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Sample records for stepwise complexometric determination

  1. Selective masking and demasking for the stepwise complexometric determination of aluminium, lead and zinc from the same solution

    Directory of Open Access Journals (Sweden)

    Singh Nahar

    2008-03-01

    Full Text Available Abstract Background A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(IISO4 solution using Erichrome Black-T as the indicator. Subsequently selective de-masking agents – triethanolamine, 2,3-dimercaptopropanol and a formaldehyde/acetone mixture – were used to determine quantities of aluminium, lead and zinc in a stepwise and selective manner. Results The accuracy of the method was established by analysing glass certified reference material NBS 1412. The standard deviation of the measurements, calculated by analysing five replicates of each sample, was found to be less than 1.5% for the method proposed. Conclusion The novelty of the method lies in its simplicity and accuracy afforded by there not being a need for a prior separation or instrumentation. The proposed method was found to be highly selective for the precise determination of aluminum, zinc and lead in the routine analysis of glass batch and allied materials.

  2. Selective masking and demasking for the stepwise complexometric determination of aluminium, lead and zinc from the same solution

    OpenAIRE

    Kayal, Nijhuma; Singh, Nahar

    2008-01-01

    Abstract Background A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(II)SO4 solution using Erichrome Black-T as the indicator. Subsequently selective de-masking agents – t...

  3. Complexometric determination, Part II: Complexometric determination of Cu2+-ions

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2002-01-01

    Full Text Available A copper-selective electrode of the coated wire type based on sulphidized copper wire was applied successfully for determining Cu(II ions by complexometric titration with the disodium salt of EDTA (complexon III. By the formation of internal complex compounds with the Cu(II ion, the copper concentration in the solution decreases, and all this is followed by a change of potential of the indicator system Cu-DWISE (or Cu-EDWISE/SCE. At the terminal point of titration, when all the Cu(II ions are already utilized for the formation of the complex with EDTA, there occurs a steep rise of potential, thus enabling us, through the first or second derivative to note the quantity of copper that is present in the solution. Copper-selective electrode showed a responsivity towards titration with EDTA as a complexing agent, with the absence of "fatigue" due to a great number of repeated measurings. Errors occurring during quantitative measurements were more a characteristic of the overall procedure which involve, because of the impossibility of the complete absence of subjectivity, a constant error, and the reproducibility of the results confirmed this fact. The disodium salt of EDTA appeared as a very efficient titrant in all titrations and with various concentrations ot Cu(II ions in the solution, with somewhat weaker response at lower concentrations in the solution.

  4. Complexometric determination of scandium and aluminium

    International Nuclear Information System (INIS)

    Tikhonov, V.N.

    1980-01-01

    Described is the complexometric determination of scandium and aluminium by the method of reverse titration of EDTA excess by indium salt solution in the presence of the xylenol orange indicator. For the method selectivity increase fluorides are used as a camouflage substance at low pH values (2.5-3.0). The excess fluoride-ions preventing titration are bound by boric acid. Y, Tb, Ti, Zr, Cu, Zn, V, Mo, Co, Cr prevent the determination of Sc and Al

  5. A Simple and Rapid Complexometric Determination of Thallium(III ...

    African Journals Online (AJOL)

    A simple, rapid and selective complexometric method is proposed for the determination of thallium(III), using mercaptoethane(EtSH) as demasking agent. The sample solution containing Tl(III) is first complexed with excess EDTA and the surplus EDTA is removed by titration at pH 5–6 with zinc sulphate solution using ...

  6. Complexometric determination of lanthanum and calcium in lanthanum chromite

    International Nuclear Information System (INIS)

    Novoselova, I.M.

    1989-01-01

    Methods of complexometric determination of lanthanum and calcium in lanthanum chromite, based on sequential titration of La and Ca by EDTA solution, where as an indicator eriochrome brack T with NaCl mixture in the ratio of 1:100 is used, are determined. Cr (3) effect was removed by its oxidation up to Cr (6) with perchloric acid; at first La was determined in presence of urotropine buffer, then Ca at pH 9.5-10 in presence of ammonia buffer. For reaction acceleration method of back titration of EDTA excess by zinc salt solution was used. Standard deviation in La and Ca determination is not over 0.2 and 0.1 % respectively

  7. Complexometric determination of rare earth elements in quartz glasses with indicator xylenol orange-cetylpyridinium chloride

    International Nuclear Information System (INIS)

    Svistunova, G.P.; Amelin, V.G.

    1988-01-01

    A study was made on possibility of using the system xylenol orange (XO)-cetypyridinium determination of REE. XO forms with REE in the presence of CP intensively coloured complexes with absorbtion maximums at 610-615 nm. Colour transformation from blue to yellow is observed during complexometric titration in CP presence in the final point of titration by EDTA solution. The method was applied for Eu and Ce determination in alloyed quartz glasses. Titanium doesn't prevent REE determination at its content in titrated solution up to 1 mg. Other elements affect slightly the results. The method is recommended to use for 0.1-0.7% REE determination in quartz glasses of 0.5-1.5 g samples

  8. Complexometric determination of rare earth elements in quartz glasses with indicator xylenol orange-cetylpyridinium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Svistunova, G P; Amelin, V G

    1988-11-01

    A study was made on possibility of using the system xylenol orange (XO)-cetypyridinium determination of REE. XO forms with REE in the presence of CP intensively coloured complexes with absorbtion maximums at 610-615 nm. Colour transformation from blue to yellow is observed during complexometric titration in CP presence in the final point of titration by EDTA solution. The method was applied for Eu and Ce determination in alloyed quartz glasses. Titanium doesn't prevent REE determination at its content in titrated solution up to 1 mg. Other elements affect slightly the results. The method is recommended to use for 0.1-0.7% REE determination in quartz glasses of 0.5-1.5 g samples.

  9. A novel biamperometric methodology for thorium determination by EDTA complexometric titration

    International Nuclear Information System (INIS)

    Jayachandran, K.; Gamare, J.S.; Nair, P.R.; Xavier, M.; Aggarwal, S.K.

    2012-01-01

    A biamperometric methodology is described for the determination of thorium by EDTA complexometric titration, based on the observed electrochemical behaviour of EDTA when the applied potential was ≥ 200 mV between the twin Pt electrodes. Studies carried out showed that a pH range of 2.4-2.7 was optimum for the determination. Accuracy and precision of the method were evaluated using different amounts of thorium ranging from 50 μg to 5 mg. Studies on the interference of uranium were carried out with different amounts of uranium ranging from 20 to 80% using the presently developed approach of biamperometry as well as the conventional indicator method. The method was employed for the determination of Th in (Th,U)O 2 samples containing different amounts of Th and U. (orig.)

  10. Sodium dithionite as a selective demasking agent for the complexometric determination of thallium

    Directory of Open Access Journals (Sweden)

    PRAKASH SHETTY

    2005-11-01

    Full Text Available Sodium dithionite is proposed as a new demasking agent for the rapid and selective complexometric determination of thallium(III. In the presence of diverse metal ions, thallium (III was first complexed with excess EDTA and the surplus EDTAwas then titrated with a standard zinc sulphate solution at pH 5–6 (hexamine buffer using Xylenol Orange as the indicator. The EDTAequivalent to thallium was then released selectively with sodium dithionite and back titrated with a standard zinc sulphate solution as before. Reproducible and accurate results were obtained in the range 4–100 mg of thallium with a relative error of ±27 % and a coefficient of variation (n = 6 of not more than 0.30 %. The effects of various diverse ions were studied. The method was applied to the determination of thallium in its complexes and in alloys.

  11. Indirect complexometric determination of mercury(II) using potassium bromide as selective masking agent

    International Nuclear Information System (INIS)

    Sreekumar, N.V.; Nazareth, R.A.; Narayana, B.; Hegde, P.; Manjunatha, B.R.

    2002-01-01

    A complexometric method for the determination of mercury in presence of other metal ions based on the selective masking ability of potassium bromide towards mercury is described. Mercury(II) present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated against zinc sulfate solution at pH 5-6 using xylenol orange as the indicator. A known excess of 10 % solution of potassium bromide is then added and the EDTA released from Hg-EDTA complex is titrated against standard zinc sulfate solution. Reproducible and accurate results are obtained for 8 mg to 250 mg of mercury(II) with a relative error ±0.28 % and standard deviations /leg 0.5 mg. The interference of various ions is studied. This method was applied to the determination of mercury(II) in its alloys. (author)

  12. Indirect complexometric determination of thorium(IV) using sodium fluoride as masking agent

    International Nuclear Information System (INIS)

    Sreekumar, N.V.; Nazareth, R.A.; Narayana, B.; Hegde, P.; Manjunatha, B.R.

    2002-01-01

    A complexometric method for the determination of thorium(IV) in presence of other metal ions based on the selective masking ability of sodium fluoride towards thorium is described. Thorium(IV) present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated against bismuth nitrate solution at pH 2-3 using xylenol orange as indicator. A known excess of sodium fluoride (5 %) is then added and the EDTA released from the Th-EDTA complex is titrated against standard bismuth nitrate solution. Reproducible and accurate results are obtained for 5 mg to 280 mg of thorium with relative errors ±0.65 % and standard deviations /leq 0.75 mg. The interference of various ions was studied. (author)

  13. Complexometric determination of trivalent rare earths and actinides with diethylene-triaminepentaacetic acid

    International Nuclear Information System (INIS)

    Timofeev, G.A.; Simakin, G.A.; Baklanova, P.F.; Kuznetsov, G.F.; Ivanov, V.I.

    1976-01-01

    Optimal conditions have been found for the separate quantitative determination of 200 to 500 mcg of trivalent Eu, La, Nd, Pr, Am and Cm by complexometric titration with diethylenetriaminepentaacetic acid. The final titration point (FTP) has been determined by using one of the following three methods, namely by visual inspection with the aid of xylene orange as an indicator, spectrophotometrically at pH 4.5-4.7 with xylene orange and potentiometrically at pH 4.0-5.5 through the backward titration of the excess complexone with the solution of Fe(3) in HNO 3 . The relative standard errors Ssub(r)=0.004 (Eu), 0.011 Cm with the visual indication of FTP; Ssub(r)=0.005 (Am) with the spectrophotometric indication of FTP; Ssub(r)=0.0O9 (Eu), 0.011 (Pr) and 0.02 (Am) with the potentiometric indication of FTP. Determination of trivalent lanthanides and actinoids is adversely affected by tetravalent actinoids, Zr, U(6), Hg(2) and Fe(3). Titration conditions chosen have been checked in the analysis of the mixture containing the sum of trivalent rare earths, Am and Cm [ru

  14. Complexometric determination of thallium(III using ethanethiol as a selective masking agent

    Directory of Open Access Journals (Sweden)

    Karthikeyan J.

    2006-01-01

    Full Text Available A simple and selective complexometric method for the determination of thallium in presence of other metal ions is proposed based on the selective masking ability of ethanethiol towards thallium(III. Thallium present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated with standard zinc sulphate solution at pH 5-6(hexamine using xylenol orange as the indicator. A 0.3% aqueous solution of ethanethiol is then added to displace EDTA from the Tl(III-EDTA complex. The released EDTA is titrated with standard zinc sulphate solution as before. Reproducible and accurate results are obtained for 3.70 mg to 74.07 mg of Tl (III with relative error less than ? 0.44% and coefficient of variation not more than 0.27%. The interference of various ions was studied and the method was used for the analysis of thallium in its synthetic alloy mixtures and also in complexes.

  15. Complexometric determination of aluminium and scandium using fluorides as masking agent at low pH value

    International Nuclear Information System (INIS)

    Tikhonov, V.N.

    1978-01-01

    A complexometric method is suggested to determine Al and Sc by back titration of Bi(NO 3 ) 3 solution with xylenol orange indicator at low pH values. To increase selectivity fluoride additions were used which were masked by boron acid at the end titration point. EDTA was used as a complexing agent. Metals which create at low pH values stable complexes with EDTA undestroyed by fluoride, do not interfere with Al and Sc determination. Scandium is shown to be determined more selectively than aluminium

  16. Selective complexometric determination of titanium(IV) using sodium potassium tartrate or ascorbic acid as masking agent

    International Nuclear Information System (INIS)

    Sreekumar, N.V.; Bhat, N.G.; Narayana, B.; Nazareth, R.A.; Hegde, P.; Manjunatha, B.R.

    2003-01-01

    A simple, rapid and accurate complexometric method is proposed for the determination of titanium(IV) where sodium potassium tartrate or ascorbic acid were used as masking agents. In the presence of diverse metal ions, titanium is first complexed with excess of EDTA and surplus EDTA is then titrated at pH 5-6 with zinc sulfate, xylenol orange being used as indicator. An excess of 5 % aqueous sodium potassium tartrate is then added to displace the complexed EDTA from the Ti-EDTA complex quantitatively, which is titrated with zinc sulfate. Also, ascorbic acid may be used as the releasing agent. The methods work well in the range 1-53 mg of Ti(IV) for sodium potassium tartrate with relative errors ± 0.28 % and standard deviations 0.16 mg. For ascorbic acid the range is 1.00-30.00 mg of Ti(IV) with relative errors of ± 0.40 % and standard deviations of 0.05 mg. (author)

  17. Evaluation and comparison of two complexometric titration methods for determining of lanthanum in cloridric solutions

    International Nuclear Information System (INIS)

    Menezes, M.F.; Santos, R.L.C. dos; Goes, M.A.C. de

    1994-01-01

    The fast determination of total rare earth concentration in aqueous solutions is based on titrimetric methods using EDTA as complexing agent. This paper evaluates two among several others titrimetric methods used in the determination of lanthanum in hydrochloric acid solutions, using xylenol orange and a mixture of methyl orange and xylenol orange as indicators. The applied statistical evaluation allowed the determination of the stability, accuracy and adequacy of these methods on a given technical specification. (author). 12 refs., 03 tabs., 01 fig

  18. Complexometric determination: Part I - EDTA and complex formation with the Cu2+ ion

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    Rajković Miloš B.

    2002-01-01

    Full Text Available Compounds forming very stable complexes - chelates, have a wide field of application in analytical chemistry. The most famous group of these compounds are complexons. Complexons represent organic polyaminocarbonic acids as for example ethylenediaminetetraacetic acid (EDTA and its salts. The EDTA molecule has six coordinative sites. It is a hexadentate ligands i.e. it has two binding nitrogen atoms and four oxygen atoms from carboxyl groups and it forms complexes with almost all metal ions. EDTA as a tetraprotonic acid, H4Y disociates through four steps, yielding the ions HsY-, H2Y2-, HY3- and Y4-. Which of the EDTA forms will be encountered in a solution, depends on the pH. Due to the poor solubility of EDTA in pure water, as well as in most organic solvents, the disodium salt of EDTA Na2H2Y-2H2O, under the commercial name complexon III, is utilized for analytical determinations. In water, EDTA forms soluble, stabile chelate complexes with all cations, at the molar ratio 1:1, regardless of the charge of the metal ion. In contrast to other equilibria, which are mainly defined by Le Chatellier's principle, equilibria related to metal-EDTA complex formation are also dependent on the influence of the secondary equilibria of EDTA complex formation. Complexing reactions, which are equilibrium reactions, are simultaneously influenced by the following factors: solution pH and the presence of complexing agents which may also form a stabile complex with metal ions. The secondary reaction influence may be viewed and monitored through conditional stability constants. In the first part of the paper, the reaction of the formation of the Cu2+-ion complex with EDTA is analyzed beginning from the main reaction through various influences of secondary reactions on the complex Cu2+-EDTA: pH effect, complexation effect and hydrolysis effect. The equations are given for conditional stability constants, which include equilibrium reactions under actual conditions.

  19. Stepwise Inquiry into Hard Water in a High School Chemistry Laboratory

    Science.gov (United States)

    Kakisako, Mami; Nishikawa, Kazuyuki; Nakano, Masayoshi; Harada, Kana S.; Tatsuoka, Tomoyuki; Koga, Nobuyoshi

    2016-01-01

    This study focuses on the design of a learning program to introduce complexometric titration as a method for determining water hardness in a high school chemistry laboratory. Students are introduced to the different properties and reactions of hard water in a stepwise manner so that they gain the necessary chemical knowledge and conceptual…

  20. Graphical evaluation of complexometric titration curves.

    Science.gov (United States)

    Guinon, J L

    1985-04-01

    A graphical method, based on logarithmic concentration diagrams, for construction, without any calculations, of complexometric titration curves is examined. The titration curves obtained for different kinds of unidentate, bidentate and quadridentate ligands clearly show why only chelating ligands are usually used in titrimetric analysis. The method has also been applied to two practical cases where unidentate ligands are used: (a) the complexometric determination of mercury(II) with halides and (b) the determination of cyanide with silver, which involves both a complexation and a precipitation system; for this purpose construction of the diagrams for the HgCl(2)/HgCl(+)/Hg(2+) and Ag(CN)(2)(-)/AgCN/CN(-) systems is considered in detail.

  1. Simultaneous complexometric determination of bismuth and indium in thermoelectronic material (Bisub(1-x)Insub(x))2Te3

    International Nuclear Information System (INIS)

    Danzaki, Yuetsu; Shoji, Tsutomu; Sase, Masahiko; Takeyama, Shuro

    1983-01-01

    A sample of 0.1 g was dissolved in 5 ml of conc. HNO 3 and diluted to about 100 ml with water. To the sample solution 20 % KOH solution was added so as to make 2 % KOH alkaline solution. The solution was boiled for about 5 min and cooled in running water. The coagulated precipitate was filtered and washed with 1 % KOH solution. The precipitate on the filter paper was dissolved in 15 ml of hot HNO 3 (1 + 1), and washed with warm HNO 3 (2 + 100). After the filtrate was evaporated to about 2 ml and diluted to about 10 ml with water, 20 ml of 0.02 M EDTA was added and diluted to about 100 ml. The pH of the solution was adjusted to 5--5.5 with hexamethylenetetramine. The ex cess of EDTA was back-titrated with 0.01 M Pb(NO 3 ) 2 in the presence of MTBas an indicater, and total amounts of Bi and In were determined. To the same solution, 1 g of ascorbic acid was added, and pH was adjusted to 10 with ammoniacal water. After (1--2) min, the liberated EDTA was titrated with 0.01 M MnCl 2 , and the amount of Bi was determined. The results obtained with complexometry were compared with those of BiOCl gravimetry for Bi and atomic absorption for In. (author)

  2. Indirect complexometric determination of mercury(II in synthetic alloys and complexes using ethanethiol as a selective masking agent

    Directory of Open Access Journals (Sweden)

    J. KARTHIKEYAN

    2006-03-01

    Full Text Available Acomplexometric method for the determination of mercury(II in presence of other metal ions, based on the selective masking action of ethanethiol towards mercury(II is described. Mercury(II present in a given sample solution is first complexed with an excess of EDTAand the unreacted EDTAis titrated against zinc sulphate solution at pH 5–6 (hexamine buffer using xylenol orange as the indicator. An excess of a 0.3 % solution of ethanethiol is then added to displace EDTA from the Hg(II–EDTA complex. The released EDTAis titrated with a standard zinc sulphate solution. Reproducible and accurate results are obtained for 4–85 mg of mercury(II with a relative error of less than ± 0.46 % and coefficient of variation of not more than 0.47 %. The effects of the presence of various ions were studied. The method can be used for the analysis of mercury in its synthetic alloy mixtures and also in complexes.

  3. Simultaneous complexometric determination of bismuth and indium in thermoelectronic material (Bisub(1-x)Insub(x))/sub 2/Te/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Danzaki, Yuetsu; Shoji, Tsutomu; Sase, Masahiko; Takeyama, Shuro [Tohoku Univ., Sendai (Japan). Research Inst. for Iron, Steel and Other Metals

    1983-08-01

    A sample of 0.1 g was dissolved in 5 ml of conc. HNO/sub 3/ and diluted to about 100 ml with water. To the sample solution 20 % KOH solution was added so as to make 2 % KOH alkaline solution. The solution was boiled for about 5 min and cooled in running water. The coagulated precipitate was filtered and washed with 1 % KOH solution. The precipitate on the filter paper was dissolved in 15 ml of hot HNO/sub 3/ (1 + 1), and washed with warm HNO/sub 3/ (2 + 100). After the filtrate was evaporated to about 2 ml and diluted to about 10 ml with water, 20 ml of 0.02 M EDTA was added and diluted to about 100 ml. The pH of the solution was adjusted to 5--5.5 with hexamethylenetetramine. The excess of EDTA was back-titrated with 0.01 M Pb(NO/sub 3/)/sub 2/ in the presence of MTBas an indicater, and total amounts of Bi and In were determined. To the same solution, 1 g of ascorbic acid was added, and pH was adjusted to 10 with ammoniacal water. After (1--2) min, the liberated EDTA was titrated with 0.01 M MnCl/sub 2/, and the amount of Bi was determined. The results obtained with complexometry were compared with those of BiOCl gravimetry for Bi and atomic absorption for In.

  4. Vapor permeation-stepwise injection simultaneous determination of methanol and ethanol in biodiesel with voltammetric detection.

    Science.gov (United States)

    Shishov, Andrey; Penkova, Anastasia; Zabrodin, Andrey; Nikolaev, Konstantin; Dmitrenko, Maria; Ermakov, Sergey; Bulatov, Andrey

    2016-02-01

    A novel vapor permeation-stepwise injection (VP-SWI) method for the determination of methanol and ethanol in biodiesel samples is discussed. In the current study, stepwise injection analysis was successfully combined with voltammetric detection and vapor permeation. This method is based on the separation of methanol and ethanol from a sample using a vapor permeation module (VPM) with a selective polymer membrane based on poly(phenylene isophtalamide) (PA) containing high amounts of a residual solvent. After the evaporation into the headspace of the VPM, methanol and ethanol were transported, by gas bubbling, through a PA membrane to a mixing chamber equipped with a voltammetric detector. Ethanol was selectively detected at +0.19 V, and both compounds were detected at +1.20 V. Current subtractions (using a correction factor) were used for the selective determination of methanol. A linear range between 0.05 and 0.5% (m/m) was established for each analyte. The limits of detection were estimated at 0.02% (m/m) for ethanol and methanol. The sample throughput was 5 samples h(-1). The method was successfully applied to the analysis of biodiesel samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Complexometric consequent titration of bismuth-titanium mixtures in the μg-region

    International Nuclear Information System (INIS)

    Schaefer, H.

    1975-01-01

    A quantitative method is described for the determination of microquantities of bismuth and titanium. Both metals are determined complexometrically with EDTA and potentiometric equivalence point indication using a Cu-ion sensitive electrode in a consequent titration. The analysis is conducted as back-titration with standard Cu-solution. The relative error of the determination is 0.8% for bismuth (50-100 μg) and for titanium (10-30 μg) at 1.0%. Under the chosen conditions, it is possible to determine as little as 15 μg bismuth and 5 μg titanium by means of this procedure. (author)

  6. The Effect of Metal Concentration on the Parameters Derived from Complexometric Titrations of Trace Elements in Seawater—A Model Study

    NARCIS (Netherlands)

    Gledhill, M.; Gerringa, L.J.A.

    2017-01-01

    In this study we examine the impact of dissolved metal concentrations on the parametersthat are commonly determined from complexometric titrations in seawater. We use thenon-ideal competitive adsorption (NICA) model within the framework of the chemicalspeciation program visual MINTEQ with iron as a

  7. Complexometric Determination of Mercury Based on a Selective Masking Reaction

    Science.gov (United States)

    Romero, Mercedes; Guidi, Veronica; Ibarrolaza, Agustin; Castells, Cecilia

    2009-01-01

    In the first analytical chemistry course, students are introduced to the concepts of equilibrium in water solutions and classical (non-instrumental) analytical methods. Our teaching experience shows that "real samples" stimulate students' enthusiasm for the laboratory work. From this diagnostic, we implemented an optional activity at the end of…

  8. A fully automated effervescence assisted dispersive liquid–liquid microextraction based on a stepwise injection system. Determination of antipyrine in saliva samples

    International Nuclear Information System (INIS)

    Medinskaia, Kseniia; Vakh, Christina; Aseeva, Darina; Andruch, Vasil; Moskvin, Leonid; Bulatov, Andrey

    2016-01-01

    A first attempt to automate the effervescence assisted dispersive liquid–liquid microextraction (EA-DLLME) has been reported. The method is based on the aspiration of a sample and all required aqueous reagents into the stepwise injection analysis (SWIA) manifold, followed by simultaneous counterflow injection of the extraction solvent (dichloromethane), the mixture of the effervescence agent (0.5 mol L"−"1 Na_2CO_3) and the proton donor solution (1 mol L"−"1 CH_3COOH). Formation of carbon dioxide microbubbles generated in situ leads to the dispersion of the extraction solvent in the whole aqueous sample and extraction of the analyte into organic phase. Unlike the conventional DLLME, in the case of EA-DLLME, the addition of dispersive solvent, as well as, time consuming centrifugation step for disruption of the cloudy state is avoided. The phase separation was achieved by gentle bubbling of nitrogen stream (2 mL min"−"1 during 2 min). The performance of the suggested approach is demonstrated by determination of antipyrine in saliva samples. The procedure is based on the derivatization of antipyrine by nitrite-ion followed by EA-DLLME of 4-nitrosoantipyrine and subsequent UV–Vis detection using SWIA manifold. The absorbance of the yellow-colored extract at the wavelength of 345 nm obeys Beer's law in the range of 1.5–100 µmol L"−"1 of antipyrine in saliva. The LOD, calculated from a blank test based on 3σ, was 0.5 µmol L"−"1. - Highlights: • First attempt to automate the effervescence assisted dispersive liquid–liquid microextraction. • Automation based on Stepwise injection analysis manifold in flow batch system. • Counterflow injection of extraction solvent and the effervescence agent. • Phase separation performed by gentle bubbling of nitrogen. • Application for the determination of antipyrine in saliva samples.

  9. A fully automated effervescence assisted dispersive liquid–liquid microextraction based on a stepwise injection system. Determination of antipyrine in saliva samples

    Energy Technology Data Exchange (ETDEWEB)

    Medinskaia, Kseniia; Vakh, Christina; Aseeva, Darina [Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, RU-198504 Saint Petersburg (Russian Federation); Andruch, Vasil, E-mail: vasil.andruch@upjs.sk [Department of Analytical Chemistry, University of P.J. Šafárik, SK-04154 Košice (Slovakia); Moskvin, Leonid [Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, RU-198504 Saint Petersburg (Russian Federation); Bulatov, Andrey, E-mail: bulatov_andrey@mail.ru [Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, RU-198504 Saint Petersburg (Russian Federation)

    2016-01-01

    A first attempt to automate the effervescence assisted dispersive liquid–liquid microextraction (EA-DLLME) has been reported. The method is based on the aspiration of a sample and all required aqueous reagents into the stepwise injection analysis (SWIA) manifold, followed by simultaneous counterflow injection of the extraction solvent (dichloromethane), the mixture of the effervescence agent (0.5 mol L{sup −1} Na{sub 2}CO{sub 3}) and the proton donor solution (1 mol L{sup −1} CH{sub 3}COOH). Formation of carbon dioxide microbubbles generated in situ leads to the dispersion of the extraction solvent in the whole aqueous sample and extraction of the analyte into organic phase. Unlike the conventional DLLME, in the case of EA-DLLME, the addition of dispersive solvent, as well as, time consuming centrifugation step for disruption of the cloudy state is avoided. The phase separation was achieved by gentle bubbling of nitrogen stream (2 mL min{sup −1} during 2 min). The performance of the suggested approach is demonstrated by determination of antipyrine in saliva samples. The procedure is based on the derivatization of antipyrine by nitrite-ion followed by EA-DLLME of 4-nitrosoantipyrine and subsequent UV–Vis detection using SWIA manifold. The absorbance of the yellow-colored extract at the wavelength of 345 nm obeys Beer's law in the range of 1.5–100 µmol L{sup −1} of antipyrine in saliva. The LOD, calculated from a blank test based on 3σ, was 0.5 µmol L{sup −1}. - Highlights: • First attempt to automate the effervescence assisted dispersive liquid–liquid microextraction. • Automation based on Stepwise injection analysis manifold in flow batch system. • Counterflow injection of extraction solvent and the effervescence agent. • Phase separation performed by gentle bubbling of nitrogen. • Application for the determination of antipyrine in saliva samples.

  10. Stepwise management of asthma.

    Science.gov (United States)

    Khalid, Ayesha N

    2015-09-01

    Stepwise management of asthma remains an area of evolving research. Asthma is one of the most expensive chronic diseases in the United States; stepwise management is an important area of focus, with several recent guidelines recommending management. This is a review of published English language literature, focusing on management guidelines for asthma in adult and pediatric patients. Asthma is a chronic disease whose assessment of severity allows for therapeutic goals to match the impairment noted. Good evidence exists to aid risk reduction, leading to decreased emergency room visits, preventing loss of lung function in adults and lung growth in children, and optimizing pharmacotherapy with reduced side effects profile. Recent asthma management guidelines incorporate 4 components of asthma care including: monitoring of severity, patient education, controlling external triggers, and medications, including recent attention to medication adherence. Asthma is an expensive chronic disease with preventive measures leading to reduced healthcare costs. Future targeted cytokine therapy to decrease serum and blood eosinophils may become an integral part of asthma management. © 2015 ARS-AAOA, LLC.

  11. Modified approaches to the complexometric extraction of metal ions into supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Ager, P.; Lopez, C.D.; Marshall, W.D.

    2000-01-01

    A modified nebulizing assembly from a commercial atomic absorption spectrometry (AAS) unit served to interface the eluate from a supercritical carbon, dioxide (Sc-CO 2 ) extractor with a flame atomic absorption spectrometer and provided low to sub-ng limits of detection for several elements that were detected only inefficiently with an all-silica T-tube interface. The unit was used to monitor the progress of complexometric extractions of cobalt and nickel (2.5 or 25 μg/ml) from aqueous medium. Modifications to the general process for metal mobilisation included (i) a back-filling procedure during the initial pressurisation of the extractor and (ii) the separation of the derivatization reaction from the subsequent extraction. When coupled with (iii) the addition of ethyl acetate or methylisobutyl Ketone to the mobile phase, residual levels of analyte Co and Ni were reduced to the limit of detection with a single extraction. A heated column of iron granules Fe o efficiently removed metal 2,4-pentanedionate and diethyldithiocarbamate complexes from the SCF extractor eluate but did not liberate any complexing reagent. A sea sand column, heated to the same temperature, was less efficient at removing metals but did liberate modest amounts of 2,4-pentanedione back into the mobile phase. (author)

  12. Direct 40Ar/39Ar age determination of fluid inclusions using in-vacuo¬ stepwise crushing - Example of garnet from the Cycladic Blueschist Unit on Syros

    Science.gov (United States)

    Uunk, Bertram; Postma, Onno; Wijbrans, Jan; Brouwer, Fraukje

    2017-04-01

    Metamorphic minerals and veins commonly trap attending hydrous fluids in fluid inclusions, which yield a wealth of information on the history of the hosting metamorphic system. When these fluids are sufficiently saline, the KCl in the inclusions can be used as a K/Ar geochronologic system, potentially dating inclusion incorporation. Whilst primary fluid inclusions (PFIs) can date fluid incorporation during mineral or vein growth, secondary fluid inclusion trails (SFIs) can provide age constraints on later fluid flow events. At VU Amsterdam, a new in-vacuo crushing apparatus has been designed to extract fluid inclusions from minerals for 40Ar/39Ar analysis. Separates are crushed inside a crusher tube connected to a purification line and a quadrupole mass spectrometer. In-vacuo crushing is achieved by lifting and dropping a steel pestle using an externally controlled magnetic field. As the gas can be analyzed between different crushing steps, the setup permits stepwise crushing experiments. Additionally, crushed powder can be heated by inserting the crusher tube in an externally controlled furnace. Dating by 40Ar/39Ar stepwise crushing has the added advantage that, during neutron irradiation to produce 39Ar from 39K, 38Ar and 37Ar are also produced from 38Cl and 40Ca, respectively. Simultaneous analysis of these argon isotopes permits constraining the chemistry of the argon source sampled during the experiment. This allows a distinction between different fluid or crystal lattice sources. Garnet from three samples of the HP metamorphic Cycladic Blueschist Unit on Syros, Greece was stepwise crushed to obtain fluid inclusion ages. Initial steps for all three experiments yield significant components of excess argon, which are interpreted to originate from grain boundary fluids and secondary fluid inclusions trails. During subsequent steps, age results stabilize to a plateau age. One garnet from North Syros yields an unusually old 80 Ma plateau age. However, isochrons

  13. A stepwise model to predict monthly streamflow

    Science.gov (United States)

    Mahmood Al-Juboori, Anas; Guven, Aytac

    2016-12-01

    In this study, a stepwise model empowered with genetic programming is developed to predict the monthly flows of Hurman River in Turkey and Diyalah and Lesser Zab Rivers in Iraq. The model divides the monthly flow data to twelve intervals representing the number of months in a year. The flow of a month, t is considered as a function of the antecedent month's flow (t - 1) and it is predicted by multiplying the antecedent monthly flow by a constant value called K. The optimum value of K is obtained by a stepwise procedure which employs Gene Expression Programming (GEP) and Nonlinear Generalized Reduced Gradient Optimization (NGRGO) as alternative to traditional nonlinear regression technique. The degree of determination and root mean squared error are used to evaluate the performance of the proposed models. The results of the proposed model are compared with the conventional Markovian and Auto Regressive Integrated Moving Average (ARIMA) models based on observed monthly flow data. The comparison results based on five different statistic measures show that the proposed stepwise model performed better than Markovian model and ARIMA model. The R2 values of the proposed model range between 0.81 and 0.92 for the three rivers in this study.

  14. An Extended Step-Wise Weight Assessment Ratio Analysis with Symmetric Interval Type-2 Fuzzy Sets for Determining the Subjective Weights of Criteria in Multi-Criteria Decision-Making Problems

    Directory of Open Access Journals (Sweden)

    Mehdi Keshavarz-Ghorabaee

    2018-03-01

    Full Text Available Determination of subjective weights, which are based on the opinions and preferences of decision-makers, is one of the most important matters in the process of multi-criteria decision-making (MCDM. Step-wise Weight Assessment Ratio Analysis (SWARA is an efficient method for obtaining the subjective weights of criteria in the MCDM problems. On the other hand, decision-makers may express their opinions with a degree of uncertainty. Using the symmetric interval type-2 fuzzy sets enables us to not only capture the uncertainty of information flexibly but also to perform computations simply. In this paper, we propose an extended SWARA method with symmetric interval type-2 fuzzy sets to determine the weights of criteria based on the opinions of a group of decision-makers. The weights determined by the proposed approach involve the uncertainty of decision-makers’ preferences and the symmetric form of the weights makes them more interpretable. To show the procedure of the proposed approach, it is used to determine the importance of intellectual capital dimensions and components in a company. The results show that the proposed approach is efficient in determining the subjective weights of criteria and capturing the uncertainty of information.

  15. A Matlab program for stepwise regression

    Directory of Open Access Journals (Sweden)

    Yanhong Qi

    2016-03-01

    Full Text Available The stepwise linear regression is a multi-variable regression for identifying statistically significant variables in the linear regression equation. In present study, we presented the Matlab program of stepwise regression.

  16. The Effect of Metal Concentration on the Parameters Derived from Complexometric Titrations of Trace Elements in Seawater—A Model Study

    Directory of Open Access Journals (Sweden)

    Martha Gledhill

    2017-08-01

    Full Text Available In this study we examine the impact of dissolved metal concentrations on the parameters that are commonly determined from complexometric titrations in seawater. We use the non-ideal competitive adsorption (NICA model within the framework of the chemical speciation program visual MINTEQ with iron as a model metal. We demonstrate that dissolved iron concentrations effect the determined parameters for a heterogeneous binding site distribution with a fixed concentration of dissolved organic carbon. The commonly used terms “ligand concentration” and “binding constant” are therefore dependent on metal concentration, so we adopt the terminology suggested by Town and Filella (2000 and use the terms ligand quotient and stability quotient here. The systematic increase in the ligand quotient with dissolved iron concentration likely contributes toward the trend of increasing ligand quotient with dissolved iron concentration observed in field studies, and makes it hard to assign an objective meaning to the parameter. We suggest that calculation of the side reaction coefficient, a parameter that describes the probability that any added metal will be complexed, could be less prone to bias and misinterpretation than calculation of conditional stability and ligand quotients. We explore the impact of experimental design on side reaction coefficients by applying different detection windows, and multiwindow and reverse titration approaches. We identify the method that results in the best estimates of side reaction coefficients over a range of iron concentrations between 0.1 and 1.5 nmol L−1. We find that single window titrations can only reliably estimate side reaction coefficients over a limited range of iron concentrations. Multiwindow titrations provided estimates of side reaction coefficients within the 99% confidence interval of the values calculated directly from the NICA model at all iron concentrations examined here. We recommend that future

  17. Step-wise stimulated martensitic transformations

    International Nuclear Information System (INIS)

    Airoldi, G.; Riva, G.

    1991-01-01

    NiTi alloys, widely known both for their shape memory properties and for unusual pseudoelastic behaviour, are now on the forefront attention for step-wise induced memory processes, thermal or stress stimulated. Literature results related to step-wise stimulated martensite (direct transformation) are examined and contrasted with step-wise thermal stimulated parent phase (reverse transformation). Hypothesis are given to explain the key characters of both transformations, a thermodynamic model from first principles being till now lacking

  18. Step-wise refolding of recombinant proteins.

    Science.gov (United States)

    Tsumoto, Kouhei; Arakawa, Tsutomu; Chen, Linda

    2010-04-01

    Protein refolding is still on trial-and-error basis. Here we describe step-wise dialysis refolding, in which denaturant concentration is altered in step-wise fashion. This technology controls the folding pathway by adjusting the concentrations of the denaturant and other solvent additives to induce sequential folding or disulfide formation.

  19. Determination of Calcium in Dietary Supplements: Statistical Comparison of Methods in the Analytical Laboratory

    Science.gov (United States)

    Garvey, Sarah L.; Shahmohammadi, Golbon; McLain, Derek R.; Dietz, Mark L.

    2015-01-01

    A laboratory experiment is described in which students compare two methods for the determination of the calcium content of commercial dietary supplement tablets. In a two-week sequence, the sample tablets are first analyzed via complexometric titration with ethylenediaminetetraacetic acid and then, following ion exchange of the calcium ion present…

  20. ANYOLS, Least Square Fit by Stepwise Regression

    International Nuclear Information System (INIS)

    Atwoods, C.L.; Mathews, S.

    1986-01-01

    Description of program or function: ANYOLS is a stepwise program which fits data using ordinary or weighted least squares. Variables are selected for the model in a stepwise way based on a user- specified input criterion or a user-written subroutine. The order in which variables are entered can be influenced by user-defined forcing priorities. Instead of stepwise selection, ANYOLS can try all possible combinations of any desired subset of the variables. Automatic output for the final model in a stepwise search includes plots of the residuals, 'studentized' residuals, and leverages; if the model is not too large, the output also includes partial regression and partial leverage plots. A data set may be re-used so that several selection criteria can be tried. Flexibility is increased by allowing the substitution of user-written subroutines for several default subroutines

  1. COPD: A stepwise or a hit hard approach?

    Directory of Open Access Journals (Sweden)

    A.J. Ferreira

    2016-07-01

    Full Text Available Current guidelines differ slightly on the recommendations for treatment of Chronic Obstructive Pulmonary Disease (COPD patients, and although there are some undisputed recommendations, there is still debate regarding the management of COPD. One of the hindrances to deciding which therapeutic approach to choose is late diagnosis or misdiagnosis of COPD. After a proper diagnosis is achieved and severity assessed, the choice between a stepwise or “hit hard” approach has to be made. For GOLD A patients the stepwise approach is recommended, whilst for B, C and D patients this remains debatable. Moreover, in patients for whom inhaled corticosteroids (ICS are recommended, a step-up or “hit hard” approach with triple therapy will depend on the patient's characteristics and, for patients who are being over-treated with ICS, ICS withdrawal should be performed, in order to optimize therapy and reduce excessive medications.This paper discusses and proposes stepwise, “hit hard”, step-up and ICS withdrawal therapeutic approaches for COPD patients based on their GOLD group. We conclude that all approaches have benefits, and only a careful patient selection will determine which approach is better, and which patients will benefit the most from each approach. Keywords: COPD, Stepwise, Hit hard, Step-up, ICS withdrawal, Bronchodilators, ICS

  2. Use of the stepwise progression return-to-play protocol following concussion among practicing athletic trainers

    Directory of Open Access Journals (Sweden)

    Jessica Wallace

    2018-04-01

    Full Text Available Purpose: The purpose of this study was to determine whether practicing athletic trainers (ATs were using the stepwise progression to make return-to-play (RTP decisions after concussion and to determine what factors influenced their decision to use the stepwise progression. Methods: A total of 166 ATs (response rate = 16.6% completed a 21-item questionnaire that evaluated participant demographics, methods of concussion management, and RTP decision-making using the stepwise progression. Descriptive statistics and a logistic regression were completed to analyze data. Results: Factors such as education level (p = 0.05 and number of concussions treated (p = 0.05 predicted use of the stepwise progression, whereas sex (p = 0.17, employment setting (p = 0.17, state law (p = 0.86, and years practicing (p = 0.17 did not predict whether ATs were following the stepwise progression. Conclusion: The majority of the ATs from this study are employing the stepwise progression to safely return athletes to play after sustaining a concussion. This demonstrates that ATs are providing a standard of care for concussed athletes across various athletic training settings; however, having a graduate degree and treating more concussions per year are predictors of whether an AT follows all steps of the stepwise progression. Keywords: Athletic trainers, Concussion, Concussion management, Graduate degree, Return to play, Sports medicine, Stepwise progression

  3. Significance of stepwise excretion pattern in renogram

    International Nuclear Information System (INIS)

    Tamaki, Nagara; Ishihara, Takashi; Mori, Toru; Bito, Sanae; Ito, Hidetomi

    1981-01-01

    In 204 routine renogram examinations using 131 I-iodohippurate, stepwise excretion curves were observed in 22 cases (14 with chronic thyroiditis, 4 with idiopathic edema, 3 with lower urinary tract disorders, and 1 with Bartter's syndrome). Such a phenomenon was observed in 74% of euthyroid edematous patients with chronic thyroiditis and 57% of patients with idiopathic edema. The stepwise pattern was considered to have certain correlations with spasm or increased peristalsis of the urinary tract through the studies of excretory urogram, butylscopolamine treated renogram, and regional renogram. In one of these edematous patients with chronic thyroiditis, this renogram pattern could not be reproduced after bed rest corresponding with the clinical evidence that physical rest reduce the edema. Thus, the stepwise excretory pattern in renogram seemed to be a useful indicator of the fluctuating edema in patients with chronic thyroiditis and idiopathic edema. (author)

  4. Cushing's syndrome: Stepwise approach to diagnosis

    Science.gov (United States)

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

    2011-01-01

    The projected prevalence of Cushing's syndrome (CS) inclusive of subclinical cases in the adult population ranges from 0.2–2% and it may no longer be considered as an orphan disease (2–3 cases/million/year). The recognition of CS by physicians is important for early diagnosis and treatment. Late-night salivary cortisol, dexamethasone suppressiontesti, or 24-h urine free cortisol are good screening tests. Positively screened cases need stepwise evaluation by an endocrinologist. This paper discusses the importance of screening for CS and suggests a stepwise diagnostic approach to a case of suspected hypercortisolism. PMID:22145134

  5. Studies on biamperometric determination of thorium using EDTA as titrant

    International Nuclear Information System (INIS)

    Jayachandran, Kavitha; Nair, P.R.; Noronha, D.M.; Xavier, Mary; Aggarwal, S.K.

    2009-01-01

    A method is described for the determination of thorium at sub milligram levels by EDTA complexometric titration using biamperometric end point detection. The methodology is based on the electroactive behaviour of EDTA observed at pH 2-3, suggesting a reversible electron transfer reaction at potential ≥ 200 mV applied between twin Pt electrodes. Accuracy and precision of better than 2% were obtained for thorium amounts in the 100-500 μg range. (author)

  6. Cushing's syndrome: Stepwise approach to diagnosis

    OpenAIRE

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

    2011-01-01

    The projected prevalence of Cushing′s syndrome (CS) inclusive of subclinical cases in the adult population ranges from 0.2-2% and it may no longer be considered as an orphan disease (2-3 cases/million/year). The recognition of CS by physicians is important for early diagnosis and treatment. Late-night salivary cortisol, dexamethasone suppressiontesti, or 24-h urine free cortisol are good screening tests. Positively screened cases need stepwise evaluation by an endocrinologist. This paper disc...

  7. Effects of stepwise gas combustion on NOx generation

    International Nuclear Information System (INIS)

    Woperane Seredi, A.; Szepesi, E.

    1999-01-01

    To decrease NO x emission from gas boilers, the combustion process of gas has been modified from continuous combustion to step-wise combustion. In this process the combustion temperature, the temperature peaks in the flame, the residence time of combustion products in the high-temperature zone and the oxygen partial pressure are changed advantageously. Experiments were performed using multistage burners, and the NO x emission was recorded. It was found that the air factor of the primary combustion space has a determining effect on the NO x reduction. (R.P.)

  8. Multiple-Objective Stepwise Calibration Using Luca

    Science.gov (United States)

    Hay, Lauren E.; Umemoto, Makiko

    2007-01-01

    This report documents Luca (Let us calibrate), a multiple-objective, stepwise, automated procedure for hydrologic model calibration and the associated graphical user interface (GUI). Luca is a wizard-style user-friendly GUI that provides an easy systematic way of building and executing a calibration procedure. The calibration procedure uses the Shuffled Complex Evolution global search algorithm to calibrate any model compiled with the U.S. Geological Survey's Modular Modeling System. This process assures that intermediate and final states of the model are simulated consistently with measured values.

  9. The application of X-ray fluorescence (XRF) method for the determination chemical composition of glass bath raw materials

    International Nuclear Information System (INIS)

    Werfel, Z.

    1974-01-01

    The estimation of determination accuracy of glass sand, limestone and dolomite compositions by the means of X-ray fluorescence method has been made. The most important advantage of XRF method application is short time of analysis. The preparation time of sample is not longer than 20 minutes, the analysis of single sample is about 1,5 minutes. The comparison of results of determinations by the means of XRF and complexometric methods have been given. (author)

  10. Stepwise approach to myopathy in systemic disease.

    Science.gov (United States)

    Chawla, Jasvinder

    2011-01-01

    Muscle diseases can constitute a large variety of both acquired and hereditary disorders. Myopathies in systemic disease results from several different disease processes including endocrine, inflammatory, paraneoplastic, infectious, drug- and toxin-induced, critical illness myopathy, metabolic, and myopathies with other systemic disorders. Patients with systemic myopathies often present acutely or sub acutely. On the other hand, familial myopathies or dystrophies generally present in a chronic fashion with exceptions of metabolic myopathies where symptoms on occasion can be precipitated acutely. Most of the inflammatory myopathies can have a chance association with malignant lesions; the incidence appears to be specifically increased only in patients with dermatomyositis. In dealing with myopathies associated with systemic illnesses, the focus will be on the acquired causes. Management is beyond the scope of this chapter. Prognosis is based upon the underlying cause and, most of the time, carries a good prognosis. In order to approach a patient with suspected myopathy from systemic disease, a stepwise approach is utilized.

  11. REGSTEP - stepwise multivariate polynomial regression with singular extensions

    International Nuclear Information System (INIS)

    Davierwalla, D.M.

    1977-09-01

    The program REGSTEP determines a polynomial approximation, in the least squares sense, to tabulated data. The polynomial may be univariate or multivariate. The computational method is that of stepwise regression. A variable is inserted into the regression basis if it is significant with respect to an appropriate F-test at a preselected risk level. In addition, should a variable already in the basis, become nonsignificant (again with respect to an appropriate F-test) after the entry of a new variable, it is expelled from the model. Thus only significant variables are retained in the model. Although written expressly to be incorporated into CORCOD, a code for predicting nuclear cross sections for given values of power, temperature, void fractions, Boron content etc. there is nothing to limit the use of REGSTEP to nuclear applications, as the examples demonstrate. A separate version has been incorporated into RSYST for the general user. (Auth.)

  12. FPGA Implementation of the stepwise shutdown system

    Energy Technology Data Exchange (ETDEWEB)

    Lotjonen, L.

    2012-07-01

    This report elaborates the design process of applications for field-programmable gate array (FPGA) devices. Brief introductions to EPGA technology and the design process are first given and then the design phases are walked through with the aid of a case study. FPGA is a programmable logic device that is programmed by the customer rather than the manufacturer. They are also usually re-programmable which enables updating their programming and otherwise modifying the design. There are also one-time programmable FPGAs that can be used when security issues require it. FPGA is said to be 'hardware designed like software', which means that the design process resembles software development but the end-product is considered a hardware application because the execution of the functions is entirely different from a microprocessor. This duality can give both the flexibility of software and the reliability of hardware. The FPGA design and verification and validation (V and V) methods for NPP safety systems have not yet matured because the technology is rather new in the field. Software development methods and stanfards can be used to some extent but the hardware aspects bring new challenges that cannot be tacled using purely software methods. International efforts are being made to development formal and consistent design and V and V methodology regulations for FPGA devices. A preventive safety function called Stepwise Shutdown System (SWS) was implemented on an Actel M1 IGLOO field-programmable gate array (FPGA) device. SWS is used to drive a process into a normal state if the process measurements deviate from the desired operating values. This can happen in case of process disturbances. The SWS implementation processfrom the reguirements to the functional device is elaborated. The design is tested via simulation and hardware testing. The case study is to be further expanded as a part of a master's thesis. (orig.)

  13. FPGA Implementation of the stepwise shutdown system

    International Nuclear Information System (INIS)

    Lotjonen, L.

    2012-01-01

    This report elaborates the design process of applications for field-programmable gate array (FPGA) devices. Brief introductions to EPGA technology and the design process are first given and then the design phases are walked through with the aid of a case study. FPGA is a programmable logic device that is programmed by the customer rather than the manufacturer. They are also usually re-programmable which enables updating their programming and otherwise modifying the design. There are also one-time programmable FPGAs that can be used when security issues require it. FPGA is said to be 'hardware designed like software', which means that the design process resembles software development but the end-product is considered a hardware application because the execution of the functions is entirely different from a microprocessor. This duality can give both the flexibility of software and the reliability of hardware. The FPGA design and verification and validation (V and V) methods for NPP safety systems have not yet matured because the technology is rather new in the field. Software development methods and standards can be used to some extent but the hardware aspects bring new challenges that cannot be tackled using purely software methods. International efforts are being made to development formal and consistent design and V and V methodology regulations for FPGA devices. A preventive safety function called Stepwise Shutdown System (SWS) was implemented on an Actel M1 IGLOO field-programmable gate array (FPGA) device. SWS is used to drive a process into a normal state if the process measurements deviate from the desired operating values. This can happen in case of process disturbances. The SWS implementation process from the requirements to the functional device is elaborated. The design is tested via simulation and hardware testing. The case study is to be further expanded as a part of a master's thesis. (orig.)

  14. Stepwise excavation may enhance pulp preservation in permanent teeth affected by dental caries

    DEFF Research Database (Denmark)

    Bjørndal, Lars

    2011-01-01

    ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Ways of enhancing pulp preservation by stepwise excavation-a systematic review. Hayashi M, Fujitani M, Yamaki C, Momoi Y. J Dent 2011;39(2):95-107. Epub 2010 Dec 3. REVIEWER: Lars Bjørndal, DDS, PhD, Dr Odont PURPOSE/QUESTION: To determine the clinical...

  15. A stepwise approach for defining the applicability domain of SAR and QSAR models

    DEFF Research Database (Denmark)

    Dimitrov, Sabcho; Dimitrova, Gergana; Pavlov, Todor

    2005-01-01

    A stepwise approach for determining the model applicability domain is proposed. Four stages are applied to account for the diversity and complexity of the current SAR/QSAR models, reflecting their mechanistic rationality (including metabolic activation of chemicals) and transparency. General para...

  16. The Performance of Step-Wise Group Screening Designs

    Directory of Open Access Journals (Sweden)

    M.M. Manene

    2005-06-01

    Full Text Available In this paper we evaluate the performance of step-wise group screening designs in which group-factors contain an equal number of factors in the initial step.  A usual assumption in group screening designs is that the directions of possible effects are known a-priori. In practice, however, this assumption is unreasonable. We shall examine step-wise group screening designs without errors in observations when this assumption is relaxed. We shall consider cancellations of effects within group-factors. The performance of step-wise group-screening designs shall then be compared with the performance of multistage group screening designs.

  17. Stepwise versus Hierarchical Regression: Pros and Cons

    Science.gov (United States)

    Lewis, Mitzi

    2007-01-01

    Multiple regression is commonly used in social and behavioral data analysis. In multiple regression contexts, researchers are very often interested in determining the "best" predictors in the analysis. This focus may stem from a need to identify those predictors that are supportive of theory. Alternatively, the researcher may simply be interested…

  18. Stepwise introduction of laparoscopic liver surgery: validation of guideline recommendations.

    Science.gov (United States)

    van der Poel, Marcel J; Huisman, Floor; Busch, Olivier R; Abu Hilal, Mohammad; van Gulik, Thomas M; Tanis, Pieter J; Besselink, Marc G

    2017-10-01

    Uncontrolled introduction of laparoscopic liver surgery (LLS) could compromise postoperative outcomes. A stepwise introduction of LLS combined with structured training is advised. This study aimed to evaluate the impact of such a stepwise introduction. A retrospective, single-center case series assessing short term outcomes of all consecutive LLS in the period November 2006-January 2017. The technique was implemented in a stepwise fashion. To evaluate the impact of this stepwise approach combined with structured training, outcomes of LLS before and after a laparoscopic HPB fellowship were compared. A total of 135 laparoscopic resections were performed. Overall conversion rate was 4% (n = 5), clinically relevant complication rate 13% (n = 18) and mortality 0.7% (n = 1). A significant increase in patients with major LLS, multiple liver resections, previous abdominal surgery, malignancies and lesions located in posterior segments was observed after the fellowship as well as a decrease in the use of hand-assistance. Increasing complexity in the post fellowship period was reflected by an increase in operating times, but without comprising other surgical outcomes. A stepwise introduction of LLS combined with structured training reduced the clinical impact of the learning curve, thereby confirming guideline recommendations. Copyright © 2017 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

  19. The Intramolecular Diels–Alder Reaction of Tryptamine-Derived Zincke Aldehydes Is a Stepwise Process

    OpenAIRE

    Pham, Hung V.; Martin, David B. C.; Vanderwal, Christopher D.; Houk, K. N.

    2012-01-01

    Computational studies show that the base-mediated intramolecular Diels–Alder of tryptamine-derived Zincke aldehydes, used as a key step in the synthesis of the Strychnos alkaloids norfluorocurarine and strychnine, proceeds via a stepwise pathway. The experimentally determined importance of a potassium counterion in the base is explained by its ability to preorganize the Zincke aldehyde diene in an s-cis conformation suitable to bicyclization. Computation also supports the thermodynamic import...

  20. Melanin fluorescence spectra by step-wise three photon excitation

    Science.gov (United States)

    Lai, Zhenhua; Kerimo, Josef; DiMarzio, Charles A.

    2012-03-01

    Melanin is the characteristic chromophore of human skin with various potential biological functions. Kerimo discovered enhanced melanin fluorescence by stepwise three-photon excitation in 2011. In this article, step-wise three-photon excited fluorescence (STPEF) spectrum between 450 nm -700 nm of melanin is reported. The melanin STPEF spectrum exhibited an exponential increase with wavelength. However, there was a probability of about 33% that another kind of step-wise multi-photon excited fluorescence (SMPEF) that peaks at 525 nm, shown by previous research, could also be generated using the same process. Using an excitation source at 920 nm as opposed to 830 nm increased the potential for generating SMPEF peaks at 525 nm. The SMPEF spectrum peaks at 525 nm photo-bleached faster than STPEF spectrum.

  1. Cushing′s syndrome: Stepwise approach to diagnosis

    Directory of Open Access Journals (Sweden)

    Anurag R Lila

    2011-01-01

    Full Text Available The projected prevalence of Cushing′s syndrome (CS inclusive of subclinical cases in the adult population ranges from 0.2-2% and it may no longer be considered as an orphan disease (2-3 cases/million/year. The recognition of CS by physicians is important for early diagnosis and treatment. Late-night salivary cortisol, dexamethasone suppressiontesti, or 24-h urine free cortisol are good screening tests. Positively screened cases need stepwise evaluation by an endocrinologist. This paper discusses the importance of screening for CS and suggests a stepwise diagnostic approach to a case of suspected hypercortisolism.

  2. Complexo-potentiometric determination of mercury (II) in chlormerodrin and mercuric chloride labelled with radioactive mercury

    International Nuclear Information System (INIS)

    Duek, E.E.

    1976-09-01

    A method is described for determining the amount of mercury (II) in radioactively labelled chlormerodrin and mercuric chloride. By measuring the absolute activity in an ionization chamber, the specific activity is therefore immediately obtained. The determination of Hg (II) is based on a complexometric titration. Because of method characteristics and speed convenience, the end point is observed by means of a pH-meter. A comparison is made with a determination performed by detecting the end point with color-change indicators. The error is estimated, and the results are statistically interpreted. (author) [es

  3. Stepwise dehydrogenation of ammonia on Fcc-Co surfaces: A DFT study

    Energy Technology Data Exchange (ETDEWEB)

    Ma, F.F.; Ma, S.H., E-mail: mash.phy@htu.edu.cn; Jiao, Z.Y.; Dai, X.Q.

    2017-05-31

    Highlights: • On Co surfaces, oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation on the Co surfaces. • Pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. • The dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces. • The species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom. - Abstract: The stepwise dehydrogenation of ammonia on clean and O-covered Co surfaces have been studied by performing density functional theory (DFT) calculations. It is found that the interaction of species NH{sub x} (x = 0–3) with the Co surfaces become stronger with its further dehydrogenation, and oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation. Specifically, pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. In contrast, the dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces, due to the high energy barriers. And present results demonstrate that the species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom.

  4. Improved model of the retardance in citric acid coated ferrofluids using stepwise regression

    Science.gov (United States)

    Lin, J. F.; Qiu, X. R.

    2017-06-01

    Citric acid (CA) coated Fe3O4 ferrofluids (FFs) have been conducted for biomedical application. The magneto-optical retardance of CA coated FFs was measured by a Stokes polarimeter. Optimization and multiple regression of retardance in FFs were executed by Taguchi method and Microsoft Excel previously, and the F value of regression model was large enough. However, the model executed by Excel was not systematic. Instead we adopted the stepwise regression to model the retardance of CA coated FFs. From the results of stepwise regression by MATLAB, the developed model had highly predictable ability owing to F of 2.55897e+7 and correlation coefficient of one. The average absolute error of predicted retardances to measured retardances was just 0.0044%. Using the genetic algorithm (GA) in MATLAB, the optimized parametric combination was determined as [4.709 0.12 39.998 70.006] corresponding to the pH of suspension, molar ratio of CA to Fe3O4, CA volume, and coating temperature. The maximum retardance was found as 31.712°, close to that obtained by evolutionary solver in Excel and a relative error of -0.013%. Above all, the stepwise regression method was successfully used to model the retardance of CA coated FFs, and the maximum global retardance was determined by the use of GA.

  5. Stepwise dehydrogenation of ammonia on Fcc-Co surfaces: A DFT study

    International Nuclear Information System (INIS)

    Ma, F.F.; Ma, S.H.; Jiao, Z.Y.; Dai, X.Q.

    2017-01-01

    Highlights: • On Co surfaces, oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation on the Co surfaces. • Pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. • The dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces. • The species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom. - Abstract: The stepwise dehydrogenation of ammonia on clean and O-covered Co surfaces have been studied by performing density functional theory (DFT) calculations. It is found that the interaction of species NH x (x = 0–3) with the Co surfaces become stronger with its further dehydrogenation, and oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation. Specifically, pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. In contrast, the dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces, due to the high energy barriers. And present results demonstrate that the species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom.

  6. An Original Stepwise Multilevel Logistic Regression Analysis of Discriminatory Accuracy

    DEFF Research Database (Denmark)

    Merlo, Juan; Wagner, Philippe; Ghith, Nermin

    2016-01-01

    BACKGROUND AND AIM: Many multilevel logistic regression analyses of "neighbourhood and health" focus on interpreting measures of associations (e.g., odds ratio, OR). In contrast, multilevel analysis of variance is rarely considered. We propose an original stepwise analytical approach that disting...

  7. MULGRES: a computer program for stepwise multiple regression analysis

    Science.gov (United States)

    A. Jeff Martin

    1971-01-01

    MULGRES is a computer program source deck that is designed for multiple regression analysis employing the technique of stepwise deletion in the search for most significant variables. The features of the program, along with inputs and outputs, are briefly described, with a note on machine compatibility.

  8. Stepwise radical cation Diels-Alder reaction via multiple pathways.

    Science.gov (United States)

    Shimizu, Ryo; Okada, Yohei; Chiba, Kazuhiro

    2018-01-01

    Herein we disclose the radical cation Diels-Alder reaction of aryl vinyl ethers by electrocatalysis, which is triggered by an oxidative SET process. The reaction clearly proceeds in a stepwise fashion, which is a rare mechanism in this class. We also found that two distinctive pathways, including "direct" and "indirect", are possible to construct the Diels-Alder adduct.

  9. Stepwise innovation adoption : a neglected concept in innovation research

    NARCIS (Netherlands)

    Huizingh, K.R.E.; Brand, M.J.

    2009-01-01

    Most innovation researchers tend to consider innovation adoption as a binary process, implying that companies have either adopted an innovation or not. In this paper we focus on e-commerce as an innovation that can be adopted stepwise. We distinguish between two levels of e-commerce, basic and

  10. Stepwise Decision Making for Long-Term Radioactive Waste Management

    International Nuclear Information System (INIS)

    Pescatore, Claudio; Vari, Anna

    2003-01-01

    Consideration is increasingly being given, in radioactive waste management (RWM), to concepts such as 'stepwise decision making' and 'adaptive staging' in which the public, and especially the local communities, are also meaningfully involved in the review and planning of developments. The key feature of these concepts is development by steps or stages that are reversible, within the limits of practicability and provided they meet the requirements of an acceptable safety case. Stepwise decisions are designed to provide reassurance that actions can be reversed if experience shows them to have adverse or unwanted effects. Stepwise decision making has thus come to the fore as being especially important for making progress for radioactive waste management in a manner which is acceptable to large sectors of society. Despite its early identification within the RWM community as an important means for reaching decision in which there is broad-based confidence, stepwise decision making has not been widely debated. Accepted guiding principles of any such process have not yet been formulated, its roots in empirical social science research have not been fully reviewed, nor the difficulties of its implementation analysed. This paper reviews the current developments regarding stepwise decision making in RWM with the aim to pinpoint where it stands, to highlight its societal dimension, to analyse its roots in social sciences, and to identify guiding principles and issues in implementation. It is observed that there is convergence between the approach taken by the practitioners of RWM and the indications received from field studies in social research, and that general guiding principles can be proposed at least as a basis for further discussion. A strong basis for dialogue across disciplines thus exists. General methodological issues are also identified. This paper was developed in the framework of the activities of the NEA Forum on Stakeholder Confidence, which is presented in a

  11. Characterization of vegetative and grain filling periods of winter wheat by stepwise regression procedure. II. Grain filling period

    Directory of Open Access Journals (Sweden)

    Pržulj Novo

    2011-01-01

    Full Text Available In wheat, rate and duration of dry matter accumulation and remobilization depend on genotype and growing conditions. The objective of this study was to determine the most appropriate polynomial regression of stepwise regression procedure for describing grain filling period in three winter wheat cultivars. The stepwise regression procedure showed that grain filling is a complex biological process and that it is difficult to offer a simple and appropriate polynomial equation that fits the pattern of changes in dry matter accumulation during the grain filling period, i.e., from anthesis to maximum grain weight, in winter wheat. If grain filling is to be represented with a high power polynomial, quartic and quintic equations showed to be most appropriate. In spite of certain disadvantages, a cubic equation of stepwise regression could be used for describing the pattern of winter wheat grain filling.

  12. Stepwise Diagnosis for Rotating Machinery Using Force Identification Approach

    Directory of Open Access Journals (Sweden)

    Shozo Kawamura

    2012-01-01

    Full Text Available Machine condition monitoring and diagnosis have become increasingly important, and the application of these processes has been widely investigated. The authors previously proposed a stepwise diagnosis method for a beam structure. In that method, the location of the abnormality is first estimated using the force identification approach, and then the cause of the abnormality is identified. In this study, the stepwise diagnosis method was improved specifically for rotating machinery. The applicability of the proposed method was checked by using the experimental data. In the case of a rotor system with unbalance, it was shown that the location of the abnormality and its severity could be identified, and, in the case of a rotor system with stationary rubbing, the location of the abnormality could be accurately identified. Therefore, it was confirmed that the proposed diagnostic method is feasible for actual application.

  13. Stepwise commissioning of a steam boiler with stability guarantees

    DEFF Research Database (Denmark)

    Johansen, Simon Vestergaard; Kallesøe, Carsten Skovmose; Bendtsen, Jan Dimon

    2016-01-01

    This paper aims to make the commissioning of an industrial MIMO controller more straightforward by gradually commissioning it from a set of SISO controllers, after the system has been started. For this purpose a stepwise commissioning strategy based on the Youla-Kucera parametrization has been de...... been commissioned from a SISO controller using the developed method on a real steam boiler and measurements show a clear performance improvement after transition....

  14. Stepwise classification of cancer samples using clinical and molecular data

    Directory of Open Access Journals (Sweden)

    Obulkasim Askar

    2011-10-01

    Full Text Available Abstract Background Combining clinical and molecular data types may potentially improve prediction accuracy of a classifier. However, currently there is a shortage of effective and efficient statistical and bioinformatic tools for true integrative data analysis. Existing integrative classifiers have two main disadvantages: First, coarse combination may lead to subtle contributions of one data type to be overshadowed by more obvious contributions of the other. Second, the need to measure both data types for all patients may be both unpractical and (cost inefficient. Results We introduce a novel classification method, a stepwise classifier, which takes advantage of the distinct classification power of clinical data and high-dimensional molecular data. We apply classification algorithms to two data types independently, starting with the traditional clinical risk factors. We only turn to relatively expensive molecular data when the uncertainty of prediction result from clinical data exceeds a predefined limit. Experimental results show that our approach is adaptive: the proportion of samples that needs to be re-classified using molecular data depends on how much we expect the predictive accuracy to increase when re-classifying those samples. Conclusions Our method renders a more cost-efficient classifier that is at least as good, and sometimes better, than one based on clinical or molecular data alone. Hence our approach is not just a classifier that minimizes a particular loss function. Instead, it aims to be cost-efficient by avoiding molecular tests for a potentially large subgroup of individuals; moreover, for these individuals a test result would be quickly available, which may lead to reduced waiting times (for diagnosis and hence lower the patients distress. Stepwise classification is implemented in R-package stepwiseCM and available at the Bioconductor website.

  15. Stepwise Procedure for Development and Validation of a Multipesticide Method

    Energy Technology Data Exchange (ETDEWEB)

    Ambrus, A. [Hungarian Food Safety Office, Budapest (Hungary)

    2009-07-15

    The stepwise procedure for development and the validation of so called multi-pesticide methods are described. Principles, preliminary actions, criteria for the selection of chromatographic separation, detection and performance verification of multi-pesticide methods are outlined. Also the long term repeatability and reproducibility, as well as the necessity for the documentation of laboratory work are highlighted. Appendix I hereof describes in detail the calculation of calibration parameters, whereas Appendix II focuses on the calculation of the significance of differences of concentrations obtained on two different separation columns. (author)

  16. Effects of constant and stepwise changes in temperature on the species abundance dynamics of four cladocera species

    Directory of Open Access Journals (Sweden)

    Verbitsky V. B.

    2011-09-01

    Full Text Available Laboratory experiments with natural zooplankton communities were carried out to study the effects of two contrasting temperature regimes: constant temperature (15, 20, and 25 °C and graded changes in temperature. The graded regime consisted of repeated sustained (three weeks controlled stepwise temperature changes of 5 or 10 °C within 15–25 °C on the population dynamics of four dominant species of lake littoral zooplankton, Daphnia longispina (Müller, 1785, Diaphanosoma brachyurum (Lievin, 1848, Simocephalus vetulus (Müller, 1776 and Chydorus sphaericus (Müller, 1785. The results show that controlled stepwise changes (positive or negative in temperature within the ranges of 15–20, 20–25, and 15–25 °C can exert either stimulating or inhibitory effect (direct or delayed on the development of D. longispina and S. vetulus populations. The development of D. brachyurum and Ch. sphaericus, both more steno-thermophile, was only stimulated by a stable elevated temperature (25 °C. These results support the previously formulated hypothesis that, in determining the ecological temperature optimum of a species within a natural community, it is not enough to define its optimum from constant, cyclic or random temperature fluctuations, but also from unidirectional stepwise changes in temperature. These stepwise changes may also induce prolonged or delayed effects.

  17. Enhanced eumelanin emission by stepwise three-photon excitation

    Science.gov (United States)

    Kerimo, Josef; Rajadhyaksha, Milind; DiMarzio, Charles A.

    2011-03-01

    Eumelanin fluorescence from Sepia officinalis and black human hair was activated with near-infrared radiation and multiphoton excitation. A third order multiphoton absorption by a step-wise process appears to be the underlying mechanism. The activation was caused by a photochemical process since it could not be reproduced by simple heating. Both fluorescence and brightfield imaging indicate the near-infrared irradiation caused photodamage to the eumelanin and the activated emission originated from the photodamaged region. At least two different components with about thousand-fold enhanced fluorescence were activated and could be distinguished by their excitation properties. One component was excited with wavelengths in the visible region and exhibited linear absorption dependence. The second component could be excited with near-infrared wavelengths and had a third order dependence on the laser power. The third order dependence is explained by a step-wise excited state absorption (ESA) process since it could be observed equally with the CW and femtosecond lasers. The new method for photoactivating the eumelanin fluorescence was used to map the melanin content in human hair.

  18. Stepwise Nanopore Evolution in One-Dimensional Nanostructures

    KAUST Repository

    Choi, Jang Wook

    2010-04-14

    We report that established simple lithium (Li) ion battery cycles can be used to produce nanopores inside various useful one-dimensional (1D) nanostructures such as zinc oxide, silicon, and silver nanowires. Moreover, porosities of these 1D nanomaterials can be controlled in a stepwise manner by the number of Li-battery cycles. Subsequent pore characterization at the end of each cycle allows us to obtain detailed snapshots of the distinct pore evolution properties in each material due to their different atomic diffusion rates and types of chemical bonds. Also, this stepwise characterization led us to the first observation of pore size increases during cycling, which can be interpreted as a similar phenomenon to Ostwald ripening in analogous nanoparticle cases. Finally, we take advantage of the unique combination of nanoporosity and 1D materials and demonstrate nanoporous silicon nanowires (poSiNWs) as excellent supercapacitor (SC) electrodes in high power operations compared to existing devices with activated carbon. © 2010 American Chemical Society.

  19. Estimating stepwise debromination pathways of polybrominated diphenyl ethers with an analogue Markov Chain Monte Carlo algorithm.

    Science.gov (United States)

    Zou, Yonghong; Christensen, Erik R; Zheng, Wei; Wei, Hua; Li, An

    2014-11-01

    A stochastic process was developed to simulate the stepwise debromination pathways for polybrominated diphenyl ethers (PBDEs). The stochastic process uses an analogue Markov Chain Monte Carlo (AMCMC) algorithm to generate PBDE debromination profiles. The acceptance or rejection of the randomly drawn stepwise debromination reactions was determined by a maximum likelihood function. The experimental observations at certain time points were used as target profiles; therefore, the stochastic processes are capable of presenting the effects of reaction conditions on the selection of debromination pathways. The application of the model is illustrated by adopting the experimental results of decabromodiphenyl ether (BDE209) in hexane exposed to sunlight. Inferences that were not obvious from experimental data were suggested by model simulations. For example, BDE206 has much higher accumulation at the first 30 min of sunlight exposure. By contrast, model simulation suggests that, BDE206 and BDE207 had comparable yields from BDE209. The reason for the higher BDE206 level is that BDE207 has the highest depletion in producing octa products. Compared to a previous version of the stochastic model based on stochastic reaction sequences (SRS), the AMCMC approach was determined to be more efficient and robust. Due to the feature of only requiring experimental observations as input, the AMCMC model is expected to be applicable to a wide range of PBDE debromination processes, e.g. microbial, photolytic, or joint effects in natural environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Design of stepwise screening for prediabetes and type 2 diabetes based on costs and cases detected.

