 (≥50%). Of 2212 patients with HF, 20% were in group 2. Patients in group 2 were more likely to be older, females, Arabs, hypertensive, and obese (P = .001). Patients in group 1 were mostly Asians and had more troponin-T positivity (P = .001). Inhospital cardiac arrest, shock, and deaths were significantly greater in group 1. On multivariate analysis, age, ST-segment elevation myocardial infarction, lack of on-admission β-blockers, and angiotensin-converting enzyme inhibitors use were independent predictors of mortality. HFPEF is associated with less mortality compared to those who presented with reduced LVEF. On admission, use of evidence-based medications could in part predict this difference in the hospital outcome. PMID:25248442

  6. Fmoc-diphenylalanine self-assembly mechanism induces apparent pKa shifts.

    Science.gov (United States)

    Tang, Claire; Smith, Andrew M; Collins, Richard F; Ulijn, Rein V; Saiani, Alberto

    2009-08-18

    We report the effect of pH on the self-assembly process of Fmoc-diphenylalanine (Fmoc-FF) into fibrils consisting of antiparallel beta-sheets, and show that it results in two apparent pKa shifts of approximately 6.4 and approximately 2.2 pH units above the theoretical pKa (3.5). Using Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), wide angle X-ray scattering (WAXS), and oscillatory rheology, these two transitions were shown to coincide with significant structural changes. An entangled network of flexible fibrils forming a weak hydrogel dominates at high pH, while nongelling flat rigid ribbons form at intermediate pH values. Overall, this study provides further understanding of the self-assembly mechanism of aromatic short peptide derivatives. PMID:19537819

  7. Decreased trabecular bone biomechanical competence, apparent density, IGF-II and IGFBP-5 content in acromegaly

    DEFF Research Database (Denmark)

    Ueland, Thor; Ebbesen, Ebbe Nils; Thomsen, Jesper Skovhus;

    2002-01-01

    BACKGROUND: Earlier studies on the effect of excess growth hormone (GH) on trabecular bone have been conflicting. Since insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) in part mediate the effects of GH, the present study aimed to investigate trabecular bone composition of...... found in trabecular bone content of IGF-I, IGFBP-3, or osteocalcin. However, IGF-II and IGFBP-5 content was decreased (P < 0.001 and P < 0.05, respectively). CONCLUSIONS: The present study demonstrates reduced trabecular biomechanical competence and apparent density in acromegaly, supporting previous...... observations of an unfavourable effect of chronic excess GH on the axial skeleton. Furthermore, we demonstrate decreased trabecular bone content of IGF-II and IGFBP-5 in these patients. However, we found no direct causal relationship between trabecular bone density and bone content of IGF-system components....

  8. Des apparences fantasmées dans les fabliaux érotiques

    Directory of Open Access Journals (Sweden)

    Sophie Poitral

    2008-08-01

    Full Text Available Résumé : Composés de la fin du XIIe siècle au XIVe siècle, les fabliaux érotiques posent la question du corps et de son langage. Ses composantes - vêtement, physionomie, allure et gestuelle - participent à la duperie qui caractérise bien souvent l’univers des fabliaux. L’analyse des emplois de l’apparence dans quelques fabliaux érotiques français, aux auteurs anonymes ou connus, permet de définir le rôle central des apparences dans les stratagèmes mis en œuvre et montre la richesse des enjeux du paraître dans l’érotisme occidental du Moyen Âge : le travestissement sexuel est traité de manières différentes selon les sexes. L’apparence féminine de l’homme leurre le mari et permet à la femme rusée de commettre l’adultère, tandis que la femme travestie en homme soulève la question du pouvoir et du sexe dans la relation conjugale et dans la société. D’autre part, le déguisement parodique masque l’identité de celui qui trompe par ses faux-semblants et accumule les situations carnavalesques qui tournent à l’avantage de l’imposteur. Le mirage érotique met quant à lui en question le regard du voyeur, victime d’une illusion d’optique, et enfin le langage métamorphose l’apparence des organes sexuels, aux dépens des jeunes filles innocentes.Abstract : Analysing fantasised appearances in erotic fabliaux Erotic fabliaux, poems composed from the late 12th to the 14th century, bring into focus the question of the body and its language. Its various constituents - clothes, physionomy, bearing and body movements - all contribute to producing the deceit which is so characteristic of the world of fabliaux. Analysing how looks are exploited in a couple of French fabliaux both by unknown or renowned writers enables us better to define the key function of looks in the various strategies thus developed and to see just how complex and fundamental questions of aspect are in medieval western eroticism

  9. Some apparently disjoint aims and requirements for grammar development environments the case of natural language generation

    CERN Document Server

    Bateman, J A

    1997-01-01

    Grammar development environments (GDE's) for analysis and for generation have not yet come together. Despite the fact that analysis-oriented GDE's (such as ALEP) may include some possibility of sentence generation, the development techniques and kinds of resources suggested are apparently not those required for practical, large-scale natural language generation work. Indeed, there is no use of `standard' (i.e., analysis-oriented) GDE's in current projects/applications targetting the generation of fluent, coherent texts. This unsatisfactory situation requires some analysis and explanation, which this paper attempts using as an example an extensive GDE for generation. The support provided for distributed large-scale grammar development, multilinguality, and resource maintenance are discussed and contrasted with analysis-oriented approaches.

  10. No apparent lock-in depth of the Laschamp geomagnetic excursion: Evidence from the Malan loess

    Institute of Scientific and Technical Information of China (English)

    ZHU; Rixiang; LIU; Qingsong; PAN; Yongxin; DENG; Chenglong; ZHANG; Rui; WANG; Xianfeng

    2006-01-01

    The first-order chronological framework of the long-term Chinese loess/paleosol sequences was based mainly on magnetostratigraphy. However, there remain arguments on the lock-in ages of the major geomagnetic reversals. This study systematically compared the stratigraphic locations of the Laschamp excursion and Henrich events (H4 at~39 ka and H5 at~48 ka) recorded by the Luochuan loess profile in the central Chinese Loess Plateau. Results show that the Lascchamp excursion is bracketed well by these two cold events, and the corresponding estimated age is between about 41.7-43.7 ka, which is close to the widely accepted age of ~40-41 ka for the excursion.Therefore, our new results do not suggest apparent lock-in effects in the last glacial Malan loess.

  11. Turing patterns and apparent competition in predator-prey food webs on networks

    CERN Document Server

    Fernandes, Lucas D

    2012-01-01

    Reaction-diffusion systems may lead to the formation of steady state heterogeneous spatial patterns, known as Turing patterns. Their mathematical formulation is important for the study of pattern formation in general and play central roles in many fields of biology, such as ecology and morphogenesis. In the present study we focus on the role of Turing patterns in describing the abundance distribution of predator and prey species distributed in patches in a scale free network structure. We extend the original model proposed by Nakao and Mikhailov by considering food chains with several interacting pairs of preys and predators. We identify patterns of species distribution displaying high degrees of apparent competition driven by Turing instabilities. Our results provide further indication that differences in abundance distribution among patches may be, at least in part, due to self organized Turing patterns, and not necessarily to intrinsic environmental heterogeneity.

  12. Turing patterns and apparent competition in predator-prey food webs on networks

    Science.gov (United States)

    Fernandes, L. D.; de Aguiar, M. A. M.

    2012-11-01

    Reaction-diffusion systems may lead to the formation of steady-state heterogeneous spatial patterns, known as Turing patterns. Their mathematical formulation is important for the study of pattern formation in general and plays central roles in many fields of biology, such as ecology and morphogenesis. Here we show that Turing patterns may have a decisive role in shaping the abundance distribution of predators and prey living in patchy landscapes. We extend the original model proposed by Nakao and Mikhailov [Nat. Phys.1745-247310.1038/nphys1651 6, 544 (2010)] by considering food chains with several interacting pairs of prey and predators distributed on a scale-free network of patches. We identify patterns of species distribution displaying high degrees of apparent competition driven by Turing instabilities. Our results provide further indication that differences in abundance distribution among patches can be generated dynamically by self organized Turing patterns and not only by intrinsic environmental heterogeneity.

  13. STUDY OF ANEMIA IN APPARENTLY HEALTHY CHILDREN AGED 6 TO 15 MONTHS

    Directory of Open Access Journals (Sweden)

    Fysal

    2013-12-01

    Full Text Available Anemia due to lack of iron is the most important hematological disorder of infancy and childhood. According to India’s third National Family Health Survey ( NFHS - 3 of 2005 - 6 , 70 % of children between 6 months and 59 months are anemic. So it is very important to screen children for anemia early. The first 2 years of life is a critical window of opportunity to intervene in children since anemia can impair psychomotor development. A cross sectional study involving 260 apparently healthy children between 6 months and 15 months of age , showed the prevalence of anemia to be 60.7%. Only 9.2% of them were having Protein Energy Malnutrition. Introduction of animal milk at an early age and the amount of animal milk consumed were found to be the two important risk factors significantly associated with anemia. KEY WORDS: Hemoglobin , Protein Energy Malnutrition ( PEM , Microcytic Hypochromic Anemia , Exclusive Breast Feeding ( EBF

  14. Apparent diffusion coefficients of normal uterus in premenopausal women with 3 T MRI

    International Nuclear Information System (INIS)

    Aim: To investigate the apparent diffusion coefficient (ADC) values of the normal uterine cervical zonal structures (cervical epithelium, the junctional zone, and myometrium) during different phases of the menstrual cycle among premenopausal women in different age groups. Materials and methods: Seventy healthy women, who were divided into three age groups (group A, 24 women in their twenties; group B, 23 women in their thirties; group C, 23 women in their forties), underwent 3 T magnetic resonance imaging (MRI) with T2-weighted and diffusion-weighted imaging (DWI) during the mid-proliferative and the mid-secretory phases. Results: The ADC values of each cervical zonal structure were significantly different from one another (p 0.05). Conclusion: ADC values of normal cervical epithelium and the junctional zone change with different phases of the menstrual cycle, which should be taken into consideration when early cervical disease is detected, when monitoring treatment response, and differentiating early tumour recurrence

  15. Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Khurgin, Jacob B., E-mail: jakek@jhu.edu [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Bajaj, Sanyam; Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-12-28

    Longitudinal optical (LO) phonons in GaN generated in the channel of high electron mobility transistors (HEMT) are shown to undergo nearly elastic scattering via collisions with hot electrons. The net result of these collisions is the diffusion of LO phonons in the Brillouin zone causing reduction of phonon and electron temperatures. This previously unexplored diffusion mechanism explicates how an increase in electron density causes reduction of the apparent lifetime of LO phonons, obtained from the time resolved Raman studies and microwave noise measurements, while the actual decay rate of the LO phonons remains unaffected by the carrier density. Therefore, the saturation velocity in GaN HEMT steadily declines with increased carrier density, in a qualitative agreement with experimental results.