    Science.gov (United States)

    de Graaf, Gimon; Postmus, Douwe; Bakker, Stephan J L; Buskens, Erik

    2015-09-01

    To provide insight into the trade-off between cost per case detected (CPCD) and the detection rate in questionnaire-based stepwise screening for impaired fasting glucose and undiagnosed type 2 diabetes. We considered a stepwise screening in which individuals whose risk score exceeds a predetermined cutoff value are invited for further blood glucose testing. Using individual patient data to determine questionnaire sensitivity and specificity and external sources to determine screening costs and patient response rates, we rolled back a decision tree to estimate the CPCD and the detection rate for all possible cutoffs on the questionnaire. We found a U-shaped relation between CPCD and detection rate, with high costs per case detected at very low and very high detection rates. Changes in patient response rates had a large impact on both the detection rate and the CPCD, whereas screening costs and questionnaire accuracy mainly impacted the CPCD. Our applied method makes it possible to identify a range of efficient cutoffs where higher detection rates can be achieved at an additional cost per detected patient. This enables decision makers to choose an optimal cutoff based on their willingness to pay for additional detected patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. A simple wet chemical method for the determination of cation stoichiometry of YBa2Cu3O7-d

    International Nuclear Information System (INIS)

    Sahasranaman, S.; Premila, M.; Sreedharan, O.M.

    1996-01-01

    A comprehensive wet chemical procedure for the rapid analysis of yttrium, barium and copper ions in dilute HNO 3 medium has been developed to facilitate a precise and accurate determination of cation non-stoichiometry in high temperature ceramic superconducting materials Y 1±x Ba 2±y Cu 3±z O 7-d . The ease of analysis for copper by electrogravimetry and of yttrium and barium by a complexometric titration of the same aliquot against complexone III using arsenazo I as the indicator under appropriate pH has been demonstrated with the help of individual standard solutions and with synthetic mixtures. (author)

  2. Development of a potentiometric EDTA method for determination of molybdenum. Use of the analysis for molybdenite concentrates

    Science.gov (United States)

    Khristova, R.; Vanmen, M.

    1986-01-01

    Based on considerations of principles and experimental data, the interference of sulfate ions in poteniometric titration of EDTA with FeCl3 was confirmed. The method of back complexometric titration of molybdenum of Nonova and Gasheva was improved by replacing hydrazine sulfate with hydrazine hydrochloride for reduction of Mo(VI) to Mo(V). The method can be used for one to tenths of mg of molybdenum with 0.04 mg standard deviation. The specific method of determination of molybdenum in molybdenite concentrates is presented.

  3. Development of a potentiometric EDTA method for determination of molybdenum. Use of the analysis for molybdenite concentrates

    International Nuclear Information System (INIS)

    Khristova, R.; Vanmen, M.

    1976-01-01

    Based on considerations of principles and experimental data, the interference of sulfate ions in poteniometric titration of EDTA with FeCl 3 was confirmed. The method of back complexometric titration of molybdenum of Nonova and Gasheva was improved by replacing hydrazine sulfate with hydrazine hydrochloride for reduction of Mo(VI) to Mo(V). The method can be used for one to tenths of mg of molybdenum with 0.04 mg standard deviation. The specific method of determination of molybdenum in molybdenite concentrates is presented

  4. The Swedish approach to spent fuel disposal - stepwise implementation

    International Nuclear Information System (INIS)

    Gustaffson, B.

    1997-01-01

    This presentation describes the stepwise implementation of direct disposal of spent fuel in Sweden. The present status regarding the technical development of the Swedish concept will be discussed as well the local site work made in co-operation with the affected and concerned municipalities. In this respect it should be noted that the siting work in some cases has caused heavy opposition and negative opinions. A brief review will also be given regarding the Aspo Hard Rock Laboratory. The objectives of this laboratory as well as the ongoing demo-project will be discussed. In order to give the symposium organizer a more broad view of the Swedish programme a number of recent papers has been compiled. Theses papers will be summarized in the presentation. (author). 4 tabs., 22 figs

  5. Better Care Teams: A Stepwise Skill Reinforcement Model.

    Science.gov (United States)

    Christopher, Beth-Anne; Grantner, Mary; Coke, Lola A; Wideman, Marilyn; Kwakwa, Francis

    2016-06-01

    The Building Healthy Urban Communities initiative presents a path for organizations partnering to improve patient outcomes with continuing education (CE) as a key component. Components of the CE initiative included traditional CE delivery formats with an essential element of adaptability and new methods, with rigorous evaluation over time that included evaluation prior to the course, immediately following the CE session, 6 to 8 weeks after the CE session, and then subsequent monthly "testlets." Outcome measures were designed to allow for ongoing adaptation of content, reinforcement of key learning objectives, and use of innovative concordant testing and retrieval practice techniques. The results after 1 year of programming suggest the stepwise skill reinforcement model is effective for learning and is an efficient use of financial and human resources. More important, its design is one that could be adopted at low cost by organizations willing to work in close partnership. J Contin Educ Nurs. 2016;47(6):283-288. Copyright 2016, SLACK Incorporated.

  6. Stepwise transformation behavior of the strain-induced martensitic transformation in a metastable stainless steel

    International Nuclear Information System (INIS)

    Hedstroem, Peter; Lienert, Ulrich; Almer, Jon; Oden, Magnus

    2007-01-01

    In situ high-energy X-ray diffraction during tensile loading has been used to investigate the evolution of lattice strains and the accompanying strain-induced martensitic transformation in cold-rolled sheets of a metastable stainless steel. At high applied strains the transformation to α-martensite occurs in stepwise bursts. These stepwise transformation events are correlated with stepwise increased lattice strains and peak broadening in the austenite phase. The stepwise transformation arises from growth of α-martensite embryos by autocatalytic transformation

  7. Stillbirth evaluation: a stepwise assessment of placental pathology and autopsy.

    Science.gov (United States)

    Miller, Emily S; Minturn, Lucy; Linn, Rebecca; Weese-Mayer, Debra E; Ernst, Linda M

    2016-01-01

    The American Congress of Obstetricians and Gynecologists places special emphasis on autopsy as one of the most important tests for evaluation of stillbirth. Despite a recommendation of an autopsy, many families will decline the autopsy based on religious/cultural beliefs, fear of additional suffering for the child, or belief that no additional information will be obtained or of value. Further, many obstetric providers express a myriad of barriers limiting their recommendation for a perinatal autopsy despite their understanding of its value. Consequently, perinatal autopsy rates have been declining. Without the information provided by an autopsy, many women are left with unanswered questions regarding cause of death for their fetus and without clear management strategies to reduce the risk of stillbirth in future pregnancies. To avoid this scenario, it is imperative that clinicians are knowledgeable about the benefit of autopsy so they can provide clear information on its diagnostic utility and decrease potential barriers; in so doing the obstetrician can ensure that each family has the necessary information to make an informed decision. We sought to quantify the contribution of placental pathologic examination and autopsy in identifying a cause of stillbirth and to identify how often clinical management is modified due to each result. This is a cohort study of all cases of stillbirth from 2009 through 2013 at a single tertiary care center. Records were reviewed in a stepwise manner: first the clinical history and laboratory results, then the placental pathologic evaluation, and finally the autopsy. At each step, a cause of death and the certainty of that etiology were coded. Clinical changes that would be recommended by information available at each step were also recorded. Among the 144 cases of stillbirth examined, 104 (72%) underwent autopsy and these cases constitute the cohort of study. The clinical and laboratory information alone identified a cause of death

  8. Order Selection for General Expression of Nonlinear Autoregressive Model Based on Multivariate Stepwise Regression

    Science.gov (United States)

    Shi, Jinfei; Zhu, Songqing; Chen, Ruwen

    2017-12-01

    An order selection method based on multiple stepwise regressions is proposed for General Expression of Nonlinear Autoregressive model which converts the model order problem into the variable selection of multiple linear regression equation. The partial autocorrelation function is adopted to define the linear term in GNAR model. The result is set as the initial model, and then the nonlinear terms are introduced gradually. Statistics are chosen to study the improvements of both the new introduced and originally existed variables for the model characteristics, which are adopted to determine the model variables to retain or eliminate. So the optimal model is obtained through data fitting effect measurement or significance test. The simulation and classic time-series data experiment results show that the method proposed is simple, reliable and can be applied to practical engineering.

  9. Stepwise development of hematopoietic stem cells from embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Kenji Matsumoto

    Full Text Available The cellular ontogeny of hematopoietic stem cells (HSCs remains poorly understood because their isolation from and their identification in early developing small embryos are difficult. We attempted to dissect early developmental stages of HSCs using an in vitro mouse embryonic stem cell (ESC differentiation system combined with inducible HOXB4 expression. Here we report the identification of pre-HSCs and an embryonic type of HSCs (embryonic HSCs as intermediate cells between ESCs and HSCs. Both pre-HSCs and embryonic HSCs were isolated by their c-Kit(+CD41(+CD45(- phenotype. Pre-HSCs did not engraft in irradiated adult mice. After co-culture with OP9 stromal cells and conditional expression of HOXB4, pre-HSCs gave rise to embryonic HSCs capable of engraftment and long-term reconstitution in irradiated adult mice. Blast colony assays revealed that most hemangioblast activity was detected apart from the pre-HSC population, implying the early divergence of pre-HSCs from hemangioblasts. Gene expression profiling suggests that a particular set of transcripts closely associated with adult HSCs is involved in the transition of pre-HSC to embryonic HSCs. We propose an HSC developmental model in which pre-HSCs and embryonic HSCs sequentially give rise to adult types of HSCs in a stepwise manner.

  10. Super-resolution fluorescence microscopy by stepwise optical saturation

    Science.gov (United States)

    Zhang, Yide; Nallathamby, Prakash D.; Vigil, Genevieve D.; Khan, Aamir A.; Mason, Devon E.; Boerckel, Joel D.; Roeder, Ryan K.; Howard, Scott S.

    2018-01-01

    Super-resolution fluorescence microscopy is an important tool in biomedical research for its ability to discern features smaller than the diffraction limit. However, due to its difficult implementation and high cost, the super-resolution microscopy is not feasible in many applications. In this paper, we propose and demonstrate a saturation-based super-resolution fluorescence microscopy technique that can be easily implemented and requires neither additional hardware nor complex post-processing. The method is based on the principle of stepwise optical saturation (SOS), where M steps of raw fluorescence images are linearly combined to generate an image with a M-fold increase in resolution compared with conventional diffraction-limited images. For example, linearly combining (scaling and subtracting) two images obtained at regular powers extends the resolution by a factor of 1.4 beyond the diffraction limit. The resolution improvement in SOS microscopy is theoretically infinite but practically is limited by the signal-to-noise ratio. We perform simulations and experimentally demonstrate super-resolution microscopy with both one-photon (confocal) and multiphoton excitation fluorescence. We show that with the multiphoton modality, the SOS microscopy can provide super-resolution imaging deep in scattering samples. PMID:29675306

  11. Pathways of DNA unlinking: A story of stepwise simplification.

    Science.gov (United States)

    Stolz, Robert; Yoshida, Masaaki; Brasher, Reuben; Flanner, Michelle; Ishihara, Kai; Sherratt, David J; Shimokawa, Koya; Vazquez, Mariel

    2017-09-29

    In Escherichia coli DNA replication yields interlinked chromosomes. Controlling topological changes associated with replication and returning the newly replicated chromosomes to an unlinked monomeric state is essential to cell survival. In the absence of the topoisomerase topoIV, the site-specific recombination complex XerCD- dif-FtsK can remove replication links by local reconnection. We previously showed mathematically that there is a unique minimal pathway of unlinking replication links by reconnection while stepwise reducing the topological complexity. However, the possibility that reconnection preserves or increases topological complexity is biologically plausible. In this case, are there other unlinking pathways? Which is the most probable? We consider these questions in an analytical and numerical study of minimal unlinking pathways. We use a Markov Chain Monte Carlo algorithm with Multiple Markov Chain sampling to model local reconnection on 491 different substrate topologies, 166 knots and 325 links, and distinguish between pathways connecting a total of 881 different topologies. We conclude that the minimal pathway of unlinking replication links that was found under more stringent assumptions is the most probable. We also present exact results on unlinking a 6-crossing replication link. These results point to a general process of topology simplification by local reconnection, with applications going beyond DNA.

  12. Stepwise Analysis of Differential Item Functioning Based on Multiple-Group Partial Credit Model.

    Science.gov (United States)

    Muraki, Eiji

    1999-01-01

    Extended an Item Response Theory (IRT) method for detection of differential item functioning to the partial credit model and applied the method to simulated data using a stepwise procedure. Then applied the stepwise DIF analysis based on the multiple-group partial credit model to writing trend data from the National Assessment of Educational…

  13. A stepwise procedure for science communication in the field

    Science.gov (United States)

    Nisancioglu, Kerim; Paasche, Øyvind

    2017-04-01

    Communicating and disseminating earth science to laypersons, high-school students and their teachers are becoming increasingly important considering the overwhelming impact human civilization have on the planet. One of the main challenges with this type of dissemination arises from the cross-disciplinary nature of the Earth system as it encompasses anything from cloud physics to the geological evidence of ice ages being played out on millennial time scales. During the last four years we have tested and developed an approach referred to as «Turspor» which can be translated to 'Trail Tracks'. The ambition with "Turspor" is to inspire participants to seek in-depth knowledge relating to observations of features made in the field (glacial moraines, active permafrost, clouds, winds and so forth) as we have come to learn that observations made in the field enhances students capability to grasp the bare essentials related to the phenomena in question. By engaging master and PhD students in the process we create a platform where students can improve their teaching and communicative skills through a stepwise procedure. The initial concept was tested on 35 high school students during the summer of 2012 in the mountainous area of Snøheim on Dovre, Southern Norway. Before the arrival of the high school students, the university students prepared one page written summaries describing relevant geological or meteorological features and trained on how to best disseminate a basic scientific understanding of these. Specific examples were patterned ground caused by permafrost, glacier flour, katabatic winds, and equilibrium line altitude of glaciers. Based on the success of the program over the past 4 years with field trips together with local schools, we are in the process of developing the concept to be offered as a course at the master and PhD level, including a week of training in didactics applied to topics in the geosciences as well as practical training in the field. The

  14. Stepwise multi-criteria optimization for robotic radiosurgery

    International Nuclear Information System (INIS)

    Schlaefer, A.; Schweikard, A.

    2008-01-01

    Achieving good conformality and a steep dose gradient around the target volume remains a key aspect of radiosurgery. Clearly, this involves a trade-off between target coverage, conformality of the dose distribution, and sparing of critical structures. Yet, image guidance and robotic beam placement have extended highly conformal dose delivery to extracranial and moving targets. Therefore, the multi-criteria nature of the optimization problem becomes even more apparent, as multiple conflicting clinical goals need to be considered coordinate to obtain an optimal treatment plan. Typically, planning for robotic radiosurgery is based on constrained optimization, namely linear programming. An extension of that approach is presented, such that each of the clinical goals can be addressed separately and in any sequential order. For a set of common clinical goals the mapping to a mathematical objective and a corresponding constraint is defined. The trade-off among the clinical goals is explored by modifying the constraints and optimizing a simple objective, while retaining feasibility of the solution. Moreover, it becomes immediately obvious whether a desired goal can be achieved and where a trade-off is possible. No importance factors or predefined prioritizations of clinical goals are necessary. The presented framework forms the basis for interactive and automated planning procedures. It is demonstrated for a sample case that the linear programming formulation is suitable to search for a clinically optimal treatment, and that the optimization steps can be performed quickly to establish that a Pareto-efficient solution has been found. Furthermore, it is demonstrated how the stepwise approach is preferable compared to modifying importance factors

  15. Traumatic eye ball luxation: A stepwise approach to globe salvage

    Directory of Open Access Journals (Sweden)

    Himika Gupta

    2017-10-01

    Full Text Available Craniofacial trauma is often associated with orbital and ocular injuries. We report a case of a 21-year-old male with motor vehicular accident, orbital roof blow-in fracture, cerebrospinal fluid (CSF leak, and left sided globe luxation with corneal abrasion and complete conjunctival denuding. The patient was managed by a multispeciality team and the eyeball was protected by amniotic membrane graft (AMG biological dressing with novel use of inverted sterile metallic bowl as mechanical protection till the patient stabilized. During surgery, eyeball was reposited and ocular surface was reconstructed using amniotic membrane and symblepharon ring. Surgical correction and plating of the facial fractures and dural repair with autologus tensor fascia lata was done. Post surgery ocular surface was intact, ocular motility was well preserved and the globe was prephthisical. Traumatic eyeball luxation is a rare, but dramatic presentation which may occur in a blow in fracture when the intra orbital volume reduces and expels the eye ball out of the socket. This may be associated with extra ocular muscle rupture or optic nerve avulsion. The visual prognosis is nil in majority cases. However, the management is targeted towards globe preservation in view of psychological benefit and ease of cosmetic or prosthetic rehabilitation. Knowing the mechanism of luxation helps to plan the management. A stepwise approach for globe salvage is recommended. Team efforts to take care of various morbidities with special steps to safeguard the eye help to optimize outcomes. Keywords: Traumatic eyeball luxation, Blow in orbital fractures, Amniotic membrane graft for ocular surface, Globe reposition

  16. Step-wise pulling protocols for non-equilibrium dynamics

    Science.gov (United States)

    Ngo, Van Anh

    The fundamental laws of thermodynamics and statistical mechanics, and the deeper understandings of quantum mechanics have been rebuilt in recent years. It is partly because of the increasing power of computing resources nowadays, that allow shedding direct insights into the connections among the thermodynamics laws, statistical nature of our world, and the concepts of quantum mechanics, which have not yet been understood. But mostly, the most important reason, also the ultimate goal, is to understand the mechanisms, statistics and dynamics of biological systems, whose prevailing non-equilibrium processes violate the fundamental laws of thermodynamics, deviate from statistical mechanics, and finally complicate quantum effects. I believe that investigations of the fundamental laws of non-equilibrium dynamics will be a frontier research for at least several more decades. One of the fundamental laws was first discovered in 1997 by Jarzynski, so-called Jarzynski's Equality. Since then, different proofs, alternative descriptions of Jarzynski's Equality, and its further developments and applications have been quickly accumulated. My understandings, developments and applications of an alternative theory on Jarzynski's Equality form the bulk of this dissertation. The core of my theory is based on stepwise pulling protocols, which provide deeper insight into how fluctuations of reaction coordinates contribute to free-energy changes along a reaction pathway. We find that the most optimal pathways, having the largest contribution to free-energy changes, follow the principle of detailed balance. This is a glimpse of why the principle of detailed balance appears so powerful for sampling the most probable statistics of events. In a further development on Jarzynski's Equality, I have been trying to use it in the formalism of diagonal entropy to propose a way to extract useful thermodynamic quantities such temperature, work and free-energy profiles from far

  17. Stepwise development of MAIT cells in mouse and human.

    Directory of Open Access Journals (Sweden)

    Emmanuel Martin

    2009-03-01

    Full Text Available Mucosal-associated invariant T (MAIT cells display two evolutionarily conserved features: an invariant T cell receptor (TCRalpha (iTCRalpha chain and restriction by the nonpolymorphic class Ib major histocompatibility complex (MHC molecule, MHC-related molecule 1 (MR1. MR1 expression on thymus epithelial cells is not necessary for MAIT cell development but their accumulation in the gut requires MR1 expressing B cells and commensal flora. MAIT cell development is poorly known, as these cells have not been found in the thymus so far. Herein, complementary human and mouse experiments using an anti-humanValpha7.2 antibody and MAIT cell-specific iTCRalpha and TCRbeta transgenic mice in different genetic backgrounds show that MAIT cell development is a stepwise process, with an intra-thymic selection followed by peripheral expansion. Mouse MAIT cells are selected in an MR1-dependent manner both in fetal thymic organ culture and in double iTCRalpha and TCRbeta transgenic RAG knockout mice. In the latter mice, MAIT cells do not expand in the periphery unless B cells are added back by adoptive transfer, showing that B cells are not required for the initial thymic selection step but for the peripheral accumulation. In humans, contrary to natural killer T (NKT cells, MAIT cells display a naïve phenotype in the thymus as well as in cord blood where they are in low numbers. After birth, MAIT cells acquire a memory phenotype and expand dramatically, up to 1%-4% of blood T cells. Finally, in contrast with NKT cells, human MAIT cell development is independent of the molecular adaptor SAP. Interestingly, mouse MAIT cells display a naïve phenotype and do not express the ZBTB16 transcription factor, which, in contrast, is expressed by NKT cells and the memory human MAIT cells found in the periphery after birth. In conclusion, MAIT cells are selected by MR1 in the thymus on a non-B non-T hematopoietic cell, and acquire a memory phenotype and expand in the

  18. Stepwise mitigation of the Macesnik landslide, N Slovenia

    Directory of Open Access Journals (Sweden)

    M. Mikoš

    2005-01-01

    the landslide movement starting from the slide plane towards its surface. Due to the length of the landslide and its longitudinal geometry it will be divided into several sections, and the mitigation works will be executed consecutively in phases. Such an approach proved effective in the 800 m long uppermost section of the landslide, where 3 parallel deep drain trenches (250 m long, 8 to 12 m deep were executed in the autumn of 2003. The reduction of the movements in 2004 enabled the construction of two 5 m wide and 22 m deep reinforced concrete shafts, finished in early 2005. In Slovenia, this sort of support construction, known from road construction, was used for the first time for landslide mitigation. The monitoring results show that the landslide displacements have been drastically reduced to less than 1 cm/day. As a part of the stepwise mitigation of the Macesnik landslide, further reinforced concrete shafts are to be constructed in the middle section of the landslide to support the road crossing the landslide. At the landslide toe, a support construction is planned to prevent further landslide advancement, and its type is still to be defined during the procedure of adopting a detailed plan of national importance for the Macesnik landslide.

  19. Stepwise kinetic equilibrium models of quantitative polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Cobbs Gary

    2012-08-01

    Full Text Available Abstract Background Numerous models for use in interpreting quantitative PCR (qPCR data are present in recent literature. The most commonly used models assume the amplification in qPCR is exponential and fit an exponential model with a constant rate of increase to a select part of the curve. Kinetic theory may be used to model the annealing phase and does not assume constant efficiency of amplification. Mechanistic models describing the annealing phase with kinetic theory offer the most potential for accurate interpretation of qPCR data. Even so, they have not been thoroughly investigated and are rarely used for interpretation of qPCR data. New results for kinetic modeling of qPCR are presented. Results Two models are presented in which the efficiency of amplification is based on equilibrium solutions for the annealing phase of the qPCR process. Model 1 assumes annealing of complementary targets strands and annealing of target and primers are both reversible reactions and reach a dynamic equilibrium. Model 2 assumes all annealing reactions are nonreversible and equilibrium is static. Both models include the effect of primer concentration during the annealing phase. Analytic formulae are given for the equilibrium values of all single and double stranded molecules at the end of the annealing step. The equilibrium values are then used in a stepwise method to describe the whole qPCR process. Rate constants of kinetic models are the same for solutions that are identical except for possibly having different initial target concentrations. Analysis of qPCR curves from such solutions are thus analyzed by simultaneous non-linear curve fitting with the same rate constant values applying to all curves and each curve having a unique value for initial target concentration. The models were fit to two data sets for which the true initial target concentrations are known. Both models give better fit to observed qPCR data than other kinetic models present in the

  20. Stepwise kinetic equilibrium models of quantitative polymerase chain reaction.

    Science.gov (United States)

    Cobbs, Gary

    2012-08-16

    Numerous models for use in interpreting quantitative PCR (qPCR) data are present in recent literature. The most commonly used models assume the amplification in qPCR is exponential and fit an exponential model with a constant rate of increase to a select part of the curve. Kinetic theory may be used to model the annealing phase and does not assume constant efficiency of amplification. Mechanistic models describing the annealing phase with kinetic theory offer the most potential for accurate interpretation of qPCR data. Even so, they have not been thoroughly investigated and are rarely used for interpretation of qPCR data. New results for kinetic modeling of qPCR are presented. Two models are presented in which the efficiency of amplification is based on equilibrium solutions for the annealing phase of the qPCR process. Model 1 assumes annealing of complementary targets strands and annealing of target and primers are both reversible reactions and reach a dynamic equilibrium. Model 2 assumes all annealing reactions are nonreversible and equilibrium is static. Both models include the effect of primer concentration during the annealing phase. Analytic formulae are given for the equilibrium values of all single and double stranded molecules at the end of the annealing step. The equilibrium values are then used in a stepwise method to describe the whole qPCR process. Rate constants of kinetic models are the same for solutions that are identical except for possibly having different initial target concentrations. Analysis of qPCR curves from such solutions are thus analyzed by simultaneous non-linear curve fitting with the same rate constant values applying to all curves and each curve having a unique value for initial target concentration. The models were fit to two data sets for which the true initial target concentrations are known. Both models give better fit to observed qPCR data than other kinetic models present in the literature. They also give better estimates of

  1. Stepwise radiofrequency ablation of Barrett's esophagus preserves esophageal inner diameter, compliance, and motility

    NARCIS (Netherlands)

    Beaumont, H.; Gondrie, J. J.; McMahon, B. P.; Pouw, R. E.; Gregersen, H.; Bergman, J. J.; Boeckxstaens, G. E.

    2009-01-01

    Background and aim: Stepwise endoscopic circumferential and focal radiofrequency ablation is safe and effective for the eradication of Barrett's esophagus. In contrast to other techniques, radiofrequency ablation appears to avoid significant esophageal scarring or stenosis. Our aim was to evaluate

  2. Concerted and stepwise mechanisms in cycloaddition reactions: potential surfaces and isotope effects

    International Nuclear Information System (INIS)

    Houk, K.N.; Yi Li; Storer, Joey; Raimondi, Laura; Beno, Brett

    1994-01-01

    CASSCF/6-31G * calculations have been performed on concerted and stepwise Diels-Alder reactions of butadiene with ethene, the dimerization of butadiene, and the dimerization of cyclobutadiene. The relative energies of concerted and stepwise mechanisms are compared, and the factors influencing these ''energies of concert'' are discussed. The comparison of calculated isotope effects to experimental data provides support for theoretical results. (Author)

  3. Productivity Enhancement of Solar Still with PV Powered Heating Coil and Chamber Step-Wise Basin

    Directory of Open Access Journals (Sweden)

    Salah Abdallah

    2018-03-01

    Full Text Available There is a strong need to improve the productivity of single slope solar still. PV generator powered electrical heater and chamber step-wise design were introduced to the conventional solar still. An experimental study was performed to investigate the effect of adding the above mentioned modifications on the output parameters of the modified solar still. The inclusion of PV-powered heating coil and chamber step-wise design enhanced the productivity of distiller by up to 1098%.

  4. Stepwise magnetic-geochemical approach for efficient assessment of heavy metal polluted sites

    Science.gov (United States)

    Appel, E.; Rösler, W.; Ojha, G.

    2012-04-01

    Previous studies have shown that magnetometry can outline the distribution of fly ash deposition in the surroundings of coal-burning power plants and steel industries. Especially the easy-to-measure magnetic susceptibility (MS) is capable to act as a proxy for heavy metal (HM) pollution caused by such kind of point source pollution. Here we present a demonstration project around the coal-burning power plant complex "Schwarze Pumpe" in eastern Germany. Before reunification of West and East Germany huge amounts of HM pollutants were emitted from the "Schwarze Pumpe" into the environment by both fly ash emission and dumped clinker. The project has been conducted as part of the TASK Centre of Competence which aims at bringing new innovative techniques closer to the market. Our project combines in situ and laboratory MS measurements and HM analyses in order to demonstrate the efficiency of a stepwise approach for site assessment of HM pollution around point sources of fly-ash emission and deposition into soil. The following scenario is played through: We assume that the "true" spatial distribution of HM pollution (given by the pollution load index PLI comprising Fe, Zn, Pb, and Cu) is represented by our entire set of 85 measured samples (XRF analyses) from forest sites around the "Schwarze Pumpe". Surface MS data (collected with a Bartington MS2D) and in situ vertical MS sections (logged by an SM400 instrument) are used to determine a qualitative overview of potentially higher and lower polluted areas. A suite of spatial HM distribution maps obtained by random selections of 30 out of the 85 analysed sites is compared to the HM map obtained from a targeted 30-sites-selection based on pre-information from the MS results. The PLI distribution map obtained from the targeted 30-sites-selection shows all essential details of the "true" pollution map, while the different random 30-sites-selections miss important features. This comparison shows that, for the same cost

  5. A method for the selection of a functional form for a thermodynamic equation of state using weighted linear least squares stepwise regression

    Science.gov (United States)

    Jacobsen, R. T.; Stewart, R. B.; Crain, R. W., Jr.; Rose, G. L.; Myers, A. F.

    1976-01-01

    A method was developed for establishing a rational choice of the terms to be included in an equation of state with a large number of adjustable coefficients. The methods presented were developed for use in the determination of an equation of state for oxygen and nitrogen. However, a general application of the methods is possible in studies involving the determination of an optimum polynomial equation for fitting a large number of data points. The data considered in the least squares problem are experimental thermodynamic pressure-density-temperature data. Attention is given to a description of stepwise multiple regression and the use of stepwise regression in the determination of an equation of state for oxygen and nitrogen.

  6. Theory favors a stepwise mechanism of porphyrin degradation by a ferric hydroperoxide model of the active species of heme oxygenase.

    Science.gov (United States)

    Kumar, Devesh; de Visser, Samuël P; Shaik, Sason

    2005-06-08

    The report uses density functional theory to address the mechanism of heme degradation by the enzyme heme oxygenase (HO) using a model ferric hydroperoxide complex. HO is known to trap heme molecules and degrade them to maintain iron homeostasis in the biosystem. The degradation is initiated by complexation of the heme, then formation of the iron-hydroperoxo species, which subsequently oxidizes the meso position of the porphyrin by hydroxylation, thereby enabling eventually the cleavage of the porphyrin ring. Kinetic isotope effect studies indicate that the mechanism is assisted by general acid catalysis, via a chain of water molecules, and that all the events occur in concert. However, previous theoretical treatments indicated that the concerted mechanism has a high barrier, much higher than an alternative mechanism that is initiated by O-O bond homolysis of iron-hydroperoxide. The present contribution studies the stepwise and concerted acid-catalyzed mechanisms using H(3)O(+)(H(2)O)(n)(), n = 0-2. The effect of the acid strength is tested using the H(4)N(+)(H(2)O)(2) cluster and a fully protonated ferric hydroperoxide. All the calculations show that a stepwise mechanism that involves proton relay and O-O homolysis, in the rate-determining step, has a much lower barrier (>10 kcal/mol) than the corresponding fully concerted mechanism. The best fit of the calculated solvent kinetic isotope effect, to the experimental data, is obtained for the H(3)O(+)(H(2)O)(2) cluster. The calculated alpha-deuterium secondary kinetic isotope effect is inverse (0.95-0.98), but much less so than the experimental value (0.7). Possible reasons for this quantitative difference are discussed. Some probes are suggested that may enable experiment to distinguish the stepwise from the concerted mechanism.

  7. Noble gases from solar energetic particles revealed by closed system stepwise etching of lunar soil minerals

    International Nuclear Information System (INIS)

    Wieler, R.; Baur, H.; Signer, P.

    1986-01-01

    He, Ne, and Ar abundances and isotopic ratios in plagioclase and pyroxene separates from lunar soils were determined using a closed system stepwise etching technique. This method of noble gas release allows one to separate solar wind (SW) noble gases from those implanted as solar energetic particles (SEP). SEP-Ne with 20 Ne/ 22 Ne = 11.3 +- 0.3 is present in all samples studied. The abundances of SEP-Ne are 2-4 orders of magnitude too high to be explained exclusively as implanted solar flare gas. The major part of SEP-Ne possibly originates from solar 'suprathermal ions' with energies < 0.1 MeV/amu. The isotopic composition of Ne in these lower energy SEP is, however, probably identical to that of real flare Ne. The suggestion that SEP-Ne might have the same isotopic composition as planetary Ne and thus possibly represent an unfractionated sample of solar Ne is not tenable. SW-Ne retained in plagioclase and pyroxene is less fractionated than has been deduced by total fusion analyses. Ne-B is a mixture of SW-Ne and SEP-Ne rather than fractionated SW-Ne. In contrast to SEP-Ne, SEP-Ar has probably a very similar composition as SW-Ar. (author)

  8. Automation of peak-tracking analysis of stepwise perturbed NMR spectra

    Energy Technology Data Exchange (ETDEWEB)

    Banelli, Tommaso; Vuano, Marco [Università di Udine, Dipartimento di Area Medica (Italy); Fogolari, Federico [INBB (Italy); Fusiello, Andrea [Università di Udine, Dipartimento Politecnico di Ingegneria e Architettura (Italy); Esposito, Gennaro [INBB (Italy); Corazza, Alessandra, E-mail: alessandra.corazza@uniud.it [Università di Udine, Dipartimento di Area Medica (Italy)

    2017-02-15

    We describe a new algorithmic approach able to automatically pick and track the NMR resonances of a large number of 2D NMR spectra acquired during a stepwise variation of a physical parameter. The method has been named Trace in Track (TinT), referring to the idea that a gaussian decomposition traces peaks within the tracks recognised through 3D mathematical morphology. It is capable of determining the evolution of the chemical shifts, intensity and linewidths of each tracked peak.The performances obtained in term of track reconstruction and correct assignment on realistic synthetic spectra were high above 90% when a noise level similar to that of experimental data were considered. TinT was applied successfully to several protein systems during a temperature ramp in isotope exchange experiments. A comparison with a state-of-the-art algorithm showed promising results for great numbers of spectra and low signal to noise ratios, when the graduality of the perturbation is appropriate. TinT can be applied to different kinds of high throughput chemical shift mapping experiments, with quasi-continuous variations, in which a quantitative automated recognition is crucial.

  9. Determination of Sc and Th in ScI3-NaI-ThI4 sample

    International Nuclear Information System (INIS)

    Yuan Hui; Yang Zhihong

    1999-01-01

    Determination of Sc and Th in ScI 3 -NaI-ThI 4 sample is studied by X-ray fluorescence and complexometry. The effect of working condition of Sc on X-ray fluorescence spectrometer and different sample-making method on the determination of Sc and Th are studied experimentally. The X-ray fluorescence analysis of determination of Sc and Th is developed by polyester film sample-making technique, the measuring precision of Sc and Th is better than 4%. The effect of acidity and temperature on the determining end point of titration is obvious. The results of different complexometric methods are compared. The precision of Sc and Th is less than 2% by comlexometry, it is fit for the routine analysis of ScI 3 -NaI-ThI 4 sample

  10. Development and Application of a Stepwise Assessment Process for Rational Redesign of Sequential Skills-Based Courses.

    Science.gov (United States)

    Gallimore, Casey E; Porter, Andrea L; Barnett, Susanne G

    2016-10-25

    Objective. To develop and apply a stepwise process to assess achievement of course learning objectives related to advanced pharmacy practice experiences (APPEs) preparedness and inform redesign of sequential skills-based courses. Design. Four steps comprised the assessment and redesign process: (1) identify skills critical for APPE preparedness; (2) utilize focus groups and course evaluations to determine student competence in skill performance; (3) apply course mapping to identify course deficits contributing to suboptimal skill performance; and (4) initiate course redesign to target exposed deficits. Assessment. Focus group participants perceived students were least prepared for skills within the Accreditation Council for Pharmacy Education's pre-APPE core domains of Identification and Assessment of Drug-related Problems and General Communication Abilities. Course mapping identified gaps in instruction, performance, and assessment of skills within aforementioned domains. Conclusions. A stepwise process that identified strengths and weaknesses of a course, was used to facilitate structured course redesign. Strengths of the process included input and corroboration from both preceptors and students. Limitations included feedback from a small number of pharmacy preceptors and increased workload on course coordinators.

  11. Technique of ICP monitored stepwise intracranial decompression effectively reduces postoperative complications of severe bifrontal contusion

    Directory of Open Access Journals (Sweden)

    Guan eSun

    2016-04-01

    Full Text Available Background Bifrontal contusion is a common clinical brain injury. In the early stage, it is often mild, but it progresses rapidly and frequently worsens suddenly. This condition can become life threatening and therefore requires surgery. Conventional decompression craniectomy is the commonly used treatment method. In this study, the effect of ICP monitored stepwise intracranial decompression surgery on the prognosis of patients with acute severe bifrontal contusion was investigated. Method A total of 136 patients with severe bifrontal contusion combined with deteriorated intracranial hypertension admitted from March 2001 to March 2014 in our hospital were selected and randomly divided into two groups, i.e., a conventional decompression group and an intracranial pressure (ICP monitored stepwise intracranial decompression group (68 patients each, to conduct a retrospective study. The incidence rates of acute intraoperative encephalocele, delayed hematomas, and postoperative cerebral infarctions and the Glasgow outcome scores (GOSs 6 months after the surgery were compared between the two groups.Results (1 The incidence rates of acute encephalocele and contralateral delayed epidural hematoma in the stepwise decompression surgery group were significantly lower than those in the conventional decompression group; the differences were statistically significant (P < 0.05; (2 6 months after the surgery, the incidence of vegetative state and mortality in the stepwise decompression group were significantly lower than those in the conventional decompression group (P < 0.05; the rate of favorable prognosis in the stepwise decompression group was also significantly higher than that in the conventional decompression group (P < 0.05.Conclusions The ICP monitored stepwise intracranial decompression technique reduced the perioperative complications of traumatic brain injury through the gradual release of intracranial pressure and was beneficial to the prognosis of

  12. Improvement of the Performance of Scheduled Stepwise Power Programme Changes within the European Power System

    DEFF Research Database (Denmark)

    Welfonder, E.; Weissbach, T.; Schulz, U.

    2008-01-01

    Since the deregulation of the electrical energy market, the technical realisation of power transactions based on energy market contracts often effects large stepwise power programme changes – especially at the change of the hour. Due to mainly economic reasons these stepwise power programme changes...... extended discussions with power plant and power system operators as well as with power plant dispatchers the described issues will be adopted into a VGB-recommendation which shall be published by VGB Powertech for Germany and Europe. Subsequently, it is intended to include the main elements of the VGB...

  13. Phenylketonuria mutation analysis in Northern Ireland: A rapid stepwise approach

    Energy Technology Data Exchange (ETDEWEB)

    Zschocke, J.; Graham, C.A.; Nevin, N.C. [Queen`s Univ., Belfast (Australia)] [and others

    1995-12-01

    We present a multistep approach for the rapid analysis of phenylketonuria (PKU) mutations. In the first step, three common mutations and a polymorphic short tandem repeat (STR) system are rapidly analyzed with a fluorescent multiplex assay. In the second step, minihaplotypes combining STR and VNTR data are used to determine rare mutations likely to be present in an investigated patient, which are then confirmed by restriction enzyme analysis. The remaining mutations are analyzed with denaturant gradient-gel electrophoresis and sequencing. The first two steps together identify both mutations in 90%-95% of PKU patients, and results can be obtained within 2 d. We have investigated 121 Northern Irish families with hyperphenylalaninemia, including virtually all patients born since 1972, and have found 34 different mutations on 241 of the 242 mutant alleles. Three mutations (R408W, 165T, and F39L) account for 57.5% of mutations, while 14 mutations occur with a frequency of 1%-6%. The present analysis system is efficient and inexpensive and is particularly well suited to routine mutation analysis in a diagnostic setting. 19 refs., 5 tabs.

  14. Stepwise Functional Evolution in a Fungal Sugar Transporter Family.

    Science.gov (United States)

    Gonçalves, Carla; Coelho, Marco A; Salema-Oom, Madalena; Gonçalves, Paula

    2016-02-01

    Sugar transport is of the utmost importance for most cells and is central to a wide range of applied fields. However, despite the straightforward in silico assignment of many novel transporters, including sugar porters, to existing families, their exact biological role and evolutionary trajectory often remain unclear, mainly because biochemical characterization of membrane proteins is inherently challenging, but also owing to their uncommonly turbulent evolutionary histories. In addition, many important shifts in membrane carrier function are apparently ancient, which further limits our ability to reconstruct evolutionary trajectories in a reliable manner. Here, we circumvented some of these obstacles by examining the relatively recent emergence of a unique family of fungal sugar facilitators, related to drug antiporters. The former transporters, named Ffz, were previously shown to be required for fructophilic metabolism in yeasts. We first exploited the wealth of fungal genomic data available to define a comprehensive but well-delimited family of Ffz-like transporters, showing that they are only present in Dikarya. Subsequently, a combination of phylogenetic analyses and in vivo functional characterization was used to retrace important changes in function, while highlighting the evolutionary events that are most likely to have determined extant distribution of the gene, such as horizontal gene transfers (HGTs). One such HGT event is proposed to have set the stage for the onset of fructophilic metabolism in yeasts, a trait that according to our results may be the metabolic hallmark of close to 100 yeast species that thrive in sugar rich environments. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Estimating leaf photosynthetic pigments information by stepwise multiple linear regression analysis and a leaf optical model

    Science.gov (United States)

    Liu, Pudong; Shi, Runhe; Wang, Hong; Bai, Kaixu; Gao, Wei

    2014-10-01

    Leaf pigments are key elements for plant photosynthesis and growth. Traditional manual sampling of these pigments is labor-intensive and costly, which also has the difficulty in capturing their temporal and spatial characteristics. The aim of this work is to estimate photosynthetic pigments at large scale by remote sensing. For this purpose, inverse model were proposed with the aid of stepwise multiple linear regression (SMLR) analysis. Furthermore, a leaf radiative transfer model (i.e. PROSPECT model) was employed to simulate the leaf reflectance where wavelength varies from 400 to 780 nm at 1 nm interval, and then these values were treated as the data from remote sensing observations. Meanwhile, simulated chlorophyll concentration (Cab), carotenoid concentration (Car) and their ratio (Cab/Car) were taken as target to build the regression model respectively. In this study, a total of 4000 samples were simulated via PROSPECT with different Cab, Car and leaf mesophyll structures as 70% of these samples were applied for training while the last 30% for model validation. Reflectance (r) and its mathematic transformations (1/r and log (1/r)) were all employed to build regression model respectively. Results showed fair agreements between pigments and simulated reflectance with all adjusted coefficients of determination (R2) larger than 0.8 as 6 wavebands were selected to build the SMLR model. The largest value of R2 for Cab, Car and Cab/Car are 0.8845, 0.876 and 0.8765, respectively. Meanwhile, mathematic transformations of reflectance showed little influence on regression accuracy. We concluded that it was feasible to estimate the chlorophyll and carotenoids and their ratio based on statistical model with leaf reflectance data.

  16. Stepwise Rock-Eval pyrolysis as a tool for typing heterogeneous organic matter in soils

    Energy Technology Data Exchange (ETDEWEB)

    Hetenyi, M.; Nyilas, T.; Toth, T.M. [Department of Mineralogy, Geochemistry and Petrology, University of Szeged, P.O. Box 651, H-6701 Szeged (Hungary)

    2005-08-15

    This paper presents an application of Rock-Eval pyrolysis for estimating the proportion of the components with different thermal stability in soil organic matter, the maturity of which corresponds to the early stage of diagenesis. For testing the validity of the modified Rock-Eval method, parallel series of pyrolysis were carried out on sedimentary rock samples. The temperature program was selected on the basis of the results obtained from stepwise Rock-Eval pyrolysis and from the mathematical deconvolution of pyrograms. The proportion of the original biomolecules in soil organic matter was calculated by the integration of pyrograms below 350{sup o}C and could be determined rapidly by one single pyrolysis using 350{sup o}C as initial cracking temperature. At 380{sup o}C, both the mathematical and the experimental methods provide reliable information about the proportion of the humic substances. Conversely, for rock samples, mathematical deconvolution of the pyrograms showed the heterogeneity of the sedimentary organic matter, the maturity of which corresponds to late diagenesis, without any estimation of the proportion of the different components. The rate of organic carbon accumulation in the studied soils and the decomposition rate of biopolymers were interpreted as a function of land-use and redox conditions. Differences in the precursor vegetation and in the environmental parameters resulted in markedly reduced carbon storage and higher degree of humification in the agricultural soil than in the adjacent forest soil. Redox conditions strongly affected both the amount and the elemental composition of the stored organic matter. The decomposition rate of biopolymers appeared to be controlled mainly by the contribution of resistant lignin components to the source biomass and, to a lesser extent, by redox conditions.

  17. Stepwise multiple regression method of greenhouse gas emission modeling in the energy sector in Poland.

    Science.gov (United States)

    Kolasa-Wiecek, Alicja

    2015-04-01

    The energy sector in Poland is the source of 81% of greenhouse gas (GHG) emissions. Poland, among other European Union countries, occupies a leading position with regard to coal consumption. Polish energy sector actively participates in efforts to reduce GHG emissions to the atmosphere, through a gradual decrease of the share of coal in the fuel mix and development of renewable energy sources. All evidence which completes the knowledge about issues related to GHG emissions is a valuable source of information. The article presents the results of modeling of GHG emissions which are generated by the energy sector in Poland. For a better understanding of the quantitative relationship between total consumption of primary energy and greenhouse gas emission, multiple stepwise regression model was applied. The modeling results of CO2 emissions demonstrate a high relationship (0.97) with the hard coal consumption variable. Adjustment coefficient of the model to actual data is high and equal to 95%. The backward step regression model, in the case of CH4 emission, indicated the presence of hard coal (0.66), peat and fuel wood (0.34), solid waste fuels, as well as other sources (-0.64) as the most important variables. The adjusted coefficient is suitable and equals R2=0.90. For N2O emission modeling the obtained coefficient of determination is low and equal to 43%. A significant variable influencing the amount of N2O emission is the peat and wood fuel consumption. Copyright © 2015. Published by Elsevier B.V.

  18. Inferring transcriptional compensation interactions in yeast via stepwise structure equation modeling

    Directory of Open Access Journals (Sweden)

    Wang Woei-Fuh

    2008-03-01

    Full Text Available Abstract Background With the abundant information produced by microarray technology, various approaches have been proposed to infer transcriptional regulatory networks. However, few approaches have studied subtle and indirect interaction such as genetic compensation, the existence of which is widely recognized although its mechanism has yet to be clarified. Furthermore, when inferring gene networks most models include only observed variables whereas latent factors, such as proteins and mRNA degradation that are not measured by microarrays, do participate in networks in reality. Results Motivated by inferring transcriptional compensation (TC interactions in yeast, a stepwise structural equation modeling algorithm (SSEM is developed. In addition to observed variables, SSEM also incorporates hidden variables to capture interactions (or regulations from latent factors. Simulated gene networks are used to determine with which of six possible model selection criteria (MSC SSEM works best. SSEM with Bayesian information criterion (BIC results in the highest true positive rates, the largest percentage of correctly predicted interactions from all existing interactions, and the highest true negative (non-existing interactions rates. Next, we apply SSEM using real microarray data to infer TC interactions among (1 small groups of genes that are synthetic sick or lethal (SSL to SGS1, and (2 a group of SSL pairs of 51 yeast genes involved in DNA synthesis and repair that are of interest. For (1, SSEM with BIC is shown to outperform three Bayesian network algorithms and a multivariate autoregressive model, checked against the results of qRT-PCR experiments. The predictions for (2 are shown to coincide with several known pathways of Sgs1 and its partners that are involved in DNA replication, recombination and repair. In addition, experimentally testable interactions of Rad27 are predicted. Conclusion SSEM is a useful tool for inferring genetic networks, and the

  19. Multi-type Step-wise group screening designs with unequal A-priori ...

    African Journals Online (AJOL)

    ... design with unequal group sizes and obtain values of the group sizes that minimize the expected number of runs.. Keywords: Group Screening, Group factors, multi-type step-wise group screening, expected number of runs, Optimum group screening designs > East African Journal of Statistics Vol. 1 (1) 2005: pp. 49-67 ...

  20. Stepwise extraction of Lepidium sativum seed gum: Physicochemical characterization and functional properties

    DEFF Research Database (Denmark)

    Razmkhah, Somayeh; Razavi, Seyed Mohammad Ali; Mohammadifar, Mohammad Amin

    2016-01-01

    Cress seed gum (CSG) was fractionated using stepwise extraction with water, yielding three fractions (F1, F2, F3) whose average molecular weights ranged from 863 to 1080 kDa. The chemical composition (monosaccharide, ash, moisture, CHN and uronic acid contents) and molecular weight of the fractio...

  1. Stepwise withdrawal of inhaled corticosteroids in COPD patients receiving dual bronchodilation

    DEFF Research Database (Denmark)

    Magnussen, Helgo; Watz, Henrik; Kirsten, Anne

    2014-01-01

    -controlled fashion, one group of patients continues to receive tiotropium, salmeterol and fluticasone, while the second group initiates stepwise withdrawal of fluticasone. The primary end point is time to first moderate or severe exacerbation following randomized treatment over 52 weeks. Lung function, symptoms...

  2. Efficient and Mild Microwave-Assisted Stepwise Functionalization of Naphthalenediimide with α-Amino Acids

    NARCIS (Netherlands)

    Pengo, Paolo; Pantoş, G. Dan; Otto, Sijbren; Sanders, Jeremy K.M.

    2006-01-01

    Microwave dielectric heating proved to be an efficient method for the one-pot and stepwise syntheses of symmetrical and unsymmetrical naphthalenediimide derivatives of α-amino acids. Acid-labile side chain protecting groups are stable under the reaction conditions; protection of the α-carboxylic

  3. Stepwise or concerted? DFT study on the mechanism of ionic Diels-Alder reaction of chromanes

    Directory of Open Access Journals (Sweden)

    Haghdadi Mina

    2016-01-01

    Full Text Available The stepwise and concerted Ionic Diels-Alder reaction between phenyl (pyridin-2-ylmethylene oxonium and styrene derivatives are explored using theoretical method. The results support using computational method via persistent intermediates. The DFT method was essential to reproduce a reasonable potential energy surface for these challenging systems.

  4. Stepwise radical endoscopic resection for Barrett's esophagus with early neoplasia: report on a Brussels' cohort

    NARCIS (Netherlands)

    Pouw, R. E.; Peters, F. P.; Sempoux, C.; Piessevaux, H.; Deprez, P. H.

    2008-01-01

    Background and study aims: The aim of this retrospective study was to assess safety and efficacy of stepwise radical endoscopic resection (SRER) in patients with Barrett's esophagus with high-grade intraepithelial neoplasia (HGIN) or early cancer. Patients and methods: Patients undergoing SRER

  5. EFEKTIVITAS METODE NEW STEPWISE DALAM PEMILIHAN VARIABEL PADA MODEL REGRESI GANDA

    Directory of Open Access Journals (Sweden)

    Thamrin Tayeb

    2017-12-01

    Full Text Available New stepwise method is a method of selecting predictor variables in a linear reg- ression model. This method is an extension of the principal component regressi- on, and consists of the selection of the original predictor variables iteratively at the same time, a group of main subset component is selected repeatedly. This me- thod has also the basic properties of the stepwise method. Thus we will get the best combination of stepwise selection and principal component selection me- thods. Model that is obtained by using this method characterizes a low-valued PRESS. The application of this method is not only for linear model, but also can  be expanded to generalized linear models. The comparison of both methods are based on the R2 criteria in the variable selection, obtained R2 value results which are almost the same as those models in the case of solid waste of data, so having payed fully attention to the number of predictor variables entered into the mo- dels, it can be said that the new stepwise method tends to be better than the prin- cipal component regression.

  6. modelling of directed evolution: Implications for experimental design and stepwise evolution

    OpenAIRE

    Wedge , David C.; Rowe , William; Kell , Douglas B.; Knowles , Joshua

    2009-01-01

    In silico modelling of directed evolution: Implications for experimental design and stepwise evolution correspondence: Corresponding author. Tel.: +441613065145. (Wedge, David C.) (Wedge, David C.) Manchester Interdisciplinary Biocentre, University of Manchester - 131 Princess Street--> , Manchester--> , M1 7ND--> - UNITED KINGDOM (Wedge, David C.) UNITED KINGDOM (Wedge, David C.) Man...

  7. An antarctic stratigraphic record of stepwise ice growth through the eocene-oligocene transition

    NARCIS (Netherlands)

    Passchier, Sandra; Ciarletta, Daniel J.; Miriagos, Triantafilo E.; Bijl, Peter K.; Bohaty, Steven M.

    2017-01-01

    Earth's current icehouse phase began ~34 m.y. ago with the onset of major Antarctic glaciation at the Eocene-Oligocene transition. Changes in ocean circulation and a decline in atmospheric greenhouse gas levels were associated with stepwise cooling and ice growth at southern high latitudes. The

  8. A stepwise approach to stroke surveillance in Brazil: the EMMA (Estudo de Mortalidade e Morbidade do Acidente Vascular Cerebral) study.

    Science.gov (United States)

    Goulart, Alessandra C; Bustos, Iara R; Abe, Ivana M; Pereira, Alexandre C; Fedeli, Ligia M; Benseñor, Isabela M; Lotufo, Paulo A

    2010-08-01

    Stroke mortality rates in Brazil are the highest in the Americas. Deaths from cerebrovascular disease surpass coronary heart disease. To verify stroke mortality rates and morbidity in an area of São Paulo, Brazil, using the World Health Organization Stepwise Approach to Stroke Surveillance. We used the World Health Organization Stepwise Approach to Stroke Surveillance structure of stroke surveillance. The hospital-based data comprised fatal and nonfatal stroke (Step 1). We gathered stroke-related mortality data in the community using World Health Organization questionnaires (Step 2). The questionnaire determining stroke prevalence was activated door to door in a family-health-programme neighbourhood (Step 3). A total of 682 patients 18 years and above, including 472 incident cases, presented with cerebrovascular disease and were enrolled in Step 1 during April-May 2009. Cerebral infarction (84.3%) and first-ever stroke (85.2%) were the most frequent. In Step 2, 256 deaths from stroke were identified during 2006-2007. Forty-four per cent of deaths were classified as unspecified stroke, 1/3 as ischaemic stroke, and 1/4 due to haemorrhagic subtype. In Step 3, 577 subjects over 35 years old were evaluated at home, and 244 cases of stroke survival were diagnosed via a questionnaire, validated by a board-certified neurologist. The population demographic characteristics were similar in the three steps, except in terms of age and gender. By including data from all settings, World Health Organization stroke surveillance can provide data to help plan future resources that meet the needs of the public-health system.

  9. A stepwise regression tree for nonlinear approximation: applications to estimating subpixel land cover

    Science.gov (United States)

    Huang, C.; Townshend, J.R.G.

    2003-01-01

    A stepwise regression tree (SRT) algorithm was developed for approximating complex nonlinear relationships. Based on the regression tree of Breiman et al . (BRT) and a stepwise linear regression (SLR) method, this algorithm represents an improvement over SLR in that it can approximate nonlinear relationships and over BRT in that it gives more realistic predictions. The applicability of this method to estimating subpixel forest was demonstrated using three test data sets, on all of which it gave more accurate predictions than SLR and BRT. SRT also generated more compact trees and performed better than or at least as well as BRT at all 10 equal forest proportion interval ranging from 0 to 100%. This method is appealing to estimating subpixel land cover over large areas.

  10. Application of stepwise multiple regression techniques to inversion of Nimbus 'IRIS' observations.

    Science.gov (United States)

    Ohring, G.

    1972-01-01

    Exploratory studies with Nimbus-3 infrared interferometer-spectrometer (IRIS) data indicate that, in addition to temperature, such meteorological parameters as geopotential heights of pressure surfaces, tropopause pressure, and tropopause temperature can be inferred from the observed spectra with the use of simple regression equations. The technique of screening the IRIS spectral data by means of stepwise regression to obtain the best radiation predictors of meteorological parameters is validated. The simplicity of application of the technique and the simplicity of the derived linear regression equations - which contain only a few terms - suggest usefulness for this approach. Based upon the results obtained, suggestions are made for further development and exploitation of the stepwise regression analysis technique.

  11. An Inter-Networking Mechanism with Stepwise Synchronization for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Masayuki Murata

    2011-08-01

    Full Text Available To realize the ambient information society, multiple wireless networks deployed in the region and devices carried by users are required to cooperate with each other. Since duty cycles and operational frequencies are different among networks, we need a mechanism to allow networks to efficiently exchange messages. For this purpose, we propose a novel inter-networking mechanism where two networks are synchronized with each other in a moderate manner, which we call stepwise synchronization. With our proposal, to bridge the gap between intrinsic operational frequencies, nodes near the border of networks adjust their operational frequencies in a stepwise fashion based on the pulse-coupled oscillator model as a fundamental theory of synchronization. Through simulation experiments, we show that the communication delay and the energy consumption of border nodes are reduced, which enables wireless sensor networks to communicate longer with each other.

  12. Impact of Antibiotic Shortage on H. Pylori Treatment: A Step-Wise Approach for Pharmacist Management

    Directory of Open Access Journals (Sweden)

    Michelle M. Lamb

    2013-01-01

    Full Text Available The current drug shortage crisis involving multiple oral antibiotics has significantly impacted preferred therapeutic options for treatment of H.pylori infection. Pharmacists may help alleviate the impact of this shortage through a proposed step-wise approach which includes proper inventory management, verification of indication, evaluation of regimen, therapeutic monitoring, and communication with patients and providers regarding alternative therapy or symptomatic relief.   Type: Original Research

  13. Porous media fracturing dynamics: stepwise crack advancement and fluid pressure oscillations

    Science.gov (United States)

    Cao, Toan D.; Hussain, Fazle; Schrefler, Bernhard A.

    2018-02-01

    We present new results explaining why fracturing in saturated porous media is not smooth and continuous but is a distinct stepwise process concomitant with fluid pressure oscillations. All exact solutions and almost all numerical models yield smooth fracture advancement and fluid pressure evolution, while recent experimental results, mainly from the oil industry, observation from geophysics and a very few numerical results for the quasi-static case indeed reveal the stepwise phenomenon. We summarize first these new experiments and these few numerical solutions for the quasi-static case. Both mechanical loading and pressure driven fractures are considered because their behaviours differ in the direction of the pressure jumps. Then we explore stepwise crack tip advancement and pressure fluctuations in dynamic fracturing with a hydro-mechanical model of porous media based on the Hybrid Mixture Theory. Full dynamic analyses of examples dealing with both hydraulic fracturing and mechanical loading are presented. The stepwise fracture advancement is confirmed in the dynamic setting as well as in the pressure fluctuations, but there are substantial differences in the frequency contents of the pressure waves in the two loading cases. Comparison between the quasi-static and fully dynamic solutions reveals that the dynamic response gives much more information such as the type of pressure oscillations and related frequencies and should be applied whenever there is a doubt about inertia forces playing a role - the case in most fracturing events. In the absence of direct relevant dynamic tests on saturated media some experimental results on dynamic fracture in dry materials, a fast hydraulic fracturing test and observations from geophysics confirm qualitatively the obtained results such as the type of pressure oscillations and the substantial difference in the behaviour under the two loading cases.

  14. Stepwise cyanation of naphthalene diimide for n-channel field-effect transistors

    KAUST Repository

    Chang, Jingjing

    2012-06-15

    Stepwise cyanation of tetrabromonaphthalenediimide (NDI) 1 gave a series of cyanated NDIs 2-5 with the monocyanated NDI 2 and dicyanated NDI 3 isolated. The tri- and tetracyano- NDIs 4 and 5 show intrinsic instability toward moisture because of their extremely low-lying LUMO energy levels. The partially cyanated intermediates can be utilized as air-stable n-type semiconductors with OFET electron mobility up to 0.05 cm 2 V -1 s -1. © 2012 American Chemical Society.

  15. Laboratory quality stepwise implementation tool: National reference TB laboratory of Iran

    OpenAIRE

    Ali Naghi Kebriaee; Donya Malekshahian; Mojtaba Ahmadi; Parissa Farnia

    2015-01-01

    Background and objective: During recent years, the World Health Organization (WHO) proposed new software for improving the tuberculosis (TB) laboratory services. The protocol is known as “quality stepwise implementation tool” and is based on enforcement of quality assurance services through accreditation by the International Organization for Standardization (ISO) 15189. As a national reference TB laboratory (NRL) of Iran, the benefit and challenges of implementing this standard were analyzed....

  16. Stepwise synthesis and characterization of germa[4], [5], [8], and [10]pericyclynes.

    Science.gov (United States)

    Tanimoto, Hiroki; Nagao, Tomohiko; Fujiwara, Taro; Nishiyama, Yasuhiro; Morimoto, Tsumoru; Suzuka, Toshimasa; Tsutsumi, Ken; Kakiuchi, Kiyomi

    2015-07-14

    The stepwise syntheses of germa[N]pericyclynes, including [5]pericyclynes, and their characterization are described. The yields of germa[4] and [8]pericyclynes were improved significantly compared to those obtained in previous studies. The routes reported herein afforded the novel germa[5] and [10]pericyclynes, which were characterized by X-ray crystallography, UV-Vis spectroscopy, and fluorescence emission spectroscopy. A unique fluorescence emission was observed for the large germa[10]pericyclyne ring.

  17. Impact of Antibiotic Shortage on H. Pylori Treatment: A Step-Wise Approach for Pharmacist Management

    Directory of Open Access Journals (Sweden)

    Ann Lloyd, Pharm.D., BCPS

    2013-01-01

    Full Text Available The current drug shortage crisis involving multiple oral antibiotics has significantly impacted preferred therapeutic options for treatment of H.pylori infection. Pharmacists may help alleviate the impact of this shortage through a proposed step-wise approach which includes proper inventory management, verification of indication, evaluation of regimen, therapeutic monitoring, and communication with patients and providers regarding alternative therapy or symptomatic relief.

  18. Fourth-order Perturbed Eigenvalue Equation for Stepwise Damage Detection of Aeroplane Wing

    Directory of Open Access Journals (Sweden)

    Wong Chun Nam

    2016-01-01

    Full Text Available Perturbed eigenvalue equations up to fourth-order are established to detect structural damage in aeroplane wing. Complete set of perturbation terms including orthogonal and non-orthogonal coefficients are computed using perturbed eigenvalue and orthonormal equations. Then the perturbed eigenparameters are optimized using BFGS approach. Finite element model with small to large stepwise damage is used to represent actual aeroplane wing. In small damaged level, termination number is the same for both approaches, while rms errors and termination d-norms are very close. For medium damaged level, termination number is larger for third-order perturbation with lower d-norm and smaller rms error. In large damaged level, termination number is much larger for third-order perturbation with same d-norm and larger rms error. These trends are more significant as the damaged level increases. As the stepwise damage effect increases with damage level, the increase in stepwise effect leads to the increase in model order. Hence, fourth-order perturbation is more accurate to estimate the model solution.

  19. In vitro production of buffalo embryos from stepwise vitrified immature oocytes.

    Science.gov (United States)

    Abd-Allah, Saber Mohammed

    2009-01-01

    This study was conducted to produce buffalo embryos in vitro from stepwise vitrified immature oocytes. Cumulus oocyte complexes (COCs) were obtained from the ovaries of slaughtered buffalo and were collected from the local abattoir. Selected COCs were exposed to a vitrification solution consisting of 40% ethylene glycol (EG) plus 0.3 M trehalose and 20% polyvinyl pyrrolidone (PVP) for 1 min and loaded in 0.25 ml plastic mini-straws containing 100 microl of 10% sucrose. The loaded cryostraws were cryopreserved by stepwise vitrification and were stored in liquid nitrogen for 4 to 6 months. Data analysis revealed a high percentage of post-thawing morphologically normal immature oocytes (80.7%) with a low percentage of damaged oocytes. There were no significant differences in the maturation (82.1%), cleavage (47.6%) and buffalo embryo development (15.4%) produced by the stepwise vitrified immature oocytes in comparison to the three observations in fresh oocytes (88.3%, 50.4% and 19.4%, respectively, p<0.05).

  20. A stepwise composite echocardiographic score predicts severe pulmonary hypertension in patients with interstitial lung disease.

    Science.gov (United States)

    Bax, Simon; Bredy, Charlene; Kempny, Aleksander; Dimopoulos, Konstantinos; Devaraj, Anand; Walsh, Simon; Jacob, Joseph; Nair, Arjun; Kokosi, Maria; Keir, Gregory; Kouranos, Vasileios; George, Peter M; McCabe, Colm; Wilde, Michael; Wells, Athol; Li, Wei; Wort, Stephen John; Price, Laura C

    2018-04-01

    European Respiratory Society (ERS) guidelines recommend the assessment of patients with interstitial lung disease (ILD) and severe pulmonary hypertension (PH), as defined by a mean pulmonary artery pressure (mPAP) ≥35 mmHg at right heart catheterisation (RHC). We developed and validated a stepwise echocardiographic score to detect severe PH using the tricuspid regurgitant velocity and right atrial pressure (right ventricular systolic pressure (RVSP)) and additional echocardiographic signs. Consecutive ILD patients with suspected PH underwent RHC between 2005 and 2015. Receiver operating curve analysis tested the ability of components of the score to predict mPAP ≥35 mmHg, and a score devised using a stepwise approach. The score was tested in a contemporaneous validation cohort. The score used "additional PH signs" where RVSP was unavailable, using a bootstrapping technique. Within the derivation cohort (n=210), a score ≥7 predicted severe PH with 89% sensitivity, 71% specificity, positive predictive value 68% and negative predictive value 90%, with similar performance in the validation cohort (n=61) (area under the curve (AUC) 84.8% versus 83.1%, p=0.8). Although RVSP could be estimated in 92% of studies, reducing this to 60% maintained a fair accuracy (AUC 74.4%). This simple stepwise echocardiographic PH score can predict severe PH in patients with ILD.

  1. In vitro production of buffalo embryos from stepwise vitrified immature oocytes

    Directory of Open Access Journals (Sweden)

    Saber Mohammed Abd-Allah

    2009-09-01

    Full Text Available This study was conducted to produce buffalo embryos in vitro from stepwise vitrified immature oocytes. Cumulus oocyte complexes (COCs were obtained from the ovaries of slaughtered buffalo and were collected from the local abattoir. Selected COCs were exposed to a vitrification solution consisting of 40% ethylene glycol (EG plus 0.3 M trehalose and 20% polyvinyl pyrrolidone (PVP for 1 min and loaded in 0.25 ml plastic mini-straws containing 100 µl of 10% sucrose. The loaded cryostraws were cryopreserved by stepwise vitrification and were stored in liquid nitrogen for 4 to 6 months. Data analysis revealed a high percentage of post-thawing morphologically normal immature oocytes (80.7% with a low percentage of damaged oocytes. There were no significant differences in the maturation (82.1%, cleavage (47.6% and buffalo embryo development (15.4% produced by the stepwise vitrified immature oocytes in comparison to the three observations in fresh oocytes (88.3%, 50.4% and 19.4%, respectively, p<0.05.

  2. A Data Forward Stepwise Fitting Algorithm Based on Orthogonal Function System

    Directory of Open Access Journals (Sweden)

    Li Han-Ju

    2017-01-01

    Full Text Available Data fitting is the main method of functional data analysis, and it is widely used in the fields of economy, social science, engineering technology and so on. Least square method is the main method of data fitting, but the least square method is not convergent, no memory property, big fitting error and it is easy to over fitting. Based on the orthogonal trigonometric function system, this paper presents a data forward stepwise fitting algorithm. This algorithm takes forward stepwise fitting strategy, each time using the nearest base function to fit the residual error generated by the previous base function fitting, which makes the residual mean square error minimum. In this paper, we theoretically prove the convergence, the memory property and the fitting error diminishing character for the algorithm. Experimental results show that the proposed algorithm is effective, and the fitting performance is better than that of the least square method and the forward stepwise fitting algorithm based on the non-orthogonal function system.

  3. Stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Osipova, Z.G.; Sokolovskii, V.D.

    1979-03-01

    The stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts GaSb/sub 19/O/sub x/, GaSb/sub 3/Ni/sub 1.5/0/sub x/, and GaSb/sub 2.5/Ni/sub 1.5/PW/sub 0//sub 0.25/O/sub x/ was studied at 450/sup 0/ and 550/sup 0/C by introducing alternating pulses of 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/helium (to reduce the steady-state catalytic surface) and 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/1.86Vertical Bar3< oxygen/helium mixtures into a fluidized-bed catalytic reactor. Over all the catalysts studied, the rates of acrylonitrile formation during the two types of pulses were very similar, but carbon dioxide was formed much faster during the reducing pulses, particularly at 450/sup 0/C. These findings suggested that acrylonitrile is formed by a stepwise redox mechanism involving consecutive interaction of propane and ammonia with the surface oxygen of the catalysts and oxidation of the reduced catalyst surface by gas-phase oxygen. The formation of carbon dioxide proceeds by both stepwise and associative mechanisms, the latter being more important at higher temperatures. The results are similar to published results for ammoxidation of propylene and olefins.

  4. A novel peak-hopping stepwise feature selection method with application to Raman spectroscopy

    International Nuclear Information System (INIS)

    McShane, M.J.; Cameron, B.D.; Cote, G.L.; Motamedi, M.; Spiegelman, C.H.