  16. Global Lithospheric Apparent Susceptibility Distribution Converted from Geomagnetic Models by CHAMP and Swarm Satellite Magnetic Measurements

    Science.gov (United States)

    Du, Jinsong; Chen, Chao; Xiong, Xiong; Li, Yongdong; Liang, Qing

    2016-04-01

    Recently, because of continually accumulated magnetic measurements by CHAMP satellite and Swarm constellation of three satellites and well developed methodologies and techniques of data processing and geomagnetic field modeling etc., global lithospheric magnetic anomaly field models become more and more reliable. This makes the quantitative interpretation of lithospheric magnetic anomaly field possible for having an insight into large-scale magnetic structures in the crust and uppermost mantle. Many different approaches have been utilized to understand the magnetized sources, such as forward, inversion, statistics, correlation analysis, Euler deconvolution, signal transformations etc. Among all quantitative interpretation methods, the directly converting a magnetic anomaly map into a magnetic susceptibility anomaly map proposed by Arkani-Hamed & Strangway (1985) is, we think, the most fast quantitative interpretation tool for global studies. We just call this method AS85 hereinafter for short. Although Gubbins et al. (2011) provided a formula to directly calculate the apparent magnetic vector distribution, the AS85 method introduced constraints of magnetized direction and thus corresponding results are expected to be more robust especially in world-wide continents. Therefore, in this study, we first improved the AS85 method further considering non-axial dipolar inducing field using formulae by Nolte & Siebert (1987), initial model or priori information for starting coefficients in the apparent susceptibility conversion, hidden longest-wavelength components of lithospheric magnetic field and field contaminations from global oceanic remanent magnetization. Then, we used the vertically integrated susceptibility model by Hemant & Maus (2005) and vertically integrated remanent magnetization model by Masterton et al. (2013) to test the validity of our improved method. Subsequently, we applied the conversion method to geomagnetic field models by CHAMP and Swarm satellite

  17. Cooperative phenomena in apparent movement perception of random-dot cinematograms.

    Science.gov (United States)

    Chang, J J; Julesz, B

    1984-01-01

    To determine if apparent movement perception of random-dot cinematograms (RDC) is a cooperative process, we examined the interaction between adjacent areas whose movement, when perceived independently, was in opposite directions. The stimulus contained alternating ambiguous and unambiguous horizontal random-dot stripes of equal width. The ambiguous areas were biased in a specific direction opposite to the movement of the unambiguous areas. The cooperative process was evaluated by noting that the unambiguous areas were able to reverse the perceived direction of the ambiguous areas. Thus all dots were seen to move uniformly in the unambiguous direction. This phenomenon was dependent on the amount of bias inserted in the ambiguous areas and the width of the stripes. A Cooperative Strength (CS) index was computed. We found that CS depended on the stripe width, and that the average cooperative neighborhood was about 15 min arc in visual angle, suggesting a relationship to the diameter of cortical hypercolumns. PMID:6534001

  18. De Novo Thrombotic Microangiopathy Immediately After Kidney Transplant in Patients Without Apparent Risk Factors.

    Science.gov (United States)

    Patel, Ankita; Knorr, John P; Campos, Stalin; Khanmoradi, Kamran; Zaki, Radi F; Bradauskaite, Gitana

    2016-04-01

    Thrombotic microangiopathy refers to a spectrum of conditions that share a common underlying pathologic mechanism that result in endothelial damage and microangiopathic hemolytic anemia. De novo thrombotic microangiopathy after kidney transplant is often triggered by immunosuppressive drugs, and studies most often implicate calcineurin inhibitors and/or mammalian target of rapamycin inhibitors; however, muromonab and alemtuzumab also reportedly cause thrombotic microangiopathy. In addition, thrombotic microangiopathy may be triggered by acute antibody-mediated rejection and infections like cytomegalovirus and parvovirus. Here, we present a case series of 3 patients without any apparent risk factors (eg, acute antibody-mediated rejection) who developed de novo thrombotic microangiopathy immediately following kidney transplant, but before the introduction of calcineurin inhibitors. Two of these 3 patients were successfully managed with plasma exchange, and calcineurin inhibitors were successfully introduced without the recurrence of thrombotic microangiopathy. PMID:26030297

  19. Apparent Temperature and Cause-Specific Mortality in Copenhagen, Denmark: A Case-Crossover Analysis

    Directory of Open Access Journals (Sweden)

    Steffen Loft

    2011-09-01

    Full Text Available Temperature, a key climate change indicator, is expected to increase substantially in the Northern Hemisphere, with potentially grave implications for human health. This study is the first to investigate the association between the daily 3-hour maximum apparent temperature (Tappmax, and respiratory, cardiovascular and cerebrovascular mortality in Copenhagen (1999–2006 using a case-crossover design. Susceptibility was investigated for age, sex, socio-economic status and place of death. For an inter-quartile range (7 °C increase in Tappmax, an inverse association was found with cardiovascular mortality (−7% 95% CI −13%; −1% and none with respiratory and cerebrovascular mortality. In the cold period all associations were inverse, although insignificant.

  20. The effect of interaural-time-difference fluctuations on apparent source width

    DEFF Research Database (Denmark)

    Käsbach, Johannes; May, Tobias; Oskarsdottir, Gudrun; Jeong, Cheol-Ho; Chang, Jiho

    2014-01-01

    For the perception of spaciousness, the temporal fluctuations of the interaural time differences (ITDs) and interaural level differences (ILDs) provide important binaural cues. One major characteristic of spatial perception is apparent source width (ASW), which describes the perceived width of a...... for the perception of ASW. However, the contribution of the ITD statistics on the percept of ASW has not yet been clarified. In the present study, the impact of ITD fluctuations in different frequency bands on the perceived ASW was investigated. In a psychoacoustic evaluation, a source signal was...... convolved with individual binaural room impulse responses (BRIRs) and presented to the listener via headphones. The obtained signals were passed through a gammatone filterbank with an analysis and synthesis stage which enabled the modification of the ITD fluctuation statistics in individual frequency bands...

  1. Septicemia with Streptococcus pseudopneumoniae: report of three cases with an apparent hepatic or bile duct association.

    Science.gov (United States)

    Fuursted, Kurt; Littauer, Pia Jeanette; Greve, Thomas; Scholz, Christian F P

    2016-08-01

    Streptococcus pseudopneumoniae was described in 2004 as a new human pathogen, acknowledged in a range of clinical infections typically associated to the respiratory tract. This report demonstrates that S. pseudopneumoniae has the potential to cause invasive infection. In blood cultures from three patients, growth of an atypical Streptococcus pneumoniae (non-capsular, non-serotypeable, optochin susceptible under ambient atmosphere and bile-intermediately soluble) was recovered. All three patients had a history of a haematological disease (myelodysplastic syndrome and multiple myeloma) and an apparent origin of infection related to the liver or bile duct. All isolates were genome sequenced and subsequently identified as S. pseudopneumoniae by multi-locus sequence analysis (MLSA). Multi-locus sequence typing (MLST) based on the S. pneumoniae scheme revealed unknown sequence types and the antibiogram and resistome revealed no antibiotic resistance. PMID:27100044

  2. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Benyhe, S.; Hoffman, G.; Varga, E.; Hosztafi, S.; Toth, G.; Borsodi, A.; Wollemann, M.

    1989-01-01

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies (/sup 3/H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound (/sup 3/H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the (/sup 3/H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand.

  3. Visual Benefits in Apparent Motion Displays: Automatically Driven Spatial and Temporal Anticipation Are Partially Dissociated.

    Science.gov (United States)

    Ahrens, Merle-Marie; Veniero, Domenica; Gross, Joachim; Harvey, Monika; Thut, Gregor

    2015-01-01

    Many behaviourally relevant sensory events such as motion stimuli and speech have an intrinsic spatio-temporal structure. This will engage intentional and most likely unintentional (automatic) prediction mechanisms enhancing the perception of upcoming stimuli in the event stream. Here we sought to probe the anticipatory processes that are automatically driven by rhythmic input streams in terms of their spatial and temporal components. To this end, we employed an apparent visual motion paradigm testing the effects of pre-target motion on lateralized visual target discrimination. The motion stimuli either moved towards or away from peripheral target positions (valid vs. invalid spatial motion cueing) at a rhythmic or arrhythmic pace (valid vs. invalid temporal motion cueing). Crucially, we emphasized automatic motion-induced anticipatory processes by rendering the motion stimuli non-predictive of upcoming target position (by design) and task-irrelevant (by instruction), and by creating instead endogenous (orthogonal) expectations using symbolic cueing. Our data revealed that the apparent motion cues automatically engaged both spatial and temporal anticipatory processes, but that these processes were dissociated. We further found evidence for lateralisation of anticipatory temporal but not spatial processes. This indicates that distinct mechanisms may drive automatic spatial and temporal extrapolation of upcoming events from rhythmic event streams. This contrasts with previous findings that instead suggest an interaction between spatial and temporal attention processes when endogenously driven. Our results further highlight the need for isolating intentional from unintentional processes for better understanding the various anticipatory mechanisms engaged in processing behaviourally relevant stimuli with predictable spatio-temporal structure such as motion and speech. PMID:26623650

  4. Visual Benefits in Apparent Motion Displays: Automatically Driven Spatial and Temporal Anticipation Are Partially Dissociated.

    Directory of Open Access Journals (Sweden)

    Merle-Marie Ahrens

    Full Text Available Many behaviourally relevant sensory events such as motion stimuli and speech have an intrinsic spatio-temporal structure. This will engage intentional and most likely unintentional (automatic prediction mechanisms enhancing the perception of upcoming stimuli in the event stream. Here we sought to probe the anticipatory processes that are automatically driven by rhythmic input streams in terms of their spatial and temporal components. To this end, we employed an apparent visual motion paradigm testing the effects of pre-target motion on lateralized visual target discrimination. The motion stimuli either moved towards or away from peripheral target positions (valid vs. invalid spatial motion cueing at a rhythmic or arrhythmic pace (valid vs. invalid temporal motion cueing. Crucially, we emphasized automatic motion-induced anticipatory processes by rendering the motion stimuli non-predictive of upcoming target position (by design and task-irrelevant (by instruction, and by creating instead endogenous (orthogonal expectations using symbolic cueing. Our data revealed that the apparent motion cues automatically engaged both spatial and temporal anticipatory processes, but that these processes were dissociated. We further found evidence for lateralisation of anticipatory temporal but not spatial processes. This indicates that distinct mechanisms may drive automatic spatial and temporal extrapolation of upcoming events from rhythmic event streams. This contrasts with previous findings that instead suggest an interaction between spatial and temporal attention processes when endogenously driven. Our results further highlight the need for isolating intentional from unintentional processes for better understanding the various anticipatory mechanisms engaged in processing behaviourally relevant stimuli with predictable spatio-temporal structure such as motion and speech.

  5. Protocol for determining Apparent Young's Modulus of human teeth using laser speckle interferometry

    Science.gov (United States)

    Salvador-Palmer, Rosario; González-Peña, Rolando J.; Martínez-Celorio, René A.; López, Francisco J.; Paredes, Vanessa; Cibrián, Rosa

    2012-10-01

    Digital Speckle Shearing Pattern Interferometry (DSSPI) allows to directly quantify deformations in teeth that are subjected to stress. Eighteen second premolars (2PM) were studied both before and after endodontic treatment made with the ProTaper method in order to evaluate the variation of dental elasticity. We present a protocol for determination tooth Apparent Young's Modulus (AYM). Each tooth underwent different flexion loads from 50 to 300 g. DSSPI technique, makes it possible to show the deformation at each point of a line, selected by the researcher, that goes from the attachment point (Point 0) to the root area where the load is applied (Point 300-350, depending on the tooth size). The deformation of each tooth was characterized by the deformation value of point 150, located around the mid-area of tooth. This value was obtained from a linear regression applied on the deformation values of all the points in the fitted line. The correlation coefficients of these fitted regression lines were always higher than 0.972. The elasticity constant of each tooth was obtained as the slope of a new regression line, corresponding to the different loads applied on the tooth versus the corresponding deformation at point 150. This value, divided by the length of the tooth, is the apparent Young's modulus (AYM), which is expressed in arbitrary units (a.u.). Values of the AYM before (4.16 104 a.u) and after endodontic treatment using the ProTaper method (4.30 104 a.u.) showed no statistically significant difference in the elasticity of teeth (p>0.7).

  6. Apparent Formation Factor for Leachate-Saturated Waste and Sediments: Examples from the USA and China

    Institute of Scientific and Technical Information of China (English)

    Philip J Carpenter; Ding Aizhong; Cheng Lirong; Liu Puxin; Chu Fulu

    2009-01-01

    The formation factor relates bulk resistivity to pore fluid resistivity in porous materials. Understanding the formation factor is essential in using electrical and electromagnetic methods to monitor leachate accumulations and movements both within and around landfills. Specifically, the formation factor allows leachate resistivity, the degree of saturation, and, possibly, even the hydraulic conductivity of the waste to be estimated from non-invasive surface measurements. In this study, apparent formation factors are computed for three landfills with different types of waste as well as sediments contaminated by landfill leachate. Resistivity soundings at the closed Mallard North landfill in suburban Chicago (Illinois, USA) mapped leachate surfaces that were confirmed by monitoring wells. The resistivity of leachate-saturated waste from resistivity sounding inversions was then divided by the leachate resistivity values measured in-situ to compute apparent formation factors (Fa) ranging from 1.6 to 4.9. A global Fa of 3.0±1.9 was computed for the entire monitored portion of this landfill At a nearby mixed laboratory waste landfill, a 2D inverted resistivity section was used to compute an Fa of 2.9. Finally, a distinctly different Fa value of 10.6±2.8 was computed for leachate-saturated retorted oil and organic compounds. The Fa for aquifers containing contaminated groundwater fall in the same range as aquifers with normal groundwater, 1.7-3.9. However, models from inverted sounding curves over these contaminated areas exhibit unusually low resistivity layers, which may be diagnostic of contamination.

  7. The association between arterial stiffness and left ventricular filling pressure in an apparently healthy Korean population

    Directory of Open Access Journals (Sweden)

    Kim Hack-Lyoung

    2013-01-01

    Full Text Available Abstract Background The aim of this study is to investigate the association between arterial stiffness and left ventricular filling pressure in an apparently healthy Korean population. Methods A total of 115 healthy subjects without known cardiovascular risk factors or overt heart disease who underwent both transthoracic echocardiography and brachial-ankle pulse wave velocity (baPWV measurement at the same day during their routine check-ups were analyzed. Results The mean age of study subjects was 52.8 ± 8.4 years, and 78 (67.8% were men. The mean baPWV value was 1,325 ± 185 cm/s. Study subjects were divided into 3 groups according to E/E’ value: subjects with E/E’ p β = 0.371, p after controlling confounders including age, sex and body mass index. In receiver-operating characteristic (ROC curve analysis, the sensitivity and specificity for detection of E/E’ ≥ 10 were 78.6% and 59.8%, respectively with mean baPWV of 1,282 cm/s as the cut off value. The discriminatory capacity for predicting E/E’ ≥ 10 was improved from an area under the ROC curve of 0.646 with age alone to 0.734 when baPWV was added (p Conclusions There is a significant association between baPWV and E/E’ in an apparently healthy Korean population. BaPWV is useful as a simple and non-invasive method for early detection of increased LV filling pressure among these people.

  8. Detection of Flux Emergence, Splitting, Merging, and Cancellation of Network Fields. II Apparent Unipolar Flux Change and Cancellation

    CERN Document Server

    Iida, Y; Yokoyama, T

    2015-01-01

    In this second paper in the series, we investigate occurrence frequencies of apparent unipolar processes, cancellation, and emergence of patch structures in quiet regions. Apparent unipolar events are considerably more frequent than cancellation and emergence as per our definition, which is consistent with Lamb et al. (2013). Furthermore, we investigate the frequency distributions of changes in flux during apparent unipolar processes are and found that they concentrate around the detection limit of the analysis. Combining these findings with the results of our previous paper, Iida et al. (2012), that merging and splitting are more dominant than emergence and cancellation, these results support the understanding that apparent unipolar processes are actually interactions with and among patches below the detection limit and that there still are numerous flux interactions between the flux range in this analysis and below the detection limit. We also investigate occurrence frequency distributions of flux decrease ...

  9. Can Apparent Stress be Used to Time-Dependent Seismic Hazard Assessment or Earthquake Forecast? An Ongoing Approach in China

    Science.gov (United States)

    Wu, Zhongliang; Jiang, Changsheng; Zhang, Shengfeng

    2016-08-01

    The approach in China since the last 1.5 decade for using apparent stress in time-dependent seismic hazard assessment or earthquake forecast is summarized. Retrospective case studies observe that apparent stress exhibits short-term increase, with time scale of several months, before moderate to strong earthquakes in a large area surrounding the `target earthquake'. Apparent stress is also used to estimate the tendency of aftershock activity. The concept relating apparent stress indirectly to stress level is used to understand the properties of some `precursory' anomalies. Meanwhile, different opinions were reported. Problems in the calculation also existed for some cases. Moreover, retrospective studies have the limitation in their significance as compared to forward forecast test. Nevertheless, this approach, seemingly uniquely carried out in a large scale in mainland China, provides the earthquake catalogs for the predictive analysis of seismicity with an additional degree of freedom, deserving a systematic review and reflection.

  10. Dense Shaped Refractory Products--Determination of Bulk Density, Apparent Porosity and True Porosity GB/T 2997-2000

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ 1 Scope This standard specifies the definition, principle, apparatus and materials, procedure, expression of results and test report of determination of bulk density, apparent porosity and true porosity of dense shaped refractory products.

  11. The Effect of the Operating Conditions on the Apparent Viscosity of Crude Palm Oil During Oil Clarification

    Directory of Open Access Journals (Sweden)

    Sulaiman Al-Zuhair, Mirghani I. Ahmed and Yousif A. Abakr

    2012-10-01

    Full Text Available This paper discusses the apparent viscosity of crude palm oil, using rotary viscometer, under different boundary conditions. It was experimentally shown that the apparent viscosity of palm oil drops with increasing of the shear rate and the temperature.  However, the effect of temperature on the viscosity tends to fade at temperatures beyond 80 oC.  A correlation between the apparent viscosity of crude palm oil and the operating conditions was developed. This correlation can be used in design of crude palm oil settlers and in determining the optimum operating conditions.Key Words:  Crude palm oil, apparent viscosity, shear rate, modelling, separation 

  12. Pretreatment Apparent Diffusion Coefficient of the Primary Lesion Correlates With Local Failure in Head-and-Neck Cancer Treated With Chemoradiotherapy or Radiotherapy

    International Nuclear Information System (INIS)

    Purpose: This study was performed to evaluate whether the apparent diffusion coefficient (ADC) of a primary lesion correlates with local failure in primary head-and-neck squamous cell carcinoma (HNSCC) treated with chemoradiotherapy or radiotherapy. Methods and Materials: We retrospectively studied 38 patients with primary HNSCC (12 oropharynx, 20 hypopharynx, 4 larynx, 2 oral cavity) treated with chemoradiotherapy or radiotherapy with radiation dose to gross tumor volume equal to or over 60 Gy and who underwent pretreatment magnetic resonance imaging, including diffusion-weighted imaging. Ten patients developed local failure during follow-up periods of 2.0 to 9.3 months, and the remaining 28 showed local control during follow-up periods of 10.5 to 31.7 months. The variables that could affect local failure (age, tumor volume, ADC, T stage, N stage, dose, treatment method, tumor location, and overall treatment time) were analyzed using logistic regression analyses for all 38 patients and for 17 patients with Stage T3 or T4 disease. Results: In univariate logistic analysis for all 38 cases, tumor volume, ADC, T stage, and treatment method showed significant (p < 0.05) associations with local failure. In multivariate analysis, ADC and T stage revealed significance (p < 0.01). In univariate logistic analysis for the 17 patients with Stage T3 or T4 disease, ADC and dose showed significant (p < 0.01) associations with local failure. In multivariate analysis, ADC alone showed significance (p < 0.05). Conclusions: The results suggest that pretreatment ADC, along with T stage, is a potential indicator of local failure in HNSCC treated with chemoradiotherapy or radiotherapy.

  13. The apparent diffusion coefficient does not reflect cytotoxic edema on the uninjured side after traumatic brain injury

    OpenAIRE

    Lu, Hong; Lei, Xiaoyan

    2014-01-01

    After traumatic brain injury, vasogenic and cytotoxic edema appear sequentially on the involved side. Neuroimaging investigations of edema on the injured side have employed apparent diffusion coefficient measurements in diffusion tensor imaging. We investigated the changes occurring on the injured and uninjured sides using diffusion tensor imaging/apparent diffusion coefficient and histological samples in rats. We found that, on the injured side, that vasogenic edema appeared at 1 hour and in...

  14. High Apparent Dielectric Constant Inside a Protein Reflects Structural Reorganization Coupled to the Ionization of an Internal Asp

    OpenAIRE

    Karp, Daniel A.; Gittis, Apostolos G; Stahley, Mary R.; Fitch, Carolyn A.; Stites, Wesley E.; García-Moreno E., Bertrand

    2006-01-01

    The dielectric properties of proteins are poorly understood and difficult to describe quantitatively. This limits the accuracy of methods for structure-based calculation of electrostatic energies and pKa values. The pKa values of many internal groups report apparent protein dielectric constants of 10 or higher. These values are substantially higher than the dielectric constants of 2–4 measured experimentally with dry proteins. The structural origins of these high apparent dielectric constants...

  15. Mixed volumes of hypersimplices

    OpenAIRE

    Liu, Gaku

    2014-01-01

    In this paper we consider mixed volumes of combinations of hypersimplices. These numbers, called "mixed Eulerian numbers", were first considered by A. Postnikov and were shown to satisfy many properties related to Eulerian numbers, Catalan numbers, binomial coefficients, etc. We give a general combinatorial interpretation for mixed Eulerian numbers and prove the above properties combinatorially. In particular, we show that each mixed Eulerian number enumerates a certain set of permutations in...

  16. Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach.

    Science.gov (United States)

    Sarkar, Abhijit; Sinha, Biswajit

    2016-11-15

    The densities and viscosities of lactose monohydrate in aqueous ascorbic acid solutions with several molal concentrations m=(0.00-0.08)molkg(-1) of ascorbic acid were determined at T=(298.15-318.15)K and pressure p=101kPa. Using experimental data apparent molar volume (ϕV), standard partial molar volume (ϕV(0)), the slope (SV(∗)), apparent specific volumes (ϕVsp), standard isobaric partial molar expansibility (ϕE(0)) and its temperature dependence [Formula: see text] the viscosity B-coefficient and solvation number (Sn) were determined. Viscosity B-coefficients were further employed to obtain the free energies of activation of viscous flow per mole of the solvents (Δμ1(0≠)) and of the solute (Δμ2(0≠)). Effects of molality, solute structure and temperature and taste behavior were analyzed in terms of solute-solute and solute-solvent interactions; results revealed that the solutions are characterized predominantly by solute-solvent interactions and lactose monohydrate behaves as a long-range structure maker. PMID:27283672

  17. Backward volume contraction for endomorphisms with eventual volume expansion

    OpenAIRE

    Pinheiro, Vilton; Castro, Armando; Alves, J. F.

    2009-01-01

    We consider smooth maps on compact Riemannian manifolds. We prove that under some mild condition of eventual volume expansion Lebesgue almost everywhere we have uniform backward volume contraction on every pre-orbit for Lebesgue almost every point.