    1999-01-01

    A new stepwise approach to variable selection for spectroscopy that includes chemical information and attempts to test several spectral regions producing high ranking coefficients has been developed to improve on currently available methods. Existing selection techniques can, in general, be placed into two groups: the first, time-consuming optimization approaches that ignore available information about sample chemistry and require considerable expertise to arrive at appropriate solutions (e.g. genetic algorithms), and the second, stepwise procedures that tend to select many variables in the same area containing redundant information. The algorithm described here is a fast stepwise procedure that uses multiple ranking chains to identify several spectral regions correlated with known sample properties. The multiple-chain approach allows the generation of a final ranking vector that moves quickly away from the initial selection point, testing several areas exhibiting correlation between spectra and composition early in the stepping procedure. Quantitative evidence of the success of this approach as applied to Raman spectroscopy is given in terms of processing speed, number of selected variables, and prediction error in comparison with other selection methods. In this respect, the procedure described here may be considered as a significant evolutionary step in variable selection algorithms. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. A stepwise protocol for the treatment of refractory gastroesophageal reflux-induced chronic cough

    Science.gov (United States)

    Xu, Xianghuai; Lv, Hanjing; Yu, Li; Chen, Qiang; Liang, Siwei

    2016-01-01

    Background Refractory gastroesophageal reflux-induced chronic cough (GERC) is difficult to manage. The purpose of the study is to evaluate the efficacy of a novel stepwise protocol for treating this condition. Methods A total of 103 consecutive patients with suspected refractory reflux-induced chronic cough failing to a standard anti-reflux therapy were treated with a stepwise therapy. Treatment commences with high-dose omeprazole and, if necessary, is escalated to subsequent sequential treatment with ranitidine and finally baclofen. The primary end-point was overall cough resolution, and the secondary end-point was cough resolution after each treatment step. Results High-dose omeprazole eliminated or improved cough in 28.1% of patients (n=29). Further stepwise of treatment with the addition of ranitide yielded a favorable response in an additional 12.6% (n=13) of patients, and subsequent escalation to baclofen provoked response in another 36.9% (n=38) of patients. Overall, this stepwise protocol was successful in 77.6% (n=80) of patients. The diurnal cough symptom score fell from 3 [1] to 1 [0] (Z=6.316, P=0.000), and the nocturnal cough symptom score decreased from 1 [1] to 0 [1] (Z=–4.511, P=0.000), with a corresponding reduction in the Gastroesophageal Reflux Diagnostic Questionnaire score from 8.6±1.7 to 6.8±0.7 (t=3.612, P=0.000). Conversely, the cough threshold C2 to capsaicin was increased from 0.49 (0.49) µmol/L to 1.95 (2.92) µmol/L (Z=–5.892, P=0.000), and the cough threshold C5 was increased from 1.95 (2.92) µmol/L to 7.8 (5.85) µmol/L (Z=–5.171, P=0.000). Conclusions Sequential stepwise anti-reflux therapy is a useful therapeutic strategy for refractory reflux-induced chronic cough. PMID:26904227

  6. Step-wise and punctuated genome evolution drive phenotype changes of tumor cells

    International Nuclear Information System (INIS)

    Stepanenko, Aleksei; Andreieva, Svitlana; Korets, Kateryna; Mykytenko, Dmytro; Huleyuk, Nataliya; Vassetzky, Yegor; Kavsan, Vadym

    2015-01-01

    Highlights: • There are the step-wise continuous and punctuated phases of cancer genome evolution. • The system stresses during the different phases may lead to very different responses. • Stable transfection of an empty vector can result in genome and phenotype changes. • Functions of a (trans)gene can be opposite/versatile in cells with different genomes. • Contextually, temozolomide can both promote and suppress tumor cell aggressiveness. - Abstract: The pattern of genome evolution can be divided into two phases: the step-wise continuous phase (step-wise clonal evolution, stable dominant clonal chromosome aberrations (CCAs), and low frequency of non-CCAs, NCCAs) and punctuated phase (marked by elevated NCCAs and transitional CCAs). Depending on the phase, system stresses (the diverse CIN promoting factors) may lead to the very different phenotype responses. To address the contribution of chromosome instability (CIN) to phenotype changes of tumor cells, we characterized CCAs/NCCAs of HeLa and HEK293 cells, and their derivatives after genotoxic stresses (a stable plasmid transfection, ectopic expression of cancer-associated CHI3L1 gene or treatment with temozolomide) by conventional cytogenetics, copy number alterations (CNAs) by array comparative genome hybridization, and phenotype changes by cell viability and soft agar assays. Transfection of either the empty vector pcDNA3.1 or pcDNA3.1-CHI3L1 into 293 cells initiated the punctuated genome changes. In contrast, HeLa-CHI3L1 cells demonstrated the step-wise genome changes. Increased CIN correlated with lower viability of 293-pcDNA3.1 cells but higher colony formation efficiency (CFE). Artificial CHI3L1 production in 293-CHI3L1 cells increased viability and further contributed to CFE. The opposite growth characteristics of 293-CHI3L1 and HeLa-CHI3L1 cells were revealed. The effect and function of a (trans)gene can be opposite and versatile in cells with different genetic network, which is defined by

  7. Step-wise and punctuated genome evolution drive phenotype changes of tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Stepanenko, Aleksei, E-mail: a.a.stepanenko@gmail.com [Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680 (Ukraine); Andreieva, Svitlana; Korets, Kateryna; Mykytenko, Dmytro [Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680 (Ukraine); Huleyuk, Nataliya [Institute of Hereditary Pathology, National Academy of Medical Sciences of Ukraine, Lviv 79008 (Ukraine); Vassetzky, Yegor [CNRS UMR8126, Université Paris-Sud 11, Institut de Cancérologie Gustave Roussy, Villejuif 94805 (France); Kavsan, Vadym [Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv 03680 (Ukraine)

    2015-01-15

    Highlights: • There are the step-wise continuous and punctuated phases of cancer genome evolution. • The system stresses during the different phases may lead to very different responses. • Stable transfection of an empty vector can result in genome and phenotype changes. • Functions of a (trans)gene can be opposite/versatile in cells with different genomes. • Contextually, temozolomide can both promote and suppress tumor cell aggressiveness. - Abstract: The pattern of genome evolution can be divided into two phases: the step-wise continuous phase (step-wise clonal evolution, stable dominant clonal chromosome aberrations (CCAs), and low frequency of non-CCAs, NCCAs) and punctuated phase (marked by elevated NCCAs and transitional CCAs). Depending on the phase, system stresses (the diverse CIN promoting factors) may lead to the very different phenotype responses. To address the contribution of chromosome instability (CIN) to phenotype changes of tumor cells, we characterized CCAs/NCCAs of HeLa and HEK293 cells, and their derivatives after genotoxic stresses (a stable plasmid transfection, ectopic expression of cancer-associated CHI3L1 gene or treatment with temozolomide) by conventional cytogenetics, copy number alterations (CNAs) by array comparative genome hybridization, and phenotype changes by cell viability and soft agar assays. Transfection of either the empty vector pcDNA3.1 or pcDNA3.1-CHI3L1 into 293 cells initiated the punctuated genome changes. In contrast, HeLa-CHI3L1 cells demonstrated the step-wise genome changes. Increased CIN correlated with lower viability of 293-pcDNA3.1 cells but higher colony formation efficiency (CFE). Artificial CHI3L1 production in 293-CHI3L1 cells increased viability and further contributed to CFE. The opposite growth characteristics of 293-CHI3L1 and HeLa-CHI3L1 cells were revealed. The effect and function of a (trans)gene can be opposite and versatile in cells with different genetic network, which is defined by

  8. Is there a step-wise migration in Nigeria? A case study of the migrational histories of migrants in Lagos.

    Science.gov (United States)

    Afolayan, A A

    1985-09-01

    "The paper sets out to test whether or not the movement pattern of people in Nigeria is step-wise. It examines the spatial order in the country and the movement pattern of people. It then analyzes the survey data and tests for the validity of step-wise migration in the country. The findings show that step-wise migration cannot adequately describe all the patterns observed." The presence of large-scale circulatory migration between rural and urban areas is noted. Ways to decrease the pressure on Lagos by developing intermediate urban areas are considered. excerpt

  9. Multiple linear stepwise regression of liver lipid levels: proton MR spectroscopy study in vivo at 3.0 T

    International Nuclear Information System (INIS)

    Xu Li; Liang Changhong; Xiao Yuanqiu; Zhang Zhonglin

    2010-01-01

    Objective: To analyze the correlations between liver lipid level determined by liver 3.0 T 1 H-MRS in vivo and influencing factors using multiple linear stepwise regression. Methods: The prospective study of liver 1 H-MRS was performed with 3.0 T system and eight-channel torso phased-array coils using PRESS sequence. Forty-four volunteers were enrolled in this study. Liver spectra were collected with a TR of 1500 ms, TE of 30 ms, volume of interest of 2 cm×2 cm×2 cm, NSA of 64 times. The acquired raw proton MRS data were processed by using a software program SAGE. For each MRS measurement, using water as the internal reference, the amplitude of the lipid signal was normalized to the sum of the signal from lipid and water to obtain percentage lipid within the liver. The statistical description of height, weight, age and BMI, Line width and water suppression were recorded, and Pearson analysis was applied to test their relationships. Multiple linear stepwise regression was used to set the statistical model for the prediction of Liver lipid content. Results: Age (39.1±12.6) years, body weight (64.4±10.4) kg, BMI (23.3±3.1) kg/m 2 , linewidth (18.9±4.4) and the water suppression (90.7±6.5)% had significant correlation with liver lipid content (0.00 to 0.96%, median 0.02%), r were 0.11, 0.44, 0.40, 0.52, -0.73 respectively (P<0.05). But only age, BMI, line width, and the water suppression entered into the multiple linear regression equation. Liver lipid content prediction equation was as follows: Y= 1.395 - (0.021×water suppression) + (0.022×BMI) + (0.014×line width) - (0.004×age), and the coefficient of determination was 0. 613, corrected coefficient of determination was 0.59. Conclusion: The regression model fitted well, since the variables of age, BMI, width, and water suppression can explain about 60% of liver lipid content changes. (authors)

  10. Monitoring during the stepwise implementation of the Swedish deep repository for spent fuel

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Almen, Karl-Erik

    2004-03-01

    terminate, quality control and reporting results from monitoring, decision on trigger levels for actions, decisions on what actions should be pursued in case trigger levels are exceeded). The site investigations in progress in Sweden essentially capture these elements in the investigation programme, but due to reasons of transparency it is however helpful that the present monitoring programme is further elaborated to clarify duration, frequency and criteria for terminating monitoring points. The current situation is reasonable due to the early stage of investigations and it is foreseen that the monitoring programme successively will be developed to meet the needs of the subsequent construction phase. There are of course still many open questions to address with respect to monitoring, not the least concerning monitoring of the open repository to collect data to verify barrier performance before closing the repository. Repository performance and safety cannot be directly monitored, but it would be of great significance that key indicators are determined to constitute a basis for tracking the performance of the repository during the repository implementation. Repository closure is a stepwise process from consecutively closing a deposition tunnel to closing one or several deposition areas before the whole repository is closed. It is possible that rationales for monitoring of the post-closure phase, such as verification of safeguard requirements, may develop. The extent of the post-closure monitoring programme will essentially be given by the decisions made at closure and it is appropriate that any decisions on post-closure monitoring are taken by the generation that is the decision-maker at the time of closure. While the responsibility for the repository is transferred to the State after closure it is then also needed to clarify the responsibility for execution of the post-closure monitoring

  11. Biodiesel production from various oils under supercritical fluid conditions by Candida antartica lipase B using a stepwise reaction method.

    Science.gov (United States)

    Lee, Jong Ho; Kwon, Cheong Hoon; Kang, Jeong Won; Park, Chulhwan; Tae, Bumseok; Kim, Seung Wook

    2009-05-01

    In this study, we evaluate the effects of various reaction factors, including pressure, temperature, agitation speed, enzyme concentration, and water content to increase biodiesel production. In addition, biodiesel was produced from various oils to establish the optimal enzymatic process of biodiesel production. Optimal conditions were determined to be as follows: pressure 130 bar, temperature 45 degrees C, agitation speed 200 rpm, enzyme concentration 20%, and water contents 10%. Among the various oils used for production, olive oil showed the highest yield (65.18%) upon transesterification. However, when biodiesel was produced using a batch system, biodiesel conversion yield was not increased over 65%; therefore, a stepwise reaction was conducted to increase biodiesel production. When a reaction medium with an initial concentration of methanol of 60 mmol was used and adjusted to maintain this concentration of methanol every 1.5 h during biodiesel production, the conversion yield of biodiesel was 98.92% at 6 h. Finally, reusability was evaluated using immobilized lipase to determine if this method was applicable for industrial biodiesel production. When biodiesel was produced repeatedly, the conversion rate was maintained at over 85% after eight reuses.

  12. Determining

    Directory of Open Access Journals (Sweden)

    Bahram Andarzian

    2015-06-01

    Full Text Available Wheat production in the south of Khuzestan, Iran is constrained by heat stress for late sowing dates. For optimization of yield, sowing at the appropriate time to fit the cultivar maturity length and growing season is critical. Crop models could be used to determine optimum sowing window for a locality. The objectives of this study were to evaluate the Cropping System Model (CSM-CERES-Wheat for its ability to simulate growth, development, grain yield of wheat in the tropical regions of Iran, and to study the impact of different sowing dates on wheat performance. The genetic coefficients of cultivar Chamran were calibrated for the CSM-CERES-Wheat model and crop model performance was evaluated with experimental data. Wheat cultivar Chamran was sown on different dates, ranging from 5 November to 9 January during 5 years of field experiments that were conducted in the Khuzestan province, Iran, under full and deficit irrigation conditions. The model was run for 8 sowing dates starting on 25 October and repeated every 10 days until 5 January using long-term historical weather data from the Ahvaz, Behbehan, Dezful and Izeh locations. The seasonal analysis program of DSSAT was used to determine the optimum sowing window for different locations as well. Evaluation with the experimental data showed that performance of the model was reasonable as indicated by fairly accurate simulation of crop phenology, biomass accumulation and grain yield against measured data. The normalized RMSE were 3%, 2%, 11.8%, and 3.4% for anthesis date, maturity date, grain yield and biomass, respectively. Optimum sowing window was different among locations. It was opened and closed on 5 November and 5 December for Ahvaz; 5 November and 15 December for Behbehan and Dezful;and 1 November and 15 December for Izeh, respectively. CERES-Wheat model could be used as a tool to evaluate the effect of sowing date on wheat performance in Khuzestan conditions. Further model evaluations

  13. Optimization of fuel recovery through the stepwise co-pyrolysis of palm shell and scrap tire

    International Nuclear Information System (INIS)

    Abnisa, Faisal; Wan Daud, Wan Mohd Ashri

    2015-01-01

    Highlights: • The co-pyrolysis of palm shell and scrap tire was studied. • The effect of stepwise co-pyrolysis temperature was investigated. • Co-pyrolysis successfully improved the quantity and quality of product yields. • Stepwise co-pyrolysis slightly increased oil and gas, and decreased char. • The co-pyrolysis of 50% biomass and 50% scrap tire is recommended. - Abstract: This study optimized the use of biomass waste to generate fuel through co-pyrolysis. In this paper, the effects of stepwise co-pyrolysis temperature and different ratios between palm shells and scrap tires in feedstock were studied to observe any improvements in the quantity and quality of the liquid yield and its byproduct. The ratio of palm shells and scrap tires varied at 100:0, 75:25, 50:50, 25:75, and 0:100. The experiment was conducted in a fixed-bed reactor. The study was divided into two scenarios. The first scenario was performed at the optimum temperature of 500 °C with a reaction time of 60 min. In the second scenario, the temperature was set at 500 °C for 60 min before the temperature was increased to 800 °C with a high heating rate. After the temperature reached 800 °C, the condition was maintained for approximately 45 min. Results showed that an increase in the liquid and gas yields was achieved when the temperature increased after optimum conditions. Increased yield was also obtained when the proportion of scrap tire was increased in the feedstock. Several other important findings are discussed in this paper, including the phases of pyrolysis oil, features of the liquid product, and characteristics of the byproducts. All products from both scenarios were analyzed by various methods to understand their fuel characteristics

  14. Dissipated energy and entropy production for an unconventional heat engine: the stepwise `circular cycle'

    Science.gov (United States)

    di Liberto, Francesco; Pastore, Raffaele; Peruggi, Fulvio

    2011-05-01

    When some entropy is transferred, by means of a reversible engine, from a hot heat source to a colder one, the maximum efficiency occurs, i.e. the maximum available work is obtained. Similarly, a reversible heat pumps transfer entropy from a cold heat source to a hotter one with the minimum expense of energy. In contrast, if we are faced with non-reversible devices, there is some lost work for heat engines, and some extra work for heat pumps. These quantities are both related to entropy production. The lost work, i.e. ? , is also called 'degraded energy' or 'energy unavailable to do work'. The extra work, i.e. ? , is the excess of work performed on the system in the irreversible process with respect to the reversible one (or the excess of heat given to the hotter source in the irreversible process). Both quantities are analysed in detail and are evaluated for a complex process, i.e. the stepwise circular cycle, which is similar to the stepwise Carnot cycle. The stepwise circular cycle is a cycle performed by means of N small weights, dw, which are first added and then removed from the piston of the vessel containing the gas or vice versa. The work performed by the gas can be found as the increase of the potential energy of the dw's. Each single dw is identified and its increase, i.e. its increase in potential energy, evaluated. In such a way it is found how the energy output of the cycle is distributed among the dw's. The size of the dw's affects entropy production and therefore the lost and extra work. The distribution of increases depends on the chosen removal process.

  15. Thermodynamic optimization with a finite number of heat intercepts for cryogenic systems with parameters stepwise continuous

    International Nuclear Information System (INIS)

    Bisio, G.

    1992-01-01

    The aim of this paper is to study the thermodynamic optimization by the variation of the heat transfer rate in a finite number of points through insulation for the general case of one-dimensional heat transfer (flat plate, hollow cylinder and hollow sphere) in systems, consisting of different materials in series, whose thermal conductivity is a function of temperature and of the coordinate in the heat flux direction. Besides, some parameters or their first derivative are assumed stepwise continuous. For this purpose, the results of some researches by the author pertinent to the properties of entropy production rate in the one-dimensional heat transfer are utilized

  16. Stepwise optimization and global chaos of nonlinear parameters in exact calculations of few-particle systems

    International Nuclear Information System (INIS)

    Frolov, A.M.

    1986-01-01

    The problem of exact variational calculations of few-particle systems in the exponential basis of the relative coordinates using nonlinear parameters is studied. The techniques of stepwise optimization and global chaos of nonlinear parameters are used to calculate the S and P states of homonuclear muonic molecules with an error of no more than +0.001 eV. The global-chaos technique also has proved to be successful in the case of the nuclear systems 3 H and 3 He

  17. In vivo stepwise multi-photon activation fluorescence imaging of melanin in human skin

    Science.gov (United States)

    Lai, Zhenhua; Gu, Zetong; Abbas, Saleh; Lowe, Jared; Sierra, Heidy; Rajadhyaksha, Milind; DiMarzio, Charles

    2014-03-01

    The stepwise multi-photon activated fluorescence (SMPAF) of melanin is a low cost and reliable method of detecting melanin because the activation and excitation can be a continuous-wave (CW) mode near infrared (NIR) laser. Our previous work has demonstrated the melanin SMPAF images in sepia melanin, mouse hair, and mouse skin. In this study, we show the feasibility of using SMPAF to detect melanin in vivo. in vivo melanin SMPAF images of normal skin and benign nevus are demonstrated. SMPAF images add specificity for melanin detection than MPFM images and CRM images. Melanin SMPAF is a promising technology to enable early detection of melanoma for dermatologists.

  18. Stepwise decision making for the long-term management of radioactive waste

    International Nuclear Information System (INIS)

    Pescatore, C.; Vari, A.

    2003-01-01

    The context of long-term radioactive waste management is being shaped by changes in modern society. Values such as health, environmental protection and safety are increasingly important. This changes in turn necessitate new forms of dialogue and decision-making processes that include a large number of stakeholders. This paper deals with the new features of a stepwise decision-making approach, taking into account the public involvement and social learning processes, and showing the complexity of the new situation. (A.L.B.)

  19. Helicobacter pylori infection-induced H3Ser10 phosphorylation in stepwise gastric carcinogenesis and its clinical implications.

    Science.gov (United States)

    Yang, Tao-Tao; Cao, Na; Zhang, Hai-Hui; Wei, Jian-Bo; Song, Xiao-Xia; Yi, Dong-Min; Chao, Shuai-Heng; Zhang, Li-Da; Kong, Ling-Fei; Han, Shuang-Yin; Yang, Yu-Xiu; Ding, Song-Ze

    2018-04-15

    Our previous works have demonstrated that Helicobacter pylori (Hp) infection can alter histone H3 serine 10 phosphorylation status in gastric epithelial cells. However, whether Helicobacter pylori-induced histone H3 serine 10 phosphorylation participates in gastric carcinogenesis is unknown. We investigate the expression of histone H3 serine 10 phosphorylation in various stages of gastric disease and explore its clinical implication. Stomach biopsy samples from 129 patients were collected and stained with histone H3 serine 10 phosphorylation, Ki67, and Helicobacter pylori by immunohistochemistry staining, expressed as labeling index. They were categorized into nonatrophic gastritis, chronic atrophic gastritis, intestinal metaplasia, low-grade intraepithelial neoplasia, high-grade intraepithelial neoplasia, and intestinal-type gastric cancer groups. Helicobacter pylori infection was determined by either 13 C-urea breath test or immunohistochemistry staining. In Helicobacter pylori-negative patients, labeling index of histone H3 serine 10 phosphorylation was gradually increased in nonatrophic gastritis, chronic atrophic gastritis, intestinal metaplasia groups, peaked at low-grade intraepithelial neoplasia, and declined in high-grade intraepithelial neoplasia and gastric cancer groups. In Helicobacter pylori-infected patients, labeling index of histone H3 serine 10 phosphorylation followed the similar pattern as above, with increased expression over the corresponding Helicobacter pylori-negative controls except in nonatrophic gastritis patient whose labeling index was decreased when compared with Helicobacter pylori-negative control. Labeling index of Ki67 in Helicobacter pylori-negative groups was higher in gastric cancer than chronic atrophic gastritis and low-grade intraepithelial neoplasia groups, and higher in intestinal metaplasia group compared with chronic atrophic gastritis group. In Helicobacter pylori-positive groups, Ki67 labeling index was increased

  20. Stepwise impact of urban wastewater treatment on the bacterial community structure, antibiotic contents, and prevalence of antimicrobial resistance.

    Science.gov (United States)

    Wang, Mingyu; Shen, Weitao; Yan, Lei; Wang, Xin-Hua; Xu, Hai

    2017-12-01

    Bacteria, antibiotics, and antibiotic resistance determinants are key biological pollutants in aquatic systems, which may lead to bacterial infections or prevent the cure of bacterial infections. In this study, we investigated how the wastewater treatment processes in wastewater treatment plants (WWTPs) affect these pollutants. We found that the addition of oxygen, polyaluminum chloride (PAC), and polyacrylamide (PAM), as well as ultraviolet (UV) disinfection could significantly alter the bacterial communities in the water samples. An overall shift from Gram-negative bacteria to Gram-positive bacteria was observed throughout the wastewater treatment steps, but the overall bacterial biomass was not reduced in the WWTP samples. The antibiotic contents were reduced by the WWTP, but the size of the reduction and the step when antibiotic degradation occurred differed among antibiotics. Ciprofloxacin, sulfamethoxazole and erythromycin could be removed completely by the WWTP, whereas cephalexin could not. The removal of ciprofloxacin, cephalexin, and erythromycin occurred in the anaerobic digester, whereas the removal of sulfamethoxazole occurred after the addition of PAC and PAM, and UV disinfection. Antimicrobial resistance determinants were highly prevalent in all of the samples analyzed, except for those targeting vancomycin and colistin. However, wastewater treatment was ineffective at removing antimicrobial resistance determinants from wastewater. There were strong correlations between intI1, floR, sul1, and ermB, thereby suggesting the importance of integrons for the spread of these antimicrobial resistance genes. In general, this study comprised a stepwise analysis of the impact of WWTPs on three biological pollutants: bacteria, antibiotics, and antimicrobial resistance determinants, where our results suggest that the design of WWTPs needs to be improved to address the threats due to these pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Stepwise integral scaling method and its application to severe accident phenomena

    International Nuclear Information System (INIS)

    Ishii, M.; Zhang, G.

    1993-10-01

    Severe accidents in light water reactors are characterized by an occurrence of multiphase flow with complicated phase changes, chemical reaction and various bifurcation phenomena. Because of the inherent difficulties associated with full-scale testing, scaled down and simulation experiments are essential part of the severe accident analyses. However, one of the most significant shortcomings in the area is the lack of well-established and reliable scaling method and scaling criteria. In view of this, the stepwise integral scaling method is developed for severe accident analyses. This new scaling method is quite different from the conventional approach. However, its focus on dominant transport mechanisms and use of the integral response of the system make this method relatively simple to apply to very complicated multi-phase flow problems. In order to demonstrate its applicability and usefulness, three case studies have been made. The phenomena considered are (1) corium dispersion in DCH, (2) corium spreading in BWR MARK-I containment, and (3) incore boil-off and heating process. The results of these studies clearly indicate the effectiveness of their stepwise integral scaling method. Such a simple and systematic scaling method has not been previously available to severe accident analyses

  2. The systemic management of cutaneous dermatomyositis: Results of a stepwise strategy

    Directory of Open Access Journals (Sweden)

    C.O. Anyanwu

    2017-12-01

    Full Text Available Treatment of dermatomyositis (DM is often achieved with a stepwise algorithm. However, the literature lacks quality evidence to support the use of this therapeutic strategy. The result of a stepwise therapeutic strategy in the management of skin-only DM is presented to better understand the clinical outcomes and allow for future studies. A cohort of 102 patients with DM, 41 of whom had skin-only disease, were seen between July 2009 and April 2013 at a referral-based connective tissue disease clinic. The Cutaneous Dermatomyositis Disease Area and Severity Index was used to prospectively assess disease severity and the outcomes in 41 adult patients with skin-only DM were analyzed. Of the 41 patients with skin-only DM, 23 patients (56.1% received antimalarial medications alone and 18 patients (43.9% received second- or third-line agents. Ten patients (24.4% remained at the first level of the treatment algorithm and received only hydroxychloroquine. Prednisone was included in the treatment regimen for 11 patients with skin-only disease (26.8%. The results show that management of cutaneous DM often requires second-line agents because antimalarial medications alone are insufficient to treat most patients with skin-only disease. Keywords: dermatomyositis, antimalarial, immunosuppressive, CDASI, outcome measures, treatment

  3. Stepwise fluorination - a useful approach for the isotopic analysis of hydrous minerals

    Energy Technology Data Exchange (ETDEWEB)

    Haimson, M; Knauth, L P [Arizona State Univ., Tempe (USA). Dept. of Geology

    1983-09-01

    Analytical uncertainties in oxygen isotopic studies of hydrous silica have been investigated using a partial fluorination procedure in which fractional oxygen yields are achieved by reducing the amount of fluorine. Stepwise reaction of opaline silica results in a set of sequential oxygen fractions which show a wide range of delta/sup 18/O values due to variable amounts of water, organic matter, and other impurities. Delta-values for successive fractions in non-biogenic opal systematically increase as water is reacted away and then remain constant to within +- 0.2 per thousand as the remaining silica reacts. Delta-values in biogenic silica increase similarly but then decrease when low /sup 18/O oxide impurities begin to react. The troublesome water component in opal is readily removed by stepwise fluorination. This technique allows more precise oxygen isotope analysis of non-biogenic opal-A, and may improve the analytical precision for biogenic silica and any silicate mineral containing a significant water component.

  4. Differential growth of the northern Tibetan margin: evidence for oblique stepwise rise of the Tibetan Plateau

    Science.gov (United States)

    Wang, Fei; Shi, Wenbei; Zhang, Weibin; Wu, Lin; Yang, Liekun; Wang, Yinzhi; Zhu, Rixiang

    2017-01-01

    Models of how high elevations formed across Tibet predict: (a) the continuous thickening of a “viscous sheet”; (b) time-dependent, oblique stepwise growth; and (c) synchronous deformation across Tibet that accompanied collision. Our new observations may shed light on this issue. Here, we use 40Ar/39Ar and (U-Th)/He thermochronology from massifs in the hanging walls of thrust structures along the Kunlun Belt, the first-order orogenic range at the northern Tibetan margin, to elucidate the exhumation history. The results show that these massifs, and hence the plateau margin, were subject to slow, steady exhumation during the Early Cenozoic, followed by a pulse of accelerated exhumation during 40–35 Ma. The exhumation rate increases westward (from ~0.22 to 0.34 and 0.5 mm/yr). The two-fold increase in exhumation in the western part (0.5 mm/yr) compared to the eastern part suggests westward increases in exhumation and compressional stress along the Kunlun Belt. We relate these observations to the mechanisms responsible for the oblique stepwise rise of Tibet. After collision, oblique subduction beneath Kunlun caused stronger compressional deformation in the western part than in the eastern part, resulting in differential growth and lateral extrusion. PMID:28117351

  5. A modified GFP facilitates counting membrane protein subunits by step-wise photobleaching in Arabidopsis.

    Science.gov (United States)

    Song, Kai; Xue, Yiqun; Wang, Xiaohua; Wan, Yinglang; Deng, Xin; Lin, Jinxing

    2017-06-01

    Membrane proteins exert functions by forming oligomers or molecular complexes. Currently, step-wise photobleaching has been applied to count the fluorescently labelled subunits in plant cells, for which an accurate and reliable control is required to distinguish individual subunits and define the basal fluorescence. However, the common procedure using immobilized GFP molecules is obviously not applicable for analysis in living plant cells. Using the spatial intensity distribution analysis (SpIDA), we found that the A206K mutation reduced the dimerization of GFP molecules. Further ectopic expression of Myristoyl-GFP A206K driven by the endogenous AtCLC2 promoter allowed imaging of individual molecules at a low expression level. As a result, the percentage of dimers in the transgenic pCLC2::Myristoyl-mGFP A206K line was significantly reduced in comparison to that of the pCLC2::Myristoyl-GFP line, confirming its application in defining the basal fluorescence intensity of GFP. Taken together, our results demonstrated that pCLC2::Myristoyl-mGFP A206K can be used as a standard control for monomer GFP, facilitating the analysis of the step-wise photobleaching of membrane proteins in Arabidopsis thaliana. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Numerical study of radial stepwise fuel load reshuffling traveling wave reactor

    International Nuclear Information System (INIS)

    Zhang Dalin; Zheng Meiyin; Tian Wenxi; Qiu Suizheng; Su Guanghui

    2015-01-01

    Traveling wave reactor is a new conceptual fast breeder reactor, which can adopt natural uranium, depleted uranium and thorium directly to realize the self sustainable breeding and burning to achieve very high fuel utilization fraction. Based on the mechanism of traveling wave reactor, a concept of radial stepwise fuel load reshuffling traveling wave reactor was proposed for realistic application. It was combined with the typical design of sodium-cooled fast reactors, with which the asymptotic characteristics of the inwards stepwise fuel load reshuffling were studied numerically in two-dimension. The calculated results show that the asymptotic k_e_f_f parabolically varies with the reshuffling cycle length, while the burnup increases linearly. The highest burnup satisfying the reactor critical condition is 38%. The power peak shifts from the fuel discharging zone (core centre) to the fuel uploading zone (core periphery) and correspondingly the power peaking factor decreases along with the reshuffling cycle length. In addition, at the high burnup case the axial power distribution close to the core centre displays the M-shaped deformation. (authors)

  7. A stepwise-cluster microbial biomass inference model in food waste composting

    International Nuclear Information System (INIS)

    Sun Wei; Huang, Guo H.; Zeng Guangming; Qin Xiaosheng; Sun Xueling

    2009-01-01

    A stepwise-cluster microbial biomass inference (SMI) model was developed through introducing stepwise-cluster analysis (SCA) into composting process modeling to tackle the nonlinear relationships among state variables and microbial activities. The essence of SCA is to form a classification tree based on a series of cutting or mergence processes according to given statistical criteria. Eight runs of designed experiments in bench-scale reactors in a laboratory were constructed to demonstrate the feasibility of the proposed method. The results indicated that SMI could help establish a statistical relationship between state variables and composting microbial characteristics, where discrete and nonlinear complexities exist. Significance levels of cutting/merging were provided such that the accuracies of the developed forecasting trees were controllable. Through an attempted definition of input effects on the output in SMI, the effects of the state variables on thermophilic bacteria were ranged in a descending order as: Time (day) > moisture content (%) > ash content (%, dry) > Lower Temperature (deg. C) > pH > NH 4 + -N (mg/Kg, dry) > Total N (%, dry) > Total C (%, dry); the effects on mesophilic bacteria were ordered as: Time > Upper Temperature (deg. C) > Total N > moisture content > NH 4 + -N > Total C > pH. This study made the first attempt in applying SCA to mapping the nonlinear and discrete relationships in composting processes.

  8. Stepwise Assembly and Characterization of DNA Linked Two-Color Quantum Dot Clusters.

    Science.gov (United States)

    Coopersmith, Kaitlin; Han, Hyunjoo; Maye, Mathew M

    2015-07-14

    The DNA-mediated self-assembly of multicolor quantum dot (QD) clusters via a stepwise approach is described. The CdSe/ZnS QDs were synthesized and functionalized with an amphiphilic copolymer, followed by ssDNA conjugation. At each functionalization step, the QDs were purified via gradient ultracentrifugation, which was found to remove excess polymer and QD aggregates, allowing for improved conjugation yields and assembly reactivity. The QDs were then assembled and disassembled in a stepwise manner at a ssDNA functionalized magnetic colloid, which provided a convenient way to remove unreacted QDs and ssDNA impurities. After assembly/disassembly, the clusters' optical characteristics were studied by fluorescence spectroscopy and the assembly morphology and stoichiometry was imaged via electron microscopy. The results indicate that a significant amount of QD-to-QD energy transfer occurred in the clusters, which was studied as a function of increasing acceptor-to-donor ratios, resulting in increased QD acceptor emission intensities compared to controls.

  9. Stepwise high-throughput virtual screening of Rho kinase inhibitors from natural product library and potential therapeutics for pulmonary hypertension.

    Science.gov (United States)

    Su, Hao; Yan, Ji; Xu, Jian; Fan, Xi-Zhen; Sun, Xian-Lin; Chen, Kang-Yu

    2015-08-01

    Pulmonary hypertension (PH) is a devastating disease characterized by progressive elevation of pulmonary arterial pressure and vascular resistance due to pulmonary vasoconstriction and vessel remodeling. The activation of RhoA/Rho-kinase (ROCK) pathway plays a central role in the pathologic progression of PH and thus the Rho kinase, an essential effector of the ROCK pathway, is considered as a potential therapeutic target to attenuate PH. In the current study, a synthetic pipeline is used to discover new potent Rho inhibitors from various natural products. In the pipeline, the stepwise high-throughput virtual screening, quantitative structure-activity relationship (QSAR)-based rescoring, and kinase assay were integrated. The screening was performed against a structurally diverse, drug-like natural product library, from which six identified compounds were tested to determine their inhibitory potencies agonist Rho by using a standard kinase assay protocol. With this scheme, we successfully identified two potent Rho inhibitors, namely phloretin and baicalein, with activity values of IC50 = 0.22 and 0.95 μM, respectively. Structural examination suggested that complicated networks of non-bonded interactions such as hydrogen bonding, hydrophobic forces, and van der Waals contacts across the complex interfaces of Rho kinase are formed with the screened compounds.

  10. Method validation for determination of gadolinium (III) and diethyl tetraamine pentaacetic acid (DTPA) ligand amount determination in Gd-DTPA contrast agent

    International Nuclear Information System (INIS)

    Rien Ritawidya; Martalena Ramli; Cecep Taufik Rustendi

    2014-01-01

    Gd-DTPA is one of the contrast agent which is important in Magnetic Resonance Imaging (MRI) application. The presence of free Gd (III) ion and free DTPA ligand is extremely toxic in human body. Therefore, it needs a method in order to determine free ion Gd (III) and free DTPA ligand concentration which then MRI would be applicable for clinical purpose. The analytical method that selected for the research was complexometric titration. The research was carried out in order to make validation method of free ion Gd (III) and free DTPA ligand determination, then validation criteria such as % recovery, % coefisien of variance and linearity could be obtained. Some experiments that had been done on determination of free Gd (III) with DTPA resulted in % recovery between 30,33% - 183,59%, the precision from %CV between 2,34% - 35,25% and linearity showed with value of R = 0,9525. Meanwhile on determination of DTPA with Gd (III) resulted in % recovery between 105.15% - 139,12%, %CV between 6,78% - 10,96% and R = 0,9525. Validation result indicates that determination method can not be used as a method to determine free ion Gd(III) and free DTPA ligand in contrast agent. (author)

  11. Accuracy analysis of the thermal diffusivity measurement of molten salts by stepwise heating method

    International Nuclear Information System (INIS)

    Kato, Yoshio; Furukawa, Kazuo

    1976-11-01

    The stepwise heating method for measuring thermal diffusivity of molten salts is based on the electrical heating of a thin metal plate as a plane heat source in the molten salt. In this method, the following estimations on error are of importance: (1) thickness effect of the metal plate, (2) effective length between the plate and a temperature measuring point and (3) effect of the noise on the temperature rise signal. In this report, a measuring apparatus is proposed and measuring conditions are suggested on the basis of error estimations. The measurements for distilled water and glycerine were made first to test the performance; the results agreed well with standard values. The thermal diffusivities of molten NaNO 3 at 320-380 0 C and of molten Li 2 BeF 4 at 470-700 0 C were measured. (auth.)

  12. Examples of Nearly Net Zero Energy Buildings Through One-Step and Stepwise Retrofits

    DEFF Research Database (Denmark)

    Galiotto, Nicolas; Heiselberg, Per; Knudstrup, Mary-Ann

    2012-01-01

    This paper presents the review of eight single-family house retrofit projects. The main objective is to collect and classify several approaches to nearly net zero energy building retrofitting. The selection has been made on the capacity of reaching a nearly net zero energy level via a one......-step or stepwise retrofit process. The review work is part of a more global Ph.D. project and is used as one of the basement of the future research work. The considered approaches have been sorted in two categories. The first approach has a very high use of energy conservation measures and low use of renewable...... energy production measures. The second approach has a lower use of energy conservation measures (but still high compared to a traditional renovation) and a higher use of renewable energy production measures. A third approach to nearly net zero energy building renovation exists but has not been considered...

  13. Step-wise kinetics of natural physical ageing in arsenic selenide glasses

    International Nuclear Information System (INIS)

    Golovchak, R; Kozdras, A; Balitska, V; Shpotyuk, O

    2012-01-01

    The long-term kinetics of physical ageing at ambient temperature is studied in Se-rich As-Se glasses using the conventional differential scanning calorimetry technique. It is analysed through the changes in the structural relaxation parameters occurring during the glass-to-supercooled liquid transition in the heating mode. Along with the time dependences of the glass transition temperature (T g ) and partial area (A) under the endothermic relaxation peak, the enthalpy losses (ΔH) and calculated fictive temperature (T F ) are analysed as key parameters, characterizing the kinetics of physical ageing. The latter is shown to have step-wise character, revealing some kinds of subsequent plateaus and steep regions. A phenomenological description of physical ageing in the investigated glasses is proposed on the basis of an alignment-shrinkage mechanism and first-order kinetic equations.

  14. The stepwise evolution of the exome during acquisition of docetaxel resistance in breast cancer cells

    DEFF Research Database (Denmark)

    Hansen, Stine Ninel; Ehlers, Natasja Spring; Zhu, Shida

    2016-01-01

    Background: Resistance to taxane-based therapy in breast cancer patients is a major clinical problem that may be addressed through insight of the genomic alterations leading to taxane resistance in breast cancer cells. In the current study we used whole exome sequencing to discover somatic genomic...... alterations, evolving across evolutionary stages during the acquisition of docetaxel resistance in breast cancer cell lines. Results: Two human breast cancer in vitro models (MCF-7 and MDA-MB-231) of the step-wise acquisition of docetaxel resistance were developed by exposing cells to 18 gradually increasing...... resistance relevant genomic variation appeared to arise midway towards fully resistant cells corresponding to passage 31 (5 nM docetaxel) for MDA-MB-231 and passage 16 (1.2 nM docetaxel) for MCF-7, and where the cells also exhibited a period of reduced growth rate or arrest, respectively. MCF-7 cell acquired...

  15. A Stepwise Approach: Decreasing Infection in Deep Brain Stimulation for Childhood Dystonic Cerebral Palsy.

    Science.gov (United States)

    Johans, Stephen J; Swong, Kevin N; Hofler, Ryan C; Anderson, Douglas E

    2017-09-01

    Dystonia is a movement disorder characterized by involuntary muscle contractions, which cause twisting movements or abnormal postures. Deep brain stimulation has been used to improve the quality of life for secondary dystonia caused by cerebral palsy. Despite being a viable treatment option for childhood dystonic cerebral palsy, deep brain stimulation is associated with a high rate of infection in children. The authors present a small series of patients with dystonic cerebral palsy who underwent a stepwise approach for bilateral globus pallidus interna deep brain stimulation placement in order to decrease the rate of infection. Four children with dystonic cerebral palsy who underwent a total of 13 surgical procedures (electrode and battery placement) were identified via a retrospective review. There were zero postoperative infections. Using a multistaged surgical plan for pediatric patients with dystonic cerebral palsy undergoing deep brain stimulation may help to reduce the risk of infection.

  16. Stepwise Splitting Growth and Pseudocapacitive Properties of Hierarchical Three-Dimensional Co3O4 Nanobooks

    Directory of Open Access Journals (Sweden)

    Huilong Chen

    2017-04-01

    Full Text Available Three-dimensional hierarchical Co3O4 nanobooks have been synthesized successfully on a large scale by calcining orthorhombic Co(CO30.5(OH·0.11H2O precursors with identical morphologies. Based on the influence of reaction time and urea concentration on the nanostructures of the precursors, a stepwise splitting growth mechanism can be proposed to understand the formation of the 3D nanobooks. The 3D Co3O4 nanobooks exhibit excellent pseudocapacitive performances with specific capacitances of 590, 539, 476, 453, and 421 F/g at current densities of 0.5, 1, 2, 4, and 8 A/g, respectively. The devices can retain ca. 97.4% of the original specific capacitances after undergoing charge–discharge cycle tests 1000 times continuously at 4 A/g.

  17. Stepwise modularization in the construction industry using a bottom-up approach

    DEFF Research Database (Denmark)

    Kudsk, Anders; Grønvold, Martin O'Brien; Olsen, Magnus Holo

    2013-01-01

    The manufacturing industry has experienced a great deal of improvement in efficiency and cost reductions throughout the last centuries. But although there have been improvements in the manufacturing industry, the principles and work methods in the construction industry have stood still for more t...... than a hundred years. Based on principles of mass customization applied in the manufacturing industry, two cases of successful implementation of mass customization and modularization have been investigated as a means of showcasing the possibility to incorporate standardization in parts...... implemented stepwise. The case shows that substantial benefits can be gained through implementing modularized construction. It is especially interesting to note that these benefits are achieved through the development of a module with focus on the internal interfaces. © Kudsk et al.; Licensee Bentham Open....

  18. Solid structures of the stepwise self-assembled copillar[5]arene-based supramolecular polymers

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yeon Sil; Hwang, Seong Min; Shin, Jae Yeon; Paek, Kyung Soo [Dept. of Chemistry, Soongsil University, Seoul (Korea, Republic of)

    2016-10-15

    Development of supramolecular polymer has attracted much interest because of their interesting properties such as stimuli-responsiveness, recycling, self-healing and degradability, and their consequential applications. The essential feature of this class of polymers is the self-assembly of discrete monomeric subunits via non-covalent interactions or dynamic covalent bonds. Among the many monomeric subunits, pillar[n]arenes have been ideal building blocks for the fabrication of polymeric supramolecules because of their intrinsic characteristics. The ring-shaped morphologies in supramolecular polymer P are probably due to the tendency of the end-to-end connection in the solid state of long flexible supramolecular chains. The size increase of nano-rings as the stepwise addition increases might be due to the fact that the linear supramolecular polymer P in solution seems to be maintained until the nano-ring formation by solidification.

  19. A Stepwise ISO-Based TQM Implementation Approach Using ISO 9001:2015

    Directory of Open Access Journals (Sweden)

    Chen Chi-kuang

    2016-12-01

    Full Text Available The lack of an implementation roadmap always deters enterprises from choosing Total Quality Management (TQM as its major management approach. This paper proposes a stepwise ISO-based TQM implementation approach which is based on the notion of the new three-dimensional overall business excellence framework developed by Dahlgaard et al. [1]. The proposed approach consists of nine steps comprising three categories: “TQM faith building”, “TQM tools and techniques learning”, and “system development”. The steps in each of the three categories are arranged to span across the proposed nine-step approach. The ISO 9001:2015 standard is used as a case study to demonstrate the proposed approach. The ideas and benefits of the proposed approach are further discussed in relation to this illustration.

  20. Solid structures of the stepwise self-assembled copillar[5]arene-based supramolecular polymers

    International Nuclear Information System (INIS)

    Park, Yeon Sil; Hwang, Seong Min; Shin, Jae Yeon; Paek, Kyung Soo

    2016-01-01

    Development of supramolecular polymer has attracted much interest because of their interesting properties such as stimuli-responsiveness, recycling, self-healing and degradability, and their consequential applications. The essential feature of this class of polymers is the self-assembly of discrete monomeric subunits via non-covalent interactions or dynamic covalent bonds. Among the many monomeric subunits, pillar[n]arenes have been ideal building blocks for the fabrication of polymeric supramolecules because of their intrinsic characteristics. The ring-shaped morphologies in supramolecular polymer P are probably due to the tendency of the end-to-end connection in the solid state of long flexible supramolecular chains. The size increase of nano-rings as the stepwise addition increases might be due to the fact that the linear supramolecular polymer P in solution seems to be maintained until the nano-ring formation by solidification

  1. A Stepwise Fitting Procedure for automated fitting of Ecopath with Ecosim models

    Directory of Open Access Journals (Sweden)

    Erin Scott

    2016-01-01

    Full Text Available The Stepwise Fitting Procedure automates testing of alternative hypotheses used for fitting Ecopath with Ecosim (EwE models to observation reference data (Mackinson et al. 2009. The calibration of EwE model predictions to observed data is important to evaluate any model that will be used for ecosystem based management. Thus far, the model fitting procedure in EwE has been carried out manually: a repetitive task involving setting >1000 specific individual searches to find the statistically ‘best fit’ model. The novel fitting procedure automates the manual procedure therefore producing accurate results and lets the modeller concentrate on investigating the ‘best fit’ model for ecological accuracy.

  2. A stepwise approach for effective management of chronic pain in autosomal-dominant polycystic kidney disease.

    Science.gov (United States)

    Casteleijn, Niek F; Visser, Folkert W; Drenth, Joost P H; Gevers, Tom J G; Groen, Gerbrand J; Hogan, Marie C; Gansevoort, Ron T

    2014-09-01

    Chronic pain, defined as pain existing for >4-6 weeks, affects >60% of patients with autosomal-dominant polycystic disease (ADPKD). It can have various causes, indirectly or directly related to the increase in kidney and liver volume in these patients. Chronic pain in ADPKD patients is often severe, impacting physical activity and social relationships, and frequently difficult to manage. This review provides an overview of pathophysiological mechanisms that can lead to pain and discusses the sensory innervation of the kidneys and the upper abdominal organs, including the liver. In addition, the results of a systematic literature search of ADPKD-specific treatment options are presented. Based on pathophysiological knowledge and evidence derived from the literature an argumentative stepwise approach for effective management of chronic pain in ADPKD is proposed. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  3. Development of a PROficiency-Based StePwise Endovascular Curricular Training (PROSPECT) Program.

    Science.gov (United States)

    Maertens, Heidi; Aggarwal, Rajesh; Desender, Liesbeth; Vermassen, Frank; Van Herzeele, Isabelle

    2016-01-01

    Focus on patient safety, work-hour limitations, and cost-effective education is putting pressure to improve curricula to acquire minimally invasive techniques during surgical training. This study aimed to design a structured training program for endovascular skills and validate its assessment methods. A PROficiency-based StePwise Endovascular Curricular Training (PROSPECT) program was developed, consisting of e-learning and hands-on simulation modules, focusing on iliac and superficial femoral artery atherosclerotic disease. Construct validity was investigated. Performances were assessed using multiple-choice questionnaires, valid simulation parameters, global rating scorings, and examiner checklists. Feasibility was assessed by passage of 2 final-year medical students through this PROSPECT program. Ghent University Hospital, a tertiary clinical care and academic center in Belgium with general surgery residency program. Senior-year medical students were recruited at Ghent University Hospital. Vascular surgeons were invited to participate during conferences and meetings if they had performed at least 100 endovascular procedures as the primary operator during the last 2 years. Overall, 29 medical students and 20 vascular surgeons participated. Vascular surgeons obtained higher multiple-choice questionnaire scores (median: 24.5-22.0 vs. 15.0-12.0; p train cognitive, technical, and nontechnical endovascular skills was developed. A structured, stepwise, proficiency-based valid endovascular program to train cognitive, technical, and human factor skills has been developed and proven to be feasible. A randomized controlled trial has been initiated to investigate its effect on performances in real life, patient outcomes, and cost-effectiveness. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  4. Morphological and molecular evidence for a stepwise evolutionary transition from teeth to baleen in mysticete whales.

    Science.gov (United States)

    Deméré, Thomas A; McGowen, Michael R; Berta, Annalisa; Gatesy, John

    2008-02-01

    The origin of baleen in mysticete whales represents a major transition in the phylogenetic history of Cetacea. This key specialization, a keratinous sieve that enables filter-feeding, permitted exploitation of a new ecological niche and heralded the evolution of modern baleen-bearing whales, the largest animals on Earth. To date, all formally described mysticete fossils conform to two types: toothed species from Oligocene-age rocks ( approximately 24 to 34 million years old) and toothless species that presumably utilized baleen to feed (Recent to approximately 30 million years old). Here, we show that several Oligocene toothed mysticetes have nutrient foramina and associated sulci on the lateral portions of their palates, homologous structures in extant mysticetes house vessels that nourish baleen. The simultaneous occurrence of teeth and nutrient foramina implies that both teeth and baleen were present in these early mysticetes. Phylogenetic analyses of a supermatrix that includes extinct taxa and new data for 11 nuclear genes consistently resolve relationships at the base of Mysticeti. The combined data set of 27,340 characters supports a stepwise transition from a toothed ancestor, to a mosaic intermediate with both teeth and baleen, to modern baleen whales that lack an adult dentition but retain developmental and genetic evidence of their ancestral toothed heritage. Comparative sequence data for ENAM (enamelin) and AMBN (ameloblastin) indicate that enamel-specific loci are present in Mysticeti but have degraded to pseudogenes in this group. The dramatic transformation in mysticete feeding anatomy documents an apparently rare, stepwise mode of evolution in which a composite phenotype bridged the gap between primitive and derived morphologies; a combination of fossil and molecular evidence provides a multifaceted record of this macroevolutionary pattern.

  5. A stepwise approach to the evaluation and treatment of subclinical hyperthyroidism.

    Science.gov (United States)

    Mai, Vinh Q; Burch, Henry B

    2012-01-01

    To review a stepwise approach to the evaluation and treatment of subclinical hyperthyroidism. English-language articles regarding clinical management of subclinical hyperthyroidism published between 2007 and 2012 were reviewed. Subclinical hyperthyroidism is encountered on a daily basis in clinical practice. When evaluating patients with a suppressed serum thyrotropin value, it is important to exclude other potential etiologies such as overt triiodothyronine toxicosis, drug effect, nonthyroidal illness, and central hypothyroidism. In younger patients with mild thyrotropin suppression, it is acceptable to perform testing again in 3 to 6 months to assess for persistence before performing further diagnostic testing. In older patients or patients with thyrotropin values less than 0.1 mIU/L, diagnostic testing should proceed without delay. Persistence of thyrotropin suppression is more typical of nodular thyroid autonomy, whereas thyroiditis and mild Graves disease frequently resolve spontaneously. The clinical consequences of subclinical hyperthyroidism, such as atrial dysrhythmia, accelerated bone loss, increased fracture rate, and higher rates of cardiovascular mortality, are dependent on age and severity. The decision to treat subclinical hyperthyroidism is directly tied to an assessment of the potential for clinical consequences in untreated disease. Definitive therapy is generally selected for patients with nodular autonomous function, whereas antithyroid drug therapy is more appropriate for mild, persistent Graves disease. The presented stepwise approach to the care of patients presenting with an isolated suppression of serum thyrotropin focuses on the differential diagnosis, a prediction of the likelihood of persistence, an assessment of potential risks posed to the patient, and, finally, a personalized choice of therapy.

  6. Stepwise dynamics of an anionic micellar film - Formation of crown lenses.

    Science.gov (United States)

    Lee, Jongju; Nikolov, Alex; Wasan, Darsh

    2017-06-15

    We studied the stepwise thinning of a microscopic circular foam film formed from an anionic micellar solution of sodium dodecyl sulfate (SDS). The foam film formed from the SDS micellar solution thins in a stepwise manner by the formation and expansion of a dark spot(s) of one layer less than the film thickness. During the last stages of film thinning (e.g., a film with one micellar layer), the dark spot expansion occurs via two steps. Initially, a small dark circular spot inside a film of several microns in size is formed, which expands at a constant rate. Then, a ridge along the expanding spot is formed. As the ridge grows, it becomes unstable and breaks into regular crown lenses, which are seen as white spots in the reflected light at the border of the dark spot with the surrounding thicker film. The Rayleigh type of instability contributes to the formation of the lenses, which results in the increase of the dark spot expansion rate with time. We applied the two-dimensional micellar-vacancy diffusion model and took into consideration the effects of the micellar layering and film volume on the rate of the dark spot expansion [Lee et al., 2016] to predict the rate of the dark spot expansion for a 0.06M SDS film in the presence of lenses. We briefly discuss the Rayleigh type of instability in the case of a 0.06M SDS foam film. The goals of this study are to reveal why the crown lenses are formed during the foam film stratification and to elucidate their effect on the rate of spot expansion. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Aberrant transcriptional networks in step-wise neurogenesis of paroxysmal kinesigenic dyskinesia-induced pluripotent stem cells.

    Science.gov (United States)

    Li, Chun; Ma, Yu; Zhang, Kunshan; Gu, Junjie; Tang, Fan; Chen, Shengdi; Cao, Li; Li, Siguang; Jin, Ying

    2016-08-16

    Paroxysmal kinesigenic dyskinesia (PKD) is an episodic movement disorder with autosomal-dominant inheritance and marked variability in clinical manifestations.Proline-rich transmembrane protein 2 (PRRT2) has been identified as a causative gene of PKD, but the molecular mechanism underlying the pathogenesis of PKD still remains a mystery. The phenotypes and transcriptional patterns of the PKD disease need further clarification. Here, we report the generation and neural differentiation of iPSC lines from two familial PKD patients with c.487C>T (p. Gln163X) and c.573dupT (p. Gly192Trpfs*8) PRRT2 mutations, respectively. Notably, an extremely lower efficiency in neural conversion from PKD-iPSCs than control-iPSCs is observed by a step-wise neural differentiation method of dual inhibition of SMAD signaling. Moreover, we show the high expression level of PRRT2 throughout the human brain and the expression pattern of PRRT2 in other human tissues for the first time. To gain molecular insight into the development of the disease, we conduct global gene expression profiling of PKD cells at four different stages of neural induction and identify altered gene expression patterns, which peculiarly reflect dysregulated neural transcriptome signatures and a differentiation tendency to mesodermal development, in comparison to control-iPSCs. Additionally, functional and signaling pathway analyses indicate significantly different cell fate determination between PKD-iPSCs and control-iPSCs. Together, the establishment of PKD-specific in vitro models and the illustration of transcriptome features in PKD cells would certainly help us with better understanding of the defects in neural conversion as well as further investigations in the pathogenesis of the PKD disease.

  8. A simple conductometric method for trace level determination of brilliant green in water based on β-cyclodextrin and silver nitrate and determination of their thermodynamic parameters

    Directory of Open Access Journals (Sweden)

    Roya Mohammad Zadeh Kakhki

    2014-12-01

    Full Text Available A gravimetric and complexometric titration method based on conductometric technique is presented for the quantitative determination of brilliant green (BG in water. The equilibrium constants and the thermodynamic parameters for the complex formation of β-cyclodextrin (β-CD with brilliant green (BG and precipitation of silver nitrate with BG have been determined by conductivity measurements in water. The results suggest that stable 1:1 complex is formed between BG and β-cyclodextrin and the thermodynamic parameters (ΔHc°,ΔSc° for this complexation reaction have been determined from temperature dependence of the stability constant using the van’t Hoff plots. Based on the obtained results, the conductometric method for the determination of BG in the presence of β-CD at 25 °C was developed in the range of 10−8–10−3 molL−1 and with AgNO3 is 10−3–10−5 molL−1.

  9. Stepwise-activable multifunctional peptide-guided prodrug micelles for cancerous cells intracellular drug release

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing, E-mail: zhangjing@zjut.edu.cn; Li, Mengfei [Zhejiang University of Technology, College of Materials Science and Engineering (China); Yuan, Zhefan [Zhejiang University, Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Department of Chemical and Biological Engineering (China); Wu, Dan; Chen, Jia-da; Feng, Jie, E-mail: fengjie@zjut.edu.cn [Zhejiang University of Technology, College of Materials Science and Engineering (China)

    2016-10-15

    A novel type of stepwise-activable multifunctional peptide-guided prodrug micelles (MPPM) was fabricated for cancerous cells intracellular drug release. Deca-lysine sequence (K{sub 10}), a type of cell-penetrating peptide, was synthesized and terminated with azido-glycine. Then a new kind of molecule, alkyne modified doxorubicin (DOX) connecting through disulfide bond (DOX-SS-alkyne), was synthesized. After coupling via Cu-catalyzed azide–alkyne cycloaddition (CuAAC) click chemistry reaction, reduction-sensitive peptide-guided prodrug was obtained. Due to the amphiphilic property of the prodrug, it can assemble to form micelles. To prevent the nanocarriers from unspecific cellular uptake, the prodrug micelles were subsequently modified with 2,3-dimethyl maleic anhydride to obtain MPPM with a negatively charged outer shell. In vitro studies showed that MPPM could be shielded from cells under psychological environment. However, when arriving at mild acidic tumor site, the cell-penetrating capacity of MPPM would be activated by charge reversal of the micelles via hydrolysis of acid-labile β-carboxylic amides and regeneration of K{sub 10}, which enabled efficient internalization of MPPM by tumor cells as well as following glutathione- and protease-induced drug release inside the cancerous cells. Furthermore, since the guide peptide sequences can be accurately designed and synthesized, it can be easily changed for various functions, such as targeting peptide, apoptotic peptide, even aptamers, only need to be terminated with azido-glycine. This method can be used as a template for reduction-sensitive peptide-guided prodrug for cancer therapy.Graphical abstractA novel type of stepwise-activable multifunctional peptide-guided prodrug micelles (MPPM) was fabricated for selective drug delivery in cancerous cells. MPPM could be shielded from cells under psychological environment. However, when arriving at mild acidic tumor site, the cell-penetrating capacity of MPPM would

  10. Limited hair cell induction from human induced pluripotent stem cells using a simple stepwise method.

    Science.gov (United States)

    Ohnishi, Hiroe; Skerleva, Desislava; Kitajiri, Shin-ichiro; Sakamoto, Tatsunori; Yamamoto, Norio; Ito, Juichi; Nakagawa, Takayuki

    2015-07-10

    Disease-specific induced pluripotent stem cells (iPS) cells are expected to contribute to exploring useful tools for studying the pathophysiology of inner ear diseases and to drug discovery for treating inner ear diseases. For this purpose, stable induction methods for the differentiation of human iPS cells into inner ear hair cells are required. In the present study, we examined the efficacy of a simple induction method for inducing the differentiation of human iPS cells into hair cells. The induction of inner ear hair cell-like cells was performed using a stepwise method mimicking inner ear development. Human iPS cells were sequentially transformed into the preplacodal ectoderm, otic placode, and hair cell-like cells. As a first step, preplacodal ectoderm induction, human iPS cells were seeded on a Matrigel-coated plate and cultured in a serum free N2/B27 medium for 8 days according to a previous study that demonstrated spontaneous differentiation of human ES cells into the preplacodal ectoderm. As the second step, the cells after preplacodal ectoderm induction were treated with basic fibroblast growth factor (bFGF) for induction of differentiation into otic-placode-like cells for 15 days. As the final step, cultured cells were incubated in a serum free medium containing Matrigel for 48 days. After preplacodal ectoderm induction, over 90% of cultured cells expressed the genes that express in preplacodal ectoderm. By culture with bFGF, otic placode marker-positive cells were obtained, although their number was limited. Further 48-day culture in serum free media resulted in the induction of hair cell-like cells, which expressed a hair cell marker and had stereocilia bundle-like constructions on their apical surface. Our results indicate that hair cell-like cells are induced from human iPS cells using a simple stepwise method with only bFGF, without the use of xenogeneic cells. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. A broadly applicable surgical teaching method: evaluation of a stepwise introduction to cataract surgery.

    Science.gov (United States)

    Kloek, Carolyn E; Borboli-Gerogiannis, Sheila; Chang, Kenneth; Kuperwaser, Mark; Newman, Lori R; Lane, Anne Marie; Loewenstein, John I

    2014-01-01

    Although cataract surgery is one of the most commonly performed surgeries in the country, it is a microsurgical procedure that is difficult to learn and to teach. This study aims to assess the effectiveness of a new method for introducing postgraduate year (PGY)-3 ophthalmology residents to cataract surgery. Hospital-based ophthalmology residency program. Retrospective cohort study. PGY-3 and PGY-4 residents of the Harvard Medical School Ophthalmology Residency from graduating years 2010 to 2012. In July 2009, a new method of teaching PGY-3 ophthalmology residents cataract surgery was introduced, which was termed "the stepwise introduction to cataract surgery." This curriculum aimed to train residents to perform steps of cataract surgery by deliberately practicing each of the steps of surgery under a structured curriculum with faculty feedback. Assessment methods included surveys administered to the PGY-4 residents who graduated before the implementation of these measures (n = 7), the residents who participated in the first and second years of the new curriculum (n = 16), faculty who teach PGY-4 residents cataract surgery (n = 8), and review of resident Accreditation Council for Graduate Medical Education surgical logs. Resident survey response rate was 100%. Residents who participated in the new curriculum performed more of each step of cataract surgery in the operating room, spent more time practicing each step of cataract surgery on a cataract surgery simulator during the PGY-3 year, and performed more primary cataract surgeries during the PGY-3 year than those who did not. Faculty survey response rate was 63%. Faculty noted an increase in resident preparedness following implementation of the new curriculum. There was no statistical difference between the precurriculum and postcurriculum groups in the percentage turnover of cataracts for the first 2 cataract surgery rotations of the PGY-4 year of training. The introduction of cataract surgery to PGY-3 residents

  12. Does acid-base equilibrium correlate with remnant liver volume during stepwise liver resection?

    Science.gov (United States)

    Golriz, Mohammad; Abbasi, Sepehr; Fathi, Parham; Majlesara, Ali; Brenner, Thorsten; Mehrabi, Arianeb

    2017-10-01

    Small for size and flow syndrome (SFSF) is one of the most challenging complications following extended hepatectomy (EH). After EH, hepatic artery flow decreases and portal vein flow increases per 100 g of remnant liver volume (RLV). This causes hypoxia followed by metabolic acidosis. A correlation between acidosis and posthepatectomy liver failure has been postulated but not studied systematically in a large animal model or clinical setting. In our study, we performed stepwise liver resections on nine pigs to defined SFSF limits as follows: step 1: segment II/III resection, step 2: segment IV resection, step 3: segment V/VIII resection (RLV: 75, 50, and 25%, respectively). Blood gas values were measured before and after each step using four catheters inserted into the carotid artery, internal jugular vein, hepatic artery, and portal vein. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. EH correlated with reduced BE in the hepatic artery. Pco 2 values increased after 75% resection in the jugular vein. In contrast, arterial Po 2 increased after every resection, whereas the venous Po 2 decreased slightly. There were differences in venous [Formula: see text], BE in the hepatic artery, and Pco 2 in the jugular vein after 75% liver resection. Because 75% resection is the limit for SFSF, these noninvasive blood evaluations may be used to predict SFSF. Further studies with long-term follow-up are required to validate this correlation. NEW & NOTEWORTHY This is the first study to evaluate acid-base parameters in major central and hepatic vessels during stepwise liver resection. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. Extended hepatectomy correlated with reduced BE in the hepatic artery. Because 75% resection is the limit for small for size and flow

  13. Discrimination of Geographical Origin of Asian Garlic Using Isotopic and Chemical Datasets under Stepwise Principal Component Analysis.

    Science.gov (United States)

    Liu, Tsang-Sen; Lin, Jhen-Nan; Peng, Tsung-Ren

    2018-01-16

    Isotopic compositions of δ 2 H, δ 18 O, δ 13 C, and δ 15 N and concentrations of 22 trace elements from garlic samples were analyzed and processed with stepwise principal component analysis (PCA) to discriminate garlic's country of origin among Asian regions including South Korea, Vietnam, Taiwan, and China. Results indicate that there is no single trace-element concentration or isotopic composition that can accomplish the study's purpose and the stepwise PCA approach proposed does allow for discrimination between countries on a regional basis. Sequentially, Step-1 PCA distinguishes garlic's country of origin among Taiwanese, South Korean, and Vietnamese samples; Step-2 PCA discriminates Chinese garlic from South Korean garlic; and Step-3 and Step-4 PCA, Chinese garlic from Vietnamese garlic. In model tests, countries of origin of all audit samples were correctly discriminated by stepwise PCA. Consequently, this study demonstrates that stepwise PCA as applied is a simple and effective approach to discriminating country of origin among Asian garlics. © 2018 American Academy of Forensic Sciences.

  14. An Efficient Stepwise Statistical Test to Identify Multiple Linked Human Genetic Variants Associated with Specific Phenotypic Traits.

    Directory of Open Access Journals (Sweden)

    Iksoo Huh

    Full Text Available Recent advances in genotyping methodologies have allowed genome-wide association studies (GWAS to accurately identify genetic variants that associate with common or pathological complex traits. Although most GWAS have focused on associations with single genetic variants, joint identification of multiple genetic variants, and how they interact, is essential for understanding the genetic architecture of complex phenotypic traits. Here, we propose an efficient stepwise method based on the Cochran-Mantel-Haenszel test (for stratified categorical data to identify causal joint multiple genetic variants in GWAS. This method combines the CMH statistic with a stepwise procedure to detect multiple genetic variants associated with specific categorical traits, using a series of associated I × J contingency tables and a null hypothesis of no phenotype association. Through a new stratification scheme based on the sum of minor allele count criteria, we make the method more feasible for GWAS data having sample sizes of several thousands. We also examine the properties of the proposed stepwise method via simulation studies, and show that the stepwise CMH test performs better than other existing methods (e.g., logistic regression and detection of associations by Markov blanket for identifying multiple genetic variants. Finally, we apply the proposed approach to two genomic sequencing datasets to detect linked genetic variants associated with bipolar disorder and obesity, respectively.

  15. Stepwise Swelling of a Thin Film of Lamellae-Forming Poly(styrene-b-butadiene) in Cyclohexane Vapor

    DEFF Research Database (Denmark)

    Di, Zhenyu; Posselt, Dorthe; Smilgies, Detlef-M.

    2012-01-01

    We investigated the swelling of a thin film of lamellae-forming poly(styrene-b-butadiene) in cyclohexane vapor. The vapor pressure and thus the degree of swelling of the film are increased in a stepwise manner using a custom-built sample cell. The resulting structural changes during and after each...

  16. A Step-wise Approach to the Determination of the Lower Limit of Analysis of the Calibration line

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2008-01-01

    . In addition, a minimum STDEV of measurement was expressed in terms of STDEV’s on slope and on intercept and the calculation was performed by using a modified version of the law of propagation of errors (LPE). The method was validated on experiments of gas chromatography (GC), liquid chromatography (LC......), electrochemistry, flow-injection analysis (FIA), atomic emission spectrometry (AES), flame atomic absorption spectrometry (FAAS) and inductively-coupled-plasma mass-spectrometry (ICP-MS). A novel definition of the ULA was proposed as the concentration where the response started to deviate significantly from......A method is presented of stipulating the extension of the calibration line in analytical chemistry. It is based on a combination of a chemometric data interpretation and a calculation of the minimum standard deviation (STDEV) of experiments. From a depiction of the STDEV of a straight line vs...

  17. Formation of mixed organic layers by stepwise electrochemical reduction of diazonium compounds.

    Science.gov (United States)

    Santos, Luis; Ghilane, Jalal; Lacroix, Jean Christophe

    2012-03-28

    This work describes the formation of a mixed organic layer covalently attached to a carbon electrode. The strategy adopted is based on two successive electrochemical reductions of diazonium salts. First, bithiophene phenyl (BTB) diazonium salt is reduced using host/guest complexation in a water/cyclodextrin (β-CD) solution. The resulting layer consists of grafted BTB oligomers and cyclodextrin that can be removed from the surface. The electrochemical response of several outer-sphere redox probes on such BTB/CD electrodes is close to that of a diode, thanks to the easily p-dopable oligo(BTB) moieties. When CD is removed from the surface, pinholes are created and this diode like behavior is lost. Following this, nitrophenyl (NP) diazonium is reduced to graft a second component. Electrochemical study shows that upon grafting NP insulating moieties, the diode-like behavior of the layer is restored which demonstrates that NP is grafted predominately in the empty spaces generated by β-CD desorption. As a result, a mixed BTB/NP organic layer covalently attached to a carbon electrode is obtained using a stepwise electrochemical reduction of two diazonium compounds.

  18. Multifaceted Modularity: A Key for Stepwise Building of Hierarchical Complexity in Actinide Metal–Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Dolgopolova, Ekaterina A. [Department; Ejegbavwo, Otega A. [Department; Martin, Corey R. [Department; Smith, Mark D. [Department; Setyawan, Wahyu [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Karakalos, Stavros G. [College; Henager, Charles H. [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; zur Loye, Hans-Conrad [Department; Shustova, Natalia B. [Department

    2017-11-07

    Growing necessity for efficient nuclear waste management is a driving force for development of alternative architectures towards fundamental understanding of mechanisms involved in actinide integration inside extended structures. In this manuscript, metal-organic frameworks (MOFs) were investigated as a model system for engineering radionuclide containing materials through utilization of unprecedented MOF modularity, which cannot be replicated in any other type of materials. Through the implementation of recent synthetic advances in the MOF field, hierarchical complexity of An-materials were built stepwise, which was only feasible due to preparation of the first examples of actinide-based frameworks with “unsaturated” metal nodes. The first successful attempts of solid-state metathesis and metal node extension in An-MOFs are reported, and the results of the former approach revealed drastic differences in chemical behavior of extended structures versus molecular species. Successful utilization of MOF modularity also allowed us to structurally characterize the first example of bimetallic An-An nodes. To the best of our knowledge, through combination of solid-state metathesis, guest incorporation, and capping linker installation, we were able to achieve the highest Th wt% in mono- and bi-actinide frameworks with minimal structural density. Overall, combination of a multistep synthetic approach with homogeneous actinide distribution and moderate solvothermal conditions could make MOFs an exceptionally powerful tool to address fundamental questions responsible for chemical behavior of An-based extended structures, and therefore, shed light on possible optimization of nuclear waste administration.

  19. Stepwise decision making and options for retrieval in the Swedish KBS-3 concept

    International Nuclear Information System (INIS)

    Papp, T.

    2000-01-01

    The long time aspect of radioactive waste management has resulted in the adoption in Sweden of an ethical principle that requires present generations to manage radioactive waste in a way that will not burden future generations, and at the same time avoid to unnecessarily hinder future generations to retrieve the waste or take actions to change the disposal system. The present Swedish repository design has been developed to get a high and provable safety and to get a robust repository. A consequence of this has been a high barrier integrity that gives the system a high retrievability. The development of a repository system is a step-wise process, as much of the information on repository performance will only become available as the steps are carried through. In such work, retrievability can be extended also to other steps in handling or conditioning, i.e. indicating a general ability to reverse any step taken. At each decision-step, the confidence in achieving a safe repository has to be balanced against the commitments the step involves. An important factor in this balance is the feasibility of stepping back in the process. Thus, reversibility/retrievability are valuable systems characteristics in decision-making under uncertainty. It is generally agreed that the retrievability option should not be used as an excuse for developing a repository with lower safety levels than otherwise would have been required. In fact, such an action is in practice equivalent to an intentional transfer of burdens to future generations. (author)

  20. A stepwise validation of a wearable system for estimating energy expenditure in field-based research

    International Nuclear Information System (INIS)

    Rumo, Martin; Mäder, Urs; Amft, Oliver; Tröster, Gerhard

    2011-01-01

    Regular physical activity (PA) is an important contributor to a healthy lifestyle. Currently, standard sensor-based methods to assess PA in field-based research rely on a single accelerometer mounted near the body's center of mass. This paper introduces a wearable system that estimates energy expenditure (EE) based on seven recognized activity types. The system was developed with data from 32 healthy subjects and consists of a chest mounted heart rate belt and two accelerometers attached to a thigh and dominant upper arm. The system was validated with 12 other subjects under restricted lab conditions and simulated free-living conditions against indirect calorimetry, as well as in subjects' habitual environments for 2 weeks against the doubly labeled water method. Our stepwise validation methodology gradually trades reference information from the lab against realistic data from the field. The average accuracy for EE estimation was 88% for restricted lab conditions, 55% for simulated free-living conditions and 87% and 91% for the estimation of average daily EE over the period of 1 and 2 weeks

  1. The Hexadehydro-Diels-Alder Cycloisomerization Reaction Proceeds by a Stepwise Mechanism.

    Science.gov (United States)

    Wang, Tao; Niu, Dawen; Hoye, Thomas R

    2016-06-29

    We report here experiments showing that the hexadehydro-Diels-Alder (HDDA) cycloisomerization reaction proceeds in a stepwise manner-i.e., via a diradical intermediate. Judicious use of substituent effects was decisive. We prepared (i) a series of triyne HDDA substrates that differed only in the R group present on the remote terminus of the diynophilic alkyne and (ii) an analogous series of dienophilic alkynes (n-C7H15COC≡CR) for use in classical Diels-Alder (DA) reactions (with 1,3-cyclopentadiene). The R groups were CF3, CHO, COMe/Et, CO2Me, CONMe2/Et2, H, and 1-propynyl. The relative rates of both the HDDA cyclization reactions and the simple DA cycloadditions were measured. The reactivity trends revealed a dramatic difference in the behaviors of the CF3 (slowest HDDA and nearly fastest DA) and 1-propynyl (fastest HDDA and slowest DA) containing members of each series. These differences can be explained by invoking radical-stabilizing energies rather than electron-withdrawing effects as the dominating feature of the HDDA reaction.