  18. Anisotropic Ambient Volume Shading.

    Science.gov (United States)

    Ament, Marco; Dachsbacher, Carsten

    2016-01-01

    We present a novel method to compute anisotropic shading for direct volume rendering to improve the perception of the orientation and shape of surface-like structures. We determine the scale-aware anisotropy of a shading point by analyzing its ambient region. We sample adjacent points with similar scalar values to perform a principal component analysis by computing the eigenvectors and eigenvalues of the covariance matrix. In particular, we estimate the tangent directions, which serve as the tangent frame for anisotropic bidirectional reflectance distribution functions. Moreover, we exploit the ratio of the eigenvalues to measure the magnitude of the anisotropy at each shading point. Altogether, this allows us to model a data-driven, smooth transition from isotropic to strongly anisotropic volume shading. In this way, the shape of volumetric features can be enhanced significantly by aligning specular highlights along the principal direction of anisotropy. Our algorithm is independent of the transfer function, which allows us to compute all shading parameters once and store them with the data set. We integrated our method in a GPU-based volume renderer, which offers interactive control of the transfer function, light source positions, and viewpoint. Our results demonstrate the benefit of anisotropic shading for visualization to achieve data-driven local illumination for improved perception compared to isotropic shading. PMID:26529745

  19. 3D imaging of soil apparent electrical conductivity from VERIS data using a 1D spatially constrained inversion algorithm

    Science.gov (United States)

    Jesús Moral García, Francisco; Rebollo Castillo, Francisco Javier; Monteiro Santos, Fernando

    2016-04-01

    Maps of apparent electrical conductivity of the soil are commonly used in precision agriculture to indirectly characterize some important properties like salinity, water, and clay content. Traditionally, these studies are made through an empirical relationship between apparent electrical conductivity and properties measured in soil samples collected at a few locations in the experimental area and at a few selected depths. Recently, some authors have used not the apparent conductivity values but the soil bulk conductivity (in 2D or 3D) calculated from measured apparent electrical conductivity through the application of an inversion method. All the published works used data collected with electromagnetic (EM) instruments. We present a new software to invert the apparent electrical conductivity data collected with VERIS 3100 and 3150 (or the more recent version with three pairs of electrodes) using the 1D spatially constrained inversion method (1D SCI). The software allows the calculation of the distribution of the bulk electrical conductivity in the survey area till a depth of 1 m. The algorithm is applied to experimental data and correlations with clay and water content have been established using soil samples collected at some boreholes. Keywords: Digital soil mapping; inversion modelling; VERIS; soil apparent electrical conductivity.

  20. Apparent enrichment of organically bound tritium in rivers explained by the heritage of our past

    International Nuclear Information System (INIS)

    The global inventory of naturally produced tritium (3H) is estimated at 2.65 kg, whereas more than 600 kg have been released during atmospheric nuclear tests (NCRP, 1979; UNSCEAR, 2000) constituting the main source of artificial tritium throughout the Anthropocene. The behaviour of this radioactive isotope in the environment has been widely studied since the 1950s, both through laboratory experiments and, more recently, through field observations (e.g., Cline, 1953; Kirchmann et al., 1979; Daillant et al., 2004; McCubbin et al., 2001; Kim et al., 2012). In its “free” forms, [i.e. 3H gas or 3H hydride (HT); methyl 3H gas (CH3T); tritiated H2O or 3H-oxide (HTO); and Tissue Free Water 3H (TFWT)], tritium closely follows the water cycle. However, 3H bound with organic compounds, mainly during the basic stages of photosynthesis or through weak hydrogen links, is less exchangeable with water, which explains its persistence in the carbon cycle as re underlined recently by Baglan et al. (2013), Jean-Batiste and Fourré (2013), Kim et al. (2013a,b). In this paper, we demonstrate that terrestrial biomass pools, historically contaminated by global atmospheric fallout from nuclear testing, have constituted a significant delayed source of organically bound tritium (OBT) for aquatic systems, resulting in an apparent enrichment of OBT as compared to HTO. This finding helps to explain concentration factors (tritium concentration in biota/concentration in water) greater than 1 observed in areas that are not directly affected by industrial radioactive wastes, and thus sheds light on the controversies regarding tritium ‘bioaccumulation’. Such apparent enrichment of OBT is expected to be more pronounced in the Northern Hemisphere where fallout was most significant, depending on the nature and biodegradability of terrestrial biomass at the regional scale. We further believe that OBT transfers from the continent to oceans have been sufficient to affect tritium concentrations in

  1. Corps, apparences vestimentaires et identités en France à la Renaissance

    Directory of Open Access Journals (Sweden)

    Isabelle Paresys

    2012-02-01

    Full Text Available Un corps vêtu spécifique émerge à la Renaissance en France et particulièrement à la Cour. Le vêtement impose sa marque sur le corps, accentue le dimorphisme sexuel des apparences, et donne à celles-ci rectitude ou distorsion, transformant le corps en une surface décorative sur laquelle peut s’exprimer la magnificence des souverains et celle de leur cour. Ce corps vêtu résulte de l’influence de modes européennes et de nouvelles normes de civilité qui construisent la présentation de soi. Elles trouvent leur pleine expression à la cour où le corps de mode aristocratique affiche une éloquence distinctive et cosmopolite. Dans le même temps, les identités qu’inculque le vêtement au corps paraissent menacées par les transferts de pratiques vestimentaires entre les sexes, entre les groupes sociaux et entre les nations, entraînant un malaise envers ce brouillage des apparences qui prend une couleur particulière durant les guerres civiles quand se pose de manière sanglante la question des identités et de la conscience nationale.Body, Dress and Identities in Renaissance France. A specific type of clothed body emerged in 16th century France especially at Court. Clothing put its mark on the body, accentuating sexual dimorphism, imposing either Renaissance rectitude or distortions, transforming the body into a decorative surface for displaying magnificence. Its specificity resulted from the influence of various vestimentary and decorative fashions, starting with the new kinds of civility circulating in Renaissance Europe, which fashioned self-presentation. It found its fullest expression on the bodies of cosmopolitan aristocrats seeking a distinctive eloquence for their particular identity. At the same time, the identities which clothes imprinted on their wearer seemed threatened by transfers of vestimentary practices between sexes, sexual groups, and/or nations. The unease created by this mixture of appearances reflects that of

  2. Apparent diffusion coefficient and fractional anisotropy of newly diagnosed grade II gliomas.

    Science.gov (United States)

    Khayal, Inas S; McKnight, Tracy R; McGue, Colleen; Vandenberg, Scott; Lamborn, Kathleen R; Chang, Susan M; Cha, Soonmee; Nelson, Sarah J

    2009-05-01

    Distinguishing between low-grade oligodendrogliomas (ODs) and astrocytomas (AC) is of interest for defining prognosis and stratifying patients to specific treatment regimens. The purpose of this study was to determine if the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) from diffusion imaging can help to differentiate between newly diagnosed grade II OD and AC subtypes and to evaluate the ADC and FA values for the mixed population of oligoastrocytomas (OA). Fifty-three patients with newly diagnosed grade II gliomas were studied using a 1.5T whole body scanner (23 ODs, 16 ACs, and 14 OAs). The imaging protocol included post-gadolinium T1-weighted images, T2-weighted images, and either three and/or six directional diffusion imaging sequence with b = 1000 s/mm(2). Diffusion-weighted images were analyzed using in-house software to calculate maps of ADC and for six directional acquisitions, FA. The intensity values were normalized by values from normal appearing white matter (NAWM) to generate maps of normalized apparent diffusion coefficient (nADC) and normalized fractional anisotropy (nFA). The hyperintense region in the T2 weighted image was defined as the T2All region. A Mann-Whitney rank-sum test was performed on the 25th, median, and 75th nADC and nFA among the three subtypes. Logistic regression was performed to determine how well the nADC and nFA predict subtype. Lesions diagnosed as being OD had significantly lower nADC and significantly higher nFA, compared to AC. The nADC and nFA values individually classified the data with an accuracy of 87%. Combining the two did not enhance the classification. The patients with OA had nADC and nFA values between those of OD and AC. This suggests that ADC and FA may be helpful in directing tissue sampling to the most appropriate regions for taking biopsies in order to make a definitive diagnosis. PMID:19125391

  3. Apparent diffusion coefficient and fractional anisotropy of newly diagnosed grade II gliomas†

    Science.gov (United States)

    Khayal, Inas S.; McKnight, Tracy R.; McGue, Colleen; Vandenberg, Scott; Lamborn, Kathleen R.; Chang, Susan M.; Cha, Soonmee; Nelson, Sarah J.

    2013-01-01

    Distinguishing between low-grade oligodendrogliomas (ODs) and astrocytomas (AC) is of interest for defining prognosis and stratifying patients to specific treatment regimens. The purpose of this study was to determine if the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) from diffusion imaging can help to differentiate between newly diagnosed grade II OD and AC subtypes and to evaluate the ADC and FA values for the mixed population of oligoastrocytomas (OA). Fifty-three patients with newly diagnosed grade II gliomas were studied using a 1.5T whole body scanner (23 ODs, 16 ACs, and 14 OAs). The imaging protocol included post-gadolinium T1-weighted images, T2-weighted images, and either three and/or six directional diffusion imaging sequence with b = 1000 s/mm2. Diffusion-weighted images were analyzed using in-house software to calculate maps of ADC and for six directional acquisitions, FA. The intensity values were normalized by values from normal appearing white matter (NAWM) to generate maps of normalized apparent diffusion coefficient (nADC) and normalized fractional anisotropy (nFA). The hyperintense region in the T2 weighted image was defined as the T2All region. A Mann–Whitney rank-sum test was performed on the 25th, median, and 75th nADC and nFA among the three subtypes. Logistic regression was performed to determine how well the nADC and nFA predict subtype. Lesions diagnosed as being OD had significantly lower nADC and significantly higher nFA, compared to AC. The nADC and nFA values individually classified the data with an accuracy of 87%. Combining the two did not enhance the classification. The patients with OA had nADC and nFA values between those of OD and AC. This suggests that ADC and FA may be helpful in directing tissue sampling to the most appropriate regions for taking biopsies in order to make a definitive diagnosis. PMID:19125391

  4. Diagnostic value of apparent diffusion coefficient for the accurate assessment and differentiation of intracranial meningiomas

    International Nuclear Information System (INIS)

    Diffusion-weighted imaging (DWI) along with the calculation of apparent diffusion coefficient (ADC), is a novel, non-invasive, and reliable technique of choice for accurate assessment and for the treatment planning of different types of brain tumors. It is more advantageous in the distinction and differentiation of benign from malignant meningiomas on the basis of ADC values. To investigate the utility of DW magnetic resonance imaging (MRI), and to compare the apparent diffusion coefficient (ADC) obtained at two b-values for an authentic and preoperative characterization of meningiomas. Twenty-six patients with clinically diagnosed or histologically verified meningioma (18 benign and 8 malignant) underwent imaging including DWI at 1.5 T. DW images were obtained at b = 1000 s/mm2 and b = 2000 s/mm2, ADC maps were generated at both the b-values. Signal intensities (SIs) and ADCs for solid tumorous tissues, contralateral normal tissues, and peritumoral edema were calculated and normalized ADC (NADC) ratio were determined for tumorous tissues. SI scores, ADC maps, and ADC values were analyzed visually and quantitatively, and were compared at both the b-values. DW images at b = 2000 s/mm2 were more conspicuity (either hyperintense or hypointense) with improved contrast. The mean ADC of malignant meningiomas (0.64 ± 0.05 and 0.42 ± 0.03) was significantly lower (P < 0.05) as compared with benign meningiomas (1.04 ± 0.12 and 0.80 ± 0.07) at both the b-values. Mean NADC ratio in the malignant type was also significantly lower (P < 0.05) than the benign type at both the b-values. Mean ADC values for peritumoral edema do not differ between benign and malignant meningiomas. 1.5-T DWI using high b-values improved our ability to differentiate benign from malignant meningiomas. DWI may play an important role in the preoperative radiological evaluation and the recognition of these types for proper surgical treatment

  5. Cryptic organisation within an apparently irregular rostrocaudal distribution of interneurons in the embryonic zebrafish spinal cord

    International Nuclear Information System (INIS)

    The molecules and mechanisms involved in patterning the dorsoventral axis of the developing vertebrate spinal cord have been investigated extensively and many are well known. Conversely, knowledge of mechanisms patterning cellular distributions along the rostrocaudal axis is relatively more restricted. Much is known about the rostrocaudal distribution of motoneurons and spinal cord cells derived from neural crest but there is little known about the rostrocaudal patterning of most of the other spinal cord neurons. Here we report data from our analyses of the distribution of dorsal longitudinal ascending (DoLA) interneurons in the developing zebrafish spinal cord. We show that, although apparently distributed irregularly, these cells have cryptic organisation. We present a novel cell-labelling technique that reveals that DoLA interneurons migrate rostrally along the dorsal longitudinal fasciculus of the spinal cord during development. This cell-labelling strategy may be useful for in vivo analysis of factors controlling neuron migration in the central nervous system. Additionally, we show that DoLA interneurons persist in the developing spinal cord for longer than previously reported. These findings illustrate the need to investigate factors and mechanisms that determine 'irregular' patterns of cell distribution, particularly in the central nervous system but also in other tissues of developing embryos.