  2. Stepwise transformation of the molecular building blocks in a porphyrin-encapsulating metal-organic material

    KAUST Repository

    Zhang, ZhenJie

    2013-04-24

    When immersed in solutions containing Cu(II) cations, the microporous metal-organic material P11 ([Cd4(BPT)4]·[Cd(C 44H36N8)(S)]·[S], BPT = biphenyl-3,4′,5-tricarboxylate) undergoes a transformation of its [Cd 2(COO)6]2- molecular building blocks (MBBs) into novel tetranuclear [Cu4X2(COO)6(S) 2] MBBs to form P11-Cu. The transformation occurs in single-crystal to single-crystal fashion, and its stepwise mechanism was studied by varying the Cd2+/Cu2+ ratio of the solution in which crystals of P11 were immersed. P11-16/1 (Cd in framework retained, Cd in encapsulated porphyrins exchanged) and other intermediate phases were thereby isolated and structurally characterized. P11-16/1 and P11-Cu retain the microporosity of P11, and the relatively larger MBBs in P11-Cu permit a 20% unit cell expansion and afford a higher surface area and a larger pore size. © 2013 American Chemical Society.

  3. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean.

    Science.gov (United States)

    Coxall, Helen K; Wilson, Paul A; Pälike, Heiko; Lear, Caroline H; Backman, Jan

    2005-01-06

    The ocean depth at which the rate of calcium carbonate input from surface waters equals the rate of dissolution is termed the calcite compensation depth. At present, this depth is approximately 4,500 m, with some variation between and within ocean basins. The calcite compensation depth is linked to ocean acidity, which is in turn linked to atmospheric carbon dioxide concentrations and hence global climate. Geological records of changes in the calcite compensation depth show a prominent deepening of more than 1 km near the Eocene/Oligocene boundary (approximately 34 million years ago) when significant permanent ice sheets first appeared on Antarctica, but the relationship between these two events is poorly understood. Here we present ocean sediment records of calcium carbonate content as well as carbon and oxygen isotopic compositions from the tropical Pacific Ocean that cover the Eocene/Oligocene boundary. We find that the deepening of the calcite compensation depth was more rapid than previously documented and occurred in two jumps of about 40,000 years each, synchronous with the stepwise onset of Antarctic ice-sheet growth. The glaciation was initiated, after climatic preconditioning, by an interval when the Earth's orbit of the Sun favoured cool summers. The changes in oxygen-isotope composition across the Eocene/Oligocene boundary are too large to be explained by Antarctic ice-sheet growth alone and must therefore also indicate contemporaneous global cooling and/or Northern Hemisphere glaciation.

  4. The step-wise pathway of septin hetero-octamer assembly in budding yeast.

    Science.gov (United States)

    Weems, Andrew; McMurray, Michael

    2017-05-25

    Septin proteins bind guanine nucleotides and form rod-shaped hetero-oligomers. Cells choose from a variety of available septins to assemble distinct hetero-oligomers, but the underlying mechanism was unknown. Using a new in vivo assay, we find that a stepwise assembly pathway produces the two species of budding yeast septin hetero-octamers: Cdc11/Shs1-Cdc12-Cdc3-Cdc10-Cdc10-Cdc3-Cdc12-Cdc11/Shs1. Rapid GTP hydrolysis by monomeric Cdc10 drives assembly of the core Cdc10 homodimer. The extended Cdc3 N terminus autoinhibits Cdc3 association with Cdc10 homodimers until prior Cdc3-Cdc12 interaction. Slow hydrolysis by monomeric Cdc12 and specific affinity of Cdc11 for transient Cdc12•GTP drive assembly of distinct trimers, Cdc11-Cdc12-Cdc3 or Shs1-Cdc12-Cdc3. Decreasing the cytosolic GTP:GDP ratio increases the incorporation of Shs1 vs Cdc11, which alters the curvature of filamentous septin rings. Our findings explain how GTP hydrolysis controls septin assembly, and uncover mechanisms by which cells construct defined septin complexes.

  5. Stepwise multiphoton activation fluorescence reveals a new method of melanin detection

    Science.gov (United States)

    Lai, Zhenhua; Kerimo, Josef; Mega, Yair; DiMarzio, Charles A.

    2013-06-01

    The stepwise multiphoton activated fluorescence (SMPAF) of melanin, activated by a continuous-wave mode near infrared (NIR) laser, reveals a broad spectrum extending from the visible spectra to the NIR and has potential application for a low-cost, reliable method of detecting melanin. SMPAF images of melanin in mouse hair and skin are compared with conventional multiphoton fluorescence microscopy and confocal reflectance microscopy (CRM). By combining CRM with SMPAF, we can locate melanin reliably. However, we have the added benefit of eliminating background interference from other components inside mouse hair and skin. The melanin SMPAF signal from the mouse hair is a mixture of a two-photon process and a third-order process. The melanin SMPAF emission spectrum is activated by a 1505.9-nm laser light, and the resulting spectrum has a peak at 960 nm. The discovery of the emission peak may lead to a more energy-efficient method of background-free melanin detection with less photo-bleaching.

  6. Stepwise Approach to Problematic Hypoglycemia in Korea: Educational, Technological, and Transplant Interventions

    Directory of Open Access Journals (Sweden)

    Sang-Man Jin

    2017-06-01

    Full Text Available Impaired awareness of hypoglycemia has been found to be prevalent in 20% to 40% of people with type 1 diabetes. If a similar prevalence exists in Koreans with type 1 diabetes, at a minimum, thousands of people with type 1 diabetes suffer at least one unpredicted episode of severe hypoglycemia per year in Korea. For patients with problematic hypoglycemia, an evidence-based stepwise approach was suggested in 2015. The first step is structured education regarding multiple daily injections of an insulin analog, and the second step is adding a technological intervention, such as continuous subcutaneous insulin infusion or real-time continuous glucose monitoring. The next step is a sensor-augmented pump, preferably with a low glucose suspension feature or very frequent contact, and the final step is islet or pancreas transplantation. In Korea, however, none of these treatments are reimbursed by the National Health Insurance, and thus have not been widely implemented. The low prevalence of type 1 diabetes means that Korean physicians are relatively unfamiliar with the new technologies in this field. Therefore, the roles of new technologies and pancreas or islet transplantation in the treatment of problematic hypoglycemia need to be defined in the current clinical setting of Korea.

  7. Modelling of volunteer satisfaction and intention to remain in community service: A stepwise approach

    Science.gov (United States)

    Hasan, Hazlin; Wahid, Sharifah Norhuda Syed; Jais, Mohammad; Ridzuan, Arifi

    2017-05-01

    The purpose of this study is to obtain the most significant model of volunteer satisfaction and intention to remain in community service by using a stepwise approach. Currently, Malaysians, young and old are showing more interests in involving themselves in community service projects, either locally or internationally. This positive movement of serving the needy is somehow being halted by the lack of human and financial resources. Therefore, the trend today sees organizers of such projects depend heavily on voluntary supports as they enable project managers to add and to expand the quantity and diversity of services offered without exhausting the minimal budget available. Volunteers are considered a valuable commodity as the available pool of volunteers may be declining due to various reasons which include the volunteer satisfaction. In tandem with the existing situation, a selected sample of 215 diploma students from one of the public universities in Malaysia, who have been involved in at least one community service project, agreed that everybody should have a volunteering intention in helping others. The findings revealed that the most significant model obtained contains two factors that contributed towards intention to remain in community service; work assignment and organizational support, with work assignment becoming the most significant factor. Further research on the differences of intention to remain in community service between students' stream and gender would be conducted to contribute to the body of knowledge.

  8. Bridge mediated two-electron transfer reactions: Analysis of stepwise and concerted pathways

    International Nuclear Information System (INIS)

    Petrov, E.G.; May, V.

    2004-01-01

    A theory of nonadiabatic donor (D)-acceptor (A) two-electron transfer (TET) mediated by a single regular bridge (B) is developed. The presence of different intermediate two-electron states connecting the reactant state D -- BA with the product state DBA -- results in complex multiexponential kinetics. The conditions are discussed at which a reduction to two-exponential as well as single-exponential kinetics becomes possible. For the latter case the rate K TET is calculated, which describes the bridge-mediated reaction as an effective two-electron D-A transfer. In the limit of small populations of the intermediate TET states D - B - A, DB -- A, D - BA - , and DB - A - , K TET is obtained as a sum of the rates K TET (step) and K TET (sup) . The first rate describes stepwise TET originated by transitions of a single electron. It starts at D -- BA and reaches DBA -- via the intermediate state D - BA - . These transitions cover contributions from sequential as well as superexchange reactions all including reduced bridge states. In contrast, a specific two-electron superexchange mechanism from D -- BA to DBA -- defines K TET (sup) . An analytic dependence of K TET (step) and K TET (sup) on the number of bridging units is presented and different regimes of D-A TET are studied

  9. Gonadoblastoma: evidence for a stepwise progression to dysgerminoma in a dysgenetic ovary.

    Science.gov (United States)

    Pauls, Katharina; Franke, Folker E; Büttner, Reinhard; Zhou, Hui

    2005-09-01

    Gonadoblastomas are neoplasms of dysgenetic gonads which may undergo regression or become overgrown by malignant germ cell tumors (mGCTs). Since little is known about their relationship to normal gonadal development and mGCTs, we studied the phenotype and antigenic profile of gonadoblastomas in comparison with adjacent dysgerminomas and fetal gonads. Three cases of gonadoblastomas and fetal gonads of both sexes were analyzed using oncofetal markers to M2A-antigen (M2A), germ cell alkaline phosphatase (PLAP/GCAP), receptor tyrosine kinase c-kit (c-kit), and somatic angiotensin converting enzyme (sACE) as well as the proliferation marker MIB-1. Morphologically, microfollicular pattern of gonadoblastomas showed a fetal germ cell organization reminiscent of oocytic clusters of fetal ovaries. They contained both cell types, similar to oocytes (M2A-, GCAP-, c-kit+/-, sACE-) and oogonia (M2A+, GCAP+, c-kit+, sACE+). The percentage of germ cells immunoreactive for oncofetal markers and the proliferation index increased from microfollicular over coronary patterns to adjacent dysgerminomas. Supportive cells of gonadoblastomas showed a uniform phenotype (CK18+, vimentin+, sACE+, alpha-inhibin+, M2A-) but in contrast to fetal germ cells lacked a clear equivalence to fetal tissues. Our results show that gonadoblastomas mimic female fetal ovary and exhibit a stepwise progression from follicular pattern to coronary pattern and finally to dysgerminomas.

  10. Prevalence and characteristics of asthma–COPD overlap syndrome identified by a stepwise approach

    Directory of Open Access Journals (Sweden)

    Inoue H

    2017-06-01

    Full Text Available Hiromasa Inoue,1 Takahide Nagase,2 Satoshi Morita,3 Atsushi Yoshida,4 Tatsunori Jinnai,4 Masakazu Ichinose5 1Department of Pulmonary Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 2Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 3Department of Biomedical Statistics and Bioinformatics, Kyoto University Graduate School of Medicine, Kyoto, 4Medical Department, AstraZeneca K.K., Osaka, 5Department of Respiratory Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan Background and objective: There is increasing recognition of asthma–COPD overlap syndrome (ACOS, which shares some features of both asthma and COPD; however, the prevalence and characteristics of ACOS are not well understood. The aim of this study was to investigate the prevalence of ACOS among patients with COPD and its characteristics using a stepwise approach as stated in the recent report of the Global Initiative for Asthma (GINA and the Global Initiative for Chronic Obstructive Lung Disease (GOLD. Methods: This multicenter, cross-sectional, observational study enrolled outpatients who were receiving medical treatment for COPD. Clinical data, including spirometry results, were retrieved from medical records. For symptom assessment, patients were asked to complete the Clinical COPD questionnaire and the modified British Medical Research Council questionnaire. Results: Of the 1,008 patients analyzed, 167 (16.6% had syndromic features of ACOS. Of the total number of patients, 93 and 42 (9.2% and 4.2% also had a predefined clinical variability of ≥12%/≥200 mL and ≥12%/≥400 mL in forced expiratory volume in 1 second (FEV1, respectively, and therefore were identified as having ACOS. Conversely, the number of patients who had either syndromic or spirometric feature of ACOS was 595 (59.0%, ≥12%/≥200 mL FEV1 clinical variability, and 328 patients (32.5%, ≥12%/≥400 m

  11. Cerebral Activations Related to Ballistic, Stepwise Interrupted and Gradually Modulated Movements in Parkinson Patients

    Science.gov (United States)

    Toxopeus, Carolien M.; Maurits, Natasha M.; Valsan, Gopal; Conway, Bernard A.; Leenders, Klaus L.; de Jong, Bauke M.

    2012-01-01

    Patients with Parkinson’s disease (PD) experience impaired initiation and inhibition of movements such as difficulty to start/stop walking. At single-joint level this is accompanied by reduced inhibition of antagonist muscle activity. While normal basal ganglia (BG) contributions to motor control include selecting appropriate muscles by inhibiting others, it is unclear how PD-related changes in BG function cause impaired movement initiation and inhibition at single-joint level. To further elucidate these changes we studied 4 right-hand movement tasks with fMRI, by dissociating activations related to abrupt movement initiation, inhibition and gradual movement modulation. Initiation and inhibition were inferred from ballistic and stepwise interrupted movement, respectively, while smooth wrist circumduction enabled the assessment of gradually modulated movement. Task-related activations were compared between PD patients (N = 12) and healthy subjects (N = 18). In healthy subjects, movement initiation was characterized by antero-ventral striatum, substantia nigra (SN) and premotor activations while inhibition was dominated by subthalamic nucleus (STN) and pallidal activations, in line with the known role of these areas in simple movement. Gradual movement mainly involved antero-dorsal putamen and pallidum. Compared to healthy subjects, patients showed reduced striatal/SN and increased pallidal activation for initiation, whereas for inhibition STN activation was reduced and striatal-thalamo-cortical activation increased. For gradual movement patients showed reduced pallidal and increased thalamo-cortical activation. We conclude that PD-related changes during movement initiation fit the (rather static) model of alterations in direct and indirect BG pathways. Reduced STN activation and regional cortical increased activation in PD during inhibition and gradual movement modulation are better explained by a dynamic model that also takes into account enhanced

  12. Stepwise threshold clustering: a new method for genotyping MHC loci using next-generation sequencing technology.

    Directory of Open Access Journals (Sweden)

    William E Stutz

    Full Text Available Genes of the vertebrate major histocompatibility complex (MHC are of great interest to biologists because of their important role in immunity and disease, and their extremely high levels of genetic diversity. Next generation sequencing (NGS technologies are quickly becoming the method of choice for high-throughput genotyping of multi-locus templates like MHC in non-model organisms. Previous approaches to genotyping MHC genes using NGS technologies suffer from two problems:1 a "gray zone" where low frequency alleles and high frequency artifacts can be difficult to disentangle and 2 a similar sequence problem, where very similar alleles can be difficult to distinguish as two distinct alleles. Here were present a new method for genotyping MHC loci--Stepwise Threshold Clustering (STC--that addresses these problems by taking full advantage of the increase in sequence data provided by NGS technologies. Unlike previous approaches for genotyping MHC with NGS data that attempt to classify individual sequences as alleles or artifacts, STC uses a quasi-Dirichlet clustering algorithm to cluster similar sequences at increasing levels of sequence similarity. By applying frequency and similarity based criteria to clusters rather than individual sequences, STC is able to successfully identify clusters of sequences that correspond to individual or similar alleles present in the genomes of individual samples. Furthermore, STC does not require duplicate runs of all samples, increasing the number of samples that can be genotyped in a given project. We show how the STC method works using a single sample library. We then apply STC to 295 threespine stickleback (Gasterosteus aculeatus samples from four populations and show that neighboring populations differ significantly in MHC allele pools. We show that STC is a reliable, accurate, efficient, and flexible method for genotyping MHC that will be of use to biologists interested in a variety of downstream applications.

  13. Cationic gemini surfactant-assisted synthesis of hollow Au nanostructures by stepwise reductions.

    Science.gov (United States)

    Wang, Wentao; Han, Yuchun; Tian, Maozhang; Fan, Yaxun; Tang, Yongqiang; Gao, Mingyuan; Wang, Yilin

    2013-06-26

    A novel synthetic approach was developed for creating versatile hollow Au nanostructures by stepwise reductions of Au(III) upon the use of cationic gemini surfactant hexamethylene-1,6-bis(dodecyl dimethylammonium bromide) (C12C6C12Br2) as a template agent. It was observed that the Au(I) ions obtained from the reduction of Au(III) by ascorbic acid can assist the gemini surfactant to form vesicles, capsule-like, and tube-like aggregates that subsequently act as soft templates for hollow Au nanostructures upon further reduction of Au(I) to Au(0) by NaBH4. It was demonstrated that the combination of C12C6C12Br2 and Au(I) plays a key role in regulating the structure of the hollow precursors not only because C12C6C12Br2 has a stronger aggregation ability in comparison with its single chain counterpart but also because the electrostatic repulsion between head groups of C12C6C12Br2 is greatly weakened after Au(III) is converted to Au(I), which is in favor of the construction of vesicles, capsule-like, and tube-like aggregates. Compared with solid Au nanospheres, the resultant hollow nanostructures exhibit enhanced electrocatalytic activities in methanol oxidation, following the order of elongated nanocapsule > nanocapsule > nanosphere. Benefiting from balanced interactions between the gemini surfactant and Au(I), this soft-template method may present a facile and versatile approach for the controlled synthesis of Au nanostructures potentially useful for fuel cells and other Au nanodevices.

  14. Cerebral activations related to ballistic, stepwise interrupted and gradually modulated movements in Parkinson patients.

    Directory of Open Access Journals (Sweden)

    Carolien M Toxopeus

    Full Text Available Patients with Parkinson's disease (PD experience impaired initiation and inhibition of movements such as difficulty to start/stop walking. At single-joint level this is accompanied by reduced inhibition of antagonist muscle activity. While normal basal ganglia (BG contributions to motor control include selecting appropriate muscles by inhibiting others, it is unclear how PD-related changes in BG function cause impaired movement initiation and inhibition at single-joint level. To further elucidate these changes we studied 4 right-hand movement tasks with fMRI, by dissociating activations related to abrupt movement initiation, inhibition and gradual movement modulation. Initiation and inhibition were inferred from ballistic and stepwise interrupted movement, respectively, while smooth wrist circumduction enabled the assessment of gradually modulated movement. Task-related activations were compared between PD patients (N = 12 and healthy subjects (N = 18. In healthy subjects, movement initiation was characterized by antero-ventral striatum, substantia nigra (SN and premotor activations while inhibition was dominated by subthalamic nucleus (STN and pallidal activations, in line with the known role of these areas in simple movement. Gradual movement mainly involved antero-dorsal putamen and pallidum. Compared to healthy subjects, patients showed reduced striatal/SN and increased pallidal activation for initiation, whereas for inhibition STN activation was reduced and striatal-thalamo-cortical activation increased. For gradual movement patients showed reduced pallidal and increased thalamo-cortical activation. We conclude that PD-related changes during movement initiation fit the (rather static model of alterations in direct and indirect BG pathways. Reduced STN activation and regional cortical increased activation in PD during inhibition and gradual movement modulation are better explained by a dynamic model that also takes into account

  15. Evidence for a stepwise program of extrathymic T cell development within the human tonsil

    Science.gov (United States)

    McClory, Susan; Hughes, Tiffany; Freud, Aharon G.; Briercheck, Edward L.; Martin, Chelsea; Trimboli, Anthony J.; Yu, Jianhua; Zhang, Xiaoli; Leone, Gustavo; Nuovo, Gerard; Caligiuri, Michael A.

    2012-01-01

    The development of a broad repertoire of T cells, which is essential for effective immune function, occurs in the thymus. Although some data suggest that T cell development can occur extrathymically, many researchers remain skeptical that extrathymic T cell development has an important role in generating the T cell repertoire in healthy individuals. However, it may be important in the setting of poor thymic function or congenital deficit and in the context of autoimmunity, cancer, or regenerative medicine. Here, we report evidence that a stepwise program of T cell development occurs within the human tonsil. We identified 5 tonsillar T cell developmental intermediates: (a) CD34+CD38dimLin– cells, which resemble multipotent progenitors in the bone marrow and thymus; (b) more mature CD34+CD38brightLin– cells; (c) CD34+CD1a+CD11c– cells, which resemble committed T cell lineage precursors in the thymus; (d) CD34–CD1a+CD3–CD11c– cells, which resemble CD4+CD8+ double-positive T cells in the thymus; and (e) CD34–CD1a+CD3+CD11c– cells. The phenotype of each subset closely resembled that of its thymic counterpart. The last 4 populations expressed RAG1 and PTCRA, genes required for TCR rearrangement, and all 5 subsets were capable of ex vivo T cell differentiation. TdT+ cells found within the tonsillar fibrous scaffold expressed CD34 and/or CD1a, indicating that this distinct anatomic region contributes to pre–T cell development, as does the subcapsular region of the thymus. Thus, we provide evidence of a role for the human tonsil in a comprehensive program of extrathymic T cell development. PMID:22378041

  16. Phylogenetic detection of horizontal gene transfer during the step-wise genesis of Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Turenne Christine

    2009-08-01

    Full Text Available Abstract Background In the past decade, the availability of complete genome sequence data has greatly facilitated comparative genomic research aimed at addressing genetic variability within species. More recently, analysis across species has become feasible, especially in genera where genome sequencing projects of multiple species have been initiated. To understand the genesis of the pathogen Mycobacterium tuberculosis within a genus where the majority of species are harmless environmental organisms, we have used genome sequence data from 16 mycobacteria to look for evidence of horizontal gene transfer (HGT associated with the emergence of pathogenesis. First, using multi-locus sequence analysis (MLSA of 20 housekeeping genes across these species, we derived a phylogeny that serves as the basis for HGT assignments. Next, we performed alignment searches for the 3989 proteins of M. tuberculosis H37Rv against 15 other mycobacterial genomes, generating a matrix of 59835 comparisons, to look for genetic elements that were uniquely found in M. tuberculosis and closely-related pathogenic mycobacteria. To assign when foreign genes were likely acquired, we designed a bioinformatic program called mycoHIT (mycobacterial homologue investigation tool to analyze these data in conjunction with the MLSA-based phylogeny. Results The bioinformatic screen predicted that 137 genes had been acquired by HGT at different phylogenetic strata; these included genes coding for metabolic functions and modification of mycobacterial lipids. For the majority of these genes, corroborating evidence of HGT was obtained, such as presence of phage or plasmid, and an aberrant GC%. Conclusion M. tuberculosis emerged through vertical inheritance along with the step-wise addition of genes acquired via HGT events, a process that may more generally describe the evolution of other pathogens.

  17. Single-zircon dating by stepwise Pb-evaporation constrains the Archean history of detrital zircons from the Jack Hills, Western Australia

    International Nuclear Information System (INIS)

    Kober, B.; Lippolt, H.J.; Pidgeon, R.T.

    1989-01-01

    Pb isotope analyses have been carried out on 42 zircon grains from a Western Australian metaconglomerate using stepwise Pb-evaporation directly in the ion source of a thermal ionization mass spectrometer. The metaconglomerate is from the Archean Jack Hills Metasedimentary Belt, and is known from ion microprobe (''SHRIMP'') analyses to contain a complex zircon population with ages between 4.2 Ga and 3.1 Ga. The same complex pattern of ages is found by the Pb evaporation studies. Five grains yielded minimum crystallization ages from 4.17 Ga to 4.07 Ga. The main population appears significantly younger, having been generated at about 3.55-3.3 Ga. The agreement between the two analytical approaches confirms the SHRIMP results and demonstrates the value of the stepwise-evaporation technique in determining the age patterns of mixing zircon populations. In many of the evaporative Pb isotope records the 207/206 ratios remained constant for all evaporation steps, which we interpret as evaporation from concordant zircon phases. However, for the majority of zircons 207/206 ratios increased with increasing evaporation temperature, and usually approached constant values during evaporation at the highest temperatures. This can be attributed to mixing of different radiogenic Pb components from either crystalline zircon phases of different ages or from domains of isotopically disturbed metamict zircon. Present results confirm > 4 Ga zircon ages in the metaconglomerate from the Hack Hills and substantiate formation of crust at a very early stage in the evolution of the earth. Results also confirm a major crust-forming event 3.55-3.3 Ga ago. (orig.)

  18. Structural and Logical Stepwise Design of Mechanism of Implementing the Socio-Economic Policy of the Region

    Directory of Open Access Journals (Sweden)

    Zadorozhneva Yuliya Vladimirovna

    2014-12-01

    Full Text Available The socio-economic policy of the region is characterized in two ways. On the one hand, it is an organizational form of interaction of the entities of regional socio-economic policy. This form defines the specifics of their relations, taking into account the existing conditions, resources and factors. On the other hand, it is a process of purposeful interaction between the entities and the impact on objects by the methods and tools. This process contributes to the spatio-temporal changes in the economic and social status of the regional economic system. Therefore, the structural and logical stepwise design of the mechanism of implementing the socio-economic policy of the region will allow to systematically present the content and the interconnections of its constituent entities. The author comes to the conclusion that the mechanism of implementing the socio-economic policy of the region, based on the subject-object and dynamic approaches, involves the allocation of: actors, objects, and the mechanism of actors interaction and the impact on objects within this policy. This mechanism includes the purpose, objectives, methods and tools for their achievement, as well as information and analytical system of monitoring and integrated evaluation, on the basis of which a decision is made on the effectiveness of socio-economic policy and the need for adjusting the initial goal and objectives, or choice of methods and tools for its implementation. This is reflected in the author’s structural and logical scheme of the considered mechanism, the practical significance of which lies in the ability to project in detail the main stages of implementation of socio-economic policy of the region on the basis of the principles of consistency, adequacy, resources integration, priority character, efficiency, responsibility. Each step of the suggested mechanism corresponds to the definite level of functional and structural organization – program

  19. Stepwise hydrogeological characterisation utilising a geo-synthesis methodology - A case study from the Mizunami Underground Research Laboratory Project

    International Nuclear Information System (INIS)

    Saegusa, H.; Osawa, H.; Onoe, H.; Ohyama, T.; Takeuchi, R.; Takeuchi, S.

    2009-01-01

    The Mizunami Underground Research Laboratory (MIU) is now under construction by Japan Atomic Energy Agency (JAEA) in the Cretaceous Toki granite in the Tono area of central Japan. One of the main goals of the MIU project, which is a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes, is to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. For this purpose, a geo-synthesis methodology has been developed and will be tested in a dry run to determine if it produces the data required for repository design and associated integrated safety assessment modelling. Surface-based hydrogeological characterisation, intended to develop conceptual models of the deep geological environment based on an understanding of the undisturbed conditions before excavation of this URL, was carried out in a stepwise manner. This allows field investigations, construction of geological and hydrogeological models and interpretation of resultant groundwater flow simulations to develop in an iterative manner. Investigations have the goal of obtaining information on factors relevant to repository design, associated construction, operational and postclosure safety assessment, evaluation of the practicality of implementation and environmental impact assessment. Such factors include bulk hydraulic conductivity, the locations and properties of water conducting features, direct and indirect indicators of regional and local flow (e.g. based on chemistry or isotopes), etc. Following evaluation of pre-existing site information, field investigations began with fault mapping. This was followed by reflection seismic and vertical seismic profile surveys. In addition, a large programme of investigations was carried out in boreholes, including cross-hole tomography and hydraulic tests. Such input is utilised for the construction

  20. Quantifying the Sub-Cellular Distributions of Gold Nanospheres Uptaken by Cells through Stepwise, Site-Selective Etching.

    Science.gov (United States)

    Xia, Younan; Huo, Da

    2018-04-10

    A quantitative understanding of the sub-cellular distributions of nanoparticles uptaken by cells is important to the development of nanomedicine. With Au nanospheres as a model system, here we demonstrate, for the first time, how to quantify the numbers of nanoparticles bound to plasma membrane, accumulated in cytosol, and entrapped in lysosomes, respectively, through stepwise, site-selective etching. Our results indicate that the chance for nanoparticles to escape from lysosomes is insensitive to the presence of targeting ligand although ligand-receptor binding has been documented as a critical factor in triggering internalization. Furthermore, the presence of serum proteins is shown to facilitate the binding of nanoparticles to plasma membrane lacking the specific receptor. Collectively, these findings confirm the potential of stepwise etching in quantitatively analyzing the sub-cellular distributions of nanoparticles uptaken by cells in an effort to optimize the therapeutic effect. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Stepwise hydrochloric acid extraction of monazite hydroxides for the recovery of cerium lean rare earths, cerium, uranium and thorium

    International Nuclear Information System (INIS)

    Swaminathan, T.V.; Nair, V.R.; John, C.V.

    1988-01-01

    Monazite sand is normally processed by the caustic soda route to produce mixed rare earth chloride, thorium hydroxide and trisodium phosphate. Bulk of the mixed rare earth chloride is used for the preparation of FC catalysts. Recently some of the catalyst producers have shown preference to cerium depleted (lanthanum enriched) rare earth chloride rather than the natural rare earth chloride obtained from monazite. Therefore, a process for producing cerium depleted rare earth chloride, cerium, thorium and uranium from rare earth + thorium hydroxide obtained by treating monazite, based on stepwise hydrochloric acid extraction, was developed in the authors laboratory. The process involves drying of the mixed rare earth-thorium hydroxide cake obtained by monazite-caustic soda process followed by stepwise extraction of the dried cake with hydrochloric acid under specified conditions

  2. High performance yellow organic electroluminescent devices by doping iridium(III) complex into host materials with stepwise energy levels

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Rongzhen; Zhou, Liang, E-mail: zhoul@ciac.ac.cn; Jiang, Yunlong; Li, Yanan; Zhao, Xuesen; Zhang, Hongjie, E-mail: hongjie@ciac.ac.cn

    2015-10-15

    In this work, we aim to further improve the electroluminescent (EL) performances of a yellow light-emitting iridium(III) complex by designing double light-emitting layers (EMLs) devices having stepwise energy levels. Compared with single-EML devices, these designed double-EML devices showed improved EL efficiency and brightness attributed to better balance in carriers. In addition, the stepwise distribution in energy levels of host materials is instrumental in broadening the recombination zone, thus delaying the roll-off of EL efficiency. Based on the investigation of carriers' distribution, device structure was further optimized by adjusting the thickness of deposited layers. Finally, yellow EL device (Commission Internationale de l'Eclairage (CIE) coordinates of (0.446, 0.542)) with maximum current efficiency, power efficiency and brightness up to 78.62 cd/A (external quantum efficiency (EQE) of 21.1%), 82.28 lm/W and 72,713 cd/m{sup 2}, respectively, was obtained. Even at the high brightness of 1000 cd/m{sup 2}, EL efficiency as high as 65.54 cd/A (EQE=17.6%) can be retained. - Highlights: • Yellow electroluminescent devices were designed and fabricated. • P-type and n-type materials having stepwise energy levels were chosen as host materials. • Better balance of holes and electrons causes the enhanced efficiencies. • Improved carriers' trapping suppresses the emission of host material.

  3. Development and implementation of the Caribbean Laboratory Quality Management Systems Stepwise Improvement Process (LQMS-SIP) Towards Accreditation.

    Science.gov (United States)

    Alemnji, George; Edghill, Lisa; Guevara, Giselle; Wallace-Sankarsingh, Sacha; Albalak, Rachel; Cognat, Sebastien; Nkengasong, John; Gabastou, Jean-Marc

    2017-01-01

    Implementing quality management systems and accrediting laboratories in the Caribbean has been a challenge. We report the development of a stepwise process for quality systems improvement in the Caribbean Region. The Caribbean Laboratory Stakeholders met under a joint Pan American Health Organization/US Centers for Disease Control and Prevention initiative and developed a user-friendly framework called 'Laboratory Quality Management System - Stepwise Improvement Process (LQMS-SIP) Towards Accreditation' to support countries in strengthening laboratory services through a stepwise approach toward fulfilling the ISO 15189: 2012 requirements. This approach consists of a three-tiered framework. Tier 1 represents the minimum requirements corresponding to the mandatory criteria for obtaining a licence from the Ministry of Health of the participating country. The next two tiers are quality improvement milestones that are achieved through the implementation of specific quality management system requirements. Laboratories that meet the requirements of the three tiers will be encouraged to apply for accreditation. The Caribbean Regional Organisation for Standards and Quality hosts the LQMS-SIP Secretariat and will work with countries, including the Ministry of Health and stakeholders, including laboratory staff, to coordinate and implement LQMS-SIP activities. The Caribbean Public Health Agency will coordinate and advocate for the LQMS-SIP implementation. This article presents the Caribbean LQMS-SIP framework and describes how it will be implemented among various countries in the region to achieve quality improvement.

  4. Stepwise crystallization and the layered distribution in crystallization kinetics of ultra-thin poly(ethylene terephthalate) film

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Biao, E-mail: chemizuo@zstu.edu.cn, E-mail: wxinping@yahoo.com; Xu, Jianquan; Sun, Shuzheng; Liu, Yue; Yang, Juping; Zhang, Li; Wang, Xinping, E-mail: chemizuo@zstu.edu.cn, E-mail: wxinping@yahoo.com [Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of the Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2016-06-21

    Crystallization is an important property of polymeric materials. In conventional viewpoint, the transformation of disordered chains into crystals is usually a spatially homogeneous process (i.e., it occurs simultaneously throughout the sample), that is, the crystallization rate at each local position within the sample is almost the same. Here, we show that crystallization of ultra-thin poly(ethylene terephthalate) (PET) films can occur in the heterogeneous way, exhibiting a stepwise crystallization process. We found that the layered distribution of glass transition dynamics of thin film modifies the corresponding crystallization behavior, giving rise to the layered distribution of the crystallization kinetics of PET films, with an 11-nm-thick surface layer having faster crystallization rate and the underlying layer showing bulk-like behavior. The layered distribution in crystallization kinetics results in a particular stepwise crystallization behavior during heating the sample, with the two cold-crystallization temperatures separated by up to 20 K. Meanwhile, interfacial interaction is crucial for the occurrence of the heterogeneous crystallization, as the thin film crystallizes simultaneously if the interfacial interaction is relatively strong. We anticipate that this mechanism of stepwise crystallization of thin polymeric films will allow new insight into the chain organization in confined environments and permit independent manipulation of localized properties of nanomaterials.

  5. Relationships between the structure of wheat gluten and ACE inhibitory activity of hydrolysate: stepwise multiple linear regression analysis.

    Science.gov (United States)

    Zhang, Yanyan; Ma, Haile; Wang, Bei; Qu, Wenjuan; Wali, Asif; Zhou, Cunshan

    2016-08-01

    Ultrasound pretreatment of wheat gluten (WG) before enzymolysis can improve the angiotensin converting enzyme (ACE) inhibitory activity of the hydrolysates by alerting the structure of substrate proteins. Establishment of a relationship between the structure of WG and ACE inhibitory activity of the hydrolysates to judge the end point of the ultrasonic pretreatment is vital. The results of stepwise multiple linear regression (MLR) showed that the contents of free sulfhydryl, α-helix, disulfide bond, surface hydrophobicity and random coil were significantly correlated to ACE Inhibitory activity of the hydrolysate, with the standard partial regression coefficients were 3.729, -0.676, -0.252, 0.022 and 0.156, respectively. The R(2) of this model was 0.970. External validation showed that the stepwise MLR model could well predict the ACE inhibitory activity of hydrolysate based on the content of free sulfhydryl, α-helix, disulfide bond, surface hydrophobicity and random coil of WG before hydrolysis. A stepwise multiple linear regression model describing the quantitative relationships between the structure of WG and the ACE Inhibitory activity of the hydrolysates was established. This model can be used to predict the endpoint of the ultrasonic pretreatment. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  6. Application of the modified chi-square ratio statistic in a stepwise procedure for cascade impactor equivalence testing.

    Science.gov (United States)

    Weber, Benjamin; Lee, Sau L; Delvadia, Renishkumar; Lionberger, Robert; Li, Bing V; Tsong, Yi; Hochhaus, Guenther

    2015-03-01

    Equivalence testing of aerodynamic particle size distribution (APSD) through multi-stage cascade impactors (CIs) is important for establishing bioequivalence of orally inhaled drug products. Recent work demonstrated that the median of the modified chi-square ratio statistic (MmCSRS) is a promising metric for APSD equivalence testing of test (T) and reference (R) products as it can be applied to a reduced number of CI sites that are more relevant for lung deposition. This metric is also less sensitive to the increased variability often observed for low-deposition sites. A method to establish critical values for the MmCSRS is described here. This method considers the variability of the R product by employing a reference variance scaling approach that allows definition of critical values as a function of the observed variability of the R product. A stepwise CI equivalence test is proposed that integrates the MmCSRS as a method for comparing the relative shapes of CI profiles and incorporates statistical tests for assessing equivalence of single actuation content and impactor sized mass. This stepwise CI equivalence test was applied to 55 published CI profile scenarios, which were classified as equivalent or inequivalent by members of the Product Quality Research Institute working group (PQRI WG). The results of the stepwise CI equivalence test using a 25% difference in MmCSRS as an acceptance criterion provided the best matching with those of the PQRI WG as decisions of both methods agreed in 75% of the 55 CI profile scenarios.

  7. Multi-layered nanoparticles for penetrating the endosome and nuclear membrane via a step-wise membrane fusion process.

    Science.gov (United States)

    Akita, Hidetaka; Kudo, Asako; Minoura, Arisa; Yamaguti, Masaya; Khalil, Ikramy A; Moriguchi, Rumiko; Masuda, Tomoya; Danev, Radostin; Nagayama, Kuniaki; Kogure, Kentaro; Harashima, Hideyoshi

    2009-05-01

    Efficient targeting of DNA to the nucleus is a prerequisite for effective gene therapy. The gene-delivery vehicle must penetrate through the plasma membrane, and the DNA-impermeable double-membraned nuclear envelope, and deposit its DNA cargo in a form ready for transcription. Here we introduce a concept for overcoming intracellular membrane barriers that involves step-wise membrane fusion. To achieve this, a nanotechnology was developed that creates a multi-layered nanoparticle, which we refer to as a Tetra-lamellar Multi-functional Envelope-type Nano Device (T-MEND). The critical structural elements of the T-MEND are a DNA-polycation condensed core coated with two nuclear membrane-fusogenic inner envelopes and two endosome-fusogenic outer envelopes, which are shed in stepwise fashion. A double-lamellar membrane structure is required for nuclear delivery via the stepwise fusion of double layered nuclear membrane structure. Intracellular membrane fusions to endosomes and nuclear membranes were verified by spectral imaging of fluorescence resonance energy transfer (FRET) between donor and acceptor fluorophores that had been dually labeled on the liposome surface. Coating the core with the minimum number of nucleus-fusogenic lipid envelopes (i.e., 2) is essential to facilitate transcription. As a result, the T-MEND achieves dramatic levels of transgene expression in non-dividing cells.

  8. Stepwise adsorption of phenanthrene at the fly ash-water interface as affected by solution chemistry: experimental and modeling studies.

    Science.gov (United States)

    An, Chunjiang; Huang, Guohe

    2012-11-20

    Fly ash (FA) is predominantly generated from coal-fired power plants. Contamination during disposal of FA can cause significant environmental problems. Knowledge about the interaction of FA and hydrophobic organic pollutants in the environment is very limited. This study investigated the adsorption of phenanthrene at the interface of FA and water. The performance of phenanthrene adsorption on FA and the effects of various aqueous chemistry conditions were evaluated. The adsorption isotherms exhibited an increasing trend in the adsorbed amounts of phenanthrene, while a stepwise pattern was apparent. A stepwise multisite Langmuir model was developed to simulate the stepwise adsorption process. The adsorption of phenanthrene onto FA was noted to be spontaneous at all temperatures. The thermodynamic results indicated that the adsorption was an exothermic process. The adsorption capacity gradually decreased as pH increased from 4 to 8; however, this trend became less significant when pH was changed from 8 to 10. The binding affinity of phenanthrene to FA increased after the addition of humic acid (HA). The pH variation was also responsible for the changes of phenanthrene adsorption on FA in the presence of HA. High ionic strength corresponded to low mobility of phenanthrene in the FA-water system. Results of this study can help reveal the migration patterns of organic contaminants in the FA-water system and facilitate environmental risk assessment at FA disposal sites.

  9. Finding Structure in Diversity: A Stepwise Small-N/Medium-N Qualitative Comparative Analysis Approach for Water Resources Management Research

    Directory of Open Access Journals (Sweden)

    Peter P. Mollinga

    2014-02-01

    Full Text Available Drawing particularly on recent debates on, and development of, comparative methods in the field of comparative politics, the paper argues that stepwise small-N/medium-N qualitative comparative analysis (QCA is a particularly suitable methodological approach for water resources studies because it can make use of the rich but fragmented water resources studies literature for accumulation of knowledge and development of theory. It is suggested that taking an explicit critical realist ontological and epistemological stance allows expansion of the scope of stepwise small-N/medium-N QCA beyond what is claimed for it in Ragin’s 'configurational comparative methods (CCM' perspective for analysing the complexity of causality as 'multiple conjunctural causation'. In addition to explanation of certain sets of 'outcomes' as in CCM’s combinatorial, set-theoretic approach, embedding stepwise small-N/medium-N QCA in a critical realist ontology allows the method to contribute to development of theory on (qualitative differences between the structures in society that shape water resources use, management and governance.

  10. Analytical methods for fissionable material determinations in the nuclear fuel cycle. Progress report, October 1, 1977--September 30, 1978

    International Nuclear Information System (INIS)

    Waterbury, G.R.

    1979-01-01

    Work has continued on the development of dissolution techniques for difficult-to-dissolve nuclear materials, development of methods and automated instruments for plutonium and uranium determinations, preparation of plutonium-containing materials for the Safeguards Analytical Laboratory Evaluation (SALE) program, preparation of plutonium materials for distribution by the National Bureau of Standards (NBS) as standard reference materials (SRMs), measurement of longer plutonium isotope half-lives, and analysis of SALE uranium materials. New tasks include the development of methods and automated instruments for the determination of thorium and uranium, and an evaluation of the ion-exchange-bead technique for the mass spectrometric measurement of uranium and plutonium isotope distributions. Completed tasks include the measurements of ion exchange distributions of over 50 elements on cation exchange resins from nitric acid media and anion exchange resins from hydrobromic and hydriodic acid media. Using a newly developed procedure, the LASL automated spectrophotometer was modified to determine microgram levels of uranium and to determine milligram levels of uranium and plutonium. Construction of an automated controlled-potential analyzer for the determination of plutonium is nearing completion. Apparatus and procedures for the separation and complexometric titration of thorium and uranium are being developed

  11. Stepwise decision making for the long-term management of radioactive waste

    International Nuclear Information System (INIS)

    Pescatore, C.; Vari, A.

    2005-01-01

    increasingly being given to the better understanding of concepts such as 'stepwise decision making' and 'adaptive staging' in which the public, and especially the most affected local public, are meaningfully involved in the planning process. (author)

  12. Multimodal microscopy and the stepwise multi-photon activation fluorescence of melanin

    Science.gov (United States)

    Lai, Zhenhua

    The author's work is divided into three aspects: multimodal microscopy, stepwise multi-photon activation fluorescence (SMPAF) of melanin, and customized-profile lenses (CPL) for on-axis laser scanners, which will be introduced respectively. A multimodal microscope provides the ability to image samples with multiple modalities on the same stage, which incorporates the benefits of all modalities. The multimodal microscopes developed in this dissertation are the Keck 3D fusion multimodal microscope 2.0 (3DFM 2.0), upgraded from the old 3DFM with improved performance and flexibility, and the multimodal microscope for targeting small particles (the "Target" system). The control systems developed for both microscopes are low-cost and easy-to-build, with all components off-the-shelf. The control system have not only significantly decreased the complexity and size of the microscope, but also increased the pixel resolution and flexibility. The SMPAF of melanin, activated by a continuous-wave (CW) mode near-infrared (NIR) laser, has potential applications for a low-cost and reliable method of detecting melanin. The photophysics of melanin SMPAF has been studied by theoretical analysis of the excitation process and investigation of the spectra, activation threshold, and photon number absorption of melanin SMPAF. SMPAF images of melanin in mouse hair and skin, mouse melanoma, and human black and white hairs are compared with images taken by conventional multi-photon fluorescence microscopy (MPFM) and confocal reflectance microscopy (CRM). SMPAF images significantly increase specificity and demonstrate the potential to increase sensitivity for melanin detection compared to MPFM images and CRM images. Employing melanin SMPAF imaging to detect melanin inside human skin in vivo has been demonstrated, which proves the effectiveness of melanin detection using SMPAF for medical purposes. Selective melanin ablation with micrometer resolution has been presented using the Target system

  13. Regressão múltipla stepwise e hierárquica em Psicologia Organizacional: aplicações, problemas e soluções Stepwise and hierarchical multiple regression in organizational psychology: Applications, problemas and solutions

    Directory of Open Access Journals (Sweden)

    Gardênia Abbad

    2002-01-01

    Full Text Available Este artigo discute algumas aplicações das técnicas de análise de regressão múltipla stepwise e hierárquica, as quais são muito utilizadas em pesquisas da área de Psicologia Organizacional. São discutidas algumas estratégias de identificação e de solução de problemas relativos à ocorrência de erros do Tipo I e II e aos fenômenos de supressão, complementaridade e redundância nas equações de regressão múltipla. São apresentados alguns exemplos de pesquisas nas quais esses padrões de associação entre variáveis estiveram presentes e descritas as estratégias utilizadas pelos pesquisadores para interpretá-los. São discutidas as aplicações dessas análises no estudo de interação entre variáveis e na realização de testes para avaliação da linearidade do relacionamento entre variáveis. Finalmente, são apresentadas sugestões para lidar com as limitações das análises de regressão múltipla (stepwise e hierárquica.This article discusses applications of stepwise and hierarchical multiple regression analyses to research in organizational psychology. Strategies for identifying type I and II errors, and solutions to potential problems that may arise from such errors are proposed. In addition, phenomena such as suppression, complementarity, and redundancy are reviewed. The article presents examples of research where these phenomena occurred, and the manner in which they were explained by researchers. Some applications of multiple regression analyses to studies involving between-variable interactions are presented, along with tests used to analyze the presence of linearity among variables. Finally, some suggestions are provided for dealing with limitations implicit in multiple regression analyses (stepwise and hierarchical.

  14. A high surface area Zr(IV)-based metal–organic framework showing stepwise gas adsorption and selective dye uptake

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xiu-Liang [Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124 (China); Tong, Minman; Huang, Hongliang [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang, Bin; Gan, Lei [Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124 (China); Yang, Qingyuan [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhong, Chongli [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Jian-Rong, E-mail: jrli@bjut.edu.cn [Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124 (China); State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

    2015-03-15

    Exploitation of new metal–organic framework (MOF) materials with high surface areas has been attracting great attention in related research communities due to their broad potential applications. In this work, a new Zr(IV)-based MOF, [Zr{sub 6}O{sub 4}(OH){sub 4}(eddb){sub 6}] (BUT-30, H{sub 2}eddb=4,4′-(ethyne-1,2-diyl)dibenzoic acid) has been solvothermally synthesized, characterized, and explored for gases and dyes adsorptions. Single-crystal X-ray diffraction analysis demonstrates a three-dimensional cubic framework structure of this MOF, in which each Zr{sub 6}O{sub 4}(OH){sub 4} building unit is linked by 12 linear eddb ligands. BUT-30 has been found stable up to 400 °C and has a Brunauer–Emmett–Teller (BET) surface area as high as 3940.6 m{sup 2} g{sup −1} (based on the N{sub 2} adsorption at 77 K) and total pore volume of 1.55 cm{sup 3} g{sup −1}. It is more interesting that this MOF exhibits stepwise adsorption behaviors for Ar, N{sub 2}, and CO{sub 2} at low temperatures, and selective uptakes towards different ionic dyes. - Graphical abstract: A new Zr(IV)-based MOF with high surface area has been synthesized and structurally characterized, which shows stepwise gas adsorption at low temperature and selective dye uptake from solution. - Highlights: • A new Zr-based MOF was synthesized and structurally characterized. • This MOF shows a higher surface area compared with its analogous UiO-67 and 68. • This MOF shows a rare stepwise adsorption towards light gases at low temperature. • This MOF performs selective uptakes towards cationic dyes over anionic ones. • Using triple-bond spacer is confirmed feasible in enhancing MOF surface areas.

  15. Determination of aluminium in iron ores and ferroalloys by complexometry

    International Nuclear Information System (INIS)

    Tikhonov, V.N.; Grigorovich, L.F.

    1977-01-01

    The present method is based on fusing iron ore samples and ferroalloys with NaOH, leaching of the alloy in water, and complexometric estimation of aluminium in the filtrate by back titration of excess EDTA with a CuSO 4 solution in the presence of a glycine-thymol blue tracer, using NaF to increase selectivity. The final titration point is fixed by means of a photoelectrical titrator. Fifty-fold amounts of Cu(2), Mg, Zn, In, Pb, Fe(3) and Ni, twenty-five-fold amounts of Ca, Sr and Cd, ten-fold amounts of Co, five-fold amounts of Hg(2), Bi and Mo(6), two-fold amounts of Mn, and equal amounts of Ga, Tl(3), Zr, V(5) and W(6) do not impede determination. Determination is impeded by metals that form strong fluoride complexes with Sc, Y, rare-earth elements, Ti(4), Sn(2) and V(4), even when those metals are contained in equal amounts; it is also impeded by equal amounts of Cr(3). The selectivity of the given method has been compared with that of methods involving titration with a solution constituting zinc chloride with xylenol orange and with a solution comprising copper chloride and sulphur chrome-azurol in the presence of cytil trimethyl ammonium. The method is more selective. A hexamethylenetetramine buffer solution has been used to obtain an optimum (pH 6) medium. The above procedure is employed to assay standard ferroboron samles of iron ore

  16. Research and development needs in a step-wise process for the nuclear waste programme in Sweden

    International Nuclear Information System (INIS)

    Ström, A.; Andersson, J.; Ekeroth, E.; Hedin, A.; Pers, K.

    2016-01-01

    Concluding remarks: • The SKB RD&D Programme 2016 − contains an overview of all the measures that may be necessary for treatment and final disposal of nuclear waste from Swedish nuclear reactors and SKB's facilities; − clarifies how research and technology development are justified and evaluated in a step-wise procedure on the basis of the measures planned; − presents a strategic plan for the research and development necessary to establish and implement future activities; − Published as SKB TR 16-15 in December 2016

  17. Does Stepwise Voltage Ramping Protect the Kidney from Injury During Extracorporeal Shockwave Lithotripsy? Results of a Prospective Randomized Trial.

    Science.gov (United States)

    Skuginna, Veronika; Nguyen, Daniel P; Seiler, Roland; Kiss, Bernhard; Thalmann, George N; Roth, Beat

    2016-02-01

    Renal damage is more frequent with new-generation lithotripters. However, animal studies suggest that voltage ramping minimizes the risk of complications following extracorporeal shock wave lithotripsy (SWL). In the clinical setting, the optimal voltage strategy remains unclear. To evaluate whether stepwise voltage ramping can protect the kidney from damage during SWL. A total of 418 patients with solitary or multiple unilateral kidney stones were randomized to receive SWL using a Modulith SLX-F2 lithotripter with either stepwise voltage ramping (n=213) or a fixed maximal voltage (n=205). SWL. The primary outcome was sonographic evidence of renal hematomas. Secondary outcomes included levels of urinary markers of renal damage, stone disintegration, stone-free rate, and rates of secondary interventions within 3 mo of SWL. Descriptive statistics were used to compare clinical outcomes between the two groups. A logistic regression model was generated to assess predictors of hematomas. Significantly fewer hematomas occurred in the ramping group(12/213, 5.6%) than in the fixed group (27/205, 13%; p=0.008). There was some evidence that the fixed group had higher urinary β2-microglobulin levels after SWL compared to the ramping group (p=0.06). Urinary microalbumin levels, stone disintegration, stone-free rate, and rates of secondary interventions did not significantly differ between the groups. The logistic regression model showed a significantly higher risk of renal hematomas in older patients (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.05; p=0.04). Stepwise voltage ramping was associated with a lower risk of hematomas (OR 0.39, 95% CI 0.19-0.80; p=0.01). The study was limited by the use of ultrasound to detect hematomas. In this prospective randomized study, stepwise voltage ramping during SWL was associated with a lower risk of renal damage compared to a fixed maximal voltage without compromising treatment effectiveness. Lithotripsy is a noninvasive

  18. Monitoring during the stepwise implementation of the Swedish deep repository for spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Baeckblom, Goeran [Conrox (Sweden); Almen, Karl-Erik [KEA Geokonsult AB (Sweden)

    2004-03-01

    Monitoring in this report is defined as 'Continuous or repeated observations or measurements of parameters to increase the scientific understanding of the site and the repository, to show compliance with requirements or for adaptation of plans in light of the monitoring results.' The international outlook from IAEA, OECD/NEA, CEC and some country-specific reviews presented in the report forms a necessary background to the Swedish monitoring framework. The implementation of the deep repository in Sweden is executed in phases where monitoring is an inherently integrated activity in the programme. The first phase is the site investigations when Primary Baseline conditions are established. During the following construction phase of the repository, detailed site characterisation continues in conjunction with construction of the access to the deposition area, construction of parts of the deposition area and the central service area. Monitoring is then used to track the changes to the previously established Primary Baseline conditions and distinguishing these imposed changes from natural variations or from other man-made influences. During the initial operation phase, around 200-400 canisters of spent fuel is emplaced and deposition tunnels backfilled. After up-dated evaluations, the phase of regular operation begin, where detailed characterisation, construction of the repository and waste emplacement are concurrent activities. The closure of the repository will take place when all spent fuel has been emplaced, i.e. in the latter part of this century. Monitoring during the stepwise implementation of the repository is executed of several reasons mainly to: describe the Primary Baseline conditions of the repository site, develop and demonstrate understanding of the repository site and the behaviour of engineered barriers, assist in the decision-making process, show compliance with international and national guidelines and regulations. Specific rationales for

  19. Stepwise thermometric titration of free acid and uranyl with single reagent

    International Nuclear Information System (INIS)

    Zamek, M.

    1976-01-01

    The determination is based on the titration of 0.2-1 M Na 2 B 4 O 7 or Li 2 B 4 O 7 at a rate of 2.10 -6 -10 -5 equiv./s. The exothermal reaction H + +OH - =H 2 O is followed by the formation of polynuclear complexes, accompanied by the drop in the temperature of the reaction mixture. The break in the titration curve corresponds to the defined relation UO 2 2+ :OH - (7:3). It is thus possible to determine U also in the organic phase following the extraction of tributylphosphate from an acid medium. The determination is disturbed by easily hydrolyzable ions. The accuracy and correctness of the method is between 0.1-3%. depending on the concentrations of the determined components up to the molar ratio UO 2 2+ : acid 1:100. (M.K.)

  20. Interaction of dependent and non-dependent regions of the acutely injured lung during a stepwise recruitment manoeuvre

    International Nuclear Information System (INIS)

    Gómez-Laberge, Camille; Rettig, Jordan S; Arnold, John H; Wolf, Gerhard K; Smallwood, Craig D; Boyd, Theonia K

    2013-01-01

    The benefit of treating acute lung injury with recruitment manoeuvres is controversial. An impediment to settling this debate is the difficulty in visualizing how distinct lung regions respond to the manoeuvre. Here, regional lung mechanics were studied by electrical impedance tomography (EIT) during a stepwise recruitment manoeuvre in a porcine model with acute lung injury. The following interaction between dependent and non-dependent regions consistently occurred: atelectasis in the most dependent region was reversed only after the non-dependent region became overdistended. EIT estimates of overdistension and atelectasis were validated by histological examination of lung tissue, confirming that the dependent region was primarily atelectatic and the non-dependent region was primarily overdistended. The pulmonary pressure–volume equation, originally designed for modelling measurements at the airway opening, was adapted for EIT-based regional estimates of overdistension and atelectasis. The adaptation accurately modelled the regional EIT data from dependent and non-dependent regions (R 2 > 0.93, P < 0.0001) and predicted their interaction during recruitment. In conclusion, EIT imaging of regional lung mechanics reveals that overdistension in the non-dependent region precedes atelectasis reversal in the dependent region during a stepwise recruitment manoeuvre. (paper)

  1. Effect of Stepwise Doping on Lifetime and Efficiency of Blue and White Phosphorescent Organic Light Emitting Diodes.

    Science.gov (United States)

    Lee, Song Eun; Lee, Ho Won; Lee, Seok Jae; Koo, Ja-ryong; Lee, Dong Hyung; Yang, Hyung Jin; Kim, Hye Jeong; Yoon, Seung Soo; Kim, Young Kwan

    2015-02-01

    We investigated a light emission mechanism of blue phosphorescent organic light emitting diodes (PHOLEDs), using a stepwise doping profile of 2, 8, and 14 wt.% within the emitting layer (EML). We fabricated several blue PHOLEDs with phosphorescent blue emitter iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate doped in N,N'-dicarbazolyl-3,5-benzene as a p-type host material. A blue PHOLED with the highest doping concentration as part of the EML close to an electron transporting layer showed a maximum luminous efficiency of 20.74 cd/A, and a maximum external quantum efficiency of 10.52%. This can be explained by effective electron injection through a highly doped EML side. Additionally, a white OLED based on the doping profile was fabricated with two thin red EMLs within a blue EML maintaining a thickness of 30 nm for the entire EML. Keywords: Blue Phosphorescent Organic Light Emitting Diodes, Stepwise Doping Structure, Charge Trapping Effect.

  2. High-intensity stepwise conditioning programme for improved exercise responses and agility performance of a badminton player with knee pain.

    Science.gov (United States)

    Chen, Bob; Mok, Damon; Lee, Winson C C; Lam, Wing Kai

    2015-02-01

    To examine the effect of a high-intensity stepwise conditioning programme combined with multiple recovery measures on physical fitness, agility, and knee pain symptoms of an injured player. A single case study. University-based conditioning training laboratory. One 26-year-old male world-class badminton player (height, 190.0 cm; weight, 79.3 kg; left dominant hand; playing experience, 16 years; former world champion) with patellar tendinosis and calcification of his left knee. The player received seven conditioning sessions over three weeks. During the programme, there was a gradual increase in training duration and load across sessions while cold therapy, manual stretches and massage were administered after each session to minimise inflammation. The training outcome was evaluated with three different testing methods: standard step test, badminton-specific agility test, and tension-pain rating. The conditioning programme reduced knee pain symptoms and improved actual performance and cardiopulmonary fitness during the agility task. The player was able to return to sport and compete within a month. A high-intensity stepwise conditioning programme improved the physical fitness while sufficient recovery measures minimised any possible undesirable effects and promoted faster return to elite level competition. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Stepwise approach to decision making for long-term radioactive waste management. Experience, issues and guiding principles

    International Nuclear Information System (INIS)

    2004-01-01

    Radioactive waste exists as a result of both past and current practices. One of the most challenging tasks is the management of long-lived waste that must be isolated from the human environment for many thousands, or even hundreds of thousands, of years. Although significant technical progress has been made in developing management schemes that, according to technical experts, would ensure long-term safety (e.g. engineered geologic disposal), the rate of progress towards implementing such solutions has been slower than expected. The contrast between expected and observed rates may be partly attributable to an earlier technical optimism. More significant, however, are the setbacks, which have arisen mainly from an underestimation of the societal and political dimensions. In long-term radioactive waste management, consideration is increasingly being given to concepts such as stepwise decision making and adaptive staging in which the public, and especially the local public, are to be meaningfully involved in the review and planning of developments. The key feature of these concepts is development by steps or stages that are reversible, within the limits of practicability. This is designed to provide reassurance that decisions can be reversed if experience shows them to have adverse or unwanted effects. A stepwise approach to decision making has thus come to the fore as being of value in advancing long-term radioactive waste management solutions in a societally acceptable manner. Despite its early identification within the radioactive waste management community as an important means for reaching solutions and decisions in which there is broad-based confidence, the bases for and application of stepwise decision making has not been widely reviewed. Guiding principles of any such process are still being formulated, its roots in empirical social science research have not been fully reviewed, nor the difficulties of its implementation analysed. The report reviews current

  4. Delineating chalk sand distribution of Ekofisk formation using probabilistic neural network (PNN) and stepwise regression (SWR): Case study Danish North Sea field

    Science.gov (United States)

    Haris, A.; Nafian, M.; Riyanto, A.

    2017-07-01

    Danish North Sea Fields consist of several formations (Ekofisk, Tor, and Cromer Knoll) that was started from the age of Paleocene to Miocene. In this study, the integration of seismic and well log data set is carried out to determine the chalk sand distribution in the Danish North Sea field. The integration of seismic and well log data set is performed by using the seismic inversion analysis and seismic multi-attribute. The seismic inversion algorithm, which is used to derive acoustic impedance (AI), is model-based technique. The derived AI is then used as external attributes for the input of multi-attribute analysis. Moreover, the multi-attribute analysis is used to generate the linear and non-linear transformation of among well log properties. In the case of the linear model, selected transformation is conducted by weighting step-wise linear regression (SWR), while for the non-linear model is performed by using probabilistic neural networks (PNN). The estimated porosity, which is resulted by PNN shows better suited to the well log data compared with the results of SWR. This result can be understood since PNN perform non-linear regression so that the relationship between the attribute data and predicted log data can be optimized. The distribution of chalk sand has been successfully identified and characterized by porosity value ranging from 23% up to 30%.

  5. A Bayesian Stepwise Discriminant Model for Predicting Risk Factors of Preterm Premature Rupture of Membranes: A Case-control Study.

    Science.gov (United States)

    Zhang, Li-Xia; Sun, Yang; Zhao, Hai; Zhu, Na; Sun, Xing-De; Jin, Xing; Zou, Ai-Min; Mi, Yang; Xu, Ji-Ru

    2017-10-20

    Preterm premature rupture of membrane (PPROM) can lead to serious consequences such as intrauterine infection, prolapse of the umbilical cord, and neonatal respiratory distress syndrome. Genital infection is a very important risk which closely related with PPROM. The preliminary study only made qualitative research on genital infection, but there was no deep and clear judgment about the effects of pathogenic bacteria. This study was to analyze the association of infections with PPROM in pregnant women in Shaanxi, China, and to establish Bayesian stepwise discriminant analysis to predict the incidence of PPROM. In training group, the 112 pregnant women with PPROM were enrolled in the case subgroup, and 108 normal pregnant women in the control subgroup using an unmatched case-control method. The sociodemographic characteristics of these participants were collected by face-to-face interviews. Vaginal excretions from each participant were sampled at 28-36+6 weeks of pregnancy using a sterile swab. DNA corresponding to Chlamydia trachomatis (CT), Ureaplasma urealyticum (UU), Candida albicans, group B streptococci (GBS), herpes simplex virus-1 (HSV-1), and HSV-2 were detected in each participant by real-time polymerase chain reaction. A model of Bayesian discriminant analysis was established and then verified by a multicenter validation group that included 500 participants in the case subgroup and 500 participants in the control subgroup from five different hospitals in the Shaanxi province, respectively. The sociological characteristics were not significantly different between the case and control subgroups in both training and validation groups (all P > 0.05). In training group, the infection rates of UU (11.6% vs. 3.7%), CT (17.0% vs. 5.6%), and GBS (22.3% vs. 6.5%) showed statistically different between the case and control subgroups (all P case and control subgroups (P case and control subgroup were 84.1% and 86.8% in the training and validation groups, respectively

  6. Optimization of elution salt concentration in stepwise elution of protein chromatography using linear gradient elution data. Reducing residual protein A by cation-exchange chromatography in monoclonal antibody purification.

    Science.gov (United States)

    Ishihara, Takashi; Kadoya, Toshihiko; Endo, Naomi; Yamamoto, Shuichi

    2006-05-05

    Our simple method for optimization of the elution salt concentration in stepwise elution was applied to the actual protein separation system, which involves several difficulties such as detection of the target. As a model separation system, reducing residual protein A by cation-exchange chromatography in human monoclonal antibody (hMab) purification was chosen. We carried out linear gradient elution experiments and obtained the data for the peak salt concentration of hMab and residual protein A, respectively. An enzyme-linked immunosorbent assay was applied to the measurement of the residual protein A. From these data, we calculated the distribution coefficient of the hMab and the residual protein A as a function of salt concentration. The optimal salt concentration of stepwise elution to reduce the residual protein A from the hMab was determined based on the relationship between the distribution coefficient and the salt concentration. Using the optimized condition, we successfully performed the separation, resulting in high recovery of hMab and the elimination of residual protein A.

  7. Driven Factors Analysis of China’s Irrigation Water Use Efficiency by Stepwise Regression and Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Renfu Jia

    2016-01-01

    Full Text Available This paper introduces an integrated approach to find out the major factors influencing efficiency of irrigation water use in China. It combines multiple stepwise regression (MSR and principal component analysis (PCA to obtain more realistic results. In real world case studies, classical linear regression model often involves too many explanatory variables and the linear correlation issue among variables cannot be eliminated. Linearly correlated variables will cause the invalidity of the factor analysis results. To overcome this issue and reduce the number of the variables, PCA technique has been used combining with MSR. As such, the irrigation water use status in China was analyzed to find out the five major factors that have significant impacts on irrigation water use efficiency. To illustrate the performance of the proposed approach, the calculation based on real data was conducted and the results were shown in this paper.

  8. A Hybrid Approach of Stepwise Regression, Logistic Regression, Support Vector Machine, and Decision Tree for Forecasting Fraudulent Financial Statements

    Directory of Open Access Journals (Sweden)

    Suduan Chen

    2014-01-01

    Full Text Available As the fraudulent financial statement of an enterprise is increasingly serious with each passing day, establishing a valid forecasting fraudulent financial statement model of an enterprise has become an important question for academic research and financial practice. After screening the important variables using the stepwise regression, the study also matches the logistic regression, support vector machine, and decision tree to construct the classification models to make a comparison. The study adopts financial and nonfinancial variables to assist in establishment of the forecasting fraudulent financial statement model. Research objects are the companies to which the fraudulent and nonfraudulent financial statement happened between years 1998 to 2012. The findings are that financial and nonfinancial information are effectively used to distinguish the fraudulent financial statement, and decision tree C5.0 has the best classification effect 85.71%.

  9. A hybrid approach of stepwise regression, logistic regression, support vector machine, and decision tree for forecasting fraudulent financial statements.

    Science.gov (United States)

    Chen, Suduan; Goo, Yeong-Jia James; Shen, Zone-De

    2014-01-01

    As the fraudulent financial statement of an enterprise is increasingly serious with each passing day, establishing a valid forecasting fraudulent financial statement model of an enterprise has become an important question for academic research and financial practice. After screening the important variables using the stepwise regression, the study also matches the logistic regression, support vector machine, and decision tree to construct the classification models to make a comparison. The study adopts financial and nonfinancial variables to assist in establishment of the forecasting fraudulent financial statement model. Research objects are the companies to which the fraudulent and nonfraudulent financial statement happened between years 1998 to 2012. The findings are that financial and nonfinancial information are effectively used to distinguish the fraudulent financial statement, and decision tree C5.0 has the best classification effect 85.71%.

  10. Step-wise changes in glacier flow speed coincide with calving and glacial earthquakes at Helheim Glacier, Greenland

    DEFF Research Database (Denmark)

    Nettles, M.; Larsen, T. B.; Elósegui, P.

    2008-01-01

    Geodetic observations show several large, sudden increases in flow speed at Helheim Glacier, one of Greenland's largest outlet glaciers, during summer, 2007. These step-like accelerations, detected along the length of the glacier, coincide with teleseismically detected glacial earthquakes and major...... iceberg calving events. No coseismic offset in the position of the glacier surface is observed; instead, modest tsunamis associated with the glacial earthquakes implicate glacier calving in the seismogenic process. Our results link changes in glacier velocity directly to calving-front behavior...... at Greenland's largest outlet glaciers, on timescales as short as minutes to hours, and clarify the mechanism by which glacial earthquakes occur. Citation: Nettles, M., et al. (2008), Step-wise changes in glacier flow speed coincide with calving and glacial earthquakes at Helheim Glacier, Greenland....

  11. Application of the step-wise regression procedure to the semi-empirical formulae of the nuclear binding energy

    International Nuclear Information System (INIS)

    Eissa, E.A.; Ayad, M.; Gashier, F.A.B.

    1984-01-01

    Most of the binding energy semi-empirical terms without the deformation corrections used by P.A. Seeger are arranged in a multiple linear regression form. The stepwise regression procedure with 95% confidence levels for acceptance and rejection of variables is applied for seeking a model for calculating binding energies of even-even (E-E) nuclei through a significance testing of each basic term. Partial F-values are taken as estimates for the significance of each term. The residual standard deviation and the overall F-value are used for selecting the best linear regression model. (E-E) nuclei are taken into sets lying between two successive proton and neutron magic numbers. The present work is in favour of the magic number 126 followed by 164 for the neutrons and indecisive in supporting the recently predicted proton magic number 114 rather than the previous one, 126. (author)

  12. Measurement of liquid mixing characteristics in large-sized ion exchange column for isotope separation by stepwise response method

    International Nuclear Information System (INIS)

    Fujine, Sachio; Saito, Keiichiro; Iwamoto, Kazumi; Itoi, Toshiaki.

    1981-07-01

    Liquid mixing in a large-sized ion exchange column for isotope separation was measured by the step-wise response method, using NaCl solution as tracer. A 50 cm diameter column was packed with an ion exchange resin of 200 μm in mean diameter. Experiments were carried out for several types of distributor and collector, which were attached to each end of the column. The smallest mixing was observed for the perforated plate type of the collector, coupled with a minimum stagnant volume above the ion exchange resin bed. The 50 cm diameter column exhibited the better characteristics of liquid mixing than the 2 cm diameter column for which the good performance of lithium isotope separation had already been confirmed. These results indicate that a large increment of throughput is attainable by the scale-up of column diameter with the same performance of isotope separation as for the 2 cm diameter column. (author)

  13. Successful Retrieval of a Dismembered Central Venous Catheter Stuck to the Right Pulmonary Artery Using a Stepwise Approach

    Directory of Open Access Journals (Sweden)

    Keisuke Nakabayashi

    2016-01-01

    Full Text Available Recent advances in anticancer chemotherapy have resulted in an increase in the number of patients requiring a central venous port catheter, and the incidence of catheter pinch-off syndrome has been increasing. Catheter pinch-off syndrome is a rare and unusual complication. It is difficult to retrieve dislodged catheters from the pulmonary artery, especially if the catheter is stuck to the peripheral pulmonary artery. We herein describe the successful removal of a catheter stuck in the pulmonary artery with a stepwise approach. First, a pigtail catheter was used to tug the dislodged catheter in order to free the unilateral end. Then, a gooseneck snare was used to catch and pull the catheter out of the patient. The key to success is to free the end of the catheter.

  14. Modified precision lingual bonding technique: A step-wise approach with torque angulation device-bracket positioning device

    Directory of Open Access Journals (Sweden)

    Rosaline Tina Paul

    2017-01-01

    Full Text Available Objectives: Contemporary preadjusted edgewise appliance is all about the precision in bracket design, prescription and positioning in addition to the orthodontist's skill and training. However, achieving it is a bigger challenge as the anatomy of the lingual surface of a tooth is uneven, dissimilar, and moreover the tooth alignment on the lingual surface is variant. Thus, the need for an accurate method of bracket positioning with predetermined torque and angulation incorporated in the brackets according to the patients' need is of key importance. Materials and Methods: A TAD-BPD machine used to enhance the accuracy of bracket positioning and bioplast accurate tray transfer technique was used. Results: A step-wise procedures in bracket positioning and fabricating an indirect bonding tray for lingual orthodontics using the torque angulation device-bracket positioning device. Conclusions: This technique facilitated unhindered bonding even in severely crowded cases and easy rebonding during mid-treatment stages.

  15. Smoothing effect of the thermal interface material on the temperature distribution in a stepwise varying width microchannel cooling device

    Science.gov (United States)

    Riera, Sara; Barrau, Jérôme; Rosell, Joan I.; Fréchette, Luc G.; Omri, Mohamed; Vilarrubí, Montse; Laguna, Gerard

    2017-09-01

    The impact of the thermal interface material (TIM) layer on the performance of a stepwise varying width microchannel cooling device is analysed. A numerical model shows that the TIM layer, besides its well known negative impact on the temperature, also generates a smoothing effect on the temperature distribution. In this study, an analytical model is used to define a nondimensional parameter, called Smoothing Resistance ratio, as the quotient between the origin of the temperature non uniformities and the TIM thermal resistance that flatten the temperature distribution. The relationship between the temperature uniformity of the cooled device, expressed through the temperature standard deviation, and the Smoothing Resistance ratio is shown to be linear. These results lead to the definition of a new design procedure for this kind of cooling device, which aims to reduce the Smoothing Resistance ratio. Two solutions are identified and their drawbacks are analysed.

  16. A rapid learning and dynamic stepwise updating algorithm for flat neural networks and the application to time-series prediction.

    Science.gov (United States)

    Chen, C P; Wan, J Z

    1999-01-01

    A fast learning algorithm is proposed to find an optimal weights of the flat neural networks (especially, the functional-link network). Although the flat networks are used for nonlinear function approximation, they can be formulated as linear systems. Thus, the weights of the networks can be solved easily using a linear least-square method. This formulation makes it easier to update the weights instantly for both a new added pattern and a new added enhancement node. A dynamic stepwise updating algorithm is proposed to update the weights of the system on-the-fly. The model is tested on several time-series data including an infrared laser data set, a chaotic time-series, a monthly flour price data set, and a nonlinear system identification problem. The simulation results are compared to existing models in which more complex architectures and more costly training are needed. The results indicate that the proposed model is very attractive to real-time processes.

  17. Efficient red organic electroluminescent devices based on trivalent europium complex obtained by designing the device structure with stepwise energy levels

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liang; Jiang, Yunlong; Cui, Rongzhen; Li, Yanan; Zhao, Xuesen; Deng, Ruiping; Zhang, Hongjie, E-mail: hongjie@ciac.ac.cn

    2016-02-15

    In this study, we aim to further enhance the electroluminescence (EL) performances of trivalent europium complex Eu(TTA){sub 3}phen (TTA=thenoyltrifluoroacetone and phen=1,10-phenanthroline) by designing the device structure with stepwise energy levels. The widely used bipolar material 2,6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine (26DCzPPy) was chosen as host material, while the doping concentration of Eu(TTA){sub 3}phen was optimized to be 4%. To facilitate the injection and transport of holes, MoO{sub 3} anode modification layer and 4,4′,4′′-Tris(carbazole-9-yl)triphenylamine (TcTa) hole transport layer were inserted in sequence. Efficient pure red emission with suppressed efficiency roll-off was obtained attributed to the reduction of accumulation holes, the broadening of recombination zone, and the improved balance of holes and electrons on Eu(TTA){sub 3}phen molecules. Finally, the device with 3 nm MoO{sub 3} and 5 nm TcTa obtained the highest brightness of 3278 cd/m{sup 2}, current efficiency of 12.45 cd/A, power efficiency of 11.50 lm/W, and external quantum efficiency of 6.60%. Such a device design strategy helps to improve the EL performances of emitters with low-lying energy levels and provides a chance to simplify device fabrication processes. - Highlights: • Electroluminescent performances of europium complex were further improved. • Device structure with stepwise energy levels was designed. • Better carriers' balance was realized by improving the injection and transport of holes. • The selection of bipolar host caused the broadening of recombination zone.

  18. A model for the stepwise radiation inactivation of the alpha 2-dimer of Na,K-ATPase

    Energy Technology Data Exchange (ETDEWEB)

    Norby, J.G.; Jensen, J. (Univ. of Aarhus (Denmark))

    1989-11-25

    This study is a direct continuation of Jensen, J., and Norby. A new model in which we propose that the in situ organization of the Na,K-ATPase alpha-subunit is an alpha 2-dimer and which describes the stepwise degradation by radiation inactivation of this assembly is presented on the basis of the following findings. Radiation inactivation size for alpha-peptide integrity, normal nucleotide, vanadate and ouabain binding, and K-pNPPase activity is close to m(alpha) = 112 kDa; for Na-ATPase activity it is 135 kDa and for Na,K-ATPase activity it increases from 140 to about 195 kDa with increasing assay ATP concentration (equal to increasing average turnover). Normal Tl+ occlusion had the same radiation inactivation size as Vmax for Na,K-ATPase, i.e. about 195 kDa. The binding experiments disclosed radiation-produced molecules with active binding sites but with a lower than normal affinity. Radiation inactivation size for the total binding capacity of ADP and ouabain was therefore smaller than the size of an alpha-peptide, namely about 70 kDa, and for total Tl+ occlusion it was down to 40 kDa. We can explain all these observations by using a new approach to target size analysis and by assuming a dimeric organization of the alpha-subunit. Each alpha-peptide is degraded stepwise by first destruction of either a 42- or a 70-kDa domain, and the partly damaged peptide may retain biochemical activity. We conclude that there is no role for the beta-subunit in catalysis and that the alpha-peptide is organized as an alpha 2-dimer in the membrane with each alpha-subunit being able to perform complete catalytic cycles (and probably also active transport), provided that it is stabilized by an adjacent alpha-peptide or a sufficiently large fragment thereof.

  19. A model for the stepwise radiation inactivation of the alpha 2-dimer of Na,K-ATPase

    International Nuclear Information System (INIS)

    Norby, J.G.; Jensen, J.

    1989-01-01

    This study is a direct continuation of Jensen, J., and Norby. A new model in which we propose that the in situ organization of the Na,K-ATPase alpha-subunit is an alpha 2-dimer and which describes the stepwise degradation by radiation inactivation of this assembly is presented on the basis of the following findings. Radiation inactivation size for alpha-peptide integrity, normal nucleotide, vanadate and ouabain binding, and K-pNPPase activity is close to m(alpha) = 112 kDa; for Na-ATPase activity it is 135 kDa and for Na,K-ATPase activity it increases from 140 to about 195 kDa with increasing assay ATP concentration (equal to increasing average turnover). Normal Tl+ occlusion had the same radiation inactivation size as Vmax for Na,K-ATPase, i.e. about 195 kDa. The binding experiments disclosed radiation-produced molecules with active binding sites but with a lower than normal affinity. Radiation inactivation size for the total binding capacity of ADP and ouabain was therefore smaller than the size of an alpha-peptide, namely about 70 kDa, and for total Tl+ occlusion it was down to 40 kDa. We can explain all these observations by using a new approach to target size analysis and by assuming a dimeric organization of the alpha-subunit. Each alpha-peptide is degraded stepwise by first destruction of either a 42- or a 70-kDa domain, and the partly damaged peptide may retain biochemical activity. We conclude that there is no role for the beta-subunit in catalysis and that the alpha-peptide is organized as an alpha 2-dimer in the membrane with each alpha-subunit being able to perform complete catalytic cycles (and probably also active transport), provided that it is stabilized by an adjacent alpha-peptide or a sufficiently large fragment thereof

  20. Initial sintering stage kinetics of CeO2 studied by stepwise isothermal dilatometry

    International Nuclear Information System (INIS)

    El Sayed Ali, M.; Toft Soerensen, O.

    1985-02-01

    The kinetics of the initial sintering stage of CeO 2 is studied by a new dilatometric technique in which the heating of the sample is controlled by its shrinkage rate. By this technique the shrinkage characteristically takes place in 'isothermal steps' which allows both the mechanism and its activation energy to be determined in a single experiment. The basic equations necessary to evaluate the shrinkage data are described, and using these equations on the curves recorded for CeO 2 it it shown that the controlling mechanism for the initial sintering stage for this oxides is grain-boundary diffusion of Ce 4+ -ions with an activation energy of 119.4 kcal/mole (5.2 eV). The corresponding diffusion coefficient is estimated to vary between 8.5 x 10 -17 - 3.1 x 10 -15 cm 2 /sec (1005 - 1099sup(o)C). (author)

  1. Evidence for stepwise dissociation dynamics in acetone at 248 and 193 nm

    Science.gov (United States)

    North, Simon W.; Blank, David A.; Gezelter, J. Daniel; Longfellow, Cheryl A.; Lee, Yuan T.

    1995-03-01

    The technique of molecular beam photofragment translational spectroscopy has been used to study the dissociation of acetone following S1←S0 (248 nm) and S2←S0 (193 nm) excitation. Excitation at 248 nm resulted in the production of CH3 and CH3CO with 14.2±1.0 kcal/mole on average of the available energy appearing as translation of the photofragments. Comparison of the measured with values reported at 266 nm suggest that the energy partitioning is dominated by the exit barrier caused by an avoided crossing on the potential energy surface. A substantial fraction (30±4%) of the nascent acetyl radicals from the primary dissociation contain sufficient energy to undergo spontaneous secondary decomposition. From the onset of the truncation of the CH3CO P(ET) a threshold of 17.8±3.0 kcal/mole for the dissociation of the acetyl radical has been determined in agreement with recent results on the photodissociation of acetyl chloride. The translational energy release in the dissociation of CH3CO closely matches the experimentally determined exit barrier. At 193 nm the only observed dissociation pathway was the formation of two methyl radicals and carbon monoxide. On average ˜38% of the available energy is found in product translation suggesting that significant internal energy resides in the nascent CH3 fragments consistent with the results of Hall et al. [J. Chem. Phys. 94, 4182 (1991)]. We conclude that the dynamics and energy partitioning for dissociation at 193 nm is similar to that at 248 nm.

  2. Paramedic-Initiated CMS Sepsis Core Measure Bundle Prior to Hospital Arrival: A Stepwise Approach.

    Science.gov (United States)

    Walchok, Jason G; Pirrallo, Ronald G; Furmanek, Douglas; Lutz, Martin; Shope, Colt; Giles, Brandi; Gue, Greta; Dix, Aaron

    2017-01-01

    To improve patient outcomes, the Center for Medicare and Medicaid Services (CMS) implemented core measures that outline the initial treatment of the septic patient. These measures include initial blood culture collection prior to antibiotics, adequate intravenous fluid resuscitation, and early administration of broad spectrum antibiotics. We sought to determine if Paramedics can initiate the CMS sepsis core measure bundle in the prehospital field reliably. This is a retrospective, case series from a 3rd service EMS system model in Greenville, South Carolina between November 17, 2014 and February 20, 2016. An adult Prehospital Sepsis Assessment Tool was created using the 2012 Surviving Sepsis guidelines: 2 of 3 signs of systemic inflammatory response (heart rate, respiratory rate, oral temperature) and a known or suspected source of infection. A "Sepsis Alert" was called by paramedics and upon IV access a set of blood cultures and blood for lactate analysis was collected prior to field antibiotic administration. The Sepsis Alert was compared to serum lactate levels and ICD 9 or 10 admitting diagnosis of Sepsis, Severe Sepsis, or Septic Shock. Blood culture contamination, serum lactate, and antibiotic match were determined by in-hospital laboratory analysis. A total of 120 trained paramedics called 1,185 "Sepsis Alerts" on 56,643 patients (50.3% Male, mean age 70). Patients with missing discharge diagnosis were eliminated (n = 31). The admitting diagnosis of sepsis overall was 73.5% (848/1154): Sepsis 50% (578/1154), Severe Sepsis 14.6% (169/1154), Septic Shock 8.9% (101/1154). A total of 946 blood cultures were collected in the prehospital setting, with a 95.04% (899/946) no contamination rate. Contamination was found in 4.96% (47/946). A total of 179 (18.9%) of the uncontaminated blood cultures were found to have positive growth with 720 (76.1%) having no growth. EMS administered antibiotics matched blood culture positive growth in 72% of patients. The lactate

  3. Piglets produced by transfer of vitrified porcine embryos after stepwise dilution of cryoprotectants.

    Science.gov (United States)

    Kobayashi, S; Takei, M; Kano, M; Tomita, M; Leibo, S P

    1998-02-01

    A total of 498 porcine embryos at various stages of development collected from superovulated gilts was used to investigate cryopreservation. First, blastocysts (BL), expanded blastocysts (ExB), and hatched blastocysts (HB) were used to determine the effect of exposure to concentrated solutions of ethylene glycol as cryoprotective additives (CPAs) on embryo survival. Then, survival of other embryos after vitrification by rapid cooling was determined. Based on their development after 48 h in culture, embryos were not injured by being exposed to 2.0 M ethylene glycol (EG) for 15 min or to 2.0 M EG for 5 min and then to a solution of 8.0 M EG in 7% polyvinylpyrrolidone (PVP) for 1 min. The CPAs were removed from the embryos by diluting them with 1.7 M galactose. To vitrify the embryos, they were exposed to 2.0 M EG for 5 min and then were pipetted directly into short columns of 8.0 M EG-PVP contained within (1.25-ml plastic straws and separated from long columns of 1.7 M galactose by an air bubble. The straws were plunged directly into LN2. After the straws were warmed rapidly in a 25 degrees C water bath, the embryos were immediately mixed with galactose within the straws by shaking them vigorously to mix the contents. In sequential experiments, three methods were used to dilute the CPA solutions. Method 1: Embryos in the EG-PVP-galactose mixture were expelled from the straws and rinsed and cultured in modified CZB medium (mCZB). Method II: Embryos in the mixture were placed briefly into 1.5 M EG and then rinsed and cultured in mCZB. Method III: Embryos in the mixture were rinsed in 1.0 M EG and then in 0.5 M EG and finally rinsed with mCZB and cultured. After 48 h in culture, the respective percentages of survival of embryos vitrified as BL, ExB, or HB were: Method I, 21, 32, and 13%; Method II, 9, 40, and 24%; Method III, 35, 85, and 71%. Of 20 additional ExB vitrified embryos diluted by Method III and transferred into a recipient, four developed into live piglets

  4. Decreasing Histology Turnaround Time Through Stepwise Innovation and Capacity Building in Rwanda

    Directory of Open Access Journals (Sweden)

    Gaspard Muvugabigwi

    2017-11-01

    Full Text Available Purpose: Minimal turnaround time for pathology results is crucial for highest-quality patient care in all settings, especially in low- and middle-income countries, where rural populations may have limited access to health care. Methods: We retrospectively determined the turnaround times (TATs for anatomic pathology specimens, comparing three different modes of operation that occurred throughout the development and implementation of our pathology laboratory at the Butaro Cancer Center of Excellence in Rwanda. Before opening this laboratory, TAT was measured in months because of inconsistent laboratory operations and a paucity of in-country pathologists. Results: We analyzed 2,514 individual patient samples across the three modes of study. Diagnostic mode 1 (samples sent out of the country for analysis had the highest median TAT, with an overall time of 30 days (interquartile range [IQR], 22 to 43 days. For diagnostic mode 2 (static image telepathology, the median TAT was 14 days (IQR, 7 to 27 days, and for diagnostic mode 3 (onsite expert diagnosis, it was 5 days (IQR, 2 to 9 days. Conclusion: Our results demonstrate that telepathology is a significant improvement over external expert review and can greatly assist sites in improving their TATs until pathologists are on site.

  5. Effect of step-wise change of stress and temperature on primary creep of concrete

    International Nuclear Information System (INIS)

    Furumura, Fukujiro; Abe, Takeo; Shinohara, Yasuji; Kim, Wha-Jung.

    1991-01-01

    The success of analyzing the behavior of concrete structures at elevated temperature greatly depends on how accurately certain mechanical properties, especially stress-strain curves, creep and thermal expansion, can be determined within wide temperature range. The importance of creep in the design of reinforced and prestressed concrete structures has been more recognized with the advent of the use of concrete at elevated temperature. The creep strain of concrete is affected by stress, time and temperature. The creep law which can predict the creep behavior under varying stress and temperature by using the experimental results of creep strain under constant stress and temperature is indispensable for analyzing the behavior of reinforced concrete structures under varying temperature. Accordingly the main purpose of this study is to clarify the primary creep behavior of concrete under varying stress and temperature. The cylindrical specimens, the testing procedure, the test results and the modified strain hardening law are reported. By using the modified strain hardening law, the primary creep behavior of concrete can be estimated better. (K.I.)

  6. The development of gamma energy identify algorithm for compact radiation sensors using stepwise refinement technique

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyun Jun [Div. of Radiation Regulation, Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Ye Won; Kim, Hyun Duk; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Yi, Yun [Dept. of of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)

    2017-06-15

    A gamma energy identifying algorithm using spectral decomposition combined with smoothing method was suggested to confirm the existence of the artificial radio isotopes. The algorithm is composed by original pattern recognition method and smoothing method to enhance the performance to identify gamma energy of radiation sensors that have low energy resolution. The gamma energy identifying algorithm for the compact radiation sensor is a three-step of refinement process. Firstly, the magnitude set is calculated by the original spectral decomposition. Secondly, the magnitude of modeling error in the magnitude set is reduced by the smoothing method. Thirdly, the expected gamma energy is finally decided based on the enhanced magnitude set as a result of the spectral decomposition with the smoothing method. The algorithm was optimized for the designed radiation sensor composed of a CsI (Tl) scintillator and a silicon pin diode. The two performance parameters used to estimate the algorithm are the accuracy of expected gamma energy and the number of repeated calculations. The original gamma energy was accurately identified with the single energy of gamma radiation by adapting this modeling error reduction method. Also the average error decreased by half with the multi energies of gamma radiation in comparison to the original spectral decomposition. In addition, the number of repeated calculations also decreased by half even in low fluence conditions under 104 (/0.09 cm{sup 2} of the scintillator surface). Through the development of this algorithm, we have confirmed the possibility of developing a product that can identify artificial radionuclides nearby using inexpensive radiation sensors that are easy to use by the public. Therefore, it can contribute to reduce the anxiety of the public exposure by determining the presence of artificial radionuclides in the vicinity.

  7. In vivo imaging of stepwise vessel occlusion in cerebral photothrombosis of mice by 19F MRI.

    Directory of Open Access Journals (Sweden)

    Gesa Weise

    Full Text Available (19F magnetic resonance imaging (MRI was recently introduced as a promising technique for in vivo cell tracking. In the present study we compared (19F MRI with iron-enhanced MRI in mice with photothrombosis (PT at 7 Tesla. PT represents a model of focal cerebral ischemia exhibiting acute vessel occlusion and delayed neuroinflammation.Perfluorocarbons (PFC or superparamagnetic iron oxide particles (SPIO were injected intravenously at different time points after photothrombotic infarction. While administration of PFC directly after PT induction led to a strong (19F signal throughout the entire lesion, two hours delayed application resulted in a rim-like (19F signal at the outer edge of the lesion. These findings closely resembled the distribution of signal loss on T2-weighted MRI seen after SPIO injection reflecting intravascular accumulation of iron particles trapped in vessel thrombi as confirmed histologically. By sequential administration of two chemically shifted PFC compounds 0 and 2 hours after illumination the different spatial distribution of the (19F markers (infarct core/rim could be visualized in the same animal. When PFC were applied at day 6 the fluorine marker was only detected after long acquisition times ex vivo. SPIO-enhanced MRI showed slight signal loss in vivo which was much more prominent ex vivo indicative for neuroinflammation at this late lesion stage.Our study shows that vessel occlusion can be followed in vivo by (19F and SPIO-enhanced high-field MRI while in vivo imaging of neuroinflammation remains challenging. The timing of contrast agent application was the major determinant of the underlying processes depicted by both imaging techniques. Importantly, sequential application of different PFC compounds allowed depiction of ongoing vessel occlusion from the core to the margin of the ischemic lesions in a single MRI measurement.

  8. FT-IR study and solvent-implicit and explicit effect on stepwise tautomerism of Guanylurea: M06-2X as a case of study.

    Science.gov (United States)

    Karimzadeh, Morteza; Manouchehri, Neda; Saberi, Dariush; Niknam, Khodabakhsh

    2018-06-15

    All 66 conformers of guanylurea were optimized and frequency calculations were performed at M06-2X/6-311++G(d,p) level of theory. Theses conformers were categorized into five tautomers, and the most stable conformer of each tautomer were found. Geometrical parameters indicated that these tautomers have almost planar structure. Complete stepwise tautomerism were studied through both intramolecular proton transfer routs and internal rotations. Results indicated that the proton transfer routs involving four-membered heterocyclic structures were rate-determining steps. Also, intramolecular proton movement having six-membered transition state structures had very low energy barrier comparable to the transition states of internal rotation routs. Differentiation of studied tautomers could easily be done through their FT-IR spectra in the range of 3200 to 3900cm -1 by comparing absorption bands and intensity of peaks. Solvent-implicit effects on the stability of tautomers were also studied through re-optimization and frequency calculation in four solvents. Water, DMSO, acetone and toluene had stabilization effect on all considered tautomers, but the order of stabilization effect was as follows: water>DMSO>acetone>toluene. Finally, solvent-explicit, base-explicit and acid-explicit effect were also studied by taking place of studied tautomer nearside of acid, base or solvent and optimization of them. Frequency calculation for proton movement by contribution of explicit effect showed that formic acid had a very strong effect on proton transfer from tautomer A1 to tautomer D8 by lowering the energy barrier from 42.57 to 0.8kcal/mol. In addition, ammonia-explicit effect was found to lower the barrier from 42.57 to 22.46kcal/mol, but this effect is lower than that of water and methanol-explicit effect. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. FT-IR study and solvent-implicit and explicit effect on stepwise tautomerism of Guanylurea: M06-2X as a case of study

    Science.gov (United States)

    Karimzadeh, Morteza; Manouchehri, Neda; Saberi, Dariush; Niknam, Khodabakhsh

    2018-06-01

    All 66 conformers of guanylurea were optimized and frequency calculations were performed at M06-2X/6-311++G(d,p) level of theory. Theses conformers were categorized into five tautomers, and the most stable conformer of each tautomer were found. Geometrical parameters indicated that these tautomers have almost planar structure. Complete stepwise tautomerism were studied through both intramolecular proton transfer routs and internal rotations. Results indicated that the proton transfer routs involving four-membered heterocyclic structures were rate-determining steps. Also, intramolecular proton movement having six-membered transition state structures had very low energy barrier comparable to the transition states of internal rotation routs. Differentiation of studied tautomers could easily be done through their FT-IR spectra in the range of 3200 to 3900 cm-1 by comparing absorption bands and intensity of peaks. Solvent-implicit effects on the stability of tautomers were also studied through re-optimization and frequency calculation in four solvents. Water, DMSO, acetone and toluene had stabilization effect on all considered tautomers, but the order of stabilization effect was as follows: water > DMSO > acetone > toluene. Finally, solvent-explicit, base-explicit and acid-explicit effect were also studied by taking place of studied tautomer nearside of acid, base or solvent and optimization of them. Frequency calculation for proton movement by contribution of explicit effect showed that formic acid had a very strong effect on proton transfer from tautomer A1 to tautomer D8 by lowering the energy barrier from 42.57 to 0.8 kcal/mol. In addition, ammonia-explicit effect was found to lower the barrier from 42.57 to 22.46 kcal/mol, but this effect is lower than that of water and methanol-explicit effect.

  10. The stepwise discriminant algorithm for snow cover mapping based on FY-3/MERSI data

    Science.gov (United States)

    Han, Tao; Wang, Dawei; Jiang, Youyan; Wang, Xiaowei

    2013-10-01

    Medium Resolution Spectral Imager (MERSI) on board China's new generation polar orbit meteorological satellite FY- 3A provides a new data source for snow monitoring in large area. As a case study, the typical snow cover of Qilian Mountains in northwest China was selected in this paper to develop the algorithm to map snow cover using FY- 3A/MERSI. By analyzing the spectral response characteristics of snow and other surface elements, as well as each channel image quality on FY-3A/MERSI, the widely used Normalized Difference Snow Index (NDSI) was defined to be computed from channel 2 and channel 7 for this satellite data. Basing on NDSI, a tree-structure prototype version of snow identification model was proposed, including five newly-built multi-spectral indexes to remove those pixels such as forest, cloud shadow, water, lake ice, sand (salty land), or cloud that are usually confused with snow step by step, especially, a snow/cloud discrimination index was proposed to eliminate cloud, apart from use of cloud mask product in advance. Furthermore, land cover land use (LULC) image has been adopted as auxiliary dataset to adjust the corresponding LULC NDSI threshold constraints for snow final determination and optimization. This model is composed as the core of FY-3A/MERSI snow cover mapping flowchart, to produce daily snow map at 250m spatial resolution, and statistics can be generated on the extent and persistence of snow cover in each pixel for time series maps. Preliminary validation activities of our snow identification model have been undertaken. Comparisons of the 104 FY- 3A/MERSI snow cover maps in 2010-2011 snow season with snow depth records from 16 meteorological stations in Qilian Mountains region, the sunny snow cover had an absolute accuracy of 92.8%. Results of the comparison with the snow cover identified from 6 Terra/MODIS scenes showed that they had consistent pixels about 85%. When the two satellite resultant snow cover maps compared with the 6

  11. A Proficiency Based Stepwise Endovascular Curricular Training (PROSPECT) Program Enhances Operative Performance in Real Life: A Randomised Controlled Trial.

    Science.gov (United States)

    Maertens, H; Aggarwal, R; Moreels, N; Vermassen, F; Van Herzeele, I

    2017-09-01

    Healthcare evolution requires optimisation of surgical training to provide safe patient care. Operating room performance after completion of proficiency based training in vascular surgery has not been investigated. A randomised controlled trial evaluated the impact of a Proficiency based Stepwise Endovascular Curricular Training program (PROSPECT) on the acquisition of endovascular skills and the transferability of these skills to real life interventions. All subjects performed two endovascular interventions treating patients with symptomatic iliac and/or superficial femoral artery stenosis under supervision. Primary outcomes were technical performances (Global Rating Scale [GRS]; Examiner Checklist), operative metrics, and patient outcomes, adjusted for case difficulty and trainee experience. Secondary outcomes included knowledge and technical performance after 6 weeks and 3 months. Thirty-two general surgical trainees were randomised into three groups. Besides traditional training, the first group (n = 11) received e-learning and simulation training (PROSPECT), the second group (n = 10) only had access to e-learning, while controls (n = 11) did not receive supplementary training. Twenty-nine trainees (3 dropouts) performed 58 procedures. Trainees who completed PROSPECT showed superior technical performance (GRS 39.36 ± 2.05; Checklist 63.51 ± 3.18) in real life with significantly fewer supervisor takeovers compared with trainees receiving e-learning alone (GRS 28.42 ± 2.15; p = .001; Checklist 53.63 ± 3.34; p = .027) or traditional education (GRS 23.09 ± 2.18; p = .001; Checklist 38.72 ± 3.38; p = .001). Supervisors felt more confident in allowing PROSPECT trained physicians to perform basic (p = .006) and complex (p = .003) procedures. No differences were detected in procedural parameters (such as fluoroscopy time, DAP, procedure time, etc.) or complications. Proficiency levels were maintained up to 3 months. A structured

  12. Effects on pain of a stepwise multidisciplinary intervention (STA OP!) that targets pain and behavior in advanced dementia: A cluster randomized controlled trial

    NARCIS (Netherlands)

    Pieper, Marjoleine J.C.; van der Steen, Jenny T.; Francke, Anneke L.; Scherder, Erik J.A.; Twisk, Jos W.R.; Achterberg, Wilco P.

    Background: Pain in nursing home residents with advanced dementia remains a major challenge; it is difficult to detect and may be expressed as challenging behavior. STA OP! aims to identify physical and other needs as causes of behavioral changes and uses a stepwise approach for psychosocial and

  13. Effects on pain of a stepwise multidisciplinary intervention (STA OP!) that targets pain and behavior in advanced dementia: A cluster randomized controlled trial.

    NARCIS (Netherlands)

    Pieper, M.J.C.; Steen, J.T. van der; Francke, A.L.; Scherder, E.J.A.; Twisk, J.W.R.; Achterberg, W.P.

    2018-01-01

    Background: Pain in nursing home residents with advanced dementia remains a major challenge; it is difficult to detect and may be expressed as challenging behavior. STA OP! aims to identify physical and other needs as causes of behavioral changes and uses a stepwise approach for psychosocial and

  14. Stepwise circumferential and focal ablation of Barrett's esophagus with high-grade dysplasia: results of the first prospective series of 11 patients

    NARCIS (Netherlands)

    Gondrie, J. J.; Pouw, R. E.; Sondermeijer, C. M. T.; Peters, F. P.; Curvers, W. L.; Rosmolen, W. D.; Krishnadath, K. K.; ten Kate, F.; Fockens, P.; Bergman, J. J.

    2008-01-01

    BACKGROUND AND STUDY AIMS: Stepwise circumferential and focal ablation of nondysplastic Barrett's esophagus has proven safe and effective. This study assessed the efficacy and safety of ablation for Barrett's esophagus with high-grade dysplasia (HGD), and residual Barrett's esophagus with dysplasia

  15. Treatment of deep caries lesions in adults: randomized clinical trials comparing stepwise vs. direct complete excavation, and direct pulp capping vs. partial pulpotomy

    DEFF Research Database (Denmark)

    Bjørndal, Lars; Reit, Claes; Bruun, Gitte Hoffmann

    2010-01-01

    Less invasive excavation methods have been suggested for deep caries lesions. We tested the effects of stepwise vs. direct complete excavation, 1 yr after the procedure had been carried out, in 314 adults (from six centres) who had received treatment of a tooth with deep caries. The teeth had car...

  16. Simultaneous enhancement of phenolic compound degradations by Acinetobacter strain V2 via a step-wise continuous acclimation process.

    Science.gov (United States)

    Lin, Johnson; Sharma, Vikas; Milase, Ridwaan; Mbhense, Ntuthuko

    2016-06-01

    Phenol degradation enhancement of Acinetobacter strain V2 by a step-wise continuous acclimation process was investigated. At the end of 8 months, three stable adapted strains, designated as R, G, and Y, were developed with the sub-lethal concentration of phenol at 800, 1100, and 1400 mg/L, respectively, from 400 mg/L of V2 parent strain. All strains degraded phenol at their sub-lethal level within 24 h, their growth rate increased as the acclimation process continued and retained their degradation properties even after storing at -80 °C for more than 3 years. All adapted strains appeared coccoid with an ungranulated surface under electron microscope compared to typical rod-shaped parental strain V2 . The adapted Y strain also possessed superior degradation ability against aniline, benzoate, and toluene. This study demonstrated the use of long term acclimation process to develop efficient and better pollutant degrading bacterial strains with potentials in industrial and environmental bioremediation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Super-hierarchical porous carbons derived from mixed biomass wastes by a stepwise removal strategy for high-performance supercapacitors

    Science.gov (United States)

    Peng, Lin; Liang, Yeru; Dong, Hanwu; Hu, Hang; Zhao, Xiao; Cai, Yijing; Xiao, Yong; Liu, Yingliang; Zheng, Mingtao

    2018-02-01

    The synthesis and energy storage application of hierarchical porous carbons with size ranging from nano-to micrometres has attracted considerable attention all over the world. Exploring eco-friendly and reliable synthesis of hierarchical porous carbons for supercapacitors with high energy density and high power is still of ongoing challenge. In this work, we report the design and synthesis of super-hierarchical porous carbons with highly developed porosity by a stepwise removal strategy for high-rate supercapacitors. The mixed biomass wastes of coconut shell and sewage sludge are employed as raw material. The as-prepared super-hierarchical porous carbons present high surface areas (3003 m2 g-1), large pore volume (2.04 cm3 g-1), appropriate porosity, and outstanding electrochemical performance. The dependence of electrochemical performance on structural, textural, and functional properties of carbons engineered by various synthesis strategies is investigated in detail. Moreover, the as-assembled symmetrical supercapacitor exhibits high energy density of 25.4 Wh kg-1 at a power density of 225 W kg-1 and retains 20.7 Wh kg-1 even at a very high power of 9000 W kg-1. This work provides an environmentally benign strategy and new insights to efficiently regulate the porosity of hierarchical porous carbons derived from biomass wastes for energy storage applications.

  18. Stepwise integral scaling method for severe accident analysis and its application to corium dispersion in direct containment heating

    International Nuclear Information System (INIS)

    Ishii, M.; Zhang, G.; No, H. C.; Eltwila, F.

    1994-01-01

    Accident sequences which lead to severe core damage and to possible radioactive fission products into the environment have a very low probability. However, the interest in this area increased significantly due to the occurrence of the small break loss-of-coolant accident at TMI-2 which led to partial core damage, and of the Chernobyl accident in the former USSR which led to extensive core disassembly and significant release of fission products over several countries. In particular, the latter accident raised the international concern over the potential consequences of severe accidents in nuclear reactor systems. One of the significant shortcomings in the analyses of severe accidents is the lack of well-established and reliable scaling criteria for various multiphase flow phenomena. However, the scaling criteria are essential to the severe accident, because the full scale tests are basically impossible to perform. They are required for (1) designing scaled down or simulation experiments, (2) evaluating data and extrapolating the data to prototypic conditions, and (3) developing correctly scaled physical models and correlations. In view of this, a new scaling method is developed for the analysis of severe accidents. Its approach is quite different from the conventional methods. In order to demonstrate its applicability, this new stepwise integral scaling method has been applied to the analysis of the corium dispersion problem in the direct containment heating. ((orig.))

  19. Microtubule Protofilament Number Is Modulated in a Step-Wise Fashion By the Charge of Density of An Enveloping Layer

    International Nuclear Information System (INIS)

    Raviv, U.; Nguyen, T.; Ghafouri, R.; Needleman, D.J.; Li, Y.; Miller, H.P.; Wilson, L.; Bruinsma, R.F.; Safinya, C.R.; UC, Santa Barbara; UCLA

    2007-01-01

    Microtubules are able to adjust their protofilament (PF) number and, as a consequence, their dynamics and function, to the assembly conditions and presence of cofactors. However, the principle behind such variations is poorly understood. Using synchrotron x-ray scattering and transmission electron microscopy, we studied how charged membranes, which under certain conditions can envelop preassembled MTs, regulate the PF number of those MTs. We show that the mean PF number, , is modulated primarily by the charge density of the membranes. decreases in a stepwise fashion with increasing membrane charge density. does not depend on the membrane-protein stoichiometry or the solution ionic strength. We studied the effect of taxol and found that increases logarithmically with taxol/tubulin stoichiometry. We present a theoretical model, which by balancing the electrostatic and elastic interactions in the system accounts for the trends in our findings and reveals an effective MT bending stiffness of order 10-100 k B T/nm, associated with the observed changes in PF number

  20. High-quality fuel from food waste - investigation of a stepwise process from the perspective of technology development.

    Science.gov (United States)

    Yin, Ke; Li, Ling; Giannis, Apostolos; Weerachanchai, Piyarat; Ng, Bernard J H; Wang, Jing-Yuan

    2017-07-01

    A stepwise process (SP) was developed for sustainable energy production from food waste (FW). The process comprised of hydrothermal treatment followed by oil upgrading. Synthetic food waste was primarily used as feedstock in the hydrothermal reactor under subcritical water conditions. The produced hydrochars were analyzed for calorific value (17.0-33.7 MJ/kg) and elemental composition indicating high-quality fuel comparable to coal. Hydrothermal carbonization (e.g. 180°C) would be efficient for oil recovery (>90%) from FW, as compared to hydrothermal liquefaction (320°C) whereby lipid degradation may take place. The recovered oil was upgraded to biodiesel in a catalytic refinery process. Selected biodiesels, that is, B3 and B4 were characterized for density (872.7 and 895.5 kg/m 3 ), kinematic viscosity (3.115 and 8.243 cSt), flash and pour point (30°C and >126°C), micro carbon (0.03% and 0.04%), sulfur (both biofuel and hydrochar production.

  1. A Population Biology Perspective on the Stepwise Infection Process of the Bacterial Pathogen Pasteuria ramosa in Daphnia.

    Science.gov (United States)

    Ebert, Dieter; Duneau, David; Hall, Matthew D; Luijckx, Pepijn; Andras, Jason P; Du Pasquier, Louis; Ben-Ami, Frida

    2016-01-01

    The infection process of many diseases can be divided into series of steps, each one required to successfully complete the parasite's life and transmission cycle. This approach often reveals that the complex phenomenon of infection is composed of a series of more simple mechanisms. Here we demonstrate that a population biology approach, which takes into consideration the natural genetic and environmental variation at each step, can greatly aid our understanding of the evolutionary processes shaping disease traits. We focus in this review on the biology of the bacterial parasite Pasteuria ramosa and its aquatic crustacean host Daphnia, a model system for the evolutionary ecology of infectious disease. Our analysis reveals tremendous differences in the degree to which the environment, host genetics, parasite genetics and their interactions contribute to the expression of disease traits at each of seven different steps. This allows us to predict which steps may respond most readily to selection and which steps are evolutionarily constrained by an absence of variation. We show that the ability of Pasteuria to attach to the host's cuticle (attachment step) stands out as being strongly influenced by the interaction of host and parasite genotypes, but not by environmental factors, making it the prime candidate for coevolutionary interactions. Furthermore, the stepwise approach helps us understanding the evolution of resistance, virulence and host ranges. The population biological approach introduced here is a versatile tool that can be easily transferred to other systems of infectious disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Computations on the primary photoreaction of Br2 with CO2: stepwise vs concerted addition of Br atoms.

    Science.gov (United States)

    Xu, Kewei; Korter, Timothy M; Braiman, Mark S

    2015-04-09

    It was proposed previously that Br2-sensitized photolysis of liquid CO2 proceeds through a metastable primary photoproduct, CO2Br2. Possible mechanisms for such a photoreaction are explored here computationally. First, it is shown that the CO2Br radical is not stable in any geometry. This rules out a free-radical mechanism, for example, photochemical splitting of Br2 followed by stepwise addition of Br atoms to CO2-which in turn accounts for the lack of previously observed Br2+CO2 photochemistry in gas phases. A possible alternative mechanism in liquid phase is formation of a weakly bound CO2:Br2 complex, followed by concerted photoaddition of Br2. This hypothesis is suggested by the previously published spectroscopic detection of a binary CO2:Br2 complex in the supersonically cooled gas phase. We compute a global binding-energy minimum of -6.2 kJ mol(-1) for such complexes, in a linear geometry. Two additional local minima were computed for perpendicular (C2v) and nearly parallel asymmetric planar geometries, both with binding energies near -5.4 kJ mol(-1). In these two latter geometries, C-Br and O-Br bond distances are simultaneously in the range of 3.5-3.8 Å, that is, perhaps suitable for a concerted photoaddition under the temperature and pressure conditions where Br2 + CO2 photochemistry has been observed.

  3. A Stepwise "Micellization-Crystallization" Route to Oblate Ellipsoidal, Cylindrical, and Bilayer Micelles with Polyethylene Cores in Water

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ligeng; Lodge, Timothy P; Hillmyer, Marc A [UMM

    2012-11-26

    Micellar polymorphism from block copolymers has been well documented, but most attention has focused on noncrystalline hydrophobic systems. We have investigated the micellization in water of model diblock copolymers with semicrystalline polyethylene (PE) as the core-forming component. Poly(N,N-dimethylacrylamide)–polyethylene (AE) diblock copolymers were synthesized by a combination of anionic and RAFT polymerizations. The bulk nanostructures were probed by small-angle X-ray scattering (SAXS) and AE diblock copolymers were found to be moderately segregated at 140 °C. Dispersions of AE amphiphiles in water were prepared by direct dissolution at 120 °C (i.e., above the melting transition of PE) followed by cooling to 25 °C. By manipulating the composition of AE diblock copolymers, discrete structures with oblate ellipsoidal, cylindrical, and bilayer morphologies were produced, as evidenced in cryogenic transmission electron microscopy (cryo-TEM). The self-assembled aggregates were also studied by small-angle neutron scattering (SANS) and dilute solution rheology. The semicrystalline nature of the nanostructures was further revealed by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS). A stepwise “micellization–crystallization” process was proposed as the micelle formation mechanism, as supported by the existence of similar nanostructures at 120 °C using SANS. This strategy holds promise for a general protocol toward the production of giant wormlike micelles and vesicles with semicrystalline polymeric cores.

  4. The World Health Organization STEPwise Approach to Noncommunicable Disease Risk-Factor Surveillance: Methods, Challenges, and Opportunities.

    Science.gov (United States)

    Riley, Leanne; Guthold, Regina; Cowan, Melanie; Savin, Stefan; Bhatti, Lubna; Armstrong, Timothy; Bonita, Ruth

    2016-01-01

    We sought to outline the framework and methods used by the World Health Organization (WHO) STEPwise approach to noncommunicable disease (NCD) surveillance (STEPS), describe the development and current status, and discuss strengths, limitations, and future directions of STEPS surveillance. STEPS is a WHO-developed, standardized but flexible framework for countries to monitor the main NCD risk factors through questionnaire assessment and physical and biochemical measurements. It is coordinated by national authorities of the implementing country. The STEPS surveys are generally household-based and interviewer-administered, with scientifically selected samples of around 5000 participants. To date, 122 countries across all 6 WHO regions have completed data collection for STEPS or STEPS-aligned surveys. STEPS data are being used to inform NCD policies and track risk-factor trends. Future priorities include strengthening these linkages from data to action on NCDs at the country level, and continuing to develop STEPS' capacities to enable a regular and continuous cycle of risk-factor surveillance worldwide.

  5. Stepwise swelling of a thin film of lamellae-forming poly(styrene-b- butadiene) in cyclohexane vapor

    KAUST Repository

    Di, Zhenyu; Posselt, Dorthe; Smilgies, Detlef Matthias; Li, Ruipeng; Rauscher, Markus; Potemkin, Igor I.; Papadakis, Christine M.

    2012-01-01

    We investigated the swelling of a thin film of lamellae-forming poly(styrene-b-butadiene) in cyclohexane vapor. The vapor pressure and thus the degree of swelling of the film are increased in a stepwise manner using a custom-built sample cell. The resulting structural changes during and after each step were followed in situ using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). During the first step, the lamellar thickness increases strongly, before it decreases again. At the same time, the full width at half-maximum (FWHM) of the diffuse Bragg reflection along the film normal has a sharp maximum. These observations point to the formation of new lamellae. During the subsequent swelling steps, the lamellar thickness overshoots only weakly. The behavior thus resembles qualitatively our previous results on a similar thin film during swelling in saturated vapor of cyclohexane; however, it deviates from earlier theoretical predictions. We propose a theory that is quantitatively correct for the description of the dependence of the lamellar thickness on the polymer volume fraction in the late stage of the swelling steps. © 2012 American Chemical Society.

  6. Impact of stepwise ablation on the biatrial substrate in patients with persistent atrial fibrillation and heart failure.

    Science.gov (United States)

    Jones, David G; Haldar, Shouvik K; Jarman, Julian W E; Johar, Sofian; Hussain, Wajid; Markides, Vias; Wong, Tom

    2013-08-01

    Ablation of persistent atrial fibrillation can be challenging, often involving not only pulmonary vein isolation (PVI) but also additional linear lesions and ablation of complex fractionated electrograms (CFE). We examined the impact of stepwise ablation on a human model of advanced atrial substrate of persistent atrial fibrillation in heart failure. In 30 patients with persistent atrial fibrillation and left ventricular ejection fraction ≤35%, high-density CFE maps were recorded biatrially at baseline, in the left atrium (LA) after PVI and linear lesions (roof and mitral isthmus), and biatrially after LA CFE ablation. Surface area of CFE (mean cycle length ≤120 ms) remote to PVI and linear lesions, defined as CFE area, was reduced after PVI (18.3±12.03 to 10.2±7.1 cm(2); Patrial CFE area was reduced by LA ablation, from 25.9±14.1 to 12.9±11.8 cm(2) (Patrial CFE area. Reduction of CFE area at sites remote from ablation would suggest either regression of the advanced atrial substrate or that these CFE were functional phenomena. Nevertheless, in an advanced atrial fibrillation substrate, linear lesions after PVI diminished the target area for CFE ablation, and complete lesions resulted in a favorable clinical outcome.

  7. Gradual and stepwise pyrolyses of insoluble organic matter from the Murchison meteorite revealing chemical structure and isotopic distribution

    Science.gov (United States)

    Okumura, Fumiaki; Mimura, Koichi

    2011-11-01

    To study the detailed structural and isotopic heterogeneity of the insoluble organic matter (IOM) of the Murchison meteorite, we performed two types of pyrolytic experiments: gradual pyrolysis and stepwise pyrolysis. The pyrolysates from the IOM contained 5 specific organic groups: aliphatic hydrocarbons, aromatic hydrocarbons, sulfur-bearing compounds, nitrogen-bearing compounds, and oxygen-bearing compounds. The release temperatures and the compositions of these pyrolysates demonstrated that the IOM is composed of a thermally unstable part and a thermally stable part. The thermally unstable part mainly served as the linkage and substituent portion that bound the thermally stable part, which was dispersed throughout the IOM. The linkage and substituent portion consisted of aliphatic hydrocarbons from C 4 to C 8, aromatic hydrocarbons with up to 6 rings, sulfo and thiol groups (the main reservoirs of sulfur in the IOM), and carboxyl and hydroxyl groups (the main reservoirs of oxygen). However, the thermally stable part was composed of polycyclic aromatic hydrocarbons (PAHs) containing nitrogen heterocycles in the IOM. Isotopic data showed that the aliphatic and aromatic hydrocarbons in the linkage and substituent portion were rich in D and 13C, while the thermally stable part was deficient in D and 13C. The structural and isotopic features suggested that the IOM was formed by mixing sulfur- and oxygen-bearing compounds rich in D and 13C (e.g., polar compounds in the interstellar medium (ISM)) and nitrogen-bearing PAHs deficient in D and 13C (e.g., polymerized compounds in the ISM).

  8. Relationships between each part of the spinal curves and upright posture using Multiple stepwise linear regression analysis.

    Science.gov (United States)

    Boulet, Sebastien; Boudot, Elsa; Houel, Nicolas

    2016-05-03

    Back pain is a common reason for consultation in primary healthcare clinical practice, and has effects on daily activities and posture. Relationships between the whole spine and upright posture, however, remain unknown. The aim of this study was to identify the relationship between each spinal curve and centre of pressure position as well as velocity for healthy subjects. Twenty-one male subjects performed quiet stance in natural position. Each upright posture was then recorded using an optoelectronics system (Vicon Nexus) synchronized with two force plates. At each moment, polynomial interpolations of markers attached on the spine segment were used to compute cervical lordosis, thoracic kyphosis and lumbar lordosis angle curves. Mean of centre of pressure position and velocity was then computed. Multiple stepwise linear regression analysis showed that the position and velocity of centre of pressure associated with each part of the spinal curves were defined as best predictors of the lumbar lordosis angle (R(2)=0.45; p=1.65*10-10) and the thoracic kyphosis angle (R(2)=0.54; p=4.89*10-13) of healthy subjects in quiet stance. This study showed the relationships between each of cervical, thoracic, lumbar curvatures, and centre of pressure's fluctuation during free quiet standing using non-invasive full spinal curve exploration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Protein homology network families reveal step-wise diversification of Type III and Type IV secretion systems.

    Directory of Open Access Journals (Sweden)

    Duccio Medini

    2006-12-01

    Full Text Available From the analysis of 251 prokaryotic genomes stored in public databases, the 761,260 deduced proteins were used to reconstruct a complete set of bacterial proteic families. Using the new Overlap algorithm, we have partitioned the Protein Homology Network (PHN, where the proteins are the nodes and the links represent homology relationships. The algorithm identifies the densely connected regions of the PHN that define the families of homologous proteins, here called PHN-Families, recognizing the phylogenetic relationships embedded in the network. By direct comparison with a manually curated dataset, we assessed that this classification algorithm generates data of quality similar to a human expert. Then, we explored the network to identify families involved in the assembly of Type III and Type IV secretion systems (T3SS and T4SS. We noticed that, beside a core of conserved functions (eight proteins for T3SS, seven for T4SS, a variable set of accessory components is always present (one to nine for T3SS, one to five for T4SS. Each member of the core corresponds to a single PHN-Family, while accessory proteins are distributed among different pure families. The PHN-Family classification suggests that T3SS and T4SS have been assembled through a step-wise, discontinuous process, by complementing the conserved core with subgroups of nonconserved proteins. Such genetic modules, independently recruited and probably tuned on specific effectors, contribute to the functional specialization of these organelles to different microenvironments.

  10. Stepwise swelling of a thin film of lamellae-forming poly(styrene-b- butadiene) in cyclohexane vapor

    KAUST Repository

    Di, Zhenyu

    2012-06-26

    We investigated the swelling of a thin film of lamellae-forming poly(styrene-b-butadiene) in cyclohexane vapor. The vapor pressure and thus the degree of swelling of the film are increased in a stepwise manner using a custom-built sample cell. The resulting structural changes during and after each step were followed in situ using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). During the first step, the lamellar thickness increases strongly, before it decreases again. At the same time, the full width at half-maximum (FWHM) of the diffuse Bragg reflection along the film normal has a sharp maximum. These observations point to the formation of new lamellae. During the subsequent swelling steps, the lamellar thickness overshoots only weakly. The behavior thus resembles qualitatively our previous results on a similar thin film during swelling in saturated vapor of cyclohexane; however, it deviates from earlier theoretical predictions. We propose a theory that is quantitatively correct for the description of the dependence of the lamellar thickness on the polymer volume fraction in the late stage of the swelling steps. © 2012 American Chemical Society.

  11. A scalable synthesis of 5,5'-dibromo-2,2'-bipyridine and its stepwise functionalization via Stille couplings.

    Science.gov (United States)

    D'Souza, Daniel M; Leigh, David A; Papmeyer, Marcus; Woltering, Steffen L

    2012-11-01

    The synthesis of 5,5'-dibromo-2,2'-bipyridine and 5-bromo-2,2'-bipyridine, useful intermediates for elaboration into more complex ligands through metal-catalyzed coupling reactions, can be efficiently conducted on a multigram scale from inexpensive starting materials. The described procedure is reliably scalable and suitable for the synthesis of tens of grams of 5,5'-dibromo-2,2'-bipyridine. 5-Bromo-2,2'-bipyridine is produced as a minor product. The 5,5'-disubstituted-2,2'-bipyridine motif has excellent coordination properties and is a versatile building block for the synthesis of functional materials (including biodiagnostics, photovoltaics and organic light-emitting diodes) and complex molecular topologies (including catenanes and trefoil and pentafoil knots). The selective stepwise functionalization of 5,5'-dibromo-2,2'-bipyridine by consecutive Stille couplings is therefore illustrated and documented in detail. The synthesis of 5,5'-dibromo-2,2'-bipyridine takes 4-5 d: 1 d to prepare the key intermediate 2,2'-bipyridine dihydrobromide, 3 d for its reaction with bromine in a steel bomb reaction vessel and 8 h to isolate and purify the final product.

  12. Size-Induced Segregation in the Stepwise Microhydration of Hydantoin and Its Role in Proton-Induced Charge Transfer

    Science.gov (United States)

    Calvo, Florent; Bacchus-Montabonel, Marie-Christine

    2018-01-01

    Recent photochemistry experiments provided evidence for the formation of hydantoin by irradiation of interstellar ice analogues. The significance of these results and the importance of hydantoin in prebiotic chemistry and polypeptide synthesis motivate the present theoretical investigation, in which we analyzed the effects of stepwise hydration on the electronic and thermodynamical properties of the structure of microhydrated hydantoin using a variety of computational approaches. We generally find microhydration to proceed around the hydantoin heterocycle until 5 water molecules are reached, at which stage hydration becomes segregated with a water cluster forming aside the heterocycle. The reactivity of microhydrated hydantoin caused by an impinging proton was evaluated through charge transfer collision cross sections for microhydrated compounds but also for hydantoin on icy grains modeled using a cluster approach mimicking the true hexagonal ice surface. The effects of hydration on charge transfer efficiency are mostly significant when few water molecules are present, and they progressively weaken and stabilize in larger clusters. On the ice substrate, charge transfer essentially contributes to a global increase in the cross sections.

  13. Stepwise DNA Methylation Changes Are Linked to Escape from Defined Proliferation Barriers and Mammary Epithelial Cell Immortalization

    Energy Technology Data Exchange (ETDEWEB)

    Novak, Petr; Jensen, Taylor J.; Garbe, James C.; Stampfer, Martha R.; Futscher, Bernard W.

    2009-04-20

    The timing and progression of DNA methylation changes during carcinogenesis are not completely understood. To develop a timeline of aberrant DNA methylation events during malignant transformation, we analyzed genome-wide DNA methylation patterns in an isogenic human mammary epithelial cell (HMEC) culture model of transformation. To acquire immortality and malignancy, the cultured finite lifespan HMEC must overcome two distinct proliferation barriers. The first barrier, stasis, is mediated by the retinoblastoma protein and can be overcome by loss of p16(INK4A) expression. HMEC that escape stasis and continue to proliferate become genomically unstable before encountering a second more stringent proliferation barrier, telomere dysfunction due to telomere attrition. Rare cells that acquire telomerase expression may escape this barrier, become immortal, and develop further malignant properties. Our analysis of HMEC transitioning from finite lifespan to malignantly transformed showed that aberrant DNA methylation changes occur in a stepwise fashion early in the transformation process. The first aberrant DNA methylation step coincides with overcoming stasis, and results in few to hundreds of changes, depending on how stasis was overcome. A second step coincides with immortalization and results in hundreds of additional DNA methylation changes regardless of the immortalization pathway. A majority of these DNA methylation changes are also found in malignant breast cancer cells. These results show that large-scale epigenetic remodeling occurs in the earliest steps of mammary carcinogenesis, temporally links DNA methylation changes and overcoming cellular proliferation barriers, and provides a bank of potential epigenetic biomarkers that mayprove useful in breast cancer risk assessment.

  14. Towards a short questionnaire for stepwise assessment of upper limb function, pain and stiffness in Duchenne muscular dystrophy.

    Science.gov (United States)

    Janssen, Mariska M H P; Geurts, Alexander C H; de Groot, Imelda J M

    2018-04-01

    Duchenne muscular dystrophy can lead to upper extremity limitations, pain and stiffness. In a previous study, these domains have been investigated using extensive questionnaires, which are too time-consuming for clinical practice. This study aimed at gaining insight into the underlying dimensions of these questionnaires, and to construct a short questionnaire that can be used for clinical assessment. Exploratory factor analysis was performed on the responses of 213 participants to a web-based survey to find the underlying dimensions in the Capabilities of Upper Extremity questionnaire, the ABILHAND questionnaire, and questionnaires regarding pain and stiffness. Based on these underlying dimensions, a stepwise approach was formulated. In addition, construct validity of the factors was investigated. In total, 14 factors were identified. All had high internal consistency (Cronbach's alpha >0.89) and explained 80-88% of the variance of the original questionnaires. Construct validity was supported, because participants in the early ambulatory stage performed significantly better (pDuchenne muscular dystrophy. Based on the factor commonalities, the Upper Limb Short Questionnaire was formulated. Implications for Rehabilitation New insights into the underlying dimensions of upper extremity function, pain and stiffness in Duchenne muscular dystrophy are gained. Fourteen factors, with good internal consistency and construct validity, are identified regarding upper extremity function, pain and stiffness in Duchenne muscular dystrophy. Based on these factors, the Upper Limb Short Questionnaire is presented. The Upper Limb Short Questionnaire can be used as an identifier of arm-hand limitations and the start of more thorough clinical investigation.

  15. The Stepwise Behavioral Responses: Behavioral Adjustment of the Chinese Rare Minnow (Gobiocypris rarus in the Exposure of Carbamate Pesticides

    Directory of Open Access Journals (Sweden)

    Zongming Ren

    2013-01-01

    Full Text Available In order to illustrate the behavioral regulation in environmental stress, the behavioral responses of the Chinese rare minnow (Gobiocypris rarus to arprocarb, carbofuran, and oxamyl were analyzed with an online monitoring system. The Self-Organizing Map (SOM was used to define the patterns of the behavioral data obtained from treatments at concentrations of 0.1 toxic unit (TU, 1 TU, 2 TU, 5 TU, 10 TU, and 20 TU and a control. In certain cases, differences among the carbamate pesticides (CPs tested were observed. The profiles of behavioral strength (BS in SOM varied according to the concentration used. The time of the first significant decrease of the BS varied inversely with the CP concentrations. The results suggested that the behavioral regulation in the stepwise behavioral responses (SBR was evident. The primary movement behaviors shown by the SBR model included no effect, stimulation, acclimation, adjustment (readjustment, and toxic effect, especially at the lower concentrations. However, higher stress (10 TU and 20 TU might limit the function of the behavioral adjustment produced by the intrinsic response mechanisms. It was concluded that SBR, which were affected by both the concentration and the exposure time, could be used as a suitable indicator in the ecotoxicological risk assessment of CPs.

  16. Stepwise hydrogeological modeling and groundwater flow analysis on site scale (The former part of the step 3)

    International Nuclear Information System (INIS)

    Onoe, Hironori; Saegusa, Hiromitsu; Endo, Yoshinobu

    2005-07-01

    One of the main goals of the Mizunami Underground Research Laboratory Project is to establish comprehensive techniques for investigation, analysis, and assessment of the deep geological environment. To achieve this goal, a variety of investigations are being conducted using an iterative approach. In this study, hydrogeological modeling and groundwater flow analyses have been carried out using the data from surface-based investigations at the former part of Step 3 (deep borehole investigations without vertical seismic profiling investigations), in order to synthesize the investigation results, to evaluate the uncertainty of the hydrogeological model, and to specify items for further investigation. The results of this study are summarized as follows: 1) The uncertainty of hydrogeological model of the site scale is decreased as stepwise research; 2) Borehole investigations combined with hydraulic monitoring are useful for decreasing the uncertainty of hydrogeological model; The main items specified for further investigations are summarized as follows: 1) Trend, length, and hydraulic parameters of faults confirmed in the MIU construction site; 2) Shape of boundary of geological layer, and hydraulic parameters of rock; 3) Hydraulic head distribution of deep underground. (author)

  17. Mobile Phone Apps to Improve Medication Adherence: A Systematic Stepwise Process to Identify High-Quality Apps.

    Science.gov (United States)

    Santo, Karla; Richtering, Sarah S; Chalmers, John; Thiagalingam, Aravinda; Chow, Clara K; Redfern, Julie

    2016-12-02

    There are a growing number of mobile phone apps available to support people in taking their medications and to improve medication adherence. However, little is known about how these apps differ in terms of features, quality, and effectiveness. We aimed to systematically review the medication reminder apps available in the Australian iTunes store and Google Play to assess their features and their quality in order to identify high-quality apps. This review was conducted in a similar manner to a systematic review by using a stepwise approach that included (1) a search strategy; (2) eligibility assessment; (3) app selection process through an initial screening of all retrieved apps and full app review of the included apps; (4) data extraction using a predefined set of features considered important or desirable in medication reminder apps; (5) analysis by classifying the apps as basic and advanced medication reminder apps and scoring and ranking them; and (6) a quality assessment by using the Mobile App Rating Scale (MARS), a reliable tool to assess mobile health apps. We identified 272 medication reminder apps, of which 152 were found only in Google Play, 87 only in iTunes, and 33 in both app stores. Apps found in Google Play had more customer reviews, higher star ratings, and lower cost compared with apps in iTunes. Only 109 apps were available for free and 124 were recently updated in 2015 or 2016. Overall, the median number of features per app was 3.0 (interquartile range 4.0) and only 18 apps had ≥9 of the 17 desirable features. The most common features were flexible scheduling that was present in 56.3% (153/272) of the included apps, medication tracking history in 54.8% (149/272), snooze option in 34.9% (95/272), and visual aids in 32.4% (88/272). We classified 54.8% (149/272) of the included apps as advanced medication reminder apps and 45.2% (123/272) as basic medication reminder apps. The advanced apps had a higher number of features per app compared with the

  18. Implementation of the World Health Organization Regional Office for Africa Stepwise Laboratory Quality Improvement Process Towards Accreditation.

    Science.gov (United States)

    Ndihokubwayo, Jean-Bosco; Maruta, Talkmore; Ndlovu, Nqobile; Moyo, Sikhulile; Yahaya, Ali Ahmed; Coulibaly, Sheick Oumar; Kasolo, Francis; Turgeon, David; Abrol, Angelii P

    2016-01-01

    The increase in disease burden has continued to weigh upon health systems in Africa. The role of the laboratory has become increasingly critical in the improvement of health for diagnosis, management and treatment of diseases. In response, the World Health Organization Regional Office for Africa (WHO AFRO) and its partners created the WHO AFRO Stepwise Laboratory (Quality) Improvement Process Towards Accreditation (SLIPTA) program. WHO AFRO defined a governance structure with roles and responsibilities for six main stakeholders. Laboratories were evaluated by auditors trained and certified by the African Society for Laboratory Medicine. Laboratory performance was measured using the WHO AFRO SLIPTA scoring checklist and recognition certificates rated with 1-5 stars were issued. By March 2015, 27 of the 47 (57%) WHO AFRO member states had appointed a SLIPTA focal point and 14 Ministers of Health had endorsed SLIPTA as the desired programme for continuous quality improvement. Ninety-eight auditors from 17 African countries, competent in the Portuguese (3), French (12) and English (83) languages, were trained and certified. The mean score for the 159 laboratories audited between May 2013 and March 2015 was 69% (median 70%; SD 11.5; interquartile range 62-77). Of these audited laboratories, 70% achieved 55% compliance or higher (2 or more stars) and 1% scored at least 95% (5 stars). The lowest scoring sections of the WHO AFRO SLIPTA checklist were sections 6 (Internal Audit) and 10 (Corrective Action), which both had mean scores below 50%. The WHO AFRO SLIPTA is a process that countries with limited resources can adopt for effective implementation of quality management systems. Political commitment, ownership and investment in continuous quality improvement are integral components of the process.

  19. Stepwise O-Atom Transfer in Heme-Based Tryptophan Dioxygenase: Role of Substrate Ammonium in Epoxide Ring Opening.

    Science.gov (United States)

    Shin, Inchul; Ambler, Brett R; Wherritt, Daniel; Griffith, Wendell P; Maldonado, Amanda C; Altman, Ryan A; Liu, Aimin

    2018-03-28

    Heme-based tryptophan dioxygenases are established immunosuppressive metalloproteins with significant biomedical interest. Here, we synthesized two mechanistic probes to specifically test if the α-amino group of the substrate directly participates in a critical step of the O atom transfer during catalysis in human tryptophan 2,3-dioxygenase (TDO). Substitution of the nitrogen atom of the substrate to a carbon (probe 1) or oxygen (probe 2) slowed the catalytic step following the first O atom transfer such that transferring the second O atom becomes less likely to occur, although the dioxygenated products were observed with both probes. A monooxygenated product was also produced from probe 2 in a significant quantity. Analysis of this new product by HPLC coupled UV-vis spectroscopy, high-resolution mass spectrometry, 1 H NMR, 13 C NMR, HSQC, HMBC, and infrared (IR) spectroscopies concluded that this monooxygenated product is a furoindoline compound derived from an unstable epoxyindole intermediate. These results prove that small molecules can manipulate the stepwise O atom transfer reaction of TDO and provide a showcase for a tunable mechanism by synthetic compounds. The product analysis results corroborate the presence of a substrate-based epoxyindole intermediate during catalysis and provide the first substantial experimental evidence for the involvement of the substrate α-amino group in the epoxide ring-opening step during catalysis. This combined synthetic, biochemical, and biophysical study establishes the catalytic role of the α-amino group of the substrate during the O atom transfer reactions and thus represents a substantial advance to the mechanistic comprehension of the heme-based tryptophan dioxygenases.

  20. [Recommendations for the Stepwise Occupational Reintegration: Can the Characteristic of the Patients Explain the Differences Between the Rehabilitation Centers?].

    Science.gov (United States)

    Schmid, L; Jankowiak, S; Kaluscha, R; Krischak, G

    2016-06-01

    The first step to initiate a stepwise occupational reintegration (SOR) is the recommendation of the rehabilitation centers. Therefore rehabilitation centers have a significant impact on the use of SOR. There is evidence that the recommendation rate between the rehabilitation centers differs clearly. The present survey therefore analyses in detail the differences of the recommendation rate and examines which patient-related factors could explain the differences. This study is based on analysis of routine data provided by the German pension insurance in Baden-Württemberg (Rehabilitationsstatistikdatenbasis 2013; RSD). In the analyses rehabilitation measures were included if they were conducted by employed patients (18-64 years) with a muscular-skeletal system disease or a disorder of the connective tissue. Logistic regression models were performed to explain the differences in the recommendation rate of the rehabilitation centers. The data of 134 853 rehabilitation measures out of 32 rehabilitation centers were available. The recommendation rate differed between the rehabilitation centers from 1.36-18.53%. The logistic regression analysis showed that the period of working incapacity 12 month before the rehabilitation and the working capacity on the current job were the most important predictors for the recommendation of a SOR by the rehabilitation centers. Also the rehabilitation centers themselves have an important influence. The results of this survey indicate that the characteristic of the patients is an important factor for the recommendation of SOR. Additionally the rehabilitation centers themselves have an influence on the recommendation of SOR. The results point to the fact that the rehabilitation centers use different criteria by making a recommendation. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Stepwise expansion of a surface dielectric barrier discharge as a result of alternation in formation of streamers and leaders

    International Nuclear Information System (INIS)

    Akishev, Yu; Aponin, G; Balakirev, A; Grushin, M; Petryakov, A; Karal'nik, V; Trushkin, N

    2013-01-01

    Spatial–temporal development of the plasma sheet structure in a surface dielectric barrier discharge (SDBD) powered with a single long pulse of negative polarity is traced. Ambient air and Ar at atmospheric pressure are used as plasma-forming gases. It is found that current regimes and spatial structures occurring at the development of a long-pulsed discharge differ cardinally as compared with those of a short-pulsed SDBD. In the case of long-pulsed SDBDs, the expansion of the barrier area covered by the plasma sheet and seeded with a surface negative charge occurs in a stepwise manner due to cyclic alternation (one after another) in generation of surface streamers and formation of hot surface leaders from the streamers due to streamer–leader transitions. Leaders, in their turn, initiate new streamers, which serve again as precursors for next-step leader formation, and so on. However, the crucial role in surface charge deposition is played not by streamers and leaders but by a diffusive plasma sheet (DPS), which slowly extends from the sides of streamers and leaders. The expansion of the DPS occurs due to the ionization wave propagating from the sides of the streamers and leaders. The difference in spatial structures of a single long-pulsed and a steady-state sin SDBD is studied. In high-frequency sin SDBDs at negative half-cycle there are only leaders and DPS, but there are no streamers. The reason is that there is no necessity for the formation of leaders due to streamer–leader transitions—leaders are formed at the previous cycle and do not decay strongly till the beginning of the next cycle, and they recover themselves without streamers. (paper)

  2. Comparison of different stepwise screening strategies for type 2 diabetes: Finding from Danish general practice, Addition-DK.

    Science.gov (United States)

    Dalsgaard, Else-Marie; Christensen, Jesper O; Skriver, Mette Vinter; Borch-Johnsen, Knut; Lauritzen, Torsten; Sandbaek, Annelli

    2010-12-01

    To examine attendance, number of people with T2DM and costs of three different stepwise screening strategies for T2DM in general practice (GP). Diabetes risk questionnaires were mailed to individuals aged 40-69 years from 45 general practices in 2001-2002 and individuals at high risk for T2DM, were asked to contact their GP to arrange a screening test. In 2005-2006, 26 general practices were randomised into two different opportunistic screening programmes (OP-direct and OP-subsequent) and risk questionnaires were distributed to individuals aged 40-69 years during GP consultations. In the OP-direct approach, high-risk individuals were offered to start the screening during the actual consultation while high-risk individuals in the OP-subsequent approach, were invited to a screening test at a later date. We report attendance, number of people with T2DM and costs of each screening approach. The mail-distributed approach identified 0.8% of the target population with T2DM, the OP-direct approach and the OP-subsequent approach, 0.9% and 0.5% respectively. Cost per person with T2DM was in the mail-distributed approach: € 1058, OP-direct approach: € 707 and the OP-subsequent approach: € 727. This study indicates that opportunistic screening identifies the same level of unknown diabetes as a mail-distributed approach but with lower costs. Copyright © 2010 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

  3. Successful implementation of the stepwise layer-by-layer growth of MOF thin films on confined surfaces: Mesoporous silica foam as a first case study

    KAUST Repository

    Shekhah, Osama; Fu, Lei; Sougrat, Rachid; Belmabkhout, Youssef; Cairns, Amy; Giannelis, Emmanuel P.; Eddaoudi, Mohamed

    2012-01-01

    Here we report the successful growth of highly crystalline homogeneous MOF thin films of HKUST-1 and ZIF-8 on mesoporous silica foam, by employing a layer-by-layer (LBL) method. The ability to control and direct the growth of MOF thin films on confined surfaces, using the stepwise LBL method, paves the way for new prospective applications of such hybrid systems. © 2012 The Royal Society of Chemistry.

  4. The concern of emergence of multi-station reaction pathways that might make stepwise the mechanism of the 1,3-dipolar cycloadditions of azides and alkynes

    Science.gov (United States)

    Mohtat, Bita; Siadati, Seyyed Amir; Khalilzadeh, Mohammad Ali; Zareyee, Daryoush

    2018-03-01

    After hot debates on the concerted or stepwise nature of the mechanism of the catalyst-free 1,3-dipolar cycloadditions (DC)s, nowadays, it is being believed that for the reaction of each dipole and dipolarophile, there is a possibility that the reaction mechanism becomes stepwise, intermediates emerge, and the reaction becomes non-stereospecific. Yield of even minimal amounts of unwanted side products or stereoisomers as impurities could bring many troubles like difficult purification steps. In this project, we have made attempts to study all probable reaction channels of the azide cycloadditions with two functionalized alkynes, in order to answer this question: "is there any possibility that intermediates evolve in the catalyst-free click 1,3-DC reaction of azide-alkynes?". During the calculations, several multi-station reaction pathways supporting the stepwise and concerted mechanisms were detected. Also, the born-oppenheimer molecular dynamic (BOMD) simulation was used to find trustable geometries which could be emerged during the reaction coordinate.

  5. Localized, stepwise template growth of functional nanowires from an amino acid-supported framework in a microfluidic chip.