  6. Measurement depth effects on the apparent temperature sensitivity of soil respiration in field studies

    Directory of Open Access Journals (Sweden)

    A. Graf

    2008-05-01

    Full Text Available CO2 efflux at the soil surface is the result of respiration in different depths that are subjected to variable temperatures at the same time. Therefore, the temperature measurement depth affects the apparent temperature sensitivity of field-measured soil respiration. We summarize existing literature evidence on the importance of this effect, and describe a simple model to understand and estimate the magnitude of this potential error source for heterotrophic respiration. The model is tested against field measurements. We discuss the influence of climate (annual and daily temperature amplitude, soil properties (vertical distribution of CO2 sources, thermal and gas diffusivity, and measurement schedule (frequency, study duration, and time averaging. Q10 as a commonly used parameter describing the temperature sensitivity of soil respiration is taken as an example and computed for different combinations of the above conditions. We define conditions and data acquisition and analysis strategies that lead to lower errors in field-based Q10 determination. It was found that commonly used temperature measurement depths are likely to result in an underestimation of temperature sensitivity in field experiments. Our results also apply to activation energy as an alternative temperature sensitivity parameter.

  7. Measurement depth effects on the apparent temperature sensitivity of soil respiration in field studies

    Directory of Open Access Journals (Sweden)

    A. Graf

    2008-08-01

    Full Text Available CO2 efflux at the soil surface is the result of respiration in different depths that are subjected to variable temperatures at the same time. Therefore, the temperature measurement depth affects the apparent temperature sensitivity of field-measured soil respiration. We summarize existing literature evidence on the importance of this effect, and describe a simple model to understand and estimate the magnitude of this potential error source for heterotrophic respiration. The model is tested against field measurements. We discuss the influence of climate (annual and daily temperature amplitude, soil properties (vertical distribution of CO2 sources, thermal and gas diffusivity, and measurement schedule (frequency, study duration, and time averaging. Q10 as a commonly used parameter describing the temperature sensitivity of soil respiration is taken as an example and computed for different combinations of the above conditions. We define conditions and data acquisition and analysis strategies that lead to lower errors in field-based Q10 determination. It was found that commonly used temperature measurement depths are likely to result in an underestimation of temperature sensitivity in field experiments. Our results also apply to activation energy as an alternative temperature sensitivity parameter.

  8. On the Apparent Nulls and Extreme Variability of PSR J1107-5907

    CERN Document Server

    Young, N J; Stappers, B W; Lyne, A G; Kramer, M

    2014-01-01

    We present an analysis of the emission behaviour of PSR J1107-5907, a source known to exhibit separate modes of emission, using observations obtained over approximately 10 yr. We find that the object exhibits two distinct modes of emission; a strong mode with a broad profile and a weak mode with a narrow profile. During the strong mode of emission, the pulsar typically radiates very energetic emission over sequences of ~200-6000 pulses (~60 s-24 min), with apparent nulls over time-scales of up to a few pulses at a time. Emission during the weak mode is observed outside of these strong-mode sequences and manifests as occasional bursts of up to a few clearly detectable pulses at a time, as well as low-level underlying emission which is only detected through profile integration. This implies that the previously described null mode may in fact be representative of the bottom-end of the pulse intensity distribution for the source. This is supported by the dramatic pulse-to-pulse intensity modulation and rarity of ...

  9. Cryptic organisation within an apparently irregular rostrocaudal distribution of interneurons in the embryonic zebrafish spinal cord

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Simon, E-mail: simon.wells@adelaide.edu.au [Discipline of Genetics, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia 5005 (Australia); The Special Research Centre for the Molecular Genetics of Development, University of Adelaide, Adelaide, South Australia 5005 (Australia); Conran, John G., E-mail: john.conran@adelaide.edu.au [Ecology and Evolutionary Biology, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia 5005 (Australia); Tamme, Richard, E-mail: rtamme@ttu.ee [Discipline of Genetics, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia 5005 (Australia); Gaudin, Arnaud, E-mail: a.gaudin@uq.edu.au [School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072 (Australia); Webb, Jonathan, E-mail: jonathan.webb@worc.ox.ac.uk [Discipline of Genetics, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia 5005 (Australia); Lardelli, Michael, E-mail: michael.lardelli@adelaide.edu.au [Discipline of Genetics, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia 5005 (Australia); The Special Research Centre for the Molecular Genetics of Development, University of Adelaide, Adelaide, South Australia 5005 (Australia)

    2010-11-15

    The molecules and mechanisms involved in patterning the dorsoventral axis of the developing vertebrate spinal cord have been investigated extensively and many are well known. Conversely, knowledge of mechanisms patterning cellular distributions along the rostrocaudal axis is relatively more restricted. Much is known about the rostrocaudal distribution of motoneurons and spinal cord cells derived from neural crest but there is little known about the rostrocaudal patterning of most of the other spinal cord neurons. Here we report data from our analyses of the distribution of dorsal longitudinal ascending (DoLA) interneurons in the developing zebrafish spinal cord. We show that, although apparently distributed irregularly, these cells have cryptic organisation. We present a novel cell-labelling technique that reveals that DoLA interneurons migrate rostrally along the dorsal longitudinal fasciculus of the spinal cord during development. This cell-labelling strategy may be useful for in vivo analysis of factors controlling neuron migration in the central nervous system. Additionally, we show that DoLA interneurons persist in the developing spinal cord for longer than previously reported. These findings illustrate the need to investigate factors and mechanisms that determine 'irregular' patterns of cell distribution, particularly in the central nervous system but also in other tissues of developing embryos.

  10. Relationship between Rice Yield and Apparent Electrical Conductivity of Paddy Soils

    Directory of Open Access Journals (Sweden)

    M. H. Ezrin

    2010-01-01

    Full Text Available Problem statement: Understanding the relationships between rice yield and soil properties such as bulk electrical conductivity is of critical importance in precision farming. The apparent Electrical Conductivity of soil (ECa is influenced by a combination of physico-chemical properties including soluble salts, clay content and mineralogy, soil water content, bulk density, organic matter and soil temperature. Accordingly, ECa is considered as the most reliable and frequently used tools in precision farming research for the spatio-temporal characterization of edaphic and anthropogenic properties that influence crop yield. Many researchers have found positive correlation of ECa to crop yield such as corn and soy bean but not rice paddies. This study discussed on the relationship between ECa and rice yield for best practice management on paddy field. Approach: The analyses had used two reliable methods in six selected paddy lots at Sawah Sempadan, Selangor, Malaysia. Stepwise Linear Regression (SLR and Boundary Line Analysis (BLA techniques were used. External factors such as weather conditions, disease outbreaks, labor shortage and other factors were not considered in the data analysis and interpretation. Results: The results indicate that deep ECa (ECad is significantly related to rice yield with R2 = 0.1246 and R2 = 0.4156 from SLR and BLA analyses, respectively. Conclusion: Results of this study can benefit farmers and researchers to understand the influence of ECa to the crop productivity.

  11. The use of MRI apparent diffusion coefficient (ADC in monitoring the development of brain infarction

    Directory of Open Access Journals (Sweden)

    Yuan Jian-Jun

    2011-01-01

    Full Text Available Abstract Background To study the rules that apparent diffusion coefficient (ADC changes with time and space in cerebral infarction, and to provide the evidence in defining the infarction stages. Methods 117 work-ups in 98 patients with cerebral infarction (12 hyperacute, 43 acute, 29 subacute, 10 steady, and 23 chronic infarctions were imaged with both conventional MRI and diffusion weighted imaging. The average ADC values, the relative ADC (rADC values, and the ADC values or rADC values from the center to the periphery of the lesion were calculated. Results The average ADC values and the rADC values of hyperacute and acute infarction lesion depressed obviously. rADC values in hyperacute and acute stage was minimized, and increased progressively as time passed and appeared as "pseudonormal" values in approximately 8 to 14 days. Thereafter, rADC values became greater than normal in chronic stage. There was positive correlation between rADC values and time (P Conclusion The ADC values of infarction lesions have evolution rules with time and space. The evolution rules with time and those in space can be helpful to decide the clinical stage, and to provide the evidence in guiding the treatment or judging the prognosis in infarction.

  12. Dietary patterns and changes in cardiovascular risk factors in apparently healthy Chinese women: a longitudinal study

    Science.gov (United States)

    Li, Ping; Zhang, Meilin; Zhu, Yufeng; Liu, Weiqiao; Zhang, Yuwen; Gao, Yuxia; Huang, Guowei

    2016-01-01

    Little is known of the relationships between dietary patterns and cardiovascular risk factors in China. We therefore designed a 3-year longitudinal study to evaluate the impacts of dietary patterns on changes in these factors among Chinese women. A total of 1,028 subjects who received health examination in 2011 and 2014 were recruited. Three major dietary patterns (“vegetable pattern”, “meat pattern”, and “animal offal-dessert-and-alcohol pattern”) were derived by principal component analysis based on validated food frequency questionnaires. Cardiovascular risk factors were standardized to create within-cohort z-scores and the changes in them were calculated as the differences between 2011 and 2014. Relationships between dietary patterns and changes in cardiovascular risk factors were assessed using general linear model. After adjustment for potential confounders, changes in total cholesterol and fasting blood glucose decreased across the tertiles of vegetable pattern (p for trend = 0.01 and 0.04, respectively). While, changes in diastolic blood pressure, total cholesterol and low density lipoprotein cholesterol increased across the tertiles of animal offal-dessert-and-alcohol pattern (p for trend = 0.02, 0.01, and 0.02, respectively). The findings suggest that vegetable pattern was beneficially related to cardiovascular risk factors, whereas animal offal-dessert-and-alcohol pattern was detrimental related to these factors among apparently healthy Chinese women. PMID:27257349

  13. Mesquite pod meal in sheep diet: intake, apparent digestibility of nutrients and nitrogen balance

    Directory of Open Access Journals (Sweden)

    Edileusa de Jesus do Santos

    2015-02-01

    Full Text Available Eight Santa Ines sheep were assigned to two 4 x 4 Latin squares, to evaluate the effects of replacing elephant grass silage with different levels of mesquite pod meal (MDM (15, 30 and 45% DM on intake, apparent digestibility of dry matter (DM, organic matter (OM, crude protein (CP, ether extract (EE, acid detergent fiber (ADF, neutral detergent fiber (NDF, total carbohydrates (TC and non-fiber carbohydrates (NFC and the nitrogen balance. There was a linear increase (p < 0.05 in the intake of DM, OM, CP, ADF, NDF, NFC and TC according to the addition of MPM to the diet. The digestibility of DM, OM and CP increased (p < 0.05 with the addition of MDM. We observed a positive linear effect (p < 0.05 for the nitrogen intake. The addition of mesquite pod meal up to 45% increased the intake of DM, NDF, ADF, CP, OM, NFC and TC but reduced the digestibility of EE and NDF. MPM at 30 and 45% propitiated a positive nitrogen balance.