    Science.gov (United States)

    Puigmartí-Luis, Josep; Rubio-Martínez, Marta; Imaz, Inhar; Cvetković, Benjamin Z; Abad, Llibertat; Pérez Del Pino, Angel; Maspoch, Daniel; Amabilino, David B

    2014-01-28

    A spatially controlled synthesis of nanowire bundles of the functional crystalline coordination polymer (CP) Ag(I)TCNQ (tetracyanoquinodimethane) from previously fabricated and trapped monovalent silver CP (Ag(I)Cys (cysteine)) using a room-temperature microfluidic-assisted templated growth method is demonstrated. The incorporation of microengineered pneumatic clamps in a two-layer polydimethylsiloxane-based (PDMS) microfluidic platform was used. Apart from guiding the formation of the Ag(I)Cys coordination polymer, this microfluidic approach enables a local trapping of the in situ synthesized structures with a simple pneumatic clamp actuation. This method not only enables continuous and multiple chemical events to be conducted upon the trapped structures, but the excellent fluid handling ensures a precise chemical activation of the amino acid-supported framework in a position controlled by interface and clamp location that leads to a site-specific growth of Ag(I)TCNQ nanowire bundles. The synthesis is conducted stepwise starting with Ag(I)Cys CPs, going through silver metal, and back to a functional CP (Ag(I)TCNQ); that is, a novel microfluidic controlled ligand exchange (CP → NP → CP) is presented. Additionally, the pneumatic clamps can be employed further to integrate the conductive Ag(I)TCNQ nanowire bundles onto electrode arrays located on a surface, hence facilitating the construction of the final functional interfaced systems from solution specifically with no need for postassembly manipulation. This localized self-supported growth of functional matter from an amino acid-based CP shows how sequential localized chemistry in a fluid cell can be used to integrate molecular systems onto device platforms using a chip incorporating microengineered pneumatic tools. The control of clamp pressure and in parallel the variation of relative flow rates of source solutions permit deposition of materials at different locations on a chip that could be useful for device

  6. The role of multicollinearity in landslide susceptibility assessment by means of Binary Logistic Regression: comparison between VIF and AIC stepwise selection

    Science.gov (United States)

    Cama, Mariaelena; Cristi Nicu, Ionut; Conoscenti, Christian; Quénéhervé, Geraldine; Maerker, Michael

    2016-04-01

    Landslide susceptibility can be defined as the likelihood of a landslide occurring in a given area on the basis of local terrain conditions. In the last decades many research focused on its evaluation by means of stochastic approaches under the assumption that 'the past is the key to the future' which means that if a model is able to reproduce a known landslide spatial distribution, it will be able to predict the future locations of new (i.e. unknown) slope failures. Among the various stochastic approaches, Binary Logistic Regression (BLR) is one of the most used because it calculates the susceptibility in probabilistic terms and its results are easily interpretable from a geomorphological point of view. However, very often not much importance is given to multicollinearity assessment whose effect is that the coefficient estimates are unstable, with opposite sign and therefore difficult to interpret. Therefore, it should be evaluated every time in order to make a model whose results are geomorphologically correct. In this study the effects of multicollinearity in the predictive performance and robustness of landslide susceptibility models are analyzed. In particular, the multicollinearity is estimated by means of Variation Inflation Index (VIF) which is also used as selection criterion for the independent variables (VIF Stepwise Selection) and compared to the more commonly used AIC Stepwise Selection. The robustness of the results is evaluated through 100 replicates of the dataset. The study area selected to perform this analysis is the Moldavian Plateau where landslides are among the most frequent geomorphological processes. This area has an increasing trend of urbanization and a very high potential regarding the cultural heritage, being the place of discovery of the largest settlement belonging to the Cucuteni Culture from Eastern Europe (that led to the development of the great complex Cucuteni-Tripyllia). Therefore, identifying the areas susceptible to

  7. Adaptive evolution of Escherichia coli to Ciprofloxacin in controlled stress environments: emergence of resistance in continuous and step-wise gradients

    Science.gov (United States)

    Deng, J.; Zhou, L.; Dong, Y.; Sanford, R. A.; Shechtman, L. A.; Alcalde, R.; Werth, C. J.; Fouke, B. W.

    2017-12-01

    Microorganisms in nature have evolved in response to a variety of environmental stresses, including gradients in pH, flow and chemistry. While environmental stresses are generally considered to be the driving force of adaptive evolution, the impact and extent of any specific stress needed to drive such changes has not been well characterized. In this study, a microfluidic diffusion chamber (MDC) and a batch culturing system were used to systematically study the effects of continuous versus step-wise stress increments on adaptation of E. coli to the antibiotic ciprofloxacin. In the MDC, a diffusion gradient of ciprofloxacin was established across a microfluidic well array to microscopically observe changes in Escherichia coli strain 307 replication and migration patterns that would indicate emergence of resistance due to genetic mutations. Cells recovered from the MDC only had resistance of 50-times the original minimum inhibition concentration (MICoriginal) of ciprofloxacin, although minimum exposure concentrations were over 80 × MICoriginal by the end of the experiment. In complementary batch experiments, E. coli 307 were exposed to step-wise daily increases of ciprofloxacin at rates equivalent to 0.1×, 0.2×, 0.4× or 0.8× times MICoriginal/day. Over a period of 18 days, E. coli cells were able to acquire resistance of up to 225 × MICoriginal, with exposure to ciprofloxacin concentration up to only 14.9 × MIC­original. The different levels of acquired resistance in the continuous MDC versus step-wise batch increment experiments suggests that the intrinsic rate of E. coli adaptation was exceeded in the MDC, while the step-wise experiments favor adaptation to the highest ciprofloxacin experiments. Genomic analyses of E. coli DNA extracted from the microfluidic cell and batch cultures indicated four single nucleotide polymorphism (SNP) mutations of amino acid 82, 83 and 87 in the gyrA gene. The progression of adaptation in the step-wise increments of

  8. Screening agars for MRSA: evaluation of a stepwise diagnostic approach with two different selective agars for the screening for methicillin-resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Micheel, Volker; Hogan, Benedikt; Köller, Thomas; Warnke, Philipp; Crusius, Sabine; Hinz, Rebecca; Hagen, Ralf Matthias; Schwarz, Norbert Georg; Frickmann, Hagen

    2015-01-01

    Colonization with methicillin-resistant Staphylococcus aureus (MRSA) poses a hygiene risk that does not spare field hospitals or military medical field camps during military deployments. Diagnostic options for unambiguously identifying MRSA isolates are usually scarce in military environments. In this study, we assessed the stepwise application of two different selective agars for the specific identification of MRSA in screening analyses. Nasal swabs from 1541 volunteers were subjected to thioglycollate broth enrichment and subsequently screened on CHROMagar MRSA selective agar for the identification of MRSA. The MRSA identity of suspicious-looking colonies was confirmed afterwards or excluded by another selective agar, chromID MRSA. All isolates from the selective agars with MRSA-specific colony morphology were identified by biochemical methods and mass spectrometry. The initial CHROMagar MRSA screening identified suspicious colonies in 36 out of 1541 samples. A total of 25 of these 36 isolates showed MRSA-like growth on chromID agar. Out of these 25 isolates, 24 were confirmed as MRSA, while one isolate was identified as Staphylococcus kloosii. From the 11 strains that did not show suspicious growth on chromID agar, 3 were methicillin-sensitive Staphylococcus aureus (MSSA, with one instance of co-colonization with Corynebacterium spp.), 2 were confirmed as MRSA (with 1 instance of co-colonization with MSSA), 2 were lost during passaging and could not be re-cultured, one could not be identified by the applied approaches, and the remaining 3 strains were identified as Staphylococcus saprophyticus, Staphylococcus hominis (co-colonized with Macrococcus caseolyticus) and Staphylococcus cohnii, respectively. The application of the selective agar CHROMagar MRSA alone proved to be too non-specific to allow for a reliable diagnosis of the presence of MRSA. The combined use of two selective agars in a stepwise approach reduced this non-specificity with an acceptably low

  9. Isolation and Characterization of Chinese Standard Fulvic Acid Sub-fractions Separated from Forest Soil by Stepwise Elution with Pyrophosphate Buffer

    Science.gov (United States)

    Bai, Yingchen; Wu, Fengchang; Xing, Baoshan; Meng, Wei; Shi, Guolan; Ma, Yan; Giesy, John P.

    2015-01-01

    XAD-8 adsorption technique coupled with stepwise elution using pyrophosphate buffers with initial pH values of 3, 5, 7, 9, and 13 was developed to isolate Chinese standard fulvic acid (FA) and then separated the FA into five sub-fractions: FApH3, FApH5, FApH7, FApH9 and FApH13, respectively. Mass percentages of FApH3-FApH13 decreased from 42% to 2.5%, and the recovery ratios ranged from 99.0% to 99.5%. Earlier eluting sub-fractions contained greater proportions of carboxylic groups with greater polarity and molecular mass, and later eluting sub-fractions had greater phenolic and aliphatic content. Protein-like components, as well as amorphous and crystalline poly(methylene)-containing components were enriched using neutral and basic buffers. Three main mechanisms likely affect stepwise elution of humic components from XAD-8 resin with pyrophosphate buffers including: 1) the carboxylic-rich sub-fractions are deprotonated at lower pH values and eluted earlier, while phenolic-rich sub-fractions are deprotonated at greater pH values and eluted later. 2) protein or protein-like components can be desorbed and eluted by use of stepwise elution as progressively greater pH values exceed their isoelectric points. 3) size exclusion affects elution of FA sub-fractions. Successful isolation of FA sub-fractions will benefit exploration of the origin, structure, evolution and the investigation of interactions with environmental contaminants. PMID:25735451

  10. Stepwise Ti-Cl, Ti-CH3, and Ti-C6H5 bond dissociation enthalpies in bis(pentamethylcyclopentadienyl)titanium complexes

    NARCIS (Netherlands)

    Dias, Alberto R.; Salema, Margarida S.; Martinho Simões, Jose A.; Pattiasina, Johannes W.; Teuben, Jan H.

    1988-01-01

    Reaction-solution calorimetric studies involving the complexes Ti[η5-C5(CH3)5]2(CH3)2, Ti[η5-C5(CH3)5]2(CH3), Ti[η5-C5(CH3)5]2(C6H5), Ti[η5-C5(CH3)5]2Cl2, and Ti[η5-C5(CH3)5]2Cl, have enabled derivation of titanium-carbon and titanium-chlorine stepwise bond dissociation enthalpies in these species.

  11. Real-time MRI-guided percutaneous sclerotherapy of low-flow head and neck lymphatic malformations in the pediatric population - a stepwise approach

    Energy Technology Data Exchange (ETDEWEB)

    Partovi, Sasan; Vidal, Lorenna; Lu, Ziang; Nakamoto, Dean A.; Buethe, Ji; Clampitt, Mark; Coffey, Michael; Patel, Indravadan J. [University Hospitals Cleveland Medical Center, Case Western Reserve University, Department of Radiology, Section of Vascular and Interventional Radiology, Cleveland, OH (United States)

    2017-05-15

    Real-time MRI-guided percutaneous sclerotherapy is a novel and evolving treatment for congenital lymphatic malformations in the head and neck. We elaborate on the specific steps necessary to perform an MRI-guided percutaneous sclerotherapy of lymphatic malformations including pre-procedure patient work-up and preparation, stepwise intraprocedural interventional techniques and post-procedure management. Based on our institutional experience, MRI-guided sclerotherapy with a doxycycline-gadolinium-based mixture as a sclerosant for lymphatic malformations of the head and neck region in children is well tolerated and effective. (orig.)

  12. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    OpenAIRE

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-01

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was perfor...

  13. A water quality index model using stepwise regression and neural networks models for the Piabanha River basin in Rio de Janeiro, Brazil

    Science.gov (United States)

    Villas Boas, M. D.; Olivera, F.; Azevedo, J. S.

    2013-12-01

    The evaluation of water quality through 'indexes' is widely used in environmental sciences. There are a number of methods available for calculating water quality indexes (WQI), usually based on site-specific parameters. In Brazil, WQI were initially used in the 1970s and were adapted from the methodology developed in association with the National Science Foundation (Brown et al, 1970). Specifically, the WQI 'IQA/SCQA', developed by the Institute of Water Management of Minas Gerais (IGAM), is estimated based on nine parameters: Temperature Range, Biochemical Oxygen Demand, Fecal Coliforms, Nitrate, Phosphate, Turbidity, Dissolved Oxygen, pH and Electrical Conductivity. The goal of this study was to develop a model for calculating the IQA/SCQA, for the Piabanha River basin in the State of Rio de Janeiro (Brazil), using only the parameters measurable by a Multiparameter Water Quality Sonde (MWQS) available in the study area. These parameters are: Dissolved Oxygen, pH and Electrical Conductivity. The use of this model will allow to further the water quality monitoring network in the basin, without requiring significant increases of resources. The water quality measurement with MWQS is less expensive than the laboratory analysis required for the other parameters. The water quality data used in the study were obtained by the Geological Survey of Brazil in partnership with other public institutions (i.e. universities and environmental institutes) as part of the project "Integrated Studies in Experimental and Representative Watersheds". Two models were developed to correlate the values of the three measured parameters and the IQA/SCQA values calculated based on all nine parameters. The results were evaluated according to the following validation statistics: coefficient of determination (R2), Root Mean Square Error (RMSE), Akaike information criterion (AIC) and Final Prediction Error (FPE). The first model was a linear stepwise regression between three independent variables

  14. Plasma lactate and stress hormones in common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) during stepwise decreasing oxygen levels

    NARCIS (Netherlands)

    Vianen, GJ; Van den Thillart, GEEJM; Van Kampen, M; Van Heel, TI; Steffens, AB

    By measuring the lactate response it is possible to determine whether a teleost is able to adapt to a certain oxygen level. It is hypothesized that recovery will occur at oxygen levels above the critical oxygen level (PO2)(crit) reflected by a transient lactate increase. In contrast, continuous

  15. Timing, cause and impact of the late Eocene stepwise sea retreat from the Tarim Basin (west China)

    NARCIS (Netherlands)

    Bosboom, R.|info:eu-repo/dai/nl/322947359; Dupont-Nivet, G.|info:eu-repo/dai/nl/313092559; Grothe, A.|info:eu-repo/dai/nl/338017712; Brinkhuis, H.|info:eu-repo/dai/nl/095046097; Villa, G.; Mandic, O.; Stoica, M.; Kouwenhoven, T.J.|info:eu-repo/dai/nl/191377406; Huang, W.; Yang, W.; Guo, Z.

    2014-01-01

    A vast shallow epicontinental sea extended across Eurasia and was well-connected to the Western Tethys before it retreated westward and became isolated as the Paratethys Sea. However, the palaeogeography and the timing of this westward retreat are too poorly constrained to determine potential wider

  16. Using interlayer step-wise triplet transfer to achieve an efficient white organic light-emitting diode with high color-stability

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qi [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Department of Electrical Engineering and Computer Sciences, College of Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Ma, Dongge, E-mail: mdg1014@ciac.jl.cn; Ding, Junqiao; Wang, Lixiang [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022 (China); Leo, Karl [Tech. Univ. Dresden, Inst. Angew. Photophys., D-01062 Dresden (Germany); Qiao, Qiquan [Department of Electrical Engineering and Computer Sciences, College of Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Jia, Huiping; Gnade, Bruce E. [Department of Materials Science and Engineering and Erik Jonsson School of Engineering and Computer Science, University of Texas at Dallas, Richardson, Texas 75083 (United States)

    2014-05-12

    An efficient phosphorescent white organic light emitting-diode with a red-green-blue tri-emitting-layer structure is reported. The host of the red dopant possesses a lower triplet-energy than the green dye. An interlayer step-wise triplet transfer via blue dye → green dye → red host → red dye is achieved. This mechanism allows an efficient triplet harvesting by the three dopants, thus maintaining a balanced white light and reducing energy loss. Moreover, the color stability of the device is improved significantly. The white device not only achieves a peak external quantum efficiency of 21.1 ± 0.8% and power efficiency of 37.5 ± 1.4 lm/W but shows no color shift over a wide range of voltages.

  17. Selective epitaxial growth of stepwise SiGe:B at the recessed sources and drains: A growth kinetics and strain distribution study

    Directory of Open Access Journals (Sweden)

    Sangmo Koo

    2016-09-01

    Full Text Available The selective epitaxial growth of Si1-xGex and the related strain properties were studied. Epitaxial Si1-xGex films were deposited on (100 and (110 orientation wafers and on patterned Si wafers with recessed source and drain structures via ultrahigh vacuum chemical vapor deposition using different growing steps and Ge concentrations. The stepwise process was split into more than 6 growing steps that ranged in thicknesses from a few to 120 nm in order to cover the wide stages of epitaxial growth. The growth rates of SiGe on the plane and patterned wafers were examined and a dependence on the surface orientation was identified. As the germanium concentration increased, defects were generated with thinner Si1-xGex growth. The defect generation was the result of the strain evolution which was examined for channel regions with a Si1-xGex source/drain (S/D structure.

  18. Acquisition of a potent and selective TC-PTP inhibitor via a stepwise fluorophore-tagged combinatorial synthesis and screening strategy.

    Science.gov (United States)

    Zhang, Sheng; Chen, Lan; Luo, Yong; Gunawan, Andrea; Lawrence, David S; Zhang, Zhong-Yin

    2009-09-16

    Protein tyrosine phosphatases (PTPs) regulate a broad range of cellular processes including proliferation, differentiation, migration, apoptosis, and immune responses. Dysfunction of PTP activity is associated with cancers, metabolic syndromes, and autoimmune disorders. Consequently, small molecule PTP inhibitors should serve not only as powerful tools to delineate the physiological roles of these enzymes in vivo but also as lead compounds for therapeutic development. We describe a novel stepwise fluorophore-tagged combinatorial library synthesis and competitive fluorescence polarization screening approach that transforms a weak and general PTP inhibitor into an extremely potent and selective TC-PTP inhibitor with highly efficacious cellular activity. The result serves as a proof-of-concept in PTP inhibitor development, as it demonstrates the feasibility of acquiring potent, yet highly selective, cell permeable PTP inhibitory agents. Given the general nature of the approach, this strategy should be applicable to other PTP targets.

  19. Evaluation of a novel, hybrid model (Mumbai EUS II) for stepwise teaching and training in EUS-guided biliary drainage and rendezvous procedures

    Science.gov (United States)

    Dhir, Vinay; Itoi, Takao; Pausawasdi, Nonthalee; Khashab, Mouen A.; Perez-Miranda, Manuel; Sun, Siyu; Park, Do Hyun; Iwashita, Takuji; Teoh, Anthony Y. B.; Maydeo, Amit P.; Ho, Khek Yu

    2017-01-01

    Background and aims  EUS-guided biliary drainage (EUS-BD) and rendezvous (EUS-RV) are acceptable rescue options for patients with failed endoscopic retrograde cholangiopancreatography (ERCP). However, there are limited training opportunities at most centers owing to low case volumes. The existing models do not replicate the difficulties encountered during EUS-BD. We aimed to develop and validate a model for stepwise learning of EUS-BD and EUS-RV, which replicates the actual EUS-BD procedures. Methods  A hybrid model was created utilizing pig esophagus and stomach, with a synthetic duodenum and biliary system. The model was objectively assessed on a grade of 1 – 4 by two experts. Twenty-eight trainees were given initial training with didactic lectures and live procedures. This was followed by hands-on training in EUS-BD and EUS-RV on the hybrid model. Trainees were assessed for objective criteria of technical difficulties. Results  Both the experts graded the model as very good or above for all parameters. All trainees could complete the requisite steps of EUS-BD and EUS-RV in a mean time of 11 minutes (8 – 18 minutes). Thirty-six technical difficulties were noted during the training (wrong scope position, 13; incorrect duct puncture, 12; guidewire related problems, 11). Technical difficulties peaked for EUS-RV, followed by hepaticogastrostomy (HGS) and choledochoduodenostomy (CDS) (20, 9, and 7, P  = 0.001). At 10 days follow-up, nine of 28 trainees had successfully performed three EUS-RV and seven EUS-BD procedures independently. Conclusions  The Mumbai EUS II hybrid model replicates situations encountered during EUS-RV and EUS-BD. Stepwise mentoring improves the chances of success in EUS-RV and EUS-BD procedures. PMID:29250585

  20. Combined use of fasting plasma glucose and glycated hemoglobin A1c in a stepwise fashion to detect undiagnosed diabetes mellitus.

    Science.gov (United States)

    Nakagami, Tomoko; Tominaga, Makoto; Nishimura, Rimei; Daimon, Makoto; Oizumi, Toshihide; Yoshiike, Nobuo; Tajima, Naoko

    2007-09-01

    Type 2 diabetes mellitus (DM) is a common and serious condition related with considerable morbidity. Screening for DM is one strategy for reducing this burden. In Japan National Diabetes Screening Program (JNDSP) guideline, the combined use of fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) in a stepwise fashion has been recommended to identify the group of people needing life-style counseling or medical care. However, the efficacy of this program has not been fully evaluated, as an oral glucose tolerance test (OGTT) is not mandatory in the guideline. The aim of this study was to assess the validity of the screening test scenario, in which an OGTT would be applied to people needing life-style counseling or medical care on this guideline: FPG 110-125 mg/dl and HbA1c over 5.5%. Subjects were 1,726 inhabitants without a previous history of DM in the Funagata study, which is a population-based survey conducted in Yamagata prefecture to clarify the risk factors, related conditions, and consequences of DM. DM was diagnosed according to the 1999 World Health Organization criteria. The prevalence of undiagnosed DM was 6.6%. The tested screening scenario gave a sensitivity of 55.3%, a specificity of 98.4%, a positive predictive value of 70.8%, and a negative predictive value of 96.9% for undiagnosed DM. In conclusion, the screening test scenario, in which an OGTT would be followed by the combined use of FPG and HbA1c in a stepwise fashion according to the JNDSP guideline, was not effective in identifying people with undiagnosed DM.

  1. Evaluation of a novel, hybrid model (Mumbai EUS II) for stepwise teaching and training in EUS-guided biliary drainage and rendezvous procedures.

    Science.gov (United States)

    Dhir, Vinay; Itoi, Takao; Pausawasdi, Nonthalee; Khashab, Mouen A; Perez-Miranda, Manuel; Sun, Siyu; Park, Do Hyun; Iwashita, Takuji; Teoh, Anthony Y B; Maydeo, Amit P; Ho, Khek Yu

    2017-11-01

     EUS-guided biliary drainage (EUS-BD) and rendezvous (EUS-RV) are acceptable rescue options for patients with failed endoscopic retrograde cholangiopancreatography (ERCP). However, there are limited training opportunities at most centers owing to low case volumes. The existing models do not replicate the difficulties encountered during EUS-BD. We aimed to develop and validate a model for stepwise learning of EUS-BD and EUS-RV, which replicates the actual EUS-BD procedures.  A hybrid model was created utilizing pig esophagus and stomach, with a synthetic duodenum and biliary system. The model was objectively assessed on a grade of 1 - 4 by two experts. Twenty-eight trainees were given initial training with didactic lectures and live procedures. This was followed by hands-on training in EUS-BD and EUS-RV on the hybrid model. Trainees were assessed for objective criteria of technical difficulties.  Both the experts graded the model as very good or above for all parameters. All trainees could complete the requisite steps of EUS-BD and EUS-RV in a mean time of 11 minutes (8 - 18 minutes). Thirty-six technical difficulties were noted during the training (wrong scope position, 13; incorrect duct puncture, 12; guidewire related problems, 11). Technical difficulties peaked for EUS-RV, followed by hepaticogastrostomy (HGS) and choledochoduodenostomy (CDS) (20, 9, and 7, P  = 0.001). At 10 days follow-up, nine of 28 trainees had successfully performed three EUS-RV and seven EUS-BD procedures independently.  The Mumbai EUS II hybrid model replicates situations encountered during EUS-RV and EUS-BD. Stepwise mentoring improves the chances of success in EUS-RV and EUS-BD procedures.

  2. Technique of stepwise intracranial decompression combined with external ventricular drainage catheters improve the prognosis of acute post-traumatic hemispheric brain swelling patients

    Directory of Open Access Journals (Sweden)

    Lei eShi

    2015-09-01

    Full Text Available Background: Acute post-traumatic cerebral hemispheric brain swelling (ACHS is a serious disorder that occurs after traumatic brain injury (TBI, and it often requires immediate treatment. The aim of our clinical study was to assess the effects of stepwise intracranial decompression combined with external ventricular drainage catheters on the prognosis of ACHS patients.Methods: A retrospective study was performed on 172 cases of severe craniocerebral trauma patients with acute cerebral hemispheric swelling. The patients were divided into two groups: unilateral stepwise standard large trauma craniectomy (S-SLTC combined with external ventricular drainage (EVD catheter implants (n = 86 and unilateral routine frontal temporal parietal SLTC (control group, n = 86.Result: No significant differences in age, sex, or preoperative Glasgow Coma Scale score were observed between groups (P < 0.05. There were no significant differences in the ipsilateral subdural effusion incidence rates between the S-SLTC+EVD treatment group and the routine SLTC group. However, the incidence rates of intraoperative acute encephalocele and contralateral epidural and subdural hematoma in the S-SLTC+EVD group were significantly lower than those in the SLTC group (17.4% and 3.5% vs. 37.2% and 23.3%, respectively. The mean intracranial pressure (ICP values of patients in the S-SLTC+EVD group were also lower than those in the SLTC group at days 1 through7 (P<0.05. A positive neurological outcome (GOS score 4 to 5, 50.0% and decreased mortality (15.1% was observed in the S-SLTC+EVD group compared to the neurological outcome (GOS score 4 to 5, 33.8%; 36.0% in the SLTC group (P<0.05.Conclusions: Our data suggest that S-SLTC+EVD is more effective for controlling ICP, improving neurological outcome, and decreasing mortality rate compared with routine SLTC.

  3. Dynamic in vivo binding of transcription factors to cis-regulatory modules of cer and gsc in the stepwise formation of the Spemann–Mangold organizer

    Science.gov (United States)

    Sudou, Norihiro; Yamamoto, Shinji; Ogino, Hajime; Taira, Masanori

    2012-01-01

    How multiple developmental cues are integrated on cis-regulatory modules (CRMs) for cell fate decisions remains uncertain. The Spemann–Mangold organizer in Xenopus embryos expresses the transcription factors Lim1/Lhx1, Otx2, Mix1, Siamois (Sia) and VegT. Reporter analyses using sperm nuclear transplantation and DNA injection showed that cerberus (cer) and goosecoid (gsc) are activated by the aforementioned transcription factors through CRMs conserved between X. laevis and X. tropicalis. ChIP-qPCR analysis for the five transcription factors revealed that cer and gsc CRMs are initially bound by both Sia and VegT at the late blastula stage, and subsequently bound by all five factors at the gastrula stage. At the neurula stage, only binding of Lim1 and Otx2 to the gsc CRM, among others, persists, which corresponds to their co-expression in the prechordal plate. Based on these data, together with detailed expression pattern analysis, we propose a new model of stepwise formation of the organizer, in which (1) maternal VegT and Wnt-induced Sia first bind to CRMs at the blastula stage; then (2) Nodal-inducible Lim1, Otx2, Mix1 and zygotic VegT are bound to CRMs in the dorsal endodermal and mesodermal regions where all these genes are co-expressed; and (3) these two regions are combined at the gastrula stage to form the organizer. Thus, the in vivo dynamics of multiple transcription factors highlight their roles in the initiation and maintenance of gene expression, and also reveal the stepwise integration of maternal, Nodal and Wnt signaling on CRMs of organizer genes to generate the organizer. PMID:22492356

  4. Dynamic in vivo binding of transcription factors to cis-regulatory modules of cer and gsc in the stepwise formation of the Spemann-Mangold organizer.

    Science.gov (United States)

    Sudou, Norihiro; Yamamoto, Shinji; Ogino, Hajime; Taira, Masanori

    2012-05-01

    How multiple developmental cues are integrated on cis-regulatory modules (CRMs) for cell fate decisions remains uncertain. The Spemann-Mangold organizer in Xenopus embryos expresses the transcription factors Lim1/Lhx1, Otx2, Mix1, Siamois (Sia) and VegT. Reporter analyses using sperm nuclear transplantation and DNA injection showed that cerberus (cer) and goosecoid (gsc) are activated by the aforementioned transcription factors through CRMs conserved between X. laevis and X. tropicalis. ChIP-qPCR analysis for the five transcription factors revealed that cer and gsc CRMs are initially bound by both Sia and VegT at the late blastula stage, and subsequently bound by all five factors at the gastrula stage. At the neurula stage, only binding of Lim1 and Otx2 to the gsc CRM, among others, persists, which corresponds to their co-expression in the prechordal plate. Based on these data, together with detailed expression pattern analysis, we propose a new model of stepwise formation of the organizer, in which (1) maternal VegT and Wnt-induced Sia first bind to CRMs at the blastula stage; then (2) Nodal-inducible Lim1, Otx2, Mix1 and zygotic VegT are bound to CRMs in the dorsal endodermal and mesodermal regions where all these genes are co-expressed; and (3) these two regions are combined at the gastrula stage to form the organizer. Thus, the in vivo dynamics of multiple transcription factors highlight their roles in the initiation and maintenance of gene expression, and also reveal the stepwise integration of maternal, Nodal and Wnt signaling on CRMs of organizer genes to generate the organizer.

  5. A perspective of stepwise utilisation of Bayer red mud: Step two—Extracting and recovering Ti from Ti-enriched tailing with acid leaching and precipitate flotation

    International Nuclear Information System (INIS)

    Huang, Yanfang; Chai, Wencui; Han, Guihong; Wang, Wenjuan; Yang, Shuzhen; Liu, Jiongtian

    2016-01-01

    Highlights: • An integrated process for the stepwise disposal of red mud was proposed. • Extracting and recovering Ti from Ti-enriched tailing was the second step. • The factors influencing acid leaching and precipitate flotation were examined. • The extracting of metals in concentrated H 2 SO 4 was controlled by diffusion reactions. • [Hbet][Tf 2 N] was an effective precipitating reagent with its coordination mechanism. - Abstract: The extraction and recovery of Ti from Ti-enriched tailing with acid leaching and precipitate flotation, as one of the critical steps, was proposed for the stepwise utilization of red mud. The factors influencing acid leaching and precipitate flotation were examined by factorial design. The leaching thermodynamics, kinetics of Ti 4+ , Al 3+ and Fe 3+ , and the mechanism of selectively Fe 3+ removal using [Hbet][Tf 2 N] as precipitating reagent were discussed. The extracting of Ti 4+ , Al 3+ and Fe 3+ in concentrated H 2 SO 4 is controlled by diffusion reactions, depending mainly upon leaching time and temperature. The maximum extracting efficiency of Ti 4+ is approximately 92.3%, whereas Al 3+ and Fe 3+ leaching are respectively 75.8% and 84.2%. [Hbet][Tf 2 N], as a precipitating reagent, operates through a coordination mechanism in flotation. The pH value is the key factor influencing the flotation recovery of Ti 4+ , whereas the dosage of precipitating reagent is that for Al 3+ recovery. The maximum flotation recovery of Ti 4+ is 92.7%, whereas the maximum Al 3+ recovery is 93.5%. The total recovery rate for extracting and recovering titanium is 85.5%. The liquor with Ti 4+ of 15.5 g/L, Al 3+ of 30.4 g/L and Fe 3+ of 0.48 g/L was obtained for the following hydrolysis step in the integrated process for red mud utilisation.

  6. Molecular Structures and Dynamics of the Stepwise Activation Mechanism of a Matrix Metalloproteinase Zymogen: Challenging the Cysteine Switch Dogma

    International Nuclear Information System (INIS)

    Rosenblum, G.; Meroueh, S.; Toth, M.; Fisher, J.; Fridman, R.; Mobashery, S.; Sagi, I.

    2007-01-01

    Activation of matrix metalloproteinase zymogen (pro-MMP) is a vital homeostatic process, yet its molecular basis remains unresolved. Using stopped-flow X-ray spectroscopy of the active site zinc ion, we determined the temporal sequence of pro-MMP-9 activation catalyzed by tissue kallikrein protease in milliseconds to several minutes. The identity of three intermediates seen by X-ray spectroscopy was corroborated by molecular dynamics simulations and quantum mechanics/molecular mechanics calculations. The cysteine-zinc interaction that maintains enzyme latency is disrupted via active-site proton transfers that mediate transient metal-protein coordination events and eventual binding of water. Unexpectedly, these events ensue as a direct result of complexation of pro-MMP-9 and kallikrein and occur before proteolysis and eventual dissociation of the pro-peptide from the catalytic site. Here we demonstrate the synergism among long-range protein conformational transitions, local structural rearrangements, and fine atomic events in the process of zymogen activation.

  7. Stepwise observation and quantification and mixed matrix membrane separation of CO2 within a hydroxy-decorated porous host.

    Science.gov (United States)

    Morris, Christopher G; Jacques, Nicholas M; Godfrey, Harry G W; Mitra, Tamoghna; Fritsch, Detlev; Lu, Zhenzhong; Murray, Claire A; Potter, Jonathan; Cobb, Tom M; Yuan, Fajin; Tang, Chiu C; Yang, Sihai; Schröder, Martin

    2017-04-01

    The identification of preferred binding domains within a host structure provides important insights into the function of materials. State-of-the-art reports mostly focus on crystallographic studies of empty and single component guest-loaded host structures to determine the location of guests. However, measurements of material properties ( e.g. , adsorption and breakthrough of substrates) are usually performed for a wide range of pressure (guest coverage) and/or using multi-component gas mixtures. Here we report the development of a multifunctional gas dosing system for use in X-ray powder diffraction studies on Beamline I11 at Diamond Light Source. This facility is fully automated and enables in situ crystallographic studies of host structures under (i) unlimited target gas loadings and (ii) loading of multi-component gas mixtures. A proof-of-concept study was conducted on a hydroxyl-decorated porous material MFM-300(V III ) under (i) five different CO 2 pressures covering the isotherm range and (ii) the loading of equimolar mixtures of CO 2 /N 2 . The study has successfully captured the structural dynamics underpinning CO 2 uptake as a function of surface coverage. Moreover, MFM-300(V III ) was incorporated in a mixed matrix membrane (MMM) with PIM-1 in order to evaluate the CO 2 /N 2 separation potential of this material. Gas permeation measurements on the MMM show a great improvement over the bare PIM-1 polymer for CO 2 /N 2 separation based on the ideal selectivity.

  8. A Stepwise, Participatory Approach to Design and Implement Community Based Adaptation to Drought in the Peruvian Andes

    Directory of Open Access Journals (Sweden)

    Ralph Lasage

    2015-02-01

    Full Text Available The livelihoods of people in the Andes are expected to be affected by climate change due to their dependence on glacier water. The observed decrease in glacier volume over the last few decades is likely to accelerate during the current century, which will affect water availability in the region. This paper presents an approach for participatory development of community-based adaptation measures to cope with the projected impacts of climate change. It combines in an innovative manner participatory design with physical measurements, modeling and a vulnerability analysis. Vulnerability to drought is made operational for households in a catchment of the Ocoña River basin in Peru. On the basis of a household survey (n = 94 we explore how a vulnerability index (risk divided by response efficacy can be used to assess the distribution of vulnerability over households, and how socio-economic factors determine this vulnerability. Water entitlement, area of irrigated land, income and education are all significantly correlated with vulnerability to drought. The research showed that the main source of spring water is local rainwater, and that water use efficiency is low. The selected adaptation measures aimed to increase water availability close to farmland, and increase water use efficiency of farmers and households.

  9. Step-wise addition of disulfide bridge in firefly luciferase controls color shift through a flexible loop: a thermodynamic perspective.

    Science.gov (United States)

    Nazari, Mahboobeh; Hosseinkhani, Saman; Hassani, Leila

    2013-02-01

    Multi-color bioluminescence is developed using the introduction of single/double disulfide bridges in firefly luciferase. The bioluminescence reaction, which uses luciferin, Mg(2+)-ATP and molecular oxygen to yield an electronically excited oxyluciferin, is carried out by the luciferase and emits visible light. The bioluminescence color of firefly luciferases is determined by the luciferase sequence and assay conditions. It has been proposed that the stability of a protein may increase through the introduction of a disulfide bridge that decreases the configurational entropy of unfolding. Single and double disulfide bridges are introduced into Photinus pyralis firefly luciferase to make separate mutant enzymes with a single/double bridge (C(81)-A(105)C, L(306)C-L(309)C, P(451)C-V(469)C; C(81)-A(105)C/P(451)C-V(469)C, and A(296)C-A(326)C/P(451)C-V(469)C). By introduction of disulfide bridges using site-directed mutagenesis in Photinus pyralis luciferase the color of emitted light was changed to red or kept in different extents. The bioluminescence color shift occurred with displacement of a critical loop in the luciferase structure without any change in green emitter mutants. Thermodynamic analysis revealed that among mutants, L(306)C-L(309)C shows a remarkable stability against urea denaturation and also a considerable increase in kinetic stability and a clear shift in bioluminescence spectra towards red.

  10. Influence of breaking the symmetry between disease transmission and information propagation networks on stepwise decisions concerning vaccination

    International Nuclear Information System (INIS)

    Fukuda, Eriko; Tanimoto, Jun; Akimoto, Mitsuhiro

    2015-01-01

    Highlights: • We construct a model using epidemiological and vaccination dynamics. • We study effects of information propagation networks on disease propagation. • Information propagation networks affect the spatial structures of vaccinators. • Disease transmission network affects the information propagation network results. • Vaccination cost does not alter the effects of network-topology symmetry breaking. - Abstract: In previous epidemiological studies that address adaptive vaccination decisions, individuals generally act within a single network, which models the population structure. However, in reality, people are typically members of multiplex networks, which have various community structures. For example, a disease transmission network, which directly transmits infectious diseases, does not necessarily correspond with an information propagation network, in which individuals directly or indirectly exchange information concerning health conditions and vaccination strategies. The latter network may also be used for strategic interaction (strategy adaptation) concerning vaccination. Therefore, in order to reflect this feature, we consider the vaccination dynamics of structured populations whose members simultaneously belong to two types of networks: disease transmission and information propagation. Applying intensive numerical calculations, we determine that if the disease transmission network is modeled using a regular graph, such as a lattice population or random regular graph containing individuals of equivalent degrees, individuals should base their vaccination decisions on a different type of network. However, if the disease transmission network is a degree-heterogeneous graph, such as the Barabási–Albert scale-free network, which has a heterogeneous degree according to power low, then using the same network for information propagation more effectively prevents the spread of epidemics. Furthermore, our conclusions are unaffected by the relative

  11. A perspective of stepwise utilisation of Bayer red mud: Step two—Extracting and recovering Ti from Ti-enriched tailing with acid leaching and precipitate flotation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanfang; Chai, Wencui; Han, Guihong, E-mail: guihong-han@hotmail.com; Wang, Wenjuan; Yang, Shuzhen; Liu, Jiongtian

    2016-04-15

    Highlights: • An integrated process for the stepwise disposal of red mud was proposed. • Extracting and recovering Ti from Ti-enriched tailing was the second step. • The factors influencing acid leaching and precipitate flotation were examined. • The extracting of metals in concentrated H{sub 2}SO{sub 4} was controlled by diffusion reactions. • [Hbet][Tf{sub 2}N] was an effective precipitating reagent with its coordination mechanism. - Abstract: The extraction and recovery of Ti from Ti-enriched tailing with acid leaching and precipitate flotation, as one of the critical steps, was proposed for the stepwise utilization of red mud. The factors influencing acid leaching and precipitate flotation were examined by factorial design. The leaching thermodynamics, kinetics of Ti{sup 4+}, Al{sup 3+} and Fe{sup 3+}, and the mechanism of selectively Fe{sup 3+} removal using [Hbet][Tf{sub 2}N] as precipitating reagent were discussed. The extracting of Ti{sup 4+}, Al{sup 3+} and Fe{sup 3+} in concentrated H{sub 2}SO{sub 4} is controlled by diffusion reactions, depending mainly upon leaching time and temperature. The maximum extracting efficiency of Ti{sup 4+} is approximately 92.3%, whereas Al{sup 3+} and Fe{sup 3+} leaching are respectively 75.8% and 84.2%. [Hbet][Tf{sub 2}N], as a precipitating reagent, operates through a coordination mechanism in flotation. The pH value is the key factor influencing the flotation recovery of Ti{sup 4+}, whereas the dosage of precipitating reagent is that for Al{sup 3+} recovery. The maximum flotation recovery of Ti{sup 4+} is 92.7%, whereas the maximum Al{sup 3+} recovery is 93.5%. The total recovery rate for extracting and recovering titanium is 85.5%. The liquor with Ti{sup 4+} of 15.5 g/L, Al{sup 3+} of 30.4 g/L and Fe{sup 3+} of 0.48 g/L was obtained for the following hydrolysis step in the integrated process for red mud utilisation.

  12. Efficient genetic transformation of Lotus corniculatus L. using a direct shoot regeneration protocol, stepwise hygromycin B selection, and a super-binary Agrobacterium tumefaciens vector

    Directory of Open Access Journals (Sweden)

    Nikolić Radomirka

    2007-01-01

    Full Text Available Cotyledons from 6-day-old Lotus corniculatus cv. Bokor seedlings, transversally cut into two halves, were capa­ble of regenerating buds without intervening callus formation. The explants were co-cultivated with the Agrobacterium tumefaciens LBA4404/pTOK233 superbinary vector carrying the uidA-intron gene and the genes hpt and nptII. They were cultured for 14 days on a regeneration medium, then subjected to a stepwise hygromycin B selection procedure consisting of gradually increasing antibiotic concentrations (5-15 mg L-1 over 21 weeks. Transformed shoots were obtained within 5 months after co-cultivation. Out of 124 initially co-cultivated explants, 52 (42% plants survived hygromycin B selection. The presence of transgenes in regenerated plants was verified by β-glucuronidase histochemical assays and PCR analysis for the presence of uidA gene sequences. Hygromycin B-resistant and PCR-positive T0 plants were cultured in the greenhouse to produce flowers and seeds. The obtained data demonstrate that the reported transformation protocol could be useful for introducing agriculturally important genes into the new L. corniculatus cultivar Bokor.

  13. Organic Analysis of Catalytic Fischer-Tropsch Synthesis Products and Ordinary Chondrite Meteorites by Stepwise Pyrolysis-GCMS: Organics in the Early Solar Nebula

    Science.gov (United States)

    Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

    2014-01-01

    Abiotic generation of complex organic compounds, in the early solar nebula that formed our solar system, is hypothesized by some to occur via Fischer-Tropsch (FT) synthesis. In its simplest form, FT synthesis involves the low temperature (300degC) produces FT products that include lesser amounts of n-alkanes and greater alkene, alcohol, and polycyclic aromatic hydrocarbon (PAH) compounds. We have begun to experimentally investigate FT synthesis in the context of abiotic generation of organic compounds in the early solar nebula. It is generally thought that the early solar nebula included abundant hydrogen and carbon monoxide gases and nano-particulate matter such as iron and metal silicates that could have catalyzed the FT reaction. The effect of FT reaction temperature, catalyst type, and experiment duration on the resulting products is being investigated. These solid organic products are analyzed by thermal-stepwise pyrolysis-GCMS and yield the types and distribution of hydrocarbon compounds released as a function of temperature. We show how the FT products vary by reaction temperature, catalyst type, and experimental duration and compare these products to organic compounds found to be indigenous to ordinary chondrite meteorites. We hypothesize that the origin of organics in some chondritic meteorites, that represent an aggregation of materials from the early solar system, may at least in part be from FT synthesis that occurred in the early solar nebula.

  14. Stepwise Differentiation of Pluripotent Stem Cells into Osteoblasts Using Four Small Molecules under Serum-free and Feeder-free Conditions

    Directory of Open Access Journals (Sweden)

    Kosuke Kanke

    2014-06-01

    Full Text Available Pluripotent stem cells are a promising tool for mechanistic studies of tissue development, drug screening, and cell-based therapies. Here, we report an effective and mass-producing strategy for the stepwise differentiation of mouse embryonic stem cells (mESCs and mouse and human induced pluripotent stem cells (miPSCs and hiPSCs, respectively into osteoblasts using four small molecules (CHIR99021 [CHIR], cyclopamine [Cyc], smoothened agonist [SAG], and a helioxanthin-derivative 4-(4-methoxyphenylpyrido[4′,3′:4,5]thieno[2,3-b]pyridine-2-carboxamide [TH] under serum-free and feeder-free conditions. The strategy, which consists of mesoderm induction, osteoblast induction, and osteoblast maturation phases, significantly induced expressions of osteoblast-related genes and proteins in mESCs, miPSCs, and hiPSCs. In addition, when mESCs defective in runt-related transcription factor 2 (Runx2, a master regulator of osteogenesis, were cultured by the strategy, they molecularly recapitulated osteoblast phenotypes of Runx2 null mice. The present strategy will be a platform for biological and pathological studies of osteoblast development, screening of bone-augmentation drugs, and skeletal regeneration.

  15. Development of an in vitro culture method for stepwise differentiation of mouse embryonic stem cells and induced pluripotent stem cells into mature osteoclasts.

    Science.gov (United States)

    Nishikawa, Keizo; Iwamoto, Yoriko; Ishii, Masaru

    2014-05-01

    The development of methods for differentiation of embryonic stem cells (ESCs) and induced pluripotent stem cell (iPSCs) into functional cells have helped to analyze the mechanism regulating cellular processes and to explore cell-based assays for drug discovery. Although several reports have demonstrated methods for differentiation of mouse ESCs into osteoclast-like cells, it remains unclear whether these methods are applicable for differentiation of iPSCs to osteoclasts. In this study, we developed a simple method for stepwise differentiation of mouse ESCs and iPSCs into bone-resorbing osteoclasts based upon a monoculture approach consisting of three steps. First, based on conventional hanging-drop methods, embryoid bodies (EBs) were produced from mouse ESCs or iPSCs. Second, EBs were cultured in medium supplemented with macrophage colony-stimulating factor (M-CSF), and differentiated to osteoclast precursors, which expressed CD11b. Finally, ESC- or iPSC-derived osteoclast precursors stimulated with receptor activator of nuclear factor-B ligand (RANKL) and M-CSF formed large multinucleated osteoclast-like cells that expressed tartrate-resistant acid phosphatase and were capable of bone resorption. Molecular analysis showed that the expression of osteoclast marker genes such as Nfatc1, Ctsk, and Acp5 are increased in a RANKL-dependent manner. Thus, our procedure is simple and easy and would be helpful for stem cell-based bone research.

  16. Efficient Synthesis of Ethanol from CH4 and Syngas on a Cu-Co/TiO2 Catalyst Using a Stepwise Reactor

    Science.gov (United States)

    Zuo, Zhi-Jun; Peng, Fen; Huang, Wei

    2016-10-01

    Ethanol synthesis from CH4 and syngas on a Cu-Co/TiO2 catalyst is studied using experiments, density functional theory (DFT) and microkinetic modelling. The experimental results indicate that the active sites of ethanol synthesis from CH4 and syngas are Cu and CoO, over which the ethanol selectivity is approximately 98.30% in a continuous stepwise reactor. DFT and microkinetic modelling results show that *CH3 is the most abundant species and can be formed from *CH4 dehydrogenation or through the process of *CO hydrogenation. Next, the insertion of *CO into *CH3 forms *CH3CO. Finally, ethanol is formed through *CH3CO and *CH3COH hydrogenation. According to our results, small particles of metallic Cu and CoO as well as a strongly synergistic effect between metallic Cu and CoO are beneficial for ethanol synthesis from CH4 and syngas on a Cu-Co/TiO2 catalyst.

  17. Step-wise and lineage-specific diversification of plant RNA polymerase genes and origin of the largest plant-specific subunits.

    Science.gov (United States)

    Wang, Yaqiong; Ma, Hong

    2015-09-01

    Proteins often function as complexes, yet little is known about the evolution of dissimilar subunits of complexes. DNA-directed RNA polymerases (RNAPs) are multisubunit complexes, with distinct eukaryotic types for different classes of transcripts. In addition to Pol I-III, common in eukaryotes, plants have Pol IV and V for epigenetic regulation. Some RNAP subunits are specific to one type, whereas other subunits are shared by multiple types. We have conducted extensive phylogenetic and sequence analyses, and have placed RNAP gene duplication events in land plant history, thereby reconstructing the subunit compositions of the novel RNAPs during land plant evolution. We found that Pol IV/V have experienced step-wise duplication and diversification of various subunits, with increasingly distinctive subunit compositions. Also, lineage-specific duplications have further increased RNAP complexity with distinct copies in different plant families and varying divergence for subunits of different RNAPs. Further, the largest subunits of Pol IV/V probably originated from a gene fusion in the ancestral land plants. We propose a framework of plant RNAP evolution, providing an excellent model for protein complex evolution. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  18. Illustration of Step-Wise Latent Class Modeling With Covariates and Taxometric Analysis in Research Probing Children's Mental Models in Learning Sciences.

    Science.gov (United States)

    Stamovlasis, Dimitrios; Papageorgiou, George; Tsitsipis, Georgios; Tsikalas, Themistoklis; Vaiopoulou, Julie

    2018-01-01

    This paper illustrates two psychometric methods, latent class analysis (LCA) and taxometric analysis (TA) using empirical data from research probing children's mental representation in science learning. LCA is used to obtain a typology based on observed variables and to further investigate how the encountered classes might be related to external variables, where the effectiveness of classification process and the unbiased estimations of parameters become the main concern. In the step-wise LCA, the class membership is assigned and subsequently its relationship with covariates is established. This leading-edge modeling approach suffers from severe downward-biased estimations. The illustration of LCA is focused on alternative bias correction approaches and demonstrates the effect of modal and proportional class-membership assignment along with BCH and ML correction procedures. The illustration of LCA is presented with three covariates, which are psychometric variables operationalizing formal reasoning, divergent thinking and field dependence-independence, respectively. Moreover, taxometric analysis, a method designed to detect the type of the latent structural model, categorical or dimensional, is introduced, along with the relevant basic concepts and tools. TA was applied complementarily in the same data sets to answer the fundamental hypothesis about children's naïve knowledge on the matters under study and it comprises an additional asset in building theory which is fundamental for educational practices. Taxometric analysis provided results that were ambiguous as far as the type of the latent structure. This finding initiates further discussion and sets a problematization within this framework rethinking fundamental assumptions and epistemological issues.

  19. Is there a stepwise increase in neonatal morbidities according to histological stage (or grade) of acute chorioamnionitis and funisitis?: effect of gestational age at delivery.

    Science.gov (United States)

    Lee, Yeri; Kim, Hyun-Joo; Choi, Suk-Joo; Oh, Soo-Young; Kim, Jung-Sun; Roh, Cheong-Rae; Kim, Jong-Hwa

    2015-03-01

    To test if there is a stepwise difference in neonatal outcomes according to the stage (or grade) of histological inflammatory response in the chorioamniotic membranes and umbilical cords of preterm premature rupture of membranes (PPROM). This retrospective study included singleton pregnancies diagnosed as PPROM and delivered prior to 34 weeks of gestation (n=339). Acute histological chorioamnionitis and funisitis were subdivided into stages (or grade) as defined by Redline et al. Neonatal composite morbidities and mortality were also monitored. Univariate and multivariate analyses were conducted. Increasing stage (or grade) of acute histological chorioamnionitis and funisitis was significantly associated with an earlier gestational age at membrane rupture and delivery. Among neonatal outcomes, respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), intraventricular hemorrhage, retinopathy of prematurity, and composite morbidity showed incremental incidence according to increased stage (or grade) of acute chorioamnionitis, while periventricular leukomalacia and necrotizing enterocolitis did not. Only RDS, BPD, and composite morbidity showed similar incremental incidences associated with severity of funisitis stage. However, the incremental trends of each neonatal outcome were found to be nonsignificant by multivariate analysis adjusting confounding variables including gestational age at delivery. Higher incidences of neonatal morbidity according to increased stage (or grade) of either acute histological chorioamnionitis or funisitis were due to an earlier gestational age at delivery.

  20. Stepwise evolution of resistance to toxic cardenolides via genetic substitutions in the Na+/K+ -ATPase of milkweed butterflies (lepidoptera: Danaini).

    Science.gov (United States)

    Petschenka, Georg; Fandrich, Steffi; Sander, Nils; Wagschal, Vera; Boppré, Michael; Dobler, Susanne

    2013-09-01

    Despite the monarch butterfly (Danaus plexippus) being famous for its adaptations to the defensive traits of its milkweed host plants, little is known about the macroevolution of these traits. Unlike most other animal species, monarchs are largely insensitive to cardenolides, because their target site, the sodium pump (Na(+)/K(+) -ATPase), has evolved amino acid substitutions that reduce cardenolide binding (so-called target site insensitivity, TSI). Because many, but not all, species of milkweed butterflies (Danaini) are associated with cardenolide-containing host plants, we analyzed 16 species, representing all phylogenetic lineages of milkweed butterflies, for the occurrence of TSI by sequence analyses of the Na(+)/K(+) -ATPase gene and by enzymatic assays with extracted Na(+)/K(+) -ATPase. Here we report that sensitivity to cardenolides was reduced in a stepwise manner during the macroevolution of milkweed butterflies. Strikingly, not all Danaini typically consuming cardenolides showed TSI, but rather TSI was more strongly associated with sequestration of toxic cardenolides. Thus, the interplay between bottom-up selection by plant compounds and top-down selection by natural enemies can explain the evolutionary sequence of adaptations to these toxins. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  1. Preparative separation of sulfur-containing diketopiperazines from marine fungus Cladosporium sp. using high-speed counter-current chromatography in stepwise elution mode.

    Science.gov (United States)

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-09

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  2. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    Directory of Open Access Journals (Sweden)

    Binbin Gu

    2015-01-01

    Full Text Available High-speed counter-current chromatography (HSCCC was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs (including two new compounds cladosporin A (1 and cladosporin B (3, and a known compound haematocin (2 from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v and (2:1:2:1, v/v, in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  3. Reprogramming of cell junction modules during stepwise epithelial to mesenchymal transition and accumulation of malignant features in vitro in a prostate cell model

    International Nuclear Information System (INIS)

    Ke, Xi-song; Li, Wen-cheng; Hovland, Randi; Qu, Yi; Liu, Run-hui; McCormack, Emmet; Thorsen, Frits; Olsen, Jan Roger; Molven, Anders; Kogan-Sakin, Ira; Rotter, Varda; Akslen, Lars A.; Oyan, Anne Margrete; Kalland, Karl-Henning

    2011-01-01

    Epithelial to mesenchymal transition (EMT) is pivotal in tumor metastasis. Our previous work reported an EMT model based on primary prostate epithelial cells (EP156T) which gave rise to cells with mesenchymal phenotype (EPT1) without malignant transformation. To promote prostate cell transformation, cells were maintained in saturation density cultures to select for cells overriding quiescence. Foci formed repeatedly following around 8 weeks in confluent EPT1 monolayers. Only later passage EPT1, but not EP156T cells of any passage, could form foci. Cells isolated from the foci were named EPT2 and formed robust colonies in soft agar, a malignant feature present neither in EP156T nor in EPT1 cells. EPT2 cells showed additional malignant traits in vitro, including higher ability to proliferate following confluence, higher resistance to apoptosis and lower dependence on exogenous growth factors than EP156T and EPT1 cells. Microarray profiling identified gene sets, many of which belong to cell junction modules, that changed expression from EP156T to EPT1 cells and continued to change from EPT1 to EPT2 cells. Our findings provide a novel stepwise cell culture model in which EMT emerges independently of transformation and is associated with subsequent accumulation of malignant features in prostate cells. Reprogramming of cell junction modules is involved in both steps.

  4. Stepwise morphological evolution of the active Yellow River (Huanghe) delta lobe (1976-2013): Dominant roles of riverine discharge and sediment grain size

    Science.gov (United States)

    Wu, Xiao; Bi, Naishuang; Xu, Jingping; Nittrouer, Jeffrey A.; Yang, Zuosheng; Saito, Yoshiki; Wang, Houjie

    2017-09-01

    The presently active Yellow River (Huanghe) delta lobe has been formed since 1976 when the river was artificially diverted. The process and driving forces of morphological evolution of the present delta lobe still remain unclear. Here we examined the stepwise morphological evolution of the active Yellow River delta lobe including both the subaerial and the subaqueous components, and illustrated the critical roles of riverine discharge and sediment grain size in dominating the deltaic evolution. The critical sediment loads for maintaining the delta stability were also calculated from water discharge and sediment load measured at station Lijin, the last gauging station approximately 100 km upstream from the river mouth. The results indicated that the development of active delta lobe including both subaerial and subaqueous components has experienced four sequential stages. During the first stage (1976-1981) after the channel migration, the unchannelized river flow enhanced deposition within the channel and floodplain between Lijin station and the river mouth. Therefore, the critical sediment supply calculated by the river inputs obtained from station Lijin was the highest. However, the actual sediment load at this stage (0.84 Gt/yr) was more than twice of the critical sediment load ( 0.35 Gt/yr) for sustaining the active subaerial area, which favored a rapid seaward progradation of the Yellow River subaerial delta. During the second stage (1981-1996), the engineering-facilitated channelized river flow and the increase in median grain size of suspended sediment delivered to the sea resulted in the critical sediment load for keeping the delta stability deceasing to 0.29 Gt/yr. The active delta lobe still gradually prograded seaward at an accretion rate of 11.9 km2/yr at this stage as the annual sediment load at Lijin station was 0.55 Gt/yr. From 1996 to 2002, the critical sediment load further decreased to 0.15 Gt/yr with the sediment grain size increased to 22.5

  5. Illustration of Step-Wise Latent Class Modeling With Covariates and Taxometric Analysis in Research Probing Children's Mental Models in Learning Sciences

    Directory of Open Access Journals (Sweden)

    Dimitrios Stamovlasis

    2018-04-01

    Full Text Available This paper illustrates two psychometric methods, latent class analysis (LCA and taxometric analysis (TA using empirical data from research probing children's mental representation in science learning. LCA is used to obtain a typology based on observed variables and to further investigate how the encountered classes might be related to external variables, where the effectiveness of classification process and the unbiased estimations of parameters become the main concern. In the step-wise LCA, the class membership is assigned and subsequently its relationship with covariates is established. This leading-edge modeling approach suffers from severe downward-biased estimations. The illustration of LCA is focused on alternative bias correction approaches and demonstrates the effect of modal and proportional class-membership assignment along with BCH and ML correction procedures. The illustration of LCA is presented with three covariates, which are psychometric variables operationalizing formal reasoning, divergent thinking and field dependence-independence, respectively. Moreover, taxometric analysis, a method designed to detect the type of the latent structural model, categorical or dimensional, is introduced, along with the relevant basic concepts and tools. TA was applied complementarily in the same data sets to answer the fundamental hypothesis about children's naïve knowledge on the matters under study and it comprises an additional asset in building theory which is fundamental for educational practices. Taxometric analysis provided results that were ambiguous as far as the type of the latent structure. This finding initiates further discussion and sets a problematization within this framework rethinking fundamental assumptions and epistemological issues.

  6. Does migratory distance affect fuelling in a medium-distance passerine migrant?: results from direct and step-wise simulated magnetic displacements

    Directory of Open Access Journals (Sweden)

    Mihaela Ilieva

    2016-03-01

    Full Text Available In birds, fat accumulation before and during migration has been shown to be endogenously controlled and tuned by, among other factors, the Earth's magnetic field. However, our knowledge about the influence of the geomagnetic field on the fuelling in migrating birds is still limited to just a few nocturnally migrating passerine species. In order to study if variations of the magnetic field can also influence the fuelling of both day- and night-migrating passerines, we caught first-year dunnocks (Prunella modularis and subjected them to three magnetic field conditions simulated by a system of magnetic coils: (1 local geomagnetic field of southern Sweden, (2 magnetic field corresponding to the centre of the expected wintering area, and (3 magnetic field met at the northern limit of the species' breeding distribution. We did not find a difference in mass increase between the birds kept in a local magnetic field and a field resembling their wintering area, irrespectively of the mode of magnetic displacement, i.e. direct or step-wise. However, the dunnocks magnetically displaced north showed a lower rate of fuelling in comparison to the control group, probably due to elevated activity. Compared with previous studies, our results suggest that the fuelling response to magnetic displacements during the migration period is specific to the eco-physiological situation. Future studies need to address if there is an effect of magnetic field manipulation on the level of migratory activity in dunnocks and how widespread the influence of local geomagnetic field parameters is on fuelling decisions in different bird species, which have different migratory strategies, distances and migration history.

  7. Stepwise Mechanism of Temperature-Dependent Coacervation of the Elastin-like Peptide Analogue Dimer, (C(WPGVG)3)2.

    Science.gov (United States)

    Tatsubo, Daiki; Suyama, Keitaro; Miyazaki, Masaya; Maeda, Iori; Nose, Takeru

    2018-03-13

    Elastin-like peptides (ELPs) are distinct, repetitive, hydrophobic sequences, such as (VPGVG) n , that exhibit coacervation, the property of reversible, temperature-dependent self-association and dissociation. ELPs can be found in elastin and have been developed as new scaffold biomaterials. However, the detailed relationship between their amino acid sequences and coacervation properties remains obscure because of the structural flexibility of ELPs. In this study, we synthesized a novel, dimeric ELP analogue (H-C(WPGVG) 3 -NH 2 ) 2 , henceforth abbreviated (CW3)2, and analyzed its self-assembly properties and structural factors as indicators of coacervation. Turbidity measurements showed that (CW3)2 demonstrated coacervation at a concentration much lower than that of its monomeric form and another ELP. In addition, the coacervate held water-soluble dye molecules. Thus, potent and distinct coacervation was obtained with a remarkably short sequence of (CW3)2. Furthermore, fluorescence microscopy, dynamic light scattering, and optical microscopy revealed that the coacervation of (CW3)2 was a stepwise process. The structural factors of (CW3)2 were analyzed by molecular dynamics simulations and circular dichroism spectroscopy. These measurements indicated that helical structures primarily consisting of proline and glycine became more disordered at high temperatures with concurrent, significant exposure of their hydrophobic surfaces. This extreme change in the hydrophobic surface contributes to the potent coacervation observed for (CW3)2. These results provide important insights into more efficient applications of ELPs and their analogues, as well as the coacervation mechanisms of ELP and elastin.

  8. Blood pressure gradients and cardiovascular risk factors in urban and rural populations in Abia State South Eastern Nigeria using the WHO STEPwise approach.

    Science.gov (United States)

    Okpechi, Ikechi Gareth; Chukwuonye, Innocent Ijezie; Tiffin, Nicki; Madukwe, Okechukwu Ojoemelam; Onyeonoro, Ugochukwu Uchenna; Umeizudike, Theophilus Ifeanyichukwu; Ogah, Okechukwu Samuel

    2013-01-01

    Developing countries of sub-Saharan Africa (SSA) face a double burden of non-communicable diseases (NCDs) and communicable diseases. As high blood pressure (BP) is a common global cardiovascular (CV) disorder associated with high morbidity and mortality, the relationship between gradients of BP and other CV risk factors was assessed in Abia State, Nigeria. Using the WHO STEPwise approach to surveillance of chronic disease risk factors, we conducted a population-based cross-sectional survey in Abia state, Nigeria from August 2011 to March 2012. Data collected at various steps included: demographic and behavioral risk factors (Step 1); BP and anthropometric measurements (Step 2), and fasting blood cholesterol and glucose (Step 3). Of the 2983 subjects with complete data for analysis, 52.1% were females and 53.2% were rural dwellers. Overall, the distribution of selected CV disease risk factors was diabetes (3.6%), hypertension (31.4%), cigarette smoking (13.3%), use of smokeless tobacco (4.8%), physical inactivity (64.2%) and being overweight or obese (33.7%). Presence of hypertension, excessive intake of alcohol, smoking (cigarette and smokeless tobacco) and physical inactivity occurred more frequently in males than in females (p<0.05); while low income, lack of any formal education and use of smokeless tobacco were seen more frequently in rural dwellers than in those living in urban areas (p<0.05). The frequency of selected CV risk factors increased as BP was graded from optimal, normal to hypertension; and high BP correlated with age, gender, smokeless tobacco, overweight or obesity, annual income and level of education. Given the high prevalence of hypertension in this part of Nigeria, there is an urgent need to focus on the reduction of preventable CV risk factors we have observed to be associated with hypertension, in order to effectively reduce the burden of NCDs in Africa.

  9. Blood pressure gradients and cardiovascular risk factors in urban and rural populations in Abia State South Eastern Nigeria using the WHO STEPwise approach.

    Directory of Open Access Journals (Sweden)

    Ikechi Gareth Okpechi

    Full Text Available BACKGROUND: Developing countries of sub-Saharan Africa (SSA face a double burden of non-communicable diseases (NCDs and communicable diseases. As high blood pressure (BP is a common global cardiovascular (CV disorder associated with high morbidity and mortality, the relationship between gradients of BP and other CV risk factors was assessed in Abia State, Nigeria. METHODS: Using the WHO STEPwise approach to surveillance of chronic disease risk factors, we conducted a population-based cross-sectional survey in Abia state, Nigeria from August 2011 to March 2012. Data collected at various steps included: demographic and behavioral risk factors (Step 1; BP and anthropometric measurements (Step 2, and fasting blood cholesterol and glucose (Step 3. RESULTS: Of the 2983 subjects with complete data for analysis, 52.1% were females and 53.2% were rural dwellers. Overall, the distribution of selected CV disease risk factors was diabetes (3.6%, hypertension (31.4%, cigarette smoking (13.3%, use of smokeless tobacco (4.8%, physical inactivity (64.2% and being overweight or obese (33.7%. Presence of hypertension, excessive intake of alcohol, smoking (cigarette and smokeless tobacco and physical inactivity occurred more frequently in males than in females (p<0.05; while low income, lack of any formal education and use of smokeless tobacco were seen more frequently in rural dwellers than in those living in urban areas (p<0.05. The frequency of selected CV risk factors increased as BP was graded from optimal, normal to hypertension; and high BP correlated with age, gender, smokeless tobacco, overweight or obesity, annual income and level of education. CONCLUSION: Given the high prevalence of hypertension in this part of Nigeria, there is an urgent need to focus on the reduction of preventable CV risk factors we have observed to be associated with hypertension, in order to effectively reduce the burden of NCDs in Africa.

  10. A perspective of stepwise utilisation of Bayer red mud: Step two--Extracting and recovering Ti from Ti-enriched tailing with acid leaching and precipitate flotation.

    Science.gov (United States)

    Huang, Yanfang; Chai, Wencui; Han, Guihong; Wang, Wenjuan; Yang, Shuzhen; Liu, Jiongtian

    2016-04-15

    The extraction and recovery of Ti from Ti-enriched tailing with acid leaching and precipitate flotation, as one of the critical steps, was proposed for the stepwise utilization of red mud. The factors influencing acid leaching and precipitate flotation were examined by factorial design. The leaching thermodynamics, kinetics of Ti(4+), Al(3+) and Fe(3+), and the mechanism of selectively Fe(3+) removal using [Hbet][Tf2N] as precipitating reagent were discussed. The extracting of Ti(4+), Al(3+) and Fe(3+) in concentrated H2SO4 is controlled by diffusion reactions, depending mainly upon leaching time and temperature. The maximum extracting efficiency of Ti(4+) is approximately 92.3%, whereas Al(3+) and Fe(3+) leaching are respectively 75.8% and 84.2%. [Hbet][Tf2N], as a precipitating reagent, operates through a coordination mechanism in flotation. The pH value is the key factor influencing the flotation recovery of Ti(4+), whereas the dosage of precipitating reagent is that for Al(3+) recovery. The maximum flotation recovery of Ti(4+) is 92.7%, whereas the maximum Al(3+) recovery is 93.5%. The total recovery rate for extracting and recovering titanium is 85.5%. The liquor with Ti(4+) of 15.5g/L, Al(3+) of 30.4g/L and Fe(3+) of 0.48g/L was obtained for the following hydrolysis step in the integrated process for red mud utilisation. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Step-wise assembly, maturation and dynamic behavior of the human CENP-P/O/R/Q/U kinetochore sub-complex.

    Directory of Open Access Journals (Sweden)

    Anja Eskat

    Full Text Available Kinetochores are multi-protein megadalton assemblies that are required for attachment of microtubules to centromeres and, in turn, the segregation of chromosomes in mitosis. Kinetochore assembly is a cell cycle regulated multi-step process. The initial step occurs during interphase and involves loading of the 15-subunit constitutive centromere associated complex (CCAN, which contains a 5-subunit (CENP-P/O/R/Q/U sub-complex. Here we show using a fluorescent three-hybrid (F3H assay and fluorescence resonance energy transfer (FRET in living mammalian cells that CENP-P/O/R/Q/U subunits exist in a tightly packed arrangement that involves multifold protein-protein interactions. This sub-complex is, however, not pre-assembled in the cytoplasm, but rather assembled on kinetochores through the step-wise recruitment of CENP-O/P heterodimers and the CENP-P, -O, -R, -Q and -U single protein units. SNAP-tag experiments and immuno-staining indicate that these loading events occur during S-phase in a manner similar to the nucleosome binding components of the CCAN, CENP-T/W/N. Furthermore, CENP-P/O/R/Q/U binding to the CCAN is largely mediated through interactions with the CENP-N binding protein CENP-L as well as CENP-K. Once assembled, CENP-P/O/R/Q/U exchanges slowly with the free nucleoplasmic pool indicating a low off-rate for individual CENP-P/O/R/Q/U subunits. Surprisingly, we then find that during late S-phase, following the kinetochore-binding step, both CENP-Q and -U but not -R undergo oligomerization. We propose that CENP-P/O/R/Q/U self-assembles on kinetochores with varying stoichiometry and undergoes a pre-mitotic maturation step that could be important for kinetochores switching into the correct conformation necessary for microtubule-attachment.

  12. Verification study on technology for site investigation for geological disposal. Confirmation of the applicability of survey methods through establishing site descriptive models in accordance with stepwise investigation approach

    International Nuclear Information System (INIS)

    Kondo, Hirofumi; Suzuki, Koichi; Hasegawa, Takuma; Hamada, Takaomi; Yoshimura, Kimitaka

    2014-01-01

    The Yokosuka Demonstration and Validation Project, which uses the Yokosuka Central Research Institute of Electric Power Industry (CRIEPI) site, a Neogene sedimentary and coastal environment, has been conducted since the 2006 fiscal year as a cooperative research project between NUMO (Nuclear Waste Management Organization of Japan) and CRIEPI. The objectives of this project were to examine and refine the basic methodology of the investigation and assessment in accordance with the conditions of geological environment at each stage of investigations from the surface (Preliminary Investigation and the first half of Detailed Investigation conducted by NUMO) for high level radioactive waste geological disposal. Within investigation technologies at these early stages, a borehole survey is an important means of directly obtaining various properties of the deep geological environment. On the other hand, surface geophysical prospecting data provide information about the geological and resistivity structures at depth for planning borehole surveys. During the 2006-2009 fiscal years, a series of on-site surveys and tests, including borehole surveys of YDP-1 (depth: 350 m) and YDP-2 (depth: 500 m), were conducted in this test site. Furthermore, seismic surveys (including seismic reflection method) and electromagnetic surveys (including magnetotelluric method) were conducted within the expanded CRIEPI site in the 2010 fiscal year to obtain information about the geological structure, and the resistivity structure reflecting the distribution of the salt water/fresh water boundary, respectively, to a depth of over several hundred meters. The validity of existing survey and testing methods for stepwise investigations (from surface to borehole surveys) for obtaining properties of the geological environment (in various conditions relating to differences in the properties of the Miura and the Hayama Groups at this site) was confirmed through establishing site descriptive models based on

  13. Multiple cardiovascular risk factors in Kenya: evidence from a health and demographic surveillance system using the WHO STEPwise approach to chronic disease risk factor surveillance.

    Science.gov (United States)

    Bloomfield, Gerald S; Mwangi, Ann; Chege, Patrick; Simiyu, Chrispinus J; Aswa, Daniel F; Odhiambo, David; Obala, Andrew A; Ayuo, Paul; Khwa-Otsyula, Barasa O

    2013-09-01

    To describe the distribution of cardiovascular risk factors in western Kenya using a Health and Demographic Surveillance System (HDSS). Population based survey of residents in an HDSS. Webuye Division in Bungoma East District, Western Province of Kenya. 4037 adults ≥ 18 years of age. Home based survey using the WHO STEPwise approach to chronic disease risk factor surveillance. Self-report of high blood pressure, high blood sugar, tobacco use, alcohol use, physical activity, and fruit/vegetable intake. The median age of the population was 35 years (IQR 26-50). Less than 6% of the population reported high blood pressure or blood sugar. Tobacco and alcohol use were reported in 7% and 16% of the population, respectively. The majority of the population (93%) was physically active. The average number of days per week that participants reported intake of fruits (3.1 ± 0.1) or vegetables (1.6 ± 0.1) was low. In multiple logistic regression analyses, women were more likely to report a history of high blood pressure (OR 2.72, 95% CI 1.9 to 3.9), less likely to report using tobacco (OR 0.08, 95% CI 0.06 to 0.11), less likely to report alcohol use (OR 0.18, 95% CI 0.15 to 0.21) or eat ≥ 5 servings per day of fruits or vegetables (OR 0.87, 95% CI 0.76 to 0.99) compared to men. The most common cardiovascular risk factors in peri-urban western Kenya are tobacco use, alcohol use, and inadequate intake of fruits and vegetables. Our data reveal locally relevant subgroup differences that could inform future prevention efforts.

  14. Stepwise metabolic engineering of Gluconobacter oxydans WSH-003 for the direct production of 2-keto-L-gulonic acid from D-sorbitol.