  14. Apparent diffusion coefficient in cervical cancer of the uterus: comparison with the normal uterine cervix

    Energy Technology Data Exchange (ETDEWEB)

    Naganawa, Shinji; Sato, Chiho; Ishigaki, Takeo [Nagoya University School of Medicine, Department of Radiology, Nagoya (Japan); Kumada, Hisashi; Miura, Shunichi [Toyohashi Municipal hospital, Department of Radiology, Toyohashi, Aich (Japan); Takizawa, Osamu [Siemens-Asahi Medical Technologies Ltd, Tokyo (Japan)

    2005-01-01

    A relation between apparent diffusion coefficient (ADC) values and tumor cellular density has been reported. The purpose of this study was to measure the ADC values of cervical cancers in the uterus and compare them with those of normal cervical tissues, and to test whether ADC could differentiate between normal and malignant cervical tissues in the uterus. Twelve consecutive female patients with cervical cancer of the uterus and ten female patients with other pelvic abnormalities were included in this study. ADC was measured at 1.5 T with b-factors of 0, 300 and 600 s/mm{sup 2} using single-shot echo-planar diffusion-weighted imaging and a parallel imaging technique. The mean ADC value of cervical cancer lesions was 1.09{+-}0.20 x 10{sup -3} mm{sup 2}/s, and that of normal cervix tissue was 1.79{+-}0.24 x 10{sup -3} mm{sup 2}/s (P<0.0001). In nine patients treated by chemotherapy and/or radiation therapy, the mean ADC value of the cervical cancer lesion increased significantly after therapy (P<0.001). The present study showed, with a small number of patients, that ADC measurement has a potential ability to differentiate between normal and cancerous tissue in the uterine cervix. Further study is necessary to determine the accuracy of ADC measurement in monitoring the treatment response. (orig.)

  15. Biosynthesis of Xanthan Gum from Fermenting Shrimp Shell: Yield and Apparent Viscosity

    Directory of Open Access Journals (Sweden)

    Larissa Alves de Sousa Costa

    2014-01-01

    Full Text Available With the aim of producing xanthan gum, the effects of an aqueous shrimp shell extract (SSAE as the source of carbon and nitrogen on the yield and apparent viscosity of the gums produced by fermentation using three native strains of Xanthomonas campestris were studied. It was found that the SSAE contained 89.75% moisture, 0.054% ash, 8.069% protein, 0.787 lipids, and 1.337% carbohydrates. Media containing different concentrations of SSAE and supplemented with urea (0.01% and phosphate (0.1% were fermented in a shaker, and the results obtained were compared with those obtained from sucrose (control with the same supplementation and fermentation conditions. Strain 1182 showed the highest yield (4.64 g·L−1 and viscosity (48.53 mPa·s, from the medium containing 10% (w/v of SSAE. These values were higher than those obtained from the control medium containing sucrose. Shrimp shell is a low cost residue that can be bioconverted into products of high added value such as xanthan gum.

  16. Regional apparent diffusion coefficient values in 3rd trimester fetal brain

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Chen [Tel Aviv University, Department of Radiology, Sheba Medical Center, Tel Hashomer (affiliated to the Sackler School of Medicine), Tel Aviv (Israel); Sheba Medical Center, Diagnostic Imaging, 52621, Tel Hashomer (Israel); Weisz, Boaz; Lipitz, Shlomo; Katorza, Eldad [Tel Aviv University, Department of Obstetrics and Gynecology, Sheba Medical Center, Tel Hashomer (affiliated to the Sackler School of Medicine), Tel Aviv (Israel); Yaniv, Gal; Bergman, Dafi [Tel Aviv University, Department of Radiology, Sheba Medical Center, Tel Hashomer (affiliated to the Sackler School of Medicine), Tel Aviv (Israel); Biegon, Anat [Stony Brook University School of Medicine, Department of Neurology, Stony Brook, NY (United States)

    2014-07-15

    Apparent diffusion coefficient (ADC) values in the developing fetus can be used in the diagnosis and prognosis of prenatal brain pathologies. To this end, we measured regional ADC in a relatively large cohort of normal fetal brains in utero. Diffusion-weighted imaging (DWI) was performed in 48 non-sedated 3rd trimester fetuses with normal structural MR imaging results. ADC was measured in white matter (frontal, parietal, temporal, and occipital lobes), basal ganglia, thalamus, pons, and cerebellum. Regional ADC values were compared by one-way ANOVA with gestational age as covariate. Regression analysis was used to examine gestational age-related changes in regional ADC. Four other cases of CMV infection were also examined. Median gestational age was 32 weeks (range, 26-33 weeks). There was a highly significant effect of region on ADC, whereby ADC values were highest in white matter, with significantly lower values in basal ganglia and cerebellum and the lowest values in thalamus and pons. ADC did not significantly change with gestational age in any of the regions tested. In the four cases with fetal CMV infection, ADC value was associated with a global decrease. ADC values in normal fetal brain are relatively stable during the third trimester, show consistent regional variation, and can make an important contribution to the early diagnosis and possibly prognosis of fetal brain pathologies. (orig.)

  17. Percentage of apparent sucrose and productive potential of sugar in cane cultivars

    Directory of Open Access Journals (Sweden)

    Hélio Francisco Da Silva Neto

    2014-03-01

    Full Text Available The percentage of saccharose apparent "POL" is an important variable for the determination of sugar production, and its value differs among the cultivars, plant parts and growth seasons. The study aimed to compare values of POL and estimate productive potential of sugar in juice extracted from nodes and internodes of the sugarcane cultivars sugar during the 2010/2011 crop season. We used the experimental design of randomized blocks in factorial scheme 3x2x6, with four replications. The main treatments were cultivars of sugarcane, the secondary treatments two parts of the stalks of sugarcane, and third the seasons of analysis distributed over the harvest. The cultivars RB72454 and SP81-3250 showed the highest values POL. Conversely, the RB867515 obtained less satisfactory results, showing lower value of POL throughout the study period, and the two parts of the stalk. The internode was greater than POL, and showed greater potential for sugar production when compared to the stalk portion represented by the node. The values of POL and the productive potential of sugar, obtained by both sides of the stalk were growing throughout the season, and coincided with the harvest season recommended for these cultivars. However, there was this period that the biggest difference between the parts of the stalk, indicating the need for a better use of the internode.

  18. Considerations on the quantitative analysis of apparent amorphicity of milled lactose by Raman spectroscopy.

    Science.gov (United States)

    Pazesh, Samaneh; Lazorova, Lucia; Berggren, Jonas; Alderborn, Göran; Gråsjö, Johan

    2016-09-10

    The main purpose of the study was to evaluate various pre-processing and quantification approaches of Raman spectrum to quantify low level of amorphous content in milled lactose powder. To improve the quantification analysis, several spectral pre-processing methods were used to adjust background effects. The effects of spectral noise on the variation of determined amorphous content were also investigated theoretically by propagation of error analysis and were compared to the experimentally obtained values. Additionally, the applicability of calibration method with crystalline or amorphous domains in the estimation of amorphous content in milled lactose powder was discussed. Two straight baseline pre-processing methods gave the best and almost equal performance. By the succeeding quantification methods, PCA performed best, although the classical least square analysis (CLS) gave comparable results, while peak parameter analysis displayed to be inferior. The standard deviations of experimental determined percentage amorphous content were 0.94% and 0.25% for pure crystalline and pure amorphous samples respectively, which was very close to the standard deviation values from propagated spectral noise. The reasonable conformity between the milled samples spectra and synthesized spectra indicated representativeness of physical mixtures with crystalline or amorphous domains in the estimation of apparent amorphous content in milled lactose. PMID:27397869

  19. A statistical representation of the cosmological constant from finite size effects at the apparent horizon

    Science.gov (United States)

    Viaggiu, Stefano

    2016-07-01

    In this paper we present a statistical description of the cosmological constant in terms of massless bosons (gravitons). To this purpose, we use our recent results implying a non vanishing temperature {T_{Λ }} for the cosmological constant. In particular, we found that a non vanishing T_{Λ } allows us to depict the cosmological constant Λ as composed of elementary oscillations of massless bosons of energy hbar ω by means of the Bose-Einstein distribution. In this context, as happens for photons in a medium, the effective phase velocity v_g of these massless excitations is not given by the speed of light c but it is suppressed by a factor depending on the number of quanta present in the universe at the apparent horizon. We found interesting formulas relating the cosmological constant, the number of quanta N and the mean value overline{λ } of the wavelength of the gravitons. In this context, we study the possibility to look to the gravitons system so obtained as being very near to be a Bose-Einstein condensate. Finally, an attempt is done to write down the Friedmann flat equations in terms of N and overline{λ }.

  20. Invasive orbital aspergillosis in an apparently immunocompetent host without evidence of sinusitis

    Directory of Open Access Journals (Sweden)

    Jennifer Primeggia

    2012-09-01

    Full Text Available Invasive aspergillosis is uncommon in healthy individuals. We report a case of Aspergillus fumigatus orbital cellulitiswith intracranial extension in an apparently immunocompetent patient with a history of benign lymphoid hyperplasiaof the lacrimal gland. A 68 year-old man with no significant past medical history underwent orbitotomy and biopsy of alacrimal gland mass. Pathology showed benign lymphoid hyperplasia of the lacrimal gland and he completed radiationtherapy. Three months after orbitotomy and one month after completion of radiation therapy, he presented with orbitalcellulitis. Brain magnetic resonance imaging demonstrated invasion into the frontal lobe. Clinical and radiographicfindings failed to improve with prolonged antibiotic therapy; transcranial orbitotomy with right frontal craniotomy forabscess drainage and orbit washout was performed. Intraoperative cultures grew Aspergillus fumigatus. The patientcompleted a six month course of therapy with oral voriconazole and has remained free from relapse with long-termfollow-up. Efficacy of voriconazole was guided by serial imaging and voriconazole trough levels. Aspergillus may causeinvasive disease in immunocompetent hosts, even without evidence of sinusitis, and should be considered in the differentialdiagnosis when patients do not demonstrate clinical improvement with antibiotic therapy. J Microbiol Infect Dis2012; 2(3: 113-116Key words: Aspergillosis, orbital cellulitis, brain abscess

  1. Impact of an apparent radiation embrittlement rate on the life expectancy of PWR vessel supports

    International Nuclear Information System (INIS)

    Recent data from the High Flux Isotope Reactor (HFIR) vessel surveillance program indicate a substantial radiation embrittlement rate effect at low irradiation temperatures (∼50 degrees C) for A212-B, A350-LF3, A105-II, and corresponding welds. Some pressurized-water-reactor (PWR) vessel supports are fabricated of similar materials and are subjected to the same low temperatures and fast neutron fluxes (108 to 109 neutrons cm-2 s-1, E > 1.0 MeV) as those in the HFIR vessel. Thus the embrittlement rate of these structures may be greater than that previously anticipated. A study sponsored by the Nuclear Regulatory Commission is under way at Oak Ridge National Laboratory to determine the impact of the rate effect on PWR vessel support life expectancy. The scope includes the interpretation and application of the HFIR data, a survey of all light-water-reactor vessel support designs, and a structural and fracture-mechanics analysis of the supports for two specific PWR plants of particular interest with regard to a potential for support failure as a result of propagation of flaws. Calculations performed for one of the plants indicate a best-estimate critical flaw size of approximately 10 mm corresponding to 32 effective full-power years. Apparently low-cycle fatigue is not a viable mechanism for the creation of flaws of this size. Thus, presumably, such flaws would have to exist at the time of fabrication

  2. The Real, the Apparent, and What is eigentlich

    Directory of Open Access Journals (Sweden)

    Regine Eckardt

    2009-01-01

    Full Text Available In this paper, I will propose a uniform analysis for adjectival and certain instances of adverbial eigentlich. The analysis rests on the assumption that eigentlich contrasts the nominal content of a concept C with a contextually given notion of phenomenological evidence for C-hood. eigentlich offers the semantic frame to refer to two ways of C-hood which are usually supplied by context. In the adjectival use, the discourse content should provide an N exemplar in the true sense (an eigentliches N along with an apparent N, thereby proving the two notions to be different. In the adverbial use, the message conveyed is usually that the actual world nominally satisfies some proposition p (eigentlich, p while the actual world looks as if a contrasting proposition q were the case. The analysis improves on earlier accounts in German descriptive linguistics in that it offers a fully compositional account of the semantic and pragmatic contribution of eigentlich in a wide variety of constructions, including focus, contrastive topic and questions. The analysis proposes a delineation of eigentlich as an emotive marker which differs from the content use in prosody, syntax, focus sensitivity and meaning.