    Science.gov (United States)

    Gao, Lili; Hu, Yudong; Liu, Jie; Du, Guocheng; Zhou, Jingwen; Chen, Jian

    2014-07-01

    2-Keto-L-gulonic acid (2-KLG), the direct precursor of vitamin C, is currently produced by a two-step fermentation route from D-sorbitol. However, this route involves three bacteria, making the mix-culture system complicated and redundant. Thus, replacement of the conventional two-step fermentation process with a one-step process could be revolutionary in vitamin C industry. In this study, different combinations of five L-sorbose dehydrogenases (SDH) and two L-sorbosone dehydrogenases (SNDH) from Ketogulonicigenium vulgare WSH-001 were introduced into Gluconobacter oxydans WSH-003, an industrial strain used for the conversion of d-sorbitol to L-sorbose. The optimum combination produced 4.9g/L of 2-KLG. In addition, 10 different linker peptides were used for the fusion expression of SDH and SNDH in G. oxydans. The best recombinant strain (G. oxydans/pGUC-k0203-GS-k0095) produced 32.4g/L of 2-KLG after 168h. Furthermore, biosynthesis of pyrroloquinoline quinine (PQQ), a cofactor of those dehydrogenases, was enhanced to improve 2-KLG production. With the stepwise metabolic engineering of G. oxydans, the final 2-KLG production was improved to 39.2g/L, which was 8.0-fold higher than that obtained using independent expression of the dehydrogenases. These results bring us closer to the final one-step industrial-scale production of vitamin C. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  15. The cost-effectiveness and budget impact of stepwise addition of bolus insulin in the treatment of type 2 diabetes: evaluation of the FullSTEP trial.

    Science.gov (United States)

    Saunders, Rhodri; Lian, Jean; Karolicki, Boris; Valentine, William

    2014-12-01

    Abstract Background and aims: Intensification of basal insulin-only therapy in type 2 diabetes is often achieved through addition of bolus insulin 3-times daily. The FullSTEP trial demonstrated that stepwise addition (SWA) of bolus insulin aspart was non-inferior to full basal-bolus (FBB) therapy and reduced the rate of hypoglycemia. Here the cost-effectiveness and budget impact of SWA is evaluated. Cost-effectiveness and budget impact models were developed to assess the cost and quality-of-life (QoL) implications of intensification using SWA compared with FBB in the US setting. At assessment, SWA patients added one bolus dose to their current regimen if the HbA1c target was not met. SWA patients reaching three bolus doses used FBB event rates. Outcomes were evaluated at trial end and projected annually up to 5 years. Models captured hypoglycemic events, the proportion meeting HbA1c target, and self-measured blood glucose. Event rates and QoL utilities were taken from trial data and published literature. Costs were evaluated from a healthcare-payer perspective, reported in 2013 USD, and discounted (like clinical outcomes) at 3.5% annually. This analysis applies to patients with HbA1c 7.0-9.0% and body mass index Budget impact analysis estimated that, by moving from FBB to SWA, a health plan with 77,000 patients with type 2 diabetes, of whom 7.8% annually intensified to basal-bolus therapy, would save USD 1304 per intensifying patient over the trial period. SWA of bolus insulin should be considered a beneficial and cost-saving alternative to FBB therapy for the intensification of treatment in type 2 diabetes.

  16. Efficacy and side effects of intravenous remifentanil patient-controlled analgesia used in a stepwise approach for labour: an observational study.

    Science.gov (United States)

    Tveit, T O; Halvorsen, A; Seiler, S; Rosland, J H

    2013-01-01

    Remifentanil has a suitable pharmacological profile for labour analgesia. In this prospective, observational study, intravenous patient-controlled analgesia with remifentanil, using stepwise bolus doses without background infusion, was examined during the first and second stages of labour. Outcomes were pain reduction, maternal satisfaction, maternal and neonatal side effects and remifentanil metabolism in the neonate. Parturients with normal term singleton pregnancies were recruited. The initial remifentanil bolus dose was 0.15 μg/kg, increasing in steps of 0.15 μg/kg, with a 2-min lock-out. Pain scores using a 100 mm visual analogue scale, systolic and diastolic blood pressures, respiratory rate and maternal sedation were recorded every 15 min. Maternal oxygen saturation and heart rate were monitored continuously. Neonatal data included Apgar scores, clinical examination, naloxone use, resuscitation, umbilical cord blood gases and remifentanil concentrations. Forty-one parturients were enrolled. Pain scores were significantly reduced in the first 3 h of patient-controlled analgesia use compared to baseline, and at the end of the first and second stages of labour (Panalgesia. The mean highest dose of remifentanil was 0.7 μg/kg [range 0.3-1.05]. Ninety-three percent of patients were satisfied with their analgesia. The lowest oxygen saturation was 91% and the lowest respiratory rate was 9 breaths/min. Eleven parturients (27%) received supplemental oxygen due to oxygen saturations neonatal data reassuring. Remifentanil intravenous patient-controlled analgesia provides adequate pain relief and high maternal satisfaction during the first and second stages of labour. Maternal sedation and respiratory depression may occur, but no serious neonatal side effects were recorded. Careful monitoring is mandatory. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Determination of Concentration Dependent Diffusion Coefficients of Carbon in Expanded Austenite

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo; Christiansen, Thomas; Somers, Marcel A. J.

    2008-01-01

    Abstract. In the present paper various experimental procedures to experimentally determine the concentration dependent diffusion coefficient of carbon in expanded austenite are evaluated. To this end thermogravimetric carburization was simulated for various experimental conditions and the evaluated...... composition dependent diffusivity of carbon derived from the simulated experiments was compared with the input data. The most promising procedure for an accurate determination is shown to be stepwise gaseous carburizing of thin foils in a gaseous atmosphere; the finer the stepsize, the more accurate...

  18. A step-wise steerable source of illumination for low-noise "Violin-Mode" shadow sensors, intended for use in interferometric gravitational wave detectors

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ˜100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral "Violin-Mode" resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8 × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a "reverse Galilean" telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre's shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre's shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in anti-phase in the

  19. A step-wise steerable source of illumination for low-noise “Violin-Mode” shadow sensors, intended for use in interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ∼100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral “Violin-Mode” resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8  × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a “reverse Galilean” telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre’s shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre’s shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in

  20. Assessing the origin of old apparent ages derived by Pb stepwise leaching of vein-hosted epidote from Mount Isa, northwest Queensland, Australia

    Science.gov (United States)

    Duncan, Robert J.; Maas, Roland

    2014-12-01

    Epidote metasomatism affected large areas of tholeiitic metabasalts of the ~1,780 Ma Eastern Creek Volcanics in the Western Fold Belt of the Proterozoic Mount Isa inlier. Hydrothermal epidote generally occurs in quartz veins parallel to or boudinaged within the dominant S2 fabrics which formed during the regional metamorphic peak at ~1,570 Ma associated with the Isan orogeny. Previously published stable isotopic and halogen data suggest that the fluids responsible for epidote formation are metamorphic in origin (with an evaporitic component). Application of the Pb stepwise leaching technique to the epidote does not separate radiogenic Pb4+ and common Pb2+, generating little spread in 206Pb/204Pb (between 16.0 and 30.5). The causes for this relatively low range are twofold: There is little radiogenic Pb in the epidotes (the most radiogenic steps account for leaching data give ages between 150 and 1,500 myrs older than the host rocks and over 450 myrs older than the thermal metamorphic peak. These old ages are attributed to chemical inheritance from the host metabasalts, via radiogenic Pb release by breakdown of phases such as zircon, monazite, titanomagnetite, and ilmenite during metamorphism. This idea is supported by trace element data and chrondrite-normalized rare earth element patterns that are similar to both the metabasalts and epidotes (except for a variable Eu anomaly in the latter). Relatively high fO2 during vein formation (Fe3+ dominates in the epidote crystal lattice) would allow the incorporation of Th4+ and exclusion of U6+ and would explain elevated Th/U ratios (up to 12) in epidote compared with the host metabasalts. Non-incorporation of U would explain the relatively low U/Pb ratios and non-radiogenic character of the epidote. This process may provide a source of metal for the small U deposits around Mount Isa and may also suggest a relationship between U mineralization and regional Cu mobilization during the Isan orogeny. Our work suggests that

  1. A stepwise approach for introducing numerical modeling in Environmental Engineering MSc unit: The impact of clear assessment criteria and detailed feedback

    Science.gov (United States)

    Rosolem, R.; Pritchard, J.

    2017-12-01

    An important aspect for the new generation of hydrologists and water resources managers is the understanding of hydrological processes through the application of numerical environmental models. Despite its importance, teaching numerical modeling subjects to young students in our MSc Water and Environment Management programme has been difficult, for instance, due to the wide range of student background and lack or poor contact with numerical modeling tools in the past. In previous years, this numerical skills concept has been introduced as a project assignment in our Terrestrial Hydrometeorology unit. However, previous efforts have shown non-optimal engagement by students with often signs of lack of interest or anxiety. Given our initial experience with this unit, we decided to make substantial changes to the coursework format with the aim to introduce a more efficient learning environment to the students. The proposed changes include: (1) a clear presentation and discussion of the assessment criteria at the beginning of the unit, (2) a stepwise approach in which students use our learning environment to acquire knowledge for individual components of the model step-by-step, and (3) access to timely and detailed feedback allowing for particular steps to be retraced or retested. In order to understand the overall impact on assessment and feedback, we carried out two surveys at the beginning and end of the module. Our results indicate a positive impact to student learning experience, as the students have clearly benefited from the early discussion on assignment criteria and appeared to have correctly identified the skills and knowledge required to carry out the assignment. In addition, we have observed a substantial increase in the quality of the reports. Our results results support that student engagement has increased since changes to the format of the coursework were introduced. Interestingly, we also observed a positive impact on the assignment to the final exam

  2. Timing of Hydrocarbon Fluid Emplacement in Sandstone Reservoirs in Neogene in Huizhou Sag, Southern China Sea, by Authigenic Illite 40Ar- 39Ar Laser Stepwise Heating

    Science.gov (United States)

    Hesheng, Shi; Junzhang, Zhu; Huaning, Qiu; yu, Shu; Jianyao, Wu; Zulie, Long

    Timing of oil or gas emplacements is a new subject in isotopic geochronology and petroleum geology. Hamilton et al. expounded the principle of the illite K-Ar age: Illite is often the last or one of the latest mineral cements to form prior to hydrocarbon accumulation. Since the displacement of formation water by hydrocarbons will cause silicate diagenesis to cease, K-Ar ages for illite will constrain the timing of this event, and also constrain the maximum age of formation of the trap structure. In this study, the possibility of authigenic illites 40Ar- 39Ar dating has been investigated. The illite samples were separated from the Tertiary sandstones in three rich oil reservoir belts within the Huizhou sag by cleaning, fracturing by cycled cooling-heating, soxhlet-extraction with solvents of benzene and methanol and separating with centrifugal machine. If oil is present in the separated samples, ionized organic fragments with m/e ratios of 36 to 40 covering the argon isotopes will be yielded by the ion source of a mass spectrometer, resulting in wrong argon isotopic analyses and wrong 40Ar- 39Ar ages. The preliminary experiments of illite by heating did show the presence of ionized organic fragments with m/e ratios of 36 to 44. In order to clean up the organic gases completely and obtain reliable analysis results, a special purification apparatus has been established by Qiu et al. and proved valid by the sequent illite analyses. All the illite samples by 40Ar- 39Ar IR-laser stepwise heating yield stair-up age spectra in lower laser steps and plateaux in higher laser steps. The youngest apparent ages corresponding to the beginning steps are reasonable to be interpreted for the hydrocarbon accumulation ages. The weighted mean ages of the illites from the Zhuhai and Zhujiang Formations are (12.1 ± 1.1) Ma and (9.9 ± 1.2) Ma, respectively. Therefore, the critical emplacement of petroleum accumulation in Zhujiang Formation in Huizhou sag took place in ca 10 Ma. Late

  3. Quantity and quality of food losses along the Swiss potato supply chain: Stepwise investigation and the influence of quality standards on losses.

    Science.gov (United States)

    Willersinn, Christian; Mack, Gabriele; Mouron, Patrik; Keiser, Andreas; Siegrist, Michael

    2015-12-01

    This paper presents the results of a stepwise investigation of the quantity and quality of food losses along the Swiss potato supply chain. Quantitative data were collected from field trials, from structured interviews with wholesalers, processors and retailers, and from consumer surveys in combination with a 30-day diary study. The "Swiss trade customs for potatoes" pose the basis for the qualitative evaluation of losses. The influences of technological, institutional (business and economy; legislation and policy), and social drivers on the generation of fresh potato and processed potato products losses were assessed. Losses due to quality standards driven by food safety and consumer preferences for certain aesthetic standards have been evaluated too. Across the entire potato value chain, approximately 53-55% of the initial fresh potato production and 41-46% of the initial processing potato production are finally lost. Losses between organic and non-organic supply chains differ from 2% to 5%. From the total initial fresh potato production, 15-24% gets lost during agricultural production, a further 12-24% at wholesalers, 1-3% at retailers, and 15% at private households. In comparison, 5-11% of the initial production gets lost at wholesalers, a further 14-15% during processing, 0% at retailers, and 2% at private households. Losses during agricultural production do not vary much (13-25%) between fresh and processing potatoes. Approximately half of total potato losses occur because potatoes do not meet quality standards. 25-34% of these quality-driven losses are caused by food safety reasons, and the remainder are caused by consumer preferences or suitability for storage. In total, social drivers (e.g., consumer preferences, behavior, or socio-demographical factors) are responsible for two-thirds to three-fourths of all fresh potato losses and 40-45% of all processing potato losses. Technological drivers cause circa one-third of the total processing potato losses. The

  4. Nutritional support in the tertiary care of patients affected by chronic renal insufficiency: report of a step-wise, personalized, pragmatic approach.

    Science.gov (United States)

    Cupisti, Adamasco; D'Alessandro, Claudia; Di Iorio, Biagio; Bottai, Anna; Zullo, Claudia; Giannese, Domenico; Barsotti, Massimiliano; Egidi, Maria Francesca

    2016-09-06

    Dietary treatment is helpful in CKD patients, but nutritional interventions are scarcely implemented. The main concern of the renal diets is its feasibility with regards to daily clinical practice especially in the elderly and co-morbid patients. This study aimed to evaluate the effects of a pragmatic, step-wise, personalized nutritional support in the management of CKD patients on tertiary care. This is a case-control study. It included 823 prevalent out-patients affected by CKD stage 3b to 5 not-in-dialysis, followed by tertiary care in nephrology clinics; 305 patients (190 males, aged 70 ± 12 years) received nutritional support (nutritional treatment Group, NTG); 518 patients (281 males, aged 73 ± 13 years) who did not receive any dietary therapy, formed the control group (CG). In the NTG patients the dietary interventions were assigned in order to prevent or correct abnormalities and to maintain a good nutritional status. They included manipulation of sodium, phosphate, energy and protein dietary intakes while paying special attention to each patient's dietary habits. Phosphate and BUN levels were lower in the NTG than in the CG, especially in stage 4 and 5. The prevalence of hyperphosphatemia was lower in the NTG than in CG in stage 5 (13.3 % vs 53.3 %, p < 001, respectively), in stage 4 (4.1 % vs 18.3 % vs, p < 0.001) and stage 3b (2.8 % vs 9.5 % p < 0.05). Serum albumin was higher in NTG than in CG especially in stage 5 . The use of calcium-free intestinal phosphate binders was significantly lower in NTG than in CG (11 % vs 19 % p < 0.01), as well as that of Erythropoiesis stimulating agents (11 % vs 19 %, p < 0.01), and active Vitamin D preparations (13 % vs 21 %, p < 0.01). This case-control study shows the usefulness of a nutritional support in addition to the pharmacological good practice in CKD patients on tertiary care. Lower phosphate and BUN levels are obtained together with maintenance of serum albumin

  5. Development of the scheme of stepwise combustion of coal in the inverter firebox of a power unit of 1000 MW power

    Science.gov (United States)

    Prokhorov, V. B.; Chernov, S. L.; Kirichkov, V. S.

    2017-09-01

    The desire to increase the efficiency of using the heat of burned solid fuel leads to the significant growth of the initial steam parameter at steam-turbine plants. At the maximum temperatures of fresh and secondary steam of 700-720°C, the price of connecting of steam pipelines between the boiler and turbine is up to 20% of the price of a power plant unit, which dictates the necessity to decrease their length. One of the methods to achieve this is the application of an inverter firebox. An M-shaped profile of boiler, allowing one to decrease the length of heat-resistant steam pipelines, was developed at NRU MPEI. A distinctive feature of the profile is two inclined connecting gas flues between the firebox and convective shaft, starting from the gas windows located in the lower third of the firebox height. The boiler was designed for the steam production of 2493 t/h with the parameters of fresh steam of 35 MPa and 710°C. Thermal and aerodynamic calculations made it possible to get the sizes of boiler and dimensions of heating surfaces, and they also allow one to get the values of temperatures in the characteristic points along the gas path. On the basis of the results of calculations, the coefficient of efficiency of the boiler was 93.07% and the fuel consumption was 91.13 kg/s. For this boiler, the technology of effective stepwise burning of coal in a direct-flow-vortex torch (DFVT) in a system of vertical and horizontal tangential torches in the mode of solid slag removal, previously successively used in boilers with a traditional profile and upgraded to an inverter firebox, is proposed. The layouts of the direct-flow burners and nozzles for even and odd vertical sections of the firebox and also in a horizontal section were proposed. Organization of staged air supply in the vertical direction with a high fraction of in-firebox recycle of hot gases leads to low concentration of nitrogen oxides.

  6. Preparative Separation of Phenolic Compounds from Chimonanthus praecox Flowers by High-Speed Counter-Current Chromatography Using a Stepwise Elution Mode

    Directory of Open Access Journals (Sweden)

    Huaizhi Li

    2016-08-01

    Full Text Available High-speed counter-current chromatography (HSCCC has been successfully used for the separation of eight compounds from Chimonanthus praecox flowers. Firstly, the crude extract of Chimonanthus praecox flowers was dissolved in a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–H2O (5:5:3:7, v/v and divided into two parts: the upper phase (part I and the lower phase (part II. Then, HSCCC was applied to separate the phenolic acids from part I and part II, respectively. Considering the broad polarity range of target compounds in part I, a stepwise elution mode was established. Two optimal solvent systems of petroleum ether–ethyl acetate–methanol–H2O–formic acid (FA (5:5:3:7:0.02, 5:5:4.3:5.7:0.02, v/v were employed in this separation. Five phenylpropanoids and two flavonoids were successfully separated from 280 mg of part I, including 8.7 mg of 3,4-dihydroxy benzoic acid (a, 95.3% purity, 10.9 mg of protocatechualdehyde (b, 96.8% purity, 11.3 mg of p-coumaric acid (c, 98.9% purity, 12.2 mg of p-hydroxybenzaldehyde (d, 95.9% purity, 24.7 mg of quercetin (e, 97.3% purity, 33.8 mg of kaempferol (f, 96.8% purity, and 24.6 mg of 4-hydroxylcinnamic aldehyde (g, 98.0% purity. From 300 mg of part II, 65.7 mg of rutin (h, 98.2% purity, 7.5 mg of 3,4-dihydroxy benzoic acid (a, 77.4% purity, and 4.7 mg of protocatechualdehyde (b, 81.6% purity were obtained using the solvent system EtOAc–n-butanol (n-BuOH–FA–H2O (4:1:0.5:5, v/v. The structures of the eight pure compounds were confirmed by electrospray ionization-mass spectrometry (ESI-MS, 1H-NMR and 13C-NMR. To the best of our knowledge, compounds a–d and f were the first separated and reported from the Chimonanthus praecox flower extract.

  7. Unconventional hydrogen bonding to organic ions in the gas phase: Stepwise association of hydrogen cyanide with the pyridine and pyrimidine radical cations and protonated pyridine

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, Ahmed M.; El-Shall, M. Samy, E-mail: mselshal@vcu.edu [Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Hilal, Rifaat; Elroby, Shaaban; Aziz, Saadullah G. [Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2014-08-07

    Equilibrium thermochemical measurements using the ion mobility drift cell technique have been utilized to investigate the binding energies and entropy changes for the stepwise association of HCN molecules with the pyridine and pyrimidine radical cations forming the C{sub 5}H{sub 5}N{sup +·}(HCN){sub n} and C{sub 4}H{sub 4}N{sub 2}{sup +·}(HCN){sub n} clusters, respectively, with n = 1–4. For comparison, the binding of 1–4 HCN molecules to the protonated pyridine C{sub 5}H{sub 5}NH{sup +}(HCN){sub n} has also been investigated. The binding energies of HCN to the pyridine and pyrimidine radical cations are nearly equal (11.4 and 12.0 kcal/mol, respectively) but weaker than the HCN binding to the protonated pyridine (14.0 kcal/mol). The pyridine and pyrimidine radical cations form unconventional carbon-based ionic hydrogen bonds with HCN (CH{sup δ+}⋯NCH). Protonated pyridine forms a stronger ionic hydrogen bond with HCN (NH{sup +}⋯NCH) which can be extended to a linear chain with the clustering of additional HCN molecules (NH{sup +}⋯NCH··NCH⋯NCH) leading to a rapid decrease in the bond strength as the length of the chain increases. The lowest energy structures of the pyridine and pyrimidine radical cation clusters containing 3-4 HCN molecules show a strong tendency for the internal solvation of the radical cation by the HCN molecules where bifurcated structures involving multiple hydrogen bonding sites with the ring hydrogen atoms are formed. The unconventional H-bonds (CH{sup δ+}⋯NCH) formed between the pyridine or the pyrimidine radical cations and HCN molecules (11–12 kcal/mol) are stronger than the similar (CH{sup δ+}⋯NCH) bonds formed between the benzene radical cation and HCN molecules (9 kcal/mol) indicating that the CH{sup δ+} centers in the pyridine and pyrimidine radical cations have more effective charges than in the benzene radical cation.

  8. A step-wise steerable source of illumination for low-noise “Violin-Mode” shadow sensors, intended for use in interferometric gravitational wave detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance), Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2016-01-15

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ∼100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral “Violin-Mode” resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8  × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a “reverse Galilean” telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre’s shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre’s shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in

  9. Benzohydroxamic acid as a reductometric titrant:determination of manganese, chromium and vanadium in steels

    International Nuclear Information System (INIS)

    Ahmed, M.K.; Subbarao, C.

    1981-01-01

    A method has been developed for the rapid determination of manganese and chromium by direct stepwise reductometric titration with benzohydroxamic acid, and of vanadium by titration with ascorbic acid (with benzohydroxamic acid as indicator) in the same aliquot. The method is free from the interference of common alloying elements present in steels. Some BCS steel samples have been analysed with good precision and accuracy. (author)

  10. Acid-base titrations by stepwise addition of equal volumes of titrant with special reference to automatic titrations-III Presentation of a fully automatic titration apparatus and of results supporting the theories given in the preceding parts.

    Science.gov (United States)

    Pehrsson, L; Ingman, F

    1977-02-01

    This paper forms Part III of a series in which the first two parts describe methods for evaluating titrations performed by stepwise addition of equal volumes of titrant. The great advantage of these methods is that they do not require an accurate calibration of the electrode system. This property makes the methods very suitable for routine work. e.g., in automatic analysis. An apparatus for performing such titrations automatically is presented. Further, results of titrations of monoprotic acids, a diprotic acid, an ampholyte, a mixture of an acid with its conjugate base, and mixtures of two acids with a small difference between the stability constants are given. Most of these titrations cannot be evaluated by the Gran or Hofstee methods but yield results having errors of the order of 0.1% if the methods proposed in Parts I and II of this series are employed. The advantages of the method of stepwise addition of equal volumes of titrant combined with the proposed evaluation methods, in comparison with common methods such as titration to a preset pH, are that all the data are used in the evaluation, permitting a statistical treatment and giving better possibilities for tracing systematic errors.

  11. A Stepwise Psychotherapy Intervention for Reducing Risk in Coronary Artery Disease (SPIRR-CAD): Results of an Observer-Blinded, Multicenter, Randomized Trial in Depressed Patients With Coronary Artery Disease.

    Science.gov (United States)

    Herrmann-Lingen, Christoph; Beutel, Manfred E; Bosbach, Alexandra; Deter, Hans-Christian; Fritzsche, Kurt; Hellmich, Martin; Jordan, Jochen; Jünger, Jana; Ladwig, Karl-Heinz; Michal, Matthias; Petrowski, Katja; Pieske, Burkert; Ronel, Joram; Söllner, Wolfgang; Stöhr, Andreas; Weber, Cora; de Zwaan, Martina; Albus, Christian

    2016-01-01

    Depression predicts adverse prognosis in patients with coronary artery disease (CAD), but previous treatment trials yielded mixed results. We tested the hypothesis that stepwise psychotherapy improves depressive symptoms more than simple information. In a multicenter trial, we randomized 570 CAD patients scoring higher than 7 on the Hospital Anxiety and Depression Scale-depression subscale to usual care plus either one information session (UC-IS) or stepwise psychotherapy (UC-PT). UC-PT patients received three individual psychotherapy sessions. Those still depressed were offered group psychotherapy (25 sessions). The primary outcome was changed in the Hospital Anxiety and Depression Scale-depression scores from baseline to 18 months. Preplanned subgroup analyses examined whether treatment responses differed by patients' sex and personality factors (Type D). The mean (standard deviation) depression scores declined from 10.4 (2.5) to 8.7 (4.1) at 18 months in UC-PT and from 10.4 (2.5) to 8.9 (3.9) in UC-IS (both p psychotherapy failed to improve depressive symptoms in CAD patients more than UC-IS. The intervention might be beneficial for depressed CAD patients with Type D personality. However, this finding requires further study. www.clinicaltrials.gov NCT00705965; www.isrctn.com ISRCTN76240576.

  12. Synthesis and characterization of lanthanide picrate complexes with 4-picoline-N-oxide (4-pic N O)

    International Nuclear Information System (INIS)

    Silva, E.M. da.

    1991-01-01

    The lanthanide picrate complexes with 4-picoline-N-oxide were obtained from ethanolic solutions of the hydrated lanthanide picrate and the ligand. The lanthanide content was determined by complexometric titration with EDTA. Carbon, Nitrogen and Hydrogen were determined by microanalytical procedures. Chemical analysis of the lanthanide picrate complexes are also presented. (author)

  13. Analysis of Different Brands of Fruit Juice with Emphasis on their ...

    African Journals Online (AJOL)

    Ten brands of commercial fruit juice were analysed for pH, specific gravity, total solids, reducing sugar, total sugar, and metal contents. The sugar content was determined using the Lane and Eynon method, sodium and potassium were determined by flame photometry, calcium and magnesium by complexometric titration ...

  14. Sex determination based on a thoracic vertebra and ribs evaluation using clinical chest radiography.

    Science.gov (United States)

    Tsubaki, Shun; Morishita, Junji; Usumoto, Yosuke; Sakaguchi, Kyoko; Matsunobu, Yusuke; Kawazoe, Yusuke; Okumura, Miki; Ikeda, Noriaki

    2017-07-01

    Our aim was to investigate whether sex can be determined from a combination of geometric features obtained from the 10th thoracic vertebra, 6th rib, and 7th rib. Six hundred chest radiographs (300 males and 300 females) were randomly selected to include patients of six age groups (20s, 30s, 40s, 50s, 60s, and 70s). Each group included 100 images (50 males and 50 females). A total of 14 features, including 7 lengths, 5 indices for the vertebra, and 2 types of widths for ribs, were utilized and analyzed for sex determination. Dominant features contributing to sex determination were selected by stepwise discriminant analysis after checking the variance inflation factors for multicollinearity. The accuracy of sex determination using a combination of the vertebra and ribs was evaluated from the selected features by the stepwise discriminant analysis. The accuracies in each age group were also evaluated in this study. The accuracy of sex determination based on a combination of features of the vertebra and ribs was 88.8% (533/600). This performance was superior to that of the vertebra or ribs only. Moreover, sex determination of subjects in their 20s demonstrated the highest accuracy (96.0%, 96/100). The features selected in the stepwise discriminant analysis included some features in both the vertebra and ribs. These results indicate the usefulness of combined information obtained from the vertebra and ribs for sex determination. We conclude that a combination of geometric characteristics obtained from the vertebra and ribs could be useful for determining sex. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Sex determination

    Indian Academy of Sciences (India)

    The sex-determining system differs considerably among organisms. Even among insect species, the genetic system for sex-determination is highly diversified. In Drosophila melanogaster, somatic sexual differentiation is regulated by a well characterized genetic hierarchy X : A > Sxl > tra/tra2 > dsx and fru. This cascade ...

  16. Stepwise emergence of azole, echinocandin and amphotericin B multidrug resistance in vivo in Candida albicans orchestrated by multiple genetic alterations

    DEFF Research Database (Denmark)

    Jensen, Rasmus Hare; Thyssen Astvad, Karen Marie; Vale Silva, Luis

    2015-01-01

    -MS were used for sterol analyses. In vivo virulence was determined in the insect model Galleria mellonella and evaluated by log-rank Mantel–Cox tests. Results: P-1 + P-2 were susceptible, P-3 + P-4 fluconazole resistant, P-5 pan-azole resistant, P-6 + P-7 pan-azole and echinocandin resistant and P-8 + P-9...

  17. Author Details

    African Journals Online (AJOL)

    Shetty, P. Vol 59 (2006) - Articles A Simple and Rapid Complexometric Determination of Thallium(III) using Mercaptoethane as Demasking Agent Abstract PDF. ISSN: 0379-4350. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

  18. New Method for Determination of Electrically Inactive Phosphorus in n-type Emitters

    OpenAIRE

    Steyer, Michael; Dastgheib-Shirazi, Amir; Hahn, Giso; Terheiden, Barbara

    2015-01-01

    The precise knowledge of the amount and the location in depth of inactive phosphorus in an n-type emitter is still a challenge. As a new approach, we determine the total amount of phosphorus (P dose) in the emitter stepwise in dependence of etching depth with the characterization tool ICP-OES. A comparison of the data with the electrically active P concentration profile measured by ECV allows to determine in which depths electrically inactive phosphorus is present. For a highly doped emitter,...

  19. Risk determination

    International Nuclear Information System (INIS)

    1993-01-01

    The issue gives a survey of the legal, theological, statistical and health aspects of risk determination. It includes the opinions of physicians, epidemiologists, mathematicians, toxicologists, biologists, theologists and physicists who explain and illustrate the term of risk from their perspective. (orig./DG) [de

  20. Interpretation of complexometric titration data: An intercomparison of methods for estimating models of trace metal complexation by natural organic ligands

    NARCIS (Netherlands)

    Pižeta, I.; Sander, S.G.; Hudson, R.J.M.; Omanovic, D.; Baars, O.; Barbeau, K.A.; Buck, K.N.; Bundy, R.M.; Carrasco, G.; Croot, P.L.; Garnier, C.; Gerringa, L.J.A.; Gledhill, M.; Hirose, K.; Kondo, Y.; Laglera, L.M.; Nuester, J.; Rijkenberg, M.J.A.; Takeda, S.; Twining, B.S.; Wells, M.

    2015-01-01

    With the common goal of more accurately and consistently quantifying ambient concentrations of free metal ions and natural organic ligands in aquatic ecosystems, researchers from 15 laboratories that routinely analyze trace metal speciation participated in an intercomparison of statistical methods

  1. Improving the cycle stability of LiCoPO{sub 4} nanocomposites as 4.8 V cathode: Stepwise or synchronous surface coating and Mn substitution

    Energy Technology Data Exchange (ETDEWEB)

    Örnek, Ahmet, E-mail: ahmetornek@kafkas.edu.tr [Kafkas University, Atatürk Vocational School of Health Science, Kars (Turkey); Can, Mustafa [Sakarya University, Arifiye Vocational School, Sakarya (Turkey); Yeşildağ, Ali [Kafkas University, Faculty of Engineering and Architecture, Department of Bioengineering, Kars (Turkey)

    2016-06-15

    Nanostructured LiCo{sub 1−x}Mn{sub x}PO{sub 4}/C (x = 0 and 0.05) materials were successfully produced as superior quality cathodes by combined sol-gel and carbothermal reduction methods. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), energy dispersive spectroscopy (EDS), fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP), cyclic voltammetry (CV) and galvanostatic measurements were applied to determine the phase purity, morphology and electrochemical qualifications. HR-TEM analysis reveals that the thickness of the surface carbon layer of 5 to 10 nm range with the uniform distribution. LiCo{sub 0·95}Mn{sub 0·05}PO{sub 4}/C particles were between 40 and 80 nm and the same material exhibits a higher and stable reversible capacity (140 mA h g{sup −1}) with the long voltage plateau (4.76 V). Substitution of Co{sup 2+} with Mn{sup 2+} in LiCoPO{sub 4}/C has an influence on the initial discharge capacity and excellent cycling behaviour. The obtained results have attributed that production dynamics in nano-synthesis, the coating process with proper carbon source and an effective doping represent three parameters to prepare favorable cathode materials. - Highlights: • Structural, morphological and electrochemical effects of Mn doped LiCo{sub 1−x}Mn{sub x}PO{sub 4}–C electrodes are investigated. • Cheap, effective and simple sol-gel assisted carbothermal reduction approach is used. • After 60th cycle, capacity retention is almost 92% for LiCo{sub 0·95}Mn{sub 0.05}PO{sub 4}–C electrode. • Mn-doped sample exhibits distinctive oxidation (4.76 V and 4.12 V) peaks.

  2. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko

    1994-01-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.)

  3. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    Energy Technology Data Exchange (ETDEWEB)

    Koshikawa, Tomihiko [Japan Radioisotope Association, Shiga (Japan). Koka Laboratory

    1994-12-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.).

  4. A stepwise algorithm using an at-a-glance first-line test for the non-invasive diagnosis of advanced liver fibrosis and cirrhosis.

    Science.gov (United States)

    Boursier, Jérôme; de Ledinghen, Victor; Leroy, Vincent; Anty, Rodolphe; Francque, Sven; Salmon, Dominique; Lannes, Adrien; Bertrais, Sandrine; Oberti, Frederic; Fouchard-Hubert, Isabelle; Calès, Paul

    2017-06-01

    Chronic liver diseases (CLD) are common, and are therefore mainly managed by non-hepatologists. These physicians lack access to the best non-invasive tests of liver fibrosis, and consequently cannot accurately determine the disease severity. Referral to a hepatologist is then needed. We aimed to implement an algorithm, comprising a new first-line test usable by all physicians, for the detection of advanced liver fibrosis in all CLD patients. Diagnostic study: 3754 CLD patients with liver biopsy were 2:1 randomized into derivation and validation sets. Prognostic study: longitudinal follow-up of 1275 CLD patients with baseline fibrosis tests. Diagnostic study: the easy liver fibrosis test (eLIFT), an "at-a-glance" sum of points attributed to age, gender, gamma-glutamyl transferase, aspartate aminotransferase (AST), platelets and prothrombin time, was developed for the diagnosis of advanced fibrosis. In the validation set, eLIFT and fibrosis-4 (FIB4) had the same sensitivity (78.0% vs. 76.6%, p=0.470) but eLIFT gave fewer false positive results, especially in patients ≥60years old (53.8% vs. 82.0%, ptest. FibroMeter with vibration controlled transient elastography (VCTE) was the most accurate among the eight fibrosis tests evaluated. The sensitivity of the eLIFT-FM VCTE algorithm (first-line eLIFT, second-line FibroMeter VCTE ) was 76.1% for advanced fibrosis and 92.1% for cirrhosis. Prognostic study: patients diagnosed as having "no/mild fibrosis" by the algorithm had excellent liver-related prognosis with thus no need for referral to a hepatologist. The eLIFT-FM VCTE algorithm extends the detection of advanced liver fibrosis to all CLD patients and reduces unnecessary referrals of patients without significant CLD to hepatologists. Blood fibrosis tests and transient elastography accurately diagnose advanced liver fibrosis in the large population of patients having chronic liver disease, but these non-invasive tests are only currently available in specialized

  5. Characteristics of images of angiographically proven normal coronary arteries acquired by adenosine-stress thallium-201 myocardial perfusion SPECT/CT-IQ[Symbol: see text]SPECT with CT attenuation correction changed stepwise.

    Science.gov (United States)

    Takahashi, Teruyuki; Tanaka, Haruki; Kozono, Nami; Tanakamaru, Yoshiki; Idei, Naomi; Ohashi, Norihiko; Ohtsubo, Hideki; Okada, Takenori; Yasunobu, Yuji; Kaseda, Shunichi

    2015-04-01

    Although several studies have shown the diagnostic and prognostic value of CT-based attenuation correction (AC) of single photon emission computed tomography (SPECT) images for diagnosing coronary artery disease (CAD), this issue remains a matter of debate. To clarify the characteristics of CT-AC SPECT images that might potentially improve diagnostic performance, we analyzed images acquired using adenosine-stress thallium-201 myocardial perfusion SPECT/CT equipped with IQ[Symbol: see text]SPECT (SPECT/CT-IQ[Symbol: see text]SPECT) from patients with angiographically proven normal coronary arteries after changing the CT attenuation correction (CT-AC) in a stepwise manner. We enrolled 72 patients (Male 36, Female 36) with normal coronary arteries according to findings of invasive coronary angiography or CT-angiography within three months after a SPECT/CT study. Projection images were reconstructed at CT-AC values of (-), 40, 60, 80 and 100 % using a CT number conversion program according to our definition and analyzed using polar maps according to sex. CT attenuation corrected segments were located from the mid- and apical-inferior spread through the mid- and apical-septal regions and finally to the basal-anterior and basal- and mid-lateral regions in males, and from the mid-inferior region through the mid-septal and mid-anterior, and mid-lateral regions in females as the CT-AC values increased. Segments with maximal mean counts shifted from the apical-anterior to mid-anterolateral region under both stress and rest conditions in males, whereas such segments shifted from the apical-septal to the mid-anteroseptal region under both stress and rest conditions in females. We clarified which part of the myocardium and to which degree CT-AC affects it in adenosine-stress thallium-201 myocardial perfusion SPECT/CT-IQ[Symbol: see text]SPECT images by changing the CT-AC value stepwise. We also identified sex-specific shifts of segments with maximal mean counts that changed as

  6. Controlling methicillin-resistant Staphylococcus aureus by stepwise implementation of preventive strategies in a university hospital: impact of a link-nurse system on the basis of multidisciplinary approaches.

    Science.gov (United States)

    Miyachi, Hayato; Furuya, Hiroyuki; Umezawa, Kazuo; Itoh, Yumiko; Ohshima, Toshio; Miyamoto, Motoaki; Asai, Satomi

    2007-03-01

    Current approaches in the control of methicillin-resistant Staphylococcus aureus (MRSA) in the large tertiary referral hospital have not been universally successful. The trend of MRSA rates and their relationship with stepwise implementation of preventive strategies in Tokai University Hospital during a 76-month period from September 1998 to December 2004, was retrospectively analyzed with a quasi-experimental design. Implementation of strategies including a feedback process with case and epidemic reporting, an infection control team and office, and a preventive guideline for MRSA did not result in reduction in monthly MRSA rates in the hospital, as analyzed with Shewhart u charts. When infection control link nurses were organized and their activities became full-scale, there appeared significant reduction in arithmetic mean of the monthly rates of MRSA from 6.3% to 5.0% in June 2002. Meanwhile the mean values for monthly counts of new MRSA cases also dropped in 15 of 25 wards/units in June 2002, as analyzed with Exponentially Weighted Moving Average charts. Concurrently, there was a significant increase (17.3%) in the monthly consumption of handwashing liquid plain soap. Thereafter the MRSA rates remained low for 2 years within three standard deviations. The sustained reduction of MRSA rates in the hospital can be related to introduction of the infection control link-nurse system on the basis of continuous enforcement of basic and multidisciplinary approaches such as hand-hygiene compliance.

  7. Specificity in endoplasmic reticulum-stress signaling in yeast entails a step-wise engagement of HAC1 mRNA to clusters of the stress sensor Ire1.

    Science.gov (United States)

    van Anken, Eelco; Pincus, David; Coyle, Scott; Aragón, Tomás; Osman, Christof; Lari, Federica; Gómez Puerta, Silvia; Korennykh, Alexei V; Walter, Peter

    2014-12-30

    Insufficient protein-folding capacity in the endoplasmic reticulum (ER) induces the unfolded protein response (UPR). In the ER lumen, accumulation of unfolded proteins activates the transmembrane ER-stress sensor Ire1 and drives its oligomerization. In the cytosol, Ire1 recruits HAC1 mRNA, mediating its non-conventional splicing. The spliced mRNA is translated into Hac1, the key transcription activator of UPR target genes that mitigate ER-stress. In this study, we report that oligomeric assembly of the ER-lumenal domain is sufficient to drive Ire1 clustering. Clustering facilitates Ire1's cytosolic oligomeric assembly and HAC1 mRNA docking onto a positively charged motif in Ire1's cytosolic linker domain that tethers the kinase/RNase to the transmembrane domain. By the use of a synthetic bypass, we demonstrate that mRNA docking per se is a pre-requisite for initiating Ire1's RNase activity and, hence, splicing. We posit that such step-wise engagement between Ire1 and its mRNA substrate contributes to selectivity and efficiency in UPR signaling.

  8. Ring opening of 2-aza-3-borabicyclo[2.2.0]hex-5-ene, the Dewar form of 1,2-dihydro-1,2-azaborine: stepwise versus concerted mechanisms

    Directory of Open Access Journals (Sweden)

    Holger F. Bettinger

    2013-04-01

    Full Text Available The ring opening of the Dewar form of 1,2-dihydro-1,2-azaborine, 2-aza-3-borabicyclo[2.2.0]hex-5-ene (3 is investigated by theoretical methods by using multiconfiguration SCF (CASSCF and coupled cluster theory [CCSD(T] with basis sets up to polarised quadruple-zeta quality. The title compound was previously reported to form photochemically in cryogenic noble gas matrices from 1,2-dihydro-1,2-azaborine (4. Four reaction paths for the thermal ring opening of 3 to 4 could be identified. These are the conventional disrotatory and conrotatory electrocyclic ring-opening pathways where the BN unit is only a bystander. Two more favourable paths are stepwise and involve 1,3-boron–carbon interactions. The lowest energy barrier for the isomerisation reaction, 22 kcal mol−1, should be high enough for an experimental observation in solution. However, in solution the dimerisation of 3 is computed to have a very low barrier (3 kcal mol−1, and thus 3 is expected to be a short-lived reactive intermediate.

  9. Experiments for quick and accurate thorium assay by means of potentiometric end point determination

    International Nuclear Information System (INIS)

    Mainka, E.; Coerdt, W.

    1978-10-01

    Two methods are described which allow quick thorium assay easily to be automated. In the potentiometric titration with NaF the ion sensitive fluoride electrode is used as the indicator. The analysis can be performed for pH values 3 to 4. Th(OH) 4 precipitation must be avoided although the acidity of the solution must not be too high since otherwise erroneous measurements will be obtained. In the complexometric thorium assay EDTA is used for titration and the indicator is the copper sensitive electrode. This method offers the advantage that the analysis can be performed in the presence of large amounts of uranium, which is excluded under the NaF method. (orig.) [de

  10. Principles of Developing Multi-Pesticide Methods Based on HPLC Determination

    Energy Technology Data Exchange (ETDEWEB)

    Dudar, E. [Plant Protection & Soil Conservation Service of Budapest, Budapest (Hungary)

    2009-07-15

    Principles for the development of multi-pesticide methods based on HPLC determination are outlined. Flow charts and block diagrams give guidance on how to proceed stepwise in the set-up of respective analytical methods. Detailed information is provided on what to take into consideration for setting up a pesticide formulation analysis method. HPLC variables like the types of column, solvents and their strength, pH value, eluent modifiers, column temperature, etc, and the influence on the separation and resolution of chromatographic peaks are discussed as well as the necessity and benefits of internal standardization. Examples of system suitability testing experiments are given for illustration. (author)

  11. Stepwise Approach to Accessible MOOC Development.

    Science.gov (United States)

    Draffan, E A; Wald, Mike; Dickens, Kate; Zimmermann, Gottfried; Kelle, Sebastian; Miesenberger, Klaus; Petz, Andrea

    2015-01-01

    Developing resources for online learning in its many guises and more recently for MOOCs has been discussed across the educational sector, usually by individuals working for one institution or organisation. Rarely are there discussions that highlight the issues of collaborative working on content that is delivered over a period of weeks for a wide range of abilities and skills. In particular there is a reluctance to face the issues presented by barriers to access for those with disabilities and even the issues that could arise should an academic be unable to access the development platform to present content. This paper aims to approach these issues by providing guidance in a series of practical steps that highlight an inclusive design approach.

  12. Stepwise excavation in a permanent molar

    DEFF Research Database (Denmark)

    Lima, Fernanda Ferruzzi; Pascotto, Renata Corrêa; Benetti, Ana Raquel

    2010-01-01

    with zinc oxide cement were performed to minimize the risk of pulp exposure during excavation. After 45 days, the remaining carious tissue was removed and a restoration with glass-ionomer lining (Vitrebond) and resin composite (P-50) was performed. Satisfactory morphology and function of the restoration...

  13. Re-Os, Sm-Nd, U-Pb, and stepwise lead leaching isotope systematics in shear-zone hosted gold mineralization: genetic tracing and age constraints of crustal hydrothermal activity

    Science.gov (United States)

    Frei, R.; Nägler, Th. F.; Schönberg, R.; Kramers, J. D.

    1998-06-01

    A combined Re-Os, Sm-Nd, U-Pb, and stepwise Pb leaching (PbSL) isotope study of hydrothermal (Mo-W)-bearing minerals and base metal sulfides from two adjacent shear zone hosted gold deposits (RAN, Kimberley) in the Harare-Shamva greenstone belt (Zimbabwe) constrain the timing of the mineralizing events to two periods. During an initial Late Archean event (2.60 Ga) a first molybdenite-scheelite bearing paragenesis was deposited in both shear zone systems, followed by a local reactivation of the shear systems during an Early Proterozoic (1.96 Ga) tectono-thermal overprint, during which base metal sulfides and most of the gold was (re-)deposited. While PbSL has revealed an open-system behavior of the U-Pb systematics in molybdenite and wolframite from the RAN mine, initial Archean Re-Os ages are still preserved implying that this system in these minerals was more resistant to the overprint. A similar retentivity could be shown for the Sm-Nd system in scheelite and powellite associated with the above ore minerals. Re-Os isotopic data from the Proterozoic mineralization in the Kimberley mine point to a recent gain of Re, most pronouncedly affecting Fe-rich sulfides such as pyrrhotite. A significant Re-loss in powellitic scheelite (an alteration phase of molybdenite-bearing scheelite), coupled with a marked loss of U in W-Mo ore minerals, complements the observation of a major Re uptake in Fe-sulfides during oxidizing conditions in a weathering environment. Pyrrhotite under these conditions behaves as an efficient Re-sink. Lead isotope signatures from PbSL residues of molybdenite, powellite, and quartz indicate a continental crustal source and/or contamination for the mineralizing fluid by interaction of the fluids with older sedimentary material as represented by the direct host country rocks. Our investigation reveals the potential of the Re-Os isotopic system applied to crustal hydrothermal ore minerals for genetic tracing and dating purposes. The simplified chemical

  14. Stepwise strategy to improve Cervical Cancer Screening Adherence (SCAN-CC): automated text messages, phone calls and face-to-face interviews: protocol of a population-based randomised controlled trial.

    Science.gov (United States)

    Firmino-Machado, João; Mendes, Romeu; Moreira, Amélia; Lunet, Nuno

    2017-10-05

    Screening is highly effective for cervical cancer prevention and control. Population-based screening programmes are widely implemented in high-income countries, although adherence is often low. In Portugal, just over half of the women adhere to cervical cancer screening, contributing for greater mortality rates than in other European countries. The most effective adherence raising strategies are based on patient reminders, small/mass media and face-to-face educational programmes, but sequential interventions targeting the general population have seldom been evaluated. The aim of this study is to assess the effectiveness of a stepwise approach, with increasing complexity and cost, to improve adherence to organised cervical cancer screening: step 1a-customised text message invitation; step 1b-customised automated phone call invitation; step 2-secretary phone call; step 3-family health professional phone call and face-to-face appointment. A population-based randomised controlled trial will be implemented in Portuguese urban and rural areas. Women eligible for cervical cancer screening will be randomised (1:1) to intervention and control. In the intervention group, women will be invited for screening through text messages, automated phone calls, manual phone calls and health professional appointments, to be applied sequentially to participants remaining non-adherent after each step. Control will be the standard of care (written letter). The primary outcome is the proportion of women adherent to screening after step 1 or sequences of steps from 1 to 3. The secondary outcomes are: proportion of women screened after each step (1a, 2 and 3); proportion of text messages/phone calls delivered; proportion of women previously screened in a private health institution who change to organised screening. The intervention and control groups will be compared based on intention-to-treat and per-protocol analyses. The study was approved by the Ethics Committee of the Northern Health

  15. A systemic study of stepwise chlorination-chemical vapor transport characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by alkaline chlorides as complex former

    International Nuclear Information System (INIS)

    Sun Yanhui; He Peng; Chen Huani

    2007-01-01

    A systematic study has been carried out for the stepwise chlorination-chemical vapor transport (SC-CVT) characteristics of pure rare earth oxides from Sc 2 O 3 to Lu 2 O 3 mediated by the vapor complexes KLnCl 4 and NaLnCl 4 (Ln = Sc, Y and La-Lu) used NaCl and KCl as complex former, respectively. The results showed that the SC-CVT characteristics are similarly for NaCl and KCl as complex former, the main deposition temperature of the rare earth chlorides LnCl 3 is in the increasing order ScCl 3 3 3 , and then with a systematically decreasing trend from the early lanthanide chlorides to the end one. The results also showed that the total transported amount of the produced chlorides is YCl 3 > ScCl 3 , and they are much higher than that of most lanthanoid chlorides. For lanthanoids, the total transported amount of chloride increases systematically from the early lanthanoid chlorides to the end one except for EuCl 3 and GdCl 3 mediated by KCl and NaCl as complex former, respectively, which showed the divergence effect of Gd in the total transport efficiency. But there are some differences in SC-CVT characteristics of pure rare earth oxide mediated by KCl and NaCl as complex former, that is the main deposition temperature region for the same rare earth element was lower for KCl than that for NaCl as complex former except for LaCl 3 , CeCl 3 , YbCl 3 and LuCl 3 , while the total transport amount of rare earth chloride for KCl as complex former is higher than that for NaCl except for LaCl 3 and EuCl 3 . More over, the discussion was carried out for Sc and Y on the one hand and the lanthanides contain 4f electron as another hand based on the 4f electron hybridization assumption. Further more, the transport characteristics of rare earth oxides with alkaline chlorides as complex former in this study were compared to that with AlCl 3 as complex former

  16. Healthcare- and Community-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) and Fatal Pneumonia with Pediatric Deaths in Krasnoyarsk, Siberian Russia: Unique MRSA's Multiple Virulence Factors, Genome, and Stepwise Evolution

    Science.gov (United States)

    Khokhlova, Olga E.; Hung, Wei-Chun; Wan, Tsai-Wen; Iwao, Yasuhisa; Takano, Tomomi; Higuchi, Wataru; Yachenko, Svetlana V.; Teplyakova, Olga V.; Kamshilova, Vera V.; Kotlovsky, Yuri V.; Nishiyama, Akihito; Reva, Ivan V.; Sidorenko, Sergey V.; Peryanova, Olga V.; Reva, Galina V.; Teng, Lee-Jene; Salmina, Alla B.; Yamamoto, Tatsuo

    2015-01-01

    239Kras, a new (Siberian Russian) clade of the ST239 lineage, which was created through stepwise evolution during its potential transmission route of Brazil-Europe-Russia/Krasnoyarsk, thereby selective advantages from unique MVFs and the MDR. PMID:26047024

  17. Determination of the Factors Influencing Store Preference in Erzurum by a Multinomial Logit Model

    Directory of Open Access Journals (Sweden)

    Hüseyin ÖZER

    2008-12-01

    Full Text Available The main objective of this study is to determine factors influencing store preference of the store costumers in Erzurum in terms of some characteristics of the store and its product and costumers’ demographic characteristics (sex, age, marital status, level of education and their income level. In order to carry out this objective, Pearson chi-square test is applied to determine whether there is a relationship between the store preference and customer, stores, and some characteristics of products and a multinominal logit model is fitted by stepwise regression method to the cross-section data compiled from a questionnaire applied to 384 store costumers in the center of Erzurum province. According to the model estimation and test results, the variables of marital status (married, education (primary and cheapness (unimportant for Migros; education (middle for Özmar and marital status (married for the other stores are determined as statistically significant at the level of 5 percent

  18. Spectrophotometric titration of zirconium in siliceous materials

    International Nuclear Information System (INIS)

    Sugawara, K.F.; Su, Y.-S.; Strzegowski, W.R.

    1978-01-01

    An accurate and selective complexometric titration procedure based upon a spectrophotometrically detected end-point has been developed for the determination of zirconium in glasses, glass-ceramics and refractories. A p-bromomandelic acid separation step for zirconium imparts excellent selectivity to the procedure. The method is particularly important for the 1 to 5% concentration range where a simple, accurate and selective method for the determination of zirconium has been lacking. (author)

  19. [An examination of the determinants of social withdrawal and affinity for social withdrawal].

    Science.gov (United States)

    Watanabe, Asami; Matsui, Yutaka; Takatsuka, Yusuke

    2010-12-01

    This study examined the determinants of social withdrawal using data from a survey by the Tokyo Metropolitan Government Office for Youth Affairs and Public Safety (2008). In addition, this study identified young people who showed an affinity for social withdrawal although they were not in a state of withdrawal, and examined the determinants of an affinity for social withdrawal. The results of stepwise discriminant analysis showed that factors such as social phobia, depression, violence, and emotional bonds with family differentiated between the general youth group and the social withdrawal group and the "affinity group". Social phobia, violence, and refusal to be interfered in self-decision making differentiated between the social withdrawal group and the "affinity group". This study shows that an "affinity group" should be cared as well as an actual withdrawal group.

  20. Determinants of brain-derived neurotrophic factor (BDNF) in umbilical cord and maternal serum.

    Science.gov (United States)

    Flöck, A; Weber, S K; Ferrari, N; Fietz, C; Graf, C; Fimmers, R; Gembruch, U; Merz, W M

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) plays a fundamental role in brain development; additionally, it is involved in various aspects of cerebral function, including neurodegenerative and psychiatric diseases. Involvement of BDNF in parturition has not been investigated. The aim of our study was to analyze determinants of umbilical cord BDNF (UC-BDNF) concentrations of healthy, term newborns and their respective mothers. This cross-sectional prospective study was performed at a tertiary referral center. Maternal venous blood samples were taken on admission to labor ward; newborn venous blood samples were drawn from the umbilical cord (UC), before delivery of the placenta. Analysis was performed with a commercially available immunoassay. Univariate analyses and stepwise multivariate regression models were applied. 120 patients were recruited. UC-BDNF levels were lower than maternal serum concentrations (median 641 ng/mL, IQR 506 vs. median 780 ng/mL, IQR 602). Correlation between UC- and maternal BDNF was low (R=0.251, p=0.01). In univariate analysis, mode of delivery (MoD), gestational age (GA), body mass index at delivery, and gestational diabetes were determinants of UC-BDNF (MoD and smoking for maternal BDNF, respectively). Stepwise multivariate regression analysis revealed a model with MoD and GA as determinants for UC-BDNF (MoD for maternal BDNF). MoD and GA at delivery are determinants of circulating BDNF in the mother and newborn. We hypothesize that BDNF, like other neuroendocrine factors, is involved in the neuroendocrine cascade of delivery. Timing and mode of delivery may exert BDNF-induced effects on the cerebral function of newborns and their mothers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Position automatic determination technology

    International Nuclear Information System (INIS)

    1985-10-01

    This book tells of method of position determination and characteristic, control method of position determination and point of design, point of sensor choice for position detector, position determination of digital control system, application of clutch break in high frequency position determination, automation technique of position determination, position determination by electromagnetic clutch and break, air cylinder, cam and solenoid, stop position control of automatic guide vehicle, stacker crane and automatic transfer control.

  2. Uranium determinations by 133Xe in terrestrial zircon, apatite and chromite; comparative study of thermal releases of fissiogenic xenon from terrestrial and meteoritic minerals

    International Nuclear Information System (INIS)

    Sakamoto, K.; Hamajima, Y.; Itoh, K.; Yamazaki, K.

    1980-01-01

    Terrestrial zircon and apatite, as examples of uranium rich refractory minerals, and chromite, also highly refractory but uranium poor, were neutron-irradiated for their 133 Xe release studies. Uranium determination by 133 Xe was found not to be successful in these refractory samples, due to incomplete fissiogenic-xenon release at 1600 deg C as revealed by stepwise heating experiment. In these terrestrial materials the high temperature release peaks appeared at >=1500 deg C, but in meteoritic whitlockite and chromite values of 1000 approximately 1200 deg C were reported. (author)

  3. Toughness determination of zirconia toughened alumina ceramics from growth of indentation-induced cracks

    International Nuclear Information System (INIS)

    Basu, D.; Sarkar, B.K.

    1996-01-01

    Short surface cracks were generated by Vickers indentation on the polished surface of alumina and different zirconia toughened alumina (ZTA) specimens, and their morphology was studied by serial sectioning. These cracks were grown in three-point bend tests under stepwise loading, and variation of toughness with crack extension was plotted to graphically separate the contributions from residual stress intensity and applied stress intensity factors. The plateau toughness determined from the intercept height of the crack extension plots exhibited an upward trend with zirconia content up to 15 vol% ZrO 2 addition in the composition, which was proportional to the fraction of transformable tetragonal grains contributing to transformation toughening. copyright 1996 Materials Research Society

  4. Determinants of exercise among children. II. A longitudinal analysis.

    Science.gov (United States)

    DiLorenzo, T M; Stucky-Ropp, R C; Vander Wal, J S; Gotham, H J

    1998-01-01

    Research has demonstrated that physical activity serves an important preventive function against the development of cardiovascular disease. The recognition that U.S. children are often sedentary, coupled with the observation that physical activity habits tend to persist into adulthood, has prompted the investigation of exercise determinants consistent with social learning theory. The purposes of the present study were to identify social learning variables relevant to children's exercise and to explore the longitudinal predictive value of the determinants. Data were collected from 111 families (N = 54 girls, N = 57 boys) who were interviewed in both Phase 1 (fifth and sixth grades) and Phase 2 (eight and ninth grades) of this study. Data from mothers (N = 111) were collected during both phases; data from 80 fathers were collected at Phase 2 only. The results of simultaneous stepwise regression analyses indicated that child's enjoyment of physical activity was the only consistent predictor of physical activity during Phase 1. At Phase 2, child's exercise knowledge, mother's physical activity, and child's and mother's friend modeling/support emerged as predictors for girls. For boys, child's self-efficacy for physical activity, exercise knowledge, parental modeling, and interest in sports media were important. Longitudinally, mother's self-efficacy, barriers to exercise, enjoyment of physical activity, and child's self-efficacy for physical activity were important for girls. Only child's exercise knowledge predicted boys' physical activity. The addition of information from fathers nearly doubled the explanatory power of the predictors for both genders. Socialization in the family unit exerts a tremendous influence on health-related behaviors such as exercise. The relative importance of determinants seems to differ for girls and boys and the pattern of these determinants appears to change over time.

  5. Determination of trace elements by resonant ionization mass spectrometry (RIMS)

    International Nuclear Information System (INIS)

    Ruster, W.; Ames, F.; Rehklau, D.; Mang, M.; Muehleck, C.; Rimke, H.; Sattelberger, P.; Herrmann, G.; Trautmann, N.; Kluge, H.J.; Otten, E.W.

    1988-01-01

    A resonant ionization mass spectrometer has been developed as an analytical tool for the detection of trace elements, especially of plutonium and other radionuclides. The sample, deposited on a rhenium filament, is evaporated by electrical heating and the atoms of the element under investigation are selectively ionized by laser light delivered from three dye lasers pumped by a copper vapour laser. The resulting photoions are detected in a time-of-flight spectrometer with a channelplate detector. For plutonium a mass resolution of M/ΔM=1500 was obtained and an overall detection efficiency of 4x10 -6 was determined for stepwise excitation and ionization via autoionizing states. With a laser light bandwidth of 3-5 GHz neighbouring isotopes could be suppressed by a factor of 20 due to isotope shifts in the excitation transitions. The isotope composition of synthetic samples was measured and good agreement was found with mass spectroscopic results. The influence of the hyperfine structure on the isotope ratios is discussed. (orig.)

  6. Small, but Determined: Technological Determinism in Nanoscience

    OpenAIRE

    Cyrus C.M. Mody

    2004-01-01

    Analysis of technological determinism by historians, sociologists, and philosophers has declined in recent years. Yet understanding this topic is necessary, particularly in examining the dynamics of emerging technologies and their associated research areas. This is especially true of nanotechnology, which, because of its roots in futurist traditions, employs unusual variants on classical determinist arguments. In particular, nanotechnology orients much more strongly to the past and future tha...

  7. Cave age determination

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    To determine the age of a cave we have to determine the age of elements which were created at the same moment when the cave was. Usually a cave is dug out by infiltration of acid waters. During this alteration process rocks free some aluminium and potassium ions. In Carlsbad and Lechuguilla caves, scientists have found alunite, this aluminium and potassium sulfate can be dated by using the carbon method of age determination. (A.C.)

  8. SIS - Status Determination

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Status Determination dataset within the Species Information System (SIS) contains information related to overfishing, overfished, and approaching overfished...

  9. Determination of cerium

    International Nuclear Information System (INIS)

    Stepin, V.V.; Kurbatova, V.I.; Fedorova, N.D.

    1980-01-01

    Techniques of cerium determination in steels and alloys are developed. Amperometric method of determination which is based on Ce(4) titration by a solution of double salt of sulfuric Fe(2) and ammonium when cerium amount exceeds 0.01% is suggested. Cerium is oxidated to tetravalent state by KMnO 4 . The elements interfering with the determination (Cr, Ni etc.) are separated by means of deposition. When cerium content exceeds 0.005% in steels and alloys the determination is carried out using photometric method with arsenazo 3 in hydrochloric medium (pH 1.8-2.3). Optimum concentration is 5-50 μg [ru

  10. Attitude Determination with Magnetometers and Accelerometers to Use in Satellite Simulator

    Directory of Open Access Journals (Sweden)

    Helio Koiti Kuga

    2013-01-01

    Full Text Available Attitude control of artificial satellites is dependent on information provided by its attitude determination process. This paper presents the implementation and tests of a fully self-contained algorithm for the attitude determination using magnetometers and accelerometers, for application on a satellite simulator based on frictionless air bearing tables. However, it is known that magnetometers and accelerometers need to be calibrated so as to allow that measurements are used to their ultimate accuracy. A calibration method is implemented which proves to be essential for improving attitude determination accuracy. For the stepwise real-time attitude determination, it was used the well-known QUEST algorithm which yields quick response with reduced computer resources. The algorithms are tested and qualified with actual data collected on the streets under controlled situations. For such street runaways, the experiment employs a solid-state magnetoresistive magnetometer and an IMU navigation block consisting of triads of accelerometers and gyros, with MEMS technology. A GPS receiver is used to record positional information. The collected measurements are processed through the developed algorithms, and comparisons are made for attitude determination using calibrated and noncalibrated data. The results show that the attitude accuracy reaches the requirements for real-time operation for satellite simulator platforms.

  11. Metabolic syndrome in Iranian patients with systemic lupus erythematosus and its determinants.

    Science.gov (United States)

    Fatemi, Alimohammad; Ghanbarian, Azadeh; Sayedbonakdar, Zahra; Kazemi, Mehdi; Smiley, Abbas

    2018-01-05

    The aim of this study was to determine the prevalence of metabolic syndrome (MetS) in Iranian patients with systemic lupus erythematosus (SLE) and its determinants. In a cross-sectional study, 98 patients with SLE and 95 controls were enrolled. Prevalence of MetS was determined based on American Heart Association and National Heart, Lung, and Blood Institute (AHA/NHLBI) and 2009 harmonizing criteria. In addition, demographic features and lupus characteristics such as disease duration, pharmacological treatment, laboratory data, SLE disease activity index (SLEDAI), and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage index (SDI) were recorded. The predictors of MetS were obtained by backward stepwise regression analysis. Using AHA/NHLBI, MetS was observed in 35 (35.7%) patients and 28 (29.8%) controls (P = 0.4). Using harmonizing criteria, MetS was observed in 37 (37.7%) patients and 33 (35.1%) controls (P = 0.7). There was no difference in frequency distribution of MetS components between the patients and the controls. In multivariate regression analysis, low C3, blood urea nitrogen (BUN), and body mass index were independent determinants of MetS in lupus patients. BUN, low C3, and body mass index were the major determinants of MetS in lupus patients.

  12. Analytical techniques for determination of framework oxygen isotope ratio of wairakite

    International Nuclear Information System (INIS)

    Noto, Masami; Kusakabe, Minoru; Uchida, Tetsuo.

    1990-01-01

    Dehydration techniques were developed for the analysis of isotopic ratios of framework oxygen of wairakite, one of calcium zeolites often encountered in geothermal systems. Channel water in wairakite were separated from aluminosilicate framework by dehydration in vacuum at 300 deg, 400 deg, 450 deg, 500 deg, 550 deg, 650 deg, 750 deg, 850 deg, and 950 degC, and by stepwise heating at temperatures from 300 deg to 700 degC. The oxygen isotopic analyses of the separated channel water and the residual aluminosilicate framework of wairakite indicated that dehydration at temperatures higher than 400 degC is accompanied by isotopic exchang between the framework oxygen and dehydrating water vapor. The isotopic exchange during the high temperature dehydration makes the δ 18 O of framework oxygen lower and that of channel water higher than those obtained by dehydration at 300 degC. These results are consistent with dehydration behavior of wairakite under vacuum that the maximum rate of dehydration of channel water is attained at about 400 degC. Consequently it is recommended to dehydrate wairakite at a temperature as low as possible in order to avoid the effect of the isotopic exchange. Time required to attain complete dehydration becomes longer with lowering the temperature of dehydration. To compromise these conflicting effects, the optimum conditions of dehydration have been found that most of the channel water is dehydrated at 300 degC for 24 hours, followed by stepwise heating for additional 17 hours up to 700 degC. We obtained a better than ± 0.1 reproducibility for the framework oxygen isotopic determinations with this technique. (author)

  13. Asteroids mass determination

    International Nuclear Information System (INIS)

    Hoffmann, M.

    1989-01-01

    Basic methods for asteroid mass determinations and their errors are discussed. New results and some current developments in the astrometric method are reviewed. New methods and techniques, such as electronic imaging, radar ranging and space probes are becoming important for asteroid mass determinations. Mass and density estimations on rotational properties and possible satelites are also discussed

  14. CATALYTIC KINETIC SPECTROPHOTOMETRIC DETERMINATION ...

    African Journals Online (AJOL)

    Preferred Customer

    acetylchlorophosphonazo(CPApA) by hydrogen peroxide in 0.10 M phosphoric acid. A novel catalytic kinetic-spectrophotometric method is proposed for the determination of copper based on this principle. Copper(II) can be determined spectrophotometrically ...

  15. Determinants of State Aid

    NARCIS (Netherlands)

    Buiren, K.; Brouwer, E.

    2010-01-01

    From economic theory we derive a set of hypotheses on the determination of state aid. Econometric analysis on EU state aid panel data is carried out to test whether the determinants we expect on the basis of theory, correspond to the occurrence of state aid in practice in the EU. We find that

  16. ATR confinement leakage determination

    International Nuclear Information System (INIS)

    Kuan, P.; Buescher, B.J.

    1998-01-01

    The air leakage rate from the Advanced Test Reactor (ATR) confinement is an important parameter in estimating hypothesized accidental releases of radiation to the environment. The leakage rate must be determined periodically to assure that the confinement has not degraded with time and such determination is one of the technical safety requirements of ATR operation. This paper reviews the methods of confinement leakage determination and presents an analysis of leakage determination under windy conditions, which can complicate the interpretation of the determined leakage rates. The paper also presents results of analyses of building air exchange under windy conditions. High wind can enhance air exchange and this could increase the release rates of radioisotopes following an accident

  17. Stepwise effects of the BCR sequential chemical extraction procedure on dissolution and metal release from common ferromagnesian clay minerals: A combined solution chemistry and X-ray powder diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, P.C. [Geology Department, Middlebury College, Middlebury, Vermont 05753 (United States)], E-mail: pryan@middlebury.edu; Hillier, S. [Macaulay Institute, Aberdeen, AB15 8QH UK (United Kingdom); Wall, A.J. [Department of Geosciences, Penn State University, University Park, Pennsylvania, 16802 (United States)

    2008-12-15

    Sequential extraction procedures (SEPs) are commonly used to determine speciation of trace metals in soils and sediments. However, the non-selectivity of reagents for targeted phases has remained a lingering concern. Furthermore, potentially reactive phases such as phyllosilicate clay minerals often contain trace metals in structural sites, and their reactivity has not been quantified. Accordingly, the objective of this study is to analyze the behavior of trace metal-bearing clay minerals exposed to the revised BCR 3-step plus aqua regia SEP. Mineral quantification based on stoichiometric analysis and quantitative powder X-ray diffraction (XRD) documents progressive dissolution of chlorite (CCa-2 ripidolite) and two varieties of smectite (SapCa-2 saponite and SWa-1 nontronite) during steps 1-3 of the BCR procedure. In total, 8 ({+-} 1) % of ripidolite, 19 ({+-} 1) % of saponite, and 19 ({+-} 3) % of nontronite (% mineral mass) dissolved during extractions assumed by many researchers to release trace metals from exchange sites, carbonates, hydroxides, sulfides and organic matter. For all three reference clays, release of Ni into solution is correlated with clay dissolution. Hydrolysis of relatively weak Mg-O bonds (362 kJ/mol) during all stages, reduction of Fe(III) during hydroxylamine hydrochloride extraction and oxidation of Fe(II) during hydrogen peroxide extraction are the main reasons for clay mineral dissolution. These findings underscore the need for precise mineral quantification when using SEPs to understand the origin/partitioning of trace metals with solid phases.

  18. Development of a systemwide predator control program: Stepwise implementation of a predation index, predator control fisheries, and evaluation plan in the Columbia River Basin. Volume 2 -- Evaluation: 1993 Annual report

    International Nuclear Information System (INIS)

    Willis, C.F.; Ward, D.L.

    1995-06-01

    An attempt was made to determine the extent to which northern squawfish predation on juvenile salmonids is a problem in the Columbia River Basin, and to evaluate how effectively fisheries can be used to control northern squawfish populations and reduce juvenile salmonid losses to predation. These studies were initiated as part of a basinwide program to control northern squawfish predation and reduce mortality of juvenile salmonids on their migration to the ocean. Modeling simulations based on work in the John Day Reservoir from 1982 through 1988 indicated that if northern squawfish larger than 250 mm fork length were exploited, at a rate of 10--20%, reductions in their numbers and restructuring of their populations could reduce their predation on juvenile salmonids by 50% or more. The authors evaluated the success of three test fisheries conducted in 1993--a sport-reward fishery, a dam-angling fishery, and a trap-net fishery, to achieve a 10--20% exploitation rate on northern squawfish. The authors also began evaluating the response of northern squawfish populations to sustained fisheries. In addition, the authors gathered information regarding the economic, social, and legal feasibility of sustaining each fishery, and report on the structure and function of the fish collection and distribution system

  19. Determinants of Actor Rationality

    DEFF Research Database (Denmark)

    Ellegaard, Chris

    Industrial companies must exercise influence on their suppliers (or supplier actors). Actor rationality is a central theme connected to this management task. In this article, relevant literature is studied with the purpose of shedding light on determinants of actor rationality. Two buyer-supplier...... relations are investigated in a multiple case study, leading to the proposal of various additional factors that determine and shape actor rationality. Moreover a conceptual model of rationality determinants in the buyer-supplier relation is proposed, a model that may help supply managers analyse...

  20. Depression is an independent determinant of life satisfaction early after stroke.

    Science.gov (United States)

    Oosterveer, Daniëlla M; Mishre, Radha Rambaran; van Oort, Andrea; Bodde, Karin; Aerden, Leo A M

    2017-03-06

    Life satisfaction is reduced in stroke patients. However, as a rule, rehabilitation goals are not aimed at life satisfaction, but at activities and participation. In order to optimize life satisfaction in stroke patients, rehabilitation should take into account the determinants of life satisfaction. The aim of this study was therefore to determine what factors are independent determinants of life satisfaction in a large group of patients early after stroke. Stroke-surviving patients were examined by a specialized nurse 6 weeks after discharge from hospital or rehabilitation setting. A standardized history and several screening lists, including the Lisat-9, were completed. Step-wise regression was used to identify independent determinants of life satisfaction. A total of 284 stroke-surviving patients were included in the study. Of these, 117 answered all of the Lisat-9 questions. Most patients (66.5%) rated their life as a whole as "satisfying" or "very satisfying". More depressive symptoms were independently associated with lower life satisfaction (p life early after a stroke. The score on the Hospital Anxiety and Depression Scale depression items is independently associated with life satisfaction. Physicians should therefore pay close attention to the mood of these patients.

  1. Calcium and magnesium determination

    International Nuclear Information System (INIS)

    Bhattacharya, S.K.

    1982-01-01

    The roles of calcium and magnesium in human health and disease have been extensively studied. Calcium and magnesium have been determined in biological specimens by atomic absorption spectroscopy using stiochiometric nitrous oxide-acetylene flame

  2. Commentary Sex determination

    Indian Academy of Sciences (India)

    PRAKASH KUMAR G

    2008-01-31

    ZW is reserved for female heterogamety.) The Radder et al study used lab incubation regimes that mimic temperature profiles of cool natural nests, so temperature probably determines sex at least occasionally in nature.

  3. Robust Growth Determinants

    OpenAIRE

    Doppelhofer, Gernot; Weeks, Melvyn

    2011-01-01

    This paper investigates the robustness of determinants of economic growth in the presence of model uncertainty, parameter heterogeneity and outliers. The robust model averaging approach introduced in the paper uses a flexible and parsi- monious mixture modeling that allows for fat-tailed errors compared to the normal benchmark case. Applying robust model averaging to growth determinants, the paper finds that eight out of eighteen variables found to be significantly related to economic growth ...

  4. Health determinants and podiatry.

    Science.gov (United States)

    Brodie, B S

    2001-09-01

    Public health and podiatry have a natural union both through historical development and a shared interest in prevention. Podiatry is considered in terms of health determinants such as income, social support, education and environment. The author considers that podiatry has a constructive role to play in the improvement of health and well-being in terms of the previously unrecognised relationship of the profession to the determinants of health and population health promotion.

  5. Determining postural stability

    Science.gov (United States)

    Lieberman, Erez (Inventor); Forth, Katharine E. (Inventor); Paloski, William H. (Inventor)

    2011-01-01

    A method for determining postural stability of a person can include acquiring a plurality of pressure data points over a period of time from at least one pressure sensor. The method can also include the step of identifying a postural state for each pressure data point to generate a plurality of postural states. The method can include the step of determining a postural state of the person at a point in time based on at least the plurality of postural states.

  6. Emergency operation determination system

    International Nuclear Information System (INIS)

    Miki, Tetsushi.

    1993-01-01

    The system of the present invention can determine an emergency operation coping with abnormal events occurring during nuclear plant operation without replying on an operator's judgement. That is, the system of the present invention comprises an intelligence base which divides and classifies the aims of the plant operation for the function, structure and operation manual and puts them into network. Degree of attainment for the extend of the status normality is determined on every aim of operation based on various kinds of measured data during plant operation. For a degree of attainment within a predetermined range, it is judged that an emergency operation is possible although this is in an abnormal state. Degree of emergency is determined by a fuzzy theory based on the degree of attainment, variation coefficient for the degree of attainment and the sensitivity to external disturbance as parameters. Priority for the degree of emergency on every operation aims is determined by comparison. Normality is successively checked for the determined operation aims. As a result, equipments as objects of abnormality suppressing operation are specified, and the operation amount of the equipments as objects are determined so that the measuring data are within a predetermined range. (I.S.)

  7. Determination method of radiostrontium

    International Nuclear Information System (INIS)

    1984-01-01

    This manual provides determination methods of strontium-90 and strontium-89 in the environment released from nuclear facilities, and it is a revised edition of the previous manual published in 1974. As for the preparation method of radiation counting sample, ion exchange method, oxalate separation method and solvent extraction method were adopted in addition to the method of fuming nitric acid separation adopted in the previous edition. Strontium-90 is determined by the separation and radioactivity determination of yttrium-90 in radioequilibrium with strontium-90. Strontium-89 is determined by subtraction of radioactivity of strontium-90 plus yttrium-90 from gross radioactivity of isolated strontium carbonate. Radioactivity determination should be carried out with a low-background 2 π-gas-flow counting system for the mounted sample on a filter having a chemical form of ferric hydroxide, yttrium oxalate or strontium carbonate. This manual describes sample preparation procedures as well as radioactivity counting procedures for environmental samples of precipitates as rain or snow, airborne dust, fresh water, sea water and soil, and also for ash sample made from biological or food samples such as grains, vegetables, tea leaves, pine needle, milk, marine organisms, and total diet, by employing a method of fuming nitric acid separation, ion exchange separation, oxalate precipitate separation or solvent extraction separation (only for an ash sample). Procedures for reagent chemicals preparation is also attached to this manual. (Takagi, S.)

  8. Statistical Attitude Determination

    Science.gov (United States)

    Markley, F. Landis

    2010-01-01

    All spacecraft require attitude determination at some level of accuracy. This can be a very coarse requirement of tens of degrees, in order to point solar arrays at the sun, or a very fine requirement in the milliarcsecond range, as required by Hubble Space Telescope. A toolbox of attitude determination methods, applicable across this wide range, has been developed over the years. There have been many advances in the thirty years since the publication of Reference, but the fundamentals remain the same. One significant change is that onboard attitude determination has largely superseded ground-based attitude determination, due to the greatly increased power of onboard computers. The availability of relatively inexpensive radiation-hardened microprocessors has led to the development of "smart" sensors, with autonomous star trackers being the first spacecraft application. Another new development is attitude determination using interferometry of radio signals from the Global Positioning System (GPS) constellation. This article reviews both the classic material and these newer developments at approximately the level of, with emphasis on. methods suitable for use onboard a spacecraft. We discuss both "single frame" methods that are based on measurements taken at a single point in time, and sequential methods that use information about spacecraft dynamics to combine the information from a time series of measurements.

  9. Sub-Pixel Accuracy Crack Width Determination on Concrete Beams in Load Tests by Triangle Mesh Geometry Analysis

    Science.gov (United States)

    Liebold, F.; Maas, H.-G.

    2018-05-01

    This paper deals with the determination of crack widths of concrete beams during load tests from monocular image sequences. The procedure starts in a reference image of the probe with suitable surface texture under zero load, where a large number of points is defined by an interest operator. Then a triangulated irregular network is established to connect the points. Image sequences are recorded during load tests with the load increasing continuously or stepwise, or at intermittently changing load. The vertices of the triangles are tracked through the consecutive images of the sequence with sub-pixel accuracy by least squares matching. All triangles are then analyzed for changes by principal strain calculation. For each triangle showing significant strain, a crack width is computed by a thorough geometric analysis of the relative movement of the vertices.

  10. Oxygen release technique as a method for the determination of "δ-pO2-T" diagrams for MIEC oxides.

    Science.gov (United States)

    Starkov, Ilya; Bychkov, Sergey; Matvienko, Alexander; Nemudry, Alexander

    2014-03-28

    A new approach to the determination of oxygen nonstoichiometry (δ) of MIEC oxides as a continuous function of pO2 at high temperatures was developed. The description of the model allowing one to distinguish the contribution of oxygen released from the samples to the partial pressure of oxygen at the outlet of the continuous-flow fixed-bed reactor after the stepwise change of the oxygen partial pressure of inlet gas from 0.2 to 10(-5) atm and to calculate the dependence of δ on pO2 is presented. The criterion for assessing the achievement of quasi equilibrium release of oxygen from the MIEC oxides is proposed. The adequacy of the method was confirmed by comparing the obtained and published data for well-studied SrCo0.8Fe0.2O3-δ and SrFeO3-δ MIEC oxides.

  11. Performance appraisal studies of laser-enhanced ionization in flames - the determination of nickel in petroleum products

    International Nuclear Information System (INIS)

    Turk, G.C.; Harvilla, G.J.; Webb, J.D.; Forster, A.R.; Shell Development Co., Houston, TX; The Standard Oil Co., Cleveland, OH)

    1984-01-01

    Laser-enhanced ionization (LEI) in flames is an ultrasensitive atomic flame spectrometric technique based on the efficient thermal ionization of atomic species which have been selectively excited by tunable laser radiation. The performance of LEI for real sample analysis is presently being evaluated. A successful determination of trace Ni concentrations in heavy oil flash distillate and Standard Reference Material Fuel Oil has been performed. One gram samples were diluted into 100 to 700 mL volumes of a xylene/n-butanol solvent mixture and aspirated directly into an air-acetylene flame. Stepwise laser excitation of Ni was performed using a Nd:YAG pumped dual-dye laser system. Accurate and reproducible results were obtained. 17 refs., 1 fig., 1 tab

  12. Airborne geoid determination

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.

    2000-01-01

    Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods...... relies on the development of airborne gravimetry, which in turn is dependent on developments in kinematic GPS. Routine accuracy of airborne gravimetry are now at the 2 mGal level, which may translate into 5-10 cm geoid accuracy on regional scales. The error behaviour of airborne gravimetry is well......-suited for geoid determination, with high-frequency survey and downward continuation noise being offset by the low-pass gravity to geoid filtering operation. In the paper the basic principles of airborne geoid determination are outlined, and examples of results of recent airborne gravity and geoid surveys...

  13. Determinants of marriage dissolution

    Science.gov (United States)

    Rahim, Mohd Amirul Rafiq Abu; Shafie, Siti Aishah Mohd; Hadi, Az'lina Abdul; Razali, Nornadiah Mohd; Azid @ Maarof, Nur Niswah Naslina

    2015-10-01

    Nowadays, the number of divorce cases among Muslim couples is very worrisome whereby the total cases reported in 2013 increased by half of the total cases reported in the previous year. The questions on the true key factors of dissolution of marriage continue to arise. Thus, the objective of this study is to reveal the factors that contribute to the dissolution of marriage. A total of 181 cases and ten potential determinants were included in this study. The potential determinants considered were age at marriage of husband and wife, educational level of husband and wife, employment status of husband and wife, income of husband and wife, the number of children and the presence at a counseling session. Logistic regression analysis was used to analyze the data. The findings revealed that four determinants, namely the income of husband and wife, number of children and the presence at a counselling session were significant in predicting the likelihood of divorce among Muslim couples.

  14. Spacecraft Attitude Determination

    DEFF Research Database (Denmark)

    Bak, Thomas

    This thesis describes the development of an attitude determination system for spacecraft based only on magnetic field measurements. The need for such system is motivated by the increased demands for inexpensive, lightweight solutions for small spacecraft. These spacecraft demands full attitude...... determination based on simple, reliable sensors. Meeting these objectives with a single vector magnetometer is difficult and requires temporal fusion of data in order to avoid local observability problems. In order to guaranteed globally nonsingular solutions, quaternions are generally the preferred attitude...... is a detailed study of the influence of approximations in the modeling of the system. The quantitative effects of errors in the process and noise statistics are discussed in detail. The third contribution is the introduction of these methods to the attitude determination on-board the Ørsted satellite...

  15. Fluorescence uranium determination

    International Nuclear Information System (INIS)

    Fernandez Cellini, R.; Crus Castillo, F. de la; Barrera Pinero, R.

    1960-01-01

    An equipment for analysis of uranium by fluorescence was developed in order to determine it at such a low concentration that it can not be determined by the most sensible analytical methods. this new fluorimeter was adapted to measure the fluorescence emitted by the phosphorus sodium fluoride-sodium carbonate-potasium carbonate-uranyl, being excited by ultraviolet light of 3,650 A the intensity of the light emitted was measure with a photomultiplicator RCA 5819 and the adequate electronic equipment. (Author) 19 refs

  16. Plasma beta HCG determination

    International Nuclear Information System (INIS)

    Amaral, L.B.D.; Pinto, J.C.M.; Linhares, E.; Linhares, Estevao

    1981-01-01

    There are three important indications for the early diagnosis of pregnancy through the determination of the beta sub-unit of chorionic gonadotrophin using radioimmunoassay: 1) some patient's or doctor's anxiety to discover the problem; 2) when it will be necessary to employ diagnostic or treatment procedures susceptible to affect the ovum; and 3) in the differential diagnosis of amenorrhoea, uterine hemorrhage and abdominal tumors. Other user's are the diagnosis of missed absortion, and the diagnosis and follow-up of chrorioncarcinoma. The AA. studied 200 determinations of plasma beta-HCG, considering the main difficulties occuring in the clinical use of this relevant laboratory tool in actual Obstetrics. (author) [pt

  17. Determining gold content

    International Nuclear Information System (INIS)

    Clayton, C.G.; Wormald, M.R.

    1981-01-01

    A method for determining the gold content of a material, comprises irradiating a body of the material with neutrons and determining the intensity of γ-rays having an energy of 279 keV arising from the reaction 179 Au(nn') 179 Au → 279 keV. The apparatus has means for conveying the materials past an assembly, which has a neutron source, which does not produce neutrons having sufficient energy to excite fast neutron reactions in non-auriferous constituents. (author)

  18. Are risks quantitatively determinable

    International Nuclear Information System (INIS)

    Buetzer, P.

    1985-01-01

    ''Chemical risks'' can only be determined with accurate figures in a few extraordinary cases. The difficulties lie, as has been shown by the example of the Flixborough catastrophe, mostly in the determination of the probabilities of occurrence. With a rough semiquantitative estimate of the potential hazards and the corresponding probabilities we can predict the risks with astonishing accuracy. Statistical data from incidents in the chemical industry are very useful, and they also show that ''chemical catastrophes'' are only to a very small extent initiated by uncontrolled chemical reactions. (orig.) [de

  19. Determinants of wood dust exposure in the Danish furniture industry.

    Science.gov (United States)

    Mikkelsen, Anders B; Schlunssen, Vivi; Sigsgaard, Torben; Schaumburg, Inger

    2002-11-01

    This paper investigates the relation between wood dust exposure in the furniture industry and occupational hygiene variables. During the winter 1997-98 54 factories were visited and 2362 personal, passive inhalable dust samples were obtained; the geometric mean was 0.95 mg/m(3) and the geometric standard deviation was 2.08. In a first measuring round 1685 dust concentrations were obtained. For some of the workers repeated measurements were carried out 1 (351) and 2 weeks (326) after the first measurement. Hygiene variables like job, exhaust ventilation, cleaning procedures, etc., were documented. A multivariate analysis based on mixed effects models was used with hygiene variables being fixed effects and worker, machine, department and factory being random effects. A modified stepwise strategy of model making was adopted taking into account the hierarchically structured variables and making possible the exclusion of non-influential random as well as fixed effects. For woodworking, the following determinants of exposure increase the dust concentration: manual and automatic sanding and use of compressed air with fully automatic and semi-automatic machines and for cleaning of work pieces. Decreased dust exposure resulted from the use of compressed air with manual machines, working at fully automatic or semi-automatic machines, functioning exhaust ventilation, work on the night shift, daily cleaning of rooms, cleaning of work pieces with a brush, vacuum cleaning of machines, supplementary fresh air intake and safety representative elected within the last 2 yr. For handling and assembling, increased exposure results from work at automatic machines and presence of wood dust on the workpieces. Work on the evening shift, supplementary fresh air intake, work in a chair factory and special cleaning staff produced decreased exposure to wood dust. The implications of the results for the prevention of wood dust exposure are discussed.

  20. Particle size determination

    International Nuclear Information System (INIS)

    Burr, K.J.

    1979-01-01

    A specification is given for an apparatus to provide a completely automatic testing cycle to determine the proportion of particles of less than a predetermined size in one of a number of fluid suspensions. Monitoring of the particle concentration during part of the process can be carried out by an x-ray source and detector. (U.K.)

  1. Determining TOC in Waters

    Science.gov (United States)

    Kehoe, Thomas J.

    1977-01-01

    The instrumental method for detecting total organic carbon (TOC) in water samples is detailed. The method's limitations are discussed and certain precautions that must be taken are emphasized. The subject of TOC versus COD and BOD is investigated and TOC is determined to be a valid indication of biological demand. (BT)

  2. Determining average yarding distance.

    Science.gov (United States)

    Roger H. Twito; Charles N. Mann

    1979-01-01

    Emphasis on environmental and esthetic quality in timber harvesting has brought about increased use of complex boundaries of cutting units and a consequent need for a rapid and accurate method of determining the average yarding distance and area of these units. These values, needed for evaluation of road and landing locations in planning timber harvests, are easily and...

  3. SHORT COMMUNICATION POTENTIOMETRIC DETERMINATION ...

    African Journals Online (AJOL)

    a

    SHORT COMMUNICATION. POTENTIOMETRIC DETERMINATION OF K+ IONS USING A K+-SELECTIVE. ELECTRODE WITH MACROCYCLIC LIQUID MEMBRANE. Cezar Spinu*, Marian Isvoranu, Maria Pleniceanu and Cristian Tigae. Faculty of Chemistry, University of Craiova, A.I. Cuza 13, Craiova, Romania. (Received ...

  4. Gender determination in populus

    Energy Technology Data Exchange (ETDEWEB)

    McLetchie, D.N. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Biological Sciences; Tuskan, G.A. [Oak Ridge National Lab., TN (United States)

    1994-12-31

    Gender, the expression of maleness or femaleness, in dioecious plants has been associated with changes in morphology, physiology, ecological position, and commercial importance of several species, including members of the Salicaceae family. Various mechanisms have been proposed to explain the expression of gender in Salicaceae, including sex chromosomes, simple Mendelian genes, quantitative genes, environment, and genotype-by-environment interactions. Published reports would favor a genetic basis for gender. The objective of this study was to identify molecular markers associated with gender in a segregating family of hybrid poplars. Bulked segregant analysis and chi-squared analysis were used to test for the occurrence of sex chromosomes, individual loci, and chromosome ratios (i.e., ploidy levels) as the mechanisms for gender determination. Examination of 2488 PCR based RAPD markers from 1219 primers revealed nine polymorphic bands between male and female bulked samples. However, linkage analysis indicated that none of these markers were significantly associated with gender. Chisquared results for difference in male-to-female ratios between diploid and triploid genotypes also revealed no significant differences. These findings suggest gender is not controlled via sex chromosomes, simple Mendelian loci or ratios of autosome to gender-determining loci. It is possible that gender is determined genetically by regions of the genome not sampled by the tested markers or by a complex of loci operating in an additive threshold manner or in an epistatic manner. It is also possible that gender is determined environmentally at an early zygote stage, canalizing gender expression.

  5. Application of three-dimensional reconstruction technology in establishment of atlas space model and sex determination

    International Nuclear Information System (INIS)

    Zhou Jianying; Tian Yong; He Qing; Li Youqiong; Han Qing; Cheng Kailiang

    2013-01-01

    Objective: To establish the method of using the atlas morphological indexes for sex determination in Jilin province and to evaluate its effect. Methods: The clinic neck CT images were used to reconstruct the 3D image of atlas. A total of 27 linear measurement on 8 aspects of the atlas were measured and the ratios were calculated. The 14 items were selected. Results: Of the total 27 linear measurements, 14 were sexually dimorphic (P<0.05), and the accuracies of sex determination of 27 indexes were 52.0% -89.3% . The highest accuracy was width of vertebral body (86.7% ). A function with variables predicting sex with 96.8% accuracy was derived by using stepwise method of discriminant function analysis: Y=1.308W - 0.409CDF - 0.469LTPSD - 0.849LUACD + 0.478RUACD + 0.332RDACD + 0.363ATH - 0.334PTH - 0.236PAL. Conclusion: The method of using atlas traits for sex determination in Jilin province is practicable. (authors)

  6. Investigation of the key determinants of Asian nurses’ quality of life

    Science.gov (United States)

    MAKABE, Sachiko; KOWITLAWAKUL, Yanika; NURUMAL, Mohd Said; TAKAGAI, Junko; WICHAIKHUM, Orn-Anong; WANGMO, Neyzang; YAP, Suk Foon; KUNAVIKTIKUL, Wipada; KOMATSU, Junko; SHIRAKAWA, Hideko; KIMURA, Yutaka; ASANUMA, Yoshihiro

    2018-01-01

    The study aimed to compare nurses’ quality of life and investigate key determinants among Asian countries with different economic status. A cross-sectional survey was conducted across five Asian countries (Japan, Singapore, Malaysia, Thailand, and Bhutan). Quality of life (WHOQOL-BREF), job stress (National Institute of Occupational Safety and Health questionnaire), and demographic data were assessed. Stepwise multivariate linear regression analysis was performed to identify the key determinants of quality of life. Participants were 3,829 nurses (response rate: 82%) with a mean age of 33 ± 10 yr and majority were women (92%). Regarding quality of life, Bhutan yielded the highest scores, followed by Malaysia, Thailand, Singapore, and Japan, and these results were statistically significant. The key determinants that were significantly related to quality of life were “stress coping ability,” “life satisfaction,” “Japan,” “social support,” “job stress,” and “Singapore” (adjusted R2=0.46). In conclusion, nurses’ quality of life differs across Asian countries and is not linked to the country’s economic development. To maintain a good quality of life for nurses, an international exchange program like international nursing conferences for work environment and staff coping strategies is recommended to broaden institution’ minds and share experiences and exchange views to be able to realize their own problems and discover global solutions to them. PMID:29491251

  7. Sex determination from the radius and ulna in a modern South African sample.

    Science.gov (United States)

    Barrier, I L O; L'Abbé, E N

    2008-07-18

    With a large number of unidentified skeletal remains found in South Africa, the development of population specific osteometric standards is imperative. Forensic anthropologists need to have access to a variety of techniques to establish accurate demographic profiles from complete, fragmentary and/or commingled remains. No research has been done on the forearm of African samples, even though these bones have been shown to exhibit sexual dimorphism. The purpose of this paper is to develop discriminant function formulae to determine sex from the radius and ulna in a South African population. The sample consisted of 200 male and 200 female skeletons from the Pretoria Bone (University of Pretoria) and Raymond A. Dart (Witwatersrand University) collections. Sixteen standard anthropometric measurements were taken from the radius (9) and ulna (7) and subjected to stepwise and direct discriminant function analysis. Distal breadth, minimum mid-shaft diameter and maximum head diameter were the best discriminators of sex for the radius, while minimum mid-shaft diameter and olecranon breadth were selected for the ulna. Classification accuracy for the forearm ranged from 76 to 86%. The radius and ulna can be considered moderate discriminators for determining sex in a South African group. However, it is advised that these formulae are used in conjunction with additional methods to determine sex.

  8. Isometric quadriceps strength determines sailing performance and neuromuscular fatigue during an upwind sailing emulation.

    Science.gov (United States)

    Bourgois, Jan G; Callewaert, Margot; Celie, Bert; De Clercq, Dirk; Boone, Jan

    2016-01-01

    This study investigates the physiological responses to upwind sailing on a laser emulation ergometer and analyses the components of the physical profile that determine the physiological responses related to sailing level. Ten male high-level laser sailors performed an upwind sailing test, incremental cycling test and quadriceps strength test. During the upwind sailing test, heart rate (HR), oxygen uptake, ventilation, respiratory exchange ratio, rating of perceived exertion (RPE) and lactate concentration were measured, combined with near-infrared spectroscopy (NIRS) and electromyography (EMG) registration of the M. Vastus lateralis. Repeated measures ANOVA showed for the cardio-respiratory, metabolic and muscles responses (mean power frequency [MPF], root mean square [RMS], deoxy[Hb+Mb]) during the upwind sailing test an initial significant increase followed by a stabilisation, despite a constant increase in RPE. Stepwise regression analysis showed that better sailing level was for 46.5% predicted by lower MPF decrease. Lower MPF decrease was for 57.8% predicted by a higher maximal isometric quadriceps strength. In conclusion, this study indicates that higher sailing level was mainly determined by a lower rate of neuromuscular fatigue during the upwind sailing test (as indicated by MPF decrease). Additionally, the level of neuromuscular fatigue was mainly determined by higher maximal isometric quadriceps strength stressing the importance of resistance training in the planning of training.

  9. Interfacial reaction using particle-immobilized reagents in a fluidized reactor. Determination of glycerol in biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Shishov, Andrey, E-mail: andrey.shishov.rus@gmail.com [Institute of Chemistry, Saint Petersburg State University, RU–198504 Saint Petersburg (Russian Federation); Zabrodin, Andrey; Moskvin, Leonid [Institute of Chemistry, Saint Petersburg State University, RU–198504 Saint Petersburg (Russian Federation); Andruch, Vasil [Department of Analytical Chemistry, University of P.J. Šafárik, SK-04154 Košice (Slovakia); Bulatov, Andrey [Institute of Chemistry, Saint Petersburg State University, RU–198504 Saint Petersburg (Russian Federation)

    2016-03-31

    A novel fluidized beads strategy for utilization of particle-immobilized reagents in flow analysis was developed in this study. The performance of the suggested strategy was demonstrated by the determination of glycerol in biodiesel. This analytical task was used as a proof-of-concept example. The method is based on on-line extraction of glycerol from biodiesel into aqueous stationary phase of extraction-chromatographic column, followed by elution and spectrophotometric determination in the form of copper glycerate formed in a fluidized reactor of stepwise injection system. The floating of cation exchange resin Dowex{sup ®} 50WX4, saturated with Cu(II) ions in liquid phase, was accomplished by air-bubbling. The linear range was from 100 to 1000 mg kg{sup −1}, and the limit of detection, calculated as 3s of a blank test (n = 5), was found to be 30 mg kg{sup −1}. The method was successfully applied to the analysis of biodiesel and biodiesel-blend (B 20) samples. - Highlights: • Novel fluidized beds strategy for utilization of particle-immobilized reagents. • First application of fluidized beds condition in SWIA. • Novel approach based on interfacial formation of copper glycerate. • Automated method for glycerol determination in biodiesel.

  10. Optimised method for the routine determination of Technetium-99 in environmental samples by liquid scintillation counting

    International Nuclear Information System (INIS)

    Wigley, F.; Warwick, P.E.; Croudace, I.W.; Caborn, J.; Sanchez, A.L.

    1999-01-01

    A method has been developed for the routine determination of 99 Tc in a range of environmental matrices using 99m Tc (t 1/2 =6.06 h) as an internal yield monitor. Samples are ignited stepwise to 550C and the 99 Tc is extracted from the ignited residue with 8 M nitric acid. Many contaminants are co-precipitated with Fe(OH) 3 and the Tc in the supernatant is pre-concentrated and further purified using anion exchange chromatography. Final separation of Tc from Ru is achieved by extraction of Tc into 5% tri-n-octylamine in xylene from 2 M sulphuric acid. The xylene fraction is mixed directly with a commercial liquid scintillant cocktail. The chemical yield is determined through the measurement of 99m Tc by gamma spectrometry and the 99 Tc activity is measured using liquid scintillation counting after a further two weeks to allow decay of the 99m Tc activity. Typical recoveries for this method are in the order 70-95%. The method has a detection limit of 1.7 Bq kg -1 based on a 2 h count time and a 10 g sample size. The chemical separation for 24 samples of sediment or marine biota can be completed by one analyst in a working week. A further week is required to allow the samples to decay before determination. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Investigation of the key determinants of Asian nurses' quality of life.

    Science.gov (United States)

    Makabe, Sachiko; Kowitlawakul, Yanika; Nurumal, Mohd Said; Takagai, Junko; Wichaikhum, Orn-Anong; Wangmo, Neyzang; Yap, Suk Foon; Kunaviktikul, Wipada; Komatsu, Junko; Shirakawa, Hideko; Kimura, Yutaka; Asanuma, Yoshihiro

    2018-06-01

    The study aimed to compare nurses' quality of life and investigate key determinants among Asian countries with different economic status. A cross-sectional survey was conducted across five Asian countries (Japan, Singapore, Malaysia, Thailand, and Bhutan). Quality of life (WHOQOL-BREF), job stress (National Institute of Occupational Safety and Health questionnaire), and demographic data were assessed. Stepwise multivariate linear regression analysis was performed to identify the key determinants of quality of life. Participants were 3,829 nurses (response rate: 82%) with a mean age of 33 ± 10 yr and majority were women (92%). Regarding quality of life, Bhutan yielded the highest scores, followed by Malaysia, Thailand, Singapore, and Japan, and these results were statistically significant. The key determinants that were significantly related to quality of life were "stress coping ability," "life satisfaction," "Japan," "social support," "job stress," and "Singapore" (adjusted R 2 =0.46). In conclusion, nurses' quality of life differs across Asian countries and is not linked to the country's economic development. To maintain a good quality of life for nurses, an international exchange program like international nursing conferences for work environment and staff coping strategies is recommended to broaden institution' minds and share experiences and exchange views to be able to realize their own problems and discover global solutions to them.

  12. Waste Determination Equivalency - 12172

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Rebecca D. [Savannah River Remediation (United States)

    2012-07-01

    The Savannah River Site (SRS) is a Department of Energy (DOE) facility encompassing approximately 800 square kilometers near Aiken, South Carolina which began operations in the 1950's with the mission to produce nuclear materials. The SRS contains fifty-one tanks (2 stabilized, 49 yet to be closed) distributed between two liquid radioactive waste storage facilities at SRS containing carbon steel underground tanks with storage capacities ranging from 2,800,000 to 4,900,000 liters. Treatment of the liquid waste from these tanks is essential both to closing older tanks and to maintaining space needed to treat the waste that is eventually vitrified or disposed of onsite. Section 3116 of the Ronald W. Reagan National Defense Authorization Act of Fiscal Year 2005 (NDAA) provides the Secretary of Energy, in consultation with the Nuclear Regulatory Commission (NRC), a methodology to determine that certain waste resulting from prior reprocessing of spent nuclear fuel are not high-level radioactive waste if it can be demonstrated that the waste meets the criteria set forth in Section 3116(a) of the NDAA. The Secretary of Energy, in consultation with the NRC, signed a determination in January 2006, pursuant to Section 3116(a) of the NDAA, for salt waste disposal at the SRS Saltstone Disposal Facility. This determination is based, in part, on the Basis for Section 3116 Determination for Salt Waste Disposal at the Savannah River Site and supporting references, a document that describes the planned methods of liquid waste treatment and the resulting waste streams. The document provides descriptions of the proposed methods for processing salt waste, dividing them into 'Interim Salt Processing' and later processing through the Salt Waste Processing Facility (SWPF). Interim Salt Processing is separated into Deliquification, Dissolution, and Adjustment (DDA) and Actinide Removal Process/Caustic Side Solvent Extraction Unit (ARP/MCU). The Waste Determination was signed

  13. A versatile synthesis of cyclic dipeptides using the stepwise construction of the piperazine-2,5-dione ring from simple precursors: synthetic sequence and the structure of a representative product, (3RS)-4-(2-allyl-3,5-dimethylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione.

    Science.gov (United States)

    Acosta Quintero, Lina M; Palma, Alirio; Cobo, Justo; Glidewell, Christopher

    2018-02-01

    A versatile synthesis of multiply substituted cyclic dipeptides has been designed, based on the stepwise construction of the piperazine-2,5-dione ring using molecular fragments from four different precursor molecules. Starting from substituted 2-allylanilines, reaction with methyl 2-bromo-2-phenylacetate yields the corresponding methyl 2-(2-allylanilino)-2-phenylacetates, which react with haloacetyl chlorides to give methyl 2-[N-(2-allylphenyl)-2-haloacetamido]-2-phenylacetates, which then undergo ring closure with benzylamine to yield the corresponding cyclic dipeptides of type 4-(2-allylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione. (3RS)-4-(2-Allyl-3,5-dimethylphenyl)-1-benzyl-3-phenylpiperazine-2,5-dione, C 28 H 28 N 2 O 2 , (IIId), crystallizes with Z' = 2 in the space group P2 1 /c; the allyl groups in the two independent molecules adopt different conformations and, in one of them, the allyl group is disordered over two sets of atomic sites having occupancies of 0.534 (4) and 0.466 (4). In both molecules, the piperazine-2,5-dione ring adopts a boat conformation, with the 3-phenyl ring in a quasi-axial site. The molecules of (IIId) are linked into a three-dimensional framework structure by a combination of three C-H...O hydrogen bonds and three C-H...π(arene) hydrogen bonds. Comparisons are made with some related structures.

  14. Determinants of translation ambiguity

    Science.gov (United States)

    Degani, Tamar; Prior, Anat; Eddington, Chelsea M.; Arêas da Luz Fontes, Ana B.; Tokowicz, Natasha

    2016-01-01

    Ambiguity in translation is highly prevalent, and has consequences for second-language learning and for bilingual lexical processing. To better understand this phenomenon, the current study compared the determinants of translation ambiguity across four sets of translation norms from English to Spanish, Dutch, German and Hebrew. The number of translations an English word received was correlated across these different languages, and was also correlated with the number of senses the word has in English, demonstrating that translation ambiguity is partially determined by within-language semantic ambiguity. For semantically-ambiguous English words, the probability of the different translations in Spanish and Hebrew was predicted by the meaning-dominance structure in English, beyond the influence of other lexical and semantic factors, for bilinguals translating from their L1, and translating from their L2. These findings are consistent with models postulating direct access to meaning from L2 words for moderately-proficient bilinguals. PMID:27882188

  15. Determinants for gallstone formation

    DEFF Research Database (Denmark)

    Shabanzadeh, Daniel Monsted; Sorensen, Lars Tue; Jørgensen, Torben

    2016-01-01

    . Gallstone incidence was assessed through repeated ultrasound examinations. Body mass index (BMI), blood pressure, self-rated health, lifestyle variables, blood lipids, and use of female sex hormones were measured at the baseline examination. Statistical analyses included logistic regression. Based...... re-examination were followed-up completely (mean 11.6 years, N = 2848). The overall cumulative incidence of gallstones was 0.60% per year. Independent positive determinants for incident gallstones were age, female sex, non-high density lipoprotein (non-HDL) cholesterol, and gallbladder polyps...... associations were found for blood pressure, smoking, alcohol consumption, HDL cholesterol, or triglycerides in meta-analyses. Conclusions: Age, female sex, BMI, non-HDL cholesterol, and polyps are independent determinants for gallstone formation. Incident gallstones and the metabolic syndrome share common risk...

  16. Determining Optimal Decision Version

    Directory of Open Access Journals (Sweden)

    Olga Ioana Amariei

    2014-06-01

    Full Text Available In this paper we start from the calculation of the product cost, applying the method of calculating the cost of hour- machine (THM, on each of the three cutting machines, namely: the cutting machine with plasma, the combined cutting machine (plasma and water jet and the cutting machine with a water jet. Following the calculation of cost and taking into account the precision of manufacturing of each machine, as well as the quality of the processed surface, the optimal decisional version needs to be determined regarding the product manufacturing. To determine the optimal decisional version, we resort firstly to calculating the optimal version on each criterion, and then overall using multiattribute decision methods.

  17. On Psychic Determinism.

    Science.gov (United States)

    Brown, Robin Gordon

    2017-06-01

    A confusion persists in the psychoanalytic literature regarding the concept of psychic determinism. Two authors are cited in whose works the concept is identified as foundational to psychoanalysis, in the one case as a "fundamental hypothesis" (Charles Brenner) and in the other as an "underlying presupposition" or assumption (Linda A.W. Brakel). Both claims are based on a conflation of the concept Freud had in mind with a philosophical doctrine going by the same name but meaning something quite different. The philosophical doctrine has no place in psychoanalysis at all, and Freud's concept does not play a foundational role there. In a second section a restricted concept of psychic determinism is critically examined. A third section deals with the impact of that restricted concept on clinical theory and contemporary controversies about clinical practice. Finally, some possible reasons for this confusion are suggested.

  18. Determination of nickel-63

    International Nuclear Information System (INIS)

    Poletiko, C.

    1988-01-01

    The research of activation products in the environment is often centered on cobalt-60 or other gamma emitters, since pure beta emitters require time consuming separations to be counted. However, some beta emitters must be checked because they have a build up in the environment, leading to potential hazards. Among these nuclides, there is nickel-63 which is a pure, soft beta emitter (67 keV) with a long half-life (100 years). A chemical separation, providing good results, was developed. Such a separation is based upon nickel carrier addition in the sample than DMG complex formation and isolation; after elimination of solvent. DMG complex is destroyed. Chemical yield is determined by flame atomic absorption measurement and nickel-63 counted by liquid scintillation. The described procedure allows the determination of low-level activities in different samples (soils, effluents, etc.). Detection limits are close to 0.1 Bq per sample

  19. Cyanides: decomposition and determination

    International Nuclear Information System (INIS)

    Gilath, I.; Cohen, L.

    1977-08-01

    Different cyanide destruction methods such as electrolysis (with and without the addition of salt), hypochlorite treatment and ion exchange detoxication were evaluated on a laboratory scale using model solutions. Parameters were determined for the optimal operation of the investigated processes. Analytical methods were adapted for concentrations and compositions of interest. An easy and rapid method of complex cyanide breakdown by ion exchange treatment was developed for analytical purposes. (author)

  20. Ion Mass Determination

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (100) is described for determining the mass of ions, the apparatus configured to hold a plasma (101 ) having a plasma potential. The apparatus (100) comprises an electrode (102) having a surface extending in a surface plane and an insulator (104) interfacing with the electrode (102......, and a processing unit (108) configured to interpret the detected impact locations in terms of the mass of the impacting ions....

  1. Satellite Photometric Error Determination

    Science.gov (United States)

    2015-10-18

    Satellite Photometric Error Determination Tamara E. Payne, Philip J. Castro, Stephen A. Gregory Applied Optimization 714 East Monument Ave, Suite...advocate the adoption of new techniques based on in-frame photometric calibrations enabled by newly available all-sky star catalogs that contain highly...filter systems will likely be supplanted by the Sloan based filter systems. The Johnson photometric system is a set of filters in the optical

  2. Stochastic split determinant algorithms

    International Nuclear Information System (INIS)

    Horvatha, Ivan

    2000-01-01

    I propose a large class of stochastic Markov processes associated with probability distributions analogous to that of lattice gauge theory with dynamical fermions. The construction incorporates the idea of approximate spectral split of the determinant through local loop action, and the idea of treating the infrared part of the split through explicit diagonalizations. I suggest that exact algorithms of practical relevance might be based on Markov processes so constructed

  3. Determination of vanadium

    International Nuclear Information System (INIS)

    Stepin, V.V.; Kurbatova, V.I.; Fedorova, N.D.

    1980-01-01

    Titrimetric and potentiometric methods of vanadium determination in ferrovanadium are developed. The essence of the titrimetric method using phenylanthranilic acid as indicator is in the following. Ferrovanadium weighed amount is dissolved in H 2 SO 4 , vanadium is oxidated by potassium permanganate to V(5) and is titrated by a solution of double salt of sulfuric Fe(2) and ammonium in the presence of indicator. Potentiometric titration is carried out using the same indicator [ru

  4. Uranium determination in water

    International Nuclear Information System (INIS)

    Prudenzo, E.J.; Puga, Maria J.; Cerchietti, Maria L.R.; Arguelles, Maria G.

    2005-01-01

    In our laboratory, a procedure has been assessed to determine uranium content of water in normal situations. The method proposed without sample pre-treatment, is simple and rapid. Uranium mass is measured by fluorimetry. For calculation of detection limit (Ld) and quantification level (Lq) we used blank samples and the results were analyzed for different statistical test. The calculation of total propagated uncertainty and sources contribution on real samples are presented. (author)

  5. Determination of vanadium

    International Nuclear Information System (INIS)

    Stepin, V.V.; Kurbatova, V.I.; Fedorova, N.D.

    1980-01-01

    Techniques of vanadium determination in steels and alloys are developed. Extraction-photometric method with N-phenyl-benzohydroxamic acid when V content is 0.005-0.5% is suggested. Molar coefficient of the complex quenching at lambdasub(max)=530 nm constitutes 5750. Optimum concentration is 15-150 μg per 25 ml of the solution, determination limit is 0.05 μg/ml. Chloroform is an extracting agent. A photometric method with acetohydrazide of anthranilic acid is suggested for the analysis of alloyed steels at V content 0.03-1%. The lower limit of V determination constitutes 0.64 μg/ml. Effect of Fe is removed using phosphoric acid. Amperometric method for steels and alloys at V content from 0.05 to 5% and for steels and alloys containing more than 3% W and Cr is also developed. The method is based on amperometric titration with solution of double sulfuric salt of Fe(2) and ammonium [ru

  6. Simulation study of stepwise relaxation in a spheromak plasma

    International Nuclear Information System (INIS)

    Horiuchi, Ritoku; Uchida, Masaya; Sato, Tetsuya.

    1991-10-01

    The energy relaxation process of a spheromak plasma in a flux conserver is investigated by means of a three-dimensional magnetohydrodynamic simulation. The resistive decay of an initial force-free profile brings the spheromak plasma to an m = 1/n = 2 ideal kink unstable region. It is found that the energy relaxation takes place in two steps; namely, the relaxation consists of two physically distinguished phases, and there exists an intermediate phase in between, during which the relaxation becomes inactive temporarily. The first relaxation corresponds to the transition from an axially symmetric force-free state to a helically symmetric one with an n = 2 crescent magnetic island structure via the helical kink instability. The n = 2 helical structure is nonlinearly sustained in the intermediate phase. The helical twisting of the flux tube creates a reconnection current in the vicinity of the geometrical axis. The second relaxation is triggered by the rapid growth of the n = 1 mode when the reconnection current exceeds a critical value. The helical twisting relaxes through magnetic reconnection toward an axially symmetric force-free state. It is also found that the poloidal flux reduces during the helical twisting in the first relaxation and the generation of the toroidal flux occurs through the magnetic reconnection process in the second relaxation. (author)

  7. Open Pit Optimisation and Design: A Stepwise Approach*

    African Journals Online (AJOL)

    Michael

    2015-12-02

    Dec 2, 2015 ... The erstwhile Nkroful Mining Limited (NML) had a concession with an approximate area of 47.84 km2 ... exploration drilling programme executed by NML ..... Strategic Planning ... the Nkroful Gold Mining Project, Western.

  8. Stepwise Advice Negotiation in Writing Center Peer Tutoring

    Science.gov (United States)

    Park, Innhwa

    2014-01-01

    While the delivery and reception of advice is a practice integral to a wide range of settings, little attention has been given to the detailed practices of advice resistance and how it leads to advice negotiation. Based on 7 hours of videotaped tutoring interactions among 6 tutors and 11 tutees, this conversation analytic study examines the…

  9. A Step-Wise Approach to Elicit Triangular Distributions

    Science.gov (United States)

    Greenberg, Marc W.

    2013-01-01

    Adapt/combine known methods to demonstrate an expert judgment elicitation process that: 1.Models expert's inputs as a triangular distribution, 2.Incorporates techniques to account for expert bias and 3.Is structured in a way to help justify expert's inputs. This paper will show one way of "extracting" expert opinion for estimating purposes. Nevertheless, as with most subjective methods, there are many ways to do this.

  10. Stepwise minimal debridement in Fournier's gangrene: a technical ...

    African Journals Online (AJOL)

    Fournier's gangrene, so called after the French physician who first described this condition in 1883, is a necrotizing fasciitis of the perineum and the genitalia. It is a fulminant gangrene of the genitalia. It is a polymicrobial infection caused by gram-positive, gram-negative anaerobic bacteria.1-4 The infection is said to spread ...

  11. Stepwise strategic environmental management in marine protected area

    Directory of Open Access Journals (Sweden)

    A. Padash

    2016-01-01

    Full Text Available In recent decades, necessity to protect environment has been a serious concern for all people and international communities. In appropriate development of human economic activities, subsistence dependence of the growing world population on nature decreases the natural diversity of ecosystems and habitats day by day and provides additional constraints for life and survival of wildlife. As a result, implementation of programs to protect species and ecosystems is of great importance. The current study was carried out to implement a comprehensive strategic environmental management plan in the Mond protected area in southern Iran. Accordingly, the protected area was zoned using multi criteria decision method. According to the numerical models, fifteen data layer were obtained on a scale of 1:50,000. The results revealed that 28.35% out of the entire study area belongs to nature conservation zone. In the following step, in order to offer the strategic planning using strength, weaknesses, opportunities and threats method, a total number of 154 questionnaires were prepared and filled by the relevant experts. For this purpose, after identifying the internal and external factors, they were weighted in the form of matrices as; internal factor evaluation and external factor evaluation. Analytical hierarchy process and expert choice software were applied to weight the factors. At the end, by considering the socioeconomic and environmental issues, the strategy of using protective strategies in line with international standards as well as a strong support of governmental national execution with a score of 6.05 was chosen as the final approach.

  12. Decomposition of Straw in Soil after Stepwise Repeated Additions

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst

    1979-01-01

    after the first repeated addition of labelled straw the soils were subjected to a number of “stress” treatments: addition of unlabelled glucose, air-drying, oven-drying, grinding and fumigation with vapour of chloroform, respectively. The CO2 that developed during the first 10 days after the treatments......, grinding the most. The effect of each treatment declined with an increasing number of successive additions of straw. The ratio between CO2 evolved after grinding and fumigation, respectively, revealed that grinding also exposed non-biomass material to accelerated decomposition. The effects of the stress...

  13. Stepwise biometric procedures for managing student attendance in ...

    African Journals Online (AJOL)

    Journal of Computer Science and Its Application. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 22, No 1 (2015) >. Log in or Register to get access to full text downloads.

  14. Stepwise "Dark Photoswitching" of Photochromic Dimers in a Junction

    DEFF Research Database (Denmark)

    Olsen, Stine Tetzschner; Hansen, Thorsten; Nielsen, Mogens Brøndsted

    2017-01-01

    -induced switching) has been termed dark photoswitching and was observed for the dihydroazulene–vinylheptafulvene couple in a junction. In this theoretical study, we expand this concept to dimeric structures containing two dihydroazulene units linked through meta- or para-phenylene bridges and anchored...

  15. Remodeling in the ischemic heart: the stepwise progression for heart

    Directory of Open Access Journals (Sweden)

    J.G. Mill

    2011-09-01

    Full Text Available Abstract Coronary artery disease is the leading cause of death in the developed world and in developing countries. Acute mortality from acute myocardial infarction (MI has decreased in the last decades. However, the incidence of heart failure (HF in patients with healed infarcted areas is increasing. Therefore, HF prevention is a major challenge to the health system in order to reduce healthcare costs and to provide a better quality of life. Animal models of ischemia and infarction have been essential in providing precise information regarding cardiac remodeling. Several of these changes are maladaptive, and they progressively lead to ventricular dilatation and predispose to the development of arrhythmias, HF and death. These events depend on cell death due to necrosis and apoptosis and on activation of the inflammatory response soon after MI. Systemic and local neurohumoral activation has also been associated with maladaptive cardiac remodeling, predisposing to HF. In this review, we provide a timely description of the cardiovascular alterations that occur after MI at the cellular, neurohumoral and electrical level and discuss the repercussions of these alterations on electrical, mechanical and structural dysfunction of the heart. We also identify several areas where insufficient knowledge limits the adoption of better strategies to prevent HF development in chronically infarcted individuals.

  16. Stepwise Reduction of Immobilized Mono layer Graphene Oxides

    DEFF Research Database (Denmark)

    Petersen, Søren; He, Yudong; Lang, Jiang

    2013-01-01

    to the pronounced aggregation that accompanies deoxygenation of GO in solution. Surface immobilization of monolayered graphene oxide (mGO) in Langmuir-Blodgett (LB) films was investigated as a method to circumvent this problem. Two types of LB films with different density of mGO flakes were prepared, i.e., diluted...

  17. Stepwise Bose-Einstein Condensation in a Spinor Gas.

    Science.gov (United States)

    Frapolli, C; Zibold, T; Invernizzi, A; Jiménez-García, K; Dalibard, J; Gerbier, F

    2017-08-04

    We observe multistep condensation of sodium atoms with spin F=1, where the different Zeeman components m_{F}=0,±1 condense sequentially as the temperature decreases. The precise sequence changes drastically depending on the magnetization m_{z} and on the quadratic Zeeman energy q (QZE) in an applied magnetic field. For large QZE, the overall structure of the phase diagram is the same as for an ideal spin-1 gas, although the precise locations of the phase boundaries are significantly shifted by interactions. For small QZE, antiferromagnetic interactions qualitatively change the phase diagram with respect to the ideal case, leading, for instance, to condensation in m_{F}=±1, a phenomenon that cannot occur for an ideal gas with q>0.

  18. STEPWISE SELECTION OF VARIABLES IN DEA USING CONTRIBUTION LOADS

    Directory of Open Access Journals (Sweden)

    Fernando Fernandez-Palacin

    Full Text Available ABSTRACT In this paper, we propose a new methodology for variable selection in Data Envelopment Analysis (DEA. The methodology is based on an internal measure which evaluates the contribution of each variable in the calculation of the efficiency scores of DMUs. In order to apply the proposed method, an algorithm, known as “ADEA”, was developed and implemented in R. Step by step, the algorithm maximizes the load of the variable (input or output which contribute least to the calculation of the efficiency scores, redistributing the weights of the variables without altering the efficiency scores of the DMUs. Once the weights have been redistributed, if the lower contribution does not reach a previously given critical value, a variable with minimum contribution will be removed from the model and, as a result, the DEA will be solved again. The algorithm will stop when all variables reach a given contribution load to the DEA or until no more variables can be removed. In this way and contrary to what is usual, the algorithm provides a clear stop rule. In both cases, the efficiencies obtained from the DEA will be considered suitable and rightly interpreted in terms of the remaining variables, indicating the load themselves; moreover, the algorithm will provide a sequence of alternative nested models - potential solutions - that could be evaluated according to external criterion. To illustrate the procedure, we have applied the methodology proposed to obtain a research ranking of Spanish public universities. In this case, at each step of the algorithm, the critical value is obtained based on a simulation study.

  19. System for step-wise accident protection of nuclear reactors

    International Nuclear Information System (INIS)

    Rubek, J.; Kuklik, B.; Bednarik, K.

    1991-01-01

    A system comprising electric switching circuits is proposed for the control of a WWER type reactor shutdown in case of turbine failure or another abnormal situation. The fastest reactor shutdown mode is only resorted to if the pressures in the primary and secondary circuits would otherwise increase above tolerable limits and safety valves would open. The temperature and pressure stress of the nuclear power plant components and fuel is reduced. In this manner, the losses emerging during turbine failures due to false alarms are minimized. The contacts of the system switch if the turbines are relieved to the power of the unit home consumption, if the first or second turbine fails by closing the quick-acting valves, if a signal for blocking the by-pass stations of the operated turbines appears, or if the electric supply of the control system and of the turbo-set protection fails. (M.D.). 1 fig

  20. Impact polarization and alignment creation parameters via stepwise excitation processes

    International Nuclear Information System (INIS)

    Csanak, G.; Cartwright, D.C.; Kazantsev, S.A.; Bray, I.

    1998-01-01

    W report here results from first order many body theory, distorted wave approximation, and converged close coupling calculations for polarization fractions and alignment creation parameters in the case of 2 1 S → n 1 P(n 3 - 5), 2 3 S → n 1 P(n = 2 - 5), 2 1 S → n 1 D(n = 3 - 5), 2 3 S → n 1 D(n = 3 - 5), 2 3 S → n 3 D(n = 3 - 5), and 2 1 S → n 3 D(n = 3 - 5) excitations in helium for electron impact energies from threshold to several hundred eV. (author)

  1. Stepwise strategic environmental management in marine protected area

    International Nuclear Information System (INIS)

    Padash, A.; Jozi, S. A.; Nabavi, S. M. B.; Dehzad, B.

    2016-01-01

    In recent decades, necessity to protect environment has been a serious concern for all people and international communities. In appropriate development of human economic activities, subsistence dependence of the growing world population on nature decreases the natural diversity of ecosystems and habitats day by day and provides additional constraints for life and survival of wildlife. As a result, implementation of programs to protect species and ecosystems is of great importance. The current study was carried out to implement a comprehensive strategic environmental management plan in the Mond protected area in southern Iran. Accordingly, the protected area was zoned using multi criteria decision method. According to the numerical models, fifteen data layer were obtained on a scale of 1:50,000. The results revealed that 28.35% out of the entire study area belongs to nature conservation zone. In the following step, in order to offer the strategic planning using strength, weaknesses, opportunities and threats method, a total number of 154 questionnaires were prepared and filled by the relevant experts. For this purpose, after identifying the internal and external factors, they were weighted in the form of matrices as; internal factor evaluation and external factor evaluation. Analytical hierarchy process and expert choice software were applied to weight the factors. At the end, by considering the socioeconomic and environmental issues, the strategy of using protective strategies in line with international standards as well as a strong support of governmental national execution with a score of 6.05 was chosen as the final approach.

  2. Improving precision in gel electrophoresis by stepwisely decreasing variance components.

    Science.gov (United States)

    Schröder, Simone; Brandmüller, Asita; Deng, Xi; Ahmed, Aftab; Wätzig, Hermann

    2009-10-15

    Many methods have been developed in order to increase selectivity and sensitivity in proteome research. However, gel electrophoresis (GE) which is one of the major techniques in this area, is still known for its often unsatisfactory precision. Percental relative standard deviations (RSD%) up to 60% have been reported. In this case the improvement of precision and sensitivity is absolutely essential, particularly for the quality control of biopharmaceuticals. Our work reflects the remarkable and completely irregular changes of the background signal from gel to gel. This irregularity was identified as one of the governing error sources. These background changes can be strongly reduced by using a signal detection in the near-infrared (NIR) range. This particular detection method provides the most sensitive approach for conventional CCB (Colloidal Coomassie Blue) stained gels, which is reflected in a total error of just 5% (RSD%). In order to further investigate variance components in GE, an experimental Plackett-Burman screening design was performed. The influence of seven potential factors on the precision was investigated using 10 proteins with different properties analyzed by NIR detection. The results emphasized the individuality of the proteins. Completely different factors were identified to be significant for each protein. However, out of seven investigated parameters, just four showed a significant effect on some proteins, namely the parameters of: destaining time, staining temperature, changes of detergent additives (SDS and LDS) in the sample buffer, and the age of the gels. As a result, precision can only be improved individually for each protein or protein classes. Further understanding of the unique properties of proteins should enable us to improve the precision in gel electrophoresis.

  3. Different Phenotypic Consequences of Simultaneous Versus Stepwise Apc Loss

    OpenAIRE

    Fischer, Jared M; Miller, Ashleigh J; Shibata, Darryl; Liskay, R Michael

    2011-01-01

    APC is considered a gatekeeper for colorectal cancer (CRC). Cells with heterozygous APC mutations have altered expression profiles suggesting that the first APC hit may help set the stage for subsequent transformation. Therefore, we measured transformation efficiency following what we have designated as “simultaneous” versus “stepwise” Apc loss. We combined a conditional Apc allele (ApcCKO ) with a Cre reporter gene and an out-of-frame Cre allele (Pms2cre ) that stochastically becomes functio...

  4. Identifying secondary series for stepwise common singular spectrum ...

    African Journals Online (AJOL)

    Abstract. Common singular spectrum analysis is a technique which can be used to forecast a pri- mary time series by using the information from a secondary series. Not all secondary series, however, provide useful information. A first contribution in this paper is to point out the properties which a secondary series should ...

  5. Stepwise Development Of Distributed Vertex Coloring Algorithms (Full Report)

    OpenAIRE

    Andriamiarina , Manamiary Bruno; Méry , Dominique

    2011-01-01

    Software-based systems have a strong impact in the daily life. For instance, systems like televisions, cell phones, credit cards are used for persons, while others systems, like networks, telecommunications, distributed and embedded devices, supercomputers, are used by organisations such as companies, governments, nations... Several countries, especially the advanced ones, rely on systems for the efficiency of domains like economy, health... Since they are needed in daily life, those systems ...

  6. Determination of zirconium

    International Nuclear Information System (INIS)

    Iha, C.; Sood, S.P.; Sato, I.M.

    1985-01-01

    The analysis of Zr and Hf by X-ray fluorescence was studied. The thin film technique for sample preparation by deposition of precipitate on the filter paper was used. The K sub(α) line of Zr and L sub(β) 1 line of Hf were considered for the analysis. The behaviour of fluorescence intensity ratio with the corresponding mass ratio was also studied. The direct determination of Hf in concentrations between 2 and 95% in samples without any separation was investigated. For Hf concentrations lower than 2%, a method for its enrichment was standardized. (Author) [pt

  7. LUMINESCENCE DETERMINATION OF ETODOLAC

    Directory of Open Access Journals (Sweden)

    A. V. Yegorova

    2015-02-01

    Full Text Available A highly sensitive, simple and rapid method for determination of non-steroidal anti- inflammatory drug – etodolac (Et in washings from surfaces of pharmaceutical equipment have been proposed. The intensity of native luminescence of water-n-propanol solutions of etodolac (λex= 274 nm; λlum= 350 nm was used as the analytical signal. The calibration graph is linear in the concentration range 0.014-2.3 μg/ml, the limit of detection is 0.5 ng/ml.

  8. Spectrophotometric Determination of Ezetimibe

    Directory of Open Access Journals (Sweden)

    P. Baby Sudha Lakshmi

    2010-01-01

    Full Text Available Two simple, sensitive, selective and accurate spectro-photometric methods (Method A and Method B for the determination of eztimibe in bulk drug and pharmaceutical formulations (tablets have been described. Method A and B are based on the redox/complex formation reaction of drug with 1,10-phenanthroline and hexacyano-ferrate(III in presence of ferric chloride to form coloured chromogens exhibiting λmax at 510 and 740 nm respectively. The results of analysis for the two methods have been validated statistically and by recovery studies. The results are compared with those obtained using UV spectrophotometric method in alcohol at 231.7 nm.

  9. Potentiometric determination of molybdenum

    International Nuclear Information System (INIS)

    Rusina, O.N.; Gorbatkova, B.Kh.

    1977-01-01

    Potentiometric titration by lead acetate is used to determine molybdenum in the form of molybdate ions. The behaviour of bimetallic electrode couples, i.e. tungsten-lead, platinum-lead, lead-carbon electrode, molybdenum-carbon electrode platinum-molibdenum has been investigated. The greatest jump of the potential in the finite point is observed for platinum-molybdenum electrode couple (150 mV/ml at pH 4.0-5.5). The limiting concentration of molybdenum in potentiometric titration by lead acetate is 2.8x10 -4 M. The measurements are accurate to within +-0.1%

  10. Determinants of capital structure.

    Science.gov (United States)

    McCue, M J; Ozcan, Y A

    1992-01-01

    This study analyzes the determinants of hospital capital structure in a new market setting that are created by the financial pressures of prospective payment and the intense price competition among hospitals. Using California data, the study found hospital system affiliation, bed size, growth rate in revenues, operating risk, and asset structure affected both short- and long-term debt borrowings. In addition, percentage of uncompensated care, profitability, and payer mix influenced short-term borrowings while market conditions and ownership affected long-term borrowings. Most significant of all is the finding that smaller hospitals tend to borrow more, possibly because they cannot generate funds internally.

  11. [Determining visual acuity with LH symbols and Landolt rings].

    Science.gov (United States)

    Gräf, M; Becker, R

    1999-08-01

    Lea (LH) symbols seem to be favourable for visual acuity assessment in childhood. The symbols of the LH test are well standardized and applicable to preschool children. We compared the visual acuity determined by LH single symbols (LH) and the acuity measured with the Landolt-C (LC). 138 cooperative subjects aged 7 to 91 years were examined. Their visual acuity was either normal or reduced due to various etiologies. Their refractive error was corrected. The monocular LH and LC were determined by a 3/4 criterion (study 1). In 19 healthy subjects aged 21 to 58 years, acuity was reduced stepwise by 5 different calibrated occlusives (study 2). A Lighthouse single symbol book (LH symbols) was used at a distance of 3 m. LC was determined at a distance of 5 m. The luminance of the test field was 180-200 cd/m2. The right eye of each patient and the amblyopic eye of the squinting patients was taken for statistical evaluation. The strabismic patients' interocular differences of LC and LH were compared. Within study 1, LC ranged from 0.02 to 2.0 and LH from 0.03 to 2.5. LH overestimated LC by 1.4 lines on an average (t-test p 1 line, 85.7% resp. 90% of the strabismic amblyopic patients with an interocular LC difference > 1 resp > 2 lines were detected. In study 2, LC ranged from 0.1 to 1.6, LH from 0.12 to 2.0. The mean difference LH-LC was 1.3 lines. The regression equation was lgLH = 0.91 lgLC + 0.08 (r = 0.95). LH symbols allow a reliable measurement of recognition acuity. Due to the design of the symbols, they are excellently suitable for application to preschool children. Age related normal values should be established. The systematic difference between the LC acuity and the LH acuity measured with the Lighthouse LH single symbol book by 1.4 lines has to be considered.

  12. Response to rocuronium and its determinants in patients with myasthenia gravis: A case-control study.

    Science.gov (United States)

    Fujimoto, Masafumi; Terasaki, Shuhei; Nishi, Masaaki; Yamamoto, Tatsuo

    2015-10-01

    Several previous studies using univariate analysis have suggested that the pre-anaesthetic train-of-four (TOF) ratio, concentration of anti-acetylcholine receptor (AChR) antibodies and the presence of preoperative generalised muscular involvement are determinants of an increased response to neuromuscular blocking agents (NMBAs) in patients with myasthenia gravis. However, the determinants of the response of patients with myasthenia gravis to rocuronium, which is expected to be used more frequently since the advent of sugammadex, have not been studied. To clarify whether previously suggested determinants of the response to other intermediate-acting NMBAs would also affect the response to rocuronium and to reveal the determinants of the increased response to rocuronium in individual patients with myasthenia gravis using multivariate analysis. Case control study. Kumamoto University Hospital, November 2010 to September 2013. Thirty-eight patients with myasthenia gravis having surgery using a total intravenous anaesthetic technique were investigated. After induction of general anaesthesia, the 95% effective dose (ED95) of rocuronium was calculated using cumulative dose-finding methods. Neuromuscular function was monitored by acceleromyographic assessment of TOF responses of the adductor pollicis muscle to ulnar nerve stimulation. Patients were then divided into the increased response (ED95 rocuronium injection (baseline TOF ratio), concentration of anti-AChR antibodies, Osserman classification and treatment for myasthenia gravis in the two groups were compared. Stepwise logistic regression identified baseline TOF ratio and age of onset of myasthenia gravis as determinants of the increased response to rocuronium in patients with myasthenia gravis [odds ratios (95% confidence interval) of 0.87 (0.77 to 0.98; P = 0.02) and 0.92 (0.86 to 0.99; P = 0.03), respectively]. Multivariate analysis identified baseline TOF ratio and age of disease onset as determinants of

  13. Determination of polynuclear hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lodge, Jr, J P

    1963-01-01

    At the present time, the method of choice for the determination of polynuclear hydrocarbons appears to be the following, (a) extraction of the benzene-soluble fraction from the gross collected particulate matter, (b) one pass through a chromatographic column of partially deactivated alumina, (c) spectral examination of the fractions and (d) the application of appropriate chemical tests as indicated by the previous step. Using this method, the presence of pyrene, fluoranthene, one of the benzofluorenes, chrysens, benz(a)anthracene, benzo(a)pyrene, benzo(e)pyrene, benzo(k)fluoranthene, anthanthrene, and coronene was demonstrated in the air of numerous American cities, and benzo(a)pyrene was measured at some 130 sites. Invaluable as such accurate determinations may be for research purposes, they are still too costly and time-consuming for routine survey purposes. While studies on the subject are by no means complete, they indicate the validity of piperonal chloride test as a general index of polycyclic hydrocarbons. This procedure is described in this paper. 7 references.

  14. Determinants of Discretionary Investments

    Directory of Open Access Journals (Sweden)

    K. S. Sujit

    2016-03-01

    Full Text Available Theoretical and empirical studies have focused on discretionary investments such as research and development (R&D and advertisement as value-creating activities. This empirical research article examines the determinants of the discretionary investment policy of food sector firms in India. The study aims to analyze the impact of financial policies and firm characteristics on the discretionary investment strategy of the food industry firms. The article uses the partial least squares structural equation modeling (PLS-SEM to understand the drivers of discretionary investment policy of food sector firms. The study finds that investment policy of firms is a major determinant of profitability of food sector firms. Higher investments in capital expenditures and working capital result in higher profitability. Management efficiency significantly influences firm profitability. The results suggest that riskier firms in food sector might focus on R&D investments as a strategy to generate more cash flows. Size of firm is negatively related to R&D intensity. Smaller firms in food sector tend to invest more in R&D. The study does not provide evidence to suggest that profitable firms invest more in R&D activities.

  15. Determination of radar MTF

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The ultimate goal of the Current Meter Array (CMA) is to be able to compare the current patterns detected with the array with radar images of the water surface. The internal wave current patterns modulate the waves on the water surface giving a detectable modulation of the radar cross-section (RCS). The function relating the RCS modulations to the current patterns is the Modulation Transfer Function (MTF). By comparing radar images directly with co-located CMA measurements the MTF can be determined. In this talk radar images and CMA measurements from a recent experiment at Loch Linnhe, Scotland, will be used to make the first direct determination of MTF for an X and S band radar at low grazing angles. The technical problems associated with comparing radar images to CMA data will be explained and the solution method discussed. The results suggest the both current and strain rate contribute equally to the radar modulation for X band. For S band, the strain rate contributes more than the current. The magnitude of the MTF and the RCS modulations are consistent with previous estimates when the wind is blowing perpendicular to the radar look direction.

  16. Determinants of global left ventricular peak diastolic filling rate during rest and exercise in normal volunteers

    International Nuclear Information System (INIS)

    Filiberti, A.W.; Bianco, J.A.; Baker, S.P.; Doherty; Nalivaika, L.A.; King, M.A.; Alpert, J.S.

    1984-01-01

    Early peak diastolic filling rate (PFR) of the left ventricle (LV) is said to be a sensitive index of LV dysfunction in patients with coronary disease, hypertension and hypertrophic cardiomyopathy. Radionuclide (RN0 multigated PFR was measured in 20 normal volunteers (13 males, 7 females, mean age 31 yrs., range 20-43) at rest and during supine bicycle exercise conducted to a symptomatic end-point. At rest, RN PFR was 3.4 +- SD 0.4 end-diastolic vols./sec (range 3.1 - 3.6). During exercise all normal volunteers had a progressive and numerically and statistically significant increase in PFR. Stepwise multiple linear regression (BMPD2R) was applied to the rest and exercise PFR data to develop a linear model describing the main determinants of the RN PFR. The potential independent variables which were included in the model were heart rate (HR), ejection fraction (EF), systolic arterial pressure, systolic ejection rate and exercise stage. Ranking of variables for prediction of RN PFR, and exclusion of less important variables, was done by F value criteria. The final multivariate equation was: LVPFR = -3.84437 + 0.03834 HR + 0.07537 LVEF. The model fit was highly significant (p<0.001), and accounted for 89 per cent of variability in the PFR. The authors conclude that the left ventricular peak filling rate is critically determined by heart rate and by ejection fraction at rest and during exercise

  17. The influence of hormonal status and socio-cultural determinants on postmenopausal sexual dysfunction.

    Directory of Open Access Journals (Sweden)

    Erdoğan Aslan

    2008-12-01

    Full Text Available Objective: To evaluate the hormonal and psycho-socio-cultural determinants that effect postmenopausal sexual dysfunction. Design: Case-control study. Setting: University hospital, Menopause clinics. Patients: 50 volunteers fit for inclusion criteria. Intervention: FSFI questionaire was applied to the participants after initial interview that preset questions evaluating psychosocio-cultural determinants were directed. Vaginal pH, total testosterone, and SHBG levels were measured in addition to routine menopause investigations. Results: FSFI scores were accordingly low in women who considered that they had a sexual dysfunction (50% and, in those who felt menopausal transition had a negative impact in their sexual relations (52% (p=0.00. While 6% of participants found sex after menopause as either shameful-unappropriate or unnecessary, other 17% stated that sex after menopause should continue as a duty of woman. 33% of the participants outlined that “motherhood” is the most important goal of their lives. Stepwise logistic regression analysis revealed a correlation between FSFI scores and FAI. Conclusion: FSD is prevalent in our country. Questioning the patient about the presence of sexual dysfunction may be sufficient to disclose the problem. FAI is a more reliable parameter in selecting candidates for androgen therapy.

  18. Determinants of abnormal blood pressure response to exercise in coronary artery disease

    International Nuclear Information System (INIS)

    Hakki, A.H.; Munley, B.M.; Hadjimiltiades, S.; Meissner, M.D.; Iskandrian, A.S.

    1986-01-01

    This study assessed the determinants of exercise-induced abnormal systolic blood pressure (BP) response in 127 patients with documented coronary artery disease (CAD) who underwent exercise thallium-201 scintigraphy. Three types of systolic BP response to exercise were identified: an increase by more than 20 mm Hg (group I, n = 74); an increase by 20 mm Hg or less (group II, n = 36); and a decrease of at least 10 mm Hg (group III, n = 17). The 3 groups were not significantly different in age, gender or medications. The number of segments with perfusion defects was significantly higher in groups II and III than group I (group III, 2.9 +/- 1.5; group II, 2.9 +/- 2.1; and group I, 1.8 +/- 1.4, p = 0.009). Prior myocardial infarction, abnormal left ventricular ejection fraction, and multivessel CAD were more common in group III than in groups I and II. Stepwise discriminant analysis of 15 relevant clinical, angiographic and exercise scintigraphic descriptors showed that the number of thallium perfusion defects, abnormal LV ejection fraction at rest and multivessel CAD to be important predictors of hypotensive BP response. Multivariate analysis, however, showed that the number of thallium perfusion defects was the only important predictor of the hypotensive response. Thus, it is the functional significance of CAD assessed by the extent of thallium perfusion abnormalities rather than the extent of CAD or left ventricular dysfunction at rest that determines the systolic BP response to exercise

  19. Sex determination using humeral dimensions in a sample from KwaZulu-Natal: an osteometric study.

    Science.gov (United States)

    Ogedengbe, Oluwatosin Olalekan; Ajayi, Sunday Adelaja; Komolafe, Omobola Aderibigbe; Zaw, Aung Khaing; Naidu, Edwin Coleridge Stephen; Okpara Azu, Onyemaechi

    2017-09-01

    The morphological characteristics of the humeral bone has been investigated in recent times with studies showing varying degrees of sexual dimorphism. Osteologists and forensic scientists have shown that sex determination methods based on skeletal measurements are population specific, and these population-specific variations are present in many body dimensions. The present study aims to establish sex identification using osteometric standards for the humerus in a contemporary KwaZulu-Natal population. A total of 11 parameters were measured in a sample of n=211 humeri (males, 113; females, 98) from the osteological collection in the Discipline of Clinical Anatomy, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa. The difference in means for nearly all variables were found to be significantly higher in males compared to females ( P <0.01) with the most effective single parameter for predicting sex being the vertical head diameter having an accuracy of 82.5%. Stepwise discriminant analysis increased the overall accuracy rate to 87.7% when all measurements were jointly applied. We conclude that the humerus is an important bone which can be reliably used for sex determination based on standard metric methods despite minor tribal or ancestral differences amongst an otherwise homogenous population.

  20. Computer-assisted sperm morphometry fluorescence-based analysis has potential to determine progeny sex

    Directory of Open Access Journals (Sweden)

    Pilar Santolaria

    2016-01-01

    Full Text Available This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences between X- and Y-chromosome-bearing spermatozoa (SX and SY, respectively. Spermatozoa from eight bulls were processed to assess simultaneously the sex chromosome by FISH and sperm morphometry by fluorescence-based CASA-Morph. SX cells were larger than SY cells on average (P < 0.001 although with important differences between bulls. A simultaneous evaluation of all the measured features by discriminant analysis revealed that nuclear area and average fluorescence intensity were the variables selected by stepwise discriminant function analysis as the best discriminators between SX and SY. In the second experiment, the sperm nuclear morphometric results from CASA-Morph in nonsexed (mixed SX and SY and sexed (SX semen samples from four bulls were compared. FISH allowed a successful classification of spermatozoa according to their sex chromosome content. X-sexed spermatozoa displayed a larger size and fluorescence intensity than nonsexed spermatozoa (P < 0.05. We conclude that the CASA-Morph fluorescence-based method has the potential to find differences between X- and Y-chromosome-bearing spermatozoa in bovine species although more studies are needed to increase the precision of sex determination by this technique.