  3. SIMSISH technique does not alter the apparent isotopic composition of bacterial cells.

    Directory of Open Access Journals (Sweden)

    Olivier Chapleur

    Full Text Available In order to identify the function of uncultured microorganisms in their environment, the SIMSISH method, combining in situ hybridization (ISH and nanoscale secondary ion mass spectrometry (nanoSIMS imaging, has been proposed to determine the quantitative uptake of specific labelled substrates by uncultured microbes at the single cell level. This technique requires the hybridization of rRNA targeted halogenated DNA probes on fixed and permeabilized microorganisms. Exogenous atoms are introduced into cells and endogenous atoms removed during the experimental procedures. Consequently differences between the original and the apparent isotopic composition of cells may occur. In the present study, the influence of the experimental procedures of SIMSISH on the isotopic composition of carbon in E. coli cells was evaluated with nanoSIMS and compared to elemental analyser-isotopic ratio mass spectrometer (EA-IRMS measurements. Our results show that fixation and hybridization have a very limited, reproducible and homogeneous influence on the isotopic composition of cells. Thereby, the SIMSISH procedure minimizes the contamination of the sample by exogenous atoms, thus providing a means to detect the phylogenetic identity and to measure precisely the carbon isotopic composition at the single cell level. This technique was successfully applied to a complex sample with double bromine - iodine labelling targeting a large group of bacteria and a specific archaea to evaluate their specific (13C uptake during labelled methanol anaerobic degradation.

  4. System III variations in apparent distance of Io plasma torus from Jupiter

    Science.gov (United States)

    Dessler, A. J.; Sandel, B. R.

    1992-01-01

    System III variations in apparent distance of the Io plasma torus from Jupiter are examined on the basis of data obtained from UVS scans across Jupiter's satellite system. The displacement of the dawn and dusk ansae are found to be unexpectedly complex. The displacements are unequal and both ansae are in motion with the motion of the approaching ansa being the lesser of the two. The radial motions, as measured from either the center of Jupiter or the offset-tilted dipole, are of unequal magnitude and have the System III periodicity. It is concluded that the cross-tail electric field that causes these torus motions is concentrated on the dusk ansa, varied with the System III period, and shows magnetic-anomaly phase control. It is found that the dawn-dust asymmetry in brightness is not explained simply by the cross-tail electric field. It is concluded that there is a heating mechanism that causes the dusk side of the Io plasma torus to be brighter than the dawn side.

  5. A Fast Apparent-Horizon Finder for 3-Dimensional Cartesian Grids in Numerical Relativity

    CERN Document Server

    Thornburg, J

    2004-01-01

    In 3+1 numerical simulations of dynamic black hole spacetimes, it's useful to be able to find the apparent horizon(s) (AH) in each slice of a time evolution. A number of AH finders are available, but they often take many minutes to run, so they're too slow to be practically usable at each time step. Here I present a new AH finder,_AHFinderDirect_, which is very fast and accurate, typically taking only a few seconds to find an AH to $sim 10^{-5} m$ accuracy on a GHz-class processor. I assume that an AH to be searched for is a Strahlk"orper (star-shaped region) with respect to some local origin, and so parameterize the AH shape by $r = h(angle)$ for some single-valued function $h: S^2 to Re^+$. The AH equation then becomes a nonlinear elliptic PDE in $h$ on $S^2$, whose coefficients are algebraic functions of $g_{ij}$, $K_{ij}$, and the Cartesian-coordinate spatial derivatives of $g_{ij}$. I discretize $S^2$ using 6 angular patches (one each in the neighborhood of the $pm x$, $pm y$, and $pm z$ axes) to avoid c...

  6. [Apparent life-threatening events and sudden unexpected death in infancy: Two different entities].

    Science.gov (United States)

    Naud, J

    2015-09-01

    Most infant apparent life-threatening events (ALTEs) are minor with spontaneously favorable prognosis. Frequent etiologies are gastroesophageal reflux, obstructive apneas, respiratory infections, and breath-holding spells. Some rare but potentially serious causes must be discussed. Diagnosis is usually guided by careful questioning of the parents and repeated clinical examinations. A few complementary examinations are systematically needed and their performance is increased if they are oriented by clinical aspects. Hospitalization is usual for monitoring, further etiological investigation, and management of parental anxiety. ALTE and sudden unexpected death in infancy (SUDI) etiologies are often different. SUDI is called sudden unexplained death in infancy if it remains unexplained after investigation including autopsy. The annual incidence in France fell sharply after prevention campaigns in the 1990s, and now is about 400 SUDI, including 250 unexplained SUDI. The main guidelines of prevention are back sleeping, cessation of smoking during and after pregnancy, securing the bed and bedding, prevention of hyperthermia, and avoidance of dangerous factors of bed sharing. In the future, infants with particular vulnerabilities may be identified. The Haute Autorité de santé (French National Authority for Health) has published guidelines to support SUDI, standardize procedures, and improve our understanding of the causes of death. PMID:26228810

  7. Reconstruction of apparent orthotropic conductivity tensor image using magnetic resonance electrical impedance tomography

    International Nuclear Information System (INIS)

    Magnetic resonance electrical impedance tomography visualizes current density and/or conductivity distributions inside an electrically conductive object. Injecting currents into the imaging object along at least two different directions, induced magnetic flux density data can be measured using a magnetic resonance imaging scanner. Without rotating the object inside the scanner, we can measure only one component of the magnetic flux density denoted as Bz. Since the biological tissues such as skeletal muscle and brain white matter show strong anisotropic properties, the reconstruction of anisotropic conductivity tensor is indispensable for the accurate observations in the biological systems. In this paper, we propose a direct method to reconstruct an axial apparent orthotropic conductivity tensor by using multiple Bz data subject to multiple injection currents. To investigate the anisotropic conductivity properties, we first recover the internal current density from the measured Bz data. From the recovered internal current density and the curl-free condition of the electric field, we derive an over-determined matrix system for determining the internal absolute orthotropic conductivity tensor. The over-determined matrix system is designed to use a combination of two loops around each pixel. Numerical simulations and phantom experimental results demonstrate that the proposed algorithm stably determines the orthotropic conductivity tensor

  8. Detection of Yersinia spp and Salmonella spp. in apparently healthy cats and dogs in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    shabnam hashemi

    2016-03-01

    Full Text Available Introduction: Companion animals, such as cat and dog, are potential sources of transmissible diseases to humans, especially children. They harbor zoonotic agents in gastrointestinal tracts as carriers which are capable of infecting their owners. Salmonella and Yersinia bacteria are considered as frequent causes of illness in children. This study was aimed at finding out the prevalence rate of infection in apparently healthy dogs and cats in Tehran, Iran. Materials and methods: A total of 100 rectal swabs from dogs and cats were analyzed by a multiplex PCR method with specific primers for detection of Yersinia and Salmonella species. Results: Fifteen samples (4 cats and 11 dogs were positive for Yersinia and 20 samples (9 cats and 11 dogs were positive for Salmonella. So the prevalence rate of Yersinia was 8% in cats and 22% in dogs and the prevalence rates of Salmonella were 18 and 22% in cats and dogs respectively. Discussion and conclusion: According to the results, Yersinia and Salmonella were detected in 8- 22% of pet animals without any clinical signs. The contaminated animal foods may be the main source of infection. These results may be useful in planning control and preventive programs. 

  9. A statistical representation of the cosmological constant from finite size effects at the apparent horizon

    CERN Document Server

    Viaggiu, Stefano

    2016-01-01

    In this paper we present a statistical description of the cosmological constant in terms of massless bosons (gravitons). To this purpose, we use our recent results implying a non vanishing temperature ${T_{\\Lambda}}$ for the cosmological constant. In particular, we found that a non vanishing $T_{\\Lambda}$ allows us to depict the cosmological constant $\\Lambda$ as composed of elementary oscillations of massless bosons of energy $\\hbar\\omega$ by means of the Bose-Einstein distribution. In this context, as happens for photons in a medium, the effective phase velocity $v_g$ of these massless excitations is not given by the speed of light $c$ but it is suppressed by a factor depending on the number of quanta present in the universe at the apparent horizon. We found interesting formulas relating the cosmological constant, the number of quanta $N$ and the mean value $\\overline{\\lambda}$ of the wavelength of the gravitons. In this context, we study the possibility to look to the gravitons system so obtained as being ...

  10. Evidence of deterministic components in the apparent randomness of GRBs: clues of a chaotic dynamic.

    Science.gov (United States)

    Greco, G; Rosa, R; Beskin, G; Karpov, S; Romano, L; Guarnieri, A; Bartolini, C; Bedogni, R

    2011-01-01

    Prompt γ-ray emissions from gamma-ray bursts (GRBs) exhibit a vast range of extremely complex temporal structures with a typical variability time-scale significantly short - as fast as milliseconds. This work aims to investigate the apparent randomness of the GRB time profiles making extensive use of nonlinear techniques combining the advanced spectral method of the Singular Spectrum Analysis (SSA) with the classical tools provided by the Chaos Theory. Despite their morphological complexity, we detect evidence of a non stochastic short-term variability during the overall burst duration - seemingly consistent with a chaotic behavior. The phase space portrait of such variability shows the existence of a well-defined strange attractor underlying the erratic prompt emission structures. This scenario can shed new light on the ultra-relativistic processes believed to take place in GRB explosions and usually associated with the birth of a fast-spinning magnetar or accretion of matter onto a newly formed black hole. PMID:22355609

  11. Apparent dynamic contact angle of an advancing gas--liquid meniscus

    International Nuclear Information System (INIS)

    The steady motion of an advancing meniscus in a gas-filled capillary tube involves a delicate balance of capillary, viscous, and intermolecular forces. The limit of small capillary numbers Ca (dimensionless speeds) is analyzed here with a matched asymptotic analysis that links the outer capillary region to the precursor film in front of the meniscus through a lubricating film. The meniscus shape in the outer region is constructed and the apparent dynamic contact angle Θ that the meniscus forms with the solid surface is derived as a function of the capillary number, the capillary radius, and the Hamaker's constant for intermolecular forces, under conditions of weak gas--solid interaction, which lead to fast spreading of the precursor film and weak intermolecular forces relative to viscous forces within the lubricating film. The dependence on intermolecular forces is very weak and the contact angle expression has a tight upper bound tan Θ=7.48 Ca1/3 for thick films, which is independent of the Hamaker constant. This upper bound is in very good agreement with existing experimental data for wetting fluids in any capillary and for partially wetting fluids in a prewetted capillary. Significant correction to the Ca1/3 dependence occurs only at very low Ca, where the intermolecular forces become more important and tan Θ diverges slightly from the above asymptotic behavior toward lower values

  12. Apparent \\oiii variability in the narrow line Seyfert I Mrk142

    CERN Document Server

    Zhang, XueGuang

    2015-01-01

    In this letter, we checked spectral properties of the well-known narrow line Seyfert I Mrk142, in order to try to find effects of narrow line variability on BLR radius of Mrk142 which is an outlier in the R-L plane. Although, no improvement can be found on BLR radius, apparent narrow line variability can be confirmed in Mrk142. Using the public spectra collected from the Lick AGN Monitoring Project, the spectral scaling method based on assumption of constant \\oiii line is firstly checked by examining broad and narrow emission line properties. We find that with the application of the spectral scaling method, there is a strong correlation between the \\oiii line flux and the \\oiii line width, but weaker correlations between the broad H$\\alpha$ flux and the broad H$\\beta$ flux, and between the broad H$\\alpha$ flux and the continuum emission at 5100\\AA. The results indicate that the assumption of constant \\oiii line is not preferred, and caution should be exercised when applying the spectral scaling calibration me...

  13. Reconstruction of apparent orthotropic conductivity tensor image using magnetic resonance electrical impedance tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sajib, Saurav Z. K.; Kim, Ji Eun; Jeong, Woo Chul; Kim, Hyung Joong; Woo, Eung Je [Department of Biomedical Engineering, Kyung Hee University, Yongin, Gyeonggi (Korea, Republic of); Kwon, Oh In, E-mail: oikwon@konkuk.ac.kr [Department of Mathematics, Konkuk University, Seoul (Korea, Republic of)

    2015-03-14

    Magnetic resonance electrical impedance tomography visualizes current density and/or conductivity distributions inside an electrically conductive object. Injecting currents into the imaging object along at least two different directions, induced magnetic flux density data can be measured using a magnetic resonance imaging scanner. Without rotating the object inside the scanner, we can measure only one component of the magnetic flux density denoted as B{sub z}. Since the biological tissues such as skeletal muscle and brain white matter show strong anisotropic properties, the reconstruction of anisotropic conductivity tensor is indispensable for the accurate observations in the biological systems. In this paper, we propose a direct method to reconstruct an axial apparent orthotropic conductivity tensor by using multiple B{sub z} data subject to multiple injection currents. To investigate the anisotropic conductivity properties, we first recover the internal current density from the measured B{sub z} data. From the recovered internal current density and the curl-free condition of the electric field, we derive an over-determined matrix system for determining the internal absolute orthotropic conductivity tensor. The over-determined matrix system is designed to use a combination of two loops around each pixel. Numerical simulations and phantom experimental results demonstrate that the proposed algorithm stably determines the orthotropic conductivity tensor.

  14. Small Scale Spatial Variability of Apparent Electrical Conductivity within a Paddy Field

    International Nuclear Information System (INIS)

    Quick variability description is an important component for zone management practices. Precision farming requires topping up of only the nutrients that are lacking in the soil to attain the highest yield with the least input. The apparent soil electrical conductivity (ECa) sensor is a useful tool in mapping to identify areas of contrasting soil properties. In non saline soils, ECa is a substitute measurement for soil texture. It is directly related to both water holding capacity and Cation Exchange Capacity (CEC), which are key ingredients of productivity. This sensor measures the ECa across a field quickly and gives detailed soil features (one-second interval) with few operators. Hence, a dense sampling is possible and therefore a high-resolution ECa map can be produced. This study aims to characterize the variability of soil ECa within a Malaysian paddy field with respect to the spatial and seasonal variability. The study was conducted at Block C, Sawah Sempadan, Selangor, Malaysia, for three continuous seasons. Soil ECa was collected after harvesting period. The results showed that deep ECa visualized the pattern of the former river routes clearly as continuous lines (about 45 m width) at the northern and central regions of the study area. This exploration has shown different maps with higher contrast as compared to the existing soil series map for the study area. Seasonal variability test showed that the ECa that was acquired during rainy season (collected after harvest in December to January) has the highest value as compared to another season.

  15. Diversity and complexity complement apparent competition: Nematode assemblages in banana plantations

    Science.gov (United States)

    Ferris, Howard; Pocasangre, Luis E.; Serrano, Edgardo; Muñoz, Jorge; Garcia, Socorro; Perichi, Guillermo; Martinez, Gustavo

    2012-04-01

    The structure of communities of soil organisms, and, therefore, their ecosystem functions, respond to spatial and temporal changes in plant diversity and to subsidies of organic matter. We introduce the concept of amplifiable and target prey in directing the impact of shared predators on pest organisms. In soil nematode assemblages, rather than overt apparent competition between the two prey categories, the effects were more subtle and expressed as increased predation pressure on the target prey when resources for the amplifiable prey were greater. We conclude that the connectance complexity of the food web subverts resource flow through a sequential chain of trophic interactions so that interaction strength decreases at successive trophic exchange. However, the effect of resource diversion is that the net regulatory pressure on the target prey is potentially enhanced by the increase in alternate predators of each prey category. The system requires that certain criteria are met, including that predator populations are resource limited, that conditions are conducive for predator survival and increase, and that predators, amplifiable and target prey are co-located in a majority of patches associated with resource subsidy, favorable conditions or migration patterns.

  16. Apparent motion from outside the visual field, retinotopic cortices may register extra-retinal positions.

    Directory of Open Access Journals (Sweden)

    Martin Szinte

    Full Text Available Observers made a saccade between two fixation markers while a probe was flashed sequentially at two locations on a side screen. The first probe was presented in the far periphery just within the observer's visual field. This target was extinguished and the observers made a large saccade away from the probe, which would have left it far outside the visual field if it had still been present. The second probe was then presented, displaced from the first in the same direction as the eye movement and by about the same distance as the saccade step. Because both eyes and probes shifted by similar amounts, there was little or no shift between the first and second probe positions on the retina. Nevertheless, subjects reported seeing motion corresponding to the spatial displacement not the retinal displacement. When the second probe was presented, the effective location of the first probe lay outside the visual field demonstrating that apparent motion can be seen from a location outside the visual field to a second location inside the visual field. Recent physiological results suggest that target locations are "remapped" on retinotopic representations to correct for the effects of eye movements. Our results suggest that the representations on which this remapping occurs include locations that fall beyond the limits of the retina.

  17. The relationship between job enrichment and abdominal obesity: a longitudinal field study of apparently healthy individuals.

    Science.gov (United States)

    Fried, Yitzhak; Laurence, Gregory A; Shirom, Arie; Melamed, Samuel; Toker, Sharon; Berliner, Shlomo; Shapira, Itzhak

    2013-10-01

    Obesity has become an epidemic in modern society. However, there is a paucity of research about how job context affects obesity. To enhance our knowledge we used a large, heterogeneous sample of apparently healthy employees (n = 1,949) across two time periods with an average of close to 3.5 years between measures. We tested a hypothesized curvilinear effect of job enrichment on changes in two stress related indicators of abdominal obesity over time: waist circumference (WC) and waist-hip ratio (WHR). Job enrichment consisted of the job dimensions of variety, identity, significance, autonomy, and feedback, and in our analysis we controlled for demographics and health related behaviors, including weekly sports activity, number of cigarettes smoked per day, and weekly alcohol consumption. The results supported the hypothesized U-shaped relationship between job enrichment and changes in both indicators of abdominal obesity over time, such that the level of abdominal obesity was reduced when job enrichment was moderate and was increased when job enrichment was either high or low. As expected, no such association was observed for the general obesity measure of body mass index (BMI). We discuss the theoretical and practical implications of these results. PMID:24001329

  18. Changes in body composition in apparently healthy urban Indian women up to 3 years postpartum

    Directory of Open Access Journals (Sweden)

    Neha A Kajale

    2015-01-01

    Full Text Available Introduction: Dietary and life style practices differ in postpartum (PP and nonpregnant Indian women. Effect of these practices on postpartum weight retention (PPWR and development of cardio-metabolic risk (CMR has been scarcely studied in urban women. Aims of this study were to (i compare anthropometry, biochemical parameters and body composition up to 3 years PP (ii effect of PPWR, dietary fat intake and physical activity on CMR factors. Methods: Design: Cross-sectional, 300-fullterm, apparently healthy primi-parous women (28.6 ± 3.4 years randomly selected. 128 women within 7-day of delivery (Group-A, 88 with 1-2 years (Group-B and 84 with 3-4-year-old-children (Group-C were studied. Anthropometry, sociodemographic status, physical activity, diet, clinical examination, biochemical tests, body composition, at total body (TB, by dual energy X-ray absorptiometry (GE-Lunar DPX were collected. Results: Women at 3-year PP showed higher weight retention (6.5[10] kg than at 1-year (3.0[7] kg (median [IQR]. Android fat % (central obesity increased (P 0.1. Conclusion: Postdelivery, low physical activity and higher PPWR may increase CMR in Indian women.

  19. Reduced apparent photorespiration by the C3-C4 intermediate species, Moricandia arvensis and Panicum milioides

    International Nuclear Information System (INIS)

    The CO2/O2 specificity factor of sucrose gradient purified ribulose 1,5-bisphosphate carboxylase/oxygenase from the C3-C4 intermediate plants Moricandia arvensis and Panicum milioides was similar to the respective values of the enzyme from the closely related C3 species, Moricandia foetida and Panicum laxum. Thus, the kinetic properties of this bifunctional enzyme do not explain the reduced rates of photorespiration exhibited by either of these intermediate species. Dark/light ratios for aminoacetonitrile-sensitive 14CO2 evolution during decarboxylation of exogenous [1-14C] glycine by leaf discs had values of 9.0 with M. arvensis and 11.8 with P. milioides. Similar results were obtained using [1-14C] glycolate as the exogenous photorespiratory substrate, with dark/light 14CO2 evolution ratios for the C3-C4 and C3 leaf discs averaging 6.6 and 2.0, respectively. The data suggest that P. milioides and M. arvensis are capable of a more efficient internal recycling of photorespiratory CO2 via ribulose bisphosphate carboxylase/oxygenase than closely related C3 plants, and that this may partially account for the reduced rates of apparent photorespiration by these intermediate species

  20. On the Apparent Lack of Be X-ray Binaries with Black Holes

    CERN Document Server

    Belczynski, Krzysztof

    2009-01-01

    In the Galaxy there are 64 Be X-ray binaries. Out of those, 42 host a neutron star, and for the reminder the nature of a companion is not known. None, so far, is known to host a black hole. There seems to be no apparent mechanism that would prevent formation or detection of Be stars with black holes. This disparity is referred to as a missing Be -- black hole X-ray binary problem. We point out that current evolutionary scenarios that lead to the formation of Be X-ray binaries predict that the ratio of these binaries with neutron stars to the ones with black holes is rather high F_NStoBH = 10--50, with the more likely formation models providing the values at the high end. The ratio is a natural outcome of (i) the stellar initial mass function that provides more neutron stars than black holes and (ii) common envelope evolution (i.e. a major mechanism involved in the formation of interacting binaries) that naturally selects progenitors of Be X-ray binaries with neutron stars (comparable mass binaries have more l...